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1
Filipiak, Wojciech, Matthias Wenzel, Clemens Ager, Chris A. Mayhew, Tomasz Bogiel, Robert Włodarski e Markus Nagl. "Molecular Analysis of Volatile Metabolites Synthesized by Candida albicans and Staphylococcus aureus in In Vitro Cultures and Bronchoalveolar Lavage Specimens Reflecting Single- or Duo-Factor Pneumonia". Biomolecules 14, n. 7 (2 luglio 2024): 788. http://dx.doi.org/10.3390/biom14070788.
Testo completoAbstract (sommario):
Current microbiological methods for pneumonia diagnosis require invasive specimen collection and time-consuming analytical procedures. There is a need for less invasive and faster methods to detect lower respiratory tract infections. The analysis of volatile metabolites excreted by pathogenic microorganisms provides the basis for developing such a method. Given the synergistic role of Candida albicans in increasing the virulence of pathogenic bacteria causing pneumonia and the cross-kingdom metabolic interactions between microorganisms, we compare the emission of volatiles from Candida albicans yeasts and the bacteria Staphylococcus aureus using single and mixed co-cultures and apply that knowledge to human in vivo investigations. Gas chromatography–mass spectrometry (GC-MS) analysis resulted in the identification of sixty-eight volatiles that were found to have significantly different levels in cultures compared to reference medium samples. Certain volatiles were found in co-cultures that mainly originated from C. albicans metabolism (e.g., isobutyl acetate), whereas other volatiles primarily came from S. aureus (e.g., ethyl 2-methylbutyrate). Isopentyl valerate reflects synergic interactions of both microbes, as its level in co-cultures was found to be approximately three times higher than the sum of its amounts in monocultures. Hydrophilic–lipophilic-balanced (HLB) coated meshes for thin-film microextraction (TFME) were used to preconcentrate volatiles directly from bronchoalveolar lavage (BAL) specimens collected from patients suffering from ventilation-associated pneumonia (VAP), which was caused explicitly by C. albicans and S. aureus. GC-MS analyses confirmed the existence of in vitro-elucidated microbial VOCs in human specimens. Significant differences in BAL-extracted amounts respective to the pathogen-causing pneumonia were found. The model in vitro experiments provided evidence that cross-kingdom interactions between pathogenic microorganisms affect the synthesis of volatile compounds. The TFME meshes coated with HLB particles proved to be suitable for extracting VOCs from human material, enabling the translation of in vitro experiments on the microbial volatilome to the in vivo situation involving infected patients. This indicates the direction that should be taken for further clinical studies on VAP diagnosis based on volatile analysis.
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Magaña, Lizeth O., Parvathy Prem, Ariel N. Deutsch, Anna C. Martin, Heather M. Meyer, Caleb I. Fassett, Michael K. Barker et al. "Surface Roughness at the Moon’s South Pole: The Influence of Condensed Volatiles on Surface Roughness at the Moon’s South Pole". Planetary Science Journal 5, n. 2 (1 febbraio 2024): 30. http://dx.doi.org/10.3847/psj/ad18da.
Testo completoAbstract (sommario):
Abstract Condensed volatiles within lunar permanently shadowed regions are of high scientific and resource utilization importance. Volatiles remain elusive and difficult to observe directly, due to low direct solar illumination. In this work, we investigate correlations between, as well as possible effects of, condensed volatiles and surface roughness. We analyze topographic roughness at 50 m and 30–120 m baselines of the lunar south pole (poleward of 85° S). We focus on six south polar craters of interest and their directly surrounding non-cold-trap areas: Faustini, Shoemaker, Haworth, Cabeus, Nobile, and an unnamed region. We further analyze six analogous equatorial craters to investigate the non-ice smoothing contributions: Morozov F, Rosenberger C, Van Maanen, Fraunhofer E, Brisbane, and Asclepi. Lastly, we compare a sunlit and a permanently shaded portion of the Amundsen crater floor. Utilizing data from the Lunar Reconnaissance Orbiter’s Lunar Orbiter Laser Altimeter (LOLA), Lyman Alpha Mapping Project (LAMP), Lunar Reconnaissance Orbiter Camera, and Diviner Lunar Radiometer Experiment, we find subdued roughness within cold traps but determine that roughness is not a unique identifier of condensed volatiles. However, a correlation between LOLA roughness, LAMP normalized Off-band/On-band albedo, temperature, and water-ice stability suggests possible terrain softening due to condensed volatiles, although we cannot rule out dust ponding and/or fairy castle structure contributions. We conclude that LAMP volatile signatures at the topmost ∼100 nm may be indicative of volatile deposits at depths beyond the LAMP sensing capabilities.
3
Revadi, Santosh V., Vito Antonio Giannuzzi, Ramesh R. Vetukuri, William B. Walker e Paul G. Becher. "Larval response to frass and guaiacol: detection of an attractant produced by bacteria from Spodoptera littoralis frass". Journal of Pest Science 94, n. 4 (5 marzo 2021): 1105–18. http://dx.doi.org/10.1007/s10340-021-01352-9.
Testo completoAbstract (sommario):
AbstractLarval frass in herbivorous lepidopterans is mainly composed of plant-derived material and microbes from the gut. Despite the fact that frass from conspecific larvae repels female moths in Spodoptera littoralis from oviposition, the role of frass volatiles on larval foraging behavior is largely unknown. Here, we show that larvae of S. littoralis walk upwind to larval frass volatiles in a wind tunnel assay. We identified the frass volatile guaiacol (2-methoxyphenol) as key ligand for the S. littoralis odorant receptor (OR) SlitOr59 which we expressed heterologously. We isolated guaiacol-producing bacteria identified as Serratia marcescens from frass of larvae that were fed on cotton, and Enterobacter cloacae, E. ludwigii and Klebsiella sp. from frass derived from cabbage-fed larvae. In addition to guaiacol, we also identified volatiles acetoin, 3-methyl-1-butanol and dimethyl disulfide, in large proportions in headspace collections from the bacteria. A Y-tube olfactometer assay showed that fourth instar S. littoralis larvae are attracted to guaiacol. Moreover, cotton leaves treated with the insecticide Spinosad and guaiacol were highly attractive to the larvae. Our results provide a basis for management of the pest by directly targeting larvae, based on an attract-and-kill strategy. Further studies are needed to test the application of guaiacol for semiochemical-based pest management of Spodoptera pest species.
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Osei-Owusu, Jonathan, William K. Heve, Owusu Fordjour Aidoo, Maxwell Jnr Opoku, Joseph Apau, Kodwo Ninsin Dadzie, Bright Yaw Vigbedor et al. "Repellency Potential, Chemical Constituents of Ocimum Plant Essential Oils, and Their Headspace Volatiles against Anopheles gambiae s. s., Malaria Vector". Journal of Chemistry 2023 (14 luglio 2023): 1–12. http://dx.doi.org/10.1155/2023/3848998.
Testo completoAbstract (sommario):
African malaria mosquitoes (Anopheles gambiae sensu stricto) transmit a malaria parasite (Plasmodium falciparum) to humans. The current control strategies for the vector have mainly focussed on synthetic products, which negatively impact the environment and human health. Given the potential use of environmentally friendly plant-derived volatiles as a control, this work aims to examine and compare the repellency potential of essential oils and headspace volatiles from Ocimum gratissimum, Ocimum tenuiflorum, and Ocimum basilicum and their chemical compositions. The repellency potential and chemical composition of the plants were achieved by using the protected arm-in-cage method and gas chromatography-mass spectrometry (GC-MS) analysis. Among the three Ocimum species, both the essential oils and the headspace volatiles from O. tenuiflorum achieved the longest repellency time lengths of 90–120 minutes. One hundred and one (101) chemical constituents were identified in the headspace volatiles of the three Ocimum spp. Nonetheless, (−)-camphor, (E)-γ-bisabolene, terpinolene, β-chamigrene, cubedol, (E)-farnesol, germacrene D-4-ol, viridiflorol, γ-eudesmol, tetracyclo [6.3.2.0 (2,5).0(1,8)] tridecan-9-ol, 4,4-dimethyl, α-eudesmol, isolongifolol, and endo-borneol were unique only to O. tenuiflorum headspace volatiles. Either essential oils or headspace volatiles from O. tenuiflorum could offer longer protection time length to humans against An. gambiae. Though field studies are needed to assess the complementarity between the chemical constituents in the headspace volatiles of O. tenuiflorum, our observations provide a foundation for developing effective repellents against An. gambiae.
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Mülner, Pascal, Alessandro Bergna, Philipp Wagner, Dženana Sarajlić, Barbara Gstöttenmayr, Kristin Dietel, Rita Grosch, Tomislav Cernava e Gabriele Berg. "Microbiota Associated with Sclerotia of Soilborne Fungal Pathogens – A Novel Source of Biocontrol Agents Producing Bioactive Volatiles". Phytobiomes Journal 3, n. 2 (gennaio 2019): 125–36. http://dx.doi.org/10.1094/pbiomes-11-18-0051-r.
Testo completoAbstract (sommario):
Soilborne plant pathogens are an increasing problem in modern agriculture, and their ability to survive long periods in soil as persistent sclerotia makes control and treatment particularly challenging. To develop new control strategies, we explored bacteria associated with sclerotia of Sclerotinia sclerotiorum and Rhizoctonia solani, two soilborne fungi causing high yield losses. We combined different methodological approaches to get insights into the indigenous microbiota of sclerotia, to compare it to bacterial communities of the surrounding environment, and to identify novel biocontrol agents and antifungal volatiles. Analysis of 16S rRNA gene fragment amplicons revealed significant compositional differences in the bacterial microbiomes of Rhizoctonia sclerotia, the unaffected tuber surface and surrounding soil. Moreover, distinctive bacterial lineages were associated with specific sample types. Flavobacteriaceae and Caulobacteraceae were primarily found in unaffected areas, while Phyllobacteriaceae and Bradyrhizobiaceae were associated with sclerotia of R. solani. In parallel, we studied a strain collection isolated from sclerotia of the pathogens for emission of bioactive volatile compounds. Isolates of Bacillus, Pseudomonas, and Buttiauxella exhibited high antagonistic activity toward both soilborne pathogens and were shown to produce novel, not yet described volatiles. Differential imaging showed that volatiles emitted by the antagonists altered the melanized sclerotia surface of S. sclerotiorum. Interestingly, combinations of bacterial antagonists increased inhibition of mycelial growth up to 60% when compared with single isolates. Our study showed that fungal survival structures are associated with a specific microbiome, which is also a reservoir for new biocontrol agents.
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Marčetić, Mirjana, Dragana Božić, Marina Milenković, Branislava Lakušić e Nada Kovačević. "Chemical Composition and Antimicrobial Activity of Essential Oil of Different Parts of Seseli rigidum". Natural Product Communications 7, n. 8 (agosto 2012): 1934578X1200700. http://dx.doi.org/10.1177/1934578x1200700832.
Testo completoAbstract (sommario):
The chemical composition and antimicrobial activity of the essential oil of the Balkan endemic species Seseli rigidum Waldst. & Kit. (Apiaceae) was investigated. The monoterpene α-pinene was predominant in the volatile oil from aerial parts (57.4%) and fruit (23.3%). In the essential oil of the aerial parts limonene (6.7%), camphene (5.8%) and sabinene (5.5%) were also present in high amounts, and in the fruit oil, β-phellandrene (17.4%) and sabinene (12.9%). On the contrary, the root essential oil was composed almost entirely of the polyacetylene falcarinol (88.8%). The antimicrobial activity of the root essential oil was significant against Staphylococcus aureus, S. epidermidis, Micrococcus luteus and Enterococcus faecalis (MICs 6.25–25.00 μg/mL). Volatile constituents from the root strongly inhibited the growth of methicillin-resistant strains of S. aureus (MICs 6.25–50.00 μg/mL). Anti-staphylococcal activity can be attributed to the main volatile constituent of S. rigidum root, falcarinol.
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Lyons, Sarah M., Sydney C. Morgan, Stephanie McCann, Samantha Sanderson, Brianne L. Newman, Tommaso Liccioli Watson, Vladimir Jiranek, Daniel M. Durall e Wesley F. Zandberg. "Unique volatile chemical profiles produced by indigenous and commercial strains of Saccharomyces uvarum and Saccharomyces cerevisiae during laboratory-scale Chardonnay fermentations". OENO One 55, n. 3 (27 luglio 2021): 101–22. http://dx.doi.org/10.20870/oeno-one.2021.55.3.4551.
Testo completoAbstract (sommario):
Each wine growing region hosts unique communities of indigenous yeast species, which may enter fermentation and contribute to the final flavour profile of wines. One of these species, Saccharomyces uvarum, is typically described as a cryotolerant yeast that produces relatively high levels of glycerol and rose-scented volatile compounds as compared with Saccharomyces cerevisiae, the main yeast in winemaking. Comparisons of fermentative and chemical properties between S. uvarum and S. cerevisiae at the species level are relatively common; however, a paucity of information has been collected on the potential variability present among S. uvarum strains. The objective of this study was to compare the fermentation kinetics and production of volatile compounds between indigenous and commercial Saccharomyces strains at different temperatures. We compared laboratory-scale fermentation of Chardonnay juice at 15 °C and 25 °C for 11 Saccharomyces yeast strains (six indigenous S. uvarum, one commercial S. uvarum, one indigenous S. cerevisiae and three commercial S. cerevisiae). Fermentation kinetics and the production of volatile compounds known to affect the organoleptic properties of wine were determined. The indigenous S. uvarum strains showed comparable kinetics to commercially sourced strains at both temperatures. Volatile compound production among the strains was more variable at 15 °C and resulted in unique chemical profiles at 15 °C as compared with 25 °C. Indigenous S. uvarum strains produced relatively high levels of 2-phenylethyl acetate and 2-phenylethanol, whereas these compounds were found at much lower levels in fermentations conducted by commercial strains of both S. cerevisiae and S. uvarum. Production of glycerol by indigenous S. uvarum strains did not differ from commercial strains in this study. Our findings demonstrate that indigenous strains of S. uvarum show functional variation among themselves. However, when compared with commercial S. cerevisiae and S. uvarum strains, they have comparable fermentation kinetics but unique volatile compound profiles, especially at low fermentation temperatures.
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Imade, Rose O., e Buniyamin A. Ayinde. "GC-MS analysis and invitro cytotoxic activity of Ocimum basilicum (Lamiaceae) volatile oil and active fraction composed majorly of estragole". Journal of Pharmacy & Bioresources 19, n. 3 (22 dicembre 2022): 143–52. http://dx.doi.org/10.4314/jpb.v19i3.3.
Testo completoAbstract (sommario):
Ocimum basilicum leaves contain some bioactive compounds and this study was designed to evaluate the cytotoxic efficacy of its volatile oil and fractions. Preliminary screening of the oil obtained by hydrodistillation was carried out using bench-top assay methods employing tadpoles of Raniceps ranninus (10-40 μg/mL), nauplii of Artemia salina (10-1000 μg/mL) and radicles of Sorghum bicolor seeds (1-30 mg/mL). Application of column chromatography and preparative TLC on the oil resulted in fractions that were tested alongside the oil on breast (AU 565) and cervical (HeLa) cancer cell lines at 50 μg/mL. GCMS analysis was carried out on the oil and the most active fraction. A concentration dependent activity was observed in the preliminary screening with the bench-top assays. The active fraction produced greater growth inhibition of the radicle of S. bicolor seeds than the oil. Inhibitions of -1.02 and +23.02 % were realized against AU 565 and HeLa cell lines respectively with the oil, and these were increased to +33.19 and +89.3 % inhibitions respectively with the active fraction. GCMS results revealed the presence of estragole (88.61 %) as being most abundant in the fraction. This result shows the cytotoxic potential of O. basilicum volatile oil, which was increased in its estragole-containing fraction.
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BONNARME, PASCAL, CARMEN LAPADATESCU, MIREILLE YVON e HENRY-ERIC SPINNLER. "L-methionine degradation potentialities of cheese-ripening microorganisms". Journal of Dairy Research 68, n. 4 (novembre 2001): 663–74. http://dx.doi.org/10.1017/s002202990100509x.
Testo completoAbstract (sommario):
Volatile sulphur compounds are major flavouring compounds in many traditional fermented foods including cheeses. These compounds are products of the catabolism of L-methionine by cheese-ripening microorganisms. The diversity of L-methionine degradation by such microorganisms, however, remains to be characterized. The objective of this work was to compare the capacities to produce volatile sulphur compounds by five yeasts, Geotrichum candidum, Yarrowia lipolytica, Kluyveromyces lactis, Debaryomyces hansenii, Saccharomyces cerevisiae and five bacteria, Brevibacterium linens, Corynebacterium glutamicum, Arthrobacter sp., Micrococcus luteus and Staphylococcus equorum of technological interest for cheese-ripening. The ability of whole cells of these microorganisms to generate volatile sulphur compounds from L-methionine was compared. The microorganisms produced a wide spectrum of sulphur compounds including methanethiol, dimethylsulfide, dimethyldisulfide, dimethyltrisulfide and also S-methylthioesters, which varied in amount and type according to strain. Most of the yeasts produced methanethiol, dimethylsulfide, dimethyldisulfide and dimethyltrisulfide but did not produce S-methylthioesters, apart from G. candidum that produced S-methyl thioacetate. Bacteria, especially Arth. sp. and Brevi. linens, produced the highest amounts and the greatest variety of volatile sulphur compounds including methanethiol, sulfides and S-methylthioesters, e.g. S-methyl thioacetate, S-methyl thiobutyrate, S-methyl thiopropionate and S-methyl thioisovalerate. Cell-free extracts of all the yeasts and bacteria were examined for the activity of enzymes possibly involved in L-methionine catabolism, i.e. L-methionine demethiolase, L-methionine aminotransferase and L-methionine deaminase. They all possessed L-methionine demethiolase activity, while some (K. lactis, Deb. hansenii, Arth. sp., Staph. equorum) were deficient in L-methionine aminotransferase, and none produced L-methionine deaminase. The catabolism of L-methionine in these microorganisms is discussed.
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Silva, Adriana Lins, Rita De Cássia Costa Araújo, Marcos Rodrigues, Áurea Izabel Aguiar Fonseca e. Souza e Wilton Pires da Cruz. "Composting and vermicomposting residues of açaí and babassu for sustainable agriculture in Amazon". Cultura Agronômica: Revista de Ciências Agronômicas 29, n. 2 (13 luglio 2020): 217–31. http://dx.doi.org/10.32929/2446-8355.2020v29n2p217-231.
Testo completoAbstract (sommario):
Agroindustrial wastes in southeastern Amazon are abundant and there are policies encouraging proper disposal for such wastes for sustainable agriculture. In this study we compared the chemical parameters of composts resulting from composting and vermicomposting sheep manure added to agroindustrial wastes as a bulking agent. Piles of compost were created using sheep manure, fruit waste, and a bulking agent. The treatments consisted of compost piles of: Tc - sheep manure and fruit pulp; Ta - sheep manure, fruit pulp and triturated açaí seeds; Ts - sheep manure, fruit pulp and sawdust, and Tb - sheep manure, fruit pulp and babassu coconut residue. After 50 days, a fraction of the compost from each pile was transferred to vermireactors to compare processes. At the end of the experiment, samples were taken in triplicate from all treatments in both composting and vermicomposting units for chemical analysis. The assessed variables were daily temperature of compost piles and vermireators, C/N ratio, Volatile solids (VS), total kjeldahl nitrogen (TKN), total phosphorus (TP), total potassium (TK), calcium (Ca), magnesium (Mg), sulfur (S), iron (Fe), copper (Cu), zinc (Zn), manganese (Mn), boron (Bo). Sawdust-based and babassu-based compost, from composting process, has the lower time for stabilization (about 40 days), pH closer to neutral and more efficient in reducing the C:N ratio than vermicomposts. Vermicomposting process increased the concentration of almost all nutrients in treatments, except for babassu-based compost.
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Bertone, Stefano, Erwan Mazarico, Michael K. Barker, Matthew A. Siegler, Jose M. Martinez-Camacho, Colin D. Hamill, Allison K. Glantzberg e Nancy L. Chabot. "Highly Resolved Topography and Illumination at Mercury’s South Pole from MESSENGER MDIS NAC". Planetary Science Journal 4, n. 2 (1 febbraio 2023): 21. http://dx.doi.org/10.3847/psj/acaddb.
Testo completoAbstract (sommario):
Abstract Mercury’s south polar region is of particular interest since Arecibo radar measurements show many high-reflectance regions consistent with ice deposits. However, current elevation information in Mercury’s southern hemisphere is not sufficient to perform detailed modeling of the illumination and thermal conditions at these radar-bright locations and to constrain properties of the volatiles potentially residing there. In this work, we leverage previously existing elevation maps of Mercury’s surface from stereo-photogrammetry at 665 m pix−1, Mercury Dual Imaging System Narrow Angle Camera images, and Shape-from-Shading tools from the Ames Stereo Pipeline, to provide the first high-resolution topographic maps of the south pole with a resolution of 250 m pix−1 poleward of 75°S. We show that the increased resolution and level of detail provided by our new elevation model allow for a more realistic recovery of illumination conditions in Mercury’s south polar region, thus opening the way to future thermal analyses and for the characterization of potential ice and volatile deposits. We compare both the old and new topographic models to the Mercury Dual Imaging System Narrow Angle Camera images to show the higher level of fidelity with our products, and we assess the improved consistency of derived permanently shadowed regions with reflectance measurements by Arecibo’s antennas.
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Bonn, B., S. Sun, W. Haunold, R. Sitals, E. van Beesel, L. dos Santos, B. Nillius e S. Jacobi. "COMPASS – COMparative Particle formation in the Atmosphere using portable Simulation chamber Study techniques". Atmospheric Measurement Techniques 6, n. 12 (9 dicembre 2013): 3407–23. http://dx.doi.org/10.5194/amt-6-3407-2013.
Testo completoAbstract (sommario):
Abstract. In this study we report the set-up of a novel twin chamber technique that uses the comparative method and establishes an appropriate connection of atmospheric and laboratory methods to broaden the tools for investigations. It is designed to study the impact of certain parameters and gases on ambient processes, such as particle formation online, and can be applied in a large variety of conditions. The characterisation of both chambers proved that both chambers operate identically, with a residence time xT (COMPASS1) = 26.5 ± 0.3 min and xT (COMPASS2) = 26.6 ± 0.4 min, at a typical flow rate of 15 L min−1 and a gas leak rate of (1.6 ± 0.8) × 10−5 s−1. Particle loss rates were found to be larger (due to the particles' stickiness to the chamber walls), with an extrapolated maximum of 1.8 × 10−3 s−1 at 1 nm, i.e. a hundredfold of the gas leak rate. This latter value is associated with sticky non-volatile gaseous compounds, too. Comparison measurement showed no significant differences. Therefore operation under atmospheric conditions is trustworthy. To indicate the applicability and the benefit of the system, a set of experiments was conducted under different conditions, i.e. urban and remote, enhanced ozone and terpenes as well as reduced sunlight. In order to do so, an ozone lamp was applied to enhance ozone in one of two chambers; the measurement chamber was protected from radiation by a first-aid cover and volatile organic compounds (VOCs) were added using a small additional flow and a temperature-controlled oven. During the elevated ozone period, ambient particle number and volume increased substantially at urban and remote conditions, but by a different intensity. Protection of solar radiation displayed a clear negative effect on particle number, while terpene addition did cause a distinct daily pattern. E.g. adding β pinene particle number concentration rose by 13% maximum at noontime, while no significant effect was observable during darkness. Therefore, the system is a useful tool for investigating local precursors and the details of ambient particle formation at surface locations as well as potential future feedback processes.
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Alizadeh, Mahsa, David R. Weise e Thomas H. Fletcher. "Characteristics of Pyrolysis Products of California Chaparral and Their Potential Effect on Wildland Fires". Fire 7, n. 8 (5 agosto 2024): 271. http://dx.doi.org/10.3390/fire7080271.
Testo completoAbstract (sommario):
The aim of this study was to investigate the pyrolysis of selected California foliage and estimate the energy content of the released volatiles to show the significance of the pyrolysis of foliage and its role during wildland fires. While the majority of the volatiles released during the pyrolysis of foliage later combust and promote fire propagation, studies on the energy released from combustion of these compounds are scarce. Samples of chamise (Adenostoma fasciculatum), Eastwood’s manzanita (Arctostaphylos glandulosa), scrub oak (Quercus berberidifolia), hoaryleaf ceanothus (Ceanothus crassifolius), all native to southern California, and sparkleberry (Vaccinium arboreum), native to the southern U.S., were pyrolyzed at 725 °C with a heating rate of approximately 180 °C/s to mimic the conditions of wildland fires. Tar and light gases were collected and analyzed. Tar from chamise, scrub oak, ceanothus and sparkleberry was abundant in aromatics, especially phenol, while tar from manzanita was mainly composed of cycloalkenes. The four major components of light gases were CO, CO2, CH4 and H2. Estimated values for the high heating values (HHVs) of volatiles ranged between 18.9 and 23.2 (MJ/kg of biomass) with tar contributing to over 80% of the HHVs of the volatiles. Therefore, fire studies should consider the heat released from volatiles present in both tar and light gases during pyrolysis.
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Ozdikmenli, Seda, e Nukhet Nilüfer Zorba. "Uçucu Yağların Staphylococcus aureus Üzerine Etkisi". Turkish Journal of Agriculture - Food Science and Technology 2, n. 5 (22 maggio 2014): 228. http://dx.doi.org/10.24925/turjaf.v2i5.228-235.118.
Testo completoAbstract (sommario):
Diseases caused by Staphylococcus aureus are widespread through the world in spite of developing technology. S. aureus is an important pathogen causing food intoxications besides hospital infections by its antibiotic resistant strains. Nowadays, there has been worldwide increasing concern on usage of natural products to control microorganisms. One of these natural products is essential oils. They are produced from plants especially from spices and composed of many components and volatiles. This review summarizes informative literature on essential oils and their mode of antimicrobial action. In addition, current knowledge on in vitro researches on antibacterial activity of essential oils and food applications to control S. aureus has been discussed.
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Afifi, Fatma U., Violet Kasabri, Hala I. Al-Jaber, Barakat E. Abu-Irmaileh, Mahmoud A. Al-Qudah e Ismail F. Abaza. "Composition and Biological Activity of Volatile Oil from Salvia judaica and S. multicaulis from Jordan". Natural Product Communications 11, n. 4 (aprile 2016): 1934578X1601100. http://dx.doi.org/10.1177/1934578x1601100429.
Testo completoAbstract (sommario):
The aim of this work was to determine the composition of the hydro-distilled essential oil of Salvia judaica Boiss. and S. multicaulis Vahl. (Lamiaceae) from Jordan by GC and GC-MS and to report the actual composition of their fresh leaves and flowers using SPME (Solid Phase Micro-Extraction). Their dual alpha-amylase/alpha glucosidase and pancreatic lipase inhibitory activities as well as their anti-proliferative potential were screened. The aroma profile of the leaves, flowers, and flowers at pre-flowering stages of S. judaica, obtained through SPME was composed of sesquiterpene hydrocarbons (87.7 %, 71.8 %, and 86.2 %, respectively) while the hydro-distilled oil of the dry leaves was rich in oxygenated sesquiterpenes (50.8%). Fresh leaves of S. multicaulis were rich in oxygenated monoterpenes (58.1%), while monoterpene hydrocarbons dominated the blooming flowers (57.2%) and the flowers at the pre-flowering stage (64.7%). The hydro-distilled oil of the dry leaves was rich in oxygenated monoterpenes (77.6%). With doxorubicin as a positive control, no anti-proliferative activity was observed against colorectal cancer cell lines HT29, HCT116, and SW620 using SRB assay for either Salvia spp. In vitro enzymatic starch digestion was evaluated with Acarbose (IC50: 0.2± 0.0 μg /mL) as the reference drug. The respective IC50 (mg/mL) values of S. judaica and S. multicaulis aqueous extracts were 4.9 ± 0.4 and 10.3 ± 0.9. Modulation of pancreatic lipase activity (PL) was determined by colorimetry and compared with Orlistat (IC50: 0.11 ± 0.0 μg/mL). PL-IC50 values (μg/mL) obtained for S. judaica and S. multicaulis were 108.5±6.4 and 31.8 ± 0.8, respectively.
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Zagorskis, Alvydas, e Rasa Vaiškūnaitė. "An Investigation on the Efficiency of Air Purification Using a Biofilter with Activated Bed of Different Origin". Chemical and Process Engineering 35, n. 4 (1 dicembre 2014): 435–45. http://dx.doi.org/10.2478/cpe-2014-0033.
Testo completoAbstract (sommario):
Abstract Recent studies in the area of biological air treatment in filters have addressed fundamental key issues, such as a biofilter bed of different origin composed of natural zeolite granules, foam cubes and wood chips. When foam and zeolite are mixed with wood chips to remove volatile organic compounds from the air, not only biological but also adsorption air purification methods are accomplished. The use of complex purification technologies helps to improve the efficiency of a filter as well as the bed service life of the filter bed. Investigations revealed that microorganisms prevailing in biological purification, can also reproduce themselves in biofilter beds of inorganic and synthetic origin composed of natural zeolite and foam. By cultivating associations of spontaneous microorganisms in the filter bed the dependencies of the purification efficiency of filter on the origin, concentration and filtration time of injected pollutants were determined. The highest purification efficiency was obtained when air polluted with acetone vapour was supplied to the equipment at 0.1 m/s of superficial gas velocity. When cleaning air from volatile organic compounds (acetone, toluene and butanol), under the initial pollutant concentration of ~100 mg/m3, the filter efficiency reached 95 %.
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Mumpuni, A., H. S. S. Sharma e Averil E. Brown. "Effect of Metabolites Produced by Trichoderma harzianum Biotypes and Agaricus bisporus on Their Respective Growth Radii in Culture". Applied and Environmental Microbiology 64, n. 12 (1 dicembre 1998): 5053–56. http://dx.doi.org/10.1128/aem.64.12.5053-5056.1998.
Testo completoAbstract (sommario):
ABSTRACT Trichoderma harzianum biotypes Th1, Th2, and Th3 produced volatile metabolites in vitro which had similar fungistatic effects on the growth of Agaricus bisporus. Metabolites present in agar colonized by these strains also inhibited mycelial growth of A. bisporus, although the reduction in growth was less in the presence of metabolites produced by biotype Th2 than that in the presence of metabolites produced by Th1 or Th3.A. bisporus produced metabolites in liquid culture that inhibited the growth of Th1 and Th3 but stimulated the growth of Th2. A compound(s) responsible for the inhibition and stimulation was extracted from A. bisporus culture filtrate and from compost-grown fruit bodies with n-butanol, but the identity of the compound(s) was not determined. We suggest that the stimulation of Th2 by metabolites produced by A. bisporus and the relatively low level of inhibition of A. bisporus by Th2 facilitate colonization of compost by both fungi. However, as compost colonization reaches a maximum, a change in the competitive balance in favor of Th2 results in the inhibition of fruit body production by A. bisporus and the devastating green mold epidemics affecting mushroom production.
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Mariyam, Sabah, Mohammad Alherbawi, Naim Rashid, Tareq Al-Ansari e Gordon McKay. "Bio-Oil Production from Multi-Waste Biomass Co-Pyrolysis Using Analytical Py–GC/MS". Energies 15, n. 19 (9 ottobre 2022): 7409. http://dx.doi.org/10.3390/en15197409.
Testo completoAbstract (sommario):
Background: Bioenergy attracts much attention due to the global demand for renewable and sustainable energy resources. Waste biomass feedstocks—date pits, coffee waste, and cow dung—require efficient and environmentally friendly waste-management technologies such as pyrolysis. Fast pyrolysis occurs at fast heating rates (10–100 °C/s), generates high bio-oil yields, and is the most widely used process for biofuel generation. The aim of the study is to compare the effect of pyrolysis between single, binary, and ternary feeds on thermal degradation behavior and bio-oil composition. Methods: Thermogravimetric analysis (TGA) was conducted at 30 °C/min from room temperature to 850 °C to understand the thermal degradation behavior of the biomasses. A Pyroprobe® reactor—a micro-scale pyrolyzer—was used to conduct the fast pyrolysis at 500 °C with a heating rate of 10 °C/s, and the volatile contents were quantified using a gas chromatograph–mass spectrometer (GC/MS). Results: The (TGA) showed three main stages of decomposition following dehydration, devolatilization, and char degradation for the different single and multiple feeds. According to the identified compounds, the bio-oil components are broadly identified as aldehydes, amines, aliphatic, aromatics, alcohols, furans, ketones, and acids. The three single-biomass pyrolysis products have four compounds in common, acetic acid and ketone groups (acetic acid, 2-propanone, 1-hydroxy-, benzyl methyl ketone, and 1,2-cyclopentanedione). Conclusion: The bio-oil generated from the feeds comprises great potential for volatiles, diesel, and gasoline production with carbon atoms ranging from C2–C33. Future studies should focus on understanding the effect of procedural parameters, including blending ratio, temperature, and heating rates, on bio-oil composition. Additional molecular techniques should be employed to understand biomass components’ reaction mechanisms to produce useful bio-oil products.
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Sun, Zhong Liang, Feng Xia Liu, Xian Qun Luo, Yu Cang Zhang e Jing Xu. "Volatile Constituents of the Ligarine Extract of Eupatoriurn odoraturn". Advanced Materials Research 726-731 (agosto 2013): 245–49. http://dx.doi.org/10.4028/www.scientific.net/amr.726-731.245.
Testo completoAbstract (sommario):
Eupatoriurn odoratumaerial parts were extracted with ligarine and the volatile constituents isolated were analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Volatile constituents were isolated from the ground aerial parts ofE. odoratumby ligarine extraction and analyzed by gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). As a result, a total of fifteen compounds represented all of the extract were identified, amongst nine of fifteen compounds were sesquiterpenes. Esters and sesquiterpenes were found to compose three major chemotype accounted for 58.58% and 30.80% of the constituents, respectively. The main components was demonstrated to be dibutyl phthalate (39.73%), 11,14,17-eicosatrienoic acid, methyl ester (13.20%), (S)-spiro [4.nona-1,6-diene (6.80%), 1,2-benzenedicarboxylic acid, bis (2-methylpropyl) ester (5.65%) andcis-Z-α-bisabolene epoxide (5.56%). In addition, some pharmaceutical components such as α-cadinol and germacrene D were discovered. Antioxidant activity of the extract was assessed by the free radical scavenging (DPPH). The study offers theoretic basis for pharmaceutical utilization of the medicinal plantE. odoratum.
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Štefániková, Jana, Július Árvay, Michal Miškeje e Miroslava Kačániová. "Determination of volatile organic compounds in Slovak bryndza cheese by the electronic nose and the headspace solid-phase microextraction gas chromatography-mass spectrometry". Potravinarstvo Slovak Journal of Food Sciences 14 (28 settembre 2020): 767–73. http://dx.doi.org/10.5219/1300.
Testo completoAbstract (sommario):
The aim of the present study was to describe volatile organic compounds of the traditional Slovak bryndza cheese determined by using an electronic nose (e-nose) and a gas chromatography mass spectrometry (GCMS) with head-space solid phase microextraction (HS-SPME). For the first time, e-nose based on the gas chromatography principle with a flame ionization detector was described to identify and quantify aroma active compounds of bryndza cheese from Slovakia. The e-nose detects aroma compounds of very small concentrations in real-time of a few minutes and identifies them by comparing Kovats´ retention indices with the NIST library. Bryndza cheese produced from unpasteurized ewe´s milk and from a mixture of raw ewe´s and pasteurized cow´s types of milk were collected from 2 different Slovak farms beginning in May through to September 2019. The flavour and aroma of bryndza cheese are apparently composed of compounds contained in milk and the products of fermentation of the substrate by bacteria and fungi. Regarding volatile organic compounds, 25 compounds were detected and identified by an electronic nose with a discriminant >0.900 with ethyl acetate, isopentyl acetate, 2-butanone, acetic acid, butanoic acid, and butane-2,3-dione confirmed by gas chromatography. We confirm the suitability of the electronic nose to be used for monitoring of bryndza cheese quality.
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Lindholm, Espen E., Erlend Aune, Camilla B. Norén, Ingebjørg Seljeflot, Thomas Hayes, Jan E. Otterstad e Knut A. Kirkeboen. "The Anesthesia in Abdominal Aortic Surgery (ABSENT) Study". Anesthesiology 119, n. 4 (1 ottobre 2013): 802–12. http://dx.doi.org/10.1097/aln.0b013e31829bd883.
Testo completoAbstract (sommario):
Abstract Background: On the basis of data indicating that volatile anesthetics induce cardioprotection in cardiac surgery, current guidelines recommend volatile anesthetics for maintenance of general anesthesia during noncardiac surgery in hemodynamic stable patients at risk for perioperative myocardial ischemia. The aim of the current study was to compare increased troponin T (TnT) values in patients receiving sevoflurane-based anesthesia or total intravenous anesthesia in elective abdominal aortic surgery. Methods: A prospective, randomized, open, parallel-group trial comparing sevoflurane-based anesthesia (group S) and total intravenous anesthesia (group T) with regard to cardioprotection in 193 patients scheduled for elective abdominal aortic surgery. Increased TnT level on the first postoperative day was the primary endpoint. Secondary endpoints were postoperative complications, nonfatal coronary events and mortality. Results: On the first postoperative day increased TnT values (>13 ng/l) were found in 43 (44%) patients in group S versus 41 (43%) in group T (P = 0.999), with no significant differences in TnT levels between the groups at any time point. Although underpowered, the authors found no differences in postoperative complications, nonfatal coronary events or mortality between the groups. Conclusions: In elective abdominal aortic surgery sevoflurane-based anesthesia did not reduce myocardial injury, evaluated by TnT release, compared with total intravenous anesthesia. These data indicate that potential cardioprotective effects of volatile anesthetics found in cardiac surgery are less obvious in major vascular surgery.
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Zhao, Ting, Ming Qiang Zhou, Wei Li Liu, Wei Huang, Jun Zhi He, Hai Tao Chi e Xia Gao. "Determination of Elements in Carbon Fiber Using Inductively Coupled Plasma Mass Spectrometry (ICP-MS)". Applied Mechanics and Materials 423-426 (settembre 2013): 767–70. http://dx.doi.org/10.4028/www.scientific.net/amm.423-426.767.
Testo completoAbstract (sommario):
Based on microwave digestion and dry digestion, the concentrations of Si, S, Ca, Cr, Fe, Ni, Cu, Al, Mo, Sb, Ti, V, Y and Zn in carbon fiber were determined using inductively coupled plasma mass spectrometry (ICP-MS). Compare with the concentrations in the solution got by microwave digestion, the concentrations in the solution got by dry digestion are higher. And microwave digestion is more suitable for treatment of carbon fiber containing volatile elements than dry digestion.
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Amoah, Papa K., Zeinab Mohammed Hassan, Pengtao Lin, Engelbert Redel, Helmut Baumgart e Yaw S. Obeng. "Broadband Dielectric Spectroscopic Detection of Ethanol: A Side-by-Side Comparison of ZnO and HKUST-1 MOFs as Sensing Media". Chemosensors 10, n. 7 (25 giugno 2022): 241. http://dx.doi.org/10.3390/chemosensors10070241.
Testo completoAbstract (sommario):
The most common gas sensors are based on chemically induced changes in electrical resistivity and necessarily involve making imperfect electrical contacts to the sensing materials, which introduce errors into the measurements. We leverage thermal- and chemical-induced changes in microwave propagation characteristics (i.e., S-parameters) to compare ZnO and surface-anchored metal–organic-framework (HKUST-1 MOF) thin films as sensing materials for detecting ethanol vapor, a typical volatile organic compound (VOC), at low temperatures. We show that the microwave propagation technique can detect ethanol at relatively low temperatures (<100 °C), and afford new mechanistic insights that are inaccessible with the traditional dc-resistance-based measurements. In addition, the metrological technique avoids the inimical measurand distortions due to parasitic electrical effects inherent in the conductometric volatile organic compound detection.
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Korenika, Ana-Marija Jagatić, Ivana Tomaz, Darko Preiner, Marina Lavrić, Branimir Šimić e Ana Jeromel. "Influence of L. thermotolerans and S. cerevisiae Commercial Yeast Sequential Inoculation on Aroma Composition of Red Wines (Cv Trnjak, Babic, Blatina and Frankovka)". Fermentation 7, n. 1 (31 dicembre 2020): 4. http://dx.doi.org/10.3390/fermentation7010004.
Testo completoAbstract (sommario):
Even though Saccharomyces cerevisiae starter cultures are still largely used nowadays, the non-Saccharomyces contribution is re-evaluated, showing positive enological characteristics. Among them, Lachancea thermotolerans is one of the key yeast species that are desired for their contribution to wine sensory characteristics. The main goal of this work was to explore the impact of L. thermotolerans commercial yeast strain used in sequential inoculation with S. cerevisiae commercial yeast on the main enological parameters and volatile aroma profile of Trnjak, Babić, Blatina, and Frankovka red wines and compare it with wines produced by the use of S. cerevisiae commercial yeast strain. In all sequential fermented wines, lactic acid concentrations were significantly higher, ranging from 0.20 mg/L in Trnjak up to 0.92 mg/L in Frankovka wines, while reducing alcohol levels from 0.1% v/v in Trnjak up to 0.9% v/v in Frankovka wines. Among volatile compounds, a significant increase of ethyl lactate and isobutyl acetate, geraniol, and geranyl acetate was detected in all wines made by use of L. thermotolerans. In Babić wines, the strongest influence of sequential fermentation was connected with higher total terpenes and total ester concentrations, while Trnjak sequentially fermented wines stood up with higher total aldehyde, volatile phenol, and total lactone concentrations. Control wines, regardless of variety, stood up with higher concentrations of total higher alcohols, especially isoamyl alcohol. The present work contributed to a better understanding of the fermentation possibilities of selected non-Saccharomyces strains in the overall red wine quality modeling.
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Gillings, M. R., M. P. Holley e M. Selleck. "Molecular identification of species comprising an unusual biofilm from a groundwater treatment plant". Biofilms 3, n. 1 (gennaio 2006): 19–24. http://dx.doi.org/10.1017/s1479050507002098.
Testo completoAbstract (sommario):
ABSTRACTOrica's groundwater treatment plant in Botany, NSW, Australia, was designed to remove and destroy volatile organic compounds from polluted groundwater and to treat the water for reuse on the Botany Industrial Park. The initial steps in this process involved acidification of the groundwater and air stripping. During this operation, very large quantities of a biofilm formed within the air stripper, necessitating weekly clean-outs. We investigated the composition of this biofilm using molecular methods. Total DNA extracted from biofilm material was used as a template for amplification of both bacterial 16 S ribosomal DNA (rDNA) and the eukaryotic rDNA internal transcribed spacer region. Cloning and sequencing of these products showed that the biofilm was composed primarily of a bacterium belonging to the genusAcidocella, a filamentous fungus (Trichoderma asperellum), and the ascomycetous yeastsPichia,CandidaandGeotrichum. This unusual biofilm was composed of acidophiles that were capable of rapidly generating large amounts of biomass under these conditions. When acidification of the groundwater ceased, the biofilm no longer formed.
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Pastink, Margreet I., Bas Teusink, Pascal Hols, Sanne Visser, Willem M. de Vos e Jeroen Hugenholtz. "Genome-Scale Model of Streptococcus thermophilus LMG18311 for Metabolic Comparison of Lactic Acid Bacteria". Applied and Environmental Microbiology 75, n. 11 (3 aprile 2009): 3627–33. http://dx.doi.org/10.1128/aem.00138-09.
Testo completoAbstract (sommario):
ABSTRACT In this report, we describe the amino acid metabolism and amino acid dependency of the dairy bacterium Streptococcus thermophilus LMG18311 and compare them with those of two other characterized lactic acid bacteria, Lactococcus lactis and Lactobacillus plantarum. Through the construction of a genome-scale metabolic model of S. thermophilus, the metabolic differences between the three bacteria were visualized by direct projection on a metabolic map. The comparative analysis revealed the minimal amino acid auxotrophy (only histidine and methionine or cysteine) of S. thermophilus LMG18311 and the broad variety of volatiles produced from amino acids compared to the other two bacteria. It also revealed the limited number of pyruvate branches, forcing this strain to use the homofermentative metabolism for growth optimization. In addition, some industrially relevant features could be identified in S. thermophilus, such as the unique pathway for acetaldehyde (yogurt flavor) production and the absence of a complete pentose phosphate pathway.
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Nikolova, Irina, A. Rob MacKenzie, Xiaoming Cai, Mohammed S. Alam e Roy M. Harrison. "Modelling component evaporation and composition change of traffic-induced ultrafine particles during travel from street canyon to urban background". Faraday Discussions 189 (2016): 529–46. http://dx.doi.org/10.1039/c5fd00164a.
Testo completoAbstract (sommario):
We developed a model (CiTTy-Street-UFP) of traffic-related particle behaviour in a street canyon and in the nearby downwind urban background that accounts for aerosol dynamics and the variable vapour pressure of component organics. The model simulates the evolution and fate of traffic generated multicomponent ultrafine particles (UFP) composed of a non-volatile core and 17 Semi-Volatile Organic Compounds (SVOC, modelled asn-alkane proxies). A two-stage modelling approach is adopted: (1) a steady state simulation inside the street canyon is achieved, in which there exists a balance between traffic emissions, condensation/evaporation, deposition, coagulation and exchange with the air above roof-level; and (2) a continuing simulation of the above-roof air parcel advected to the nearby urban park during which evaporation is dominant. We evaluate the component evaporation and associated composition changes of multicomponent organic particles in realistic atmospheric conditions and compare our results with observations from London (UK) in a street canyon and an urban park. With plausible input conditions and parameter settings, the model can reproduce, with reasonable fidelity, size distributions in central London in 2007. The modelled nucleation-mode peak diameter, which is 23 nm in the steady-state street canyon, decreases to 9 nm in a travel time of just 120 s. All modelled SVOC in the sub-10 nm particle size range have evaporated leaving behind only non-volatile material, whereas modelled particle composition in the Aitken mode contains SVOC between C26H54and C32H66. No data on particle composition are available in the study used for validation, or elsewhere. Measurements addressing in detail the size resolved composition of the traffic emitted UFP in the atmosphere are a high priority for future research. Such data would improve the representation of these particles in dispersion models and provide the data essential for model validation. Enhanced knowledge of the chemical composition of nucleation-mode particles from diesel engine exhaust is needed to predict both their atmospheric behaviour and their implications for human health.
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Lappia, Hanna E., e Raimo J. Alén. "Pyrolysis of crude tall oil-derived products". BioResources 6, n. 4 (28 ottobre 2011): 5121–38. http://dx.doi.org/10.15376/biores.6.4.5121-5138.
Testo completoAbstract (sommario):
Crude tall oil (CTO) soap, purified and neutralised CTO, and neutralised distilled tall oil (DTO) were pyrolysed (at 750ºC for 20 s) by pyrolysis gas chromatography with mass-selective and flame ionisation detection (Py-GC/MSD and FID) to clarify their thermochemical behaviour. In each case, the pyrolysates were characteristically dependent on the feedstock, and a wide range of volatile aliphatic and aromatic compounds with some chemically bound oxygen formed. The CTO soap pyrolysate was typically composed of initial extractives-type compounds together with a significant amount of unsaturated aliphatic hydrocarbons and aromatics, whereas the DTO pyrolysate contained mostly just unsaturated aliphatic hydrocarbons and aromatics. These data are of importance when considering the suitability of various extractives-derived resources for producing bioliquids and chemicals.
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Zampetti, Emiliano, Paolo Papa, Joshua Avossa, Andrea Bearzotti, Catia Balducci, Giovanna Tranfo e Antonella Macagnano. "Low-Cost Benzene Toluene Xylene Measurement Gas System Based on the Mini Chromatographic Cartridge". Sensors 21, n. 1 (28 dicembre 2020): 125. http://dx.doi.org/10.3390/s21010125.
Testo completoAbstract (sommario):
Benzene, toluene and xylene (BTX) are an important part of the volatile organic compounds (VOCs) to be detected and monitored in the air, due to their toxicity towards human health. One of the most reliable technique used in BTX detection is gas chromatography (GC), which presents a high sensitivity. On the other hand, it has important drawbacks, such as high costs, the need for qualified personnel and frequent maintenance. To overcome these drawbacks, this work reports the development of a low cost and portable BTX gas detection system based on a mini chromatographic cartridge, a photo ionization detector (PID), a simple control unit (based on Arduino architecture) and a mini pump. In order to separate the BTX components, we propose the use of a cartridge 80 mm in length, composed of several commercial chromatographic column sections. To test the system performances, we have injected different amounts (from about 0.3 to 5.3 µg) of benzene, toluene and xylene and two of the most frequent possible interferents (ethanol, acetone). Experimental results have shown different retention time values (i.e., 25 ± 0.5 s, 51 ± 1.2 s and 117 ± 4 s, respectively) for benzene, toluene and xylene.
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Yi, Yujun, Caihong Tang, Zhifeng Yang, Shanghong Zhang e Cheng Zhang. "A One-Dimensional Hydrodynamic and Water Quality Model for a Water Transfer Project with Multihydraulic Structures". Mathematical Problems in Engineering 2017 (2017): 1–11. http://dx.doi.org/10.1155/2017/2656191.
Testo completoAbstract (sommario):
The long Middle Route of the South to North Water Transfer Project is composed of complex hydraulic structures (aqueduct, tunnel, control gate, diversion, culvert, and diverted siphon), which generate complex flow patterns. It is vital to simulate the flow patterns through hydraulic structures, but it is a challenging work to protect water quality and maintain continuous water transfer. A one-dimensional hydrodynamic and water quality model was built to understand the flow and pollutant movement in this project. Preissmann four-point partial-node implicit scheme was used to solve the governing equations in this study. Water flow and pollutant movement were appropriately simulated and the results indicated that this water quality model was comparable to MIKE 11 and had a good performance and accuracy. Simulation accuracy and model uncertainty were analyzed. Based on the validated water quality model, six pollution scenarios (Q1 = 10 m3/s, Q2 = 30 m3/s, and Q3 = 60 m3/s for volatile phenol (VOP) and contaminant mercury (Hg)) were simulated for the MRP. Emergent pollution accidents were forecasted and changes of water quality were analyzed according to the simulations results, which helped to guarantee continuously transferring water for a large water transfer project.
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Devi Andriani, Luta, Siregar Maimunah e Wahyuni Sri Br. PA. "Growth response of shallot (Allium ascalonicum L.) varieties on municipal waste compost application". Jurnal Pertanian Tropik 7, n. 1 (11 aprile 2020): 121–25. http://dx.doi.org/10.32734/jpt.v7i1.3709.
Testo completoAbstract (sommario):
Growth of shallot plants could be increased through good plant cultivation such as using organic materials that can improve physical, chemical and biological properties in the soil and contain macro and micronutrients so that organic matter is needed in the form of municipal waste compost. The research objective was to study the responsiveness of the growth of onion varieties due to the application of municipal waste compost. This research was carried out in the Bandar Senembah village Binjai district Barat in February-March 2019. The study used a randomized block design (RAK) with 2 factors and 3 blocks. The first factor is the variety (V) and the second factor is Municipal waste compost (K). The results showed that that the best varieties are varieties Bima Brebes. Where the variety showed the highest leaf length per sample and highest number of tillers per sample while the application of municipal waste compost does not show a significant effect on parameters of leaf length per sample but for the number of tillers per sample shows a significant effect where the best results in the application of 3 kg/m2 (plot) municipal waste compost. REFERENCES Ahmed, M. E., El-Kader, N. I. A. & Derbala, A.A.E. (2009). Effect of Irrigation Frequency and Potassium Source on the Productivity, Quality, and Storability of Garlic. Australian Journal Of Basic and Applied Sciences, 3(4), 4490–4497. Alfian, D. F., Nelvia & Yetti, H. (2015). The Effect of Potassium Fertilizer and Compost Mixture of Oil Palm Empty Bunches with Boiler Ash on Growth and Yield of Onion (Allium ascalonicum L.). Jurnal Agroekoteknologi, 5(2), 1-6. Amiroh, A. (2017). Pengaplikasian dosis pupuk bokashi dan KNO3 terhadap pertumbuhan dan hasil tanaman melon (Cucumis melo L.). Jurnal Saintis, 9(1), 25 - 36. Arisha, H. M. E.,. Ibraheim, S. K. A & El-Sarkassy, N. M. (2017). The response of garlic (Allium sativum L.) yield, volatile oil, and nitrate content to foliar and soil application of potassium fertilizer under sandy soil conditions. Middle East Journal of Applied Sciences, 7(1), 44-56. Aslamiah, I. D., dan Sularno. (2017). The response of growth and production of peanut plants of the addition of organic fertilizer concentration and reduction of an organic fertilizer dosage. Prosiding Seminas Nasional Fakultas Pertanian UMJ. BPS. (2018). Statistik Indonesia. Badan Pusat Statistik Republik Indonesia, Jakarta. Gunadi, N. (2009). Kalium sulfat dan kalium klorida sebagai sumber pupuk kalium pada tanaman bawang merah. Jurnal Hortikultura, 19(2),174-185. Hickey, M. (2012). Growing Garlic in NSW Second Edition. Primefact 259. Department of Primary Industries. NSW Government. Australia. Hilal, M.H., Selim, A.M. & El-Neklawy, A.S. (1992). Enhancing and retarding effect of combined sulfur and fertilizer applications on crop production in different soils. In Proceedings Middle East Sulphur Symposium 12-16 February, Cairo, Egypt. Marschner, P.( 2012). Mineral Nutrition of Higher Plants Third Edition. Elsevier Ltd. Oxford. Nainwal, R. C., Sigh, D., Katiyar, R. S., Sharma, I & Tewari, S. K. (2015). The response of garlic to integrated nutrient management practices in a sodic soil of Uttar Pradesh, India. Journal of Spices and Aromatic Crops, 24(1), 33-36. Putra, A. A. G. (2013). Kajian aplikasi dosis pupuk ZA dan kalium pada tanaman bawang putih (Allium sativum L.). Jurnal Ganec Swara, 7(2), 10–18. Setiawati, W., Murtiningsih, R., Sopha, G. A & Handayani, T. (2007). Petunjuk Teknis Budidaya Tanaman Sayuran. Balai Penelitian Tanaman Sayuran. Shafeek, M. R., Nagwa, M. H., Singer, S. M., & El-Greadly, N. H. (2013). Effect of potassium fertilizer and foliar spraying with Ethereal on plant development, yield, and bulb quality of onion plants (Allium cepa L). Journal of Applied Sciences Research, 9(2), 1140-1146. Sholihin, Y., Suminar, E., Rizky, W.H. & Pitaloka, G.G. (2016). Meristem explants growth of garlic (Allium sativum L.) Cv. tawangmangu on various compositions of kinetin and ga3 in vitro. Jurnal Kultivasi, 15(3), 172–179. Sulichantini, E. D. (2016). Effect of plant growth regulator Concentration Against Regeneration Garlic (Allium sativum L) In the Tissue Culture.. Jurnal Agrifor, 15(1), 29–38. Suminarti, N.E. (2010). The Effects of N and K Fertilization on the Growth and Yield of Taro on Dry Land. Akta Agrosia, 13(1), 1–7. Uke, K. H. Y., Barus, H & Madauna, I. W. (2015). Effect of Tuber Sizes and Potassium Dosages on Growth and Production of Shallots var. Lembah Palu. Jurnal Agrotekbis, 3(6), 655 - 661. Utomo, P.S & Suprianto, A. (2019). Respon pertumbuhan dan produksi tanaman bawang merah (Allium ascalonicum L.) varietas thailand terhadap perlakuan dosis pupuk kusuma bioplus dan KNO3 putih. Jurnal Ilmiah Hijau Cendekia, 4(1), 28–34. Wu, C., Wang, M., Cheng, Z & Meng, H. (2016). The response of garlic (Allium sativum L.) bolting and bulbing to temperature and photoperiod treatments. Biol Open, 5(4), 507-518.
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Declerck, Christ, Zak Hillel, Henry Shih, Maxine Kuroda, Cliff P. Connery e Daniel M. Thys. "A Comparison of Left Ventricular Performance Indices Measured by Transesophageal Echocardiography with Automated Border Detection". Anesthesiology 89, n. 2 (1 agosto 1998): 341–49. http://dx.doi.org/10.1097/00000542-199808000-00009.
Testo completoAbstract (sommario):
Background Automated border detection (ABD) allows semiautomated measurement of left ventricular (LV) areas. They can be combined with left ventricular pressure signals to generate pressure-area loops and pressure-dimension indices of contractility. This study compared conventional indices of ventricular performance (fractional area change [FAC] and circumferential fiber shortening [Vcfc]) with pressure-dimension indices of contractility. A secondary aim was to compare the effects of volatile anesthetics on the indices. Methods Using transesophageal echocardiography with automated border detection, FAC and Vcfc were obtained in 23 patients after cardiopulmonary bypass. Left ventricular pressures were obtained with a left ventricular catheter. Preload reduction by inferior vena caval occlusion was used to obtain end-systolic elastance (Ees), preload recruitable stroke force (PRSF), and dP/dtmax x EDA(-1) (EDA = end-diastolic area). In 11 patients, the measurements were repeated at 1 end-tidal minimum alveolar concentration of halothane or isoflurane. The results are expressed as mean +/- SD. Results After cardiopulmonary bypass, FAC was 31.1+/-7.9%, Vcfc was 0.6+/-0.2 circ x s(-1), Ees was 25.8+/-11.6 mmHg x cm(-2), PRSF was 60.8+/-26.6 mmHg, and dP/dtmax x EDA(-1) was 245+/-123.4 mmHg x s(-1) x cm(-2). At 1 minimum alveolar concentration of a volatile anesthetic agent, FAC, Vcfc, and dP/dtmax x EDA(-1) remained unchanged. Significant decreases in Ees (19%) and PRSF (28%) were observed. Conclusions The association between pressure-dimension indices and Vcfc or FAC was weak or nonexistent. A reduction in myocardial contractility induced by the administration of volatile anesthetic agents was detected by Ees and PRSF, but not by FAC, Vcfc, or dP/dtmax x EDA(-1). After myocardial revascularization, Ees and PRSF appear more sensitive than FAC or Vcfc for measuring changes in contractility.
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He, Zhishu, Hao Zhang, Tao Wang, Ren Wang e Xiaohu Luo. "Effects of Five Different Lactic Acid Bacteria on Bioactive Components and Volatile Compounds of Oat". Foods 11, n. 20 (16 ottobre 2022): 3230. http://dx.doi.org/10.3390/foods11203230.
Testo completoAbstract (sommario):
In this research, oats were fermented with Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus for 48 h at 37 °C. The purpose of this work was to compare the growth capacities of the five lactic acid bacteria (LAB) in the oat matrix and the effects of fermentation on the contents of the bioactive components of oat, such as β-glucan, polyphenols, flavonoids and volatile compounds at different time (0, 4, 8, 12, 24, 36 and 48 h). After 48 h of fermentation, the number of living L. acidophilus in oat reached 7.05 × 109 cfu/mL, much higher than that of other strains. S. thermophilus retained the greatest β-glucan content, and L. casei had increased total polyphenol and total flavonoid contents. The proportion of free and bound polyphenols and flavonoids in all samples was changed by microbial action, indicating that forms of polyphenols and flavonoids can be transformed during the fermentation process, and the changes varied with different strains. The samples with L. plantarum, L. acidophilus, and L. casei fermentation contained more alcohols, whereas those with S. thermophilus and L. bulgaricus fermentation had more aldehydes, which revealed that the composition of volatile components was related to strains. The results indicate that oat substrate is a good medium for LAB growth. This study provides a reference for the use of different strains to achieve different fermentation purposes and a theoretical basis for the further processing of oat and fermented oat beverages.
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Gottwald, Timothy, Gavin Poole, Earl Taylor, Weiqi Luo, Drew Posny, Scott Adkins, William Schneider e Neil McRoberts. "Canine Olfactory Detection of a Non-Systemic Phytobacterial Citrus Pathogen of International Quarantine Significance". Entropy 22, n. 11 (9 novembre 2020): 1269. http://dx.doi.org/10.3390/e22111269.
Testo completoAbstract (sommario):
For millennia humans have benefitted from application of the acute canine sense of smell to hunt, track and find targets of importance. In this report, canines were evaluated for their ability to detect the severe exotic phytobacterial arboreal pathogen Xanthomonas citri pv. citri (Xcc), which is the causal agent of Asiatic citrus canker (Acc). Since Xcc causes only local lesions, infections are non-systemic, limiting the use of serological and molecular diagnostic tools for field-level detection. This necessitates reliance on human visual surveys for Acc symptoms, which is highly inefficient at low disease incidence, and thus for early detection. In simulated orchards the overall combined performance metrics for a pair of canines were 0.9856, 0.9974, 0.9257 and 0.9970, for sensitivity, specificity, precision, and accuracy, respectively, with 1–2 s/tree detection time. Detection of trace Xcc infections on commercial packinghouse fruit resulted in 0.7313, 0.9947, 0.8750, and 0.9821 for the same performance metrics across a range of cartons with 0–10% Xcc-infected fruit despite the noisy, hot and potentially distracting environment. In orchards, the sensitivity of canines increased with lesion incidence, whereas the specificity and overall accuracy was >0.99 across all incidence levels; i.e., false positive rates were uniformly low. Canines also alerted to a range of 1–12-week-old infections with equal accuracy. When trained to either Xcc-infected trees or Xcc axenic cultures, canines inherently detected the homologous and heterologous targets, suggesting they can detect Xcc directly rather than only volatiles produced by the host following infection. Canines were able to detect the Xcc scent signature at very low concentrations (10,000× less than 1 bacterial cell per sample), which implies that the scent signature is composed of bacterial cell volatile organic compound constituents or exudates that occur at concentrations many fold that of the bacterial cells. The results imply that canines can be trained as viable early detectors of Xcc and deployed across citrus orchards, packinghouses, and nurseries.
35
Paśko, Paweł, Agnieszka Galanty, Tomasz Dymerski, Young-Mo Kim, Yong-Seo Park, Patricia Cabrales-Arellano, Victor Velazquez Martinez et al. "Physicochemical and Volatile Compounds Analysis of Fruit Wines Fermented with Saccharomyces cerevisiae: FTIR and Microscopy Study with Focus on Anti-Inflammatory Potential". International Journal of Molecular Sciences 25, n. 11 (22 maggio 2024): 5627. http://dx.doi.org/10.3390/ijms25115627.
Testo completoAbstract (sommario):
The growing trend in fruit wine production reflects consumers’ interest in novel, diverse drinking experiences and the increasing demand for healthier beverage options. Fruit wines made from kiwi, pomegranates, and persimmons fermented using S. bayanus Lalvin strain EC1118 demonstrate the versatility of winemaking techniques. Kiwifruit, persimmon, and pomegranate wines were analyzed using HPLC and GC-TOFMS analyses to determine their concentrations of phenolic acids and volatile compounds. These results were supported by Fourier transform infrared (FTIR) spectroscopy to characterize and compare chemical shifts in the polyphenol regions of these wines. The wines’ characterization included an anti-inflammatory assay based on NO, TNF-alpha, and IL-6 production in the RAW 264.7 macrophage model. FTIR spectroscopy predicted the antioxidant and phenolic contents in the wines. In terms of polyphenols, predominantly represented by chlorogenic, caffeic, and gallic acids, pomegranate and kiwifruit wines showed greater benefits. However, kiwifruit wines exhibited a highly diverse profile of volatile compounds. Further analysis is necessary, particularly regarding the use of other microorganisms in the fermentation process and non-Saccharomyces strains methods. These wines exhibit high biological antioxidant potential and health properties, providing valuable insights for future endeavors focused on designing healthy functional food products.
36
Sheraz, Muhammad, Silvia Dedu e Vasile Preda. "Volatility Dynamics of Non-Linear Volatile Time Series and Analysis of Information Flow: Evidence from Cryptocurrency Data". Entropy 24, n. 10 (2 ottobre 2022): 1410. http://dx.doi.org/10.3390/e24101410.
Testo completoAbstract (sommario):
This paper aims to empirically examine long memory and bi-directional information flow between estimated volatilities of highly volatile time series datasets of five cryptocurrencies. We propose the employment of Garman and Klass (GK), Parkinson’s, Rogers and Satchell (RS), and Garman and Klass-Yang and Zhang (GK-YZ), and Open-High-Low-Close (OHLC) volatility estimators to estimate cryptocurrencies’ volatilities. The study applies methods such as mutual information, transfer entropy (TE), effective transfer entropy (ETE), and Rényi transfer entropy (RTE) to quantify the information flow between estimated volatilities. Additionally, Hurst exponent computations examine the existence of long memory in log returns and OHLC volatilities based on simple R/S, corrected R/S, empirical, corrected empirical, and theoretical methods. Our results confirm the long-run dependence and non-linear behavior of all cryptocurrency’s log returns and volatilities. In our analysis, TE and ETE estimates are statistically significant for all OHLC estimates. We report the highest information flow from BTC to LTC volatility (RS). Similarly, BNB and XRP share the most prominent information flow between volatilities estimated by GK, Parkinson’s, and GK-YZ. The study presents the practicable addition of OHLC volatility estimators for quantifying the information flow and provides an additional choice to compare with other volatility estimators, such as stochastic volatility models.
37
Lembcke, G., e F. Zemlin. "Projected Structure of the Surface Protein of Sulfolobus Spec. B12 Determined to a Resolution of 1.0 NM by Cryo-Electronmicroscopy". Proceedings, annual meeting, Electron Microscopy Society of America 48, n. 1 (12 agosto 1990): 102–3. http://dx.doi.org/10.1017/s0424820100179269.
Testo completoAbstract (sommario):
The thermoacidophilic archaebacterium Sulfolobus spec. B12 , which is closely related to Sulfolobus solfataricus , possesses a regularly arrayed surface protein (S-layer), which is linked to the plasma membrane via spacer elements spanning a distinct interspace of approximately 18 nm. The S-layer has p3-Symmetry and a lattice constant of 21 nm; three-dimensional reconstructions of negatively stained fragments yield a layer thickness of approximately 6-7 nm.For analysing the molecular architecture of Sulfolobus surface protein in greater detail we use aurothioglucose(ATG)-embedding for specimen preparation. Like glucose, ATG, is supposed to mimic the effect of water, but has the advantage of being less volatile. ATG has advantages over glucose when working with specimens composed exclusively of protein because of its higher density of 2.92 g cm-3. Because of its high radiation sensitivity electromicrographs has to be recorded under strict low-dose conditions. We have recorded electromicrographs with a liquid helium-cooled superconducting electron microscope (the socalled SULEIKA at the Fritz-Haber-lnstitut) with a specimen temperature of 4.5 K and with a maximum dose of 2000 e nm-2 avoiding any pre-irradiation of the specimen.
38
Mousis, O., A. Aguichine, R. Helled, P. G. J. Irwin e J. I. Lunine. "The role of ice lines in the formation of Uranus and Neptune". Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 378, n. 2187 (9 novembre 2020): 20200107. http://dx.doi.org/10.1098/rsta.2020.0107.
Testo completoAbstract (sommario):
We aim at investigating whether the chemical composition of the outer region of the protosolar nebula can be consistent with current estimates of the elemental abundances in the ice giants. To do so, we use a self-consistent evolutionary disc and transport model to investigate the time and radial distributions of H 2 O, CO, CO 2 , CH 3 OH, CH 4 , N 2 and H 2 S, i.e. the main O-, C-, N and S-bearing volatiles in the outer disc. We show that it is impossible to accrete a mixture composed of gas and solids from the disc with a C/H ratio presenting enrichments comparable to the measurements (approx. 70 times protosolar). We also find that the C/N and C/S ratios measured in Uranus and Neptune are compatible with those acquired by building blocks agglomerated from solids condensed in the 10–20 AU region of the protosolar nebula. By contrast, the presence of protosolar C/N and C/S ratios in Uranus and Neptune would imply that their building blocks agglomerated from particles condensed at larger heliocentric distances. Our study outlines the importance of measuring the elemental abundances in the ice giant atmospheres, as they can be used to trace the planetary formation location, the origin of their building blocks and/or the chemical and physical conditions of the protosolar nebula. This article is part of a discussion meeting issue ‘Future exploration of ice giant systems’.
39
Diep, Tung Thanh, Michelle Ji Yeon Yoo, Chris Pook, Saeedeh Sadooghy-Saraby, Abhishek Gite e Elaine Rush. "Volatile Components and Preliminary Antibacterial Activity of Tamarillo (Solanum betaceum Cav.)". Foods 10, n. 9 (17 settembre 2021): 2212. http://dx.doi.org/10.3390/foods10092212.
Testo completoAbstract (sommario):
Tamarillo is a nutrient-dense fruit with a unique aroma from its volatile compounds (VCs). In this study, we aimed to compare the volatile profiles: (i) of fresh and freeze-dried tamarillo; (ii) detected using Thermal Desorption–Gas Chromatography–Mass Spectrometry (TD–GC–MS) and Solid-Phase MicroExtraction–Gas Chromatography-Mass Spectrometry (SPME–GC–MS); (iii) of freeze-dried pulp and peel of New Zealand grown tamarillo. The possible antibacterial activity of freeze-dried tamarillo extracts was also investigated. We show that freeze-drying maintained most of the VCs, with some being more concentrated with the loss of water. The most abundant VC in both fresh and freeze-dried tamarillo was hexanoic acid methyl ester for pulp (30% and 37%, respectively), and (E)-3-Hexen-1-ol for peel (36% and 29%, respectively). With the use of TD–GC–MS, 82 VCs were detected for the first time, when compared to SPME–GC–MS. Methional was the main contributor to the overall aroma in both peel (15.4 ± 4.2 μg/g DW) and pulp (118 ± 8.1 μg/g DW). Compared to water as the control, tamarillo extracts prepared by water and methanol extraction showed significant antibacterial activity against E. coli, P. aeruginosa, and S. aureus with zone of inhibition of at least 13.5 mm. These results suggest that freeze-dried tamarillo has a potential for use as a natural preservative to enhance aroma and shelf life of food products.
40
Moreno-Olivares, Juan, Maria Giménez-Bañón, Diego Paladines-Quezada, Jose Gómez-Martínez, Ana Cebrián-Pérez, Jose Fernández-Fernández, Juan Bleda-Sánchez e Rocio Gil-Muñoz. "Aromatic Characterization of New White Wine Varieties Made from Monastrell Grapes Grown in South-Eastern Spain". Molecules 25, n. 17 (27 agosto 2020): 3917. http://dx.doi.org/10.3390/molecules25173917.
Testo completoAbstract (sommario):
The aromatic profile of a wine is one of the main characteristics appreciated by consumers. Due to climate change, vineyards need to adapt to new conditions, and one of the strategies that might be followed is to develop new white varieties from Monastrell and other cultivars by means of intervarietal crosses, since white varieties are a minority in south-eastern Spain. Such crosses have already been obtained and have been seen to provide quality white wines of high acidity and with a good aromatic composition. To confirm this, a quantitative analysis was carried out during two vintages (2018 and 2019) in order to study and compare the volatile composition of Verdejo (V) wine with the aromatic composition of several wines made from different crosses between Cabernet Sauvignon (C), Syrah (S), Tempranillo (T), and Verdejo (V) with Monastrell (M), by means of headspace SPME-GC-MS analysis. Wine volatile compounds (alcohols, volatile acids, ethyl esters, terpenes, norisoprenoids, and two other compounds belonging to a miscellaneous group) were identified and quantified using a HS-SPME-GS-MS methodology. An additional sensory analysis was carried out by a qualified tasting panel in order to characterize the different wines. The results highlighted how the crosses MT103, MC69, and MC180 showed significant differences from and better quality than the Verdejo wine. These crosses produced higher concentrations of several aromatic families analyzed, which was supported by the views of the tasting panel, thus confirming their excellent aromatic potential as cultivars for producing grapes well adapted to this area for making white wines.
41
Chua, Lee Suan, e Nurul Syafiqah Abd Wahab. "Drying Kinetic of Jaboticaba Berries and Natural Fermentation for Anthocyanin-Rich Fruit Vinegar". Foods 12, n. 1 (23 dicembre 2022): 65. http://dx.doi.org/10.3390/foods12010065.
Testo completoAbstract (sommario):
This study aimed to determine the drying kinetic of jaboticaba berries that were then used for the fermentation of natural fruit vinegar. The drying behavior was fitted well to the thin-layer kinetic model of Midilli et al. in a vacuum oven at 40 °C. Moisture diffusion was the dominant mechanism because two falling rate periods were observed. The effective moisture diffusivity was decreased (2.52 × 10−10 m2/s) after being pretreated with 70% sugar (1.84 × 10−10 m2/s) and 10% salt (6.73 × 10−11 m2/s) solutions. Fresh berry vinegar was found to have higher flavonoids, including anthocyanins, to exhibit higher antiradical and anti-pathogenic microorganism activities. However, the phenolic content in dried berries vinegar was higher, mainly from the bond breaking of tannins and lignins from fruit peel. Some extent of oxidation occurred because of the change in the color index of vinegar samples. The acidity of both vinegars was 3% acetic acid. Headspace GC-MS also detected acetic acid as the major compound (>60%) in the vapor of vinegar samples. A wide range of non-volatile compounds composed of alkaloids, terpenoids, flavonoids, organic acids, and sugar derivatives was detected by UHPLC-TWIMS-QTOFMS. The peak intensity of anthocyanins was reduced by 28–77% in dried berry vinegar. Therefore, it is better to prepare natural fruit vinegar using fresh berries, preserving anthocyanins for high antioxidant capacity.
42
Günbatan, Tuğba, Betül Demirci, İlhan Gürbüz, Fatih Demircib e Ayşe Mine Gençler Özkanc. "Comparison of Volatiles of Sideritis caesarea Specimens Collected from Different Localities in Turkey". Natural Product Communications 12, n. 10 (ottobre 2017): 1934578X1701201. http://dx.doi.org/10.1177/1934578x1701201029.
Testo completoAbstract (sommario):
Sideritis caesarea H. Duman, Aytaç & Başer of the Lamiaceae is an Anatolian endemic species, and is mainly used as herbal tea and folk medicine. This present study aimed to determine and compare the chemical compositions of the volatile components of S. caesarea specimens collected from different localities in Kayseri province, Turkey: Sariz town (samples A and B), Pınarbaşı-Kaynar (sample C) and Pınarbaşı-Şirvan Mountain (sample D), respectively. Initially, the essential oils of the aerial parts were obtained by hydrodistillation and analysed both by gas chromatography-flame ionization detector (GC-FID), gas chromatography/mass spectrometer (GC/MS), simultaneously. Major volatile components of samples A and D were characterized as hexadecanoic acid (19.7 and 20.5%), caryophyllene oxide (6.7 and 20.2%), β-caryophyllene (6.5 and 12.6%), respectively. In sample B, hexadecanoic acid (14.6%), β-caryophyllene (11.5%) and caryophyllene oxide (8.3%) were detected as the major components. Whereas caryophyllene oxide (13.7%), hexadecanoic acid (8.5%) and spathulenol (6.1%) were the main components of the essential oil of sample C. Besides the chemical profiling, in vitro antimicrobial effects of samples were evaluated against a panel of six pathogenic microorganisms. Inhibition zones of the tested samples varied against bacteria with low to moderate activity, where no susceptibility against Candida albicans was observed.
43
Beily, María Eugenia, Brian Jonathan Young, Patricia Alina Bres, Nicolás Iván Riera, Wenguo Wang, Diana Elvira Crespo e Dimitrios Komilis. "Relationships among Physicochemical, Microbiological, and Parasitological Parameters, Ecotoxicity, and Biochemical Methane Potential of Pig Slurry". Sustainability 15, n. 4 (9 febbraio 2023): 3172. http://dx.doi.org/10.3390/su15043172.
Testo completoAbstract (sommario):
Background: Pig slurry can negatively impact on the environmental, animal, and human health. Knowing the relationship between the organic and inorganic loads, pathogens, and toxicity allows identifying the main parameters to be removed or treated before final disposal. The aim of this study was to evaluate the relationships between the physicochemical properties, microbiological, and parasitological content, ecotoxicological effects, and biochemical methane potential (BMP) of pig slurries. Methods: Ten pig slurry samples at two production stages were characterized and a BMP test at two substrate/inoculum (S/I) ratios was conducted to compare the methane yields. Results: We found high content of Cu, Zn, quaternary ammonium, pathogenic microorganisms (E. coli and Salmonella), and parasites (Trichuris and Trichostrongylus). Toxicity on lettuce, radish, and Daphnia was observed with a slurry concentration greater than 1.35%. Positive correlations were found between toxicity on Daphnia and chemical oxygen demand (COD), sulfate, Zn, and Cu, as well as between phytotoxicity and COD, NH4, Na, K, and conductivity. The lowest S/I ratio showed 13% more methane yield. It was associated with high removals of COD and volatile fatty acids. Conclusions: We recommend using a low S/I ratio to treat pig slurry as it improves the efficiency of the anaerobic process.
44
Imeokparia, E. G. "Geochemical evolution of the Jarawa Younger Granite complex and its related mineralization, northern Nigeria". Geological Magazine 122, n. 2 (marzo 1985): 163–73. http://dx.doi.org/10.1017/s0016756800031071.
Testo completoAbstract (sommario):
AbstractThe Jarawa Younger Granite complex is composed of high silica alkali granites that were emplaced 161 Ma ago. The granites are characterized by high contents of Rb, Li, F, Sn, Nb, W above normal low-Ca granitic rocks and have typical S-type characteristics that are indicative of a substantial component of crustal melt.Mineralization in the complex is associated with the biotite granite which was emplaced as a sheet-like body at relatively shallow depth and occurs as disseminations and as greisen lodes and veins.Chemical studies of the granites have shown that the biotite granite represents a highly fractionated rock that crystallized from a residual magma from which the hornblende-biotite granite had previously crystallized. However the biotite granite is characterized by steep gradients in some minor and trace elements that apparently indicate that liquid-state differentiation and/or volatile complexing processes made significant contributions to their differentiation. Enrichment of Th, Li, Rb, Sn, W and Nb may be more closely linked to roofward migration of F.
45
Kang, Hyun Gu, Yanfang Chen, Yoojin Park, Thomas Berkemeier e Hwajin Kim. "Volatile oxidation products and secondary organosiloxane aerosol from D5 + OH at varying OH exposures". Atmospheric Chemistry and Physics 23, n. 22 (20 novembre 2023): 14307–23. http://dx.doi.org/10.5194/acp-23-14307-2023.
Testo completoAbstract (sommario):
Abstract. Siloxanes are composed of silicon, oxygen, and alkyl groups and are emitted from consumer chemicals. Despite being entirely anthropogenic, siloxanes are being detected in remote regions and are ubiquitous in indoor and urban environments. Decamethylcyclopentasiloxane (D5) is one of the most common cyclic congeners, and smog chamber and oxidation flow reactor (OFR) experiments have found D5 + OH to form secondary organosiloxane aerosol (SOSiA). However, there is uncertainty about the reaction products and the reported SOSiA mass yields (YSOSiA) appear inconsistent. To quantify small volatile oxidation products (VOPs) and to consolidate the YSOSiA in the literature, we performed experiments using a potential aerosol mass OFR while varying D5 concentration, humidity, and OH exposure (OHexp). We use a proton transfer reaction time-of-flight mass spectrometer to quantify D5, HCHO, and HCOOH and to detect other VOPs, which we tentatively identify as siloxanols and siloxanyl formates. We determine molar yields of HCHO and HCOOH between 52 %–211 % and 45 %–127 %, respectively. With particle size distributions measured with a scanning mobility particle sizer, we find YSOSiA to be < 10 % at OHexp < 1.3 × 1011 s cm−3 and ∼ 20 % at OHexp, corresponding to that of the lifetime of D5 at atmospheric OH concentrations. We also find that YSOSiA is dependent on both organic aerosol mass loading and OHexp. We use a kinetic box model of SOSiA formation and oxidative aging to explain the YSOSiA values found in this study and the literature. The model uses a volatility basis set (VBS) of the primary oxidation products as well as an aging rate coefficient in the gas phase, kage,gas, of 2.2×10-12 cm3 s−1 and an effective aging rate coefficient in the particle phase, kage,particle, of 2.0 × 10−12 cm3 s−1. The combination of a primary VBS and OH-dependent oxidative aging predicts SOSiA formation much better than a standard-VBS parameterization that does not consider aging (root mean square error = 42.6 vs. 96.5). In the model, multi-generational aging of SOSiA products occurred predominantly in the particle phase. The need for an aging-dependent parameterization to accurately model SOSiA formation shows that concepts developed for secondary organic aerosol precursors, which can form low-volatile products at low OHexp, do not necessarily apply to D5 + OH. The resulting yields of HCHO and HCOOH and the parameterization of YSOSiA may be used in larger-scale models to assess the implications of siloxanes for air quality.
46
Novak, Gordon A., Delaney B. Kilgour, Christopher M. Jernigan, Michael P. Vermeuel e Timothy H. Bertram. "Oceanic emissions of dimethyl sulfide and methanethiol and their contribution to sulfur dioxide production in the marine atmosphere". Atmospheric Chemistry and Physics 22, n. 9 (17 maggio 2022): 6309–25. http://dx.doi.org/10.5194/acp-22-6309-2022.
Testo completoAbstract (sommario):
Abstract. Oceanic emissions of dimethyl sulfide (CH3SCH3, DMS) have long been recognized to impact aerosol particle composition and size, the concentration of cloud condensation nuclei (CCN), and Earth's radiation balance. The impact of oceanic emissions of methanethiol (CH3SH, MeSH), which is produced by the same oceanic precursor as DMS, on the volatile sulfur budget of the marine atmosphere is largely unconstrained. Here we present direct flux measurements of MeSH oceanic emissions using the eddy covariance (EC) method with a high-resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToFMS) detector and compare them to simultaneous flux measurements of DMS emissions from a coastal ocean site. Campaign mean mixing ratios of DMS and MeSH were 72 ppt (28–90 ppt interquartile range) and 19.1 ppt (7.6–24.5 ppt interquartile range), respectively. Campaign mean emission fluxes of DMS (FDMS) and MeSH (FMeSH) were 1.13 ppt m s−1 (0.53–1.61 ppt m s−1 interquartile range) and 0.21 ppt m s−1 (0.10–0.31 ppt m s−1 interquartile range), respectively. Linear least squares regression of observed MeSH and DMS flux indicates the emissions are highly correlated with each other (R2=0.65) over the course of the campaign, consistent with a shared oceanic source. The campaign mean DMS to MeSH flux ratio (FDMS:FMeSH) was 5.5 ± 3.0, calculated from the ratio of 304 individual coincident measurements of FDMS and FMeSH. Measured FDMS:FMeSH was weakly correlated (R2=0.15) with ocean chlorophyll concentrations, with FDMS:FMeSH reaching a maximum of 10.8 ± 4.4 during a phytoplankton bloom period. No other volatile sulfur compounds were observed by PTR-ToFMS to have a resolvable emission flux above their flux limit of detection or to have a gas-phase mixing ratio consistently above their limit of detection during the study period, suggesting DMS and MeSH are the dominant volatile organic sulfur compounds emitted from the ocean at this site. The impact of this MeSH emission source on atmospheric budgets of sulfur dioxide (SO2) was evaluated by implementing observed emissions in a coupled ocean–atmosphere chemical box model using a newly compiled MeSH oxidation mechanism. Model results suggest that MeSH emissions lead to afternoon instantaneous SO2 production of 2.5 ppt h−1, which results in a 43 % increase in total SO2 production compared to a case where only DMS emissions are considered and accounts for 30% of the instantaneous SO2 production in the marine boundary layer at the mean measured FDMS and FMeSH. This contribution of MeSH to SO2 production is driven by a higher effective yield of SO2 from MeSH oxidation and the shorter oxidation lifetime of MeSH compared to DMS. This large additional source of marine SO2 has not been previously considered in global models of marine sulfur cycling. The field measurements and modeling results presented here demonstrate that MeSH is an important contributor to volatile sulfur budgets in the marine atmosphere and must be measured along with DMS in order to constrain marine sulfur budgets. This large additional source of marine–reduced sulfur from MeSH will contribute to particle formation and growth and CCN abundance in the marine atmosphere, with subsequent impacts on climate.
47
Lee, Sae-Byuk, e Heui-Dong Park. "Isolation and Investigation of Potential Non-Saccharomyces Yeasts to Improve the Volatile Terpene Compounds in Korean Muscat Bailey A Wine". Microorganisms 8, n. 10 (8 ottobre 2020): 1552. http://dx.doi.org/10.3390/microorganisms8101552.
Testo completoAbstract (sommario):
The Muscat Bailey A (MBA) grape, one of the most prominent grape cultivars in Korea, contains considerable amounts of monoterpene alcohols that have very low odor thresholds and significantly affect the perception of wine aroma. To develop a potential wine starter for Korean MBA wine, nine types of non-Saccharomyces yeasts were isolated from various Korean food materials, including nuruk, Sémillon grapes, persimmons, and Muscat Bailey A grapes, and their physiological, biochemical, and enzymatic properties were investigated and compared to the conventional wine fermentation strain, Saccharomyces cerevisiae W-3. Through API ZYM analysis, Wickerhamomyces anomalus JK04, Hanseniaspora vineae S7, Hanseniaspora uvarum S8, Candida railenensis S18, and Metschnikowia pulcherrima S36 were revealed to have β-glucosidase activity. Their activities were quantified by culturing in growth medium composed of different carbon sources: 2% glucose, 1% glucose + 1% cellobiose, and 2% cellobiose. W. anomalus JK04 and M. pulcherrima S36 showed the highest β-glucosidase activities in all growth media; thus, they were selected and utilized for MBA wine fermentation. MBA wines co-fermented with non-Saccharomyces yeasts (W. anomalus JK04 or M. pulcherrima S36) and S. cerevisiae W-3 showed significantly increased levels of linalool, citronellol, and geraniol compared to MBA wine fermented with S. cerevisiae W-3 (control). In a sensory evaluation, the flavor, taste, and overall preference scores of the co-fermented wines were higher than those for the control wine, suggesting that W. anomalus JK04 and M. pulcherrima S36 are favorable wine starters for improving Korean MBA wine quality.
48
M. Munira, Rasidah, N. Zakiah e M. Nasir. "IDENTIFICATION OF CHEMICAL COMPOUNDS AND ANTIBACTERIAL ACTIVITY TEST OF Kirinyuh LEAF EXTRACT (Chromolaena odorata L.) FROM Ie Seum GEOTHERMAL AREA, REGENCY OF ACEH BESAR, INDONESIA". RASAYAN Journal of Chemistry 15, n. 04 (2022): 2852–57. http://dx.doi.org/10.31788/rjc.2022.1548031.
Testo completoAbstract (sommario):
This research aims to identify and compare the chemical components of Chromolaena odorata leaf extract grown in the geothermal and outer areas of the geothermal source site. The antibacterial activity of the plant extracts was also identified. The plant materials were collected from the Ie Seum Geothermal area and Blangkrueng region, approximately 31 km from the geothermal area. All samples were extracted using three different solvents: ethanol, nhexane, and ethyl acetate. A phytochemical test was performed to identify the secondary metabolites, volatile components were identified using GC-MS, and the inhibition zone method was used to assess the antibacterial activity of the extracts against S. aureus. The ethanol extract and ethyl acetate from both areas contained phenolic, flavonoid, and steroid, while the n-hexane extracts from both areas’ steroid groups were identified. In addition, GCMS data revealed that the plant material sample from the geothermal contained more chemical constituents compared to the sample from the geothermal outer area. The extract from geothermal also shows better antibacterial activity against S. aureus, and statistical analysis indicates a significant difference in antibacterial activity among solvents and between the origin of the samples.
49
Zannoni, Nora, Valerie Gros, Roland Sarda Esteve, Cerise Kalogridis, Vincent Michoud, Sebastien Dusanter, Stephane Sauvage, Nadine Locoge, Aurelie Colomb e Bernard Bonsang. "Summertime OH reactivity from a receptor coastal site in the Mediterranean Basin". Atmospheric Chemistry and Physics 17, n. 20 (25 ottobre 2017): 12645–58. http://dx.doi.org/10.5194/acp-17-12645-2017.
Testo completoAbstract (sommario):
Abstract. Total hydroxyl radical (OH) reactivity, the total loss frequency of the hydroxyl radical in ambient air, provides the total loading of OH reactants in air. We measured the total OH reactivity for the first time during summertime at a coastal receptor site located in the western Mediterranean Basin. Measurements were performed at a temporary field site located in the northern cape of Corsica (France), during summer 2013 for the project CARBOSOR (CARBOn within continental pollution plumes: SOurces and Reactivity)–ChArMEx (Chemistry and Aerosols Mediterranean Experiment). Here, we compare the measured total OH reactivity with the OH reactivity calculated from the measured reactive gases. The difference between these two parameters is termed missing OH reactivity, i.e., the fraction of OH reactivity not explained by the measured compounds. The total OH reactivity at the site varied between the instrumental LoD (limit of detection = 3 s−1) to a maximum of 17 ± 6 s−1 (35 % uncertainty) and was 5 ± 4 s−1 (1σ SD – standard deviation) on average. It varied with air temperature exhibiting a diurnal profile comparable to the reactivity calculated from the concentration of the biogenic volatile organic compounds measured at the site. For part of the campaign, 56 % of OH reactivity was unexplained by the measured OH reactants (missing reactivity). We suggest that oxidation products of biogenic gas precursors were among the contributors to missing OH reactivity.
50
Tufariello, Maria, Vittorio Capozzi, Giuseppe Spano, Giovanni Cantele, Pasquale Venerito, Giovanni Mita e Francesco Grieco. "Effect of Co-Inoculation of Candida zemplinina, Saccharomyces cerevisiae and Lactobacillus plantarum for the Industrial Production of Negroamaro Wine in Apulia (Southern Italy)". Microorganisms 8, n. 5 (13 maggio 2020): 726. http://dx.doi.org/10.3390/microorganisms8050726.
Testo completoAbstract (sommario):
The employment of multi-species starter cultures has growing importance in modern winemaking for improving the complexity and wine attributes. The assessment of compatibility for selected species/strains at the industrial-scale is crucial to assure the quality and the safety associated with fermentations. An aspect particularly relevant when the species belong to non-Saccharomyces, Saccharomyces spp. and malolactic bacteria, three categories with different biological characteristics and oenological significance. To the best of our knowledge, the present report is the first study regarding the utilization of a combined starter culture composed of three strains of non-Saccharomyces, Saccharomyces cerevisiae and Lactobacillus plantarum for production of wine at the industrial scale. More in-depth, this work investigated the oenological potential of the autochthonous characterized strains from the Apulian region (Southern Italy), Candida zemplinina (syn. Starmerella bacillaris) 35NC1, S. cerevisiae (NP103), and L. plantarum (LP44), in co-inoculation following a complete scale-up scheme. Microbial dynamics, fermentative profiles and production of volatile secondary compounds were assessed in lab-scale micro-vinification tests and then the performances of the mixed starter formulation were further evaluated by pilot-scale wine production. The above results were finally validated by performing an industrial-scale vinification on 100HL of Negroamaro cultivar grape must. The multi-starter formulation was able to rule the different stages of the fermentation processes effectively, and the different microbial combinations enhanced the organoleptic wine features to different extents. The findings indicated that the simultaneous inoculation of the three species affect the quality and quantity of several volatile compounds, confirming that the complexity of the wine can reflect the complexity of the starter cultures. Moreover, the results underlined that the same mixed culture could differently influence wine quality when tested at the lab-, pilot- and industrial-scale. Finally, we highlighted the significance of employment non-Saccharomyces and L. plantarum, together with S. cerevisiae, autochthonous strains in the design of custom-made starter culture formulation for typical regional wine production with pronounced unique quality.