Segui questo link per vedere altri tipi di pubblicazioni sul tema: Taux GC.
Articoli di riviste sul tema "Taux GC"
Cita una fonte nei formati APA, MLA, Chicago, Harvard e in molti altri stili
Vedi i top-22 articoli di riviste per l'attività di ricerca sul tema "Taux GC".
Accanto a ogni fonte nell'elenco di riferimenti c'è un pulsante "Aggiungi alla bibliografia". Premilo e genereremo automaticamente la citazione bibliografica dell'opera scelta nello stile citazionale di cui hai bisogno: APA, MLA, Harvard, Chicago, Vancouver ecc.
Puoi anche scaricare il testo completo della pubblicazione scientifica nel formato .pdf e leggere online l'abstract (il sommario) dell'opera se è presente nei metadati.
Vedi gli articoli di riviste di molte aree scientifiche e compila una bibliografia corretta.
1
OUAAR, Djilali, Aicha MEGHERBI BENALI, Fawzia TOUMI BENALI, Marie-France THÉVENON, Kévin CANDELIER, Luc PIGNOLET e Jean GÉRARD. "Durabilité naturelle et composition en extractibles du bois de Juniperus oxycedrus subsp. oxycedrus du Nord-Ouest de l’Algérie". BOIS & FORETS DES TROPIQUES 350 (4 gennaio 2022): 57–69. http://dx.doi.org/10.19182/bft2021.350.a36837.
Testo completoAbstract (sommario):
Les bois de Juniperus oxycedrus subsp. oxycedrus étudiés sont issus de deux provenances du Nord-Ouest algérien aux conditions climatiques et édaphiques différentes (régions de Sidi Bel Abbès et de Tiaret). Les extractibles et les polyphénols totaux du duramen ont été quantifiés et caractérisés. La durabilité naturelle du duramen a été évaluée vis-à-vis de deux champignons de pourriture brune (Rhodonia placenta et Coniophora puteana) et de termites (Reticulitermes flavipes). Les taux d’extractibles les plus élevés sont ceux obtenus pour les bois de Sidi Bel Abbès. L’extraction au mélange toluène-éthanol a permis d’obtenir des taux plus élevés que l’extraction à l’eau, respectivement 14,17 % et 1,35 % pour les bois de Sidi Bel Abbès contre 9,84 % et 1,19 % pour ceux de Tiaret. Les analyses par chromatographie en phase gazeuse couplée à la spectrométrie de masse (GC/MS) montrent que les familles chimiques majoritairement identifiées dans les extraits aqueux sont les sesquiterpénoïdes, les acides gras et les stérols. Dans les extraits au toluène-éthanol, les sesquiterpènes et les sesquiterpénoïdes sont les composés majeurs. La composition en sesquiterpènes et sesquiterpénoïdes est différente en fonction de la provenance des bois, mais reste très similaire quantitativement. La teneur en polyphénols totaux des extraits au méthanol de la provenance Sidi Bel Abbès est supérieure à celle de Tiaret. Aucune différence significative n’est observée entre les deux provenances pour la durabilité naturelle vis-à-vis de C. puteana. En revanche, la résistance à R. placenta est significativement plus élevée pour la provenance Sidi Bel Abbès. Pour les deux provenances, le bois de J. oxycedrus subsp. oxycedrus est très durable vis-à-vis des champignons de pourriture. Il est aussi répulsif et résistant aux attaques de termites. Une analyse ciblée des relations entre la composition chimique et la durabilité naturelle permettra de mettre en évidence la nature du ou des constituants responsables de la durabilité́ naturelle du bois de J. oxycedrus subsp. oxycedrus, tant vis-à-vis des champignons lignivores que des termites.
2
Eddine, Laib Djamel, Benzehra Abdelmadjid, Rahmani Youcef, Boulaouad Belkacem Aimene e Akkal Salah. "L’emploi de l’extrait du champignon endophyte Aspergillus niger isolé à partir des feuilles du ricin commun Ricinus communis L. (Euphorbiaceae, Malpighiales) comme agent de lutte biologique contre le criquet migrateur Locusta migratoria L. (Oedipodinae, Acrididae)." Journal of Applied Biosciences 170 (28 febbraio 2022): 17720–38. http://dx.doi.org/10.35759/jabs.170.5.
Testo completoAbstract (sommario):
Objectifs : Évaluer l'activité insecticide de l'extrait du champignon endophyte Aspergillus niger. Méthodologie et Résultats : Pour évaluer l'activité insecticide, dix concentrations (de 0,2 à 2 g/ L) de l'extrait fongique ont été appliqués par contact et par ingestion contre Locusta migratoria L. Pour connaitre la nature des métabolites secondaires responsables de l’activité insecticide des analyses chimiques, infrarouge à réflexion totale atténuée par transformée de Fourier de l'extrait fongique et un GC-MS-MS des hyphes du champignon et de l'extrait fongique ont été effectués. Un test d’inhibition d’Acétyl cholinestérase par l’extrait fongique a été effectué afin de connaitre le mode d’action ou l’effet d’extrait sur le système nerveux des insectes traités. La concentration la plus efficace contre les insectes est de 2 g/L, avec un taux de mortalité maximum de 86,95%et 100% pour les traitements par contact et ingestion, respectivement. L'analyse chimique de l'extrait fongique a révélé la présence de polyphénols, d'alcaloïdes, de terpénoïdes et de saponines comme métabolites responsables de ces activités. L'analyse FTIR-ATR de l'extrait fongique a révélé la présence de groupes alcool, nitro, imine, alcyne et hydroxyle. L'analyse GC-MS des hyphes et de l’extrait fongique a révélé la présence des volatiles insecticides Hexahydro-1H-cyclopenta [c] isoxazole-4, 5,6-triol, 2, 3, 4,4a, 5, 6, 7,8-octahydro-1H -naphtalène-1,8a-diol et acide propanoïque 2-éthyl-3-hydroxyhexyle. A 4 μg/mL l’extrait fongique est doté d’une activité inhibitrice d’Acétylcholinestérase maximale de 73,91 %. Conclusions et application des résultats : l’extrait du champignon endophyte d’Aspergillus niger constitue une bonne source de métabolites secondaires volatiles et non-volatiles à activité insecticide et peut être utilisé comme insecticide de contact ou ingestion contre L. migratoria. 17720 Laib et al., J. Appl. Biosci. Vol : 170, 2022 L’emploi de l’extrait du champignon endophyte Aspergillus niger isolé à partir des feuilles du ricin commun Ricinus communis L. comme agent de lutte biologique contre le criquet migrateur Locusta migratoria L. Mots clés : Activité insecticide, champignons endophytes, Locusta migratoria, Aspergillus niger, GC-MS-MS, FTIR-ATR. ABSTRACT Objectives: Evaluate the insecticidal activity of the extract obtained from the endophytic fungus, Aspergillus niger. Methodology and Results: Ten concentrations of 0.2 to 2 g/L of the fungal extract were applied by contact against Locusta migratoria L. To find out the nature of the secondary metabolites responsible for the insecticidal activity, we carried out chemical analysis, an infrared analysis with total reflection attenuated by transform Fourier of the fungal extract, and GC-MS-MS analysis for both colony and fungal extract. To reveal the effect of the extract on the nervous system of the treated insects, we carried out an acetyl cholinesterase inhibition test. The most effective concentration against the insects was 2 g/L, with a maximum mortality rate of 86, 95%and 100% for L. migratoria upon contact and ingestion treatments, respectively. Chemical analysis of the fungal extract revealed the presence of polyphenols, alkaloids, terpenoids, and andsaponins asthe metabolites responsible for these activities. The FTIR-ATR of the fungal extract revealed the presence of alcohol, nitro, imine, alkyne, and hydroxyl groups. Specifically, GC-MS analysis of both colony and fungal extract revealed the presence of the insecticidal volatiles Hexahydro-1Hcyclopenta [c] isoxazole-4,5,6-triol ,2,3,4,4a, 5,6,7,8-octahydro-1H-naphthalene-1,8a-diol and Propanoic acid 2-ethyl-3-hydroxyhexyl.Moreover, we found that at a concentration of 4 μg/mL, the fungal extract had a maximum inhibitory capacity of Ache of 73.11%. Conclusions and application of findings: the endophytic fungus A. niger is a good source of volatile and non-volatile secondary metabolites with insecticidal activity against L. migratoria. Keywords: Insecticidal activity, endophytic fungi, Locusta migratoria, Aspergillus niger, GCMS-MS, FTIR-ATR.
3
Awaludin, Zaenal, Masatoshi Suzuki, Jahangir Masud, Takeyoshi Okajima e Takeo Ohsaka. "Enhanced Electrocatalysis of Oxygen Reduction on Pt/TaOx/GC". Journal of Physical Chemistry C 115, n. 51 (6 dicembre 2011): 25557–67. http://dx.doi.org/10.1021/jp209347r.
Testo completo
4
Sidhu, A., A. Bharadwaj e A. Nandagudi. "AB0529 TEMPORAL ARTERY ULTRASOUND (TAUS) IS A RELIABLE TECHNIQUE TO RULE OUT GCA EVEN IN THE LEARNING PHASE". Annals of the Rheumatic Diseases 79, Suppl 1 (giugno 2020): 1562.3–1562. http://dx.doi.org/10.1136/annrheumdis-2020-eular.6540.
Testo completoAbstract (sommario):
Background:Giant cell arteritis (GCA) is an emergency. The initial treatment with high dose glucocorticoids (GC) is often started on clinical suspicion without waiting for Temporal artery biopsy (TAB) results, which can take days to be available. TAUS is a simple, non-invasive test which is readily available. However, like any other ultrasound, it is also operator dependent. A positive halo sign is the most specific abnormality seen on TAUS in GCA patients. The percentage of false positive TAUS in GCA diagnosis is low (1), but it can result in over diagnosis and unnecessary exposure to high dose GC in elderly population.Objectives:We looked at the reliability of TAUS in ruling out GCA after it was introduced within our rheumatology department one year ago.Methods:We adopted the quality improvement methodology for assessment. Retrospective data of suspected GCA patients was collected over the last two years. TAUS was introduced regularly to the investigative plan after eleven months. Two Rheumatology consultants were trained in TAUS. Results were compared before and after the introduction of ultrasound as a diagnostic tool. In collecting the data, our main focus for documentation was based on clinical symptoms, TAUS and TAB results. We aimed to increase the awareness of appropriate GCA referrals among the primary and secondary care with the support of teaching sessions.Results:From January 2018 to November 2019, 101 patients were referred to rheumatology with suspected GCA. Median age of our cohort was 72 years with male to female ratio of 1:3. 35 patients were referred in the first 11 months out of which, 10 (28.6%) were diagnosed with GCA. TAUS and TAB was done in 20% and 49% of patients respectively. 66 patients were referred in the next 12 months after TAUS was introduced. Out of 66, 14 patients (21.2%) were diagnosed as GCA. TAUS and TAB were done in 82% and 38% of the patients respectively. As listed in table 1, only 1 patient was found to have positive TAB after a negative TAUS (false negative). All of patients with positive TAUS were treated as GCA on the basis of clinical grounds, irrespective of TAB results. Despite the regular use of TAUS as a diagnostic tool in the second phase, there is a higher percentage of patients (78.8%) in which GCA was ruled out.TAUS introductionBefore regular TAUS(Jan 2018 – Nov 2018)After regular TAUS(Dec 2018 – Nov 2019)Patients referred3566GCA10 (28.6%)14 (21.2%)Not GCA25 (71.4%)52 (78.8%)TAUS done in20%82%TAB done in49%38%TAUS -ve and TAB +ve01TAUS +ve and TAB -ve/not done28Conclusion:After the routine introduction of TAUS, the percentage of patients diagnosed with GCA has declined and clinicians have been able to exclude suspected GCA diagnosis in a larger proportion of patients referred. This is noteworthy as our Rheumatologists are still in the learning phases of determining the significance of utility of TAUS. There is only a small decline in TAB frequency, which is expected to go down further in the coming years. We also noticed that the number of patients referred has almost doubled. This might be due to better education and awareness at the primary and secondary care level which was done as part of the project.References:[1]Fernández E, Monjo I, Bonilla G, et alOP0210 FALSE POSITIVES OF ULTRASOUND IN GIANT CELL ARTERITIS. SOME DISEASES CAN ALSO HAVE HALO SIGNAnnals of the Rheumatic Diseases2019;78:181Disclosure of Interests:None declared
5
Wilson, Karen L. "Report of the General Committee: 26". TAXON 72, n. 4 (agosto 2023): 905–7. http://dx.doi.org/10.1002/tax.12994.
Testo completoAbstract (sommario):
SummaryDecisions of the General Committee are reported on about half of the proposals and requests in Report 73 of the Permanent Nomenclature Committee for Vascular Plants and Report 16 of the Permanent Nomenclature Committee for Fossils. As specified by the Code, the GC was consulted by the NC Fungi on several matters relating only to fungi.
6
Thompson, M. G., R. M. Palmer, A. Thom, K. Garden, G. E. Lobley e G. Calder. "N tau-methylhistidine turnover in skeletal muscle cells measured by GC-MS". American Journal of Physiology-Cell Physiology 270, n. 6 (1 giugno 1996): C1875—C1879. http://dx.doi.org/10.1152/ajpcell.1996.270.6.c1875.
Testo completoAbstract (sommario):
A method that employs gas chromatography-mass spectrometry has been developed to measure N tau-methylhistidine (3-methylhistidine; 3-MH) synthesis and release from skeletal muscle myotubes in vitro. It shows excellent linearity (0.9999) over the range studied (0-4 nmol), high recovery (92.6%), and low coefficient of variation (1.6%). 3-MH release from myotubes was essentially linear over a 96-h incubation, whereas the loss of 3-MH from cell protein accelerated with increasing time, an effect due, at lest in part, to decreasing rates of total protein synthesis. When incubated in either glutamine-free or methionine-free medium for 48 h, 3-MH in cell protein and appearing in the medium were greatly reduced compared with the 48-h controls, suggesting that hypertrophy was greatly reduced. Similar but lesser trends were observed with adenosine 3',5' -cyclic monophosphate. In contrast, 12-O-tetradecanoylphorbol-13-acetate (TPA) appeared to both stimulate 3-MII synthesis and inhibit its release during a 48-h incubation. The development of this method facilitates detailed investigation into the mechanisms through which agents such as TPA regulate myofibrillar protein degradation.
7
Silva, Bruno B., Pedro L. Rosalen, Jaime A. Cury, Masaharu Ikegaki, Vinícius C. Souza, Alessandro Esteves e Severino M. Alencar. "Chemical Composition and Botanical Origin of Red Propolis, a New Type of Brazilian Propolis". Evidence-Based Complementary and Alternative Medicine 5, n. 3 (2008): 313–16. http://dx.doi.org/10.1093/ecam/nem059.
Testo completoAbstract (sommario):
Red propolis is a new type of Brazilian propolis. This material, as well as the secretions of 20 plant species that are often mentioned as its probable botanical source, have been investigated by RP-HPTLC. Phytochemical evidence based on UV-VIS spectra, RP-HPLC and GC-MS, showedDalbergia ecastophyllum(L.) Taub. to be the main source of red propolis in Alagoas state. The propolis and plant resin showed high relative percentages of the isoflavonoids 3-Hydroxy-8,9-dimethoxypterocarpan and medicarpin. To our knowledge this is the first report of the secretion of a leguminous species being the source of propolis.
8
Tyutkova, Ekaterina Aleksandrovna, Sergey Radzhinaldovich Loskutov e Daniil Vyacheslavovich Dorzhiev. "SEASONAL CHEMICAL STRUCTURE VARIABILITY IN BETULA TORTUOSA LEDEB. TREE RINGS IN ALPINE FOREST-TUNDRA OF KUZNETSK ALA TAU MOUNTAINS". chemistry of plant raw material, n. 3 (2 ottobre 2023): 63–70. http://dx.doi.org/10.14258/jcprm.20230311761.
Testo completoAbstract (sommario):
Woody vegetation growth conditions have marked effects on hemicellulose, cellulose and lignin formation. In this study, we analyzed the climatic responses of these major cell wall polymers in Betula tortuosa. We studied 35 annual rings (1980–2015) of Betula Tortuosa Ledeb. trees growing in the alpine forest-tundra of Kuznetsk Ala Tau using and pyrolysis gas chromatography mass spectrometry (Py-GC/MS). Our analysis of the correlation of the resulting spectra and Py-GC/MS values with mean air temperature and precipitation showed that the polymeric composition of Betula Tortuosa Ledeb. was mainly determined by June-August climate. The major factor limiting the development of the “unique” cell wall polymer composition of Betula Tortuosa Ledeb. found in alpine forest-tundra of Kuznetsk Ala Tau was a deficit of heat. At the end of the growing season, precipitation had largely a negative impact on polymer formation in Betula Tortuosa Ledeb. cell walls. We believe that Py-GC/MS is an effective approach to quantifying the consequences of current climate trends for Siberian forest ecosystems.
9
Firdaus, Aulia Anisa, Endhah Purwandari, Retno Asih, Ahmad Sholih e Darminto Darminto. "The Optical Energy Gap of the Semiconducting Intrinsic Layer for Organic Solar Cell Applications". Computational And Experimental Research In Materials And Renewable Energy 6, n. 1 (31 maggio 2023): 14. http://dx.doi.org/10.19184/cerimre.v6i1.39254.
Testo completoAbstract (sommario):
The optical energy gap of the semiconducting intrinsic layer plays a crucial role in determining the increase in efficiency. The carbon-based biomass can be a choice for the silicon used as solar cell material. Here, we proposed the best biomass that can be used as a semiconductor component in solar cell applications. Coconut shells as bio-waste and palmyra sap, which are available in most areas of Indonesia, can be the best candidates to be considered. The XRD measurement showed both organic materials have an amorphous phase. The coconut shells sample has two peaks that are identical to graphene peaks, therefore this material is called graphenic-like carbon (GC). Furthermore, from the UV-visible spectroscopy, it was shown that both materials have a high transmittance of more than 95%, which indicates that they have transparent properties. Also, the Tauc plot method gives information about the optical energy gap of coconut shell charcoal (GC) and palmyra sap (a:C) which are 2.67 and 1.83 eV, respectively. From this result, palmyra sap becomes promising material to be applied as an intrinsic layer for semiconducting components in solar cell applications.Keywords: Amorphous phase, Coconut shells charcoal, Optical energy gap, Palmyra sugar.
10
Ambastha, Surabhi, Amit Patnaik, Vinay Oraon e Latika Sharan. "Antimicrobial activity and GCMS Analysis of leaves Extracts of Butea Monosperma Lam Taub". Defence Life Science Journal 8, n. 3 (29 maggio 2023): 217–28. http://dx.doi.org/10.14429/dlsj.8.18789.
Testo completoAbstract (sommario):
Butea monosperma (Lam.) Taub is a well-known medicinal plant belonging to the family Fabaceae. More than hundreds of plants have been reported in the Ethno-botanical literature of India for theiranti-microbial activity as well as for treatment of many diseases and Butea monosperma (Lam.)Taub is one of them. The present investigation is focused on the anti-microbial activity of Butea monosperma leaves against both gram-positive (Bacillus subtilis, Enterococcus faecalis, Lactobacillus acidophilus, Staphylococcus aureus and Streptococcus mutans) and gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa) as well as fungi (Candida albicans and Trichophyton rubrum). Both excerpts (ethanol and methanol) show positive responses against all the selected microorganisms. GC-MS analysis is done to find out important compound which is anti-microbial. A total of 38 compounds are identified in GC-MS analysis. Out of 38 compounds, 8 compounds are identified as antimicrobial in nature such as Dodecane, 2-HEXADECEN-1-OL, 3,7,11,15-TETRAMETHYL-, [R-[, Hexadecanoic acid, methyl ester, Phytol, Palmidrol, Squalene, Tetracosane, Vitamin E and Lup-20(29)-en-3-one which justify, this plant possess significant anti-microbial property. GC-MS analysis reveals that majorly, this plant leaves also possess 10 antioxidant compounds (Neophytadiene, 2-HEXADECEN-1-OL, 3,7,11,15-TETRAMETHYL-, [R-[, n-Hexadecanoic acid, Phytol, squalene, .alpha.-Tocospiro B, Tetracosane, .gamma.-Tocopherol, Ergost-5-en-3-ol, (3.beta.)- and STIGMASTA-5,22-DIEN-3-OL, (3.BETA.,22E)-,), 9 anti-cancerous compounds (Hexadecanoic acid, methyl ester, 9,12,15-OCTADECATRIENOIC ACID, METHYL ESTER, squalene, .gamma.-Tocopherol, Vitamin E, Ergost-5-en-3-ol, (3.beta.)-, STIGMASTA- 5,22-DIEN-3-OL, (3.BETA.,22E)-, .gamma.-Sitosterol and Lupeol),8 anti-inflammatory compounds (Neophytadiene,2-HEXADECEN-1-OL, 3,7,11,15-TETRAMETHYL-, [R-[, Hexadecanoic acid, methyl ester, n-Hexadecanoic acid, 9,12,15-OCTADECATRIENOIC ACID, METHYL ESTER, Phytol, Palmidrol, .alpha.-Tocospiro B and Lupeol), 3 cardioprotective compounds ( Neophytadiene, .alpha.-Tocospiro B and .gamma.-Tocopherol A) and 5 antidiabetic compounds (.alpha.-Tocospiro B, Vitamin E, STIGMASTA-5,22-DIEN-3-OL, (3.BETA.,22E)-, .gamma.-Sitosterol and Lup-20(29)-en-3-one).This investigation suggests that this plant leaf has not only anti-microbial potential but also possesses other important compounds to fight against many deadly diseases. Thus, this plant has immense potential to make an individual place in pharmacological industries, especially as antibiotics.
11
Ngassoum, Martin, Leopold Jirovetz e Gerhard Buchbauer. "SPME/GC/MS analysis of headspace aroma compounds of the Cameroonian fruit Tetrapleura tetraptera (Thonn.) Taub." European Food Research and Technology 213, n. 1 (1 luglio 2001): 18–21. http://dx.doi.org/10.1007/s002170100330.
Testo completo
12
Ambastha, Surabhi, e Latika Sharan. "Review on Medicinal Importance of Butea monosperma Lam. (Taub)". Defence Life Science Journal 8, n. 1 (10 marzo 2023): 83–92. http://dx.doi.org/10.14429/dlsj.8.18536.
Testo completoAbstract (sommario):
Butea monosperma is a renowned therapeutic plant, a medium size deciduous tree broadly dispersed in India, Bangladesh, Cambodia, Myanmar, China South-Central, Nepal, Laos, Sri Lanka, China Southeast, Pakistan, and Vietnam. Butea monosperma is being used in customary medication preparation from the pre historic period. It is acknowledged as the forest’s flame and is often branded as Dhak or Palash. It is described in Upanishads, Susruta Samhita, Vedas, Ashtanga Sangraha, Astanga Hridaya, and Charka Samhita. It belongs to the family of Fabaceae, which has an extensive range of vigorous principles, and it has phytoconstituents such as glycosides, flavonoids, etc.This revisional analysis is focused on the pharmacological actions, mainly shown by seeds, flowers, fruits, barks,leaves, etc., like anti-diabetic, anthelmintic, hepatoprotective, anti-stress, anti-implantation, anti-convulsant, wound healing, giardiasis, anti-oxidant, anti-dopaminergic, anti-microbial, sunscreen, anti-diarrheal, free radical scavenging, anti-filarial, anti-fungal, nephroprotective, protease inhibitor, osteogenic, hemagglutinating, anti-ulcer, giardiasis, anti-asthmatic, anti-inflammatory, anti-fertility and anti-cancer activity. GC-MS analysis of Butea monospermashows the attendance of important compounds which is volatile and HPLC analysis for non-volatile, which supplies light to its medicinal properties. These therapeutic chattels may provide impending active principles with advanced usefulness and the leastafter-effects as equated to accessible artificial drugs.
13
Teplyakova, S. B., A. L. Shavarda, T. V. Shelenga, E. A. Dzyubenko e E. K. Potokina. "A simple and efficient method to extract polar metabolites from guar leaves (Cyamopsis tetragonoloba (L.) Taub.) for GC-MS metabolome analysis". Vavilov Journal of Genetics and Breeding 23, n. 1 (26 febbraio 2019): 49–54. http://dx.doi.org/10.18699/vj19.460.
Testo completoAbstract (sommario):
Guar (Cyamopsis tetragonoloba (L.) Taub.) is an agricultural crop species new to Russia and is in demand by the gas, oil and food industries. Due to the progress of “omics” technologies and the marker-assisted selection, there is a huge interest in the studies that compare the metabolites of various guar varieties, employing metabolomics as a method of functional genomics. For a large-scale screening of guar germplasm from the VIR collection, it is important to choose an efficient method to extract metabolites from samples. The accuracy of the assessment of the content of metabolites in samples is crucial for distinguishing varieties within the crop, since the metabolome profiles of plants within the same species differ mainly in the quantitative ratio of metabolites, and not in their qualitative composition. In metabolome practice, two methods of extracting polar compounds are usually employed in the preparation of samples for GC-MS analysis. One of the widely used methods of sample preparation is the long-term extraction of metabolites from whole tissues with the aid of a methanol solvent. Another method of sample preparation is based on the short-term methanol extraction of metabolites from frozen and homogenized material. The advantages and disadvantages of these two methods revealed in the course of our work have prompted us to develop a new approach that avoids some difficulties in analyzing the metabolic profiles of leaves of various guar varieties. The method we suggested combines the advantages of the two above-mentioned approaches of sample preparation, namely eliminates the loss of metabolites due to centrifugation and ensures the complete destruction of all cell walls, ensuring the maximum extraction level of polar metabolites. The essence of the new method is that the leaf is rapidly frozen in liquid nitrogen with subsequent thawing in cold methanol. Thus, leaf tissues retain morphological integrity, and subsequent centrifugation, necessary for homogenization, is skipped. We have checked the effectiveness of this improved method by experiments with leaf samples of three guar genotypes. It has been shown that the amount of extracted metabolites increases more than 5-fold compared to extraction with methanol from fresh unfrozen leaf tissues and more than 2-fold compared to extraction with methanol after freezing and homogenization. Extraction of metabolites using the new method allows the GC-MS analysis of guar samples to be conducted with the least loss and high accuracy required to distinguish varieties.
14
Kilonzo, Mhuji, Chrispinus Rubanza, Upendo Richard e Gideon Sangiwa. "Antimicrobial activities and phytochemical analysis of extracts from Ormocarpum trichocarpum (Taub.) and Euclea divinorum (Hiern) used as traditional medicine in Tanzania". Tanzania Journal of Health Research 21, n. 2 (10 settembre 2020): 1–12. http://dx.doi.org/10.4314/thrb.v21i2.6.
Testo completoAbstract (sommario):
Background: Medicinal plants have been of great value to human healthcare in most parts of the world for thousands of years. In Tanzania, over 12,000 species of higher plants have been reported, and about 10% are estimated to be used as medicines to treat different human health conditions. The present study aimed to determine in vitro antimicrobial activities and phytochemical analysis of Ormocarpum trichocarpum and Euclea divinorum which are commonly used as a traditional medicine in Tanzania.
Methods: Minimum Inhibitory Concentration (MIC) of plants extracts against tested bacterial and fungal species were determined using 96 wells microdilution method. In this method, 50 μL of nutrient and saboraud’s dextrose broth for bacteria and fungus respectively were loaded in each well followed by 50 μL of extract to make final volume of 100 μL. Subsequently 50 μL were transferred from first rows of each well to the second rows and the process was repeated down the columns to the last wells from which 50 μL were discarded. Thereafter, 50 μL of the selected bacterial and fungal suspension was added to each well thus making final volume of 100μL. The lowest concentration which showed no microbe growth was considered as MIC. The study also evaluated phytochemical compounds present in the ethyl acetate extracts from O. trichocarpum stem bark and E. divinorum root bark extract using Gas Chromatography-Mass Spectrometry (GC-MS) technique.
Results: It was revealed that 66% of the tested microbes were susceptible to plant extracts at MIC value of 0.39 mg/mL whereas 83% being susceptible to extracts at MIC value of 0.781 mg/mL. Interestingly, four out of 18 tested plant extracts exhibited high antifungal activity below that of the standard antifungal drug, fluconazole. The GC-MS analysis revealed the presence of various low molecular weight phytochemicals which belongs to six groups of secondary metabolites namely dieterpenes, alphatic hydrocarbons, tetraterpenes, sesquiterpenes, steroid and triterpenes.
Conclusion: It was concluded that the presence of various phytochemicals in the tested plant extracts may be associated with pharmacological properties of O. trichocarpum and E. divinorum and therefore justifying ethnomedical usage of such plants.
Keywords: Antibacterial, antifungal, Ormocarpum trichocarpum, Euclea divinorum
15
Grigoreva, Elizaveta, Alexander Tkachenko, Serafima Arkhimandritova, Aleksandar Beatovic, Pavel Ulianich, Vladimir Volkov, Dmitry Karzhaev, Cécile Ben, Laurent Gentzbittel e Elena Potokina. "Identification of Key Metabolic Pathways and Biomarkers Underlying Flowering Time of Guar (Cyamopsis tetragonoloba (L.) Taub.) via Integrated Transcriptome-Metabolome Analysis". Genes 12, n. 7 (22 giugno 2021): 952. http://dx.doi.org/10.3390/genes12070952.
Testo completoAbstract (sommario):
Guar (Cyamopsis tetragonoloba (L.) Taub.) is an annual legume crop native to India and Pakistan. Seeds of the plant serve as a source of galactomannan polysaccharide (guar gum) used in the food industry as a stabilizer (E412) and as a gelling agent in oil and gas fracturing fluids. There were several attempts to introduce this crop to countries of more northern latitudes. However, guar is a plant of a short photoperiod, therefore, its introduction, for example, to Russia is complicated by a long day length during the growing season. Breeding of new guar varieties insensitive to photoperiod slowed down due to the lack of information on functional molecular markers, which, in turn, requires information on guar genome. Modern breeding strategies, e.g., genomic predictions, benefit from integration of multi-omics approaches such as transcriptome, proteome and metabolome assays. Here we present an attempt to use transcriptome-metabolome integration to understand the genetic determination of flowering time variation among guar plants that differ in their photoperiod sensitivity. This study was performed on nine early- and six delayed-flowering guar varieties with the goal to find a connection between 63 metabolites and 1,067 differentially expressed transcripts using Shiny GAM approach. For the key biomarker of flowering in guar myo-inositol we also evaluated the KEGG biochemical pathway maps available for Arabidopsis thaliana. We found that the phosphatidylinositol signaling pathway is initiated in guar plants that are ready for flowering through the activation of the phospholipase C (PLC) gene, resulting in an exponential increase in the amount of myo-inositol in its free form observed on GC-MS chromatograms. The signaling pathway is performed by suppression of myo-inositol phosphate kinases (phosphorylation) and alternative overexpression of phosphatases (dephosphorylation). Our study suggests that metabolome and transcriptome information taken together, provide valuable information about biomarkers that can be used as a tool for marker-assisted breeding, metabolomics and functional genomics of this important legume crop.
16
Hoa, Kiều Thị Quỳnh, Nguyễn Thị Yên e Đặng Thị Yến. "Optimization of biosurfactant production for enhanced crude-oil degradation by a Candida tropicalis 1214-BK14 isolated from white tiger oilfiel - Vung Tau, Vietnam". Vietnam Journal of Biotechnology 15, n. 1 (20 aprile 2018): 189–96. http://dx.doi.org/10.15625/1811-4989/15/1/12334.
Testo completoAbstract (sommario):
Biosurfactants are amphiphilic molecules with effective surface-active and biological properties applicable to replace synthetic surfactant in petroleum industry. Interest in microbial surfactants has been steadily increasing in recent years, as they have numerous advantages compared to chemical surfactants including a lower toxicity, better environmental compatibility and effective properties at extreme temperature, pH levels and salinity. A crude oil-degrading yeast strain (C. 1214-BK14) was selected among the isolated strains as a potential biosurfactant-producer from producing oil wells at White Tiger oilfield because of its ability to produce biosurfactant using crude oil as a sole carbon source. An emulsification index (E24%) of 57% was obtained initially by Candida tropicalis 1214-BK14 in previous study. Therefore, the optimization of biosurfactant production of this strain for enhanced crude oil degradation was carried out based on central composite design and analyzed using response surface methodology (RSM). The biosurfactant production process was investigated as function of three independent variables: crude oil (2.5-5 % w/v), (NH4)2SO4 (0.35-0.45% w/v), and solution pH (5-8). RSM analysis showed that the optimum condition for the biosurfactant production by C. tropicalis 1214-BK14 were 6.1, 3.97% (w/v) and 0.37% (w/v) for pH, concentration of carbon (crude oil) and nitrogen substrate ((NH4)2SO4), respectively, with the emulsification index measured in the conditions was 80.2%. The total crude oil and C10-C43 alkanes degradation efficiency by this strain estimated using GC/MS were 89.8% and 80.47-98.58%, respectively. These results revealed that the strain Candida tropicalis 1214-BK14 exhibited a tremendous potential for contaminated-crude oil degradation and microbial enhanced oil recovery (MEOR).
17
Jia, Pingfan, Xiaoyu Zhang, Bo Wang e Qinge Ji. "Evaluation of the Attractant Effect of Solanum muricatum (Solanales: Solanaceae) on Gravid Female Adults of Zeugodacus tau (Diptera: Tephritidae) and Screening of Attractant Volatiles". Insects 14, n. 7 (30 giugno 2023): 591. http://dx.doi.org/10.3390/insects14070591.
Testo completoAbstract (sommario):
Zeugodacus tau (Walker) (Diptera: Tephritidae) is a pest seriously harmful to Solanaceae crops and was found to oviposit on the pepino melon Solanum muricatum (Aiton). To date, the differences in the ability of the fruits of S. muricatum and other Solanaceae crops to attract gravid Z. tau females have seldom been reported. Oviposition and trapping bioassays were performed to clarify whether such differences existed. A combination of GC-MS and the Y-tube olfactometer system was used to identify and determine the compounds inducing behavioral responses in gravid Z. tau females to the volatile odors of S. muricatum. The results show that S. muricatum odors play a role in attracting gravid Z. tau females. The odors of Solanaceae crops influence their ability to attract these organisms. The nine compounds from the volatiles of S. muricatum induce tendency or repellency responses in gravid Z. tau females. Hexyl acetate, butyl acetate, amyl actate, and isoamyl acetate caused tendency behavior in gravid Z. tau females, while hexyl hexanoate, butyl isovalerate, butyl valerate, and isoamyl hexanoate caused repellency behavior. Heptyl acetate caused repellency behavior in gravid Z. tau females at higher concentrations (5 mg/mL) but caused tendency behavior at a low concentration (0.5 mg/mL). These results suggest that vigilance against the harm caused by Z. tau is required during the cultivation of S. muricatum. The nine compounds of the volatile odors of S. muricatum could help to develop attractants and repellents for gravid Z. tau females. These results are beneficial for preventing Z. tau females from harming S. muricatum, developing attractants and repellents for Z. tau females, and establishing a system of ecological control for Z. tau females.
18
Dai, Rahmawaty A., Ventje Ilat e Lidia Mawikere. "ANALISIS PERHITUNGAN DAN PEMOTONGAN PPH PASAL 21 PADA KARYAWAN TETAP PT. MEGA JASAKELOLA MANADO". GOING CONCERN : JURNAL RISET AKUNTANSI 14, n. 1 (31 dicembre 2018). http://dx.doi.org/10.32400/gc.13.04.21180.2018.
Testo completoAbstract (sommario):
In accorrdance withh the Laaw no. 36 Year 2008, everyone should calculate the tax. Currently not a few companies that cut taxes that are not in accordance with applicable regulations. This is due to the company budgeted as a cost. The company will need a fee for profit. Therefore for the sake of smooth calculation and tax cuts required a god cooperatiion bettween the goverrnment anhd thee companny government. PT. Mega Jasakelola Manado is engaged in Security services (security), Cleaning Services (cleaning service) in Manado city especially in megamas area Manado, has provided security for the visitors mega mas Manado area. This study aims to determine the calculation and cutting income tax article 21 for employees of PT. Mega Jasakelola Manado is in compliance with applicable tax laws. This research uses descriptive method by digging company data, conducting and interviewing and testing the data by comparing the results of the company with the results of calculations obtained by the author. Data collected: payroll and calcullation and measurement off taax article 21 on employees of PT. Mega Jasakelola Manado 2017. Results obtained from the calcullation and withholding of incom tax articl 21 onn permanent employess of PT. Mega Jasakelola Manado is in conformity with the taxation laws No. 36 of 2008 and PMK no 101 / PMK.010 / 2016”.Keywords: : Income tax, Tax, Taxpayer, taxation law, permanent employees
19
Arkhimandritova, Serafima, Alexey Shavarda e Elena Potokina. "Key metabolites associated with the onset of flowering of guar genotypes (Cyamopsis tetragonoloba (L.) Taub)". BMC Plant Biology 20, S1 (ottobre 2020). http://dx.doi.org/10.1186/s12870-020-02498-x.
Testo completoAbstract (sommario):
Abstract Background Guar (Cyamopsis tetragonoloba (L.) Taub.), a short-day plant, is an economically valuable legume crop. Seeds of guar serve as a source of galactomannan polysaccharide, known as guar gum, which is in demand in the gas and oil industries. The rapid and complete maturation of guar seeds depends on the flowering time of a particular genotype. It is known that flowering in guar is controlled by several gene systems. However, no information about the process and mechanisms that trigger flowering in guar on the molecular and biochemical levels was previously reported. The aim of the study was to investigate the metabolic landscape underlying transition to the flowering in guar using GC-MS-metabolomic analysis. Results 82 diverse guar genotypes (each in 8 replicates) from the VIR collection were grown under experimental conditions of high humidity and long photoperiod. In the stress environment some guar genotypes turned to flowering early (41 ± 1,8 days from the first true leaf appearance) while for others the serious delay of flowering (up to 95 ± 1,7 days) was observed. A total of 244 metabolites were detected by GC-MS analysis on the third true leaves stage of 82 guar genotypes. Among them some molecules were associated with the transition of the guar plants to flowering. Clear discrimination was observed in metabolomic profiles of two groups of «early flowering» and «delayed flowering» plants, with 65 metabolites having a significantly higher abundance in early flowering genotypes. Among them 7 key molecules were identified by S-plot, as potential biomarkers discriminating of «early flowering» and «delayed flowering» guar genotypes. Conclusions The metabolomic landscape accompanying transition to flowering in guar was firstly described. The results obtained can be used in subsequent genomic research for identifying metabolite-gene associations and revealing genes responsible for the onset of flowering and photoperiod sensitivity of guar. In addition, the detected key metabolites associated with flowering of guar can be employed as biomarkers allowing rapid screening of breeding material for the potentially early flowering genotypes.
20
Yu, Qing, Fang Du, Irla Belli, Patricia A. Gomes, Ioannis Sotiropoulos e Clarissa L. Waites. "Glucocorticoid stress hormones stimulate vesicle-free Tau secretion and spreading in the brain". Cell Death & Disease 15, n. 1 (18 gennaio 2024). http://dx.doi.org/10.1038/s41419-024-06458-3.
Testo completoAbstract (sommario):
AbstractChronic stress and elevated levels of glucocorticoids (GCs), the main stress hormones, accelerate Alzheimer’s disease (AD) onset and progression. A major driver of AD progression is the spreading of pathogenic Tau protein between brain regions, precipitated by neuronal Tau secretion. While stress and high GC levels are known to induce intraneuronal Tau pathology (i.e. hyperphosphorylation, oligomerization) in animal models, their role in trans-neuronal Tau spreading is unexplored. Here, we find that GCs promote secretion of full-length, primarily vesicle-free, phosphorylated Tau from murine hippocampal neurons and ex vivo brain slices. This process requires neuronal activity and the kinase GSK3β. GCs also dramatically enhance trans-neuronal Tau spreading in vivo, and this effect is blocked by an inhibitor of Tau oligomerization and type 1 unconventional protein secretion. These findings uncover a potential mechanism by which stress/GCs stimulate Tau propagation in AD.
21
Liu, Yanchao, Shujuan Zhang, Xiaoguang Li, Enjie Liu, Xin Wang, Qiuzhi Zhou, Jinwang Ye e Jian-Zhi Wang. "Peripheral inflammation promotes brain tau transmission via disrupting blood–brain barrier". Bioscience Reports 40, n. 2 (febbraio 2020). http://dx.doi.org/10.1042/bsr20193629.
Testo completoAbstract (sommario):
Abstract Abnormal aggregation of pathological tau protein is a neuropathological feature of Alzheimer’s disease (AD). In the AD patients, the abnormal tau accumulation first appeared in entorhinal cortex (EC) and then propagated to the hippocampus with microglia activation and inflammation, but the mechanism is elusive. Here, we studied the role and mechanisms underlying periphery inflammation on brain tau transmission. By intraperitoneal injection of lipopolysaccharide (LPS) with brain medial entorhinal cortex (MEC)-specific overexpressing P301L human tau (P301L-hTau), we found that both acute and chronic administration of LPS remarkably promoted P301L-hTau transmission from MEC to the hippocampal subsets. Interestingly, the chronic LPS-induced P301L-hTau transmission was still apparent after blocking microglia activation. Further studies demonstrated that LPS disrupted the integrity of blood–brain barrier (BBB) and simultaneous intraperitoneal administration of glucocorticoid (GC) attenuated LPS-promoted P301L-hTau transmission. These data together suggest that a non-microglia-dependent BBB disruption contributes to peripheral LPS-promoted brain P301L-hTau transmission, therefore, maintaining the integrity of BBB can be a novel strategy for preventing pathological tau propagation in AD and other tauopathies.
22
Nasr, Noha N., Ali M. El-Hagrassi, Yomna R. Ahmed e Manal A. Hamed. "GC/MS and LC‐ESI‐MS analysis of Conocarpus erectus Leaves Extract via Regulating Amyloid‐β‐peptide, Tau protein, Neurotransmitters, Inflammation and Oxidative Stress against AlCl3‐Induced Alzheimer’s Disease in Rats". Chemistry & Biodiversity, 5 ottobre 2024. http://dx.doi.org/10.1002/cbdv.202401960.
Testo completoAbstract (sommario):
This study investigated the therapeutic effect of Conocarpus erectus leaves methanolic extract against AlCl3 ‐induced Alzheimer’s disease (AD) in rats comparing with Donepezil‐hydrochloride as a reference drug. The bioactive compounds of C. erectus leaves were isolated and identified by GC/MS and LC‐ESI‐MS analysis. Malondialdehyde (MDA), reduced glutathione (GSH), superoxide dismutase (SOD), tumor necrosis factor‐alpha (TNF‐α), interleukin‐6 (IL‐6), amyloid‐β‐peptide (Aβ‐peptide), tau protein, acetylcholinesterase (AChE), serotonin (5‐HT), dopamine (DA) and nor‐adrenaline (NE) levels were estimated. The neuromuscular strength, memory behavior and histopathological examination of cerebral cortex region were also conducted. Forty‐three compounds were characterized from the non‐polar fraction of C. erectus L. leaves extract and nineteen compounds were identified from the defatted extract. AlCl3‐ induction caused significant elevation of brain oxidative stress, Aβ‐peptide, tau protein, IL‐6, TNF‐α and AChE levels. A significant decrease in 5‐HT, ND and DA levels were noticed. Additionally, AlCl3 reduced neuromuscular strength and compromised memory function. Treatment of AlCl3‐ induced rats with C. erectuse extract ameliorated these selected parameters by variable degrees. In conclusion, C. erectus protects against AlCl3‐ induced AD in rats through its antioxidant, anti‐inflammatory, and antineutron damage. It could be considered as a new nutraceutical agent for attenuating symptoms associated with Alzheimer's disease.