Academic literature on the topic 'Microbe:higher organism interaction'
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Journal articles on the topic "Microbe:higher organism interaction"
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Jackson, T. A., M. O’Callaghan, and T. R. Glare. "Safe Use of Replicating Bacteria in Biological Control." Research Challenges and Needs for Safe Use of Microbial Organisms 79, no. 4 (April 12, 2005): 50–55. http://dx.doi.org/10.7202/706157ar.
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Naturally occurring entomopathogenic bacteria provide an important resource for pest control. Greatest benefit will be obtained from the application of replicating bacteria which can establish in the host's environment and provide long term control. Bacteria developed for pest control are required to be safety tested and registered, yet bacteria are frequently introduced into the environment to enhance plant growth or aid soil processes without regulation. Why then, is the use of insect pathogenic bacteria treated differently? Augmentation of bacteria already present in the environment is unlikely to have any unwanted side effects as application is only changing the spatial and temporal distribution of the microbe and will have little long term effect on the total population. Users of the bacteria, however, will be exposed to the bacterium at a level higher than experienced naturally and potential adverse effects of this interaction should be addressed through Tier 1 safety testing. Non-target organisms should also be tested. If new organisms (exotic strains or modified bacteria) are to be introduced to the environment, their potential effects on the environment should be considered. The question of horizontal gene flow from applied bacteria also needs to be addressed. A better understanding of microbial ecology and Systems for tracking new strains and genes are essential to develop appropriate assessment procedures to ensure the safe utilisation of bacteria in biological control.
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Bording-Jorgensen, M., T. Gartke, H. Armstrong, and E. Wine. "A50 IMPACT OF SHORT CHAIN FATTY ACIDS ON PATHOGENICTY OF COMMENSAL BACTERIA IN PEDIATRIC INFLAMMATORY BOWEL DISEASES." Journal of the Canadian Association of Gastroenterology 5, Supplement_1 (February 21, 2022): 57–58. http://dx.doi.org/10.1093/jcag/gwab049.049.
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Abstract Background Dietary fibers are fermented by microbiota into many different compounds including short-chain fatty acids (SCFA). The gut microenvironment is essential not only for human health but also in maintaining a rich biodiversity of bacterial species. It is well known that the microbiome is altered in Inflammatory Bowel Diseases (IBD), which likely changes the microenvironment and has other health effects on individuals with IBD. Pathobionts are organisms that can induce pathology under specific conditions, and several have already been associated with IBD, such as adherent invasive Escherichia coli (AIEC) and Helicobacter hepaticus. Although these bacteria have been associated with IBD, it is still largely unknown what conditions make these bacteria become pathogenic. Aims Determine the role of SCFA composition on the pathogenic potential of commensal bacteria isolated from non-IBD and IBD pediatric patients. Methods Anaerobic bacteria were isolated during colonoscopy from pediatric IBD and non-IBD patients and identified using 16S sequencing. PMA-activated human monocytes (THP-1) and colonic epithelial cells (Caco2) were grown in the presence of SCFA (acetate, butyrate, formate, propionate, and succinate). The ability of commensal bacteria ( Bacteroides fragilis, Clostridium innocuum, Ruminococcus, Parabacteroides merdae, Bifidobacterium infantis and E. coli HB101) and the pathobiont AIEC to invade cells was assessed using a gentamicin protection assay. Immune activation was quantified with IL-1b and IL-6 by ELISA, as well as reactive oxygen species (ROS) using DCFDHA. Results The SCFA propionate and formate significantly decreased invasion for HB101 and LF82 into macrophages but not epithelial cells. Bacteria isolated from an IBD environment had a higher invasion potential independent of the addition of SCFA, compared to bacteria from a non-IBD environment. However, butyrate was found to significantly increase invasion of non-IBD B. fragilis into Caco2 cells but not macrophages. Bacteria isolated from IBD patients tended to have a higher inflammatory response with both elevated IL-1b as well as ROS production. Conclusions Microenvironment changes, such as in SCFA concentrations, during a disease state can affect the host response to microbes including commensals. Commensal bacteria from IBD patients tend to be more proinflammatory, suggesting that they play a role in driving inflammation. SCFA are beneficial factors for gut health; however, what is still unknown is the interaction between microbes and the host after microenvironmental shifts that likely causes bacterial stress. Understanding the host-microbe interactions and the role diet can have on this dynamic relationship has the potential for discovering new therapeutic options for those suffering from IBD. Funding Agencies CIHRWeston Family Foundation
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Trinchieri, Giorgio. "Innate Immune Signaling in Regulation of Immunity." Blood 128, no. 22 (December 2, 2016): SCI—26—SCI—26. http://dx.doi.org/10.1182/blood.v128.22.sci-26.sci-26.
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Abstract Innate resistance, as an integral part of inflammation, and adaptive immunity participate in oncogenesis and tumor surveillance. For a long time, innate resistance was considered a primitive nonspecific form of resistance to infections that was eclipsed by the potent and specific acquired immunity of higher organisms. More recently, it has been recognized that innate resistance is not only the first line of defense against infections but also sets the stage and is necessary for the development of adaptive immunity. Advances in cancer biology have revealed that the defensive mechanisms of innate resistance and inflammation are indeed manifestations of tissue homeostasis and control of cellular proliferation that have many pleiotropic effects on carcinogenesis and tumor progression and dissemination. The interaction of innate and adaptive immunity with carcinogenesis and tumor progression is complicated and results in effects that either favor or impede tumor progression. Innate immune receptors both sense and regulate the composition of the microbiota, the large number of commensal microorganisms that colonize the barrier surfaces of all multicellular organisms, including those of humans. The microbiota affects many functions of our body and the two together comprise one metaorganism. Microbial imbalance particularly in the gut plays a critical role in the development of multiple diseases, such as cancer, autoimmune conditions and increased susceptibility to infection. Alteration in innate immune signaling and immunity may change the composition of the microbiota affecting tumor initiation both at the barrier sites (e.g. in the gut) and systemically. The commensal microbes not only may affect the development and progression of cancer but they have also important effects on the response to cancer therapy. Mostly through their interaction with innate receptors, commensal microorganisms modulate the ability of the organism to respond to cancer immunotherapy and chemotherapy by affecting the threshold of response of tumor-associated myeloid cells and their ability to sustain anti-tumor immunity. Disclosures No relevant conflicts of interest to declare.
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Scherlach, Kirstin, and Christian Hertweck. "Chemical Mediators at the Bacterial-Fungal Interface." Annual Review of Microbiology 74, no. 1 (September 8, 2020): 267–90. http://dx.doi.org/10.1146/annurev-micro-012420-081224.
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Interactions among microbes are key drivers of evolutionary progress and constantly shape ecological niches. Microorganisms rely on chemical communication to interact with each other and surrounding organisms. They synthesize natural products as signaling molecules, antibiotics, or modulators of cellular processes that may be applied in agriculture and medicine. Whereas major insight has been gained into the principles of intraspecies interaction, much less is known about the molecular basis of interspecies interplay. In this review, we summarize recent progress in the understanding of chemically mediated bacterial-fungal interrelations. We discuss pairwise interactions among defined species and systems involving additional organisms as well as complex interactions among microbial communities encountered in the soil or defined as microbiota of higher organisms. Finally, we give examples of how the growing understanding of microbial interactions has contributed to drug discovery and hypothesize what may be future directions in studying and engineering microbiota for agricultural or medicinal purposes.
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Ellul, S., P. Rausch, A. PIsani, C. Bang, P. Ellul, and A. Franke. "P688 Association of Akkermansia muciniphila with a healthy gut microbiome." Journal of Crohn's and Colitis 15, Supplement_1 (May 1, 2021): S606—S607. http://dx.doi.org/10.1093/ecco-jcc/jjab076.808.
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Abstract Background Comprehensive knowledge of the types and ratios of microbes present in the healthy gastrointestinal human gut is required before any study is attempted to alter the microbiome to treat one condition. Akkermansia muciniphila, a mucin-degrading bacterium, belonging to the phylum Verrucomicrobia, has been inversely associated with inflammation and diabetes whilst it has been internationally proposed as one of the contributors for maintaining a healthy gut and glucose homeostasis. Studies noted that higher amounts of this microorganism in the gut microbiota was linked to a metabolically healthier lifestyle; therefore, linking an interaction between the gut bacterial richness and abundance of A. muciniphila. This organism was noted to improve the gut barrier using its outer membrane protein Amuc 1100, which seems to interact with Toll-like receptor 2, whilst potentially adhering to intestinal epithelial cells, leading its role in balancing the human immunological homeostasis whilst strengthening the monolayer integrity of the wall. The aim of this study was to assess if there is any difference in the presence of Akkermansia muciniphila between IBD patients and controls. Methods Faecal microbiota from newly diagnosed treatment naïve IBD patients and controls were analysed via the bacterial 16s rRNA gene sequencing on illumine MiSeq. Results 100 patients with IBD and 97 controls were recruited. Forty-one different ASVs were identified from our cohort, all of which being differentially abundant between the different health conditions present. From these, 20 ASVs such as ASV-14 G-Alistipes uncl., and ASV 20-Akkermansia muciniphila, were found to be more abundant in healthy individuals than in IBD patients. There was no dietary association. Conclusion In this study Akkermansia muciniphila was significantly found in higher amount in the healthy control population than in the IBD cohort. The potential role of repopulating the gut bacteria with Akkermansia muciniphila needs to be investigated as to reduce the burden of disease, medications prescribed and the clinical outcome.
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Jain, Akansha, and Sampa Das. "Insight into the Interaction between Plants and Associated FluorescentPseudomonasspp." International Journal of Agronomy 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/4269010.
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FluorescentPseudomonasare known for their plant growth promoting and disease protection abilities. In past years, a number of studies have focused on how these bacteria suppress disease and induce resistance. They are known to produce antibiotics and siderophores, promote growth, and induce systemic resistance in the host plant. This bacterium has come out as a model organism for ecological studies going on in rhizosphere and for studying plant-beneficial microbe interaction. This review focuses on the current state of knowledge on biocontrol potential of fluorescentPseudomonasstrains and the mechanisms adopted by them.
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K.S, Vidhya Bharathi, Djanaguiraman M, Raghu R, Jeyakumar P, and Karthikeyan s. "Evaluation of Ecotoxicity of Nanoceria to Organisms of Different Trophic Levels." Madras Agricultural Journal 108, March (2021): 1–5. http://dx.doi.org/10.29321/maj.10.000490.
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he present study was aimed at evaluation of the toxicity potential of nanoceria on phosphobacteria (Bacillus megaterium ; soil ecosystem), azolla (Anabaena azollae and microalgae ; Aquatic ecosystem) and sorghum (Sorghum bicolor (L.) Moench) pollen grain and photosystem (PS) II quantum yield (terrestrial ecosystem). The study examined the differences in toxicity among a different concentration of nanoceria to each organism and differences in toxicity among the organisms. In each toxicity experiment, the concentration of nanoceria used are 0, 5, 10, 25, 50, 100, 200, 400, 500, and 1000 mg L-1. The result indicated that nanoceria is not toxic to soil microbes, aquatic organisms and terrestrial plants at lower concentration (up to 25 mg L-1). However, above 25 mg L-1 concentration, differential responses between nanoceria and organisms were observed. Higher concentration (500 and 1000 mg L-1) inhibited the growth of phosphobacteria, microalgae, and pollen germination and PS II quantum yield. The adverse effect caused by nanoceria could be associated with the concentration of nanoceria, differences in interactions with the cell with nanoceria, and oxidative damage caused by nanoceria. Among the assays, pollen germination was found to be more sensitive to the nanoceria in the medium, followed by photosystem II quantum yield.
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Park, Stacy J., and Borna Mehrad. "Innate Immunity to Aspergillus Species." Clinical Microbiology Reviews 22, no. 4 (October 2009): 535–51. http://dx.doi.org/10.1128/cmr.00014-09.
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SUMMARY All humans are continuously exposed to inhaled Aspergillus conidia, yet healthy hosts clear the organism without developing disease and without the development of antibody- or cell-mediated acquired immunity to this organism. This suggests that for most healthy humans, innate immunity is sufficient to clear the organism. A failure of these defenses results in a uniquely diverse set of illnesses caused by Aspergillus species, which includes diseases caused by the colonization of the respiratory tract, invasive infection, and hypersensitivity. A key concept in immune responses to Aspergillus species is that the susceptibilities of the host determine the morphological form, antigenic structure, and physical location of the fungus. In this review, we summarize the current literature on the multiple layers of innate defenses against Aspergillus species that dictate the outcome of this host-microbe interaction.
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Weitzman, Chava L., Karen Gibb, and Keith Christian. "Skin bacterial diversity is higher on lizards than sympatric frogs in tropical Australia." PeerJ 6 (November 14, 2018): e5960. http://dx.doi.org/10.7717/peerj.5960.
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Animal skin acts as a barrier between the organism and its environment and provides the first line of defense against invading pathogens. Thus, skin surfaces harbor communities of microbes that are interacting with both the host and its environment. Amphibian skin bacteria form distinct communities closely tied to their host species, but few studies have compared bacterial communities between amphibians and other, non-amphibian sympatric animals. Notably, skin microbes on reptiles have gained little attention. We used next-generation sequencing technology to describe bacterial communities on the skin of three lizard species and compared them to bacteria on six cohabiting frog species in the Northern Territory of Australia. We found bacterial communities had higher richness and diversity on lizards than frogs, with different community composition between reptiles and amphibians and among species. Core bacteria on the three lizard species overlapped by over 100 operational taxonomic units. The bacterial communities were similar within species of frogs and lizards, but the communities tended to be more similar between lizard species than between frog species and when comparing lizards with frogs. The diverse bacteria found on lizards invites further questions on how and how well reptiles interact with microorganisms through their scaly skin.
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Han, Lu, and Qi Wang. "Association of Dietary Live Microbe Intake with Cardiovascular Disease in US Adults: A Cross-Sectional Study of NHANES 2007–2018." Nutrients 14, no. 22 (November 20, 2022): 4908. http://dx.doi.org/10.3390/nu14224908.
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Objective: To detect the potential association between dietary live microbe and cardiovascular diseases (CVD). Methods: Data of 10,875 participants aged 18 years or older in this study were collected from the National Health and Nutrition Examination Survey (NHANES). Participants in this study were divided into three groups according to the Sanders dietary live microbe classification system: low, medium, and high dietary live microbe groups. CVD was defined by a combination of self-reported physician diagnoses and standardized medical status questionnaires. The analyses utilized weighted logistic regression models. Results: After the full adjustment for confounders, patients in the medium dietary live microbe group had a low prevalence of CVD in contrast to those in the low dietary live microbe group (OR: 0.78, 95% CI: 0.52–0.99, and p < 0.05), but no significant association with CVD was detected between the high and low dietary live microbe groups. Higher dietary live microbe groups were negatively associated with the prevalence of stroke (p for trend = 0.01) and heart attack (p for trend = 0.01). People who were male were more likely to suffer stroke due to low dietary live microbe (p for interaction = 0.03). Conclusion: A high dietary live microbe intake was associated with a low prevalence of CVD, and the significant association was detected when the analysis was limited to stroke and heart attack.
Books on the topic "Microbe:higher organism interaction"
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Kirchman, David L. Symbioses and microbes. Oxford University Press, 2018. http://dx.doi.org/10.1093/oso/9780198789406.003.0014.
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The book ends with a chapter devoted to discussing interactions between microbes and higher plants and animals. Symbiosis is sometimes used to describe all interactions, even negative ones, between organisms in persistent, close contact. This chapter focuses on interactions that benefit both partners (mutualism), or one partner while being neutral to the other (commensalism). Microbes are essential to the health and ecology of vertebrates, including Homo sapiens. Microbial cells outnumber human cells on our bodies, aiding in digestion and warding off pathogens. In consortia similar to the anaerobic food chain of anoxic sediments, microbes are essential in the digestion of plant material by deer, cattle, and sheep. Different types of microbes form symbiotic relationships with insects and help to explain their huge success in the biosphere. Protozoa are crucial for wood-boring insects, symbiotic bacteria in the genus Buchnera provide sugars to host aphids while obtaining essential amino acids in exchange, and fungi thrive in subterranean gardens before being harvested for food by ants. Symbiotic dinoflagellates directly provide organic material to support coral growth in exchange for ammonium and other nutrients. Corals are now threatened worldwide by rising oceanic temperatures, decreasing pH, and other human-caused environmental changes. At hydrothermal vents in some deep oceans, sulfur-oxidizing bacteria fuel an entire ecosystem and endosymbiotic bacteria support the growth of giant tube worms. Higher plants also have many symbiotic relationships with bacteria and fungi. Symbiotic nitrogen-fixing bacteria in legumes and other plants fix more nitrogen than free-living bacteria. Fungi associated with plant roots (“mycorrhizal”) are even more common and potentially provide plants with phosphorus as well as nitrogen. Symbiotic microbes can provide other services to their hosts, such as producing bioluminescence, needed for camouflage against predators. In the case of the bobtail squid, bioluminescence is only turned on when populations of the symbiotic bacteria reach critical levels, determined by a quorum sensing mechanism.
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Jacobsen, Dean, and Olivier Dangles. Community dynamics in highland watersheds. Oxford University Press, 2017. http://dx.doi.org/10.1093/oso/9780198736868.003.0006.
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Chapter 6 presents the interaction between space and time in determining the organization of natural communities in high altitude heterogeneous waterscapes. After explaining why high altitude waters represent suitable models for examining metacommunity organization, the chapter focuses on dispersal—a central process to allow colonization and establishment of populations in remote localities and to counter local extinctions. Community organization patterns are then described for a variety of organisms living in high altitude waters, from microbes to invertebrates to fish and birds. These patterns reveal that both environmental and spatial variables are generally involved in species assembling. Examples of studies on directional spatial processes (e.g. through wind and water flow), waterscape genetics, and temporal variability (synchrony/asynchrony) are highlighted as promising research areas to increase the current knowledge on high altitude metacommunity dynamics.
Book chapters on the topic "Microbe:higher organism interaction"
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Muthukrishnan, Lakshmipathy. "Encountering the Survival Strategies Using Various Nano Assemblages." In Handbook of Research on Nano-Strategies for Combatting Antimicrobial Resistance and Cancer, 159–87. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-5049-6.ch007.
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The technological advancements have not only made humans more civilized but have also caused the micro-organisms to develop several survival strategies via antimicrobial resistance to keep pace. Such highly developed microbial systems have been classified as superbugs, exhibiting Trojan-horse mechanism. This uncertain behaviour in microbes has challenged humans to scour around novel moiety to shield themselves from the detrimental effects. One such natural phenomenon that has drawn the attention of researchers is the metal-microbe interaction where microbes were found to be controlled during their interaction with metals. Fine tuning could bestow them with enhanced physico-chemical properties capable of controlling life-threatening micro-organisms. Nano forms of metals (nanoparticles, quantum dots, polymeric nanostructures) exhibiting medicinal properties have been implied toward biomedical theranostics. This chapter highlights the mechanistic antimicrobial resistance and the containment strategy using various nano assemblage highlighting its fabrication and bio-molecular interaction.
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Giri, Krishna, Rashmi Paliwal, Deep Chandra Suyal, Gaurav Mishra, Shailesh Pandey, J. P. N. Rai, and P. K. Verma. "Potential Application of Plant-Microbe Interaction for Restoration of Degraded Ecosystems." In Handbook of Research on Uncovering New Methods for Ecosystem Management through Bioremediation, 255–85. IGI Global, 2015. http://dx.doi.org/10.4018/978-1-4666-8682-3.ch011.
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Rapidly increasing human population, urbanization, industrialization, and mining activities have become the serious environmental issue of today's world. Conventional physico-chemical remediation methods are highly expensive and generate secondary waste. However, bioremediation of contaminated ecosystems using indigenous microbes and plants or amalgamation of both has been recognized as a cost effective and eco-friendly method for remediation as well as restoration of polluted or degraded ecosystems. Further, variety of pollutant attenuation mechanisms possessed by microbes and plants makes them more feasible for remediation of contaminated land and water over physico-chemical methods. Plants and microbes act cooperatively to improve the rates of biodegradation and biostabilization of environmental contaminants. This chapter aims to emphasize on potential application of microbes and plants to attenuate the organic and inorganic pollutants from the contaminated sites as well as eco-restoration of mine degraded and jhum lands by way of biodegradation and phytoremediation technologies.
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Kumar, Govind, Pankaj Bhatt, and Shatrohan Lal. "Phytoremediation: A Synergistic Interaction between Plants and Microbes for Removal of Petroleum Hydrocarbons." In Soil Contamination - Threats and Sustainable Solutions. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.93764.
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Rapid industrialization leads to the deterioration of quality of life and the environment. Petroleum hydrocarbon pollution is one of the contributing factors to that. Petroleum hydrocarbons (PHCs) are natural products, and under high temperature and pressure, they are produced by the anaerobic conversion of biomass. Excessive use of PHCs leads to pollution in the agriculturally important soils and the ultimate source of potability of water, that is, groundwater which is gaining significant attention throughout the world. The fortuitous release of PHCs such as gasoline, diesel, and heating oil are common sources of groundwater contamination. The PHC concentrations in groundwater are often above drinking water standards and bioremediation actions have to be taken. Due to their organic nature, PHCs are difficult to degrade as unavailable for microbial action. Due to this, PHCs are the most widespread environmental contaminants. Plant-microbe synergistic association for remediation of PHCs is comprehensive and it is an effective tool for reclamation of soil and environment from these kinds of undesirable materials. In addition to providing plant growth promotion, microbes can degrade PHCs effectively.
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Rosmarin, Caryn. "The Host-Parasite (Microbe) Relationship." In Tutorial Topics in Infection for the Combined Infection Training Programme. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198801740.003.0011.
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No and yes. The skin, oropharynx, upper airways, gastrointestinal tract, and lower female genital tract are full of bacteria, with the highest concentration being in the colon and in dental plaque. Overall, humans are made up of slightly more bacterial cells than human cells; about 40 versus 30 trillion respectively. Although much less prominent, fungi and viruses are also present. In addition to these endogenous microbes, humans come into contact with numerous others on a daily basis—they are inhaled, ingested with food and drink, and picked up on the skin from the environment. Some of these remain in and on the human body for periods of time, while others slough off or die. In contrast to this, there are certain areas of the body where microbial agents are not expected to occur under normal circumstances. These are called sterile sites and include: major organs and their surrounding fluids and capsules; blood and body fluids other than faeces and saliva (yes, including urine!); bone, bone marrow, and joint fluid; subcutaneous tissue, fat, muscle, and tendons; the lower respiratory tract; and some of the genital tract. Microbes only enter these protected sterile sites through various breaches in physical and immunological defences. Again— no and yes. This is a question that has posed much debate over the centuries and seems to evolve as understanding of both humans and microbes expands. Early understanding of infectious diseases was based on the idea that the microbe was an aggressor and the host a passive victim. Currently there is a better understanding of the relationship between microbe and host, which is more of a dance than a war. In order to express an understanding of the relationships between host humans and microbes, a language is required that describes this confusing and complex interaction, especially considering that knowledge in this field is still evolving. The bacteria that reside in or on human bodies on a semi- permanent basis are called normal flora, or indigenous microbiome. Each person has a relatively unique set of fairly stable microbes likely determined by early experience, and continued exposures and diets.
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Kumar, Sudheer, Sukhila Krishnan, and Sushanta Kumar Samal. "Recent Developments of Epoxy Nanocomposites Used for Aerospace and Automotive Application." In Diverse Applications of Organic-Inorganic Nanocomposites, 162–90. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-1530-3.ch007.
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Epoxy resins are widely utilized engineering thermosetting polymers for industrial applications such as aerospace and automotive fields due to their higher mechanical, thermal, and chemical resistance. Recently, polymer nanocomposites have attracted huge attention both in academics and industry because they demonstrated the tremendous enhancement in material properties compared with a neat polymer or traditional micro and macro composites. Traditional composites generally require a high content (˃10%) of the inorganic fillers to bestow the desired mechanical properties. Higher filler content raises the density of the new product, thereby reducing the properties through fragile interfacial interaction among filler and the organic matrix. Furthermore, enhancing filler content makes processability very complicated. However, nanocomposites exhibit improved thermomechanical properties even with a small amount of nanoparticles (≤5%). The chapter provides information about the application of polymer nanocomposites (i.e., aerospace and automotive industries).
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Kumar, Sudheer, Sukhila Krishnan, and Sushanta Kumar Samal. "Recent Developments of Epoxy Nanocomposites Used for Aerospace and Automotive Application." In Research Anthology on Synthesis, Characterization, and Applications of Nanomaterials, 1295–318. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-8591-7.ch054.
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Epoxy resins are widely utilized engineering thermosetting polymers for industrial applications such as aerospace and automotive fields due to their higher mechanical, thermal, and chemical resistance. Recently, polymer nanocomposites have attracted huge attention both in academics and industry because they demonstrated the tremendous enhancement in material properties compared with a neat polymer or traditional micro and macro composites. Traditional composites generally require a high content (˃10%) of the inorganic fillers to bestow the desired mechanical properties. Higher filler content raises the density of the new product, thereby reducing the properties through fragile interfacial interaction among filler and the organic matrix. Furthermore, enhancing filler content makes processability very complicated. However, nanocomposites exhibit improved thermomechanical properties even with a small amount of nanoparticles (≤5%). The chapter provides information about the application of polymer nanocomposites (i.e., aerospace and automotive industries).
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Wani, Robert Serafino, and Satya Das. "Cardiovascular Infections." In Tutorial Topics in Infection for the Combined Infection Training Programme. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780198801740.003.0037.
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Infective endocarditis (IE) is inflammation of the endothelial lining of the heart valves due to infective causes. IE is a rare condition with an incidence rate of three to nine cases per 100,000 population with a male to female ratio of 2:1. The rate is higher in people with unrepaired cyanotic congenital heart disease, prosthetic heart valves and previous endocarditis. Other risk factors for IE include: rheumatic fever (now accounts for < 10% of IE cases in developed countries), degenerative conditions of heart valves, intravenous drug abuse, diabetes, and HIV infection. One third of the cases are now healthcare associated infection (HCAI), particularly with haemodialysis, cardiac surgery, implantable cardiac devices, intravascular lines, and urinary catheters. In the past decade Staphylococcus aureus has replaced viridans streptococci as the leading cause of IE, the rate of enterococcal (mostly E. faecalis) and Bartonella IE has increased, while that of culture negative endocarditis has decreased. Untreated IE is a uniformly fatal condition, but the mortality rate can be reduced to 5–40% with appropriate treatment. There are two important prerequisite steps to the development of IE: 1. A damaged endothelium due to high pressure gradient and turbulent blood flow around a heart valve or septal defect. Fibrin and platelet deposition occur on the roughened endothelium forming a non-infective thrombus or vegetation. 2. Bacteraemia due to endocarditis-prone organisms resulting from trauma to mucous membranes (e.g. oral cavity, urinary, and gastrointestinal tract) or other colonized tissue or foreign body, which is not cleared by host defence mechanisms. Micro-organisms then attach to the damaged endothelium through a specific ligand-receptor interaction (hence the predilection for certain organisms to cause endocarditis, e.g. viridans streptococci from the mouth), colonize the thrombus, and grow and multiply within it to give rise to a mature/infective vegetation, which is the pathological hallmark of IE. Virulent organisms, classically S. aureus, can apparently infect a healthy endocardium. Damage to the endothelium results in valvular incompetence/regurgitation and symptoms and signs of heart failure and when severe, it is a potentially fatal condition that requires urgent valve surgery, even if the infection has fully responded to antimicrobial therapy.
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Smith, Robert B., and Lee J. Siegel. "Future Disasters." In Windows into the Earth. Oxford University Press, 2000. http://dx.doi.org/10.1093/oso/9780195105964.003.0011.
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In 1870, the fall before Ferdinand Hayden’s celebrated exploration of Yellowstone, an Army lieutenant named Gustavus C. Doane guided a small troop into the mysterious high country. Unlike Hayden, Doane did not conduct extensive scientific studies. However, Doane was observant. He said of Yellowstone: . . . As a country for sight seers, it is without parallel. As a field for scientific research it promises great results, in the branches of Geology, Mineralogy, Botany, Zoology, and Ornithology. It is probably the greatest laboratory that nature furnishes on the surface of the globe. . . . Yellowstone’s value as a unique ecological region soon gained recognition when in 1872, it was designated as the first national park in the United States—and in the world. The complex relationships among Yellowstone’s fauna, flora, and geology helped inspire America’s budding conservation ethic, which came to fruition only a century later with widespread recognition of the tenuous interdependence of living organisms and the Earth they occupy. The idea of a greater Yellowstone ecosystem recognized that its living and geological wonders extended beyond the park’s boundaries and into a broader area. The greater Yellowstone ecosystem is defined by the subterranean yet dominant presence of the Yellowstone hotspot, the engine that ultimately drives not only the region’s geology, but also its living organisms. The Rocky Mountains, lifted upward tens of millions of years ago, were pushed perhaps 1,700 feet higher at Yellowstone during the past 2 million years by the upward-bulging hotspot. Today, a line drawn at 6,100 feet elevation roughly demarcates the boundaries of the greater Yellowstone ecosystem. The high altitude is critical in creating the temperature and moisture regimes that gave rise to Yellowstone’s biological wonders and now determine the distribution of its plants and wildlife. In addition, the incredible amount of heat rising from the hotspot is responsible for Yellowstone’s history of volcanism and its geysers and hot springs, rich with exotic microbes that branched off the evolutionary tree at a primitive stage of life on Earth. Yelllowstone’s expansive lodgepole pine forests demonstrate the interaction of the park’s biology and geology. They grow well on rhyolite lava flows that cover most of western and central Yellowstone.
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Goodman, Brian. "Collaborative Mediation." In Advances in Human and Social Aspects of Technology, 21–39. IGI Global, 2012. http://dx.doi.org/10.4018/978-1-4666-0894-8.ch002.
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Individuals are the generators and consumers of content, and in doing so, make up a substantial presence in the literate internet, above and beyond the formal media outlets that make up the minority. Accelerating the explosion of content are Web 2.0 interactions, where participants are encouraged to engage with primary content. These social spaces are a platform, supporting often-overlooked micro-interactions referred to in this chapter as digital fingerprints. In parallel, companies construct web experiences that uniquely deliver Internet inspired experiences. However, the competition that divides popular Internet destinations is absent in well run intranets. Collaboration and cooperation among internal web properties offer a unique opportunity to organize people and information across disparate experiences. An example of such a solution is IBM’s Enterprise Tagging System, a collaborative classification and recommendation service that knits employee identities and destinations together through fingerprints. The benefit of creating such a common service also exhibits the side effect and power of the relative few participants. It introduces the desperate need to consider how actions and relationships affect user experiences. The success of social systems requires a high level of diverse participation. This diversity is what ensures the mediation and influence of co-creation and collaborative filtering is not overly narrow.
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Simpson, Michael L., and Timothy E. McKnight. "The Biology of Integration of Cells into Microscale and Nanoscale Systems." In Cellular Computing. Oxford University Press, 2004. http://dx.doi.org/10.1093/oso/9780195155396.003.0013.
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In chapter 5 we focused on the informational interface between cells and synthetic components of systems. This interface is concerned with facilitating and manipulating information transport and processing between and within the synthetic and whole-cell components of these hybrid systems. However, there is also a structural interface between these components that is concerned with the physical placement, entrapment, and maintenance of the cells in a manner that enables the informational interface to operate. In this chapter we focus on this structural interface. Successful integration of whole-cell matrices into microscale and nanoscale elements requires a unique environment that fosters continued cell viability while promoting, or at least not blocking, the information transport and communication pathways described in earlier chapters. A century of cell culture has provided a wealth of insight and specific protocols to maintain the viability and (typically) proliferation of virtually every type of organism that can be propagated. More recently, the demands for more efficient bioreactors, more compatible biomedical implants, and the promise of engineered tissues has driven advances in surface-modification sciences, cellular immobilization, and scaffolding that provide structure and control over cell growth, in addition to their basic metabolic requirements. In turn, hybrid biological and electronic systems have emerged, capable of transducing the often highly sensitive and specific responses of cellular matrices for biosensing in environmental, medical, and industrial applications. The demands of these systems have driven advances in cellular immobilization and encapsulation techniques, enabling improved interaction of the biological matrix with its environment while providing nutrient and respiratory requirements for prolonged viability of the living matrices. Predominantly, such devices feature a single interface between the bulk biomatrix and transducer. However, advances in lithography, micromachining, and micro-/nanoscale synthesis provide broader opportunities for interfacing whole-cell matrices with synthetic elements. Advances in engineered, patterned, or directed cell growth are now providing spatial and temporal control over cellular integration within microscale and nanoscale systems. Perhaps the best defined integration of cellular matrices with electronically active substrates has been accomplished with neuronal patterning. Topographical and physicochemical patterning of surfaces promotes the attachment and directed growth of neurites over electrically active substrates that are used to both stimulate and observe excitable cellular activity.
Conference papers on the topic "Microbe:higher organism interaction"
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Zarzecki, M., and F. J. Diez. "High Speed Micro Holographic PIV Measurements of Microorganisms." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-69272.
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Holographic particle image velocimetry (PIV) is a novel application of holography that allows for tracking of small particle sized objects in a small volume. Whereas regular PIV allows for the two in-plane components of the velocity field to be measured, and stereoscopic PIV allows for the three-components of the velocity field to be measured in a thin plane, holographic PIV allows for the three-components of the velocity to be measured for each individual particle present in the measuring volume, thus allowing to fully resolve fluid flows that are inherently 3D in nature. There are many examples of three dimensional flows in nature including turbulence flows, but another very interesting application very well suited for this technique involves tracking living microorganisms in order to study their motion and their means of propulsion. As part of this research a micro organism was tracked in three dimensions using a high speed microscopic holographic imaging method. The ability to track organisms in 3D allows better understanding and characterizing of their behavior including their propulsion methods, their feeding methods and their interaction with each other. The time resolved holograms were reconstructed in Matlab using Fast Fourier Transforms. A laser pointer was used as a source of coherent light, and a high speed PIV camera (Photron APX Ultima) was used to capture the images. A beam expander was used to increase the diameter of the laser beam allowing for a larger tracking area. Results with this system will show the trajectories in 3D of microorganisms as well as the three components of the velocity field showing the interaction of the organisms with their environment.
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Lehmann, S., and G. Marowsky. "Quasi-phasematched sum frequency generation in active-passive hybrid waveguides." In Organic Thin Films for Photonic Applications. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/otfa.1995.thb.4.
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Nonlinear optical interactions in waveguides have attracted considerable interest in the past few years. Various classes of materials have been investigated for this purpose. Of these, optically nonlinear polymers have been the focus of intensive research [1]. Their merits render them attractive for use in the development of optoelectronic devices. Quasi-phasematching is a versatile technique for second-order nonlinear processes. The phase-velocity mismatch between interacting waveguide modes at frequencies ωi (i = 1,2,3) is compensated for by a spatial modulation of the material nonlinearity with a period corresponding to the coherence length [2,3]. Active-passive hybrid waveguides combine the high optical quality of glass waveguides with the strong nonlinearity of poled polymers. Here, the guided modes interact via the evanescent field. For sum frequency (SF) generation in isotropic materials the phase mismatch is large, i.e. the coherence length is only a few microns, which increases by at least two orders of magnitude upon utilizing the mode dispersion of the waveguide [4].
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Pickering, Karen D., Eugene K. Ungar, Leticia M. Vega, and Melissa L. Campbell. "Fluid Mechanics and Biological Interaction in a Tubular Nitrifier Designed for Use in Space." In ASME 2000 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2000. http://dx.doi.org/10.1115/imece2000-1420.
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Abstract Biological processes are currently being investigated for use in spacecraft wastewater treatment. In a biological wastewater processor, microorganisms are used to degrade organic and inorganic contaminants to carbon dioxide, water, and other metabolic products. One step in the process is nitrification, in which ammonium ions in the wastewater stream are converted to nitrate ions. Traditional reactor designs for nitrification, which include continuously stirred tank reactors and trickling filters, are unsuitable for use on spacecraft due to their reliance on gravity for aeration. A tubular reactor for aerobic nitrification in a microgravity environment has been developed to allow use of biological systems for wastewater treatment on spacecraft. The tubular reactor uses a 3.2 mm ID tube 305 m long with co-current air and wastewater flow. Aerobic microbes grow on the tube walls. Because of the small tube diameter and the high surface tension of the wastewater, the air/wastewater flow is gravity independent. Thus it is expected that the fluid flow and biological performance will be identical in Earth-normal gravity and in flight.
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Zhao, Daguan, Mohan Yu, Logan Lawrence, Pier Paolo Claudio, James B. Day, and Roozbeh (Ross) Salary. "Investigation of the Influence of Consequential Design Parameters on the Mechanical Performance of Biodegradable Bone Scaffolds, Fabricated Using Pneumatic Micro-Extrusion Additive Manufacturing Process." In ASME 2020 15th International Manufacturing Science and Engineering Conference. American Society of Mechanical Engineers, 2020. http://dx.doi.org/10.1115/msec2020-8512.
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Abstract Pneumatic micro-extrusion (PME) is a high-resolution direct-write additive manufacturing process, which has emerged as the process of choice for tissue engineering and biofabrication of a broad spectrum of organs and tissues (e.g., bone, aortic valve, blood vessels, human ear, and nose). Despite the advantages and host of biomedical applications engendered by the PME process — including, for example, (i) accommodation of a wide range of material viscosity (enabled via thermopneumatic material deposition), (ii) large build volume and standoff distance for tissue engineering, (iii) in situ UV curing, and (iv) high-resolution multimaterial deposition — there are intrinsically complex design, material, and process factors as well as interactions, which influence the functional properties of PME-fabricated tissues and organs. Consequently, investigation of the impact and interaction of each factor aligned with establishment of a physics-based, optimal material deposition regime is inevitably a burgeoning need. In this study, using the Taguchi design, the influence of four significant factors, i.e., layer height, infill density, infill pattern, and print speed, is investigated on the compression properties as well as the dimensional accuracy of polycaprolactone (PCL) bone scaffolds, fabricated using the PME process. Furthermore, a 3D, transient two-phase flow CFD model is forwarded with the aim to observe the flow of material within the deposition head as well as the micro-capillary (nozzle). The results of this study pave the way for further investigation of the bio-functional properties of bone scaffolds, e.g., biodegradation, cell proliferation and growth rate.
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Banneyake, B. M. R. U., and Debjyoti Banerjee. "Microfluidic Device for Synthesis of Lipid Bi-Layers." In ASME 2008 Fluids Engineering Division Summer Meeting collocated with the Heat Transfer, Energy Sustainability, and 3rd Energy Nanotechnology Conferences. ASMEDC, 2008. http://dx.doi.org/10.1115/fedsm2008-55219.
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Lipid bi-layers are ubiquitous components of biological cells — and are found in variety of cell components ranging from cell membranes to membranes of organelles inside the cells. In biological membranes, lipid bi-layer membranes carry membrane proteins, which serve as single channel nanopores that are used to study transport of proteins and characterize the properties of proteins. However, lipid bi-layers have very short half lives, which are usually less than an hour. The lipid bi-layers are usually obtained by physico-chemical interactions between a lipid containing organic solvent, an aqueous buffer solution and a hydrophobic surface. We have developed a continuous flow through microfluidic device using pressure driven flow (by means of a tandem syringe pump system) for synthesis of lipid bi-layers. The microfluidic device consists of two glass substrates with micro-channels and microchambers microfabricated using photolithography and wet glass etching. The microchannels in each substrate is in the form of “+” shape and form a mirror image of each other. A Teflon sheet (∼200 microns thickness) is sandwiched between the glass substrates with a ∼200 microns diameter hole etched in the center to communicate with the two sets of microchannels. A lipid solution in an organic solvent (Pentane) and KCl buffer solution are alternately flown through the legs of the microchannel. The conductivity of the buffer is monitored using a current amplifier. The formation of the lipid bi-layer is confirmed by monitoring the resistivity and the impedance to high frequency electrical oscillations. The flow rate in the microfluidic device is optimized to obtain the lipid bi-layer.
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Fu, Jing, and Sanjay B. Joshi. "Optimization Based Geometric Modeling of Nano/Micro Scale Ion Milling of Organic Materials." In ASME 2009 International Design Engineering Technical Conferences and Computers and Information in Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/detc2009-87134.
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Recently, Focused Ion Beam (FIB) instruments have begun be applied to organic materials such as polymers and biological systems. This provides a novel tool for sectioning biological samples for analysis, or microfabrication with environment friendly materials. The modeling of nano/micro scale geometry accurately sculptured by FIB milling is crucial for generating the milling plan and process control, and for computer simulation for prediction and visualization of the milled geometry. However, modeling of the ion milling process on compound materials, especially for high aspect ratio feature, is still difficult due to the complexity of target material, as well as multiple physical and chemical interactions involved. In this study, a comprehensive model of ion milling with organic targets is presented to address the challenges using a simulation based approach. This platform has also been validated by milling different features on water ice in a cryogenic environment, and the simulation and experiment results show great consistency. With the proliferation of nanotechnology to biomedical and biomaterial domains, the proposed approach is expected to be a flexible tool for various applications involving novel and heterogeneous milling targets.
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Yee, Shannon K., Nelson Coates, Jeffrey J. Urban, Arun Majumdar, and Rachel A. Segalman. "A High-Performance Solution-Processable Hybrid Thermoelectric Material." In ASME 2012 Third International Conference on Micro/Nanoscale Heat and Mass Transfer. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/mnhmt2012-75002.
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Thermoelectrics have the potential to become an alternative power source for distributed electrical generation as they could provide co-generation anywhere thermal gradients exist. More recent material and manufacturing advances have further suggested that thermoelectrics could independently generate primary power [1]. However, due to cost, manufacturability, abundance, and material performance, the full potential of thermoelectrics has yet to be realized. In the last decade, thermoelectric material improvements have largely been realized by diminishing thermal conductivities via nanostructuring without sacrificing performance in electrical transport [2]. An alternative approach is to decouple and optimize the electrical conductivity and thermopower using the unique properties of organic-inorganic interfaces [3]. One method to do this could leverage the electrical properties of a conducting polymer in combination with the thermoelectric proprieties of an inorganic semiconductor in such a way that the interaction between these materials breaks mixture theory. Furthermore, it is expected that the thermal conductivity of this hybrid material would be low due to the inherent vibration mode mismatch between polymers and inorganics. Previously, we have developed a method for producing a solution-processable thermoelectric material suitable for thin film applications using a hybrid polymer-inorganic systems consisting of crystalline tellurium nanowires coated in a thin layer of a conducting polymer (i.e., PEDOT:PSS) [4]. The interfacial properties could be realized in bulk and films demonstrate enhanced transport properties beyond those of either component. More recently, we have been able to significantly improve the thermoelectric properties of these materials by morphological and chemical modifications. Here, we present our methodology and experimental transport properties of this new material where the thermal conductivity, electrical conductivity, and thermopower predictably vary as a function of composition, size, and the structural conformation caused by the solvent. The mechanism for these improvements is currently under investigation, but experimental results suggest that transport is dominated by interfacial phenomena. Furthermore, experiments suggest that both the electrical conductivity and thermopower can be independently increased without appreciably increasing the thermal conductivity. These improvements, in concert with the solution processable nature of this material, make it ideal for new thermoelectric applications.
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Bharath, Sudharsan, M. Balaji, and G. R. Sai Krishna. "Future of NEMS." In ASME 2008 First International Conference on Micro/Nanoscale Heat Transfer. ASMEDC, 2008. http://dx.doi.org/10.1115/mnht2008-52239.
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Nanorobots are quintessential NEMS (nanoelectromechanical systems) and raise all the important issues that must be addressed in NEMS design: sensing, actuation, control, communications, power, and interfacing across spatial scales and between the organic/inorganic and biotic/abiotic realms. Nanorobots are expected to have evolutionary applications in such areas as environmental monitoring and health care. This paper begins by discussing nanorobot construction, which is still at an embryonic stage. The emphasis is on nanomachines, an area which has seen a spate of rapid progress over the last few years. Nanoactuators will be essential components of future NEMS. The paper’s focus then changes to nanoassembly by manipulation with scanning probe microscopes (SPMs), which is a relatively well established process for prototyping nanosystems. Prototyping of nanodevices and systems is important for design validation, parameter optimization and sensitivity studies. Nanomanipulation also has applications in repair and modification of nanostructures built by other means. High throughput SPM manipulation may be achieved by using multi tip arrays. Experimental results are presented which show that interactive SPM manipulation can be used to accurately and reliably position molecular-sized components. These can then be linked by chemical means to form subassemblies, which in turn can be further manipulated. Applications in building wires, single electron transistors and nanowaveguides are presented.
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Nain, Amrinder S., Eric Miller, Metin Sitti, Phil Campbell, and Cristina Amon. "Fabrication of Single and Multi-Layer Fibrous Biomaterial Scaffolds for Tissue Engineering." In ASME 2008 International Mechanical Engineering Congress and Exposition. ASMEDC, 2008. http://dx.doi.org/10.1115/imece2008-67964.
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For regenerative medicine applications, we need to expand our understanding of the mechanisms by which nature assembles and functionalizes specialized complex tissues to form a complete organism. The first step towards this goal involves understanding the underlying complex mechanisms of highly organized behavior spanning not only diverse scientific fields, but also nano, micro and macro length-scales. For example, an engineered fibrous biomaterial scaffold possessing the hierarchal spatial properties of a native extracellular matrix (ECM) can serve as a building block upon which living cells are seeded for repair or regeneration. The hierarchical nature of ECM along with the inherent topological constraints of fiber diameter, fiber spacing, multi-layer configurations provide different pathways for living cells to adapt and conform to the surrounding environment. Our previously developed Spinneret based Tunable Engineered Parameters (STEP) technique to deposit biomaterial scaffolds in aligned configurations has been used for the first time to deposit single and multi-layer biological scaffolds of fibrinogen. Fibrinogen is a very well established tissue engineering scaffold material, as it improves cellular interactions and allows scaffold remodeling compared to synthetic polymers. Current state-of-the-art fiber deposition techniques lack the ability to fabricate scaffolds of desired fiber dimensions and orientations and in this study we present fabrication and aligned deposition of fibrinogen fiber arrays with diameters ranging from sub-200 nm to sub-microns and several millimeters in length. The fabricated scaffolds are then cultured with pluripotent mouse C2C12 cells for seven days and cells on the scaffolds are observed to elongate resembling myotube morphology along the fiber axis, spread along intersecting layers and fuse into bundles at the macroscale. Additionally, we demonstrate the ability to deposit poly (lactic-co-glycolic acid) (PLGA), Polystyrene (PS) biomaterial scaffolds of different diameters to investigate the effects of topological variations on cellular adhesion, proliferation and migration. Previous studies have indicated cells making right angle transitions upon encountering perpendicular double layer fibers and cellular motion is thwarted in the vicinity of diverging fibers. Current ongoing studies are aimed at determining the effects of fiber diameter and fiber spacing on mouse C2C12 cellular adhesion and migration, which are envisioned to aid in the design of future scaffolds for tissue engineering possessing appropriate material and geometrical properties.
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Klemstine, Cole, Yousef Abdelgaber, Logan Lawrence, James B. Day, Pier Paolo Claudio, and Roozbeh (Ross) Salary. "Characterization of the Compressive Properties of Triply Periodic Minimal Surface PCL Scaffolds for Bone Tissue Engineering." In ASME 2021 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/imece2021-72125.
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Abstract Pneumatic micro-extrusion (PME) is a high-resolution direct-write additive manufacturing method, which has been widely utilized for the fabrication of biological tissues, structures, and organs. The PME process allows for non-contact, multi-material deposition of a wide range of functional bio-inks for tissue engineering applications. However, the PME process is inherently complex, governed by complex multi-physics phenomena. Consequently, investigation of the effects of significant process parameters and their interactions on scaffold functional properties would be inevitable. The overarching goal of this research work is to fabricate biocompatible, biodegradable, and porous bone scaffolds for the treatment of large osseous fractures. In pursuit of this goal, the objective of the work is to investigate the compressive properties of triply periodic minimal surface (TPMS) bone scaffolds, composed of polycaprolactone (PCL) and fabricated using the PME additive manufacturing process. In this study, the experimental characterization of TPMS bone scaffolds was on the basis of a designed experiment. The compressive properties of the fabricated bone scaffolds were measured using a compression testing machine. Diamond as well as Icosahedron designs led to fabricated bone scaffolds having relatively high compression moduli. The results of this study pave the way for optimal fabrication of complex bone scaffolds for the treatment of bone fractures and defects.
Reports on the topic "Microbe:higher organism interaction"
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Dickman, Martin B., and Oded Yarden. Genetic and chemical intervention in ROS signaling pathways affecting development and pathogenicity of Sclerotinia sclerotiorum. United States Department of Agriculture, July 2015. http://dx.doi.org/10.32747/2015.7699866.bard.
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Abstract: The long-term goals of our research are to understand the regulation of sclerotial development and pathogenicity in S. sclerotior11111. The focus in this project was on the elucidation of the signaling events and environmental cues involved in the regulation of these processes, utilizing and continuously developing tools our research groups have established and/or adapted for analysis of S. sclerotiorum, Our stated objectives: To take advantage of the recent conceptual (ROS/PPs signaling) and technical (amenability of S. sclerotiorumto manipulations coupled with chemical genomics and next generation sequencing) developments to address and extend our fundamental and potentially applicable knowledge of the following questions concerning the involvement of REDOX signaling and protein dephosphorylation in the regulation of hyphal/sclerotial development and pathogenicity of S. sclerotiorum: (i) How do defects in genes involved in ROS signaling affect S. sclerotiorumdevelopment and pathogenicity? (ii) In what manner do phosphotyrosinephosphatases affect S. sclerotiorumdevelopment and pathogenicity and how are they linked with ROS and other signaling pathways? And (iii) What is the nature of activity of newly identified compounds that affect S. sclerotiori,111 growth? What are the fungal targets and do they interfere with ROS signaling? We have met a significant portion of the specific goals set in our research project. Much of our work has been published. Briefly. we can summarize that: (a) Silencing of SsNox1(NADPHoxidase) expression indicated a central role for this enzyme in both virulence and pathogenic development, while inactivation of the SsNox2 gene resulted in limited sclerotial development, but the organism remained fully pathogenic. (b) A catalase gene (Scatl), whose expression was highly induced during host infection is involved in hyphal growth, branching, sclerotia formation and infection. (c) Protein tyrosine phosphatase l (ptpl) is required for sclerotial development and is involved in fungal infection. (d) Deletion of a superoxidedismutase gene (Sssodl) significantly reduced in virulence on both tomato and tobacco plants yet pathogenicity was mostly restored following supplementation with oxalate. (e) We have participated in comparative genome sequence analysis of S. sclerotiorumand B. cinerea. (f) S. sclerotiorumexhibits a potential switch between biotrophic and necrotrophic lifestyles (g) During plant microbe interactions cell death can occur in both resistant and susceptible events. Non pathogenic fungal mutants S. sclerotior111n also cause a cell death but with opposing results. We investigated PCD in more detail and showed that, although PCD occurs in both circumstances they exhibit distinctly different features. The mutants trigger a restricted cell death phenotype in the host that unexpectedly exhibits markers associated with the plant hypersensitive (resistant) response. Using electron and fluorescence microscopy, chemical effectors and reverse genetics, we have established that this restricted cell death is autophagic. Inhibition of autophagy rescued the non-pathogenic mutant phenotype. These findings indicate that autophagy is a defense response in this interaction Thus the control of cell death, dictated by the plant (autophagy) סr the fungus (apoptosis), is decisive to the outcome of certain plant microbe interactions. In addition to the time and efforts invested towards reaching the specific goals mentioned, both Pls have initiated utilizing (as stated as an objective in our proposal) state of the art RNA-seq tools in order to harness this technology for the study of S. sclerotiorum. The Pls have met twice (in Israel and in the US), in order to discuss .נחd coordinate the research efforts. This included a working visit at the US Pls laboratory for performing RNA-seq experiments and data analysis as well as working on a joint publication (now published). The work we have performed expands our understanding of the fundamental biology (developmental and pathogenic) of S. sclerotioז111וז. Furthermore, based on our results we have now reached the conclusion that this fungus is not a bona fide necrotroph, but can also display a biotrophic lifestyle at the early phases of infection. The data obtained can eventually serve .נ basis of rational intervention with the disease cycle of this pathogen.
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Methodology of sports working capacity level increase in basketball players on the basis of stimulation and rehabilitation means. Viktor V. Andreev, Igor E. Konovalov, Dmitriy S. Andreev, Aleksandr I. Morozov, March 2021. http://dx.doi.org/10.14526/2070-4798-2021-16-1-5-11.
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The increased level of modern sport development increases the demands claimed on different aspects of the training process with further rehabilitation organization and realization. That is why we still have the problem of an adequate and effective integral system creation. The mentioned direction has a direct connection with the activity of scientists, coaches- practitioners and sports clubs. They have to work within one mechanism of interaction. Materials. Studying the level of working capacity influence stimulation and organism rehabilitation means on an organism of basketball players from higher educational establishments on the basis of a wildgrowing plant root “snowdon rose” (Rhodiola rosea), classical massage with special oils and contrast shower application. Research methods. The following methods were used in the experiment: scientific-methodical sources analysis concerning the level of working capacity and athletes’ functional rehabilitation increase; functional tests; the received video material with the indices analysis; mathematical statistics. The research realization was on the basis of N.F. Katanov State University, Khakassia and Khakassia Technical Institute (branch) of Siberian Federal University in Abakan. Results. During the research work we stated qualitative and quantitative indices of athletes’ coordinating endurance with the help of video together with other mentioned above rehabilitation means; the received results were handled and we revealed positive changes in the studied information values of basketball players’ motor sphere and respiratory system. Conclusion. The results analysis, received after the research, helped to come to the following conclusion: out of the presented components the biological factor in a form of a wild-growing plant root “snowdon rose” (Rhodiola rosea) has the main influence on the working capacity and functional rehabilitation of basketball players’ organisms.