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1.
Current issues in research on health effects by polyphenols are addressed. As to the cardiovascular system, flow-mediated dilation (FMD), a functional biomarker, can be used as surrogate marker for cardiovascular risk. Acute short-term effects peaking at 2 h after ingestion of polyphenol-rich food items are distinguished from longer-term effects over days and weeks. The role of polyphenol metabolites as bioactives is presented, underlining that specific target enzymes such as NADPH oxidases or lipoxygenases provide a basis for molecular action of polyphenols, rather than unspecific direct antioxidant effects. Cautionary words are given for the use of non-compositional assays of ‘total antioxidant capacity’ (TAC) in blood plasma. Enhanced interest emerges for polyphenols in the gastrointestinal tract. Recommendations for health professionals and the public are summarized, as well as prospects and challenges for future research.  相似文献   

2.
Optical and spectroscopic methods for biofilmexamination and monitoring are reviewed.Biofilm examination techniques includemicroscopic methods, coupled with imageanalysis and with oligonucleotide ribosomal RNAprobing methods (fluorescence in situhybridization). Microscopic examinationtechniques are especially advantageous inextracting biofilm structural and architecturalparameters, as well as structure-functionrelationships of the biofilm microbialpopulation. Spectroscopic techniques are ableto elicit biofilm chemical and metabolicpatterns, as well as biofilm activity. They areof outstanding importance for on-line,non-invasive biofilm monitoring, especiallywhen coupled with chemometric algorithms forspectra calibration and pattern recognition.The paper emphasises the importance of thecombination of novel and established analyticaltechniques, as well as their integration withpowerful computational methods for theautomation of biofilm monitoring.  相似文献   

3.
Liquid and gaseous fuels from biotechnology: challenge and opportunities   总被引:3,自引:0,他引:3  
Abstract: This paper presents challenging opportunities for production of liquid and gaseous fuels by biotechnology. From the liquid fuels, ethyl alcohol production has been widely researched and implemented. The major obstacle for large scale production of ethanol for fuel is the cost, whereby the substrate represents one of the major cost components. Various scenarios will be presented for a critical assessment of cost distribution for production of ethanol from various substrates by conventional and high rate processes. The paper also focuses on recent advances in the research and application of biotechnological processes and methods for the production of liquid transportation fuels other than ethanol (other oxygenates; diesel fuel extenders and substitutes), as well as gaseous fuels (biogas, methane, reformed syngas). Potential uses of these biofuels are described, along with environmental concerns which accompany them. Emphasis is also put on microalgal lipids as diesel substitute and biogas/methane as a renewable alternative to natural gas. The capturing and use of landfill gases is also mentioned, as well as microbial coal liquefaction. Described is also the construction and performance of microbial fuel cells for the direct high-efficiency conversion of chemical fuel energy to electricity. Bacterial carbon dioxide recovery is briefly dealt with as an environmental issue associated with the use of fossil energy.  相似文献   

4.
Biological surfaces are multifunctional interfaces between the organisms and their environment. Properties such as the wettability and adhesion of particles are linked to the micro- and nanostructures of their surfaces. In this study, we used plant and artificial surfaces covered with wax crystals to develop a low-cost replication technique with high resolution. The technique is applicable for fragile surface structures, as demonstrated for three-dimensional wax crystals, and is fast to prevent shrinking of the biological material by water loss during the molding process. Thermal evaporation of octacosan-1-ol has been used to create microstructured surfaces with small platelets as templates for molding. Epoxy resin as filling material provided the smallest deviations from the original surface structures and can be used for replication of nanostructures as small as 4.5 nm. Contact angle measurements of leaves and their replicas show that this technique can be used to develop biomimetic surfaces with similar wettability as in the plant surfaces.  相似文献   

5.
A simple and safe procedure has been described for the preparation of short-chain aliphatic hydroxamic acids in quantities as large as 1 mole and as small as 0.01 mole. The procedure is equally suitable for the preparation of isotopically labeled hydroxamates, as has been demonstrated in the case of 1-14C-acetohydroxamic acid and 3H-acetohydroxamic acid. Some physical and chemical characteristics, including infrared spectra of formo-, aceto-, propiono-, and isobutyro-hydroxamic acids prepared by this method have been described.  相似文献   

6.
Centrifuges are often used in biological studies for 1 x g control samples in space flight microgravity experiments as well as in ground based research. Using centrifugation as a tool to generate an Earth like acceleration introduces unwanted inertial shear forces to the sample. Depending on the centrifuge and the geometry of the experiment hardware used these shear forces may contribute as much as 99% to the total force acting on the cells or tissues. The inertial shear force artifact should be dealt with for future experiment hardware development for Shuttle and the International Space Station (ISS) as well as for the interpretation of previous spaceflight and on-ground research data.  相似文献   

7.
Livestock and aquaculture production is under political and social pressure, especially in the European Union (EU), to decrease pollution and environmental damage arising due to animal agriculture. The EU has banned the use of antibiotics and other chemicals, which have been shown to be effective in promoting growth and reducing environment pollutants because of the risk caused to humans by chemical residues in food and by antibiotic resistance being passed on to human pathogens. As a result of this, scientists have intensified efforts in exploiting plants, plant extracts or natural plant compounds as potential natural alternatives for enhancing the livestock productivity. This paper discusses work on the effects of various phytochemicals and plant secondary metabolites in ruminant and fish species. The focus is on (i) plants such as Ananas comosus (pine apple), Momordica charantia (bitter gourd) and Azadirachta indica (neem) containing anthelmintic compounds and for their use for controlling internal parasites; (ii) plants containing polyphenols and their applications for protecting proteins from degradation in the rumen, increasing efficiency of microbial protein synthesis in rumen and decreasing methane emission; for using as antioxidants, antibacterial and antihelmintic agents; and for changing meat colour and for increasing n-3 fatty acids and conjugated linoleic acid in meat; (iii) saponin-rich plants such as quillaja, yucca and Sapindus saponaria for increasing the efficiency of rumen fermentation, decreasing methane emission and enhancing growth; for producing desired nutritional attributes such as lowering of cholesterol in monogastric animals; for increasing growth of fish (common carp and Nile tilapia) and for changing male to female ratio in tilapia; and for use as molluscicidal agents; (iv) Moringa oleifera leaves as a source of plant growth factor(s), antioxidants, beta-carotene, vitamin C, and various glucosinolates and their degraded products for possible use as antibacterial, antioxidant, anticarcinogenic and antipest agents; (v) Jatropha curcas toxic variety with high levels of various phytochemicals such as trypsin inhibitor, lectin, phytate and phorbol esters in seeds limiting the use of seed meal in fish and livestock diets; and the use of phorbol esters as bio-pesticidal agent; and (vi) lesser-known legumes such as Entada phaseoloides seeds containing high levels of trypsin inhibitor and saponins, Sesbania aculeate seeds rich in non-starch polysaccharides and Mucuna pruriens var. utilis seeds rich in l-3,4-dihydroxyphenylalanine and their potential as fish feed; Cassia fistula seeds as a source of antioxidants; and the use of Canavalia ensiformis, C. gladiata and C. virosa seeds containing high levels of trypsin inhinitor, lectins and canavanine. The paper also presents some challenges and future areas of work in this field.  相似文献   

8.
Plants are important sources of food and plant products are essential for modern human life. Plants are increasingly gaining importance as drug and fuel resources, bioremediation tools and as tools for recombinant technology. Considering these applications, database infrastructure for plant model systems deserves much more attention. Study of plant biological pathways, the interconnection between these pathways and plant systems biology on the whole has in general lagged behind human systems biology. In this article we review plant pathway databases and the resources that are currently available. We lay out trends and challenges in the ongoing efforts to integrate plant pathway databases and the applications of database integration. We also discuss how progress in non-plant communities can serve as an example for the improvement of the plant pathway database landscape and thereby allow quantitative modeling of plant biosystems. We propose Good Database Practice as a possible model for collaboration and to ease future integration efforts.  相似文献   

9.
Neutrophils and immunity: challenges and opportunities   总被引:1,自引:0,他引:1  
Scientists who study neutrophils often have backgrounds in cell biology, biochemistry, haematology, rheumatology or infectious disease. Paradoxically, immunologists seem to have a harder time incorporating these host-defence cells into the framework of their discipline. The recent literature discussed here indicates that it is appropriate for immunologists to take as much interest in neutrophils as in their lymphohaematopoietic cousins with smooth nuclei. Neutrophils inform and shape immune responses, contribute to the repair of tissue as well as its breakdown, use killing mechanisms that enrich our concepts of specificity, and offer exciting opportunities for the treatment of neoplastic, autoinflammatory and autoimmune disorders.  相似文献   

10.
Solid tumors require blood vessels for growth and dissemination, and lymphatic vessels as additional conduits for metastatic spread. The identification of growth factor receptor pathways regulating angiogenesis has led to the clinical approval of the first antiangiogenic molecules targeted against the vascular endothelial growth factor (VEGF)-VEGF receptor (VEGFR)-2 pathway. However, in many cases resistance to anti-VEGF-VEGFR therapy occurs, and thus far the clinical benefit has been limited to only modest improvements in overall survival. Therefore, novel treatment modalities are required. Here, we discuss the members of the VEGF-VEGFR family as well as the angiopoietin growth factors and their Tie receptors as potential novel targets for antiangiogenic and antilymphangiogenic therapies.  相似文献   

11.
Doping and manipulation are undesirable companions of professional and amateur sport. Numerous adverse analytical findings as well as confessions of athletes have demonstrated the variety of doping agents and methods as well as the inventiveness of cheating sportsmen. Besides ‘conventional’ misuse of drugs such as erythropoietin and insulins, experts fear that therapeutics that are currently undergoing clinical trials might be part of current or future doping regimens, which aim for an increased functionality and performance or organs and tissues. Emerging drugs such as selective androgen receptor modulators (SARMs), hypoxia-inducible factor (HIF) complex stabilizers or modulators of muscle fiber calcium channels are considered relevant for current and future doping controls due to their high potential for misuse in sports.Key words: sport, doping, mass spectrometry, anabolics, insulin, HIF, S107  相似文献   

12.
Scale and squamation characters have proved to be useful in investigating phyletic relationships in the family Cichlidae. To provide a sound basis for a cladistic analysis the plesiomorphic states have to be determined. This has been done for the family as a whole as well as for some phyletic lineages. Based on those characters the phylogeny within the family has been investigated.  相似文献   

13.
Copper is required for processes as conserved as respiration and as specialized as protein modification. Recent exciting findings from studies in yeast cells have revealed the presence of specific pathways for copper transport, trafficking and signal transduction that maintain the delicate balance of this essential yet toxic metal ion.  相似文献   

14.
Until relatively recently, in countries such as the U.S.A. and U.K., individuals could only opt for “single race” categories with which they identified. However, in the 2000 decennial census, respondents in the U.S. were able to choose more than one racial category, while in 2001, a “Mixed” box (with further subcategories) was provided in the England and Wales census for the first time. But the very success of this racial project in these countries has spawned a number of questions for policy-makers and academics who theorize, enumerate and study the experiences of multiracial people. With demographic changes such as generational change, who counts as multiracial or mixed race? This question has yet to receive significant attention. Although mixing is becoming more commonplace, the question of who counts as multiracial is far from straightforward, especially as we look down the generational pipeline.  相似文献   

15.
The initial observation that p53 accumulation might serve as a surrogate biomarker for TP53 mutation has been the cornerstone for vast translational efforts aimed at validating its clinical use for the diagnosis, prognosis, and treatment of cancer. Early on, it was realized that accurate evaluation of p53 status and function could not be achieved through protein-expression analysis only. As our understanding of the p53 pathway has evolved and more sophisticated methods for assessment of p53 functional integrity have become available, the clinical and molecular epidemiological implications of p53 abnormalities in cancers are being revealed. They include diagnostic testing for germline p53 mutations, and the assessment of selected p53 mutations as biomarkers of carcinogen exposure and cancer risk and prognosis. Here, we describe the strengths and limitations of the most frequently used techniques for determination of p53 status in tumors, as well as the most remarkable latest findings relating to its clinical and epidemiological value.  相似文献   

16.
Elevation of the level of intracellular reactive oxygen species (ROS) has immense implication in the biological system. On the one hand, ROS promote the signaling cascades for the maintenance of normal physiological functions, the phenomenon referred to as redox biology, and on the other hand increased ROS can cause damages to the cellular macromolecules as well as genetic material, the process known as oxidative stress. Oxidative stress acts as an etiological factor for wide varieties of pathologies, cancer being one of them. ROS is regarded as a “double-edged sword” with respect to oncogenesis. It can suppress as well as promote the malignant progression depending on the type of signaling pathway it uses. Moreover, the attribution of ROS in promoting phenotypic plasticity as well as acquisition of stemness during neoplasia has become a wide area of research. The current review discussed all the aspects of ROS in the perspective of tumor biology with special reference to epithelial-mesenchymal transition (EMT) and cancer stem cells.  相似文献   

17.
The anthrone method for the estimation of mixtures of glucose and fructose, whether present as free sugars or as constituents of sucrose, or of polymers of these monosaccharides has been improved. The appropriate mixed standards for analysis of large numbers of samples have been determined.  相似文献   

18.
Microdialysis sampling has become an important method for the continuous monitoring from an in vivo environment. This technique has been used to monitor many endogenous molecules, such as neurotransmitters, as well as exogenous species such as drug substances. Microdialysis samples have traditionally been analyzed by liquid chromatographic (LC) methods to gain resolution and quantification of the molecules of interest. However, LC separations have a relatively large injection volume requirement which, as a consequence, increases microdialysis sampling times. Capillary electrophoresis (CE), with its very small sample volume requirements and high resolving power, has therefore gained popularity as an alternative to LC. Reviewed here are many of the technologies currently available for CE and examples of how this technique has been effectively applied to the analysis of microdialysis samples.  相似文献   

19.
alpha-D-Mannopyranosyl and alpha-D-mannopyranosyl-(1----2)-alpha-D- mannopyranosyl linked to L-serine and L-threonine have been synthesised as model substances for the linkage region in certain O-linked glycoproteins. Metropolis Monte Carlo simulations were performed with a modified version of the GESA program, to yield theoretical NOEs and interatomic distances as ensemble-average values, and these were compared with results from steady-state NOE experiments. The NOEs were determined as ensemble-average and as global minimum values. NMR chemical shift differences, obtained for signals of the glycopeptides relative to those of the respective monomers, were interpreted in terms of short inter-residue atomic distances as found within the global minima, and on the basis of averaged distances derived from Monte Carlo simulations.  相似文献   

20.
Increases in our understanding of the molecular control of circadian rhythms and subsequent signaling pathways has allowed for new therapeutic drug targets to be identified as well as for a better understanding of how to more efficaciously and safely utilize current drugs. Here, we review recent advances in targeting components of the molecular clock in mammals for the development of novel therapeutics as well as describe the impact of the circadian rhythm on drug efficacy and toxicity.  相似文献   

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