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1.
This article describes the calibration of a spectroscopic scanning instrument for the measurement of selected contaminants in a complex biological process stream. Its use is for the monitoring of a process in which contaminants are to be removed selectively by flocculation from yeast cell homogenate. The main contaminants are cell debris, protein, and RNA. A low-cost instrument has been developed for sensitivity in the region of the NIR spectrum (from 1900 to 2500 nm) where preliminary work found NIR signatures from cell debris, protein, and RNA. Calibration models have been derived using a multivariate method for concentrations of these contaminants, such as would be found after the flocculation process. Two strategies were compared for calibrating the NIR instrument. In one case, samples were prepared by adding materials representative of the contaminants to clarified yeast homogenate so the contaminant levels were well known but outside the range of interest. In the other case, where samples were like those from the process stream after flocculation and floc removal, there was uncertainty of analysis of contaminant level, but the calibration was in the range of interest. Calibration using process stream samples gave results close to those derived from traditional assays. When the calibration models were used to predict the contaminant concentrations in previously unseen samples, the correlation coefficients between measurements and predictions were above 90% in all cases but one. The prediction errors were similar to the errors in the traditional assays.  相似文献   

2.
There is an increasing interest in the detection and enumeration of micro‐organisms pathogenic for human and present in bovine faeces. This interest is because pollution of the environment by animal faeces may affect the safety of food and of drinking or recreational water. Detection and quantification of microbial pathogens carried out using DNA extracted from the faecal matrix are affected by the quality and the quantity of the DNA extracts, which are critical factors that limit the accuracy and sensitivity of molecular studies. This review compares published methods on DNA extraction from bovine faeces, focusing on the extent to which the success of DNA amplification is affected by issues related to the faeces. Following a general discussion on the DNA extraction methods used for faeces, we focus particularly on issues related to the faecal environment itself. The objective is to identify information that can be used to improve the sensitivity of those PCR methods used after direct DNA extraction.  相似文献   

3.
蛋白质功能研究:历史、现状和将来   总被引:6,自引:0,他引:6  
马静  葛熙  昌增益 《生命科学》2007,19(3):294-300
蛋白质是生命活动的直接执行者,参与生命的几乎所有过程,如遗传、发育、繁殖、物质和能量的代谢、应激等等。揭示生物体内成千上万种蛋白质的具体功能、完成功能的机制等是蛋白质研究的核心内容,是后基因组时代生命科学研究极富挑战的领域之一。本文就蛋白质功能研究的历史、现状和未来进行简要的讨论。希望能够帮助读者,特别是那些并不从事蛋白质研究的读者,更好地认识我国中长期科学与技术发展规划中制定“蛋白质研究”重大科学计划的必要性。  相似文献   

4.
In the viviparous gyrodactylids, embryos develop one inside another within the parental uterus, a phenomenon with major implications for the biology of this species-rich group. Development occurs via two routes: first-born daughters develop at the centre of an embryo cluster in utero, whereas all other daughters develop from oocytes. The resulting offspring are, however, morphologically indistinguishable. We review here the history of gyrodactylid embryology in the context of current knowledge and, present additional cytogenetic and ultrastructural observations of embryonic development. These progenetic parasites are highly modified for viviparity; oocyte maturation and sperm storage occur in a single chamber, the Egg Cell Forming Region, and a mature oocyte passes into the uterus after the birth of the preceding, fully developed offspring. The uterus has a syncytial lining derived from anterior and posterior cap cells. These cells are the first to differentiate in the female reproductive system and may be involved in controlling development. Embryos receive nutrients via the uterus rather than from vitelline cells. Traditionally, development of the first-born daughter has been considered a form of polyembryony, although paedogenesis has also been suggested. In contrast to previous studies, we could not trace lineage of the first-born daughter to a single quiescent macromere. However, only mitotic divisions have been conclusively observed in the intraembryonic generation, indicating an asexual origin. All other daughters are formed from meiotically derived oocytes by sexual reproduction or automictic parthenogenesis. The latter may involve pre-meiotic doubling of chromosomes, but the precise mechanism and the relative proportion of sexual and parthenogenetic offspring are unknown. Exceptionally, cleavage in Gyrodactylus spp. occurs by duets rather than quartets (a pattern previously only recorded in acoels) and is characterised by extensive cell rearrangements. Blastomeres may be connected by fine cytoplasmic processes or completely disassociated and are readily redistributed by the muscular actions of the parental uterus. This process resembles 'Blastomeren-Anarchie' of rhabdocoels but without the structural support of vitelline cells. It prevents generation of early cell fate maps and indicates regulative, rather than mosaic, development. Structures such as the gut and excretory system differentiate late, and are highlighted, together with the attachment apparatus, as examples of post-embryonic differentiation. Molecular and cellular techniques are now essential to further elucidate mechanisms of gyrodactylid reproduction, which will in turn contribute to current debates with animal embryology.  相似文献   

5.
Metabolomics: current technologies and future trends   总被引:12,自引:0,他引:12  
Hollywood K  Brison DR  Goodacre R 《Proteomics》2006,6(17):4716-4723
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6.
In recent years, as a knowledge-based discipline, bioinformatics has been made more computationally amenable. After its beginnings as a technology advocated by computer scientists to overcome problems of heterogeneity, ontology has been taken up by biologists themselves as a means to consistently annotate features from genotype to phenotype. In medical informatics, artifacts called ontologies have been used for a longer period of time to produce controlled lexicons for coding schemes. In this article, we review the current position in ontologies and how they have become institutionalized within biomedicine. As the field has matured, the much older philosophical aspects of ontology have come into play. With this and the institutionalization of ontology has come greater formality. We review this trend and what benefits it might bring to ontologies and their use within biomedicine.  相似文献   

7.
Stable isotope labeling with amino acids in cell culture (SILAC) has risen as a powerful quantification technique in mass spectrometry (MS)–based proteomics in classical and modified forms. Previously, SILAC was limited to cultured cells because of the requirement of active protein synthesis; however, in recent years, it was expanded to model organisms and tissue samples. Specifically, the super-SILAC technique uses a mixture of SILAC-labeled cells as a spike-in standard for accurate quantification of unlabeled samples, thereby enabling quantification of human tissue samples. Here, we highlight the recent developments in super-SILAC and its application to the study of clinical samples, secretomes, post-translational modifications and organelle proteomes. Finally, we propose super-SILAC as a robust and accurate method that can be commercialized and applied to basic and clinical research.  相似文献   

8.
Oncoproteomics is the application of proteomics technologies in oncology. Functional proteomics is a promising technique for the rational identification of biomarkers and novel therapeutic targets for cancers. Recent progress in proteomics has opened new avenues for tumor-associated biomarker discovery. With the advent of new and improved proteomics technologies, such as the development of quantitative proteomic methods, high-resolution, -speed and -sensitivity mass spectrometry and protein arrays, as well as advanced bioinformatics for data handling and interpretation, it is now possible to discover biomarkers that can reliably and accurately predict outcomes during cancer management and treatment. However, there are several difficulties in the study of proteins/peptides that are not inherent in the study of nucleic acids. New challenges arise in large-scale proteomic profiling when dealing with complex biological mixtures. Nevertheless, oncoproteomics offers great promise for unveiling the complex molecular events of tumorigenesis, as well as those that control clinically important tumor behaviors, such as metastasis, invasion and resistance to therapy. In this review, the development and advancement of oncoproteomics technologies for cancer research in recent years are expounded.  相似文献   

9.
In recent years, the world energy demands have had a recurrent increase. For this reason the alternative to the fossil fuel resources are trend topics in investigation. Microalgae have been extensively studied as a source of biofuels and as one of the most promising alternatives in this new framework. One of the possibilities of obtaining renewable energy from microalgae is biogas production using anaerobic digestion process. This process is considered a significant component for biofuels and waste management, since represent an opportunity for energy generation using different wastewater products; also, the economic viability of microalgae liquid biofuel production could be improved. However, the anaerobic digestion of microalgae biomass is still not optimized because of the numerous technical limitations such as the microalgae characteristics, low carbon:nitrogen ratio, ammonia toxicity and even salinity. The present review summarizes and compares information concerning to anaerobic digestion of microalgal biomass and future directions for research. Besides, specific operational factors and potential inhibitory parameters of the process are analyzed and compared. Additionally, the paper covers the state or art concerning in methane production enhancement from algal biomass.  相似文献   

10.
With advances in ionization methods and instrumentation, liquid chromatography (LC)/mass spectrometry (MS) has become a powerful technology for protein characterization. This review article will describe the general approaches on LC-MS analysis in protein characterization, including bottom-up and top-down strategies. Discussions will be given on characterization of recombinant proteins, and post-translational and protein modifications such as disulfide bonds, glycosylation and phosphorylation using LC-MS. New research directions in this area will also be presented to illustrate future prospects of LC-MS in protein characterization, including application to proteomics.  相似文献   

11.
With advances in ionization methods and instrumentation, liquid chromatography (LC)/mass spectrometry (MS) has become a powerful technology for protein characterization. This review article will describe the general approaches on LC-MS analysis in protein characterization, including bottom-up and top-down strategies. Discussions will be given on characterization of recombinant proteins, and post-translational and protein modifications such as disulfide bonds, glycosylation and phosphorylation using LC-MS. New research directions in this area will also be presented to illustrate future prospects of LC-MS in protein characterization, including application to proteomics.  相似文献   

12.
近红外光学成像技术及其在神经科学中的应用   总被引:1,自引:0,他引:1  
近红外光学成像技术是近年发展起来的一种动态检测脑功能的方法。采用这种技术可以测量在脑活动时氧合血红蛋白、脱氧血红蛋白和细胞色素氧化酶等的变化,同时得到与刺激相关的细胞内和细胞外活动的改变。近红外光学成像技术的时间分辨率较高,并具有简便易行、价格低廉和无损伤性等特点,有望可以同时检测神经元活动、能量代谢以有血液动力学的变化。目前它已作为检验功能性磁共振成像原理的一种方法,并在认知神经科学和医学等的研究中得到越来越广泛的应用。  相似文献   

13.
Vaccine adjuvants: current state and future trends   总被引:14,自引:0,他引:14  
The problem with pure recombinant or synthetic antigens used in modern day vaccines is that they are generally far less immunogenic than older style live or killed whole organism vaccines. This has created a major need for improved and more powerful adjuvants for use in these vaccines. With few exceptions, alum remains the sole adjuvant approved for human use in the majority of countries worldwide. Although alum is able to induce a good antibody (Th2) response, it has little capacity to stimulate cellular (Th1) immune responses which are so important for protection against many pathogens. In addition, alum has the potential to cause severe local and systemic side-effects including sterile abscesses, eosinophilia and myofascitis, although fortunately most of the more serious side-effects are relatively rare. There is also community concern regarding the possible role of aluminium in neurodegenerative diseases such as Alzheimer's disease. Consequently, there is a major unmet need for safer and more effective adjuvants suitable for human use. In particular, there is demand for safe and non-toxic adjuvants able to stimulate cellular (Th1) immunity. Other needs in light of new vaccine technologies are adjuvants suitable for use with mucosally-delivered vaccines, DNA vaccines, cancer and autoimmunity vaccines. Each of these areas are highly specialized with their own unique needs in respect of suitable adjuvant technology. This paper reviews the state of the art in the adjuvant field, explores future directions of adjuvant development and finally examines some of the impediments and barriers to development and registration of new human adjuvants.  相似文献   

14.
The metabolome is characterized by a large number of molecules exhibiting a high diversity of chemical structures and abundances, requiring complementary analytical platforms to reach its extensive coverage. Among them, atmospheric pressure ionization mass spectrometry (API-MS)-based technologies, and especially those using electrospray ionization are now very popular. In this context, this review deals with strengths, limitations and future trends in the identification of signals highlighted by API-MS-based metabolomics. It covers the identification process from the determination of the molecular mass and/or its elemental composition to the confirmation of structural hypotheses. Furthermore, some tools that were developed in order to address the MS signal redundancy and some approaches that could facilitate identification by improving the visualization and organization of complex data sets are also reported and discussed.  相似文献   

15.
Testosterone and estradiol assays: current and future trends   总被引:1,自引:0,他引:1  
Demers LM 《Steroids》2008,73(13):1333-1338
Sex steroid measurements for the investigation of endocrine disorders have been fraught with accuracy and imprecision problems since the advent of high throughput, direct assays almost 10 years ago on automated analyzers. Results from testosterone and estradiol measurements at the low end of detectability have suffered the most and there are few automated systems that can accurately measure these steroids in women, children and hypogonadal males on a routine basis. With the advent of mass spectrometry coupled to either gas chromatography or liquid chromatography, an improved approach to the measurement of these steroids has developed that shows promise for accurately and precisely measuring testosterone and estradiol in all patient populations including women and children. These mass spectrometry based methods for the sex steroids have been established as higher order reference method procedures that will resolve the issues of low end sensitivity measurements for these steroids, provide for appropriate standardization and reference materials and align most laboratories in hospital and reference laboratories to generate results that are inter-changeable between laboratories and methods.  相似文献   

16.
Coronary atherosclerosis: current therapeutic approaches and future trends   总被引:1,自引:0,他引:1  
F V DeFeudis 《Life sciences》1991,49(10):689-705
Invasive cardiovascular procedures, such as percutaneous translumenal coronary angioplasty (PTCA) and aorto-coronary bypass surgery (ACBS), that are currently employed in treating the coronary stenosis or occlusion caused by atherosclerosis represent a major therapeutic advance for managing coronary heart disease (CHD). However, the cellular proliferative response and associated intimal hyperplasia that can follow the damage to blood vessels that occurs with these procedures leads to late complications which cannot be effectively controlled by presently available drugs. Hence, a new approach is required for managing these complications, termed "restenosis" (in the case of PTCA) or "stenosis" (in the case of ACBS). Existing drug therapy is reviewed and some new approaches to this problem are provided herein. Further studies of growth factors and other substances that influence the cellular proliferative response that follows injury to the blood vessel wall could lead to the development of effective therapy. Inhibition of intimal hyperplasia and/or acceleration of endothelial cell re-growth provide a basis for such new approaches. Platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF), as well as endothelium-derived relaxing factor(s) (EDRF) and calcitonin gene-related peptide (CGRP) are among the substances discussed. Modification of certain currently available drugs (e.g. Ca(2+)-antagonists) could also be of value in meeting this therapeutic demand.  相似文献   

17.
Gene therapy is a hope for curing many diseases and pathological conditions which are relatively difficult to treat. However lack of proper gene delivery vehicle is the main limiting step in this direction. Though viral vectors still lead as the major vehicle used in gene therapy clinical trials, their immunogenicity and low capacity restrict their wide use. Hence there is a need for developing non-viral vectors which can really be used for clinical applications. Polymers are a versatile group of molecules which can be modified and designed or engineered according to the end needs of the applications. The objective of this review is to summarize the recent advances in the development of polymeric vectors for gene delivery applications reported in patents and scientific journals.  相似文献   

18.
Melanins are enigmatic pigments that are produced by a wide variety of microorganisms including several species of bacteria and fungi. Melanins are biological macromolecules with multiple important functions, yet their structures are not well understood. Melanins are frequently used in medicine, pharmacology, and cosmetics preparations. Melanins also have great application potential in agriculture industry. They have several biological functions including photoprotection, thermoregulation, action as free radical sinks, cation chelators, and antibiotics. Plants and insects incorporate melanins as cell wall and cuticle strengtheners, respectively. Actinobacteria are the most economically as well as biotechnologically valuable prokaryotes. However, the melanin properties are, in general, poorly understood. In this review an evaluation is made on the present state of research on actinobacterial melanins and its perspectives. The highlights include the production and biotechnological applications of melanins in agriculture, food, cosmetic and medicinal fields. With increasing advancement in science and technology, there would be greater demands in the future for melanins produced by actinobacteria from various sources.  相似文献   

19.
20.
The U.S. government does not yet have the range of medical countermeasures needed to protect its citizens from anthrax and other potential bioweapons. In the event of an anthrax attack, treatment interventions in addition to antibiotics would be needed so that very ill patients can be treated and clean-up crews can be better protected, especially if an engineered strain is used. This article describes specific anthrax countermeasures that are in development, barriers to development, and potential mechanisms the government could use to accelerate the movement of these countermeasures through the pipeline. A key challenge will be to encourage the transition of promising leads from basic research to the product development stage, when they may qualify for BioShield funds.  相似文献   

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