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1.
Abstract

Biosensors are useful analytical devices that can be integrated with on-line process monitoring schemes. In this article, the principles and applications of these devices for bioprocess monitoring are considered. Several different types of biosensors are described, and the applications and limitations of flow injection analysis (FIA) for these applications are discussed. It is hoped that the background provided here can be useful to researchers in this area.  相似文献   

2.
A statistical test for comparing several nucleotide sequences   总被引:2,自引:1,他引:1       下载免费PDF全文
A statistical test useful for the simultaneous comparison of nucleotide sequences is presented. A likelihood ratio test is derived, examples demonstrated, and tables of critical values are provided.  相似文献   

3.
Studies of platelet kinetics have provided useful information regarding the role of platelets in the pathogenesis of thrombosis and related disorders. Additionally, platelet survival studies have been useful in evaluating the efficacy of drugs that may be useful as platelet inhibitors. Many questions remain, however, and answers are needed before much of the kinetic data can be confidently applied to clinical problems in thrombosis.  相似文献   

4.
Metrichia cuniapiru, sp. n. (tribe Ochrotrichiini, family Hydroptilidae) from Misiones Province is described. Main characters useful for recognition of females of different species of Metrichia and keys for the males and larvae are provided. The pupa of M. neotropicalis is also described.  相似文献   

5.
MOTIVATION: The biological literature is a major repository of knowledge. Many biological databases draw much of their content from a careful curation of this literature. However, as the volume of literature increases, the burden of curation increases. Text mining may provide useful tools to assist in the curation process. To date, the lack of standards has made it impossible to determine whether text mining techniques are sufficiently mature to be useful. RESULTS: We report on a Challenge Evaluation task that we created for the Knowledge Discovery and Data Mining (KDD) Challenge Cup. We provided a training corpus of 862 articles consisting of journal articles curated in FlyBase, along with the associated lists of genes and gene products, as well as the relevant data fields from FlyBase. For the test, we provided a corpus of 213 new ('blind') articles; the 18 participating groups provided systems that flagged articles for curation, based on whether the article contained experimental evidence for gene expression products. We report on the evaluation results and describe the techniques used by the top performing groups.  相似文献   

6.
Examination of the plumage of Palaearctic warblers as migrants or wintering birds at Kampala, Uganda, provided useful material for a consideration of moult in relation to the timing of spring and autumn migration. Reasons are suggested for observed interspecific differences in the moult pattern, and for the variation reported from different wintering areas in the African continent.  相似文献   

7.
Tests (pupal covers) of twenty-eight species of male Coccidae, representing fifteen genera from America north of Mexico, are described and illustrated. Tests of each of the species exhibit morphological differences which are useful in identification. Terminology is given for the sutures, corresponding plates, and related structures of the generalized test and a key is provided for separation of the described species.  相似文献   

8.
9.
Eukaryotic cells are able to mount several genetically complex cellular responses to DNA damage. The yeast Saccharomyces cerevisiae is a genetically well characterized organism that is also amenable to molecular and biochemical studies. Hence, this organism has provided a useful and informative model for dissecting the biochemistry and molecular biology of DNA repair in eukaryotes.  相似文献   

10.
A marker locus closely linked to a disease locus is often useful for genetic counseling provided that a counselee is heterozygous at both disease and marker loci. Furthermore, the linkage phase of these genes in the counselee must be known. When the linkage between the disease and marker loci is very close, one often finds linkage disequilibrium between the loci. To evaluate the effect of such nonrandom associations on the utility of linked marker genes for genetic counseling, the proportion of informative families is studied for X-linked recessive and autosomal dominant diseases. This proportion is higher for X-linked genes than for autosomal genes, if other factors are the same. In general, codominant markers are more useful than dominant markers. Also, under appropriate conditions, the proportion of informative families is higher when linkage disequilibrium is present. The results obtained in this paper are useful for evaluating the utility of polymorphic restriction endonuclease cleavage sites as markers in genetic counseling.  相似文献   

11.
本文对2010—2015年全国口岸从美国进境松木中截获的齿小蠹进行了分析,分别对美云杉齿小蠹Ips borealis、美雕齿小蠹I.calligraphus、混点齿小蠹I.confusus、重齿小蠹I.duplicatus、南部松齿小蠹I.grandicollis、蒙大拿齿小蠹I.montanus、似混齿小蠹I.paraconfusus、白云杉齿小蠹I.perturbatus、美松齿小蠹I.pini、平额重齿小蠹I.plastographus、十二齿小蠹I.sexdentatus、云杉八齿小蠹I.typographus 12种昆虫的进境寄主进行统计,对截获频次进行分析对其成虫的主要形态特征进行了描述,编制了分种检索表,对检疫鉴定工作具有指导意义。  相似文献   

12.
D Ubben  R Schmitt 《Gene》1986,41(2-3):145-152
New derivatives of the tetracycline-resistance transposon Tn1721 that carry resistances to chloramphenicol, tetracycline, kanamycin and streptomycin are described. These elements are provided on various plasmid vehicles and as chromosomal insertions to extend the range of targets for Tn mutagenesis. Single EcoRI sites at the ends of these transposons proved most useful for physical mapping, for the generation of new EcoRI sites in cloning experiments, for end-labelling and for sequencing of DNA adjacent to an insertion.  相似文献   

13.
Explicit expressions are obtained which give quite accurate values for the effluent blood concentration for the model with axial mixing in tissue for the cases in which the initial capillary concentration is either zero or one. These simple expressions are useful since the formal solutions of Gosselin and Gosselin (1987,Bull. math. Biol 49, 329–349) are cumbersome to use. Reasonably accurate expressions are also provided for the model without axial mixing since the formal solution for the case in which the initial capillary concentration is zero (Gosselin and Gosselin, 1987) and for the case in which the initial concentration equals that of the tissue, the solution for which is provided here, require numerical integration.  相似文献   

14.
In a retrospective survey the results of a D-xylose absorption test have been assessed in relation to jejunal morphology and final diagnosis in 152 adult patients with various types of gastrointestinal disease. Neither urine excretion rates nor serum concentrations alone provide an adequate separation between patients with definite mucosal lesions and those without evidence of gut disease or with other types of gastrointestinal pathology.It is suggested that when a jejunal biopsy can readily be performed the xylose test serves little useful purpose in routine practice and can be positively misleading. It may still be useful as a screening test for referral for jejunal biopsy, provided that strict criteria of normality are applied.  相似文献   

15.
抗污损海洋天然产物的开发及其作用机理研究进展   总被引:2,自引:0,他引:2  
钱培元 《生命科学》2012,(9):1026-1034
首先对近年发表在学术期刊Biofouling上的一篇关于抗污损化合物的综述做一简短总结。其次,突出介绍了对无脊椎污损生物附着和变态分子水平的调控机制的研究近来的进展。旨在给那些从事生物污损和抗污损技术研究的科研人员提供一定的帮助。  相似文献   

16.
In Mexico informed consent is a legal requirement that ensures that patients who are invited to participate in clinical trials are provided with all the information needed to decide whether to participate, or not, in a research protocol. To improve our understanding of the problems physicians in developing countries encounter, when obtaining informed consent (IC), we examined their opinion on the importance of IC in clinical research, the quantity and quality of the information provided to the participant, and the conditions in which the IC is obtained. Investigators considered that IC was useful to the patients, providing information that helped the patient to make a decision about his/her participation. Nevertheless, they felt that for some aspects of the research, like drug development in general, the use of placebos, and the randomization process, many of the patients were not capable of fully understanding the information provided, referring to the complexity of the information and illiteracy as the main reasons. Many investigators were not acquainted with some of the guidelines established in the Mexican General Law of Health,(1) 36% of them admitting to not having completed their IC letters. Most investigators gave only minutes to the patient to make a decision and 20% of ICs were obtained while the patient was hospitalized. Except for one investigator, all of them considered that specific training in medical ethics would be useful for the daily clinical work.  相似文献   

17.
New drugs and technologies for cancer treatment are being developed at a rate that has created a reimbursement crisis. This article discusses third-party concerns about this problem and describes generic criteria that have proven to be useful in assessing any new technology. It is equally important to discontinue funding of ineffective and obsolete therapies as it is to devise a strategy for identifying and encouraging the development of new therapy that will be both clinically useful and cost-effective. Examples are provided to show that these are not necessarily mutually exclusive goals. Off-label application of standard therapy as well as the funding of new cancer therapy are considered. High-dose chemotherapy with autologous stem-cell support for treatment of a variety of neoplasms has become a major reimbursement challenge. Other technologies such as autolymphocyte therapy and use of colony-stimulating factors are considered in detail. Finally, a process for deciding how to fund new cancer therapy is described.  相似文献   

18.
An independent clinical trial of the Penn seroflocculation test for cancer was carried out in order to learn whether this test might be clinically useful either in differential diagnosis or as a screening test for the detection of cancer. In addition, studies were made of the flocculation titer of sera giving positive Penn tests. Incidental observations were made concerning the reproducibility of the test. The trial provided no evidence that the test might be useful in cancer detection. The test should be improved technologically before further clinical evaluations are undertaken. Further study of the basic mechanisms that bring about the positive Penn reaction appears desirable.  相似文献   

19.
A detailed analysis has been made of human renal biopsy tissue from thirteen subjects, judged to be "normal" by a variety of clinical tests. Analysis was made subjectively, and where possible by objective measurement, of routine diagnostic preparations, and of montages of entire glomeruli. Each approach provided useful information which had not been recorded before. Subjective examination was valuable only in the detection of glomerular changes that represent glomerular damage by their very presence of which are present in extreme degree. The random photography of material prepared for outline examination provided data for the quantitation of several glomerular constituents, and information concerning epithelial cell organelle content. Whole glomerular montages provided the opportunity to measure many more parameters of overall glomerular architecture. Comparisons were made, when possible, with the results of other workers.  相似文献   

20.
Mosses and liverworts, apart from peat provided by the former, have not been of significance in furnishing useful products. They are, however, of importance in the general economy of nature, and have been used in a variety of ways.  相似文献   

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