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 共查询到20条相似文献,搜索用时 31 毫秒
1.
Search for teratogenic risks with the aid of malformation registries   总被引:6,自引:0,他引:6  
B K?llén 《Teratology》1987,35(1):47-52
A summary is given of experiences in the use of the Swedish registries of birth defects for causal epidemiological studies. Case-control studies and cohort studies are described and exemplified. The application of case-control techniques to cohorts of women selected for probable or possible exposure is also described. The importance of using large-scale registry studies in the search for common but low-risk teratogens is stressed.  相似文献   

2.
S Jacob  S Poddar 《Acta anatomica》1986,125(4):268-273
The gross anatomy, histology and histochemistry of the ferret prostate is described. The structure and course of the prostatic urethra and the ductus deferentes are also described. The prostate is the only accessory reproductive gland present in the ferret. The prostate consists of tubuloalveolar glands surrounded by fibromuscular connective tissue. Histochemical studies showed that the glandular parenchyma contained large amounts of sialidase-labile sialomucin as well as acid phosphatase and small quantities of alkaline phosphatase and proteins. The findings in this study are discussed in relation to similar studies in other animals and man.  相似文献   

3.
A computer system is described which stores patient data relating to clinical pharmacokinetic assessments made by clinical pharmacists, who are participating in a clinical pharmacokinetics service. The system was developed to assist in the documentation of service activities and storage of patients' pharmacokinetic data. An additional component of the system is the ability for retrospective review of the stored data. Applications of this system to the derivation of new information on drug pharmacokinetics and drug efficacy/toxicity in various patient groups is discussed. The implications for Phase IV drug studies and toxicity screening studies is also described.  相似文献   

4.
羟基磷灰石复合材料的研究进展   总被引:1,自引:0,他引:1  
目的:本文综述了羟基磷灰石(HA)复合材料的最新进展和研究近况,并简略探讨了它们的今后发展方向。  相似文献   

5.
Extended performance using a high field magnet mass spectrometer   总被引:1,自引:0,他引:1  
The development of a high field magnet for high mass electron impact, chemical ionization, field desorption and fast atom bombardment mass spectrometric studies is described. Its utility is illustrated with examples from structural studies of vitamin B12 biosynthetic intermediates, oligosaccharides, glycopeptides and the bleomycin antibiotics. The technique has also greatly assisted sequence studies of protein derived peptides.  相似文献   

6.
A review is presented of some methods used to prepare cytologic specimens for analytical and/or automated studies, with the steps of the procedures detailed in appendices. The preparation of the cell monolayers required for optimal automated cell image analysis and classification, e.g., by the Cytoscan 110, is discussed, as is the preparation of poly-L-lysine-coated slides used in the production of monolayered specimens. These monolayers, which can be prepared from a variety of specimens, are also useful for cytochemical and immunocytochemical studies and DNA ploidy analysis. For DNA analysis, a modified gallocyanin chrome alum staining procedure is described as a stoichiometric alternative to the time-consuming Feulgen reaction. The hydrolysis technique required by the latter method is also detailed. The freeze-fracturing technique for the enhancement of monoclonal antibody immunocytochemical staining of detectable antigens is described, along with an indirect immunoalkaline phosphatase staining method. The use of enzyme cytochemical reactions for glucose 6 phosphate dehydrogenase and lysosomal naphthylamidase is also presented.  相似文献   

7.
A case of biphasic synovial sarcoma initially diagnosed by fine needle aspiration cytology is described. The diagnosis was confirmed by electron microscopic studies on a repeat aspirate and histologic and immunohistochemical studies on the surgical specimen. The cellular DNA content was also measured. The differential diagnosis and histogenesis of this neoplasm are discussed.  相似文献   

8.
The genus Marphysa is widely collected for bait by recreational fishermen in Australia, and yet the number of species remains unresolved. A new species is described together with additional information on a previously described species. This study reveals that while species of Marphysa superficially resemble one another, detailed studies on the distribution of different types of chaetae along the body, together with molecular studies, uncover species which may co‐occur. Correct identification is critical for management of these largely intertidal species. This study also highlights the increasing awareness of the presence of pseudo‐cryptic species in polychaetes.  相似文献   

9.
Following a previous paper which described the characteristics of the various types of electronic ‘environmental meters’ for use in schools this paper aims to give a more critical review of the instruments available. Chemical test papers and kits for use in environmental studies are also described.  相似文献   

10.
Two-base DNA hairpin-loop structures in vivo.   总被引:4,自引:2,他引:2       下载免费PDF全文
In vitro studies have revealed that DNA hairpin-loops usually contain four unpaired bases. However, a small subset of sequences can form two-base loops. We have previously described an in vivo assay that is sensitive to tight loop formation and have set out to test whether DNA sequences known to form two-base loops in vitro also form tight loops in vivo. It is shown that the sequences 5'dCNNG and 5'dTNNA behave as predicted if they favour two-base loop formation in vivo, a result that is consistent with previously described in vitro studies. The ability of specific DNA sequences to form tight loops in vivo has implications for their potential to form transient structures involved in gene regulation, recombination and mutagenesis.  相似文献   

11.
The application of photoactivatable derivatives for studies of different types of neuroreceptors belonging to two superfamilies, G-protein-dependent receptors and ligand-gated ionic channels, is discussed. Studies of the structure of voltage-gated and ion-gated channels with the use of specific photoactivatable derivatives of neurotoxins are also described. Possibilities and prospects for the application of photoactivatable ligands in studies of the spatial structure of neuroreceptors are reviewed.  相似文献   

12.
Computer programs are described that direct the collection, processing, and graphical display of numerical data obtained from high resolution thermal denaturation (1-3) and circular dichroism (4) studies. Besides these specific applications, the programs may also be useful, either directly or as programming models, in other types of spectrophotometric studies employing computers, programming languages, or instruments similar to those described here (see Materials and Methods).  相似文献   

13.
A new method of quantitative evaluation and comparison for bone tissue histological studies is described. Optical diffractometry allows numerical evaluation of dimensions of structures being studied and also permits study by discriminant analysis.  相似文献   

14.
The application of photoactivatable derivatives for studies of different types of neuroreceptors belonging to two superfamilies, G-protein dependent receptors and ligand-gated ionic channels, is discussed. Studies of the structure of voltage-gated and ion-gated channels with the use of specific photoactivatable derivatives of neurotoxins are also described. Possibilities and prospects for the application of photoactivatable ligands in studies of the spatial structure of neuroreceptors are reviewed.  相似文献   

15.
Thirty-five new fossil hominid specimens are described. They were recovered from the Plio-Pleistocene sediments to the east of Lake Turkana (formerly Lake Rudolf). They include cranial and mandibular parts, teeth, and postcranial bones of upper and lower limbs. Parts of a single skeleton are also described. All of the specimens are described in anatomical detail and selected measurements are given. Some of the specimens are illustrated. It is proposed that they should be attributed to the family Hominidae, with genus and species undetermined until detailed comparative studies have been undertaken.  相似文献   

16.
Clinical cancer studies are increasing in sophistication and computerisation of data and statistical analysis is often required. The system described uses a Hewlett Packard 9845S microprocessor-based desk top computer to store clinical data in a form interpretable to the clinician but also immediately usable in statistics packages. This flexible combination has meant improved management of clinical studies with faster analysis and closer control of toxicity data and protocol irregularities.  相似文献   

17.
Abstract. The structure of chloroplast membrane proteins and their organization into photosynthetically-active multimeric complexes is described. Extensive use has been made of information derived from gene sequencing and other biochemical studies to predict likely protein conformations. These predictions have been assimilated into structural models of the various thylakoid complexes. The enzymatic activities of the complexes have also been described and where possible related to individual polypeptides.  相似文献   

18.
An analysis and a comparison of the methods of geometric morphometrics as applied to fish species identification and to studies on the population structure of fish stocks based on peculiarities of the otolith shape are performed. A review of the geometric morphometric methods used in studies on fish otoliths is provided. The results of our own research on possible utilization of elliptical Fourier analysis for species identification are also described.  相似文献   

19.
An outline is given of the theoretical approaches that have been made to understand and describe the electronic energy band structures for polynucleotides such as DNA and RNA. The possible relevance of such studies to cancer research is also briefly described.  相似文献   

20.
An automatic method for the measurement of trypsic activity in studies of zooplankton proteolytic digestion is described. Modifications of amylase and protein determinations previously published as indices of herbivorous digestion and of biomass, are given. Up to 40 samples can be analysed within one hour with an improved level of sensitivity. These methods are well adapted for studying very small numbers of zooplankton organisms and give reproducible results. Equivalent manual methods are also described.  相似文献   

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