首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   44篇
  免费   3篇
妇产科学   1篇
基础医学   12篇
口腔科学   16篇
内科学   6篇
皮肤病学   2篇
神经病学   1篇
外科学   2篇
预防医学   2篇
肿瘤学   5篇
  2017年   1篇
  2016年   1篇
  2012年   2篇
  2011年   1篇
  2010年   1篇
  2009年   1篇
  2008年   3篇
  2007年   5篇
  2006年   3篇
  2005年   2篇
  2004年   2篇
  2002年   1篇
  2001年   2篇
  2000年   2篇
  1999年   1篇
  1998年   1篇
  1996年   1篇
  1995年   2篇
  1992年   1篇
  1990年   3篇
  1988年   4篇
  1987年   2篇
  1986年   3篇
  1985年   1篇
  1979年   1篇
排序方式: 共有47条查询结果,搜索用时 0 毫秒
1.
Loss of heterozygosity (LOH) on chromosomes 3p and 9p has been documented in a variety of malignancies, which suggests the presence of tumor suppressor gene loci on these chromosomes. We have studied 77 oral carcinomas for LOH using 16 microsatellite markers distributed over 5 human chromosomes. Fifty-five (71%) of these tumors showed LOH at one or more loci. A significant proportion of LOH at the informative tumors was observed at chromosomes 3p and 9p: 58% and 48%, respectively. A majority of the tumors showed losses at multiple loci on chromosomes 3p or 9p or on both. Our results suggest that tumor suppressor genes located on the short arms of chromosomes 3 and 9 may be involved in the pathogenesis of oral carcinoma. These regions of deletion observed in oral cancers overlap those reported in other neoplasms. However, we did not find any evidence of these changes in tumor margins with early pathological changes. © 1996 Wiley-Liss, Inc.  相似文献   
2.
Since the 1960s, childbirth education advocates have attempted to persuade pregnant women that educational preparation for labor and birth is an essential component of the transition to motherhood. Initially, pregnant women who were seeking unmedicated births as a refuge from the inhumane childbirth treatments of the mid‐20th century embraced this view. However, with the changing childbirth climate, including a growing preference for medicated birth, scheduled inductions, and cesarean sections, attendance has diminished and childbirth education finds itself at a crossroads. Commonly used childbirth education models/organizations and several new emerging models along with the available research literature and recommendations for clinical practice and research are presented.  相似文献   
3.
Generalized genomic instability, detected as somatic changes in allele sizes at microsatellite loci in tumors compared to peripheral lymphocyte DNA, is a recently recognized mechanism of mutation in cancer. Such instability results from the Somatic loss of DNA mismatch repair capability. Germ-line mutations at DNA mismatch repair loci confer susceptibility to colon cancer in hereditary non-polyposis colorectal cancer. Somatic loss of DNA mismatch repair has been reported in a large variety of other tumor types. Our goal was to determine the frequency of microsatellite instability in a large series of oral tumors. Out of 91 tumors analyzed for microsatellite instability, 6 (7%) showed microsatellite instability. Instability was observed at multiple loci with a range of 50-74% of loci affected. Alterations include both increase (74%) and decrease (26%) in allele sizes. The proportion of alleles affected ranged from 30-58% of all alleles. Our data suggest that somatic genomic instability plays a role in the pathogenesis of a small subset of oral tumors. © 1995 Wiley-Liss, Inc.  相似文献   
4.
Congruence of molecules and morphology using a narrow allometric approach   总被引:3,自引:0,他引:3  
There are many cases of incongruence between phylogenetic hypotheses produced from morphological data and those produced from molecular data. In such instances, many researchers prefer to accept the results of molecular phylogenies. For example, in a recent analysis of primate phylogenies based on craniodental characters, Collard and Wood [Collard M, Wood BA (2000) Proc Natl Acad Sci USA 97:5003-5006] argued that, because craniodental data do not yield relationships concordant with molecular studies, the results of studies that employ such characters must be considered suspect. As most of our knowledge of mammalian evolution and phylogenetic history comes from craniodental fossils, these results have dramatic implications. However, the aforementioned analysis did not take into account the potentially confounding effects of allometry on quantitative craniodental characters. In this article, we employ a previously undescribed narrow allometric coding method that accounts for such confounding influences in phylogenetic analyses of craniodental morphology. By using essentially the same raw data set as Collard and Wood [Collard M, Wood BA (2000) Proc Natl Acad Sci USA 97:5003-5006], 65 quantitative craniodental characters were adjusted in a parsimony analysis for the primate tribe Papionini, a group of monkeys argued to display extensive homoplasy. The resulting phylogenetic tree was congruent with the phylogenetic tree based on molecular data for these species, thereby meeting the "criterion of congruence." These results suggest that morphological data, when treated properly, can be considered as reliable as molecular data in phylogenetic reconstruction. Rather than accepting phylogenetic hypotheses from one data source over another, cases of incongruence should be examined with greater scrutiny.  相似文献   
5.
An intracellular pool of Na channel alpha subunits has been detected in developing brain cells in vivo and in vitro by phosphorylation with cAMP-dependent protein kinase, immunoprecipitation with specific antiserum, and NaDodSO4 gel electrophoresis or by radioimmunoassay. These alpha subunits are membrane-bound, contain complex carbohydrate chains, and have an apparent molecular weight of 260,000 like mature alpha subunits. In contrast to mature alpha subunits, the intracellular subunits are not covalently attached to a beta 2 subunit, and they do not bind saxitoxin with high affinity. They comprise 67-77% of the total immunoreactive alpha subunit in developing rat brain cells but are not a prominent component in the adult brain. It is proposed that this intracellular pool of alpha subunits forms a ready reserve of preformed subunits for incorporation into the surface membrane during periods of active membrane biogenesis. The results suggest that disulfide linkage of the alpha and beta 2 subunits, insertion into the cell surface membrane, and attainment of a functional conformation are closely related late events in the biogenesis of the Na channel. These processes may regulate the number of functional Na channels in the developing brain.  相似文献   
6.
Serum antibodies recognizing the Golgi apparatus have been reported in patients with connective tissue diseases, but little is known of their significance. Serum from a systemic lupus erythematosus patient with polymyositis was found to have high titers of anti-Golgi apparatus antibody. This serum recognized a 64 kD polypeptide in immunoblotting with HEp-2 cells. To verify that the 64 kD polypeptide was associated with the Golgi apparatus and to characterize which Golgi component was recognized, a monoclonal antibody was produced. IgG, isolated from this serum, was used in affinity chromatography to produce purified material which was used to generate a mouse monoclonal antibody. The monoclonal antibody had an indirect immunofluorescent pattern identical to that produced by the patient's serum, and similarly recognized a 64kD polypeptide in immunoblotting. A 59 kD polypeptide was also recognized by the monoclonal antibody, suggesting that the antigens recognized by the monoclonal and serum antibodies may be only partially identical. The antigen appears to be a glycoprotein and an integral component of the Golgi cisternae membranes.  相似文献   
7.
The nasal cavity of strepsirrhine primates (lemurs and lorises) has the most primitive arrangement of extant primates. In nocturnal species, the numerous turbinals of the ethmoid bear a large surface area of olfactory mucosa (OM). In this study, we examine turbinal development in four genera of diurnal or cathemeral lemuriformes. In addition, we examined an age series of each genus to detect whether structures bearing OM as opposed to respiratory mucosa (RM) develop differently, as has been observed in nocturnal strepsirrhines. In adults, the maxilloturbinal is covered by highly vascular respiratory mucosa throughout its entire length, with large sinusoidal vessels in the lamina propria; any parts of other turbinals that closely borders the maxilloturbinal has a similar mucosa. Posteriorly, the most vascular RM is restricted in the nasopharyngeal duct, which becomes partitioned from the dorsal olfactory region. A comparison of newborns to adults reveals that the first ethmoturbinal increases more in length in the parts that are covered with RM than OM, which supports the idea that ethmoturbinals can specialize in more than one function. Finally, we observe that the regions of turbinals that are ultimately covered with RM develop more accessory lamellae or additional surface area of existing scrolls compared to the regions covered with OM. Because such outgrowths of bone develop postnatally and without cartilaginous precursors, we hypothesize that the complexity of olfactory lamellae within the ethmoturbinal complex is primarily established at birth, while respiratory lamellae become elaborated due to the epigenetic influence of respiratory physiology. Anat Rec, 299:1492–1510, 2016. © 2016 Wiley Periodicals, Inc.  相似文献   
8.
BACKGROUND: The periodontal disease status of 320 dentate adults, diagnosed 23.7 years previously with Type 1 insulin dependent diabetes mellitus, was evaluated. These patients had been monitored at 2-year intervals as part of a large University of Pittsburgh longitudinal study assessing the medical complications associated with insulin dependent diabetes. METHODS: During one of their regularly scheduled medical examinations, a group of 320 adult dentate subjects (mean age of 32.1 years) received a periodontal examination as part of a comprehensive oral health assessment. The oral health assessment collected data regarding demographics, oral health behaviors, tooth loss, coronal and root caries, salivary functions, and soft tissue pathologies. For the periodontal assessments, 3 facial sites (mesial, midcervical, distal) of the teeth in the right maxillary/left mandibular or left maxillary/right mandibular quadrants were evaluated for calculus, bleeding on probing (BOP) and loss of gingival attachment (LOA). RESULTS: Attachment loss was significantly greater for older patients whereas BOP and calculus levels were relatively constant across age categories. Univariate analyses of factors possibly related to extensive periodontal disease (LOA > or =4 mm for at least 10% of sites examined) indicated an association with older age; lower income and education; past and current cigarette smoking; infrequent visits to the dentist; tooth brushing less than once per day; older age of onset; longer duration of diabetes; and the diabetic complication of neuropathy. A multivariate regression model of all possibly significant factors found current cigarette use (odds ratio [OR] = 9.73), insulin dependent diabetes onset after 8.4 years of age (OR = 3.36), and age greater than 32 years (OR = 3.00) explained the majority of the extensive periodontal disease in this group of diabetic patients. CONCLUSIONS: Management and prevention of extensive periodontal disease for Type 1 diabetic patients should include strong recommendations to discontinue cigarette smoking.  相似文献   
9.
Objectives: The purpose of this study was to assess potential risk factors for the development of poor oral hygiene and increased dental caries in individuals with scleroderma. Methods: Twenty‐two subjects with scleroderma participated in this study. All subjects were examined with the Patient Hygiene Performance (PHP) Index, which assesses the extent of plaque and debris over a tooth surface. In addition, oral aperature, xerostomia and dominant upper extremity strength, motion, skin thickness, and dexterity were measured. Results: None of the subjects had good or excellent hygiene. Fifteen subjects had fair oral hygiene and seven subjects had poor oral hygiene as measured by the PHP Index. Significant differences were seen between these two groups for oral aperture, percentage of teeth with caries, skin thickness, dexterity and finger flexion. Dexterity and joint motion correlated significantly with the number of decayed surfaces and number of caries. Oral aperture correlated with the PHP Index and the number of dental caries. Conclusions: Subjects with poor oral hygiene required more time to complete manual dexterity task and had decreased hand strength and joint motion. Moreover, these same subjects had more contractures, scars, ulcers, and higher skin scores (more disease activity) than subjects in the fair hygiene group. In addition to frequent dental exam and routine cleaning, dental personnel may want to consider exercises to increase oral aperature and investigate toothbrush and dental floss selection used by persons with scleroderma.  相似文献   
10.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号