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   189篇
  免费   10篇
  国内免费   11篇
耳鼻咽喉   1篇
儿科学   8篇
妇产科学   6篇
基础医学   28篇
口腔科学   5篇
临床医学   15篇
内科学   56篇
皮肤病学   2篇
神经病学   7篇
特种医学   46篇
外科学   8篇
综合类   4篇
预防医学   4篇
眼科学   1篇
药学   10篇
中国医学   1篇
肿瘤学   8篇
  2022年   2篇
  2020年   2篇
  2018年   2篇
  2017年   3篇
  2016年   4篇
  2015年   5篇
  2014年   6篇
  2013年   3篇
  2012年   5篇
  2011年   4篇
  2010年   5篇
  2009年   5篇
  2008年   8篇
  2007年   6篇
  2006年   9篇
  2005年   1篇
  2004年   3篇
  2003年   3篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1998年   11篇
  1997年   12篇
  1996年   9篇
  1995年   6篇
  1994年   13篇
  1993年   12篇
  1991年   2篇
  1990年   2篇
  1989年   5篇
  1988年   5篇
  1987年   3篇
  1986年   5篇
  1985年   5篇
  1984年   6篇
  1983年   5篇
  1982年   5篇
  1981年   4篇
  1980年   6篇
  1979年   1篇
  1978年   1篇
  1977年   1篇
  1976年   3篇
  1975年   5篇
排序方式: 共有210条查询结果,搜索用时 0 毫秒
41.
A nonrandom translocation between chromosomes 3 and 21, t(3;21)(q26.2;q22) has been detected in patients with a myelodysplastic syndrome or acute myeloid leukemia after treatment (t-MDS/t-AML) for a primary malignant disease and in chronic myelogenous leukemia in blast crisis (CML-BC). In these patients, the breakpoint on chromosome 21 is at band 21q22. This band is also involved in the t(8;21)(q22;q22) detected in 40% of the patients with acute myeloid leukemia subtype M2 (AML-M2) de novo who have an abnormal karyotype. In the t(8;21), the AML1 gene is the site of the breakpoint on chromosome 21. The AML1 gene is transcribed from telomere to centromere, and in the t(8;21) the 5' part of AML1 is fused to the ETO gene on chromosome 8 to produce the chimeric AML1/ETO on the der(8) chromosome. We found that AML1 is also rearranged in two t-AML patients and in one CML-BC patient with the t(3;21), but the breakpoints are approximately 40 to 60 kb downstream to those of AML-M2 patients. This region contains at least one additional exon of AML1, as determined by using an AML1 cDNA as a probe in Southern blot analysis. The t(3;21) breakpoints for the remaining patients could not be determined because, by fluorescence in situ hybridization analysis, the breaks are outside of the region covered by the available probes.  相似文献   
42.
Hypercalcemia occurs in sarcoidosis because of 1,25‐dihydroxyvitamin D production by pulmonary alveolar macrophages. Long‐standing hypercalcemia and hypercalciuria may cause such complications as nephrocalcinosis, nephrolithiasis, and soft tissue calcification, which can be at least partially reversible with treatment. Here we present a 43‐year‐old African‐American man with diffuse soft tissue calcifications and acute kidney injury owing to sarcoidosis‐induced hypercalcemia, probably exacerbated by sun exposure and phosphorus intake in the form of dietary cola drinks. Soft tissue calcifications resolved and kidney function improved significantly with hydration and glucocorticoid therapy. We discuss the pathophysiology of the hypercalcemia of sarcoidosis and current treatment options. © 2010 American Society for Bone and Mineral Research  相似文献   
43.
There is a need recognized by the National Institute of Dental & Craniofacial Research and the National Cancer Institute to advance basic,translational and clinical saliva research. The goal of the Salivaomics Knowledge Base (SKB) is to create a data management system and web resource constructed to support human salivaomics research. To maximize the utility of the SKB for retrieval,integration and analysis of data,we have developed the Saliva Ontology and SDxMart. This article reviews the informatics advances in saliva diagnostics made possible by the Saliva Ontology and SDxMart.  相似文献   
44.
The emergence of the human brain is one of evolution's most compelling mysteries. With its singular importance and astounding complexity, understanding the forces that gave rise to the human brain is a major undertaking. Recently, the identification and publication of the complete genomic sequence of humans, mice, chimpanzees, and macaques has allowed for large-scale studies looking for the genic substrates of this natural selection. These investigations into positive selection, however, have generally produced incongruous results. Here we consider some of these studies and their differences in methodologies with an eye towards how they affect the results. We also clarify the strengths and weaknesses of each of these approaches and discuss how these can be synthesized to develop a more complete understanding of the genetic correlates behind the human brain and the selective events that have acted upon them.  相似文献   
45.
46.
With advances in genomic technologies, the amount of genetic data available to scientists today is vast. Genomes are now available or planned for 14 different primate species and complete resequencing of numerous human individuals from numerous populations is underway. Moreover, high‐throughput deep sequencing is quickly making whole genome efforts within the reach of single laboratories allowing for unprecedented studies. Comparative genetic approaches to the identification of the underlying basis of human brain, behavior, and cognitive ability are moving to the forefront. Two approaches predominate: inter‐species divergence comparisons and intra‐species polymorphism studies. These methodological differences are useful for different time scales of evolution and necessarily focus on different evolutionary events in the history of primate and hominin evolution. Inter‐species divergence is more useful in studying large scale primate, or hominoid, evolution whereas intra‐species polymorphism can be more illuminating of recent hominin evolution. These differences in methodological utility also extend to studies of differing genetic substrates; current divergence studies focus primarily on protein evolution whereas polymorphism studies are substrate ambivalent. Some of the issues inherent in these studies can be ameliorated by current sequencing capabilities whereas others remain intractable. New avenues are also being opened that allow for the incorporation of novel substrates and approaches. In the post‐genomic era, the study of human evolution, specifically as it relates to the brain, is becoming more complete focusing increasingly on the totality of the system and better conceptualizing the entirety of the genetic changes that have lead to the human phenotype today. Am. J. Hum. Biol., 2011. © 2010 Wiley‐Liss, Inc.  相似文献   
47.
1 肝素类药物的基本特性 1.1 肝素的化学性质肝素是天然氨基葡聚糖,由肥大细胞产生。药用的肝素由猪或牛的黏膜中提取。肝素由糖醛酸链和葡糖胺链交替组成, 含多少不等的硫酸根,相对分子质量5 ku~35 ku。现在使用  相似文献   
48.
Weinreb  JC; Brown  CE; Lowe  TW; Cohen  JM; Erdman  WA 《Radiology》1986,159(3):717-724
Sixteen pregnant patients with pelvic masses detected with ultrasound (US) were studied with magnetic resonance (MR) imaging at 0.35 T. Two patients were in their first trimester, eight in the second, and six in the last. On MR images, 34 masses were seen, including 19 uterine leiomyomas. With US, 20 masses were detected. All masses not seen with US were leiomyomas. Only 20 masses (in 11 patients) were removed for histologic study. In nine cases, MR imaging and US provided similar information on the origin, extent, and type of mass. In seven patients, MR imaging contributed additional information. MR imaging depicted more leiomyomas than US in three patients. In another case, MR images showed that a mass depicted with US was actually a loop of bowel. MR images allowed differentiation between a solid soft-tissue mass and a hemorrhagic fluid-containing mass, correctly depicted the presence of an abdominal pregnancy, and allowed evaluation of the parametrium for spread of cervical carcinoma.  相似文献   
49.
Hyperkalaemia is a potentially fatal disorder that demands direct treatment. The efficacy of traditional medical treatment is unpredictable, limited, of short duration or carries the risk of serious adverse events. The administration of salbutamol for hyperkalaemia in children is described in several clinical trials and case reports.

Conclusion: Salbutamol, inhaled or infused, is safe and efficacious and results in a predictable and long-lasting reduction in serum potassium. Salbutamol merits a place as the preferred medication for hyperkalaemia in children without arrhythmias. If follow-up with haemodialysis is required, the administration of salbutamol gives time to make the necessary preparations.  相似文献   
50.
OBJECTIVE: To determine the effect of nocturnal hypoglycaemia on sleep architecture in adolescents with insulin dependent diabetes mellitus (IDDM). DESIGN: 20 adolescents with IDDM (mean age 12.8 years, mean glycated haemoglobin (HbA1c) 8.9%) were studied on one night. Plasma glucose was measured every 30 minutes and cortisol and growth hormone levels every 60 minutes. Sleep was recorded using standard polysomnographic montages, and sleep architecture was analysed for total sleep time, stages 1-4, rapid eye movement, fragmentation, and arousals. RESULTS: Six subjects (30%) became hypoglycaemic (five subjects < 2.5 mmol/l), with one being symptomatic. There were no differences in age, HbA1c, duration of diabetes, or insulin regimen between hypoglycaemic and non-hypoglycaemic subjects. Hypoglycaemia was not predicted by glucose measurements before bed. There was no detectable rise in plasma cortisol or growth hormone concentrations during hypoglycaemia. Sleep architecture was not disturbed by nocturnal hypoglycaemia with no differences found in sleep stages, fragmentation, or arousals. CONCLUSIONS: Nocturnal hypoglycaemia is a common and usually asymptomatic complication of treatment in adolescents with IDDM. Moderate hypoglycaemia has not been shown to affect sleep architecture adversely. These findings are consistent with, and may explain, the observation that severe hypoglycaemia, with consequent seizure activity, is more common at night than during the day. Counterregulatory hormone responses to nocturnal hypoglycaemia may be less marked than with similar degrees of diurnal hypoglycaemia.  相似文献   
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