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   572篇
  免费   24篇
  国内免费   1篇
耳鼻咽喉   4篇
儿科学   27篇
妇产科学   6篇
基础医学   66篇
口腔科学   61篇
临床医学   45篇
内科学   118篇
皮肤病学   8篇
神经病学   32篇
特种医学   138篇
外科学   19篇
综合类   12篇
预防医学   26篇
眼科学   5篇
药学   17篇
  1篇
肿瘤学   12篇
  2021年   7篇
  2020年   5篇
  2016年   13篇
  2015年   18篇
  2014年   11篇
  2013年   8篇
  2012年   18篇
  2011年   24篇
  2010年   12篇
  2009年   9篇
  2008年   24篇
  2007年   17篇
  2006年   26篇
  2005年   15篇
  2004年   23篇
  2003年   10篇
  2002年   10篇
  2001年   10篇
  2000年   8篇
  1999年   6篇
  1998年   19篇
  1997年   26篇
  1996年   21篇
  1995年   20篇
  1994年   14篇
  1993年   13篇
  1992年   4篇
  1991年   8篇
  1990年   7篇
  1989年   15篇
  1988年   22篇
  1987年   16篇
  1986年   18篇
  1985年   12篇
  1983年   5篇
  1981年   9篇
  1979年   4篇
  1978年   6篇
  1975年   3篇
  1974年   4篇
  1972年   3篇
  1971年   4篇
  1967年   6篇
  1966年   5篇
  1961年   3篇
  1959年   4篇
  1958年   4篇
  1957年   3篇
  1956年   4篇
  1954年   4篇
排序方式: 共有597条查询结果,搜索用时 0 毫秒
71.
A rapid, simple and efficient method for selecting living spermatozoa for intracytoplasmic sperm injection (ICSI) in cases with total lack of sperm movement is described. The selection is based on a characteristic deformation of living spermatozoa exposed to hypo-osmotic conditions during short sequential exposures to modified culture medium and polyvinylpyrrolidone solution; the osmolarity of both of these solutions is reduced by one half by diluting them with an equal amount of water. The application of the sperm viability selection step in six ICSI treatment cycles with total absence of sperm movement resulted in a fertilization rate of 41.9% and the establishment of two ongoing clinical pregnancies. The method described for the selection of living spermatozoa makes it possible to reach acceptable fertilization rates and to obtain ongoing pregnancies by ICSI in cases with total lack of sperm movement. Because of its simplicity, this method can easily be improvised when the total lack of sperm movement is an unexpected finding made on the day of the planned ICSI.   相似文献   
72.
We describe a G-->A transition within intron 5 of the NF2 gene. This mutation creates a consensus splice branch point sequence. To our knowledge this is the first report of a mutation that creates a functional branch point sequence in a human hereditary disorder. The new branch point sequence is located 18 bp upstream of a consensus splice acceptor site. A consensus splice donor site is found 106 bp 3' of the acceptor site. Asa consequence the G-->A transition results in an alternatively spliced mRNA containing an additional exon 5a of 106 bp derived from intron sequences. We cloned the mutant cDNA and show that due to an in-frame stop codon the cDNA codes for a truncated NF2 protein. The mutation was observed in three affected members of an NF2 family. In a tumour of one of the family members both alternatively spliced and wild-type mRNA were found, although the wild-type allele of the gene is absent due to an interstitial deletion on chromosome 22. We also show that immunoprecipitations reveal the presence of full-length wild-type NF2 protein in the tumour lysate. These data support the hypothesis that some degree of normal splicing of the mutant precursor RNA is taking place. It is therefore likely that this residual activity of the mutant allele explains the relatively mild phenotype in the family. These data also indicate that complete inactivation of the gene is not required for tumour formation.   相似文献   
73.
74.
75.
Abstract. Recurrent diarrhoea and weight loss in many adult patients with Down's syndrome (DS), initiated a search for malabsorption based on determination of serum IgG and IgA antibody levels to dietary antigens. The results were compared with measurements of autoantibodies and serum zinc levels. DS patients had increased IgG and IgA activities to gluten proteins, casein and ovalbumin compared with an age- and sex-matched group of other mentally retarded patients in the same institution. Intestinal biopsy was performed in six of the 38 patients; one had total and one partial villous atrophy. Serum zinc was significantly lower in DS patients (median 14.7 μmol/l, range 5.5–20 μmol/l) than in the controls (median 16.4 μmol/l, range 12.7–19.5 μmol/l). DS patients with increased IgA activity to gluten weighed less and had lower concentrations of zinc in serum than DS patients with normal IgA activity. Twenty-eight per cent of the DS patients had autoantibodies to the thyroid gland. Our results suggest intestinal malfunction in DS, perhaps related to a defect of immune regulation caused by reduced levels of zinc in serum.  相似文献   
76.
77.
78.
OBJECTIVE: Our goal was to report a case of malignant neuroleptic syndrome in a patient administered with both oxcarbazepine (OXCBZ) and amisulpride (AM). METHOD: We present a case of a young man who presented with symptoms of malignant neuroleptic syndrome after progressive titration of OXCBZ (1200 mg) added to the long-term treatment with AM (800 mg). RESULTS: After discontinuation of AM and administration of dopaminergic drugs, his clinical symptoms improved gradually. CONCLUSION: This case suggests that clinicians should consider the risk of neuroleptic malignant syndrome when OXCBZ is coadministered to patients undergoing long-term treatment with neuroleptics.  相似文献   
79.
80.
Abdominal radiography, excretory urography, retrograde pyelography, and computed tomography were performed in two patients who had undergone retrograde pyelography with thorium dioxide (Thorotrast) approximately 40 years ago. Both patients developed a transitional cell carcinoma due to suburothelial thorium deposition. Typical thorium densities were demonstrated at CT in the peripelvicalyceal area as well as in retroperitoneal lymph nodes. Elderly patients in whom radiographic examination reveals retained Thorotrast in the kidney should be followed up because of the high risk of renal carcinoma.  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