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   10904篇
  免费   990篇
  国内免费   50篇
耳鼻咽喉   83篇
儿科学   258篇
妇产科学   281篇
基础医学   1573篇
口腔科学   274篇
临床医学   1264篇
内科学   2545篇
皮肤病学   80篇
神经病学   811篇
特种医学   586篇
外科学   1279篇
综合类   187篇
一般理论   6篇
预防医学   1294篇
眼科学   107篇
药学   744篇
中国医学   5篇
肿瘤学   567篇
  2021年   141篇
  2020年   93篇
  2019年   146篇
  2018年   165篇
  2017年   100篇
  2016年   151篇
  2015年   159篇
  2014年   265篇
  2013年   335篇
  2012年   455篇
  2011年   531篇
  2010年   303篇
  2009年   256篇
  2008年   509篇
  2007年   486篇
  2006年   467篇
  2005年   446篇
  2004年   367篇
  2003年   354篇
  2002年   346篇
  2001年   324篇
  2000年   320篇
  1999年   302篇
  1998年   156篇
  1997年   131篇
  1996年   149篇
  1995年   121篇
  1994年   120篇
  1993年   92篇
  1992年   274篇
  1991年   253篇
  1990年   251篇
  1989年   258篇
  1988年   251篇
  1987年   222篇
  1986年   239篇
  1985年   212篇
  1984年   200篇
  1983年   186篇
  1982年   127篇
  1981年   107篇
  1980年   91篇
  1979年   159篇
  1978年   121篇
  1977年   108篇
  1976年   93篇
  1974年   110篇
  1973年   105篇
  1972年   87篇
  1968年   88篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
The thesis of this article is that deficits in language and communication contribute to behavior problems in childhood. Mentally retarded children show a range of deficits in language and communication compared with normals; they are also at increased risk for behavior problems. The evidence suggests that these deficits are quantitative rather than qualitative. In addition, these linguistic deficits may contribute independently to the development of behavior disorders insofar as the linguistic deficit interferes with the child's ability to make himself understood or to understand others.  相似文献   
12.
Reduced bone mineral density (BMD) was sporadically reported in patients with Marfan syndrome. This may or may not place the Marfan patient at increased risk for bone fracture. In comparing the BMDs of our patients with those reported in the literature, it seemed that agreement between values, and hence the degree of osteoporosis or osteopenia reported, was dependent on the instrumentation used. The objective of this study was to statistically assess this impression. Bone mineral density measurements from our previously published study of 30 adults with Marfan syndrome performed on a Lunar DPXL machine were compared with studies published between 1993–2000 measured using either Lunar or Hologic bone densitometry instruments. The differences of our measurements compared with those made on other Lunar machines were not statistically significant, but did differ significantly with published results from Hologic machines (P < 0.001). Before progress can be made in the assessment of BMD and fracture risk in Marfan patients and in the evidence-based orthopedic management of these patients, standardization of instrumental bone density determinations will be required along with considerations of height, obesity, age, and sex.  相似文献   
13.
In an outpatient rehabilitation setting, both patients’ use and therapists’ knowledge of complementary and alternative medicine (CAM) varies widely. Based on this observation and a recognition of CAM as an emerging practice area for rehabilitation professionals, it was felt that a thorough and consistent approach to the education and orientation of physical therapists to the world of CAM and integrative care was needed. This special interest paper will describe one center’s approach, development, and use of a unique and comprehensive training manual designed to provide both a structured and standardized approach for educating physical therapists about CAM and related therapeutic modalities. This innovative teaching tool allows for multiple methods of content delivery within a multidisciplinary format and can be used for those who practice currently or desire to practice in an integrative care environment.  相似文献   
14.
15.
This study evaluates the glycine potentiation of anticonvulsant drugs in subcutaneous pentylenetetrazol seizures in rats. Administered alone, glycine (30 or 40 mM/kg, PO) induced no anticonvulsant effect or neurological deficit. Coadministered with anticonvulsants, glycine significantly enhanced the anticonvulsant potency of diazepam and sodium valproate without affecting the neurological deficit induced by the anticonvulsants. Glycine did not significantly alter the anticonvulsant activity of ethosuximide or phenobarbital. These findings indicate a possible glycine-sensitive component in the mechanism of action of diazepam and sodium divalproate in subcutaneous pentylenetetrazol seizures. With the possible exception of sodium valproate, the present study provides little support for a glycine and gamma-aminobutyric acid (GABA) interaction as a mechanism of anticonvulsant activity in SC PTZ seizures. Further studies are required to determine the role of strychnine-sensitive and strychnine-insensitive glycine receptors in this experimental model of absence epilepsy.  相似文献   
16.
Doxorubicin (DOX) and doxorubicinol (DOXOL) were analyzed by high performance liquid chromatography in serum, bile and urine in a lymphoma patient with tumor-induced biliary obstruction. The patient had an indwelling T-tube and was given DOX containing combination chemotherapy. The bile was collected via the T-tube and given orally (together with beer) to the patient four times daily. New samples were obtained three weeks later when normal bile flow was re-established. The serum and bile concentration curves for DOX and DOXOL show great similarity between the first and second chemotherapy course, respectively. This finding strongly argues against an enterohepatic circulation of DOX or DOXOL of clinical importance in man.  相似文献   
17.
18.
19.
Islet transplants for large numbers of patients with diabetes will require xenografts. Microencapsulation is an appealing method for islet xenografting. However, graft function has been limited by a cellular reaction, particularly intense in spontaneously diabetic, NOD mice. The purpose of this study was to elucidate the mechanism of this reaction. Poly-1-lysine-alginate microcapsules containing 4000-12,000 dog or 1800-2000 rat islets were xenografted intraperitoneally into streptozotocin (SZN)-diabetic C57BL/6J and NOD mice, with or without recipient treatment with GK 1.5 (anti-CD4 monoclonal antibody) (20-30 microliters i.p. every 5 days, begun on day -7. Grafts were considered technically successful if random blood glucose (BG) was normalized (less than 150 mg/dl) within 36 hr. Graft failure was defined as BG greater than 250 mg/dl. Dog and rat islets in microcapsules normalized BG in both SZN and NOD mice within 24 hr routinely. Empty microcapsules and GK 1.5 treatments alone did not affect BG. NODs destroyed both microencapsulated dog and rat islets more rapidly than did SZN-diabetic mice (P less than .01). Graft biopsies showed an intense cellular reaction, composed of lymphocytes, macrophages and giant cells, and no viable islets. GK 1.5 treatment significantly prolonged both dog-to-NOD and rat-to-NOD grafts (P less than 0.01). Biopsies of long-term functioning grafts (on days 65-85) demonstrated viable islets and no cellular reaction around microcapsules; 1/4 rat and 1/8 dog islet xenografts continued to function indefinitely in NOD recipients, even after cessation of GK 1.5 therapy. Prediabetic NODs receiving encapsulated dog or rat islets mounted a moderate cellular reaction to grafts. Empty microcapsules excited no cellular reaction in diabetic or prediabetic NODs. We conclude that the NOD reaction to microencapsulated xenogeneic islets is helper T cell-dependent, and that the target of this reaction is not the microcapsule itself, but the donor cells within.  相似文献   
20.
SUMMARY A case congenital dislocation of both knees and dislocation of the left hip in an infant whose mother had a chronic amniotic fluid leakage after mid-trimester amniocentesis.  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