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   16153篇
  免费   1297篇
  国内免费   90篇
耳鼻咽喉   145篇
儿科学   580篇
妇产科学   416篇
基础医学   2028篇
口腔科学   238篇
临床医学   2040篇
内科学   3128篇
皮肤病学   471篇
神经病学   1522篇
特种医学   471篇
外科学   1979篇
综合类   368篇
一般理论   10篇
预防医学   1515篇
眼科学   269篇
药学   978篇
中国医学   6篇
肿瘤学   1376篇
  2021年   202篇
  2020年   134篇
  2019年   242篇
  2018年   263篇
  2017年   193篇
  2016年   223篇
  2015年   243篇
  2014年   319篇
  2013年   519篇
  2012年   735篇
  2011年   830篇
  2010年   441篇
  2009年   444篇
  2008年   753篇
  2007年   772篇
  2006年   743篇
  2005年   775篇
  2004年   693篇
  2003年   612篇
  2002年   623篇
  2001年   496篇
  2000年   518篇
  1999年   438篇
  1998年   189篇
  1997年   179篇
  1996年   123篇
  1995年   135篇
  1994年   126篇
  1992年   365篇
  1991年   355篇
  1990年   370篇
  1989年   353篇
  1988年   263篇
  1987年   299篇
  1986年   306篇
  1985年   304篇
  1984年   204篇
  1983年   232篇
  1982年   125篇
  1979年   205篇
  1978年   142篇
  1977年   125篇
  1976年   139篇
  1975年   135篇
  1974年   145篇
  1973年   136篇
  1972年   107篇
  1971年   101篇
  1970年   119篇
  1969年   104篇
排序方式: 共有10000条查询结果,搜索用时 421 毫秒
81.
后路脊椎V型截骨术治疗创伤性脊柱后凸畸形   总被引:1,自引:1,他引:0  
目的总结应用椎弓根钉-棒系统后路脊椎V型截骨术治疗创伤性脊柱后凸畸形的临床经验、技术要点及效果。方法将创伤性脊柱后凸畸形的病人分为两组,进行对比分析。治疗组:应用椎弓根钉-棒系统后路V型截骨内固定术29例;对照组:应用前路椎体骨折复位内固定融合术26例。结果与对照组相比,治疗组术后畸形复发率显著低于对照组(P〈0.05),断钉、松动等并发症发生率显著低于对照组(P〈0.05),骨折不融合、纠正后凸畸形度数对比无显著性差异(P〉0.05)。结论应用椎弓根钉-棒系统后路V型截骨术治疗的创伤性脊柱后凸畸形可有效防止手术后畸形再发生,矫正后凸畸形彻底、安全、可靠。  相似文献   
82.
Axonal damage is a major factor contributing to permanent disability in patients with multiple sclerosis (MS); it has been extensively investigated in the brain using magnetic resonance spectroscopy (MRS). In this study, MRS was used to investigate the degree of neuronal damage in the cervical spinal cord in MS. Spectra were acquired from spinal cord and brain in 11 patients with MS (expanded disability status score [EDSS], range 2.5-7.0) and 11 controls. Brain lesion volume and spinal cord cross-sectional area were measured. Concentration of the neuronal metabolite N-acetyl-aspartate ([NAA]) was reduced in the spinal cord in MS patients relative to controls (reduced by 32%, P < 0.05), indicating significant neuronal damage. Additionally, the spinal cord was significantly atrophied in MS patients (15%, P < 0.001). No significant reduction in brain [NAA] was seen in the MS group. There were no correlations between clinical measures and cord atrophy or brain lesion volume on MRI; however, spinal cord [NAA] correlated with the cerebellar subscore of the neurological assessment (P < 0.005), while brain [NAA] correlated with disease duration (P < 0.05). MRS demonstrated cellular damage within the cord over and above the tissue atrophy seen by MRI. Combining MRI and MRS may therefore give a more complete picture of neurodegeneration in the spinal cord.  相似文献   
83.
The diagnosis of molar pregnancy is a continuing diagnostic problem for many practicing histopathologists who are required to examine specimens of products of conception, particularly since changes in gynecological management in recent years have resulted in uterine evacuation at earlier gestations. The aim of this review is to provide practical, up-to-date, diagnostically useful information regarding the histological diagnosis of molar disease in early pregnancy. Pathophysiological issues relevant to molar pregnancies, such as genetic abnormalities, will be briefly summarized, but nonhistopathological aspects of molar disease will not be covered in detail in this review.  相似文献   
84.
85.
86.
Since Samuel Orton's (1937) assertion that dyslexia reflects abnormal brain organization, the relationship of learning disabilities to brain dysfunction has been the topic of considerable debate. Recently, learning-disabled individuals have been studied in conjunction with those known to have neurological dysfunction, in a search for common subtypes. In the present study, a population of 177 children, ages 9-0 to 14-0, were assessed on an augmented version of the Children's Halstead-Reitan Battery. One hundred twenty-nine Ss were learning-disabled, 37 of whom also had verified brain damage. The remaining 48 children had neither learning disabilities nor evidence of brain damage. Patterns of neuropsychological performance were determined using Tryon's clustering methods. The procedure yielded six subject clusters: (A) and (B)—children with low general intellectual ability; (C) children who are clumsy and lethargic; (D) children with language dysfunction; (E) children with faulty spatial orientation; and (F) children with no detectable neuropsychological deficits. These clusters were similar to those identified by investigators who have used other subject-clustering methods. Brain-damaged individuals were more prevalent in some clusters (e.g., A and B) than in others (e.g., E and F), and substantial numbers of learning disabled subjects were also found in clusters where brain-damaged individuals tended to cluster, indicating similar neuropsychological profiles. The cluster structure was validated by comparison with subtypes identified by other investigators, as well as by tests of association between clusters with exogenous factors (e.g., history of prematurity; seizures).  相似文献   
87.
88.
89.
A reversed-phase high-performance liquid chromatographic method using coulometric electrochemical detection in the oxidative mode has been developed for the analysis of 3-(9-chloro-5,6-dihydro-11-H-pyrrolo[2,1-b][3]benzazepine-11-ylidene- N,N-dimethyl-1-propanamine(E)-Z-butenedioate hydrogen maleate (1) in plasma of patients dosed with 2-8 mg/kg/d of the drug. Concentrations as little as 0.1 ng/mL of 1 in plasma can be estimated with a mean coefficient of variation of 7.4 +/- 1.08%. The utility of the procedure was demonstrated by the analysis of 500 patient samples from a rising multiple-dose study.  相似文献   
90.
Summary A total of 16 patients with recurrent epithelial ovarian cancer were treated with sulofenur (LY 186641), a novel oral sulfonylurea. All subjects had received previous chemotherapy. Anaemia occurred in all 16 patients, 14 of whom required a blood transfusion, and 2/16 patients received methylene blue for breathlessness due to methaemaglobinaemia. Treatment was discontinued in 2/16 cases due to rising liver enzyme values, which reverted to normal on cessation of the drug. There was no nausea or alopecia. Only two minor responses were seen. Plasma drug levels were insufficient to result in antitumour activity as extrapolated from animal data. Further studies that attempt to increase the bioavailability and improve the therapeutic index are warranted.  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