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   15550篇
  免费   1322篇
  国内免费   65篇
耳鼻咽喉   205篇
儿科学   348篇
妇产科学   226篇
基础医学   2019篇
口腔科学   215篇
临床医学   1701篇
内科学   3353篇
皮肤病学   379篇
神经病学   942篇
特种医学   647篇
外科学   2580篇
综合类   113篇
现状与发展   1篇
一般理论   4篇
预防医学   1301篇
眼科学   516篇
药学   1129篇
中国医学   83篇
肿瘤学   1175篇
  2024年   16篇
  2023年   181篇
  2022年   442篇
  2021年   841篇
  2020年   449篇
  2019年   551篇
  2018年   639篇
  2017年   423篇
  2016年   503篇
  2015年   518篇
  2014年   653篇
  2013年   703篇
  2012年   1117篇
  2011年   1086篇
  2010年   645篇
  2009年   516篇
  2008年   897篇
  2007年   880篇
  2006年   748篇
  2005年   698篇
  2004年   616篇
  2003年   539篇
  2002年   493篇
  2001年   493篇
  2000年   451篇
  1999年   369篇
  1998年   120篇
  1997年   100篇
  1996年   87篇
  1995年   75篇
  1994年   68篇
  1993年   58篇
  1992年   149篇
  1991年   103篇
  1990年   118篇
  1989年   107篇
  1988年   92篇
  1987年   79篇
  1986年   65篇
  1985年   54篇
  1984年   47篇
  1983年   32篇
  1982年   19篇
  1981年   11篇
  1980年   14篇
  1979年   15篇
  1978年   6篇
  1977年   10篇
  1976年   8篇
  1975年   7篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Current methods of peripheral nerve repair are to directly suture cut nerve stumps, or to bridge large gaps with an autograft repair. Autograft-associated problems include donor site morbidity and limited supply. Many of the present limitations of nerve repair might be overcome by expanding the patients own Schwann cells in vitro, then combining the cells with other neuro-tropic and -trophic materials into an Artificial Nerve Graft (ANG) for bridging a nerve gap. In this 4.5 month experiment, a rat peroneal nerve model with a 10 mm gap was used to evaluate the effect of live Schwann cells on peripheral nerve regeneration. Nerve gaps were repaired with cellular ANGs containing live Schwann cell, dead Schwann cell, or mixed fibroblast/Schwann cell populations suspended in a collagen I matrix, and with sutured autografts or ANGs containing just collagen or medium. Regenerated nerves were evaluated by walking track analysis, qualitative and quantitative histology, and electrophysiology. Overall, the autograft was the best repair method, while the ANG containing live Schwann cells was statistically superior to other ANG repair methods. This study demonstrates that an ANG containing cultured syngeneic Schwann cells improves functional, histological, and electrophysiological parameters of peripheral nerve regeneration.  相似文献   
72.
The personality of patients suffering from Parkinson's disease has been considered as the basis of a psychosomatic theory or more simply as a form of reaction. Between these two extremes the controversy continues and is modified by the use of dopaminergic agents. In this study, 30 patients suffering from parkinson's disease undergo a psychological examination and a M.M.P.I.; the results allow us to determine a pre-morbid obsessive personality coupled with agressivity and ambition. A transformation occurs with the arrival of illness; dependence, passivity, suggestibility evolve in a context where anxiety is relieved of all agressivity but acquires a depressive character. The people surrounding the patients play a part in this transformation. Moreover the pre-morbid characteristics of these patients remind the physician of H. Tellenbach's "typus melancholicus".  相似文献   
73.
Cancer chemotherapy in the elderly: a series of 51 patients aged>70 years   总被引:1,自引:0,他引:1  
Summary A total of 2,238 new cancer patients were treated in our institution in 1988; among the 423 (18.9%) who were>70 years old, 51 underwent chemotherapy. The median age was 75.8 years, and the Karnofsky performance status (KPS) was 70% for 40 patients. Malignancies were hematopoietic in 24 cases (47%) and digestive in 15 patients (29%), and 12 subjects (24%) had other types of cancers. The first chemotherapy course was given at the full dose to 23/51 (45.1%) patients. The drug dose was reduced for 28/51 (54.9%) patients, due in 25 cases to the subjects being>70 years old. Neither age, KPS, pretreatment assessment, nor cancer extent was correlated with the modifications made to the first cycle. An overall toxicity of grade 3+4 (WHO grading scale) was noted in 10 subjects (19.6%). Although these elderly patients were probably selected, analysis of their charts did not evidence an increase in chemotherapy toxicity, regardless of the dose they received.Presented at the EORTC Pharmacokinetics and Metabolism Group Meeting, Bordeaux, November 1990  相似文献   
74.
Acute myeloid leukemias (AML) and myelodysplastic syndromes (MDS) enter rarely in the differential diagnosis of myelofibrosis (MF). MF of marked intensity, resulting in either "dry taps" or non-representative smears, is encountered in approximately 10% of cases. MF may be observed in any type of AML, most frequently in acute megakaryoblastic leukemia (M7). Apart from some typical cases of MDS, MF is associated with cases of acute myelodysplasia with myelofibrosis (and a major megakaryocytic component). This syndrome has been described under various headings: acute or malignant myelosclerosis, and acute MF. It should be distinguished from M7 and from myeloproliferative syndromes.  相似文献   
75.
The dopamine transporter (DAT) provides major regulation of the synaptic levels of dopamine and is a principal target of psychostimulant drugs. Associations between DAT gene polymorphisms and human disorders with possible links to dopaminergic neurotransmission, including attention-deficit/hyperactivity disorder (ADHD) and consequences of cocaine and alcohol administration, have been reported. We now report approximately 60000 bp of genomic sequence containing the entire DAT gene. This sequence was used to amplify each of the 15 DAT gene exons and several introns and analyze these amplification products by single-stranded sequence conformation (SSCP) and/or direct sequencing. These results define silent allelic single nucleotide sequence variants in DAT gene exons 2, 6, 9 and 15. Rare conservative mutations are identified in amino acids encoded by DAT exons 2 and 8. Analyses of the common nucleotide variants and the previously reported VNTR in the non-coding region of exon 15 define the pattern of linkage disequilibrium across the DAT locus. These comprehensive analyses, however, fail to identify any common protein coding DAT sequence variant in more than 150 unrelated individuals free of neuropsychiatric disease, 109 individuals meeting City of Hope criteria for Tourette's syndrome, 64 individuals with DSM-IV diagnoses of ethanol dependence, or 15 individuals with ADHD. These data are consistent with substantial evolutionary conservation of the DAT protein sequence. They suggest that gene variants that alter levels of DAT expression provide the best current candidate mechanism for reported associations between DAT gene markers, ADHD and other more tentatively associated neuropsychiatric disorders.  相似文献   
76.
Cochlear implants are the single greatest advancement of the late 20th century for the deaf and hearing impaired. Recent expanding guidelines as well as surgical techniques are discussed. Cochlear implantation is currently the only means to restoring partial hearing to patients with severe-to-profound sensorineural loss not aidable with conventional amplification.  相似文献   
77.
Experimental studies revealed that the contractile response of the urinary bladder to sacral anterior root stimulation depends on the actual bladder volume. Furthermore, no clinical relevant technique is available for continuous monitoring of the bladder wall distension respectively bladder volume in paraplegic patients. The presented study investigates the reliability of especially developed implantable ultrasound sensors as a sensoric system for continuous monitoring of the bladder volume. In six anaesthesized pigs two ultrasound sensors, one transmitter and one receiver, were implanted on the bladder wall at different locations (latero-lateral, dorsal-ventral, rostral-caudal). After closing the abdominal wall, the bladder was filled in 50 ml steps up to 250 ml. After each filling step the running time of the ultrasound signal was measured. In all experiments reproducible results and a high correlation of the measured running times with bladder volume were observed. The latero-lateral configuration of the sensors seemed to be most confidential. The presented study indicates that bladder volumetry with implantable ultrasound sensors is possible with minimal technical prerequisites. This promising technique for continuous bladder volumetry could play an important role in the development of an intelligent and autoadaptive neurostimulator of the urinary bladder in paraplegic patients.  相似文献   
78.
79.
At the University of California San Francisco Comprehensive Cancer Center, a computer database system was created using the FileMaker Pro database program. The system allows the clinical team to bring together data from all aspects of a multidisciplinary effort toward improving daily clinical management, for research, and ultimately, for the clinical standard of care for melanoma patients. With modest objectives during the initiation of the database, its adaptability has allowed it to become an integral link in all the efforts of the melanoma program. For the future, tapping into the immense potential of the Internet has begun to organize multicenter efforts. Through nationwide collaboration, the Sentinel Lymph Node Working Group will be able to follow, on a larger scale, the successes of the FileMaker pro database at the UCSF Comprehensive Cancer Center.  相似文献   
80.
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