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   45294篇
  免费   3489篇
  国内免费   135篇
耳鼻咽喉   592篇
儿科学   1139篇
妇产科学   552篇
基础医学   5680篇
口腔科学   476篇
临床医学   4761篇
内科学   9160篇
皮肤病学   481篇
神经病学   4472篇
特种医学   1788篇
外科学   8732篇
综合类   349篇
现状与发展   1篇
一般理论   56篇
预防医学   3758篇
眼科学   801篇
药学   2858篇
中国医学   34篇
肿瘤学   3228篇
  2024年   61篇
  2023年   479篇
  2022年   852篇
  2021年   2059篇
  2020年   1069篇
  2019年   1711篇
  2018年   2066篇
  2017年   1450篇
  2016年   1470篇
  2015年   1622篇
  2014年   2330篇
  2013年   2755篇
  2012年   4356篇
  2011年   4248篇
  2010年   2230篇
  2009年   1886篇
  2008年   2969篇
  2007年   3075篇
  2006年   2584篇
  2005年   2310篇
  2004年   2018篇
  2003年   1692篇
  2002年   1478篇
  2001年   170篇
  2000年   133篇
  1999年   175篇
  1998年   259篇
  1997年   201篇
  1996年   144篇
  1995年   122篇
  1994年   99篇
  1993年   76篇
  1992年   59篇
  1991年   45篇
  1990年   40篇
  1989年   40篇
  1988年   38篇
  1987年   43篇
  1986年   33篇
  1985年   38篇
  1984年   38篇
  1983年   35篇
  1982年   39篇
  1981年   27篇
  1980年   32篇
  1979年   15篇
  1978年   17篇
  1974年   19篇
  1973年   17篇
  1972年   14篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
131.
132.
One hundred six undergraduate (83 women and 23 men) completed surveys concerning their most traumatic life event, the feedback they received following their disclosure of the event to others, and how they felt after the disclosure. Results indicated that the better they felt after disclosure, the less disturbed they were by thoughts of the event at the time of the study. In addition, the more personal the trauma was, the worse they felt after their disclosure, and the more disturbed they were about the trauma. However, no significant relation existed between the positivity (e.g., supportiveness) of their confidant's feedback and their present degree of disturbance. Implications for understanding the complex relation between confiding traumatic events and resolving feelings surrounding those events were discussed.  相似文献   
133.
Phosphorus was imaged in vivo in human cortical and trabecular bone and the T(1) and T(2) (*) were measured. An ultrashort TE (UTE) pulse sequence (TE = 70 microm) was used with half pulse excitation and radial mapping of k-space from the center out. T(2) (*) was measured using multiple echo times and T(1) was measured both by saturation recovery and by a method using different RF pulse amplitudes. Seven normal subjects (32-85 years) were examined. Phosphorus was imaged, with a true in-plane resolution of 2.9 x 2.9 mm and a signal-to-noise ratio (SNR) of 19:1, in both cortical and trabecular bone. The mean T(2) (*) value was 207 +/- 12 micros, and the mean T(1) value was 8.6 +/- 3.0 sec. Images and measurements were obtained in realistic times on a clinical MR system. This may provide a new approach to characterizing disease of bone.  相似文献   
134.
In vitro human hepatocyte cultures are a key tool in the investigation of xenobiotic toxicity and metabolism. In most in vitro hepatocyte studies, the cells are allowed to adhere to an extracellular matrix, such as collagen. Unfortunately, the ability of freshly isolated hepatocytes to adhere to collagen varies from donor to donor. We used microarray analysis to determine what gene expression differences exist between hepatocytes in suspension and hepatocytes attached to collagen. Results from different donors showed a considerable difference in gene expression patterns between the two hepatocyte populations. In addition, we also compared the gene expression profiles of hepatocytes in culture with liver tissue. The results showed that both hepatocytes in suspension and hepatocytes attached to collagen display significant gene expression differences compared with liver tissue. Finally, we show that both populations of hepatocytes are responsive to dexamethasone and regulate some of the same genes. Overall, our results suggest that either significant gene expression changes occur in isolated hepatocytes or that suspended and attached cells represent different populations of hepatocytes found in intact livers.  相似文献   
135.

Background  

Statin-related skeletal muscle disorders range from benign myalgias – such as non-specific muscle aches or joint pains without elevated serum creatinine kinase (CK) concentration – to true myositis with >10-fold elevation of serum CK, to rhabdomyolysis and myoglobinuria. The genetic basis of statin-related muscle disorders is largely unknown. Because mutations in the COQ2 gene are associated with severe inherited myopathy, we hypothesized that common, mild genetic variation in COQ2 would be associated with inter-individual variation in statin intolerance. We studied 133 subjects who developed myopathy on statin monotherapy and 158 matched controls who tolerated statins without incident or complaint.  相似文献   
136.
Harvey Cushing was a man of many talents. Not only was he a premier surgeon and scientist, but a prolific author and artist as well. In this paper, we present two postoperative sketches of pediatric brain tumors drawn by Dr. Cushing. These sketches are representative of drawings which accompany many of his operative notes at the Peter Bent Brigham Hospital. About 25% of Cushing's surgical sketches depict operations performed on children. The most commonly drawn childhood tumors were craniopharyngiomas and gliomas of the brain stem and cerebellum. These drawings reveal how Cushing maintained detailed records of his surgical experience. It is clearly evident from these records that Dr. Cushing gained substantial experience in the treatment of pediatric brain tumors.  相似文献   
137.
138.
139.
OBJECTIVES: To investigate common presentations and expected outcomes in patients with traumatically induced otologic dysfunction. STUDY DESIGN: Retrospective case review of patients who underwent otologic surgery for sequelae of otologic trauma over a 28-year period. Patients were stratified into major and minor trauma cohorts. Major trauma was designated as closed head injury with or without temporal bone fracture; lower-energy insults comprised the minor trauma group. Preoperative and postoperative audiograms were obtained and correlated with extent of injury. SETTING: Tertiary referral center. RESULTS: Major trauma accounted for 44.9 percent of all patients. The remaining 55.1 percent suffered minor trauma, of which simple traumatic tympanic membrane perforation was the most common insult (33.6%). Two hundred twenty-seven cases were performed on 214 patients. Pure tone averages improved a significant 20.8 dB to essentially normal levels postoperatively. CONCLUSION: Regardless of injury extent, surgical rehabilitation of conductive losses attains excellent hearing results that surpass those historically reported for the chronic ear population.  相似文献   
140.
Renal transplantation has increased the longevity of patients with uremia. An increasing number undergo aortic reconstruction, which exposes the transplanted kidney to ischemic injury. To evaluate the risk for renal failure, loss of the transplant, and methods of renal protection, we reviewed our experience. Clinical data were reviewed for 10 consecutive patients (7 men, 3 women; mean age 52.7 years [range 32 to 75 years]) with a transplanted kidney who underwent aortic reconstruction between 1977 and 1994 at our institution. Mean interval between renal transplantation and aortic reconstruction was 5.9 years (range 1 month to 12.7 years). Seven patients required emergency repair because of dissection (2 patients), aneurysm rupture (4 patients), or symptomatic aneurysm (1 patient); three underwent elective repair. Reasons for reconstruction included aortic dissection (2 patients), aneurysm of the descending thoracic (2 patients), thoracoabdominal (1 patient), or abdominal aorta (3 patients), and aortoiliac occlusive disease (2 patients). Patients with thoracic or thoracoabdominal reconstructions underwent repair with atriofemoral, aortofemoral, or femorofemoral shunt placement or bypass. Of the five abdominal aortic reconstructions, the kidney was protected with aortofemoral shunt placement in one patient and cold renal perfusion in three. In two of them, topical cooling of the kidney also was used. One patient with acute aortic dissection died at 39 days as a result of respiratory failure. Loss of the recently transplanted kidney was caused by acute rejection. One patient had a transient increase in serum creatinine concentration. Eight had no worsening of renal function, and none of the nine survivors lost the transplanted kidney. We conclude that aortic reconstruction can be safely performed in kidney transplant recipients. Patients in whom thoracic or thoracoabdominal aortic reconstruction was required were protected with an atriofemoral or aortofemoral bypass or shunt. Patients undergoing abdominal aortic reconstruction did well when cold renal perfusion with or without local cooling of the transplant was used for renal protection. Transplanted kidneys appeared to tolerate ischemic injury similarly to native kidneys.Presented at the Twentieth Annual Meeting of the Peripheral Vascular Surgery Society, New Orleans, La., June 10, 1995.  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