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   3594篇
  免费   384篇
  国内免费   83篇
耳鼻咽喉   21篇
儿科学   155篇
妇产科学   64篇
基础医学   436篇
口腔科学   93篇
临床医学   508篇
内科学   646篇
皮肤病学   211篇
神经病学   208篇
特种医学   380篇
外科学   340篇
综合类   141篇
一般理论   1篇
预防医学   372篇
眼科学   61篇
药学   307篇
肿瘤学   117篇
  2021年   58篇
  2020年   26篇
  2019年   57篇
  2018年   68篇
  2017年   47篇
  2016年   70篇
  2015年   56篇
  2014年   79篇
  2013年   104篇
  2012年   134篇
  2011年   122篇
  2010年   99篇
  2009年   117篇
  2008年   134篇
  2007年   189篇
  2006年   128篇
  2005年   128篇
  2004年   119篇
  2003年   111篇
  2002年   117篇
  2001年   138篇
  2000年   116篇
  1999年   101篇
  1998年   104篇
  1997年   90篇
  1996年   68篇
  1995年   86篇
  1994年   61篇
  1993年   70篇
  1992年   70篇
  1991年   57篇
  1990年   71篇
  1989年   100篇
  1988年   94篇
  1987年   69篇
  1986年   60篇
  1985年   85篇
  1984年   59篇
  1983年   35篇
  1982年   44篇
  1981年   33篇
  1980年   38篇
  1979年   31篇
  1978年   26篇
  1977年   29篇
  1976年   39篇
  1974年   31篇
  1973年   28篇
  1972年   27篇
  1967年   24篇
排序方式: 共有4061条查询结果,搜索用时 31 毫秒
1.
Coronary artery bypass grafts: visualization with MR imaging   总被引:1,自引:0,他引:1  
Gomes  AS; Lois  JF; Drinkwater  DC  Jr; Corday  SR 《Radiology》1987,162(1):175
  相似文献   
2.
OBJECTIVE: To establish if there is a role for gabapentin or nortriptyline in the treatment of chronic orchialgia. METHODS: Twenty-six consecutive patients with chronic orchialgia were seen in the chronic pain clinic by a multidisciplinary team. A pain questionnaire was completed prior to commencing either gabapentin or nortriptyline. They were reviewed at 3 months and a repeat questionnaire completed. A 50% improvement in pain was considered successful. RESULTS: Complete data was available for 19 patients. Overall, 61.5% of patients commenced on gabapentin and 66.6% of patients commenced on nortriptyline had a greater than 50% improvement in pain. Patients with post-vasectomy testicular pain were considered as a subgroup. None of these patients had a greater than 50% improvement in pain. However, 80% of patients in the subgroup with idiopathic chronic orchialgia had a greater than 50% improvement in pain. CONCLUSION: Although this is a small study, it appears that gabapentin and nortriptyline are effective in the treatment of idiopathic chronic orchialgia but not post-vasectomy pain.  相似文献   
3.
OBJECTIVE: The aim of this study was to determine whether the survival of patients with untreated synchronous liver metastases after resection of a colorectal cancer was associated with any features of the primary tumour. METHODS: Information for 398 consecutive patients with unresected liver metastases in the period 1971-2001 was examined by multivariate survival analysis. RESULTS: Of 19 clinical and pathological variables considered, survival was independently associated only with residual tumour in a line of resection (hazard ratio (HR) 1.95), venous invasion (HR 1.87), right colonic tumour (HR 1.68), lymph node metastasis (HR 1.54), and extra-hepatic metastasis (HR 1.16); 8.3% of patients had none of these adverse features. Their 2-year overall survival rate was 39.2%, compared with only 16.5% (P < 0.001) in those with one or more adverse features. CONCLUSIONS: These findings may assist in selecting patients most likely to benefit from treatment of hepatic metastases and in counselling patients and their relatives.  相似文献   
4.
5.
Summary— The influence of local resistance and cardiac performance on peripheral blood acceleration was investigated in 14 healthy male volunteers. Steady and pulsatile flow was studied in the brachial and in the common carotid arteries, ie, two territories that exhibit marked differences in resistive characteristics. Instantaneous blood velocity (V), mean blood velocity (Vm) and artery diameter (D) were evaluated at rest by an ultrasonic range-gated pulsed Doppler flowmeter using a double transducer probe, thus allowing the calculation of mean blood flow (Q). Mean local resistance (R) was obtained by dividing the mean arterial pressure by Q. The peak value of the local acceleration of the blood was obtained by computer-assisted calculation of the first derivative of instantaneous blood velocity (Gmax = +dV/dtmax). Peak aortic blood acceleration (GAo) was simultaneously measured from the suprasternal notch using a pulsed Doppler velocity meter. In the brachial and the common carotid arteries, Gmax was of a similar magnitude (551 ±30 and 555 ± 44 cm/s2, respectively) despite major differences in the respective D, Vm, Q and R values. In neither artery was there a relationship between Gmax and either resting Q or R. At the brachial artery level, Gmax was positively related to GAo ( r = 0.79, P = 0.0008). At the common carotid artery level, there was a weak, although non significant relationship between Gmax and GAo ( P = 0.08). Our results indicate that the local acceleration of peripheral blood flow in the brachial artery is related rather to upstream central impulse than to downstream hemodynamics, and suggest some regional differences in the hemodynamic determinants of the local acceleration of peripheral blood flow.  相似文献   
6.
Synovial sarcoma is a rare malignancy that occurs most frequently in the extremities. Its onset and associated symptoms are often insidious and therefore can be misleading. The authors review this primary malignancy and offer a case report to illustrate the importance of including such entities in the differential diagnosis and subsequent treatment of soft tissue masses found in the foot.  相似文献   
7.
In a prospective, randomized, double-blind study, 49 patients underwent lumbar myelography using iotrol (24 patients) or metrizamide (25 patients). The diagnostic imaging adequacy of iotrol was comparable with that of metrizamide. After iotrol myelography, adverse reactions were fewer, less severe, and of shorter duration than were those following metrizamide myelography. Thirteen of 24 patients (54%) receiving iotrol reported some adverse reactions compared with 24 of 25 patients (96%) receiving metrizamide. Five moderate and one severe adverse reaction occurred in the group receiving iotrol. Fourteen moderate and eight severe adverse reactions occurred in the group receiving metrizamide. Thirty-eight patients underwent electroencephalography both before and after myelography (19 iotrol and 19 metrizamide). None of the EEGs obtained after iotrol myelography changed from baseline, while seven of the EEGs obtained after metrizamide myelography showed changes from baseline. Iotrol was judged superior to metrizamide as a contrast medium in this patient population.  相似文献   
8.
9.
10.
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