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   14119篇
  免费   736篇
  国内免费   108篇
耳鼻咽喉   117篇
儿科学   297篇
妇产科学   173篇
基础医学   1731篇
口腔科学   326篇
临床医学   912篇
内科学   3847篇
皮肤病学   144篇
神经病学   868篇
特种医学   598篇
外科学   2574篇
综合类   79篇
一般理论   1篇
预防医学   382篇
眼科学   313篇
药学   773篇
中国医学   21篇
肿瘤学   1807篇
  2023年   113篇
  2022年   175篇
  2021年   318篇
  2020年   181篇
  2019年   219篇
  2018年   339篇
  2017年   251篇
  2016年   340篇
  2015年   330篇
  2014年   454篇
  2013年   458篇
  2012年   797篇
  2011年   869篇
  2010年   498篇
  2009年   405篇
  2008年   626篇
  2007年   721篇
  2006年   712篇
  2005年   672篇
  2004年   644篇
  2003年   602篇
  2002年   577篇
  2001年   393篇
  2000年   390篇
  1999年   343篇
  1998年   169篇
  1997年   117篇
  1996年   109篇
  1995年   116篇
  1994年   91篇
  1993年   105篇
  1992年   290篇
  1991年   222篇
  1990年   223篇
  1989年   261篇
  1988年   213篇
  1987年   217篇
  1986年   194篇
  1985年   188篇
  1984年   129篇
  1983年   111篇
  1980年   42篇
  1979年   90篇
  1978年   66篇
  1977年   54篇
  1973年   41篇
  1972年   42篇
  1971年   43篇
  1970年   47篇
  1968年   48篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
Background :
The BTA test is a latex agglutination assay for the qualitative detection in the urine of analytes that are associated with bladder tumor. We compared the results of the BTA test with those of voided urine cytology (VUC) in patients with bladder cancer.
Methods :
A multicenter trial was performed at 6 institutions. A total of 132 patients with histologically diagnosed bladder cancer were enrolled. Urine samples were split for BTA and VUC testing.
Results :
The sensitivities of the BTA test and VUC were 57.6% and 37.9%, respectively; this difference was significant ( P < 0.001). The BTA test had much higher sensitivity for small, solitary, superficial tumors than did VUC.
Conclusion :
The BTA test is simple to perform, gives rapid results, and is far more sensitive than VUC for detection of bladder cancer. The BTA test has the potential to become an additional tool for detecting bladder cancer.  相似文献   
22.
We present a Merkel-cell carcinoma patient with chronic renal failure requiring haemodialysis and evaluate the pharmacokinetics of carboplatin and etoposide during haemodialysis. The area under the concentration-time curve of carboplatin was increased by prolonging the interval between administration and haemodialysis. However, that of etoposide was not changed. Carboplatin showed good membrane permeability in haemodialysis, while etoposide showed no permeability. In conclusion, the pharmacokinetics of carboplatin could be controlled by haemodialysis and the interval between chemotherapy and haemodialysis. However, the pharmacokinetics of etoposide were not affected.  相似文献   
23.
24.
Through use of a simplified analyzing system, seven vitamin B6 derivatives were determined with a satisfactory sensitivity and precision. This system consisted of a single reversed-phase ODS column with a fluorescence detector employing an isocratic solvent system. Each vitamin B6 derivative in some foods and biological materials was determined, based on the measurement of the integrated peak area. The data obtained by this method were compared with those obtained from a bioassay by Saccharomyces uvarum ATCC 9080, after acid hydrolysis of these materials.  相似文献   
25.
S Yamada  Y Takai  Y Ogawa  Y Kakuto  K Sakamoto 《Cancer》1989,64(5):1026-1028
Radiotherapy was applied to 14 esophageal carcinomas with respiratory tract fistulas using various treatment regimens. Closure of the fistulas was observed in four cases after irradiation at a daily dose of 1.5 Gy. The period of closure was transient in two cases but long-term in the other two. One long-term closure case underwent low-dose rate telecobalt therapy (LDRT)(1 Gy per hour, 7 Gy per day; a total dose of 28 Gy) as a boost. His cancer has been well controlled and he is still alive without recurrence at 74 months after fistula formation.  相似文献   
26.
Endosonography‐guided celiac plexus neurolysis (EUS‐CPN) safely and effectively relieves pain associated with intra‐abdominal malignancies when the neurolytic is accurately injected. We applied contrast medium to evaluate the ethanol injection sites in patients who received EUS‐CPN due to abdominal pain caused by malignancies. We injected, under the guidance of endoscopic ultrasonography (EUS), ethanol containing 10% contrast medium into the celiac plexus of patients with intra‐abdominal pain due to malignancies. Immediately after the endoscopic therapy, patients underwent computed tomography (CT) to confirm the injection site. Images of distribution of injected solutions were classified into three groups. Injected solution dispersed in unilateral and bilateral anterocrural space was defined as ‘unilateral injection’ or ‘bilateral injection’, respectively. Injected solution located out of the anterocrural space was defined as ‘inappropriate injection’. Pre‐ and postprocedure pain was assessed using a standard analog scale. Before and 2, 4, 8, 12, and 16 weeks after the procedure, pain scores were evaluated. From April 2003 to May 2005, 13 patients were enrolled in this study. Improvement of pain score in the ‘bilateral injection’ and ‘unilateral injection’ groups was significantly superior to the change in the ‘inappropriate injection’ group. Although EUS‐CPN was effective in eight of 13 patients (61.5%), additional EUS‐CPN to the ‘inappropriate injection group’ increased the response rate to 84.6%. Injection of ethanol to the anterocrural space by EUS‐CPN produced adequate pain relief. Immediate examination by CT for confirmation of injection sites after EUS‐CPN would increase the likelihood of induction of pain relief.  相似文献   
27.
Our objective was to analyze problems in the perioperative management and long-term outcome of living donor liver transplantation (LDLT) for biliary atresia (BA). Many reports have described the effectiveness of liver transplantation (LT) for BA, particularly in pediatric cases, but little information is available regarding LT in adults (> or =16 years old). Between June 1990 and December 2004, 464 patients with BA underwent LDLT at Kyoto University Hospital, of whom 47 (10.1%) were older than 16 years. In this study, we compared the outcomes between adult (> or =16 years old) and pediatric (<16 years old) patients. The incidence of post-transplant intestinal perforation, intra-abdominal bleeding necessitating repeat laparotomy and biliary leakage was significantly higher (p < 0.0001, <0.001 and <0.001, respectively) in adults. Overall cumulative 1-, 5- and 10-year survival rates in pediatric patients were significantly higher (p < 0.005) than in adults. Two independent prognostic determinants of survival were identified: a MELD score over 20 and post-transplant complications requiring repeat laparotomy. Outcome of LDLT in adult BA patients was poorer than in pediatric patients. It seems likely that LT will be the radical treatment of choice for BA and that LDLT should be considered proactively at the earliest possible stage.  相似文献   
28.
A 14-year-old girl was admitted because of cough, chest pain and hemosputum. Chest roentgenogram on admission showed a pneumothorax and a cavitary lesion with niveau formation in the right lung and cystic lesions in the bilateral lung fields. After bed rest and intravenous administration of antibiotics for two weeks, the right lung inflated well and the niveau formation disappeared, and the patient was discharged. One week later, she was readmitted with sudden-onset severe dyspnea, caused by bilateral pneumothoraces. Emergency tube thoracostomy and wedge resection of the bullous lesion was performed. Macroscopically, multiple small cystic changes were seen on the surface of the right lung. Histological examination revealed nodular proliferations of smooth muscle cells in the interstitium and vessel walls in the lung, which contained slit-like lymphatic channels. The diagnosis of pulmonary lymphangiomyomatosis was made. In this case, we could not measure receptors for estrogen and progesterone. Recently, hormonal therapy and oophorectomy have been reported as being useful. Tamoxifen (Norvadex) was therefore initiated, and the patient has remained well with slight dyspnea on exertion. There has been no recurrence of pneumothorax. Lymphangiomyomatosis is a rare disease of unknown etiology which occurs exclusively in women, mostly in those of reproductive age. We report a 14-year-old female patient with lymphangiomyomatosis associated with repeated pneumothorax, who had been under treatment for epilepsy. We believe this case to be of importance because of the long discussed relation between pulmonary lymphangiomyomatosis and tuberous sclerosis.  相似文献   
29.
The admission of antihypertensive medications in the elderly (65 y.o. or more, 269 pts) was compared to that in younger cases (less than 65 y.o., 348 pts). All were outpatients who visited our clinic in 1990. The number of patients on a single therapeutic regimen was almost equal in both age groups. Once-a-day regimens were more common in the young (56.9% vs 48.3%, p less than 0.05), and three times-a-day regimens were more common in the elderly (14.7% vs 23.1%, p less than 0.01). The choice of antihypertensive drugs in patients with single therapy or combined therapy in the young was beta blockers in 49.7%, Ca blockers in 39.4%, diuretics in 30.7% and ACE inhibitors in 17.8%, and those in the elderly were Ca blockers in 46.1%, diuretics in 44.2%, beta blockers in 33.8%, and ACE inhibitors in 16.4%. The patients were subdivided into three groups according to the time of the initial visit to the clinic; initial visit during 1969-1979 (phase 1), 1980-1984 (phase 2) and 1985-1990 (phase 3). In the young, choice of beta blockers and diuretics was most popular in phase 1. However, the choice of diuretics decreased in phase 2, and in phase 3 beta blockers were used in 50.4%, Ca blockers in 43.2%, ACE inhibitors in 22.3% and diuretics in only 17.3%. In the elderly, diuretics were most popular followed by Ca blockers and beta blockers in phase 1 and phase 2. In phase 3 Ca blockers were selected in 58.2% followed by both beta blockers and ACE inhibitors in 28.4% then diuretics in 23.9%.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
30.
PURPOSETo determine whether steady-state free precession sequences improve the MR visibility of epidermoid tumors in comparison with spin-echo images.METHODSPatients were four women and three men with epidermoid tumors in the subarachnoid spaces. MR was performed with a 1.5-T superconductive unit. For steady-state free precession imaging, three-dimensional Fourier transform fast imaging with steady-state free precession (FISP) images were used (20-40/7 [repetition time/echo time], flip angle of 25 degrees). The visualization and contrast-to-noise ratio were compared in FISP images and spin-echo images. In one case, the images of FISP and fast low-angle shot were obtained with variable repetition times and flip angles to evaluate the best pulse sequences for the visualization of epidermoid tumors.RESULTSThe contrast-to-noise ratios between tumors and cerebrospinal fluid ranged from 7.9 to 17.5 (average was 12.9) on FISP images. The average of contrast-to-noise ratios on T1, T2, and proton density-weighted spin-echo images were 1.6, 2.0, and 4.2, respectively. Three-dimensional Fourier transform FISP images best showed central nervous system and demonstrated epidermoid tumors excellently.CONCLUSIONSEpidermoid tumors in the subarachnoid spaces were better demonstrated on steady-state free precession (three-dimensional Fourier transform FISP) than on conventional spin-echo images.  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