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   11320篇
  免费   621篇
  国内免费   38篇
耳鼻咽喉   102篇
儿科学   789篇
妇产科学   340篇
基础医学   1236篇
口腔科学   229篇
临床医学   689篇
内科学   2233篇
皮肤病学   366篇
神经病学   619篇
特种医学   307篇
外国民族医学   1篇
外科学   1601篇
综合类   278篇
一般理论   12篇
预防医学   475篇
眼科学   559篇
药学   1200篇
中国医学   57篇
肿瘤学   886篇
  2023年   81篇
  2022年   182篇
  2021年   379篇
  2020年   226篇
  2019年   305篇
  2018年   346篇
  2017年   272篇
  2016年   347篇
  2015年   315篇
  2014年   442篇
  2013年   591篇
  2012年   808篇
  2011年   861篇
  2010年   459篇
  2009年   345篇
  2008年   612篇
  2007年   574篇
  2006年   487篇
  2005年   450篇
  2004年   414篇
  2003年   336篇
  2002年   323篇
  2001年   289篇
  2000年   291篇
  1999年   243篇
  1998年   92篇
  1997年   65篇
  1996年   82篇
  1995年   63篇
  1994年   47篇
  1993年   43篇
  1992年   117篇
  1991年   159篇
  1990年   126篇
  1989年   106篇
  1988年   107篇
  1987年   75篇
  1986年   85篇
  1985年   89篇
  1984年   65篇
  1983年   68篇
  1979年   66篇
  1978年   44篇
  1977年   35篇
  1975年   34篇
  1973年   38篇
  1972年   41篇
  1971年   44篇
  1969年   32篇
  1968年   44篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
Muscle involvement in hypothyroidism commonly manifests as fatigue, myalgias, stiffness and slowed reflexes. We report a case of transient acute renal failure related to rhabdomyolysis and myoglobinuria in a 40 year old man that revealed the diagnosis of hypothyroidism with myopathy. The patient had proximal muscle weakness and tenderness, markedly raised muscle enzymes and deranged renal functions that normalised with thyroid replacement therapy. Hypothyroidism, though rare, should be considered a definite and authentic cause of rhabdomyolysis.  相似文献   
92.
The cytologic appearance of epithelioid sarcoma in fine-needle aspiration biopsy cytology (FNABC) smears has not been extensively described. We report a case of epithelioid sarcoma in a 55-year-old male who presented with nodular swellings in the abdominal wall and scrotum. The scrotal swelling was subsequently demonstrated to arise from the vas deferens. We highlight the cytomorphologic, immunocytochemical, and histopathologic features of this rare lesion in an unusual site, with particular emphasis on the dilemma encountered in the cytodiagnosis of this lesion.  相似文献   
93.
PurposeCartridge based nucleic acid amplification test (CBNAAT) has been endorsed by the WHO as the screening test for diagnosing extrapulmonary tuberculosis (EPTB). In the present study we report the agreement between CBNAAT (Xpert MTB/RIF), liquid culture (LC) and line probe assay (LPA) for diagnosis of Mycobacterium tuberculosis and detection of drug resistance among EPTB cases.MethodsThe EP samples were subjected to CBNAAT (Xpert MTB/RIF, Cepheid, USA) and wherever possible, to LC (MGIT 960, Becton Dickinson, USA) followed sequentially by first line and second line-LPA (FL-LPA, SL-LPA, Hain Lifescience, Germany) on the isolates.ResultsTotal 566/4080 (13.9%) EP samples were detected positive for M. tuberculosis on CBNAAT. Aspirates from lymph nodes were most often positive (11/30; 36.6%), followed by pus (240/873; 27.5%) and CSF samples (166/104; 15.8%). The detection of M. tuberculosis was more in adults than children except in tissue biopsy samples. Rifampicin resistance was also higher among adults except CSF in which resistance was more in children. Total 185 of 566 (32.7%) CBNAAT positive and 770 of 3510 (21.9%) CBNAAT negative samples could be cultured of which 110/185 (59.4%) and 33/770 (4.3%) respectively turned positive. FL-LPA and SL-LPA of 143 culture isolates showed that 27 isolates had drug resistance, of which 3 (2.1%) were XDR, 11 (7.7%) were Pre-XDR (FQ) and 13 (9.1%) were MDR. Of these 27 resistant isolates, 12 were negative by CBNAAT and two were mislabeled as Rifampicin sensitive or indeterminate based on the unique RpoB gene mutation patterns on LPA. The positive and negative agreements between LC and CBNAAT for detection of M. tuberculosis were 67.1% and 92.7% respectively and between LPA and CBNAAT for rifampicin resistance detection were 98.9% and 92.9% respectively.ConclusionsFor EPTB, CBNAAT should be accompanied with LC wherever possible irrespective of the CBNAAT result.  相似文献   
94.
Alcoholic cirrhosis is one of the most common indications for liver transplantation. Previous researchers have studied rates of return to drinking following transplantation, however, few have employed prospective measures of alcohol use. The authors prospectively studied the alcohol use of patients transplanted for alcoholic liver disease. The authors improved the accuracy of monitoring alcohol use by using various methods for tracking patient's alcohol consumption, and we report on the time to first alcohol use after transplantation comparing these different methods. The authors found that alcohol use can occur very early after transplantation, even within the first 3 months posttransplant. Thirty-eight percent of the patients consumed any alcohol after transplantation. The clinical interviews by the psychiatrist were the most successful method for identifying posttransplant alcohol use. Posttransplant alcohol use was significantly associated with prior nonalcohol substance use (P < 0.025), family history of alcoholism in a first-degree relative (P < 0.025), and prior alcohol rehabilitation experience (P < 0.05) but not with a prior psychiatric history or less than 6 months of pretransplant sobriety. The authors indicate that prospective monitoring, using a combination of methods, is the most accurate approach to identify alcohol consumption. With this type of accuracy, risk factors can be identified and alcohol use can be compared with alcohol-related morbidity posttransplant.  相似文献   
95.
96.
Severe lower limb defects in exstrophy of the cloaca   总被引:1,自引:0,他引:1  
We present here a patient with exstrophy of the cloaca associated with severe lower limb defects. The limb malformations include, on the right, a split foot with distal separation of the tibia and fibula, and on the left, attachment of the lower half of the left leg with a two-toed foot at nearly a right angle to the mid left thigh. A review of the literature indicates that 17-26% of patients with cloacal exstrophy also have lower limb defects. We hypothesize that cloacal exstrophy and associated lower limb defects have a related pathogenesis and that both are related to deficiencies of caudal mesoderm or mesodermal differentiation signals. More cases of exstrophy of the cloaca with limb defects need to be reported to better characterize the limb anomalies and to more precisely determine their frequency.  相似文献   
97.
98.
Sorbitol Intolerance in Adults   总被引:3,自引:0,他引:3  
Sorbitol is a commonly used sugar substitute in "sugar-free" food products. Although sorbitol intolerance manifested by abdominal pain, bloating, and diarrhea has been observed in children, it has not been well documented in adults. Forty-two healthy adults (23 whites, 19 nonwhites) participated in this study. After ingestion of 10 g of sorbitol solution, end expiratory breath samples were collected at 15-min intervals for 4 h and analyzed for H2 concentration. Clinical sorbitol intolerance was detected in 43% of the whites and 55% of the nonwhites, the difference not being statistically significant. However, severe clinical sorbitol intolerance was significantly more prevalent in nonwhites (32%) as compared to whites (4%). There was a good correlation between the severity of symptoms and the amount of hydrogen exhaled. Dietetic foods, many of them containing sorbitol, are very popular with diabetics and "weight watchers." Based on our observations, we believe that a large number of adults could be suffering from sorbitol-induced nonspecific abdominal symptoms and diarrhea. These symptoms could lead to an extensive diagnostic work-up and lifelong diagnosis of irritable bowel syndrome.  相似文献   
99.
Transport of molecules across tumor vasculature   总被引:16,自引:0,他引:16  
The vascular-extravascular exchange of fluid and solute molecules in a tissue is determined by three transport parameters (vascular permeability, P, hydraulic conductivity, Lp, and reflection coefficient, ); the surface area for exchange, A; and the transluminal concentration and pressure gradients. The transport parameters and the exchange area for a given molecule are governed by the structure of the vessel wall. In general, tumor vessels have wide interendothelial junctions; large number of fenestrae and transendothelial channels formed by vesicles; and discontinuous or absent basement membrane. While these factors favor movement of molecules across tumor vessels, high interstitial pressure and low microvascular pressure may retard extravasation of molecules and cells, especially in large tumors. These characteristics of the transvascular transport have significant implications in tumor growth, metastasis, detection and treatment.  相似文献   
100.
Verma KS  Jain AK  Nagar A  Gupta SR 《Planta medica》1986,52(4):315-317
Macrocarposide has been isolated for the first time as a natural product from the heartwood of PTEROCARPUS MACROCARPUS along with some known compounds. Based on its spectral and chemical evidence, it has been assigned the structure dalbergioidin-6- C-glucoside ( 1).  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