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   6403篇
  免费   356篇
  国内免费   34篇
耳鼻咽喉   104篇
儿科学   95篇
妇产科学   122篇
基础医学   937篇
口腔科学   56篇
临床医学   462篇
内科学   1170篇
皮肤病学   277篇
神经病学   519篇
特种医学   558篇
外科学   937篇
综合类   36篇
一般理论   1篇
预防医学   261篇
眼科学   275篇
药学   335篇
中国医学   4篇
肿瘤学   644篇
  2023年   34篇
  2022年   55篇
  2021年   113篇
  2020年   95篇
  2019年   122篇
  2018年   140篇
  2017年   130篇
  2016年   137篇
  2015年   179篇
  2014年   188篇
  2013年   276篇
  2012年   426篇
  2011年   451篇
  2010年   269篇
  2009年   252篇
  2008年   442篇
  2007年   417篇
  2006年   414篇
  2005年   398篇
  2004年   393篇
  2003年   391篇
  2002年   282篇
  2001年   78篇
  2000年   59篇
  1999年   87篇
  1998年   84篇
  1997年   73篇
  1996年   54篇
  1995年   47篇
  1994年   45篇
  1993年   27篇
  1992年   43篇
  1991年   31篇
  1990年   35篇
  1989年   28篇
  1988年   28篇
  1987年   27篇
  1986年   28篇
  1985年   28篇
  1984年   27篇
  1983年   31篇
  1982年   27篇
  1981年   18篇
  1980年   19篇
  1979年   17篇
  1978年   22篇
  1977年   19篇
  1976年   12篇
  1975年   11篇
  1973年   11篇
排序方式: 共有6793条查询结果,搜索用时 78 毫秒
111.
IntroductionErectile dysfunction (ED) and lower urinary tract symptoms suggestive of benign prostatic hyperplasia (LUTS/BPH) are common in aging males and frequently occur together. Tadalafil has demonstrated efficacy in treating both conditions.AimThe study aims to evaluate the efficacy and safety of tadalafil 5 mg once daily vs. placebo over 12 weeks in treating both LUTS/BPH and ED in sexually active men. We also assessed relationships of baseline disease severity and prostate specific antigen (PSA) to outcomes.MethodsData were pooled from four multinational, randomized studies of men ≥45 years with LUTS/BPH, with analyses restricted to sexually active men with ED. Randomization (baseline) followed a 4‐week placebo run‐in; changes from baseline were assessed vs. placebo using analysis of covariance.Main Outcome MeasuresInternational Prostate Symptom Score (IPSS), IPSS subscores, Quality‐of‐Life Index (IPSS‐QoL), BPH Impact Index (BII), and International Index of Erectile Function‐Erectile Function (IIEF‐EF) Domain score were used in this study.ResultsTadalafil (N = 505) significantly improved total IPSS vs. placebo (N = 521); mean changes from baseline were ?6.0 and ?3.6, respectively (P < 0.001). Improvements in IIEF‐EF Domain score (tadalafil, 6.4; placebo, 1.4) were also significant vs. placebo, as were the IPSS storage and voiding subscores, IPSS‐QoL, and BII (all P < 0.001).No significant impact of baseline ED severity or PSA category on IPSS response was observed (interaction P values, 0.463 and 0.149, respectively). Similarly, improvement in IIEF‐EF Domain score was not significantly impacted by baseline LUTS/BPH severity or PSA category (interaction P values, 0.926 and 0.230, respectively). Improvements in IPSS and IIEF‐EF Domain score during treatment were weakly correlated (r = ?0.229). Treatment‐emergent adverse events were consistent with previous reports.ConclusionsTadalafil was efficacious and well tolerated in treating ED and LUTS/BPH in sexually active men with both conditions. Improvements in both conditions were significant regardless of baseline severity. Improvements in the total IPSS and the IIEF‐EF Domain score were weakly correlated. Porst H, Roehrborn CG, Secrest RJ, Esler A, and Viktrup L. Effects of tadalafil on lower urinary tract symptoms secondary to benign prostatic hyperplasia and on erectile dysfunction in sexually active men with both conditions: Analyses of pooled data from four randomized, placebo‐controlled tadalafil clinical studies. J Sex Med 2013;10:2044–2052.  相似文献   
112.
Chronic obstructive pulmonary disease (COPD) is associated with high morbidity and mortality. COPD is typified by persistent, progressive airflow limitation and a range of respiratory and systemic symptoms such as breathlessness, coughing, wheezing, depression, anxiety, general fatigue, and sleeping difficulties. Despite receiving treatment for COPD, many patients suffer from regular symptoms that affect their daily lives and lead to increased morbidity. These symptoms vary in severity, frequency, and type, and can occur at any time throughout the 24-h day, with over half of patients with COPD experiencing symptoms in the morning, during the day, and at nighttime. Despite the prevalence of symptoms, patient and physician perception of the impact of COPD symptoms on patients’ lives is not always in concordance. Dual bronchodilator therapy with a long-acting muscarinic antagonist (LAMA) and long-acting beta agonist (LABA) has the potential to treat the symptoms of COPD in addition to improving lung function. This review therefore examines the burden of symptoms experienced throughout the day by patients with COPD and the evidence for combined LAMA/LABA treatment in terms of symptom management. As patients with COPD experience varying symptoms throughout the course of their disease, the role of tailoring treatment to the individual needs of the patient is also examined. We conclude that the symptoms of COPD are troublesome, variable, can occur during all parts of the 24-h day, and have a substantial impact on patients’ health status and quality of life. In order to provide effective, patient-orientated care, patients with COPD should be evaluated on the basis of lung function, the frequency of symptoms, and patient-perceived impact of symptoms on their lives. Therapy should be chosen carefully based on individualized assessment, ensuring personalization to the individual needs of the patient.  相似文献   
113.
114.
These three case reports describe the long-term duration of function of ovarian cortical tissue grafts among patients in a university fertility preservation programme in Europe and in a private practice programme in the USA. One woman underwent sterilizing cancer treatment and had frozen ovarian tissue transplanted, and two women underwent fresh ovarian tissue transplants. The function of ovarian cortical strips has continued for more than 7 years in these three women, with the birth of eight healthy babies following a single graft per patient. In addition to these three cases, transplantation (repeatedly in some cases) of cryopreserved ovarian tissue has restored reproductive function to all other women in the study centres’ programmes for some years. The sustained longevity of function of the transplanted tissue suggests that it may also be possible to postpone the normal time of menopause or to alleviate its symptoms.These three case reports describe the long-term duration of function of ovarian cortical tissue grafts among patients in a university fertility preservation programme in Europe and in a private practice programme in the USA. One woman underwent sterilizing cancer treatment and had frozen ovarian tissue transplanted, and two women underwent fresh ovarian tissue transplants. Function of ovarian cortical strips has continued for more than 7 years in these three women, with the birth of eight healthy babies following a single graft per patient. In addition to these three cases, transplantation (repeatedly in some cases) of cryopreserved ovarian tissue has restored reproductive function to all other women in our programmes for some years. The sustained longevity of function of the transplanted tissue suggests that it may also be possible to postpone the normal time of menopause or to alleviate its symptoms.  相似文献   
115.
116.
Aims:  Gastrointestinal stromal tumours (GISTs) display genetic alterations on chromosome 22. GTn repeat (GTn) length polymorphism in the promoter of haeme oxygenase-1 gene ( HMOX-1 ) is located on chromosome 22 and associated with malignant growth. The aim was to investigate the role of HMOX-1 promoter polymorphism in GIST patients.
Methods and results:  Tumour and corresponding healthy tissue DNA of 44 patients who underwent surgical resection of GIST were analysed by polymerase chain reaction, capillary electrophoresis and DNA sequencing. GTn polymorphism was classified into short (S) and long (L) allele. There was no difference detected in GTn genotype between tumour and healthy tissue DNA. Short GTn allele (SGTn) was significantly associated with metastatic disease, higher tumour recurrence rates and high risk GIST (consensus criteria 2001). Furthermore, SGTn allele carriers had significantly shorter disease-free and overall survival (log rank test, P  < 0.0001). On multivariate Cox regression analysis, GTn polymorphism was identified as an independent prognostic factor for survival ( P  = 0.001).
Conclusions:  HMOX-1 promoter GTn polymorphism is a potential prognostic marker and may help to allocate patients to different risk groups, customized therapy and follow-up. Haeme oxygenase-1 could represent an important candidate gene in the pathogenesis and growth of GIST.  相似文献   
117.
118.
We characterized 168 junctional regions of T-cell receptor delta (TCRD) rearrangements from 116 children with acute lymphoblastic leukemia (ALL) (101 with precursor B-cell ALL, 15 with T-cell ALL). Application of 101 allele-specific oligonucleotide (ASO) probes representing 85 Vdelta2Ddelta3, 10 Ddelta2Ddelta3, 3 Vdelta1Jdelta1, 1 Vdelta3Jdelta1, and 2 Ddelta2Jdelta1 junctions for the detection of minimal residual disease (MRD) revealed detection levels of 10(-4) to 10(-6) leukemia cells in the vast majority of cases (93 of 101). Of interest was that neither the N, D, P (nontemplated, diversity, palindromic) content and length of the junctional regions nor the number of nucleotides deleted from the flanking V, D, or J (variable, diversity, joining) elements correlated with the sensitivity of ASO probes. These data indicated that in ALL TCRD rearrangements can serve as suitable tools for the detection of MRD irrespective of the specific composition of the junctional region.  相似文献   
119.
120.
BACKGROUND: Schistosoma haematobium infection causes severe urinary disease and considerable mortality. The factors that determine disease progression from mild to severe stages are not fully understood. METHODS: Here we describe a cross-sectional epidemiological study of kidney and bladder diseases in 2 Dogon populations with different exposure to S. haematobium infection. RESULTS: Early and high exposure resulted in more-severe disease, especially among young subjects, without clear evidence of a more-rapid development of immunity. Nevertheless, 50%-60% of subjects of all age classes in both villages showed no evidence of disease. Kidney and bladder disease peaked biphasically among young subjects and adults >25 years old. The first peak corresponded with infections of maximum intensity, whereas the second peak occurred among adults with infections of very low intensity. Kidney disease was correlated with circulating anodic antigen concentration in serum, whereas bladder disease was correlated with egg count and eosinophil cationic protein concentration in urine. Kidney and bladder disease did not correlate. Severe kidney disease was more frequent in certain families. CONCLUSIONS: The frequency of urinary disease is increased by infections acquired early during life, is regulated by strong clinical immunity in certain subjects, and may be dependent on hereditary factors. Kidney and bladder disease may involve different mechanisms of pathogenesis, which may differ between children and adults.  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