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   1048篇
  免费   52篇
  国内免费   8篇
耳鼻咽喉   2篇
儿科学   25篇
妇产科学   12篇
基础医学   145篇
口腔科学   29篇
临床医学   121篇
内科学   220篇
皮肤病学   8篇
神经病学   57篇
特种医学   39篇
外科学   232篇
综合类   10篇
预防医学   37篇
眼科学   25篇
药学   61篇
肿瘤学   85篇
  2023年   6篇
  2022年   14篇
  2021年   16篇
  2020年   9篇
  2019年   19篇
  2018年   18篇
  2017年   18篇
  2016年   14篇
  2015年   30篇
  2014年   26篇
  2013年   33篇
  2012年   47篇
  2011年   61篇
  2010年   34篇
  2009年   28篇
  2008年   40篇
  2007年   55篇
  2006年   46篇
  2005年   47篇
  2004年   48篇
  2003年   53篇
  2002年   53篇
  2001年   23篇
  2000年   19篇
  1999年   29篇
  1998年   11篇
  1997年   11篇
  1996年   8篇
  1994年   10篇
  1993年   12篇
  1992年   27篇
  1991年   26篇
  1990年   15篇
  1989年   13篇
  1988年   21篇
  1987年   17篇
  1986年   14篇
  1985年   13篇
  1984年   11篇
  1983年   8篇
  1982年   7篇
  1980年   6篇
  1979年   7篇
  1977年   6篇
  1976年   7篇
  1974年   11篇
  1973年   12篇
  1971年   7篇
  1968年   9篇
  1967年   9篇
排序方式: 共有1108条查询结果,搜索用时 15 毫秒
1.
Finasteride is standard medical treatment for androgenetic alopecia; however, no large studies with 5 years or more of follow up have been performed in Japan. The authors followed Japanese men with androgenetic alopecia treated with finasteride for 5 years to evaluate long‐term treatment efficacy. Of 903 men treated with finasteride (1 mg/day), 801 patients were evaluated over 5 years by modified global photographic assessment. Although the proportion of improvement was high (99.4%), modified global photographic assessment scores after 5 years of treatment were lower in patients with more advanced disease as measured by the modified Norwood–Hamilton scale. After separating patients into “sufficient” and “insufficient” efficacy groups according to the modified global photographic assessment score after 5 years (scores ≥6 and <6, respectively), multivariate analysis showed that independent risk factors of insufficient efficacy were age at start of treatment of 40 years or more (P = 0.021) and classification on the modified Norwood–Hamilton scale (P < 0.001), whereas presence of stress at start of treatment was a negative predictor (P = 0.025). In conclusion, continuous finasteride treatment for 5 years improved androgenetic alopecia with sustained effect among Japanese. Younger age and less advanced disease at start of treatment were the key predictors of higher finasteride efficacy.  相似文献   
2.
Pericardial abscess is rare in healthy individuals, especially the amebic type. We report a case of pericardial abscess and cardiac tamponade due to intrapericardial rupture of an amebic liver abscess. A 31-year old Japanese male complained of fever to a local hospital. A liver mass was discovered in his left hepatic lobe by an abdominal echogram. He was referred to the internal department of our hospital and was treated with quinolone antibiotics. Two weeks after medication, he suddenly complained of epigastralgia and severe orthopnea and was admitted. Abdominal computed tomographic scan showed an enlarged liver mass, and massive pericardial effusion suggested cardiac tamponade. He underwent an emergency subxiphoid partial pericardiectomy under local anesthesia. 1,000 ml of light brownish fluid was removed and his condition improved. Although no ameba was cultivated from the pus, the amebic serological test was positive. Metronidazole was administered and the patients was discharged 31 days after surgery.  相似文献   
3.
Thrombin-antithrombin III complex (TAT) and plasminogen activator inhibitor (PAI) were measured during liver resection surgery in 8 patients. TAT and PAI activities of patients under liver resection were compared with those of 11 patients under resection of esophageal carcinoma. TAT activity increased during liver resection (P < 0.001) and reached 14 times (P < 0.001) of its control value in the recovery room. PAI activity was very stable during operation, but increased to twice (P < 0.01) of its control value in the recovery room. TAT activity of patients after liver surgery in the recovery room was (P < 0.05) more than twice of that of patients after esophageal surgery. We conclude that hypercoagulable state occurred during liver resection to a greater degree compared with that observed with esophageal surgery, and that its cause might be liver resection itself.  相似文献   
4.
In seven patients undergoing right hemicolectomy for benign or malignant diseases, latero-lateral end anastomoses were made using stapling devices, LS (linear stapler) and GIA (gastrointestinal anastomosis). As no complications directly related to the anastomosis occurred, we conclude that anastomosis using stapling devices for right hemicolectomy is a safe and rapid procedure.  相似文献   
5.
6.
7.
OBJECTIVE: Severe aortic arch obstruction including an interrupted aortic arch in congenital complex heart anomalies remains a challenge in surgical management. METHODS: Treatment and outcomes in 75 consecutive patients who underwent an aortic arch repair as the first step of the staged repair protocol between 1975 and 2000 were reviewed. Their ages at repair ranged from 1 day to 8.5 months. RESULTS: Cross-sectional postoperative follow-up data were available in all the patients. The follow-up period ranged from 0 to 27.6 years (mean: 7.3 +/- 7.3 years). There were 20 postoperative hospital deaths (27%) and 7 late deaths. The Kaplan-Meier estimate of survival was 81.3% +/- 4.5% at 1 month, 68.0% +/- 5.4% at 1 year, 65.0% +/- 5.5% at 5 years, 63.1% +/- 5.7% at 10 years, 63.1% +/- 5.7% at 20 years. By Cox regression analysis, body weight of 2.5 kg or less is the only independent determinant of postoperative mortality (p = 0.04, multivariable odds ratio: 2.50, [95% confidence interval: 1.02-6.1]). The aortic arch morphology, the primary cardiac lesion, or date of operation did not reach a statistically significant level to show correlation with mortality. Reintervention to reconstruct the aortic arch was performed at 9 occasions in 8 of the 55 patients who survived the primary operation (14.5%). The Kaplan-Meier estimate of the reintervention-free rate was 91.3% +/- 4.2% at 5 years, 85.5% +/- 5.6% at 10 years, 75.6% +/- 8.2% at 20 years. Using multivariable Cox regression analysis, interrupted aortic arch (versus aortic coarctation) was the only independent predictor of a shorter time to reintervention (p = 0.001, multivariable odds ratio: 16.1, [95% confidence interval: 3.2-80.2]). CONCLUSIONS: The staged repair protocol was associated with significant limitations in patient survival and with the development of recurrent aortic arch obstruction. Thus, a primary repair protocol may serve as an alternate approach, especially in patients with low weight or with an interrupted aortic arch.  相似文献   
8.
To elucidate the role of vascular endothelial growth factor (VEGF), an endothelial cell-specific mitogen, in tumour angiogenesis and malignant progression, an expression vector harboring human VEGF cDNA was stably transfected into three human cancer cell lines with poor VEGF productivity. Though their in vitro growth rate and intrinsic productivity of another angiogenic factor, basic fibroblast growth factor (bFGF), were not changed by transfection, those clones with higher VEGF production were endowed with tumorigenic and angiogenic potentials as follows: firstly, nontumorigenic, lung carcinoma QG90 cells having lower bFGF productivity acquired tumorigenicity as well as significant in vivo angiogenesis-inducing ability, secondly, tumorigenic colorectal carcinoma RPMI4788 cells having higher potency for bFGF production could form more vascularized solid tumour with faster growth rate and thirdly, oestrogen-dependent breast carcinoma MCF-7 cells, which did not produce detectable bFGF, acquired tumorigenicity even in the absence of oestrogen and the solid tumour growth rate was remarkably enhanced, accompanied with increased vascularization, in the presence of oestrogen. These results suggest that tumour progression closely depends on angiogenesis, and VEGF significantly contributes to malignant progression of a variety of tumour cells through its potent angiogenic activity, independent on the bFGF productivity of tumour cells.  相似文献   
9.
Although various genetic factors have been implicated in human male infertility, the causative genes for the different types of idiopathic male infertility have not been elucidated. Protamines, which are the major DNA-binding proteins in the sperm nucleus, package the DNA into the sperm head. Analysis of the human protamine-1 (PRM1) and -2 (PRM2) gene sequences in 226 sterile male patients and in 270 proven-fertile male volunteers revealed four single nucleotide polymorphisms (SNPs) in the PRM1 coding region, which did not cause any amino acid substitutions, and one SNP in the PRM2 gene, which produced translation termination. We also observed one SNP in the 3' non-coding region of the PRM1 gene, and two SNPs within the intron of the PRM2 gene. The prevalence of these SNPs was similar in both infertile patients and in proven-fertile volunteers, except that the c248t alteration in the PRM2 gene induced a nonsense codon under conditions of heterozygosity in one infertile patient. Although the PRM1 and PRM2 genes are highly conserved, the single SNP in the PRM2 gene that induces translation termination may result in male infertility due to haploinsufficiency of PRM2.  相似文献   
10.
Retinal amacrine cells are interneurons that make lateral and vertical connections in the inner plexiform layer of the retina. Amacrine cells do not possess a long axon, and this morphological feature is the origin of their naming. Their dendrites function as both presynaptic and postsynaptic sites. Half of all amacrine cells are GABAergic inhibitory neurons that mediate lateral inhibition, and their light-evoked response consists of graded voltage changes and regenerative action potentials. There is evidence that the amount of neurotransmitter release from presynaptic sites is increased by spike propagation into the dendrite. Thus understanding of how action potentials propagate in dendrites is important to elucidating the extent and strength of lateral inhibition. In the present study, we used the dual whole cell patch-clamp technique on the soma and the dendrite of cultured rat amacrine cells and directly demonstrated that the action potentials propagate into the dendrites. The action potential in the dendrite was TTX sensitive and was affected by the local membrane potential of the dendrite. Propagation of the action potential was suppressed by local application of GABA to the dendrite. Dual dendrite whole cell patch-clamp recordings showed that GABA suppresses the propagation of action potentials in one dendrite of an amacrine cell, while the action potentials propagate in the other dendrites. It is likely that the action potentials in the dendrites are susceptible to various external factors resulting in the nonuniform propagation of the action potential from the soma of an amacrine cell.  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