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   3224篇
  免费   225篇
  国内免费   32篇
耳鼻咽喉   20篇
儿科学   98篇
妇产科学   41篇
基础医学   364篇
口腔科学   32篇
临床医学   201篇
内科学   1134篇
皮肤病学   65篇
神经病学   125篇
特种医学   74篇
外科学   589篇
综合类   12篇
预防医学   82篇
眼科学   28篇
药学   220篇
中国医学   2篇
肿瘤学   394篇
  2023年   42篇
  2022年   39篇
  2021年   129篇
  2020年   59篇
  2019年   81篇
  2018年   114篇
  2017年   94篇
  2016年   102篇
  2015年   127篇
  2014年   143篇
  2013年   163篇
  2012年   267篇
  2011年   288篇
  2010年   156篇
  2009年   150篇
  2008年   213篇
  2007年   200篇
  2006年   175篇
  2005年   192篇
  2004年   166篇
  2003年   146篇
  2002年   132篇
  2001年   27篇
  2000年   15篇
  1999年   23篇
  1998年   29篇
  1997年   21篇
  1996年   20篇
  1995年   21篇
  1994年   24篇
  1993年   13篇
  1992年   10篇
  1991年   13篇
  1990年   9篇
  1989年   6篇
  1988年   7篇
  1987年   7篇
  1986年   5篇
  1985年   5篇
  1984年   10篇
  1982年   3篇
  1981年   6篇
  1980年   3篇
  1978年   6篇
  1977年   7篇
  1973年   2篇
  1969年   2篇
  1968年   2篇
  1966年   1篇
  1962年   1篇
排序方式: 共有3481条查询结果,搜索用时 15 毫秒
1.
Mutations in the gene encoding 11beta-hydroxysteroid dehydrogenase type 2, HSD11B2, cause a rare monogenic juvenile hypertensive syndrome called apparent mineralocorticoid excess (AME). In AME, defective HSD11B2 enzyme activity results in overstimulation of the mineralocorticoid receptor (MR) by cortisol, causing sodium retention, hypokalemia, and salt-dependent hypertension. Here, we have studied whether genetic variations in HDS11B2 are implicated in essential hypertension in Japanese hypertensives and the general population. By sequencing the entire coding region and the promoter region of HDS11B2 in 953 Japanese hypertensives, we identified five missense mutations in 11 patients (L14F, n = 5; R74H, n = 1; R147H, n = 3; T156I, n = 1; R335H, n = 1) and one novel frameshift mutation (4884Gdel, n = 1) in a heterozygous state, in addition to 19 genetic variations. All genetic variations identified were rare, with minor allele frequencies less than 0.005. Four of 12 patients with the missense/frameshift mutations showed renal failure. Four missense mutations, L14F, R74H, R147H, and R335H, were successfully genotyped in the general population, with a sample size of 3,655 individuals (2,175 normotensives and 1,480 hypertensives). Mutations L14F, R74H, R147H, and R335H were identified in hypertensives (n = 6, 8, 3, and 0, respectively) and normotensives (n = 8, 12, 5, and 0, respectively) with a similar frequency, suggesting that these missense mutations may not strongly affect the etiology of essential hypertension. Since the allele frequency of all of the genetic variations identified in this study was rare, an association study was not conducted. Taken together, our results indicate that missense mutations in HSD11B2 do not substantially contribute to essential hypertension in Japanese.  相似文献   
2.
The fit and fill of the femoral canal are critical to the success of cementless femoral stems in total hip arthroplasty. It is difficult for conventional stems to provide a good fit and fill for the femora of patients with secondary osteoarthritis. Based on measurements of 100 femora of these patients, we designed two types of Fukui Medical School (FMS) stems with a proximal lateral flare that differed in the medial radius. We compared the fit and fill of the FMS stems with those of four conventional stems, using computer simulation. The mean proximal fit and total fit of the FMS stems were 46% and 53% respectively, a significant improvement compared with the other stems examined. The mean fill of FMS stems was 82% at the lower end of the lesser trochanter and 84% at the upper end of the isthmus, values that were significantly higher than those of the other stems. Since September 1995, we have implanted FMS stems in 15 hips with secondary osteoarthritis. Radiographic evaluations showed that the canal fill of the FMS stems was significantly greater in the proximal femur compared with other stems previously inserted at our department. A summary of this paper was presented at the 9th Symposium on Computer-Assisted Radiology; June 1995, Berlin, and at the 8th International Symposium on Technology in Arthroplasty; September 1995, Puerto Rico.  相似文献   
3.
Congenital absence of the portal vein (CAPV) is a rare malformation of the splanchnic venous system. Although CAPV is usually detected in the pediatric age group, our patient was a 35-year-old woman. She had been diagnosed with CAPV in 1996 when she was 27 years old. In 1998, she was placed on hemodialysis due to chronic renal failure. After several episodes of encephalopathy in 2002, liver transplantation (LT) was recommended to her and her family. Since there was no suitable living donor candidate, she was put on the waiting list for a deceased donor liver transplant in Japan. In 2004, her ammonia level increased to around 300 microg/dl, and she went into a coma lasting for three days. After recovering from this event, she underwent a living domino transplantation using a whole liver donated by a familial amyloid polyneuropathy (FAP) patient. Her portal vein, which had drained directly into the inferior vena cava (IVC), was transected together with a cuff of the IVC wall and anastomosed to the graft liver portal vein in an end-to-end fashion. In conclusion, liver transplantation proved to be a safe and effective way to save this patient and improve her quality of life.  相似文献   
4.
The requirement for endoscopic access to a stricture is a major limitation of the endoscopic dilatation for the treatment of strictures in the gastrointestinal tract. We have developed the double‐balloon enteroscopy method that enables visualization of the entire small bowel. In addition, double‐balloon enteroscopy has a potential for the interventional therapy including dilatation of strictures. We present here a case of jejunal strictures in a 47‐year‐old woman with Crohn's disease successfully treated with a balloon catheter in combination with double‐balloon enteroscopy. Balloon dilation with double‐balloon enteroscopy is a promising method for the treatment of small bowel strictures in Crohn's disease.  相似文献   
5.
We have found that steroid bolus withdrawal prior to graft reperfusion increased the incidence of acute cellular rejection (ACR). This study aims to clarify how initial steroid bolus (ISB) injection at reperfusion influences the kinetics of CD8(+) alloreactive immune responses immediately after living donor liver transplantation (LDLT). A total of 49 hepatitis C virus (HCV)-infected recipients were classified into 3 groups according to hierarchical clustering by preoperative CD8(+)CD45 isoforms. The naive T cell proportion was considerably higher in Group I than in Groups II and III, whereas Group II recipients had the highest effector memory (EM) T cells and Group III the highest effector T cells. The frequency of ACR was significantly higher in recipients without ISB than in those with ISB. In particular, the ACR rates were the highest in Group II without ISB. Following ISB, the proportion of effector T cells was promptly upregulated within 6 hours after graft reperfusion, simultaneously with the upregulation of CD27(-)CD28(-) subsets, interferon-gamma (IFN-gamma), tumor necrosis factor-alpha and perforin expression, which significantly correlated with increasing interleukin (IL)-12 receptor beta 1 cells. These were then downregulated to below preoperative levels by tacrolimus (Tac) administered at 24 hours. These changes did not occur in the absence of ISB. In Group II without ISB, the downregulation of IL-12Rbeta1(+) cells was the greatest, consistent with the highest rates of ACR and mortality (60%). In conclusion, ISB must be done in place, especially in Group II with preexisting high EM T cells, to enable the development of early allograft acceptance.  相似文献   
6.
This report concerns the long-term outcome of living donor liver transplantation (LDLT) for pediatric patients at a single center. Between June 1990 and December 2003, a total of 600 LDLTs, including 568 primary transplantations and 32 retransplantations, were performed for pediatric patients, who were immunosuppressed with FK506 and low-dose corticosteroids. Patient survival at 1, 5, and 10 years were 84.6%, 82.4%, and 77.2%, respectively, and the corresponding findings for graft survivals were 84.1%, 80.9%, and 74.5%. Multivariate analysis demonstrated that fulminant hepatic failure (FHF), a graft vs. body weight (GBWR) ratio of <0.8, and ABO-incompatible transplants were independently associated with both patient and graft survival. The retransplantation rate was 6%, and 55 patients (9.7%) have been completely weaned off immunosuppressants. Long-term patient and graft survival after pediatric LDLT for a large cohort of children at our hospital were found to be as good as those for cadaveric liver transplantation, although this series includes 13% liver transplantations with ABO-incompatible donors, which are obviously inferior in patient and graft survival. To obtain better outcomes for patients with FHF and for patients with ABO-incompatible transplants, immunosuppressive therapy needs to be improved.  相似文献   
7.
One hundred and thirty-four patients with vasoocclusive diseases were retrospectively tested for three kinds of antiphospholipid antibody (aPL). The mean age at onset of the disease in 58 patients with aPL was 43 years old. Seventeen, 11, and 9 patients were positive for the aCL IgA, IgM, and IgG isotypes, respectively. The rates of anti-phospholipid syndrome (APS) in patients with arterial (n=94), venous (n= 31), or both arterial and venous (n=9) occlusion were 45%, 29%, and 78%, respectively.The rates of APS in patients with autoimmune disease (n=13), thromboangiitis obliterans (TAO) (n= 36), arteriosclerosis obliterans (ASO) with lower leg involvement (n=8) or aortic arch syndrome (n=5), Raynaud's syndrome (n=15), aortitis syndrome (n= 13), ischemic heart disease (IHD) with young onset (n =12), and bilateral leg deep venous thrombosis (DVT) (n=10) were 77%, 46%, 13%, 80%, 40%, 62%, 33%, and 70%, respectively. The cumulative patency rate for reconstructive surgery in patients (n=13) with aCL was found to be considerably lower than that in those without aCL (n=13). From these results it was concluded that IgA was the most valuable aCL isotype for the diagnosis of APS and that aPL should be examined in patients with double-vessel occlusion, autoimmune disease, bilateral leg DVT, aortic arch syndrome, TAO, Raynaud's syndrome, or IHD with young onset. Furthermore, prophylaxis for graft failure is more strongly recommended for patients with aCL than for those without it.  相似文献   
8.
Yamamoto and colleagues have developed a novel insertion method of the endoscope, the ‘double balloon method’ for enteroscopy and, recently, a specialized system for the ‘double balloon method’ has been commercialized by Fujinon. The double balloon endoscopy enables visualization of the entire small bowel and also allows for interventional therapy in the small intestine. This method could be used either from the oral or anal approach. Observation of an affected area with controlled movement of the endoscope enables interventions, including biopsies, hemostasis, balloon dilatation, stent placement, polypectomy, and endoscopic mucosal resection. The procedure is safe and useful, and it provides high diagnostic yields and therapeutic capabilities.  相似文献   
9.
We examined a gene polymorphism of a novel Z-disc-related protein, myospryn (cardiomyopathy-associated 5). We focused on one haplotype block associated with a tag single nucleotide polymorphism (SNP) that covered 16 of 27 coding SNPs with linkage disequilibrium (minor allele frequency 0.413). Screening a myospryn polymorphism (K2906N) in a general health check-up of a rural Japanese population revealed an association with cardiac diseases (p=0.0082). In further analysis of the interaction between K2906N and cardiac function in patients, K2906N was associated with the anteroseptal wall thickness of the left ventricle in a recessive model (p=0.0324) and with the ratio of the peak velocity of the early diastolic filling wave to the peak velocity of atrial filling (A/E) (p=0.0278). In an association study based on left ventricular wall thickness, we found a significant difference in the K2906N genotype between controls and patients with cardiac hypertrophy. These results suggest that the K2906N polymorphism could be clinically associated with left ventricular hypertrophy and diastolic dysfunction independent of known parameters. Although the precise mechanism underlying this association remains to be elucidated, treatment with angiotensin II induced an increase in heart myospryn mRNA level in vitro and in vivo. Our results suggest that the polymorphism of myospryn is associated with left ventricular hypertrophy, and an association between a Z-disc protein and cardiac adaptation in response to pressure overload.  相似文献   
10.
In the present study, the results of living donor liver transplantation (LDLT) for 125 hepatocellular carcinoma (HCC) patients were analyzed to determine optimal criteria exceeding the Milan criteria (MC) but still with predictably good outcomes. On the basis of pretransplant imaging studies, 70 patients met the MC, and 55 patients did not. Patients who exceeded the MC but presented with 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