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   10548篇
  免费   644篇
  国内免费   74篇
耳鼻咽喉   47篇
儿科学   261篇
妇产科学   210篇
基础医学   1587篇
口腔科学   201篇
临床医学   841篇
内科学   2864篇
皮肤病学   86篇
神经病学   918篇
特种医学   525篇
外科学   1528篇
综合类   25篇
一般理论   4篇
预防医学   405篇
眼科学   108篇
药学   493篇
中国医学   39篇
肿瘤学   1124篇
  2023年   56篇
  2022年   62篇
  2021年   226篇
  2020年   129篇
  2019年   200篇
  2018年   259篇
  2017年   201篇
  2016年   259篇
  2015年   262篇
  2014年   388篇
  2013年   483篇
  2012年   831篇
  2011年   833篇
  2010年   468篇
  2009年   412篇
  2008年   730篇
  2007年   769篇
  2006年   737篇
  2005年   730篇
  2004年   670篇
  2003年   682篇
  2002年   585篇
  2001年   92篇
  2000年   82篇
  1999年   92篇
  1998年   119篇
  1997年   72篇
  1996年   62篇
  1995年   76篇
  1994年   61篇
  1993年   46篇
  1992年   30篇
  1991年   57篇
  1990年   33篇
  1989年   32篇
  1988年   40篇
  1987年   25篇
  1986年   24篇
  1985年   24篇
  1984年   33篇
  1983年   27篇
  1982年   32篇
  1981年   28篇
  1980年   18篇
  1979年   13篇
  1978年   10篇
  1977年   12篇
  1974年   16篇
  1973年   15篇
  1971年   9篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
Trauma und Berufskrankheit - Unfälle stellen zwischen dem 1. und 20. Lebensjahr die häufigste Todesursache dar, wobei in bis zu 5 % der Fälle das Abdomen beteiligt ist. Beim...  相似文献   
63.
BackgroundMeniscal injury is currently a well-recognized source of knee dysfunction. While it would be ideal to repair all meniscus tears, the failure rate is significantly high, although it may be reduced by careful selection of the patients. Our objective was to assess the outcome of meniscal repair surgery and the role of simultaneous reconstruction of the anterior cruciate ligament (ACL).Results136 Meniscal repairs were performed in 122 patients with a mean age of 26.8 years. Mean follow-up duration was 9 months. 63 % of the patients underwent medial and 37 % underwent lateral meniscal repair, with failure rates of 19 % for medial and 12 % for lateral menisci. Ligament injuries were found in 61 % of the patients (n = 83). Failure of meniscal repair occurred in 14.5 % (n = 12) of the patients who had early ACL reconstruction and in 27 % (n = 22) of the patients who had delayed ACL reconstruction (p = 0.0006). The failure rate was found to be 13 % in patients who were younger than 25 years (61 %) and 15 % in patients who were older than 25 years (39 %).ConclusionThe success rate of meniscal repair was found to be significantly better when ACL reconstruction was performed simultaneously with meniscal repair.

Level of evidence

Level IV.  相似文献   
64.

Background and purpose

Most studies on total ankle replacement (TAR) have used a case mix of patients. We evaluated the outcome of TAR performed for end-stage arthritis either because of fracture or ligamentous injury.

Patients and methods

We prospectively followed 88 consecutive patients (50 postfracture ankles and 40 ankles with instability arthritis (2 bilateral)) who underwent TAR between 2001 and 2009. Mean follow-up for both groups was 5 years.

Results

Preoperative varus deformity of 10° or more was present in 23 ankles in the instability group. At 6 years, survival with revision or salvage fusion as an endpoint was 87% (95% CI: 74–99) in the postfracture group and 79% (95% CI: 63–94) in the instability group. Progressive periprosthetic osteolysis was seen in 23 ankles, and required salvage fusion in 6. The number of reoperations was similar in both groups. Clinical outcome, as assessed with 2 ankle scores and 2 questionnaires, showed good results and was similar at the latest follow-up.

Interpretation

The outcome was similar in the postfracture and instability groups and also similar to that reported in series including a case mix of patients. In contrast to earlier reports, preoperative frontal plane deformity in this series was not identified as a risk factor for failure.Most published articles on total ankle replacement (TAR) have presented results from mixed cohorts of patients suffering from end-stage ankle arthritis of several different etiologies, such as posttraumatic arthritis, primary arthritis, and rheumatoid arthritis (Buechel et al. 2003, Wood et al. 2008, Bonnin et al. 2011, Rippstein et al. 2011, Barg et al. 2013, Zaidi et al. 2013). To our knowledge, there have been no studies on TAR concentrating exclusively on patients withposttraumatic arthritis, but some studies have focused on TAR in combined cohorts of posttraumatic and primary osteoarthritis (Saltzman et al. 2010, Bai et al. 2010, Flavin et al. 2013).This is surprising, as posttraumatic arthritis is considered to be the most frequent cause of ankle arthritis (Saltzman et al. 2005).2 subgroups of posttraumatic arthritis should be distinguished: (1) postfracture arthritis, secondary to an intra- or juxta-articular fracture; and (2) ligamentous posttraumatic arthritis, secondary to a single severe ankle sprain or as a result of recurrent or chronic instability (Valderrabano et al. 2009). We refer to the latter as instability arthritis. Patients suffering from end-stage instability arthritis frequently present with a varus deformity of the ankle as a result of both lateral ligament laxity and asymmetric cartilage loss medially (Harrington 1979, Doets et al. 2008, Ryssman and Myerson 2011).We evaluated the medium-term outcome of TAR for end-stage posttraumatic ankle arthritis and compared it for postfracture arthritis and for instability arthritis. Our research questions were whether patients treated with TAR for instability arthritis—as they more frequently have a deformity and perhaps also residual instability after TAR—will have worse results with respect to (1) implant survival, (2) the number of reoperations, and (3) ankle-specific and general patient- and physician-based outcomes.  相似文献   
65.
Bronchiolitis is the first lower respiratory tract viral infection manifesting in infants younger than 12 months of age. Our aim was to evaluate clinical and serological differences in infants with bronchiolitis from a single or from multiple viruses. Our secondary aim was to investigate differences in recurrent wheezing episodes after 12‐24‐36 months of follow‐up. We reviewed the clinical records for 486 full‐term infants hospitalized for bronchiolitis with at least one virus detected in the nasopharyngeal aspirate. In 431 (88.7%) patients one virus was detected and in 55 (11.3%) infants more than one virus was found. No differences were observed in the length of hospitalization, clinical severity score, O2 supplementation or admission to the intensive care unit. Single virus was associated with higher serum C‐reactive protein (C‐RP) than infants with multiple viruses and higher blood neutrophil counts. Respiratory syncytial virus (RSV) was the most frequently detected virus. RSV alone was associated with higher C‐RP (P = 0.007), compared to RSV coinfection. Infants with human rhinovirus (hRV) alone had higher white blood cell counts, higher blood neutrophils, and higher serum C‐RP levels than hRV co‐infection (P = 0.029, P = 0.008, P = 0.008). RSV + hRV, the most frequent co‐infection, was associated with lower neutrophil count and lower C‐RP levels (P = 0.008, P = 0.016) and less fever (P = 0.012), when comparing RSV versus hRV versus RSV + hRV. No differences were found in the frequency of recurrent wheezing between single versus multiple viruses after bronchiolitis. Our findings suggest that in infants with bronchiolitis multiple viral co‐infections can occur, without influence in the clinical severity of the disease. Infants with co‐infection seems to mount a lower inflammatory response.
  相似文献   
66.
The presence of inflammation and demyelination in a central nervous system (CNS) biopsy points towards a limited, yet heterogeneous group of pathologies, of which multiple sclerosis (MS) represents one of the principal considerations. Inflammatory demyelination has also been reported in patients with clinically suspected primary central nervous system lymphoma (PCNSL), especially when steroids had been administered prior to biopsy acquisition. The histopathological changes induced by corticosteroid treatment can range from mild reduction to complete disappearance of lymphoma cells. It has been proposed that in the absence of neoplastic B cells, these biopsies are indistinguishable from MS, yet despite the clinical relevance, no histological studies have specifically compared the two entities. In this work, we analyzed CNS biopsies from eight patients with inflammatory demyelination in whom PCNSL was later histologically confirmed, and compared them with nine well defined early active multiple sclerosis lesions. In the patients with steroid‐treated PCNSL (ST‐PCNSL) the interval between first and second biopsy ranged from 3 to 32 weeks; all of the patients had received corticosteroids before the first, but not the second biopsy. ST‐PCNSL patients were older than MS patients (mean age: ST‐PCNSL: 62 ± 4 years, MS: 30 ± 2 years), and histological analysis revealed numerous apoptoses, patchy and incomplete rather than confluent and complete demyelination and a fuzzy lesion edge. The loss of Luxol fast blue histochemistry was more profound than that of myelin proteins in immunohistochemistry, and T cell infiltration in ST‐PCNSL exceeded that in MS by around fivefold (P = 0.005). Our data indicate that in the presence of extensive inflammation and incomplete, inhomogeneous demyelination, the neuropathologist should refrain from primarily considering autoimmune inflammatory demyelination and, even in the absence of lymphoma cells, instigate close clinical follow‐up of the patient to detect recurrent lymphoma.  相似文献   
67.
Allogeneic hematopoietic stem cell transplantation (alloHCT) is offered increasingly to elderly patients with hematologic malignancies. However, outcome data in those who are 70 years or older are limited, and no standard conditioning regimen has been established for this population. In this retrospective study we evaluated the outcome of 53 consecutive patients aged 70 years and older who underwent alloHCT with melphalan-based reduced-intensity conditioning (RIC) at City of Hope. Engraftment was prompt, with median time to neutrophil engraftment of 15 days. More than 95% of patients achieved complete donor chimerism within 6 weeks from HCT, consistent with the “semiablative” nature of this regimen. With a median follow-up of 31.1 months, the 2-year overall survival (OS), progression-free survival (PFS), and nonrelapse mortality (NRM) were 68.9%, 63.8%, and 17.0%, respectively. Cumulative incidence of relapse at 1 and 2 years was 17.0% and 19.3%, respectively. One hundred–day cumulative incidence of grades II to IV acute graft-versus-host disease was 37.7% (grades III to IV, 18.9%), and 2-year cumulative incidence of chronic graft-versus-host disease was 61.9% (extensive, 45.9%). The only significant predictor for poor OS was high/very high disease risk index. Transplant-related complications and morbidities observed here did not differ from the commonly expected in younger patients treated with RIC. In conclusion, alloHCT with a melphalan-based conditioning regimen is associated with acceptable toxicities and NRM, lower incidence of relapse, and favorable OS and PFS in patients aged 70 years or older.  相似文献   
68.
Overexpression of the Wilms' tumor 1 (WT1) gene is informative in many patients with acute myelogenous leukemia (AML) and myelodysplastic syndromes (MDS) and is measurable in peripheral blood (PB). Despite these advantages, WT1 has not broadly been established as a marker for minimal residual disease (MRD) monitoring after allogeneic hematopoietic stem cell transplantation (allo-HSCT) due to limited patient numbers, differing sample sources, and nonstandardized in-house methods. To estimate the value of WT1 as an MRD marker, we serially quantified PB WT1 expression using a standardized European LeukemiaNet-certified assay in 59 patients with AML and MDS after allo-HSCT. We compared its performance with routine methods such as chimerism, XY-fluorescence in situ hybridization (FISH), disease-specific cytogenetic, and molecular analyses, which were accessible in 100%, 34%, 68%, and 37%, respectively. Twenty-four patients (41%) relapsed within a median of 126 days after allo-HSCT, and 20 of them showed at least 1 elevated WT1 value above the validated cutoff. The other 35 patients (59%) remained in complete remission, and only 1 patient had a transient increase in WT1 expression. This reflects a sensitivity of 83% and a specificity of 97% for WT1 and appears to be favorable compared with the sensitivities and specificities observed for chimerism (33% and 91%), XY-FISH (67% and 73%), cytogenetic (33% and 77%), and molecular (78% and 85%) analyses. Further supporting its predictive impact, elevated WT1 expression prompted an earlier BM biopsy and consecutively the diagnosis of relapse in 62% of patients. The results of this real-life experience imply that PB WT1 expression is measurable by a standardized assay and predicts imminent relapse after allo-HSCT with high sensitivity and specificity in most patients with AML and MDS.  相似文献   
69.
70.
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