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   6119篇
  免费   395篇
  国内免费   21篇
耳鼻咽喉   47篇
儿科学   188篇
妇产科学   70篇
基础医学   979篇
口腔科学   151篇
临床医学   487篇
内科学   1121篇
皮肤病学   258篇
神经病学   868篇
特种医学   315篇
外科学   455篇
综合类   31篇
一般理论   1篇
预防医学   443篇
眼科学   152篇
药学   440篇
中国医学   13篇
肿瘤学   516篇
  2024年   4篇
  2023年   49篇
  2022年   75篇
  2021年   133篇
  2020年   112篇
  2019年   137篇
  2018年   152篇
  2017年   130篇
  2016年   152篇
  2015年   202篇
  2014年   227篇
  2013年   293篇
  2012年   493篇
  2011年   472篇
  2010年   290篇
  2009年   281篇
  2008年   426篇
  2007年   410篇
  2006年   387篇
  2005年   400篇
  2004年   351篇
  2003年   333篇
  2002年   331篇
  2001年   60篇
  2000年   47篇
  1999年   78篇
  1998年   90篇
  1997年   68篇
  1996年   54篇
  1995年   49篇
  1994年   30篇
  1993年   37篇
  1992年   12篇
  1991年   10篇
  1990年   20篇
  1989年   19篇
  1988年   16篇
  1987年   16篇
  1986年   16篇
  1985年   12篇
  1984年   12篇
  1983年   6篇
  1982年   5篇
  1981年   6篇
  1980年   4篇
  1977年   5篇
  1975年   3篇
  1974年   4篇
  1968年   3篇
  1966年   2篇
排序方式: 共有6535条查询结果,搜索用时 15 毫秒
991.
Objective: The efficacy of a bisoprolol/amlodipine fixed-dose combination (FDC) in patients with essential hypertension who had not responded to bisoprolol or amlodipine monotherapy was investigated.

Research design and methods: In an 18 week, multicenter, randomized, comparative phase III study (ClinicalTrials.gov identifier: NCT01977794), patients with blood pressure uncontrolled by bisoprolol or amlodipine monotherapy (5?mg OD) began treatment with bisoprolol/amlodipine FDC 5/5?mg OD. Patients with controlled blood pressure (BP) at week 6/12 continued at current FDC strength, and patients with uncontrolled BP received FDC dose uptitration (maximum dose: 10/10?mg). The primary efficacy endpoint was change in systolic blood pressure (SBP) at week 18 versus baseline (corresponding to SBP under monotherapy), and secondary endpoints included change from baseline in SBP after week 6/12 and percentage of BP-controlled patients at week 6, 12 and 18. Safety was assessed by number/types of adverse events (AEs).

Results: Two hundred patients were randomized to treatment (100 with uncontrolled BP under bisoprolol and 100 under amlodipine monotherapy). Overall, 196 patients were eligible for analysis. The patient groups displayed similar mean SBP reductions from baseline by study end (bisoprolol monotherapy failure: 25.9?±?12.82?mmHg reduction; amlodipine monotherapy failure: 24.7?±?11.67?mmHg reduction; p?<?0.001 for both). Overall mean SBP decreased by 25.3?±?12.25?mmHg (p?<?0.001). Mean heart rate reductions were also observed (bisoprolol monotherapy failure: 6.6?±?9.67 bpm reduction; amlodipine monotherapy failure: 11.5?±?8.65 bpm reduction; p?<?0.001 for both). Most patients (83.2%) displayed BP control with bisoprolol/amlodipine 5/5?mg at 6 weeks. Treatment was well tolerated at all dose levels; treatment-related AEs (mostly of mild/moderate intensity) were reported by 52.5% of patients, with no severe or serious treatment-related AEs reported. As the study focused on hypertension, total cardiovascular risk was not assessed.

Conclusions: Bisoprolol/amlodipine FDC therapy is associated with significant BP improvements in patients with essential hypertension following monotherapy failure.  相似文献   
992.
993.
994.
995.
Pathogenic variants in the X‐linked gene ZC4H2, which encodes a zinc‐finger protein, cause an infrequently described syndromic form of arthrogryposis multiplex congenita (AMC) with central and peripheral nervous system involvement. We present genetic and detailed phenotypic information on 23 newly identified families and simplex cases that include 19 affected females from 18 families and 14 affected males from nine families. Of note, the 15 females with deleterious de novo ZC4H2 variants presented with phenotypes ranging from mild to severe, and their clinical features overlapped with those seen in affected males. By contrast, of the nine carrier females with inherited ZC4H2 missense variants that were deleterious in affected male relatives, four were symptomatic. We also compared clinical phenotypes with previously published cases of both sexes and provide an overview on 48 males and 57 females from 42 families. The spectrum of ZC4H2 defects comprises novel and recurrent mostly inherited missense variants in affected males, and de novo splicing, frameshift, nonsense, and partial ZC4H2 deletions in affected females. Pathogenicity of two newly identified missense variants was further supported by studies in zebrafish. We propose ZC4H2 as a good candidate for early genetic testing of males and females with a clinical suspicion of fetal hypo‐/akinesia and/or (neurogenic) AMC.  相似文献   
996.
The karyotype is a strong independent prognostic factor in myelodysplastic syndromes (MDS). Since the implementation of the new comprehensive cytogenetic scoring system for MDS, chromosome 7 anomalies are no longer generally assigned to poor risk features but are thoroughly separated. However, der(1;7)(q10;p10), hereinafter der(1;7), is merged into the group labeled “any other single” and belongs to the intermediate risk group, just by definition due to lack of adequate clinical data. The aim of our international collaborative was to clarify the “real” prognostic impact of der(1;7) on a homogenous and well‐documented data base. We performed detailed analysis of 63 MDS patients with isolated der(1;7) constituting the largest cohort hitherto reported. Furthermore, clinical data are compared with those of patients with isolated del(7q) and isolated monosomy 7. Median overall survival (OS) of patients with der(1;7) is 26 months (hazard ratio (HR) 0.91 for del(7q) vs der(1;7) and 2.53 for monosomy 7 vs der(1;7)). The der(1;7) is associated with profound thrombocytopenia most probably causing the reduced OS which is in striking contrast to the low risk for AML transformation (HR 3.89 for del(7q) vs der(1;7) and 5.88 for monosomy 7 vs der(1;7)). Molecular karyotyping indicates that der(1;7) is generated in a single step during mitosis and that a chromosomal imbalance rather than a single disrupted gene accounts for malignancy. Thus, the current cytogenetic scoring system assigning isolated der(1;7) to the intermediate risk group is now confirmed by a sufficient data set.  相似文献   
997.
OBJECTIVE: to study the primary patency rates of angioscopically controlled thromboendarterectomies of the superficial femoral artery. DESIGN: prospective open study. METHODS: between 1990 and 1995, femoropopliteal thromboendarterectomies were performed in 63 patients (41 male, 22 female). Postoperative follow up was performed at 3- to 6-month intervals using non-invasive pressure measurements plus IVDSA at 1 year. RESULTS: eight patients were not evaluable, leaving 55 patients eligible for follow-up analysis. Postoperative complications (arteriovenous fistulas, false aneurysms) were observed in 5.4% of patients. Immediate perioperative occlusions occurred in 7.3%, early occlusions in 21.8% and late occlusions in 16.4% of all cases. The mean follow-up was approximately 57 months. The mean primary patency rate at 5 years was 44.5% (28 patients with the superficial femoral artery still open). Six patients died during the follow-up period. CONCLUSIONS: in contrast to the very positive reports found in recent literature, this prospective study shows a lower five-year patency rate for semi-closed femoropopliteal thromboendarterectomy than for bypass grafting. Thromboendarterectomy cannot be considered as a standard procedure in revascularisation of the femoropopliteal region.  相似文献   
998.
In a patient with nephrotic syndrome, renal biopsy revealed AL amyloid deposits. Monoclonal lambda light chains were identified in serum and urine. A low percentage of monoclonal plasma cells was detected in the bone marrow. The patient received four cycles of VAD and subsequent high-dose chemotherapy (HDCT) with melphalan (200 mg/m2) followed by autologous peripheral blood stem cell transplantation. Proteinuria rapidly diminished during chemotherapy. Three months after HDCT, the patient has no edema, and no signs of plasma cell dyscrasia are currently detectable. Using VAD before starting HDCT may improve the condition of patients with amyloidosis and reduce transplantation-related morbidity and mortality.  相似文献   
999.
The University of North Carolina at Chapel Hill has established an extensive randomized trial to evaluate early treatment of Class-II/1 cases. As presented in this part of the study, a German treatment group was selected in parallel, based on identical prospective criteria, in the context of international cooperation with the Westfälische Wilhelms-Universität, Münster. One essential aspect of this study is the degree to which initially comparable groups can be established by careful alignment of selection criteria and of compilation and analysis of diagnostic records.Nine skeletal analysis parameters initially indicated that it is possible to select very similar though not absolutely identical groups in the context of international cooperation. The further results of the initial 15-month phase comprising functional orthodontic treatment in severe Class-II/1 cases showed significant mandibular effects in both treatment groups (USA UNC, Chapel Hill: modified Balters appliance; Germany WWU Münster: U-bow activator Type I). The groups were compared to a randomized control group with similar untreated malocclusions, established at Chapel Hill (USA UNC, Chapel Hill).  相似文献   
1000.
Hepatitis B viruses specifically target the liver, where they efficiently infect quiescent hepatocytes. Here we show that human and avian hepatitis B viruses can be converted into vectors for liver-directed gene transfer. These vectors allow hepatocyte-specific expression of a green fluorescent protein in vitro and in vivo. Moreover, when used to transduce a type I interferon gene, expression of interferon efficiently suppresses wild-type virus replication in the duck model of hepatitis B virus infection. These data suggest local cytokine production after hepatitis-B-virus-mediated gene transfer as a promising concept for the treatment of acquired liver diseases, including chronic hepatitis B.  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