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   695篇
  免费   56篇
  国内免费   1篇
耳鼻咽喉   2篇
儿科学   12篇
妇产科学   14篇
基础医学   94篇
口腔科学   18篇
临床医学   38篇
内科学   175篇
皮肤病学   4篇
神经病学   54篇
特种医学   20篇
外科学   111篇
综合类   20篇
预防医学   69篇
眼科学   11篇
药学   66篇
中国医学   6篇
肿瘤学   38篇
  2023年   2篇
  2022年   22篇
  2021年   25篇
  2020年   16篇
  2019年   16篇
  2018年   27篇
  2017年   12篇
  2016年   19篇
  2015年   23篇
  2014年   37篇
  2013年   20篇
  2012年   35篇
  2011年   41篇
  2010年   33篇
  2009年   20篇
  2008年   41篇
  2007年   35篇
  2006年   32篇
  2005年   43篇
  2004年   36篇
  2003年   25篇
  2002年   25篇
  2001年   22篇
  2000年   16篇
  1999年   15篇
  1998年   8篇
  1997年   2篇
  1996年   5篇
  1994年   4篇
  1993年   7篇
  1992年   5篇
  1991年   11篇
  1990年   10篇
  1989年   7篇
  1988年   3篇
  1987年   3篇
  1986年   7篇
  1985年   10篇
  1984年   3篇
  1983年   2篇
  1981年   2篇
  1977年   2篇
  1976年   4篇
  1974年   3篇
  1973年   3篇
  1971年   1篇
  1970年   1篇
  1969年   4篇
  1966年   1篇
  1945年   1篇
排序方式: 共有752条查询结果,搜索用时 15 毫秒
51.
Transjugular intrahepatic cavoportal shunt for Budd-Chiari syndrome   总被引:1,自引:0,他引:1  
Budd-Chiari syndrome (BCS) is characterized by obstruction of the hepatic venous outflow tract. Therapeutic options for BCS are limited. We report a case of a 21-year-old woman with protein S and C deficiency with gross ascites. Treatment with transjugular intrahepatic portosystemic shunt (TIPS) was attempted, which revealed occluded hepatic veins, so transcaval TIPS was performed. No serious procedure-related complication occurred. After successful shunt creation, the patient's symptoms subsided and she was discharged and followed up for 6 months.  相似文献   
52.
53.
An estimated 400,000 infant and 16,500 maternal deaths occur annually in Pakistan. These translate into an infant mortality rate and maternal mortality ratio that should be unacceptable to any state. Disease states including communicable diseases and reproductive health (RH) problems, which are largely preventable account for over 50% of the disease burden. The analysis of Pakistan's maternal and child health (MCH) and family planning (FP) policy covers the period 1990-2002, and focuses on macroeconomic influences, priority programs and gaps, adequacy of resources, equity and organizational aspects, and the process of policy formulation. The overall MCH/FP policy is well directed. MCH/FP has been a priority in all policies; resource allocation, although unacceptably low, has substantially increased during the last decade; and there is a progressive shift from MCH to the reproductive health (RH) agenda. Areas in need of improvement include greater use of evidence as a basis for policy; increased priority to nutrition programs, measures to reduce neonatal and perinatal mortality, provision of emergency obstetric care, availability of skilled birth attendants, and a clear policy on integrated management of childhood illnesses. Enhanced planning capacity, development of a balanced human resource, improved governance to reduce staff absenteeism and frequent transfers, and a greater role of the private sector in the provision of services are some organizational aspects that need the governments' consideration. There are several lessons to be learnt: (i) Ministries of Health need sustained stewardship and well-documented evidence to protect cuts in resource allocation; (ii) frequent policy announcement sends inappropriate signals to managers and weakens on-going implementation; (iii) MCH/FP policies unless informed by evidence and participation of interest groups are unlikely to address gaps in programs; (iv) distributional and equity objectives of MCH/FP be addressed while setting overall national goals; (v) institutional capacity is a vital ingredient in translating MCH/FP policies into effective services. The suggested strategic directions emphasize, among others, the need for a comprehensive MCH/FP framework; strengthened stewardship in ministry of health, cost-effective strategies to address the gaps identified and doubling of the public sector resource allocation to MCH/FP over the next 5 years. The ability to ensure delivery of quality health services remains the biggest challenge in the Pakistani health sector. Unless sound policies are backed by well-functioning programs they are likely to become a victim of poor implementation.  相似文献   
54.
Mycobacterium leprae, the causative agent of leprosy resides and multiplies within the host monocytes and macrophages, thereby evading host immune system. Cell-mediated immune response (CMI) plays a vital role as evidenced from the high CMI in BT/TT (borderline and tuberculoid) patients and conversely low in BL/LL (borderline and lepromatous) patients. In the present study, an attempt was made to immunomodulate the anergized T cells of lepromatous leprosy patients by presenting the mycobacterial antigen in combination with T cell adjuvant, murabutide (active analog of muramyl' dipeptide, MDP-BE) and a Trat peptide (T cell epitope of Integral membrane protein (Trat) from Escherichia coli) in particulate form (liposomes) or soluble form (media). PBMNC of normal, BT/TT and BL/LL were stimulated in vitro with five mycobacterial antigens (Ag) in the following formulations, Ag, Ag+murabutide, Ag+murabutide+Trat peptide either in liposomes or in medium. All the five antigen(s) when delivered in liposomes containing murabutide and Trat peptide showed a very high lymphoproliferative response (p<0.001) in all the three groups. IFN-gamma and IL-2 were significantly (p<0.001) high in these culture supernatants compared to IL-10 and IL-4 confirming a shift from CD4+Th2 to Th1 response in leprosy patients with particulate mode of antigen presentation. Interestingly, PBMNC derived from lepromatous patients also showed consistent T cell proliferation with all the formulations. Further, the mechanism of liposomal processing of antigens was studied using different inhibitors that interfere at different stages of antigen presentation. Results indicate that this study may pave way for an immunotherapeutic approach for reverting the anergic T cells of lepromatous patients to proliferating T cells with the release of Th1 cytokines thereby restoring the CMI response in these patients.  相似文献   
55.
In the use of sub-unit vaccines, it is important to identify the protective epitopes and to generate the optimal immune response by using appropriate immuno-modulatory adjuvants and/or delivery systems. The main aim of the present study was to generate an MHC-non-restricted immune response against one promising vaccine candidate, the circumsporozoite protein (CSP) of Plasmodium vivax. Four synthetic peptides were chosen: three repeat-region sequences (AA, DA and ANG) and a putative T-cell epitope extended from a conserved region (region II) containing a hepatocyte-binding region (HBP). The humoral response against each peptide was studied in outbred mice and three strains of inbred mice (with different genetic backgrounds). Delivery of each peptide in microspheres or inclusion of a bio-active casein-fragment analogue as adjuvant with alum/liposome delivery considerably enhanced the humoral response against the peptide (when compared with the response to the peptide delivered in alum alone). The maximal immune response was observed when the peptide was delivered in microspheres, with no booster doses required; the antibodies raised against peptide delivered with adjuvant or in modulatory delivery vehicles had two-to five-fold lower binding affinities. The predominant IgG isotypes elicited using microspheres or adjuvant with alum/liposome delivery were IgG(2a)/IgG(2b) and/or IgG(1). Importantly, conjugation of HBP to the B-cell repeat peptides increased the titres of peptide-specific antibodies, especially of antibodies against the supposedly cryptic HBP. Delivery of a mix of all four peptides in microspheres elicited an intense immune response in outbred mice, indicating that such a delivery system efficiently presents the peptides to the immune effector cells. That antibodies in the anti-peptide sera bound strongly to air-dried sporozoites of P. vivax was confirmed by immunofluorescence. The present results, based on the use of individual peptides or a conjugate or cocktail of the peptides, highlight the utility of the casein-fragment analogue as an adjuvant, when used with alum/liposome delivery, and also demonstrate the potential of microspheres as a single-shot delivery system for sub-unit peptides.  相似文献   
56.
57.
Two cases of retrocaval ureter are reported. A 22 years old male patient presented to us with the complaints of right flank pain and hematuria and a child of 2 years referred to us for evaluation of right side moderate hydronephrosis detected on ultrasound. The diagnosis was confirmed on intravenous urography and retrograde pyelography. Both the ends were transected and anastomosed above a JJ stent in front of the inferior vena cava. Postoperatively the patients remained asymptomatic and the hydronephrosis improved.  相似文献   
58.
59.
Most recent guidelines advise targeting of lipid lowering for primary prevention at those at high absolute coronary (CHD) risk. We compared the accuracy of five CHD risk assessment methods in identifying such patients: one based on total cholesterol > or = 6.5 mmol/l plus two risk factors, and four based on the Framingham risk function (the European Task Force chart and Sheffield table, both using total cholesterol and the New Zealand chart and modified Sheffield table, both using total: HDL cholesterol ratio) for predicting CHD event risk > or = 2% per year, calculated by an independent risk function, PROCAM, in 126 treated hypertensive men. Cholesterol threshold plus two risk factors had sensitivity 59% and specificity 63%, did not identify some very high-risk patients, and identified very low-risk patients. Framingham-based methods using total cholesterol alone had sensitivity 90-98% and specificity 37-43%, and identified high-risk patients well, but identified some patients at very low risk. Methods based on total: HDL cholesterol ratio had sensitivity 90-98% and specificity 60-63%, and did not identify incorrectly patients at very low CHD risk. Methods based on cholesterol threshold and counting of risk factors are too inaccurate for targeting drug therapy for primary prevention of CHD. Framingham-based methods should incorporate HDL-cholesterol as the total: HDL cholesterol ratio.  相似文献   
60.
This study was designed to evaluate the efficacy and toxicity of dose intensifying DHAP (dexamethasone, cytarabine and cisplatin) salvage chemotherapy by adding mitoxantrone with GM-GSF support in patients with relapsed or refractory non-Hodgkin's lymphoma (NHL). From March 1992 to January 1995, 22 patients with intermediate and high grade (aggressive) NHL refractory or relapsed after adriamycin containing chemotherapy regimens were treated with M-DHAP+GM-CSF, (dexamethasone 40 mg i.v. days 1-4, cisplatin 100 mg/m2 i.v. by continuous infusion over 24 hours on day 1, cytarabine 2 gm/m2, i.v. every 12 hours for 2 doses on day 2, mitoxantrone 10 mg/m2 i.v. on days 3 and 4 and GM-CSF 250-500 microg/m2 s.c. daily beginning day 5 until absolute neutrophil count recovery. Most patients had poor prognostic factors including primary refractory disease (18/22), bulky disease (12/22), elevated LDH (9/22), or bone marrow involvement (8/22). All 22 patients were evaluable. The overall response rate was 41% (CR 23% and PR 18%). There were three toxic deaths, all related to sepsis. Median progression free survival (PFS) and overall survival (OS) rates were 5.2 months and 11.8 months respectively. At the same time of the analysis two patients were alive after high-dose therapy and bone marrow transplant at 34 and 36 months follow-up and two were alive with disease. The maximal acceptable dosage of mitoxantrone was 10 mg/m2 x 2 due to serious hematologic toxicity. Treatment delays and dose reductions compromised delivering the optimal dose intensity of M-DHAP. A poor prognostic group of patients with refractory or recurrent aggressive lymphoma, many of whom were not eligible for high-dose therapy and stem cell transplantation were treated with repeated cycles of dose intensified DHAP with growth factor support. Although M-DHAP had therapeutic activity even in patients considered to have primary refractory disease, myelosuppression was dose limiting and frequently limited the number of cycles. Therefore, if M-DHAP is to be further evaluated, therapeutic results may be improved further by incorporating strategies to reduce myelotoxicity such as the use of growth factors to reduce platelet transfusion requirements or the use of autologous stem cell support after each cycle.  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