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   1434篇
  免费   68篇
  国内免费   4篇
耳鼻咽喉   17篇
儿科学   105篇
妇产科学   27篇
基础医学   206篇
口腔科学   28篇
临床医学   152篇
内科学   231篇
皮肤病学   25篇
神经病学   75篇
特种医学   45篇
外国民族医学   1篇
外科学   120篇
综合类   37篇
一般理论   1篇
预防医学   106篇
眼科学   69篇
药学   127篇
中国医学   7篇
肿瘤学   127篇
  2023年   13篇
  2022年   39篇
  2021年   68篇
  2020年   33篇
  2019年   50篇
  2018年   46篇
  2017年   36篇
  2016年   47篇
  2015年   53篇
  2014年   73篇
  2013年   96篇
  2012年   139篇
  2011年   122篇
  2010年   64篇
  2009年   42篇
  2008年   90篇
  2007年   93篇
  2006年   79篇
  2005年   56篇
  2004年   77篇
  2003年   51篇
  2002年   62篇
  2001年   9篇
  2000年   5篇
  1999年   7篇
  1998年   10篇
  1997年   5篇
  1996年   3篇
  1995年   1篇
  1994年   4篇
  1993年   6篇
  1992年   2篇
  1991年   1篇
  1990年   1篇
  1989年   5篇
  1988年   2篇
  1987年   4篇
  1984年   1篇
  1983年   2篇
  1981年   2篇
  1980年   2篇
  1977年   1篇
  1948年   1篇
  1930年   1篇
  1929年   1篇
  1922年   1篇
排序方式: 共有1506条查询结果,搜索用时 15 毫秒
61.
Halpin RJ  Bendok BR  Sato KT  Liu JC  Patel JD  Rosen ST 《Surgical neurology》2005,63(5):469-74; discussion 474-5
BACKGROUND: We describe a case of vertebral metastases treated with a combination of percutaneous radiofrequency ablation (RFA) and vertebroplasty in a single session. CASE DESCRIPTION: A 45-year-old female with recently diagnosed metastatic non-small cell lung cancer was referred for consideration of vertebroplasty after having several weeks of back pain. Computed tomography and magnetic resonance imaging scans of the thoracic spine revealed metastatic lesions at the T9 and T12 bodies. Radiofrequency ablation was performed using a starburst array electrode (Rita Medical Systems, Mountain View, Calif). The metastatic lesion in the T9 vertebral body measured 1.5 x 1.5 cm and was heated to 100 degrees C for 5 minutes. Vertebroplasty was then performed on this lesion as well as a lesion at T12 with no complications. The patient was discharged home the same day without complaints. CONCLUSION: Radiofrequency ablation and vertebroplasty are minimally invasive procedures that can be used in combination to treat spinal metastases. The pain relief from these treatments is often immediate. RFA can also be used to minimize procedure-related complications during the vertebroplasty. In properly selected patients, RFA may also increase the duration of local spinal stabilization afforded by the vertebroplasty alone. Long-term studies are warranted to assess the efficacy and durability of this unique approach.  相似文献   
62.
63.
This study is based on modeling the anti-malarial activity (log IC50/nm) of 20 cyclic peroxy ketals using topological and physicochemical parameters. The multiple regression analysis reveals that the five-parametric model containing MW, ST, χ eq, 0 χ v, IP2 as correlating parameters is the best for modeling the activity of the compounds under present study. The cross-validated parameters have been calculated by LOO cross-validation procedure for validation of proposed model.  相似文献   
64.
65.
66.
Immunohistochemical staining was performed on 145 biopsies with a diagnosis of undifferentiated or poorly differentiated tumor in order to classify them into lymphoid, epithelial, or mesenchymal in origin. It was possible to arrive at a histogenetic diagnosis on immunostaining in 85.5% of cases. Immunostaining confirmed the diagnosis in 32.4% and contributed to diagnosis in 53.1%. Malignant lymphoma was the most common diagnosis (35.9%), followed by carcinoma (23.4%). A panel of antibodies consisting of anti-common leucocyte antigen (LCA), anti-epithelial membrane antigen (EMA), anti-cytokeratin (CK), anti-low to intermediate molecular weight cytokeratin (CAM 5.2), anti-S-100 protein (S-100), and anti-vimentin (VM) may resolve, to a large extent, some of the common diagnostic problems. © 1994 Wiley-Liss, Inc.  相似文献   
67.
Urotensin-II (U-II) and its receptor (UT) represent novel therapeutic targets for management of a variety of cardiovascular diseases. To test such hypothesis, it will be necessary to develop experimental animal models for the manipulation of U-II/UT receptor system. The goal of this study was to clone mouse and primate preproU-II and UT for pharmacological profiling. Monkey and mouse preproU-II genes were identified to encode 123 and 125 amino acids. Monkey and mouse UT receptors were 389, and 386 amino acids, respectively. Genomic organization of mouse genes showed that the preproU-II has four exons, while the UT receptor has one exon. Although initially viewed by many exclusively as cardiovascular targets, the present study demonstrates expression of mouse and monkey U-II/UT receptor mRNA in extra-vascular tissue including lung, pancreas, skeletal muscle, kidney and liver. Ligand binding studies showed that [125I]h U-II bound to a single sites to the cloned receptors in a saturable/high affinity manner (Kd 654+/-154 and 214+/-65 pM and Bmax of 1011+/-125 and 497+/-68 fmol mg-1 for mouse and monkey UT receptors, respectively). Competition binding analysis demonstrated equipotent, high affinity binding of numerous mammalian, amphibian and piscine U-II isopeptides to these receptors (Ki=0.8 - 3 nM). Fluorescein isothiocyanate (FITC) labelled U-II, bound specifically to HEK-293 cells expressing mouse or monkey UT receptor, confirming cell surface expression of recombinant UT receptor. Exposure of these cells to human U-II resulted in an increase in intracellular [Ca2+] concentrations (EC50 3.2+/-0.8 and 1.1+/-0.3 nM for mouse and monkey UT receptors, respectively) and inositol phosphate (Ip) formation (EC50 7.2+/-1.8 and 0.9+/-0.2 nM for mouse and monkey UT receptors, respectively) consistent with the primary signalling pathway for UT receptor involving phospholipase C activation.  相似文献   
68.
In patients with multiple myeloma, a good complete response rate and disease-free survival may be achieved with sequential chemotherapy using VAD and VMCP, which is an alternative effective and less expensive treatment regimen. This regimen thus assumes particular significance in developing nations like India, where the majority of patients with myeloma cannot afford the cost of high-dose chemotherapy with stem cell rescue.  相似文献   
69.
Kala-azar is an endemic, disease in many parts of India. Traditionally diagnosis of this disease was based on demonstrating the parasites in various tissues like bone marrow or splenic aspirates. However, lack of high sensitivity of these methods led to the use of various immunodiagnostic methods in the diagnosis of kala-azar. Antigen detection and polymerase chain reaction to detect parasitic DNA have been found to be useful in patients with an underlying immunosuppressive disease like AIDS. For treating kala-azar, pentavalent antimonial compounds are still the first-line agents. However, due to increasing resistance to this agent, many patients at present requie other drugs including amphotericin B and pentamidine. Toxic effects of these second-line agents have led to development of drug dellvery systems like liposomal amphotericin B, which has shown uniform efficacy in clinical trials. Combining stibogluconate with either paromomycin or interferon-γ has also been shown to be useful in many patients with drug-resistant kala-azar.  相似文献   
70.
High-dose methotrexate (HDMTX) is used increasingly to treat children with central nervous system (CNS) tumours. Although the neuro-imaging features of leukoencephalopathy associated with systemic or intrathecal methotrexate administered after cranial radiation have been well described, the extent to which the sequencing of HDMTX prior to cranial radiation in infants and children predisposes to late neuroradiological features of leukoencephalopathy is unknown. This report describes the National Cancer Institute (NCI) toxicity grade of leukoencephalopathy based on magnetic resonance imaging (MRI) findings in all patients who survived 4 or more years after treatment on an earlier phase II study. These patients, with newly diagnosed CNS embryonal tumours, were in the age range 3.5-14.2 years (median 6.9 years) at diagnosis, and received four courses of pre-irradiation combination chemotherapy, including HDMTX 8 g/m(2). Following completion of the 'up-front' phase II study, all patients received conventionally fractionated whole brain doses of 36-50.4 Gy. The radiation dose and treatment volumes were determined individually according to the primary tumour location and results of extent of disease evaluations. The most recent MRI brain scans, obtained 4.0-10.5 years (median 6.5 years) after radiation therapy and comprising a minimum of T1, T1 following gadolinium and T2 sequences, were reviewed centrally to assess the neuroradiological grade of leukoencephalopathy, based on the NCI Common Terminology Criteria for Adverse Events, v3.0. Grade I changes (mild increase in subarachnoid space, and/or mild ventriculomegaly, and/or small/focal T2 hyperintensities) were evident in 8 of the 12 patients and grade II changes (moderate increase in subarachnoid space and/or moderate ventriculomegaly, and/or focal T2 hyperintensities extending to the centrum ovale) were found in the remaining 4. In conclusion, treatment with multiple courses of HDMTX prior to 36-50.4 Gy cranial radiation did not result in moderate to severe MRI features of leukoencephalopathy. Future studies in paediatric neuro-oncology patients, involving HDMTX combined with prospective neuropsychological evaluations appear justified.  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