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   757篇
  免费   48篇
  国内免费   27篇
耳鼻咽喉   1篇
儿科学   42篇
妇产科学   9篇
基础医学   63篇
口腔科学   29篇
临床医学   71篇
内科学   167篇
皮肤病学   21篇
神经病学   23篇
特种医学   115篇
外科学   107篇
综合类   11篇
预防医学   44篇
眼科学   2篇
药学   44篇
中国医学   2篇
肿瘤学   81篇
  2023年   18篇
  2022年   7篇
  2021年   4篇
  2020年   7篇
  2019年   19篇
  2018年   17篇
  2017年   13篇
  2016年   13篇
  2015年   17篇
  2014年   12篇
  2013年   43篇
  2012年   13篇
  2011年   27篇
  2010年   29篇
  2009年   32篇
  2008年   24篇
  2007年   24篇
  2006年   17篇
  2005年   22篇
  2004年   26篇
  2003年   11篇
  2002年   13篇
  2001年   12篇
  2000年   11篇
  1999年   15篇
  1998年   30篇
  1997年   32篇
  1996年   29篇
  1995年   30篇
  1994年   28篇
  1993年   20篇
  1992年   14篇
  1991年   7篇
  1990年   14篇
  1989年   20篇
  1988年   20篇
  1987年   15篇
  1986年   21篇
  1985年   14篇
  1984年   6篇
  1983年   9篇
  1982年   17篇
  1981年   15篇
  1980年   8篇
  1979年   7篇
  1978年   5篇
  1977年   3篇
  1976年   4篇
  1975年   9篇
  1969年   2篇
排序方式: 共有832条查询结果,搜索用时 218 毫秒
51.
Clinical pharmacology of GW280430A in humans   总被引:11,自引:0,他引:11  
BACKGROUND: An ultrashort-acting nondepolarizing neuromuscular blocking agent that could be an alternative to succinylcholine has been the focus of a concerted effort in the field of muscle relaxants. GW280430A showed a promising pharmacodynamic profile in preclinical work and a wide margin of safety and so was selected for study in humans. METHODS: Thirty-one volunteers participated in this study, which determined the dose producing 95% block (ED95) and the safety and pharmacodynamics of increasing ED95 multiples. Anesthesia was induced and maintained with propofol, midazolam, and fentanyl. Neuromuscular transmission was measured at the adductor pollicis using ulnar nerve stimulation, and responses were recorded continuously by standard mechanomyographic monitoring. RESULTS: The ED95 for GW280430A is 0.19 mg/kg. The time to onset of 90% block ranged from 1.3 to 2.1 min, depending on the dose. Clinical durations ranged from 4.7 to 10.1 min and increased with increasing dose. Five to 95% and 25-75% recovery rates were approximately 7 and 3 min, respectively, and were independent of the dose administered. Transient cardiovascular side effects were observed at doses beginning at 3 x ED95 and above and were suggestive of histamine release. Most volunteers receiving 4 x ED95 exhibited plasma histamine concentrations indicative of significant histamine release. CONCLUSIONS: GW280430A has a rapid onset and ultrashort duration of action. The recovery rate is rapid, predictable, and independent of dose. Doses at least up to 2.5 x ED95 seem to be free of side effects and seem to be able to provide relaxation within 60-90 s.  相似文献   
52.
Background Patients with prostate cancer with a pre-operative prostate-specific antigen (PSA) τ;15ng/ml who undergo radical retropubic prostatectomy (RRP) generally do not have a good outcome, yet may have organ-confined cancer and should be offered the option of surgery. Aim To assess the outcome of patients who underwent RRP with a pre-operative PSA ≥ 15ng/ml. Methods Thirty-four patients, mean pre-operative PSA: 25.46ng/ml (15.03–76.6) and mean Gleason score: 6.4 (5–9) were assessed. Results Two groups were identified. Group I: 41% (14/34) have no biochemical recurrence to mean follow up of 58 months (30–106). Mean PSA: 18.8ng/ml (15.03–25.84). Mean Gleason score: 6.1 (5–7). Clinical stage: T1c in 80%. No patient had seminal vesicle or lymph node involvement. Group II: 59% (20/34) have biochemical recurrence or died (3) from their disease to mean follow up of 66 months (36–98). Mean PSA: 28.9ng/ml (15.28–76.6). Mean Gleason score: 6.7 (5–9). Clinical stage: T1c in 25%. Eleven patients had seminal vesicle (8) involvement or positive lymph nodes (3) or both (2). Conclusion RRP seems feasible in patients whose pre-operative PSA is between 15 and 25ng/ml with stage T1c, Gleason score ≤ 7 and negative lymph node frozen section.  相似文献   
53.
Prevention of chemotherapy and radiation toxicity with glutamine   总被引:19,自引:0,他引:19  
GOALS OF THE WORK: Malignancy produces a state of physiologic stress that is characterized by a relative deficiency of glutamine, a condition that is further exacerbated by the effects of cancer treatment. Glutamine deficiency may impact on normal tissue tolerance to antitumor treatment, and may lead to dose reductions and compromised treatment outcome. Providing supplemental glutamine during cancer treatment has the potential to abrogate treatment-related toxicity. We reviewed the available data on the use of glutamine to decrease the incidence and severity of adverse effects due to chemotherapy and/or radiation in cancer patients. METHODS: We performed a search of the MEDLINE database during the time period 1980-2003, and reviewed the English language literature of both human and animal studies pertaining to the use of glutamine in subjects with cancer. We also manually searched the bibliographies of published articles for relevant references. MAIN RESULTS: The available evidence suggests that glutamine supplementation may decrease the incidence and/or severity of chemotherapy-associated mucositis, irinotecan-associated diarrhea, paclitaxel-induced neuropathy, hepatic veno-occlusive disease in the setting of high dose chemotherapy and stem cell transplantation, and the cardiotoxicity that accompanies anthracycline use. Oral glutamine supplementation may enhance the therapeutic index by protecting normal tissues from, and sensitizing tumor cells to chemotherapy and radiation-related injury. CONCLUSIONS: The role of glutamine in the prevention of chemotherapy and radiation-induced toxicity is evolving. Glutamine supplementation is inexpensive and it may reduce the incidence of gastrointestinal, neurologic, and possibly cardiac complications of cancer therapy. Further studies, particularly placebo-controlled phase III trials, are needed to define its role in chemotherapy-induced toxicity.  相似文献   
54.
55.
Somatostatinomas are rare neuroendocrine tumors; they are essentially located in the pancreas and in the duodenum. The association with a neurofibromatosis type I is especially observed when the tumor is located in the ampulla of Vater. These tumors are not associated with a "somatostatin syndrome", but often present with gastrointestinal bleeding, abdominal pain and obstructive jaundice. The diagnosis is confirmed by immunohistochemical studies. The aim of this study is to report 2 cases of metastazing duodenal periampullary somatostatinomas associated with von Recklinghausen's disease and to discuss the prognosis of these tumors. Future genetic research are necessary as point out the familial feature of this association in one of our cases.  相似文献   
56.
Objectives:The quality of life (QoL) of 44 men with HRPC and 37 partners (primary caregivers, most residing with the patient) was assessed in a multicenter Phase II trial of docetaxel, estramustine and low dose hydrocortisone (CALGB 9780). A secondary objective was to test the feasibility of assessing partners QoL in a cooperative group setting. Patients and methods:Patients and partners were separately interviewed by telephone at baseline, two, four and six months by a single trained research interviewer. Patients QoL was measured by the FACT-P, Mental Health Inventory-17 (MHI-17), Brief Pain Inventory (BPI), a two-day log of pain medications, and the OARS for co-morbid conditions. Partners QoL was measured by the MHI-17, Caregiver Burden Interview, and co-morbid conditions. Results:The QoL study refusal rates were low for patients (4%) and partners (3%). Although patients tended to experience greater treatment side effects in the first two months (FACT Physical Well-Being item, P = 0.057), their cancer-specific emotions (e.g., worrying about worsening health) significantly improved at two and four months (FACT-Emotional Well-Being, P = 0.003, P = 0.03, respectively), as did their prostate cancer-specific physical problems (e.g., urination, pain), at two and four months (FACT-P, P = 0.001, P = 0.005, respectively). Partners anxiety significantly decreased over time (MHI,P < 0.05). Patients quality of life at two months was significantly related to their clinical response (FACT-P total and prostate cancer-specific problems, P < 0.05), and their clinical response was significantly related to a decrease in their partners anxiety at two months (MHI, P < 0.05). Conclusions:Despite feeling worse from side effects, patients prostate cancer-specific problems and emotional state significantly improved in the first four months of treatment. With treatment significantly affecting both patients and partners lives, and the successful assessment of partners QoL, QoL of both patients and partners could be used as important endpoints in selected clinical trials.  相似文献   
57.
高效液相色谱法测定寒痹停片中士的宁含量   总被引:6,自引:0,他引:6  
目的:建立用HPLC测定寒痹停片中士的含量的方法。方法:氰基柱;流动相-甲醇-水-三乙胺-乙酸(9800:155:15:30);紫外检测波长254nm。结果:在4~20ug/ml范围内,标准曲线回归方程为:Y=-2803+8967x(r=0.9997),RSD=1.65%?加样回收率的平均值为99.82%。结论:实验表明,这是一个适用于生产控制和产品质量检验的简单、快速、准确的方法。  相似文献   
58.
The cytokines that regulate angiogenesis in normal and malignant prostate tissue are not well studied. Using an RT-PCR-based screen, we observed that cultured, low-passage normal human prostate epithelial cells (PrECs) express a variety of cytokines which have been shown to have angiogenic and/or endothelial cell-activating properties in various systems. These include vascular endothelial growth factor (VEGF), basic fibroblastic growth factor (bFGF), transforming growth factor-alpha (TGF-alpha), transforming growth factor-beta (TGF-beta), interleukin-8 (IL-8), tumor necrosis factor-alpha (TNF-alpha), granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF). Expression of VEGF, bFGF, GM-CSF, G-CSF, TGF-alpha and TNF-alpha in these cells was confirmed by immunohistochemistry. Culture medium conditioned by normal human PrECs for periods of up to 96 hr were found to contain VEGF, GM-CSF, G-CSF, IL-8, TGF-beta1 and TGF-beta2 but not TNF-alpha or bFGF, as determined by ELISA. Of these, VEGF was by far the most prominently expressed angiogenic cytokine (approx. 2,500 pg/ml conditioned medium at 96 hr vs. 30 to 100 pg/ml conditioned medium for the other cytokines). PrEC-conditioned medium induced an approximately 2-fold stimulation of [3H]-thymidine incorporation in cultured human umbilical cord endothelial cells (HUVECs) deprived of the endothelial growth factors VEGF and bFGF; this stimulation was abolished by neutralizing antibodies directed against VEGF but not bFGF, IL-8, GM-CSF or TNF-alpha. VEGF expression by PrECs was not markedly altered by administration or deprivation of other angiogenic cytokines for which these cells have receptors, suggesting that there is not a hierarchy of cytokines controlling its expression; however, retinoic acid, a component of PrEC growth medium, was found to modestly suppress VEGF at physiological concentrations (0.1 ng/ml). These data suggest that normal PrECs express a variety of angiogenic cytokines, most prominently VEGF, to recruit a supporting vasculature, even in culture. Our data also suggest that the ability of malignant PrECs to stimulate angiogenesis may be intrinsic and does not need to be acquired during oncogenesis.  相似文献   
59.
A third case of chondrodysplasia punctata after exposure to warfarin alone in early pregnancy is described. The clinical course of the child during the first 18 months is outlined. The use of warfarin in early pregnancy must be avoided because of its established teratogenic effects in causing this syndrome, in addition to an overall increase in perinatal mortality.  相似文献   
60.
Meyerovitz  MF; Reagan  K; Friedman  PL 《Radiology》1989,171(3):866-868
Posteroanterior (PA) and caudally angulated PA views were obtained in 20 patients undergoing routine coronary arteriography. Although the left main coronary artery (LMCA) was seen well on both views in all patients, the PA-caudal view improved depiction of the LMCA bifurcation in 15 (75%). In addition, the PA-caudal view markedly improved depiction of the circumflex artery, affording optimal depiction of this artery and its branches in 78%-89% of patients. Neither the PA nor the PA-caudal view allowed adequate depiction of the left anterior descending artery. Thus, the PA-caudal view should supplant the PA view in routine coronary arteriography.  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