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   5353篇
  免费   470篇
  国内免费   153篇
耳鼻咽喉   46篇
儿科学   252篇
妇产科学   59篇
基础医学   231篇
口腔科学   76篇
临床医学   949篇
内科学   1331篇
皮肤病学   19篇
神经病学   272篇
特种医学   125篇
外科学   614篇
综合类   829篇
预防医学   370篇
眼科学   146篇
药学   391篇
  21篇
中国医学   124篇
肿瘤学   121篇
  2024年   14篇
  2023年   113篇
  2022年   192篇
  2021年   340篇
  2020年   301篇
  2019年   223篇
  2018年   209篇
  2017年   245篇
  2016年   252篇
  2015年   233篇
  2014年   395篇
  2013年   415篇
  2012年   305篇
  2011年   316篇
  2010年   254篇
  2009年   258篇
  2008年   219篇
  2007年   238篇
  2006年   181篇
  2005年   133篇
  2004年   151篇
  2003年   126篇
  2002年   102篇
  2001年   90篇
  2000年   67篇
  1999年   75篇
  1998年   52篇
  1997年   46篇
  1996年   43篇
  1995年   50篇
  1994年   27篇
  1993年   28篇
  1992年   37篇
  1991年   33篇
  1990年   20篇
  1989年   23篇
  1988年   17篇
  1987年   24篇
  1986年   18篇
  1985年   22篇
  1984年   18篇
  1983年   11篇
  1982年   15篇
  1981年   9篇
  1980年   10篇
  1979年   9篇
  1978年   5篇
  1977年   4篇
  1975年   4篇
  1971年   1篇
排序方式: 共有5976条查询结果,搜索用时 31 毫秒
51.
This prospective study was completed to determine the influence of epidural anaesthesia on the fetoplacental circulation of normal subjects. Thirty-seven normal pregnant patients at term, undergoing elective Caesarean section, had Doppler measurements of the fetal umbilical artery blood flow velocity before and after epidural anaesthesia using lidocaine 2% without epinephrine. There were no differences in systolic/diastolic, resistance or pulsality indices following epidural anaesthesia. These results suggest that this technique has no adverse effect on fetoplacental circulation in normal non-labouring subjects. Cette étude prospective a pour but de déterminer l’influence de l’anesthésie épidurale sur la circulation foeto-placentaire dans le contexte d’une grossesse normale. Des indices de vélocité du flot de l’artère ombilicale foetale ont été mesurés par Doppler chez trentesept patientes gravides à terme, sans complications, programmées pour une césarienne élective, avant et après une anesthèsie épidurale utilisant la lidocaine 2% sans épinéphrine. Les indices de rapport systole/diastole, de résistance et de pulsatilité sont demeurés inchangés après l’induction de l’anesthésie épidurale. Ces constatations suggèrent que l’anesthésie épidurale n’a pas d’influence sur la circulation foetoplacentaire chez des patientes enceintes normales à terme qui ne sont pas en travail.  相似文献   
52.
We compared peritoneal dialysis effluents from 18 CAPD patientswho had not suffered from peritonitis during the last 6 months(group 1) with the effluents from five patients with acute peritonitis(group 2), measuring activation markers of coagulation and fibrinolysis.These markers included prothrombin fragment F1+2 (F1+2), thrombin-antithrombinIII complex (TAT), fibrin monomer (FM), and fibrin degradationproducts (FbDP). In the dialysate of group 1 we found remarkablyhigh levels of F1+2, TAT and FM concomitant with a high concentrationof FbDP, indicating a high rate of intraperitoneal fibrin turnover.The balance between peritoneal generation and degradation offibrin was disturbed in untreated patients of group 2, who hadsignificantly higher levels of coagulation markers and a higherratio between FM and FbDP. Seven days after treatment with intraperitonealadministration of antibiotics and heparin, F1+2, TAT, FM andFbDP decreased significantly. To evaluate the role of mesothelial cells (MC) in the high peritonealfibrin turnover we investigated the expression of tissue-typeplasminogen activator (t-PA), urokinase-type plasminogen activator(u-PA), plasminogen activator inhibitor type-1 (PAI-1), andtissue factor in cultured human peritoneal MC under basal conditionsand after exposure to tumour necrosis factor (TNF) interleukin-1(IL-1), or bacterial lipopolysaccharide (LPS). The exposureof MC to TNF or to a lesser extent IL-1 or LPS reduced theirfibrinolytic activity by decreasing t-PA production and increasingPAI-1 synthesis. Furthermore the addition of TNF resulted inactivation of the coagulation cascade by the expression of tissuefactor. These in-vitro findings explain the imbalance betweenintraperitoneal coagulation and fibrinolysis during peritonitisof CAPD patients.  相似文献   
53.
目前下肢被动运动装置存在的问题和改进原则   总被引:3,自引:0,他引:3  
本文分析了目前下肢CPM装置存在的问题,指出在CPM每一运动周期,人体下肢与CPM支架之间都将产生有害的相对位移和交替牵拉应力,影响关节功能顺利康复。提出下肢CPM的正确使用方法和设计原则。  相似文献   
54.
鲍光全 《眼科学报》1999,15(2):121-123
目的:评价在白内障手术中使用高频透热撕囊仪作连续环形撕囊的效果。方法:在30例(34眼)患者进行白内障囊外摘出联合后房型人工晶体植入术中,先向前房注入透明质酸钠,然后使用高频透热撕囊仪作晶体连续环形撕囊术。结果:有3眼术中出现小的晶体前囊放射状撕裂,所有病例术后角膜无水肿,无其他术后合并症,术后一周31眼矫正视力≥0.5,占91.2%。结论:此法操作简便,易于掌握,是一个安全有效的连续环形撕囊的方法。尤其适用于过熟期白内障,儿童先天性白内障和外伤性白内障的截囊。眼科学报1999;15:121—123。  相似文献   
55.
Summary Crisnatol mesylate is a rationally designed cytotoxic arylmethylamino-propanediol with broad spectrum cytotoxic activity. A phase I study with an unconventional escalation scheme was developed using a constant drug infusion rate (mg/m2/hr) and prolonging the infusion duration from 6 to 96 hours. Sixty-five patients received crisnatol at doses from 18 mg/m2 in 6 hrs to 3400 mg/m2 in 72 hours. The dose-limiting toxicity in two of five patients at 2700 mg/m2 and two of three patients at 3400 mg/m2 was neurologic and consisted of a syndrome of confusion, agitation, and disorientation. Phlebitis mandated the use of a central line. The mean terminal phase half-life (T1/2 ) was 3.3 hours with a total body clearance (CL) of 22.8 L/hr/m2 and a volume of distribution (Vdss) of 53 L/m2. The median steady-state peak plasma concentration (Css) at 2700 mg/m2/72 hours was 2.7 g/ml and at 3400 mg/m2/72 hours was 3.8 g/ml. No responses were seen. The maximum tolerated dose (MTD) on this schedule is 2700 mg/m2/72 hours in patients with no liver disease and good performance status.  相似文献   
56.
Summary Twenty-nine patients with advanced Parkinson's disease were treated with subcutaneous lisuride infusion in addition to a basic therapy consisting of levodopa + PDI in all, and deprenyl in some patients. At the time of the report, 13 patients are still receiving lisuride infusion after 5–36 months, while 16 have dropped out after 0.5–30 months one because of psychosis, three because of insufficient efficacy, three due to death unrelated to treatment, three because of difficulties in handling the pump as outpatients, and six for other reasons. Off-periods and parkinsonian disability in off and in on were reduced significantly. These improvements remained constant throughout the observation period. Once the optimal dose regimen is established, only minor adjustments of the doses of lisuride and levodopa are required in the individual case.  相似文献   
57.
傅华 《安徽医药》2003,7(4):321-322
目的 探讨胃癌手术后硬膜外持续镇痛对患者肠功能的影响。方法 对 6 0例胃癌术后病人进行随机分组 ,PCEA(pa tientcontrolledEpiduralanalgesia)组 :采用硬膜外持续镇痛 (30例 ) ;对照组 :采用间断注射镇痛剂 (30例 ) ,观察肠蠕动、肛门排气时间及不良反应。结果 肠蠕动恢复时间PCEA组 (5 2 1± 4 3)h ,对照组 (5 1 5± 4 4 )h。肛门排气时间PCEA组 (6 5 4±7 5 )h ,对照组 (5 6 1± 9 3)h。PCEA组不良反应明显少于对照组。结论 术后镇痛不影响胃癌术后肠蠕动恢复 ,但应加强术后早期活动的指导  相似文献   
58.
[目的]探讨晚期卵巢癌腹腔转移的治疗方法。[方法]以顺铂 卡铂 依托泊甙为主的联合方案行腹腔持续热灌注化疗并腹腔射频透热治疗28例晚期卵巢上皮癌,观察其疗效及毒副反应。[结果]完全缓解(CR)5例,部分缓解(PR)16例,稳定(NC)5例,进展(PD)2例,总有效率75.0%。主要毒副反应为骨髓抑制。[结论]双铂联合依托泊甙腹腔热灌注并射频透热治疗对中晚期卵巢癌疗效较好,毒副反应少。  相似文献   
59.
Background: Ifosfamide has important activity in pretreated soft tissue sarcomas (STS), and recent data support a clinically significant dose-response relationship for this agent. Administration by continuous infusion and hematopoietic support have rendered dose intensification regimens possible by reducing both hematologic and non-hematologic toxicities. The optimal dose and schedule of ifosfamide when given at high doses remain to be defined. In a previous phase I study, we demonstrated the feasibility of a continuous infusion (c.i.) high-dose ifosfamide (HDI) regimen in the ambulatory setting for patients with advanced solid tumors. The objective of the present phase II study was to assess the antitumor activity and toxicity of such a schedule in patients with advanced pretreated STS.Patients and methods: Thirty-eight patients with advanced and/or metastatic STS, all pretreated with an anthracycline with or without standard-dose ifosfamide, were treated. Ifosfamide was given by c.i. at a dose of 3.5 g/m2/day over four consecutive days, with equidose mesna uroprotection over five days. G-CSF was added at a dose of 200 µg/m2/day subcutaneously from day 6 to day 12. Cycles were repeated every three weeks in the outpatient setting.Results: A total of 159 cycles of therapy were given (median 4 per patient, range 3–6). Treatment compliance was generally satisfactory. The major toxicity was hematologic, with six febrile neutropenic episodes requiring hospitalisation and parenteral antibiotics. Acute renal failure occurred in one patient after three cycles of therapy; central nervous system toxicity was mild. An overall response rate of 39% was observed (95% confidence interval, 26% to 55%), with one complete and 14 partial remissions. All but one of the responder patients had previously received standard-dose ifosfamide. The median response duration was nine months (range 5–21+ months), and the overall median survival ranged from 6–30+ months (median 13 months).Conclusions: High-dose ifosfamide is an active regimen in anthracycline- pretreated STS. Future clinical trials should be aimed at evaluating the impact of different administration schedules on clinical response and outcome. The potential role of HDI as front-line chemotherapy as well as in the adjuvant treatment of STS needs to be investigated in randomized trials.  相似文献   
60.
Purpose: The objective of this multicenter study was to compare the efficacy and toxicity profiles of a combination of 5-fluorouracil (5-FU) given by bolus injection together with intravenous leucovorin (LV) versus high-dose 5-FU in continuous infusion (CI) in the treatment of advanced colorectal cancer.Patients and methods: A total of 306 patients were randomized to receive either 5-FU 425 mg/m2 given by bolus injection on days 1–5 plus intravenous (i.v.) LV 20 mg/m2 every four to five weeks or 5-FU 3.5 g/m2/week in a 48-hour CI. Therapy was continued until disease progression. Second-line chemotherapy was allowed in both arms.Results: The response rates in 306 patients with measurable lesions were 19.2% (modulated arm) and 30.3% (CI arm, P < 0.05). The median progression-free survival times were 23.5 weeks (modulated arm) and 25 weeks (CI arm, P = NS). Median survival times were 42.5 weeks (modulated arm) and 48 weeks (CI arm, P = NS). There were no significant differences in grade 3–4 toxicity profiles but if we consider all grades we observed more mucositis in the modulated arm and more hand-foot syndrome in the CI arm.Conclusions: In terms of response rate, the continuous infusion regimen was more effective than the modulated regimen. There was no significant difference in survival and time to progression, and none in grade 3–4 toxicity.  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