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   9205篇
  免费   709篇
  国内免费   121篇
耳鼻咽喉   93篇
儿科学   114篇
妇产科学   316篇
基础医学   621篇
口腔科学   264篇
临床医学   1144篇
内科学   1815篇
皮肤病学   133篇
神经病学   207篇
特种医学   314篇
外国民族医学   1篇
外科学   1966篇
综合类   765篇
预防医学   1378篇
眼科学   169篇
药学   515篇
中国医学   75篇
肿瘤学   145篇
  2024年   10篇
  2023年   167篇
  2022年   260篇
  2021年   495篇
  2020年   508篇
  2019年   472篇
  2018年   469篇
  2017年   381篇
  2016年   362篇
  2015年   359篇
  2014年   802篇
  2013年   753篇
  2012年   479篇
  2011年   570篇
  2010年   464篇
  2009年   427篇
  2008年   404篇
  2007年   372篇
  2006年   323篇
  2005年   265篇
  2004年   282篇
  2003年   218篇
  2002年   169篇
  2001年   124篇
  2000年   119篇
  1999年   97篇
  1998年   76篇
  1997年   76篇
  1996年   69篇
  1995年   60篇
  1994年   58篇
  1993年   44篇
  1992年   37篇
  1991年   27篇
  1990年   26篇
  1989年   29篇
  1988年   23篇
  1987年   24篇
  1986年   14篇
  1985年   17篇
  1984年   12篇
  1983年   15篇
  1982年   13篇
  1981年   11篇
  1980年   10篇
  1979年   14篇
  1978年   13篇
  1977年   4篇
  1976年   3篇
  1973年   3篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
IntroductionStroke is the leading cause of non-traumatic disability in adults, with balance and gait disturbances representing the main limitations of body functions. Dance therapy (DT) has shown positive effects in older adults and in patients with neurological pathologies. This systematic review aims to examine the feasibility, acceptability and effects of DT in stroke rehabilitation, specifically on functional gains of gait and balance.MethodsA systematic search was carried out for articles published in the MEDLINE, PEDro, Web of Science, Scopus and CINHAL in February 2021 and updated in April 2021. Results: Eight studies were included (2 clinical cases, 5 case series and 1 randomized controlled trial), 7 of them in patients with chronic stroke and only 1 in subacute stroke phase. The most widely used dance modality was tango and ballet, with sessions ranging from 30 to 110 min. DT seems to show positive effects on post-stroke body functions and activities such as gait and balance. Reported dropout rates are inconsistent, no adverse effects were reported, and participant satisfaction was high.ConclusionGiven the heterogeneity and uneven quality of the included studies, strong conclusions cannot be put forward on the effectiveness of DT in post-stroke body function and activities. Nevertheless, DT seems to be safe and acceptable therapy for patients, and no adverse effects have been reported. More studies with a high level of evidence and feasibility are needed to determine the patient profile, the characteristics of the intervention, the participation rate and the role of the rehabilitation professional most likely to generate optimal benefit.  相似文献   
102.
103.
We examined a major organ function during 3 h biventricular assisted circulation after acute myocardial infarction model in the pig. In left ventricular circulation, the outflow cannula was placed in the ascending aorta and an inflow cannula through the mitral valve in the left ventricle. A pump (pulsatile group, Zeon Medical, Inc., Tokyo, Japan and nonpulsatile group, Nikkiso HPM-15, Nikkiso, Inc., Tokyo, Japan) was connected to each cannula. In right ventricular circulation, the outflow cannula was placed in the pulmonary artery and an inflow cannula in the right ventricle. The right ventricular circulation was supported by a nonpulsatile pump (Nikkiso HPM-15). The items measured were the regional blood flows of the cortex and medulla in the kidney, white matter and gray mater in brain, and liver; renal arterial flow; carotid arterial flow; portal vein flow; common hepatic arterial flow; arterial ketone body ratio (AKBR); and lactate/pyrubic acid (L/P). In the pulsatile group, the renal cortical blood flow increased, and the medulla blood flow decreased. On the other hand, in the nonpulsatile group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved rather than in the nonpulsatile assisted group. In addition the liver regional blood flow, AKBR, and L/P showed significant differences between the pulsatile and nonpulsatile groups. On the other hand, the white matter and gray matter regional blood flows and carotid arterial flow did not show significant differences between the groups. The results of our study indicated that pulsatile circulation produced superior circulation in the kidney and liver, and microcirculation on the cell level was superior as well in early treatment of acute heart failure.  相似文献   
104.
An ultracompact, completely implantable permanent use electromechanical ventricular assist device (VAD) and total artificial heart (TAH) intended for 50-60 kg size patients have been developed. The TAH and VAD share a miniature electromechanical actuator that comprises a DC brushless motor and a planetary roller screw. The rotational force of the motor is converted into the rectilinear force of the roller screw to actuate the blood pump. The TAH is a one piece design with left and right pusher plate type blood pumps sandwiching an electromechanical actuator. The VAD is one half of the TAH with the same actuator but a different pump housing and a backplate. The blood contacting surfaces, including those of the flexing diaphragm and pump housing, of both the VAD and TAH were made of biocompatible polyurethane. The diameter, thickness, volume, and weight of the VAD are 90 mm, 56 mm, 285 cc, and 380 g, respectively, while those of the TAH are 90 mm, 73 mm, 400 cc, and 440 g, respectively. The design stroke volume of both the VAD and TAH is 60 cc with the stroke length being 12 mm. The stroke length and motor speed are controlled solely based on the commutation signals of the motor. An in vitro study revealed that a maximum pump flow of 7.5 L/min can be obtained with a pump rate of 140 bpm against a mean afterload of 100 mm Hg. The power requirement ranged from 4 to 6 W to deliver a 4-5 L/min flow against a 100 mm Hg afterload with the electrical-to-hydraulic efficiency being 19-20%. Our VAD and TAH are the smallest of the currently available devices and suitable for bridge to transplant application as well as for permanent circulatory support of 50-60 kg size patients.  相似文献   
105.
In a follow-up study 27 patients were evaluated after anterior cruciate ligament (ACL-)reconstruction combined with high tibial osteotomy because of chronic rupture of the ACL, cartilaginous lesions of the medial compartment and varus malalignment. They were divided into two groups. In 14 patients (non-LAD group) ACL reconstruction was performed using the central third of the autologous patellar tendon modified according to Eriksson-Trillat. Thirteen patients (LAD group) underwent repair with the same technique, but a Kennedy ligament augmentation device (LAD) in hot dog technique and fixed over the top was added. The postoperative treatment was the same in both groups. All patients were examined according to IKDC criteria. KT-1000 arthrometer testing at maximum manual traction was performed. Although the mean follow-up interval was more than double in the non-LAD group (non-LAD: 127 months vs LAD: 58 months), the subjective and clinical results, IKDC evaluation and KT-1000 arthrometer testing results were similar, showing no statistically significant difference. Further, no complications due to the use of LAD occurred. In this study no evident functional or clinical advantage from the augmentation performed could be shown.Investigation performed at the Department of Orthopaedic and Trauma Surgery, University Hospital Basle, Switzerland. No benefits in any form have been received or will be received from a commercial party related directly or indirectly to the subject of this article. Funds were received in total or partial support of the research or clinical study presented in this article. The funding sources were SUVA Assurance, Lucerne, and the science fund of the University Hospital Basle  相似文献   
106.
The abdominal left ventricular assist device (ALVAD) is an order of magnitude more effective than conventional intra-aortic balloon pumping (IABP) in unloading and providing circulatory support to the failing left ventricle. This is a report of a unique case which demonstrates that in the absence of pulmonary vascular obstruction or constriction, the ALVAD can substitute for both left and right heart function. A 21-year-old patient with a congenital bicuspid aortic valve developed acute valvular endocarditis which rapidly progressed to congestive heart failure. An operation was undertaken, the mitral and aortic valves were excised and replaced by porcine heterografts, and a fistula from the right sinus of Valsalva to the right ventricle was closed. When coronary circulation was restored, irreversible ischemic contracture of the left ventricle, or "stone heart" syndrome, developed and emergency ALVAD or partial artificial heart implantation was effected. This device functioned as a total artificial heart for nearly six days, while a donor heart was sought. The patient then underwent removal of the ALVAD and cardiac and renal allografting. The transplanted heart functioned well, but the patient expired fifteen days later from gram-negative sepsis.  相似文献   
107.
Summary To evaluate whether knowledge of plasma levels of anti-epileptic drugs has an effect on therapeutic outcome, 127 epileptic outpatients were randomly assigned to two groups (A and B). Plasma levels of group A were reported to the treating physician who attempted to keep the plasma levels within the therapeutic range. The treating physician was not informed of the results of plasma lavel determinations of group B. Data from 105 patients were available for assessment at the end of the study year. Therapeutic results of groups A and B were not significantly different. The reduction in seizure frequency was associated with an increase in plasma concentrations of the anti-epileptic drugs. Thus, under the conditions of the study, knowledge of plasma levels of anti-epileptic drugs did not further improve therapeutic results.
Zusammenfassung Um festzustellen, ob die Kenntnis des Plasmaspiegels der Antiepileptika das Therapieergebnis verbessern kann, wurden 127 ambulant behandelte Patienten mit Epilepsie in randomisierter Reihenfolge in zwei Gruppen eingeteilt (A und B). Die Plasmaspiegel der Antiepileptika in Gruppe A wurden dem behandelnden Arzt mitgeteilt, der versuchen sollte, die Plasmaspiegel in den Therapeutischen Bereich zu bringen. Die Ergebnisse der Plasmaspiegelbestimmung in Gruppe B (Kontrollgruppe) wurden dem behandelnden Arzt nicht mitgeteilt. Am Ende des Untersuchungsjahres konnten die Daten von 105 Patienten ausgewertet werden. Das Behandlungsergebnis von Gruppe A und von Gruppe B war am Ende des Beobachtungsjahres nicht signifikant verschieden. Die Abnahme der Anfallshäufigkeit ging mit einem Anstieg der Plasmakonzentration der Antiepileptika einher. Somit konnte unter den Bedingungen dieser Studie das Therapieergebnis durch die Kenntnis der Plasmaspiegel der Antiepileptika nicht weiter verbessert werden.
  相似文献   
108.
The response of salbutamol (Ventolin, Glaxo), topically administered from a metered dose inhaler (MDI) through a new baby-spacer-device (Babyhaler, Glaxo) was studied in 14 infants (8 wheezy infants, 3 infants with cystic fibrosis and 3 infants after respiratory distress syndrome), age 2.9–18.8 months. Changes in thoracic gas volume (TGV) as an estimate of pulmonary hyperinflation and changes in airway conductance (Gaw) as an estimate of bronchial obstruction were assessed by whole-body plethysmography. After baseline measurements, 1 puff of 100 g salbutamol was given repeatedly at 5 min intervals until 600 g have been inhaled and TGV and Gaw were measured after each inhalation at 5, 10, 15, 20, 25 and 30 min. Significant improvement in lung function was achieved in 57.1% of infants after 400 g and in 92.9% of infants after 600 g salbutamol. The study shows usefulness of bronchodilator treatment in infants with bronchopulmonary disease by a system with a MDI and baby-spacer-device. However a special dose-time relationship must be respected.Presented in part at the 1990 World Conference on Lung Health, May 20–24, 1990 — Boston, Massachusetts, U.S.A.  相似文献   
109.
Although rotary blood pumps do not contain an inherent mechanism for adaptation to physiological flow necessities, hitherto only a few efforts have been made to obtain robust monitoring and control methods. This paper discusses the necessity of noninvasive monitoring of such pumps and the crucial points of sensor selection and development. A strategy of monitoring atrial pressure out of the data obtained by the collapse of the atrial wall around the inflow cannula and initial results on animal tests and computer simulation of this method are discussed. This approach might lead to reliable and demand-responsive controllers, if some basic criteria are fulfilled.  相似文献   
110.
采用测量溯源理论和方法建立中药质量保证体系   总被引:2,自引:0,他引:2  
中药及相关产业具有巨大的开发潜力和发展前景,已成为全世界新药开发和医药产业发展的方向之一。我国中药质量标准体系的建立是中药现代化首先解决的关键问题之一,为了保证各实验室检测数据准确、可靠、可比、互认,需要以国际上测量溯源理论和方法为依据,加强政府和中药管理部门对中药及相关产业的标准、法律法规等的建设,使中药质量保证体系与国际接轨,保护我国的经济利益、人民健康和广大消费者的利益不受损害。  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