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   62597篇
  免费   4005篇
  国内免费   1254篇
耳鼻咽喉   241篇
儿科学   2138篇
妇产科学   755篇
基础医学   3829篇
口腔科学   517篇
临床医学   8451篇
内科学   19730篇
皮肤病学   187篇
神经病学   895篇
特种医学   1011篇
外国民族医学   1篇
外科学   7420篇
综合类   9751篇
现状与发展   3篇
预防医学   3439篇
眼科学   85篇
药学   5795篇
  52篇
中国医学   2829篇
肿瘤学   727篇
  2024年   128篇
  2023年   1013篇
  2022年   1906篇
  2021年   2578篇
  2020年   2465篇
  2019年   2178篇
  2018年   2113篇
  2017年   1937篇
  2016年   2007篇
  2015年   2129篇
  2014年   4454篇
  2013年   4662篇
  2012年   3550篇
  2011年   4116篇
  2010年   3227篇
  2009年   3228篇
  2008年   3122篇
  2007年   3137篇
  2006年   2771篇
  2005年   2596篇
  2004年   2008篇
  2003年   1690篇
  2002年   1357篇
  2001年   1288篇
  2000年   945篇
  1999年   864篇
  1998年   696篇
  1997年   648篇
  1996年   593篇
  1995年   530篇
  1994年   540篇
  1993年   387篇
  1992年   348篇
  1991年   332篇
  1990年   294篇
  1989年   293篇
  1988年   273篇
  1987年   209篇
  1986年   182篇
  1985年   176篇
  1984年   148篇
  1983年   85篇
  1982年   110篇
  1981年   91篇
  1980年   77篇
  1979年   80篇
  1978年   62篇
  1977年   60篇
  1976年   52篇
  1973年   29篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
141.
Abstract A blood purification system, molecular adsorbents re-circulating system (MARS), is based on the removal of both protein-bound and water-soluble substances and toxins in the liver. We treated a total of 88 patients within 2 years. Of these patients, 45 had acute liver failure (ALF), 31 had acute decompensation of chronic liver disease, eight had graft failure and four had miscellaneous conditions. Of the patients with ALF, 80% survived; in 23 patients their own liver recovered and 13 patients underwent successful transplantation. Only 23% of patients with acute-on-chronic liver failure survived. Most of them were not considered for transplantation due to their having liver failure from alcoholism and from not abstaining from drinking. MARS is a promising therapy for ALF, allowing the patient's own liver to recover or allowing enough time to find a liver graft. Best results were achieved in patients who had been intoxicated with a lethal dose of toxin. On the other hand, we did not observe much benefit in patients with severe acute-on-chronic liver failure (AcoChr) who did not undergo liver transplantation.  相似文献   
142.
上尿路梗阻性急性肾功能不全内、外引流的选择   总被引:1,自引:1,他引:0  
目的探讨内、外引流在上尿路梗阻急性肾功能不全时的选择和效果。方法25例各种原因引起的上尿路梗阻(15例肿瘤性梗阻,10例非肿瘤性梗阻)合并急性肾功能不全,分别或先后对12例行输尿管内置双J管(doub le J,D J)内引流15次,对19例行经皮肾穿刺造瘘(percutaneous nephrectomy,PCN)外引流23次。结果引流成功23例,PCN外引流成功率86.9%(20/23),双J管内引流成功率60.0%(9/15),PCN术后继发出血1例。结论对于盆腹腔进展期或广泛转移肿瘤导致的梗阻,PCN解除梗阻优于输尿管支架内引流;非肿瘤性梗阻宜先尝试D J内引流。  相似文献   
143.
Longitudinal studies were conducted over a five-year period for HLA antibodies on 493 sera tested from 54 kidney transplant patients. HLA single antigen beads were employed to establish donor specificity of the antibodies. Only 3 of 22 patients without antibodies rejected a graft in contrast to 17 out of 32 patients with posttransplant antibodies (p = 0.003). Using a serum creatinine value of 4.0 mg/dL as the cut-off for a failed graft, 4 of 22 patients without antibodies failed compared to 21 of 32 with antibodies (p = 0.0006). Among patients with donor-specific antibodies (DSA) 13 of 15 failed (p = 0.000004). Even among patients with non-donor specific antibodies (NDSA), 8 of 17 failed (p = 0.05). Among patients who could be identified as making de novo antibodies (since they developed antibodies while not having antibodies for more than six months after transplantation), 6 of 11 failed (p = 0.03). Sequential testing for HLA antibodies shows that antibodies appear prior to a rise in serum creatinine and subsequent graft failure. The very strong association between the production of HLA antibodies after transplantation and graft failure indicates the importance of monitoring for posttransplant HLA antibodies.  相似文献   
144.
Diabetic nephropathy and anaemia   总被引:2,自引:0,他引:2  
  相似文献   
145.
146.
呼吸电刺激训练对肺功能康复的作用   总被引:1,自引:1,他引:0  
通过电流和声、光信号刺激,对20例慢性阻塞性肺疾患(COPD)患者进行呼吸电刺激训练(RET),结果在RET时呼吸频率和平均吸气流速明显下降,潮气量和吸气间期明显增加,跨膈压增大,氧耗量和能量代谢无明显变化;于RET15天后PaCO2明显下降,PaO2和运动能力明显增高,肺勇气功能明显改善。表明RET15天后PaCO2明显下降,PaO2和运动能力明显增高,肺通气功能明显改善。表明RET能使COPD  相似文献   
147.
Chronic renal failure and its treatment in tuberous sclerosis   总被引:2,自引:0,他引:2  
BACKGROUND.: Chronic renal failure is rare in tuberous sclerosis, but itsprecise frequency is not known and treatment modalities havenot been evaluated. METHODS.: A questionnaire was addressed to the 260 French dialysis centresand the characteristics of 65 patients with tuberous sclerosisand chronic renal failure were analysed. RESULTS.: In France the approximate prevalence of tuberous sclerosis withend-stage renal failure is 0.7 cases per million and that ofend-stage renal failure in tuberous sclerosis 1 per 100. Tuberoussclerosis with chronic renal failure was more frequent in females(63.1%) and was diagnosed at a mean age of 29 years. Renal impairmentwas the first manifestation of tuberous sclerosis in about halfthe cases. Renal tumours were frequent, with angiomyolipomasin 15 cases (23.1%), cysts in 12 cases (18.5%), and both in35 cases (53.8%). Malignancies were associated in nine cases(13.8%). Nephrectomy was done before dialysis in 21 cases (32.3%),and after the start of dialysis in six cases (9.2%). All butone of the 48 patients with end-stage renal failure were treatedby dialysis; 20 were transplanted, with good results. CONCLUSIONS.: Tuberous sclerosis with end-stage renal failure is rare. Thesepatients require dialysis and renal transplantation, but werecommend binephrectomy after starting dialysis and before transplantation,given the risk of cancer and bleeding related to angiomyolipomas.  相似文献   
148.
Summary: Despite numerous deficiencies in some antihypertensive drug treatment trials, and some questionable selections of studies for inclusion in several meta-analyses, undoubtedly such trials have shown treatment benefits from reducing hypertension. Complications that can be corrected or prevented include malignant hypertension, hypertensive heart failure, stroke and coronary artery morbidity. the all-cause mortality has been lowered in several trials. the benefits have been seen in subjects aged over 60 years, in women and men, and in patients with isolated systolic hypertension. the benefits have been achieved using a wide range of drugs, not only with beta-blockers or diuretics. Non-pharmacological means of lowering blood pressure have not been evaluated in relation to morbidity.  相似文献   
149.
Two hundred and ten patients with clinical evidence of heartfailure, developing after an acute myocardial infarction, wererandomized to treatment with the ß1 antagonist metoprolol50–100mg b.i.d. (n=106) or the ß1 partial agonistxamoterol 100–200 mg bid. (n=104). Left ventricular systolicand diastolic function were assessed with echocardiography andtransmitral Doppler cardiography before and after 3 and 12 monthsof double-blind treatment. E-point septal separation and percent left ventricular fractional shortening were used as indicesof systolic function. The ratio between peak early and latemitral diastolic flow (E/A ratio) and isovolumic relaxationtime were used as indices of diastolic function. In the xamoterol group, there was a deterioration in E-pointseptal separation (P<0·05). A difference between thetreatment groups was present both at 3 months (E-point septalseparation 11·4 vs 13·0 mm, P<0·0l,fractional short ening 271 vs 252%, P<005) and 12 months(E-point septal separation Ill vs 13·2 mm, P<0·05fractional shortening 26·9 vs 25·0%, P<0·05).E/A ratio increased in the metoprolol group (P<0·05)but not in the xamoterol group. At 3 months there was a significantdifference (0·85 vs 0·67, P<0·005 betweenthe groups but not at 12 months. In comparison with the ß1-receptor antagonist metoprolol,the ß1 partial agonist xamoterol impaired left ventricularsystolic function in patients with clinical evidence of heartfailure after an acute myocardial infarction.  相似文献   
150.
Four infants with severe intrauterine growth retardation (IUGR) weighing less than 1000 g at birth developed heart failure and died in our unit, where heart failure of IUGR infants is the main reason of death in extremely low birth-weight infants. The causes of their heart failure are one of the main themes in current neonatal medicine. The subjects of this study were four small for gestational age infants; all died due to heart failure 5 to 10 days after birth. Microscopic specimens of hearts from autopsies were evaluated with respect to the following characteristics: thickness of myocardial fibers, maturation of nuclei, presence of dysgenesis or necrosis in myocardium, and amount of glycogen in the heart. Neither dysgenesis nor infarction of the heart was found but hypoplasia in myocardial fibers and decreased glycogen levels were observed. Maturation delay in myocytes' nuclei did not appear to be severe. We conclude that these infants' hearts failed to adapt to postnatal hemodynamic changes because of inadequate myocardial function and inadequate glycogen reserves.  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