首页 | 官方网站   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   28831篇
  免费   2375篇
  国内免费   31篇
医药卫生   31237篇
  2021年   399篇
  2020年   235篇
  2019年   347篇
  2018年   417篇
  2017年   300篇
  2016年   361篇
  2015年   412篇
  2014年   616篇
  2013年   930篇
  2012年   1176篇
  2011年   1340篇
  2010年   765篇
  2009年   567篇
  2008年   1165篇
  2007年   1282篇
  2006年   1279篇
  2005年   1199篇
  2004年   1182篇
  2003年   1028篇
  2002年   971篇
  2001年   965篇
  2000年   980篇
  1999年   777篇
  1998年   314篇
  1997年   297篇
  1996年   260篇
  1995年   278篇
  1994年   242篇
  1993年   227篇
  1992年   692篇
  1991年   705篇
  1990年   663篇
  1989年   636篇
  1988年   612篇
  1987年   575篇
  1986年   593篇
  1985年   557篇
  1984年   436篇
  1983年   427篇
  1982年   279篇
  1981年   266篇
  1980年   241篇
  1979年   430篇
  1978年   317篇
  1977年   277篇
  1976年   250篇
  1975年   238篇
  1974年   297篇
  1973年   261篇
  1972年   233篇
排序方式: 共有10000条查询结果,搜索用时 826 毫秒
81.
The beStent is a new stainless steel, balloon-expandable mesh stent which has a unique serpentine design. Rotation of the unique low stress junctions upon expansion leads to orthogonal locking of the wires, maximizing radial strength and assuring zero shortening. The stent has delineating gold markers which assure precise positioning. We aim to present the initial acute results in a pilot registry for stent evaluation. Two hundred eighty-four stents were used in a total of 217 patients (age 57.9 ± 3.10 years; 178 males; 39 females) in seven centers, for variable indications. Stents of 15-, 25-, and 35-mm length were used. The arteries treated were the left anterior descending (n = 112, 42%), circumflex (n = 54, 20.2%), right coronary (n = 95, 35.5%), left main (n = 1, 0.4%), and vein graft (n = 5, 1.9%). Lesion types were: A in 42 patients (16.5%); B1 in 53 patients (20.7%); B2 in 81 patients (31.8%); and C in 79 patients (31%). One hundred fifty-nine patients required one stent, 40 patients required two stents, and 18 patients required three or more stents. Anticoagulation protocol included procedural heparin with aspirin with/without ticlopidine. Smooth angiographie results were obtained in all cases with no plaque herniation. Acute angiographic success was obtained in 97% of the patients, and acute clinical success in 95% of the patients. Complications within 30 days were: 3 deaths (1.4%) (2 noncardiac); 2 (0.9%) myocardial infarctions; and 2 (0.9%) stent thromboses. Therefore, the beStent is useful in treatment of complex lesions of variable length and complexity, providing excellent acute results with a low complication rate, in spite of unfavorable basic clinical and angiographie characteristics.  相似文献   
82.
83.
Treatment with the monoclonal antibody OKT3 specific for the CD3 complex associated with the T cell antigen receptor can reverse acute rejection of human renal allografts. However, efficacy of anti-CD3 antibodies for treatment of patients with acute graft-versus-host disease after marrow transplantation has not been established. The dose-limiting side effects resulting from T cell activation induced by some anti-CD3 antibodies in vivo have discouraged their use for this application. We now report a phase I-II study of GVHD treatment with the anti-CD3 antibody BC3, a monoclonal murine IgG2b that, unlike OKT3, does not activate T cells. Fourteen patients were treated with BC3 after progression of acute GVHD despite treatment with cyclosporine and corticosteroids, and three patients received BC3 as primary treatment for GVHD. BC3 was administered at a dose of 0.1 or 0.2 mg/kg/day for seven or eight days. Five patients achieved complete resolution of GVHD, eight patients had partial improvement, two patients had no change, and two patients had progression of GVHD on therapy. Responses were sustained in 8 of 13 patients. Mild chills, fever, hypertension, and chest discomfort occurred in various combinations following 6 of 17 (35%) initial infusions of BC3 and following 4 of 99 (4%) subsequent infusions. In each instance it was possible to continue BC3 therapy without adjusting the dose or treatment schedule. In each patient treated, the absolute count of peripheral blood lymphocytes decreased transiently but returned to baseline within 22 hr after the first infusion. Circulating T cells had surface CD3 molecules saturated by the infused antibody in all but one patient. Four patients survived longer than one year after treatment with antibody BC3, and 13 patients died of infection or organ failure. Administration of the nonmitogenic anti-CD3 antibody BC3 was associated with improvement in the clinical manifestations of GVHD with minimal acute toxicity. Efficacy of antibody treatment did not depend on depletion of circulating T cells. Therefore, antibody BC3 may be achieving therapeutic immunosuppression by modulating T cell function. Controlled studies in patients treated earlier in the course of GVHD should determine whether antibody BC3 can improve survival.  相似文献   
84.
85.
Why should depression screening be conducted in chronically ill populations? Depression is a disabling illness and is very common among patients who have chronic illnesses. Despite its high prevalence in this patient population, depression often goes unrecognized. Having a plan for a population-based screening program for depression can not only identify patients who are at risk of depression, but can also help to foster early treatment and enhanced care for these patients. This article provides an overview of commonly-used depression screening tools and presents an example of how this might be carried out in a healthcare organization.  相似文献   
86.
Lymphocytes in formalin-fixed skin biopsies from patients with cutaneous acute graft-versus-host disease (aGVHD) were studied with HECA-452 (an antibody recognizing lymphocytes with skin-homing properties) and a panel of antibodies recognizing pan-B (L26 [CD20]), pan-T (L60 [CD43] and A6 [CD45RA]), and T-helper subset (OPD4) antigens in paraffin sections. Biopsies from patients with erythema multiforme (EM) were similarly studied for comparison. In both conditions, T lymphocytes stained by OPD4 were predominantly confined to the dermis, whereas those stained by HECA-452 were concentrated in the epidermis; however, there was considerable variation between cases, and overlap between findings in the dermis and epidermis. Lymphocytes similarly studied in paraffin sections of liver, salivary gland, and gut affected by aGVHD were essentially unreactive with HECA-452, although they were largely stained by pan-T markers and showed some comparable reactivity with OPD4. The findings suggest that aGVHD of the skin is mediated by a different set of lymphocytes than in gut organs, and may have a similar immunologic mechanism to EM.  相似文献   
87.
Plasma growth hormone concentrations were measured at hourly intervals between 10 p.m. and 8 a.m. the next morning in 15 drug-free chronic schizophrenic male inpatients and 14 healthy males. Growth hormone secretion was significantly lower in the patients as compared with the controls. Growth hormone release peaked around 1 a.m. in the controls, but a growth hormone peak was absent in the patient group. Increased dopamine activity, increased serotonin activity, or both could explain the absence of a nocturnal growth hormone surge in the schizophrenic patients.  相似文献   
88.
There has been considerable progress in the treatment of chronic hepatitis C since the first report that interferon (IFN) monotherapy was effective in 1989. Early results were meager, with sustained loss of hepatitis C virus from blood in fewer than 10% of cases. The combination of IFN with the oral nucleoside analogue ribavirin was a major breakthrough in clinical hepatology; it led to dramatic increases in treatment responses, with 30% to 40% of patients clearing virus. Pegylated IFNs that have prolonged activity and can be dosed once a week have now replaced standard IFNs. The combination of pegylated IFN with ribavirin is the new standard of care; it causes sustained loss of virus in more than half of treated patients. Treatment responses continue to be highly dependent on viral genotype. Patients with genotype 1, the most common type in the United States, have a sustained clearance rate of 42% to 46%, whereas those with genotype 2 or 3 have a response rate approaching 80%.  相似文献   
89.
90.
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-23

京公网安备 11010802026262号