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   1825篇
  免费   90篇
  国内免费   10篇
耳鼻咽喉   45篇
儿科学   55篇
妇产科学   38篇
基础医学   191篇
口腔科学   93篇
临床医学   185篇
内科学   346篇
皮肤病学   24篇
神经病学   116篇
特种医学   112篇
外科学   242篇
综合类   35篇
一般理论   1篇
预防医学   121篇
眼科学   33篇
药学   211篇
中国医学   9篇
肿瘤学   68篇
  2023年   13篇
  2022年   33篇
  2021年   73篇
  2020年   41篇
  2019年   51篇
  2018年   69篇
  2017年   58篇
  2016年   50篇
  2015年   64篇
  2014年   82篇
  2013年   113篇
  2012年   155篇
  2011年   129篇
  2010年   95篇
  2009年   66篇
  2008年   110篇
  2007年   125篇
  2006年   110篇
  2005年   94篇
  2004年   63篇
  2003年   66篇
  2002年   63篇
  2001年   23篇
  2000年   18篇
  1999年   15篇
  1998年   13篇
  1997年   13篇
  1996年   7篇
  1995年   5篇
  1994年   5篇
  1993年   3篇
  1992年   6篇
  1991年   12篇
  1990年   8篇
  1989年   10篇
  1988年   5篇
  1987年   7篇
  1986年   6篇
  1985年   3篇
  1984年   7篇
  1981年   5篇
  1980年   2篇
  1975年   3篇
  1973年   2篇
  1972年   4篇
  1971年   2篇
  1970年   2篇
  1969年   2篇
  1968年   2篇
  1932年   2篇
排序方式: 共有1925条查询结果,搜索用时 328 毫秒
1.
Brucellosis is a world prevalent endemic illness that is transmitted from domestic animals to humans. Brucella spp. exploits urease for survival in the harsh conditions of stomach during the gastrointestinal infection. In this study, we examined the immune response and the protection elicited by using recombinant Brucella urease (rUrease) vaccination in BALB/c mice. The urease gene was cloned in pET28a and the resulting recombinant protein was employed as subunit vaccine. Recombinant protein was administered subcutaneously and intraperitoneally. Dosage reduction was observed with subcutaneous (SC) vaccination when compared with intraperitoneal (IP) vaccination. rUrease induced mixed Th1–Th2 immune responses with high titers of specific IgG1 and IgG2a. In lymphocyte proliferation assay, splenocytes from IP and SC‐vaccinated mice displayed a strong recall proliferative response with high amounts of IL‐4, IL‐12 and IFN‐γ production. Vaccinated mice were challenged with virulent Brucella melitensis, B. abortus and B. suis. The SC vaccination route exhibited a higher degree of protection than IP vaccination (p value ≤ 0.05). Altogether, our results indicated that rUrease could be a useful antigen candidate for the development of subunit vaccines against brucellosis.  相似文献   
2.
Platelet α-granules release growth factors (GFs) that promote healing and tissue regeneration. Platelet-rich plasma (PRP) is shown to be beneficial in treating alopecia, and however, clinical response can be inconsistent. Due to several fold enrichment of platelets secreting large quantities of GFs following PRP injections, heterogeneity in amounts of GFs secreted by platelets may contribute to inconsistent clinical responses. Herein, we evaluated factors that could potentially contribute to heterogeneous secretion of GFs by platelets. We measured platelet secretion of transforming growth factor beta1 (TGFβ1), platelet-derived growth factor (PDGF-BB), epidermal growth factor (EGF), vascular endothelial growth factor (VEGF) and fibroblast growth factor (FGF2) in aliquots of de-identified PRP samples from female patients undergoing therapy in the hair disease clinic. Although secretion of GFs by platelets was comparable in PRP samples of patients with non-cicatricial and cicatricial alopecia, a Shapiro-Wilk test for normal distribution indicated significant variability across all patient samples. The amount of GF secreted by platelets was comparable when PRP prepared from two FDA-cleared devices with distinct techniques were compared. We provide evidence of platelets secreting heterogeneous amounts of GFs within each sample as high and low secretion of random factors could be simultaneously detected. These results suggest inherent heterogeneity in secretion of GFs by platelets in patient samples that are not influenced by the device used to prepare PRP. Since some GFs could have antagonistic effects on hair growth, a balance between amounts of growth promoting and inhibiting factors may be crucial in determining clinical response to PRP therapy.  相似文献   
3.
We report a case of vasoactive-agent-induced priapism successfully treated in the emergency department with 10 mg of metaraminol injected into the corpora cavernosa.  相似文献   
4.
BACKGROUND: One previous follow-up study suggested that inpatient bulimic women do quite poorly; after an interval of 2 to 5 years, only 13% were recovered. To examine the course and outcome of a sample of patients with bulimia nervosa that was severe enough to require inpatient hospitalization, the authors conducted the following study. METHOD: Women (N = 52) with DSM-III-R bulimia nervosa were sought 2 to 9 years after hospitalization. Prior to contact, a retrospective chart review was conducted to determine global functioning and admission diagnoses. At follow-up, patients participated in a 4 to 6 hour interview that assessed current and lifetime Axis I disorders (SCID-I), current Axis II disorders (PDE), eating behaviors (EAT, BSQ, EDI, PSR), global functioning (GAF), social adjustment (SAS-SR), and treatment and medical problems experienced since discharge. To assess the significance of differences between the recovered and the currently bulimic women, Yates-corrected chi-square tests and two-tailed t tests were used. RESULTS: Of the 52 women, 46 were interviewed, 1 had died, and 5 could not be located. Of the 46 interviewed women, 39% had fully recovered, 20% had partially recovered, and 41% were currently bulimic. The likelihood of recovery increased with length of time since discharge. While medical problems related to the bulimia were few, treatment with phenelzine was associated with three reports of serious hypertensive episodes, one of which led to death. Global functioning before hospitalization, lifetime DSM-III-R Axis I diagnoses, and current Axis II diagnoses were not associated with outcome. CONCLUSIONS: These findings suggest that even severely ill bulimic patients have a significant chance of achieving full recovery.  相似文献   
5.
OBJECTIVE: The purpose of this study was to investigate the incidence of the retroaortic left renal vein (RLRV) in patients with varicocele. METHODS: The left renal vein was ultrasonographically investigated for the presence of the RLRV in 140 patients with varicocele and a control group of 137 age-matched patients. The main diagnostic criteria for varicocele were the presence of a varicose vein with a diameter of 3 mm or larger at rest and with a reflux lasting more than 2 seconds during the Valsalva maneuver. The RLRV was defined as a posterior course of the left renal vein to the aorta at the level of the origin of the superior mesenteric artery. RESULTS: The RLRV was observed in 13 (9.3%) of the 140 patients with varicocele and 3 (2.2%) of the control patients. The incidence of the RLRV was found to be significantly higher in patients with varicocele compared with the control patients (P = .018, Fisher exact test). In 13 patients with the RLRV, left varicocele and bilateral varicocele were detected in 10 and 3 cases, respectively. CONCLUSIONS: In this study, the incidence of the RLRV was found to be significantly higher in patients with varicocele compared with control patients. Thus, we suggest that the presence of the RLRV may be considered one of the etiologic factors in the development of varicocele.  相似文献   
6.
Ten cardiology chest pain patients without clinical evidence of coronary artery disease and with panic disorder were enrolled in an open label trial of alprazolam. Two dropped out at week 3 because of excessive side effects. The eight study completers showed significant decreases in both Hamilton Anxiety and Hamilton Depression scales by week 2 that remained significant by week 8. On the physician's global impression of change since baseline, all completers were rated at least "much improved." Seven experienced a 50% or greater reduction in panic frequency at week 8 compared to baseline. These results suggest that alprazolam is likely to be of benefit to this patient population.  相似文献   
7.
In this paper, we review optical techniques used for micro-manipulation of small particles and cells in microfluidic devices. These techniques are based on the object's interaction with focused laser light (consequential forces of scattering and gradient). Inorganic objects including polystyrene spheres and organic objects including biological cells were manipulated and switched in and between fluidic channels using these forces that can typically be generated by vertical cavity surface emitting laser (VCSEL) arrays, with only a few mW optical powers. T-, Y-, and multi-layered X fluidic channel devices were fabricated by polydimethylsiloxane (PDMS) elastomer molding of channel structures over photolithographically defined patterns using a thick negative photoresist. We have also shown that this optical manipulation technique can be extended to smaller multiple objects by using an optically trapped particle as a handle, or an optical handle. Ultimately, optical manipulation of small particles and biological cells could have applications in biomedical devices for drug discovery, cytometry and cell biology research.  相似文献   
8.
We have studied a 50-year-old white man with chronic urticaria and angioedema who has responded to treatment with cimetidine alone for over 2 yr. In a double-blind, placebo-controlled study, cimetidine alone was at least as effective as chlorpheniramine in relief of urticaria and angioedema. Additionally, cimetidine significantly inhibited (p less than 0.01) the wheal response to histamine when it was compared to placebo. The inhibition of wheal response to histamine by cimetidine was significantly higher (p less than 0.05) than chlorpheniramine. The presence of predominantly H2- rather than H1-histamine receptors in the cutaneous blood vessels may be responsible for the therapeutic effects of cimetidine in this patient.  相似文献   
9.
Summary The angular points are the ligamentous and tendinous structures that reinforce the posteromedial and posterolateral capsule of the knee and share in fixation of the posterior horns of the menisci. They are often damaged in acute injuries and this is usually associated with ruptures of the cruciate and collateral ligaments and may add to the degree of laxity. We describe the normal appearance of these structures in terms of the sectional anatomy, correlated with the lesional appearances of complete and incomplete ruptures and associated meniscal detachments as shown by clinical testing and arthrotomy findings.
IRM des points d'angle du genou : bases anatomiques et applications aux genoux traumatiques
Résumé Les points d'angle sont des structures ligamentaires et tendineuses qui renforcent la capsule postéro-médiale et postéro-latérale et participent à la fixation des cornes postérieures des ménisques. Leurs lésions, fréquentes au cours des traumatismes aigus, sont généralement associées à des ruptures des ligaments croisés et des ligaments collatéraux et peuvent être source d'une aggravation de la laxité. Nous rapportons, en corrélation avec l'anatomie en coupe, l'aspect normal de ces structures, et en corrélation avec les données de l'arthrotomie et du testing les aspects lésionnels observés au cours des traumatismes : ruptures complètes, incomplètes et désinsertions méniscales associées.
  相似文献   
10.
Bulimia and depression   总被引:2,自引:0,他引:2  
In recent years several lines of evidence have emerged suggesting that eating disorders in general, and bulimia in particular, are in some way linked to affective illness. However, there are few data on the frequency of affective syndromes among patients who have anorexia nervosa or bulimia. This report describes the results of semistructured interviews using the Schedule for Affective Disorders and Schizophrenia (SADS) to evaluate the frequency of the current and lifetime diagnoses of affective illness among 50 female patients meeting DSM-III criteria for bulimia. Seventy percent of the patients had, at some time during their lives, met Research Diagnostic Criteria (RDC) for an episode of major depression and 88% had met RDC at some time during their lives for some affective disturbance. The implications of this high frequency of affective disturbance among patients with bulimia are discussed.  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