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   1198篇
  免费   84篇
  国内免费   19篇
耳鼻咽喉   21篇
儿科学   23篇
妇产科学   58篇
基础医学   158篇
口腔科学   29篇
临床医学   115篇
内科学   326篇
皮肤病学   44篇
神经病学   96篇
特种医学   27篇
外科学   129篇
综合类   3篇
预防医学   56篇
眼科学   27篇
药学   78篇
肿瘤学   111篇
  2023年   14篇
  2022年   24篇
  2021年   50篇
  2020年   35篇
  2019年   42篇
  2018年   52篇
  2017年   47篇
  2016年   39篇
  2015年   40篇
  2014年   65篇
  2013年   74篇
  2012年   91篇
  2011年   80篇
  2010年   42篇
  2009年   40篇
  2008年   81篇
  2007年   70篇
  2006年   60篇
  2005年   54篇
  2004年   49篇
  2003年   59篇
  2002年   44篇
  2001年   10篇
  2000年   9篇
  1999年   19篇
  1998年   14篇
  1997年   9篇
  1996年   14篇
  1995年   5篇
  1994年   5篇
  1993年   7篇
  1992年   12篇
  1991年   3篇
  1990年   8篇
  1989年   3篇
  1988年   5篇
  1987年   5篇
  1986年   2篇
  1985年   3篇
  1984年   3篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1975年   2篇
  1972年   2篇
  1971年   2篇
  1970年   2篇
  1966年   1篇
排序方式: 共有1301条查询结果,搜索用时 31 毫秒
61.
62.
The repair of large segmental bone defects due to trauma, inflammation and tumor surgery remains a major clinical problem. Animal models were developed to test bone repair by tissue engineering approaches, mimicking real clinical situations. Studies differed with regard to animals (dog, sheep, goat), treated bone (femur, tibia, mandible), chemistry and structure of the scaffolds. Still, an advantage in the bone formation and in the healing of the segmental defect was always observed when scaffolds were seeded with bone marrow derived stromal cells (BMSCs). In the year 1998 was performed the first implantation of a porous ceramic construct in a bone segmental defect of a patient; it was the first construct seeded with cultured autologous osteogenic cells. Since then, only few other similar cases were treated by the same approach. However, in other fields, such as oral and maxillofacial surgery, injectable cells/platelet-rich plasma composites have been used as grafting materials for maxillary sinus floor augmentation and/or onlay plasty. More recently, the reconstruction of a human mandible was also reported by means of a bone-muscle-flap in vivo prefabrication technique, where the patient served as his own bioreactor. Indeed continuous implementations test and provide new means of defects treatment and cure. However, based on results so far obtained in animal models and pilot clinical studies, one can affirm that the bone tissue engineering approaches, although successful in most cases, need further validation before a wide application in clinics. In particular, the supply of oxygen and nutrients to the cells in the inner part of the implanted scaffolds remains a major concern, requiring additional investigations.  相似文献   
63.
Bloodstream infections (BSIs) are common, however international guidelines are available only for methicillin-resistant Staphylococcus aureus (MRSA) bacteraemia and candidaemia. This international ESCMID cross-sectional survey, open from December 2016 to February 2017, explored the management of BSIs by infection specialists. All infection specialists (senior or trainees) giving at least weekly advice on positive blood cultures could participate. Their practices were evaluated using six clinical vignettes presenting uncomplicated BSI cases. A total of 616 professionals from 56 countries participated [333/616 (54%) infectious diseases specialists, 188/616 (31%) clinical microbiologists], of whom 76% (468/616) were members of an antimicrobial stewardship team. Large variations in practice were noted, in particular for the Escherichia coli, Enterococcus faecalis and Pseudomonas aeruginosa vignettes. Echocardiography was considered standard of care by 81% (373/459) of participants for MRSA, 78% (400/510) for methicillin-susceptible S. aureus and 60% (236/395) for Candida albicans. Antimicrobial combination therapy was recommended by 2% (8/360) of respondents for C. albicans, 11% (43/378) for E. coli, 27% (114/420) for MRSA and 39% (155/393) for E. faecalis. Intravenous-to-oral switch was considered in 68% (285/418) for MRSA, 79% (306/388) for E. faecalis, 72% (264/366) for P. aeruginosa and 75% (270/362) for C. albicans. In multivariable analysis, IDSA guideline-compliant practice was more frequent among participants belonging to an antimicrobial stewardship team (aOR?=?1.7, P?=?0.018 for the MRSA vignette; and aOR?=?2.0, P?=?0.008 for the candidaemia vignette). This survey showed large variations in practice among infection specialists. International guidelines on management of BSI are urgently needed.  相似文献   
64.

Objectives

We hypothesised that treatment with a tigecycline-based antimicrobial regimen for intra–abdominal infection (IAI) could be associated with lower rates of subsequent carbapenem-resistant Enterobacteriaceae (CRE) colonisation or Clostridium difficile infection (CDI) compared with a meropenem-based regimen.

Methods

We performed a retrospective, single-centre, matched (1:1) cohort analysis of all patients who received at least 5 days of empirical or targeted tigecycline (TIG)- or meropenem (MER)-based treatment regimens for IAI over a 50-month period. Patients with previous CRE colonisation and CDI were excluded. Risk factors for CRE and CDI were assessed with a Cox regression model that included treatment duration as a time-dependent variable. Thirty-day mortality was assessed with Kaplan-Meier curves.

Results

We identified 168 TIG-treated and 168 MER-treated patients. The cumulative incidence rate ratio of CDI was 10-fold lower in TIG-treated vs. MER-treated patients (incidence rate ratio [IRR] 0.10/1000 patient-days, 95%CI 0.002–0.72, P?=?0.007), but similar incidence rates were found for CRE colonisation (IRR 1.39/1000 patient-days, 95%CI 0.68–2.78, P?=?0.36). In a multivariate Cox regression model, the receipt of a TIG- vs. MER-based regimen was associated with significantly lower rates of CDI (HR 0.07, 95%CI 0.03–0.71, P?=?0.02), but not CRE (HR 1.12, 95% CI 0.45–2.83, P?=?0.80). All-cause 30-day mortality was similar in the two groups (P?=?0.46).

Conclusion

TIG-based regimens for IAI were associated with a 10-fold lower incidence of CDI compared with MER-based regimens, but there was no difference in the incidence of CRE colonisation.  相似文献   
65.
Introduction: Pharmacotherapy for the treatment of depressive disorders in Alzheimer’s Disease (AD) represents a clinical challenge. pharmacological options are often attempted after a period of watchful waiting (8–12 weeks). monoaminergic antidepressant drugs have shown only modest or null clinical benefits, maybe because the etiology of depressive symptoms in ad patients is fundamentally different from that of nondemented subjects.

Areas covered: The following article looks at the selective serotonin reuptake inhibitor sertraline, which is one of the most frequently studied antidepressant medications in randomized controlled trials (RCTs). It also discusses many other pharmacological approaches that have proven to be inadequate (antipsychotics, acetylcholinesterase inhibitors, anticonvulsants, hormone replacement therapy) and new drug classes (mainly affecting glutamate transmission) that are being studied for treating depression in AD. It also gives discussion to the phase II RCT on the alternative drug S47445 and the potential effect on cognition of the multimodal antidepressant vortioxetine in older depressed patients. Finally, it discusses the N-methyl-D-aspartate antagonist ketamine.

Expert opinion: The present RCT methodologies are too disparate to draw firm conclusions. Future studies are required to identify effective and multimodal pharmacological treatments that efficiently treat depression in AD. Genotyping may boost antidepressant treatment success.  相似文献   

66.
The Athlete Biological Passport (ABP) refers to the collection of data related to an individual athlete. The ABP contains the Haematological Module and the Steroidal Module, which are used for the longitudinal monitoring of variables in blood and urine, respectively. Based on changes in these variables, a statistical model detects outliers which indicate doping use and guide further targeted testing of the athlete. Presently, athletes can access their data of the Haematological Module in the Anti‐Doping Administration and Management System (ADAMS). However, granting athletes access to this data has been a matter of debate within the anti‐doping community. This article investigates whether an athlete has a right to access the contents of their ABP profile. We approached this discussion by comparing the nature of ABP data with that of forensic and medical data and touched on important concerns with ABP data disclosure to athletes such as potentially allowing for the development of alternative doping techniques to circumvent detection; and making athletes vulnerable to pressure by the media to publicly release their data. Furthermore, given that ABP data may contain medically relevant information that can be used to diagnose disease, athletes may over‐interpret its medical significance and wrongly see it as a free health check. We argue that safeguarding the integrity of the ABP system must be seen as the most essential element and thus a departure from immediate data disclosure is necessary. Two different strategies for delayed data disclosure are proposed which diminish the chances of ABP data being misused to refine doping techniques.  相似文献   
67.
Infliximab, a tumor necrosis factor-alpha inhibitor, is increasingly used for the therapy of different inflammatory conditions. We report the first case of cryptococcal meningitis in a patient treated with infliximab and other immunosuppressive agents, and review a further 5 reported cryptococcal infections. All of them involved fungal pneumonia. Outcome was favorable in all cases.  相似文献   
68.
The outcome of steroid-dependent or frequently relapsing nephrotic syndrome of minimal change disease (MCD), mesangial proliferative GN (MesGN), or FSGS may be poor and with major treatment toxicity. This academic, multicenter, off-on trial (ClinicalTrials.gov #NCT00981838) primarily evaluated the effects of rituximab therapy followed by immunosuppression withdrawal on disease recurrence in 10 children and 20 adults with MCD/MesGN (n=22) or FSGS who had suffered ≥2 recurrences over the previous year and were in steroid-induced remission for ≥1 month. Participants received one dose (n=28) or two doses of rituximab (375 mg/m2 intravenously). At 1 year, all patients were in remission: 18 were treatment-free and 15 never relapsed. Compared with the year before rituximab treatment, total relapses decreased from 88 to 22 and the per-patient median number of relapses decreased from 2.5 (interquartile range [IQR], 2–4) to 0.5 (IQR, 0–1; P<0.001) during 1 year of follow-up. Reduction was significant across subgroups (children, adults, MCD/MesGN, and FSGS; P<0.01). After rituximab, the per-patient steroid maintenance median dose decreased from 0.27 mg/kg (IQR, 0.19–0.60) to 0 mg/kg (IQR, 0–0.23) (P<0.001), and the median cumulative dose to achieve relapse remission decreased from 19.5 mg/kg (IQR, 13.0–29.2) to 0.5 mg/kg (IQR, 0–9.4) (P<0.001). Furthermore, the mean estimated GFR increased from 111.3±25.7 to 121.8±29.2 ml/min per 1.73 m2 (P=0.01), with the largest increases in children and in FSGS subgroups. The mean height z score slope stabilized in children (P<0.01). Treatment was well tolerated. Rituximab effectively and safely prevented recurrences and reduced the need for immunosuppression in steroid-dependent or frequently relapsing nephrotic syndrome, and halted disease-associated growth deficit in children.Idiopathic nephrotic syndrome (NS) in children and young adults is almost invariably the clinical counterpart of a continuum of glomerular diseases ranging from the relatively frequent minimal change disease (MCD) and the less frequent mesangial proliferative GN (MesGN), which are predominantly observed in children, to the relatively uncommon FSGS that is observed more frequently in adult patients.1 In a small minority of patients that are generally resistant to immunosuppressive therapies, the disease is due to molecular defects of one of the podocyte genes.2 In all of the other cases, it appears to be immune-mediated, but the pathophysiologic process underlying glomerular injury remains poorly understood.3Independent of the underlying renal pathology, prednisone continues to be the cornerstone treatment at disease onset, achieving remission within 4 weeks in approximately 90% of children with MCD and in 20%–60% of those with FSGS.4,5 However, 60%–70% of patients relapse after steroid tapering or withdrawal, and most require repeat courses of prednisone to achieve remission of recurrent episodes and/or the addition of other immunosuppressive medications, such as calcineurin inhibitors, mycophenolate mofetil, or alkylating agents, to reduce the number of relapses and prevent major side effects of steroid treatment.6 According to their relapse rate, these patients are classically labeled as “steroid-dependent” or “frequently relapsing”. In these patients, serious adverse effects of treatment associate with complications of relapsing episodes of heavy proteinuria. These are the patients in most urgent need of more effective and safer treatment.The possibility of a specific and, hopefully, safer approach to patients with steroid-dependent or frequently relapsing NS emerged in 2004 when the B cell–depleting mAb rituximab was reported to induce remission of proteinuria in a child with frequently relapsing NS secondary to MCD who had received this medication to cure a supervened idiopathic thrombocytopenic purpura.7 Subsequent uncontrolled observations found some effect of rituximab in patients with steroid-dependent or frequently relapsing MCD,811 suggesting that B-cell immunity could play a key role in the pathophysiology of the disease. Controlled studies in support of this hypothesis, however, have been both scanty and almost confined to children12,13 or to patients with MCD who were evaluated in the context of a retrospective, observational design.14 Indeed, less attention was given to adults and patients with FSGS given difficulties in designing adequately powered trials.Here, we designed a longitudinal, off-on study (ClinicalTrials.gov #NCT00981838) to evaluate the efficacy of rituximab in reducing the incidence of relapses and need for steroid and other immunosuppressive medications in children and adults with steroid-dependent or frequently relapsing NS due to MCD, MesGN, or FSGS. To minimize the side effects and costs of rituximab, we abandoned the standard four-dose protocol originally implemented for the treatment of B-cell lymphomas,15 and adopted a new B cell–driven regimen we found to achieve remission of NS in patients with idiopathic membranous nephropathy (IMN) as effectively as the standard protocol, but with fewer side effects and less costs.16  相似文献   
69.
Background and AimsOlder patients with metastatic pancreatic adenocarcinoma (MPDAC) are under-represented in clinical trials.MethodsOur single-center, retrospective study enrolled MPDAC patients ≥ 70 treated with chemotherapyResults105 patients were divided in groups based on the received treatments: 44 gemcitabine or capecitabine monotherapy (A), 34 nabpaclitaxel-gemcitabine (B) 27 4-drugs combinations (gemcitabine, cisplatin, capecitabine plus either nab-paclitaxel or epirubicin or docetaxel) (C). Group A: median age was 78 (70–87) and Karnofsky performance status (KPS) ≥80 was found in 84% of patients; Group B: median age 77 (71–84) and KPS ≥ 80 in 88% of patients; Group C: median age 73 (70–78) and KPS ≥ 80 in 93% of patients. Median OS was 7.9, 11.7 and 14.2 months in group A, B and C respectively; 1 and 2-year OS were 27% and 8% in group A; 44% and 5% in group B; 52% and 22% in group C. When lung metastatic only patients were excluded, patients <75 and ≥ 75 had similar OS in group A (6.4 vs 5.6 months) and in group B (12.3 vs 11.1 months). In group B grade 3 thrombocytopenia, fatigue and peripheral neuropathy were more frequent in patients ≥ 75.ConclusionsIn older patients, combination chemotherapy shows acceptable feasibility and promising efficacy.  相似文献   
70.
A 35-year-old male with an 11-year history of intestinal pseudo-obstruction associated with an idiopathic inflammatory insult of the myenteric plexus and the presence of circulating anti-Hu antibodies developed a neurological syndrome characterized by bilateral hearing loss, deteriorating balance, an unsteady gait and difficulty in estimating distances. A similar neurological syndrome has previously been described in older patients among the paraneoplasic syndromes associated with small-cell lung carcinoma and the presence of circulating anti-Hu antibodies, but never in the rare cancer-free patients with anti-Hu-associated chronic idiopathic intestinal pseudo-obstruction. The patient underwent a steroid treatment. No further episodes of functional intestinal obstruction were observed and, after an initial improvement, the neurological symptoms stabilized, leaving a permanent reduction in hearing function and an unsteady gait. The case shows that an idiopathic inflammatory insult of the myenteric plexus may precede (and perhaps lead to) central nervous system impairment in patients with anti-Hu-associated chronic idiopathic intestinal pseudo-obstruction.  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