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   2165篇
  免费   114篇
  国内免费   12篇
耳鼻咽喉   6篇
儿科学   107篇
妇产科学   46篇
基础医学   184篇
口腔科学   31篇
临床医学   121篇
内科学   449篇
皮肤病学   101篇
神经病学   149篇
特种医学   63篇
外科学   294篇
综合类   91篇
一般理论   3篇
预防医学   134篇
眼科学   160篇
药学   231篇
中国医学   9篇
肿瘤学   112篇
  2023年   16篇
  2022年   22篇
  2021年   95篇
  2020年   72篇
  2019年   83篇
  2018年   87篇
  2017年   55篇
  2016年   91篇
  2015年   94篇
  2014年   105篇
  2013年   162篇
  2012年   206篇
  2011年   206篇
  2010年   119篇
  2009年   95篇
  2008年   133篇
  2007年   100篇
  2006年   75篇
  2005年   80篇
  2004年   62篇
  2003年   49篇
  2002年   58篇
  2001年   25篇
  2000年   24篇
  1999年   22篇
  1998年   9篇
  1997年   5篇
  1996年   3篇
  1995年   2篇
  1994年   5篇
  1993年   3篇
  1992年   16篇
  1991年   16篇
  1990年   14篇
  1989年   6篇
  1988年   11篇
  1987年   4篇
  1986年   3篇
  1985年   5篇
  1984年   4篇
  1982年   2篇
  1980年   7篇
  1979年   3篇
  1978年   4篇
  1977年   7篇
  1976年   5篇
  1975年   4篇
  1972年   3篇
  1966年   5篇
  1965年   3篇
排序方式: 共有2291条查询结果,搜索用时 296 毫秒
1.
Microbial co-infections are another primary concern in patients with coronavirus disease 2019 (COVID-19), yet it is an untouched area among researchers. Preliminary data and systematic reviews only show the type of pathogens responsible for that, but its pathophysiology is still unknown. Studies show that these microbial co-infections are hospital-acquired/nosocomial infections, and patients admitted to intensive care units with invasive mechanical ventilation are highly susceptible to it. Patients with COVID-19 had elevated inflammatory cytokines and a weakened cell-mediated immune response, with lower CD4+ T and CD8+ T cell counts, indicating vulnerability to various co-infections. Despite this, there are only a few studies that recommend the management of co-infections.  相似文献   
2.
3.

Background

Multiple myeloma (MM) is a hematologic malignancy of plasma cell origin. MM primarily affects bone marrow, but extramedullary sites can also be involved. Myelomatous pleural effusion (MPE) is an atypical and rare complication of MM. We aimed to systematically study the incidence and clinicopathologic profile of patients with MPE in a real-world setting.

Patients and Methods

In this retrospective study, 415 consecutive patients with MM managed at a tertiary care center in North India during a study period of January 1, 2010 to December 31, 2015 were evaluated for MPE. The patients with MPE were analyzed for their clinical profile, diagnosis, treatment, and outcomes.

Results

Of these 415 patients, 11 (2.65%) patients had MPE. The median age of the study population was 50 years with male preponderance. The majority of these patients had immunoglobin (Ig)G Kappa disease. All patients had higher than International Staging System stage I disease. MPE was a presenting feature at MM diagnosis in 45.45% (n = 5) of the patients, whereas the rest developed MPE during follow-up. MPE presented predominantly (81.8%) as a unilateral effusion. Concurrent extramedullary involvement at other site was seen in 45.45% (n = 5), with 3 (27%) patients having concurrent myelomatous ascites. Six of these were managed aggressively, whereas 5 patients opted for palliation. The outcomes were dismal (90.9% mortality), with a median survival of 2.47 months.

Conclusion

MPE is a rare entity, and positive outcomes of therapy remain low with dismal prognosis.  相似文献   
4.
‘Paediatric bipolar disorder’ (PBD) remains controversial; because it is based on the hypothesis that bipolar disorder (BD) often begins in childhood with atypical forms of mania. A meta-analysis of 12 epidemiological surveys found a high prevalence of PBD among children and adolescents worldwide (1.8%), however, our study of the measurement issues (Child and Adolescent Mental Health, 23, 2018, 14) found that PBD rates were lower than claimed. Our findings are consistent with the developmental trajectory of BD, as described by most longitudinal studies of high-risk offspring. BD is extremely rare in childhood with nearly all index manic/hypomanic episodes being in midadolescence or later. Treatment for BD should not commence until the first well-defined manic/hypomanic episode, because children and younger adolescents are extremely sensitive to the side effects of second-generation antipsychotics including weight gain, metabolic syndrome, extrapyramidal side effects and the risk of cerebral atrophy, as observed in studies of juvenile animals.  相似文献   
5.
Neuronal mitochondrial dysfunction increases inflammatory mediators and leads to free radical generation and anti-oxidant enzymatic alterations,which are major neuropathological hallmarks responsible for autism.Mitochondrial dysfunction in autism is associated with decreased ATP levels due to reduced levels of cyclic adenosine monophosphate.Rat models of autism were established by intracerebroventricular injection of propionic acid.These rat models had memory dysfunction,decreased muscle coordination and gait imbalance.Biochemical estimation of propionic acid-treated rats showed changes in enzyme activity in neuronal mitochondrial electron transport chain complexes and increases in pro-inflammatory cytokines,oxidative stress and lipid biomarkers.Oral administration of 10,20 and 30 mg/kg adenylate cyclase activator forskolin for 15 days reversed these changes in a dose-dependent manner.These findings suggest that forskolin can alleviate neuronal mitochondrial dysfunction and improve neurological symptoms of rats with autism.This study was approved by the RITS/IAEC,SIRSA,HARYANA on March 3,2014(approval No.RITS/IAEC/2014/03/03).  相似文献   
6.
7.
8.
Although, a large proportion of pathogenic bacteria gets eliminated from hosts after antibiotic treatment, a fraction of population confronts against such effects and undergoes growth arrest to form persisters. Persistence in bacteria is a dormant physiological state where cells escape the effects of antimicrobials as well as other host immune defences without any genetic mutations. The state of dormancy is achieved through various complex phenomena and it is known that a gene pair named as toxin–antitoxin (TA) acts as a key player of persister cell formation where the toxin is activated either stochastically or after an environmental insult, thereby silencing the physiological processes. However, the controversial role of TA modules in persister cell formation has also been documented with reasonable clarity. Persisters may revert back from state of quiescence and regrow when conditions become favourable for their propagation. Therefore, the elimination of dormant bacteria is crucial, and currently, research interest is highly focussed on developing several antipersister strategies that may kill persister bacteria by targeting different molecules . It is worth examining these targets to develop appropriate therapeutic interventions against bacterial infections and it is believed that earmarking TA system can be a novel approach for resuscitation of persisters. In this review, we discussed the role of TA modules in mediating persistence with highlighting on the debatable issues regarding contribution of these modules in dormant bacteria formation. Furthermore, we discussed if these modules in bacteria can be targeted for successful elimination of dormant persister cells.  相似文献   
9.
Undergraduate medical education has expanded substantially in recent years, through both establishing new programs and increasing student numbers in existing programs. This expansion has placed pressure on the capacity for training students in clinical placements, raising concerns about the risk of dilution of experience, and reducing work readiness. The concerns have been greatest in more traditional environments, where clinical placements in large academic medical centers are often the “gold standard”. However, there are ways of exposing medical students to patient interactions and clinical supervisors in many other contexts. In this paper, we share our experiences and observations of expanding clinical placements for both existing and new medical programs in several international locations. While this is not necessarily an easy task, a wide range of opportunities can be accessed by asking the right questions of the right people, often with only relatively modest changes in resource allocation.  相似文献   
10.
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