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   1617篇
  免费   112篇
  国内免费   6篇
耳鼻咽喉   64篇
儿科学   49篇
妇产科学   16篇
基础医学   165篇
口腔科学   37篇
临床医学   116篇
内科学   265篇
皮肤病学   33篇
神经病学   93篇
特种医学   34篇
外科学   464篇
综合类   32篇
预防医学   74篇
眼科学   47篇
药学   124篇
中国医学   4篇
肿瘤学   118篇
  2023年   10篇
  2022年   10篇
  2021年   51篇
  2020年   27篇
  2019年   53篇
  2018年   60篇
  2017年   43篇
  2016年   35篇
  2015年   38篇
  2014年   53篇
  2013年   56篇
  2012年   109篇
  2011年   132篇
  2010年   65篇
  2009年   62篇
  2008年   97篇
  2007年   91篇
  2006年   126篇
  2005年   99篇
  2004年   80篇
  2003年   68篇
  2002年   79篇
  2001年   40篇
  2000年   52篇
  1999年   30篇
  1998年   17篇
  1997年   12篇
  1996年   10篇
  1995年   7篇
  1994年   8篇
  1993年   4篇
  1992年   8篇
  1991年   12篇
  1990年   13篇
  1989年   12篇
  1988年   7篇
  1987年   4篇
  1986年   2篇
  1985年   5篇
  1984年   5篇
  1983年   5篇
  1982年   2篇
  1981年   7篇
  1979年   4篇
  1978年   3篇
  1974年   2篇
  1973年   2篇
  1970年   3篇
  1966年   2篇
  1957年   2篇
排序方式: 共有1735条查询结果,搜索用时 156 毫秒
1.

Background

Glucocorticoids play essential roles in the treatment of childhood acute lymphoblastic leukaemia (ALL); however, treatment with these agents can result in severe side-effects. This study, the first of its kind in a Saudi population, investigates associations of ABCB1 gene polymorphisms (pharmacodynamics and pharmacokinetic) with the development of toxicity and side effects (glucose abnormality, liver toxicity and infection) in a small population of Saudi children with ALL.

Methods

Three single nucleotide polymorphisms (SNPs) of the ABCB1 gene (rs 3213619 T129C, rs 2032582 G2677T and rs1045642 C3435T) were analysed in 70 Saudi children with ALL and 60 control subjects. Participants were treated according to the ALL 2000 study protocol. Toxicities were assessed and associations with genotypes were evaluated according to Common Toxicity Criteria (NCI-CTC).

Results

Significant associations were observed among carriers and the mutated genotype C3435T (ABCB1), which had an incidence of infection (p?=?0.05). Although no correlations were found between liver toxicity and glucose abnormalities for patients carrying ABCB1 SNPs, risk factors for liver toxicity were elevated by a factor of three for patients carrying the SNP G2677T, OR 3.00 (1.034–8.702). The risk factor of glucose abnormality toxicity for the patients carring T129C were increased three times OR 3.06 (0.486–19.198).

Conclusions

In terms of infection incidence, polymorphism C3435T may contribute to potential life-threatening infections during paediatric ALL therapy, through glucocorticoid usage.  相似文献   
2.
3.
4.
Undifferentiated malignant SMARCA4‐deficient neoplasms are rare, recently characterized, high grade, potentially lethal malignancies. Such tumors are characterized by the loss of BRG1 encoded by SMARCA4, a key component of the Switch/Sucrose Non‐Fermenting (SWI/SNF) chromatin remodeling complex. As this complex, also referred as BAF (BRG1/BRM associated factors) complex, is involved in the epigenetic control of hundreds of genes, including those involved in lineage‐specific differentiation, BAF‐deficient tumors, show minimal or no differentiation and are difficult to classify. Their fine needle aspiration (FNA) cytologic features are still poorly defined. Here, we describe a 70‐year‐old man who presented with thickening of the wall of the distal esophagus and stomach and multiple liver and lung lesions. Liver FNA showed relatively uniform dispersed malignant cells with high nucleus: cytoplasm ratio, scant microvacuolated cytoplasm, eccentric nuclei and prominent nucleoli. Mitoses, necrotic debris, nuclear streak artifact, “ghost cells” and focal rhabdoid cytoplasmic inclusions were also present. The liver core biopsy and GI biopsies demonstrated sinusoidal and respectively submucosal involvement by a high grade undifferentiated malignant neoplasm. The tumor cells were negative for all applied markers on immunohistochemistry and flow cytometry, and only showed CD138 and weak PAX5 staining. After an initial diagnosis of hematolymphoid neoplasm, additional stains showed intact INI1 protein and loss of BRG1 protein immunoexpression, establishing the accurate diagnosis. This case highlights the difficulties and potential pitfalls encountered in the FNA diagnosis of BAF‐deficient tumors, the accurate diagnosis of which is important due to their lack of response to conventional therapy and potential response to targeted therapy.  相似文献   
5.

Background

Nocturnal enuresis (NE) is a common symptom in children worldwide. International Children’s Continence Society (ICCS) defines enuresis as either mono-symptomatic, NE with lower urinary tract symptoms and NE with co-morbid conditions. The objectives of this study were to determine the frequencies and types of NE and associated symptoms and conditions in children aged 5 to 16?years based on ICCS criteria.

Methods

A multi-center cross sectional study was conducted between November 2012 and December 2013 in the primary care clinics of four hospitals in Karachi. Children aged five to fifteen years were included through consecutive sampling. Informed consent was obtained from the parents and a pre-coded semi-structured questionnaire was used to obtain the information. Data was entered on SPSS version 20.0 and multivariable logistic regression analysis was used for data analysis.

Results

Out of 429 children aged between five and sixteen years, 243(56.9%) were boys and the remaining 186(43.1%) were girls. One hundred and eighty three children (43%) had nocturnal enuresis (NE). Forty four (10.3%), had mono-symptomatic NE, 57(31.1%) had associated lower urinary tract symptoms (NE-LUTS), whereas 30 (16.3%) had NE with a co-morbid condition. Fifty two (28.4%) NE’s had at least one of both LUTS and a co-morbid condition. Out of the 246(57%) non-enuretic’s, 31(12.6%) had a LUTS, 95(38.6%) had a co-morbid condition and 57(23.2%) had at least one of both LUTS and a co-morbid condition. The remaining 63 (25.6%) were symptom free. Increased voiding frequency, urgency, dysuria, suprapubic pain and daytime incontinence were the LUTS significantly associated with NE. Co-morbid conditions significantly associated with NE included constipation, congenital defects, developmental delay, and learning and sleep problems.

Conclusion

Although NE can be an only symptom, it is often associated with lower urinary tract symptoms like dysuria, urgency, suprapubic pain, and daytime incontinence. Children presenting with NE often have co-morbid conditions like constipation, urinary tract infection, sleep disorders, and developmental delay. Many children presenting with these conditions as the primary complaint may also have NE. It should be addressed as unrecognized and untreated NE can cause additional morbidity and distress.
  相似文献   
6.
The 22q11.2 deletion syndrome is characterized by wide phenotypic variability, frequently involving characteristic craniofacial features, cardiac malformations, and learning difficulties. Skeletal anomalies are also common and include an obtuse angle of the cranial base, retrognathia, and cervical spine abnormalities. Despite these anomalies, sleep-disturbed breathing is not reported frequently in patients with 22q11.2 deletion syndrome. We describe a patient with an obstructive sleep disturbance that was successfully treated with a tonsillectomy followed by mandibular distraction osteogenesis. She also had central sleep apnea, initially attributed to spinal cord impingement from cervical instability. Posterior cervical fusion was associated with a decrease in the number of central apneic events.  相似文献   
7.
8.
9.
The hypothesis of this study was that sustained activity of the Nod-like receptor protein (NLRP)-3 inflammasome in wounds of diabetic humans and mice contributes to the persistent inflammatory response and impaired healing characteristic of these wounds. Macrophages (Mp) isolated from wounds on diabetic humans and db/db mice exhibited sustained inflammasome activity associated with low level of expression of endogenous inflammasome inhibitors. Soluble factors in the biochemical milieu of these wounds are sufficient to activate the inflammasome, as wound-conditioned medium activates caspase-1 and induces release of interleukin (IL)-1β and IL-18 in cultured Mp via a reactive oxygen species–mediated pathway. Importantly, inhibiting inflammasome activity in wounds of db/db mice using topical application of pharmacological inhibitors improved healing of these wounds, induced a switch from proinflammatory to healing-associated Mp phenotypes, and increased levels of prohealing growth factors. Furthermore, data generated from bone marrow–transfer experiments from NLRP-3 or caspase-1 knockout to db/db mice indicated that blocking inflammasome activity in bone marrow cells is sufficient to improve healing. Our findings indicate that sustained inflammasome activity in wound Mp contributes to impaired early healing responses of diabetic wounds and that the inflammasome may represent a new therapeutic target for improving healing in diabetic individuals.  相似文献   
10.

Background

Enhanced recovery protocols have been proven to decrease complications and hospital stay following elective colorectal surgery. However, these principles have not yet been reported for urgent surgery procedures. We aimed to assess our initial experience with urgent colectomies performed within an established enhanced recovery pathway.

Methods

In a prospective cohort study, all patients undergoing colonic resection between April 2012 and March 2013 were treated according to a standardized enhanced recovery protocol. Urgent surgeries were compared with the elective procedures with regards to baseline characteristics, compliance with enhanced recovery items, and clinical outcome.

Results

Patients (N = 28) requiring urgent colonic resection were included and compared with patients undergoing elective colectomy (N = 63). Overall compliance with the protocol was 57 % for the urgent compared with 77 % for the elective procedures (p = 0.006). The pre-operative compliance was 64 versus 96 % (p < 0.001), the intra-operative compliance was 77 versus 86 % (p = 0.145), and the post-operative compliance was 49 versus 67 % (p = 0.015), for the urgent and elective resections, respectively. Overall, 18 urgent patients (64 %) and 32 elective patients (51 %) developed postoperative complications (p = 0.261). Median postoperative length of stay was 8 days in the urgent setting compared with 5 days in the elective setting (p = 0.006).

Conclusions

Many of the intra-operative and post-operative enhanced recovery items can also be applied to urgent colectomy, entailing outcomes that approach the results achieved in the elective setting.  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