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   994篇
  免费   59篇
  国内免费   4篇
耳鼻咽喉   13篇
儿科学   47篇
妇产科学   64篇
基础医学   87篇
口腔科学   122篇
临床医学   84篇
内科学   192篇
皮肤病学   18篇
神经病学   116篇
特种医学   31篇
外科学   114篇
综合类   6篇
预防医学   45篇
眼科学   47篇
药学   44篇
中国医学   1篇
肿瘤学   26篇
  2024年   1篇
  2023年   15篇
  2022年   27篇
  2021年   63篇
  2020年   39篇
  2019年   42篇
  2018年   57篇
  2017年   44篇
  2016年   52篇
  2015年   50篇
  2014年   67篇
  2013年   73篇
  2012年   110篇
  2011年   77篇
  2010年   28篇
  2009年   39篇
  2008年   50篇
  2007年   43篇
  2006年   57篇
  2005年   38篇
  2004年   27篇
  2003年   20篇
  2002年   15篇
  2001年   5篇
  2000年   6篇
  1999年   5篇
  1997年   2篇
  1995年   1篇
  1991年   1篇
  1989年   1篇
  1987年   1篇
  1970年   1篇
排序方式: 共有1057条查询结果,搜索用时 31 毫秒
61.
62.

Objective

The synaptosomal-associated protein of 25 kDa (SNAP-25) gene is a presynaptic plasma membrane protein and an integral component of the vesicle docking and fusion machinery mediating secretion of neurotransmitters. Previously, several studies reported association between SNAP-25 and attention deficit hyperactivity disorder (ADHD). We investigated whether these SNAP-25 polymorphisms (MnlI T/G and DdelI T/C) were also associated with ADHD in the Turkish population.

Methods

Our study comprised unrelated 139 subjects who met DSM-IV criteria for ADHD and 73 controls and all were of Turkish origin. Genetic analyses were performed and patients were evaluated with Wender-Utah Rating Scale and Adult ADD/ADHD DSM IV-Based Diagnostic Screening and Rating Scale.

Results

SNAP-25 DdelI polymorphism was not associated with ADHD but there was a statistically significant difference between ADHD patients and controls for SNAP-25 MnlI polymorphism. For SNAP-25 MnlI polymorphism patients with G/G genotype of the SNAP-25 gene MnlI polymorphism had higher Wender-Utah scores and higher scores in the 1st and 3rd parts of adult ADD/ADHD Scale.

Conclusion

We detected a significant association of the MnlI polymorphism in our ADHD sample which was similar to previous findings. Our study also revealed that SNAP-25 MnlI polymorphism was also associated with symptom severity of ADHD. This study is also, the first report on the association of SNAP-25 with ADHD in the Turkish population.  相似文献   
63.
Forensic Science, Medicine and Pathology - Forensic entomology is a discipline in which insect evidence is used to determine the minimum postmortem interval (PMImin). The insect evidence may also...  相似文献   
64.

Background

Maternal autoimmune thrombocytopenic purpura (AITP) can cause fetal intracranial hemorrhage.

Case report

A 19-year-old primigravida was referred to our institution for prenatally detected ventriculomegaly at 30th week of gestation. Her personal and family histories were unremarkable. Her platelet count was 54?×?109/L. Fetal neurosonography showed intraparenchymal hemorrhage. AITP was diagnosed in the mother and platelet count decreased at 34?×?109/L. Patient was treated with methylprednisolone and intravenous immunoglobulin. She delivered a 2,340-g infant at 37 weeks with elective cesarean section. The platelet count of the newborn was 181?×?109/L and coagulation tests were normal. No antiplatelet specific antibodies were detected in cord blood. Postnatal MRI evaluation confirmed grade IV intracranial hemorrhage. The newborn baby has suffered from mild spasticity and seizures.

Conclusions

Clinicians must be vigilant about the catastrophic fetal complications of maternal AITP; a close follow-up with a multidisciplinary cooperation between obstetricians, hematologists, and neonatologists must be warranted.  相似文献   
65.
Özdemir  Selçuk  Şengez  Burcu  Arslanoğlu  Alper 《Virus genes》2020,56(2):182-193

African monkeys are resistant to HIV-1 infection due to intrinsic restriction mechanisms found in their cells. However, although they can be infected by monkey-adapted modified HIV-1 particles that are designed to overcome known restriction factors, virus numbers drop to undetectable levels in immunocompetent animals. These results indicate the possibility of the presence of yet unidentified factor(s) that restrict HIV-1 in old-world monkey (OWM) cells after integration of the viral genome into the host cell chromosome. In the light of these findings, we hypothesized that OWMs might have evolved resistance mechanism(s) against HIV-1 by switching specific gene(s) on in response to the synthesis of viral proteins in infected cells. In an attempt to mimic post-infection status, we expressed HIV-1 Tat gene in African green monkey cells and compared the whole proteome with normal cells and identified secretory leukocyte protease inhibitor (SLPI), a protein with known extracellular anti-HIV-1 activity, as an over-expressed protein in the presence of HIV-1 Tat protein by 2D-PAGE and mass spectrometry analysis. We also showed that overexpression of SLPI in the presence of HIV-1 Tat was specific to monkey cells. Our results also suggest that SLPI had a previously undiscovered intracellular anti-HIV activity in addition to its extracellular activity.

  相似文献   
66.
Systemic AA amyloidosis is a serious complication of many chronic inflammatory disorders and chronic infections. Renal involvement is seen in the majority of the patients and can lead to end‐stage renal disease. Renal transplantation can be performed in these patients; however, amyloidosis can recur in the transplanted kidneys. On the other hand, de novo AA amyloidosis in renal transplant patients has been rarely reported. We report a 17‐yr‐old patient with end‐stage renal disease due to genitourinary anomalies who developed recurrent pyelonephritis after transplantation. Three yr after transplantation, renal biopsy was performed for proteinuria and AA amyloidosis was identified in the renal allograft. Although rare, chronic infections might cause de novo amyloidosis in renal transplant patients. Therefore, amyloidosis should be kept in mind in those types of patients who present with proteinuria.  相似文献   
67.
Background: YKL‐40, a new acute‐phase protein, is shown to be elevated in inflammatory diseases, such as rheumatoid arthritis, type 2 diabetes mellitus, and coronary artery diseases. However, there is no data indicating a relationship between YKL‐40 and periodontal disease. Interleukin‐6 (IL‐6) is the major regulator of acute‐phase protein synthesis and one of the most studied inflammatory markers in periodontal disease. The purpose of the present study is to evaluate YKL‐40 and IL‐6 levels in gingival crevicular fluid (GCF) and serum of patients with periodontal disease and healthy individuals. Methods: Periodontally healthy individuals (n = 15), patients with gingivitis (n = 15), and patients with severe chronic periodontitis (CP) (n = 15) without any systemic disease were included in the study. Clinical measurements were recorded; GCF and blood samples were obtained from each participant. GCF and serum YKL‐40 and IL‐6 levels were analyzed by enzyme‐linked immunosorbent assay. Statistical analysis was performed by parametric and non‐parametric tests. Results: Total amounts of YKL‐40 and IL‐6 in GCF as well as serum YKL‐40 and IL‐6 levels were significantly higher in patients with gingivitis and CP compared with healthy controls (P <0.01). YKL‐40 levels in GCF and serum as well as serum IL‐6 levels were significantly higher in patients with CP compared with patients with gingivitis (P <0.01). Conclusions: YKL‐40 levels in GCF as well as serum YKL‐40 and IL‐6 levels increased from gingivitis to periodontitis. Within the limits of the present study, the YKL‐40 molecule might be a potential novel inflammatory marker of periodontal disease.  相似文献   
68.
Background: Perianal disease is reported more widely in pediatric Crohn patients than in the past, and has been stated as an independent modifier of the disease behavior. In this study, we aimed to analyze the clinical characteristics and outcomes of fistulising perianal Crohn’s disease (fpCD) in the pediatric age group.Methods: A total number of 149 children with an established diagnosis of inflammatory bowel disease who have been diagnosed before 18 years of age and followed in our tertiary center were revised. Clinical, endoscopic, laboratory, and radiologic data of 50 patients with CD, who had at least 18 months follow-up data, were compiled.Results: Of 50 patients, 26 (52%) were diagnosed as fpCD (38% at onset). More than half of the patients without any notable external orifices around the perianal area were diagnosed as fpCD by an magnetic resonance imaging (MRI). Pediatric fpCD patients had a higher disease activity score and platelet count, lower serum albumin level, and a higher rate of granuloma in the biopsy samples, compared with non-fistulising patients. A considerably high rate of surgical interventions (i.e., seton placement 46% and abscess drainage 15%) was performed in combination with infliximab.Conclusion: Fistulising perianal Crohn’s disease seems to be more common than previously reported in the pediatric age group. A severe course of the disease might serve as a warning for the development of fpCD. A careful physical examination and use of perianal MRI with a high index of suspicion may increase the likelihood of fistula detection, hence may change the treatment strategy.  相似文献   
69.
The treatment of metastatic colorectal cancer (mCRC) harboring BRAF V600 mutations is challenging. These tumors are often refractory to standard treatment. Therefore, the patients may exhibit rapid clinical deterioration, depriving them of the chance to receive salvage therapy. In newly diagnosed patients with good performance status, the administration of an intensive chemotherapy regimen like FOLFOXIRI (5-fluorouracil, leucovorin, oxaliplatin, and irinotecan) along with the antiangiogenic agent bevacizumab can modify this aggressive behavior of the disease and improve patient clinical outcomes. The recently published results of the BEACON (Binimetinib, Encorafenib, and Cetuximab Combined to Treat BRAF-Mutant Colorectal Cancer) study demonstrated that a combination therapy consisting of BRAF, epidermal growth factor receptor, and mitogen-activated protein kinase kinase inhibitors could be a useful second-or third-line alternative. This review summarizes the current treatment strategies for BRAF-mutant mCRC.  相似文献   
70.
Neurological Sciences - Studies have suggested a possible association of migraine and increased risk of ischemic stroke in young adults, particularly in smokers and in women who use oral...  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