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   1712篇
  免费   90篇
  国内免费   4篇
耳鼻咽喉   25篇
儿科学   64篇
妇产科学   34篇
基础医学   159篇
口腔科学   44篇
临床医学   122篇
内科学   364篇
皮肤病学   21篇
神经病学   205篇
特种医学   40篇
外科学   255篇
综合类   16篇
一般理论   1篇
预防医学   84篇
眼科学   48篇
药学   170篇
中国医学   8篇
肿瘤学   146篇
  2024年   2篇
  2023年   14篇
  2022年   27篇
  2021年   75篇
  2020年   40篇
  2019年   56篇
  2018年   71篇
  2017年   58篇
  2016年   77篇
  2015年   60篇
  2014年   116篇
  2013年   118篇
  2012年   175篇
  2011年   178篇
  2010年   94篇
  2009年   66篇
  2008年   122篇
  2007年   95篇
  2006年   93篇
  2005年   79篇
  2004年   70篇
  2003年   49篇
  2002年   31篇
  2001年   1篇
  2000年   5篇
  1999年   4篇
  1998年   7篇
  1997年   3篇
  1996年   2篇
  1995年   4篇
  1994年   1篇
  1993年   2篇
  1992年   1篇
  1991年   3篇
  1990年   2篇
  1989年   1篇
  1988年   1篇
  1983年   1篇
  1977年   1篇
  1965年   1篇
排序方式: 共有1806条查询结果,搜索用时 31 毫秒
991.
992.
Copper deficiency is an uncommonly reported complication of celiac disease that has not received much attention in recent years. Copper deficiency may result in anemia and thrombocytopenia and also irreversible myeloneuropathy if it is not detected and treated appropriately. The prevalence of copper deficiency in patients with celiac disease is unknown. We describe 5 patients with celiac disease and associated copper deficiency diagnosed at our institution in recent years. All 5 patients had neurologic complications of copper deficiency and 3 patients also presented with hematologic abnormalities. We also review the literature regarding copper deficiency in celiac disease.  相似文献   
993.
994.
Neuroimaging, in many patients with dengue encephalopathy, may reveal periventricular signal changes. We report a 25-year-old man, who presented with altered sensorium. Dengue-IgM test in serum was positive. Cerebrospinal fluid examination was normal. MRI brain revealed presence of bilateral parieto-occipital intraparenchymal bleed with mass effect. Neuroimaging was consistent with posterior reversible encephalopathy syndrome. We report posterior reversible encephalopathy syndrome in a normotensive patient with dengue encephalopathy and systemic metabolic alterations.  相似文献   
995.

Purpose of Review

Despite professional society recommendations and data supporting use, cystoscopy continues to be an underutilized tool by a gynecologist in the operating room and in the office. Traditional cystoscopy may present challenges for use by the gynecologic surgeon. CystoSure? is a unique catheter-based access sheath which makes cystoscopy safe, simple, and standardized in the operating room, at the office, and by the bedside.

Recent Findings

Cystoscopy is a cornerstone of urogynecologic office evaluation while also playing a critical role in the intraoperative assessment of the lower urinary tract in gynecologic surgery. Routine cystoscopy after major gynecologic surgery has been advocated by many authorities. Traditional cystoscopy is complicated, costly, and time-consuming and is restrictive in its utility. Adoption is still lagging recommendations. A more user-friendly system that facilitates the performance of this integral procedure may increase adoption of cystoscopy amongst gynecologists in the office and operating room when indicated.

Summary

CystoSure? enables clinicians to perform comprehensive bladder evaluation in the office, nurses to perform hands-free post-procedure voiding trials and outreach programs to provide bladder diagnostics in remote locations—all in a simple and cost-effective package with shortened learning curve.
  相似文献   
996.
The present study was aimed to identify the underlying mechanisms of improper renal function in Leishmania donovani infection that causes VL. Mice (BALB/c) were infected with L. donovani and different parameters for proteinuria were assessed. The levels of superoxide anion (O2?), hydrogen peroxide (H2O2), lipid peroxidation (MDA), inflammatory cytokines, and toll-like receptor (TLR) 2 and 4 expression were found significantly elevated at 60th day in these animals and declined at 90th day post infection. However, TGF-β and caspase 3 activities were higher at 90th day in comparison to 60th day post infection. These findings suggested that exacerbated inflammatory conditions correlate with abnormal renal functions in L. donovani infection, which is further augmented by activated TLRs expressions by circulating leishmanial antigens. Further, the increased levels of TGF-β and caspase 3 at 90th day suggested TGF-β mediated apoptotic cell death of renal and other cells during later stages of disease that may eventually result in release of host and parasitic factors in urine during visceral leishmaniasis.  相似文献   
997.
Argyreia speciosa commonly known as Vridha daraka in Sanskrit is one of the important plants used in indigenous system of medicine. The root is regarded as an alternative tonic and useful in the diseases of nervous system. To confirm the veracity of aforementioned claim, we have evaluated the anticonvulsant effect of the extract. In this investigation, the mice were pretreated with different doses of Argyreia speciosa extract (100, 200, 400 mg/kg) for 10 days and then, they were subjected to either pentylenetetrazole (80 mg/kg) or maximal electroshock seizures (50 mA, 0.2 s) treatment. The hydroalcoholic extract of Argyreia speciosa at the dose of 200 and 400 mg/kg significantly delayed the latency to the onset of first clonus as well as onset of death in unprotected mice and exhibited protection in 16.66% and 33.33% of pentylenetetrazole treated mice respectively. Whereas in case of maximal electroshock-seizures, the dose of 200 and 400 mg/kg significantly reduced the duration of hind limb extension and both the doses were statistically found to be equipotent. The reference standards, clonazepam (0.1 mg/kg) and phenytoin (20 mg/kg) provided complete protection. Thus, present study revealed anticonvulsant effect of Argyreia speciosa against pentylenetetrazole- and maximal electroshock-induced convulsions in mice.  相似文献   
998.
Roses are one of the most important groups of ornamental plants and their fruits and flowers are used in a wide variety of food, nutritional products and different traditional medicines. The antioxidant activity of methanolic extracts from fresh flowers of three rose species (Rosa damascena, Rosa bourboniana and Rosa brunonii) was evaluated by 1,1-diphenyl-2-picryl hydrazyl (DPPH) free-radical method. The ability to scavenge DPPH radical was measured by the discoloration of the solution. The methanolic extract from R. brunonii exhibited maximum free-radical-scavenging activity (64.5 ± 0.38%) followed by R. bourboniana (51.8 ± 0.46%) and R. damascena (43.6 ± 0.25%) at 100 μg/ml. Simultaneously, ultra-performance liquid chromatography coupled with electrospray ionization-quadrupole time-of-flight mass spectrometry (UPLC-ESI-QTOF-MS) was used to study phenolic composition in the methanolic extracts from the fresh flowers of rose species. The phenolic constituents were further investigated by direct infusion-ESI-QTOF-MS/MS in negative ion mode. Characteristic Electrospray ionization tandem mass spectrometry (ESI-MS/MS) spectra with other diagnostic fragment ions generated by retro Diels–Alder (RDA) fragmentation pathways were recorded for the flavonoids. Distinct similarities were observed in the relative distribution of polyphenolic compounds among the three species. The dominance of quercetin, kaempferol and their glycosides was observed in all the three species.  相似文献   
999.
Distribution and gene-environment interaction of EPHX1 polymorphism was evaluated in 175 lung cancer patients and 322 controls from north India. Two novel non-synonymous, Lys117Arg and Leu263Phe, and twelve single nucleotide polymorphisms were identified in the present study. Binary logistic regression analysis showed association of polymorphism Tyr113His with increased risk of lung cancer (OR = 2.2, 95% CI = 1.2-4.0, p < .05). Gene-environment interaction revealed that patients with His113His and smoking habit had significantly greater risk of lung cancer (OR = 4.52, 95% CI = 0.93-43.05, p < .05). Present study provided evidence that EPHX1 polymorphism is associated with lung cancer susceptibility in Indian population.  相似文献   
1000.
Obesity is rapidly becoming a pandemic and is associated with increased carcinogenesis. Obese populations have higher circulating levels of leptin in contrast to low concentrations of adiponectin. Hence, it is important to evaluate the dynamic role between adiponectin and leptin in obesity-related carcinogenesis. Recently, we reported the oncogenic role of leptin including its potential to increase tumor invasiveness and migration of hepatocellular carcinoma (HCC) cells. In the present study we investigated whether adiponectin could antagonize the oncogenic actions of leptin in HCC. We employed HCC cell lines HepG2 and Huh7, the nude mice-xenograft model of HCC, and immunohistochemistry data from tissue-microarray to demonstrate the antagonistic role of adiponectin on the oncogenic actions of leptin. Adiponectin treatment inhibited leptin-induced cell proliferation of HCC cells. Using scratch-migration and electric cell-substrate impedance-sensing-based migration assays, we found that adiponectin inhibited leptin-induced migration of HCC cells. Adiponectin treatment effectively blocked leptin-induced invasion of HCC cells in Matrigel invasion assays. Although leptin inhibited apoptosis in HCC cells, we found that adiponectin treatment induced apoptosis even in the presence of leptin. Analysis of the underlying molecular mechanisms revealed that adiponectin treatment reduced leptin-induced Stat3 and Akt phosphorylation. Adiponectin also increased suppressor of cytokine signaling (SOCS3), a physiologic negative regulator of leptin signal transduction. Importantly, adiponectin significantly reduced leptin-induced tumor burden in nude mice. In HCC samples, leptin expression significantly correlated with HCC proliferation as evaluated by Ki-67, whereas adiponectin expression correlated significantly with increased disease-free survival and inversely with tumor size and local recurrence. CONCLUSION: Collectively, these data demonstrate that adiponectin has the molecular potential to inhibit the oncogenic actions of leptin by blocking downstream effector molecules.  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