全文获取类型
收费全文 | 468篇 |
免费 | 28篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 25篇 |
妇产科学 | 32篇 |
基础医学 | 49篇 |
口腔科学 | 12篇 |
临床医学 | 25篇 |
内科学 | 109篇 |
皮肤病学 | 6篇 |
神经病学 | 24篇 |
特种医学 | 9篇 |
外科学 | 78篇 |
综合类 | 13篇 |
预防医学 | 36篇 |
眼科学 | 5篇 |
药学 | 29篇 |
中国医学 | 5篇 |
肿瘤学 | 38篇 |
出版年
2023年 | 3篇 |
2022年 | 8篇 |
2021年 | 16篇 |
2020年 | 5篇 |
2019年 | 7篇 |
2018年 | 15篇 |
2017年 | 6篇 |
2016年 | 12篇 |
2015年 | 15篇 |
2014年 | 18篇 |
2013年 | 24篇 |
2012年 | 37篇 |
2011年 | 48篇 |
2010年 | 23篇 |
2009年 | 28篇 |
2008年 | 41篇 |
2007年 | 38篇 |
2006年 | 30篇 |
2005年 | 31篇 |
2004年 | 25篇 |
2003年 | 21篇 |
2002年 | 12篇 |
2001年 | 5篇 |
2000年 | 5篇 |
1999年 | 1篇 |
1998年 | 2篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1991年 | 2篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1971年 | 2篇 |
1946年 | 1篇 |
1945年 | 1篇 |
排序方式: 共有498条查询结果,搜索用时 15 毫秒
91.
92.
93.
Puli SR Batapati Krishna Reddy J Bechtold ML Ibdah JA Antillon D Singh S Olyaee M Antillon MR 《World journal of gastroenterology : WJG》2008,14(19):3028-3037
AIM:To evaluate the accuracy of endoscopic ultrasound (EUS), EUS-fine needle aspiration (FNA) in evaluating mediastinal lymphadenopathy.
METHODS:Only EUS and EUS-FNA studies confirmed by surgery or with appropriate follow-up were selected. Articles were searched in Medline, Pubmed, and Cochrane control trial registry. Only studies from which a 2 × 2 table could be constructed for true positive, false negative, false positive and true negative values were included. Two reviewers independently searched and extracted data. The differences were resolved by mutual agreement. Meta-analysis for the accuracy of EUS was analyzed by calculating pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. Pooling was conducted by both Mantel-Haenszel method (fixed effects model) and DerSimonian Laird method (random effects model). The heterogeneity of studies was tested using Cochran's Q test based upon inverse variance weights.
RESULTS:Data was extracted from 76 studies (n = 9310) which met the inclusion criteria. Of these, 44 studies used EUS alone and 32 studies used EUS-FNA. FNA improved the sensitivity of EUS from 84.7% (95% CI:82.9-86.4) to 88.0% (95% CI:85.8-90.0). With FNA, the specificity of EUS improved from 84.6% (95% CI:83.2-85.9) to 96.4% (95% CI:95.3-97.4). The P forchi-squared heterogeneity for all the pooled accuracy estimates was 〉 0.10.
CONCLUSION:EUS is highly sensitive and specific for the evaluation of mediastinal lymphadenopathy and FNA substantially improves this. EUS with FNA should be the diagnostic test of choice for evaluating mediastinal lymphadenopathy. 相似文献
METHODS:Only EUS and EUS-FNA studies confirmed by surgery or with appropriate follow-up were selected. Articles were searched in Medline, Pubmed, and Cochrane control trial registry. Only studies from which a 2 × 2 table could be constructed for true positive, false negative, false positive and true negative values were included. Two reviewers independently searched and extracted data. The differences were resolved by mutual agreement. Meta-analysis for the accuracy of EUS was analyzed by calculating pooled estimates of sensitivity, specificity, likelihood ratios, and diagnostic odds ratios. Pooling was conducted by both Mantel-Haenszel method (fixed effects model) and DerSimonian Laird method (random effects model). The heterogeneity of studies was tested using Cochran's Q test based upon inverse variance weights.
RESULTS:Data was extracted from 76 studies (n = 9310) which met the inclusion criteria. Of these, 44 studies used EUS alone and 32 studies used EUS-FNA. FNA improved the sensitivity of EUS from 84.7% (95% CI:82.9-86.4) to 88.0% (95% CI:85.8-90.0). With FNA, the specificity of EUS improved from 84.6% (95% CI:83.2-85.9) to 96.4% (95% CI:95.3-97.4). The P forchi-squared heterogeneity for all the pooled accuracy estimates was 〉 0.10.
CONCLUSION:EUS is highly sensitive and specific for the evaluation of mediastinal lymphadenopathy and FNA substantially improves this. EUS with FNA should be the diagnostic test of choice for evaluating mediastinal lymphadenopathy. 相似文献
94.
Jyotsna A. Patil Arun J. Patil Ajit V. Sontakke Sanjay P. Govindwar 《Indian journal of pharmacology》2008,40(4):158-163
Objective:
To study the effect of the methomyl on mixed function oxidase system in rats.Materials and Methods:
The effect of the methomyl on mixed function oxidase was studied using different dosages, durations and sex. Microsomes were isolated using the calcium precipitation method. The levels of cytochrome P450 , and cytochrome b5 were determined using extinction coefficient of 91 and 85 mM-1 respectively. The activities of drug metabolizing enzymes, hemoglobin content, liver function enzymes, and serum cholinesterase activity were assayed by using standard methods.Results:
Intraperitoneal administration of methomyl (4 mg/kg body weight) showed significant decrease in the level of cytochrome P450 , and the activities of aminopyrine N-demethylase and aniline hydroxylase on the third day of the treatment. Methomyl (4 mg/kg) treatment of old male rat and adult female rat also showed a decrease in the level of cytochrome P450 , and aminopyrine N-demethylase activity. The serum samples from methomyl treated rats (male and female), when analyzed for alanine aminotransferase (SGPT) and aspartate aminotransferase (SGOT) as markers of the liver toxicity, showed significant increase in the activity. The activities of SGPT and SGOT were significantly higher in the treated rats (2 and 4 mg/kg) than in the control group. A significant decrease in the level of hemoglobin and serum cholinesterase activity was observed, when there was an increase in the dose level. A significant increase was observed in alkaline phosphatase activity at all dose levels.Conclusion:
Methomyl influences mixed function oxidase and creates abnormality of liver functions in the rats. This effect depends on the dose and duration of methomyl. 相似文献95.
96.
Recent advances in particle-forming chemistries used for developing nanotechnology has not only widened novel applications for nanoscale materials but also has provided significant concern regarding their biological effects. The present study investigates the inflammatory responses of RAW 264.7 mouse macrophages exposed to nanoparticles (NPs, 5 μg/ml) of varied sizes including silver (Ag), aluminum (Al), carbon black (CB), carbon-coated silver (CAg) and gold (Au). A significant increase in IL-6, reactive oxygen species (ROS) generation, nuclear translocation of nuclear factor-kappa B (NF-κB), induction of cyclooxygenase-2 (COX-2), and tumor necrosis factor-alpha (TNF-α) expression was observed in macrophages with maximum response found in cells exposed to Ag NPs followed by Al, CB and CAg. These pro-inflammatory effects of NPs were dependent on size and duration of exposure and comparable to those induced by lipopolysaccharide (LPS), a known inflammatory mediator. Au NPs, on the other hand, induced small but significant inflammatory responses in macrophages upon prolonged exposure. These studies reveal that Ag NPs exhibit higher propensity in inducing inflammation, mediated by ROS and NF-κB signaling pathways and leading to the induction of COX-2, TNF-α and IL-6. However, no such prominent pro-inflammatory responses were observed with Au NPs, suggesting their bio-compatibility. 相似文献
97.
Introduction and Objective
Numerous methods have been described for achievement of Intermaxillary fixation in the treatment of fractures of facial skeleton. Conventional methods like Erich arch bars and eyelet wires are currently most common methods for achieving intermaxillary fixation (IMF), but they have their own disadvantages. Since 1989, IMF using intraoral self tapping IMF screws has been introduced for treatment of mandibular fractures. The aim of this work was to compare the efficacy, advantages, disadvantages indications and potential complications associated with Erich archbar v/s self tapping IMF screws in the management of mandibular fractures. 相似文献98.
Conti V Marini C Gana S Sudi J Dobyns WB Guerrini R 《American journal of medical genetics. Part A》2011,155(4):892-897
We report on a patient with agenesis of the corpus callosum (ACC), severe mental retardation, infantile spasms and subsequent intractable epilepsy, spastic/dyskinetic quadriparesis, severe limb contractures, and scoliosis. This complex, newly described phenotype, is due to a novel non-conservative missense mutation in the ARX homeodomain (c.1072A>T; p.R358W), inherited from the unaffected mother. Differently from previously reported non-conservative mutations falling within the same domain, p.R358W did not cause XLAG. It is therefore possible that differences in clinical manifestations between our patient and those with XLAG, are related to the different position of the amino acid substitution in the homeodomain, or to the different chemical properties introduced by the substitution itself. To test the hypothesis that the patient's mother was asymptomatic because of non-random X chromosome inactivation (XCI), we performed DNA methylation studies of the human androgen receptor gene, demonstrating skewing of the XCI ratio (85:15). The complex phenotype described here combines different traits that had previously been linked to various ARX mutations, including conservative missense mutations in the homeodomain and expansion in the first ARX polyalanine tract and contributes to the expanding pleiotropy associated with ARX mutations. 相似文献
99.
100.