全文获取类型
收费全文 | 471篇 |
免费 | 30篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 4篇 |
妇产科学 | 17篇 |
基础医学 | 56篇 |
口腔科学 | 26篇 |
临床医学 | 32篇 |
内科学 | 88篇 |
皮肤病学 | 23篇 |
神经病学 | 43篇 |
特种医学 | 20篇 |
外科学 | 91篇 |
综合类 | 12篇 |
预防医学 | 35篇 |
眼科学 | 11篇 |
药学 | 23篇 |
中国医学 | 1篇 |
肿瘤学 | 15篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 16篇 |
2021年 | 22篇 |
2020年 | 17篇 |
2019年 | 19篇 |
2018年 | 20篇 |
2017年 | 16篇 |
2016年 | 24篇 |
2015年 | 20篇 |
2014年 | 27篇 |
2013年 | 24篇 |
2012年 | 38篇 |
2011年 | 35篇 |
2010年 | 22篇 |
2009年 | 14篇 |
2008年 | 49篇 |
2007年 | 40篇 |
2006年 | 21篇 |
2005年 | 8篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 5篇 |
2000年 | 9篇 |
1999年 | 2篇 |
1998年 | 1篇 |
1997年 | 2篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1992年 | 4篇 |
1991年 | 5篇 |
1990年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1976年 | 1篇 |
1959年 | 1篇 |
排序方式: 共有503条查询结果,搜索用时 15 毫秒
31.
32.
Polymerizable cyclodextrin derivatives (PCDs) have been proposed as candidates for use in dental therapeutics (Bowen, 1996; Bowen and Reed, 1997). Here, PCD "libraries" were synthesized by quasi-random reactions of 6 moles of methacrylic anhydride plus 6 moles of cyclic glutaric anhydride per mole of beta-cyclodextrin (BCD) in solution. BCD has 21 reactive sites on each of its molecules. These proportions were based on probability calculations, which predicted that the products should have a minimum of 2 polymerizable substituents and acidic ligand groups on practically every one of the diverse product molecules. Matrix-assisted laser desorption/ionization (MALDI) time of flight (TOF) mass spectrometry (MS) gave valuable information regarding the masses of molecular ions representing the molecules that made up the PCD libraries. For the MALDI-TOF MS analyses, small samples were analyzed by the successive application of 3 solutions to the sample holder: the matrix in acetone, the products in water, and sodium trifluoroacetate in water. The resulting spectra had > 40 envelopes of mass peaks above background. The ionic-abundance peak heights had quasi-Gaussian configurations, with central peaks having masses in the neighborhood of 2000 g/mol (Daltons). Regardless of structural permutations within each peak, the range of these peaks was between about 1500 g/mol and 2900 g/mol. This range of masses was in accord with, but perhaps somewhat more narrow than, that predicted by the statistical method, which was based on equal reactivity of all hydroxyl groups. Analysis by MALDI-TOF MS gave valuable data regarding the masses, structures, and characteristics of the products formed and provided unanticipated information to facilitate improvements in future PCD syntheses. 相似文献
33.
Seyed Mahdi Sadat-Hashemi Raheb Ghorbani Hesamodin Askari Majdabadi Farideh Khalajabadi Farahani 《The European journal of contraception & reproductive health care》2007,12(2):148-153
OBJECTIVES: In spite of the government's efforts, the prevalence of contraceptive use in Iran is only 55.4%. Health concerns, side effects, failure of the methods and some demographic issues, among which education, age, and number of daughters, have a great influence on the enforcement of contraceptive measures. The aim of the present study was to identify factors affecting contraceptive use in Iran. METHODS: Data from the project 'The study of contraceptive practice in Tehran, 1999-2000' were analyzed with regard to the factors associated with contraceptive use by Iranian couples. A total of 4042 women at reproductive ages who had delivered in one of the 12 teaching hospitals of Tehran and had at least one child that lived for at least 24 hours after birth, were interviewed using a questionnaire that gathered information about their socio-demographic status, fertility history, and other characteristics. RESULTS: Using a multinomial logistic regression, it was found that the woman's age, her own or her husband's level of education, previous awareness about contraceptive methods, number of abortions, and number of sons and daughters were factors that were significantly associated with contraceptive use. CONCLUSIONS: A number of factors affect the application of contraceptive measures. It is essential that health policy makers be aware of these to promote contraception and population control. 相似文献
34.
Afsar T. Ozkut Yusuf Iyetin Omer K. Unal M. Salih Soylemez Esat Uygur Irfan Esenkaya 《Acta orthopaedica et traumatologica turcica》2018,52(2):81-86
Objective
To evaluate the midterm clinical and radiological outcomes of the medial approach using two intervals for developmental hip dysplasia (DDH).Methods
The study involved 62 hips of 47 patients (41 girls, 6 boys) treated with medial approach for DDH from 1999 to 2010. The age of the patients at surgery was 18.7 ± 2.25 months. Follow up of the patients was 11.3 ± 3.07 years. The age of the patients at the last follow up was 12.6 ± 1.74 years. According to the Tönnis classification, 13 hips were grade II, 27 hips were grade III and 22 hips were grade IV. Patients were evaluated according to Omeroglu radiological criteria and modified McKay functional criteria. The presence of avascular necrosis (AVN) of the hip was questioned using the KalamchiMacEwen classification.Results
Radiologically, forty eight (77%) hips were evaluated as “excellent”, 8 (13%) hips as “good” and 5 (8%) hips as “fair plus” and 1 (%2) hip as “fair minus”. Two (3%) patients had type 1 temporary AVN and one (1%) patient had type 4 AVN with coxa magna and overgrowth of the greater trochanter. According to McKay functional criteria, 56 (90%) hips had “excellent” and 6 (10%) had “good” results. Two (3.2%) hips of one patient had to be reoperated with Salter osteotomy and femoral shortening + derotation osteotomy.Conclusion
Medial approach using two separate intervals for tenotomy and capsulotomy does not jeopardize the medial circumflex or the femoral vessels and yields satisfactory midterm results for children 18 months old with dysplasia of the hip.Level of evidence
Level IV, therapeutic study. 相似文献35.
Baris Afsar Dimitrie Siriopol Gamze Aslan Ozgur C. Eren Tuncay Dagel Ugur Kilic Asiye Kanbay Alexandru Burlacu Adrian Covic Mehmet Kanbay 《International urology and nephrology》2018,50(5):885-904
The prevalence of chronic kidney disease (CKD) and end-stage renal disease (ESRD) is increasing steadily. CKD does not only relate to morbidity and mortality but also has impact on quality of life, depression and malnutrition. Such patients often have significantly decreased physical activity. Recent evidence suggests that low physical activity is associated with morbidity, mortality, muscle atrophy, quality of life impairment, cardiovascular outcomes and depression. Based on this, it is now recommended to regularly improve the physical activity of these patients. Furthermore, studies have shown the beneficial effects of various exercise programs with respect to outcomes such as low physical activity muscle atrophy, quality of life, cardiovascular outcomes and depression. Despite these encouraging findings, the subject is still under debate, with various aspects still unknown. In this review, we tried to critically summarize the existing studies, to explore mechanisms and describe future perspectives regarding physical activity in CKD/ESRD patients. 相似文献
36.
Sarwat Jahan Asma Munawar Suhail Razak Sara Anam Qurat Ul Ain Hizb Ullah Tayyaba Afsar Mahmoud Abulmeaty Ali Almajwal 《BMC urology》2018,18(1):107
Background
Cisplatin (CP) or cis-diammine dichloroplatinum (II) is a platinum based standard antineoplastic drug which is used against variety of solid tumors and neoplasms. The present study aimed to evaluate the shielding effects of rutin against CP induced testicular toxicity in rats.Methods
28 male rats were divided into four groups. First group was given saline orally while second group received intra-peritoneal (i.p) injection of cisplatin (7 mg/kg) on day first and received saline for next 13 days. Third group received i.p injection of cisplatin at day one and treated with rutin (75 mg/kg) orally for next 13 days. Fourth group was treated with rutin orally for 13 days. Animals were sacrificed on 14th day and reproductive organs were analyzed for various parameters.Results
Cisplatin treatment resulted in a significant decrease in daily sperm production, decrease in head length and % DNA in head, reduction of epithelial cell height, tubular diameter, reduction of the number of spermatogonia, spermatocytes and spermatids, increase in the thiobarbituric acid reactive substances (TBARS) and oxidative stress in testicular tissues, and change of the intra-testicular testosterone concentrations. Rutin co-treatment resulted in reversing cisplatin effect on DNA damage, sperm count, histological and biochemical parameters.Conclusion
These results indicated that rutin co-treatment could ameliorate cisplatin-induced reproductive toxicity in male rats.37.
38.
Kadriye Agan Nazire Afsar Ipek Midi Onder Us Sevinc Aktan Canan Aykut-Bingol 《Epilepsy & behavior : E&B》2009,14(4):651-654
Refractory status epilepticus (RSE) is known to constitute approximately 10–50% of all cases of status epilepticus (SE) and is associated with significant morbidity and mortality. In the present study, data from a prospectively collected SE database were analyzed. Patients with RSE (defined as a SE episode requiring a second line of intravenous treatment following intravenous phenytoin) were compared with patients with nonrefractory SE (NRSE); 290 episodes of SE were identified, of which 108 (38%) were defined as RSE. Univariate analysis revealed that age, female gender, SE type, SE duration, and acute etiology were associated with refractoriness, whereas electroencephalographic patterns were not. Nonconvulsive SE, which is probably associated with delays in treatment initiation, was a predictor of RSE, although it was not retained as a predictor in multivariate analysis. In the latter analysis, female gender (odds ratio: 1.815, 95% CI: 1.053–3.126) and acute etiology (odds ratio: 0.619, 95% CI: 0.429–0.894) were shown to be the only significant independent predictors of refractoriness. 相似文献
39.
40.
Qiu H Strååt K Rahbar A Wan M Söderberg-Nauclér C Haeggström JZ 《The Journal of experimental medicine》2008,205(1):19-24
Leukotrienes (LTs) are powerful proinflammatory lipid mediators that may play a central role in cardiovascular diseases, including arteriosclerosis, myocardial infarction, and stroke. Owing to restricted expression of 5-lipoxygenase (5-LO), the enzyme required for their synthesis, LTs are almost exclusively produced by myeloid cells. Here, we report that human cytomegalovirus (HCMV) infection of human vascular smooth muscle cells (SMCs) increases 5-LO mRNA levels by up to 170-fold in a dose- and time-dependent manner. Infected cells expressed 5-LO protein, as shown by immunohistochemistry, enabling them to synthesize bioactive LTB(4). HCMV-infected vascular SMCs expressing 5-LO protein were readily detected in tissue samples from CMV-infected patients with inflammatory bowel disease or AIDS. Thus, pathogen-induced LT production in HCMV-infected tissues may contribute to local inflammation, consistent with the ability of HCMV to control cellular and immunological functions. HCMV-induced LT biosynthesis in SMCs offers a molecular mechanism to explain HCMV-induced pathogenesis in inflammatory diseases. 相似文献