全文获取类型
收费全文 | 8094篇 |
免费 | 490篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 93篇 |
儿科学 | 262篇 |
妇产科学 | 151篇 |
基础医学 | 1358篇 |
口腔科学 | 454篇 |
临床医学 | 609篇 |
内科学 | 1734篇 |
皮肤病学 | 211篇 |
神经病学 | 796篇 |
特种医学 | 101篇 |
外科学 | 819篇 |
综合类 | 33篇 |
一般理论 | 5篇 |
预防医学 | 728篇 |
眼科学 | 153篇 |
药学 | 555篇 |
中国医学 | 50篇 |
肿瘤学 | 519篇 |
出版年
2024年 | 7篇 |
2023年 | 66篇 |
2022年 | 185篇 |
2021年 | 311篇 |
2020年 | 193篇 |
2019年 | 243篇 |
2018年 | 310篇 |
2017年 | 190篇 |
2016年 | 234篇 |
2015年 | 237篇 |
2014年 | 372篇 |
2013年 | 483篇 |
2012年 | 708篇 |
2011年 | 739篇 |
2010年 | 392篇 |
2009年 | 315篇 |
2008年 | 606篇 |
2007年 | 538篇 |
2006年 | 504篇 |
2005年 | 420篇 |
2004年 | 405篇 |
2003年 | 382篇 |
2002年 | 334篇 |
2001年 | 33篇 |
2000年 | 35篇 |
1999年 | 39篇 |
1998年 | 54篇 |
1997年 | 33篇 |
1996年 | 29篇 |
1995年 | 27篇 |
1994年 | 25篇 |
1993年 | 19篇 |
1992年 | 10篇 |
1991年 | 12篇 |
1990年 | 11篇 |
1989年 | 14篇 |
1988年 | 16篇 |
1987年 | 11篇 |
1986年 | 10篇 |
1985年 | 8篇 |
1984年 | 14篇 |
1983年 | 4篇 |
1982年 | 11篇 |
1981年 | 6篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1972年 | 2篇 |
1970年 | 2篇 |
排序方式: 共有8631条查询结果,搜索用时 15 毫秒
61.
Natalia Carrillo-Lpez Sara Panizo Maria Vittoria Arcidiacono Sandra de la Fuente Laura Martínez-Arias Emerenziana Ottaviano Catalina Ulloa María Piedad Ruiz-Torres Isabel Rodríguez Jorge B. Cannata-Andía Manuel Naves-Díaz Adriana S. Dusso 《Nutrients》2022,14(13)
In chronic kidney disease, systemic inflammation and high serum phosphate (P) promote the de-differentiation of vascular smooth muscle cells (VSMC) to osteoblast-like cells, increasing the propensity for medial calcification and cardiovascular mortality. Vascular microRNA-145 (miR-145) content is essential to maintain VSMC contractile phenotype. Because vitamin D induces aortic miR-145, uremia and high serum P reduce it and miR-145 directly targets osteogenic osterix in osteoblasts, this study evaluated a potential causal link between vascular miR-145 reductions and osterix-driven osteogenic differentiation and its counter-regulation by vitamin D. Studies in aortic rings from normal rats and in the rat aortic VSMC line A7r5 exposed to calcifying conditions corroborated that miR-145 reductions were associated with decreases in contractile markers and increases in osteogenic differentiation and calcium (Ca) deposition. Furthermore, miR-145 silencing enhanced Ca deposition in A7r5 cells exposed to calcifying conditions, while miR-145 overexpression attenuated it, partly through increasing α-actin levels and reducing osterix-driven osteogenic differentiation. In mice, 14 weeks after the induction of renal mass reduction, both aortic miR-145 and α-actin mRNA decreased by 80% without significant elevations in osterix or Ca deposition. Vitamin D treatment from week 8 to 14 fully prevented the reductions in aortic miR-145 and attenuated by 50% the decreases in α-actin, despite uremia-induced hyperphosphatemia. In conclusion, vitamin D was able to prevent the reductions in aortic miR-145 and α-actin content induced by uremia, reducing the alterations in vascular contractility and osteogenic differentiation despite hyperphosphatemia. 相似文献
62.
Ulrich Hegerl Roland Mergl Christian Sander Jens Dietzel Istvan Bitter Koen Demyttenaere Ricardo Gusmão Ana González-Pinto Iñaki Zorrilla Adriana García Alocén Victor Perez Sola Eduard Vieta Georg Juckel Ulrich S. Zimmermann Michael Bauer Pascal Sienaert Sónia Quintão Marc-Andreas Edel Michael Kluge 《European neuropsychopharmacology》2018,28(1):185-194
Based on many clinical and preclinical findings the ‘vigilance regulation model of mania’ postulates that an unstable regulation of wakefulness is a pathogenetic factor in both mania and Attention Deficit Hyperactivity Disorder (ADHD) and induces hyperactivity and sensation seeking as an autoregulatory attempt to stabilize wakefulness. Accordingly, stimulant medications with their vigilance stabilizing properties could have rapid antimanic effects similar to their beneficial effects in ADHD. The MEMAP study – a multi-center, double-blind, placebo-controlled and randomized clinical trial (RCT) – assessed the antimanic efficacy and safety of a 2.5-day treatment with methylphenidate (20–40 mg/day). Of 157 screened patients with acute mania, 42 were randomly assigned to receive 20–40 mg per day of methylphenidate in one or two applications, or placebo. The primary outcome was the change in Young Mania Rating Scale (YMRS) sum scores from baseline to day 2.5 in the methylphenidate group compared to the placebo group. A group sequential design was chosen to justify early RCT termination based on efficacy or futility at an interim analysis after inclusion of 40 patients. In the interim analysis, the change from baseline in the YMRS total score at day 2.5 was not significantly different between both groups (F(1,37)=0.23; p=0.64). Thus, futility was declared for methylphenidate and the RCT was stopped. In summary, although methylphenidate was well tolerated and safe in the full analysis set, it failed to show efficacy in the treatment of acute mania. Trial registration: clinicaltrials.gov (URL: http://www.clinicaltrials.gov; registration number: NCT01541605). 相似文献
63.
Marian Novac Adina Magdalena Musuc Emma Adriana Ozon Iulian Sarbu Mirela Adriana Mitu Adriana Rusu Simona Petrescu Irina Atkinson Daniela Gheorghe Dumitru Lupuliasa 《Materials》2022,15(15)
The development of new orally dispersible tablets containing amlodipine (AML) inclusion complexes in hydroxypropyl-β-cyclodextrin (HP-β-CD) and in methyl-β-cyclodextrin (Me-β-CD) was studied. The methods of obtaining amlodipine and the physical and chemical properties of the inclusion complexes using the two cyclodextrins was investigated separately. Solid inclusion complexes were obtained by three methods: kneading, coprecipitation, and lyophilization, at a molar ratio of 1:1. For comparison, a physical mixture in the same molar ratio was prepared. The aim of the complexation process was to improve the drug solubility. As the lyophilization method leads to a complete inclusion of the drug in the guest molecule cavity, for both used cyclodextrins, these types of compounds were selected as active ingredients for the design of orally dispersible tablets. Subsequently, the formulation of the orodispersible tablets containing AML-HP-β-CD and AML-Me-β-CD inclusion complexes and quality parameters of the final formulation were evaluated. The results prove that F1 and F4 formulations, based on silicified microcrystalline cellulose, which contains insignificant proportions of very small or very large particles, had the lowest moisture degree (3.52% for F1 and 4.03% for F4). All of these demonstrate their porous structure, which led to good flowability and compressibility performances. F1 and F4 formulations were found to be better to manufacture orally dispersible tablets. 相似文献
64.
Adina Frum Carmen Maximiliana Dobrea Luca Liviu Rus Lidia-Ioana Virchea Claudiu Morgovan Adriana Aurelia Chis Anca Maria Arseniu Anca Butuca Felicia Gabriela Gligor Laura Gratiela Vicas Ovidiu Tita Cecilia Georgescu 《Nutrients》2022,14(15)
Grape pomace and berries represent natural sources of phytochemicals that can increase the quality of life of consumers by contributing to the prevention of chronic diseases; thus, the development of a dietary supplement was necessary. The raw material (r.m.) used for the development of the dietary supplement consisted of dried and powdered bilberries (Vaccinium myrtillus L.), red currants (Ribes rubrum L.), and red fermented pomaces (Vitis vinifera L.) from Feteasca Neagra and Cabernet Sauvignon cultivars. The particle size distribution, powder flow, total phenolic content (TPC), HPLC-DAD phenolic profile assessment, and radical scavenging assay (RSA) were employed for the analysis of the raw material. After encapsulation, the average mass and uniformity of mass, the disintegration, and the uniformity of content for the obtained capsules were performed to obtain a high-quality dietary supplement. All the assays performed complied to the compendial requirements and the TPC was determined at 9.07 ± 0.25 mg gallic acid equivalents/g r.m. and RSA at 48.32 ± 0.74%. The highest quantities of phenolic compounds determined were 333.7 ± 0.50 µg/g r.m. for chlorogenic acid, followed by rutin, ferulic acid, and (+)-catechin with 198.9 ± 1.60 µg/g r.m., 179.8 ± 0.90 µg/g r.m. and 118.7 ± 0.75 µg/g r.m., respectively. The results of this study can be used for the manufacturing and assessing of pilot scale-up capsule batches and thinking of quality assurance, we recommend that the industrial batch extracts should be standardized in polyphenols, and the manufacturing process should be validated. 相似文献
65.
66.
Ferrandina G Martinelli E Petrillo M Prisco MG Zucconi A Santaguida S Zannoni G Scambia G Ferlini C 《Gynecologic oncology》2008,111(2):237-243
ObjectiveThe aim of the study was to investigate the potential clinical relevance of immunohistochemically assessed RON expression in a large, single institution series of primary untreated advanced ovarian cancer patients.MethodsImmunohistochemical analysis was performed by using the polyclonal rabbit anti-RON-β antibody (C-20, clone sc-322, Santa Cruz, California). Results were expressed as the total proportion of immunostained tumor cells (RON positivity), or the percentage of cells showing strong staining of RON expression (H-RON positivity).ResultsIn the overall series RON positive immunoreaction was observed in 103/141 cases, while H-Ron positivity was detected in 577141 (40.4%) cases. No association between RON and H-RON expression with response to first-line treatment was documented. During the follow up period, progression and death of disease were observed in 111 (78.7%) and 76 (53.9%) cases, respectively. Cases with strong H-RON expression has a shorter overall survival (median = 35 months) than cases with low RON levels (median = 59 months) (X2 = ? 2.1, p value = 0.032). In multivariate analysis, only platinum resistance, and extent of residual tumor retained an independent negative prognostic role for OS, with the percentages of H-RON positively immunostained cells showing a borderline statistical significance (p value = 0.0643). The unfavourable role of elevated percentages of H-RON expression was maintained only in the subgroup of platinum resistant recurrent ovarian cancer patients (X2 = 3.89, p value = 0.048) compared to the platinum sensitive ones (X2 = 1.98, p value = 0.16).ConclusionsThe assessment of RON expression deserves further attention as a parameter helpful to identify poor prognosis ovarian cancer patients potentially candidates to investigational agents. 相似文献
67.
68.
Arama V Vladareanu R Mihailescu R Streinu Cercel A Mihai C Hristea A Iosipenco M Arama SS Rabilloud M 《Journal of perinatal medicine》2008,36(3):206-212
OBJECTIVES: To estimate the type-specific seroprevalence and identify the risk factors associated with herpes simplex virus (HSV)-2 infection in pregnant women in Bucharest, Romania. METHODS: A prospective survey was conducted in 452 subjects, aged 15-39 years, at the Elias Hospital, during the years 2004-2005. We evaluated serum IgG anti-bodies to HSV-1 and HSV-2 using the HerpeSelect ELISA test. All subjects completed an epidemiological questionnaire. RESULTS: Seroprevalence was 87.3% and 15.1% for HSV-1 and HSV-2, respectively. The risk factors for HSV-2 infection were lower level of education and a greater number of sexual partners. Elementary school and high-school graduates were 6.28 and 2.26 times more exposed than University graduates. Having 2-3 partners and more than three partners was associated with 2.43 and 4.26 times the risk of acquiring HSV-2, compared with having one partner. CONCLUSIONS: In pregnant women, HSV-1 seroprevalence was higher than in Western Europe but similar to that in Eastern Europe. HSV-2 seroprevalence was within European ranges. Both were lower than in the USA. Risk factors for HSV-2 infection may lead to prevention programs. 相似文献
69.
BACKGROUND: Extraosseous chondromas are cartilaginous tissue tumors with a nodular appearance on the hands and feet. There are reports of these tumors occurring on the knee, neck, back, liver and testis and in the oral cavity. Occurrence in the pelvis is generally rare. The origin is metaplastic and may be mesenchymal or subcelomic. Treatment is by surgery and requires removing the tumor with a safety margin. Recurrences are infrequent, and distant metastasis has never been reported. CASE: An 11-year-old girl was referred for a painless solid tumor located on the mons pubis. Surgical removal of the tumor with a safety margin was performed. Macroscopically, the tumor was shiny when cut open and yellowish. Microscopic examination revealed a very distinct cartilage-forming tumor compatible with extraosseous chondroma. Two years after the operation, the patient had no recurrence. CONCLUSION: Extraosseous chondroma is a rare benign tumor. Finding it in children is even less frequent, and localization in the vulvar region has never before been reported. This appears to be the first such report of this type of tumor in this region and age range. 相似文献
70.
Efficacy of barriers and hypoxia-inducible factor inhibitors to prevent CO(2) pneumoperitoneum-enhanced adhesions in a laparoscopic mouse model 总被引:1,自引:0,他引:1
Binda MM Molinas CR Bastidas A Jansen M Koninckx PR 《Journal of minimally invasive gynecology》2007,14(5):591-599
STUDY OBJECTIVE: To investigate the effects of hypoxia-inducible factor (HIF) inhibitors, flotation agents, barriers, and a surfactant on pneumoperitoneum-enhanced adhesions in a laparoscopic mouse model. DESIGN: Prospective randomized trial (Canadian Task Force classification I). SETTING: Department of Obstetrics and Gynecology, University Hospital Gasthuisberg, Catholic University of Leuven. SUBJECTS: One hundred fourteen female BALB/c mice. INTERVENTIONS: Adhesions were induced during laparoscopy in BALB/c female mice. Pneumoperitoneum was maintained for 60 minutes with humidified CO(2). In 3 experiments the effects of HIF inhibitors such as 17-allylamino 17-demethoxygeldanamycin, radicicol, rapamycin, and wortmanin, flotation agents such as Hyskon and carboxymethylcellulose, barriers such as Hyalobarrier gel and SprayGel, and surfactant such as phospholipids were evaluated. MEASUREMENTS AND MAIN RESULTS: Adhesions were scored after 7 days during laparotomy. Adhesion formation decreased with the administration of wortmannin (p <.01), phospholipids (p <.01), Hyalobarrier Gel (p <.01), and SprayGel (p <.01). CONCLUSIONS: These experiments confirm the efficacy of barriers and phospholipids to separate or lubricate damaged surfaces. They also confirm the role of mesothelial hypoxia in this model by the efficacy of the HIF inhibitor wortmannin. 相似文献