全文获取类型
收费全文 | 6756篇 |
免费 | 443篇 |
国内免费 | 71篇 |
专业分类
耳鼻咽喉 | 50篇 |
儿科学 | 198篇 |
妇产科学 | 175篇 |
基础医学 | 960篇 |
口腔科学 | 276篇 |
临床医学 | 548篇 |
内科学 | 1845篇 |
皮肤病学 | 172篇 |
神经病学 | 670篇 |
特种医学 | 158篇 |
外科学 | 581篇 |
综合类 | 11篇 |
一般理论 | 1篇 |
预防医学 | 345篇 |
眼科学 | 53篇 |
药学 | 437篇 |
中国医学 | 5篇 |
肿瘤学 | 785篇 |
出版年
2024年 | 12篇 |
2023年 | 64篇 |
2022年 | 170篇 |
2021年 | 224篇 |
2020年 | 148篇 |
2019年 | 175篇 |
2018年 | 215篇 |
2017年 | 158篇 |
2016年 | 180篇 |
2015年 | 206篇 |
2014年 | 304篇 |
2013年 | 373篇 |
2012年 | 557篇 |
2011年 | 509篇 |
2010年 | 294篇 |
2009年 | 260篇 |
2008年 | 480篇 |
2007年 | 456篇 |
2006年 | 435篇 |
2005年 | 420篇 |
2004年 | 355篇 |
2003年 | 350篇 |
2002年 | 346篇 |
2001年 | 41篇 |
2000年 | 24篇 |
1999年 | 43篇 |
1998年 | 64篇 |
1997年 | 54篇 |
1996年 | 45篇 |
1995年 | 42篇 |
1994年 | 33篇 |
1993年 | 20篇 |
1992年 | 30篇 |
1991年 | 19篇 |
1990年 | 23篇 |
1989年 | 12篇 |
1988年 | 15篇 |
1987年 | 8篇 |
1986年 | 18篇 |
1985年 | 9篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 6篇 |
1975年 | 3篇 |
1974年 | 3篇 |
1972年 | 4篇 |
1971年 | 4篇 |
1970年 | 3篇 |
排序方式: 共有7270条查询结果,搜索用时 468 毫秒
71.
Caccamo C Nostro L Giorgianni G Mondello S Crascì E Frisina N Buemi M 《The Journal of reproductive medicine》2007,52(11):1035-1039
OBJECTIVE: To evaluate any correlations between erythropoietin (EPO) and vascular endothelial growth factor (VEGF) levels in the serum and the menstrual fluid of healthy women during the different phases of the menstrual cycle. STUDY DESIGN: Blood samples from 25 healthy female volunteers were obtained for serum VEGF and EPO detection on the 1st, 7th, 14th, 21st and 25th days of the menstrual cycle. Menstrual fluid samples for VEGF and EPO detection were obtained on the 1st and 4th days of menstruation. RESULTS: Circulating VEGF levels were found to increase in a stage-dependent cyclic manner. The mean VEGF concentration in menstrual blood on the 1st day of the cycle was significantly higher than the mean plasma value and was reduced to a significant extent on the 4th day of the cycle. We found no significant changes in serum EPO levels. Mean EPO concentration detected in menstrual blood was comparable to those in serum blood either on the 1st or 4th day of the menstrual cycle. CONCLUSION: During menstruation, a local production of VEGF occurs independent of systemic production, thus sustaining angiogenic activity in autonomous, independent ways. Our findings demonstrate the presence of an "open compartment" that reflects the systemic pattern of EPO at the uterine level that allows us to speculate on different effects beyond the angiogenic action of EPO. 相似文献
72.
Raul Zamora-Ros Valerie Cayssials Mazda Jenab Joseph A. Rothwell Veronika Fedirko Krasimira Aleksandrova Anne Tjønneland Cecilie Kyrø Kim Overvad Marie-Christine Boutron-Ruault Franck Carbonnel Yahya Mahamat-Saleh Rudolf Kaaks Tilman Kühn Heiner Boeing Antonia Trichopoulou Elissavet Valanou Effie Vasilopoulou Giovanna Masala Valeria Pala Salvatore Panico Rosario Tumino Fulvio Ricceri Elisabete Weiderpass Torkjel M. Sandanger Cristina Lasheras Antonio Agudo Maria-Jose Sánchez Pilar Amiano Carmen Navarro Eva Ardanaz Emily Sonestedt Bodil Ohlsson Lena Maria Nilsson Martin Rutegård Bas Bueno-de-Mesquita Kay-Thee Khaw Nicholas J. Wareham Kathryn Bradbury Heinz Freisling Isabelle Romieu Amanda J. Cross Paolo Vineis Augustin Scalbert 《European journal of epidemiology》2018,33(11):1063-1075
Polyphenols may play a chemopreventive role in colorectal cancer (CRC); however, epidemiological evidence supporting a role for intake of individual polyphenol classes, other than flavonoids is insufficient. We evaluated the association between dietary intakes of total and individual classes and subclasses of polyphenols and CRC risk and its main subsites, colon and rectum, within the European Prospective Investigation into Cancer and Nutrition (EPIC) study. The cohort included 476,160 men and women from 10 European countries. During a mean follow-up of 14 years, there were 5991 incident CRC cases, of which 3897 were in the colon and 2094 were in the rectum. Polyphenol intake was estimated using validated centre/country specific dietary questionnaires and the Phenol-Explorer database. In multivariable-adjusted Cox regression models, a doubling in total dietary polyphenol intake was not associated with CRC risk in women (HRlog2?=?1.06, 95% CI 0.99–1.14) or in men (HRlog2?=?0.97, 95% CI 0.90–1.05), respectively. Phenolic acid intake, highly correlated with coffee consumption, was inversely associated with colon cancer in men (HRlog2?=?0.91, 95% CI 0.85–0.97) and positively associated with rectal cancer in women (HRlog2?=?1.10, 95% CI 1.02–1.19); although associations did not exceed the Bonferroni threshold for significance. Intake of other polyphenol classes was not related to colorectal, colon or rectal cancer risks. Our study suggests a possible inverse association between phenolic acid intake and colon cancer risk in men and positive with rectal cancer risk in women. 相似文献
73.
Maria Giovanna Cilberti Antonella Santillo Anna N. Polito Giovanni Messina Antonella della Malva Mariangela Caroprese Agostino Sevi Marzia Albenzio 《Nutrients》2022,14(11)
The objective of the present study was the evaluation of cytokine patterns in terms of TNF-α, IL-10, IL-6, and IL-1β secretion in peripheral blood mononuclear cell (PBMC) supernatants isolated from blood of children affected by generalized epilepsy and treated in vitro with myofibrillar, sarcoplasmic, and total protein fractions of meat and fish sources. Children with generalized epilepsy (EC group, n = 16) and children without any clinical signs of disease, representing a control group (CC group n = 16), were recruited at the Complex Structure of Neuropsychiatry Childhood-Adolescence of Policlinico Riuniti (Foggia, Italy). Myofibrillar (MYO), sarcoplasmic (SA), and total (TOT) protein fractions were obtained from longissimus thoracis muscle of beef (BF) and lamb (LA); from pectoralis muscle of chicken (CH); and from dorsal white muscle of sole (Solea solea, SO), European hake (Merluccius merluccius, EH), and sea bass fish (Dicentrarchus labrax, SB), respectively. PBMCs were isolated from peripheral blood of EC and CC groups, and an in vitro stimulation in the presence of 100 μg/mL for each protein fraction from different meat sources was performed. Data were classified according to three different levels of cytokines produced from the EC group relative to the CC group. TNF-α, IL-10, and IL-6 levels were not affected by different meat fractions and meat sources; on the contrary, IL-1β levels were found to be significantly affected by the tested proteins fractions, as well as different meat sources, in high-level cytokine group. On average, the protein fractions obtained from LB, BF, and CH meat sources showed a higher level of IL-1β than the protein fractions obtained from EH and SB fish samples. When all cytokine classes were analyzed, on average, a significant effect was observed for IL-10, IL-1β, and TNF-α. Data obtained in the present study evidence that the nutritional strategy based on protein from fish and meat sources may modulate the immunological cytokine pattern of infants with generalized epilepsy. 相似文献
74.
Fabrizia Lisso Maddalena Massari Micaela Gentilucci Chiara Novielli Silvia Corti Leonardo Nelva Stellio Roberta Milazzo Ersilia Troiano Ella Schaefer Irene Cetin Chiara Mand 《Nutrients》2022,14(9)
Background: Nutritional quality during pregnancy is crucial for mother and child health and their short/long-term outcomes. The aim of this study is to evaluate the adherence to nutritional recommendations in Italy during the three pregnancy trimesters in Normal Weight (NW) and Over Weight (OW) women. Methods: Data from a multicenter randomized controlled trial included 176 women (NW = 133; OW = 43) with healthy singleton pregnancies enrolled within 13 + 6 weeks of gestation. Dietary intake was assessed every trimester by a Food Frequency Questionnaire. Results: OW and NW had similar gestational weight gain. However, as Institute of Medicine (IOM) recommend lower gestational weight gain (GWG) for OW, they exceeded the suggested range. In both groups, caloric intake during the three trimesters never met recommendations. Protein intake in first and second trimester was higher than recommendations, as was sugars percentage. Dietary fiber intake was lower in OW. Polyunsaturated fatty acids, calcium, iron and folic acid requirements were never satisfied, while sodium intake exceeded recommendations. Conclusions: NW and OW women in Italy do not adhere to nutritional recommendations during pregnancy, with lower caloric intake, protein and sugars excess and inadequacies in micronutrients intake. Pregnant women in Italy should be provided with an adequate counseling and educational intervention as well as supplementation when indicated. 相似文献
75.
Valentina Gizzonio Pietro Avanzini Maddalena Fabbri-Destro Cristina Campi Giacomo Rizzolatti 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2014,232(7):2381-2390
The aim of the present study was to assess the cognitive profiles of children with autistic spectrum disorder and of their healthy siblings (Siblings). With the term cognitive profile, we indicate the relationship extant among the values of verbal and performance subtests of the Wechsler Intelligence Scale. The conducted statistical analyses indicated that, although siblings showed a normal intelligent quotient and did not differ in this aspect from typically developing group, their cognitive profile was amazingly similar to that of their relatives affected by autism. A k-means clustering analysis on the values of single subtests further confirmed this result, showing a clear separation between typically developing children on the one side, and autistics and their siblings on the other. We suggest that the common cognitive profile observed in autistic children and their siblings could represent a marker of liability to autism and, thus, a possible intermediate phenotype of this syndrome. 相似文献
76.
77.
Roberta Cocchiara Giovanna Di Trapani Antonina Azzolina Domenico Geraci 《Journal of immunoassay & immunochemistry》2013,34(4):337-352
Abstract An ELISA assay is described for the measurement of the smIgG. The method is based on the detection of cell-smIgG directly on the same microplate used for the culture. The cells, preincubated at 37°C for one hour, were cultured in the presence of S-ConA and serum-free medium for two days. Using this strategy, the background noise due to non specific adsorbtion of IgG to plastic wells and cytophilic antibodies was eliminated. The cells in the presence of S-ConA and serum-free medium adhered to the plastic wells, and the cell-smIgG were detected using an anti-human IgG covalently linked to alkaline phosphatase or its F(ab')2 fragment. The possibility of measuring the modulation of the expression of the cell-smIgG without any additional manipulation is stressed. 相似文献
78.
79.
Adele Tessitore Miriam Patella Mauro Giuliani Thomas Theologou Stefania Freguia Eleonora Maddalena Minerva Gregor Rugel Stefano Cafarotti 《Interactive Cardiovascular and Thoracic Surgery》2021,32(3):367
We report the first surgical series of patients developing pleural empyema after severe bilateral interstitial lung disease in confirmed severe acute respiratory syndrome coronavirus 2 infection. The empyema results in a complex medical challenge that requires combination of medical therapies, mechanical ventilation and surgery. The chest drainage approach was not successful to relieve the symptomatology and to drain the excess fluid. After multidisciplinary discussion, a surgical approach was recommended. Even though decortication and pleurectomy are high-risk procedures, they must be considered as an option for pleural effusion in Coronavirus disease-positive patients. This is a life-treating condition, which can worsen the coronavirus disease manifestation and should be treated immediately to improve patient’s status and chance of recovery. 相似文献
80.
Anna Rita Giuliani Antonella Mattei Flavio Santilli Giovanna Clori Maria Scatigna Leila Fabiani 《Journal of community health》2014,39(3):531-537
On 6 April 2009, the city of L’Aquila was hit by a violent earthquake that destroyed almost all of its medieval centre, and the surviving inhabitants were evacuated and relocated in temporary quarters or undamaged homes. The aim of this study was to investigate the perceived quality of life of the elderly population 3 years after the earthquake in relation to the social and logistic issues of new housing. The study was carried out between October 2011 and March 2012, and involved 571 subjects aged over 65 years living in the municipality of L’Aquila. The interviews took place in the surgeries of general practitioners and the city’s Department of Prevention and Vaccination in the anti-influenza immunisation period. The instrument used was a 36-item questionnaire with closed, multiple choice answers divided into the following sections: demographics, everyday activities, health and perceived health, and the quality of life in the city. The results show that, 3 years after the earthquake, the elderly population living in the new towns and temporary housing of L’Aquila have a worse perception of their quality of life than the others. They feel a certain social isolation and wish to live elsewhere. Governments faced with the problems arising from a natural calamity should take into account all of the elements making up a good quality of life and, before making choices whose impact cannot be changed, consider both their immediate and long-term social consequences. 相似文献