全文获取类型
收费全文 | 7224篇 |
免费 | 505篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 123篇 |
儿科学 | 197篇 |
妇产科学 | 186篇 |
基础医学 | 928篇 |
口腔科学 | 371篇 |
临床医学 | 574篇 |
内科学 | 1801篇 |
皮肤病学 | 163篇 |
神经病学 | 492篇 |
特种医学 | 343篇 |
外科学 | 852篇 |
综合类 | 36篇 |
一般理论 | 3篇 |
预防医学 | 616篇 |
眼科学 | 103篇 |
药学 | 529篇 |
中国医学 | 41篇 |
肿瘤学 | 420篇 |
出版年
2023年 | 43篇 |
2022年 | 138篇 |
2021年 | 223篇 |
2020年 | 134篇 |
2019年 | 216篇 |
2018年 | 269篇 |
2017年 | 169篇 |
2016年 | 214篇 |
2015年 | 245篇 |
2014年 | 307篇 |
2013年 | 345篇 |
2012年 | 506篇 |
2011年 | 507篇 |
2010年 | 282篇 |
2009年 | 260篇 |
2008年 | 384篇 |
2007年 | 396篇 |
2006年 | 314篇 |
2005年 | 290篇 |
2004年 | 267篇 |
2003年 | 257篇 |
2002年 | 218篇 |
2001年 | 191篇 |
2000年 | 174篇 |
1999年 | 176篇 |
1998年 | 82篇 |
1997年 | 72篇 |
1996年 | 44篇 |
1995年 | 42篇 |
1994年 | 35篇 |
1993年 | 33篇 |
1992年 | 78篇 |
1991年 | 82篇 |
1990年 | 81篇 |
1989年 | 45篇 |
1988年 | 44篇 |
1987年 | 59篇 |
1986年 | 48篇 |
1985年 | 62篇 |
1984年 | 42篇 |
1983年 | 35篇 |
1981年 | 20篇 |
1980年 | 21篇 |
1979年 | 38篇 |
1978年 | 21篇 |
1975年 | 26篇 |
1974年 | 27篇 |
1973年 | 26篇 |
1969年 | 23篇 |
1968年 | 19篇 |
排序方式: 共有7778条查询结果,搜索用时 31 毫秒
1.
2.
Alessia Scarselli Silvia Di Cesare Claudia Capponi Simona Cascioli Maria L. Romiti Gigliola Di Matteo Alessandra Simonetti Paolo Palma Andrea Finocchi Barbarella Lucarelli Rita M. Pinto Ippolita Rana Giuseppe Palumbo Maurizio Caniglia Paolo Rossi Rita Carsetti Caterina Cancrini Alessandro Aiuti 《Journal of clinical immunology》2015,35(4):373-383
3.
Pedro Lopez Matheus Daros Pinto Ronei Silveira Pinto 《Ultrasound in medicine & biology》2019,45(2):612-616
In the work described here, our aim was to determine, in an elderly population, changes in muscle thickness (MT), cross-sectional area (CSA) and echo intensity (EI) of the quadriceps muscles at four time points (0, 5, 10 and 15 min; i.e., T0, T5, T10 and T15, respectively) after changing from a standing to supine position. Twenty-one elderly participants (14 men: 68.1 ± 4.6 y; 8 women: 66.8 ± 4.1 y) were evaluated at four time points. Rectus femoris CSA (RFCSA), MT and EI of the quadriceps femoris (QF) muscles were assessed. EI significantly increased from T0 to T5, T10 and T15 (p < 0.001), whereas no differences were observed between T5 and T15 in the rectus femoris (RFEI), vastus intermedius (VIEI) and quadriceps femoris (QFEI). No differences were observed between any time points in the RFCSA and MT of QF muscles. In summary, these results suggest that periods >5 min are not necessary to obtain consistent MT and EI measurements of quadriceps femoris muscles in the elderly population. 相似文献
4.
Paula Cristina Galati Paula Garcia Chiarello Belinda Pinto Simões 《Nutrition and cancer》2016,68(1):86-93
Changes in resting energy expenditure (REE) of cancer patients vary depending on type of tumor, treatment time point and kind of treatment. Little is known about REE of acute leukemia adult patients after treatment, especially with results related to body weight or fat free mass (FFM). This study aimed to assess changes in REE of acute leukemia adult patients before and after the first remission induction. Evaluation of REE was performed by indirect calorimetry and predicted REE was calculated by Harris-Benedict equation. Weight and height were measured and compared to a control group of healthy individuals. FFM was assessed by bioelectrical impedance for adjusting REE values. We evaluated 18 patients and 26 healthy individuals. At diagnosis, patients presented REE, REE/weight, and REE/FFM higher than the controls. Reductions of REE, REE/weight, and REE/FFM were also observed in patients after the first cycle of chemotherapy. The predicted REE for the patients group showed significant lower value compared with measured REE. Before the first cycle of chemotherapy REE was increased but undergoes a reduction after treatment, reaching values similar to the controls. For predictive Harris-Benedict equation, stress factors should be added to avoid underestimation of REE before and after chemotherapy. 相似文献
5.
6.
Eduardo Rodrigues‐Pinto Joel Ferreira‐Silva Guilherme Macedo Douglas K. Rex 《Digestive endoscopy》2019,31(5):583-587
Cecal intubation is a critical aspect of effective, complete colonoscopy. Difficult colonoscopy is most often considered as one in which it is challenging or impossible to reach the cecum. It may be a common occurrence due to patient and/or endoscopist factors. Incomplete colonoscopies should be avoided, since patients in this context present an important prevalence of lesions that escape examination. The approach to successful cecal intubation should depend on characterization of the problem as redundant colon or difficult sigmoid colon. Most patients with a prior incomplete colonoscopy can be colonoscoped successfully, if careful attention is paid to technique, using a variety of scopes, colonoscopy methods and additional equipment. Sufficient time should be allotted to make the attempt. 相似文献
7.
8.
A Todo-Bom A Mota Pinto V Alves S Vale Pereira M Santos Rosa 《Journal of investigational allergology & clinical immunology》2007,17(2):107-112
BACKGROUND: Asthma is a chronic inflammatory disorder of the airways. The persistence of airway inflammation depends on a decrease in apoptosis of T lymphocytes and eosinophils and survival of these activated cells. T lymphocytes expressing gamma delta receptors can be identified in human lungs and play an important role in immune defence against pathogens and in the regulation of chronic inflammation. Aging is associated with evidence of some immune dysregulation. OBJECTIVE: The aim of this study was to analyze the apoptosis receptors of T lymphocytes in long-lasting asthma, to establish their correlation with activation markers such as CD25+ and human leukocyte antigen (HLA)-DR+, and to analyze the gama delta T cell expression in this disease. METHODS: A group of 64 individuals (group A) who had had asthma for more than 30 years (mean age [+/-SD] 72 +/- 5 years) and 61 healthy individuals acting as controls--group B with 41 individuals (mean age 79 +/- 7 years) and group C with 20 individuals (mean age 38 +/- 12 years) were included in the study. All subjects underwent clinical evaluation and spirometric testing. Peripheral blood cells were stained with monoclonal antibodies anti-CD3, anti-CD4, anti-CD8, anti-CD25, anti-TCR gamma delta, anti-HLA-DR and anti-CD95. Statistical comparisons were performed between the asthmatics and the elderly control group and between the elderly control group and the adult control group. RESULTS: The average percentage of predicted forced expiratory volume in the first second was 73.6 gamma delta 25.3. The mean values of T cell receptors for asthma group A vs elderly control group B vs adult control group C respectively, were the following: CD3, 74.9+/-7 vs. 74.8 +/- 8.8 (P=ns) vs. 76.7 +/- 4.2 (P=ns); CD4, 48.8 +/- 8.7 vs. 43.5 +/- 10.2 (P=ns) vs. 44.8 +/- 3.8 (P=ns); CD8, 23.3 +/- 7.9 vs. 25.7 +/- 10.2 (P=ns) vs. 25.6 +/- 4.5 (P=ns); CD25, 14.3 +/- 5.9 vs. 22.4 +/- 7.8 (P = .0001) vs. 5.5 +/- 2.4 (P = .0001); TCR gamma delta, 2.8 +/- 2.1 vs. 4.1 +/- 3.3 (P < .05) vs. 4.6 +/- 2.1 (P=ns); HLA-DR, 18.4 +/- 9.2 vs. 17.8 +/- 5.9 (P=ns) vs. 15.4 +/- 5.1 (P=ns) and CD95, 49.3 +/- 13.7 vs. 52.6 +/- 12.1 (P=ns) vs. 13.8 +/- 10.8 (P = .0001). CONCLUSIONS: The immunological and inflammatory changes related to ageing may cause an increase in CD95 and CD25 T cell expression. In asthma, blood cells may express increased activation and apoptosis markers but in elderly patients taking steroids, these receptors remain within normal ranges. The number of gamma delta T cells may be lower in long-lasting asthma, and have a limited modulatory effect on allergic inflammatory reactions. The evaluation of patients with long-lasting asthma should take into account the immunological and inflammatory changes present in the elderly in order to avoid results being misinterpreted. 相似文献
9.
Eric T. Stoopler DMD res Pinto DMD Faizan Alawi DDS Sree Raghavendra DMD Ricardo Boyce Jr. DDS David Porter MD Thomas P. Sollecito DMD 《Special care in dentistry》2004,24(2):65-69
Acute myelogenous leukemia (AMU is a hematologic disorder that is characterized by an abnormal proliferation of immature myeloid cells. Granulocytic sarcomas are clusters of leukemic myeloid cells that may develop as a result of AML. Oral manifestations of AML are common and often involve enlargements of the gingiva and/or mucosal tissue from direct leukemia cell infiltration. We describe the case history of a 50-year-old man who had an ulcera-tive lesion of the oral mucosa that was determined to be a granulocytic sarcoma of AML-M0 subtype. The combination of both the subtype and clinical presentation of the leukemia makes this presentation unusual, and to the best of our knowledge, of a type that has not been previously reported in the literature. 相似文献
10.
A V Pinto V F Ferreira R S Capella B Gilbert M C Pinto J S da Silva 《Transactions of the Royal Society of Tropical Medicine and Hygiene》1987,81(4):609-610
Accidental transmission of Chagas disease to man by blood transfusion is a serious problem in Latin America. This paper describes the testing of several naphthoquinones, some of which were active against blood trypomastigotes in vitro at 4 degrees C and might therefore warrant further study for preventing transmission of Chagas disease by blood transfusion. 相似文献