全文获取类型
收费全文 | 1453篇 |
免费 | 90篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 25篇 |
儿科学 | 81篇 |
妇产科学 | 108篇 |
基础医学 | 163篇 |
口腔科学 | 81篇 |
临床医学 | 135篇 |
内科学 | 318篇 |
皮肤病学 | 14篇 |
神经病学 | 73篇 |
特种医学 | 53篇 |
外科学 | 268篇 |
综合类 | 20篇 |
一般理论 | 1篇 |
预防医学 | 50篇 |
眼科学 | 29篇 |
药学 | 64篇 |
中国医学 | 2篇 |
肿瘤学 | 66篇 |
出版年
2023年 | 14篇 |
2022年 | 16篇 |
2021年 | 46篇 |
2020年 | 24篇 |
2019年 | 56篇 |
2018年 | 42篇 |
2017年 | 45篇 |
2016年 | 67篇 |
2015年 | 57篇 |
2014年 | 57篇 |
2013年 | 84篇 |
2012年 | 105篇 |
2011年 | 75篇 |
2010年 | 53篇 |
2009年 | 51篇 |
2008年 | 93篇 |
2007年 | 116篇 |
2006年 | 101篇 |
2005年 | 86篇 |
2004年 | 47篇 |
2003年 | 41篇 |
2002年 | 47篇 |
2001年 | 30篇 |
2000年 | 19篇 |
1999年 | 35篇 |
1998年 | 10篇 |
1996年 | 5篇 |
1994年 | 5篇 |
1993年 | 4篇 |
1992年 | 13篇 |
1991年 | 14篇 |
1990年 | 10篇 |
1989年 | 5篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 3篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1980年 | 3篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 7篇 |
1972年 | 4篇 |
1971年 | 6篇 |
1970年 | 4篇 |
1969年 | 3篇 |
1968年 | 3篇 |
排序方式: 共有1551条查询结果,搜索用时 380 毫秒
31.
32.
33.
Ahmet Serkan Küçükekenci Doğu Ömür Dede Ersan Çelik 《The Journal of prosthetic dentistry》2021,125(2):350.e1-350.e6
Statement of problemThe clinical performance of implant-retained overdentures (IODs) with plastic bar clips made of different materials in the same design and dimensions may vary according to the patient’s daily home care procedures. However, information about the effects of denture cleaning solutions on the retention of Hader bar clips is lacking.PurposeThe purpose of this in vitro study was to evaluate the retention of Hader bar clips made of different polymers after being soaked in denture cleaning solutions.Material and methodsNinety Hader bar clips made of polyamide (PA, n=30), polytetrafluoroethylene (PTFE, n=30), and polyetherketoneketone (PEKK, n=30) materials were tested. Two multiunit abutments were screwed onto the implant analogs and embedded into an acrylic resin block in a standardized position. The digital scanning of the abutments was acquired, and the bar patrix of each material system milled from a cobalt-chromium (Co-Cr) alloy disk by using computer-aided design and computer-aided manufacturing (CAD-CAM). After the milled bar patrices were screwed onto abutments and the metal housings of the bar clips were embedded into acrylic resin blocks, they were connected passively at the same angulation to a universal testing machine. The initial retention values of all Hader bar clips were measured, and each material system was divided into 3 subgroups (n=10) before soaking in the cleaning solutions: distilled water (DW), 5% sodium hypochlorite (NaOCl), or sodium bicarbonate-sodium perborate (SBSP). Each material was soaked for the equivalent of 3 months of clinical use. The final retention values of each Hader bar clip were measured. The data were statistically analyzed by using a 2-way analysis of variance (ANOVA), the Tukey honestly significant difference (HSD) test, and the paired sample t test (α=.05).ResultsThe 2-way ANOVA showed that the denture cleaning solution, the clip material, and their interactions led to significantly different retention values (P<.001). A decrease was observed for the retention values of all test groups after soaking in the cleaning solutions (P<.05). No retention was observed for the PTFE clips after soaking in the 5% NaOCI solution.ConclusionsThe denture cleaning solutions negatively affected the retention of Hader bar clips, regardless of the type of solution and clip material. The 5% NaOCI solution not only decreased the retention of PTFE clips but also completely degraded it. It is recommended that 5% NaOCI solution be avoided for the daily care of IODs with PTFE clips. 相似文献
34.
35.
The clinic usage of cisplatin, an anticancer drug, is limited due to it has many side effects in many systems and organs. In this context, it was aimed to investigate the protective effect of hesperidin, a citrus flavonoid, on testicular and spermatological damages induced by cisplatin in rats. The rats were randomly divided into four groups. The first group was kept as a control. In the second groups, cisplatin was given at the single dose of 7 mg kg?1 intraperitoneally. In the third group, hesperidin was orally administered at the dose of 50 mg/kg day?1 for 14 days. In the fourth group, cisplatin and hesperidin were given together at the same doses. Cisplatin treatment caused significant reductions enzymatic (SOD, CAT and GPx) and nonenzymatic (GSH) antioxidants and significant induction level of TBARS. In addition, cisplatin treatment caused decreased sperm motility, epididymal sperm concentration, increased abnormal sperm rate and histopathological damage. In contrast, hesperidin treatment significantly attenuated the harmful effects. In conclusion, this study clearly demonstrated that hesperidin has protective effects on cisplatin‐induced reproductive system toxicity depending on its antioxidant properties. Thus, it is thought that hesperidin may be useful against cisplatin toxicity in patients with cancer in terms of reproductive system. 相似文献
36.
K R Segal L Blando F Ginsberg-Fellner A Eda?o 《Metabolism: clinical and experimental》1992,41(8):868-878
To determine the independent impact of physical training on postprandial thermogenesis at rest and after 1 hour of cycling at 100 W, 10 lean (15% +/- 1% body fat), 10 obese (33% +/- 2% fat), and six obese diet-controlled, type II diabetic men (34% +/- 4% fat) underwent 12 weeks of vigorous cycle ergometer training (4 h/wk at approximately 70% of maximum oxygen consumption [VO2max]) while maintaining body weight and composition. Body weight was held constant by refeeding the energy expended in each training session. Cardiorespiratory fitness increased by approximately 27%, but body weight and fat did not change. Before and at least 4 days after the last exercise session, energy expenditure was measured for 3 hours under four conditions: (1) rest, no meal; (2) rest, after a 720-kcal mixed meal; (3) postexercise after 1 hour cycling, no meal; and (4) postexercise, meal after exercise. The thermic effect of food was calculated as postprandial minus postabsorptive energy expenditure at rest and postexercise (kcal/3 h). Before and after training, the thermic effect of food during rest was lower in obese than in lean men, and lower in diabetic than in obese men (P less than .05). Thermogenesis was improved after short-term exercise in obese and diabetic men compared with that at rest, but was not normalized (P less than .05 for lean v obese, diabetic men). A significant effect of training on thermogenesis was due to a small but significant increase after training for diabetic men under the postexercise condition. Thus, while short-term exercise enhances but does not normalize thermogenesis in obese and diabetic men, long-term exercise training leading to increased cardiorespiratory fitness, in the absence of changes in body composition, leads to a small increase in thermogenesis in diabetic men, which manifests only after a short period of exercise. 相似文献
37.
O'Connor BP Eun SY Ye Z Zozulya AL Lich JD Moore CB Iocca HA Roney KE Holl EK Wu QP van Deventer HW Fabry Z Ting JP 《Proceedings of the National Academy of Sciences of the United States of America》2008,105(35):13015-13020
The semaphorin and plexin family of ligand and receptor proteins provides important axon guidance cues required for development. Recent studies have expanded the role of semaphorins and plexins in the regulation of cardiac, circulatory and immune system function. Within the immune system, semaphorins and plexins regulate cell–cell interactions through a complex network of receptor and ligand pairs. Immune cells at different stages of development often express multiple semaphorins and plexins, leading to multivariate interactions, involving more than one ligand and receptor within each functional group. Because of this complexity, the significance of semaphorin and plexin regulation on individual immune cell types has yet to be fully appreciated. In this work, we examined the regulation of T cells by semaphorin 6D. Both in vitro and in vivo T cell stimulation enhanced semaphorin 6D expression. However, semaphorin 6D was only expressed by a majority of T cells during the late phases of activation. Consequently, the targeted disruption of semaphorin 6D receptor–ligand interactions inhibited T cell proliferation at late but not early phases of activation. This proliferation defect was associated with reduced linker of activated T cells protein phosphorylation, which may reflect semaphorin 6D regulation of c-Abl kinase activity. Semaphorin 6D disruption also inhibited expression of CD127, which is required during the multiphase antigen-presenting cell and T cell interactions leading to selection of long-lived lymphocytes. This work reveals a role for semaphorin 6D as a regulator of the late phase of primary immune responses. 相似文献
38.
Chun-Tao Wai Seng-Gee Lim Myot-Oo Aung Yin-Mei Lee Dede S Sutedja Yock-Young Dan Marion M Aw Seng-Hock Quak Margaret K Lee Maureen Da Costa K Prahbakaran Kang-Hoe Lee 《Liver international》2007,27(1):69-75
BACKGROUND AND AIM: Studies on Molecular Adsorbent Recycling Systems (MARS) showed inconclusive survival benefits. PATIENTS AND METHOD: We evaluated the efficacy of MARS for patients with either acute liver failure (ALF) or acute-on-chronic liver failure (AoCLF) at our centre, from February 2002 till April 2006 retrospectively. RESULTS: Fifty ALF patients underwent median (range) three (1-10) sessions of MARS. Acute exacerbations of chronic hepatitis B (n=26) and drug-induced liver injury (n=12) were the commonest causes. Living donors were available in 6, 2 paediatric patients underwent left lobe and four adults underwent right lobe living donor liver transplant. Among the 44 ALF patients without a suitable living donor, one underwent deceased donor liver transplant and survived, another 19-year-old male with acute exacerbations of chronic hepatitis B recovered without transplant, and the rest died. Twenty-six had AoCLF and underwent four (1-10) MARS sessions. Sepsis (n=16) and upper gastrointestinal bleeding (n=4) were the commonest precipitating factors. None had a suitable living or deceased donor, suitable for transplantation during their hospitalization. Only one of 26 AoCLF patients survived the hospitalization, but the survivor died of sepsis 1 month later. CONCLUSION: In this non-randomized study, survival after MARS was related to the availability of transplant, and in patients where living or deceased donor transplant was unavailable, MARS was of little benefit. Randomized-controlled trials on MARS((R)) are urgently needed to clarify its clinical utility. 相似文献
39.
Neslihan Duruturk Eda Tonga Metin Karatas Ersin Doganozu 《Journal of Physical Therapy Science》2015,27(7):2023-2028
[Purpose] To describe the functional consequences of patients with cardiac diseases and
analyze associations between activity limitations and quality of life. [Subjects and
Methods] Seventy subjects (mean age: 60.1±12.0 years) were being treated by Physical
Medicine and Rehabilitation and Cardiology Departments were included in the study.
Activity limitations and participation restrictions as perceived by the individual were
measured by the Canadian Occupational Performance Measure (COPM). The Nottingham Extended
Activities of Daily Living (NEADL) Scale was used to describe limitations in daily living
activities. To detect the impact of activity limitations on quality of life the Nottingham
Health Profile (NHP) was used. [Results] The subjects described 46 different types of
problematic activities. The five most identified problems were walking (45.7%), climbing
up the stairs (41.4%), bathing (30%), dressing (28.6%) and outings (27.1%). The
associations between COPM performance score with all subgroups of NEADL and NHP; total,
energy, physical abilities subgroups, were statistically significant. [Conclusion] Our
results showed that patients with cardiac diseases reported problems with a wide range of
activities, and that also quality of life may be affected by activities of daily living.
COPM can be provided as a patient-focused outcome measure, and it may be a useful tool for
identifying those problems.Key words: Activity limitation, Cardiac diseases, Quality of life 相似文献
40.
Gingival Crevicular Fluid Levels of Sclerostin,Osteoprotegerin, and Receptor Activator of Nuclear Factor‐κB Ligand in Periodontitis 下载免费PDF全文
Umut Balli Ahmet Aydogdu Figen Ongoz Dede Cigdem Coskun Turer Berrak Guven 《Journal of periodontology》2015,86(12):1396-1404
Background: To investigate changes in the levels and relative ratios of sclerostin, osteoprotegerin (OPG), and receptor activator of nuclear factor‐κB ligand (RANKL) in the gingival crevicular fluid (GCF) of patients with periodontitis after non‐surgical periodontal treatment. Methods: Fifty‐four individuals (27 healthy controls and 27 patients with chronic periodontitis [CP]) were enrolled in the study. Periodontitis patients received non‐surgical periodontal therapy. GCF sampling and clinical periodontal parameters were assessed before and 6 weeks after therapy. Sclerostin, OPG, and RANKL levels were measured by enzyme‐linked immunosorbent assay, and their relative ratios were calculated. Results: Total amounts and concentrations of sclerostin were significantly higher in patients with CP than in healthy individuals (P <0.025) and decreased after treatment (P <0.05). The RANKL/OPG ratio was significantly lower in healthy individuals than in patients with periodontitis before and after treatment (P <0.025), but no significant difference was observed in patients with periodontitis after treatment (P >0.05). The sclerostin/OPG and sclerostin/RANKL ratios were significantly lower in healthy individuals than in patients with periodontitis before and after treatment (P <0.025) and decreased in patients with periodontitis after treatment (P <0.05). Conclusions: The GCF sclerostin level may be more reliable than the RANKL/OPG ratio as a diagnostic and prognostic marker of periodontal disease and treatment outcome. Regulation of sclerostin levels may aid the development of new therapeutic strategies for the treatment of periodontal disease. 相似文献