全文获取类型
收费全文 | 1222篇 |
免费 | 123篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 15篇 |
妇产科学 | 27篇 |
基础医学 | 187篇 |
口腔科学 | 52篇 |
临床医学 | 107篇 |
内科学 | 252篇 |
皮肤病学 | 26篇 |
神经病学 | 114篇 |
特种医学 | 32篇 |
外科学 | 196篇 |
综合类 | 4篇 |
一般理论 | 1篇 |
预防医学 | 117篇 |
眼科学 | 11篇 |
药学 | 112篇 |
肿瘤学 | 79篇 |
出版年
2023年 | 11篇 |
2022年 | 7篇 |
2021年 | 14篇 |
2020年 | 22篇 |
2019年 | 20篇 |
2018年 | 34篇 |
2017年 | 30篇 |
2016年 | 31篇 |
2015年 | 25篇 |
2014年 | 38篇 |
2013年 | 59篇 |
2012年 | 62篇 |
2011年 | 62篇 |
2010年 | 35篇 |
2009年 | 40篇 |
2008年 | 54篇 |
2007年 | 41篇 |
2006年 | 44篇 |
2005年 | 52篇 |
2004年 | 36篇 |
2003年 | 34篇 |
2002年 | 61篇 |
2001年 | 53篇 |
2000年 | 33篇 |
1999年 | 34篇 |
1998年 | 18篇 |
1997年 | 14篇 |
1996年 | 5篇 |
1995年 | 9篇 |
1994年 | 12篇 |
1993年 | 10篇 |
1992年 | 32篇 |
1991年 | 31篇 |
1990年 | 28篇 |
1989年 | 20篇 |
1988年 | 26篇 |
1987年 | 22篇 |
1986年 | 26篇 |
1985年 | 23篇 |
1984年 | 15篇 |
1983年 | 17篇 |
1982年 | 9篇 |
1981年 | 11篇 |
1979年 | 9篇 |
1978年 | 7篇 |
1974年 | 9篇 |
1971年 | 4篇 |
1969年 | 11篇 |
1957年 | 4篇 |
1955年 | 4篇 |
排序方式: 共有1346条查询结果,搜索用时 31 毫秒
71.
Flick KC Orendurff MS Berge JS Segal AD Klute GK 《Prosthetics and orthotics international》2005,29(1):73-81
Given the importance of minimizing transverse plane shear stress on soft tissue, several transverse rotational adapters (TRAs) are available for incorporation in lower limb prostheses. This study compares kinetic and kinematic data from human subjects during straight and turning gaits to the mechanical performance of several TRAs. Physiological data were collected from three individuals walking straight and turning at self-selected speeds around a 1 m radius circle. The average peak torques and range of motion for normal subjects while turning were 8.2 Nm and 26 degrees (outside leg), 11.8Nm and 20 degrees (inside leg), and 11.4 Nm and 20 degrees (right leg) during straight gait. Each TRA was mechanically tested without axial loading in a servo-hydraulic material testing system (MTS) over its rotational range at 0.5 dergrees/s and 60 degrees/s. The TRAs with axial compression were also tested at 0.5 degrees/s under a 736N (75kg mass) axial load. Applying these torques to the different TRAs yielded 3 to 35 degrees rotation, depending on the elastomer installed. Some TRAs had nearly constant stiffness, while others stiffened with rotation. The TRAs also varied in their average maximum stiffness from 0.4Nm/degree to 2.7Nm/degrees. Normal subjects exhibit interior vs. exterior asymmetrical torques and displacements; however, only one of the TRAs is designed to allow asymmetrical stiffness, and none have asymmetric ranges. Prosthetists and physicians can use these data to better interpret amputees' qualitative remarks and to prescribe the correct TRA and/or elastomer. This information also forms a basis for further design and development of novel torque absorbing prosthetic adapters. 相似文献
72.
Breek JC de Vries J van Heck GL van Berge Henegouwen DP Hamming JF 《Journal of vascular surgery》2005,41(3):443-450
OBJECTIVE: To describe similarities and differences between health status and quality of life in patients with intermittent claudication. METHODS: This was an observational study in the vascular outpatient department of a teaching hospital; it concerned 200 consecutive patients with intermittent claudication. Health status was assessed with the RAND-36, and quality of life was assessed with a reduced version of the World Health Organization Quality of Life assessment instrument-100. Scores were compared with those of sex- and age-matched healthy controls. Mann-Whitney U tests were used to detect statistically significant differences ( P < .01) between patients and healthy controls. Pearson correlations were calculated between health status and quality-of-life scores. Differences between correlations were examined by using Fisher z statistics. The upper and lower 10% of quality-of-life scores were compared with the response quartiles of the health status scores. RESULTS: Health status was significantly impaired in all domains. Quality of life was significantly worse with respect to aspects of physical health and level of independence and one global evaluative facets overall quality of life and general health. Quality-of-life assessment with the World Health Organization Quality of Life instrument disclosed patient-reported problems that had not been identified in health status. Conversely, patients did not regard all objective functional impairments as a problem. Pearson correlations ranged from 0.20 to 0.74. There were patients with excellent and very poor quality-of-life scores in nearly all the quartiles of the corresponding health status domains. CONCLUSIONS: Health status and quality of life represent different outcomes in patients with intermittent claudication. In addition to functional restrictions as measured in health status, quality of life also permits a personal evaluation of these restrictions. Objective functioning and subjective appraisal of functioning are complementary and not identical. Combining these measures should direct treatment in a way that meets patients' needs. 相似文献
73.
74.
A growing body of literature suggests that some moisturizers can improve stratum corneum barrier function, as well as ameliorate dry skin. The clinical signs and symptoms of rosacea, which include increased facial skin dryness and sensitivity, suggest a possible role for such moisturizers as an adjuvant in the management of this condition. This randomized, investigator-blind, controlled observational study (N = 50) was designed to assess whether a niacinamide-containing facial moisturizer would improve the stratum corneum barrier and thus provide a clinical benefit to subjects with rosacea. Subjects with rosacea applied the test moisturizer to their face and to one forearm twice daily for 4 weeks. The other forearm remained untreated as a control. Barrier function on the forearms was assessed instrumentally and using a dimethyl sulfoxide (DMSO) chemical probe. Stratum corneum hydration also was measured instrumentally. The dermatologist investigator evaluated each subject's rosacea condition over the course of the study, and subjects self-assessed their facial skin condition at study end. Instruments provided objective measures of stratum corneum barrier function and hydration on the face. 相似文献
75.
Different levels of platelet activation in preeclamptic, normotensive pregnant, and nonpregnant women 总被引:5,自引:0,他引:5
Holthe MR Staff AC Berge LN Lyberg T 《American journal of obstetrics and gynecology》2004,190(4):1128-1134
OBJECTIVE: The aims of our study were to determine the basal platelet activation state in women with preeclampsia compared with normotensive pregnant women and nonpregnant women and to investigate the platelet reactivity on in vitro stimulation with adenosine diphosphate or thrombin receptor activation peptide. STUDY DESIGN: Platelet expression of CD61 (fibrinogen receptor), CD42a (von Willebrand factor receptor), CD62P (P-selectin), CD63 (Glycoprotein 53), and PAC-1 binding (activated fibrinogen receptor) were determined in 20 pairs of women with preeclampsia/normotensive pregnant women and in 12 nonpregnant women, with the use of flow cytometry. RESULTS: Basal platelet expression of CD61, CD42a and CD62P, and adenosine diphosphate-stimulated CD62P expression were increased in women with preeclampsia compared with normotensive pregnant women. Platelets from women with preeclampsia and normotensive pregnant women differed from platelets from nonpregnant women by expressing higher basal CD63 levels and being more responsive to in vitro agonist stimulation, which was demonstrated by increased expression of CD61, CD62P, and CD63. CONCLUSION: This study supports the notion that platelets are important in the pathophysiologic condition of preeclampsia. 相似文献
76.
Aukrust P Müller F Svardal AM Ueland T Berge RK Frøland SS 《The Journal of infectious diseases》2003,188(2):232-238
Oxidative stress has been implicated in the pathogenesis of human immunodeficiency virus (HIV) infection. We examined the effect of highly active antiretroviral therapy (HAART) on plasma levels of several antioxidants and intracellular glutathione-redox status in CD4+ T cells, in 20 HIV-infected patients. HAART was accompanied by both an improvement of glutathione-redox status and an increase in levels of antioxidant vitamins, without full normalization. Glutathione supplementation in vitro increases T cell proliferation and suppresses the spontaneous release of tumor necrosis factor-alpha from peripheral blood mononuclear cells, in HIV-infected patients receiving HAART. Our findings suggest that therapeutic intervention aimed at normalization of oxidative disturbances in HIV infection could be of interest, in addition to HAART. 相似文献
77.
Swaddling, ie, wrapping the child to restrict movement, is an ancient practice. In the Netherlands, it is becoming increasingly popular as an intervention for excessive crying in infants. However, one must be well aware of the potential risks. We present the case reports of a twin boy and girl who had been swaddled and kept in a heated room for several days. On admission to the hospital, both infants suffered from severe hypovolemic shock, hyperthermia, and secondary respiratory insufficiency. The girl developed multiple organ dysfunction syndrome and died, whereas the boy had an uneventful recovery. When swaddling is being considered as an intervention for excessive crying in infants, parents have to be well-informed about the possible side effects and about additional measures that they may have to take to make it a safe intervention. 相似文献
78.
79.
Fatty acids and other lipids have multiple roles in the cell, functioning as structural components, participating in intracellular signalling and serving as metabolic fuel. Various compounds that influence cellular lipid metabolism can reduce the growth of malignant cells, and dietary as well as pharmacological strategies for modulating lipid metabolism have therefore been suggested as possible approaches for cancer prevention and treatment. By chemically modifying fatty acids (e.g., butyrates, retinoids), new potential anticancer agents have been produced that possess increased metabolic stability and more specific and potent biological activity compared to the natural fatty acids. Possible therapeutic targets for such modified fatty acids include: i) Histone deacetylase; ii) nuclear hormone receptors (retinoid receptors), peroxisome proliferator-activated receptors; iii) cyclooxygenase-2; iv) intracellular signalling involving protein farnesylation and Ras activation; and v) various mitochondrial functions. Although several fatty acid derivatives have been thoroughly investigated in experimental models, clinical data on toxicity and pharmacological interactions are not available for the majority of these agents. However, several promising novel compounds are now being evaluated in preclinical and early clinical studies, and future research will hopefully reveal new formulations and therapy schedules that will improve the outcome of patients with malignant disorders. 相似文献
80.
Norheim AJ Pedersen EJ Fønnebø V Berge L 《Scandinavian journal of primary health care》2001,19(1):43-47
OBJECTIVE: To find out whether acupressure wristband can alleviate nausea and vomiting in early pregnancy. DESIGN: Double-blind, placebo-controlled study. SUBJECTS: 97 women with mean gestational length completed 8-12 weeks. MAIN OUTCOME MEASURES: Symptoms were recorded according to intensity, duration and nature of complaints. RESULTS: 71% of women in the intervention group reported both less intensive morning sickness and reduced duration of symptoms. The same tendency was seen in the placebo group, with 59% reporting less intensity and 63% shorter duration of symptoms. However, a significance level of 5% was reached only in the case of duration of symptoms, which was reduced by 2.74 hours in the intervention group compared to 0.85 hours in the placebo group (p = 0.018). CONCLUSIONS: Acupressure wristband might be an alternative therapy for morning sickness in early pregnancy, especially before pharmaceutical treatment is considered. 相似文献