全文获取类型
收费全文 | 583篇 |
免费 | 31篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 34篇 |
妇产科学 | 8篇 |
基础医学 | 88篇 |
口腔科学 | 10篇 |
临床医学 | 22篇 |
内科学 | 52篇 |
皮肤病学 | 6篇 |
神经病学 | 24篇 |
特种医学 | 11篇 |
外科学 | 192篇 |
综合类 | 3篇 |
预防医学 | 48篇 |
眼科学 | 49篇 |
药学 | 43篇 |
中国医学 | 3篇 |
肿瘤学 | 20篇 |
出版年
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 17篇 |
2020年 | 7篇 |
2019年 | 13篇 |
2018年 | 12篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 12篇 |
2014年 | 9篇 |
2013年 | 12篇 |
2012年 | 18篇 |
2011年 | 25篇 |
2010年 | 14篇 |
2009年 | 10篇 |
2008年 | 27篇 |
2007年 | 24篇 |
2006年 | 24篇 |
2005年 | 17篇 |
2004年 | 12篇 |
2003年 | 23篇 |
2002年 | 17篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 11篇 |
1998年 | 5篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 6篇 |
1992年 | 19篇 |
1991年 | 21篇 |
1990年 | 14篇 |
1989年 | 15篇 |
1988年 | 11篇 |
1987年 | 18篇 |
1986年 | 11篇 |
1985年 | 26篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1981年 | 3篇 |
1979年 | 14篇 |
1978年 | 5篇 |
1975年 | 5篇 |
1973年 | 7篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1969年 | 5篇 |
1968年 | 3篇 |
1967年 | 7篇 |
1966年 | 3篇 |
排序方式: 共有614条查询结果,搜索用时 15 毫秒
1.
2.
3.
D F du Toit 《SADJ》2003,58(9):375-6, 380-3
The tongue (L. lingua; G. glossa) functions as a digestive organ by facilitating the movement of food during mastication and assisting swallowing. Other important functions include speech and taste. The tongue consists of striated muscle and occupies the floor of the mouth. The dorsal mucosal surface consists of stratified squamous epithelium, with numerous papillae and taste buds. The tongue, a voluntary muscular structure, is attached by a fold, called the frenulum, to the floor of the mouth. Typically, between 8 and 12 circumvallate papillae are arranged in an inverted V-shape towards the base of the tongue. This anatomical review focuses on structure, function relationships and diseases affecting the tongue. From a primary oral health care perspective, this overview will facilitate the process of differential diagnosis in persons presenting with vesiculo-bullous, ulcerative, atrophic and cystic disorders of the tongue. Suspicious lesions should be biopsied to rule out carcinoma. 相似文献
4.
Rènée du Toit Katherine Soong Garry Brian Jacqueline Ramke 《Optometry and vision science》2006,83(8):582-588
PURPOSE: The advantages of a focometer (FOCOMETER) over other methods of refraction for use in developing countries are that it is lightweight, compact, relatively inexpensive, fairly quick, and easy to use with minimal training. This clinical trial compared the repeatability, validity, and ease of use of the focometer with an autorefractor. METHODS: The refractive status of the right eye of 80 participants was determined with an autorefractor (Canon RK3). Three measurements were also taken with the focometer. RESULTS: The spherical equivalent (M) of the focometer was 0.25 D more positive than the autorefractor (p < 0.001) and 84% of measurements were within 0.75 D of the autorefractor. The autorefractor detected astigmatism in 91% (73) of the eyes, whereas the focometer identified only 32% (26). The design of the clock target restricts cylinder axis accuracy to the nearest 15 degrees . There was evidence of a learning effect for the focometer: the second and third measurements were more repeatable in the untrained group. There were no differences between the mean (1.03 +/- 2.28) and third focometer (-1.05 +/- 2.32) measurements (p = 0.34). However, using the third focometer measurement, 94% of participants had visual acuities of at least 6/12(-2). CONCLUSIONS: This study highlighted the focometer's restricted power range, inaccuracy of astigmatism and axis determination, and dependence on subject understanding and compliance. Therefore, in most clinical settings, the focometer would not be adequate for quantifying refractive error, but the focometer spherical equivalent was within acceptable limits of the autorefractor, and the visual acuity with lenses determined by the focometer indicates its potential usefulness in public health settings, especially where only spherical ready-made spectacles are dispensed. There may be more cost-effective ways to determine refractive error in these circumstances. A potentially important enhancement in focometer methodology that improves its ease of use was identified: use only the third measurement for each eye. 相似文献
5.
6.
D F Du Toit J J Heydenrych B Smit G Louw T Zuurmond D Els A Weideman S Wolfe-Coote L Du Toit R Gonin 《Journal of surgical oncology》1987,36(2):148-153
In this study the endocrine function following intraperitoneal hetero- and orthotopic pancreatico-duodenal-splenic allotransplantation (PDS) in hemipancreatectomized, non-immune-suppressed chacma baboons was assessed. Significantly reduced K-values and insulin release together with glucose intolerance during IVGTT were observed in hemipancreatectomized recipients (HPS) without grafts. Orthotopic and heterotopic PDS transplantation improved the glucose intolerance of HPS recipients; orthotopically sited grafts rendering the best curves. Normal glucose tolerance was not achieved. Both orthotopic and heterotopic PDS transplantation rendered suboptimal insulin release during IVGTT; heterotopically draining grafts released significantly more insulin than orthotopic grafts. Hyperglucagonaemia during IVGTT was a constant feature in both groups, heterotopic grafts releasing the most glucagon during stimulation. C-peptide release was significantly lower in orthotopic grafts compared to normal animals or heterotopically drained insulin. It is concluded that glucose tolerance was not directly related to insulin or glucagon release in this study as orthotopic grafts rendered near-normal IVGTT curves in the presence of hypoinsulinaemia, hyperglucagonaemia, and reduced C-peptide values. The hormonal response after PDS transplantation was variable and the advantages of portal vs systemic insulin drainage remain to be defined. 相似文献
7.
H J Odendaal R C Pattinson R du Toit D Grove 《Suid-Afrikaanse tydskrif vir geneeskunde》1988,74(1):19-21
Abruptio placentae occurred in 16 of 132 patients with severe pre-eclampsia who were admitted to an obstetric high-risk ward before 34 weeks' gestation. These 16 patients were compared with those who did not develop abruptio placentae. Systolic and diastolic blood pressure levels, proteinuria and birth weights did not differ significantly between the two groups. Apgar scores were significantly lower in the abruptio placentae group. There were 6 intra-uterine and 2 neonatal deaths in the abruptio placentae group (50% perinatal mortality (PNM] and 3 intra-uterine and 16 neonatal deaths in the other group (18% PNM). Four patients with abruptio placentae presented with abnormal fetal heart-rate patterns and 8 with abdominal pain. No warning signs were present in 3 patients and the fetal heart-rate pattern before delivery was not available in 1 patient. Abnormal fetal heart-rate patterns were present in 5 of the 8 patients who presented with pain. Abruptio placentae occurring in patients with severe proteinuric hypertension carries a high PNM. Frequent monitoring of the fetal heart rate sometimes helps to diagnose fetal distress before the clinical signs of abruption become apparent. 相似文献
8.
9.
10.
The present study tested the hypothesis that a reduction in calcium flux across the sarcolemma or the sarcoplasmic reticulum at the onset of reperfusion could attenuate subsequent mechanical "stunning" (postischemic myocardial dysfunction). The isolated working rat heart was subjected to 20 minutes of total global ischemia, reperfused in the Langendorff mode for 5 minutes, and then made to work again for 10 minutes. During the early reperfusion period (first 2 minutes), the effects of agents thought to increase cytosolic calcium (high external calcium [modified Tyrode's solution replaced Krebs-Henseleit buffer as the perfusate], isoproterenol, forskolin, and Bay K 8644) were tested. All these interventions worsened stunning. The cardiac output (CO) of control hearts recovered to 74.7 +/- 3.4%, whereas recovery was 56.3 +/- 3.7% (p less than 0.05) for high calcium (10 mM), 53.4 +/- 3.6% (p less than 0.05) for isoproterenol, 43.4 +/- 4.1% (p less than 0.05) for Bay K 8644, and 62.7 +/- 2.4% (p less than 0.002) for forskolin. Interventions aimed at limiting calcium flux during early reperfusion, such as reperfusion with a low extracellular calcium or the addition of ryanodine (3 x 10(-9) M), nisoldipine (10(-8) M), or the inorganic blockers Mn2+ (2 mM) or Mg2+ (16 mM), were also tested. Low extracellular calcium (0.75 mM) improved CO to 91.8 +/- 0.8% (p less than 0.05). Reperfusion with ryanodine and nisoldipine gave CO recoveries of 103.6 +/- 1.8% (p less than 0.002) and 99.0 +/- 2.8% (p less than 0.002), respectively.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献