全文获取类型
收费全文 | 67604篇 |
免费 | 7693篇 |
国内免费 | 4797篇 |
专业分类
耳鼻咽喉 | 510篇 |
儿科学 | 701篇 |
妇产科学 | 1303篇 |
基础医学 | 7450篇 |
口腔科学 | 1228篇 |
临床医学 | 11381篇 |
内科学 | 10321篇 |
皮肤病学 | 632篇 |
神经病学 | 3712篇 |
特种医学 | 2283篇 |
外国民族医学 | 52篇 |
外科学 | 6629篇 |
综合类 | 11339篇 |
现状与发展 | 19篇 |
一般理论 | 5篇 |
预防医学 | 4739篇 |
眼科学 | 1892篇 |
药学 | 6995篇 |
41篇 | |
中国医学 | 3520篇 |
肿瘤学 | 5342篇 |
出版年
2024年 | 289篇 |
2023年 | 1352篇 |
2022年 | 2776篇 |
2021年 | 3506篇 |
2020年 | 2748篇 |
2019年 | 2286篇 |
2018年 | 2443篇 |
2017年 | 2341篇 |
2016年 | 2263篇 |
2015年 | 3243篇 |
2014年 | 4018篇 |
2013年 | 3509篇 |
2012年 | 5024篇 |
2011年 | 5504篇 |
2010年 | 3349篇 |
2009年 | 2779篇 |
2008年 | 3549篇 |
2007年 | 3366篇 |
2006年 | 3312篇 |
2005年 | 3235篇 |
2004年 | 2155篇 |
2003年 | 2068篇 |
2002年 | 1716篇 |
2001年 | 1486篇 |
2000年 | 1484篇 |
1999年 | 1755篇 |
1998年 | 1121篇 |
1997年 | 1087篇 |
1996年 | 816篇 |
1995年 | 757篇 |
1994年 | 722篇 |
1993年 | 449篇 |
1992年 | 616篇 |
1991年 | 486篇 |
1990年 | 449篇 |
1989年 | 362篇 |
1988年 | 344篇 |
1987年 | 279篇 |
1986年 | 237篇 |
1985年 | 216篇 |
1984年 | 117篇 |
1983年 | 86篇 |
1982年 | 63篇 |
1981年 | 59篇 |
1980年 | 32篇 |
1979年 | 52篇 |
1978年 | 29篇 |
1977年 | 21篇 |
1976年 | 17篇 |
1975年 | 10篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
X Dong M He X Song B Lu Y Yang S Zhang N Zhao L Zhou Y Li X Zhu R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks. 相似文献
82.
This column contains the presidential address presented during the Third Annual Meeting of the American Association of Heart Failure Nurses on June 28, 2007, in San Diego, California, titled "Building the Foundation of Excellence in Heart Failure Nursing." 相似文献
83.
M Guillaume Wientjes Jenny H Zheng Leijun Hu Yuebo Gan Jessie L-S Au 《Clinical cancer research》2005,11(11):4204-4211
PURPOSE: The present study evaluated the tissue distribution and targeting advantage of intraprostatic chemotherapy. EXPERIMENTAL DESIGN: We studied the delivery and spatial distribution of a fluorescent drug, doxorubicin, in the prostate of beagle dogs, after intraprostatic or i.v. administration. Drug concentrations were measured using high-performance liquid chromatography and confocal fluorescence microscopy. RESULTS: I.v. and intraprostatic injections yielded qualitatively and quantitatively different doxorubicin distribution in the prostate. A relatively homogeneous distribution was found after i.v. administration, whereas intraprostatic injection yielded a highly heterogeneous distribution with >10-fold higher concentrations localized in a cone-shaped glandular lobule bound by fibromuscular stroma, compared with other parts of the prostate. Compared with i.v. injection, intraprostatic injection yielded, on average, approximately 100-fold higher tissue-to-plasma concentration ratio, ranging from 963-fold near the injection site to 19-fold in the contralateral half of the prostate. The drug distribution within the prostate further suggests an important role for acinar flow in intraprostatic drug transport. CONCLUSIONS: Intraprostatic administration represents a viable option to deliver high drug concentrations within the prostate. The results further suggest the fibromuscular stroma separating the prostatic lobules as a major barrier to drug transport and convective flow as an important drug transport mechanism in the prostate. 相似文献
84.
以曼氏血吸虫的虫卵和成虫免疫家兔后所产生的特异性抗体,可用以日本血吸虫虫卵、尾蚴和成虫为抗原分别进行的COP,CHR和ELACIEP测出,表明两种人体血吸虫存有显著的交叉抗原成分。应用此种血清交叉反应性,以检测抗异种人体血吸虫的抗体,似有效而可取的,可用以辅助诊断援外回国人员是否感染国外人体血吸虫病。 相似文献
85.
Bent H. Hellum Zhuohan Hu Odd Georg Nilsen 《Basic & clinical pharmacology & toxicology》2009,105(1):58-63
Abstract: The aim of this study was to evaluate in vitro the dose‐dependent induction potential of six commonly used trade herbal products on CYP2C19 and CYP2E1 metabolic activities in cultured human hepatocytes. S‐mephenytoin and chlorzoxazone were used as specific CYP substrates, respectively, and rifampicin was used as a positive induction control for both enzymes. The hepatocytes were exposed to herbal extracts in increasing and biological relevant concentrations for 72 hrs and CYP substrate metabolites were quantified by validated HPLC methodologies. The major findings were that St John's wort was the most potent CYP‐modulating herb, showing a dose‐dependent induction/inhibition of both CYP2C19 and CYP2E1, with induction at low dosages and inhibition at higher. Ginkgo biloba showed an induction/inhibition profile towards CYP2C19 which was similar but weaker than that observed for St John's wort. If cooperative mechanisms are involved is still an open question. Common sage induced CYP2C19 in a log‐linear dose‐dependent manner with increasing concentrations. Common valerian was a weak inducer of CYP2C19, while horse chestnut and cone flower were characterized as non‐inducers of CYP2C19. Only St John's wort showed an inductive effect towards CYP2E1. In addition to St John's wort, Gingko biloba and common sage should be considered as possible candidates for clinically relevant drug‐herb interactions with selected CYP2C19 substrates. 相似文献
86.
87.
Qiong Xu Junqi Ling Gary S P Cheung Yan Hu 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(4):e109-e113
OBJECTIVE: The aim of this study was to evaluate the sealing ability of 4 different obturation techniques by using a glucose leakage test. STUDY DESIGN: Eighty extracted single-rooted maxillary incisors were selected for the study. The teeth were decoronated and the root canals prepared using ProFile rotary instruments to an apical dimension of size 40 (0.06 taper). The specimens were then randomly divided into 4 experimental groups (n = 15) and filled with gutta-percha and sealer by using either cold lateral compaction, warm vertical compaction, Thermafil, or the E & Q Plus system. Another 10 teeth each served as the positive and negative controls. A glucose leakage model was used for quantitative evaluation of the coronal-to-apical microleakage at 24 hours, 1, 2, 3, 5, 8, and 12 weeks. RESULTS: No significant difference in the cumulative amount of leakage was found among the 4 groups at 24 hours and 1 week (Kruskal-Wallis test, P > .05). Lateral compaction showed significantly more leakage than the other 3 techniques at longer intervals (Mann-Whitney U test, P < .008). No significant difference was found between vertical compaction, Thermafil, and E & Q Plus at all observation times. CONCLUSIONS: Warm vertical compaction, Thermafil, and the E & Q Plus system showed a better sealing result than cold lateral compaction of gutta-percha at extended observation periods. The glucose leakage method used in this study was able to provide a nondestructive, quantitative, and long-term evaluation of the sealing ability of root canal fillings. 相似文献
88.
Gina Kearney MSN RN CS AHN-BC JeMe Cioppa-Mosca PT MBA Margaret G. E. Peterson Ph.D C. Ronald MacKenzie MD 《HSS journal》2007,3(2):198-201
In an outpatient rehabilitation setting, both patients’ use and therapists’ knowledge of complementary and alternative medicine
(CAM) varies widely. Based on this observation and a recognition of CAM as an emerging practice area for rehabilitation professionals,
it was felt that a thorough and consistent approach to the education and orientation of physical therapists to the world of
CAM and integrative care was needed. This special interest paper will describe one center’s approach, development, and use
of a unique and comprehensive training manual designed to provide both a structured and standardized approach for educating
physical therapists about CAM and related therapeutic modalities. This innovative teaching tool allows for multiple methods
of content delivery within a multidisciplinary format and can be used for those who practice currently or desire to practice
in an integrative care environment. 相似文献
89.
pH值对IFN-α2b、rIL-2、ADM合用维拉帕米对人肝癌细胞杀伤作用的影响 总被引:1,自引:0,他引:1
目的 观察培养液在 pH值为 6 .8、7.3、7.6条件下rIL - 2、IFN -α2b、ADM及合用维拉帕米对人肝癌细胞 74 0 4杀伤作用的影响。方法 MTT法于 96孔培养板上进行杀伤实验 ,测定培养液pH值分别为 6 .8、7.3、7.6状态下 ,rIL - 2、IFN -α2b、ADM、及与维拉帕米联合杀伤人肝癌细胞 70 4 0的差异。结果 pH值为 7.6状态下rIL - 2、IFN -α2b、ADM及合用维拉帕米杀伤效果最佳。pH值为 6 .8、7.3、7.6时 ,IFN -α2b都能增加ADM抗肿瘤作用 ,但pH值为 7.6时 ,IFN -α2b +ADM杀伤效果最佳。结论 在偏硷性环境下 ,rIL - 2、IFN -α2b、ADM及合用维拉帕米对肿瘤细胞杀伤效果最佳 相似文献
90.
目的 探讨贫困地区超声乳化联合小切口硬核白内障摘除联合PMMA人工晶状体植入手术的疗效。方法 对336例(336只眼)Ⅳ级以上核白内障行超声乳化联合小切口晶状体摘除联合PMMA人工晶状体植入术。结果 术后1天、3天视力在0.5以上分别为240只眼(71.4%)、265只眼(78.8%)。术中主要并发症为后囊破裂。术后主要并发症为角膜水肿、眼压升高。结论 超声乳化联合小切口晶状体摘除治疗Ⅳ级以上核白内障切口小,术后反应轻,散光小,并且视力恢复快,费用低。手术技巧的提高可避免或减少术中术后并发症。 相似文献