全文获取类型
收费全文 | 251664篇 |
免费 | 23784篇 |
国内免费 | 16879篇 |
专业分类
耳鼻咽喉 | 2010篇 |
儿科学 | 2846篇 |
妇产科学 | 2661篇 |
基础医学 | 34019篇 |
口腔科学 | 4337篇 |
临床医学 | 31848篇 |
内科学 | 35798篇 |
皮肤病学 | 2702篇 |
神经病学 | 12667篇 |
特种医学 | 8924篇 |
外国民族医学 | 136篇 |
外科学 | 24687篇 |
综合类 | 42851篇 |
现状与发展 | 59篇 |
一般理论 | 18篇 |
预防医学 | 17502篇 |
眼科学 | 6586篇 |
药学 | 27888篇 |
210篇 | |
中国医学 | 14522篇 |
肿瘤学 | 20056篇 |
出版年
2024年 | 952篇 |
2023年 | 3940篇 |
2022年 | 10191篇 |
2021年 | 12914篇 |
2020年 | 9524篇 |
2019年 | 8238篇 |
2018年 | 8673篇 |
2017年 | 7930篇 |
2016年 | 7569篇 |
2015年 | 11187篇 |
2014年 | 13852篇 |
2013年 | 12924篇 |
2012年 | 18435篇 |
2011年 | 19921篇 |
2010年 | 13398篇 |
2009年 | 10753篇 |
2008年 | 13335篇 |
2007年 | 13268篇 |
2006年 | 12438篇 |
2005年 | 11862篇 |
2004年 | 8538篇 |
2003年 | 8077篇 |
2002年 | 6938篇 |
2001年 | 5979篇 |
2000年 | 5620篇 |
1999年 | 5479篇 |
1998年 | 3566篇 |
1997年 | 3711篇 |
1996年 | 2722篇 |
1995年 | 2582篇 |
1994年 | 2282篇 |
1993年 | 1519篇 |
1992年 | 1915篇 |
1991年 | 1645篇 |
1990年 | 1430篇 |
1989年 | 1324篇 |
1988年 | 1148篇 |
1987年 | 987篇 |
1986年 | 908篇 |
1985年 | 704篇 |
1984年 | 499篇 |
1983年 | 415篇 |
1982年 | 330篇 |
1981年 | 297篇 |
1980年 | 242篇 |
1979年 | 250篇 |
1978年 | 192篇 |
1977年 | 211篇 |
1976年 | 191篇 |
1974年 | 157篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Fengxiu Ouyang Binyan Wang Lester M. Arguelles Xiping Xu Jianhua Yang Zhiping Li Liuliu Wang Xue Liu Genfu Tang Houxun Xing Craig Langman Xiaobin Wang 《Archives of osteoporosis》2007,2(1-2):29-43
Summary We prospectively examined bone growth patterns in 894 children aged 6–17 years at the baseline visit, with a 6-year follow-up.
Results show bone “tracking” over a six-year interval and sexual dimorphism of bone attained levels and timing of peak bone
growth. Our findings underscore childhood and adolescence as critical periods for building bone and developing gender differences.
Introduction Bone growth patterns were prospectively examined in 894 Chinese children (496 males), aged 6–17 yrs, from a population-based
twin cohort. Whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD) were measured by DEXA at
baseline and a 6-yr follow-up.
Methods Graphic smoothing plots and generalized estimating equations were used to model bone attained levels, growth, and “tracking”.
Results Attained levels of BMC and BA increased curvilinearly with age. Male attained levels were higher than females after age ∼15 yr,
but BMD was lower between 13–17 yrs (Tanner stage I to IV). In both genders, peak BMC and BMD growth lagged ∼2 yrs behind
peak BA growth, which lagged 2 yrs behind peak height growth. Peak bone growth occurred 1–3 yrs later in males. Over the 6-yr
follow-up, all bone measurements “tracked”, but “shifting” across ranks also occurred, and baseline tertile ranking influenced
bone growth. Females with early menarche had higher attained levels than females with late menarche at age 12–13 yrs.
Conclusion Our findings confirm and expand previous studies on peak bone growth conducted in Caucasian cohorts, particularly sexually
dimorphic and maturational effects. The significant “tracking” of bone measurements in this 6-yr follow-up study underscores
the importance that osteoporosis prevention should begin in childhood and adolescence.
Fengxiu Ouyang and Binyan Wang contributed equally to this article.
Source(s) of support: This study is supported in part by grant R01 HD049059, R01 HL0864619 and R01 AR045651 from the National
Institute of Health and by the Food Allergy Project. 相似文献
72.
腮腺良性和恶性多形性腺瘤的超声研究 总被引:1,自引:0,他引:1
目的研究腮腺良性和恶性多形性腺瘤的超声特点,为临床医师诊治提供有效依据。方法选取腮腺良性多形性腺瘤患者79例和恶性多形性腺瘤患者15例,对其肿块的大小、硬度、内部回声、彩色多普勒血流显像(CDFI)特点结合病理学诊断进行对照研究。结果恶性多形性腺瘤的声像图特点与良性多形性腺瘤相似,但其肿瘤相对较大,质地更硬,内部回声分布更紊乱。不同性质的肿瘤的大小和质地有显著性差异,(P<0.01)。结论多形性腺瘤的超声诊断主要依据二维图像之特点。当多形性腺瘤大于3.0 cm,硬度较硬,内部回声分布不均多提示恶性。 相似文献
73.
74.
Gelin Xu Xinfeng Liu Wusheng Zhu Qin Yin Renliang Zhang Xiaobing Fan 《Blood coagulation & fibrinolysis》2007,18(2):193-197
This study evaluated the safety and efficacy of batroxobin in treating hyperfibrinogenemia for secondary stroke prevention. Patients with ischemic stroke or transient ischemic attack (TIA) were measured for plasma fibrinogen levels. Selected participants had concomitant hyperfibrinogenemia (plasma fibrinogen > or = 3.0 g/l). Patients enrolled between 1 July 2003 and 31 December 2004 were treated with batroxobin; patients enrolled between 1 January 2002 and 30 June 2003 were treated without batroxobin. Batroxobin was administered intermittently via intravenous injection at 3-monthly intervals. Patients in both groups were followed for 1 year. Any cerebrovascular events and suspected adverse events were recorded. In total, 112 ischemic stroke/TIA patients with concomitant hyperfibrinogenemia were enrolled, 52 being treated with batroxobin and 60 without batroxobin. Six patients (11.5%) with batroxobin and 16 patients (26.7%) without batroxobin had recurrent cerebral ischemic events during follow-up. Stroke/TIA recurrence in patients without batroxobin was higher than that in patients with batroxobin (P < 0.05). Two patients with batroxobin and two patients without batroxobin developed hemorrhagic stroke during follow-up. There were five deaths (9.6%) in the batroxobin group, and seven deaths (11.7%) in the nonbatroxobin group during follow-up (P > 0.05). Intermittent intravenous injection of batroxobin can efficiently reduce the risk for stroke/TIA recurrence in patients with concomitant hyperfibrinogenemia. 相似文献
75.
M. Yu. Stepanichev M. L. Libe I. A. Chernyshevskaya A. G. Moiseenok N. V. Gulyaeva 《Neurochemical Journal》2007,1(3):244-248
Administration of cholinotoxin etylcholine aziridinium (AF64A) into the brain selectively induces nonrever-sible cholinergic deficit. Wistar rats were injected intracerebroventricularly bilaterally with AF64A at doses of 1–3 nmol/ventricle. 28 days later the number of neurons survived was counted in dorsolateral, intermediate and medial groups of cells of the medial septum. AF64A induced a decrease in neuronal density and expression of cholineacetyl transferase at all doses used as well as in all regions studied. Brain sections were also stained for NADPH-diaphorase representing neuronal NO-synthase. Effects of AF64A on NADPH-diaphorase expression depended on the region studied. The number of NADPH-diaphorase-positive cells increased in the medial cellular group where more cholineacetly transferase-positive cells survived. In contrast, decrease in NADPH-diaphorase expression in the dorsolateral group of cells coincided with low level of cholineacetyltransferase-po-sitive neurons. The data presented suggest that in the AF64A-dependent model of neurodegeneration NO may play a neuroprotective function. 相似文献
76.
在管理期刊工作的实践中,探讨如何提高期刊利用率的策略,根据馆情,利用现代科技手段为读者提供高质量的信息服务。 相似文献
77.
78.
现代医学200词——138.黏附分子 总被引:1,自引:0,他引:1
所谓黏附分子是指存在于细胞表面,参与细胞间或细胞与细胞外基质的粘附的分子群的总称。广义来说,纤维连结蛋白、层粘连蛋白、透明质酸等细胞外基质的构成成分也是由细胞分泌并存在于细胞表面,也可归入黏附分子的范畴。但狭义所指的黏附分子是指贯通细胞膜的糖蛋白或构成细胞膜的糖脂质。膜贯通型糖蛋白黏附分子按其构造特征可分为若干家族。在免疫系统中的黏附分子主要分为整合素家族、免疫球蛋白超家族、选择素家族、钙粘素家族、连接蛋白家族以及唾液粘蛋白家族等。 相似文献
79.
中风毒邪论是一种与传统中医中风病理有所不同的理论 ,在中风毒邪论指导下形成解毒通络方是较为理想的神经保护剂 ,可解决目前神经保护治疗的主要障碍 ,有望成为提高中医治疗中风急性期疗效的关键 相似文献
80.
近年来,内窥镜下手术在眼科的应用有了很大进展,并且逐渐展现出其创伤小、并发症少、直视下操作、安全有效的优点。眼内窥镜联合激光可应用于青光眼前房角手术、青光眼睫状体光凝术、周边部视网膜玻璃体手术等等;另外泪道内窥镜在泪器疾病中的应用、鼻内窥镜在鼻眼相关手术中的应用也有很大的发展。眼内窥镜的应用开创了眼科微创手术时代。本文就眼用内窥镜的基本工作原理、应用现状和发展前景进行综述。 相似文献