全文获取类型
收费全文 | 253953篇 |
免费 | 23589篇 |
国内免费 | 16885篇 |
专业分类
耳鼻咽喉 | 2236篇 |
儿科学 | 2838篇 |
妇产科学 | 3491篇 |
基础医学 | 29695篇 |
口腔科学 | 4366篇 |
临床医学 | 34947篇 |
内科学 | 37750篇 |
皮肤病学 | 2773篇 |
神经病学 | 14322篇 |
特种医学 | 9207篇 |
外国民族医学 | 140篇 |
外科学 | 24904篇 |
综合类 | 40747篇 |
现状与发展 | 70篇 |
一般理论 | 44篇 |
预防医学 | 16664篇 |
眼科学 | 7568篇 |
药学 | 26486篇 |
246篇 | |
中国医学 | 14687篇 |
肿瘤学 | 21246篇 |
出版年
2024年 | 848篇 |
2023年 | 4000篇 |
2022年 | 10433篇 |
2021年 | 13165篇 |
2020年 | 9930篇 |
2019年 | 8649篇 |
2018年 | 9204篇 |
2017年 | 8271篇 |
2016年 | 7706篇 |
2015年 | 11662篇 |
2014年 | 14279篇 |
2013年 | 12639篇 |
2012年 | 18909篇 |
2011年 | 20922篇 |
2010年 | 12730篇 |
2009年 | 10069篇 |
2008年 | 13443篇 |
2007年 | 13263篇 |
2006年 | 13160篇 |
2005年 | 13055篇 |
2004年 | 8300篇 |
2003年 | 7813篇 |
2002年 | 6486篇 |
2001年 | 5314篇 |
2000年 | 5667篇 |
1999年 | 5902篇 |
1998年 | 3762篇 |
1997年 | 3667篇 |
1996年 | 2936篇 |
1995年 | 2713篇 |
1994年 | 2257篇 |
1993年 | 1460篇 |
1992年 | 1986篇 |
1991年 | 1691篇 |
1990年 | 1366篇 |
1989年 | 1146篇 |
1988年 | 1065篇 |
1987年 | 938篇 |
1986年 | 786篇 |
1985年 | 574篇 |
1984年 | 393篇 |
1983年 | 301篇 |
1982年 | 218篇 |
1981年 | 191篇 |
1980年 | 149篇 |
1979年 | 165篇 |
1978年 | 81篇 |
1977年 | 84篇 |
1975年 | 71篇 |
1974年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Lianjun Lu Jinling Wang Jianhua Qiu Weiguo Huang Shunli Liu Shengxi Wu 《中华耳鼻咽喉科杂志》2002,37(6):428-431
OBJECTIVE: To examine the distribution of rat facial motoneurons contributing different branches under normal situation and when nerve reinnervation occurred following facial nerve axotomy. METHODS: The normal distribution of motoneurons innervated both buccal and marginal mandibular branches and its reorganization after facial nerve reinnervation was observed using retrograde labeling with fluorescein. RESULTS: Under normal situation, the motoneurons contributing buccall and marginal mandibular branches were primarily distributed in the intermedial and lateral subnucleus in facial nucleus and almost completely overlapped. The two types labeled neurons organized closely, but there were no double-labeled neurons. Although the motoneurons contributing buccall and marginal mandibular branches were primarily overlapped 4 month post-anastomosis, the number of the labeled neurons obviously decreased and the organization got more scattered. There were 10% of buccall branches, 5% of marginal mandibular motoneurons in the dorsal subnuleus, 1% of buccall and 4% of marginal mandibular in dorsal ventral and medial subnucleus. The distribution pattern of the motoneurons 6 month post-anastomosis was similar to that of 4 month post-anastomosis, but the number of the labeled neurons increased, and there were 1%-2% double-labeled neurons. CONCLUSION: The distribution pattern of motoneurons innervated both buccal and marginal mandibular branches indicates that it should exist wide-spread communicating branches, and its reorganization after facial nerve reinnervation suggests that misdirected regeneration occurs among motoneurons innervating different branches. 相似文献
72.
The promoting effect of the Chinese medicinal herb, Wikstroemia chamaedaphne and Tung oil extracts (WC and HHPA) on carcinoma of uterine cervix induced by HSV-2 or MCA in mice was studied. The results showed that WC and HHPA extracts were not carcinogenic themselves. After carcinogen HSV-2 and MCA treatment, WC and HHPA were added separately. The inducing rates by HSV-2 increased from 7.4% to 21.1% and 26.3%, those by MCA increased from 56.5% to 82.8% and 84.4%. There was a significant difference between the combined groups and groups with HSV-2 or MCA only. The experimental results suggest that these two kinds of extracts play a promoting effect on carcinogenesis. The relation between the carcinogenesis of uterine cervix or nasopharynx and WC or HHPA extracts is discussed. 相似文献
73.
74.
75.
Liesbeth Vandenput Fernand Labrie Dan Mellstr?m Charlotte Swanson Thomas Knutsson Ralph Peeker Osten Ljunggren Eric Orwoll Anna L Eriksson Jan-Erik Damber Claes Ohlsson 《Journal of bone and mineral research》2007,22(2):220-227
Androgens are important regulators of bone and prostate health in elderly men. The role of serum levels of glucuronidated androgen metabolites as predictors of BMD and prostate volume in men is unclear. We show that specific glucuronidated androgen metabolites predict BMD and prostate volume in elderly men. INTRODUCTION: Androgens are important regulators of bone and prostate health in elderly men. Local synthesis and degradation of androgens are likely to be important parameters of biological action of androgens in androgen-responsive tissues. The aim of this study was to determine the role of serum levels of glucuronidated androgen metabolites as predictors of BMD and prostate volume in elderly men. MATERIALS AND METHODS: A subsample of the population-based Swedish part of the MrOS study (n = 631, average age = 75.9 years) was investigated. Bone parameters were measured using DXA. Serum levels of total testosterone (T) and dihydrotestosterone (DHT) were measured by gas chromatography/mass spectroscopy (GC-MS); androstane-3alpha,17beta-diol-3glucuronide (3G) and androstane-3alpha,17beta-diol-17glucuronide (17G) were measured by liquid chromatography/mass spectroscopy. Prostate volume (n = 159) was measured by transrectal ultrasound. RESULTS: The general pattern is that two of the glucuronidated androgen metabolites, namely 17G and 3G, are stronger positive predictors of BMD than the bioactive androgens (T and DHT). In addition, 17G is a clear positive predictor of prostate volume, explaining 4.5% of the variance in prostate volume, whereas the bioactive androgens do not display any association with prostate volume. CONCLUSIONS: Serum levels of specific glucuronidated androgen metabolites predict BMD and prostate volume in elderly men. Future studies should determine if the glucuronidated androgen metabolites also reflect other biological correlates of androgenic activity, including prostate cancer, and if low levels might be a marker of general androgen deficiency in men. 相似文献
76.
77.
复合式听写比听力选择题更强调语言综合运用能力。全面打好语言基本功是提高听写能力的重要途径。但听写训练具有自身的科学性和技巧性,多练加巧练可以取得事半功倍的成效。 相似文献
78.
79.
刘伯宁 《中国实用妇科与产科杂志》2006,22(5):338-339
卵巢肿瘤合并副肿瘤性综合征(ovarian tumor associated with paraneoplastic syndrome)并非罕见,但由于此综合征往往先于肿瘤出现,而因肿瘤病灶小或隐匿不易被发现,常被临床医师所忽略,导致肿瘤未能得到及时诊断和治疗."paraneoplastic syndrome"一词有译为副肿瘤性综合征、副肿瘤综合征、副癌综合征、肿瘤外综合征者.此综合征为肿瘤患者的一种复合症状,该症状不能用肿瘤本身或肿瘤转移来解释.现按主要受累系统的几种综合征简介如下,以加强临床医师对卵巢肿瘤合并副肿瘤性综合征特点的认识,减少误诊、误治。 相似文献
80.
Chuan-Bin Guo Nian-Hui Cui Guang-Yan Yu Ding-Xin Liu Shu-Cong Meng Qing Song 《Journal of oral and maxillofacial surgery》2003,61(8):909-912
PURPOSES: Inhibition of cerulenin on the endogenous fatty acid synthetic activities of oral squamous cell carcinoma (OSCC) and normal oral mucosa was assayed. METHODS: Squamous cell carcinoma and normal oral mucosa were collected fresh from surgical specimens. The collected tissues were minced in RPMI 1640 and divided into 3 groups: cerulenin treated, dimethylsulfoxide treated, and control. The tissues were incubated in [1(2)-(14)C]acetic acid, sodium salt for the last 2.5 hours of the treatment at 37 degrees C in 5% CO(2). After labeling, total lipids were extracted and counted for (14)C by scintillation counting. RESULTS: Endogenous fatty acid synthetic activities of oral squamous cell caranoma in the cerulenin-treated group decreased by 19% at 1 hour, 64% at 2 hours, and 87% at 4 hours; remained nearly unchanged in the dimethylsulfoxide-treated group; and increased slightly in the control group. The oral mucosa tissues were only mildly affected by cerulenin in fatty acid synthesis. CONCLUSIONS: Cerulenin significantly inhibits fatty acid synthetic activity in squamous cell carcinoma and only mildly affected the oral mucosa, indicating that the fatty acid synthetic pathway may be exploited as a target for developing anticancer drugs. 相似文献