全文获取类型
收费全文 | 348040篇 |
免费 | 31551篇 |
国内免费 | 24491篇 |
专业分类
耳鼻咽喉 | 3263篇 |
儿科学 | 3854篇 |
妇产科学 | 5318篇 |
基础医学 | 42044篇 |
口腔科学 | 5868篇 |
临床医学 | 47954篇 |
内科学 | 52576篇 |
皮肤病学 | 3363篇 |
神经病学 | 19424篇 |
特种医学 | 12819篇 |
外国民族医学 | 221篇 |
外科学 | 36123篇 |
综合类 | 54744篇 |
现状与发展 | 81篇 |
一般理论 | 22篇 |
预防医学 | 21787篇 |
眼科学 | 9953篇 |
药学 | 35374篇 |
361篇 | |
中国医学 | 19284篇 |
肿瘤学 | 29649篇 |
出版年
2024年 | 1131篇 |
2023年 | 5432篇 |
2022年 | 14050篇 |
2021年 | 17705篇 |
2020年 | 13071篇 |
2019年 | 11661篇 |
2018年 | 12246篇 |
2017年 | 10775篇 |
2016年 | 10116篇 |
2015年 | 15564篇 |
2014年 | 19234篇 |
2013年 | 16976篇 |
2012年 | 24938篇 |
2011年 | 27961篇 |
2010年 | 17467篇 |
2009年 | 13506篇 |
2008年 | 18430篇 |
2007年 | 18317篇 |
2006年 | 18213篇 |
2005年 | 17776篇 |
2004年 | 11377篇 |
2003年 | 10455篇 |
2002年 | 9059篇 |
2001年 | 7934篇 |
2000年 | 8654篇 |
1999年 | 9299篇 |
1998年 | 5593篇 |
1997年 | 5639篇 |
1996年 | 4437篇 |
1995年 | 4017篇 |
1994年 | 3305篇 |
1993年 | 2146篇 |
1992年 | 2927篇 |
1991年 | 2510篇 |
1990年 | 2201篇 |
1989年 | 1931篇 |
1988年 | 1637篇 |
1987年 | 1414篇 |
1986年 | 1156篇 |
1985年 | 949篇 |
1984年 | 550篇 |
1983年 | 393篇 |
1982年 | 253篇 |
1981年 | 248篇 |
1980年 | 206篇 |
1979年 | 237篇 |
1978年 | 95篇 |
1977年 | 99篇 |
1974年 | 110篇 |
1973年 | 89篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
The firing rate of locus coeruleus (LC) neurons in rat brain slices was increased reversibly by agents that either elevate intracellular levels of adenosine 3',5'-cyclic monophosphate (cAMP) or mimic its actions (e.g., forskolin, and activator of adenylate cyclase, 8-Br-cAMP, a membrane permeable analog of cAMP, and Ro20-1724, a preferential inhibitor of cAMP-phosphodiesterase). Intracellular recordings showed that 8-Br-cAMP and forskolin induce a depolarization of LC neurons, accompanied by a decrease in input resistance. The 8-Br-cAMP- and forskolin-elicited depolarization persisted in the presence of cobalt, a calcium channel blocker. Steady-state current-voltage curves revealed that in the voltage range of -50 to -120 mV, 8-Br-cAMP and forskolin induced an inward current, which did not reverse at the potassium equilibrium potential and could not be blocked by tetrodotoxin. Partial replacement of sodium with Tris or choline markedly reduced the depolarization elicited by 8-Br-cAMP. We conclude that 8-Br-cAMP and forskolin act through a common mechanism to increase the firing rate of locus coeruleus neurons by inducing a cAMP-activated inward current, carried out at least in part by sodium ions. 相似文献
82.
The interaction between the activator agents batrachotoxin and veratridine and the gating processes of neuronal sodium channels 总被引:7,自引:0,他引:7
The depolarization of frog sciatic nerves by the Na channel-activating toxins, batrachotoxin and veratridine, was studied using the sucrose-gap technique. To study the interaction between the activators and the gating processes of Na channels, we measured the depolarizations of unstimulated nerves, of nerves during repetitive stimulation, and of nerves whose Na channel inactivation process had been pharmacologically modified. Stimulation enhanced the rates of depolarization by the activators but did not effect the steady state depolarization values. Of the three inhibitors of Na channel inactivation that were tested (Leiurus alpha-scorpion toxin, chloramine T, and Ni2+), only Leiurus toxin enhanced the potencies of the activators. Neither chloramine T nor Ni2+ had any effect on the steady state level of depolarization produced by either activator. Both chloramine T and Ni2+, however, enhanced the rate of batrachotoxin action, although neither affected the rate of veratridine action. Leiurus toxin also potentiated the effects of the activators in chloramine T-treated nerves. We tested the interaction between the Na channel activators and a class of agents, local anesthetics, that stabilize a non-conducting state of the Na channel. The presence of lidocaine inhibited the depolarization produced by addition of either activator, although the addition of lidocaine subsequent to the development of batrachotoxin-induced depolarization produced repolarization very weakly and slowly. We also found that the lidocaine homologue, RAC 109I, was about 3 times as potent as its stereoisomer, RAC 109II, in its ability both to reduce the compound action potential amplitude and to inhibit the veratridine-induced depolarization. 相似文献
83.
提壶揭盖法治疗前列腺增生症82例 总被引:5,自引:0,他引:5
笔者自1995年以来,宗提壶揭盖法,用补中益气汤加减治疗前列腺增生82例疗效满意,报告如下。 相似文献
84.
我院护士工作评估体系及其应用 总被引:4,自引:0,他引:4
目的应用护士工作评估体系,激励护士不断自我完善.方法以自我评估、面对面交流、同事间评估、设立目标和建立护士档案为主要内容的评估.一般为每年1次.结果每年护士评估的覆盖率为100%.提供了上下级面对面交流的机会,每名护士都熟悉评估的程序并自觉参与.结论护士评估体系是护理管理的重要组成部分,它使管理者有机会关注到每名护士的成长需要及成长目标,指导我们能动地利用人力--这一最宝贵的资源. 相似文献
85.
86.
87.
OBJECTIVE: To study the cellular expression of CD45RO, CD20, CD68 and proliferating cell nuclear antigen (PCNA) in nasal polyps. METHODS: Nasal polyp tissues from 50 patients were evaluated for cellular expression of CD45RO, CD20, CD68 and PCNA using immunohistochemistry SP by counting the average number in 5 chosen high-power fields, Histopathological observations were combined with HE. Analyses were performed on SPSS10.0. RESULTS: CD68+ cells were expressed more in nasal polyps dominated by eosinophils than by neutrophils(P < 0.05). There was no difference between CD45RO and CD20, but both of them had negative correlation(P = 0.05). Significant correlation was found between CD68+ cells and eosinophils or PCNA positive cells on epithelium. PCNA positive cells on epithelium had significant correlation on fibroblast (P < 0.05). CONCLUSION: Inflammatory cell infiltration (eosinophilia CD45RO, CD20, CD68) and cell proliferating in epithelium cells, glandular cell and fibroblast are strongly correlated with formation of nasal polyps. The nasal polyps are not only characteristic of eosinophilia but also by lymphocytes dominated by CD45RO and CD68 positive cells. CD68 may be stem cell of nasal polyp. 相似文献
88.
89.
Ting-Kai Leung Chien-Jui Cheng Chi-Ming Lee Li-Kuo Shen Hung-Jung Wang Ya-Yen Chen 《中华医学杂志(英文版)》2005,118(17):1493-1496
The current report focuses on two patients of the same age who presented similar appearances on initial anteroposterior chest images. Follow-up images showed superoanterior and superoposterior mediastinal lesions. The first patient with noninvasive cystic thymoma was suspected before surgery, while the pathologic diagnosis was intrathoracic phrenic nerve schwannoma. The second patient was with an asymmetric, dumbbell-shaped paravertebral tumor over T3 and T4 on the left side. The preoperative… 相似文献
90.
文章编号:1009-6493(2006)12C-3352-02麻醉药品的管理是医院管理工作的一项重要任务,如果管理有方,使用得当,可以治病;如果失之管理,使用不当,危害生命健康及社会治安。2005年8月3日,国务院颁布了《麻醉药品和精神药品管理条例》以来我院采取了各种有效的相关措施,保证了麻醉药品的合理使用,取得了良好的社会效益。现将我院严格管理麻醉药品的方法介绍如下。1严格建卡要管理好麻醉药品,首先要严格建卡,建卡时要手续齐全。1.1户口本病人的户口要在建卡医院管辖区内,如超出所管辖区,应有三级甲等医院的证明或肿瘤专病医院的证明及病历。1.2病… 相似文献