全文获取类型
收费全文 | 409892篇 |
免费 | 26795篇 |
国内免费 | 9094篇 |
专业分类
耳鼻咽喉 | 6816篇 |
儿科学 | 10361篇 |
妇产科学 | 7960篇 |
基础医学 | 29205篇 |
口腔科学 | 10882篇 |
临床医学 | 43858篇 |
内科学 | 49299篇 |
皮肤病学 | 5231篇 |
神经病学 | 21675篇 |
特种医学 | 9022篇 |
外国民族医学 | 50篇 |
外科学 | 61075篇 |
综合类 | 59991篇 |
现状与发展 | 18篇 |
一般理论 | 31篇 |
预防医学 | 37376篇 |
眼科学 | 9681篇 |
药学 | 32795篇 |
532篇 | |
中国医学 | 31233篇 |
肿瘤学 | 18690篇 |
出版年
2024年 | 1344篇 |
2023年 | 7295篇 |
2022年 | 12600篇 |
2021年 | 17028篇 |
2020年 | 16071篇 |
2019年 | 21125篇 |
2018年 | 18850篇 |
2017年 | 15356篇 |
2016年 | 12873篇 |
2015年 | 12240篇 |
2014年 | 25007篇 |
2013年 | 26137篇 |
2012年 | 21983篇 |
2011年 | 23753篇 |
2010年 | 19068篇 |
2009年 | 17627篇 |
2008年 | 17128篇 |
2007年 | 17571篇 |
2006年 | 15321篇 |
2005年 | 13359篇 |
2004年 | 10978篇 |
2003年 | 9522篇 |
2002年 | 7482篇 |
2001年 | 6781篇 |
2000年 | 5656篇 |
1999年 | 4955篇 |
1998年 | 4049篇 |
1997年 | 3864篇 |
1996年 | 3246篇 |
1995年 | 3035篇 |
1994年 | 2893篇 |
1993年 | 2302篇 |
1992年 | 2287篇 |
1991年 | 1996篇 |
1990年 | 1724篇 |
1989年 | 1556篇 |
1988年 | 1483篇 |
1987年 | 1304篇 |
1985年 | 3946篇 |
1984年 | 4943篇 |
1983年 | 3435篇 |
1982年 | 3900篇 |
1981年 | 3636篇 |
1980年 | 3228篇 |
1979年 | 2945篇 |
1978年 | 2561篇 |
1977年 | 1936篇 |
1976年 | 2169篇 |
1975年 | 1650篇 |
1974年 | 1435篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
低温体外循环下手术治疗主动窦瘤破裂16例,采用右房切口1例,右室流出道切口11例,窦瘤破入腔和主动脉根部双切口4例。单纯窦瘤破口修补2例;双头垫片针窦瘤基部与空间隔踬同并列间断褥式缝合修补3例; 相似文献
992.
993.
Lung function, smoking, age and mortality data in 158 adult severe alpha1-antitrypsin deficient, PiZZ individuals, followed from 1963 to 1982 were analyzed. Low initial FEV1 value was significantly associated with increased mortality (p < 0.005). A 3 yr mortality rate of 40% was found in individuals whose initial FEV1 values were less than 30% of that predicted. In contrast, the corresponding 3-yr mortality among those whose initial FEV1 values were between 30 and 65% of that predicted was only 7%. Smokers were found to have significantly lower FEV1 levels (p = 0.008) and higher mortality (p < 0.005) than non-smokers. The difference between current and ex-smokers in mortality and FEV1 level were not statistically significant (p = 0.9 and p>0.25, respectively). Cross-sectional analysis of the initial FEV1 values indicated a significant decline (p < 0.005) of FEV1 with increasing age. This decline was greater among smokers than non-smokers. Longitudinal analysis of FEV1 rates of decline in 80 cases with follow-up FEV1 measurements failed to detect any significant differences between smokers and non-smokers, but was performed late in the disease process. The application of these results to the planning of studies on replacement therapy, smoking intervention strategy and longitudinal follow-up is discussed. 相似文献
994.
二乙基二硫代氨基甲酸钠驱镍作用的实验研究 总被引:1,自引:0,他引:1
本文用大鼠研究了带-SH基的二乙基二硫代氨基甲酸钠(Dithiocarb,简称Na-DDC或称铜试剂)和不带-SH基的新螯合剂(H-73-10)的驱镍作用。结果表明,Na-DDC对羰基镍(Ni(CO)_4〕的驱镍作用明显优于H-73-10;与此相反,H-73-10对硝酸镍〔Ni(NO_3)_2〕染毒大鼠的驱镍作用却明显优于Na-DDC。 相似文献
995.
Hinrich Staecker Stefan Dazert Brigitte Malgrange Philippe P. Lefebvre Allen F. Ryan Thomas R. Van de water 《International journal of developmental neuroscience》1997,15(4-5)
To determine if transforming growth factor alpha (TGFα) pretreatment protects hair cells from aminoglycoside induced injury by modifying their intracellular calcium concentration, we assayed hair cell calcium levels in organ of Corti explants both before and after aminoglycoside (i.e. neomycin, 10−3M) exposure either with or without growth factor pretreatment. After TGFα (500ng/ml) treatment, the intracellular calcium level of hair cells showed a five-fold increase as compared to the levels observed in the hair cells of control cultures. After ototoxin exposure, calcium levels in hair cells of control explants showed an increase relative to their baseline levels, while in the presence of growth factors pretreatment, hair cells showed a relative reduction in calcium levels. Pretreatment of organ of Corti explants afforded significant protection of hair cell stereocilia bundle morphology from ototoxic damage when compared to explants exposed to ototoxin alone. This study correlates a rise in hair cell calcium levels with the otoprotection of hair cells by TGFα in organ of Corti explants. 相似文献
996.
Summary Human fibrin glue (Tissucol) is a plasma-derived compound endowed with adhesive and hemostatic properties and possessing a specific local anti-infection function mediated through activation of nonspecific immunity elements. The aim of this study is to show that in patients who have undergone prolonged reconstructive plastic surgery following cancer resection, Tissucol decreases infectious complications as compared to a control group. Between June 1985 and February 1988, 51 subjects were treated with fibrin glue during reconstruction operations. Analysis of the results showed that Tissucol produced a statistically significant reduction both of immediate complications, such as inflammation and partial separation of the surgical wound, and of delayed complications, such as scar hypertrophy and cutaneous fistulae. In conclusion, patients treated with Tissucol showed a better quality of surgical wound, a more rapid postoperative functional recovery and consequently a decrease in the duration of hospitalization. 相似文献
997.
杨群 《中国实用美容整形外科杂志》1996,(6)
眼袋整形术的并发症主要包括下睑外翻、下睑睫毛外翻、睑球分离、泪小点外翻、眼鼻沟畸形及眶下睑沟凹陷畸形等。皮肤眼轮匝肌及眶隔脂肪切除过多是造成上述并发症的主要原因,另外,手术中失误或操作粗糙也可造成诸如复视、泪小管撕裂甚至球后血肿等严重并发症。防止下睑外翻的发生,主要在于如何测定松弛皮肤的方法,这要把眼球活动、面部肌肉活动以及重力对面部的影响等诸因素进行综合考虑,正确估算出皮肤的切除量,才能有效防止睑外翻的发生。对于轻度外翻可采用热敷、按摩等保守治疗,对于重度睑外翻据不同情况分别采用,眼轮匝肌提紧术,睑板部分切除、结膜囊缩小术及下睑皮肤移植术加以矫正。对于眶下区凹陷及眼鼻沟畸形,术中就应注意避免,特别是要控制好眶脂的切除量,一旦发生可采用脂肪或筋膜脂肪充填,也可行眼轮匝肌提紧加以矫正。总之,在眼袋整形术中避免去除过多的组织,无论是皮肤,还是眶隔脂肪,都可有效防止并发症的发生。 相似文献
998.
Neural responses in the dorsal motor nucleus of the vagus (DMV) to topical administrations of sodium and portal infusions of hypertonic saline were investigated electrophysiologically by using multibarrel electrodes in anesthetized rats. Of 102 neurons that showed antidromic response to electrical stimulation of the ventral gastric vagus or the accessory celiac vagus, 51 neurons increased and 13 neurons decreased their discharge rates in response to the electrophoretic administration of sodium. The other 38 neurons did not respond to this stimulation. The portal infusion of hypertonic saline elicited neural responses of some DMV neurons whose axons are involved into either the ventral gastric or the accessory celiac vagus. Further, effects of the topical administration and the portal infusion of hypertonic saline were examined on 33 neurons. Typical response was characterized by an increase in discharge rate responding to both of the portal infusion and the topical administration. In conclusion, the DMV neurons receiving the afferent inputs from hepatoportal osmoreceptors may have an enteroceptor function detecting the change in osmotic pressure of their environment. 相似文献
999.
对全国部分城乡家鼠鼠情监测三年结果的分析表明:城乡家鼠组成均以三大家鼠(褐家鼠、小家鼠、黄胸鼠)为主,其次为食虫目臭鼩鼱~#和黑线姬鼠。五种主要鼠种在家鼠组成中的数量比基本稳定,但三年中城乡少数鼠种间的顺位有所变化。监测结果亦表明,五种主要鼠种的地区分布是:褐家鼠、小家鼠遍布所有监测的省、市、区,同以往文献中遍布全国的说法一致;黄胸鼠分布于黄河以南;食虫目中的臭鼩鼱分布于华中区以南的广大地区。这在以往文献中均已有记载,但以往文献有关黄胸鼠和臭鼩鼱分布的其他说法,则被证实为不确切的。黑线姬鼠的分布范围已超过以往文献中关于分布于东北、华北及长江流域的说法,但以往文献中关于该鼠种遍及全国的说法是否正确,则有待进一步证实。 相似文献
1000.
R. P. DURAND J. H. LEVINE L. S. LICHTENSTEIN G. A. FLEMING G. R. ROSS 《Medical education》1988,22(4):335-341
Twenty senior teachers were asked to rank, in order of influence, the seven clinical and five personal characteristics used to grade third-year medicine clerks. Seventeen perceived themselves to be more influenced by clinical characteristics when assigning grades. Independently, the actual ratings completed over a 3-year period by these same teachers were analysed to measure the congruency between their perceived and actual grading behaviour. When actually rating students only nine raters were more influenced by clinical characteristics and just one half of the teachers displayed a congruency between their perceived and actual rating behaviour. The implications of these findings are discussed. 相似文献