全文获取类型
收费全文 | 10021篇 |
免费 | 754篇 |
国内免费 | 227篇 |
专业分类
耳鼻咽喉 | 70篇 |
儿科学 | 166篇 |
妇产科学 | 235篇 |
基础医学 | 664篇 |
口腔科学 | 92篇 |
临床医学 | 1585篇 |
内科学 | 718篇 |
皮肤病学 | 48篇 |
神经病学 | 567篇 |
特种医学 | 151篇 |
外科学 | 991篇 |
综合类 | 2115篇 |
预防医学 | 1115篇 |
眼科学 | 65篇 |
药学 | 1443篇 |
38篇 | |
中国医学 | 669篇 |
肿瘤学 | 270篇 |
出版年
2024年 | 51篇 |
2023年 | 147篇 |
2022年 | 294篇 |
2021年 | 408篇 |
2020年 | 497篇 |
2019年 | 282篇 |
2018年 | 253篇 |
2017年 | 370篇 |
2016年 | 392篇 |
2015年 | 367篇 |
2014年 | 770篇 |
2013年 | 684篇 |
2012年 | 873篇 |
2011年 | 774篇 |
2010年 | 646篇 |
2009年 | 506篇 |
2008年 | 444篇 |
2007年 | 458篇 |
2006年 | 418篇 |
2005年 | 340篇 |
2004年 | 251篇 |
2003年 | 256篇 |
2002年 | 214篇 |
2001年 | 150篇 |
2000年 | 117篇 |
1999年 | 114篇 |
1998年 | 79篇 |
1997年 | 60篇 |
1996年 | 66篇 |
1995年 | 59篇 |
1994年 | 65篇 |
1993年 | 42篇 |
1992年 | 37篇 |
1991年 | 49篇 |
1990年 | 43篇 |
1989年 | 44篇 |
1988年 | 41篇 |
1987年 | 27篇 |
1986年 | 45篇 |
1985年 | 38篇 |
1984年 | 37篇 |
1983年 | 14篇 |
1982年 | 20篇 |
1981年 | 32篇 |
1980年 | 17篇 |
1979年 | 21篇 |
1978年 | 16篇 |
1977年 | 17篇 |
1976年 | 23篇 |
1973年 | 8篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
目的观察和研究敏感期内、末不同时限单眼斜视(monocularstrabismus,MS)和单眼剥夺(monoculardeprivation,MD)幼猫视皮质、外侧膝状体的脑源性神经营养因子(brainderivedneurotrophicfactor,BDNF)的可塑性变化。从形态学、分子神经生物学角度探讨不同时限MS和MD幼猫视 相似文献
32.
D. Schiffer M. T. Giordana A. Mauro G. Racagni F. Bruno S. Pezzotta P. Paoletti 《Acta neuropathologica》1980,49(2):117-122
Summary Experimental cerebral tumors have been induced by transplacental ENU. The morphologic study of the brains of treated rats revealed that cellular hyperplasias appear at the 30th day of extrauterine life in the paraventricular white matter, i.e., before the already known early neoplastic proliferations. Cytofluorimetric investigations failed to demonstrate differences between treated and control rats during the 1st month. On the contrary, adenylate cyclase activity is very high in that period. The duration of the latency period is discussed.This research was supported by Grants No. 79.00678.96 and No. 79.00664.96 of Progetto Finalizzato Control of Neoplastic Growth, Consiglio Nazionale delle Ricerche (C.N.R.), Rome 相似文献
33.
34.
A. F. Schärli 《Pediatric surgery international》1991,6(6):396-400
The emergence of surgery during the Renaissance marked the birth of surgery as a discipline based on clinical observation and improvement of technical skill. Some of the most experienced surgeons dealing with pediatric problems were Paré, Phaer, Würtz and, especially, Hildanus, who described more than 150 cases in children. Some minor malformations were curable, and some major anomalies were described for the first time. Renaissance surgeons had no explanations for the etiology of diseases and malformations. In many instances, the imaginatio was considered to be responsible. 相似文献
35.
目的 :了解高血压病史对体外循环下冠脉搭桥术后早期预后的影响。方法 :对高血压和非高血压行体外循环下冠脉搭桥术年龄大于60岁的冠心病患者65例术前和术后早期的临床资料进行分析。结果 :与非高血压患者相比 ,患高血压的病人冠脉搭桥术后心律失常的发生率增高 ,术后30min动脉氧分压与吸入氧浓度 (PaO2/FiO2)比值明显低下 ,机械通气时间明显延长 ,术后24h内胸腔引流量明显增加 ,术后大剂量多巴胺 (>10μg·kg-1·min -1)应用率及重症监护时间无显著性差异。结论 :高血压病史使患者冠脉搭桥术后早期肺功能下降、心律失常发生率增高、出血倾向增加 ,提示维持高血压患者围手术期血压的正常有利于改善患者预后 相似文献
36.
Postnatal development of NR1, NR2A and NR2B immunoreactivity in the visual cortex of the rat 总被引:4,自引:0,他引:4
N-Methyl-D-aspartate receptors (NMDARs) are critically involved in some types of synaptic plasticity. The NMDAR subunits NR1, NR2A and NR2B are developmentally regulated, and it has been proposed that developmental changes in their expression may underlie developmental changes in cortical plasticity. Age-dependent change in cortical plasticity is most commonly measured by the monocular deprivation effect, which occurs during a critical period between P22 and P50 in the rat. Although the development of NMDAR subunits has been studied from birth through the fourth postnatal week, there is only meager information from older ages when visual plasticity ends. We hypothesized that there will be significant age-dependent change in expression of NR1, NR2A or NR2B between P22, when the cortex is plastic, and P90, when it is not. We applied specific antibodies recognizing NR1, NR2A and NR2B to the primary visual cortex at P14, P22, P30, P45 and P90. We found age-dependent changes in NR1-IR that were negatively correlated with changes in NR2A-IR; these subunits are not regulated in unison. In contrast, NR2A-IR and NR2B-IR were positively correlated. NR2A-IR and NR2B-IR both passed through a developmental minimum around P45, then recovered to approximately their P22 level. NR1-IR passed through a maximum at P45. There were no significant differences between P22 and P90. These results do not support the simple hypothesis that the loss of plasticity corresponds to a simple transition from juvenile levels of NMDAR subunit proteins to new adult levels. On the other hand, the results do confirm the hypothesis that there are significant changes in processing of NMDAR proteins during the time that plasticity is lost. How these changes of IR relate to synaptic transmission and plasticity needs to be clarified. 相似文献
37.
胆囊切除术后残余胆囊结石56例诊治及预防 总被引:6,自引:0,他引:6
目的:探讨胆囊切除术后残余胆囊结石的诊治和预防方法,减低此并发症的发生率。方法:对56例残余胆囊结石再次手术的病例进行回顾性分析。56例中初次手术行经典胆囊切除术18例,小切口胆囊切除术16例,腹腔镜胆囊切除术22例;急诊手术30例,择期手术26例;初次手术在三级以下医院施行42例,在三级以上医院施行14例。结果:除1例因粘连严重并发门脉高压症,分离时引起大出血被迫终止手术外,55例再次手术成功,切除残留胆囊及结石后,症状均消失,疗效满意。结论:合理掌握胆囊切除术的手术时机、和术式,在术中解剖清楚胆囊管、肝总管、胆总管三管关系,然后距胆总管0.3~0.5cm切断结扎胆囊管,是预防残余胆囊结石的关键。 相似文献
38.
39.
目的 探讨硬膜外腔阻滞复合全麻与肋间神经阻滞复合全麻对开胸手术患者早期恢复质量的影响。方法 选取行开胸手术患者76例,按随机数表法分为两组,硬膜外阻滞复合全麻组(E组)、肋间神经阻滞复合全麻组(C组),每组38例。E组行硬膜外穿刺置管,术中0.2%罗哌卡因维持;C组行切口及上下肋间神经阻滞,两组全麻诱导及维持一致。采用术后恢复质量量表(quality of recovery QoR-40)对患者进行术前1d、术后3d恢复质量评分;采用视觉模拟评分法(visual analogue scale, VAS)对两组患者进行拔管后4 h、8 h、12 h、24 h安静和活动后的VAS评分;同时记录患者首次下床活动时间及住院时间。结果 E组在术后3dQoR-40各项评分均高于C组,差异有统计学意义(P <0.05);E组静息和运动状态下术后各时间点VAS评分均低于C组,差异有统计学意义(P <0.05);E组首次下床活动时间较早,住院时间较C组减少,差异有统计学意义(P <0.05)。结论 硬膜外阻滞复合全身麻醉用于开胸手术患者,不仅镇痛效果良好,还能明显提高术后早期恢复质量,... 相似文献
40.
慢性肺源性心脏病急性加重期98例糖代谢异常分析 总被引:2,自引:0,他引:2
目的:探讨慢性肺源性心脏病(肺心病)急性加重期糖代谢异常变化及其原因。方法:选择无糖尿病病史的肺心病急性加重期患者98例进行糖耐量试验(OGTT),并同健康对照组相比较。结果:肺心病患者血糖峰值为(8.46±0.61)mmol/L,显著高于对照组(7.59±0.50)mmol/L(P<0.01);平均高峰时间为(0.60±0.18)小时,而对照组为(0.75±0.24)小时,2组差异有显著性意义(P<0.05)。结论:肺心病患者糖代谢异常,可能与胰岛素分泌不足和胰岛素灭活障碍有关。 相似文献