全文获取类型
收费全文 | 68874篇 |
免费 | 5535篇 |
国内免费 | 2172篇 |
专业分类
耳鼻咽喉 | 472篇 |
儿科学 | 3074篇 |
妇产科学 | 875篇 |
基础医学 | 9257篇 |
口腔科学 | 810篇 |
临床医学 | 6718篇 |
内科学 | 4679篇 |
皮肤病学 | 132篇 |
神经病学 | 18353篇 |
特种医学 | 3179篇 |
外国民族医学 | 5篇 |
外科学 | 3280篇 |
综合类 | 8058篇 |
现状与发展 | 6篇 |
一般理论 | 5篇 |
预防医学 | 6302篇 |
眼科学 | 544篇 |
药学 | 5904篇 |
31篇 | |
中国医学 | 2043篇 |
肿瘤学 | 2854篇 |
出版年
2024年 | 164篇 |
2023年 | 973篇 |
2022年 | 1596篇 |
2021年 | 2543篇 |
2020年 | 2467篇 |
2019年 | 2236篇 |
2018年 | 2051篇 |
2017年 | 2293篇 |
2016年 | 2398篇 |
2015年 | 2380篇 |
2014年 | 3762篇 |
2013年 | 5170篇 |
2012年 | 3624篇 |
2011年 | 3787篇 |
2010年 | 3390篇 |
2009年 | 3171篇 |
2008年 | 3349篇 |
2007年 | 3394篇 |
2006年 | 3124篇 |
2005年 | 2765篇 |
2004年 | 2267篇 |
2003年 | 2080篇 |
2002年 | 1721篇 |
2001年 | 1533篇 |
2000年 | 1250篇 |
1999年 | 1154篇 |
1998年 | 1093篇 |
1997年 | 1103篇 |
1996年 | 930篇 |
1995年 | 823篇 |
1994年 | 788篇 |
1993年 | 610篇 |
1992年 | 618篇 |
1991年 | 509篇 |
1990年 | 497篇 |
1989年 | 425篇 |
1988年 | 423篇 |
1987年 | 361篇 |
1986年 | 453篇 |
1985年 | 540篇 |
1984年 | 538篇 |
1983年 | 345篇 |
1982年 | 388篇 |
1981年 | 378篇 |
1980年 | 331篇 |
1979年 | 191篇 |
1978年 | 147篇 |
1977年 | 108篇 |
1976年 | 104篇 |
1975年 | 54篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Diseases like rotavirus afflict both upper- and lower-income countries, but most serious illnesses and deaths occur among the latter. It is a vital public health issue that vaccines for these types of global diseases can recover research and development (R&D) costs from high-priced markets quickly so that manufacturers can offer affordable prices to lower-income nations. Cost recovery depends on how high R&D costs are, and this study attempts to replace high, unverified estimates with lower, more verifiable estimates for two new vaccines, RotaTeq (Merck) and Rotarix (GlaxoSmithKline or GSK), based on detailed searches of public information and follow-up interviews with senior informants. We also offer a new perspective on “cost of capital” as a claim for recovery from public bodies. Our estimates suggest that companies can recover all fixed costs quickly from affluent markets and thus can offer these vaccines to lower-income countries at prices they can afford. Better vaccines are a shared project between companies and public health agencies; greater transparency and consistency in reporting of R&D costs is needed so that fair prices can be established. 相似文献
102.
BACKGROUND: Studies have shown that alcoholics have smaller brain volumes than non-alcoholic cohorts, but an effect of family history (FH) of heavy drinking on brain volume has not been demonstrated. We examined the relationship between an FH of heavy drinking and both brain shrinkage as measured by the ratio of brain volumes to intracranial volume (ICV) as well as maximal brain growth as measured by ICV in early-onset and late-onset alcoholics. METHODS: With T1-weighted resonance imaging, we measured ICV, brain volume, and white and gray matter volume in adult treatment-seeking late-onset and early-onset alcoholics with either a positive or a negative FH of heavy alcohol use, and in healthy control subjects. We also calculated brain shrinkage using a ratio of soft tissue volumes to ICV. RESULTS: The FH positive alcoholic patients had significantly smaller ICVs than FH negative patients, suggesting smaller premorbid brain growth. Brain shrinkage did not correlate with FH. Late-onset alcoholics showed a greater difference in ICV between FH positive and FH negative patients than early-onset alcoholics. Late-onset FH positive patients also had significantly lower IQ scores than late-onset FH negative patients, and IQ scores were correlated with ICV. CONCLUSIONS: These data provide evidence that parental alcohol use might increase risk for alcoholism in offspring in part by a genetic and/or environmental effect that might be related to reduced brain growth. 相似文献
103.
血管内皮生长因子在高原脑水肿形成中作用的实验研究 总被引:4,自引:0,他引:4
目的:探讨血管内皮生长因子(VEGF)在高原脑水肿形成中的作用。方法:建立大鼠模拟高原模型,应用脑干湿重比率法定量脑水肿情况、应用荧光素钠透过率测定BBB通透性、应用实时荧光定量RT-PCR法检测脑组织VEGF mRNA含量以及应用蛋白印迹法半定量脑组织VEGF含量。结果:大鼠在高原24 h后脑组织含水率明显增高(P<0.05),荧光素钠透过率显著增加(P<0.01);VEGF mRNA转录及其表达显著增高(P<0.001)。结论:VEGF表达在高原脑水肿形成中起重要作用。 相似文献
104.
105.
Intractable tinnitus can lead to serious consequences. Study evidence indicates that the central nervous system is involved in generation and maintenance of chronic tinnitus and that tinnitus and other neurologic symptoms such as chronic pain may share similar mechanisms. Brain ablation and stimulation are used to treat chronic pain with success. Recent studies showed that ablation and stimulation in non-auditory areas resulted in tinnitus improvement. Deep brain stimulation (DBS) may be an alternative treatment for intractable tinnitus and deserves further study. 相似文献
106.
早期脑室置管行颅内压监护对中型颅脑损伤患者的预后影响 总被引:1,自引:0,他引:1
目的 探讨早期脑室置管行颅内压 (ICP)和脑灌注压 (CPP)监护在中型颅脑损伤中的临床应用价值。方法 将 12 5例伤后 2 4h入院无手术指征的中型颅脑损伤 (GCS 9~ 12分 )患者 ,随机分为ICP监护组 :入院后即经恻脑室内穿刺置管行ICP与CPP连续监测 ,根据颅内压变化调整治疗方案 ;对照组 :入院后不做ICP监测 ,依据临床观察的意识及生命体征变化 ,进行治疗。结果 颅内压监护组脱水剂剂量、应用时间均低于对照组 ,疗效优于对照组 ,两组差异有显著意义 (P <0 0 5 )。结论 中型颅脑损伤病情极不稳定 ,早期行ICP监护能及早发现病情变化 ,对及时采取有效治疗措施 ,降低死残率 ,改善预后有重要意义。 相似文献
107.
108.
将“医学微生物学”和“人体寄生虫学”整合为“病原生物学”符合现代医学教育的取向。中国医科大学是将两个教研室从形式到实质性合并为“病原生物学”教研室,并且将两门课完全融合成一门课程和一套教师队伍进行教学的少数院校之一。本文总结了在这一新学科教学和促进学科发展中的经验和体会。 相似文献
109.
Histopathological characterisation of effects of the mouse Pax6 missense mutation on eye development
Thaya Ramaesh Steven E. Williams Catriona Paul Kanna Ramaesh John D. West 《Experimental eye research》2009,89(2):263-273
Mutations in PAX6/Pax6 lead to a variety of ocular anomalies in humans and mice. The aim of the study was to characterise the ocular abnormalities caused by the missense Pax6Leca4 mutation and compare them to published observations on Pax6 alleles that are functionally equivalent to Pax6− null alleles (such as Pax6Sey and Pax6Sey-Neu) and human inherited eye diseases. Ocular features of homozygous Pax6Leca4/Leca4 and heterozygous Pax6Leca4/+ embryos at E12.5-E18.5, heterozygous Pax6Leca4/+ young mice at P18 and heterozygous Pax6Leca4/+ adults at 12 weeks were analysed histologically with their wild-type Pax6+/+ littermates. Homozygous Pax6Leca4/Leca4 fetuses died perinatally with no eyes although an optic cup rudiment with pigmented cells developed. Pax6Leca4/+ mice were microphthalmic and a range of other severe ocular phenotypes affected both the anterior and the posterior segments. In contrast to Pax6+/−, the Pax6Leca4/+ eyes had no goblet cells in the corneal epithelium, the iris was not hypoplastic and there was no lens-corneal epithelial plug. However, microphthalmia was more severe, corneal vascularisation occurred earlier (during fetal stages), pigmented cells were present in the vitreous and corneal stroma and the ciliary body was malformed or abnormal. These results show that, although Pax6Leca4/+ lacked some eye abnormalities commonly seen in Pax6Sey/+ and Pax6Sey-Neu/+ eyes, in most respects their eyes were more severely affected. These differences probably reflect both differences between the Pax6Leca4 and the Pax6Sey-Neu mutations and differences in modifier gene expression in different genetic backgrounds. The presence of pigmented cells in the cornea is a novel observation. Some Pax6Leca4/+ ocular abnormalities were similar to those present in human Peters' anomaly and persistent hyperplastic primary vitreous (PHPV) so Pax6Leca4/+ mice provide a useful model for some inherited eye diseases. 相似文献
110.