全文获取类型
收费全文 | 101592篇 |
免费 | 9953篇 |
国内免费 | 6597篇 |
专业分类
耳鼻咽喉 | 923篇 |
儿科学 | 1857篇 |
妇产科学 | 865篇 |
基础医学 | 7940篇 |
口腔科学 | 1697篇 |
临床医学 | 13572篇 |
内科学 | 10842篇 |
皮肤病学 | 1012篇 |
神经病学 | 3141篇 |
特种医学 | 3367篇 |
外国民族医学 | 26篇 |
外科学 | 8063篇 |
综合类 | 24650篇 |
现状与发展 | 14篇 |
一般理论 | 7篇 |
预防医学 | 10154篇 |
眼科学 | 1754篇 |
药学 | 13126篇 |
136篇 | |
中国医学 | 9372篇 |
肿瘤学 | 5624篇 |
出版年
2024年 | 458篇 |
2023年 | 1372篇 |
2022年 | 3744篇 |
2021年 | 4488篇 |
2020年 | 3883篇 |
2019年 | 2552篇 |
2018年 | 2698篇 |
2017年 | 3153篇 |
2016年 | 2661篇 |
2015年 | 4490篇 |
2014年 | 5647篇 |
2013年 | 6225篇 |
2012年 | 9234篇 |
2011年 | 9724篇 |
2010年 | 7940篇 |
2009年 | 6865篇 |
2008年 | 7220篇 |
2007年 | 6817篇 |
2006年 | 6119篇 |
2005年 | 5259篇 |
2004年 | 3597篇 |
2003年 | 2926篇 |
2002年 | 2331篇 |
2001年 | 1933篇 |
2000年 | 1667篇 |
1999年 | 1155篇 |
1998年 | 574篇 |
1997年 | 588篇 |
1996年 | 423篇 |
1995年 | 363篇 |
1994年 | 297篇 |
1993年 | 210篇 |
1992年 | 246篇 |
1991年 | 197篇 |
1990年 | 160篇 |
1989年 | 158篇 |
1988年 | 116篇 |
1987年 | 156篇 |
1986年 | 100篇 |
1985年 | 82篇 |
1984年 | 66篇 |
1983年 | 35篇 |
1982年 | 32篇 |
1981年 | 32篇 |
1980年 | 23篇 |
1979年 | 19篇 |
1978年 | 25篇 |
1977年 | 16篇 |
1976年 | 12篇 |
1974年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
FcγR在口腔疾病中的临床意义 总被引:1,自引:0,他引:1
IgG Fc功能区的受体(FcγR)在联系细胞免疫和体液免疫方面有其重要作用。体内多种细胞表面可表达IgG Fc受体,并通过与免疫复合物的结合参与IgG介导的生理或病理过程,调节免疫反应。本文就近年来FcγR的生化特征和在口腔疾病中临床意义的研究进展作一综述。 相似文献
42.
穹窿体是真核细胞中的核糖核蛋白颗粒,由肺耐药蛋白、穹窿体多聚腺苷二磷酸聚合酶、端粒酶相关蛋白和穹窿体RNA构成,其主要成分为肺耐药蛋白。肺耐药蛋白是介导肿瘤多药耐药的蛋白之一,可能与肿瘤的治疗效果和临床预后相关。穹窿体可能通过介导药物转运或者信号转导引起肿瘤的多药耐药。文章介绍了穹窿体的结构、成分及其介导多药耐药机制研究的新进展。 相似文献
43.
44.
Weijiang Zhao Fang Yuan Guilin Li Zhongfang Shi Yun Cui Yazhuo Zhang Zhongcheng Wang 《中国神经再生研究》2007,2(5):276-280
BACKGROUND: During formation of prolactin neoplasia, how cells and its structure in adenohypophysis affect prolactin cells should be further studied. Intermediate lobe can be regarded as a driving region to release prolactin (PRL) and may promote formation of prolactin neoplasia in pituitary anterior lobe.
OBJECTIVE: To observe the effect of diethylstilbestrol (DES) on the expressions of μ and m-calpains in pituitary intermediate lobe of female Wistar rats.
DESIGN: Observational contrast animal study.
SETTING: Beijing Neurosurgical Institute.
MATERIALS: A total of 21 female Wistar rats, 3 weeks old weighing 70–80 g were housed with free access to tap water and standard pellet food. They were kept in a CL-grade condition, at (24±1)℃ and a humidity of (55±5)%, and with a 12 hours day-night cycle. Caprine anti-μ- and m-calpains antibodies were provided by Santa Cruz Biotechnology, CA, USA; rabbit-anti-PRL antibodies by Dako, Denmark; rabbit-anti-ACTH antibody by Boster Company, Wuhan.
METHODS: The experiment was carried out in Pathophysiological Department and Animal Laboratory, Beijing Neurosurgical Institute from August 2006 to January 2007. ① Rats were randomly divided into groups with 7 in each group, including vehicle control group, in which rats were injected intraperitoneally with sun-flower seed oil (1 mL/kg, twice a week) for 16 weeks; DES group, where animals were administered with DES (5 mg/kg, twice a week) for 16 weeks; DES + vehicle control group, in which DES was administered for 12 weeks at the same dose with those in DES group, and then was discontinued and replaced by sun-flower seed oil (1 mL/kg, twice a week) for the following 4 weeks. ② At 16 weeks later, pituitary tissue was dealt with HE staining and PRL immunohistochemical examination to observe evoke of tumor; meanwhile, immunohistochemical examination was used to observe expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin.
MAIN OUTCOME MEASURES: ① Expression of PRL of pituitary anterior lobe, expressions of μ- and m-calpains of pituitary intermediate lobe and distribution of adrenocorticotropin. ② Morphological observation of pituitary tissue.
RESULTS: All 21 rats were involved in the final analysis. ① Results of immunohistochemical examination: Morphological changes of neoplasia in DES group were strongly positive to PRL, and this suggested that formation of prolactin adenoma was observed in pituitary tissue. As compared with vehicle control group, expression of adrenoeorticotropic hormone (ACTH) was increased in both DES group and DES + vehicle control group. In addition, expressions of μ- and m-calpains in pituitary intermediate lobe were higher in DES group than that in vehicle control group. Otherwise, expressions of m-calpains in pituitary intermediate lobe was decreased in DES + vehicle control group, but expression of μ-calpains was still increased. ② Morphological observation of pituitary tissue: Gland tubes were orderly arranged in rats in vehicle control group. Anterior pituitary gland in rats of DES group demonstrated an apparent disappearance of gland tubes and a relatively large-scaled vasculature formation, namely the vascular lake lined by tightly arranged endothelial cells. Local integrated tumor cell arrangements were also detected. In addition, the border between the IL and the anterior lobe was locally blurred. The definite tumor-like changes in pituitary tissues were confirmed in 6 of 7 female Wistar rats in DES group, and one spontaneous occurrence of tumor formation was found in vehicle control group. In DES + vehicle control group, DES withdrawal led to the subtile emergence of gland tube cavity, although tumor-like cells still existed in 4 of 7 rats, suggesting occurrence of the tumor regression due to the withdrawal of DES.
CONCLUSION: A long-term application of DES can enhance the expressions of ubiquitours neutral cysteine protease in pituitary intermediate lobe and this suggests that both of them play a key role in release of hormone and formation of prolactin neoplasia through directly promoting PRL expression and release of neighboring pituitary intermediate lobe. 相似文献
45.
46.
Summary Based on the gate-related receptor hypothesis, an analysis of kinetics of AN-132, a new antiarrhythmic agent, blockade of
cardiac sodium channels and the gate-related receptor which is bound by the drug was performed by computer simulation. Model-predicted
apparent rates of onset of AN-132 (30 μmol/L) blocking were 0.051, 0.038, and 0.034 AF−1 at stimulation frequencies of 1.0, 2.0 and 3.0 Hz, respectively. The time constant of recovery from block by AN-132 at resting
potential -90 mV was 39.5 s. These findings are in agreement with those experimental data documented. The analysis of gate-related
receptor shows that AN-132 binds the inactivation gate-related receptor, and the binding and unbinding are modulated by the
inactivation process. 相似文献
47.
The antinociceptive effects of morphine (5 μg) microinjected into the ventrolateral periaqueductal gray were determined using both the tail flick and the foot withdrawal responses to noxious radiant heating in lightly anesthetized rats. Intrathecal injection of appropriate antagonists was used to determine whether the antinociceptive effects of morphine were mediated byα2-noradrenergic, serotonergic, opioid, or cholinergic muscarinic receptors. The increase in the foot withdrawal response latency produced by microinjection of morphine in the ventrolateral periaqueductal gray was reversed by intrathecal injection of the cholinergic muscarinic receptor antagonist atropine, but was not affected by the a2-adrenoceptor antagonist yohimbine, the serotonergic receptor antagonist methysergide, or the opioid receptor antagonist naloxone. In contrast, the increase in the tail flick response latency produced by morphine was reduced by either yohimbine, methysergide or atropine. These results indicate that microinjection of morphine in the ventrolateral periaqueductal gray inhibits nociceptive responses to noxious heating of the tail by activating descending neuronal systems that are different from those that inhibit the nociceptive responses to noxious heating of the feet. More specifically, serotonergic, muscarinic cholinergic andα2-noradrenergic receptors appear to mediate the antinociception produced by morphine using the tail flick test. In contrast, muscarinic cholinergic, but not monoamine receptors appear to mediate the antinociceptive effects of morphine using the foot withdrawal response. 相似文献
48.
To compare the characteristics of carboxyfluorescein (CF) and calcein (Calc) with those of sodium fluorescein (Naf), the only fluorescent dye currently in clinical use, we performed angiography in rabbits and primates using these three dyes. The circulation decay time of all dyes was longer in primates than in rabbits. In primates, CF and Calc had longer decay times than Naf. Calc produced the greatest contrast between the choroidal and retinal vasculature. Tissue staining and dye leakage into the vitreous immediately after retinal photocoagulation were minimal with Calc, moderate with CF, and marked with Naf. The limited leakage and longer circulation time of Calc may permit simultaneous angiography and photocoagulation therapy without obscuring the fundus view with leaking dye from the photocoagulated structure. 相似文献
49.
目的 :探讨胫腓骨远端骨折治疗术式的选择、术中术后应注意的问题及其疗效。方法 :对不同类型的胫腓骨远端骨折 36例进行 8~ 18个月的随访 ,并结合临床及影像学资料 ,对其诊断、手术方法及治疗效果进行分析总结。结果 :本组术后 2 5~ 3 5个月骨折均愈合。踝关节功能优良率 77 7%。结论 :熟悉骨折的分型及相应内固定术式的选择 ;注重踝穴骨折的解剖复位及固定和踝关节的功能位固定及早期功能锻炼。 相似文献
50.
目的 对基层医院夜间急诊病人的需求进行调查分析,提出相应的措施。方法 对2 0 0 4年1月~8月夜间急诊病人12 0例进行无记名的问卷调查。结果 病人对医院的配备设施已有较高的要求;对护理服务态度最为满意,最满意率为95 % ,较满意率为5 % ,无1例不满意,其次是护理技术操作,满意率为90 % ,最不满意的是给病人治疗时让病人等候时间过长,不满意率达10 %。结论 通过调查做出了服从病人的需求,创立急诊绿色通道的对策 相似文献