全文获取类型
收费全文 | 14850篇 |
免费 | 1834篇 |
国内免费 | 363篇 |
专业分类
耳鼻咽喉 | 598篇 |
儿科学 | 329篇 |
妇产科学 | 154篇 |
基础医学 | 2329篇 |
口腔科学 | 148篇 |
临床医学 | 1726篇 |
内科学 | 1389篇 |
皮肤病学 | 133篇 |
神经病学 | 482篇 |
特种医学 | 735篇 |
外国民族医学 | 16篇 |
外科学 | 2187篇 |
综合类 | 2534篇 |
预防医学 | 556篇 |
眼科学 | 304篇 |
药学 | 765篇 |
18篇 | |
中国医学 | 280篇 |
肿瘤学 | 2364篇 |
出版年
2024年 | 73篇 |
2023年 | 316篇 |
2022年 | 662篇 |
2021年 | 823篇 |
2020年 | 820篇 |
2019年 | 674篇 |
2018年 | 621篇 |
2017年 | 672篇 |
2016年 | 753篇 |
2015年 | 699篇 |
2014年 | 1081篇 |
2013年 | 968篇 |
2012年 | 788篇 |
2011年 | 883篇 |
2010年 | 643篇 |
2009年 | 571篇 |
2008年 | 608篇 |
2007年 | 589篇 |
2006年 | 543篇 |
2005年 | 457篇 |
2004年 | 403篇 |
2003年 | 357篇 |
2002年 | 296篇 |
2001年 | 276篇 |
2000年 | 257篇 |
1999年 | 208篇 |
1998年 | 202篇 |
1997年 | 172篇 |
1996年 | 165篇 |
1995年 | 158篇 |
1994年 | 133篇 |
1993年 | 136篇 |
1992年 | 111篇 |
1991年 | 98篇 |
1990年 | 84篇 |
1989年 | 74篇 |
1988年 | 65篇 |
1987年 | 62篇 |
1986年 | 78篇 |
1985年 | 76篇 |
1984年 | 57篇 |
1983年 | 30篇 |
1982年 | 50篇 |
1981年 | 52篇 |
1980年 | 45篇 |
1979年 | 26篇 |
1978年 | 29篇 |
1977年 | 35篇 |
1975年 | 20篇 |
1974年 | 14篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
补益中药对老龄雄性大鼠下丘脑神经递质——甲状腺轴机能作用的研究 总被引:3,自引:0,他引:3
本文通过对3月龄、18月龄、24月龄雄性大鼠下丘脑去甲肾上腺素(NE)、多巴胺(DA)、5-羟色胺(5-HT)、5-羟吲哚乙酸(5-HIAA),和下丘脑垂体促甲状腺释放激素(TRH)、垂体、血甲状腺释放激素(TSH)、血甲状腺激素(T_3、T_4)的测定,研究了大鼠下丘脑神经递质与甲状腺轴机能的增龄性变化,并在此基础上探讨了补益中药对老龄大鼠下丘脑—垂体—甲状腺机能的作用。结果提示:老龄大鼠下丘脑机能的减退是甲状腺轴机能减退的重要原因;补益中药可能改善了老龄大鼠下丘脑的调控机能,进而延缓了甲状腺轴机能的老年性变化。 相似文献
62.
Yoshio Kasuga MD Akira Sugenoya Shinya Kobayashi Gengo Kaneko Hiroyuki Masuda Minoru Fujimori Shozo Takahashi Futoshi Iida 《Surgery today》1990,20(3):283-289
The purpose of this study was to evaluate the acute effects of corticosteroid and iodide preoperative therapy in patients
with Graves' disease in terms of thyroid function and immunological parameters. The above combination was prescribed for 4
patients who had experienced severe side effects from antithyroid drugs (ATD) in order to reduce the possibility of post-thyroidectomy
thyroid storm. Corticosteroids were employed daily for four days, and iodides were given daily for two weeks prior to thyroidectomy.
The free T3 values decreased rapidly to euthyroid levels following the administration of both drugs, although the free T4 values were still much higher than normal in 3 of the 4 patients at the time of surgery. By comparison, 3 of 8 patients treated
with ATD also had thyroid hormone levels above normal. Studies of lymphocyte subsets revealed that the percentage of helper
T cells was significantly less in the corticosteroidiodide treatment group than in the control and ATD groups. It is thus
possible that postoperative thyroid storm might be prevented through corticosteroid-iodide therapy by virtue of the reduction
of free T3 values to within the normal range by the time of surgery. The acute suppression of helper T cells was another result of this
form of therapy observed. 相似文献
63.
Primary leiomyosarcoma of the thyroid gland 总被引:1,自引:0,他引:1
Osamu Ozaki Kiminori Sugino Takashi Mimura Kunihiko Ito Seiichi Tamai Yasuhiro Hosoda 《Surgery today》1997,27(2):177-180
Primary leiomyosarcoma of the thyroid gland is extremely rare, and to the best of our knowledge only five well-documented
cases have been reported in the world literature. We herein report a 58-year-old female patient with primary leiomyosarcoma
of the thyroid who was successfully treated by total thyroidectomy with a modified neck dissection. Immunohistochemically,
the tumor cells showed positive reactivity to α-smooth muscle actin and vimentin. Radical surgery was thus considered to be
essential in the treatment of this rare but rather aggressive malignancy. 相似文献
64.
抗人甲状腺过氧化物酶抗体与其他自身抗体的关系 总被引:1,自引:1,他引:0
甲状腺过氧化物酶(TPO)是甲状腺微粒体的抗原成分。在纯化抗原建立测定抗TPO抗体ELISA法的基础上,并对抗TPO与其他自身抗体的伴随关系作了研究。发现除自身免疫性甲状腺病有较高阳性率外,SLE等患者抗TPO检出率也很高(10% ̄52.1%),且抗TPO阳性者,抗核抗体等其他自身抗体的阳性率也高达30.8% ̄95.2%。抗TPO抗体与其他自身抗体的相关系数r=0.7467(P〈0.01)。 相似文献
65.
将Wistar大鼠分为三组:肝硬化组,给予四氯化碳等复合因素,给药组,除给CCl4等复合因素外,用赤栀黄合剂灌胃41天;正常组给以一般饮食及饮水。结果,与正常组及给药组相比,硬化组血T3、T4测定值低,甲状腺滤泡中胶质明显减少,滤泡细胞与胶质间空泡增多,滤泡上皮细胞内PAS阳性小滴数日增多。表明在实验性肝硬化期间甲状腺参与了抗疾病的代谢活动,其机理可能是肝硬化时肝细胞合成、转运T3,T4的蛋白质减少。运输中的T3,T4减少,活性甲状腺素不足,从而导致甲状腺代偿性功能活跃。赤栀黄合剂具有保肝,恢复甲状腺素水平的作用。 相似文献
66.
Rounded atelectasis, a rare, benign mass lesion, is most often seen in association with asbestos-related pleural changes. Often a presumptive diagnosis can be made on the basis of characteristic CT and chest radiographic findings. However, not infrequently radiographic imaging fails to differentiate rounded atelectasis from primary bronchogenic carcinoma, a disease which is seen with increased frequency in patients with asbestos exposure. We describe two cases where the diagnosis of rounded atelectasis was made by fine-needle aspiration (FNA) cytology. The cytologic features included abundant pulmonary parenchymal material with thickened alveolar walls containing pulmonary macrophages and connective tissue. It is important to realize that this is a useful positive finding indicating rounded atelectasis, rather than a negative finding suggesting the absence of neoplasm. Needles with a cutting action may be necessary to obtain sufficient material to make the diagnosis of rounded atelectasis. 相似文献
67.
Francesco Franceschi Umile Giuseppe Longo Laura Ruzzini Paolo Simoni Bruno Beomonte Zobel Vincenzo Denaro 《Knee surgery, sports traumatology, arthroscopy》2007,15(3):266-268
Bilateral discoid medial menisci is an extremely rare condition of the knee and it can be associated to other pathological
findings, including anterior portion cyst formation. We report on the clinical features, radiographic findings, treatment
and results of one patient who presented a bilateral medial discoid meniscus combined with posterior portion cyst of the left
knee. To the best of the author’s knowledge, this is the first case of bilateral medial discoid meniscus associated with posterior
portion cyst formation. 相似文献
68.
高碘摄入对SD大鼠钠/碘同向转运体蛋白表达影响的免疫组化研究 总被引:2,自引:0,他引:2
目的:动态观察长期高碘摄入对SD大鼠甲状腺细胞钠/碘同向转运体(NIS)蛋白表达的影响.方法:SD大鼠分别饲以去离子水及不同碘浓度的碘化钾水,给碘后1 d及1,2,4,8周处死.测定尿碘、组织碘含量,免疫组织化学方法观察甲状腺细胞NIS蛋白表达水平.结果:高碘摄入可引起甲状腺滤泡细胞膜表面NIS蛋白表达的下降.短期较低浓度的高碘摄入对NiS蛋白的表达无明显影响,而较高浓度的碘摄入则引起NIS蛋白表达的明显减少;长期高碘摄入对NIS蛋白表达的抑制作用,可在机体自我调节机制作用下得以部分恢复,但NIS蛋白表达仍处较低水平.结论:高碘摄入可导致甲状腺细胞表面NIS蛋白表达下降,随摄碘浓度的增加抑制作用增强;不同浓度的碘摄入对NIS蛋白表达的抑制作用表达时间不同. 相似文献
69.
We report a patient with metastatic thyroid carcinoma invading the esophagus in whom barium and MR examinations revealed an expansile intraluminal mass indistinguishable from that of a primary esophageal malignancy. Metastatic thyroid carcinoma should therefore be included in the differential diagnosis of an expansile esophageal mass. As in our patient, MR imaging may be useful for showing that the mass originates in the thyroid gland. 相似文献
70.