全文获取类型
收费全文 | 84233篇 |
免费 | 7982篇 |
国内免费 | 4991篇 |
专业分类
耳鼻咽喉 | 916篇 |
儿科学 | 1575篇 |
妇产科学 | 823篇 |
基础医学 | 7979篇 |
口腔科学 | 1595篇 |
临床医学 | 10713篇 |
内科学 | 10769篇 |
皮肤病学 | 1534篇 |
神经病学 | 3103篇 |
特种医学 | 3444篇 |
外国民族医学 | 22篇 |
外科学 | 7455篇 |
综合类 | 16907篇 |
现状与发展 | 17篇 |
一般理论 | 4篇 |
预防医学 | 7919篇 |
眼科学 | 1655篇 |
药学 | 9641篇 |
93篇 | |
中国医学 | 5957篇 |
肿瘤学 | 5085篇 |
出版年
2024年 | 304篇 |
2023年 | 1116篇 |
2022年 | 2858篇 |
2021年 | 3844篇 |
2020年 | 3007篇 |
2019年 | 2369篇 |
2018年 | 2389篇 |
2017年 | 2651篇 |
2016年 | 2436篇 |
2015年 | 3947篇 |
2014年 | 5003篇 |
2013年 | 5530篇 |
2012年 | 7824篇 |
2011年 | 8066篇 |
2010年 | 6165篇 |
2009年 | 5235篇 |
2008年 | 5822篇 |
2007年 | 5373篇 |
2006年 | 5215篇 |
2005年 | 4324篇 |
2004年 | 3072篇 |
2003年 | 2597篇 |
2002年 | 2184篇 |
2001年 | 1446篇 |
2000年 | 1148篇 |
1999年 | 776篇 |
1998年 | 391篇 |
1997年 | 419篇 |
1996年 | 281篇 |
1995年 | 258篇 |
1994年 | 242篇 |
1993年 | 137篇 |
1992年 | 155篇 |
1991年 | 140篇 |
1990年 | 101篇 |
1989年 | 67篇 |
1988年 | 58篇 |
1987年 | 45篇 |
1986年 | 36篇 |
1985年 | 22篇 |
1984年 | 24篇 |
1983年 | 14篇 |
1982年 | 11篇 |
1981年 | 10篇 |
1980年 | 8篇 |
1979年 | 10篇 |
1974年 | 7篇 |
1972年 | 8篇 |
1939年 | 6篇 |
1937年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Yasuyuki Sumikawa Yuriko Ueki Akira Miyoshi Lei Cheng Min Yin Hai-Bo Shi Masuko Daitoku Sumikawa Takeshi Kono Toshiyuki Aoki Ichiro Katayama 《Arerugī》2007,56(10):1270-1275
BACKGROUND: The comparative studies of the prevalence of atopic dermatitis and skin barrier functions in Japanese and Chinese were performed. METHODS: Clinical investigations were performed in 68 elementary school students in Lhasa, Tibet Autonomous Region and 67 students in Yixing, Jiangsu Province in China, and 99 students in Nishinomiya, Hyogo in Japan. Transepidermal water loss (TEWL) and capacitance were measured. Questionary survey about bathing frequency was also performed for students in Lhasa, Yixing and Osaka. RESULT: The prevalence rate of atopic dermatitis was 0% in Lhasa, 2.63% in Yixing, 4.26% in Nishinomiya. TEWL of students in Nishinomiya was higher than that in Yixing and Lhasa. Capacitance of students in Lhasa was lower than that in Nishinomiya and Yixing. The frequency of taking a bath in Lhasa was about 2.2 times per month and fewer than that in Nishinomiya and Yixing. CONCLUSION: There was tendency that the prevalence of atopic dermatitis increased according to increase of TEWL. It was thought that more investigations are necessary whether the development of habitat and environment influence the prevalence of atopic dermatitis and skin barrier function. 相似文献
62.
三氧化二锑诱导急性早幼粒细胞白血病细胞凋亡的研究 总被引:2,自引:0,他引:2
目的 研究锑剂三氧化二锑(Sb2O3)对早幼粒细胞白血病细胞株NB4凋亡的诱导作用,以寻求早幼粒细胞白血病治疗的新方法。方法 采用细胞生长曲线,形态学及硝基四氮唑蓝(NBT)还原试验,判定NB4细胞的生长,分化及功能。采用细胞周期分析和DNA电泳研究细胞凋亡。结果 Sb2O3能诱导早幼粒白血病细胞凋亡,且具有时间,剂量依赖性。结论 Sb2O3能有效地诱导早幼粒白血病细胞凋亡,提示锑剂诱导细胞半亡的疗法,有望成为临床治疗早幼粒细胞白血病的新方法。 相似文献
63.
64.
65.
In this study, a human adult testis cDNA microarray was constructed and hybridized with (33)P-labeled human adult testis, embryo testis and sperm cDNA probes, respectively. A novel alternative splice variant of BRDT gene, named BRDT-NY, presumably involved in testicular function was cloned. It was expressed 3.96-fold more in human adult than embryo testis and also expressed in human spermatozoa. Similarly, RT-PCR revealed a differential expression pattern of this gene in human adult testes and fetal testes. The full length of BRDT-NY was 3438 bp and contained a 2883 bp open reading frame, encoding a 960-amino-acid protein. Sequence analysis showed that it has two bromodomains in N-terminal of the protein. Multiple tissue RT-PCR results showed that BRDT-NY was exclusively expressed in testis. mRNA expression of BRDT-NY gene was deleted in some azoospermic patients' testes. These experiments suggested that BRDT-NY gene may have an important role in the process of spermatogenesis and may be correlated with male infertility. 相似文献
66.
Nonvascular intervention of the urinary tract is a well-established uroradiologic subspecialty, which is more important for avoiding invasive open surgery in the age of rising demand about the value of less invasive treatment. Various kinds of nonvascular intervention are recently performed under image-guidance and are as follows: percutaneous nephrostomy, percutaneous nephrostolithotomy, percutaneous dilatation of the urinary tract, sclerotherapy for renal cysts, percutaneous catheter drainage, percutaneous foreign body retrieval and biopsy. Percutaneous nephrostomy is a basic technique to provide a direct access to urinary tract, which makes it possible to perform other interventional procedures. Although nonvascular intervention may produce some complications, it is generally considered to be less invasive than open surgery and has advantages such as short hospital stay, early return to normal life and therefore economic savings. This review is described to help clinicians easily understand the procedures, indications, techniques, and complications with figures of cases the authors experienced. 相似文献
67.
Hosoi K Min KY Shiima C Hanafusa T Mori H Nakahari T 《The Japanese journal of physiology》2002,52(6):561-572
Changes in the volume of rat alveolar type II cells (AT-II cells) induced by terbutaline, a beta(2)-agonist, were measured using video-enhanced contrast microscopy. The changes consisted of three phases: initial cell shrinkage, cell swelling, and gradual cell shrinkage. The initial cell shrinkage was Ca(2+)-dependent and was inhibited by quinine (a K+ channel blocker). The subsequent cell swelling was cAMP-dependent and was inhibited by amiloride (a Na+ channel blocker). The final cell shrinkage was cAMP-dependent and was inhibited by 5-nitro-2-(3-phenylpropylamino)-benzoate (NPPB, a Cl- channel blocker). Thus, terbutaline-induced cell volume changes were regulated by both Ca2+ and cAMP. Accumulation of cAMP alone, however, induced the Ca2+ -dependent cell shrinkage of AT-II cells and H-89 (a PKA inhibitor) inhibited terbutaline-induced cell volume changes. This suggests that cAMP accumulation stimulates the Ca2+ signal during terbutaline stimulation. In conclusion, terbutaline stimulates not only Na+ influx, but also K+ and Cl- release mediated via cAMP accumulation in rat AT-II cells, which induces the triphasic cell volume changes. 相似文献
68.
We report a case of papillary carcinoma arising in a thyroglossal duct cyst, presenting with an anterior neck mass of a 31-year-old woman. The tumor was judged to be a primary lesion on the basis of intraoperative examination of the thyroid and pathologic findings of the mass. One year later, a small nodular mass in the left thyroid gland and lymph node enlargement of the right cervical lymph node were noted by follow-up imaging studies. Total thyroidectomy, right modified radical neck dissection and central neck dissection were performed. The thyroid gland revealed nodular hyperplasia without evidence of malignancy. On the other hand, the dissected neck lymph nodes revealed metastatic papillary carcinoma. Taken together, these findings suggested the tumor was a primary papillary carcinoma arising in the thyroglossal duct cyst. 相似文献
69.
TRIO amplification and abundant mRNA expression is associated with invasive tumor growth and rapid tumor cell proliferation in urinary bladder cancer 下载免费PDF全文
Zheng M Simon R Mirlacher M Maurer R Gasser T Forster T Diener PA Mihatsch MJ Sauter G Schraml P 《The American journal of pathology》2004,165(1):63-69
Studies by comparative genome hybridization have suggested that 5p amplification is related to tumor progression in urinary bladder cancer. In this study seven genes (TAS2R, ADCY2, DNAH5, CTNND2, TRIO, ANKH, and MYO10) located to 5p15.31-5p15.1 were analyzed by fluorescence in situ hybridization using a tissue microarray containing samples from tumors and cell lines with known 5p amplification by comparative genome hybridization. Amplification frequency was highest for TRIO, which maps to 5p15.2 and encodes a protein with a putative role in cell-cycle regulation. To further investigate the role of TRIO amplification in bladder cancer, a tissue microarray containing samples from 2317 bladder tumors was used for fluorescence in situ hybridization analysis. TRIO amplification was strongly associated with invasive tumor phenotype, high tumor grade, and rapid tumor cell proliferation (Ki67 LI) (P < 0.0001 each). Only 7 of 456 pTaG1/G2 tumors (1.5%) but 62 of 485 pT1-4 carcinomas (12.8%) had TRIO amplification. TRIO amplification was not associated with poor prognosis. Using a frozen bladder tumor tissue microarray RNA in situ hybridization confirmed that TRIO is up-regulated in amplified tumors. It is concluded that TRIO up-regulation through amplification has a potential role in bladder cancer progression. 相似文献
70.
Nam KW Chung J Choi SW Kim WE Sun K Min BG 《The International journal of artificial organs》2004,27(10):882-890
A pulsatile left ventricular assist device (LVAD) was used to support the aortic blood pumping function of an injured left ventricle, and as a result helped its recovery. It is important to observe a left ventricle's pumping status and to adjust the operating status of a LVAD to reduce the left ventricle's pumping load and thus to enhance its recovery. To observe the left ventricle's pumping status, an electrocardiogram (ECG) signal is generally used because it is a result of the natural heart's blood pumping function. In this paper, we describe the development of an ECG based counterpulsation control algorithm that prevents simultaneous aortic blood co-pumping by a left ventricle and a moving-actuator type pulsatile LVAD and as a result, reduces the natural heart's pumping load. In addition, to verify the algorithm's applicability for LVAD control we designed three ECG based automatic pump control algorithms that use a developed counterpulsation control algorithm. These algorithms control the operating status of a LVAD automatically and, at the same time, maintain a counterpulsing status. The results of in vitro experiments show that the counterpulsing effect between a left ventricle and a LVAD was successfully produced and that the newly designed automatic pump control algorithms met their own control purposes with a counterpulsing effect. 相似文献