全文获取类型
收费全文 | 305篇 |
免费 | 19篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 5篇 |
妇产科学 | 3篇 |
基础医学 | 62篇 |
口腔科学 | 4篇 |
临床医学 | 7篇 |
内科学 | 33篇 |
皮肤病学 | 1篇 |
神经病学 | 3篇 |
特种医学 | 3篇 |
外科学 | 6篇 |
综合类 | 53篇 |
预防医学 | 15篇 |
眼科学 | 1篇 |
药学 | 24篇 |
中国医学 | 93篇 |
肿瘤学 | 11篇 |
出版年
2024年 | 4篇 |
2023年 | 2篇 |
2022年 | 8篇 |
2021年 | 9篇 |
2020年 | 9篇 |
2019年 | 8篇 |
2018年 | 9篇 |
2017年 | 15篇 |
2016年 | 11篇 |
2015年 | 10篇 |
2014年 | 26篇 |
2013年 | 18篇 |
2012年 | 15篇 |
2011年 | 27篇 |
2010年 | 11篇 |
2009年 | 27篇 |
2008年 | 9篇 |
2007年 | 12篇 |
2006年 | 14篇 |
2005年 | 7篇 |
2004年 | 7篇 |
2003年 | 8篇 |
2002年 | 6篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 4篇 |
1996年 | 1篇 |
1995年 | 4篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1991年 | 1篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1986年 | 3篇 |
1985年 | 2篇 |
1984年 | 4篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1978年 | 4篇 |
1974年 | 1篇 |
1972年 | 1篇 |
1969年 | 1篇 |
排序方式: 共有326条查询结果,搜索用时 15 毫秒
1.
膝关节动脉血液供应的初步观察 总被引:2,自引:0,他引:2
本文选择固定和新鲜尸体下肢标本57侧,采用局部解剖、动脉铸型、动脉造影和标本透明等方法,对膝关节动脉血液供应作了初步观察。动脉关节支起点变异和共干形式,以右侧居多。膝区各动脉均有特殊的形态和一定的分布区域,在每一局部几个血液供应来源中,总有一个主次关系和层次关系。膝区动脉按口径大小,可以分成3组。口径的变化除了可以评价局部血液供应丰富的程度外,也是衡量相邻动脉大小的指征。整个膝区动脉血液供应配布比较均匀对称。供应膝关节的各动脉起点的高度是恒定的,相互间保持一定关系。本文还就纯关节支和肌关节支的概念、动脉吻合、局部“乏血管区”、髌前动脉网与髌骨血液供应的关系等进行了简单讨论。 相似文献
2.
H1N2新亚型流感病毒神经氨酸酶基因来源的进一步研究 总被引:1,自引:0,他引:1
对流感病毒H1N2亚型重组株A/哈防/1/88、A/哈防/12/92以及H3N2亚型病毒株A/雅防/2/87、A/京防/57/898和A/粤防/1/92神经氨酸酶(NA)基因核苷酸全序列的测定,进一步弄清了A/哈防/1/88病毒株的NA基因确来自当时人群中流行的H3N2亚型病毒株,很可能是来自A/雅防/2/87类病毒株;而A/哈防/12/92病毒株的NA基因可能是与A/哈防/1/88病毒株的NA基 相似文献
3.
Origin of impulse initiation in the slowly adapting stretch receptor of the crayfish 总被引:1,自引:0,他引:1
Summary Characteristic for the crayfish stretch receptor is a gradual decrease in axon diameter up to a stretch of axon about 350 m away from the soma-axon border. In response to depolarizing currents applied at different positions along the axon this stretch of axon can be localized as the most excitable membrane region. When depolarizing current steps of 10–25 nA intensity are injected into the soma the first impulse is always triggered in the soma (due to sudden rise in the membrane potential) while the second impulse originates at the axon region of highest escitability. As the intensity of the stimulus is increased the site of impulse initiation along the axon shifts nearer to the receptor soma. At a stimulus intensity of 50 nA the second impulse is suppressed and only the membrane potential at the axon hillock increases slightly. An analysis of the conductances for sodium and potassium ions as well as of the leakage current suggests that the molecular basis for the observed variations in excitability resides in a gradual decrease of the sodium conductance between the cell soma and the small-diameter region of the axon. However, the resting potential in this most excitable axon region is only some 3 mV more positive as compared to the receptor soma. A mathematical formulation is presented for the encoder mechanism in a soma-axon region with varying diameter. Using a slightly modified form of the Hodgkin-Huxley equations the experimentally observed changes in membrane potential and in the time course of the ionic currents can be adequately described by applying a nonlinear cable equation to the inhomogeneous axon. 相似文献
4.
肇自晋唐、盛于明清的“新安医学”在中医学发展史中具有重要地位。作者对新安临床医家中具有代表性的医学家族 :徽州歙县定潭“张一帖”的源流进行了详细考证。认为“张一帖”之名起于明嘉靖年间 ,传承至今 ,计 45 0余年、15代的历史。张氏历代以急性热病、内科疑难杂病为其精擅 ,传有“末药”等名方 ,并对张氏各代的临床特色予以简要考辨、探讨。认为区域性医学流派、代表性医学家族链曾是中医学发展过程中的重要建构形式之一。 相似文献
5.
We describe a rare case of medulloblastoma in an adult woman with histological findings suggesting an origin for this neoplasm
in the external granular layer or its remnants. The patient presented with cerebellar dysfunction, and neuroimaging revealed
a right cerebellar mass lesion. Pathological examination of the operative specimen revealed a medulloblastoma with occasional
areas of neuronal or glial differentiation. Zic protein was also detected immunohistochemically in the tumor cells. The tumor
cells were mainly distributed in the subarachnoid space and extended to the cerebellar parenchyma through the perivascular
space to form tumor nodules. A suggestive finding, as concerns the origin of this neoplasm, was that the tumor cells were
also spread evenly along the subpial zone of the molecular layer, reminiscent of the cellular architecture of the fetal external
granular layer. 相似文献
6.
Jo?o Dinis de Sousa Carolina Alvarez Anne-Mieke Vandamme Viktor Müller 《Viruses》2012,4(10):1950-1983
HIV-1 M originated from SIVcpz endemic in chimpanzees from southeast Cameroon or neighboring areas, and it started to spread in the early 20th century. Here we examine the factors that may have contributed to simian-to-human transmission, local transmission between humans, and export to a city. The region had intense ape hunting, social disruption, commercial sex work, STDs, and traffic to/from Kinshasa in the period 1899–1923. Injection treatments increased sharply around 1930; however, their frequency among local patients was far lower than among modern groups experiencing parenteral HIV-1 outbreaks. Recent molecular datings of HIV-1 M fit better the period of maximal resource exploitation and trade links than the period of high injection intensity. We conclude that although local parenteral outbreaks might have occurred, these are unlikely to have caused massive transmission. World War I led to additional, and hitherto unrecognized, risks of HIV-1 emergence. We propose an Enhanced Heterosexual Transmission Hypothesis for the origin of HIV-1 M, featuring at the time and place of its origin a coincidence of favorable co-factors (ape hunting, social disruption, STDs, and mobility) for both cross-species transmission and heterosexual spread. Our hypothesis does not exclude a role for parenteral transmission in the initial viral adaptation. 相似文献
7.
目的采用Origin软件拟合DXI 800发光仪的四参数logistic定标数据,比较其与DXI 800计算的数据差异,探讨采用Origin软件计算DXI 800未知数据的可能性。方法选择睾酮、总甲状腺素、雌二醇、肌钙蛋白I、促甲状腺激素、癌胚抗原和孕酮的定标数据,采用Origin软件拟合四参数logistic计算结果,与DXI 800发光仪计算的结果比较。结果采用Origin软件计算的结果与DXI 800计算的结果基本一致,平均偏倚介于-0.85%~1.68%之间。结论可以采用Origin软件计算DXI 800发光仪的未知结果。 相似文献
8.
9.
Dong Kyu Lim Changyeun Mo Dong-Kyu Lee Nguyen Phuoc Long Jongguk Lim Sung Won Kwon 《Yao wu shi pin fen xi = Journal of food and drug analysis.》2018,26(1):260-267
The authenticity determination of white rice is crucial to prevent deceptive origin labeling and dishonest trading. However, a non-destructive and comprehensive method for rapidly discriminating the geographical origins of white rice between countries is still lacking. In the current study, we developed a volatile organic compound based geographical discrimination method using headspace solid-phase microextraction coupled to gas chromatography–mass spectrometry (HS-SPME/GC–MS) to discriminate rice samples from Korea and China. A partial least squares discriminant analysis (PLS-DA) model exhibited a good classification of white rice between Korea and China (accuracy = 0.958, goodness of fit = 0.937, goodness of prediction = 0.831, and permutation test p-value = 0.043). Combining the PLS-DA based feature selection with the differentially expressed features from the unpaired t-test and significance analysis of microarrays, 12 discriminatory biomarkers were found. Among them, hexanal and 1-hexanol have been previously known to be associated with the cultivation environment and storage conditions. Other hydrocarbon biomarkers are novel, and their impact on rice production and storage remains to be elucidated. In conclusion, our findings highlight the ability to rapidly discriminate white rice from Korea and China. The developed method maybe useful for the authenticity and quality control of white rice. 相似文献
10.
目的探讨不同产地石膏成分含量差异,为临床应用提供依据。方法选取十个产地石膏样品,采用乙二胺四乙酸二钠(EDTA-2Na)滴定法进行含水硫酸钙含量测定,分析不同产地及不同产区石膏含水硫酸钙含量。结果各产地石膏样品含水硫酸钙含量均超过95%,符合国家药典委员会制定《中华人民共和国药典》(2010年)测定要求;湖北荆门产区石膏样品含水硫酸钙含量平均值最高,以下依次为湖北应城产区、河北邢台及河南三门峡;其中湖北荆门产区又以磊鑫石膏有限公司提供样品含水硫酸钙含量最高,达到99.772%;而不同颜色石膏中白色石膏含水硫酸钙含量最高,以下依次为红色石膏、透明石膏,蜡黄色石膏含量最低。结论各产区石膏含水硫酸钙含量均达到国家标准;湖北荆门地区石膏含水硫酸钙含量高于其他地区,其中尤以磊鑫石膏有限公司含量最高。 相似文献