全文获取类型
收费全文 | 32716篇 |
免费 | 3828篇 |
国内免费 | 2246篇 |
专业分类
耳鼻咽喉 | 240篇 |
儿科学 | 388篇 |
妇产科学 | 307篇 |
基础医学 | 3499篇 |
口腔科学 | 715篇 |
临床医学 | 4679篇 |
内科学 | 4098篇 |
皮肤病学 | 355篇 |
神经病学 | 1530篇 |
特种医学 | 1191篇 |
外国民族医学 | 32篇 |
外科学 | 3000篇 |
综合类 | 6147篇 |
现状与发展 | 6篇 |
一般理论 | 4篇 |
预防医学 | 2641篇 |
眼科学 | 753篇 |
药学 | 3744篇 |
74篇 | |
中国医学 | 2746篇 |
肿瘤学 | 2641篇 |
出版年
2024年 | 220篇 |
2023年 | 824篇 |
2022年 | 1967篇 |
2021年 | 2306篇 |
2020年 | 1790篇 |
2019年 | 1386篇 |
2018年 | 1350篇 |
2017年 | 1399篇 |
2016年 | 1204篇 |
2015年 | 1826篇 |
2014年 | 2093篇 |
2013年 | 1946篇 |
2012年 | 2445篇 |
2011年 | 2663篇 |
2010年 | 1715篇 |
2009年 | 1498篇 |
2008年 | 1709篇 |
2007年 | 1552篇 |
2006年 | 1462篇 |
2005年 | 1318篇 |
2004年 | 834篇 |
2003年 | 802篇 |
2002年 | 694篇 |
2001年 | 507篇 |
2000年 | 530篇 |
1999年 | 562篇 |
1998年 | 314篇 |
1997年 | 316篇 |
1996年 | 212篇 |
1995年 | 207篇 |
1994年 | 172篇 |
1993年 | 110篇 |
1992年 | 122篇 |
1991年 | 100篇 |
1990年 | 110篇 |
1989年 | 84篇 |
1988年 | 99篇 |
1987年 | 57篇 |
1986年 | 49篇 |
1985年 | 34篇 |
1984年 | 13篇 |
1983年 | 15篇 |
1981年 | 13篇 |
1979年 | 19篇 |
1977年 | 10篇 |
1975年 | 11篇 |
1974年 | 10篇 |
1973年 | 15篇 |
1969年 | 14篇 |
1966年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
991.
对175例轻型颅脑外伤病人(分为脑震荡组和不伴意识障碍的轻度闭合性头部外伤组)进行脑电图(EEG)和脑电地形图(BEAM)研究,结果表明,前组EEG(50.2%)及BEAM(57.4%)异常率明显高于后组,提示伴有意识障碍的脑外伤更易引起脑波异常。 相似文献
992.
Sun Y Shao H Li Z Liu J Gao L Peng X Meng Y Li W 《International journal of molecular medicine》2004,14(6):971-975
The advancement in gene knockout and transgenesis have brought about enormous improvement in our understanding of mouse embryogenesis in the past decade or so. On the other hand, relatively little is known about human embryogenesis due largely to the lack of easy access to human embryos and tissues for biomedical studies. We have previously isolated a novel zinc finger gene, ZNF268, from a 3-week-old human embryo cDNA library in an effort to identify genes important for human embryonic development. To investigate the potential involvement of ZNF268 in human embryogenesis, we report here the spatial and temporal regulation of its expression during development. Northern blot and Western blot analyses revealed that ZNF268 is expressed in early embryos, predominantly, if not exclusively, in fetal liver with little detectable expression in other fetal organs. Interestingly, unlike most zinc finger proteins, ZNF268 protein was found to be localized mainly in the cytoplasm of embryonic hepatocytes. This subcellular localization was substantiated by the localization of EGFP-ZNF268 fusion protein overexpressed in the transfected COS7 cells. These results suggest that ZNF268 plays a role in early human liver development most likely by functioning through a cytoplasmic mechanism. 相似文献
993.
Meng Xiangdong Anderson Allen F Wang Lu Li Zhihe Guo Wei Lee Zixuan Jin Huixin Cai Yong 《AIDS research and therapy》2010,7(1):1-8
Background
In the HAART era, the incidence of HIV-associated non-Hodgkin lymphoma (NHL) is decreasing. We describe cases of NHL among patients with multi-class antiretroviral resistance diagnosed rapidly after initiating newer-class antiretrovirals, and examine the immunologic and virologic factors associated with potential IRIS-mediated NHL.Methods
During December 2006 to January 2008, eligible HIV-infected patients from two affiliated clinics accessed Expanded Access Program antiretrovirals of raltegravir, etravirine, and/or maraviroc with optimized background. A NHL case was defined as a pathologically-confirmed tissue diagnosis in a patient without prior NHL developing symptoms after starting newer-class antiretrovirals. Mean change in CD4 and log10 VL in NHL cases compared to controls was analyzed at week 12, a time point at which values were collected among all cases.Results
Five cases occurred among 78 patients (mean incidence = 64.1/1000 patient-years). All cases received raltegravir and one received etravirine. Median symptom onset from newer-class antiretroviral initiation was 5 weeks. At baseline, the median CD4 and VL for NHL cases (n = 5) versus controls (n = 73) were 44 vs.117 cells/mm3 (p = 0.09) and 5.2 vs. 4.2 log10 (p = 0.06), respectively. The mean increase in CD4 at week 12 in NHL cases compared to controls was 13 (n = 5) vs. 74 (n = 50)(p = 0.284). Mean VL log10 reduction in NHL cases versus controls at week 12 was 2.79 (n = 5) vs. 1.94 (n = 50)(p = 0.045).Conclusions
An unexpectedly high rate of NHL was detected among treatment-experienced patients achieving a high level of virologic response with newer-class antiretrovirals. We observed trends toward lower baseline CD4 and higher baseline VL in NHL cases, with a significantly greater decline in VL among cases by 12 weeks. HIV-related NHL can occur in the setting of immune reconstitution. Potential immunologic, virologic, and newer-class antiretroviral-specific factors associated with rapid development of NHL warrants further investigation. 相似文献994.
目的探讨流式细胞术在评估男性不育中的应用。方法依照WHO诊断标准,将30例正常生育男性和45例男性不育患者的精子标记相应的荧光染料,用流式细胞仪检测精子的染色质状态,并与精液常规检测方法进行比较分析。结果男性不育患者精子DNA碎片率(15.96±8.23)%高于正常生育组(8.05±3.83)%,而且不育组精子畸形率(36.67±11.2)%也高于正常组(30.23±4.75)%,活率和密度(61.62±12.65)(43.25±16.06)%均低于正常组(70.69±4.40)(57.89±21.58)%,且DNA碎片率与精子畸形率呈正相关(r=0.371,P〈0.01),与精子活率呈负相关(r=-0.349,P〈0.01)。结论流式细胞术与常规检测方法相比,不仅具有快速、精确的优点,还可以了解精子DNA的受损程度,评价精子功能,是一种比传统精液分析更稳定更敏感的评估男性生育力的方法。 相似文献
995.
目的:调查分析听障儿童家庭运用听觉口语法实施家庭教育的现状和困境,为听障儿童家庭康复训练提供支持和帮助。方法自编调查问卷,对内蒙古地区100例听障儿童家长进行问卷调查,采用SPSS 19.0对数据进行统计分析。结果听障儿童家庭对听觉口语法的教学理念和方法掌握程度较差,对家庭教育康复训练的重视程度不够,作业反馈少且缺乏与教师的沟通。结论听障儿童家长迫切需要实施听觉口语法家庭康复训练的支持和帮助,康复机构教师应加强与家长的沟通、协调与指导,使听觉口语法在听障儿童家庭教育中发挥更大的作用。 相似文献
996.
Clinical predictors of effective continuous positive airway pressure in patients with obstructive sleep apnea/hypopnea syndrome 下载免费PDF全文
997.
目的 观察红外线照射在大鼠慢性萎缩性胃炎(chronic atrophic gastritis,CAG)中对增殖细胞核抗原(proliferating cell nuclear antigen,PCNA)和B细胞淋巴瘤/白血病-2(B-cell lymphoma-2,Bcl-2)表达的影响,探讨红外线与胃黏膜癌前病变、细胞凋亡的关系.方法 应用水杨酸钠和酒精的混合溶液灌胃,并结合劳累、饥饱失常等多因素建立大鼠CAG模型,采用红外线灯照射CAG大鼠,免疫组化法检测各组大鼠PCNA及Bcl-2的表达.结果 PCNA及Bcl-2在模型对照组胃黏膜中均呈高表达(P〈0.05),但在红外线组均无显著降低.结论 红外线照射未能降低PCNA及Bcl-2 的表达,细胞的增殖调节改善作用不明显. 相似文献
998.
目的:探讨了原发性高血压肾病患者血浆瘦素(leptin)和血清脂联素(APN)及尿微量白蛋白(mAlb)水平的变化及意义。方法:应用放射免疫分析、酶联免疫法和化学法对38例原发性高血压肾病患者血浆leptin和血清APN及尿mAlb进行检测,并与35名正常健康人作比较。结果:原发性高血压肾病患者血浆leptin和尿mAlb水平非常显著地高于正常人组(P<0.01)。而血清APN水平则显著地低于正常人组(P<0.01)。血清APN水平与leptin、尿mAlb水平呈显著的负相关(r=-0.4084、-0.5132,P<0.01)。结论:检测原发性高血压肾病患者血浆leptin和血清APN及尿mAlb水平的变化对了解病情、探讨其发病机理、预防和指导用药均有重要的临床价值。 相似文献
999.
目的了解C6细胞在体外对黏液瘤病毒的易感性,并测定黏液瘤病毒对体外C6胶质瘤细胞的杀灭作用。方法以黏液瘤病毒感染体外培养的C6胶质瘤细胞,以灭活病毒作为阴性对照,5-Fu作为阳性对照,DEMD液做空白对照,应用Western—Blot法、倒置显微镜及MTT法观察各组细胞的形态、成活率。结果病毒感染组及5-Fu组24h后细胞成活率明显低于空白对照组及阴性对照组,同时病毒感染组细胞出现明显细胞病变。结论C6胶质瘤细胞在体外对黏液瘤病毒易感,黏液瘤病毒在体外对C6胶质瘤细胞有杀灭作用。 相似文献
1000.
Jones S Li M Parsons DW Zhang X Wesseling J Kristel P Schmidt MK Markowitz S Yan H Bigner D Hruban RH Eshleman JR Iacobuzio-Donahue CA Goggins M Maitra A Malek SN Powell S Vogelstein B Kinzler KW Velculescu VE Papadopoulos N 《Human mutation》2012,33(1):100-103
Mutations in the chromatin remodeling gene ARID1A have recently been identified in the majority of ovarian clear cell carcinomas (OCCCs). To determine the prevalence of mutations in other tumor types, we evaluated 759 malignant neoplasms including those of the pancreas, breast, colon, stomach, lung, prostate, brain, and blood (leukemias). We identified truncating mutations in 6% of the neoplasms studied; nontruncating somatic mutations were identified in an additional 0.4% of neoplasms. Mutations were most commonly found in gastrointestinal samples with 12 of 119 (10%) colorectal and 10 of 100 (10%) gastric neoplasms, respectively, harboring changes. More than half of the mutated colorectal and gastric cancers displayed microsatellite instability (MSI) and the mutations in these tumors were out-of-frame insertions or deletions at mononucleotide repeats. Mutations were also identified in 2-8% of tumors of the pancreas, breast, brain (medulloblastomas), prostate, and lung, and none of these tumors displayed MSI. These findings suggest that the aberrant chromatin remodeling consequent to ARID1A inactivation contributes to a variety of different types of neoplasms. 相似文献