全文获取类型
收费全文 | 176819篇 |
免费 | 12377篇 |
国内免费 | 4233篇 |
专业分类
耳鼻咽喉 | 2416篇 |
儿科学 | 2466篇 |
妇产科学 | 2436篇 |
基础医学 | 26283篇 |
口腔科学 | 4101篇 |
临床医学 | 18272篇 |
内科学 | 29806篇 |
皮肤病学 | 4622篇 |
神经病学 | 13143篇 |
特种医学 | 9458篇 |
外国民族医学 | 37篇 |
外科学 | 22363篇 |
综合类 | 8303篇 |
现状与发展 | 10篇 |
一般理论 | 39篇 |
预防医学 | 9856篇 |
眼科学 | 4704篇 |
药学 | 16499篇 |
43篇 | |
中国医学 | 4073篇 |
肿瘤学 | 14499篇 |
出版年
2024年 | 174篇 |
2023年 | 1343篇 |
2022年 | 3767篇 |
2021年 | 7098篇 |
2020年 | 3962篇 |
2019年 | 4639篇 |
2018年 | 5510篇 |
2017年 | 4575篇 |
2016年 | 5527篇 |
2015年 | 7797篇 |
2014年 | 9386篇 |
2013年 | 10146篇 |
2012年 | 15386篇 |
2011年 | 15023篇 |
2010年 | 8950篇 |
2009年 | 7561篇 |
2008年 | 10457篇 |
2007年 | 10016篇 |
2006年 | 9153篇 |
2005年 | 8437篇 |
2004年 | 6991篇 |
2003年 | 6200篇 |
2002年 | 5360篇 |
2001年 | 4122篇 |
2000年 | 3910篇 |
1999年 | 3236篇 |
1998年 | 1543篇 |
1997年 | 1353篇 |
1996年 | 1058篇 |
1995年 | 909篇 |
1994年 | 760篇 |
1993年 | 589篇 |
1992年 | 1082篇 |
1991年 | 955篇 |
1990年 | 857篇 |
1989年 | 740篇 |
1988年 | 616篇 |
1987年 | 600篇 |
1986年 | 450篇 |
1985年 | 461篇 |
1984年 | 314篇 |
1983年 | 253篇 |
1982年 | 163篇 |
1981年 | 196篇 |
1980年 | 145篇 |
1979年 | 248篇 |
1978年 | 174篇 |
1976年 | 138篇 |
1974年 | 148篇 |
1973年 | 135篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Clinical usefulness of intraductal ultrasonography for the management of acute biliary pancreatitis 下载免费PDF全文
73.
Kanghyun Kim Kwantae Noh Janghyun Paek Kung-Rock Kwon Ahran Pae 《The journal of advanced prosthodontics》2015,7(5):406-410
Russell-Silver syndrome (RSS) is a congenital disease characterized by short stature due to growth hormone deficiency, physical asymmetry, inverted triangular face, micrognathia, prominent forehead, and hypodontia. This case report presents a prosthetic management of a 6-year-old patient with Russell-Silver syndrome treated with overdentures on the maxilla and the mandible using the remaining primary teeth. Subsequent and comprehensive dental management considering the growth and development of a young patient will be necessary. 相似文献
74.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery. 相似文献
75.
Bryan Mclaughlin JungHwan Yang Woohyun Yoo Bret Shaw Soo Yun Kim Dhavan Shah 《Health communication》2016,31(6):762-771
The growth of online support groups has led to an expression effects paradigm within the health communication literature. Although religious support expression is characterized as a typical subdimension of emotional support, we argue that in the context of a life-threatening illness, the inclusion of a religious component creates a unique communication process. Using data from an online group for women with breast cancer, we test a theoretical expression effects model. Results demonstrate that for breast cancer patients, religious support expression has distinct effects from general emotional support messages, which highlights the need to further theorize expression effects along these lines. 相似文献
76.
77.
Sheng Zhang Yan Wang Jie Xu Bokyung Kim Wenbin Deng Fuzheng Guo 《The Journal of neuroscience》2021,41(2):251
The developing CNS is exposed to physiological hypoxia, under which hypoxia-inducible factor α (HIFα) is stabilized and plays a crucial role in regulating neural development. The cellular and molecular mechanisms of HIFα in developmental myelination remain incompletely understood. A previous concept proposes that HIFα regulates CNS developmental myelination by activating the autocrine Wnt/β-catenin signaling in oligodendrocyte progenitor cells (OPCs). Here, by analyzing a battery of genetic mice of both sexes, we presented in vivo evidence supporting an alternative understanding of oligodendroglial HIFα-regulated developmental myelination. At the cellular level, we found that HIFα was required for developmental myelination by transiently controlling upstream OPC differentiation but not downstream oligodendrocyte maturation and that HIFα dysregulation in OPCs but not oligodendrocytes disturbed normal developmental myelination. We demonstrated that HIFα played a minor, if any, role in regulating canonical Wnt signaling in the oligodendroglial lineage or in the CNS. At the molecular level, blocking autocrine Wnt signaling did not affect HIFα-regulated OPC differentiation and myelination. We further identified HIFα–Sox9 regulatory axis as an underlying molecular mechanism in HIFα-regulated OPC differentiation. Our findings support a concept shift in our mechanistic understanding of HIFα-regulated CNS myelination from the previous Wnt-dependent view to a Wnt-independent one and unveil a previously unappreciated HIFα–Sox9 pathway in regulating OPC differentiation.SIGNIFICANCE STATEMENT Promoting disturbed developmental myelination is a promising option in treating diffuse white matter injury, previously called periventricular leukomalacia, a major form of brain injury affecting premature infants. In the developing CNS, hypoxia-inducible factor α (HIFα) is a key regulator that adapts neural cells to physiological and pathologic hypoxic cues. The role and mechanism of HIFα in oligodendroglial myelination, which is severely disturbed in preterm infants affected with diffuse white matter injury, is incompletely understood. Our findings presented here represent a concept shift in our mechanistic understanding of HIFα-regulated developmental myelination and suggest the potential of intervening with an oligodendroglial HIFα-mediated signaling pathway to mitigate disturbed myelination in premature white matter injury. 相似文献
78.
79.
Ling Zhang Xue-Jun Shang Hong-Fei Li Yu-Qin Shi Wei Li Maria E Teves Zhi-Qiong Wang Gao-Feng Jiang Shi-Zhen Song Zhi-Bing Zhang 《Asian journal of andrology》2015,17(1):86-93
Mammalian spermatogenesis is a well-organized process of cell development and differentiation. Meiosis expressed gene 1 (MEIG1) plays an essential role in the regulation of spermiogenesis. To explore potential mechanisms of MEIG1''s action, a yeast two-hybrid screen was conducted, and several potential binding partners were identified; one of them was membrane occupation and recognition nexus repeat containing 3 (MORN3). MORN3 mRNA is only abundant in mouse testis. In the testis, Morn3 mRNA is highly expressed in the spermiogenesis stage. Specific anti-MORN3 polyclonal antibody was generated against N-terminus of the full-length MORN3 protein, and MORN3 expression and localization was examined in vitro and in vivo. In transfected Chinese hamster ovary cells, the antibody specifically crossed-reacted the full-length MORN3 protein, and immunofluorescence staining revealed that MORN3 was localized throughout the cytoplasm. Among multiple mouse tissues, about 25 kDa protein, was identified only in the testis. The protein was highly expressed after day 20 of birth. Immunofluorescence staining on mixed testicular cells isolated from adult wild-type mice demonstrated that MORN3 was expressed in the acrosome in germ cells throughout spermiogenesis. The protein was also present in the manchette of elongating spermatids. The total MORN3 expression and acrosome localization were not changed in the Meig 1-deficient mice. However, its expression in manchette was dramatically reduced in the mutant mice. Our studies suggest that MORN3 is another regulator for spermatogenesis, probably together with MEIG1. 相似文献
80.