全文获取类型
收费全文 | 65212篇 |
免费 | 6525篇 |
国内免费 | 3444篇 |
专业分类
耳鼻咽喉 | 697篇 |
儿科学 | 967篇 |
妇产科学 | 450篇 |
基础医学 | 4602篇 |
口腔科学 | 1108篇 |
临床医学 | 7706篇 |
内科学 | 6583篇 |
皮肤病学 | 732篇 |
神经病学 | 1963篇 |
特种医学 | 2518篇 |
外国民族医学 | 5篇 |
外科学 | 6066篇 |
综合类 | 16075篇 |
现状与发展 | 13篇 |
一般理论 | 4篇 |
预防医学 | 7162篇 |
眼科学 | 876篇 |
药学 | 8197篇 |
70篇 | |
中国医学 | 5943篇 |
肿瘤学 | 3444篇 |
出版年
2024年 | 269篇 |
2023年 | 799篇 |
2022年 | 1906篇 |
2021年 | 2349篇 |
2020年 | 2163篇 |
2019年 | 1456篇 |
2018年 | 1498篇 |
2017年 | 1821篇 |
2016年 | 1619篇 |
2015年 | 2655篇 |
2014年 | 3393篇 |
2013年 | 4319篇 |
2012年 | 5901篇 |
2011年 | 6043篇 |
2010年 | 5404篇 |
2009年 | 4812篇 |
2008年 | 4812篇 |
2007年 | 4715篇 |
2006年 | 4146篇 |
2005年 | 3367篇 |
2004年 | 2855篇 |
2003年 | 2353篇 |
2002年 | 1878篇 |
2001年 | 1620篇 |
2000年 | 1055篇 |
1999年 | 550篇 |
1998年 | 199篇 |
1997年 | 206篇 |
1996年 | 134篇 |
1995年 | 103篇 |
1994年 | 106篇 |
1993年 | 52篇 |
1992年 | 64篇 |
1991年 | 67篇 |
1990年 | 47篇 |
1989年 | 47篇 |
1988年 | 26篇 |
1987年 | 40篇 |
1986年 | 41篇 |
1985年 | 32篇 |
1984年 | 27篇 |
1983年 | 19篇 |
1982年 | 19篇 |
1979年 | 13篇 |
1977年 | 10篇 |
1964年 | 13篇 |
1963年 | 11篇 |
1962年 | 8篇 |
1959年 | 8篇 |
1957年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
21.
Gresham T Richter Jacob E Smith Horace J Spencer Chun Y Fan Emre Vural 《Otolaryngology--head and neck surgery》2007,137(2):239-242
OBJECTIVES: Histological comparison of human-based (AlloDerm) and porcine-based (ENDURAGen) dermal matrices regarding tissue incorporation and neovascularization as potential soft tissue augmentation materials. STUDY DESIGN: In vivo, rat model. METHODS: Subcutaneous implantation of 1-mm thick, 1 cm x 1 cm pieces of AlloDerm, ENDURAGen, and meshed ENDURAGen was performed in 24 Sprague Dawley rats. Implant materials were harvested at 4 (n = 12) and 8 weeks (n = 12). Histological quantification of soft tissue ingrowth and microvascular density was performed following hematoxylin-eosin staining and CD34 immunohistochemistry, respectively. RESULTS: AlloDerm showed significantly greater soft tissue ingrowth and microvascular density compared with both ENDURAGen and meshed ENDURAGen at 4 and 8 weeks (P < 0.001). CONCLUSIONS: Although these results may differ in human host tissues, AlloDerm seems to be a more suitable dermal matrix implant than ENDURAGen for cases in which tissue incorporation and neovascularization are sought for the optimal outcome based on this animal model. 相似文献
22.
Anatomic and spiral computed tomographic study of the genial tubercles for genioglossus advancement.
Shan Kai Yin Hong Liang Yi Wen Ying Lu Jian Guan Hong Min Wu Zhen Yu Cao Dong Zhen Yu Yan Yan Huang Chun Gen Wu 《Otolaryngology--head and neck surgery》2007,136(4):632-637
OBJECTIVE: To measure and compare Chinese mandibular genial tubercles measured anatomically and with computed tomography (CT). STUDY DESIGN AND SETTING: Spiral CT scans were taken of 40 adult human skulls; the superior genial spines were measured using anatomic and CT methods. RESULTS: The height and width of the superior genial spines, mandible thickness, and distance from the menton to the inferior and superior margins of the superior genial spines were 5.82 +/- 0.71, 6.98 +/- 1.35, 11.95 +/- 1.59, 11.08 +/- 2.05, and 16.91 +/- 2.30 mm from anatomic measurements and 6.17 +/- 0.71, 7.01 +/- 1.13, 12.19 +/- 1.64, 10.41 +/- 1.55, and 15.73 +/- 2.12 mm using spiral CT, respectively. The anatomic and CT measurements were correlated. CONCLUSION: Spiral CT of the genial tubercles can help locate the osteotomy in genioglossus advancement. SIGNIFICANCE: This study acquired reference data on Chinese genial tubercles demonstrating that CT measurements of the genial tubercles reflect their anatomy, which should allow accurately locate the osteotomy. 相似文献
23.
假性甲状旁腺功能减退症1例 总被引:1,自引:0,他引:1
患儿,男,5个月,因呼吸不畅5d,门诊以先天性喉喘鸣收入院。5d前出现呼吸不畅,咽喉部有痰鸣,故入院。查体:圆脸、下颏短,前囟2.5cm×2.5cm,平坦,枕秃( ),乒乓球感( ),咽稍红,双肺呼吸音可闻及喉鸣音,未闻及干湿啰性音,心脏、腹部及神经系统未见异常。血钙1.75mmol/L,血磷1.81mmol 相似文献
24.
新生儿性传播性结膜炎40例临床诊治分析 总被引:1,自引:0,他引:1
新生儿性传播性结膜炎包括淋菌性结膜炎和非淋菌性结膜炎。现对在眼科门诊收治的58例双眼患急性结膜炎的新生儿以PCR检查证实,发现40例诊断为性传播性结膜炎,并施行相应治疗,结果报告如下。 相似文献
25.
Sulfaguanidine (Ⅰ) and sulfadimidine (Ⅱ) in infantile co-sulfadimidine powders were determined using derivative-spectrophotometry. Ⅰ and Ⅱ were extracted with 10 ml dilute HCl, and added 0.1 mol/L HC1 to 100 ml. Ⅰ was analyzed with spectrophotometry at 220 nm. Ⅱ was analyzed with derivative-spectrophotometry at 321, 324 nm. Recoveries of Ⅰ and Ⅱ were 100.2±0.33% and 100.3±0.55% respectivly. 相似文献
26.
Ion channel expression by white matter glia: I. Type 2 astrocytes and oligodendrocytes 总被引:12,自引:0,他引:12
White matter is a compact structure consisting primarily of neuronal axons and glial cells. As in other parts of the nervous system, the function of glial cells in white matter is poorly understood. We have explored the electrophysiological properties of two types of glial cells found predominantly in white matter: type 2 astrocytes and oligodendrocytes. Whole-cells and single-channel patch-clamp techniques were used to study these cell types in postnatal rat optic nerve cultures prepared according to the procedures of Raff et al. (Nature, 303:390-396, 1983b). Type 2 astrocytes in culture exhibit a "neuronal" channel phenotype, expressing at least six distinct ion channel types. With whole-cell recording we observed three inward currents: a voltage-sensitive sodium current qualitatively similar to that found in neurons and both transient and sustained calcium currents. In addition, type 2 astrocytes had two components of outward current: a delayed potassium current which activated at 0 mV and an inactivating calcium-dependent potassium current which activated at -30 mV. Type 2 astrocytes in culture could be induced to fire single regenerative potentials in response to injections of depolarizing current. Single-channel recording demonstrated the presence of an outwardly rectifying chloride channel in both type 2 astrocytes and oligodendrocytes, but this channel could only be observed in excised patches. Oligodendrocytes expressed only one other current: an inwardly rectifying potassium current that is mediated by 30- and 120-pS channels. Because these channels preferentially conduct potassium from outside to inside the cell, and because they are open at the resting potential of the cell, they would be appropriate for removing potassium from the extracellular space; thus it is proposed that oligodendrocytes, besides myelinating axons, play an important role in potassium regulation in white matter. The conductances present in oligodendrocytes suggest a "modulated Boyle and Conway mechanism" of potassium accumulation. 相似文献
27.
Yang JQ Chun T Liu H Hong S Bui H Van Kaer L Wang CR Singh RR 《European journal of immunology》2004,34(6):1723-1732
Mechanisms responsible for the development of autoimmune skin disease in humans and animal models with lupus remain poorly understood. In this study, we have investigated the role of CD1d, an antigen-presenting molecule known to activate natural killer T cells, in the development of inflammatory dermatitis in lupus-susceptible MRL-lpr/lpr mice. In particular, we have established MRL-lpr/lpr mice carrying a germ-line deletion of the CD1d genes. We demonstrate that CD1d-deficient MRL-lpr/lpr mice, as compared with wild-type littermates, have more frequent and more severe skin disease, with increased local infiltration with mast cells, lymphocytes and dendritic cells, including Langerhans cells. CD1d-deficient MRL-lpr/lpr mice had increased prevalence of CD4(+) T cells in the spleen and liver and of TCR alpha beta (+)B220(+) cells in lymph nodes. Furthermore, CD1d deficiency was associated with decreased T cell production of type 2 cytokines and increased or unchanged type 1 cytokines. These findings indicate a regulatory role of CD1d in inflammatory dermatitis. Understanding the mechanisms by which CD1d deficiency results in splenic T cell expansion and cytokine alterations, with increased dermal infiltration of dendritic cells and lymphocytes in MRL-lpr/lpr mice, will have implications for the pathogenesis of inflammatory skin diseases. 相似文献
28.
采用套式聚合酶链反应结合变性聚丙烯酰胺凝胶电泳和银染技术,并构建载脂蛋白CII(ApoCII)基因二核苷酸串联重复序列(TG)n(AG)m及(AG)m序列等位基因梯阶标准;检测正常汉族人群基因型和等位基因频率分布,检出36种(TG)n(AG)m序列基因型、12种等位基因。等位基因为17、18、26-35,其频率分别为0.061、0.011、0.002、0.002、0.054、0.255、0.372、0.084、0.026、0.039、0.052、0.041。检出7种(AG)m序列基因型、4种等位基因。等位基因为6、7、8、9,其频率分别为0.002、0.152、0.812、0.034。与欧洲白种人比较,ApoCII基因二核苷酸串联重复序列(TG)n(AG)m及(AG)m序列等位基因频率分布均具有明显的种族差异性(P<0.01,P<0.01)。 相似文献
29.
目的 分析持续性腹膜透析(PD)治疗老年慢性肾功能衰竭(CRF)患者的临床效果,探讨PD在老年CRF患者中的应用经验.方法 回顾性分析89例老年CRF患者接受PD(简称老年PD组)治疗后的临床表现和生化指标、主要并发症、存活率、死亡原因等,并与53例非老年PD组相比较.结果 老年PD组的原发疾病以糖尿病(37.08%)、原发性高血压(30.34%)为主,而非老年PD组则以肾小球肾炎(54.72%)为主.两组患者的1年与3年存活率差异无统计学意义,腹膜炎仍是两组患者退出PD的主要原因.老年组的病死率明显高于非老年组,感染与心脑血管病是两组患者的主要并发症和死亡原因.低钾血症在老年PD患者中非常普遍.结论 腹膜透析在老年CRF患者的治疗中有效,但长期存活仍受腹膜炎、心脑血管病并发症的影响,老年PD患者的低钾血症应引起足够的重视. 相似文献
30.
Byung Rae Jin Chun Jeih Ryu Sung Sup Park Namgung Uk Hyo Jeong Hong Moon Hi Han 《Molecular immunology》1993,30(18):1647-1654
The cloning, expression and characterization of a murine-human chimeric antibody with specificity for the pre-S2 surface antigen (Ag) of hepatitis B virus (HBV) is described. The heavy and light chain variable region (VH and VL) genes encoding the murine monoclonal antibody (mAb) were isolated and combined with human γ 1 and κ constant region genes, respectively. The expression vectors containing the chimeric heavy and light chain genes were sequentially electroporated into murine Sp2/0 hybridoma cells and transfectomas secreting chimeric antibody were isolated. The chimeric antibody was purified and characterized by ELISA, Western analysis and competition immunoassay, demonstrating that the transfectoma functionally express and secrete murine-human chimeric antibody which retained the specificity and affinity of the parental murine mAb. 相似文献