全文获取类型
收费全文 | 8310篇 |
免费 | 783篇 |
国内免费 | 395篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 100篇 |
妇产科学 | 56篇 |
基础医学 | 765篇 |
口腔科学 | 105篇 |
临床医学 | 1128篇 |
内科学 | 1116篇 |
皮肤病学 | 102篇 |
神经病学 | 408篇 |
特种医学 | 251篇 |
外科学 | 969篇 |
综合类 | 1560篇 |
现状与发展 | 2篇 |
一般理论 | 1篇 |
预防医学 | 537篇 |
眼科学 | 205篇 |
药学 | 942篇 |
10篇 | |
中国医学 | 644篇 |
肿瘤学 | 498篇 |
出版年
2024年 | 33篇 |
2023年 | 182篇 |
2022年 | 375篇 |
2021年 | 477篇 |
2020年 | 337篇 |
2019年 | 276篇 |
2018年 | 280篇 |
2017年 | 279篇 |
2016年 | 244篇 |
2015年 | 383篇 |
2014年 | 487篇 |
2013年 | 467篇 |
2012年 | 603篇 |
2011年 | 550篇 |
2010年 | 389篇 |
2009年 | 325篇 |
2008年 | 417篇 |
2007年 | 452篇 |
2006年 | 428篇 |
2005年 | 386篇 |
2004年 | 275篇 |
2003年 | 275篇 |
2002年 | 244篇 |
2001年 | 183篇 |
2000年 | 206篇 |
1999年 | 183篇 |
1998年 | 105篇 |
1997年 | 91篇 |
1996年 | 92篇 |
1995年 | 84篇 |
1994年 | 60篇 |
1993年 | 29篇 |
1992年 | 35篇 |
1991年 | 40篇 |
1990年 | 35篇 |
1989年 | 37篇 |
1988年 | 26篇 |
1987年 | 25篇 |
1986年 | 25篇 |
1985年 | 8篇 |
1984年 | 11篇 |
1983年 | 8篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1977年 | 3篇 |
1973年 | 3篇 |
1971年 | 4篇 |
1969年 | 3篇 |
1967年 | 2篇 |
1958年 | 2篇 |
排序方式: 共有9488条查询结果,搜索用时 0 毫秒
51.
Nadine C. Milos Yanling Ma Parag V. Varma Michael P. Bering Zarina Mohamed Linda M. Pilarski Yvette N. Frunchak 《Anatomy and embryology》1990,182(4):319-327
Summary A monoclonal antibody has been produced againstXenopus laevis galactoside-binding neural-creststage lectin. This antibody inhibits lectin-mediated hemagglutination. Using this antibody
in conjunction with immunohistochemical techniques, lectin deposition has been studied in embryos and tadpoles at different
stages of morphogenesis, from initial neural crest migration, up to the formation of a swimming tadpole. Lectin levels change
during development in different regions of the embryo and tadpole, decreasing in migratory cells, and increasing in sites
where cells become more adhesive to one another. The results suggest that galactoside-binding lectins may be an important
class of cellular adhesion molecules during these stages of development. 相似文献
52.
Saheki T Kobayashi K Iijima M Horiuchi M Begum L Jalil MA Li MX Lu YB Ushikai M Tabata A Moriyama M Hsiao KJ Yang Y 《Molecular genetics and metabolism》2004,81(Z1):S20-S26
Citrin is a mitochondrial aspartate glutamate carrier primarily expressed in the liver, heart, and kidney. We found that adult-onset type II citrullinemia is caused by mutations in the SLC25A13 gene that encodes for citrin. In this report, we describe the frequency of SLC25A13 mutations, the roles of citrin as a member of the urea cycle and as a member of the malate-aspartate shuttle, the relationship between its functions and symptoms of citrin deficiency, and therapeutic issues. 相似文献
53.
Shepp-Logan头部模型是计算机断层图像重建(CT)领域仿真计算普遍采用的经典模型。我们提出一种新思路—以3D Shepp-Logan头部模型作为三维医学图像重建领域进行仿真实验和算法性能评测的基本参考模型。首先介绍了3D Shepp-Logan头部模型的设计与实现以及仿真投影数据的计算,进而描述了所设计的三维医学图像重建仿真计算过程。数值实验部分给出了基于3D Shepp-Logan头部模型的三维医学图像重建仿真实验。实验结果表明了新思路的可行性和模型计算的准确性。 相似文献
54.
行为问题儿童的生活质量及其影响因素调查 总被引:18,自引:0,他引:18
目的:探讨行为问题儿童的生活质量及影响因素.方法:采用Conners量表和儿少主观生活质量问卷调查2087例少年儿童的行为问题和生活质量,然后将问题儿童与正常儿童的结果做比较.结果:行为问题儿童的生活质量明显低于正常儿童,相关分析显示儿少主观生活质量问卷与Conners量表父母问卷和教师评定量表的部分因子存在不同程度的相关.逐步回归显示儿童的学业、行为问题、家庭经济、父亲性格、年龄、父母对不良行为的处理方式、独生共7个变量影响着儿童的生活质量.结论:行为问题儿童生活质量下降,需要得到学校、家庭、同伴、社会等多方面的关怀帮助. 相似文献
55.
Maoxin Wu Lurmag Orta Joan Gil Gan Li Alice Hu David E Burstein 《Modern pathology》2008,21(5):553-558
The critical distinction of bronchioloalveolar carcinoma (BAC), well-differentiated adenocarcinoma (WDAC) of lung, adenomatous hyperplasia (AH) and atypical adenomatous hyperplasia (AAH), is based on morphological criteria alone, and is therefore potentially subjective. We examined expression of two markers, X-linked inhibitor of apoptosis protein (XIAP), the most potent of the inhibitor of apoptosis protein (IAP) family, and p63, a marker of bronchial reserve cells (BRC) and squamous cells, in these entities. H&E slides of 37 tissue blocks from 27 patients were reviewed and classified as AH (n=7), AAH (n=8), BAC (n=9) and WDAC (n=13). Immunostaining was performed on 4 mum sections with monoclonal anti-XIAP and monoclonal anti-p63. Granular or heterogeneous cytoplasmic staining for XIAP and nuclear staining for p63 were considered positive. Neither XIAP nor p63 were detected in normal lung alveolar cells. All seven AHs were negative for XIAP and negative or focally positive for p63. All eight AAHs were positive for XIAP and displayed p63 positivity in scattered cells. All BACs displayed XIAP positivity, which ranged from focal/weak to diffuse/strong. p63 was negative in seven and focally positive in two of nine BACs. Twelve of 13 WDACs showed XIAP positivity in a similar pattern to BAC; all were negative for p63. One aberrant case diagnosed on H & E as WDAC was negative for XIAP but strongly positive for p63. Significant XIAP expression appears to be useful for distinguishing AAH from AH. Commonality of XIAP staining in AAH, BAC and WDAC supports the possibility that AAH may be a pre-malignant lesion. The rarity of p63 expression confirms previous reports and supports a nonbronchial histogenesis of these entities. In contrast, diffuse p63 staining may facilitate the identification of rare cases that may have been misclassified as alveolar in origin based on morphology but may be of BRC origin. 相似文献
56.
The pattern and frequency of t(14;18) translocation and immunophenotype in Asian follicular lymphoma 总被引:2,自引:0,他引:2
AIMS: Follicular lymphoma is frequently associated with t(14;18)(q32;q21) translocation. This study was undertaken to determine the pattern of Bcl-2, CD10 and Bcl-6 expression in relation to t(14;18) translocation in follicular lymphoma from a cohort of a multi-ethnic Asian population. METHODS AND RESULTS: Sixty-two cases of follicular lymphoma were retrieved for immunohistochemistry, and t(14;18) translocation analysis by polymerase chain reaction and fluorescent in-situ hybridization techniques. Bcl-2 expression was present in 74% of the cases. CD10 expression was also relatively low (61%), with decreasing frequency of expression in high-grade tumours. Bcl-6 protein was expressed in most of the tumours (88%) regardless of the tumour grade. The t(14;18) translocation was detected in 46 cases (74%) with an extremely high rate of t(14;18) translocation in ethnic Indian cases (100%). CONCLUSION: The frequency of t(14;18) translocation in this series of follicular lymphomas was higher when compared with previous Asian reports, but in accordance with European and North American findings. CD10 expression is strongly associated with a t(14;18) translocation event, but the overall CD10 expression was relatively low, possibly due to the high proportion of high-grade tumours in the series. t(14;18) translocation was not associated with Bcl-2 or Bcl-6 expression. 相似文献
57.
目的 探讨术前颈椎过伸功能与颈椎后路单开门椎管扩大成形术后前凸角度丢失的关系。方法 回顾性分析首都医科大学大兴教学医院骨科2017年1月-2018年12月58例行颈椎后路单开门椎管扩大成形术患者临床资料,其中男45例、女13例,年龄49~85岁(平均64.8岁)。术前测量患者中立侧位X线片上的T1倾斜角、矢状面垂直轴(SVA),以及中立侧位、过伸位X线片的C2~C7 Cobb角。随访12~24个月,术后再次测量中立侧位X线片上的C2~C7 Cobb角。术前颈椎过伸功能测量值为术前过伸位X线片C2~C7 Cobb角度减去术前中立侧位X线片C2~C7 Cobb角。前凸角度丢失量为术前中立侧位片C2~C7 Cobb角减去末次随访时中立侧位片C2~C7 Cobb角。依据58例患者术前颈椎过伸功能均值(8.7°)分为两组,≥8.7°为A组,<8.7°为 B 组。比较两组患者术前及术后影像及临床资料,同时对58例患者的影像学资料与临床资料进行相关性分析。结果 A组25例患者年龄54~83岁,B组33例患者年龄49~85岁,两组患者术前年龄、性别、疾病种类差异均无统计学意义(P值均>0.05)。术前A组颈椎过伸功能(14.09°±4.75°)大于B组(4.62°±2.54°),A组T1倾斜角(17.00°±3.40°)小于B组(29.68°±6.34°),颈椎前凸角度丢失[1.10(-0.85,4.00)]小于B组[8.60 (7.70,12.40)],差异均有统计学意义(P值均<0.01)。颈椎过伸功能与前凸角度丢失之间呈负相关(r=-0.965, P<0.01),T1倾斜角与前凸角度丢失之间呈正相关(r=0.954, P<0.01),颈椎过伸功能与T1倾斜角呈负相关(r=-0.900, P<0.01);SVA与T1倾斜角、颈椎过伸功能、术后前凸角度丢失均无相关性(r=-0.065、0.216、-0.202, P>0.05)。术后JOA评分改善率与过伸角度变化、SVA及T1倾斜角均无相关性(r=0.201、-0.034、-0.213, P值均>0.05)。A组术后JOA改善率为69%±23%,B 组术后JOA改善率为62%±23%,两组差异无统计学意义(t=1.147, P>0.05)。术后Odom's分级评价A组优良率为88.0%(22/25),B组优良率为63.6%(21/33),差异有统计学意义(χ2 =4.403, P<0.05)。结论 对于后路单开门椎管扩大成形术患者,颈椎过伸功能与前凸角度丢失存在相关性,术前过伸功能越低,术后越易发生前凸角度丢失,可作为术前预判术后颈椎曲度变化的参数之一。 相似文献
58.
Photodynamic therapy (PDT) is a clinical approach that utilizes light-activated drugs for the treatment of a variety of pathologic conditions. Human poorly (CNE2) and moderately differentiated (TW0-1) human nasopharyngeal carcinoma (NPC) cells undergo rapid apoptosis when treated with PDT sensitized with Hypocrellin A (HA) and Hypocrellin B (HB). It has been shown that these compounds have a strong photodynamic effect on tumors and viruses. The initiating events of PDT sensitized HA and HB-induced apoptosis are poorly defined. In the current study, we sought to determine whether Fas/FasL upregulation and involvement of mitochondrial events are an early event in HA and HB-treated PDT induced apoptosis. Loss of mitochondrial transmembrane potential, release of cytochrome c, involvement of caspases-8 and -3 and the status caspase-3 specific substrate PARP, were evaluated in PDT treated tumor cells. Photoactivation of HA and HB enhanced both CD95/CD95L expression and induced CD95-signaling dependent cell death in all tumor cell lines studied. CD95/ CD95L expression appeared within 2 h following light activation and appeared to be a primary event in PDT induced apoptosis. Furthermore, these results indicate that release of mitochondrial cytochrome c into the cytoplasm is a secondary event following the activation of initiator caspase-8 preceding caspase-3 activation, cleavage of PARP and DNA fragmentation. Cytochrome c appeared in the cytosol within 2-3 h post PDT. Cleavage of PARP was observed at 3-4 h following PDT and caspase-3 specific inhibitor DEVD-CHO and broad-spectrum caspases inhibitor z-VAD-fmk blocked caspase-3 activation and PARP cleavage suggesting that caspase-3 plays an important role in HA and HB-induced apoptosis. 相似文献
59.
60.
针对护理心理学的学科属性和成人高等护理教育的特点,结合8年来护理心理学的教学经验,总结出了教学应强调专业教育和素质教育相结合,努力提高护理心理学教育的整体水平。 相似文献