全文获取类型
收费全文 | 16124篇 |
免费 | 1468篇 |
国内免费 | 944篇 |
专业分类
耳鼻咽喉 | 147篇 |
儿科学 | 161篇 |
妇产科学 | 283篇 |
基础医学 | 2003篇 |
口腔科学 | 265篇 |
临床医学 | 2139篇 |
内科学 | 2600篇 |
皮肤病学 | 182篇 |
神经病学 | 842篇 |
特种医学 | 561篇 |
外国民族医学 | 5篇 |
外科学 | 1912篇 |
综合类 | 2134篇 |
现状与发展 | 1篇 |
一般理论 | 6篇 |
预防医学 | 1071篇 |
眼科学 | 484篇 |
药学 | 1645篇 |
15篇 | |
中国医学 | 742篇 |
肿瘤学 | 1338篇 |
出版年
2024年 | 45篇 |
2023年 | 242篇 |
2022年 | 576篇 |
2021年 | 792篇 |
2020年 | 551篇 |
2019年 | 550篇 |
2018年 | 554篇 |
2017年 | 502篇 |
2016年 | 490篇 |
2015年 | 713篇 |
2014年 | 868篇 |
2013年 | 813篇 |
2012年 | 1163篇 |
2011年 | 1166篇 |
2010年 | 845篇 |
2009年 | 656篇 |
2008年 | 771篇 |
2007年 | 786篇 |
2006年 | 823篇 |
2005年 | 762篇 |
2004年 | 635篇 |
2003年 | 610篇 |
2002年 | 566篇 |
2001年 | 446篇 |
2000年 | 385篇 |
1999年 | 392篇 |
1998年 | 272篇 |
1997年 | 240篇 |
1996年 | 179篇 |
1995年 | 181篇 |
1994年 | 114篇 |
1993年 | 97篇 |
1992年 | 108篇 |
1991年 | 93篇 |
1990年 | 72篇 |
1989年 | 69篇 |
1988年 | 65篇 |
1987年 | 62篇 |
1986年 | 42篇 |
1985年 | 42篇 |
1984年 | 22篇 |
1983年 | 14篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 21篇 |
1976年 | 10篇 |
1974年 | 15篇 |
1973年 | 13篇 |
1972年 | 10篇 |
1969年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 10 毫秒
81.
Yuan Feng Wan Dai Junyu Ke Yong Cui Shuang Li Jingjing Ma Wenfeng Guo Gang Chen Ning Li Yanwu Li 《Pharmaceutical biology》2022,60(1):1095
ContextValerian extract capsule (VEC) is an effective Chinese patent medicine used for gastrointestinal (GI) diseases.ObjectiveTo investigate the detailed pharmacological activity for VEC clinical effects in GI diseases.Materials and methodsSprague-Dawley rats were divided into six groups: control, model, and drug-treated (VEC-L, VEC-M, VEC-H, and teprenone). Rats were orally administered VEC (124, 248, 496 mg/kg) and teprenone (21.43 mg/kg) for 3 consecutive days. After 1 h, the five groups (except the control group) were orally given ethanol (10 mL/kg) for 1 h or indomethacin (80 mg/kg) for 7 h. The spasmolytic activity of VEC (0.01–1 mg/mL) on ACh/BaCl2-induced New Zealand rabbit smooth muscle contraction was performed. The C57BL/6 mice carbon propelling test evaluated the effects of VEC (248–992 mg/kg) on intestinal motility in normal and neostigmine/adrenaline-induced mice.ResultsCompared with the model group, VEC treatment reduced the gastric lesion index and mucosal damage. Further experiments showed that the pathological ameliorative effect of VEC was accompanied by augmentation of the enzymatic antioxidant system and cytoprotective marker (COX-1, p < 0.01; PGI2 p < 0.05;), along with the alleviation of the levels of MPO (ethanol: 15.56 ± 0.82 vs. 12.15 ± 2.60, p < 0.01; indomethacin: 9.65 ± 3.06 vs. 6.36 ± 2.43, p < 0.05), MDA (ethanol: 1.66 ± 0.44 vs. 0.81 ± 0.58, p < 0.01; indomethacin: 1.71 ± 0.87 vs. 1.09 ± 0.43, p < 0.05), and inflammatory mediators. VEC decreased the high tone induced by ACh/BaCl2 and promoted intestinal transit in normal and neostigmine/adrenaline-induced mice.Discussion and conclusionsVEC showed a potential gastroprotective effect, suggesting that VEC is a promising phytomedicine for the treatment of GI diseases. 相似文献
82.
V. Bharath V. Auradi G. B. Veeresh Kumar Madeva Nagaral Murthy Chavali Mahmoud Helal Rokayya Sami NI Aljuraide Jong Wan Hu Ahmed M. Galal 《Materials》2022,15(12)
The paper focused on an experimental study on the microstructural, mechanical, and wear characteristics of 15 wt.% alumina (Al2O3) particulates with an average particle size of 20 µm, reinforced in Al2014 alloy matrix composite as-cast and heat-treated samples. The metal matrix composite (MMC)samples were produced via a novel two-stage stir-casting technique. The fabricated composite samples were subjected to evaluate hardness, tensile strength, fatigue behavior and wear properties for both as cast and T6 heat-treated test samples. The Al2014 alloy and Al2014-15 wt.% Al2O3 MMCs were in solution for 1 h at a temperature of 525 °C, quenched instantly in cold water, and then artificially aged for 10 h at a temperature of 175 °C. SEM and X-ray diffraction analyses were used to investigate the microstructure and dispersion of the reinforced Al2O3 particles in the composite and the base alloy Al2014. The obtained results indicated that the hardness, tensile and fatigue strength and wear resistance increased when an amount of Al2O3 particles was added, compared to the as-cast Al2014 alloy and it was observed that after subjecting the same composite samples to heat treatment, there was further enhancement in the mechanical and wear properties in the Al2014 matrix alloy and Al2014-15 wt.% Al2O3 composite samples. 相似文献
83.
Derong Feng Chenxi Dong Yunpeng Hu Yamei Wang Jianhua Ma Zhangdong Huang Qiang Wan 《Materials》2022,15(12)
Fracture during the assembly process is an important failure mode for high-lock bolts used in the aviation industry, which greatly increases the potential of unpredictable accidents during service. In the current study, the underlying reasons for fracture during the assembly of a TC4 high-lock bolt was investigated using a tensile test and finite element analysis (FEA). The microstructure of the as-received bolt consisted of a high proportion of α phase, some β phase, and a small amount of α′ phase formed via martensite phase transformation during the rammer process. The experimental force–displacement curves revealed an average yield load of 55.9 kN and a breaking load of 67.65 kN. The corresponding yield strength was calculated to be 0.9 GPa, which was smaller than the standard value of TC4. This was attributed to the preload-induced stress concentration on the thread surface, leading to obvious strain hardening, which can lead to crack initiation. The effect of preload was further confirmed by the fractographies in which the initial crack was observed on the thread surface. The fractographies suggested that hybrid fracture occurred on the tensile loaded bolt. The initial failure was brittle fracture on the thread surface, transforming into ductile fracture in the screw. The results can contribute to understanding the effect of preload on the load carry capacity of high-lock bolts and provide a strategy to design its assembly specification. 相似文献
84.
詹皖 《南通大学学报(哲学社会科学版)》2006,22(1):98-100
扬琴是一种有着广泛的世界性和民族性的击弦乐器,于明代自国外传至中国。四百多年采扬琴在中国传统音乐文化环境的影响下,不断和民间音乐融合,并在一代代的扬琴艺人的探索和创新中,发展成了具有中国特色的民族乐器,成为世界扬琴三大体系之一的中国扬琴体系,同时形成了中国传统扬琴的四大流派。 相似文献
85.
Sarah Zulkifli Noor Shafina Mohd Nor Siti Hamimah Sheikh Abdul Kadir Norashikin Mohd Ranai Noor Kaslina Mohd Kornain Wan Nor Izzah Wan Mohd Zain Mardiana Abdul Aziz 《Nutrients》2022,14(12)
In this study, we aimed to determine whether a postnatal trans fat diet (TFD) could aggravate prenatal bisphenol A (BPA) exposure effects on offspring’s small intestine and adulthood obesity, due to the relatively sparse findings on how the interaction between these two variables interrupt the small intestinal cells. Twelve pregnant rats were administered with either unspiked drinking water (control; CTL) or BPA-spiked drinking water throughout pregnancy. Twelve weaned pups from each pregnancy group were then given either a normal diet (ND) or TFD from postnatal week (PNW) 3 until PNW14, divided into control offspring on normal diet (CTL-ND), BPA-exposed offspring on normal diet (BPA-ND), control offspring on trans fat diet (CTL-TFD), and BPA offspring on trans fat diet (BPA-TFD) groups. Body weight (BW), waist circumference, and food and water intake were measured weekly in offspring. At PNW14, small intestines were collected for global DNA methylation and histological analyses. Marked differences in BW were observed starting at PNW9 in BPA-TFD (389.5 ± 10.0 g; p < 0.05) relative to CTL-ND (339.0 ± 7.2 g), which persisted until PNW13 (505.0 ± 15.6 g). In contrast, water and food intake between offspring were significantly different (p < 0.01–0.05) at earlier ages only (PNW4–6 and PNW7–9, respectively). Furthermore, substantial differences in the general parameters of the intestinal structures were exclusive to ileum crypt length alone, whereby both BPA-ND (150.5 ± 5.1 μm; p < 0.001), and BPA-TFD (130.3 ± 9.9 μm; p < 0.05) were significantly longer than CTL-ND (96.8 ± 8.9 μm). Moreover, BPA-ND (2.898 ± 0.147%; p < 0.05) demonstrated global small intestinal hypermethylation when compared to CTL-ND and CTL-TFD (1.973 ± 0.232% and 1.913 ± 0.256%, respectively). Prenatal BPA exposure may significantly affect offspring’s physiological parameters and intestinal function. Additionally, our data suggest that there might be compensatory responses to postnatal TFD in the combined BPA prenatal group (BPA-TFD). 相似文献
86.
植物多糖对家兔动脉粥样硬化脂质过氧化及炎症反应的干预 总被引:1,自引:0,他引:1
目的:探讨枸杞多糖、黄芪多糖对家兔动脉粥样硬化(As)脂质过氧化及炎症反应的干预机制。方法:将48只雄性新西兰大白兔随机分为4组:正常组(12只),As模型组(12只),枸杞多糖(LBP)治疗组和黄芪多糖(APS)治疗组。10周后,测定各组空腹甘油三酯(TG)、总胆固醇(TCh)、高密度脂蛋白胆固醇(HDL-C)、一氧化氮(NO)、丙二醛(MDA)、C反应蛋白(CRP)、内皮素-1(ET-1)的含量以及超氧化物歧化酶(SOD)活性,并计算HDL-C/TCh,同时计算主动脉内膜粥样斑块面积。结果:模型组与正常组比较,TG、TCh、ET-1、NO、CRP、MDA明显升高(P<0.01),HDL-C/TCh、SOD活性明显下降(P<0.01),主动脉内膜粥样斑块面积较大;而LBP和APS治疗组与模型组比较,TG、ET-1、NO、CRP明显下降(P<0.01),HDL-C/TCh和SOD活性明显升高(P<0.01),主动脉内膜粥样斑块面积明显减少(P<0.01)。结论:枸杞多糖和黄芪多糖对动脉粥样硬化有明显的预防和治疗作用,机制可能与降低血脂、抗氧化、调节免疫等功能有关。 相似文献
87.
Yun Yang Zheng Dang Peng Lu Youwen Qian Kongying Lin Zeya Pan Wan Yee Lau Weiping Zhou 《肝胆外科与营养》2022,11(3):386
BackgroundTo study the influence of pathological responses (PR) after transcatheter arterial chemoembolization (TACE) on incidences of microvascular invasion (MVI) and early recurrence in hepatocellular carcinoma (HCC) patients.MethodsBetween 2013 to 2015, consecutive HCC patients who underwent liver resection with “curative” intent at three hospitals were enrolled in this study. Patients with different areas of PR after preoperative TACE were compared with those without preoperative TACE on the incidences of MVI, early recurrence rates and patterns of recurrence before and after propensity score matching (PSM).ResultsOf 1,970 patients, 737 patients who received preoperative TACE were divided into three groups according to the areas of PR: ≥90% (n=226), 60–90% (n=447), and <60% (n=64). PR ≥90% was an independent protective factor of incidences of MVI [odds ratio (OR), 0.144; 95% confidence interval (CI), 0.082–0.245, P<0.001) and early recurrence (HR, 0.742; 95% CI, 0.561–0.963, P=0.032); while PR<60% was an independent risk factor of incidences of MVI (OR, 6.076; 95% CI, 3.004–11.728, P<0.001) and early recurrence (HR, 1.428; 95% CI, 1.095–1.929; P=0.009). Furthermore, patients with PR <60% were significantly more likely to develop multiple intrahepatic recurrences involving multiple hepatic segments when compared with patients without preoperative TACE.ConclusionsThis study indicated the area of PR after TACE was closely associated with the incidences of MVI and early tumor recurrence. Patients with PR <60% were at significantly higher risks of having more MVI, early and multiple tumor recurrences 相似文献
88.
Miaomiao Han Jingyu Ma Suidong Ouyang Yanyan Wang Tingting Zheng Peishan Lu Zihan Zheng Weiheng Zhao Hongjin Li Yun Wu Baohua Zhang Ran Hu Kinya Otsu Xinguang Liu Ying Wan Huabin Li Gonghua Huang 《Cellular & molecular immunology》2022,19(7):805
Dendritic cells (DCs) play a critical role in controlling T helper 2 (Th2) cell-dependent diseases, but the signaling mechanism that triggers this function is not fully understood. We showed that p38α activity in DCs was decreased upon HDM stimulation and dynamically regulated by both extrinsic signals and Th2-instructive cytokines. p38α-specific deletion in cDC1s but not in cDC2s or macrophages promoted Th2 responses under HDM stimulation. Further study showed that p38α in cDC1s regulated Th2-cell differentiation by modulating the MK2−c-FOS−IL-12 axis. Importantly, crosstalk between p38α-dependent DCs and Th2 cells occurred during the sensitization phase, not the effector phase, and was conserved between mice and humans. Our results identify p38α signaling as a central pathway in DCs that integrates allergic and parasitic instructive signals with Th2-instructive cytokines from the microenvironment to regulate Th2-cell differentiation and function, and this finding may offer a novel strategy for the treatment of allergic diseases and parasitic infection. 相似文献
89.
90.
目的 :建立青藤碱的透皮吸收研究方法 ,比较青藤碱渗透小鼠皮肤、裸鼠皮肤、家兔皮肤、大鼠皮肤、猪耳皮肤及人体皮肤的透皮吸收行为。方法 :青藤碱的含量测定采用HPLC法 ,计算透皮速率常数J,比较青藤碱渗透上述 6种实验皮肤的透皮速率常数。结果 :青藤碱透过 6种皮肤的透皮速率常数分别为 46 6 7± 16 35、40 34± 8 40、17 6 0± 9 46、2 3 71± 8 79、44 5 6± 11 2 7、38 33± 13 81。结论 :青藤碱对 6种皮肤的渗透性 ,以裸鼠及猪耳皮肤的透皮速率常数与人体皮肤较为接近。 相似文献