全文获取类型
收费全文 | 47675篇 |
免费 | 4520篇 |
国内免费 | 3629篇 |
专业分类
耳鼻咽喉 | 298篇 |
儿科学 | 433篇 |
妇产科学 | 482篇 |
基础医学 | 5638篇 |
口腔科学 | 755篇 |
临床医学 | 6905篇 |
内科学 | 7470篇 |
皮肤病学 | 586篇 |
神经病学 | 2602篇 |
特种医学 | 1922篇 |
外国民族医学 | 23篇 |
外科学 | 4379篇 |
综合类 | 7708篇 |
现状与发展 | 15篇 |
一般理论 | 7篇 |
预防医学 | 2922篇 |
眼科学 | 1467篇 |
药学 | 5021篇 |
81篇 | |
中国医学 | 2840篇 |
肿瘤学 | 4270篇 |
出版年
2024年 | 152篇 |
2023年 | 857篇 |
2022年 | 2037篇 |
2021年 | 2617篇 |
2020年 | 1963篇 |
2019年 | 1650篇 |
2018年 | 1761篇 |
2017年 | 1513篇 |
2016年 | 1457篇 |
2015年 | 2169篇 |
2014年 | 2637篇 |
2013年 | 2337篇 |
2012年 | 3464篇 |
2011年 | 3886篇 |
2010年 | 2366篇 |
2009年 | 1851篇 |
2008年 | 2473篇 |
2007年 | 2546篇 |
2006年 | 2475篇 |
2005年 | 2569篇 |
2004年 | 1486篇 |
2003年 | 1332篇 |
2002年 | 1109篇 |
2001年 | 1101篇 |
2000年 | 1151篇 |
1999年 | 1212篇 |
1998年 | 790篇 |
1997年 | 803篇 |
1996年 | 619篇 |
1995年 | 569篇 |
1994年 | 514篇 |
1993年 | 300篇 |
1992年 | 378篇 |
1991年 | 309篇 |
1990年 | 282篇 |
1989年 | 242篇 |
1988年 | 230篇 |
1987年 | 208篇 |
1986年 | 154篇 |
1985年 | 110篇 |
1984年 | 50篇 |
1983年 | 38篇 |
1982年 | 19篇 |
1981年 | 12篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1966年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Mingfang Zhou Haodong Cai Wei Yi Xuesong Gao 《International journal of medical sciences》2023,20(2):247
Background: The aim of the present study was to investigate the association between alanine aminotransferase (ALT) levels at delivery and postpartum ALT flares among women with chronic hepatitis B (CHB).Methods: Pregnant women with CHB from November 2008 to November 2017 were included in this retrospective study. Multivariable logistic regression analysis and a generalized additive model were performed to determine both linear and nonlinear relationships between ALT levels at delivery and postpartum ALT flares. Stratification analysis was performed to test for effect modifications in subgroups.Results: A total of 2643 women were enrolled. Multivariable analysis indicated that ALT levels at delivery were positively associated with postpartum ALT flares (odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01-1.02, P < 0.0001). When ALT levels were converted to a categorical variable, the ORs and 95% CIs in quartiles 3 and 4 versus quartile 1 were 2.26 (1.43-3.58) and 5.34 (3.48-8.22), respectively (P for trend < 0.001). When ALT levels were dichotomized into a categorical variable according to clinical cutoffs (40 U/L or 19 U/L), the ORs and 95% CIs were 3.06 (2.05-4.57) and 3.31 (2.53-4.35), respectively (P < 0.0001). The ALT level at delivery was also found to have a nonlinear relationship with postpartum ALT flares. The relationship followed an inverted U-shaped curve.Conclusions: The ALT level at delivery was positively correlated with postpartum ALT flares in women with CHB when the ALT level was less than 182.8 U/L. The ALT cutoff (19 U/L) at delivery was more sensitive to predict the risk of ALT flares postpartum. 相似文献
992.
目的:对动物药材DNA提取方法进行优化,利用优化方法提取市售动物药材DNA并进行DNA条形码鉴定。方法:基于SDS法DNA提取原理,比较裂解液中不同EDTA浓度(0.025、0.25、0.5 mol·L-1)、是否含NaCl和Triton X-100等因素对不同用药部位动物药材DNA提取质量的影响,筛选得到最佳裂解液配方;使用优化的裂解液配方提取121份市售动物药材DNA并进行基原物种鉴定。结果:裂解液配方为1 % SDS、0.03 mol·L-1 Tris-HCl、0.25 mol·L-1 EDTA、0.2 mol·L-1NaCl对不同用药部位动物药材DNA提取效果最佳,并可实现对蝉蜕等提取困难样本DNA的提取;利用优化裂解液提取的121份市售动物药材DNA满足中药材分子鉴定后续实验要求,所有市售动物药材均可准确鉴定到基原物种。结论:本研究优化的裂解液配方可用于除壳类、分泌物类、加工品外不同用药部位动物药材的DNA提取,为动物药材分子鉴定提供了技术支持。 相似文献
993.
目的:探讨不同炮制方法对补骨脂中抗骨质疏松有效成分含量的影响。方法:采用HPLC法测定补骨脂生品及不同炮制品中香豆素类、黄酮类、单萜酚类抗骨质疏松效应成分的含量,对炮制前后三类成分的含量进行统计分析。结果:补骨脂经不同方法炮制后三类成分含量与生品相比均有极显著变化。结论: 药典收载的炮制法可同时提高三类化合物的含量,可能增强其治疗骨质疏松的作用,与中医认为“盐炙能增强温补脾肾的作用”的传统观念相吻合。 相似文献
994.
随着临床实践及现代科技的发展,经典的随机对照试验已不能满足人们需要,尤其是在中医药研究领域。而与此同时,旨在获得更加符合临床实际证据的真实世界研究(Real World Study,RWS)因具有更广泛的应用前景而受到越来越多的关注。本文简述了RWS的概念及RWS需较大的样本量以覆盖较全面的人群、无严格的纳入及排除标准、根据患者的实际病情和意愿选用不同措施而不采用随机分配的方式、关注的结局是与临床密切相关的终点事件及患者的生活质量、需要长期的随访观察等特点,分析了RWS在临床中的应用现况,以此为基础,对RWS在中医药临床研究中的应用进行了展望,以期为中医药研究者们提供新的思路。 相似文献
995.
中药品种来源于经、验方,在临床实践中不断加以创新和发展并通过药材和工艺技术控制等手段不断保持完善。现行中药品种保护制度与现阶段中药的自身发展规律有不相适应之处,忽视了对传统经、验方、院内中药制剂、药材的道地性、生产工艺的有效规制,缺乏相应的企业投入回报机制。建议设立传统中药保护名录,将院内中药制剂纳入保护范畴,严格规制药材的道地性,引入药品数据保护理念,进一步完善中药品种保护制度。 相似文献
996.
藏医将人体的经脉分为黑脉和白脉。藏医认为因季节环境、饮食不当、瘟毒热邪侵入脉道,或外伤等损害白脉,导致三因素中的隆和血液紊乱而诱发白脉病。白脉病是藏医白脉系统遭受致病因素的影响后所致的一系列疾病的总称,临床上很多疾病归属于“白脉病”。中风病是藏医白脉病的一种,临症时需根据疾病的寒热属性、发病时间、病位及其三因素(赤巴、隆、培根)归属情况,据理选药、对治疾病,是藏医辨治白脉病的基本规律,临床时应按照藏医的诊疗规律、综合诊查病因、把握疾病证候变化规律来施治用药。 相似文献
997.
Mengdi Zhang Jianhua Liu Chen Li Jianwei Gao Chuanhui Xu Xiaoyu Wu Tiesheng Xu Chenbin Cui Hongkui Wei Jian Peng Rong Zheng 《Nutrients》2022,14(13)
Obesity may cause metabolic syndrome and has become a global public health problem, and dietary fibers (DF) could alleviate obesity and metabolic syndrome by regulating intestinal microbiota. We developed a functional fiber (FF) with a synthetic mixture of polysaccharides, high viscosity, water-binding capacity, swelling capacity, and fermentability. This study aimed to investigate the effect of FF on obesity and to determine its prevention of obesity by modulating the gut microbiota. Physiological, histological, and biochemical parameters, and gut microbiota composition were investigated in the following six groups: control group (Con), high-fat diet group (HFD), low-fat diet group (LFD, conversion of HFD to LFD), high-fat +8% FF group (8% FF), high-fat +12% FF group (12% FF), and high-fat +12% FF + antibiotic group (12% FF + AB). The results demonstrated that 12% FF could promote a reduction in body weight and epididymal adipocyte area, augment insulin sensitivity, and stimulate heat production from brown adipose tissue (BAT) (p < 0.05). Compared with the HFD, 12% FF could also significantly improve the intestinal morphological integrity, attenuate systemic inflammation, promote intestinal microbiota homeostasis, and stabilize the production of short-chain fatty acids (SCFAs) (p < 0.05). Consistent with the results of 12% FF, the LFD could significantly reduce the body weight and epididymal adipocyte area relative to the HFD (p < 0.05), but the LFD and HFD showed no significant difference (p > 0.05) in the level of inflammation and SCFAs. Meanwhile, 12% FF supplementation showed an increase (p < 0.05) in the abundance of the Bifidobacterium, Lactococcus, and Coprococcus genus in the intestine, which had a negative correlation with obesity and insulin resistance. Additionally, the treatment with antibiotics (12% FF + AB) could inhibit the effect of FF in the HFD. The Kyoto Encyclopedia of Genes and Genomes (KEGG) function prediction revealed that 12% FF could significantly inhibit the cyanogenic amino acid metabolic pathway and decrease the serum succinate concentration relative to the HFD group. The overall results indicate that 12% FF has the potential to reduce obesity through the beneficial regulation of the gut microbiota and metabolites. 相似文献
998.
目的:观察中药内外结合治疗输卵管阻塞性不孕的临床疗效。方法:120例输卵管阻塞性不孕患者分为两组。对照组56例给予常规西药治疗;治疗组64例给予中药内服并保留中药灌肠治疗。结果:治疗组治愈率为60.9%,总有效率为84.4%;对照组治愈率为39.3%,总有效率为50.0%,两组总有效率比较有显著差异(P<0.05)。结论:中药内外结合治疗输卵管阻塞性不孕有较好疗效,值得临床推广。 相似文献
999.
目的 探讨个性化综合护理对胎膜早破患者焦虑、抑郁情绪及新生儿结局的影响。方法 本研究选取河南省某医院2020年3月—2021年4月收治的胎膜早破患者340例作为研究对象,按照随机数字表法分为对照组和观察组,各170例。对照组患者给予常规护理,观察组患者在对照组的基础上予以个性化综合护理。比较2组患者护理前及出院时焦虑自评表(SAS)及抑郁自评表(SDS)评分;观察记录2组患者护理后的分娩方式、产后的并发症发生情况;观察并记录2组新生儿的不良结局。结果 护理前,2组患者SAS及SDS评分比较,差异无统计学意义(P>0.05)。出院时,2组患者SAS及SDS评分均低于护理前,且观察组低于对照组,差异均有统计学意义(P<0.05)。观察组患者自然分娩率为81.18%,高于对照组的59.41%,差异有统计学意义(P<0.05)。2组患者阴道助产率、剖宫产率比较,差异无统计学意义(P>0.05)。对照组患者并发症发生率为10.58%,高于观察组的2.36%,差异有统计学意义(P<0.05)。观察组新生儿不良结局发生率为18.23%,低于对照组的35.89%,差异有统... 相似文献
1000.
Neural mechanisms of the mood effects on third‐party responses to injustice after unfair experiences
Behavioral decision theory argues that humans can adjust their third‐party responses (e.g., punishment and compensation) to injustice by integrating unfair experiences. Typically, the mood plays an important role in such a decision‐making process. However, the underlying neurocognitive bases remain largely unclear. We first employ a modified third‐party justice game in which an allocator split an amount of money between oneself and a receiver. The participants can reapportion the money as observers by choosing from the following three costly options: compensate the receiver, accept the current allocation, or punish the allocator. Then, a second‐party pseudo interaction is conducted where participants receive more (i.e., advantageous unfair experience) or less (i.e., disadvantageous unfair experience) than others. Finally, participants perform the third‐party justice game again after unfair experiences. Here, we use functional near‐infrared spectroscopy (fNIRS) to measure participants'' brain activities during third‐party responses to injustice. We find participants compensate more to the receiver after advantageous unfair experience, which involved enhanced positive emotion, weakened sense of unfairness, and is linked with increased activity in the right dorsolateral prefrontal cortex (rDLPFC). In contrast, participants punish more on the allocator after disadvantageous unfair experience, which might primarily stem from their negative emotional responses, strong sense of unfairness, and is associated with significantly decreased activity in the rDLPFC. Our results suggest that third‐party compensation and punishment involved differential psychological and neural bases. Our findings highlight the crucial roles of second‐party unfair experiences and the corresponding mood responses in third‐party responses to unfairness, and unravel the intermediate neural architecture. 相似文献