全文获取类型
收费全文 | 88240篇 |
免费 | 7295篇 |
国内免费 | 3055篇 |
专业分类
耳鼻咽喉 | 1036篇 |
儿科学 | 1551篇 |
妇产科学 | 2331篇 |
基础医学 | 9466篇 |
口腔科学 | 1566篇 |
临床医学 | 9934篇 |
内科学 | 13867篇 |
皮肤病学 | 1550篇 |
神经病学 | 4438篇 |
特种医学 | 3542篇 |
外国民族医学 | 6篇 |
外科学 | 10641篇 |
综合类 | 11351篇 |
现状与发展 | 12篇 |
一般理论 | 11篇 |
预防医学 | 6535篇 |
眼科学 | 1634篇 |
药学 | 8294篇 |
49篇 | |
中国医学 | 4277篇 |
肿瘤学 | 6499篇 |
出版年
2024年 | 170篇 |
2023年 | 757篇 |
2022年 | 1805篇 |
2021年 | 3086篇 |
2020年 | 2117篇 |
2019年 | 2072篇 |
2018年 | 2519篇 |
2017年 | 2230篇 |
2016年 | 2040篇 |
2015年 | 3298篇 |
2014年 | 4222篇 |
2013年 | 5106篇 |
2012年 | 7224篇 |
2011年 | 7234篇 |
2010年 | 5146篇 |
2009年 | 4584篇 |
2008年 | 5573篇 |
2007年 | 5454篇 |
2006年 | 5061篇 |
2005年 | 4438篇 |
2004年 | 3756篇 |
2003年 | 3472篇 |
2002年 | 2860篇 |
2001年 | 2305篇 |
2000年 | 1969篇 |
1999年 | 1467篇 |
1998年 | 585篇 |
1997年 | 487篇 |
1996年 | 456篇 |
1995年 | 411篇 |
1994年 | 387篇 |
1993年 | 267篇 |
1992年 | 723篇 |
1991年 | 595篇 |
1990年 | 549篇 |
1989年 | 496篇 |
1988年 | 428篇 |
1987年 | 432篇 |
1986年 | 361篇 |
1985年 | 298篇 |
1984年 | 230篇 |
1983年 | 195篇 |
1982年 | 125篇 |
1981年 | 124篇 |
1980年 | 106篇 |
1979年 | 209篇 |
1978年 | 163篇 |
1977年 | 106篇 |
1976年 | 120篇 |
1975年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.
目的本研究利用创伤性脑损伤(traumatic brain injury,TBI)小鼠模型观察阿魏酸(FA)对TBI的神经保护作用,为防治TBI继发性损伤的药物开发提供新思路。方法利用C57/BL6小鼠采用小鼠重复轻度脑损伤模型进行造模。通过干湿重比值法检测脑组织水肿、水迷宫实验检测小鼠学习记忆能力、HE染色法观察小鼠脑组织形态学变化、采用免疫组化法检测小胶质细胞的激活情况。结果与TBI组小鼠比较,阿魏酸组小鼠:脑含水量明显降低(P<0.05),Morris水迷宫实验中逃避潜伏期较TBI模型组明显缩短,原象限停留时间明显延长,活化的小胶质细胞减少。结论阿魏酸可改善TBI小鼠的空间学习记忆能力,降低TBI小鼠脑含水量,改善TBI小鼠的脑组织形态学变化,其机制与阿魏酸抑制小胶质细胞活化有关。 相似文献
33.
34.
目的观察分析水针疗法联合清热祛毒汤治疗寻常型银屑病(血热证)的疗效及其作用机制。方法选择2018年8月—2019年7月在我院接收治疗的112例寻常型银屑病患者作为分析对象,采取随机分组的办法将其分为对照组56例和研究组56例,对照组患者采取水针疗法治疗,研究组在对照组的基础上联合清热祛毒汤治疗。比较分析2组患者的疗效;治疗前后的中医证候评分、皮肤病生活质量指数(DLQI)评分;治疗前后皮损面积、浸润、鳞屑、红斑等评分;治疗前后肿瘤坏死因子α(TNF-α)、白细胞介素6(IL-6)、血管内皮生长因子(VEGF)水平变化情况。结果研究组患者治疗总有效率89.29%明显高于对照组73.21%(P<0.05);治疗前,2组患者的中医证候评分、DLQI评分、皮损面积、浸润、鳞屑、红斑等评分及TNF-α、IL-6、VEGF等水平比较(P>0.05);研究组患者治疗后的中医证候评分与DLQI评分明显低于治疗前(P<0.05);研究组患者治疗后的皮损面积、浸润、鳞屑、红斑等评分明显低于对照组(P<0.05);研究组患者治疗后的TNF-α、IL-6、VEGF等水平明显低于对照组(P<0.05)。结论对寻常型银屑病患者采取水针疗法联合清热祛毒汤治疗的疗效显著,能有效改善中医证候表现,提高生活质量,减轻皮损程度,降低炎症反应,其作用机制可能与炎症因子水平、皮损血管增生相关。 相似文献
35.
Ping Liu Jiang Peng Gong-Hai Han Xiao Ding Shuai Wei Gang Gao Kun Huang Feng Chang Yu Wang 《中国神经再生研究》2019,(8)
Resident and inflammatory macrophages are essential effectors of the innate immune system. These cells provide innate immune defenses and regulate tissue and organ homeostasis. In addition to their roles in diseases such as cancer, obesity and osteoarthritis, they play vital roles in tissue repair and disease rehabilitation. Macrophages and other inflammatory cells are recruited to tissue injury sites where they promote changes in the microenvironment. Among the inflammatory cell types, only macrophages have both pro-inflammatory(M1) and anti-inflammatory(M2) actions, and M2 macrophages have four subtypes. The co-action of M1 and M2 subtypes can create a favorable microenvironment, releasing cytokines for damaged tissue repair. In this review, we discuss the activation of macrophages and their roles in severe peripheral nerve injury. We also describe the therapeutic potential of macrophages in nerve tissue engineering treatment and highlight approaches for enhancing M2 cell-mediated nerve repair and regeneration. 相似文献
36.
目的探讨奥沙利铂如何调控MAPK通路,抑制胃癌细胞的增殖。方法NCBI检索文献,利用TargetScan、StarBase和miRBase数据库,进行GO分析与KEGG通路富集,找到相关miRNAs,预测靶基因。应用Real-time PCR、MTT、Hoechst33258、流式细胞术、细胞划痕实验、Western blot等方法分析人胃癌SGC-7901细胞的增殖、细胞周期、侵袭及蛋白表达情况。结果胃癌细胞中miR-7-5p显著低表达,RAF1与miR-7-5p存在互靶关系。miR-7-5p mimics与奥沙利铂均可促进SGC-7901细胞的凋亡,提高G1期细胞百分率(P<0.05),降低侵袭、迁移速度。caspase3、caspase9蛋白表达升高,Bcl-2/Bax比值降低(P<0.05)。结论过表达miR-7-5p与奥沙利铂均可促进胃癌SGC-7901细胞的凋亡,提示奥沙利铂可能通过上调miRNA-7-5p促进SGC-7901细胞的凋亡,降低侵袭、迁移速度。 相似文献
37.
The state of the mother''s immune system during pregnancy has an important role in fetal development and disruptions in the balance of this system are associated with a range of neurologic, neuropsychiatric and neurodevelopmental disorders. Epidemiological and clinical reports reveal various clues that suggest a possible association between developmental neuropsychiatric disorders and family history of immune system dysfunction. Over the past three decades, analogous increases have been reported in both the incidence of neurodevelopmental disorders and immune-related disorders, particularly allergy and asthma, raising the question of whether allergic asthma and characteristics of various neurodevelopmental disorders share common causal links. We used a mouse model of maternal allergic asthma to test this novel hypothesis that early fetal priming with an allergenic exposure during gestation produces behavioral deficits in offspring. Mothers were primed with an exposure to ovalbumin (OVA) before pregnancy, then exposed to either aerosolized OVA or vehicle during gestation. Both male and female mice born to mothers exposed to aerosolized OVA during gestation exhibited altered developmental trajectories in weight and length, decreased sociability and increased marble-burying behavior. Moreover, offspring of OVA-exposed mothers were observed to have increased serotonin transporter protein levels in the cortex. These data demonstrate that behavioral and neurobiological effects can be elicited following early fetal priming with maternal allergic asthma and provide support that maternal allergic asthma may, in some cases, be a contributing factor to neurodevelopmental disorders. 相似文献
38.
Maggie L. Westfal David C. Chang Cassandra M. Kelleher 《Journal of pediatric surgery》2019,54(1):140-144
Purpose
The purpose of this study was to evaluate trends in demographics and outcomes of pediatric breast cancer in a United States population-based cohort.Methods
The Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify all pediatric patients with malignant breast tumors between 1973 and 2014. Analysis was performed using Stata Statistical Software version 13.1. Associations between categorical variables were made using X2 test. Log-rank test was used for univariate survival analysis. Kaplan–Meier analysis investigated five-year survival rates across several variables. Adjusted analysis was performed using a Cox Proportional-Hazards regression.Results
134 patients with breast malignancies were identified. Carcinoma was the most prevalent histology (48.5%), followed by fibroepithelial tumors (FETs) (35.1%), and sarcoma (14.2%). FETs were twice as common in black compared to nonblack patients (56.3% vs. 29.0%, p?<?0.01). Analyzing histology by stage revealed that 100% of FETs were early stage disease (p?<?0.0001). 46.7% of the tumors tested were ER/PR negative, more than twice as many compared to the published adult estimate of 20.0%. Unadjusted survival analysis revealed worse survival for patients with adenocarcinoma/sarcomas, advanced stage, and high grade disease, without a survival difference between races.Conclusion
Breast cancer remains a rare malignancy among pediatric patients. Although black patients were found to have more noncarcinomatous tumors with less advanced disease, this did not confer a survival advantage.Type of study
Retrospective cohort study.Level of evidence
Level III. 相似文献39.
Ming-Yeh Yang Ching-Yuan Huang Tina H.T. Chiu Kai-Chih Chang Ming-Nan Lin Liang-Yü Chen Anren Hu 《Yao wu shi pin fen xi = Journal of food and drug analysis.》2019,27(2):494-501
Vitamin D is responsible for multiple metabolic functions in humans. Rickets are the most common disease caused by vitamin D deficiency. It is caused by poor calcium intake resulting in poor serum-ionized calcium. The purpose of this study is to develop a rapid, sensitive, and feasible method to determine the 25-hydroxy-vitamin D3 (25(OH)D3) levels in blood samples for clinical assessment. In this study, gas chromatography coupled mass spectrometry with trimethylsilyl derivatization (TMS-GC-MS) is the most suitable protocol for quantitative analyses of 25(OH)D3. Performance of method was evaluated and compared with liquid chromatography and immunoassay. Method validation has been carried out with plasma specimens. The limit of quantitation of TMS-GC-MS method is 1.5 ppb with good linear correlation. Furthermore, the dietary intake and nutritional status of vegetarian and non-vegetarians in Taiwan were assessed by our validated method. As a result, this vitamin D nutrition survey demonstrates that most Taiwanese people have insufficient vitamin D. Due to dietary habits; the male vegans may have the highest risk of vitamin D deficiency. 相似文献
40.
AbstractCadmium (Cd) as environmental pollutant can induce severe damage, particularly to the testis. This study investigated the effects of Caffeic acid phenethyl ester (CAPE) on testicular dysfunction induced by Cd. Adult mice were intraperitoneally injected with cadmium chloride (CdCl2) with different doses of CAPE pretreatment. After CdCl2 injection, body/testis weight ratio decreased, Cd levels accumulated and zinc levels decreased in testis. Furthermore, Cd intoxication caused a significant increase of oxidative stress levels, antioxidant enzymes activities, and glutathione levels. Interestingly, significant improvements were observed after the administration of CAPE. Our results demonstrated the protective effect of CAPE, linking Cd testicular dysfunction to oxidative stress. 相似文献