首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   131226篇
  免费   11785篇
  国内免费   8020篇
耳鼻咽喉   995篇
儿科学   1944篇
妇产科学   2161篇
基础医学   15518篇
口腔科学   2380篇
临床医学   16392篇
内科学   22771篇
皮肤病学   1407篇
神经病学   9250篇
特种医学   4784篇
外国民族医学   58篇
外科学   14081篇
综合类   17199篇
现状与发展   23篇
一般理论   14篇
预防医学   7728篇
眼科学   3455篇
药学   12871篇
  107篇
中国医学   6705篇
肿瘤学   11188篇
  2024年   223篇
  2023年   1693篇
  2022年   3022篇
  2021年   6619篇
  2020年   4846篇
  2019年   4238篇
  2018年   4582篇
  2017年   3853篇
  2016年   3839篇
  2015年   5585篇
  2014年   6969篇
  2013年   6567篇
  2012年   9333篇
  2011年   10379篇
  2010年   6241篇
  2009年   5123篇
  2008年   6951篇
  2007年   6867篇
  2006年   6849篇
  2005年   6749篇
  2004年   4666篇
  2003年   4337篇
  2002年   3725篇
  2001年   3335篇
  2000年   3387篇
  1999年   3387篇
  1998年   1874篇
  1997年   1685篇
  1996年   1449篇
  1995年   1284篇
  1994年   1091篇
  1993年   740篇
  1992年   1271篇
  1991年   1075篇
  1990年   1002篇
  1989年   968篇
  1988年   803篇
  1987年   700篇
  1986年   624篇
  1985年   493篇
  1984年   340篇
  1983年   260篇
  1982年   156篇
  1981年   130篇
  1980年   113篇
  1979年   232篇
  1978年   128篇
  1974年   121篇
  1973年   125篇
  1972年   122篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
81.
82.
Background: The key factors of inducing drug cravings in persons abstaining from drug use remain a focus of addictions research. Given the accumulating evidences, the scope of cues investigated in the cue-reactivity paradigm has increased considerably. Yet, few studies have examined the effects of the intensity and endurance of different types of cues on their ability to induce craving. This study investigated differences among drug-cue words, negative physiological-cue words, and negative social-cue words in the induction of drug cravings among persons abstaining from heroin.

Methods: The sample consisted of 149 male abstinent heroin abusers from four addiction rehabilitation centers in China. Based on their abstinence lengths, they were labeled as short-term, medium-term, and long-term abstainer participants respectively. All participants completed a stress-imagery task and rated craving by visual analog scale.

Results: There was a significant interaction of cue type and abstinence length. There was no difference on the craving induced by three types of cue words in the short-term group. In the medium-term group, craving induced by negative social-cue words was significantly stronger than that by negative physiological-cue words, but not that by drug-cue words. In the long-term group, the craving induced by negative social-cue words remained the strongest, significantly stronger than that by both drug-cue words and negative physiological-cue words.

Conclusion: Negative social-cue words presented in the current study retain the ability to induce craving in heroin abstainers; this finding suggests that negative social cues encountered under more general circumstances could be a risk factor for relapse.  相似文献   

83.
84.
The inferior alveolar nerve and facial nerve are the two most important nerves in the dental and maxillofacial region. The injury to them is one of the major postoperative complications after alveolar surgery and orthognathic surgery. However, recovering the nerve function after injury takes a long time and the recovery effect tends to be unsatisfactory. In recent years, an intensively investigated technique, low level laser which has been applying in assisting the recovery of nerve function, has been gradually proved to be effective in clinically treating postoperative nerve injury. In this article we review in terms of the mechanisms involved in low level laser-assisted functional restoration of nerve injury and its clinical application in the recovery of nerve function in the dental and maxillofacial area as well.  相似文献   
85.
Abstract

This study is a single-center, retrospective analysis of postmenopausal women presenting with dyspareunia and vulvar pain, aiming to evaluate relative effectiveness of vestibular CO2 laser therapy as a treatment. Three monthly sessions of laser were performed to each patient and thereafter a three-months follow-up was stablished. A total number of 72 patients undergoing vestibular laser treatment were recruited from patient files in the period between 2016 and 2018. Among these, 39 women also received a concomitant treatment with ospemifene (60?mg/day) during the study period. There was a statistically significant reduction of all the symptoms in both groups up to the three month follow-up. Regarding dryness and dyspareunia, the relief tent to be more prominent in the ospemifene?+?laser group at all follow-ups and remained statistically significant at three-month follow-up. Specifically, vestibular dryness was significantly lower in the ospemifene?+?laser group compared with the laser treatment group (?87% vs???34%, respectively), and the vestibular health score started declining faster in the ospemifene?+?laser group. Although, additional research is needed to understand the mechanism of action, our data shows that a combination regimen of laser and ospemifene may improve clinical effectiveness for long-term treatment of symptoms associated with the under-recognized genitourinary syndrome of menopause.  相似文献   
86.
Resistance to chemotherapy is a major challenge for the treatment of patients with colorectal cancer (CRC). Previous studies have found that microRNAs (miRNAs) play key roles in drug resistance; however, the role of miRNA‐373‐3p (miR‐375‐3p) in CRC remains unclear. The current study aimed to explore the potential function of miR‐375‐3p in 5‐fluorouracil (5‐FU) resistance. MicroRNA‐375‐3p was found to be widely downregulated in human CRC cell lines and tissues and to promote the sensitivity of CRC cells to 5‐FU by inducing colon cancer cell apoptosis and cycle arrest and by inhibiting cell growth, migration, and invasion in vitro. Thymidylate synthase (TYMS) was found to be a direct target of miR‐375‐3p, and TYMS knockdown exerted similar effects as miR‐375‐3p overexpression on the CRC cellular response to 5‐FU. Lipid‐coated calcium carbonate nanoparticles (NPs) were designed to cotransport 5‐FU and miR‐375‐3p into cells efficiently and rapidly and to release the drugs in a weakly acidic tumor microenvironment. The therapeutic effect of combined miR‐375 + 5‐FU/NPs was significantly higher than that of the individual treatments in mouse s.c. xenografts derived from HCT116 cells. Our results suggest that restoring miR‐375‐3p levels could be a future novel therapeutic strategy to enhance chemosensitivity to 5‐FU.  相似文献   
87.
目的 初步探讨应用艾尔巴韦/格拉瑞韦治疗慢性丙型肝炎(CHC)患者的疗效。方法 2017年3月~2018年3月仙桃市第一人民医院感染病科收治的CHC患者82例,被随机分为对照组41例和观察组41例,分别给予聚乙二醇干扰素-α联合利巴韦林治疗和艾尔巴韦/格拉瑞韦治疗,两组均连续治疗24周。采用RT- PCR法检测血清 HCV RNA,采用全基因序列测定法行病毒基因分型。比较两组早期病毒学应答(EVR)、治疗结束时病毒学应答(ETVR)和持续病毒学应答(SVR)。结果 在治疗结束时,观察组血清丙氨酸氨基转移酶(ALT)水平为(47.9±19.7)U/L,显著低于对照组【(63.5±21.2)U/L,P<0.05】,天冬氨酸氨基转移酶(AST)水平为(55.5±22.3)U/L,显著低于对照组【(81.3±25.8)U/L,P<0.05】;观察组EVR、ETVR和SVR分别为48.8%、63.4%和70.7%,与对照组的41.5%、53.7%和65.8%比,无统计学差异(P>0.05);18例观察组非HCV Ⅰ型感染者EVR、ETVR和SVR分别为88.9%、94.4%和88.9%,显著高于同组23例HCV Ⅰ型感染者(分别为52.2%、60.9%和52.2%, P<0.05),而与对照组15例非HCV Ⅰ型感染者比,无统计学差异(分别为86.7%、93.3%和73.3%, P>0.05);观察组SVR12为87.8%(36/41),显著高于对照组的73.2%(30/41,P<0.05)。结论 应用直接抗病毒(DAA)药物艾尔巴韦/格拉瑞韦治疗CHC患者近期疗效达到,但远期疗效似优于标准治疗方案, 值得临床进一步验证。  相似文献   
88.
目的:探索原肌球蛋白4(Tropomyosin4,TPM4)在胃癌细胞的迁移、侵袭和转移中的作用。方法:利用Real-time PCR、Western Blot及免疫荧光,检测原肌球蛋白4在不同胃癌细胞系及正常胃上皮细胞中的表达情况;利用免疫组化,检测原肌球蛋白4在胃癌组织及癌旁正常组织中的表达情况;利用慢病毒技术,在GC9811-P细胞中,分别转染LV-TPM4、shRNA-TPM4及对照空载体;通过Transwell和体内实验,检测胃癌细胞迁移、侵袭和转移。结果:Real-time PCR、Western Blot及免疫组化结果显示,原肌球蛋白4在胃癌细胞系及胃癌组织中的表达降低;上调原肌球蛋白4的表达后,抑制胃癌细胞的迁移、侵袭和转移;下调原肌球蛋白4的表达后,促进胃癌细胞的迁移、侵袭和转移(P<0.05)。结论:原肌球蛋白4抑制胃癌细胞的迁移、侵袭和转移。  相似文献   
89.
90.
Ferroptosis is an iron-dependent novel cell death pathway. Deferoxamine, a ferroptosis inhibitor, has been reported to promote spinal cord injury repair. It has yet to be clarified whether ferroptosis inhibition represents the mechanism of action of Deferoxamine on spinal cord injury recovery. A rat model of Deferoxamine at thoracic 10 segment was established using a modified Allen's method. Ninety 8-week-old female Wistar rats were used. Rats in the Deferoxamine group were intraperitoneally injected with 100 mg/kg Deferoxamine 30 minutes before injury. Simultaneously, the Sham and Deferoxamine groups served as controls. Drug administration was conducted for 7 consecutive days. The results were as follows:(1) Electron microscopy revealed shrunken mitochondria in the spinal cord injury group.(2) The Basso, Beattie and Bresnahan locomotor rating score showed that recovery of the hindlimb was remarkably better in the Deferoxamine group than in the spinal cord injury group.(3) The iron concentration was lower in the Deferoxamine group than in the spinal cord injury group after injury.(4) Western blot assay revealed that, compared with the spinal cord injury group, GPX4, xCT, and glutathione expression was markedly increased in the Deferoxamine group.(5) Real-time polymerase chain reaction revealed that, compared with the Deferoxamine group, mRNA levels of ferroptosis-related genes Acyl-CoA synthetase family member 2(ACSF2) and iron-responsive element-binding protein 2(IREB2) were up-regulated in the Deferoxamine group.(6) Deferoxamine increased survival of neurons and inhibited gliosis. These findings confirm that Deferoxamine can repair spinal cord injury by inhibiting ferroptosis. Targeting ferroptosis is therefore a promising therapeutic approach for spinal cord injury.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号