全文获取类型
收费全文 | 64106篇 |
免费 | 5471篇 |
国内免费 | 3382篇 |
专业分类
耳鼻咽喉 | 709篇 |
儿科学 | 953篇 |
妇产科学 | 726篇 |
基础医学 | 6507篇 |
口腔科学 | 1266篇 |
临床医学 | 6811篇 |
内科学 | 8752篇 |
皮肤病学 | 1134篇 |
神经病学 | 3696篇 |
特种医学 | 2753篇 |
外国民族医学 | 29篇 |
外科学 | 8072篇 |
综合类 | 11336篇 |
现状与发展 | 11篇 |
一般理论 | 29篇 |
预防医学 | 4481篇 |
眼科学 | 1547篇 |
药学 | 6109篇 |
52篇 | |
中国医学 | 3416篇 |
肿瘤学 | 4570篇 |
出版年
2024年 | 153篇 |
2023年 | 763篇 |
2022年 | 1823篇 |
2021年 | 2499篇 |
2020年 | 2027篇 |
2019年 | 1701篇 |
2018年 | 1878篇 |
2017年 | 1845篇 |
2016年 | 1758篇 |
2015年 | 2625篇 |
2014年 | 3314篇 |
2013年 | 3492篇 |
2012年 | 5179篇 |
2011年 | 5506篇 |
2010年 | 3858篇 |
2009年 | 3389篇 |
2008年 | 4045篇 |
2007年 | 3987篇 |
2006年 | 3714篇 |
2005年 | 3445篇 |
2004年 | 2484篇 |
2003年 | 2161篇 |
2002年 | 1834篇 |
2001年 | 1406篇 |
2000年 | 1305篇 |
1999年 | 1120篇 |
1998年 | 597篇 |
1997年 | 525篇 |
1996年 | 404篇 |
1995年 | 386篇 |
1994年 | 322篇 |
1993年 | 226篇 |
1992年 | 349篇 |
1991年 | 344篇 |
1990年 | 322篇 |
1989年 | 283篇 |
1988年 | 238篇 |
1987年 | 222篇 |
1986年 | 223篇 |
1985年 | 172篇 |
1984年 | 117篇 |
1983年 | 75篇 |
1982年 | 54篇 |
1981年 | 59篇 |
1979年 | 76篇 |
1978年 | 52篇 |
1977年 | 53篇 |
1974年 | 68篇 |
1973年 | 64篇 |
1972年 | 67篇 |
排序方式: 共有10000条查询结果,搜索用时 7 毫秒
21.
目的:比较双眼外直肌后徙术与常规疗法治疗斜视的临床疗效。方法:选取2016年6月-2017年6月笔者医院收治的128例斜视患者,按治疗方式不同分成对照组和研究组,每组各64例。其中对照组患者行常规单眼外直肌后徙联合内直肌缩短术(R&R),研究组患者行双眼外直肌后徙术(BLR-rec)。术后对患者随访1年,观察术后眼位正位率、欠矫率、过矫率,视觉功能恢复情况以及并发症发生率。结果:研究组患者正位率为89.06%高于对照组的68.75%,差异有统计学意义(P<0.05)。术前,对照组和研究组患者视近度、视远度和平均斜视度比较,两组患者融合功能和立体视功能占比比较,差异均无统计学意义(P>0.05)。术后,两组患者的斜视度较治疗前均出现了明显下降(P<0.05),且研究组治疗后斜视度下降幅度明显大于对照组(P<0.05);两组患者视觉功能恢复率均明显增加(P<0.05),且研究组恢复率明显大于对照组(P<0.05)。研究组并发症发生率明显低于对照组(P<0.05)。结论:双眼外直肌后徙术较单眼外直肌后徙联合内直肌缩短术有更好地临床效果,且安全性更高,值得临床推广。 相似文献
22.
Dry powder inhalers (DPIs) are gaining popularity for the delivery of drugs. A cost effective and efficient delivery device is necessary. Developing new DPIs by modifying an existing device may be the simplest way to improve the performance of the devices. The aim of this research was to produce a new DPIs using computational fluid dynamics (CFD). The new DPIs took advantages of the Cyclohaler® and the Rotahaler®. We chose a combination of the capsule chamber of the Cyclohaler® and the mouthpiece and grid of the Rotahaler®. Computer-aided design models of the devices were created and evaluated using CFD. Prototype models were created and tested with the DPI dispersion experiments. The proposed model 3 device had a high turbulence with a good degree of deagglomeration in the CFD and the experiment data. The %fine particle fraction (FPF) was around 50% at 60?L/min. The mass median aerodynamic diameter was around 2.8–4?μm. The FPF were strongly correlated to the CFD-predicted turbulence and the mechanical impaction parameters. The drug retention in the capsule was only 5–7%. In summary, a simple modification of the Cyclohaler® and Rotahaler® could produce a better performing inhaler using the CFD-assisted design. 相似文献
23.
You-Wen Tan 《World Journal of Meta-Analysis》2021,9(6):488-495
Nilotinib is a specific breakpoint cluster region-Abelson leukemia virus-tyrosine kinase inhibitor that is used as an effective first- or second-line treatment in imatinib-resistant chronic myelogenous leukemia (CML) patients. Hepatotoxicity due to nilotinib is a commonly reported side effect; however, abnormal liver function test (LFT) results have been reported in asymptomatic cases. When alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels are more than five-fold the upper limit of the normal (ULN) or when the serum total bilirubin level is more than three-fold the ULN, dose modification or discontinuation of nilotinib is recommended, resulting in decreased levels of hematological indicators in certain patients with CML. Nilotinib-induced hyperbilirubinemia typically manifests as indirect bilirubinemia without elevated ALT or AST levels. Such abnormal liver functioning is thus not attributed to the presence of a true histologic lesion of the liver. The underlying mechanism may be related to the inhibition of uridine diphosphate glucuronosyltransferase activity. Therefore, nilotinib dose adjustment is not recommended for this type of hyperbilirubinemia, and in the absence of elevated liver enzyme levels or presence of abnormal LFT findings, physicians should consider maintaining nilotinib dose intensity without modifications. 相似文献
24.
Growth Hormone Induces Recurrence of Infantile Hemangiomas After Apparent Involution: Evidence of Growth Hormone Receptors in Infantile Hemangioma
下载免费PDF全文
![点击此处可从《Pediatric dermatology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Naikhoba C. O. Munabi B.A. Qian Kun Tan H.S. Maria C. Garzon M.D. Gerald G. Behr M.D. Carrie J. Shawber Ph.D. June K. Wu M.D. 《Pediatric dermatology》2015,32(4):539-543
Infantile hemangiomas (IHs) are the most common benign tumor of infancy, characterized by a natural history of early proliferation in the first months of life to eventual involution during childhood, often with residual fibrofatty tissue. Once involution has been achieved, IHs do not typically recur. We present two cases of exogenous growth hormone therapy resulting in the recurrence of IHs in late childhood, supported by radiological, immunohistochemical, in vitro, and in vivo evidence. 相似文献
25.
26.
27.
Hanna Lee Mary K. Tan Andrew T. Yan Paul Angaran Paul Dorian Claudia Bucci Jean C. Gregoire Alan D. Bell Martin S. Green Peter L. Gross Allan Skanes Charles R. Kerr L. Brent Mitchell Jafna L. Cox Vidal Essebag Brett Heilbron Krishnan Ramanathan Carl Fournier Shaun G. Goodman 《The Canadian journal of cardiology》2019,35(2):160-168
Background
Physicians treating nonvalvular atrial fibrillation (AF) assess stroke and bleeding risks when deciding on anticoagulation. The agreement between empirical and physician-estimated risks is unclear. Furthermore, the association between patient and physician sex and anticoagulation decision-making is uncertain.Methods
We pooled data from 2 national primary care physician chart audit databases of patients with AF (Facilitating Review and Education to Optimize Stroke Prevention in Atrial Fibrillation and Coordinated National Network to Engage Physicians in the Care and Treatment of Patients with Atrial Fibrillation Chart Audit) with a combined 1035 physicians (133 female, 902 male) and 10,927 patients (4567 female and 6360 male).Results
Male physicians underestimated stroke risk in female patients and overestimated risk in male patients. Female physicians estimated stroke risk well in female patients but underestimated the risk in male patients. Risk of bleeding was underestimated in all. Despite differences in risk assessment by physician and patient sex, > 90% of patients received anticoagulation across all subgroups. There was modest agreement between physician estimated and calculated (ie, CHADS2 score) stroke risk: Kappa scores were 0.41 (0.35-0.47) for female physicians and 0.34 (0.32-0.36) for male physicians.Conclusions
Our study is the first to examine the association between patient and physician sex influences and stroke and bleeding risk estimation in AF. Although there were differences in agreement between physician estimated stroke risk and calculated CHADS2 scores, these differences were small and unlikely to affect clinical practice; further, despite any perceived differences in the accuracy of risk assessment by sex, most patients received anticoagulation. 相似文献28.
Quantitative chemical exchange saturation transfer (qCEST) MRI – omega plot analysis of RF‐spillover‐corrected inverse CEST ratio asymmetry for simultaneous determination of labile proton ratio and exchange rate
下载免费PDF全文
![点击此处可从《NMR in biomedicine》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Renhua Wu Gang Xiao Iris Yuwen Zhou Chongzhao Ran Phillip Zhe Sun 《NMR in biomedicine》2015,28(3):376-383
Chemical exchange saturation transfer (CEST) MRI is sensitive to labile proton concentration and exchange rate, thus allowing measurement of dilute CEST agent and microenvironmental properties. However, CEST measurement depends not only on the CEST agent properties but also on the experimental conditions. Quantitative CEST (qCEST) analysis has been proposed to address the limitation of the commonly used simplistic CEST‐weighted calculation. Recent research has shown that the concomitant direct RF saturation (spillover) effect can be corrected using an inverse CEST ratio calculation. We postulated that a simplified qCEST analysis is feasible with omega plot analysis of the inverse CEST asymmetry calculation. Specifically, simulations showed that the numerically derived labile proton ratio and exchange rate were in good agreement with input values. In addition, the qCEST analysis was confirmed experimentally in a phantom with concurrent variation in CEST agent concentration and pH. Also, we demonstrated that the derived labile proton ratio increased linearly with creatine concentration (P < 0.01) while the pH‐dependent exchange rate followed a dominantly base‐catalyzed exchange relationship (P < 0.01). In summary, our study verified that a simplified qCEST analysis can simultaneously determine labile proton ratio and exchange rate in a relatively complex in vitro CEST system. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
29.
30.
Han Wang Hui Ding Bo-wen Ouyang Zhenduo Yang Tan Zhong Hongming Fan Xingwu Zhong 《Eye (London, England)》2020,34(12):2328
ObjectivesTo investigate the effect of corneal stromal pocket irrigation after small-incision lenticule extraction (SMILE) on visual acuity, intraocular pressure (IOP), corneal parameters and complications after surgery.MethodsA total of 242 eyes of 121 patients undergoing SMILE were enrolled in this prospective controlled study, and it was designed for one eye to randomly undergo SMILE with balanced salt solution irrigation of the corneal stromal pocket, while the other eye was not. The uncorrected distance visual acuity (UDVA) and slit lamp examination were recorded at 1 hour, 1 day, 1 week, and 1 month. Postoperative corneal density, corneal biomechanical, corneal endothelial cell number, and anterior OCT images were compared at 1 day, 1 week, and 1 month.ResultsCompared with the nonirrigation group, the irrigation group showed significantly higher UDVA at 1 day postoperatively (P < 0.05), but there was no significant difference during the rest of the postoperative period (1 hour, 1 week, and 1 month). In addition, no significant differences were found in IOP, corneal density, corneal biomechanics, corneal endothelial cells, and corneal morphology. No visual decline or severe postoperative complications were found in the patients in this study.ConclusionsInterlamellar irrigation did not affect IOP, corneal parameters, morphology, complications, or UDVA at 1 hour, 1 week, and 1 month after the operation, but it may promote UDVA 1 day after the operation.Subject terms: Refractive errors, Outcomes research, Surgery 相似文献