全文获取类型
收费全文 | 10530篇 |
免费 | 839篇 |
国内免费 | 312篇 |
专业分类
耳鼻咽喉 | 53篇 |
儿科学 | 40篇 |
妇产科学 | 217篇 |
基础医学 | 786篇 |
口腔科学 | 61篇 |
临床医学 | 824篇 |
内科学 | 569篇 |
皮肤病学 | 37篇 |
神经病学 | 300篇 |
特种医学 | 232篇 |
外国民族医学 | 6篇 |
外科学 | 3556篇 |
综合类 | 1824篇 |
现状与发展 | 2篇 |
预防医学 | 379篇 |
眼科学 | 46篇 |
药学 | 1184篇 |
21篇 | |
中国医学 | 593篇 |
肿瘤学 | 951篇 |
出版年
2024年 | 4篇 |
2023年 | 135篇 |
2022年 | 178篇 |
2021年 | 310篇 |
2020年 | 331篇 |
2019年 | 282篇 |
2018年 | 303篇 |
2017年 | 317篇 |
2016年 | 326篇 |
2015年 | 360篇 |
2014年 | 630篇 |
2013年 | 724篇 |
2012年 | 612篇 |
2011年 | 690篇 |
2010年 | 622篇 |
2009年 | 564篇 |
2008年 | 586篇 |
2007年 | 518篇 |
2006年 | 524篇 |
2005年 | 496篇 |
2004年 | 461篇 |
2003年 | 413篇 |
2002年 | 319篇 |
2001年 | 276篇 |
2000年 | 255篇 |
1999年 | 211篇 |
1998年 | 204篇 |
1997年 | 160篇 |
1996年 | 156篇 |
1995年 | 140篇 |
1994年 | 116篇 |
1993年 | 99篇 |
1992年 | 76篇 |
1991年 | 70篇 |
1990年 | 44篇 |
1989年 | 40篇 |
1988年 | 23篇 |
1987年 | 29篇 |
1986年 | 13篇 |
1985年 | 15篇 |
1984年 | 6篇 |
1983年 | 7篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1978年 | 7篇 |
1977年 | 3篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 250 毫秒
31.
David C. Johnson Steven S. Raman Sohrab A. Mirak Lorna Kwan Amirhossein M. Bajgiran William Hsu Cleo K. Maehara Preeti Ahuja Izak Faiena Aydin Pooli Amirali Salmasi Anthony Sisk Ely R. Felker David S.K. Lu Robert E. Reiter 《European urology》2019,75(5):712-720
Background
Multiparametric magnetic resonance imaging (mpMRI) undoubtedly affects the diagnosis and treatment of localized prostate cancer (CaP). However, clinicians need a better understanding of its accuracy and limitations in detecting individual CaP foci to optimize management.Objective
To determine the per-lesion detection rate for CaP foci by mpMRI and identify predictors of tumor detection.Design, setting, and participants
We carried out a retrospective analysis of a prospectively managed database correlating lesion-specific results from mpMRI co-registered with whole-mount pathology (WMP) prostatectomy specimens from June 2010 to February 2018. Participants include 588 consecutive patients with biopsy-proven CaP undergoing 3-T mpMRI before radical prostatectomy at a single tertiary institution.Outcome measurements and statistical analysis
We measured mpMRI sensitivity in detecting individual CaP and clinically significant (any Gleason score ≥7) CaP foci and predictors of tumor detection using multivariate analysis.Results and limitations
The final analysis included 1213 pathologically confirmed tumor foci in 588 patients with primarily intermediate- (75%) or high-risk (12%) CaP. mpMRI detected 45% of all lesions (95% confidence interval [CI] 42–47%), including 65% of clinically significant lesions (95% CI 61–69%) and nearly 80% of high-grade tumors. Some 74% and 31% of missed solitary and multifocal tumors, respectively, were clinically significant. The majority of missed lesions were small (61.1% ≤1 cm); 28.3% were between 1 and 2 cm, and 10.4% were >2 cm. mpMRI missed at least one clinically significant focus in 34% of patients overall, and in 45% of men with multifocal lesions. On multivariate analysis, smaller, low-grade, multifocal, nonindex tumors with lower prostate-specific antigen density were more likely to be missed. Limitations include selection bias in a prostatectomy cohort, lack of specificity data, an imperfect co-registration process, and uncertain clinical significance for undetected lesions.Conclusions
mpMRI detects less than half of all and less than two-thirds of clinically significant CaP foci. The moderate per-lesion sensitivity and significant proportion of men with undetected tumor foci demonstrate the current limitations of mpMRI.Patient summary
Magnetic resonance imaging of the prostate before surgical removal for prostate cancer finds less than half of all individual prostate cancer tumors. Large, solitary, aggressive tumors are more likely to be visualized on imaging. 相似文献32.
33.
正2002年,日本学者Kanaya等[1]首次提出了胃十二指肠全腹腔镜下三角吻合技术,该技术仅利用直线切割闭合器即可完成胃与十二指肠端端吻合。在此基础上Huang等[2]进一步改良了三角吻合术。目前,胃十二指肠三角吻合技术逐渐获得国内外多家医疗中心的认可和开展。本文将介绍在远端胃癌根治术中应用三角吻合技术的相关要点。 相似文献
34.
35.
目的制备美洲大蠊Periplaneta americana口腔原位温敏凝胶。方法采用自由基聚合法首次以N-异丙基丙烯酰胺(NNIPAM)和甲基丙烯酸羟丙酯(HPMA)合成聚(N-异丙基丙烯酰胺-甲基丙烯酸羟丙酯)[P(NNIPAM-HPMA)]作为温敏材料;通过冷溶法制备美洲大蠊口腔原位温敏凝胶,采用Box-Behnken设计响应面法,以溶蚀时间、胶凝时间为评价指标,在固定美洲大蠊提取物用量基础上,对羟丙基甲基纤维素(HPMC)、聚乙烯吡咯烷酮(PVP K30)、P(NNIPAM-HPMA)的用量进行优选。结果通过原位聚合法合成了P(NNIPAM-HPMA)温敏材料;并用响应面法优选了可用于口腔的美洲大蠊原位温敏凝胶的处方,优选的处方为美洲大蠊提取物10%、HPMC 3.0%、PVP K30 9.5%、P(NNIPAM-HPMA) 10.0%,其溶蚀时间为2 h,胶凝时间8~9 s。结论优选得到美洲大蠊口腔原位温敏凝胶,为美洲大蠊提取物的口腔原位局部的临床应用奠定了科学依据。 相似文献
36.
《Obesity research & clinical practice》2020,14(1):34-38
Excess body weight has been causally linked to an increased risk of different cancer types, including gastric cancer but the mechanisms underlying this relationship are not well understood. Superoxide generation rate, activity of complex I in electron transport chain of mitochondria, activity of matrix metalloproteinase (MMP-2 and 9) of adipose tissues (AT) of patients with gastric cancer in AT located adjacent to tumor (ATAT) and at a distance of 3 cm (ATD) are measured to follow the connection of the redox state with some of the microenvironment indicators (HIF-1α, CD68, Plin5), body mass index (BMI) and cancer metastasis.Superoxide generation rate in ATAT positively correlates with BMI (r = 0.59, p < 0.05) being 4 times higher than in control (p < 0.05). MMP-2, 9 activities in ATAT positively correlate with BMI (r = 0.67, p < 0.05) being 3.3-4.0 higher than in control (p < 0.05). In ATD a statistically significant increase of MMP-2 activity is found. In ATAT for the group of patients with distant metastasis (M1) the superoxide generation rate, MMP-2, 9 activities are about 2 times higher (p < 0.05) than in the subgroup without distant metastases (M0). M1 is also characterized by the increased values of HIF-1α+ (factor 1.25), CD68+ (factor 1.4) and Plin5+ (factor 2.1) compared to M0 category in tumor tissues (p < 0.05). The results can be used for better understanding the mechanism(s) of symbiosis of tumor and adipose tissues as well as serve as a basis for new therapeutic approaches. 相似文献
37.
《Actas urologicas espa?olas》2020,44(6):417-422
ObjectiveHistorical review of the procedures and maneuvers described in the literature for the control of Santorini's venous plexus.Material and methodReview of original articles on the design of procedures and maneuvers for the control of the Santorini's venous plexus.ResultsThe control of Santorini's plexus is crucial to reduce blood loss and dissect the prostatic apex. The procedure was first performed by Chute in 1954 and has undergone subsequent modifications by several authors (Reiner and Walsh, Hayashi, Myers, etc.) who have published different maneuvers for its control.ConclusionThere is no ideal procedure or maneuver for the control of the Santorini's plexus. 相似文献
38.
39.
《Actas urologicas espa?olas》2022,46(7):397-406
PurposeAssess multiparametric-MRI (mp-MRI) diagnostic accuracy in the detection of local recurrence of prostate cancer (PCa) after radical prostatectomy (PR) and before radiation therapy (RT).Materials and methodsA total of 188 patients underwent 1.5-T mp-MRI after RP before RT. Patients were divided into 2 groups: with biochemical recurrence (group A) and without but with high risk of local recurrence (group B). Continuous variables were compared between 2 groups using Student-t test; categoric variables were analyzed using Pearson chi-square. ROC analysis was performed considering PSA before RT, ISUP, pT and pN as grouping variables.ResultsPCa recurrence (reduction of PSA levels after RT) was 89.8% in group A and 80.3% in group B. Comparing patients with and without PCa recurrence, there was a significant difference in PSA values before RT for group A and for PSA values before RT and after RT for group B. In group A, there was a significant correlation between PSA before RT and diameter of recurrence and between PSA before RT and time spent before recurrence. The mp-MRI diagnostic accuracy in detecting PCa local recurrence after RP is of 62.2% in group A and 38% in group B. Diffusion weighted imaging is the most specific MRI-sequence and dynamic contrast enhanced the most sensitive. For PSA = 0.5 ng/ml, the AUC decreases while sensitivity and accuracy increase for each MRI-sequence. For PSA = 0.9 ng/ml, dynamic contrast enhanced-AUC increases significantly.Conclusionmp-MRI should always be performed before RT when a recurrence is suspected. New scenarios can be opened considering the role of diffusion weighted imaging for PSA ≤ 0.5 ng/ml. 相似文献
40.
目的:研究大鼠血清氧化调节因子的增龄性改变及平补阴阳中药淫羊藿女贞子的影响作用。方法:8个月龄雄性SD大鼠,随机分为7组,饲养至相应月龄,包括9个月龄组、12个月龄组、15个月龄组、17个月龄组,淫羊藿组、女贞子组、淫羊藿女贞子组(配伍组),以3、6个月龄雄性大鼠为青年对照组。各用药组饲养至15个月龄后开始灌胃给予相应药物2个月。取血清检测以下指标:总抗氧化能力(TT-AOC)、超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-PX)、还原型谷胱甘肽(GSH)、一氧化氮(NO)、总一氧化氮合成酶(tNOS)、诱导型一氧化氮合成酶(iNOS)、结构型一氧化氮合酶(cNOS)及8-羟基脱氧鸟苷(8-OHDG)。结果:与青年大鼠比较,17个月龄大鼠血清SOD、GSH、GSH-PX及T-AOC水平显著降低(均P<0.01),NO、tNOS、iNOS、MDA及8-OHDG含量显著升高(P<0.05或0.01),cNOS差异无统计学意义。与17个月龄大鼠比较,配伍组SOD、GSH、GSH-PX及T-AOC水平显著升高(均P<0.01),NO、tNOS、iNOS、cNOS、MDA及8-OHDG含量均显著降低(P<0.05或0.01)。基于多层感知(Multi-Layer Perceptron,MLP)神经网络模型,结果显示淫羊藿女贞子合用可使17个月龄自然衰老大鼠的上述指标的改变逆转至(10.45±0.87)个月,作用优于淫羊藿、女贞子单用。结论:淫羊藿女贞子配伍延缓衰老的作用与其改善衰老大鼠血清自由基损伤有关。 相似文献