全文获取类型
收费全文 | 68300篇 |
免费 | 6931篇 |
国内免费 | 2066篇 |
专业分类
耳鼻咽喉 | 665篇 |
儿科学 | 1752篇 |
妇产科学 | 625篇 |
基础医学 | 4331篇 |
口腔科学 | 536篇 |
临床医学 | 10735篇 |
内科学 | 12299篇 |
皮肤病学 | 510篇 |
神经病学 | 4834篇 |
特种医学 | 2615篇 |
外国民族医学 | 2篇 |
外科学 | 6851篇 |
综合类 | 12876篇 |
现状与发展 | 3篇 |
预防医学 | 5033篇 |
眼科学 | 967篇 |
药学 | 6690篇 |
103篇 | |
中国医学 | 4462篇 |
肿瘤学 | 1408篇 |
出版年
2024年 | 302篇 |
2023年 | 1192篇 |
2022年 | 2476篇 |
2021年 | 3500篇 |
2020年 | 3442篇 |
2019年 | 2703篇 |
2018年 | 2479篇 |
2017年 | 2908篇 |
2016年 | 2890篇 |
2015年 | 2516篇 |
2014年 | 4700篇 |
2013年 | 4732篇 |
2012年 | 3864篇 |
2011年 | 4066篇 |
2010年 | 3347篇 |
2009年 | 3098篇 |
2008年 | 3167篇 |
2007年 | 3378篇 |
2006年 | 2987篇 |
2005年 | 2529篇 |
2004年 | 2059篇 |
2003年 | 1816篇 |
2002年 | 1559篇 |
2001年 | 1450篇 |
2000年 | 1167篇 |
1999年 | 1023篇 |
1998年 | 845篇 |
1997年 | 793篇 |
1996年 | 695篇 |
1995年 | 707篇 |
1994年 | 625篇 |
1993年 | 481篇 |
1992年 | 534篇 |
1991年 | 419篇 |
1990年 | 356篇 |
1989年 | 308篇 |
1988年 | 299篇 |
1987年 | 280篇 |
1986年 | 221篇 |
1985年 | 237篇 |
1984年 | 227篇 |
1983年 | 141篇 |
1982年 | 167篇 |
1981年 | 110篇 |
1980年 | 88篇 |
1979年 | 96篇 |
1978年 | 99篇 |
1977年 | 49篇 |
1976年 | 57篇 |
1975年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
101.
Lester A. Klein 《Neurourology and urodynamics》1987,6(2):95-99
The trigone sensitivity test, a complementary test to cystometry, has been proposed as a method for distinguishing certain clinical disorders. Pressure is applied to the trigone region of the bladder by pulling upon a Foley catheter with the balloon inflated and the amount of force needed to induce an urge to void is recorded. Although the trigone sensitivity test has been proposed as a test of exteroceptive function, it is possible that deeper receptors, perhaps proprioceptors, are actually responsible for the awareness of the urge to void during the study. The present investigation compared the trigone sensitivity test with provoked detrusor contraction in 107 patients. The findings indicate that variations in the two responses occur independently of each other. It is concluded that different neural pathways are responsible for the two functions. The hypothesis that exteroceptive and not proprioceptive nerves are being measured during trigone sensitivity testing is supported by these findings. 相似文献
102.
Anorectal function in the solitary rectal ulcer syndrome 总被引:8,自引:6,他引:2
Nigel R. Womack F.R.C.S. Professor Norman S. Williams M.S. John H. Holmfield Mist John F. Morrison Ph.d. 《Diseases of the colon and rectum》1987,30(5):319-323
The anorectal function of nine patients with solitary rectal ulcer syndrome (SRUS) (5 F: 4 M, median age, 27 (range, 19–41
years) and nine control subjects (5 F: 4 M, median age, 47 (35–66)P<0.01) has been investigated by a new technique that radiologically visualizes the anorectum during voiding of a semisolid
contrast medium, while simultaneously measuring intrarectal pressure and anal sphincter EMG activity. A degree of rectal prolapse
was demonstrated in eight of the SRUS patients; six of these lesions were clinically occult. Abnormal failure of the anal
sphincter to relax on voiding was present in seven of the SRUS patients. These abnormalities resulted in the SRUS patients
requiring a greater increase in intrarectal pressure (median, 100 cm water) to void than the control subjects (median, 65
cm water,P<0.01). This combination of high intrarectal pressure and rectal prolapse during straining seems to be the cause of SRUS
This work was supported by a grant from the Medical Research Council. 相似文献
103.
A. Jaén J. Sunyer X. Basagaña S. Chinn† J. P. Zock J. M. Antó‡ P. Burney† 《Clinical and experimental allergy》2002,32(12):1713-1719
BACKGROUND: The role of atopy in the evolution to chronic obstructive disease remains controversial. AIM: We aimed to assess the association between individual sensitization to common allergens and lung function. METHOD: We analysed data from 12,687 subjects aged 20 to 44 years, from 34 centres in 15 countries participating in the European Community Respiratory Health Survey (ECRHS). Participants performed a blood test, lung function test, methacholine challenge, and answered an administered questionnaire. The relationships between specific IgE, FEV1 and FEV1/FVC ratio were assessed for each study centre stratified by sex, followed by random effects meta-analysis. RESULTS: Asthmatics sensitized to house dust mite had a lower FEV1 (-119 mL in women and -112 mL in men) and FEV1/FVC ratio (-1.95%, and -2.48%) than asthmatics without sensitization. Asthmatics sensitized to cat had a lower FEV1 (statistically significant for women only) and a lower FEV1/FVC ratio. Asthmatic women sensitized to grass had a lower FEV1 and a lower ratio, and those sensitized to Cladosporium had a lower FEV1. A weak association was found with sensitization to cat and to Cladosporium among non-asthmatic women, which disappeared after adjusting for BHR. CONCLUSION: We conclude that atopy was related to a lower lung function, which was only apparent among asthmatics. This relationship was explained by specific sensitization to cat and to house dust mite, the latter being homogeneous across areas. 相似文献
104.
大蒜素对脑局灶缺血大鼠血小板活化功能及其结构的影响 总被引:13,自引:0,他引:13
目的:观察大蒜素对脑局灶缺血大鼠血小板活化功能或轻药物诱导的血小板活化功能及其结构的影响。方法:(1)将SD大鼠随机分为(空白组、大蒜素大剂量组和小剂量组)3组,于末次给予试药1.5h后颈总动脉插管取血,加入诱导剂二磷酸腺苷(ADP)或胶原,测定血小板最大聚集率;(2)采用化学刺激(FeCl3)诱导血栓闭塞法制备大鼠急性大脑中动脉血栓模型,随机分为(假手术组、模型组、大蒜素大剂量组和小剂量组)4组,给药方法同实验(1),颈总动脉插管取血后分离血浆,测定血浆血栓烷B2(TXB2)、6-酮-前列腺素F1α(6-keto-PGF1α)含量;(3)加入ADP孵育激活性,离心得到血小板沉淀块,透射电镜下观察血小板的超微结构。结果:与空白组或模型组相比,大蒜素大剂量组(10mg/kg)、小剂量组(5mg/kg)均可显著抑制药物诱导的血小板聚集(P<0.01),且大剂量组显著优于小剂量组(P<0.05);均可明显降低模型大鼠血浆TXB2的含量,降低TXB2/6-keto-PGF1α比值,大剂量组还显著升高血浆中6-keto-PGF1α水平(P<0.05,P<0.01);可明显抑制血小板活化过程中超微结构的改变,且有一定的量效关系。结论:大蒜素可能通过抑制血小板聚集,抑制血小板活化时大量释放的活性肽TXA2、促进恢复TXA2/PGI2平衡,抑制血小板激活释放过程中超微结构的改变,从而对脑梗塞起治疗作用。 相似文献
105.
白细胞介素-18基因修饰的胎肝细胞经脾移植对小鼠免疫功能的影响 总被引:2,自引:1,他引:1
目的:观察表达mIL-18的重组腺病毒基因修饰的胎肝细胞(AdmIL-18/BNL.CL2)经脾移植对正常小鼠免疫功能的影响。方法:实验组小鼠经脾移植AdmIL-18/BNL.CL2,同时设LacZ病毒对照组(Ad-LacZ/BNL.CL2),BNL.CL2细胞对照组及空白对照组。2周后处死,留取血清,制备腹腔巨噬细胞、脾淋巴细胞、肝组织匀浆液,提取肝组织总RNA。采用ELISA法检测各组小鼠血清、腹腔Mφ和脾细胞培养上清、肝匀浆中细胞因子的含量;采用半定量RT-PCR法,检测肝组织细胞因子mRNA相对表达量;以LDH释放法测定腹腔Mφ杀伤活性和脾NK细胞活性,用MTT还原比色法测定脾淋巴细胞的增殖活性。结果:实验组小鼠血清、细胞培养上清及肝匀浆中,IL-18、IL-2、IFN-γ、TNF-α稔均高于其它对照组,而IL-4、IL-10水平则低于对照组;半定量RT-PCR结果与ELISA检测结果一致;同时,实验组腹腔Mφ的杀伤活性和脾NK细胞活性,及脾淋巴细胞增殖活性也明显高于对照组。结论:AdmIL-18能有效转染至胎肝细胞并稳定表达mIL-18;AdmIL-18基因修饰的胎肝细胞经脾移植后,可显著提高肝脏、脾脏免疫细胞活性,活化腹腔Mφ,促进Th1类细胞因子表达,抑制Th2类细胞因子的分泌。 相似文献
106.
80例健康青年分别经针刺或艾灸肺俞穴后的肺功能变化 总被引:3,自引:0,他引:3
目的:探讨针刺与艾灸肺俞穴对健康人肺功能的影响。方法:我们选择了20-22岁健康男性80例,随机分为针刺组和艾灸组各40例,于针刺,艾灸前和针刺,艾灸后10min测试用力肺活量(FVC),用力呼气量(FEV1.0),最大呼气中段流速(MMF),最大呼气流量(PEFR),75%,50%,25%肺活量时的最大呼气流速(V75,V50,V25),结果:显示经针刺和艾灸肺俞穴后2组FVC,FFV1.0均显著增加,P<0.05,2组间比较针刺组FVC明显高于艾灸组,P<0.05,而且艾灸组MMF,V25亦显著降低P<0.05,结论:健康人经针刺和艾灸肺俞穴后均可使大气道阻力减少,肺容量增加,提示一定量的艾燃烧后的烟雾可使健康人肺功能受到影响,使肺的小气道收缩,出现阻塞性改变。 相似文献
107.
目的:评价变应性哮喘患儿血清嗜酸性粒细胞阳离子蛋白(S-ECP)水平改变及其意义。方法:测定25例哮喘发作期患儿糖皮质激素吸入治疗12周前后,及20例未予糖皮质激素吸入治疗的哮喘缓解期患儿S-ECP水平,并对发作期患儿S-ECP水平变化与血嗜酸性粒细胞计数(B-EOS)、肺功能一秒用力呼气量(FEV1)、一秒用力呼气量比用力肺活量(FEV1/FVC)及症状评分的关系作相关性分析。结果:哮喘发作组治疗后S-ECP水平较治疗前显著降低,与对照组(健康儿童10名)比较差异无显著性;哮喘缓解组S-ECP水平明显高于发作组治疗后,但明显低于发作组治疗前。哮喘发作组治疗前S-ECP水平变化与B-EOS无相关性,与FEV1、FEV1/FVC呈负相关,与症状评分呈正相关。结论:监测S-ECP水平可作为评价哮喘气道炎症程度、病情预后和指导抗炎治疗的有效指标。 相似文献
108.
Christopher G. Acker Richard Flick Ron Shapiro Velma P. Scantlebury Mark L. Jordan Carlos Vivas Arthur Greenberg John P. Johnson 《American journal of transplantation》2002,2(1):57-61
Delayed graft function (DGF) in cadaver kidney transplants is a common problem and is often due to acute tubular necrosis (ATN). DGF in transplants may have a deleterious effect on long-term graft survival. Since thyroid hormone has been shown to hasten recovery from ATN in experimental models, we designed a trial to determine if a defined course of triiodothyronine (T3) would improve the short- or long-term outcome of patients with DGF in cadaveric transplants. A prospective, randomized, placebo controlled, double blind trial of T3 was carried out in patients with DGF in cadaveric renal transplants. End-points were percentage requiring dialysis, percentage recovering function, time to recovery and length of hospital stay. Long-term outcomes were percentage grafts functioning at 1 year and mean serum creatinine at 1 year. Forty-four patients were randomized to receive either T3 or placebo. Three patients were dropped from each group when early biopsies disclosed that DGF was due to rejection. The groups were well matched by age, cold ischemia time of the graft, and percentage reactivity to a random panel of antigens. Baseline thyroid function studies, including T3, reverse T3 (rT3), and thyroid stimulating hormone (TSH) levels, were similar between the two groups and typical of 'euthyroid-sick syndrome'. T3 had no effect on percentage requiring dialysis, time to recovery, percentage recovering function, or length of stay. At 1 year follow-up, graft function was similar in both groups and significantly lower than that seen in patients with good initial function. Thyroid hormone, given early in the course of DGF in cadaver kidney recipients, had no effect on the course of DGF. Long-term graft function is impaired in patients who experience post-transplant DGF compared to those who have good initial function. 相似文献
109.
荷包环扎式结直肠吻合保肛术治疗低位直肠癌* 总被引:1,自引:1,他引:0
目的 :评价荷包环扎式结直肠吻合保肛术治疗低位直肠癌的价值。方法 :对低位直肠癌采用荷包环扎结直肠吻合保肛术治疗 2 3例 (A组 ) ,采用Miles手术治疗 2 6例 (B组 )。结果 :A组术后 1、3年生存率分别为 10 0 % (2 3/ 2 3) ,95 7% (2 2 / 2 3) ,术后无局部复发病例 ;排便功能优 16例 (6 9 6 % ) ,良 7例 (30 4 % )。B组术后 1、3年生存率分别为 10 0 % (2 6 / 2 6 ) ,96 2 % (2 5 /2 6 ) ,术后局部复发率 3 8% (1/ 2 6 )。两组术后 1、3年生存率 ,局部复发率经统计检验 ,均无显著差异 (P值均 >0 0 5 )。术后并发症 :A组无吻合口瘘及吻合口狭窄发生 ,盆腔感染 1例。B组 :切口感染 1例 ,人工肛门狭窄 1例。结论 :采用螺纹支架管荷包环扎结直肠吻合保肛术治疗低位直肠癌既能达到根治目的 ,又有保留肛门的良好排便功能 ,且并发症少 ,操作简便易行 ,不用特殊器械 ,值得推广应用 相似文献
110.
目的:观察小鼠胃肠运动昼夜节律及药物对节律的影响。方法:小鼠不同时间点灌胃给予蒸馏水及实验药物,同步测定胃排空及小肠推进运动情况。结果:小鼠胃排空及小肠推进运动存在昼夜节律;普瑞博思促进胃肠运动存在时间效应,但对节律无明显影响;阿托品抑制胃肠运动可使原有昼夜节律消失。结论:小鼠胃肠运动功能存在昼夜节律,药物对胃肠运动功能的作用存在时间效应,可使节律发生不同变化。 相似文献