全文获取类型
收费全文 | 16033篇 |
免费 | 2527篇 |
国内免费 | 370篇 |
专业分类
耳鼻咽喉 | 126篇 |
儿科学 | 714篇 |
妇产科学 | 361篇 |
基础医学 | 1485篇 |
口腔科学 | 194篇 |
临床医学 | 2048篇 |
内科学 | 4691篇 |
皮肤病学 | 319篇 |
神经病学 | 1315篇 |
特种医学 | 304篇 |
外科学 | 2127篇 |
综合类 | 1135篇 |
现状与发展 | 1篇 |
一般理论 | 5篇 |
预防医学 | 1485篇 |
眼科学 | 693篇 |
药学 | 793篇 |
2篇 | |
中国医学 | 188篇 |
肿瘤学 | 944篇 |
出版年
2024年 | 55篇 |
2023年 | 429篇 |
2022年 | 236篇 |
2021年 | 438篇 |
2020年 | 418篇 |
2019年 | 198篇 |
2018年 | 755篇 |
2017年 | 756篇 |
2016年 | 810篇 |
2015年 | 780篇 |
2014年 | 707篇 |
2013年 | 967篇 |
2012年 | 979篇 |
2011年 | 944篇 |
2010年 | 828篇 |
2009年 | 837篇 |
2008年 | 758篇 |
2007年 | 759篇 |
2006年 | 579篇 |
2005年 | 705篇 |
2004年 | 1136篇 |
2003年 | 962篇 |
2002年 | 741篇 |
2001年 | 662篇 |
2000年 | 288篇 |
1999年 | 328篇 |
1998年 | 361篇 |
1997年 | 292篇 |
1996年 | 136篇 |
1995年 | 98篇 |
1994年 | 84篇 |
1993年 | 105篇 |
1992年 | 90篇 |
1991年 | 52篇 |
1990年 | 60篇 |
1989年 | 59篇 |
1988年 | 56篇 |
1987年 | 45篇 |
1986年 | 38篇 |
1985年 | 22篇 |
1984年 | 20篇 |
1983年 | 19篇 |
1982年 | 19篇 |
1981年 | 22篇 |
1980年 | 14篇 |
1977年 | 13篇 |
1975年 | 13篇 |
1974年 | 18篇 |
1968年 | 17篇 |
1928年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
151.
Klootwijk P.; Langer A.; Meij S.; Green C.; Veldkamp R. F.; Ross A. M.; Armstrong P. W.; Simoons M. L.; for the GUSTO-I ECG-ischaemia monitoring substudy 《European heart journal》1996,17(5):689-698
In the GUSTO-I ECG ischaemia monitoring substudy, 1067 patientsunderwent continuous ST segment monitoring, using vector-derived12-lead (406 patients), 12-lead (373 patients) and 3-lead Holter(288 patients) ECG recording systems. Simultaneous angiogramsat 90 or 180 min following thrombolytic therapy were performedas a part of the prospective study in 302 patients. Infarct vessel patency was established as TIMI perfusion grades2 or 3 and occlusion as TIMI perfusion grades 0 or 1. Coronaryartery patency was predicted from ST trends up to the time ofangiography. Predictive values at 90 and 180 min after the startof thrombolysis were 70% and 82% for patency and 58% and 64%for occlusion, respectively. In retrospect, accuracy appearedgreatest (79100%) in patients with extensive ST segmentelevation (400 µV), if both speed of ST recovery and extentof ST segment: elevation were taken into account. Although thethree recording systems differed considerably in signal processing,no significant difference in accuracy was demonstrated amongthese systems. We conclude that continuous ECG monitoring may help select highrisk patients without apparent reperfusion who may benefit fromadditional reperfusion therapy. As ST recovery may occur earlyafter the start of thrombolytics and accuracy of the test isrelated to peak ST levels, the use of on-line ECG monitoringdevices on emergency wards and cardiac care units is recommended.(Eur Heart J 1996; 17: 689698) 相似文献
152.
Matousovic K.; Elseviers M. M.; Devecka D.; Horackova M.; Turek T.; De Broe M. E.; the Group of Czech Slovak Nephrologists 《Nephrology, dialysis, transplantation》1996,11(6):1048-1051
BACKGROUND.: The occurrence of analgesic nephropathy (AN) among renal replacementtherapy patients in former Czechoslovakia is not known. Previoussurveys were not based on representative samples and lackeduniform criteria for diagnosing the disease. METHODS.: Incidence of AN in former Czechoslovakia was investigated inpatients commencing renal replacement therapy in 24 (1/3 ofall) dialysis centres from 1 January to 31 December 1992. Patientsshowing an unclear renal diagnosis (n=149) were investigatedwith an interview and renal imaging techniques. The diagnosisof AN was withheld or rejected on the base of recently publisheddiagnostic criteria demonstrating that a decreased renal massof both kidneys combined with bumpy contours and/or papillarycalcifications had a high performance for diagnosing AN (NephrolDial Transplant 1992; 7: 479486). RESULTS.: Based on the renal imaging criteria, AN was diagnosed in 30of 328 registered patients, resulting in an AN incidence of9.1% while the EDTA data only mentioned an incidence of 4.8%(period 19861989). The products most commonly abusedwere analgesic mixtures containing two analgesic substancescombined with caffeine and/or codeine. CONCLUSIONS.: AN was found to be a common disease in the Czech and SlovakRepublics. The disease was diagnosed using reliable renal imagingcriteria. 相似文献
153.
154.
155.
International Workshop on the Impact of the Environment on Reproductive Health 《Progress in human reproduction research》1991,(20):1-11
The WHO workshop on the impact of the environment on reproductive health is summarized. Topics include the nature of environmental factors affecting reproductive health, environmental factors blamed for declining sperm quantity and quality, the effects of natural and man-made disasters on reproductive health, chemical pollutants, how the environment damages reproductive health, and research needs for better research methodologies and surveillance data. Recommendations are made to: 1) promote international research collaboration with an emphasis on consistency of methodological approaches for assessing developmental and reproductive toxicity, on development of improved surveillance systems and data bases, an strengthening international disaster alert and evaluation systems; 2) promote research capabilities for multidisciplinary studies, for interactive studies of the environment and cellular processes, and for expansion of training and education; and 3) take action on priority problems of exposure to chemical, physical, and biological agents, of exposure to pesticides among specific populations, and of inadequate screening methods for identification of environmental chemicals. The costs of environmental injury to reproduction include subfertility, intrauterine growth retardation, spontaneous abortion, and various birth defects. Developed country's primary threats are from chemical pollution, radiation, and stress. There is a large gap in knowledge. Caution is urged in understanding the direct relationship between environmental causes and infertility. Sexual health is difficult to assess and research is suggested. Exposure to excessive vitamin A and toxic chemicals are cited as agents probably having serious effects on malformations. Sperm quality has declined over the decades; there is speculation about the potential causes. The effects of radiation such as at Chernobyl are described. Toxic chemical exposure such as in Bhopal, India killed thousands. Neurological damage is reported for fetuses and infants exposed to methyl mercury. There is the beginning of evidence that complications of pregnancy may be related to pollution levels surrounding industrial plants. Reproductive health is affected through chromosome damage and cell destruction, prenatal death, altered growth, fetal abnormalities, postnatal death, functional learning deficits, and premature aging. 相似文献
156.
目的:探讨多药耐药集团(MDR1)在小细胞肺癌化疗中的作用和地位,方法:采用逆转录-多聚酶链式反应技术(RT/PCR)和免疫细胞化学染色法,检测了32例(初治原发癌21例和复治转移癌11例)小细胞肺癌患者血液中的MDR1mRNA水平和多药耐药蛋白(P-170)的表达,并对两种方法进行了比较。结果:初治的原发癌MDR1基因阳性表达率为14.29%,P-170蛋白阳性表达为14.27%,复治转移癌的MDR1基因阳性表达率为72.73%,P-170蛋白阳性表达为63.64%(P<0.01),有显著性差异。MDR1的基因和蛋白两种而检测方法具有一定的一致性,以RT/PTR方法具有更强的敏感性,结论:复治转移癌组比初治组具有更普遍的抗药性,且主要是获得性抗药,MDR1基因表达可作为临床合理地制定化疗方案,预测化疗效果的重要参考指标。 相似文献
157.
抗菌药使用现状调查分析 总被引:1,自引:0,他引:1
目的:了解我院抗菌药使用现状,为完善抗菌药管理提供科学的依据。方法:横断面调查研究。结果:全院当日使用抗菌药共8类36种,抗菌药使用率为52.3%,头孢菌素类抗菌药排在使用首位,外科抗菌药使用率高于内科;病原微生物送检率为3.8%,送检率低,治疗多为经验用药;预防用药指征过宽,时间过长。结论:提高病原学送检率,根据微生物学检查和药敏结果合理使用抗菌药,建立抗菌药使用登记制度,开发抗菌药使用信息管理系统,是促使临床合理使用抗菌药的措施。 相似文献
158.
喉鳞癌瘤内微血管及微淋巴管形态计量研究及临床意义 总被引:2,自引:0,他引:2
目的:研究喉鳞癌瘤内微血管和微淋巴管形态、分布、密度,以及相关临床意义。方法:采用5’-Nase-AlPase双重酶组织化学法和HE染色对40侧喉鳞癌标本冰冻切片进行研究。结果:光镜下微血管呈蓝色,微淋巴管呈棕色。除转移组微血管密度显著高于未转移组外,与其余临床指标均未见相关性。结论:瘤内微血管密度与淋巴转移有明显相关,而微淋巴管密度未发现明显临床意义,其机制待深入研究。 相似文献
159.
目的:介绍枕下-颞下联合入路切除颞骨良性肿瘤的方法及体会。方法:对3例颞枕骨化纤维瘤、颞骨纤维异常增殖症、颞骨血管瘤的巨大颞骨良性肿瘤,均采用枕下-颞下联合入路(倒钩形切口)。辅以显微外科技术进行手术摘除肿瘤。结果:3例均基本完整切除肿瘤,无颅内外感染、脑脊液漏、迷路及颅神经损伤等并发症,经术后随访1.5年~2年未发现肿瘤复发。结论:采用枕下-颞下联合入路切除颞枕骨良性肿瘤可获理想的暴露,最大范围切除肿瘤,可避免损伤毗邻的颅神经、血管以及内耳结构,值得推广。 相似文献
160.
重度阻塞性睡眠呼吸暂停低通气综合征围手术期持续正压通气治疗 总被引:1,自引:0,他引:1
目的 观察重度阻塞性睡眠呼吸暂停低通气综合征 (obstructivesleepapneahypopneasyndrome ,OSAHS)围手术期病情变化和持续正压通气治疗 (continuouspositiveairwaypressure,CPAP)的影响 ,探讨围手术期治疗的必要性。方法 45例重度OSAHS患者均接受了完整保留悬雍垂的改良悬雍垂腭咽成形术。其中 2 4例不做围手术期CPAP治疗的作对照组 ,2 1例行围手术期CPAP治疗 :术前CPAP治疗 7d以上 ,于术后 1~ 3d夜应用自动调节治疗压力的CPAP(autotitratedCPAP ,AutoSet)进行治疗。治疗组患者术后第二夜在AutoSet治疗下同时做多导睡眠监测 (polysomnography,PSG)。对呼吸暂停低通气指数 (apneahyponeaindex ,AHI)、最低血氧饱和度 (lowestSaO2 ,LSaO2 )、血压以及睡眠结构等指标进行观察。结果 对照组 2 4例患者中有 6例于术后第二夜LSaO2 比术前下降 ,AHI升高 ,另外 1 8例患者LSaO2 升高 ,AHI下降。治疗组 2 1例患者CPAP治疗前AHI为 (61 1± 9 9)次 /h( x±s,以下同 ) ,LSaO2 为 65 0 %± 9 6 % ,手术前CPAP治疗后AHI为 (2 2± 1 4)次 /h ,LSaO2 为 94 5 %± 2 9% ,t检验P <0 0 0 1 ;手术前经CPAP治疗临床症状消失。术后患者均能良好耐受AutoSet治疗 ,术后第二夜应用AutoSet治疗时AHI为 (3 6± 1 8)次 /h 相似文献