全文获取类型
收费全文 | 29693篇 |
免费 | 1681篇 |
国内免费 | 639篇 |
专业分类
耳鼻咽喉 | 123篇 |
儿科学 | 624篇 |
妇产科学 | 1082篇 |
基础医学 | 1197篇 |
口腔科学 | 447篇 |
临床医学 | 10240篇 |
内科学 | 4532篇 |
皮肤病学 | 251篇 |
神经病学 | 1143篇 |
特种医学 | 1672篇 |
外国民族医学 | 3篇 |
外科学 | 2459篇 |
综合类 | 4758篇 |
现状与发展 | 1篇 |
预防医学 | 836篇 |
眼科学 | 532篇 |
药学 | 1230篇 |
11篇 | |
中国医学 | 264篇 |
肿瘤学 | 608篇 |
出版年
2024年 | 89篇 |
2023年 | 397篇 |
2022年 | 523篇 |
2021年 | 753篇 |
2020年 | 820篇 |
2019年 | 828篇 |
2018年 | 691篇 |
2017年 | 699篇 |
2016年 | 718篇 |
2015年 | 740篇 |
2014年 | 1521篇 |
2013年 | 1622篇 |
2012年 | 1420篇 |
2011年 | 1741篇 |
2010年 | 1526篇 |
2009年 | 1470篇 |
2008年 | 1545篇 |
2007年 | 1604篇 |
2006年 | 1680篇 |
2005年 | 1537篇 |
2004年 | 1354篇 |
2003年 | 1130篇 |
2002年 | 1006篇 |
2001年 | 978篇 |
2000年 | 744篇 |
1999年 | 707篇 |
1998年 | 642篇 |
1997年 | 554篇 |
1996年 | 483篇 |
1995年 | 444篇 |
1994年 | 355篇 |
1993年 | 281篇 |
1992年 | 246篇 |
1991年 | 224篇 |
1990年 | 179篇 |
1989年 | 113篇 |
1988年 | 109篇 |
1987年 | 76篇 |
1986年 | 73篇 |
1985年 | 97篇 |
1984年 | 72篇 |
1983年 | 51篇 |
1982年 | 56篇 |
1981年 | 27篇 |
1980年 | 18篇 |
1979年 | 12篇 |
1978年 | 18篇 |
1977年 | 12篇 |
1976年 | 12篇 |
1975年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
妇科盆腔肿块超声误诊漏诊原因分析 总被引:4,自引:0,他引:4
本文报道经手术病理证实的167例妇科盆腔肿块超声检查结果,超声诊断总的符合率为90.42%(151/167)。其中子宫肌瘤、畸胎瘤、卵巢囊肿、卵巢囊腺瘤以及卵巢交响癌符合率较高,对于其它疾病引起的盆腔肿块也有参考价值,本文着重分析误诊漏诊原因,以吸取教训,供超声诊断借鉴。 相似文献
72.
HIDEKI TASHIRO M.D. SAMON KOYANAGI M.D. AKIRA TAKESHITA M.D. 《Echocardiography (Mount Kisco, N.Y.)》1993,10(4):343-350
To elucidate the pathogenesis of mitral regurgitation (MR) after myocardial infarction (MI), the incidence of papillary muscle dysfunction (PMD), mitral annular size, and the extent of wall-motion abnormalities were examined in 81 patients with previous MI by two-dimensional echocardiography and real-time two-dimensional Doppler flow imaging. The prevalence of pathological MR was lower in patients with anterior MI (36%) than in those with inferior (65%) or anterior and inferior MI (88%) (P < 0.01 vs anterior MI group). The incidence of PMD in patients with MR in the anterior MI group (15%) was lower than that in the inferior (50%, P < 0.01) or anterior and inferior MI group (43%, P < 0.05). The mitral annular dimension in patients with MR was significantly greater than in those without MR, but it was similar among the three groups. The extent of wall-motion abnormality correlated significantly with the area of MR jet in the anterior MI group (y = 3.1x + 15.5, r = 0.52, P < 0.01) and in the inferior MI group (y = 8.3x + 32.7, r = 0.57, P < 0.01). However, the slope of this relationship was significantly steeper in the inferior MI group than in the anterior MI group (P < 0.05). These results indicated that the degree of MR with inferior MI was greater than with anterior MI for a given MI area. PMD may play an important role in the higher prevalence and greater degree of MR in inferior MI. 相似文献
73.
目的 探讨应用彩色多普勒超声显像方法对正常人足部动脉的解剖结构进行无损伤检测的可行性。方法 应用彩色多普勒检测对正常 32人 6 4足的足背、跖背、跖底动脉行径、来源与口径进行探测。结果 6 4足中 1 6只检测到足背动脉弓 ,出现率为 2 5 % ,36足检测到第二跖背动脉 ,出现率为 5 6 2 % ,37足检测到第二跖底动脉 ,出现率为 5 7 8% ;1例足背动脉缺如 ,占 1 6 % ,其第一跖背动脉来源于腓动脉。 5 9足检测到第一跖背动脉 ,出现率为 92 2 % ,其中 ,顾玉东Ⅰ型 ,占 2 8 1 % ,Ⅱ型 ,占 4 6 9% (30例 ) ,6足为ⅢS 型 ,占 9 4 % ,正常人足部动脉彩超结果表明 ,5足为Ⅵ型 ,占 7 8%。结论 应用彩色多普勒超声显像的方法可以对足部动脉的解剖结构进行无损伤的检测 ;以足背动脉为共同血管蒂 ,第一、二跖背 (底 )为动脉蒂共干同时移植拇趾皮甲瓣和第二足趾 (或二、三足趾 ) ,扩大再造手的虎口 ,改进现有单足供趾再造手技术的方法是可行的 相似文献
74.
Early assessment of renal resistance index after kidney transplant can help predict long-term renal function. 总被引:6,自引:0,他引:6
Angelo Saracino Giovanni Santarsia Angela Latorraca Vito Gaudiano 《Nephrology, dialysis, transplantation》2006,21(10):2916-2920
BACKGROUND: Color Doppler ultrasonography of intrarenal arterial resistance index (RI), performed early after kidney transplant, has proven to reliably predict short-term allograft function. The aim of this study was to assess whether it could also predict long-term renal function. METHODS: We retrospectively analysed 76 kidney transplant patients who underwent RI assessment within 1 month after the transplant, subdivided into two groups according to RI values, lower (group A) or higher (group B) than its median value (0.635). RESULTS: Compared with group A subjects, the patients of group B were older at the time of transplant (42 +/- 9 vs 35 +/- 8 years; P = 0.001), the donor age was also older (41 +/- 16 vs 33 +/- 13 years; P = 0.02) and had a slightly higher proteinuria (0.54 +/- 0.5 vs 0.32 +/- 0.2 g/24 h; P = 0.02). Serum creatinine, ciclosporin or tacrolimus trough level, arterial blood pressure, number of human leukocyte antigen (HLA) mismatches, anti-hypertensive medications and incidence of delayed graft function were not significantly different between the two groups. By univariate analysis, RI turned out to directly correlate with the recipient age, donor age and daily proteinuria (P = 0.007, P = 0.0007 and P = 0.02, respectively). Multivariate analysis showed that only donor and recipient age maintained their independent predictive value on RI. Kaplan-Meier analysis, considering a serum creatinine increase >50% as the endpoint of the study, showed a statistically significant different graft survival in the two groups (log-rank test = 5.489; P = 0.01). The univariate relative risk of deterioration of graft function among patients with higher RI was 3.77. Proteinuria and recipient age increased the risk as well. CONCLUSIONS: Our data seem to suggest that early determination of RI can help predict long-term graft function in kidney transplant recipients. 相似文献
75.
目的 探讨冠状动脉瘘的影像特征、鉴别诊断及彩色多普勒超声在飞行员改装体检中的医学鉴定价值.方法 分析1例飞行员左冠状动脉-肺动脉瘘超声图像特征并复习相关文献.探讨应用彩色多普勒超声检查在飞行员改装体检中的必要性.结果 彩色多普勒超声显示心底部心肌间走行迂曲的异常血流束,经主肺动脉外侧壁注入肺动脉内.超声诊断:左冠状动脉-肺动脉瘘.飞行结论:改装并原机种飞行不合格结论彩色多普勒超声检查能清晰显示冠状动脉瘘,并能追踪观察其走行、部位、内径和大小,超声诊断与冠状动脉造影结果相符.冠状动脉瘘早期无特异性临床表现,彩色多普勒超声心动图诊断冠状动脉瘘直接、安全、快捷,具有重要的临床价值,是明确诊断的首选方法. 相似文献
76.
Detection of microemboli in the subclavian vein of patients undergoing haemodialysis and haemodiafiltration using pulsed Doppler ultrasound. 总被引:1,自引:1,他引:0
Dirk W Droste Karsten Kühne Roland M Schaefer E Bernd Ringelstein 《Nephrology, dialysis, transplantation》2002,17(3):462-466
BACKGROUND: The pathophysiology leading to pulmonary side effects during haemodialysis and haemodiafiltration is not yet fully understood. Chronic microembolization, which can be demonstrated by pulsed Doppler ultrasound, may be one cause. METHODS: The study cohort consisted of 24 long-term dialysis patients undergoing haemodialysis (n=21) and online-haemodiafiltration (n=3), respectively. The subclavian vein downstream to the venous access was investigated during different phases of the procedure using a 2-MHz pulsed ultrasound device. RESULTS: In all periods investigated (connection, dialysis, disconnection), numerous microembolic signals (MES) were found in the subclavian vein. The numbers of MES detected during haemodiafiltration (314-709 MES per 10 min) were higher than during haemodialysis (0-81 MES per 10 min). CONCLUSIONS: The composition (gaseous or solid) and origin (pump, tubing system or shunt) of the microemboli detected remains unclear. Chronic microembolization may be one cause of pulmonary complications of haemodialysis and haemodiafiltration. The detection method described in this article will help us to better understand this process and to determine what role microemboli might play in pulmonary and central nervous system disorders. It may also help to optimize the devices and techniques used. 相似文献
77.
K. H. Vogelberg M. Mühl M. Köhler 《Journal of molecular medicine (Berlin, Germany)》1987,65(15):713-718
Summary Seventy-five diabetic and 40 nondiabetic subjects who where suffering from peripheral vascular disease were studied in order to determine whether the degree of the severity of their disease can be better calculated by Doppler ultrasound examinations of the peak velocity than by the systolic pressure of the peripheral bloodstream. In 46 examinations of normal controls the mean value of the peak velocity was 13.3±3.3 cm/s with a standard deviation of 15.4%±13.2% on one day and 16.1%±15.9% on different days. Considering patients with or without diabetes mellitus the velocity was significantly decreased in correlation to an increasing degree of severity of the vascular disease (P<0.001); however, the decrease was lower in diabetic than in nondiabetic subjects (6.9±2.8 vs 4.6±6.2,P<0.05). The systolic pressure hardly decreased, but remained higher in all stages of peripheral vascular disease of diabetics than in the nondiabetic subject (P<0.05 toP<0.005). There was a significant decrease of the systolic pressure only in diabetic subjects with the most advanced degree of the disease, i.e. stage IV (P<0.05).It is concluded from this study that Doppler ultrasound measurements of the peak velocity of the peripheral bloodstream are a useful parameter to calculate the degree of severity of the peripheral vascular disease. In addition, it is concluded than peak velocity is an even better prognostic indicator of peripheral vascular disease than is measurement of the systolic blood pressure at the feet.
Abkürzungen AVK periphere arterielle Verschlußkrankheit - USDI Ultraschall-Doppler-Index - MSBG maximale Blutströmungsgeschwindigkeit - HFV Herzfrequenzvariation 相似文献
Abkürzungen AVK periphere arterielle Verschlußkrankheit - USDI Ultraschall-Doppler-Index - MSBG maximale Blutströmungsgeschwindigkeit - HFV Herzfrequenzvariation 相似文献
78.
目的:认识睾丸微石症(TM)的临床意义和诊断方法。方法:回顾性报告2例TM病例的临床资料,结合文献进行讨论。结果:2例分别因左精索静脉曲张和附睾炎就诊的患者行阴囊超声检查时发现睾丸内散在多发点状强回声,如针尖样,1~2mm,后无声影。分别诊断为局部TM、左精索静脉曲张和TM,左附睾炎。甲胎蛋白、人绒毛膜促性腺激素、乳酸脱氢酶和睾酮等检查均正常。对睾丸微石症未做特殊处置,随访6~8个月,体检和睾丸瘤标未见异常,阴囊超声睾丸图像无特征性改变。结论:TM是一种少见、无明显临床症状、相对稳定的疾病。多因阴囊其他疾病行超声检查时偶然发现,其是否属于癌前病变尚有争议,但是定期随访和阴囊超声检查是必要的。 相似文献
79.
目的探讨二维超声和彩色多普勒血流显像(cDFI)对移植胰腺的功能和术后并发症的监测作用。方法用彩色多普勒超声观察6例移植胰腺的形态和血流动力学变化情况。结果(1)功能正常的移植胰腺在术后形态正常,体积偏大,主胰管内径正常,实质回声较正常胰腺略高,动脉PSV13~64cm/s,R10.44~0.68,P10.67~2.33。(2)2例出现急性排异和1例出现移植胰腺炎的移植胰腺周边出现低或无回声区,实质回声明显减低,分布不均。1例急性重度排异的RI值超过0.9,而另1例急性轻度排异RI值小于0.7。1例移植胰腺炎RI值超过0.9,PI值超过4.0。结论CDFI作为一种无创的检查技术对胰腺移植术后的监测和诊治具有积极意义。 相似文献
80.