全文获取类型
收费全文 | 195篇 |
免费 | 42篇 |
国内免费 | 1篇 |
出版年
2024年 | 1篇 |
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 6篇 |
2019年 | 6篇 |
2018年 | 9篇 |
2017年 | 14篇 |
2016年 | 8篇 |
2015年 | 11篇 |
2014年 | 13篇 |
2013年 | 15篇 |
2012年 | 6篇 |
2011年 | 10篇 |
2010年 | 6篇 |
2009年 | 5篇 |
2008年 | 9篇 |
2007年 | 11篇 |
2006年 | 13篇 |
2005年 | 9篇 |
2004年 | 9篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 2篇 |
2000年 | 3篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1997年 | 5篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 3篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1973年 | 3篇 |
排序方式: 共有238条查询结果,搜索用时 15 毫秒
81.
82.
Food allergies have become increasingly prevalent during the past few decades. Diarrhea is one of the most frequent intestinal symptoms caused by food allergens and is characterized by imbalanced ion exchange and water transfer; however, the underlying mechanism of allergic diarrhea remains unclear. Water transfer across the intestinal epithelial membrane seems to occur via aquaporins (AQPs). However, the molecular mechanism of water transfer and the pathophysiological roles of aquaporins in the intestine have not been fully established. The present studies have focused on the alterations of AQPs in a mouse model of allergic diarrhea in which BALB/c mice developed diarrhea following repeated challenges of orally administered ovalbumin. Quantitative real-time PCR analysis and immunohistochemical technique were used for expression of mRNA and protein of AQPs, respectively. AQP4 and AQP8 mRNA levels were significantly decreased in the proximal colon of allergic mice compared to controls; likewise, expression of AQP4 and AQP8 proteins was reduced in the proximal colon of the allergic mice. These results suggest that allergic diarrhea is associated with a downregulation in AQP4 and AQP8 expression. 相似文献
83.
Petar Liovic Ilija D. Šutalo Silvana F. Marasco 《Computer methods in biomechanics and biomedical engineering》2014,17(9):944-957
The stress on an intramedullary screw rib fixation device holding together a centrally fractured human rib under in vivo force loadings was studied using finite element analysis (FEA). Validation of the FEA modelling using pullout from porcine ribs proved FEA to be suitable for assessing the structural integrity of screw/bone systems such as rib fixated by a screw. In the human rib fixation investigation, it was found that intramedullary bioresorbable Bioretec screws can fixate centrally fractured human ribs under normal breathing conditions. However, under coughing conditions, simulation showed Bioretec fixating screws to bend substantially. High stresses in the screw are mainly the result of flexion induced by the force loading, and are restricted to thin regions on the outside of the screw shaft. Stiffer screws result in less locally intense stress concentrations in bone, indicating that bone failure in the bone/screw contact regions can be averted with improvements in screw stiffness. 相似文献
84.
A common feature of reinforcer devaluation studies is that new learning induces the devaluation. The present study used extinction to induce new learning about the conditioned reinforcer in a heterogeneous chain schedule. Rats pressed a lever in a heterogeneous chain schedule to produce a conditioned reinforcer (light) associated with the opportunity to obtain an unconditioned reinforcer (food) by pulling a chain. The density of food reinforcement correlated with the conditioned reinforcer was varied in a comparison of continuous and variable-ratio reinforcement schedules of chain pulling; this had no noticeable effect on conditioned reinforcer devaluation produced by extinction of chain pulling. In contrast, how rats were deprived appeared to matter very much. Restricting meal duration to 1h daily produced more lever pressing during baseline training and a greater reductive effect of devaluation on lever pressing than restricting body weight to 80% of a control rat's weight, which eliminated the devaluation effect. Further analysis suggested that meal-duration restriction may have produced devaluation effects because it was more effective than weight restriction in reducing rats' body weights. Our results exposed an important limitation on the devaluation of conditioned reinforcers: slight differences in food restriction, using two commonly employed food-restriction procedures, can produce completely different interpretations of reinforcer devaluation while leaving reinforcer-based learning intact. 相似文献
85.
郭明君胡运生赵海恩郑联合张勇马保安 《现代生物医学进展》2012,12(6):1081-1083
目的:本研究通过观察微创锁定钢板接骨术治疗老年股骨近端粉碎骨折临床效果,旨在找出最佳治疗方式。方法:自2007年12月~2010年03月,应用股骨近端锁定加压钢板治疗老年股骨近端粉碎骨折23例。记录术中出血量、手术时间,术后并发症、骨折愈合时间及最后一次随访时功能恢复情况。结果:骨折临床愈合时间为12~28周,平均16周。除1例患者髋内翻畸形,1例锁定加压钢板断裂外,其他患者均达到骨性愈合。结论:股骨近端锁定钢板具有创伤小、固定可靠、骨折愈合快、功能恢复满意的特点,尤其适用于老年股骨近端粉碎骨折。 相似文献
86.
郑联合王育才张云飞于哲陈翔 《现代生物医学进展》2012,12(10):1876-1878
目的:探讨逆行交锁髓内钉联合单侧骨皮质钢板固定治疗股骨髁上骨不连的临床疗效。方法:对25例股骨髁上骨不连,均采用逆行交锁髓内钉联合单侧骨皮质钢板固定加自体髂骨植骨治疗。结果:25例获12~24个月随访,平均12个月。4~8个月内均获骨性愈合。结论:应用逆行交锁髓内钉联合单侧骨皮质钢板固定后骨折端可获得坚强内固定,手术操作简便、安全,可早期进行膝关节和股四头肌功能锻炼,是一种治疗股骨髁上骨不连的有效方法。 相似文献
87.
目的:分析应用新一代股骨近端髓内钉( InterTan)治疗股骨近端骨折的早期临床疗效.方法:回顾性分析2009年9月至201 1年8月我科共收治股骨近端骨折患者共107例,均采用InterTan髓内钉系统进行治疗,其中男45例,女62例;年龄34-93岁,平均73.05岁.受伤肢体左侧63例,右侧44例.按AO分型,31-A1型32例,31 -A2型59例,31-A3型16例.记录患者手术持续时间、并发症、死亡率、骨折愈合时间、末次复查Harris评分,并对比患者健侧及患侧术前、术中及术后1周的颈干角变化.所有数据采用SPSS 13.0进行统计分析.结果:平均手术持续时间为66.69分钟.颈干角:术前健侧:140.66±9.08度,术前患侧:118.00± 15.49度,术中患侧:135.16± 7.08度,术后1周患侧:137.51±15.21度.术前患侧颈干角与其他三组相比均有显著性差异(P<0.05),术前健侧、术中复位后患侧、术后1周患侧颈干角之间相比均无显著性差异.3例患者于随访过程中死亡,6例患者失访.98例患者获得随访,随访时间3 -22个月,平均8.6个月.2例患者发生头钉切出,3例患者术后练习后出现股骨疼痛症状,未发生股骨干骨折.96例患者均获得骨性愈合,骨折愈合时间12~18周.临床疗效按Harris评分标准:41-92分,平均78.5分,优良率80.6%.结论:髓内钉InterTan是治疗股骨近端骨折的良好选择. 相似文献
88.
The external morphology of a fragmentary right proximal femur from southwestern Uganda is described here. Discovered in the Kikorongo Crater of Queen Elizabeth National Park in 1961, this specimen was informally assigned to Homo sapiens (although never described) and tentatively dated to the late Pleistocene. However, because aspects of the external morphology of the femur align the fossil with the African great apes, we suggest that the Kikorongo femur may be the first postcranial fossil of the genus Pan. Like the African apes, the Kikorongo specimen lacks both an obturator externus groove and an intertrochanteric line. It has a short femoral neck with a circular cross section, and a narrow and deep superior notch. Using resampling statistics and discriminant function analysis, the Kikorongo femur clustered with the genus Pan, as opposed to Gorilla or Homo. However, if the specimen is from Pan, it would be large for this taxon. Furthermore, features that clearly distinguish the external morphology of Plio-Pleistocene hominin proximal femora from African ape femora, such as the shape of the femoral neck in cross section and femoral neck length, have converged in Holocene humans and African apes. Unfortunately, the internal morphology of the femoral neck of the Kikorongo fossil was not discernable. Although we hypothesize that the Kikorongo femur is from the genus Pan, there is such variability in the proximal femora of modern humans that, although it would be an unusual human, it remains possible that this fossil represents H. sapiens. 相似文献
89.
Diuretic and uricosuric properties have traditionally been attributed to corn silk, stigma/style of Zea mays L. Although the diuretic effect was confirmed, studies of the plant's effects on renal function or solute excretion were lacking. Thus, we studied the effects of corn silk aqueous extract on the urinary excretion of water, Na+, K+, and uric acid. Glomerular and proximal tubular function and Na+ tubular handling were also studied. Conscious, unrestrained adult male rats were housed in individual metabolic cages (IMC) with continuous urine collection for 5 and 3 h, following two protocols. The effects of 25, 50, 200, 350, and 500 mg/kg body wt. corn silk extract on urine volume plus Na+ and K+ excretions were studied in water-loaded conscious rats (2.5 ml/100 g body wt.) in the IMC for 5 h (Protocol 1). Kaliuresis was observed with doses of 350 (100.42 +/- 22.32-120.28 +/- 19.70 microEq/5 h/100 g body wt.; n = 13) and 500 mg/kg body wt. (94.97+/- 29.30-134.32 +/- 39.98 microEq/5h/100 g body wt.; n = 12; p<0.01), and the latter dose resulted in diuresis as well (1.98 +/- 0.44-2.41 +/- 0.41 ml/5 h/100 g body wt.; n = 12; p<0.05). The effects of a 500 mg/kg body wt. dose of corn silk extract on urine volume, Na+, K+ and uric acid excretions, and glomerular and proximal tubular function, were measured respectively by creatinine (Cler) and Li+ (ClLi) clearances and Na+ tubular handling, in water-loaded rats (5 ml/100 g body wt.) in the IMC for 3 h (Protocol 2). Clcr (294.6 +/- 73.2, n = 12, to 241.7 +/- 48.0 microl/ min/100 g body wt.; n = 13; p<0.05) and the Na+ filtered load (41.9 +/- 10.3, n = 12, to 34.3 +/- .8, n = 13, p<0.05) decreased and ClLi and Na+ excretion were unchanged, while K+ excretion (0.1044 +/- 0.0458, n=12, to 0.2289 +/- 0.0583 microEq/min/100 body wt.; n = 13; p<0.001) increased. For Na+ tubular handling, the fractional proximal tubular reabsorption (91.5 +/- 3.5, n = 12, to 87.5 +/- 3.4%; n = 13; p<0.01) decreased, and both fractional distal reabsorptions--I and II--increased (96.5 +/- 1.5, n = 12, to 97.8 +/- 0.9%; n = 13; p<0.01; and 8.2 +/- 3.5, n = 12, to 12.2 +/- 3.4%, n = 13, p<0.01, respectively). To summarize, in water-loaded conscious rats (2.5 ml/100 body wt.), corn silk aqueous extract is diuretic at a dose of 500 mg/kg body wt. and kaliuretic at doses of 350 and 500 mg/kg body wt. In water-loaded conscious rats (5.0 ml/100 g body wt.), corn silk aqueous extract is kaliuretic at a dose of 500 mg/kg body wt., but glomerular filtration and filtered load decrease without affecting proximal tubular function, Na+, or uric acid excretion. 相似文献
90.
目的:探究强骨胶囊对老年股骨头近段骨折延迟愈合患者血清骨形态发生蛋白-2(BMP-2)及胰岛素生长因子-1(IGF-1)水平的影响。方法:选择我院收治的股骨近端骨折延迟愈合的老年患者41例,随机分为实验组及对照组。对照组19例予钙片;实验组22例予强骨胶囊。对比两组的临床疗效及治疗前后血清BMP-2及IGF-1水平的改变。结果:实验组总有效率(95.5%)高于对照组(78.9%),差异具备统计学意义(P0.05)。两组血清BMP-2及IGF-1水平均较治疗前显著升高(P0.05),且实验组血清BMP-2和IGF-1水平较对照组高(P0.05)。治疗后,两组血浆粘度均下降、骨密度值(BMD)均升高(P0.05);与对照组相较,实验组血浆粘度降低、BMD较高(P0.05)。结论:强骨胶囊能够有效改善老年股骨头近段骨折延迟愈合,促进骨折断端的愈合,推测其机制与增加患者血清BMP-2及IGF-1水平有关。 相似文献