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11.

Objective:

To evaluate the influence of elite-level alpine skiing on athletes’ skeleton.

Methods:

Thirteen professional alpine skiers (9 males and 4 females with mean age of 22.6 years) and their age- and height matched control subjects were measured with dual energy X-ray absorptiometry (total body, lumbar spine, proximal femur, forearm) and quantitative ultrasound (hand).

Results:

After adjusting for sex, age, weight and height, between-group differences were 15% (p=0.012) for the lumbar spine, 14% (p=0.022) for the femoral neck, 10% (p=0.051) for the total hip, and 11% (p=0.001) for the total body favoring the alpine skiers. However, after controlling for total body lean mass (~muscle mass), the group-differences lost their statistical significance, the borderline 10% difference (p=0.051) in femoral neck BMD excluded.

Conclusion:

Factors contributing to the alpine skiers’ higher BMD may not only include the greater muscle mass (~stronger muscles) of these athletes but also a large number of impacts and possibly other high-frequency features in external loading generated by the high-speed skiing performance.  相似文献   
12.
The use of ultrasound for the control of algae and in particular for Microcystis aeruginosa has been investigated. The results indicate that sonication may provide a more environmentally friendly and more effective method for the control of cyanobacteria blooms than conventional treatments.Algae blooms occur frequently and globally in water bodies and are a major concern in terms of their effects on other species such as plants, fish and other microorganisms together with the potential danger to human health from cyanobacterial toxins that are carcinogenic. In addition to removing the algae itself ultrasound can also degrade such toxins. A range of ultrasonic conditions (in terms of frequency and intensity) have been studied under laboratory conditions together with a small number of pilot (field) studies that confirm the potential for ultrasonic treatment of algae on a large scale.  相似文献   
13.
Sicilo-Sarde is a local breed from northern Tunisia resulting from crossing Sarda and Comisana dairy sheep and is traditionally used for cheese production after lamb weaning. A sample of 52 adult Sicilo-Sarde lactating ewes was used for studying their udder morphological traits and milk yield potential during weeks 4-8 (milking-suckling period) and 10 (milking period) of lactation. Daily milk yield was estimated on a daily basis by using the double oxytocin injection method 4 h after machine-milking at d 30 and 45. Udder and teat morphology were also measured at d 45 of lactation. Cisternal area (by ultrasonography) and udder compartments (cisternal and alveolar milk) were evaluated 8 h after milking by using atosiban and oxytocin on d 72 of lactation. Milk yield averaged 0.56 ± 0.10 L/d and ewes had small (volume, 496 ± 28 mL) and healthy udders (CMT, <1), with medium sized teats (length, 18.5 ± 4.9 mm; diameter, 10.0 ± 2.0 mm) attached at 45 ± 10°. A drop in milk production (49%) was found in the transition from suckling (day 30) to milking (week 10). Udder cisterns were multilocular and small sized (half udder area, 11.6 ± 4.5 cm2), although cisternal milk accounted for 54% of the total milk in the udder. Correlation between cisternal milk and cisternal area was moderate (R2 = 0.48; P < 0.05). Lag time and total milking time were 1.9 ± 0.1 and 31 ± 5 s, respectively. In conclusion, the Sicilo-Sarde ewes evaluated showed medium sized cisterns and teats which were morphologically adequate for machine milking, although milk production needs to be improved.  相似文献   
14.
目的:评价超声在诊断妊娠合并急腹症中的临床应用价值。方法:回顾分析686例妊娠合并急腹症患者的临床资料,总结妊娠合并急腹症超声图像特征。结果:超声诊断符合率为:异位妊娠87.2%(184/211),急性阑尾炎84.2%(32/39),卵巢囊肿蒂扭转90.0%(27/30),急性胰腺炎66.7%(6/9),不全流产及难免流产、子宫肌瘤扭转、子宫肌瘤红色变性、胎盘早剥、泌尿系结石、急性胆囊炎和胆结石、急性胃肠炎、急性肠梗阻的诊断率为100%(43/43)。结论:超声可以作为妊娠合并急腹症首选的检查手段,为临床早期诊断及治疗提供可靠依据。  相似文献   
15.
陈风华  钱建林  宣丽敏  周卫华  张燕 《生物磁学》2011,(15):2891-2892,2871
目的:探讨超声诊断胰腺脂肪浸润与血脂、脂肪肝的关系。方法:回顾性分析63例胰腺脂肪浸润者与148例同期检查无胰腺脂肪浸润者的病历资料,研究胰腺脂肪浸润的超声特点以及与脂肪肝、血脂浓度、年龄、血压等的关系。结果:胰腺脂肪浸润超声显示为胰腺饱满,边缘模糊,回声增强且明显强于肝脏,与正常胰腺超声影像容易鉴别。胰腺脂肪浸润组血浆甘油三酯浓度2.17±1.22mmol/L,比非浸润组的1.35±1.06mmol/L明显高(P〈0.05),胰腺脂肪浸润组患者100%(63/63)合并脂肪肝明显高于非浸润组的20.95%(31/148)(P〈0.05)。二组在胆固醇浓度、高血压发病率及年龄方面无显著差异(P〉0.05)。结论:胰腺脂肪浸润与脂肪肝、血浆甘油三酯浓度有着一定的相关性,超声诊断胰腺脂肪浸润对于提示其他相关疾病与异常的存在具有重要临床参考价值。  相似文献   
16.
This work studied the effects of ultrasound-assisted liquid-state fermentation on the content of peptides and bioactivity of fermented soybean meal (FSBM) with Bacillus subtilis. Based on the optimization of basic ultrasonic parameters, effects of the main parameters including power density, incubation temperature and ultrasonic time on in vitro ACE inhibitory activity, peptides content and biomass of B. subtilis were investigated via Box-Behnken experimental design. Three mathematical models were determined to show the effects of each variable and their combinatorial interactions on dependent variables. A set of preferred condition was determined to be at power density of 0.08 W/mL for 1 h with an initial incubation temperature of 36.7 °C, according to the desirability function analyses. Under these conditions, the experimental values of in vitro ACE inhibitory activity, peptides content and biomass increased by 26.4%, 36.2% and 55.0% compared to those of the control, respectively, accompanied by the improvement of the peptides yield, purity and conversion rate in varying degrees. Additionally, FSBM resulted in a significant decrease of systolic blood pressure by 20.7 ± 1.8 mmHg in spontaneously hypertensive rats at 3 h. These results suggest that ultrasonication is an efficient solution for enhancing fermentation to produce bioactive components from agroindustrial by-products.  相似文献   
17.
目的:探讨超微血流成像术用于肾移植患者术后评估的临床价值。方法:选取我院2019年2月-2019年8月收治的60例肾移植患者的临床资料,根据术后恢复情况分为A、B、C三组,A组(27例,术后肾功能恢复良好)、B组(20例,术后发生过敏肾功能异常病变但治疗后肾功恢复正常)、C组(13例,术后血肌酐水平持续增高肾功能异常者),三组均采用超微血管流成像术检测血管指数,比较不同组患者的血管指数并分析其与血肌酐水平的关系。结果:三组患者的肾移植长径、前后径、左右径、皮质厚度、叶间动脉阻力指数比较无显著差异(P0.05)。C组患者的肾皮质血管指数(23.34±6.03%)明显低于A组(33.23±3.45%)、B组(31.23±4.23%)(P0.05)。肾功能异常患者肾皮质的血管指数较低,且随着血肌酐水平的升高而下降,两者呈显著负相关(r=-0.23,P0.05)。结论:超声微血流成像术用于肾移植患者术后评估可较好地反映肾皮质血供及术后肾功能的变化。  相似文献   
18.
高强度聚焦超声换能器温度场的数值仿真   总被引:2,自引:0,他引:2  
相控阵高强度聚焦超声换能器可以通过换能器上不同阵元发射超声波的时间不同来实现变焦、多焦点。该论文应用Westervelt方程的近似式,结合Pennes热传导方程,以人体乳房为例,FDTD(finite difference time domain)仿真对比研究平面阵列相控聚焦换能器与曲面阵列相控聚焦换能器形成温度场的特性,同时数值仿真研究不同占空比的正弦激励函数、不同治疗频率、声强对曲面阵列相控聚焦换能器超声温度场的影响。研究结果表明曲面阵列相控聚焦换能器能有效地减少皮肤处的温升,对皮肤的伤害较小;对于曲面阵列相控聚焦换能器,不同占空比的正弦激励函数形成的可治疗区域(60℃以上)大小差别不大,但最高温度不同;随着频率升高,形成的可治疗区域体积减小;随着输入声强的增大,可治疗区域变大,但焦距不变。  相似文献   
19.
The aim of the study was to compare transrectal ultrasound with progesterone (P4) and pregnancy-associated glycoproteins (PAGs) as pregnancy detection methods for semidomesticated reindeer (Rangifer tarandus tarandus) in field conditions. Female reindeer (n = 195) were scanned transrectally by a 7.5-MHz linear array transducer, and blood was sampled either in December 2005 (n = 33), December 2006 (n = 92), or January 2007 (n = 70) during early or mid gestation. Plasma levels of P4 and PAGs were assessed by radioimmunoassay (RIA). Based on calving records, the sensitivity, specificity, predictive values, and the overall accuracy of the three tests were calculated. The overall calving rate calculated from the calving records was 86.2%. The overall accuracy of transrectal ultrasound was 99.5%. The sensitivity and specificity of transrectal ultrasound were 99.4% and 100%, respectively. In the plasma P4 test, the threshold level of 5.0 nmol/L gave the highest overall accuracy (94.9%). The sensitivity of the P4 test decreased from 96.4% to 81.5%, when the threshold level increased from 5.0 nmol/L to 8.0 nmol/L, while the specificity remained at 85.2% over the range of these cutoff values. The overall accuracy of the plasma PAG test decreased from 96.4% to 64.1% when the plasma PAG threshold level increased from 0.5 ng/mL to 3.5 ng/mL, whereas sensitivity decreased from 99.4% to 58.3%. Specificity increased from 77.8% to 100% when the plasma PAG threshold level reached 3.0 ng/mL. Transrectal ultrasound showed higher diagnostic values than those of plasma P4-RIA and PAG-RIA in diagnosing pregnancy of reindeer, with the advantage that diagnoses can be made in real time in field conditions.  相似文献   
20.
超声对胃蛋白酶,胰蛋白酶,过氧化氢酶作用的研究   总被引:3,自引:0,他引:3  
以胃蛋白酶,胰蛋白酶,过氧化氢酶溶液在超声处理下的酶活变化为指标研究超声对蛋白质作用的机理和影响因素。结果表明超声对蛋白质的破坏程度随着功率的升高或处理时间的延长而增加;三种酶在超声作用下酶活变化形式和程度各不同;浓度是影响超声对酶作用效果的一个重要因素,可通过调整酶溶液浓度来减少酶所受到的破坏程度。自由基清除剂甘露醇和非离子表面活性剂吐温-80可以对酶活在超声作用下起到一定的保护作用,说明自由基和超声空穴是超声破坏酶结构的重要机理,研究结果同时表明对于不同的酶,超声的破坏作用可能有不同的发挥主导作用机理。  相似文献   
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