Ultrasound-Based Fetal Tracking Technology During Labor: Is It the Next Best Thing?

In this column, the author reprises a recent selection from the Lamaze International research blog, Science & Sensibility. With the introduction of a new technology intended to acutely track fetal station and position during labor through birth, questions are being raised about the necessity—and possible danger—of this technology and its potential impact on normal birth.     

金纳米粒子的制备与表征

以4.5 G PAMAM（4.5代聚酰胺-胺型）树状大分子为保护剂,利用微波法还原HAuCl4溶液制备金纳米粒子。考察了在同一照射条件下,4.5 G PAMAM与HAuCl4不同物质的量比对金纳米粒子大小及形状的影响。利用紫外可见分光光度计、透射电子显微镜以及X射线衍射分析对其进行了表征。结果表明,照射时间相同时,以30 s为例,当4.5 G PAMAM与HAuCl4物质的量比为5时,得到的金纳米粒子最小;随着4.5 G PAMAM与HAuCl4物质的量比值的减小,金纳米粒子变大,且发生了不同程度的聚集。     

Morphological and biochemical responses of Oryza sativa L. (cultivar MR219) to ion beam irradiation

Objective

Heavy ion beam, which has emerged as a new mutagen in the mutation breeding of crops and ornamental plants, is expected to result in the induction of novel mutations. This study investigates the morphological and biochemical responses of Oryza sativa toward different doses of carbon ion beam irradiation.

Methods

In this study, the dry seeds of O. sativa were irradiated at 0, 20, 40, 60, 80, 100, and 120 Gy, followed by in-vitro germination under controlled conditions. Morphological and biochemical studies were conducted to investigate the morphological and physiological responses of O. sativa towards ion beam irradiation.

Results

The study demonstrated that low doses (10 Gy) of ion beam have a stimulating effect on the height, root length, and fresh weight of the plantlets but not on the number of leaves. Meanwhile, doses higher than 10 Gy caused reductions in all the morphological parameters studied as compared to the control samples. The highest total soluble protein content [(2.11±0.47) mg/g FW] was observed in plantlets irradiated at 20 Gy. All irradiated plantlets were found to have 0.85% to 58.32% higher specific activity of peroxidase as compared to the control samples. The present study also revealed that low doses of ion beam (10 and 20 Gy) had negligible effect on the total chlorophyll content of O. sativa plantlets while 40 Gy had a stimulating effect on the chlorophyll content. Plantlets irradiated between 40 to 120 Gy were shown to be 0.38% to 9.98% higher in total soluble nitrogen content which, however, was not significantly different from the control samples.

Conclusions

Carbon ion beam irradiation administered at low to moderate doses of 10 to 40 Gy may induce O. sativa mutants with superior characteristics.     

Ultrasonic phased array technology for the non-destructive testing of marble sculptures

The medical ultrasonic phased array technology was modified for the non-destructive testing of marble sculptures and the feasibility of the approach was evaluated. For this purpose, 1?MHz, 64-channel phased array electronic and phased array transducers were developed. The specifications of the electronics and the transducers are presented and discussed. Ultrasound images of inner structures of a marble sculpture are presented. The problem of the acoustic matching layers for different states of deterioration is discussed and the developments in view of a suitable matching layer solution are presented. This matching layer is combined with a new coupling technique that protects the marble surface. The results of experiments on ultrasound phantoms and on a marble sculpture are presented.     

高强度聚焦超声手术平台的Bezier曲线定位规划

提出了一种定位区域球方法来表示高强度聚焦超声手术平台在定位运动时肿瘤在其工作空间中的位置和姿态. 针对该简化肿瘤模型, 使用最近邻近查询方法确定了治疗头和超声焦点在定位到肿瘤目标过程中必须经过的中间位姿和目标位姿. 根据确定的位姿, 把组合Bezier曲线的连续条件和SO(3)的De Casteljau算法结合, 构造出了一条在衔接位姿C2连续的组合Bezier曲线路径用于定位, 并且根据一例肝脏肿瘤病例对各种连续路径作了详细分析.     

微波辐射处理生活废水方法研究

在以颗粒活性炭为催化剂采用微波辐射技术处理生活废水过程中,活性炭用量、微波辐射功率和微波辐射时间等因素对处理效果有显著的影响.研究表明,2g活性炭处理50mL浓度为50mg/L的溶液时,在微波炉功率为800W,反应时间为6.5min条件下处理效果最佳.     

The effect of low back pain on trunk muscle size/function and hip strength in elite football (soccer) players

ABSTRACT

Low back pain (LBP) is a common problem in football (soccer) players. The effect of LBP on the trunk and hip muscles in this group is unknown. The relationship between LBP and trunk muscle size and function in football players across the preseason was examined. A secondary aim was to assess hip muscle strength. Twenty-five elite soccer players participated in the study, with assessments conducted on 23 players at both the start and end of the preseason. LBP was assessed with questionnaires and ultrasound imaging was used to assess size and function of trunk muscles at the start and end of preseason. Dynamometry was used to assess hip muscle strength at the start of the preseason. At the start of the preseason, 28% of players reported the presence of LBP and this was associated with reduced size of the multifidus, increased contraction of the transversus abdominis and multifidus muscles. LBP decreased across the preseason, and size of the multifidus muscle improved over the preseason. Ability to contract the abdominal and multifidus muscles did not alter across the preseason. Asymmetry in hip adductor and abductor muscle strength was found between players with and without LBP. Identifying modifiable factors in players with LBP may allow development of more targeted preseason rehabilitation programmes.     

紫外光照下辣根过氧化物酶酶活变化及机制

实验发现不同波长光对辣根过氧化物酶(HRP)酶活的钝化程度不同,我们采用紫外、荧光及圆二色(CD)等方法对光还原导致酶活变化及其机制进行研究。结果显示,280 nm单色光照射HRP溶液60 min后,酶活降为72.81%,403 nm单色光照射HRP溶液同样时间后,酶活仅为未光照时的56.34%。紫外光谱证实光照使辣根过氧化物酶中的铁被还原,导致HRP钝化。同步荧光和CD光谱表明光还原后蛋白内色氨酸残基微环境的极性增加,403 nm单色光照射使血红素构象发生改变,光照时间内蛋白未变性。根据以上数据可知,两种单色光诱导HRP还原钝化机理不同:280 nm单色光激活色氨酸丢失电子,血红素中铁得到电子被还原;403 nm单色光则激发卟啉环分子内电子转移致使铁被还原。     

一个用于体外评价超声造影剂显影效果的系统（英文）

构建并评价了一个用于体外研究超声造影剂显影效果的系统,该系统包括一套数字化B型超声诊断仪Belson3000A、仿组织超声体模和用于图像量化分析的软件.制备了具有不同反射强度的仿组织超声体模,通过对这些体模材料超声成像,研究了B超系统的线性范围、参数设置和系统的重复性等.超声成像设置为：输出声功率为4.8 ～12.3mW,探头的中心频率为3.5MHz,总增益为50dB.利用该系统,对自制备的表面活性剂微气泡和一种商用造影剂进行了显影成像.结果表明超声图像的灰度值随声功率的增加而增大,强反射特性的超声体模成像时,这种增加趋势更明显.该系统适合用于体外评价超声造影剂的显影效果,为体外表征超声微气泡造影剂的显影能力提供了一种简单、有效、实时的评价方法.     

紫外照射对大肠埃希氏菌质粒DNA影响的研究

本研究对大肠杆菌进行紫外照射诱变后,获得了通过其内部的SOS修复系统产生的突变菌株,采用异丙醇沉淀法对各组菌种进行质粒DNA提取.通过测定各组OD值,经过比较与分析得出了经紫外处理10min后的大肠杆菌质粒DNA浓度最高,为215ug/ml,其次为正常组的190ug/ml.经紫外照射30min后的大肠杆菌质粒DNA浓度最低,仅为65ug/ml.紫外处理时间与质粒DNA浓度整体呈现下降趋势.初步推测是由于大肠杆菌SOS修复系统的RecA蛋白促进了不完全同源的DNA序列之间的重组,产生大量的错配碱基,从而引起突变,进而影响到其质粒DNA的浓度.