Efeito da intensidade do exercício físico no gasto energético com atividades físicas em meninos com excesso de peso.

Estudos epidemiológicos têm mostrado rápido aumento na prevalência de sobrepeso e obesidade, tanto na população adulta quanto em crianças e adolescentes, sendo o exercício físico considerado uma importante estratégia tanto na prevenção quanto no tratamento do ganho de peso. Apesar disso, estudos que avaliam os efeitos isolados do exercício físico no controle ponderal têm apresentado resultados conflitantes. Esses achados podem ser explicados por um possível efeito compensatório provocado pela sessão de exercício nas atividades físicas realizadas em períodos subsequentes. Portanto, o objetivo deste estudo é avaliar o efeito de diferentes intensidades do exercício físico no gasto energético com atividades físicas em adolescentes com excesso de peso. O desenho do estudo foi experimental do tipo crossover com realização de três sessões (controle, exercício moderado e exercício vigoroso). Vinte e quatro adolescentes de 11 a 13 anos, estudantes da rede municipal de ensino de Niterói-RJ, do sexo masculino e com excesso de peso concordaram em participar do estudo. O gasto energético com atividades físicas foi avaliado por acelerômetros triaxiais colocados durante as sessões experimentais e retirado após seis dias. Os dados referentes ao gasto energético associado às atividades físicas foram avaliados na 1 hora de utilização do acelerômetro e durante os seis dias de acompanhamento. Além disso, os valores também foram tratados de forma cumulativa, tendo sido calculado o gasto energético total de 24, 48, 72, 96, 120 e 144 horas. Análise de variância foi utilizada para avaliar as possíveis diferenças entre o gasto energético na primeira hora de registro entre os três grupos seguida do teste post hoc de Scheffé. A comparação das variações das médias de gasto energético (por dia e acumuladas) foi realizada por meio de modelos lineares mistos. A comparação do gasto energético durante a 1 hora de registro demonstrou diferença significativa entre todos três grupos, com médias de 82, 286 e 343 kcal para os grupos controle, moderado e intenso, respectivamente (p<0.001). O mesmo padrão de diferença para o gasto energético entre os grupos se manteve ao final de 24 horas (704 vs 970 vs 1056 kcal, p<0.001) e no gasto energético acumulado durante os seis dias de acompanhamento (5102 vs 5193 vs 5271 kcal, p<0.001). A análise do gasto energético por dia demonstrou uma redução do gasto energético dos grupos moderado e vigoroso a partir do segundo dia e que se manteve até o sexto dia de acompanhamento. Desse modo, pode-se concluir que uma única sessão de exercício físico aeróbio parece modificar o comportamento das atividades físicas espontâneas realizadas ao longo de 6 dias em adolescentes com excesso de peso. Entretanto, apesar do efeito compensatório observado, o gasto energético acumulado durante os seis dias para os grupos que realizaram as sessões de exercícios foi superior ao da sessão controle, tendo o grupo vigoroso apresentado o maior dispêndio acumulado para o período de acompanhamento. Futuros estudos são necessários de modo a investigar a compensação do gasto energético em obesos e não obesos e o efeito de um número maior de sessões de treinamento.

Microvortex generators applied to flowfield containing a normal shock wave and diffuser

The flow through a terminating shock wave and the subsequent subsonic diffuser typically found in supersonic inlets has been simulated using a small-scale wind tunnel. Experiments have been conducted at an inflow Mach number of 1.4 using a dual-channel working section to produce a steady near-normal shock wave. The setup was designed so that the location of the shock wave could be varied relative to the diffuser. As the near-normal shock wave was moved downstream and into the diffuser, an increasingly distorted, three-dimensional, and separated flow was observed. Compared with the interaction of a normal shock wave in a constant area duct, the addition of the diffuser resulted in more prominent corner interactions. Microvortex generators were added to determine their potential for removing flow separation. Although these devices were found to reduce the extent of separation, they significantly increased three-dimensionality and even led to a large degree of flow asymmetry in some configurations. Copyright © 2011 by Neil Titchener and Holger Babinsky.

Fabrication and testing of a high resolution extensometer based on resonant MEMS strain sensors

A novel type of linear extensometer with exceptionally high resolution of 4 nm based on MEMS resonant strain sensors bonded on steel and operating in a vacuum package is presented. The tool is implemented by means of a steel thin bar that can be pre-stressed in tension within two fixing anchors. The extension of the bar is detected by using two vacuum-packaged resonant MEMS double- ended tuning fork (DETF) sensors bonded on the bar with epoxy glue, one of which is utilized for temperature compensation. Both sensors are driven by a closed loop self-oscillating transresistance amplifier feedback scheme implemented on a PCB (Printed Circuit Board). On the same board, a microcontroller-based frequency measurement circuit is also implemented, which is able to count the square wave fronts of the MEMS oscillator output with a resolution of 20 nsec. The system provides a frequency noise of 0.2 Hz corresponding to an extension resolution of 4 nm for the extensometer. Nearly perfect temperature compensation of the frequency output is achieved in the temperature range 20-35 C using the reference sensor. © 2011 IEEE.

一个先天性小眼球家系致病基因的排除性定位

先天性小眼球是一种先天发育异常性眼科疾病.通过基因扫描和连锁分析对一个6代常染色体显性遗传先天性小眼球中国家系的疾病相关基因进行研究.根据已报道的与小眼球相关的5个基因座位(MITF,SOX2,PAX6,MCOP和NNO2),在3,11,14和15号染色体上选取了14个微卫星标记,以荧光标记引物的聚合酶链反应(PCR)扩增目的片段,用ABI 377 DNA遗传分析仪对该家系成员进行基因扫描和基因分型,并采用Linkage软件包对基因分型结果进行连锁分析.结果显示,该家系致病基因与这些已报道的座位均不连锁,即该家系致病基因不是已报道的座位,可能是一个尚未报道的对眼球发育至关重要的新基因座位.

Triterpenoids from Schisandra rubriflora

Investigation of an organic extract of Schisandra rubriflora led to the isolation of three new highly oxygenated nortriterpenoids, named rubriflorins A-C (1-3), together with six related known compounds (4-9). Their structures were elucidated by spectrosc

Impacts of fish sanctuaries on the production and diversity of plankton on beels of haor region in Bangladesh

The experiment was carried out to study the impacts of fish sanctuaries on the production and diversity of plankton in beels of haor region at Mithamain Upazila of Kishoreganj district in Bangladesh during July 2004 to June 2005. A total of 75 (60 phyto and 15 zooplankton) and 74 (59 phyto and 15 zooplankton) genera of plankton were recorded in T-1 and T-2 (with sanctuary) respectively while only 50 (39 phyto and 11 zooplankton) genera were obtained in T-3 (control). Chlorophyceae and Copepoda were the most dominant group of phytoplankton and zooplankton respectively in all the treatments. The total phytoplankton numbers were found to range from 5472 to 35,833 cells/l and 5250 to 40,472 cells/l and total zooplankton from 667 to 1722 cells/l and 611 to 1667 cells/l in T-1 and T-2 respectively in sanctuary sites whereas the ranges of phytoplankton and zooplankton in the control site were 1778 to 29,333 cells/l and 56 to 1056 cells/l respectively. The maximum phytoplankton and zooplankton were recorded during winter season in all the treatments. The ranges of total plankton were 6194 to 37,500 cells/l, 6028 to 41,806 cells/l and 1889 to 29,444 cells/l in T-1, T-2 and T-3 respectively. The phytoplankton, zooplankton and total plankton recorded in treatments with sanctuary were significantly higher (p<0.5) than the treatment without sanctuary (control) indicating positive impacts of sanctuaries on the production of plankton. Between two treatments of fish sanctuaries the total plankton populations were comparatively higher in T-2 than T-1.

烧结厂烟尘和静电除尘器灰尘中二噁英的分布特征

研究了烧结厂烟道烟尘和静电除尘器灰尘中二噁英的浓度和分布特征.结果显示,烧结台车机头烟道烟尘和机尾烟道烟尘中二噁英的总含量分别为867.49±215.41和170.35±51.12pg.Nm-3,毒性当量分别36.53±4.47和9.13±2.40pgWHO-TEQ.Nm-3;机头静电除尘器灰尘和机尾静电除尘器灰尘的总含量分别为2423.59±100.01和157.29±36.83pg.g-1dw,毒性当量分别71.67±0.62和7.50±1.08pgWHO-TEQ.g-1dw.烧结中二噁英的分布以PC

A broadband external cavity tunable InAs/GaAs quantum dot laser by utilizing only the ground state emission

A broadband external cavity tunable laser is realized by using a broad-emitting spectral InAs/GaAs quantum dot (QD) gain device. A tuning range of 69 nm with a central wavelength of 1056 nm, is achieved at a bias of 1.25 kA/cm(2) only by utilizing the light emission from the ground state of QDs. This large tunable range only covers the QD ground-state emission and is related to the inhomogeneous size distribution of QDs. No excited state contributes to the tuning bandwidth. The application of the QD gain device to the external cavity tunable laser shows its immense potential in broadening the tuning bandwidth. By the external cavity feedback, the threshold current density can be reduced remarkably compared with the free-running QD gain device.

基于AJAX的B/S电子表单填写模式研究

电子表单系统是电子政务建设中重要的一个环节。论述了电子表单系统独立的必要性,调研了几种现有电子表单系统的优缺点,并在此基础上提出一种新型电子表单的框架实现。该电子表单系统提供了一种新型B/S在线填写模式,模式基于AJAX,只需要能支持AJAX的浏览器,不需安装任何附加控件,具有方便快捷的特点。利用AJAX进行数据传输,能有效地节省带宽,节省用户等待时间,并能给用户进行表单填写提供一个友好灵活的操作界面。

基于DEM的黄河中游植被恢复对年均径流量影响的估计

植被恢复及其对年均径流量影响的空间格局对黄土高原生态环境建设及水资源管理具有重要指导作用。在分析植被适宜性分布规律的基础上,基于黄河中游河口-龙门区间100m地形高程模型(DEM)和专家经验进行了区域植被适宜性制图,并基于参数率定后的多年平均蒸散量计算公式和水平衡模型,估算了不同植树造林情景下年均径流量的变化。结果表明,河龙区间符合植被带分布规律的适宜区植树面积为6.6×103km2,次适宜区植树面积为4.8×103km2,分别占研究区总面积的5.8%和4.3%。土地覆被现状条件下区域产水约为33.8mm(38.07×108m3)。适宜区植树后,区域产水减少量约为1.9mm(2.12×108m3),减少5.6%。适宜区和次适宜区均植树后,区域产水减少量约为3.1mm(3.49×108m3),减少9.2%。空间分布格局表明,区域局部减水最大达到48mm。受气候条件影响,东南部高降雨量地区的流域适宜植树面积达45.1%,相应减水比例达36.0%。西北部低降雨量地区的流域植树面积约为0.7%,相应的减水比例为0.4%。