Water-dispersed bone morphogenetic protein nanospheres prepared by co-precipitation method

INTRODUCTION Bone morphogenetic proteins (BMPs) are agroup of proteins that can induce new bone forma-tion at orthotopical and heterotopical sites in ex-perimental animals (Urist et al., 1983; Groeneveldand Burger, 2000). Their biological activity hasstimulated interest in its clinical use for bone repair.In clinical use, BMPs are undergoing evaluationincluding system administration, gene transfer andlocal matrix delivery vehicle implantation (Kirker-Head, 2000; King et al., 199…     

Effect of interrupted endogenous BMP/Smad signaling on growth and steroidogenesis of porcine granulosa cells

Bone morphogenetic proteins (BMPs) play a critical role in the growth and steroidogenesis of granulosa cells (GCs). BMP signals act through membrane-bound heteromeric serine/threonine kinase receptors. Upon ligand binding, BMPs activate intracellular Smad proteins and regulate growth and apoptosis in various cell types. The objective of this study was to demonstrate the effects of BMP/Smad signal on growth and steroidogenesis of porcine GCs. A strategy of RNA interference (RNAi)-mediated ‘gene silencing’ of Smad4, a core molecule mediating the intracellular BMP/Smad signal transduction pathways, was used to interrupt endogenous BMP/Smad signaling. Results indicate that Smad4-small interfering RNA (siRNA) caused specific inhibition of Smad4 mRNA and protein expression after transfection. Interrupted endogenous BMP/Smad signaling significantly inhibited growth, and induced apoptosis of porcine GCs, while decreasing estradiol production. In addition, interrupted BMP/Smad signaling significantly (P<0.05) changed the expression of Cyclin D2, CDK4, Bcl-2, and Cyp19a1. These findings provide new insights into how BMP/Smad signaling regulates the growth and steroidogenesis of porcine GCs.     

Low cost demonstration experiment Lorentz force: Change in path of charged particles in magnetic field

The path of charged particles is affected when they enter a magnetic field. This change of path largely depends on the angle between the applied magnetic field and the direction of motion of the charged particle (and its velocity) entering the magnetic field. This is demonstrated by means of a simple, low-cost experiment. A high voltage is used to ionize the air between a spark gap. The flow of charged particles between the spark gap is altered by applying a magnetic field from a rare earth permanent magnet having surface magnetic field induction of 0.12 T.     

辐射带电粒子在电磁场中的运动方程

带电粒子和电磁场相互作用时,带电粒子激发电磁场的同时电磁场又对粒子有反作用,要求解带电粒子与电磁场系统的动力学问题,必须把两者之间的相互作用同时考虑,才能得出完整的粒子运动方程以及电磁场.在经典电动力学的基础上,讨论了辐射阻尼力影响下非相对论性带电粒子在复合场中的运动,导出了辐射带电粒子的完整地运动方程,模拟了带电粒子对外辐射的电磁能量.     

带电粒子自身电磁场对粒子本身的反作用

在经典电动力学的基础上,讨论了辐射阻尼力影响下非相对论性带电粒子在复合场中的运动,导出了辐射带电粒子的完整运动方程.     

联合絮凝模型及其试验研究

本文通过实验,证明了作者所提出的联合絮凝模型的正确性,并发现在使用高分 子絮凝剂时,絮凝剂的电性对絮团尺寸的影响并不重要.     

带电粒子在电磁场中运动的分析

本文通过对不同电磁场中带电粒子受力的分析,推导了不同情况下带电粒子的运动方程以及运动轨迹,说明了带电粒子在各种电磁场中运动时由于电磁场在均匀性及相关差异方面的不同,带电粒子的运动方程存在着差异,从而有其运动面的不同,最后从几种情况中总结出带电粒子在电磁场中运动时总的运动规则和特点。     

均匀电磁场中带电粒子的运动学特性

通过对不同电磁场环境中的带电粒子受力情况研究带电粒子的运动规律.带电粒子只受电场或只受磁场作用时,其运动轨迹分别是抛物线或螺旋线.当带电粒子受电磁场作用时(带电粒子初速度、电场与磁场两两相互垂直或磁场垂直于初速度与电场构成的平面且初速度与电场成任意角度),得出带电粒子的运动方程.     

带电粒子在均匀电磁场中运动的普遍规律

本文通过适当选择坐标系，导出了非相对论情况下带电粒子在均匀电磁场中运动的普遍规律。由此推出的某些特殊情况下带电粒子的运动规律与有关文献给出的结果是一致的。     

Expression of bone morphogenetic protein 2, 4, and related components of the BMP signaling pathway in the mouse uterus during the estrous cycle

The objective was to investigate the expression of bone morphogenetic protein (BMP) family members in the mouse uterus during the estrous cycle by real-time polymerase chain reaction (PCR) and immunohistochemistry. Uterine samples from Swiss ICR mice were collected and dissected free of surrounding tissue. One uterine horn was snap frozen in liquid nitrogen immediately after collection and stored at −80 °C for RNA extraction, and the other was fixed in 40 mg/ml paraformaldehyde at room temperature for immunolocalization of BMP2 protein. Real-time PCR analysis showed that the expression level of Bmp2 was significantly higher at proestrus than at estrus and metestrus (P<0.05). The relative abundance of Bmp4 exhibited significant fluctuations, but there were no statistically significant differences between the expression levels of Bmp2 and Bmp4 (P>0.05). The expression levels of Bmpr1a and Bmpr2 remained unchanged during estrous cycles. However, the level of Bmpr1b mRNA decreased significantly at estrus (P<0.05), increasing subsequently at metestrus. Furthermore, the level of Bmpr1b mRNA was significantly lower than those of Bmpr1a and Bmpr2 mRNA at the corresponding stages (P<0.05). All three receptor-regulated Smads (R-Smads) detected were differentially expressed in the mouse uterus and the expression levels of Smad1 and Smad5 were significantly higher than that of Smad8 (P<0.05). In addition, the expression level of Smad4 did not change substantially throughout the estrous cycle. Immunohistochemical experiments revealed that BMP2 protein was differentially expressed and localized mainly in the uterine luminal and glandular epithelial cells throughout the estrous cycle. In conclusion, our results provide information about the variation in the mRNA levels of Bmp2 and Bmp4 and related components of the BMP signaling pathway. The data provide quantitative and useful information about the roles of endometrial BMP proposed and demonstrated by others, such as the degradation and remodeling of the endometrium.     

用量子理论分析均匀磁场中带电粒子的运动

该文采用量子理论分析均匀的外磁场中带电粒子的运动情况,及相应概率流密度的计算.对于存在于原子系统的电子,由于磁矩的存在与磁场相互作用,能级发生分裂.自由运动的带电粒子,当处于均匀磁场中时,通过多种情况分析发现在垂直磁场矢势的平面内粒子做自由运动,在一固定点出现了粒子流恒定的现象,而平行矢势方向做简谐振动,粒子流恒为零.     

两匀速运动带电粒子的相互作用

利用洛伦兹变换，导出带电粒子的电磁场；根据运动带电粒子的电磁场，推出匀速带电粒子的相互作用。     

霍尔效应的量子力学定性讨论

考虑到带电粒子在电磁场中的运动,利用量子力学原理定性地解释了霍尔效应.讨论了Lorentz 力和电力平衡下量子行为.通过推导沿着外场方向的平均速率,推演了宏观霍尔系数.     

骨形态发生蛋白-2在大肠杆菌中的表达与纯化

骨形态发生蛋白-2（bone morphogenetic protein,BMP-2）具有多种生物活性,有潜在的药用价值.为探索利用基因工程技术重组BMP-2并在大肠杆菌表达系统表达的可行性.在大肠杆菌中重组和筛选BMp-2基因,SDS-PAGE电泳分析,显示外源蛋白带在相对分子量约12kD处,以离子交换层析DEAE和分子筛纯化蛋白,缓慢复性并在C2C12细胞内检测到其蛋白活性.     

基于Windows位图的数控雕刻加工方法及其应用

Bitmap （BMP） is a widely used format in image processing. With the combination of the digital image processing and computer numerically controlled （NC） techniques, we developed a bitmap-based NC single-step and multi-dot method. An example was provided to illustrate the application and principle of this bitmap-based method in our newly innovated sandblasting glass NC sculpture system.     

A facile approach to construct hybrid multi-shell calcium phosphate gene particles

The calcium phosphate (CaP) particles have attracted much attention in gene therapy. How to construct stable gene particles was the determining factor. In this study,hybrid multi-shell CaP gene particles were successfully constructed. First,CaP nanoparticles served as a core and were coated with DNA for colloidal stabilization. The ξ-potential of DNA-coated CaP nanoparticles was -15 mV. Then polyethylenimine (PEI) was added and adsorbed outside of the DNA layer due to the electrostatic attraction. The ξ-pot...     

粒子加速器中带电粒子最终速度的计算方法比较

带电粒子在示波器（低速）中和在粒子加速器（高速）中的最终速度的计算方法是不一样的。利用相对论的相关知识推导出粒子加速器中带电粒子最终速度的计算公式,并与在示波器中利用牛顿力学计算的结果进行比较,说明利用牛顿力学的计算式是有局限性的,不适用于高能物理中的相关计算,不能随便假设能量数据进行计算,最后得出设置能量数据时要考虑能量与粒子静止能量的比值W/m0c^2的结论。     

A Design Thinking Model Based on Quantitative Electroencephalography in Social Emotional Learning for Attention Deficit Hyperactivity Disorder

To design a social and emotional learning (SEL) skills training program for children with attention deficit hyperactivity disorder (ADHD). Quantitative electroencephalography was analyzed, focusing on the strengths and weaknesses in the brain mapping performance (BMP) of children. A total of 305 participants with and without ADHD were recruited. Theta relative power was analyzed using stepwise multiple regression. Twelve brain locations were further predicted using a design thinking model to develop a reasonable prototype via crossover methods. Both strengths and weaknesses were found at the T5 and F7 brain regions in the ADHD group. The Fz region was a well‐defined predictor in both groups. The co‐predictors of both groups were F3 and F4. No comparison was suggested to enhance positive performance in either group of children. The SEL program could be designed based on a good‐fit model of the BMP of these subcomponents of primary brain functions.     

大分子在固/液界面的吸附行为及应用

由于链状大分子(聚合物)结构的柔韧性和具有一定内旋自由度,所以当它们吸附于界面时,呈现出独特的性质.文章综述了大分子在固/液界面吸附时的概念、特征及影响因素,并对聚合物吸附的应用做了总结.     

Effect of particle loading on heat transfer enhancement in a gas-solid suspension cross flow

Heat transfer between gas-solid multiphase flow and tubes occurs in many industry processes, such as circulating fluidized bed process, pneumatic conveying process, chemical process, drying process, etc. This paper focuses on the influence of the presence of particles on the heat transfer between a tube and gas-solid suspension. The presence of particles causes positive enhancement of heat transfer in the case of high solid loading ratio, but heat transfer reduction has been found for in the case of very low solid loading ratio (M _s of less than 0.05 kg/kg). A useful correlation incorporating solid loading ratio, particle size and flow Reynolds number was derived from experimental data. In addition, thek-∈ two-equation model and the Fluctuation-Spectrum-Random-Trajectory Model (FSRT Model) are used to simulate the flow field and heat transfer of the gasphase and the solid-phase, respectively. Through coupling of the two phases the model can predict the local and total heat transfer characteristics of tube in gas-solid cross flow. For the total heat transfer enhancement due to particles loading the model predictions agreed well with experimental data. Project supported by National Natural Science Foundation for Distinguished Young Scholars (No. 50025618)