Tomatidine-stimulated maturation of human embryonic stem cell-derived cardiomyocytes for modeling mitochondrial dysfunction

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) have been reported to exhibit immature embryonic or fetal cardiomyocyte-like phenotypes. To enhance the maturation of hESC-CMs, we identified a natural steroidal alkaloid, tomatidine, as a new substance that stimulates the maturation of hESC-CMs. Treatment of human embryonic stem cells with tomatidine during cardiomyocyte differentiation stimulated the expression of several cardiomyocyte-specific markers and increased the density of T-tubules. Furthermore, tomatidine treatment augmented the number and size of mitochondria and enhanced the formation of mitochondrial lamellar cristae. Tomatidine treatment stimulated mitochondrial functions, including mitochondrial membrane potential, oxidative phosphorylation, and ATP production, in hESC-CMs. Tomatidine-treated hESC-CMs were more sensitive to doxorubicin-induced cardiotoxicity than the control cells. In conclusion, the present study suggests that tomatidine promotes the differentiation of stem cells to adult cardiomyocytes by accelerating mitochondrial biogenesis and maturation and that tomatidine-treated mature hESC-CMs can be used for cardiotoxicity screening and cardiac disease modeling.Subject terms: Heart failure, Embryonic stem cells, Stem-cell differentiation     

聚氯乙烯膜碘离子选择电极在溴碘离子共存体系分析中的应用

介绍了聚氯乙烯膜碘离子选择电极(PVC-I-ISE)的制备方法,电极对碘离子的能斯特响应斜率为59 mV/pI,响应的线性范围为4.0×10-5~1.0×10-2mol.L-1,检出限为1.6×10-5mol.L-1,低于用银ISE的检出限,电极的使用寿命为一个月以上。将制备的碘离子选择电极作为指示电极用于对溴、碘混合离子体系进行连续分别电位滴定,并与以银电极为指示电极的电位滴定方法进行了比较。结果表明用PVC-I--ISE作指示电极,可在I--Br-共存的混合溶液中进行两离子的连续电位滴定,而用银-ISE时则不能。     

回流冷凝试样消解-电感耦合等离子体原子发射光谱法测定铝合金中铅、镉、铬和汞

采用回流冷凝技术,将电子电气产品中铝合金样品用稀盐酸加热溶解后,用电感耦合等离子体原子发射光谱法(ICP-AES)同时测定电子电气产品铝合金中铅、镉、铬和汞,方法的检出限为0.001 8~0.019 mg.L-1,方法的回收率和精密度分别为92.3%~96.1%和0.16%~3.71%。     

Theoretical Study on Properties of New Isotope 265Bh

The properties of nuclei belonging to the newly observed α-decay chain starting from 265Bh have been studied. The axially deformed relativistic mean-field calculation with the force NL-Z2 has been performed in the blockedBCS approximation. Some ground state properties such as binding energies, deformations, spins, and parities, as well as Q-values of the α-decay for this decay chain have been calculated and compared with known experimental data. Good agreement is found. The single-particle spectrum of the nucleus 265 Bh is studied and some new magic numbers are found,while the magnitudes of the shell gaps in superheavy nuclei are much smaller than those of nuclei before the actinium region, and the Fermi surfaces are close to the continuum. Thus the superheavy nuclei are usually not stable. The The methods which give good agreement with the data are selected.     

40Ar+238U 实验介绍

主要介绍了利用兰州重离子加速器提供的270 MeV的40Ar离子束轰击238U靶，通过熔合蒸发反应进行试合成Z=110附近的新同位素的实验情况。分析了目前关于超重核研究的现状并描述了这次实验的目的、 可行性分析、 实验装置以及实验过程等。本次实验仍然用氦喷嘴技术对产物进行传输， 并用一套具有数对探测器组的转轮收集探测系统对产物进行收集和测量。 The state of the experiment to produce the new isotopes around Z=110 are presented in this paper. The emphasis is laid upon introducing the experiment purpose, the set up and the feasibility for producing this objective nuclide. In the experiment the new isotopes were produced by the complete fusion evaporation reaction of 238U with 270 MeV 40Ar at the Sector Focus Cyclotron (SFC) of Heavy Ion Research Facility in Lanzhou(HIRFL). The reaction products were also transported and collected by using the helium jet technique and rotating wheel apparatus.     

两种芳香植物非挥发性组分抗氧化和对DNA损伤的保护作用

采用6种化学发光体系和两种比色体系研究了芳香植物罗勒和香柠檬的非挥发性组分(简称罗勒、香柠檬)直接清除活性氧、活性氮和对^.OH引起的DNA损伤的保护作用。结果表明,罗勒和香柠檬不仅能直接清除O2,而且可抑制黄嘌呤氧化酶的活性从而减少O2的产生。罗勒和香柠檬也能有效清除^.OH、H2O2、ONOO^.和DPPH^.,两者相比,香柠檬除对^.OH的清除作用弱于罗勒外,清除以上各种自由基的能力均强于罗勒。结果还显示,罗勒和香柠檬都能抑制脂质过氧化,明显地抑制和延缓DNA损伤,起到预防型抗氧化剂和断链型抗氧化剂的双重作用。这些结果表明,罗勒和香柠檬的非挥发性组分是有效的、多功能的天然抗氧化剂和自由基清除剂。     

车载空调器设计平台研究与开发

针对车载空调器设计手工计算繁琐、设计周期长等诸多不便利特点,研制开发了基于VB和SOLIDEDGE软件的车载空调器设计平台。该平台不仅具有车载空调器整机开发、机组设备单独设计或选型以及换热器参数化设计的功能,还兼容了家用空调器设计开发的能力。平台运行平稳,结果直观可靠。     

非均匀采样干涉数据光谱反演技术研究

干涉光谱成像仪获取的干涉数据是一种中间数据,需要进行光谱反演才能够得到目标光谱数据,傅里叶变换方法是常规的光谱反演方法。由于干涉数据中存在非均匀采样问题,若忽略光谱混叠,直接采用快速傅里叶变换会导致反演光谱的失真,难以满足实时处理需求。针对非均匀采样干涉数据的光谱反演需求,将插值及非均匀快速傅里叶变换(NUFFT)方法应用到光谱反演处理中,对过采样及部分欠采样情况下的非均匀采样干涉数据,提出了相应的光谱反演方法,并分析了方法的适用性。最后对过采样及部分欠采样情况下的光谱反演方法进行计算机仿真,过采样情况下采用NUFFT方法反演光谱的精度要明显高于插值方法,而部分欠采样情况下插值方法反演光谱的精度要明显高于NUFFT方法,并对欠采样造成的光谱混叠有一定的修正,验证了方法的有效性。     

Analytical model of an acoustic diode comprising a superlattice and a nonlinear medium

We give an analytical analysis to the acoustic propagation in an acoustic diode (AD) model formed by coupling a superlattice (SL) with a nonlinear medium. Analytical solutions of the acoustic transmission are obtained by studying the propagations in the SL and the nonlinear medium separately with the conventional transfer-matrix method and a perturbation technique. Compared with the previous numerical method, the proposed approach contributes a better physical insight into the intrinsic mechanism of acoustic rectification and helps us to predict the performance of an AD within the effective rectifying bands in a simple way. This is potentially significant for the practical design and fabrication of AD devices.     

采用四分之一波长谐振器的P波段高温超导滤波器研制

本文采用四分之一波长螺旋型谐振器设计并制作了6节P波段高温超导滤波器.谐振器一端开路,另一端与接地块连接实现短路.接地块与封装盒的盒壁之间通过点焊硅铝丝进行连接.通过电磁场仿真分析了硅铝丝的数量对滤波器性能的影响.滤波器未经调谐的测试结果与仿真结果符合得很好,其通带内最小插损仅为0.07dB,反射损耗优于17.9dB,且第一个寄生通带位于基频中心频率的三倍处.表明通过硅铝丝点焊实现接地的方法对滤波器性能的影响很小,且采用四分之一波长谐振器可以有效抑制二倍频.