Solution conformation of the response regulator proteins from Deinococcus radiodurans studied by SAXS

In this paper the solution conformation of the response regulator proteins from Deinococcus radiodurans was studied by small-angle X-ray scattering (SAXS). The SAXS curves of Dr-rrA in solutions were obtained at Beamline 1W2A of Beijing Synchrotron Radiation Facility (BSRF). Two possible conformations of the response regulator proteins, compact and incompact conformations, have been represented by the known crystallographic structures. And theoretical solution scattering curves of the two possible conformations were calculated and fitted to the experimental scattering curve of Dr-rrA, respectively. The result indicates that the solution conformation of the response regulator proteins is inclined to the compact one, which is in agreement with the result of biochemical experiments.     

Properties of the ν7/2-[503]（f7/2） band in 185Pt

High-spin states in ¹⁸⁵Pt have been reinvestigated via the reaction ¹⁷³Yb(¹⁶O, 4n) at a beam energy of 90 MeV. The previously known band based on the ν7/2^-[503](f_7/2) Nilsson orbital has been extended to higher spin states. Properties of the ν7/2^-[503](f_7/2) band have been discussed with an emphasis on the evolution of configuration while increasing the spin.     

ITER TF铠甲焊缝力学性能研究

ITER TF线圈的CICC导体套管由316LN不锈钢管采用氩孤焊自熔对焊连接而成.选择三种不同的316LN不锈钢管为研究对象,它们分别为母材管、焊接未变形管和焊接后经过8%的冷作变形和650℃下200小时的老化处理的316LN不锈钢管,在室温下对这三种型号的不锈钢管进行拉伸试验,对前两种材料进行冲击试验,同时在4.2...     

纳米低温保护剂导热机理分析

纳米低温保护剂溶液比传统的低温保护剂溶液具有更好的导热性能,纳米微粒能够显著提高低温保护剂溶液的降温速率.本文探讨了纳米低温保护剂溶液导热性能的影响因素,提出了纳米低温保护剂导热模型,并通过与实验测得的数据进行了比对分析,结果表明所提出的模型是合理的.     

Brainin A,a novel flavanol from Brainea insignis

A novel flavanol bearing phenylpropionic acid moiety at C-4 through a C-C bonding,named brainin A(1),was isolated from the rhizomes of Brainea insignis.Its structure was elucidated on the basis of spectral data including 2D NMR and HR-ESI-MS.     

A novel method for the determination of trace copper in cereals by dispersive liquid-liquid microextraction based on solidification of floating organic drop coupled with flame atomic absorption spectrometry

A novel,simple,rapid,efficient and environment-friendly method for the determination of trace copper in cereal samples was developed by using dispersive liquid-liquid microextraction based on solidification of floating organic drop(DLLME-SFO) followed by flame atomic absorption spectrometry.In the DLLME-SFO,copper was complexed with 8-hydroxy quinoline and extracted into a small volume of 1-dodecanol,which is of low density,low toxicity and proper melting point near room temperature. The experimental parameters affecting the extraction efficiency were investigated and optimized.Under the optimum conditions, the calibration graph exhibited linearity over the range of 0.5—500 ng/mL with the correlation coefficient(r) of 0.9996.The enrichment factor was 122 and the limit of detection was 0.1 ng/mL.The method was applied to the determination of copper in the complex matrix samples such as rice and millet with the recoveries for the spiked samples at 5.0 and 10.0 u,g/g falling in the range of 92.0-98.0%and the relative standard deviation of 3.9-5.7%.     

Synthesis of (3S,4R)-bengamide E

（3S,4R）-Bengamide E（2） was synthesized starting from D-glucono-δ-lactone（3） and the key deoxygenation step from 13 to 15 was achieved by the application of NaBH₃CN and ZnI₂.Compared with natural bengamide E（1）,the synthetic compound（35,4R）-bengamide E（2） was inactive against the cell growth of HUVEC and cancer cells.These data represent the significance of the stereochemistry at C-3 and C-4 of bengamides for structural recognition and binding with the target（s）.     

Two new phenethanol glycosides from Ligustrum robustum

Two new phenethanol glycosides,named ligurobustoside P（1）,ligurobustoside Q（2） have been isolated from the leaves of Ligustrum robustum,together with the known compound angoroside A（3） which was firstly isolated from this species.The structures of the two new phenethanol glycosides（1-2） were elucidated by a combination of high-resolution electron ionization mass spectrometry（HR-ESI-MS）,¹H NMR,¹³C NMR,HMQC,and HMBC spectra for the first time.     

Interaction between Janus Green B and bovine serum albumin:Electrochemistry and spectroscopy studies

In this study,voltammetric and spectroscopic investigation of the interaction between Janus Green B(JGB) and bovine serum albumin(BSA) was reported.The interaction was observed at Britton-Robinson buffer(pH 7.0).When JGB was added to solution containing BSA,the peak currents of BSA decrease with the increasing of JGB concentrations which is due to the interaction of JGB and BSA.The binding constant of JGB with BSA was obtained by voltammetric data.Also,this interaction was supported by means of UV-vis spectroscopic measurements.The UV-vis absorption spectra of JGB in the presence of BSA decrease with the increasing of BSA concentrations.     

New insight into surface properties of LB film of an amphiphilic terpolymer

Amphiphilic terpolymer(TPR) exhibits good film-forming behavior on pure water observed by means ofπ-A isotherms.To gain insight into physical properties of TPR,the films have been deposited on silicon substrates at different surface pressure by Langmuir-Blodgett(LB) technique.It was found that the increase in peak intensities of stretching mode was due to orderly packing of the films.The contact angles increased with increasing surface pressure,indicating an increase in hydrophobicity due to dense packing of chains of TPR.The cyclic voltammetric measurements indicated that TPR showed good current shielding effect for electron-transfer.In a word,LB films of TPR can produce a variety of structures with varied topography,enabling us to control not only the functionality of the surface,but also the interfacial transport characteristics.