Syntheses,Structure and Thermal Analysis of a Cobalt Coordination Polymer with Multiform Helical Features Based on Flexible Iododicarboxylate Ligand and N-donor Ancillary Ligand

A new 3D complex,[Co（L）（bpe）0.5（H2O）2]n（1,H2 L = 5-iodo-benzene-1,3-dioxyacetic acid,bpe = 1,2-bis（4-pyridyl）ethylene）,has been hydrothermally synthesized and structurally characterized by elemental analysis,IR and X-ray diffraction.It is formulated as C16H16 Co INO8,crystallizes in monoclinic,space group P21/c,with a = 9.806（2）,b = 6.5492（13）,c = 28.187（8） A,β = 100.12（3）°,V = 1782.0（7） A^3,Z = 4,Dc = 1.998 g/m^3,F（000） = 1052,Μr = 536.13,the final R = 0.0393 and w R = 0.0858 for 3134 observed reflections with I 〉 2σ（I）.Complex 1 displays a 3D framework with multiform helical features,left-and right-handed triple helical braids and single helical chains,which can be simplified as a new type of（3,4）-connected lattice with a（6·10^2）（6^2·10^4） SchlAfli symbol.Moreover,the thermal analysis of complex 1 has also been investigated.

Fatigue behaviors and damage mechanisms for Nb_(3)Sn triple-helical structure at liquid nitrogen temperature

Nb_(3)Sn triple‐helical structure is the elementary structure in the superconducting cable of ITER magnets and undergoes prolonged fatigue loading in extreme environments leading to serious damage degradation.In this paper,the fatigue behaviors of the Nb_(3)Sn triple‐helical structure have been investigated by the strain cycling fatigue experiments at liquid nitrogen temperature.The results indicate that Nb_(3)Sn triple‐helical structures with short twist‐pitches possess excellent fatigue damage resistance than that of long twist‐pitches,such as longer fatigue life,slower damage degradation,and smaller energy dissipation.Meanwhile,a theoretical model of damage evolution has been established to reveal the effects of twist‐pitches on fatigue properties for triplehelical structures,which is also validated by the present experimental data.Furthermore,one can see that the Nb_(3)Sn superconducting wires in a triple‐helical structure with the shorter twist‐pitches have a larger elongation of helical structure and less cyclic deformation,which can be considered as the main mechanism of better fatigue damage properties for the triple‐helical structures during the strain cycling processes.These findings provide a better understanding of the fatigue properties and damage mechanisms for Nb_(3)Sn triple‐helical structures in superconducting cables of ITER magnets.

Novel collagen VI mutations identified in Chinese patients with Ullrich congenital muscular dystrophy

Background:We determined the clinical and molecular genetic characteristics of 8 Chinese patients with Ullrich congenital muscular dystrophy(UCMD).Methods:Clinical data of probands were collected and muscle biopsies of patients were analyzed.Exons of COL6A1,COL6A2 and COL6A3 were analyzed by direct sequencing.Mutations in COL6A1,COL6A2 and COL6A3 were identifi ed in 8 patients.Results:Among these mutations,5 were novel[three in the triple helical domain(THD)and 2 in the second C-terminal(C2)domain].We also identified five known missense or in-frame deletion mutations in THD and C domains.Immunohistochemical studies on muscle biopsies from patients showed reduced level of collagen VI at the muscle basement membrane and mis-localization of the protein in interstitial and perivascular regions.Conclusions:The novel mutations we identified underscore the importance of THD and C2 domains in the assembly and function of collagen VI,thereby providing useful information for the genetic counseling of UCMD patients.