X射线晶体学结合电子晶体学在复杂无机晶体结构解析中的应用

自然界中的材料,比如无机材料,有机材料,生物材料等等,均有其独特的物理和化学性质。而材料的性能又与材料的结构息息相关,只有充分了解了材料的结构,才能更加深入的研究材料性质。因此,材料结构的确定在化学、物理、生物等学科中的显得尤为重要。X射线晶体学作为传统的结构解析技术仍然是目前最重要的结构解析手段,但是对于复杂结构,X射线衍射晶体学解析结构也存在一些不足,往往需要其他技术手段相补充才能完成复杂结构的结构解析。电子晶体学虽然起步比X射线晶体学晚,但是,经过近几十年的发展,已经是结构解析领域一个非常重要的手段。本文将主要介绍X射线晶体学结合电子晶体学在复杂无机晶体结构解析中的应用。

Effect of intravenous transplantation of bone marrow mesenchymal stem cells on neurotransmitters and synapsins in rats with spinal cord injury

Bone marrow mesenchymal stem cells were isolated, purified and cultured in vitro by Percoll density gradient centrifugation combined with the cell adherence method. Passages 3 5 bone marrow mesenchymal stem cells were transplanted into rats with traumatic spinal cord injury via the caudal vein. Basso-Beattie-Bresnahan scores indicate that neurological function of experimental rats was significantly improved over transplantation time （1-5 weeks）. Expressions of choline acetyltransferase, glutamic acid decarboxytase and synapsins in the damaged spinal cord of rats was significantly increased after transplantation, determined by immunofluorescence staining and laser confocal scanning microscopy. Bone marrow mesenchymal stem cells that had migrated into the damaged area of rats in the experimental group began to express choline acetyltransferase, glutamic acid decarboxylase and synapsins, 3 weeks after transplantation. The Basso-Beattie- Bresnahan scores positively correlated with expression of choline acetyltransferase and synapsins. Experimental findings indicate that intravenously transplanted bone marrow mesenchymal stem cells traverse into the damaged spinal cord of rats, promote expression of choline acetyltransferase, glutamic acid decarboxylase and synapsins, and improve nerve function in rats with spinal cord injury.

Combination of bone marrow mesenchymal stem cells and brain-derived neurotrophic factor for treating spinal cord injury

BACKGROUND： Because bone marrow mesenchymal stem cells （BMSCs） do not secrete sufficient brain-derived neurotrophic factor （BDNF）, the use of exogenous BDNF could improve microenvironments in injured regions for BMSCs differentiation. OBJECTIVE： To analyze recovery of the injured spinal cord following BMSCs venous transplantation in combination with consecutive injections of BDNF. DESIGN, TIME AND SETTING： A randomized, controlled animal experiment was performed at the Central Laboratory of First Hospital and Anatomical Laboratory, Fujian Medical University from October 2004 to May 2006. MATERIALS： Human BDNF was purchased from Sigma, USA. METHODS： A total of 44 New Zealand rabbits were randomly assigned to model （n = 8）, BDNF （n = 12）, BMSC （n= 12）, and BMSC＋BDNF （n= 12） groups. Spinal cord （I-2）injury was established with the dropping method. The model group rabbits were injected with 1 mL normal saline via the ear margin vein; the BDNF group was subdurally injected with 100 μg/d human BDNF for 1 week; the BMSC group was injected with 1 mL BMSCs suspension （2 × 10^6/mL） via the ear margin vein; and the BMSC＋BDNF group rabbits were subdurally injected with 100 μg/d BDNF for 1 week, in addition to BMSCs suspension via the ear margin vein. MAIN OUTCOME MEASURES： BMSCs surface markers were detected by flow cytometry. BMSCs differentiation in the injured spinal cord was detected by immunofluorescence histochemistry. Functional and structural recovery, as well as morphological changes, in the injured spinal cord were respectively detected by Tarlov score, horseradish peroxidase retrograde tracing, and hematoxylin ＆ eosin staining methods at 1, 3, and 5 weeks following transplantation. RESULTS： Transplanted BMSCs differentiated into neuronal-like cells in the injured spinal cord at 3 and 5 weeks following transplantation. Neurological function and pathological damage improved following BMSC ＋ BDNF treatment compared with BDNF or BMSC alone （P 〈 0.01 or P 〈 0.05）. CONCLUSION： BMSCs venous transplantation in combination with BDNF subdural injection benefits neuronal-like cell differentiation and significantly improves structural and function of injured spinal cord compared with BMSCs or BDNF alone.

Tanshinone IIa antagonizes spinal ischemia/reperfusion injury by interfering with upstream glutamic acid factors

Based on the hypothesis that upstream factor inhibition results in better treatment effects than downstream factor inhibition,the present study interfered with glutamic acid（Glu）-released upstream factors,such as Glu transporter function and Na＋-K＋-adenosine triphosphatases（ATPase）activity relativly.Rats with spinal cord ischemia/reperfusion injury received intraperitoneal injections of tanshinone Ila and Glu uptake and Na＋-K＋-ATPase activity were increased.Results showed that tanshinone Ila influenced Glu-released upstream factors following spinal ischemia/reperfusion injury and protected against spinal ischemia/reperfusion injury.

Multidisciplinary approach for the management of term pregnancy complicated by Eisenmenger syndrome

Pregnancy in patients with Eisenmenger syndrome(ES)is associated with high maternal mortality rates of 30%‒50%,or even up to 65%in the case of a cesarean section(Yuan,2016).Here,we report a case of term pregnancy complicated with ES and severe pulmonary artery hypertension(PAH),which was managed by a multidisciplinary team(MDT)and resulted in an uncomplicated delivery via elective cesarean section.The goal of this study is to emphasize the importance of multidisciplinary approach in the management of pregnancy with ES,which can profoundly improve maternal and infant outcomes.

Propagation Characteristics of Partial Discharge Pulses in the Cable

In order to determine the type and location of partial discharge in cable, the effect of partial discharge (PD) pulse propagation in the cable is studied. Firstly, pulses are injected to cables of different lengths so that input and output signal can be measured at both ends of each cable. Then the transfer function of pulse propagation path can be defined. Secondly, high-voltage test is done in the cable joint with man-made defects, and typical PD waveforms are gotten. Seven parameters of waveform characteristics are calculated, including edge times, waveform shape and statistical characteristics. They are used to distinguish different types of PD or distances of the pulse propagation. Thus the efficiency of PD recognition in cable can be improved.

Neutron Diffraction Study on the Magnetic Structure of 153EuMnO3-δ: One Way to Assess the Magnetic Structure of EuMnO3-δ

Owing to the strong neutron absorption of 151Eu,151Eu free 153EuMnO3-δhas been synthesized to collect the neutron diffraction data for analyzing the magnetic structure of EuMnO3-δ.The obtained neutron diffraction data of 153EuMnO3-δindicates that the magnetic diffraction peaks corresponding to cAAFM(canted A-type antiferromagnetic)phase can be observed,but the magnetic diffraction peaks corresponding to expected ICAFM(incommensurate antiferromagnetic)phase may be too weak to be observed.

Control of lupus activity during pregnancy via the engagement of IgG sialylation:novel crosstalk between IgG sialylation and pDC functions

Immunoglobulin(IgG)glycosylation affects the effector functions of IgG in a myriad of biological processes and has been closely associated with numerous autoimmune diseases,including systemic lupus erythematosus(SLE),thus underlining the pathogenic role of glycosylation aberration in autoimmunity.This study aims to explore the relationship between IgG sialylation patterns and lupus pregnancy.Relative to that in serum samples from the control cohort,IgG sialylation level was aberrantly downregulated in serum samples from the SLE cohort at four stages(from preconception to the third trimester of pregnancy)and was significantly associated with lupus activity and fetal loss during lupus pregnancy.The type I interferon signature of pregnant patients with SLE was negatively correlated with the level of IgG sialylation.The lack of sialylation dampened the ability of IgG to suppress the functions of plasmacytoid dendritic cells(pDCs).RNA-seq analysis further revealed that the expression of genes associated with the spleen tyrosine kinase(SYK)signaling pathway significantly differed between IgG-and deSia-IgG-treated pDCs.This finding was confirmed by the attenuation of the ability to phosphorylate SYK and BLNK in deSia-IgG.Finally,the coculture of pDCs isolated from pregnant patients with SLE with IgG/deSia-IgG demonstrated the sialylation-dependent anti-inflammatory function of IgG.Our findings suggested that IgG influences lupus activity through regulating pDCs function via the modulation of the SYK pathway in a sialic acid-dependent manner.

Borates as a new direction in the design of oxide ion conductors

Lowering the operating temperature of solid oxide fuel cells(SOFCs)has extensively stimulated the development of new oxide ion conductors.Here,inspired by the structural commonalities of oxide ion conductors,the inability to accommodate oxygen vacancies in the rigid,isolated,3-fold tetrahedral rings of SrSi/GeO_(3)-based materials,and the considerable flexibility of BO_(n) polyhedra in terms of coordination number,rotation,deformation,and linkage,we report the first borate-base family of oxide ion conductors,(Gd/Y)_(1−x)Zn_(x)BO_(3−0.5x),through combined computational prediction and experimental verification.The oxygen vacancies in(Gd/Y)BO_(3)can be accommodated by forming B_(3)O_(8)units in isolated,3-fold,tetrahedral rings of B_(3)O_(9)and transported through a cooperative mechanism of oxygen exchange between the B_(3)O_(9)and B_(3)O_(8)units,which is assisted by the intermediate opening and extending of these units.This study opens a new scientific field of the borate system for designing and discovering oxide ion conductors.

Erratum to:Borates as a new direction in the design of oxide ion conductors(vol 65,issue 10,page 2737,2022)

In the version of the article originally published in the volume 62,issue 10,2022 of Sci.china Mater.(page 2737-2745,https://doi.org/10.1007/s40843-022-2044-3).The chemical shift reported in Figure 5f for the^(11)B solid-state NMR spectra is incorrect because no parameter correction was performed during data processing.