低价锆氧化物Zr_(3)O的结构、热力学和弹性性质第一性原理研究

采用第一性原理系统地研究3种Zr_(3)O晶形(空间群分别为R3c(斜方六面体)、R32(斜方六面体)和P6322(六面体))的晶格动力学及其与温度相关的热力学和力学性质。计算得到的3种Zr_(3)O晶形的晶体结构参数与实验结果一致。此外,证明3种Zr_(3)O结构在动力学和热力学上均具有稳定性。获得了3种Zr_(3)O晶形在0~1500 K温度范围内的熵、焓、吉布斯自由能、比热容、热膨胀系数和弹性模量等性质。发现3种Zr_(3)O晶形在0K时的相对稳定性顺序为Zr_(3)O(R3c)>Zr_(3)O(R32)>Zr_(3)O(P6_(3)22);然而,在50 K时Zr_(3)O(R3c)转变成Zr_(3)O(R32),在540K时转变为Zr_(3)O(P6_(3)22)。相较于其他2种Zr_(3)O相,Zr_(3)O(R32)表现出更优越的力学性能。

Interferon-γpriming enhances the therapeutic effects of menstrual blood-derived stromal cells in a mouse liver ischemia-reperfusion model

BACKGROUND Mesenchymal stem cells(MSCs)have been used in liver transplantation and have certain effects in alleviating liver ischemia-reperfusion injury(IRI)and regulating immune rejection.However,some studies have indicated that the effects of MSCs are not very significant.Therefore,approaches that enable MSCs to exert significant and stable therapeutic effects are worth further study.AIM To enhance the therapeutic potential of human menstrual blood-derived stromal cells(MenSCs)in the mouse liver ischemia-reperfusion(I/R)model via interferon-γ(IFN-γ)priming.METHODS Apoptosis was analyzed by flow cytometry to evaluate the safety of IFN-γpriming,and indoleamine 2,3-dioxygenase(IDO)levels were measured by quantitative real-time reverse transcription polymerase chain reaction,western blotting,and ELISA to evaluate the efficacy of IFN-γpriming.In vivo,the liver I/R model was established in male C57/BL mice,hematoxylin and eosin and TUNEL staining was performed and serum liver enzyme levels were measured to assess the degree of liver injury,and regulatory T cell(Treg)numbers in spleens were determined by flow cytometry to assess immune tolerance potential.Metabolomics analysis was conducted to elucidate the potential mechanism underlying the regulatory effects of primed MenSCs.In vitro,we established a hypoxia/reoxygenation(H/R)model and analyzed apoptosis by flow cytometry to investigate the mechanism through which primed MenSCs inhibit apoptosis.Transmission electron microscopy,western blotting,and immunofluorescence were used to analyze autophagy levels.RESULTS IFN-γ-primed MenSCs secreted higher levels of IDO,attenuated liver injury,and increased Treg numbers in the mouse spleens to greater degrees than untreated MenSCs.Metabolomics and autophagy analyses proved that primed MenSCs more strongly induced autophagy in the mouse livers.In the H/R model,autophagy inhibitors increased the level of H/R-induced apoptosis,indicating that autophagy exerted protective effects.In addition,primed MenSCs decreased the level of H/R-induced apoptosis via IDO and autophagy.Further rescue experiments proved that IDO enhanced the protective autophagy by inhibiting the mammalian target of rapamycin(mTOR)pathway and activating the AMPK pathway.CONCLUSION IFN-γ-primed MenSCs exerted better therapeutic effects in the liver I/R model by secreting higher IDO levels.MenSCs and IDO activated the AMPK-mTOR-autophagy axis to reduce IRI,and IDO increased Treg numbers in the spleen and enhanced the MenSC-mediated induction of immune tolerance.Our study suggests that IFN-γ-primed MenSCs may be a novel and superior MSC product for liver transplantation in the future.

Treatment of backwater in bauxite flotation plant and optimization by using Box-Behnken design

Flotation indexes gradually decrease with the increase of cycle time of the backwater in bauxite floatation,and discharge of backwater brings environmental risk.In this study,methods such as Fenton-oxidation,adsorption and coagulation were used in the treatment of backwater,the flotation indexes were checked after backwater treatments,and Box-Behnken design(BBD)was used in the optimization of the main operating parameters.The results reveal that flotation indexes are effectively improved after coagulation treatment by polyaluminum ferric chloride(PAFC).The optimum parameters predicted by BBD are pH 7.55,1.09 g/L PAFC dosage and temperature of 25℃.Under these optimum conditions,a maximum recovery of Al2O3 of 82.83%and a minimum A/S of 1.30 of tailings are gained,while the deviations are less than 3%from the predicted values.These findings encourage the application of BBD for the optimization of critical parameters in backwater treatment.

Singchia and Gunnaria,two new genera of Orchidaceae

Singchia Z. J. Liu ＆ L. J. Chen, a new orchid genus, is established based on the new species S. malipoensis Z. J. Liu ＆ L. J. Chen found in southeast Yunnan, China. The new genus is related to Pteroceras, from which it differs by having a lip with its basal margins immovably adnate to the lower part of the pendent column foot, a thin-walled spur, and very unequally and deeply split pollinia, each with a distinct caudicle. In addition to a discussion on Ascocentrum pusillum, a species of questionable placement, another new genus, namely Gunnaria S. C. Chen ex Z. J. Liu ＆ L. J. Chen, is set up and a new combination, namely G. pusilla （Aver.） Z. J. Liu ＆ L. J. Chen, is made. The new genus Gunnaria differs from its allyAscocentrum by having a cross-shaped pollinarium, sulcate or split pollinia, each with a distinct caudicle attached to a common linear stipe much longer than either pollinia or viscidium, and strongly incurved side lobes of the lip.

Multifunctional role of microRNAs in mesenchymal stem cell-derived exosomes in treatment of diseases

Mesenchymal stem cells can be replaced by exosomes for the treatment of inflammatory diseases,injury repair,degenerative diseases,and tumors.Exosomes are small vesicles rich in a variety of nucleic acids[including messenger RNA,Long non-coding RNA,microRNA(miRNA),and circular RNA],proteins,and lipids.Exosomes can be secreted by most cells in the human body and are known to play a key role in the communication of information and material transport between cells.Like exosomes,miRNAs were neglected before their role in various activities of organisms was discovered.Several studies have confirmed that miRNAs play a vital role within exosomes.This review focuses on the specific role of miRNAs in MSC-derived exosomes(MSC-exosomes)and the methods commonly used by researchers to study miRNAs in exosomes.Taken together,miRNAs from MSC-exosomes display immense potential and practical value,both in basic medicine and future clinical applications,in treating several diseases.

Phylogenetic incongruence in Cymbidium orchids

Cymbidium,which includes approximately 80 species,is one of the most ornamental and cultivated orchid genera.However,a lack of markers and sparse sampling have posed great challenges to resolving the phylogenetic relationships within the genus.In the present study,we reconstructed the phylogenetic relationships by utilizing one nuclear DNA(nrITS)and seven plastid genes(rbcL,trnS,trnG,matK,trnL,psbA,and atpI)from 70 species(varieties)in Cymbidium.We also examined the occurrence of phylogenetic conflict between nuclear(nrITS)and plastid loci and investigated how phylogenetic conflict bears on taxonomic classification within the genus.We found that phylogenetic conflict and low support values may be explained by hybridization and a lack of informative characteristics.Our results do not support previous classification of the subgenera and sections within Cymbidium.Discordance between gene trees and network analysis indicate that reticulate evolution occurred in the genus Cymbidium.Overall,our study indicates that Cymbidium has undergone a complex evolution.

Manual reduction with traditional small splints for distal radius fracture in older patients

Objective:To investigate the effect of manual reduction with traditional small splints fixation for distal radius fractures in older patients in the emergency department.Methods:Older patients(aged at least 60 years)with distal radius fractures were enrolled in this study.The patients were randomly divided into the treatment group and the control group.The treatment group was treated with manual reduction and small splints fixation.The control group was treated with manual reduction and resin plaster fixation.Before treatment,after reduction,and 3 months after treatment,the palmar tilt angle,ulnar deviation angle,and radial length were recorded.Before treatment and 3 months after treatment,the Cooney wrist joint scores were recorded.The time of fracture healing and related adverse events during the treatment were recorded.Results:Before treatment and after reduction,there were no statistically significant differences between the two groups in palmar tilt angle,ulnar deviation angle,or radial length(P>0.05).Three months after treatment,the palmar tilt angle,ulnar deviation angle,and radial length of the treatment group were better than those of the control group(P<0.05).The Cooney wrist scores of the treatment group was significantly higher than that of the control group three months after the treatment(P<0.05).The time of fracture healing of the treatment group was shorter than that of the control group,but the difference was no statistically significant(P>0.05).Conclusions:Compared with resin plaster fixation,traditional small splints fixation for distal radius fractures in older patients have the advantages of less loss of fracture reduction and faster functional recovery.Besides,the method is simple and low cost thus,it needs to be promoted.

The Predictive Value of On-treatment Virological Response for Sustained Virological Response in Patients with Chronic Hepatitis C Receiving a Personalized Treatment Program

To investigate the effects of individualised treatment with peginterferon alpha-2a(40 kD)plus ribavirin in Chinese patients with CHC.Methods Total of 297 consecutive Chinese patients were enrolled,including 250 nave cases and 47 cases who were previously treated.Treatment duration was determined according to viral genotypes,prior treatment history and viral responses at week 4,12 and 24.Results Totally,235 patients(79.1%)completed treatment and 186(87.3%)achieved SVR.And 219 out of 289(75.8%)patients achieved HCV RNA negative at week 4(RVR)and 259 of 276(93.8%)at week 12.Among the 164 patients with RVR who completed follow-up,158(96.3%)achieved SVR.Patients with RVR had lower baseline viral loads than patients without RVR(P=0.034).The positive predictive value(PPV)of RVR for SVR was 90.7%(OR 2.10 vs.non-RVR,95%CI:0.50-8.7).Similar outcomes were observed among patients with HCV undetectable at week 12.Conclusions Viral suppression by week 4 is associated with a high rate of treatment success in treatment nave and experienced patients receiving individualized CHC therapy.

An edible fruit from the Jurassic of China

Frugivory is an important ecological tie between animals and angiosperms.It plays an important role in the evolution of food webs and energy flow networks in the ecosystem.However,little is known about how old this relationship can be due to lack of relevant fossil evidence.Here,the authors report a fossil fruit,Jurafructus gen.nov.,a putative angiosperm from the Middle-Late Jurassic(>164 Ma)of Daohugou Village,Inner Mongolia,China,which provides the currently earliest evidence of frugivory.The fossil is a more or less three-dimensionally preserved coalified drupe that has been damaged by animals in two different ways.The pericarp,in addition to the seed coat surrounding parenchyma seed contents,is suggestive of an angiospermous affinity,as such a 3+3 structure is distinct from a three-layered seed coat in gymnosperms.The seed possesses a distal micropyle,attached on the base of the pericarp,suggestive of a former orthotropous ovule in the gynoecium.The damaged pericarp of Jurafructus suggests that firugivory can be dated back to the Middle-Late Jurassic.Apparently,the ecological relationship between angiosperms and animals extends deep into the fossil record.

Numerical study of a highly sensitive surface plasmon resonance sensor based on circular-lattice holey fiber

A new design of surface plasmon resonance(SPR)sensor employing circular-lattice holey fiber to achieve highsensitivity detection is proposed.The sensing performance of the proposed sensor is numerically investigated and the results indicate that our proposed SPR sensor can be applied to the near-mid infrared detection.Moreover,the maximum wavelength sensitivity of our proposed sensor can reach as high as 1.76×10^(4)nm/refractive index unit(RIU)and the maximum wavelength interrogation resolution can be up to 5.68×10^(-6)RIU when the refractive index(RI)of analyte lies in(1.31,1.36).Thanks to its excellent sensing performance,our proposed SPR sensor will have great potential applications for biological analytes detection,food safety control,bio-molecules detection and so on.

Current status and future prospects of mesenchymal stem cell therapy for liver fibrosis

Liver fibrosis is the end-stage of many chronic liver diseases and is a significant health threat. The only effective therapy is liver transplantation, which still has many problems, including the lack of donor sources, immu- nological rejection, and high surgery costs, among others. However, the use of cell therapy is becoming more prev- alent, and mesenchymal stem cells （MSCs） seem to be a promising cell type for the treatment of liver fibrosis. MSCs have multiple differentiation abilities, allowing them to migrate directly into injured tissue and differentiate into hepatocyte-like cells. Additionally, MSCs can release various growth factors and cytokines to increase hepatocyte regeneration, regress liver fibrosis, and regulate inflammation and immune responses. In this review, we summarize the current uses of MSC therapies for liver fibrosis and suggest potential future applications.

Hierarchical self-assembly of triangular metallodendrimers into the ordered nanostructures

We designed and constructed a new family of 608 dendritic dipyridyl donors, from which two novel triangular metallodendrimers were successfully prepared via coordination-driven self-assembly.Inspired by the existence of multiple intermolecular interactions（e.g., p–p stacking and CH–p interactions） imposed by the DMIP-functionalized poly（benzyl ether） dendrons, their hierarchical selfassembly behaviors were studied in various mixed solvents by using scanning electron microscopy（SEM）. Interestingly, it was found that the morphologies of the obtained metallodendrimers were highly depended on the dendron generation. For example, the first-generation metallodendrimer was able to hierarchically self-assemble into the spherical nanostructures in various mixed solvents. However, the nanofibers were observed for the second-generation metallodendrimer under the similar conditions.Furthermore, the driven force for the formation of such ordered nanostructures was investigated by using1 H NMR and fluorescence spectroscopy.

Pillarene-Involved Metallic Supramolecular Nanostructures

Pillarenes(or pillararenes),as a new and rapidly developing class of covalent macrocycles,have stimulated a tremendous upsurge of interest in supramolecular chemistry because of their unique features and potentials in fabri-cating functional materials.In addition,metallo-supramolecular chemistry has grown steadily over the last few decades.The presence of metal in supramolecular architectures enables the systematic tuning of their properties and endows them with optical,magnetic,and electric etcetera unusual properties.The marriage of these two fields offers new possibilities for the fabrication of novel functional materials and devices.This review article provides an over-view of recent advancements on pillararene-based metallic supramolecular assemblies.The fabrication and func-tionalities of pillararene-decorated metallic macrocycles,metal-organic frameworks(MOFs),and metal nanoparti-cles are comprehensively summarized and discussed.

A new family of supramolecular multiferrocenyl rhomboids:Synthesis,characterization,and their electrochemical behavior

Two novel,supramolecular,multiferrocenyl rhomboids 5 and 6 have been successfully constructed from newly designed 60 ferrocenyl donor precursor 1 via coordination-driven self-assembly.The structures of all multiferrocenyl rhomboids were characterized by multinuclear NMR（~1H and ^（31）P）,CSI-TOF-MS, and PM6 semi-empirical molecular simulation,and their electrochemical behaviors have been investigated.

Construction of Metallacycle-Linked Heteroarm Star Polymers via Orthogonal Post-Assembly Polymerization and Their Intriguing Self-Assembly into Large-Area and Regular Nanocubes

of main observation and conclusion In recent years,synthesis of hybrid heteroarm star polymer with precisely defined arms has evolved to be one of the most attractive topics within polymer chemistry.In this study,we present the successful synthesis of metallacycle-linked heteroarm star polymers(HASPs)composed of crystalline poly(e-caprolactone)(PCL)and polyacrylate(poly(N-isopropylacrylamide)(PNIPAM)segments via combination of ring-opening polymerization(ROP)and reversible addition-fragmentation chain transfer(RAFT)controlled radical polymerization.Firstly,a hexagonal metallacycle containing three hydroxy groups and three chain transfer agent moieties at the alternative vertexes was designed and synthesized based on the general principle of coordination-driven self-assembly.Subsequently,upon combination of two orthogonal post-assembly polymerizations,a new family of HASPs containing a well-defined hexagonal metallacycle with precisely controlled position of polymer arms was facilely prepared.Interestingly,the obtained HASPs could spontaneously self-assemble into large-area and regular cubic nanoparticles in tetrahydrofuran(THF)/methanol(MeOH)mixed solvents under specific conditions as confirmed by scanning electron microscopy(SEM)and atomic force microscopy(AFM).This study provides a simple route to the controllable preparation of HASPs,and opens up a new way for further study on self-assembly of different HASPs systems.