Research of caged dynamics of clusters center atoms in Pd_(82)Si_(18) amorphous alloy

To date,there is still a lack of a comprehensive explanation for caged dynamics which is regarded as one of the intricate dynamic behaviors in amorphous alloys.This study focuses on Pd_(82)Si_(18)as the research object to further elucidate the underlying mechanism of caged dynamics from multiple perspectives,including the cage's lifetime,atomic local environment,and atomic potential energy.The results reveal that Si atoms exhibit a pronounced cage effect due to the hindrance of Pd atoms,resulting in an anomalous peak in the non-Gaussian parameters.An in-depth investigation was conducted on the caged dynamics differences between fast and slow Si atoms.In comparison to fast Si atoms,slow Si atoms were surrounded by more Pd atoms and occupied lower potential energy states,resulting in smaller diffusion displacements for the slow Si atoms.Concurrently,slow Si atoms tend to be in the centers of smaller clusters with coordination numbers of 9 and 10.During the isothermal relaxation process,clusters with coordination numbers 9 and 10 have longer lifetimes,suggesting that the escape of slow Si atoms from their cages is more challenging.The findings mentioned above hold significant implications for understanding the caged dynamics.

Synthesis and Structure of A Novel Caged Bicyclic Phosphate Flame Retardant

PI novel caged bicyclic phosphate flame retardant tri(1-oxo-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane-methyl) phosphate (Trimer) was synthesized from 1-oxo-4-hydroxymethyl-2,6,7-trioxa-1-phosphabicyclo [2.2.2] octane (PEPA) and phosphorus oxychloride in this paper. Its structure was characterized by elemental analysis. FTIR, H-1 NMR. P-31 NMR and X-ray diffraction analysis.

Photochemical Reaction of Benzoin Caged Compound： Time-Resolved Fourier Transform Infrared Spectroscopy Study

The benzoin group caged compound has received strong interests due to its excellent photo- deprotection properties and wide use in chemical and biological studies. We used timeresolved infrared spectroscopy to investigate the photochemical reaction of the benzoin caged compound, o-（2-methylbenzoyl）-DL-benzoin under 266 nm laser irradiation. Taking advantage of the specific vibrational marker bands and the IR discerning capability, we have detected and identified the uncaging product 2-methylbenzoic acid, and two intermediate radicals of benzoyl and 2-methylbenzoate benzyl in the transient infrared spectra. Our results provide spectral evidence to support the homolytic cleavage reaction of C-C=O bond in competition with the deprotection reaction. Moreover, the product yields of 2-methylbenzoic acid and benzoyl radical were observed to be affected by solvents and a largely water contalning solvent can be in favor of the deprotection reaction.

Apoptotic activity of caged xanthones from Garcinia hanburyi in cholangiocarcinoma cell lines

AIM:To investigate the growth inhibitory mechanism of four caged xanthones from Garcinia hanburyi in cholangiocarcinoma(CCA) KKU-100 and KKU-M156 cells.METHODS:Four caged xanthones,selected on the basis of their anticancer potency and chemical structure diversities(i.e.isomorellin,isomorellinol,forbesione and gambogic acid) were used in this study.Growth inhibition of these caged xanthones was determined using the sulforhodamine B assay.Induction of apoptosis was assessed by observing cell morphology,ethidium bromide and acridine orange staining and DNA fragmentation assay.Levels of apoptotic-related gene and protein expressions were determined by a real-time reverse transcriptase polymerase chain reaction and Western blotting analysis,respectively.RESULTS:The compounds were found to inhibit growth of both cell lines in a dose-dependent manner and also showed selective cytotoxicity against the cancer cells when compared with normal peripheral blood mononuclear cells.Growth suppression by these compounds was due to apoptosis,as evidenced by the cell morphological changes,chromatin condensation,nuclear fragmentation,and DNA ladder formation.At the molecular level,these compounds induced down-regulation of Bcl-2 and survivin proteins with up-regulation of Bax and apoptosisinducing factor proteins,leading to the activation of caspase-9 and-3 and DNA fragmentation.The functional group variations did not appear to affect the anticancer activity with regard to the two CCA cell lines;however,at a mechanistic level,isomorellinol exhibited the highest potency in increasing the Bax/Bcl-2 protein expression ratio(120 and 41.4 for KKU-100 and KKU-M156,respectively) and in decreasing survivin protein expression(0.01 fold as compared to control cells in both cell lines).Other activities at the molecular level indicate that functional groups on the prenyl side chain may be important.CONCLUSION:Our findings for the first time demonstrate that four caged xanthones induce apoptosis in CCA cells which is mediated through a mitochondriadependent signaling pathway.

A new cytotoxic caged polyprenylated xanthone from the resin of Garcinia hanburyi

A new caged polyprenylated xanthone, gambogic aldehyde （1）, was isolated from the resin of Garcinia hanburyi. Its structure was elucidated on the basis of spectral data including 1D and 2D NMR data. In addition, the antiproliferative ability of compound 1 was determined in mouse leukemia P388 and P388/ADR cells.

Synthesis of Caged Bicyclic Phosphate Derivatives

Seven caged bicyclic phosphate compounds were synthesized by using 1-oxo-4-hydroxymethyl-2, 6, 7-trioxa-l-pho-sphabicyclo [ 2.2.2 ] octane （PEPA） as starting material. Within them were three PEPA derivatives containing single caged bicyclic phosphate structure（ 1a, 2a, 3a）, another three PEPA deviratives containing two caged bicyclic phosphate structures（1b, 2b, 3b） and one devirative（1c） containing three caged bicyclic phosphate structures. Structures of the products were characterized by FTIR, ^1H NMR, elemental analysis and TG analysis. The reaction conditions were also discussed. Thermal analysis showed they had high thermal stability and excellent char-forming ability. Besides, these compounds had pentaerythritol bone and flame retardant dements of phosphorus, bromine or nitrogen simultaneously in their molecules, endowed them with good fire retardancy, and made them can be used as intumescent flame retardant.

PROMOTION EFFECT OF MELAMINE ON FLAME RETARDANCY OF EPOXY RESINS CONTAINING CAGED BICYCLIC PHOSPHATE

Caged bicyclic phosphate （CBP） and its dimelamine salt （PDS） were synthesized and added to epoxy resins to obtain the flame retarded epoxy resin composites. The flammability of the composites was characterized by the limiting oxygen index （LOI） and cone calorimeter tests. The LOI values of flame retarded composites increase consistently with the increase of flame retardant amounts, and they are almost the same when the loading of CBP is the same as that of PDS, although the phosphorus content of PDS is much lower than that of CBP. The total heat release increases in the order of CBP30/ER 〈 PDS30/ER 〈 PDS15/ER 〈 CBPI5/ER, whereas that of specific extinction area is CBP15/ER 〉 CBP30/ER 〉 PDS30/ER ≌ PDS15/ER. PDS exhibits more effective inhibition of oxidation of combustible gases. In the tests of thermogravimetric analyses （TG） and Fourier transform infrared spectroscopy （FT-IR）, it is found that the degradation of the composites is influenced greatly by the addition of flame retardants. By scanning electron microscopy （SEM）, a thick and tight char-layer is observed for PDS30/ER, resulting from the interaction of nitrogen species with phosphorus species. Therefore, the combination of CBP with melamine in the flame retarded system can improve the flame retardancy greatly.

Study of Flame Retardation of Polycarbonate Modified by Polyhedral Oligomeric Silsesquioxane and Caged Bicyclic Phosphate

The flame-retarded polycarbonate（PC） has been made with octaphenyl polyhedral silsesquioxane（OPS） and/or caged bicyclic phosphate（Trimer）.Thermal gravimetric analysis（TGA）,Fourier-transform infrared（FTIR）,TGA-FTIR,limiting oxygen index（LOI）,and mechanical tests have been employed to characterize the modified PC.The additives of OPS and Trimer in PC have been proved to be effective flame-retardants because of the synergistic interaction between the elements of P and Si.The role of OPS and Trimer in PC degradation are different：OPS participates in the charring of PC,while Trimer makes PC degrade in advance.In addition,OPS and Trimer induced obvious differences in the mechanical properties of PC.

Study on the C_(60)-Caged States of H_2 and N_2

The states of small molecule H2 and N2 in the Coo cage have been studied. It is shown that the molecular stable configUrations of the caged states exhibits little change compared with the free states, but the bond intensities of the caged states have become much stronger.

Analysis of Symbolism of the Caged Bird in the Novel --Is He Living or Is He Dead？

As one of Mark Twain＇ s most classic short story, ＂ Is He Living or Is He Dead＂ does not reflect the major problems and the serious drawbacks of society fi＇om the surface significance of novel, however, the events described in the novel can actually touch sensitive topic as well as the shortcomings of the era where, pointedly disclose the nature of society at that time. Mark Twain＇s short story tries to use this caged bird imagery to criticize the camouflage events occur and makes irony of this tragic story behind the social problems. Little caged bird in the novel contains profound social implications and is worthy of scrutiny and research.

On Identity Reconstruction of Black Woman in I Know Why the Caged Bird Sings

Maya Angelou(1928-2014)is a celebrated African American woman writer.She's not only an autobiographer,a poet,an educator,but also a politician,an actress and a director.Her first autobiographical novel I Know Why the Caged Bird Sings is a significant milestone of the African American literature of woman.The novel depicts Marguerite life experience from the age of 3 to the age of17,recording how she breaks through the bondage of racial discrimination and sex prejudice,and realizes self-consciousness.From the perspective of post-colonist criticism and feminism,this thesis analyses how the protagonist suffered from the"othering"under the colonial discourse and patriarchal ideology and how she got out of the bondage and reconstruct her identity.Finally,it is concluded that only if the black women break through the cage of race and gender,accept and reconstruct their identities,can they gain the real emancipation and respect.

颈前路减压融合ROI-C^(TM)自锁系统治疗退行性颈椎病的Meta分析

目的:颈前路减压融合术是治疗退行性颈椎病的经典手术方式,钉板的使用增加了融合率及稳定性的同时,间接导致了邻近椎体退变和术后吞咽困难的发生。文章通过Meta分析方法比较ROI-C^(TM)自锁系统和传统融合器联合钉板内固定治疗退行性颈椎病患者的临床结果和并发症情况,为颈前路减压融合术中内固定方式的选择提供循证学支持。方法:检索中国知网、万方、维普、PubMed、Cochrane Library、Web of Science和Embase数据库,检索关于颈前路减压融合术中应用ROI-C^(TM)自锁系统与融合器联合钉板内固定治疗退行性颈椎病的中英文文献。检索时间范围为各数据库建库至2023年7月。由2名研究者严格按照纳入与排除标准选择文献,采用Cochrane偏倚风险工具对随机对照试验进行质量评价,NOS量表对队列研究进行质量评价。采用RevMan 5.4软件进行Meta分析。结局指标包括手术时间、术中出血量、日本骨科协会(Japanese Orthopaedic Association Scores,JOA)评分、颈椎功能障碍指数、C_(2)-C_(7)Cobb角、融合率、邻近椎体退变发生率、融合器沉降率和吞咽困难发生率。结果:共纳入13项研究,其中回顾性队列研究11项,随机对照试验2项,共1136例患者,ROI-C组569例,融合器联合钉板组567例。Meta分析结果显示:ROI-C组与融合器联合钉板组在手术时间(MD=-15.52,95%CI:-18.62至-12.42,P<0.00001),术中出血量(MD=-24.53,95%CI:-32.46至-16.61,P<0.00001),术后邻近节段退变率(RR=0.40,95%CI:0.27-0.60,P<0.00001)和术后总吞咽困难发生率(RR=0.18,95%CI:0.13-0.26,P<0.00001)均具有显著性差异。两者在术后JOA评分、颈椎功能障碍指数、C_(2)-C_(7)Cobb角、融合率和融合器沉降率方面无显著性差异(P≥0.05)。结论:在颈椎前路减压融合术中应用ROI-C^(TM)自锁系统与传统融合器联合钉板内固定治疗退行性颈椎病均可达到满意的临床效果,ROI-C^(TM)自锁系统操作更加简单,相比融合器联合钉板内固定能明显减少手术时间及术中出血量,在减少术后吞咽困难及邻近节段退变发生率等方面具有明显优势,对于跳跃型颈椎病及邻椎病翻修患者,更加推荐使用ROI-C^(TM)自锁系统。但鉴于其可能存在较高的沉降率,对于多节段且合并融合器沉降高危因素如骨质疏松、椎体终板破损的退行性颈椎病患者,仍建议使用融合器联合钉板内固定。

国家距离对中国农产品出口贸易的影响

文章基于2002—2021年中国对共建“一带一路”56国的农产品出口贸易数据,实证分析了国家距离对中国农产品出口贸易的影响。结果显示,综合国家距离对中国农产品出口贸易具有负向影响;不同维度国家距离对农产品出口贸易的影响有所差异,文化距离、制度距离的影响显著为负,地理距离、经济距离则呈正向影响;亚非地区、中低收入水平、市场潜力较大的共建国家与中国的国家距离对中国农产品出口贸易的负向影响更为明显;双边投资协定签订时长、建交时长、友好城市建立数量均在国家距离对中国农产品出口贸易的影响中存在门槛效应,当各变量高于门槛值时,国家距离对中国农产品出口贸易的负向影响将会被削弱。

基于MRI椎体和终板骨质量评分对经椎间孔椎间融合术后cage沉降的预测价值

目的探讨基于MRI的椎体骨质量评分(vertebral bone quality score,VBQ)和终板骨质量评分(endplate bone quality score,EBQ)在经椎间孔腰椎椎间融合(transforaminal lumbar interbody fusion,TLIF)术后cage沉降中的预测价值。方法因腰椎退行性疾病在我院行TLIF手术的226例患者,根据术后有无cage沉降将患者分为沉降组和非沉降组,比较两组患者VBQ和EBQ评分。通过多元回归分析cage沉降的危险因素,并根据受试者工作特征曲线下面积(AUC)评估VBQ和EBQ预测TLIF术后cage沉降的能力。结果226例患者中30例出现术后cage沉降。沉降组VBQ(3.8±0.4)分,EBQ(5.1±0.7)分,明显高于非沉降组(3.1±0.6)分和(4.2±1.0)分,差异有统计学意义(P<0.001)。多元回归分析显示VBQ(OR=4.258,95%CI:1.983~9.142,P<0.001)和EBQ(OR=1.971,95%CI:1.212~3.203,P=0.006)评分越高,发生cage沉降风险也越大。受试者工作特征曲线结果显示VBQ的AUC为0.843,EBQ的AUC是0.864。VBQ和EBQ预测cage沉降的最佳阈值分别为3.480(敏感性90%;特异性75.5%)和4.620(敏感性96.7%;特异性74.5%)。结论术前VBQ或EBQ评分越高,TLIF术后发生cage沉降风险越大。其中EBQ可能是一个更好的预测融合术后cage沉降的指标。

不同融合材料辅助颈前路椎间盘切除减压融合术的应用研究

目的:观察不同融合材料在颈椎间盘突出患者颈前路椎间盘切除减压融合术(ACDF)中的应用效果。方法:选取平顶山市第一人民医院2021年5月至2022年10月收治的90例颈椎间盘突出患者为研究对象,开展前瞻性研究,基于随机对照原则将入组患者分为自体组(30例)、异体组(30例)及联合组(30例),自体组术中采用修饰后的自体髂骨治疗,异体组术中采用同种异体骨结合Cage椎间融合器治疗,联合组术中采用修饰后的自体髂骨+同种异体骨+Cage椎间融合器治疗,比较三组术后颈椎疼痛情况、颈椎高度、颈椎功能恢复情况、植骨融合率及并发症发生情况。结果:联合组术后2、4周视觉模拟量表(VAS)评分均低于自体组、异体组(P<0.05);联合组术后2、4周颈椎高度均高于自体组、异体组(P<0.05);联合组随访第3、6、12个月时的日本骨科学会治疗分数(JOA)评分均高于自体组、异体组(P<0.05);联合组随访第3、6、12个月时的植骨融合率均高于自体组、异体组(P<0.05);联合组术后并发症发生率低于自体组、异体组(P<0.05)。结论:修饰后的自体髂骨+同种异体骨+Cage椎间融合器联合用于ACDF手术可促进患者颈椎高度及功能恢复,对提高植骨融合率,降低并发症发生风险具有积极意义。

A Photocaged Azidosugar for Light-Controlled Metabolic Labeling of Cell-Surface Sialoglycans

The photocaging strategy has been widely used for activating biomolecules and hence regulating the underlying biological processes with high temporal and spatial resolution.Herein,we integrate this strategy into metabolic glycan labeling,which enables optical-ly-controlled metabolic labeling of cell-surface sialoglycans with azides.N-Azidoacetylmannosamine(ManNAz)is caged with a 4,5-dimethoxy-2-nitrobenzyl(DMNB)group at the anomeric hydroxyl group to block its cellular metabolism.After feeding to the cells,irradiation with 365 nm UV light or 405 nm visible light cleaves the photocage and generates ManNAz within the cells.ManNAz is metabolically converted to azido sialic acid,which is then incorporated into cell-surface sialoglycans.We demonstrated spatial and temporal control of this strategy by specifically labeling sialoglycans on a single cell and tracking the metabolism of ManNAz based on light-triggered pulse-chase labeling,respectively.The light-controlled metabolic glycan labeling strategy should facilitate probing of glycosylation in complex biological systems with high spatiotemporal precision.

Cytotoxic 7-Methoxylated Caged Xanthones from the Twigs of Garcinia oligantha

Main observation and conclusion Nineteen unprecedented 7-methoxylated caged xanthones(1—19)were isolated from the twigs of Garcinia oligantha under the guidance of NMR spectroscopy.Their structures and absolute configurations were demonstrated by extensive spectroscopic data,single-crystal X-ray diffraction,electronic circular dichroism(ECD)calculations,and the modified Mosher's method.Compound 1 is a rare scalemic 7-methoxylated neo-caged xanthone,which was resolved using HPLC with CD detection on a chiral-phase AD column,and compounds 2—3 are rare 7-methoxylated caged xanthones with the hydrogenatedΔ^(8(8a))double bond.Fourteen compounds exhibited promising inhibitory activities against four human cancer cell lines with IC50 values ranging from 1.9 to 14.3μmol/L.A cell apoptosis analysis using flow cytometry showed that compound 11 could induce apoptosis in a dose dependent manner.Moreover,PARP,caspase-9,and Bcl-2 western blotting suggested that compound 11-induced apoptosis may be involved in caspase-dependent pathway.

Optopharmacological control of TRPC channels by coumarin-caged lipids is associated with a phototoxic membrane effect

Photouncaging of second messengers has been successfully employed to gain mechanistic insight of cellular signaling path- ways. One of the most enigmatic processes of ion channel regulation is lipid recognition and lipid-gating of TRPC channels, which represents pivotal mechanisms of cellular Ca2＋ homeostasis. Recently, optopharmacological tools including caged lipid mediators became available, enabling an unprecedented level of temporal and spatial control of the activating lipid species within a cellular environment. Here we tested a commonly used caged ligand approach for suitability to investigate TRPC sig- naling at the level of membrane conductance and cellular Ca2＋ handling. We report a specific photouncaging artifact that is triggered by the cage structure coumarin at UV illumination. Electrophysiological characterization identified a light-dependent membrane effect of coumarin. UV light （340 nm） as used for photouncaging, initiated a membrane conductance specifically in the presence of coumarin as low as 30 pmol L-1 concentrations. This conductance masked the TRPC3 conductance evoked by photouncaging, while TRPC-mediated cellular Ca2＋ responses were largely preserved. The observed light-induced membrane effects of the released caging moiety may well interfere with certain cellular functions, and prompt caution in using couma- fin-caged second messengers in cellular studies.

Selective photosynthesis of Z-olefins through crystalline metal-organic cage-initiated expeditious cascade reactions

The semi-hydrogenation of alkyne to form Z-olefins with high conversion and high selectivity is still a huge challenge in the chemical industry.Moreover,flammable and explosive hydrogen as the common hydrogen source of this reaction increases the cost and danger of industrial production.Herein,we connect the photocatalytic hydrogen evolution reaction and the semihydrogenation reaction of alkynes in series and successfully realize the high selective production of Z-alkenes using low-cost,safe,and green water as the proton source.Before the cascade reaction,a series of isomorphic metal–organic cage catalysts(Co_(x)Zn_(8−x)L_(6),x=0,3,4,5,and 8)are designed and synthesized to improve the yield of the photocatalytic hydrogen production.Among them,Co_(5)Zn_(3)L_(6) shows the highest photocatalytic activity,with a H_(2) generation rate of 8.81 mmol g^(−1) h^(−1).Then,Co_(5)Zn_(3)L_(6) is further applied in the above tandem reaction to efficiently reduce alkynes to Z-alkenes under ambient conditions,which can reach high conversion of>98%and high selectivity of>99%,and maintain original catalytic activity after multiple cycles.This“one-pot”tandem reaction can achieve a highly selective and safe stepwise conversion from water into hydrogen into Z-olefins under mild reaction conditions.

Using fracture-based continuum modeling of coupled geomechanical-hydrological processes for numerical simulation of hydraulic fracturing

This paper describes numerical simulation of hydraulic fracturing using fracture-based continuum modeling(FBCM)of coupled geomechanical-hydrological processes to evaluate a technique for high-density fracturing and fracture caging.The simulations are innovative because of modeling discrete fractures explicitly in continuum analysis.A key advantage of FBCM is that fracture initiation and propagation are modeled explicitly without changing the domain grid(i.e.no re-meshing).Further,multiple realizations of a preexisting fracture distribution can be analyzed using the same domain grid.The simulated hydraulic fracturing technique consists of pressurizing multiple wells simultaneously:initially without permeating fluids into the rock,to seed fractures uniformly and at high density in the wall rock of the wells;followed by fluid injection to propagate the seeded fracture density hydraulically.FBCM combines the ease of continuum modeling with the potential accuracy of modeling discrete fractures and fracturing explicitly.Fractures are modeled as piecewise planar based on intersections with domain elements;fracture geometry stored as continuum properties is used to calculate parameters needed to model individual fractures;and rock behavior is modeled through tensorial aggregation of the behavior of discrete fractures and unfractured rock.Simulations are presented for previously unfractured rock and for rock with preexisting fractures of horizontal,shallow-dipping,steeply dipping,or vertical orientation.Simulations of a single-well model are used to determine the pattern and spacing for a multiple-well design.The results illustrate high-density fracturing and fracture caging through simultaneous fluid injection in multiple wells:for previously unfractured rock or rock with preexisting shallow-dipping or horizontal fractures,and in situ vertical compressive stress greater than horizontal.If preexisting fractures are steeply dipping or vertical,and considering the same in situ stress condition,well pressurization without fluid permeation appears to be the only practical way to induce new fractures and contain fracturing within the target domain.