Continuous-discontinuous element method for three-dimensional thermal cracking of rocks

Thermal cracking of rocks can significantly affect the durability of underground structures in engineering practices such as geothermal energy extraction,storage of nuclear waste and tunnelling in freezeethaw cycle induced areas.It is a scenario of strong coupled thermomechanical process involving discontinuity behaviours of rocks.In this context,a numerical model was proposed to investigate the thermal cracking of rocks,in a framework of the continuous-discontinuous element method(CDEM)for efficiently capturing the initiation and propagation of multiple cracks.A simplex integration strategy was adopted to account for the influences of temperature-dependent material properties.Several benchmark tests were considered and the obtained results were compared with analytical solutions and numerical results from the literature.The results show that the fracture degree of the cases when considering temperature-dependent material parameters had 10%differences approximately compared with the cases with constant parameters.

Amplification and Bioinformatics Analysis of vscN Gene from Vibrio alginolyticus

[Objectives]The paper was to clone and analyze bioinformatics of vscN gene from Vibrio alginolyticus.[Methods]A pair of specific primers was designed based on the vscN gene sequence of V.alginolyticus HY9901.The full length of vscN gene was amplified by PCR and bioinformatics analysis was performed.[Results]The vscN gene was 1323 bp in total,encoding 440 amino acids,with the theoretical molecular weight of 47.86 kD and the theoretical pI value of 5.89.The online prediction showed that there was no signal peptide and no transmembrane region in VscN.The amino acid sequence had 10 N-myristoylation sites,8 phosphorylation sites(2 protein kinase C phosphorylation sites,6 casein kinase II phosphorylation sites),1 amidation site,11 microbody C-terminal target signal sites,1 ATP/GTP binding site motif A(P ring),and 1 ATPaseαandβsubunit specific site.Homology analysis showed that the VscN protein of V.alginolyticus had high homology with that of V.antiquarius,with a similarity of 95.14%.Phylogenetic tree analysis showed that the VscN of V.alginolyticus was clustered into the same subgroup as that of V.diabolicus and V.antiquarius.Functional domain analysis of VscN protein showed that it had Pfam and AAA domains,and involved in the regulation of bacterial virulence.The three-dimensional structure model of VscN simulated by SWISS-MODEL software was similar to the structure of flagellate-specific ATPase FliH-FliI complex.[Conclusions]The results lay a foundation for further study on the regulatory mechanism of VscN protein on bacterial virulence.

Amplification and Bioinformatics Analysis of h-ns Gene of Vibrio alginolyticus

[Objectives]To amplify the h-ns gene of Vibrio alginolyticus and analyze it by bioinformatics.[Methods]According to the h-ns gene sequence of V.alginolyticus HY9901,a pair of specific primers were designed and amplified by PCR.[Results]The h-ns gene was 408 bp in length and 135 amino acids were encoded.The predicted theoretical protein molecular weight was about 14.98 kD,and the isoelectric point was 4.99.Protein subcellular localization,SignalP 5.0,TMHMM Server 2.0 and SoftBerry-Psite predictions showed that H-NS was located outside the cell membrane,and the protein was unstable and hydrophobic.There was no signal peptide cleavage site,no transmembrane region and no KEGG metabolic pathway.The amino acid sequence contained three phosphorylation sites,one N-terminal myristoylation site and three microsomal C-terminal target signal sites.Using MEGA 5.0,H-NS phylogenetic tree was constructed by ortho-connection method.The results showed that H-NS of V.alginolyticus was closer to H-NS of Vibrio diabolicus.Using SWISS-MODEL,the three-dimensional structure model of H-NS subunit was simulated,which was similar to the crystal structure of Salmonella typhimurium H-NS1-83.[Conclusions]This study lays a foundation for exploring the regulation mechanism of V.alginolyticus H-NS protein on bacterial virulence in the future.

Analysis of long term catalytic performance for isobutane alkylation catalyzed by NMA–AlCl3 based ionic liquid analog

Isobutane alkylation with 2-butene to produce high-quality gasoline was catalyzed by Nmethylacetamide(NMA)-AlCl3 based ionic liquid(IL) analog with a NMA/AlCl3 molar ratio of 0.75 and CuCl modification,which was marked as CuCl-modified 0.75 NMA-1.0 AlCl3.The long-term experiment was carried out in the autoclave operated in continuous mode to investigate the distribution of alkylate under different experimental nodes.The result indicated that the long-term alkylation was divided into three stages:rising,stable,and descending regions.C8 selectivity and molar ratio of trimethylpentanes(TMPs) to dimethylhexanes(DMHs) reached the highest level in the stable region,and research octane number(RON) of alkylate was as high as 97.Anionic Al species([AlbCl7]^-,[A1 CuC15]^-) and cationic Al species([AlCl2 L]^+) from IL analog as two active Lewis acidic species played a catalytic role in the long-term alkylation,whereas the neutral Al species did not participate into the alkylation.Moreover,the structure of CuCl-modified 0.75 NMA-1.0 AlCl3 was destroyed after the deactivation,and CuCl was enriched in the CD2 Cl2-insoluble substance,resulting in a decreasing TMP/DMH ratio.The catalytic lifetime of IL analog was similar with CuCl-modified 0.55 Et3 NHCl-1.0 AlCl3 IL,but IL analog had a lower cost.

A quality by design (QbD) case study on entericcoated pellets: Screening of critical variables and establishment of design space at laboratory scale

The study aims to prepare naproxen enteric-coated pellets(NAP-ECPs)by fluid-bed coating using QbD principle.Risk assessment was firstly performed by using failure mode and effect analysis(FMEA)methodology.A PlacketteBurman design was then used for assessment of the most important variables affecting enteric-coated pellets characteristics.A BoxeBehnken design was subsequently used for investigating the main,interactive,and quadratic effects of these variables on the response.By FMEA we discovered that eight factors should be considered to be high/important risk variables as compared with others.The responses of acid resistance and cumulative drug release were taken as critical quality attributes(CQAs).Pareto ranking analyses indicated that the coating weight gain(X_(7)),triethyl citrate percentage(X_(1))and glycerol monostearate percentage(X_(2))were the most significant factors affecting the selected responses out of the eight high-risk variables.Optimization with response surface method(RSM)further fully clarified the relationship between X_(7),X_(1),X_(2) and CQAs,and design space was established based on the constraints set on the responses.Due to the extreme coincidence of the predicted value generated by model with the observed value,the accuracy and robustness of the model were confirmed.It could be concluded that a promising NAP-ECPs was successfully designed using QbD approach in a laboratory scale.

Corrosion inhibiting performance and mechanism of protic ionic liquids as green brass inhibitors in nitric acid

Four protic ionic liquids(ILs)were synthesized via a one-step method by using benzotriazole(BTA)and benzimidazole as cations,and benzenesulfonic acid and 2-naphthalenesulfonic acid(NSA)as anions.These ILs were used as green corrosion inhibitors for brass specimens in a nitric acid solution.The structure of the protic ILs was characterized by 1H-NMR,13C-NMR,and FT-IR spectroscopy.The effects of the IL structure,IL concentration,acid concentration,and corrosion time on the surface morphology of brass specimens and the inhibition efficiency(η%)of ILs were investigated by the weight loss method combined with SEM and EDS spectroscopy.Polarization curves and impedance spectroscopy were used to analyze the electrochemical corrosion inhibition mechanism of ILs.Results showed that IL synthesis was a proton transfer process,and the proton of the–SO3H group on NSA was deprived by BTA.IL[BTA][NSA],which had a high charge density and large conjugateπband,was the most effective inhibitor for brass corrosion.Theη%of[BTA][NSA]decreased with the increase in acid concentration and corrosion time,which showed an increment with the increase in[BTA][NSA]concentration.The higher theη%of[BTA][NSA]is,the smoother the surface of the brass specimens is,and the smaller the undistributed area of Cu element will be.Corrosion inhibiting mechanism from electrochemical analysis indicated that the addition of[BTA][NSA]increased the polarization resistance of the brass electrode significantly and suppressed both anodic and cathodic reactions.

Ultrasound:The Potential Power for Cardiovascular Disease Therapy

Ultrasound can be considered a mechanical wave for both clinical diagnostic and therapeutic purposes on the basis of its good penetrability and directivity while spreading in solid organs or tissues without any ionizing radiation.As a powerful form of energy,ultrasound,is used for deep-tissue therapy with different sonication parameters.The feasibility of minimally invasive or noninvasive acoustic treatment of a variety of diseases,such as hypertension,arrhythmia,hypertrophic cardiomyopathy,and myocardial infraction,is being explored in animal experiments and clinical trials.In this review,we summarize the biomedical effects of acoustic intervention in experimental and clinical studies,current challenges,and the potential of ultrasound for cardiovascular disease therapy.

Molecular Cloning and Bioinformatics Analysis of crp Gene in Vibrio alginolyticus

[Objectives]The crp gene in Vibrio alginolyticus was studied.[Methods]The crp gene of V.alginolyticus HY9901 was cloned and analyzed by bioinformatics.[Results]The ORF of the crp gene is 633 bp long and the predicted amino acid sequence encompasses 210 amino acid residues.The physicochemical property analysis indicated that the chemical formula of CRP is C_(1051)H_(1704)N_(290)O_(308)S_(10) with a molecular weight of 23.6514 kDa,and its theoretical pI is 7.74.Besides,the protein is stable and hydrophilic.The protein had three protein kinase C phosphorylation site,three casein kinase II phosphorylation site,one N-terminal myristoylation site.The BLAST analysis on the sequence revealed high homology with CRPs in other Vibrio species,and particularly the sequence shares about a homology of 99.52%with the CRP in V.parahaemolyticus.The SWISS-MODEL software simulated the subunit tertiary structural model of the CRP,and the similarity with template 3hif.1.A was 95.71%.[Conclusions]This study provides a reference for the search for efficient protective antigens against vibrosis.

Cloning and Bioinformatics Analysis of TpiA Gene of Vibrio alginolyticus HY9901

[Objectives]To clone and analyze the TpiA gene of Vibrio alginolyticus HY9901.[Methods]According to the TpiA gene sequence of V.alginolyticus,a pair of specific primers was designed,and its full length was amplified by PCR.[Results]The full length of TpiA gene is 771 bp,encoding 256 amino acid residues in total,and the NCBI accession number is OM906798.According to the deduced amino acid sequence,its molecular weight was predicted to be about 26.97548 kDa,and its isoelectric point was 4.78.The amino acid sequence of the N-terminal signal peptide structure was predicted,and it was found that there was no obvious signal peptide cleavage site,no signal peptide,and no transmembrane region;the amino acid sequence contained 3 N-glycosylation sites,4 protein kinase C phosphorylation sites,2 casein kinase II phosphorylation sites,6 N-myristoylation sites,7 microbody C-terminal target signal site,and 1 triose phosphate isomerase active site.The prediction results of protein subcellular localization showed that TpiA may be located in mitochondria or cytoplasm,with probability of 39.1%and 34.8%,respectively.The amino acid sequence of the TpiA gene of V.alginolyticus shared 98.83%-99.61%homology with other Vibrio species,and it was clustered into the same subfamily with Vibrio parahaemolyticus and had a close relationship.In the secondary structure prediction,the proportions ofα-helix,random coil and extended chain were 44.53%,41.41%and 14.06%,respectively,and the similarity of its tertiary structure model to template 1aw1.1.A was 85.16%.[Conclusions]This study is intended to provide a basis for further research on the role of TpiA gene in the type III secretion system and related research on antibiotic resistance.

Bioinformatics Analysis of DNA-binding Response Regulator PhoP in Vibrio alginolyticus

[Objectives]To amplify the DNA-binding response regulator PhoP in Vibrio alginolyticus and analyze its sequence characteristics and subunit structure.[Methods]According to the sequence of the DNA-binding response regulator PhoP in V.alginolyticus,a pair of specific primers was designed for PCR amplification,and the bioinformatics of the sequence amplified was analyzed.Using MEGA 5.0 software,the phoP phylogenetic tree was constructed by the neighbor-joining method.Using SWISS-MODEL software,the three-dimensional structural model of the PhoP subunit was simulated.[Results]The full-length phoP gene was 732 bp,encoding a total of 243 amino acids.The predicted theoretical molecular weight of the protein is about 27.67 kD,and the isoelectric point is 5.09.The prediction results of protein subcellular localization,SignalP 4.0,TMHMM Server 2.0 and SoftBerry-Psite show that PhoP is located in the cytoplasm,and is stable and hydrophobic;there is a signal peptide cleavage site between amino acids 29 and 30,and there is no transmembrane region.The amino acid sequence contains one Asn-glycosylation site,one protein kinase C phosphorylation site,seven casein kinase II phosphorylation sites,one tyrosine kinase phosphorylation site,three myristoylation sites,and seven C-terminal microbody targeting signal sites.The PhoP of V.alginolyticus has high homology with that of Vibrio campbellii.The PhoP subunit of V.alginolyticus has similar configuration to the single-subunit RegX3 protein of Mycobacterium tuberculosis.[Conclusions]This study has a positive effect on the prevention and control of vibriosis and the improvement of the current aquatic economic animal breeding environment.

Establishment and Optimization of Two-dimensional Electrophoresis System for Spleen Proteome of Sillago sihama Forsskal

Taking Sillago sihama Forssk?l as the research object,through the optimization of the extraction method,hydration and isoelectric focusing,a two-dimensional electrophoresis system was established for spleen proteome of S. sihama Forssk?l. The results showed that the twpstep hydration and isoelectric focusing method is better than the hydration and isoelectric focusing integrated method. The protein spots of the spleen of S. sihama Forssk?l were detected by two-dimensional electrophoresis mainly at pH 4. 0-7. 0. The establishment of this technical system will lay a foundation for further research on proteomics of S. sihama Forssk?l in the future.

碳酸物种和氯离子对生物磷灰石磷酸钙成核的影响

磷灰石是骨骼和牙齿等生物硬组织的主要无机成分,对脊椎动物至关重要.生物系统的体液中普遍存在碳酸物种和Cl^(-)离子,了解这些阴离子对生物磷灰石成核过程的影响有助于解释生物矿化的控制作用.理论研究表明,Ca-O配位数在CaP成核和CaP与添加剂的界面相互作用中是一个重要描述符.CaP团簇最外层的Ca^(2+)离子能够通过静电作用吸引碳酸物种和Cl^(-)离子,从而促进CaP相的形成.在碳酸物种和Cl^(-)离子存在的情况下,钙磷石(DCPD)可以转化为羟基磷灰石(HA).平衡氧同位素分馏和振动光谱分析结果表明,Cl^(-)离子掺杂的B型HA是最有可能的生物磷灰石.上述结果可以指导阴离子掺杂的具有生物功能的磷灰石材料的合成.

A Preliminary Study on Silver Isotopic Composition in Polymetallic Ore Deposits in Eastern China

A preliminary survey of silver isotopic composition in four polymetallic ores in eastern China shows a larger variation inδ^(109)Ag from-0.014‰to+0.983‰,which is within the total ranges for the entire respective ore deposit types worldwide.The diversity of silver isotopic compositions in oredeposits reported here and previous studies seemed to preclude simple isotopic links to particular sources,but reflected the silver isotope fractionation in transport-and deposit-related processes instead.Theδ^(109)Ag values in supergene samples from the Qixiashan Pb-Zn-Ag polymetallic deposit are more positive,in consistent with the statistical δ^(109)Ag distribution from-0.4‰to+2.2‰in 36 pieces of supergene ore samples around the World,which reflects the diverse controls on silver isotope fractionation from the first-order thermodynamic effect,reduction-mediated reaction,remobilization of silver with surficial low-temperature weathering processes.The hypogene samples in Dazhuangzi orogenic Au-Ag ore deposit,have δ^(109)Ag values close to 0,which implies that equilibrium partitioning associated with metal sources at the high-temperature does not result in a resolvable difference in silver isotopic compositions.By contrast,the hypogene samples which are dominated by pyrite without visible silver minerals (i.e.,skarn iron ore deposit in Edongnan) have shown the largest variation range of δ^(109)Ag,followed by that from the porphyry copper ore in Zijinshan.It could be concluded that the surface adsorption and/or lattice substitution are important factors to control Ag isotope fractionation in oreforming processes,especially for skarn deposits with only pyrite.The perspective of silver isotope shows great potentials to understand the processes that lead to the concentrations of metals to economic levels and to constrain the physicochemical conditions during ore-mineralization in metallic ore-deposits.

Changes in PAH and 3-MCPDE contents at the various stages of Camellia oleifera seed oil refining

Objectives:Polycyclic aromatic hydrocarbons(PAHs)and 3-monochloropropane-1,2-diol ester(3-MCPDE)were studied in camellia oil.It is important to study the changes in the content of PAHs and 3-MCPDE at different refining stages(from crude oil to the final refined oil product)to elucidate the influence of the refining procedures on their change.Materials and methods:The PAHs and 3-MCPDE in camellia oil from different refining stages(from crude oil to the product)of a plant were analyzed by gas chromatography–mass spectrometry and calculated by the internal standard method.Results:The overall PAH content was(79.64±2.43)μg/kg in crude camellia oil.After refining treatment,the PAH content decreased to(18.75±0.55)μg/kg.The 3-MCPDE content increased during the refining process from 0 mg/kg in the crude oil to 4.62 mg/kg in the refined oil product.Conclusions:This is the first study to simultaneously monitor changes in both PAH and 3-MCPDE contents during the production of camellia oil.These results confirmed the effectiveness of the refining method on PAH removal and the increase in 3-MCPDE at high temperature.It is suggested that novel processing methods or refining parameters need further optimization to decrease the overall concentrations of PAHs and 3-MCPDE in camellia oil.

Bimeron clusters in chiral antiferromagnets

A magnetic bimeron is an in-plane topological counterpart of a magnetic skyrmion.Despite the topological equivalence,their statics and dynamics could be distinct,making them attractive from the perspectives of both physics and spintronic applications.In this work,we demonstrate the stabilization of bimeron solitons and clusters in the antiferromagnetic(AFM)thin film with interfacial Dzyaloshinskii–Moriya interaction(DMI).Bimerons demonstrate high current-driven mobility as generic AFM solitons,while featuring anisotropic and relativistic dynamics excited by currents with in-plane and out-ofplane polarizations,respectively.Moreover,these spin textures can absorb other bimeron solitons or clusters along the translational direction to acquire a wide range of Néel topological numbers.The clustering involves the rearrangement of topological structures,and gives rise to remarkable changes in static and dynamical properties.The merits of AFM bimeron clusters reveal a potential path to unify multibit data creation,transmission,storage,and even topology-based computation within the same material system,and may stimulate spintronic devices enabling innovative paradigms of data manipulations.