The selective activation of C-H bonds is pivotal in catalysis for converting hydrocarbons into value-added chemicals.Ethylbenzene dehydrogenation to styrene is crucial process to produce polystyrene and its derivative...The selective activation of C-H bonds is pivotal in catalysis for converting hydrocarbons into value-added chemicals.Ethylbenzene dehydrogenation to styrene is crucial process to produce polystyrene and its derivatives used in synthetic materials.Herein,K-Cr@Y with zeolite-encaged isolated O=Cr(VI)=O species modified by extraframework potassium ions is constructed,showing remarkable performance in CO_(2)-promoted ethylbenzene dehydrogenation with initial ethylbenzene conversion of 66%and styrene selectivity of 96%,outperforming other M-Cr@Y catalysts(M=Li,Na,Rb,Cs).Extraframework potassium ions can modulate the electron density of zeolite-encaged Cr(VI)species and therefore facilitate C–H bond activation in ethylbenzene molecules.The gradual reduction of zeolite-encaged O=Cr(VI)=O to less active Cr(IV)=O species by dihydrogen during ethylbenzene dehydrogenation is evidenced by comprehensive characterization results,and Cr(IV)=O can be re-oxidized to O=Cr(VI)=O species upon simple calcination regeneration.The results from in situ DRIFT spectroscopy elucidate the critical promotion role of CO_(2)in ethylbenzene dehydrogenation over K-Cr@Y by retarding the over-reduction of zeolite-encaged Cr species to inactive Cr(III)species and suppressing coke deposition.This study advances the rational design of non-noble metal catalysts for CO_(2)-promoted ethylbenzene dehydrogenation with zeolite-encaged high valence transition metal ions modulated by extraframework cations.展开更多
Plant bacterial diseases have infiicted substantial economic losses in global crop,fruit,and vegetable production.The conventional methods for managing these diseases typically rely on the application of antibiotics.H...Plant bacterial diseases have infiicted substantial economic losses in global crop,fruit,and vegetable production.The conventional methods for managing these diseases typically rely on the application of antibiotics.However,these antibiotics often target the growth factors of the pathogenic bacteria,leading to the accumulation and emergence of drug-resistant strains,which exacerbates antibiotic resistance.Innovative methods are urgently needed to treat and prevent the toxicity caused by these pathogenic bacteria.Targeting virulence mechanisms in pathogens is a globally recognized and effective strategy for mitigating bacterial resistance.TypeⅢsecretion system(T3SS)serves as a crucial virulence determinant in Gram-negative pathogens,and its non-essentials for pathogen growth renders it an ideal target.Targeting the T3SS holds significant potential to alleviate selective pressure for resistance mutations in pathogens.Therefore,targeting T3SS in pathogenic bacteria,while preserving their growth,has emerged as a novel avenue for the development of antimicrobial drugs.In recent years,a multitude of small molecular inhibitors targeting T3SS have been identified.This article offers a comprehensive review of T3SS inhibitors in plant pathogens,while also presenting the latest research advancements in this research direction.展开更多
WC–Co cemented carbides, well-known as the conventional tooling materials, have not been successfully produced by one step additive manufacturing processes such as selective laser melting(SLM) yet. The microstructure...WC–Co cemented carbides, well-known as the conventional tooling materials, have not been successfully produced by one step additive manufacturing processes such as selective laser melting(SLM) yet. The microstructure evolution as well as WC grain growth behavior has rarely been investigated in detail during SLM process. In this study, the WC–Co cemented carbides with different Co contents(12–32 wt%) were prepared by optimized SLM processes for comparative investigation of densification behavior, microstructure characterization and mechanical property. The increase in Co content in feedstock carbide granules can improve the densification behavior during SLM process. The SLM processed WC-12 Co shows larger average WC grain size and higher percentage of coarser WC grains as compared with both WC-20 Co and WC-32 Co. The microstructure characterization, combined with finite element simulation, shows the WC grain growth mechanisms include agglomeration and dissolution-deposition of WC during SLM process and agglomeration of WC is an important mechanism especially for WC–Co cemented carbides with Co content as low as 12 wt%. The comparison between horizontal(perpendicular to the SLM laser beam) and vertical(parallel to the SLM laser beam) cross sections of carbides shows that SLM process introduces a certain degree of microstructure and mechanical behavior anisotropy for WC-12 Co, WC-20 Co, and WC-32 Co.展开更多
BACKGROUND No guideline recommends antiviral therapy for hepatitis B e antigen(HBeAg)-positive chronic hepatitis B patients with persistently normal alanine aminotransferase levels and a high hepatitis B virus(HBV)DNA...BACKGROUND No guideline recommends antiviral therapy for hepatitis B e antigen(HBeAg)-positive chronic hepatitis B patients with persistently normal alanine aminotransferase levels and a high hepatitis B virus(HBV)DNA viral load.AIM To evaluate the feasibility and safety of a Chinese herbal formula as a therapeutic option for chronic HBV infection.METHODS In total,395 patients(30–65 years old)with confirmed HBeAg-positive chronic hepatitis B infection and persistently normal alanine aminotransferase were randomized to receive either Chinese herbal formula or placebo for 96 wk.Endpoints to evaluate therapeutic efficacy included:(1)HBV DNA levels decreased to less than 4 log10 IU/mL at weeks 48 and 96;and(2)HBeAg clearance and seroconversion rates at weeks 48 and 96.RESULTS HBV DNA levels≤4 log10 IU/mL were 10.05%at week 48 and 18.59%at week 96 in the treatment group.The HBeAg clearance and conversion rates were 8.54%and 8.04%at week 48 and 16.08%and 14.57%at week 96,respectively.However,HBV DNA levels≤4 log10 IU/mL were 2.55%and 2.55%at weeks 48 and 96,respectively,and the HBeAg clearance rates were 3.06%and 5.61%at weeks 48 and 96,respectively,in the control group.The quantitative hepatitis B surface antigen and HBeAg levels at baseline and changes during the treatment period as well as the alanine aminotransferase elevation at weeks 12 and 24 were strong predictors of HBeAg clearance.CONCLUSION High rates of HBV DNA reduction,HBeAg clearance and seroconversion could be achieved with Chinese herbal formula treatments,and the treatments were relatively safe for HBeAg-positive chronic hepatitis B-infected patients with persistently normal alanine aminotransferase.The ability of the compound to modulate host immune function probably contributed to this effect.展开更多
BACKGROUND Studies show that the antifibrotic mechanism of taurine may involve its inhibition of the activation and proliferation of hepatic stellate cells(HSCs). Since the molecular mechanism of taurine-mediated anti...BACKGROUND Studies show that the antifibrotic mechanism of taurine may involve its inhibition of the activation and proliferation of hepatic stellate cells(HSCs). Since the molecular mechanism of taurine-mediated antifibrotic activity has not been fully unveiled and is little studied, it is imperative to use "omics" methods to systematically investigate the molecular mechanism by which taurine inhibits liver fibrosis.AIM To establish a network including transcriptomic and protein-protein interaction data to elucidate the molecular mechanism of taurine-induced HSC apoptosis.METHODS We used microarrays, bioinformatics, protein-protein interaction(PPI) network,and sub-modules to investigate taurine-induced changes in gene expression in human HSCs(LX-2). Subsequently, all of the differentially expressed genes(DEGs) were subjected to gene ontology function and Kyoto encyclopedia of genes and genomes pathway enrichment analysis. Furthermore, the interactions of DEGs were explored in a human PPI network, and sub-modules of the DEGs interaction network were analyzed using Cytoscape software.RESULTS A total of 635 DEGs were identified in taurine-treated HSCs when compared with the controls. Of these, 304 genes were statistically significantly up-regulated, and 331 down-regulated. Most of these DEGs were mainly located on the membrane and extracellular region, and are involved in the biological processes of signal transduction, cell proliferation, positive regulation of extracellular regulated protein kinases 1(ERK1) and ERK2 cascade, extrinsic apoptotic signaling pathway and so on. Fifteen significantly enriched pathways with DEGs were identified, including mitogen-activated protein kinase(MAPK) signaling pathway, peroxisome proliferators-activated receptor signaling pathway,estrogen signaling pathway, Th1 and Th2 cell differentiation, cyclic adenosine monophosphate signaling pathway and so on. By integrating the transcriptomics and human PPI data, nine critical genes, including MMP2, MMP9, MMP21,TIMP3, KLF10, CX3CR1, TGFB1, VEGFB, and EGF, were identified in the PPI network analysis.CONCLUSION Taurine promotes the apoptosis of HSCs via up-regulating TGFB1 and then activating the p38 MAPK-JNK-Caspase9/8/3 pathway. These findings enhance the understanding of the molecular mechanism of taurine-induced HSC apoptosis and provide references for liver disorder therapy.展开更多
AIM： To investigate the inhibitory effect of natural taurine （NTau） on portal hypertension （PHT） in rats with experimentally-induced liver cirrhosis （LC）. METHODS： Experimentally-induced LC Wistar rats （20 ra...AIM： To investigate the inhibitory effect of natural taurine （NTau） on portal hypertension （PHT） in rats with experimentally-induced liver cirrhosis （LC）. METHODS： Experimentally-induced LC Wistar rats （20 rats/group） were treated with either oral saline or oral NTau for 6 consecutive weeks. Evaluation parameters included portal venous pressure （PVP）, portal venous resistance （PVR）, portal venous flow （PVF）, splanchnic vascular resistance （SVR） and mean arterial pressure （NAP）. Vasoactive substance levels including nitric oxide （NO）, nitric oxide synthase （NOS） and cyclic guanosine monophosphate （cGMP） were also measured. Histological investigation of type Ⅰ and Ⅲ collagen （COL Ⅰ and Ⅲ） and transforming growth factor-β1 （TGF-β1） was also performed. RESULTS： Treatment with NTau （1） significantly decreased PVP, PVR and PVF, and increased MAP and SVP; （2） markedly increased the vascular compliance and reduced the zero-stress of the portal vein; （3） markedly decreased the amount of NO and cGMP and activity of NOS; and （4） improved the pathological status of the liver tissue and reduced the expression of COL Ⅰ, COL Ⅲ and TGF-β1. CONCLUSION： NTau inhibited the LC-induced PHT by improving hyperdynamic circulation, morphology of liver and biomechanical properties of the portal vein in experimentally-induced LC rats.展开更多
OBJECTIVE:To systematically review the efficacy and safety ofTraditional Chinese Medicine(TCM)interventions,compared with control interventions(placebo or conventional Western medical therapy),in the treatment of acqu...OBJECTIVE:To systematically review the efficacy and safety ofTraditional Chinese Medicine(TCM)interventions,compared with control interventions(placebo or conventional Western medical therapy),in the treatment of acquired immunodeficiency syndrome(AIDS).METHODS:Electronic databases including PubMed,the Cochrane Library,China National Knowledge Infrastructure(CNKI),and Wanfang Data were searched to identify relevant randomized controlled trials(RCTs)published as of May 2012.Studies were selected according to the specified inclusion and exclusion criteria and then subjected to methodological quality assessment,data extraction,and meta-analysis according to the Cochrane Handbook for Systematic Reviews of Interventions.RESULTS:Twelve RCTs involving 881 patients with AIDS were included.Methodological quality assessment showed that two were high-quality,two were moderate-quality,and eight were low-quality.Meta-analysis showed that TCM interventions were associated with significantly reduced plasma viral load compared with placebo[odds ratio OR=2.46,95%confidence interval CI(1.02,5.94);P=0.04].However,the reductions in plasma viral load significantly favored conventional Western medical therapy alone over integrated traditional Chinese and Western medical therapy[OR=0.16,95%CI(0.05,0.55);P=0.004].Patients receiving TCM interventions had significantly higher CD4+T lymphocyte counts compared with those on placebo[OR=2.54,95%CI(1.40,4.60);P=0.002].In addition,TCM interventions were significantly more likely to have improved clinical symptoms[OR=2.82,95%CI(1.85,4.31);P<0.00001].TCM interventions conferred a similar risk of adverse events(AEs)compared with control interventions[OR=1.87,95%CI(0.58,6.01);P=0.29].CONCLUSION:Current evidence suggests that TCM interventions are significantly more effective than placebo in reducing plasma viral load and increasing CD4+T lymphocyte count in patients with AIDS.When compared with conventional Western medical therapy,TCM interventions were significantly less effective in reducing plasma viral load,although they were associated with a higher percentage of patients with improved symptoms.Patients receiving TCM interventions did not seem to be at an increased risk of AEs.展开更多
Zeolites with ordered porous structure of molecular size are widely employed as commercial adsorbents and catalysts.On the other hand,the zeolite matrix is regarded as an ideal scaffold for hosting coordinatively unsa...Zeolites with ordered porous structure of molecular size are widely employed as commercial adsorbents and catalysts.On the other hand,the zeolite matrix is regarded as an ideal scaffold for hosting coordinatively unsaturated sites.Remarkable achievements have been made dealing with the construction,characterization and catalytic applications of coordinatively unsaturated sites in zeolite matrix.Herein,a literature overview of recent progresses on this important topic is presented from the specific view of coordination chemistry.Different strategies to construction coordinatively unsaturated sites in zeolite matrix,in zeolite framework or extraframework positions,are first introduced and their characteristics are compared.Then,spectroscopic techniques to determine the existing states of cation sites and their transformations in zeolite matrix are discussed.In the last section,the catalytic applications of coordinatively unsaturated sites in zeolite matrix for various important chemical transformations are summarized.展开更多
AIM： To investigate the effects of four different ingredients of zedoary （Curcuma aromatica oil, Curcumol, β-elemence, and Curcumin） on the gene expressions of hepatic stellate cells （HSCs）, and to explore the m...AIM： To investigate the effects of four different ingredients of zedoary （Curcuma aromatica oil, Curcumol, β-elemence, and Curcumin） on the gene expressions of hepatic stellate cells （HSCs）, and to explore the molecular mechanism of zedoary against hepatic fibrosis at gene network level. METHODS： We detected the mRNA sequences of 50 liver fibrosis-related genes in GenBank and designed oligonucleotide probes. We synthesized oligonucleotides with PE8909 DNA synthesizing instrument, and carried out oligonucleotide microarray with OGR-04 dropping instrument and aldehyded glass chip. Cultured HSC-T6 cells were breated wibh different concentrations of Colchicine, Curcuma aromatica oil, Curcumol, β-elemence, and Curcumin. According to the experiment of cell toxicity, we took the appropriate concentrations of medicines that resulted in over 50% of cell survival as experiment concentrations. We collected the cells at 1, 6, 12, and 24 h, and extracted total RNA with TRIzol reagent, then labeled cDNAs with Cy3-dUTP and Cy5-dUTP. These labeled cDNAs were hybridized to an oligonucleotide microarray which was washed several times and scanned by scanner GenePix 4000B. Different gene expressions of HSC-T6 cells were analyzed by ImaGene 4.2 software. RESULTS： After HSC-T6 cells were cultured in a medium containing 6.25μg/mL Colchicine for 12 h, expression of TIMP-1 decreased 2.2-folds. After HSC-T6 cells were cultured in a medium containing 78.125 μg/mL of Curcuma aromatica oil for 24 h, the expression of TIMP-2 and IL-6 decreased 2.3- and 2.2-folds, respectively. Moreover, after HSC-T6 cells were cultured in a medium containing 1.5625 μg/mL of Curcumol for 12 h, the expression of TGFμ1 and P450a decreased 2.3- and 2.1-folds, respectively. CONCLUSION： Our results may show the possible molecular mechanism of Curcuma aromatica oil and Curcumol against hepatic fibrosis.展开更多
AIM To develop a reliable and simple method to identify important biological metabolites and relevant pathways for taurine in hepatic stellate cells(HSCs), in order to provide more data for taurine therapy.METHODS All...AIM To develop a reliable and simple method to identify important biological metabolites and relevant pathways for taurine in hepatic stellate cells(HSCs), in order to provide more data for taurine therapy.METHODS All the biological samples were analyzed by using highperformance liquid chromatography-time electrospray ionization/quadrupole-time of flight mass spectrometry. Principal component analysis and partial least squares discriminant analysis were used to identify statistically different metabolites for taurine in HSCs, and metabolomic pathway analysis was used to do pathway analysis for taurine in HSCs. The chemical structure of the related metabolites and pathways was identified by comparing the m/z ratio and ion mode with the data obtained from free online databases.RESULTS A total of 32 significant differential endogenous metabolites were identified, which may be related to the mechanism of action of taurine in HSCs. Among the seven relevant pathways identified, sphingolipid metabolism pathway, glutathione metabolism pathway and thiamine metabolism pathway were found to be the most important metabolic pathways for taurine in HSCs.CONCLUSION This study showed that there were distinct changes in biological metabolites of taurine in HSCs and three differential metabolic pathways including sphingolipid pathway, glutathione pathway and thiamine metabolism pathway might be of key importance in mediating the mechanism of action of taurine in HSCs.展开更多
Machining,especially dry machining of titanium alloys,has been one of the most significant challenges for carbide cutting tools.In this study,aluminum-rich AlTiN coating,as well as TiAlSiN nanocomposite coating,were s...Machining,especially dry machining of titanium alloys,has been one of the most significant challenges for carbide cutting tools.In this study,aluminum-rich AlTiN coating,as well as TiAlSiN nanocomposite coating,were successfully employed for dry milling of Ti-6 A1-4 V alloy with high efficiency and long tool life.At the cutting speeds of 150 m/min and 200 m/min,the tool life of the TiAlSiN-coated tool exceeds that of AlTiN-coated tool by 32 and 66%,respectively.The wear modes for both coated tools include the uniform flank wear,smooth wear,chipping,coating and substrate flaking,crater and notch wear,and the wear mechanisms include adhesion,diffusion,oxidation and crack.Among them,the wear mechanism is dominated by the adhesion and oxidation wear.As compared with AlTiN coating,TiAlSiN coating exhibits better mechanical properties and oxidation resistance,which contribute to a better cutting performance,fewer thermal cracks and smaller and uniform workpiece chips during the dry milling of Ti-6 A1-4 V alloy.展开更多
Objective:To explore the core acupoints and combination rules of acupuncture therapy for postoperative urinary retention after hemorrhoidectomy,and,further to analyze the characteristics of the prescription of acupunc...Objective:To explore the core acupoints and combination rules of acupuncture therapy for postoperative urinary retention after hemorrhoidectomy,and,further to analyze the characteristics of the prescription of acupuncture therapy for postoperative urinary retention after hemorrhoidectomy.Methods:Relevant clinical studies in seven databases were searched systematically from database inception to 1 st October 2020.Based on data mining techniques,the core acupoints,characteristics and combination rules of acupuncture therapy for postoperative urinary retention after hemorrhoidectomy were analyzed comprehensively.Statistics collected and analysis of acupoint selection included the frequency of usage of acupoints,the meridian of acupoints,the location of acupoints and the combination of acupoints.Cluster and association analysis were performed utilizing Excel 13.0 and SPSS 26.0.Results:In the 36 studies included,the most frequently adopted acupoint was Sānyīnjiāo(三阴交 SP6);the most frequently adopted meridian was the foot-taiyin spleen meridian;the most frequently involved location was the lower limbs;and the most frequently adopted combination of acupoints was SP6 and Zhōngjí(中极CV 3).Cluster analysis showed that the acupoints could be divided into three categories:the first group comprised SP6 alone;the second group included CV3,Guānyuán(关元CV4),Yīnlíngquán(阴陵泉SP9) and Zúsānlǐ(足三里ST36);and the third group included Pángguāngshū(膀胱俞BL28),Chéngshān(承山BL57),Tàichōng(太冲LR3),Zhìbiān(秩边 BL54),Tàixī(太溪KI6),Hégǔ(合谷 LI4),Xuèhǎi(血海SP10),Qìhǎi(气海CV6) and Shǔidào(水道ST28).Conclusion:It was found that acupuncture therapy for postoperative urinary retention after hemorrhoidectomy mainly follows the four characteristic rules:the selection of acupoints following the meridian,selection of acupoints at local points,selection of acupoints at distal points and selection of acupoints according to special symptoms.展开更多
By using a rigid bulky carboxylic ligand a-cyanocinnamic acid(CCA),a dinuclear dysprosium(Ⅲ) complex [Dy_(2)(CCA)_(6)(MeOH)_(4)](1) was synthesized.Single crystal X-ray crystallography reveals that the two eight-coor...By using a rigid bulky carboxylic ligand a-cyanocinnamic acid(CCA),a dinuclear dysprosium(Ⅲ) complex [Dy_(2)(CCA)_(6)(MeOH)_(4)](1) was synthesized.Single crystal X-ray crystallography reveals that the two eight-coordinate dysprosium ions are bridged by four deprotonated carboxyl groups,forming a centrosymmetric paddle-wheel-1ike structure.Dynamic magnetic property measurements indicate that complex 1 displays field-induced slow magnetic relaxation.The temperature-dependent relaxation times can be fitted using Orbach and Raman processes with parameters of n=2.8(2),C=27(8) s^(-1)/K^(n),τ_(0)=5(2) × 10^(-10) s and U_(eff)=40(3) cm^(-1).Magnetic studies on the diamagnetic Y~Ⅲ-diluted analogue[Dy_(0.206)Y_(1.794)(CCA)_(6)(MeOH)_(4)](2) reveal its slow magnetic relaxation behavior without external dc field and the antiferromagnetic coupling between the Dy^(Ⅲ) ions in 1.Fits on the obtained relaxation times of 2lead to the parameters of n=4.5(3),C=0.7(2) s^(-1)/K^(n),τ_0=2.8(2) × 10^(-9) s and U_(eff)=38(2) cm^(-1).The results suggest that slow magnetic relaxation originates from the single-ion relaxation of Dy^(Ⅲ) ions.Moreover,the diamagnetic dilution can suppress other fast relaxation pathways at low temperature,on account of the elimination of magnetic coupling and dipolar interaction.Ab initio calculations were then performed on the single Dy^(Ⅲ) ion species {YDy} and indicate that the first excited Kramers doublets(KDs)lie at ca.76 cm^(-1),which is slightly higher than the experimental U_(eff) value.The intramolecular magnetic interactions were also calculated and indicate a weak ferromagnetic dipole-diploe magnetic interaction and an antiferromagnetic exchange coupling.展开更多
Our preliminary studies confirmed that an active principle region of Buyang Huanwu decoction, comprising alkaloid, polysaccharide, aglycon, glucoside and volatile oil, can induce bone marrow mesenchymal stem cell diff...Our preliminary studies confirmed that an active principle region of Buyang Huanwu decoction, comprising alkaloid, polysaccharide, aglycon, glucoside and volatile oil, can induce bone marrow mesenchymal stem cell differentiation into neurons. Mitogen-activated protein kinase signaling was identified as one of the key pathways underlying this differentiation process. The present study shows phosphorylated extracellular signal-regulated protein kinase and phosphorylated p38 protein expression was increased after differentiation. Cellular signaling pathway blocking agents, PD98059 and SB203580, inhibited extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways respectively, mRNA and protein expression of the neuronal marker, neuron specific enolase, and neural stem cell marker, nestin, were decreased in bone marrow mesenchymal stem cells after treatment with the active principle region of Buyang Huanwu decoction. Experimental findings indicate that, extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways participate in bone marrow mesenchymal stem cell differentiation into neuron-like cells, induced by the active principle region of Buyang Huanwu decoction.展开更多
With ificreasing demand for large cylindrical forgings, a new technology--electroslag remelting （ESR） for direct manufacture of hollow ingots rather than solid ingots has been developed. The main features of the pro...With ificreasing demand for large cylindrical forgings, a new technology--electroslag remelting （ESR） for direct manufacture of hollow ingots rather than solid ingots has been developed. The main features of the process include a T-shaped current supplying mould （CSM）, double power supply, an ingot withdrawing system, a metal level automatic control system based on a level sensor using the electromagnetic eddy current method, and the exchange of a consumable multi-electrode. ANSYS software was used to calculate the fluid flow and heat transfer in the slag bath 1 and metal pool of this ESR hollow ingot process with its T-shaped CSM. The mathematmal model was Verified by measuring the geometry of the liquid metal pool as observed in the macrostructure of 4650 mm （external diameter）/ 4450 mm （internal diameter） hollow ingots by sulphur print method： the. observed shape and depth of the s!ag bath were consistent with the simulated results. Simulation of the ESR process can improve understanding of the process and allow better operating parameters to be selected.展开更多
Sensitivity loop shaping using add-on peak filters is a simple and effective method to reject narrow-band disturbances in hard disk drive （HDD） servo systems. The parallel peak filter is introduced to provide high-g...Sensitivity loop shaping using add-on peak filters is a simple and effective method to reject narrow-band disturbances in hard disk drive （HDD） servo systems. The parallel peak filter is introduced to provide high-gain magnitude in the concerned frequency range of open-loop transfer function. Different from almost all the known peak filters that possess second-order structures, we explore in this paper bow high-order peak filters can be designed to improve the loop shaping performance. The main idea is to replace some of the constant coefficients of common second-order peak filter by frequency-related transfer functions, and then differential evolution （DE） algorithm is adopted to perform optimal design. We creatively introduce chromosome coding and fitness function design, which are original and the key steps that lead to the success of DE applications in control system design. In other words, DE is modified to achieve a novel design for hard disk drive control. Owing to the remarkable searching ability of DE, the expected shape of sensitivity function can be achieved by incorporating the resultant high-order peak filter in parallel with baseline feedback controller. As a result, a seventh-order peak filter is designed to compensate for contact-induced vibration in a high-density HDD servo system, where the benefits of high-order filter are clearly demonstrated.展开更多
文摘The selective activation of C-H bonds is pivotal in catalysis for converting hydrocarbons into value-added chemicals.Ethylbenzene dehydrogenation to styrene is crucial process to produce polystyrene and its derivatives used in synthetic materials.Herein,K-Cr@Y with zeolite-encaged isolated O=Cr(VI)=O species modified by extraframework potassium ions is constructed,showing remarkable performance in CO_(2)-promoted ethylbenzene dehydrogenation with initial ethylbenzene conversion of 66%and styrene selectivity of 96%,outperforming other M-Cr@Y catalysts(M=Li,Na,Rb,Cs).Extraframework potassium ions can modulate the electron density of zeolite-encaged Cr(VI)species and therefore facilitate C–H bond activation in ethylbenzene molecules.The gradual reduction of zeolite-encaged O=Cr(VI)=O to less active Cr(IV)=O species by dihydrogen during ethylbenzene dehydrogenation is evidenced by comprehensive characterization results,and Cr(IV)=O can be re-oxidized to O=Cr(VI)=O species upon simple calcination regeneration.The results from in situ DRIFT spectroscopy elucidate the critical promotion role of CO_(2)in ethylbenzene dehydrogenation over K-Cr@Y by retarding the over-reduction of zeolite-encaged Cr species to inactive Cr(III)species and suppressing coke deposition.This study advances the rational design of non-noble metal catalysts for CO_(2)-promoted ethylbenzene dehydrogenation with zeolite-encaged high valence transition metal ions modulated by extraframework cations.
基金the financial support from the National Key Research and Development Program of China(No.2023YFD1701100)the National Natural Science Foundation of China(No.32072450)+2 种基金the National Science Fund for Distinguished Young Scholars of Guangdong Province(No.2021B1515020107)the Opening Foundation of Hubei Key Laboratory of Novel Reactor and Green Chemical Technology(No.NRG202306)the Opening Foundation of Guangdong Province Key Laboratory of Microbial Signals and Disease Control(No.MSDC2023-19)。
文摘Plant bacterial diseases have infiicted substantial economic losses in global crop,fruit,and vegetable production.The conventional methods for managing these diseases typically rely on the application of antibiotics.However,these antibiotics often target the growth factors of the pathogenic bacteria,leading to the accumulation and emergence of drug-resistant strains,which exacerbates antibiotic resistance.Innovative methods are urgently needed to treat and prevent the toxicity caused by these pathogenic bacteria.Targeting virulence mechanisms in pathogens is a globally recognized and effective strategy for mitigating bacterial resistance.TypeⅢsecretion system(T3SS)serves as a crucial virulence determinant in Gram-negative pathogens,and its non-essentials for pathogen growth renders it an ideal target.Targeting the T3SS holds significant potential to alleviate selective pressure for resistance mutations in pathogens.Therefore,targeting T3SS in pathogenic bacteria,while preserving their growth,has emerged as a novel avenue for the development of antimicrobial drugs.In recent years,a multitude of small molecular inhibitors targeting T3SS have been identified.This article offers a comprehensive review of T3SS inhibitors in plant pathogens,while also presenting the latest research advancements in this research direction.
基金financially supported by the Science and Technology Project of Guangdong Province,China(Grant Nos.2017B090911006 and 2017B090913006)the Key Project of Basic Research and Applied Basic Research in Universities of Guangdong Province,China(Grant No.2018KZDXM043)+3 种基金the Jihua Laboratory Project“Additive Manufacturing for Difficulty-to-Machine Materials”(Grant No.X190061UZ190)the Heyuan Science and Technology Project(Grant No.HEKE 000781)the Young Innovative Talents Program of Universities in Guangdong Province(Grant No.2018KQNCX141)the Guangzhou Science and Technology Project(Grant No.202002030259)。
文摘WC–Co cemented carbides, well-known as the conventional tooling materials, have not been successfully produced by one step additive manufacturing processes such as selective laser melting(SLM) yet. The microstructure evolution as well as WC grain growth behavior has rarely been investigated in detail during SLM process. In this study, the WC–Co cemented carbides with different Co contents(12–32 wt%) were prepared by optimized SLM processes for comparative investigation of densification behavior, microstructure characterization and mechanical property. The increase in Co content in feedstock carbide granules can improve the densification behavior during SLM process. The SLM processed WC-12 Co shows larger average WC grain size and higher percentage of coarser WC grains as compared with both WC-20 Co and WC-32 Co. The microstructure characterization, combined with finite element simulation, shows the WC grain growth mechanisms include agglomeration and dissolution-deposition of WC during SLM process and agglomeration of WC is an important mechanism especially for WC–Co cemented carbides with Co content as low as 12 wt%. The comparison between horizontal(perpendicular to the SLM laser beam) and vertical(parallel to the SLM laser beam) cross sections of carbides shows that SLM process introduces a certain degree of microstructure and mechanical behavior anisotropy for WC-12 Co, WC-20 Co, and WC-32 Co.
基金Supported by the National Natural Science Foundation of China,No.81174263National Science and Technology Major Project during the 12th Five-year Plan Period,No.2012ZX1005006+1 种基金Sanming Project of Medicine in Shenzhen,Guangdong Province,China,No.SZSM201612074and Science and Technology Planning Project of Guangdong Province,China,No.2017A020213016.
文摘BACKGROUND No guideline recommends antiviral therapy for hepatitis B e antigen(HBeAg)-positive chronic hepatitis B patients with persistently normal alanine aminotransferase levels and a high hepatitis B virus(HBV)DNA viral load.AIM To evaluate the feasibility and safety of a Chinese herbal formula as a therapeutic option for chronic HBV infection.METHODS In total,395 patients(30–65 years old)with confirmed HBeAg-positive chronic hepatitis B infection and persistently normal alanine aminotransferase were randomized to receive either Chinese herbal formula or placebo for 96 wk.Endpoints to evaluate therapeutic efficacy included:(1)HBV DNA levels decreased to less than 4 log10 IU/mL at weeks 48 and 96;and(2)HBeAg clearance and seroconversion rates at weeks 48 and 96.RESULTS HBV DNA levels≤4 log10 IU/mL were 10.05%at week 48 and 18.59%at week 96 in the treatment group.The HBeAg clearance and conversion rates were 8.54%and 8.04%at week 48 and 16.08%and 14.57%at week 96,respectively.However,HBV DNA levels≤4 log10 IU/mL were 2.55%and 2.55%at weeks 48 and 96,respectively,and the HBeAg clearance rates were 3.06%and 5.61%at weeks 48 and 96,respectively,in the control group.The quantitative hepatitis B surface antigen and HBeAg levels at baseline and changes during the treatment period as well as the alanine aminotransferase elevation at weeks 12 and 24 were strong predictors of HBeAg clearance.CONCLUSION High rates of HBV DNA reduction,HBeAg clearance and seroconversion could be achieved with Chinese herbal formula treatments,and the treatments were relatively safe for HBeAg-positive chronic hepatitis B-infected patients with persistently normal alanine aminotransferase.The ability of the compound to modulate host immune function probably contributed to this effect.
基金the National Natural Science Foundation of China,No.81360595 and No.81860790Guangxi Natural Science Foundation Program,No.KJT13066+2 种基金the Bagui Scholars Foundation Program of Guangxithe Special-term Experts Foundation Program of Guangxithe Project of Guangxi Young Teacher Fundamental Ability Promotion,No.2017KY0298
文摘BACKGROUND Studies show that the antifibrotic mechanism of taurine may involve its inhibition of the activation and proliferation of hepatic stellate cells(HSCs). Since the molecular mechanism of taurine-mediated antifibrotic activity has not been fully unveiled and is little studied, it is imperative to use "omics" methods to systematically investigate the molecular mechanism by which taurine inhibits liver fibrosis.AIM To establish a network including transcriptomic and protein-protein interaction data to elucidate the molecular mechanism of taurine-induced HSC apoptosis.METHODS We used microarrays, bioinformatics, protein-protein interaction(PPI) network,and sub-modules to investigate taurine-induced changes in gene expression in human HSCs(LX-2). Subsequently, all of the differentially expressed genes(DEGs) were subjected to gene ontology function and Kyoto encyclopedia of genes and genomes pathway enrichment analysis. Furthermore, the interactions of DEGs were explored in a human PPI network, and sub-modules of the DEGs interaction network were analyzed using Cytoscape software.RESULTS A total of 635 DEGs were identified in taurine-treated HSCs when compared with the controls. Of these, 304 genes were statistically significantly up-regulated, and 331 down-regulated. Most of these DEGs were mainly located on the membrane and extracellular region, and are involved in the biological processes of signal transduction, cell proliferation, positive regulation of extracellular regulated protein kinases 1(ERK1) and ERK2 cascade, extrinsic apoptotic signaling pathway and so on. Fifteen significantly enriched pathways with DEGs were identified, including mitogen-activated protein kinase(MAPK) signaling pathway, peroxisome proliferators-activated receptor signaling pathway,estrogen signaling pathway, Th1 and Th2 cell differentiation, cyclic adenosine monophosphate signaling pathway and so on. By integrating the transcriptomics and human PPI data, nine critical genes, including MMP2, MMP9, MMP21,TIMP3, KLF10, CX3CR1, TGFB1, VEGFB, and EGF, were identified in the PPI network analysis.CONCLUSION Taurine promotes the apoptosis of HSCs via up-regulating TGFB1 and then activating the p38 MAPK-JNK-Caspase9/8/3 pathway. These findings enhance the understanding of the molecular mechanism of taurine-induced HSC apoptosis and provide references for liver disorder therapy.
基金Supported by The National Natural Science Foundation of China,Grant,No.30660235Guangxi Science Foundation forYouths,Grant,No.0728080National"11th 5-year"Support Plan of China,Grant,No.2006BAI0802-07
文摘AIM： To investigate the inhibitory effect of natural taurine （NTau） on portal hypertension （PHT） in rats with experimentally-induced liver cirrhosis （LC）. METHODS： Experimentally-induced LC Wistar rats （20 rats/group） were treated with either oral saline or oral NTau for 6 consecutive weeks. Evaluation parameters included portal venous pressure （PVP）, portal venous resistance （PVR）, portal venous flow （PVF）, splanchnic vascular resistance （SVR） and mean arterial pressure （NAP）. Vasoactive substance levels including nitric oxide （NO）, nitric oxide synthase （NOS） and cyclic guanosine monophosphate （cGMP） were also measured. Histological investigation of type Ⅰ and Ⅲ collagen （COL Ⅰ and Ⅲ） and transforming growth factor-β1 （TGF-β1） was also performed. RESULTS： Treatment with NTau （1） significantly decreased PVP, PVR and PVF, and increased MAP and SVP; （2） markedly increased the vascular compliance and reduced the zero-stress of the portal vein; （3） markedly decreased the amount of NO and cGMP and activity of NOS; and （4） improved the pathological status of the liver tissue and reduced the expression of COL Ⅰ, COL Ⅲ and TGF-β1. CONCLUSION： NTau inhibited the LC-induced PHT by improving hyperdynamic circulation, morphology of liver and biomechanical properties of the portal vein in experimentally-induced LC rats.
基金Supported by International Cooperation Project,the Ministry of Science and Technology of the People's Republic of China(S2013ZR0063)Guangxi Key Technologies R&D Program(No.1298003-1-1,11107009-1-3)+2 种基金Guangxi Natural Science Foundation(No.0832016Z)China Postdoctoral Science Foundation(Post Doctor of China Central South Uni-versity 2013M531816)Guangxi Administration of Traditional Chinese Medicine(GZKZ-G1105,GZKZ10-054,2012032)
文摘OBJECTIVE:To systematically review the efficacy and safety ofTraditional Chinese Medicine(TCM)interventions,compared with control interventions(placebo or conventional Western medical therapy),in the treatment of acquired immunodeficiency syndrome(AIDS).METHODS:Electronic databases including PubMed,the Cochrane Library,China National Knowledge Infrastructure(CNKI),and Wanfang Data were searched to identify relevant randomized controlled trials(RCTs)published as of May 2012.Studies were selected according to the specified inclusion and exclusion criteria and then subjected to methodological quality assessment,data extraction,and meta-analysis according to the Cochrane Handbook for Systematic Reviews of Interventions.RESULTS:Twelve RCTs involving 881 patients with AIDS were included.Methodological quality assessment showed that two were high-quality,two were moderate-quality,and eight were low-quality.Meta-analysis showed that TCM interventions were associated with significantly reduced plasma viral load compared with placebo[odds ratio OR=2.46,95%confidence interval CI(1.02,5.94);P=0.04].However,the reductions in plasma viral load significantly favored conventional Western medical therapy alone over integrated traditional Chinese and Western medical therapy[OR=0.16,95%CI(0.05,0.55);P=0.004].Patients receiving TCM interventions had significantly higher CD4+T lymphocyte counts compared with those on placebo[OR=2.54,95%CI(1.40,4.60);P=0.002].In addition,TCM interventions were significantly more likely to have improved clinical symptoms[OR=2.82,95%CI(1.85,4.31);P<0.00001].TCM interventions conferred a similar risk of adverse events(AEs)compared with control interventions[OR=1.87,95%CI(0.58,6.01);P=0.29].CONCLUSION:Current evidence suggests that TCM interventions are significantly more effective than placebo in reducing plasma viral load and increasing CD4+T lymphocyte count in patients with AIDS.When compared with conventional Western medical therapy,TCM interventions were significantly less effective in reducing plasma viral load,although they were associated with a higher percentage of patients with improved symptoms.Patients receiving TCM interventions did not seem to be at an increased risk of AEs.
基金supported by the National Natural Science Fundation of China(21722303,21421001)the Municipal Natural Science Fund of Tianjin(18JCJQJC47400,18JCZDJC37400)111 Project(B12015,B18030)~~
文摘Zeolites with ordered porous structure of molecular size are widely employed as commercial adsorbents and catalysts.On the other hand,the zeolite matrix is regarded as an ideal scaffold for hosting coordinatively unsaturated sites.Remarkable achievements have been made dealing with the construction,characterization and catalytic applications of coordinatively unsaturated sites in zeolite matrix.Herein,a literature overview of recent progresses on this important topic is presented from the specific view of coordination chemistry.Different strategies to construction coordinatively unsaturated sites in zeolite matrix,in zeolite framework or extraframework positions,are first introduced and their characteristics are compared.Then,spectroscopic techniques to determine the existing states of cation sites and their transformations in zeolite matrix are discussed.In the last section,the catalytic applications of coordinatively unsaturated sites in zeolite matrix for various important chemical transformations are summarized.
基金Supported by Guandong Traditional Chinese Medicine Bureau No.102135 and Shenzhen Technology Bureau No.200204187,
文摘AIM： To investigate the effects of four different ingredients of zedoary （Curcuma aromatica oil, Curcumol, β-elemence, and Curcumin） on the gene expressions of hepatic stellate cells （HSCs）, and to explore the molecular mechanism of zedoary against hepatic fibrosis at gene network level. METHODS： We detected the mRNA sequences of 50 liver fibrosis-related genes in GenBank and designed oligonucleotide probes. We synthesized oligonucleotides with PE8909 DNA synthesizing instrument, and carried out oligonucleotide microarray with OGR-04 dropping instrument and aldehyded glass chip. Cultured HSC-T6 cells were breated wibh different concentrations of Colchicine, Curcuma aromatica oil, Curcumol, β-elemence, and Curcumin. According to the experiment of cell toxicity, we took the appropriate concentrations of medicines that resulted in over 50% of cell survival as experiment concentrations. We collected the cells at 1, 6, 12, and 24 h, and extracted total RNA with TRIzol reagent, then labeled cDNAs with Cy3-dUTP and Cy5-dUTP. These labeled cDNAs were hybridized to an oligonucleotide microarray which was washed several times and scanned by scanner GenePix 4000B. Different gene expressions of HSC-T6 cells were analyzed by ImaGene 4.2 software. RESULTS： After HSC-T6 cells were cultured in a medium containing 6.25μg/mL Colchicine for 12 h, expression of TIMP-1 decreased 2.2-folds. After HSC-T6 cells were cultured in a medium containing 78.125 μg/mL of Curcuma aromatica oil for 24 h, the expression of TIMP-2 and IL-6 decreased 2.3- and 2.2-folds, respectively. Moreover, after HSC-T6 cells were cultured in a medium containing 1.5625 μg/mL of Curcumol for 12 h, the expression of TGFμ1 and P450a decreased 2.3- and 2.1-folds, respectively. CONCLUSION： Our results may show the possible molecular mechanism of Curcuma aromatica oil and Curcumol against hepatic fibrosis.
基金Supported by National Natural Science Foundation of China,No.81360595 and No.81360532Guangxi Natural Science Foundation Program,No.2014GXNSFDA118027+1 种基金Bagui Scholars Foundation Program of GuangxiSpecial-term Experts Foundation Program of Guangxi
文摘AIM To develop a reliable and simple method to identify important biological metabolites and relevant pathways for taurine in hepatic stellate cells(HSCs), in order to provide more data for taurine therapy.METHODS All the biological samples were analyzed by using highperformance liquid chromatography-time electrospray ionization/quadrupole-time of flight mass spectrometry. Principal component analysis and partial least squares discriminant analysis were used to identify statistically different metabolites for taurine in HSCs, and metabolomic pathway analysis was used to do pathway analysis for taurine in HSCs. The chemical structure of the related metabolites and pathways was identified by comparing the m/z ratio and ion mode with the data obtained from free online databases.RESULTS A total of 32 significant differential endogenous metabolites were identified, which may be related to the mechanism of action of taurine in HSCs. Among the seven relevant pathways identified, sphingolipid metabolism pathway, glutathione metabolism pathway and thiamine metabolism pathway were found to be the most important metabolic pathways for taurine in HSCs.CONCLUSION This study showed that there were distinct changes in biological metabolites of taurine in HSCs and three differential metabolic pathways including sphingolipid pathway, glutathione pathway and thiamine metabolism pathway might be of key importance in mediating the mechanism of action of taurine in HSCs.
基金financially supported by the Science and Technology Planning Project of Guangdong Province, China (Grant No. 2017B090911006)the Science and Technology Project of Heyuan City, Guangdong (Grant No. HEKE000781).
文摘Machining,especially dry machining of titanium alloys,has been one of the most significant challenges for carbide cutting tools.In this study,aluminum-rich AlTiN coating,as well as TiAlSiN nanocomposite coating,were successfully employed for dry milling of Ti-6 A1-4 V alloy with high efficiency and long tool life.At the cutting speeds of 150 m/min and 200 m/min,the tool life of the TiAlSiN-coated tool exceeds that of AlTiN-coated tool by 32 and 66%,respectively.The wear modes for both coated tools include the uniform flank wear,smooth wear,chipping,coating and substrate flaking,crater and notch wear,and the wear mechanisms include adhesion,diffusion,oxidation and crack.Among them,the wear mechanism is dominated by the adhesion and oxidation wear.As compared with AlTiN coating,TiAlSiN coating exhibits better mechanical properties and oxidation resistance,which contribute to a better cutting performance,fewer thermal cracks and smaller and uniform workpiece chips during the dry milling of Ti-6 A1-4 V alloy.
文摘Objective:To explore the core acupoints and combination rules of acupuncture therapy for postoperative urinary retention after hemorrhoidectomy,and,further to analyze the characteristics of the prescription of acupuncture therapy for postoperative urinary retention after hemorrhoidectomy.Methods:Relevant clinical studies in seven databases were searched systematically from database inception to 1 st October 2020.Based on data mining techniques,the core acupoints,characteristics and combination rules of acupuncture therapy for postoperative urinary retention after hemorrhoidectomy were analyzed comprehensively.Statistics collected and analysis of acupoint selection included the frequency of usage of acupoints,the meridian of acupoints,the location of acupoints and the combination of acupoints.Cluster and association analysis were performed utilizing Excel 13.0 and SPSS 26.0.Results:In the 36 studies included,the most frequently adopted acupoint was Sānyīnjiāo(三阴交 SP6);the most frequently adopted meridian was the foot-taiyin spleen meridian;the most frequently involved location was the lower limbs;and the most frequently adopted combination of acupoints was SP6 and Zhōngjí(中极CV 3).Cluster analysis showed that the acupoints could be divided into three categories:the first group comprised SP6 alone;the second group included CV3,Guānyuán(关元CV4),Yīnlíngquán(阴陵泉SP9) and Zúsānlǐ(足三里ST36);and the third group included Pángguāngshū(膀胱俞BL28),Chéngshān(承山BL57),Tàichōng(太冲LR3),Zhìbiān(秩边 BL54),Tàixī(太溪KI6),Hégǔ(合谷 LI4),Xuèhǎi(血海SP10),Qìhǎi(气海CV6) and Shǔidào(水道ST28).Conclusion:It was found that acupuncture therapy for postoperative urinary retention after hemorrhoidectomy mainly follows the four characteristic rules:the selection of acupoints following the meridian,selection of acupoints at local points,selection of acupoints at distal points and selection of acupoints according to special symptoms.
基金Project supported by the National Natural Science Foundation of China (21805048,22005069)the Natural Science Foundation of Guangdong Province (2022A1515011145,2023A1515010602)+2 种基金the Science and Technology Research Project of Guangzhou (202102080023,202201020166)the Project for Key Areas of Ordinary Colleges and Universities of Guangdong Province(2022ZDZX4035)the "Climbing Program" Special Funds of Guangdong Province (pdjh 2023b0389)。
文摘By using a rigid bulky carboxylic ligand a-cyanocinnamic acid(CCA),a dinuclear dysprosium(Ⅲ) complex [Dy_(2)(CCA)_(6)(MeOH)_(4)](1) was synthesized.Single crystal X-ray crystallography reveals that the two eight-coordinate dysprosium ions are bridged by four deprotonated carboxyl groups,forming a centrosymmetric paddle-wheel-1ike structure.Dynamic magnetic property measurements indicate that complex 1 displays field-induced slow magnetic relaxation.The temperature-dependent relaxation times can be fitted using Orbach and Raman processes with parameters of n=2.8(2),C=27(8) s^(-1)/K^(n),τ_(0)=5(2) × 10^(-10) s and U_(eff)=40(3) cm^(-1).Magnetic studies on the diamagnetic Y~Ⅲ-diluted analogue[Dy_(0.206)Y_(1.794)(CCA)_(6)(MeOH)_(4)](2) reveal its slow magnetic relaxation behavior without external dc field and the antiferromagnetic coupling between the Dy^(Ⅲ) ions in 1.Fits on the obtained relaxation times of 2lead to the parameters of n=4.5(3),C=0.7(2) s^(-1)/K^(n),τ_0=2.8(2) × 10^(-9) s and U_(eff)=38(2) cm^(-1).The results suggest that slow magnetic relaxation originates from the single-ion relaxation of Dy^(Ⅲ) ions.Moreover,the diamagnetic dilution can suppress other fast relaxation pathways at low temperature,on account of the elimination of magnetic coupling and dipolar interaction.Ab initio calculations were then performed on the single Dy^(Ⅲ) ion species {YDy} and indicate that the first excited Kramers doublets(KDs)lie at ca.76 cm^(-1),which is slightly higher than the experimental U_(eff) value.The intramolecular magnetic interactions were also calculated and indicate a weak ferromagnetic dipole-diploe magnetic interaction and an antiferromagnetic exchange coupling.
基金sponsored by the National Natural Science Foundation of China,No.81102595the Natural Science Foundation of Guangxi,No.2012GXNSFAA053113
文摘Our preliminary studies confirmed that an active principle region of Buyang Huanwu decoction, comprising alkaloid, polysaccharide, aglycon, glucoside and volatile oil, can induce bone marrow mesenchymal stem cell differentiation into neurons. Mitogen-activated protein kinase signaling was identified as one of the key pathways underlying this differentiation process. The present study shows phosphorylated extracellular signal-regulated protein kinase and phosphorylated p38 protein expression was increased after differentiation. Cellular signaling pathway blocking agents, PD98059 and SB203580, inhibited extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways respectively, mRNA and protein expression of the neuronal marker, neuron specific enolase, and neural stem cell marker, nestin, were decreased in bone marrow mesenchymal stem cells after treatment with the active principle region of Buyang Huanwu decoction. Experimental findings indicate that, extracellular signal-regulated protein kinase and p38 in mitogen-activated protein kinase signaling pathways participate in bone marrow mesenchymal stem cell differentiation into neuron-like cells, induced by the active principle region of Buyang Huanwu decoction.
基金Item Sponsored by National Natural Science Foundation of China(51204041)National High Technology Research and Development Program(863 Program) of China(2012AA03A502)+1 种基金Fundamental Research Funds for the Central Universities of China(N130402016)Program for Liaoning's Innovative Research Team in University of China(LT20120008)
文摘With ificreasing demand for large cylindrical forgings, a new technology--electroslag remelting （ESR） for direct manufacture of hollow ingots rather than solid ingots has been developed. The main features of the process include a T-shaped current supplying mould （CSM）, double power supply, an ingot withdrawing system, a metal level automatic control system based on a level sensor using the electromagnetic eddy current method, and the exchange of a consumable multi-electrode. ANSYS software was used to calculate the fluid flow and heat transfer in the slag bath 1 and metal pool of this ESR hollow ingot process with its T-shaped CSM. The mathematmal model was Verified by measuring the geometry of the liquid metal pool as observed in the macrostructure of 4650 mm （external diameter）/ 4450 mm （internal diameter） hollow ingots by sulphur print method： the. observed shape and depth of the s!ag bath were consistent with the simulated results. Simulation of the ESR process can improve understanding of the process and allow better operating parameters to be selected.
基金supported by National Natural Science Foundation of China(Nos.61640310 and 61433011)
文摘Sensitivity loop shaping using add-on peak filters is a simple and effective method to reject narrow-band disturbances in hard disk drive （HDD） servo systems. The parallel peak filter is introduced to provide high-gain magnitude in the concerned frequency range of open-loop transfer function. Different from almost all the known peak filters that possess second-order structures, we explore in this paper bow high-order peak filters can be designed to improve the loop shaping performance. The main idea is to replace some of the constant coefficients of common second-order peak filter by frequency-related transfer functions, and then differential evolution （DE） algorithm is adopted to perform optimal design. We creatively introduce chromosome coding and fitness function design, which are original and the key steps that lead to the success of DE applications in control system design. In other words, DE is modified to achieve a novel design for hard disk drive control. Owing to the remarkable searching ability of DE, the expected shape of sensitivity function can be achieved by incorporating the resultant high-order peak filter in parallel with baseline feedback controller. As a result, a seventh-order peak filter is designed to compensate for contact-induced vibration in a high-density HDD servo system, where the benefits of high-order filter are clearly demonstrated.
