Barley(Hordeum vulgare L.)ranks as the fourth most cultivated cereal crop globally by planting area.Kernel characteristics,including grain length,grain width,and thousand-grain weight(TGW),are essential determinants o...Barley(Hordeum vulgare L.)ranks as the fourth most cultivated cereal crop globally by planting area.Kernel characteristics,including grain length,grain width,and thousand-grain weight(TGW),are essential determinants of barley yield and quality.The identification and cloning of genes related to kernel traits,along with the detection of superior alleles,are fundamental for marker-assisted selection in barley breeding.This study presents the cloning of HvGL7-2H from barley,based on the known rice GL7 gene.The functional significance of HvGL7-2H in grain length was confirmed through ethyl methane sulfonate(EMS)mutants of the barley landrace“Hatiexi”.A candidate gene-based association analysis was conducted using a panel of 363 barley accessions to identify superior haplotypes for HvGL7-2H.The analysis revealed that Hap3 represented the superior haplotype for both grain length and TGW,while Hap4 emerged as the superior haplotype for TGW.These findings indicate that genotypes carrying the superior allele serve as valuable genetic resources,and the molecular markers identified herein will facilitate grain size and yield improvement in barley breeding programs.展开更多
The co-adsorption behaviors of SO2 and H2 O on face-centered cubic Cu（100） ideal surface were studied using the GGA-r PBE method of density functional theory（DFT） with slab models. The optimized structures of sing...The co-adsorption behaviors of SO2 and H2 O on face-centered cubic Cu（100） ideal surface were studied using the GGA-r PBE method of density functional theory（DFT） with slab models. The optimized structures of single H2 O and SO2 on Cu（100） surface were calculated at the coverage of 0.25 ML（molecular layer） and 0.5 ML. The results show that there was no obvious chemical adsorption of them on Cu（100） surface. The adsorbed structures, adsorption energy and electronic properties including difference charge density, valence charge density, Bader charge analysis and partial density of states（PDOS） of co-adsorbed structures of H2 O and SO2 were investigated to illustrate the interaction between adsorbates and surface. H2 O and SO2 can adsorb on surface of Cu atoms chemically via molecule form at the coverage of 0.25 ML, while H2 O dissociated into OH adsorbed on surface and H bonded with SO2 which keeps away from surface at the coverage of 0.5 ML.展开更多
The Fekete-Szego inequality for a subclass H(α,λ,A,B) of the class H of normalized analytic functions is studied.For each f(z)=z+~∞∑_(n=2)αnz^n ∈ H(α,λ,A,B),the sharp upper bounds of |α_3-α_2~2|for any compl...The Fekete-Szego inequality for a subclass H(α,λ,A,B) of the class H of normalized analytic functions is studied.For each f(z)=z+~∞∑_(n=2)αnz^n ∈ H(α,λ,A,B),the sharp upper bounds of |α_3-α_2~2|for any complex parameter u are obtained by using the fundamental inequalities of analytic functions and analytical techniques and the applications of the inequality of functions defined with Hadaniard product are proved.展开更多
Chromone and flavone are both central backbones of natural products and clinical medicines.Synthesis of diversely functionalized chromones and flavones constitutes significant research contents of the modern synthetic...Chromone and flavone are both central backbones of natural products and clinical medicines.Synthesis of diversely functionalized chromones and flavones constitutes significant research contents of the modern synthetic science because abundant molecular libraries of such types are crucial in providing candidate compounds for the discovery of new pharmaceuticals and functional materials.The direct C—H bond activation or functionalization on these heterocyclic backbones provides highly powerful tools for the rapid accesses to densely functionalized chromone and flavone derivatives.Considering the importance of the functionalized chromone and flavone compounds as well as the notable advances in the synthesis of such products by direct C—H activation or functionalization,we review herein the research advances in the C—H bond activation and functionalization reactions of chro mone and flavones,in hope of showing the current states and promise of the research domain.展开更多
AIM: To study the effect of Haimiding on the functioning of red cell membrane of FC and H22 tumor-bearing mice. METHODS: The membrane fluidity of red cells is measured with DPH fluorescence probe as a marker; the amou...AIM: To study the effect of Haimiding on the functioning of red cell membrane of FC and H22 tumor-bearing mice. METHODS: The membrane fluidity of red cells is measured with DPH fluorescence probe as a marker; the amount of red cell membrane proteins is measured using polyacrylamide gel electrophoresis; the amount of sialic acid (SA) on the surface of red cell membrane and the scalability of these cells are measured using colorimetric analysis. RESULTS: Haimiding can lower the membrane fluidity of red cells in tumor-bearing mice and the amount of their membrane proteins, while increasing the amount of sialic acid in the membrane of red cells in these mice and enhancing the ability of the membrane of their red cells to reseal. CONCLUSION: The anti-tumor effect of Haimiding on tumor-bearing mice is due to its ability to improve and restore the functions of the membrane of their red cell and to enhance the immune effect of the organisms.展开更多
New classes of functions namely (V, ρ)_(h,φ)-type I, quasi (V, ρ)_(h,φ)-type I and pseudo (V, ρ)_(h,φ)-type I functions are defined for multiobjective programming problem by using BenTal's generalized algebr...New classes of functions namely (V, ρ)_(h,φ)-type I, quasi (V, ρ)_(h,φ)-type I and pseudo (V, ρ)_(h,φ)-type I functions are defined for multiobjective programming problem by using BenTal's generalized algebraic operation. The examples of (V, ρ)_(h,φ)-type I functions are given. The sufficient optimality conditions are obtained for multi-objective programming problem involving above new generalized convexity.展开更多
The photo-/electrocatalytic functionalization of quinoxalin-2(1H)-ones has emerged as a promising and powerful approach for post-synthetic modification of quinoxalin-2(1H)-ones.This review provides an overview of rece...The photo-/electrocatalytic functionalization of quinoxalin-2(1H)-ones has emerged as a promising and powerful approach for post-synthetic modification of quinoxalin-2(1H)-ones.This review provides an overview of recent developments in photo-/electrocatalytic functionalization of quinoxalin-2(1H)-ones including arylation,alkylation,fluoroalkylation,amination,phosphorylation,acylation,alkoxylation,thiolation,silylation,and annulation.The reaction scope and the related mechanism are also well discussed.展开更多
This paper is concerned with the non-fragile H∞ filter design problem for uncertain discrete-time Takagi-Sugeno （T-S） fuzzy systems with time delay. To begin with, the T-S fuzzy system is transformed to an equivale...This paper is concerned with the non-fragile H∞ filter design problem for uncertain discrete-time Takagi-Sugeno （T-S） fuzzy systems with time delay. To begin with, the T-S fuzzy system is transformed to an equivalent switching fuzzy system. Then, based on the piecewise Lyapunov function and matrix decoupling technique, a new delay-dependent non-fragile H∞ filtering method is proposed for the switching fuzzy system. The proposed condition is less conservative than the previous results. Since only a set of LMIs is involved, the filter parameters can be solved directly. Finally, a design example is provided to illustrate the validity of the proposed method.展开更多
Unnatural a-amino acids have been extensively used in the modern drug discovery and protein engineering studies. They have also found applications in the development of chiral molecular catalysts and the total synthes...Unnatural a-amino acids have been extensively used in the modern drug discovery and protein engineering studies. They have also found applications in the development of chiral molecular catalysts and the total synthesis of diverse natural products. Accordingly the development of cost-effective approaches for the preparation of unnatural a-amino acids has received increasing attentions. Among all the available methods for this purpose, direct C–H functionalization of simple amino acids represents one of the most attractive approaches because it exhibits good atom-economy and step-efficiency. In particular, selective functionalization of either the primary or secondary C（sp^3）–H bonds in the amino acids has been explored to make versatile C–C, C–N, C–O, C–B and C–F bonds to modify the side chain of amino acids and even peptides. The present review surveys the recent advances of synthesis of chiral unnatural a-amino acids and peptides through palladium-catalyzed functionalization of un-activated C（sp^3）–H bonds.展开更多
Graphene-based materials are promising for hydrogen production and storage. In this work, using density functional theory calculations, we explored how a hydroxyl group influences H2 dissociation on graphene. Presence...Graphene-based materials are promising for hydrogen production and storage. In this work, using density functional theory calculations, we explored how a hydroxyl group influences H2 dissociation on graphene. Presence of the hydroxyl group makes the binding of H atom with graphene stronger, as the binding energy of H atom with the hydroxyl-modified graphene is higher than that with the pristine graphene. The para-site is the most favorable site for H2 dissociation on both the pristine and hydroxyl-modified graphene. The energy barrier of H2 dissociation at para-site on the pristine graphene is 3.10 eV whereas that on the hydroxyl-modified graphene is 2.46 eV, indicating a more facile H2 dissociation on the hydroxyl-modified graphene.展开更多
Different materials,such as metal sulphides,are often combined with metal‐organic frameworks(MOFs)to develop multi‐functional composites and improve their photocatalytic properties.However,the high interfacial energ...Different materials,such as metal sulphides,are often combined with metal‐organic frameworks(MOFs)to develop multi‐functional composites and improve their photocatalytic properties.However,the high interfacial energy barrier limits the formation and nano‐assembly of the heterogeneous junctions between MOFs and metal sulphides.Herein,the heterostructured Zr‐MOF‐S@CdS are successfully constructed through a sequential synthesis method,in which the mesoporous Zr‐MOF are firstly decorated with thioglycolic acid through pore functionalization,and followed by the S^(2-)anion exchange process resulting in the surface close attached growth of CdS onto Zr‐MOF‐S materials.Due to the presence of molecules linkers,the CdS can be precisely decorated onto Zr‐MOF‐S without aggregation,which can provide more active sites.Moreover,the intimate connections and the suitable band structures between two materials can also facilitate the photogenerated electron‐hole pairs separation.Therefore,the resulting Zr‐MOF‐S@CdS with appropriate ratio exhibits high photocatalytic activity for water reduction,in which the H_(2) evolution rate can reach up to 1861.7μmol·g^(‒1)·h^(‒1),4.5 times higher than pure CdS and 2.3 times higher than of Zr‐MOF/CdS,respectively.Considering the promising future of MOF‐based photocatalysts,this work may provide an avenue for the further design and synthesis MOF‐based composite photocatalysts for efficient H_(2) evolution.展开更多
6H-SiC is an important semiconductor material. The 6H-SiC wafer is always exposed to a high-humidity environment and the effect from the absorbed water molecule and some relative adsorbates is not negligible. Here, th...6H-SiC is an important semiconductor material. The 6H-SiC wafer is always exposed to a high-humidity environment and the effect from the absorbed water molecule and some relative adsorbates is not negligible. Here, the oxygen and water molecules absorbed on the 6H-SiC(0001) surface and the dissociation process were studied with density functional theory. On the 6H-SiC(0001) surface, absorbed O2 is spontaneously dissociated into O*, which is absorbed on a hollow site, and further transforms the 6H-SiC(0001) surface into SiO2. The absorbed H2O is spontaneously broken into OH*and H*, which are both absorbed on the top of the Si atom, and OH* is further reversibly transformed into O* and H*. The H* could saturate the dangling Si bond and change the absorption type of O*, which could stabilize the 6H-SiC(0001) surface and prevent it from transforming into SiO2.展开更多
Objective:This study was designed to observe the effect of electroacupuncture at Hégǔ(合谷L14),or Hòuxī(后溪SI3) or Wàiguān(外关TE5) acupoints on the function of the brain regions of a healthy human,...Objective:This study was designed to observe the effect of electroacupuncture at Hégǔ(合谷L14),or Hòuxī(后溪SI3) or Wàiguān(外关TE5) acupoints on the function of the brain regions of a healthy human,and to explore the neural information mechanism of a specific connection between LI4 and the facialoral area from the point of view of the brain function connection network.A further objective was to enrich knowledge of the specific connection between the body surface and the meridian route,and the specificity of acupoint effects.Methods:A total of 30 healthy volunteers were randomly assigned to LI4,SI3,and TE5 groups.The members of each group were stimulated with electroacupuncture,and their heads were scanned using fMRI.DPARSFA 2.4 and REST 1.8 software were used for data preprocessing and statistical analysis.The paired t-test was used within group and the double sample t-test was used for two-group comparisons.Results:In healthy people,left LI4 with electroacupuncture mainly caused a decrease of the functional connection of the right orofacial motor area of the brain,which remained decreased after removing the needle.When LI4 was compared with SI3 and TE5,LI4 caused a more significant decline in the functional connection of the right side of the brain during acupuncture.Conclusions:Acupuncture at LI4 has a significant effect on the function of the face-and mouth-related areas in the brain,and there is a continuous effect.It is suggested that LI4 and the face and mouth have a specific relationship in the brain,which is most obvious during acupuncture.展开更多
Biodiesel is an attractive alternative to fossil fuels due to the energy and environmental concerns. In this paper, seven different multi –SO_(3)H functionalized ILs based on the low-cost less-substituted amines, whi...Biodiesel is an attractive alternative to fossil fuels due to the energy and environmental concerns. In this paper, seven different multi –SO_(3)H functionalized ILs based on the low-cost less-substituted amines, which contained massive sites for functionalization of sulfonic acid groups and further treatment of sulfonate-based anions, were prepared as catalysts with high acidity and desirable catalytic activity for the synthesis of biodiesel from the esterification of oleic acid with methanol. The physicochemical properties of these acidic ILs were characterized by a variety of analytical techniques such as FT-IR, EA, TGA, and the Br?nsted acidity was well determined by UV–vis. Among the ILs prepared, [EDA-PS][P-TSA] showed the highest catalytic activity for esterification due to its high acidity and appropriate miscibility with reactants, with an ultrahigh97.58% conversion of oleic acid under the optimum conditions(i.e. reaction time, 1.8 h;catalyst amount, 3 wt%;alcohol/acid molar ratio, 13:1,temperature 70℃) acquired from the Box–Behnken response surface methodology. With the novel strategy of multi –SO_(3) H modification on ILs,our catalyst had an approaching or even superior oleic acid conversion rate compared to other reported catalysts with considerably lower catalyst dosage and shorter reaction time. More importantly, it also exhibited high generality for converting various FFA feedstocks into biodiesel with considerable conversion within 93.59–94.33% under a rather lower catalyst dosage, which showed the valuable potential for converting low-cost oils into biodiesel from an economic and environmental perspective.展开更多
AIM:To investigate the pathophysiology of functional heartburn(FH) in Japanese patients.METHODS:A total of 111 patients with proton pump inhibitor(PPI)-refractory non-erosive gastroesophageal reflux disease underwent ...AIM:To investigate the pathophysiology of functional heartburn(FH) in Japanese patients.METHODS:A total of 111 patients with proton pump inhibitor(PPI)-refractory non-erosive gastroesophageal reflux disease underwent intraesophageal pressure testing and 24-h multichannel intraluminal impedancep H(24MII-p H) testing.The patients also completed several questionnaires while they were receiving the PPI treatment, including the questionnaire for the diagnosis of reflux disease(QUEST), the frequency scale for the symptoms of gastroesophageal reflux disease(FSSG), the gastrointestinal symptoms rating scale(GSRS), SF-36, and the Cornell Medical Index(CMI).The subjects were classified into FH and endoscopy-negative reflux disease(ENRD) groups based on the Rome Ⅲ criteria.RESULTS:Thirty-three patients with esophageal motility disorder were excluded from this study, while 22 patients with abnormal esophageal acid exposure time(p H-POS) and 34 with hypersensitive esophagus(HE) were included in the ENRD group.The FH group included 22 patients with no reflux involvement.Sex, age, and body mass index did not differ significantly between the groups.The mean SF-36 values were < 50(normal) for all scales in these groups, with no significant differences.The GSRS scores in these groups were not different and showed overlap with other gastrointestinal symptoms.The QUEST and the FSSG scores did not differ significantly between the groups.Neuroticism was diagnosed using the CMI questionnaire in 17 of the 78 included subjects within the p H-POS(n=4),HE(n=8),and FH(n=5)groups,with no significant differences.CONCLUSION:Clinical characteristics of the FH and PPI-refractory ENRD groups were similar.Therefore,esophageal function should be examined via manometry and 24MII-p H testing to differentiate between them.展开更多
Let R0,n be the real Clifford algebra generated by e1, e2,... , en satisfying eiej＋ejei=-2δij,i,j=1,2…,ne0 is the unit element.Let Ω be an open set. A function f is called left generalized analytic in ft if f sati...Let R0,n be the real Clifford algebra generated by e1, e2,... , en satisfying eiej＋ejei=-2δij,i,j=1,2…,ne0 is the unit element.Let Ω be an open set. A function f is called left generalized analytic in ft if f satisfies the equation Lf=0,where ……qi 〉0, i =-, 1, - ……, n. In this article, we first give the kernel function for the generalized analytic function. Further, the Hilbert boundary value problem for generalized analytic functions in Rn＋1 will be investigated.展开更多
Saccharomycopsis ferment filtrate (SFF), mainly used in skin care products, has been reported to inhibit inflammatory nitric oxide production and prevent epidermal damage. However, the effects of SFF on epidermal kera...Saccharomycopsis ferment filtrate (SFF), mainly used in skin care products, has been reported to inhibit inflammatory nitric oxide production and prevent epidermal damage. However, the effects of SFF on epidermal keratinocytes have not yet been explored. We investigated the effects of SFF on skin barrier function using human primary epidermal keratinocytes. Cell viability was determined by MTT assay. The mRNA and protein expression levels of tight junction proteins (claudin-1, -3, -4, occludin, ZO-1) were analyzed by RT-PCR and Western blotting, respectively. The effect of SFF on the barrier formation of epidermal keratinocytes was measured by transepithelial electrical resistance (TER). Rescue of cell death from H2O2 treatment was evaluated by annexin V staining. SFF, at concentrations that did not cause significant change of cell viability, induced dose-dependent cell-cell adhesion and formation of an organized monolayer structure. Pretreatment of keratinocytes with EGTA, a Ca2+ chelator, did not inhibit the cell-cell adhesion of keratinocytes by SFF, indicating a Ca2+-independent mechanism. The mRNA and protein levels of claudin-1 in keratinocytes were up-regulated by SFF treatment in a dose-dependent manner. The expressions of other tight junctions (TJs) including claudin-3 & 4, occludin and ZO-1 were also similarly increased in SFF-treated epidermal keratinocytes. The promoting effect of SFF on the barrier function of epidermal keratinocytes was further confirmed by the increased TER value in SFF-treated epidermal keratinocytes. Annexin V staining confirmed that SFF markedly decreased the number of dead cells resulted from H2O2 injury. Taken together, our results provided the first evidence that SFF enhanced keratinocytes barrier function by increasing the expression of TJs and TER.展开更多
基金financially supported by the National Natural Science Foundation of China(31771774)the National Key Research and Development Program of China(2018YFD1000700 and 2018YFD1000706)+1 种基金the Young Top-notch Talent Cultivation Program of Hubei Province,Hubei Hongshan Laboratory,Chinathe China Agriculture Research System of Ministry of Agriculture and Rural Affairs(CARS-05).
文摘Barley(Hordeum vulgare L.)ranks as the fourth most cultivated cereal crop globally by planting area.Kernel characteristics,including grain length,grain width,and thousand-grain weight(TGW),are essential determinants of barley yield and quality.The identification and cloning of genes related to kernel traits,along with the detection of superior alleles,are fundamental for marker-assisted selection in barley breeding.This study presents the cloning of HvGL7-2H from barley,based on the known rice GL7 gene.The functional significance of HvGL7-2H in grain length was confirmed through ethyl methane sulfonate(EMS)mutants of the barley landrace“Hatiexi”.A candidate gene-based association analysis was conducted using a panel of 363 barley accessions to identify superior haplotypes for HvGL7-2H.The analysis revealed that Hap3 represented the superior haplotype for both grain length and TGW,while Hap4 emerged as the superior haplotype for TGW.These findings indicate that genotypes carrying the superior allele serve as valuable genetic resources,and the molecular markers identified herein will facilitate grain size and yield improvement in barley breeding programs.
基金Project(51222106)supported by the National Natural Science Foundation of ChinaProject(230201306500002)supported by the Fundamental Research Funds for the Central Universities+1 种基金ChinaProject(2014CB643300)supported by National Basic Research Program of China
文摘The co-adsorption behaviors of SO2 and H2 O on face-centered cubic Cu（100） ideal surface were studied using the GGA-r PBE method of density functional theory（DFT） with slab models. The optimized structures of single H2 O and SO2 on Cu（100） surface were calculated at the coverage of 0.25 ML（molecular layer） and 0.5 ML. The results show that there was no obvious chemical adsorption of them on Cu（100） surface. The adsorbed structures, adsorption energy and electronic properties including difference charge density, valence charge density, Bader charge analysis and partial density of states（PDOS） of co-adsorbed structures of H2 O and SO2 were investigated to illustrate the interaction between adsorbates and surface. H2 O and SO2 can adsorb on surface of Cu atoms chemically via molecule form at the coverage of 0.25 ML, while H2 O dissociated into OH adsorbed on surface and H bonded with SO2 which keeps away from surface at the coverage of 0.5 ML.
基金Supported by the Natural Science Foundation of Department of Education of Anhui Province（KJ2015A372）
文摘The Fekete-Szego inequality for a subclass H(α,λ,A,B) of the class H of normalized analytic functions is studied.For each f(z)=z+~∞∑_(n=2)αnz^n ∈ H(α,λ,A,B),the sharp upper bounds of |α_3-α_2~2|for any complex parameter u are obtained by using the fundamental inequalities of analytic functions and analytical techniques and the applications of the inequality of functions defined with Hadaniard product are proved.
基金National Natural Science Foundation of China(Nos.21861019 and 21702091)for financial support。
文摘Chromone and flavone are both central backbones of natural products and clinical medicines.Synthesis of diversely functionalized chromones and flavones constitutes significant research contents of the modern synthetic science because abundant molecular libraries of such types are crucial in providing candidate compounds for the discovery of new pharmaceuticals and functional materials.The direct C—H bond activation or functionalization on these heterocyclic backbones provides highly powerful tools for the rapid accesses to densely functionalized chromone and flavone derivatives.Considering the importance of the functionalized chromone and flavone compounds as well as the notable advances in the synthesis of such products by direct C—H activation or functionalization,we review herein the research advances in the C—H bond activation and functionalization reactions of chro mone and flavones,in hope of showing the current states and promise of the research domain.
基金Supported by National Science Foundation of China (No. 30271598,30300284)Heilongjiang Science Foundation (No. ZJY03-04)Ministry of Information Industry (No. 01XK230002)Heilongjiang Department of Education (Major Project No. 9551z006)Innovative Fund for Distinguished University and College Teachers of Heilongjiang Province, No. 2001015
文摘AIM: To study the effect of Haimiding on the functioning of red cell membrane of FC and H22 tumor-bearing mice. METHODS: The membrane fluidity of red cells is measured with DPH fluorescence probe as a marker; the amount of red cell membrane proteins is measured using polyacrylamide gel electrophoresis; the amount of sialic acid (SA) on the surface of red cell membrane and the scalability of these cells are measured using colorimetric analysis. RESULTS: Haimiding can lower the membrane fluidity of red cells in tumor-bearing mice and the amount of their membrane proteins, while increasing the amount of sialic acid in the membrane of red cells in these mice and enhancing the ability of the membrane of their red cells to reseal. CONCLUSION: The anti-tumor effect of Haimiding on tumor-bearing mice is due to its ability to improve and restore the functions of the membrane of their red cell and to enhance the immune effect of the organisms.
基金Supported by the NSF of Shaanxi Provincial Educational Department(06JK152)
文摘New classes of functions namely (V, ρ)_(h,φ)-type I, quasi (V, ρ)_(h,φ)-type I and pseudo (V, ρ)_(h,φ)-type I functions are defined for multiobjective programming problem by using BenTal's generalized algebraic operation. The examples of (V, ρ)_(h,φ)-type I functions are given. The sufficient optimality conditions are obtained for multi-objective programming problem involving above new generalized convexity.
文摘The photo-/electrocatalytic functionalization of quinoxalin-2(1H)-ones has emerged as a promising and powerful approach for post-synthetic modification of quinoxalin-2(1H)-ones.This review provides an overview of recent developments in photo-/electrocatalytic functionalization of quinoxalin-2(1H)-ones including arylation,alkylation,fluoroalkylation,amination,phosphorylation,acylation,alkoxylation,thiolation,silylation,and annulation.The reaction scope and the related mechanism are also well discussed.
基金supported by National Natural Science Foundation of China(No.60974139,No.60804021)Fundamental Research Funds for the Central Universities
文摘This paper is concerned with the non-fragile H∞ filter design problem for uncertain discrete-time Takagi-Sugeno （T-S） fuzzy systems with time delay. To begin with, the T-S fuzzy system is transformed to an equivalent switching fuzzy system. Then, based on the piecewise Lyapunov function and matrix decoupling technique, a new delay-dependent non-fragile H∞ filtering method is proposed for the switching fuzzy system. The proposed condition is less conservative than the previous results. Since only a set of LMIs is involved, the filter parameters can be solved directly. Finally, a design example is provided to illustrate the validity of the proposed method.
文摘Unnatural a-amino acids have been extensively used in the modern drug discovery and protein engineering studies. They have also found applications in the development of chiral molecular catalysts and the total synthesis of diverse natural products. Accordingly the development of cost-effective approaches for the preparation of unnatural a-amino acids has received increasing attentions. Among all the available methods for this purpose, direct C–H functionalization of simple amino acids represents one of the most attractive approaches because it exhibits good atom-economy and step-efficiency. In particular, selective functionalization of either the primary or secondary C（sp^3）–H bonds in the amino acids has been explored to make versatile C–C, C–N, C–O, C–B and C–F bonds to modify the side chain of amino acids and even peptides. The present review surveys the recent advances of synthesis of chiral unnatural a-amino acids and peptides through palladium-catalyzed functionalization of un-activated C（sp^3）–H bonds.
基金supported by the National High Technology Research and Development Program of China 863(2012AA022606)
文摘Graphene-based materials are promising for hydrogen production and storage. In this work, using density functional theory calculations, we explored how a hydroxyl group influences H2 dissociation on graphene. Presence of the hydroxyl group makes the binding of H atom with graphene stronger, as the binding energy of H atom with the hydroxyl-modified graphene is higher than that with the pristine graphene. The para-site is the most favorable site for H2 dissociation on both the pristine and hydroxyl-modified graphene. The energy barrier of H2 dissociation at para-site on the pristine graphene is 3.10 eV whereas that on the hydroxyl-modified graphene is 2.46 eV, indicating a more facile H2 dissociation on the hydroxyl-modified graphene.
文摘Different materials,such as metal sulphides,are often combined with metal‐organic frameworks(MOFs)to develop multi‐functional composites and improve their photocatalytic properties.However,the high interfacial energy barrier limits the formation and nano‐assembly of the heterogeneous junctions between MOFs and metal sulphides.Herein,the heterostructured Zr‐MOF‐S@CdS are successfully constructed through a sequential synthesis method,in which the mesoporous Zr‐MOF are firstly decorated with thioglycolic acid through pore functionalization,and followed by the S^(2-)anion exchange process resulting in the surface close attached growth of CdS onto Zr‐MOF‐S materials.Due to the presence of molecules linkers,the CdS can be precisely decorated onto Zr‐MOF‐S without aggregation,which can provide more active sites.Moreover,the intimate connections and the suitable band structures between two materials can also facilitate the photogenerated electron‐hole pairs separation.Therefore,the resulting Zr‐MOF‐S@CdS with appropriate ratio exhibits high photocatalytic activity for water reduction,in which the H_(2) evolution rate can reach up to 1861.7μmol·g^(‒1)·h^(‒1),4.5 times higher than pure CdS and 2.3 times higher than of Zr‐MOF/CdS,respectively.Considering the promising future of MOF‐based photocatalysts,this work may provide an avenue for the further design and synthesis MOF‐based composite photocatalysts for efficient H_(2) evolution.
基金supported by the Fundamental Research Project of Qinghai Province (2017-ZJ-795)
文摘6H-SiC is an important semiconductor material. The 6H-SiC wafer is always exposed to a high-humidity environment and the effect from the absorbed water molecule and some relative adsorbates is not negligible. Here, the oxygen and water molecules absorbed on the 6H-SiC(0001) surface and the dissociation process were studied with density functional theory. On the 6H-SiC(0001) surface, absorbed O2 is spontaneously dissociated into O*, which is absorbed on a hollow site, and further transforms the 6H-SiC(0001) surface into SiO2. The absorbed H2O is spontaneously broken into OH*and H*, which are both absorbed on the top of the Si atom, and OH* is further reversibly transformed into O* and H*. The H* could saturate the dangling Si bond and change the absorption type of O*, which could stabilize the 6H-SiC(0001) surface and prevent it from transforming into SiO2.
基金Supported by grants from National Key R&D Program of China:2019YFC1709001the National Natural Science Foundation of China:81973959+4 种基金8177443581674068the Foundation of Sichuan Provincial Administration of Traditional Chinese Medicine:2018JC007the Foundation of Chengdu University of Traditional Chinese Medicine:QNXZ2018034the National Program on Key Basic Research Project of China:2010CB530501.
文摘Objective:This study was designed to observe the effect of electroacupuncture at Hégǔ(合谷L14),or Hòuxī(后溪SI3) or Wàiguān(外关TE5) acupoints on the function of the brain regions of a healthy human,and to explore the neural information mechanism of a specific connection between LI4 and the facialoral area from the point of view of the brain function connection network.A further objective was to enrich knowledge of the specific connection between the body surface and the meridian route,and the specificity of acupoint effects.Methods:A total of 30 healthy volunteers were randomly assigned to LI4,SI3,and TE5 groups.The members of each group were stimulated with electroacupuncture,and their heads were scanned using fMRI.DPARSFA 2.4 and REST 1.8 software were used for data preprocessing and statistical analysis.The paired t-test was used within group and the double sample t-test was used for two-group comparisons.Results:In healthy people,left LI4 with electroacupuncture mainly caused a decrease of the functional connection of the right orofacial motor area of the brain,which remained decreased after removing the needle.When LI4 was compared with SI3 and TE5,LI4 caused a more significant decline in the functional connection of the right side of the brain during acupuncture.Conclusions:Acupuncture at LI4 has a significant effect on the function of the face-and mouth-related areas in the brain,and there is a continuous effect.It is suggested that LI4 and the face and mouth have a specific relationship in the brain,which is most obvious during acupuncture.
基金supporting by National Natural Science Foundation of China(Grant No.21878054)Project on the Integration of Industry and Education of Fujian Province(Project No.2018Y4008)。
文摘Biodiesel is an attractive alternative to fossil fuels due to the energy and environmental concerns. In this paper, seven different multi –SO_(3)H functionalized ILs based on the low-cost less-substituted amines, which contained massive sites for functionalization of sulfonic acid groups and further treatment of sulfonate-based anions, were prepared as catalysts with high acidity and desirable catalytic activity for the synthesis of biodiesel from the esterification of oleic acid with methanol. The physicochemical properties of these acidic ILs were characterized by a variety of analytical techniques such as FT-IR, EA, TGA, and the Br?nsted acidity was well determined by UV–vis. Among the ILs prepared, [EDA-PS][P-TSA] showed the highest catalytic activity for esterification due to its high acidity and appropriate miscibility with reactants, with an ultrahigh97.58% conversion of oleic acid under the optimum conditions(i.e. reaction time, 1.8 h;catalyst amount, 3 wt%;alcohol/acid molar ratio, 13:1,temperature 70℃) acquired from the Box–Behnken response surface methodology. With the novel strategy of multi –SO_(3) H modification on ILs,our catalyst had an approaching or even superior oleic acid conversion rate compared to other reported catalysts with considerably lower catalyst dosage and shorter reaction time. More importantly, it also exhibited high generality for converting various FFA feedstocks into biodiesel with considerable conversion within 93.59–94.33% under a rather lower catalyst dosage, which showed the valuable potential for converting low-cost oils into biodiesel from an economic and environmental perspective.
文摘AIM:To investigate the pathophysiology of functional heartburn(FH) in Japanese patients.METHODS:A total of 111 patients with proton pump inhibitor(PPI)-refractory non-erosive gastroesophageal reflux disease underwent intraesophageal pressure testing and 24-h multichannel intraluminal impedancep H(24MII-p H) testing.The patients also completed several questionnaires while they were receiving the PPI treatment, including the questionnaire for the diagnosis of reflux disease(QUEST), the frequency scale for the symptoms of gastroesophageal reflux disease(FSSG), the gastrointestinal symptoms rating scale(GSRS), SF-36, and the Cornell Medical Index(CMI).The subjects were classified into FH and endoscopy-negative reflux disease(ENRD) groups based on the Rome Ⅲ criteria.RESULTS:Thirty-three patients with esophageal motility disorder were excluded from this study, while 22 patients with abnormal esophageal acid exposure time(p H-POS) and 34 with hypersensitive esophagus(HE) were included in the ENRD group.The FH group included 22 patients with no reflux involvement.Sex, age, and body mass index did not differ significantly between the groups.The mean SF-36 values were < 50(normal) for all scales in these groups, with no significant differences.The GSRS scores in these groups were not different and showed overlap with other gastrointestinal symptoms.The QUEST and the FSSG scores did not differ significantly between the groups.Neuroticism was diagnosed using the CMI questionnaire in 17 of the 78 included subjects within the p H-POS(n=4),HE(n=8),and FH(n=5)groups,with no significant differences.CONCLUSION:Clinical characteristics of the FH and PPI-refractory ENRD groups were similar.Therefore,esophageal function should be examined via manometry and 24MII-p H testing to differentiate between them.
基金supported by NNSF of China (11171260)RFDP of Higher Education of China (20100141110054)Scientific Research Fund of Leshan Normal University (Z1265)
文摘Let R0,n be the real Clifford algebra generated by e1, e2,... , en satisfying eiej＋ejei=-2δij,i,j=1,2…,ne0 is the unit element.Let Ω be an open set. A function f is called left generalized analytic in ft if f satisfies the equation Lf=0,where ……qi 〉0, i =-, 1, - ……, n. In this article, we first give the kernel function for the generalized analytic function. Further, the Hilbert boundary value problem for generalized analytic functions in Rn＋1 will be investigated.
文摘Saccharomycopsis ferment filtrate (SFF), mainly used in skin care products, has been reported to inhibit inflammatory nitric oxide production and prevent epidermal damage. However, the effects of SFF on epidermal keratinocytes have not yet been explored. We investigated the effects of SFF on skin barrier function using human primary epidermal keratinocytes. Cell viability was determined by MTT assay. The mRNA and protein expression levels of tight junction proteins (claudin-1, -3, -4, occludin, ZO-1) were analyzed by RT-PCR and Western blotting, respectively. The effect of SFF on the barrier formation of epidermal keratinocytes was measured by transepithelial electrical resistance (TER). Rescue of cell death from H2O2 treatment was evaluated by annexin V staining. SFF, at concentrations that did not cause significant change of cell viability, induced dose-dependent cell-cell adhesion and formation of an organized monolayer structure. Pretreatment of keratinocytes with EGTA, a Ca2+ chelator, did not inhibit the cell-cell adhesion of keratinocytes by SFF, indicating a Ca2+-independent mechanism. The mRNA and protein levels of claudin-1 in keratinocytes were up-regulated by SFF treatment in a dose-dependent manner. The expressions of other tight junctions (TJs) including claudin-3 & 4, occludin and ZO-1 were also similarly increased in SFF-treated epidermal keratinocytes. The promoting effect of SFF on the barrier function of epidermal keratinocytes was further confirmed by the increased TER value in SFF-treated epidermal keratinocytes. Annexin V staining confirmed that SFF markedly decreased the number of dead cells resulted from H2O2 injury. Taken together, our results provided the first evidence that SFF enhanced keratinocytes barrier function by increasing the expression of TJs and TER.
