The SrTiO3 : Pr^3+ material, co-doped with monovalent Li^+ , divalent Mg^2+ , and trivalent Al^3+ was prepared by a new sol-gel method. The phase and crystallinity of the synthesized materials were investigated b...The SrTiO3 : Pr^3+ material, co-doped with monovalent Li^+ , divalent Mg^2+ , and trivalent Al^3+ was prepared by a new sol-gel method. The phase and crystallinity of the synthesized materials were investigated by powder X-ray diffraction(XRD) and scanning electron microcopy(SEM). Among the co-doped ion, Al^3+ incorporation caused the least lattice change and had the best crystallinity. Photoluminescence spectra were taken to investigate the luminescence characteristics. We observed a red luminescence change of SrTiO3 : Pr^3+ after being co-doped, and a best enhancement on the red luminescence with the trivalent Al^3+ was observed. The present results indicated that the charge defect associated with Al^3+ has led to charge compensation of Pr^+ and also implied that the charge defects(usually the second dopant ions replacing the A or B sites in the lattice) which are closer to PrSr^+ contribute more to the red luminescence enhancement.展开更多
Wave-induced seepage and its possible contribution to the formation of pockmarks in the Huanghe(Yellow) River delta were investigated experimentally and numerically. Laboratory experiments were carried out to explore ...Wave-induced seepage and its possible contribution to the formation of pockmarks in the Huanghe(Yellow) River delta were investigated experimentally and numerically. Laboratory experiments were carried out to explore the response of a layered silty seabed with various saturation conditions under cyclic wave loads,in which the pore pressure and seepage-related phenomena were particularly monitored. Numerical models to simulate wave-induced seepage in the seabed were presented and evaluated,then applied to the Huanghe River delta. The experimental results show that the excess pore pressure decreases more rapidly at the surface layer,while the seepage-related phenomena are more pronounced when large cyclic loads are applied and the underlying layer is less saturated. The proposed numerical models were verified by comparing with the experiments. The calculated seepage depth agreed well with the depth of the pockmarks in the Huanghe River delta. The experimental and numerical results and the existing insitu investigations indicate that the wave-induced seepage may be a direct cause of the pockmarks in the Huanghe River delta. Extreme storm waves and the dual-layered structure of hard surface layer and weak underlying layer are essential external and internal factors,respectively. Wave- or current-induced scour and transport are possible contributors to the reformation of pockmarks at a later stage.展开更多
A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NM...A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NMR, and mass spectroscopy (MS). The UV-vis absorption and photoluminescent properties of the complex were investigated.展开更多
Although progress in imaging and genetics allow for a noninvasive diagnosis of most cases of genetic iron overload, liver pathology remains often useful (1) to assess prognosis by grading fibrosis and seeking for as...Although progress in imaging and genetics allow for a noninvasive diagnosis of most cases of genetic iron overload, liver pathology remains often useful (1) to assess prognosis by grading fibrosis and seeking for associated lesions and (2) to guide the etiological diagnosis, especially when no molecular marker is available. Then, the type of liver siderosis (parenchymal, mesenchymal or mixed) and its distribution throughout the Iobule and the liver are useful means for suggesting its etiology: HLA-linked hemochromatosis gene (HFE) hemochromatosis or other rare genetic hemochromatosis, nonhemochromatotic genetic iron overload (ferroportin disease, aceruloplasminemia), or iron overload secondary to excessive iron supply, inflammatory syndrome, noncirrhotic chronic liver diseases including dysmetabolic iron overload syndrome, cirrhosis, and blood disorders.展开更多
Non-HFE hereditary haemochromatosis (HH) refers to a genetically heterogeneous group of iron overload disorders that are unlinked to mutations in the HFE gene. The four main types of non-HFE HH are caused by mutatio...Non-HFE hereditary haemochromatosis (HH) refers to a genetically heterogeneous group of iron overload disorders that are unlinked to mutations in the HFE gene. The four main types of non-HFE HH are caused by mutations in the hemojuvelin, hepcidin, transferrin receptor 2 and ferroportin genes. Juvenile haemochromatosis is an autosomal recessive disorder and can be caused by mutations in either hemojuvelin or hepcidin. Ar~ adult onset form of HH similar to HFE-HH is caused by homozygosity for mutations in transferrin receptor 2. The autosomal dominant iron overload disorder ferroportin disease is caused by mutations in the iron exporter ferroportin. The clinical characteristics and molecular basis of the various types of non-HFE haemochromatosis are reviewed. The study of these disorders and the molecules involved has been invaluable in improving our understanding of the mechanisms involved in the regulation of iron metabolism.展开更多
The left-right twin Higgs (LRTH) model predicts the existence of three additional Higgs bosons: one neutral Higgs φo and a pair of charged Higgs bosons φ±. In this paper, we study two pair production process...The left-right twin Higgs (LRTH) model predicts the existence of three additional Higgs bosons: one neutral Higgs φo and a pair of charged Higgs bosons φ±. In this paper, we study two pair production processes of these new particles at the next generation eγ colliders, i.e., e-γ → e-φ+φ- , and e-γ→vRφ-φ0. We find that the production cross section of the process e-γ → e-φ+φ- are at the level of several tens fb, the production cross section of the process e-γ→vRφ-φ0 can reach 0.35 fb with the reasonable parameter values. As long as the charged Higgs bosons are not too heavy, we conclude that these processes might be used to test for the left-right twin Higgs model in future high-energy linear collider experiments.展开更多
The chemical composition of essential oils obtained from Artemisia herba-alba and Mentha pulegium were determined. The essential oils were analyzed by gas chromatography coupled with mass spectrometry (GC/MS). Their...The chemical composition of essential oils obtained from Artemisia herba-alba and Mentha pulegium were determined. The essential oils were analyzed by gas chromatography coupled with mass spectrometry (GC/MS). Their antibacterial activity was studied in vitro against three standard strains: E. coli ATCC 25922, Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, and five clinical strains: Enterobacter cloacae, Staphylococcus aureus, Pseudomonas pyocyanique, Enterococcus faecium, and E. coli. Nineteen constituents were identified in A. herba-alba essential oil representing 99.57% of the total composition The major component was α-thujone (59.07%). The bacterial strains were inhibited at concentrations ranging from 1.25 μL/mL to 5μL/mL and killed at concentrations ranging from 1.25 μL/mL to 10 μL/mL. M. pulegium resulted in the identification of eighteen constituents representing 99.48% of the total composition. The main component was pulegone (78.07%). The minimal inhibitory (MIC) and bactericidal (MBC) concentrations were ranging from 1.25 μL/mL to 2.5 μL/mL.展开更多
The Higgs triplet model (HTM) predicts the existence of a pair of doubly charged Higgs bosons H±±. Single production of H±± via e7 collision at the next generation e+ e- International Linear Col...The Higgs triplet model (HTM) predicts the existence of a pair of doubly charged Higgs bosons H±±. Single production of H±± via e7 collision at the next generation e+ e- International Linear Collider (ILC) and the Large Hadron electron Collider (LHeC) is considered. The numerical results show that the production cross sections are very sensitive to the neutrino oscillation parameters. Their values for the inverted hierarchy mass spectrum are larger than those for the normal hierarchy mass spectrum at these two kinds of collider experiments. With reasonable values of the relevant free parameters, the possible signals of the doubly charged Higgs bosons predicted by the HTM might be detected in future ILC experiments.展开更多
Even though Tulbaghia violacea has been used to treat and manage epilepsy in South Africa by traditional medicine practitioners, no evidence in any literature has shown any scientific scrutiny of the effectiveness of ...Even though Tulbaghia violacea has been used to treat and manage epilepsy in South Africa by traditional medicine practitioners, no evidence in any literature has shown any scientific scrutiny of the effectiveness of the plant species in therapy. This study was intended, therefore, to investigate the anticonvulsant effect of the leaf methanol extract of Tulbaghia violacea by studying its effect against tonic convulsion induced by either PTZ (pentylenetetrazole), bicuculline, picrotoxin, strychnine or NMDLA (N-methyl-DL-aspartic acid) in mice. Qualitative phytochemical analysis, acute toxicity and HPLC studies were also carried out on the plant species. Leaf methanol extract of Tulbaghia violacea, phenobarbitone, diazepam or muscimol significantly antagonised PTZ, bicuculline or picrotoxin-induced convulsion. Combined treatment of sub-effective doses of T. violacea and muscimol significantly antagonised tonic convulsion induced by PTZ. T. violacea or phenobarbitone significantly antagonised strychnine-induced tonic convulsion. T. violacea or LY233053 significantly antagonised NMDLA-elicited tonic convulsion. Phenytoin or DMSO (dimethylsulfoxide) did not significantly affect the tonic convulsion produced by PTZ, bicuculline, picrotoxin, strychnine or NMDLA. The phytochemical qualitative analysis of the plant species showed the presence of alkaloids, saponins, reducing sugars, flavonoids, cardiac glycosides, triterpene steroids, quinones and tannins. The LD50 value obtained following oral administration of the plant extract was over 4000 mg/kg. The data in the present study indicate that the leaf methanol extract of T. violacea has anticonvulsant activity which is probably underpinned by GABAergic, glutaminergic and glycinergic mechanisms.展开更多
基金The Natural Science Foundation of Shaan'xi Province(2005F06)
文摘The SrTiO3 : Pr^3+ material, co-doped with monovalent Li^+ , divalent Mg^2+ , and trivalent Al^3+ was prepared by a new sol-gel method. The phase and crystallinity of the synthesized materials were investigated by powder X-ray diffraction(XRD) and scanning electron microcopy(SEM). Among the co-doped ion, Al^3+ incorporation caused the least lattice change and had the best crystallinity. Photoluminescence spectra were taken to investigate the luminescence characteristics. We observed a red luminescence change of SrTiO3 : Pr^3+ after being co-doped, and a best enhancement on the red luminescence with the trivalent Al^3+ was observed. The present results indicated that the charge defect associated with Al^3+ has led to charge compensation of Pr^+ and also implied that the charge defects(usually the second dopant ions replacing the A or B sites in the lattice) which are closer to PrSr^+ contribute more to the red luminescence enhancement.
基金Supported by the National Natural Science Foundation of China(No.41072216)the Science and Technology Development Program of Shandong Province(No.2014GGX104007)
文摘Wave-induced seepage and its possible contribution to the formation of pockmarks in the Huanghe(Yellow) River delta were investigated experimentally and numerically. Laboratory experiments were carried out to explore the response of a layered silty seabed with various saturation conditions under cyclic wave loads,in which the pore pressure and seepage-related phenomena were particularly monitored. Numerical models to simulate wave-induced seepage in the seabed were presented and evaluated,then applied to the Huanghe River delta. The experimental results show that the excess pore pressure decreases more rapidly at the surface layer,while the seepage-related phenomena are more pronounced when large cyclic loads are applied and the underlying layer is less saturated. The proposed numerical models were verified by comparing with the experiments. The calculated seepage depth agreed well with the depth of the pockmarks in the Huanghe River delta. The experimental and numerical results and the existing insitu investigations indicate that the wave-induced seepage may be a direct cause of the pockmarks in the Huanghe River delta. Extreme storm waves and the dual-layered structure of hard surface layer and weak underlying layer are essential external and internal factors,respectively. Wave- or current-induced scour and transport are possible contributors to the reformation of pockmarks at a later stage.
文摘A new cyclometalated iridium(III) complex with the formula [Ir(DPQ)2(acac)] (DPQ= 2,3-diphenylquinoxaline; acac=acetylacetone) was prepared. The structure of the complex was confirmed by Elemental Analysis (EA), 1H NMR, and mass spectroscopy (MS). The UV-vis absorption and photoluminescent properties of the complex were investigated.
文摘Although progress in imaging and genetics allow for a noninvasive diagnosis of most cases of genetic iron overload, liver pathology remains often useful (1) to assess prognosis by grading fibrosis and seeking for associated lesions and (2) to guide the etiological diagnosis, especially when no molecular marker is available. Then, the type of liver siderosis (parenchymal, mesenchymal or mixed) and its distribution throughout the Iobule and the liver are useful means for suggesting its etiology: HLA-linked hemochromatosis gene (HFE) hemochromatosis or other rare genetic hemochromatosis, nonhemochromatotic genetic iron overload (ferroportin disease, aceruloplasminemia), or iron overload secondary to excessive iron supply, inflammatory syndrome, noncirrhotic chronic liver diseases including dysmetabolic iron overload syndrome, cirrhosis, and blood disorders.
文摘Non-HFE hereditary haemochromatosis (HH) refers to a genetically heterogeneous group of iron overload disorders that are unlinked to mutations in the HFE gene. The four main types of non-HFE HH are caused by mutations in the hemojuvelin, hepcidin, transferrin receptor 2 and ferroportin genes. Juvenile haemochromatosis is an autosomal recessive disorder and can be caused by mutations in either hemojuvelin or hepcidin. Ar~ adult onset form of HH similar to HFE-HH is caused by homozygosity for mutations in transferrin receptor 2. The autosomal dominant iron overload disorder ferroportin disease is caused by mutations in the iron exporter ferroportin. The clinical characteristics and molecular basis of the various types of non-HFE haemochromatosis are reviewed. The study of these disorders and the molecules involved has been invaluable in improving our understanding of the mechanisms involved in the regulation of iron metabolism.
基金Supported in Part by the National Natural Science Foundation of China under Grant No.10775039 the Foundation of He'nan Educational Committee under Grant No.2009B140003
文摘The left-right twin Higgs (LRTH) model predicts the existence of three additional Higgs bosons: one neutral Higgs φo and a pair of charged Higgs bosons φ±. In this paper, we study two pair production processes of these new particles at the next generation eγ colliders, i.e., e-γ → e-φ+φ- , and e-γ→vRφ-φ0. We find that the production cross section of the process e-γ → e-φ+φ- are at the level of several tens fb, the production cross section of the process e-γ→vRφ-φ0 can reach 0.35 fb with the reasonable parameter values. As long as the charged Higgs bosons are not too heavy, we conclude that these processes might be used to test for the left-right twin Higgs model in future high-energy linear collider experiments.
文摘The chemical composition of essential oils obtained from Artemisia herba-alba and Mentha pulegium were determined. The essential oils were analyzed by gas chromatography coupled with mass spectrometry (GC/MS). Their antibacterial activity was studied in vitro against three standard strains: E. coli ATCC 25922, Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, and five clinical strains: Enterobacter cloacae, Staphylococcus aureus, Pseudomonas pyocyanique, Enterococcus faecium, and E. coli. Nineteen constituents were identified in A. herba-alba essential oil representing 99.57% of the total composition The major component was α-thujone (59.07%). The bacterial strains were inhibited at concentrations ranging from 1.25 μL/mL to 5μL/mL and killed at concentrations ranging from 1.25 μL/mL to 10 μL/mL. M. pulegium resulted in the identification of eighteen constituents representing 99.48% of the total composition. The main component was pulegone (78.07%). The minimal inhibitory (MIC) and bactericidal (MBC) concentrations were ranging from 1.25 μL/mL to 2.5 μL/mL.
基金Supported by the National Natural Science Foundation of China under Grant No.10975067the Specialized Research Fund for the Doctoral Program of Higher Education(SRFDP) under Grant No.200801650002
文摘The Higgs triplet model (HTM) predicts the existence of a pair of doubly charged Higgs bosons H±±. Single production of H±± via e7 collision at the next generation e+ e- International Linear Collider (ILC) and the Large Hadron electron Collider (LHeC) is considered. The numerical results show that the production cross sections are very sensitive to the neutrino oscillation parameters. Their values for the inverted hierarchy mass spectrum are larger than those for the normal hierarchy mass spectrum at these two kinds of collider experiments. With reasonable values of the relevant free parameters, the possible signals of the doubly charged Higgs bosons predicted by the HTM might be detected in future ILC experiments.
文摘Even though Tulbaghia violacea has been used to treat and manage epilepsy in South Africa by traditional medicine practitioners, no evidence in any literature has shown any scientific scrutiny of the effectiveness of the plant species in therapy. This study was intended, therefore, to investigate the anticonvulsant effect of the leaf methanol extract of Tulbaghia violacea by studying its effect against tonic convulsion induced by either PTZ (pentylenetetrazole), bicuculline, picrotoxin, strychnine or NMDLA (N-methyl-DL-aspartic acid) in mice. Qualitative phytochemical analysis, acute toxicity and HPLC studies were also carried out on the plant species. Leaf methanol extract of Tulbaghia violacea, phenobarbitone, diazepam or muscimol significantly antagonised PTZ, bicuculline or picrotoxin-induced convulsion. Combined treatment of sub-effective doses of T. violacea and muscimol significantly antagonised tonic convulsion induced by PTZ. T. violacea or phenobarbitone significantly antagonised strychnine-induced tonic convulsion. T. violacea or LY233053 significantly antagonised NMDLA-elicited tonic convulsion. Phenytoin or DMSO (dimethylsulfoxide) did not significantly affect the tonic convulsion produced by PTZ, bicuculline, picrotoxin, strychnine or NMDLA. The phytochemical qualitative analysis of the plant species showed the presence of alkaloids, saponins, reducing sugars, flavonoids, cardiac glycosides, triterpene steroids, quinones and tannins. The LD50 value obtained following oral administration of the plant extract was over 4000 mg/kg. The data in the present study indicate that the leaf methanol extract of T. violacea has anticonvulsant activity which is probably underpinned by GABAergic, glutaminergic and glycinergic mechanisms.