Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species dur...Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites,leading to uniform distribution of Ce cluster in the framework of Beta zeolites.Moreover,the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites,improving the utilization of Brønsted acid sites.In addition,Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites,which pave the way for its practical application in the production of alkylbenzene.展开更多
The conversion of acetone derived from biomass to isobutene has attracted extensive attentions.In comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a...The conversion of acetone derived from biomass to isobutene has attracted extensive attentions.In comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a higher isobutene selectivity.However,the catalyst stability remains a key problem for the long-running acetone conversion and the reasons for catalyst deactivation are poorly understood up to now.Herein,the deactivation mechanism of Lewis acidic Y/Beta catalyst during the acetone to isobutene conversion was investigated by various characterization techniques,including acetone-temperature-programmed surface reaction,gas chromatography-mass spectrometry,in situ ultraviolet-visible,and ^(13)C cross polarization magic angle spinning nuclear magnetic resonance spectroscopy.A successive aldol condensation and cyclization were observed as the main side-reactions during the acetone conversion at Lewis acidic Y sites.In comparison with the low reaction temperature,a rapid formation and accumulation of the larger cyclic unsaturated aldehydes/ketones and aromatics could be observed,and which could strongly adsorb on the Lewis acidic sites,and thus cause the catalyst deactivation eventually.After a simple calcination,the coke deposits could be easily removed and the catalytic activity could be well restored.展开更多
This study was carried out to assess the prevalence of resistance genes in strains of Escherichia coli and Salmonella spp. isolated from free-range chickens in Ouagadougou, where resistant bacteria can be transmitted ...This study was carried out to assess the prevalence of resistance genes in strains of Escherichia coli and Salmonella spp. isolated from free-range chickens in Ouagadougou, where resistant bacteria can be transmitted to humans via faeces or contaminated meat. A total of 280 strains of Escherichia coli and 129 strains of Salmonella spp. resistant to at least one beta-lactam or carbapenem antibiotic were used in this study. PCR analyses revealed the presence of ESBL (extended spectrum beta lactamase) resistance genes in Escherichia coli isolates, with 3.21% (9/280) possessing the CTX-M (Cefotaximase) gene, 15.35% (43/280) had the SHV (Sulfhydril Variable) gene, and 11.42% (32/280) had carbapenemase resistance genes, more specifically IMP (Imipenemase metallo-beta-lactamase). As regards Salmonella spp. strains, only the presence of the SHV (Sulfhydril Variable) gene was identified in 2.32% (3/129) of isolates belonging to the ESBL family, while 26.35% (34/129) and 13.95% (18/129) of isolates respectively possessed the IMP (Imipenemase metallo-beta-lactamase) and NDM (New Delhi metallo-β-lactamase) genes, both of the carbapenemase type. The significant prevalence of resistance genes in bacterial strains isolated from chickens sold outdoors in Ouagadougou raises major public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.展开更多
Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the ...Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the objective of this study was to assess the risk of cancer due to the ingestion of alpha and beta emitting radionuclides in the different types of water consumed in the region. A total of 63 water samples with 43 tap water samples, 5 bottled mineral water and 15 sachet water samples was collected and taken to GAEC laboratory for analysis. The low background Gas-less Automatic Alpha/Beta counting system (Canberra iMatic<sup>TM</sup>) was used to determine alpha and beta activity concentrations. Activity concentrations of both gross alpha and gross beta obtained in water sample were respectively lower than the WHO recommended limits of 0.1 Bq/l and 1 Bq/l. Also, the annual effective dose and total equivalent effective dose found in mineral bottled water samples were higher than in other types of water. The assessment of radiological lifetime risk has shown values of cancer risk due to ingestion alpha and beta emitters lower than recommended limit. These results indicate that there is no health hazard associated to consumption of water in the District of Abidjan.展开更多
Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the me...Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the metal salt solution during ion exchange influenced the ion exchange capacity of Fe, and resulted in different activities of the Fe-Beta catalyst. Fe-Beta catalysts with the Fe contents of (2.6, 6.3 and 9) wt% were synthesized using different amounts of 0.02 mol/L Fe salt solution. These catalysts were studied by various characterization techniques and their NH3-SCR activities were evaluated. The Fe-Beta catalyst with the Fe content of 6.3 wt% exhibited the highest activity, with a temperature range of 202-616℃ where the NOx conversion was 〉 80%. The Fe content in Beta zeolite did not influence the structure of Beta zeolite and valence state of Fe. Compared with the Fe-Beta catalysts with low Fe content (2.6 wt%), Fe-Beta catalysts with 6.3 wt% Fe content possessed more isolated Fe3. active sites which led to its higher NH3-SCR activity. A high capacity for NH3 and NO adsorption, and a high activity for NO oxidation also contributed to the high NH3-SCR activity of the Fe-Beta catalyst with 6.3 wt%. However, when the Fe content was further increased to 9.0 wt%, the amount of FexOy nanoparticles increased while the amount of isolated Fe3+ active sites was unchanged, which promoted NH3 oxidation and decreased the NH3-SCR activity at high temperature.展开更多
Zeolite Beta containing ultra-small CoO particles was synthesized from a one-step hydrothermal process. The synthesis route involves the pre-mixture of hydrofluoric acid with tetraethylammo- nium hydroxide (in a mola...Zeolite Beta containing ultra-small CoO particles was synthesized from a one-step hydrothermal process. The synthesis route involves the pre-mixture of hydrofluoric acid with tetraethylammo- nium hydroxide (in a molar ratio of 1.3-1.5:1) before the addition of a silicon and cobalt source.Investigations by scanning electron microscopy, X-ray diffraction, UV-Vi s spectroscopy, X-ray pho-toelectron spectroscopy, H 2 -temperature-programmed reduct i on and transmi ssi on el ectron mi -croscopy confirm the presence of ultra-small CoO particles in the zeolite Beta structure. The ul-tra-small CoO particles in zeolite Beta present high stability against both oxidation and reduction atmospheres at high temperatures. The catalytic performance of the CoO-containing zeolite Beta catalysts was compared with other Co-containing zeolites by evaluating ethylbenzene oxidation reactivity. The CoO-containing zeolite Beta exhibits high ethylbenzene conversion and high selectiv-ity to acetophenone and 1-phenylethanol. The high activity of this catalyst system can be attributed to the high dispersion of the ultra-small CoO particles in the Beta structure.展开更多
AIM: To investigate the expression of the transforming growth factor beta 1(TGF-beta 1) mRNA in different stages of alcoholic liver disease (ALD) and its clinical value. METHODS: One hundred and seven male alcoholics ...AIM: To investigate the expression of the transforming growth factor beta 1(TGF-beta 1) mRNA in different stages of alcoholic liver disease (ALD) and its clinical value. METHODS: One hundred and seven male alcoholics were grouped by clinical findings into four groups: alcohol abusers without liver impairment (n =22), alcoholic steatosis (n =30); alcoholic hepatitis (n=31); and alcoholic cirrhosis(n=24). Using peripheral blood mononuclear cells (PBMC) as samples the gene expression of TGF-beta 1 was examined quantitatively by reverse transcription polymerase chain reaction (RT-PCR) and dot blot. There are 34 healthy subjects served as control. RESULTS: The expression of TGF-beta 1 from all ALD patients was significantly greater than that in controls (1.320 +/- 1.162 vs 0.808 +/- 0.276, P【0.001). The differences of the expressions were significant between the patients from each groups (alcoholic steatosis, alcoholic hepatitis and alcoholic cirrhosis) and the controls (1.168 +/- 0.852, 1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.808 +/- 0.276, P【0.050). No significant differences of TGF -beta 1 mRNA expression were observed between alcohol abusers without liver impairment and controls. The expressions in patients with alcoholic hepatitis and alcoholic cirrhosis were significantly greater than that in alcohol abusers respectively (1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.841 +/- 0.706, P【0.050). No significant differences of TGF-beta 1 mRNA expression were observed between alcoholic fatty liver men and alcohol abusers. CONCLUSION: TGF-beta 1 expression level can be a risk factor for alcoholic liver disease and might be related to the inflammatory activity and fibrosis of the liver in patients.展开更多
Background: Ecologists are interested in assessing the spatial and temporal variation in ecological surveys repeated over time. This paper compares the 1985 and 2015 surveys of the Barro Colorado Forest Dynamics plot(...Background: Ecologists are interested in assessing the spatial and temporal variation in ecological surveys repeated over time. This paper compares the 1985 and 2015 surveys of the Barro Colorado Forest Dynamics plot(BCI), Panama,divided into 1250(20 m × 20 m) quadrats.Methods, spatial analysis: Total beta diversity was measured as the total variance of the Hellinger-transformed community data throughout the BCI plot. Total beta was partitioned into contributions of individual sites(LCBD indices), which were tested for significance and mapped.Results, spatial analysis: LCBD indices indicated the sites with exceptional community composition. In 1985,they were mostly found in the swamp habitat. In the 2015 survey, none of the swamp quadrats had significant LCBDs.What happened to the tree community in the interval?Methods, temporal analysis: The dissimilarity in community composition in each quadrat was measured between time 1(1985) and time 2(2015). Temporal Beta Indices(TBI) were computed from abundance and presence-absence data and tested for significance. TBI indices can be decomposed into B = species(or abundances-per-species) losses and C = species(or abundances-per-species) gains. B-C plots were produced; they display visually the relative importance of the loss and gain components, through time, across the sites.Results, temporal analysis: In BCI, quadrats with significant TBI indices were found in the swamp area, which is shrinking in importance due to changes to the local climate. A published habitat classification divided the BCI forest plot into six habitat zones. Graphs of the B and C components were produced for each habitat group. Group 4(the swamp) was dominated by species(and abundances-per-species) gains whereas the five other habitat groups were dominated by losses, some groups more than others.Conclusions: We identified the species that had changed the most in abundances in the swamp between T1 and T2.This analysis supported the hypothesis that the swamp is drying out and is invaded by species from the surrounding area. Analysis of the B and C components of temporal beta diversity bring us to the heart of the mechanisms of community change through time: losses(B) and gains(C) of species, losses and gains of individuals of various species. TBI analysis is especially interesting in species-rich communities where we cannot examine the changes in every species individually.展开更多
As an aging-associated degenerative disease,Alzheimer’s disease is characterized by the deposition of amyloid beta(Aβ),oxidative stress,inflammation,dysfunction and loss of cholinergic neurons.Colla Corii Asini(CCA)...As an aging-associated degenerative disease,Alzheimer’s disease is characterized by the deposition of amyloid beta(Aβ),oxidative stress,inflammation,dysfunction and loss of cholinergic neurons.Colla Corii Asini(CCA)is a traditional Chinese medicine which has been used for feebleness-related diseases and anti-aging.CCA might delay aging-induced degenerative changes in neurons.In the present study,we evaluated antioxidant activity,cytoprotective effects,and Aβremovability of enzyme-digested Colla Corii Asini(CCAD).Oxygen radical absorbance capacity(ORAC)activity assay showed that,as compared to gelatins from the skin of porcine,bovine and cold water fish,CCA exhibited the highest ORAC activity.The ORAC activity of CCA and CCAD was increased gradually by the length of time in storage.Ultrastructure analysis by scanning electron microscopy showed that among CCA manufactured in 2008,2013,2017 and gelatin from cold water fish skin,CCA manufactured in 2008 presented the smoothest surface structure.We further tested the protective effects of CCAD(manufactured in 2008)and enzyme-digested gelatin from cold water fish skin(FGD)on hydrogen peroxide(H2O2)-induced cell death in nerve growth factor-differentiated neuronal-like PC12 cells.Presto blue assay showed that both FGD and CCAD at 0.5 mg/m L increased cell viability in H2O2-treated neuronal-like PC12 cells.The protection of CCAD was significantly superior to that of FGD.Acetylcholinesterase(Ach E)assay showed that both FGD and CCAD inhibited Ach E activity in nerve growth factor-differentiated neuronal-like PC12 cells to 89.1%and 74.5%of that in non-treated cells,respectively.The data suggest that CCAD might be able to increase the neurotransmitter acetylcholine.Although CCAD inhibited Ach E activity in neuronal-like PC12 cells,CCAD prevented H2O2-induced abnormal deterioration of Ach E.ELISA and neprilysin activity assay results indicated that CCAD reduced amyloid beta accumulation and increased neprilysin activity in Aβ1–42-treated neuronal-like PC12 cells,suggesting that CCAD can enhance Aβclearance.Our results suggest that CCA might be useful for preventing and treating Alzheimer’s disease.展开更多
Objective To study the relationship between polymorphism of cystathionine beta synthase (CBS) gene and development of congenital heart disease (CHD). Methods One hundred and twenty-seven CHD case-parent triads wer...Objective To study the relationship between polymorphism of cystathionine beta synthase (CBS) gene and development of congenital heart disease (CHD). Methods One hundred and twenty-seven CHD case-parent triads were recruited from Liaoning Province as patient group, and 129 healthy subjects without family history of birth defect were simultaneously recruited as control group together with their biological parents. For all subjects the polymorphism of CBS gene G919A locus was examined by PCR-ARMS method, Results The frequencies of three genotypes (w/w, w/m, and m/m) in control group were 27.2%, 58,4%, and 14.4%, respectively, with no significant difference in gender. A significant difference in the allele frequency was found between CHD patients and controls, the wild allele frequency was 67,9% in patients and 55.7% in controls CHD parents' genotype distribution was significantly different from that in controls. Further comparison of each type of CHD showed that genotype frequencies in several CHD subtypes were significantly different from those in their corresponding controls. The results of TDT analysis showed that no allele transmission disequilibrium existed in CHD nuclear families. Conclusions CBS gene G919A mutation is associated with the development of CHD, and the mutated allele may decrease the risk of CHD.展开更多
e-related macular degeneration (AMD) causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests fr...e-related macular degeneration (AMD) causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer's-linked amyloid beta (Aβ) group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer's disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for latestage AMD.展开更多
AIM To investigate factors causing diabetes recurrence after sleeve gastrectomy(SG)and duodenal-jejunal bypass(DJB).METHODS SG and DJB were performed on rats with diabetes induced by high-fat diet(HFD)and streptozotoc...AIM To investigate factors causing diabetes recurrence after sleeve gastrectomy(SG)and duodenal-jejunal bypass(DJB).METHODS SG and DJB were performed on rats with diabetes induced by high-fat diet(HFD)and streptozotocin(STZ).HFD was used to induce diabetes recurrence at 4 wk postoperatively.Body weight,oral glucose tolerance test,homeostatic model assessment of insulin resistance(HOMA-IR),insulin signaling[IR,insulin receptor substrate(IRS 1,IRS2,phosphatidylinositol3-kinase and AKT in liver and skeletal muscle],oral glucose stimulated insulin secretion,beta-cell morphology(mass,apoptosis and insulin secretion),glucagon-like peptide(GLP)-1,PYY and ghrelin were compared among SG rats with common low-fat diet(SG-LFD),SG with HFD(SG-HFD),DJB rats with LFD(DJB-LFD),DJB with HFD(DJB-HFD)and shamoperation with LFD(Sham)at targeted postoperative times.RESULTS SG and DJB resulted in significant improvement in glucose tolerance,lower HOMA-IR,up-regulated hepatic and muscular insulin signaling,higher levels of oral glucose-stimulated insulin secretion,bigger betacell mass,higher immunofluorescence intensity of insulin,fewer transferase-mediated d UTP-biotin 3’nick end-labeling(TUNEL)-positive beta cells and higher postprandial GLP-1 and PYY levels than in the Sham group.The improvement in glucose tolerance was reversed at 12 wk postoperatively.Compared with the SG-LFD and DJB-LFD groups,the SG-HFD and DJB-HFD groups showed higher HOMA-IR,down-regulated hepatic and muscular insulin signaling,and more TUNEL-positive beta cells.No significant difference was detected between HFD and LFD groups for body weight,glucose-stimulated insulin secretion,betacell mass,immunofluorescence intensity of insulin,and postprandial GLP-1 and PYY levels.Fasting serum ghrelin decreased in SG groups,and there was no difference between HFD-SG and LFD-SG groups.CONCLUSION HFD reverses the improvement in glucose homeostasis after SG and DJB.Diabetes recurrence may correlate with re-impaired insulin sensitivity,but not with alterations of beta-cell function and body weight.展开更多
This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophil...This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophilia. The plasma level of β2GPI was measured by ELISA and Western blotting, and anti-β2GPI antibody by ELISA. Lupus anticoagulant (LA) was assayed using the dilute Russell viper venom time. Deficiency of the major natural anticoagulants including protein C (PC), protein S (PS), antithrombin (AT) and thrombomodulin (TM) was excluded from the proband. A mutation analysis was performed by amplification and sequencing of the APOH gene. Wild type and mutant (c.112A〉G) APOH expression plasmids were constructed and transfected into HEK293T cells. The results showed that the thrornbin generation capacity of the proband was higher than that of the other family members. Missense mutation p.Lys38Glu in APOH gene and LA coexisted in the proband. The mutation led to β2GPI deficiency and thrombosis by impairing the protein production and inhibiting the platelet aggregation. It was concluded that the recurrent thrombosis of the proband is associated with the coexistence ofp.Lys38Glu mutation in APOH gene and LA in plasma.展开更多
Objective To explore the association between the three polymorphisms [ C825T, C1429T and G(-350)A] of the gene encoding the G protein beta 3 subunit (GNB3) and hypertension by performing a case-control study in th...Objective To explore the association between the three polymorphisms [ C825T, C1429T and G(-350)A] of the gene encoding the G protein beta 3 subunit (GNB3) and hypertension by performing a case-control study in the northern Han Chinese population. Methods We recnaited 731 hypertensive patients and 673 control subjects (the calculated power value was 〉 0.8). Genotyping was performed to identify C825T, C1429T and G(-350)A polymorphisms using the TaqMan assay. Comparisons of allelic and genotypic frequencies between cases and controls were made by using the chi-square test. Logistic regression analyses were performed to investigate the relationships between the three polymorphisms of GNB3 gene under different genetic models (additive, dominant and recessive models). Results The genotype dis- tribution and allele frequencies of C825T, C1429T and G(-350)A polymorphisms did not differ significantly between hypertensive patients and control subjects, either when the full sample was assessed, or when the sample was stratified by gender. No significant association was observed between C825T, C 1429T and G(-350)A polymorphisms and the risk of essential hypertension in any genetic model. Linkage dis- equilibrium was only detected between C825T and C 1429T polymorphisms. Haplotype analyses observed that none of the three estimated haplotypes significantly increased the risk of hypertension. Conclusions Our study suggested that the GNB3 gene polymorphisms [C825T, C 1429T and G(-350)A] were not significantly associated with essential hypertension in northern Han Chinese population.展开更多
基金supported by the National Natural Science Foundation of China(22278090,21978055)Natural Science Foundation of Guangdong Province,China(2022A1515012088)the Science and Technology Planning Project of Guangdong Province,China(2022A0505030073,2022A0505030013).
文摘Ce-encapsulated Beta zeolite was synthesized by a one-pot hydrothermal method with citric acid complexing Ce in the absence of Na species.Additional citric acid can effectively prevent the deposition of Ce species during the hydrothermal synthesis of zeolites,leading to uniform distribution of Ce cluster in the framework of Beta zeolites.Moreover,the sodium-free synthesis system resulted that the Brønsted acid sites were mainly located on the straight channels and external surface of Beta zeolites,improving the utilization of Brønsted acid sites.In addition,Ce encapsulated Beta zeolites showed enhanced activity and robust stability in the alkylation of benzene with 1-dodecene based on the synergistic effect between Ce species and Brønsted acid sites,which pave the way for its practical application in the production of alkylbenzene.
文摘The conversion of acetone derived from biomass to isobutene has attracted extensive attentions.In comparison with Brønsted acidic catalyst,Lewis acidic catalyst could exhibit a better catalytic performance with a higher isobutene selectivity.However,the catalyst stability remains a key problem for the long-running acetone conversion and the reasons for catalyst deactivation are poorly understood up to now.Herein,the deactivation mechanism of Lewis acidic Y/Beta catalyst during the acetone to isobutene conversion was investigated by various characterization techniques,including acetone-temperature-programmed surface reaction,gas chromatography-mass spectrometry,in situ ultraviolet-visible,and ^(13)C cross polarization magic angle spinning nuclear magnetic resonance spectroscopy.A successive aldol condensation and cyclization were observed as the main side-reactions during the acetone conversion at Lewis acidic Y sites.In comparison with the low reaction temperature,a rapid formation and accumulation of the larger cyclic unsaturated aldehydes/ketones and aromatics could be observed,and which could strongly adsorb on the Lewis acidic sites,and thus cause the catalyst deactivation eventually.After a simple calcination,the coke deposits could be easily removed and the catalytic activity could be well restored.
文摘This study was carried out to assess the prevalence of resistance genes in strains of Escherichia coli and Salmonella spp. isolated from free-range chickens in Ouagadougou, where resistant bacteria can be transmitted to humans via faeces or contaminated meat. A total of 280 strains of Escherichia coli and 129 strains of Salmonella spp. resistant to at least one beta-lactam or carbapenem antibiotic were used in this study. PCR analyses revealed the presence of ESBL (extended spectrum beta lactamase) resistance genes in Escherichia coli isolates, with 3.21% (9/280) possessing the CTX-M (Cefotaximase) gene, 15.35% (43/280) had the SHV (Sulfhydril Variable) gene, and 11.42% (32/280) had carbapenemase resistance genes, more specifically IMP (Imipenemase metallo-beta-lactamase). As regards Salmonella spp. strains, only the presence of the SHV (Sulfhydril Variable) gene was identified in 2.32% (3/129) of isolates belonging to the ESBL family, while 26.35% (34/129) and 13.95% (18/129) of isolates respectively possessed the IMP (Imipenemase metallo-beta-lactamase) and NDM (New Delhi metallo-β-lactamase) genes, both of the carbapenemase type. The significant prevalence of resistance genes in bacterial strains isolated from chickens sold outdoors in Ouagadougou raises major public health concerns, due to the possible transmission of these resistant strains to humans through the consumption of contaminated meat, thus complicating the treatment of bacterial infections.
文摘Drinking good quality water is essential for better health. It is therefore essential to assess the radiological quality of all water consumed in the District of Abidjan in order to prevent related hazards. Thus, the objective of this study was to assess the risk of cancer due to the ingestion of alpha and beta emitting radionuclides in the different types of water consumed in the region. A total of 63 water samples with 43 tap water samples, 5 bottled mineral water and 15 sachet water samples was collected and taken to GAEC laboratory for analysis. The low background Gas-less Automatic Alpha/Beta counting system (Canberra iMatic<sup>TM</sup>) was used to determine alpha and beta activity concentrations. Activity concentrations of both gross alpha and gross beta obtained in water sample were respectively lower than the WHO recommended limits of 0.1 Bq/l and 1 Bq/l. Also, the annual effective dose and total equivalent effective dose found in mineral bottled water samples were higher than in other types of water. The assessment of radiological lifetime risk has shown values of cancer risk due to ingestion alpha and beta emitters lower than recommended limit. These results indicate that there is no health hazard associated to consumption of water in the District of Abidjan.
基金supported by the National Key Basic Research Program of China (973 Program, 2013CB933201)the National Natural Science Foun-dation of China (21577034, 21333003, 91545103)+1 种基金Science and Technology Commission of Shanghai Municipality (16ZR1407900)Fundamental Research Funds for the Central Universities (WJ1514020)~~
文摘Fe doped Beta zeolite with different Fe contents were prepared by ion exchange by changing the volume or the concentration of a Fe salt solution. For a particular mass of Fe salt precursor, the concentration of the metal salt solution during ion exchange influenced the ion exchange capacity of Fe, and resulted in different activities of the Fe-Beta catalyst. Fe-Beta catalysts with the Fe contents of (2.6, 6.3 and 9) wt% were synthesized using different amounts of 0.02 mol/L Fe salt solution. These catalysts were studied by various characterization techniques and their NH3-SCR activities were evaluated. The Fe-Beta catalyst with the Fe content of 6.3 wt% exhibited the highest activity, with a temperature range of 202-616℃ where the NOx conversion was 〉 80%. The Fe content in Beta zeolite did not influence the structure of Beta zeolite and valence state of Fe. Compared with the Fe-Beta catalysts with low Fe content (2.6 wt%), Fe-Beta catalysts with 6.3 wt% Fe content possessed more isolated Fe3. active sites which led to its higher NH3-SCR activity. A high capacity for NH3 and NO adsorption, and a high activity for NO oxidation also contributed to the high NH3-SCR activity of the Fe-Beta catalyst with 6.3 wt%. However, when the Fe content was further increased to 9.0 wt%, the amount of FexOy nanoparticles increased while the amount of isolated Fe3+ active sites was unchanged, which promoted NH3 oxidation and decreased the NH3-SCR activity at high temperature.
基金supported by Strategic Priority Research Program of the Chinese Academy of Sciences(XDA07020300)~~
文摘Zeolite Beta containing ultra-small CoO particles was synthesized from a one-step hydrothermal process. The synthesis route involves the pre-mixture of hydrofluoric acid with tetraethylammo- nium hydroxide (in a molar ratio of 1.3-1.5:1) before the addition of a silicon and cobalt source.Investigations by scanning electron microscopy, X-ray diffraction, UV-Vi s spectroscopy, X-ray pho-toelectron spectroscopy, H 2 -temperature-programmed reduct i on and transmi ssi on el ectron mi -croscopy confirm the presence of ultra-small CoO particles in the zeolite Beta structure. The ul-tra-small CoO particles in zeolite Beta present high stability against both oxidation and reduction atmospheres at high temperatures. The catalytic performance of the CoO-containing zeolite Beta catalysts was compared with other Co-containing zeolites by evaluating ethylbenzene oxidation reactivity. The CoO-containing zeolite Beta exhibits high ethylbenzene conversion and high selectiv-ity to acetophenone and 1-phenylethanol. The high activity of this catalyst system can be attributed to the high dispersion of the ultra-small CoO particles in the Beta structure.
文摘AIM: To investigate the expression of the transforming growth factor beta 1(TGF-beta 1) mRNA in different stages of alcoholic liver disease (ALD) and its clinical value. METHODS: One hundred and seven male alcoholics were grouped by clinical findings into four groups: alcohol abusers without liver impairment (n =22), alcoholic steatosis (n =30); alcoholic hepatitis (n=31); and alcoholic cirrhosis(n=24). Using peripheral blood mononuclear cells (PBMC) as samples the gene expression of TGF-beta 1 was examined quantitatively by reverse transcription polymerase chain reaction (RT-PCR) and dot blot. There are 34 healthy subjects served as control. RESULTS: The expression of TGF-beta 1 from all ALD patients was significantly greater than that in controls (1.320 +/- 1.162 vs 0.808 +/- 0.276, P【0.001). The differences of the expressions were significant between the patients from each groups (alcoholic steatosis, alcoholic hepatitis and alcoholic cirrhosis) and the controls (1.168 +/- 0.852, 1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.808 +/- 0.276, P【0.050). No significant differences of TGF -beta 1 mRNA expression were observed between alcohol abusers without liver impairment and controls. The expressions in patients with alcoholic hepatitis and alcoholic cirrhosis were significantly greater than that in alcohol abusers respectively (1.462 +/- 1.657, 1.329 +/- 0.610 vs 0.841 +/- 0.706, P【0.050). No significant differences of TGF-beta 1 mRNA expression were observed between alcoholic fatty liver men and alcohol abusers. CONCLUSION: TGF-beta 1 expression level can be a risk factor for alcoholic liver disease and might be related to the inflammatory activity and fibrosis of the liver in patients.
基金support of the U.S. National Science Foundation (awards 8206992, 8906869, 9405933, 9909947, 0948585 to S.P. Hubbell)the John D. and Catherine D. McArthur Foundation+1 种基金the Smithsonian Tropical Research Institutesupported by research grant #7738 from the Natural Sciences and Engineering Research Council of Canada (NSERC) to P. Legendre
文摘Background: Ecologists are interested in assessing the spatial and temporal variation in ecological surveys repeated over time. This paper compares the 1985 and 2015 surveys of the Barro Colorado Forest Dynamics plot(BCI), Panama,divided into 1250(20 m × 20 m) quadrats.Methods, spatial analysis: Total beta diversity was measured as the total variance of the Hellinger-transformed community data throughout the BCI plot. Total beta was partitioned into contributions of individual sites(LCBD indices), which were tested for significance and mapped.Results, spatial analysis: LCBD indices indicated the sites with exceptional community composition. In 1985,they were mostly found in the swamp habitat. In the 2015 survey, none of the swamp quadrats had significant LCBDs.What happened to the tree community in the interval?Methods, temporal analysis: The dissimilarity in community composition in each quadrat was measured between time 1(1985) and time 2(2015). Temporal Beta Indices(TBI) were computed from abundance and presence-absence data and tested for significance. TBI indices can be decomposed into B = species(or abundances-per-species) losses and C = species(or abundances-per-species) gains. B-C plots were produced; they display visually the relative importance of the loss and gain components, through time, across the sites.Results, temporal analysis: In BCI, quadrats with significant TBI indices were found in the swamp area, which is shrinking in importance due to changes to the local climate. A published habitat classification divided the BCI forest plot into six habitat zones. Graphs of the B and C components were produced for each habitat group. Group 4(the swamp) was dominated by species(and abundances-per-species) gains whereas the five other habitat groups were dominated by losses, some groups more than others.Conclusions: We identified the species that had changed the most in abundances in the swamp between T1 and T2.This analysis supported the hypothesis that the swamp is drying out and is invaded by species from the surrounding area. Analysis of the B and C components of temporal beta diversity bring us to the heart of the mechanisms of community change through time: losses(B) and gains(C) of species, losses and gains of individuals of various species. TBI analysis is especially interesting in species-rich communities where we cannot examine the changes in every species individually.
基金supported in part by the Japan Society for the Promotion of Science(JSPS)Grant-in-Aid for Scientific Research,No.17K11813(to LX)Tai Shan Industrial Experts Program of China No.TSCY20170233(to FL)。
文摘As an aging-associated degenerative disease,Alzheimer’s disease is characterized by the deposition of amyloid beta(Aβ),oxidative stress,inflammation,dysfunction and loss of cholinergic neurons.Colla Corii Asini(CCA)is a traditional Chinese medicine which has been used for feebleness-related diseases and anti-aging.CCA might delay aging-induced degenerative changes in neurons.In the present study,we evaluated antioxidant activity,cytoprotective effects,and Aβremovability of enzyme-digested Colla Corii Asini(CCAD).Oxygen radical absorbance capacity(ORAC)activity assay showed that,as compared to gelatins from the skin of porcine,bovine and cold water fish,CCA exhibited the highest ORAC activity.The ORAC activity of CCA and CCAD was increased gradually by the length of time in storage.Ultrastructure analysis by scanning electron microscopy showed that among CCA manufactured in 2008,2013,2017 and gelatin from cold water fish skin,CCA manufactured in 2008 presented the smoothest surface structure.We further tested the protective effects of CCAD(manufactured in 2008)and enzyme-digested gelatin from cold water fish skin(FGD)on hydrogen peroxide(H2O2)-induced cell death in nerve growth factor-differentiated neuronal-like PC12 cells.Presto blue assay showed that both FGD and CCAD at 0.5 mg/m L increased cell viability in H2O2-treated neuronal-like PC12 cells.The protection of CCAD was significantly superior to that of FGD.Acetylcholinesterase(Ach E)assay showed that both FGD and CCAD inhibited Ach E activity in nerve growth factor-differentiated neuronal-like PC12 cells to 89.1%and 74.5%of that in non-treated cells,respectively.The data suggest that CCAD might be able to increase the neurotransmitter acetylcholine.Although CCAD inhibited Ach E activity in neuronal-like PC12 cells,CCAD prevented H2O2-induced abnormal deterioration of Ach E.ELISA and neprilysin activity assay results indicated that CCAD reduced amyloid beta accumulation and increased neprilysin activity in Aβ1–42-treated neuronal-like PC12 cells,suggesting that CCAD can enhance Aβclearance.Our results suggest that CCA might be useful for preventing and treating Alzheimer’s disease.
基金This work was supported by Major State Basic Research Development Program of the People's Republic of China (No. 2001CB510305).
文摘Objective To study the relationship between polymorphism of cystathionine beta synthase (CBS) gene and development of congenital heart disease (CHD). Methods One hundred and twenty-seven CHD case-parent triads were recruited from Liaoning Province as patient group, and 129 healthy subjects without family history of birth defect were simultaneously recruited as control group together with their biological parents. For all subjects the polymorphism of CBS gene G919A locus was examined by PCR-ARMS method, Results The frequencies of three genotypes (w/w, w/m, and m/m) in control group were 27.2%, 58,4%, and 14.4%, respectively, with no significant difference in gender. A significant difference in the allele frequency was found between CHD patients and controls, the wild allele frequency was 67,9% in patients and 55.7% in controls CHD parents' genotype distribution was significantly different from that in controls. Further comparison of each type of CHD showed that genotype frequencies in several CHD subtypes were significantly different from those in their corresponding controls. The results of TDT analysis showed that no allele transmission disequilibrium existed in CHD nuclear families. Conclusions CBS gene G919A mutation is associated with the development of CHD, and the mutated allele may decrease the risk of CHD.
基金funded by the National Centre for the Replacement Refinement&Reduction of Animals in Research(NC3R:Grant#NC/L001152/1)the Macular Society,UK,National Eye Research Centrethe Gift of Sight Appeal
文摘e-related macular degeneration (AMD) causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer's-linked amyloid beta (Aβ) group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer's disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for latestage AMD.
基金Supported by National Natural Science Foundation of China,No.81300286 to Liu SZ and No.81471019 to Hu SYFoundation for Outstanding Young Scientist in Shandong Province,No.BS2013YY031 to Liu SZ+1 种基金Science and Technology Development Program of Shandong Province,No.2014GGE27485 to Liu SZSpecialized Research Fund for the Doctoral Program of Higher Education of China,No.20130131120069 to Liu SZ
文摘AIM To investigate factors causing diabetes recurrence after sleeve gastrectomy(SG)and duodenal-jejunal bypass(DJB).METHODS SG and DJB were performed on rats with diabetes induced by high-fat diet(HFD)and streptozotocin(STZ).HFD was used to induce diabetes recurrence at 4 wk postoperatively.Body weight,oral glucose tolerance test,homeostatic model assessment of insulin resistance(HOMA-IR),insulin signaling[IR,insulin receptor substrate(IRS 1,IRS2,phosphatidylinositol3-kinase and AKT in liver and skeletal muscle],oral glucose stimulated insulin secretion,beta-cell morphology(mass,apoptosis and insulin secretion),glucagon-like peptide(GLP)-1,PYY and ghrelin were compared among SG rats with common low-fat diet(SG-LFD),SG with HFD(SG-HFD),DJB rats with LFD(DJB-LFD),DJB with HFD(DJB-HFD)and shamoperation with LFD(Sham)at targeted postoperative times.RESULTS SG and DJB resulted in significant improvement in glucose tolerance,lower HOMA-IR,up-regulated hepatic and muscular insulin signaling,higher levels of oral glucose-stimulated insulin secretion,bigger betacell mass,higher immunofluorescence intensity of insulin,fewer transferase-mediated d UTP-biotin 3’nick end-labeling(TUNEL)-positive beta cells and higher postprandial GLP-1 and PYY levels than in the Sham group.The improvement in glucose tolerance was reversed at 12 wk postoperatively.Compared with the SG-LFD and DJB-LFD groups,the SG-HFD and DJB-HFD groups showed higher HOMA-IR,down-regulated hepatic and muscular insulin signaling,and more TUNEL-positive beta cells.No significant difference was detected between HFD and LFD groups for body weight,glucose-stimulated insulin secretion,betacell mass,immunofluorescence intensity of insulin,and postprandial GLP-1 and PYY levels.Fasting serum ghrelin decreased in SG groups,and there was no difference between HFD-SG and LFD-SG groups.CONCLUSION HFD reverses the improvement in glucose homeostasis after SG and DJB.Diabetes recurrence may correlate with re-impaired insulin sensitivity,but not with alterations of beta-cell function and body weight.
文摘This study aimed to explore the mechanism of a novel mutation (p.Lys38Glu) in apolipoprotein H (APOH) gene causing hereditary beta2-glycoprotein I (β2GPI) deficiency and thrombosis in a proband with thrombophilia. The plasma level of β2GPI was measured by ELISA and Western blotting, and anti-β2GPI antibody by ELISA. Lupus anticoagulant (LA) was assayed using the dilute Russell viper venom time. Deficiency of the major natural anticoagulants including protein C (PC), protein S (PS), antithrombin (AT) and thrombomodulin (TM) was excluded from the proband. A mutation analysis was performed by amplification and sequencing of the APOH gene. Wild type and mutant (c.112A〉G) APOH expression plasmids were constructed and transfected into HEK293T cells. The results showed that the thrornbin generation capacity of the proband was higher than that of the other family members. Missense mutation p.Lys38Glu in APOH gene and LA coexisted in the proband. The mutation led to β2GPI deficiency and thrombosis by impairing the protein production and inhibiting the platelet aggregation. It was concluded that the recurrent thrombosis of the proband is associated with the coexistence ofp.Lys38Glu mutation in APOH gene and LA in plasma.
基金grants of the National High Technology Research and Development Program,grants of the National Eleventh Five-year Plan Program from the Ministry of Science and Technology of China,Beijing Natural Science Foundation
文摘Objective To explore the association between the three polymorphisms [ C825T, C1429T and G(-350)A] of the gene encoding the G protein beta 3 subunit (GNB3) and hypertension by performing a case-control study in the northern Han Chinese population. Methods We recnaited 731 hypertensive patients and 673 control subjects (the calculated power value was 〉 0.8). Genotyping was performed to identify C825T, C1429T and G(-350)A polymorphisms using the TaqMan assay. Comparisons of allelic and genotypic frequencies between cases and controls were made by using the chi-square test. Logistic regression analyses were performed to investigate the relationships between the three polymorphisms of GNB3 gene under different genetic models (additive, dominant and recessive models). Results The genotype dis- tribution and allele frequencies of C825T, C1429T and G(-350)A polymorphisms did not differ significantly between hypertensive patients and control subjects, either when the full sample was assessed, or when the sample was stratified by gender. No significant association was observed between C825T, C 1429T and G(-350)A polymorphisms and the risk of essential hypertension in any genetic model. Linkage dis- equilibrium was only detected between C825T and C 1429T polymorphisms. Haplotype analyses observed that none of the three estimated haplotypes significantly increased the risk of hypertension. Conclusions Our study suggested that the GNB3 gene polymorphisms [C825T, C 1429T and G(-350)A] were not significantly associated with essential hypertension in northern Han Chinese population.