To optimize turn on velocity of the SiC LIMS,we proposed a new structure for the LIMS that incorporates an opti-mized n^(+)layer and a multi-light triggered electrode design for the anode.The chip size is 5.5 mm×...To optimize turn on velocity of the SiC LIMS,we proposed a new structure for the LIMS that incorporates an opti-mized n^(+)layer and a multi-light triggered electrode design for the anode.The chip size is 5.5 mm×5.5 mm in dimension.The experiment results indicate that the saturation laser energy required to trigger the prepared SiC LIMS has been decreased from 1.8 mJ to 40μJ,with the forward blocking voltage of the prepared SiC LIMSs capable of withstanding over 7000 V.The leakage current is about 0.3μA at room temperature,and the output current density achieves 4.25 kA/cm^(2)(with di/dt larger than 20 kA/μs).展开更多
Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we gener...Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we generated a novel mouse model with a conditional C451A mutation in Esr1,which enables selective knockout of the palmitoylation site essential for the membrane localization of ERα(C451A^(f/f)).First,we used Runx2-Cre mice to generate Runx2-C451A^(f/f)mice with conditional inactivation of mERαsignaling in Runx2-expressing osteoblast lineage cells.No significant changes were observed in body weight,weights of estrogen-responsive organs,or serum concentrations of estradiol between female Runx2-C451A^(f/f)and homozygous C451A^(f/f)littermate controls.High-resolution microcomputed tomography analysis showed a consistent decrease in cortical bone mass in the tibia,femur,and vertebra L5 of Runx2-C451A^(f/f)mice and three-point bending analysis of humerus revealed an impaired mechanical bone strength in Runx2-C451A^(f/f)female mice compared to controls.Additionally,primary osteoblast cultures from mice lacking mERαsignaling showed impaired differentiation compared to controls.展开更多
There is currently no effective medical treatment for temporomandibular joint osteoarthritis(TMJ-OA) due to a limited understanding of its pathogenesis. This study was undertaken to investigate the key role of transfo...There is currently no effective medical treatment for temporomandibular joint osteoarthritis(TMJ-OA) due to a limited understanding of its pathogenesis. This study was undertaken to investigate the key role of transforming growth factor-β(TGF-β)signalling in the cartilage and subchondral bone of the TMJ using a temporomandibular joint disorder(TMD) rat model, an ageing mouse model and a Camurati–Engelmann disease(CED) mouse model. In the three animal models, the subchondral bone phenotypes in the mandibular condyles were evaluated by μCT, and changes in TMJ condyles were examined by TRAP staining and immunohistochemical analysis of Osterix and p-Smad2/3. Condyle degradation was confirmed by Safranin O staining, the Mankin and OARSI scoring systems and type X collagen(Col X), p-Smad2/3 a and Osterix immunohistochemical analyses. We found apparent histological phenotypes of TMJ-OA in the TMD, ageing and CED animal models, with abnormal activation of TGF-βsignalling in the condylar cartilage and subchondral bone. Moreover, inhibition of TGF-β receptor I attenuated TMJ-OA progression in the TMD models. Therefore, aberrant activation of TGF-β signalling could be a key player in TMJ-OA development.展开更多
China’s Bei Dou-3 global positioning system has been officially initiated construction with four global networking satel ites to be launched by the end of this year,according to the announcement at the Sixth China An...China’s Bei Dou-3 global positioning system has been officially initiated construction with four global networking satel ites to be launched by the end of this year,according to the announcement at the Sixth China Annual Meeting of Satellite Navigation and Location Services in Shenzhen on September 16 and the First Satellite Application International Exposition held.展开更多
Cas1-and-Cas2-mediated new spacer acquisition is an essential process for bacterial adaptive immunity.The process is critical for the ecology of the oral microflora and oral health.Although molecular mechanisms for sp...Cas1-and-Cas2-mediated new spacer acquisition is an essential process for bacterial adaptive immunity.The process is critical for the ecology of the oral microflora and oral health.Although molecular mechanisms for spacer acquisition are known,it has never been established if this process is associated with the morphological changes of bacteria.In this study,we demonstrated a novel Cas2-induced filamentation phenotype in E.coli that was regulated by co-expression of the Cas1 protein.A 30 amino acid motif at the carboxyl terminus of Cas2 is necessary for this function.By imaging analysis,we provided evidence to argue that Cas-induced filamentation is a step coupled with new spacer acquisition during which filaments are characterised by polyploidy with asymmetric cell division.This work may open new opportunities to investigate the adaptive immune response and microbial balance for oral health.展开更多
OBJECTIVE It′s known that post-retrieval extinction but not extinction alone could erase fear memory. However, whether the coding pattern of original fear engrams is remodeled or inhibited remains largely unclear. He...OBJECTIVE It′s known that post-retrieval extinction but not extinction alone could erase fear memory. However, whether the coding pattern of original fear engrams is remodeled or inhibited remains largely unclear. Here we try to investigate whether the coding pattern of memory engrams is altered during post-retrieval extinction induced memory updating. METHODS To answer the question, by using activity-dependent neuronal-tagging technology, neuronal tracing technique combined with optogenetic manipulation and in vivo calcium imaging, we identified the fear and extinction cells in PrL and BLA and investigated the dynamic encoding of memory engram ensembles in the PrL and BLA during CS versus US initiated memory updating.RESULTS We found increased reactivation of engram cells in the prelimbic cortex and basolateral amygdala during memory updating. Moreover, conditioned stimulus and unconditioned stimulu sinitiated memory updating depend on the engram cells reactivation in the prelimbic cortex or basolateral amygdala respectively. Finally,we found memory updating causes increased overlapping between fear and extinction cells and the original fear engrams encoding was altered during memory updating. CONCLUSION Our data provide the first evidence to show the overlapping ensembles between fear and extinction cells and functional reorganization of original engrams underlying conditioned stimulus and unconditioned stimulus initiated memory updating.展开更多
A novel atmospheric plasma device developed in this paper, which is more effective and convenient to study the plasma-initiated polymerization (PIP) than conventional setup. The structure and mechanism of the device i...A novel atmospheric plasma device developed in this paper, which is more effective and convenient to study the plasma-initiated polymerization (PIP) than conventional setup. The structure and mechanism of the device is introduced. Some plasma-initiated polymerization experiments are carried out on the device, and the conversion of AA (Acrylic acid) and AM (Acryl amide) atmospheric (N2) plasma polymerization are respectively 89% and 94% after 120 h post polymerization, whereby IR spectra of the product (AA, AM). Our PIP result are confirmed.展开更多
Plasma initiated polymerization is a kind of well-known radical polymerization mechanism, but it has the ＇living＇ polymerization feature and produces ultra-high molecular weight polymer. In order to explain such phe...Plasma initiated polymerization is a kind of well-known radical polymerization mechanism, but it has the ＇living＇ polymerization feature and produces ultra-high molecular weight polymer. In order to explain such phenomena, we calculate the basic data of plasma initiated polymerization of methylmethacrylate （MMA） according to the principle of polymer physics and chemistry. It results in that the radical concentration ranges from 10^-12mol/L to 10^-16mol/L corresponding to the radical life in 10^4s to 10^8s, which means the radicals have a long lifetime. Moreover because of the long lifetime radicals it causes a unique feature rather than the common radical polymerization, and also shows no ＂living polymerization＂. It is noticed in experiments that there are two key factors playing important roles. One is the effective radical amount produced during the plasma discharging while the another is the diffusion factor.展开更多
The polymerization of methyl acrylate was sensitive to UV light. Under UV light,the rate of polymerization is 8 times as high as the rate in dark.The overall activation energy was decreased by the UV light (313nm).A t...The polymerization of methyl acrylate was sensitive to UV light. Under UV light,the rate of polymerization is 8 times as high as the rate in dark.The overall activation energy was decreased by the UV light (313nm).A tentative explanation is given and the mechanism is discussed.展开更多
he volatile (VPP) and nonvolatile (NVPP) products of methyl methacrylate(MMA) reaction in plasma chamber were used as initiators of MMA polymeriza-tion. From the structure analyses of the two initiators, the measureme...he volatile (VPP) and nonvolatile (NVPP) products of methyl methacrylate(MMA) reaction in plasma chamber were used as initiators of MMA polymeriza-tion. From the structure analyses of the two initiators, the measurement of poly-merization kinetics, and the determination of the molecular weight of resultantpolymers , we found tliat MMA polymerization initiated by NVPP is a typical radical mechanism of polymerization which undergoes a process of continuous initiationand bifunction termination , while VPP-initiated polymerization suggested a mech-anism of living radical process fpolymerization with instantaneous initiation , chain-transfer to monomer , without termination).展开更多
Task scheduling is a key problem for the distributed computation. This thesis analyzes receiver initiated(RI) task scheduling algorithm, finds its weakness and presents an improved algorithm PRI algorithm. This algo...Task scheduling is a key problem for the distributed computation. This thesis analyzes receiver initiated(RI) task scheduling algorithm, finds its weakness and presents an improved algorithm PRI algorithm. This algorithm schedules the concurrent tasks onto network of workstation dynamically at runtime, and initiates task scheduling by the node of low load. The threshold on each node can be modified according to the system information which is periodically detected. Meanwhile, the detecting period can be adjusted in terms of the change of the system state. The result of the experiments shows that the PRI algorithm is superior to the RI algorithm.展开更多
The homopolymerization of 5-methyl-5-hexen-2,4-dione (methacryloylacetone, MAA), a vinyl monomer having beta-diketone group, was carried out in the presence of benzophenone (BP)/N, N-dimenthyl-4-toluidine (DMT) system...The homopolymerization of 5-methyl-5-hexen-2,4-dione (methacryloylacetone, MAA), a vinyl monomer having beta-diketone group, was carried out in the presence of benzophenone (BP)/N, N-dimenthyl-4-toluidine (DMT) system. Graft polymerization of acrylamide initiated by eerie ion onto the homopolymer film was investigated and the mechanism of the grafting reaction was proposed on the basis of ESR study. The grafted copolymer was characterized by means of grafting percentage, water absorption, XPS spectra and scanning electron photomicrographs.展开更多
The integrity of the published record of scientific research depends not only on the validity of the science but also on honesty in authorship. Editors and readers need to be confident that authors have undertaken the...The integrity of the published record of scientific research depends not only on the validity of the science but also on honesty in authorship. Editors and readers need to be confident that authors have undertaken the work described and have ensured that the manuscript accurately reflects their work, irrespective of whether they took the lead in writing or sought assistance from a medical writer. The scientific record is distorted if the primary purpose of an article is to persuade readers in favor of a special interest, rather than to inform and educate, and this purpose is concealed.展开更多
Since tertiary amines （Cα-H） can be oxidized by peroxides and transition metal cations in high oxidation states into Ca2＋ radicals to initiate vinylic polymerizations of methacrylates, Cu2＋ and 2-（N,N-dimethylam...Since tertiary amines （Cα-H） can be oxidized by peroxides and transition metal cations in high oxidation states into Ca2＋ radicals to initiate vinylic polymerizations of methacrylates, Cu2＋ and 2-（N,N-dimethylamino）ethyl methacrylate （DMAEMA） form a polymerizable redox initiating pair, in which DMAEMA serves as an intrinsically reducing inimer. CuSOa-catalyzed aqueous self-initiated radical polymerizations of DMAEMA were successfully performed at ambient temperature via a continuous Cu2＋-tertiary amine redox initiation based on catalyst regeneration in the presence of O2. The polymerization kinetics was monitored by gas chromatography and the structure of PDMAEMA was characterized by gel- permeation chromatography, nuclear magnetic resonance spectroscopy, laser light scattering and online intrinsic-viscosity analysis. Both the monomer conversion and the molecular weight of PDMAEMA increase with the reaction while the molecular weight distribution maintains rather broad, as the Cu2＋-DMAEMA redox-initiation leads to linear PDMAEMA chains with terminal methacryloxyl moieties, and the Cu2＋-PDMAEMA redox-initiation results in branched chains. The branched topology forms and develops only for the high-MW components of the PDMAEMA. Our results provide a facile strategy to prepare branched polymers from such commercially available intrinsically reducing inimers using a negligible concentration of regenerative air-stable catalysts.展开更多
2016 China(Beijing)Internet Application Innovation Development Forum,the CCPIT Commercial Sub-Council Internet Application Committee Inauguration was held in Beijing on September13,hosted by the CCPIT Sub-Council and ...2016 China(Beijing)Internet Application Innovation Development Forum,the CCPIT Commercial Sub-Council Internet Application Committee Inauguration was held in Beijing on September13,hosted by the CCPIT Sub-Council and EventBank.As a trade promotion agency within the trade promotion system focusing on trade and investment promotion in the commercial and service sector。展开更多
The polymerization of acrylamide and acrylonitrile using ceric ion as initiator can be promoted greatly by the tartaric acid. The kinetics of acrylamide polymerization initiated by ceric ion/tartaric acid has been stu...The polymerization of acrylamide and acrylonitrile using ceric ion as initiator can be promoted greatly by the tartaric acid. The kinetics of acrylamide polymerization initiated by ceric ion/tartaric acid has been studied. The presence of the species of tartaric acid in Polyacrylonitrile produced by using ceric ion/tartaric acid as niitiator has been confirmed by FT-IR analysis.展开更多
<strong>Introduction:</strong> Viral hepatitis is a major public health challenge that requires an urgent response. Reducing mortality requires major scale-up in prevention, testing and treatment access;co...<strong>Introduction:</strong> Viral hepatitis is a major public health challenge that requires an urgent response. Reducing mortality requires major scale-up in prevention, testing and treatment access;coverage in HBV vaccination, testing and treatment is low and must accelerate massively to achieve the 2030 targets. Less than 1% of HBV-infected individuals are diagnosed in Sub-Sahara Africa, despite the availability of rapid tests with good diagnostic accuracy. <strong>Materials and Methods:</strong> This was retrospective cross sectional study conducted in Federal Teaching Hospital Gombe, in North East Nigeria. All children and adults who presented to the out-patient departments, and those that were admitted irrespective of their HIV and or Hepatitis C virus status and had Hepatitis B and/or Hepatitis B envelope antigen test were conducted between 2000 to 2015. All children and adults were tested using the Hospital standard for Hepatitis B surface antigen test strip. <strong>Results:</strong> Between 2000 and 2014, 739,456 children and adults were admitted and reviewed in the outpatient units of the Federal Teaching Hospital Gombe;there were 685,552 adults and 53,904 children. Children constituted 7.3% (53,904/739,456) of admissions and outpatient consultations. 2.8% (210/7570), 3.3% (773/23,783), 3.6% (1145/32,142), 5.2% (1694/33,043), 3.3% (986/29,216), 1.9% (661/3321), 0.1% (53/41,626), 0.2% (113/46,634), 2.6% (1418/54,423), 5.4% (3717/69,696), 3.7% (2332/62,086), 3.5% (3241/90,623), 3.2% (2881/89,398), 3.8% (2428/62,687), 2.8% (1835/63,208) of children and adults were tested for HBsAg in 2000, 2001, 20002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 and 2014 respectively. 23,487 children and adults were tested for HBsAg with a cumulative testing rate of 3%. Overall 4465/23,487 children and adults were seropositive for HBsAg giving a cumulative prevalence of 19%. <strong>Conclusion:</strong> HBV screening in our health facility is very low. Massive scale up in awareness and HBV vaccination are required. Provider initiated testing and counseling for HBV in health facilities needs support for implementation in Health Facilities in Sub Saharan Africa.展开更多
perfluoroalkyl iodides reacted with alkenes in acetonitrile solu- tion containing catalytic amount of organophosphine under mild condition to give the corresponding adducts in moderate to good yields.Reaction was show...perfluoroalkyl iodides reacted with alkenes in acetonitrile solu- tion containing catalytic amount of organophosphine under mild condition to give the corresponding adducts in moderate to good yields.Reaction was shown to involve a free radical mechanism.展开更多
基金supported by Rector’s fund of China Academy of Engineering Physics(Grant No.YZJJZQ2022002)the National Natural Science Foundation of China(Grant No.61504127).
文摘To optimize turn on velocity of the SiC LIMS,we proposed a new structure for the LIMS that incorporates an opti-mized n^(+)layer and a multi-light triggered electrode design for the anode.The chip size is 5.5 mm×5.5 mm in dimension.The experiment results indicate that the saturation laser energy required to trigger the prepared SiC LIMS has been decreased from 1.8 mJ to 40μJ,with the forward blocking voltage of the prepared SiC LIMSs capable of withstanding over 7000 V.The leakage current is about 0.3μA at room temperature,and the output current density achieves 4.25 kA/cm^(2)(with di/dt larger than 20 kA/μs).
基金supported by the Swedish Research Council(2017-01286,2020-01840)the Swedish state under the agreement between the Swedish government and the county councils(ALF-agreement)(ALFGBG721581)+2 种基金the Gustaf V 80-years fund(FAI-2018-0466)the IngaBritt and Arne Lundberg Foundation(LU2017-0076)the Novo Nordisk Foundation(26844).
文摘Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we generated a novel mouse model with a conditional C451A mutation in Esr1,which enables selective knockout of the palmitoylation site essential for the membrane localization of ERα(C451A^(f/f)).First,we used Runx2-Cre mice to generate Runx2-C451A^(f/f)mice with conditional inactivation of mERαsignaling in Runx2-expressing osteoblast lineage cells.No significant changes were observed in body weight,weights of estrogen-responsive organs,or serum concentrations of estradiol between female Runx2-C451A^(f/f)and homozygous C451A^(f/f)littermate controls.High-resolution microcomputed tomography analysis showed a consistent decrease in cortical bone mass in the tibia,femur,and vertebra L5 of Runx2-C451A^(f/f)mice and three-point bending analysis of humerus revealed an impaired mechanical bone strength in Runx2-C451A^(f/f)female mice compared to controls.Additionally,primary osteoblast cultures from mice lacking mERαsignaling showed impaired differentiation compared to controls.
基金supported by 2016JQ0054 and NSFC grants 81470711 to L.Z.National Key Research and Development Program of China 2016YFC1102700 to X.Z.
文摘There is currently no effective medical treatment for temporomandibular joint osteoarthritis(TMJ-OA) due to a limited understanding of its pathogenesis. This study was undertaken to investigate the key role of transforming growth factor-β(TGF-β)signalling in the cartilage and subchondral bone of the TMJ using a temporomandibular joint disorder(TMD) rat model, an ageing mouse model and a Camurati–Engelmann disease(CED) mouse model. In the three animal models, the subchondral bone phenotypes in the mandibular condyles were evaluated by μCT, and changes in TMJ condyles were examined by TRAP staining and immunohistochemical analysis of Osterix and p-Smad2/3. Condyle degradation was confirmed by Safranin O staining, the Mankin and OARSI scoring systems and type X collagen(Col X), p-Smad2/3 a and Osterix immunohistochemical analyses. We found apparent histological phenotypes of TMJ-OA in the TMD, ageing and CED animal models, with abnormal activation of TGF-βsignalling in the condylar cartilage and subchondral bone. Moreover, inhibition of TGF-β receptor I attenuated TMJ-OA progression in the TMD models. Therefore, aberrant activation of TGF-β signalling could be a key player in TMJ-OA development.
文摘China’s Bei Dou-3 global positioning system has been officially initiated construction with four global networking satel ites to be launched by the end of this year,according to the announcement at the Sixth China Annual Meeting of Satellite Navigation and Location Services in Shenzhen on September 16 and the First Satellite Application International Exposition held.
基金supported by the National Science and Technology Major Project(2014ZX09101046-004)the National Natural Foundation of China(31600644)
文摘Cas1-and-Cas2-mediated new spacer acquisition is an essential process for bacterial adaptive immunity.The process is critical for the ecology of the oral microflora and oral health.Although molecular mechanisms for spacer acquisition are known,it has never been established if this process is associated with the morphological changes of bacteria.In this study,we demonstrated a novel Cas2-induced filamentation phenotype in E.coli that was regulated by co-expression of the Cas1 protein.A 30 amino acid motif at the carboxyl terminus of Cas2 is necessary for this function.By imaging analysis,we provided evidence to argue that Cas-induced filamentation is a step coupled with new spacer acquisition during which filaments are characterised by polyploidy with asymmetric cell division.This work may open new opportunities to investigate the adaptive immune response and microbial balance for oral health.
文摘OBJECTIVE It′s known that post-retrieval extinction but not extinction alone could erase fear memory. However, whether the coding pattern of original fear engrams is remodeled or inhibited remains largely unclear. Here we try to investigate whether the coding pattern of memory engrams is altered during post-retrieval extinction induced memory updating. METHODS To answer the question, by using activity-dependent neuronal-tagging technology, neuronal tracing technique combined with optogenetic manipulation and in vivo calcium imaging, we identified the fear and extinction cells in PrL and BLA and investigated the dynamic encoding of memory engram ensembles in the PrL and BLA during CS versus US initiated memory updating.RESULTS We found increased reactivation of engram cells in the prelimbic cortex and basolateral amygdala during memory updating. Moreover, conditioned stimulus and unconditioned stimulu sinitiated memory updating depend on the engram cells reactivation in the prelimbic cortex or basolateral amygdala respectively. Finally,we found memory updating causes increased overlapping between fear and extinction cells and the original fear engrams encoding was altered during memory updating. CONCLUSION Our data provide the first evidence to show the overlapping ensembles between fear and extinction cells and functional reorganization of original engrams underlying conditioned stimulus and unconditioned stimulus initiated memory updating.
文摘A novel atmospheric plasma device developed in this paper, which is more effective and convenient to study the plasma-initiated polymerization (PIP) than conventional setup. The structure and mechanism of the device is introduced. Some plasma-initiated polymerization experiments are carried out on the device, and the conversion of AA (Acrylic acid) and AM (Acryl amide) atmospheric (N2) plasma polymerization are respectively 89% and 94% after 120 h post polymerization, whereby IR spectra of the product (AA, AM). Our PIP result are confirmed.
文摘Plasma initiated polymerization is a kind of well-known radical polymerization mechanism, but it has the ＇living＇ polymerization feature and produces ultra-high molecular weight polymer. In order to explain such phenomena, we calculate the basic data of plasma initiated polymerization of methylmethacrylate （MMA） according to the principle of polymer physics and chemistry. It results in that the radical concentration ranges from 10^-12mol/L to 10^-16mol/L corresponding to the radical life in 10^4s to 10^8s, which means the radicals have a long lifetime. Moreover because of the long lifetime radicals it causes a unique feature rather than the common radical polymerization, and also shows no ＂living polymerization＂. It is noticed in experiments that there are two key factors playing important roles. One is the effective radical amount produced during the plasma discharging while the another is the diffusion factor.
文摘The polymerization of methyl acrylate was sensitive to UV light. Under UV light,the rate of polymerization is 8 times as high as the rate in dark.The overall activation energy was decreased by the UV light (313nm).A tentative explanation is given and the mechanism is discussed.
文摘he volatile (VPP) and nonvolatile (NVPP) products of methyl methacrylate(MMA) reaction in plasma chamber were used as initiators of MMA polymeriza-tion. From the structure analyses of the two initiators, the measurement of poly-merization kinetics, and the determination of the molecular weight of resultantpolymers , we found tliat MMA polymerization initiated by NVPP is a typical radical mechanism of polymerization which undergoes a process of continuous initiationand bifunction termination , while VPP-initiated polymerization suggested a mech-anism of living radical process fpolymerization with instantaneous initiation , chain-transfer to monomer , without termination).
文摘Task scheduling is a key problem for the distributed computation. This thesis analyzes receiver initiated(RI) task scheduling algorithm, finds its weakness and presents an improved algorithm PRI algorithm. This algorithm schedules the concurrent tasks onto network of workstation dynamically at runtime, and initiates task scheduling by the node of low load. The threshold on each node can be modified according to the system information which is periodically detected. Meanwhile, the detecting period can be adjusted in terms of the change of the system state. The result of the experiments shows that the PRI algorithm is superior to the RI algorithm.
基金The project was supported by the National Natural Science Foundation of Chna.
文摘The homopolymerization of 5-methyl-5-hexen-2,4-dione (methacryloylacetone, MAA), a vinyl monomer having beta-diketone group, was carried out in the presence of benzophenone (BP)/N, N-dimenthyl-4-toluidine (DMT) system. Graft polymerization of acrylamide initiated by eerie ion onto the homopolymer film was investigated and the mechanism of the grafting reaction was proposed on the basis of ESR study. The grafted copolymer was characterized by means of grafting percentage, water absorption, XPS spectra and scanning electron photomicrographs.
文摘The integrity of the published record of scientific research depends not only on the validity of the science but also on honesty in authorship. Editors and readers need to be confident that authors have undertaken the work described and have ensured that the manuscript accurately reflects their work, irrespective of whether they took the lead in writing or sought assistance from a medical writer. The scientific record is distorted if the primary purpose of an article is to persuade readers in favor of a special interest, rather than to inform and educate, and this purpose is concealed.
基金financially supported by the National Natural Science Foundation of China(No.20674033)Natural Science Foundation of Jiangsu Province(No.BK2008142)Scientific Research Foundation for the Returned Overseas Chinese Scholars(State Education Ministry)
文摘Since tertiary amines （Cα-H） can be oxidized by peroxides and transition metal cations in high oxidation states into Ca2＋ radicals to initiate vinylic polymerizations of methacrylates, Cu2＋ and 2-（N,N-dimethylamino）ethyl methacrylate （DMAEMA） form a polymerizable redox initiating pair, in which DMAEMA serves as an intrinsically reducing inimer. CuSOa-catalyzed aqueous self-initiated radical polymerizations of DMAEMA were successfully performed at ambient temperature via a continuous Cu2＋-tertiary amine redox initiation based on catalyst regeneration in the presence of O2. The polymerization kinetics was monitored by gas chromatography and the structure of PDMAEMA was characterized by gel- permeation chromatography, nuclear magnetic resonance spectroscopy, laser light scattering and online intrinsic-viscosity analysis. Both the monomer conversion and the molecular weight of PDMAEMA increase with the reaction while the molecular weight distribution maintains rather broad, as the Cu2＋-DMAEMA redox-initiation leads to linear PDMAEMA chains with terminal methacryloxyl moieties, and the Cu2＋-PDMAEMA redox-initiation results in branched chains. The branched topology forms and develops only for the high-MW components of the PDMAEMA. Our results provide a facile strategy to prepare branched polymers from such commercially available intrinsically reducing inimers using a negligible concentration of regenerative air-stable catalysts.
文摘2016 China(Beijing)Internet Application Innovation Development Forum,the CCPIT Commercial Sub-Council Internet Application Committee Inauguration was held in Beijing on September13,hosted by the CCPIT Sub-Council and EventBank.As a trade promotion agency within the trade promotion system focusing on trade and investment promotion in the commercial and service sector。
文摘The polymerization of acrylamide and acrylonitrile using ceric ion as initiator can be promoted greatly by the tartaric acid. The kinetics of acrylamide polymerization initiated by ceric ion/tartaric acid has been studied. The presence of the species of tartaric acid in Polyacrylonitrile produced by using ceric ion/tartaric acid as niitiator has been confirmed by FT-IR analysis.
文摘<strong>Introduction:</strong> Viral hepatitis is a major public health challenge that requires an urgent response. Reducing mortality requires major scale-up in prevention, testing and treatment access;coverage in HBV vaccination, testing and treatment is low and must accelerate massively to achieve the 2030 targets. Less than 1% of HBV-infected individuals are diagnosed in Sub-Sahara Africa, despite the availability of rapid tests with good diagnostic accuracy. <strong>Materials and Methods:</strong> This was retrospective cross sectional study conducted in Federal Teaching Hospital Gombe, in North East Nigeria. All children and adults who presented to the out-patient departments, and those that were admitted irrespective of their HIV and or Hepatitis C virus status and had Hepatitis B and/or Hepatitis B envelope antigen test were conducted between 2000 to 2015. All children and adults were tested using the Hospital standard for Hepatitis B surface antigen test strip. <strong>Results:</strong> Between 2000 and 2014, 739,456 children and adults were admitted and reviewed in the outpatient units of the Federal Teaching Hospital Gombe;there were 685,552 adults and 53,904 children. Children constituted 7.3% (53,904/739,456) of admissions and outpatient consultations. 2.8% (210/7570), 3.3% (773/23,783), 3.6% (1145/32,142), 5.2% (1694/33,043), 3.3% (986/29,216), 1.9% (661/3321), 0.1% (53/41,626), 0.2% (113/46,634), 2.6% (1418/54,423), 5.4% (3717/69,696), 3.7% (2332/62,086), 3.5% (3241/90,623), 3.2% (2881/89,398), 3.8% (2428/62,687), 2.8% (1835/63,208) of children and adults were tested for HBsAg in 2000, 2001, 20002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 and 2014 respectively. 23,487 children and adults were tested for HBsAg with a cumulative testing rate of 3%. Overall 4465/23,487 children and adults were seropositive for HBsAg giving a cumulative prevalence of 19%. <strong>Conclusion:</strong> HBV screening in our health facility is very low. Massive scale up in awareness and HBV vaccination are required. Provider initiated testing and counseling for HBV in health facilities needs support for implementation in Health Facilities in Sub Saharan Africa.
文摘perfluoroalkyl iodides reacted with alkenes in acetonitrile solu- tion containing catalytic amount of organophosphine under mild condition to give the corresponding adducts in moderate to good yields.Reaction was shown to involve a free radical mechanism.
