In this paper,a novel pyrogenic pulser was designed both analytically and numerically and was evaluated with empirical tests.The motivation of this study was the need for active control of the aero acoustic pressure o...In this paper,a novel pyrogenic pulser was designed both analytically and numerically and was evaluated with empirical tests.The motivation of this study was the need for active control of the aero acoustic pressure oscillations by injecting the secondary flow into the solid rocket motor.First,in brief,pyrotechnic and pyrogenic pulsers were introduced,and then analytical governing equations were presented in three transient,sinusoidal and Hercules methods.In order to understand the internal pressure of the pulsar and its plume length,the injection flow field was evaluated using the ANSYS-Fluent software with both k-ωSST and k-εRealizable models both at ambient and motor pressure.After that,the design and manufacturing of the pulser hardware and the test process were described.Finally,analytical,numerical and experimental results were discussed.The results show that there is a good correlation between the transient analysis in theory and the numerical solution by the k-ωSST model and the empirical test data.In addition,pyrogenic pulsers design depends on various parameters of motor and pulser charge performance prediction.The quality of pulser charge bonding to its insulator and erosion of its throat path due to injection have an important role to obtain a desirable pulser mass flow rate and plume length.展开更多
Background: Streptococcus pyogenes (group A streptococcus, GAS) is an important human bacterial pathogen. This organism possesses many virulence factors, Streptococcal pyrogenic exotoxinone of these. Aim: Detection of...Background: Streptococcus pyogenes (group A streptococcus, GAS) is an important human bacterial pathogen. This organism possesses many virulence factors, Streptococcal pyrogenic exotoxinone of these. Aim: Detection of Streptococcal pyrogenic exotoxin SpeA and SpeB in isolated Streptococcus pyogenes. Methods: Tow hundred throat swab samples were collected from children with pharyngitis referred to Pediatric Teaching hospital and ENT hospital Wad medani, Sudan, from January to November 2021. The questionnaire was filled out to collect clinical and demographic data. Throat swabs were collected and processed with the standard microbiological procedure to isolate Streptococcus pyogenes. Antimicrobial susceptibility testing was done on all GAS isolates using the Kirby Bauer disk diffusion method according to clinical laboratory standard institute (CLSI) guidelines. Detection of Spy 1258 gene and Streptococcal pyrogenic exotoxins SpeA and SpeB were done by using Multiplex PCR. Results: Amongst the Tow hundred collected samples fifty-one isolates (25.5%) were identified as S. pyogenes. Antibiotic susceptibility testing showed that all the GAS isolates were sensitive to Azithromycin and Penicillin. Sensitivity to Erythromycin, Gentamicin, Clarithromycin, Amoxicillin and Cephalexin were 88.2%, 86.3%, 45.1%, 41.2%, 13.7%, respectively. SpeA was detected in 17 (33.3%) and SpeB in 48 (94.1%). Conclusion: Streptococcal pyrogenic exotoxin genes SpeA and SpeB were detected in 17 (33.3%) and 48 (94.1%) respectively of Streptococcus pyogenes isolates.展开更多
World increasing population and use of energy for transportation and electricity are demanding more extensive and more efficient use of land for agriculture;aiming to both food and biofuel supplies. This communication...World increasing population and use of energy for transportation and electricity are demanding more extensive and more efficient use of land for agriculture;aiming to both food and biofuel supplies. This communication assesses the possible improvements in soil fertility, capture of greenhouse gas, and rainfall, as a result of the large scale terrestrial application of pyrogenic carbon aiming for desert greening. Fossil hydrocarbon coke is taken into account for this proposal because of the exhaustion of light petroleum proven reserves that is leading to a scenario of abundant coke production from the processing of non-conventional reserves.展开更多
Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contribu...Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contributors to staphylococcal food poisoning(SFP),causing vomiting,diarrhea,abdominal pain,headache,muscle cramps,and other acute gastroenteritis symptoms.More than 25 SEs and staphylococcal enterotoxin-like toxins(SE/s)have been described and which together comprise a superfamily of pyrogenic toxin superantigens(SAgs)[2].展开更多
Pyrogen,often as a contaminant,is a key indicator affecting the safety of almost all parenteral drugs(including biologicals,chemicals,traditional Chinese medicines and medical devices).It has become a goal to complete...Pyrogen,often as a contaminant,is a key indicator affecting the safety of almost all parenteral drugs(including biologicals,chemicals,traditional Chinese medicines and medical devices).It has become a goal to completely replace the in vivo rabbit pyrogen test by using the in vitro pyrogen test based on the promoted‘reduction,replacement and refinement’principle,which has been highly considered by regulatory agencies from different countries.We used NF-κB,a central signalling molecule mediating inflammatory responses,as a pyrogenic marker and the monocyte line THP-1 transfected with a luciferase reporter gene regulated by NF-κB as an in vitro model to detect pyrogens by measuring the intensity of a fluorescence signal.Here,we show that this test can quantitatively and sensitively detect endotoxin(lipopolysaccharide from different strains)and nonendotoxin(lipoteichoic acid,zymosan,peptidoglycan,lectin and glucan),has good stability in terms of NF-κB activity and cell phenotypes at 39 cell passages and can be applied to detect pyrogens in biologicals(group A&C meningococcal polysaccharide vaccine;basiliximab;rabies vaccine(Vero cells)for human use,freeze-dried;Japanese encephalitis vaccine(Vero cells),inactivated;insulin aspart injection;human albumin;recombinant human erythropoietin injection(CHO Cell)).The within-laboratory reproducibility of the test in three independent laboratories was 85%,80%and 80%and the interlaboratory reproducibility among laboratories was 83.3%,95.6%and 86.7%.The sensitivity(true positive rate)and specificity(true negative rate)of the test were 89.9%and 90.9%,respectively.In summary,the test provides a novel alternative for pyrogen detection.展开更多
Carbon materials(e.g.,pyrogenic carbon(PyC))are widely used in agricultural soils and can participate in various biogeochemical processes,including iron(Fe)cycling.In soils,Fe (Ⅱ)species have been proposed as the mai...Carbon materials(e.g.,pyrogenic carbon(PyC))are widely used in agricultural soils and can participate in various biogeochemical processes,including iron(Fe)cycling.In soils,Fe (Ⅱ)species have been proposed as the main active contributor to produce reactive oxygen species(ROS),which are involved in various biogeochemical processes.However,the effects of PyC on the transformation of different Fe species in soils and the associated production of ROS are rarely investigated.This study examined the influence of PyC(pyrolyzed at 300-700℃)on Fe (Ⅱ)/Fe(Ⅲ)cycling and hydroxyl radical(·OH)production during redox fluctuations of paddy soils.Results showed that the reduction of Fe(Ⅲ)in soils was facilitated by PyC during anoxic incubation,which was ascribed to the increased abundance of dissimilatory Fe(Ⅲ)-reducing microorganisms(biotic reduction)and the electron exchange capacity of PyC(abiotic reduction).During oxygenation,PyC and higher soil pH promoted the oxidation of active Fe (Ⅱ)species(e.g.,exchangeable and low-crystalline Fe (Ⅱ)),which consequently induced higher yield of·OH and further led to degradation of imidacloprid and inactivation of soil microorganisms.Our results demonstrated that PyC accelerated Fe (Ⅱ)/Fe(Ⅲ)cycling and·OH production during redox fluctuations of paddy soils(especially those with low content of soil organic carbon),providing a new insight for remediation strategies in agricultural fields contaminated with organic pollutants.展开更多
Polycyclic aromatic hydrocarbons(PAHs)are large class of hydrophobic,semi-volatile organic contaminants that may enter the environment from both natural sources and anthropogenic activities.Pyrogenic PAHs arise from t...Polycyclic aromatic hydrocarbons(PAHs)are large class of hydrophobic,semi-volatile organic contaminants that may enter the environment from both natural sources and anthropogenic activities.Pyrogenic PAHs arise from the incomplete combustion of fossil fuels and organic matter and following dispersal via long-range transport and may subsequently deposit in surface waters,soils and sediments of remote regions,including the Arctic.The current review summarizes and discusses Arctic data that is available for combustion-derived PAHs between 2004 and early 2018,focusing largely on data collected from remote,unexploited Arctic regions and from studies that provide some evidence of a pyrogenic origin.The increasing use of attribution ratios,which aid in discriminating PAHs from petrogenic or pyrogenic sources,suggest PAHs found in Arctic marine waters and sediment predominantly originate from natural underwater seeps,while those measured in air,freshwater,and terrestrial environments are likely to have originated from atmospheric and combustion-derived sources.Modeling efforts indicate that atmospheric PAHs in the Canadian and Norwegian Arctic are likely to have originated in the northern hemisphere e predominantly from Western Russia,northern Europe,and North America.East Asia appears to be a minor source of PAHs to the Arctic,despite contributing more than 50%of global PAH emissions.In comparison to the growing data for atmospheric PAHs,environmental data for these compounds in terrestrial and freshwater environments remain scarce.PAHs have been detected in Arctic biota from terrestrial,freshwater and marine environments,indicating exposure,however,levels are generally low,as most organisms efficiently metabolize parent PAHs.Globally,PAH emissions are expected to decline in the future,however models suggest the Arctic may not experience the same magnitude of decline projected for other world regions.Furthermore,future changes in climate may contribute to a re-volatilization of environmental PAHs,providing a source of secondary emissions to the Arctic atmosphere,emphasizing the importance of future monitoring for understanding the sources,fate and impacts of PAHs in the Arctic.展开更多
To further evaluate the causality between endogenous pyrogen (EP)-induced fever andcyclic adenosine- 3’, 5’- monophosphate (cyclic AMP) level. the effects of sodium salicylate(SS) on the febrile response and increas...To further evaluate the causality between endogenous pyrogen (EP)-induced fever andcyclic adenosine- 3’, 5’- monophosphate (cyclic AMP) level. the effects of sodium salicylate(SS) on the febrile response and increased levels of cyclic AMP in both cerebrospinal fluid(c.s.f.) and plasma during EP- induced fever in rabbits were observed. The results suggestthat cyclic AMP is probably involved in the central mediation of EP-induced fever and thatincreased concentration of cyclic AMP in c.s.f. associated with EP- induced fever is not theresult of temperature elevation but appears to be caused by the increased synthesis in the cen-tral nervous system. In addition it is confirmed that blood is impossibly a contributorysource of increased cyclic AMP in c.s.f. during EP fever, and that SS may act subsequentto the increase in cyclic AMP.展开更多
Pyrogenic Carbonaceous Matter(PCM;e.g.,black carbon,biochar,and activated carbon)are solid residues from incomplete combustion of fussil fuel or biomass.They are traditionally viewed as inert adsorbents for sequesteri...Pyrogenic Carbonaceous Matter(PCM;e.g.,black carbon,biochar,and activated carbon)are solid residues from incomplete combustion of fussil fuel or biomass.They are traditionally viewed as inert adsorbents for sequestering contaminants from the aqueous phase or providing surfaces for microbes to grow.In this account,we reviewed the recently discovered reactivity of PCM in promoting both chemical and microbial synergies that are important in pollutant transformation,biogeochemical processes of redox-active elements,and climate change mitigation with respect to the interaction between biochar and nitrous oxide(N2O).Moreover,we focused on our group's work in the PCM-enhanced abiotic transformation of nitrogenous and halogenated pollutants and conducted in-depth analysis of the reaction pathways.To understand what properties of PCM confer its reactivity,our group pioneered the use of PCM-like polymers,namely conjugated microporous polymers(CMPs),to mimic the performance of PCM.This approach allows for the controlled incorporation of specific surface properties(e.g.,quinones)into the polymer network during the polymer synthesis.As a result,the relationship between specific characteristics of PCM and its reactivity in facilitating the decay of a model pollutant was systematically studied in our group's work.The findings summarized in this account help us to better understand an overlooked environmental process where PCM synergistically interacts with various environmental reagents such as hydrogen sulfide and water.Moreover,the knowledge gained in these studies could inform the design of a new generation of reactive carbonaceous materials with tailored properties that are highly efficient in contaminant removal.展开更多
文摘In this paper,a novel pyrogenic pulser was designed both analytically and numerically and was evaluated with empirical tests.The motivation of this study was the need for active control of the aero acoustic pressure oscillations by injecting the secondary flow into the solid rocket motor.First,in brief,pyrotechnic and pyrogenic pulsers were introduced,and then analytical governing equations were presented in three transient,sinusoidal and Hercules methods.In order to understand the internal pressure of the pulsar and its plume length,the injection flow field was evaluated using the ANSYS-Fluent software with both k-ωSST and k-εRealizable models both at ambient and motor pressure.After that,the design and manufacturing of the pulser hardware and the test process were described.Finally,analytical,numerical and experimental results were discussed.The results show that there is a good correlation between the transient analysis in theory and the numerical solution by the k-ωSST model and the empirical test data.In addition,pyrogenic pulsers design depends on various parameters of motor and pulser charge performance prediction.The quality of pulser charge bonding to its insulator and erosion of its throat path due to injection have an important role to obtain a desirable pulser mass flow rate and plume length.
文摘Background: Streptococcus pyogenes (group A streptococcus, GAS) is an important human bacterial pathogen. This organism possesses many virulence factors, Streptococcal pyrogenic exotoxinone of these. Aim: Detection of Streptococcal pyrogenic exotoxin SpeA and SpeB in isolated Streptococcus pyogenes. Methods: Tow hundred throat swab samples were collected from children with pharyngitis referred to Pediatric Teaching hospital and ENT hospital Wad medani, Sudan, from January to November 2021. The questionnaire was filled out to collect clinical and demographic data. Throat swabs were collected and processed with the standard microbiological procedure to isolate Streptococcus pyogenes. Antimicrobial susceptibility testing was done on all GAS isolates using the Kirby Bauer disk diffusion method according to clinical laboratory standard institute (CLSI) guidelines. Detection of Spy 1258 gene and Streptococcal pyrogenic exotoxins SpeA and SpeB were done by using Multiplex PCR. Results: Amongst the Tow hundred collected samples fifty-one isolates (25.5%) were identified as S. pyogenes. Antibiotic susceptibility testing showed that all the GAS isolates were sensitive to Azithromycin and Penicillin. Sensitivity to Erythromycin, Gentamicin, Clarithromycin, Amoxicillin and Cephalexin were 88.2%, 86.3%, 45.1%, 41.2%, 13.7%, respectively. SpeA was detected in 17 (33.3%) and SpeB in 48 (94.1%). Conclusion: Streptococcal pyrogenic exotoxin genes SpeA and SpeB were detected in 17 (33.3%) and 48 (94.1%) respectively of Streptococcus pyogenes isolates.
文摘World increasing population and use of energy for transportation and electricity are demanding more extensive and more efficient use of land for agriculture;aiming to both food and biofuel supplies. This communication assesses the possible improvements in soil fertility, capture of greenhouse gas, and rainfall, as a result of the large scale terrestrial application of pyrogenic carbon aiming for desert greening. Fossil hydrocarbon coke is taken into account for this proposal because of the exhaustion of light petroleum proven reserves that is leading to a scenario of abundant coke production from the processing of non-conventional reserves.
基金supported by the Ministry of Science and Technology of the People’s Republic of China(2022YFD1800400).
文摘Staphylococcus aureus(S.aureus)is the third most common pathogen causing 10.6%of bacterial foodborne illnesses in China in 2021[1].Heat-stable Staphylococcal Enterotoxins(SEs)produced by S.aureus are the main contributors to staphylococcal food poisoning(SFP),causing vomiting,diarrhea,abdominal pain,headache,muscle cramps,and other acute gastroenteritis symptoms.More than 25 SEs and staphylococcal enterotoxin-like toxins(SE/s)have been described and which together comprise a superfamily of pyrogenic toxin superantigens(SAgs)[2].
基金supported by the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(research on quality evaluation and standardisation of innovative vaccines,2021-I2M-5-005)the National Key Laboratory of Drug Regulatory Sciences Fund(research on the alternative test for pyrogen detection based on transgenic cells,2023-NIFDC-28).
文摘Pyrogen,often as a contaminant,is a key indicator affecting the safety of almost all parenteral drugs(including biologicals,chemicals,traditional Chinese medicines and medical devices).It has become a goal to completely replace the in vivo rabbit pyrogen test by using the in vitro pyrogen test based on the promoted‘reduction,replacement and refinement’principle,which has been highly considered by regulatory agencies from different countries.We used NF-κB,a central signalling molecule mediating inflammatory responses,as a pyrogenic marker and the monocyte line THP-1 transfected with a luciferase reporter gene regulated by NF-κB as an in vitro model to detect pyrogens by measuring the intensity of a fluorescence signal.Here,we show that this test can quantitatively and sensitively detect endotoxin(lipopolysaccharide from different strains)and nonendotoxin(lipoteichoic acid,zymosan,peptidoglycan,lectin and glucan),has good stability in terms of NF-κB activity and cell phenotypes at 39 cell passages and can be applied to detect pyrogens in biologicals(group A&C meningococcal polysaccharide vaccine;basiliximab;rabies vaccine(Vero cells)for human use,freeze-dried;Japanese encephalitis vaccine(Vero cells),inactivated;insulin aspart injection;human albumin;recombinant human erythropoietin injection(CHO Cell)).The within-laboratory reproducibility of the test in three independent laboratories was 85%,80%and 80%and the interlaboratory reproducibility among laboratories was 83.3%,95.6%and 86.7%.The sensitivity(true positive rate)and specificity(true negative rate)of the test were 89.9%and 90.9%,respectively.In summary,the test provides a novel alternative for pyrogen detection.
基金National Natural Science Foundation of China(No.42130707,42107382,42022049)Natural Science Foundation of Jiangsu Province(BK20200323).
文摘Carbon materials(e.g.,pyrogenic carbon(PyC))are widely used in agricultural soils and can participate in various biogeochemical processes,including iron(Fe)cycling.In soils,Fe (Ⅱ)species have been proposed as the main active contributor to produce reactive oxygen species(ROS),which are involved in various biogeochemical processes.However,the effects of PyC on the transformation of different Fe species in soils and the associated production of ROS are rarely investigated.This study examined the influence of PyC(pyrolyzed at 300-700℃)on Fe (Ⅱ)/Fe(Ⅲ)cycling and hydroxyl radical(·OH)production during redox fluctuations of paddy soils.Results showed that the reduction of Fe(Ⅲ)in soils was facilitated by PyC during anoxic incubation,which was ascribed to the increased abundance of dissimilatory Fe(Ⅲ)-reducing microorganisms(biotic reduction)and the electron exchange capacity of PyC(abiotic reduction).During oxygenation,PyC and higher soil pH promoted the oxidation of active Fe (Ⅱ)species(e.g.,exchangeable and low-crystalline Fe (Ⅱ)),which consequently induced higher yield of·OH and further led to degradation of imidacloprid and inactivation of soil microorganisms.Our results demonstrated that PyC accelerated Fe (Ⅱ)/Fe(Ⅲ)cycling and·OH production during redox fluctuations of paddy soils(especially those with low content of soil organic carbon),providing a new insight for remediation strategies in agricultural fields contaminated with organic pollutants.
基金We thank the Arctic Monitoring and Assessment Programme(AMAP)and the national programs in the circumpolar countries for their funding and support of this work.We are especially grateful to Simon Wilson,Cynthia de Wit,and the numerous reviewers that were a part of this process.We are thankful to the northern communities in circumpolar regions for their cooperation and collection of biological samples that yielded much of the data reviewed here.We also thank Canada's Northern Contaminants Program(NCP)for providing air data from the station of Alert and the Swedish Environmental Protection Agency and Finnish Meteorological Institute(FMI)for providing the air data for Pallas.
文摘Polycyclic aromatic hydrocarbons(PAHs)are large class of hydrophobic,semi-volatile organic contaminants that may enter the environment from both natural sources and anthropogenic activities.Pyrogenic PAHs arise from the incomplete combustion of fossil fuels and organic matter and following dispersal via long-range transport and may subsequently deposit in surface waters,soils and sediments of remote regions,including the Arctic.The current review summarizes and discusses Arctic data that is available for combustion-derived PAHs between 2004 and early 2018,focusing largely on data collected from remote,unexploited Arctic regions and from studies that provide some evidence of a pyrogenic origin.The increasing use of attribution ratios,which aid in discriminating PAHs from petrogenic or pyrogenic sources,suggest PAHs found in Arctic marine waters and sediment predominantly originate from natural underwater seeps,while those measured in air,freshwater,and terrestrial environments are likely to have originated from atmospheric and combustion-derived sources.Modeling efforts indicate that atmospheric PAHs in the Canadian and Norwegian Arctic are likely to have originated in the northern hemisphere e predominantly from Western Russia,northern Europe,and North America.East Asia appears to be a minor source of PAHs to the Arctic,despite contributing more than 50%of global PAH emissions.In comparison to the growing data for atmospheric PAHs,environmental data for these compounds in terrestrial and freshwater environments remain scarce.PAHs have been detected in Arctic biota from terrestrial,freshwater and marine environments,indicating exposure,however,levels are generally low,as most organisms efficiently metabolize parent PAHs.Globally,PAH emissions are expected to decline in the future,however models suggest the Arctic may not experience the same magnitude of decline projected for other world regions.Furthermore,future changes in climate may contribute to a re-volatilization of environmental PAHs,providing a source of secondary emissions to the Arctic atmosphere,emphasizing the importance of future monitoring for understanding the sources,fate and impacts of PAHs in the Arctic.
文摘To further evaluate the causality between endogenous pyrogen (EP)-induced fever andcyclic adenosine- 3’, 5’- monophosphate (cyclic AMP) level. the effects of sodium salicylate(SS) on the febrile response and increased levels of cyclic AMP in both cerebrospinal fluid(c.s.f.) and plasma during EP- induced fever in rabbits were observed. The results suggestthat cyclic AMP is probably involved in the central mediation of EP-induced fever and thatincreased concentration of cyclic AMP in c.s.f. associated with EP- induced fever is not theresult of temperature elevation but appears to be caused by the increased synthesis in the cen-tral nervous system. In addition it is confirmed that blood is impossibly a contributorysource of increased cyclic AMP in c.s.f. during EP fever, and that SS may act subsequentto the increase in cyclic AMP.
基金W.X.and Z.L.thank the National Science Foundation(NSF)CAREER award(CBET-1752220)for the financial supportThis work is also supported(in part)by the US Department of Defense,through the Strategic Environmental Research and Development Program(SERDP ER 19-1239)
文摘Pyrogenic Carbonaceous Matter(PCM;e.g.,black carbon,biochar,and activated carbon)are solid residues from incomplete combustion of fussil fuel or biomass.They are traditionally viewed as inert adsorbents for sequestering contaminants from the aqueous phase or providing surfaces for microbes to grow.In this account,we reviewed the recently discovered reactivity of PCM in promoting both chemical and microbial synergies that are important in pollutant transformation,biogeochemical processes of redox-active elements,and climate change mitigation with respect to the interaction between biochar and nitrous oxide(N2O).Moreover,we focused on our group's work in the PCM-enhanced abiotic transformation of nitrogenous and halogenated pollutants and conducted in-depth analysis of the reaction pathways.To understand what properties of PCM confer its reactivity,our group pioneered the use of PCM-like polymers,namely conjugated microporous polymers(CMPs),to mimic the performance of PCM.This approach allows for the controlled incorporation of specific surface properties(e.g.,quinones)into the polymer network during the polymer synthesis.As a result,the relationship between specific characteristics of PCM and its reactivity in facilitating the decay of a model pollutant was systematically studied in our group's work.The findings summarized in this account help us to better understand an overlooked environmental process where PCM synergistically interacts with various environmental reagents such as hydrogen sulfide and water.Moreover,the knowledge gained in these studies could inform the design of a new generation of reactive carbonaceous materials with tailored properties that are highly efficient in contaminant removal.
