Background:The present article questions the relative importance of local-and large-scale processes on the long-term dynamics of fire in the subalpine belt in the western Alps.The study is based on soil charcoal datin...Background:The present article questions the relative importance of local-and large-scale processes on the long-term dynamics of fire in the subalpine belt in the western Alps.The study is based on soil charcoal dating and identification,several study sites in contrasting environmental conditions,and sampling of soil charcoal along the elevation gradient of each site.Based on local differences in biomass combustion,we hypothesize that local-scale or landscape-scale processes have driven the fire history,while combustion homogeneity supports the hypothesis of the importance of large-scale or macro-ecological processes,especially climate.Results:Biomass burning during the Holocene resulted from the nesting effects of climate,land use,and altitude,but was little influenced by slope exposure(north versus south),soil(dryness,pH,depth),and vegetation.The mid-Holocene(6500–2700 cal BP)was an important period for climate-driven biomass burning in the subalpine ecosystems of the western Alps,while fires over the last 2500 years appear much more episodic,prompting us to speculate that human activity has played a vital role in their occurrence.Conclusion:Our working hypothesis that the strength of local drivers should offset the effects of regional climate is not validated.The homogeneity of the fire regime between sites thus underscores that climate was the main driver during the Holocene of the western Alps.Long-term subalpine fires are controlled by climate at the millennial scale.Local conditions matter for little in determining variability at the century scale.The mid-Holocene was a chief period for climatic biomass burning in the subalpine zone,while fires during the late Holocene appear much more episodic,suggesting that social drivers has exercised key function on their control.展开更多
Endotoxin detection is an important step in drug characterization. Herein we found that a chemotherapeutic drug nanoformulation composed of irinotecan hydrochloride(CPT-11) and an amphiphilic molecule DSPE-mPEG_(2000)...Endotoxin detection is an important step in drug characterization. Herein we found that a chemotherapeutic drug nanoformulation composed of irinotecan hydrochloride(CPT-11) and an amphiphilic molecule DSPE-mPEG_(2000) can interfere with the limulus amebocyte lysate assay(LAL). Furthermore, the rabbit pyrogen test(RPT) results indicated that at a relatively high dosage, the drug irinotecan hydrochloride can induce a hypothermia effect which may render the RPT results ambiguous in determination of the safety of the drug formulation.Our findings demonstrate limitations of endotoxin detection in micellar drugs,and call for the necessity of developing reliable endotoxin detection methods that can overcome the interference of nanomaterials in order to better ensure the drug safety of patients in future pharmaceutical drug development.展开更多
The chemical composition of unpleasant smell, emitted from the production process of wood-plastic composites using Manchurian ash sawdust （Fraxinus mandschurica Rupr.） and polypropylene powder as the raw material, w...The chemical composition of unpleasant smell, emitted from the production process of wood-plastic composites using Manchurian ash sawdust （Fraxinus mandschurica Rupr.） and polypropylene powder as the raw material, was investigated. Wood sawdust and polypropylene powder were subjected to heat treatment to 290℃ during 8 min （the conditions were similar to those employed on an industrial scale）. The emitted compounds were collected and analyzed by gas chromatography-mass spectrometry （GC-MS）. The analytical results showed that the unpleasant smell was emitted from the pyrogenation of wood sawdust rather than from the polypropylene powder. Nine types of compounds （hydrocarbons, ethers, phenols, aldehydes, ketones, alcohols, acids and their derivatives, furan and its derivatives, and nitrogen-containing compounds） were collected in the gas phase during heating. Among those 126 components detected by GC-MS, 112 compounds were identified.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
<strong>Introduction:</strong> Haemodialysis is the most well-established form of treatment for ESRD. <strong>Method:</strong> To evaluate the implementation of standard criteria in heamodialys...<strong>Introduction:</strong> Haemodialysis is the most well-established form of treatment for ESRD. <strong>Method:</strong> To evaluate the implementation of standard criteria in heamodialysis water treatment units in Sharkia governorate and to determine the weak points in application of standard criteria, and reach the optimal standards to improve pt. outcomes, across the sectional study was conducted at 30 heamodialysis units of Sharkia governorate, using a modified questionnaire was developed based on MOH protocol and international guidelines such as CARI guidelines, AAMI guidelines and others by the researchers. All data were collected, tabulated and statistically analyzed using SPSS 22.0 for windows (SPSS Inc., Chicago, IL, USA). <strong>Results:</strong> Of the 30 units, the majority more than 80% of the units achieved the infrastructure and schematic structure, contain water purification devices, good infection control policies, proper chemical disinfection, good monitoring and quality control, accepted maintenance technician evaluation and collected processed water samples results matched decree of 63 for 1996. <strong>Conclusion:</strong> Most of the studied units nearly fulfilled the standard specifications of both MOH and AAMI. Ensuring that water quality meets AAMI standards and recommendations will minimize patient exposure to potential contaminants such as chemical hazards and endotoxemia associated with the use of the treated water for HD.展开更多
The present study aims affinity between available concentrations of phosphorus, micronutrients (Cu, Zn and Mn) and stable carbon (SC) in archaeological black earth (ABE) from area “Ilha de Terra”/Caxiuanã—Par&...The present study aims affinity between available concentrations of phosphorus, micronutrients (Cu, Zn and Mn) and stable carbon (SC) in archaeological black earth (ABE) from area “Ilha de Terra”/Caxiuanã—Pará. The relevance of this study refers especially to the determination of carbon concentrations (total, oxidable and semi-labile carbon) directly associated with those of pyrogenic carbon, common in ABE, which should add their contributions to the understanding of soil organic matter recalcitrance. Chemical properties such as CEC and base saturation were determined for ABE and subjacent Latossoil. The available concentrations of nutrients were performed from sequential extraction F1 to F5 phases. Phosphorus was obtained by spectrophotometric method and micronutrients by MP-AES. TOC was determined by the combustion method;stable carbon was obtained from thermoxidation method CTO-375. The following results were obtained from ABE: CEC effective = 21 to 28 (cmolc·L<sup>-1</sup>);base saturation = 58% to 69%;Carbon concentrations (%): TOC = 2.95 to 3.94;SC = 0.25 to 0.88;semi-labile carbon = 1.75 to 3.63;oxidable = 2.11 to 3.65;inorganic carbon 0.01 to 0.38;P<sub>2</sub>O<sub>5</sub> concentrations (mg·kg<sup>-1</sup>) in the ABE phases F3 (Fe-Mn oxides, F4 (organic ) and F5 (residual)) in the following order: 35 to 65;200 to 400;140 to 230. It was concluded that the chemical properties in ABE from Ilha de Terra site fall within the range of fertile and the high concentrations of phosphorus are biogenic origin. Phases F3 and F4 are those considered nutrient stocks from ABE studied area.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
Artificial cerebrospinal fluid (c.s.f.) containing 40 mmol/L excess calcium was perfus-ed through the lateral ventricles of New Zealand white rabbits in order to reduce the Na^+/Ca^(++) ratio in the brain and the effe...Artificial cerebrospinal fluid (c.s.f.) containing 40 mmol/L excess calcium was perfus-ed through the lateral ventricles of New Zealand white rabbits in order to reduce the Na^+/Ca^(++) ratio in the brain and the effects on both the febrile response and adenosine cyclic mo-nophosphate (cAMP) concentration in plasma and c.s.f, during leucocytic pyrogen (LP)-induced fever were observed. The results showed that cAMP concentration in c.s.f, increas-ed significantly during LP-induced fever while the cAMP level in Plasma remained unchang-ed, and the perfusion of artificial c.s,f, containing 40 mmol/L excess calcium can signif-icantly inhibit not only the febrile response but also the increase in c.s.f, cAMP level,while there appears no effect on plasma cAMP concentration, thus demonstrating that theincrease of Na^+/Ca^(++) ratio causing the increase of cAMP content in the brain may be anessential link in the pathogenesis of LP-induced fever.展开更多
Ca2+ plays a pivotal role in the physiology and biochemistry of prokaryotic and mammalian organisms.Viruses also utilize the universal Ca2+ signal to create a specific cellular environment to achieve coexistence with ...Ca2+ plays a pivotal role in the physiology and biochemistry of prokaryotic and mammalian organisms.Viruses also utilize the universal Ca2+ signal to create a specific cellular environment to achieve coexistence with the host,and to propagate.In this paper we first describe our development of a grafting approach to understand site-specific Ca2+ binding properties of EF-hand proteins with a helix-loop-helix Ca2+ binding motif,then summarize our prediction and identification of EF-hand Ca2+ binding sites on a genome-wide scale in bacteria and virus,and next report the application of the grafting approach to probe the metal binding capability of predicted EF-hand motifs within the streptococcal hemoprotein receptor(Shr) of Streptococcus pyrogenes and the nonstructural protein 1(nsP1) of Sindbis virus.When methods such as the grafting approach are developed in conjunction with prediction algorithms we are better able to probe continuous Ca2+-binding sites that have been previously underrepresented due to the limitation of conventional methodology.展开更多
The herbicide diuron is widely used in agricultural areas in Brazil, whereas it has high potential for subsurface water contamination due to its physicochemical characteristics. Recent studies have demonstrated the po...The herbicide diuron is widely used in agricultural areas in Brazil, whereas it has high potential for subsurface water contamination due to its physicochemical characteristics. Recent studies have demonstrated the potential of biochar as a sorbent and possible pesticide leaching mitigation. The objective of this study was to investigate the long-term effect of biochar application on the kinetics of sorption and desorption of diuron in a Cerrado Haplic Plinthosol. Samples were collected in an experiment conducted in the field in a randomized block design consisting of the combination of two levels of fertilizer application (0 and 300 kg ha −1 of 5-25-15 formula of NPK fertilizers) and three doses of biochar (0, 16, and 32 Mg ha −1 ). The Freundlich isotherm accurately described the sorption of diuron in all treatments. Biochar application increased the sorption and reduced the desorption of diuron. This effect was attributed to the contribution of biochar to total organic carbon (C) and C in the humin fraction and to the increase in the reactivity of the humic acid and humin fractions, which was significantly highly correlated with the sorption coefficient ( K f ). A positive correlation between the partition coefficient of organic C and K f confirmed the importance of the soil organic compartment for the sorption of diuron. The higher diuron sorption and lower diuron desorption capacities of sandy soils after biochar application could reduce the potential risk of diuron leaching and contamination of subsurface water.展开更多
Biochar,possessing electron exchange capacities(EEC),is generally involved in environmental redox reactions due to the presence of redox-active moieties(RAMs).The phenomenon that chars containing comparable RAMs posse...Biochar,possessing electron exchange capacities(EEC),is generally involved in environmental redox reactions due to the presence of redox-active moieties(RAMs).The phenomenon that chars containing comparable RAMs possess differential EEC revealed that the accessibility of RAMs is important to the redox properties.However,many studies have focused on the type of RAMs,whereas the distribution has been insufficiently investigated.Herein,we achieved nanoscale observation of electroactive moieties on the surface of six chars using a conductive atomic force microscope.For the two specific kinds of chars with submicron particles and opposite current distributions,the submicron particles took up only 1-4‰wt of biochar accounting for approximately 30-50%of electron-donating capacity(EDC),and electron-accepting capacity(EAC)became 87%and 1.40 times as before after removing submicron particles,respectively.Meanwhile,the combined impact of RAMs and surface topography(that uneven distribution of RAMs resulted in outstanding EEC by enhancing accessibility)was clarified.Furthermore,direct evidence of the link between char structure and EEC(that condensed aromatic structures were indispensable to EAC while both heteroatoms and amorphous aromatics contributed to EDC)was established.These findings can aid in understanding the functions of biochar in biotic and abiotic redox processes.展开更多
Mn^3＋ and Bi^3＋ co-doped Y6WO12 samples with hexagonal structure were synthesized via an improved salt pyrogenation method at a temperature region of 700-1100 ℃ for 3 h. In Y6WO12, Mn^3＋, substituting y^3＋, occup...Mn^3＋ and Bi^3＋ co-doped Y6WO12 samples with hexagonal structure were synthesized via an improved salt pyrogenation method at a temperature region of 700-1100 ℃ for 3 h. In Y6WO12, Mn^3＋, substituting y^3＋, occupies a seven-coordination site and its energy levels are treated in near Oh symmetry. The samples doped by Mn^3＋ alone emit the most intensive blue light at 420 nm under excitation at 247 nm due to charge transition （CT）. The mechanism of sensitization of Bi^3＋ for Y6WO12：Mn^3＋ was also analyzed by taking account of metal-to-metal chargetransfer （MMCT） from Bi^3＋ to Mn^3＋. As a consequence, the phosphor Y6WO12：Mn^3＋/Bi^3＋ can emit blue light under radiation of 370 nm, and the emission intensity is enhanced about five times by the sensitizer Bi^3＋. The optimal doping concentration of Bi^3＋ is determined as 1 at% for the emission at 420 nm in Y6WO12：0.5 at% Mn^3＋ phosphors.展开更多
Biochar is a promising carbon dioxide removal(CDR)technology for climate change mitigation.Current procedures for its determination are lengthy,labor-intensive,and difficult to conduct.Benzene polycarboxylic acids(BPC...Biochar is a promising carbon dioxide removal(CDR)technology for climate change mitigation.Current procedures for its determination are lengthy,labor-intensive,and difficult to conduct.Benzene polycarboxylic acids(BPCA)are the most promising molecular markers for identification and quantification of biochar and its quality as they specifically represent the stable polyaromatic backbone of biochar.Therefore,using the BPCA method,its stability and,thus,its C sequestration potential could be used for CDR accounting.The current BPCA method relies on a specific high-pressure digestion apparatus,which is not available around the world.Therefore,the aims of the present work were(i)to compare the conventional high-pressure nitric acid oxidation with a microwave-assisted digestion technique and optimize the oxidation conditions in such a way that previous results are comparable with future ones,and(ii)to significantly reduce the digestion time of soil samples of 8 h and to develop a suitable routine method that produces comparable and reproducible results.For this purpose,soil and control sample series were prepared for different temperature-time-program.Obtained results were compared with the values of the conventional method both for individual samples and for the whole dataset separately.To ensure the representative-ness of the results,in addition to various soil samples with different properties,we included two reference materials into our data set,one without biochar(wheat flour)and a biochar sample.Our results showed that conventional nitric acid oxidation in the BPCA determination at 170°C and 8 h can be substituted by digestion in a microwave reaction system(CEM Mars6)at 190°C and 1 h.Our results further showed that this condition needs to be strictly matched,because,otherwise,over-or underestimation of biochar quantity and/or quality will be the consequence.The goal of a less time-consuming BPCA extrac-tion from soil samples was achieved by reducing the extraction time from 8 to 1 h using the microwave-assisted method.However,one disadvantage of the new method is that five times more sample material and chemicals are needed for further BPCA analysis,compared to the original method.展开更多
OBJECTIVE:To investigate anti-endotoxin action of four OAs reacted with endotoxin by the LAL assay with KTA.METHODS:Using a incubating kinetic tube reader and kinetic turbidimetric assay(KTA),the concentration-respons...OBJECTIVE:To investigate anti-endotoxin action of four OAs reacted with endotoxin by the LAL assay with KTA.METHODS:Using a incubating kinetic tube reader and kinetic turbidimetric assay(KTA),the concentration-response time curve of endotoxin reacted with limulus amebocyte lysate(LAL) at 37℃ were obtained and the action of four organic acids(OAs) on it were investigated.The four OAs were benzoic acid,salicylic acid,syringic acid and 2-amino-benzoic acid from Radix isatidis.Meanwhile,the temperature variation caused by endotoxin with the four OAs was studied by the rabbit pyrogen test(RPT).RESULTS:It was showed that a low concentration(1 mg/mL) of the four OAs had a little effect of anti-endotoxin,and when the concentrations of the four OAs were 30 mg/mL,the endotoxin was neutralized completely.The relationships between the concentrations of endotoxin and the OAs were all linear with correlation coefficients of greater than 0.9995,indicating that the four OAs all had strong anti-endotoxin action,while syringic acid had the strongest action among the four OAs with IC50 of 12.84 mg/mL.CONCLUSION:The investigations of KTA agreed well with the results obtained by means of RPT.展开更多
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
基金Financial support was provided to C.C.through a French incentive action fund from the Institut National des Sciences de l’Univers(INSU ACI ECCO)by an ARTEMIS grant for datings(PALEOFIRE program,INSU-CNRS,France).
文摘Background:The present article questions the relative importance of local-and large-scale processes on the long-term dynamics of fire in the subalpine belt in the western Alps.The study is based on soil charcoal dating and identification,several study sites in contrasting environmental conditions,and sampling of soil charcoal along the elevation gradient of each site.Based on local differences in biomass combustion,we hypothesize that local-scale or landscape-scale processes have driven the fire history,while combustion homogeneity supports the hypothesis of the importance of large-scale or macro-ecological processes,especially climate.Results:Biomass burning during the Holocene resulted from the nesting effects of climate,land use,and altitude,but was little influenced by slope exposure(north versus south),soil(dryness,pH,depth),and vegetation.The mid-Holocene(6500–2700 cal BP)was an important period for climate-driven biomass burning in the subalpine ecosystems of the western Alps,while fires over the last 2500 years appear much more episodic,prompting us to speculate that human activity has played a vital role in their occurrence.Conclusion:Our working hypothesis that the strength of local drivers should offset the effects of regional climate is not validated.The homogeneity of the fire regime between sites thus underscores that climate was the main driver during the Holocene of the western Alps.Long-term subalpine fires are controlled by climate at the millennial scale.Local conditions matter for little in determining variability at the century scale.The mid-Holocene was a chief period for climatic biomass burning in the subalpine zone,while fires during the late Holocene appear much more episodic,suggesting that social drivers has exercised key function on their control.
基金supported by the National Natural Science Foundation of China [Grant No. 31600812]Strategic Priority Research Program of the Chinese Academy of Sciences [Grant No. XDA09030301]+1 种基金Natural Science Foundation Key Project [Grant No. 31630027, 31430031]the National Distinguished Young Scholars Grant [Grant No. 31225009]
文摘Endotoxin detection is an important step in drug characterization. Herein we found that a chemotherapeutic drug nanoformulation composed of irinotecan hydrochloride(CPT-11) and an amphiphilic molecule DSPE-mPEG_(2000) can interfere with the limulus amebocyte lysate assay(LAL). Furthermore, the rabbit pyrogen test(RPT) results indicated that at a relatively high dosage, the drug irinotecan hydrochloride can induce a hypothermia effect which may render the RPT results ambiguous in determination of the safety of the drug formulation.Our findings demonstrate limitations of endotoxin detection in micellar drugs,and call for the necessity of developing reliable endotoxin detection methods that can overcome the interference of nanomaterials in order to better ensure the drug safety of patients in future pharmaceutical drug development.
文摘The chemical composition of unpleasant smell, emitted from the production process of wood-plastic composites using Manchurian ash sawdust （Fraxinus mandschurica Rupr.） and polypropylene powder as the raw material, was investigated. Wood sawdust and polypropylene powder were subjected to heat treatment to 290℃ during 8 min （the conditions were similar to those employed on an industrial scale）. The emitted compounds were collected and analyzed by gas chromatography-mass spectrometry （GC-MS）. The analytical results showed that the unpleasant smell was emitted from the pyrogenation of wood sawdust rather than from the polypropylene powder. Nine types of compounds （hydrocarbons, ethers, phenols, aldehydes, ketones, alcohols, acids and their derivatives, furan and its derivatives, and nitrogen-containing compounds） were collected in the gas phase during heating. Among those 126 components detected by GC-MS, 112 compounds were identified.
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.
文摘<strong>Introduction:</strong> Haemodialysis is the most well-established form of treatment for ESRD. <strong>Method:</strong> To evaluate the implementation of standard criteria in heamodialysis water treatment units in Sharkia governorate and to determine the weak points in application of standard criteria, and reach the optimal standards to improve pt. outcomes, across the sectional study was conducted at 30 heamodialysis units of Sharkia governorate, using a modified questionnaire was developed based on MOH protocol and international guidelines such as CARI guidelines, AAMI guidelines and others by the researchers. All data were collected, tabulated and statistically analyzed using SPSS 22.0 for windows (SPSS Inc., Chicago, IL, USA). <strong>Results:</strong> Of the 30 units, the majority more than 80% of the units achieved the infrastructure and schematic structure, contain water purification devices, good infection control policies, proper chemical disinfection, good monitoring and quality control, accepted maintenance technician evaluation and collected processed water samples results matched decree of 63 for 1996. <strong>Conclusion:</strong> Most of the studied units nearly fulfilled the standard specifications of both MOH and AAMI. Ensuring that water quality meets AAMI standards and recommendations will minimize patient exposure to potential contaminants such as chemical hazards and endotoxemia associated with the use of the treated water for HD.
文摘The present study aims affinity between available concentrations of phosphorus, micronutrients (Cu, Zn and Mn) and stable carbon (SC) in archaeological black earth (ABE) from area “Ilha de Terra”/Caxiuanã—Pará. The relevance of this study refers especially to the determination of carbon concentrations (total, oxidable and semi-labile carbon) directly associated with those of pyrogenic carbon, common in ABE, which should add their contributions to the understanding of soil organic matter recalcitrance. Chemical properties such as CEC and base saturation were determined for ABE and subjacent Latossoil. The available concentrations of nutrients were performed from sequential extraction F1 to F5 phases. Phosphorus was obtained by spectrophotometric method and micronutrients by MP-AES. TOC was determined by the combustion method;stable carbon was obtained from thermoxidation method CTO-375. The following results were obtained from ABE: CEC effective = 21 to 28 (cmolc·L<sup>-1</sup>);base saturation = 58% to 69%;Carbon concentrations (%): TOC = 2.95 to 3.94;SC = 0.25 to 0.88;semi-labile carbon = 1.75 to 3.63;oxidable = 2.11 to 3.65;inorganic carbon 0.01 to 0.38;P<sub>2</sub>O<sub>5</sub> concentrations (mg·kg<sup>-1</sup>) in the ABE phases F3 (Fe-Mn oxides, F4 (organic ) and F5 (residual)) in the following order: 35 to 65;200 to 400;140 to 230. It was concluded that the chemical properties in ABE from Ilha de Terra site fall within the range of fertile and the high concentrations of phosphorus are biogenic origin. Phases F3 and F4 are those considered nutrient stocks from ABE studied area.
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Artificial cerebrospinal fluid (c.s.f.) containing 40 mmol/L excess calcium was perfus-ed through the lateral ventricles of New Zealand white rabbits in order to reduce the Na^+/Ca^(++) ratio in the brain and the effects on both the febrile response and adenosine cyclic mo-nophosphate (cAMP) concentration in plasma and c.s.f, during leucocytic pyrogen (LP)-induced fever were observed. The results showed that cAMP concentration in c.s.f, increas-ed significantly during LP-induced fever while the cAMP level in Plasma remained unchang-ed, and the perfusion of artificial c.s,f, containing 40 mmol/L excess calcium can signif-icantly inhibit not only the febrile response but also the increase in c.s.f, cAMP level,while there appears no effect on plasma cAMP concentration, thus demonstrating that theincrease of Na^+/Ca^(++) ratio causing the increase of cAMP content in the brain may be anessential link in the pathogenesis of LP-induced fever.
文摘Ca2+ plays a pivotal role in the physiology and biochemistry of prokaryotic and mammalian organisms.Viruses also utilize the universal Ca2+ signal to create a specific cellular environment to achieve coexistence with the host,and to propagate.In this paper we first describe our development of a grafting approach to understand site-specific Ca2+ binding properties of EF-hand proteins with a helix-loop-helix Ca2+ binding motif,then summarize our prediction and identification of EF-hand Ca2+ binding sites on a genome-wide scale in bacteria and virus,and next report the application of the grafting approach to probe the metal binding capability of predicted EF-hand motifs within the streptococcal hemoprotein receptor(Shr) of Streptococcus pyrogenes and the nonstructural protein 1(nsP1) of Sindbis virus.When methods such as the grafting approach are developed in conjunction with prediction algorithms we are better able to probe continuous Ca2+-binding sites that have been previously underrepresented due to the limitation of conventional methodology.
基金the Brazilian Council of Science and Technology(Conselho Nacional de Desenvolvimento Científico e Tecnologico-CNPq)for financial support for the Biochar project(No.CNPq 471205220133)
文摘The herbicide diuron is widely used in agricultural areas in Brazil, whereas it has high potential for subsurface water contamination due to its physicochemical characteristics. Recent studies have demonstrated the potential of biochar as a sorbent and possible pesticide leaching mitigation. The objective of this study was to investigate the long-term effect of biochar application on the kinetics of sorption and desorption of diuron in a Cerrado Haplic Plinthosol. Samples were collected in an experiment conducted in the field in a randomized block design consisting of the combination of two levels of fertilizer application (0 and 300 kg ha −1 of 5-25-15 formula of NPK fertilizers) and three doses of biochar (0, 16, and 32 Mg ha −1 ). The Freundlich isotherm accurately described the sorption of diuron in all treatments. Biochar application increased the sorption and reduced the desorption of diuron. This effect was attributed to the contribution of biochar to total organic carbon (C) and C in the humin fraction and to the increase in the reactivity of the humic acid and humin fractions, which was significantly highly correlated with the sorption coefficient ( K f ). A positive correlation between the partition coefficient of organic C and K f confirmed the importance of the soil organic compartment for the sorption of diuron. The higher diuron sorption and lower diuron desorption capacities of sandy soils after biochar application could reduce the potential risk of diuron leaching and contamination of subsurface water.
基金the National Key Research&Development Program from Ministry of Science and Technology of China[Grant Number 2018YFD1100600]the Key Research&Development Program from Science Technology Department of Zhejiang Province[2021C03024].
文摘Biochar,possessing electron exchange capacities(EEC),is generally involved in environmental redox reactions due to the presence of redox-active moieties(RAMs).The phenomenon that chars containing comparable RAMs possess differential EEC revealed that the accessibility of RAMs is important to the redox properties.However,many studies have focused on the type of RAMs,whereas the distribution has been insufficiently investigated.Herein,we achieved nanoscale observation of electroactive moieties on the surface of six chars using a conductive atomic force microscope.For the two specific kinds of chars with submicron particles and opposite current distributions,the submicron particles took up only 1-4‰wt of biochar accounting for approximately 30-50%of electron-donating capacity(EDC),and electron-accepting capacity(EAC)became 87%and 1.40 times as before after removing submicron particles,respectively.Meanwhile,the combined impact of RAMs and surface topography(that uneven distribution of RAMs resulted in outstanding EEC by enhancing accessibility)was clarified.Furthermore,direct evidence of the link between char structure and EEC(that condensed aromatic structures were indispensable to EAC while both heteroatoms and amorphous aromatics contributed to EDC)was established.These findings can aid in understanding the functions of biochar in biotic and abiotic redox processes.
基金financially supported by the National Natural Science Foundation of China (Nos. 51401130 and 51704064)Program for Liaoning Innovative Research Team in University (No. LT2015020)+2 种基金Hebei Province Higher Education Science and Technology Research Project (No. ZD2017309)Scientific and Technological Research and Development Plan of Qinhuangdao City (No. 201701B063)Northeastern University at Qinhuangdao Campus Research Fund (No. XNK201602)
文摘Mn^3＋ and Bi^3＋ co-doped Y6WO12 samples with hexagonal structure were synthesized via an improved salt pyrogenation method at a temperature region of 700-1100 ℃ for 3 h. In Y6WO12, Mn^3＋, substituting y^3＋, occupies a seven-coordination site and its energy levels are treated in near Oh symmetry. The samples doped by Mn^3＋ alone emit the most intensive blue light at 420 nm under excitation at 247 nm due to charge transition （CT）. The mechanism of sensitization of Bi^3＋ for Y6WO12：Mn^3＋ was also analyzed by taking account of metal-to-metal chargetransfer （MMCT） from Bi^3＋ to Mn^3＋. As a consequence, the phosphor Y6WO12：Mn^3＋/Bi^3＋ can emit blue light under radiation of 370 nm, and the emission intensity is enhanced about five times by the sensitizer Bi^3＋. The optimal doping concentration of Bi^3＋ is determined as 1 at% for the emission at 420 nm in Y6WO12：0.5 at% Mn^3＋ phosphors.
基金provided by Martin Luther University Halle-Wittenberg,Germany.
文摘Biochar is a promising carbon dioxide removal(CDR)technology for climate change mitigation.Current procedures for its determination are lengthy,labor-intensive,and difficult to conduct.Benzene polycarboxylic acids(BPCA)are the most promising molecular markers for identification and quantification of biochar and its quality as they specifically represent the stable polyaromatic backbone of biochar.Therefore,using the BPCA method,its stability and,thus,its C sequestration potential could be used for CDR accounting.The current BPCA method relies on a specific high-pressure digestion apparatus,which is not available around the world.Therefore,the aims of the present work were(i)to compare the conventional high-pressure nitric acid oxidation with a microwave-assisted digestion technique and optimize the oxidation conditions in such a way that previous results are comparable with future ones,and(ii)to significantly reduce the digestion time of soil samples of 8 h and to develop a suitable routine method that produces comparable and reproducible results.For this purpose,soil and control sample series were prepared for different temperature-time-program.Obtained results were compared with the values of the conventional method both for individual samples and for the whole dataset separately.To ensure the representative-ness of the results,in addition to various soil samples with different properties,we included two reference materials into our data set,one without biochar(wheat flour)and a biochar sample.Our results showed that conventional nitric acid oxidation in the BPCA determination at 170°C and 8 h can be substituted by digestion in a microwave reaction system(CEM Mars6)at 190°C and 1 h.Our results further showed that this condition needs to be strictly matched,because,otherwise,over-or underestimation of biochar quantity and/or quality will be the consequence.The goal of a less time-consuming BPCA extrac-tion from soil samples was achieved by reducing the extraction time from 8 to 1 h using the microwave-assisted method.However,one disadvantage of the new method is that five times more sample material and chemicals are needed for further BPCA analysis,compared to the original method.
基金support of Nova of Beijing science and Technology (No. 2010B108)National Natural Science Fond (No. 30701091)
文摘OBJECTIVE:To investigate anti-endotoxin action of four OAs reacted with endotoxin by the LAL assay with KTA.METHODS:Using a incubating kinetic tube reader and kinetic turbidimetric assay(KTA),the concentration-response time curve of endotoxin reacted with limulus amebocyte lysate(LAL) at 37℃ were obtained and the action of four organic acids(OAs) on it were investigated.The four OAs were benzoic acid,salicylic acid,syringic acid and 2-amino-benzoic acid from Radix isatidis.Meanwhile,the temperature variation caused by endotoxin with the four OAs was studied by the rabbit pyrogen test(RPT).RESULTS:It was showed that a low concentration(1 mg/mL) of the four OAs had a little effect of anti-endotoxin,and when the concentrations of the four OAs were 30 mg/mL,the endotoxin was neutralized completely.The relationships between the concentrations of endotoxin and the OAs were all linear with correlation coefficients of greater than 0.9995,indicating that the four OAs all had strong anti-endotoxin action,while syringic acid had the strongest action among the four OAs with IC50 of 12.84 mg/mL.CONCLUSION:The investigations of KTA agreed well with the results obtained by means of RPT.
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.
