Objectives:This scoping review aims to methodically identify and analyse the determinants which influence maternal mortality and healthcare utilization in women of childbearing years in Nigeria.The review specifically...Objectives:This scoping review aims to methodically identify and analyse the determinants which influence maternal mortality and healthcare utilization in women of childbearing years in Nigeria.The review specifically addresses the difficulties faced in assessing medical care,and the ongoing initiatives to lower the maternal mortality ratio.Methods:Primary studies(published after year 2000)focused on maternal mortality,health determinants,and the utilization of maternal healthcare services in Nigeria were retrieved following a systematic search across multiple databases,including Scopus,PubMed,Google Scholar,and Web of Science.These were screened using defined inclusion and exclusion criteria.Data from these studies were extracted and thematically analysed to identify common themes and trends.Results:A total of 21 publications were included in this review comprising 2 qualitative,17 quantitative,and2 mixed study designs.Major health determinants identified in these studies include hypertensive disorders of pregnancy,haemorrhage,and sepsis/septicaemia,contributing as much as 29%,24%,and 14.2%of maternal deaths respectively in over 10%of the reviewed studies.Similarly,social-economic determinants including poverty,maternal education,health system issues and culture significantly impacted the utilization of maternal healthcare services,inadvertently impacting maternal mortality.Despite various maternal health interventions such as the"Abiye"Safe Motherhood Initiative,the Integrated Maternal,Newborn,and Child Health Strategy and strengthening emergency obstetric care by governmental and non-governmental agencies,early childbearing,unemployment,large family sizes,and dependence on male spouses continued to result in suboptimal utilization of services and adverse maternal outcomes.Conclusion:This scoping review comprehensively integrated existing data from published studies to provide a detailed picture of maternal mortality,its health determinants,and factors influencing care utilization among women of childbearing age in Nigeria and approaches to reduce maternal mortality in the country and possibly in the West African sub-region.展开更多
Although inductively coupled plasma mass spectrometry(ICP-MS) retains high sensitivity and has been intensively used for the measurement of ^(99)Tc, it usually suffers from tedious, expensive, and timeconsuming sample...Although inductively coupled plasma mass spectrometry(ICP-MS) retains high sensitivity and has been intensively used for the measurement of ^(99)Tc, it usually suffers from tedious, expensive, and timeconsuming sample pretreatments due to the isobaric interferences from ^(99)Ru and ^(98)Mo^(1)H. Herein, capillary electrophoresis(CE) was applied as sample introduction system for the sensitive, and interferencefree determination of ^(99)TcO_(4)^(-) from RuO_(4)^(-), and MoO_(4)^(2-) by ICP-MS with a simple sample treatment. Compared to the conventional methods, the hyphenated CE-ICP-MS avoids the use of expensive separation resins and reduces the consumption of mineral acid, representing a simpler, more efficient and environmentally benign approach. Moreover, the proposed method exhibits higher accuracy compared with the mathematical correction method using the natural isotope ratio of ^(99)Ru and ^(101)Ru, and significantly reduces sample consumption and the amount of waste, thus remarkably alleviating the radioactive exposure to operators and the pressure of radioactive waste treatment. Under the optimized conditions, the detection limits of 25 μg/L and 0.06 μg/L were obtained for RuO_(4)^(-) and ReO_(4)^(-)(Tc was replaced by Re), respectively, with relative standard deviation(RSD) lower than 5%. In addition, efficient recoveries of RuO_(4)^(-),ReO_(4)^(-),and ^(99)TcO_(4)^(-) from simulated Hanford site groundwater were achieved. The method is expected to be a promising candidate for sensitive and accurate analysis of ^(99)Tc from contaminated environmental samples.展开更多
The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fi...The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization.展开更多
Background: Erectile dysfunction (ED) is a common, bothersome and relatively under diagnosed complication of diabetes mellitus. This study was aimed to determine the prevalence of erectile dysfunction and its determin...Background: Erectile dysfunction (ED) is a common, bothersome and relatively under diagnosed complication of diabetes mellitus. This study was aimed to determine the prevalence of erectile dysfunction and its determinants. Methods: A cross-sectional hospital-based study was carried out in the Diabetology Units of the Buea and Limbe Regional Hospitals involving 332 male patients with diabetes and aged over 21 years. Data was analyzed using Stata and R version 3.5.3. Results: The mean age of the participants was 55years. Most participants (64.46%) were married. About half (50.60%) of the participants actively consumed alcohol, 11.45% were smokers and 57.83% were sedentary. 18 participants (5.42%) recorded high risk sexual behaviour. 54.32% of participants had a comorbidity and 43.90% were overweight. The prevalence of diabetic ED was 78.92%. Age, Fasting Blood Sugar and Glycated hemoglobin were found to be positive determinants of diabetic ED (odds ratio (OR) = 0.77, 95% CI −0.1 - 0.07). Conclusion: The prevalence of diabetic ED in this hospital population study is high, and both physician and patient—initiated measures are needed to reduce this prevalence and improve awareness, recognition and care of this condition.展开更多
Background: Social determinants of health (SDOH) significantly influence diseases with environmental components, like vector-borne parasitic diseases. This study aims to examine how these factors influence vector-born...Background: Social determinants of health (SDOH) significantly influence diseases with environmental components, like vector-borne parasitic diseases. This study aims to examine how these factors influence vector-borne parasitic diseases (VBPDs) transmission in Chad and provide recommendations for policy improvements. Methods: The study adopts the WHO Conceptual Framework of SDOH to compare two regions in Southern Chad: Kouh-Est, which has an ongoing vector control program, and Grand-Sido, which lacks such a program. The study includes both nomadic and sedentary populations to provide a comprehensive understanding of the SDOH influencing VBPDs. Households were randomly selected. Data on sociodemographic characteristics, literacy, knowledge of VBPDs and protective measures, and access to education and health facilities were collected. Results: A total of 202 households from 17 villages, including 820 participants, were surveyed. Agriculture, livestock, and fishing were the main occupations, involving 84.1% of participants. Literacy was low, with 36.7% non-educated, 47.7% completing primary school, 14.5% secondary school, and only 0.3% reaching tertiary education. Most villages lacked schools beyond the primary level, and nomadic populations were significantly less educated than sedentary ones (p Conclusion: Educational deficiencies, lack of protective measures against vectors, inadequate healthcare resources, and lifestyle conditions aggravated by poor road infrastructure, limited transportation, and economic constraints contribute to worsened VBPDs outcomes in these rural populations. Addressing these systemic issues in the surveyed communities is essential for improving health equity and VBPDs outcomes in these regions specifically and in similar populations settings more broadly.展开更多
Fenton/Fenton-like reactions have gained popularity for their remarkable proficiency in decomposing organic pollutants,especially when enhanced by reductants addition for accel-erating the Fe2+regeneration.Nevertheles...Fenton/Fenton-like reactions have gained popularity for their remarkable proficiency in decomposing organic pollutants,especially when enhanced by reductants addition for accel-erating the Fe2+regeneration.Nevertheless,these works predominantly centered on the formation and utilization of hydroxyl radicals(•OH)in the process,neglecting the evolution of oxidant and reductant due to the difficulty in the simultaneous determination of these two components.By employing the quenching-iodometric method,we could simultaneously determine the concentrations of HSO_(3)-and peroxydisulfate(PDS).This method first employed an excess of peroxymonosulfate(PMS)to effectively quench HSO_(3)-,and then used the iodometric spectrophotometry to simultaneously determine the concentrations of PMS and PDS in the reaction system.Finally,through precise stoichiometric relationships,we could accurately calculate the concentration of HSO_(3)-.Based on this method,we achieved concentration measurements that,upon linear fitting,yielded a correlation coefficient(R^(2))surpassing 0.99,unequivocally affirming the method’s accuracy and trustworthiness.In this work,an innovation approach for determining the concentrations of HSO_(3)-(reductant)and PDS(oxidant)was explored.Additionally,the resilience of the method was verified across different pH levels and in the presence of diverse impurity ions.The results ensured precise concentration measure-ments in the real wastewater.This method was characterized by its simplicity,rapid analysis,and environmental friendliness,offering a newanalytical strategy for the determination of PDS and HSO_(3)-in environmental samples.The method enables more meticulous monitoring of chemical usage in water treatment,facilitating optimized dosing strategies and assessments of reductant-enhanced Fenton or Fenton-like system in water purification.展开更多
In paleoseismic research,defining the age of an event is relatively straightforward,but pinpointing its magnitude with precision is challenging.This difficulty primarily arises because physical parameters,such as rupt...In paleoseismic research,defining the age of an event is relatively straightforward,but pinpointing its magnitude with precision is challenging.This difficulty primarily arises because physical parameters,such as rupture area and displacement,which are intimately linked to the seismic moment,are hard to derive from paleoseismic studies.Our preceding study identified two earthquake sites in Huoshan and Guzhen,Anhui Province.While we qualitatively described the timing of these occurrences and the characteristics of sand veins,dislocations,and earthquake-induced cracks,we did not provide quantitative estimates of their magnitude or seismogenic faults.Consequently,these findings were insufficient for assessing regional seismic risks or determining the potential magnitude of specific faults.This study employs two empirical relationships:one between the farthest distribution distance based on liquefaction from earthquake-induced events and magnitude,and the other concerning the intensityepicenter distance-magnitude relationship.Through these relationships,we analyze the sandy soil liquefaction and earthquake-induced cracks quantitatively.The analysis includes magnitude estimation and seismogenic fault evaluation for the sandy soil liquefaction and crack remnants of the Huoshan Daijiayuan earthquake,as well as the dislocation and crack remnants of the Guzhen Gaixia earthquake.The findings indicate that the Huoshan Daijiayuan site records two paleoseismic events.The first event transpired after 850 BC,and the second after 550 BC,with a gap of approximately 300 years between them;both had a seismic magnitude(M_(S))of around 6.0.The likely seismogenic fault for the Huoshan Daijiayuan earthquake is the Luoerling-Tudiling fault.Meanwhile,the paleoseismic site in Guzhen Gaixia documents two seismic events occurring during 2350-2050 BC,both with a seismic magnitude(MS)of approximately 6½.The Tancheng-Lujiang fault zone is likely the seismogenic fault associated with the Guzhen Gaixia earthquake site.展开更多
[Objective] This study was conducted to isolate and screen new Bacillus thuringiensis （Bt） strains against Lepidoptera insecticides. [Method] Bt strains were isolated from soil of Changbai Mountain area by temperatu...[Objective] This study was conducted to isolate and screen new Bacillus thuringiensis （Bt） strains against Lepidoptera insecticides. [Method] Bt strains were isolated from soil of Changbai Mountain area by temperature screening method, and highly-toxic Bt stains were then selected by biological determination and toxicity de- termination. [Result] From 150 soil samples, 18 Bt isolates were isolated, with an average isolation rate of 12.0%. Specifically, the isolation rate from mountain field was 8.5 %, and the isolation rate from farmland was 16.2%. The results of activity determination showed that there were17, 5 and 4 strains showing lethality rate over 90% against Plutel/a xylosrel/a, Spodoptera litura and Spodptera exigua, respectively, and among them, strain YNI-1 exhibited high activity against all the 3 kinds of in- sects. The results of toxicity determination showed that strain YNl-lhad the best fast-acting property against S.litura and S. exigua; strains with high toxicity against S. exigua were YN6-2〉YN1-1〉YN4-2〉YN2-6 sequentially; and toxicity of strains against S. /itura was in order of YN4-4〉YN1-1 〉YN6-1 〉YN4-1 〉YN2-1. [Conclusion] According to activity determination and toxicity determination, strain YN1-1 was screened as the target strain with wide spectrum, fast-acting property and high toxi- city.展开更多
Objective:A TLCS method was established for the determination of the content of Shenbei Beigua ointment,and the product quality of six samples from two formulations was evaluated.Methods:The determination method was t...Objective:A TLCS method was established for the determination of the content of Shenbei Beigua ointment,and the product quality of six samples from two formulations was evaluated.Methods:The determination method was thin-layer chromatography scanning(TLCS),using a developing solvent composed of ethyl acetate–methanol–strong ammonia water(17:2:1).The plates were heated at 105°C for 5 minutes,then sprayed with a mixture of dilute bismuth potassium iodide and 1%ferric chloride in ethanol(10:1),and scanned at a wavelength of 500 nm.Results:Peimine showed good linearity in the concentration range of 0.21–2.1μg with a correlation coefficient of r=0.9997,and Peiminine also exhibited good linearity in the same range with r=0.9995.The accuracy was≥95.0%,and the relative standard deviation(RSD)was≤5.0%(n=6).Conclusion:This method allows for the simultaneous determination of peimine and peiminine,providing a reliable reference for the quality control of the product.展开更多
Objective Data on homocysteine(Hcy) status and its determinants are limited among women during pregnancy and postpartum. This cross-sectional study aimed to investigate Hcy levels during pregnancy and postpartum, and ...Objective Data on homocysteine(Hcy) status and its determinants are limited among women during pregnancy and postpartum. This cross-sectional study aimed to investigate Hcy levels during pregnancy and postpartum, and to explore the determinants like geographic factor.Methods This study was conducted in women at mid-pregnancy, late-pregnancy and postpartum from southern, central and northern China. Approximately 132 women were included in each stratum by the three phases and regions. Plasma Hcy concentrations were assessed using high-performance liquid chromatography(HPLC), with hyperhomocysteinemia defined as > 10.0 μmol/L. Quantile regression was to estimate medians and interquartile ranges(IQRs), and logistic regression to examine the determinants of hyperhomocysteinemia.Results For 1,190 women included, the median(IQR) Hcy concentration was 5.66(4.62, 7.37) μmol/L.The adjusted median in mid-pregnancy, late-pregnancy and postpartum women was 4.75(4.13, 5.54),5.72(4.81, 6.85) and 7.09(5.65, 8.75) μmol/L, respectively, showing an increasing trend(P < 0.001). This increasing trend persisted across the three regions. Higher Hcy concentrations were observed in women residing in northern region and those with younger age or lower economic status. A total of 106(8.9%)women had hyperhomocysteinemia, with a higher prevalence in those residing in northern region(16.0%), or in postpartum women(16.5%).Conclusion Hcy levels, varying with geographic region, maternal age and economic status, are increased from mid-pregnancy to late-pregnancy and postpartum, indicating a need to monitor Hcy levels in pregnant and postpartum women to control potential risks related to elevated Hcy levels.展开更多
Here we complete our work on the asymptotics of Hankel determinants studying the case wherein the entries are “ultrarapidly”-varying functions in the sense that their logarithms are rapidly varying. Moreover, the la...Here we complete our work on the asymptotics of Hankel determinants studying the case wherein the entries are “ultrarapidly”-varying functions in the sense that their logarithms are rapidly varying. Moreover, the last results in the paper highlight analogies between algebraic identities for Hankelians with special entries and asymptotic relations valid for large classes of entries.展开更多
This study demonstrates the fabrication of mesoporous tungsten trioxide(WO_(3))-decorated flexible polyimide(PI)electrodes for the highly sensitive detection of catechol(CC)and hydroquinone(HQ),two environmental pollu...This study demonstrates the fabrication of mesoporous tungsten trioxide(WO_(3))-decorated flexible polyimide(PI)electrodes for the highly sensitive detection of catechol(CC)and hydroquinone(HQ),two environmental pollutants.Organic-inorganic composite dots are formed on flexible PI electrodes using evaporation-induced self-assembly(EISA)and electrospray methods.The EISA process is induced by a temperature gradient during electrospray,and the heated substrate partially decomposes the organic parts etched by O_(2) plasma,creating mesoporous structures.Differential pulse voltammetry and cyclic voltammetry demonstrate a linear correlation between analyte concentration and the electrochemical response.Computational studies support the spontaneous adsorption of CC and HQ molecules on model WO_(3) surfaces.The proposed sensor shows high sensitivity,a wide linear range,and a low detection limit for both individual and simultaneous determination of CC and HQ.Real sample analysis on river water confirms practical applicability.The WO_(3)-decorated PI electrode presents an efficient and reliable approach for detecting these pollutants,contributing to environmental safety measures.展开更多
Based on the Many Worlds Interpretation,I describe reality as a multilayer spacetime,where parallel layers play the role of alternative timelines.I link physics to ethics,arguing that one’s moral choices shape one’s...Based on the Many Worlds Interpretation,I describe reality as a multilayer spacetime,where parallel layers play the role of alternative timelines.I link physics to ethics,arguing that one’s moral choices shape one’s course in the multiverse.I consider one’s ethical decisions as decoherence events,leading to movement between alternative timelines,lighter(higher)or heavier(lower)realities.Sometimes in one’s curvilinear path in spacetime,one can even experience falling toward lower layers,slipping through wormholes.This theory supports free will and the simulation hypothesis.With this background,I explore the idea that a new theory of gravity might open new possibilities to shape matter and change our worldview through the invention of new technology,transforming information into waves and then into solid matter,paving the way for a new Multiverse Aeon for humanity.展开更多
Instantaneous Global Navigation Satellite System(GNSS)attitude determination method which achieves real-time attitude determination using GNSS signal has been extensively studied,particularly the one using a priori at...Instantaneous Global Navigation Satellite System(GNSS)attitude determination method which achieves real-time attitude determination using GNSS signal has been extensively studied,particularly the one using a priori attitude information replacing the code measurements to enhance the successful rate for ambiguity resolution.However,there exists a key limitation that this method relies on considerable Monte Carlo sampling particles to construct the pdf of ambiguities,resulting in significant computational burdens.To address this limitation,this paper provides a rapid single-epoch GNSS attitude determination method based on a priori attitude information.It utilizes a second-order Taylor expansion to analytically estimate the covariance of the baseline conditioned on a priori attitude information.This is followed by deriving the float solution and covariance of ambiguities,which are then processed using the standard LAMBDA method for integer ambiguity resolution.Experimental results demonstrate that our method is both efficient and accurate,significantly reducing computational costs compared to previous methods,thereby enhancing its applicability for GNSS-based attitude determination.展开更多
In the paper,a class of functions with bounded turnings involving cardioid domain,are studied in the region of the unit disc.The bounds of|a_(5)|,|a_(6)|,|a_(7)|and the fourth Hankel determinant are obtained,which are...In the paper,a class of functions with bounded turnings involving cardioid domain,are studied in the region of the unit disc.The bounds of|a_(5)|,|a_(6)|,|a_(7)|and the fourth Hankel determinant are obtained,which are more accurate than those obtained by Srivastava.展开更多
Objective To explore the health determinants of all-cancer mortality from a health-ecological perspective.Methods Using the health-ecological model,we identified 15 health determinants across five domains:personal inn...Objective To explore the health determinants of all-cancer mortality from a health-ecological perspective.Methods Using the health-ecological model,we identified 15 health determinants across five domains:personal innate,behavioral,interpersonal network,socioeconomic,and macroenvironmental characteristics.Data on cancer outcomes and health determinants from 185 countries,classified using the Human Development Index(HDI),were extracted from GLOBOCAN 2022,the World Health Organization Global Health Observatory,the Global Burden of Disease Study 2021,the United Nations,and the World Bank.A multivariate linear regression model was used to estimate the association between health determinants and cancer outcomes.Results A total of 153 countries with complete information on cancer outcomes and health determinants were enrolled in the study.A higher all-cancer age-standardized mortality rate(ASMR)was associated with current tobacco use,alcohol consumption,obesity,agricultural employment,and lag-distributed income.In women aged 15–49 years,being married or in a union was associated with a lower ASMR.Early-onset ASMR was positively associated with agricultural employment,lag-distributed income,and unsafe sanitation.Notable sex differences were observed,although tobacco use and obesity were identified as risk factors in both sexes.Conclusion We underscore the crucial need to incorporate cross-sectoral interventions within a resilient healthcare system to effectively mitigate the cancer mortality burden.展开更多
IPO underpricing,the tendency for newly issued shares to trade above their offer price on the first day,is a persistent global phenomenon.Empirical evidence suggests that U.S.IPOs averaged an 18.8%first-day return fro...IPO underpricing,the tendency for newly issued shares to trade above their offer price on the first day,is a persistent global phenomenon.Empirical evidence suggests that U.S.IPOs averaged an 18.8%first-day return from 1980 to 2001,imposing significant indirect costs on issuers.This paper reviews key explanations for underpricing,including information asymmetry,signaling,agency conflicts,and behavioral factors.Empirical research highlights firm characteristics,underwriter reputation,market conditions,and regulatory factors as major determinants.While underpricing facilitates liquidity and market participation,it also reflects inefficiencies.This study synthesizes theoretical perspectives and empirical findings,emphasizing the need for improved disclosure,governance,and regulatory oversight.展开更多
Nighttime navigation faces challenges from limited data and interference,especially when satellite signals are unavailable.Leveraging lunar polarized light,polarization navigation offers a promising solution for night...Nighttime navigation faces challenges from limited data and interference,especially when satellite signals are unavailable.Leveraging lunar polarized light,polarization navigation offers a promising solution for nighttime autonomous navigation.Current algorithms,however,are limited by the requirement for known horizontal attitudes,restricting applications.This study introduces an autonomous 3-D attitude determination method to overcome this limitation.Our approach utilizes the Angle of Polarization(AOP)at night to extract neutral points from the AOP pattern.This allows for the calculation of polarization meridian plane information for attitude determination.Subsequently,we present an optimized Polarization TRIAD(Pol-TRIAD)algorithm to acquire the 3-D attitude.The proposed method outperforms the existing approaches in outdoor experiments by achieving lower Root Mean Square Error(RMSE).For one baseline attitude,it improves pitch by 31.7%,roll by 21.7%,and yaw by 2.6%,while for the attitude with a larger tilt angle,the improvements are 64.4%,30.4%,and 9.1%,respectively.展开更多
文摘Objectives:This scoping review aims to methodically identify and analyse the determinants which influence maternal mortality and healthcare utilization in women of childbearing years in Nigeria.The review specifically addresses the difficulties faced in assessing medical care,and the ongoing initiatives to lower the maternal mortality ratio.Methods:Primary studies(published after year 2000)focused on maternal mortality,health determinants,and the utilization of maternal healthcare services in Nigeria were retrieved following a systematic search across multiple databases,including Scopus,PubMed,Google Scholar,and Web of Science.These were screened using defined inclusion and exclusion criteria.Data from these studies were extracted and thematically analysed to identify common themes and trends.Results:A total of 21 publications were included in this review comprising 2 qualitative,17 quantitative,and2 mixed study designs.Major health determinants identified in these studies include hypertensive disorders of pregnancy,haemorrhage,and sepsis/septicaemia,contributing as much as 29%,24%,and 14.2%of maternal deaths respectively in over 10%of the reviewed studies.Similarly,social-economic determinants including poverty,maternal education,health system issues and culture significantly impacted the utilization of maternal healthcare services,inadvertently impacting maternal mortality.Despite various maternal health interventions such as the"Abiye"Safe Motherhood Initiative,the Integrated Maternal,Newborn,and Child Health Strategy and strengthening emergency obstetric care by governmental and non-governmental agencies,early childbearing,unemployment,large family sizes,and dependence on male spouses continued to result in suboptimal utilization of services and adverse maternal outcomes.Conclusion:This scoping review comprehensively integrated existing data from published studies to provide a detailed picture of maternal mortality,its health determinants,and factors influencing care utilization among women of childbearing age in Nigeria and approaches to reduce maternal mortality in the country and possibly in the West African sub-region.
基金the National Natural Science Foundation of China (Nos. U1867205, 21622508, and 21575092)Study on Physical/Chemical Characteristics Related to the Migration of Key Nuclides under Simulated Disposal Conditions (Phase Ⅱ) (Contract No. KGES 2019(170), dated February 21, 2019.) for financial support。
文摘Although inductively coupled plasma mass spectrometry(ICP-MS) retains high sensitivity and has been intensively used for the measurement of ^(99)Tc, it usually suffers from tedious, expensive, and timeconsuming sample pretreatments due to the isobaric interferences from ^(99)Ru and ^(98)Mo^(1)H. Herein, capillary electrophoresis(CE) was applied as sample introduction system for the sensitive, and interferencefree determination of ^(99)TcO_(4)^(-) from RuO_(4)^(-), and MoO_(4)^(2-) by ICP-MS with a simple sample treatment. Compared to the conventional methods, the hyphenated CE-ICP-MS avoids the use of expensive separation resins and reduces the consumption of mineral acid, representing a simpler, more efficient and environmentally benign approach. Moreover, the proposed method exhibits higher accuracy compared with the mathematical correction method using the natural isotope ratio of ^(99)Ru and ^(101)Ru, and significantly reduces sample consumption and the amount of waste, thus remarkably alleviating the radioactive exposure to operators and the pressure of radioactive waste treatment. Under the optimized conditions, the detection limits of 25 μg/L and 0.06 μg/L were obtained for RuO_(4)^(-) and ReO_(4)^(-)(Tc was replaced by Re), respectively, with relative standard deviation(RSD) lower than 5%. In addition, efficient recoveries of RuO_(4)^(-),ReO_(4)^(-),and ^(99)TcO_(4)^(-) from simulated Hanford site groundwater were achieved. The method is expected to be a promising candidate for sensitive and accurate analysis of ^(99)Tc from contaminated environmental samples.
基金supported by the National Key R&D Program of China 2022YFB2404300the National Natural Science Foundation of China U22B2069the China Postdoctoral Science Foundation 2024M761006。
文摘The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization.
文摘Background: Erectile dysfunction (ED) is a common, bothersome and relatively under diagnosed complication of diabetes mellitus. This study was aimed to determine the prevalence of erectile dysfunction and its determinants. Methods: A cross-sectional hospital-based study was carried out in the Diabetology Units of the Buea and Limbe Regional Hospitals involving 332 male patients with diabetes and aged over 21 years. Data was analyzed using Stata and R version 3.5.3. Results: The mean age of the participants was 55years. Most participants (64.46%) were married. About half (50.60%) of the participants actively consumed alcohol, 11.45% were smokers and 57.83% were sedentary. 18 participants (5.42%) recorded high risk sexual behaviour. 54.32% of participants had a comorbidity and 43.90% were overweight. The prevalence of diabetic ED was 78.92%. Age, Fasting Blood Sugar and Glycated hemoglobin were found to be positive determinants of diabetic ED (odds ratio (OR) = 0.77, 95% CI −0.1 - 0.07). Conclusion: The prevalence of diabetic ED in this hospital population study is high, and both physician and patient—initiated measures are needed to reduce this prevalence and improve awareness, recognition and care of this condition.
文摘Background: Social determinants of health (SDOH) significantly influence diseases with environmental components, like vector-borne parasitic diseases. This study aims to examine how these factors influence vector-borne parasitic diseases (VBPDs) transmission in Chad and provide recommendations for policy improvements. Methods: The study adopts the WHO Conceptual Framework of SDOH to compare two regions in Southern Chad: Kouh-Est, which has an ongoing vector control program, and Grand-Sido, which lacks such a program. The study includes both nomadic and sedentary populations to provide a comprehensive understanding of the SDOH influencing VBPDs. Households were randomly selected. Data on sociodemographic characteristics, literacy, knowledge of VBPDs and protective measures, and access to education and health facilities were collected. Results: A total of 202 households from 17 villages, including 820 participants, were surveyed. Agriculture, livestock, and fishing were the main occupations, involving 84.1% of participants. Literacy was low, with 36.7% non-educated, 47.7% completing primary school, 14.5% secondary school, and only 0.3% reaching tertiary education. Most villages lacked schools beyond the primary level, and nomadic populations were significantly less educated than sedentary ones (p Conclusion: Educational deficiencies, lack of protective measures against vectors, inadequate healthcare resources, and lifestyle conditions aggravated by poor road infrastructure, limited transportation, and economic constraints contribute to worsened VBPDs outcomes in these rural populations. Addressing these systemic issues in the surveyed communities is essential for improving health equity and VBPDs outcomes in these regions specifically and in similar populations settings more broadly.
基金supported by National Natural Scienc Foundation of China(No.52400097)the Nanqiang Young Talents Supporting Program from Xiamen University.
文摘Fenton/Fenton-like reactions have gained popularity for their remarkable proficiency in decomposing organic pollutants,especially when enhanced by reductants addition for accel-erating the Fe2+regeneration.Nevertheless,these works predominantly centered on the formation and utilization of hydroxyl radicals(•OH)in the process,neglecting the evolution of oxidant and reductant due to the difficulty in the simultaneous determination of these two components.By employing the quenching-iodometric method,we could simultaneously determine the concentrations of HSO_(3)-and peroxydisulfate(PDS).This method first employed an excess of peroxymonosulfate(PMS)to effectively quench HSO_(3)-,and then used the iodometric spectrophotometry to simultaneously determine the concentrations of PMS and PDS in the reaction system.Finally,through precise stoichiometric relationships,we could accurately calculate the concentration of HSO_(3)-.Based on this method,we achieved concentration measurements that,upon linear fitting,yielded a correlation coefficient(R^(2))surpassing 0.99,unequivocally affirming the method’s accuracy and trustworthiness.In this work,an innovation approach for determining the concentrations of HSO_(3)-(reductant)and PDS(oxidant)was explored.Additionally,the resilience of the method was verified across different pH levels and in the presence of diverse impurity ions.The results ensured precise concentration measure-ments in the real wastewater.This method was characterized by its simplicity,rapid analysis,and environmental friendliness,offering a newanalytical strategy for the determination of PDS and HSO_(3)-in environmental samples.The method enables more meticulous monitoring of chemical usage in water treatment,facilitating optimized dosing strategies and assessments of reductant-enhanced Fenton or Fenton-like system in water purification.
基金supported by the Spark Program of Earthquake Sciences(No.XH23020YA)Joint Open Fund of Mengcheng National Geophysical Observatory(No.MEMGO-202411)Hefei government special technology research project(2024BFFFD02048).
文摘In paleoseismic research,defining the age of an event is relatively straightforward,but pinpointing its magnitude with precision is challenging.This difficulty primarily arises because physical parameters,such as rupture area and displacement,which are intimately linked to the seismic moment,are hard to derive from paleoseismic studies.Our preceding study identified two earthquake sites in Huoshan and Guzhen,Anhui Province.While we qualitatively described the timing of these occurrences and the characteristics of sand veins,dislocations,and earthquake-induced cracks,we did not provide quantitative estimates of their magnitude or seismogenic faults.Consequently,these findings were insufficient for assessing regional seismic risks or determining the potential magnitude of specific faults.This study employs two empirical relationships:one between the farthest distribution distance based on liquefaction from earthquake-induced events and magnitude,and the other concerning the intensityepicenter distance-magnitude relationship.Through these relationships,we analyze the sandy soil liquefaction and earthquake-induced cracks quantitatively.The analysis includes magnitude estimation and seismogenic fault evaluation for the sandy soil liquefaction and crack remnants of the Huoshan Daijiayuan earthquake,as well as the dislocation and crack remnants of the Guzhen Gaixia earthquake.The findings indicate that the Huoshan Daijiayuan site records two paleoseismic events.The first event transpired after 850 BC,and the second after 550 BC,with a gap of approximately 300 years between them;both had a seismic magnitude(M_(S))of around 6.0.The likely seismogenic fault for the Huoshan Daijiayuan earthquake is the Luoerling-Tudiling fault.Meanwhile,the paleoseismic site in Guzhen Gaixia documents two seismic events occurring during 2350-2050 BC,both with a seismic magnitude(MS)of approximately 6½.The Tancheng-Lujiang fault zone is likely the seismogenic fault associated with the Guzhen Gaixia earthquake site.
基金Supported by Natural Science Foundation of Yanbian University(2011-34)~~
文摘[Objective] This study was conducted to isolate and screen new Bacillus thuringiensis （Bt） strains against Lepidoptera insecticides. [Method] Bt strains were isolated from soil of Changbai Mountain area by temperature screening method, and highly-toxic Bt stains were then selected by biological determination and toxicity de- termination. [Result] From 150 soil samples, 18 Bt isolates were isolated, with an average isolation rate of 12.0%. Specifically, the isolation rate from mountain field was 8.5 %, and the isolation rate from farmland was 16.2%. The results of activity determination showed that there were17, 5 and 4 strains showing lethality rate over 90% against Plutel/a xylosrel/a, Spodoptera litura and Spodptera exigua, respectively, and among them, strain YNI-1 exhibited high activity against all the 3 kinds of in- sects. The results of toxicity determination showed that strain YNl-lhad the best fast-acting property against S.litura and S. exigua; strains with high toxicity against S. exigua were YN6-2〉YN1-1〉YN4-2〉YN2-6 sequentially; and toxicity of strains against S. /itura was in order of YN4-4〉YN1-1 〉YN6-1 〉YN4-1 〉YN2-1. [Conclusion] According to activity determination and toxicity determination, strain YN1-1 was screened as the target strain with wide spectrum, fast-acting property and high toxi- city.
文摘Objective:A TLCS method was established for the determination of the content of Shenbei Beigua ointment,and the product quality of six samples from two formulations was evaluated.Methods:The determination method was thin-layer chromatography scanning(TLCS),using a developing solvent composed of ethyl acetate–methanol–strong ammonia water(17:2:1).The plates were heated at 105°C for 5 minutes,then sprayed with a mixture of dilute bismuth potassium iodide and 1%ferric chloride in ethanol(10:1),and scanned at a wavelength of 500 nm.Results:Peimine showed good linearity in the concentration range of 0.21–2.1μg with a correlation coefficient of r=0.9997,and Peiminine also exhibited good linearity in the same range with r=0.9995.The accuracy was≥95.0%,and the relative standard deviation(RSD)was≤5.0%(n=6).Conclusion:This method allows for the simultaneous determination of peimine and peiminine,providing a reliable reference for the quality control of the product.
文摘Objective Data on homocysteine(Hcy) status and its determinants are limited among women during pregnancy and postpartum. This cross-sectional study aimed to investigate Hcy levels during pregnancy and postpartum, and to explore the determinants like geographic factor.Methods This study was conducted in women at mid-pregnancy, late-pregnancy and postpartum from southern, central and northern China. Approximately 132 women were included in each stratum by the three phases and regions. Plasma Hcy concentrations were assessed using high-performance liquid chromatography(HPLC), with hyperhomocysteinemia defined as > 10.0 μmol/L. Quantile regression was to estimate medians and interquartile ranges(IQRs), and logistic regression to examine the determinants of hyperhomocysteinemia.Results For 1,190 women included, the median(IQR) Hcy concentration was 5.66(4.62, 7.37) μmol/L.The adjusted median in mid-pregnancy, late-pregnancy and postpartum women was 4.75(4.13, 5.54),5.72(4.81, 6.85) and 7.09(5.65, 8.75) μmol/L, respectively, showing an increasing trend(P < 0.001). This increasing trend persisted across the three regions. Higher Hcy concentrations were observed in women residing in northern region and those with younger age or lower economic status. A total of 106(8.9%)women had hyperhomocysteinemia, with a higher prevalence in those residing in northern region(16.0%), or in postpartum women(16.5%).Conclusion Hcy levels, varying with geographic region, maternal age and economic status, are increased from mid-pregnancy to late-pregnancy and postpartum, indicating a need to monitor Hcy levels in pregnant and postpartum women to control potential risks related to elevated Hcy levels.
文摘Here we complete our work on the asymptotics of Hankel determinants studying the case wherein the entries are “ultrarapidly”-varying functions in the sense that their logarithms are rapidly varying. Moreover, the last results in the paper highlight analogies between algebraic identities for Hankelians with special entries and asymptotic relations valid for large classes of entries.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Education(RS-202300243390 and 2020R1A5A1018052)supported by the Basic Science Research Program through the National Research Foundation of Korea,funded by the Ministry of Education(2022R1A3B1078163)supported by the Technology Innovation Program(Publicprivate joint investment semiconductor R&D program[K-CHIPS])to foster high-quality human resources(RS-2023-00235484)funded by the Ministry of Trade,Industry&Energy(MOTIE,Korea)(1415187770)。
文摘This study demonstrates the fabrication of mesoporous tungsten trioxide(WO_(3))-decorated flexible polyimide(PI)electrodes for the highly sensitive detection of catechol(CC)and hydroquinone(HQ),two environmental pollutants.Organic-inorganic composite dots are formed on flexible PI electrodes using evaporation-induced self-assembly(EISA)and electrospray methods.The EISA process is induced by a temperature gradient during electrospray,and the heated substrate partially decomposes the organic parts etched by O_(2) plasma,creating mesoporous structures.Differential pulse voltammetry and cyclic voltammetry demonstrate a linear correlation between analyte concentration and the electrochemical response.Computational studies support the spontaneous adsorption of CC and HQ molecules on model WO_(3) surfaces.The proposed sensor shows high sensitivity,a wide linear range,and a low detection limit for both individual and simultaneous determination of CC and HQ.Real sample analysis on river water confirms practical applicability.The WO_(3)-decorated PI electrode presents an efficient and reliable approach for detecting these pollutants,contributing to environmental safety measures.
文摘Based on the Many Worlds Interpretation,I describe reality as a multilayer spacetime,where parallel layers play the role of alternative timelines.I link physics to ethics,arguing that one’s moral choices shape one’s course in the multiverse.I consider one’s ethical decisions as decoherence events,leading to movement between alternative timelines,lighter(higher)or heavier(lower)realities.Sometimes in one’s curvilinear path in spacetime,one can even experience falling toward lower layers,slipping through wormholes.This theory supports free will and the simulation hypothesis.With this background,I explore the idea that a new theory of gravity might open new possibilities to shape matter and change our worldview through the invention of new technology,transforming information into waves and then into solid matter,paving the way for a new Multiverse Aeon for humanity.
基金supported by the Research Grants Council of the Hong Kong Special Administrative Region,China(Nos.25202520,15214523)the Fundamental Research Funds for the Central Universities,China(No.YWF-22-L-805)。
文摘Instantaneous Global Navigation Satellite System(GNSS)attitude determination method which achieves real-time attitude determination using GNSS signal has been extensively studied,particularly the one using a priori attitude information replacing the code measurements to enhance the successful rate for ambiguity resolution.However,there exists a key limitation that this method relies on considerable Monte Carlo sampling particles to construct the pdf of ambiguities,resulting in significant computational burdens.To address this limitation,this paper provides a rapid single-epoch GNSS attitude determination method based on a priori attitude information.It utilizes a second-order Taylor expansion to analytically estimate the covariance of the baseline conditioned on a priori attitude information.This is followed by deriving the float solution and covariance of ambiguities,which are then processed using the standard LAMBDA method for integer ambiguity resolution.Experimental results demonstrate that our method is both efficient and accurate,significantly reducing computational costs compared to previous methods,thereby enhancing its applicability for GNSS-based attitude determination.
基金Supported by the Natural Science Foundation of Anhui Provincial Department of Education(Grant Nos.KJ2020A 0993KJ2020ZD74)+2 种基金the High-Level Talent Research Start-Up Project(Grant No.DC2300000286)the Foundation of Guangzhou Civil Aviation College(Grant Nos.22X041824X4412).
文摘In the paper,a class of functions with bounded turnings involving cardioid domain,are studied in the region of the unit disc.The bounds of|a_(5)|,|a_(6)|,|a_(7)|and the fourth Hankel determinant are obtained,which are more accurate than those obtained by Srivastava.
基金supported by the National Natural Science Foundation of China(No.82273722)Noncommunicable Chronic Diseases-National Science and Technology Major Project(2024ZD0520000)(2024ZD0520005)Central University Basic Research Fund of Peking Union Medical College(3332024216)。
文摘Objective To explore the health determinants of all-cancer mortality from a health-ecological perspective.Methods Using the health-ecological model,we identified 15 health determinants across five domains:personal innate,behavioral,interpersonal network,socioeconomic,and macroenvironmental characteristics.Data on cancer outcomes and health determinants from 185 countries,classified using the Human Development Index(HDI),were extracted from GLOBOCAN 2022,the World Health Organization Global Health Observatory,the Global Burden of Disease Study 2021,the United Nations,and the World Bank.A multivariate linear regression model was used to estimate the association between health determinants and cancer outcomes.Results A total of 153 countries with complete information on cancer outcomes and health determinants were enrolled in the study.A higher all-cancer age-standardized mortality rate(ASMR)was associated with current tobacco use,alcohol consumption,obesity,agricultural employment,and lag-distributed income.In women aged 15–49 years,being married or in a union was associated with a lower ASMR.Early-onset ASMR was positively associated with agricultural employment,lag-distributed income,and unsafe sanitation.Notable sex differences were observed,although tobacco use and obesity were identified as risk factors in both sexes.Conclusion We underscore the crucial need to incorporate cross-sectoral interventions within a resilient healthcare system to effectively mitigate the cancer mortality burden.
文摘IPO underpricing,the tendency for newly issued shares to trade above their offer price on the first day,is a persistent global phenomenon.Empirical evidence suggests that U.S.IPOs averaged an 18.8%first-day return from 1980 to 2001,imposing significant indirect costs on issuers.This paper reviews key explanations for underpricing,including information asymmetry,signaling,agency conflicts,and behavioral factors.Empirical research highlights firm characteristics,underwriter reputation,market conditions,and regulatory factors as major determinants.While underpricing facilitates liquidity and market participation,it also reflects inefficiencies.This study synthesizes theoretical perspectives and empirical findings,emphasizing the need for improved disclosure,governance,and regulatory oversight.
基金supported in part by the National Key Research and Development Program of China(Nos.2020YFA0711200,2022YFB4701301)in part by the Defense Industrial Technology Development Program,China(No.JCKY2021601B016)+1 种基金in part by the Fundamental Research Funds for the Central Universities,China(No.YWF-23-JC-07)in part by the National Natural Science Foundation of China(No.62425302)。
文摘Nighttime navigation faces challenges from limited data and interference,especially when satellite signals are unavailable.Leveraging lunar polarized light,polarization navigation offers a promising solution for nighttime autonomous navigation.Current algorithms,however,are limited by the requirement for known horizontal attitudes,restricting applications.This study introduces an autonomous 3-D attitude determination method to overcome this limitation.Our approach utilizes the Angle of Polarization(AOP)at night to extract neutral points from the AOP pattern.This allows for the calculation of polarization meridian plane information for attitude determination.Subsequently,we present an optimized Polarization TRIAD(Pol-TRIAD)algorithm to acquire the 3-D attitude.The proposed method outperforms the existing approaches in outdoor experiments by achieving lower Root Mean Square Error(RMSE).For one baseline attitude,it improves pitch by 31.7%,roll by 21.7%,and yaw by 2.6%,while for the attitude with a larger tilt angle,the improvements are 64.4%,30.4%,and 9.1%,respectively.
