To enlarge the middle-income group and construct the "olivary" income distribution becomes one of the important issues of the economic development and income distribution reform in China. The income distribu...To enlarge the middle-income group and construct the "olivary" income distribution becomes one of the important issues of the economic development and income distribution reform in China. The income distribution function is estimated with kernel density, and the income distribution M-curve is constructed with CHNS and CHIP data to calculate the middle-income group. Furthermore, a comparative analysis is carried out for the changing trend of the size and proportion of middle-income group. Research conclusion: it is discovered according to the income distribution M-curve that the key to the enlargement of urban middle-income group lies in the lower middle-income group, while the key to the enlargement of rural middle-income group lies in the improvement of the upper middle-income group. The range of middle-income group is expanding, but due to the small scale, low proportion, and poor stability, it has not developed the "olivary" income distribution structure yet, and income inequality tends to be deepened.展开更多
Purpose:This study explores the role of education in fostering middle-income earners in China,elucidating the development and current status of the capabilities of education in this regard.This study uses the historic...Purpose:This study explores the role of education in fostering middle-income earners in China,elucidating the development and current status of the capabilities of education in this regard.This study uses the historical changes in this demographic in the United States as a frame of reference to explore future goal-setting and implementation pathways for expanding the middle-income group through education in China.Design/Approach/Methods:This study uses data on variables such as income,educational attainment,and years since graduation from the China Family Panel Studies database to analyze the changing patterns in China's middle-income group regarding educational attainment.This study also uses data from the Panel Study of Income Dynamics to examine the historical changes in the middle-income group in the United States and compares the findings to those inChina.Findings:Results reveal the following:the changing patterns in the share of the middleincome group relative to educational attainment;the distribution of the low-,middle-,and high-income groups by educational attainment;the changing trends in the share of middleincome group by educational attainment between 2012 and 2018;and the changing trends in the share of middle-and high-income groups by educational attainment regarding the numberofyears sincegraduation.Originality/Value:Rooted in and driven by current issues facing China,this study compares education in China and the United States and offers preliminary evidence of the role of education in expanding the middle-income group.展开更多
Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materi...Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.展开更多
Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divide...Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divides the order of a group G.In this paper,some characterizations of G being p-solvable or p-supersolvable were obtained by analyzing the normal index of certain subgroups of G.These results can be viewed as local version of recent results in the literature.展开更多
The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impac...The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs.展开更多
Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic...Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.展开更多
THE Torch Festival is the most significant and grandest celebration for all Yi communities across China’s Yunnan,Guizhou,and Sichuan provinces,with a history spanning over a thousand years.It reflects the Yi people’...THE Torch Festival is the most significant and grandest celebration for all Yi communities across China’s Yunnan,Guizhou,and Sichuan provinces,with a history spanning over a thousand years.It reflects the Yi people’s long-standing reverence for fire.Originating from the Yi ancestors’worship of fire,the festival was intended to drive away pests and evil spirits,protect crops,and represent prayers for a bountiful harvest.展开更多
The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a su...The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a subduction setting,the distinct investigation reveals the necessity for reassessment.To address this,the authors employ integrated methods encompassing petrological,zircon U-Pb geochronological,Lu-Hf isotopic and geochemical methods for sedimentary rocks from the upper Shenshan subgroup and Banxi Group.The geochemical results indicate that they were formed through the recycling deposition of intermediate-acidic igneous source material and experienced moderate chemical weathering.Additionally,both sedimentary sequences exhibit characteristics consistent with those formed in an intracontinental extensional rift setting since ca.810 Ma.The provenance analysis indicates that the upper Shenshan subgroup primarily originates from the Yangtze Domain,while the Banxi Group from both the Yangtze and Cathaysia domains.Synthesizing with previous studies,the Shenshan Group should be subdivided into the lower and upper subgroups which represent distinct tectonic backgrounds.The lower subgroup is inferred to have formed in an Early Neoproterozoic fore-arc setting,akin to the Zhoutan group.The upper subgroup corresponds to the Banxi Group,representing the Middle Neoproterozoic postorogenic rift setting,responding to the breakup of Rodinia.展开更多
Little is known about the role of active school travel(AST)on mental health among adolescents.Thus,this study aimed to explore the AST-depression association among adolescents aged 12–15 years from 26 low-and middle-...Little is known about the role of active school travel(AST)on mental health among adolescents.Thus,this study aimed to explore the AST-depression association among adolescents aged 12–15 years from 26 low-and middle-income countries(LMICs).Data from the Global School-based Student Health Survey were analyzed in 51,702 adolescents[mean(SD)age 13.8(1.0)years;49.3%boys).Both depressive symptoms and AST were assessed by a single question self-reported measure,respectively.Participants who reported having 5 days or above were considered as AST.Multivariable logistic regression analysis(accounting for sampling weights)was performed while controlling for gender,age,physical activity,sedentary behavior,and food insecurity,and a countrywide meta-analysis was undertaken.The prevalence of depressive symptoms and AST were 30.1%and 37.0%,respectively.Compared with those not having AST,adolescents with AST were less likely to have self-reported depressive symptoms(OR=0.88,95%CI:0.85-0.93)regardless of gender.Countrywide meta-analysis demonstrated that having AST versus not having AST was associated with 12%lower odds for depressive symptoms(OR=0.88;95%CI:0.82-0.94)but with a moderate between-country heterogeneity(I^(2)=59.0%).Based on large samples of adolescents from LMICs,it would be expected that AST may play a critical role in preventing adolescent depression worldwide.However,it is necessary to consider more country-specific factors when implementing AST-related mental health interventions.Future studies should adopt the solid study design to confirm or negate our researchfindings.展开更多
The WHO declared the coronavirus disease 2019(COVID-19)outbreak as a public health emergency of international concern on January 30,2020,and then a pandemic on March 11,2020.COVID-19 affected over 200 countries and te...The WHO declared the coronavirus disease 2019(COVID-19)outbreak as a public health emergency of international concern on January 30,2020,and then a pandemic on March 11,2020.COVID-19 affected over 200 countries and territories worldwide,with 25,541,380 confirmed cases and 852,000 deaths associated with COVID-19 globally,as of September 1,2020.1 While facing such a public health emergency,hospitals were on the front line to deliver health care and psychological services.The early detection,diagnosis,reporting,isolation,and clinical management of patients during a public health emergency required the extensive involvement of hospitals in all aspects.The response capacity of hospitals directly determined the outcomes of the prevention and control of an outbreak.The COVID-19 pandemic has affected almost all nations and territories regardless of their development level or geographic location,although suitable risk mitigation measures differ between developing and developed countries.In low-and middle-income countries(LMICs),the consequences of the pandemic could be more complicated because incidence and mortality might be associated more with a fragile health care system and shortage of related resources.2-3 As evidenced by the situation in Bangladesh,India,Kenya,South Africa,and other LMICs,socioeconomic status(SES)disparity was a major factor in the spread of disease,potentially leading to alarmingly insufficient preparedness and responses in dealing with the COVID-19 pandemic.4 Conversely,the pandemic might also bring more unpredictable socioeconomic and long-term impacts in LMICs,and those with lower SES fare worse in these situations.This review aimed to summarize the responsibilities of and measures taken by hospitals in combatting the COVID-19 outbreak.Our findings are hoped to provide experiences,as well as lessons and potential implications for LMICs.展开更多
In recent decades, the ecological environment has been increasingly challenged by the development of global industrialization and urbanization all over the world, even as global attention for health has raised dramati...In recent decades, the ecological environment has been increasingly challenged by the development of global industrialization and urbanization all over the world, even as global attention for health has raised dramatically. Common global environmental issues, such as air pollution and noise pollution, are associated with lasting impacts on health and contribute significantly to the overall burden of disease. Moreover, a global disparity exists between the burden of such environmental health issues and the global resources available to address this issue. To alleviate the environmental health impacts and ensure a sustainable future for human beings, China has made an important contribution to improving access to ecological protection, environmental governance, patriotic health campaigns, smart city construction, and so on. Experiences gained in China may be useful for some other countries, particularly the low- and middle-income countries with limited sources.展开更多
This paper draws attention to the prospects of sea-based economy to promote Bangladesh in a middle-income country through the sustainable use of marine resources. About three-fourths of the earth is covered by the sea...This paper draws attention to the prospects of sea-based economy to promote Bangladesh in a middle-income country through the sustainable use of marine resources. About three-fourths of the earth is covered by the seas. It plays the vital role in two important functions from ancient time known as the means of communication and the source of huge living and non-living natural resources. At present, the countries are becoming very much concerned about their marine resources to resolve many of the present and future challenges of their economies. Generally for Bangladesh, ocean is contributing a significant role to its overall socio-economic progress through rising up the economic activities across the country and especially to the coastal zone at southern part. This paper investigates how much Bangladesh is capable to take of or handle the challenges to become a middle income country through the Sustainable Development Goals (SDGs). In addition, it has attempted with a closer-look to find out the barriers or limitations of these activities from different angles if exist.展开更多
Low-and middle-income countries(LMICs)bear the greater share of the global mental health burden but are ill-equipped to deal with it because of severe resource constraints leading to a large treatment gap.The remote p...Low-and middle-income countries(LMICs)bear the greater share of the global mental health burden but are ill-equipped to deal with it because of severe resource constraints leading to a large treatment gap.The remote provision of mental health services by digital means can effectively augment conventional services in LMICs to reduce the treatment gap.Digital psychiatry in LMICs has always lagged behind high-income countries,but there have been encouraging developments in the last decade.There is increasing research on the efficacy of digital psychiatric interventions.However,the evidence is not adequate to conclude that digital psychiatric interventions are invariably effective in LMICs.A striking development has been the rise in mobile and smartphone ownership in LMICs,which has driven the increasing use of mobile technologies to deliver mental health services.An innovative use of mobile technologies has been to optimize task-shifting,which involves delivering mental healthcare services in community settings using non-specialist health professionals.Emerging evidence from LMICs shows that it is possible to use digital tools to train non-specialist workers effectively and ensure that the psychosocial interventions they deliver are efficacious.Despite these promising developments,many barriers such as service costs,underdeveloped infrastructure,lack of trained professionals,and significant disparities in access to digital services impede the progress of digital psychiatry in LMICs.To overcome these barriers,digital psychiatric services in LMICs should address contextual factors influencing the delivery of digital services,ensure collaboration between different stakeholders,and focus on reducing the digital divide.展开更多
Purpose:Little is known about the role of food insecurity(FIS)on depressive symptoms among adolescents.Thus,this study aimed to explore the association between FIS and depressive symptoms among adolescents aged 12–15...Purpose:Little is known about the role of food insecurity(FIS)on depressive symptoms among adolescents.Thus,this study aimed to explore the association between FIS and depressive symptoms among adolescents aged 12–15 years from low-and middle-income countries across the world.Methods:Data from the Global school-based Student Health Survey were analyzed in 51,702 adolescents[mean(SD)age 13.8(1.0)years;49.3% girls].Self-reported measures assessed depressive symptoms during the past 12 months,and food insecurity.Partici-pants reporting yes for depressive symptoms.FIS was categorized intofive levels,including‘never’,‘rarely’,‘some-times’,‘most of the time’and‘always’.Multivariable logistic regression analysis was performed,and a country-wise meta-analysis was undertaken to compare country difference in the associations between FIS and depressive symptoms.Results:The prevalence of depressive symptoms was 30.0%,respectively.Compared with those reporting never for FIS,adolescents with increased severity of FIS were more likely to report depressive symptoms regardless of gender.Country-wise meta-analysis demonstrated that having FIS versus not having FIS was asso-ciated with 60%greater odds for depressive symptoms(OR=1.60;95%CI:1.52–1.69)but with a moderate between-country heterogeneity(I^(2)=12.7%).Conclusion:The current study indicates that alleviating FIS may be an effective prevention against depressive symptoms among adolescents from LMICs.Future studies should adopt improved study design to confirm or negate our researchfindings,which informs more efficient public mental health interventions.展开更多
Background:Adolescents are highly vulnerable to depressive symptoms worldwide partially because of limited social supports.However,it still remains largely unknown regarding the associations between social support(s)a...Background:Adolescents are highly vulnerable to depressive symptoms worldwide partially because of limited social supports.However,it still remains largely unknown regarding the associations between social support(s)and depressive symptoms among adolescents living in low-and middle-income countries(LMICs).The aim of this study aimed to explore the associations between different types of social support and depressive symptoms in adolescents from LMICs.Methods:Data were retrieved from the Global School-based Health Survey(GSHS)in which 92,551 adolescents(50.6%females)were included with mean of 15.6 years.Depressive symptoms in the past one month as the dependent variable were measured in combination with social support(was measured by“During the past 30 days,how often were most of the students in your school kind and helpful?”).Multivariable logistic regression and meta-analysis of country-wise estimates were performed to investigate the associations between social support and depressive symptoms,and the heterogeneity of the associations across the countries,respectively.Results:The prevalence of depressive symptoms was 30.9%of adolescents from LMICs.Peer support and parental connectedness were two major factors that were significantly associated with depression symptoms in adolescents.However,the associations of peer support and parental connectedness with depressive symptoms were significant in males and females,respectively.The country-wise analysis indicated that varied inconsistency(small to large)across the associations of peer support and parental connectedness with depressive symptoms in adolescents.Conclusion:Results in this study provides multi-national evidence of the protective roles of social support against depressive symptoms among adolescents.However,the association between social support and depression symptoms may be moderated by sex and types of social support.Although we found that social sup-port may be an important protective factor against depressive symptoms in adolescents from LMICs,specifically designed interventions should be implemented based on sex difference and country difference.展开更多
Surgical management of diseases is recognised as a major unmet need in low and middle-income countries(LMICs). Laparoscopic surgery has been present since the 1980 s and offers the benefit of minimising the morbidity ...Surgical management of diseases is recognised as a major unmet need in low and middle-income countries(LMICs). Laparoscopic surgery has been present since the 1980 s and offers the benefit of minimising the morbidity and potential mortality associated with laparotomies. Laparotomies are often carried out in LMICs for diagnosis and management, due to lack of radiological investigative and intervention options. The use of laparoscopy for diagnosis and treatment is globally variable, with highincome countries using laparoscopy routinely compared with LMICs. The specific advantages of minimally invasive surgery such as lower surgical site infections and earlier return to work are of great benefit for patients in LMICs, as time lost not working could result in a family not being able to sustain themselves. Laparoscopic surgery and training is not cheap. Cost is a major barrier to healthcare access for a significant population in LMICs. Therefore, cost is usually seen as a major barrier for laparoscopic surgery to be integrated into routine practice in LMICs. The aim of this review is to focus on the practice, training and safety of laparoscopic surgery in LMICs. In addition it highlights the barriers to progress in adopting laparoscopic surgery in LMICs and how to address them.展开更多
Community health workers(CHWs)represent the backbone of primary health systems,especially in many low-and middle-income countries(LMICs).The coronavirus disease 2019(COVID-19)pandemic stretched health sys-tems and inc...Community health workers(CHWs)represent the backbone of primary health systems,especially in many low-and middle-income countries(LMICs).The coronavirus disease 2019(COVID-19)pandemic stretched health sys-tems and increased the workload for CHWs.The objective of this scoping review was to identify the mental health symptoms experienced among CHWs in LMICs during the COVID-19 pandemic.We searched PubMed for published literature,from January 1,2020 to December 31,2022 that focused on documenting the experiences of burnout,distress,and mental health symptoms among CHWs in LMICs.The quality of included studies was assessed using the Joanna Briggs Institute Critical Appraisal Tool.Included studies were grouped into the follow-ing broad thematic categories:(1)symptoms experienced;(2)drivers of different mental health symptoms;and(3)strategies for coping with different symptoms.We identified 10 cross-sectional,qualitative,and observational studies from 11 LMICs in South and Southeast Asia,South America,and Eastern/Southern Africa that assessed the mental health burden CHWs faced during the pandemic.The studies identified disorders and symptoms such as depression,anxiety,fear,burnout,worsened stress,and fatigue.Contributing factors included increased work-load,financial constraints,and an understaffed and underequipped workplace.CHWs reported using different adaptive responses like humor,support from family and colleagues,denial,and substance use,and asked for recommended regular mental health checkups and counseling.More research and policies should be targeted to-wards promoting the mental wellbeing of CHWs to help ensure responsive and resilient health systems in LMICs in the face of future emerging public health threats.展开更多
<strong>Background: </strong>Low and Middle-Income Countries (LMIC) account for 94% of maternal deaths annually. Interventions to reduce these deaths include;access to Emergency Obstetric Care (EmOC) and S...<strong>Background: </strong>Low and Middle-Income Countries (LMIC) account for 94% of maternal deaths annually. Interventions to reduce these deaths include;access to Emergency Obstetric Care (EmOC) and Skilled Birth Attendant (SBA) at childbirth. However, evidence indicates increasing access to EmOC, and SBA only does not translate into positive maternal and newborn outcome due to disrespectful care faced by women during labour. World Health Organization (WHO) guidelines emphasize on positive birth experience through Respectful Maternity Care (RMC). Therefore, this review aims to explore enablers and barriers to respectful maternity care in low and middle-income countries. <strong>Methods:</strong> We conducted an exhaustive literature search for studies that reported on enablers and barriers to respectful maternity care. Qualitative studies done in low and middle-income countries, published in English Language from the year 2000 to June 2020 were included in this study. Articles were screened by two researchers for eligibility and critical appraisal skills programme checklist was used to appraise the quality. The themes and quotes from the studies were extracted and synthesized using thematic synthesis. <strong>Results: </strong>The search strategy generated 14,190 articles and 54 studies met the inclusion criteria. Two main themes: interpersonal relationship and support, and privacy and confidential care were reported as both enablers and barriers to respectful maternity care. Strategies to promote RMC were: health education to pregnant women on care expected during labour, good communication between maternity staff and women, capacity building of staff on RMC and staff motivation. <strong>Conclusion:</strong> Respectful maternity care plays a big role in promoting health-seeking behaviours among pregnant women. However, women experience barriers ranging from provider behaviour, work environment and health system challenges. Ensuring a dignified and respectful working environment could contribute to an increase in health seeking-behaviours and consequently reduction of maternal mortality.展开更多
文摘To enlarge the middle-income group and construct the "olivary" income distribution becomes one of the important issues of the economic development and income distribution reform in China. The income distribution function is estimated with kernel density, and the income distribution M-curve is constructed with CHNS and CHIP data to calculate the middle-income group. Furthermore, a comparative analysis is carried out for the changing trend of the size and proportion of middle-income group. Research conclusion: it is discovered according to the income distribution M-curve that the key to the enlargement of urban middle-income group lies in the lower middle-income group, while the key to the enlargement of rural middle-income group lies in the improvement of the upper middle-income group. The range of middle-income group is expanding, but due to the small scale, low proportion, and poor stability, it has not developed the "olivary" income distribution structure yet, and income inequality tends to be deepened.
基金funded by the National Social Science Fund of China(Grant CGA190249)。
文摘Purpose:This study explores the role of education in fostering middle-income earners in China,elucidating the development and current status of the capabilities of education in this regard.This study uses the historical changes in this demographic in the United States as a frame of reference to explore future goal-setting and implementation pathways for expanding the middle-income group through education in China.Design/Approach/Methods:This study uses data on variables such as income,educational attainment,and years since graduation from the China Family Panel Studies database to analyze the changing patterns in China's middle-income group regarding educational attainment.This study also uses data from the Panel Study of Income Dynamics to examine the historical changes in the middle-income group in the United States and compares the findings to those inChina.Findings:Results reveal the following:the changing patterns in the share of the middleincome group relative to educational attainment;the distribution of the low-,middle-,and high-income groups by educational attainment;the changing trends in the share of middleincome group by educational attainment between 2012 and 2018;and the changing trends in the share of middle-and high-income groups by educational attainment regarding the numberofyears sincegraduation.Originality/Value:Rooted in and driven by current issues facing China,this study compares education in China and the United States and offers preliminary evidence of the role of education in expanding the middle-income group.
文摘Platinum group metals have high melting points,strong corrosion resistance,stable chemical properties,and low oxygen permeability in high-temperature oxygen-containing environments.As thermal protective coating materials,they have gained essential applications in the aerospace field and have excellent prospects for application in frontier military fields,such as protecting hot-end components of hypersonic aircraft.This research reviewed the latest research progress of platinum group metal coatings with hightemperature oxidation resistance,including coating preparation techniques,oxidation failure,and alloying modification.The leading preparation techniques of current platinum group metal coatings were discussed,as well as the advantages and disadvantages of various existing preparation techniques.Besides,the intrinsic properties,failure forms,and failure mechanisms of coatings of single platinum group metal in high-temperature oxygen-containing environments were analyzed.On this basis,the necessity,main methods,and main achievements of alloying modification of platinum group metals were summarized.Finally,the future development of platinum group coatings with high-temperature oxidation resistance was discussed and prospected.
基金Supported by the National Natural Science Foundation of China(Grant No.12071092)Guangdong Basic and Applied Basic Research Foundation(Grant No.2025A1515012072)+1 种基金the Natural Science Research Project of Anhui Educational Committee(Grant No.2024AH051298)the Scientific Research Foundation of Bozhou University(Grant No.BYKQ202419).
文摘Let G be a finite group and H a subgroup of G.The normal index of H in G is defined as the order of K/H_(G),where K is a normal supplement of H in G such that|K|is minimal and H_(G)≤K■G.Let p be a prime which divides the order of a group G.In this paper,some characterizations of G being p-solvable or p-supersolvable were obtained by analyzing the normal index of certain subgroups of G.These results can be viewed as local version of recent results in the literature.
基金financially supported by the National Natural Science Foundation of China (Nos.22375024,21975031,51933001,and 21734009)。
文摘The fluorination strategy has been proven effective in significantly enhancing the photovoltaic performance of organic solar cells(OSCs) based on non-fused ring electron acceptors(NFREAs).However,research on the impact of fluorination positions at side chains on NFREAs device performance remains scant.In this study,we introduce two isomeric NFREAs,designated as GA-2F-E and GA-2F,distinguished by their fluorination positions at the side chains.Both NFREAs share a thiophene[3,2-b]thiophene core,but their side chains differ:GA-2F-E features two(4-butylphenyl)-N-(4-fluorophenyl) amino groups,whereas GA-2F's side chains consist of bis(4-fluorophenyl)amino and bis(4-butylphenyl)amino groups attached to opposite sides of the core.To delve into the influence of fluorination positions on the optoelectronic properties,aggregation behavior,and overall efficiency of the acceptor molecules,a comprehensive investigation was conducted.The findings reveal that,despite similar photophysical properties and comparable absorption bandwidths,GA-2F-E,with fluorine atoms positioned on both sides of the molecular framework,demonstrates more compact π-π stacking,reduced bimolecular recombination,superior exciton transport,and a more balanced,higher mobility.As a result of these advantages,OSCs optimized with D18:GA-2F-E achieve a remarkable power conversion efficiency(PCE) of 16.45 %,surpassing the 15.83 %PCE of devices utilizing D18:GA-2F.This research underscores the potential of NFREAs in future applications and highlights the significance of fluorination positions in enhancing OSC performance,paving the way for the development of more efficient NFREAs.
文摘Let M be a compact n-manifold of positive sectional curvature.We will review classical results on the fundamental group of M,a motivation on the c(n)-cyclic conjecture that the fundamental group of M contains a cyclic subgroup of index bounded above by c(n),a constant depending only on n,and we will survey partial results(up to date)on the c(n)-cyclic conjecture.
文摘THE Torch Festival is the most significant and grandest celebration for all Yi communities across China’s Yunnan,Guizhou,and Sichuan provinces,with a history spanning over a thousand years.It reflects the Yi people’s long-standing reverence for fire.Originating from the Yi ancestors’worship of fire,the festival was intended to drive away pests and evil spirits,protect crops,and represent prayers for a bountiful harvest.
基金supported by the National Natural Science Foundation of China(42372250,42102262 and 41972235)National Key Research and Development Program Project(2023YFF0803701)+1 种基金Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)(SML2023SP206)the program of China Scholarship Council。
文摘The Shenshan Group provides important geological information which is vital in unraveling the amalgamation and subsequent rifting processes of South China.While conventional studies have asserted its formation in a subduction setting,the distinct investigation reveals the necessity for reassessment.To address this,the authors employ integrated methods encompassing petrological,zircon U-Pb geochronological,Lu-Hf isotopic and geochemical methods for sedimentary rocks from the upper Shenshan subgroup and Banxi Group.The geochemical results indicate that they were formed through the recycling deposition of intermediate-acidic igneous source material and experienced moderate chemical weathering.Additionally,both sedimentary sequences exhibit characteristics consistent with those formed in an intracontinental extensional rift setting since ca.810 Ma.The provenance analysis indicates that the upper Shenshan subgroup primarily originates from the Yangtze Domain,while the Banxi Group from both the Yangtze and Cathaysia domains.Synthesizing with previous studies,the Shenshan Group should be subdivided into the lower and upper subgroups which represent distinct tectonic backgrounds.The lower subgroup is inferred to have formed in an Early Neoproterozoic fore-arc setting,akin to the Zhoutan group.The upper subgroup corresponds to the Banxi Group,representing the Middle Neoproterozoic postorogenic rift setting,responding to the breakup of Rodinia.
基金supported by the National Social Science Foundation(18BTY011)Brendon Stubbs is supported by a Clinical Lectureship(ICA-CL-2017-03-001)jointly funded by Health Education England(HEE)and the National Institute for Health Research(NIHR)+1 种基金Brendon Stubbs is part funded by the NIHR Biomedical Research Centre at South London and Maudsley NHS Foundation Trust.Brendon Stubbs also holds active grants with the Medical Research Council(GCRF and multimorbidity calls)and Guys and St Thomas Charity(GSTT).Brendon Stubbs has received consultancy fees from ASICS Europe BV.The views expressed are those of the author(s)and not necessarily those of the(partner organization),the NHS,the NIHR,the Department of Health and Social Care,the MRC or GSTTZD’s contribution was supported by the Hungarian National Research,Development and Innovation Office(KKP126835,ELTE Thematic Excellence Programme 2020,KP2020-IKA-05).
文摘Little is known about the role of active school travel(AST)on mental health among adolescents.Thus,this study aimed to explore the AST-depression association among adolescents aged 12–15 years from 26 low-and middle-income countries(LMICs).Data from the Global School-based Student Health Survey were analyzed in 51,702 adolescents[mean(SD)age 13.8(1.0)years;49.3%boys).Both depressive symptoms and AST were assessed by a single question self-reported measure,respectively.Participants who reported having 5 days or above were considered as AST.Multivariable logistic regression analysis(accounting for sampling weights)was performed while controlling for gender,age,physical activity,sedentary behavior,and food insecurity,and a countrywide meta-analysis was undertaken.The prevalence of depressive symptoms and AST were 30.1%and 37.0%,respectively.Compared with those not having AST,adolescents with AST were less likely to have self-reported depressive symptoms(OR=0.88,95%CI:0.85-0.93)regardless of gender.Countrywide meta-analysis demonstrated that having AST versus not having AST was associated with 12%lower odds for depressive symptoms(OR=0.88;95%CI:0.82-0.94)but with a moderate between-country heterogeneity(I^(2)=59.0%).Based on large samples of adolescents from LMICs,it would be expected that AST may play a critical role in preventing adolescent depression worldwide.However,it is necessary to consider more country-specific factors when implementing AST-related mental health interventions.Future studies should adopt the solid study design to confirm or negate our researchfindings.
基金supported by the National Natural Science Foundation of China(No.72042014).
文摘The WHO declared the coronavirus disease 2019(COVID-19)outbreak as a public health emergency of international concern on January 30,2020,and then a pandemic on March 11,2020.COVID-19 affected over 200 countries and territories worldwide,with 25,541,380 confirmed cases and 852,000 deaths associated with COVID-19 globally,as of September 1,2020.1 While facing such a public health emergency,hospitals were on the front line to deliver health care and psychological services.The early detection,diagnosis,reporting,isolation,and clinical management of patients during a public health emergency required the extensive involvement of hospitals in all aspects.The response capacity of hospitals directly determined the outcomes of the prevention and control of an outbreak.The COVID-19 pandemic has affected almost all nations and territories regardless of their development level or geographic location,although suitable risk mitigation measures differ between developing and developed countries.In low-and middle-income countries(LMICs),the consequences of the pandemic could be more complicated because incidence and mortality might be associated more with a fragile health care system and shortage of related resources.2-3 As evidenced by the situation in Bangladesh,India,Kenya,South Africa,and other LMICs,socioeconomic status(SES)disparity was a major factor in the spread of disease,potentially leading to alarmingly insufficient preparedness and responses in dealing with the COVID-19 pandemic.4 Conversely,the pandemic might also bring more unpredictable socioeconomic and long-term impacts in LMICs,and those with lower SES fare worse in these situations.This review aimed to summarize the responsibilities of and measures taken by hospitals in combatting the COVID-19 outbreak.Our findings are hoped to provide experiences,as well as lessons and potential implications for LMICs.
基金This work was supported by the National Key Research and Development Program of China(No.2016YFC0206500)the National Research Program for Key Issues in Air Pollution Control of China(No.DQGG0401).
文摘In recent decades, the ecological environment has been increasingly challenged by the development of global industrialization and urbanization all over the world, even as global attention for health has raised dramatically. Common global environmental issues, such as air pollution and noise pollution, are associated with lasting impacts on health and contribute significantly to the overall burden of disease. Moreover, a global disparity exists between the burden of such environmental health issues and the global resources available to address this issue. To alleviate the environmental health impacts and ensure a sustainable future for human beings, China has made an important contribution to improving access to ecological protection, environmental governance, patriotic health campaigns, smart city construction, and so on. Experiences gained in China may be useful for some other countries, particularly the low- and middle-income countries with limited sources.
文摘This paper draws attention to the prospects of sea-based economy to promote Bangladesh in a middle-income country through the sustainable use of marine resources. About three-fourths of the earth is covered by the seas. It plays the vital role in two important functions from ancient time known as the means of communication and the source of huge living and non-living natural resources. At present, the countries are becoming very much concerned about their marine resources to resolve many of the present and future challenges of their economies. Generally for Bangladesh, ocean is contributing a significant role to its overall socio-economic progress through rising up the economic activities across the country and especially to the coastal zone at southern part. This paper investigates how much Bangladesh is capable to take of or handle the challenges to become a middle income country through the Sustainable Development Goals (SDGs). In addition, it has attempted with a closer-look to find out the barriers or limitations of these activities from different angles if exist.
文摘Low-and middle-income countries(LMICs)bear the greater share of the global mental health burden but are ill-equipped to deal with it because of severe resource constraints leading to a large treatment gap.The remote provision of mental health services by digital means can effectively augment conventional services in LMICs to reduce the treatment gap.Digital psychiatry in LMICs has always lagged behind high-income countries,but there have been encouraging developments in the last decade.There is increasing research on the efficacy of digital psychiatric interventions.However,the evidence is not adequate to conclude that digital psychiatric interventions are invariably effective in LMICs.A striking development has been the rise in mobile and smartphone ownership in LMICs,which has driven the increasing use of mobile technologies to deliver mental health services.An innovative use of mobile technologies has been to optimize task-shifting,which involves delivering mental healthcare services in community settings using non-specialist health professionals.Emerging evidence from LMICs shows that it is possible to use digital tools to train non-specialist workers effectively and ensure that the psychosocial interventions they deliver are efficacious.Despite these promising developments,many barriers such as service costs,underdeveloped infrastructure,lack of trained professionals,and significant disparities in access to digital services impede the progress of digital psychiatry in LMICs.To overcome these barriers,digital psychiatric services in LMICs should address contextual factors influencing the delivery of digital services,ensure collaboration between different stakeholders,and focus on reducing the digital divide.
文摘Purpose:Little is known about the role of food insecurity(FIS)on depressive symptoms among adolescents.Thus,this study aimed to explore the association between FIS and depressive symptoms among adolescents aged 12–15 years from low-and middle-income countries across the world.Methods:Data from the Global school-based Student Health Survey were analyzed in 51,702 adolescents[mean(SD)age 13.8(1.0)years;49.3% girls].Self-reported measures assessed depressive symptoms during the past 12 months,and food insecurity.Partici-pants reporting yes for depressive symptoms.FIS was categorized intofive levels,including‘never’,‘rarely’,‘some-times’,‘most of the time’and‘always’.Multivariable logistic regression analysis was performed,and a country-wise meta-analysis was undertaken to compare country difference in the associations between FIS and depressive symptoms.Results:The prevalence of depressive symptoms was 30.0%,respectively.Compared with those reporting never for FIS,adolescents with increased severity of FIS were more likely to report depressive symptoms regardless of gender.Country-wise meta-analysis demonstrated that having FIS versus not having FIS was asso-ciated with 60%greater odds for depressive symptoms(OR=1.60;95%CI:1.52–1.69)but with a moderate between-country heterogeneity(I^(2)=12.7%).Conclusion:The current study indicates that alleviating FIS may be an effective prevention against depressive symptoms among adolescents from LMICs.Future studies should adopt improved study design to confirm or negate our researchfindings,which informs more efficient public mental health interventions.
基金supported by National Natural Science Foundation of China(31871115).
文摘Background:Adolescents are highly vulnerable to depressive symptoms worldwide partially because of limited social supports.However,it still remains largely unknown regarding the associations between social support(s)and depressive symptoms among adolescents living in low-and middle-income countries(LMICs).The aim of this study aimed to explore the associations between different types of social support and depressive symptoms in adolescents from LMICs.Methods:Data were retrieved from the Global School-based Health Survey(GSHS)in which 92,551 adolescents(50.6%females)were included with mean of 15.6 years.Depressive symptoms in the past one month as the dependent variable were measured in combination with social support(was measured by“During the past 30 days,how often were most of the students in your school kind and helpful?”).Multivariable logistic regression and meta-analysis of country-wise estimates were performed to investigate the associations between social support and depressive symptoms,and the heterogeneity of the associations across the countries,respectively.Results:The prevalence of depressive symptoms was 30.9%of adolescents from LMICs.Peer support and parental connectedness were two major factors that were significantly associated with depression symptoms in adolescents.However,the associations of peer support and parental connectedness with depressive symptoms were significant in males and females,respectively.The country-wise analysis indicated that varied inconsistency(small to large)across the associations of peer support and parental connectedness with depressive symptoms in adolescents.Conclusion:Results in this study provides multi-national evidence of the protective roles of social support against depressive symptoms among adolescents.However,the association between social support and depression symptoms may be moderated by sex and types of social support.Although we found that social sup-port may be an important protective factor against depressive symptoms in adolescents from LMICs,specifically designed interventions should be implemented based on sex difference and country difference.
文摘Surgical management of diseases is recognised as a major unmet need in low and middle-income countries(LMICs). Laparoscopic surgery has been present since the 1980 s and offers the benefit of minimising the morbidity and potential mortality associated with laparotomies. Laparotomies are often carried out in LMICs for diagnosis and management, due to lack of radiological investigative and intervention options. The use of laparoscopy for diagnosis and treatment is globally variable, with highincome countries using laparoscopy routinely compared with LMICs. The specific advantages of minimally invasive surgery such as lower surgical site infections and earlier return to work are of great benefit for patients in LMICs, as time lost not working could result in a family not being able to sustain themselves. Laparoscopic surgery and training is not cheap. Cost is a major barrier to healthcare access for a significant population in LMICs. Therefore, cost is usually seen as a major barrier for laparoscopic surgery to be integrated into routine practice in LMICs. The aim of this review is to focus on the practice, training and safety of laparoscopic surgery in LMICs. In addition it highlights the barriers to progress in adopting laparoscopic surgery in LMICs and how to address them.
基金supported by grants from the National Institute of Mental Health(U19MH113211-01)and the Harvard Global Health Institute Burke Fellowship.
文摘Community health workers(CHWs)represent the backbone of primary health systems,especially in many low-and middle-income countries(LMICs).The coronavirus disease 2019(COVID-19)pandemic stretched health sys-tems and increased the workload for CHWs.The objective of this scoping review was to identify the mental health symptoms experienced among CHWs in LMICs during the COVID-19 pandemic.We searched PubMed for published literature,from January 1,2020 to December 31,2022 that focused on documenting the experiences of burnout,distress,and mental health symptoms among CHWs in LMICs.The quality of included studies was assessed using the Joanna Briggs Institute Critical Appraisal Tool.Included studies were grouped into the follow-ing broad thematic categories:(1)symptoms experienced;(2)drivers of different mental health symptoms;and(3)strategies for coping with different symptoms.We identified 10 cross-sectional,qualitative,and observational studies from 11 LMICs in South and Southeast Asia,South America,and Eastern/Southern Africa that assessed the mental health burden CHWs faced during the pandemic.The studies identified disorders and symptoms such as depression,anxiety,fear,burnout,worsened stress,and fatigue.Contributing factors included increased work-load,financial constraints,and an understaffed and underequipped workplace.CHWs reported using different adaptive responses like humor,support from family and colleagues,denial,and substance use,and asked for recommended regular mental health checkups and counseling.More research and policies should be targeted to-wards promoting the mental wellbeing of CHWs to help ensure responsive and resilient health systems in LMICs in the face of future emerging public health threats.
文摘<strong>Background: </strong>Low and Middle-Income Countries (LMIC) account for 94% of maternal deaths annually. Interventions to reduce these deaths include;access to Emergency Obstetric Care (EmOC) and Skilled Birth Attendant (SBA) at childbirth. However, evidence indicates increasing access to EmOC, and SBA only does not translate into positive maternal and newborn outcome due to disrespectful care faced by women during labour. World Health Organization (WHO) guidelines emphasize on positive birth experience through Respectful Maternity Care (RMC). Therefore, this review aims to explore enablers and barriers to respectful maternity care in low and middle-income countries. <strong>Methods:</strong> We conducted an exhaustive literature search for studies that reported on enablers and barriers to respectful maternity care. Qualitative studies done in low and middle-income countries, published in English Language from the year 2000 to June 2020 were included in this study. Articles were screened by two researchers for eligibility and critical appraisal skills programme checklist was used to appraise the quality. The themes and quotes from the studies were extracted and synthesized using thematic synthesis. <strong>Results: </strong>The search strategy generated 14,190 articles and 54 studies met the inclusion criteria. Two main themes: interpersonal relationship and support, and privacy and confidential care were reported as both enablers and barriers to respectful maternity care. Strategies to promote RMC were: health education to pregnant women on care expected during labour, good communication between maternity staff and women, capacity building of staff on RMC and staff motivation. <strong>Conclusion:</strong> Respectful maternity care plays a big role in promoting health-seeking behaviours among pregnant women. However, women experience barriers ranging from provider behaviour, work environment and health system challenges. Ensuring a dignified and respectful working environment could contribute to an increase in health seeking-behaviours and consequently reduction of maternal mortality.
