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Reevaluating health metrics:Unraveling the limitations of disabilityadjusted life years as an indicator in disease burden assessment
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作者 Ariel Beresniak Dominique Bremond-Gignac +1 位作者 Danielle Dupont Gerard Duru 《World Journal of Methodology》 2025年第1期14-19,共6页
In 1993,the World Bank released a global report on the efficacy of health promotion,introducing the disability-adjusted life years(DALY)as a novel indicator.The DALY,a composite metric incorporating temporal and quali... In 1993,the World Bank released a global report on the efficacy of health promotion,introducing the disability-adjusted life years(DALY)as a novel indicator.The DALY,a composite metric incorporating temporal and qualitative data,is grounded in preferences regarding disability status.This review delineates the algorithm used to calculate the value of the proposed DALY synthetic indicator and elucidates key methodological challenges associated with its application.In contrast to the quality-adjusted life years approach,derived from multi-attribute utility theory,the DALY stands as an independent synthetic indicator that adopts the assumptions of the Time Trade Off utility technique to define Disability Weights.Claiming to rely on no mathematical or economic theory,DALY users appear to have exempted themselves from verifying whether this indicator meets the classical properties required of all indicators,notably content validity,reliability,specificity,and sensitivity.The DALY concept emerged primarily to facilitate comparisons of the health impacts of various diseases globally within the framework of the Global Burden of Disease initiative,leading to numerous publications in international literature.Despite widespread adoption,the DALY synthetic indicator has prompted significant methodological concerns since its inception,manifesting in inconsistent and non-reproducible results.Given the substantial diffusion of the DALY indicator and its critical role in health impact assessments,a reassessment is warranted.This reconsideration is imperative for enhancing the robustness and reliability of public health decisionmaking processes. 展开更多
关键词 Disability adjusted life years Cost-utility analyses Outcome research Public health Burden of disease
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Characteristics of the HIV/AIDS Epidemic among People Aged≥50 Years in China during 2018–2021
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作者 HOU Yu Shan JIN Yi Chen +3 位作者 CAI Chang TANG Hou Lin QIN Qian Qian LYU Fan 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2024年第4期399-405,共7页
Objective This study aimed to determine the current epidemiological status of PLWHA aged≥50 years in China from 2018 to 2021.It also aimed to recommend targeted interventions for the prevention and treatment of HIV/A... Objective This study aimed to determine the current epidemiological status of PLWHA aged≥50 years in China from 2018 to 2021.It also aimed to recommend targeted interventions for the prevention and treatment of HIV/AIDS in elderly patients.Methods Data on newly reported cases of PLWHA,aged≥50 years in China from 2018 to 2021,were collected using the CRIMS.Trend tests and spatial analyses were also conducted.Results Between 2018 and 2021,237,724 HIV/AIDS cases were reported among patients aged≥50 years in China.The main transmission route was heterosexual transmission(91.24%).Commercial heterosexual transmission(CHC)was the primary mode of transmission among males,while non-marital non-CHC([NMNCHC];60.59%)was the prevalent route in women.The proportion of patients with CHC decreased over time(Z=67.716,P<0.01),while that of patients with NMNCHC increased(Z=153.05,P<0.01).The sex ratio varied among the different modes of infection,and it peaked at 17.65 for CHC.The spatial analysis indicated spatial clustering,and the high-high clustering areas were mainly distributed in the southwestern and central-southern provinces.Conclusion In China,PLWHA,aged≥50 years,were predominantly infected through heterosexual transmission.The primary modes of infection were CHC and NMNCHC.There were variations in the sex ratio among different age groups,infected through various sexual behaviors.HIV/AIDS cases exhibited spatial clustering.Based on these results,the expansion of HIV testing,treatment,and integrated behavioral interventions in high-risk populations is recommended to enhance disease detection in key regions. 展开更多
关键词 HIV/AIDS Aged≥50 years China
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Effect of a Nutrition Education Intervention on Food Safety Knowledge, Attitudes and Practices of Mothers of Children under 5 Years in the Peri-Urban Areas of Bobo-Dioulasso: Before and after Study
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作者 Alain Hien Jérome W. Somé +4 位作者 Olivier O. Sombié Isidore Traoré Augustin N. Zeba Georges Anicet Ouedraogo Roland Nâg-Tiero Meda 《Food and Nutrition Sciences》 CAS 2024年第5期401-420,共20页
Background: This study assessed the effect of a nutrition education intervention. This intervention aimed to improve the knowledge, attitudes, and practices of mothers on food safety in the peri-urban areas of Bobo-Di... Background: This study assessed the effect of a nutrition education intervention. This intervention aimed to improve the knowledge, attitudes, and practices of mothers on food safety in the peri-urban areas of Bobo-Dioulasso in Burkina Faso. Methods: A total of 243 mothers of children under 5 years in the peri-urban of Bobo-Dioulasso were administered the FAO questionnaire for food safety knowledge, attitudes, and practices assessment during two cross-sectional surveys, before and after the intervention, in January and October 2017. The intervention included two components consisting of a theoretical phase (counselling and discussion) and cooking demonstrations implemented for ten months. To account for the before-and-after design of the study, the McNemar’s test was used to assess the effect of the intervention on food safety KAP of mothers of children under 5 years. Results: The mean age of mothers was 29 ± 6.2 years and 50.6% of them were between 20 and 29 years old. One for knowledge (cooking thoroughly with, p-value = 0.0001) and another for attitudes (perceived benefits of reheating leftovers before eating them, p-value = 0.0001), significantly increased after the intervention. In terms of food safety practices, all the indicators (cleaning of dirty surfaces, plates and utensils and storage of perishable foods) significantly increased (all p = 0.0001 Conclusion: This study provided some evidence of an effective nutrition education intervention for improving maternal KAP on food safety for their child’s feeding. 展开更多
关键词 Nutrition Education Intervention KNOWLEDGE Attitudes and Practices Food Safety Mothers of Children under 5 years Burkina Faso
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Review of Two Years of Surgical Activities of the General Surgery Department of the Reference Health Center of Commune I of Bamako Mali
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作者 Tounkara Cheickna Cisse Amadou Beydi +5 位作者 Samake Hamidou Diarra Issaka Sanogo Modibo Diarra Bogoba Doumbia Seydou Yena Sadio 《Surgical Science》 2024年第4期195-206,共12页
The objectives of this work were to evaluate the surgical activities carried out in the general surgery department of the Reference Health Center of Commune I of Bamako, to describe the sociodemographic characteristic... The objectives of this work were to evaluate the surgical activities carried out in the general surgery department of the Reference Health Center of Commune I of Bamako, to describe the sociodemographic characteristics of the operated patients, to determine the main pathologies encountered and to evaluate qualitatively the result of the treatment. In order to improve performance, and the quality of care, and to identify common pathologies in the surgical department, we undertook a retrospective study on surgical activities from January 2009 to December 2010. At the end of this study, out of 474 men and 187 women (equal sex ratio 2.53);we were able to determine the frequency of surgical pathologies. Farmers, housewives and pupils/students were the most represented with 25.9% respectively;20% and 13.3%. The most frequently observed pathologies were wall hernia (44.8%), prostate adenoma (12%) and acute appendicitis (10.5%). The average length of hospitalization was 3.43 days. Infectious complications affected 25 patients (3.8% of cases) and a death rate of 0.45% (i.e. 3 patients). The average cost of care was 53,500 FCFA. Indeed, the reality of surgical practice in health centers was not the same because of the level of skills of practicing surgeons. 展开更多
关键词 Assessment Surgical Activities 2 years Reference health Center of Commune I BAMAKO
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Factors Associated with Mortality in Children Aged 1 Month to 15 Years Hospitalized in the Pediatric Ward of the Kalaban-Coro Reference Health Center: Cross-Sectional Study
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作者 Abdoul Salam Diarra Mohamed Diarra +13 位作者 Dramane Touré Tawfiq Abu Beyadari Balilé Harber Maimouna Kanté Issa Guindo Belco Maiga Karamoko Sacko Kalirou Traoré Fatoumata Dicko Mamadou Togo Kalba Pélieba Mariam Sylla Mamadou Samaké Hamadoun Sangho 《Open Journal of Pediatrics》 2024年第5期800-813,共14页
Introduction: Infant and child mortality is a worldwide concern, but developing countries such as Mali are more affected. The aim of this study was to investigate morbidity and factors associated with mortality in chi... Introduction: Infant and child mortality is a worldwide concern, but developing countries such as Mali are more affected. The aim of this study was to investigate morbidity and factors associated with mortality in children aged 1 month to 15 years. Methodology: This was a cross-sectional study which took place from January 1 to December 31, 2020 covering children aged 1 month to 15 years hospitalized at the Kalaban-Coro CSRéf. Data were entered into Excel and analyzed using SPSS version 20 software. Results: Five hundred children aged 1 months to 15 years were included. The age range 1 to 5 years (53.6%) and male sex (58.2%) were the most represented. Malaria (72.2%), acute respiratory infections (6.2%) and diarrhea/dehydration (3%) were the main morbidities. Mortality was estimated at 10.6%, and the two main causes of death were malaria (56.6%) and acute respiratory infections (7.54%). Univariate analysis revealed a statistically significant association between the dependent variable (death) and age (p Conclusion: This study confirms the high rate of infant and child morbidity and mortality in our health facilities. Strengthening human resources and intensifying behavior-change communication can help reverse the trend. 展开更多
关键词 Children Aged 1 Months to 15 years MORBIDITY Factors Associated with Mortality MORBIDITY
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Quality-adjusted life years and surgical waiting list:Systematic review of the literature
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作者 Roberto de la Plaza Llamas Lorena Ortega Azor +5 位作者 Marina Hernández Yuste Ludovica Gorini Raquel Aránzazu Latorre-Fragua Daniel Alejandro Díaz Candelas Farah Al Shwely Abduljabar Ignacio Antonio Gemio del Rey 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第4期1155-1164,共10页
BACKGROUND The quality-adjusted life year(QALY)is a metric that is increasingly used today in the field of health economics to evaluate the value of different medical treatments and procedures.Surgical waiting lists(S... BACKGROUND The quality-adjusted life year(QALY)is a metric that is increasingly used today in the field of health economics to evaluate the value of different medical treatments and procedures.Surgical waiting lists(SWLs)represent a pressing problem in public healthcare.The QALY measure has rarely been used in the context of surgery.It would be interesting to know how many QALYs are lost by patients on SWLs.AIM To investigate the relationship between QALYs and SWLs in a systematic review of the scientific literature.METHODS The study was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Statement.An unlimited search was carried out in PubMed,updated on January 19,2024.Data on the following variables were investigated and analyzed:Specialty,country of study,procedure under study,scale used to measure QALYs,the use of a theoretical or real-life model,objectives of the study and items measured,the economic value assigned to the QALY in the country in question,and the results and conclusions published.RESULTS Forty-eight articles were selected for the study.No data were found regarding QALYs lost on SWLs.The specialties in which QALYs were studied the most in relation to the waiting list were urology and general surgery,with 15 articles each.The country in which the most studies of QALYs were carried out was the United States(n=21),followed by the United Kingdom(n=9)and Canada(n=7).The most studied procedure was organ transplantation(n=39),including 15 kidney,14 liver,5 heart,4 lung,and 1 intestinal.Arthroplasty(n=4),cataract surgery(n=2),bariatric surgery(n=1),mosaicplasty(n=1),and septoplasty(n=1)completed the surgical interventions included.Thirty-nine of the models used were theoretical(the most frequently applied being the Markov model,n=34),and nine were real-life.The survey used to measure quality of life in 11 articles was the European Quality of Life-5 dimensions,but in 32 articles the survey was not specified.The willingness-to-pay per QALY gained ranged from$100000 in the United States to€20000 in Spain.CONCLUSION The relationship between QALYs and SWLs has only rarely been studied in the literature.The rate of QALYs lost on SWLs has not been determined.Future research is warranted to address this issue. 展开更多
关键词 Quality-adjusted life year Waitlist Quality of life SURGERY Systematic review
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Prevalence and Distribution of Tick-Borne Hemoparasites in Cattle from the Noun and Ndé Divisions of the West Region, Cameroon
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作者 Rostand Cedric Pami Mbitkebeyo Kingsley Tanyi Manchang +1 位作者 Corinne Raïssa Ngnameko Geraud C. Tasse 《Open Journal of Veterinary Medicine》 CAS 2024年第8期193-202,共10页
Background and Objective: Tick-borne hemoparasitic illnesses pose a serious threat to the well-being and productivity of cattle. This study aimed to investigate the prevalence of tick-borne hemoparasites in Cameroon, ... Background and Objective: Tick-borne hemoparasitic illnesses pose a serious threat to the well-being and productivity of cattle. This study aimed to investigate the prevalence of tick-borne hemoparasites in Cameroon, with a specific focus on the Noun and Nde Divisions of the West Region. Methodology: A total of 423 cattle from 10 villages in both divisions were included in the study. Blood smears were prepared and subjected to microscopic screening for Babesia and Anaplasma parasites. Results: The prevalence of Anaplasma was found to be 23.4%, while Babesia exhibited a seroprevalence of 17.3%. Samples from Institute of Agricultural Research for Development (IRAD) and Koupa Ngangnou demonstrated significantly higher prevalence rates, potentially influenced by climate variations affecting tick populations. Additionally, 17.3% of the animals exhibited low hematocrit levels, indicative of anemia. No significant associations were observed between the presence of hemoparasite infection and cattle characteristics. Conclusion: This study provides fundamental data on the extensive distribution and impact of tick-borne hemoparasites in a significant cattle-producing region of Cameroon. 展开更多
关键词 TICK-bornE hemoparasites CATTLE PREVALENCE Cameroon
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A Study on the Pedagogical Application of Chinese New Year Culture in International Chinese Language Education
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作者 Xiaoxuan Ma Yong Hu 《Journal of Contemporary Educational Research》 2024年第3期27-31,共5页
Culture teaching is an inseparable part of International Chinese Language Education,and it has great significance in international Chinese language teaching.Students can enhance their interest in Chinese language lear... Culture teaching is an inseparable part of International Chinese Language Education,and it has great significance in international Chinese language teaching.Students can enhance their interest in Chinese language learning and improve their learning effect through understanding the excellent traditional Chinese culture,at the same time,culture teaching can help to disseminate the Chinese culture and promote the development of a multicultural world.Taking the teaching of Chinese New Year culture as an example,we analyze the current teaching materials involving Chinese New Year culture with high popularity and acceptance,put forward effective teaching methods matching the feasibility of teaching Chinese New Year culture,and then present the specific teaching design of Chinese New Year culture,in order to provide references for the teaching of culture in International Chinese Language Education. 展开更多
关键词 International Chinese Language Education Chinese New year culture Pedagogical application
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Analysis of the Spirit of Struggle in the New Era Based on General Secretary Xi Jinping’s New Year’s Greetings in the Past Decade
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作者 Chengyu Wu 《Journal of Educational Theory and Management》 2024年第1期23-26,共4页
In order to realize the national rejuvenation,General Secretary Xi Jinping attaches great importance to the spiritual strength of struggle,and has repeatedly advocated that all people should exalt the spirit of strive... In order to realize the national rejuvenation,General Secretary Xi Jinping attaches great importance to the spiritual strength of struggle,and has repeatedly advocated that all people should exalt the spirit of strive on different occasions.According to his New Year’s greetings since 2014,Xi Jinping has illustrated the connotation of the spirit of enterprising,the necessity of carrying forward and the requirements for practicing the spirit of struggle from different perspectives,pointing out that all Chinese must keep in mind both domestic and international situations,strive in unity,work creative and industrious with the enthusiasm of seizing every minute,catch the opportunity and solve the problem,make substantial progress on the new journey to construct China into a great modern socialist country in all respects. 展开更多
关键词 New year greetings the spirit of struggle the requirements of the new era
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2017 was the Warmest Year on Record for the Global Ocean 被引量:8
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作者 Lijing CHENG Jiang ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2018年第3期261-263,共3页
2017 was the warmest year on record for the global ocean according to an updated Institute of Atmospheric Physics, Chinese Academy of Sciences (IAR CAS: http://english. iap.cas.cn/) ocean analysis.
关键词 was the Warmest year on Record for the Global Ocean IAP XBT
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Asymptotic Analysis of a Stochastic Model of Mosquito-Borne Disease with the Use of Insecticides and Bet Nets
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作者 Boubacar Sidiki Kouyaté Modeste N’zi 《Journal of Applied Mathematics and Physics》 2024年第1期305-329,共25页
Ross’ epidemic model describing the transmission of malaria uses two classes of infection, one for humans and one for mosquitoes. This paper presents a stochastic extension of a deterministic vector-borne epidemic mo... Ross’ epidemic model describing the transmission of malaria uses two classes of infection, one for humans and one for mosquitoes. This paper presents a stochastic extension of a deterministic vector-borne epidemic model based only on the class of human infectious. The consistency of the model is established by proving that the stochastic delay differential equation describing the model has a unique positive global solution. The extinction of the disease is studied through the analysis of the stability of the disease-free equilibrium state and the persistence of the model. Finally, we introduce some numerical simulations to illustrate the obtained results. 展开更多
关键词 Vector-borne Disease Epidemic Model Stochastic Delay Differential Equations Stochastic Stability Lyapunov Functional Technique
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Infinitely Many Solutions and a Ground-State Solution for Klein-Gordon Equation Coupled with Born-Infeld Theory
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作者 Fangfang Huang Qiongfen Zhang 《Journal of Applied Mathematics and Physics》 2024年第4期1441-1458,共18页
In this paper, we intend to consider a kind of nonlinear Klein-Gordon equation coupled with Born-Infeld theory. By using critical point theory and the method of Nehari manifold, we obtain two existing results of infin... In this paper, we intend to consider a kind of nonlinear Klein-Gordon equation coupled with Born-Infeld theory. By using critical point theory and the method of Nehari manifold, we obtain two existing results of infinitely many high-energy radial solutions and a ground-state solution for this kind of system, which improve and generalize some related results in the literature. 展开更多
关键词 Klein-Gordon Equation born-Infeld theory Infinitely Many Solutions Ground-State Solution Critical Point theory
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Seroprevalence of anti-HBs antibodies and the need for booster vaccination in children under 5 years of age born to HBsAg-negative mothers
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作者 Jannatin Nisa Arnindita Muhammad Miftahussurur +1 位作者 Bagus Setyoboedi Juniastuti 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2021年第9期410-416,共7页
Objective:To determine the proportion of HBV surface antigen(anti-HBs)antibody positive children under five years of age born to HBs Ag-negative mothers and to analyze the possible related factors following implementa... Objective:To determine the proportion of HBV surface antigen(anti-HBs)antibody positive children under five years of age born to HBs Ag-negative mothers and to analyze the possible related factors following implementation of a hepatitis B vaccination program for infants in Indonesia 22 years ago.Methods:Blood samples were taken from children under five years of age born to HBsAg-negative mothers who have completed primary vaccination series.Anti-HBs antibodies were determined by using rapid test.Data of age,gender,nutritional status,vaccination timing or vaccination compliance,and booster vaccination were collected from vaccination card.Results:Ninety children were enrolled,consisting of 47 females and 43 males with a mean age of 2.3 years.Twenty two(24.4%)children received booster vaccine between 18 and 24 months and 55(61.1%)were anti-HBs positive.Among factors of age,gender,nutritional status,compliance to vaccination and booster vaccine,only administration of booster vaccine was significantly associated with anti-HBs status(OR 5.45,95%CI 1.45,20.52).Children who received booster vaccine at age of 18-24 months were 5.45 times more likely to be anti-HBs positive than that of children who did not receive booster vaccine.Conclusions:Booster vaccine rate is low among children under 5 years of age but is associated with anti-HBs positivity.Booster vaccination may be required to improve anti-HBs seropositivity. 展开更多
关键词 hepatitis B vaccination Booster vaccine Children under five years
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Morphological changes of silver and bighead carp in the Yangtze River over the past 50 years 被引量:2
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作者 于红霞 唐文乔 李思发 《Zoological Research》 CAS CSCD 北大核心 2010年第6期651-656,共6页
Multivariate analysis was adopted to analyze 30 morphometrical characteristics of 121 one-year-old juvenile silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) bred during the 1950s ... Multivariate analysis was adopted to analyze 30 morphometrical characteristics of 121 one-year-old juvenile silver carp (Hypophthalmichthys molitrix) and bighead carp (Aristichthys nobilis) bred during the 1950s ("the former population") and 2008 ("the current population") and collected from the middle reach of the Yangtze River. The average discriminant accuracies of the former and current silver and bighead carp population were 94.2% and 98.0%, respectively. Discriminant analysis also revealed that significant differences in morphology occurred between the former and current populations of both carp in overall characteristics. One-way analysis of variance indicated that between former and current populations, silver carp showed highly significant differences (P0.01) in twelve of their characteristics and significant differences (P0.05) in eight of their characteristics, while bighead carp showed highly significant differences (P0.01) in eight of their characteristics and significant differences (P0.05) in eight of their characteristics. Six head morphology variables of the current silver and bighead carp were significantly or highly significantly larger than the former populations; fourteen characteristics of silver carp and ten characteristics of bighead carp of the current populations, mainly reflecting truck and tail morphology, were significantly or very significantly smaller than the former populations. Our results indicate that silver and bighead carp have developed a larger head and smaller truck and tail during the last 50 years. Due to such morphological changes, it seems apparent that the heads of these fish species need to be considered in regards to human diets, particularly in relation to economic and nutritious value. 展开更多
关键词 Silver carp Bighead carp 50 years breeding Morphological change Yangtze River
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Screening of Two Biocontrol Strains of Bacillus subtilis against Ginseng Soil-borne Disease and Their Antifungal Activities 被引量:5
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作者 于丽萍 姜竹 +2 位作者 王玉霞 张云湖 李晶 《Plant Diseases and Pests》 CAS 2011年第2期16-18,50,共4页
[ Objective] The paper was to obtain biocontrol strains with good control effects against ginseng soil-borne disease through screening. [ Method] Dilu- tion plate method and plate confrontation culture method were use... [ Objective] The paper was to obtain biocontrol strains with good control effects against ginseng soil-borne disease through screening. [ Method] Dilu- tion plate method and plate confrontation culture method were used to isolate and screen biocontrol bacteria from the rhizosphere soil of diseased ginseng. The strains were identified through morphology, physiological and biochemical characteristics and 16S rDNA. [ Result ] With Rhizoctonia solani, Fusarium oxysporum and Fu- sarium solani as the indicator strains, two biocontrol strains B59 and X1 with strong antagonistic effects were screened from the rhizosphere soil of diseased ginseng in Tieli farm of Heilongjiang Province, and they were identified to be Bacillus subtilis. The inhibition rates of two biocontrol strains against eight different fungi were all greater than 90%. The primary study indicated that B59 and X1 strains could secrete antifungal active substances. [ Conclusion] Two biocontrol Bacillus subti- lis strains 1359 and X1 all had strong antagonistic effect against ginseng soil-borne disease, which had certain potential for development and utilization. 展开更多
关键词 Ginseng soil-borne disease Bacillus subtilis SCREENING Antifungal activity
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基于学科素养的英语诗歌教学实践--以Seasons of the year为例 被引量:6
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作者 孙俊 《基础教育课程》 北大核心 2018年第20期40-44,共5页
英语诗歌是中学生需要接触的文本体裁之一。在日常英语教学中,教师要用好诗歌这一阅读素材,要依托诗歌文本,丰富学生的语言知识,培养语言技能;要引领学生赏析诗歌内涵,开发想象空间,提升思维品质;要适当链接中文诗歌,让学生体验诗歌意境... 英语诗歌是中学生需要接触的文本体裁之一。在日常英语教学中,教师要用好诗歌这一阅读素材,要依托诗歌文本,丰富学生的语言知识,培养语言技能;要引领学生赏析诗歌内涵,开发想象空间,提升思维品质;要适当链接中文诗歌,让学生体验诗歌意境,感受文化异同;要辅以课外诗歌,让学生内化课内感悟,提升学习能力。 展开更多
关键词 英语学科核心素养 英语诗歌教学 SEASONS of the year一课
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Wave equation tomographic velocity inversion method based on the Born/Rytov approximation 被引量:5
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作者 张凯 尹正 +1 位作者 李振春 陈永芮 《Applied Geophysics》 SCIE CSCD 2013年第3期314-322,358,359,共11页
This paper discusses Born/Rytov approximation tomographic velocity inversion methods constrained by the Fresnel zone. Calculations of the sensitivity kernel function and traveltime residuals are critical in tomographi... This paper discusses Born/Rytov approximation tomographic velocity inversion methods constrained by the Fresnel zone. Calculations of the sensitivity kernel function and traveltime residuals are critical in tomographic velocity inversion. Based on the Bom/Rytov approximation of the frequency-domain wave equation, we derive the traveltime sensitivity kemels of the wave equation on the band-limited wave field and simultaneously obtain the traveltime residuals based on the Rytov approximation. In contrast to single-ray tomography, the modified velocity inversion method improves the inversion stability. Tests of the near- surface velocity model and field data prove that the proposed method has higher accuracy and Computational efficiency than ray theory tomography and full waveform inversion methods. 展开更多
关键词 Tomographic inversion Fresnel zone sensitivity kernels Bom approximation Rytov approximation
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A Reverse-transcription Recombinase-aided Amplification Assay for the Rapid Detection of the Far-Eastern Subtype of Tick-borne Encephalitis Virus 被引量:7
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作者 WANG Qian Ying LI Fan +6 位作者 SHEN Xin Xin FU Shi Hong HE Ying LEI Wen Wen LIANG Guo Dong WANG Huan Yun MA Xue Jun 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2019年第5期357-362,共6页
Objective Tick-borne encephalitis virus(TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis(TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease.... Objective Tick-borne encephalitis virus(TBEV) is an emerging pathogen in Europe and North Asia that causes tick-borne encephalitis(TBE). A simple, rapid method for detecting TBEV RNA is needed to control this disease. Methods A reverse-transcription recombinase-aided amplification(RT-RAA) assay was developed. This assay can be completed in one closed tube at 39℃ within 30 minutes. The sensitivity and specificity of RT-RAA were validated using non-infectious synthetic RNA representing a fragment of the NS5 region of the wild-type(WT) TBEV genome and the Senzhang strain. Additionally, 10 batches of tick samples were used to evaluate the performance of the RT-RAA assay. Results The analytical limit of detection of the assay was 20 copies per reaction of the TBEV synthetic transcript and 3 plaque-forming units(pfu) per reaction of TBEV titers. With the specific assay, no signal due to other arboviruses was observed. Of the 10 batches of tick samples obtained from the Changbai Mountains of China, three were TBEV-positive, which was consistent with the results of the quantitative real-time PCR assay. Conclusion A rapid, highly sensitive, specific, and easy-to-use method was developed for the detection of the TBEV Far-Eastern subtype. 展开更多
关键词 Tick‐borne ENCEPHALITIS virus SUBTYPE Far‐eastern Detection RT‐RAA
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The ostracod assemblages and their environmental significance in the Chen Co area, southern Tibet in recent 1400 years 被引量:5
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作者 ZHU Liping, LI Yuanfang, LI Bingyuan(Inst. of Geographic Sciences and Natural Resources Research, CAS, Beijing 100101, China) 《Journal of Geographical Sciences》 SCIE CSCD 2002年第4期451-459,共9页
The CC1 core, with a length of 216 cm, was drilled in the west part of the Chen Co (Lake) in southern Tibet Plateau. The210Pb and137Cs measurement indicated that it was a consecutive sedimentary sequence since ca. 140... The CC1 core, with a length of 216 cm, was drilled in the west part of the Chen Co (Lake) in southern Tibet Plateau. The210Pb and137Cs measurement indicated that it was a consecutive sedimentary sequence since ca. 1400 years. The ostracoda and their assemblages under the level of 1 cm samples’ cutting interval were finished for this core to reveal the past environmental changes in the lake area. A total of 15 species of ostracods belonging to 7 genera in the core sediments had been identified. According to the ostracod distributions, abundances and preservations in the core, seven ostracod assemblages had been distinguished. The ostracod assemblages and their ecological features, together with the sediments dating decision were used to infer the past ca. 1400 years environmental changes of the Chen Co environmental evolutions in three stages, which had responded to the Medieval Ages Warm-period (MAW), the Little Ice Age (LIA) and modern warm period. The results show that the changes of the Chen Co environment had been mainly influenced by the climatic variations. The trend of the lake level fluctuations had been accorded with that of climatic variation during the past 1400 years. 展开更多
关键词 the Chen Co recent 1400 years environmental changes OSTRACODA
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The prevalence of vision impairment and refractive error in 3654 first year students at Tianjin Medical University 被引量:6
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作者 Xue-Ying Shi Yi-Feng Ke +3 位作者 Nan Jin Hong-Mei Zhang Rui-Hua Wei Xiao-Rong Li 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第10期1698-1703,共6页
AIM:To determine the prevalence of vision impairment(VI)and refractive error in first year university students at the Tianjin Medical University.METHODS:This is a cross-sectional observational cohort study of VI a... AIM:To determine the prevalence of vision impairment(VI)and refractive error in first year university students at the Tianjin Medical University.METHODS:This is a cross-sectional observational cohort study of VI and refractive error among first year university students at the Tianjin Medical University.The first year university students were involved in this study and were given a detailed questionnaire including age,birth date,and spectacle wearing history.A standardized ophthalmologic examination including visual acuity(VA),slit-lamp examination,non-cycloplegic auto-refraction,objective refraction,fundus photography,and examination of their spectacles were recorded.RESULTS:A total of 3654 participants were included in this study.Totally 3436(94.03%) individuals had VI in this population.Totally 150(4.10%) individuals had VI due to ocular disease,including amblyopia,congenital cataract,retinal atrophy or degeneration,strabismus,congenital nystagmus,refractive surgery orthokeratology.Totally 3286(89.93%) subjects had VI due to refractive error.Only 218(5.97%) students were emmetropia.Moreover,refractive error was the main cause for the VI(95.63%).Totally 3242(92.52%) students were myopia and the prevalence of mild,moderate,and high myopia subgroup was 27.05%,44.35%,and 21.26% respectively.Totally 44(1.29%) subjects were hyperopic.The rates of uncorrected visual acuity(UCVA),presenting visual acuity(PVA)and best corrected visual acuity(BCVA)which better than 20/20 in both eyes were 5.65%,22.32% and 82.13% respectively.The rates of correction,under correction and well correction in myopia subjects were 82.73%,84.39% and 15.61%,respectively. CONCLUSION:We present a high prevalence of refractive errors and high rates of under correction refractive error among first year university students.These results may help to promote vision protection work in young adults. 展开更多
关键词 vision impairment refractive error corrective status MYOPIA first year university students
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