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Addressing mucosal ulcers during orthodontic treatment:An urgent call for preventive strategies
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作者 Carlos M Ardila 《World Journal of Clinical Cases》 SCIE 2024年第30期6420-6424,共5页
Mucosal ulcers are a common yet often overlooked complication during orthodontic treatment,significantly impacting patient comfort and compliance.This letter aims to highlight the prevalence,potential causes,and manag... Mucosal ulcers are a common yet often overlooked complication during orthodontic treatment,significantly impacting patient comfort and compliance.This letter aims to highlight the prevalence,potential causes,and management strategies for mucosal ulcers in orthodontic patients.By reviewing recent literature and clinical observations,we underscore the necessity for proactive measures and tailored interventions to mitigate the incidence and severity of these lesions.Emphasizing the role of patient education and the use of protective devices,we call for a multidisciplinary approach to enhance patient care and treatment outcomes.This discussion is particularly relevant in the context of evolving orthodontic techniques and materials,which necessitate continuous adaptation of clinical practices to ensure patient safety and well-being. 展开更多
关键词 Mucosal ulcers Orthodontic treatment Patient comfort preventive strategies Clinical management Protective devices
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Transient Stability Preventive Control of Wind Farm Connected Power System Considering the Uncertainty
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作者 Yuping Bian Xiu Wan Xiaoyu Zhou 《Energy Engineering》 EI 2024年第6期1637-1656,共20页
To address uncertainty as well as transient stability constraints simultaneously in the preventive control of windfarm systems, a novel three-stage optimization strategy is established in this paper. In the first stag... To address uncertainty as well as transient stability constraints simultaneously in the preventive control of windfarm systems, a novel three-stage optimization strategy is established in this paper. In the first stage, the probabilisticmulti-objective particle swarm optimization based on the point estimate method is employed to cope with thestochastic factors. The transient security region of the system is accurately ensured by the interior point methodin the second stage. Finally, the verification of the final optimal objectives and satisfied constraints are enforcedin the last stage. Furthermore, the proposed strategy is a general framework that can combine other optimizationalgorithms. The proposed methodology is tested on the modified WSCC 9-bus system and the New England 39-bussystem. The results verify the feasibility of the method. 展开更多
关键词 Transient preventive control chance-constrained programming multi-objective PSO TSCOPF wind farm
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Evaluation of the effectiveness of preventive nursing measures for pressure injuries in patients in the neurology intensive care unit
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作者 Rong Zhang Peng-Xin Ma Juan-Juan Zhang 《World Journal of Clinical Cases》 SCIE 2024年第19期3807-3814,共8页
BACKGROUND Patients in neurology intensive care units(ICU)are prone to pressure injuries(PU)due to factors such as severe illness,long-term bed rest,and physiological dysfunction.PU not only causes pain and complicati... BACKGROUND Patients in neurology intensive care units(ICU)are prone to pressure injuries(PU)due to factors such as severe illness,long-term bed rest,and physiological dysfunction.PU not only causes pain and complications to patients,but also increases medical burden,prolongs hospitalization time,and affects the recovery process.AIM To evaluate and optimize the effectiveness of pressure injury prevention nursing measures in neurology ICU patients.METHODS A retrospective study was conducted,and 60 patients who were admitted to the ICU of the Department of Neurology were selected and divided into an observation group and a control group according to the order of admission,with 30 people in each group.The observation group implemented pressure injury prevention and nursing measures,while the control group adopted routine care.RESULTS Comparison between observation and control groups following pressure injury prevention nursing intervention revealed significantly lower incidence rates in the observation group compared to the control group at 48 h(8.3%vs 26.7%),7 d(16.7%vs 43.3%),and 14 d(20.0%vs 50.0%).This suggests a substantial reduction in pressure injury incidence in the observation group,with the gap widening over time.Additionally,patients in the observation group exhibited quicker recovery,with a shorter average time to get out of bed(48 h vs 72 h)and a shorter average length of stay(12 d vs 15 d)compared to the control group.Furthermore,post-intervention,patients in the observation group reported significantly improved quality of life scores,including higher scores in body satisfaction,feeling and function,and comfort(both psychological and physiological),indicating enhanced overall well-being and comfort following the implementation of pressure injury prevention nursing measures.CONCLUSION Implementing pressure injury preventive care measures for neurology ICU patients will have better results. 展开更多
关键词 Neurology intensive care units Pressure injury preventive care Effect evaluation Optimization research Prognostic effect
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Reliability-BasedModel for Incomplete Preventive ReplacementMaintenance of Photovoltaic Power Systems
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作者 Wei Chen Ming Li +2 位作者 Tingting Pei Cunyu Sun Huan Lei 《Energy Engineering》 EI 2024年第1期125-144,共20页
At present,the operation and maintenance of photovoltaic power generation systems mainly comprise regular maintenance,breakdown maintenance,and condition-based maintenance,which is very likely to lead to over-or under... At present,the operation and maintenance of photovoltaic power generation systems mainly comprise regular maintenance,breakdown maintenance,and condition-based maintenance,which is very likely to lead to over-or under-repair of equipment.Therefore,a preventive maintenance and replacement strategy for PV power generation systems based on reliability as a constraint is proposed.First,a hybrid failure function with a decreasing service age factor and an increasing failure rate factor is introduced to describe the deterioration of PV power generation equipment,and the equipment is replaced when its reliability drops to the replacement threshold in the last cycle.Then,based on the reliability as a constraint,the average maintenance cost and availability of the equipment are considered,and the non-periodic incomplete maintenance model of the PV power generation system is established to obtain the optimal number of repairs,each maintenance cycle and the replacement cycle of the PV power generation system components.Next,the inverter of a PV power plant is used as a research object.The model in this paper is compared and analyzed with the equal cycle maintenance model without considering reliability and the maintenance model without considering the equipment replacement threshold,Through model comparison,when the optimal maintenance strategy is(0.80,4),the average maintenance cost of this paper’s model are decreased by 20.3%and 5.54%and the availability is increased by 0.2395% and 0.0337%,respectively,compared with the equal-cycle maintenance model without considering the reliability constraint and the maintenance model without considering the equipment replacement threshold.Therefore,this maintenance model can ensure the high reliability of PV plant operation while increasing the equipment availability to improve the system economy. 展开更多
关键词 RELIABILITY photovoltaic power system average maintenance cost AVAILABILITY incomplete preventive maintenance hybrid failure rate
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Influencing factors and preventive measures of infectious complications after intestinal resection for Crohn’s disease
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作者 Shi-Rong Lv Xiao Huang +4 位作者 Li-Yun Zhou Jie Shi Chu-Chu Gong Ming-Ke Wang Ji-Shun Yang 《World Journal of Gastrointestinal Surgery》 SCIE 2024年第10期3363-3370,共8页
The incidence of Crohn’s disease(CD)has increased in recent years,with most patients requiring intestinal resection.Complications after intestinal resection for CD can lead to poor prognosis and recurrence,among whic... The incidence of Crohn’s disease(CD)has increased in recent years,with most patients requiring intestinal resection.Complications after intestinal resection for CD can lead to poor prognosis and recurrence,among which infectious complic-ations are the most common.This study aimed to investigate the common risk factors,including medications,preoperative nutritional status,surgery-related factors,microorganisms,lesion location and type,and so forth,causing infectious complications after intestinal resection for CD,and to propose corresponding preventive measures.The findings provided guidance for identifying suscept-ibility factors and the early intervention and prevention of infectious complic-ations after intestinal resection for CD in clinical practice. 展开更多
关键词 Crohn’s disease Intestinal resection Postoperative infectious complications Influencing factors preventive measures
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Low Birth Weight and Intermittent Preventive Treatment of Malaria in Pregnant Women in Lomé (Togo) in 2021: A Cross-Sectional Study
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作者 Roméo Mèdéssè Togan Ounoo Elom Takassi +7 位作者 Fifonsi Gbeasor-Komlanvi Arnold Junior Sadio Rodion Yao Konu Martin Kouame Tchankoni Iwone Oumarou Adama Latame Komla Adoli Dzayissé Yawo Atakouma Didier Koumavi Ekouévi 《Open Journal of Epidemiology》 2024年第1期31-44,共14页
Background: Since 2012, the World Health Organization has recommended intermittent preventive treatment with sulfadoxine-pyrimethamine (IPT-SP) to prevent malaria-related complications in pregnant women. Ten years fol... Background: Since 2012, the World Health Organization has recommended intermittent preventive treatment with sulfadoxine-pyrimethamine (IPT-SP) to prevent malaria-related complications in pregnant women. Ten years following these recommendations, we conducted this study to estimate the coverage for three doses of IPT-SP (IPT3) as well as the prevalence of low birth weight (LBW), and its associated factors in Lomé (Togo) in 2021. Methods: A cross-sectional study was conducted between January and March 2021. An exhaustive recruitment of women and their newborns was carried out in the maternity wards of the Sylvanus Olympio University Hospital Center. Data from antenatal consultations and clinical data of the newborns were collected. Multivariate logistic regression was carried out to determine factors associated with LBW. Results: A total of 252 mother-child pairs were included in this study. Median age of the mothers was 27 years, IQR [24-31]. More than a third (35.3%) of the mothers were primigravida. IPT3 coverage was 66.7% and 14.7% of newborns had a LBW. The prevalence of LBW was 33.3% [23.3-43.4] in women who had received fewer than 3 doses of IPT-SP and 5.4% [2.0-8.8] in those who had received at least 3 doses of IPT-SP (p Conclusion: Ten years following recommendations of the WHO on IPT-SP, malaria prevention based on IPT-SP is not optimal among pregnant women in Lomé, and the proportion of LBW children remains high. Actions to strengthen the three-dose IPT-SP policy are needed to prevent malaria and its consequences among newborns in Togo. 展开更多
关键词 MALARIA Intermittent preventive Treatment Low Birth Weight TOGO
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The Preventive Effect of Comprehensive Nursing Intervention on Arteriovenous Fistula Failure in Patients in the Hemodialysis Room
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作者 Xuemei Sun 《Journal of Clinical and Nursing Research》 2024年第2期111-116,共6页
Objective:To explore the preventive effect of comprehensive nursing intervention on arteriovenous fistula failure in patients in the hemodialysis room.Methods:82 patients with arteriovenous fistula in the hemodialysis... Objective:To explore the preventive effect of comprehensive nursing intervention on arteriovenous fistula failure in patients in the hemodialysis room.Methods:82 patients with arteriovenous fistula in the hemodialysis chamber treated in our hospital from July 2022 to October 2023 were selected as the research subjects.The random number table method divided them into a control group and an experimental group of 41 cases each.The control group received general nursing intervention measures,while the experimental group underwent comprehensive nursing intervention.The incidence of complications(internal fistula failure,bleeding,thrombosis,infection),psychological emotions(SAS scale,SDS scale),quality of life(physical pain,physiological function,emotional function,social function),and nursing satisfaction(very satisfied,basically satisfied,satisfied,dissatisfied)were compared between the two groups of patients.Results:The incidence of complications in the experimental group(4,9.76%)was significantly lower than that in the control group(29,70.73%);the SAS scores and SDS scores of the patients in the experimental group after intervention were both lower than those in the control group;the quality of life score(physical pain,physiological function,emotional function,and social function)was all higher than those of the control group;the post-intervention nursing satisfaction of the experimental group(40,97.57%)was also significantly higher than that of the control group(29,73.17%);and the listed differences were statistically significant(P<0.01).Conclusion:For patients with hemodialysis ventricular arteriovenous fistula failure,comprehensive nursing intervention can reduce the incidence of complications,relieve anxiety and stress,improve quality of life and nursing satisfaction,and achieve better preventive effects. 展开更多
关键词 Comprehensive care Patients in hemodialysis room Arteriovenous fistula failure preventive effect
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Diabetes and susceptibility to COVID-19:Risk factors and preventive and therapeutic strategies
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作者 Jing-Wen Liu Xiao Huang +1 位作者 Ming-Ke Wang Ji-Shun Yang 《World Journal of Diabetes》 SCIE 2024年第8期1663-1671,共9页
Coronavirus disease 2019(COVID-19)is a highly infectious disease caused by a novel human coronavirus called severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Diabetes is a well-known risk factor for infectio... Coronavirus disease 2019(COVID-19)is a highly infectious disease caused by a novel human coronavirus called severe acute respiratory syndrome coronavirus 2(SARS-CoV-2).Diabetes is a well-known risk factor for infectious diseases with high prevalence and increased severity.Here,we elucidated the possible factors for the increased vulnerability of diabetic patients to SARS-CoV-2 infection and the more severe COVID-19 illness.The worsened prognosis of patients with both COVID-19 and diabetes may be attributable to host receptor angiotensinconverting enzyme 2-assisted viral uptake.Moreover,insulin resistance is often associated with impaired mucosal and skin barrier integrity,resulting in microbiota dysbiosis,which increases susceptibility to viral infections.It may also be associated with higher levels of pro-inflammatory cytokines resulting from an impaired immune system in diabetics,inducing a cytokine storm and excessive inflammation.This review describes diabetes mellitus and its complications,explains the risk factors,such as disease characteristics and patient lifestyle,which may contribute to the high susceptibility of diabetic patients to COVID-19,and discusses preventive and therapeutic strategies for COVID-19-positive diabetic patients. 展开更多
关键词 Diabetes mellitus SARS-CoV-2 COVID-19 SUSCEPTIBILITY Prevention Treatment
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Prevalence and Individual-Level Determinants of Uptake of Three or More Doses of Sulphadoxine-Pyrimethamine for Intermittent Preventive Treatment of Malaria in Pregnancy in Busia County, Kenya
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作者 Anne Nduta Miatu Betsy Rono Cheriro Kamija Samuel Phiri 《Open Journal of Epidemiology》 2024年第3期405-418,共14页
Background: Malaria in pregnancy causes maternal anemia, low birth weight, intrauterine growth retardation, and preterm deliveries. In malaria-endemic regions in Kenya, percentage of pregnant women hospitalized with m... Background: Malaria in pregnancy causes maternal anemia, low birth weight, intrauterine growth retardation, and preterm deliveries. In malaria-endemic regions in Kenya, percentage of pregnant women hospitalized with malaria reach up to 60%. WHO recommends at least three doses of sulphadoxine pyrimethamine for Intermittent Preventive Treatment of Malaria in Pregnancy (IPTp) antenatally. This study sought to ascertain the prevalence and individual-level factors influencing the uptake of IPTp-SP3+. Methods: A facility-based cross-sectional study at Busia County Referral Hospital. 384 mothers were consecutively sampled at the maternity unit during delivery. Semi-structured questionnaires were used to collect data. Odds ratio (OR) and adjusted OR were used to determine statistical significance of individual factors influencing uptake of three or more IPTp-SP. Results: 43.0% of participants took IPTp-SP3+. Individual factors that affected the uptake of IPTp-SP3+ included starting ANC visits in the first trimester (adjusted odds ratio (aOR) = 2.1, 95% CI: 1.23 – 3.67, p = 0.046), having more than four ANC visits (aOR = 3.1, 95% CI: 1.49 – 6.50, p = 0.002), having a higher monthly income (aOR = 2.6, 95% CI: 1.24 – 5.36, p = 0.012), being aware of the advantages of IPTp-SP medications (aOR = 3.7, 95% CI: 1.40 – 9.74, p = 0.008), and having a positive attitude toward ANC services (aOR = 3.2, 95% CI: 1.61 – 6.31, p = 0.001). Conclusion: Less than half of the pregnant mothers are complyingIPTp-SP3+. There should be aggressive efforts by the County and National Ministries of Health promoting initiation of ANC attendance early and attendance of all the recommended eight visits together with ensuring availability of the drugs. 展开更多
关键词 Malaria in Pregnancy Antenatal Clinic Intermittent Prevention of Malaria in Pregnancy DOSAGE UPTAKE Sulphadoxine-Pyrimethamine and Individual Level Factors
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Characteristics of coal resources in China and statistical analysis and preventive measures for coal mine accidents 被引量:3
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作者 Chaolin Zhang Peizhong Wang +2 位作者 Enyuan Wang Dapeng Chen Chao Li 《International Journal of Coal Science & Technology》 EI CAS CSCD 2023年第2期45-57,共13页
In the process of green and smart mine construction under the context of carbon neutrality,China's coal safety situation has been continuously improved in recent years.In order to recognize the development of coal... In the process of green and smart mine construction under the context of carbon neutrality,China's coal safety situation has been continuously improved in recent years.In order to recognize the development of coal production in China and prepare for future monitoring and prevention of safety incidents,this study mainly elaborated on the basic situation of coal resources and national mining accidents over the past five years(2017-2021),from four dimensions(accident level,type,region,and time),and then proposed the preventive measures based on accident statistical laws.The results show that the storage of coal resources has obvious geographic characteristics,mainly concentrated in the Midwest,with coal resources in Shanxi and Shaanxi accounting for about 49.4%.The proportion of coal consumption has dropped from 70.2%to 56%between 2011 and 2021,but still accounts for more than half of the all.Meanwhile,the accident-prone areas are positively correlated with the amount of coal production.Among different levels of coal mine accidents,general accidents had the highest number of accidents and deaths,with 692 accidents and 783 deaths,accounting for 87.6%and 54.64%respectively.The frequency of roof,gas,and transportation accidents is relatively high,and the number of single fatalities caused by gas accidents is the largest,about 4.18.In terms of geographical distribution of accidents,the safety situation in Shanxi Province is the most severe.From the time distribution of coal mine accidents,the accidents mainly occurred in July and August,and rarely occurred in February and December.Finally,the"4+4"safety management model is proposed,combining the statistical results with coal production in China.Based on the existing health and safety management systems,the manage-ments are divided into four sub-categories,and more specific measures are suggested. 展开更多
关键词 Resource characteristics Coal mine accidents Security situation Safety 4+4 model preventive measures
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Risk factors, preventive interventions, overlapping symptoms, and clinical measures of delirium in elderly patients 被引量:1
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作者 Xi Mei Yue-Hong Liu +1 位作者 Ya-Qing Han Cheng-Ying Zheng 《World Journal of Psychiatry》 SCIE 2023年第12期973-984,共12页
Delirium is an acute reversible neuropsychiatric syndrome caused by multiple factors.It is associated with many adverse clinical outcomes including cognitive impairment,functional decline,prolonged hospitalization,and... Delirium is an acute reversible neuropsychiatric syndrome caused by multiple factors.It is associated with many adverse clinical outcomes including cognitive impairment,functional decline,prolonged hospitalization,and increased nursing service.The prevalence of delirium was high in department of cardiology,geriatric,and intensive care unit of hospital.With the increase in the aged population,further increases in delirium seem likely.However,it remains poorly recognized in the clinical practice.This article comprehensively discusses the latest research perspectives on the epidemiological data,risk factors,preventive interventions,overlapping symptoms,and clinical measures of delirium,including specific measures to manage delirium in clinical real-world situations.This article helps readers improve their knowledge and understanding of delirium and helps clinicians quickly identify and implement timely therapeutic measures to address various delirium subtypes that occur in the clinical settings to ensure patients are treated as aggressively as possible. 展开更多
关键词 DELIRIUM Risk factors preventive interventions Research progress REVIEW Clinical practice
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Joint Optimization of Imperfect Preventive Maintenance and Production Scheduling for Single Machine Based on Game Theory Method
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作者 Zuhua Jiang Jiawen Hu +2 位作者 Hongming Zhou Peiwen Ding Jiankun Liu 《Journal of Harbin Institute of Technology(New Series)》 CAS 2023年第4期15-24,共10页
In this study,an optimization model of a single machine system integrating imperfect preventive maintenance planning and production scheduling based on game theory is proposed.The costs of the production department an... In this study,an optimization model of a single machine system integrating imperfect preventive maintenance planning and production scheduling based on game theory is proposed.The costs of the production department and the maintenance department are minimized,respectively.Two kinds of three-stage dynamic game models and a backward induction method are proposed to determine the preventive maintenance(PM)threshold.A lemma is presented to obtain the exact solution.A comprehensive numerical study is provided to illustrate the proposed maintenance model.The effectiveness is also validated by comparison with other two existed optimization models. 展开更多
关键词 game theory imperfect preventive maintenance production scheduling single machine system
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Advances in Research of Epidemic Lung Preventive Mixture
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作者 Meiyan QIU Bing QING +1 位作者 Wen ZHONG Jiangcun WEI 《Medicinal Plant》 CAS 2023年第4期106-108,共3页
This paper summarizes the Epidemic Lung Preventive Mixture from three aspects of research status, development trends and prospects, so as to deepen the understanding of Epidemic Lung Preventive Mixture and provide a m... This paper summarizes the Epidemic Lung Preventive Mixture from three aspects of research status, development trends and prospects, so as to deepen the understanding of Epidemic Lung Preventive Mixture and provide a more detailed theoretical basis for its further clinical research and development. 展开更多
关键词 Epidemic Lung preventive Mixture Preparation process Quality standard Cinnamomi Ramulus(Guizhi) Atractylodis Rhizoma(Cangzhu).
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Preventive and Therapeutic Effects of New Fungicides on Rice Blast
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作者 Jinqi FENG Aiqing FENG +3 位作者 Xiaoyuan ZHU Jianyuan YANG Shen CHEN Jing SU 《Asian Agricultural Research》 2023年第6期33-35,共3页
[Objectives]The paper was to identify the characteristics and the potency of new fungicides to rice blast disease,and study their preventive and therapeutic effects on the disease.[Methods]Six new and conventional fun... [Objectives]The paper was to identify the characteristics and the potency of new fungicides to rice blast disease,and study their preventive and therapeutic effects on the disease.[Methods]Six new and conventional fungicides with different mechanisms of action were selected to compare their preventive and therapeutic effects on rice seedling blast in greenhouse.[Results]The agents which showed to be highly efficacious in blast prevention(greater than 90%)were 25%pyraclostrobin EC,20%fenoxanil SC,75%tricyclazole WP and 50%prochloraz-manganese WP sprayed at the dosages of 112.5-150,180-360,270-450 and 450-600 g/ha,respectively.The therapeutic effect of new fungicides 25%pyraclostrobin EC and 50%prochloraz-manganese WP on rice blast were above 90%when the dosages were 90-150 and 360-600 g/ha,respectively.The therapeutic effect of the conventional fungicide 40%isoprothiolane EC on rice blast was 69.04%when the dosage was 480 g/ha,while those of other fungicides were worse.[Conclusions]Both 25%pyraclostrobin EC and 50%prochloraz-manganese WP have good preventive and therapeutic effects on rice blast,which will provide a reference for the use of these fungicides in the field. 展开更多
关键词 Rice blast FUNGICIDE preventive effect Therapeutic effect
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Adherence to Preventive Measures during the COVID-19 Pandemic among University Students in Sudan
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作者 Einas Mustafa Mudawi Ahmed Sahar Moawia Balla Elnour +5 位作者 Sozan M. Abdelkhalig Tayseer Abdelmotalib Ahmed Taha Sulafa Abdelbagi Mustafa Ahmed Jalal Abdelrasool Hassan Eltaib Najad G. Mustafa Samar Moawia Balla Elnour 《Open Journal of Internal Medicine》 2023年第4期408-426,共19页
Background: Coronavirus disease 2019, otherwise known as COVID-19, emerged in December of 2019. COVID-19 spreads through an airborne transmission route. Preventive measures were described to help decrease the spread o... Background: Coronavirus disease 2019, otherwise known as COVID-19, emerged in December of 2019. COVID-19 spreads through an airborne transmission route. Preventive measures were described to help decrease the spread of COVID-19 worldwide. There were a number of preventive measures that were globally adopted: social distance of at least 1 meter, mask wearing, washing hands for 20 seconds, and covering the mouth and nose if the person sneezes or coughs. Methods: A descriptive cross-sectional study among 362 students from the International University of Africa, Sudan, was carried out between August 2021 and September 2022. Statistical Package for Social Sciences version 26 was used for data analysis;frequency and percentage were used to describe the qualitative variables. A chi-square test was used for association analysis;a P-value ≤ 0.05 was considered statistically significant. Results: Among study participants, the females were 70.9%;most were 20 - 23 years old (73.6%). 54.2% were vaccinated against COVID-19;83.6% had good knowledge regarding the mode of transmission, and 76.1% stayed in during quarantine. 80.6% of participants understood social distancing correctly. 76.1% of males and 45.1% of females started or completed vaccination (P ≤ 0.05). 51.4% of males and 81.3% of females adhered to preventive measures (P ≤ 0.05). Conclusions: It is important to target health education campaigns and interventions to improve adherence to preventive measures among university students. Although the pandemic is coming to an end, a lesson should be learned from it, and future preparation should be employed. 展开更多
关键词 SUDAN COVID-19 preventive Measures ADHERENCE
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Wind Turbine Optimal Preventive Maintenance Scheduling Using Fibonacci Search and Genetic Algorithm
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作者 Ekamdeep Singh Sajad Saraygord Afshari Xihui Liang 《Journal of Dynamics, Monitoring and Diagnostics》 2023年第3期157-169,共13页
Maintenance scheduling is essential and crucial for wind turbines (WTs) to avoid breakdowns andreduce maintenance costs. Many maintenance models have been developed for WTs’ maintenance planning, suchas corrective, p... Maintenance scheduling is essential and crucial for wind turbines (WTs) to avoid breakdowns andreduce maintenance costs. Many maintenance models have been developed for WTs’ maintenance planning, suchas corrective, preventive, and predictive maintenance. Due to communities’ dependence on WTs for electricityneeds, preventive maintenance is the most widely used method for maintenance scheduling. The downside tousing this approach is that preventive maintenance (PM) is often done in fixed intervals, which is inefficient. In thispaper, a more detailed maintenance plan for a 2 MW WT has been developed. The paper’s focus is to minimize aWT’s maintenance cost based on a WT’s reliability model. This study uses a two-layer optimization framework:Fibonacci and genetic algorithm. The first layer in the optimization method (Fibonacci) finds the optimal numberof PM required for the system. In the second layer, the optimal times for preventative maintenance and optimalcomponents to maintain have been determined to minimize maintenance costs. The Monte Carlo simulationestimates WT component failure times using their lifetime distributions from the reliability model. The estimatedfailure times are then used to determine the overall corrective and PM costs during the system’s lifetime. Finally,an optimal PM schedule is proposed for a 2 MW WT using the presented method. The method used in this papercan be expanded to a wind farm or similar engineering systems. 展开更多
关键词 cost-based maintenance scheduling genetic algorithm hierarchical optimization preventive maintenance reliability modeling wind turbine maintenance policy
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Periodical Inspections and Delay Replacement Model Based on Age Preventive Replacement Policy 被引量:1
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作者 王文彬 王慧颖 彭锐 《Journal of Donghua University(English Edition)》 EI CAS 2014年第6期744-746,752,共4页
Periodical inspections and an age-based preventive replacement( APR) model were proposed based on a two-stage failure process for a single component system. Inspection activities were performed at regular intervals. O... Periodical inspections and an age-based preventive replacement( APR) model were proposed based on a two-stage failure process for a single component system. Inspection activities were performed at regular intervals. Once the system was identified to be at defective state by inspection,a maintenance decision needed to be made that whether to replace the defective system immediately or wait till the preset APR time. So a threshold was introduced into the model and called as inspection-based preventive replacement( IPR) threshold. If the distance from the defect identification point to the APR time was longer than the threshold, a preventive replacement( PR) action was made; otherwise PR action was to wait till the APR time. Two models were proposed and compared,and a numerical example was conducted to illustrate the applicability of the model. 展开更多
关键词 delay-time INSPECTION age-based preventive replacement(APR) inspection-based preventive replacement(IPR) preventive maintenance(PM)
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Single-machine scheduling with preventive periodic maintenance and resumable jobs in remanufacturing system 被引量:2
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作者 刘碧玉 陈伟达 《Journal of Southeast University(English Edition)》 EI CAS 2012年第3期349-353,共5页
A single-machine scheduling with preventive periodic maintenance activities in a remanufacturing system including resumable and non-resumable jobs is studied.The objective is to find a schedule to minimize the makespa... A single-machine scheduling with preventive periodic maintenance activities in a remanufacturing system including resumable and non-resumable jobs is studied.The objective is to find a schedule to minimize the makespan and an LPT-LS algorithm is proposed.Non-resumable jobs are first scheduled in a machine by the longest processing time(LPT) rule,and then resumable jobs are scheduled by the list scheduling(LS) rule.And the worst-case ratios of this algorithm in three different cases in terms of the value of the total processing time of the resumable jobs(denoted as S2) are discussed.When S2 is longer than the spare time of the machine after the non-resumable jobs are assigned by the LPT rule,it is equal to 1.When S2 falls in between the spare time of the machine by the LPT rule and the optimal schedule rule,it is less than 2.When S2 is less than the spare time of the machine by the optimal schedule rule,it is less than 2.Finally,numerical examples are presented for verification. 展开更多
关键词 single-machine scheduling preventive periodic maintenance resumable jobs LPT-LS algorithm
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Effects of preventive acupuncture or moxibustion at the Guanyuan acupoint on expression of interleukin-2 and its receptors in hypothalamus, serum, and uterus of menopausal rats 被引量:5
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作者 Xiaohong Li Yuwei He +7 位作者 Jieping Xie Lufen Zhang Dengfang Zhou Jinghui Zhai Rui Zhan Jun Zhou Limin Qu Yangchun Tian 《Neural Regeneration Research》 SCIE CAS CSCD 2008年第1期49-52,共4页
BACKGROUND: Previous studies have indicated preventive acupuncture and moxibustion at the Guanyuan point have positive effects on the immune system of menopausal rats. OBJECTIVE: To observe the effects of preventive... BACKGROUND: Previous studies have indicated preventive acupuncture and moxibustion at the Guanyuan point have positive effects on the immune system of menopausal rats. OBJECTIVE: To observe the effects of preventive acupuncture or moxibustion at the Guanyuan point on interleukin-2 (IL-2) and its receptor (IL-2R mRNA) levels in hypothalamus, serum, and uterus of menopausal rats. DESIGN: Randomized control animal experiment. SETTING: School of Acupuncture and Moxibustion, Beijing University of Chinese Medicine. MATERIALS: This study was performed at the Laboratory of Beijing University of Chinese Medicine from November 2004 to July 2005. The vaginal smear method was used to determine the estrus cycle of 9.5-month-old Sprague Dawley (SD) female rats. Three continuous estrus cycles were measured, and 160 rats with estrus cycle disorder, weighing (300 _+ 20) g, were included in this study. The rats were randomly divided into four groups: preventive acupuncture group (n =48), preventive moxibustion group (n =48), model groups (n =48), and 10-month-old group (n =16). Sixteen 3.5-month-old healthy SD female rats, weighing (240 ± 20) g, were also assigned to the young group. All rats were clean grade and were purchased from the Laboratory Animal Center, Beijing University of Chinese Medicine. The experiment was in accordance with animal ethics standards. METHODS: Acupuncture was applied to the preventive acupuncture group at 10 months of age. The needle was inserted upward and perpendicularly two fen to a point that was two fen below the Guanyuan point. The rats freely moved around during needle retention (20 minutes). Acupuncture was administered twice a week and continued for eight weeks. A moxa cone (small) moxibustion was applied to the preventive moxibustion group at 10 months of age. The rats were caught gently and kept at the same position as the preventive acupuncture group. The moxa cone was ignited and held to the Guanyuan point directly. Only one moxa cone was used each time. After moxibustion, the local skin turned slightly red. Moxibustion was used twice a week and continued for eight weeks. Nothing except gently catching and lying was administered to the model group and the young group. MAIN OUTCOME MEASURES: Radioimmunoassay, in situ hybridization, and similar methods were employed to detect IL-2 in serum and the uterus, as well as IL-2R mRNA expression in the hypothalamus and uterus arcuate nuclei, of the preventive acupuncture group, preventive moxibustion group, model groups (at 12, 14, and 16 months), 10 month old group (at 10 months), and the young group (at 4 months). RESULTS: All 176 rats were included in the final analysis. (1) IL-2R mRNA: IL-2R mRNA expression decreased significantly in the uterus of 12-, 14-, and 16-month-old model groups and in the hypothalamus of 14- and 16-month-old model groups (P 〈 0.05-0.01). Compared to the same month-aged model groups, the expression of IL-2R mRNA increased significantly in the hypothalamus and uterus of 16-month-old preventive acupuncture or moxibustion groups (P 〈 0.05-0.01).(2) IL-2:IL-2 in serum of 12- and 14-month-old model groups and in the uterus of 12-, 14-, and 16-month-old model groups decreased significantly compared to the young group (P 〈 0.05-0.01). IL-2 serum levels increased significantly in the 16-month-old group with preventive moxibustion; in addition, IL-2 expression levels increased significantly in the uterus of the 12-month-old group with preventive moxibustion, as well as the 12- and 16-month-old groups with preventive acupuncture (P 〈 0.05-0.01). CONCLUSION: As a rat ages and becomes menopausal, IL-2R mRNA expression in the hypothalamus and uterus, as well as IL-2 levels in the serum and uterus, decrease. However, preventive acupuncture and preventive moxibustion can repress the decrease to some extent. This effect is even greater in the late stages of menopause (16-month-old rats). 展开更多
关键词 preventive acupuncture preventive moxibustion GUANYUAN IL-2 IL-2R mRNA menopausal rats
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Screening of Saprolegniasis Preventive Drugs for Golden Trout (Oncorhynchus mykiss) Fertilized Eggs During Hatching
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作者 李绍戊 刘红柏 《Agricultural Science & Technology》 CAS 2015年第9期1981-1984,1988,共5页
In order to screen the effective preventive drugs for saprolegniasis occurred during hatching of the fertilized eggs of golden trout, effects of two kinds of self-made Chinese herbal compounds(AB) and two kinds of c... In order to screen the effective preventive drugs for saprolegniasis occurred during hatching of the fertilized eggs of golden trout, effects of two kinds of self-made Chinese herbal compounds(AB) and two kinds of chemical bactericides(peroxyacetic acid andhydrogen peroxide, CD) with three disinfection concentrations were compared in this study. The fertilized eggs of golden trout were randomly divided into 13 groups, each group with two parallels of 1 000 eggs. Drugs at high,medium and low concentration were respectively used to immerse the fertilized eggs35 min for disinfection once a day. The numbers of live and dead eggs were recorded each day before disinfection and the numbers of survival eyed eggs were counted in each experimental group after finishing the whole test. The results indicated that all of four kinds of drugs used here had a certain effect on prevention and control of saprolegniasis during hatching of fertilized eggs of golden trout, and also showed a correlation between the concentrations and effects. After the selection of several drugs, we found that group B-medium, C-medium and D-high exhibited the most remarkable effects on control of saprolegniasis. However, careful consideration should be given to chemical drugs residues and their potential hazard to the eyed eggs. Therefore, Chinese herbal compound B was suggested to be used for prevention and control of saprolegniasis to achieve the healthy aquaculture. And the concentration and operation time of Chinese herbal compound B should be strictly controlled when used in disinfection of fertilized eggs. 展开更多
关键词 Golden trout(Oncorhynchus mykiss) Fertilized eggs SAPROLEGNIASIS preventive drugs
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