Chongqing

重庆
  • 文章类型: Journal Article
    目的:本研究旨在调查重庆男性的人乳头瘤病毒(HPV)感染和基因分型,并分析与年龄相关的趋势,为重庆男性的HPV预防和疫苗接种计划提供见解。中国。
    方法:本研究为观察性研究。我们调查了2017年至2022年在重庆两家医院接受HPV筛查的男性患者,共计4381例。18至85岁。使用Hybribio快速基因芯片试剂盒进行HPV基因分型。
    结果:在4,381名男性中,HPV总患病率为14.9%,2022年达到19.3%的峰值。单个HPV感染率为11.5%,多重感染为3.4%。最普遍的基因型是HPV-52、HPV-16和HPV-58。单一高危型HPV感染在36-45岁年龄组达到高峰,而多重高危型HPV感染随年龄增长而减少(P-趋势<0.01)。≤25岁年龄组的患病率为3.7%。单一低危HPV感染也随着年龄的增长而下降(P趋势=0.03)。非单价疫苗覆盖的基因型患病率最高,随着年龄的增长。HPV-16与HPV-52和HPV-58共同感染是常见的。单一HPV感染在尿道炎病例中普遍存在(30.8%),肛门生殖器疣(36.4%),和生殖器疣(26.3%),而多种HPV感染在肛门生殖器疣中显著(18.2%)。
    结论:重庆以单一HPV感染为主,HPV-52,HPV-16,HPV-58,HPV-53和HPV-39是最普遍的基因型。非价疫苗覆盖的基因型的流行率随着年龄的增长而增加。本研究为重庆市制定男性特异性HPV预防策略提供了有价值的见解。
    OBJECTIVE: This study aimed to investigate Human papillomavirus (HPV) infection and genotyping in men from Chongqing and analyze age-related trends to provide insights for HPV prevention and vaccination plans tailored for men in Chongqing, China.
    METHODS: This study is an observational study. We investigated male patients who underwent HPV screening at two hospitals in Chongqing from 2017 to 2022, totaling 4,381 cases, aged 18 to 85. HPV genotyping was conducted using the Hybribio Rapid GenoArray kit.
    RESULTS: Among the 4,381 men, the overall HPV prevalence was 14.9%, peaking at 19.3% in 2022. Single HPV infection was 11.5%, and multiple infection was 3.4%. The most prevalent genotypes were HPV-52, HPV-16, and HPV-58. Single high-risk HPV infection peaked in the 36-45 age group, while multiple high-risk HPV infection decreased with age (P-trend < 0.01). Prevalence in the ≤ 25 age group was 3.7%. Single low-risk HPV infection also decreased with age (P-trend = 0.03). Genotypes covered by the nonavalent vaccine had the highest prevalence, increasing with age. Co-infection of HPV-16 with HPV-52 and HPV-58 was common. Single HPV infections were prevalent in cases of urethritis (30.8%), anogenital warts (36.4%), and genital warts (26.3%), while multiple HPV infections were significant in anogenital warts (18.2%).
    CONCLUSIONS: Single HPV infection was predominant in Chongqing, with HPV-52, HPV-16, HPV-58, HPV-53, and HPV-39 being the most prevalent genotypes. The prevalence of genotypes covered by the nonavalent vaccine increased with age. This study offers valuable insights for developing male-specific HPV prevention strategies in Chongqing.
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  • 文章类型: Journal Article
    背景:中国在结核病(TB)预防和控制方面取得了显著成就,但要实现终结结核病目标仍需要很长的路要走,尤其是在中国西南欠发达地区。结核病医护人员(HCWs)是结核病预防和控制的核心力量,但经常面临职业倦怠。本研究旨在探讨西南地区结核病医务人员职业倦怠的负担及其相关因素。
    方法:这项横断面研究使用了调查问卷和半结构化访谈,基于Malasch模型评估结核病医务人员的职业倦怠,并基于Herzberg的双因素理论(不同的卫生和动机因素)探讨相关因素。定量数据分析采用SPSS22.0中的多元线性回归,定性数据通过框架方法进行分析。
    结果:问卷调查共纳入1140TBHCWs。疾病控制和预防中心(CDC)的TBHCWs的总体工作倦怠率,指定医院和初级卫生保健(PHC)部门占55%,70.1%和67.5%,分别。CDC中人际关系因素得分较低的TBHCWs具有较高的去个性化(DP)风险[B(95CI):-0.89(-1.71至-0.80)]。指定医院的TBHCWs在医患关系因子得分较低[B(95CI):6.63(-12.06至-1.20)]更有可能出现情绪衰竭(EE)。对培训不太满意的TBHCWs,PHC部门的监督和评估[B(95CI):0.65(0.03至1.26)]的个人成就(PA)较少。对9名TBHCWs的访谈表明,环境差可能导致重庆市TBHCWs的高感染率,工作量大可能导致工作压力。还发现,TBHCW的绩效评估和管理,沟通与合作等都与职业倦怠有关。
    结论:TBHCWs在CDC中的工作倦怠程度不同,指定医院,和重庆的PHC部门,受到不同卫生和动机因素的影响。各国政府,组织和个人应采取合作措施,例如加强沟通,以应对结核病HCWs之间的职业倦怠。
    BACKGROUND: China has made remarkable achievements in tuberculosis (TB) prevention and control, but it still takes long way to achieve the End TB goal especially in underdeveloped Southwest China. TB healthcare workers (HCWs) are core forces in TB prevention and control but often face job burnout. This study aimed to explore the burden and associated factors of job burnout among TB HCWs in Southwest China.
    METHODS: This cross-sectional study used both survey questionnaires and semi-structured interviews, to assess job burnout among TB HCWs based on Malasch Model and explore the associated factors based on Herzberg\'s two-factor theory (different hygiene and motivation factors). Quantitative data analysis adopts multiple linear regression to in SPSS 22.0, and qualitative data were analyzed through a framework approach.
    RESULTS: A total of 1140 TB HCWs were included in questionnaire surveys. The overall job burnout rates of TB HCWs in Centers for Disease Control and Prevention (CDC), designated hospitals and Primary Health Care (PHC) sectors were 55%, 70.1% and 67.5%, respectively. TB HCWs in CDC who scored lower in interpersonal factors had a higher risk of depersonalization (DP) [B(95%CI): -0.89 (-1.71 to -0.80)]. TB HCWs in designated hospitals who scored lower in doctor-patient relationship factors [B (95%CI): 6.63 (-12.06 to -1.20)] were more likely to have emotional exhaustion (EE). TB HCWs who were less satisfied with training, supervision and assessment in PHC sectors [B(95%CI): 0.65 (0.03 to 1.26)] had less personal accomplishment (PA). Interviews with nine TB HCWs showed that poor environment could lead to high infection and heavy workload could lead to work pressure among TB HCWs in Chongqing. It is also found that performance assessment and management of TB HCWs, communication and cooperation and so on are related to job burnout.
    CONCLUSIONS: TB HCWs had different levels of job burnout in CDC, designated hospitals, and PHC sectors of Chongqing, which were affected by different hygiene and motivation factors. Governments, organizations and individuals should take cooperative measures such as strengthening communication to deal with job burnout among TB HCWs.
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  • 文章类型: Journal Article
    目的:前瞻性研究健康生活方式因素与卒中风险和卒中亚型之间的关系。因为探索这种关系的研究在中国是有限的。
    方法:重庆市前瞻性队列研究的22,661名参与者,中国,年龄30~79岁,基线时无卒中患者完成了2018~2022年的随访.我们纳入了七个健康的生活方式因素,包括禁烟,不过量饮酒,足够的体力活动,健康饮食,睡眠时间7-9小时/天,以及体重指数和腰臀比的标准范围。根据健康生活方式因素的数量计算健康生活方式评分。
    结果:与得分≤2的参与者相比,得分≥6的参与者的总卒中的HR(95%CI)为0.56(0.34,0.92),缺血性卒中为0.53(0.30,0.93)。健康生活方式得分每增加1分,总卒中和缺血性卒中的HR(95%CI)分别为0.86(0.78,0.95)和0.86(0.77,0.96),分别。
    结论:保持多种健康的生活方式因素可显著降低卒中风险。随着健康生活方式因素的增加,卒中风险逐渐降低。我们的发现强调了全面生活方式干预的重要性。
    OBJECTIVE: To prospectively investigate the associations of healthy lifestyle factors on the risk of stroke and stroke subtypes, as studies exploring this relationship are limited in China.
    METHODS: The 22,661 participants in the prospective cohort study in Chongqing, China, aged 30-79 years and stroke-free at baseline completed follow-up from 2018 to 2022. We included seven healthy lifestyle factors, including non-smoking, non-excessive drinking, sufficient physical activity, healthy diet, sleep duration of 7-9 h/d, and standard range of body mass index and waist-to-hip ratio. The healthy lifestyle score was calculated based on the number of healthy lifestyle factors.
    RESULTS: Compared with participants who had scores ≤2, participants with scores ≥6 had an HRs (95 % CIs) of 0.56 (0.34, 0.92) for total stroke and 0.53 (0.30, 0.93) for ischemic stroke. For every 1-point increase in healthy lifestyle scores, the HRs (95 % CIs) for total stroke and ischemic stroke was 0.86 (0.78, 0.95) and 0.86 (0.77, 0.96), respectively.
    CONCLUSIONS: Maintaining multiple healthy lifestyle factors can significantly reduce the risk of stroke. As the number of healthy lifestyle factors increased, the stroke risk gradually decreased. Our findings emphasize the significance of comprehensive lifestyle interventions.
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  • 文章类型: Journal Article
    登革热是一种病毒性疾病,主要由埃及伊蚊和白纹伊蚊传播。随着气候变化和城市化,越来越多的城市化地区正变得适合登革热媒介的生存和繁殖,因此越来越适合在中国传播登革热。重庆,中国西南部的一个大都市,最近受到输入性和本地登革热的影响,2019年经历首次局部疫情。然而,登革热病毒的遗传进化动态以及输入和本地登革热病例的时空模式尚未阐明。因此,这项研究使用2019年和2023年登革热病毒的基因组数据进行了系统发育分析,并对2013年至2022年收集的登革热病例进行了时空分析.我们对E基因的15个核苷酸序列进行了测序。登革热病毒形成单独的簇,与广东省的登革热病毒具有遗传相关性,中国,东南亚国家,包括老挝,泰国,缅甸和柬埔寨。2019年,重庆经历了登革热疫情,报告了168例输入性病例和1243例本地病例,主要在9月和10月。2013-2018年报告的病例很少,由于COVID-19的封锁,从2020年到2022年只有6例进口。我们的发现表明,重庆市的登革热预防应着眼于国内外人口流动,特别是在渝北和万州区,机场和火车站所在的地方,以及8月至10月期间,登革热在流行地区爆发。此外,应实施持续矢量监测,尤其是在8月至10月期间,这将有助于控制伊蚊。本研究对于明确重庆市适宜的登革热防控策略具有重要意义。
    Dengue fever is a viral illness, mainly transmitted by Aedes aegypti and Aedes albopictus. With climate change and urbanisation, more urbanised areas are becoming suitable for the survival and reproduction of dengue vector, consequently are becoming suitable for dengue transmission in China. Chongqing, a metropolis in southwestern China, has recently been hit by imported and local dengue fever, experiencing its first local outbreak in 2019. However, the genetic evolution dynamics of dengue viruses and the spatiotemporal patterns of imported and local dengue cases have not yet been elucidated. Hence, this study implemented phylogenetic analyses using genomic data of dengue viruses in 2019 and 2023 and a spatiotemporal analysis of dengue cases collected from 2013 to 2022. We sequenced a total of 15 nucleotide sequences of E genes. The dengue viruses formed separate clusters and were genetically related to those from Guangdong Province, China, and countries in Southeast Asia, including Laos, Thailand, Myanmar and Cambodia. Chongqing experienced a dengue outbreak in 2019 when 168 imported and 1,243 local cases were reported, mainly in September and October. Few cases were reported in 2013-2018, and only six were imported from 2020 to 2022 due to the COVID-19 lockdowns. Our findings suggest that dengue prevention in Chongqing should focus on domestic and overseas population mobility, especially in the Yubei and Wanzhou districts, where airports and railway stations are located, and the period between August and October when dengue outbreaks occur in endemic regions. Moreover, continuous vector monitoring should be implemented, especially during August-October, which would be useful for controlling the Aedes mosquitoes. This study is significant for defining Chongqing\'s appropriate dengue prevention and control strategies.
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  • 文章类型: Journal Article
    黑碳(BC),作为气溶胶中的关键光吸收成分,对大气辐射平衡产生深远的影响,气候,空气质量和人类健康,等。这也是快速发展的特大城市的长期重点。所以,本研究主要调查重庆市(31,914,300人口)BC的变异特征和潜在原因,这是中国的直辖市之一,作为中国西南地区的重要经济中心。利用MERRA-2再分析数据,我们研究了重庆20年(2002年至2021年)大气BC的长期变化。此外,于2021年3月15日至6月14日在梁平区使用Aethalometer(AE-33)进行BC质量浓度观测,重庆。过去20年的统计分析显示,重庆市的年平均BC浓度为3.42±0.20μg/m3,从2002年到2008年呈增长趋势,随后从2008年到2021年呈下降趋势。月浓度呈“U形”趋势,最低值出现在夏季,最高出现在冬季。由于地形和气象的影响,当地排放主要导致BC污染,其特征是西部高,东部低的空间分布格局。地面观测表明,BC的昼夜变化具有明显的双峰模式,峰值浓度与高交通排放时期一致。BC的变化受气象条件(风,温度,大气边界层)和当地污染源(主要是交通)。此外,极端事件分析表明,局部排放和区域运输(重庆和四川盆地的贡献较高)主要是BC污染的原因。本研究有效地弥补了分析重庆市BC污染分布和来源的不足,为特大城市的大气环境提供有价值的科学见解。
    Black carbon (BC), as a critical light-absorbing constituent within aerosols, exerts profound effects on atmospheric radiation balance, climate, air quality and human health, etc. And it is also a long-standing focus in rapidly developing megacities. So, this study primarily focuses on investigating the variation characteristics and underlying causes of BC in Chongqing (31,914,300 population), which is one of the municipalities directly under the central government of China, serving as a pivotal economic hub in southwest China. Utilizing MERRA-2 reanalysis data, we examined the long-term changes of atmospheric BC over Chongqing 20 years (from 2002 to 2021). Moreover, BC mass concentration observations were conducted using an Aethalometer (AE-33) from March 15 to June 14, 2021 in Liangping District, Chongqing. The statistical analysis over the last 20 years reveals an annual mean BC concentration in Chongqing of 3.42 ± 0.20 μg/m3, exhibiting growth from 2002 to 2008, followed by a decline from 2008 to 2021. Monthly concentration displays a \"U-shaped\" trend, with the lowest values occurring in summer and the highest in winter. Due to topographical and meteorological influences, local emissions primarily contribute to BC pollution, characterized by a spatial distribution pattern of high in the west and low in the east. Ground observation indicates a distinct dual-peaked pattern in the diurnal variation of BC, with peak concentrations aligning with periods of high traffic emissions. The variation in BC is significantly influenced by meteorological conditions (wind, temperature, atmospheric boundary layer) and local pollution sources (predominantly traffic). Furthermore, extreme events analysis suggests that local emissions and regional transport (with higher contributions from Chongqing and the Sichuan Basin) predominantly contributed to BC pollution. This study effectively makes up for the deficiency in analyzing the distribution and sources of BC pollution in Chongqing, providing valuable scientific insights for the atmospheric environment of megacities.
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  • 文章类型: Journal Article
    在具有潜在复杂季节性模式的地区优化季节性流感控制和预防计划。描述性流行病学用于分析流感的病因,和卡方检验用于比较不同流感病毒类型和亚型/谱系之间的流行模式。2010年1月至2019年12月,重庆市共报告63,626例ILI病例,实验室确诊流感病例14,136例(22.22%)。甲型和乙型流感阳性标本比例分别为13.32%(8,478/63,626)和8.86%(5,639/63,626),分别。甲型流感阳性标本的比例在冬季达到最高(23.33%),而乙型流感阳性标本的比例在春季最高(11.88%)。5-14岁儿童的流感阳性标本比例最高。流感病毒类型/亚型阳性的季节和年龄组差异显著(P<.001),但不是按性别(p=.436)。除2018年外,疫苗株与所有其他年份的流行流感病毒株匹配(疫苗株为B/Colorado/06/2017;流行株为B/Yamagata)。研究表明,流行模式存在显著差异,包括季节性流行期和年龄分布,在不同的流感类型中,重庆的亚型/谱系。在10年中的9年中,流感疫苗与流行的流感病毒株相匹配。为了预防和减轻该地区的流感爆发,高危人群,尤其是5-14岁的儿童,鼓励在流行季节之前接种流感疫苗。
    To optimize seasonal influenza control and prevention programs in regions with potentially complicated seasonal patterns. Descriptive epidemiology was used to analyze the etiology of influenza, and chi-square tests were used to compare the epidemic patterns among different influenza virus types and subtypes/lineages. From January 2010 to December 2019, a total of 63,626 ILI cases were reported in Chongqing and 14,136 (22.22%) were laboratory-confirmed influenza cases. The proportions of specimens positive for influenza A and influenza B were 13.32% (8,478/63,626) and 8.86% (5,639/63,626), respectively. The proportion of positive specimens for influenza A reached the highest in winter (23.33%), while the proportion of positive specimens for influenza B reached the highest in spring (11.88%). Children aged 5-14 years old had the highest proportion of positive specimens for influenza. The influenza virus types/subtypes positive was significantly different by seasons and age groups (P<.001), but not by gender (p = .436). The vaccine strains were matched to the circulating influenza virus strains in all other years except for 2018 (vaccine strain was B/Colorado/06/2017; circulating strain was B/Yamagata). The study showed significant variations in epidemic patterns, including seasonal epidemic period and age distributions, among different influenza types, subtypes/lineages in Chongqing. Influenza vaccines matched to the circulating influenza virus strain in nine of the ten years. To prevent and mitigate the influenza outbreaks in this area, high risk population, especially children aged 5-14 years, are encouraged to get vaccinated against influenza before the epidemic seasons.
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  • 文章类型: Journal Article
    背景:青少年中不健康的生活方式已达到惊人的程度,并已成为主要的公共卫生问题。这项研究旨在评估睡眠时间之间的关系,体力活动(PA)时间,屏幕时间(ST),和营养素养(NL)。方法:这项涉及10-18岁青少年的横断面在线研究于2020年9月在重庆市239所学校进行,中国。使用“重庆市中学生营养素养量表(CM-NLS)”测量NL。根据中国膳食指南(2022)的建议,我们将初中生的睡眠时间分为<9h和≥9h,高中生进入<8小时和≥8小时,将工作日分为周末PA时间<1小时和≥1小时,并将工作日分为周末ST<2h和≥2h。使用多项逻辑回归模型来检验相关性。结果:共纳入18,660名青少年(50.2%为男性)。初中生和寄宿学校的参与者比例分别为57.2%和65.3%,分别。与高中生相比,初中生的NL水平较高。无论是工作日还是周末,睡眠时间≥8/9小时的参与者,PA时间≥1h,和ST<2小时每天有较高的NL水平。在工作日,睡眠时间≥8h/9h(OR=1.48,95%CI:1.36,1.62)和PA时间≥1h(OR=1.69,95%CI:1.59,1.81)的参与者NL水平报告较高.结论:睡眠时间,PA时间,ST与青少年NL呈正相关,尤其是初中生。
    Background: Unhealthy lifestyles among adolescents are reaching alarming levels and have become a major public health problem. This study aimed to assess the relationship between sleep time, physical activity (PA) time, screen time (ST), and nutritional literacy (NL). Methods: This cross-sectional online study involving adolescents aged 10-18 years was conducted in September 2020 in 239 schools in Chongqing, China. NL was measured using the \"Nutrition Literacy Scale for middle school students in Chongqing (CM-NLS)\". According to the recommended by the Chinese dietary guidelines (2022), we divided the sleep time of junior high school students into <9 h and ≥9 h, high school students into <8 h and ≥8 h, divided the workdays into weekend PA time < 1 h and ≥1 h, and divided the workdays into weekend ST < 2 h and ≥2 h. The multinomial logistic regression model was used to examine the association. Results: A total of 18,660 adolescents (50.2% males) were included. The proportion of participants that were junior high school students and attended boarding schools was 57.2% and 65.3%, respectively. Compared with senior high school students, junior high school students had a higher level of NL. Whether on workdays or weekends, participants with sleep time ≥ 8/9 h, PA time ≥ 1 h, and ST < 2 h per day had higher levels of NL. On weekdays, participants who met the sleep time ≥ 8 h/9 h (OR = 1.48, 95% CI: 1.36, 1.62) and PA time ≥ 1 h (OR = 1.69, 95% CI: 1.59, 1.81) had higher reporting of NL levels. Conclusions: Sleep time, PA time, and ST were positively correlated with NL among adolescents, especially junior high school students.
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  • 文章类型: Journal Article
    目的:了解重庆市未接种疫苗的无偿献血者中严重急性呼吸综合征冠状病毒2(SARS-CoV-2)抗体的发生率,并为疫情监测提供证据。
    方法:收集重庆地区2021年1月5日至1月20日无偿献血者10208人,用化学发光法检测SARS-CoV-2免疫球蛋白(Ig)G和IgM抗体,不同性别抗体阳性率的差异,年龄,ABO血型,并对不同的风险区域进行了分析。
    结果:在10208名献血者中,发现10例SARS-COV-2IgG抗体阳性,SARS-COV-2IgG阳性率为0.10%,29例SARS-CoV-2IgM抗体阳性,SARS-CoV-2IgM阳性率为0.28%。不同性别间抗体阳性率无统计学差异,年龄,和ABO血型,但这与每个城市2019年确诊的冠状病毒病(COVID-19)病例数有关。
    结论:重庆市SARS-CoV-2血清阳性率较低,且与COVID-19确诊病例数相关。
    OBJECTIVE: To investigate the rate of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody among unvaccinated voluntary blood donors in Chongqing, and to provide evidence for epidemic surveillance.
    METHODS: A total of 10,208 voluntary blood donors from January 5 to January 20, 2021, in the Chongqing area were collected, and the SARS-CoV-2 immunoglobulin (Ig) G and IgM antibodies were detected by chemiluminescence, and the differences of antibody-positive rate in different gender, age, ABO blood group, and different risk areas were analyzed.
    RESULTS: Among 10208 blood donors, 10 were found to be positive for SARS-COV-2 IgG antibody, giving a positivity rate of SARS-COV-2 IgG at 0.10%, and 29 were positive for SARS-CoV-2 IgM antibody, with a positivity rate of SARS-CoV-2 IgM at 0.28%. There was no statistical difference in the positive rate of antibody among different genders, ages, and ABO blood types, but it was related to the number of confirmed coronavirus disease 2019 (COVID-19) cases in each city.
    CONCLUSIONS: The SARS-CoV-2 seroprevalence rate in Chongqing was low and correlated with the number of confirmed COVID-19 cases.
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  • 文章类型: Journal Article
    绿地绿地比率(GPR)的量化主要基于估算公式,这些估算公式中的叶面积指数(LAI)估算值没有得到很好的验证,导致探地雷达定量结果存在误差和不确定性。本研究旨在通过测量重庆113个区域植物的LAI来解决这一差距,中国,遵循数字半球摄影(DHP)的标准化测量路径。结果表明,在阴天条件下,最佳相对暴露值(REV)为-1,在晴天和多云条件下为-2。在半球形图像的阈值算法中,ImageJ中的Intermodes算法是最好的。区域植物的LAI在夏季最高,接下来是春天和秋天,冬天最低。树高(h)和树冠宽度(w)是影响LAI的关键因素,但是LAI也因植物种类而异。总的来说,常绿乔木的LAI高于落叶乔木。高度小于5m的常绿乔木和灌木的LAI最大,树冠宽度大于8m的落叶乔木和灌木最大。研究进一步验证了现有的探地雷达估算公式在重庆表现出较大的误差,而GPR估计值与测量值之间存在很强的相关性(R2=0.973)。开发了一个转换公式来减少估计偏差,并且校正的公式能够在实际LAI测量不足时更准确地估计GPR值。总的来说,这项研究验证了测量局部LAI值的重要性,促进了LAI对GPR计算的适用性的理解,并为重庆的探地雷达估算提供了经验公式,中国。
    The quantification of green space green plot ratio (GPR) is mostly based on estimation formulas, and the leaf area index (LAI) estimation values in these estimation formulas have not been well verified by measured LAI values, resulting in errors and uncertainties in GPR quantification results. This study aims to address this gap by measuring the LAI of 113 regional plants in Chongqing, China, following a standardized measurement path for digital hemispherical photography (DHP). The results indicate that the optimal relative exposure value (REV) was - 1 under overcast conditions and - 2 under sunny and cloudy conditions. Among the threshold algorithms for hemispherical images, the Intermodes algorithm in ImageJ was the best. The LAI of regional plants is highest in summer, followed by spring and autumn, and lowest in winter. Tree height (h) and crown width (w) are key factors affecting LAI, but the LAI also varies with plant species. Overall, the LAI of evergreen trees is higher than that of deciduous trees. The LAI of evergreen trees and shrubs with a height shorter than 5 m is the largest, and that of deciduous trees and shrubs with a crown width larger than 8 m is the largest. The study further verified that the existing GPR estimation formula exhibited large errors in Chongqing, while there was a strong correlation (R2 = 0.973) between the GPR estimation value and the measured value. A conversion formula was developed to reduce estimation biases, and the corrected formula is capable of estimating GPR values more accurately when actual LAI measurements are insufficient. Overall, this study verifies the significance of measuring localized LAI values, promotes the understanding of LAI suitability for GPR calculations, and provides an empirical formula for GPR estimation in Chongqing, China.
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  • 文章类型: English Abstract
    分析重庆市农产品主产区农业土壤重金属的来源解析及健康风险,采用基于蒙特卡罗模拟的正矩阵分解(PMF)模型和健康风险评估(HRA)模型。同时,将PMF和HRA模型相结合,探讨不同污染源对农业土壤重金属的健康风险,以确定优先控制因子。结果表明,Cd浓度的平均值高于其对应的背景值;Cr浓度的平均值低于其对应的背景值;As,Pb,Cu,Ni,Zn浓度与相应背景值基本一致。使用PMF模型分析,自然来源,工业来源,农业来源被确定为农业土壤中重金属积累的决定因素,贡献率为35%,24%,41%,分别。利用基于蒙特卡罗模拟分析的HRA模型,成人和儿童的致癌风险是可以容忍的(1.00E-6<TCR≤1.00E-4),而非致癌风险是可以接受的(HI≤1)。口服是主要的暴露途径。重金属之间关系的分析结果,污染源,和健康风险表明,工业污染和砷被确定为优先控制因素,农业污染和Cd被确定为二级控制因子。我们的研究结果为决策者控制土壤污染和降低土壤污染的管理成本提供了科学支持。
    To analyze the source apportionment and health risk of heavy metals in agricultural soils of major producing areas of agricultural products in Chongqing, a positive matrix factorization (PMF) model and health risk assessment (HRA) model based on Monte Carlo simulation were used. Meanwhile, both the PMF and HRA model were combined to explore health risks of heavy metals in agricultural soils by different pollution sources in order to determine the priority control factors. The results showed that the average values of Cd concentration were higher than its corresponding background value; the average values of Cr concentration were lower than its corresponding background value; and the average values of As, Pb, Cu, Ni, and Zn concentration were basically consistent with their corresponding background values. Using PMF model analysis, natural sources, industrial sources, and agricultural sources were identified as the determinants for the accumulation of heavy metals in agricultural soils, with the contribution rates of 35%, 24%, and 41%, respectively. Using the HRA model based on Monte Carlo simulation analysis, carcinogenic risks of adult and children were tolerable (1.00E-6 < TCR ≤ 1.00E-4), whereas non-carcinogenic risks were acceptable (HI ≤ 1). Oral ingestion was the main exposure pathway. The analysis results of the relationship among heavy metals, pollution sources, and health risks showed that industrial pollution and As were identified as priority control factors, and agricultural pollution and Cd were identified as secondary control factors. Our findings provide scientific support for decision makers to control soil pollution and reduce the management costs of soil pollution.
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