Background Brucellosis, a zoonotic disease caused by Brucella species, poses a significant public health concern in China, particularly in pastoral and areas. The incidence of human brucellosis has risen sharply in China but little is known about trends in pastoral and agricultural areas respectively. Methods Annual and monthly incidence and numbers of reported cases of human brucellosis in regional China between 2004 and 2019 were accessed from the National Public Health Science Data Sharing Center, and the annual percentage change (APC) in pastoral and agricultural areas was calculated. Annual and monthly trends were analyzed by the Joinpoint regression model. Results 569016 cases of human brucellosis were reported between 2004 and 2019 with a peak in 2014. A trend of increasing incidence was found (AAPC = 6.3%, 95% CI: 3.2–9.4%) with higher rates in pastoral areas but greater mean increases in agricultural (AAPC = 9.4) and agricultural/pastoral areas (AAPC = 7.7) than in pastoral areas (AAPC = 5.9). Infections occurred throughout the year with a concentration of cases between March and July. Increasing monthly incidence was found in all types of areas from January to May (APC > 0) and a decreasing monthly trend was seen from May to December (APC < 0, p < 0.05). Conclusions The incidence of human brucellosis was higher in pastoral areas of China than in agricultural/pastoral or agricultural areas, however, the rate of increase was higher in agricultural/pastoral and agricultural areas than in pastoral areas. Epidemic surveillance should be strengthened in key counties (cities, districts) and prevention and control measures increased nationwide.

This study examines the association between functional disability and depressive symptoms among Chinese centenarians, and the mediating role of leisure activities and attitudes toward aging in this association. The data were obtained from a cross-sectional household survey of 185 centenarians in Nanjing. We used Ordinary least squares (OLS) and structural equation modeling (SEM) to examine the associations between functional disability, leisure activities, attitudes toward aging, and depressive symptoms. Functional disability was positively associated with depressive symptoms (b = 0.24, p < 0.001). Both leisure activities (34.2

Energy interconnection is an important part of the Belt and Road Initiative,and ensuring the safety of energy transportation pipelines is of great significance in promoting the high-quality development of the Belt and Road Initiative.This paper takes China's cross-border oil and gas transport pipelines as the research object,and constructs an oil and gas transport pipeline safety evaluation index system covering five dimensions of pipeline,resources,economy,politics and diplomacy from two aspects of pipeline safety and pipeline routing involving national security.Based on the entropy-catastrophe progression method,the safety of China's cross-border oil and gas transport pipelines in 2020 is evaluated and classified into categories.The results show that:(1)The catastrophe level values of crude oil transportation pipelines are ranked as China-Kazakhstan crude oil pipeline＞China-Russia crude oil pipeline＞China-Myanmar crude oil pipeline;the catastrophe level values of natural gas transportation pipelines are ranked as China-Central Asia natural gas pipeline line C＞China-Central Asia natural gas pipeline lines A and B＞east route of China-Russia natural gas pipeline＞China-Myanmar natural gas pipeline;and the pipelines have their respective advantages and disadvantages under the sub-dimensions.(2)According to the system clustering method,the pipelines are divided into two types:high security type and low security type.The high safety pipelines are in good condition at present,but there are still safety hazards;resource scarcity,political instability,and economic weakness have become unfavourable factors affecting the safety evaluation of low safety pipelines.

百岁老人作为老年人口中最脆弱的社会群体,其生活质量的改善对于实现"健康老龄化"与"和谐社会"具有重要的现实意义.本文基于"美好生活"理论框架,从4 个维度(躯体健康、心理健康、家庭社会支持、社会经济地位)构建了百岁老人生活质量概念框架;结合探索性因子分析法对百岁老人生活质量的潜在结构进行探究,进而开展全面评价.结果表明:(1)南京市百岁老人生活质量处于中等水平,生活质量主要由躯体健康、心理支持、社会经济地位和感官能力4 个维度构成.(2)百岁老人心理支持处于中等偏高水平,社会经济地位、躯体健康和感官能力处于中等偏低水平.(3)不同社会经济属性的百岁老人生活质量差异显著.本文为深入了解百岁老人生活质量提供较好的实证案例,同时为"健康老龄化"政策选择提供理论依据.

With the continuous expansion of the scope and scale of liquefied natural gas (LNG) trade, global LNG import competition has become increasingly extensive and complex. However, there is currently a lack of research on the global LNG import competition pattern and its influence mechanism. This study first constructs a global LNG import competition network and uses the complex network method to analyse the global LNG import competition pattern and its evolution characteristics from 2000 to 2020. Then, an extended gravity model is established to explore the factors influencing the intensity of LNG import competition. The results show that the global LNG import competition becomes increasingly widespread and intense; the intensity of global LNG import competition is unevenly distributed and concentrated within Asia, within Europe, between Asia and Europe, and among a few large importers; large importers dominate the formation and evolution of the competition pattern; the position of Asian countries in the competition pattern has gradually improved, and the positions of European and American countries in the competition pattern have gradually declined, indicating that the centre of the competition pattern has gradually shifted to Asia; Japan has the most intense competition, but its position in the competition pattern has declined; and China has increasingly intense competition with other importers, and its position in the competition pattern has become increasingly important; The GDP and natural gas consumption of importers drive the competition intensity among importers, while the natural gas production, political risk, and technology level of importers and the distance between importers impede the competition intensity among importers. Finally, some policy recommendations are proposed to promote orderly and healthy competition in LNG.

石油空间流动的现有研究,主要是对国家(地区)层面的贸易网络和供应链时空演化特征的分析,缺乏对不同行为体之间的石油权力博弈过程及其战略耦合关系的系统分析.因此,运用全球生产网络理论,分析1999年和2021年两个时点下的金陵石化原油和成品油生产网络特征及其战略耦合变动.研究发现:(1)金陵石化原油生产网络由国内原油为主转变为进口中东原油为主,主要通过长期协议现货原油贸易;(2)金陵石化成品油生产网络的经销对象呈"多元化"趋势,且政府对其具有较强的调节作用;(3)金陵石化原油生产网络的战略耦合,由内部耦合为主转变为交互耦合为主;(4)金陵石化成品油生产网络的战略耦合,一直以内部耦合为主,但其内部耦合的主导地位弱化.

This study aimed to examine the association between tooth loss and frailty among Chinese older adults and the mediating role of dietary diversity in this association. Data from five waves of the Chinese Longitudinal Healthy Longevity Survey conducted between 2005 and 2018 were used. Path analyses were employed to assess both concurrent and cross-lagged relationships between tooth loss and frailty index while accounting for intrapersonal correlation. Furthermore, the mediation effect of dietary diversity was also examined. In concurrent models, severe tooth loss was associated with frailty after adjusting for demographic characteristics (odds ratio [OR] = 1.82, p < 0.001). The OR of frailty for severe tooth loss was only slightly decreased to 1.74 (p < 0.001) when dietary diversity was added to the model and to 1.64 (p < 0.001) when socioeconomic status, family support, and healthy lifestyles were further adjusted. In the cross-lag or longitudinal models, the ORs were mildly or moderately reduced to 1.29, 1.27, and 1.23, respectively, yet remained statistically significant (p < 0.001 or p < 0.01). The mediation analyses showed that dietary diversity had some small yet significant effects on the relationship between tooth loss and frailty in both concurrent and longitudinal settings. This study improves current knowledge regarding the impact of tooth loss on frailty among Chinese older adults. Future intervention strategies designed to improve healthy diets may have preventive effects against the risk of frailty among Chinese older adults with severe tooth loss.

能源合作是共建"一带一路"的重点领域.开展"一带一路"沿线国家石油产品贸易网络演化研究有助于加强沿线国家在石油产品贸易上的合作.以石油产品为研究对象,运用复杂网络分析21世纪以来"一带一路"沿线国家石油产品贸易网络的动态演化,并揭示其与原油贸易网络的异同.研究发现:(1)石油产品贸易网络是"核心-边缘"式的小世界网络,呈现规模扩大、紧密性提升、结构日趋复杂的特征,且这些特征比原油贸易网络更显著;(2)石油产品贸易空间不均衡性显著,呈现出新加坡、俄罗斯、沙特阿拉伯等枢纽节点辐射,新加坡、中国、马来西亚等枢纽节点辐合为主的空间形态,枢纽节点地位日益强化;(3)石油产品贸易网络社团逐步聚拢,演化成以俄罗斯、新加坡和中东国家为核心的三大稳定社团,中国逐步"脱俄入新".最后,根据研究结论提出了相应的政策建议和启示.

China is facing an increasingly contradictory challenge between growing demand for health services for the oldest-old and the unbalanced and inadequate development in the context of rapid population aging. This study sought to evaluate the quality of life of the oldest-old in China under the active aging framework. Health, participation, and security data were sourced from China Statistics/Labor Statistics/Civil Affairs Yearbook 2000-2016 and National 1% Sample Survey Data 2005-2015. Then, we used the current life table, entropy method, coefficient variation, and panel data regression to evaluate the quality of life among the oldest-old and reveal its regional differences and mechanisms. The results show: (1) From 2005 to 2015, the overall quality of life in China steadily improved, and the quality of health, participation, and security of the oldest-old increased by 6.06%, 5.64%, and 47.48%, respectively. (2) Distinct regional disparities exist in the distribution of quality of life for the oldest-old in China; the "east-northeast-middle-west" stepped-declining pattern existed stably. (3) Population and family structure, economic development, and social security were the main reasons for the regional differences in quality of life for the oldest-old. Narrowing the socioeconomic gap between regions, promoting the function of family pension, and improving social old-age service supply will help improve the quality of life of the oldest-old.

Excessive fat deposition in the tail of sheep will affect its feed efficiency, which will increase the feeding cost. The purpose of this study was to identify the single nucleotide polymorphisms (SNPs) of RAP1GAP and rBAT genes by PCR amplification and Sanger sequencing, the SNPs were genotyped by KASP genotyping assays to evaluate their association with tail fat deposition traits. The results showed that two intronic mutations of g.13561 G > A and g.1460 T > C were found in RAP1GAP and rBAT, respectively. There were three genotypes of GG, AG, AA and CC, CT and TT at these two loci, respectively. Association analysis showed that g.13561 G > A of RAP1GAP was associated with tail width, tail fat weight and relative tail fat weight (P < 0.05). The g.1460 T > C of rBAT was associated with tail width and tail fat weight (P < 0.05). Different combinations of genotypes also differed significantly with tail fat deposition traits. In the tail fat tissue, the expression levels of RAP1GAP gene was significantly higher in small-tailed sheep than in big-tailed sheep, and the expression levels of rBAT gene was significantly higher in big-tailed sheep than in small-tailed sheep. In the liver, the expression levels of RAP1GAP and rBAT gene was significantly higher at 6 months than at 0 and 3 months. In conclusion, RAP1GAP and rBAT polymorphisms can be used as a candidate molecular marker to reduce tail fat deposition in sheep.

实施乡村振兴战略是决胜全面建成小康社会、全面建设社会主义现代化强国的重大历史任务.乡村振兴与地理学科联系紧密,中学地理教学应及时把握学科动向,将乡村振兴内容有机渗透于教学中.采用内容分析法,以高中必修课程"地理2"的相关内容和人教版教材为载体,对教学中可渗透乡村振兴的内容进行系统梳理,并提出了相应的教学建议.

稀土是一个国家经济社会发展极其重要的战略资源，从长时间尺度分析其进口竞争格局并预测未来潜在的贸易联系可为稀土进出口国制定和调整稀土贸易政策提供参考。以稀土（HS:280530）为研究对象，运用复杂网络方法，构建1990—2018年全球稀土进口竞争网络，分析全球稀土进口竞争格局、演变特征，大洲、国家间竞争特点以及对中国稀土的竞争状况。然后，使用基于局部信息相似性的链路预测算法，揭示稀土贸易联系动机，预测潜在贸易联系。结果显示：（1）全球稀土进口竞争网络规模有所扩大，竞争的全球化程度有所提高且呈现“紧密性”；（2）大洲间竞争关系及强度主要分布在欧洲内部、亚洲内部以及欧洲与亚洲之间，国家间竞争强度高度集中于少数竞争关系；稀土进口大国之间的竞争是全球稀土进口竞争格局的最重要组成部分，主导着竞争格局的形成演化；日本与其他稀土进口国竞争最为激烈；（3）受中国稀土生产出口政策等因素影响，稀土进口国竞争全球和中国稀土由“日趋激烈”向“总体和缓”转变；竞争强度高度集中于中国，稀土进口国竞争中国稀土最为激烈；（4）优先链接是稀土进出口国的结构性贸易联系动机。未来，美国与比利时、日本与德国等国家之间建立稀土贸易联系的可能性大，瑞典等国可能与中国建立稀土贸易联系。

Rumen microbes play an important role in the growth and development of ruminants. Differences in variety will affect the rumen community structure. The three excellent sheep breeds were selected for this study (Hu sheep, Tan sheep, and Dorper sheep) have different uses and origins. The sheep were raised on the same diet to 180 d of age in a consistent environment. 16S rDNA V3 to V4 region sequencing was used to assess the rumen microbes of 180 individuals (60 per breed). There were differences in microbial diversity among different sheep breeds (P < 0.05). Principal coordinate analysis showed that the three varieties were separated, but also partially overlapped. Linear discriminant analysis effect size identified a total of 19 biomarkers in three breeds. Of these biomarkers, five in Hu sheep were significantly negatively correlated with average feed conversion rate (P < 0.05). Six biomarkers were identified in the rumen of Dorper sheep, among which Ruminococcus was significantly positively correlated with body weight at 80 d (P < 0.05). In Tan sheep, Rikenellaceae_RC9_gut_group was significantly positively correlated with meat fat, and significantly positively correlated with volatile fatty acids (VFAs), such as butyric acid and isobutyric acid (P < 0.05). The Rikenellaceae_RC9_gut_group may regulate Tan mutton fat deposition by affecting the concentration of VFAs. Functional prediction revealed enrichment differences of functional pathways among different sheep breeds were small. All were enriched in functions, such as fermentation and chemoheterotrophy. The results show that there are differences in the rumen microorganisms of the different sheep breeds, and that the microorganisms influence the host.

基于中国297个地级及以上城市在营家政服务企业、家政服务网络关注度等数据,构建家政服务业发展与需求评价指标体系,采用均方差决策法、耦合协调度模型和空间自相关等方法,分析中国城市家政服务业发展与需求空间分异特征及耦合协调程度.结果表明:1)中国城市家政服务业发展水平总体偏低,区域差异较大,"东—中—西"阶梯式递减态势凸显,呈现出城市群核心城市突出的点状格局;家政服务业需求程度区域差异相对较小,存在明显的空间集聚现象,形成长三角、环渤海、珠三角、海峡西岸四大高值集聚区.2)中国城市家政服务业发展与需求耦合协调度整体处于中度协调水平,东西方向空间分异最为明显,形成城市群核心—外围和省区中心—边缘的典型集聚区.3)伴随城市等级的下降,耦合协调度等级从极度协调转向低度协调,家政服务业发展滞后型城市占比逐渐增大,企业数量较低、质量和规模程度更低是导致耦合协调度较低的主要原因.最后基于耦合协调度类型提出具体对策建议,为实现家政服务供需的更高水平动态平衡提供理论依据.

The increasing dependence on foreign natural gas has brought severe challenges to China's natural gas supply security. Hence, choosing secure and reliable natural gas suppliers is crucial. This paper first proposes a comprehensive evaluation framework for the natural gas supply security of natural gas suppliers from two aspects: suppliers' own factors and the interaction factors between importers and suppliers based on the risk factors of the natural gas supply chain. On this basis, the PROOTHEE model based on the combination weight method is introduced to measure the supply security performance of China's 15 natural gas suppliers from 2015 to 2019. The results show that the supply security performance of China's natural gas suppliers varies greatly and the gap widened. Australia, Russia and the United States are the top three countries in terms of the overall supply security. Qatar, Norway, Turkmenistan, Kazakhstan, Malaysia and Uzbekistan show moderate supply security. Oman, Papua New Guinea, Trinidad and Tobago and Nigeria demonstrate poor supply security. Most suppliers have medium and low supply security and China's natural gas imports from suppliers do not match their supply security levels to some extent, which results in China's natural gas imports facing a relatively high supply risk. Considering risk controllability, China should focus more on interaction factors, especially to strengthen energy diplomacy.

基于"天眼查"网络大数据,本文以江苏省13个地级市为研究单元,采用马尔科夫链等方法,分析江苏省家政服务业发展历程及现状问题,提出对策建议.研究发现,2000—2020年江苏省家政服务企业数量不断增长,分为快速、稳步、迅猛三个发展阶段.苏南地区发展水平较高,苏中、苏北地区多数城市发展水平较低;各城市家政服务业发展具有较强的稳定性,存在一定程度的"俱乐部趋同"现象.2020年在营家政服务企业中有90.79％为综合服务型,部分企业开始提供专业化服务.家政服务企业类型以个体户和有限责任公司为主,注册资本偏低.最后提出规范市场准入机制、培育龙头企业、以信用和标准为引领、促进城市间的交流与合作等建议,以期为江苏省家政服务业高质量发展提供依据.

基于百度指数采集到的家政服务需求数据,整合地区、城市群、城市等多种尺度,对2012-2018年中国285个地级及以上城市家政服务需求的时空演变特征进行测度,并采用多元线性回归模型定量探测其影响机制.结果 表明:①2012-2018年中国城市家政服务需求逐年上升,区域差异缩小,可分为"迅猛增长""高位稳定"两个阶段.同时,家政服务需求以低、中低类型为主,以中心城市为核心,呈现出明显的"核心—外围"特征.②中国城市家政服务需求呈"东—中—西"阶梯式递减态势,地区内差异始终大于地区间差异.不同类型城市群具有"国家级＞区域级＞地区级＞城市群外"倒金字塔式集群增长特征,形成了"一线＞新一线＞二线＞三线＞四线＞五线城市"的等级结构.③供给、需求条件共同影响家政服务需求.经济发展水平和产业结构影响家政服务的供给规模和质量,人口规模、居民消费与收入水平影响家政服务需求规模和居民支付能力.最后对如何提升家政服务等改善型消费需求、扩大内需进行了讨论,以期为促进家政服务业提质扩容和实施扩大内需战略提供理论依据和实践参考.

准确把握地理教材中核心概念的内容表述,对于地理的教与学至关重要."城乡内部空间结构"是新课标的新增内容,四版本教材对其的处理不尽相同.本文在研读课标内容要求及四版本教材关于"城乡内部空间结构"内容表述的基础上,分析"城镇内部空间结构"相关概念的演变历程、总结提炼概念的界定维度与内容表述特征,为教材新增的"乡村内部空间结构"提供分析框架,以期帮助广大教师更好地理解和把握"城乡内部空间结构"的内容特征,指导教学.

The role of health behaviors in oral health conditions in individuals of extremely old age remains understudied. This study included 185 participants aged 100 years or older from the Nanjing Centenarians Study (NCS) to examine the associations between health behaviors and oral health and investigate the potential moderating role of education and living arrangements in such relationships. The oral health status as an outcome included the self-reported oral health status and edentulous status. Health behavior variables included smoking, eating fruits, eating vegetables, participating in leisure activities, and practicing oral hygiene behaviors. Sociodemographic characteristics and health status were considered as confounders. Descriptive statistics, ordinal regression, and logistic regression models were used to address the research questions. Results showed that better oral health was reported by centenarians who were non-smokers, participated in more leisure activities, and practiced higher frequency of oral hygiene behaviors. Those who ate fruits daily and practiced more frequently oral hygiene behaviors were more likely to be dentate. The positive association of oral hygiene behaviors was stronger for centenarians who were formally educated and co-resided with family members. The results suggest that effective interventions should consider health behaviors and living arrangements in this growing population to improve their oral health status.

基于百度指数获取2014-2018年中国大陆31个省份对俄罗斯旅游相关关键词的网络关注度数据,采用基尼系数、首位度、季节性集中指数、地理探测器等方法,分析中国赴俄网络关注度的时空差异及其影响因素.结果 表明:1)2014-2018年网络关注度与实际赴俄游客数呈正相关,5年间网络关注度增长迅猛,各月关注度则愈发均衡.2)网络关注度呈现东高西低、南高北低的特征,而网络关注度的季节性集中指数则相反;各省份网络关注度由极化分布转为相对均衡分布;各省份网络关注度的首位度不显著,北方地区最高.3)各省份网络关注度等级变化不大,东西部省份差异明显.高关注地区始终为广东、北京、上海、江苏、浙江,低关注地区以西部为主,形成甘肃-宁夏-青海-西藏连片分布的格局.4)经济发展水平、互联网普及度、国内旅游开放度是影响网络关注度空间分异的核心因素,城镇人口比重、赴俄交通便利程度、客源地夏季平均气温也起到重要作用.最后从加大互联网营销力度、推动开通直飞俄罗斯航线、开发个性化多元化旅游产品等方面提出对策建议,以期为中国赴俄旅游更好更快发展提供理论指导与实践启示.