12 research outputs found

    Modelling the geographical spread of HIV among MSM in Guangdong, China: a metapopulation model considering the impact of pre-exposure prophylaxis

    Get PDF
    Men who have sex with men (MSM) make up the majority of new human immunodeficiency virus (HIV) diagnoses among young people in China. Understanding HIV transmission dynamics among the MSM population is, therefore, crucial for the control and prevention of HIV infections, especially for some newly reported genotypes of HIV. This study presents a metapopulation model considering the impact of pre-exposure prophylaxis (PrEP) to investigate the geographical spread of a hypothetically new genotype of HIV among MSM in Guangdong, China. We use multiple data sources to construct this model to characterize the behavioural dynamics underlying the spread of HIV within and between 21 prefecture-level cities (i.e. Guangzhou, Shenzhen, Foshan, etc.) in Guangdong province: the online social network via a gay social networking app, the offline human mobility network via the Baidu mobility website, and self-reported sexual behaviours among MSM. Results show that PrEP initiation exponentially delays the occurrence of the virus for the rest of the cities transmitted from the initial outbreak city; hubs on the movement network, such as Guangzhou, Shenzhen, and Foshan are at a higher risk of 'earliest' exposure to the new HIV genotype; most cities acquire the virus directly from the initial outbreak city while others acquire the virus from cities that are not initial outbreak locations and have relatively high betweenness centralities, such as Guangzhou, Shenzhen and Shantou. This study provides insights in predicting the geographical spread of a new genotype of HIV among an MSM population from different regions and assessing the importance of prefecture-level cities in the control and prevention of HIV in Guangdong province. This article is part of the theme issue 'Data science approach to infectious disease surveillance'

    An Empirical Study on Spatial–Temporal Dynamics and Influencing Factors of Tea Production in China

    No full text
    Revealing the characteristics of spatial–temporal dynamics and influencing factors is important for optimizing the spatial distribution of tea production. Taking prefecture-level cities as the basic spatial unit, this study uses the Herfindahl index and exploratory spatial data analysis to reveal the spatial–temporal dynamics of China’s tea production from 2000 to 2015. A theoretical analysis framework is established and a spatial econometric model is used to explore its influencing factors. The results show a U-shaped trend in the degree of tea spatial agglomeration, which gradually declined during 2000–2010, and rapidly increased during 2011–2015. The proportion of tea production shifted from the eastern region to the central and western regions, and spatial distribution coverage expanded to the north. Tea production had significant spatial correlation, and spatial agglomeration characteristics were exhibited for similar values (high or low). Tea production had a significant spatial spillover effect. Natural resources, labor cost, specialized production, and policies all affected the spatial–temporal dynamics of tea production somewhat, but the effects of traffic conditions and technological level were insignificant. Finally, this study proposed optimizing four aspects of the tea spatial layout: regional cooperation, comprehensive suitability evaluation of tea cultivation, spatial agglomeration, and distinctive local brands

    Severity of passenger injuries on public buses: A comparative analysis of collision injuries and non-collision injuries

    No full text
    Introduction: Although public buses have been demonstrated as a relatively safe mode of transport, the number of injuries to public bus passengers is far from negligible. Existing studies of public bus safety have focused primarily on injuries caused by collisions. Surprisingly, limited effort has been devoted to identifying factors that increase the severity of passenger injuries in non-collision incidents. Method: Our study therefore investigated the injury risk of public bus passengers involved in collision incidents and non-collision incidents comparatively, based on a police-reported dataset of 17,383 passengers injured on franchised public buses over a 10-year period in Hong Kong. A random parameters logistic model was established to estimate the likelihood of fatal and severe injuries to passengers as a function of various factors. Results: Our results indicated substantial inconsistences in the effects of risk factors between models of non-collision injuries and collision injuries. The severity of passenger injuries tended to increase significantly when non-collision incidents occurred due to excessive speed of bus drivers, on double-decker buses, in less urbanized areas, in winter, in heavy rains, during daytime, and at night without street lighting. Elderly female passengers were also found more likely to be fatally or severely injured in non-collision incidents if they lost their balance while boarding, alighting from, or standing on a bus. In comparison, the following factors were associated with a greater likelihood of fatal or severe injuries in collision incidents: elderly female passengers, standing passengers who lost balance, buses out of driver control, double-decker buses, collisions with vehicles or objects, and less urbanized areas. Practical Applications: Based on our comparative analysis, more targeted countermeasures, namely “4E” (engineering, enforcement, emergency, and education) and “3A” (awareness, appreciation, and assistance), were recommended to mitigate collision injuries and non-collision injuries to public bus passengers, respectively

    Injury severity of motorcycle riders involved in traffic crashes in Hunan, China: A mixed ordered logit approach

    No full text
    Issues related to motorcycle safety in China have not received enough research attention. As such, the causal relationship between injury outcomes of motorcycle crashes and potential risk factors remains unknown. This study intended to investigate the injury risk of motorcyclists involved in road traffic crashes in China. To account for the ordinal nature of response outcomes and unobserved heterogeneity, a mixed ordered logit model was employed. Given that the crash occurrence process is different between intersections and non-intersections, separate models were developed for these locations to independently estimate the impacts of various contributing factors on motorcycle riders’ injury severity. The analysis was based on the police-reported crash dataset obtained from the Traffic Administration Bureau of Hunan Provincial Public Security Ministry. Factors associated with a substantially higher probability of fatalities and severe injuries included motorcycle riders older than 60 years, the absence of helmets, motorcycle riders identified to be equal duty, and when a motorcycle collided with a heavy vehicle during the night time without lighting. Crashes occurred along county roads with curve and slope alignment or at regions with higher GDP were associated with an elevated risk of fatality of motorcycle riders, while unsignalized intersections were related to less severe injuries. Findings of this study are beneficial in forming several targeted countermeasures for motorcycle safety in China, including designing roads with appropriate road delineation and street lighting, strict enforcement for speeding and red light violations, promoting helmet usage, and improving the conspicuity of motorcyclists

    Hydrogenation of Carboxyl Nitrile Butadiene Rubber Latex Using a Ruthenium-Based Catalyst

    No full text
    Hydrogenated carboxyl nitrile rubber (HXNBR) is endowed with superior mechanical performance and heat–oxygen aging resistance via emulsion hydrogenation of its precursor, i.e., carboxyl nitrile rubber (XNBR). Herein, a ruthenium-based catalyst was prepared to achieve the direct catalytic hydrogenation of XNBR latex. The effects of a series of hydrogenation conditions, such as catalyst dosage, solid content and reaction temperature, as well as the hydrogen pressure, on the hydrogenation reaction were investigated in detail. We found that the hydrogenation rate fell upon increasing the solid content of the XNBR latex, with an XNBR conversion rate of 95.01 mol% in 7 h with 11.25 wt% solid content. As the reaction temperature was increased, the hydrogenation rate first increased and then decreased. The fastest reaction hydrogenation rate was reached at 140 °C, with an XNBR conversion of 95.10 mol% in 5 h. The hydrogenation rate was positively related with the hydrogen pressure employed in the reactor. In view of the safety and cost, a pressure rate of 1300 psi was considered optimal. Similarly, the hydrogenation rate can also be enhanced by adding more catalyst. When 0.05 wt% catalyst was added, the fastest hydrogenation rate was achieved. In summary, the following optimum hydrogenation conditions were determined by using a synthesized ruthenium-based catalyst: 11.25 wt% solid content of XNBR latex, 140 °C of reaction temperature, 1300 psi of hydrogen pressure and 0.05 wt% catalyst. The vulcanization, mechanical performance, aging resistance and oil resistance of the produced HXNBR under the above reaction conditions were systematically investigated

    Hydrogenation of Carboxyl Nitrile Butadiene Rubber Latex Using a Ruthenium-Based Catalyst

    No full text
    Hydrogenated carboxyl nitrile rubber (HXNBR) is endowed with superior mechanical performance and heat–oxygen aging resistance via emulsion hydrogenation of its precursor, i.e., carboxyl nitrile rubber (XNBR). Herein, a ruthenium-based catalyst was prepared to achieve the direct catalytic hydrogenation of XNBR latex. The effects of a series of hydrogenation conditions, such as catalyst dosage, solid content and reaction temperature, as well as the hydrogen pressure, on the hydrogenation reaction were investigated in detail. We found that the hydrogenation rate fell upon increasing the solid content of the XNBR latex, with an XNBR conversion rate of 95.01 mol% in 7 h with 11.25 wt% solid content. As the reaction temperature was increased, the hydrogenation rate first increased and then decreased. The fastest reaction hydrogenation rate was reached at 140 °C, with an XNBR conversion of 95.10 mol% in 5 h. The hydrogenation rate was positively related with the hydrogen pressure employed in the reactor. In view of the safety and cost, a pressure rate of 1300 psi was considered optimal. Similarly, the hydrogenation rate can also be enhanced by adding more catalyst. When 0.05 wt% catalyst was added, the fastest hydrogenation rate was achieved. In summary, the following optimum hydrogenation conditions were determined by using a synthesized ruthenium-based catalyst: 11.25 wt% solid content of XNBR latex, 140 °C of reaction temperature, 1300 psi of hydrogen pressure and 0.05 wt% catalyst. The vulcanization, mechanical performance, aging resistance and oil resistance of the produced HXNBR under the above reaction conditions were systematically investigated

    Approaches and genetic determinants in predicting response to neoadjuvant chemotherapy in locally advanced gastric cancer.

    No full text
    Gastric cancer remains a major health burden worldwide. There is near-universal agreement that neoadjuvant chemotherapy (NAC) is a preferred management for locally advanced gastric cancer (LAGC). However, the optimal approach for an individual patient is still not clear and remains controversial, which could be at least partly explained by the lack of predictive tools. The ability to predict chemosensitivity from NAC in routine clinical practice is difficult and is an area of intense investigation, especially in the Precision-Medicine Era. Available consistent evidence suggests that a favorable tumor histopathological response to NAC may be a useful positive prognostic marker in gastric cancer. Hence, it is reasonable to speculate that making the histopathological response from NAC predictable will dramatically facility the NAC and improve patients\u27 outcome. This review provides an overview on the current status of predictive biomarkers for histopathological response from NAC in LAGC, including clinicopathological variables, imaging and molecular testing. Furthermore, limitations and future perspectives are also discussed

    Oncogenic mechanisms of Lin28 in breast cancer: new functions and therapeutic opportunities.

    No full text
    The RNA binding protein Lin28 is best known for the critical role in cell development, recent researches also have implied its oncogenic function in various human cancers, including breast cancer. Specifically, aberrant Lin28 participates in multiple pathological processes, such as proliferation, metastasis, radiotherapy and chemotherapy resistance, metabolism, immunity and inflammation as well as stemness. In this review, we summarize the let-7-dependent and let-7-independent mechanism regulated by Lin28, focusing on its relation with tumor hallmarks in breast cancer, and subsequently discuss our present knowledge of Lin28 to develop a molecular-based therapeutic strategy against breast cancer

    Table1_The role of lncRNA H19 in tumorigenesis and drug resistance of human Cancers.DOCX

    No full text
    Systemic therapy is one of the most significant cancer treatments. However, drug resistance often appears and has become the primary cause of cancer therapy failure. Regulation of drug target, drug metabolism and drug efflux, cell death escape (apoptosis, autophagy, et al.), epigenetic changes, and many other variables are complicatedly involved in the mechanisms of drug resistance. In various types of cancers, long non-coding RNA H19 (lncRNA H19) has been shown to play critical roles in tumor development, proliferation, metastasis, and multiple drug resistance as well. The efficacy of chemotherapy, endocrine therapy, and targeted therapy are all influenced by the expression of H19, especially in breast cancer, liver cancer, lung cancer and colorectal cancer. Here, we summarize the relationship between lncRNA H19 and tumorigenesis, and illustrate the drug resistance mechanisms caused by lncRNA H19 as well. This review may provide more therapeutic potential targets for future cancer treatments.</p
    corecore