The Hepatitis B Virus Receptor Li, Wenhui
Annual review of cell and developmental biology,
11/2015, Letnik:
31, Številka:
1
Journal Article
Recenzirano
Hepatitis B virus (HBV) infection affects 240 million people worldwide. A liver-specific bile acid transporter named the sodium taurocholate cotransporting polypeptide (NTCP) has been identified as ...the cellular receptor for HBV and its satellite, the hepatitis D virus (HDV). NTCP likely acts as a major determinant for the liver tropism and species specificity of HBV and HDV at the entry level. NTCP-mediated HBV entry interferes with bile acid transport in cell cultures and has been linked with alterations in bile acid and cholesterol metabolism in vivo. The human liver carcinoma cell line HepG2, complemented with NTCP, now provides a valuable platform for studying the basic biology of the viruses and developing treatments for HBV infection. This review summarizes critical findings regarding NTCP's role as a viral receptor for HBV and HDV and discusses important questions that remain unanswered.
In all areas of business, employee attrition has a detrimental impact on the accuracy of profit management. With modern advanced computing technology, it is possible to construct a model for ...predicting employee attrition to minimize business owners’ costs. Despite the reality that these types of models have never been evaluated under real-world conditions, several implementations were developed and applied to the IBM HR Employee Attrition dataset to evaluate how these models may be incorporated into a decision support system and their effect on strategic decisions. In this study, a Transformer-based neural network was implemented and was characterized by contextual embeddings adapting to tubular data as a computational technique for determining employee turnover. Experimental outcomes showed that this model had significantly improved prediction efficiency compared to other state-of-the-art models. In addition, this study pointed out that deep learning, in general, and Transformer-based networks, in particular, are promising for dealing with tabular and unbalanced data.
Organophosphate esters (OPEs) are used in aircraft lubricating oil and hydraulic fluids, and, thus, airplane emissions are thought to be an important source of these chemicals in the environment. In ...this study, concentrations of 20 OPEs, comprising seven alkyl-OPEs, three chlorinated (Cl)-OPEs, seven aryl-OPEs, and three oligomeric-OPEs, were determined in outdoor air, soil, pine needles, river water, and outdoor dust samples collected around an airport in Albany, New York, in 2018. Elevated ∑OPE concentrations were found in outdoor air, soil, pine needles, outdoor dust, and river water in the ranges of 1320–20,700 pg/m3 (median: 3880), 1.16–73.1 (14.3) ng/g dry weight (dw), 23.2–534 (102) ng/g (dw), 153–2140 (824) ng/g (dw), and 174–24,600 (1250) ng/L, respectively. The total OPE concentrations in air, soil, water, and outdoor dust samples in the study area were dominated by Cl-OPEs, whereas those in pine needles were dominated by aryl-OPEs. The spatial distribution of OPEs in air, soil, and pine needles showed a gradual decreasing trend with increasing distance from the airport. A significant correlation was observed between ∑OPE concentrations in air and soil, and the fugacity ratio showed the flux of OPEs from air to soil. The spatial distribution of OPEs between air and pine needles was similar and highly correlated, suggesting that pine needles are suitable indicators of atmospheric OPE concentrations. In addition to urban activities, aircraft hydraulic/lubricant oils are a major source of OPEs in the vicinity of the airport. The average daily intake of OPEs via air inhalation and outdoor dust ingestion in the vicinity of the airport was up to 1.53 ng/kg bw/day for children and 0.73 ng/kg bw/day for adults.
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•OPEs are ubiquitous in air, soil, dust, river water and pine needles collected near airports.•The fugacity ratio showed the flux of OPEs from air to soil.•Aircraft oils/hydraulic fluids are a major source of OPEs around airports.•Pine needles reflect spatial gradient in atmospheric OPE concentrations.•Airports are a source of OPEs in the environment.
The wind environment quality at the height of pedestrians can significantly affect the thermal comfort and physical and mental health of pedestrians, promote the diffusion of air pollutants and ...inhibit the formation of urban heat island effect, and has been paid more and more attention in the field of urban and rural planning. This paper takes Jianlan Road commercial pedestrian Street as an example to maximize the thermal comfort of pedestrians. Based on CFD numerical simulation technology and space syntax theory, the pedestrian wind environment of the accessible space of the block is selected for quantitative research. Through numerical simulation, the influence of block spatial form on the wind environment at pedestrian height under the initial condition of uniform air flow is analyzed, and some suggestions are put forward for the optimization of block spatial form. Finally, the block optimization scheme is verified and simulated. The visualization results show that the wind environment quality of the optimized high-accessibility space is significantly improved, the proportion of comfort zone is increased from 58.2% to 86%, and the static wind rate is reduced from 41.8% to 14%. The wind environment optimization effect is obvious.
► Antibiotics widely existed in the Baiyangdian Lake. ► Geographical differences of antibiotic levels were greatly due to human activities. ► Salvinia natans exhibited strongest bioaccumulation for ...quinolones. ► Algae and aquatic plants may be at risk of antibiotics in surface water.
This study investigated the presence and distribution of 22 antibiotics, including eight quinolones, nine sulfonamides and five macrolides, in the water, sediments, and biota samples from Baiyangdian Lake, China. A total of 132 samples were collected in 2008 and 2010, and laboratory analyses revealed that antibiotics were widely distributed in the lake. Sulfonamides were the dominant antibiotics in the water (0.86–1563ngL−1), while quinolones were prominent in sediments (65.5–1166μgkg−1) and aquatic plants (8.37–6532μgkg−1). Quinolones (17.8–167μgkg−1) and macrolides from below detection limit (BDL) to 182μgkg−1 were often found in aquatic animals and birds. Salvinia natans exhibited the highest bioaccumulation capability for quinolones among three species of aquatic plants. Geographical differences of antibiotic concentrations were greatly due to anthropogenic activities. Sewage discharged from Baoding City was likely the main source of antibiotics in the lake. Risk assessment of antibiotics on aquatic organisms suggested that algae and aquatic plants might be at risk in surface water, while animals were likely not at risk.
•CO2 solubility in brine in silica nanopores are studied by molecular simulations.•As salinity increases, CO2 solubility in brine in silica nanopores decreases.•As pH increases, salt ions are ...strongly attracted to the silica pore surfaces.•Water hydration structures close to silica surfaces are dependent on pH and surface chemistry.•Low salinity and low pH are favored for CO2 solubility trapping tight sandstone formations.
Geological CO2 sequestration during CO2 enhanced oil recovery in tight formations is a technically and economically viable option to alleviate carbon emission. In tight formations, there existsare enormous number of nano-scale pores, which can be filled with connate and injected water. In addition, the salinity and pH of the formation water vary regionally. In this work, we used molecular dynamics simulations to study the effects of salinity and pH on CO2 solubility in brine in silica nanopores under typical geological conditions (353 K and ~ 175 bar). The pH effect is characterized by the deprotonation degree of silanol on the silica surface. We find that water mainly distributes around the silanol groups and CO2 mainly enriches in the areas where silanol groups are vacant. Na+ ions are generally depleted from the non-deprotonated silica surface, whereas they are strongly attracted to the pore surfaces in the deprotonated cases. The different water hydration structures around the non-deprotonated and deprotonated silanols arise from the accumulation of Na+ ions in the vicinity of SiO− groups. As salinity increases, the average densities of CO2 and water decrease in all silica nanopores and CO2 solubility in brine in silica nanopores decreases. On the other hand, as pH increases, water density increases but CO2 density decreases, resulting in a decrease of CO2 solubility in brine in silica nanopores. CO2 solubility in brine with a low pH range (~2–5) can be as high as 1.3–1.6 times of that in bulk, while it is comparable with that in bulk at a high pH range (~7–9). Overall, low salinity and low pH conditions are favored for geological CO2 sequestration by solubility trapping in tight formations.
The occurrence and profiles of 15 organophosphate flame retardants/plasticizers (OPFRs) (3 chlorinated Cl-, 2 aryl-, 5 non-Cl alkyl-, and 5 other types of OPFRs) were investigated in indoor air and ...dust collected from various microenvironments, including homes in the Albany area of New York State, United States. Concurrent indoor air and dust were collected from floors and window sills at homes and fire stations to investigate the partitioning of OPFRs between the vapor and particulate phases of air and dust. The total concentrations of OPFRs in bulk air (vapor plus particulate phases) were found at several tens to hundreds of ng/m3, with mean concentrations that ranged from 0.12 ng/m3 for tripropyl phosphate (TPP) to 43.8 ng/m3 for tris(1-chloro-2-propyl)phosphate (TCIPP). TCIPP, triethyl phosphate (TEP) and tris(2-butoxyethyl)phosphate (TBOEP) were the predominant compounds found in bulk air, vapor phase, and dust. Among the ten types of microenvironments studied, indoor air samples collected from automobile parts shops contained the highest concentrations of OPFRs (mean: 258 ng/m3), followed by electronics shops, nail salons/shops that sell nail polish, and home construction/interior products shops. Estimated daily intakes of OPFRs via inhalation of air, dermal sorption, and ingestion of dust were 149, 279, and 390 ng/kg bw/day, respectively, which suggested that dust ingestion is an important source of human exposure to OPFRs among the indoor exposure pathways studied.
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•15 OPFRs were measured in indoor air and dust from various microenvironments.•TCIPP was the predominant OPFR found in bulk air.•Automobile-part shops contained the highest concentrations of OPFRs.•Dust ingestion is a major source of human exposure to OPFRs.
As a major group of plasticizers and flame-retardants, organophosphate esters (OPEs) have attracted particular attention due to their wide occurrence and potential impacts on human health and ...ecosystems. In the present study, the occurrence and distribution of 14 OPEs, including seven Alkyl-OPEs, three Cl-OPEs, and four Aryl-OPEs, were investigated in 65 road dust samples collected from November to December 2014 in Beijing, China. Cl-OPEs were the predominant compounds in the road dust samples, with the median concentration of 646 μg/kg, followed by the Alkyl-OPEs (median 135 μg/kg) and Aryl-OPEs (median 129 μg/kg). Tris(2-chloro-1-methylethyl) phosphate (TCPP) was the most abundant OPE with the median concentration of 384 μg/kg. In addition, OPEs levels showed significant difference (p < 0.05) in the spatial distribution. Markedly higher levels of OPEs were observed in 2nd and 3rd ring road with heavy traffic and high population density, indicating that the traffic and population were important factors for this distribution pattern. It was further supported by the analysis of OPEs in roadside soil and indoor dust in the vicinity of road dust sample sites. Finally, the average daily dose (ADD) for OPEs via inhalation, dermal absorption, and ingestion was calculated to evaluate the carcinogenic and non-carcinogenic risks to residents exposed to OPEs in the road dust. Risk assessment revealed that the risk originating from exposure to OPEs of road dust is currently low in Beijing, China.
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•OPEs are ubiquitous in road dust samples in Beijing, China.•Cl-OPEs were the predominant compounds in the road dust samples.•Traffic and population may be important factors for the distribution of OPEs.•The risks to residents exposed to OPEs in the road dust were assessed.
Particle size is an important parameter of supported catalysts, but understanding the size-performance relationship is a challenge, especially in some complicated process. In this contribution, the ...particle size effect on CO2 hydrogenation to hydrocarbons over iron-based catalysts was deconvoluted into the effects on primary and secondary reactions. With a particle size range of 2.5–12.9 nm, the overall selectivity of C2+ hydrocarbons increases continuously, while that of CO decreases with the increasing size. The reverse water gas shift (RWGS) reaction and methanation are the main primary reactions and they are more sensitive within a particle size range of 6.1–12.9 nm. The formation of formate species is more favored, and thereby more CH4 is produced as a primary product on larger particles. The secondary process, the further hydrogenation of primary CO to hydrocarbons, is more sensitive within the particle size range of 2.5–9.8 nm, where the geometric effect or ensemble effect on larger particles leads to a higher chain-growth probability. More terrace sites may be conducive for C–C coupling, and the enhanced CO adsorption also benefits the secondary process. These findings highlight the deconvoluted particle size effect on CO2 hydrogenation and provide a dimension for understanding the catalysts in complicated reaction networks.