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Leaders' use of directive leadership has been found to increase when they face an unprecedented crisis. However, extant literature has failed to answer how directive leadership functions in this specific situation. Using the return‐to‐work after COVID‐19 lockdown as an example, we drew upon regulatory focus theory and conducted three studies to investigate the temporal effects of directive leadership on followers' regulatory foci and work role performance. In Study 1, we conducted an experience sampling method (ESM) study tracking a sample of 250 employees over 1 week when the COVID‐19 was originally reported in China. In Study 2, we conducted another ESM study on 125 employees over 2 weeks when the Omicron variant was surging in China. Both studies showed that the positive effect of daily directive leadership on followers' work promotion focus was strongest on the first day upon returning to work after lockdowns but decreased over time. In contrast, the positive effect of daily directive leadership on followers' work prevention focus increased throughout our sampling periods and became strongest on the last day. Moreover, our results indicate that daily directive leadership interacts with the elapsed time to influence two forms of work role performance – task proactivity and task proficiency – through the mediating roles of promotion focus and prevention focus, respectively. In Study 3, we conducted a vignette experiment employing a within‐ and between‐subject design on a sample of 171 U.S. participants. The results further supported the moderating role of elapsed time after returning to work in the differential effects of directive leadership on followers' two regulatory foci. [ABSTRACT FROM AUTHOR]

There are various secondary flow types in turbodrill's blade cascades, and all kinds of secondary flow have a significant effect on flow loss. In this paper, the stator cascade of φ160 mm turbodrill is taken as the research object, and the CFD method is used to analyze the secondary flow and its evolution. The origin and evolution mechanism of secondary flow is explained from the flow mechanism. The results show that when the working rotary speed is lower than the design rotary speed, the secondary flows are composed of suction surface separation vortex, horseshoe vortex, and passage vortex coexisting. The intensity of secondary flows increases with the decrease of rotary speed. When the working rotary speed is near the design rotary speed, the secondary flows include horseshoe vortex, passage vortex, and corner vortex. When the working rotary speed is higher than the design rotary speed, the secondary flows consist of pressure surface separation vortex and suction surface trailing edge separation vortex. Regardless of rotary speed, secondary flow intensity in the shroud region is greater than the hub region, which has a greater influence on the mainstream. In addition, compared with high rotary speeds, secondary flow intensity is greater at low rotary speeds, resulting in greater flow losses. [ABSTRACT FROM AUTHOR]

Montmorillonite clay was modified by pillaring with AlMn oxides in different Al/Mn ratios and intercalation of two kinds of N-containing polymers (i.e., chitosan (CS) and polyvinyl pyrrolidinone (PVP)) chains. The modified pillared montmorillonite clay (PM) showed a rich two-dimensional layered porous structure with tunable parameters, such as large interlayer spacing, high specific area, and large porous volume. They were then used as supports for Pd nanoparticles. As applied in coupling reactions of aryl halides with terminal alkynes, Pd@CS/AlMn-PM showed better comprehensive catalytic performance than Pd@PVP/AlMn-PM. This was mainly attributed to its higher specific area, stronger chelation to Pd species, and better solvent resistance. [ABSTRACT FROM AUTHOR]

This study presents a highly effective method for the photoinduced copper-catalyzed 1,2-amino oxygenation of 1,3-dienes. This synthetic strategy involves the dual roles of a single copper catalyst, which can act as a photosensitizer to generate nitrogen radicals and can also react with allyl radicals via single electron transfer (SET) processes. The method produces a range of quaternary carbon-centered allyl carboxylic esters and tertiary ethers with high yields and excellent regioselectivity under mild reaction conditions. [ABSTRACT FROM AUTHOR]

Objective. To explore the clinicopathological features and risk factors of patients with multiple primary breast cancers and thyroid disease. Method. An analytic approach of the reviewing method was adopted to analyze the clinical data of 80 breast cancer patients who were admitted to our hospital from January 2020 to January 2022. They were divided into an observation group (breast cancer with thyroid lesions) and a control group (simple breast cancer) according to whether the clinical data were accompanied with thyroid lesions to compare the clinical characteristics, pathological types, staging characteristics, and molecular biological characteristics of the two groups and to research the risk factors of the two groups. Result. (1) In the comparison of clinical data, the number of people aged ≥60 in the observation group was higher than that in the control group, and there was significant difference between the groups in the menopausal status data (P < 0.05). There was no statistical difference between the observation group and the control group in the comparison of clinical data of the body mass index, pregnancy frequency, labor frequency, and abortion history (P > 0.05). (2) In the comparison of pathological type and staging data, there was no statistical difference in the comparison of data on the pathological type, histological grade, T staging, N staging, and TNM staging between the observation group and the control group (P > 0.05). (3) In the comparison of data on molecular biology characteristics, there was a statistical difference in the nuclear proliferation antigen data between the observation group and the control group (P < 0.05). There was no statistical difference in the comparison of data on the estrogen receptor, progesterone receptor, human epidermal growth factor receptor-2, and molecular typing between the observation group and the control group (P > 0.05). (4) Logistic regression analysis showed that age, menopausal status, and nuclear proliferation antigen index were the high-risk inflammatory factors for combined thyroid lesions (P < 0.05). Conclusion. For patients with simple breast cancer, age, menopausal status, and nuclear proliferation antigen index are risk factors for combined thyroid lesions. Therefore, clinical attention should be paid to the above factors in the process of clinical treatment, and early-risk screening should be performed to achieve the purpose of improving the prognosis to the greatest extent. [ABSTRACT FROM AUTHOR]

In this paper, we aim to find unified estimates of fractional integrals involving Mittag–Leffler functions in kernels. The results obtained in terms of fractional integral inequalities are provided for various kinds of convex and related functions. A variant of Hadamard-type inequality is also presented, which shows the upper and lower bounds of fractional integral operators of many kinds. The results of this paper are directly linked with many recently published inequalities. [ABSTRACT FROM AUTHOR]

This study provides an accurate method for evaluating the fit of earphones, which could be used for establishing a linkage between interference/gap values with human perception. Seven commercial CAD software tools stood out and were explored for the analysis of the deviation between earphone and ear. However, the current deviation analysis method remains to be improved for earphone fit evaluation due to excessive points in the calculation (Geomagic Wrap and Siemens NX), lack of value on interference (Geomagic Control X), computation boundary required (Rapidform XOR/Redesign), repetitive computation with same points and inclined calculation line segment or even invalid calculation (Solidworks, Creo). Therefore, an accurate deviation analysis algorithm was promoted, which calculated the deviation between earphone and ear exactly and classified the interference set and gap set precisely. There are five main procedures of this algorithm, which are point cloud model pre-processing, the generation of distance vectors, the discrimination of interference set and gap set, the discrimination of validity, and statistical analysis and visualization. Furthermore, the usability and validity of the deviation analysis algorithm were verified through statistical analysis and comparing visual effects based on the earphone-wearing experiment. It is certified that the deviation analysis algorithm is appropriate for earphone fit evaluation and the eight indexes of this algorithm were proved to be related to subjective comfort scores. It is meaningful for ear-worn product fit analysis, design, and development phases. [ABSTRACT FROM AUTHOR]

In this paper, we investigate functional limit problem for path of a Brownian sheet, Chung's functional law of the iterated logarithm for a Brownian sheet is obtained. The main tool in the proof is large deviation and small deviation for a Brownian sheet. [ABSTRACT FROM AUTHOR]

This paper aims to find Hermite–Hadamard-type inequalities for a generalized notion of integrals called q − h -integrals. Inequalities for q-integrals can be deduced by taking h = 0 and are connected with several known results of q-Hermite–Hadamard inequalities. In addition, we analyzed q − h -integrals, q-integrals, and the corresponding inequalities for symmetric functions. [ABSTRACT FROM AUTHOR]

An insufficient number of ground support vehicles and improper dispatch have a significant impact on the quality of airport services. The reasonable dispatch of airport special vehicles can greatly improve the efficiency of airport services. In this paper, a bi-objective mixed-integer programming model is proposed which takes the minimum number of vehicles required and minimum total extra time cost of special vehicles as objectives. Additionally, the service constraint relationship of various vehicles and the reusable nature of vehicles to make full use of existing special vehicle resources are considered. To easily solve the model, the comprehensive scheduling problem is reduced to several sub-problems with parallel services and timing constraints. A non-dominated sorting genetic algorithm with multiple chromosomes and an elite strategy are developed to solve them separately. Finally, using the actual flight data of a domestic airport, we demonstrate the effectiveness of the proposed model and offer useful managerial insights. [ABSTRACT FROM AUTHOR]

Let S = ℤ ℊ 3 × ℤ I 1 I 2 be a commutative ring where ℊ , I 1 and I 2 are positive prime integers with I 1 ≠ I 2 . The zero-divisor graph assigned to S is an undirected graph, denoted as Y S with vertex set V(Y (S)) consisting of all Zero-divisor of the ring S and for any c, d ∈ V(Y (S)), c d ∈ E Y S if and only if cd =0. A topological index/descriptor is described as a topological-invariant quantity that transforms a molecular graph into a mathematical real number. In this paper, we have computed distance-based polynomials of Y R i-e Hosoya polynomial, Harary polynomial, and the topological indices related to these polynomials namely Wiener index, and Hyper-Wiener index. [ABSTRACT FROM AUTHOR]

Death receptor 5 (DR5) is a membrane protein that mediates exogenous apoptosis. Based on its function, it is considered to be a target for the treatment of cancers including prostate cancer. It is encouraging to note that a number of drugs targeting DR5 are now progressing to different stages of clinical trial studies. We collected 38 active compounds that could produce anti-prostate-cancer effects by modulating DR5, 28 of which were natural compounds and 10 of which were synthetic compounds. In addition, 6 clinically used chemotherapeutic agents have also been shown to promote DR5 expression and thus exert apoptosis-inducing effects in prostate cancer cells. These compounds promote the expression of DR5, thereby enhancing its function in inducing apoptosis. When these compounds were used in combination with the natural ligand of DR5, the number of apoptotic cells was significantly increased. These compounds are all promising for development as anti-prostate-cancer drugs, while most of these compounds are currently being evaluated for their anti-prostate-cancer effects at the cellular level and in animal studies. A great deal of more in-depth research is needed to evaluate whether they can be developed as drugs. We collected literature reports on small molecules against prostate cancer through modulation of DR5 to understand the current dynamics in this field and to evaluate the prospects of small molecules against prostate cancer through modulation of DR5. [ABSTRACT FROM AUTHOR]

In this article, we consider the class of modified h − convex functions and derive the famous Giaccardi and Petrovi c ′ type inequalities for this class of functions. The mean value theorems for the functionals due to Giaccardi and Petrovi c ′ type inequalities are formulated. Some special cases are discussed by taking different examples of function h. [ABSTRACT FROM AUTHOR]

• A stable electrolyte for proton-conducting solid oxide fuel cells (H-SOFC). • A viable and efficient technical approach involving Pt catalysis. • Effectively enhanced electrochemical performance. • Innovations in SOFC electrolyte processing. Pt modified BaZr 0.76 Y 0.2 Ni 0.04 O 3 (BZYN) is fabricated and characterized as a stable electrolyte for proton-conducting solid oxide fuel cell (H-SOFC). The utilization of X-ray diffraction method (XRD) and transmission electron microscopy (TEM) enables the identification of the presence of platinum (Pt) in both the crystal lattice sites and the grain interface. This occurrence contributes to a reduction in grain boundary resistance. Consequently, this phenomenon improves the conductivity of the electrolyte. The electrochemical performance of the single cell with Pt-modified BZY electrolyte is improved by the reduction of ohmic resistance and enhancement of ion migration. This signifies a noteworthy advancement in the creation of more efficient and durable proton-conducting SOFCs. [ABSTRACT FROM AUTHOR]

Sinking electrical discharge machining (EDM) is a vital machining technology used in modern mechanical manufacturing. However, the conventional sinking EDM, which utilizes an oil-based working medium, presents disadvantages such as low machining efficiency, harmful gas emissions, and fire hazards. Although researchers have attempted to use pure water as the working medium, pure water cannot replace oil and has not yet been industrially applied as a working medium because of its low machining efficiency and thick surface recast layer. Herein, we propose sustainable and green sinking EDM utilizing foam water (SEDM-FW) as the working medium, a method that uses pressurized foam water, ultrastrong energy discharge, and upward electrode feeding. The proposed method is cost effective, and its machining efficiency is more than three times higher than that of the conventional sinking EDM at the same peak current. The use of foam water instead of oil as the working medium solves environmental pollution problems associated with the conventional sinking EDM. In terms of environmental performance, the SEDM-FW produces gas byproducts that do not contain any harmful components, including 1,3-butadiene and benzene, which are present in the conventional sinking EDM. Compared with using pure water, using foam water as the working medium in conjunction with an appropriate gas-to-liquid ratio can double the machining efficiency, reduce the thickness of the recast layer by more than half, and reduce the size of surface microcracks. Using gas-dominated foam water, surface microcracks can be eliminated, and a zero-thickness recast layer can be achieved. [Display omitted] • A sustainable and green sinking EDM method (SEDM-FW) is proposed. • Foam water is used as the working medium, which replaces conventional oil and pure water. • Gas byproducts of SEDM-FW are completely harmless to humans and environment. • A proper gas-to-liquid ratio has higher MRR, lower REWR, and good surface integrity. • Gas-dominated foam water can eliminate microcracks and achieve zero-thickness recast layers. [ABSTRACT FROM AUTHOR]

High-resolution vehicular emissions inventories are important for managing vehicular pollution and improving urban air quality. This study developed a vehicular emission inventory with high spatio-temporal resolution in the main urban area of Chongqing, based on real-time traffic data from 820 RFID detectors covering 454 roads, and the differences in spatio-temporal emission characteristics between inner and outer districts were analysed. The result showed that the daily vehicular emission intensities of CO, hydrocarbons, PM 2.5 , PM 10 , and NOx were 30.24, 3.83, 0.18, 0.20, and 8.65 kg/km per day, respectively, in the study area during 2018. The pollutants emission intensities in inner district were higher than those in outer district. Light passenger cars (LPCs) were the main contributors of all-day CO emissions in the inner and outer districts, from which the contributors of NOx emissions were different. Diesel and natural gas buses were major contributors of daytime NOx emissions in inner districts, accounting for 40.40%, but buses and heavy duty trucks (HDTs) were major contributors in outer districts. At nighttime, due to the lifting of truck restrictions and suspension of buses, HDTs become the main NOx contributor in both inner and outer districts, and its three NOx emission peak hours were found, which are different to the peak hours of total NOx emission by all vehicles. Unlike most other cities, bridges and connecting channels are always emission hotspots due to long-time traffic congestion. This knowledge will help fully understand vehicular emissions characteristics and is useful for policymakers to design precise prevention and control measures. [Display omitted] [ABSTRACT FROM AUTHOR]

Zhangjiakou is an important wind power base in Hebei Province, China. The impact of its wind farms on the local climate is controversial. Based on long-term meteorological data from 1981 to 2018, we investigated the effects of the Shangyi Wind Farm (SWF) in Zhangjiakou on air temperature, wind speed, relative humidity, and precipitation using the anomaly or ratio method between the impacted weather station and the non-impacted background weather station. The influence of the SWF on land surface temperature (LST) and evapotranspiration (ET) using MODIS satellite data from 2003 to 2018 was also explored. The results showed that the SWF had an atmospheric warming effect at night especially in summer and autumn (up to 0.95°C). The daytime air temperature changes were marginal, and their signs were varying depending on the season. The annual mean wind speed decreased by 6%, mainly noted in spring and winter (up to 14%). The precipitation and relative humidity were not affected by the SWF. There was no increase in LST in the SWF perhaps due to the increased vegetation coverage unrelated to the wind farms, which canceled out the wind farm-induced land surface warming and also resulted in an increase in ET. The results showed that the impact of wind farms on the local climate was significant, while their impact on the regional climate was slight. [ABSTRACT FROM AUTHOR]

Based on the meteorological data (2009–2018) acquired by high-density automatic meteorological stations in the central urban area (CUA) of Beijing, this study adopted an urban-rural ratio method to construct a qr to quantify the impact of urbanization on the spatial and temporal distribution of specific humidity (q). And the urban morphological parameters such as building height (BH), building density (BD), floor area ratio (FAR), sky view factor (SVF), and land surface parameters including vegetation coverage (VC) and impervious coverage (IC) with 500-m spatial resolution in CUA were calculated, and furthermore, the relationships between the six spatial layout parameters and another indicator, urban heat island (UHI) intensity, and qr were studied. The results show that q of CUA is 81~114% of that of the suburbs, and the urban dry island (UDI) effect and urban wet island (UWI) effect coexist throughout the year. The maximum UDI occurs during autumn daytime and the maximum UWI appears at night in winter. The UDI effect is prone to occur in areas with VC < 11%, IC >85%, BH > 15 m, and BD > 24%, while the UWI effect is more likely to appear in areas with VC > 35% and FAR < 0.3. The contributions of the six urbanization parameters to the spatial change of qr in different time periods are 6.2 to 33.5%, and VC is the largest (33.5%), followed by BD (31.9%) and SVF (29.9%), and the main factor affecting the annual average qr is BD with the contribution of 18.9%. Compared with the urbanization parameters, the UHI is more important and the contribution to the change of q can be up to 35.7%. The results show that these spatial layout parameters are not sufficient to explain the main change in q, and more other parameters need to be considered. [ABSTRACT FROM AUTHOR]

A novel Gram-stain-negative, catalase- and oxidase-positive, motile, short rod-shaped bacterium designated BGMRC 6574T was isolated from stems of Aegiceras corniculatum collected from Hainan province, China. The strain grew at 25–37 °C (optimal at 28 °C), pH 5.0–10.0 (pH 7.0), and 3–8% (w/v) NaCl (3%). Based on the 16S rRNA phylogenetic analysis, the strain was closely related to Pararhizobium haloflavum MCCC 1K03228T (96.45% sequence similarity). The novel strain showed an average nucleotide identity value and a digital DNA–DNA hybridization of 72.62 and 27.1%, respectively, to P. haloflavum MCCC 1K03228T based on draft genome sequences. The G+C content of the genomic DNA was 64.7 mol%. The major respiratory quinone was Q-10. The strain possessed genes putatively encoding choline uptake and conversion to betaine gene clusters. The extract significantly delayed the lifespan of Caenorhabditis elegans compared to the control (P < 0.05). The major polar lipids were phosphatidylcholine, seven unidentified phospholipids, three unidentified ninhydrin-positive phospholipids, and two unidentified lipids. The major cellular fatty acid was C19:0 cyclo ω8c. The results of a polyphasic taxonomic study showed that strain BGMRC 6574T represents a new species of the genus Pararhizobium, and it was named Pararhizobium mangrovi sp. nov. The type strain is BGMRC 6574T (=KCTC 72636T = CGMCC 1.16783). [ABSTRACT FROM AUTHOR]

Glioblastomas are primary brain tumors that originate from glial stem cells or progenitor cells. There is a large difference in the incidence of glioblastoma between males and females. Studies revealed that the gender differences in the tumor may be attributable to the androgen receptor signaling axis. The incidence rate of glioblastoma in men is higher than that in women. Aberrant activation of the androgen receptor signaling pathway, or interactions between the androgen receptor signaling axis and other signaling axes promote the development of glioblastoma. Therefore, targeting the androgen receptor holds promise as a therapeutic approach for glioblastoma. This review investigates the dynamics of drug research into the treatment of glioblastoma by targeting the androgen receptor. The first finding in line with expectations is that androgen receptor antagonists, represented by enzalutamide, have been studied and shown to have anti-glioblastoma effects. In addition, it was found that the combination of 5-alpha reductase inhibitors and androgen receptor antagonists resulted in better therapeutic outcomes than each of them alone. Similar results were obtained with the combination of an epidermal growth factor receptor inhibitor and an androgen receptor antagonist. In addition, four small molecule compounds have been shown to exert significant anti-glioblastoma effects by directly or indirectly targeting the androgen receptor. Expectantly, one of these small molecules, seviteronel, progressed to the phase II clinical trial stage. These findings suggest that targeting the androgen receptor for glioblastoma may be a promising therapeutic option. [Display omitted] • Gender differences in glioblastoma patients are significant, with males significantly higher than females. • Androgen receptor expression positively correlates with glioblastoma grade. • Androgen receptor antagonists have made progress in the treatment of glioblastoma. [ABSTRACT FROM AUTHOR]

• The low-cost process of anaerobic-aerobic system was operated on a pilot scale. • The anaerobic carriers had similar performance to polyvinyl alcohol but lower cost. • The anaerobic and anoxic zones coexisted in aerobic polyurethane carriers. • Bacteria, archaea and fungi contribute to sludge reduction and nutrient removal. • Filamentous bacteria may be involved in initial attachment and renewal of biofilm. Two kinds of biocarriers were adopted and a combined process of "AMC (Anaerobic microorganism carrier)-UASB and PBG (Porous bio-gel)-MBBR" was operated at the pilot scale for the treatment of real textile wastewater. The influence mechanism of the two carriers on the start-up, pollutant removal and sludge reduction were investigated within 118 days of operation. The dominant functional bacteria in anaerobic and aerobic systems were identified by high-throughput sequencing, and the possible ways and related mechanisms of nutrient removal and sludge reduction were analyzed based on the data. 37.0 ± 7.5 % and 53 ± 12.7 % of COD removal efficiencies were achieved in anaerobic system and aerobic system, respectively. Ammonia nitrogen concentration decreased from 20 to 45 to 3.49 ± 0.54 mg/L after treatment. An anaerobe was found to be closely related to color removal, which existed in both anaerobic and aerobic systems, achieving 84.0 % of color removal. With the operation of the system, the sludge yield decreased gradually. The sludge yields of anaerobic and aerobic systems were calculated individually and compared with similar studies. Aging biofilms were characterized to explore the factors associated with biofilm renewal. [ABSTRACT FROM AUTHOR]

Wind corridor blueprints are an essential reference for climate planning that takes into account zones of fresh cold air, air channels as well as heat island alleviation zones. This article addresses the matter of how to plan urban wind corridors more efficiently by proposing a "ventilation potential coefficient" (VPC) as well as providing an index for natural cold sources. The study additionally proposes a surface urban heat island (SUHI) index as a means of evaluating the severity of the heat island effect. Based on these three indexes, a new method of categorizing urban climatic zones, called "Climatopes", is developed. Using the above methods, data from 2016 meteorological observation stations and Landsat8 satellites, as well as urban planning materials and basic geographical information on a scale of 1:2000 are used to create an Urban Climate Analysis Map (UCAnMap) and formulate a plan for the construction of wind corridors in the urban centre of Ji'nan. The results reveal that the intensity of urban heat islands in Ji'nan is closely related to a lack of natural cold sources, the specific layout of different types of land use as well as poor planning of urban "function zones". Moreover, there is a significant correlation between the VPC and other factors such as surface roughness length, building height, the density of building frontal area and floor area ratios. The potential wind corridors could also be determined based on the VPC. Based on an UCAnMap composed of 11 Climatopes and background wind environments, this article ascertains that it would be possible to construct a network of 3 Level One corridors (each over 500 m wide) and 11 Level Two corridors (each over 80-m wide). Additionally, regulatory measures and protective legislation are proposed for the corridors, as well as for the city's overall development. [ABSTRACT FROM AUTHOR]

Emergency rescue operations play a vital role in alleviating human suffering, reducing casualties, and cutting down economic losses. One key aspect in the management of these operations is the rational allocation of emergency relief materials, where the allocation is continuous, dynamic, and concurrent. This allocation should be made not only to minimize the emergency rescue losses, but also to reduce the cost of emergency rescue work. A reasonable and effective allocation scheme for emergency relief materials can be established to adapt to the continuity, dynamics, and concurrency of material distribution. In this work, we propose a multiobjective optimization model of emergency material allocation with continuous time-varying supply and demand constraints, where the objective is to minimize the losses and the economic cost incurred by the emergency rescue operations. The constrained optimization problem is handled through sequential unconstrained minimization techniques, and the multiobjective optimization is carried out by the fast nondominated sorting genetic algorithm (NSGA-II) with an elite strategy to obtain a Pareto solution set with fairness and balance of loss and cost. The loss and cost associated with the Pareto frontier are employed to find an appropriate noninferior solution and its corresponding material allocation scheme. We verify through several simulations the model feasibility and the effectiveness of the proposed method, which can provide decision support for continuous material allocation in emergency rescue operations. [ABSTRACT FROM AUTHOR]

Responding to an outbreak of a novel coronavirus [agent of coronavirus disease 2019 (COVID-19)] in December 2019, China banned travel to and from Wuhan city on 23 January 2020 and implemented a national emergency response. We investigated the spread and control of COVID-19 using a data set that included case reports, human movement, and public health interventions. The Wuhan shutdown was associated with the delayed arrival of COVID-19 in other cities by 2.91 days. Cities that implemented control measures preemptively reported fewer cases on average (13.0) in the first week of their outbreaks compared with cities that started control later (20.6). Suspending intracity public transport, closing entertainment venues, and banning public gatherings were associated with reductions in case incidence. The national emergency response appears to have delayed the growth and limited the size of the COVID-19 epidemic in China, averting hundreds of thousands of cases by 19 February (day 50). [ABSTRACT FROM AUTHOR]

The modern industry which widely utilized sinking electrical discharge machining (EDM) with kerosene has many problems including low processing efficiency, unsafety, unfriendly environmental impact, and poor machined surface accompanying with recast layer. In this paper, a new water-in-oil (W/O) nanoemulsion dielectric is proposed to overcome these shortcomings of conventional sinking EDM. The machining performance and mechanism of sinking EDM using W/O nanoemulsion are investigated in both rough and finishing machining by comparing with kerosene. The main characteristic parameters for evaluating machining performance, including material removal rate (MRR) and relative electrode wear rate (REWR) in rough machining, and machined surface quality in finishing machining are studied. Compared with kerosene, using W/O nanoemulsion as a dielectric in sinking EDM, a nearly 34 times higher MRR and a relatively lower REWR are obtained in rough machining, and a better machined surface with no recast layer is attained in finishing machining. [ABSTRACT FROM AUTHOR]

Na2 SeSO3 , which can be generated in situ by the reaction of Na2 SO3 with Se power, was found to be an odorless reagent for the selenenylation of alkyl halides to produce dialkyl diselenides. These products have been recently shown to be good catalysts for the Baeyer–Villiger oxidation of carbonyl compounds, for the selective oxidation of alkenes, or for the oxidative deoximation of oximes. By using aqueous EtOH as the solvent and avoiding the generation of a malodourous selenol intermediate, the selenylation reaction with Na2 SeSO3 is much more environmentally friendly than conventional methods. Owing to the cheap and abundant starting materials and selenium reagents, our novel synthetic method reduces the production costs of dialkyl diselenides as organoselenium catalysts, thereby advancing practical applications of organoselenium-catalysis technologies. [ABSTRACT FROM AUTHOR]

An efficient and regio-divergent method for both the C2 arylation and C3 diazenylation of C2,C3-unsubstituted indoles with aryltriazenes was developed. At room temperature, both reactions were carried out with HPF6/ionic liquids (ILs) as the promoter. The C2 arylation and C3 diazenylation activated by HPF6/ILs show remarkable reactivity, which results in corresponding products with yields of up to 99%. Notably, the practicality of the protocol was further demonstrated via gram-scale operations, late-stage modification and the reusability of the ILs. [ABSTRACT FROM AUTHOR]

• The ionic concentration which has never been studied in molecular dynamics simulations of coalescence behaviors is considered. • The electric field strength and the ionic concentration of droplets both affect the ionic distribution in droplets. • The corresponding ionic distribution at the leading poles of droplets and the electric field strength result in different coalescence behaviors of droplets. • The simulations of partial coalescence behaviors with different droplet ionic concentration are conducted and the simulation results are consistent with the experiment results. • Mechanism investigation of coalescence behaviors of conducting droplets by molecular dynamics simulations. In the presence of an electric field, three different coalescence behaviors of two conducting droplets (complete, partial, and non-coalescence) can occur by adjusting the strength of the electric field. Besides the strength of the electric field, the ionic concentration of droplets is also a major influencing factor for the coalescence behaviors. However, the mechanisms governing the coalescence behaviors have not been fully understood. In this study, the mechanism is investigated by molecular dynamics (MD) simulations and the ionic concentration, which has never been studied in MD simulations of coalescence behaviors, is also considered. Results show that the strength of the electric field and the ionic concentration of droplets affect the ionic distribution in droplets. The electric field strength also affects the charge transfer rate between droplets. Thus, the variations of electric field strength combined with droplet ionic concentration cause different coalescence behaviors of two conducting droplets. Moreover, simulations of partial coalescence at different droplet ionic concentration show that the size of daughter droplet is independent of the ionic concentration. This finding is in good agreement with the experimental results. [ABSTRACT FROM AUTHOR]

An efficient and green approach for the synthesis of azo dyes has been developed via the Brønsted acidic ionic liquid (IL) promoted diazo coupling reaction of naphthols with aryltriazenes. The reaction was carried out with the aryltriazenes as diazotizing agents, the Brønsted acidic ionic liquids as the promoter, and water as the green solvent at room temperature under air and metal-free conditions. Notably, the attractive advantages of the process include mild conditions with excellent yields, simple product isolation process, large-scale experiment, late-stage modification of pharmaceutical and recyclability of the promoter. In addition, the UV-vis spectral characteristics of the azo-dyes were investigated in DMSO. [ABSTRACT FROM AUTHOR]

Severe plastic deformation can be easily produced on metal surfaces by coupling the micro thermal shock from high peak pulse current and the micro mechanical shock from ultrasonics. Moreover, an efficient method for preparing a gradient nanostructured metal surface by coupling electric pulse and ultrasonics treatment (CEPUT) is developed in this study. The variation in microstructure and hardness of the specimen are investigated by electron backscatter diffraction, transmission electron microscope, X-ray diffraction, and nano-indentation measurement. Results showed that on the treated copper surface with CEPUT, the original grain boundaries are no longer recognized, the average grain size decreases from 48.77 μm to 39.22 nm, and the thickness of severe plastic deformation layer reaches to approximately 500 μm. Moreover, the hardness reaches to 2.105 GPa, and CEPUT also reduces the texture in the sample surface. A computational model is developed and the grain refinement mechanism is proposed to describe the electrical-thermal-mechanical phenomena during CEPUT. The proposed simple and cost-effective method of grain refinement and to produce the graded materials is effective, especially in the materials of high thermal and electrical conductivity. [ABSTRACT FROM AUTHOR]

Background: A re-emergence of scarlet fever has been noted in Hong Kong, South Korea, and England, UK, since 2008. China also had a sudden increase in the incidence of the disease in 2011. In this study, we aimed to assess the epidemiological changes before and after the upsurge. We also aimed to explore the reasons for the upsurge in disease in 2011, the epidemiological factors that contributed to it, and assess how these could be managed to prevent future epidemics.Methods: In this observational study, we extracted the epidemiological data for all cases of scarlet fever between 2004 and 2016 in China from the Chinese Public Health Science Data Center, the official website of National Health Commission of the People's Republic of China, and the National Notifiable Infectious Disease Surveillance System. These data had been collected from 31 provinces and regions in China and included geographical, seasonal, and patient demographic information. We used descriptive statistical methods and joinpoint regression to examine the spatiotemporal patterns and annual percentage change in incidence of the upsurge of disease across China.Findings: Between Jan 1, 2004, and Dec 31, 2016, 502 723 cases of scarlet fever, with ten fatalities, were reported in China, resulting in an annualised average incidence of 2·8807 per 100 000 people. The annual average incidence increased from 1·457 per 100 000 people in 2004 to 4·7638 per 100 000 people in 2011 (incidence rate ratio [IRR] 3·27, 95% CI 3·22-3·32; p<0·0001), peaking in 2015 (5·0092 per 100 000 people). The annual incidence after the 2011 upsurge of scarlet fever, between 2011 and 2016, was twice the average annual incidence reported between 2004 and 2010 (4·0125 vs 1·9105 per 100 000 people; IRR 2·07, 95% CI 2·06-2·09; p<0·0001). Most cases were distributed in the north, northeast, and northwest of the country. Semi-annual patterns were observed in May-June and November-December. The median age at onset of disease was 6 years, with the annual highest incidence observed in children aged 6 years (49·4675 per 100 000 people). The incidence among boys and men was 1·54 greater than that among girls and women before the upsurge, and 1·51 times greater after the upsurge (p<0·0001 for both). The median time from disease onset to reporting of the disease was shorter after the upsurge in disease than before (3 days vs 4 days; p=0·001).Interpretation: To our knowledge, this is the largest epidemiological study of scarlet fever worldwide. The patterns of infection across the country were similar before and after the 2011 upsurge, but the incidence of disease was substantially higher after 2011. Prevention and control strategies being implemented in response to this threat include improving disease surveillance and emergency response systems. In particular, the school absenteeism and symptom monitoring and early-warning system will contribute to the early diagnosis and report of the scarlet fever. This approach will help combat scarlet fever and other childhood infectious diseases in China.Funding: National Key R&D Plan of China Science and key epidemiological disciplines of Zhejiang Provincial Health of China. [ABSTRACT FROM AUTHOR]

This article proposes a method for estimating the surface urban heat island intensity (SUHI) of urban areas, which addresses prior difficulties in the determination of rural contexts that may be used as a point of comparison. Based on indexes produced using this method, as well as remotely sensed datasets, the article compares the temporal and spatial characteristics of SUHIs within three major urban agglomerations (the Beijing-Tianjin-Hebei, the Yangtze River Delta, and the Pearl River Delta) and six typical metropolises. The article also examines the influence of socioeconomic factors on SUHI. The study revealed that this method is able to objectively monitor regional-scale SUHIs. The climate of the area studied is probably a determining factor in the seasonal variation of SUHIs. Research from the last 5 years (2010-2014) demonstrates that the urban heat island effect within the three urban agglomerations and five metropolises is serious. From 1994 to 2014, the average SUHI value for central urban areas rose from 0.4 to 2.3 K, while the total area where the SUHI value was >3.0 K increased from 1938 to 29,690 km2. The morphology of heat islands is significantly influenced by urbanization, meaning that heat islands within the areas studied will only continue to grow. Urban population and electricity consumption are the socioeconomic factors that exerted the greatest influence on the size of heat islands in China’s major urban agglomerations. However, it is likely that economic measures designed to mitigate the UHI effect will differ in effectiveness from one urban agglomeration to another. [ABSTRACT FROM AUTHOR]

A series of polyaniline (PANI)-supported palladium nanoparticles (Pd@PANIs) were fabricated from electron-deficient and -enriched substituted anilines and palladium chloride. PANIs’ support effect in the Pd@PANIs-catalyzed Ullmann reaction of aryl iodides for generation of biaryls was then studied. The results revealed that, though having similar Pd content and morphology, these Pd@PANI catalysts behaved quite differently in catalytic activities in the Ullmann reaction of aryl iodides, with the electron-enriched PANI supports having obviously enhanced activities for the reaction. Mechanistic studies revealed this is due to the stronger coordination of the nitrogen ligands on the electron-enriched PANI support with the Pd centers, higher adsorption rates of the reactant on the electron-enriched Pd@PANI catalysts, especially those promoted by the Pd loading, and easier generation and higher ratio of the Pd(0) species in the catalyst, which is the active catalysts in the Ullmann reaction responsible for the products’ yields and the TONs of the reactions. In contrast, the specific surface area of the Pd@PANI catalyst is found to have little influence on the catalytic activity and adsorption capacity of the catalysts, and thus its influence may be omitted in the present Pd@PANIs-catalyzed Ullmann reaction of aryl iodides. Therefore, a simple fine tuning of the PANI support’s electronic property by introducing electron-donating groups can be an effective protocol for enhancing the catalyst’s activity. This work may be the first example of a support effect study in PANI-supported metal nanoparticle-catalyzed reactions. [ABSTRACT FROM AUTHOR]

Severe wear is a hot issue in the development of petroleum engineering which has attracted many attentions. To address this problem, a nickel-based alloy (NiCrBSiWFeCoC) coating was proposed and prepared using High-velocity oxy-fuel (HVOF) technique. The wear properties of as-sprayed composite coating were studied. The sliding wear experiments of both as-sprayed and uncoated specimens were conducted on a tribometer. The obtained results indicated that the both wear rates increased obviously with the increase in normal load, however, the friction coefficients decreased with the increase in normal load. Based on the comprehensive analyses, it can be concluded that the as-sprayed coating exhibited better wear resistance. Furthermore, the wear behaviors can be investigated by analyzing the worn morphologies. This research can provide insight into the wear prevention in petroleum engineering and decreases the failure of equipments or pipelines. [ABSTRACT FROM AUTHOR]

Material erosion caused by continuous particle impingement during hydraulic fracturing results in significant economic loss and increased production risks. The erosion process is complex and has not been clearly explained through physical experiments. To address this problem, a multiple particle model in a 3D configuration was proposed to investigate the dynamic erosion process. This approach can significantly reduce experiment costs. The numerical model considered material damping and elastic-plastic material behavior of target material. The effects of impact parameters on erosion characteristics, such as plastic deformation, contact time, and energy loss rate, were investigated. Based on comprehensive studies, the dynamic erosion mechanism and geometry evolution of eroded crater was obtained. These findings can provide a detailed erosion process of target material and insights into the material erosion caused by multiple particle impingement. [ABSTRACT FROM AUTHOR]

The wear failure problem of fracturing tools applied for oil and gas production could be improved by preparing WC based coating using high-velocity oxy-fuel (HVOF) method. The comprehensive wear properties of the thermal spray WC based coatings were studied. To simulate the downhole environment, wear tests under wet condition were performed in water-in-oil (W/O) fracturing fluid. The experimental results indicated that the WC composite coatings exhibited lower friction coefficient, higher hardness and better wear resistance compared with that of the uncoated specimens. Furthermore, wear mechanisms of the thermal spray WC coating can be obtained by analyzing the worn surface. [ABSTRACT FROM AUTHOR]

In oil and gas industries, erosion wear presents a major problem in the hydraulic fracturing process and severely reduces the erosion life of tools. Tungsten carbide (WC)-based high-velocity oxygen-fuel (HVOF) thermal spray coating is widely applied to improve surface properties. However, the erosion wear mechanism of this coating in liquid–solid two-phase flows is not clearly understood. Therefore, in this study, the HVOF thermal spray WC-based coating was characterized, and the erosion behavior of the coating was studied in a wet erosion test rig. Results showed that the experimental parameters, namely, attack angle, impact speed, particle size, and erosion time, exerted significant effects on the erosion rates of the specimens. The coated specimens exhibited higher hardness and better erosion wear resistance than the uncoated substrate due to the hard phase particles of the coating. The surfaces of the coated specimens showed microcutting, craters, and brittle chipping, as a visible manifestation of material removal. Furthermore, the erosion wear mechanism of the deposited coating was established by analyzing the eroded morphologies. The findings of this study can help enrich the understanding of the erosion wear mechanism of WC coatings in liquid–solid two-phase flows. [ABSTRACT FROM AUTHOR]

Urbanization directly drives rural to urban population migration and indirectly causes west to east migration in China, two phenomena that may significantly impact China's greenhouse gas emissions given its huge population and vast difference between the west rural and east urban areas. We analyzed these two phenomena by turning emissions into a per capita term, and extending the impact from the traditional urbanization rate effect to include population density effect. Our results show that population density has actually been the dominant demographic player in changing per capita emissions for the past two decades in China, and its elasticity changed from positive in economically less-developed provinces to negative for the developed provinces. This study therefore provides a new perspective in the study of the relationship between urbanization and greenhouse gas emissions, and our results indicate that population density change should be taken into account to accurately assess the impact of urbanization. [ABSTRACT FROM AUTHOR]

Material erosion due to particle impingement has drawn extensive attention in oil and gas industries. During fracturing process, the high-speed impact of particles entrained in fracturing fluid system result in severe tool damage. Erosion behavior is a complex process and is affected by many parameters, such as particle velocity, particle size, impact angle, and target material properties. Simulating the dynamic erosion process is helpful to understand the erosion behavior of target materials and to predict the erosion phenomenon under different working conditions. In this paper, finite element analysis (FEA) was performed using multiple-particle impact model in a 3D configuration. The numerical model considered the material damping and elastic-plastic behavior of the target material. The effects of strain hardening and rate were considered in the non-linear material model. The influences of impact parameters on the erosion characteristics were investigated. Experiments were conducted to supplement the study of erosion mechanisms. Comprehensive studies show that the dynamic erosion mechanisms, which can provide guidance for optimizing process parameters, decrease the erosion rate obtained. [ABSTRACT FROM AUTHOR]

Cleaner production and sustainability are of crucial importance in the field of machining processes where great amount of energy is being consumed. This paper outlines the application of gray relational theory in order to optimize the machining parameters for Ti6Al4V in high-speed dry electrical discharge milling (EDM) using a tubular graphite electrode. The objective of optimization is to achieve simultaneously the minimum power consumption and the maximum material removal rate (MRR). The maximum MRR 5634 mm/min was obtained with a power consumption of 7.61 kW. MRR stayed in the similar level, and power consumption was reduced by 17.82 % compared with that of the parameters in our previous study. Current is the main effect factor on MRR and power consumption. The corresponding single pulsed experiments were conducted to deeply explore the reasons for the influence of air pressure and electrode rotation speed on the MRR and power consumption. [ABSTRACT FROM AUTHOR]

Fracturing tools such as sliding sleeves, fracturing balls, and ball seats are extensively used for downhole fluid and pressure control. The ball seat is one of the most important components in the multistage fracturing system. After the hydraulic fracturing treatment is complete, the traditional ball seat restricts the production flow and thus must be removed. Extra mechanical interventions are then required to mill out the ball seat after fracturing treatment. In this work, an innovative fracturing ball seat that can be dissolved was proposed and investigated using a controlled electrolytic method (CEM). The newly designed ball seat can be removed through a specific corrosion rate to facilitate an unrestricted flow path for oil and gas production. Comprehensive experiments on the CEM were conducted. The effects of various electrolytic parameters, such as electrolysis current, electrode distance, electrolytes, and tool thickness, on the material removal rate of the ball seat and sliding sleeve were investigated. Experimental results show that the electrolytic parameters significantly affected the electrolytic characteristics. Aluminum alloy is suitable for the manufacture of dissolvable fracturing tool because of its good strength and high electrolytic rate. The study on the newly proposed CEM could provide insights into the design of novel fracturing tools and intelligent well completion systems. [ABSTRACT FROM AUTHOR]

This paper proposes a novel, efficient, and environmental friendly machining method named high-speed dry electrical discharge machining (EDM) milling. The material removal rate of this method is much higher than that of conventional EDM and is also higher than that of traditional mechanical machining method for materials that are 'difficult to machine.' Nickel-based superalloy Inconel 718 is widely used in the aerospace field as its surface integrity exerts significant effects. In this study, the microscopic characteristics, such as surface roughness, re-solidified layer, micro-hardness, micro-crack, and micro-void, of the machined Inconel 718 in high-speed EDM milling using air dielectric were studied compared with those using liquid dielectric. The formation mechanism of the microscopic characteristics was revealed. Experimental results showed that the machined Inconel 718 in high-speed EDM milling using air dielectric exhibited smaller surface roughness, thinner thickness of re-solidified layer, and smaller and less micro-cracks compared with those using liquid dielectric. Theoretical and technical foundations were laid for the industrial application of this novel machining method. [ABSTRACT FROM AUTHOR]

The upstream pumping mechanical seal has been widely used in recent years because of its excellent seal performance. However, it is difficult to machine using the common manufacturing technology because of its complex microgroove structure, high machining accuracy requirement, and difficult-to-machine material application. In this work, a novel method that combines composite electroplating and gradient composite brush electroplating is developed for manufacturing the upstream pumping mechanical seal. The effects of the hybrid composite electroplating parameters, such as the SiC concentration in the electroplating liquid, current density, stirring speed of the electroplating solution, on the microstructure of the growth layer, and wear performance, are investigated. Results show that the SiC distribution on the surface of the growth layer is uniform, the quantity of the SiC particle deposited in the growth layer, and the microhardness of the growth layer increases gradually from the bottom to the top of the metal matrix ring. Moreover, slight abrasive wearing occurs with appropriate manufacturing parameters: a SiC concentration of 40 g/L, current density of 4.5 A dm, and stirring speed of 300 r/min. [ABSTRACT FROM AUTHOR]

Wear phenomenon has caused severe damage or failure of fracturing tools in oil and gas industry. In this paper, influence of heat treatment on the mechanical properties and wear resistance of fracturing tool made of lamellar graphite grey cast iron were investigated. The surface composition and microstructure were characterized by X-ray diffraction (XRD) and metallographic microscope. Sliding wear tests were performed to study the tribological behavior. Tests results showed that wear rates of treated specimens decreased by 33 %. Besides, worn morphology and wear debris were analyzed using Scanning electron microscope (SEM) and Energy dispersive X-ray spectra (EDS). Wear failure mechanisms of specimens were identified. Furthermore, on-site experiment results indicated that wear loss of treated samples decreased by 37.5 %. The wear life of hydraulic fracturing tools can be improved obviously by the heat treatment. [ABSTRACT FROM AUTHOR]

With the increasing requirement for energy, unconventional oil and gas resources such as shale gas, shale oil and coalbed methane play a vital role in energy supply. Therefore, the erosion phenomenon which causes serious tool damage during exploitation has attracted tremendous attention and research interest. The objective of this paper is to investigate the effect of flow characteristics on the geometry evolution process of the downhole fracturing tool. Computational fluid dynamics (CFD) simulation with standard k-ε turbulence model and Lagrangian particulate flow model is carried out to investigate the fracturing process. Effects of flow rate, fluid viscosity and proppant size on pressure drop and erosion rate are studied. It is found that erosion rates increase significantly with the increasing flow rate, while decrease with increase of fluid viscosity and proppant size. Furthermore, second and subsequent impacts occur during fracturing. The maximum erosion rate appears around the port of sliding sleeve. The geometry evolution of sliding sleeve can be predicted through the analysis of erosion information. Moreover, a general agreement between numerical results and field data is achieved. These numerical simulations can provide useful guidance for prolonging the erosion life of fracturing tool and improving exploitation efficiency. [ABSTRACT FROM AUTHOR]

As the world's top carbon dioxide emitter, China is expected to reach its emissions peak by 2030. East and south coastal China contribute nearly one-third of the emissions in China, and therefore play a critical role in achieving the national goal of emission control. This study analyzes the driving forces of east and south coastal China's energy-related emissions and their provincial characteristics by applying the logarithmic mean divisia index method. The emissions in this region were found to double from 2000 to 2012, along with three and two folds increase in the economy and energy consumption. The result suggests a persistent connection between economic growth and emission even in this socioeconomically advanced region. The per capita emissions are lower than most regions of China at a given economic level, and are expected to be lower than select developed nations when reaching their corresponding economic levels. Energy efficiency has been the leading force in reducing emission growth, and we differentiate the provinces into three distinct low-carbon developmental stages. There is no significant influence from either the economic or energy structure change, indicating great emission reduction potential from structure decarbonization especially when compared to advanced nations. These results suggest that the dual effort of enhancing energy efficiency and decarbonizing the economic and energy structure would probably serve the goal of total emission control more effectively and efficiently, and factor driven emission reduction strategies are needed in these geographically and socioeconomically similar regions. The study expands on the current knowledge by analyzing the interprovincial commonality and variation of this pilot region in China, and therefore provides a stepwise view of the emission driving forces for emerging economies. [ABSTRACT FROM AUTHOR]

A three-step model of the transitional phase inversion (TPI) process for the formation of water-in-oil (W/O) emulsions is presented. Three types of emulsions exist in an emulsification process at different oil–water ratios and hydrophilic–lipophilic balance (HLB). A stable W/O emulsion was obtained using Sorbitan oleate (Span 80) and polyoxyethylenesorbitan monooleate (Tween 80) with a specified HLB and oil volume fraction. Oil was added into water, which contained the water-soluble surfactant, to dissolve the oil-soluble surfactant. This route allowed TPI to occur, and an interesting emulsification process was observed by varying the HLB, which corresponded to the change in the oil–water ratio. Two types of emulsions in the emulsification process were found: transition emulsion 1 (W/O/W high internal phase emulsion) and target emulsion 2 (W/O emulsion with low viscosity). This study describes the changes that occurred in the emulsification process. [ABSTRACT FROM AUTHOR]

High-speed near dry electrical discharge machining (EDM) is a novel and promising machining method, which obtains higher material removal rate, lower surface roughness and thinner width of overcut compared with that of high-speed dry EDM. Moreover, debris deposition on the machined surface and electrodes are significantly reduced and an obviously thin heat affected zone is obtained using the near dry dielectric (mist). In this study, a low-flux pump is utilized to supply deionized water at a controlled rate to the high-speed air pipe, which affords a mist dielectric to the machining process. Compared with dry EDM, the high-speed near dry EDM improves the cooling capacity and increases the dielectric strength of the dielectric. Furthermore, electrode injection flushing assisted by side flushing of high-speed mist was used to reduce debris deposition and improve cooling capacity. Comparative milling experiments of Ti6Al4V were conducted under the dry and near dry conditions using the different flushing ways. The effects of current, pressure, droplet size, electrode rotation speed, and droplet density on the material removal rate, surface roughness, width of overcut in continuous machining and material removal weight, trace length, trace width in single pulse machining were studied. In addition, scanning electron microscope, X-ray diffractometer, energy dispersive spectrometer, and micro-hardness tester were also used to study the micro-characters of the machined materials. [ABSTRACT FROM AUTHOR]

Recently, Aldehyde dehydrogenase 1A1 (ALDH1A1) has been proposed to be a common marker of cancer stem cells and can be induced by benzo[a]pyrene (B[a]P) exposure. However, the underlying mechanism of how ALDH1A1 contributes to B[a]P-induced carcinogenesis in human bronchial epithelial cells remains unclear. Here, we found that B[a]P up-regulated expression levels of stem cell markers (ABCG2, SOX2, c-Myc and Klf4), epithelial-mesenchymal transition (EMT) associated genes ( SNAIL1 , ZEB1 , TWIST and β - CATENIN ) and cancer-related long non-coding RNAs (lncRNAs; HOTAIR and MALAT - 1 ) in malignant B[a]P-transformed human bronchial epithelial cells (BEAS-2B-T cells), and these up-regulations were dependent on increased expression of ALDH1A1. The inhibition of endogenous ALDH1A1 expression down-regulated expression levels of stem cell markers and reversed the malignant phenotype as well as reduced the chemoresistance of BEAS-2B-T cells. In contrast, the overexpression of ALDH1A1 in BEAS-2B cells increased the expression of stem cell markers, facilitated cell transformation, promoted migratory ability and enhanced the drug resistance of BEAS-2B cells. Overall, our data indicates that ALDH1A1 promotes a stemness phenotype and plays a critical role in the BEAS-2B cell malignant transformation induced by B[a]P. [ABSTRACT FROM AUTHOR]

Zanthoxylum bungeanum (ZB) is a medicinal plant that is widely cultivated in arid and semi-arid areas. The drought tolerance mechanism of ZB has not yet been clearly elucidated. Here, the physiological indicators, transcriptome, and metabolome of two ZB cultivars with contrasting drought tolerance (FJ, Z. bungeanum cv. 'Fengjiao'; HJ, Z. bungeanum cv. 'Hanjiao') were analyzed under drought stress. The results showed that HJ was more tolerant to drought stress, with stronger antioxidant enzyme activities, higher contents of soluble sugar, soluble protein and proline as well as lower content of malondialdehyde and H 2 O 2. Transcriptome analysis revealed that there were more differentially expressed genes in FJ than in HJ throughout the drought treatment. Metabolome analysis identified 911 metabolites, which were divided into 10 classes. The up-regulated metabolites in HJ were mainly amino acids and their derivatives and flavonoids; those in FJ were mainly amino acids and their derivatives and alkaloids. Candidate structural genes related to drought tolerance and key transcription factor genes involved in drought-response pathways were sheltered by weighted gene co-expression network analysis (WGCNA). Conjoint analysis of the transcriptome and metabolome emphasized the importance of respiration metabolism in enhancing drought tolerance. In general, HJ improves drought tolerance by enhancing antioxidant enzyme activities; increasing the intensity of the pentose phosphate pathway; promoting the accumulation of osmotic substances; stimulating the synthesis of abscisic acid, brassinosteroid, and heat shock proteins; and accelerating signal transduction. The results improve our understanding of the molecular mechanism of drought tolerance in ZB and provide new insights for molecular breeding of ZB as well as other crops. [Display omitted] • A drought response pattern in Zanthoxylum bungeanum plant was proposed. • Respiration pathways were commonly annotated by transcriptome and metabolome. • The pentose phosphate pathway intensity was enhanced under drought stress. • Key transcript factors and structural genes response to drought were identified. [ABSTRACT FROM AUTHOR]