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• Fe(IV)/Fe(V) can be electrochemically produced from both Fe(II) and Fe(III). • Fe(II) enhanced phenolics' electrooxidation in high chloride conditions. • Fe(II) and Fe(III) inhibited the generation of chlorinated byproducts. • Fe(II) and Fe(III) reduced the toxicity of electro-treated industrial wastewater. • Fe(II) showed superior improving effects than Fe(III) in high chloride conditions. Electrochemical advanced oxidation processes (EAOPs) have shown great promise for treating industrial wastewater contaminated with phenolic compounds. However, the presence of chloride in the wastewater leads to the production of undesirable chlorinated organic and inorganic byproducts, limiting the application of EAOPs. To address this challenge, we investigated the potential of incorporating Fe(II) and Fe(III) into the EAOPs with a boron-doped diamond (BDD) anode under near-neutral conditions. Our findings revealed that both Fe(II) and Fe(III) facilitated the generation of high-valent iron-oxo species (Fe(IV) and Fe(V)) in the anodic compartment, thereby reducing the oxidation contribution of reactive chlorine species. Remarkably, the addition of 1000 μM Fe(II) under high chloride conditions resulted in over a 2.8-fold increase in the oxidation rate of 50 μM phenolic contaminants at pH 6.5. Furthermore, 1000 μM Fe(II) contributed to a reduction of more than 66% in the formation of chlorinated byproducts, consequently enhancing the biodegradability of the treated water. Additionally, transitioning from batch mode to continuous flow mode further amplified the positive effects of Fe(II) on the EAOPs. Overall, this study presents a modified electrochemical approach that simultaneously enhanced the degradation of phenolic contaminants and improved the biodegradability of wastewater with high chloride concentrations. [Display omitted] [ABSTRACT FROM AUTHOR]

• Fabrication of triple-layered vascular grafts that mimic native blood vessels. • Graft compliance is regulable and compatible with sheep carotid artery. • Triple-layered vascular grafts are promising as small-diameter vessel replacements. There is an urgent clinical for small diameter vascular grafts (SDVGs) for use in the treatment of coronary artery disease. Moreover, biodegradable SDVGs are drawing increasing attention because they have the potential to restore vascular function with the degradation of vascular graft and tissue regeneration. In this study, we designed triple-layered SDVGs to mimic the native arterial structure, with each layer contributing its unique porosity to the porous structure. We evaluated triple-layered SDVGs in a sheep carotid arterial replacement model. After implantation for 12 months, two grafts were patent and indicated the feasibility of using grafts in large animals. Nevertheless, it was determined that both grafts formed aneurysms at the proximal end. The prevention of such aneurysms remains a challenge for future investigation. Image, graphical abstract [ABSTRACT FROM AUTHOR]

This paper studies the risk spreading ability of cryptocurrencies and their contribution to the systemic risk during the period from 2018 to 2022. Three different network centrality approaches are employed to measure the risk spreading ability of cryptocurrencies both in breadth and depth, and from perspectives of local and global information. We also measure the contribution of cryptocurrencies to the systemic risk via Δ CoV aR , and detect what contributes to the systemic risk. Our findings show that cryptocurrencies with larger risk spreading ability, as well as others that experience decline in prices or high turnover, contribute more to the systemic risk. • We measure cryptocurrencies' risk spreading ability via a novel gravity model. • Exogenous events have led to a rise in cryptocurrencies' systemic risk exposure. • Cryptocurrencies with larger risk spreading ability contribute more to the systemic risk. [ABSTRACT FROM AUTHOR]

The photolysis of chlorine by UV light leads to the formation of the hydroxyl radicals (OH) as well as reactive chlorine species (RCS) that can be effective as advanced oxidation processes (AOPs) for water treatment. Much of the research to date has been done at laboratory- or bench-scale. This study reports results from a model that demonstrates that the relative effectiveness of the UV/Cl 2 AOP compared to the more traditional UV/H 2 O 2 AOP is a function of optical path length. As such, the relative effectiveness of the two treatment options evaluated at small scale may not reflect the relative performance at full-scale, making results previously obtained at small-scale potentially less scalable. This study therefore compares the performance of UV/Cl 2 to UV/H 2 O 2 at a full-scale water treatment plant, using sucralose and caffeine as spiked surrogates for contaminants that are reactive solely to OH radicals, and to both OH and RCS, respectively. pH was varied between 6.5 and 8.0. The results demonstrated that when using a medium pressure UV lamp, UV/Cl 2 might lead to approximately twice the production of OH radicals as UV/H 2 O 2 at pH 6.5 when using the same molar oxidant concentration, but adding chlorine to the UV reactor at pH 8.0 had a negligible impact on OH radical concentration in comparison to UV alone. The study also confirmed previous small-scale results that RCS can be a major contributor to UV/Cl 2 treatment for compounds such as caffeine that are susceptible to RCS, with UV/Cl 2 effective at both pH 6.5 and 8.0 for such compounds. Disinfection byproducts were monitored, with adsorbable organohalide (AOX) formation increasing by approximately 10 μg-Cl/L due to chlorine photolysis, but only at pH 6.5 and not at pH 8.0. This implies that UV/Cl 2 might increase AOX mostly due to reaction between OH and organic precursors to make them more reactive with chlorine, and not due to RCS. The formation of specific DBPs of current or emerging regulatory interest was minimal under all conditions, except for chlorate. Chlorate yields were in the order of 6–18% of the photolysed chlorine. Image 1 • The relative effectiveness of MP UV/H 2 O 2 versus UV/Cl 2 is light path length dependent. • UV/Cl 2 produced twice as much OH radical as UV/H 2 O 2 at pH 6.5. • The reactive chlorine species generated in UV/Cl 2 at pH 8.0 did not contribute to AOX formation. • Chlorate yields were in the order of 6–18% of the photolysed chlorine in UV/Cl 2. [ABSTRACT FROM AUTHOR]

Distinct naphthenic acid (NA) species were isolated from oil sands process water (OSPW) into 20 fractions via silver-ion solid phase extraction, prior to treatment using potassium ferrate(VI). Untreated and treated fractions F1–F20 were characterized using ultra performance liquid chromatography traveling-wave ion mobility time-of-flight mass spectrometry to identify classical NAs (aliphatic O 2 –NAs mainly found in fractions F1–F4), aromatic NAs (aromatic O 2 –NAs in F6–F9), oxidized NAs (O 3 –, O 4 –, and O 5 –NAs in F14–F17), and sulfur-containing NAs (F16–F19). The Fe(VI) oxidation reactivity of individual NA species was studied with minimized confounding effects from the complicated OSPW matrix. Aliphatic and aromatic O 2 –NAs were found to have different reactivity towards Fe(VI) oxidation, with removals ranging from <50% up to 90% at 200 mg/L ferrate dose. The O 3 –NAs and O 4 –NAs from raw OSPW were recalcitrant species with slight degradation under Fe(VI) oxidation conditions. The Fe(VI) oxidation of O 2 –NAs generated new O 3 –NAs as byproducts or intermediate byproducts which finally resulted in more oxygen-rich O x –NAs as the final byproducts depending on the Fe(VI) doses. Besides the obtained knowledge on chemical reactivity, current methodology (i.e., treatment of Ag-ion fractions of OSPW versus raw OSPW) could be applied to evaluate other treatment approaches as well as toxicity of distinct NA species for environmental applications. Unlabelled Image • The Ag-ion SPE allowed a good separation of OSPW into 20 fractions. • Fe(VI) reactivity of isolated NA species was studied for the first time. • Fe(VI) oxidation removed O 2 –NAs favorably rather than other oxidized NAs. • Fe(VI) treatment could oxidize O 2 –NAs to generate O 4 –NAs directly. [ABSTRACT FROM AUTHOR]

• The dominant radical scavengers during UV/H 2 O 2 and UV/Cl were identified. • The effect of TOC on UV/H 2 O 2 vs. UV/Cl varied with micropollutant type and pH. • pH-TOC regions where either UV/H 2 O 2 or UV/Cl was more efficient were identified. UV/Cl and UV/H 2 O 2 are advanced oxidation processes (AOPs) used for drinking water treatment and water reuse. This work explored the hypothesis that UV/Cl becomes more competitive to UV/H 2 O 2 at neutral-to-high pH as the concentration of total organic carbon (TOC) increases. Lab experiments and kinetic modelling were used to compare initial pseudo first-order contaminant decay rate coefficients between the AOPs at various pH and TOC conditions. The relative effect of increasing TOC concentrations on UV/Cl vs. UV/H 2 O 2 depended on the pH, contaminant, and organic matter reactivity towards radicals. For example, while the reaction rate coefficients during both AOPs generally decreased with increasing TOC, the UV/Cl reaction rate coefficients for the solely •OH-reactive sucralose decreased 41–138% less than the UV/H 2 O 2 coefficients as the TOC concentration was increased from 0 to 5 mg-C L−1. However, UV/Cl was more affected than UV/H 2 O 2 when targeting caffeine (a contaminant reactive to chlorine radicals). The data were used to define TOC-pH conditions for which either AOP would be more energy-efficient, under a set of standard conditions. The results suggest that UV/Cl may be competitive to UV/H 2 O 2 under a wider range of treatment scenarios than has been conventionally thought based on tests in pure water. [Display omitted] [ABSTRACT FROM AUTHOR]

This work investigated the oxidative transformation of the organic species in oil sands process-affected water (OSPW) using Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) and ultra-performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) in both negative and positive electrospray ionization (ESI) modes. This is the first time to apply FTICR-MS to investigate species transformation in OSPW treatments by ferrate (VI), UV/H 2 O 2 , and molecular ozone, and also this is the first preliminary study to use positive ESI to investigate organic species in addition to naphthenic acids (NAs) in these treatment processes. The oxidation processes with potassium ferrate (VI), UV/H 2 O 2 , and ozone transformed the distribution profiles of O x , O x S y , and O x N y organic fractions (i.e., species containing oxygen, sulfur, and nitrogen, with x, y specifying the oxygen number and sulfur/nitrogen number, respectively), with O x S y distribution profiles showing the most sensitive responses to the oxidation extent and can be used as a signature fraction to evaluate the oxidation effectiveness. Negative mode UPLC-TOF-MS confirmed the transformation pattern of O x species observed with FTICR-MS, but positive mode UPLC-TOF-MS results showed severe discrepancies with FTICR-MS results and should be subjected for future further investigation, regarding the relatively low mass resolution of UPLC-TOF-MS. The investigation of the transformation patterns of different organic species using two ionization modes was a preliminary study to enhance the understanding of the efficiency, selectivity, and mechanism of different oxidation processes in OSPW remediation for both NAs and non-NA species. [ABSTRACT FROM AUTHOR]

The efficiency of three different oxidation processes, UV/H 2 O 2 oxidation, ferrate(VI) oxidation, and ozonation with and without hydroxyl radical ( OH) scavenger tert-butyl alcohol (TBA) on the removal of organic compounds from oil sands process-affected water (OSPW) was investigated and compared. The removal of aromatics and naphthenic acids (NAs) was explored by synchronous fluorescence spectra (SFS), ion mobility spectra (IMS), proton and carbon nuclear magnetic resonance ( 1 H and 13 C NMR), and ultra-performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC TOF-MS). UV/H 2 O 2 oxidation occurred through radical reaction and photolysis, transforming one-ring, two-ring, and three-ring fluorescing aromatics simultaneously and achieving 42.4% of classical NAs removal at 2.0 mM H 2 O 2 and 950 mJ/cm 2 UV dose provided with medium pressure mercury lamp. Ferrate(VI) oxidation exhibited high selectivity, preferentially removing two-ring and three-ring fluorescing aromatics, sulfur-containing NAs (NAs + S), and NAs with high carbon and high hydrogen deficiency. At 2.0 mM Fe(VI), 46.7% of classical NAs was removed. Ozonation achieved almost complete removal of fluorescing aromatics, NAs + S, and classical NAs (NAs with two oxygen atoms) at the dose of 2.0 mM O 3 . Both molecular ozone reaction and OH reaction were important pathways in transforming the organics in OSPW as supported by ozonation performance with and without TBA. 1 H NMR analyses further confirmed the removal of aromatics and NAs both qualitatively and quantitatively. All the three oxidation processes reduced the acute toxicity towards Vibrio fischeri and on goldfish primary kidney macrophages (PKMs), with ozonation being the most efficient. [ABSTRACT FROM AUTHOR]

Coal plays a vital role in the socio-economic development of China. Yet, the spatial mismatch between production centers (inland Northwest) and consumption centers (coastal region) within China fostered the emergence of dedicated coal transport corridors with limited alternatives. Serious problems of energy shortage and power rationing have already affected southeastern China. At the same time, enormous interregional coal transfers face a lack of transport capacity along the transport system. Based on first-hand statistics, a disaggregated analysis of coal distribution patterns since the late 1970s provides novel evidences about the local effects of macroscopic trends, such as the shift from dominant exports to dominant imports in terms of changing traffic concentration levels and distribution patterns among routes and ports. The spatial evolution of coal distribution is also discussed in terms of related industry linkages and local influences, coal trade policies and market pricing, port system evolution, and transport network planning. The paper also discusses possible improvements of the current situation through enhancing multimodal transport based on a review of current policies. [ABSTRACT FROM AUTHOR]

Abstract: A three-component reaction based on trapping of ammonium ylides with formaldehyde was first reported. This reaction offers a new strategy for the synthesis of α-aryl serine derivatives and can be extended to the preparation of α-aryl threonine derivatives. Synthetic application of the three component reaction for the preparation of hydroquinoxaline derivative was also demonstrated. [Copyright &y& Elsevier]

Abstract: Planned as Shanghai’s new port, Yangshan is currently expanding its roles as transhipment hub and integrated logistics/industrial center in the Asia–Pacific region. This paper examines the impact of the emergence of Yangshan on the spatial pattern of the Yangtze River Delta since the 1970s, with reference to existing port system spatial evolutionary models. While this emergence confirms the trend of offshore hub development and regionalization processes observed in other regions, we also discuss noticeable deviations due to territorial and governance issues. Strong national policies favoring Shanghai’s vicinity rather than Ningbo as well as the growth of Yangshan beyond sole transhipment functions all contribute to Shanghai’s transformation into a global city. [Copyright &y& Elsevier]

Abstract: Port system is a research focus of transport geography, and most studies believe carriers are important factors in the development and concentration of the port system. Since the 1990s, carriers have played an important role in organizing the global shipping network and reorganizing the port system. But there isn’t a perfect method to evaluate carriers’ influence and the roles of each port in the maritime shipping networks. In this paper, we use the monthly schedule table of international carriers to describe and model the spatial pattern of the global shipping network and identify its hub-and-spoke system. The result shows that a hierarchical structure exists in the global shipping network. The North Hemisphere, especially the East Asia and the Southeast Asia, is a dominant region of the worldwide shipping network. East Asia, Southeast Asia, Northeast Europe, and East coast of the USA are the concentration regions of worldwide shipping lines. The ports of Hong Kong, Singapore, Shenzhen, Shanghai, and Kaohsiung etc have advanced capacity for maritime shipping and high potentials for being hub ports in the global shipping network. Today, the worldwide shipping network is transforming from the multi-port calling system to 44 regional hub-and-spoke systems. Meanwhile, the sub-networks with hub ports of Antwerp, Singapore, and Hong Kong have become the most important ones and dominate the whole global shipping network. [Copyright &y& Elsevier]

• Binding interactions between HA and TET inhibited the degradation of TET. • The nature of sites engaged in the HA/TET binding were identified by FTIR and 1H NMR analyses. • Degradation priority was established as free TET>bound TET>HA in UV/PMS, UV/H 2 O 2 and UV systems. • •OH/•SO 4 −, PMS and UV had varying roles in UV/PS, UV/PMS and UV/H 2 O 2 processes. The binding between dissolved organic matter (DOM) and micro-pollutants (MPs) results in significant impacts on their migration, transformation and degradation. However, the role of the DOM/MP binding on their oxidative transformation remains poorly studied. The binding of MPs by DOM, in combination with DOM's roles as a photosensitizer and/or a competitor for free radicals, needs to be considered in the context of understanding the DOM's impacts on the oxidative degradation of MPs. This study aims to explore this aspect of DOM/MP interactions based on the quantitation of humic acid (HA) and tetracycline (TET) complexation and its role in TET removal. This study also compared the degradation of free TET versus that bound in HA-TET complexes in different oxidation processes. Fourier transform infrared (FTIR) data show that the carboxyl and phenolic hydroxyl groups in HA are the main binding sites of TET, while nuclear magnetic resonance (NMR) analysis shows the binding of TET engages its -N(CH 3) 2 groups, and two-dimensional correlation spectroscopy (2D-COS) data show that the carboxyl groups in DOM are sensitive than phenolic groups in the binding of TET. The difference between the degradation rates (Δk obs) of the free and bound TET decreased with the increase of ionic strength using sodium nitrate, but increased with the introduction of Ca2+ and Mg2+ due to the formation of TET-Ca2+/Mg2+ complexes. Quenching experiments showed that the free radicals (•OH and •SO 4 −), PMS oxidant and UV light were the main contributors to the TET degradation in UV/PS, UV/PMS and UV/H 2 O 2 processes, respectively. In-situ fluorescence time scanning and differential absorbance spectra showed that free TET was preferentially oxidized over the bound TET in all the tested treatments except UV/PS. These results provide new insights into the role of DOM/MP complexation in the degradation of MPs in natural and engineered systems. [Display omitted] [ABSTRACT FROM AUTHOR]

• CHA degradation was mainly attributed to OH radical attack. • Dividing the chlorine dose into five separated doses increased the removal rate. • Different by-products were identified including two chlorine-containing by-products. • The reaction pathway for CHA degradation during UV/Chlorine treatment was proposed. Degradation kinetics, by-products identification and pathways of a model naphthenic acid, cyclohexanecarboxylic acid (CHA), by the UV/Chlorine process were investigated in this study. Mathematical modeling indicated that the initial CHA decay rate increased rapidly with the chlorine dose when the chlorine dose was lower than 45 mg/L and decreased with further chlorine dose increases. Increasing the chlorine dose from 400 to 800 mg/L resulted in a steady increase in the total removal of CHA after 60 min of UV photolysis. By dividing the 700 mg/L chlorine dose into five separated doses (140 mg/L each) added at 10 min intervals, the total CHA removal increased from 72% to 91%. This implies that the ideal condition of the UV/Chlorine process in degrading CHA is to add chlorine continuously at a constant rate to compensate any chlorine consumption to reduce the radical scavenging effect. It was found that the CHA decay was mainly attributed to the hydroxyl radical (OH) attack and the reactive chlorine species (RCS) contribution was relatively small. Various by-products, including the mono-chlorinated and di-chlorinated by-products, were identified and the reaction pathway for CHA degradation during UV/Chlorine treatment was proposed. [ABSTRACT FROM AUTHOR]

Drinking water treatment using UV/H 2 O 2 advanced oxidation typically results in residual H 2 O 2 that requires quenching to minimize its interference with downstream processes. Chemical quenching using chlorine or bisulfite are options, but there is some uncertainty in the literature about the kinetics of the bisulfite reaction, with some reports quoting the reaction as fast, and others as slow. Part of the contradictory information may be due to interference in H 2 O 2 analysis by bisulfite. An analytical method was developed to avoid this interference, in which monochloramine first selectively quenched bisulfite, and then H 2 O 2 was measured spectrometrically using titanium(IV) oxysulfate for color development. The confirmatory experiments suggested that the bisulfite reaction with H 2 O 2 is actually relatively slow, with a half-life in the order of hours to days depending on the pH and the reagent concentrations. As a result, within the typical pH range of drinking water treatment (e.g., 6–9), chlorine is preferred over bisulfite as the H 2 O 2 quenching agent on the basis of reaction kinetics. However, a decrease in pH will lead to an increase in the bisulfite-H 2 O 2 reaction rate along with a decrease in the Cl 2 –H 2 O 2 reaction rate, such that at pH < 5.7 bisulfite is the faster reagent. Both bisulfite and chlorine were observed to react with H 2 O 2 following a stoichiometric ratio of 1:1 in the natural water matrix tested. Image 1 • Bisulfite quenches H 2 O 2 at too slow a rate to serve as a quenching agent. • Cl 2 quenches H 2 O 2 quickly at neutral and basic pH, but not instantaneously. • A modified titanium(IV) method was developed to quantify H 2 O 2. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel method for efficient and stable laser cutting of silicon by optimizing focusing condition is proposed. • Effect of focusing condition on laser underwater cutting property is discussed. • Effect of focusing condition on bubble behaviors is studied based on time-resolved imaging system. • Mechanism of focusing condition on transmission efficiency of laser is analyzed. In this paper, the effect and mechanism of how varying focusing conditions would affect the machining quality of microgrooves and bubble behaviors (cavitation bubbles (CB) and persistent bubbles (PB)) in liquid-assisted femtosecond laser micro-grooving of silicon wafer were investigated. Firstly, the width and depth of the microgroove machined under negative defocusing condition (NDC) were considerably uniform, which showed an increase by 100 % and 125 % compared with that machined under positive defocusing condition (PDC). Secondly, the temporal evolution images of CB were captured by a time-resolved shadowgraph imaging system. Compared with PDC, the radius and lifetime of CB induced under NDC increased by 71 % and 100 %, and the time evolution curve of the radius of CB exhibited a high consistence with the Rayleigh distribution, while that induced under PDC fluctuated irregularly. Thirdly, the PB induced under NDC showed a backward flush and contributed to the formation of tendentious liquid flow, while that induced under PDC occupied the laser transmission path and caused disturbances on subsequent laser pulses. Finally, the differences in laser transmission mechanism under both the negative and positive defocusing conditions were discussed and the NDC was confirmed as the stable and efficient processing method. Through the comprehensive study of the bubble behaviors, the correlation between focusing conditions and machining quality of liquid-assisted laser cutting was established. [ABSTRACT FROM AUTHOR]

The machining of sapphire, a hard and transparent material, is of significant interest in various industries due to its exceptional properties. Traditional machining methods for sapphire suffer from drawbacks such as low efficiency and poor processing quality. Laser machining, particularly using ultraviolet (UV) nanosecond lasers, has emerged as a promising alternative for machining sapphire. In this article, we explored the use of reflective target materials to enhance laser energy absorption during the machining of sapphire. The effect of different reflective target materials, including aluminum and silicon, on the laser machining process was examined. Parametric calculations and finite-difference time-domain (FDTD) simulation were performed to evaluate the laser intensity at the top surface of sapphire when a reflective target material was employed. The results demonstrated that the use of reflective target materials leads to increased laser intensity due to the interference of incident and reflected laser beams, thus improving material removal efficiency. Moreover, experimental observations confirmed the effectiveness of using reflective target materials in enhancing the machined depth of sapphire. For example, the machined depth of 21.6 µm with a power density of 1.7 × 108 W/cm2 increased to 23.3 µm and 26.5 µm by using silicon and aluminum target materials. It is found that using aluminum target led to higher machined depth than silicon owing to its higher reflectivity. • Employing reflective target materials to enhance material removal efficiency in the ultraviolet (UV) nanosecond laser machining of sapphire. • Understanding the relationship between laser intensity and the refractive indices of the target material and sapphire substrate. • Evaluating the laser intensity at the top surface of sapphire by using parametric calculations, finite-difference time-domain (FDTD) simulations, and experimental observations. [ABSTRACT FROM AUTHOR]

An efficient rhodium(II)-catalyzed three-component reaction of 3-diazooxindoles, indoles and formalin was reported. With this transformation, a series of 3-(hydroxymethyl)-3-indol-3′-yloxindoles were easily afforded in good to excellent yields. The resulted 3-(hydroxymethyl)-3-indol-3′-yloxindole could be easily converted to the key intermediate for the total synthesis of gliocladin C. [ABSTRACT FROM AUTHOR]

• Peracetic acid (PAA) may exert chlorine demand in drinking water. • PAA's chlorine demand is mostly by H 2 O 2 from PAA hydrolysis, especially at pH ≥ 8. • Direct PAA reaction with chlorine is slow and the reaction rate is pH dependent. • In most cases, chlorine demand by PAA is < 20% of initial chlorine over 7 days. Peracetic acid (PAA) may be used in drinking water treatment for pre-oxidation and mussel control at the intake. PAA may exert a downstream chlorine demand, but full details of this reaction have not been reported. There are three possible mechanisms of this demand: (1) PAA may react directly with chlorine; (2) PAA exists in equilibrium with hydrogen peroxide, which is known to react with chlorine; and (3) as H 2 O 2 reacts with chlorine, PAA will hydrolyze to form more H 2 O 2 to re-establish PAA/H 2 O 2 equilibrium, thereby serving as an indirect reservoir of chlorine demand. While the H 2 O 2 reaction with chlorine is well known, the other mechanisms of possible PAA-induced chlorine demand have not previously been investigated. The observed molar stoichiometric ratio of PAA to free chlorine (n) for the presumed direct PAA + free chlorine reaction was determined to be approximately 2, and the corresponding observed reaction rate coefficients at pH 6, 7, 8, and 9 were 2.76, 3.14, 1.61, 10.1 M−n·s−1, respectively (at 25 °C). With these estimated values, a kinetic model was built to predict the chlorine demand by PAA. The results suggest that chlorine demand from PAA is likely to be negligible over the course of several days (e.g., < 20% chlorine loss) for most conditions except for high pH (e.g., >8) and high PAA:Cl 2 molar ratios (e.g., >2:1). [ABSTRACT FROM AUTHOR]

This work reports the monitoring and assessment of naphthenic acids (NAs) in oil sands process-affected water (OSPW), Pleistocene channel aquifer groundwater (PLCA), and oil sands basal aquifer groundwater (OSBA) from an active oil sands development in Alberta, Canada, using ultra performance liquid chromatography time-of-flight mass spectrometry (UPLC-TOF-MS) analysis with internal standard (ISTD) and external standard (ESTD) calibration methods and Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) for compositional analysis. PLCA was collected at 45–51 m depth and OSBA was collected at 67–144 m depth. Results of O x −NA concentrations follow an order as OSPW > OSBA > PLCA, indicating that occurrences of NAs in OSBA were likely related to natural bitumen deposits instead of OSPW. Liquid-liquid extraction (LLE) was applied to avoid the matrix effect for the ESTD method. Reduced LLE efficiency accounted for the divergence of the ISTD and ESTD calibrated results for oxidized NAs. Principle component analysis results of O 2 and O 4 species could be employed for differentiation of water types, while classical NAs with C13−15 and Z (-4)−(-6) and aromatic O 2 −NAs with C16−18 and Z (-14)−(-16) could be measured as marker compounds to characterize water sources and potential temporal variations of samples, respectively. FTICR-MS results revealed that compositions of NA species varied greatly among OSPW, PLCA, and OSBA, because of NA transfer and transformation processes. This work contributed to the understanding of the concentration and composition of NAs in various types of water, and provided a useful combination of analytical and statistical tools for monitoring studies, in support of future safe discharge of treated OSPW. [ABSTRACT FROM AUTHOR]

As an important link in the global network of value chains and supply chains, the evolution of the function of modern ports depends on changes in the distribution of freight volume and shipping routes among ports, along with changes in terms of interdependence and spatial differentiation between various port and shipping service enterprises (PSSEs), such as shipping companies, multimodal transport providers, freight forwarders, and shipping financial institutions. On the basis of defining the connotation of PSSEs, this study takes the Yangtze River Delta as a research case and uses the three-axis rotation method, standard deviational ellipse, and spatial interpolation simulation to analyse the distribution pattern and evolution characteristics of PSSEs from 2002 to 2019. The discrete regression model was used to explore the main factors affecting the location choice of various PSSEs. The characteristics of the spatial and temporal evolution of PSSEs in the Yangtze River Delta are as follows: (1) The structure of the PSSEs in the Yangtze River Delta is in the process of continuous upgrading. It presents a 'medium-high-low' pattern in which medium-end enterprises are dominant, and high-end enterprises are increasing rapidly. (2) The spatial distribution of low- and high-end enterprises is concentrated, and medium-end enterprises are more dispersed. The distribution centre of medium- and low-end enterprises moves westward, while the distribution centre of high-end enterprises turns eastward. (3) The growth rates of medium- and high-end enterprises are much higher than those of low-end enterprises. The analysis of location factors based on the conditional logit model demonstrates that the factors affecting PSSEs are becoming increasingly complex. Besides the influence of traditional location factors such as the economy and transportation of the hinterland, they are also affected by emerging factors such as informatization and the level of financial development. Moreover, the impact of external factors, such as globalization, marketisation, and servitisation, is also rising significantly. [ABSTRACT FROM AUTHOR]

Emerging evidence and clinical case reports have observed a risk of cytotoxic effects of triptolide in patients. We aimed to investigate the triptolide-induced toxicity in mouse inner ear stem cells. The utricular sensory epithelium from adult BALB/C6 mice was used for the isolation of inner ear stem cells. Sphere formation assay was applied to examine the stemness of the cells. Cell count kit-8 and Bromodeoxyuridine assays were employed to detect the cell proliferation ability. Cell apoptosis was measured with Annexin V-FITC & propidium iodide Apoptosis kit. The relative expression levels of gamma H2A histone family member X (γH2AX), tumor suppressor p53-binding protein 1 (53BP1) and optic atrophy 1 (OPA-1) were measured by Western Blot. Mitochondrial function was analyzed by the MitoGreen green-fluorescent mitochondrial dye kit. Triptolide significantly inhibited the cell viability and proliferation and suppressed the capability of sphere formation. Furthermore, triptolide induced apoptosis as indicated by increased expression of DNA damage repair markers γH2AX and 53BP1. Moreover, triptolide influenced the function of mitochondria by inducing the cleavage of OPA-1. Our work clarifies the toxicity of triptolide in mouse inner ear stem cells, which provides clues of the toxicology mechanism for future studies and basis for clinical use. • Triptolide significantly inhibits the cell viability and proliferation and suppresses the capability of sphere formation. • Triptolide induces apoptosis as indicated by increased expression of DNA damage repair markers γH2AX and 53BP1. • Triptolide influences the function of mitochondria by inducing the cleavage of OPA-1. [ABSTRACT FROM AUTHOR]