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In this paper, we prove several conjectures raised by Zhi-Wei Sun on determinants and permanents by the eigenvectors-eigenvalues identity recently highlighted by Denton, Parke, Tao and Zhang. [ABSTRACT FROM AUTHOR]

In this note we study the Mahler measures of reciprocal polynomials P k = x + 1 / x + y + 1 / y + k for k = 4 ± 4 2 . We prove identities relating the Mahler measure of P 4 ± 4 2 to special values of the L -functions of weight 2 cusp forms of level 64. We also express the Beilinson regulator which is a 2 × 2 determinant of Mahler measures as special value of L -function of the elliptic curve defined by P 4 + 4 2 = 0. [ABSTRACT FROM AUTHOR]

In this paper, we study certain determinants involving tangent functions. We prove that for any odd number n ⩾ 3 and s ∈ Z + , the determinant D (n , s) = det (tan s ⁡ π j + k n) 1 ⩽ j , k ⩽ n − 1 ∈ n n − 2 Z . In the special case s = 2, we confirm a conjecture raised by Zhi-Wei Sun in 2019. [ABSTRACT FROM AUTHOR]

We study two determinants involving tangent and cotangent functions and prove two conjectures made by Zhi-Wei Sun in 2019. Both determinants are divisible by the first factor of the class numbers of associated cyclotomic fields. [ABSTRACT FROM AUTHOR]

Fly ash (FA) derived from municipal solid waste incineration (MSWI) requires safe handling before landfilling due to its extremely high salt content and the risk of leaching heavy metals (HMs) under acidic conditions. Herein, aimed at improving the acid stability of dithiocarbamates, a cost-effective oligomeric dithiocarbamate (ODTC) was developed to stabilize HMs from carbonated MSWI-FA. Spiking of 3.6 wt% ODTC reduced the HM leaching below landfill standards in China, even across the pH range of 2.0–13.0 or 8-week exposure to the natural environment. Stabilization decreased the acid-soluble/exchangeable fractions of Cd, Pb, and Zn from 22.2%, 4.49%, and 21.9% to 0.14%, 0.11%, and 12.2%, respectively, resulting in safe levels for Pb and Cd with risk assessments. Compared to DDTC and SDD, ODTC exhibited higher stability under acidic conditions after chelation with the HMs, minimized the risk of HM leaching, and significantly reduced stabilization costs. In-depth studies proved that the stabilization mechanism involved the ability of ODTC to chelate HMs strongly and form acid-resistant ODTC-HM complexes, agglomeration of the MSWI-FA grains to encapsulate the ODTC-HM complexes, transformations of the HMs from acid-soluble species to stable oxidizable and residual species, and specifically ODTC reducing high-valent Pb to more stable Pb(II) species. [Display omitted] • Acid-resistant ODTC was innovatively synthesized for MSWI-FA stabilization. • Up to 99.8% of Cd and Pb were transformed into stable forms resisting leaching. • ODTC minimized the environmental risks of MSWI-FA even at extreme pHs of 1.0 and 13.5. • Stabilization with ODTC substantially reduced costs outshining other stabilizers. • Mechanistic insight into MSWI-FA stabilization by ODTC was thoroughly conducted. [ABSTRACT FROM AUTHOR]

Background: Non-alcoholic fatty liver disease (NAFLD) has become a global epidemic disease. Its incidence is associated with type 2 diabetes mellitus (T2DM). Presently, there is no approved pharmacological agents specially developed for NAFLD. One promising disease-modifying strategy is the transplantation of stem cells to promote metabolic regulation and repair of injury. Method: In this study, a T2DM model was established through 28-week high-fat diet (HFD) feeding resulting in T2DM-associated NAFLD, followed by the injection of bone marrow mesenchymal stem cells (BMSCs). The morphology, function, and transfer of hepatocyte mitochondria were evaluated in both vivo and in vitro. Results: BMSC implantation resulted in the considerable recovery of increasing weight, HFD-induced steatosis, liver function, and disordered glucose and lipid metabolism. The treatment with BMSC transplantation was accompanied by reduced fat accumulation. Moreover, mitochondrial transfer was observed in both vivo and vitro studies. And the mitochondria-recipient steatotic cells exhibited significantly enhanced OXPHOS activity, ATP production, and mitochondrial membrane potential, and reduced reactive oxygen species levels, which were not achieved by the blocking of mitochondrial transfer. Conclusion: Mitochondrial transfer from BMSCs is a feasible process to combat NAFLD via rescuing dysfunction mitochondria, and has a promising therapeutic effect on metabolism-related diseases. [ABSTRACT FROM AUTHOR]

The Tibetan Plateau, known as the world's "Third Pole" due to its high altitude, is experiencing rapid, intense climate change, similar to and even far more than that occurring in the Arctic and Antarctic. Scientific data sharing is very important to address the challenges of better understanding the unprecedented changes in the Third Pole and their impacts on the global environment and humans. The National Tibetan Plateau Data Center (TPDC, http://data.tpdc.ac.cn) is one of the first 20 national data centers endorsed by the Ministry of Science and Technology of China in 2019 and features the most complete scientific data for the Tibetan Plateau and surrounding regions, hosting more than 3,500 datasets in diverse disciplines. Fifty datasets featuring high-mountain observations, land surface parameters, near-surface atmospheric forcing, cryospheric variables, and high-profile article-associated data over the Tibetan Plateau, frequently being used to quantify the hydrological cycle and water security, early warning assessments of glacier avalanche disasters, and other geoscience studies on the Tibetan Plateau, are highlighted in this manuscript. The TPDC provides a cloud-based platform with integrated online data acquisition, quality control, analysis, and visualization capability to maximize the efficiency of data sharing. The TPDC shifts from the traditional centralized architecture to a decentralized deployment to effectively connect Third Pole–related data from other domestic and international data sources. As an embryo of data sharing and management over extreme environment in the upcoming "big data" era, the TPDC is dedicated to filling the gaps in data collection, discovery, and consumption in the Third Pole, facilitating scientific activities, particularly those featuring extensive interdisciplinary data use. [ABSTRACT FROM AUTHOR]

Snow cover is of great significance for many applications. However, automatic extraction of snow cover from high spatial resolution remote sensing (HSRRS) imagery remains challenging, owing to its multiscale characteristics, similarities to clouds, and occlusion by the shadows of mountains and clouds. Deep convolutional neural networks for semantic segmentation are the most popular approach to automatic map generation, but they require huge computing time and resources, as well as a large dataset of pixel-wise annotated HSRRS images, which precludes the application of many superior models. In this study, these limitations are overcome by using a sequence of transfer learning steps. The method starts with a modified aligned 'Xception' model pre-trained for object classification on ImageNet. Subsequently, a 'DeepLab version three plus' (DeepLabv3+) model is trained using a large dataset of Landsat images and corresponding snow cover products. Finally, a second transfer learning step is employed to fine-tune the model on the small dataset of GaoFen-2, the highest resolution HSRRS satellite in China. Experiments demonstrate the feasibility and effectiveness of this framework for automatic snow cover extraction. [ABSTRACT FROM AUTHOR]

This paper gives some new families of non-congruent numbers with arbitrarily many prime divisors. The main idea is based on Monsky's formula for the 2-Selmer rank of congruent elliptic curves. [ABSTRACT FROM AUTHOR]

Abstract We construct several new families of non-congruent numbers with arbitrarily many prime factors congruent to 3 modulo 8. Our results generalize the work of Reinholz, Spearman and Yang [14]. Our methods are based on Monsky's formula on the 2-Selmer rank of the congruent elliptic curve and the recent results by Tian, Yuan and Zhang on the congruent number problem. [ABSTRACT FROM AUTHOR]

In this paper, we study the Galois action on the extended Bloch groups of biquadratic and dihedral number fields. We prove that if F is a biquadratic number field, then the index Q 2 ( F ) in Browkin and Gangl's formulas on the Brauer–Kuroda relation can only be 1 or 2. This is exactly what Browkin and Gangl predicted in their paper. Moreover we give the explicit criteria for Q 2 ( F ) = 1 or 2 in terms of the Tate kernels. We also prove that Q 2 ( F ) = 1 or p for any dihedral extension F / Q whose Galois group is the dihedral group of order 2 p , where p is an odd prime. [ABSTRACT FROM AUTHOR]

Teachers' conceptions of assessment are a significant indicator of teacher assessment literacy. This study contextualized pre-service teachers' conceptions of assessment in Chinese second language education. An exploratory factor analysis generated eight first-order factors and the following confirmatory factor analysis found a hierarchical model, reflecting a noticeable influence of prior learning experiences and official assessment regimes on conceptions. A follow-up latent profile analysis showed three profiles. Improvement-oriented was the most prevalent profile, but more than 40% of the participants were categorized as negative. The study substantiated the need to develop an integrative and balanced understanding of assessment in teacher education to prepare pre-service teachers for teaching in international contexts. [ABSTRACT FROM AUTHOR]

We recently demonstrated common oxidants simply coupled with ZVI to continuously drive the accelerated Fe 0 corrosion and hence achieve fast and very efficient removal of heavy metals and metalloids from groundwater. In this study, we aimed first to answer a basic question of the oxidant dosage theoretically required to sequester a certain amount of selenite. The specific ratio of oxidant dosage to Se(IV) removal, which reflected the theoretically minimal oxidant dosage required to sequester one mole of Se(IV), was almost independent of the initial Se(IV) concentration but significantly affected by the difference in oxidant species. To sequester one mole of Se(IV), the minimum dosage of the required oxidant was calculated to be 3.94–4.09 for NaClO, 3.90–4.33 for H 2 O 2 , and 3.29–3.54 for KMnO 4 , respectively. Simultaneous aeration increased the removal efficiency of Se(IV) and substantially reduced the required dosage of oxidants. To form a strong contrast with very limited Se(IV) removal by ZVI alone, the coupling of NaClO and H 2 O 2 into the ZVI system remarkably enhanced the performance of Se(IV) removal during the long term fixed-bed experiments with a real groundwater background. The ZVI columns coupled by NaClO and H 2 O 2 steadily treated 10,000 volumes (BV) of real groundwater. X-ray adsorption near edge structure (XANES) demonstrated that more than 85% of the selenium was reduced to Se 0 and Se 2− , with Se 0 as the dominant selenium species sequestered in the solid phase. Synchrotron-based scanning transmission soft X-ray microscopy (STXM) explicitly revealed the ubiquitous spatial distribution of selenium in the corrosion products and hence demonstrated a high accessibility of these corrosion products to selenite. [ABSTRACT FROM AUTHOR]

Bioaccumulation of perylene in Escherichia coli and Staphylococcus aureus was visualized and quantified in real time with high sensitivity at high temporal resolution. For the first time, single-molecule fluorescence microscopy (SMFM) with a microfluidic flow chamber and temperature control has enabled us to record the dynamic process of perylene bioaccumulation in single bacterial cells and examine the cell-to-cell heterogeneity. Although with identical genomes, individual E. coli cells exhibited a high degree of heterogeneity in perylene accumulation dynamics, as shown by the high coefficient of variation (C.V = 1.40). This remarkable heterogeneity was exhibited only in live E. coli cells. However, the bioaccumulation of perylene in live and dead S. aureus cells showed similar patterns with a low degree of heterogeneity (C.V = 0.36). We found that the efflux systems associated with Tol C played an essential role in perylene bioaccumulation in E. coli, which caused a significantly lower accumulation and a high cell-to-cell heterogeneity. In comparison with E. coli, the Gram-positive bacteria S. aureus lacked an efficient efflux system against perylene. Therefore, perylene bioaccumulation in S. aureus was simply a passive diffusion process across the cell membrane. [ABSTRACT FROM AUTHOR]

The pH-dependent leaching of antimony (Sb) and arsenic (As) from three typical Sb-bearing ores (Banxi, Muli and Tongkeng Antimony Mine) in China was assessed using a pH-static leaching experiment. The pH changes of the leached solutions and pH-dependent leaching of Sb and As occurred in different ways. For the Banxi and Muli Sb ores, alkaline conditions were more favorable for the release of Sb compared to neutral and acidic conditions, but the reverse was true for the pH-dependent release of As. For the Tongkeng Sb ore, unlike the previous two Sb-bearing ores, acidic conditions were more favorable for Sb release than neutral and alkaline conditions. The ores with lower Sb and As contents released higher percentages of their Sb and As after 16 day leaching, suggesting that they are the largest potential sources of pollution. This work may provide key information on the geochemistry of Sb and As in the weathering zone. [ABSTRACT FROM AUTHOR]

Corex Periplocae (the root of Periploca sepium Bge) has been widely used in clinics. Periplocin, as one of the components of cardiac glycosides in Corex Periplocae , easily triggers cardiotoxicity when used improperly. To evaluate the toxicity of Periplocin, we used UPLC-Q-TOF/MS to investigate metabolic profiles on neonatal rat cardiomyocytes exposed to high and low doses of Periplocin (0.2 mmol/L, 0.4 mmol/L). Finally, we identified 11 biomarkers associated with toxicity through multivariate statistical analysis. A “supervised” Support Vector Machine (SVM) study was used to optimize and verify the reliability of these biomarkers. In these biomarkers, all biomarkers, including carnitine, acetylcarnitine, lysoPC(16:0), proline, glutamic acid, pyroglutamic acid, leucine, pantothenic acid, tryptophan, indoleacrylic acid and citric acid, revealed a downward trend with the increase of dosage. Moreover, pathway analysis showed that these metabolites were associated with amino acid metabolism, energy metabolism and sphingolipid metabolism, which contributes to a further understanding of the toxicity mechanism of Corex Periplocae and its clinical safety. Additionally, we demonstrate that an UPLC-Q-TOF/MS-based metabolomic approach is a powerful tool and provides a promising approach for assessing the toxicity of traditional Chinese medicine and drug safety screening. [ABSTRACT FROM AUTHOR]

This study, for the first time, demonstrated a continuously accelerated Fe 0 corrosion driven by common oxidants (i.e., NaClO, KMnO 4 or H 2 O 2 ) and thereby the rapid and efficient removal of heavy metals (HMs) by zero-valent iron (ZVI) under the experimental conditions of jar tests and column running. ZVI simply coupled with NaClO, KMnO 4 or H 2 O 2 (0.5 mM) resulted in almost complete As(V) removal within only 10 min with 1000 μg/L of initial As(V) at initial pH of 7.5(±0.1) and liquid solid ratio of 200:1. Simultaneous removal of 200 μg/L of initial Cd(II) and Hg(II) to 2.4–4.4 μg/L for Cd(II) and to 4.0–5.0 μg/L for Hg(II) were achieved within 30 min. No deterioration of HM removal was observed during the ten recycles of jar tests. The ZVI columns activated by 0.1 mM of oxidants had stably treated 40,200 (NaClO), 20,295 (KMnO 4 ) and 40,200 (H 2 O 2 ) bed volumes (BV) of HM-contaminated drinking water, but with no any indication of As breakthrough (<10 μg/L) even at short empty bed contact time (EBCT) of 8.0 min. The high efficiency of HMs removal from both the jar tests and column running implied a continuous and stable activation (overcoming of iron passivation) of Fe 0 surface by the oxidants. Via the proper increase in oxidant dosing, the ZVI/oxidant combination was applicable to treat highly As(V)-contaminated wastewater. During Fe 0 surface corrosion accelerated by oxidants, a large amount of fresh and reactive iron oxides and oxyhydroxides were continuously generated, which were responsible for the rapid and efficient removal of HMs through multiple mechanisms including adsorption and co-precipitation. A steady state of Fe 0 surface activation and HM removal enabled this simply coupled system to remove HMs with high speed, efficiency and perdurability. [ABSTRACT FROM AUTHOR]

The surface passivation and the subsequent reduction of ZVI reactivity seriously restricted the application of zero-valent-iron (ZVI) for water remediation. This study comprehensively investigated the critical role of common oxidants, such as O 2 , H 2 O 2 , KMnO 4 and CrO 4 2− in activating the reactivity of ZVI surface and hence in facilitating nitrate reduction from the aqueous solution at non-acidic pH. Nitrate reduction by ZVI was negligible in the absence of O 2 at pH > 5. To the contrary, obvious reduction of nitrate was observed in the presence of O 2 , although with a clear trend of decreasing nitrate reduction with pH increase. KMnO 4 , H 2 O 2 , and CrO 4 2− were observed to strongly enhance the reactivity of ZVI. Dosing KMnO 4 and H 2 O 2 achieved 94% and 97% of nitrate reduction at pH 5.0, and 74% and 98% at pH 7.0. Five cycles of nitrate removal by the combined system of ZVI/oxidant/zeolite demonstrated the overcoming of the impedance of passivation layer, strongly facilitating the ultimate removal of nitrogen species from the aqueous solution. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we give an alternative proof of Berkovich and Jagy's genus identity and verify a series of conjectures raised by Cooper and Lam on the number of solutions of and two conjectures raised by Sun on the number of solutions of , . [Copyright &y& Elsevier]

A large amount of solid waste has been produced by the antimony smelting process in the “World Capital of Antimony”, Xikuangshan area in China. This study comprehensively investigated the physical and chemical characteristics of the various solid wastes, as well as the leaching behavior of the solid wastes, which included water-quenched slag, arsenic-alkali residue, desulfurized slag and blast furnace dust. These four types of waste were enriched in a variety of heavy metals and metalloids and more specifically with As and Sb levels up to 8.6 × 10 4 and 3.16 × 10 5 mg/kg, respectively, in arsenic-alkali residue. For desulfurized slag and water-quenched slag, the leaching concentration of Sb significantly exceeded the acceptable limits during the leaching tests using the toxicity characteristic leaching procedure and the synthetic precipitation leaching procedure. In addition, As leaching in arsenic-alkali residue was extraordinarily hazardous, being three orders of magnitude higher than the regulatory level of As. According to the results of the extraction tests, all the tested wastes were classified as hazardous waste. [ABSTRACT FROM AUTHOR]

A resurgent interest in anaerobic treatment of organic wastes intrigues the subsequent wastewater purification and nutrient recovery. This study investigated the feasibility of tubular ultrafiltration to treat anaerobically digested wastewater (AnDW) in the pilot-scale. Due to the gel-layer filtration mechanism, which primarily governed the AnDW wastewater passing through the membrane module, the change of operating pressure in the experimental conditions showed a minor effect on the permeate flux, while the cross-flow tangential velocity showed a significant effect on the permeate flux. A permeate flux on average of 22 l m−2 h−1was obtained when the feed superficial-velocity was up to 2 m s−1. The permeate flux decreased with increasing suspended solid concentration, implying a potential advantage of preliminary solid-liquid separation such as mechanical centrifugation. Irrespective of the arranged order of the sequential cleaning, the fouled membrane can be successfully cleaned using specific cleaning agents, which included a weak acid, a detergent, and an oxidant, respectively. A commercial detergent, namely KLD II, exhibited the greatest contribution to the flux recovery during the sequential cleaning. [ABSTRACT FROM PUBLISHER]

Abstract: As the largest plateau-type wetland in the world and the largest peat storage in China, Zoige wetland faces severe water decline, and consequently accelerated peat degradation and carbon emission. Here, a variety of characterization approaches, including elemental analysis, UV–vis spectra, FT-IR spectra, and solid state 13C NMR spectra were used to investigate the degradation and the structural shift of humic acids (HAs) in correspondence with serious water loss in Zoige peatland. Water loss derived from both natural slope and artificial drainage caused a substantial degradation of organic matter and HAs. Compared with the blocks immersed by free surface water, HAs extracted from the drier blocks had more pronounced signals of carboxyl and carbonyl groups, but carried lower content of methoxyl, carbohydrate, alcohol and ether groups. The total aliphatic carbon in HAs from natural-slope drier site decreased almost one half, but in the artificial-drained site, only slightly decreased. Correspondingly, the HA aromaticity substantially increased in the site undergoing the longer time of aerobic oxidation, whereas varied little in the site impacted by extensive water leaching. [Copyright &y& Elsevier]

Obtaining cost-effective iron (oxyhydr)oxide nanocrystallines is the essential prerequisite for their future extensive applications in environmental remediation, such as the removal of heavy metals from contaminated waters. Here, various phases of iron (oxyhydr)oxide nanocrystallines were simply synthesized from the phase-controlled transformation of amorphous hydrous ferric- or ferrous-oxide in thermal solution with a certain ethanol/water ratio and with the presence of oleic acid. According to this method, goethite nanorods in diameter of 3-4 nm, hematite nanocubes sized 20-30 nm, and magnetite nanoparticles in diameter of 6-7 nm were successfully obtained. The final products of this transformation can be conveniently controlled by adjusting the reaction parameters, such as pH, temperature, and ethanol/water ratio. Due to the enhanced specific surface area and probably the modifications of the surface structure of nanocrystallines, the as-synthesized goethite nanorods and magnetite nanoparticles demonstrated extremely strong As(III) affinity, with 5.8 and 54 times of As(III) adsorption, respectively, higher than the micron-sized relatives. The cost-effective feature of as-synthesized nanocrystallines and their remarkably enhanced affinity toward arsenic made them potentially applicable for the removal of arsenic and such like heavy metals from the contaminated environment. [ABSTRACT FROM AUTHOR]

Abstract: Antimony occurs widely in the environment as a result of natural processes and human activity. Although antimony is similar to arsenic in chemical properties and toxicity, and a pollutant of priority interest to the USEPA and the EU, its environmental behaviors, control techniques, and even solution chemistry, are yet barely touched. In this study, antimony removal from drinking water with coagulation–flocculation–sedimentation (CFS) is comprehensively investigated with respect to the dependence of both Sb(III) and Sb(V) removal on the initial contaminant-loading level, coagulant type and dosage, pH and interfering ions. The optimum pH for Sb(V) removal with ferric chloride (FC) was observed at pH 4.5–5.5, and continuously reduced with further pH increase. Over a broad pH range from 4.0 to 10.0, effective Sb(III) removal with FC was obtained. Contrary to the effective Sb removal with FC, the degree of both Sb(III) and Sb(V) removal with aluminum sulfate (AS) was very low, indicating the impracticability of AS application for antimony removal. The presence of phosphate and humic acid (HA) markedly impeded Sb(V) removal, while exhibited insignificant effect on Sb(III) removal. The effects of coagulant type, Sb species and pH are more pronounced than the effects of coagulant dose and initial pollutant concentration. After preliminarily excluding the possibility of precipitation and the predominance of coprecipitation, the adsorption mechanism is used to rationalize and simulate Sb/FC coagulation with good result by incorporating diffuse-layer model (DLM). [Copyright &y& Elsevier]

A new and cost-effective adsorbent N-TRAP, made from waste wood-shavings and anaerobically digestion biosolids and impregnated with H2SO4, was applied for the ammonia removal from air stream and biogas with high efficiency and effectiveness. Bearing a 75–80 and 65wt.% sulfuric acid, the N-TRAPs mediated with wood shavings and biosolids showed the maximum ammonia adsorption capacity of 260–280 and 230mgg−1, respectively. Gas temperatures (20 and 60°C) and moisture content (100% relative humidity) had no significantly negative effect on ammonia capture performance when temperature in the fixed-bed column was kept equalled to or slightly above the feed gas temperature. The pressure drop increased significantly when NH3 began to break through the N-TRAP stripper due to the formation of ammonium sulfate blocking the vacuum space of packed adsorbent. At last, an alternative N-TRAP filter bed design was proposed to resolve the problem of pressure drop evolution. [Copyright &y& Elsevier]

This paper attempts to provide insight into the biological ammonium oxidation process applied to high-strength ammonium wastewater treatment. The ammonium oxidation process has been investigated at various ammonium and biomass concentrations. Using the oxygen uptake rate (OUR) method, a proportion of both active ammonium oxidizers (AAO) and nitrite oxidizers to the total suspended solids were separately estimated, and then tested to normalize the ammonium oxidation rate at various ammonium strengths and AAO concentrations. High-ammonium strength showed no significant inhibition to ammonium oxidation due to high-AAO concentration. It was demonstrated that the key factor deciding the specific ammonium oxidation rate was the ratio of ammonium concentration to the active nitrifiers (AN) concentration, but not the sole-variable such as initial ammonium concentration and AN concentration. Contois model was screened to suitably fit the ammonium oxidation kinetics under the high-ammonium loading condition, resulting in a half-saturation constant of 0.028mgNmg−1 AAO and a maximum specific ammonium oxidation rate of 3.56gNg−1 AAOd−1. [Copyright &y& Elsevier]

Abstract: On the basis of the wastewater characteristic of anaerobically digested wastewater, this work studied the individual and simultaneous adsorption of ammonium and potassium ions by the natural clinoptilolite. Langmuir, Freundlich, Langmuir–Freundlich, and Toth model were employed to fit the experimental isotherm data and the fitting performances of different models were compared. Both the individual and simultaneous adsorption kinetics of ammonium and potassium were studied at various pHs and temperatures. The individual adsorption of ammonium was very fast and potassium uptake was even faster than that of ammonium. The adsorption approached equilibrium within 1h in most cases. Five models, including pseudo-first-order, pseudo-second-order, Vermeulen''s model, squared driving force model and Elovich equation were used to fit the individual and simultaneous adsorption kinetics of ammonium and potassium. The validities of the fittings for the ammonium and potassium adsorption kinetics were also evaluated. [Copyright &y& Elsevier]

Abstract: The nitrification and nitrite accumulation were studied in various free ammonia (FA) concentration and temperature combinations. Both ammonia oxidation rate and nitrite oxidation rate increased significantly with the increase in temperature from 10 to 30°C. The increase in the substrate oxidation rate with temperature was relatively faster for ammonia than nitrite. Nitrite accumulation started to occur at 20°C when the specific oxidation rate of ammonia showed a higher value than that of nitrite. Subsequently, the nitrite accumulation continuously increased with the increasing temperature from 20 to 30°C. The broad range in FA concentration exhibited negligible effect on the specific substrate utilization rate as well as the relative nitrite accumulation. On the basis of Arrhenius equation, the activation energies of ammonia oxidation were 87.1 and 38.6kJmol−1 in the temperature ranges 10–20°C and 20–30°C, respectively. However for the nitrite oxidation, the activation energy was obtained as a constant value of 34.2kJmol−1 in the temperature range of 10–30°C. [Copyright &y& Elsevier]

Abstract: Bead cellulose loaded with iron oxyhydroxide (BCF) with 47 mass% Fe content was prepared and was successfully applied to the elimination of arsenic from aqueous solutions. A clearer understanding of the arsenic removal mechanism will provide accurate prediction of the arsenic adsorptive properties of the new adsorbent. To study the mechanism of the adsorption process, we measured the extended X-ray absorption fine structure (EXAFS) spectra of arsenite and arsenate sorbed onto the adsorbent with different surface coverages. Both arsenite and arsenate were strongly and specifically adsorbed by akaganéite adsorptive centers on BCF by an inner-sphere mechanism. There was no change in oxidation state following interaction between the arsenic species and the BCF surface. The dominant complex of arsenic species adsorbed on akaganéite was bidentate binuclear corner-sharing (2C) between As(V) tetrahedra (or As(III) pyramids) and adjacent edge-sharing FeO6 octahedra. On the basis of the results from EXAFS spectra, the adsorptive characteristics of arsenic, such as the effects of pH and competing anions, were satisfactorily interpreted. [Copyright &y& Elsevier]

Abstract: For any number field, J.-F. Jaulent introduced a new invariant called the group of logarithmic classes in 1994. This invariant is proved to be closely related to the wild kernels of number fields. In this paper, we show how to compute the kernel of the natural homomorphism from the group of logarithmic classes to the group of p-ideal classes by computing the p-adic regulator which is a classical invariant in number theory. As an application, we prove Gangl''s conjecture on 9-rank of the tame kernel of imaginary quadratic field . [Copyright &y& Elsevier]

In this paper, it is proved that if F is a global field, then for any integer n > 3, there is an extension field E over F of degree n such that K 2 E is not generated by the Steinberg symbols { a , b } with a ? F *, b , ? E *. If however, F is a number field and D is a finite-dimensional central division F -algebra with square free index, then K 2 D is always generated by the Steinberg symbols { a , b } with a ? F *, b ? D *. Finally, the tame kernels of central division algebras over F are expressed explicitly. [ABSTRACT FROM AUTHOR]

In this paper we study the possible torsion in even-dimensional higher class groups Cl 2 n (?)( n = 1) of an order ? in a semisimple algebra A over a number field F with a ring of integers ?? F . We show that for certain orders, called generalized Eichler orders, bip -torsion in Cl 2 n (?) can only occur for primes p dividing prime ideals P of ?? F , at which ? is not maximal. In particular, the results apply to Eichler orders in quaternion algebras and to hereditary orders. [ABSTRACT FROM AUTHOR]

Let B be a quaternion algebra over number field K. Assume that B satisfies the Eichler condition (i.e., there is at least one archimedean place which is unramified in B). Let Ω be an order in a quadratic extension L of K. The Eichler orders of B which admit an embedding of Ω are determined. This is a generalization of Chinburg and Friedman''s embedding theorem for maximal orders. [Copyright &y& Elsevier]

For a number field F, it is proved that the K2-semigroup K2(F,F++) defined in [R.V. Moody, J. Morita, J. Algebra 229 (2000) 1] has similar properties to the positive K2 group K2+(F) introduced by Gras in [J. Number Theory 23 (1986) 322]. [Copyright &y& Elsevier]

In this paper, it is proved that the tame kernel of [Qopf](ζ8) is trivial. [ABSTRACT FROM AUTHOR]

Chronic asthma is characterized by airway hyperresponsiveness, inflammation, and remodeling. Previous studies have shown that mesenchymal stromal/stem cells (MSCs) exert anti-inflammatory effects on asthma via regulation of the immune cells. However, the therapeutic mechanism of MSCs, especially the mechanism of airway remodeling in chronic asthma, remains to be elucidated. Here, we aimed to investigate the therapeutic effect of MSCs on airway remodeling in chronic asthma and explored the mechanisms by analyzing the polarization phenotype of macrophages in the lungs. We established a mouse model of chronic asthma induced by ovalbumin (OVA) and evaluated the effect of MSCs on airway remodeling. The data showed that MSCs treatment before the challenge exerted protective effects on OVA-induced chronic asthma, i.e., decreased the inflammatory cell infiltration, Th2 cytokine levels, subepithelial extracellular matrix deposition, and transforming growth factor β (TGF-β)/Smad signaling. Additionally, we found that MSCs treatment markedly suppressed macrophage M2 polarization in lung tissue. At the same time, MSCs treatment inhibited NF-κB p65 nuclear translocation, ER stress, and oxidative stress in the OVA-induced chronic allergic airway remodeling mice model. In conclusion, these results demonstrated that MSCs treatment prevents OVA-induced chronic airway remodeling by suppressing macrophage M2 polarization, which may be associated with the dual inhibition of ER stress and oxidative stress. This discovery may provide a new theoretical basis for the future clinical application of MSCs. [ABSTRACT FROM AUTHOR]

We aimed to determine the molecular characteristics of carbapenem-resistant Pseudomonas aeruginosa strains 18081308 and 18083286, which were isolated from the urine and the sputum of two Chinese patients, respectively. Additionally, we conducted a comparative analysis between Tn6411 carrying blaIMP-1 in strain 18083286 and transposons from the same family available in GenBank. Bacterial genome sequencing was carried out on strains 18081308 and 18083286 to obtain their whole genome sequence. Average nucleotide identity (ANI) was used for their precise species identification. Serotyping and multilocus sequence typing were performed. Furthermore, the acquired drug resistance genes of these strains were identified. The carbapenem-resistant P. aeruginosa strains isolated in the present study were of sequence type ST865 and serotype O6. They all carried the same resistance genes (aacC2, tmrB, and blaIMP-1). Tn6411, a Tn7-like transposon carrying blaIMP-1, was found in strain 18083286 by single molecule real time (SMRT) sequencing. We also identified the presence of this transposon sequence in other chromosomes of P. aeruginosa and plasmids carried by Acinetobacter spp. in GenBank, indicating the necessity for heightening attention to the potential transferability of this transposon. [ABSTRACT FROM AUTHOR]

We have developed a real-time multiplex PCR assay to detect the three most common 16S rRNA methyltransferase genes ( armA , rmtB and rmtC ), which encode problematic high-level resistance to all clinically-relevant aminoglycoside antibiotics. All results were consistent with published conventional PCR assays and these genes still appear rare in Australia. [ABSTRACT FROM AUTHOR]

Let p be a prime of the form 2 ℓ + 1 or 4 ℓ + 1 , where ℓ is also a prime. We prove θ (χ , i) ≠ 0 for all primitive Dirichlet characters χ with conductor p except for the quadratic and the quartic ones. Our results generalize a theorem of Bengoechea, which asserts θ (χ , i) ≠ 0 for non-quadratic χ with "large" prime conductor p = 2 ℓ + 1 , where ℓ is also a prime. [ABSTRACT FROM AUTHOR]

• ZVI-S and ZVI-P differed significantly in P removal when combined with NaClO. • ZVI-P/NaClO achieved rapid and long-effective removal of P from water. • The high purity Fe (ZVI-S) was readily passivated by high content of P itself. • P removal from water by ZVI/NaClO should consider the screening of ZVI type. Rapid and long-effective removal of phosphate (P) from water was achieved by simply using zero-valent iron coupled with hypochlorite (ZVI/NaClO). Two irons, steel iron (ZVI-S) and pig iron (ZVI-P) were tested. The removal rate of P by ZVI-P alone was observed to 94.2 (94.2), 96.5 (88.3) and 76.2 (33.8) %, respectively, at 0.5, 1.0 and 5.0 mg/L of initial P concentrations under oxic (anoxic) conditions. The combination of NaClO with ZVI-P remarkably enhanced the percentages of P removal to 94.8–98.2%, regardless of initial-P concentrations and aeration conditions. At 5.0 mg/L of initial P, the coupling of ZVI-P and NaClO also achieved a rapid and long-effective removal of P, resulting in a 96.4–97.8% of P removal during 12 batch recycles, with residual concentration of P averaged at 0.04 mg/L during the long-term of column running with only 12 min of empty-bed contact time (EBCT). The oxidant, NaClO, drove a rapid increase in iron corrosion, which was probably favored by microscopic galvanic effect between elemental carbon and iron, and less degree of iron crystallinity with more crystal defects. However, a limited enhancement of P removal by ZVI-S was observed in presence of oxygen and even spiked with NaClO. The formation of a stable passivation layer composted of ferric oxides and FePO 4 on ZVI-S surface was strongly indicated, which might block the oxidative attack from dissolved O 2 and even NaClO. [ABSTRACT FROM AUTHOR]

Antimony (Sb) and its compounds, toxic metalloid, have been classified as high-priority pollutants. Increasing Sb released into the water environment by natural processes and anthropogenic activities, which exposure threatens to human health and ecosystems. Therefore, it is of unquestionable importance to remove Sb from polluted water. Keeping in view the extreme importance of this issue, we summarize the source, chemistry, speciation, distribution, toxicity, and polluted situation of Sb about aqueous solution. Then, we provide the recent and common technology to remove Sb, which are based on adsorption, coagulation/flocculation, electrochemical technology, membrane technology, ion exchange, etc. In this review, we focus in detail on the adsorption method, researchers at present have been investigating to discover more advanced, cost-effective, eco-friendly, reusable adsorbents. However, to date the Sb-containing wastewater treatment technologies are not sufficiently developed and most of research have been tested only in controlled lab conditions. Few reports are available that include field studies and applications. We critically analyzed the salient features and removal mechanisms, evaluating benefits and limitations of these technologies, hoping to provide more references for further research. Finally, we considered the Fe- or Mn-based technologies was the most promising technique to remove Sb for field application. Image 1 [ABSTRACT FROM AUTHOR]

Ankylosing spondylitis (AS) is a chronic inflammatory rheumatic disease. MicroRNAs (miRNAs) are a group of endogenous small non-coding RNAs that regulate target genes, and play a critical role in many biological processes. However, the underlying mechanism of specific miRNA, miR-130a-3p, in AS remains largely unknown. Therefore, the present study aimed to explore the underlying mechanism of miR-130a-3p in the development of AS. In the present study, it was revealed that miR-130a-3p was downregulated in T cells from HLA-B27-positive AS patients compared with the HLA-B27-negative healthy controls. Next, bioinformatics software TargetScan 7.2 was used to predict the target genes of miR-130a-3p, and a luciferase reporter assay indicated that HOXB1 was the direct target gene of miR-130a-3p. Furthermore, it was determined that HOXB1 expression was upregulated in T cells from HLA-B27-positive AS patients. In addition, the results of the present study indicated that miR-130a-3p inhibitor significantly inhibited cell proliferation ability and induced cell apoptosis of Jurkat T cells, while the miR-130a-3p mimic promoted proliferation ability and inhibited cell apoptosis of Jurkat T cells. Notably, all the effects of the miR-130a-3p mimic on Jurkat T cells were reversed by HOXB1-plasmid. Collectively, our data indicated that miR-130a-3p was decreased in T cells from AS patients and it could regulate T-cell survival by targeting HOXB1. [ABSTRACT FROM AUTHOR]

Obstructive sleep apnea (OSA) is associated with severity of pneumonia; however, the mechanism by which OSA promotes lung cancer progression is unclear. Twenty-five lung cancer patients were recruited to investigate the relationship between OSA and cancer-associated fibroblast (CAFs) activation. Lung cancer cells (A549) and WI38 fibroblast cells were used to explore the hypoxia-induced TGFβ expression using qPCR, Western blot, and ELISA. Wound healing and transwell assays were performed to evaluate cancer cell migration and invasion. A549 or A549-Luc + WI38 xenograft mouse models were established to detect the intermittent hypoxia (IH) associated with lung tumor growth and epithelial–mesenchymal transition (EMT) in vivo. OSA promotes CAF activation and enrichment in lung cancer patients. Hypoxia (OSA-like treatment) activated TGFβ signaling in both lung cancer cells and fibroblasts, which promoted cancer cell migration and invasion, and enriched CAFs. IH promoted the progression and EMT process of lung cancer xenograft tumor. Co-inoculation of lung cancer cells and fibroblast cells could further promote lung cancer progression. IH promotes lung cancer progression by upregulating TGFβ signaling, promoting lung cancer cell migration, and increasing the CAF activation and proportion of lung tumors. [ABSTRACT FROM AUTHOR]

Objective: Catheter-associated urinary tract infections (CAUTI) are common worldwide, but due to limited resources, its actual burden in low-income countries is unknown. Currently, there are gaps in knowledge about CAUTI due to lack of surveillance activities in Sierra Leone. In this prospective cohort study, we aimed to determine the incidence of CAUTI and associated antibiotic resistance in two tertiary hospitals in different regions of Sierra Leone. Results: The mean age of the 459 recruited patients was 48.8 years. The majority were females (236, 51.3%). Amongst the 196 (42.6%) catheterized patients, 29 (14.8%) developed CAUTI. Bacterial growth was reported in 32 (84%) patients. Escherichia coli (14, 23.7%), Klebsiella pneumoniae (10, 17.0%), and Klebsiella oxytoca (8, 13.6%) were the most common isolates. Most isolates were ESBL-producing Enterobacteriaceae (33, 56%) and WHO Priority 1 (Critical) pathogens (38, 71%). Resistance of K. pneumoniae, K. oxytoca, E. coli, and Proteus mirabilis was higher with the third-generation cephalosporins and penicillins but lower with carbapenems, piperacillin-tazobactam and amikacin. To reduce the high incidence of CAUTI and multi-drug resistance organisms, urgent action is needed to strengthen the microbiology diagnostic services and develop and implement catheter bundles that provide clear guidance for catheter insertion, care and removal. [ABSTRACT FROM AUTHOR]

Background: The aim of this study is to identify whether the balance between T helper 17 (Th17) cells and CD4+CD25+Foxp3+ regulatory T (Treg) cells could predict the postoperative atrial fibrillation (POAF) after coronary artery bypass graft surgery (CABG).Methods: We enrolled 88 patients from Xinhua Hospital who received off-pump CABG (OPCABG) surgery. The baseline characteristics of patients were recorded. The preoperative variables C-reactive protein (CRP) level, left atrial (LA) volume, EuroSCORE I score, CHADS2 score, and CHA2DS2-VASc score were calculated at enrolment. Circulating Th17 and Treg cell frequencies were determined by flow cytometry, and expressions of Th17- and Treg-related cytokines were measured by enzyme-linked immunosorbent assay (ELISA).Results: Compared to patients without POAF, the CRP level and peripheral circulating Th17 cell were significantly increased in POAF patients. Th17/Treg ratio was positively correlated with CRP level, LA volume, CHADS2 score, and CHA2DS2-VASc score. The areas under the receiver-operating characteristic (AUC) curves of Th17/Treg ratio for predicting POAF occurrence was higher than that of CRP level, LA volume, CHADS2 score and CHA2DS2-VASc score. Th17/Treg ratio combined with CRP level has the highest AUC and a greater balance between sensitivity and specificity for predicting POAF.Conclusions: Our data suggest that a Th17/Treg imbalance due to a Th17 shift, representing a pro-inflammatory tendency, participates in the development of POAF. Combining the Th17/Treg ratio with CRP level may provide a more accurate, sensitive, and specific indicator for prediction of POAF. [ABSTRACT FROM AUTHOR]

Highlights • Mechanism of Sb accumulated in RBCs was explored by in vitro and in vivo studies. • Parent form of Sb had notable affinity with RBCs but negligible affinity with Hb. • In vivo studies demonstrated that most of Sb metabolites were integrated into Hb. • Liver metabolism played a potential role influencing Sb’s partitioning in blood. • Nano-HPLC–MS/MS suggested Sb(CH 3) 2 O 2 H conjugated with Hb (α chain, Cys104/Cys111). Abstract Toxicity of antimony (Sb) to humans may occur through environmental, occupational, and therapeutic exposures. The underlying mechanism of its accumulation in red blood cells (RBCs) is not clear. Here, the processes and mechanism of RBCs sequestering Sb were explored through a series of in vitro and in vivo studies. These include binding affinity of Sb compounds with rat hemoglobin (Hb) and RBCs, acute exposure of antimony potassium tartrate (APTIII), and subchronic oral exposure of APTIII, potassium pyroantimonate (PPV) and antimony trioxide (ATIII). In vitro study indicated that parent form of Sb exhibited notable affinity with RBCs, while represented negligible affinity with Hb. However, after acute exposure to APTIII, over 93% of Sb in rat blood was integrated into Hb. Sb retaining in liver homogenate supernatants was substantially integrated into Hb, which indicated liver metabolism played a potential role influencing its ultimate partitioning in blood. Subchronic exposure of APTIII, PPV and ATIII to rats also demonstrated that most of Sb metabolites were integrated into Hb, regardless of which Sb compounds administered. Nano-HPLC–MS/MS analysis suggested that a dimethylated Sb species in pentavalent state [Sb(CH 3) 2 O 2 H] was a major Sb group conjugated with Hb at Cys 104 and Cys 111 especially, in α chain of rat Hb. Hb-conjugated Sb did not affect Hb’s oxygen binding capability. As the deposit sites for both the parent forms and the metabolite, Sb re-released to circulation system due to RBCs and Hb degradation could have high substantial toxicological effects on its potential sites of action. [ABSTRACT FROM AUTHOR]

Background: Carbapenem-resistant Klebsiella pneumoniae (CRKP) infection is a serious problem in hospitals worldwide. We monitored a tertiary hospital in Changchun, Jilin Province, China, and found that CRKP was the major species among the carbapenem-resistant isolates in sewage. Subsequently, we evaluated the drug susceptibility, resistance genes, virulence genes, outer pore membrane protein-related genes (OmpK35 & OmpK 36), multi-locus sequence typing and replicons, biofilm formation capabilities, and resistance to chlorine-containing disinfectants among KP isolates. Identification of drug sensitivity, multiple resistance profiles were observed including 77 (82.80%) multidrug resistant (MDR), 16 (17.20%) extensive drug resistant (XDR). Some antibiotic resistance genes were detected, the most prevalent carbapenemase gene was blaKPC, and 16 resistance genes were associated with other antibiotics. In addition, 3 (3.23%) CRKP isolates demonstrated loss of OmpK-35 and 2 (2.15%) demonstrated loss of OmpK-36. In the detection of multi-locus sequence typing (MLST), 11 ST11 isolates carried virulence genes. The most common replicon type was IncFII. Biofilm-forming capabilities were demonstrated by 68.8% of the isolates, all of which were resistant to chlorine-containing disinfectants. The results of the study showed that antibiotic-resistant isolates, especially CRKP, could resist disinfectants in hospital wastewater, and improper treatment of hospital wastewater may lead to the spread of drug-resistant bacteria and their genes. Thus, these bacteria must be eliminated before being discharged into the municipal sewage system. [ABSTRACT FROM AUTHOR]