Simultaneous Degradation, Dehalogenation, and Detoxification of Halogenated Antibiotics by Carbon Dioxide Radical Anions

Despite the extensive application of advanced oxidation processes(AOPs)in water treatment,the efficiency of AOPs in eliminating various emerging contaminants such as halogenated antibiotics is constrained by a number of factors.Halogen moieties exhibit strong resistance to oxidative radicals,affecting the dehalogenation and detoxification efficiencies.To address these limitations of AOPs,advanced reduction processes(ARPs)have been proposed.Herein,a novel nucleophilic reductant—namely,the carbon dioxide radical anion(CO_(2)^(·-))—is introduced for the simultaneous degradation,dehalogenation,and detoxification of florfenicol(FF),a typical halogenated antibiotic.The results demonstrate that FF is completely eliminated by CO_(2)^(·-),with approximately 100%of Cland 46%of Freleased after 120 min of treatment.Simultaneous detoxification is observed,which exhibits a linear response to the release of free inorganic halogen ions(R^(2)=0.97,p<0.01).The formation of halogen-free products is the primary reason for the superior detoxification performance of this method,in comparison with conventional hydroxyl-radical-based AOPs.Products identification and density functional theory(DFT)calculations reveal the underlying dehalogenation mechanism,in which the chlorine moiety of FF is more susceptible than other moieties to nucleophilic attack by CO_(2)^(·-).Moreover,CO_(2)^(·-)-based ARPs exhibit superior dehalogenation efficiencies(>75%)in degrading a series of halogenated antibiotics,including chloramphenicol(CAP),thiamphenicol(THA),diclofenac(DLF),triclosan(TCS),and ciprofloxacin(CIP).The system shows high tolerance to the pH of the solution and the presence of natural water constituents,and demonstrates an excellent degradation performance in actual groundwater,indicating the strong application potential of CO_(2)^(·-)-based ARPs in real life.Overall,this study elucidates the feasibility of CO_(2)^(·-)for the simultaneous degradation,dehalogenation,and detoxification of halogenated antibiotics and provides a promising method for their regulation during water or wastewater treatment.

New Insights into Microplastic Contamination in Different Types of Leachates: Abundances, Characteristics, and Potential Sources

Municipal solid waste(MSW)is an important destination for abandoned plastics.During the waste disposal process,large plastic debris is broken down into microplastics(MPs)and released into the leachate.However,current research only focuses on landfill leachates,and the occurrence of MPs in other leachates has not been studied.Therefore,herein,the abundance and characteristics of MPs in three types of leachates,namely,landfill leachate,residual waste leachate,and household food waste leachate,were studied,all leachates were collected from the largest waste disposal center in China.The results showed that the average MP abundances in the different types of leachates ranged from(129±54)to(1288±184)MP particles per liter(particlesL1)and the household food waste leachate exhibited the highest MP abundance(p<0.05).Polyethylene(PE)and fragments were the dominant polymer type and shape in MPs,respectively.The characteristic polymer types of MPs in individual leachates were different.Furthermore,the conditional fragmentation model indicated that the landfilling process considerably affected the size distribution of MPs in leachates,leading to a higher percentage(>80%)of small MPs(20–100 lm)in landfill leachates compared to other leachates.To the best of our knowledge,this is the first study discussing the sources of MPs in different leachates,which is important for MP pollution control during MSW disposal.

化学化工虚拟仿真实验教学平台的建设与应用

虚拟仿真教学是近年来一种新型教学模式,是一种融合多学科、多区域、多层次的实验教学方法,以天津大学化学化工虚拟仿真实验平台建设为例,介绍化学化工安全知识、理论知识、实验内容的有机融合,虚拟仿真资源的具体内容及虚拟仿真实验平台的特色。提供了一种虚拟仿真资源与传统教学资源高效结合的新模式,推动了化学化工类实验教学的发展。

由邻苯二甲酸二乙酯制备水合茚三酮的反应机理探讨

以邻苯二甲酸二乙酯为原料,经Claisen酯缩合反应、酸性酯水解反应、热脱羧反应、亚硝化反应、脱肟反应、羰基还原反应、Aldol反应、邻二醇氧化裂解反应制备了水合茚三酮,对各步的反应机理进行了详细的讨论。

Defense Against Poisoning Attack via Evaluating TrainingSamples Using Multiple Spectral Clustering Aggregation Method

The defense techniques for machine learning are critical yet challenging due tothe number and type of attacks for widely applied machine learning algorithms aresignificantly increasing. Among these attacks, the poisoning attack, which disturbsmachine learning algorithms by injecting poisoning samples, is an attack with the greatestthreat. In this paper, we focus on analyzing the characteristics of positioning samples andpropose a novel sample evaluation method to defend against the poisoning attack cateringfor the characteristics of poisoning samples. To capture the intrinsic data characteristicsfrom heterogeneous aspects, we first evaluate training data by multiple criteria, each ofwhich is reformulated from a spectral clustering. Then, we integrate the multipleevaluation scores generated by the multiple criteria through the proposed multiplespectral clustering aggregation (MSCA) method. Finally, we use the unified score as theindicator of poisoning attack samples. Experimental results on intrusion detection datasets show that MSCA significantly outperforms the K-means outlier detection in terms ofdata legality evaluation and poisoning attack detection.

Rolling Bearing Remaining Useful Life Prediction Based on Wiener Process

Rolling bearing is the key part of mechanical system.Accurate prediction of bearing life can reduce maintenance costs,improve availability,and prevent catastrophic consequences,aiming at solving the problem of the nonlinear,random and small sample problems faced by rolling bearings in actual operating conditions.In this work,the nonlinearWiener process with random effect and unbiased estimation of unknown parameters is used to predict the remaining useful life of rolling bearings.Firstly,random effects and nonlinear parameters are added to the traditional Wiener process,and a parameter unbiased estimation method is used to estimate the positional parameters of the constructed Wiener model.Finally,the model is validated using a common set of bearing datasets.Experimental results show that compared with the traditional maximum likelihood function estimation method,the parameter unbiased estimation method can effectively improve the accuracy and stability of the parameter estimation results.The model has a good fitting effect,which can accurately predict the remaining useful life of rolling bearing.

Synchronous primary cancer of the rectum and lung:a case report

Multiple primary cancers refer to the condition where more than two cancers occur independently in an individual. The incidence of lung cancer in cases of colorectal cancer is rare and synchronous rectal cancer and lung cancer is even rare. A 61-year-old man was referred to our hospital with a 2-month history of blood in his stool, tenesmus, and mucous discharge in July 2010. Colonoscopy showed an irregular ulcerated rectal mass and histological examination of biopsy material showed a poorly differentiated adenocarcinoma. Computed tomography （CT） scan of the chest and abdomen showed a mass in the posterior segment of the right upper lobe of the lung and a mass in the right rectal wall of upper rectum. The rectal tumor was diagnosed as primary cancer based on the findings of immunohistochemical stain. An anterior resection （AR） and video assisted thoracoscopic （VAT） wedge resection were performed and histological findings of resected rectal and lung tumor specimen showed synchronous primary rectal cancer and lung cancer. A combination chemotherapy regimen with docetaxel and Iobaplatin was used and the patient was successfully discharged from hospital in August 2010. Although the incidence of synchronous multiple primary cancers is very low, we need to remain suspicious, when faced with two or even multiple organ lesions, and employ the necessary examination methods to confirm the diagnosis. For synchronous multiple primary cancers, if conditions allow, surgical resection for all the cancers can be performed in a single operation.

Toward a rapid and convenient nanoplastic quantification method in laboratory-scale study based on fluorescence intensity

The thorough investigation of nanoplastics(NPs)in aqueous environments requires efficient and expeditious quantitative analytical methods that are sensitive to environmentally relevant NP concentrations and convenient to employ.Optical analysis-based quantitative methods have been acknowledged as effective and rapid approaches for quantifying NP concentrations in laboratory-scale studies.Herein,we compared three commonly used optical response indicators,namely fluorescence intensity(FI),ultraviolet absorbance,and turbidity,to assess their performance in quantifying NPs.Furthermore,orthogonal experiments were conducted to evaluate the influence of various water quality parameters on the preferred indicator-based quantification method.The results revealed that FI exhibits the highest correlation coefficient(>0.99)with NP concentration.Notably,the limit of quantification(LOQ)for various types of NPs is exceptionally low,ranging from 0.0089 to 0.0584 mg/L in ultrapure water,well below environmentally relevant concentrations.Despite variations in water quality parameters such as pH,salinity,suspended solids(SS),and humic acid,a robust relationship between detectable FI and NP concentration was identified.However,an increased matrix,especially SS in water samples,results in an enhanced LOQ for NPs.Nevertheless,the quantitative method remains applicable in real water bodies,especially in drinking water,with NP LOQ as low as 0.0157–0.0711 mg/L.This exceeds the previously reported detectable concentration for 100 nm NPs at 40µg/mL using surface-enhanced Raman spectroscopy.This study confirms the potential of FI as a reliable indicator for the rapid quantification of NPs in aqueous environments,offering substantial advantages in terms of both convenience and cost-effectiveness.

Screening of indicator pharmaceuticals and personal care products in landfill leachates: a case study in Shanghai, China

Identifying potential sources of pharmaceuticals and personal care products(PPCPs)in the environment is critical for the effective control of PPCP contamination.Landfill leachate is an important source of PPCPs in water;however,it has barely been involved in source apportionment due to the lack of indicator-PPCPs(i-PPCPs)in landfill leachates.This study provides the first systematic framework for identifying i-PPCPs for landfill leachates based on the wide-scope target monitoring of PPCPs.The number of target PPCPs increased from<20 in previous studies to 68 in the present study.Fifty-nine PPCPs were detected,with median concentrations in leachate samples ranging from below the method quantification limit(MQL)to 41μg/L,and 19 of them were rarely reported previously.A total of 29 target compounds were determined to be PPCPs of high concern by principal component analysis according to multiple criteria,including occurrence,exposure potential,and ecological effect.Coupled with source-specificity and representativeness analysis,erythromycin,gemfibrozil,and albendazole showed a significant difference in their occurrence in leachate compared to other potential sources(untreated and treated municipal wastewater and livestock wastewater)and correlated with total PPCP concentrations;these were recommended as i-PPCPs for leachates.Indicator screening procedure can be used to develop a sophisticated source apportionment method to identify sources of PPCPs from adjacent landfills.

ELP3 stabilizes c-Myc to promote tumorigenesis

ELP3,the catalytic subunit of the Elongator complex,is an acetyltransferase and associated with tumor progression.However,the detail of ELP3 oncogenic function remains largely unclear.Here,we found that ELP3 stabilizes c-Myc to promote tumorigenesis in an acetyltransferase-independent manner.Mechanistically,ELP3 competes with the E3-ligase FBXW7βfor c-Myc binding,resulting in the inhibition of FBXW7β-mediated ubiquitination and proteasomal degradation of c-Myc.ELP3 knockdown diminishes glycolysis and glutaminolysis and dramatically retards cell proliferation and xenograft growth by downregulating c-Myc,and such effects are rescued by the reconstitution of c-Myc expression.Moreover,ELP3 and c-Myc were found overexpressed with a positive correlation in colorectal cancer and hepatocellular carcinoma.Taken together,we elucidate a new function of ELP3 in promoting tumorigenesis by stabilizing c-Myc,suggesting that inhibition of ELP3 is a potential strategy for treating c-Myc-driven carcinomas.

A comparison of the catalytic hydrogenation of 2-amylanthraquinone and 2-ethylanthraquinone over a Pd/Al2O3 catalyst

The hydrogenation of 2-ethylanthraquinone （eAQ）, 2-tert-amylanthraquinone （taAQ） and their mixtures with molar ratios of 1：1 and 1：2 to the corresponding hydroquinones （eAQH2 and taAQH2） were studied over a Pd/Al2O3 catalyst in a semi-batch slurry reactor at 60 ℃ and at 0.3 MPa. Compared to eAQ, TaAQ exhibited a significantly slower hydrogenation rate （about half） but had a higher maximum yield of H2O2 and a smaller amount of degradation products. This can be ascribed to the longer and branched side chain in taAQ, which limits its accessibility to the Pd surface and its diffusion through the pores of the catalyst. Density functional theory calculations showed that it is more difficult for taAQ to adsorb onto a Pd （111） surface than for eAQ. The hydrogenation of the eAQ/taAQ mixtures had the slowest rates, lowest H2O2 yields and the highest amounts of degradation products.

Removal of pharmaceutical and personal care products by sequential ultraviolet and ozonation process in a full-scale wastewater treatment plant

The application of appropriate advanced treat- ment process in the municipal wastewater treatment plants （WWTPs） has become an important issue considering the elimination of emerging contaminants, such as pharma- ceutical and personal care products （PPCPs）. In the present study, the removal of 13 PPCPs belonging to different therapeutic classes by the sequential ultraviolet （UV） and ozonation process in a full-scale WWTP in Beijing was investigated over the course of ten months. Most of the target PPCPs were effectively removed, and the median removal efficiencies of individual PPCPs, ranging from -13% to 89%, were dependent on their reaction rate constants with molecular ozone. Noticeable fluctuation in the removal efficiencies of the same PPCPs was observed in different sampling campaigns. Nevertheless, the sequential UV and ozonation process still made a significant contribution to the total elimination of most PPCPs in the full-scale WWTP, by compensating for the poor or fluctuant removal performance of PPCPs by biologic treatment process.

Occurrence, sources and fate of pharmaceuticals and personal care products in the groundwater: A review

The presence of pharmaceuticals and personal care products(PPCPs)in the aquatic environment may pose potential threat to the ecosystem and human health,hence PPCPs have aroused much concern over the world.The contamination of PPCPs in the groundwater,the main source of drinking water supply in many countries and regions,has been extensively studied in the last decade.This paper reviews the occurrence of frequently detected PPCPs,including antibiotics,anti-inflammatories,lipid-regulators,carbamazepine,caffeine,and N,N-diethyl-m-toluamide in groundwater,with special concern to the progress made over the past three years.Possible emission sources for PPCPs in groundwater,such as wastewater and contaminated surface water,landfills,septic systems,livestock breeding and sewer leakage,are summarized.Besides,adsorption,migration and degradation,the dominant mechanisms in the subsurface transport and fate of PPCPs,are discussed,and the insights into the future study of PPCPs in the groundwater are provided.

Recent advances in pharmaceuticals and personal care products in the surface water and sediments in China

Pharmaceuticals and personal care products （PPCPs） have been regarded as an emerging problem in the surface water environment in the past few decades. In China, although related studies were initiated several years ago, an increasing number of studies on this topic have been conducted in recent years. These studies have expanded knowledge of their occurrence, behavior and associated risk in the surface water environment in China. This review compiles the most recent literature related to the studies of PPCPs in the surface water environment in China. It includes PPCP occurrence in surface water and sediments, their geographical distribution, and outcomes of the associated risk assessment. It shows that antibiotics have received much more attention in both surface water and sediments than other PPCPs. Compared to other countries; most antibiotics in the collected sediments in China showed higher contamination levels. Many more study areas have been covered in recent years; however, attention has been given to only specific areas. Environmental risk assessment based on risk quotients indicated that sulfamethoxazole presents the most significant environmental risk to relevant aquatic organisms; followed by ofloxacin, ciprofloxacin, enrofloxacin, 17α-ethynylestradiol, ibuprofen and diclofenac. Despite limited research on the environmental risk assessment of PPCPs in sediments, higher risks posed by PPCPs in the sediments rather than surfhce water were identified highlighting the need for further risk assessment of PPCPs in sediment samples.

Porous α-Fe_(2)O_(3)/SnO_(2) nanoflower with enhanced sulfur selectivity and stability for H_(2)S selective oxidation

Being abundant and active,Fe_(2)O_(3) is suitable for selective oxidation of H_(2)S.However,its practical application is limited due to the poor sulfur selectivity and rapid deactivation.Herein,we report a facile template-free hydrothermal method to fabricate porousα-Fe_(2)O_(3)/SnO_(2) composites with hierarchical nanoflower that can obviously improve the catalytic performance of Fe_(2)O_(3).It was disclosed that the synergistic effect betweenα-Fe_(2)O_(3) and SnO_(2) promotes the physico-chemical properties ofα-Fe_(2)O_(3)/SnO_(2) composites.Specifically,the electron transfer between the Fe^(2+)/Fe^(3+)and Sn^(2+)/Sn^(4+)redox couples enhances the reducibility ofα-Fe_(2)O_(3)/SnO_(2) composites.The number of oxygen vacancies is improved when the Fe cations incorporate into SnO_(2) structure,which facilitates the adsorption and activation of oxygen species.Additionally,the porous structure improves the accessibility of H_(2) S to active sites.Among the composites,Fe1 Sn1 exhibits complete H_(2) S conversion with 100%sulfur selectivity at 220℃,better than those of pureα-Fe_(2)O_(3) and SnO2.Moreover,Fe1 Sn1 catalyst shows high stability and water resistance.

Biodegradation of bezafibrate by the activated sludge under aerobic condition:Effect of initial concentration,temperature and pH

Lab-scale experiments were conducted to investigate the effect of initial concentration,temperature and pH on the removal of bezafibrate(BF)by activated sludge under aerobic condition.The results showed that adsorption of BF onto activated sludge was negligible,and biodegradation was the main removal mechanism of BF.The removal of BF in the aqueous phase by the activated sludge can be described by a pseudo-first-order reaction.The reaction rate constants had a negative relationship with the initial concentration of BF,and dramatically reduced from 0.050 to 0.007 h^-1,when the temperature dropped from 20℃to 10℃.Variation of pH between 5.0 and 9.0 did not have significant influence on the removal of BF,indicating a high adaptation of microorganism in the activated sludge responsible for BF degradation to a wide pH range.The findings of this study are helpful to improve the removal of pharmaceuticals during the wastewater treatment plants by selecting the appropriate process variables,and eventually eliminate their release to the environment.

Effect of effluent organic matter on ozonation of bezafibrate

The influence of three effluent organic matter （EfOM） model compounds, humic acid （HA）, bovine serum albumin （BSA）, and sodium alginate （AGS）, on the ozonation ofbezafibrate （BF）, a typical pharmaceutical and personal care product （PPCP）, was investigated. The results show that ozonation efficiently removed BF from aqueous solution with removal efficiencies 〉 95% within 8 min for all conditions. The reaction rate of BF decreased with increasing model compounds concentrations and the influence was more pronounced for HA and BSA, while less pronounced for AGS. Although BF concentration was significantly reduced, the degree of mineralization achieved was only approximately 11%. The addition of HA and BSA improved the mineralization of the solution, while the influence of AGS was minor. The acute toxicity of BF solution during ozonation was determined using the Luminescent bacteria test, and the toxicity exhibited an initial increase and a successive reduction. An overall decreased acute toxicity was observed with an increase of HA. The presence of BSA increased the formation rate of toxicity intermediates and resulted in inhibition peak forward.

Origins of catalyst-controlled enantiodivergent hydroamination of enones with pyridazinones:A computational study

Density functional theory calculations have been performed to investigate the dipeptide phosphinecatalyzed hydroamination of enones with pyridazinones.The computations reveal that a number of the N-H...O hydrogen-bonding interactions with the pyridazinone moiety and the C–H...O hydrogenbonding interactions with the enone moiety are present in the enantioselectivity-determining Michael addition transition states.The experimentally-observed catalyst-controlled enantiodivergence is mainly attributed to the significant impact of the substituent of the amide moiety of the dipeptide phosphine on the relative strength of the N-H...O hydrogen-bonding interactions,which was found to affect the Si face attack transition state,enabling the enantioselectivity switch upon change of chiral dipeptide phosphine catalyst.

Mechanism and selectivity of copper-catalyzed borocyanation of 1-aryl-1,3-butadienes:A computational study

Density functional theory calculations have been performed to investigate the copper-catalyzed borocyanation of 1-aryl-1,3-butadienes.The computations show that the regio-and enantioselectivity is determined by the borocupration step.The π-electron withdrawing aryl group at the C' atom makes the C4 atom more electrophilic than the other carbon atoms,which together with the steric repulsion around the forming C-B bond,re sults in the experimentally observed exclusive 4,3-regioselectivity.The origins of the enantioselectivity were attributed to the steric effect and π-π stacking interaction between the butadiene moiety and the ligand.