Sulfur doping-induced morphological and electronic structure modification of polyoxometalate FeWO4 for enhanced removal of organic pollutants from water.

Wolframite (FeWO4), a typical polyoxometalate, serves as an auspicious candidate for heterogeneous catalysts, courtesy of its high chemical stability and electronic properties. However, the electron-deficient surface-active Fe species in FeWO4 are insufficient to cleave H2O2 via Fe redox-mediated Fenton-like catalytic reaction. Herein, we doped Sulfur (S) atom into FeWO4 catalysts to refine the electronic structure of FeWO4 for H2O2 activation and sulfamethoxazole (SMX) degradation. Furthermore, spin-state reconstruction on S-doped FeWO4 was found to effectively refine the electronic structure of Fe in the d orbital, thereby enhancing H2O2 activation. S doping also accelerated electron transfer during the conversion of sulfur species, promoting the cycling of Fe(III) to Fe(II). Consequently, S-doped FeWO4 bolstered the Fenton-like reaction by nearly two orders of magnitude compared to FeWO4. Significantly, the developed S-doped FeWO4 exhibited a remarkable removal efficiency of approximately 100% for SMX within 40 min in real water samples. This underscores its extensive pH adaptability, robust catalytic stability, and leaching resistance. The matrix effects of water constituents on the performance of S-doped FeWO4 were also investigated, and the results showed that a certain amount of Cl-, SO42-, NO3-, HCO3- and PO43- exhibited negligible effects on the degradation of SMX. Theoretical calculations corroborate that the distinctive spin-state reconstruction of Fe center in S-doped FeWO4 is advantageous for H2O2 decomposition. This discovery offers novel mechanistic insight into the enhanced catalytic activity of S doping in Fenton-like reactions and paves the way for expanding the application of FeWO4 in wastewater treatment.

Gamma-ray irradiation as an effective method for mitigating antibiotic resistant bacteria and antibiotic resistance genes in aquatic environments.

The prevalence of antibiotic resistance genes (ARGs) in municipal wastewater treatment plants (MWTPs) has emerged as a significant environmental concern. Despite advanced treatment processes, high levels of ARGs persist in the secondary effluent from MWTPs, posing ongoing environmental risks. This study explores the potential of gamma-ray irradiation as a novel approach for sterilizing antibiotic-resistant bacteria (ARB) and reducing ARGs in MWTP secondary effluent. Our findings reveal that gamma-ray irradiation at an absorbed dose of 1.6 kGy effectively deactivates all culturable bacteria, with no subsequent revival observed after exposure to 6.4 kGy and a 96-h incubation in darkness at room temperature. The removal efficiencies for a range of ARGs, including tetO, tetA, blaTEM-1, sulI, sulII, and tetW, were up to 90.5% with a 25.6 kGy absorbed dose. No resurgence of ARGs was detected after irradiation. Additionally, this study demonstrates a considerable reduction in the abundances of extracellular ARGs, with the transformation efficiencies of extracellular tetracycline and sulfadiazine resistance genes decreasing by 56.3-81.8% after 25.6 kGy irradiation. These results highlight the effectiveness of gamma-ray irradiation as an advanced and promising method for ARB sterilization and ARG reduction in the secondary effluent of MWTPs, offering a potential pathway to mitigate environmental risks associated with antibiotic resistance.

Modulation of ultrathin nanosheet structure and nitrogen defects in graphitic carbon nitride for efficient photocatalytic bacterial inactivation.

The efficient generation and utilization of ROSs is a key step in determining the achievement of safe drinking water by photocatalytic bacterial inactivation technology. Although graphitic carbon nitride (g-C3N4) serves as a green and promising photocatalyst for water disinfection, insufficient bacterial capturing capacity and serious charge recombination of pristine g-C3N4 extremely restrict its bactericidal activity. Herein, we develop a facile thermal exfoliation and thermal polymerization method to prepare the nitrogen-defective ultrathin g-C3N4 nanosheets (DUCN-500). Our results showed that ultrathin nanosheet structure greatly enhanced bacterial capturing capacity of g-C3N4 to increase the utilization efficiency of ROS, which contributed to the performance of DUCN-500 greatly outperforming bulk g-C3N4. The nitrogen defects increased ROS generation (·O2- and H2O2) by approximately 4.6 times, which was attributed to negative shift of the conduction band potential and rapid separation of charge carriers. The DUCN-500 could rapidly and completely inactivate Escherichia coli and Bacillus subtilis in real sewage under simulated solar irradiation, accompanied by good anti-interference capability and stability. Additionally, bacterial morphology destruction, the loss of antioxidant enzyme activity and the leakage of protein were proven to be the main mechanisms of photocatalytic sterilization. This study offers new insight into the rational design of efficient g-C3N4-based photocatalysts for water disinfection.

Epidemiological Survey of Hemoglobinopathies Based on Next-Generation Sequencing Platform in Hunan Province, China.

Objective: This study was aimed at investigating the carrier rate of, and molecular variation in, α- and ß-globin gene mutations in Hunan Province. Methods: We recruited 25,946 individuals attending premarital screening from 42 districts and counties in all 14 cities of Hunan Province. Hematological screening was performed, and molecular parameters were assessed. Results: The overall carrier rate of thalassemia was 7.1%, including 4.83% for α-thalassemia, 2.15% for ß-thalassemia, and 0.12% for both α- and ß-thalassemia. The highest carrier rate of thalassemia was in Yongzhou (14.57%). The most abundant genotype of α-thalassemia and ß-thalassemia was -α 3.7/αα (50.23%) and ß IVS-II-654/ß N (28.23%), respectively. Four α-globin mutations [CD108 (ACC>AAC), CAP +29 (G>C), Hb Agrinio and Hb Cervantes] and six ß-globin mutations [CAP +8 (C>T), IVS-II-848 (C>T), -56 (G>C), beta nt-77 (G>C), codon 20/21 (-TGGA) and Hb Knossos] had not previously been identified in China. Furthermore, this study provides the first report of the carrier rates of abnormal hemoglobin variants and α-globin triplication in Hunan Province, which were 0.49% and 1.99%, respectively. Conclusion: Our study demonstrates the high complexity and diversity of thalassemia gene mutations in the Hunan population. The results should facilitate genetic counselling and the prevention of severe thalassemia in this region.

Axial N Ligand-Modulated Ultrahigh Activity and Selectivity Hyperoxide Activation over Single-Atoms Nanozymes.

Learning and studying the structure-activity relationship in the bio-enzymes is conducive to the design of nanozymes for energy and environmental application. Herein, Fe single-atom nanozymes (Fe-SANs) with Fe-N5 site, inspired by the structure of cytochromes P450 (CYPs), are developed and characterized. Similar to the CYPs, the hyperoxide can activate the Fe(III) center of Fe-SANs to generate Fe(IV)O intermediately, which can transfer oxygen to the substrate with ultrafast speed. Particularly, using the peroxymonosulfate (PMS)-activated Fe-SANs to oxidize sulfamethoxazole, a typical antibiotic contaminant, as the model hyperoxides activation reaction, the excellent activity within 284 min-1 g-1 (catalyst) mmol-1 (PMS) oxidation rate and 91.6% selectivity to the Fe(IV)O intermediate oxidation are demonstrated. More importantly, instead of promoting PMS adsorption, the axial N ligand modulates the electron structure of FeN5 SANs for the lower reaction energy barrier and promotes electron transfer to PMS to produce Fe(IV)O intermediate with high selectivity. The highlight of the axial N coordination in the nanozymes in this work provides deep insight to guide the design and development of nanozymes nearly to the bio-enzyme with excellent activity and selectivity.

Enantioselective Michael/Hemiketalization Cascade Reactions between Hydroxymaleimides and 2-Hydroxynitrostyrenes for the Construction of Chiral Chroman-Fused Pyrrolidinediones.

In this paper, the organocatalytic asymmetric Michael addition/hemiketalization cascade reactions between hydroxymaleimides and 2-hydroxynitrostyrenes were developed, which provided a new protocol for building a chiral ring-fused chroman skeleton. This squaramide-catalyzed cascade reaction provided chiral chroman-fused pyrrolidinediones with three contiguous stereocenters in good to high yields (up to 88%), with excellent diastereoselectivities (up to >20:1 dr) and enantioselectivities (up to 96% ee) at −16 °C. Moreover, a scale-up synthesis was also carried out, and a possible reaction mechanism was proposed.

A bifunctional squaramide-catalysed enantioselective vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α,α-dicyanoalkenes.

An effective strategy for the stereoselective synthesis of spiro isoxazolone-cyclohexenimines was developed using a bifunctional squaramide-catalysed vinylogous Michael addition/cyclization cascade reaction of 4-unsaturated isoxazol-5-ones and α,α-dicyanoalkenes. The atom-economical cascade process can proceed smoothly under extremely low catalyst loading (1 mol%) and mild conditions, and the corresponding products were obtained in moderate to good yields (45% to 90%) and enantioselectivitites (51% to 96% ee). Meanwhile, the scale-up reaction and transformation of the products were also demonstrated.

Nitrogen/manganese oxides doped porous carbons derived from sodium butyl naphthalene sulfonate.

High-performance porous carbons have been prepared as supercapacitor electrode materials by co-doped with nitrogen and MnOx via a direct carbonization method, using sodium butyl naphthalene sulfonate (abbr. BNS-Na) as carbon source. It is believed that the in situ formed Na6(SO4)2(CO3) in the product would probably serve as temporary template for producing porous structures. The impacts of nitrogen/MnOx contents as well as the structures upon the capacitive performances were emphatically discussed. It indicates that introducing nitrogen and/or MnOx into the carbon matrix can remarkably improve their capacitive performances based on the cyclic voltammetry and galvanostatic charge-discharge measurements in 6 mol L(-1) KOH aqueous solution. The specific capacitances of doped carbons can reach up to ca. 167.0-241.8 F g(-1) compared with that of the undoped carbon of ca. 105.6 F g(-1). Of these samples, the carbon-Mn-1:30-N-1:15 sample co-doped with nitrogen and MnOx exhibits the highest specific capacitance and energy density up to 241.8 F g(-1) and 33.6 Wh kg(-1), respectively. In particular, these carbons also exhibit high intrinsic capacitances (i.e., capacitance per surface area) up to ca. 0.66-1.92 F m(-2).

High-performance supercapacitor based on nitrogen-doped porous carbon derived from zinc(II)-bis(8-hydroxyquinoline) coordination polymer.

Nitrogen-doped porous carbon electrodes with remarkable specific capacitance have been fabricated by the rational carbonization of zinc(II)-bis(8-hydroxyquinoline) (abbr. Znq(2)) coordination polymer, and heating treatment with CO(NH(2))(2). The experimental results demonstrate that the mass ratio of carbon precursor and CO(NH(2))(2) plays a key role in the formation of porous carbon with various nitrogen content as well as specific surface areas and pore structures. The cyclic voltammetry and galvanostatic charge-discharge measurements show that the capacitive performance has been remarkably improved by doping with nitrogen. The specific capacitance of 219.2 F g(-1) is achieved at the current density of 1 A g(-1) with nitrogen-doped porous carbon, increasing up to ca. 56.8% compared to that with pristine porous carbon. The nitrogen-doped porous carbon electrode exhibits enhance capacitance retention as ca. 45.2% at 20 A g(-1) as well as cycling stability (ca. 7.6% loss after 3000 cycles). The present carbonization method as well as the nitrogen-doping method for porous carbon from coordination polymer can enrich the strategies for the production of carbon-based electrodes materials in the application of electrochemical capacitors.

[Influencing factors on depression among medical staff in Hunan province under ordinal regression analysis].

OBJECTIVE: To understand the situation of depression and its related influencing factors among medical staff in Hunan province. METHODS: Data were collected through random sampling with multi-stage stratified cluster. Wilcoxon rank sum test, Kruskal-Wallis H test and Ordinal regression analysis were used for data analysis by SPSS 17.0 software. RESULTS: This survey was including 16,000 medical personnel with 14, 988 valid questionnaires and the effective rate was 93.68%. RESULTS: from the single factor analysis showed that factors as: level of the hospital grading, gender, education background, age, occupation, title, departments, the number of continue education, income, working overtime every week, the frequency of night work, the number of patients treated in the emergency room etc., had statistical significances (P < 0.05). Data from ordinal regression showed that the probabilities related to depression that clinicians and nurses suffering from were 1.58 times more than the pharmacists (OR = 1.58, 95%CI: 1.30 - 1.92). The probability among those whose income was less than 2000 Yuan/month was 2.19 times of the ones whose earned more than 3000 Yuan/month (OR = 2.19, 95%CI: 2.05 - 2.35). The higher the numbers of days with working overtime every week, the frequencies of night work, and the numbers of patients being treated at the emergency room, with more probabilities of the people with depression seen in our study. CONCLUSION: Depression seemed to be common among doctors and nurses. We suggested that the government need to increase the monthly income and to reduce the workload and intensity, lessen the overworking time, etc.

Preliminary results of combined carotid endarterectomy and off-pump coronary artery bypass grafting in patients with coexistent carotid and coronary artery diseases.

BACKGROUND: Coexistent carotid and coronary artery diseases are common and patients with them remain at a high risk for perioperative stroke or myocardial infarction after coronary bypass surgery. The aim of this study was to investigate the effect of combined carotid endarterectomy (CEA) and off-pump coronary artery bypass grafting (CABG) in patients with coexistent carotid and coronary artery diseases. METHODS: Between January 2002 and December 2007, consecutive patients with coexistent carotid and coronary artery diseases underwent one-stage unilateral CEA and off-pump CABG in Heart Institute of Nanjing First Hospital Affiliated to Nanjing Medical University. Perioperative complications were assessed and follow-up was carried out. RESULTS: A total of 51 cases of isolated off-pump CABG and unilateral CEA, including 34 right and 17 left, were performed. The mean blocked time of carotid artery in CEA was (25.5 +/- 7.0) minutes. The mean number of distal grafts per patient was 3.30 +/- 0.45. The mean ventilation time, intensive care unit stay, and postoperative hospital stay was (11.3 +/- 5.4) hours, (2.1 +/- 0.9) days, and (12.5 +/- 6.1) days respectively. None of the patients had stroke or myocardial infarct. There was one perioperative death due to acute cardiac failure, resulting in an operative mortality of 1.96%. Follow-up was completed for 47 patients (92.16%) with a mean follow-up of (39.5 +/- 12.5) months. None of the patients manifested stroke, new angina or newly developed cardiac infarct. No late death occurred. CONCLUSION: Combined CEA and off-pump CABG is a safe and effective procedure in selected patients with coexistent carotid and coronary artery diseases.

Development of an automated on-line pre-column derivatization procedure for sensitive determination of histamine in food with high-performance liquid chromatography-fluorescence detection.

An improved sensitive method was developed and validated for the determination of histamine in food samples by using automated on-line pre-column derivatization coupled with high performance liquid chromatography and fluorescence detection (HPLC-FLD). o-Phthaldialdehyde (OPA) was adopted as derivatization reagent, and a "sandwich" (OPA+histamine+OPA) aspiration mode for the automated on-line pre-column derivatization was found to efficiently enhance the method sensitivity and precision. Histamine in food samples was efficiently extracted with a methanol-phosphate buffer solution (50:50, v/v) at 60 degrees C for 30 min, and purified with Waters Oasis MCX solid-phase extraction (SPE) cartridge. The limit of quantification for this method is 0.2 mg/kg, which is very sensitive for histamine determination. With the "sandwich" injection program, 3.7% of relative standard deviation (RSD) was achieved by five replicative determinations of a sample blank spiked with 0.25 mg/kg histamine standard. Histamine in food samples such as fumitory skipjack and mackerel was analyzed with relative recoveries over 95% at spiking level of 150 mg/kg, as well as canned tuna fish and cheese with relative recoveries up to 98% at spiking levels of 0.50 and 5.0 mg/kg, respectively. The proposed method was validated with a sample from the Food Analysis Performance Assessment Scheme (FAPAS) as a standard certified material; and the results (140+/-6 mg/kg) agreed well with the assigned value (139 mg/kg).

[Expression of NF-kappa B in human bladder cancer and its clinical significance].

BACKGROUND & OBJECTIVE: Studies on solid cancer(such as breast cancer, hepatocellular cancer, pancreatic cancer) indicated that the abnormal expression of nuclear transcription factor Kappa B (NF-kappa B) regulates angiogenesis and cyclin-related genes. This study was designed to investigate the expression differences of NF-kappa B and its regulated genes between human primary transitional cell carcinoma(TCCs) of bladder and non-cancer bladder mucosa and its clinical significance. METHODS: Forty-three frozen sections including 30 bladder cancer and 13 non-cancer bladder mucosa were subjected to immunohistochemistry and nucleus staining for determining levels of NF-kappa B family and I kappa B alpha; Five paired cancer and non-cancer specimens were subjected to Western blot for analysis p65, an important subtype of NF-kappa B; Thirteen paired specimens were subjected to RT-PCR for determination mRNA levels of p50, p52, p65, c-Rel, RelB, I kappa B alpha, CyclinD1, IL-8. RESULTS: Expressions of p50, p52, p65, c-Rel, RelB, I kappa B alpha, CyclinD1, IL-8 mRNAs in bladder cancer were higher than that in non-cancer bladder mucosa (P < 0.01, P < 0.05, P < 0.01, P < 0.01, P < 0.05, P < 0.05, P < 0.05 and P < 0.05, respectively). Nucelus stainings of p50, p52, p65, c-Rel, RelB were also stronger in bladder cancer(P < 0.01, P < 0.01, P < 0.01, P < 0.01 and P < 0.01, respectively). Moreover, p65 was expressed more in cancer tissue than that in non-cancer mucosa evidenced by Western blot. In bladder cancer, the ranking score differences of p52, p65, c-Rel protein between lymphatic metastasis group and non-lymphatic metastasis group were statistically significant (P < 0.01, P < 0.01, P < 0.05, respectively). CONCLUSIONS: Compared to noncancer bladder mucosa, expressions of NF-kappa B family and its regulated genes in bladder cancer are markedly higher. NF-kappa B may be related to lymphatic metastasis.