Associations of polycyclic aromatic hydrocarbons mixtures with cardiovascular diseases mortality and all-cause mortality and the mediation role of phenotypic ageing: A time-to-event analysis.

The associations of polycyclic aromatic hydrocarbons (PAHs) with cardiovascular diseases (CVDs) and all-cause mortality are unclear, especially the joint effects of PAHs exposure. Meanwhile, no studies have examined the effect of phenotypic ageing on the relationship between PAHs and mortality. Therefore, this study aimed to investigate the independent and joint associations between PAHs and CVDs, all-cause mortality, and assess whether phenotypic age acceleration (PhenoAgeAccel) mediate this relationship. We retrospectively collected data of 11,983 adults from the National Health and Nutrition Examination Survey database. Firstly, Cox proportional hazards regression and restricted cubic splines were applied to evaluate the independent association of single PAH on mortality. Further, time-dependent Probit extension of Bayesian Kernel Machine Regression and quantile-based g-computation models were conducted to test the joint effect of PAHs on mortality. Then, difference method was used to calculate the mediation proportion of PhenoAgeAccel in the association between PAHs and mortality. Our results revealed that joint exposure to PAHs showed positive association with CVDs and all-cause mortality. By controlling potential confounders, 1-Hydroxynapthalene (1-NAP) (HR = 1.24, P = 0.035) and 2-Hydroxyfluorene (2-FLU) (HR = 1.25, P < 0.001) showed positive association with CVDs mortality, and they were the top 2 predictors (weight: 0.82 for 1-NAP, 0.14 for 2-FLU) of CVDs mortality. 1-NAP (HR = 1.15, P < 0.001) and 2-FLU (HR = 1.13, P < 0.001) also showed positive association with all-cause mortality, and they were also the top 2 predictors of all-cause mortality (weight: 0.66 for 1-NAP, 0.34 for 2-FLU). PhenoAgeAccel mediated the relationship between 1-NAP, 2-FLU and CVDs, all-cause mortality, with a mediation proportion of 10.00 % to 24.90 % (P < 0.05). Specifically, the components of PhenoAgeAccel including C-reactive protein, lymphocyte percent, white blood cell count, red cell distribution width, and mean cell volume were the main contributors of mediation effects. Our study highlights the hazards of joint exposure of PAHs and the importance of phenotypic ageing on the relationship between PAHs and mortality.

Identifying and predicting physical limitation and cognitive decline trajectory group of older adults in China: A data-driven machine learning analysis.

OBJECTIVE: This study aimed to utilize data-driven machine learning methods to identify and predict potential physical and cognitive function trajectory groups of older adults and determine their crucial factors for promoting active ageing in China. METHODS: Longitudinal data on 3026 older adults from the Chinese Longitudinal Healthy Longevity and Happy Family Survey was used to identify potential physical and cognitive function trajectory groups using a group-based multi-trajectory model (GBMTM). Predictors were selected from sociodemographic characteristics, lifestyle factors, and physical and mental conditions. The trajectory groups were predicted using data-driven machine learning models and dynamic nomogram. Model performance was evaluated by area under the receiver operating characteristics curve (AUROC), area under the precision-recall curve (PRAUC), and confusion matrix. RESULTS: Two physical and cognitive function trajectory groups were determined, including a trajectory group with physical limitation and cognitive decline (14.18 %) and a normal trajectory group (85.82 %). Logistic regression performed well in predicting trajectory groups (AUROC = 0.881, PRAUC = 0.649). Older adults with lower baseline score of activities of daily living, older age, less frequent housework, and fewer actual teeth were more likely to experience physical limitation and cognitive decline trajectory group. LIMITATION: This study didn't carry out external validation. CONCLUSIONS: This study shows that GBMTM and machine learning models effectively identify and predict physical limitation and cognitive decline trajectory group. The identified predictors might be essential for developing targeted interventions to promote healthy ageing.

Development of interpretable machine learning models associated with environmental chemicals to predict all-cause and specific-cause mortality：A longitudinal study based on NHANES.

Limited information is available on potential predictive value of environmental chemicals for mortality. Our study aimed to investigate the associations between 43 of 8 classes representative environmental chemicals in serum/urine and mortality, and further develop the interpretable machine learning models associated with environmental chemicals to predict mortality. A total of 1602 participants were included from the National Health and Nutrition Examination Survey (NHANES). During 154,646 person-months of follow-up, 127 deaths occurred. We found that machine learning showed promise in predicting mortality. CoxPH was selected as the optimal model for predicting all-cause mortality with time-dependent AUROC of 0.953 (95%CI: 0.951-0.955). Coxnet was the best model for predicting cardiovascular disease (CVD) and cancer mortality with time-dependent AUROCs of 0.935 (95%CI: 0.933-0.936) and 0.850 (95%CI: 0.844-0.857). Based on clinical variables, adding environmental chemicals could enhance the predictive ability of cancer mortality (P < 0.05). Some environmental chemicals contributed more to the models than traditional clinical variables. Combined the results of association and prediction models by interpretable machine learning analyses, we found urinary methyl paraben (MP) and urinary 2-napthol (2-NAP) were negatively associated with all-cause mortality, while serum cadmium (Cd) was positively associated with all-cause mortality. Urinary bisphenol A (BPA) was positively associated with CVD mortality.

Investigating predictors of progression from mild cognitive impairment to Alzheimer's disease based on different time intervals.

BACKGROUND: Mild cognitive impairment (MCI) is the early stage of AD, and about 10-12% of MCI patients will progress to AD every year. At present, there are no effective markers for the early diagnosis of whether MCI patients will progress to AD. This study aimed to develop machine learning-based models for predicting the progression from MCI to AD within 3 years, to assist in screening and prevention of high-risk populations. METHODS: Data were collected from the Alzheimer's Disease Neuroimaging Initiative, a representative sample of cognitive impairment population. Machine learning models were applied to predict the progression from MCI to AD, using demographic, neuropsychological test and MRI-related biomarkers. Data were divided into training (56%), validation (14%) and test sets (30%). AUC (area under ROC curve) was used as the main evaluation metric. Key predictors were ranked utilising their importance. RESULTS: The AdaBoost model based on logistic regression achieved the best performance (AUC: 0.98) in 0-6 month prediction. Scores from the Functional Activities Questionnaire, Modified Preclinical Alzheimer Cognitive Composite with Trails test and ADAS11 (Unweighted sum of 11 items from The Alzheimer's Disease Assessment Scale-Cognitive Subscale) were key predictors. CONCLUSION: Through machine learning, neuropsychological tests and MRI-related markers could accurately predict the progression from MCI to AD, especially in a short period time. This is of great significance for clinical staff to screen and diagnose AD, and to intervene and treat high-risk MCI patients early.

Damage Control Surgery Saves Patient with Gastric Lymphoma from Radical Gastrectomy.

The concept of damage control surgery was first introduced in the 1990s. It has great significance in the treatment for critically ill patients, which not only greatly improves survival rate, but also helps doctors avoiding misdiagnosis and mistreatment. Herein, we present a case of gastric perforation caused by neoplasm with critical condition of the patient. According to the concept of damage control surgery, the patient was subjected to perforation repair and tumor biopsy instead of conventional radical gastrectomy. Then, diffuse large B cell lymphoma was diagnosed on pathologic examination. After surgery, the patient received R-CHOP chemotherapy according to the clinical guidelines and is alive till now. Our experience might be helpful for understanding the value of damage control surgery in avoiding misdiagnosis and mistreatment for critical emergency patients. Key Words: Lymphoma, Stomach, Perforation, Damage control surgery.

Non-operative Treatment of Gastric Fistula after Splenectomy Combined with Pericardial Devascularisation in Portal Hypertension.

Portal hypertension may gradually lead to esophagogastric varices and splenomegaly in the decompensated stage of liver cirrhosis, which requires surgical treatment, if the disease worsens. Splenectomy with pericardial devascularisation is the routine surgery. One complex complication after splenectomy is upper gastric fistula which can seriously affect the perioperative recovery. Here, we present a case of a 51-year female patient, who recovered completely from non-operative treatment for gastric fistula after splenectomy and pericardial devascularisation. The occurrence of gastric fistula may be strongly related to preoperative preparation, intra-operative procedure and postoperative management. Therefore, personalised management is important for avoiding gastric fistula. Key Words: Gastric fistula, Splenectomy, Pericardial devascularisation, Portal hypertension.

Cross-interface transfer of polycyclic aromatic hydrocarbons (PAHs) in a shallow urban lake in Shanghai, China based on the fugacity model.

Shallow urban lakes are important urban ecosystems; however, these systems are subject to severe polycyclic aromatic hydrocarbons (PAHs) contamination. An understanding of the distribution and dynamics of PAHs in lakes is required to restore the functions of lake ecosystems and to ensure the ecological security of urban water sources. The Quantitative Water Air Sediment Interaction (QWASI) model and partition coefficient and fugacity fraction methods were applied to estimate the multimedia transfers of PAHs in Dianshan Lake, a typical shallow lake in Shanghai, China. In addition, some new concepts and methods related to PAH transfers were introduced. The results showed that while the gas-solid partition in the area remained in non-equilibrium, the influence of pollution sources tended to weaken. Atmospheric advection was the main source of PAHs to the lake, and a portion of the net loss of advection was transformed into total flux of cross-interface transfers, in which transport fluxes from air to water and from water to sediment were dominant, with a significant correlation between the two types of transfer. The large resuspension of high molecular weight (HMW)-PAHs occurred, possibly related to frequent hydrodynamic disturbances. Furthermore, this study explored the distribution of PAHs among different compartments and the seasonal variation of multimedia transfers. Sensitivity analysis showed that the model is remarkably sensitive to four parameters including temperature and advection. Monte Carlo uncertainty analysis verified that the simulation results were stable and reliable. The results can provide a theoretical basis for the monitoring and control of shallow lake pollution.

ß-Lactam Antibiotics Enhance the Pathogenicity of Methicillin-Resistant Staphylococcus aureus via SarA-Controlled Lipoprotein-Like Cluster Expression.

Methicillin-resistant Staphylococcus aureus (MRSA) resists nearly all ß-lactam antibiotics that have a bactericidal activity. However, whether the empirically used ß-lactams enhance MRSA pathogenicity in vivo remains unclear. In this study, we showed that a cluster of lipoprotein-like genes (lpl, sa2275 to sa2273 [sa2275-sa2273]) was upregulated in MRSA in response to subinhibitory concentrations of ß-lactam induction. The increasing expression of lpl by ß-lactams was directly controlled by the global regulator SarA. The ß-lactam-induced Lpls stimulated the production of interleukin-6 and tumor necrosis factor alpha in RAW 264.7 macrophages. The lpl deletion mutants (N315Δlpl and USA300Δlpl) decreased the proinflammatory cytokine levels in vitro and in vivo Purified lipidated SA2275-his proteins could trigger a Toll-like-receptor-2 (TLR2)-dependent immune response in primary mouse bone marrow-derived macrophages and C57BL/6 mice. The bacterial loads of N315Δlpl in the mouse kidney were lower than those of the wild-type N315. The ß-lactam-treated MRSA exacerbated cutaneous infections in both BALB/c and C57BL/6 mice, presenting increased lesion size; destroyed skin structure; and easily promoted abscess formation compared with those of the untreated MRSA. However, the size of abscesses caused by the ß-lactam-treated N315 was negligibly different from those caused by the untreated N315Δlpl in C57BL/6 TLR2-/- mice. Our findings suggest that ß-lactams must be used carefully because they might aggravate the outcome of MRSA infection compared to inaction in treatment.IMPORTANCE ß-Lactam antibiotics are widely applied to treat infectious diseases. However, certain poor disease outcomes caused by ß-lactams remain poorly understood. In this study, we have identified a cluster of lipoprotein-like genes (lpl, sa2275-sa2273) that is upregulated in the major clinically prevalent MRSA clones in response to subinhibitory concentrations of ß-lactam induction. The major highlight of this work is that ß-lactams stimulate the expression of SarA, which directly binds to the lpl cluster promoter region and upregulates lpl expression in MRSA. Deletion of lpl significantly decreases proinflammatory cytokine levels in vitro and in vivo The ß-lactam-induced Lpls enhance host inflammatory responses by triggering the Toll-like-receptor-2-mediated expressions of interleukin-6 and tumor necrosis factor alpha. The ß-lactam-induced Lpls are important virulence factors that enhance MRSA pathogenicity. These data elucidate that subinhibitory concentrations of ß-lactams can exacerbate the outcomes of MRSA infection through induction of lpl controlled by the global regulator SarA.

Virulence Determinants Are Required for Brain Abscess Formation Through Staphylococcus aureus Infection and Are Potential Targets of Antivirulence Factor Therapy.

Bacterial brain abscesses (BAs) are difficult to treat with conventional antibiotics. Thus, the development of alternative therapeutic strategies for BAs is of high priority. Identifying the virulence determinants that contribute to BA formation induced by Staphylococcus aureus would improve the effectiveness of interventions for this disease. In this study, RT-qPCR was performed to compare the expression levels of 42 putative virulence determinants of S. aureus strains Newman and XQ during murine BA formation, ear colonization, and bacteremia. The alterations in the expression levels of 23 genes were further confirmed through specific TaqMan RT-qPCR. Eleven S. aureus genes that persistently upregulated expression levels during BA infection were identified, and their functions in BA formation were confirmed through isogenic mutant experiments. Bacterial loads and BA volumes in mice infected with isdA, isdC, lgt, hla, or spa deletion mutants and the hla/spa double mutant strain were lower than those in mice infected with the wild-type Newman strain. The therapeutic application of monoclonal antibodies against Hla and SpA decreased bacterial loads and BA volume in mice infected with Newman. This study provides insights into the virulence determinants that contribute to staphylococcal BA formation and a paradigm for antivirulence factor therapy against S. aureus infections.

A multimedia fugacity model to estimate the fate and transport of polycyclic aromatic hydrocarbons (PAHs) in a largely urbanized area, Shanghai, China.

Increasing PAHs pollution is creating more complex urban pollution system. However, the availability of sufficient monitoring activities for PAHs in multicompartment and corresponding multi-interface migration processes is still not well understood. In this study, a Level III steady state fugacity model was validated to evaluate the detailed local variations, and mass fluxes of PAHs in various environmental compartments (i.e., air, soil, sediment, water, vegetation and organic film). This model was applied to a region of Shanghai in 2012 based on a large number of measured data and brings model predictions in 2020. The model results indicate that most of the simulated concentrations agreed with the observed values within one order of magnitude with a tendency of underestimation for vegetation. Direct emission is the main input pathway of PAHs entering the atmosphere, whereas advection is the main outward flow from Shanghai. Organic film was achieved the highest concentration of PAHs compared to other compartments up to 58.17 g/m3. The soil and sediment served as the greatest sinks of PAHs and have the longest retention time (2421.95-78642.09 h). Importantly, a decreasing trend of PAHs was observed in multimedia from 2012 to 2020 and the transfer flux from the air to vegetation to soil was the dominant pathways of BaP intermedia circulation processes. A sensitivity analysis showed that temperature was the most influential parameter, especially for Phe. A Monte Carlo simulation emphasized heavier PAHs were overpredicted in film and sediment, but lighter PAHs in air and water were generally underestimated.

Comparative analysis and characterization of Enterobacteria phage SSL-2009a and 'HK578likevirus' bacteriophages.

Enterobacteria phage SSL-2009a is a virulent bacteriophage with strong and abroad lytic ability against lots of engineering E. coli strains. In this study, we re-sequenced its whole genome and made a detail analysis on its genomic and proteomic characteristics according to the updated genomic sequence. The genome of SSL-2009a is a circular double-stranded DNA of 44,899 base pairs in length, with a 54.67% G + C content. A total of 67 open reading frames were predicted as protein coding sequences, 24 of which encode products highly homologous to known phage proteins. There are 10 promoters and 22 terminators identified in the genome of SSL-2009a, but no tRNA is found. SSL-2009a belongs to the 'HK578likevirus' genus of Siphoviridae. Comparative analyses indicated that other twelve phages share high homology with SSL-2009a at nucleotide and amino acid levels and also should be clustered into the same genus. In-depth analysis was performed to reveal the genomic, proteomic, and morphological features of these 'HK578likevirus' phages, which may promote our understanding of Enterobacteria phage SSL-2009a and the 'HK578likevirus' genus, even the biodiversity and evolution of bacteriophages.

Reconstruction of the Vancomycin-Susceptible Staphylococcus aureus Phenotype From a Vancomycin-Intermediate S. aureus XN108.

The emergence of vancomycin-intermediate Staphylococcus aureus (VISA) has raised healthcare concerns worldwide. VISA is often associated with multiple genetic changes. However, the relative contributions of these changes to VISA phenotypes are incompletely defined. We have characterized VISA XN108 with vancomycin MIC of 12 µg/ml. Genome comparison revealed that WalK(S221P), GraS(T136I), and RpoB(H481N) mutations possibly contributed to the VISA phenotype of XN108. In this study, the above mutations were stepwise cured, and the phenotypes between XN108 and its derivates were compared. We constructed four isogenic mutant strains, XN108-WalK(P221S) (termed as K65), XN108-GraS(I136T) (termed as S65), XN108-RpoB(N481H) (termed as B65), and XN108-WalK(P221S)/GraS(I136T) (termed as KS65), using the allelic replacement experiments with the native alleles derived from a vancomycin-susceptible S. aureus isolate DP65. Antimicrobial susceptibility test revealed K65 and S65 exhibited decreased vancomycin resistance, whereas B65 revealed negligibly differed when compared with the wild-type XN108. Sequentially introducing WalK(P221S) and GraS(I136T) completely converted XN108 into a VSSA phenotype. Transmission electronic microscopy and autolysis determination demonstrated that cell wall thickening and decreasing autolysis were associated with the change of vancomycin resistance levels. Compared with XN108, K65 exhibited 577 differentially expressed genes (DEGs), whereas KS65 presented 555 DEGs. Of those DEGs, 390 were common in K65 and KS65, including those upregulated genes responsible for citrate cycle and bacterial autolysis, and the downregulated genes involved in peptidoglycan biosynthesis and teichoic acid modification. In conclusion, a VSSA phenotype could be completely reconstituted from a VISA strain XN108. WalK(S221P) and GraS(T136I) mutations may work synergistically in conferring vancomycin resistance in XN108.

A novel SigB(Q225P) mutation in Staphylococcus aureus retains virulence but promotes biofilm formation.

Staphylococcus aureus is an important pathogen that produces abundant virulence factors, which cause various diseases that burden human health worldwide. The stress response regulon called sigma factor B (SigB) is a well-characterized global regulator that is involved in the regulation of S. aureus virulence, pigmentation, and biofilm formation. However, the regulatory network upon SigB in S. aureus is incompletely described. Here, we identified a novel substitution mutation, SigB(Q225P), which contributed the nonpigmented phenotype of S. aureus. The S. aureus mutant carrying SigB(Q225P) substitution lacks staphyloxanthin, a key virulence factor in protecting bacteria from host-oxidant killing, but retains bacterial pathogenicity with pleiotropic alterations in virulence factors, resulting in similar lethality and abscess formation ability in animal models. We also reported the SigB(Q225P) promotion of biofilm formation in S. aureus. Real-time quantitative polymerase chain reaction (RT-qPCR) revealed that the expression of nuc gene, which encodes thermonuclease, was significantly downregulated, resulting in accumulation of eDNA in the biofilm of SigB(Q225P) mutant strain. LacZ reporter assay showed that SigB(Q225P) influenced the activity of nuc promoter. Furthermore, electrophoretic mobility shift assay (EMSA) and Bio-layer interferometry (BLI) assay revealed that both SigB and SigB(Q225P) proteins could directly bind to nuc gene promoter; however, the binding activity decreased for SigB(Q225P). Our data renewed the understanding of the relationship between S. aureus golden pigment and its virulence and suggested that a single substitution mutation in SigB might enhance the biofilm formation of S. aureus by directly downregulating nuc expression.

Enhanced adsorption of ciprofloxacin by KOH modified biochar derived from potato stems and leaves.

Potato stems and leaves biochar (PB) was prepared by pyrolysis at a temperature of 500°C under anoxic conditions. In order to strengthen the adsorption capacity, biochar was modified with alkaline solution (alkali modified biochar, APB). Two kinds of biochars were adopted as adsorbents to remove ciprofloxacin (CIP) from aqueous solution. The adsorption behavior of CIP onto biochar before and after alkali modified including adsorption kinetics and isotherms were investigated. The effects of different factors (equilibrium time, pH, temperature and initial concentration) during the adsorption process were also investigated. Biochar samples were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), and nitrogen adsorption-desorption isotherm. The results showed that the alkali treated biochar possessed more mesopores than raw biochar, and accordingly exhibited a more excellent adsorption performance (23.36 mg·g-1) than raw biochar. Hydrophobic interaction, hydrogen-bonding interaction, electrostatic interaction, and π - π interaction were the adsorption mechanisms for CIP uptake onto the two adsorbents.

Acute Swine Model for Assessing Biocompatibility of Biomedical Interface Materials.

We established an acute animal model for early, straightforward, and reproducible assessment of a biocompatible material interface. Bilateral femoral artery-to-vein shunts were created in 12 pigs: two tubes per shunt, the left two coated and the right two uncoated. We evaluated two groups: uncontrolled flow (UF; shunt flow unregulated) and controlled flow (CF; shunt flow ∼50 mL/min). For each case on each side, two shunts were evaluated: one for 1 h and the other for 3 h. Arterial blood gas and complete blood count were recorded at baseline, 1, and 3 h. Mean shunt flows were 532 ± 88 mL/min UF and 52 ± 8 mL/min CF. Differences in flow were much smaller in CF (0.5 mL/min; 1% of mean flow) than UF (24.8 mL/min; 5% of mean flow). In UF, significant changes occurred: in pH, from start of shunting through 1 h; in pO2 and pCO2, from start through 3 h. This swine model using bilateral femoral shunts with controlled blood flow provides a reliable, reproducible, easily implemented method by which to evaluate biocompatibility of device coatings at an early stage of investigation.

Safe Staphylococcal Platform for the Development of Multivalent Nanoscale Vesicles against Viral Infections.

Many viruses often have closely related yet antigenically distinct serotypes. An ideal vaccine against viral infections should induce a multivalent and protective immune response against all serotypes. Inspired by bacterial membrane vesicles (MVs) that carry different protein components, we constructed an agr locus deletion mutant of the Staphylococcus aureus strain (RN4220-Δagr) to reduce potential toxicity. Nanoscale vesicles derived from this strain (ΔagrMVs) carry at least four major components that can deliver heterologous antigens. These components were each fused with a triple FLAG tag, and the tagged proteins could be incorporated into the ΔagrMVs. The presentation levels were (3.43 ± 0.73)%, (5.07 ± 0.82)%, (2.64 ± 0.61)%, and (2.89 ± 0.74)% of the total ΔagrMV proteins for Mntc-FLAG, PdhB-FLAG, PdhA-FLAG, and Eno-FLAG, respectively. With two DENV envelope E domain III proteins (EDIIIconA and EDIIIconB) as models, the DENV EDIIIconA and EDIIIconB delivered by two staphylococcal components were stably embedded in the ΔagrMVs. Administration of such engineered ΔagrMVs in mice induced antibodies against all four DENV serotypes. Sera from immunized mice protected Vero cells and suckling mice from a lethal challenge of DENV-2. This study will open up new insights into the preparation of multivalent nanosized viral vaccines against viral infections.

A novel biochar derived from cauliflower (Brassica oleracea L.) roots could remove norfloxacin and chlortetracycline efficiently.

The biochar was prepared by pyrolyzing the roots of cauliflowers, at a temperature of 500 °C under oxygen-limited conditions. The structure and characteristics of the biochar were examined using scanning electron microscopy, an energy dispersive spectrometer, a zeta potential analyzer, and Fourier transform infrared spectroscopy. The effects of the temperature, the initial pH, antibiotic concentration, and contact time on the adsorption of norfloxacin (NOR) and chlortetracycline (CTC) onto the biochar were investigated. The adsorption kinetics of NOR and CTC onto the biochar followed the pseudo-second-order kinetic and intra-particle diffusion models. The adsorption isotherm experimental data were well fitted to the Langmuir and Freundlich isotherm models. The maximum adsorption capacities of NOR and CTC were 31.15 and 81.30 mg/g, respectively. There was little difference between the effects of initial solution pH (4.0-10.0) on the adsorption of NOR or CTC onto the biochar because of the buffering effect. The biochar could remove NOR and CTC efficiently in aqueous solutions because of its large specific surface area, abundant surface functional groups, and particular porous structure. Therefore, it could be used as an excellent adsorbent material because of its low cost and high efficiency and the extensive availability of the raw materials.

TiO2 supported on reed straw biochar as an adsorptive and photocatalytic composite for the efficient degradation of sulfamethoxazole in aqueous matrices.

Heterogeneous photocatalysis namely titanium dioxide supported on reed straw biochar (acid pre-treated) (TiO2/pBC) was synthesized by sol-gel method. The morphology, surface area and structure of TiO2/pBC were characterized by scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET), and X-ray diffraction (XRD). Low calcination condition maintained the structure of biochar completely and prevented the agglomeration of TiO2 particles. Due to the combination of adsorption and photocatalysis, TiO2/pBC performed higher removal efficiency of sulfamethoxazole (SMX) than pure TiO2 powder under UV light irradiation. The photocatalytic degradation (PCD) of SMX was also studied with the water collected from the Yellow River. Three high concentration inorganic anions (Cl-, NO3-, SO42-) of the river exerted certain degree of detrimental effects on the contaminant degradation. TiO2/pBC showed stable photocatalytic activity after five sequential PCD cycles. The biochar was able to promote further PCD on TiO2 by adsorbing SMX and intermediates thereby prolonging the separation lifetime of electrons (e-) and valence band hole (h+). The transformation intermediates of SMX were identified and three possible degradation reactions of hydroxylation, opening of isoxazole ring and cleavage of SN bond might occur during the PCD of SMX.

Distribution, sources and ecological risk of polycyclic aromatic hydrocarbons in the estuarine-coastal sediments in the East China Sea.

Polycyclic aromatic hydrocarbons (PAHs), total organic carbon (TOC) and black carbon (BC) in the estuarine-coastal areas of the East China Sea (ECS) were investigated. The results showed that ∑PAH concentrations ranged from 61 to 355 ng g-1 with a mean value of 146 ng g-1. The contents of TOC and BC were in the range of 1.31-7.23 mg g-1 and 0.52-5.60 mg g-1, respectively. Data analyses showed that PAH concentrations had a positive linear relationship with TOC and with BC. In addition, the grain size of silts and clays had significant influence on the PAHs of sediments. These physicochemical properties as well as coastal currents, especially the trapping effect of the Taiwan Warm Current and the Zhejiang Fujian Coastal Current, played important roles in determining the spatial distribution of PAHs in the ECS. The estimated deposition flux of PAHs was 106 t per year in the study area. Source apportionment showed that these PAHs mainly originated from oil sources, and the combustion of liquid fossils and coal/wood.

Molecular and Phenotypic Characterization Revealed High Prevalence of Multidrug-Resistant Methicillin-Susceptible Staphylococcus aureus in Chongqing, Southwestern China.

Methicillin-susceptible Staphylococcus aureus (MSSA) accounts for ∼40% of staphylococcal infections in China. However, the molecular characterization of MSSA is not well described. In this study, 124 MSSA strains collected in 2013 from a comprehensive teaching hospital in Chongqing, Southwestern China, were subjected to antibiotics susceptibility testing and molecular typing, including multilocus sequence typing, staphylococcal protein A (spa) gene typing, accessory gene regulator (agr) typing, pulsed-field gel electrophoresis (PFGE) typing, Panton-Valentine leukocidin (pvl) gene detection, and antibiotic-resistant gene detection. MSSA strains exhibited high genetic heterogeneity. A total of 10 PFGE groups, 26 sequence types, and 47 spa types were identified. Type I (62.9%) was the most frequent agr type, followed by type II (15.3%), type IV (11.3%), and type III (10.5%). The prevalence of pvl genes was 27.4% (34/124). Notably, 44.4% (55/124) of MSSA strains were multidrug resistance (MDR), and MDR isolates were mostly resistant to penicillin, erythromycin, and clindamycin. The resistance gene blaZ was present in 84.7% of strains, ermC was present in 85.5% of strains, ermA was present in 28.2% of strains, tetK was present in 16.1% of strains, tetM was present in 6.5% of strains, and aacA-aphD was present in 2.6% of strains. These data demonstrated the high prevalence of MDR MSSA in Chongqing, thereby indicating the need to control MSSA infection.