Microalgae-enhanced bioremediation of Cr(VI) ions using spent coffee ground-derived magnetic biochar MoS2-Ag composites.

Composites of magnetic biochar derived from spent coffee grounds were prepared using MoS2 decorated by plasmonic silver nanoparticles (MoS2-Ag), which were used for the bioremediation Cr6+ ions. The composites were characterized by electron microscopy, X-ray diffraction, Raman, and UV-VIS spectroscopy. The bioremediation of Cr6+ ions was enhanced almost two times compared to microalgae, Spirulina maxima. Such an increased activity is attributed to heterojunction formation of Biochar@MoS2-Ag composite due to the synergetic effects of surface plasmon resonance of AgNPs inducing amplified local electric field, thus simultaneously increasing the absorption of MoS2 under visible or near-infrared light. The combination of Biochar@MoS2-Ag and Spirulina maxima powder was effective for the separation (microalga-based absorption and accumulation of Cr6+ ions) of photo-induced carriers (composite-assisted to breakdown Cr6+ ions). This study offers efficient eco-friendly treatment of Cr6+ ions by reporting the first enhanced bioremediation of Cr(VI) ions by microalgae using MoS2-Ag-modified biochar obtained from consumed coffee grounds.

Community Mobilization to Reduce Drug Use, Quang Ninh, Vietnam.

Objectives. We implemented an intervention to reduce drug use in an urban commune in northern Vietnam. Methods. We encouraged the intervention commune to accept responsibility for developing their own intervention strategies based on a community mobilization model used in southern, rural China. We selected a comparison commune, which had demographic characteristics and a drug history similar to the intervention commune. The 2-year incidence of new drug users was estimated retrospectively in the intervention and comparison communes between baseline (2003) and follow-up (2009). Results. Increased incidence of new (noninjecting) drug users between 2003 and 2009 in the intervention commune was lower than that in the comparison commune, and these participants expressed more positive attitudes toward local authority and people with drug use and HIV/AIDS. Increased condom use during last intercourse with female sex workers and with female casual partners was observed in the intervention commune. HIV prevalence and positive opioid tests decreased more in the intervention commune. Conclusions. Our results suggested that the community mobilization had a positive influence in the intervention commune.

Core-shell Au@ZIF-67-based pollutant monitoring of thiram and carbendazim pesticides.

A sensitive and stable substrate plays a vital role in the Raman spectroscopic techniques as an analytical method for detecting pesticides effectively from the environment. Enhancing signals from nanoparticles are weak and inconsistent in repeatability since analytes tend to degrade quickly under laser exposure. Herein, a novel substrate of Au@ZIF-67 is prepared on octahedral AuNPs by trapping pesticide molecules with small three-dimensional volumes by the flexibility of ZIF-67 for rapid detection with high sensitivity and stability. The two types of thiram and carbendazim pesticides, which are environmental pollutants that affect biodiversity, were successfully absorbed in Au@ZIF-67 nanostructures by adsorption-desorption equilibrium for analytical purposes in Raman spectroscopy. Spectra calculations of the thiram and carbendazim molecules on 8 atoms of Au using DFT were compared with the experimental data. The SERS enhancement factors for thiram and carbendazim were estimated to be 1.91 × 108 and 3.12 × 108, respectively, with the LOD values of trace amounts of ∼10-10 mol L-1. The novel substrate of Au@ZIF-67 is a propitious platform for detecting thiram and carbendazim in trace amounts, providing a helpful strategy for detecting residues with high performance in the environment at the laboratory and practical scales.

Transparent Oil-Water Separating Spiky SiO2 Nanoparticle Supramolecular Polymer Superhydrophobic Coatings.

A potential application of spiky SiO2 nanoparticles (NPs) with tubular and rough surfaces is investigated as superhydrophobic coatings, for their unique transparent, fluorinate-free, and environmentally friendly properties. This study demonstrates a facile method for the successful fabrication of superhydrophobic coatings and SiO2 @polydimethylsiloxane (PDMS) using spiky SiO2 NPs, N-coordinated boroxines, and PDMS. Combined with spray coating technology, this method of superhydrophobic coating can be simply applied to both hydrophilic and hydrophobic surfaces, including wood, fabric, glass, metal, sponge, and paper. The nanocomposite coating on the glass surface showed both excellent superhydrophobicity and high transparency, with a contact angle of 165.4 ± 1.0° and 96.93% transmittance at 550 nm, respectively. SiO2 @PDMS-modified glass substrate is found to be resilient to UV irradiation, water, and high temperature treatments at ambient conditions. Experimental data demonstrated that the simple but effective combination of N-boroxine-PDMS and spiky SiO2 NPs produces a layered coating material that exhibits many good integrated surface properties, including stability, transparency, superhydrophobicity, and oil-water separation.

Photothermal plasmonic microballs for non-contact single-cell calcium ionophore delivery in heterogeneous cells.

Hierarchical plasmonic nanostructures comprising gold nanorod (AuNR)-covered microballs via syringe-injection reduction show good potential for selective single-cell calcium ionophore (A23187) delivery and apoptosis induction in heterogenous cancer cells.

Influence of liposomal formulation variables on the interaction with Candida albicans in biofilm; a multivariate approach.

Candida albicans is a species commonly associated with biofilm formation. The aim of this study was to identify liposomal formulation variables influencing the adhesion of liposomes to C. albicans in biofilm. C. albicans was grown on microtiter plates. Charged liposomes containing a fluorescent phospholipid (fatty acid labeled) were adsorbed onto biofilms of C. albicans in the wells. The adsorption was quantified by fluorescence measurements. Statistical experimental design and multivariate evaluation were used in the studies. The liposomal formulation factors investigated were the type of the main phospholipid (egg-PC, DMPC, and DPPC), the amount of charged component in the liposomes, and the type of the charged lipid (diacyl-TAP, DC-chol, diacyl-PA, diacyl-PG, diacyl-PS, and PI). Full factorial mixed levels designs were created. Saturated positively charged liposomes, with diacyl-TAP as the charged component and a low level of positive charge, was found to be the best choice for interaction with C. albicans. When formulating negatively charged liposomes, liposomes with DPPC as the main lipid adsorbed significantly better than liposomes with egg-PC. The amount of charge and the nature of the charged component were not found to influence the adsorption of the negatively charged liposomes to C. albicans. No synergy was detected between any of the formulation variables studied.

Spectroscopic analysis of microplastic contaminants in an urban wastewater treatment plant from Seoul, South Korea.

In this study, a systematic multi-spectroscopic analysis of microplastics (MPs) sampled from a metropolitan area of Seoul was undertaken to elevate understanding of the role of wastewater treatment plants (WWTPs) in eliminating suspended contaminants including MPs before releasing the effluent water into the environment. We analyzed pollutants in influent and effluent samples from a WWTP in Seoul, South Korea. Spectroscopic and microscopic methods were used to analyze MPs. Fourier-transform infrared (FT-IR) spectroscopy in the wavenumber region between 4000 and 715 cm-1 was employed to estimate the abundance of MPs in wastewater. Stereomicroscope images and Nile red staining were used to facilely identify MPs in both influents and effluents to compare the results with those of FT-IR data. Hyperspectral imaging could identify MPs in the influent sample with the reflection method at 400-900 nm. Our preliminary results indicate that the most observed MPs after the wastewater were filtered by a 45 µm stainless steel mesh filter were polyethylene (PE) and polypropylene (PP). The total number of the prevalent MPs in influent samples decreased significantly. Nanostructure particles could be found by field-emission scanning electron microscopy (FE-SEM). Our combined multi-spectroscopic study should be helpful to provide a guideline for the rapid spectroscopic analysis of freshwater in the Han River, Seoul, South Korea.

Effect of Vitamin D supplementation to reduce respiratory infections in children and adolescents in Vietnam: A randomized controlled trial.

BACKGROUND: It is uncertain whether vitamin D can reduce respiratory infection. OBJECTIVE: To determine whether vitamin D supplementation reduces influenza and other upper viral respiratory tract infections. METHODS: A total of 1300 healthy children and adolescents between the ages of 3 and 17 years were randomized to vitamin D (14 000 U weekly) or placebo for 8 months in Vietnam. The primary outcome was reverse transcriptase (RT)-PCR-confirmed influenza infection, and the coprimary outcome was multiplex PCR-confirmed non-influenza respiratory viruses. Participants, caregivers, and those assessing outcomes were blinded to group assignment. RESULTS: A total of 650 children and adolescents were randomly assigned to vitamin D and 650 to placebo. The mean baseline serum 25-hydroxyvitamin D levels were 65.7 nmol/L and 65.2 nmol/L in the intervention and placebo groups, respectively, with an increase to 91.8 nmol/L in the vitamin D group and no increase, 64.5 nmol/L, in the placebo group. All 1300 participants randomized contributed to the analysis. We observed RT-PCR-confirmed influenza A or B occurred in 50 children (7.7%) in the vitamin D group and in 43 (6.6%) in the placebo group (hazard ratio [HR]: 1.18, 95% CI: 0.79-1.78). RT-PCR-confirmed non-influenza respiratory virus infection occurred in 146 (22.5%) in the vitamin D group and in 185 (28.5%) in the placebo group (hazard ratio [HR]: 0.76, 95% CI: 0.61-0.94). When considering all respiratory viruses, including influenza, the effect of vitamin D in reducing infection was significant, HR: 0.81, 95% CI: 0.66-0.99. CONCLUSION: Vitamin D supplementation did not reduce the incidence of influenza but moderately reduced non-influenza respiratory viral infection.

Epidemiological, Serological, and Virological Features of Dengue in Nha Trang City, Vietnam.

Vietnam is endemic for dengue. We conducted a series of retrospective and prospective studies to characterize the epidemiology of dengue and population mobility patterns in Nha Trang city, Vietnam, with a view to rational design of trials of community-level interventions. A 10-year time series of dengue case notifications showed pronounced interannual variability, as well as spatial heterogeneity in ward-level dengue incidence (median annual coefficient of variation k = 0.47). Of 451 children aged 1-10 years enrolled in a cross-sectional serosurvey, almost one-third had evidence of a past dengue virus (DENV) infection, with older children more likely to have a multitypic response indicative of past exposure to ≥ 1 serotype. All four DENV serotypes were detected in hospitalized patients during 8 months of sampling in 2015. Mobility data collected from 1,000 children and young adults via prospective travel diaries showed that, although all ages spent approximately half of their daytime hours (5:00 am-9:00 pm) at home, younger age groups (≤ 14 years) spent a significantly greater proportion of their time within 500 m of home than older respondents. Together these findings inform the rational design of future trials of dengue preventive interventions in this setting by identifying 1) children < 7 years as an optimal target group for a flavivirus-naive serological cohort, 2) children and young adults as the predominant patient population for a study with a clinical end point of symptomatic dengue, and 3) substantial spatial and temporal variations in DENV transmission, with a consequent requirement for a trial to be large enough and of long enough duration to overcome this heterogeneity.

Effect of hydroxypropyl-beta-cyclodextrin-complexation and pH on solubility of camptothecin.

The influence of both pH and complexation by hydroxypropyl-beta-cyclodextrin (HP-beta-CD) on the overall solubility of camptothecin (CPT) was studied, with particular focus on the equilibrium between its lactone- and carboxylate-form. Phase solubility studies at therapeutically relevant pH values (pH 5.5-7.0) and physiologically acceptable HP-beta-CD-concentrations (0-25% (w/v)) were performed, and amounts of solubilized CPT quantified by HPLC. The solubility of CPT increased with both increasing pH and HP-beta-CD-concentration. The apparent complexation constant (KC) decreased with increasing pH (245 M(-1) at pH 5.5; 184 M(-1) at pH 7.0). The lactone-carboxylate equivalence point shifted from a pH value of 6.8-7.0 and 7.1 with 0, 10 and 25% HP-beta-CD, respectively. The lactone-carboxylate-ratios from the equilibrium study were applied to the phase-solubility data, and the lactone- and carboxylate concentrations at 0, 10 and 25% HP-beta-CD calculated. Separate complexation constants (KC) for the carboxylate-CPT and lactone-CPT could thus be derived, and found to be 113 +/- 7 and 260 +/- 18 M(-1), respectively. This allows the prediction of amounts of both lactone- and carboxylate-CPT solubilized at any HP-beta-CD concentration and pH-combination.

Risk factors for human infection with avian influenza A H5N1, Vietnam, 2004.

To evaluate risk factors for human infection with influenza A subtype H5N1, we performed a matched case-control study in Vietnam. We enrolled 28 case-patients who had laboratory-confirmed H5N1 infection during 2004 and 106 age-, sex-, and location-matched control-respondents. Data were analyzed by matched-pair analysis and multivariate conditional logistic regression. Factors that were independently associated with H5N1 infection were preparing sick or dead poultry for consumption < or =7 days before illness onset (matched odds ratio [OR] 8.99, 95% confidence interval [CI] 0.98-81.99, p = 0.05), having sick or dead poultry in the household < or =7 days before illness onset (matched OR 4.94, 95% CI 1.21-20.20, p = 0.03), and lack of an indoor water source (matched OR 6.46, 95% CI 1.20-34.81, p = 0.03). Factors not significantly associated with infection were raising healthy poultry, preparing healthy poultry for consumption, and exposure to persons with an acute respiratory illness.