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•Zn-S catalyst improves DB22 decolonization and mineralization rate by heterogeneous catalytic ozonation.•Zn, Ca constituents in Zn-S improve OH* generation in heterogeneous catalytic ...ozonation of DB22.•DB22′s mineralization by Zn-S catalytic ozonation was highest in alkaline condition.•Mineralization kinetic of DB22 follows pseudo-first order kinetic model.
This study developed a low cost catalyst, namely, zinc slag (Zn-S) for the ozonation process of Direct Black 22 (DB22) from aqueous solutions. Among five different kind of low cost metal slags including Fe-S, Cu-S, Cd-S, Pb-S and Zn-S, the Zn-S slag was selected as an efficient catalyst in this study. Zn-S contained mainly zinc (Zn) and calcium (Ca) discharged from zinc slag waste in Vietnam. It was found that Zn-S could effectively decolonize and mineralize DB22 through heterogeneous catalytic ozonation. The degradation kinetic of DB22 followed the pseudo-first order model. The best removal efficiency of DB22 (Zn-S/O3/H2O2 (76%) > Zn-S/O3 (69%) > O3/H2O2 (66%) > O3 (55% for COD) occurred at pH 11 for heterogeneous catalytic ozonation processes with Zn-S as the catalyst as well as ozone alone and perozone processes due to fast decomposition of O3 in alkaline solution to generate powerful and non-selective OH radicals. An increase in decolonization and mineralization rate was observed when increasing the Zn-S dosage from 0.125 g/L to 0.75 g/L for Zn-S/O3 and 0.125 g/L to 1.0 g/L for Zn-S/O3/H2O2. The K values of the pseudo-first order model followed the same sequence as mineralization rates of DB22 in term of COD removal. Ca and Zn constituents in the Zn-S catalyst contributed to the increase in O3 decomposition and improvement of reaction rate with H2O2. Subsequently, the degradation of DB22 by the ozonation process with Zn-S catalyst was enhanced through the enrichment mechanism of hydroxyl radicals (*OH) and surface adsorption. The degradation mechanism of DB22 by hydroxyl radicals was surely affirmed by tests with the decrease in degradation percentage of DB22 in case of the presence t-butanol, Cl− and CO32−.
This study presents the removal of phosphate from aqueous solution using a new silver nanoparticles-loaded tea activated carbon (AgNPs-TAC) material. In order to reduce costs, the tea activated ...carbon was produced from tea residue. Batch adsorption experiments were conducted to evaluate the effects of impregnation ratio of AgNPs and TAC, pH solution, contact time, initial phosphate concentration and dose of AgNPs-AC on removing phosphate from aqueous solution. Results show that the best conditions for phosphate adsorption occurred at the impregnation ratio AgNPs/TAC of 3% w/w, pH 3, and contact time lasting 150 min. The maximum adsorption capacity of phosphate on AgNPs-TAC determined by the Langmuir model was 13.62 mg/g at an initial phosphate concentration of 30 mg/L. The adsorption isotherm of phosphate on AgNPs-TAC fits well with both the Langmuir and Sips models. The adsorption kinetics data were also described well by the pseudo-first-order and pseudo-second-order models with high correlation coefficients of 0.978 and 0.966, respectively. The adsorption process was controlled by chemisorption through complexes and ligand exchange mechanisms. This study suggests that AgNPs-TAC is a promising, low cost adsorbent for phosphate removal from aqueous solution.
Management of multidrug-resistant tuberculosis (MDR-TB) is a significant challenge to the global healthcare system due to the complexity and long duration of the MDR-TB treatment. This study analyzed ...the safety of patients on longer injectable-based MDR-TB treatment regimens using active pharmacovigilance data.
We conducted an observational, prospective study based on active pharmacovigilance within the national TB program. A total of 659 MDR-TB patients were enrolled and followed up at 9 TB- hospitals in 9 provinces of all 3 regions in Vietnam between 2014 and 2016. Patients received a treatment regimen (standardized or individualized) based on their drug susceptibility test result and their treatment history. Baseline and follow-up information was collected at the start and during treatment. Adverse events (AE) were defined and classified as serious adverse events (SAEs) or otherwise. Multivariate Cox regression following the Iterative Bayesian Model Averaging algorithm was performed to identify factors associated with AE occurrence.
Out of 659 patients assessed, 71.3% experienced at least one AE, and 17.5% suffered at least one SAE. The most common AEs were gastrointestinal disorders (38.5%), arthralgia (34.7%), and psychiatric disorders (30.0%). The proportion of patients with nephrotoxicity and hearing loss or vestibular disorders were 7.4% and 15.2%, respectively. 13.1% of patients required modifications or interruption of one or more drugs. In 77.7% of patients, treatment was completed successfully, while 9.3% lost to follow-up, in 3.0% treatment failed, and 7.4% died. Some significant risk factors for nephrotoxicity included diabetes mellitus (HR = 8.46 1.91-37.42), renal dysfunction (HR = 8.46 1.91-37.42), alcoholism (HR = 13.28 5.04-34.99), and a higher average daily dose of injectable drugs (HR = 1.28 1.14-1.43).
While a majority of patients on the longer injectable-based regimens experienced non-serious AEs during MDR-TB treatment, one in six patients experienced at least an SAE. Active TB drug-safety monitoring is useful to understand the safety of MDR-TB treatment and explore the risk factors for toxicity. All-oral, shorter MDR-TB regimens might be able to reduce the inconvenience, discomfort, and toxicity of such regimens and increase adherence and likelihood of successful completion.
Objective:
To assess the effectiveness of the presurgical nasoalveolar molding appliance among infants with unilateral cleft lip and palate.
Methods:
In this prospective study, 95 pairs of casts of ...infants with unilateral cleft lip and palate treated by presurgical nasoalveolar molding were selected at the Children’s Hospital 1 at Ho Chi Minh City, Vietnam. The average time of treatment was 3 months. All casts were scanned and measured using 3-dimensional technology before and after treatment. Paired t tests were applied for comparisons.
Results:
There was a statistically significant increase in the nostril height in cleft side (P < .001), decrease in the nostril width and columella angle (P < .001), and decrease in cleft width and midline deviation (P < .001) after treatment with presurgical nasoalveolar molding appliance.
Conclusions:
Nasoalveolar molding appliance is effective in improving the morphology of nostril and maxillary alveolar. Understanding this helps orthodontists and surgeons in treatment outcome expectations.
The degradation of MB on TiO2/BNNS NRs glass substrate was detected by Raman spectroscopy under UV irradiation (254 nm) in the time range of 0–50 min.
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•Boron nitride nanosheets ...decorated titanium dioxide nanorods were synthesized.•Photo-degradation of methylene blue (MB) was evaluated via Raman spectroscopy.•100% degradation of MB achieved in 50 min under UV light (254 nm, 66 W).
Here, we present a facile synthesis of the boron nitride nanosheets decorated titanium dioxide nanorods (TiO2/BNNS NRs) on glass substrates by hydrothermal method. The photocatalytic performance of TiO2/BNNS NRs is investigated by degrading methylene blue (MB) under UV irradiation (254 nm) and recorded by Raman spectroscopy. The obtained results indicated the photocatalytic performance of TiO2/BNNS NRs was significantly improved than that of TiO2 NRs. The rate of degradation (k) of MB was found to be 0.085 min−1 for TiO2/BNNS NRs and 0.052 min−1 for TiO2 NRs. Besides, TiO2/BNNS NRs hybrid structure exhibits high cycling stability with about 90% after 5 consecutive cycles.
Bedaquiline, a new antituberculosis drug, has already been used in >50 countries. The emergence of bedaquiline resistance is alarming, as it may result in the rapid loss of this new drug. This ...article aims to review currently identified mechanisms of resistance and the emergence of bedaquiline resistance, and discuss strategies to delay the resistance acquisition. In vitro and clinical studies as well as reports from compassionate use have identified the threat of bedaquiline resistance and cross-resistance with clofazimine, emphasizing the crucial need for the systematic surveillance of resistance. Currently known mechanisms of resistance include mutations within the atpE, Rv0678, and pepQ genes. The development of standardized drug susceptibility testing (DST) for bedaquiline is urgently needed. Understanding any target and non-target-based mechanisms is essential to minimize resistance development and treatment failure and help to develop appropriate DST for bedaquiline and genetic-based resistance screening.
Abstract
Gallium Telluride (GaTe), a layered material with monoclinic crystal structure, has recently attracted a lot of attention due to its unique physical properties and potential applications for ...angle-resolved photonics and electronics, where optical anisotropies are important. Despite a few reports on the in-plane anisotropies of GaTe, a comprehensive understanding of them remained unsatisfactory to date. In this work, we investigated thickness-dependent in-plane anisotropies of the 13 Raman-active modes and one Raman-inactive mode of GaTe by using angle-resolved polarized Raman spectroscopy, under both parallel and perpendicular polarization configurations in the spectral range from 20 to 300 cm
−1
. Raman modes of GaTe revealed distinctly different thickness-dependent anisotropies in parallel polarization configuration while nearly unchanged for the perpendicular configuration. Especially, three A
g
modes at 40.2 (
$${\text{A}}_{\text{g}}^{1}$$
A
g
1
), 152.5 (
$${\text{A}}_{\text{g}}^{7}$$
A
g
7
), and 283.8 (
$${\text{A}}_{\text{g}}^{12}$$
A
g
12
) cm
−1
exhibited an evident variation in anisotropic behavior as decreasing thickness down to 9 nm. The observed anisotropies were thoroughly explained by adopting the calculated interference effect and the semiclassical complex Raman tensor analysis.
In this article, the influence of the medium refractive index on optical properties of gold nanorods (GNRs) and their surface enhanced Raman spectroscopy application were studied. In particular, GNRs ...have been applied in biomedical sensors to detect diseases by monitoring the changes in the environment. In this study, the changes in optical properties of GNRs were investigated according to the medium refractive index changes in the cationic surfactant cetyltrimethylammonium bromide (CTAB) during synthesis processes as well as GNR dispersion in different medium refractive indices. For instance, in the solutions with different concentrations of CTAB, GNRs were coated by biomolecules such as PEG, bovine serum albumin (BSA), and glutathione (GSH), which have different refractive indices. The fundamental reason for the change in optical properties of GNRs is also elucidated. GNRs have been used to enhance surface Raman scattering to detect indigo molecules. The results showed that due to the surface plasmon resonance effect, the GNRs could strongly enhance the scattering signal of indigo dyes, with the lowest detectable concentration of up to 10−8 M and with an enhancement coefficient of over 2000 times.
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•Defective UiO-66 was rapidly fabricated by continuous-flow microwave synthesis.•The surface area and pore width of UiO-66 (Zr) were improved by defects.•The most defective ...25Cu(I)@UiO-66 had the highest CO uptake capacity of 2.44 mmol/g.•Defective Cu(I)@UiO exhibited improved CO selectivity.•Cu(I)@UiO-66(Zr) showed good renewability and oxygen-resistant ability.
Developing a highly effective material for CO storage and separation is a challenge. In this study, we first used microwave-assisted continuous-flow synthesis to create defective UiO-66(Zr) frameworks with improved surface area and pore structures, which is highly efficient for large-scale production. The defect concentration of UiO-66(Zr) was rapidly and effectively controlled within a short reaction time of 10 min. Different amounts of Cu2+ were loaded onto defective UiO-66 samples, followed by reducing Cu2+ to Cu+ to obtain Cu(I)@UiO-66 adsorbents (Cu(I)@UiO). X-ray diffraction (XRD), N2-adsorption, FT-IR, SEM, TEM, thermogravimetric analysis (TGA), and XPS analyses were used to characterize the physicochemical properties of the prepared adsorbent materials. Gas adsorption experiments revealed that Cu(I)-decorated defective UiO-66 exhibited high CO adsorption capacity due to the π complexation between Cu+ and CO. The CO adsorbing amount and CO selectivity onto the Cu(I)@UiO-66 samples were improved by adjusting the defect concentration and Cu(I) load on the UiO-66 host. The breakthrough experiment confirms that this defective Cu(I)@UiO adsorbent can efficiently separate CO/N2 mixture under dynamic mixture flow conditions. Furthermore, after several cyclic adsorption–desorption experiments, the defective Cu(I)@UiO-66 is highly regenerable and has a good oxygen-resistant ability. The study describes a simple and scalable method for producing π-complexation adsorbent for CO adsorption.
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