9 months of delamanid, linezolid, levofloxacin, and pyrazinamide versus conventional therapy for treatment of fluoroquinolone-sensitive multidrug-resistant tuberculosis (MDR-END): a multicentre, randomised, open-label phase 2/3 non-inferiority trial in South Korea.

BACKGROUND: With the introduction of new anti-tuberculosis drugs, all-oral regimens with shorter treatment durations for multidrug-resistant tuberculosis have been anticipated. We aimed to investigate whether a new all-oral regimen was non-inferior to the conventional regimen including second-line anti-tuberculosis drugs for 20-24 months in the treatment of fluoroquinolone-sensitive multidrug-resistant tuberculosis. METHODS: In this multicentre, randomised, open-label phase 2/3 non-inferiority trial, we enrolled men and women aged 19-85 years with multidrug-resistant tuberculosis confirmed by phenotypic or genotypic drug susceptibility tests or rifampicin-resistant tuberculosis by genotypic tests at 12 participating hospitals throughout South Korea. Participants with fluoroquinolone-resistant multidrug-resistant tuberculosis were excluded. Participants were randomly assigned (1:1) to two groups using a block randomisation, stratified by the presence of diabetes and cavitation on baseline chest radiographs. The investigational group received delamanid, linezolid, levofloxacin, and pyrazinamide for 9 months, and the control group received a conventional 20-24-month regimen, according to the 2014 WHO guidelines. The primary outcome was the treatment success rate at 24 months after treatment initiation in the modified intention-to-treat population and the per-protocol population. Participants who were "cured" and "treatment completed" were defined as treatment success following the 2014 WHO guidelines. Non-inferiority was confirmed if the lower limit of a 97·5% one-sided CI of the difference between the groups was greater than -10%. Safety data were collected for 24 months in participants who received a predefined regimen at least once. This study is registered with ClinicalTrials.gov, NCT02619994. FINDINGS: Between March 4, 2016, and Sept 14, 2019, 214 participants were enrolled, 168 (78·5%) of whom were included in the modified intention-to-treat population. At 24 months after treatment initiation, 60 (70·6%) of 85 participants in the control group had treatment success, as did 54 (75·0%) of 72 participants in the shorter-regimen group (between-group difference 4·4% [97·5% one-sided CI -9·5% to ∞]), satisfying the predefined non-inferiority margin. No difference in safety outcomes was identified between the control group and the shorter-regimen group. INTERPRETATION: 9-month treatment with oral delamanid, linezolid, levofloxacin, and pyrazinamide could represent a new treatment option for participants with fluoroquinolone-sensitive multidrug-resistant tuberculosis. FUNDING: Korea Disease Control and Prevention Agency, South Korea.

Melamine sponge-based copper-organic framework (Cu-CPP) as a multi-functional filter for air purifiers.

COVID-19 has drawn great attention on the necessity for establishing pathogen-free indoor air. This paper offers an insight into the potential application of a multi-purpose filter to remove fine particulates and disinfect pathogens using melamine sponge with a copper-organic framework. In-situ growth dip coating method was applied to coat Cu-based coordination polymer particle (Cu-CPP) on melamine sponge (MS). The integration of Cu-CPPs with high crystallinity and highly active surface area (1,318.1 m2/g) enabled Cu-CPP/MS to have an excellent capture rate (99.66%) and an instant disinfection rate of 99.54% for Escherichia coli. Electrostatic attraction seemed to play a crucial role in capturing negative-charged pathogens effectively by positive charges on Cu-CPP arising from unbalanced copper ions in Cu-CPP. Disinfection of pathogens was mainly attributed to catalytically active Cu2+ sites. Organic ligand played an important role in bridging and maintaining Cu2+ ions within the framework. This study highlights the design of a new capture-and-disinfection (CDS) air filter system for pathogens using Cu-CPP/MS. It can be applied as a substitute for conventional high-efficiency particulate air (HEPA) filters. Electronic Supplementary Material: Supplementary material is available for this article at 10.1007/s11814-021-1000-4 and is accessible for authorized users.

Coupled adsorption-photocatalysis process for the removal of diclofenac using magnetite/reduced graphene oxide nanocomposite.

Diclofenac (DCF) is frequently detected in water bodies (ng/L to g/L) as it is not completely removed by conventional wastewater treatment plants. Adsorption and photocatalysis have been studied as promising methods for treating DCF; however, both processes have limitations. Thus, in this study, the removal efficiency of DCF is evaluated using a magnetite/reduced graphene oxide (Fe3O4/RGO) nanocomposite via a coupled adsorption-catalysis process. The Fe3O4/RGO nanocomposite was successfully synthesized using a microwave-assisted solvothermal method and exhibited a bandgap of 2.60 eV. The kinetic data best fitted the Elovich model (R2 = 0.994, χ2 = 0.29), indicating rapid adsorption. The maximum DCF adsorption capacity calculated using the Langmuir model was 80.33 mg/g. An ultraviolet C (UVC) light source and 0.1 g/L of Fe3O4/RGO nanocomposite were the optimum conditions for the removal of DCF (C0 = 30 mM) by a coupled adsorption-photocatalysis process (first-order rate constant (k) = 0.088/min), which was greater than the single adsorption (k = 0.029/min) and pre-adsorption and post-photocatalysis (k = 0.053/min) processes. This indicates that the adsorbed DCF did not hamper the photocatalytic reaction of the Fe3O4/RGO nanocomposite, but rather enhanced the coupled adsorption-photocatalytic reaction. DCF removal efficiency was higher at acidic conditions (pH 4.3-5.0), because high H+ promotes the generation of certain reactive oxygen species (ROS) and increases of electrostatic interaction. The presence of NaCl and CaCl2 (10 mM) did not notably affect the total DCF removal efficiency; however, Ca2+ affected the initial DCF adsorption affinity. Scavenger experiments demonstrated O2∙- and h+ play a key ROS than ·OH to degrade DCF. The acute toxicity of DCF towards Aliivibrio fischeri gradually decreased with increasing treatment time.

Synthesis of recyclable and light-weight graphene oxide/chitosan/genipin sponges for the adsorption of diclofenac, triclosan, and microplastics.

Emerging micropollutants, such as pharmaceuticals and microplastics (MPs), have become a pressing water environmental concern. The aim of this study is to synthesize chitosan sponges using graphene oxide (GO) and genipin (GP) for the removal of pharmaceuticals (diclofenac (DCF) and triclosan (TCS)) and MPs, verify their adsorption mechanisms, evaluate the effects of temperature, pH, and salinity on their adsorption capacities, and determine their reusability. The GO5/CS/GP sponge exhibited a macroporous nature (porosity = 95%, density = 32.6 mg/cm3). GO and cross-linker GP enhanced the adsorption of DCF, TCS, and polystyrene (PS) MPs onto the CS sponges. The adsorption of DCF, TCS, and PS MPs involved multiple steps: surface diffusion and pore diffusion of the sponge. The adsorption isotherms demonstrated that Langmuir model was the most fitted well model to explain adsorption of TCS (qm = 7.08 mg/g) and PS MPs (qm = 7.42 mg/g) on GO5/CS/GP sponge, while Freundlich model suited for DCF adsorption (qm = 48.58 mg/g). DCF adsorption was thermodynamically spontaneous and endothermic; however, the adsorption of TCS and PS MPs was exothermic (283-313 K). The optimal pH was 5.5-7 due to the surface charge of the GO5/CS/GP sponge (pHzpc = 5.76) and ionization of DCF, TCS, and PS MPs. As the salinity increased, DCF removal efficiency drastically decreased due to the weakening of electrostatic interactions; however, TCS removal efficiency remained stable because TCS adsorption was mainly caused by hydrophobic and π-π interactions rather than electrostatic interaction. The removal of PS MPs was enhanced by the electrostatic screening effects of high Na+ ions. PS nanoplastics (average size = 26 nm) were removed by the GO5/CS/GP sponge at a rate of 73.0%, which was better than that of PS MPs (41.5%). In addition, the GO5/CS/GP sponge could be recycled over five adsorption-desorption cycles.

Adsorption behavior of triclosan on microplastics and their combined acute toxicity to D. magna.

Microplastics (MP) have been recently identified as emerging water contaminants in worldwide. Owing to its physicochemical properties, MP have been considered as a vector of other micropollutants and may affect their fate and ecological toxicity in the water environment. In this study, triclosan (TCS), which is a widely-used bactericide, and three frequently found types of MP (PS-MP, PE-MP, and PP-MP) were investigated. The adsorption behavior of TCS on MP was investigated by the effect of reaction time, initial concentration of TCS, and other water chemistry factors. Elovich model and Temkin model are the most fitted well with kinetics and adsorption isotherms, respectively. The maximum TCS adsorption capacities were calculated for PS-MP (9.36 mg/g), PP-MP (8.23 mg/g), and PE-MP (6.47 mg/g). PS-MP had higher affinity to TCS owing to hydrophobic and π-π interaction. The TCS adsorption on PS-MP was inhibited by decreasing concentrations of cations, and increasing concentration of anion, pH, and NOM concentration. At pH 10, only 0.22 mg/g of adsorption capacity was obtained because of the isoelectric point (3.75) of PS-MP and pKa (7.9) of TCS. And almost no TCS adsorption occurred at NOM concentration of 11.8 mg/L. Only PS-MP had no acute toxic effect on D. magna, whereas TCS showed acute toxicity (EC50,24h of TCS = 0.36 ± 0.4 mg/L). Although survival rate increased when TCS with PS-MP due to lower the TCS concentration in solution via adsorption, PS-MP was observed in intestine and body surface of D. magna. Our findings can contribute to understanding the combined potential effects of MP fragment and TCS to aquatic biota.

Adsorption of Hg(II) on polyethyleneimine-functionalized carboxymethylcellulose beads: Characterization, toxicity tests, and adsorption experiments.

Mercury (Hg) is widely used in many industrial processes and is released into the environment. Therefore, efficient removal of Hg from water is of vital importance worldwide. Here, we explored the adsorption characteristics of Hg(II) on polyethyleneimine-functionalized carboxymethylcellulose (PEI-CMC) beads and studied the toxicity of the beads toward Daphnia magna and Pseudokirchneriella subcapitata. The PEI-CMC beads had an average particle size of 2.04 ± 0.25 mm, a point of zero charge (pHpzc) of 5.8, and a swelling ratio of 2.45. Acute toxicity tests demonstrated that the PEI-CMC beads had no toxic effects on D. magna. The growth inhibition tests revealed that growth inhibition of P. subcapitata could be attributed to adsorption of trace elements in growth media on the PEI-CMC beads. The adsorption experiments exhibited that the Matthews and Weber model best described the kinetic data, whereas the Redlich-Peterson model was well fitted to the isotherm data. The theoretical maximum Hg(II) adsorption capacity of the PEI-CMC beads was 313.1 mg/g. The thermodynamic experiments showed endothermic nature of the Hg(II) adsorption on the PEI-CMC beads at 10-40 °C. The adsorption experiments exhibited that the Hg(II) adsorption capacity decreased gradually as pH increased from 2 to 12. The adsorption of Hg(II) on the PEI-CMC beads can occur through chelation and electrostatic attraction. The FTIR and XPS spectra before and after Hg(II) adsorption confirmed that chelation of neutral Hg(II) species (HgCl2, HgClOH, and Hg(OH)2) can occur with amino and oxygen-containing functional groups on the PEI-CMC beads. Considering species distribution of Hg(II) and the pHpzc of the PEI-CMC beads, electrostatic attraction between the positively-charged beads and anionic Hg(II) species (HgCl3- and HgCl42-) can take place in highly acidic solutions. The PEI-CMC beads were regenerated and reused for Hg(II) adsorption using 0.1 M HCl.