Sustainable degradation of carbon tetrafluoride to non-corrosive useful products by incorporating reduced electron mediator within electro-scrubbing

The degradation of CF4 gas using existing technologies produces other types of greenhouse gas (CO2) and corrosive side products. The main aim of this study is to degrade CF4 gas at room temperature into useful products without producing corrosive side products by mediated electrochemical reduction (MER) process using an electrogenerated Cu1+[Ni2+(CN)4]1− mediator. Initial studies on the electrolytic reduction of the hetero-bimetallic complex in catholyte solution at anodized Ti cathode was monitored by oxidation/reduction potential (ORP) variation whether the Cu2+ or Ni2+ was reduced in the Cu2+[Ni2+(CN)4] and confirmed by electron spin resonance (ESR) spectroscopy the Cu1+[Ni2+(CN)4]1− formation. The concentration variation of Cu1+[Ni2+(CN)4]1− during CF4 injection demonstrated the degradation of CF4 followed the MER by electrogenerated Cu1+[Ni2+(CN)4]1−. Maximum removal efficiency of CF4 using electroscrubbing process was 96% at room temperature. Through the variation in gas phase parameters, the gas phase mass transfer coefficient was calculated that can facilitate scale up the developed process. Fourier transform infrared spectroscopy analysis in both the gas and solution phases showed that CH3CH2OH was the main product that formed during the removal of CF4 by electrogenerated Cu1+[Ni2+(CN)4]1− at electroscrubber along with a small amount of CF3CH3 intermediate. Importantly, this mechanism also avoided formation of the corrosive product HF

Electrochemically generated bimetallic reductive mediator Cu1+ [Ni2+ (CN) 4] 1− for the degradation of CF4 to ethanol by electro-scrubbing

Remediation of electronic gas CF4 using commercially available technologies results in another kind of greenhouse gas and corrosive side products. This investigation aimed to develop CF4 removal at room temperature with formation of useful product by attempting an electrogenerated Cu1+[Ni2+(CN)4]1− mediator. The initial electrolysis of the bimetallic complex at the anodized Ti cathode demonstrated Cu1+[Ni2+(CN)4]1− formation, which was confirmed by additional electron spin resonance results. The degradation of CF4 followed mediated electrochemical reduction by electrogenerated Cu1+[Ni2+(CN)4]1−. The removal efficiency of CF4 of 95% was achieved by this electroscrubbing process at room temperature. The spectral results of online and offline Fourier transform infrared analyzer, either in gas or in solution phase, demonstrated that the product formed during the removal of CF4 by electrogenerated Cu1+[Ni2+(CN)4]1− by electroscrubbing was ethanol (CH3CH2OH), with a small amount of trifluoroethane (CF3CH3) intermediate

(E)-N′-(3-Bromo-5-chloro-2-hy­droxy­benzyl­idene)nicotinohydrazide

There are two independent mol­ecules in the asymmetric unit of the title compound, C13H9BrClN3O2, in which the dihedral angles between the benzene and pyridine rings are 8.23 (9)° and 52.84 (12)°. Both the mol­ecules exist in an E configuration with respect to the C=N double bond. The two mol­ecules in the asymmetric unit are linked via weak C—H⋯O hydrogen bonds. In both the mol­ecules, an intra­molecular O—H⋯N hydrogen bond generate an S(6) graph-set motif. In the crystal, inter­molecular N—H⋯O and C—H⋯O hydrogen bonds generate bifurcated R 1 2(7) ring motifs. The crystal packing is further stabilized by weak inter­molecular N—H⋯O, N—H⋯N, C—H⋯O and π–π [centroid–centroid distance 3.615 (2) Å] inter­actions

Histological and immunological correlates of suspected leprosy lesions

Thirty-two subjects with suspected leprosy lesions were investigated to assess various modalities of sensibility and sweatfunction and these were correlated with immunological and histological parameters. It was found that pain and temperature, mediated by small unmyelinated fibres were impaired in the early lesions. Impairment of sweat function was seen only when one of the modalities of sensibility was also affected Antibodies specific to a protein (35 kDa) antigen and phenolic glycolipid 1 of Mycobacterium leprae were positive in nine and 12 cases respectively, while 15 of the 31 biopsies revealed the presence of mycobacterial antigens in these lesions. The implications of these findings are discussed

N′-[(E)-2-Hy­droxy-3,5-diiodo­benzyl­idene]pyridine-3-carbohydrazide

In the title compound, C13H9I2N3O2, the dihedral angle between the two aromatic rings is 10.5 (2)°. The mol­ecule displays a trans configuration with respect to the C=N bond. An intra­molecular O—H⋯N hydrogen bond occurs. The crystal packing is stabilized by N—H⋯O and C—H⋯O hydrogen bonds

Sustainable removal of N2O by mediated electrocatalytic reduction at ambient temperature electro-scrubbing using electrogenerated Ni(I) electron mediator

Direct catalysis is generally proposed for nitrous oxide (N2O) abatement but catalysis is expensive, requires high temperatures, and suffers from media fouling, which limits its lifetime. In the present study, an ambient temperature electroscrubbing method was developed, coupling wet-scrubbing with an electrogenerated Ni(I) ([Ni(I)(CN)4]3−) mediator, to enable N2O reduction in a single process stage. The initial studies of 10 ppm N2O absorption into 9 M KOH and an electrolyzed 9 M KOH solution showed no removal. However, 95% N2O removal was identified through the addition of Ni(I) to an electrolyzed 9 M KOH. A change in the oxidation/reduction potential from −850 mV to −650 mV occurred following a decrease in Ni(I) concentration from 4.6 mM to 4.0 mM, which confirmed that N2O removal was mediated by an electrocatalytic reduction (MER) pathway. Online analysis identified the reaction product to be ammonia (NH3). Increasing the feed N2O concentration increased NH3 formation, which suggests that a decrease in electrolyzed solution reactivity induced by the increased N2O load constrained the side reaction with the carrier gas. Importantly, this study outlines a new regenerable method for N2O removal to commodity product NH3 at ambient temperature that fosters process intensification, overcomes the limitations generally observed with catalysis, and permits product transformation to NH3

Mucin binding reduces colistin antimicrobial activity

Colistin has found increasing use in treating drug-resistant bacterial lung infections, but potential interactions with pulmonary biomolecules have not been investigated. We postulated that colistin, like aminoglycoside antibiotics, may bind to secretory mucin in sputum or epithelial mucin that lines airways, reducing free drug levels. To test this hypothesis, we measured binding of colistin and other antibiotics to porcine mucin, a family of densely glycosylated proteins used as a surrogate for human sputum and airway mucin. Antibiotics were incubated in dialysis tubing with or without mucin, and concentrations of unbound antibiotics able to penetrate the dialysis tubing were measured over time using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The percentage of antibiotic measured in the dialysate after 4 h in the presence of mucin, relative to the amount without mucin, was 15% for colistin, 16% for polymyxin B, 19% for tobramycin, 52% for ciprofloxacin, and 78% for daptomycin. Antibiotics with the strongest mucin binding had an overall polybasic positive charge, whereas those with comparatively little binding were less basic. When comparing MICs measured with or without added mucin, colistin and polymyxin B showed >100-fold increases in MICs for multiple Gram-negative bacteria. Preclinical evaluation of mucin binding should become a standard procedure when considering the potential pulmonary use of new or existing antibiotics, particularly those with a polybasic overall charge. In the airways, mucin binding may reduce the antibacterial efficacy of inhaled or intravenously administered colistin, and the presence of sub-MIC effective antibiotic concentrations could result in the development of antibiotic resistance

Amidated and ibuprofen-conjugated kyotorphins promote neuronal rescue and memory recovery in cerebral hypoperfusion dementia model

Copyright © 2016 Sá Santos, Santos, Pinto, Ramu, Heras, Bardaji, Tavares and Castanho. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Chronic brain ischemia is a prominent risk factor for neurological dysfunction and progression for dementias, including Alzheimer's disease (AD). In rats, permanent bilateral common carotid artery occlusion (2VO) causes a progressive neurodegeneration in the hippocampus, learning deficits and memory loss as it occurs in AD. Kyotorphin (KTP) is an endogenous antinociceptive dipeptide whose role as neuromodulator/neuroprotector has been suggested. Recently, we designed two analgesic KTP-derivatives, KTP-amide (KTP-NH2) and KTP-NH2 linked to ibuprofen (IbKTP-NH2) to improve KTP brain targeting. This study investigated the effects of KTP-derivatives on cognitive/behavioral functions (motor/spatial memory/nociception) and hippocampal pathology of female rats in chronic cerebral hypoperfusion (2VO-rat model). 2VO-animals were treated with KTP-NH2 or IbKTP-NH2 for 7 days at weeks 2 and 5 post-surgery. After behavioral testing (week 6), coronal sections of hippocampus were H&E-stained or immunolabeled for the cellular markers GFAP (astrocytes) and NFL (neurons). Our findings show that KTP-derivatives, mainly IbKTP-NH2, enhanced cognitive impairment of 2VO-animals and prevented neuronal damage in hippocampal CA1 subfield, suggesting their potential usefulness for the treatment of dementia.Funding was provided by the Portuguese Agency Fundação para a Ciência e a Tecnologia SFRH/BPD/79542/2011 fellowship)info:eu-repo/semantics/publishedVersio

Antifungal and anti-biofilm activity of designed derivatives from kyotorphin

© 2019 British Mycological Society. Published by Elsevier Ltd. All rights reserved.Kyotorphin (KTP, l-tyrosyl-l-arginine) is an endogenous analgesic neuropeptide first isolated from bovine brain in 1979. Previous studies have shown that kyotorphins possess anti-inflammatory and antimicrobial activity. Six kyotorphins—KTP-NH2, KTP–NH2–DL, ibuprofen-conjugated KTP (IbKTP), IbKTP-NH2, N-methyl-D-Tyr-L-Arg, and N-methyl-L-Tyr-D-Arg—were designed and synthesized to improve lipophilicity and resistance to enzymatic degradation. This study assessed the antimicrobial and antibiofilm activity of these peptides. The antifungal activity of kyotorphins was determined in representative strains of Candida species, including Candida albicans ATCC 10231, Candida krusei ATCC 6258, and six clinical isolates—Candida dubliniensis 19-S, Candida glabrata 217-S, Candida lusitaniae 14-S, Candida novergensis 51-S, Candida parapsilosis 63, and Candida tropicalis 140-S—obtained from the oral cavity of HIV-positive patients. The peptides were synthesized by standard solution or solid-phase synthesis, purified by RP-HPLC (purity >95 %), and characterized by nuclear magnetic resonance. The results of the broth microdilution assay and scanning electron microscopy showed that IbKTP-NH2 presented significant antifungal activity against Candida strains and antibiofilm activity against the clinical isolates. The absence of toxic activity and survival after infection was assessed after injecting the peptide in larvae of Galleria mellonella as experimental infection model. Furthermore, IbKTP-NH2 had strong antimicrobial activity against multidrug-resistant bacteria and fungi and was not toxic to G. mellonella larvae up to a concentration of 500 mM. These results suggest that IbKTP-NH2, in addition to its known effect on cell membranes, can elicit a cellular immune response and, therefore, is promising for biomedical application.This research was supported by FAPESP (Grant No. 2017/00032-0). This article is also part of the Fungal Adaptation to Hostile Challenges special issue for the third International Symposium on Fungal Stress (ISFUS), which is supported by the Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) (Grant No. 2018/20571-6) and the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) (Grant No. 88881.289327/2018-01).info:eu-repo/semantics/publishedVersio