NH Groups Research Articles

What is behind a gas stream scrubbing liquid? Monoethanolamine/water mixtures as seen by dielectric relaxation spectroscopy.

High-quality dielectric data for monoethanolamine (MEA)/water mixtures covering the entire miscibility range are presented. For MEA concentrations c1 ≥ 1 M the obtained complex permittivity spectra, covering the frequency range from 0.05 to 89 GHz, are best described by a sum of four Debye relaxations. Modes at ∼3 GHz and ∼10 GHz are solute-specific. Whilst the first can be assigned to MEA aggregates, the second is a composite arising from "free" MEA dipoles with dynamically retarded water hydrating them. The relaxations at ∼18 GHz and ∼200 GHz essentially reflect the cooperative H-bond fluctuations of more-or-less unperturbed "bulk" water, albeit with minor solute contributions. Evaluation of the bulk-water amplitude reveals that in water-rich mixtures (c1 ≤ 3.5 M) Zt = 3.5 ± 0.2 H2O molecules hydrate a MEA molecule. Then Zt drops linearly, reaching zero for neat MEA. Supported by the literature, this concentration dependence suggests that only H2O molecules H-bonded to the NH2 and OH groups of MEA contribute to Zt. At concentrations beyond hydration shell overlap (c1 ≥ 3.5 M) these H-bonds are gradually eliminated, while new interactions with neighboring MEA molecules are formed. From the evaluation of the MEA-specific amplitudes we conclude that for c1 ≥ 2 M, including neat MEA, ∼35% of the solute molecules are in aggregates, where breaking the intermolecular NH⋯O hydrogen bond determines the dynamics.

A novel electrochemical sensing method based on an amino-functionalized MXene for the rapid and selective detection of Hg2.

Mercury is a highly toxic element that is widely present in all types of environmental media and can accumulate in living organisms. Prolonged exposure to high levels of mercury can lead to brain damage and death, so the detection of mercury is of great importance. In this study, a cost-effective and easy-to-operate electrochemical sensing method was successfully developed based on an amino-functionalized titanium-based MXene (NH2-Ti3C2Tx) for the rapid and selective detection of Hg2+ that could have a coordination effect with the -NH2 group of NH2-Ti3C2Tx to promote the efficient accumulation of Hg2+. In this strategy, the NH2-Ti3C2Tx was first modified on glassy carbon electrodes (GCE) to fabricate the electrochemical sensor. Benefiting from the excellent electrical conductivity, abundant active sites, and strong adsorption capacity performance of the NH2-Ti3C2Tx, the NH2-Ti3C2Tx modified GCE (NH2-Ti3C2Tx/GCE) exhibited satisfactory selectivity and enhanced square wave anodic stripping voltammetry (SWASV) measurement for the rapid detection of trace amounts of Hg2+ in aqueous solutions. The electrochemical sensor was found to be capable of detecting Hg2+ with a low detection limit of 8.27 nmol L-1 and a linear range of 0.5 μmol L-1 to 50 μmol L-1. The response time of the electrochemical sensing method was 308 s. In addition, the electrochemical sensing method has good selectivity, repeatability and stability, and multiple heavy metal ions have no effect on its detection, with repeatability and stability RSDs of 1.68% and 1.43%, respectively. Furthermore, the analysis of practical water samples demonstrated that the developed method was highly practical for the actual determination of Hg2+ with recoveries in the range of 99.22-101.90%.

Negative cooperativity in the formation of H-bond networks involving primary anilines.

Networks of H-bonds can show non-additive behaviour, where the strength of one interaction perturbs another. The magnitude of such cooperative effects can be quantified by measuring the effect of the presence of an intramolecular H-bond at one site on a molecule on the association constant for formation of an intermolecular H-bond at another site. This approach has been used to quantify the cooperativity associated with the interaction of a primary amine with two H-bond acceptors. A series of compounds that have an intramolecular H-bond between an aniline NH2 group and a pyridine nitrogen were prepared, using polarising substituents on the pyridine ring to vary the strength of the intramolecular H-bond. The presence of the intramolecular interaction was confirmed by X-ray crystallography in the solid state and NMR spectroscopy in n-octane solution. UV-vis absorption titrations were used to measure the association constants for formation of an intermolecular H-bond with tri-n-butyl phosphine oxide in n-octane. Electron-donating substituents on the pyridine ring, which increase the strength of the intramolecular H-bond, were found to decrease the strength of the intermolecular H-bond between the aniline and the phosphine oxide. The results were used to determine the H-bond donor parameters for the anilines, α, and there is a linear relationship between the values of α and the H-bond acceptor parameter of the pyridine group involved in the intramolecular H-bond, β. The slope of this relationship was used to determine the cooperativity parameter (κ = -0.10), which quantifies the negative allosteric cooperativity between the two H-bonding interactions. Calculated molecular electrostatic potential surfaces of the anilines quantitatively reproduce the experimental result, which suggests that effects are electrostatic in origin, either due to polarisation of the NH bonds or due to secondary electrostatic interactions between the two H-bond acceptors.

T-BuOLi promoted regioselective N-thiolation of indoles with N-arylthio phthalimide.

The selective N-thiolation of indole substrates poses a challenge due to their diminished nucleophilicity at nitrogen. Herein, we present a novel method for the thiolation of the NH group in indole derivatives by using N-arylthio phthalimide as the sulfur source, t-BuOLi as the base and MeCN as the solvent. The process was successfully conducted under transition metal catalyst-free and room temperature conditions with a high product yield and a short reaction time. The developed protocol exhibited excellent regioselectivity and broad substrate tolerance in the preparation of N-thioindoles with diverse functional groups.

A confinement-regulated (H3C-NH3)+ ion as a smallest dual-wheel rotator showing bisected rotation dynamics.

On the basis of variable-temperature single-crystal X-ray diffraction, rotational energy barrier analysis, variable-temperature/frequency dielectric response, and molecular dynamics simulations, here we report a new crystalline supramolecular rotor (CH3NH3)(18-crown-6)[CuCl3], in which the (H3C-NH3)+ ion functions as a smallest dual-wheel rotator showing bisected rotation dynamics, while the host 18-crown-6 macrocycle behaves as a stator that is not strictly stationary. This study also provides a helpful insight into the dynamics of ubiquitous -CH3/-NH3 groups confined in organic or organic-inorganic hybrid solids.

Adsorption and Kinetic Studies of Nickel(II) Ions onto Vermiculite based Ionite

Using vermiculite based ionite, the absorption efficiencies of Ni2+ ions from synthetic solutions were investigated. The effects of pH and initial concentration of Ni2+ ions their absorption capacity were investigated to optimize process conditions using pseudo-first and pseudo-second-order. The results obtained from the sorption of Ni2+ ions on vermiculite based ionite show the kinetic characteristics close to the pseudo-second order. The high Ni2+ ions sorption is attributed due to the the complexation of metal ions with −NH2 groups present in the absorbent, which results in the strong coordination bonds.

Bio-based iron oxide nanoparticles forming bi-functional chitosan composite adsorbent for Cr(VI) decontamination

Iron oxide nanoparticles (IONPs) synthesized in a bio-based route are viable contenders for the removal of Cr(VI) from contaminated water. However, recovery and reuse of these IONPs are challenging and could limit their practical applicability. Herein, reusable and bi-functional composite chitosan (CS) beads (CS/IONPs) are developed by infusing IONPs in the CS matrix and applied for Cr(VI) adsorption and detoxification from synthetic wastewater. CS/IONPs beads were characterized through various analytical techniques: X-ray diffraction, X-ray photoelectron spectroscopy and Scanning electron microscopy. The loading of IONPs varied from 0.1 to 0.25 (% w/v) with Fe(III)/Fe(II) in a molar ratio of 2. Mesoporous (11.65 nm) CS/IONPs beads with a size from 6.6 − 4.31 mm were formed with a specific surface area of 63.67 m2/g compared to 25.42 m2/g for CS beads. Cr(VI) removal of 98.71 % was achieved by CS/IONPs adsorbent within 480 min at the optimal conditions of initial pH 3, CS/IONPs dosage 2.5 g/L, temperature 25 °C, and initial Cr(VI) concentration 150 mg/L. The co-existing cations didn’t affect Cr(VI) adsorption capacity of CS/IONPs beads, though PO43− and SO42− competed slightly with Cr(VI) adsorption. Cr(VI) removal process was spontaneous and exothermic and followed the pseudo-first-order kinetic. CS/IONPs composite beads could adsorb a maximum of 345.53 mg Cr(VI) per g of IONPs as determined by Langmuir isotherm. The used CS/IONPs beads could be regenerated using NaOH for the initial 4 cycles, but about 15.7 % of active sites were reduced afterwards. Cr(VI) removal involves electrostatic interaction, Cr(VI) reduction to Cr(III), Cr(III) adsorption, Cr(III) surface complexation through abundant –NH2 group, and Cr(III) co-precipitation with Fe(III).

Study on the mechanism of natural polysaccharides on the deastringent effect of Triphala extract

This present study investigated the masking effect of high methoxyl pectin, xanthan gum, and gum Arabic on the astringency of the traditional herbal formula Triphala and further examined the mechanism of polysaccharide reducing astringency. Results of sensory evaluation and electronic tongue illustrated that 0.6 % pectin, 0.3 % xanthan gum, and 2 % gum Arabic had a substantial deastringent effect. The polyphenols in Triphala are basically hydrolysable tannins, which with high degree of gallic acylation may be the main astringent component of Triphala. Moreover, the three polysaccharides can combine with β-casein through CO and NH groups to form soluble binary complexes and decrease the secondary structure of β-casein. When polysaccharides were added to the Triphala-protein system, polyphenol-protein precipitation was also diminished, and they were capable of forming soluble ternary complexes. Consequently, the competition between polysaccharides and polyphenols for binding salivary proteins and the formation of ternary complexes help decrease the astringency of Triphala.

Defective Auδ−-Ov interfacial sites boost C-H bond activation for enhanced selective oxidation of amino alcohols to amino acids

Designing efficient active sites to facilitate the oxidation of hydroxyl group to carboxylic acid under the influence of nitrogen-containing functional groups is worth exploring, but it is rarely investigated. Herein, we construct defective Au-ZrO2 interfacial structures by tuning the calcination temperature of ZrO2 support to boost the oxidation of amino alcohols to amino acids. Interestingly, the modification of calcination temperature induces the escape of saturated coordination oxygen atoms in ZrO2 support, leaving behind abundant surface oxygen vacancy (Ov). The as-formed Auδ−-Ov interfacial site displays the unique synergistic adsorption effect and electron transfer ability. Specifically, the Ov site voluntarily adsorbs the –NH2 group of amino alcohol, thus ensuring that the electron-rich Auδ− nearby Ov site adsorbs the hydroxyl groups and activates the C-H bond activation of NH2CH2CH2O* intermediates. Consequently, Au/ZrO2-600 catalyst with more defective Auδ−-Ov interfacial sites exhibits 98.8 % product yield for the oxidation of diethanolamine to iminodiacetic acid at only 30 °C. The catalyst system is further extended to the oxidation of other amino alcohols, involving monoethanolamine and triethanolamine, to their corresponding amino acids with excellent catalytic performance.

Amino acid modified melamine foam as solid-state proton donor for CsPbBr3-based S-scheme heterojunction driven photocatalytic CO2 reduction

H2O as a proton source affects the stability of lead halide perovskites, restricting the photocatalytic CO2 reduction reaction (CO2RR). In this paper, l-lysine modified melamine foam (L-MF) is designed as an efficient solid-state proton donor to participate in CO2RR of CsPbBr3-based S-scheme heterojunction. On the one hand, abundant –COOH and –NH2 groups of l-lysine would break easily compared with H2O, which provides adequate protons for CO2RR. Moreover, the functionalized –COOH and –NH2 groups of l-lysine as Lewis base could coordinate with unsaturated Pb2+ of CsPbBr3, which could decrease the defect density of perovskite and improve the charge migration of catalyst. On the other hand, three-dimensional and porous melamine foam as a supporter could achieve gas-solid bi-phase CO2RR system, which contributes to mass transfer efficiency between CO2 gas and catalyst, accelerating CO2 conversion into high value-added fuels. Under sunlight irradiation, product yield of CO2RR reaches 73.47 μmol/g/h for L-MF/CsPbBr3/Bi2WO6, which is 2.8- and 72.7-fold of MF/CsPbBr3/Bi2WO6 (25.93 μmol/g/h) and CsPbBr3/Bi2WO6 powder (1.01 μmol/g/h) with H2O as proton source, suggesting the efficient proton supply for CO2RR from solid-state proton donor. This work could open a new avenue to utilize lead halide perovskites-based catalysts for energy conversion.

MOLECULAR INSIGHTS INTO PROPOXAZEPAM INTERACTION WITH TRPV1 RECEPTORS: A DOCKING ANALYSIS

Problem. Pain therapy has remained conceptually stagnant since the opioid crisis, which highlighted the dangers of treating pain with opioids. TRPV1 receptors and their ligands have emerged as promising targets for the management of various pain conditions, including inflammatory and neuropathic pain. Further investigation into the activation and desensitization mechanisms of TRPV1 receptors, as well as the exploration of novel ligands with enhanced selectivity and efficacy, holds the potential to alleviate the burden of chronic pain. Aim. The study of interactions of ligands with the TRPV1 receptor by molecular docking and analysis of components of these interactions. Methods. In order to study the binding energy of the TRPV1 receptor with the researched compounds 8GFA – Cryo-EM structure of human TRPV1 in complex with the analgesic drug SB-366791 was utilized. The docking and QSAR prediction were carried out with propoxazepam, its possible metabolite 3-hydroxopropoxazepam, diazepam, oxazepam, SB-366791, RTX, capsazepin, capsaicin. The docking and QSAR build model using the Maestro Schrödinger Suite. The main results. Propoxazepam has the necessary pharmacophoric features to bind with TRPV1 recepor: region A-benzene ring; region B – the amide group (NH-C=O); region C – alkoxy group. The docking score of propoxazepam (-7.30 kcal/mol) indicates a stronger interaction with the TRPV1 receptor compared to oxazepam (-6.82 kcal/mol), 3-hydroxopropoxazepam (-6.49 kcal/mol), and capsazepin (-6.39 kcal/mol). When considering the increase in the free energy of interactions, the ligands can be ranked as follows: SB-366791 > Capsaicin > RTX > Capsazepin > Propoxazepam > Diazepam > 3-hydroxopropoxazepam > Oxazepam. Propoxazepam establishes two hydrogen bonds: one involving the NH group of the amide (resulting in a hydrogen bond interaction with the linker-neck) and THR550 of the protein, and another between oxygen of the alkoxy group (hydrophobic tail) and TYR511 of the TRPV1 receptor. Ligands with confirmed effects on the TRPV1 receptor also engage in interactions with the protein by forming hydrogen bonds with the same amino acids as the benzodiazepines, namely THR550 and TYR511. Propoxazepam is predicted to have relatively low potency or affinity for TRPV1 (predicted pIC50 value of –1.115), but this value is higher than other ligands. Conclusions. As propoxazepam has the necessary pharmacophoric features of the pharmacophore model of TRPV1 ligands, it could theoretically bind with this receptor. Propoxazepam creates hydrogen bond with TYR511 of the TRPV1 receptor as referent ligand SB-366791. Propoxazepam exhibits one of the largest contributions of hydrogen bonds in the energy of interaction with the receptor. According to QSAR modelling, all studied compounds (3-hydroxopropoxazepam, diazepam, oxazepam, propoxazepam) have low pIC50 values, which could indicate a relatively low potency or affinity for TRPV1. But propoxazepam has the highest predicted pIC50, it means that the model predicts it to be the most potent among the compounds.

Influence of starch silylation on the structures and properties of starch/epoxidized soybean oil-based bioplastics

The present work systematically investigated the influence of starch silylation on the structures and properties of starch/epoxidized soybean oil-based bioplastics. Silylated starch was synthesized using starch particles (SP-ST) or gelatinized starch (SG-ST) under different silane hydrolysis pHs. Due to the appearance of -NH2 groups and lower OH wavenumbers, SP-ST obtained at pH 5 showed higher silylation degree and stronger hydrogen bond interaction with epoxidized soybean oils (ESO) than that at pH 11. The morphology analysis revealed better interfacial compatibility of ESO and SP-ST. The tensile strength of the samples containing SP-ST increased by 51.91 % than the control, emphasizing the enhanced interaction within the bioplastics. However, tensile strength of the bioplastics with SG-ST decreased by 59.56 % due to their high moisture contents from unreacted silanes. Additionally, the bioplastics with SG-ST exhibited an obvious reduction of thermal stability and an increase in water solubility because of the presence of unreacted APMS. The bioplastic degradation was not prevented by starch silylation except high pH. The bioplastics showed the most desirable tensile properties, thermal stability, and water solubility when starch was surface-modified with silanes hydrolyzed at pH 5. These outcomes made the fabricated bioplastics strong candidates for petroleum-based plastics for packaging applications.

Cellulose-based ultrastrong wood adhesive and composites constructed through “sandwich” profile bonding interface

The present paper investigates the bonding interface between cellulose-based adhesive and chemically activated wood to explore the contribution of cohesion and interaction force between adhesive and substrate to the bonding properties. The activated wood surface rich in –NH2 groups is produced by brushing 3-amino-propyl triethoxysilane (APTES) on the natural wood. The amine-functionalized cellulose is made by grafting microcrystalline cellulose with APTES and the adhesive is developed by crosslinking the branched epoxide with the aminated cellulose. Subsequently, a super strong wood laminates is developed by reacting the –NH2 groups on the activated wood surface reacted with the epoxy groups in the adhesive to construct an “amino-epoxy-amino” sandwich bonding interface. The bonding strength of laminates at dry condition and after hot and boiling water treatment is 4.04 MPa, 2.42 MPa and 1.64 MPa, respectively. The strength after boiling water treatment of the plywood laminates made of all-component adhesive enhanced from 0 MPa to 1.64 MPa contrasted with that made of pure aminated cellulose and that prepared from the activated wood surface enhanced from 0.77 MPa to 1.64 MPa contrasted with that made by the nonactivated wood surface. The cohesion of the adhesive and the interaction force between the adhesive and the wood substrate played an important role in the bonding properties.

Multiple hydrogen bonds enable high strength and anti-swelling cellulose-based ionic conductive hydrogels for flexible sensors

Although ionic conductive hydrogels (ICHs) have been widely utilized to fabricate excellent flexible sensors, traditional ICHs are generally easy to swell, resulting in the inevitable failure of flexible sensors. Herein, a facile and effective strategy is employed to impart ICHs with excellent mechanical properties, satisfying anti-swelling property, favorable anti-freezing property, and high ion-conductivity simultaneously, that is to construct multiple hydrogen bonds (H-bonds) through directly dissolving cellulose in salt solutions, avoiding the tedious preparation process of traditional ICHs as well. Notably, the cellulose is directly dissolved in the solution containing zinc ions (Zn2+) and aluminum ions (Al3+), and then acrylic acid (AA) and acrylamide (AAm) are copolymerized in it. Multiple H-bonds are formed among the abundant − OH groups, −NH2 groups, and − COOH groups belonging to cellulose, AAm, and AA, respectively. As a result, the improved anti-swelling ability (88.03 %) and compressive performance (24.11 MPa) of the resultant Ion-C-P(AA-co-AAm) hydrogel are achieved. Besides, excellent conductivity (48.39 mS/cm) and frost resistance are provided by generous Zn2+ and Al3+. Moreover, Ion-C-P(AA-co-AAm) hydrogel exhibits favorable sensitivity in monitoring human activities and can output stable electrical signals in a low-temperature environment, showing a great potential application for flexible sensors.

Development of a capillary electrophoresis method based on magnetic solid-phase extraction for simultaneous and sensitive detection of eight biogenic amines in foods.

Biogenic amines (BAs) in high concentrations are toxic and may cause a series of health symptoms. A sensitive measurement of BA levels is essential for human health. Capillary electrophoresis (CE) has emerged for the separation of eight BAs due to simple sample preparation and highly efficient separation. However, an important drawback for CE is low sensitivity. Magnetic solid-phase extraction (MSPE) has become a technique of interest owing to its brief operation and low solvent consumption. Hence, MSPE as a pretreatment has great potential to improve CE sensitivity for the analysis of BAs in complex food. Results showed that the Pt-Co-MWCNTs-COOH possessed strong magnetism, good reusability, and high adsorptive ability toward eight biogenic amines based on the hydrogen bonding between the -COOH of Pt-Co-MWCNTs-COOH and -NH2 groups of BAs. Using it as an adsorbent, a magnetic solid-phase extraction coupled with capillary electrophoresis (MSPE-CE) method was developed to effectively extract and sensitively analyze eight BAs. Under optimal conditions, the MSPE-CE method has wide linearities (10.0-1000.0 μg L-1 ) and low limits of detection (1.0-6.1 μg L-1 ). The accuracy of the developed method yielded recovery values from 82.07% to 102.58%. Meanwhile, the BAs contents in two samples were analyzed using the MSPE-CE method, with the results consistent with those detected by a high-performance liquid chromatography method. Given those advantages, the established MSPE-CE method promises the practical guidance of monitoring a variety of BAs and provides a foundation for the detection of other food hazards. © 2023 Society of Chemical Industry.

Immobilization of Candida rugosa lipase on optimized polyamidoamine dendrimer functionalized magnetic multiwalled carbon nanotubes for green manufacture of butyl butyrate ester

Mineral acid catalysis in Fisher-Speier esterification is hazardous and have other disadvantages. The objective of the study was immobilization of Candida rugosa lipase onto iron oxide (Fe3O4) impregnated magnetic mutiwalled carbon naotubes (MMWCNTs) using amine functionalized polyamidoamine (PAMAM) dendrimers for manufacture of butyl butyrate ester. Dendrimers were synthesized from reaction of ethyl methacrylate with varying chain length of diamines 1, 4 diaminobutane (DAB) / 1, 3 diaminopropane (DAP) / ethylene diamine (ED). The effect of aliphatic alkyl chain length (CH2) of functionalizing agents ED, DAP and DAB, and dendrimer generations on amount of terminal NH2 group, surface charge, protein loading and immobilized enzyme activities were analysed. Magnetic MWCNTs support surface modified with third generation PAMAM using ethylene diamine showed highest protein load 220.1 mg g−1 and enzymatic activity 8,276.21 U g−1 support. The immobilized enzyme particles were characterized by HRTEM, FTIR, XRD, TGA, VSM and Zeta potential analysis. The immobilized enzyme showed improvement in the dispersion, activity, stability and reusability characteristics. Maximum esterification yield 92.67 % and reuse upto 11 cycles with 65.2 % yield obtained. The immobilized preparation showed 2.3 folds esterification than free enzyme. Developed nanobiocatalyst expects to possess potential for various other applications of lipase catalysed reactions.

Detection of Pb(II) in water via a NH2-MIL-53(Fe)@ITO electrochemical sensor

The evaluation of the concentration of Pb(II) in solution has great significance in avoiding harm to ecology health. In this work, NH2-MIL-53(Fe) modified ITO glass (NH2-MIL-53(Fe)@ITO) was utilized as an electrochemical sensor for the detection of Pb(II) in solutions. FTIR and XPS investigation disclosed that the plentiful surface –NH group on the NH2-MIL-53(Fe) should be responsible for the highly efficient and selective detection abilities of Pb(II) due to the capture and conductivity abilities. The NH2-MIL-53(Fe) was prepared by a solvothermal technique and electrophoresed on the surface of ITO glass. A square wave voltammetry (SWV) method is employed for the sensitive determination of Pb(II). The factors of the detection condition such as the pH and ion interference are also studied. The sensitivity of 16.072 μA μM−1 cm−2 in the linear range of 2–4 μM and 54.143 μA μM−1 cm−2 in the linear range of 5–17 μM, and the limit of detection (LOD) of 0.1 μM are acquired. The repeatability and reproducibility are also studied. EIS and Tafel curves are utilized to investigate the effect of temperatures on the properties of the NH2-MIL-53. This work presents a facile strategy for the preparation of NH2-MIL-53(Fe)@ITO electrochemical sensor via electrolysis, which enhances the sensitivity toward Pb(II) and shows great application potential.

Advancing fluoride (F–) detection: Exploring the potential of digital color analysis with a novel thiourea receptor

This study aimed to explore a novel colorimetric detection method for fluoride using spectroscopic and digital analysis techniques. Thiourea compound synthesized from p-phenylenediamine and 4-nitrophenyl isothiocyanate was used as a receptor, with the NH group playing the role of a binding site to enhance the colorimetric detection process. This method facilitated visual detection by the naked eye and offered selectivity for fluoride ions. The result showed that there was a significant color change response, shifting from colorless to orange when fluoride was detected using the thiourea receptor. In this context, the color change was characterized by a bathochromic shift observed with UV–Vis spectrophotometry and quantified through high Euclidean Distance (ΔE) value of RGB color characteristics in digital analysis. Furthermore, the thiourea-based fluoride detection method had a low detection limit of 1.4 µM for spectroscopic analysis and 1.7 µM for digital analysis, along with a high recovery rate. These results affirmed the significance of spectroscopic and digital analyses using the thiourea receptor as a promising alternative for the rapid on-site detection of fluoride in real environmental samples.

Highly Hydrophilic and Defective Carbon Nitride for Enhanced Photocatalytic Hydrogen Evolution.

Graphitic carbon nitride (g-C3N4), as a kind of nonmetallic low-cost photocatalyst, has great potential in photocatalytic hydrogen (H2) evolution, but its poor hydrophilicity and nonwetting extremely limit its H2 evolution efficiency. Herein, highly hydrophilic and defective g-C3N4 photocatalysts (NH3-CN-P as a representative example) have been fabricated on the basis of the strategy of joint phosphorus doping and ammonia stripping. The dopant of phosphorus prefers to occupy the C atoms bonded to -NH2 groups in the g-C3N4 skeleton, which is conducive to the formation of N defects caused by the effects of electronegativity and charge balance. Moreover, ammonia stripping plays a dual role in exposing plentiful two-dimensional defective planar structure and implanting the hydrophilic groups on the surface. As expected, the photocatalytic H2 evolution property of NH3-CN-P reaches 11.31 mmol g-1 h-1, with an apparent quantum yield of 17.9% at 420 nm, outperforming the majority of the reported g-C3N4-based photocatalysts.

Clinic-o-etiological profile of cholestasis in infants in a tertiary care center

Common presenting feature of hepatobiliary and metabolic dysfunction in neonates is cholestatic jaundice. It is essential to recognise the neonatal cholestasis early. Significant proportion of cases of cholestatic disease are constituted by EHBA. If management of Extra Hepatic Biliary Atresia is delayed beyond three months of life, only option available then is liver transplantation.To analyse etiological factors and to study clinical presentation of cases presenting with cholestasis.Study the clinical presentation and analyse the etiological factors in infants with cholestasis. To determine the validity of ACS and compare outcomes of EHBA with respect to age at presentation.Prospective observational study was done in 104 infants with cholestasis who were admitted in Paediatric ward of niloufer hospital from January 2019 to July 2020.Statistical analysis done by chi square test and fisher’s exact tests.Of the total 104 cases, 47 cases were diagnosed to be EHBA and 38 cases were found to have neonatal hepatitis.58.6% were male and 41.34%were female and 72 were term and 32 were preterm. Mean age of presentation with EHBA and Neonatal hepatitis was 91 days and 94 days. LFT’s in EHBA cases showed mean TSB 12.19 ± 5 mg/dl Vs 11.7 ± 5.8 mg/dl in NH babies with a p value equal to 0.379. Direct bilirubin revealed 6.44 ± 3.1mg/dl Vs 6.64 ± 3.1mg/dl in NH group (p = 0.824).HIDA scan showed 41% had EHBA, 33.3% had NH AIIMS Clinical score (ACS) cannot correctly differentiate EHBA from NH.Survival was significantly higher in infants with EHBA who were operated before 60 days of life.