Amide Functional Groups Research Articles

Compatibility and antimicrobial activity of silver nanoparticles synthesized using Lycopersicon esculentum peels.

Nanoparticles have gained worldwide attention as a new alternative to chemical control agents due to their special physiochemical properties. The current study focused on the environmentally friendly synthesis of silver nanoparticles (AgNPs) using Lycopersicon esculentum peel. In addition to studying the intrinsic cytotoxic effectiveness of Le-AgNPs contribute to their antibacterial, and antifungal activities and the effect of nanoparticles on the integrity of their morphological behavior. The initiative biosynthesis of L. esculentum silver nanoparticles (Le-AgNPs) was indicated by the color change of L. esculentum (Le) extract mixed with silver nitrate (AgNO3) solution from faint pink to faint brown. UV-visible spectroscopy, Dynamic light scattering (DLS), Fourier-transform infrared spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and X-ray diffraction techniques were used to characterize biosynthesized Le-AgNPs. Results of UV-visible spectroscopy recorded surface plasmon resonance at 310nm for SPR of 2.5. The DLS results showed particles of 186nm with a polydispersity index of 0.573. The FTIR spectrum indicated the existence of carboxyl, hydroxyl, phenolic, and amide functional groups. The HR-TEM analysis revealed quasi-spherical crystal particles of Le-AgNPs. Le-AgNPs had a negative zeta potential of - 68.44mV, indicating high stability. Bacillus subtilis ATCC 6633 and Escherichia coli ATCC 8739 were the most susceptible pathogens to Le-AgNPs inhibition, with inhibition zone diameters (IZDs) of 4.0 and 0.92cm, respectively. However, Listeria monocytogenes NC 013768 and Shigella sonnei DSM 5570 were the most resistant pathogens, with IZDs of 0.92 and 0.90cm, respectively. Le-AgNPs demonstrated good inhibitory potential against pathogenic fungi, with IZDs of 3.0 and 0.92cm against Alternaria solani ATCC 62102 and Candida albicans DSM 1386, respectively. The cytotoxicity effect was observed at a half-maximal inhibitory concentration (IC50) of 200.53μg/ml on human colon NCM460D normal cells.

Hydrothermally synthesized nitrogen-doped hydrochar from sawdust biomass for supercapacitor electrodes

Porous carbon generated from biomass is among the most promising electrode materials for supercapacitor applications. In this research work, sawdust was used as a carbon source to synthesize N-doped hydrochars via the hydrothermal method in the presence of nitrogen-containing compounds including ammonium chloride, urea agar, ammonium molybdate tetrahydrate, and mammalian urine, followed by chemical activation by potassium hydroxide. Using the hydrothermal technique, it was possible to dope 7.06 wt% of nitrogen into the hydrochar. The as synthesized materials were characterized by TGA/DTA, FTIR, BET, XRD, SEM/EDS, XPS, and proximate analysis. Furthermore, EIS, CV, and GCD were used to assess electrochemical performance. All the N-doped hydrochars synthesized samples possess crystalline and mesoporous structures with hydroxyl and amide functional groups. The KOH activation improved the specific surface area and pore volume by 8.5 % and 21 %, respectively. The maximum specific surface area and pore volume were found to be 560.72 m2/g and 0.2246 cc/g, respectively. The CV findings demonstrate the battery-like characteristics of the electrocatalysts made with molybdenum (VI) oxide (MoO3) embedded in these N-doped hydrochars, yielding 35.16 F/g specific capacitance at 10 mV/s. In contrast, the GCD's specific capacitance displays 80 F/g at 0.5 Ag−1.

Data mining of PubChem bioassay records reveals diverse OXPHOS inhibitory chemotypes as potential therapeutic agents against ovarian cancer

Focused screening on target-prioritized compound sets can be an efficient alternative to high throughput screening (HTS). For most biomolecular targets, compound prioritization models depend on prior screening data or a target structure. For phenotypic or multi-protein pathway targets, it may not be clear which public assay records provide relevant data. The question also arises as to whether data collected from disparate assays might be usefully consolidated. Here, we report on the development and application of a data mining pipeline to examine these issues. To illustrate, we focus on identifying inhibitors of oxidative phosphorylation, a druggable metabolic process in epithelial ovarian tumors. The pipeline compiled 8415 available OXPHOS-related bioassays in the PubChem data repository involving 312,093 unique compound records. Application of PubChem assay activity annotations, PAINS (Pan Assay Interference Compounds), and Lipinski-like bioavailability filters yields 1852 putative OXPHOS-active compounds that fall into 464 clusters. These chemotypes are diverse but have relatively high hydrophobicity and molecular weight but lower complexity and drug-likeness. These chemotypes show a high abundance of bicyclic ring systems and oxygen containing functional groups including ketones, allylic oxides (alpha/beta unsaturated carbonyls), hydroxyl groups, and ethers. In contrast, amide and primary amine functional groups have a notably lower than random prevalence. UMAP representation of the chemical space shows strong divergence in the regions occupied by OXPHOS-inactive and -active compounds. Of the six compounds selected for biological testing, 4 showed statistically significant inhibition of electron transport in bioenergetics assays. Two of these four compounds, lacidipine and esbiothrin, increased in intracellular oxygen radicals (a major hallmark of most OXPHOS inhibitors) and decreased the viability of two ovarian cancer cell lines, ID8 and OVCAR5. Finally, data from the pipeline were used to train random forest and support vector classifiers that effectively prioritized OXPHOS inhibitory compounds within a held-out test set (ROCAUC 0.962 and 0.927, respectively) and on another set containing 44 documented OXPHOS inhibitors outside of the training set (ROCAUC 0.900 and 0.823). This prototype pipeline is extensible and could be adapted for focus screening on other phenotypic targets for which sufficient public data are available.Scientific contributionHere, we describe and apply an assay data mining pipeline to compile, process, filter, and mine public bioassay data. We believe the procedure may be more broadly applied to guide compound selection in early-stage hit finding on novel multi-protein mechanistic or phenotypic targets. To demonstrate the utility of our approach, we apply a data mining strategy on a large set of public assay data to find drug-like molecules that inhibit oxidative phosphorylation (OXPHOS) as candidates for ovarian cancer therapies.Graphical

Amide groups in 3.7 billion years old liquid inclusions

Carbon with depleted d13C (down to − 25.6‰ VPDB) found in > 3.7 billion year old metamorphic sediments from the Isua Supracrustal Belt, Southwestern Greenland, has been proposed to represent the oldest remains of life on Earth. Graphitic inclusions within garnet porphyroblasts from this locality have been shown to associate with elements consistent with biogenic remains. In this report, we focus on certain liquid inclusions found in the Isua garnets, characterizing their chemical composition using atomic force microscopy, AFM-based infrared spectroscopy, optical photothermal infrared spectroscopy, Raman spectroscopy, and time-of-flight secondary ion mass spectrometry. Our results show that the liquid inclusions contain functional groups consisting of carbon, nitrogen, and oxygen in a configuration similar to amide functional groups. We suspect that the amide groups formed from N, O and C-containing volatile components that were released from the original kerogenous material enclosed in the garnets, as this was graphitized during thermal maturation. This is consistent with the observed inclusion assemblage of solid graphitic and viscous fluid inclusions alike. Our observations are compatible with the inclusions forming from biogenic precursor material, and when considered alongside previous reports on the carbonaceous material in the Isua metamorphic sediments, these and our study collectively indicate that the carbonaceous material in the Isua metasediments represents the oldest traces of life on Earth.

Preparation of new green poly (amino amide) based on cellulose nanoparticles for adsorption of Congo red and its adaptive neuro-fuzzy modeling

In this study, a novel green poly(amino amide) nanoparticle based on cellulose nanoparticles (Cell-PAMN) was developed for the efficient adsorption of Congo Red dye. Cellulose nanocrystals obtained from acid hydrolysis of cotton linter were functionalized via Oxa-Michael addition of acrylamide on their surface hydroxyl groups, followed by transamidation with ethylenediamine. The resulting nanoparticles were characterized using FT-IR spectroscopy, SEM, and X-ray diffraction techniques. The as-prepared Cell-PAMN exhibited considerably higher adsorption capacity compared to unmodified cellulose nanoparticles due to the presence of amino and amide functional groups. The adsorption kinetics and the effects of parameters such as contact time and initial dye concentration on the adsorption capacity were investigated. An adaptive Neuro-Fuzzy model was used to study the efficiency of dye removal, accurately predicted the adsorption behavior of Cell-PAMN. The kinetic study results showed that the adsorption process followed a pseudo-second-order kinetic model, with a maximum adsorption capacity of around 40 mg/g. The results demonstrated the potential of the synthesized material for the removal of Congo Red from aqueous solutions, highlighting its applicability in wastewater treatment. This research contributes to the development of sustainable and eco-friendly materials for environmental remediation applications.

New biologically active sulfonamides as potential drugs for Alzheimer's disease.

A family of new compounds with sulfonamide and amide functional groups as potential Alzheimer's disease drugs were prepared by multistep synthesis. Thermal stability measurements recorded the initial decomposition in the range of 200-220°C, close above the melting point. The final compounds were tested for their ability to inhibit acetylcholinesterase and butyrylcholinesterase, and the in vitro dissolution behavior of selected compounds was studied through both lipophilic and hydrophilic matrix tablets. All nine tested derivatives were even more active in inhibiting acetylcholinesterase than the clinically used rivastigmine. Regression analysis of the obtained dissolution profiles was performed, and the effects of the pH and the release mechanism were determined. Some substances showed remarkable biological activity and became a subject of interest for further extensive study.

Lipophilic EDTA-based ligands in different diluents for the extraction of rare earths: Preliminary results with Nd(III), Dy(III) and Pr(III) in chloride and nitrate media

A separation method for the recovery of neodymium(III) from two different media, chloride and nitrate, by implementing solvent extraction technique with a novel lipophilic diamide derivative of ethylenediamine tetraacetic acid (EDTA), namely 2,2’-N,N′-didecyl-dioxo-N,N′,N″,N″’-tetraazatetratriacontane-N″,N″’-diyl diacetic acid (H2E4C10), has been investigated. Initial screening results demonstrated acceptable solubility (ca. 15 mM) of the diamide in 1,3-diisopropylbenzene (DiPB) and in a 93:7 v:v n-dodecane:n-octanol mixture (DOm) as non-polar diluents. Further investigations aiming at determining operational parameters associated with the befitted extractant systems were conducted at pH ranging from 2 to 4 in chloride and nitrate media. A pH-dependent performance of the proposed systems revealed loading capacity peaking at pH = 3 with the respective values of 1.7 and 2.0 g L−1 in nitrate and chloride media. The extraction efficiency, the distribution coefficients, and the separation factor (E%,D and SF, respectively) were determined for an equimolar mixture of neodymium and two other potential competitive lanthanides, namely dysprosium and praseodymium. The best selectivity was observed in the chloride medium at pH = 4 yielding SFNd/Pr = 1.48 and SFNd/Dy = 2.03. Neodymium-to-extractant stoichiometry was evidenced in chloroform to be 1:1 H2E:Nd at pH = 2. Thermodynamic constants related to the considered extraction equilibrium have been determined by using the Van't Hoff relation and the slope analysis method. It appeared within the selected pH-range that the mechanism of the Nd3+ transfer was strongly influenced by the nature of the diluent. This was illustrated by the enthalpy-driven transfer when Nd3+ was extracted with the H2E-4C10-Dom system (aliphatic diluent) while the transfer became entropy-driven when the extraction was performed with the H2E-4C10-DiPB system (aromatic diluent). The complexation of Nd3+ involved mainly the participation of both the amide and carboxylic functional groups. The transfer of the cation to the organic phase might occur through the formation of the Nd(HE)A2 complex (where A is either a nitrate or a chloride anion), allowing for the lowest associated standard Gibbs free energy of transfer (−28 < ΔG° < −24 kJ mol−1) regardless of the aqueous feed.

Al(SO4)(OH)·5H2O Stemming from Complexation of Aluminum Sulfate with Water-Soluble Ternary Copolymer and further Stabilized by Silica Gel as Effective Admixtures for Enhanced Mortar Cementing.

A water-soluble ternary copolymer bearing carboxyl, sulfonic, and amide functional groups was synthesized using ammonium persulfate-catalyzed free radical polymerization in water, resulting in high monomer conversion. This copolymer was then complexed with aluminum sulfate, forming an admixture containing Al(SO4)(OH)·5H2O, which was subsequently combined with silica gel. Characterization revealed that the synthesized copolymer formed a large, thin membrane that covered both the aluminum compounds and the silica gel blocks. The introduction of this complex admixture, combining the copolymer and aluminum sulfate, not only reduced the setting times of the cement paste but also enhanced the mechanical strengths of the mortar compared to using aluminum sulfate alone. The complex admixture led to the formation of katoite, metajennite, and C3A (tricalcium aluminate) in the mortar, demonstrating significant linking effects, whereas pure aluminum sulfate could not completely transform C3S within 24 h. Further addition of silica gel to the complex admixture further shortened the setting times of the paste, slightly reduced compressive strength, but improved flexural strength compared to the initial complex admixture. The silicon components appeared to fill the micropores and mesopores of the mortar, accelerating cement setting and enhancing flexural strength, while slightly decreasing compressive strength. This study contributed to the development of new cementing accelerators with improved hardening properties.

Analysis of Structural Changes of pH-Thermo-Responsive Nanoparticles in Polymeric Hydrogels.

The pH- and thermo-responsive behavior of polymeric hydrogels MC-co-MA have been studied in detail using dynamic light scattering DLS, scanning electron microscopy SEM, nuclear magnetic resonance (1H NMR) and rheology to evaluate the conformational changes, swelling-shrinkage, stability, the ability to flow and the diffusion process of nanoparticles at several temperatures. Furthermore, polymeric systems functionalized with acrylic acid MC and acrylamide MA were subjected to a titration process with a calcium chloride CaCl2 solution to analyze its effect on the average particle diameter Dz, polymer structure and the intra- and intermolecular interactions in order to provide a responsive polymer network that can be used as a possible nanocarrier for drug delivery with several benefits. The results confirmed that the structural changes in the sensitive hydrogels are highly dependent on the corresponding critical solution temperature CST of the carboxylic (-COOH) and amide (-CONH2) functional groups and the influence of calcium ions Ca2+ on the formation or breaking of hydrogen bonds, as well as the decrease in electrostatic repulsions generated between the polymer chains contributing to a particle agglomeration phenomenon. The temperature leads to a re-arrangement of the polymer chains, affecting the viscoelastic properties of the hydrogels. In addition, the diffusion coefficients D of nanoparticles were evaluated, showing a closeness among with the morphology, shape, size and temperature, resulting in slower diffusions for larger particles size and, conversely, the diffusion in the medium increasing as the polymer size is reduced. Therefore, the hydrogels exhibited a remarkable response to pH and temperature variations in the environment. During this research, the functionality and behavior of the polymeric nanoparticles were observed under different analysis conditions, which revealed notable structural changes and further demonstrated the nanoparticles promising high potential for drug delivery applications. Hence, these results have sparked significant interest in various scientific, industrial and technological fields.

Gelatin-based carbon quantum dot-molecularly imprinted polymer: Safe photoluminescent core-shell nano-carrier for the pH-responsive anticancer drug delivery

This study aims to synthesize a core-shell gelatin-based carbon quantum dot-molecularly imprinted polymer (MIP@g-CQD) via the precipitation free-radical polymerization process using methotrexate (MTX) as a model anticancer template. To investigate the efficiency of the prepared photoluminescent MIP@g-CQD as a pH-responsive nano-carrier, MTX was loaded into MIP@g-CQD by soaking in a drug solution and the release behavior of the loaded drug was evaluated in the necessary pH values (7.4, 5). The successful synthesis of materials was characterized using PL, TEM, FE-SEM, DLS, and FT-IR analyses. Interestingly, the created cavities in the core-shell nano-carriers can interact with the MTX molecules effectively, leading to an increase in the loading capacity. According to the obtained results from Langmuir adsorption isotherms, the imprinting factor was calculated (IF = 4.91). Also, the binding kinetics of MTX revealed the creation of particular recognition sites in the core-shell polymeric network. The MTX-loaded MIP@g-CQD displayed a low rate and limited release at the simulated physiological environment (pH 7.4, 37 °C), but it is increased at tumor tissue (pH 5, 41 °C) conditions, which can lead to long-term and sustained release of MTX in the desired target. This property of MIP@g-CQD could avoid the release of MTX in normal physiological conditions, decreasing the possible side effects of MTX drug. Owing to the existence of amide functional groups in the nano-carrier structure and its negatively charged nature, the MTT assay displayed desirable cytotoxicity against the breast cancer cell line (MCF-7) for the MTX-loaded nano-carrier. According to the obtained results, the prepared safe photoluminescent MIP@g-CQD with appropriate pH-responsivity has a high ability to be applied as an anticancer and bio-detection agent.

In vitro trypanocidal activities and structure-activity relationships of ciprofloxacin analogs.

Tropical diseases, such as African trypanosomiasis, by their nature and prevalence lack the necessary urgency regarding drug development, despite the increasing need for novel, structurally diverse antitrypanosomal drugs, using different mechanisms of action that would improve drug efficacy and safety. Traditionally antibacterial agents, the fluoroquinolones, reportedly possess in vitro trypanocidal activities against Trypanosoma brucei organisms. During our research, the fluroquinolone, ciprofloxacin (1), and its analogs (2-24) were tested against bloodstream forms of T. brucei brucei, T. b. gambiense, T. b. rhodesiense, T. evansi, T. equiperdum, and T. congolense and Madin-Darby bovine kidney cells (cytotoxicity). Ciprofloxacin [CPX (1)] demonstrated selective trypanocidal activity against T. congolense (IC50 7.79µM; SI 39.6), whereas the CPX derivatives (2-10) showed weak selective activity (25 < IC50 < 65µM; 2 < SI < 4). Selectivity and activity of the CPX and 1,2,3-triazole (TZ) hybrids (11-24) were governed by their chemical functionality at C-3 (carboxylic acid, or 4-methylpiperazinyl amide) and their electronic effect (electron-donating or electron-withdrawing para-benzyl substituent), respectively. Trypanocidal hits in the micromolar range were identified against bloodstream forms of T. congolense [CPX (1); CPX amide derivatives 18: IC50 8.95µM; SI 16.84; 22: IC50 5.42µM; SI 25.2] and against T. brucei rhodesiense (CPX acid derivative 13: IC50 4.51µM; SI 10.2), demonstrating more selectivity toward trypanosomes than mammalian cells. Hence, the trypanocidal hit compound 22 may be optimized by retaining the 4-methylpiperazine amide functional group (C-3) and the TZ moiety at position N-15 and introducing other electron-withdrawing ortho-, meta-, and/or para-substituents on the aryl ring in an effort to improve the pharmacokinetic properties and increase the trypanocidal activity.

CHARACTERISATION OF EGG WHITE-IMPREGNATED ACTIVATED CARBON FOR CO2 ADSORPTION APPLICATION

In this study egg white was used as a source of natural amino acids to modify the surface properties of palm shell activated carbon towards enhancing its CO2 capture performance. A simple impregnation method was employed for this purpose. Characterisation analysis was performed on the egg white-impregnated activated carbon to examine any changes on its surface properties prior to CO2 adsorption test. The modified adsorbent showed high thermal stability below 300°C and comprised of new amide functional group. Furthermore, the modified adsorbent exhibited 31% higher breakthrough time and maintained its CO2 adsorption capacity at 0.3 mmol/g in comparison to raw activated carbon, regardless of the reduction of surface area and micropore volume by 17% and 18% respectively. These findings provide evidence on the prospect of egg white-impregnated activated carbon for CO2 adsorption application which could pave the way for a new generation of affordable and eco-friendly adsorbents.

Novel inhibitor N-cyclopropyl-4-((4-((4-(trifluoromethyl)phenyl)sulfonyl)piperazin-1-yl)methyl)benzamide attenuates RANKL-mediated osteoclast differentiation in vitro

Both cyclopropyl amide and piperazine sulfonamide functional groups are known for their various biological properties used for drug development. Herein, we synthesized nine new derivatives with different substituent groups incorporating these moieties and screened them for their anti-osteoclast differentiation activity. After analyzing the structure–activity relationship (SAR), the inhibitory effect against osteoclastogenesis was determined to be dependent on the lipophilicity of the compound. Derivative 5b emerged as the most effective dose-dependent inhibitor after TRAP staining with an IC50 of 0.64 µM against RANKL-induced osteoclast cells. 5b was also able to suppress F-acting ring formation and bone resorption activity of osteoclasts in vitro. Finally, well-acknowledged gene and protein osteoclast-specific marker expression levels were decreased after 5b administration on primary murine osteoclast cells.

Light-Induced Transformation of Virus-Like Particles on TiO2.

Titanium dioxide (TiO2) shows significant potential as a self-cleaning material to inactivate severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and prevent virus transmission. This study provides insights into the impact of UV-A light on the photocatalytic inactivation of adsorbed SARS-CoV-2 virus-like particles (VLPs) on a TiO2 surface at the molecular and atomic levels. X-ray photoelectron spectroscopy, combined with density functional theory calculations, reveals that spike proteins can adsorb on TiO2 predominantly via their amine and amide functional groups in their amino acids blocks. We employ atomic force microscopy and grazing-incidence small-angle X-ray scattering (GISAXS) to investigate the molecular-scale morphological changes during the inactivation of VLPs on TiO2 under light irradiation. Notably, in situ measurements reveal photoinduced morphological changes of VLPs, resulting in increased particle diameters. These results suggest that the denaturation of structural proteins induced by UV irradiation and oxidation of the virus structure through photocatalytic reactions can take place on the TiO2 surface. The in situ GISAXS measurements under an N2 atmosphere reveal that the virus morphology remains intact under UV light. This provides evidence that the presence of both oxygen and UV light is necessary to initiate photocatalytic reactions on the surface and subsequently inactivate the adsorbed viruses. The chemical insights into the virus inactivation process obtained in this study contribute significantly to the development of solid materials for the inactivation of enveloped viruses.

Structural arrangement, electroconductivical and electrochemical behaviours of solid amino acid-based electrodes

This paper presents the study on the structural dependence of the electroconductivity and electrochemical activity of model amino acids, aspartate and glycine, which are used as solid electrodes in hybrid capacitor systems. It has been established that the presence of carbonyl, aliphatic, and amide functional groups on the surface enhances the electrochemical activity and electrical conductivity. The frequency dependence of conductivity is typical for polymer compounds with a proton conduction mechanism, which is provided by the surface migration of the charge. It was found that deposition on the surface of carbon templates of the amino acids in the formation of biocomposites increases the number of active reaction centers and provides effective electronic charge transport. As a result, it leads to a significant increase in the contribution of pseudocapacitance and capacitance processes. The electrochemical activity was caused by the pseudocapacitive accumulation of charge due to the course of redox reactions with amino acids and capacitive accumulation of charge, which occurs with the participation of amino acids and carbon templates. It has been proven that the porous structure of the carbon nanotubes provides a more dispersed and uniform distribution of amino acids on the surface, which is ensured in the growth of pseudocapacitive charge accumulation.

Keratin hydrolysate as a chrome exhaust aid and keratin filler in leather processing: A cleaner technology approach for tannery solid waste management and leather manufacturing

Hair burning unhairing and dampening of tannery wastes during the hair-saving unhairing process are becoming significant problems in the tanning industry. Therefore, this research article focuses on the extraction of keratin hydrolysate (KH) and its application as a chrome exhaust aid and keratin filler in leather manufacturing process. The structure, morphology and functional groups of the extract were examined using X-Ray Diffractometer (XRD), scanning electron microscopy (SEM) and Fourier transform infrared spectrometer (FTIR), respectively. To study and contrast the degree of improvement in chromium uptake, the KH solution was applied both before tanning on the pickled pelt and after tanning during basification. The thermal stability, physical strength characteristics and organoleptic properties of the leathers obtained were characterized. Furthermore, the environmental impact of the tanning system was assessed through a comparative analysis of the spent liquors. Finally, experimental retanning process was conducted to replace the commercial protein filler (Celatan F: 50, 75, and 100 %) with KH solution, with concurrent processing of control leather using conventional chrome tanning agent at 6 % dosage of chromium. The FTIR analysis of the extract confirmed the presence of alkyl side chains of amino acids as well as carboxylic, amide, carboxyl group and aldehyde functional groups at 1400-1700 cm−1,3,303.46 cm−1,3270 cm−1 and 2752 cm−1, respectively. XRD spectrum showed two diffraction peaks at 2 theta values of 9.36° and 21.16°, respectively. Leathers with improved mechanical strength, organoleptic properties and thermal stability were obtained with 100 % substitution of Celatan F at pH 6 and 10 % chromium dosage. It was also discovered that the shrinkage temperature of the experimental leather was enhanced to more than 105 °C. Environmental impact evaluation on the spent liquor showed that the complete replacement of Celatan F with KH solution brought about a notable decrease in COD and TDS in the spent liquor. The extraction and application of tannery hair waste-based keratin hydrolysate as an efficient, environmentally friendly chrome exhaust aid and keratin filler has been attempted and established in this research article.

A solid-state sensor based on nanosilica/methylcellulose composite and chromoionophore 8-carboxamidoquinoline derivative as an optode pellet for Zinc(II) ion

Zinc is known to play a central role in the immune system that creates a resistance barrier against viral infection. A naked-eye zinc(II) (Zn2+) ion sensor of 2-oxo-2-(quinolin-8-ylamino)acetic acid (OQAA) as a recognition probe was designed and synthesized. By inserting functional groups of amide and carboxylic acid into a conjugated molecule of 8-aminoquinoline, Zn2+ ion (borderline acid) coordinated favorably with aromatic nitrogen atoms (borderline bases) and N-amide. Characterization of OQAA was done by FTIR, 1H NMR, 13C NMR, UV–vis, and ESI-MS. The Zn2+ ion chemosensor was fabricated by immobilizing OQAA chromogenic ionophore onto a nanosilica/methylcellulose (Si/MC) composite pellet to form a solid-state pellet sensor. A distinguishable color change from pale light-yellow to yellowish-brown of the optode pellet was observed in the presence of Zn2+ ions. Optimization of the pellet-based Zn2+ ion sensor was carried out with a fiber optic reflectance spectrophotometer at 0.25 M OQAA in tris buffer (pH 7.4). The optical fiber sensor demonstrated a linear reflectance response between 0.8 M and 2.4 M Zn2+ ion (R²=0.9741) at λmax=635 nm with a limit of detection (LOD) of 3.6 × 10−2 M and response time of 5 min. The reflectance sensor exhibited good selectivity towards Zn2+ ion over other competitive heavy metals e.g., iron(II) (Fe2+), nickel(II) (Ni2+), cobalt(II) (Co2+), copper(II)(Cu2+) and cadmium(Cd2+) ions. Additionally, the proposed Zn2+ ion sensor showed high shelf-life stability of 75 days operational duration with 80.0 % initial optical response remaining. The quick, easy, and uncomplicated preparation of the OQAA-modified Si/MC (OQAA-Si/MC) composite pellet novel material gave a reproducible reflectance signal towards the determination of Zn2+ ion concentration with a low relative standard deviation (RSD) obtained at ∼1.0 % (n=12), and was reusable three times for assay of Zn2+ ion (RSD=1.3 %). The optical chemosensor imparts remarkable color change towards the analysis of Zn2+ ions, and could offer direct and fast in-situ visual inspection of Zn2+ ion levels in complex samples without an instrument.

Preparation and characterization of poly (lactic acid)-chitosan blend fibrous electrospun membrane loaded with bioactive glass nanoparticles for guided bone/tissue regeneration

In this study, bioactive fibrous membranes composed of poly (lactic) acid (PLA), chitosan (CHS), and strontium-doped bioactive glass nanoparticles (BG) were produced via electrospinning technique using a triple solvent system and characterized via thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), static contact angle (CA), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX).All fiber samples exhibited consistent one-step thermal degradation profiles, regardless of BG content, and the intended BG contents in the membranes ware confirmed. The addition of 3% w/w CHS to form PLA-CHS blend lowered the glass transition temperature (Tg) by 1.62 °C. FTIR analysis validated the presence of CHS in the PLA-CHS blend fibers through the appearance of a low-intensity broad peak around 1658–1566 cm⁻1, indicating primary amide functional groups. Incorporating 3% w/w CHS reduced water contact angle by 7% and decreased fiber diameter by 57%. Wettability improved with increasing BG content, as confirmed by SEM images showing well-dispersed BG nanoparticles within the fibers.After 35 days of immersion in simulated body fluid (SBF), a substantial layer of hydroxyapatite (HA) with a Ca/P ratio resembling that of natural human bones coated the BG particles and fibers. The membranes demonstrated excellent cell adhesion capabilities, especially in the PLA_3%CHS and PLA_3% CHS_5% BG configurations, with minimal cellular toxicity compared to a well-known cell-killing agent, highlighting their biocompatibility.Incorporating chitosan and strontium-doped bioactive glass nanoparticles into PLA blends positively influenced cell viability and proliferation, emphasizing the enhanced cellular response resulting from surface modifications. These properties make these fibrous membranes promising for guided bone and tissue regeneration applications.

A Polymer‐Functionalized GO Composite Prepared through Pickering Emulsion Polymerization for Selective Removal of Zr from Acidic Solutions

AbstractFor the selective removal of Zr from PUREX originated acidic aqueous waste of metallic fuel, an adsorbent based on graphene oxide (GO)‐polystyrene composite functionalized with amide functional group was developed. Improved Hummers’ oxidation of graphite powder was utilized to produce GO and the amide moiety was linked to GO via chemical functionalization. The amide modified GO was converted to GO‐polystyrene composite microspheres through pickering emulsion assisted route. FT‐IR, XRD and SEM analyses were employed to characterize the composite adsorbent. The adsorption behavior of Zr was examined under varying experimental conditions. Adsorption was modeled using several adsorption and kinetic models. The Zr adsorption capacity calculated based on the Langmuir adsorption isotherm and Pseudo‐first‐order models exhibited a close agreement. Adsorption studies using simulated U‐Pu‐Zr originated PUREX aqueous waste signifies the superior Zr‐adsorption capacity (~50 mg g−1), even in the presence of other possible interfering elements present in SHLLW.

Coalescence of Porous Coordination Cages into Crystalline and Amorphous Bulk Solids.

Discrete porous coordination cages are attractive as a solution processable material whose porosity is not predicated on a network structure. Here, we leverage the peripheral functionalization of these cage structures to obtain 12 novel, solution processable, porous coordination cages that afford crystalline and amorphous single-phase millimeter-scale monolithic bulk structures (six of each) upon solidification. These structures are based upon prototypal metal-organic polyhedra [Cu24(5-x-isophthalate)24] (where x = NH2, OH), wherein meta-substitution of linker ligands with acyl chloride or isocyanate moieties afforded amide and urethane functional groups, respectively. These porous cage structures were obtainable via direct synthesis between a metal salt and a ligand as well as postsynthetic modification of the cage and formed monoliths following centrifugation and drying of the product. We rationalize their self-assembly as colloidal packing of nanoscale cuboctahedral cages through weak interactions between their hydrophobic alkyl/aromatic surfaces. In general, amorphous solids were obtained via rapid precipitation from the mother liquor upon methanol addition, while crystalline solids could be obtained only following further chloroform and pyridine additions. The structure of the materials is confirmed via gas sorption and spectroscopic methods, while powder X-ray diffraction and transmission electron microscopy are used to determine the nature of these bulk solids.