جستجوی مقالات مرتبط با کلیدواژه "5" در نشریات گروه "شیمی"

The increasing demand for sustainable materials has spurred interest in nanocellulose derived from natural sources. This study focuses on synthesizing nanocellulose from coconut fiber through enzymatic hydrolysis using cellulase enzymes. To optimize the production process, a cellulase concentration of 1500 U/mL was utilized, with varying enzyme volumes (100, 200, 300, 400, and 500 µL). The pretreatment steps included delignification with 10% NaOH and bleaching with 40% H2O2, facilitating cellulose extraction. Comprehensive analysis revealed that the coconut fiber contained 42.95% alpha-cellulose, 72.51% holocellulose, 29.56% hemicellulose, and 22.77% lignin. Optimal nanocellulose size (NSSK) of 10.21 µm was achieved with the addition of 400 µL cellulase enzyme, indicating an efficient enzymatic breakdown of the fiber. Scanning Electron Microscopy (SEM) characterized a non-uniform morphology with fine fibers and surface irregularities. Fourier Transform Infrared Spectroscopy (FTIR) results showed significant chemical changes, including a reduction in peak intensity at 1728 cm cm-¹, a shift in the peak from 1600 cm-¹ to 1598 cm-¹, and an enhanced peak within the range of 1028-1050 cm-¹. These alterations suggest effective modification of lignin and hemicellulose, confirming the successful production of eco-friendly nanocellulose from coconut fiber. The findings underscore the potential of utilizing coconut fiber as a renewable resource for nanocellulose production, paving the way for sustainable applications in various industries.

The aim of this study is to investigate the effects of incorporating the synthetic dye 2,2-dicarboxylic 4,4-bipyridine into dye-sensitized solar cells (DSSCs) that utilize a porous silica substrate. To achieve this, the synthetic dye is first prepared and subsequently applied during the fabrication of the solar cell onto the porous silica base. The porous silica substrate possesses unique attributes such as a large surface area, mechanical and thermal stability, and sizable pores, which enhance the photocatalytic properties of the synthetic dye. In this project, a conductive layer of tin oxide, approximately 45 nm thick, is deposited onto the porous silicon substrate. Following this, a thin layer of titanium oxide, around 100 nm in thickness, is sprayed onto the substrate as a secondary layer. The synthetic dye 2,2-dicarboxylic 4,4-bipyridine serves as the light-sensitive pigment in this type of solar cell, and a graphite coating is applied as a conductive layer between the two layers. The electrolyte solution utilized in this cell is potassium iodate. In addition, the various stages of the solar electrode production process were examined using X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques, and the energy efficiency components were calculated based on the amount of emitted light.

Nanocatalysts are at the forefront of revolutionizing green chemistry by enhancing the efficiency, selectivity, and sustainability of chemical processes. This study explores the fundamentals of nanocatalysts, their characterization techniques, and their pivotal role in promoting environmentally friendly chemical reactions. Key applications in environmental remediation, renewable energy, and sustainable industrial processes underscore their versatility and impact. Innovations in emerging materials, such as two-dimensional nanomaterials, metal-organic frameworks, high-entropy alloys, and single-atom catalysts, are pushing the boundaries of catalytic performance. The document also addresses challenges related to technical, economic, and environmental aspects, proposing solutions like cost-effective production methods, improved safety protocols, and regulatory updates. The importance of robust policy and regulatory frameworks is emphasized to ensure the safe and responsible development of nanocatalysts. Looking ahead, advancements in material science, integration with emerging technologies, enhanced sustainability practices, broader applications, strengthened regulatory frameworks, public and industry engagement, and interdisciplinary collaboration will shape the future of nanocatalysts in green chemistry. This comprehensive overview highlights the transformative potential of nanocatalysts in creating sustainable and impactful chemical processes, contributing to a greener and more sustainable world.

Microorganisms cause Microbial Keratitis, an active inflammation of the cornea. Pseudomonas aeruginosa, Staphylococcus epidermidis, and Candida albicans are pathogenic microorganisms that frequently infect human eyes related to contact lens use. The biofilm can be controlled by utilizing phytochemical compounds from plants. One of the plants that contains phytochemical compounds and shows potential as an antimicrobial and antibiofilm agent is the butterfly pea flower (Clitoria ternatea L). This study aims to demonstrate the effectiveness of the butterfly pea flower (Clitoria ternatea L) as a potential antibiofilm agent in the degradation biofilms of Pseudomonas aeruginosa, Staphylococcus epidermidis, and Candida albicans that grow on contact lenses. The antibiofilm testing uses the Microtiter Plate Biofilm Assay method to determine the ability of microbes to grow on contact lenses and the degradation of biofilms with the addition of butterfly pea flower extract. Biofilms are examined by measuring optical density at 595 nm using a microplate Elisa reader. The results of the study show biofilm degradation on contact lenses by Pseudomonas aeruginosa (54.01%±0.046), Candida albicans (63.54%±0.093), and Staphylococcus epidermidis (45.27%±0.026). In conclusion, butterfly pea flower (Clitoria ternatea L) extract has high effectiveness as an antibiofilm agent against Pseudomonas aeruginosa and Candida albicans and moderate effectiveness against Staphylococcus epidermidis.

Nanostructured enzyme mimics are of great interest as promising alternatives to artificial enzymes for biomedical and catalytic applications. Studying the chemical interactions between antioxidants and nano-enzymes may result in a better understanding of the capability of antioxidants and may help improve the function of artificial enzymes to better mimic natural enzymes. In this study, using palladium nanoparticles (PdNPs) as peroxidase mimics to catalyze the oxidation of chromophoric substrates by H2O2, we developed a platform that acts as a biosensor for hydrogen peroxide and glucose and that can study the inhibitory effects of natural antioxidants on peroxidase mimics.The peroxidase-like activity of Butea monosperma reduced Palladium nanoparticles was assessed through using 3',3',5',5'-tetramethyl benzidine(TMB) as a chromogen in the presence of H2O2. Butea Monosperma reduced palladium nanoparticles BM-PdNPs catalytically oxidize TMB using H2O2, resulting in the production of a blue oxidation product. This product was measured and quantified using a UV-Vis spectrophotometer at a wavelength (λmax) of 652 nm. The pH, temperature, and nanoparticle concentration are crucial factors in investigating the catalytic activity of BM-PdNPs. The glucose oxidase enzyme catalyzes the production of gluconic acid, resulting in the release of H2O2 as a byproduct which can be subsequently be measured using BM-PdNPs. Under optimal conditions, the method exhibited a linear range of 1.5 µM to 1000 µM for glucose determination. The limit of detection (LOD) calculated using the equation 3σ/m, was found to be 0.78 μM. The authenticity of the results obtained from BM-PdNPs was confirmed through the use of UV-Vis, Fourier Transform Infrared Spectroscopy (FTIR) and Transmission Electron microscopy (TEM)

In this study, the adsorption efficiency of a low-cost biodegradable adsorbent, poly (AAC-co-AM)/AC biocomposite hydrogel prepared by a green method using free radical copolymerization was studied to remove heavy metals such as copper ions. Several analyses of the hydrogel were performed, such as field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). The effect of some optimal conditions, such as copper ion concentration, equilibrium time, hydrogel weight, and solution temperature, was studied in the batch model. The adsorption of copper ion increased from 73.25% to 92.91% with a rising weight of hydrogel (0.01-0.1 g/50 mL) but with the increase in weight of the hydrogel, degrease the adsorption efficiency from 27.14 to 219.14 mg/g at a fixed concentration of copper ion 30 mg/L, equilibrium time of 1 h, temperature 25 °C, and agitation speed 150 rpm. Finally, as the temperature increases, the adsorption efficiency and removal percentage increase. Adsorption equilibrium studies were investigated by Langmuir and Freundlich isotherm models. The Freundlich model provided the result with better efficiency (Qe=84.567 mg/g). Calculations of non-covalent interaction, RDG, and Quantum chemical parameters are used in this study to confirm the real binding between metal ions and surfaces.

The electrochemical method of recovering tungstic acid uses nitric acid as the electrolyte. At the anode, carbide material is oxidized, yielding insoluble tungstic acid (H2WO4) and cobalt ions in the solution. Tungstic acid is then used to make tungsten oxide (WO3), a valuable industrial material. Initially, experiments in this study were prepared and carried out using experimental design approaches and grey relational analysis (GRA), which was based on the Taguchi method and carried out using Minitab17 software. Datafit (Versions 9.1) software was used to create regression models for predicting weight loss and energy usage. The goal function of the tests was anode weight loss/hour and electrochemical cell power consumption, whereas the impacting variables were current density, electrolyte concentration, cell temperature, and cathode electrode type. The optimal electrochemical cell has a current density of 4000 A/m2, 1.8 M electrolyte concentration and 70 °C cell temperature, and an aluminum cathode.

This study focuses on the synthesis and characterization of lanthanum-doped fluorapatite compounds, Pb(8-x)Na2Lax(PO4)6Fx, with varying lanthanum content (𝑥=0.0; 0.5; 1.0; 1.5; 2.0). The compounds were synthesized using a solid-state reaction method at 850°C and for 50 hours. The X-ray diffraction results confirmed the formation of a highly crystalline hexagonal apatite structure with phase purity in all the synthesized compositions. The calculated lattice parameters (a and c) and unit cell volume (V) decreased systematically for higher lanthanum contents, suggesting successful incorporation of the lanthanum ions into the lattice. Characteristic vibrational modes of phosphate groups (PO43-) are evident in the FTIR spectra, with minor shifts in peak positions due to substituted lanthanum cations. The results agree with what has been reported in the literature and confirm the structural integrity and chemical purity of the synthesized materials. The findings show that the primary apatitic structure could be retained in the case of lanthanum-doped fluorapatite compounds. Still, the material could have better or improved properties to tailor the same for various technological functions such as catalysis, ion exchange, and biomedical engineering. This work provides a sound underpinning to explore further the functional properties and alternative synthesis routes toward optimized material performance.

Selective cyclooxygenase-2 inhibitors have gained prominence in anti-inflammatory drug development due to their potential to reduce inflammation while minimizing the gastrointestinal toxicity associated with non-selective NSAIDs. This study focuses on the synthesis, molecular docking, characterization, and evaluation of new 3-ethyl-1H-indole derivatives containing imidazolidinone pharmacophores as selective COX-2 inhibitors aimed at improving GI safety. Molecular docking studies predicted strong binding affinities for the synthesized compounds, with scores ranging from -11.35 to -10.40 kcal/mol, significantly higher than the reference drug meloxicam (-6.89 kcal/mol). The compounds were structurally confirmed using FT-IR and ¹H-NMR spectroscopy. ADME predictions further validated the drug-likeness and favorable pharmacokinetic profiles of the synthesized compounds. Preliminary in vivo anti-inflammatory activity was assessed using an egg-white-induced paw edema model in rats, where the compounds significantly reduced inflammation compared to ibuprofen. Compound IIb demonstrated the highest efficacy, with a prolonged reduction in paw edema. These findings indicate that the newly synthesized indole derivatives have potential as selective COX-2 inhibitors with promising anti-inflammatory properties and improved GI safety. Future studies will focus on further toxicity and enzymatic inhibition assays to fully characterize their safety and therapeutic potential.

The contamination of water bodies by organic dyes is a major environmental issue that requires improved methods for water purification. Traditional water treatment methods often fail to degrade these persistent pollutants effectively. This study aims to synthesize and characterize Fe3O4/tetraethyl orthosilicate (TEOS) composite in combination with TiO2 anatase for photodegradation of methylene blue (MB). The coprecipitation method was employed for the synthesis process. The X-Ray Diffraction (XRD) analysis reveals changes in the crystal diameter with the addition of TEOS and TiO2. In addition, the Scanning Electron Microscope (SEM) results indicate an average particle size change from 1835.65 (Fe3O4/TEOS) to 1339.7 nm (Fe3O4/TEOS/TiO2) due to the addition of TiO2. In addition, Fourier Transform Infrared (FTIR) analysis confirms the Fe-O functional group's presence, indicating the material's magnetic nature. In addition, Si-O-Si and Si-O-Ti functional groups suggest an interaction between TEOS and TiO2, forming new Si and Ti bonds. Vibrating Sample Magnetometer (VSM) analysis shows an increase in the saturation value (Ms) and remanence value (Mr) while the coercivity value (Hc) decreases. These results suggest that the sample exhibits characteristics of both hard magnetic and superparamagnetic materials. Furthermore, UV-Vis analysis results demonstrate the MB degradation using Fe3O4/TEOS/TiO2 with a photodegradation efficiency of 98.47% for 0.5 h. Kinetic studies reveal that the degradation of MB follows second-order kinetics, with a rate constant of 2.125 ppm-¹ hour-¹.

This study presents a comparative investigation into the multidentate bis(semicarbazone) ligand, (2Z,2’E)-2,2’-(((propane-1,3-diylbis(oxy))bis(2,1-phenylene))bis(methanylylidene))bis(hydrazine-1-carboxamide) (H₂L), and its precursor L. The synthesis of L involved a two-step process: the formation of potassium 2-formylphenolate, followed by a reaction with 1,3-dibromopropane. H₂L was synthesised through the reaction of L with semicarbazide in a 1:2 mole ratio. Comparative analysis between L and H₂L was carried out using various analytical and spectroscopic techniques, including FT-IR, UV-Vis, mass spectrometry, 1H- and 13C-NMR, elemental analysis and melting points. Further comparative studies explored their thermal properties, Density Functional Theory (DFT) simulations, and molecular docking. DFT simulations using the B3LYP functional at the 6-311++G(d,p) level provided insights into the stability, electronic properties, and geometries of both compounds. Molecular docking studies against drug discovery targets 5IQ9 and 5VBU revealed comparative binding energies and interaction profiles, indicating potential dual inhibitory effects. Significantly, biological assessments showed that while L exhibited moderate antibacterial activity, H₂L demonstrated improved antifungal efficacy, particularly against Candida albicans, highlighting its potential as a therapeutic alternative.

This study developed for synthesis of some novel photocatalytic nanocomposites from nano graphitic carbon nitride(g-C3N4), nano bismuth oxide (Bi2O3) and nano-graphene oxide (NGO) due to degradation of methylene blue dye as an organic pollutant in waste water. These synthesized novel ternary nanocomposites including BiC80/GO, BiC80/GO, BiC80/GO and BiC80/GO which characterized by FTIR, UV–Vis, XRD, PL, TGA, FESEM, and EDS to study of thermal stability, surface morphology, and purity of nanocomposites. The degradation efficiency (D%) for nano materials and novel ternary nanocomposites, under the visible light irradiation in a time period of 180 min was investigated in this work. The optimum conditions obtained for preparation of ternary nanocomposites BiC80/GO (20 mg), are 50 mg catalyst and 5 ppm dye concentration at 35 °C in pH 12.

Synthesized MnO2 nanoparticles created a trickling bed electrochemical reactor (TBER) for H2O2 electrogeneration. This reactor has a porous cathode bed made of MnO2 nanoparticles and PTFE as a conductive binder. Cathode beds and electrolytes are needed to run the reactor. Co-precipitation produces MnO2 nanoparticles combined with PTFE to form the cathode bed. The synthesized catalyst was characterized using X-ray diffraction (XRD), Transmission electron microscopy (TEM), Scanning electron microscopy (SEM), and FTIR. This change increases H2O2 concentration by more than twice that of a single cathode bed. The effective mass transfer of oxygen from the gas phase to the electrolyte cathode interface and the uniform distribution of electrolyte and oxygen throughout the cathode bed were thought to increase cathode bed performance. The TBER electrochemically reduced oxygen in concentrated alkaline and acid electrolytes to produce H2O2. H2SO4 acid was more stable as an electrolyte; however, the maximum H2O2 concentration was 16.32 mM at 0.5 M. When using 0.25 M KOH as an electrolyte quickly, a high concentration of 36.56 mM was detected. Therefore, we observed H2O2 generation from the first minute of the reaction until the steady state duration of 15 minutes. Wastewater treatment, CO2 reduction, chemical manufacturing, and desulfurization are prospective commercial uses of the findings

A one-step green synthesis involving highly stabilized silver nanoparticles (AgNPs) was achieved by employing the extract of Piper nigrum (black pepper) as both a reducing and capping agent in an aqueous medium without the need for any additional chemicals. The UV-Visible spectrum indicated the presence of AgNPs. X-ray diffraction examination revealed the creation of silver nanoparticles (AgNPs) with a face-center cubic structure. The FT-IR spectra were utilized to determine the functional groups. This photosynthetic approach is simple, cost-effective, replicable, and environmentally friendly. Tested the biological activity and anticancer as prostate cancer PC3 cell line

In this work, some new heterocyclic compounds will be synthesized from Imidazole as starting material via the reaction with ethyl chloro acetate to produce compound (1), and then treated with hydrazine hydrate to yield compound (2), compound (2) react with substituted aromatic aldehyde to produce compound (3). This compound will react with sodium azide to produce compound (4). The newly synthesized compounds identified by FTIR,1H-NMR,13C-NMR, and their physical properties measured and biological activity estimated for compounds.

Bis-phosphonic acid and bis-phosphonate derivatives are a diverse group of natural and synthetic compounds, they exhibit interesting physiological activities and are therefore considered as potential therapeutics in modern medicine. They have found applications as antibacterial, antiviral and as anti-osteoporosis drugs. The present work deals with the preparation of novel Schiff base derivatives linked to inorganic bis-phosphonate groups by reacting the parent compound: Bisphosphonic acid (4-aminophenyl) (hydroxyl) methylene (2) with a variety of aldehydes and ketones. The parent reactant and its condensation products (3a-3j) were identified by physical and spectroscopic techniques, namely; FT-IR, 1H-, 13C-, and 31P-NMR. The antibacterial activity of these derivatives were studied by disk diffusion method and found to possess high in vitro antimicrobial activity against gram-positive and gram-negative bacteria viz. Staphylococcus aureus, Bacillus anthraces, Escherichia coli and Acinetobacter species, referenced to azithromycin and levofloxacin.

Three new Schiff bases (L1–L3) were produced from 4-aminoantipyrine. In the first step, 4-aminoantipyrine reacted with three distinct aldehydes; and in the second step, the obtained compound interacted with 1H-1,2,4-thriazolo-3,5-diamine to produce the desired compounds. Elemental analysis (CHN), 1H-NMR, 13C-NMR, and infrared spectra transformed using Fourier transform (FT-IR) were used to evaluate the properties and structures of ligands. The 6-31G+ (d,,p) basis set, the DFT-based B3LYP approach, and the Gaussian 09 software program served as the foundation for the theoretical explanations. In addition, one of the produced molecules has good antioxidant activity when tested for antioxidant activity using the DPPH scavenger.

In this study, a new triazole and oxadiazole derivatives were synthesized from reaction of compound (1) with NH4CSN at (180-200) °C were prepared compound (2) in the first step and in the second step, compound (1) was reacted with Cs2 in the KOH presence to produced of the 5-mercapto 1,3,4-oxadiazole derivative. Likewise, in third step, compound (1) was reacted with various substituted benzoic acids in the POCl3 presence to produce amide derivatives 4(a-e). In final step, synthetic amides were cyclized in the presence of H2SO4 con. to generate 1,3,4-oxadiazole derivatives 5(a-e). The prepared compounds were characterized using FT-IR, 1H-NMR spectroscopy, and studied biological activity of the prepared compounds against Escherichia coli and Staphylococcus aureus as well as antifungal activity. In addition, the molecular docking properties of these compounds were also investigated.

Compound C11H12NO2F was obtained by reacting of 4-fluoroaniline with methyl acetoacetate, using CoCl2 as a catalyst. X-ray structural analysis identified the structure of the synthetized enaminoester, and infrared spectroscopy and proton NMR complemented it. The β-enaminoester crystallized in the P21/c space group, which is symmetrical and monoclinic (Z=4) [a=6.5919(3)Å, b=15.9809(8)Å, c=10.1859(4)Å, β=105.3300(16) °; V =1034.85 Å3]. The crystal structure consists of alternating up and down C11H13NO2F molecules staked along with the b-axis. Van der Walls interactions keep the crystal structure together by looking at the weak hydrogen bonds of the N-H-O and C-H-O types inside the molecule. A high-level Density Functional Theory computation was performed on the investigated molecule, which was found to have a substantial correlation with the experimental data. Because of their high accuracy in determining the geometric structure of molecules, the B3LYP function and the 6-311+ G(2d,3p) basis set were chosen. The molecule chemical reactivity was evaluated by creating its Frontier Molecular Orbitals (FMOs) and the Molecular Electrostatic Potential surfaces (MEP). The global reactivity descriptors were computed using the FMOs energy levels, gaining further insight into the molecule's reactivity. The local reactivity was assessed by calculating the Fukui functions and dual descriptor indices. Analyses of Hirshfeld surface mapped over dnorm and shape-index were further used to identify the intermolecular interactions. The fingerprint histograms allow to show that H ···H (46.7%), O ···H (16.7%), and F ···H (14.2%) contacts are the dominant interactions in the crystal packing of the investigated molecule.

Innate immunity, along with cytokines like interleukin (IL)-15 and interferon, is a key factor in the development of celiac disease (CD). A T-bet is a distinct factor in T-box transcription. IFN gamma expression is correlated with T-box transcription in Th1 and natural killer cells. In an active CD, T-bet transcription is controlled. The present study aims to assess how intraepithelial lymphocytes (IELs) stained with T-bet are distributed in patients with celiac disease (CD). 250 patients took part in this trial. By integrating clinical pathology features, the CD was determined to be the most likely diagnosis for these patients. According to standard procedure, a duodenal biopsy was applied to formalin-embedded paraffin (FFPE) blocks. The slices were prepared and stained using T-bet hematoxylin and eosin (H and E). It was assessed how intraepithelial lymphocytes were distributed. By analyzing the results using the IBM (SPSS) program, it was found that there is a strong relationship between the number of T-bet-stained cells and the increase in intraepithelial lymphocytes (p-value = 0.001), where the distribution IEL was standard.