Fourier Transform Infrared Spectroscopy Results Research Articles

Pulsed electric field using the needle–needle electrodes for improving the salt diffusion of pork brine salting

Pulsed electric field (PEF), as an emerging nonthermal processing technology, has attracted extensive attention and research in food processing. In the present study, PEF has been approved that has the potential to enhance salt diffusion in pork. In this study, pork lions were pretreated with PEF before being immersed in the brine (5% NaCl [w/w]) at 4°C to investigate the effect of needle-needle PEF pretreatment on pork brine salting. The changes in the weight, moisture, and salt content were detected during the salting process. The effective diffusion coefficient (De) and mass transfer kinetics were calculated.Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were subsequently used to analyze the microstructure of the pork and the secondary structure of myofibrillar proteins (MPs). The outcomes demonstrated that after brining for 8h with PEFpretreatment, the weight, moisture, and salt changes increased significantly. The central salt content achieved by 12h brining after PEF treatment (4.5kV) is equivalent to that achieved by brining for 20h without any treatment. The De was raised to 4.0×10-10 (PEF) from 3.1×10-10 (control).SEM and FTIR results revealed that PEF altered the microstructure of pork and the secondary structure of MP.Our study demonstrated that PEF generated by needle-needle electrodes could effectively promote salt diffusion and shorten salting processing.

Extraction, structural characterization, and antioxidant activity of polysaccharides derived from Arctium lappa L.

Arctium lappa L. root has high nutritional and medicinal values and has been identified as a healthy food raw material by the Ministry of Health of the People's Republic of China. In the present study, an aqueous two-phase system (ATPS) of polyethylene glycol (PEG)-(NH4)2SO4 was used to extract Arctium lappa L. polysaccharides (ALPs) from the Arctium lappa L. roots, the optimal extraction conditions of crude ALPs were optimized by using the single-factor experiment and response surface methodology. The structure and composition of ALPs were determined by fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and high-performance liquid chromatography (HPLC). At the same time, the antioxidant activity of ALPs was investigated by in vitro antioxidant experiment. The optimized extraction parameters for extraction ALPs were as follows: the PEG relative molecular weight of 6,000, a quality fraction of PEG 25%, a quality fraction of (NH4)2SO4 18%, and an extraction temperature of 80°C. Under these conditions, the extraction rate of ALPs could reach 28.83%. FTIR, SEM and HPLC results showed that ALPs were typical acidic heteropolysaccharides and had uneven particle size distribution, an irregular shape, and a rough surface. The ALPs were chiefly composed of glucose, rhamnose, arabinose, and galactose with a molar ratio of 70.19:10.95:11.16:6.90. In addition, the ALPs had intense antioxidant activity in vitro with IC50 values in the ·OH radical (1.732 mg/ml), DPPH radical (0.29 mg/ml), and superoxide anion (0.15 mg/ml) scavenging abilities. The results showed that ATPS was an efficient method to extract polysaccharides and could be used for the extraction of other polysaccharides. These results indicated that ALPs had great prospects as a functional food and could be exploited in multiple fields.

Isolation and Characterization of Fractionated Cellulose from Madhuca indica

AbstractThe present study proposes valorization of Mahua (Madhuca indica) seed cake for the isolation of cellulose nanocrystals (CNCs) to provide a sustainable and low‐cost precursor material to produce nano biomaterials aiming a sustainable conversion of waste material to value‐added products. The raw material was subjected to bleaching and alkali treatment to obtain cellulose, followed by acid hydrolysis for the isolation of CNC. The resultant nanocrystals were characterized for structural changes using Fourier transform infrared spectroscopy (FTIR), X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM). FTIR results showed progressive removal of non‐cellulosic components such as hemicellulose and lignin. This rendered CNCs with a 35 % yield along with higher crystallinity index of 85 % as determined by XRD. Thermo gravimetric analysis revealed that isolated CNCs have higher thermal stability (>200 °C). SEM images showed that the CNCs exhibit ultrafine microfibers like structures.

Probing the binding interactions between perfluoroalkyl carboxylic acids and adenosine A2A receptors by spectroscopic techniques, molecular simulations and quantum chemistry

The binding interactions of perfluorobutyric acid (PFBA), heptafluorobutyric anhydride (HFBA), and ethyl heptafluorobutyrate (NSC3936) with the adenosine A2A receptor (A2AR) were investigated using multiple-spectral (fluorescence, ultraviolet–visible (UV–Vis) absorption, three-dimensional (3D) fluorescence, and Fourier Transform infrared (FT-IR) spectroscopy) and computational simulation methods. Steady-state fluorescence and UV–visible spectroscopy indicated that PFBA, HFBA, and NSC3936 caused an intrinsic fluorescence quenching of A2AR by static quenching and non-radiative energy transfer. The results of 3D fluorescence and FT-IR spectroscopy showed that the presence of PFBA, HFBA, and NSC3936 induced changes in the secondary structure of A2AR. Combined with thermodynamic analysis, molecular docking and quantum chemistry investigations, our results suggest that the association of PFBA, HFBA, and NSC3936 with A2AR was driven by hydrophobic forces and the formation of hydrogen bonds (H-bonds). The binding constants for the three PFCAs studied range from 8.27 × 106 L·mol−1 to 1.80 × 107 L·mol−1 at 298 K. Molecular dynamics (MD) simulations indicated that A2AR formed stable complexes with PFBA, HFBA, and NSC3936, and validated the existence of electrostatic interactions in the HFBA-A2AR complex. Furthermore, the results from the MD simulations were consistent with the thermodynamic analysis results.

Enhancement of Glimepiride Bioavailability by Co-Crystallization Technique

Abstract: Drugs with low aqueous solubility show limited oral bioavaibility and dissolution enhancement is a promising strategy for improving drug bioavailability. Co-crystallization is a promising technique used to improve the oral solubility and dissolution rate of the drugs and hence their oral bioavailability. In general pharmaceutical co-crystals improve the physical properties such as crystallinity, solubility, wettability and dissolution behaviors of the drug without altering its pharmacological activity. The aim of this study was to enhance the solubility, dissolution rate and limited oral bioavailability of glimepiride (GLM) by cocrystallization with different carboxylic acid co-formers. Different co-crystal formulations were successfully prepared by ultrasound assisted suspension co-crystallization technique and then suspected to solubility study to choose the best formula to complete the study. Co-crystal of glimepiride -oxalic acid was characterized by X-ray Powder Diffraction (XRPD), Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM), and then further evaluated for dissolution behavior. The result showed that co-crystal could increase solubility and dissolution rate of glimepiride. The results of XRPD, FTIR and DSC indicating the presence of a new crystalline phase and formation of cocrystal while the SEM micrograph revealed the definite shape with crystalline composition of co-crystal. In vivo bioavailability study in rats showed higher Cmax , longer t1/2 el and MRT0-∞ and increased AUC0-∞ of 2.66 fold compared to the plain GLM. Therefore, co-crystallization technique can be expected to represent a promising tool for enhanced delivery of glimepiride.

Biogenic nanosilver bearing antimicrobial and antibiofilm activities and its potential for application in agriculture and industry.

Due to the increasing resistance of bacteria and fungi to antimicrobials, it is necessary to search for effective alternatives to prevent and treat pathogens causing diseases in humans, animals, and plants. In this context, the mycosynthesized silver nanoparticles (AgNPs) are considered as a potential tool to combat such pathogenic microorganisms. AgNPs were synthesized from Fusarium culmorum strain JTW1 and characterized by Transmission Electron Microscopy (TEM), X-ray diffraction (XRD), Fourier Transform Infrared (FTIR) spectroscopy, Nanoparticle Tracking Analysis (NTA), Dynamic Light Scattering (DLS) and Zeta potential measurement. The minimum inhibitory (MIC) and biocidal concentrations (MBC) were determined against 13 bacterial strains. Moreover, the combined effect of AgNPs with antibiotics (streptomycin, kanamycin, ampicillin, tetracycline) was also studied by determining the Fractional Inhibitory Concentration (FIC) index. The anti-biofilm activity was examined by crystal violet and fluorescein diacetate (FDA) assays. Furthermore, antifungal activity of AgNPs was evaluated against a panel of phytopathogenic fungi viz., Botrytis, Colletotrichum, Fusarium, Phoma, Sclerotinia, and an oomycete pathogen Phytophthora by agar well-diffusion and micro-broth dilution method to evaluate the minimal AgNPs concentrations that inhibit fungal spore germination. Fungi-mediated synthesis resulted in the formation of small (15.56 ± 9.22 nm), spherical and stable (zeta potential of - 38.43 mV) AgNPs with good crystallinity. The results of FTIR spectroscopy indicated the presence of various functional groups, namely hydroxyl, amino, and carboxyl ones, from the biomolecules on the surface of AgNPs. The AgNPs showed antimicrobial and antibiofilm formation activities against Gram-positive and Gram-negative bacteria. The values of MIC and MBC ranged between 16-64 and 32-512 μg mL-1, respectively. The enhanced effect of AgNPs in combination with antibiotics was confirmed against human pathogens. The highest synergistic effect (FIC = 0.0625) was demonstrated by the combination of AgNPs with streptomycin against two strains of Escherichia coli (ATCC 25922 and ATCC 8739), followed by Klebsiella pneumoniae and Pseudomonas aeruginosa (FIC = 0.125). Enhanced effects of AgNPs with ampicillin were also shown against Staphylococcus aureus ATCC 25923 (FIC = 0.125) and P. aeruginosa (FIC = 0.25), as well as kanamycin against S. aureus ATCC 6538 (FIC = 0.25). The crystal violet assay revealed that the lowest concentration of AgNPs (0.125 μg mL-1) reduced the development of biofilms of Listeria monocytogenes and Salmonella enterica, while the maximum resistance was shown by Salmonella infantis, its biofilm was reduced after exposure to a concentration of 512 μg mL-1. A high inhibitory effect on the activity of bacterial hydrolases was observed by the FDA assay. AgNPs at a concentration of 0.125 μg mL-1 reduced the hydrolytic activity of all biofilms formed by the tested pathogens, except E. coli ATCC 25922, P. aeruginosa, and Pectobacterium carotovorum (efficient concentration was 2-fold higher, at 0.25 μg mL-1), while the hydrolytic activity of E. coli ATCC 8739, Salmonella infantis and S. aureus ATCC 6538 was suppressed after treatment with AgNPs at concentrations of 0.5, 2 and 8 μg mL-1, respectively. Moreover, AgNPs inhibited fungal growth and spore germination of Botrytis cinerea, Phoma lingam, and Sclerotinia sclerotiorum. MIC and MFC values of AgNPs against spores of these fungal strains were determined at 64, 256, and 32 μg mL-1, and zones of growth inhibition were 4.93, 9.54, and 3.41 mm, respectively. Fusarium culmorum strain JTW1 was found to be an eco-friendly biological system for an easy, efficient and inexpensive synthesis of AgNPs. In our study, the mycosynthesised AgNPs demonstrated remarkable antimicrobial (antibacterial and antifungal) and antibiofilm activities against a wide range of human and plant pathogenic bacteria and fungi singly and in combination with antibiotics. These AgNPs could be applied in medicine, agriculture, and food industry to control such pathogens that cause numerous human diseases and crop losses. However, before using them extensive animal studies are required to evaluate the toxicity, if any.

Fourier Transform Infrared (FTIR) Spectroscopic Study of Biofilms Formed by the Rhizobacterium Azospirillum baldaniorum Sp245: Aspects of Methodology and Matrix Composition

Biofilms represent the main mode of existence of bacteria and play very significant roles in many industrial, medical and agricultural fields. Analysis of biofilms is a challenging task owing to their sophisticated composition, heterogeneity and variability. In this study, biofilms formed by the rhizobacterium Azospirillum baldaniorum (strain Sp245), isolated biofilm matrix and its macrocomponents have for the first time been studied in detail, using Fourier transform infrared (FTIR) spectroscopy, with a special emphasis on the methodology. The accompanying novel data of comparative chemical analyses of the biofilm matrix, its fractions and lipopolysaccharide isolated from the outer membrane of the cells of this strain, as well as their electrophoretic analyses (SDS-PAGE) have been found to be in good agreement with the FTIR spectroscopic results.

Phosphorylation modification of tilapia skin gelatin hydrolysate and identification and characterization of calcium-binding peptides

In present study, complex protease was utilized to prepare tilapia skin gelatin hydrolysate (TSGH), and the phosphorylation conditions of TSGH were optimized using calcium-binding capacity. The phosphorylation degree of TSGH under the optimal conditions was 0.55%. The calcium-binding capacities of TSGH and phosphorylated TSGH were 44.21 and 62.87 µg/mg, respectively. Phosphorylation remarkably improved the calcium-binding capacity of TSGH. Forty-four peptides and 14 phosphopeptides were identified in phosphorylated TSGH, and SGPAGPK and its phosphopeptide, (p)SGPAGPK, were screened. The calcium chelates of SGPAGPK and (p)SGPAGPK were examined using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and mass spectrometry (MS). Phosphorylation of SGPAGPK effectively increased its calcium-binding capacity. SEM results indicated that SGPAGPK-Ca and (p)SGPAGPK-Ca were formed as new compounds. FTIR and MS results indicated that the carboxyl and phosphate groups of Ser and the amino group of Lys may be the calcium chelation sites.

Experimental Study on Mechanism, Aging and Fatigue Performance of Warm Mixing Speed Melting SBS Modified Asphalt Binders

In this study, two kinds of quick melting modifier SBS-T and SBS-W, as well as the traditional SBS modifier, were used in the optimization design of asphalt binders. The changes in material structure and fatigue properties of three polymer-modified asphalt after adding 3% Sasobit to warm mix agent were investigated. The feasibility of SBS-T and SBS-W in asphalt binder was discussed from the modification mechanism and fatigue properties. In order to reveal the modification mechanism, the interaction mechanism between the fast-melting SBS modifier and the base asphalt was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The temperature sensitivity and viscoelastic properties of SBS-T and SBS-W modified binders were determined by frequency scanning (FS). The fatigue properties of SBS-T and SBS-W modified binders were tested by linear amplitude scanning (LAS). The results of FTIR showed that there was no chemical reaction between the SBS-T and SBS-W and the base asphalt. XRD results showed that SBS-W-modified asphalt has stronger fluidity. The results of FS and LAS showed that the asphalt binder with Sasobit has good stiffness and elastic recovery ability, and the same SBS-T and SBS-W have better temperature sensitivity and deformation resistance. In addition, the fatigue life of asphalt binder under the linear viscoelastic continuous damage theory is increased 3.9 times by SBS-W.

Effect of Alkaline Pretreatment on the Fuel Properties of Torrefied Biomass from Rice Husk

Lignocellulosic biomass from rice husk (RH) is a renewable resource for fuel production, but it could pose ash-related challenges. This work focused on investigating the effects of pretreatment at different sodium hydroxide (NaOH) concentrations (i.e., 0.0, 0.25, 0.50, 0.75 and 1.00 M) on the calorific values and ash contents of treated RH products, and also finding the optimal torrefaction conditions. The results showed that alkaline pretreatment by sodium hydroxide (NaOH) reduced the ash content in the RH samples by over 85 wt%. Due to its relatively excellent calorific values and low ash content, the RH sample with 0.25 M NaOH pretreatment (i.e., RH-25) was chosen as a starting feedstock in the subsequent torrefaction experiments as a function of 240–360 °C for holding time of 0–90 min. In addition, the surface properties by scanning electron microscopy—energy dispersive X-ray spectroscopy (SEM-EDS) and Fourier-transform infrared spectroscopy (FTIR) were also used to observe the elemental compositions preliminarily. Based on the fuel properties of the torrefied RH products, the optimal torrefaction conditions can be found at around 280 °C for holding 30 min. As compared to the calorific value of the RH-25 (i.e., 18.74 MJ/kg) and its mass yield (i.e., 0.588), the calorific value, enhancement factor and energy yield of the optimal product were 28.97 MJ/kg, 1.55 and 0.91, respectively. Although the resulting product has a high calorific value like coal, it could have slight potential for slagging and fouling tendency and particulate matter emissions due to the relatively high contents of silicon (Si) and sodium (Na), based on the results of EDS and FTIR.

New insight into the role of the emulsified diesel droplet size in low rank coal flotation

Low-rank coal (LRC) is difficult to float using oily collectors due to poor floatability resulted from its abundant oxygen-containing groups. In recent years, numbers of emulsified collectors have been used to enhance LRC flotation. In this study, diesel-Span80 mixed collectors were added to high shear disperser producing emulsified diesel (ED) with a droplet size ranging from 12.51 to 4.58 µm to discuss the effects of droplets size on LRC flotation. The adsorption and spreading of ED on coal particle surfaces was evaluated by total organic carbon analyzer (TOC) and fourier-transform infrared spectroscopy (FTIR). The interaction between the oil droplets and coal particles was conducted using adhesion force measurement system. The flotation results indicated clean product obtained by using ED as the collector had the higher combustible recovery and lower ash content than conventional diesel (CD). It was interesting to find an optimal droplet size (7.68 μm) at which the ED flotation performance was maximized and beyond which the flotation performance deteriorated. The FTIR, adsorption amount and adhesion force results were all well consistent with the flotation results. The effect of ED droplet size on LRC flotation is controlled by ED dispersibility and concentration of adsorbed surfactant molecules on each ED droplet surface, playing a critical role in determining the optimal droplet size which delivers the largest hydrophobicity, maximum adsorption amount, highest maximum adhesion force and hence the best flotation performance.

Effects of Curing Conditions on the Self-Healing of Geopolymer Paste

Geopolymers are inorganic polymers produced by the reaction of aluminosilicates and alkaline solutions and show good mechanical and thermal features with a huge potential for use in the construction industry. Furthermore, geopolymers with self-healing properties can considerably decrease repair or maintenance costs and support economic and environmental sustainability. This study aimed to observe the self-healing capability of sodium silicate-containing agents in geopolymer pastes. Polyethylene glycol (PEG) and epoxy resin were used to encapsulate sodium silicate. The prepared healing agent was introduced into fly ash and metakaolin-based geopolymer samples. After curing for 28 days under room conditions, the samples were subjected to compressive loading to introduce cracks. The cracked samples were stored under three conditions: at 60°C under 100% relative humidity (RH), at room temperature under 100% RH, and at room temperature in water. After various durations, optical images were captured using a light microscope to determine the closure of the cracks. X-ray diffraction (XRD) and Fourier-transform infrared spectroscopy (FT-IR) were used to identify healing products. Additionally, the change in compressive strength was used as an indicator of self-healing. The results showed that the sodium silicate agents could heal the cracks with narrow widths (<15μm) under all conditions and supported strength recovery. XRD and FT-IR results indicated that the main healing materials were aluminosilicate phases.

Synthesis and analysis of nanostructured graphene oxide

Work has been carried out to improve the method for obtaining and further oxidizing Graphene Oxide (GO) to obtain functionalized layers with a large number of active centres. We have determined that with an increase in the amount of H2O2 in the synthesis, it significantly increases the efficiency of the oxidation process and increases the number of functional groups, while the amount of NaNO3 and KMnO4 remains unchanged. Fourier-Transform Infrared Spectroscopy (FTIR), X-ray analysis, Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) analyses were carried out. Based on the FTIR result, all putative functional groups for a given material (GO) were determined, such as carbonyl, hydroxyl, ketone and epoxy groups which chemically bonded with graphene. SEM and TEM drawings were analysed, which gave a broad understanding of the morphology of GO nanostructures and, based on these drawings, it is fashionable to say that the material is semi-crystalline with the presence of such byproducts as amorphous carbon nanoparticles. Based on the EDX analysis, it was proved that this nano-structured material does not have third-party products.

Preparation, thermal storage properties and application of sodium acetate trihydrate/expanded graphite composite phase change materials.

The development of energy storage technology is beneficial for the efficient use of energy and sustainable development. As an effectual approach for storing and transporting thermal energy, latent heat storage using phase change materials (PCMs) has attracted tremendous attention. However, low thermal conductivity, poor stability, and leakages are considerable challenges to the widespread application of solid-liquid PCMs. Composite phase change materials (CPCMs) were prepared by combining expanded graphite (EG) and sodium acetate trihydrate (CH3COONa·3H2O, SAT). EG as a supporting material plays a crucial part in both enhancing the thermal conductivity and preventing the melted PCMs from leakage. The chemical structure, micromorphology, thermal stability, thermal conductivity, phase change behavior and heat storage performance of SAT/EG CPCMs have been extensively investigated by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermal conductivity analysis, differential scanning calorimetry (DSC), and cycling stability measurement. The results of SEM indicate that EG with a loose and porous layered structure has a good molding effect and can adsorb SAT well. XRD and FTIR results show that only a simple physical combination between EG and SAT exists, and no new substances have been produced. Compared with pure SAT, thermal conductivity and supercooling tests show that the supercooling degree of the CPCMs was decreased and the thermal conductivity was increased by 205.1%. In addition, the addition of 2 wt% of disodium hydrogen phosphate dodecahydrate (Na2HPO4·12H2O, DHPD) as a nucleating agent and 0.5 wt% of gelatin as a thickening agent to SAT could reduce the supercooling degree and inhibit the phase separation well. Based on SAT/EG-8% CPCMs, an oven with phase change energy storage was designed and the heat storage/release performance of the oven was investigated under different operating conditions.

Physically crosslinked polyvinyl alcohol/chitosan/gum tragacanth hydrogels loaded with vitamin E for wound healing applications

AbstractFor the healing process, in this study, an innovative polymeric hydrogel network including polyvinyl alcohol (PVA)/chitosan (CS)/gum tragacanth (GT) loaded with vitamin E (VE) was produced by the freeze–thaw approach. In order to investigate the characteristics of the prepared samples, Fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM) analyzes were performed. Also, water vapor transmission rate (WVTR), swelling ratio, gel fraction and mechanical properties were measured. Then, to observe their cytocompatibility, MTT assay and cell adhesion studies were assessed. The results of FTIR confirmed the presence of PVA, CS, GT, and VE in hydrogel films. As well as, the SEM images showed the effect of the freezing and thawing method in creating a smooth surface with small and regular pores. It was found with adding the CS and GT to PVA improves swelling ratio, gel fraction, WVTR and elongation of hydrogel films. Further, in examining the adhesion and cytotoxicity of the samples, the non‐toxic quiddity of the PVA/CS/GT hydrogel films was corroborated. In the end, the antibacterial properties revealed that the film containing GT and CS had the greatest antibacterial activity. According to the observed results, PVA/CS/GT hydrogel films loaded with VE can be good for wound healing applications.

A new iron supplement: The chelate of pig skin collagen peptide and Fe2+ can treat iron-deficiency anemia by modulating intestinal flora.

Iron deficiency anemia (IDA) is one of the most common nutritional diseases encountered all over the world. Nowadays, oral iron supplementation is still the mainstay of IDA treatment. In this study, a new iron nutritional supplement named pig skin collagen peptides ferrous chelates (PSCP-Fe) was prepared, and its structure was characterized by the scanning electron microscopy, sykam amino acid analyzer and Fourier transform infrared spectroscopy (FTIR). The anti-IDA activity of PSCP-Fe was evaluated in low-Fe2+ diet-induced IDA in rats. 16S amplicon sequencing technology was then used to reveal the mechanism of PSCP-Fe against IDA. The results of amino acid analysis and FTIR showed that aspartic acid (Asp), arginine (Arg), histidine (His), glutamic acid (Glu), cystine (Cys), and lysine (Lys) residued in PSCP chelated readily with Fe2+ through their functional groups. PSCP-Fe treated reversed the hematology-related indexes, such as red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentrate (MCHC), serum ferritin (SF), serum hepcidin (HEPC) and serum transferrin receptor (TFR). And its regulatory action was better than that of FeSO4. Moreover, PSCP-Fe alleviated the hepatocyte apoptosis and necrosis, Fe2+ loss, and injury in IDA rats. In addition, PSCP-Fe could significantly retrace the disturbed profile of gut microbiota in IDA rats (p < 0.05) and significantly up-regulated the relative abundances of nine bacterial genus, including Lactobacillus, Alloprevotella, unclassified_of_Oscillospiraceae, and NK4A214_group (p < 0.05). It could also downgrade the relative abundances of Subdoligranulum and Coriobacteriaceae_UCG-002 (p < 0.05). The results of Spearman's correlation analysis and distance-based redundancy analysis (db-RDA) revealed that Subdoligranulum and Christensenellaceae_R-7_group may be potential microbial markers for effective PSCP-Fe action in the treatment of IDA. Overall, our results elucidate the interactions between gut bacteria and related cytokines and reveal the mechanisms underlying the anti-IDA effect of PSCP-Fe. They will thus provide a theoretical foundation for PSCP-Fe as a new iron nutritional supplement.

Ultrasound-assisted reverse micelle extraction and characterization of tea protein from tea residue.

In this study, ultrasonic-assisted reverse micelles were used to extract tea protein from tea residues. First, the extraction conditions of ultrasonic power, ionic strength and pH were optimized by response surface methodology. Then, structural comparison of ultrasonic-assisted reverse micelle extraction of tea protein (UARME) and ultrasonic-assisted alkali extraction (UAAE) were performed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and amino acid composition. The optimum process conditions were determined as follows: ultrasonic power 300 W, KCl 0.15 mol L-1 , pH 8. The extraction rate was 46.29%, which was close to the theoretical value (46.44%). SEM showed that the protein particles extracted by UARME were smaller than those by UAAE. The results of FTIR spectroscopy showed that the protein extracted by UARME had higher α-helix, β-sheet and β-turn, and the contents were 20%, 62.3% and 17.1%, respectively. The content of random coil was 0%, which was significantly lower than that of alkali extraction, indicating that the secondary structure of protein extracted by UARME was more orderly. By comparing the amino acid composition of the two methods, the amino acid content of tea protein extracted by UARME was significantly higher than that of UAAE. The biological activity of tea protein is closely related to its structure. Compared with alkali extraction, reverse micelles can better protect the secondary structure of proteins, which is of great significance for studying their functional properties. © 2022 Society of Chemical Industry.

Development and Characterization of Zinc Glutarate (ZNGA) and Double Metal Cyanide (DMC) Catalyst for Bio-Based Polycarbonate Application

Heterogeneous metal complex catalyst such as Zinc glutarate (ZnGA) and Zinc-Ferum Double Metal Cyanide (Zn-Fe DMC) have been shown to improve reactivity for alternating copolymerization using CO2 and epoxides. However, there are not lot of studies that have been done to study the effect of different parameter such as time and temperature on the catalytic activities of ZnGA and Zn-Fe DMC. ZnGA was treated with toluene while Zn-Fe DMC catalyst was treated with (complexing agent) tert-butanol. The main focus of this study is to synthesize ZnGA and Zn-Fe DMC at different parameter where the catalysts were produced at a variety of temperatures (50,60,70 °C) and reaction times (3h &amp; 9h). Three different zinc-ferum ratios (1:4, 1:6, and 1:8) were developed for the Zn-Fe DMC catalyst to compare the effect of iron as metal and zinc on the active site. The catalyst was characterized using Fourier-transform infrared spectroscopy (FTIR) to determine their functional elements and Brunauer–Emmett–Teller analysis (BET) for surface characterization and pore size. The effects of reaction parameters such as time and reaction temperature were investigated using this catalyst in an auxiliary-batch reactor. FTIR result shows that GA was successful incorporation into ZnO and the production of ZnGA catalysts. The presence of typical functional groups in the Zn–Fe DMC catalysts was also confirmed. The surface area and pore volume of ZnGA increases as the temperature and reaction time increases while Zn-Fe DMC the surface area and pore volume decrease as the ratio increases. These surface-modified catalysts can generate high-molecular-weight polymers, which benefits both the environment and industry.

Photo-Assisted Catalytic CO2 Hydrogenation to CO with Nearly 100% Selectivity over Rh/TiO2 Catalysts

Photo-assisted catalytic CO2 hydrogenation represents a promising route to convert CO2 into value-added chemicals under mild conditions, but challenges remain in the design and development of highly active and selective catalysts. Herein, we synthesized highly efficient catalysts comprising Rh nanoparticles supported on TiO2 nanosheets for photo-assisted catalytic CO2 hydrogenation, which achieved a high CO production rate of 20.6 mmol gcat–1 h–1 (5.15 mol gRh–1 h–1) with nearly 100 % selectivity and excellent stability at 250 °C under light irradiation, outperforming most reported metal-based catalysts. X-ray photoelectron spectroscopy revealed that the electrons transfer from Rh nanoparticles to TiO2, hinting a strong interaction between Rh and the TiO2 support. Under illumination, the accumulated hot electrons on TiO2 surfaces could effectively promote the activation of CO2 molecules. In situ diffuse reflectance infrared Fourier transform spectroscopy results revealed that formate was the critical intermediate in the reverse water–gas shift reaction process, and light irradiation could effectively facilitate the activation and conversion of reactants and intermediate species, thereby improving CO production. This work provides a new strategy for the integration of solar and thermal energy for an efficient RWGS reaction under mild conditions.

Analysis of the effect of heating rate on pyrolysis kinetics and product composition of copper-containing waste circuit boards.

Pyrolysis is a cost-effective and environmentally benign method for recycling organic waste, which can be converted into high-energy gases and oils. Pyrolysis technology was employed in this study to recycle copper-containing discarded circuit board material and recover copper, glass fibers, and gases and oils with high calorific values. Thermogravimetric analyses (TGA), Fourier transform infrared spectroscopy (FTIR), and gas chromatography-mass spectrometry (GC-MS) were used to evaluate pyrolyses of copper-containing waste circuit board materials conducted at different heating rates (5, 10, 20, and 40°C/min), and the resulting volatiles were studied in detail. The effects of heating rate on the kinetics and activation energies for pyrolyses of copper-containing waste circuit boards were also investigated by using the Coats-Redfern (C-R) method. The TGA curves and FTIR spectra did not differ significantly for different heating rates, and the main functional groups identified with the FTIR results were O-H, C = C, aromatic benzene, substituted benzene, and C-Br. Additionally, GC-MS analyses showed that the heating rate had a great influence on the pyrolysis products formed; the phenol content decreased with increasing heating rate, and the highest content was realized at 5 ℃/min. Energy dispersive spectroscopy (EDS) analyses showed that bromine was removed from the solid phase products during pyrolysis, while copper was effectively enriched in the feedstock. This indicated that pyrolysis can be used to recover copper-containing waste circuit boards.