Acidic Properties Research Articles

Phytochemical characterization and quality evaluation of stirred goat milk yoghurt with added fruit and vegetable puree during storage

PurposeGoat milk yoghurt differs from cow milk yoghurt in that it has a different casein composition and content, which presents several technical challenges, including consistency with an appropriate flavor.Design/methodology/approachIn this study, the antioxidant potential and phytochemical profiling of the fruits (pineapple and papaya) and vegetable (carrot) extracts was evaluated and the effect of their purees on the quality and stability of stirred goat milk yoghurt (GMY) were investigated. The qualities of stirred GMY with carrot (CrY), pineapple (PaY) and papaya (PpY) purees were assessed against the product without puree (CY).FindingsThe carrot puree had the highest moisture, ash contents and pH value. The carrot extract had the highest DPPH radical scavenging activity, while the pineapple extract had the highest total phenolic value (1.59 µg GAE/g) and flavonoids content (0.203 µg CE/g). The scanning of all the puree extracts in GC-MS indicated that 5-hydroxymethylfurfural was a major component. The phytochemical quantification of the extracts through multiple reaction monitoring (MRM) against 16 compounds showed the presence of sinapic acid, cinnamic acid, pthalic acid, ferulic acid, 4-OH-benzoic acid, 3-OH-benzoic acid, p-coumaric acid, caffeic acid and vanillic acid in different quantities. The addition of purees and storage period had a significant (p < 0.05) effect on the moisture, pH, titratable acidity, syneresis, viscosity, color values and sensory properties of the products. In all the samples after 15 days of storage, Streptococcus thermophilus and Lactobacillus bulgaricus counts remained above the recommended level of 106CFU/g. Stirred GMY sample produced with pineapple puree showed a higher syneresis and viscosity, but the CrY sample demonstrated the highest antioxidant activity. The developed formulations remained stable with minimum changes in quality and sensory attribute during refrigerated storage for 10 days.Originality/valueThis study suggests that addition of fruit and vegetable improve the viscosity and sensory perception of the product with minimal use of synthetic flavor and preservatives.

Highly Efficient Carbonylation of Propylene Oxide into β‐Butyrolactone Catalyzed over Co‐Al Bimetallic Species

Rational designation of the catalyst for efficient atom‐economic conversion of propylene oxide (PO) and carbon monoxide (CO) into β‐butyrolactone is of current significance. By employing the O,N,O‐tridentate ligands R1,R2LH2 (1‐4), the aluminium compounds (R1,R2LAlCl)2 (R1,R2 = H,H (5), tBu,tBu (6), Cl,Cl (7), Br,Br (8)) and the derived anion‐cation pairs [H,HLAl(THF)3]+[Co(CO)4]ˉ (9) and [(R1,R2LAl)2Cl(THF)2]+[Co(CO)4]ˉ (R1,R2 = tBu,tBu (10), Cl,Cl (11), Br,Br (12)) as well as the aluminium‐cobalt bimetallic cluster compounds [(R1,R2LAl)2Cl(THF)][Co3(CO)10] (R1,R2 = tBu,tBu (13), Cl,Cl (14), Br,Br (15)) were prepared. Compounds 9‐12 efficiently catalyzed the PO carbonylation into β‐butyrolactone to achieve up 93.4‐98.9% yields while 13‐15 gained 95.2‐99.0% yields all at 25 °C and 0.1 MPa CO pressure. The Lewis acidic property of the aluminium compounds 5‐8 was investigated. The kinetic of the catalytic reaction using compound 10 was studied. The cooperatively catalytic reaction mechanism by the Co‐Al bimetallic species is proposed.

The Coloristic Properties of Biodegradable Fibers

This work aims to present the results of evaluating the coloristic properties of polylactic acid (PLA) fibers. PLA is common nowadays in much research, as it is a biodegradable plastic from renewable sources. However, little research is devoted to PLA fibers, and even less to applied research of colored fibers. The prepared color masterbatches, created using inorganic pigments, such as titanium dioxide and carbon black, were subsequently used to prepare dyed PLA fibers in mass. The fibers were drawn to the maximum drawn ratio. The properties of the pure and dyed fibers were investigated before and after accelerated light aging using Q-SUN equipment. The changes were recorded by Fourier Transform Infrared (FTIR) spectroscopy and colorimetric properties were recorded using a device spectrometer from TECHKON SpectroDens. We also evaluated thermal properties from the first heating via differential scanning calorimetry (DSC). The measurements were taken before and after the aging of the PLA fibers, in order to see the effect of aging on the supermolecular structure, excluding the influence of the preparation process and the influence of the kind of PLA. Using inorganic pigments showed sufficient color stability even after accelerated light aging, which is beneficial for using colored fibers in practice.

Kinetic modeling of methane dehydroaromatization over Mo/ZSM-5 catalysts

We propose a novel kinetic model for the methane dehydroaromatization (MDA) reaction over the Mo/ZSM-5 catalyst to express the practical behavior of the catalytic reaction. Unlike existing MDA kinetic models, we introduced a deactivation model involving carbon deposit formation to simulate the more realistic behavior of the MDA reaction. The proposed kinetic model integrated the “apparent kinetic model,” which focuses on detectable components, and the “micro-kinetic model,” which incorporates the acidic properties and active sites of the catalyst. To validate this model, we conducted fixed-bed experiments across a wide range of operating conditions, including temperature, gas velocity, and metal loading. Compared with experimental data, our model predictions exhibited a remarkable error of 5 %. Specifically, by leveraging the relationship between the deactivation behavior and carbon deposit formation, the model accurately predicted the CH4 conversion rates, component yields, and coke production throughout the reaction. This model sheds light on catalytic behavior during carbon deposit generation under diverse operating conditions, contributing to a comprehensive understanding of the MDA reaction mechanism. The developed kinetic model can be applied to estimate reactor performance across various scenarios. By providing a kinetic model that incorporates information regarding the catalytic properties of Mo/ZSM-5 and the apparent gas concentration, our study offers a potent tool for estimating practical reactor performance and advancing MDA catalyst development.

Principal Bioactive Properties of Oleanolic Acid, Its Derivatives, and Analogues

Principal Bioactive Properties of Oleanolic Acid, Its Derivatives, and Analogues

Adjuvant Properties of Caffeic Acid in Cancer Treatment

Adjuvant Properties of Caffeic Acid in Cancer Treatment

Clinical experience of outpatient treatment of bacterial skin infections in children

Data regarding the role of cutaneous microbiome in physiological and pathological conditions, pharmacological properties of fusidic acid and its clinical use for the treatment of skin infections are presented in the article. Incidence of skin infections in children treated in children’s city polyclinic No. 1 of Izhevsk city through 2019–2022 are analyzed. Outcomes of the treatment of these patients with topical fusidic acid preparations are presented. Due to high activity against typical cutaneous bacterial pathogens including MRSA strains of Staphylococcus aureus, favorable safety profile and pharmacokinetic profile when topically applied along with low resistance of the key pathogens fusidic acid preparations are the first line treatment of primary and secondary pyodermas.

Selector of Amino-Acid Scales Set.

Experimental and theoretical properties of amino acids as building blocks of peptides and proteins have been extensively researched. Each such method assigns a number to each amino acid, and one such assignment is called amino-acid scale. Their usage in bioinformatics to explain and predict behaviour of peptides and proteins is of essential value. The number of such scales is very large. There are more than a hundred scales related just to hydrophobicity. A large number of scales can be a computational burden for algorithms that try to define peptide descriptors combining several of these scales. Hence, it is of interest to construct a smaller, but still representative set of scales. Here, we present software that does this. We test it on the set of scales using a database constructed by Kawashima and collaborators and show that it is possible to significantly reduce the number of scales observed without losing much of the information. An algorithm is implemented in C#. As a result, we provide a smaller database that might be a very useful tool for the analyses and construction of new peptides. Another interesting application of this database would be to compare the artificial intelligence construction of peptides having as an input the complete Kawashima database and this reduced one. Obtaining in both cases similar results would give much credibility to the constructs of such AI algorithms.

In Situ Sulfonated Mesoporous Polydivinylbenzene as a Solid Acid Catalyzed the Condensation of Phenol and Acetone

AbstractSulfonated mesoporous polydivinylbenzene solid acid was prepared by in situ sulfonation method, and the physical chemical properties of this solid acid was characterized by XRD, BET, FT‐IR, etc. Acid density of sulfonated mesoporous polydivinylbenzene was characterized by acid base titration, and the result showed that the acid density was 1.58 mmol H+/g. The condensation of phenol and acetone was used as a probe reaction to investigate the catalytic performance of sulfonated mesoporous polydivinylbenzene as a solid acid. Results showed that the phenol conversion rate could approach theoretical conversion rate with Bisphenol‐A selectivity of 91 % at 90 °C. More importantly, sulfonated mesoporous polydivinylbenzene had good stability, and after repeated use for five times, the catalytic performance was not significantly reduced.

Recent Trends in Tailoring External Acidity in Zeolites for Catalysis.

Zeolites are crystalline aluminosilicates with well-defined microporous structures that have found several applications in catalysis. In recent years, great effort has been devoted to defining strategies aimed at tuning structural and acidity properties to improve the catalytic performance of zeolites. Depending on the zeolitic structure, the acid sites located inside the crystals catalyze reactions by exploiting the internal channel shape-selectivity. In contrast, strong acid sites located on the external surface do not offer the possibility to control the size of molecules involved in the reactions. This aspect generally leads to a loss of selectivity toward desired products and to the uncontrolled production of coke. Passivating surface acidity is a promising way to overcome deactivation issues and to enhance the catalytic performance of zeolites. This Mini-Review aims to provide, for the first time, a complete overview of the techniques employed in recent years to neutralize strong external acid sites. Both chemical and liquid vapor deposition of silicates have been widely employed to passivate the external surface acidity of zeolites. In recent years, the epitaxial growth of layers of aluminum-free zeolite, e.g., silicalite-1, over the surface of the acidic zeolite has been proposed as a new approach to neutralize strong external acid sites controlling diffusional phenomena. NH3-TPD, FT-IR, SEM-EDX, and other techniques have been used to provide information about the level of control of the external strong acidity of passivated zeolites. In this Mini-Review, both passivation treatments and characterization techniques are compared and advantages and disadvantages deeply discussed to elucidate the effect of passivation procedures on physical features and especially the catalytic behavior.

Effects of Ursolic Acid on Colorectal Cancer: A Review of Recent Evidence

Colorectal cancer is the third leading cause of cancer-related deaths, and the five-year survival rate of the metastatic disease is less than 15%. Treatment approaches include surgery, systemic chemotherapy and radiotherapy. The aggressive nature and low five-year survival rate of metastatic colorectal cancer indicate a need for new treatment options to help combat this disease. Ursolic acid is a pentacyclic triterpenoid naturally occurring in many plants, with high concentrations found in cranberries. This review summarizes evidence from the last ten years of the effects of ursolic acid on colorectal cancer. Overall, the available studies indicate that the treatment of colon cancer cells with ursolic acid results in a significant inhibition of proliferation and induction of apoptosis. In addition, the limited in vivo studies indicate a significant reduction in tumor volume and tumor angiogenesis in animal models of colorectal cancer administered ursolic acid. More in vivo animal studies are required to better understand the potential anticancer properties of ursolic acid and to form the basis for human clinical trials.

Effects of Ursolic Acid on Colorectal Cancer: A Review of Recent Evidence

Colorectal cancer is the third leading cause of cancer-related deaths, and the five-year survival rate of the metastatic disease is less than 15%. Treatment approaches include surgery, systemic chemotherapy and radiotherapy. The aggressive nature and low five-year survival rate of metastatic colorectal cancer indicate a need for new treatment options to help combat this disease. Ursolic acid is a pentacyclic triterpenoid naturally occurring in many plants, with high concentrations found in cranberries. This review summarizes evidence from the last ten years of the effects of ursolic acid on colorectal cancer. Overall, the available studies indicate that the treatment of colon cancer cells with ursolic acid results in a significant inhibition of proliferation and induction of apoptosis. In addition, the limited in vivo studies indicate a significant reduction in tumor volume and tumor angiogenesis in animal models of colorectal cancer administered ursolic acid. More in vivo animal studies are required to better understand the potential anticancer properties of ursolic acid and to form the basis for human clinical trials.

Efficient hydrodeoxygenation of lignin-derived phenolic compounds over bifunctional catalyst comprising H4PMo11VO40 coupled with Ni/C.

In the catalytic transformation of bio-oil into liquid fuels having alkanes via hydrodeoxygenation (HDO), the acid and metal sites in the catalyst are pivotal for promoting the HDO of lignin-derived phenolic compounds. This study introduces a novel bifunctional catalyst comprising phosphomolybdenum-vanadium heteropolyacids (H4PMo11VO40) coupled with Ni/C. The HDO reaction of the model compound guaiacol was carried out under reaction conditions of 230 °C, revealing the superior performance of H4PMo11VO40 with Ni/C catalysts compared to the conventional acids, even at low dosage. The Keggin structure of H4PMo11VO40 provided a solid catalyst with strong acidic and redox properties, alongside advantages such as ease of synthesis, cost-effectiveness, and tunable acid and redox properties at the molecular level. Characterization of Ni/C and the prepared acid demonstrated favorable pore structure with a mesopore volume of 0.281 cm3/g and an average pore size of 3.404 nm, facilitating uniform distribution and catalytic activity of Ni-metal. Incorporating acid enhances the acidic sites, fostering synergistic interactions between metal and acidic sites within the catalyst, thereby significantly enhancing HDO performance. Guaiacol conversion at 230 °C reached 100%, with a cyclohexane selectivity of 89.3%.This study presents a promising pathway for convertinglignin-derived phenolic compounds.

Effect of the reorganization of acid sites induced by metal species on TiO2 supports on the conversion of furfural to acetals and ethers

For the catalytic hydrogenation of furfural (FFR) over supported metal catalysts, acetals and ethers were often observed as by-products when alcohols were used as solvents. The presence of specific acid sites on the catalyst led to the conversion of FFR to acetals and ethers. To understand the effect of the interaction between metal species and oxide supports on the acid properties of catalysts and the conversion of FFR to acetals and ethers, anatase TiO2 (TiO2-A), rutile TiO2 (TiO2-R) and these TiO2 supported Ni catalysts were studied as models. The relationship between the acid properties of these samples and FFR conversion pathways in isopropanol was revealed. The interaction between Ni species and TiO2 supports was found to selectively remove Brønsted acid sites on the TiO2 supports in the absence of H2, thereby inhibiting the conversion of FFR to acetals and ethers in N2. However, the presence of high-pressure H2 during the reaction induced the formation of new Brønsted acid sites on Ni/TiO2 catalysts via hydrogen spillover, promoting the acetalization of FFR to acetals and the hydrogenolysis of acetals to ethers. The Ni/TiO2-A catalyst exhibited higher activity in catalyzing the conversion of FFR to acetals and ethers compared to the Ni/TiO2-R catalyst. This work provides reference information for the selective regulation of acid-catalyzed reaction pathways of FFR in alcohols.

Seaweed-based biostimulants improves quality traits, postharvest disorders, and antioxidant properties of sweet cherry fruit and in response to gibberellic acid treatment

The main aim of this research was to determine whether seaweed-based biostimulants (BIO) have the potential to offset the delaying of fruit maturation and improve fruit quality and antioxidant properties in gibberellic acid (GA3)-treated cherries. Compared to the control, 5 g L−1 BIO applied twice at pit hardening (PH) and straw color (SC) or 3 times at PH, SC, and 1 week before harvest (1WBH) in mid-maturing ‘Bing’ cherries accelerated color development, increased soluble solids content (SSC), titratable acidity, total phenolics (TP), and DPPH radical scavenging activity at harvest. However, these treatments resulted in smaller and softer fruit. For late-maturing ‘Lapins’ cherries, BIO had no effect on fruit coloration, but increased the levels of antioxidants and antioxidant capacity at harvest, especially in 3 applications. Spraying 5 g L−1 BIO 3 times plus a single application of 10 mg L−1 GA3 at PH on ‘Bing’ cherries effectively increased fruit firmness (FF) and size, but showed a strong delaying effect on color development and SSC at harvest, and reduced resistance to disorders after 4 weeks of storage at 0°C if the combination-treated fruit were late harvested. Decreasing GA3 concentration from 10 to 5 mg L−1, increasing BIO concentration from 5 to 10 g L−1, and extending the harvest date by 5 d could impair the delaying effect of GA3 on fruit maturation, restore the normal fruit size, reduce the rates of decay, stem browning (SB), and surface pitting (SP), and maintain high FF and DPPH radical scavenging activity. In conclusion, pre-harvest 3 applications of 10 g L−1 BIO and 5 mg L−1 GA3 once at PH have the potential to curtail the GA3’s inhibition on fruit maturation, extend the harvest window, improve fruit quality, and increase antioxidants and antioxidant capacity in ‘Bing’ cherries.

Nanosized “rice ball” like hierarchical beta zeolites with inter-crystalline mesopores for efficient catalytic synthesis of lactide

A series of nanosized “rice ball” like hierarchical beta zeolite aggregates (RBZxAy, x = 6, 9, 12 or 15; y = 2, 4 or 6) with hierarchical structures are successfully synthesized via gel aging and hydrothermal method without mesoporous template. The as-prepared RBZxAy zeolites possess two ranges of inter-crystalline mesoporous that formed by zeolite nanoparticles aggregation compared to the non-aged samples (B12Z4). The effects of Si/Al ratio and crystallization time on the morphology, structure and surface acidic properties of RBZxAy were systematically investigated. Meanwhile, RBZxAy as catalysts were applied in the conversion of lactic acid (LA) to lactide (LT) to investigate their catalytic performance. Benefitting from smaller crystal size, hierarchical structures and higher acid content, the representative catalyst (RBZ12A4) exhibited outstanding catalytic activity that the LA conversion was high to 98 % and the LT yield up to 94 %. In addition, RBZ12A4 presented perfect regeneration ability after 10 times recycles. This work provides an effective and facile route to directly synthesis nanocrystals aluminosilicate zeolite with hierarchal structure, and constructs an approach for efficiently converting LA to LT, it has greatly significance for the development of polylactic acid industry.

Nanosized “rice ball” like hierarchical beta zeolites with inter-crystalline mesopores for efficient catalytic synthesis of lactide

A series of nanosized “rice ball” like hierarchical beta zeolite aggregates (RBZxAy, x = 6, 9, 12 or 15; y = 2, 4 or 6) with hierarchical structures are successfully synthesized via gel aging and hydrothermal method without mesoporous template. The as-prepared RBZxAy zeolites possess two ranges of inter-crystalline mesoporous that formed by zeolite nanoparticles aggregation compared to the non-aged samples (B12Z4). The effects of Si/Al ratio and crystallization time on the morphology, structure and surface acidic properties of RBZxAy were systematically investigated. Meanwhile, RBZxAy as catalysts were applied in the conversion of lactic acid (LA) to lactide (LT) to investigate their catalytic performance. Benefitting from smaller crystal size, hierarchical structures and higher acid content, the representative catalyst (RBZ12A4) exhibited outstanding catalytic activity that the LA conversion was high to 98 % and the LT yield up to 94 %. In addition, RBZ12A4 presented perfect regeneration ability after 10 times recycles. This work provides an effective and facile route to directly synthesis nanocrystals aluminosilicate zeolite with hierarchal structure, and constructs an approach for efficiently converting LA to LT, it has greatly significance for the development of polylactic acid industry.

Characterization of a Novel Pathogenic PLCG2 Variant Leading to APLAID Syndrome Responsive to a TNF inhibitor.

Autoinflammation and PLCγ2-associated antibody deficiency and immune dysregulation (APLAID) syndrome is an autoinflammatory disease caused by gain-of-function variants in PLCG2. This study investigates the pathogenic mechanism of a novel variant of PLCG2 in a patient with APLAID syndrome. Whole exome sequencing and Sanger sequencing were used to identify the pathogenic variant in the patient. Single-cell RNA sequencing, immunoblotting, luciferase assay, IP-one ELISA, calcium flux assay, quantitative PCR, and immunoprecipitation were used to define inflammatory signatures and evaluate the effects of the PLCG2 variant on protein functionality and immune signaling. We identified a novel de novo variant, PLCG2 p.D993Y, in a patient with colitis, pansinusitis, skin rash, edema, recurrent respiratory infections, B cell deficiencies, and hypogammaglobulinemia. The single-cell transcriptome revealed exacerbated inflammatory responses in the patient's PBMCs. Expression of the D993Y variant in HEK293T, COS-7, and PLCG2 knock-out THP-1 cell lines showed heightened PLCγ2 phosphorylation, elevated IP3 production and intracellular Ca2+ release, and activation of the MAPK, NFκB, and NFAT signaling pathways compared to control-transfected cells. In vitro experiments indicated that the D993Y variant altered amino acid properties, disrupting the interaction between the catalytic and auto-inhibitory domains of PLCγ2, resulting in PLCγ2 auto-activation. Our findings demonstrated that the PLCG2 D993Y variant is a gain-of-function mutation via impairing its auto-inhibition, activating multiple inflammatory signaling pathways, thus leading to APLAID syndrome. This study further broadens the molecular underpinnings and phenotypic spectrum of PLCγ2-related disorders.

Design of Cellulose Nanocrystal-Based Self-Healing Nanocomposite Hydrogels and Application in Motion Sensing and Sweat Detection.

Hydrogels, as flexible materials, have been widely used in the field of flexible sensors. Human sweat contains a variety of biomarkers that can reflect the physiological state of the human body. Therefore, it is of great practical significance and application value to realize the detection of sweat composition and combine it with human motion sensing through a hydrogel. Based on mussel-inspired chemistry, polydopamine (PDA) and gold nanoparticles (AuNPs) were coated on the surface of cellulose nanocrystals (CNCs) to obtain CNC-based nanocomposites (CNCs@PDA-Au), which could simultaneously enhance the mechanical, electrochemical, and self-healing properties of hydrogels. The CNCs@PDA-Au was composited with poly(vinyl alcohol) (PVA) hydrogel to obtain the nanocomposite hydrogel (PVA/CNCs@PDA-Au) by freeze-thaw cycles. The PVA/CNCs@PDA-Au has excellent mechanical strength (7.2 MPa) and self-healing properties (88.3%). The motion sensors designed with PVA/CNCs@PDA-Au exhibited a fast response time (122.9 ms), wide strain sensing range (0-600.0%), excellent stability, and fatigue resistance. With the unique electrochemical redox properties of uric acid, the designed hydrogel sensor successfully realized the detection of uric acid in sweat with a wide detection range (1.0-100.0 μmol/L) and low detection limit (0.42 μmol/L). In this study, the dual detection of human motion and uric acid in sweat was successfully realized by the designed PVA/CNCs@PDA-Au nanocomposite hydrogel.

Characterization of acid sites on Hf-Beta zeolite by CD3CN IR-TPD

To identify Hf species and quantitatively evaluate their acid properties, combined measurement of infrared (IR) and temperature-programmed desorption (TPD) with deuterated acetonitrile (CD3CN) as probe molecule was performed on Hf-Beta and HfO2/Si-Beta. IR spectra of CD3CN adsorbed on Hf-Beta showed five types of Hf species including framework open and closed Hf sites, extra-framework HfO2, and two types of Hf species bearing hydroxy groups. IR measurement showed structural change in Hf-Beta upon exposing to water vapor with generation of the two types of Hf species bearing hydroxy groups. Integrated molar extinction coefficients for C N stretching vibration of CD3CN adsorbed on these Hf species were estimated and the number of each Hf acid site was calculated. Acid strength of these Hf species was estimated from CD3CN-TPD measurement in combination with IR; the acid strength of the open and closed Hf sites, extra-framework HfO2 species, and the other Hf species was found to be strong, moderate, and weak, respectively.