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Protein tyrosine phosphatases (PTPs) play major roles in cancer and are emerging as therapeutic targets. Recent reports suggest low-molecular weight PTP (LMPTP)-encoded by the ACP1 gene-is overexpressed in prostate tumors. We found ACP1 up-regulated in human prostate tumors and ACP1 expression inversely correlated with overall survival. Using CRISPR-Cas9-generated LMPTP knockout C4-2B and MyC-CaP cells, we identified LMPTP as a critical promoter of prostate cancer (PCa) growth and bone metastasis. Through metabolomics, we found that LMPTP promotes PCa cell glutathione synthesis by dephosphorylating glutathione synthetase on inhibitory Tyr270. PCa cells lacking LMPTP showed reduced glutathione, enhanced activation of eukaryotic initiation factor 2-mediated stress response, and enhanced reactive oxygen species after exposure to taxane drugs. LMPTP inhibition slowed primary and bone metastatic prostate tumor growth in mice. These findings reveal a role for LMPTP as a critical promoter of PCa growth and metastasis and validate LMPTP inhibition as a therapeutic strategy for treating PCa through sensitization to oxidative stress.

High-molecular-weight linear polymers (HMWLPs) have earned the name "drag-reducing polymers" because of their ability to reduce drag in turbulent flows. Recently, these polymers have become popular in bioengineering applications. This study investigated whether the addition of HMWLP in a venoarterial extracorporeal circulation (ECC) model could improve microvascular perfusion and oxygenation. Golden Syrian hamsters were instrumented with a dorsal skinfold window chamber and subjected to ECC using a circuit comprised of a peristaltic pump and a bubble trap. The circuit was primed with lactated Ringer solution (LR) containing either 5 ppm of polyethylene glycol (PEG) with a low molecular weight of 500 kDa (PEG500k) or 5 ppm of PEG with a high molecular weight of 3,500 kDa (PEG3500k). After 90 min of ECC at 15% of the animal's cardiac output, the results showed that the addition of PEG3500k to LR improved microvascular blood flow in arterioles and venules acutely (2 h after ECC), whereas functional capillary density showed improvement up to 24 h after ECC. Similarly, PEG3500k improved venular hemoglobin O2 saturation on the following day after ECC. The serum and various excised organs all displayed reduced inflammation with the addition of PEG3500k, and several of these organs also had a reduction in markers of damage with the HMWLPs compared to LR alone. These promising results suggest that the addition of small amounts of PEG3500k can help mitigate the loss of microcirculatory function and reduce the inflammatory response from ECC procedures.NEW & NOTEWORTHY High-molecular-weight linear polymers have gained traction in bioengineering applications. The addition of PEG3500k to lactated Ringer solution (LR) improved microvascular blood flow in arterioles and venules acutely after extracorporeal circulation (ECC) in a hamster model and improved functional capillary density up to 24 h after ECC. PEG3500k improved venular hemoglobin O2 saturation and oxygen delivery acutely after ECC and reduced inflammation in various organs compared to LR alone.

The growing interest in plant-based proteins is driven by sustainability concerns and potential adverse reactions to animal protein consumption. Plant proteins, while promising, are known for their inferior digestibility compared to animal counterparts. Solid-state fermentation (SSF) offers an ancient, cost-effective approach to address this limitation. SSF enhances plant-based foods by augmenting protein content through microbial hydrolysis, thereby improving overall nutritional quality. This method not only boosts protein digestibility but also reduces larger polypeptides, generates bioactive peptides, refines amino acid profiles, and eliminates anti-nutritional factors such as trypsin inhibitors and tannins. Further investigation is essential to optimize the purification of protein isolates and examine their behaviour during digestion and absorption using in vitro, cellular, and in vivo models. In conclusion, SSF represents a promising, cost-effective, and high-yield processing method to produce nutritionally enhanced plant proteins, aligning with the demands of both the industry and consumers. [ABSTRACT FROM AUTHOR]

ABSTRACT Molecular characteristics of emulsifiers such as their molecular weight (MW) and surface charge, not only affect the stability of the emulsion but also can have an impact on its capacity to either inhibit or promote microbial proliferation. These characteristics can affect the behavior of pathogens such as Salmonella Typhimurium in emulsion systems. The growth and thermal resistance of S. Typhimurium were monitored at different oil content levels (20%, 40%, and 60%) in emulsions stabilized by three whey protein‐based emulsifiers: whey protein isolate (WPI), whey protein hydrolysate (WPH), and a modified WPI with an alteration of charge (WPI+). Our study revealed that emulsifier itself with different MW and surface charge had no effect on bacterial growth and inactivation without oil inclusion (p > 0.05). However, it was found that higher bacterial growth rate at 60% oil content emulsion stabilized with WPI+ (0.65 ± 0.03 log CFU/h) than WPI (0.19 ± 0.04 log CFU/h), which showed the charge of emulsifiers has different effects on microbial dynamics in oil‐in‐water emulsion. Interestingly, WPI+ in emulsions also seemed to convey protection against thermal inactivation of bacteria. These data describe a complex interrelationship between the physicochemical characteristics of the emulsifier and its interacting nature with bacterial cells. They throw even more light on the insight about the importance of a strategic approach toward emulsifier selection in food formulations. This is crucial for the food safety and stability of products. [ABSTRACT FROM AUTHOR]

The incorporation of semi-crystalline polymers as additives with small-molecule organic semiconductors has emerged as a pioneering method for the alteration of crystallization processes, thin film morphologies, and charge carrier mobility within organic semiconductor matrices. In this paper, we utilize the intrinsic attributes of polyethylene oxide (PEO), acting as a semi-crystalline polymer additive, to modulate the crystallization, phase segregation and charge transport of 6,13-bis (triisopropylsilyl) pentacene (TIPS pentacene). To understand the synergistic effects between varying molecular weights (8, 100, 300 and 900 K) of PEO and the crystallization behavior of TIPS pentacene, we conducted a quantitative analysis of the films' relative crystallinity and crystallographic morphology employing X-ray diffraction (XRD) and optical microscopy. Our findings indicate that higher molecular weight PEOs (300K and 900K) exhibit reduced molecular chain activity, resulting in lower crystallinity at increased doping ratios. Furthermore, attributes such as a high dielectric constant and a substantial melting point, combined with favorable thermoplastic properties, predispose these films to a more susceptible phase separation within the crystalline matrix. Conversely, films with lower molecular weight PEOs (8 and 100 K) showed lesser impact from molecular chain dynamics, leading to enhanced crystal morphology, higher crystallinity, and improved charge carrier mobility by up to 11 times. This substantial enhancement underscores the potential of employing low molecular weight semi-crystalline polymers as additive agents in the development of advanced organic semiconductor devices. [ABSTRACT FROM AUTHOR]

Lipid nanoparticles (LNPs) have been demonstrated to be potent and well‐tolerated vehicles for delivering mRNA in vaccination and therapeutics. However, the presence of anti‐poly(ethylene glycol) (PEG) antibodies in the body resulted in the problems of hypersensitivity reaction, accelerated blood clearance and high systemic reactogenicity after repeated dosing of PEG lipid‐contained LNPs, thus limiting the utility for in vivo messenger RNA (mRNA) delivery. Here, we synthesized well‐defined polysarcosine functionalized lipids (pSar‐lipids) with various hydrophobic tail lengths and molecular weights by the accelerated ring‐opening polymerization of sarcosine N‐carboxyanhydride (NCA). The obtained pSar‐lipids were utilized as PEG lipid alternatives to explore structure–activity relationships of pSar‐lipid‐based LNPs. The results demonstrated that pSar‐lipid‐based LNPs by intravenous administration represented higher mRNA delivery efficiency in the liver and spleen with the increased hydrophobic tail length of pSar‐lipids. Importantly, more significant preference for mRNA delivery into the liver was identified by increasing the molecular weight of pSar segments. As a result, this work elucidated the effect of structural variations in pSar‐lipids on LNP‐mediated in vivo mRNA delivery, providing clues to optimize pSar‐lipids as potential alternatives to PEG lipids for developing next‐generation of LNP delivery systems. [ABSTRACT FROM AUTHOR]

Bitterness is a common flavor attribute of aged cheese associated with the peptide fraction, but excessive levels are a defect leading to consumer rejection. Bitterness in cheese has been primarily associated with peptides that arise from the breakdown of casein. The last review of bitter peptides was published in 1992. This updated review compiled information about the bitter peptides published up to 2022. Our comprehensive search of the literature compiled 226 peptides associated with bitterness and cheese protein origins into a database (Supplemental Materials). The influences of a peptide's physical properties, such as molecular weight, average hydrophobicity, peptide length, number of prolines and the presence of hydrophobic amino acids in the peptide's terminus, were assessed for correlation with bitterness threshold values this assessment found that, among variables considered, higher molecular weight had the strongest correlation with higher bitterness among known peptides. Heatmaps of bitter peptides and their bitterness threshold values highlight β-casein as the primary source of known bitter peptides in cheese. This comprehensive database of cheese protein-derived bitter peptides and this discovery of the correlation of a peptide's physical properties to bitterness will aid future researchers in the identification and discovery of contributors to cheese bitterness. [ABSTRACT FROM AUTHOR]

Copyright of China Plastics / Zhongguo Suliao is the property of Journal Office of CHINA PLASTICS and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Cobaltocenium-containing (co)polysiloxanes (Cc-PDMSs) with terminal and side groups were synthesized by the reaction of catalyst-free hydroamination between ethynylcobaltocenium hexafluorophosphate and polysiloxanes comprising amino moieties as terminal and side groups. The conversion of NH2 groups in the polymers reaches 85%. The obtained (co)polysiloxanes "gelate" due to an increase in their molecular weight by approx. 30 times, when stored at room temperature over one week. "Gelated" Cc-PDMSs remain soluble in most polar solvents. The structure of Cc-PDMSs and the mechanism of "gelation" were established by 1H, 13C{1H}, 29Si{1H}, 19F{1H}, 31P{1H} nuclear magnetic resonance, infrared, ultraviolet–visible, and X-ray photoelectron spectroscopies. As determined by cyclic voltammetry, Cc-PDMSs possess redox properties (CoII/CoIII transitions at E1/2 = −1.8 and −1.3 V before and after "gelation", respectively). This synthetic approach allows to increase the molecular weights of the synthesized polysiloxanes functionalized with cobaltocenium groups easily, leading to their higher film-forming ability, which is desirable for some electronic applications. Cc-PDMSs can be utilized as redox-active polymer films in modified electrodes, electrochromic devices, redox-active coatings, and components for batteries. [ABSTRACT FROM AUTHOR]

In the development of polymer electrolytes, the understanding of the complex interplay of factors that affect ion transport is of importance. In this study, the strongly coordinating and flexible poly (ethylene oxide) (PEO) is compared to the weakly coordinating and stiff poly (trimethylene carbonate) (PTMC) as opposing model systems. The effect of molecular weight (Mn) and end group chemistry on the physical properties: glass transition temperature (Tg) and viscosity (η) and ion transport properties: transference number (T+), ion coordination strength and ionic conductivities were investigated. The cation transference number (T+) showed the opposite dependence on Mn for PEO and PTMC, decreasing at low Mn for PTMC and increasing for PEO. This was shown to be highly dependent on the ion coordination strength of the system regardless of whether the end group was OH or if the chains were end‐capped. Although the coordination is mainly of the cations in the systems, the differences in T+ were due to differences in anion rather than cation conductivity, with a similar Li+ conductivity across the polymer series when accounting for the differences in segmental mobility. [ABSTRACT FROM AUTHOR]

Supramolecular polymers, as a type of dynamic polymers, are subordinate to the interdisciplinary field of polymer chemistry and supramolecular chemistry, whose development has greatly promoted the prosperity of new materials. Notably, molecular weight is one of the most important parameters of supramolecular polymers, which affects the physical/chemical properties and processing applications of materials. Developing new methods for characterizing the molecular weight of supramolecular polymers is crucial for advancing the development of supramolecular polymers. In this review, we elaborate and summarize three strategies for characterizing the molecular weight of supramolecular polymers that recently reported by our research group according to the characteristics of supramolecular polymers, including (1) the molecular weight distinction corresponding to variable fluorescence colors, (2) matching different molecular weights with different fluorescence lifetime, (3) transforming supramolecular polymers into mechanically interlocked polymers or covalent polymers. Besides, we also discuss the limitations of current methods for characterizing supramolecular polymers. We hope that this review can promote the development of supramolecular polymers and significantly inspire to exploit new methods to characterizing molecular weight of supramolecular polymers. [ABSTRACT FROM AUTHOR]

Introduction: Dry eye disease (DED) is one of the most prevalent eye conditions worldwide, with artificial tears serving as a primary treatment option. Despite their wide availability on the European market, there is a lack of established classifications based on their physicochemical properties. The aim of our study was therefore (i) to develop an analytical method that measures the concentration and the molecular weight (MW) of the hyaluronic acid (HA) in commercialized products, and (ii) to propose an overview based on their various physicochemical parameters. Methods: The intrinsic viscosity and MW of the HA, as well as osmolarity, pH, rheological profile, and viscosity, were measured or determined. A specific method was developed to measure the average intrinsic viscosity and HA content using a liquid size-exclusion chromatography system. The MW was determined using the Mark–Houwink equation. Results: Thirty-seven products commercialized in Europe were analyzed, with 21 of them containing HA. The HA MW was lowest (300 kDa) for Thealose®, Thealoz Duo® Gel, and Hyabak®, and highest (1300 kDa) for Vismed® Multi, Vismed® Gel, and Neovis® Gel. The pH values varied between 5.94 for Treovis® and 8.06 for Systane® Ultra. Osmolarity ranged between 148 mOsm/L and 325 mOsm/L for Neovis® and Treovis®, respectively. Viscosity was highly variable, ranging from 0.38 mPas·s for Hylolipid® to 337.47 mPas·s for Thealoz® Duo Gel. Finally, rheological profile analysis revealed different shear-thinning behaviors. Conclusion: While the perfect eye drop does not exist, a multitude of options are available to choose from. This study improves our understanding of the major tear substitutes available on the European market based on several physicochemical properties. A better understanding and awareness of these parameters is crucial in order to offer the best treatment for patients with DED. [ABSTRACT FROM AUTHOR]

Background/Objectives: Excessive reactive oxygen species (ROS) can lead to oxidative stress, which has become an urgent problem requiring effective solutions. Due to the drawbacks of chemically synthesized antioxidants, there is a growing interest in natural antioxidants, particularly antioxidant peptides. Methods: By reviewing recent literature on antioxidant peptides, particularly those extracted from various parts of fish, summarize which fish by-products are more conducive to the extraction of antioxidant peptides and elaborate on their characteristics. Results: This article summarizes recent advancements in extracting antioxidant peptides from fish processing by-products, Briefly introduced the purification and identification process of antioxidant peptides, specifically focusing on the extraction of antioxidant peptides from various fish by-products. Additionally, this article comprehensively reviews the relationship between amino acid residues that compose antioxidant peptides and their potential mechanisms of action. It explores the impact of amino acid types, molecular weight, and structure–activity relationships on antioxidant efficacy. Conclusions: Different amino acid residues can contribute to the antioxidant activity of peptides by scavenging free radicals, chelating metal ions, and modulating enzyme activities. The smaller the molecular weight of the antioxidant peptide, the stronger its antioxidant activity. Additionally, the antioxidant activity of peptides is influenced by specific amino acids located at the C-terminus and N-terminus positions. Simultaneously, this review provides a more systematic analysis and a broader perspective based on existing research, concluded that fish viscera are more favorable for the extraction of antioxidant peptides, providing new insights for the practical application of fish by-products. This could increase the utilization of fish viscera and reduce the environmental pollution caused by their waste, offering valuable references for the study and application of antioxidant peptides from fish by-products. [ABSTRACT FROM AUTHOR]

Membrane fouling caused by effluent organic matter (EfOM) limits its further application in wastewater reuse. In this study, the effect of UV/chlorine pretreatment on membrane fouling was investigated in treating secondary effluent by ultrafiltration (UF) process. The relation between organic matter changes and fouling alleviation after UV/chlorine pretreatment was also studied according to the molecular weight (MW) changes in various resin fractions derived from EfOM. Results showed that UV/chlorine pretreatment effectively alleviated irreversible fouling, whereas chlorine pre-oxidation primarily mitigated reversible fouling. UV/chlorine pre-oxidation reduced 18% of reversible membrane fouling and 38% of irreversible membrane fouling at a chlorine dosage of 8 mg/L, indicating better performance in membrane fouling mitigation than chlorine pre-oxidation. UV/chlorine pre-oxidation also decreased dissolved organic matter in the UF permeate. The hydrophobic acidic (HPO-A) fraction caused dominant membrane fouling, while the hydrophilic (HPI) fraction contained most of high MW organic matter. Pre-oxidation changed the polarity of organic matter in the HPO-A fraction and decomposed the organics of high MW in the HPI fraction, which alleviated membrane fouling. These results showed that UV/chlorine pre-oxidation was a prospective pretreatment process prior to UF in wastewater reclamation. [ABSTRACT FROM AUTHOR]

The aim of this study was to characterize and evaluate the antioxidant activity of Chlorella peptide fractions coated with chitosan-modified nanoliposomes. Additionally, the release process of these peptide fractions under simulated gastric and intestinal conditions was evaluated. Protein hydrolysates were obtained from Chlorella through enzymatic hydrolysis, resulting in increased concentrations of antioxidant and hydrophobic amino acids. Peptide fractions were selected and separated based on their molecular weights, and it was observed that the fractions with lower molecular weights (less than 10 kDa, PF-10) contained higher amounts of hydrophobic and antioxidant amino acids. Among the fractions, PF-10 exhibited the highest radical inhibition activity for DPPH and ABTS, as well as enhanced reducing power and chelating activity towards copper ions. PF-10 and PF-30 (peptide fractions with a molecular weight less than 30 kDa) also demonstrated higher inhibition of nitric oxide radicals and total antioxidant activity (TAA) compared to the hydrolyzed form and other fractions. The analysis of physicochemical properties identified PF-10 as the most favorable treatment due to its size, polydispersity index (PDI), zeta potential, and encapsulation efficiency (EE). Coating the nanoliposomes with chitosan resulted in an increase in particle size and PDI but significantly improved the preservation of EE during storage. Chitosan coating also enhanced the activity of DPPH and OH radical scavenging. Fourier-transform infrared spectroscopy (FTIR) confirmed the localization of peptides within the polar regions and the bilayer membrane of nanoliposomes, while scanning electron microscopy (SEM) revealed agglomerated and spherical structures. Overall, our findings highlight the effectiveness of nanoliposomes as carriers for delivering peptide fractions with high antioxidant activity. The formulation of chitosan-coated nanoliposomes as carriers for Chlorella-peptide fractions represents an innovative advancement, providing opportunities for the creation of functional and stable formulations. These formulations hold the potential to provide benefits regarding human health and environmental considerations. [ABSTRACT FROM AUTHOR]

BACKGROUND RESULTS CONCLUSION Polyphenols present in sunflower meal act on sunflower proteins by reacting directly with their structures and thus influencing their purity, solubility, crystallinity, and functionality. However, the effect on these properties of varying concentrations of ethanol used in dephenolization has yet to be explored. The present study aimed to explore the impact of dephenolization using varying ethanol concentrations (60%, 70%, 80%, and 90%) on the physicochemical, color, thermal, structural, functional, and flow behavior of protein isolates extracted from sunflower meal.Protein isolates originating from meals that were dephenolized using higher ethanol concentrations exhibited a protein content of 836.10 g kg−1. As the concentration of ethanol increased, a reduction in crystallinity was observed from 24% to 14.15%. Fourier transform infrared (FTIR) spectroscopy revealed marked shifts in major peaks within the 1600 to 1700 cm−1 wavelength range, indicating significant structural and conformational changes. Sodium dodecyl‐sulfate polyacrylamide gel electrophoresis (SDS‐PAGE) results demonstrated that dephenolization caused decline in molecular weight ranging from 25 kDa to 60 kDa. Dephenolization induced significant changes in surface morphology resulting in more heterogeneous and disordered surfaces as indicated by field emission–scanning electron microscopy (FE‐SEM) micrographs. Overall improvement in the functional properties was observed, with an increase in solubility from 15.20% to 22.03%. Improvement in the flow behavior with an increase in porosity from 38% to 60% was also observed, due to dephenolization.Dephenolization using 90% ethanol induced structural changes that enhanced physicochemical and functional characteristics of sunflower protein isolates by improving purity and solubility, reducing crystallinity, and increasing flow behavior. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

With the increasing emphasis on environmental protection, there is a growing focus on the synthesis of water‐solvent self‐emulsifying sizing agents. In this study, five types of anionic polyester sizing agents with varying molecular weights were synthesized to explore the effect of molecular weight on the interfacial bonding strength of carbon fiber (CF) reinforced vinyl resin composites. The results demonstrated that the molecular weights of the synthesized sizing agents were precise; the particles in the sizing agents were nanometer‐sized, monodisperse, and exhibited high thermal stability. When the molecular weight was 8000, it exhibited optimal wettability for CF, leading to a substantial improvement in the interlaminar shear strength, reaching 71.8 MPa, which represents a significant increase of 22.7% compared with commercial CFs (CFF). Additionally, the interfacial shear strength was maximized at 13.23 MPa, which was significantly increased by 14.2% compared with CCF. These significant improvements in surface properties and mechanical performance were attributed to the excellent wettability of the CF surface, effective spreading performance of the sizing agent, the presence of double bonds in the sizing agent facilitating reactions with free radicals on the CF surface, and the residual double bonds further undergoing curing with the vinyl resin, promoting the reinforcement of interface bonding. [ABSTRACT FROM AUTHOR]

In this study, microwave-assisted extraction of faba bean protein (BP) concentrate was optimized through the response surface methodology. Microwave power (250-500 W) and processing time (10-60 min) were chosen as independent variables and the effect of these parameters on protein yield was investigated. The highest protein yield (47.74%) was achieved at 481.70 W microwave power and 50.68 min processing time. The characteristic properties of BP obtained under optimum conditions were compared with whey protein. The characteristic bonds of the proteins were confirmed by Fourier transform infrared spectroscopy (FTIR) and molecular weights were determined by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-page). The solubility values of BP and whey protein were found to be as 80.23% and 91.12%, respectively (P <0.05). BP's foaming properties, emulsifying behavior, and stability coefficient resulted in superior to whey protein. The results showed plant proteins will be considered as alternative protein sources in food systems. [ABSTRACT FROM AUTHOR]

Objective: Hyaluronic acid (HA) has become a commonly used ingredient in topical moisturizing products; however, limitations of delivery of HA to only the surface of skin have hindered leveraging the full capacity of HA for skin rejuvenation. Here, we aimed to evaluate the clinical benefits of a multi-weight HA plus antioxidant complex-based lotion with SPF 30 compared to a single-weight HA plus ceramide-based lotion with SPF 30. Methods: A double-blind comparative study was conducted on 70 female subjects, aged 25 to 65 years with mild-to-moderate facial dryness and visible fine lines and wrinkles, divided evenly into two groups (n=35 per group). Clinical grading of the face, including dryness, roughness, and fine lines, was assessed after once-daily application for up to eight weeks. Results: Daily use of the multi-weight HA plus antioxidant lotion demonstrated significant improvements in all clinical grading assessments (dryness, roughness, and fine lines) as early as Week 2 compared to baseline. Statistically significant improvements in visible dryness, roughness, and fine lines were greater for the multi-weight HA plus antioxidant lotion compared to the single-weight HA plus ceramide-based lotion. Limitations: The overall small sample size. Conclusion: This study showed the enhanced improvement in dryness, roughness, and fine lines following daily utilization of a novel multi-weight HA plus antioxidant complex-based lotion compared to a single-weight HA plus ceramide-based lotion. These improvements may be attributed to the ability of multi-weight HAs to moisturize the skin surface and penetrate the upper surface layers of the skin, combined with the added benefits of key antioxidants. [ABSTRACT FROM AUTHOR]

Copyright of Storage & Process is the property of Tianjin Academy of Agricultural Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The conversion from line-angle formula to chemical formula often poses a challenge for first-year nonchemistry majors. To address this, the authors developed an engaging exercise lecture that encompasses the conversion process and related chemistry concepts, including molecular weight and elemental analysis. Initially, the instructor reviews basic chemistry concepts with the students. Subsequently, students construct a NanoKid structure model using transistors and red LEDs connected by plastic tubes, representing carbon and oxygen atoms, respectively. By referencing their models, students identify the chemical formula of NanoKid, calculate its molecular weight, and perform elemental analysis under the guidance of the instructor. Additionally, they estimate the scale of the NanoKid model relative to the actual NanoKid molecule. The exercise promotes peer review among students and is completed within approximately 45 min. A post-lecture questionnaire revealed that the exercise was well-received by the students. [ABSTRACT FROM AUTHOR]

M Q s i l i c o n e r e s i n i s t h e copolymerization product of tetraalkoxysilane Q unit and trimethylethoxysilane M unit. It has a special double-layer tightly crosslinked spherical network structure, which not only has excellent water resistance, thermal stability and compatibility, but also is long-lasting, safe and non-irritating. So it has become one of the indispensable filmforming ingredients in cosmetic formulations. Therefore, it is vital to evaluate and screen the MQ silicone resin for improving the efficiency of formulation development. The molecular structure and film morphology of 21 MQ silicone resins were analyzed by GPC, microscopy and air permeability analyzer. According to the results, the relationship between the molecular structure of MQ and its application properties, such as film forming time, film brittleness, air permeability, water resistance, sweat resistance and oil resistance, were explored. The results show that the properties or performance of MQ silicone resin are depended on the size and distribution of its molecular weight. For the MQ-type silicone resin filmogen with higher molecular weight and narrower distribution, its film properties of hardness, water resistance and sweat resistance are enhanced with the increase of molecular weight, but its air permeability is subsequently weakened and film forming time is shorter. When the molecular weight decreases and the polymer dispersity index is almost unchanged or broadened, the MQ silicone resin show softer film, better oil resistance, longer film-forming time and higher air permeability. [ABSTRACT FROM AUTHOR]

There are difficulties in measuring the molecular weight (Mw) of bacterial cellulose (BC) using Gel Permeation Chromatography (GPC) analysis. Additionally, the Mark-Houwink-Sakurada equation cannot be used to predict the Mw of BC as no Mark-Houwink-Sakurada constant specific to BC is available. In this study, a systematic approach is developed to establish the relationship between the Mw of BC and the viscosity of its copper (II) ethylenediamine (CED) solutions. Impurities contained in the raw BC are examined and appropriate purification procedures are designed for their removal before the above two measurements are conducted. The Mw of BC is obtained by measuring the Degree of Polymerization of its corresponding cellulose acetate (CA), derived from degraded BC, using GPC analysis, and the viscosity of the CED solutions of the BC is measured using a BS/U Tube viscometer. In this paper, the Mark–Houwink–Sakurada constants (K=0.3752 mL/g and α =1.4532) specific for BC are determined to relate the Mw of BC with the intrinsic viscosity of its CED solutions. It is also found that the Mw of BC is proportional to the dynamic viscosity (i.e., η BC = 0.0183 M w 1.3069 ) and the flow time (i.e., t BC = 1.3809 Mw 1.3062 ) of its CED solutions. These BC-specific relationships can help determine the Mw of BC from the rheological properties of its CED solutions. [ABSTRACT FROM AUTHOR]

Abstract Introduction Dry eye disease (DED) is one of the most prevalent eye conditions worldwide, with artificial tears serving as a primary treatment option. Despite their wide availability on the European market, there is a lack of established classifications based on their physicochemical properties. The aim of our study was therefore (i) to develop an analytical method that measures the concentration and the molecular weight (MW) of the hyaluronic acid (HA) in commercialized products, and (ii) to propose an overview based on their various physicochemical parameters. Methods The intrinsic viscosity and MW of the HA, as well as osmolarity, pH, rheological profile, and viscosity, were measured or determined. A specific method was developed to measure the average intrinsic viscosity and HA content using a liquid size-exclusion chromatography system. The MW was determined using the Mark–Houwink equation. Results Thirty-seven products commercialized in Europe were analyzed, with 21 of them containing HA. The HA MW was lowest (300 kDa) for Thealose®, Thealoz Duo® Gel, and Hyabak®, and highest (1300 kDa) for Vismed® Multi, Vismed® Gel, and Neovis® Gel. The pH values varied between 5.94 for Treovis® and 8.06 for Systane® Ultra. Osmolarity ranged between 148 mOsm/L and 325 mOsm/L for Neovis® and Treovis®, respectively. Viscosity was highly variable, ranging from 0.38 mPas·s for Hylolipid® to 337.47 mPas·s for Thealoz® Duo Gel. Finally, rheological profile analysis revealed different shear-thinning behaviors. Conclusion While the perfect eye drop does not exist, a multitude of options are available to choose from. This study improves our understanding of the major tear substitutes available on the European market based on several physicochemical properties. A better understanding and awareness of these parameters is crucial in order to offer the best treatment for patients with DED.

Polyethylene (PE) is the most widely produced synthetic polymer and the most abundant plastic waste worldwide due to its recalcitrance to biodegradation and low recycle rate. Microbial degradation of PE has been reported, but the underlying mechanisms are poorly understood. Here, we isolated a Rhodococcus strain A34 from 609 day enriched cultures derived from naturally weathered plastic waste and identified the potential key PE degradation enzymes. After 30 days incubation with A34, 1% weight loss was achieved. Decreased PE molecular weight, appearance of C-O and C═O on PE, palmitic acid in the culture supernatant, and pits on the PE surface were observed. Proteomics analysis identified multiple key PE oxidation and depolymerization enzymes including one multicopper oxidase, one lipase, six esterase, and a few lipid transporters. Network analysis of proteomics data demonstrated the close relationships between PE degradation and metabolisms of phenylacetate, amino acids, secondary metabolites, and tricarboxylic acid cycles. The metabolic roadmap generated here provides critical insights for optimization of plastic degradation condition and assembly of artificial microbial communities for efficient plastic degradation.

Ziziphus jujuba is a commonly used medicinal and edible plant in China. Ziziphus jujuba polysaccharide is one of the main active component of Ziziphus jujuba, and has been confirmed by pharmacological studies with a variety of biological activities. The research on the structure of Ziziphus jujuba polysaccharide is mostly focused on modification method, monosaccharide constitutes, molecular weight and glycosidic bond type. Extensive studies have shown that Ziziphus jujuba polysaccharide exert multiple biological activities, such as antioxidant, hepatoprotective, hypoglycemic, lipid-lowering, bacterial abundance regulation, immune regulation, anti-cancer and anticoagulant. Ziziphus jujuba polysaccharide can be used in anti-oxidation film, anti-aging, hypoglycemic, sugar replacement, lipid-lowering products, bacteriostatic agent, immunomodulators, anti-cancer nutrition food and other products. Based on these findings, this article summarizes and prospects, in order to provide a theoretical basis for further explore the structure of Ziziphus jujuba polysaccharides, standardize the preparation and extraction process of Ziziphus jujuba polysaccharides, clarify the biological activity mechanism of Ziziphus jujuba polysaccharides, and increase the diversity of Ziziphus jujuba polysaccharide products.

AbstractMarine bioactive peptides (MBPs) are a type of natural compound with a variety of bioactivities, such as anticancer, antimicrobial, antioxidant, and antihypertensive. Due to a wide range of sources, low toxicity, and high specificity, MBPs have now received extensive attention in the fields of food, medicine, and cosmetics. The structure of MBPs determines their biological activities. Therefore, it is essential to analyze the relationship between the structure and bioactivity of MBPs. Because of the advantages of mild conditions, high specificity, safety, and environmental friendliness, enzymatic hydrolysis has become the most commonly used method to produce MBPs. However, the high cost and low yield of enzymatic methods have motivated researchers to search for alternative technologies. Novel pretreatments like ultrasound, microwave, high hydrostatic pressure, and pulsed electric fields have been employed in the production of MBPs. By inducing protein unfolding and increasing enzymatic cleavage sites, these techniques have been demonstrated to accelerate protein hydrolysis and enhance the biological activity of MBPs. This article reviews recent research advances on marine-derived protein hydrolysates and peptides, discusses the relationship between their biological activity and structure, and compares the mechanisms of action of different novel technologies used to promote protein hydrolysis and enhance the biological activity of MBPs. In addition, the current challenges facing the development and application of MBPs are outlined and possible future work in tackling these challenges is also suggested in the current review. It is hoped that this review can promote further development and application of marine active substances. [ABSTRACT FROM AUTHOR]

The synthesis of chitosan-selenium nanoparticles (CS-SeNPs) through in situ reduction of selenite-Vc using chitosan (CS) as a template were extensively investigated. However it was important to consider the potential influence of Vc on the stable phase of freshly prepared CS-SeNPs, and not just its role in reducing selenite. In this study, we prepared CS(I)-SeNPs and CS(h)-SeNPs utilizing chitosan with varying molecular weights (3 kDa and 200 kDa) as templates, respectively. Firstly, we compared and characterized the differences in microscopic morphology and chemical structure between these two types of nanoparticles, as well as to investigate changes in particle size, ζ-potential, microscopic morphology, and elemental composition of the CS-SeNPs over time following removal of Vc treatment. Furthermore, we analyzed transformation of selenium's crystalline structure and the chemical structure of CS-SeNPs during stable phase of freshly prepared CS-SeNPs by using X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). The results demonstrated that when Vc was removed on the first day of stable phase, the particle sizes of both CS-SeNPs increased initially but remained stable thereafter. Additionally, ζ-potential gradually decreased over time; however after 14 days. the removement of Vc caused aggregation of CS(I)-SeNPs, while had less impact on CS(h)-SeNPs. Moreover, our findings indicated that Vc could influence both the chemical structure within the system by affecting O-H and N-H hydrogen bonding interactions among sugar chain molecules during stable phase of CS-SeNPs as well as selenium's crystalline structure. This study presents novel insights into the stable phase of freshly prepared nanoparticles from Vc or other reducing small molecules when employed in an in-situ approach. [ABSTRACT FROM AUTHOR]

Purpose: Lubricant eye drops are the main therapeutic resource for dry eye disease (DED), with each drop representing the equivalent of ocular surface disease treatment. Thus, any reduction in the frequency of eye drop application reflects a degree of therapeutic success. Considering also the socioeconomic burden of DED, we investigated eye drop application frequency (DF) as a parameter to potentially track the success of therapy in severe DED. Hyaluronan (HA)‐containing eye drops have become the first choice for tear substitution in many countries, and recent data indicate that the average molecular weight (Mw) of HA determines the therapeutic efficacy of such eye drops. This post‐hoc subgroup analysis of a previously published multicentre prospective randomized open‐label study, HYLAN M, is set out to compare the effects of very high Mw HA (hylan A) eye drops to comparator eye drops, containing lower Mw HA (control). Methods: Patients with severe DED (n = 47), recruited as part of the larger HYLAN M prospective, multicentre, open‐label study, were randomized into two groups: hylan A and control group. In the hylan A group, 24 patients replaced their HA‐containing eye drops with eye drops containing 0.15% hylan A, whereas the 23 control patients continued to use comparator HA eye drops. The DF was recorded daily by all participants over 8 weeks, and other subjective and objective parameters of DED were assessed at the time of inclusion (baseline), as well as at week 4 and 8. Results: There was a significant decrease in DF in the hylan A users between the baseline and week 4 (p = 0.004), remaining stable until week 8. Indeed, in contrast to the baseline, the hylan A group had a significantly lower DF than the control group at weeks 4 (p = 0.018) and 8 (p = 0.008). Likewise, the ocular surface disease index (OSDI) improved significantly between the time of inclusion and week 4 (p < 0.001) in hylan A users, remaining stable until week 8. The OSDI was similar in both groups at the baseline but it was significantly lower in the hylan A group than in the control group at week 4 (p = 0.002), remaining lower at week 8. Such a decrease in the DF and OSDI was not witnessed in the control group at any time point. The objective parameters assessed did not differ significantly within or between the two groups. Conclusion: When treating severe DED, the DF can be significantly reduced by using very high Mw HA (3 MDa) lubricant eye drops, which better alleviate DED symptoms and decrease the OSDI scores. These drops not only provide an attractive and comfortable alternative for patients with severe DED but also offer the possibility of reducing the disease's socioeconomic burden, both for affected individuals and society as a whole. [ABSTRACT FROM AUTHOR]

Summary: Processing by proteases irreversibly regulates the fate of plant proteins and hampers the production of recombinant proteins in plants, yet only few processing events have been described in agroinfiltrated Nicotiana benthamiana, which has emerged as the main transient protein expression platform in plant science and molecular pharming.Here, we used in‐gel digests and mass spectrometry to monitor the migration and topography of 5040 plant proteins within a protein gel. By plotting the peptides over the gel slices, we generated peptographs that reveal where which part of each protein was detected within the protein gel.These data uncovered that 60% of the detected proteins have proteoforms that migrate at lower than predicted molecular weights, implicating extensive proteolytic processing. This analysis confirms the proteolytic removal and degradation of autoinhibitory prodomains of most but not all proteases, and revealed differential processing within pectinemethylesterase and lipase families. This analysis also uncovered intricate processing of glycosidases and uncovered that ectodomain shedding might be common for a diverse range of receptor‐like kinases. Transient expression of double‐tagged candidate proteins confirmed processing events in vivo.This large proteomic dataset implicates an elaborate proteolytic machinery shaping the proteome of N. benthamiana. [ABSTRACT FROM AUTHOR]

The study of the dynamics of nucleic acids in solution, their flow properties, and viscoelasticity is of great importance for understanding their biological functions. Many important properties of nucleic acids, such as DNA, depend on polymer concentration, CDNA, molecular weight (MW), rigidity, and external salt content, the latter parameter affecting electrostatic interactions. Furthermore, DNA molecular chains can organize, in vitro, into liquid crystalline phases at high CDNA. In this work, three DNA samples with different MW were studied in solution in a broad concentration range (CDNA from 0.025 to 200 mg mL−1, depending on DNA MW). Firstly, the intrinsic viscosities and MW for all DNA samples were determined through capillary and rheological measurements. Then, the overlap concentrations, C*, were estimated from the relation C* ≈ [η]−1. DNA chain characteristics were then analyzed in terms of the influence of DNA MW on the solution viscosities and on the overlap parameter, CDNA[η]. Flow birefringence appearance was identified by screening a wide CDNA range through visual observations with crossed polarizers. Finally, crossed‐light polarized microscopy was used to identify the appearance of liquid crystals at rest, confirming that higher CDNA are needed to obtain liquid crystals for low MW DNA samples. [ABSTRACT FROM AUTHOR]

Urea–formaldehyde (UF) and phenol–formaldehyde (PF) resins are the most widely used adhesives in the production of wood composites, and are cured through hot-pressing to provide adhesion strength with the composites. This study investigates the relationship between thermal curing behavior monitored by differential scanning calorimetry (DSC) and adhesive bond strength development measured by an automated bonding evaluation system (ABES) for UF and PF resins with different molecular weights (Mw). DSC results demonstrated that UF resins cured faster than PF resins, as indicated by a lower apparent activation energy (Ea). In addition, UF and PF resins with lower Mw cured faster in the early stages of curing and slower in the latter stages of curing as compared to higher-Mw resins. Furthermore, according to the ABES results, when increasing the molecular weight, both UF and PF resins exhibited greater adhesive bond strength, irrespective of pressing parameters (temperature and time). The isothermal DSC and ABES results demonstrated that the adhesive bond strength increased with an increase in the degree of cure of the resins, indicating a correlation between them. It also showed that UF resins attained optimal adhesive bond strength at low temperature (110–130 °C) in roughly 180 s while PF resins attained it at high temperature (120–130 °C) in about 300 s. However, the degree of cure under isothermal scans was inconsistent with temperatures. These results indicate that the degree of cure is closely related to the adhesion strength development of UF and PF resins which are curing at low and high temperatures to obtain the optimum adhesion strength. [ABSTRACT FROM AUTHOR]

Mytilaria laosensis, a common fast-growing tree species in southern China, boasts excellent growth speed and attractive color and texture. However, due to its short growth cycle and high proportion of juvenile wood, it typically exhibits poor dimensional stability and low strength, which significantly limits its practical applications. This study uses vacuum impregnation to modify M. laosensis wood with polyethylene glycol (PEG), focusing on the effects and mechanisms of PEG with different molecular weights on wood properties. The results indicate that PEG enters the wood cell walls through capillary action and diffusion, forming hydrogen bonds with the free hydroxyl groups on cellulose and hemicellulose, which keeps the cell walls swollen and enhances dimensional stability. Post modification, the dimensional stability of M. laosensis wood improved, with an anti-swelling efficiency ranging from 61.43% to 71.22%, showing an initial increase followed by a decrease with increasing PEG molecular weight. The optimal PEG molecular weight for anti-swelling efficiency was 1500 Da, achieving 71.22%. The flexural modulus of elasticity and flexural strength of the treated wood also first decreased and then increased with increasing PEG molecular weight. Among them, the PEG1000-treated material showed the best performance, with the flexural modulus of elasticity increased by about 29% and the flexural strength increased by about 5% compared to untreated wood. Additionally, PEG, having a higher pyrolysis temperature than wood, raised the initial pyrolysis temperature and maximum pyrolysis rate temperature of M. laosensis wood, thus improving its thermal stability. These findings provide scientific evidence and technical support for the efficient utilization and industrialization of M. laosensis wood, promoting its widespread application and industrial development. [ABSTRACT FROM AUTHOR]

This study investigated the physical aging behavior of commodity polymers, specifically polystyrene (PS) and poly(methyl methacrylate) (PMMA), across various molecular weights (MWs). Using ellipsometry, we examine the physical aging behavior of bulk polymer films supported on silicon across a wide range of quench depths below glass transition temperature. At shallow quench depths, where the physical aging behavior is thermodynamically controlled, we observe that the physical aging rate for both PS and PMMA increases with decreasing MW. The MW dependence of the physical aging rate in the thermodynamic‐control region is hypothesized to originate from the MW dependence of the fractional free volume. In support of this hypothesis, we observe that the difference in thermal expansivity between the rubbery state and the glassy state (αrubbery − αglassy), which has been demonstrated to be positively related to fractional free volume, exhibits a similar MW dependence as the physical aging behavior. This correlation lends support to the free volume model of physical aging. Building on the free volume model, we propose a method to tune the physical aging behavior, demonstrating that incorporating flexible chain ends alters the physical aging behavior in a manner akin to reducing MW. Highlights: Polystyrene and poly(methyl methacrylate) have maximum physical aging rates at specific quench depths.Physical aging behavior is thermodynamically or kinetically controlled.With thermodynamic control, the aging rate increases with a reduction in molecular weight.With thermodynamic control, the aging rate correlates with free volume.Aging behavior can be tuned by blending with low MW polymer with highly flexible chain ends. [ABSTRACT FROM AUTHOR]

In the environment, the class of chemicals known as polycyclic aromatic hydrocarbons (PAHs) behave somewhat differently. This review covers situations where PAHs can be 'labile' and where they can be persistent. The in-silico prediction of toxicity and the properties of selected 29 PAHs were estimated using programs developed by the U.S. Environmental Protection Agency (EPA), such as the Estimation Programs Interface (E.P.I.) and the Toxicity Estimation Software Tool (version 5.1.2) (TEST), with online software such as SwissADME and SwissDock. TEST was used to estimate the LC50 of the fathead minnow (with a range of 14.53 mg/L for 1-indanone and 2.14 × 10−2 mg/L for cyclopenta[c,d]pyrene), the LC50 of Daphnia magna (with a range of 14.95 mg/L for 1-indanone and 7.53 × 10−2 mg/L for coronene), the IGC50 of Tetrahymena pyriformis (with a range of 66.14 mg/L for 1-indanone and 0.36 mg/L for coronene), the bioconcentration factor (8.36 for 1,2-acenaphthylenedione and 910.1 for coronene), the developmental toxicity (0.30 (−) for 1,2-acenaphthylenedione and 0.82 (+) for 4-hydroxy-9-fluorenone), and the mutagenicity (0.25 (−) for 2-methyl-9-fluorenone and 1.09 (+) for coronene). The carbon chain and molecular weight have a significant effect on the properties of PAHs. Overall, it was found that PAHs with a lower molecular weight (LMW) have a higher water solubility and LC50 value and a smaller LogKow value, whereas the opposite is true for heavier PAHs, with TEST predicting that PAHs with an MW of over 168.2 g/mol, with a few exceptions, are mutagenic. Hence, LMW PAHs have a higher potential to be in the environment but are less toxic. [ABSTRACT FROM AUTHOR]

Nonconventional luminescent polymers have become research hotspots due to their advantages such as persistent room temperature phosphorescence (p‐RTP) emission and strong film‐forming properties. It is proven that the molecular weight (MW) of such luminescent polymers has a significant impact on their emission over a large range, generally with a red shift as the MW increases. Herein, four controllable MW polyacrylamides are prepared via reversible addition‐fragmentation chain transfer polymerization (RAFT), and their photoluminescence quantum yield and p‐RTP lifetimes gradually increase with the increasing MW. The emission of p‐RTP gradually shifts blue with increasing MW, which is likely due to the gradually changing interactions between the electron‐rich portion in RAFT reagent and the increasing acrylamide (AM) units in the molecular chain. These can be reasonably explained through small angle X‐ray scattering, the clustering‐triggered emission (CTE) mechanism, and supported by theoretical calculations. Powder with controllable p‐RTP capability has the potential for strategic anti‐counterfeiting encryption. The above results not only promote the development of the CTE mechanism toward more precise explanations but also provide new ideas for the preparation of nonconventional luminescent polymers with controllable p‐RTP emission performance. [ABSTRACT FROM AUTHOR]

The need for industrially and biotechnologically significant enzymes, such as phytase, is expanding daily as a result of the increased use of these enzymes in a variety of operations, including the manufacture of food, animal feed, and poultry feed. This study sought to characterize purified phytase from A. awamori AFE1 isolated from longhorn beetle for its prospect in industrial applications. Ammonium sulfate precipitation, ion-exchange chromatography, and gel-filtration chromatography were used to purify the crude enzyme obtained from submerged fermentation using phytase-producing media, and its physicochemical characteristics were examined. The homogenous 46.8-kDa phytase showed an 8.1-fold purification and 40.7% recovery. At 70 C and pH 7, the optimum phytase activity was noted. At acidic pH 4–6 and alkaline pH 8–10, it likewise demonstrated relative activity of 88–95% and 67–88%, respectively. It showed 67–70% residual activity between 30 and 70 C after 40 min, and 68–94% residual activity between pH 2 and 12 after 2 h. The presence of Hg+, Mg2+, and Al3+ significantly decreased the enzymatic activity, whereas Ca2+ and Cu2+ enhanced it. Ascorbic acid increased the activity of the purified enzyme, whereas ethylenediaminetetraacetic acid (EDTA) and mercaptoethanol inhibited it. The calculated values for Km and Vmax were 55.4 mM and1.99 μmol/min/mL respectively. A. awamori phytase, which was isolated from a new source, showed unique and remarkable qualities that may find use in industrial operations such as feed pelleting and food processing. [ABSTRACT FROM AUTHOR]

In present paper, structures and properties of degradation products of polystyrene (PS) waste were characterized by gel permeation chromatography (GPC), thermogravimetric (TG) analysis, Fourier transform infrared (FT-IR) spectroscopy, gas chromatography-mass spectrometry (GC-MS), and thus the degradation conditions including temperature, time, and assistant type and dosage were investigated and optimized. It is suitable to use 1.0 wt% K2S2O8 as an assistant to degrade PS waste at 300°C for 24 h. Subsequently by sulfonation and neutralization reactions, the degraded PS was prepared into sodium polystyrene sulfonate (PSS), a common dispersant for coal‒water slurry (CWS). The performance of PSS with different molecular weights and sulfonation degrees was studied. Experimental results showed that the PSS with the sulfonation degree of more than 75%, prepared from the degraded PS having number average molecular weight (Mn) of about 9000, was appropriate for dispersion and stabilization of CWS suspensions. Additionally, compared with commercial dispersant NSF, the obtained PSS had a better performance for CWS. CWSs prepared with dispersant PSS exhibited pseudo-plastic or shear-thinning rheological behaviors. Combined with coal‒water slurry technology, a new approach is provided for resource utilization of PS waste. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Chinese Institute of Food Science & Technology is the property of Journal of Chinese Institute of Food Science & Technology Periodical Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study was aimed to investigate the effect of cold plasma on chitosan powder properties at two different power levels (22 kV and 25 kV) and four different times (0, 4, 8, and 12 min). The treated and control chitosan powder were analyzed to determine any changes in their physicochemical, structural, functional, and thermal properties. The plasma treatment notably reduced the moisture content of the sample. Increasing the plasma voltage and exposure time resulted in an increase in solubility (2.42% and 5.02%, respectively) and water binding capacity (4.09% and 8.45%, respectively) of the samples. However, there was a decrease in fat binding capacity of approximately 5.41% and 5.09% (p < 0.05) under the same conditions. The plasma treatment markedly reduced the average molecular weight of chitosan samples, with the control having the highest molecular weight (1543.16 kDa) and the sample treated at 25 kV for 12 min showing the lowest (1511.21 kDa). Although there was no observed change in the functional group of the control and treated chitosan powder, the X-ray diffractometer and scanning electron microscopy analyses indicated an increase in crystallinity. Furthermore, the differential scanning calorimetry analysis of the control and treated chitosan showed that the treated samples exhibited lower melting and decomposition enthalpies. This study's results demonstrate that cold plasma can serve as an eco-friendly method, due to its reduced chemical usage, for effectively altering the functional properties of chitosan. This opens up possibilities for a wider range of applications in both the food and polymer industries. [ABSTRACT FROM AUTHOR]

In this article, we investigated the influence of molecular weight (Mw) on particle deposition efficiency after PEG-functionalized (polyethylene glycol-PEG) magnetoresponsive magnetic cluster targeting. In this work, the clusters were obtained by the solvothermal polyol method using polyethylene glycol (PEG) as a coating agent. So, we investigated three kinds of magnetoresponsive clusters: MNC-2000, MNC-6000, and MNC-10,000. These clusters were coated with PEG, and had molecular weights (Mw) of 2000 Da, 6000 Da, and 10,000 Da, respectively. The authors propose that the key to achieving maximum efficiency in targeted drug delivery is to deposit a thin, uniform layer of medication that covers the vascular wall in the area of interest. We defined a set of efficiency criteria to focus on the most essential characteristics of the targeting results. These are the obstruction degree, which measures the level of vessel obstruction; the magnet coverage degree, which evaluates the quality of particle deposition along the vessel wall; and the proximal deposition degree, which assesses the effect of pulsatile flow on deposition length. We performed several tests to determine how molecular weight affected these efficiency parameters. These tests examined (a) the effect of the injected cluster quantities, (b) the effect of the magnet distance, and (c) the effect of the injection period. Our findings indicate that an increase in PEG's molar weight significantly impacts magnetic particle targeting efficiency. [ABSTRACT FROM AUTHOR]

Shear relaxation behavior for polymer melt exists in different processing techniques and influences the dimensional accuracy and production efficiency of polymer products. A micro physical and mathematical model based on microstructure of polymer chains and processing parameters was established and verified by experimental results obtained from a torque rheometer. The shear relaxation time of polypropylene degraded by di‐tert‐butyl peroxide was characterized with torque rheometer. The effects of microstructure and processing parameters on the shear relaxation time was investigated. The results showed that a wider molecular weight distribution could result in a decrease in shear relaxation time and polypropylene chains with higher molecular weight were more sensitive to molecular weight distribution. The shear relaxation time declined exponentially with shear rate and increased with internal pressure. The temperature could enhance the movement of polymer chains and reduce the shear relaxation time linearly, but polypropylene with lower molecular weight was less sensitive to temperature. The insight obtained from the mathematical and experimental results can be profoundly applied in practical process control to manufacture product with better dimensional stability and production efficiency for viscoelastic polymer. Highlights: A physical and mathematical model based on microstructure and processing parameters of molecular chains was established to explore the shear relaxation mechanism.Shear relaxation time of polypropylene degraded by di‐tert‐butyl peroxide was characterized with the help of torque rheometer.The effects of microstructure and processing parameters on shear relaxation time was investigated to optimize the manufacturing of polypropylene products. [ABSTRACT FROM AUTHOR]

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the polymerization behavior and polymer properties, hindered phenol is added as the third compound in a mature metallocene catalyst system, Ph2C(Cp)(Flu)ZrCl2-MAO, for ethylene (co)polymerization in this study. The steric hindered phenols reduce the chain transfer ability of free trimethylaluminum in the system. At the same time, the chemical environment surrounding the active center was changed, giving it greater steric hindrance. It results the increases of molecular weight of ethylene homopolymer and ethylene-1-octene copolymer (from 61.4k to max. 208.8k for ethylene homopolymerization and from 49.6k to max. 100.3k). And the activity for ethylene homopolymerization slightly increased (from 498 to max. 654 kg-PE/mol-cat/hr) and that for ethylene/1-octene decreased (from 1128 to min. 870 kg-copolymer/mol-cat/hr). The incorporation of 1-octene increased only in one polymerization (from 15.3 to 16.8 mol%), while others decreased (to min. 11.5 mol%). It is also found that the introduction of the third compound changed the distribution of monomers in the polymer chain, therefore it is believed that the third compound is involved in the formation of active center. These changes are closely related to the structure and dosage of steric hindered phenols. [ABSTRACT FROM AUTHOR]

This work systematically studies the role of polymer chain length and number density of enantiomeric polylactides (PLAs) in the gel state stereocomplex (SC) formation and the corresponding effect on the structure and morphology of aerogels. Poly(l‐lactide) (PLLA) and poly(d‐lactide) (PDLA) with large molecular weight (Mw) differences are blended in the solution state and subjected to thermoreversible gelation. The obtained gels are solvent exchanged with water and freeze‐dried to obtain the corresponding aerogels. On gelation, the equimolar blend gels of PLLA100k/PDLA35k and PLLA100k/PDLA15 (1:1) have crystallized predominantly into SC, and this structure remains even after the thermal annealing and cooling of the gel. In contrast, the non‐equimolar blends of PLLA100k/PDLA35k (1:3) and PLLA100k/PDLA15k (1:7) crystallize into almost equal fractions of SC and ε‐form. This structure on heating transforms to complete SC through the α crystalline phase. But unlike the equimolar gel, pure crystalline SC is not obtained on cooling the annealed gel to room temperature. Instead, a mixture of α and SC phases are obtained due to the independent crystallization of the excess enantiomeric chains. Thus, it has been proved that the composition of PLLA and PDLA in the blend is critical in obtaining crystalline pure SC gels and aerogels. [ABSTRACT FROM AUTHOR]

Copyright of Acta Edulis Fungi is the property of Acta Edulis Fungi and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A lot of literature sources discuss diseases associated with the hemoglobin protein [1-2]. In the modern world, more than 800 million people suffer from anemia [3]. Assessing the level of hemoglobin in the circulatory system is one of the ways to diagnose anemia. Hemoglobin protein is also a promising source of bioactive peptides [4]. The aim of the work was to identify the reasons leading to conformation changes of this protein. It still remains unclear what exactly causes disruption of its functionality. Human hemoglobin from Sigma H7379 was studied in the work; all experiments were conducted on a dynamic light scattering spectrometer—Photocor Complex. Experimental data were obtained using optical methods of static and dynamic light scattering. The work included an analysis of the behaviour of hemoglobin protein molecules in aqueous and aqueous-saline solutions with changes in solution parameters (pH, addition of iron chloride III). At values of pH and pH , the hemoglobin molecule underwent conformational changes, resulting in the disintegration of the quaternary structure into -dimers and individual - and -globules. As a result of the study, it was found that the addition of FeCl to aqueous solutions of hemoglobin increases the size and mass of scattering particles, which can be explained by the adsorption of Fe ions on the protein surface. However, upon reaching a certain concentration of FeCl , the pH of the solution was lowered to such an extent that it caused conformational changes in hemoglobin, leading to the disintegration of its quaternary structure. These results can be taken into account when creating medicinal drugs for the treatment of anemia and other diseases associated with the hemoglobin protein. [ABSTRACT FROM AUTHOR]

Polyoxymethylene (POM) is a fast crystallizing polymer, whose structure is highly dependent on the processing conditions and is showing a broad range of mechanical properties. Three POM materials with different molecular weights were selected and a design of experiments (DoE) was performed varying melt temperature, mold temperature, and injection speed. In combination with increased viscosity at higher molecular weights, the flow resistance and shear stresses will also increase at a certain injection speed and geometric conditions. Thereby, the range of morphological differences depends not only on the process boundary conditions but also on the rheological conditions. This aspect is particularly relevant for micro-injection molded parts, as the acting cooling and shearing rates are much higher than in standard injection molding. A specially designed tensile rod with a radially symmetric cross section was utilized for the experiments, which offers advantages in terms of a symmetric flow and cooling behavior. The morphology was studied with thin sections from the center of the sample. Differential Scanning Calorimetry (DSC) was used to study the crystallinity of the samples and the mechanical properties were determined by a tensile test using an adopted optical extensometer. The mechanical properties of low molecular weight POM are only to a minor extent affected by the process variations. However, higher molecular weight POM is greatly affected in terms of its skin layer formation and improved mechanical properties favored by a low injection velocity.

Abstract In the development of polymer electrolytes, the understanding of the complex interplay of factors that affect ion transport is of importance. In this study, the strongly coordinating and flexible poly (ethylene oxide) (PEO) is compared to the weakly coordinating and stiff poly (trimethylene carbonate) (PTMC) as opposing model systems. The effect of molecular weight (Mn) and end group chemistry on the physical properties: glass transition temperature (Tg) and viscosity (η) and ion transport properties: transference number (T+), ion coordination strength and ionic conductivities were investigated. The cation transference number (T+) showed the opposite dependence on Mn for PEO and PTMC, decreasing at low Mn for PTMC and increasing for PEO. This was shown to be highly dependent on the ion coordination strength of the system regardless of whether the end group was OH or if the chains were end‐capped. Although the coordination is mainly of the cations in the systems, the differences in T+ were due to differences in anion rather than cation conductivity, with a similar Li+ conductivity across the polymer series when accounting for the differences in segmental mobility.