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‘Zijia 1’ is a new variety of Acanthopanax senticosus bred by our team, its tender stems and leaves characterized with gray-purple color and sweet taste. This study is aim to isolate and purify the polysaccharides from the tender stems and leaves of ‘Zijia 1’, and determine the monosaccharide composition and molecular weight of different fractions obtained after separation, and the antioxidant activity of each fraction was evaluated. The crude Asenticosus polysaccharides (ASPS) were obtained from the tender stems and leaves of ‘Zijia 1’ by water extraction and alcohol precipitation, which were then separated and purified by DEAE-Cellulose 52 ion column and Sephadex G-100 gel column to obtain a uniform component. The ion chromatography and gel permeation chromatography-refractive index-multi-angle laser light scattering method was exploited to determine the monosaccharide compositions and molecular weight of the polysaccharides fractions. The hydroxyl radical (·OH), superoxide radical (O2-·) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging ability were determined to evaluate the antioxidant of each fraction in vitro. Four polysaccharides ASPA-1-1, ASPA-2-1, ASPA-3-1 and ASPN-1 were isolated and purified from ASPS, with molecular weight of 8.10, 26.15, 0.91, 0.89 kDa, respectively, mainly composed of arabinose, rhamnose, galactose, glucose, xylose, mannose, ribose, galacturonic acid and glucuronic acid in different proportions. The ASPA-1-1, ASPA-2-1, ASPA-3-1 and ASPN-1 from ‘Zijia 1’ demonstrated significant scavenging activities on ·OH, O2-· and DPPH free radical, the ability of ASPA-2-1 to scavenge ·OH and DPPH is higher than ASPA-1-1, ASPA-3-1 and ASPN-1; ASPA-3-1 has the strongest ability to scavenge O2-·. Therefore, the purified polysaccharides from ‘Zijia 1’ has obvious antioxidant activity, which provides a scientific theoretical basis for its further utilization.

Tremella fuciformis is rich in nutrients, and Tremella fuciformis polysaccharide is the most important functional active component with a variety of biological activities. Tremella fuciformis polysaccharides can be prepared by various methods, and the research on its structure is mainly focused on molecular weight, monosaccharide components, and glycosidic bond type. This review summarizes the preparation, structure, and biological activities of Tremella fuciformis polysaccharides, such as antioxidant, anti-tumor, immune regulation, memory improvement, anti-inflammation, blood sugar and blood lipid lowering, and its development and application in food, cosmetics, and medicine. In the future, it is necessary to optimize the preparation technology of Tremella fuciformis polysaccharides, analyze the advanced structure of Tremella fuciformis polysaccharides with modern analytical techniques, and conduct in-depth research on the function and mechanism of action of Tremella fuciformis polysaccharides, so as to provide theoretical reference for the deep processing and product development of Tremella fuciformis fuciformis.

In this work, the consolidation of calcium carbonate (CaCO3) by polyacrylamide (PAM) of different molecular weights, charge densities, and functional groups was investigated via oscillatory rheology and unconfined compressive strength (UCS) analysis. Oscillatory rheology showed that the storage modulus G′ was approximately 10 times higher than the loss modulus G″, indicating a highly elastic CaCO3 sample upon consolidation via PAM. Both oscillatory rheology and UCS analysis exhibited similar trends, wherein the mechanical values (G′, G″, and UCS) first increased with increasing polymer dosage, until they reached a peak value (typically at 3 mgpol/gCaCO3), followed by a decrease in the mechanical values. This indicates that there is an optimum polymer dosage for the different PAM-CaCO3 colloidal systems, and that exceeding this value induces the re-stabilisation of the colloidal system, leading to a decreased degree of consolidation. Regarding the effect of the PAM molecular weight, the peak G′ and UCS values of CaCO3 consolidated by hydrolysed PAM (HPAM) of different molecular weights are very similar. This is likely due to the contour length of the HPAMs being either almost the same or longer than the average distance between two CaCO3 particles. The effect of the PAM charge density revealed that the peak G′ and UCS values decreased as the charge density of the PAM increased, while the optimum PAM dosage increased with decreasing PAM charge density. The higher likelihood of lower-charge PAM bridging between the particles contributes to higher elastic energy and mechanical strength. Finally, regarding the PAM functional group, CaCO3 consolidated by sulfonated polyacrylamide (SPAM) typically offers lower mechanical strength than that consolidated with HPAM. The bulky sulfonate side groups of SPAM interfere with the surface packing, reducing the number of polymers able to adsorb onto the surface and, eventually, reducing the degree of consolidation of CaCO3. The zeta potential of the PAM-CaCO3 samples became more negative with increasing PAM concentration due to the saturation of the particle surface. Good agreement between oscillatory rheology and UCS analysis could accelerate PAM screening for optimum CaCO3 consolidation.

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.

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.

IntroductionHyaluronic acid (HA) plays an important role in cellular and extracellular matrix (ECM) homeostasis. Recent studies demonstrate that low molecular weight (MW) HA has pro-inflammatory characteristics while high MW HA is considered anti-inflammatory and regenerative. In formulating a topical HA product, the possibility of creating a focused high MW HA technology was posed, combining external surface high MW HA constituents with active agents promoting fibroblast production of high MW in the depths of the dermis.MethodsHuman dermal fibroblasts and keratinocytes were treated with various agents, and RNA sequencing (RNA-seq) was conducted to identify genes involved in HA synthesis. HA production by fibroblasts was assessed by collecting the culture supernatant, concentrating the protein, and conducting polyacrylamide gel electrophoresis (PAGE). The gel was stained with Stains-All to identify bands relative to known HA products of different MWs. Subsequently, the supernatants were treated with hyaluronidase to confirm the bands corresponded to HA.ResultsThe RNA-seq results revealed a variety of agents upregulated HA-related genes. However, a potent upregulation of HA synthesis gene was observed by hexapeptide-11 in the keratinocytes and a newly identified proprietary octapeptide in the fibroblasts. PAGE demonstrated not only robust production of HA by octapeptide, but significantly, the HA produced was ~2 Mega Daltons in size. Octapeptide was the most potent stimulator among the tested agents.ConclusionComprehensive in vitro testing identified a group of active agents that stimulated high MW HA production. This novel approach to HA topical application with exclusively high MW HA production should maximize hydration capacity while encouraging regenerative activity within the ECM. Multi-center trials are underway.

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.)

The influences of various m-γ-PGA (0.08–0.20%, w/w) concentrations on the properties of minced beef meat paste in terms of rheological properties, texture, moisture distribution, and microstructures were evaluated. The results indicated that m-γ-PGA enhanced the water-holding capacity, gel strength, texture, and whiteness of the minced beef meat paste. Based on the microstructural results, m-γ-PGA helped form a more organized and compact gel, thereby limiting the migration of water through the gel matrix. In contrast to the control group, the water-holding property, gel strength, and whiteness of minced meat paste gels with m-γ-PGA content of 0.12% increased from 75.89%, 584.51 g·cm, and 61.83 to 79.91%, 780.87 g·cm, and 62.54, respectively (p < 0.05), exhibiting the highest water-holding property and gel strength. Thus, m-γ-PGA exhibits great potential for minced meat paste products as a healthy gel water retainer and enhancer in low-fat meat products. [ABSTRACT FROM AUTHOR]

Free radical polymerization was selected to obtain a promising copolymer scale inhibitor IA‐AM‐SAS with good water solubility and temperature and salt resistance, which is suitable for the treatment of surface pipeline water in oil fields, using itaconic acid (IA), acrylamide (AM), and sodium acrylsulfonate (SAS) as the monomers. The structure of the synthesized copolymer was verified by Fourier transform infrared spectroscopy and nuclear magnetic resonance hydrogen spectroscopy. Thermogravimetric results showed that the copolymer does not undergo significant thermal degradation at temperatures below 356°C, indicating that the copolymer has good thermal stability. The molecular weights of the polymers at different monomer ratios were measured using gel permeation chromatography and the relationship between the molecular weights and scale inhibition performance was discussed. The results showed that the scale inhibition effect was best when the monomer molar ratio n(IA): n(AM): n(SAS) was 0.5:2:1.5 and the number of average molecular weight of the prepared copolymer was 7712 g/mol, and the inhibition efficiency of CaCO3 was 84.02% when IA‐AM‐SAS was at a concentration of 30 mg L−1, and the inhibition rate was measured by the standard of static scale inhibition test in the oilfield measured. The range of conditions (PH, Ca2+ concentration, water temperature, and time) of the static scale inhibition test was then expanded using a one‐way controlled variable experiment to explore the performance of IA‐AM‐SAS scale inhibitors under different water quality conditions. The scale inhibition mechanism was explored by scanning electron microscopy, x‐ray diffraction, and x‐ray photoelectron spectroscopy. Briefly, the combination of multiple functional groups enables IA‐AM‐SAS to be applied in complex and challenging environments. [ABSTRACT FROM AUTHOR]

Paramylon, a starch-like carbohydrate accumulated in Euglena gracilis cells, could be a potential source as a raw material for chemical products; its high-yield production would thus be highly desired. Although the molecular weight and polymerization degree of paramylon are important properties for its use as a raw material for chemical products, the available information about paramylon molecular weight remains insufficient. Therefore, in this study, we investigated a high-density E. gracilis culture approach and how culture conditions affect paramylon molecular weight. The nitrogen source, cultivation temperature, and nutrient feeding were optimized for maximum biomass and paramylon productivity. The maximum dry cell weight and paramylon content yields reached 108.9 g/L and 87.2%, respectively. Paramylon molecular weight was in the range of 220 000–320 000 Da. Our gel permeation chromatography analysis showed that the cells with a higher paramylon content tended to contain paramylon of a higher molecular weight. [ABSTRACT FROM AUTHOR]

Obesity is consistently linked to skeletal muscle atrophy. It is characterized by a chronic inflammatory state that produces various pro-inflammatory substances that may have negative effects on muscles, such as muscle atrophy, impaired muscle regeneration, and a reduction in muscle protein synthesis. Fucoidan, isolated from the brown alga Undaria pinnatifida, is composed of fucose, galactose, and sulfate groups, and is known to have anti-obesity, anti-tumor, and immunomodulatory properties. Recent studies have indicated that the bioactivity of fucoidans depends on their molecular weight; however, this correlation remains unclear and requires further investigation. This study aimed to evaluate and compare the effects of three different fucoidans, based on their molecular weight, on palmitate (PA)-induced muscle atrophy using C2C12 myotubes. The fucoidan types were low molecular weight fucoidan (LMWF, ≥ 30 kDa), medium molecular weight fucoidan (MMWF, ≥ 110 kDa), and high molecular weight fucoidan (HMWF, ≥ 200 kDa). Our results demonstrate that all fucoidans reduced lipid accumulation. Additionally, all three fucoidans reduced tumor necrosis factor-alpha (TNF‐α) mRNA expression level in PA‐induced inflammation, whereas interleukin-1beta (IL‐1β) and IL‐6 mRNA expression levels were reduced only in the HMWF-treated group. Moreover, MMWF and HMWF significantly reduced the mRNA expression levels of the muscle atrophy genes muscle RING-finger protein-1 (MuRF1) and Atrogin‐1, while LMWF showed no significant effects. In conclusion, HMWF showed more promising outcomes than LMWF and MMWF, suggesting its potential as a therapeutic agent for the treatment of obesity-induced inflammation and muscle atrophy. [ABSTRACT FROM AUTHOR]

With an objective to produce superior quality natural rubber (NR) for preparing tyre treads, various coagulation techniques were attempted for NR latex such as mechanical stirring and heating, steam-induced, salt-induced and freeze–thaw process, from which their efficiency was compared with formic acid-coagulated natural rubber. The effect of coagulation methods on molecular weight and thermo-oxidative ageing of resulting rubber was evaluated. The processing and cure characteristics, rubber–filler interaction and mechanical properties of NR were also evaluated. Rubber separated by mechanical stirring followed by heating and freeze–thaw coagulation showed better retention of molecular weight coagulated NR field latex. FTIR spectrum detected a high amount of nitrogenous materials in rubber compared to acid-coagulated natural rubber. Gel permeation chromatography (GPC), Mooney viscosity and black incorporation time were used to characterise the rubber separated by different methods. Different coagulation techniques adopted have very little effect on the glass transition temperature (Tg). Technological and morphological properties of rubber obtained by stirring and freeze–thaw processes are superior compared to other processes. [ABSTRACT FROM AUTHOR]

‘Zijia 1’ is a new variety of Acanthopanax senticosus bred by our team, its tender stems and leaves characterized with gray-purple color and sweet taste. This study is aim to isolate and purify the polysaccharides from the tender stems and leaves of ‘Zijia 1’, and determine the monosaccharide composition and molecular weight of different fractions obtained after separation, and the antioxidant activity of each fraction was evaluated. The crude Asenticosus polysaccharides (ASPS) were obtained from the tender stems and leaves of ‘Zijia 1’ by water extraction and alcohol precipitation, which were then separated and purified by DEAE-Cellulose 52 ion column and Sephadex G-100 gel column to obtain a uniform component. The ion chromatography and gel permeation chromatography-refractive index-multi-angle laser light scattering method was exploited to determine the monosaccharide compositions and molecular weight of the polysaccharides fractions. The hydroxyl radical (OH), superoxide radical (O2-) and 1,1-diphenyl-2-picrylhydrazyl radical (DPPH) scavenging ability were determined to evaluate the antioxidant of each fraction in vitro. Four polysaccharides ASPA-1-1, ASPA-2-1, ASPA-3-1 and ASPN-1 were isolated and purified from ASPS, with molecular weight of 8.10, 26.15, 0.91, 0.89 kDa, respectively, mainly composed of arabinose, rhamnose, galactose, glucose, xylose, mannose, ribose, galacturonic acid and glucuronic acid in different proportions. The ASPA-1-1, ASPA-2-1, ASPA-3-1 and ASPN-1 from ‘Zijia 1’ demonstrated significant scavenging activities on ·OH, O2-· and DPPH free radical, the ability of ASPA-2-1 to scavenge ·OH and DPPH is higher than ASPA-1-1, ASPA-3-1 and ASPN-1; ASPA-3-1 has the strongest ability to scavenge O2-·. Therefore, the purified polysaccharides from ‘Zijia 1’ has obvious antioxidant activity, which provides a scientific theoretical basis for its further utilization. [ABSTRACT FROM AUTHOR]

Glucomannan carboxymethylation is conducted to increase its hydrophobic properties and expand its interaction with hydrophobic compounds. However, glucomannan has high molecular weight and long polysaccharide chain which prevented the modification of its amphiphilic properties. This study aimed to examine the effect of molecular weight, deacetylation, and carboxymethylation on glucomannan properties. Performance of the modified glucomannan to stabilize oil in water (o/w) emulsion was also studied. Ultrasonication was applied to glucomannan at 40 kHz for 15-45 min to obtain various molecular weights. Sodium carbonate (Na2CO3) and sodium monochloroacetate were used as deacetylation and carboxymethylation agents, respectively. The results show that decrease molecular weight supported the deacetylation and the carboxymethylation process on attaching the hydrophobic groups to the glucomannan chain, hence, lowering the hydrophilic properties and swelling degree of glucomannan. Structural and morphological changes of glucomannan after modifications were confirmed from the IR spectra and SEM images. Excellent performance of the amphiphilic glucomannan on stabilizing o/w emulsion was observed as only ~5% phase separation occurred after 300 h of storage in ambient conditions. Hence, ultrasonication is proposed as a suitable preliminary treatment for amphiphilic glucomannan production. [ABSTRACT FROM AUTHOR]

The migration of arsenic in groundwater is controlled by the adsorption of iron-containing minerals, and natural organic matter also has a great influence on arsenic adsorption during the adsorption process. The effects of humic acids with different molecular weights on the isotherms and adsorption kinetics of arsenic adsorption on goethite, as well as the mechanism of these effects, were studied via zeta potential, Fourier transform infrared spectroscopy, and three-dimensional fluorescence analysis. The results showed that the adsorption of arsenic in the low molecular weight inhibited the adsorption capacity from 25.1 to 14.5 mg.g−1, while the medium molecular weight promoted the adsorption capacity from 25.6 to 32.3 mg.g−1, and the high molecular weight humic acid had little effect on arsenic adsorption. The surface charge analysis revealed that there was competitive adsorption between arsenic and humic acid, and as the molecular weight of the humic acid increased, the amount of negative charge on the surface of the goethite increased. The infrared spectroscopy results showed that an arsenic-goethite-organic matter ternary complex was formed. The three-dimensional fluorescence spectroscopy indicated that the humic acid fluorescence was quenched after the addition of arsenic. [ABSTRACT FROM AUTHOR]

Chicken collagen is a promising raw material source for the production gelatins and hydrolysates. These can be prepared biotechnologically using proteolytic enzymes. By choosing the appropriate process conditions, such changes can be achieved at the molecular level of collagen, making it possible to prepare gelatins with targeted properties for advanced cosmetic, pharmaceutical, medical, or food applications. The present research aims to investigate model samples of chicken gelatins, focusing on: (i) antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azinobis-3-etylbenzotiazolin-6-sulfonic acid (ABTS); (ii) the distribution of molecular weights via gel permeation chromatography with refractometric detection (GPC-RID); (iii) functional groups and the configuration of polypeptide chains related to molecular-level properties using Fourier transform infrared spectroscopy (FTIR); (iv) the microbiological populations on sabouraud dextrose agar (SDA), plate count agar (PCA), tryptic soy agar (TSA), and violet red bile lactose (VRBL) using the matrix-assisted laser desorption ionization (MALDI) method. Antioxidant activity towards ABTS radicals was more than 80%; activity towards DPPH radicals was more than 69%. The molecular weights of all gelatin samples showed typical α-, β-, and γ-chains. FTIR analysis confirmed that chicken gelatins all contain typical vibrational regions for collagen cleavage products, Amides A and B, and Amides I, II, and III, at characteristic wavenumbers. A microbiological analysis of the prepared samples showed no undesirable bacteria that would limit advanced applications of the prepared products. Chicken gelatins represent a promising alternative to products made from standard collagen tissues of terrestrial animals. [ABSTRACT FROM AUTHOR]

Organic electrochemical transistors (OECTs) have gained considerable attention due to their potential applications in emerging biosensor platforms. The use of conjugated polyelectrolytes (CPEs) as active materials in OECTs is particularly advantageous owing to their functional, water‐processable, and biocompatible nature, as well as their tunable electronic and ionic transport properties. However, there exists a lack of systematic studies of the structure‐property relationships of these materials with respect to OECT performance. This study shows how by tuning the molecular weight of self‐doped CPE (CPE‐K) it is possible to fabricate OECTs with a µC* value of 14.7 F cm−1 V−1 s−1, one order of magnitude higher than previously reported CPE‐based devices. Furthermore, OECTs with a transconductance of 120 mS are demonstrated via device engineering. While CPE‐K batches with different molecular weights show good doping behavior and high volumetric capacitance, as confirmed by spectroelectrochemistry and electrochemical impedance spectroscopy, the medium molecular weight possesses the highest carrier mobility of ≈0.1 cm2 V−1 s−1 leading to the highest transconductance. The enhanced charge transport is due to a favorable charge percolation pathway, as revealed by the combination of X‐ray analysis and conductive atomic force microscope. These insights provide guidelines for further improving the performance of CPE‐based OECTs. [ABSTRACT FROM AUTHOR]

Summary: Hard capsules are a frequently used oral medication delivery form. This study aims to evaluate the potential of tilapia fish gelatine as a suitable material for hard capsules, by analysing various gelatine properties under different extraction temperatures (50, 60, 70, and 80 °C) and extraction periods (6 and 12 h). The results showed a range of values for the gelatine yield (22–33% (w/w)), gel strength (141–360 g), molecular weight distribution (140–300 kDa), and amino acid composition (185–220/1000 residues). FG70‐12 (296) and FG60‐6 (266) were found to have gel strength between 200 and 300 g thus suitable to be used as hard capsule material. Interestingly, the strongest gelatine having 360 g gel strength obtained from FG50‐6 (fish gelatine extracted at 50 °C for 6 h) became the essential ingredient for preparing hard capsules because two times dipping was enough to obtain the standard weight and thickness. A slight loss of moisture was identified during drying and rapid dissolution (4–8 min) detected from fish gelatine capsule at pH 6.8 or below. Therefore, hard capsules for pharmaceutical applications could be developed from fish gelatine as an alternative gelatine with similar properties as commercial hard capsules and satisfying the pharmacopoeia standard. [ABSTRACT FROM AUTHOR]

Akanes are fluorescent proteins that have several fluorescence maxima. In this report, Akane1 and Akane3 from Scleronephthya gracillima were selected, successfully overexpressed in Escherichia coli and purified by affinity chromatography. Fluorescence spectra of the recombinant Akanes matured in darkness, or ambient light were found to have several fluorescence peaks. SDS-PAGE analysis revealed that Akanes matured in ambient light have two fragments. MS/MS analysis of Akanes digested with trypsin showed that the cleavage site is the same as observed for the photoconvertible fluorescent protein Kaede. The differences between the calculated masses from the amino acid sequence of Akane1 and the measured masses of Akane1 fragments obtained under ambient light coincided with those of Kaede. In contrast, a mass difference between the measured N-terminal Akane3 fragment and the calculated mass indicated that Akane3 is modified in the N-terminal region. These results indicate that numerous peaks in the fluorescent spectra of Akanes partly arise from isoproteins of Akanes and photoconversion. Photoconversion of Akane1 caused a fluorescence change from green to red, which was also observed for Akane3; however, the fluorescent intensity decreased dramatically when compared with that of Akane3. [ABSTRACT FROM AUTHOR]

Copyright of Polymer Materials Science & Engineering is the property of Sichuan University, Polymer Research Institute 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 piloted and the spontaneous ignition of low and high molecular weight (LMW and HMW) polymethyl methacrylate are simulated using a one-dimensional condensed-gas phase model for constant heat fluxes in the range of 25–150 kW/m2. Purely thermal (nitrogen) and thermo-oxidative (air) decomposition is considered, described by a single and four-step kinetics for the low and high molecular weight polymer, respectively. Different optical properties are also examined. The same trends of the ignition time and other ignition parameters are always observed. Due to a more significant role of the chemical kinetics, the effects of the sample molecular weight and reaction atmosphere are higher at low heat fluxes. Times are shorter for the black HMW samples and thermo-oxidative kinetics. For piloted ignition, factors are around 2.8–1.6, whereas for thermal decomposition, they are 1.3–1.2. The corresponding figures are 1.8–1.3 and 1.3–1.1, in the same order, for the spontaneous ignition. Overall, the effects of the molecular weight are more important than those related to the reaction kinetics environment. These differences are confirmed by the comparison between predictions and measurements. [ABSTRACT FROM AUTHOR]

Focusing on the study of the phase separation behavior of triblock copolymer and linear low-density polyethylene (LLDPE) systems helps to understand the influence of microstructure on the properties of poly(vinylcyclohexane)-b- poly(ethylene)-b-poly(vinylcyclohexane) (PVCH-PE-PVCH/LLDPE) blends. We prepared a series of blends of LLDPE and PVCH-PE-PVCH and explained their compatibility from the microstructure. The research findings indicate that despite having similar block compositions, PVCH-PE-PVCH with a higher molecular weight exhibits significantly stronger phase separation and crystallization ability compared to PVCH-PE-PVCH with lower molecular weight. In PVCH-PE-PVCH/LLDPE blends, the addition of 10 %, 20 %, and 30 % LLDPE induces earlier crystallization and crystal phase separation of polyethylene (PE) fragments. In addition, compared to the lower molecular weight of PVCH-PE-PVCH, the higher molecular weight of PVCH-PE-PVCH exhibits a higher tendency for independent crystallization and shows significant crystal phase separation during the cooling crystallization process when blended with LLDPE. The PE segments in the lower molecular weight of PVCH-PE-PVCH can more easily enter the nanoscale domain of LLDPE. Impact fracture electron microscopy also reveals better compatibility between the lower molecular weight of PVCH-PE-PVCH and LLDPE compared to the higher molecular weight of PVCH-PE-PVCH. Furthermore, the blends of lower molecular weight of PVCH-PE-PVCH and LLDPE exhibit a greater growth rate in elongation at break. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Henan University of Technology Natural Science Edition is the property of Henan University of Technology Journal Editorial Department 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.)

To explore the performance evolution mechanism of SBS-modified bitumen (SMB) during construction and service, the chemical structure, molecular weight and properties of styrene–butadiene–styrene triblock copolymer (SBS) and SMB under multiple aging levels were assessed via Fourier transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC) and a dynamic shear rheometer (DSR). The results indicate that the polybutadiene segments in SBS are susceptible to oxidative degradation, and the molecular weight of SBS decreases rapidly during the aging process. The complex modulus and temperature sensitivity of SMB show relatively small changes during the early aging stage, which is mainly attributed to the impact of SBS oxidative degradation. While its temperature sensitivity decreases sharply after double PAV aging, it means the influence of asphalt aging on its performance is dominant. And there is a significant difference in the effect of aging on the creep recovery behavior of SMB under high and low shear stresses. The percentage recovery (R) of SMB decreases and then increases under low shear stress as aging progresses. While the value R of SMB increases gradually under high shear stress with the extension of aging. Meanwhile, the viscoelastic properties of SMB have gradually transformed to those of aged matrix asphalt after serious aging, which is also confirmed by the gradual destruction and degradation of the SBS cross-linked network in the binder from a fluorescence micrograph. This research will help to understand the performance failure mechanism of SMB during service, providing a theoretical reference for the selection of maintenance and renovation opportunities during the service process of SBS-modified asphalt pavement, as well as the avenue to achieve high-performance recycling. [ABSTRACT FROM AUTHOR]

The purpose of this study is to investigate the use of nucleating agent to improve the overall performance of polybutylene adipate-co-terephthalate (PBAT) and calcium carbonate (CaCO3) composites. Specifically, sodium linoleate (Na-LL) is used as a chemical nucleating agent to improve the crystallization behavior of the material during melting extrusion processing. Mechanical, thermal, and morphological characteristics of PBAT and its composites were investigated. And a preliminary exploration was conducted on the mechanism of Na-LL improving the performance of PBAT. In this work, a formula has been obtained that dramatically saves production costs while improving product performance. After adding Na-LL to the composites, the thermal properties of the material were significantly improved, with a maximum crystallization temperature increase of 27.79 °C. In addition, composites offer superior mechanical properties compared to pure PBAT. When 0.2 parts by mass(pbw) Na-LL was added, the flexural modulus of the composites increased from 80.0 to 145.3 MPa, increased by 81.25%. The tensile performance can still be maintained at 11.0 Mpa, with elongation at break and impact strength reduced to 347.3% and 172.1 J/m, respectively. Under these conditions, it has excellent comprehensive mechanical properties. The results in this study suggest that Na-LL is a promising nucleating agent for enhancing the performance of composites and provides potential development of advanced materials for a wide range of applications in plastic packaging and plastic bags. [ABSTRACT FROM AUTHOR]

We propose that during the evaporation of sessile droplets, the evaporative flux profile is primarily influenced by droplet geometry and composition under diffusion-limited conditions. Most studies have focused solely on the evaporation feature from the liquid to the gas phase, neglecting the extent to which the evaporated vapors affect the evaporation process. We hypothesize that if the molecular weight of the evaporated vapors is significantly high or low compared to the ambient gas, it could alter the evaporative flux. We employed a direct optical measurement technique, specifically Mach-Zehnder interferometry. This demonstrated that the distribution of evaporated vapor molecules can substantially modify the evaporative flux profile. Our study discovered that substantial density gradients between vapor and air could either suppress or enhance the evaporative flux, depending on the droplet's orientation. This research offers fresh insights into evaporative fluxes by taking into account the relative vapor concentration and gravitational effects. • Laser interferometry was employed to accurately gauge the evaporative flux of a sessile droplet both on and underneath a plate. • Accuracy of the interferometric results was validated by comparison with side-view shadowgraphy results. • Both the molecular weight of evaporated vapor and the droplet orientation significantly impact the vapor distribution. • Vapor distribution surrounding droplets can significantly influence the evaporative flux. [ABSTRACT FROM AUTHOR]

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The emulsifying capacity of bovine bone protein extracted using high-pressure hot water (HBBP) has been determined to be good. Nevertheless, given that HBBP is a blend of peptides with a broad range of molecular weights, the distinction in emulsifying capacity between polypeptide components with high and low molecular weights is unclear. Therefore, in this study, HBBP was separated into three molecular weight components of 10–30 kDa (HBBP 1), 5–10 kDa (HBBP 2), and <5 kDa (HBBP 3) via ultrafiltration, and the differences in their structures and emulsifying properties were investigated. The polypeptide with the highest molecular weight displayed the lowest endogenous fluorescence intensity, the least solubility in an aqueous solution, and the highest surface hydrophobicity index. Analysis using laser confocal Raman spectroscopy showed that with an increase in polypeptide molecular weight, the α-helix and β-sheet contents in the secondary structure of the polypeptide molecule increased significantly. Particle size, rheological characteristics, and laser confocal microscopy were used to characterize the emulsion made from peptides of various molecular weights. High-molecular-weight peptides were able to provide a more robust spatial repulsion and thicker interfacial coating in the emulsion, which would make the emulsion more stable. The above results showed that the high-molecular-weight polypeptide in HBBP effectively improved the emulsion stability when forming an emulsion. This study increased the rate at which bovine bone was utilized and provided a theoretical foundation for the use of bovine bone protein as an emulsifier in the food sector. [ABSTRACT FROM AUTHOR]

Polydiacetylenes, as a class of conjugated polymers with alternating conjugated C═C and C≡C bonds, have emerged as a promising probe material for biomedical Raman imaging, given their ultrastrong Raman scattering intensity. However, the relationship between the structure, especially the molecular length of polydiacetylenes, and their Raman scattering intensity remains unclear. In this work, a series of water‐soluble polydiacetylenes, namely poly(deca‐4,6‐diynedioic acid) (PDDA) with different molecular weights (MWs), is prepared through controlled polymerization and degradation. The ultraviolet–visible (UV–vis) absorption spectroscopic and Raman spectroscopic studies on these polymers reveal that the Raman scattering intensity of PDDA increases nonlinearly with the MW. The MW‐Raman scattering intensity relationship in the polymerization process is completely different from that in the degradation process. In contrast, the Raman scattering intensity increases more linearly with the maximal absorbance of the polymer, and the relationship between the Raman scattering intensity and the maximal absorbance of PDDA in the polymerization process is consistent with that in the degradation process. The Raman scattering intensity of PDDA hence exhibits a better dependence on the effective conjugation length of the polymer, which should guide the future design of conjugated polymers for Raman imaging applications. [ABSTRACT FROM AUTHOR]

Chitosan nanoparticles (NPs) have been the subject of intensive research. This study aimed to determine how different drug characteristics such as molecular weights, drug solubility in the processing medium, and drug ionization/charge state affected chitosan NPs particularly their percentage entrapment efficiency (% EE) and mean hydrodynamic diameters (MHDs). Drugs with varying molecular weights but of similar aqueous solubilities were chosen and were dissolved in a 2% chitosan-acetic acid solution. Chitosan NPs were formed using by ionic gelation technique using sodium tripolyphosphate (TPP) at specific concentration and volume ratios of chitosan to TPP. NPs containing Enalapril and Paracetamol displayed better short-term stability in terms of MHDs. A direct relationship between MHDs of NPs and chitosan concentrations was found. In comparison, at both low and high admixed drug concentrations and at high chitosan concentration, larger NPs sizes were associated with the lower molecular weight drug (Paracetamol). However, the study did not demonstrate a direct relationship between NPs characteristics such as MHDs and drugs molecular weights. The ZP of Paracetamol-loaded NPs was lowest at high drug concentrations at all chitosan concentrations compared to other drugs-loaded NPs. When compared to drugs with high and low molecular weights, medium molecular weight Atenolol showed the highest % EE. This clearly indicated that there was no direct correlation between drug molecular weight and % EE, but rather other factors influenced on % EE. Nevertheless, an inverse linear relationship with high correlation coefficients was only found when % EE was plotted against each drug molecular weight divided by the ratio of drugs solubilities in acetic acid to their employed concentrations, however the correlation was inconsistent between drugs of varying molecular weights. [ABSTRACT FROM AUTHOR]

In this work, we have synthesized and characterized a series of Donor−Acceptor (D–A) conjugated polymers (PffBT4T-2DT) with different molecular weights, introduced a microwave method into the synthesis process, shortened the experimental cycle time by over 5 days and increased the molecular weight of the polymers. The conditions affecting the molecular weight of the polymers were investigated. It is shown that the prepared conjugated polymers have excellent thermal stability and solubility, higher molecular weight polymers have broader absorption spectra and stronger inter-chain aggregation, and the strong aggregation ability of polymer chains is dependent on molecular weight and solution temperature, with lower polymer molecular weight and higher solution temperature both causing weaker polymer chain aggregation. The polymer films of the three molecular weights have a uniform surface with a roughness of about 0.83 and good crystallinity. Transistor test results show that the higher molecular weight polymers perform better when applied to field effect transistors, with mobilities as high as 0.124 cm2 V−1 s−1 and threshold voltages as low as 2 V. A series of donor-acceptor conjugated polymers (PffBT4T-2DT) with different molecular weights were synthesized by introducing the microwave method. The thermodynamic, optical, electrochemical and photovoltaic properties of the polymers were characterized, and the effect of molecular weight on the performance of organic field effect transistors (OFETs) was investigated. [ABSTRACT FROM AUTHOR]

Introduction: Rice (Oryza sativa L.) feeds more than half of the world's population. Rice is considered a model plant in biological and agriculture field research due to its small genome compared with other plants. Storage proteins in the aleurone layer of rice seeds include albumin and globulin, as well as the endosperm, prolamin, and glutelin proteins. To determine the number of proteins and identify the protein spots between the tissues of two embryo samples and rice endosperm, the protein spots were matched according to their expression level in the images obtained from two-dimensional gel electrophoresis. Materials and methods: The profile of proteins in the endosperm and embryo of rice seeds was determined using isoelectric focusing (IEF) and polyacrylamide gel electrophoresis(SDS-PAGE) methods. The Image Master software was utilized to analyze the two-dimensional gels. Considering the importance of local rice consumption in Iran and the significant production of this economically important crop in the country, this study aimed to determine the diversity and differences in the expression of protein spots within the linear pH range of 4 to 7. The two-dimensional electrophoresis method was employed on the Hasan-Sarai variety of rice indigenous to the region of Guilan. For this research, the cultivar being examined was procured from the Guilan Rice Research Center. Subsequent stages of the experiment, including sample separation and total protein extraction, were conducted at the Payame Noor University laboratory in Asadabad. Ultimately, the protein samples obtained were sent to the Health Research Institute at the Faculty of Pharmacy, where two-dimensional electrophoresis was carried out using an isoelectric focusing device. Finally, the extracted protein samples were transferred to the Health Research Institute of the Faculty of Pharmacy to perform two-dimensional electrophoresis using an isoelectric focusing device. Results: Based on the results of the two-dimensional gel analysis, a large part of the protein spots are present in the pH range of 4 to 7. The analysis of protein profile based on standard proteins with specific molecular weight and isoelectric point indicates that embryo tissue and endosperm based on isoelectric point and molecular weight showed that 284 protein spots in the embryo and 123 protein spots in endosperm have been identified. Among the identified spots, 57 common protein spots showed increased and decreased expression between the two samples. The presence of remaining protein spots in the two samples showed a significant difference between protein content in the embryo and endosperm. Conclusion: Image master software was used to determine the isoelectric point and molecular weight of protein spots and expression changes between common spots. Analysis was done in protein databases and possible proteins were identified in embryo tissue and endosperm. The proteins identified in rice endosperm and embryo tissue in two-dimensional electrophoresis included grain storage proteins, glutelin precursors, acidic and alkaline glutelins, globulins, prolamins, HSPs, and hypothetical proteins. Therefore, in this way, it is possible to identify the level of expression of proteins and also their biosynthetic pathways. [ABSTRACT FROM AUTHOR]

To clarify the characteristics of compounds with strong or weak nitrification inhibition in sewage, 64 organic compounds including compounds registered in Pollutant Release and Transfer Register (PRTR) were evaluated in terms of their chemical structures and molecular weights. Nineteen compounds showed strong nitrification inhibition by testing with Nitrosomonas europaea. Compounds with thioamide structures had the lowest median value of EC50 (0.017 mg/L), followed by those with alkyne structures (0.121 mg/L), chlorophenol structures (0.300 mg/L), and then azole structures (0.365 mg/L). In contrast, 33 of the 64 compounds showed weak nitrification inhibition at a concentration of 10 mg/L, 27 of which were categorized into three main groups: long-chain alcohol structures, alkyne structures with a phenyl group, and aromatic structures. Most compounds with strong nitrification inhibition had a low molecular weight (MW) from 50 to 200. Meanwhile, the proportion of compounds with weak nitrification inhibition tended to be greater with increasing MW and such compounds were predominant at higher molecular weights above 300. The correlations of results derived from tests of nitrification inhibition based on ISO 9509 and N. europaea showed that 24 out of 30 compounds provided results that were highly correlated between these tests (R = 0.85), while 4 compounds with chlorophenol structures and 2 compounds with alkyne structures showed weaker inhibition rates in the ISO 9509 test than in the N. europaea test. Our results indicate that the magnitude of nitrification inhibition depends on MW in addition to the chemical structure, which is helpful in the search for the cause of nitrification inhibition in wastewater treatment plants. [ABSTRACT FROM AUTHOR]

Countries face exasperating and inclement climate worldwide. Food and feed security could be their paramount life objective. The study aimed to investigate the impact of selenium on the protein content and distribution in different parts of rice. For this purpose, advanced selenium biofortified breeding material developed after generations of breeding efforts was investigated at the field area, rice research institute, Chengdu, China during cropping season 2021–22. The accumulation and distribution of selenium and protein contents were observed in various fractions of selenium-enriched rice (Z3057B) and positive control (727). The correlation studies for selenium and protein quantification leads to the optimization of the breeding material and relevance in virtue. The rice fractions indicated rice embryo retains highest selenium contents, which gradually decreases in succession (other rice parts). The difference in protein content between the embryo and endosperm of Se-enriched rice is significant, while that between embryo and aleurone layer is not obvious. The selenium protein was found with molecular weight of 13.6–122.6 kDa. The protein of each molecular weight is found to bind with selenium, but the binding strength of selenium is negatively correlated with the molecular weight of protein. The 67.5% of the total selenium sticks with protein having molecular weight less than 38.8 kDa. In summary, protein with low molecular weight (13.4 kDa) binds maximum selenium and accounts for highest total protein content (40.76%).

As modern technology evolves, researchers are attempting to discover novel strategies for controlling deadly lung cancer. The use of secondary metabolites from plants as a precursor in the green synthesis of metallic nanoparticles has several advantages over the more common physiochemical synthesis as it includes, low cost, energy efficiency, biocompatibility, and therapeutic value. This review aims to investigate the effects of employing materials made from plant-based synthesis that contain metallic nanoparticles (Ag, Au, CuO, Se, ZnO, Pt, and SnO2) highlighting the advantages of their widespread application in lung cancer treatment of the next-generation. Despite a persisting prejudice about the application of nanotechnological products and medicine. The phytochemicals found in plants that are responsible for nanoparticle bio-reduction include flavones, terpenoids, sugars, ketones, aldehydes, carboxylic acids, and amides. These molecules range in size from small molecules to low molecular weight (MW > 5 000) compounds. Additionally, these plant extract biomolecules serve as a reducing and stabilizing agent, resulting in nanoparticles that are stable and have a regulated form. The focus of this review is on the biomolecule green nanoparticles used in the treatment of lung cancer found in the plant extract, which is thought to be the next generation of futuristic materials.

To study the preservation effect of chitosan coating with different molecular weights on postharvest passion fruit, the "Qinmi No.9" was coated with chitosan of molecular weights of 30, 50, 100, 150 and 200 kDa (1.5%, w/v) to determine the quality of passion fruit during storage. The results showed that chitosan coating with different molecular weights was able to delay the shrinkage and yellowing, reduce the weight loss rate and inhibit the decay of passion fruit. Moreover, chitosan with a larger molecular weight was more conducive to delaying the ripening and senescence of passion fruit, as well as reducing shrinkage, and decay. At the end of storage, the weight loss of fruits coated with 200 kDa chitosan was nearly 10% less than that coated with 30 kDa chitosan, and the fruits coated with 150 and 200 kDa chitosan did not decay. The lower molecular weight (30 and 50 kDa) and higher molecular weight (150 kDa) chitosan were more effective in inhibiting weight loss, total soluble solids and soluble sugar metabolism, and maintaining titratable acid, flavonoid and total phenol contents of fruit during storage. The chitosan with 150 kDa had the best effect in maintaining the vitamin C content, which was 1.12 times higher than the control group at the end of storage. In conclusion, chitosan with different molecular weights was effective to delay senescence, slow down water loss and shrink of passion fruit and maintain the quality, chitosan with 150 kDa was more suitable to maintain the quality of postharvest passion fruit.

Abstract Background Eucommia ulmoides (E. ulmoides) leaves are identified as a new resource of medicine and food homology. In this study, the structural characterization, physicochemical properties, and antioxidant activity of E. ulmoides polysaccharides (EUP) were studied. Results Three components with different molecular weights of 1.51 × 105 Da (EUP1), 3.05 × 104 Da (EUP2) and 1.17 × 105 Da (EUP3) were purified from E. ulmoides leaves. They were composed of l -rhamnose (Rha), d -arabinose (Ara), d -mannose (Man), d-glucose (Glu) and d -galactose (Gal), while EUP2 also contained small amounts of d -xylose (Xyl). Three components all had typical polysaccharides absorption peaks, which may be polysaccharides with β configuration of pyranose structure, and amorphous structure of acid polysaccharides with good thermal stability below 270 ℃. However, the molecular weight, monosaccharide composition and apparent morphology of the three components were different, resulting in a stronger scavenging ability of EUP2 and EUP3 against DPPH and OH free radicals. Conclusion The results will provide a theoretical reference for developing EUP-related foods and drugs. Graphical Abstract

As one of the major fractions of petroleum and/or source rock extracts, asphaltene is commonly characte-rized by complicate molecular structures as well as relatively higher molecular weight (MW). The asphaltene occluded biomarkers have been well introduced to be valuable for geochemical research whilst the actual molecular weight and molecular structures of asphaltene macromolecules studies show value in petroleum exploration and production, laboratory treatments as well as petroleum chemical storage and transportation etc. The structure, molecular weight and related experimental measurement methods of asphaltenes reported in this paper are reviewed, in an attempt to provide a more comprehensive understanding on the molecular structure, molecular weight and physicochemical properties of asphaltenes, so as to provide basic data for applying asphaltene geochemical research in the exploration and development study of conventional and unconventional reservoirs. In view of the different views on the structure and molecular weight of asphaltene molecules, the results are reviewed, the main reasons for the controversy are discussed based on the current status of experimental measurement technology, and the future development trend of related researches is pointed out. The current understanding of the structure of asphaltene macromolecules is mainly based on two completely different models, i.e., the island model and archipelago model. The former suggests that asphaltenes have a single aromatic nucleus and the molecular weight characterized is relatively lower. The latter believes that asphaltenes have multiple aromatic nuclei and the molecular weight characterized is relatively higher. The above two models of asphaltene molecular structure are supported by their own experimental measurement results, among which the evidences of the "island" model mainly come from fluorescence spectroscopy, laser vaporization/laser ionization mass spectrometry (L2MS) analysis and stem from various ionization high-resolution (Fourier transform ion cyclotron resonance mass spectrometry, FT-ICR-MS) analysis technologies. The evidences for the archipelago model mainly come from gas phase permeation measurement, size exclusion chromatography and chemical degradation.

Food antimicrobial peptides are increasingly relevant in the treatment of bacterial infections and have a number of advantages in comparison with drugs: slower emergence of resistance in bacterial strains, high activity against antibiotic films and immunomodulatory properties. The physico-chemical properties causing antimicrobial properties include: cationic charge, hydrophobicity, molecular weight and amino acid sequence. Promising sources of antimicrobial peptides are milk proteins, in particular, cow colostrum proteins. The aim of the work is to extract a peptide from the pepsin hydrolysate of cow colostrum, predict its antimicrobial activity using a bioinformatic approach and confirm its effectiveness in vitro. The molecular mass distribution of the peptide was evaluated by mass spectrometric method. The analysis of mass spectra was carried out using the Mascot program, the Peptide Fingerprint option – using the Protein NCBI database. Microsequencing was performed using a MiSeq sequencer. Modeling of the spatial structure of the isolated peptide was carried out using the Schrodinger Maestro molecular modeling program. The antimicrobial activity of the peptide was studied by the disco-diffusion method on gram-positive and gram-negative bacteria. The peptide has been isolated from the pepsin hydrolysate of cow colostrum, which is absent in the known proteomic bases Protein NCBI and AVPdb and, accordingly, its biological activity and functions have not been studied. The resulting peptide belongs to linear alpha-helical peptides consists of 11 amino acid sequences ANRKLRANKSR with a molecular weight of 8.2 kDa, an isoelectric point at 12.79, a charge of +5 (cationic), hydrophilicity (hydrophobicity) +20.84 Kcal*mol-1. As a result of in vitro studies, it was found that the isolated peptide has antimicrobial activity against E. coli ATCC 25922 and B. subtilis and antimicrobial action against C. albicans.

Dynamic mechanical properties of polymers for biomedical applications are crucial parameters for development and engineering of new medical devices. Here, the time-dependent material behavior is a key factor for durability. Varying the strain rate is a convenient implementation of time-dependency for uniaxial testing. This study investigates time-dependence of Poly(L-Lactide) (PLLA) through uniaxial testing with different strain rates and PLLA with different molecular weight. The results show strain dependence for elongation at break and yield stress, Young’s modulus however is not rate dependent. An increase in elongation at break is also seen with increasing molecular weight of PLLA. Plastic strain increases significantly only for PLLA with an intermediate inherent viscosity. Results show distinct time dependencies regarding strain rate for PLLA with slightly different inherent viscosities. For stent-related mechanical material characteristics, higher molecular weight PLLA seems to be advantageous. This study only considers base materials, although appropriate thermal, mechanical as well as chemical post processing approaches for further adjustment of different properties have already been shown. A combination of the best possible base material and a suitable post-processing should be targeted.

Myeloid cells play key roles in cancer immune suppression and tumor progression. In response to tumor derived factors, circulating monocytes and granulocytes extravasate into the tumor parenchyma where they stimulate angiogenesis, immune suppression and tumor progression. Chemokines, cytokines and interleukins stimulate PI3Kγ-mediated Rap1 activation, leading to conformational changes in integrin α4β1 that promote myeloid cell extravasation and tumor inflammation Here we show that PI3Kγ activates a high molecular weight form of myosin light chain kinase, MLCK210, that promotes myosin-dependent Rap1 GTP loading, leading to integrin α4β1 activation. Genetic or pharmacological inhibition of MLCK210 suppresses integrin α4β1 activation, as well as tumor inflammation and progression. These results demonstrate a critical role for myeloid cell MLCK210 in tumor inflammation and serve as basis for the development of alternative approaches to develop immune oncology therapeutics.

BackgroundPhthalates and bisphenol A (BPA) are endocrine disrupting chemicals used in consumer products, building materials, and food processing and packaging materials. They are associated with adverse health outcomes, especially when exposure occurs during heightened windows of susceptibility.ObjectiveWe evaluated the relationship between housing and dietary characteristics and the concentration of several high-molecular-weight (HMW) phthalate metabolites and BPA in a cohort of Latina adolescents.MethodsWe collected information on recent food consumption and housing characteristics and quantified the concentration of HMW phthalate and BPA metabolites in urine collected at two different time points. We used generalized estimating equations (GEE) to assess predictors of each metabolite.ResultsNo significant associations were observed between housing and dietary characteristics and metabolites of di(2-ethylhexyl) phthalate (DEHP) or BPA. In contrast, higher urinary monobenzyl phthalate (MBzP) concentration was associated with living in a home with vinyl or linoleum flooring (66.7% change, p-value

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.

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.

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.