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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.

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]

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]

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]

BACKGROUND RESULTS CONCLUSION The widespread use of quercetin is limited by its instability, low solubility and poor oral bioavailability. Encapsulation of quercetin using a nanoparticle delivery system is an effective way to overcome these drawbacks.The effect of the molecular weight (Mw) of chitosan (CS) (100, 200, 500 and 1000 kDa) on quercetin‐loaded chitosan nanoparticles (QCNPs) was investigated. The structure, stability, release properties and antioxidant activities of the nanoparticles (QCNP‐10, QCNP‐20, QCNP‐50 and QCNP‐100) were assessed. Particle size of QCNPs decreased and polydispersity index increased with the increasing Mw of CS. The main forces involved in the formation of QCNPs were hydrogen bonding and hydrophobic interaction. X‐ray diffraction verified that quercetin was loaded into CS nanoparticles. The photostability and thermal stability of QCNPs increased with increasing Mw of CS. QCNP‐100 exhibited the lowest release rate in a mixture of water and anhydrous ethanol. The antioxidant activities of QCNPs were enhanced with increasing Mw of CS, and QCNP‐100 possessed the highest antioxidant activities, which might be relevant to its smallest particle size.Overall, these results revealed that the Mw of CS affected the properties of QCNPs, and QCNP‐100 possessed the smallest particle, best stability, lowest release rate and highest antioxidant activities. © 2024 Society of Chemical Industry. [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]

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]

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]

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]

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]

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]

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.)

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.

Objective: This study aimed to investigate the nutrient composition and the optimal enzymatic conditions for the peptides of Aspongopus and lay the groundwork for the creation of Aspongopus protein resources. Methods: The fat, protein, crude polysaccharide content, and fatty acid composition were determined according to the national standard method, and the total flavonoid and polyphenol content was determined by the standard curve method. Response surface methodology was used to optimize the enzymatic process conditions of Aspongopus based on the peptide yield; Amino acid analyzer and high-performance gel permeation chromatography was used to determine the amino acid composition and the relative molecular mass distribution of Aspongopus digest; The scavenging ability of Aspongopus digest of DPPH radicals and ABTS+ radicals as well as the total reducing ability were investigated. Results: Aspongopus crude fat content was 43.40%, and protein content was 37.08%; The contents of total sugar, total flavonoids and total phenols were 7.64%, 1.67%, 1.90% respectively; The optimum enzymatic digestion process of Aspongopus was stewing for 5 h and then digesting for was 6 h at pH 10 and 55 ℃, and the peptide yield was 35.74% under these conditions. The ratio of essential amino acids to non-essential amino acids of Aspongopus digest was 70.46%, the percentage of Aspongopus digest relative molecular mass + clearance rate was 88.44% at the concentration of 1.0 mg/mL of the enzymatic digest of Aspongopus. Conclusion: Under the control of the optimal procession conditions, the peptide yield of Aspongopus was 35.74%, with high nutritional value and good antioxidant activity.

Abstract Background The structural diversity of extracellular polymeric substances produced by microorganisms is attracting particular attention. Poly-gamma-glutamic acid (γ-PGA) is a widely studied extracellular polymeric substance from Bacillus species. The function of γ-PGA varies with its molecular weight (Mw). Results Herein, different endogenous promoters in Bacillus licheniformis were selected to regulate the expression levels of pgdS, resulting in the formation of γ-PGA with Mw values ranging from 1.61 × 103 to 2.03 × 104 kDa. The yields of γ-PGA and exopolysaccharides (EPS) both increased in the pgdS engineered strain with the lowest Mw and viscosity, in which the EPS content was almost tenfold higher than that of the wild-type strain. Subsequently, the compositions of EPS from the pgdS engineered strain also changed. Metabolomics and RT-qPCR further revealed that improving the transportation efficiency of EPS and the regulation of carbon flow of monosaccharide synthesis could affect the EPS yield. Conclusions Here, we present a novel insight that increased pgdS expression led to the degradation of γ-PGA Mw and changes in EPS composition, thereby stimulating EPS and γ-PGA production. The results indicated a close relationship between γ-PGA and EPS in B. licheniformis and provided an effective strategy for the controlled synthesis of extracellular polymeric substances.

Abstract In the present study, low- and high-molecular-weight hyaluronic acids (LMW-HA and HMW-HA) were synthesized in vitro by truncated Streptococcus equisimilis hyaluronan synthases (SeHAS). The enzyme kinetic parameters were determined for each enzyme variant. The MW, structure, dispersity, and biological activity of polymers were determined by electrophoresis, FTIR spectroscopy, carbazole, cell proliferation, and cell migration assay, respectively. The specific activities were calculated as 7.5, 6.8, 4.9, and 2.8 µgHA µgenzyme −1 min−1 for SeHAS, HAS123, HAS23, and HASIntra, respectively. The results revealed SeHAS produced a polydisperse HMW-HA (268 kDa), while HAS123 and HAS23 produced a polydisperse LMW-HA (

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]

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]

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.)

In the present study, low- and high-molecular-weight hyaluronic acids (LMW-HA and HMW-HA) were synthesized in vitro by truncated Streptococcus equisimilis hyaluronan synthases (SeHAS). The enzyme kinetic parameters were determined for each enzyme variant. The MW, structure, dispersity, and biological activity of polymers were determined by electrophoresis, FTIR spectroscopy, carbazole, cell proliferation, and cell migration assay, respectively. The specific activities were calculated as 7.5, 6.8, 4.9, and 2.8 µgHA µgenzyme−1 min−1 for SeHAS, HAS123, HAS23, and HASIntra, respectively. The results revealed SeHAS produced a polydisperse HMW-HA (268 kDa), while HAS123 and HAS23 produced a polydisperse LMW-HA (< 30 kDa). Interestingly, HASIntra produced a low-disperse LMW-HA. Kinetics studies revealed the truncated variants displayed increased Km values for two substrates when compared to the wild-type enzyme. Biological assessments indicated all LMW-HAs showed a dose-dependent proliferation activity on endothelial cells (ECs), whereas HMW-HAs exhibited an inhibitory effect. Also, LMW-HAs had the highest cell migration effect at 10 µg/mL, while at 200 µg/mL, both LMW- and HMW-HAs postponed the healing recovery rate. The study elucidated that the transmembrane domains (TMDs) of SeHAS affect the enzyme kinetics, HA-titer, HA-size, and HA-dispersity. These findings open new insight into the rational engineering of SeHAS to produce size-defined HA. [ABSTRACT FROM AUTHOR]

Background: The structural diversity of extracellular polymeric substances produced by microorganisms is attracting particular attention. Poly-gamma-glutamic acid (γ-PGA) is a widely studied extracellular polymeric substance from Bacillus species. The function of γ-PGA varies with its molecular weight (Mw). Results: Herein, different endogenous promoters in Bacillus licheniformis were selected to regulate the expression levels of pgdS, resulting in the formation of γ-PGA with Mw values ranging from 1.61 × 103 to 2.03 × 104 kDa. The yields of γ-PGA and exopolysaccharides (EPS) both increased in the pgdS engineered strain with the lowest Mw and viscosity, in which the EPS content was almost tenfold higher than that of the wild-type strain. Subsequently, the compositions of EPS from the pgdS engineered strain also changed. Metabolomics and RT-qPCR further revealed that improving the transportation efficiency of EPS and the regulation of carbon flow of monosaccharide synthesis could affect the EPS yield. Conclusions: Here, we present a novel insight that increased pgdS expression led to the degradation of γ-PGA Mw and changes in EPS composition, thereby stimulating EPS and γ-PGA production. The results indicated a close relationship between γ-PGA and EPS in B. licheniformis and provided an effective strategy for the controlled synthesis of extracellular polymeric substances. [ABSTRACT FROM AUTHOR]

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher 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 China Mining Magazine is the property of China Mining Magazine Co., Ltd. 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 Guangdong University of Technology is the property of Journal of Guangdong University of Technology 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.)

Measurement of molecular weight is an integral part of macromolecular and polymer characterization which usually has limitations. Herein, this article presents the use of a bench‐top 80 MHz Nuclear Magnetic Resonance (NMR) spectrometer for diffusion‐ordered spectroscopy as a practical and rapid approach for the determination of molecular weight/size using a novel solvent and polymer‐independent universal calibration. [ABSTRACT FROM AUTHOR]

This study investigated the properties of starch isolated from the unripe fruit of two apple cultivars (Malus domestica Borkh) grown in southern Poland (Central Europe). The chemical composition of both starches, molecular mass, their granulation, thermal characteristics, swelling characteristics, and rheological characteristics were studied. The starches differed significantly in ash, phosphorus, and protein content. The water-binding capacity at temperatures of 25–65 °C was similar, while differences of 20% appeared at higher temperatures. In contrast, a significant difference was found in the solubility of the two starches in the temperature range of 25–75 °C. The study showed that apple starches have a relatively low tendency to retrograde, with the enthalpy of gelatinization for starch from the Oliwka variety being 40% higher than that from the Pyros variety. However, the starches differed in the hardness of the gels formed, i.e., one variety formed soft gels with an internal structure resistant to external forces, while the other formed hard gels. [ABSTRACT FROM AUTHOR]

The impact protection applications of polycarbonate (PC) products are gradually increasing. Due to the high sensitivity of PC to notches, research on notch impacts has become very important. In this paper, the impact performance of PC with two different molecular weights under different notch states was investigated. Three notch size factors, namely notch tip radius, notch angle, and notch center depth, were selected to design orthogonal experiments and research impact toughness. Subsequently, a single-factor study was conducted on the impact radius at the tip of the notch, which was the most important factor affecting the impact performance. Research shows that the brittle–ductile-transition tip radius of high-molecular-weight PC is 0.15 mm, and it has a higher impact toughness than low-molecular-weight PC during the brittle fracture process. The brittle–ductile-transition tip radius of lower molecular weight is 0.25 mm, while low-molecular-weight PC has a higher impact toughness during the ductile fracture process. The brittle and ductile fracture mechanisms of PC with different molecular weights were analyzed by observing the stress changes and cross-sectional morphology. [ABSTRACT FROM AUTHOR]

Biopharmaceutical and biomedical applications of chitosan has evolved exponentially in the past decade, owing to its unique physicochemical properties. However, further applications can be garnered from modified chitosan, specifically, depolymerized chitosan, with potentially useful applications in drug delivery or biomedicine. The use of microwave irradiation in depolymerization of chitosan appears to be more consequential than other methods, and results in modification of key physicochemical properties of chitosan, including molecular weight, viscosity and degree of deacetylation. In-depth review of such microwave-depolymerized chitosan and subsequent potential biopharmaceutical or biomedical applications has not been presented before. Herein, we present a detailed review of key physicochemical changes in chitosan following various depolymerization approaches, with focus on microwave irradiation and how these changes impact relevant biopharmaceutical or biomedical applications. [ABSTRACT FROM AUTHOR]

For various purposes, it is required to compress the shape of the molecular weight distribution (MWD) of polymers into a limited set of parameters. With increasing molecular weight and polydispersity, the MWD data obtained from chromatography become increasingly unreliable due to deficiencies in the high molecular weight region, making estimation via melt rheology more preferable. A number of empirical parameters obtained from melt rheology can be related back to MWD parameters. The target of this study is to establish the reliability of such relations for polypropylene homo‐ and copolymers. It is found that correlations between polydispersity from rheological crossover modulus and polydispersity via chromatography are not always valid. Therefore, the range of applicability must be kept in mind when attempting predictions based on these correlations because rheological measurements are sensitive to molecular characteristics in ways different from chromatography. The use of a modified polydispersity index is shown to be more reliable. [ABSTRACT FROM AUTHOR]

Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) is used to identify protein presence, absence, or overexpression and usually, their interpretation is visual. Some published methods can localize the position of proteins using image analysis on images of SDS-PAGE gels. However, they cannot automatically determine a particular protein band's concentration or molecular weight. In this article, a new methodology to identify the number of samples present in an SDS-PAGE gel and the molecular weight of the recombinant protein is developed. SDS-PAGE images of different concentrations of pure GPN protein were created to produce homogeneous gels. Then, these images were analyzed using the developed methodology called Image Profile Based on Binarized Image Segmentation (IPBBIS). It is based on detecting the maximum intensity values of the analyzed bands and produces the segmentation of images filtered by a binary mask. The IPBBIS was developed to identify the number of samples in an SDS-PAGE gel and the molecular weight of the recombinant protein of interest, with a margin of error of 3.35%. An accuracy of 0.9850521 was achieved for homogeneous gels and 0.91736 for heterogeneous gels of low quality. [ABSTRACT FROM AUTHOR]

Polyacrylic acid (PAA), an organic chemical, has been used as an intermediate in the manufacture of pharmaceuticals and cosmetics. It has been suggested recently that PAA has a high pulmonary inflammatory and fibrotic potential. Although endoplasmic reticulum stress is induced by various external and intracellular stimuli, there have been no reports examining the relationship between PAA-induced lung injury and endoplasmic reticulum stress. F344 rats were intratracheally instilled with dispersed PAA (molecular weight: 269,000) at low (0.5 mg/mL) and high (2.5 mg/mL) doses, and they were sacrificed at 3 days, 1 week, 1 month, 3 months and 6 months after exposure. PAA caused extensive inflammation and fibrotic changes in the lungs' histopathology over a month following instillation. Compared to the control group, the mRNA levels of endoplasmic reticulum stress markers Bip and Chop in BALF were significantly increased in the exposure group. In fluorescent immunostaining, both Bip and Chop exhibited co-localization with macrophages. Intratracheal instillation of PAA induced neutrophil inflammation and fibrosis in the rat lung, suggesting that PAA with molecular weight 269,000 may lead to pulmonary disorder. Furthermore, the presence of endoplasmic reticulum stress in macrophages was suggested to be involved in PAA-induced lung injury. [ABSTRACT FROM AUTHOR]

Copyright of Food & Machinery is the property of Food & Machinery 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.)

Copyright of Modern Food Science & Technology is the property of Editorial Office of Modern Food Science & Technology 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 lactic acid oligomer was synthesized by varying the reaction time and processing it without a catalyst. Gel permeation chromatography (GPC) analysis was carried out to study the molecular weight distribution of lactic acid oligomers at different reaction times (4, 6, 8 and 24 h). The chromatogram of the lactic acid oligomer from 4 to 6 h showed three peaks, while 8 and 24 h showed two. In reaction times of 4 and 6 h, there were peaks from lactide (a cyclic dimer of lactic acid). When the reaction continued for 8 and 24 h, the lactide disappeared. The cyclic structure was cleaved, producing linear dimer lactic acid with an average molecular weight of 179 Da and 171 Da, respectively. The weight average molecular weight of the lactic acid oligomer increases with the reaction time. The highest weight average molecular weight was shown by the reaction time of 24 h, i.e., 680 Da. The 1HNMR and FTIR analyses were conducted to identify the structure of the lactic acid oligomer product. Furthermore, the lactic acid oligomer from the reaction time of 24 h was applied to modify starch. The modified starch was characterized by 1HNMR, FTIR, solubility, and TGA analyses. [ABSTRACT FROM AUTHOR]

By replacing hexyl chains in poly(3-hexylthiophene) (P3HT) with 2-propoxyethyls, four poly(3-(2-propoxyethyl)thiophene) (P3POET) homopolymers with comparable polydispersity indexes (PDI) and regioregularities were prepared herein in addition with step increment of about 7 kDa on number-average molecular weight (Mn) from around 11 to 32 kDa (accordingly denoted as P11k, P18k, P25k, and P32k). When doped in film by FeCl3 at the optimized conditions, the maximum power factor (PFmax) increases greatly from 4.3 µW·m−1·K−2 for P11k to 8.8 µW·m−1·K−2 for P18k, and further to 9.7 µW·m−1·K−2 for P25k, followed by a slight decrease to 9.2 µW·m−1·K−2 for P32k. The close Seebeck coefficients (S) at PFmax are observed in these doped polymer films due to their consistent frontier orbital energy levels and Fermi levels. The main contribution to this PFmax evolution thus comes from the corresponding conductivities (σ). The σ variation of the doped films can be rationally correlated with their microstructure evolution. [ABSTRACT FROM AUTHOR]

Biodegradation rates and mechanical properties of poly(3-hydroxybutyrate) (PHB) composites with green algae and cyanobacteria were investigated for the first time. To the authors knowledge, the addition of microbial biomass led to the biggest observed effect on biodegradation so far. The composites with microbial biomass showed an acceleration of the biodegradation rate and a higher cumulative biodegradation within 132 days compared to PHB or the biomass alone. In order to determine the causes for the faster biodegradation, the molecular weight, the crystallinity, the water uptake, the microbial biomass composition and scanning electron microscope images were assessed. The molecular weight of the PHB in the composites was lower than that of pure PHB while the crystallinity and microbial biomass composition were the same for all samples. A direct correlation of water uptake and crystallinity with biodegradation rate could not be observed. While the degradation of molecular weight of PHB during sample preparation contributed to the improvement of biodegradation, the main reason was attributed to biostimulation by the added biomass. The resulting enhancement of the biodegradation rate appears to be unique in the field of polymer biodegradation. The tensile strength was lowered, elongation at break remained constant and Young's modulus was increased compared to pure PHB. [ABSTRACT FROM AUTHOR]

The creation of anticorrosion hybrid zinc-based coatings containing chitosan particles with low (LMC) or high (HMC) molecular weight is an effective method for safe and durable exploitation of different steel infrastructures. In this work, hybrid coatings consisting of zinc and two types of chitosan particles (LMC or HMC) were obtained to protect low-carbon steel from corrosion attack in a chloride environment. Chitosans with different molecular weights (CS50 Mw 50–190 kDa and CS190 Mw 190–310 kDa) have been applied. Furthermore, both particle types were prepared with or without additional content of incorporated corrosion inhibitor benzotriazole (BTA). The chitosan particles were obtained and thereafter electrodeposited in the form of hybrid coatings on mild steel substrates. The electrokinetic charge and hydrodynamic size of the particles and the stability of their aqueous suspensions were evaluated using dynamic light scattering. The concentration of BTA loaded into the particles was determined by the difference between the initial concentration of the compound added during the particle preparation and the concentration in the supernatant after centrifugation of the dispersion. The hybrid coatings were compared concerning their surface morphology, topography, and hydrophilicity (SEM and AFM analysis, water contact angle measurement) as well as corrosion and electrochemical behavior (potentiodynamic polarization curves—PD, polarization resistance—Rp, cyclic voltammetry—CVA). The protective characteristics of the coatings were studied in 5% NaCl solution. The results obtained from the PD studies demonstrated lower corrosion current densities of all hybrid coatings compared to the ordinary zinc one. In addition, the Rp tests showed enhanced protective ability and corrosion resistance of LMC and LMCB compared to the ordinary zinc, HMC, and HMCB, respectively. The obtained scientific information presented the effect of the molecular weight and ζ-potential of the particles on the anticorrosion ability of the hybrid coatings compared to the ordinary zinc one. [ABSTRACT FROM AUTHOR]

Analytical detection methods play a pivotal role in scientific research, enabling the identification and quantification of specific analytes in various disciplines. This scientific report aims to compare two very different methodologies for determining the Molecular Mass (MM, also known as Molecular Weight, MW) of proteins: electrophoresis gel and the Interferometric Optical Detection Method (IODM). For this purpose, several proteins with different MM were selected.The electrophoresis technique was employed to validate the structure and MM of different parts or fragments of the Matrix Metallopeptidase 9 antibody (anti-MMP9), antibody against S100 calcium binding protein A6 (anti-S100A6) and Cystatin S4 antibody (anti-CST4) by examining the presence of bands with expected sizes. The IODM was applied to study the above-mentioned proteins (part of the antibodies) together with the protein G, as a reference to correlate the MM and protein sizes with the measured signal.We report the evidence of IODM as a competitive analytical approach for the determination of the MM of proteins for the first time. This innovative method allows for accurate MM determination using minimal sample volumes and concentrations, employing a simple experimental procedure that eliminates the requirement for protein denaturation.