Low Molecular Weight Research Articles

Small Peptides: Orchestrators of Plant Growth and Developmental Processes.

Small peptides (SPs), ranging from 5 to 100 amino acids, play integral roles in plants due to their diverse functions. Despite their low abundance and small molecular weight, SPs intricately regulate critical aspects of plant life, including cell division, growth, differentiation, flowering, fruiting, maturation, and stress responses. As vital mediators of intercellular signaling, SPs have garnered significant attention in plant biology research. This comprehensive review delves into SPs' structure, classification, and identification, providing a detailed understanding of their significance. Additionally, we summarize recent findings on the biological functions and signaling pathways of prominent SPs that regulate plant growth and development. This review also offers a perspective on future research directions in peptide signaling pathways.

Repellency, toxicity, and physiological actions of low molecular weight basic amines in mosquitoes.

This study investigated the behavioral responses and toxicity of three basic amines: 1-methylpiperazine, 1-methylpyrrolidine, and triethylamine (TEA), compounds suggested previously to be anosmic in vapor exposures to caged mosquitoes. These compounds showed repellency of Aedes aegypti mosquitoes, followed by flightlessness, knockdown, and paralysis, all increasing with exposure time and dosage. Electrophysiological experiments showed a blocking effect on nerve discharge of the Drosophila melanogaster larval central nervous system (CNS) with little evidence of hyperexcitation. Blockage of voltage-gated (Kv2) potassium channel currents under patch clamp occurred at similar concentrations. Involvement of K+ channels in the action of basic amines was supported by behavior and CNS recordings of a Shaker Kv1 mutant exposed to TEA, where instead of blockage, a hyperexcitation of nerve firing was observed. Experiments on cockroach leg mechanoreceptors demonstrated neuronal excitation and on mosquito antennae strong electroantennogram (EAG) signals with an augmentation of blank air responses after a single puff of basic amine. The neurophysiological effects of basic amines are consistent with K+ channel block, whereas the antennal EAG response was not obviously associated with anosmia. The low-dose effects of basic amines appear to be repellency and bradykinesia. Overall, the findings provide key insights into the mechanisms underlying the biological activity of basic amines. © 2024 Society of Chemical Industry.

Treatment with walnut peptide ameliorates memory impairment in zebrafish and rats: promoting the expression of neurotrophic factors and suppressing oxidative stress.

Walnut peptide, a low molecular weight peptide separated from walnuts by enzymatic hydrolysis, is considered as a potential nutraceutical with a variety of biological activities. In this study, we characterized the walnut peptide prepared by alkaline protease hydrolysis and evaluated its neuroprotective effect in zebrafish and rat models of memory disorders. Series of concentrations of the walnut peptide were orally administered to zebrafish and rats to examine its impact on the behavior and biochemical indicators. The results showed that the oral administration of walnut peptide significantly ameliorated the behavioral performance in zebrafish exposed to bisphenol AF (1 μg mL-1) and rats exposed to alcohol (30% ethanol, 10 mL kg-1). Furthermore, the walnut peptide upregulated the expression of neurotrophic-related molecules in zebrafish, such as the brain-derived neurotrophic factor (BDNF) and the glial cell-derived neurotrophic factor (GDNF). In the rat brain, the walnut peptide increased the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), while dramatically reduced malondialdehyde (MDA) level. Together, these findings elucidated that the walnut peptide might partially offset the declarative memory deficits via regulation of neurotrophic-related molecule expression and promotion of the antioxidant defense ability. Therefore, walnut peptide holds the potential for development into functional foods as a nutritional supplement for the management of certain neurodegenerative disorders.

Pseudomonas aeruginosa Recombinant L-asparaginase: PEGylation with Low Molecular Weight Polyethylene Glycol, Molecular Dynamics Simulation, In vitro and In vivo Serum half-life and Biochemical Characterization.

Microbial L-asparaginase (L-ASNase, EC 3.5.1.1) is a pivotal biopharmaceutical drug-protein that catalyzes the hydrolysis of the non-essential amino acid L-asparagine (L-Asn) into L-aspartic acid (L-Asp) and ammonia , resulting in deplenishing the cellular L-Asn pool, which leads to the ultimate death of the L-asparagine synthetase (L-ASNS) deficient cancerous cells. This study aimed to investigate the impact of conjugating low molecular weight polyethylene glycol to recombinant P. aeruginosa L-ASNase by examining the pharmacokinetic properties, affinity towards the substrate, and enzyme stability prior to and following the reaction. The recombinant P. aeruginosa L-ASNase was affinity purified and then PEGylated by attaching polyethylene glycol (MW= 330 Da) site-specifically to the protein's N-terminus end. After which, the PEGylated L-ASNase was examined by SDS-PAGE (15%), FTIR, and UV/Vis spectrophotometry and subsequently biochemically characterized. The Km and Vmax values of free P. aeruginosa rL-ASNase were determined to be 0.318 ±1.76 mM and 2915 μmol min-1and following the PEGylation, they were found to be 0.396 ±1.736 mM and 3193 μmol min-1, respectively. Polyethylene glycol (330 Da) has markedly enhanced LASNase thermostability at 37, 45, 50, and 55 °C, as opposed to the free enzyme, which retained 19.5% after 1 h of incubation at 37 °C. The PEGylated L-ASNase was found to be stable upon incubation with human serum for 28 h, in contrast to the sharp decline in the residual bioactivity of the free rL-ASNase after 4 h incubation. Accordingly, an in vivo study was used for validation, and it demonstrated that PEGylated rL-ASNase exhibited longer bioactivity for 24 h, while the free form's activity vanished entirely from the rats' blood sera after 8 h. Molecular dynamics simulation indicated that PEG (330 Da) has affected the hydrodynamic volume of L-ASNase and increased its structural stability. Docking analysis has explored the position of PEG with respect to binding sites and predicted a similar binding affinity to that of the free enzyme. For the first time, recombinant L-ASNase was modified by covalently attaching PEG (330 Da). The resultant novel proposed PEGylated rL-ASNase with remarkably increased stability and prolonged in vivo half-life duration, which could be considered an alternative to mitigate the high molecular weight of PEGylation's drawbacks.

Selection of representative molecules of asphalt aromatics based on principal component analysis and hierarchical clustering

ABSTRACT Aromatics constitute the highest proportion among the four asphalt components. The existing literature contains over 20 types of small molecules used to characterise asphalt aromatics, which presents a challenge in constructing asphalt molecular models. In this investigation, quantum chemical calculations were employed to determine the molecular morphology, molecular polarity, and infrared spectrum indicators of asphalt aromatics. Based on principal component analysis and hierarchical clustering, statistical analysis of the aforementioned indicators was conducted to present a recommended scheme for selecting representative molecules of aromatics, thereby reducing the difficulty of constructing asphalt molecular models. The results indicated that N2 was recommended as the representative molecule for aromatics with high molecular weight and long alkane chains, while N3 was recommended as the representative molecule for aromatics with low molecular weight. Based on the variations in substituents of aromatics, it was advisable to select one or more of N7, N10, N14 – N16, and N19 as representative molecules. The investigation guided the selection of aromatic representative molecules in the construction of asphalt molecular models. For major projects with test data, representative molecules could be adjusted according to the test data.

Biodegradable plastics: mechanisms of degradation and generated bio microplastic impact on soil health.

Conventional petroleum-derived polymers are valued for their versatility and are widely used, owing to their characteristics such as cost-effectiveness, diverse physical and chemical qualities, lower molecular weight, and easy processability for large-scale production. However, the extensive accumulation of such plastics leads to serious environmental issues. To combat this existing situation, an alternative lies in the production of bioplastics from natural and renewable sources such as plants, animals, microbes, etc. Bioplastics obtained from renewable sources are compostable and susceptible to degradation caused by microbes hydrolyzing to CO2, CH4, and biomass. Also, certain additives are reinforced into the bioplastic films to improve their physicochemical properties and degradation rate. However, on degradation, the bio-microplastic (BM) produced could have positive as well as negative impact on the soil health. This article thus focuses on the degradation of various fossil based as well as bio based biodegradable plastics such as polyhydroxyalkanoates (PHA), polyhydroxy butyrate (PHB), polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone (PCL), and polysaccharide derived bioplastics by mechanical, thermal, photodegradation and microbial approaches. The degradation mechanism of each approach has been discussed in detailed for different bioplastics. How the incorporation or reinforcement of various additives in the biodegradable plastics effects their degradation rates has also been discussed. In addition to that, the impact of generated bio-microplastic on physicochemical properties of soil such as pH, bulk density, carbon, nitrogen content etc. and biological properties such as on genome of native soil microbes and on plant nutritional health have been discussed in detailed.

Biodegradable plastics: mechanisms of degradation and generated bio microplastic impact on soil health.

Conventional petroleum-derived polymers are valued for their versatility and are widely used, owing to their characteristics such as cost-effectiveness, diverse physical and chemical qualities, lower molecular weight, and easy processability for large-scale production. However, the extensive accumulation of such plastics leads to serious environmental issues. To combat this existing situation, an alternative lies in the production of bioplastics from natural and renewable sources such as plants, animals, microbes, etc. Bioplastics obtained from renewable sources are compostable and susceptible to degradation caused by microbes hydrolyzing to CO2, CH4, and biomass. Also, certain additives are reinforced into the bioplastic films to improve their physicochemical properties and degradation rate. However, on degradation, the bio-microplastic (BM) produced could have positive as well as negative impact on the soil health. This article thus focuses on the degradation of various fossil based as well as bio based biodegradable plastics such as polyhydroxyalkanoates (PHA), polyhydroxy butyrate (PHB), polylactic acid (PLA), polybutylene succinate (PBS), polycaprolactone (PCL), and polysaccharide derived bioplastics by mechanical, thermal, photodegradation and microbial approaches. The degradation mechanism of each approach has been discussed in detailed for different bioplastics. How the incorporation or reinforcement of various additives in the biodegradable plastics effects their degradation rates has also been discussed. In addition to that, the impact of generated bio-microplastic on physicochemical properties of soil such as pH, bulk density, carbon, nitrogen content etc. and biological properties such as on genome of native soil microbes and on plant nutritional health have been discussed in detailed.

Molecular Regulation of Bone Turnover in Juvenile Idiopathic Arthritis: Animal Models, Cellular Features and TNFα.

We review the abnormal bone turnover that is the basis of idiopathic inflammatory or rheumatoid arthritis and bone loss, with emphasis on Tumor Necrosis Factor-alpha (TNFα)-related mechanisms. We review selected data on idiopathic arthritis in juvenile human disease, and discuss mouse models focusing on induction of bone resorbing cells by TNFα and Receptor Activator of Nuclear Factor kappa B Ligand (RANKL). In both humans and animal models, macrophage-derived cells in the joint, particularly in the synovium and periosteum, degrade bone and cartilage. Mouse models of rheumatoid arthritis share with human disease bone resorbing cells and strong relation to TNFα expression. In humans, differences in therapy and prognosis of arthritis vary with age, and results from early intervention for inflammatory cytokines in juvenile patients are particularly interesting. Mechanisms that contribute to inflammatory arthritis reflect, in large part, inflammatory cytokines that play minor roles in normal bone turnover. Changes in inflammatory cytokines, particularly TNFα, are many times larger, and presented in different locations, than cytokines that regulate normal bone turnover. Recent data from in vitro and mouse models include novel mechanisms described in differentiation of bone resorbing cells in inflammatory arthritis dependent on the Transient Receptor Potential Channel (TRPC) family of calcium channels. Low-molecular weight (MW) inhibitors of TRPC channels add to their potential importance. Associations with inflammatory arthritis unrelated to TNFα are briefly summarized as pointing to alternative mechanisms. We suggest that early detection and monoclonal antibodies targeting cytokines mediating disease progression deserves emphasis.

Extraction and Structural Analysis of Sweet Potato Pectin and Characterization of Its Gel.

Pectin is widely used in the food and pharmaceutical industries. However, data on sweet potato pectin extraction and structural property analyses are lacking. Here, for the high-value utilization of agricultural processing waste, sweet potato residue, a byproduct of sweet potato starch processing, was used as raw material. Ammonium oxalate, trisodium citrate, disodium hydrogen phosphate, hydrochloric acid and citric acid were used as extractants for the pectin constituents, among which ammonium oxalate had a high extraction rate of sweet potato pectin, low ash content and high molecular weight. Structural and gelation analyses were conducted on ammonium oxalate-extracted purified sweet potato pectin (AMOP). Analyses showed that AMOP is a rhamnogalacturonan-I-type pectin, with a molecular weight of 192.5 kg/mol. Chemical titration and infrared spectroscopy analysis confirmed that AMOP is a low-ester pectin, and scanning electron and atomic force microscopy demonstrated its linear molecular structure. Gelation studies have revealed that Ca2+ is the key factor for gel formation, and that sucrose significantly enhanced gel hardness. The highest AMOP gel hardness was observed at pH 4, with a Ca2+ concentration of 30 mg/g, pectin concentration of 2%, and sucrose concentration of 40%, reaching 128.87 g. These results provide a foundation for sweet potato pectin production and applications.

Extracorporeal treatment in poisoning

In rare cases, intoxicated patients may require an extracorporeal procedure for enhanced toxin elimination. The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup provides consensus- and evidence-based recommendations regarding the use of extracorporeal procedures in the management of critically ill, poisoned patients, with ongoing updates. Extracorporeal clearance is highest for low molecular weight substances with low volume of distribution, low plasma protein binding, and high water-solubility. To maximize the effect of extracorporeal clearance, blood and dialysate flow rates should be as high as possible, and the membrane with the largest surface area should be utilized. Intermittent hemodialysis is the most commonly employed extracorporeal procedure due to its highest effectiveness, while hemodynamically compromised patients can benefit from acontinuous procedure.

Effects of heat‐moisture treatment on the multiscale structure and digestibility of sweet potato starch

SummaryThe effects of water content on the multi‐scale structure and digestibility of sweet potato starch (SPS) during heat‐moisture treatment (HMT) were studied, and the relationship between water content, starch structure and starch digestibility was analysed. The results showed that the surface of SPS granules changed after HMT, mainly in the form of depression, rupture and adhesion, and the change was more obvious with the increase of water content, and the crystalline structure changed from the original A‐type to A + V‐type. The relative crystallinity and double helix content decreased, the thickness of semi‐crystalline layered structure increased, and the peak intensity decreased. The molecular weight of SPS after HMT tended to be distributed in the low molecular weight range of 4 × 104 g mol−1 < Mw <4 × 105 g mol−1. These structural changes promoted the rearrangement of the intermolecular structure of SPS, which made amylase shield the original action site when acting on SPS, and converted part of rapidly digestible starch (RDS) content into slow digestible starch (SDS) and resistant starch (RS) content, resulting in the increase of SDS and RS content. Especially in HMT‐25, the RS content of SPS was the highest, which was 28.60%. The experimental data can provide theoretical support for broadening the application of SPS.

Extracorporeal treatment in poisoning

In rare cases, intoxicated patients may require an extracorporeal procedure for enhanced toxin elimination. The Extracorporeal Treatments in Poisoning (EXTRIP) workgroup provides consensus- and evidence-based recommendations regarding the use of extracorporeal procedures in the management of critically ill, poisoned patients, with ongoing updates. Extracorporeal clearance is highest for low molecular weight substances with low volume of distribution, low plasma protein binding, and high water-solubility. To maximize the effect of extracorporeal clearance, blood and dialysate flow rates should be as high as possible, and the membrane with the largest surface area should be utilized. Intermittent hemodialysis is the most commonly employed extracorporeal procedure due to its highest effectiveness, while hemodynamically compromised patients can benefit from acontinuous procedure.

Long-Term Prevention of Biofilm Formation by Polycatechol-Based Supramolecular Assemblies with Low Molecular Weight Polymers on Surfaces.

Achievement of a stable surface coating with long-term resistance to biofilm formation remains a challenge. Catechol-based polymerization chemistry and surface deposition are used as tools for surface modification of diverse materials. However, the control of surface deposition of the coating, surface coverage, coating properties, and long-term protection against biofilm formation remain to be solved. We report a new approach based on supramolecular assembly to generate long-acting antibiofilm coating. Here, we utilized catechol chemistry in combination with low molecular weight amphiphilic polymers for the generation of such coatings. Screening studies with diverse low molecular weight (LMW) polymers and different catechols are utilized to identify lead compositions, which resulted in a thick coating with high surface coverage, smoothness, and antibiofilm activity. We have identified that small supramolecular assemblies (∼10 nm) formed from a combination of polydopamine and LMW poly(N-vinyl caprolactam) (PVCL) resulted in relatively thick coating (∼300 nm) with excellent surface coverage in comparison to other polymers and catechol combinations. The coating properties, such as thickness (10-300 nm) and surface hydrophilicity (with water contact angle: 20-60°), are readily controlled. The optimal coating composition showed excellent antibiofilm properties with long-term (>28 days) antibiofilm activity against both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) strains. We further utilized the combination of optimal binary coating with silver to generate a coating with sustained release of silver ions, resulting in killing both adhered and planktonic bacteria and preventing long-term surface bacterial colonization. The new coating method utilizing LMW polymers opens a new avenue for the development of a novel class of thick, long-acting antibiofilm coatings.

Adiponectin and Glucocorticoids Modulate Risk for Preterm Birth: The Healthy Start Study.

Adiponectin is a potent uterine tocolytic that decreases with gestational age, suggesting it could be a maternal metabolic quiescence factor. Maternal stress can influence preterm birth risk, and adiponectin levels may be stress-responsive. We characterized associations between adiponectin and glucocorticoids with preterm birth and modeled their predictive utility. We hypothesized maternal plasma adiponectin and cortisol are inversely related and lower adiponectin and higher cortisol associate with preterm birth. We performed a nested case-control study using biobanked fasting maternal plasma. We included low-risk singleton pregnancies, and matched 1:3 (16 preterm, 46 term). We quantified total, high (HMW), and low molecular weight (LMW) adiponectin using ELISA. We validated an HPLC-MS/MS serum assay for use in plasma, to simultaneously measure cortisol, cortisone, and five related steroid hormones. We used linear/logistic regression to compare group means and machine learning for predictive modeling. The preterm group had lower mean LMW adiponectin (3.07 μg/mL vs. 3.81 μg/mL at 15w0d, P=0.045) and higher mean cortisone (34.4 ng/mL vs. 29.0 ng/mL at 15w0d, P=0.031). The preterm group had lower cortisol-to-cortisone and lower LMW adiponectin-to-cortisol ratios. We found HMW adiponectin, cortisol-to-cortisone ratio, cortisone, maternal height, age, and pre-pregnancy BMI most strongly predicted preterm birth (AUROC=0.8167). In secondary analyses, we assessed biomarker associations with maternal self-reported psychosocial stress. Lower perceived stress associated with a steeper change in cortisone in the term group. Overall, metabolic and stress biomarkers associated with preterm birth in this healthy cohort. We identify a possible mechanistic link between maternal stress and metabolism for pregnancy maintenance.

Adiponectin and Glucocorticoids Modulate Risk for Preterm Birth: The Healthy Start Study.

Adiponectin is a potent uterine tocolytic that decreases with gestational age, suggesting it could be a maternal metabolic quiescence factor. Maternal stress can influence preterm birth risk, and adiponectin levels may be stress-responsive. We characterized associations between adiponectin and glucocorticoids with preterm birth and modeled their predictive utility. We hypothesized maternal plasma adiponectin and cortisol are inversely related and lower adiponectin and higher cortisol associate with preterm birth. We performed a nested case-control study using biobanked fasting maternal plasma. We included low-risk singleton pregnancies, and matched 1:3 (16 preterm, 46 term). We quantified total, high (HMW), and low molecular weight (LMW) adiponectin using ELISA. We validated an HPLC-MS/MS serum assay for use in plasma, to simultaneously measure cortisol, cortisone, and five related steroid hormones. We used linear/logistic regression to compare group means and machine learning for predictive modeling. The preterm group had lower mean LMW adiponectin (3.07 μg/mL vs. 3.81 μg/mL at 15w0d, P=0.045) and higher mean cortisone (34.4 ng/mL vs. 29.0 ng/mL at 15w0d, P=0.031). The preterm group had lower cortisol-to-cortisone and lower LMW adiponectin-to-cortisol ratios. We found HMW adiponectin, cortisol-to-cortisone ratio, cortisone, maternal height, age, and pre-pregnancy BMI most strongly predicted preterm birth (AUROC=0.8167). In secondary analyses, we assessed biomarker associations with maternal self-reported psychosocial stress. Lower perceived stress associated with a steeper change in cortisone in the term group. Overall, metabolic and stress biomarkers associated with preterm birth in this healthy cohort. We identify a possible mechanistic link between maternal stress and metabolism for pregnancy maintenance.

Patient Weight and Chemoprophylaxis in Abdominoplasty: Does It Result in More Bleeding Events?

Bariatric surgery has gained popularity in recent decades as an effective treatment for obesity. Abdominoplasty is one of the most often performed aesthetic procedures all over the world. In post-bariatric patients undergoing abdominoplasty, the diameter size and number of the abdominal wall perforators increase proportionally with increased body weight. Postoperative complications that may occur are haematoma, and venous thromboembolism (VTE). In plastic surgery procedures VTE prophylaxis grades vary due to the lack of consensus and clear guidelines. The aim of this study was to explore the frequency of postoperative bleeding and VTE in patients undergoing abdominoplasty and to explore the risk factors associated with major bleeding. A retrospective single-centre study of adult patients who were operated on by abdominoplasty between 2011 and 2020. Chemoprophylaxis including low molecular weight heparin (LMHW) was recommended when the operating time exceeded 2h. A total of 102 patients were included. There were no patients with VTE. Eight patients were re-operated for major haematoma. The weight loss (peak weight to weight before the abdominoplasty) was 14.4kg larger in the re-operation group (p = 0.03). Eighty-eight percent in the re-operation group and 67% in the other group were treated with LMWH (p = 0.43). Multivariable logistic regression showed that with each decrease from the peak in BMIkg/m2 the risk of re-operation for major haematoma was increased by 22% (p = 0.02). Abdominoplasty in patients after massive weight loss has a higher risk of postoperative bleeding. Having a clear protocol for chemoprophylaxis should be considered. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Patient Weight and Chemoprophylaxis in Abdominoplasty: Does It Result in More Bleeding Events?

Bariatric surgery has gained popularity in recent decades as an effective treatment for obesity. Abdominoplasty is one of the most often performed aesthetic procedures all over the world. In post-bariatric patients undergoing abdominoplasty, the diameter size and number of the abdominal wall perforators increase proportionally with increased body weight. Postoperative complications that may occur are haematoma, and venous thromboembolism (VTE). In plastic surgery procedures VTE prophylaxis grades vary due to the lack of consensus and clear guidelines. The aim of this study was to explore the frequency of postoperative bleeding and VTE in patients undergoing abdominoplasty and to explore the risk factors associated with major bleeding. A retrospective single-centre study of adult patients who were operated on by abdominoplasty between 2011 and 2020. Chemoprophylaxis including low molecular weight heparin (LMHW) was recommended when the operating time exceeded 2h. A total of 102 patients were included. There were no patients with VTE. Eight patients were re-operated for major haematoma. The weight loss (peak weight to weight before the abdominoplasty) was 14.4kg larger in the re-operation group (p = 0.03). Eighty-eight percent in the re-operation group and 67% in the other group were treated with LMWH (p = 0.43). Multivariable logistic regression showed that with each decrease from the peak in BMIkg/m2 the risk of re-operation for major haematoma was increased by 22% (p = 0.02). Abdominoplasty in patients after massive weight loss has a higher risk of postoperative bleeding. Having a clear protocol for chemoprophylaxis should be considered. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Comparative Study of Unfractionated Heparins and Low Molecular Weight Heparin on Skin Wound Repair

Aims: Heparin (HP) has aroused interest in the treatment of skin wounds. The HP extraction sources and the chemical diversity of its structural chain result in different clinical responses. In this study, a comparison was made among the effects of unfractionated heparin from bovine (bovHP) and swine (swi.HP) sources and low molecular weight heparin (LMWH) on skin lesions treatment. Study Design: Wounds were induced on the back of Swiss mice using a punch. Then, the wounds were treated with heparins for 3 and 7 days. Place and Duration of Study: Institute of Biomedical Sciences and Animal Breeding Network and Rodents of the Federal University of Uberlândia, between April 2018 and February 2020. Methodology: Wound closure was performed with a digital caliper. The inflammatory infiltrate was assessed by the activity of neutrophils and macrophages. Angiogenesis was measured by quantifying blood vessels and measuring hemoglobin. While fibrogenesis was assessed by picrosirius red staining. Results: None of the heparins had a healing effect. Swi.HP showed delay in wound closure and intensification of the inflammatory process compared to bov.HP. Swine and bovine heparins showed pro-angiogenic activity, although this did not differ between them. Difference between the groups of heparins was observed in relation to the deposition and organization of collagen fibers, with a reduction in fibrogenesis in wounds of the LMWH group compared to the other heparins, especially bov.HP. A better fibrogenic activity was observed for bov.HP. Conclusion: Thus, we conclude that the source of the heparin used should be considered, as its pharmacological response for wound treatment is quite diverse. Although none of the heparins was able to accelerate wound closure, bov.HP had an anti-inflammatory and pro- fibrogenic effect compared to the other heparins and therefore showed the best response in this experimental model.

Estimating the global root exudate carbon flux

AbstractRoot exudation, the export of low-molecular weight organic carbon (C) from living plant roots to soil, influences microbial activity, nutrient availability, and ecosystem feedbacks to climate change, but the magnitude of this C flux at ecosystem and global scales is largely unknown. Here, we synthesize in situ measurements of root exudation rates and couple those to estimates of fine root biomass to estimate global and biome-level root exudate C fluxes. We estimate a global root exudate flux of 13.4 (10.1–20.2) Pg C y−1, or about 9% (7–14%) of global annual gross primary productivity. We did not find differences in root mass-specific exudation rates among biomes, though total exudate fluxes are estimated to be greatest in grasslands owing to their high density of absorptive root biomass. Our synthesis highlights the global importance of root exudates in the terrestrial C cycle and identifies regions where more in situ measurements are needed to improve future estimates of root exudate C fluxes.

Physicochemical and Rheological Properties of Degraded Konjac Gum by Abalone (Haliotis discus hannai) Viscera Enzyme

In the present study, a new degraded konjac glucomannan (DKGM) was prepared using a crude enzyme from abalone (Haliotis discus hannai) viscera, and its physicochemical properties were investigated. After enzymatic hydrolysis, the viscosity of KGM obviously decreased from 15,500 mPa·s to 398 mPa·s. The rheological properties analysis of KGM and DKGMs revealed that they were pseudoplastic fluids, and pseudoplasticity, viscoelasticity, melting temperature, and gelling temperature significantly decreased after enzymatic hydrolysis, especially for KGM-180 and KGM-240. In addition, the molecular weight of KGM decreased from 1.80 × 106 Da, to 0.45 × 106 Da and the polydispersity index increased from 1.17 to 1.83 after 240 min of degradation time. Compared with natural KGM, the smaller particle size distribution of DKGM further suggests enzyme hydrolysis reduces the aggregation of molecular chains with low molecular weight. FT-IR and FESEM analyses showed that the fragmented KMG chain did not affect the structural characteristics of molecular monomers; however, the dense three-dimensional network microstructure formed by intermolecular interaction changed to fragment microstructure after enzyme hydrolysis. These results revealed that the viscosity and rheological properties of KGM could be controlled and effectively changed using crude enzymes from abalone viscera. This work provides theoretical guidance for the promising application of DKGM in the food industry.