Non-treated Samples Research Articles

Investigating the Effect of Polypyrrole-Gelatin/Silk Fibroin Hydrogel Mediated Pulsed Electrical Stimulation for Skin Regeneration.

In clinical practice to treat complex injuries, the application of electrical stimulation (ES) directly to the skin complicates the wound. In this work, the effect of a conductive hydrogel mediated electric field on skin regeneration is investigated. Polypyrrole incorporated matrices of gelatin and silk fibroin were prepared by two-step interfacial polymerization. The maximum electrical conductivity of 10-4 S cm-1 was achieved when 200 mM polypyrrole was loaded. Mechanically stable and cytocompatible hydrogels were evidenced to have antioxidant and blood compatible characteristics. Human dermal fibroblast cells responded to pulsed stimulation of 100 or 300 mV mm-1 as observed from the increased expressions of TGFβ1, αSMA, and COLIAI genes. Further, the increase in the αSMA protein expression with the magnitude of electrical stimulation also suggested transdifferentiation of the fibroblast to myofibroblast. Moreover, Raman spectroscopy identified two fingerprint regions (collagen and lipid) to differentiate ES treated and nontreated samples. Therefore, the combination of hydrogels and electrical stimulation has potential therapeutic effects for accelerating the rate of skin regeneration.

Assessing the impact of cold plasma rotational dynamics on ginger's total phenolic content, antioxidant activity, surface structure and color using response surface methodology

This study investigated the efficacy of a rotational chamber in enhancing the effectiveness of cold plasma application to augment antioxidant activity and phenolic content in ginger (Zingiber officinale). To address the limitation of cold plasma (CP), which predominantly treats only the surface layers of samples, we implemented rotational techniques during the treatment. This methodology facilitates a more uniform treatment, ensuring that all layers of the samples are effectively exposed to plasma. We employed response surface methodology (RSM) to analyze the effects of three variables: power (10–90 W), treatment time (1–30 min), and pressure (0.4–0.9 mbar), along with a categorical variable for rotation. CP treatment (65 W, 0.7 mbar, 1 min with rotation) resulted in a significant increase in antioxidant activity compared to non-treated samples, determined by 2,2-diphenyl-1-picrylhydrazyl (DPPH), ferric-reducing antioxidant power (FRAP), and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) ABTS assays, and total phenolic content reaching their highest values of 100.9 Trolox equivalent (TE) μmol⋅L−1, 8.23 Fe2+⋅g−1, 0.293 μmol⋅g−1, and 32.80 gallic acid equivalent (GAE)/g, respectively. There were no significant changes in color. Scanning Electron Microscopy (SEM) analysis revealed that the samples treated with CP exhibited a smoother surface, albeit with minimal damage to cell walls in our selected samples. Including a rotational feature as a unique upgrade to the cold plasma, the glow discharge device demonstrated positive enhancements and preservation of antioxidant activity and phenolic compounds.

An investigation into the use of incoherent UV light to augment IR nanosecond pulsed laser texturing of CFRP composites for improved adhesion

The preparation of Carbon Fibre Reinforced Polymers (CFRP) surfaces for adhesive bonding has been widely reported. Such reports include laser texturing using both near-infrared (IR) lasers and ultraviolet (UV) lasers. In this report, we present, for the first time, findings showing that surface treatment of CFRP using incoherent UV light, at 254 nm wavelength, can increase the adhesive bonding strength of CFRP by 75 % compared to non-treated samples. It is also around 10 % stronger than NIR laser-textured samples. However, combination treatments, where the UV irradiation is conducted either before or after laser texturing did not give a significant benefit over the laser-textured samples. A germicidal 46 W 254 nm UV lamp was used for the UV light treatment, while an IR nanosecond pulsed fibre laser operating at 1064 nm was used for the laser texturing treatment. The material tested was an autoclave-cured T700 CFRP composite.The wettability of the treated CFRP surfaces and the adhesive bonding were quantitatively assessed. This study concludes that low-cost incoherent UV treatment effectively reduces the water contact angle of the CFRP surface and activates CFRP surfaces. All treatments led to bonding strengths at least 50% greater than for the untreated surfaces.The predominant failure mode for UV-treated samples was Cohesive Substrate Failure (CSF), indicating that the adhesion strength exceeded the interlaminar shear strength of the CFRP material. All samples treated with the laser (including combined treatment with UV) exhibited Light Fibre Tear Failure.

Physiological and biochemical responses of okra (Abelmoschus esculentus) under salinity stress in Iran

Saline soil and water present significant agricultural challenges, particularly in arid and semi-arid regions like Iran. Around 15 % of Iran's land is categorized as saline. Salt stress disrupts various physiological processes in plants, leading to reduced crop yields. Considering the demand for food and the limitation of cultivated areas is rising, the cultivation of salt-resistant crops is gaining attention. This study was conducted to examine the morpho-physiological responses tolerance of a native cultivar of okra (Abelmoschus esculentus L. cv. White Ahvazi) under conditions of salinity stress. Understanding how this native cultivar responds to salinity stress is crucial for increasing its productivity. The okra seedlings were subjected to seven different levels of electrical conductivity (EC) (1.7 as control, 4.4, 6.2, 8.5, 10.6, 12.5, 14.4, and 15.8 mS/cm) after the appearance of their first true leaves by dissolving NaCl salt in Hoagland's nutrient solution. The results showed that morphological traits in the treated samples were not significantly different from the non-treated samples until EC reached a value of 10.6 mS/cm. The increases in EC from 1.7 to 10.6 mS/cm resulted in a significant rise in the antioxidant capacity and content of biochemical constituents. While salinity stress from EC 12.5 mS/cm onwards caused significant induction of hydrogen peroxide free radicals and peroxidation of membrane lipids. The yield was also significantly reduced at ECs of 12.5, 14.4, and 15.8 mS/cm, which were 31.1, 40.6, and 59.6 % less than control plants, respectively. Increasing salinity stress resulted in a remarkable reduction of photosynthetic pigments in plants as compared to the non-treated plants. Generally, it can be concluded that the White Ahvazi cultivar of okra commonly cultivated in Iran had a moderate tolerance to EC with a threshold of 10.6 mS/cm. Thus, this study can contribute towards enhancing food production in regions facing challenges related to salinity.

The Impact of Tadbir as a Pre-Application Treatment of Medicinal Plants on Their Chemical Profiles and Biological Activities in Traditional Persian Pharmacy

Based on basic traditional medicine practice, many plants undergo primary treatments to improve their pharmacological characteristics or to attenuate unwanted or unfavorable features of drugs before incorporating them into drug formulations. These treatments are called “Tadbir” in Traditional Persian Medicine (TPM). The purpose of these processes includes but is not limited to eliminating unnecessary compounds, excluding harmful properties such as toxicity and poignancy, and improving their overall natural properties and effectiveness. Here, the effect of vinegar and acetic acid treatment on three herbal specimens, including Carum carvi L. fruits (CC), Trachyspermum ammi (L.) Sprague fruits (TA), and Nigella sativa L. seeds (NS) were investigated. The treated and non-treated samples were subjected to essential oil and methanol extraction. Further, to assess the alterations in the essential oil constituents caused by Tadbir, samples were analyzed by Gas Chromatography/Mass Spectrometry (GC/MS) and HPTLC fingerprinting techniques. Total phenol and flavonoid content and DPPH free radical scavenging activity of methanol extracts were evaluated. As a result of the treatments, TA extracts showed significant rise in phenol and flavonoid contents. Total phenol content increased from 98.50±1.01 in non-treated increased to 181.20±0.27 mg GAE/g Ext. in the vinegar-treated TA fruit extract and total flavonoid showed a rise from 8.97±1.12 to 12.89±0.41 mg QE/g Ext. This may be the reason behind its lower IC50 values in DPPH free radical scavenging assay. Interestingly, Tadbir treatment of TA fruits with 4% acetic acid, lowered the IC50 value from 1019.42±75.65µg/mL in non-treated control to 274.2±17.22 µg/mL; while vinegar caused a lower degree of reduction in IC50 value (369.4±5.54 µg/mL) in DPPH free radical scavenging assay. However, CC fruit extracts, showed a decrease in phenolic content; while demonstrating an increase in flavonoids. Interestingly, phenol and flavonoid contents were significantly enhanced in treated NS seed extracts. The results of all extracts were found significantly different (p<0,05) from each other and the non-treated control. The conclusive results of the present study may partly justify the pre-application of Tadbir treatments of medicinal plants in traditional pharmacy.

Genome-wide identification, characterization and functional prediction of the SRS gene family in sesame (Sesamum indicum L.)

Sesame (Sesamum indicum L.) is an ancient oilseed crop of the Pedaliaceae family with high oil content and potential health benefits. SHI RELATED SEQUENCE (SRS) proteins are the transcription factors (TFs) specific to plants that contain RING-like zinc finger domain and are associated with the regulation of several physiological and biochemical processes. They also play vital roles in plant growth and development such as root formation, leaf development, floral development, hormone biosynthesis, signal transduction, and biotic and abiotic stress responses. Nevertheless, the SRS gene family was not reported in sesame yet. In this study, identification, molecular characterization, phylogenetic relationship, cis-acting regulatory elements, protein-protein interaction, syntenic relationship, duplication events and expression pattern of SRS genes were analyzed in S. indicum. We identified total six SiSRS genes on seven different linkage groups in the S. indicum genome by comparing with the other species, including the model plant Arabidopsis thaliana. The SiSRS genes showed variation in their structure like 2–5 exons and 1–4 introns. Like other species, SiSRS proteins also contained ‘RING-like zinc finger’ and ‘LRP1’ domains. Then, the SiSRS genes were clustered into subclasses via phylogenetic analysis with proteins of S. indicum, A. thaliana, and some other plant species. The cis-acting regulatory elements analysis revealed that the promoter region of SiSRS4 (SIN_1011561) showed the highest 13 and 16 elements for light- and phytohormone-responses whereas, SiSRS1 (SIN_1015187) showed the highest 15 elements for stress-response. The ABREs, or ABA-responsive elements, were found in a maximum of 8 copies in the SiSRS3 (SIN 1009100). Moreover, the available RNA-seq based expression of SiSRS genes revealed variation in expression patterns between stress-treated and non-treated samples, especially in drought and salinity conditions in. S. indicum. Two SiSRS genes like SiSRS1 (SIN_1015187) and SiSRS5 (SIN_1021065), also exhibited variable expression patterns between control vs PEG-treated sesame root samples and three SiSRS genes, including SiSRS1 (SIN_1015187), SiSRS2 (SIN_1003328) and SiSRS5 (SIN_1021065) were responsive to salinity treatments. The present outcomes will encourage more research into the gene expression and functionality analysis of SiSRS genes in S. indicum and other related species.

PRESERVATIVE EFFECT OF HERBS AND SPICES ON THE MICROBIAL AND SENSORY QUALITIES OF SCOMBEROMORUS GUTTATUS AND LUTJANUS GIBBUS

In the present study, the effect of natural preservatives on the microbial, biochemical and sensory qualities of economically important marine fishes Scomberomorus guttatus and Lutjanus gibbus were evaluated. Fish fillets were treated with 5% concentration of medicinal herbs rosemary (Rosmarinus officinalis) and thyme (Thymus vulgaris) and spices, ginger (Zingiber officinale - rhizome) and garlic (Allium sativum - bulb). Food spoilage bacterias such as Salmonella typhimurium, Eschericia coli, Staphyloccoccus aureus, Enterobacteriaceae aerogens, Shigella dysenteriae, Pseudomonas aeruginosa, Klebsiella pneumonia, Proteus mirabilis and Streptococcus faecalis were isolated from treated and non-treated samples. The biochemical parameters pH, salt, moisture, protein, carbohydrate and fat contents and sensory qualities such as appearance, odour, flavor, taste and texture of were also tested. The best preservative effect in terms of lowest pH and microbial growth was observed in 5% of Z. officinale extract treated fishes. Next to ginger, thyme was also an efficient in preservation of the fishes compared to control fishes stored at room temperature. Best sensory qualities were recorded in Z. officinale treated cooked fish, which was followed by thyme, garlic and rosemary treated fish fillets.

Electrochemical degradation of diclofenac generates unexpected thyroidogenic transformation products: Implications for environmental risk assessment

Diclofenac (DCF) is an environmentally persistent, nonsteroidal anti-inflammatory drug (NSAID) with thyroid disrupting properties. Electrochemical advanced oxidation processes (eAOPs) can efficiently remove NSAIDs from wastewater. However, eAOPs can generate transformation products (TPs) with unknown chemical and biological characteristics. In this study, DCF was electrochemically degraded using a boron-doped diamond anode. Ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry was used to analyze the TPs of DCF and elucidate its potential degradation pathways. The biological impact of DCF and its TPs was evaluated using the Xenopus Eleutheroembryo Thyroid Assay, employing a transgenic amphibian model to assess thyroid axis activity. As DCF degradation progressed, in vivo thyroid activity transitioned from anti-thyroid in non-treated samples to pro-thyroid in intermediately treated samples, implying the emergence of thyroid-active TPs with distinct modes of action compared to DCF. Molecular docking analysis revealed that certain TPs bind to the thyroid receptor, potentially triggering thyroid hormone-like responses. Moreover, acute toxicity occurred in intermediately degraded samples, indicating the generation of TPs exhibiting higher toxicity than DCF. Both acute toxicity and thyroid effects were mitigated with a prolonged degradation time. This study highlights the importance of integrating in vivo bioassays in the environmental risk assessment of novel degradation processes.

Microwave- and Oven-Heat Moisture Treatment of Broken Rice Flour and the Improvement in Flat Rice Noodle Quality

The characteristics of starch used in the production of rice noodles greatly influenced the product quality. Some rice noodle varieties are made from rice flour, which is typically derived from broken rice grains. Broken rice flour has been associated with a higher level of starch damage that could adversely affect the cooking, textural, and eating qualities of noodles. Hydrothermal treatments have been proposed as a technique for improving starch functionality. This study aims to investigate the effect of different techniques employed in heat moisture treatment (HMT) applied to broken rice (MR263) and their impact on flat rice noodle quality. Rice flour adjusted to 20% moisture content was subjected to two HMT techniques; oven-heat moisture treatment (O-HMT) at 110°C for 3 h and microwave-heat moisture treatment (M-HMT) at 119 W for 5 min. HMT reduced the swelling capacity and solubility of the flour. M-HMT flour had the lowest swelling capacity, whereas O-HMT flour exhibited the lowest solubility. The oven-HMT reduced the L* and whiteness index values of both rice flour and noodles, whereas the microwave-HMT recorded comparable color parameters as the non-treated samples. HMT improved the cooking quality of flat rice noodles, resulting in lower water absorption and cooking loss. Noodles made with oven-treated flour had the lowest cooking loss, whereas the microwave-treated flour resulted in noodles with the lowest water absorption. O-HMT produces noodles with greater improvement in gel texture. Despite the reduced whiteness of the O-HMT noodle, it received higher consumer acceptance in terms of appearance, color, flavor, and hardness. Heat moisture treatment can be used as an economical viable technique for enhancing the quality of flat rice noodles. The varying noodle quality resulting from both oven- and microwave-HMT is attributed to a distinct degree of molecular changes in the starch components, which eventually impact the overall product quality.

Abstract 7246: Enhancing PDAC therapy through in vivo correction of KRAS G12D using enIscB-directed base editor combined with ICB

Abstract In this study, we aim to investigate the therapeutic potential of in vivo genetic therapy using AAV-mediated adenine base editor (ABE) delivery for pancreatic ductal adenocarcinoma (PDAC) carrying the KRASG12D mutation (PDACG12D), and further explore its potential when combined with immune checkpoint blockade (ICB). The KRASG12D mutation is a dominant genetic alteration representing a highly sought-after and effective therapeutic target in PDAC. However, the in vivo genetic therapy for KRASG12D in PDAC has been rarely explored. Programmable base editors have been shown to install genetic mutations precisely and have significant therapeutic value, providing a promising strategy for genetic therapy of PDACG12D. Here, we engineered ABEs derived from various programmable nucleases, considering the protospacer adjacent motif (PAM) or target adjacent motif (TAM) sequence. The hypercompact A8e-enIscB demonstrated the highest editing efficiency in HEK293TG12D and PANC-1 cell lines. Subsequently, A8e-enIscB was packaged into a single-AAV system and delivered to humanized mice subcutaneously transplanted with patient-derived organoidG12D (PDOG12D). We found the delayed tumor progression with BE-based genetic therapy. Additionally, a substantial editing efficiency in tumor tissues and lower off-target editing in normal tissues was observed. By comparing single-cell transcriptome sequencing data between BE-treated and non-treated samples, we observed a reprogrammed immune microenvironment characterized by elevated infiltration of cytotoxic CD8+ T cells and NK cells, as well as decreased recruitment of suppressive PMN-MDSCs, Tregs and TAMs upon correction of KRASG12D. Furthermore, AAV-directed ABE genetic therapy could significantly sensitize PDAC to ICB therapy (anti-PD-1, anti-CTLA4) in humanized PDAC PDO/PDX mouse models. Accordingly, an ongoing work in which the genetic therapy combined with ICB phase IA investigator-initialized trial will be designed to evaluate the safety of this regimen. In summary, our study demonstrates the efficiency and safety of innovative genetic therapy for correcting the KRASG12D mutation in PDAC. Furthermore, we demonstrated the therapeutic potential of combining this genetic therapy with ICB. Citation Format: Chao Yang, Qingxiao Fang, Tianxing Zhou, Yongjie Xie, Jun Yu, Jihui Hao. Enhancing PDAC therapy through in vivo correction of KRAS G12D using enIscB-directed base editor combined with ICB [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 7246.

Fast-setting multi-stimuli responsive silk hydrogels tailored with dual network interface

Silk fibroin, a naturally occurring and versatile polymer with broad range of material forms and applications, presents numerous advantages. Notably, hydrogels are noteworthy among these advantages due to their inherent hydrophilicity, biocompatibility, and flexibility. Nevertheless, their practical utility has been hindered by intricate preparation procedures and limited mechanical strength. In this investigation, we introduce a straightforward and cost-effective method for producing a novel silk hydrogel. Subsequent to the hydrogel synthesis, an ethanol treatment was employed to induce the preferential formation of β-sheet conformations. The developed system exhibits rapid gelation (gelation time: 3 min) and non-swelling behavior (swelling ratio = 0.47). This suggests its potential suitability for biomedical devices without imposing strain on adjacent tissues. Conformational rearrangement of polymeric chains induced by ethanol treatment contributed to heightened material crystallinity, resulting in a remarkable 55.9% increase in Young's modulus and a substantial 91.2% enhancement in ultimate tensile strength for the ethanol-treated hydrogels (SF/AG/Gly/Eth) when compared to their non-ethanol-treated counterparts (SF/AG/Gly). Additionally, in-situ biodegradation studies on silk hydrogels confirmed the material's degradability, with a notable 94.75% weight loss within 3 days, following pseudo-second-order kinetics (R2 = 0.991). This degradation is attributed to action of proteolytic enzymes on the amino acid units of silk fibroin, alleviating concerns regarding waste generation. Moreover, these pH and water-responsive hydrogels can be harnessed in the fabrication of intelligent biomedical devices. Further, drug release studies on silk hydrogels showed that both ethanol-treated and non-treated samples displayed sustained drug release following the Korsmeyer−Peppas model, with an entrapment efficiency of 65.6% and 48.2%, respectively.

Soil-specific outcomes in the OECD 216 Nitrogen Transformation Test.

The Organisation for Economic Co-operation and Development (OECD) 216 test guideline investigates the impact of agrochemicals on soil nitrogen transformation. After an evaluation of 465 OECD 216 studies, we describe two distinct yet contrasting outcomes in control nontreated samples that are possible in this testing framework, which we term the "rise" (consistent increases in nitrate concentrations throughout the test period) and "dip" (initial decline in nitrate concentration between Days 0-7, followed by a net-generation of nitrate across Days 7-28) responses. We raise significant concerns that control data from standardized, internationally recognized test guidelines can demonstrate such dissimilar patterns. We propose that, when present, the dip response undermines the intended functioning of the test system and removes the ability to draw appropriate ecotoxicological inferences from the data. In this work, we hypothesize the dip response is a product of conducting the study in low nitrogen content soils. Our results indicate that the dip response can be alleviated by using ammonium sulfate as an immediately available inorganic nitrogen source in place of the guideline-mandated complex, organic lucerne meal, demonstrating the influence of nitrogen availability and accessibility. However, not all low nitrogen soils exhibited the dip response, indicating the involvement of additional unidentified factors. Using our data and real-world regulatory examples, we advocate that datasets displaying the dip response should not be considered valid OECD 216 studies due to the influence of soil properties precluding an assessment of whether any impacts observed are driven solely by the test compound in question or are instead a product of the soil used. We propose methods to account for these soil-specific responses that could be integrated into the conduct and interpretation of OECD 216 studies. Such amendments will improve the reliability and robustness of the study system and enhance confidence in ecotoxicological conclusions derived from OECD 216 datasets. Integr Environ Assess Manag 2024;20:1611-1624. © 2024 SETAC.

Gamma irradiation and ozone application as preservation methods for longer-term storage of bee pollen

Bee pollen is a healthy product with a good nutritional profile and therapeutic properties. Its high moisture content, however, promotes the growth of bacteria, molds, and yeast during storage commonly result in product degradation. Therefore, the aim of this study is to assess the effectiveness of gamma irradiation (GI) and ozone (OZ) as bee pollen preservation methods for longer storage time, as well as whether they are influenced by pollen species. To do that, GI at a dosage of 2.5, 5.0, and 7.5 kGy was applied at a rate of 0.68 kGy/h and OZ application at a concentration of 0.01, 0.02, and 0.03 g/m3 was applied for one time for 6 h, to Egyptian clover and maize bee pollen, then stored at ambient temperature for 6 months. We then determined the total phenolic content (TPC) and antioxidant activity of treated and non-treated pollen samples at 0, 3, and 6 months of storage. Total bacteria, mold, and yeast count were also evaluated at 0, 2, 4, and 6 months. Statistical analyses revealed that, TPC, antioxidant, and microbial load of both clover and maize pollen samples were significantly (p < 0.05) affected by both treatment and storage time and their interaction. Both methods were extremely effective at preserving the antioxidant properties of pollen samples after 6 months of storage at room temperature. Furthermore, the highest concentrations of both GI and OZ applications completely protected pollen samples from mold and yeast while decreasing bacterial contamination. GI at the highest dose (7.5 KGy) was found to be more effective than other GI doses and OZ application in preserving biologically active compounds and lowering the microbial count of pollen samples for 6 months. As a result, we advise beekeepers to use GI at this dose for longer-term storage.

Evaluation of Low-Pressure Cold Plasma Effect on Phytonutrients, Drying and Microstructural Characteristics, and Changes in Microbial Load of Fresh and Hot-Air-Dried ‘Heidi’ Mango

AbstractAlternative pre-treatment strategies before drying offer the prospect to minimize drying time, replacing the use of chemicals, and preserving quality of dried fresh products. This study explored the application of low-pressure atmospheric cold plasma (CP) for 5- and 10 min (CP5 and CP10) as pre-treatments prior to processing and hot air drying (60 °C) of ‘Heidi’ mango, while non-treated samples served as control. Changes in tissue microstructure and physicochemical properties, bioactive compounds, and microbial load were evaluated, and seven thin layer drying models were applied. Scanned electron microscope images showed that CP pre-treatments altered the tissue microstructure of dried mango slices compared to control. ‘Heidi’ mango slices with the initial moisture content of 80 ± 0.2% on a wet basis was reduced by 81% and 76% in dried CP5 and CP10 samples, respectively. Drying time was reduced by 20% for CP pre-treated samples in comparison to control samples, and the drying behavior of ‘Heidi’ mango slices was best described by the Logarithmic model (R2, 0.9999 and RMSE, 0.0122). Colour attributes were best retained by sodium metabisulphite (SMB) pre-treated samples, followed by CP5 pre-treated, which performed better than CP10 and control (p ≤ 0.05). Highest total flavanols (15.0 ± 0.4 mg CE 100 g−1) and higher total phenolics (1528.2 ± 23.6 mg GA 100 g−1) were found in CP5 pre-treated samples compared to the control (p ≤ 0.05). Lowest antioxidant activities were found in CP10 pre-treated samples compared to the control (p ≤ 0.05). CP-pretreatment and drying resulted in ≥ 2 Log reduction in microbial load on mango slices. These results demonstrate to the role players in mango value addition chain, the potential of low-pressure CP pretreatment in enhancing/maintaining the bioactive compounds, reducing drying time and microbial load.

Effects of plasma treatment on biodegradation of natural and synthetic fibers

This study investigates the application of plasma treatment as a means to enhance biodegradation and modify the structural characteristics of fibrous composites. The methodological component of the study includes the selection of the research object; production of composites; low-temperature plasma treatment, and treatment of biodegradability and mechanical strength of samples. The strengthening of fibers with cellulose leads to a significant improvement in mechanical strength. Such an indicator as mechanical strength increases from 18 to 21 MPa. Treatment of natural fibers with low-temperature plasma led to an increase in mechanical strength from 18 to 25 MPa. Treating reinforced fibers with low-temperature plasma currently results in an even greater enhancement in mechanical strength, increasing from 18 to 29 MPa.The electron microscopy of samples reveals some differences in cell wall microfibrils between plasma-treated and non-treated samples. The non-treated fibres are found to have chips and voids. Meantime, the plasma-treated fibres show structural changes in certain regions which resemble wood charring. Through a comprehensive analysis, this research underscores the substantial impact of plasma treatment on the degradation kinetics and morphological features of cellulose-based composites. The results reveal distinct alterations in the composition and behavior of plasma-treated fibres, signifying a shift towards enhanced biodegradability. The natural fibres examined in this study contained 28–30% lignin, whereas the composites exhibited a lower lignin content of 21–23%. These findings corroborate the inference that plasma treatment induces significant changes in fibre structure, accelerating the biodegradation process by 7 days.

Effects of sample pre-treatments on the analysis of liquid organic manures by visible and near-infrared spectrometry

Proper application of a fertilizer requires precise knowledge of its nutrient composition. In the case of liquid organic manures (LOM), this information is often lacking due to heterogeneous nature of these fertilizers. Published “book values” of nutrient contents present the average from a wide range of possible nutrient characteristics, but usually differ considerably from the concentration in a particular manure. Thus, chemical analyses are recommended before applying the specific LOM. Unfortunately, this is usually too costly and time-intensive in practical farming. On-farm analysis by optical spectrometry in the visible and near-infrared (Vis-NIR) range is considered as an efficient alternative. However, calibration of Vis-NIR spectrometry for LOM is challenging as shown in many studies. One reason is LOMs’ tendency to rapidly segregate into a fuzzy continuum with liquid and solid properties. By separating LOM into well-defined liquid and solid phases and measuring them separately, calibration of Vis-NIR spectrometry might be improved. In this study, the effects of four sample pre-treatment techniques on the prediction accuracy of macronutrients (N, P, K, Mg, Ca, S), micronutrients (B, Mn, Fe, Cu, Zn), dry matter and pH of LOM using visible and near infrared spectrometry were comprehensively investigated. The concentrations were referred either to wet basis or to dry matter basis. For the study, a total of 163 samples, separated in two similar LOM sets (pig, cattle, digestates), were either dried, filtered, or centrifuged and always compared to non-treated samples. The experiments demonstrate that in comparison to raw samples (Ø r2 = 0.85) neither filtering (Ø r2 = 0.76 for filtrates and Ø r2 = 0.71 for filter residues), centrifugation (Ø r2 = 0.59 for supernatants and Ø r2 = 0.79 for pellets), nor drying (Ø r2 = 0.74) revealed to be a helpful preparation step significantly improving prediction results, independent from referring to wet or dry basis concentrations.

Tribocorrosion assessment of low-temperature plasma nitrided super duplex stainless steel

The tribocorrosion of low-temperature plasma nitrided UNS S32750 super duplex stainless steel was investigated according to procedures for passivating materials. Nitrided and non-treated samples were compared through two reciprocating sliding tests in NaCl solution: the continuous test, without significant passive layer growth, and the intermittent one, with repassivation. Open circuit potential and linear polarization resistance (LPR) characterized the electrochemical response. LPR was successfully introduced to evaluate the polarization resistance evolution during the continuous test. Corrosion and mechanical wear components were quantified. The mechanical wear dominated, and nitrided samples showed lower wear volume loss. After the intermittent test, their values were further reduced. Such improvement was explained by the higher load bearing capacity and repassivation ability of the nitrided surfaces.

Effects of redox on the phosphorus removal ability of iron-rich phosphorus sorption materials

Iron-rich phosphorus (P) sorption materials (PSMs) are often used in P removal structures, a best management practice able to sequester dissolved P from surface runoff, subsurface drainage, and wastewater. The use of bottom-upward flow in these structures is of great interest, but it creates an intrinsic complication: the presence of stagnant water between flow events may cause structures to develop anoxic conditions. It is unknown whether the redox sensitivity of iron (Fe), the predominant element in Fe-rich PSMs, will affect P binding under anoxic conditions. Understanding the potential impact of intermittent anoxic conditions on the solubility of previously adsorbed P is imperative for determining the feasibility of the bottom-up flow design. The objective of this research was to investigate the (1) development of anoxic conditions in the presence of Fe-rich PSM and tile drainage, (2) Fe-bound P mobilization and solubility, and (3) changes in P sorption capacity of Fe-rich PSMs after oxic conditions are restored. Three Fe-rich PSMs were tested in batch incubation studies: acid mine drainage residual, Fe-coated alumina, and steel metal shavings. Non-treated and P-treated PSM samples were incubated in biogeochemical reactors for as long as necessary to reach Eh = −200 mV. After incubation, dissolved P concentrations in P-treated samples and non-treated samples were similarly low, indicating stability of P retention of PSMs under anoxic conditions. The P removal ability of non-treated PSMs before and after undergoing incubation was not significantly altered, as determined in flow-through experiments. Potentially harmful trace metals were not detected in the incubated solutions. Our research shows that the development of anoxic conditions does not significantly impact PSMs Fe-bound P dissolution, and the P removal ability of PSMs persists after oxic conditions are reestablished.

UV-C Light Treatment to Extend the Shelf-Life of Paneer (Un-ripened Soft Cheese)

Aim: Application of UV-C light to reduce the post-processing surface contamination and to extend the shelf-life of paneer&#x0D; Study Design: The study was aimed for 3×4 factorial design and the paneer samples were exposed to UV-C light for 60, 120 and 180 seconds and studied for its surface decontamination bymicrobiological studies and effect on sensory properties using 9-point hedonic scale after 3, 6 and 9, days of storage in a refrigerated conditions.&#x0D; Place and Duration of Study: Karnataka Veterinary Animal and Fisheries Sciences University (KVAFSU), Dairy Science College, Mahagaon Cross, Kalaburagi, Karnataka, India&#x0D; Methodology: A standard method was followed for the preparation of paneer. The paneer samples were treated with UV-C light in a UV chamber. Further, the samples were analysed for its Total Bacterial Count (TBC), Yeast and Moulds, and Coliform count, and sensory attributes such as flavour, colour and appearance, body and texture, and overall acceptability on a 9-point hedonic scale. The sensory evaluation of the sample was carried out by a panel of minimum 10 semi-trained judges who are well acquainted with the product features.&#x0D; Results: The effect of varied exposure time of UV-C light and after storage days for a specific period was studied on the level of destruction of microbial-count and effect on the sensory characteristics. There was a significant (P=0.05) difference between the treated and non-treated samples in their microbial-count., and a log scale reduction in the bacterial and yeast and mould count on the surface by the effect of UV-C light was observed. The overall acceptability score for UV-C treated and non-treated sample was 8.36 and 8.10 at 0th day, and 7.02 and 5.65 after 9 days, respectively. Hence, the result was comparable to that of non-treated paneer.&#x0D; Conclusion: The chemical-free and cost-effective UV-C treatment for surface decontamination of microorganisms could be a viable technique to extend the shelf-life of paneer.&#x0D; Recommendation: Combination of other non-thermal techniques with UV-C light and with different packaging method could be studied to enhance the keeping quality.

The response of 316 L steel manufactured by selective laser melting route to high-temperature oxidation behaviour: The role of microstructure modification

The current work examines the effect of 316 L steel's microstructure, which is modified through varying scanning angles with the sample surface (HNS (0°), INS (45°), and VNS (90°)) in the selective laser melting (SLM) method and through surface mechanical attrition treatment (SMAT), on its high-temperature oxidation behaviour (at 600–800 °C) is investigated. We have obtained a deeper understanding of the steel's oxidation behaviour by applying various characterisation techniques. The SMATed steel has a ∼ 1000 μm thick deformed layer containing a gradient microstructure, and its topmost layer contains fine twins and nanograins (∼30 nm). The hardness of this surface is ∼1.65 times the non-treated steel's hardness. All samples follow a parabolic rate law during oxidation. The VNS sample unveils the slowest oxidation rate amid the non-treated samples. SMAT increases the activation energy of oxidation. The distribution of elements across the oxidised samples' cross-section shows discontinuous Cr spreading within the oxide layer on the non-treated samples; however, the deformed samples show uniform distribution. Unlike non-SMATed samples, a minute decline in Cr and Mn content is observed underneath the oxide layer on the SMATed samples, confirming their enhanced outward diffusion. The oxide layer on SMATed samples has more Cr- and Mn-rich oxides. These oxides occupy the grain boundaries of the oxidised non-SMATed surfaces, where the micro-pores and cracks are present. Conversely, oxidised SMATed surfaces display uniform, defect-free Cr- and Mn-rich oxides with finer grains. Moreover, the SMATed layer remains reasonably stable during high-temperature oxidation (hardness drop ranges between ∼9 and ∼ 30%).