Fiber Diameter Research Articles

Extraction and characterization of Bougainvillea glabra fibers: A study on chemical, physical, mechanical and morphological properties

Bougainvillea glabra fibers (BGFs) present a promising avenue for sustainable material development owing to their abundance and favorable properties. This study entails a thorough investigation into the composition, physical characteristics, mechanical behavior, structural properties, thermal stability, and hydrothermal absorption behavior of BGFs. Chemical analysis reveals the predominant presence of cellulose (68.92 %), accompanied by notable proportions of hemicellulose (12.64 %), lignin (9.56 %), wax (3.72 %), moisture (11.78 %), and ash (1.75 %). Physical measurements ascertain a mean fiber diameter of approximately 232.63 ± 8.59 μm, while tensile testing demonstrates exceptional strength, with stress values ranging from 120 ± 18.26 MPa to a maximum of 770 ± 23.19 MPa at varying strains. X-ray diffraction (XRD) elucidates a crystalline index (CI) of 68.17 % and a crystallite size (CS) of 9.42 nm, indicative of a well-defined crystalline structure within the fibers. Fourier-transform infrared spectroscopy (FTIR) confirms the presence of characteristic functional groups associated with cellulose, hemicellulose, wax, and water content. Thermogravimetric analysis (TGA) delineates distinct thermal degradation stages, with onset temperatures ranging from 102.76 °C for water loss to 567.55 °C for ash formation. Furthermore, hydrothermal absorption behavior exhibits temperature and time-dependent trends, with absorption percentages ranging from 15.26 % to 32.19 % at temperatures between 30 °C and 108 °C and varying exposure durations. These comprehensive findings provide essential insights into the properties and potential applications of BGFs in diverse fields such as bio-composites, textiles, and environmentally friendly packaging solutions.

Multi-omics reveals the molecular mechanism of muscle quality changes in common carp (Cyprinus carpio) under two aquaculture systems

Preliminary experiments in our laboratory have demonstrated that common carp (Cyprinus carpio) cultivated for two months in land-based container recirculating aquaculture systems (C-RAS) exhibit superior muscle quality compared to those raised in traditional pond systems (TP). To elucidate the molecular mechanisms underlying muscle quality variations in common carp cultured under two aquaculture systems, transcriptomic and metabolomic analyses were performed on muscle tissues of specimens aged 11 to 23 months. Comparison of muscle histological sections between the two groups indicated a significantly lower long diameter of muscle fibers in the C-RAS group compared to the TP group (P < 0.01). Conversely, the muscle fiber density was significantly higher in the C-RAS group than in the TP group (P < 0.05). Transcriptomic and metabolomic analyses identified 3390 differentially expressed genes (DEGs)—1558 upregulated and 1832 downregulated—and 181 differentially expressed metabolites (DEMs)—124 upregulated and 57 downregulated—between the groups. Based on integrated transcriptomic and metabolomic analyses, the significant differences focus on metabolic pathways involving glycolysis/gluconeogenesis, arginine and proline metabolism, arginine biosynthesis, and purine metabolism. The study revealed that the muscle quality of common carp in two aquaculture systems is primarily regulated through improvements in energy metabolism, amino acid metabolism, fatty acid metabolism, and purine metabolism. These metabolic processes play significant roles in promoting muscle fiber hyperplasia and hypertrophy, enhancing muscle flavor, and increasing muscle antioxidant capacity. This study provides new insights into the molecular and metabolic pathways that control muscle quality in common carp under different environmental factors.

Comparison of meat quality, muscle-fibre characteristics and the Sirt1/AMPK/PGC-1α pathway in different breeds of pigs

Context Muscle fibre characteristics are important internal factors that can directly affect pork quality. Especially muscle-fibre types can interconvert with the influence of certain factors. Aims The purpose of this experiment was to study the differences in meat quality among Songliao black pigs, Jilin Hua pigs and Dongliao black pigs, and the molecular mechanism of the differences. Methods First, the conventional meat-quality traits of each breed were determined. Second, the muscle-fibre characteristics of different muscles were analysed by the haematoxylin–eosin staining and immunohistochemistry. Next, the activity of several key oxidative/glycolytic enzymes was detected with kits. Finally, quantitative polymerase chain reaction was used to analyse the expression abundance of myosin heavy-chain (MyHC) genes and key genes related to muscle fibre-type transformation. Key results The results of meat-quality measurement showed that Songliao black pigs were superior to Jilin Hua pigs and Dongliao black pigs in water-holding capacity, tenderness and intra-muscular fat; and Jilin Hua pigs were superior to Dongliao black pigs in water-holding capacity. The diameter and area of muscle fibres were the smallest, the density was the largest, the proportion of oxidative muscle fibres, oxidative enzyme activity and expression abundance of oxidative genes were the highest in Songliao black pigs, followed by Jilin Hua pigs and Dongliao black pigs. The proportions of oxidative muscle fibres ranged from 10.37% to 33.6% in Songliao black pigs, from 6.96% to 26.42% in Jilin Hua pigs, and from 5.86% to 17.42% in Dongliao black pigs. The psoas major exhibited the smallest muscle-fibre diameter, the highest density, followed by triceps brachii, biceps femoris and longissimus thoracis. The oxidative muscle fibre proportions of the psoas major and triceps brachii were significantly greater than those of the biceps femoris and longissimus thoracis. The expression abundances of AMP-activated protein kinase (AMPK), silencing information regulator 1 (SIRT1) and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) (Sirt1/AMPK/PGC-1α) pathway and mitochondrial function-related genes were the highest in Songliao black pigs, followed by Jilin Hua pigs and Dongliao black pigs. Conclusions The results showed that Songliao black pigs had the best meat quality, followed by Jilin Hua pigs and Dongliao black pigs. The meat quality of psoas major and triceps brachii was significantly greater than that of biceps femoris and longissimus thoracis. This experiment suggests that transformation of oxidative muscle fibres can be promoted through the Sirt1/AMPK/PGC-1α pathway. Implications By analysing the meat-quality traits and the molecular mechanism of meat-quality differences, it can provide data reference and direction for further meat-quality improvement of three breed pigs.

Electrospun Ibuprofen-Loaded Blend PCL/PEO Fibers for Topical Drug Delivery Applications.

Electrospun drug-eluting fibers have demonstrated potentials in topical drug delivery applications, where drug releases can be modulated by polymer fiber compositions. In this study, blend fibers of polycaprolactone (PCL) and polyethylene oxide (PEO) at various compositions were electrospun from 10 wt% of polymer solutions to encapsulate a model drug of ibuprofen (IBP). The results showed that the average polymer solution viscosities determined the electrospinning parameters and the resulting average fiber diameters. Increasing PEO contents in the blend PCL/PEO fibers decreased the average elastic moduli, the average tensile strength, and the average fracture strains, where IBP exhibited a plasticizing effect in the blend PCL/PEO fibers. Increasing PEO contents in the blend PCL/PEO fibers promoted the surface wettability of the fibers. The in vitro release of IBP suggested a transition from a gradual release to a fast release when increasing PEO contents in the blend PCL/PEO fibers up to 120 min. The in vitro viability of blend PCL/PEO fibers using MTT assays showed that the fibers were compatible with MEF-3T3 fibroblasts. In conclusion, our results explained the scientific correlations between the solution properties and the physicomechanical properties of electrospun fibers. These blend PCL/PEO fibers, having the ability to modulate IBP release, are suitable for topical drug delivery applications.

Electrospun amygdalin and Inula helenium extract-loaded polylactic acid (PLA)/Polyvinylpyrrolidone (PVP) nanofibrous patches for colon cancer treatment: Fabrication, characterization and antitumour effect results

In this study, 75PLA/25PVP nanofibrous loaded with amygdalin (AMG) and Inula helenium (I.H) extract were produced by electrospinning method in order to prevent local colon cancer recurrence, and the effect of the produced nanofibrous on the HCT-116 cell line was examined in vitro. When the scanning electron microscopy (SEM) images were examined, the fiber diameter of the 75PLA/25PVP group was measured as 443.74 ± 79 nm, but the addition of I.H and AMG caused a thickening effect on the fiber diameters. Drug release results show the controlled release period of 75PLA/25PVP/I.H and 75PLA/25PVP/AMG loaded nanofibrous patches within 180 h. Slowly degrading nanofibrous remained durable for up to 25 days. When the in vitro cytotoxicity results were analyzed, all nanofibrous were found to be effective in inducing cytotoxicity against HCT-116 colon cancer cells. The most effective group is the group in which I.H extract and AMG drug are loaded onto the nanofibrous together. AMG drug and I.H plant extract showed effects on the colon cancer cell line in in vitro experiments. Considering all the results I.H and AMG loaded nanofibrous can be implanted into solid tumor cells in order to reduce the risk of local recurrence of cancer after surgery in colon cancer.

Engineering PTS-based glucose metabolism for efficient biosynthesis of bacterial cellulose by Komagataeibacter xylinus

Bacterial cellulose (BC) is a renewable biomaterial that has attracted significant attention due to its excellent properties and wide applications. Komagataeibacter xylinus CGMCC 2955 is an important BC-producing strain. It primarily produces BC from glucose while simultaneously generating gluconic acid as a by-product, which acidifies the medium and inhibits BC synthesis. To enhance glucose uptake and BC synthesis, we reconstructed the phosphoenolpyruvate-dependent glucose phosphotransferase system (PTSGlc) and strengthened glycolysis by introducing heterologous genes, resulting in a recombinant strain (GX08PTS03; Δgcd::ptsHIcrrE. coli::ptsGE. coli::pfkAE. coli). Strain GX08PTS03 efficiently utilized glucose for BC production without accumulating gluconic acid. Subsequently, the fermentation process was systematically optimized. Under optimal conditions, strain GX08PTS03 produced 7.74 g/L of BC after 6 days of static fermentation, with a BC yield of 0.39 g/g glucose, which were 87.41 % and 77.27 % higher than those of the wild-type strain, respectively. The BC produced by strain GX08PTS03 exhibited a longer fiber diameter along with a lower porosity, significantly higher solid content, crystallinity, tensile strength, and Young's modulus. This study is novel in reporting that the engineered PTSGlc-based glucose metabolism could effectively enhance the production and properties of BC, providing a future outlook for the biopolymer industry.

Nanofibers loaded levosalbutamol sulfate fast dissolving oral films for sublingual delivery

During allergic reactions, a drug should work quickly and effectively. Levosalbutamol (LSAL) is a short-acting drug that stimulates β2 adrenergic receptors and is commonly used to treat asthma and chronic obstructive pulmonary disease (COPD). This study aimed to prepare sublingual oral patches of levosalbutamol sulfate electrospun nanofibers for ultrafast release. In this study, we fabricated nanofibers by electrospinning polyvinyl alcohol (PVA) polymer (10 %) and different concentrations (3, 5, and 10 %) of LSAL. The nanofibers are randomly aligned, with smooth surfaces and an average fiber diameter of 160, 170, and 198 nm at PVA/LSAL concentrations of 3 %, 5 %, and 10 %, respectively. The in vitro dissolution study showed that all PVA/LSAL nanofibers released the drug ultra-fast (within 5–10 min); 90 % released within 3 min. The folding endurance study revealed that the drug-loaded nanofibers had improved stability. A disintegration study showed that the nanofibers disintegrated rapidly in 1–3 min, and an in vitro cytocompatibility study showed good cell viability with A549 human lung cells. Hence, the proposed fast-dissolving sublingual oral films/patches approach is a promising alternative to existing dosage forms. They can provide an ultra-fast release of various drugs requiring a fast onset of action with increased bioavailability and patient compliance.

Centrifugally spun hydroxyapatite/carbon composite nanofiber scaffolds for bone tissue engineering

In recent years, advancements in tissue engineering have demonstrated the potential to expedite bone matrix formation, leading to shorter recovery times and decreased clinical challenges compared to conventional methods. Therefore, this study aims to develop composite carbon nanofibers (CNFs) integrated with nano-hydroxyapatite (nHA) particles as scaffolds for bone tissue engineering applications. A key strategy in achieving this objective involves harnessing nanofibrous structures, which offer a high surface area, coupled with nHA particles expected to accelerate bone regeneration and enhance biological activity. To realize this, polyacrylonitrile (PAN)/nHA nanofibers were fabricated using the centrifugal spinning (C-Spin) technique and subsequently carbonized to yield CNF/nHA composite structures. Scanning Electron Microscopy (SEM) confirmed C-Spin as a suitable method for PAN and CNF nanofiber production, with nHA particles uniformly dispersed throughout the nanofibrous structure. Carbonization resulted in reduced fiber diameter due to thermal decomposition and shrinkage of PAN molecules during the process. Furthermore, the incorporation of nHA particles into PAN lowered the stabilization temperature (by 5 °C–20 °C). Tensile tests revealed that PAN samples experienced an approximately 80% increase in ultimate tensile strength and a 187% increase in modulus with a 5 wt.% nHA loading. However, following carbonization, CNF samples exhibited a 50% decrease in strength compared to PAN samples. Additionally, the addition of nHA into CNF improved the graphitic structure. The incorporation of nHA particles into the spinning solution represents a viable strategy for enhancing CNF bioactivity.

Development of Hybrid Electrospun Nanofibers: Improving Effects of Cellulose Nanofibers (CNFs) on Electrospinnability of Gelatin.

Cellulose nanofibers (CNFs) were used to improve the electrospinnability of the gelatin protein in a water/ethanol/acetic acid (3:2:3, v/v) solution. The effects of different concentrations of CNFs (0.5-4%) on the important physical properties of the gelatin solution (15%), including rheology, conductivity, and surface tension, were investigated. The apparent viscosity and shear-thinning behavior were increased by increasing the CNF concentration from 0 to 4% at a low shear rate (<10 s-1). CNFs also increased the electrical conductivity and surface tension of the gelatin solution. Scanning electron microscopy (SEM) images revealed uniformly ordered structures with good continuity without fracture or bead formation in all hybrid nanofibers. They also showed that the average diameters of fibers decreased from 216 nm in the pure gelatin nanofibers to 175.39 nm in the hybrid gelatin/CNF (4%) ones. Differential scanning calorimetry (DSC) results showed that CNFs increased Tg, and X-ray diffraction (XRD) analysis showed that the electrospinning process caused the formation of more amorphous structures in the gelatin/CNF hybrid nanofibers. The tensile test indicated that by adding 2% CNFs, the ultimate tensile strength (UTS) and strain at break (SB) of nanofiber mats increased from 4.26 to 10.5 MPa and 3.3% to 6.25%, respectively. The current study indicated that incorporating CNFs at the optimal concentration into a gelatin solution can improve the resulting hybrid nanofibers' morphology, average diameter, and mechanical properties.

Electrospun polysuccinimide scaffolds containing different salts as potential wound dressing material.

In this research, we applied electrospinning to create a two-component biodegradable polymeric scaffold containing polysuccinimide (PSI) and antibacterial salts. Antibacterial agents for therapeutical purposes mostly contain silver ions which are associated with high environmental impact and, in some cases, may cause undesired immune reactions. In our work, we prepared nanofibrous systems containing antibacterial and tissue-regenerating salts of zinc acetate or strontium nitrate in different concentrations, whose structures may be suitable for developing biomedical wound dressing systems in the future. Several experiments have been conducted to optimize the physicochemical, mechanical, and biological properties of the scaffolds developed for application as wound dressings. The scaffold systems obtained by PSI synthesis, salt addition, and fiber formation were first investigated by scanning electron microscopy. In almost all cases, different salts caused a decrease in the fiber diameter of PSI polymer-based systems (<500 nm). Fourier-transform infrared spectroscopy was applied to verify the presence of salts in the scaffolds and to determine the interaction between the salt and the polymer. Another analysis, energy-dispersive X-ray spectroscopy, was carried out to determine strontium and zinc atoms in the scaffolds. Our result showed that the salts influence the mechanical properties of the polymer scaffold, both in terms of specific load capacity and relative elongation values. According to the dissolution experiments, the whole amount of strontium nitrate was dissolved from the scaffold in 8 h; however, only 50% of the zinc acetate was dissolved. In addition, antibacterial activity tests were performed with four different bacterial strains relevant to skin surface injuries, leading to the appearance of inhibition zones around the scaffold discs in most cases. We also investigated the potential cytotoxicity of the scaffolds on human tumorous and healthy cells. Except for the ones containing zinc acetate salt, the scaffolds are not cytotoxic to either tumor or healthy cells.

Gingerol containing polymeric nanofibers: a healing touch for accelerated wound recovery

Objective In the current research, 6-gingerol (GA)-loaded nanofiber drug delivery system were developed, and their potential usage in wound healing was evaluated. Significance This study investigates the effectiveness of nanofibrous membranes composed of sodium alginate (SA), poly(vinyl alcohol) (PVA), and 6-gingerol (GA) as delivery systems for anti-inflammatory agents in the context of wound dressings. Methods GA-loaded SA/PVA nanofiber was prepared using electrospinning. In vitro characterization of this nanofiber included the examination of comprehensive in vitro characterization, anti-inflammatory and antioxidant activities, cytotoxicity, a scratch tes and in vivo skin test. Results GA was extracted from Zingiber officinale, and its successful isolation was confirmed through analyses such as H-NMR, C-NMR. Then GA was electrospuned into the SA/PVA nanofibers, and scanning electron microscopy (SEM) imaging revealed that the fiber diameters of the formulations ranged between 148 nm and 176 nm. Anti-inflammatory and antioxidant studies demonstrated that the effectiveness of GA increased with higher doses; however, this increase was accompanied by decreased cell viability. In vitro release studies revealed that GA exhibited a burst release within the first 8 h, followed by a controlled release, reaching completion within 24 h. Within the scope of in vitro release kinetics, release data are mathematically compatible with the Weibull model with high correlation. The scratch test results indicated that TB2 (%1 GA) promoted epithelialization. Furthermore, it was determined that TB2 (%1 GA) did not cause any irritation. Conclusions As a result, TB2 shows promise as a formulation for wound dressings, offering potential benefits in the field of wound care.

Direction-Finding Study of a 1.7 mm Diameter Towed Hydrophone Array Based on UWFBG.

This paper investigates a 1.7 mm diameter ultra-weak fiber Bragg grating (UWFBG) hydrophone towed array cable for acoustic direction finding. The mechanism of the underwater acoustic waves received by this integrated-coating sensitizing optical cable is deduced, and it is shown that the amplitude of its response varies with the direction of the sound wave. An anechoic pool experiment is carried out to test the performance of such a hydrophone array. The test array is a selection of six sensing fibers, each of which is coiled into 9 cm diameter fiber ring suspended in the water to receive acoustic signals. An average sensitivity of -141.2 dB re rad/μPa at frequencies from 2.5 kHz to 6.3 kHz was achieved, validating the detection of the azimuth of underwater acoustic waves. The ultra-thin towing cable system, with free structure, high sensitivity, and underwater target-detection capability has demonstrated great potential for future unmanned underwater vehicle (UUV) applications.

Examining across year genotype by environment interactions for production and reproduction traits in Merino sheep

Variation in feed resource availability within production systems can cause genotype by environment interactions that change the ranking of the best animals to select between environments. Mediterranean environments have high variation in pasture growth between years that could cause genetic by environment interactions for sheep production traits. Therefore, we estimated heritabilities for live weight, fleece weight, fibre diameter and number of lambs weaned in six years from 2000 to 2005 and correlations between years comparing multivariate analysis and random regression analysis. We compared 3 methods: 1 multivariate analysis estimating (co)variances for traits in each year, 2 Random regression estimated (co)variances for intercept and slope for traits as repeated measurements fitted against average pasture growth in each year and 3. Random regression fitted against corrected average performance of animals in each year. Random regression was estimated with an order of polynomial of one for additive genetic variance and zero for permanent environmental effects. This combination of polynomials was the best fit based on Bayesian information criterion. We estimated heritabilities for each year and correlations between years using records from 3299 pedigreed Merino ewes managed at Katanning in Western Australia. There were 4651 records for adult live weight, 6750 for adult clean fleece weight, 6965 for adult fibre diameter, and 7774 for number of lambs weaned across all 6 years. Number of lambs weaned had more genotype by environment interactions than other traits, with fibre diameter and fleece weight having genotype by environment interactions between only a few years. Based on Bayesian information criterion values, multivariate analysis fit the data better for live weight, fleece weight and fibre diameter. Additionally, random regression estimated higher genetic correlations between years than multivariate analysis suggesting there was not enough flexibility in the random regression analysis, which used only first order polynomials, to fit differences between years. Pasture growth across years did not explain differences in performance for traits across years. Therefore, for number of lambs weaned, random regression using corrected average performance was a better fit than average pasture growth. For other traits, more years or a better indicator of variation in performance within and between years are required to use random regression for genotype by environment interactions.

Exploring single-shot propagation and speckle based phase recovery techniques for object thickness estimation by using a polychromatic X-ray laboratory source.

Propagation and speckle-based techniques allow reconstruction of the phase of an X-ray beam with a simple experimental setup. Furthermore, their implementation is feasible using low-coherence laboratory X-ray sources. We investigate different approaches to include X-ray polychromaticity for sample thickness recovery using such techniques. Single-shot Paganin (PT) and Arhatari (AT) propagation-based and speckle-based (ST) techniques are considered. The radiation beam polychromaticity is addressed using three different averaging approaches. The emission-detection process is considered for modulating the X-ray beam spectrum. Reconstructed thickness of three nylon-6 fibers with diameters in the millimeter-range, placed at various object-detector distances are analyzed. In addition, the thickness of an in-house made breast phantom is recovered by using multi-material Paganin's technique (MPT) and compared with micro-CT data. The best quantitative result is obtained for the PT and ST combined with sample thickness averaging (TA) approach that involves individual thickness recovery for each X-ray spectral component and the smallest considered object-detector distance. The error in the recovered fiber diameters for both techniques is , despite the higher noise level in ST images. All cases provide estimates of fiber diameter ratios with an error of 3% with respect to the nominal diameter ratios. The breast phantom thickness difference between MPT-TA and micro-CT is about 10%. We demonstrate the single-shot PT-TA and ST-TA techniques feasibility for thickness recovery of millimeter-sized samples using polychromatic microfocus X-ray sources. The application of MPT-TA for thicker and multi-material samples is promising.

Investigating the impact of thymol/ɤ-cyclodextrin concentrations on the properties of electrospun PLA/PVP nanofibers for packaging applications

This study focuses on the modification of Polylactic acid (PLA)/polyvinylpyrrolidone (PVP) nanofibers using thymol-loaded cyclodextrin (TC) to optimize their suitability for applications in food science and packaging. The researchers conducted a comprehensive investigation into the impact of TC concentration on the nanofiber morphology, chemistry, and functionality. Scanning electron microscopy (SEM) analysis revealed that the modification with TC led to a reduction in fiber diameter and an increase in bead formation compared to the unmodified nanofibers. Fourier transform infrared spectroscopy (FTIR) analysis confirmed chemical alterations resulting from TC incorporation. The mechanical properties of the nanofibers were significantly enhanced with increasing TC content, as demonstrated by increased tensile strength and reduced elongation. This indicates improved mechanical strength and resilience of the nanofibers. Furthermore, the modified nanofibers exhibited notable improvements in antioxidant and antibacterial activities. They demonstrated remarkable antibacterial efficacy against both E. coli and S. aureus. This suggests that the incorporation of TC enhanced the antimicrobial properties of the nanofibers. Thymol release from the nanofibers reached its peak at a TC concentration of 10 %. This indicates that the release of thymol can be optimized by adjusting the TC content in the nanofibers. Overall, the results of this study demonstrated improved properties such as moisture management, mechanical properties, and antimicrobial activity in the modified nanofibers. These findings highlight the suitability of TC-modified nanofibers for various applications in the food industry, particularly in food science and packaging.

Extracting and characterizing novel cellulose fibers from Chamaerops humilis rachis for textiles' sustainable and cleaner production as reinforcement for potential applications

New cellulose (CL) fibers are derived from Chamaerops humilis (Ch) rachis. They play an essential role in various industries to produce environmentally friendly products as an alternative to enhancing and strengthening lightweight composites, such as dashboards automotive. Distinctive properties of Ch fibers (ChFs) were determined by extracting fibers from dwarf palm plant branches using anaerobic analysis. This search comprehensively studies morphological, physical, mechanical, and thermal characteristics and water absorption testing. The fiber diameter was 241.23 ± 34.77 μm, while the obtained linear density and density were 13.71 ± 0.57 Tex and 0.801 ± 0.05 g/cm3, respectively. The moisture content was 8.5 %, and the moisture regain was 9.29 %. Scanning electron microscopy images showed the fibers and smooth and rough surfaces. The thermogravimetric analysis demonstrated the maximum degradation of 352 °C, thermal stability of 243 °C, and the kinetic activation energy reached (79.78 kJ/mol). X-ray diffraction proves the availability of CL, with a crystallinity index = 68.38 % and crystal size = 2.92 nm. Fourier transform infrared succeeded in detecting functional groups and chemical compounds of fibers. The fibers exhibited a tensile stress of 110.85 ± 77.08 MPa, an elongation at a break rate of 2.29 ± 1.27 %, and Young's modulus of 6.05 ± 3.9 GPa. The maximum likelihood method (2P-Weibull distribution) was employed to examine the distribution of mechanical properties of fibers. According to the results above, new ChFs are an excellent reinforcement for elaborating fiber-reinforced biocomposites.

Design of inherently polarized nanofiber-based membranes for superior filtration performance

As airborne particulate matter (PM) such as pathogens and ultrafine dust threaten the human health, air quality control technologies are becoming increasingly important. Herein, poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) nanofibers with various fiber diameters and pore size distributions were prepared using various compositions of volatile (acetone) and less volatile N,N-dimethylformamide (DMF) solvent mixtures to design the optimum filtration media. Morphologies and molecular configurations were examined thoroughly with respect to the filtration performance. Among the various solvent compositions, the specimen prepared with the lowest DMF content (denoted as ePVdF-HFP55) showed the best filtration performance, with a filtration efficiency of 99.95% and a pressure drop of 29.0 mmH2O. The quality factor (QF) of ePVdF-HFP55 (0.0266 Pa−1) is superior to that achieved in electrospun nanofibrous media in previous works. In addition, the QF was further improved to 0.0276 Pa−1, with a remarkably reduced resistance of 14.45 mmH2O achieved by employing the layered nanofiber media with a PVdF-HFP top layer. Our work demonstrates that optimization of the inherently polarized nanofiber synthesis is a fruitful pathway to enhancing the filtration performance of air filter media.

Electrospinning of emulsions stabilized by octenylsuccinylated starch and pullulan

Emulsion electrospinning emerges as a promising technique for producing core-shell nanofibers used in delivering bioactive compounds. This work aims to investigate the feasibility of employing octenylsuccinylated (OS) starch-based emulsions in electrospinning for the fabrication of these nanofibers. The influence of sunflower seed oil concentration, ranging from 5% to 50%, on the emulsions was systematically examined. Increasing the oil concentration affects several key characteristics of the emulsions. These changes include a rise in apparent viscosity (from 0.78 to 7.72 Pa·s at 100 s−1) and average droplet size (from 1.21 to 1.79 μm), as well as a decrease in conductivity (from 727 to 193 μs/cm), leading to a larger average diameter of electrospun fibers, which increased from 294 to 533 nm. Confocal laser scanning microscopy and transmission electron microscopy confirmed the core–shell structure of the fibers. Furthermore, the correlation between fiber size and emulsion properties was discussed, and it was noted that the average fiber diameter, loading capacity, and encapsulation efficiency were significantly affected by emulsion composition and properties. These insights contribute to our understanding of the emulsion electrospinning process and offer a valuable guidance for the development of OS starch-based core–shell electrospun fibers.

Numerical investigation of various laser–waterjet coupling methods on spot power density distribution

This paper presents a numerical simulation study on the coupling of lasers and waterjets, focusing on the distribution of the spot power density. The analysis utilized a laser wavelength of 532 nm, chosen for its minimal energy attenuation in water. The key conditions for successful coupling were identified, including the necessity for the spot diameter of the laser beam to be smaller than the nozzle diameter of the waterjet fiber, the numerical aperture of the laser beam to be lower than that of the waterjet fiber, and the divergence angle of the laser to be smaller than the critical angle for total internal reflection. Using the ZEMAX simulation software, various coupling cases were explored, revealing that the radial displacement of the waterjet fiber relative to the laser axis has the most significant impact on the output power density, followed by angular deflection, whereas the axial displacement has the minimal effect. This study also investigates the combined effects of different influencing factors on the peak distribution of the output power density, uncovering distinct characteristics resulting from these deviations. Overall, the research findings provide theoretical insights for achieving effective coupling between fine waterjets and lasers as well as for the design of water-guided laser coupling devices.

Dietary guanidinoacetic acid as arginine spare molecule for beef cows at late gestation: Effects on cow’s performance and metabolism, and offspring growth and development

We aimed to assess whether guanidinoacetic acid (GAA) affects the performance, metabolism, and placental vascularization of pregnant beef cows during late gestation as well as its impact on the offspring’s performance. Twenty-eight pregnant Brahman cows, averaging 532±15.1 kg and carrying male (n=15) and female (n=13) fetuses, were used. The basal diet consisted of 688 g/kg corn silage, 147 g/kg sugarcane bagasse, 47.7 g/kg corn, 89.6 g/kg soybean meal, 6.86 g/kg urea, and 21.2 g/kg mineral mixture (DM basis). Cows were fed the experimental diets from 180 to 270 days of gestation. The following treatments were evaluated: control (no addition of GAA) or addition of 0.2 % GAA to the total diet (DM basis). There was no effect (P≥0.37) of GAA on voluntary intake. Similarly, GAA addition did not affect (P≥0.54) cows performance variables, except for ribeye area (REA), which had a lower (P<0.01) variation compared to the initial REA in cows fed dietary GAA compared to the control group. Dietary GAA increased (P≤0.02) both serum nitric oxide and placental vascularization compared to cows fed the control diet. There was no effect (P≥0.43) of GAA on urine and serum creatine concentrations. In contrast, dietary GAA increased (P≤0.03) plasma concentration of arginine, ornithine, citrulline, and tyrosine compared to the control. Conversely, dietary GAA decreased (P<0.02) plasma methionine concentration. Dietary GAA increased AGAT activity (P<0.03) in the liver, with no differences observed (P>0.68) on GAMT activity. There was no effect (P≥0.15) of GAA on performance of the offspring. Addition of GAA in maternal diet did not affect skeletal muscle fiber number (P>0.09) and diameter (P>0.23) of the offspring. Guanidinoacetic acid decreases skeletal muscle mobilization and enhances placental vascularization of beef cows during late gestation. However, providing GAA seems to not affect the performance of the offspring.