Smooth Surface Research Articles

Effect of osteon-like concentric microgroove structures of different sizes on the osteoclastic differentiation of macrophages

Objective: To investigate the effect of the sizes of osteon-like concentric microgroove structures on the osteoclastic differentiation of macrophages on titanium surfaces, and to provide reference for the surface modification of implants. Methods: The silicon wafers sputtered with titanium were selected as the control group (smooth surface specimens) and four concentric groups (concentric circles with the maximum diameter of 200 μ m, the minimum diameter of 20 μ m, the spacing of concentric circles of 10 or 30 μm, the width of microgrooves of 10 or 30 μm, and the depth of microgrooves of 5 or 10 μm) specimens (the total sample size in each group was 27). The width of microgrooves of C10-5 and C10-10 groups was 10 μm, the depth was 5 and 10 μm, and the width of microgrooves of C30-5 and C30-10 groups was 30 μ m, the depth was 5 and 10 μ m, respectively. The physicochemical properties of the material surfaces were characterized using scanning electron microscopy and contact-angle measurement. The proliferation, adhesion of macrophage-like cell line RAW264.7 and the formation of osteoclast actin-rings on the specimen surfaces were observed by cell counting kit-8 (CCK-8), immunofluorescence staining and laser confocal microscopy. Tartrate resistant acid phosphatase (TRAP) quantitative detection, real-time fluorescence quantitative PCR (RT-qPCR) and Western blotting were used to investigate the regulation of osteon-like concentric microgroove structures on the specimen surfaces on the osteoclastic differentiation of macrophages. Results: Macrophages aggregated and grew disorderly on the surface of the smooth group, and arranged in concentric circles along the microgroove structures on the surfaces of the concentric groups. After 5 days of culture, the cell proliferation of C30 groups (the A values of C30-5 group and C30-10 group were 1.335±0.018 and 1.340±0.033, respectively) was significantly higher than that of C10 groups (the A values of C10-5 group and C10-10 group were 0.967±0.015 and 1.182±0.020, respectively). The cell proliferation of the four concentric groups was significantly higher than that of the control group (the A value was 0.796±0.012), with statistical significance (P<0.05). The osteoclasts induced in the C10-5 and C10-10 groups exhibited smaller actin rings and fewer numbers. The TRAP activity in each concentric group was significantly lower than that in the control group (P<0.05). The expression levels of osteoclast differentiation-related genes TRAP (0.610±0.022) and CtsK (0.445±0.037) in the C10-10 group were lower compared to the smooth group and other concentric groups, with statistical significance (P<0.05), the expression levels of osteoclast differentiation-related proteins TRAP (0.648±0.041), matrix metalloproteinase 9 (MMP-9) (0.688±0.026), and CtsK (0.491±0.016) in the C10-10 group were also lower compared to the smooth group and other concentric groups, with statistical significance (P<0.05). Conclusions: The osteon-like concentric microgroove structures inhibit the osteoclastic differentiation of macrophage-like cell line RAW264.7, with the microgrooves 10 μm wide and 10 μm deep showing the most significant inhibitory effect on the osteoclastic differentiation.

Wheat straw-based carboxymethyl cellulose and glycerol films enriched with polymalate: Characterization and application in grape preservation.

The shelf-life of grapes is reduced due to infection by various pathogens and mechanical damage, which consequently limits their availability on the market and results huge economic losses. Active packaging films are expected to overcome this problem. In this study, packaging films (CMC-Gly-PMA) were developed using wheat straw-based carboxymethyl cellulose (2%), glycerol (30% w/w of CMC) and polymalate (0.9%) to prolong the grape shelf-life. With regard to physical properties of films, TS, EB, OP and WVP were 28.4MPa, 142.1%, 8.52mmol/kg and 0.55×10-12g·m/m2·s·Pa, respectively. The FTIR spectra indicated that the interactions between CMC, glycerol and polymalate within the matrix were primarily physical in film formation process. In addition, the film cross-section showed a compact yet smooth surface. Films had UV barrier performance and positive antibacterial effects on E. coli and S. aureus. From the composting experiment, films decomposed almost entirely on day 21. Besides, during the storage period, the coated grape exhibited a lower decay index, weight loss and respiration rate than the control group, and the coated grape exhibited greater hardness than the control group. It can therefore be concluded that the coating treatment preserved grape quality and extended their shelf-life. The findings suggest that the active film has the potential to serve as an edible and biodegradable material for food packaging, which represents a promising avenue for further research in this field and supports the transition towards a circular economy in the packaging industry.

Ultrasmooth Micromilling of Stainless Steel by Ultrashort Pulsed Laser Ablation Using MHz Bursts.

Ultrashort pulsed (USP) laser burst ablation has attracted numerous interests for its great potential in enhancing ablation efficiency and reducing the heat-affected zone. However, little attention has been paid to the influence of burst ablation on the processed surface quality. To fill this research gap, the present study conducts a comprehensive investigation on the surface processing of stainless steel using ultrashort pulsed laser burst ablation. Systematic experiments have been carried out to investigate influences of pulse number per burst (PpB), pulse fluence, and burst overlap ratio on surface quality and ablation efficiency. A two-dimensional model has been developed to unveil the fundamental thermodynamic process and evolution of ablation and melting in material during USP laser burst ablation. Compared to single-pulse ablation, the optimum ablation efficiency decreases with increasing PpB by less than 30% in burst ablation. Despite reduced ablation efficiency, burst-mode ablation can generate much better surface quality, achieving an ultrasmooth surface with an Sa roughness as low as 0.13 μm. Burst ablation generates distinctive surface structures compared to single-pulse ablation, and their formation mechanisms are scrutinized. The thickness of the surface melting layer is unveiled to determine surface morphology. Based on transmission electron microscopy (TEM) analysis and numerical simulation, a melting layer thickness between 100 and 320 nm is found to result in smooth surfaces. This work highlights the advantage of burst-mode ablation in achieving ultrasmooth surfaces on stainless steel and unveils the fundamental mechanisms of surface structures formation in USP laser burst ablation.

Formulation, development and in vivo characterization of selegiline hydrochloride nanostructured lipid nanocarrier loaded microneedle array patch for depression.

Depression is a common mental condition causing depressed mood and loss of pleasure. The primary treatment approach for the management of depression consists of the use of selegiline (MAO-B) inhibitor compound. The present work aimed to develop and optimize selegiline-loaded nanostructured lipid carriers for transdermal application, utilizing a 23 full factorial design approach. The optimized nanostructured lipid carriers formulation (Batch B7) demonstrated a particle size of 158.71±0.56nm, a narrow size distribution (0.266±0.006), high entrapment efficiency (59.60±0.34%), and a zeta potential of -23.2±2.21mV. Furthermore, x-ray diffraction and differential scanning calorimetry studies revealed the amorphous transformation of selegiline within the nanostructured lipid carrier. Transmission Electron Microscopy study has shown that nanostructured lipid carrier particles had a spherical shape with a smooth surface. These optimized nanostructured lipid carriers were then incorporated into a microneedle array patch for transdermal delivery. The selegiline-loaded nanostructured lipid carrier microneedle array patch exhibited no skin irritation in a rabbit model. It enhanced drug diffusion ex vivo (1.13-fold compared to pure selegiline-loaded microneedle array patch) with 90% drug release in 12h. The pharmacokinetic study demonstrated a steady and controlled release profile with a half-life of 29.9±0.14h and AUC0-t (26.57±0.51 μg/ml*h) of selegiline loaded nanostructured lipid carrier microneedle array patch. On the contrary, a pure selegiline-loaded microneedle array patch showed a short half-life of 6.5±0.26h and AUC0-t (20.90±0.31μg/ml*h). The sustained release profile and prolonged half-life in plasma and the brain suggest improved therapeutic efficacy. Histopathology analysis revealed no significant toxicity to vital organs. Thus, a selegiline nanostructured lipid carrier-loaded microneedle array patch can increase brain bioavailability compared to a pure selegiline-loaded microneedle array patch for managing depression.

Novel metal-organic framework coated with chitosan-κ-carrageenan as a platform for curcumin delivery to cancer cells.

Metal-organic frameworks (MOFs) have shown great promise as pH-responsive drug delivery systems, with considerable potential for targeted cancer therapy. In this study, we synthesized a novel curcumin-loaded MOF, named UWO-2 (CUR@UWO-2), and developed its biocomposite form, CS-κ-Cr/CUR@UWO-2, by coating it with chitosan (CS) and κ-carrageenan (κ-Cr). Structural analysis through powder X-ray diffraction (PXRD) confirmed the successful synthesis of UWO-2 and the incorporation of CUR within the MOF structure. X-ray photoelectron spectroscopy (XPS) analysis revealed two distinct peaks at approximately 1021.15 eV and 1044.23 eV, corresponding to the Zn 2p₃/₂ and Zn 2p₁/₂ states, respectively. These peaks confirm the presence of the expected Zn2+ oxidation state in UWO-2, further validating its successful synthesis. Brunauer-Emmett-Teller (BET) analysis demonstrated a significant decrease in surface area (367.4 m2/g) and pore volume (0.296 cm3/g), validating the entrapment of CUR within the UWO-2 MOF structure. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images revealed that UWO-2 particles are spherical with a smooth surface, while CUR@UWO-2 exhibited a larger particle size, indicating successful curcumin loading. Thermogravimetric analysis (TGA) indicated enhanced thermal stability due to CUR loading, while swelling experiments revealed increased water absorption at neutral pH, supporting effective drug release under physiological conditions. Biodegradation studies showed sustained degradation of CUR@UWO-2 in the presence of lysozyme, confirming its suitability for in vivo applications. The drug delivery system achieved 21.9 % drug loading and 75.1 % encapsulation efficiency. Drug release experiments indicated accelerated release under acidic conditions, with the Korsmeyer-Peppas model identifying Fickian diffusion as the primary release mechanism. Cytotoxicity assessments showed increased cell death with CUR@UWO-2, enhanced by the synergistic effect of UWO-2, while the CS-κ-Cr coating enabled controlled, prolonged curcumin release. Confocal microscopy confirmed cellular uptake of CUR, underscoring the potential of the biocomposite for tumor-targeted chemotherapy applications in cancer treatment. This study highlights the potential of CUR@UWO-2, especially in its biocomposite form, for tumor-targeted drug delivery applications.

Effect of surface roughness on the efficacy of Plasma Activated Mist (PAM) for inactivation of Listeria innocua and Klebsiella michiganensis.

Cold plasma generated by dielectric barrier discharge (DBD) and DBD combined with nebulized liquid microdroplets to generate plasma-activated mist (PAM) have shown the potential as a surface decontamination method for the food industry. The objective of this research was to measure the microbial inactivation caused by DBD and by PAM on tryptic soy agar (TSA) and on glass slides and to determine the efficacy of PAM on selected surfaces having different surface topographies. Tryptic soy agar in Petri dishes and on glass slides (surface roughness Pq=0.28±0.02μm) was inoculated with either 0.1mL of inoculum containing Listeria innocua (8.4±0.1 log CFU/mL) or Klebsiella michiganensis (8.8±0.2 log CFU/mL) and exposed to either DBD or PAM for 5 to 20min. Glass slides, grape tomatoes (Pq=5.17μm±0.53μm), limes (Pq=18.76μm±3.00μm), and spiny gourds (Pq=101.50μm±10.95μm) were also surface-inoculated with L. innocua or K. michiganensis and exposed to PAM for 5 to 20min. No significant difference in microbial inactivation was observed between DBD plasma and PAM for all treatment times. The smoothest surface (glass) showed the highest reduction in L. innocua (3.4±0.2 log CFU/item) and K. michiganensis (5.7±0.0 log CFU/item) after PAM treatment. The roughest surface (spiny gourd) yielded a significantly lower reduction for L. innocua (1.0±0.2 log CFU/item) and K. michiganensis (1.8±0.1 log CFU/item). L. innocua was less susceptible to inactivation by PAM compared K. michiganensis. This study highlighted the importance of surface roughness on microbial inactivation of L. innocua and K. michiganensis by DBD and PAM on produce surfaces.

Study of the influence of ultra-high molecular weight polyethylene and high-density polyethylene on the properties and structure of ethylene propylene diene monomer rubber

Objectives. The study set out to examine the impact of pre-mixed ultra-high molecular weight polyethylene (UHMWPE) and high-density polyethylene (HDPE) on a range of properties and structural characteristics of SKEPT-50 ethylene propylene diene monomer (EPDM) rubber.Methods. The production of rubber mixtures involved the pre-mixing of rubber with UHMWPE and HDPE in a Brabender PL 2200-3 plasti-corder chamber (Germany) at a temperature of 160°C, for a period of 6 min, and with a rotor speed of 60 rpm. The polyethylene constituents were incorporated into the rubber compound at concentrations of 5, 10, and 15 pts. wt. The subsequent introduction of the principal constituents of the rubber mixture was conducted in an SYM laboratory mill (China) for a period of 30 min at a temperature of no more than 100°C. The vulcanization of the samples was conducted in an Y1000D vacuum hydraulic press (China) at a temperature of 185°C for a period of 35 min. The investigation of vulcanization and physical and mechanical properties was conducted in accordance with the established protocols. The analysis of the rubber supramolecular structure was conducted using a JEOL JSM-6840 LV scanning electron microscope (Japan).Results. The results demonstrate that an increase in the proportion of HDPE and UHMWPE to 15 pts. wt leads to a notable enhancement in the hardness of the rubbers by 10 and 5 Shore A units, respectively. The frost resistance coefficient at −45°C demonstrates an increase with the incorporation of 10 pts. wt of HDPE to reach a value of 0.229, and a further increase with the incorporation of 15 pts. wt of UHMWPE to reach a value of 0.260. The degree of swelling of rubbers in a DOT-4 brake fluid environment is observed to decrease to 13% for rubbers with HDPE and 19% with UHMWPE. The degree of swelling of rubbers in the DOT-4 brake fluid environment is observed to decrease to 13% for rubbers with HDPE and 19% with UHMWPE. While an increase in the HDPE content results in a 5% increase in volumetric wear, an increase in the UHMWPE content is associated with a 45% decrease in volumetric wear. The introduction of UHMWPE was observed to result in the formation of inclusions of varying shapes and sizes within a range of 50–100 µm. The transition zone between UHMWPE and rubber is characterized by a smooth surface. No evidence of cracks or micro-tears between the polymer phases, which could potentially form during low-temperature splitting, was observed. This finding indicates the presence of favorable interfacial interactions, which can be linked to the observed enhancements in resistance to aggressive liquids and abrasion, as well as the improved tensile frost resistance coefficient. The supramolecular structure of rubber samples combined with HDPE is more pronounced and exhibits greater relief than that of the original rubber. This is indicative of a more uniform distribution within the matrix volume, which can be attributed to the high fluidity of the HDPE melt.Conclusions. Rubbers modified with UHMWPE, in comparison with HDPE, exhibit enhanced resistance to wear, oil, and frost, while maintaining their elastic and strength properties. It was established that rubber containing 15 pts. wt of UHMWPE exhibits optimal properties and can thus be recommended for use in sealing rubber products.

Bone Marrow Stromal Cells Generate a Pro-Healing Inflammasome When Cultured on Titanium-Aluminum-Vanadium Surfaces with Microscale/Nanoscale Structural Features.

The surface topography and chemistry of titanium-aluminum-vanadium (Ti6Al4V) implants play critical roles in the osteoblast differentiation of human bone marrow stromal cells (MSCs) and the creation of an osteogenic microenvironment. To assess the effects of a microscale/nanoscale (MN) topography, this study compared the effects of MN-modified, anodized, and smooth Ti6Al4V surfaces on MSC response, and for the first time, directly contrasted MN-induced osteoblast differentiation with culture on tissue culture polystyrene (TCPS) in osteogenic medium (OM). Surface characterization revealed distinct differences in microroughness, composition, and topography among the Ti6Al4V substrates. MSCs on MN surfaces exhibited enhanced osteoblastic differentiation, evidenced by increased expression of RUNX2, SP7, BGLAP, BMP2, and BMPR1A (fold increases: 3.2, 1.8, 1.4, 1.3, and 1.2). The MN surface also induced a pro-healing inflammasome with upregulation of anti-inflammatory mediators (170-200% increase) and downregulation of pro-inflammatory factors (40-82% reduction). Integrin expression shifted towards osteoblast-associated integrins on MN surfaces. RNA-seq analysis revealed distinct gene expression profiles between MSCs on MN surfaces and those in OM, with only 199 shared genes out of over 1000 differentially expressed genes. Pathway analysis showed that MN surfaces promoted bone formation, maturation, and remodeling through non-canonical Wnt signaling, while OM stimulated endochondral bone development and mineralization via canonical Wnt3a signaling. These findings highlight the importance of Ti6Al4V surface properties in directing MSC differentiation and indicate that MN-modified surfaces act via signaling pathways that differ from OM culture methods, more accurately mimicking peri-implant osteogenesis in vivo.

Mid-Infrared High-Power InGaAsSb/AlGaInAsSb Multiple-Quantum-Well Laser Diodes Around 2.9 μm.

Antimonide laser diodes, with their high performance above room temperature, exhibit significant potential for widespread applications in the mid-infrared spectral region. However, the laser's performance significantly degrades as the emission wavelength increases, primarily due to severe quantum-well hole leakage and significant non-radiative recombination. In this paper, we put up an active region with a high valence band offset and excellent crystalline quality with high luminescence to improve the laser's performance. The miscibility gap of the InGaAsSb alloy was systematically investigated by calculating the critical temperatures based on the delta lattice parameter model. As the calculation results show, In0.54Ga0.46As0.23Sb0.77, with a compressive strain of 1.74%, used as the quantum well, is out of the miscibility gap with no spinodal decomposition. The quantum wells exhibit high crystalline quality, as evidenced by distinct satellite peaks in XRD curves with a full width at half maximum (FWHM) of 56 arcseconds for the zeroth-order peak, a smooth surface with a root mean square (RMS) roughness of 0.19 nm, room-temperature photoluminescence with high luminous efficiency and narrow FHWM of 35 meV, and well-defined interfaces. These attributes effectively suppress non-radiative recombination, thereby enhancing internal quantum efficiency in the antimonide laser. Furthermore, a novel epitaxial laser structure was designed to acquire low optical absorption loss by decreasing the optical confinement factor in the cladding layer and implementing gradient doping in the p-type cladding layer. The continuous-wave output power of 310 mW was obtained at an injection current of 4.6 A and a heatsink temperature of 15 °C from a 1500 × 100 μm2 single emitter. The external quantum efficiency of 53% was calculated with a slope efficiency of 0.226 W/A considering both of the uncoated facets. More importantly, the lasing wavelength of our laser exhibited a significant blue shift from 3.4 μm to 2.9 μm, which agrees with our calculated results when modeling the interdiffusion process in a quantum well. Therefore, the interdiffusion process must be considered for proper design and epitaxy to achieve mid-infrared high-power and high-efficiency antimonide laser diodes.

A double-layered CRCP: experiences on the E34 near Antwerp (Belgium)

The technique of double-layered concrete or two-lift paving is applied either to obtain a high-quality top layer, to use lower quality materials in the lower lift, or for both reasons at the same time. In Europe this technique is commonly applied in Austria where a typical motorway is built with a 25 cm-thick jointed plain concrete pavement consisting of a 20 cm lower layer and a 5 cm upper layer. For the coarse aggregates of the first layer, recycled crushed concrete from former pavements replace the natural stones while the top layer is made of small, polishing-resistant stones with a maximum aggregate size of 8 mm. Driven by growing environmental awareness and a desire for innovation, the Flemish Road Authorities followed the Austrian example and planned a trial worksite on a 3 km section of the E34 motorway in Zwijndrecht near Antwerp. Following Belgian tradition, the existing JPCP was replaced with a CRCP. The paper will describe the pavement design and construction details, the concrete mix design and the evaluation of the road surface characteristics of the finished road. By adopting the CRCP long-life pavement concept, the use of reclaimed aggregates and the result of a quieter and smoother surface, different aspects of sustainable construction are combined, to good effect, in this technique.

Hydrolethalus Syndrome: A Case of a Rare Congenital Disorder.

This is a fatal case of multiple complicated congenital anomalies displaying several symptoms consistent with hydrolethalus syndrome. The newborn's phenotype is characterized by a combination of serious anatomical abnormalities such as open-book cerebral hemispheres, defective lobulation of the lungs (one lobe on the left, two on the right), a smaller right kidney, a smooth cerebral surface, and a specific keyhole-shaped defect in the skull base, primarily associated with hydrocephalus.

Enhanced targeted treatment of cervical cancer using nanoparticle-based doxycycline delivery system

This study investigates a nanoparticle-based doxycycline (DOX) delivery system targeting cervical cancer cells via the CD44 receptor. Molecular docking revealed a strong binding affinity between hyaluronic acid (HA) and CD44 (binding energy: -7.2 kJ/mol). Characterization of the HA-Chitosan nanoparticles showed a particle size of 284.6 nm, a zeta potential of 16.9 mV, and a polydispersity index of 0.314, with SEM confirming smooth surface morphology. The encapsulation efficiency of DOX-loaded nanoparticles was 89.32%, exhibiting a sustained release profile, with 67.45% released over 72 h in acidic conditions (pH 5.5). Cytotoxicity assays demonstrated a significant reduction in HeLa cell viability to 22% at 72 h, compared to 67% in normal HEK cells. Stability tests confirmed the maintenance of nanoparticle integrity and a consistent drug release profile over three months. Cell migration was reduced by 45%, and RT-PCR analysis revealed a 53% downregulation of TNF-α expression, suggesting effective targeting of inflammatory pathways. These results underscore the potential of HA-Chitosan-based DOX nanoparticles in improving cervical cancer treatment through enhanced targeted delivery and inhibition of tumor-promoting mechanisms.

Research on the Aging Characteristics of Simulated Asphalt Within Pavement Structures in Natural Environments.

The global asphalt production growth rate exceeded 10% in the past decade, and over 90% of the world's road surfaces are generated from asphalt materials. Therefore, the issue of asphalt aging has been widely researched. In this study, the aging of asphalt thin films under various natural conditions was studied to prevent the distortion of indoor simulated aging and to prevent the extraction of asphalt samples from road surfaces from impacting the aged asphalt. The aging of styrene-butadiene-styrene (SBS)-modified asphalt was simulated at four different locations on an asphalt road surface. The aging characteristics of asphalt binders across various structural layers were revealed using Fourier transform infrared spectroscopy (FTIR), atomic force microscopy (AFM), and linear amplitude scanning (LAS). The results indicate that the aging behavior of the asphalt functional group on the road surface differs from other conditions; the asphalt fatigue life of 4 months equates to the 16-month aging life of asphalt within the dense-graded asphalt road surface. After 8 months of aging, the surface smoothness of the asphalt was significantly compromised. Inside of the porous pavement, the asphalt functional group is more likely to interact with water molecules than inside the dense pavement with cracks, and the variations in roughness and the reduction in fatigue life are also more significant.

Influence of Initial Gap, Voltage, and Additives on Zinc Microcolumn Morphology by Local Electrochemical Deposition.

Local electrochemical deposition (LECD) is an innovative additive manufacturing technology capable of achieving precise deposition of metallic microstructures. This study delves into the ramifications of pivotal operational parameters-namely, the initial electrode gap, deposition voltage, and additive concentration-on the morphology of zinc microcolumns fabricated through LECD. A holistic approach integrating experimental methodologies with finite element simulations was adopted to scrutinize the influence of these variables on the microcolumns' dimensions, surface morphology, and structural integrity. The findings reveal that augmenting the initial electrode gap results in microcolumns with larger diameters. Conversely, the deposition voltage primarily modulates the formation rate without exerting a notable impact on the columns' dimensional attributes. The incorporation of additives enhances surface smoothness and diminishes column diameters; however, an overabundance of additives adversely affects the overall microstructure. Optimal parameters for the production of high-quality zinc microcolumns were determined to be a deposition voltage of 3.4 V and an electrode gap of 10 μm. These discoveries contribute pivotal insights for the refinement of LECD processes, with particular relevance to biomedical applications, such as the development of zinc-based bioabsorbable materials for orthopedic implants and cardiovascular devices.

Impact of Retention Agents on Functional Properties of Recycled Paper in Sustainable Manufacturing

The proper dosing and optimization of retention additives are necessary to ensure the desired benefits without compromising other aspects of the paper manufacturing process. In this study, the effects of a cationic polyelectrolyte based on acrylamide and a cationic derivative of acrylic acid on the different properties of paper containing recycled fibers were investigated. The structural and tensile properties were examined through various analyses to determine the optimal dosage of the retention additive. The results obtained indicate that while the retention agent can enhance papermaking efficiency by improving retention, drainage, and sheet formation, it also negatively impacts the tensile strength and surface smoothness of the recycled paper. This complexity highlights the importance of a balanced approach in optimizing retention aid dosages. Determining the optimum dosage of such an agent requires multiple trials and analyses with varying dosages. This review aims to offer a background for engineers seeking to enhance the competitiveness and reduce production costs of their paper products, as well as for researchers striving to surpass the existing standards and achieve innovative outcomes.

Downscaling of Non-Van der Waals Semimetallic W5N6 with Resistivity Preservation.

The bulk phase of transition metal nitrides (TMNs) has long been a subject of extensive investigation due to their utility as coating materials, electrocatalysts, and diffusion barriers, attributed to their high conductivity and refractory properties. Downscaling TMNs into two-dimensional (2D) forms would provide valuable members to the existing 2D materials repertoire, with potential enhancements across various applications. Moreover, calculations have anticipated the emergence of uncommon physical phenomena in TMNs at the 2D limit. In this study, we use the atomic substitution approach to synthesize 2D W5N6 with tunable thicknesses from tens of nanometers down to 2.9 nm. The obtained flakes exhibit high crystallinity and smooth surfaces. Electrical measurements on 15 samples show an average electrical conductivity of 161.1 S/cm, which persists while thickness decreases from 45.6 to 2.9 nm. The observed weak gate-tuning effect suggests the semimetallic nature of the synthesized 2D W5N6. Further investigation of the conversion mechanism elucidates the crucial role of chalcogen vacancies in the precursor for initiating the reaction and strain in propagating the conversion. Our work introduces a desired semimetallic crystal to the 2D material library with mechanistic insights for future design of the synthesis.

Selenium-Modified Biochar Synergistically Achieves the Safe Use of Selenium and the Inhibition of Heavy Metal Cadmium.

To address cadmium pollution in China's cultivated land, chitosan, inorganic and organic selenium were used to modify rice husk charcoal for cadmium inhibition. Basic physicochemical properties of rice husk carbons were characterized (BET, FTIR, XRD, Zeta potential). Kinetic and isothermal adsorption experiments studied the adsorption of Cd2+ by modified biochar under different pH and dosages. A350 and C350 had pore changes, and B350 had a smoother surface. The polarity and Zeta potential of A350, B350, and C350 differed. B350 and C350's kinetic adsorption fit the pseudo second order model, A350's fit both the pseudo first and second order. Their isothermal adsorption fit Langmuir (B350, C350) and Freundlich (A350). Intraparticle diffusion was three-stage with single-layer chemical adsorption. The pH increase raised removal and adsorption of CK350, A350, B350, and C350. The dosage increase hiked removal but cut unit adsorption. A350 had the highest max adsorption (57.845 mg/g). All modifications enhanced Cd2+ adsorption, and the effect could be altered by adjusting pH and dosage.

Nanoparticles for Biomedical Use Derived from Natural Biomolecules: Tannic Acid and Arginine.

Background/Objectives: Tannic acid (TA) is a well-known natural phenolic acid composed of ten gallic acids linked to each other with ester bonding possessing excellent antioxidant properties in addition to antimicrobial and anticancer characteristics. Arginine (ARG) is a positively charged amino acid at physiological pH because of nitrogen-rich side chain. Method: Here, poly(tannic acid-co-arginine) (p(TA-co-ARG)) particles at three mole ratios, TA:ARG = 1:1, 1:2, and 1:3, were prepared via a Mannich condensation reaction between TA and ARG by utilizing formaldehyde as a linking agent. Results: The p(TA-co-ARG) particles in 300-1000 nm size range with smooth surfaces visualized via SEM analysis were attained. Abundant numbers of functional groups, -OH, -NH2, and -COOH stemming from TA and ARG constituent confirmed by FT-IR analysis. The isoelectric point (IEP) of the particles increased from pH 4.98 to pH 7.30 by increasing the ARG ratios in p(TA-co-ARG) particles. The antioxidant capacity of p(TA-co-ARG) particles via gallic acid (GA) and rosmarinic acid (RA) equivalents tests revealed that particles possess concentration-dependent antioxidant potency and increased by TA content. The α-glucosidase inhibition of p(TA-co-ARG) particles (2 mg/mL) 1:1 and 1:2 mole ratios revealed significant enzyme inhibition ability, e.g., 91.3 ± 3.1% and 77.6 ± 12.0%. Interestingly, p(TA-co-ARG) (1:3 ratio) possessed significant antibacterial effectiveness against Escherichia coli (ATCC 8739) and Staphylococcus aureus (ATCC 6538) bacteria. Furthermore, all p(TA-co-ARG) particles at 1000 mg/mL concentration showed >80% toxicity on L929 fibroblast cells and increased as ARG content of p(TA-co-ARG) particles is increased. Conclusions: p(TA-co-ARG) showed significant potential as natural biomaterials for biomedical use.

Chitosan/Polyvinyl Alcohol/g-C3N4 Nanocomposite Film: An Efficient Visible Light-Responsive Photocatalyst and Antimicrobial Agent

Biopolymer-based nanocomposite film is an efficient material for addressing the increasing levels of pollutants in the environment and also for the production of antimicrobial packing material due to its good film-forming properties, biodegradability, and minimal environmental impact. In particular, chitosan/polyvinyl alcohol/g-C3N4 (CS/PVA/g-C3N4) nanocomposite films with different weight percentages of PVA were prepared using simple methodologies and characterized using XRD, TGA, FT-IR, DSC, FE-SEM, EDX, and elemental mapping analysis. The XRD and FT-IR results validated the nanocomposite film formation. The FE-SEM images showed the smooth surface of the composite films without any wrinkles; the smoothness of the film increased with increases in the PVA loading, and the surface morphologies of the films were largely unchanged. The EDX and elemental mapping analysis validated the presence and uniform dispersion of g-C3N4 within the nanocomposite film. The photocatalytic activity of the CS/PVA/g-C3N4 composite films was assessed by the degradation of rhodamine B dye (RhB) and acetophenone under direct sunlight irradiation. The CS/PVA/g-C3N4 nanocomposite films exhibited superior degradation efficiency toward the RhB dye and acetophenone compared to the bare polymeric film and the g-C3N4 material. The order of degradation for the RhB dye and acetophenone was CS/PVA (1.0) g-C3N4 (95.34%, 33.33%) &gt; CS/PVA (1.5) g-C3N4 (93.18%, 31.31%) &gt; CS/PVA (0.5) g-C3N4 (93.02%, 29.29%) &gt; CS/PVA (90.69%, 26.26%) &gt; g-C3N4 (87.56%, 24%), respectively. Furthermore, the antimicrobial activity of the nanocomposite films was tested against E. coli, Pseudomonas sps., Klesiella sps., and Enterococcus sps., and the CS/PVA (1.5)/g-C3N4 nanocomposite film offered better antimicrobial properties than the other composite films and bare materials. In conclusion, these biopolymer-based nanocomposites are highly efficient and provide a promising path for the development of various biodegradable polymeric nanocomposites for environmental remediation and antibacterial packing applications.

The Influence of Two Spinning Processes of T800 Grade Carbon Fibers on the Mechanical Properties of Thermoplastic Composite Material

Two types of T800 grade carbon fibers, produced using distinct spinning processes, were utilized to fabricate thermoplastic prepregs via the hot melt method. These prepregs were subsequently employed to produce thermoplastic composites. A universal testing machine was used to assess the tensile, bending, and interlaminar shear properties of the composites, evaluating the impact of the two different spinning processes on their mechanical characteristics. The experimental results indicate that the dry spray wet spinning carbon fiber (T800-DJWS) exhibits a smoother surface, more regular cross-section, and more uniform distribution compared to the wet spinning carbon fiber (T800-WS), enhancing the prepreg preparation via the hot melt method. The T800-DJWS/PAEK composite demonstrates a tensile strength that is 706 MPa higher than the T800-WS/PAEK composite, while the latter exhibits a bending modulus 31 GPa higher than the former.