Near-spherical Shape Research Articles

Determination of the shape and dimensions of the polymer molecules in solutions using diffusional NMR relaxation

A new method of determining the dimensions and shapes of polymer molecules in solutions is proposed and verified in experiments. The method is based on the measurements of the relaxation of the transverse magnetization intensity of nuclei. It is established that the decaying signal of the spin echo from elongated molecules contains two terms exponentially decaying with time, which correspond to two diffusion coefficients differing by a factor of about two. The signal from molecules with a near-spherical shape contain only one exponent.

Preparation of cellulose-based nanoparticles via electrostatic self-assembly for the pH-responsive delivery of astaxanthin

Oral administration of astaxanthin (AST), a potent antioxidant, is limited owing to its low solubility, physicochemical stability, and bioavailability. This study developed pH-responsive nanocarriers by the electrostatic self-assembly of 2,2,6,6-tetramethylpiperidine-1-oxyradical (TEMPO)-oxidized cellulose nanofibers (TCNFs) and chitosan (CS) to enhance the intestinal delivery of AST. The TCNF/CS@AST nanoparticles were optimized through single-factor experiments and Box–Behnken design, subsequently overcoming the hydrophobicity of AST and demonstrating improved stability against environmental stressors and controlled release in the intestinal environment. Transmission electron microscopy confirmed the near-spherical shape of these nanoparticles, with an average hydrodynamic diameter of 64 nm. TCNF/CS@AST enhanced the antioxidant effectiveness of AST after digestion and in lipopolysaccharide-stimulated RAW 264.7 cells while demonstrating good cellular compatibility. These nanoparticles present a promising strategy for the oral delivery of hydrophobic bioactive compounds orally, with potential applications in precision nutrition.

Luminous blue carbon quantum dots employing Anisomeles indica (catmint) induce apoptotic signaling pathway in triple negative breast cancer (TNBC) cells.

Herein, luminous blue carbon quantum dots (CDs) employing Anisomeles indica (Catmint) were reported with imaging, self-targeting, and therapeutic effects on triple-negative breast cancer (TNBC, MDA-MB-231) cells. The salient features of CDs generated from catmint are as follows: i) optical studies confirm CDs with excitation-dependent emission; ii) high-throughput characterization authenticates the formation of CDs with near-spherical shape with diameter ranging between 5 and 15 nm; iii) CDs induce cytotoxicity (3.22 ± 0.64 μg/ml) in triple-negative breast cancer (TNBC, MDA-MB-231) cells; iv) fluorescence microscopy demonstrates that CDs promote apoptosis by increasing reactive oxygen species (ROS) and decreasing mitochondrial membrane potential; v) CDs significantly up-regulate pro-apoptotic gene expression levels such as caspases-8/9/3. Finally, our work demonstrates that catmint-derived CDs are prospective nanotheranostics that augment cancer targeting and imaging.

Sono-synthesis and characterization of next-generation antimicrobial ZnO/TiO2 and Fe3O4/TiO2 bi-nanocomposites, for antibacterial and antifungal applications

Ultrasonic-assisted synthesis of ZnO/TiO₂ and Fe₃O₄/TiO₂ bi-oxide nanocomposites at low frequencies (60 kHz) with their characterizations and antibacterial/antifungal applications are investigated in this study. Using nanotechnology as the next-generation solution, this research explored the potential of metal oxide nanoparticles as effective antibacterial agents. Nanomaterials were synthesized via a novel and facile method (sono-synthesis) and characterized using various techniques (XRD, SEM, FTIR, zeta potential analysis, Raman spectroscopy, and XPS), revealing nanoscale sizes of 25 nm for ZnO/TiO₂ and 31 nm for Fe₃O₄/TiO₂. Structural analysis demonstrated the distinct crystalline phases of the synthesized nanomaterials: TiO₂ with anatase structure (25 %), hexagonal wurtzite structure for ZnO, and Fe₃O₄ with inverse spinel structure, formed in nano-dimensions (19–31 nm) with a near-spherical shape. Antibacterial and antifungal assays highlighted the efficacy of both bi-nanocomposites against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria, along with their potent activity against Candida albicans and non-albicans Candida. Moreover, principal component analysis (PCA) was used to identify potential relationships between the physicochemical properties (zeta potential, size, conductivity, and concentration) of all nanomaterials tested and their zone of inhibition (ZOI) against all bacterial species tested. Overall, this study emphasizes the novelty of employing a simple and efficient sono-synthetic route to synthesize ZnO/TiO₂ and Fe₃O₄/TiO₂ bi-nanocomposites and investigate their significant antibacterial and antifungal activities. Additionally, it identifies the potential relationships between the physicochemical properties of the nanomaterials tested and their antimicrobial activity. This approach provides a robust framework for future applications of bi-nanocomposites in combating microbial infections.

Effect of gastrointestinal resistant encapsulate matrix on spray dried microencapsulated Lacticaseibacillus rhamnosus GG powder and its characterization

This study investigated spray drying a method for microencapsulating Lacticaseibacillus rhamnosus GG using a gastrointestinal resistant composite matrix. An encapsulate composite matrix comprising green banana flour (GBF) blended with maltodextrin (MD) and gum arabic (GA). The morphology of resulted microcapsules revealed a near-spherical shape with slight dents and no surface cracks. Encapsulation efficiency and product yield varied significantly among the spray-dried microencapsulated probiotic powder samples (SMPPs). The formulation with the highest GBF concentration (FIV) exhibited maximum post-drying L. rhamnosus GG viability (12.57 ± 0.03 CFU/g) and best survivability during simulated gastrointestinal digestion (9.37 ± 0.05 CFU/g). Additionally, glass transition temperature (Tg) analysis indicated good thermal stability of SMPPs (69.3 – 92.9 ℃), while Fourier Transform infrared (FTIR) spectroscopy confirmed the structural integrity of functional groups within microcapsules. The SMPPs characterization also revealed significant variation in moisture content, water activity, viscosity, and particle size. Moreover, SMPPs exhibited differences in total phenolic and flavonoid, along with antioxidant activity and color values throughout the study. These results suggested that increasing GBF concentration within the encapsulating matrix, while reducing the amount of other composite materials, may offer enhanced protection to L. rhamnosus GG during simulated gastrointestinal conditions, likely due to the gastrointestinal resistance properties of GBF.

The effect of mesenchymal stem cell conditioned medium incorporated within chitosan nanostructure in clearance of common gastroenteritis bacteria in-vitro and in-vivo

Gastroenteritis infection is a major public health concern worldwide, especially in developing countries due to the high annual mortality rate. The antimicrobial and antibiofilm activity of human mesenchymal stem cell-derived conditioned medium (hMSCsCM) encapsulated in chitosan nanoparticles (ChNPs) was studied in vitro and in vivo against common gastroenteritis bacteria. The synthesized ChNPs were characterized using Zeta potential, scanning electron microscopy (SEM), and dynamic light scattering (DLS) techniques. HMSC-derived conditioned medium incorporated into chitosan NPs (hMSCsCM-ChNPs) composite was fabricated by chitosan nanoparticles loaded with BM-MSCs (positive for CD73 and CD44 markers). The antimicrobial and antibiofilm activity of composite was investigated against four common gastroenteritis bacteria (Campylobacter jejuni ATCC29428, Salmonella enteritidis ATCC13076, Shigella dysenteriae PTCC1188, and E. coli ATCC25922) in-vitro and in-vivo. Majority of ChNPs (96%) had an average particle size of 329 nm with zeta potential 7.08 mV. The SEM images confirmed the synthesis of spherical shape for ChNPs and a near-spherical shape for hMSCsCM-ChNPs. Entrapment efficiency of hMSCsCM-ChNPs was 75%. Kinetic profiling revealed that the release rate of mesenchymal stem cells was reduced following the pH reduction. The antibacterial activity of hMSCsCM-ChNPs was significantly greater than that of hMSCsCM and ChNPs at dilutions of 1:2 to 1:8 (P < 0.05) against four common gastroenteritis bacteria. The number of bacteria present decreased more significantly in the group of mice treated with the hMSCsCM-ChNPs composite than in the groups treated with hMSCsCM and ChNPs. The antibacterial activity of hMSCsCM against common gastroenteritis bacteria in an in vivo assay decreased from > 106 CFU/ml to approximately (102 to 10) after 72 h. Both in vitro and in vivo assays demonstrated the antimicrobial and antibiofilm activities of ChNPs at a concentration of 0.1% and hMSCsCM at a concentration of 1000 μg/ml to be inferior to that of hMSCsCM-ChNPs (1000 μg/ml + 0.1%) composite. These results indicated the existence of a synergistic effect between ChNPs and hMSCsCM. The designed composite exhibited notable antibiofilm and antibacterial activities, demonstrating optimal release in simulated intestinal lumen conditions. The utilization of this composite is proposed as a novel treatment approach to combat gastroenteritis bacteria in the context of more challenging infections.

Synthesis of Nano-aluminum Nitride powder at low temperature by Sol-gel method

In this paper, molecular-level mixed aluminum nitride has been prepared from aluminum sec-butyl alcohol, glucose, and urea by sol-gel processing. Then, the nano-aluminum nitride powder with uniform particle size distribution was obtained by carbothermal reduction nitridation reaction. The effects of different feed ratios, reaction temperatures, and holding times on the phase of AlN powder were systematically studied. The prepared nano-aluminum nitride powder has a uniform particle size and a near-spherical shape, and its grain size is approximately 20~30 nm. The preparation temperature in this method was significantly reduced from the same preparation method of aluminum nitride powder.

Chinese consumers’ attribute preference prediction for table grapes

This paper aims to understand intrinsic attribute preferences of Chinese consumers for table grapes, analyze the influencing factors, and build consumer preference prediction models. In this study, 4324 consumers from various regions of China were investigated. We analyzed consumer preferences and the influencing factors. Finally, binary logistic regression was used to construct prediction models of consumers’ intrinsic attribute preferences for table grapes. The results showed that grapes popular with Chinese consumers had fixed characteristics, including moderate size, spherical or near-spherical shape, purple-red color, strawberry flavor, light aroma, soft flesh and juicy, sweet taste, seedlessness, thin skin powder, and easy to peel. The results of the prediction models showed that age, annual consumption of grapes, and other factors of consumers had significant effects on consumer preferences. The prediction models achieved 80% accuracy in predicting consumer preferences for taste, seedless and peeling degrees. Analyzing the latest attribute preferences of Chinese table grapes, consumers can provide on the one hand, breeding direction reference for breeders, and on the other, marketing suggestions for marketers in the table grape industry. This study comprehensively investigated the intrinsic attribute preferences of Chinese table grape consumers, mastered the latest results of consumer preferences, added the indicators of the intrinsic attributes from the perspective of consumer demand, and conducted relatively more complete prediction research on the preferences of Chinese consumers.

Chemical composition and morphology of PM2.5 in a rural valley during Chinese New Year's Eve: Impact of firework/firecracker display

To study the effect of fireworks/firecrackers (FF) display on aerosol particles, the chemical composition and morphology of fine aerosol particles (PM2.5) collected in a rural valley of north China in the Chinese New Year's Eve (CNYE) were analyzed. The results showed that PM2.5 was much lower in the 2022 CNYE with little influence by FF due to the strict no-FF display policy for the 2022 Winter Olympic Games. In contrast, PM2.5 was significantly affected by FF display in the 2023 CNYE with the maximum hourly PM2.5 mass concentrations reaching 1200 μg m−3. The value was even much higher than that in near-by cities. Chemical analysis showed that organic matter (24.5 wt% of total PM2.5) was the most abundant in the CNYE, followed by K+ (15.3 wt%), SO42− (12.3 wt%), and Cl− (9.9 wt%). The mass concentrations of K+, Mg2+, Cu, Sr, and Ba were as 22.0 to 41.4 times as those before the CNYE. The concentrations of elemental carbon, Cl−, SO42−, and Ti were as 3.7 to 12.3 times as those before the CNYE. Further analysis by scanning electron microscope coupled with energy dispersive X-ray spectrometer revealed that carbonaceous particles in the CNYE contained more S, Cl, K and heavy metals compared with that before the CNYE. Most of the non-carbonaceous particles in the CNYE were K-rich, Mg-rich, Al-rich, and Ba-rich, with spherical and near-spherical shapes, which were much different from those before the CNYE with irregular shapes. The different morphologies of non-carbonaceous particles can have much different optical properties, which should be further evaluated. The results above suggested that the PM2.5 mass concentration in rural valleys in the CNYE was extremely high in a short time and more attention should be paid in future policy making to improve air quality.

Deformation versus Sphericity in the Ground States of the Lightest Gold Isotopes.

The changes in mean-squared charge radii of neutron-deficient gold nuclei have been determined using the in-source, resonance-ionization laser spectroscopy technique, at the ISOLDE facility (CERN). From these new data, nuclear deformations are inferred, revealing a competition between deformed and spherical configurations. The isotopes ^{180,181,182}Au are observed to possess well-deformed ground states and, when moving to lighter masses, a sudden transition to near-spherical shapes is seen in the extremely neutron-deficient nuclides, ^{176,177,179}Au. A case of shape coexistence and shape staggering is identified in ^{178}Au which has a ground and isomeric state with different deformations. These new data reveal a pattern in ground-state deformation unique to the gold isotopes, whereby, when moving from the heavy to light masses, a plateau of well-deformed isotopes exists around the neutron midshell, flanked by near-spherical shapes in the heavier and lighter isotopes-a trend hitherto unseen elsewhere in the nuclear chart. The experimental charge radii are compared to those from Hartree-Fock-Bogoliubov calculations using the D1M Gogny interaction and configuration mixing between states of different deformation. The calculations are constrained by the known spins, parities, and magnetic moments of the ground states in gold nuclei and show a good agreement with the experimental results.

Scalable production of wood carbon microspheres for high-efficiency carbon dioxide capture

Utilizing abundantly available biomass materials to prepare adsorbent substances is a simple and cost-effective method for CO2 adsorption, which, however, is often hampered by low adsorption capacity. Here, we demonstrate near-spherical active carbon (C-DWP/Zn) with high CO2 adsorption ability, employing delignification combination with ZnCl2 activation of natural wood powder. Removing lignin from wood cell walls facilitates easy absorption of Zn ions by the cellulose nanofibers (CNFs), thereby promoting micro/nano pores formation. Moreover, rapid dehydration of cellulose molecular chains alters the morphology of activated carbon, resulting in a transition from a granular to a near-spherical shape. Consequently, C-DWP/Zn with high specific surface area of 1769 m2 g−1, shows a significantly higher microporous volume than that of a control sample without delignification. The CO2 adsorption capacity of C-DWP/Zn, with values of 3.51 mmol g−1 and 5.12 mmol g−1 at 1 bar, 25 °C and 0 °C, respectively, is superior to that of commercial activated carbon. Attributable to its optimal micropore structure, C-DWP/Zn exhibits high CO2/N2 selectivity. Furthermore, the high carbon dioxide adsorption efficiency of C-DWP/Zn was maintained and the substance could be reused at least 20 times. Near-spherical active carbon adsorbents prepared from low-value wood powders, all featuring high CO2 adsorption performances, reasonable CO2/N2 selectivity, good recoverability, suitable heat of adsorption, and fast adsorption kinetics, which are promising candidates for practical CO2 adsorption.

Supercritical antisolvent-fluidized bed for the preparation of dry powder inhaler for pulmonary delivery of nanomedicine

The supercritical antisolvent-fluidized bed coating process (SAS-FB) shows great potential as a technique to manufacture dry powder inhaler (DPI) that incorporate nanodrugs onto micronized matrix particles, capitalizing on the merits of both nanoparticle and pulmonary delivery. In this study, naringin (NAR), a pharmacologically active flavonoid with low solubility and in vivo degradation issues, was utilized as a model active pharmaceutical ingredient to construct nanomedicine-based DPI through SAS-FB. It is showed that processed NAR exhibited a near-spherical shape and an amorphous structure with an average size of around 130 nm. Notably, SAS-FB products prepared with different fluidized matrices resulted in varying deposition patterns, particularly when mixed with a coarse lactose to enhance the fine particle fraction (FPF) of the formulations. The FPF was positively associated with specific surface area of the SAS-FB products, while the specific surface area was directly related to surface roughness and particle size. In vitro dissolution studies using simulated lung fluid revealed that the NAR nanoparticles coated on the products were released immediately upon contact with solution, with a cumulative dissolution exceeding 90% within the first minute. Importantly, compared to oral raw NAR, the optimized DPI formulation demonstrated superior in vivo plasmatic and pulmonary AUC0→∞ by 51.33-fold and 104.07-fold respectively in a Sprague-Dawley rat model. Overall, SAS- FB technology provides a practical approach to produce nanomedicine DPI product that combine the benefits of nanoparticles with the aerodynamics properties of inhaled microparticles.

A novel approach for enhancing fire suppression efficiency of dry powder extinguishant: From the synergistic effect of dawsonite

A novel superfine dry powder extinguishing agent (DW-SDE) was developed by combining dawsonite (NaAl(OH)2CO3, DW) with superfine ABC dry powder fire extinguishing agent (SDE). The micro-morphology of DW transforms into a near-spherical shape (D90 = 8.33 μm) under optimal conditions including a mass ratio of 1:10 for citric acid (ZS) to aluminum hydroxide, a reaction time of 8 h, and a reaction temperature of 150 °C. The D90 of DW-SDE is 11.20 μm which is less than that of SDE (D90 = 14.46 μm). The activation energy (E) of DW-SDE is lower (E = 102.0 kJ/mol) and the thermal decomposition of DW-SDE can absorb more heat (388.7 J/mg). Moreover, the flowability of DW-SDE is superior to that of SDE and commercial ABC dry powder extinguishing agent (CDE). Furthermore, the DW-SDE can completely extinguish a fire in 8.7 s at 0.6 MPa, which is 47.4% and 27.1% faster than that of CDE and SDE.

Quercetin and 5-Fu Loaded Chitosan Nanoparticles Trigger Cell-Cycle Arrest and Induce Apoptosis in HCT116 Cells via Modulation of the p53/p21 Axis.

Nanoparticles (NPs) are encapsulating agents that exist in the nanometer range. They can be classified into different classes based on their properties, shapes, or sizes. Metal NPs, fullerenes, polymeric NPs, ceramic NPs, and luminescent nanoporous hybrid materials are only a few examples. This study explored the anticancer potential of quercetin and 5-fluorouracil-encapsulated chitosan nanoparticles (CS-5-FU-QCT NPs). The nanoparticles were prepared by ionic gelation, and their efficacy and mechanism of action were examined. CS-5-FU-QCT NPs were characterized using dynamic light scattering (DLS), atomic force microscopy (AFM), UV-visible spectroscopy, and Fourier transform infrared spectroscopy (FTIR); cytotoxicity was analyzed using an MTT assay. Cells were treated with CS-5-FU-QCT NPs and incubated for 12, 24, and 36 h, and apoptosis analysis (using Annexin V/FITC), cell-cycle analysis, Western blotting, and confocal microscopic analysis were performed. Biophysical analysis revealed that the CS-5-FU-QCT NPs fall in the range of 300-400 nm with a near-spherical shape. The in vitro drug release profile indicates sustained release of drugs over a period of about 36 h. The cytotoxicity of CS-5-FU-QCT NPs was more prominent in HCT116 cells than in other cancer cells. This particular nanoformulation caused G0/G1 phase cell-cycle arrest in HCT116 cells and induced intracellular ROS generation, thereby causing apoptosis. It also downregulated Bcl2, cyclin D1, and Cdk4 and upregulated BAX, p53, and p21, causing cell-cycle arrest and apoptosis. In summary, CS-5-FU-QCT NPs hindered proliferation of HCT116 cells via ROS generation and altered the expression of key proteins in the p53/p21 axis and apoptotic machinery in a time-dependent manner.

Study on effect of transverse concentration gradients in pipeline on methane explosion characteristics

In this paper, we studied the effects of transverse concentration gradients on methane explosion characteristics using a fully-transparent pipeline and finally came to the following conclusions. The peak explosion overpressure changed in a waveform of “M” along different measuring points, but a set of non-equivalent concentration gradients maximized this peak value. Higher methane concentrations in the Q2 region could cause the secondary peak overpressure near the both ends of the pipe. In this process, the flame outside the pipe tends to form a near-spherical shape. However, at lower methane concentrations in the Q2 region, the secondary peak overpressure was only detected near the outlet. Its occurrence at different sites may relate to the turbulence effect heightened by concentration gradients. Besides, under the same gradient, the smallest propagation speed was measured on the right of the ignition source when the flame propagated fastest on the left, which was attributed to different inhibiting effects of reflected waves on flame propagation.

Fluorescent Pirfenidone-Cerium(III) nanocomplexes protect against radiation-induced pulmonary fibrosis and inhibit tumor cell growth

Radiation-induced pulmonary fibrosis (RIPF) is a common adverse effect of thoracic radiation therapy. Although pirfenidone is approved for treating pulmonary fibrosis, its utility is limited by its short half-life and ability to scavenge reactive oxygen species (ROS). Thus, a nanoscale complexes of cerium(III), 10-carboxyl-pirfenidone, and 1,10-phenanthroline (NPs Ce(phen)Pirf3) was developed to prevent RIPF in a mouse model. NPs Ce(phen)Pirf3 was successfully prepared using a simple moderate solvothermal method and characterized using FTIR, electrospray ionization MS, 1H nuclear magnetic NMR, and transmission electron microscopy. The cerium(III) nanocomplexes exhibited a near-spherical shape and dissolved in water with a diameter of ∼125.2 nm, as characterized by dynamic light scattering. Compared with pirfenidone, NPs Ce(phen)Pirf3 with blue fluorescence exhibited prolonged retention times with thoracic-specific accumulation in vivo. Mice received 15 Gy gamma-ray treatment on the thorax with or without NPs Ce(phen)Pirf3 or pirfenidone administration. NPs Ce(phen)Pirf3 improved lung function, alleviated radiation-induced pathological changes in the lung tissues, and reduced collagen deposition 16 weeks after radiation. Our results from in vivo and in vitro experiments demonstrated that NPs Ce(phen)Pirf3 increased the ROS-scavenging ability. Additionally, NPs Ce(phen)Pirf3 regulated epithelial-mesenchymal transition (EMT)-related proteins, including up-regulate E-cadherin and down-regulate N-cadherin, α-SMA, and TGF-β1 in RLE-6TN cells, which suggested NPs Ce(phen)Pirf3 may alleviate RIPF by inhibiting EMT. Finally, NPs Ce(phen)Pirf3 also inhibited the growth of thoracic tumor cells in mice. NPs Ce(phen)Pirf3 had a protective role against RIPF and antitumor effects, suggesting that they are a promising therapy for thoracic radiation-induced RIPF.

Enhanced thermal conductivity of Si3N4 ceramics through pyrolytic carbon prepared by gel casting using DMAA

To reduce the lattice oxygen content of Si3N4 green bodies, samples were prepared using an N,N-dimethylacrylamide (DMAA) system. The endothermic and exothermic peaks are related to the decomposition of organic matter and the reaction between pyrolytic carbon and impurity oxides in the sintering process. Multi-step heat preservation during the thermal degreasing process reduced the carbon content and defects. The α→β phase transformation and aspect ratio of grains changed from 89.2% to 4.84:1 at 1640 °C to 96.3% and 7.80:1 at 1700 °C, respectively. The relative density, hardness, fracture toughness, and thermal conductivity of the Si3N4 samples reached 98.5%, 1353 HV, 8.51 MPa·m1/2, and 97.1 W·m−1·K−1, respectively. Pyrolytic carbon can react with SiO2, which reduces the content of the glass phase in the green body and affects the dissolution and precipitation process and lattice oxygen content. In the structure of the Si3N4 sample, carbon particles with sizes of 100–500 nm and near-spherical shapes were observed. Intergranular-phase YMgSi2O5N was formed during the sintering process, which was conducive to improving the thermal conductivity. This article uses lower temperature and no pressure conditions to prepare Si3N4 ceramics, which can provide reference for batch and low-cost production.

Scaling of the permanent electric dipole moment in isolated silicon clusters with near-spherical shape.

In silicon clusters a structural transition from prolate to near-spherical structures takes place at a size of about 25-30 atoms. While some of the prolate clusters are very polar, there has been no experimental evidence of the presence of dipole moments in larger silicon clusters with near-spherical shape. By means of electric molecular beam deflection experiments at cryogenic temperatures, it was possible to prove for the first time that SiN clusters with more than N = 30 atoms are also polar. Interestingly, the dipole moment per atom for clusters in the range between 30 and 80 or 90 atoms is almost constant and amounts to 0.02 D. This unusual behaviour manifests in effective polarizabilities increasing linearly with cluster size. The dipolar contribution to the polarizability means that SiN clusters with N = 80 atoms can be polarized more than twice as well as a correspondingly small sphere with the dielectric properties of bulk α-Si. This finding is analysed with quantum chemical calculations concerning the geometric structure as well as the charge distribution and is related to the dielectric behaviour of polar semiconductor nanocrystals.

Biologically Synthesized Rosa rugosa-Based Gold Nanoparticles Suppress Skin Inflammatory Responses via MAPK and NF-κB Signaling Pathway in TNF-α/IFN-γ-Induced HaCaT Keratinocytes.

Nanotechnology-applied materials and related therapeutics have gained attention for treating inflammatory skin diseases. The beach rose (Rosa rugosa), belonging to the family Rosaceae, is a perennial, deciduous woody shrub endemic to northeastern Asia. In this study, R. rugosa-based gold nanoparticles (RR-AuNPs) were biologically synthesized under optimal conditions to explore their potential as anti-inflammatory agents for treating skin inflammation. The synthesized RR-AuNPs were analyzed using field emission-transmission electron microscopy, energy-dispersive X-ray spectrometry, selected-area electron diffraction, and X-ray diffraction. The uniformly well-structured AuNPs showed near-spherical and polygonal shapes. Cell viability evaluation and optical observation results showed that the RR-AuNPs were absorbed by human keratinocytes without causing cytotoxic effects. The effects of RR-AuNPs on the skin inflammatory response were investigated in human keratinocytes treated with tumor necrosis factor-α/interferon-γ (T + I). The results showed that T + I-stimulated increases in inflammatory mediators, including chemokines, interleukins, and reactive oxygen species, were significantly suppressed by RR-AuNP treatment in a concentration-dependent manner. The western blotting results indicated that the RR-AuNP-mediated anti-inflammatory effects were highly associated with the suppression of inflammatory signaling, mitogen-activated protein kinase, and nuclear factor-κB. These results demonstrate that plant extract-based AuNPs are novel anti-inflammatory candidates for topical application to treat skin inflammation.

Powder preparation during ball milling and laser additive manufacturing of aluminum matrix nanocomposites: Powder properties, processability and mechanical property

• Nanocomposite powder for additive manufacturing was economically prepared. • The nanocomposite powder showed near-spherical shape and high flowability. • Nano-TiB 2 particles was uniformly dispersed on the surface of aluminum powder. • The optimal nanocomposite powder exhibited good processability. • The as-fabricated nanocomposite exhibited favorable mechanical property. The additive manufacturing method of laser powder bed fusion (LPBF) has a great potential in producing high-performance metal matrix nanocomposite components. However, nanocomposite powder feasible for LPBF is still limited in availability. In this work, AlSi10Mg powder containing 2 wt% TiB 2 nanoparticles was prepared by ball milling of the constituent powder to meet the following two criteria: (i) a uniform dispersion of nanoparticles on the surface of the micro powder and (ii) a high flowability of the produced nanocomposite powder. The evolution of the powder properties with the milling dose was studied. The results indicated that with the increase of milling dose, the nano-TiB 2 particles were dispersed uniformly but the Al matrix gradually underwent plastic deformation. Under optimized milling conditions, the aluminum matrix nanocomposite powder showed a small mean particle size, narrow size distribution, smooth surface, and a spherical shape with uniformly dispersed nanoparticles. These properties are beneficial for a good LPBF processability. During LPBF process, a favorable forming quality of the optimized nanocomposite powder was evident. A mechanical characterization demonstrated an outstanding tensile strength of ∼ 450 MPa and excellent ductility of ∼ 7.2 % for the built parts.