Reduction In Surface Area Research Articles

Comparative efficacy of autologous platelet rich plasma and conventional dressing in the management of chronic ulcers

Background: Chronic ulcers pose a major global healthcare challenge. The use of platelet-rich plasma (PRP) for treating these wounds has garnered interest because of its potential healing benefits. Objective were to determine the effect of autologous PRP therapy on the percentage of surface area reduction/healing in chronic ulcers. Methods: This randomized controlled trial was conducted at the department of general surgery of M.M. institute of medical sciences and research (M.M.I.M.S.R.) Mullana, Ambala from May 1, 2023, to April 30, 2024. Patients aged 18-80 years of either gender with chronic ulcers were enrolled. Patients were randomly allocated to the PRP group and control group. PRP group was administered autologous PRP once in two weeks for 6 weeks after debridement, while for the control group conventional saline dressings were done after debridement. Final assessment was done at 8 weeks. Results: Of the 60 patients, the mean age was 53.90±11.23 years. There were 49 (82%) males and 11 (18%) females. At 8 weeks, the PRP group achieved 83.78% (SD=2.99) reduction in surface area of ulcers, whereas the control group had a 57.78% (SD=1.32) reduction in surface area of ulcers, with a p=0.0000 indicating a significant difference. The small sample size and 56-day follow-up period are insufficient to assess long-term treatment effects. Conclusions: A better outcome of PRP was observed compared to conventional dressing in patients with chronic non-healing ulcers.

SnO2QDs: Photophysical properties, photocatalytic activity, mineralization financial cost and recycling process during industrial effluent treatment

This study investigates the synthesis, characterization, and photocatalytic performance of pure and titanium-doped tin dioxide quantum dots (SnO2QDs) prepared via a sonochemical method. The structural and morphological properties were thoroughly examined using XRD, FTIR, SEM-EDX, HRTEM, UV-DRS, and BET surface area analysis. XRD confirmed the formation of tetragonal SnO2 with high phase purity and average crystallite sizes of 2.95 nm for SnO2QD1 (calcined at 270 °C) and 8.36 nm for SnO2QD2 (calcined at 480 °C). Titanium doping was achieved without altering the SnO2 crystalline structure, as evidenced by FTIR spectra showing characteristic vibrational modes and hydroxyl groups. HRTEM images revealed spherical nanoparticles with diameters of 3.2 nm for SnO2QD1 and 9.7 nm for SnO2QD2, supported by SAED patterns confirming their polycrystalline nature. The photocatalytic efficiency was evaluated through the degradation of Reactive Yellow 145 dye under Xenon lamp irradiation. SnO2QD1 exhibited superior photocatalytic activity with a rate constant (k) of 6.94 × 10−3 s−1, achieving 80 % dye degradation in 105 min, compared to SnO2QD2 with a k of 4.50 × 10−3 s−1 and 83 % degradation in 120 min. Titanium doping further enhanced the photocatalytic performance, with SnO2QDT1 (1 % Ti) showing a k of 9.89 × 10−3 s−1 and 80 % degradation in just 90 min, three times more efficient than SnO2QDT2 (9 % Ti). BET analysis indicated a significant reduction in surface area with increased calcination temperature, from 154 m2/g for SnO2QD1 to 86 m2/g for SnO2QD2. The bandgap energies, determined via UV-DRS, were 3.30 eV for SnO2QD1 and 3.34 eV for SnO2QD2, slightly reduced in Ti-doped samples, enhancing visible light absorption. The SnO2QDs demonstrated excellent recyclability, maintaining photocatalytic activity over eight reuse cycles. Economic analysis based on Saudi Arabian electricity tariffs highlighted the cost-effectiveness of SnO2QD1, offering a 5.2 % reduction in energy consumption compared to SnO2QD2. These findings position SnO2QDs as highly efficient and sustainable photocatalysts for industrial wastewater treatment applications.

Transvaginal cervical cerclage – How well do surgeons assess their own procedures?

IntroductionIn women with cervical incompetence, transvaginal cerclage may help prevent preterm birth. However, training for this procedure poses challenges due to the low number of cases and difficulties in visualizing the operative field. Furthermore, the objective criteria for a successful cerclage procedure are not well-described. Quality assessment relies heavily on self-assessment rather than objective criteria and feedback. To address this issue, training on a simulator may offer a solution. We aimed to objectively assess surgical performance and compare it to the self-assessed performance in transvaginal cerclage procedures. Materials and methodsDuring the Nordic Federation of Obstetrics and Gynecology (NFOG) congress in 2023, surgeons proficient in transvaginal cerclage procedures performed a transvaginal cerclage on a simulator. To compare the observed and self-assessed outcomes we obtained measurements on the cerclage height and number of bites from the detachable cervix, and from computed tomography scans we analyzed suture bite depth, reduction of cervix surface area, and whether cerclages had perforated the cervical canal. The same outcomes were self-assessed by each participant after the cerclage procedure. We visualized the continuous paired data in a Bland-Altman plot and compared these data with a paired t-test. Paired binary data was analyzed using McNemars test. Results29 participants from eight different nationalities performed one transvaginal cerclage each. The mean height of the cerclage was 26.8 mm (SD 9 mm) and mean depth was 6.5 mm (SD 1.9 mm) across a mean of 4.1 (SD 0.8) bites. The mean reduction of the cervix surface area was 7.6 % (SD 5.9 %). Two sutures perforated the cervical canal. The participants significantly underestimated the height of their cerclage with a mean difference of 6.0 mm (95 % CI 2.1–9.9), (p 0.002), between the observed and the self-assessed height, but otherwise revealed good self-assessment of their performed procedure. ConclusionsOverall, the experienced cerclage surgeons showed a genuine insight into their surgical performance of a transvaginal cerclage. These results could warrant development of a procedural guidelines with objective measures, now reassured that surgeons are capable of self-assessing their procedures.

Silane functionalization of titania-graphene oxide nanocomposite for superior anticorrosion polyurethane coatings on steel

This research investigated the enhancement of anti-corrosion properties in polyurethane (PU) coatings on steel substrates through the Silane (N-(2-Aminoethyl)-3-aminopropyltrimethoxysilane) functionalization of Graphene Oxide (GO) with Titania (TiO₂) nanoparticles. Comprehensive characterization techniques, including Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), Thermogravimetric analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray diffraction analysis (XRD), Brunauer-Emmett-Teller (BET), and electrochemical analyses, confirmed the effective integration of TiO₂ within GO layers. The SEM and TEM analyses showed uniform dispersion of TiO₂ nanoparticles, while TGA indicated improved thermal stability of the functionalized GO-TiO2 (fGO). FTIR and XRD analyses verified the composite's successful chemical bonding and structural integrity. BET analysis revealed a specific surface area and pore volume reduction from 505.540 m²/g and 0.867 cc/g for GO to 211.622 m²/g and 0.708 cc/g for fGO, respectively. The enhancement in anti-corrosion properties can be attributed to the uniform dispersion of TiO₂ nanoparticles within the GO matrix, which increases the coating's barrier properties by filling pores and voids. This prevents electrolyte penetration and enhances adhesion to the steel substrate, inhibiting corrosion. Electrochemical analysis demonstrated excellent corrosion resistance of fGO-modified PU coatings, with a maximum observed resistance of 0.821 TΩ.cm2. Salt spray tests further validated these findings, showing delayed and reduced corrosion due to the protective layer formed by fGO. These results highlight the potential of fGO-modified PU coatings as advanced protective materials for steel structures in corrosive environments.

Abstinence from cocaine self-administration promotes microglia pruning of astrocytes which drives cocaine-seeking behavior.

Rodent drug self-administration leads to compromised ability of astrocytes to maintain glutamate homeostasis within the brain's reward circuitry, as well as reductions in surface area, volume, and synaptic colocalization of astrocyte membranes. However, the mechanisms driving astrocyte responses to cocaine are unknown. Here, we report that long-access cocaine self-administration followed by prolonged home cage abstinence results in decreased branching complexity of nucleus accumbens astrocytes, characterized by the loss of peripheral processes. Using a combination of confocal fluorescence microcopy and immuno-gold electron microscopy, we show that alterations in astrocyte structural features are driven by microglia phagocytosis, as labeled astrocyte membranes are found within microglia phagolysosomes. Inhibition of complement C3-mediated phagocytosis using the neutrophil inhibitory peptide (NIF) rescued astrocyte structure and decreased cocaine seeking behavior following cocaine self-administration and abstinence. Collectively, these results provide evidence for microglia pruning of accumbens astrocytes across cocaine abstinence which mediates cocaine craving.

Functionalization of pyrolyzed hydrochar with nitrogen containing deep eutectic solvent for carbon capture at low and high pressure

The purpose of this research is to evaluate the effectiveness of pyrolyzed hydrochar functionalized with nitrogen containing deep eutectic solvent (DES) in the absorption of CO2 under low- and high-pressure conditions. Pyrolyzed hydrochars were synthesized by hydrothermally carbonizing pine at the temperature of 200°C and 260°C, followed by pyrolysis at 600°C. These pyrolyzed hydrochars were impregnated with 3 different nitrogen containing DES namely choline chloride: urea, choline chloride: glycerol, and tetrabutylammonium bromide: glycerol all in 1:2 molar ratio. It was found that the functionalized pyrolyzed hydrochars were enhanced with nitrogen and oxygen functionalities (N-H, C-N, and CO). The results also show a substantial reduction in surface area for the functionalized pyrolyzed hydrochars, ranging from 10.19 to 227.74 m2g−1, compared to the surface areas of pyrolyzed hydrochars of 306–337 m2g−1. On the other hand, an increase in N content up to 38 % was identified after functionalization of pyrolyzed hydrochars. Upon conducting CO2 uptake at low (0.1–1 bar) and high (2.5–3.5 bar) pressure, the functionalized pyrolyzed hydrochars exhibited an CO2 uptake of up to 9.5 mmol/g at high pressure, which was attributed to the increased total nitrogen content, enhanced surface functionalities, and available micropore volume. The low-pressure isotherm for functionalized pyrolyzed hydrochars showed Langmuir-type isotherm, suggesting a monolayer adsorption. In contrast, the high-pressure isotherms were better fitted to the Freundlich isotherm, suggesting a multilayer adsorption behavior. It was concluded that the enhanced CO2 uptake is the result of the combined impact of increased surface functionalities and porosity, which results in improved physical and chemical adsorption mechanisms at the high pressure.

A comprehensive analysis of new particle formation across the northwest Atlantic: Analysis of ACTIVATE airborne data

New particle formation (NPF) is a critical source of particles and cloud condensation nuclei, yet there are scarce vertically-resolved measurements addressing NPF across different seasons in marine regions. This study leverages a multi-season set of airborne data from the NASA ACTIVATE mission between 2020 and 2022 to examine NPF characteristics over the northwest Atlantic ranging from the polluted U.S. East Coast to as far downwind (>1000 km) as Bermuda. Using the number concentration ratio above 3 and 10 nm (N3:N10) as a NPF indicator, we observe the highest ratios in the coldest months and comparable ratios over Bermuda relative to the U.S. East Coast. Within seasons, the highest and lowest ratios are found immediately above cloud tops and at the lowest possible flight altitudes (∼150 m above sea level), respectively. The ratio of (N3-N10)/N3 ranges from 0.16 to 0.29 depending on altitude, proximity to clouds, and season. The N3:N10 and (N3-N10)/N3 ratios increase with altitude up to as high as 9 km, with a case study showing favorable conditions around relatively thicker and precipitating cloud systems presumably due to high actinic fluxes and reduced aerosol surface area. Regression modeling reveals that increased N3:N10 is influenced most by reductions in temperature, relative humidity, and aerosol surface area. This work emphasizes the importance of both NPF in remote marine regions like Bermuda and vertical heterogeneity that exists in its contribution to aerosol and cloud condensation nuclei number budgets.

PSVII-5 Heat shock protein 70 gene expression and association with morphometric and heat tolerance traits in three plumage colors of Noiler chicken exposed to acute heat stress

Abstract Heat stress is one of the most difficult climatic conditions chickens faces and is a direct result of climate change. It is important to research poultry thermotolerance because it may help find genetic lines resistant to heat stress. This study investigated the influence of plumage colors on heat shock protein 70 gene expression in Noiler chickens exposed to acute heat stress. Noiler is a dual-purpose breed developed for smallholder poultry production in Nigeria. A total of 150 birds of three plumage colors (black, brown and white) of mixed sexes were used for the experiment. The birds were raised in deep litter house separated into six groups of 25 birds each and fed with commercial broiler diets from 0-8 wk and broiler finisher diets from 8 to 12 wk old. The birds were shared into treatments in 3 x 2 x 2 factorial arrangements with 3 plumage colors (black, brown, white), two temperature regimens (Control/thermoneutral, Heat stress) and sex of birds (male, female). The heat stressed birds were exposed to 41oC for 8 h from 0600 h to 1400 h for 7 d while control group maintained a thermoneutral temperature range of 30 oC to 32 oC for the same period. At 13 wk old, two birds were selected per treatment, slaughtered and the spleen removed and stored in RNA later for heat shock protein (HSP) 70 gene expression. Data collected were analyzed with Microsoft excel code for fold expression of HSP70 gene while GLM procedure in SAS was used to determine difference in expression of gene. The relative expression of HSP70 brown plumage was greater, upregulated compared with black and white. White plumage birds in control/thermoneutral group were significantly greater in HSP70 expression than other plumage colors and heat stressed birds. Association of HSP70 delta threshold cycle (DCT) values with morphometric and heat tolerance traits were investigated (Figure 1). High negative correlations emerged between HSP70DCT expression and body weight (-0.65), body temperature (-0.73) with moderate positive correlation for rectal temperature (0.55) in black birds (Table 1). HSP70 DCT positively correlated with body weight (0.70), breast/leg circumferences but negatively with wing length, suggesting reduced surface area during heat stress and a supportive role in maintaining protein integrity (Figure 2). For white Noiler birds, HSP70DCT associated negatively with body weight (-0.94) and positively with rectal temperature during heat stress (Table 2). Thermoneutral birds were positively correlated with heat tolerance traits except temperature while heat stressed birds showed low positive correlation with respiratory and pulse rates and very low positive relationship with body and rectal temperatures (Table 4). Sex-based differences emerged, with potential compromise between HSP70-mediated growth/composition in males versus muscle maintenance in females, although leg length/circumference showed shared developmental regulation (Figure 3, Table 3). These findings highlight HSP70’s versatile roles in systemic heat tolerance mechanisms influenced by plumage color, temperature regime and sex.

XCT images-based modeling for elucidating electrochemical inert phase-dependent multiscale electrode kinetic behaviors

The electrochemically inert phase (EIP) within the electrode is formed by the combination of carbon black and binder, characterized by a highly heterogeneous spatial distribution and structural morphology. This heterogeneity impairs electrode performance under varying discharge rates and temperatures. In this study, X-ray computed tomography is employed to image the original electrode. The resulting grayscale images are digitally processed to reveal the two-dimensional (2D) and three-dimensional (3D) features of the EIP morphology, thereby providing a design window to understand the influence of EIP morphology. The physical structure characterization indicates that, compared to bulk-like EIP (B-EIP), film-like EIP (F-EIP) tends to cover the active surface of the active material (AM), exacerbating the heterogeneity of the lithiation reactions within the electrode. The reduction in the AM active surface area correlates the state of lithiation (SOL) of particles with their active specific surface area (αa). At low temperatures, the temperature sensitivity of electrodes intensifies the risk of αa loss, promoting heterogeneous reaction transfer between particles. The Biot number (Bi) is used to evaluate the competing mechanisms between interfacial reactions and bulk diffusion within particles. In electrodes with a high EIP content, the reaction rate at the particle/electrolyte interface is accelerated, causing particle performance to be dominated by interfacial reactions. Finally, the electrochemistry and heat generation from the particle-level to the electrode-level in thicker electrodes are examined. It demonstrates that ion diffusion in the pore controls interfacial reactions and heat transport behavior. Aggregated high-flux reactions and localized hot spots exacerbate the heterogeneous degradation and side reactions within the electrode.

Subtyping drug-free first-episode major depressive disorder based on cortical surface area alterations

BackgroundMajor depressive disorder (MDD) is recognized as a complex and heterogeneous metal illness, characterized by diverse clinical symptoms and variable treatment outcomes. Previous studies have repeatedly reported alterations in brain morphology in MDD, but findings vary across sample characteristics. Whether this neurobiological substrate could stratify MDD into more homogeneous clinical subgroups thus improving personalized medicine remains unknown. MethodsWe included 65 drug-free patients with first-episode MDD and 66 healthy controls (HCs) and collected their structural MRI data. We performed the surface reconstruction and calculated cortical surface area using Freesurfer. The surface area of 34 Gy matter regions in each hemisphere based on the Desikan-Killiany atlas were extracted for each participant and subtyping results were obtained with the Louvain community detection algorithm. The demographic and clinical characteristics were then compared between MDD subgroups. ResultsTwo subgroups defined by distinct patterns of cortical surface area were identified in first-episode MDD. Subgroup 1 exhibited a significant reduction in surface area across nearly the entire cortex compared to subgroup 2 and HCs, whereas subgroup 2 demonstrated increased surface area than HCs. Further, subgroup 1 exhibited a higher proportion of females, and higher severity of anxiety symptoms compared to subgroup 2. LimitationsThe relatively small sample size. ConclusionsThis study identified two neurobiologically subgroups with distinct alterations in cortical surface area among drug-free patients with first-episode MDD. Our results highlight the promise of in delineating morphological heterogeneity within MDD, particularly in relation to the severity of anxiety symptoms.

Formation Characteristics of Pt-Ni Alloy Nanoparticles Fabricated by Nanolamination of Atomic Layer Deposition in Hydrogen.

Forced-flow atomic layer deposition nanolamination is employed to fabricate Pt-Ni nanoparticles on XC-72, with the compositions ranging from Pt94Ni6 to Pt67Ni33. Hydrogen is used as a co-reactant for depositing Pt and Ni. The growth rate of Pt is slower than that using oxygen reactant, and the growth exhibits preferred orientation along the (111) plane. Ni shows much slower growth rate than Pt, and it is only selectively deposited on Pt, not on the substrate. Higher ratios of Ni would hinder subsequent stacking of Pt atoms, resulting in lower overall growth rate and smaller particles (1.3-2.1nm). Alloying of Pt with Ni causes shifted lattice that leads to larger lattice parameter and d-spacing as Ni fraction increases. From the electronic state analysis, Pt 4f peaks are shifted to lower binding energies with increasing the Ni content, suggesting charge transfer from Ni to Pt. Schematic of the growth behavior is proposed. Most of the alloy nanoparticles exhibit higher electrochemical surface area and oxygen reduction reaction activity than those of commercial Pt. Especially, Pt83Ni17 and Pt87Ni13 show excellent mass activities of 0.76 and 0.59AmgPt -1, respectively, higher than the DOE target of 2025, 0.44AmgPt -1.

Effect of surface area on the wear properties of Al-based automotive alloy and the role of Si at eutectic level

The efficiency of an engine material is closely correlated with its surface area. In order to investigate wear properties, effect of surface contact area as well as silicon addition at the eutectic level of Al-Cu-Mg alloy has been studied. This test is performed under room atmosphere and dry sliding conditions using a standard pin-on-disk apparatus. Weight reduction method is adopted to measure the wear rate in microns to get more accurate results. A load varying from of 5 to 50 N and a constant sliding speed of 0.77 ms−1 are maintained throughout the test. The test results show that a lower contact surface area has a negative impact on the wear properties having higher wear rate, while the coefficient of friction of the alloy and Si addition into the alloy improve the properties to some extent. Reduction of the contact surface area increases the unit pressure and decreased material volume causes softening of the alloy matrix, resulting in a higher wear rate and coefficient of friction. The Si addition offers such an improvement mostly for an increase in strength via the Si-rich intermetallic formation. A microstructural study confirms a lower abrasive wear with a minor plastic deformation on the worn surfaces of Si added alloy and wear with higher contact surface. The Si-added alloys contain the fine and strong Si-rich intermetallic, which are responsible for such a smooth worn surface.

Cadmium-induced pancreatic toxicity in rats: comparing vitamin C and Nigella sativa as protective agents: a histomorphometric and ultrastructural study

The study aimed to assess the toxic effect of cadmium (Cd) on the exocrine and endocrine functions of pancreas, the changes in pancreatic tissue after Cd withdrawal, and the protective effects of vitamin C (VC) and Nigella sativa (NS) against Cd-induced damage. Rats were assigned to: control, Cd-treated (0.5 mg/kg/d intraperitoneal [IP] injection), VC and Cd-treated (receiving 100 mg/kg/d VC orally and Cd concomitantly), NS and Cd-treated (receiving 20 mg/kg/d NS and Cd, simultaneously), and Cd withdrawal (receiving Cd for 30 d then living free for recovery for other 30 d). Blood samples were collected and post-sacrifice pancreatic specimens were processed for light and electron microscope study. Quantitative analyses of pancreatic collagen area%, pancreatic islet parameters, β cell density, and insulin immunoexpression were done. Fasting blood glucose was significantly increased in Cd-treated and Cd-withdrawal groups, while co-treatment with VC and NS caused significant reductions (p < 0.05). Cd-induced extensive degenerative changes in pancreatic acini and islets at light and ultrastructure levels. Obvious fibrosis and congestion of blood vessels were noticed. Significant reductions in pancreatic islet number, volume, and surface area and diminished beta cell count and insulin immunoexpression were observed. After withdrawal of Cd, the whole pancreatic tissue still showed a serious impact. Concomitant treatment with VC or NS obviously reduced these degenerative changes and significantly improved pancreatic islet parameters and insulin immunoexpression. VC showed a better amendment than NS, but this difference was statistically insignificant. Therefore, VC and NS could be used as prophylactic agents that lessen Cd consequences on the pancreas.

Causal effects of sepsis on structural changes in cerebral cortex: A Mendelian randomization investigation.

Previous research has shown a strong correlation between sepsis and brain structure. However, whether this relationship represents a causality remains elusive. In this study, we employed Mendelian randomization (MR) to probe the associations of genetically predicted sepsis and sepsis-related death with structural changes in specific brain regions. Genome-wide association study (GWAS) data for sepsis phenotypes (sepsis and sepsis-related death) were obtained from the IEU OpenGWAS. Correspondingly, GWAS data for brain structural traits (volume of the subcortical structure, cortical thickness, and surface area) were derived from the ENIGMA consortium. Inverse variance weighted was mainly utilized to assess the causal effects, while weighted median and MR-Egger regression served as complementary methods. Sensitivity analyses were implemented with Cochran Q test, MR-Egger regression, and MR-PRESSO. In addition, a reverse MR analysis was carried out to assess the possibility of reverse causation. We identified that genetic liability to sepsis was normally significantly associated with a reduced surface area of the postcentral gyrus (β = -35.5280, SE = 13.7465, P = .0096). The genetic liability to sepsis-related death showed a suggestive positive correlation with the surface area of fusiform gyrus (β = 11.0920, SE = 3.6412, P = .0023) and posterior cingulate gyrus (β = 3.6530, SE = 1.6684, P = .0286), While it presented a suggestive negative correlation with surface area of the caudal middle frontal gyrus (β = -11.4586, SE = 5.1501, P = .0261) and frontal pole (β = -1.0024, SE = 0.4329, P = .0206). We also indicated a possible bidirectional causal association between genetic liability to sepsis-related death and the thickness of the transverse temporal gyrus. Sensitivity analyses verified the robustness of the above associations. These findings suggested that genetically determined liability to sepsis might influence the specific brain structure in a causal way, offering new perspectives to investigate the mechanism of sepsis-related neuropsychiatric disorders.

Optimizing nickel-aluminium layered double hydroxides for supercapacitors: The role of 3D structural assembly

Nickel-aluminium layered double hydroxides (NiAl-LDHs) have emerged as promising electrode materials for supercapacitors (SCs) due to their inherently high specific surface area and theoretical specific capacitance, which are primarily attributed to the rapid pseudocapacitive response at the surface. However, NiAl-LDHs typically form agglomerated nanosheets, leading to a significant reduction in specific surface area, which is crucial for enhancing the number of active sites and improving the capacitive properties of the materials. To overcome this limitation, 2D nanostructures were assembled into 3D architectures by synthesizing NiAl-LDHs with distinct morphologies in a one-step hydrothermal process using an alkaline agent (NH4F). This approach resulted in the formation of 3D NiAl-LDH/HN4F structures, which exhibit a larger contact area and a greater number of redox-active sites. Consequently, the 3D NiAl-LDH/HN4F electrodes demonstrated a significantly higher specific surface area, leading to remarkable improvements in specific capacitance (1219 ± 30F g−1) and energy density (61 ± 1 Wh kg−1) compared to their 2D counterparts. This structural enhancement increases both the surface area and active site density while providing a new framework for designing high-performance LDH-based electrodes.

Role of MgO in Al2O3‐supported Fe catalysts for hydrogen and carbon nanotubes formation during catalytic methane decomposition

AbstractCatalytic methane decomposition is a promising technology for reducing the reliance on fossil fuels and mitigating the effects of climate change by producing clean hydrogen and value‐added carbon without the emission of greenhouse gases. The aim of the study was to investigate the use of Al2O3‐modified MgO doped iron‐based catalysts for the catalytic decomposition of methane. The catalysts were synthesized using the impregnation method and characterized using various analysis techniques, including Brunauer, Emmett, and Teller, temperature programmed reduction, temperature programmed oxidation, X‐ray diffraction, thermal gravimetric analysis, Raman, scanning electron microscopy, and transmission electron microscopy. The activity of the synthesized catalysts was tested in a packed‐bed reactor with a gas flow rate of 20 mL/min at a temperature of 800°C. The investigation focuses on the influence of incorporating magnesium into alumina catalysts with MgO concentration ranging from (20%–70%), where higher magnesium levels improve catalytic activity by creating more active sites, positively impacting methane decomposition. Enhanced catalyst reducibility and increased particle dispersion lead to improved catalytic properties despite the reduced surface area. The FA70M and FA63M catalysts exhibited almost the same catalytic characteristics and the highest stability and methane conversion among the catalysts investigated, reaching 87% and 85% at 800°C for 120 min. Moreover, both catalysts showed hydrogen yields of 86% and 85%, respectively. The introduction of MgO further increased the total carbon yield from 103% with FA and 39% for FM to 114% and 120% for the respective catalysts (FA70M and FA63M). During the methane decomposition reaction, carbon nanotubes of varying diameters were produced. Higher iron loading resulted in a positive trend.

Reduced Surface Area for the Oxygen Reduction Reaction in Porous Electrode via Electrical Conductivity Relaxation.

Oxygen reduction reaction (ORR) performance of porous electrode is critical for solid oxide fuel cells (SOFCs). However, the effects of gas diffusion on the ORR in porous media need further investigation, although some issues, such as nonthermal surface oxygen exchange, have been attributed to gas diffusion. Herein, La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) with various porosity, pore radii and gas permeability were investigated via the electrical conductivity relaxation method and analysed using the distributed of characteristic time (DCT) model. The ORR is revealed with three characteristic times, which are gas diffusion, oxygen exchange via the surface corresponding to small pores, and oxygen exchange to large pores. Gas diffusion delays the oxygen surface exchange reaction, resulting in very low chemical oxygen surface exchange coefficient compared with that obtained with dense sample under the assumption that all the surfaces are active for the ORR. Reduced surface area is thus defined to quantitatively represent the gas diffusion effects. The reduced surface area increases with increasing gas permeability, demonstrating the importance of electrode engineering for fast gas transport. Moreover, reduced surface area is suggested for replacing the specific surface area to calculate the electrode polarization resistance using the ALS model.

Repurposing Cotton Gin Trash for Cellulose Nanofibril-Silver Hybrid and Ultralight Silver-Infused Aerogel.

Cellulose nanofibril-silver (CNF-Ag) hybrid and ultralight silver-infused aerogel were produced using cotton gin trash (CGT), an abundant agro-waste material. This repurposing of CGT was achieved by exploiting its potential for CNF extraction and the in situ synthesis of silver nanoparticles (Ag NPs). CNFs were extracted from CGT through a mechanical shearing process. These CNFs served as a multifunctional nanotemplate for the controlled reduction of Ag ions, efficient nucleation, and stabilization of NPs, resulting in the production of a high concentration of Ag NPs (ca. 19 wt %) within the CNFs. Transmission electron microscopy images of cross-sectioned CNFs confirmed the uniform dispersion of NPs (ca. 18 nm diameter) inside the CNFs. Rietveld refinement analysis of X-ray diffraction patterns revealed that CNFs produced smaller Ag crystallites compared to CGT microparticles. The CNF-Ag hybrid was then fabricated into an aerogel using freeze-drying, with its weight being light enough to rest on a cotton flower's stamen. The infusion of Ag NPs led to approximately 20% reductions in the specific surface area and pore volume of the aerogel.

PEGylation of Mesoporous Silica Nanoparticles for Drug Delivery Applications

Mesoporous silica nanoparticles (MSNs) and PEGylated mesoporous silica nanoparticles (PEG-MSNs) were synthesized and characterized for potential targeted drug delivery applications. In this study, MSNs were synthesized via a sol-gel process to investigate in vitro drug release efficacy and subsequently PEGylated to impart colloidal stability and biocompatibility for future mouse model experiment. Comprehensive characterization techniques, including Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) analysis, and zeta potential measurements were employed. SEM analysis revealed uniformly distributed spherical nanoparticles with smooth surfaces, while FTIR confirmed the successful PEGylation in the surface of MSNs. BET analysis also indicated a reduction in surface area, pore volume, and pore size upon PEGylation, suggesting that PEG chains influence the nanoparticle structure. Zeta potential measurements showed a shift from negative to positive surface charge post-PEGylation, indicating improved colloidal stability. Drug loading and release studies utilizing doxorubicin hydrochloride (DOX) demonstrated a controlled release profile, with MSNs exhibiting a higher cumulative release compared to PEG-MSNs over 24 h. These findings underscore the potential of PEG-MSNs for controlled drug delivery, offering advantages such as reduced systemic toxicity and enhanced therapeutic efficacy for PEG-MSNs nanocarrier in the animal studies due to their increased colloidal stability.

Doxorubicin-loaded liposome-like particles embedded in chitosan/hyaluronic acid-based hydrogels as a controlled drug release model for local treatment of glioblastoma

Glioblastoma (GBM) resection and medication treatment are limited, and local drug therapies are required. This study aims to create a hybrid system comprising liposome-like particles (LLP-DOX) encapsulated in chitosan/hyaluronic acid/polyethyleneimine (CHI/HA/PEI) hydrogels, enabling controlled local delivery of doxorubicin (DOX) into the resection cavity for treating GBM. CHI/HA/PEI hydrogels were characterized morphologically, physically, chemically, mechanically, and thermally. Findings revealed a high network and compact micro-network structure, along with enhanced physical and thermal stability compared to CHI/HA hydrogels. Simultaneously, drug release from CHI/HA/PEI/LLP-DOX hydrogels was assessed, revealing continuous and controlled release up to the 148th hour, with no significant burst release. Cell studies showed that CHI/HA/PEI hydrogels are biocompatible with low genotoxicity. Additionally, LLP-DOX-loaded CHI/HA/PEI hydrogels significantly decreased cell viability and gene expression levels compared to LLP-DOX alone. It was also observed that the viability of GBM spheroids decreased over time when interacting with CHI/HA/PEI/LLP-DOX hydrogels, accompanied by a reduction in total surface area and an increase in apoptotic tendencies. In this study, we hypothesized that creating a hybrid drug delivery system by encapsulating DOX-loaded LLPs within a CHI/HA/PEI hydrogel matrix could achieve sustained drug release, improve anticancer efficacy via localized treatment, and effectively mitigate GBM progression for 3D microtissues.