Reduction In Total Surface Area Research Articles

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.

Autologous Cranioplasty Using a Dental SafeScraper Device.

Conventional methods to reconstruct cortical bone defects introduced by pediatric cranial vault remodeling (CVR) procedures have shortcomings. Use of bone burr shavings as graft material leads to variable ossification, and harvesting split-thickness cortical grafts is time-intensive and often not possible in thin infant calvaria. Since 2013, the authors' team has used the SafeScraper, originally developed as a dental instrument, to harvest cortical and cancellous bone grafts during CVR. The authors assessed the effectiveness of this technique by analyzing postoperative ossification using computed tomography scans of 52 patients, comparing cohorts treated with the SafeScraper versus those who received conventional methods of cranioplasty during fronto-orbital advancement. The SafeScraper cohort had a greater reduction in total surface area of all defects (-83.1% ± 14.9 versus -68.9% ± 29.8; P = 0.034), demonstrating a greater and more consistent degree of cranial defect ossification compared with conventional methods of cranioplasty, suggesting potential adaptability of this tool. This is the first study that describes the technique and efficacy of the SafeScraper in reducing cranial defects in CVR. Therapeutic, III.

Autologous Platelet Rich Plasma Promotes the Healing of Non-Ischemic Diabetic Foot Ulcers. A Randomized Controlled Trial

DFU (diabetic foot ulcer) represents a major global health and socioeconomic problem and a leading cause of lower limb amputation. Although many therapies have been tested, none has been proposed as a dominant wound healing treatment. We performed a prospective randomized controlled study in order to assess the role of autologous platelet rich plasma (PRP) for the promotion of non-ischemic DFU healing. After full vascular assessment, a total of 80 patients were randomized in 1:1 ratio to receive either PRP injection in the healing edge and the floor of the targeted DFU (Group A), or have usual standard care with moist dressing with or without collagenase ointment (Group B). We calculated the total surface area (TSA) for the ulcer in both groups (cm2) before, after treatment and every week up to 12 weeks of follow-up. A total of 4 patients (10%) experienced major amputation in group B, while no major amputation was performed in patients of Group A (P< 0.001). A ≥ 50% reduction in TSA occurred earlier in Group A (at 2.5 weeks), compared to Group B (4.5 weeks); P < 0.001. Complete wound healing rate was 95% (n=38) and it was achieved earlier (6th week) for patients of group A, contrary to 77.8% (n=28) of patients (9th week) for Group B (P < 0.001). Superficial wound infection was noted in 10% (n=4) of the cases in the PRP arm, while in group B, 45% (n=18) of cases had a variable degree of infection ranging from superficial to deep wound infection and cellulites (P < 0.001). PRP treatment was cost-effective, with 247.50$ vs. 437.50$ for the total cost of treatment for patients of Group B. PRP is a cost-beneficial novel modality of treatment that can accelerate wound healing and decrease the rate of local infection in DFU, compared to other conventional treatment modalities.

Persistence in soil of microplastic films from ultra-thin compostable plastic bags and implications on soil Aspergillus flavus population

An increasing number of states and municipalities are choosing to reduce plastic litter by replacing plastic items, particularly single-use ones, with same-use products manufactured from compostable plastics. This study investigated the formation and persistence of compostable film microplastic particles (CFMPs) from ultra-thin compostable carrier bags in soil under laboratory conditions, and the potential impact of CFMPs on Aspergillus flavus populations in the soil.During a 12-month incubation period, compostable film samples in soils with small, medium or large populations of indigenous A. flavus, underwent 5.9, 9.8, and 17.1% reduction in total surface area, respectively. Despite the low levels of deterioration, the number of CFMPs released increased steadily over the incubation period, particularly fragments with size < 0.05 mm. Up to 88.4% of the released fragments had associated A. flavus and up to 68% of isolates from CFMPs produced aflatoxins. A. flavus levels associated with CFMPs increased rapidly during the initial part of the 12-month incubation period, whereas the percent aflatoxigenicity continued to increase even after A. flavus density leveled off later. During 12 months incubation, A. flavus DNA amounts recovered from CFMPs increased in soils with all levels of indigenous A. flavus, with the largest increases (119.1%) occurring in soil containing the lowest indigenous A. flavus. These results suggest that burying compostable film in soil, or application of compost containing CFMPs, may reduce soil quality and increase risk of adverse impacts from elevated aflatoxigenic A. flavus populations in soil.

Tailoring the Properties of Metal Oxide Loaded/KCC-1 toward a Different Mechanism of CO2 Methanation by in Situ IR and ESR.

Nickel (Ni), cobalt (Co), and zinc (Zn) loaded on fibrous silica KCC-1 was investigated for CO2 methanation reactions. Ni/KCC-1 exhibits the highest catalyst performance with a CH4 formation rate of 33.02 × 10-2 molCH4 molmetal-1 s-1, 1.77 times higher than that of Co/KCC-1 followed by Zn/KCC-1 and finally the parent KCC-1. A pyrrole adsorption FTIR study reveals shifting of perturbed N-H stretching decreasing slightly with the addition of metal oxide, suggesting that the basic sites of catalyst were inaccessible due to metal oxide deposition. The strengths of basicity were found to follow sthe equence KCC-1, Ni/KCC-1, Zn/KCC-1, and Co/KCC-1. The data were supported by N2 adsorption desorption analysis, where Co/KCC-1 displayed the greatest reduction in total surface area whereas Ni/KCC-1 displayed the least reduction. The elucidation of difference mechanism pathways has also been studied by in situ IR spectroscopy studies to determine the role of different metal oxides in CO2 methanation. It was discovered that Ni/KCC-1 and Co/KCC-1 follow a dissociative mechanism of CO2 methanation in which the CO2 molecule was dissociated on the surface of the metal oxide before migration onto the catalyst surface. This was confirmed by the evolution of a peak corresponding to carbonyl species (COads) on a metal oxide surface in FTIR spectra. Zn/KCC-1, on the other hand, showed no such peak, indicating associative methanation pathways where a hydrogen molecule interacts with an O atom in CO2 to form COads and OH. These results offers a better understanding for catalytic studies, particularly in the field of CO2 recycling.

Gel structure phase behavior in micro nanofibrillated cellulose containing in situ precipitated calcium carbonate

ABSTRACTSpeciality high‐strength board, packaging grades, and novel cellulose‐based nanocomposites may incorporate microcellulosic nanofibrillated materials (MNFC), although the rheological properties of such strongly water sorbing structures are challenging for processing technologies. This study introduces rheological methods for the evaluation of dewatering and flow behavior of such high consistency furnishes to exemplify the effect of energy input on microfibrillar material (MFC), as produced by a combination of enzymatic pretreatment and increased levels of fluidization. The large number of fibril contact points act to entrap water, held both on the fibril surface as immobilized water and in the interfibril spacing forming the gel structure. Tuning of the rheological and dewatering properties has been enabled by in situ precipitation of calcium carbonate filler (in situ PCC) on the MFC, which results in the production of a more uniform furnish. Such in situ PCC coated MFC fibrils incorporated into furnish were seen to increase dewatering rate over that of the furnish mix without the in situ precipitated filler primarily because of the reduction in total surface area of the fibers and fibrils when the pigment is present on the fibrillary surface. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43486.

Effects of Oxygen Plasma and Dopamine Coating on Poly(Vinylidene Fluoride) Microfiltration Membrane for the Resistance to Protein Fouling

Poly(vinylidene fluoride) (PVDF) membrane was widely employed for filtration owing to its good mechanical property, thermal stability, and solvent resistance. However, the hydrophobic surface of PVDF might result in protein adsorption and the reduction of permeate flux. This paper proposed two approaches, O 2 plasma treatment and dopamine coating, to study the protein fouling behavior on PVDF membranes. Both O 2 plasma modified and dopamine coated PVDF membranes showed reduced water contact angles. Moreover, O 2 plasma resulted in higher surface area and higher surface electronegativity, while dopamine coating caused the reduction of total surface area of membrane and imparted positive charges. electron spectroscopy for chemical analysis characterizations confirmed the presence of oxygen functionalities that validated the functionalities accounted for the negative charges. The fouling resistance to bovine serum albumin (BSA) was promoted by O 2 plasma treatment, where the time to reach fouling was delayed by more than 10 min and the flux was higher on the modified PVDF than that on the pristine membrane. Further reduction of membrane fouling was achieved by prolonging the plasma treatment time, which resulted in more negatively charged PVDF surface. On the other hand, rapid flux reduction was observed on the dopamine coated PVDF membrane, whereas the resistance to protein was limited. The results of dynamic BSA adsorption indicated that the membrane fouling was affected by the overall resulted surface properties including surface electrical charge, surface wettability, and surface area. Moreover, oxygen plasma treatment proved to promote the filtration performance effectively, which is presumably due to the surface charge effects. On the other hand, the adhesive dopamine coating resulted in stronger protein adhesion and therefore fast flux loss. The obtained results provide alternative surface modification methods for microfiltration membranes with higher efficiency and better fouling resistance.

Effect of lean/rich high temperature aging on NO oxidation and NOx storage/release of a fully formulated lean NOx trap

Commercial-intent lean NOx traps (LNTs) containing Pt, Pd, Rh, Ba, Ce, Zr, and other proprietary additives were thermally aged at 750, 880, 930, and 1070°C using lean/rich cycling and then investigated for effects of aging on NOx storage capacity, NO oxidation, NOx reduction, and materials properties. Additionally, DRIFTS analysis was used to determine the effects of high temperature aging on surface chemistry and NOx storage. As platinum group metal (PGM) dispersion decreases with aging, the NO turnover frequency (TOF) for NO oxidation at 200, 300, and 400°C is shown to increase. The fraction of stored NOx that is successfully reduced also increases with aging, and it is suggested that this is accounted for by a slower release of more stable NOx species resulting from thermal aging. NOx storage and NOx release experiments performed with DRIFTS at 200, 300, and 400°C indicate that a substantial amount of NOx is stored on Al2O3 as nitrates at 200 and 300°C before aging. However, almost no nitrates are seen on alumina after aging at 900 and 1000°C, resulting in a significant reduction in NOx storage capacity. This is most likely due to a 45% reduction in total surface area and a high temperature redispersion of Ba over remaining alumina sites. No evidence of BaAl2O4 was observed with XRD.

Reduction in total surface area by the develpment of microdroplets during dewetting

To meet the demand of an increasing storage density, the lubricant film for the head disk interface (HDI) needs to be thinner and stronger. In recent years, a new head/disk system, such as the contact type, has been proposed. It is reported that PFPE Zdol coated on a magnetic disk is dewetted and microdroplets are formed due to polar interactions. This makes a flying magnetic head unstable, therefore, the physics and chemistry of the dewetting phenomenon are topics of current interest. We investigated the formation and development of microdroplets using an atomic force microscope (AFM) and an optical microscope. First, we observed the disk surface coated with PFPE Zdol by AFM. From the cross section images of the microdroplets, we found that the microdroplets had a shape similar to a sphere. With this finding, we estimated the contact angle of the microdroplets in each image. The results showed that the contact angle of the microdroplet gradually decreased with time, which indicated the existence of a PFPE thin film in the dewetted area. The thickness of the PFPE film in the dewetted area was then measured using an elliposometer. Next, we investigated the variation in the number and the average diameter of the microdroplets during dewetting using images observed by the optical microscope. The total surface area change was also calculated from the observed results, and it was found that the total surface area, namely the sum of the microdroplet surfaces and dewetted area, was reduced by the development of the microdroplets.

Pedogenic Formation of High-Charge Beidellite in a Vertisol of Sardinia (Italy)

AbstractThe fine clay (&lt;0.1 μm) fraction of a clayey soil (Vertisol) from Sardinia (Italy) was studied by means of X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, cation exchange capacity (CEC) and surface area measurements. Smectites were the dominant clay minerals both in the parent material and the soil horizons. The magnitude and location of the smectites’ layer-charges were analyzed using the Hofmann &amp; Kiemen effect (suppression of the octahedral charge following lithium-saturation and heating). The amount of montmorillonite layers was evaluated by measuring the reduction of total surface area and CEC after suppression of octahedral charges and subsequent collapse of montmorillonite interlayers. Reduction of total surface area and CEC after fixation of K and irreversible collapse of interlayers were used to quantify high-charge layers before and after the suppression of octahedral charges. This allowed us to evaluate the amount of tetrahedral high-charge layers. The smectites in the parent material were montmorillonitic-beidellitic mixed layers and exhibited a small proportion of high-charge layers; in particular, layers with a high tetrahedral charge were a very minor component. In the upper soil horizons, the amount of montmorillonitic layers decreased whereas the amount of smectite layers with a high tetrahedral charge increased. FTIR spectroscopy indicated more Fe for Al substitution in the smectites of the soil horizons than in the smectites of the parent material. The results suggested that octahedral charged smectite layers (montmorillonitic) were altered, whereas high-charge beidellitic layers were formed in this soil environment characterized by rather high pH (&gt;8.0).

Influence of aluminium and potassium on activity and texture of fused iron Catalysts for ammonia synthesis

BET, scanning electron microscopy and X-ray diffraction were used to investigate the texture of fused iron Catalysts which had been previously reduced and passivated, and into which potassium hydroxide was introduced by impregnation or aluminium removed by extraction. Activity tests were carried out under 10.0 MPa in the 400–520 °C temperature range. Investigations were performed on the doubly promoted (Al, Ca) and industrial, triply promoted (K, Al, Ca) Catalysts. Introduction of potassium hydroxide into the doubly promoted Catalyst increases the process rate by about 15–20 times per unit surface area. Sintering and recrystallization are observed in the Catalyst, proving that interaction takes place during the process between the potassium hydroxide introduced and the alumina present on the iron surface. Partial removal of aluminium from the surface of the doubly and triply promoted Catalysts also leads to sintering and recrystallization under ammonia synthesis conditions. This shows that the presence of alumina on the surface, and not within the iron, is responsible for textural promotion. Loss of Catalysts activity is proportional to reduction in total surface area.