Heterogeneous Surface Research Articles

Evolution of hepatitis B virus polymerase and surface genes in patients receiving finite antiviral therapy.

Hepatitis B virus (HBV) reactivation could develop after withdrawal following a finite course of nucleoside analog (NA) therapy, leading to virological and clinical relapses. The genetic heterogeneity in the HBV surface and polymerase genes during finite NA therapy has not been carefully studied. Seven chronic HBV-infected patients experiencing relapses following entecavir (ETV; n=5; Patients 1 to 5) or tenofovir disoproxil fumarate (TDF; n=2; Patients 6 and 7) withdrawal were included. Sera obtained before treatment and at relapses were retrieved and submitted for DNA extraction and amplicon-specific deep sequencing. ETV-treated patients had a longer time-to-relapse than that of TDF-treated patients (P=0.0357). No drug-resistance related polymerase mutation was detected during relapses, except for a low percentage (1.4%) of rtM204I mutation in Patient 1. Two surface truncation mutations (sW216*; 40.9% and sW182*; 4.7%) detected before treatment in two TDF-treated patients (Patients 6 and 7, respectively) were overtaken by the wild types during subsequent drug-withdrawal-related relapses. The simultaneous presence of sG44E (T-cell epitope) and sE164G (B-cell epitope) mutations was associated with failure of HBV e antigen (HBeAg) seroclearance in ETV-treated patients. In conclusion, HBV genome continues to evolve during the courses of finite antiviral therapies. Pre-existing surface truncation mutations can be overtaken by the wild types after relapses. The sG44E/sE164G mutations are associated with failure of HBeAg seroclearance.

Development of waterborne epoxy-based resin incorporated with modified natural rubber latex for coating application

Water-based coating has gained much attention globally due to environmental issues. This work aims to develop a waterborne epoxy coating incorporated with modified natural rubber (NR) latex for improved performance. For this purpose, the NR latex was modified into three types of low molecular weight epoxidized natural rubber (LENR) latex. The waterborne epoxy resin was prepared by simply mixing the epoxy resin with an amine curing agent in water and various LENR latex contents (10 to 50 wt%). The waterborne epoxy/LENR blend was coated on a tin substrate and the cured coating demonstrated better adhesion and bending properties than the neat epoxy. Phase morphological properties displayed a rough surface with a heterogeneous surface structure of the dispersed rubber and epoxy matrix. Two glass transition temperatures were observed, corresponding to the rubber modifier and the epoxy matrix. The mechanical properties of the thermosetting epoxy/LENR blends were assessed, revealing a maximum increment in elongation ability by approximately 370% for adding 50 wt% LENR, compared to the neat epoxy. These results hold the potential avenue for utilizing NR-based material in the waterborne epoxy-based resin for coating applications. Furthermore, it contributes to the NR, a renewable and eco-friendly material, in the coating technology, embracing a sustainable future.

The Effect of Single Walled Carbon Nanotubes on Conductivity and Thermal Properties of Glass Fiber Reinforced Composites

Abstract This paper reports on a comprehensive study of the effect of single-walled carbon nanotube (SWCNT) on the alternating current (AC) conductivity, thermal and morphological properties of the unsaturated polyester based glass fiber reinforced polymer composite (GFRPC). AC conductivity measurements were carried out using the impedance spectrum and thermal measurements were carried out using differential scanning calorimetry (DSC) at a temperature range of 24-900 °C and heating rates of 20 °C/min. Impedance results showed that the conductivity behavior in the nanotube-loaded composite laminate obeys a Jonscher-type mechanism. At low frequencies, the conductivity value remains almost constant for the doped material and takes the value of 10-5 S/cm. It is observed that the AC conductivity starts to increase after the critical frequency value of approximately 103 Hz and increases up to 10-2 S/cm due to hopping and tunneling mechanisms caused by space charge polarization accumulated in the local regions at high frequencies. The pure material with an insulating nature also exhibited a typical insulating behavior. Thermal testing showed that nanotube reinforcement increases thermal conductivity in three different directions. DSC thermocurves analysis also revealed that the addition of carbon nanotubes increased the glass transition temperature of the material from 180°C to 190°C. The scaling and fractal analysis methods were also applied to obtain hetero morphological structure of materials. The fractal analysis results indicated that carbon nanotube doping to the standard sample increases the coating rates, scalability and heterogeneity of the solid phase surface of the sample. The coating rates of composite surfaces were calculated as 45% and 36%, respectively. Morphology analysis revealed that the probability of finding surface particles for the nanotube-doped sample decreased compared to the undoped sample, but the fractal dimension value increased. While this value was 1.83 in the pure sample, it increased to 1.92 in the nanotube material.

Identification of the degree of aging and adsorption behaviors of the naturally aged microplastics

Microplastics (MPs) inevitably experienced various aging processes in nature may exhibit varied and complex interfacial interactions with adjacent species. Therefore, clarifying the possible interfacial interactions between naturally aged MPs and organic pollutants is of great significance to assess the actual behaviors of MPs in the environment. Here several plastic packaging materials after use were employed as the raw materials and representatives of naturally aged MPs, the alteration of surface characteristics, especially the degree of aging and the adsorption properties of MPs for anionic and cationic dyes were investigated. The types and the degree of aging of MPs were identified, and the variation of oxygen-containing functional groups (carbonyl, hydroxyl, and ester groups), the hydrophilicity and surface charge character were characterized. The fitting results of kinetics and isotherm models indicated that the adsorption was mainly multi-layer on heterogeneous surfaces, with hydrogen bonding, electrostatic attraction, polar interaction, and hydrophobic partitioning possibly involving. The hydrogen bond interaction was further confirmed by FTIR spectra. The increased temperature promoted the adsorption of cationic dyes on MPs, and the increased salinity of the solution enhanced the uptake of most of the tested dyes by MPs. This research deepened the understanding on the aging degree of MPs and their interfacial interactions with hydrophilic pollutants, and provided vital information for MPs as pollutant carriers.

Deep insight into the effect of smithsonite particle size on surface heterogeneity and adsorption behavior: A case of fatty acid system

The studies for microfine mineral flotation have focused on the two main directions of increasing the apparent mineral particle size and reducing the bubble size, while little research has been reported on the special surface properties and adsorption mechanisms of mineral particles of different sizes. In this study, sodium oleate was chosen as a typical surfactant. The mechanism of the effect of smithsonite particle size on the heterogeneity and adsorption behavior of the mineral surface was explored in depth. Through microflotation experiments, BET area tests, Washburn contact angle tests, particle agglomeration tests, adsorption tests and inorganic carbon analysis, it was pointed out that the smaller the size of the particles, the greater the surface wettability, and the smaller the density and thickness of adsorbed oleate on the surface. The difficulty of encapsulating the mineral surface with a hydrophobic layer of oleate hydrocarbon chains, as well as suboptimal particle aggregation sizes, are key reasons for the poor flotation behavior of fine smithsonite. Furthermore, the inhomogeneity of active sites and charge distribution of surface components of smithsonite with different sizes was revealed from a microscopic point of view by DRIFT spectroscopic analysis, XPS analysis and zeta potential measurements. As the particle size of smithsonite decreases, the positive charge density on the surface is higher and the hydration tendency is more intense, hindering the adsorption of oleate. This work is expected to guide the full particle size recovery of minerals in the flotation from a novel microscopic point of view.

Removal of phosphate from wastewater using zirconium/iron embedded chitosan/alginate hydrogel beads: An experimental and computational perspective

Adsorptive removal of phosphate plays a crucial role in mitigating eutrophication. Herein, the Zr/Fe embedded chitosan/alginate hydrogel bead (Zr/Fe/CS/Alg) is reported as an effective phosphate adsorbent. This polymer nanocomposite is synthesized by the in-situ reduction of the metals on the polymer matrix. The synthesized adsorbent was characterized by the FTIR, SEM-EDX, TGA, BET, and XPS. The adsorbent showed a maximum phosphate adsorption capacity of 221.72 mg/g at pH 3. The experimental data fit well with the Freundlich isotherm and pseudo-second-order kinetics model, indicating a heterogeneous multilayer surface formation and a chemisorption-dominated adsorption process. Density Functional Theory (DFT) and Monte Carlo (MC) calculations revealed high negative adsorption energy due to the chemisorption of phosphate on the adsorbent. Hence, the major interactions such as electrostatic attraction, hydrogen bonding, and inner-sphere complexation of phosphate adsorption and Zr/Fe/CS/Alg hydrogel beads were investigated from the experimental and computational analysis. The negative values of thermodynamic parameters indicated a spontaneous, exothermic, and less random adsorption process. The synthesized adsorbent exhibited excellent selectivity toward phosphate and maintained 73 % efficiency after six adsorption/desorption cycles. The Zr/Fe/CS/Alg hydrogel beads reduced the phosphate concentration in real wastewater samples from 19.02 mg/L to 0.985 mg/L, suggesting that these nanocomposite hydrogel beads could be a promising adsorbent for real-world applications.

Improvements in the land surface configuration to better simulate seasonal snow cover in the European Alps with the CNRM-AROME (cycle 46) convection-permitting regional climate model

Abstract. Snow cover modeling remains a major challenge in climate and numerical weather prediction (NWP) models even in recent versions of high-resolution coupled surface–atmosphere (i.e., at kilometer scale) regional models. Evaluation of recent climate simulations, carried out as part of the WCRP-CORDEX Flagship Pilot Study on Convection (FPSCONV) with the CNRM-AROME convection-permitting regional climate model at 2.5 km horizontal resolution, has highlighted significant snow cover biases, severely limiting its potential in mountain regions. These biases, which are also found in AROME numerical weather prediction (NWP) model results, have multiple causes, involving atmospheric processes and their influence on input data to the land surface models in addition to deficiencies of the land surface model itself. Here we present improved configurations of the SURFEX-ISBA land surface model used in CNRM-AROME. We thoroughly evaluated these configurations on their ability to represent seasonal snow cover across the European Alps. Our evaluation was based on coupled simulations spanning the winters of 2018–2019 and 2019–2020, which were compared against remote sensing data and in situ observations. More specifically, the study tests the influence of various changes in the land surface configuration, such as the use of multi-layer soil and snow schemes, the division of the energy balance calculation by surface type within a grid cell (multiple patches), and new physiographic databases and parameter adjustments. Our findings indicate that using only more detailed individual components in the surface model did not improve the representation of snow cover due to limitations in the approach used to account for partial snow cover within a grid cell. These limitations are addressed in further configurations that highlight the importance, even at kilometer resolution, of taking into account the main subgrid surface heterogeneities and improving representations of interactions between fractional snow cover and vegetation. Ultimately, we introduce a land surface configuration, which substantially improves the representation of seasonal snow cover in the European Alps in coupled CNRM-AROME simulations. This holds promising potential for the use of such model configurations in climate simulations and numerical weather prediction both for AROME and other high-resolution climate models.

Waste refractory brick material added chitosan/oxidized pullulan complex gel production and removal of heavy metals from waste water

Wastewater is a by-product of numerous industrial processes that have been demonstrated to have adverse effects on human and natural health due to the pollutants it contains. The pollutants in these substances are organic or inorganic molecules and heavy metal ions that significantly harm the environment and human health. A variety of techniques have been devised for the removal of heavy metal ions from wastewater. The adsorption process has attracted significant attention due to its straightforward implementation, cost-effectiveness, and the environmentally friendly production of adsorbent materials using biocompatible substances. In this study, the removal of Cu2+ ions from wastewater was conducted using chitosan pullulan, a biocompatible and biodegradable polymer. In addition to chitosan and pullulan, waste refractory materials from a furnace used in iron and steel production were added to these polymer materials to increase the adsorption capacity. The initial step involved grinding the waste refractory brick material. Subsequently, chitosan was dissolved in acetic acid. After that, the refractory material was suspended in this solution, facilitating the formation of hydrogel beads using a NaOH solution. The obtained hydrogels were coated with pullulan to produce polyelectrolyte gel. Pullulan was oxidized to 6-carboxypullulan by the TEMPO (2,2,6,6-Tetramethylpiperidin-1-yl)oxyl) oxidation method and the negatively charged groups in its structure interacted with the positively charged groups in the chitosan structure to produce a complex gel. The chemical structure, morphological analysis, thermal analysis, and water release analysis of the produced waste refractory brick material added chitosan/oxidized pullulan complex gels were examined. The impact of the 6-carboxypullulan coating on the gels’ properties was elucidated. Furthermore, the adsorption of Cu2⁺ was conducted using solutions containing 100, 500, and 1000 ppm Cu2⁺ ions. It has been observed that the material can clean water with over 98% efficiency, even in solutions that exceed the standards set for wastewater. The material’s efficacy in cleaning solutions with concentrations above the standard for wastewater cleaning is evidence of its high performance. Furthermore, the kinetics and isotherm of the adsorption reaction were examined. The kinetics were determined to be consistent with the Pseudo Second Order (chemical reaction controlled) and aligned with the Langmuir and Freundlich Isotherm (mixed adsorption occurred on homogeneous and heterogeneous surfaces).

Evaluation of Surface Reflectance and Vegetation Indices Measured by Sentinel-2 Satellite Using Drone Considering Crop Type and Surface Heterogeneity

Evaluation of Surface Reflectance and Vegetation Indices Measured by Sentinel-2 Satellite Using Drone Considering Crop Type and Surface Heterogeneity

Adsorption Thermodynamics for Process Simulation.

Adsorption has rapidly evolved in recent decades and is an established separation technology extensively practiced in gas separation industries and others. However, rigorous thermodynamic modeling of multicomponent adsorption equilibrium remains elusive, and industrial practitioners rely heavily on expensive and time-consuming trial-and-error pilot studies to develop adsorption units. This article highlights the need for rigorous adsorption thermodynamic models and the limitations and deficiencies of existing models such as the extended Langmuir isotherm, dual-process Langmuir isotherm, and adsorbed solution theory. It further presents a series of recent advances in the generalization of the classical Langmuir isotherm of single-component adsorption by deriving an activity coefficient model to account for the adsorbed phase adsorbate-adsorbent interactions, substituting adsorbed phase adsorbate and vacant site concentrations with activities, and extending to multicomponent competitive adsorption equilibrium, both monolayer and multilayer. Requiring a minimum set of physically meaningful model parameters, the generalized Langmuir isotherm for monolayer adsorption and the generalized Brunauer-Emmett-Teller isotherm for multilayer adsorption address various thermodynamic modeling challenges including adsorbent surface heterogeneity, isosteric enthalpies of adsorption, BET surface areas, adsorbed phase nonideality, adsorption azeotrope formation, and multilayer adsorption. Also discussed is the importance of quality adsorption data that cover sufficient temperature, pressure, and composition ranges for reliable determination of the model parameters to support adsorption process simulation, design, and optimization.

Observed response of microwave land surface emissivity to antecedent rainfall in Hainan Island

ABSTRACT Microwave emissivity is an important parameter for over-land retrieval of atmospheric variables such as water vapour, rainfall, and snowfall. However, it remains unclear for the dynamic response of multi-frequency microwave emissivity to prior rainfall over heterogeneous land surfaces. This study combined multi-frequency Microwave Land Surface Emissivity (MLSE) under all-weather conditions with hourly in-situ rainfall to investigate the response of MLSE to rainfall over different vegetation types in Hainan Island in China. Specifically, we explored the change of MLSE at 6.925, 10.65, 18.7, 23.8 and 36.5 Ghz to rainfall intensity in four rainfall cases, followed with statistical characteristics of MLSE to rainfall and dry duration (DD) across different vegetation types during 2003–2010. We found that the magnitude of decline in MLSE (0.004–0.06) is dependent on the rainfall intensity and duration, and the reduction caused by short-lasting heavy rain (daily rainfall >100 mm) was 2–6 times higher than that by light long-lasting rain (daily rainfall <80 mm). Among different microwave frequencies, the MLSE at 23.8 Ghz was most reduced by rainfall, while less reduction was found at low microwave frequencies such as at 6.925 and 10.65 Ghz. More importantly, the change of MLSE after rainfall was significantly different among vegetation types. Over woody savannas and forested lands, MLSE slightly decreased (about 0.004) in the first two hours of DD, whereas a rapid increase was observed in the first hour of DD over areas dominated with woody savanna, grassland, and cropland. These findings improve our understanding of the multi-frequency MLSE in response to rainfall over complex land surfaces, and benefit the microwave retrieval of rainfall over land.

CO2 capture enhancement by metal oxides impregnated coal fly ash: a breakthrough adsorption study.

Coal fired power plants are significant contributors to CO2 emissions and produce solid waste in the form of coal fly ash, posing severe environmental challenges. This study explores the application of dry-impregnated coal fly ash for CO2 capture from gas stream. The modification of coal fly ash was achieved using alkaline earth metal oxides, specifically CaO and MgO, to alter its physical and chemical properties. Characterization techniques like X-ray fluorescence (XRF), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and BET (Brunauer-Emmett-Teller) analysis were employed for physio-chemical changes in the adsorbent. Breakthrough experiments were conducted using a laboratory-scale fixed packed-bed reactor to assess the influence of temperature and gas flow rate on CO2 adsorption. Among the synthesized sorbents, calcium oxide-impregnated ash showed the highest CO2 uptake capacity, achieving 9.41mg/g at 30°C and a flow rate of 20 L/hr under atmospheric pressure. Isotherm modeling indicated a heterogeneous adsorbent surface, with the data best fitting the Sips isotherm model. Furthermore, the adsorption data conformed well to the Yoon-Nelson and Thomas kinetic models, affirming their relevance in characterizing the adsorption process under varying conditions. This research emphasizes the potential of coal fly ash-an abundant, cost-free material-as an effective CO2 adsorbent, contributing to both CO2 mitigation and landfill waste reduction.

Evolution of Graded Surface Microstructure and Property of Ti6Al4V Threads Processed by Surface Rolling

The surface rolling process is important for the forming property of titanium alloy bolts. This study systematically investigated the evolution of the surface microstructure and property of Ti6Al4V threads induced by surface rolling processes with different feeding times. Gradient surface microstructure and property, as characterized by the depth-dependent variations of refined and deformed grains and hardness, were revealed. A comparative analysis of the microstructure and property of the topmost and subsurface layers in different characteristic areas (root, flank, and crest) of the thread was specifically carried out. The surface microstructure and properties are highly heterogeneous in different areas of the rolled thread. Meanwhile, a gradient microstructure and hardness along the depth from the surface was revealed in the surface layer. Our results showed that the highly heterogeneous surface microstructure and property can be attributed to the close correlation between the different stress/strain levels at different depths from the surface and the different deformation mechanisms in the characteristic surface areas of the thread. The present study has indicated that the distinctive microstructure and property in the different characteristic areas of the rolled thread should be featured by those of surface layers at different depths.

Sensitivity and Uncertainty Analysis of the GeeSEBAL Model Using High-Resolution Remote-Sensing Data and Global Flux Site Data

Actual evapotranspiration (ETa) is an important component of the surface water cycle. The geeSEBAL model is increasingly being used to estimate ETa using high-resolution remote-sensing data (Landsat 4/5/7/8). However, due to surface heterogeneity, there is significant uncertainty. By optimizing the quantile values of the reverse-modelling automatic calibration algorithm (CIMEC) endpoint-component selection algorithm under extreme conditions through 212 global flux sites, we obtained the optimized quantile values of 11 vegetation types of cold- and hot-pixel endpoint components (Ts and NDVI). Based on the observation data of the global FLUXNET tower, the sensitivity of 20 parameters in the improved geeSEBAL model was determined through Sobol’s sensitivity analysis. Among them, the parameters dT and SAVI,hot were confirmed as the most sensitive parameters of the algorithm. Subsequently, we used the differential evolution Markov chain (DE-MC) method to analyse the uncertainty of the parameters in the geeSEBAL model used the posterior distribution of the parameters to modify the sensitive parameter values or ranges in the improved geeSEBAL model and to simulate the daily ETa. The results indicate that by analysing the end element components of the geeSEBAL model (Ts and NDVI), quantile numerical optimization and parameter optimization can be performed. Compared with the original algorithm, the improved geeSEBAL model has significantly improved simulation performance, as shown by higher R2 values, higher NSE values, smaller bias values, and lower RMSE values. The most suitable values of the predefined parameter Zoh were determined, and the reanalysis of meteorological data inputs (relative humidity (RH), temperature (T), wind speed (WS), and net radiation (Rn)) was also found to be an important source of uncertainty for the accurate estimation of ETa. This study indicates that optimizing the quantiles and key parameters of the model end component has certain potential for further improving the accuracy of the geeSEBAL model based on high-resolution remote-sensing data in estimating the ETa for various vegetation types.

ASPECTS OF SURFACE ENAMEL MINERALIZATION IN PERMANENT TEETH OF CHILDREN FROM DIFFERENT AGE GROUPS

The purpose of our study was the examination of external surface enamel mineralization in permanent teeth of children from different age groups. We examined sections of 50 extracted for orthodontic indications premolars in patients from different age groups. A study of 16 teeth was conducted in 11-13 years old children, 8 teeth were investigated in each group of 13-15 years old, as well as 9 teeth in 15-16-year-old patients. All patients were appointed with remineralization therapy during the first six months after tooth eruption fallowed by application of “Tooth Mousse” ones a day for 2 weeks every six months with appropriate monitoring. The comparison group, on the other hand, consisted from extracted teeth taken from children who were not subjected to any preventive remineralization measures. The distribution by age and the studied material was identical to the main group. Segmentation of the teeth was carried out after the tooth extraction with separation of the crown structure and further polishing of the crown using polishing brushes without pastes. Sections 0.3-0.5 mm thick were formed with a diamond disc. The enamel samples were cleaned and degreased and then examined in a polarizing microscope (Optika B-150POL-B 40x-640x Bino) at a magnification in 500 times. The description of the enamel microscopic surface was carried out according to the following parameters: surface heterogeneity, surface opaqueness/shininess, surface roughness/smoothness. The surface homogeneity was assessed by calculating the ratio of identified surface areas that visually differed from the overall enamel texture, which was characteristic of the predominant investigated surface enamel. There were criteria for evaluating the enamel surface heterogeneity according to the research data in a polarizing microscope : the presence of numerous well-defined cracks, the visualization and number of areas from which the enamel prisms extend, the presence and number of enamel surface irregularities confirmed by a change in the direction of the light beam, the percentage of surface homogeneity, which was calculated as the ratio of the area of ​​the visually homogeneous enamel surface to the area with ​​any microscopically detected changes. To assess the opacity of the enamel surface by the microscopic polarization study, the criteria of visual assessment of shiny and dark areas of interest were used. The study suggested that microscopic changes are characterized by a decrease of total number in enamel surface irregularities and an increase of its glossiness and smoothness at the approach of structural compositional stabilization at 15-16 years. The analysis also revealed that there were marked microscopic differences observed in enamel of 15-16 years old after remineralization with the "Tooth Mousse" gel and a comparison group (without remineralization therapy).The difference between them is reliable (p&lt;0.01) according to the indicators of the relative average level of surface heterogeneity, and also statistically different from similar indicators that were registered in the age groups 11-13 and 13-15 years old (p&lt;0.01). The gained results can be considered as the expediency grounds for implementation of dental caries prevention at the early stages of secondary mineralization (immediately after eruption) and throughout the entire period of its intensive phase, which will further contribute to the stabilization of the caries-resistant enamel.

Mediastinal Teratoma with Angiosarcomatous Overgrowth in a Background of Vasculogenic Mesenchymal Tumor

Abstract Introduction/Objective Vasculogenic mesenchymal tumor refers to neoplastic reiteration of embryonic vasculogenesis. It is most commonly associated with nonseminomatous germ cell tumors of the mediastinum, in particular yolk sac tumor. In rare instances these lesions progress to angiosarcoma. Herein, we describe a case of angiosarcoma in a background of vasculogenic mesenchymal tumor in the setting of a mediastinal teratoma. Methods/Case Report A 33-year-old male, with a past medical history of anxiety, and right orchiectomy for testicular torsion, presented with shortness of breath, chest pain, and left arm swelling. Imaging studies demonstrated a mediastinal mass. Biopsy of the mass showed a germ cell tumor most compatible with a teratoma in the limited specimen. The patient received two rounds of chemotherapy and additional treatments were discontinued due to poor tolerance. Subsequent imaging showed continued increase in the size along with mass effect causing moderate to severe compression of the superior vena cava. Subsequently, the patient underwent resection of the mass. Grossly the mass was predominantly encapsulated with areas of capsular disruption. Sectioning revealed heterogeneous cut surfaces with fleshy, cystic, and necrotic areas. Morphologically the tumor was composed predominantly of teratomatous elements with areas of anastomosing atypical vascular channels within a hypocellular stroma suggestive of vascular genic mesenchymal as well as areas reminiscent of Masson lesion. Focally within these areas were malignant spindle cell proliferations compatible with angiosarcoma. The patient had an elevated AFP; however, no yolk sac tumor component was identified after thorough sampling. Final diagnosis of teratoma with angiosarcoma in a background of vasculogenic mesenchymal tumor was rendered after expert consultation. Results (if a Case Study enter NA) NA Conclusion Somatic-type malignancy and sarcomatous overgrowth are known to occur in mediastinal germ cell tumors; however, classification of the sarcomatous overgrowth can be challenging. Vasculogenic mesenchymal tumor is an exceedingly rare sarcomatous overgrowth that can rarely progress to angiosarcoma.

Reversible Photochromic Reactions of Bacteriorhodopsin from Halobacterium salinarum at Femto- and Picosecond Times

The operation of bacteriorhodopsin (BR) from the archaeon Halobacterium salinarum is based on the photochromic reaction of isomerization of the chromophore group (the retinal protonated Schiff base, RPSB) from the all-trans to the 13-cis form. The ultrafast dynamics of the reverse 13-cis → all-trans photoreaction was studied using femtosecond transient absorption spectroscopy in comparison with the forward photoreaction. The forward photoreaction was initiated by photoexcitation of BR by pulse I (540 nm). The reverse photoreaction was initiated by photoexcitation of the product K590 at an early stage of its formation (5 ps) by pulse II (660 nm). The conversion of the excited K590 to the ground state proceeds at times of 0.19, 1.1, and 16 ps with the relative contributions of ~20/60/20, respectively. All these decay channels lead to the formation of the initial state of BR as a product with a quantum yield of ~1. This state is preceded by vibrationally excited intermediates, the relaxation of which occurs in the 16 ps time range. Likely, the heterogeneity of the excited state of K590 is determined by the heterogeneity of its chromophore center. The forward photoreaction includes two components—0.52 and 3.5 ps, with the relative contributions of 91/9, respectively. The reverse photoreaction initiated from K590 proceeds more efficiently in the conical intersection (CI) region but on the whole at a lower rate compared to the forward photoreaction, due to significant heterogeneity of the potential energy surface.

Electrochemical Selective Removal of Oxyanions in a Ferrocene-Doped Metal-Organic Framework.

Metal-organic frameworks (MOF) are a class of crystalline, porous materials possessing well-defined channels that have widespread applications across the sustainable landscape. Analogous to zeolites, these materials are well-suited for adsorption processes targeting environmental contaminants. Herein, a zirconium MOF, UiO-66, was functionalized with ferrocene for the selective removal of oxyanion contaminants, specifically NO3-, SO42-, and PO43-. Electrochemical oxidation of the embedded ferrocene pendants induces preferential adsorption of these oxyanions, even in the presence of Cl- in a 10-fold excess. Anion selectivity strongly favoring PO43- (Soxy/comp = 3.80) was observed following an adsorption trend of PO43- > SO42- > NO3- > (10-fold)Cl- in multi-ion solution mixtures. The underlying mechanisms responsible for ion selectivity were elucidated by performing ex situ X-ray photoelectron spectroscopy (XPS) on the heterogeneous electrode surface postadsorption and by calculating the electronic structure of various adsorption configurations. It was eventually shown that oxyanion selectivity stemmed from strong ion association with a positively charged pore interior due to the spatial distribution of charge by oxygen constituents. While ferrocenium provided the impetus for ion migration-diffusion, it was the formation of stable complexes with zirconium nodes that ultimately contributed to selective adsorption of oxyanions.

Coalescence and Rebound Dynamics in Two Droplets Train Impacting on a Heterogeneous Wettability Surface.

Droplets that can be steered and rebound off surfaces are fundamentally interesting and important due to their promising potential in numerous applications, such as anti-icing and -fogging, spray coating, and self-cleaning. Heterogeneous wettability surfaces have been shown to be an effective means of droplet manipulation. This paper combines numerical simulation with theoretical analysis to investigate the dynamics of two droplets training impacting on and bouncing off a heterogeneous surface (superhydrophobic substrate decorated with a hydrophilic strip). First, the time evolutions of the droplet morphology and velocity vectors are examined to explore the particular dynamic behaviors. At different ratios of the impact velocity, three distinct rebound patterns are observed, and a regime diagram is established. After that, the effects of the impact conditions and surface wettability on the rebound performance of the coalesced droplet are studied systematically. Special attention is paid to the variations of the rebound height and the lateral transportation distance with the Weber number of two droplets and the distance between the impacting point and the hydrophilic stripe. Moreover, a theoretical analysis of two droplets' impact is performed based on the energy conservation. The obtained scaling laws match well with the numerical data in the trend. Our research may strengthen the understanding of the interactions between droplets, which is valuable for the manipulation of multiple droplets in related fields.

Development of Pericarp-Based Coatings from Corn Nixtamalization Residue for Stone Fruits: Applications for Peach and Tejocote

This study investigated corn pericarp, a by-product of the nixtamalization process, in developing sustainable films for fruit coatings. These films were evaluated for their optical, structural, barrier, and mechanical properties. The results showed that the pericarp films were transparent, had heterogeneous surfaces, and exhibited favorable mechanical and barrier properties, suggesting their potential as fruit coatings. The pericarp films significantly extended shelf life when applied to peaches and tejocotes postharvest. The films slowed the maturation process, as evidenced by minimal changes in peel and mesocarp color for up to five days for tejocotes and even longer for peaches. Additionally, coated fruits showed slower rates of weight loss, firmness reduction, and decreases in titratable acidity, total soluble solids, and total sugar content compared to control samples. These findings demonstrate the potential of corn pericarp films as effective coatings for extending the shelf life of stone fruits.