Three commercial resins bearing sulfonic, amino phosphonic, or phosphonic/sulfonic reactive groups have been tested for the removal of iron and cadmium from phosphoric acid solutions. The sorption ...properties are compared for different experimental conditions such as sorbent dosage (0.5–2.5 g L
−1
), phosphoric acid concentration (from bi-component solutions, 0.25–2 M), and metal concentrations (i.e., in the range 0.27–2.7 mmol Cd L
−
1
and 0.54 mmol Fe L
−1
) with a special attention paid to the impact of the type of reactive groups held on the resins. The sulfonic-based resin (MTC1600H) is more selective for Cd (against Fe), especially at high phosphoric acid concentration and low sorbent dosage, while MTS9500 (aminophosphonic resin) is more selective for Fe removal (regardless of acid concentration and sorbent dosage). Equilibrium is reached within 2–4 h. The resins can be ranked in terms of cumulative sorption capacities according the series: MTC1600H > MTS9570 > MTS 9500. Sulfuric acid (0.5–1 M) can be efficiently used for the desorption of both iron and cadmium for MTC1600H, while for MTS9570 (phosphonic/sulfonic resin) sulfuric acid correctly desorbs Cd (above 96% at 1 M concentration), contrary to Fe (less than 30%). The aminophosphonic resin shows much poorer efficiency in terms of desorption. The sulfonic resin (i.e., MTC1600H) shows much higher sorption capacity, better selectivity, comparable uptake kinetics (about 2 h equilibrium time), and better metal desorption ability (higher than 98% with 1 M acid concentration, regardless of the type of acid). This conclusion is confirmed by the comparison of removal properties in the treatment of different types of industrial phosphoric acid solutions (crude, and pre-treated H
3
PO
4
solutions). The three resins are inefficient for the treatment of crude phosphoric acid, and activated charcoal pre-treatment (MTC1600H reduced cadmium content by 77%). However, MTC1600H allows removing over 93% of Fe and Cd for H
3
PO
4
pre-treated by TBP solvent extraction, while the others show much lower efficiencies (< 53%).
Diabetic nephropathy (DN) is a serious complication of diabetes mellitus and a common cause of end-stage renal disease. Autophagy has a defensive role against kidney damage caused by hyperglycemia. ...Mesenchymal stem cell (MSC)-derived exosomes are currently considered as a new promising therapy for chronic renal injury. However, the renal-protective mechanism of exosomes on DN is not completely understood. We examined the potential role of MSC-derived exosomes for enhancement of autophagy activity and their effect on DN. In our study, we used five groups of rats: control; DN; DN treated with exosomes; DN treated with 3-methyladenine (3-MA) and chloroquine (inhibitors of autophagy); and DN treated with 3-methyladenine (3-MA), chloroquine, and exosome groups. We assessed renal function, morphology, and fibrosis. Moreover, ratios of the autophagy markers mechanistic target of rapamycin (mTOR), Beclin-1, light chain-3 (LC3-II), and LC3-II/LC3-I were detected. Additionally, electron microscopy was used for detection of autophagosomes.
Exosomes markedly improved renal function and showed histological restoration of renal tissues, with significant increase of LC3 and Beclin-1, and significant decrease of mTOR and fibrotic marker expression in renal tissue. All previous effects were partially abolished by the autophagy inhibitors chloroquine and 3-MA.
We conclude that autophagy induction by exosomes could attenuate DN in a rat model of streptozotocin-induced diabetes mellitus.
Overhanging and floating layers which are introduced during the build in selective laser melting (SLM) process are usually associated with high temperature gradients and thermal stresses. As there is ...no underlying solid material, less heat is dissipated to the powder bed and the melted layer is free to deform resulting undesired effects such as shrinkage and crack. This study uses three-dimensional finite element simulation to investigate the temperature and stress fields in single 316L stainless steel layers built on the powder bed without support in SLM. A non-linear transient model based on sequentially coupled thermo-mechanical field analysis code was developed in ANSYS parametric design language (APDL). It is found that the predicted length of the melt pool increases at higher scan speed while both width and depth of the melt pool decreases. The cyclic melting and cooling rates in the scanned tracks result high VonMises stresses in the consolidated tracks of the layer.
Placenta accreta has been described as a spectrum of abnormal attachment of villous tissue to the uterine wall, ranging from superficial attachment to the inner myometrium without interposing decidua ...to transmural invasion through the entire uterine wall and beyond. These descriptions have prevailed for more than 50 years and form the basis for the diagnosis and grading of accreta placentation. Accreta placentation is essentially the consequence of uterine remodeling after surgery, primarily after cesarean delivery. Large cesarean scar defects in the lower uterine segment are associated with failure of normal decidualization and loss of the subdecidual myometrium. These changes allow the placental anchoring villi to implant, and extravillous trophoblast cells to migrate, close to the serosal surface of the uterus. These microscopic features are central to the misconception that the accreta placental villous tissue is excessively invasive and have led to much confusion and heterogeneity in clinical data. Progressive recruitment of large arteries in the uterine wall, that is, helicine, arcuate, and/or radial arteries, results in high-velocity maternal blood entering the intervillous space from the first trimester of pregnancy and subsequent formation of placental lacunae. Recently, guided sampling of accreta areas at delivery has enabled accurate correlation of prenatal imaging data with intraoperative features and histopathologic findings. In more than 70% of samples, there were thick fibrinoid depositions between the tip of most anchoring villi and the underlying uterine wall and around all deeply implanted villi. The distortion of the uteroplacental interface by these dense depositions and the loss of the normal plane of separation are the main factors leading to abnormal placental attachment. These data challenged the classical concept that placenta accreta is simply owing to villous tissue sitting atop the superficial myometrium without interposed decidua. Moreover, there is no evidence in accreta placentation that the extravillous trophoblast is abnormally invasive or that villous tissue can cross the uterine serosa into the pelvis. It is the size of the scar defect, the amount of placental tissue developing inside the scar, and the residual myometrial thickness in the scar area that determine the distance between the placental basal plate and the uterine serosa and thus the risk of accreta placentation.
Metallic additive manufacturing techniques, in particular the selective laser melting (SLM) process, are capable of fabricating strong, lightweight and complex metallic lattice structures. However, ...they still face certain process limitations such as geometrical constraints and in some cases the need for support structures. This study evaluates the manufacturability and performance of SLM produced periodic cellular lattice structures, which are designed by repeating a unit cell type called gyroid consisting of circular struts and a spherical core. The effect of unit cell size on the manufacturability, density and compression properties of the manufactured cellular lattice structures were investigated. Micro-computer tomography (CT) scan results reveal that the gyroid cellular lattice structures with various unit cell sizes ranging from 2 to 8mm can be manufactured free of defects by the SLM process without the need of additional support structures. The Scanning Electron Microscope (SEM) micrographs show that the lattice structures made by SLM have a good geometric agreement with the original computer-aided design (CAD) models, but many partially melted metal particles are bonded to strut surfaces. The struts within the gyroid cellular lattice structures with smaller unit cell sizes have higher densities due to their shorter scan vector lengths in the SLM process. The yield strength and Young's modulus of the Gyroid cellular lattice structures increase with the decrease in the unit cell size due to the denser struts of the lattice structures with smaller unit cell sizes.
► Cellular lattice structures are generated by a novel unit cell type called “Schoen Gyroid”. ► The lattice structures with a wide unit cell size range were manufactured by SLM. ► Struts within the lattice structures with smaller unit cell sizes have higher densities. ► The yield strengths and Young's moduli both decrease with the increase in unit cell size.
This paper presents a "fully-connected" hybrid beamforming receiver that independently weights each element in an antenna array prior to separate downconversion chains that output independent ...baseband streams. A receiver architecture is introduced, which implements RF-domain complex-valued Cartesian weighting, RF-domain combining, and multi-stream heterodyne complex-quadrature downconversion. Each RF-domain Cartesian weight is implemented by a pair of 5-bit digitally controlled programmable-gain amplifiers, whose outputs are combined with the weighted signals from other antennas prior to complex-quadrature downconversion. Signal combination is performed by a wideband small-footprint distributed active combiner. A 25-30 GHz hybrid beamforming receiver with eight antenna inputs and two baseband output streams is designed in 65-nm CMOS. In each antenna path, the receiver achieves 34-dB conversion gain, 7.3-dB minimum noise figure, and 5 GHz of RF bandwidth. The entire receiver consumes 340 mW (equivalent to 27.5 mW per antenna per stream) including low-noise amplification, RF-domain beamforming, multi-stream downconversion, and local oscillator generation and distribution circuitry. The receiver occupies 3.86 mm 2 excluding pads, equivalent to 0.36 mm 2 per antenna per stream. Single-element characterization results are presented, along with characterization of several spatial processing techniques including interference cancellation (20 dB peak to null for two elements), simultaneous two-stream reception, and adaptive-codebook-search-based beam acquisition.
Environmentally sustainable repair materials with reduced carbon footprint have been in great demand by the construction industry worldwide. Gradual deterioration of concrete containing large ...quantities of Portland cement is inevitable, and requires repair or replacement. Numerous repair materials including cementitious mortars, polymer-modified cementitious mortars, resinous mortars, etc. have been utilized to rectify the problem. Cement-free geopolymer mortars prepared from waste materials with high content of silicate aluminum and alkaline activator solution are emerging as prominent sustainable repair materials. Geopolymer binders are preferred because they generate 70–80% less carbon dioxide with remarkably lesser greenhouse gas emissions than ordinary Portland cement. These new binders are highly sought-after due to their enhanced durability performance, sustainability, and environmental affability. This paper provides a comprehensive overview of state-of-the-art research on sustainable geopolymers for repairing deteriorated and damaged concrete structures as well as restoring their integrity. Present challenges and future prospects of various geopolymer mortars as repair materials are emphasized.
•A unique cell type called gyroid is designed to construct lattice structures.•Curved cell surface as a self-supported feature avoids support structures.•Lattice structures with a wide volume ...fraction range were made.•Lattice structures were made at different orientations.•Strength and modulus increase with the increase in the volume fraction.
This paper investigates the manufacturability and performance of advanced and lightweight stainless steel cellular lattice structures fabricated via selective laser melting (SLM). A unique cell type called gyroid is designed to construct periodic lattice structures and utilise its curved cell surface as a self-supported feature which avoids the building of support structures and reduces material waste and production time. The gyroid cellular lattice structures with a wide range of volume fraction were made at different orientations, showing it can reduce the constraints in design for the SLM and provide flexibility in selecting optimal manufacturing parameters. The lattice structures with different volume fraction were well manufactured by the SLM process to exhibit a good geometric agreement with the original CAD models. The strut of the SLM-manufactured lattice structures represents a rough surface and its size is slightly higher than the designed value. When the lattice structure was positioned with half of its struts at an angle of 0° with respect to the building plane, which is considered as the worst building orientation for SLM, it was manufactured with well-defined struts and no defects or broken cells. The compression strength and modulus of the lattice structures increase with the increase in the volume fraction, and two equations based on Gibson–Ashby model have been established to predict their compression properties.
This research aimed to enhance the nutritional and sensory qualities of Balady bread by adding locally Egyptian buckwheat flours, Fagopyrum esculentum (FE) and Fagopyrum tataricum (FT), to Hard Wheat ...Flour (HWF) 82% extraction at three levels (10%, 20%, and 30%). The chemical composition, rheological properties, color, sensory evaluation and stalling of the balady bread were determined. The chemical composition of raw materials revealed that FE was significantly (P ≤ 0.05) higher in protein and fat contents compared to HWF and FT. While FT was higher in fiber and ash contents. The findings show that a 30% replacement with FE or FT significantly enhances the bread's nutritional profile, notably increasing protein, fiber, ash, and moisture content. Rheological analysis revealed that FE and FT alter dough handling, with a notable improvement in dough stability and mixing tolerance at 30% FT. Sensory evaluation indicated acceptable qualities even at higher substitution levels, although 30% FE showed slight declines in certain attributes. Furthermore, bread supplemented with 30% FT demonstrated slower staling and potentially extended shelf life. These results highlight the potential of FE and FT as nutritional enhancers in bread formulations, with 30% FT emerging as the optimal replacement level for balancing nutritional benefits and sensory acceptance.
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