Contents Of Volume Research Articles

Validation of pathogen reduced plasmas from maxi-pools combined with fast thawing.

Fast thawing for emergency situations and reduction of plasma wastage. Evaluation of plasma units, pooled and pathogen reduced (PR) in "maxi-pools" with amotosalen and UVA light, and fast thawing. Per replicate, 10 WB-derived leukocyte depleted plasma units were frozen within 24 h at ≤ -25°C and stored for 7 days. After thawing, a maxi-pool was constituted from the 10 units. After splitting into 4 sub-pools of 650 mL, the sub-pools were PR treated then split into 3 units resulting in 12 PR plasma units at 200 mL. Hundred and twenty PR plasma units were produced in total. The units were frozen at ≤ -25°C for 1 week, then thawed either in a fast plasma thawer for 5 min or in other control devices (17 to 23 min). C, Fibrinogen, albumin, IgG, protein S and VWF were measured in plasma units, maxi-pools and plasmas after PR treatment and thawing. There was a statistically significant (p < 0.001) but still clinically acceptable (over the recommended levels of ≥0.5 IU/mL and ≥2 g/L) reduction of FVIII:C and Fibrinogen after PR with 69% and 87% recovery, respectively. Other proteins were not significantly affected by the processes. Pooling 10 plasma units before the PR treatment standardises volume and protein content of plasma units. Besides the economic value of generating 12 products for transfusion, this procedure combined with a thawing time of about 5 min is of value in emergency situations and may reduce plasma wastage.

Contents of Volume 74

Contents of Volume 74

GROWTH AND WOOD TRAITS EVALUATION OF 15-YEAR-OLD TENGKAWANG (Shorea spp.) TREE STANDS IN GUNUNG WALAT UNIVERSITY FOREST, WEST JAVA, INDONESIA

Gunung Walat University Forest (GWUF) in Sukabumi Regency, Indonesia, plays a crucial role in providing various ecosystem services. Five important Shorea trees, i.e., S. stenoptera, S. mecisopteryx, S. pinanga, S. palembanica, and Shorea leprosula have been planted in GWUF as an effort for its conservation and object of research. An evaluation of the adaptability and suitability of these species to the GWUF ecosystem, as well as their wood characteristics, needs to be carried out regularly. Therefore, the study aimed to examine the growth performances and physical wood properties of five Shorea species, i.e., Shorea stenoptera, S. mecisopteryx, S. pinanga, S. palembanica, and S. leprosula at the age of 15-year-old planted in GWUF. The results indicated that S. leprosula exhibited the best growth performance in terms of average diameter (19.64 cm), volume (0.27 m3), slenderness (126.58), and wood density (0.94 g/cm3), and S. stenoptera showed the best performance in average height (23.35 m). While the poor performance was shown by S. palembanica in terms of average diameter (6.73 cm), height (11.15 m), volume (0.02 m3), wood density (0.87 g/cm3), and specific gravity (0.45), and S. stenoptera in terms of average slenderness (202.73). In addition, significant differences in tree height, diameter, volume, wood density, specific gravity, and moisture content were found in S. palembanica compared with other species. The relationship between the growth and physical wood properties parameters varied between species. The study revealed that planting the five Shorea species in GWUF is suitable for increasing vegetation cover and conserving the species.

The Flexural Behavior of Reinforced Ultra-High Performance Engineering Cementitious Composite (UHP-ECC) Beams Fabricated with Polyethylene Fiber (Numerical and Analytical Study)

Ultra-high performance engineered cementitious composite (UHP-ECC), which is a new and ductile version of concrete, has attracted researchers recently due to its exceptional mechanical properties: its very high compressive strength (from 100 to 200 MPa) and very high tensile strain capacity (not less than 3% and up to 8%). However, the available experimental literature is small due to its very high cost. To overcome the high cost of the experiments of UHP-ECC, the finite element modeling package ANSYS was used to create a new modeling technique using the Menetrey–Willam constitutive model, recently added to ANSYS. This technique was validated using previous experimental results for UHP-ECC beams and found to be accurate and effective. The previous FE model was used to conduct a parametric study and the variables—the compressive strength of the concrete, the percentage of the volume content of polyethylene fibers, the tensile reinforcement ratio, and the span-to-depth ratio—were found to be effective upon the flexure behavior of the reinforced UHP-ECC beams. As the analysis and design of UHP-ECC beams fabricated with polyethylene fiber are not available yet through design codes, an analytical model including some equations was deduced to calculate the flexure capacity of such beams. The results of the parametric study were used to investigate the validity and accuracy of the analytical model. The proposed equations demonstrated a good estimation compared with the numerical analysis results.

Influence of Gas Oven Temperature on the Microstructure and Extrudability of Al-Mg-Si Aluminium Alloys

The microstructure of Al-Mg-Si aluminium alloys is well characterised when it comes to the initial state of the cast billet or the artificially aged profile. Typically, a gas oven coupled with an induction oven is used to preheat the billets before extrusion. Preheating reduces the flow stress of the aluminium and dissolves the phases that have precipitated during cooling after homogenisation. In this paper, the influence of the gas oven temperature on the partial or complete dissolution of the precipitated phases will be shown. In addition, the negative effect of a wrong choice of parameters on the volume content of the MgSi phases will be shown.

Biodegradable Citrate‐Based Polymers Enable 5D Monitoring of Implant Evolution

AbstractBiodegradable tissue engineering scaffolds have garnered increasing interest for their role in providing mechanical support, promoting tissue regeneration, and eliminating the need for removal. However, the in vivo degradation processes remain challenging to track. Here, a novel biodegradable polymer, N‐methyldiethanolamine (MDEA) and Gadolinium(III) diethylenetriamine pentaacetate (Gd‐DTPA) modified biodegradable photoluminescent polymers (BPLPMGd), which combines near‐infrared (NIR) fluorescence and magnetic resonance (MR) dual‐modality imaging are introduced to monitor scaffold degradation in vivo. The chemical structure of BPLPMGd is characterized and its dual‐imaging properties in vitro are evaluated. Subsequently, non‐invasive dual‐modality imaging to track the degradation of implanted BPLPMGd scaffolds is performed in a rat model, comparing these results with histological data. This approach reveals that BPLPMGd enables reliable non‐invasive tracking of the degradation, where NIR fluorescence imaging offers a qualitative and quantitative analysis of scaffold mass loss, total volume and solid content changes, while magnetic resonance imaging (MRI) details structural and morphological changes, allowing for 5D monitoring of implant degradation, including 3D structure, location, mass, volume, and geometry. The combination of these imaging modalities provides a comprehensive view of scaffold degradation, where the synergistic use of both yields results greater than either modality alone, offering unprecedented 5D information of implantable devices. This innovative approach has potential applications in regenerative engineering and beyond.

Study on Impact Resistance of Alkali-Activated Slag Cementitious Material with Steel Fiber

Alkali-activated slag cementitious materials (AASCMs) use alkaline activators to activate blast furnace slag and waste slag to replace traditional Portland cement, which can reduce CO2 emissions. An impact resistance test and scanning electron microscopy (SEM) microscopic performance analysis of alkali-activated slag cementitious material specimens with four different steel-fiber contents are performed. The effects of steel-fiber volume content and strain rate on the dynamic elastic modulus Ed, dynamic compressive strength σd, dynamic peak compressive strain εc, and energy absorption of the AASCM-SS are studied. The results indicate that the dynamic elastic modulus Ed, dynamic compressive strength σd, and energy absorption of the AASCM-SS increase with the increase of strain rate, and the dynamic peak compressive strain εc decreases with the increase of strain rate. The dynamic elastic modulus Ed, dynamic compressive strength σd, and dynamic peak compressive strain εc of the SS-AASCM increase first and then decrease with the increase of steel-fiber content. When the steel-fiber content is 0.5%, the σd and εc of the AASCM-SS are the highest, increased by 9.9% and 19.3%. The energy absorption of AASCM-SS increases with the increase of steel-fiber content. A dynamic constitutive model of the FR-AASCM considering the influence of damage, strain rate, and steel-fiber volume fraction is established. The proposed constitutive model is in acceptable agreement with the experimental AASCM-SS dynamic stress–strain curve, and the correlation coefficient is 0.91.

A deep learning model optimized by Bayesian Optimization with Hyperband for fast prediction of the elastic properties of 3D tubular braided composites at different temperatures

AbstractThree dimensional (3D) tubular braided composites are widely used in various industries due to their excellent mechanical properties and lightweight characteristics. However, traditional numerical and experimental methods face challenges in predicting mechanical properties quickly and accurately due to factors such as ambient temperature, component materials, and geometric parameters. To address this issue, this paper combines deep neural networks (DNN) and two‐scale finite element analysis to accelerate the solution speed. The dataset is first obtained through a two‐scale finite element model with temperature based on micro‐CT. Then, the mapping model of macroscopic compression elastic properties and the influencing factors of material properties is established by DNN and Bayesian Optimization with Hyperband (BOHB) hyperparameter optimization algorithm. The rapid prediction of axial compression elastic properties of 3D tubular braided composites under different ambient temperatures, component materials, porosities, braiding angles and fiber volume contents is achieved. Finally, the accuracy of the predicted results of the constructed model is verified by experiments.Highlights A BOHB optimized deep learning model coupled with a finite element framework is proposed Fast prediction of elastic properties of 3D tubular braided composites at different temperatures The accuracy of the prediction results of the constructed model is verified by experiments

Effect of water to cement ratio on mechanical properties of FRC subjected to elevated temperatures: Experimental and soft computing approaches

The deterioration of concrete is greatly dependent on the cracks and microcracks development owing to loading or environmental influences. An effective step to avoid the spread of cracks and microcracks is employing of different fibers in concrete and the manufacture of fiber reinforced concrete. On the other hand, fire is one of the cases that always threatens engineering structures. Elevated temperatures cause obvious chemical and physical changes that lead to concrete deterioration. In this study, the effect of adding various fiber with different volume contents in concrete mixture with various cement content was evaluated experimentally. Results indicate that spalling was more dominant in mixture containing steel fiber and with higher amount of cement, while there is not any spalling in mixture containing polypropylene (PP) fibers. Moreover, the reduction in tensile strength of fiber-free concrete specimens is less pronounced in mixtures with higher cement content. In addition, the positive performance of PP fibers compared to steel fibers was proved at higher temperatures and cement contents. Furthermore, by conducting a comprehensive and accurate survey, this research pinpoints gaps in the current literature. Moreover, the gathered dataset serves as input for training a machine learning approach known as Group Method of Data Handling (GMDH). The GMDH network demonstrates a satisfactory accuracy in predicting experimental results, with a MSE of 0.0044.

Buckling analysis and parametric optimization of the metal-composite shell with voids under hydraulic pressure combined with sensitivity analysis

Structural design parameters always impact the buckling properties of the composite shells due to the differences in the anisotropy of the materials and the varying enhancement capabilities of each component. This paper aims to analyze the parametric effect on the buckling load and optimize the design parameters of metal-composite shells with voids under hydraulic pressure. Firstly, the theoretical model of buckling load is established based on the microscopic model of hybrid materials and the Galerkin method. Then, four design parameters including fiber volume content, winding angles, and CNTs volume content are selected to discuss the parametric effect on the critical buckling load. Further, the global sensitivity analysis is conducted to determine the influence rank, and the GA-PSO algorithm is used to confirm the optimal parametric combination. The results imply that the fiber volume content and internal and external helical symmetrical angles significantly affect the buckling load. Besides, The winding layers of internal and external helical symmetrical angles enhance the hydraulic resistance of the anti-symmetric structure. The middle helical layer can be influenced by the outer layer, leading to directional changes in the critical buckling load at an angle of around 50°.

Enhancing Bone Formation Through bFGF-Loaded Mesenchymal Stromal Cell Spheroids During Fracture Healing in Mice.

This study aimed to evaluate the osteogenic potential of mesenchymal stromal cell (MSC) spheroids combined with the basic fibroblast growth factor (bFGF) in a mouse femur fracture model. To begin, MSC spheroids were generated, and the expression of key trophic factors (bFGF Bmp2, and Vegfa) was assessed using quantitative PCR (qPCR). A binding assay confirmed the interaction between the bFGF and the spheroids' extracellular matrix. The spheroid cultures significantly upregulated bFGF, Bmp2, and Vegfa expression compared to the monolayers (p < 0.001), and the binding assay demonstrated effective bFGF binding to the MSC spheroids. Following these in vitro assessments, the mice were divided into five groups for the in vivo study: (1) no treatment (control), (2) spheroids alone, (3) bFGF alone, (4) bFGF-loaded spheroids (bFGF-spheroids), and (5) non-viable (frozen) bFGF-loaded spheroids (bFGF-dSpheroids). Bone formation was analyzed by a micro-CT, measuring the bone volume (BV) and bone mineral content (BMC) of the mice four weeks post-fracture. A high dose of the bFGF (10 µg) significantly promoted bone formation regardless of the presence of spheroids, as evidenced by the increases in BV (bFGF, p = 0.010; bFGF-spheroids, p = 0.006; bFGF-dSpheroids, p = 0.032) and BMC (bFGF, p = 0.023; bFGF-spheroids, p = 0.004; bFGF-dSpheroids, p = 0.014), compared to the controls. In contrast, a low dose of the bFGF (1 µg) combined with the MSC spheroids significantly increased BV and BMC compared to the control (BV, p = 0.012; BMC, p = 0.015), bFGF alone (BV, p = 0.012; BMC, p = 0.008), and spheroid (BV, p < 0.001; BMC, p < 0.001) groups. A low dose of the bFGF alone did not significantly promote bone formation (p > 0.05). The non-viable (frozen) spheroids loaded with a low dose of the bFGF resulted in a higher BV and BMC compared to the spheroids alone (BV, p = 0.003; BMC, p = 0.017), though the effect was less pronounced than in the viable spheroids. These findings demonstrate the synergistic effect of the bFGF and MSC spheroids on bone regeneration. The increased expression of the BMP-2 and VEGF observed in the initial experiments, coupled with the enhanced bone formation in vivo, highlight the therapeutic potential of this combination. Future studies will aim to elucidate the underlying molecular mechanisms and assess the long-term outcomes for bone repair strategies.

Integrated uses of organic and inorganic fertilisers to increase sesame productivity on coastal sand fields

Sesame is recognised as a valuable oil plant with potential health benefits due to its disease mitigating properties. It shows exceptional growth rates in light soil types, such as sandy beach soils which are often deemed infertile. To address the issue, it is necessary to apply eco-friendly fertilisers derived from animal manure. Consequently, research has focused on performance evaluation over two growing seasons, namely the dry and rainy seasons, on coastal sandy soils. Employing a split-plot design across three replicates, the study investigated the influence of planting time and cultivar on the growth and yield of sesame. The study aimed to assess the impact of mixed fertiliser application timing on sesame growth and yield, focusing on both quantitative and qualitative parameters across the rainy and dry seasons. Results indicated that applying a mixture comprising chicken manure and inorganic fertiliser at the planting time significantly affected several growth parameters. These included plant height, chlorophyll content, flowering time, number of branches, net assimilation rate, root volume, and total sesame oil content, particularly in the dry season. Specifically, employing a dosage of 24.75 g of inorganic NPK fertiliser, comprising 1.45 g of nitrogen, 0.74 g of phosphorus, and 1.25 g of potassium per plant at planting time during the dry season, demonstrated the most favourable outcomes in terms of growth, yield components, and soil fertility. This approach also yielded a remarkable 54.51% oil content in the cultivar ‘Sbr-1’.

Very high cycle fatigue behavior of TC4 titanium alloy: Faceting cracking mechanism and life prediction based on dislocation characterization

This research analyzes the very-high-cycle-fatigue behavior of TC4 titanium alloy through fatigue tests at R = −1, −0.3, and 0.1. The results show that the S-N curves are all bilinear and exhibit three failure modes as surface slip failure, surface cleavage failure and interior cleavage failure. Transmission electron microscopy analysis reveals the dislocation structure in interior cleavage failure and suggests that the deformation mechanism of faceting cracking involves both anti-phase boundary shearing and stacking fault shearing mechanisms. It concludes that interior failure results from cleavage fracture of α grains due to dislocation slip. Based on the stress intensity factor of the maximum defect, a slip-cleavage competitive failure model was developed by considering factors such as control volume, defect size, external loading, and grain content, with good predictive results. Additionally, on the basis of the failure mechanism and crack propagation rate model, considering the coupled effects of crack tip blunting, stress ratio, Vickers hardness, and material fracture toughness on crack propagation, the crack propagation life prediction model is constructed. The life prediction model is further modified to be more conservative and accurate in predicting life by consideration the maximum defect size, providing important theoretical support and practical guidance for engineering applications.

The Influence and Mechanism of Polyvinyl Alcohol Fiber on the Mechanical Properties and Durability of High-Performance Shotcrete

This study investigates the impact of polyvinyl alcohol (PVA) fibers on the mechanical properties and durability of high-performance shotcrete (HPS). Results demonstrate that PVA fibers have a dual impact on the performance of HPS. Positively, PVA fibers enhance the tensile strength and toughness of shotcrete due to their intrinsic high tensile strength and fiber-bridging effect, which significantly improves the material’s splitting tensile strength, deformation resistance, and toughness, and the splitting tensile strength and peak strain have been found to be increased by up to 30.77% and 31.51%, respectively. On the other hand, the random distribution and potential agglomeration of PVA fibers within the HPS matrix can lead to increased air-void formations. This phenomenon raises the volume content of large bubbles and increases the average bubble area and diameter, thereby elevating the pore volume fraction within the 500–1200 μm and &gt;1200 μm ranges. Therefore, these microstructural changes reduce the compactness of the HPS matrix, resulting in a decrease in compressive strength and elastic modulus. The compressive strength exhibited a reduction ranging from 10.44% to 15.11%, while the elastic modulus showed a decrease of between 8.09% and 12.67%. Overall, the PVA-HPS mixtures with different mix proportions demonstrated excellent frost resistance, chloride ion penetration resistance, and carbonation resistance. The electrical charge passed ranged from 133 to 370 C, and the carbonation depth varied between 2.04 and 6.12 mm. Although the incorporation of PVA fibers reduced the permeability and carbonation resistance of shotcrete, it significantly mitigated the loss of tensile strength during freeze–thaw cycles. The findings offer insights into optimizing the use of PVA fibers in HPS applications, balancing enhancements in tensile properties with potential impacts on compressive performance.

Recent Advances in Barium Cobaltite-Based Perovskite Oxides as Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells.

Solid oxide fuel cells (SOFCs) are considered as advanced energy conversion technologies due to the high efficiency, fuel flexibility, and all-solid structure. Nevertheless, their widespread applications are strongly hindered by the high operational temperatures, limited material selection choices, inferior long-term stability, and relatively high costs. Therefore, reducing operational temperatures of SOFCs to intermediate-temperature (IT, 500-800°C) range can remarkably promote the practical applications by enabling the use of low-cost materials and enhancing the cell stability. Nevertheless, the conventional cathodes for high-temperature SOFCs display inferior electrocatalytic activity for oxygen reduction reaction (ORR) at reduced temperatures. Barium cobaltite (BaCoO3-δ)-based perovskite oxides are regarded as promising cathodes for IT-SOFCs because of the high free lattice volume and large oxygen vacancy content. However, BaCoO3-δ-based perovskite oxides suffer from poor structural stability, inferior thermal compatibility, and insufficient ionic conductivity. Herein, an in-time review about the recent advances in BaCoO3-δ-based cathodes for IT-SOFCs is presented by emphasizing the material design strategies including functional/selectively doping, deficiency control, and (nano)composite construction to enhance the ORR activity/durability and thermal compatibility. Finally, the currently existed challenges and future research trends are presented. This review will provide valuable insights for the development of BaCoO3-δ-based electrocatalysts for various energy conversion/storage technologies.

Association Between Zinc Ion Concentrations in Seminal Plasma and Sperm Quality: A Chinese Cross-Sectional Study.

This study investigates the impacts of zinc ion concentration in in seminal plasma and the total amount of Zn2+ per ejaculation on sperm quality evaluation parameters. In addition, we assessed the reliability of using zinc content in seminal plasma to evaluate sperm quality. We analyzed semen from 964 men and found that men over 40years old had significantly lower concentrations of Zn2+ in ejaculated semen compared to other age groups (p < 0.05), with no significant difference in Zn2+ concentrations among other age groups (p > 0.05). The total amount of Zn2+ in one ejaculation did not show a statistical difference between the normal semen and the abnormal semen groups (p > 0.05). Statistical differences were observed in sperm kinetic parameters and DNA fragmentation index between the normal Zn2+ total amount group and the abnormal group (p < 0.05). However, there was no statistical difference in morphological parameters (p > 0.05). Spearman correlation analysis showed a negative correlation between Zn2+ concentrations in seminal plasma, age, and sperm fructose and a positive correlation between semen volume, abstinence time, sperm concentration, neutral α-glycosidase, and citric acid content (p < 0.05). The receiver operating characteristic curve analysis demonstrated that Zn2+ concentrations had poor accuracy and specificity in assessing sperm quality (p > 0.05). Although there is a partial correlation between Zn2+ concentrations in seminal plasma and certain semen quality parameters, relying solely on Zn2+ concentrations to evaluate sperm quality lacks accuracy and specificity.

Gasification of multi-layer porous fuels in low-temperature gas generator for flying vehicle

The paper is aimed at investigating the influence of porous fuel layering on the operating regimes and performance of a low-temperature gas generator for high-speed flying vehicles equipped with a ramjet engine. The gas generator consists of a propellant and a porous fuel arranged sequentially to generate hydrocarbon gases that cool the engine before burning in the combustion chamber. In this paper, using a novel numerical model, gasification of multi-layer solid porous fuels consisting of polymethylmethacrylate (PMMA) and polyethylene (PE) is studied for various volume contents and relative arrangements of fuel parts. It is shown that during the gasification of the multi-layer fuels, several gasification waves can simultaneously occur in the gas generator. The operating time of the gas generator depends on the relative sizes and relative location of the PMMA and PE layers, and an increase in the number of layers leads to a decrease in the influence of their relative arrangement on the process. Thus, during the gasification of two-component multi-layer solid porous fuel, the composition of this fuel, i.e., the relative sizes of the layers and their relative arrangement, can be the control parameter that allows one to choose the desired characteristics of the gasification process.

A mesoscopic numerical analysis method for evaluating the electromagnetic transmission performance of cement mortar with varying sand particle sizes and content

This paper explores the impact of sand content and particle size on the electromagnetic transmission performance (ETP) of mortar samples. This study involves designing mortar samples with a water-cement ratio of 0.4 and varying sand volume content from 0 % to 50 %. Additionally, a mesoscopic finite element model is established to analyze the electromagnetic transmission behavior. The findings indicate that the particle size and content of sand influence the multiple reflections behavior of electromagnetic waves, while the particle size of sand has almost no effect on the electromagnetic transmission coefficient and dielectric response. Although sand enhances the ETP of cement paste, its impact is limited. Furthermore, the study reveals that the distribution of the electromagnetic field remains continuous regardless of sand particle size or content, and is unaffected by the differing dielectric properties of sand and cement paste phases. However, the induced current generated by sand and other phases differs, leading to noticeable variations in dielectric loss. Mesoscopic simulation results clearly demonstrate that cement paste is the primary contributor to electromagnetic energy loss.

Study on the deterioration mechanism of hybrid basalt-polypropylene fiber-reinforced concrete under sulfate freeze-thaw cycles

This paper focuses on the deterioration mechanism of hybrid basalt-polypropylene fiber-reinforced concrete (HBPRC) under the coupling of sulfate freeze-thaw cycles. The changes in the macroscopic properties of HBPRC under the influence of different volume contents of basalt fiber (BF), polypropylene fiber (PF) and hybrid BF-BF were investigated. The microstructure of HBPRC was characterized using the nuclear magnetic resonance (NMR) technique, X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the deterioration models of the BF- matrix interfacial transition zone (BF-ITZ) and the PF- matrix interfacial transition zone (PF-ITZ) in HBPRC were developed. The results showed that the fibers effectively reduced the cracking and macroscopic property damage induced by sulfate freeze-thaw cycles as the number of freeze-thaw cycles increased. When both BF and PF volume contents are mixed at 0.05 %, they can produce complementary effects, and their formation of a uniformly distributed three-dimensional mesh structure is more conducive to reducing the damage to the concrete, and their relative dynamic modulus of elasticity and compressive strength after 300 times of sulfate freeze-thaw cycles were increased by 67.10 % and 46.92 % compared with control concrete. At the same time, the addition of fibers resulted in a more stable evolution of the pore structure of the concrete, and the porosity of the specimens with fibers added at a volume admixture of 0.05 % and 0.1 % was reduced by 13.69–21.35 % after 300 cycles of sulfate freeze-thaw cycling, compared with control concrete. From the BF-ITZ and PF-ITZ deterioration models, it was concluded that the differences in the bonding performance of BF and PF to the concrete matrix affected the degree of frost damage to which they were subjected to coupling and the efficiency of salt solution replenishment, which in turn led to differences in the damage of each group of HBPRC. The reliability of the model was further verified by SEM observation of the morphological changes of different fiber-matrix ITZs before and after sulfate freeze-thaw cycles.

Novel injectable polypeptide nanoparticle encapsulated siRNA targeting TGF-β1 and COX-2 for localized fat reduction I: Preclinical invitro and animal models.

Obesity and localized fat accumulation continue to drive the demand for minimally invasive body contouring technologies including injectable compounds for local fat reduction. siRNA offers a potential for an injectable to specifically target and silence genes involved in adipogenesis with minimal inflammatory side effects. This study evaluates the efficacy of STP705, an injectable containing siRNA encapsulated within histidine-lysine polypeptide (HKP) nanoparticles targeting transforming growth factor β1 (TGF-β1) and cyclooxygenase-2 (COX-2), crucial mediators in adipocyte differentiation and fat retention, using invitro, porcine, and murine models. In vitro experiments on mouse preadipocytes and invivo trials using Diet Induced Obese (DIO) mice and Yucatan minipigs were conducted to assess the gene silencing efficiency, tissue localization, pharmacodynamics, and safety profile of STP705. STP705 effectively reduced the expression of TGF-β1 and COX-2, with a notable decrease in adipocyte volume and lipid content without adverse systemic effects. In DIO mice, the HKP-siRNA complex demonstrated precise localization to injected adipose tissue, maintaining significant gene silencing, and detectable levels of siRNA for up to 14 days post-administration. Similar results in minipigs showed a significant reduction in subcutaneous adipose tissue thickness. The results of these studies support the use of targeted siRNA therapy specifically targeting TGF-β1 and COX-2, for localized fat reduction, offering a potential minimally invasive alternative to current fat reduction methods.