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Abstract Ultraflat metal foils are essential for semiconductor nanoelectronics applications and nanomaterial epitaxial growth. Numerous efforts have been devoted to metal surface engineering studies in the past decades. However, various challenges persist, including size limitations, polishing non-uniformities, and undesired contaminants. Thus, further exploration of advanced metal surface treatment techniques is essential. Here, we report a physical strategy that utilizes surface acoustic wave assisted annealing to flatten metal foils by eliminating the surface steps, eventually transforming commercial rough metal foils into ultraflat substrates. Large-area, high-quality, smooth 2D materials, including graphene and hexagonal boron nitride (hBN), were successfully grown on the resulting flat metal substrates. Further investigation into the oxidation of 2D-material-coated metal foils, both rough and flat, revealed that the hBN-coated flat metal foil exhibits enhanced anti-corrosion properties. Molecular dynamics simulations and density functional theory validate our experimental observations.

Abstract This paper investigates the predictive relationships among climate policy uncertainty (CPU), oil prices, and renewable energy (RE) stock market returns, particularly highlighting the challenges posed by the varying data frequencies of these variables. The study utilizes a comprehensive dataset comprising monthly CPU, daily oil prices, and RE stock returns, sourced globally. By applying a mixed-frequency causality test (MFCT), the analysis reveals significant predictability across different time horizons, particularly highlighting the strong influence of oil prices on RE stock returns over short-term horizons, while CPU demonstrates a more pronounced effect over medium to long-term horizons. In contrast, the application of the classical Granger causality test on low-frequency (monthly) data indicates an insignificant relationship between CPU and RE stocks, suggesting that traditional models may overlook important predictive dynamics. The analysis was conducted using Matlab code, and the findings provide valuable insights for policymakers in designing effective climate policies and for investors in optimizing portfolio strategies and hedging against risks.

Abstract Hexagonal boron nitride (hBN), as one of the few two-dimensional insulators, holds strategic importance for advancing post-silicon electronic devices and circuits. Achieving wafer-scale, high-quality monolayer hBN is essential for its integration into the semiconductor industry. However, the physical mechanisms behind the chemical vapor deposition (CVD) synthesis of hBN are not yet well understood. Investigating morphology engineering is critical for developing scalable synthetic techniques for the large-scale production of high-quality hBN. In this study, we explored the underlying mechanisms of the CVD growth process of hBN and found that the involvement of a small amount of oxygen effectively modulates the shape of the single-crystal hBN islands. By tuning the oxygen content in the CVD system, we synthesized well-aligned hexagonal hBN islands and achieved a continuous, high-quality single-crystal monolayer hBN film through the merging of these hexagonal islands on conventional single-crystal metal-foil substrates. Density functional theory was used to study the edges of hBN monolayers grown in an oxygen-assisted environment, providing insights into the formation mechanism. This study opens new pathways for controlling the island shape of 2D materials and establishes a foundation for the industrial-scale production of high-quality, large-area, single-crystal hBN.

Since the COVID pandemic, universities propose online education to ensure learning continuity. However, the insufficient preparation led to a major drop in the learner's performance and his/her dissatisfaction with the learning experience. This may be due to several reasons, including the insensitivity of the virtual learning environment to the learner's preferences. We propose to address the issue of student's dissatisfaction and lack of interaction, by integrating learning style theory into the analysis of the learner's online behavior. Our work differentiates itself from the rest of researches that employed learning style theory by its two step process. First, we classify the learning activities into learning categories based on learning style theory. Second, we define behavioral features that quantify the learner's behavior across the learning categories. The analysis of the learner's online behavior based on the behavioral features revealed new aspects of the learner's preferences. We consider these findings to be best useful for developing learning style-sensitive adaptive learning environments. Nevertheless, the behavioral features could be beneficial in different contexts. In fact, when applied to course outcome prediction, the behavioral features enhanced the results by 10%. The latter indicates that behavioral features reflected the correlation between behavior and academic performance.

We report an uncommon clinical presentation of a placental site trophoblastic tumor. The patient presented initially with abdominal pain with, fever, bleeding and pelvic mass on ultrasonography leading to the wrong diagnosis of a pelvic abscess. Dilation and curettage were performed and pathological examination confirmed the diagnosis of placental site trophoblastic tumor. Therefore, she underwent abdominal hysterectomy. Four years after surgery, the patient is still disease free. Gestational trophoblastic diseases should be considered in every patient presenting abnormal uterine bleeding after delivery or pregnancy loss despite the associated symptoms being very unusual.

We report an uncommon clinical presentation of a placental site trophoblastic tumor. The patient presented initially with abdominal pain with, fever, bleeding and pelvic mass on ultrasonography leading to the wrong diagnosis of a pelvic abscess. Dilation and curettage were performed and pathological examination confirmed the diagnosis of placental site trophoblastic tumor. Therefore, she underwent abdominal hysterectomy. Four years after surgery, the patient is still disease free. Gestational trophoblastic diseases should be considered in every patient presenting abnormal uterine bleeding after delivery or pregnancy loss despite the associated symptoms being very unusual.

The abstract highlights the global issue of environmental contamination caused by organic compounds and the exploration of various methods for its resolution. One such approach involves the utilization of titanium dioxide (TiO2) as a photocatalyst in conjunction with natural adsorption materials like kaolin. The study employed a modeling-based approach to investigate the sustainable photocatalytic degradation of acidic dyes using a Jordanian nano-kaolin–TiO2 composite material and solar energy. Mechanistic insights were gained through the identification of the dominant reactive oxygen species (ROS) involved in the degradation process, as well as the synergetic effect between adsorption and photocatalysis. The Jordanian nano-kaolin–TiO2 composite was synthesized using the sol-gel method and characterized. The nanocomposite photocatalyst exhibited particle sizes ranging from 27 to 41 nm, with the TiO2 nanoparticles well-dispersed within the kaolin matrix. The efficacy of this nanocomposite in removing Congo-red dye was investigated under various conditions, including pH, initial dye concentration, and photocatalyst amount. The optimal conditions for dye removal were found to be at pH 5, with an initial dye concentration of 20 ppm, and using 0.1 g of photocatalyst, resulting in a 95 % removal efficiency. The mechanistic insights gained from this study indicate that the hydroxyl radicals (•OH) generated during the photocatalytic process play a dominant role in the degradation of the acidic dye. Furthermore, the synergetic effect between the adsorption of the dye molecules onto the photocatalyst surface and the subsequent photocatalytic degradation by the ROS was found to enhance the overall removal efficiency. These findings contribute to the fundamental understanding of the photodegradation mechanisms and guide the development of more efficient photocatalytic systems for the treatment of acidic dye-containing wastewater. The use of solar power during the purification procedure also leads to cost reduction and strengthens sustainability efforts.

Abstract The α-molybdenum trioxide has attracted much attention for proton storage owing to its easily modified bilayer structure, fast proton insertion kinetics, and high theoretical specific capacity. However, the fundamental science of the proton insertion mechanism in α-molybdenum trioxide has not been fully understood. Herein, we uncover a three-proton intercalation mechanism in α-molybdenum trioxide using a specially designed phosphoric acid based liquid crystalline electrolyte. The semiconductor-to-metal transition behavior and the expansion of the lattice interlayers of α-molybdenum trioxide after trapping one mole of protons are verified experimentally and theoretically. Further investigation of the morphology of α-molybdenum trioxide indicates its fracture behavior upon the proton intercalation process, which creates diffusion channels for hydronium ions. Notably, the observation of an additional redox behavior at low potential endows α-molybdenum trioxide with an improved specific discharge capacity of 362 mAh g−1.

We report an uncommon clinical presentation of a placental site trophoblastic tumor. The patient presented initially with abdominal pain with, fever, bleeding and pelvic mass on ultrasonography leading to the wrong diagnosis of a pelvic abscess. Dilation and curettage were performed and pathological examination confirmed the diagnosis. of placental site trophoblastic tumor. Therefore, she underwent abdominal hysterectomy. Four years after surgery, the patient is still disease free. Gestational trophoblastic diseases should be considered in every patient presenting abnormal uterine bleeding after delivery or pregnancy loss despite the associated symptoms being very unusual.

In the quest for advanced materials with diverse applications in optoelectronics and energy storage, we delve into the fascinating world of halide perovskites, focusing on SiAuF3 and SiCuF3. Employing density functional theory (DFT) as our guiding light, we conduct a comprehensive comparative study of these two compounds, unearthing their unique structural, electronic, elastic, and optical attributes. Structurally, SiAuF3 and SiCuF3 reveal their cubic nature, with SiCuF3 demonstrating superior stability and a higher bulk modulus. Electronic investigations shed light on their metallic behavior, with Fermi energy levels marking the boundary between valence and conduction bands. The band structures and density of states provide deeper insights into the contributions of electronic states in both compounds. Elastic properties unveil the mechanical stability of these materials, with SiCuF3 exhibiting increased anisotropy compared to SiAuF3. Our analysis of optical properties unravels distinct characteristics. SiCuF3 boasts a higher refractive index at lower energies, indicating enhanced transparency in specific ranges, while SiAuF3 exhibits heightened reflectivity in select energy intervals. Further, both compounds exhibit remarkable absorption coefficients, showcasing their ability to absorb light at defined energy thresholds. The energy loss function (ELF) analysis uncovers differential absorption behavior, with SiAuF3 absorbing maximum energy at 6.9 eV and SiCuF3 at 7.2 eV. Our study not only enriches the fundamental understanding of SiAuF3 and SiCuF3 but also illuminates their potential in optoelectronic applications. These findings open doors to innovative technologies harnessing the distinctive qualities of these halide perovskite materials. As researchers seek materials that push the boundaries of optoelectronics and energy storage, SiAuF3 and SiCuF3 stand out as promising candidates, ready to shape the future of these fields.

Eosinophilic ascites is a rare disorder, reported in both adult and pediatric patients, characterized by high eosinophil counts in the peritoneal fluid. Eosinophilic ascites appears as a manifestation of various diseases such as parasitic and fungal infections, malignancy, and hypereosinophilic syndrome. It also represents an uncommon manifestation of eosinophilic gastroenteritis, usually treated with corticosteroids. We present the case of a 16-year-old woman with abdominal distention related to abundant ascites. Further work-up concluded that it was eosinophilic gastroenteritis complicated with eosinophilic ascites. The patient was on oral steroids for three weeks, but various abdominal relapses were observed, leading to the introduction of benralizumab, as a steroid-sparing therapy with a favorable outcome.

The role of Ce one Mn-based catalysts for the selective catalytic reduction of NOx at low temperature is an ongoing debate. Here the authors demonstrate that Ce has a structural promoting effect but impacts negatively on the intrinsic catalytic activity of Mn.