This paper presents the design and realization of a metasurface-based low-profile wideband Circularly Polarized (CP) patch antenna with high performance for Fifth-generation (5G) communication ...systems. The antenna consists of a modified patch, sandwiched between an array of 4 x 4 symmetrical square ring Metasurface (MTS) and a ground plane. Initially, the intrinsic narrow bandwidth of the conventional patch antenna is increased using a diagonal rectangular slot. For further performance enhancement, the additional resonances and CP radiations are achieved for wideband operation in terms of impedance and Axial Ratio (AR) by effective excitation of surface waves propagating along the MTS. The stacking of MTS on the modified patch without any air gap resulted in an overall compact size of 1.1λ0x 1.1λ0 x 0.093λ0. Simulated and measured results show that the MTS-based antenna offers a wide impedance bandwidth ranging from 24 - 34.1 GHz (34.7%) for |S11| <; -10 with a maximum gain of 11 dBic and a 3-dB AR bandwidth of 24.1 - 29.5 GHz (20.1 %). Moreover, the proposed antenna has a smooth gain response with a small variation in its gain (9.5 - 11 dBic) and a stable left-hand CP radiation in the desired frequency range. The operating bandwidth of this antenna is covering the proposed entire global millimeter-wave spectrum (24.2 - 29.5 GHz) for 5G communication systems.
The goal of the study was to determine whether endoscopic ultrasound (EUS)-guided biliary drainage (EUS-BD) is comparable to conventional transpapillary stenting with endoscopic retrograde ...cholangiopancreatography (ERCP) in palliation of malignant distal biliary obstruction. Although ERCP for the palliation of malignant biliary obstruction is the standard of care, post-procedure pancreatitis and stent dysfunctions are not uncommon. While EUS-BD has garnered interest as a viable alternative when ERCP is impossible, its role as a primary palliation of malignant distal biliary obstruction is yet to be proven.
We performed random allocation to EUS-BD or ERCP in 125 patients with unresectable malignant distal biliary obstruction at four tertiary academic referral centers in South Korea.
Technical success rates were 93.8% (60/64) for EUS-BD and 90.2% (55/61) for ERCP (difference 3.6%, 95% 1-sided confidence interval lower limit -4.4%, P = 0.003 for noninferiority margin of 10%). Clinical success rates were 90.0% (54/60) in EUS-BD and 94.5% (52/55) in ERCP (P = 0.49). Lower rates of overall adverse events (6.3% vs 19.7%, P = 0.03) including post-procedure pancreatitis (0 vs 14.8%), reintervention (15.6% vs 42.6%), and higher rate of stent patency (85.1% vs 48.9%) were observed with EUS-BD. EUS-BD was also associated with more preserved quality of life (QOL) than transpapillary stenting after 12 weeks of the procedure.
This study demonstrated comparable technical and clinical success rates between EUS-BD and ERCP in relief malignant distal biliary obstruction. Substantially longer duration of patency coupled with lower rates of adverse events and reintervention, and more preserved QOL were observed with EUS-BD (cris.nih.go.kr, Identifier: KCT0001396, https://cris.nih.go.kr/cris/search/search_result_st01_en.jsp?seq=9716<ype=&rtype= ).
A high‐performance, transparent, and extremely thin (<15 nm) hydrogen (H2) gas sensor is developed using 2D electron gas (2DEG) at the interface of an Al2O3/TiO2 thin film heterostructure grown by ...atomic layer deposition (ALD), without using an epitaxial layer or a single crystalline substrate. Palladium nanoparticles (≈2 nm in thickness) are used on the surface of the Al2O3/TiO2 thin film heterostructure to detect H2. This extremely thin gas sensor can be fabricated on general substrates such as a quartz, enabling its practical application. Interestingly, the electron density of the Al2O3/TiO2 thin film heterostructure can be tailored using ALD process temperature in contrast to 2DEG at the epitaxial interfaces of the oxide heterostructures such as LaAlO3/SrTiO3. This tunability provides the optimal electron density for H2 detection. The Pd/Al2O3/TiO2 sensor detects H2 gas quickly with a short response time of <30 s at 300 K which outperforms conventional H2 gas sensors, indicating that heating modules are not required for the rapid detection of H2. A wide bandgap (>3.2 eV) with the extremely thin film thickness allows for a transparent sensor (transmittance of 83% in the visible spectrum) and this fabrication scheme enables the development of flexible gas sensors.
A high‐performance, transparent, and extremely thin (≈15 nm) hydrogen (H2) gas sensor is developed using 2D electron gas at the interface of an Al2O3/TiO2 thin film heterostructure. This extremely thin gas sensor can be fabricated on general substrates such as a glass using atomic layer deposition, and this fabrication scheme enables the development of flexible gas sensors.
The thermally induced phase separation (TIPS) method is regaining momentum as a competitive platform to fabricate highly porous microporous membranes. In membrane technology, there has been an active ...search for more sustainable ways to fabricate polymeric membranes using green solvents. Rhodiasolv PolarClean® is a recently identified environmentally friendly TIPS solvent that shows high potential for the preparation of microporous PVDF membranes. Interestingly, its high miscibility with water induces a nonsolvent-induced phase separation (NIPS) effect on the membrane surface and this simultaneous NIPS-TIPS effect is referred to as the combined NIPS-TIPS (N-TIPS) method. In this work, a thorough investigation was carried out to understand the underlying phenomena in the membrane formation kinetics during the N-TIPS process. It was found that the NIPS and TIPS morphology can be tailored to control the mechanical properties, pore size distribution, and flux of the prepared membranes. For instance, increasing the coagulation bath solvent concentration facilitated the formation of a spherulitic morphology, whereas increasing the bath temperature induced the formation of a bicontinuous morphology free of macrovoids. It was determined that by controlling the phase separation kinetics, the mechanical properties of the prepared PVDF membranes could be remarkably improved from 0.9MPa to 6.1MPa. Several pore-forming additives including polyvinylpyrrolidone, Pluronics F-127, LiCl, and glycerol were employed to induce surface pores and their effects were thoroughly characterized. The membranes prepared with Pluronic additives exhibited high water permeabilities up to 2800Lm−2h−1bar−1 with narrow pore size distributions.
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•Microporous PVDF membranes were prepared via TIPS using an environmental friendly solvent.•The NIPS effect on membrane surface during TIPS process was investigated in detail.•Pluronic F127 additive was found to be an effective pore forming agent.
Ischaemic heart disease (IHD) is the leading cause of death worldwide. Although myocardial cell death plays a significant role in myocardial infarction (MI), its underlying mechanism remains to be ...elucidated. To understand the progression of MI and identify potential therapeutic targets, we performed tandem mass tag (TMT)-based quantitative proteomic analysis using an MI mouse model. Gene ontology (GO) analysis and gene set enrichment analysis (GSEA) revealed that the glutathione metabolic pathway and reactive oxygen species (ROS) pathway were significantly downregulated during MI. In particular, glutathione peroxidase 4 (GPX4), which protects cells from ferroptosis (an iron-dependent programme of regulated necrosis), was downregulated in the early and middle stages of MI. RNA-seq and qRT-PCR analyses suggested that GPX4 downregulation occurred at the transcriptional level. Depletion or inhibition of GPX4 using specific siRNA or the chemical inhibitor RSL3, respectively, resulted in the accumulation of lipid peroxide, leading to cell death by ferroptosis in H9c2 cardiomyoblasts. Although neonatal rat ventricular myocytes (NRVMs) were less sensitive to GPX4 inhibition than H9c2 cells, NRVMs rapidly underwent ferroptosis in response to GPX4 inhibition under cysteine deprivation. Our study suggests that downregulation of GPX4 during MI contributes to ferroptotic cell death in cardiomyocytes upon metabolic stress such as cysteine deprivation.
The membrane market has grown rapidly over the past several decades, supported by continuous improvements in membrane performance, module and process design, and fouling control. However, such growth ...will be unsustainable with current membrane fabrication methods that employ significant amounts of toxic solvents (e.g., N-methylpyrrolidone, dimethylacetamide, and dimethylformamide), thereby producing billions of liters of contaminated wastewater each year. A possible solution is to identify greener alternatives with appropriate properties that are compatible with conventional polymers. In this work, we employed a novel green solvent, Rhodiasolv PolarClean®, that is less toxic than current solvents and eco-friendly, while exhibiting the necessary properties to be employed as a solvent for membrane preparation via the nonsolvent-induced phase separation (NIPS) method. Rhodiasolv PolarClean® has been successfully applied to membrane preparation for water desalination and reclamation by ultrafiltration (UF) and nanofiltration (NF) with conventional polymers, including polysulfone (PSF), polyethersulfone (PES), and cellulose acetate (CA). The UF membranes prepared from PES/Pluronic F127 and PSF/polyvinylpyrrolidone exhibited pure water permeabilities greater than 314.5 ± 57.8 L m−2 h−1 bar−1 and tensile strength 3.78 ± 0.12 MPa with BSA rejection of 98.1 ± 0.4%. Cellulose acetate membrane used for NF applications demonstrated pure water permeability of 1.5 ± 0.25 L m−2 h−1 bar−1 with NaCl and MgCl2 rejection of 85.1 ± 5.7% and 93.2 ± 4.7%, respectively. The performance of the prepared membranes was competitive with current state-of-the-art membranes across all applications, indicating immediate applicability to improving the sustainability of membrane fabrication processes.
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•A commercially available “green” solvent called PolarClean® was applied for UF and NF membrane fabrication.•PES, PSF, and CA membranes with asymmetric structures for fast water treatments were prepared by NIPS.•Morphology was investigated controlling thermodynamics of polymer/solvent/nonsolvent in PolarClean® solvent.•Membrane performance in water processing was highly competitive with other membranes reported.
Most nanotechnology applications for food packaging involve the use of silver nanoparticles or nanoclay. However, other nanomaterials can also be incorporated into packaging. Metal oxide ...nanoparticles have been added to petroleum-based and biopolymers to produce nanocomposites with enhanced mechanical and barrier properties, and their antimicrobial effects have also been reported. However, migration of nanoparticles from packaging is of concern because of their potential toxicity in the human body and the environment.
This review focuses on the application of metal oxide-based nanoparticles for producing nanocomposites. Advantages of incorporating metal oxide-based nanoparticles into polymers are presented, and migration of these nanomaterials from packaging into foods is discussed. Furthermore, an overview of the regulations for nanomaterials in packaging is presented.
Addition of metal oxide nanoparticles into polymers allows for the production of nanocomposites with increased mechanical strength and water and oxygen barrier properties, and can also confer other benefits including antimicrobial activity and light-blocking properties. Migration studies have demonstrated that only a negligible amount of nanomaterial migrates from packaging into food simulants or foods, suggesting that consumer exposure to these nanomaterials and its associated health risks would be low. However, the regulatory framework for nanomaterials in packaging is still underdeveloped even in major economies.
•Review of applications of oxide nanoparticles in packaging and their migration.•Nano-oxide incorporation improves the mechanical and barrier properties of polymers.•Nanocomposites incorporating TiO2, ZnO, CuO have shown antimicrobial properties.•Migration from nanocomposites to foods and simulants is negligible.•Current regulations on the use of nanomaterials for packaging are limited.
Microporous polyvinylidene difluoride (PVDF) hollow fiber membranes were fabricated via a thermally-induced phase separation (TIPS) method using an environmental-friendly hydrophobic solvent, acetyl ...tributyl citrate (ATBC, tradename Citroflex® A4). To maximize membrane tensile strength, the TIPS method was fully utilized by spinning fibers with high polymer content. It was observed that the fiber quality was significantly affected by the dope and bore flow rates and compositions, and an appropriate spinning range was established. The prepared membranes were subsequently stretched to tune the porosity, mean pore size, permeability, tensile strength, and fiber strain. A design of experiment (DOE) analysis was conducted using a 3-factor quadratic model to optimize the stretching conditions and to understand the effects of the parameters and interactions thereof. The permeability of the stretched membranes improved by a factor of 35 (15.1–538Lm−2h−1bar−1), and the tensile strength increased from 7.2MPa to 8.4MPa at the expense of the fiber strain. The DOE analysis revealed that the stretching ratio positively affects the permeability and porosity but decreases the fiber strain. On the other hand, it was determined that the stretching temperature positively influences the permeability and fiber strength. The stretched membranes exceeded the PVDF performance upper bound prepared by the TIPS method. The membranes were primarily in the α-phase polymorph, and stretching the fibers up to 40% at 90°C did not induce any detectable β-phase crystals. The proposed preparation method offers a feasible and sustainable alternative to fabricate hollow fibers membranes with high tensile strength and high permeability.
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•Microporous PVDF membranes were prepared via TIPS using a green hydrophobic solvent.•A stretching step was applied using a Design of Experiment (DOE).•Stretched membranes showed strong tensile strength and permeability improvement.
Betulinic acid (BA) is a naturally arising pentacyclic triterpenoid that has anti-malarial, anti-retroviral, anti-inflammatory, and anti-cancer biological effects. More recently, it has been reported ...to possess anti-obesity activity mediated by the activation of AMP-activated protein kinase (AMPK). We further investigated antidiabetic activity of BA in mouse tissues at the cellular and systemic levels. We found that BA stimulated AMPK in a similar fashion to the known AMPK activators, such as 5-aminoimidazole-4-carboxamide-1-β-D-ribofuranoside and metformin. Notably, the level of glucose uptake by BA was not altered by wortmannin, suggesting that this activation did not depend on phosphoinositide 3-kinase. Furthermore, BA diminished blood glucose levels in alloxane-treated ICR mice and in untreated mice during the glucose tolerance test. BA also stimulated mRNA expression of glucose transporter 4, which could partly explain increased glucose uptake. BA also increased AS160 phosphorylation by insulin-independent mechanisms in the extensor digitorum longus muscle. These results indicate that BA may serve as a promising therapeutic agent for diabetes by activating AMPK, like metformin. Notably, BA also enhanced mouse endurance capacity, indicating that it also affects metabolic regulation in addition to its antidiabetic activity.
Sequence alterations in microsatellites and an elevated mutational burden are observed in 20% of gastric cancers and associated with clinical response to anti-PD-1 antibodies. However, 50% of ...microsatellite instability-high (MSI-H) cancers are intrinsically resistant to PD-1 therapies. We conducted a phase II trial of pembrolizumab in patients with advanced MSI-H gastric cancer and included serial and multi-region tissue samples in addition to serial peripheral blood analyses. The number of whole-exome sequencing (WES)-derived nonsynonymous mutations correlated with antitumor activity and prolonged progression-free survival (PFS). Coupling WES to single-cell RNA sequencing, we identified dynamic tumor evolution with greater on-treatment collapse of mutational architecture in responders. Diverse T-cell receptor repertoire was associated with longer PFS to pembrolizumab. In addition, an increase in PD-1
CD8
T cells correlated with durable clinical benefit. Our findings highlight the genomic, immunologic, and clinical outcome heterogeneity within MSI-H gastric cancer and may inform development of strategies to enhance responsiveness. SIGNIFICANCE: This study highlights response heterogeneity within MSI-H gastric cancer treated with pembrolizumab monotherapy and underscores the potential for extended baseline and early on-treatment biomarker analyses to identify responders. The observed markers of intrinsic resistance have implications for patient stratification to inform novel combinations among patients with intrinsically resistant features.
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