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Gain enhancement wideband CPW antenna based on artificial magnetic conductor
Abstract Unidirectional radiation and, hence, gain enhancement can be achieved by placing a primary radiator (simple antenna) at suitable height over a reflector to diminish back radiation and to enhance the forward radiation. The reflector used to enhance the gain is usually an electrically conducting surface (ECS) or an artificial magnetic conducting surface (AMCS). The ECS unifies the direction of radiation by reflecting the incident wave with $$180^\circ$$ phase shift, which requires the placement of the antenna at large enough height above the reflector to avoid destructive interference between the incident and the reflected waves. The AMCS is a metasurface constructed as periodic structure to produce reflection with 0° phase. This allows the antenna to be placed near the AMCS without destructive interference. Thus, the combined structure of the antenna and the AMCS reflector can have lower profile than that resulting in the case of employing ECS. The present work proposes a planar wideband antenna as well as an AMCS to produce unidirectional radiation with high gain over a wide frequency band. The proposed antenna is a planar octagon-shaped monopole patch with inverted U-slot and is fed through a coplanar waveguide (CPW). Both the radiating patch and the feeding line are printed on a single-sided substrate of type Rogers RT5880 of dimensions $$27\,\text{mm}\times 37\,\text{mm}$$ and thickness $$1.57\,\text{mm}$$ . The patch geometry is designed to maximize the radiation efficiency by cutting an inverted U-shaped slot with long base. The proposed AMCS consists of $$5\times 5$$ cells and has dimensions $$70\,\text{mm }\times 70\,\text{mm}$$ . The metallic patches of AMCS cells are printed on the top layer of a substrate of type Rogers’ RO4003C of thickness $$1.52\,\text{mm}$$ . Both the proposed antenna and AMCS are fabricated for experimental evaluation of the performance of the radiating structure. It is shown by simulation and measurement that the proposed antenna when based on the proposed AMCS produces a realized gain of $$11.5\,\text{dBi}$$ and total efficiency of greater than $$80\%$$ over the frequency band 3.5–6.5 GHz.
Transient colloidal crystals fueled by electrochemical reaction products
Detection of SARS-CoV-2 in bioaerosols and surface samples from healthcare facilities in Klang Valley, Malaysia
Neuron-specific isoform of PGC-1α regulates neuronal metabolism and brain aging
Abstract The brain is a high-energy tissue, and although aging is associated with dysfunctional inflammatory and neuron-specific functional pathways, a direct connection to metabolism is not established. Here, we show that isoforms of mitochondrial regulator PGC-1α are driven from distinct brain cell-type specific promotors, repressed with aging, and integral in coordinating metabolism and growth signaling. Transcriptional and proteomic profiles of cortex from male adult, middle age, and advanced age mice reveal an aging metabolic signature linked to PGC-1α. In primary culture, a neuron-exclusive promoter produces the functionally dominant isoform of PGC-1α. Using growth repression as a challenge, we find that PGC-1α is regulated downstream of GSK3β independently across promoters. Broad cellular metabolic consequences of growth inhibition observed in vitro are mirrored in vivo, including activation of PGC-1α directed programs and suppression of aging pathways. These data place PGC-1α centrally in a growth and metabolism network directly relevant to brain aging.
Atomization of Water Jet in Crossflow via High-Speed Photography
Abstract The interaction between crossflow and liquid jets is common in engineering applications, such as in gas–steam catapult power systems and supersonic ramjets. Studying the atomization process of liquid jets in crossflow has significant engineering value. In this work, high-speed photography was used. The experimental results indicate that factors such as airflow velocity, temperature, jet velocity, temperature, and nozzle diameter can affect the depth of jet penetration. Considering the influence of various factors, an empirical formula for calculating jet penetration is obtained. The results can support the design of gas–steam catapult propulsion systems and be extended to other applications, such as supersonic ramjets.
Author Correction: A nascent riboswitch helix orchestrates robust transcriptional regulation through signal integration
Comparative performance analysis of hemispherical solar stills using date and olive kernels as heat storage material
Abstract This study investigates the performance of hemispherical solar stills (HSS) enhanced with date kernels and olive kernels as heat storage materials to improve water distillation efficiency. By utilizing these natural and sustainable materials, the research highlights an alternative to synthetic options. Rigorous experimentation and detailed analysis under identical conditions reveal that both kernels significantly improve heat retention and water production rates. The HSS with date kernels (HSSDK) achieved a daily water productivity of 6.66 kg/m2 day, representing an efficiency increase of 10.87%, while the HSS with olive kernels (HSSOK) produced 8.00 kg/m2 day, enhancing efficiency by 13.54%. The cost per m3 of distilled water for HSSDK is approximately USD 4.65, while HSSOK costs USD 3.89, compared to USD 7.83 for the conventional CHSS system. These results demonstrate that the inclusion of heat storage materials has significantly reduced the cost of water production, with reductions of about 40% for HSSDK and 50% for HSSOK compared to the conventional system. These results are attributed to the high thermal conductivity and specific heat capacities of the kernels, enabling effective heat storage and gradual release. This study demonstrates the potential of agricultural by-products as cost-effective and sustainable solutions for solar water distillation. Further research is recommended to optimize the quantities and configurations of these materials, as well as to explore their integration with other renewable energy systems to enhance overall efficiency and sustainability.
Respiratory long COVID in aged hamsters features impaired lung function post-exercise with bronchiolization and fibrosis
Abstract Long-term consequences of SARS-CoV-2 infection affect millions of people and strain public health systems. The underlying pathomechanisms remain unclear, necessitating further research in appropriate animal models. This study aimed to characterize the trajectory of lung regeneration over 112 days in the male hamster model by combining morphological, transcriptomic and functional readouts. We demonstrate that in the acute phase, SARS-CoV-2 Delta-infected, male, aged hamsters show a severe impairment of lung function at rest. In the chronic phase, similar impairments persisted up to 7 weeks post-infection but were only evident after exercise on a rodent treadmill. The male hamster model recapitulates chronic pulmonary fibrotic changes observed in many patients with respiratory long COVID, but lacks extra-pulmonary long-term lesions. We show that sub-pleural and interstitial pulmonary fibrosis as well as alveolar bronchiolization persist until 112 dpi. Interestingly, CK8 + alveolar differentiation intermediate (ADI) cells are becoming less prominent in the alveolar proliferation areas from 28 dpi on. Instead, CK14 + airway basal cells and SCGB1A1 + club cells, expressing cell proliferation markers, mainly populate alveolar bronchiolization areas at later time-points. We postulate that pulmonary fibrosis and SCGB1A1 + club cell-rich areas of alveolar bronchiolization represent potential risk factors for other diseases in long-COVID survivors.
Multiparametric ultrasound (MPUS) evaluation of the testes of normozoospermic dogs – a pilot study
Transcriptional diversification in a human-adapting zoonotic pathogen drives niche-specific evolution
Abstract Bacterial pathogens can undergo striking adaptive evolutionary change in the context of infection, driven by selection forces associated with host defenses and antibiotic treatment. In this work, we analyze the transcriptional landscape associated with adaptation in an emerging zoonotic pathogen, Bordetella hinzii, as it evolved during a 45-month infection in an IL12Rβ1-deficient immunocompromised host. We find evidence of multiple niche-specific modifications in the intravascular and gastrointestinal compartments, involving the superoxide dismutase system, glutamate and ectoine metabolism, chaperone-mediated protein folding, pilus organization, and peptide transport. Individual blood lineages displayed modifications in glutathione, phenylacetate, and 3-phenylpropionate metabolism, iron cluster assembly, and electron transport, whereas individual gastrointestinal lineages demonstrated changes relating to gluconeogenesis, de novo pyrimidine synthesis, and transport of peptides and phosphate ions. Down regulation of the flagellar operon with corresponding loss of flagellar structures occurred in multiple lineages, suggesting an evolutionary tradeoff between motility and host immune evasion. Finally, methylome analysis demonstrates alteration of global genome methylation associated with loss of a Type III methyltransferase. Our findings reveal striking plasticity in how pathogen transcriptomes explore functional space as they evolve in the context of host infection, and demonstrate that such analysis may uncover phenotypic adaptations not apparent from genomic analysis alone.
Establishing metrics of clinically meaningful change for treating knee osteoarthritis with a combination of autologous orthobiologics
Observation of higher-order time-dislocation topological modes
Gestational hyperglycaemia impacts glucose control and insulin sensitivity in mouse offspring
Abstract Gestational diabetes mellitus (GDM) predisposes offspring to the development of obesity and type 2 diabetes. While GDM is studied in the context of maternal obesity and insulin resistance, the consequences of GDM in lean, insulin sensitive women for offspring health are unclear. This preclinical study investigated whether GDM in lean dams characterized by reduced insulin secretion affects offspring metabolic health. Lean GDM was induced by short-term 60% high-fat diet and low-dose streptozotocin injections before mating in mice. The control dams received only high-fat diet (HF) or low-fat diet (LF). Glucose homeostasis was studied in chow-fed offspring. GDM resulted in decreased birth weight, that resolved at postnatal day 15 (PN15). At PN100, higher postprandial glucose responses were found in GDM offspring, while insulin secretion was lower in both GDM and HF offspring. Female GDM offspring showed lower endogenous glucose production and increased liver insulin sensitivity at PN100 compared to controls. No differences in metabolic parameters were observed at PN200 and PN300. Prenatal exposure to elevated maternal glucose levels without maternal obesity modestly affected glucose regulation in mouse offspring during early adulthood. Future studies should clarify if a less favourable postnatal diet may further challenge metabolic health in offspring of GDM dams.
Improving adenine base editing precision by enlarging the recognition domain of CRISPR-Cas9
Theoretical analysis of dynamic sliding mechanism of rock slope with a bedding structural plane based on stress wave propagation
Abstract The stress at the structural plane of bedding rock slope will change under dynamic load, which may lead to sliding failure risk of the slope. Based on the time-domain recursive method (TDRM), the propagation process of stress waves in viscoelastic rock slope with a nonlinear bedding plane is analyzed, and the propagation equation of multiple reflected waves between the plane and the slope surface is obtained. According to the superposition principle and the relation between the particle vibration velocity caused by stress waves and stress, the expressions of normal and tangential stress of any particle at the structural plane are obtained. Furthermore, in light of the gravitational impact on the rock mass, we formulate the slip criterion equation for the structural plane. The results indicate that the stress field at the structural plane is influenced by several factors, including the slope angle, horizontal positioning of monitoring points, vertical distance to the slope foot, and the initial stiffness of the structural plane. The influence of multiple reflected waves on stress field obviously increases the possibility of rock mass sliding on structural plane. This paper theoretically elucidates the slippage mechanism of a rock slope featuring a bedding structural plane subjected to the effects of stress wave. The research findings furnish a theoretical foundation for comprehending the dynamic response of rock slopes, conducting dynamic stability analyses, and ensuring the safety measures for rock mass engineering projects.