Feasibility of I groundwater dating calibrated by both Kr and He for the assessment of deep geological repositories in Japan.

Iodine-129, which is a promising tracer for dating old groundwater, has been used as a tracer for deep upwelling groundwater. The nuclide is expected to be one of the key factors for site selection for high-level radioactive waste disposal, which is a global societal issue. The pre-anthropogenic I/I ratio for marine iodine is (1.

Dual-band frequency reconfigurable metasurface antenna for millimeter wave joint communication and radar sensing systems.

This paper introduces an innovative, compact, and high-gain metasurface antenna, covering both the 24 GHz millimeter wave (mmWave) radar band and the 5 G n257 and n258 bands. The proposed metasurface antenna consists of a wideband stacked patch antenna and a dual-layer metasurface to focus its radiation beams for multiple mmWave bands. The operating frequency can be slightly shifted by altering the distance between the feeder and the metasurface.

A Kr*-Rb cold collision apparatus based on atom trap.

A cold collision between atoms and molecules (<1 K) is one of the hot research fields in atomic and molecular physics. At low temperatures, the number of partial waves participating in the collision process decreases dramatically, and quantum phenomena start to emerge. The reaction is often dominated by quantum tunneling, and pronounced resonances can exist on collision cross sections.

Structures of the human Wilson disease copper transporter ATP7B.

The P-type ATPase ATP7B exports cytosolic copper and plays an essential role in the regulation of cellular copper homeostasis. Mutants of ATP7B cause Wilson disease (WD), an autosomal recessive disorder of copper metabolism. Here, we present cryoelectron microscopy (cryo-EM) structures of human ATP7B in the E1 state in the apo, the putative copper-bound, and the putative cisplatin-bound forms.

A magnetically enhanced RF discharge source for metastable krypton production.

We describe a high intensity metastable Kr source based on a helical resonator RF discharge. By adding an external B-field to the discharge source, the metastable Kr flux is enhanced. The effect of geometric configuration and magnetic field strength has been studied and optimized experimentally.

A Tibetan ice core covering the past 1,300 years radiometrically dated with Ar.

Ice cores from alpine glaciers are unique archives of past global and regional climate conditions. However, recovering climate records from these ice cores is often hindered by the lack of a reliable chronology, especially in the age range of 100 to 500 anni (a) for which radiometric dating has not been available so far. We report on radiometric Ar dating of an ice core from the Tibetan Plateau and the construction of a chronology covering the past 1,300 a using the obtained Ar ages.

Recent Progress in Reconfigurable and Intelligent Metasurfaces: A Comprehensive Review of Tuning Mechanisms, Hardware Designs, and Applications.

Intelligent metasurfaces have gained significant importance in recent years due to their ability to dynamically manipulate electromagnetic (EM) waves. Their multifunctional characteristics, realized by incorporating active elements into the metasurface designs, have huge potential in numerous novel devices and exciting applications. In this article, recent progress in the field of intelligent metasurfaces are reviewed, focusing particularly on tuning mechanisms, hardware designs, and applications.

Serum Neurofilament Light Chain in Wilson's Disease: A Promising Indicator but Unparallel to Real-Time Treatment Response.

Background: Wilson's disease (WD) currently lacks a promising indicator that could reflect neurological impairment and monitor treatment outcome. We aimed to investigate whether serum neurofilament light chain (sNfL) functions as a candidate for disease assessment and treatment monitoring of WD.

Methods: We assessed preclinical and manifested WD patients' sNfL levels compared to controls and analyzed the differences between patients with various clinical symptoms.

Fast atom-trap analysis of Ar with isotope pre-enrichment.

We demonstrate fast analysis of Ar/Ar at the 10 level using a mass spectrometer for isotope pre-enrichment and an atom trap for counting. An argon gas sample first passes through a dipole mass separator that reduces the dominant isotope Ar by two orders of magnitude while preserving both the rare tracer isotope Ar and a minor stable isotope Ar for control purposes. Measurements of both natural and enriched samples with atom trap trace analysis demonstrate that the Ar/Ar ratios change less than 10%, while the overall count rates of Ar are increased by one order of magnitude.

Time-coding spread-spectrum reconfigurable intelligent surface for secure wireless communication: theory and experiment.

We present a time-coding reconfigurable intelligent surface (RIS) enabled spread-spectrum secure wireless communication system. The time-coding spread-spectrum RIS is realized by altering the RIS between the two states of a perfect electrical conductor (PEC) and perfect magnetic conductor (PMC), according to a pseudo-random time sequence, respectively. This spectrum spreading function of the time-coding RIS can be simply applied to the secure wireless communication systems, providing a low-cost, easy-implementation encrypting architecture with the two key features of interception prevention and interference suppression.

Linear-polarization metasurface converter with an arbitrary polarization rotating angle.

This paper presents a new design of linear-polarization metasurface converter with arbitrary polarization rotating angle. The linear-polarization conversion is achieved by first separating the linearly polarized incident wave into two orthogonal circularly polarized waves, then adding an additional phase to one of the circularly polarized waves, and finally recombining these two circularly polarized waves into a linearly polarized wave and reflecting it towards free space. A practical unit cell operating at 10 GHz with sandwich structure is applied to realize the linear-polarization metasurface converter, which consists of a top-layer square patch, a middle-layer ground plane, a bottom-layer 90° quadrature hybrid coupler, and two vias connecting the top layer and bottom layer.

An atom trap system for Ar dating with improved precision.

Cosmogenic Ar dating is an emerging technique in dating mountain glacier ice, mapping ocean circulation, and tracing groundwater flow. We have realized an atom-trap system for the analysis of the radioactive isotope Ar (half-life = 269 years) in environmental samples. The system is capable of analyzing small (1-5 kg) environmental water or ice samples and achieves a count rate of 10 atoms/h for Ar at the modern isotopic abundance level of 8 × 10.

Monitoring atmospheric Kr by atom counting.

Radioactive Kr is a major gaseous fission product emitted into the air by the nuclear fuel reprocessing industry. Measuring atmospheric Kr has applications in environmental monitoring, atmospheric transport model validation and dating of environmental water samples, including groundwater, sea water and glacier ice. We present an ultra-sensitive method for fast analysis of atmospheric Kr at 10 parts per trillion level.

Dual-band multi-bit programmable reflective metasurface unit cell: design and experiment.

Programmable reflective metasurfaces that combine the features of reconfigurable phased array antennas and reflectors are an effective solution for radar and modern communication systems. However, most of the demonstrated active metasurfaces support tunable responses for a specific frequency band. Thus, we propose a programmable metasurface that combines the advantages of multi-bit phase quantization and dual-band operations.

Electronically reconfigurable unit cell for transmit-reflect-arrays in the X-band.

This paper proposes an electronically reconfigurable unit cell for transmit-reflect-arrays in the X-band, which makes it possible to control the reflection or transmission phase independently by combining the mechanisms of reconfigurable transmitarrays and reconfigurable reflectarrays. The fabricated unit cell was characterized in a waveguide simulator. The return loss in the reflection mode and insertion loss in the transmission mode are smaller than 1.

Prevalent Pathogenic Variants of in Chinese Patients with Wilson's Disease: Geographical Distribution and Founder Effect.

Wilson's disease (WD) is an autosomal recessive disorder caused by pathogenic variants. This study aimed to show the geographical distribution and haplotype spectrum of three prevalent pathogenic variants (p.R778L, p.

Role for Biochemical Assays and Kayser-Fleischer Rings in Diagnosis of Wilson's Disease.

Background & Aims: Wilson disease is an autosomal recessive disorder that impairs copper homeostasis and is caused by homozygous or compound heterozygous mutations in ATP7B, which encodes a copper-transporting P-type ATPase. Patients have variable clinical manifestations and laboratory test results, resulting in diagnostic dilemmas. We aimed to identify factors associated with symptoms and features of Wilson disease from a large cohort, over 15 years.

Clinical features and outcome of Wilson's disease with generalized epilepsy in Chinese patients.

Objective: Generalized epilepsy is rarely reported in patients with Wilson disease (WD) and lacks experience in clinical practice. We aim to provide better experience for the diagnosis and treatment for WD patients with epilepsy in the future.

Methods: A retrospective study was performed in 13 Chinese WD patients with generalized epilepsy.

Multi-bit dielectric coding metasurface for EM wave manipulation and anomalous reflection.

In this paper, a multi-bit dielectric reflective metasurface is presented for control of electromagnetic (EM) wave scattering and anomalous reflection. The unit cell is designed to act as a 1-, 2-, and 3-bit coding metasurface to attain better control of EM waves. For the 3-bit coding metasurface, the eight digital states have phase responses of 0°, 45°, 90°, 135°, 180°, 225°, 270°, and 315°.

Generation of wideband vortex beam with different OAM modes using third-order meta-frequency selective surface.

Orbital angular momentum (OAM) beam generators have attracted tremendous interests recently due to their excellent performance and potential applications in wireless communication. However, the existing transmissive OAM generators suffer from several limitations, such as narrow bandwidth, high profile and low efficiency. In this study, a new wideband third-order meta-frequency selective surface (meta-FSS) for generating focusing vortex beam is developed.

Dual Separation of Krypton and Argon from Environmental Samples for Radioisotope Dating.

The noble gas radioisotopes Kr, Kr, and Ar are nearly ideal environmental tracers because of their chemical inertness and simple transport mechanisms. Recent advances in Atom Trap Trace Analysis have enabled measurements of Kr and Kr using 10-20 kg of water or ice, and Ar in only a few kilograms, making these tracers available to be applied in the earth sciences on a large-scale. To meet the resulting increase in demand, we have developed an automated process for the dual separation of krypton and argon from environmental samples based on titanium gettering and gas chromatography.

Analysis of krypton-85 and krypton-81 in a few liters of air.

Long-lived radioactive krypton isotopes, (81)Kr (t1/2 = 229,000 year) and (85)Kr (t1/2 = 10.76 year), are ideal tracers. (81)Kr is cosmogenic and can be used for dating groundwater beyond the (14)C age.

Krypton-81 in groundwater of the Culebra Dolomite near the Waste Isolation Pilot Plant, New Mexico.

The Waste Isolation Pilot Plant (WIPP) in New Mexico is the first geologic repository for disposal of transuranic nuclear waste from defense-related programs of the US Department of Energy. It is constructed within halite beds of the Permian-age Salado Formation. The Culebra Dolomite, confined within Rustler Formation evaporites overlying the Salado Formation, is a potential pathway for radionuclide transport from the repository to the accessible environment in the human-disturbed repository scenario.