Picosecond laser-driven coded-source radiography with high resolution and contrast.

The X-ray sources for Compton radiography of ICF experiments are generated by using intense picosecond lasers to irradiate wire targets. The wire diameter must be designed thin enough, for example ∼ 10 µm in many published works, to comply a high spatial resolution. This results in a low laser-target interception, which limits the photon yield. We investigated a technique of coded-source radiography based on laser-driven annular sources via Monte Carlo and PIC simulations. The annular X-ray source is formed by laser irradiating tube target in which the effect of electron recirculation plays an important role. We proved that this technique has an increased spatial resolution and contrast than that using the Gaussian source produced by wire targets. Therefore, the diameter of the backlighter target can be significantly increased to uplift laser-target interception without compromising on spatial resolution. This contributes towards a reconciliation between the spatial resolution and photon yield for Compton radiography. The results predict the possibility of improving source photon yield by several times in future experiments.

Laser-driven electron emission and expansion for the generation and guidance of giant EMPs.

High-power laser interacting with matter generates intense electromagnetic pulses (EMPs), which are closely associated with laser and target parameters. In this study, EMPs induced by picosecond (ps) laser coupling with solid targets are recorded at the XG-III laser facility. Gold wire targets produce more intense EMPs with a maximum EMP value of 608 kV/m compared to some planar targets. EMP propagation in the normal direction is highly coincident with the expansion of detected hot electrons, which is verified by the particle-in-cell simulations. This work is expected to pave, to our knowledge, a new avenue for directional guidance of laser-driven EMPs.

Associations between temporal eating patterns and body composition in young adults: a cross-sectional study.

PURPOSE: The aim of this study was to examine the associations between body composition and temporal eating patterns, including time of first eating occasion, time of last eating occasion, eating window, and eating jet lag (the variability in meal timing between weekdays and weekends). METHODS: A total of 131 participants were included in the study. Temporal eating pattern information was collected through consecutive 7-day eat timing questionnaires and photographic food records. Body composition was assessed by bioelectrical impedance analysis. Multiple linear regression models were used to evaluate the relationships of temporal eating patterns with body composition, and age was adjusted. Eating midpoint was additionally adjusted in the analysis of eating window. RESULTS: On weekdays, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with lower body fat percentage. On weekends, both later first eating occasion and last eating occasion were associated with lower lean mass, and longer eating window was associated with higher FFMI. Longer first eating occasion jet lag was associated with lower lean mass. CONCLUSION: Our study suggested that earlier and more regular eating patterns may have a benefit on body composition.

Current status and development trends in CKD with frailty research from 2000 to 2021: a bibliometric analysis.

INTRODUCTION: The prevalence of chronic kidney disease (CKD) is gradually increasing in the elderly population. At the same time, frailty has become one of the research hotspots in the field of geriatrics. Bibliometric analyses help to understand the direction of a field. Therefore, this study aimed to analyze the status and emerging trends of frailty in CKD patients. DATA AND METHODS: The Web of Science Core Collection (WoSCC) database was screened for relevant literature published between 1 January 2000 and 31 December 2021. Next, publications were analyzed for information including authors, journals, cited references, citing journals, institutions, countries and regions, high-frequency keywords and co-citations using VOSviewer, Microsoft Excel, and R software. RESULTS: A total of 2223 articles were obtained, from which 613 relevant articles were selected based on title and abstract screening. There was an upward trend in the number of annual publications and Johansen KL was considered the most contributing author in the field. The Clinical Journal of the American Society of Nephrology was the most productive research journal. Johns Hopkins University is the most published organization. The United States is the global leader in the field and contributes the most to research. Research hotspots focus on epidemiological studies of frailty and frailty intervention. CONCLUSIONS: This study presents a comprehensive bibliometric analysis of CKD and frailty research. Key findings highlight the current focus on early screening and assessment of frailty in CKD patients, as well as physical function interventions in frail patients.

Development of Wearable Devices for Collecting Digital Rehabilitation/Fitness Data from Lower Limbs.

Lower extremity exercises are considered a standard and necessary treatment for rehabilitation and a well-rounded fitness routine, which builds strength, flexibility, and balance. The efficacy of rehabilitation programs hinges on meticulous monitoring of both adherence to home exercise routines and the quality of performance. However, in a home environment, patients often tend to inaccurately report the number of exercises performed and overlook the correctness of their rehabilitation motions, lacking quantifiable and systematic standards, thus impeding the recovery process. To address these challenges, there is a crucial need for a lightweight, unbiased, cost-effective, and objective wearable motion capture (Mocap) system designed for monitoring and evaluating home-based rehabilitation/fitness programs. This paper focuses on the development of such a system to gather exercise data into usable metrics. Five radio frequency (RF) inertial measurement unit (IMU) devices (RF-IMUs) were developed and strategically placed on calves, thighs, and abdomens. A two-layer long short-term memory (LSTM) model was used for fitness activity recognition (FAR) with an average accuracy of 97.4%. An intelligent smartphone algorithm was developed to track motion, recognize activity, and calculate key exercise variables in real time for squat, high knees, and lunge exercises. Additionally, a 3D avatar on the smartphone App allows users to observe and track their progress in real time or by replaying their exercise motions. A dynamic time warping (DTW) algorithm was also integrated into the system for scoring the similarity in two motions. The system's adaptability shows promise for applications in medical rehabilitation and sports.

Design of an off-axis axiparabola with inclined wavefront correction to obtain a straight focal line.

The axiparabola is a novel reflective element proposed in recent years, which can generate a long focal line with high peak intensity, and has important applications in laser plasma accelerators. The off-axis design of an axiparabola has the advantage of separating the focus from incident rays. However, an off-axis axiparabola designed by the current method always produces a curved focal line. In this paper, we propose a new method to design its surface by combining geometric optics design and diffraction optics correction, which can effectively convert a curved focal line into a straight foal line. We reveal that the geometric optics design inevitably introduces an inclined wavefront, which leads to the bending of the focal line. To compensate for the tilt wavefront, we use an annealing algorithm to further correct the surface through diffraction integral operation. We also carry out numerical simulation verification based on scalar diffraction theory, which proves that the surface of this off-axis mirror designed by this method can always obtain a straight focal line. This new method has wide applicability in an axiparabola with any off-axis angle.

Target Density Effects on Charge Transfer of Laser-Accelerated Carbon Ions in Dense Plasma.

We report on charge state measurements of laser-accelerated carbon ions in the energy range of several MeV penetrating a dense partially ionized plasma. The plasma was generated by irradiation of a foam target with laser-induced hohlraum radiation in the soft x-ray regime. We use the tricellulose acetate (C_{9}H_{16}O_{8}) foam of 2 mg/cm^{3} density and 1 mm interaction length as target material. This kind of plasma is advantageous for high-precision measurements, due to good uniformity and long lifetime compared to the ion pulse length and the interaction duration. We diagnose the plasma parameters to be T_{e}=17 eV and n_{e}=4×10^{20} cm^{-3}. We observe the average charge states passing through the plasma to be higher than those predicted by the commonly used semiempirical formula. Through solving the rate equations, we attribute the enhancement to the target density effects, which will increase the ionization rates on one hand and reduce the electron capture rates on the other hand. The underlying physics is actually the balancing of the lifetime of excited states versus the collisional frequency. In previous measurement with partially ionized plasma from gas discharge and z pinch to laser direct irradiation, no target density effects were ever demonstrated. For the first time, we are able to experimentally prove that target density effects start to play a significant role in plasma near the critical density of Nd-glass laser radiation. The finding is important for heavy ion beam driven high-energy-density physics and fast ignitions. The method provides a new approach to precisely address the beam-plasma interaction issues with high-intensity short-pulse lasers in dense plasma regimes.

Identification of discriminative neuroimaging markers for patients on hemodialysis with insomnia: a fractional amplitude of low frequency fluctuation-based machine learning analysis.

BACKGROUND AND OBJECTIVE: Insomnia is one of the common problems encountered in the hemodialysis (HD) population, but the mechanisms remain unclear. we aimed to (1) detect the spontaneous brain activity pattern in HD patients with insomnia (HDWI) by using fractional fractional amplitude of low frequency fluctuation (fALFF) method and (2) further identify brain regions showing altered fALFF as neural markers to discriminate HDWI patients from those on hemodialysis but without insomnia (HDWoI) and healthy controls (HCs). METHOD: We compared fALFF differences among HDWI subjects (28), HDWoI subjects (28) and HCs (28), and extracted altered fALFF features for the subsequent discriminative analysis. Then, we constructed a support vector machine (SVM) classifier to identify distinct neuroimaging markers for HDWI. RESULTS: Compared with HCs, both HDWI and HDWoI patients exhibited significantly decreased fALFF in the bilateral calcarine (CAL), right middle occipital gyrus (MOG), left precentral gyrus (PreCG), bilateral postcentral gyrus (PoCG) and bilateral temporal middle gyrus (TMG), whereas increased fALFF in the bilateral cerebellum and right insula. Conversely, increased fALFF in the bilateral CAL/right MOG and decreased fALFF in the right cerebellum was observed in HDWI patients when compared with HDWoI patients. Moreover, the SVM classification achieved a good performance [accuracy = 82.14%, area under the curve (AUC) = 0.8202], and the consensus brain regions with the highest contributions to classification were located in the right MOG and right cerebellum. CONCLUSION: Our result highlights that HDWI patients had abnormal neural activities in the right MOG and right cerebellum, which might be potential neural markers for distinguishing HDWI patients from non-insomniacs, providing further support for the pathological mechanism of HDWI.

Association between nut consumption and frailty in the elderly: a large sample cross-sectional study.

BACKGROUND: Limited literature has addressed the impact of nut consumption in mitigating frailty. This study aimed to investigate the association between nut consumption and frailty among Americans aged above 60 years, employing two 24-h dietary recalls for analysis. METHODS: The data sets of the National Health and Nutrition Examination Survey (NHANES) (2003-2018) and the Food Patterns Equivalents Database were utilised for a weighted multiple logistic regression model to evaluate the association between nut consumption and frailty in elderly adults. Furthermore, a restricted cubic spline model was employed to investigate the nonlinear relationship between nut intake and frailty. Besides, stratified and interaction analyses were conducted to explore the sensitivity of nut consumption in reducing the risk of frailty in diverse subgroups. RESULTS: The research study comprised 10,033 individuals aged 60 years or above, of whom 3591 were classified as frailty and 5302 consumed nuts. In the multivariate logistic regression analysis that adjusted for covariates, the weighted multivariate adjusted odds ratios demonstrated that the prevalence of frailty was lower in the nut intake group than in nonconsumers. The stratified analysis indicated that nearly all subgroups who consumed nuts had a significantly lower risk of frailty compared to nonconsumers, and an interaction was observed between nut intake and nonhypertensive populations. The optimal threshold for nut intake to decrease the risk of frailty was identified as 1.02 ounces. CONCLUSIONS: The study concluded that nut consumption has a constructive impact on averting frailty in elderly adults, particularly in nonhypertensive individuals. Nut intake of ~1.02 ounces per day is advantageous in improving the quality of life in elderly adults.

Bluetooth-Based Healthcare Information and Medical Resource Management System.

This paper presents a healthcare information and medical resource management platform utilizing wearable devices, physiological sensors, and an indoor positioning system (IPS). This platform provides medical healthcare information management based on the physiological information collected by wearable devices and Bluetooth data collectors. The Internet of Things (IoT) is constructed for this medical care purpose. The collected data are classified and used to monitor the status of patients in real time with a Secure MQTT mechanism. The measured physiological signals are also used for developing an IPS. When the patient is out of the safety zone, the IPS will send an alert message instantly by pushing the server to remind the caretaker, easing the caretaker's burden and offering extra protection for the patient. The presented system also provides medical resource management with the help of IPS. The medical equipment and devices can be tracked by IPS to tackle some equipment rental problems, such as lost and found. A platform for the medical staff work coordination information exchange and transmission is also developed to expedite the maintenance of medical equipment, providing the shared medical information to healthcare and management staff in a timely and transparent manner. The presented system in this paper will finally reduce the loading of medical staff during the COVID-19 pandemic period.