Li Xin

• City University of Hong Kong

A high prevalence of low back disorders was observed among occupational drivers. A lot of investigations have shown associations between whole-body vibration and low back pain. However, few studies revealed the in vivo dynamic characteristics of the lumbar spine in both of the fore-and-aft and vertical directions. In this study, a whole-body finite...

When a high-speed aircraft flies through the atmosphere, the plasma sheath and plasma wake can significantly affect electromagnetic wave signals. To investigate the impact of the plasma sheath and wake on radar imaging, this paper first develops a linear frequency modulated continuous wave radar array signal echo model for the full target (body, pl...

CsPbBr3 perovskite solar cells (PSCs) have attracted significant interest for their remarkable stability under high temperatures and humidity. However, challenges such as energy loss at the CsPbBr3/oxide buried interface and imperfect band alignment have impeded further efficiency enhancements. In this study, TiO2, SnO2, or ZnO was employed as elec...

BACKGROUND Diabetic peripheral neuropathy (DPN) is a common complication of type 2 diabetes mellitus (T2DM), significantly affecting patients’ quality of life and imposing a substantial economic burden. Recent studies have highlighted the role of thyroid hormones in diabetes complications, particularly in elderly patients with T2DM. However, the re...

Background Sulfur microbial diet (SMD) is a dietary pattern closely related to the intestinal load of sulfur-metabolizing microbes in humans. Diet and microbes may play an important role in the carcinogenesis of esophagus. However, epidemiological studies on SMD and esophageal cancer (EC) risk are scarce. Here, we evaluated this association based o...

Accumulation of immune cells and proteins in the subarachnoid space (SAS) is found during multiple sclerosis and in the animal model experimental autoimmune encephalomyelitis (EAE). Whether the flow of cerebrospinal fluid (CSF) along the SAS of the spinal cord is impacted is yet unknown. Combining intravital near-infrared (NIR) imaging with histopa...

Background Lifelines Diet Score (LLDS) was developed based on the 2015 Dutch Dietary Guidelines and current international scientific evidence. As a dietary quality assessment tool, the LLDS aims to evaluate the association between the Lifeline diet and the risk of chronic diseases. However, the evidence linking LLDS to lung cancer risk is currently...

We aim to evaluate the efficacy and safety of pioglitazone/metformin fixed-dose combination (FDC) versus uptitrated metformin in patients with type 2 diabetes mellitus (T2DM) without adequate glycemic control. A total of 304 patients were recruited from 15 hospitals in China and randomly assigned (1:1) to the test group (pioglitazone/metformin FDC,...

Background Atraumatic subarachnoid haemorrhage (SAH) is associated with high morbidity and mortality. Proposed mechanisms for red blood cell (RBC) clearance from the subarachnoid space (SAS) are erythrolysis, erythrophagocytosis or through efflux along cerebrospinal fluid (CSF) drainage routes. We aimed to elucidate the mechanisms of RBC clearance...

The aim of this study was to quantitatively study the effect of anterior cervical discectomy and fusion (ACDF) on the risk of spinal injury under frontal impact. A head-neck finite element model incorporating active neck muscles and soft tissues was developed and validated. Based on the intact head-neck model, three ACDF models (single-level, two-l...

In this paper, a technology named SCM−ANN combining physical scattering mechanisms and artificial intelligence is proposed to realize radar cross-section (RCS) extrapolation of non-cooperative conductor targets with higher efficiency. Firstly, an adaptive scattering center (SC) extraction algorithm is used to construct the scattering center model (...

In this article, the small slope approximation in conjunction with the equivalent medium method is applied to analyze the acoustic scattering from a rough bubbly ocean surface, in which seawater with bubbles is regarded as a special medium, and the effect of subsurface bubbles is considered to have three main aspects: First, the attenuation effect,...

In this study, to accurately calculate the carbon footprint of silk products, key issues were analysed and discussed, including accounting boundary, accounting data, sequestration of greenhouse gases (GHG) and calculation of results. The results support the feasibility of "cradle to gate" or "gate to gate" as the accounting boundary for the carbon...

As an important part of textile production, the dyeing process not only makes the greatest contribution to water consumption and wastewater discharge, but its use of synthetic dyestuffs has a negative impact on all forms of life. To assess the environmental impact of textile production, it is necessary to assess the environmental impact of the dyei...

An improved shooting and bouncing ray (SBR) method based on the Blend-Tree structure is presented for solving the scattering from multiple complex movement targets. Since the positions and attitudes of targets change with time, the spatial distribution of facets is variable. Hence, quickly finding illuminated areas and tracing high-order rays are t...

Objective: Interspinous spacer (ISS)-based and pedicle screw-rod dynamic fixator (PDF)-based topping-off devices have been applied in lumbar/lumbosacral fusion surgeries for preventing the development of proximal adjacent segment degeneration. However, little attention has been paid to sacroiliac joint (SIJ), which belongs to the adjacent joints....

To solve the electromagnetic (EM) scattering from multiple identical rigid targets with traditional adaptive cross approximation method of moments (ACA-MoM), the multiple targets are treated as a single entity. ACA is introduced directly to the octree’s finest layer neglecting the characteristics of the targets. This leads to redundant storage of s...

BACKGROUND Maturity-onset diabetes of the young 10 caused by the c.4G>A (p.Ala2Thr) mutation is extremely rare, with only two reported studies to date. Herein, we report another case that differs from previous cases in phenotype. CASE SUMMARY The proband developed diabetes at the age of 27 years, despite having a normal body mass index (BMI). She...

Background Renal hemodynamic changes in early diabetes occur before the onset of significant structural abnormalities or clinical manifestations, and timely detection of these changes has clinical significance. This study aimed to evaluate renal elasticity and perfusion changes in an early-stage diabetic rat model by shear wave elastography (SWE) a...

Low back pain has been reported to have a high prevalence among occupational drivers. Whole-body vibration during the driving environment has been found to be a possible factor leading to low back pain. Vibration loads might lead to degeneration and herniation of the intervertebral disc, which would increase incidence of low back problems among dri...

Background: Lumbar/lumbosacral fusion supplemented with topping-off devices has been proposed with the aim of avoiding adjacent segment degeneration proximal to the fusion construct. However, it remains unclear how the biomechanics of the sacroiliac joint (SIJ) are altered after topping-off surgery. The objective of this study was to investigate t...

In this study, a composite scattering model of the vegetated ground with a target is developed. In the composite scattering model, a Facet-based Modified Two-scale Model (FMTSM), combining the advantages of Kirchhoff Approximate (KA) and Integral Equation Model (IEM), is established to calculate the electromagnetic (EM) scattering of the rough grou...

When a hypersonic vehicle flies in the atmosphere, plasma sheath and trails are configured around the vehicle due to aerodynamic heating and ablation, which distort the radar echo signal and then influence the target range information and Doppler frequency extracted from the echoes. In order to examine the impact of plasma laminar wake on radar det...

This study aimed to compare effect of whole-body vibration on biomechanics of fused lumbar spine with different posterior stabilizers, including interspinous process spacer (IPS) and bilateral pedicle screw system (BPSS). Finite element model of lumbar interbody fusion with IPS or BPSS at L4–L5 level was constructed based on a healthy human whole l...

Rigid interspinous process fixation (RIPF) has been recently discussed as an alternative to pedicle screw fixation (PSF) for reducing trauma in lumbar interbody fusion (LIF) surgery. This study aimed to investigate biomechanics of the lumbar spine with RIPF, and also to compare biomechanical differences between two postoperative stages (before and...

In this paper, a weighted arctangent function is used in conjunction with the spectral method to generate a land–sea junction composite rough surface under the spatially homogeneous and time-stationary hypotheses. The exponential correlation function and the Joint North Sea Wave Project (JONSWAP) spectrum, combined with an experiment-verified shoal...

Background: The prevalence of osteoporosis is continuing to escalate with an aging population. However, it remains unclear how biomechanical behavior of the lumbar spine is affected by osteoporosis under whole-body vibration, which is considered a significant risk factor for degenerative spinal disease and is typically present when driving a car....

The chemical release for trigging instabilities is a challenging topic in the ionosphere since 1970s. It is a helpful tool to both recognize the physical mechanism for modeling space weather and mitigate adverse effects on technological systems. Based on the well‐developed instability simulation, the rate of change of total electron content index (...

The signal source of synthetic aperture radar (SAR) usually adopts the linear frequency modulation (LFM) signal, which exhibits the characteristics of a wide pulse. Hence, in the case of usage of the LFM signal by time-domain shooting and bouncing ray (TDSBR) to simulate the SAR echo signal, numerous time sampling points are generated, resulting in...

In this paper, an adaptive TLS-ESPRIT algorithm based on analytical perspective is proposed to efficiently construct the scattering center mode and reconstruct the RCS of a PEC target. Compared with existing researches, the proposed method does not require knowing the number of scattering centers, which means that it can be applied to the construct...

For fast solving the electromagnetic scattering of multiple moving targets above or on a rough surface, the multi-dynamic-octrees-based SBR algorithm is proposed in the paper. Firstly, a local coordinate system (LCS) for each object is established that moves with targets in the geodetic coordinate system (GCS). The dynamic octree structure based on...

Low-density lipoprotein cholesterol (LDL-C) has been considered as the primary target for the prevention and treatment of atherosclerotic cardiovascular disease (ASCVD). However, there are still residual cardiovascular risks in some patients even if LDL-C achieves the target level. Emerging evidence suggestes that elevated triglyceride (TG) level o...

The accuracy and the efficiency of hybrid methods that combine geometrical optics (GO) and physical optics (PO), and physical theory of diffraction (PTD), have been improved by the use of backward-ray-tracing technique and Gordon’s integral algorithm. However, the overall accuracy of the method is still limited by the errors in the process of backw...

Background: The main purpose of this study was to examine the effect of different fixation methods (anterior fixation, self-stabilizing fixation and anterior-posterior fixation) on biomechanical property of vertebral body replacement and fusion. Methods: Three finite element models of cervical vertebral body replacement and fusion were establish...

Many previous studies have found that occupational drivers commonly suffered from low back pain, and low back pain and degeneration of the intervertebral disc might be associated with vibration conditions. However, the biomechanical mechanisms of whole-body vibration that caused pain and injury were not clear. In this study, a validated whole human...

This study aims to apply generative adversarial networks (GANs) to the effective classification of high/low resolution (HR/LR) image pairs obtained via inverse synthetic aperture radar (ISAR) for hypersonic objects covered with a plasma sheath. We propose a classification training model based on a Wasserstein GAN with a gradient penalty (U-WGAN-GP)...

Background: Exenatide is a glucagon-like peptide-1 receptor agonist that can reduce body weight. This study aimed to determine the efficacy of exenatide on body mass index (BMI) reduction in patients with type 2 diabetes mellitus (T2DM) with differing baseline body weight, blood glucose, and atherosclerotic status and to determine if there is a co...

In this paper, a compact 8 × 8 MIMO antenna design for 5G terminals is proposed. The 8 × 8 MIMO antenna consists of two quad-element antenna pairs, each of which includes two symmetrical T-shaped monopole mode elements and two symmetrical edge-coupled fed dipole mode elements. The size of the quad-element antenna is 38 × 7 × 0.8 mm3. T-shaped monop...

For reducing the adjacent segment degeneration of the lumbar spine, the interspinous process device as a kind of flexible non-fusion device was designed to overcome the deficiencies associated with rigid fusion devices. However, it was not clear how the interspinous process device influenced the human spine system, especially the lumbar spine under...

This letter proposes an improved shooting and bouncing ray (SBR) method to efficiently predict the radar cross (RCS) of electrically large targets. First, the scan line algorithm is used to convert three-dimensional (3-D) processing to the 2-D graphic display, which expedites the elimination of shadows. Then, the ray tracing process is accelerated...

A longitudinally miniaturized H-plane horn antenna with suppressed sidelobes by redistributing the field on the radiating aperture is proposed by loading a few rectangular blocks. The substantial longitudinal length reduction (around 50% of an optimal horn) will cause a nonuniform phase and nontapering magnitude distributions of the electric fields...

This study aimed to investigate and compare the effects of two widely used nonfusion posterior dynamic stabilization (NPDS) devices, pedicle screw‐based dynamic stabilizer (PSDS) and interspinous process spacer (IPS), on biomechanics of the implanted lumbar spine under static and vibration loadings. The finite element model of healthy human lumbosa...

In this paper, the strip synthetic aperture radar (SAR) image of a composite vehicle–ground model is simulated by combining the electromagnetic scattering algorithm and radar imaging algorithm. A linear frequency modulated wave is incident on the composite model, which is partitioned into a mass of triangular patches. In the “stop-and-go” radar mod...

Under whole body vibration, how the cement augmentation affects the vibration characteristic of the osteoporotic fusion lumbar spine, complications, and fusion outcomes is unclear. A L1-L5 lumbar spine finite element model was developed to simulate a transforaminal lumbar interbody fusion (TLIF) model with bilateral pedicle screws at L4-L5 level, a...

Calibration isan important step in measuring the electromagnetic scattering from a target. Metal spheres are usually selected as calibrators in the calibration process. However, real spherical calibrators are not perfect spheres, which cause calibration errors due to their geometric irregularity and thus affect the radar cross section (RCS) predict...

When electromagnetic (EM) coupling exists, false peaks occur periodically in high-resolution range profile (HRRP). These false peaks restrict the improvement of the success rate of the target recognition based on HRRPs. Therefore, identifying these false peaks and removing them is crucial, but has not been thoroughly investigated in the open litera...

Traditional radar-cross-section (RCS) estimation of a target using a near-field sampling scheme usually needs to probe the scattering electric fields on a spherical surface or a plane, which is time consuming. To improve the testing efficiency, a novel lineal sampling method is proposed in this letter. This method can significantly reduce the amoun...

Objective Investigations showed that low back pain of occupational drivers might be closely related to the whole-body vibration. Restricted by ethical concerns, the finite element method had become a viable alternative to invasive human experiments. Many mechanical behaviours of the human spine inside of human body were unclear, therefore, a human...

The propagation of electromagnetic waves in the troposphere is significantly influenced by atmospheric refractivity and atmospheric ducts. Thus, abundant statistics on atmospheric refractivity and ducts are essential for reliable propagation prediction. In this study, we develop novel digital maps of atmospheric refractivity and atmospheric ducts b...

This paper proposes a shooting and bouncing ray (SBR) method based on a dynamic octree structure to accelerate the solution of scattering from a moving target. In this algorithm, three coordinate systems are established: the world coordinate system (WCS), the local coordinate system (LCS), and the perspective projection coordinate system (PPCS). Fi...

The anatomical routes for the clearance of cerebrospinal fluid (CSF) remain incompletely understood. However, recent evidence has given strong support for routes leading to lymphatic vessels. A current debate centers upon the routes through which CSF can access lymphatics, with evidence emerging for either direct routes to meningeal lymphatics or a...

An improved shooting and bouncing rays and two-scale method (SBR-TSM) based on Message Passing Interface (MPI) is developed to analyze the composite electromagnetic (EM) scattering from multiple targets above a rough sea surface in this paper. The TSM is used to calculate the scattering of the rough sea surface, and the improved SBR method is used...

In this letter, a novel double-layer transmitarray element is proposed. Different from the traditional transmitarray element design, the proposed double-layer element uses a specially designed substrate. The combined substrate is composed of two horizontally arranged different dielectric materials. By etching metal double square loops on this combi...

A compact single-layer filtering patch antenna with wide harmonic suppression and enhanced bandwidth is proposed. The filtering antenna is derived from the conventional square patch antenna. To effectively eliminate harmonics and create an upper radiation null, two wide slots are etched on the patch. A shorting via is inserted near the central area...

Chaff cloud is a passive jammer that is widely used in many tactical applications. It contains huge numbers of metallic fibers to produce a strong echo. However, electromagnetic (EM) scattering estimation for the chaff cloud is a challenging task, since complex EM coupling between chaff elements needs to be taken into account. Actually, if the dist...

This article presents an ultracompact bandpass filter (BPF) realized by slow wave substrate integrated groove gap waveguide (SW-SIGGW). The SW-SIGGW is composed of two layers of the dielectric substrate, in which periodic mushroom-type electromagnetic band-gap (EBG) unit cells are employed as packaging structures. The gap layer is realized by the u...

Effects of nonuniform weakly ionized dusty plasma on the polarization properties of obliquely incident electromagnetic (EM) waves were theoretically investigated in this paper. The dielectric coefficient of magnetized dusty plasma is obtained based on the Bhatnagar–Gross–Krook collision model. Then, the effects of external magnetic field, dust radi...

Topping-off technique has been proposed to prevent adjacent-segment degeneration/disease following spine fusion surgery. Nevertheless, few studies have investigated biomechanics of the fusion surgery with topping-off device under whole-body vibration (WBV). This biomechanical study aimed to investigate the vibration characteristics of human lumbar...

Objectives This study investigated the clinical efficacy and safety of metformin hydrochloride sustained-release (SR) tablet (II) produced by Dulening and the original metformin hydrochloride tablet produced by Glucophage in the treatment of type 2 diabetes mellitus (T2DM). Methods This randomized, open and parallel controlled clinical trial conse...

To simplify the design of a beam scanning device, we present a simple and compact structure to realize the frequency scanning characteristic based on a hybrid waveguide consisting of a spoof surface plasmon polariton (SSPP) transmission line and half-mode substrate integrated waveguide (HMSIW). Additionally, the radiation characteristic is implemen...

Although the contributions of sitagliptin to endothelial dysfunction in diabetes mellitus were previously reported, the mechanisms still undefined. Autophagy plays an important role in the development of diabetes mellitus, but its role in diabetic macrovascular complications is unclear. This study aims to observe the effect of sitagliptin on macrov...

This work investigates the intrinsic degradation mechanism of InGaN/GaN UVA (320–400 nm) light emitting diodes (LEDs) after swift heavy ion irradiation from the defect aspect using temperature-dependent low frequency noise measurement. The UVA LEDs were exposed to 1423 MeV Ta ions with a fluence of 10⁸–10¹⁰ ions cm⁻². The optical power decreases an...

Purpose Biomechanical comparison between rigid and non-rigid posterior stabilization systems following lumbar interbody fusion has been conducted in several studies. However, most of these previous studies mainly focused on investigating biomechanics of adjacent spinal segments or spine stability. The objective of the present study was to compare b...

An inverse synthetic aperture radar (ISAR) imaging framework is proposed to process transient scattered echoes into ISAR images. First, the time-domain shooting and bouncing ray (TDSBR) method is developed to simulate the transient scattering echoes. Then based on the electromagnetic scattering echo expressions, the ISAR imaging formula is derived....

A wideband single-layer substrate integrated waveguide (SIW) filtering slot antenna with compact structure is investigated, which is originated from a SIW resonant cavity operating at its TE <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">110</sub> mode. A straight radiating slot is integrated on the t...

Background: In order to alleviate muscle fatigue and improve ride comfort, many published studies aimed to improve the seat environment or optimize seating posture. However, the effect of lumbar support on the lumbar muscle of seated subjects under whole body vibration is still unclear. Objective: This study aimed to investigate the effect of lu...

The calibration process is an essential kernel step in far-field radar cross section measurement. Nevertheless, in the turntable test scenario, the calibrator cannot always be placed at the rotation center of the turntable. Because the geometric center and the rotation center of the upper surface of the turntable are not always coincident. To addre...

A new electromagnetic band gap (EBG) structure based on the soft and hard surfaces for gap waveguide (GW) technology is introduced in this article. The proposed EBG structure consists of a soft surface and a hard surface in parallel with a gap between them, where the ridges/corrugations of the two surfaces are perpendicular to each other or with an...

Lumbar fixator has been widely used, which can stabilize the lumbar spine and improve the fusion outcomes, but also lead to many complications. The effects of the internal fixator on biomechanical properties of the fused lumbar spine have been widely concerned for many years. However, most studies only considered the static loads and did not consid...

Nucleotomy is a common surgical procedure for the treatment of lumbar diseases. It may accelerate degeneration in the operated disc and decreased segmental stability, and this has been widely concerned by scholars for many years. However, under whole-body vibration, nucleotomy how to affect the vibration characteristics of the lumbar spine and comp...

Background: Several finite element (FE) models have been developed to study the effects of vibration on human lumbar spine. However, the authors know of no published results so far that have proposed computed tomography-based FE models of whole lumbar spine including the pelvis to conduct dynamic analysis. Objective: To create and validate a thr...