Unveiling attenuation structures in the northern Taiwan volcanic zone.

This cutting-edge study delves into regional magmatism in northern Taiwan through advanced 3-D P- and S-wave frequency-dependent attenuation tomography. Positioned at the dynamic convergence boundary between the Philippine Sea Plate and the Eurasian Plate, Taiwan experiences moderate earthquakes and intriguing volcanic activity, with a focus on the Tatun volcano group. Employing the Formosa seismic array for high-resolution results, our research identifies high-attenuation anomalies (low Q) beneath the northern Taiwan volcanic zone (NTVZ) and offshore submarine volcanoes, indicative of potential hydrothermal activities and magma reservoirs at varying depths. Additionally, we explore low-attenuation anomalies (high Q) in the forearc region of the Ryukyu subduction zone, suggestive of partial saturation linked to serpentinization processes resulting from seawater infiltration or forearc mantle hydration. These findings shed light on the complex geological features and provide essential insights into the crustal properties of northern Taiwan, contributing to a deeper understanding of its magmatic evolution and tectonic processes.

Multicolor Emission from Ultraviolet GaN-Based Photonic Quasicrystal Nanopyramid Structure with Semipolar InxGa1-xN/GaN Multiple Quantum Wells.

In this study, we demonstrated large-area high-quality multi-color emission from the 12-fold symmetric GaN photonic quasicrystal nanorod device which was fabricated using the nanoimprint lithography technology and multiple quantum wells regrowth procedure. High-efficiency blue and green color emission wavelengths of 460 and 520 nm from the regrown InxGa1-xN/GaN multiple quantum wells were observed under optical pumping conditions. To confirm the strong coupling between the quantum well emissions and the photonic crystal band-edge resonant modes, the finite-element method was applied to perform a simulation of the 12-fold symmetry photonic quasicrystal lattices.

Unveiling Tatun volcanic plumbing structure induced by post-collisional extension of Taiwan mountain belt.

The Tatun Volcanic Group (TVG) is proximal to the metropolis of Taipei City (population of ca. 7 million) and has long been a major concern due to the potential risks from volcanic activity to the population and critical infrastructure. While the TVG has been previously considered a dormant or extinct volcano, recent evidence suggests a much younger age of the last eruption event (~ 6000 years) and possible existence of a magma reservoir beneath the TVG. However, the location, dimension, and detailed geometry of the magma reservoir and plumbing system remains largely unknown. To examine the TVG volcanic plumbing structure in detail, the local P-wave travel time data and the teleseismic waveform data from a new island-wide Formosa Array Project are combined for a 3D tomographic joint inversion. The new model reveals a magma reservoir with a notable P-wave velocity reduction of 19% (ca. ~ 19% melt fraction) at 8-20 km beneath eastern TVG and with possible northward extension to a shallower depth near where active submarine volcanoes that have been detected. Enhanced tomographic images also reveal sporadic magmatic intrusion/underplating in the lower crust of Husehshan Range and northern Taiwan. These findings suggest an active volcanic plumbing system induced by post-collisional extension associated with the collapse of the orogen.

Active Volcanism Revealed from a Seismicity Conduit in the Long-resting Tatun Volcano Group of Northern Taiwan.

Abundant earthquakes clustered within a particular zone often reflect an active geological feature, such as clustering seismicity along a fault zone and a huge number of volcanic-earthquakes around the erupting conduit. Herein we perform a double-difference tomographic inversion and relocate the seismicity at the long-resting Tatun volcano group (TVG) in northern Taiwan. A dramatic improvement of the earthquake location model surprisingly show that, from 2014 to 2017, two clustered seismic zones are identified in the TVG. One major group of events (>1000) persistently clustered within a ~500 m diameter vertical conduit with a ~2 km height. The clustering seismicity conduit is just located nearby Dayoukeng, one of the strongest fumaroles in the TVG, and is connected to a fracture zone characterized by low Vp/Vs in the shallow crust. The other group of events is clustered within a sphere-like zone beneath Mt. Chihsin around the depths between 0.5 km and 2 km. Both seismic zones are probably triggered by the significantly volcanic gases and fluids ascending from the deep magma reservoir. Combined with a variety of results from literature, the seismicity conduit near the strong fumarole is the evidence for an active volcano and also identifies a likely pathway for ascending magma if the TVG erupts again in the future. But possibility of developing different magma pathways at other clustered seismic zones such as beneath Mt. Chihsin may not be totally excluded.

Inverse Association Between Serum Osteoprotegerin and Bone Mineral Density in Renal Transplant Recipients.

BACKGROUND: Osteoprotegerin (OPG) has pleiotropic effects on bone metabolism as well as endocrine function. Our aim was to evaluate the relationship between bone mineral density (BMD) and serum OPG concentration in renal transplant recipients. METHODS: Fasting blood samples were obtained from 69 renal transplant recipients. BMD was measured in lumbar vertebrae (L2-L4) by dual-energy X-ray absorptiometry. Eight patients (11.6%) had BMD values indicative of osteoporosis, 28 patients (40.6%) had BMD values indicative of osteopenia, and 33 patients had normal BMD values. Increased serum OPG levels (P < .001), decreased body mass index (BMI) (P = .033), and decreased body weight (P = .010) were significantly correlated with low lumbar T-score cut-off points between groups (normal, osteopenia, and osteoporosis). RESULTS: Women had significantly lower lumbar BMD values than men (P = .013). Menopause (P = .005), use of tacrolimus (P = .020), and use of cyclosporine (P = .046) were associated with lower lumbar BMD in renal transplant recipients. Univariate linear regression analysis revealed that lumbar BMD was positively correlated with height (P = .016), body weight (P = .001), and BMI (P = .015) and negatively correlated with age (P = .039) and log-OPG (P = .001). Multivariate linear regression analysis revealed that log-OPG (ß: -0.275, R(2) change = 0.154, P = .014), body weight (ß: 0.334, R(2) change = 0.073, P = .004), and age (ß: -0.285, R(2) change = 0.079, P = .008) were independent predictors of lumbar BMD values in renal transplant recipients. CONCLUSIONS: Serum OPG concentration correlated negatively with lumbar BMD values in renal transplant recipients.

Hyperleptinemia Is a Risk Factor for the Development of Central Arterial Stiffness in Kidney Transplant Patients.

BACKGROUND: Arterial stiffness could cause adverse outcomes in kidney transplant (KT) patients. Leptin has a role in influencing vascular smooth muscle that may contribute to atherosclerosis. The aim of this study was to evaluate the relationship between fasting serum leptin concentration and carotid-femoral pulse wave velocity (cfPWV) in KT patients. MATERIALS AND METHODS: Fasting blood samples were obtained from 55 KT patients and 65 subjects from the outpatient department were enrolled as the control group. The cfPWV values of >10 m/s were used to define as the high arterial stiffness group and <10 m/s as the low arterial stiffness group. The predictive ability of leptin for arterial stiffness of KT was assessed using receiver operating characteristic (ROC) curve and multivariate logistic regression analyses. RESULTS: Kidney transplant patients had lower hemoglobin, but higher blood urea nitrogen, creatinine, total cholesterol, diastolic blood pressure, intact parathyroid hormone levels, and leptin levels than controls. Although cfPWV levels were higher in KT patients, there is no difference of cfPWV levels between KT patients and control (P = .595). Fifteen KT patients (27.3%) were defined in the high arterial stiffness group, and serum leptin level was higher in the high arterial stiffness group compared with the low arterial stiffness group in KT patients (P < .001). Multivariate logistic regression analysis showed that leptin (odds ratio: 1.044, 95% confidence interval [CI]: 1.016-1.072, P = .002) was an independent predictor of arterial stiffness in KT patients. The sensitivity, specificity, positive predictive value, negative predictive value, and area under the ROC curve predicting arterial stiffness in KT patients were 73.33%, 87.5%, 68.7%, 89.7%, and 0.828 (95% CI: 0.703-0.917, P < .001), and the leptin cut-off value was 74.14 ng/mL. CONCLUSION: Serum fasting leptin level could predict the development of central arterial stiffness of KT patients.

High prevalence of type 41 and high sequence diversity of partial hexon gene of human adenoviruses in municipal raw sewage and activated sludge.

AIM: This study was aimed to assess seasonal/geographical distribution and sequence diversity of partial hexon gene for human adenoviruses (HAdVs) within raw sewages (RS) and activated sludges (AS). METHODS AND RESULTS: Assessments were based on high-throughput sequencing (HTS) for polymerase chain reaction (PCR)-amplified 128-bp partial hexon gene fragments and followed by principal coordinate analyses (PCoA) for revealed sequences. Sequencing results showed that the majority of sequences (>90%) for the RS or AS samples were identical to HAdV type 41 of species F, while rest of few sequences belonged to HAdV species-D and -C were only occurred rarely without significant seasonal/geographical variation. The partial hexon genes were highly diverse as many sequence types and operational taxonomic unit groups were noticed among the matched sequences. CONCLUSIONS: This study demonstrated that HAdV-41 was constantly appeared in the RS and AS samples from Taiwan throughout the year without significant seasonal or geographical variations; but, had high sequence diverse noticed for the 128-bp partial hexon gene fragments. SIGNIFICANCE AND IMPACT OF THE STUDY: High-throughput-sequencing results provided better insights of HAdV distribution and genetic diversity for raw sewage and AS samples allowing some probable biases for cloning-sequencing approach to be defeated and further providing public health awareness regarding viral-contaminated sewages or sludges.

N-terminal pro-B-type natriuretic peptide is inversely related to bone mineral density in renal transplant recipients.

INTRODUCTION: Bone mineral density (BMD) was significantly lower in heart failure patients. Our aim was to evaluate the relationship between BMD and fasting serum N-terminal pro-B-type natriuretic peptide (NT-proBNP) concentration in renal transplant recipients. METHODS: Fasting blood samples were obtained from 69 renal transplant recipients. BMD was measured by dual energy x-ray absorptiometry in lumbar vertebrae (L2-L4). Serum NT-proBNP levels were measured by electrochemiluminescence immunoassay. RESULTS: Among the renal transplant recipients, 8 patients (11.6%) had osteoporosis and 28 (40.6%) had osteopenia; 33 had a normal BMD. Increased serum NT-proBNP (P < .001) and decreased body mass index (P = .033) and body weight (P = .010) were significantly correlated with low lumbar T-score cutoff points between groups (normal, osteopenia, and osteoporosis). Women had lower lumbar BMD than did men (P = .013). Menopause in women (P = .005), use of tacrolimus (P = .020), and use of cyclosporine (P = .046) among renal transplant recipients were associated with lower lumbar BMD. Multivariate forward stepwise linear regression analysis of the significant variables revealed that log-transformed NT-proBNP (ß, -0.545; R(2) = 0.331; P < .001), and body weight (ß, 0.273, R(2) = 0.104; P = .005) were independent predictors of lumbar BMD values among the renal transplant recipients. CONCLUSIONS: Serum NT-proBNP concentrations correlate negatively with lumbar BMD values among renal transplant recipients and may be an alternative to energy x-ray absorptiometry for identifying at risk of osteoporosis in renal transplant recipients.

Serum leptin levels positively correlate with peripheral arterial stiffness in kidney transplantation patients.

BACKGROUND: Leptin is a protein predominantly produced by adipocytes that plays a pathophysiologic role in the pathogenesis of hypertension and cardiovascular diseases. The aim of this study was to evaluate the relationship between fasting serum leptin levels and peripheral arterial stiffness among kidney transplant (KT) patients. METHODS: Fasting blood samples were obtained from 74 KT patients. Brachial-ankle pulse wave velocity (baPWV) was measured in the right or left brachial artery to the ankle segments using an automatic pulse wave analyzer (VaSera VS-1000). Plasma leptin levels were measured using a commercial enzyme-linked immunosorbent assay kit. In this study, left or right baPWV values of less than 14.0 m/s were used to define the high arterial stiffness group. RESULTS: Forty KT patients (54.1%) were defined in high arterial stiffness group. Hypertension (P < .010), diabetes (P < .010), age (P = .010), KT duration (P = .013), triglyceride levels (P = .016), systolic blood pressure (P < .001), waist circumference (P = .031), and leptin level (P < .001) were higher, whereas serum high-density lipoprotein cholesterol level (P = .030) was lower in the high arterial stiffness group compared with the low arterial stiffness group. Multivariate logistic regression analysis showed that leptin (odds ratio, 1.033; 95% CI, 1.004-1.062; P = .023), KT duration (odds ratio, 1.023; 95% CI, 1.004-1.044; P = .020), and high-density lipoprotein cholesterol level (odds ratio, 0.925; 95% CI, 0.872-0.982; P = .010) were the independent predictors of peripheral arterial stiffness in KT patients. CONCLUSIONS: Serum fasting leptin level was positively associated with peripheral arterial stiffness among KT patients.

Quantum efficiency enhancement in selectively transparent silicon thin film solar cells by distributed Bragg reflectors.

This work demonstrated a-Si:H thin-film solar cells with backside TiO(2)/ SiO(2) distributed Bragg reflectors (DBRs) for applications involving building-integrated photovoltaics (BIPVs). Selectively transparent solar cells are formed by adjusting the positions of the DBR stop bands to allow the transmission of certain parts of light through the solar cells. Measurement and simulation results indicate that the transmission of blue light (430 ~500 nm) with the combination of three DBR mirrors has the highest increase in conversion efficiency.

An omni-directional mid-infrared tunable plasmonic polarization filter.

In this paper, we show that a localized surface plasmon polariton in a plasmonic sandwich structure made of a (metal elliptical disc)/(dielectric spacer)/(metal film) can be used as an efficient angle-independent polarizer in the mid-infrared wavelength regime. The elliptical disc structure is characterized by using a Fourier transform infrared spectrometer and simulated via the rigorous coupled wave analysis (RCWA) method. For the optimum design, we can obtain a degree of polarization of 99% both experimentally and theoretically. A high extinction ratio between 20 and 40 dB can be obtained by changing the axis ratio of the elliptical disc between 0.65 and 0.85. The wavelength of polarized light can be tuned in a wide range by changing the structural parameters. The plasmon-polariton band structures of the elliptical disc structure for both TM and TE polarizations are also studied theoretically via RCWA.

Fasting long-acting natriuretic peptide correlates inversely with metabolic syndrome in kidney transplant patients.

The metabolic syndrome (MetS) is a risk factor for posttransplant diabetes mellitus, chronic graft dysfunction, graft loss, occurrence of atherosclerotic events, and patient death among kidney transplantation patients. Long-acting natriuretic peptide (LANP) is among the peptide hormones in atrial natriuretic peptide prohormone. Low levels of natriuretic peptide may lead to reduced lipolysis and excessive weight gain in obese patients. This study was undertaken to evaluate the relationship between MetS and fasting serum LANP concentration among kidney transplanted patients. Fasting blood samples were obtained from 69 kidney recipients. The MetS and its components were defined using the diagnostic criteria of the International Diabetes Federation. Fasting LANP levels were measured using a commercial enzyme immunoassay kit. The prevalence rate of MetS was 20.3% (14/69). Fasting LANP level negatively correlated with MetS among these patients (P = .010). Using univariate linear regression analysis, serum LANP values were negatively correlated with hemoglobin (r = -0.252; P = .037), and positively correlated with blood urea nitrogen (r = 0.254; P = .035) and creatinine (r = 0.311; P = .009). Multivariate forward stepwise linear regression analysis of the significant variables revealed that creatinine (R(2) change = 0.097; P = .009) was an independent predictor of fasting serum LANP concentration among kidney transplanted patients. Serum LANP concentration correlates inversely with MetS; for these patients, creatinine is an independent predictor of the serum LANP value.

Quantum efficiency enhancement in selectively transparent silicon thin film solar cells by distributed Bragg reflectors.

This work demonstrated a-Si:H thin-film solar cells with backside TiO(2) / SiO(2) distributed Bragg reflectors (DBRs) for applications involving building-integrated photovoltaics (BIPVs). Selectively transparent solar cells are formed by adjusting the positions of the DBR stop bands to allow the transmission of certain parts of light through the solar cells. Measurement and simulation results indicate that the transmission of blue light (430 ~500 nm) with the combination of three DBR mirrors has the highest increase in conversion efficiency.

Hypoadiponectinemia correlates with metabolic syndrome in kidney transplantation patients.

Serum adiponectin values correlate inversely with the presence of metabolic syndrome (MS). This study was undertaken to evaluate the relationship between MS and fasting serum adiponectin concentrations in 55 kidney transplantation patients. MS and its components were defined using the diagnostic criteria of the International Diabetes Federation. Thirteen subjects (23.6%) with MS showed negative correlations with adiponectin levels (P = .035), which also negatively correlated with a number of MS criteria (P = .015). Univariate linear regression analysis showed, serum adiponectin values to negatively correlate with waist circumference (r = -0.367; P = .006), body mass index (r = -0.306; P = .023), and body fat mass (r = -0.373; P = .005). Multivariate forward stepwise linear regression analysis of the significant variables revealed that body fat mass (R(2) change = 0.139; P = .035) and waist circumference (R(2) change = 0.067; P = .041) were independent predictors of fasting serum adiponectin concentrations. Thus, serum adiponectin concentrations correlated inversely with MS. Body fat mass and waist circumference were independent predictors of serum adiponectin values in kidney transplant patients.

Angle-independent plasmonic infrared band-stop reflective filter based on the Ag/SiO2/Ag T-shaped array.

A plasmonic infrared (IR) filter assisted by localized surface plasmon polaritons (LSPPs) in a Ag/SiO2/Ag T-shaped array was theoretically and experimentally investigated. By using a Fourier transform infrared (FTIR) spectrometer, an angle-independent LSPP resonant mode caused by a Fabry-Pérot resonance in the structure was observed in agreement with the prediction from the rigorous coupled-wave analysis (RCWA) simulation. The resonant wavelength of the mode can also be controlled by modifying the geometry of the T-shaped structure. Such LSPP property can be used as an IR reflection-type band-stop filter with a single spectral bandwidth and an ultrahigh immunity to incident angles.

Plasmon-polariton band structures of asymmetric T-shaped plasmonic gratings.

It is shown that asymmetric T-shaped plasmonic gratings can display plasmon-polariton band structures with wide range of band gaps and tunable group velocities. A structure gap is introduced in the post of Tshaped plasmonic gratings and it is found that the size of this gap plays an important role in controlling the plasmon-polariton band gap and group velocities. We obtained variation of energy band gap ranging from 0.4 eV to 0.0323 eV by changing the size of the structure gap from 0 to 250 nm. The plasmon-polariton band structures were obtained by using Rigorous Coupled Wave Analysis. We studied the difference between symmetric and asymmetric T-shaped gratings and found that the symmetric structure has a momentum gap in the photonic band structure, which can be avoided in the asymmetric structure. Furthermore, by varying the post and spacer (made of SiO2) thicknesses we can tune the energy band gap from 0.1 eV to 0.148 eV and from 0.183 eV to 0.19 eV, respectively. In this device, we obtain tunable group velocities ranging from one to several orders of magnitude smaller than the speed of light in the vacuum. This asymmetric T-shaped plasmonic grating is expected to have applications in surface plasmon polariton (SPP) based optical devices, such as filters, waveguides, splitters and lasers, especially for applications requiring large photonic band gap.

Polarity-variable birefringence on hyperlens structure.

A variable birefringence effect has been observed with 1D PMMA surface gratings on a gold film substrate. By changing the operation wavelength on the Au film, the birefringence value Δn(eff) changes from positive to negative. The result verified that this uniaxial crystal-like plasmonic surface gratings showed good superlensing effect at 515 nm when PMMA width:Air width=1:1 where the absolute value of Δn(eff) is relatively large.

Compact optical curvature sensor with a flexible microdisk laser on a polymer substrate.

We demonstrate a chip-scale compact optical curvature sensor. It consists of a low threshold InGaAsP microdisk laser on a flexible polydimethylsiloxane polymer substrate. The curvature dependence of lasing wavelength was characterized by bending the cavity at different bending radii. The measurements showed that the lasing wavelength decreases monotonously with an increasing bending curvature. A good agreement between experiment and three-dimensional finite-difference time-domain simulation was also obtained. The sensitivity of the compact device to the bending curvature is -23.7 nm/mm from the experiment.

Flexible compact microdisk lasers on a polydimethylsiloxane (PDMS) substrate.

Compact microdisk cavities were fabricated on a polydimethylsiloxane substrate. The lasing of the flexible compact cavity was achieved with a low threshold power. The whispering-gallery mode of the microdisk was also characterized with three-dimensional finite-difference time-domain simulation. The curvature dependence in output power and threshold was also demonstrated by bending the microdisk cavity.

Photonic crystal lasers in InGaAsP on a SiO(2)/Si substrates and its thermal impedance.

Two-dimensional photonic crystal defect lasers in InGaAsP membranes directly bonded to a SiO(2)/Si substrate have been demonstrated. Lasing at wavelengths near 1550 nm was obtained with incident threshold pump powers as low as 1.5 mW. Good agreement between experimental data and three-dimensional finite-difference time-domain (FDTD) simulation was achieved. The thermal impedance of this laser is also characterized.