Integrating inverse design and partially etched platform: an ultra-compact polarization splitter and rotator as an example.

Silicon photonics devices benefit greatly from a partially etched platform and inverse design. Herein, we propose a bi-layer polarization splitter and rotator with a topology pattern and demonstrate it on a silicon-on-insulator platform. Our device exhibits a significantly reduced physical footprint of only 2µm×6µm, compared to traditional directional couplers and tapered waveguides. The device accomplishes the functions of polarization conversion and separation in such a compact design without redundant tapered or bending waveguides. The tested minimum insertion loss with the fabrication batch reaches 0.57 and 0.67 dB for TE and TM modes, respectively. The TE mode demonstrates a wider bandwidth and lower ILs than the TM modes, averaging around 1 dB from 1530 to 1565 nm. The M modes exhibit approximately 2 dB ILs at the same wavelength range, decreasing to about 1 dB between 1565 and 1580 nm. Improved designs and fabrication conditions strongly suggest the potential for further performance enhancement in the device. This successful initiative validates the exceptional performance resulting from the integration of the partially etched platform and inverse design, providing valuable insights for future photonic integrated device designs.

Compact dual-mode waveguide crossing based on adjoint shape optimization.

We design, fabricate, and characterize a compact dual-mode waveguide crossing on a silicon-on-insulator platform. The dual-mode waveguide crossing with high performance is designed by utilizing the adjoint shape optimization. This adjoint-method-based optimization algorithm is computationally efficient and yields the optimal solution in fewer iterations compared with other iterative schemes. Our proposed dual-mode waveguide crossing exhibits low insertion loss and low crosstalk. Experimental results show that the insertion losses at the wavelength of 1550 nm are 0.83 dB and 0.50 dB for TE0 and TE1 modes, respectively. The crosstalk is less than -20 dB for the two modes over a wavelength range of 80 nm. The footprint of the whole structure is only 5 × 5 µm2.

Immunosenescence of brain accelerates Alzheimer's disease progression.

Most of Alzheimer's disease (AD) cases are sporadic and occur after age 65. With prolonged life expectancy and general population aging, AD is becoming a significant public health concern. The immune system supports brain development, plasticity, and homeostasis, yet it is particularly vulnerable to aging-related changes. Aging of the immune system, called immunosenescence, is the multifaceted remodeling of the immune system during aging. Immunosenescence is a contributing factor to various age-related diseases, including AD. Age-related changes in brain immune cell phenotype and function, crosstalk between immune cells and neural cells, and neuroinflammation work together to promote neurodegeneration and age-related cognitive impairment. Although numerous studies have confirmed the correlation between systemic immune changes and AD, few studies focus on the immune state of brain microenvironment in aging and AD. This review mainly addresses the changes of brain immune microenvironment in aging and AD. Specifically, we delineate how various aspects of the brain immune microenvironment, including immune gateways, immune cells, and molecules, and the interplay between immune cells and neural cells, accelerate AD pathogenesis during aging. We also propose a theoretical framework of therapeutic strategies selectively targeting the different mechanisms to restore brain immune homeostasis.

Effects of backhand stroke styles on bone mineral content and density in postmenopausal recreational tennis players: a cross-sectional pilot investigation.

BACKGROUND: One-handed backhand (OB) and two-handed backhand (TB) styles are commonly used in tennis, but only TB generates loadings on the non-dominant arm and a greater extension torque on the rear leg, leading to a greater axial torque involving rotation of the hip and trunk. The current study investigated whether those effects can further affect bone area (BA), bone mineral content (BMC) and density (BMD) in postmenopausal recreational tennis players. METHODS: BA, BMC and BMD of the lumbar spine, hip and distal radius were assessed using dual-energy X-ray absorptiometry in TB, OB, and swimmers' group as a control (SG) (all participants self-reported for at least 5 years of exercise history, n = 14 per group). Muscular strength was assessed with a hand dynamometer. Among these three groups, the BA, BMC and BMD of distal radius and muscle strength were assessed using one-way ANOVA, and those of the lumbar region and the hip joint were tested by one-way ANCOVA. RESULTS: TB showed higher BMC and BMD for both lumbar spine and femoral neck than SG (all, p < 0.05). Both OB and TB showed greater BMD inter-trochanter than SG (both, p < 0.05). OB demonstrated greater inter-arm differences in the distal radius, which involved 1/3 distal for BMC and mid-distal radius for BMD compared to the TB and SG (all, p < 0.05). In addition, greater inter-arm asymmetry of grip strength was found in OB compared to TB and SG (both, p < 0.05). CONCLUSION: For postmenopausal women, performing two-handed backhand strokes, leads to higher BMC and BMD in the non-dominant arm, the lumbar region, and hips, indicating potential benefit to maintain bone health and strength. Whether this result leads to reducing the risk of osteoporosis needs to be investigated in further research.

Breath Acetone Sensing Based on Single-Walled Carbon Nanotube-Titanium Dioxide Hybrids Enabled by a Custom-Built Dehumidifier.

Acetone is a metabolic byproduct found in the exhaled breath and can be measured to monitor the metabolic degree of ketosis. In this state, the body uses free fatty acids as its main source of fuel because there is limited access to glucose. Monitoring ketosis is important for type I diabetes patients to prevent ketoacidosis, a potentially fatal condition, and individuals adjusting to a low-carbohydrate diet. Here, we demonstrate that a chemiresistor fabricated from oxidized single-walled carbon nanotubes functionalized with titanium dioxide (SWCNT@TiO2) can be used to detect acetone in dried breath samples. Initially, due to the high cross sensitivity of the acetone sensor to water vapor, the acetone sensor was unable to detect acetone in humid gas samples. To resolve this cross-sensitivity issue, a dehumidifier was designed and fabricated to dehydrate the breath samples. Sensor response to the acetone in dried breath samples from three volunteers was shown to be linearly correlated with the two other ketone bodies, acetoacetic acid in urine and ß-hydroxybutyric acid in the blood. The breath sampling and analysis methodology had a calculated acetone detection limit of 1.6 ppm and capable of detecting up to at least 100 ppm of acetone, which is the dynamic range of breath acetone for someone with ketosis. Finally, the application of the sensor as a breath acetone detector was studied by incorporating the sensor into a handheld prototype breathalyzer.

Effects of caffeine and sex on muscle performance and delayed-onset muscle soreness after exercise-induced muscle damage: a double-blind randomized trial.

The present study aims to investigate effects of caffeine ingestion and sex difference on muscle performance, delayed-onset muscle soreness (DOMS), and various biomarkers under exercise-induced muscle damage (EIMD). Twenty (10 male and 10 female) healthy elite college athletes were recruited. Participants ingested either caffeine (6 mg/kg) or a placebo in a randomized, double-blind, and counterbalanced fashion at 24 and 48 h following EIMD. Muscle performance, DOMS, and blood samples were taken an hour before and an hour after supplementation. Caffeine ingestion restored impaired maximal voluntary isometric contractions (MVIC: 10.2%; MVICpost: 7.2%, both P < 0.05) during EIMD across both sexes. Following caffeine ingestion during MVIC, while affected by EIMD, an interaction was found in DOMS and serum K+ (both P < 0.05), with males showing greater attenuation (21.5 and 16.9%, respectively) compared with females (4.6 and 1.3%, respectively). DOMS demonstrated an inverse correlation with MVIC after caffeine ingestion both overall and among male athletes (r = -0.34 and -0.54, respectively; P < 0.05) but not among female athletes (r = -0.11; P > 0.05) under EIMD. In addition, caffeine ingestion increased postexercise serum glucose and lactate concentrations across both sexes (both P < 0.05). This is the first study to show that male athletes, compared with female athletes, experience a greater reduction in DOMS during enhanced MVIC when caffeine was consumed, suggesting men might receive greater ergogenic effects from caffeine when affected by EIMD. Furthermore, caffeine ingestion was able to restore impaired muscle power among elite collegiate athletes across both sexes.NEW & NOTEWORTHY Exercise-induced muscle damage (EIMD) reduces anaerobic/aerobic performance and increases delayed-onset muscle soreness (DOMS) during exercise. We show that acute caffeine supplementation at a dosage of 6 mg/kg seems to facilitate recovery of anaerobic muscle power and attenuate DOMS after EIMD across both sexes. Furthermore, male athletes, compared with female athletes, when caffeine was prescribed, experience a greater reduction in DOMS with better restoration of impaired maximal voluntary isometric contractions. This suggests that male athletes might benefit from the ergogenic effect of acute caffeine supplementation after the onset of EIMD.

Comprehensive assessment of coastal eutrophication in Taiwan and its implications for management strategy.

Due to the rapid population growth, anthropogenic activities result in agricultural, industrial, and urban diffuse runoffs that elevate the level of nutrients such as nitrogen and phosphorus in coastal waters. Currently there is no integrated analysis for coastal eutrophication in Taiwan. A comprehensive analysis of the coastal eutrophic status was performed in this study based on decade-long coastal water quality monitoring data from Taiwan's Environmental Protection Administration. A 3-tiered monitoring strategy is recommended based on the severity of the current eutrophication state. Results indicate that the most problematic area of coastal eutrophication is located in the estuary of the Donggang River (DGR) and its adjacent coastal waters, i.e., the Kao-Ping mouth (KPM) and Dapeng Bay (DPB) in south-western Taiwan. With a worsening eutrophic status, these areas demand intensive monitoring and research with higher spatial and temporal resolutions to evaluate the stresses of nutrient forcing and predict possible future responses.

Utility of fluorescence in situ hybridization for ploidy and p57 immunostaining in discriminating hydatidiform moles.

Discrimination between complete moles (CMs), partial moles (PMs), and hydropic abortions (HAs) is important as the risk of persistent gestational trophoblastic disease (GTD) differs for each condition. We evaluated whether ancillary fluorescence in situ hybridization (FISH) with a set of chromosome enumeration probes (CEP) for chromosomes X, Y, and 17 and p57 immunostaining could improve the clinical diagnosis. Forty-one products of conception (POC) were reclassified according to clinical performance, morphology, p57 immunostaining results, and FISH results. The accuracy of histological examination alone was 85% for the original diagnosis. FISH analysis showed diploidy in 19 of 20 CMs and triploidy in 4 of 6 PMs. The concordance rate was 92.5% on using the CEP probes. p57 Staining was negative in all CMs and positive in all PMs and HAs. Chromosomal abnormality was detected in 3 cases of HA by using FISH. In conclusion, combined p57 immunostaining and FISH with a set of 3 CEP probes for chromosomes X, Y, and 17 could be useful in the classification of hydatidiform moles.