-
Optics Express Apr 2024We report a 4.3 µm mid-infrared (mid-IR) high-power amplified spontaneous emission (ASE) fiber source based on CO-filled nested hollow-core anti-resonant fiber...
We report a 4.3 µm mid-infrared (mid-IR) high-power amplified spontaneous emission (ASE) fiber source based on CO-filled nested hollow-core anti-resonant fiber (Nested HC-ARF). The pump source is a homemade hundred-watt-level wavelength-tunable 2 µm single-frequency fiber laser. A 5.7 m long 8-tube Nested HC-ARF is used as the gas cell, with a core diameter of 110 µm and cladding diameter of 400 µm, which exhibits transmission loss of 0.1 dB/m at 2 µm and 0.24 dB/m at 4.3 µm respectively. To improve the coupling efficiency of the high-power pump laser and reduce the influence of the thermal effect at the input end of the hollow-core fiber, the fiber is designed for multimode transmission at the pump wavelength. A continuous wave output power of 6.6 W at 4.3 µm is achieved, and the slope efficiency is 17.05%. To the best of our knowledge, it is the highest output power for such gas-filled HC-ARF ASE sources in 4∼5 µm. This work demonstrates the great potential of gas-filled HC-ARF generating high-power mid-IR emission.
PubMed: 38859395
DOI: 10.1364/OE.517713 -
Optics Express Apr 2024In this paper, a hundred-watt-level near-diffraction-limited step-index Yb-doped fiber (YDF) laser near 980 nm is demonstrated firstly, to the best of our knowledge. By...
In this paper, a hundred-watt-level near-diffraction-limited step-index Yb-doped fiber (YDF) laser near 980 nm is demonstrated firstly, to the best of our knowledge. By using the 11.7-W 979-nm single-mode seed light, the in-band amplified spontaneous emission (ASE) is well suppressed and the maximum output power of 101.5 W with the beam quality (M factor) of 1.285 was obtained. This work does not only propose an effective method for the suppression of in-band ASE, but also provides a cost-effective solution of hundred-Watt-level near-diffraction-limited fiber lasers near 980 nm.
PubMed: 38859289
DOI: 10.1364/OE.517764 -
Optics Express May 2024We report on the Czochralski crystal growth, polarized optical spectroscopy, and the first continuous-wave laser operation of 1.5 at.% Tm:LuVO crystal on the H → H...
We report on the Czochralski crystal growth, polarized optical spectroscopy, and the first continuous-wave laser operation of 1.5 at.% Tm:LuVO crystal on the H → H transition. The polarized absorption and stimulated-emission properties of Tm ions in LuVO were revised and the crystal-field splitting of the Tm multiplets was determined by low-temperature (12 K) spectroscopy. The maximum stimulated-emission cross-section for the H → H transition is 2.48 × 10 cm at 2363 nm for π-polarization corresponding to an emission bandwidth of 28 nm. Evidence of phonon-assisted emissions of Tm ions above 2 µm is presented. The broadband emission properties of the Tm:LuVO crystal make it promising for ultrashort pulse generation. Additionally, pumped by a 796 nm fiber-coupled laser diode, the Tm:LuVO laser generated a Watt-level output power at 2279-2295 nm with a slope efficiency of 9.2% and linearly polarized emission (π-polarization).
PubMed: 38859092
DOI: 10.1364/OE.517124 -
Scientific Reports Jun 2024Data-driven approaches are often utilized to model and generate vibrotactile feedback and sounds for rigid stylus-based interaction. Nevertheless, in prior research,...
Data-driven approaches are often utilized to model and generate vibrotactile feedback and sounds for rigid stylus-based interaction. Nevertheless, in prior research, these two modalities were typically addressed separately due to challenges related to synchronization and design complexity. To this end, we introduce a novel multimodal multitask deep learning framework. In this paper, we developed a comprehensive end-to-end data-driven system that encompasses the capture of contact acceleration signals and sound data from various texture surfaces. This framework introduces novel encoder-decoder networks for modeling and rendering vibrotactile feedback through an actuator while routing sound to headphones. The proposed encoder-decoder networks incorporate stacked transformers with convolutional layers to capture both local variability and overall trends within the data. To the best of our knowledge, this is the first attempt to apply transformer-based data-driven approach for modeling and rendering of vibrotactile signals as well as sounds during tool-surface interactions. In numerical evaluations, the proposed framework demonstrates a lower RMS error compared to state-of-the-art models for both vibrotactile signals and sound data. Additionally, subjective similarity evaluation also confirm the superiority of proposed method over state-of-the-art.
PubMed: 38858511
DOI: 10.1038/s41598-024-64376-y -
Scientific Reports Jun 2024In this work we demonstrate a miniaturised imaging system based around a time-gated SPAD array operating in a "chip-on-tip" manner. Two versions of the system are...
In this work we demonstrate a miniaturised imaging system based around a time-gated SPAD array operating in a "chip-on-tip" manner. Two versions of the system are demonstrated, each measuring 23 mm × 23 mm × 28 mm with differing fields of view and working distances. Initial tests demonstrate contrast between materials in widefield fluorescence imaging (WFLIm) mode, with frame rates of > 2 Hz achievable. Following this, WFLIm images of autofluorescence in ovine lung tissue are obtained at frame rates of ~ 1 Hz. Finally, the ability of the second system to perform simultaneous WFLIm and time of flight (aka Flourescence Lifetime Imaging Distance and Ranging, FLImDAR) is also tested. This shows that the system is capable of 4 mm resolution of object separation when tested on 3D printed samples. It is further demonstrated as being able to perform scene reconstruction on autofluorescent lung tissue. This system is, to date, the smallest chip on tip WFLIm system published, and is the first demonstration of the FLImDAR technique in a compact, portable system.
PubMed: 38858419
DOI: 10.1038/s41598-024-63409-w -
Exploration of Medicine 2024Endothelial dysfunction has been associated with both cerebrovascular pathology and Alzheimer's disease (AD). However, the connection between circulating endothelial...
AIM
Endothelial dysfunction has been associated with both cerebrovascular pathology and Alzheimer's disease (AD). However, the connection between circulating endothelial cells and the risk of AD remains uncertain. The objective was to leverage data from the Framingham Heart Study to investigate various circulating endothelial subtypes and their potential correlations with the risk of AD.
METHODS
The study conducted data analyses using Cox proportional hazard regression and linear regression methods. Additionally, genome-wide association study (GWAS) was carried out to further explore the data.
RESULTS
Among the eleven distinct circulating endothelial subtypes, only circulating endothelial progenitor cells (EPCs) expressing CD34+CD133+ were found to be negatively and dose-dependently associated with reduced AD risk. This association persisted even after adjusting for age, sex, years of education, apolipoprotein E () ε4 status, and various vascular diseases. Particularly noteworthy was the significant association observed in individuals with hypertension and cerebral microbleeds. Consistently, positive associations were identified between CD34+CD133+ EPCs and specific brain regions, such as higher proportions of circulating CD34+CD133+ cells correlating with increased volumes of white matter and the hippocampus. Additionally, a GWAS study unveiled that CD34+CD133+ cells influenced AD risk specifically in individuals with homozygous genotypes for variants in two stem cell-related genes: kirre like nephrin family adhesion molecule 3 (, rs580382 CC and rs4144611 TT) and exocyst complex component 6B (, rs61619102 CC).
CONCLUSIONS
The findings suggest that circulating CD34+CD133+ EPCs possess a protective effect and may offer a new therapeutic avenue for AD, especially in individuals with vascular pathology and those carrying specific genotypes of and genes.
PubMed: 38854406
DOI: 10.37349/emed.2024.00216 -
Talanta Jun 2024Ammonia is a prevalent aquatic pollutant that disrupts cellular functions and energy metabolism in fish, posing significant environmental and health threats. This...
Ammonia is a prevalent aquatic pollutant that disrupts cellular functions and energy metabolism in fish, posing significant environmental and health threats. This research investigates the critical role of arginase 2 (ARG2) in mitigating ammonia toxicity in fish cells and its implications in adapting to nitrogen metabolism under high ammonia exposure. Through a CRISPR-Cas9 engineered ARG2 knockdown (KD) in the Epithelioma Papulosum Cyprini (EPC) cell line, we first investigated the biochemical responses of ARG2 KD and wild-type (WT) EPC cells to ammonia stress (NHCl treatment), showing diminished urea production and decreased cell viability in ARG2 KD cells. Subsequently, single-cell Raman spectroscopy analysis revealed that ARG2 KD cells exhibited profound metabolic shifts, including changes in protein, nucleic acids, lipid and sugar levels, showing the adjusting role of ARG2 in the balance of carbohydrate and nitrogen metabolism. Furthermore, the upregulated responses of various amino acids, such as glutamine, arginine, alanine, glutamic acid, glycine, histidine, phenylalanine and valine, in WT cells after NHCl treatment diminished in ARG2 KD cells except for the decrease in aspartic acid, indicating a switching effect of ARG2 in nitrogen metabolism under ammonia stress. This study highlights ARG2's essential role in ammonia detoxification and emphasizes ARG2's protective function and its importance in metabolism, shedding light on the adaptive mechanisms fish cells deploy against high ammonia environments. These insights contribute to deep understanding of aquatic organisms' molecular responses to environmental ammonia pollution, offering potential strategies for their protection.
PubMed: 38852346
DOI: 10.1016/j.talanta.2024.126389 -
Evidence-based Dentistry Jun 2024Interrupted time series analysis.
DESIGN
Interrupted time series analysis.
DATA ANALYSIS
An interrupted time series (ITS) analysis was conducted to determine if there was an association between the announcement and implementation of the soft drinks industry levy (SDIL) and rates of hospital admission for tooth extractions due to dental caries in children. Hospital Episode Statistics (HES) were used on hospital admissions for tooth extraction of one or more primary or permanent tooth due to a primary diagnosis of dental caries in children aged 0-18 years attending a National Health Service (NHS) hospital in England from January 2012 (pre-SDIL) to February 2020 (post-SDIL implementation). HES data were grouped and summarised by Index of Multiple Deprivation (IMD) and age group.
RESULTS
There was an absolute reduction of 3.7% (95% CI 5.3% to 2.2%) per 100,000 population/month and a relative reduction of 12.1% (95% CI 17.0% to 7.2%) in hospital admissions for carious tooth extractions in all children (0-18 years) compared if there had been no announcement of the SDIL (counterfactual scenario). Reductions were observed in children living in most areas regardless of the level of deprivation and most notably in the youngest children (<10 years).
CONCLUSIONS
An ITS analysis of administrative data on hospital admissions found the announcement of the UK SDIL was associated with improvements (reduction) in the incidence of hospital admissions for tooth extractions due to dental caries. This study provides evidence of benefits of the UK SDIL to children's oral health.
Topics: Humans; Child; Dental Caries; Child, Preschool; Adolescent; Infant; Carbonated Beverages; Interrupted Time Series Analysis; United Kingdom; Male; Female; Tooth Extraction; Infant, Newborn; Hospitalization; Food Industry; England
PubMed: 38844545
DOI: 10.1038/s41432-024-01025-3 -
Chemosphere Jun 2024The discharge of heavy metals into the environment has adversely affected the aquatic ecosystem due to their toxic and non-biodegradable nature. In this research, a...
The discharge of heavy metals into the environment has adversely affected the aquatic ecosystem due to their toxic and non-biodegradable nature. In this research, a three-dimensional graphene oxide/carboxymethylcellulose/aluminium sulphate (GOCAS) aerogel was synthesised and evaluated as a novel means for lead and zinc removal. The GOCAS aerogel was prepared via ice-templating of graphene oxide with carboxymethylcellulose and aluminium sulphate as the crosslinking and functionalisation additives. Characterisation of the aerogel by various analytical techniques confirmed the successful integration of the chemical additives. The hydroxyl and sulphate groups in the aerogel were found to participate in the adsorption of both metals. The equilibrium of lead adsorption was found to correlate well to the Freundlich isotherm, while zinc adsorption fitted closely the Langmuir isotherm. The kinetic adsorption behaviour of both metals was best described as pseudo-second-order. The interactive influences of concentration, temperature, contact time and adsorbent dose on the metal removal were explored by a central composite design, and the optimum adsorption capacity for lead was determined to be 138.7 mg/g at a GOCAS dose of 20 mg, initial concentration of 100 mg/L, temperature of 50 °C and contact time of 45 min. The optimum adsorption capacity for zinc was 52.69 mg/g at 30 mg, 65 mg/L, 45 °C and 40 min. Furthermore, regeneration studies with hydrochloric acid eluant were successfully conducted for up to four adsorption-desorption cycles. Overall, this work demonstrates that GOCAS aerogel is a viable nanosorbent for the adsorption of lead and zinc from water systems.
PubMed: 38844101
DOI: 10.1016/j.chemosphere.2024.142537 -
Soft Matter Jun 2024Correction for 'Flax fibre reinforced alginate poloxamer hydrogel: assessment of mechanical and 4D printing potential' by Charles de Kergariou , , 2024, , 4021-4034,...
Correction for 'Flax fibre reinforced alginate poloxamer hydrogel: assessment of mechanical and 4D printing potential' by Charles de Kergariou , , 2024, , 4021-4034, https://doi.org/10.1039/D4SM00135D.
PubMed: 38841883
DOI: 10.1039/d4sm90089h