Search Results (181)

Gas leak detection in industrial environments poses critical safety challenges that require algorithms capable of balancing rapid source identification with comprehensive spatial coverage. Conventional approaches using fixed sensor networks provide limited coverage, while manual inspection methods expose personnel to hazardous conditions. This paper presents a novel Gradient-Guided Depth-First Search (GG-DFS) algorithm designed for autonomous mobile robots, which integrates gradient-following behavior with systematic exploration guarantees. The algorithm utilizes local concentration gradient estimation to direct movement toward leak sources while implementing depth-first search with backtracking to ensure complete environmental coverage. We assess the performance of GG-DFS through extensive simulations comprising 160 independent runs with varying leak configurations (1–4 sources) and starting positions. Experimental results show that GG-DFS achieves rapid initial source detection $(9.3\pm 7.3\mathrm{steps};\mathrm{mean}\pm \mathrm{SD})$, maintains 100% coverage completeness with 100% detection reliability, and achieves 50% exploration efficiency. In multi-source conditions, GG-DFS requires 70% fewer detection steps in four-leak scenarios compared to single-leak environments due to gradient amplification effects. Comparative evaluation demonstrates a substantial improvement in detection speed and efficiency over standard DFS, with GG-DFS achieving a composite performance score of 0.98, compared to 0.65 for standard DFS, 0.64 for the lawnmower pattern, and 0.53 for gradient ascent. These findings establish GG-DFS as a robust and reliable framework for safety-critical autonomous environmental monitoring applications. Full article

Background: The KMT2A (MLL1) gene is altered in a variety of hematological malignancies and solid tumors. KMT2A-rearranged (KMT2Ar) AML represents a distinct subtype associated with poor outcomes and high relapse rate despite initial responsiveness to chemotherapy. Methods: A total of 3863 cases of AML peripheral blood samples were analyzed using the FoundationOne Heme combined comprehensive hybrid capture-based DNA and RNA sequencing assay. Results: Of the 3863 AML cases, 521 (13.4%) featured genomic alterations (GAs) in the KMT2A gene, 99.1% of which were large rearrangements (KMT2Ar). A total of 56.9% were males with a median age of 62 years. Of the KMT2Ar cases, there were 43.1% KMT2A duplications, 52.7% fusions, and 4.2% not otherwise specified rearrangements. A total of 0.9% of the KMT2A-altered AML cases were short variant mutations. There were no KMT2A (0%) amplifications or deletions. KMT2Ar cases were associated with increased GA frequencies in FLT3 (27.3% vs. 19.8%; p = 0.0002), KRAS (17.2% vs. 7.8%; p < 0.0001) (overall; 1.1% KRAS G12C), and IDH2 (16.0% vs. 10.4%; p < 0.0001), while KMT2A wild-type AML (KMT2Awt) had significantly increased GA frequencies in RUNX1 (20.7% vs. 15.8%; p = 0.0081), ASXL1 (16.6% vs. 10.5%; p = 0.0003), and TET2 (16.4% vs. 10.1%; p = 0.0002), NPM1 (17.5% vs. 0.2%; p < 0.0001), and TP53 (17.8% vs. 7.9%; p < 0.0001). Conclusions: KMT2A rearrangements are common in AML (13.4% of cases featured KMT2Ar). A total of 99.1% of alterations in KMT2A are large rearrangements, with fusions being the most commonly observed alteration (52.7% of total rearrangements). No amplifications or deletions were seen. This genomic landscape study highlights significant genomic differences between KMT2Ar and KMT2Awt AML patients, which may enrich our understanding of the molecular profile and clusters of mutations in AML. Full article

By solving the three-dimensional Schrödinger equation with a second-order implicit Finite Difference Method (FDM), the combined effects of temperature, morphology, hydrostatic pressure, and transverse electric field on the nonlinear optical rectification (NOR) of GaAs/Al_εGa_1−εAs elliptical quantum rings are examined. The NOR amplitude is twelve times enhanced and a noticeable blue shift is induced in the THz region when the electric field is increased. Consequently, with the electric field of 1 × 10⁵ V/m, the NOR magnitude achieves its maximum value of 17.116 × 10⁵ m/V. Additionally, when the electric field is aligned along one side of the system’s in-plane cross-section, the strongest amplification takes place. However, with corresponding spectrum shifts, the NOR intensity rises with temperature and falls with hydrostatic pressure. Additionally, changing the transverse profile of the quantum ring from triangular to parabolic broadens the carrier wave functions and has a considerable impact on the NOR coefficient. These findings provide important information for the construction of high-performance, tunable THz optoelectronic devices by demonstrating effective external and structural tuning of NOR. Full article

This study was designed to assess the effectiveness of neonatal congenital adrenal hyperplasia (CAH) screening in Guangzhou, China. A total of 818,417 newborns were screened for CAH by measuring 17-hydroxyprogesterone (17-OHP) concentrations. Cut-off values were stratified based on gestational age (GA) and the timing of sample collection. Neonates with initial positive results (17-OHP ≥ cut-off value) were recalled for a second dried blood spot sample to reassess 17-OHP levels. Confirmatory testing involved biochemical analyses, Sanger sequencing, and multiplex ligation-dependent probe amplification of the CYP21A2 gene. From 2018 to 2024, a total of 40 patients with classical 21-hydroxylase deficiency were identified, including 28 cases (70%) of the salt-wasting form and 12 cases (30%) of the simple virilizing form. The overall incidence of CAH was 1 in 20,653 (95% confidence interval: 1:34,928, 1:14,661). No statistically significant differences in prevalence were observed between sexes or between preterm and full-term infants (p > 0.05). 17-OHP concentrations are influenced by GA and the timing of sample collection. The screening efficiency for CAH could be improved by adopting a multitiered cut-off value system adjusted for GA and collection time. Full article

To meet the demand for online monitoring of acetylene (C₂H₂) in transformer oil, a high-sensitivity detection system based on photoacoustic spectroscopy (PAS) is presented. The system integrates custom-designed modules for signal acquisition, phase-sensitive detection, and data processing, centered around a high-performance microcontroller. A full-wave lock-in amplification-based phase-sensitive detection circuit enables precise extraction of nV-level photoacoustic signals. Finite element simulations of the resonant photoacoustic cell in COMSOL 6.2 were conducted to optimize the structural configuration and sensor placement, achieving maximum acoustic response. Calibration experiments confirmed excellent system performance, demonstrating a linear response (R² > 0.99) over the 0.5–20 ppm range and a practical detection limit of 0.1 ppm. Comparative evaluations against conventional dissolved gas analysis (DGA) equipment verify the system’s sensitivity, stability, and temporal resolution, demonstrating its potential as a high-sensitivity and reliable solution for transformer fault gas diagnostics. Full article

Orthopedic and lower limb fracture surgeries are among the most frequent emergency procedures and are commonly performed under general anesthesia (GA). Background and clinical significance: Epidemiologically, postoperative coma after GA is rare (0.005–0.08%), but delayed awakening (2–4%) and postoperative delirium or postoperative cognitive dysfunction (POCD) (15–40%) remain significant. These neurological complications increase markedly in vulnerable brain patients with psychiatric, cerebrovascular, or neurodegenerative disorders. Methods: This mechanistic narrative review synthesizes evidence from clinical and experimental studies (1990–2025) comparing the effects of general versus Regional (RA)/local (LA) or spinal anesthesia in vulnerable neuropsychiatric populations “with pre-existing brain illness” undergoing orthopedic surgery. Domains analyzed include neuropsychiatric medications effects and interactions with the GA process and with general anesthetic agents, alongside alterations in neurotransmitter modulation, cerebrovascular autoregulation, mitochondrial dysfunction, oxidative stress, redox imbalance, and neuroinflammatory activation. The review summarizes evidence on how the choice of anesthesia type influences postoperative brain outcomes in patients with known neurological conditions. Results: From previous studies, patients with psychiatric and/or chronic brain illness have a 3–5-fold increased risk of delayed emergence and up to 60% incidence of postoperative delirium. Pathophysiological mechanisms involve GABAergic overinhibition, impaired perfusion, mitochondrial energy failure, and inflammatory amplification. Regional/local and spinal anesthesia may offer physiological advantages, preserve cerebral perfusion, and lower neurological complication rates. Conclusions: General anesthesia may exacerbate pre-existing brain vulnerability, converting reversible neural suppression into irreversible dysfunction. Therefore, whenever possible, regional/local or spinal anesthesia with or without sedation should be prioritized in those neurologically vulnerable patients to reduce the length of hospital stay (LOS) and to lower postoperative neurological complications and risks in psychiatric and neurologically unstable patients. Full article

Objectives: Fibroblast growth factor 9 (FGF9), a crucial member of the FGF family, functions as an intercellular signaling molecule involved in angiogenesis, embryogenesis, and tissue repair. Our previous study demonstrated that FGF9 expression in chicken hierarchical granulosa cells (Post-GCs) is regulated by LSD1 Ser54 phosphorylation and that FGF9 promotes cell proliferation. This study aims to analyze the expression and regulation of the FGF9 gene in chicken ovarian follicles and its genetic effect on laying traits in hens. Methods: Chicken FGF9 mRNA expression patterns were examined by real-time quantitative PCR (RT-qPCR). Detection of single nucleotide polymorphisms (SNPs) was performed using PCR amplification and Sanger sequencing. Transcription activity was compared using dual-luciferase reporter assay. Results: Following follicle selection, chicken FGF9 expression significantly decreased in granulosa cells (p < 0.05) while it increased in theca cells (p < 0.05). Hormonal treatments revealed differential regulation; estradiol and FSH downregulated FGF9 in both pre-hierarchical and hierarchical granulosa cells (p < 0.05), whereas progesterone exhibited opposing effects, suppressing expression in pre-hierarchical granulosa cells (Pre-GCs) but stimulating its expression in Post-GCs (p < 0.05). In theca cells, estradiol consistently inhibited FGF9 expression (p < 0.05), while FSH only affected FGF9 expression in pre-hierarchical follicles. Six SNPs in the promoter region (g.−1965G>A, g.−2177G>A, g.−2289G>A, g.−3669A>G, g.−3770A>G, g.−3906G>A) were identified, five of which (g.−1965G>A, g.−2177G>A, g.−2289G>A, g.−3669A>G, g.−3906G>A) showed significant associations with egg production traits. Notably, alleles A (g.−2289), G (g.−3669), and A (g.−3906) enhanced the transcription activity of chicken FGF9 in Pre-GCs. Conclusions: These findings provide novel insights into the expression pattern and regulatory mechanisms of chicken FGF9 during follicular development and identify some genetic markers for egg-laying traits in chickens. Full article

Parahydrogen-induced hyperpolarization (PHIP), introduced nearly four decades ago, provides an elegant solution to one of the fundamental limitations of nuclear magnetic resonance (NMR)—its notoriously low sensitivity. By converting the spin order of parahydrogen into nuclear spin polarization, NMR signals can be boosted by several orders of magnitude. Here we present a portable, compact, and cost-effective setup that brings PHIP and Signal Amplification by Reversible Exchange (SABRE) experiments within easy reach, operating seamlessly across ultra-low-field (0–10 μT) and high-field (>1 T) conditions at 50% parahydrogen enrichment. The system provides precise control over bubbling pressure, temperature, and gas flow, enabling systematic studies of how these parameters shape hyperpolarization performance. Using the benchmark Chloro(1,5-cyclooctadiene)[1,3-bis(2,4,6-trimethylphenyl)imidazole-2-ylidene]iridium(I) (Ir–IMes) catalyst, we explore the catalyst activation time and response to parahydrogen flow and pressure. Polarization transfer experiments from hydrides to [1-¹³C]pyruvate leading to the estimation of heteronuclear J-couplings are also presented. We further demonstrate the use of Chloro(1,5-cyclooctadiene)[1,3-bis(2,6-diisopropylphenyl)imidazolidin-2-ylidene]iridium(I) (Ir–SIPr), a recently introduced catalyst that can also be used for pyruvate hyperpolarization. The proposed design is robust, reproducible, and easy to implement in any laboratory, widening the route to explore and expand the capabilities of parahydrogen-based hyperpolarization. Full article

The limited availability of powerful, tunable, and reliable mid-infrared sources has historically prevented their widespread adoption in spectroscopy applications, even if most greenhouse gases’ fundamental absorption lines are found in this region of the electromagnetic spectrum. However, both mid-infrared fiber lasers and ICLs have enjoyed substantial growth in available output powers in recent years. Since the two technologies have complementary benefits, combining them could prove to be an interesting avenue to explore toward the development of a powerful, easily tunable, and narrow linewidth mid-infrared source. We report what we believe to be the first demonstration of fiber amplification of a distributed feedback interband cascade laser (DFB-ICL) operating in the mid-infrared. The system, based on an in-band pumped dysprosium-doped fluoride fiber amplifier, yields 10 dB of gain and up to 30 mW of output power at 3240 nm. We believe this is an important milestone toward power scaling of single-mode, single-frequency, and rapidly tunable mid-infrared laser sources suitable for advanced gas spectroscopy. Full article

The Indonesian Local Ettawah Goat (ILEG) exhibits substantial genetic variation, suggesting its potential for high productivity and promote sustainable practices in farm animal breeding. This study aimed to investigate the molecular characteristics of prolific ILEG by identifying potential candidate genes through polymerase chain reaction (PCR) analysis of the bone morphogenetic protein receptor type 1B (BMPR1B) gene with two variants: alleles G and A. The research involved PCR amplification and sequencing of the BMPR1B A allele, followed by a combined PCR approach integrating both A and G alleles for genotyping. Blood samples were collected from 73 does with documented prolificacy history and 358 does without prolificacy histories, sourced from seven village breeding operations in East Java. PCR amplification yielded fragments of 556–1181 base pairs in all samples. Haplotype analysis revealed 15 unique haplotypes with a diversity of 0.94 and a mutation frequency of 27.15%. Integration of the BMPR1B alleles G and A revealed polymorphic prolific traits. Polymorphism analysis of 385 ILEGs demonstrated allele frequencies of 0.55 for allele A and 0.45 for the allele G. Average fecundity rates associated with the BMPR1B polymorphism were 1.49 offspring for the homozygous AA, 1.60 for the heterozygous GA, and 1.89 for the homozygous GG. While overall differences among genetic groups were approached statistically significantly (Kruskal–Wallis, p = 0.056), pairwise comparison (Mann–Whitney test) revealed that homozygous GG was significantly associated with higher prolificacy compare to the heterozygous GA (p = 0.029) and homozygous AA (p = 0.040). Similar results were also obtained from data without documented history. These findings suggest that the GG polymorphism of BMPR1B may increase prolificacy in ILEG. Furthermore, the higher frequency of allele G highlights the importance of considering prolificacy traits in breeding selection strategies to enhance sustainable genetic improvement and increase litter size in ILEG. It is recommended to apply dual-primer specific amplification and fragment size differentiation as key molecular approaches for polymorphism of the BMPR1B gene and prolificacy, since these methods can highlight genetic variation and provide valuable markers for breeding programs of the Indonesian Local Etawah Goat. Full article

N-polar GaN HEMT technology has emerged as a disruptive technology that outperforms Ga-polar GaN HEMTs in terms of high-frequency power amplification capability. In this paper, the authors present a comprehensive review of the evolution of N-polar GaN HEMT technology from the perspective of crystal growth, dielectrics, and metals on N-polar GaN, transistor design, and performance. Specifically, the authors discuss the progress of the N-polar GaN HEMTs toward high-frequency, high-power, and high-efficiency applications with recent record-level performances, demonstrated by the authors, at mmWave frequencies. Full article

A new negative-strand RNA virus was identified in grapevines from a 38-year-old ‘Chardonnay’ block in Idaho through high-throughput sequencing (HTS) of total RNA. This virus was tentatively named grapevine-associated cogu-like Idaho virus (GaCLIdV). GaCLIdV has three negative-sense, single-stranded RNA genome segments of ca. 7 kb, 1.9 kb, and 1.3 kb, encoding L protein (RNA-dependent RNA polymerase, RdRP), a movement protein (MP), and a nucleocapsid protein (NC), respectively, identified based on pair-wise comparisons with other cogu- and cogu-like viruses. In phylogenetic analysis based on the RdRP, GaCLIdV grouped within the family Phenuiviridae and was placed in a lineage of plant-infecting phenuiviruses as a sister clade of the genus Laulavirus, clustering most closely with switchgrass phenui-like virus 1 (SgPLV-1) and more distantly related to grapevine-associated cogu-like viruses from the Laulavirus and Coguvirus clades. Both GaCLIdV and SgPhLV-1 are proposed to form a new genus, Switvirus, within the family Phenuiviridae. The presence of GaCLIdV in the original ‘Chardonnay’ samples was confirmed by RT-PCR amplification and Sanger sequencing. This new virus was found in five wine grape cultivars and in six vineyards sampled in Idaho and in Oregon during the 2020–2024 seasons. GaCLIdV may have contributed to the decline observed in the old ‘Chardonnay’ block, although the role of the virus in symptom development awaits further investigation. Full article

Oil and gas pipelines represent critical infrastructure for energy transportation and are essential for ensurin g energy security. The seismic disaster risk assessment of these pipelines is of paramount importance for safeguarding energy supplies. Traditional assessment methodologies primarily focus on the structural integrity of the pipeline body, often neglecting the impact of auxiliary structures and site-specific disaster effects. This study proposes an enhanced risk assessment methodology to address these gaps. This research systematically compiles seismic damage case studies of pipelines from major seismic zones in China. By considering the interactions between auxiliary structure types, site conditions, and forms of disasters, 15 typical operating conditions are identified, and a seismic damage case database is constructed. We develop a failure probability model that integrates geotechnical parameters, structural responses, and ground motion characteristics to assess the impact of liquefaction, site amplification, fault activity, and collapse/landslide phenomena. Utilizing Particle Swarm Optimization (PSO) and Fuzzy Analytic Hierarchy Process (Fuzzy AHP) algorithms, this model quantifies the influence weights and coefficients of these disasters on pipeline auxiliary structures, forming a vulnerability matrix centered around Peak Ground Acceleration (PGA). Additionally, a dual-vulnerability assessment framework is established, and a failure probability formula accounting for the superposition effects of multiple disasters is proposed. This study marks a significant advancement, transitioning from traditional single-pipeline evaluations to “structure-disaster-site” coupling analysis, and provides a scientific basis for pipeline seismic design, operation, and maintenance under specific environmental conditions. This work contributes to the development of quantitative and refined seismic risk assessments for oil and gas pipelines. Full article

In loop-powered 4–20 mA transmitter systems, sensors like temperature, pressure, flow, and gas sensors are chosen based on specific application requirements. These systems are widely adopted in high-precision measurement scenarios, including industrial automation, process control, and environmental monitoring. The transmitter requires a high-performance analog front end (AFE) for precise amplification and signal conditioning. This paper presents a low-noise instrumentation amplifier (IA) for high-precision transmitter front ends, featuring a Successive Approximation Register (SAR)-assisted offset calibration architecture. The proposed structure integrates a chopper current-feedback instrumentation amplifier (CFIA) with an automatic offset calibration loop (AOCL), significantly suppressing internal offset errors and enabling high-accuracy signal acquisition under stringent power and environmental temperature constraints. The designed amplifier provides four selectable gain settings, covering a range from ×32 to ×256. Fabricated in a 0.18 μm CMOS process, the CFIA operates at a 1.8 V supply voltage, consumes a static current of 182 μA, and achieves an input-referred noise as low as 20.28 nV/√Hz at 1 kHz, with a common-mode rejection ratio (CMRR) up to 122 dB and a power-supply rejection ratio (PSRR) up to 117 dB. Experimental results demonstrate that the proposed amplifier exhibits excellent performance in terms of input-referred noise, offset voltage, PSRR, and CMRR, making it well-suited for front-end detection in field instruments that require direct interfacing with measured media. Full article

Microbial symbioses play crucial roles in insect physiology, contributing to nutrition, detoxification, and metabolic adaptations. However, the microbial communities associated with the lac insect Llaveia axin axin, an economically significant species used in traditional lacquer production, remain poorly characterized. In this study, the bacterial diversity and community structure of L. axin axin were investigated using both culture-dependent and culture-independent (metagenomic) approaches, combined with fatty acid profile analysis. The insects were bred at the laboratory level, in controlled conditions, encompassing stages from eggs to adult females. Bacterial strains were isolated from bacteriomes and identified through 16S rRNA gene amplification and genomic fingerprinting through ARDRA analysis. Metagenomic DNA was sequenced using the Illumina MiSeq platform, and fatty acid profiles were determined by gas chromatography–mass spectrometry (GC-MS). A total of 20 bacterial strains were isolated, with Acinetobacter, Moraxella, Pseudomonas, and Staphylococcus detected in first-instar nymphs; Methylobacterium, Microbacterium, and Bacillus in pre-adult females; and Bacillus and Microbacterium in adults. Metagenomic analysis revealed key genera including Sodalis, Blattabacterium, and Candidatus Walczuchella, with Sodalis being predominant in early stages and Blattabacteriaceae in adults. Fatty acid analysis identified palmitic, oleic, linoleic, arachidic, and stearic acids, with stearic acid being the most abundant. These results suggest that dominant bacteria contribute to lipid biosynthesis and metabolic development in L. axin axin. Full article