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The pulsed power switch serves as a critical component in pulsed power systems. The electric radiation generated by switching operations threatens the miniaturization of pulsed power systems, causing significant electromagnetic interference (EMI) to nearby signal circuits. The pseudospark switch’s (PSS) exceptionally fast transient response, a key enabler for sophisticated pulsed power systems, is also a major source of severe EMI. This study investigated the electric field radiation from a high voltage PSS within a capacitor discharge unit (CDU), using a near-field scanning system based on an electro-optic probe. The time-frequency distribution of the radiation was characterized, identifying contributions from three sequential stages: the application of the trigger voltage, the main gap breakdown, and the subsequent oscillating high voltage. During the high-frequency oscillation stage, the distribution of the peak electric field radiation aligns with the predictions of the dipole model, with a maximum value of 43.99 kV/m measured near the PSS. The spectral composition extended to 60 MHz, featuring a primary component at 1.24 MHz and distinct harmonics at 20.14 MHz and 32.33 MHz. Additionally, the impacts of circuit parameters and trigger current on the radiated fields were discussed. These results provided essential guidance for the electromagnetic compatibility (EMC) design of highly-integrated pulsed power systems, facilitating more reliable PSS applications.

In this study, the improvement effect of fiber-reinforced EPS (expanded polystyrene) granular lightweight soil was systematically investigated to address roadbed issues caused by severe cold climatic conditions, specifically, extremely low temperature of -20 °C and an average freezing depth of 92 cm—in Chaoyang City. The test results demonstrate that the use of lime as a curing agent significantly enhances the material’s performance while reducing overall cost. Standard compaction tests revealed a negative correlation between the dry density of the lightweight soil and the EPS content, with values ranging from 1.53 to 1.90 g/cm³. Unconfined compressive strength tests showed a decrease in strength with increasing EPS content; however, the incorporation of polypropylene fibers effectively compensated for this strength loss, achieving a peak compressive strength of 1.93 MPa. Freeze-thaw cycle tests (-18℃ to 20℃) confirmed the material’s excellent frost resistance, with significantly reduced strength loss and stabilized mass loss after multiple cycles. SEM analysis revealed a three–phase synergistic reinforcement mechanism characterized by “particle dispersion - fiber homogeneity - cementation reinforcement”. In this mechanism, the closed pore structure formed by EPS particles, the fiber network, and lime cementation products collectively enhances the internal stability of the material. Based on these findings, optimizing the mix proportions achieves a synergistic balance of lightweight, high strength, and frost resistance, providing an effective solution for roadbed engineering in cold regions.

This research aimed to analyze the volatile compounds emitted during the proliferation of Klebsiella pneumoniae ( K. pneumoniae ) in the laboratory setting using gas chromatography-ion mobility spectrometry (GC-IMS) and to investigate the potential of volatile metabolomics for detecting carbapenemase-producing strains of K. pneumoniae . The volatile metabolomics of K. pneumoniae were comprehensively analyzed using GC-IMS in tryptic soy broth (TSB) as the culture medium. Afterward, the growth stabilization period (T2) served as the primary time point for analysis, with the introduction of imipenem and carbapenemase inhibitors (avibactam sodium or EDTA) during the exponential growth phase (T0) to further investigate alterations in volatile molecules associated with K. pneumoniae . Standard strains were utilized as references, while clinical strains were employed for validation purposes. At T2, a total of 22 volatile organic compounds (VOCs) associated with K. pneumoniae were identified (3 VOCs found in both monomer and dimer forms). Significant differences in VOCs were observed between carbapenemase-negative and carbapenemase-positive strains, both standard and clinical, following the introduction of imipenem. Furthermore, the addition of avibactam sodium led to distinct changes in the VOC content of strains producing class A carbapenemase, while the addition of EDTA resulted in specific alterations in the volatile metabolic profiles of strains producing class B carbapenemase. GC-IMS demonstrated significant promise for analyzing bacterial volatile metabolomics, and its application in evaluating the volatolomics of K. pneumoniae may facilitate the timely detection of carbapenemase-producing strains.

This study aimed to determine the predictive value of aryl hydrocarbon receptor (AHR) signaling pathway genes, and to detect the mediating effect of AHR that may mediate the influence of polycyclic aromatic hydrocarbons (PAHs) on missed abortion. The present study was conducted using a 1:2 matched case-control study, a total of 94 cases of women with missed abortion and 188 matched women controls with normal pregnancy but voluntarily abortion were included. The receiver operating characteristic curve (ROC) and the area under the ROC curve (AUC) were used to evaluate the predictive value of AHR signaling pathway genes for missed abortion. The mediating role of AHR within the effect pathway between PAHs exposure and missed abortion was performed using the mediation package of the R language. The results showed that the level of PAH-DNA adducts in the case group (487.61 ± 6.29) pg/ml was higher than that in the control group (446.86 ± 5.95) pg/ml ( P  < 0.001). There were significant differences in the expression levels of AHR, aryl hydrocarbon receptor nuclear translocator (ARNT), aryl hydrocarbon receptor repressor (AHRR), cytochrome P450 enzymes 1A1 (CYP1A1) and glutathione S-transferase P1 (GSTP1) genes between the case group and the control group ( P  < 0.01). After adjusting for covariates, high exposure of PAH-DNA adducts levels increased AHR and CYP1A1 expression. The 5-fold cross-validation results revealed that the mean value of the area under the ROC curve (AUC) of AHR-ARNT-CYP1A1 axis was 0.931 (95% CI : 0.858 ~ 0.999), which had good predictive performance in assessing the risk of prevalence of missed abortion. AHR gene might play a partial mediating effect in the association between PAHs exposure and missed abortion, and the percentage of mediating effect was 36.56%.

This study presents a 2-D lidar odometry based on an ICP (iterative closest point) variant used in a simple and straightforward platform that achieves real-time and low-drift performance. With a designated multi-scale feature extraction procedure, the lidar cloud information can be utilized at multiple levels and the speed of data association can be accelerated according to the multi-scale data structure, thereby achieving robust feature extraction and fast scan-matching algorithms. First, on a large scale, the lidar point cloud data are classified according to the curvature into two parts: smooth collection and rough collection. Then, on a small scale, noise and unstable points in the smooth or rough collection are filtered, and edge points and corner points are extracted. Then, the proposed tangent-vector-pairs based on edge and corner points are applied to evaluate the rotation term, which is significant for producing a stable solution in motion estimation. We compare our performance with two excellent open-source SLAM algorithms, Cartographer and Hector SLAM, using collected and open-access datasets in structured indoor environments. The results indicate that our method can achieve better accuracy.

Background Dicranostigma leptopodum (Maxim.) Fedde is a perennial herb with bright yellow flowers, well known as \"Hongmao Cao\" for its medicinal properties, and is an excellent early spring flower used in urban greening. However, its molecular genomic information remains largely unknown. Here, we sequenced and analyzed the chloroplast genome of D. leptopodum to discover its genome structure, organization, and phylogenomic position within the subfamily Papaveroideae. Results The chloroplast genome size of D. leptopodum was 162,942 bp, and D. leptopodum exhibited a characteristic circular quadripartite structure, with a large single-copy (LSC) region (87,565 bp), a small single-copy (SSC) region (18,759 bp) and a pair of inverted repeat (IR) regions (28,309 bp). The D. leptopodum chloroplast genome encoded 113 genes, including 79 protein-coding genes, 30 tRNA genes, and four rRNA genes. The dynamics of the genome structures, genes, IR contraction and expansion, long repeats, and single sequence repeats exhibited similarities, with slight differences observed among the eight Papaveroideae species. In addition, seven interspace regions and three coding genes displayed highly variable divergence, signifying their potential to serve as molecular markers for phylogenetic and species identification studies. Molecular evolution analyses indicated that most of the genes were undergoing purifying selection. Phylogenetic analyses revealed that D. leptopodum formed a clade with the tribe Chelidonieae. Conclusions Our study provides detailed information on the D. leptopodum chloroplast genome, expanding the available genomic resources that may be used for future evolution and genetic diversity studies.

Drought is a natural disaster with severe global agricultural and economic impacts. Accurate drought indices are needed for improved assessment and monitoring; however, most existing drought indices poorly represent agricultural drought due to complex interactions among meteorological factors, crop and soil conditions. Here, we compute an integrated drought condition index (IDCI) based on the 3-month standardized precipitation evapotranspiration index (SPEI3), vegetation cover index (VCI) and soil moisture condition index (SMCI). We apply the IDCI to monitoring agricultural drought in Xinjiang, China. After regional evaluations with soil moisture, precipitation and air temperature observations, as well as with the scaled crop yields index, the IDCI was used to describe spatiotemporal changes in regional drought in Xinjiang during 2000–2018, revealing adverse impacts on crop yield (beet, wheat and vegetables). The IDCI is strongly correlated with observed soil moisture and performs better than SMCI, VCI or SPEI3, demonstrating that the IDCI is suitable for agricultural drought monitoring. The most severe drought occurred in the spring to autumn of 2008. Droughts before 2008 were more serious than those after 2008, in terms of both severity and frequency. Droughts in northern, southern and eastern Xinjiang, as well as in the Tianshan Mountains, were generally increasing before 2008 and then weakened after 2008.

Excessive exposure to ultraviolet B (UVB) radiation induces oxidative stress and inflammatory responses, accelerating the senescence process of skin cells. Vorinostat (SAHA), a histone deacetylase inhibitor (HDACi), is typically administered to patients with peripheral T-cell lymphoma, cutaneous T-cell lymphoma, or multiple myeloma. However, its effect on UVB-induced skin photoaging remains unclear. In this study, we used UVB to induce senescence in human immortalized keratinocyte cell line (HaCaT cells) and skin photoaging in Balb/c mice to investigate the potential of SAHA in mitigating photoaging. First, we established a UVB-induced photoaging model in HaCaT cells. We observed that UVB exposure significantly upregulated the activity of senescence-associated β-galactosidase, p16, p21, IL-1β, IL-6, and matrix metalloproteinases [collagenase (MMP-1), matrix metalloproteinase-3 (MMP-3), and gelatinase (MMP-9)]. Supplementation with SAHA effectively alleviated cellular senescence in HaCaT cells. Next, we used UVB to induce photoaging in Balb/c mouse skin. The study demonstrated that UVB markedly caused skin senescence in Balb/c mice, while SAHA effectively mitigated the changes induced by UVB irradiation. Mechanistically, we found that UVB activated the mammalian target of rapamycin (mTOR) and nuclear factor-κB (NF-κB) signaling pathways, whereas SAHA inhibited the upregulation of both mTOR and NF-κB. In summary, these findings suggest that SAHA may protect against UVB-induced cellular senescence and skin photoaging by inhibiting the mTOR and NF-κB signaling pathways. Therefore, SAHA could be a potential anti-senescence agent for mitigating skin photoaging.

This retrospective study aimed to identify the clinical features and prognostic determinants in intensive care unit (ICU) patients with carbapenem-resistant (CRAB) bloodstream infection (BSI) and to establish a personalized risk prediction model. This retrospective cohort study included 185 ICU patients with CRAB-BSI at a tertiary care hospital between 2013 and 2023. Based on 30-day outcomes, patients were categorized into survival and non-survival groups. Independent risk factors for mortality were identified through univariate and multivariate logistic regression analyses. These factors were used to construct a nomogram prediction model. Model performance was evaluated by assessing discrimination using the area under the receiver operating characteristic curve with a calibration plot, and clinical utility via decision curve analysis. The 30-day mortality rate among ICU patients with CRAB-BSI was 60.0%. Multivariate analysis revealed that age [odds ratio (OR) = 1.04, 95% confidence interval (CI): 1.02-1.07], impaired consciousness (OR = 5.10, 95% CI: 2.27-11.45), prior corticosteroid use (OR = 5.82, 95% CI: 2.10-16.12), Sequential Organ Failure Assessment (SOFA) score (OR = 1.26, 95% CI: 1.12-1.42), and C-reactive protein (CRP) level (OR = 1.01, 95% CI: 1.01-1.02) were independent risk factors for 30-day mortality. A nomogram incorporating these variables achieved an area under the curve (AUROC) of 0.863 for predicting 30-day mortality risk. The calibration curve indicated excellent concordance between predictions and observed outcomes, and decision curve analysis demonstrated significant clinical net benefit over a wide range of probability thresholds. Mortality is high in ICU patients with CRAB-BSI and is significantly associated with age, impaired consciousness, corticosteroid use, SOFA score, and CRP level. The developed nomogram exhibits strong predictive accuracy and may function as a practical tool for quantitative management decisions.

BackgroundSecondary infection is an important factor affecting mortality and quality of life in patients with severe acute pancreatitis. The characteristics of secondary infection, which are well known to clinicians, need to be re-examined in detail, and their understanding among clinicians needs to be updated accordingly.AimThis study aims to investigate the characteristics and drug resistance of pathogens causing severe acute pancreatitis (SAP) secondary infection, to objectively present infection situation, and to provide reference for improved clinical management.MethodsA retrospective analysis was performed on 55 consecutive patients with SAP who developed secondary infection with an accurate evidence of bacterial/fungal culture from 2016 to 2018. The statistics included the spectrum and distribution of pathogens, the drug resistance of main pathogens, and associations between multiple infectious parameters and mortality.ResultsA total of 181 strains of pathogens were isolated from (peri)pancreas; bloodstream; and respiratory, urinary, and biliary systems in 55 patients. The strains included 98 g-negative bacteria, 58 g-positive bacteria, and 25 fungi. Bloodstream infection (36.5%) was the most frequent infectious complication, followed by (peri)pancreatic infection (32.0%). Acinetobacter baumannii, Pseudomonas aeruginosa, Klebsiella pneumoniae, Escherichia coli, and Stenotrophomonas maltophilia were predominant among gram-negative bacteria. Gram-positive bacterial infections were mainly caused by Enterococcus faecium and Staphylococcus spp. Fungal infections were predominantly caused by Candida spp. The drug resistance of pathogens causing SAP secondary infection was generally higher than the surveillance level. Patients in the death group were older (55 ± 13 years vs. 46 ± 14 years; p = 0.039) and had longer intensive care unit (ICU) stay (14 vs. 8; p = 0.026) than those in the survival group. A. baumannii infection (68.4% vs. 33%; p = 0.013), number of pathogens ≥ 4 (10 vs. 6; p = 0.005), pancreatic infection (14 vs. 15, p = 0.024), and urinary infection (8 vs. 5; p = 0.019) were significantly associated with mortality.ConclusionGram-negative bacteria are the main pathogens causing SAP secondary infection, in which nosocomial infections play a major role. The drug resistance profile of gram-negative bacteria is seriously threatening, and the commonly used antibiotics in SAP are gradually losing their effectiveness. Much attention should be paid to the rational use of antibiotics, and strategies should be established for infection prevention in SAP.