Search

Emerging evidence has suggested that exposure to PM2.5 is a significant contributing factor to the development of chronic obstructive pulmonary disease (COPD). However, the underlying biological effects and mechanisms of PM2.5 in COPD pathology remain elusive. In this study, we aimed to investigate the implication and regulatory effect of biomass fuels related-PM2.5 (BRPM2.5) concerning the pathological process of fibroblast-to-myofibroblast transition (FMT) in the context of COPD. In vivo experimentation revealed that exposure to biofuel smoke was associated with airway inflammation in rats. After 4 weeks of exposure, there was inflammation in the small airways, but no significant structural changes in the airway walls. However, after 24 weeks, airway remodeling occurred due to increased collagen deposition, myofibroblast proliferation, and tracheal wall thickness. In vitro, cellular immunofluorescence results showed that with stimulation of BRPM2.5 for 72 h, the cell morphology of fibroblasts changed significantly, most of the cells changed from spindle-shaped to star-shaped irregular, α-SMA stress fibers appeared in the cytoplasm and the synthesis of type I collagen increased. The collagen gel contraction experiment showed that the contractility of fibroblasts was enhanced. The expression level of TRPC1 in fibroblasts was increased. Specific siRNA-TRPC1 blocked BRPM2.5-induced FMT and reduced cell contractility. Additionally, specific siRNA-TRPC1 resulted in a decrease in the augment of intracellular Ca2+ concentration ([Ca2+]i) induced by BRPM2.5. Notably, it was found that the PI3K inhibitor, LY294002, inhibited enhancement of AKT phosphorylation level, FMT occurrence, and elevation of TRPC1 protein expression induced by BRPM2.5. The findings indicated that BRPM2.5 is capable of inducing the FMT, with the possibility of mediation by PI3K/AKT/TRPC1. These results hold potential implications for the understanding of the molecular mechanisms involved in BRPM2.5-induced COPD and may aid in the development of novel therapeutic strategies for pathological conditions characterized by fibrosis.

The transmission spectrum of a narrow-band interference filter is crucial and highly influenced by factors such as the temperature and angle, thus requiring precise and online measurements. The traditional method of measuring the transmission spectrum of an interference filter involves the use of a spectrometer, but the accuracy of this method is limited. Moreover, placing a narrow-band interference filter inside a spectrometer hinders real-time online measurements. To address this issue, there is demand for high-precision online spectral testing methods. In response to this demand, we propose and experimentally validate a fine spectral characterization method for narrow-band interference filters. This method uses a narrow-linewidth tunable laser, achieving a spectral resolution in the MHz range for online testing. Two types of narrow-band interference filters were tested using the constructed laser spectroscopy experimental system, obtaining a transmission spectrum with a spectral resolution of 318 MHz. In comparison to spectrometer-based methods, our proposed method demonstrates higher spectral accuracy, enables online measurements, and provides more accurate measurements for special spectral interference filters. This approach has significant application value and promising development prospects.

A prediction system was developed to determine the maximum Rayleigh altitude (MRA) by improving the automated detection of LIDAR power-on conditions and adapting to advancements in middle- and upper-atmosphere LIDAR technology. The proposed system was developed using observational data and nighttime sky imagery collected from multiple LIDAR stations. To assess the accuracy of predictions, three key parameters were employed: mean square error, root mean square error, and mean absolute error. Among the three prediction models created through multivariate regression and autoregressive integrated moving average (ARIMA) analyses, the most suitable model was selected for predicting the MRA. One-month predictions demonstrated the accuracy of the MRA with a maximum error of no more than 5 km and an average error of less than 2 km. This technology has been successfully implemented in numerous LIDAR stations, enhancing their automation capabilities and providing key technical support for large-scale, unmanned, and operational deployments in the middle- and upper-atmosphere LIDAR systems.

Based on the resonance fluorescence scattering mechanism, a narrowband sodium (Na) lidar can measure temperature and wind in the mesosphere and lower thermosphere (MLT) region. By using a narrowband spectral filter, background light noise during the day can be suppressed, allowing for continuous observations. To obtain full-diurnal-cycle temperature and wind measurement results, a complex and precise retrieval process is required, along with necessary corrections to minimize measurement errors. This paper introduces the design of a data acquisition unit for three frequencies in three directions of the Na lidar system in the Chinese Meridian Project (Phase II) and investigates the calibration and retrieval methods for obtaining diurnal temperature and horizontal wind in the MLT region, using a Na Doppler lidar with Faraday anomalous dispersion optical filter (FADOF). Furthermore, these methods are applied to observations conducted by a Na lidar in Beijing, China. The wind and temperature results over full diurnal cycles obtained from the all-solid-state Na Doppler lidar are reported for the first time and compared with temperature measurements from satellite, as well as wind observations from a meteor radar. The comparison demonstrates a reasonable agreement between the results, indicating the rationality of the lidar-retrieved results and the feasibility and effectiveness of the data correction and retrieval method.

As a green technology, constructed wetlands (CWs) can provide a low-cost solution for wastewater treatment. Either as a standalone treatment or integrated with conventional treatment, nutrients, antibiotic resistant bacteria (ARB)/antibiotic resistance genes (ARGs) can be removed by CW efficiently. While, few studies have focused on characteristics of resistome and bacterial community (BC) structure in CW during dormant period. Therefore, in this study, Annan CW (a full-scale hybrid CW) was selected to characterize resistome and BC during dormant period. The profiles of bacteria / ARGs were monitored in combination of shotgun sequencing and metagenomic assembly analysis. And multidrug ARGs are the most abundant in Annan CW, and surface flow wetland had the relatively high ARG diversity and abundance compared with subsurface flow wetland and the front pond. The most dominant phylum in CW is Proteobacteria, while the other dominant phylum in three parts have different order. COD, TP, TN, ARGs, and mobile genetic genes (MGEs) were removed by subsurface flow CW with better performance, but virulent factors (VFs) were removed by surface flow CW with better performance. Based on the spatiotemporal distribution of ARGs, the internal mechanism of ARGs dynamic variation was explored by the redundancy analysis (RDA) and variation partitioning analysis (VPA). BCs, MGEs and environmental factors (EFs) were responsible for 45.6 %, 28.3 % and 15.4 % of the ARGs variations. Among these factors, BCs and MGEs were the major co-drivers impacting the ARG profile, and EFs indirectly influence the ARG profile. This study illustrates the specific functions of ARG risk elimination in different CW components, promotes a better understanding of the efficiency of CWs for the reduction of ARG and ARB, contributing to improve the removal performance of constructed wetlands. And provide management advice to further optimize the operation of CWs during dormant period.

The concentrations of Cu, Zn, As, Pb, Cr, and Cd in soil were analyzed in a mining area in the Inner Mongolia Autonomous Region, China. The average metal concentrations in the soil samples were 204.07 mg/kg, 88.15 mg/kg, 14.47 mg/kg 88.52 mg/kg, 56.45 mg/kg, and 0.235 mg/kg, respectively. Based on the evaluation standards, background values of the soil heavy metals, multiple soil pollution assessment indices, such as the single factor index (Pi), the geological accumulation index (Igeo), the Nemerow index (Pn), the ecological risk index (ER), and the health risk index (HI) were applied to evaluate the soil environmental risks in the study area. It was found that in different soil layer depths (0–10 cm, 10–30 cm, and 30–50 cm), the evaluation result of each index showed that there were significant spatial differences in soil pollution levels, and the focus of different indices differed greatly from each other. The Pi put 18.14% of the area at high risk of soil contamination levels, due to the fact that this index highlights the Cu pollution factor more than other indices and relatively amplifies hazards in some high-risk areas. While the Pn indicated that 61.36% of the study area was at a safe level of soil contamination, it can underestimate the regional soil heavy metal pollution risk. In order to scientifically carry out soil-pollution-risk prevention and control, it is necessary to comprehensively compare and analyze the information disclosed by different indices.

A field trial was conducted in Inner Mongolia to evaluate the stabilization effects of phyto-stabilization, biochar-stabilization, and their coupled stabilization for As, Cu, Pb, and Zn in soil. Stabilization plants (Achnatherum splendens, Puccinellia chinampoensis, and Chinese small iris) and biochar (wood charcoals and chelator-modified biochar) were introduced in the field trial. The acid-extractable fraction and residual fraction of the elements were extracted following a three-stage modified procedure to assess the stabilization effect. The results after 60 days showed that the coupled stabilization produced a better stabilization effect than biochar-/phyto- stabilization alone. Achnatherum splendens and Puccinellia chinampoensis were found to activate the target elements: the residual fraction proportion of As, Cu, Pb, and Zn decreased while the acid-extractable fraction proportion of Cu and Zn increased in the corresponding planting area. Neither type of biochar produced a notable stabilization effect. The residual fraction proportion of As (20.8–84.0%, 29.2–82%), Pb (31.6–39.3%, 32.1–48.9%), and Zn (30.0–36.2%, 30.1–41.4%) increased, while the acid-extractable fraction proportion remained nearly unchanged after treatment using Chinese small iris-straw biochar or Achnatherum splendens-straw biochar, respectively. The results indicate that phyto-stabilization or biochar-stabilization alone are not suitable, whereas the coupled stabilization approach is a more efficient choice.

Nitrogen dioxide (NO2) absorption correction of the sulfur dioxide (SO2) camera was demonstrated for the first time. The key to improving the measurement accuracy is to combine a differential optical absorption spectroscopy (DOAS) instrument with the SO2 camera for the real-time NO2 absorption correction and aerosol scattering correction. This method performs NO2 absorption correction by the correlation between the NO2 column density measurement of the DOAS and the NO2 optical depth of the corresponding channel from the SO2 camera at a narrow wavelength window around 310 and 310 nm. The error of correction method is estimated through comparison with only using the second channel of the traditional SO2 camera to correct for aerosol scattering and it can be reduced by 11.3% after NO2 absorption corrections. We validate the correction method through experiments and demonstrate it to be of greatly improved accuracy. The result shows that the ultraviolet (UV) SO2 camera system with NO2 absorption corrections appears to have great application prospects as a technology for visualized real-time monitoring of SO2 emissions.

Equipped with a 1-meter Cassegrain telescope with 6.2 meter focal length and an electronically gated Intensified Charge-Coupled Device (ICCD), a multilayer Na imager is designed and developed at Wuhan in China. This novel instrument has successfully achieved the first preliminary 3-D image of the mesospheric Sodium (Na) layer when running alongside a Na lidar. The vertical Na layer profile is measured by the lidar, while the horizontal structure of the layer at different altitudes is measured by the ICCD imaging with a horizontal resolution of ~3.7 urad. In this experiment, controlled by the delay and width of the ICCD gating signal, the images of the layer are taken with three-second temporal resolution for every 5 km. The results show highly variable structures in both the vertical and horizontal directions within the Na layer. Horizontal images of the Na layer at different altitudes near both the permanent layer (80–100 km) and a sporadic Na layer at 117.5 km are obtained simultaneously for the first time. The Na number density profiles measured by the lidar and those derived from this imaging technique show excellent agreement, demonstrating the success of this observational technique and the first 3-D imaging of the mesospheric Na layer.

A broadly tunable single-mode quantum cascade laser operating around 5.2 μm has been used to study the high-resolution and broadband mid-IR Zeeman spectrum of Gas-phase 14N16O. The Zeeman spectrum signals in the R (from R0.5 to R22.5), Q (from Q0.5 to Q6.5) and P (from P1.5 to P14.5) branches of the fundamental vibrational transition, have been recorded with both large spectral region (over the range of 1824 –1947 cm−1) and high spectral resolution (<0.001 cm−1) for the first time. We simulated the patterns of magnetic Zeeman split lines in the R, Q, and P branches, and calculated the Landé g-factor of the and components for pure Hund’s coupling case (a) and (b), and intermediate coupling (a–b) case. The experimental Zeeman spectrum measured at various values of magnetic field strength (from 0.04 to 0.32 T) at conditions of both and was calibrated by a 101.6 mm long solid germanium etalon with a free spectral range (FSR) of 0.012 cm−1. Good agreement between the calculated Landé g-factors using Radford’s theory and their best fit values inferred from the experimental data was obtained, which suggests that the Landé g-factor in Hund’s coupling case (a–b) is a better approximation, either at higher rotational quantum numbers, or at lower rotational levels, for both and subsystems. Our results provide a more general evidence to determine the coupling case of NO than previously available, because we can measure and simulate the high-resolution and broadband mid-IR Zeeman spectrum for both low and high rotational levels of the two subsystems. [ABSTRACT FROM AUTHOR]