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[Display omitted] • In situ characterization of liquid and solid phase parameters of colloidal droplets. • Retrieve inclusion concentration and size from dual wavelength rainbow extinction. • Maximum size measurement error of 55 nm is achievable when inclusion size is 530 nm. • Measurement limits of the technique, affected by multiple factors, are discussed. Considerable interest and demand exists in multi-parameter characterization of colloidal droplets. However, an optical in-situ characterization of such droplets is a particular challenge due to its heterogeneous and multi-scale nature, motivating the investigation of a dual-wavelength extinction rainbow refractometry. An analytical model is proposed, in which dual-wavelength extinction effect of the inclusions on the amplitude of the primary rainbow peak allows measurement of inclusion concentration and particle size. The rainbow pattern itself yields the refractive index and diameter of the host droplet. Validation experiments using deionized monodisperse water droplets containing standard polystyrene nanoparticles with different concentrations (0%, 0.1%, 0.2%, 0.3%) and particle sizes (210 nm, 530 nm) were conducted. Measured refractive indices and droplet diameters agree well with the known values. Measurement errors of inclusion concentration and size were analyzed with and without a prior knowledge of the inclusion size. Measurement limits of this approach are also discussed. [ABSTRACT FROM AUTHOR]

• Utilizing phase-shifted long-period fiber grating (PS-LPFG) to optimize output spectral linewidth of high-power fiber laser. • A detailed design philosophy and method of PS-LPFG was proposed, according to the characteristics of spectrum broadening. • The PS-LPFG was fabricated by point-by-point scanning technique and dual annealing method. • Alleviating the deterioration of laser spectral linewidth caused by nonlinear effect. • Suitable for continuous-wave and pulsed fiber lasers with different structures. Suppressing nonlinear effects in fiber laser by special fiber gratings has attracted growing attentions. Currently, most researches mainly focus on suppressing stimulated Raman scattering. However, the mitigation of the nonlinear effects, such as self-phase modulation or four wave mixing, which broaden the main lobe of the output laser spectrum has not been paid attention. We report a novel method for universally and conveniently optimizing output spectral linewidth of fiber laser by applying phase-shifted long-period fiber grating (PS-LPFG). A detailed design philosophy and method of PS-LPFG was proposed. Further, a symmetrical PS-LPFG was fabricated to verify the feasibility of the method. The central wavelength of the grating's passband was designed to match the signal light of a 1075 nm fiber laser. A 200 W continuous-wave oscillator was also established to evaluate the PS-LPFG's performance. Experimental results demonstrate that the spectral broadening of the main lobe is clearly alleviated. The 30 dB linewidth of the evaluation system is narrowed approximately 32.9% by the PS-LPFG. The 0.03 dB insertion loss of the fabricated grating avoids the deterioration of the signal laser's power. Furthermore, the 0.023 °C/W thermal slope of the grating allows for potential applications in higher power fiber lasers. [ABSTRACT FROM AUTHOR]

Ammonia (NH 3) is an important base gas in the atmosphere and has received extensive research interest due to its role on secondary aerosol formation. However, the effects of NH 3 on the photochemical smog oxidants formation including ozone and secondary aerosol did not attract much attention. In this study, a set of smog chamber experiments was conducted under toluene/NOx photo-oxidation base condition and adding NH 3 in the following photochemical regimes referred as hydrocarbon, NOx-limited and transitional regimes. Dedicated instruments including gas analysers, scanning mobility particle sizer (SMPS), aerosol mass spectrometry (HR-ToF-AMS) were used to measure the gaseous compounds, aerosol mass concentration and chemical composition. It was found that the presence of NH 3 did not affect the O 3 formation rate. However, the particle number concentration increased dramatically after NH 3 was injected in any photochemical regimes. This effect has been mainly attributed to the rapid formation of organic ammonium and ammonium nitrate. The mass spectra of organic aerosols from AMS showed that the most abundant fragments were at m/z 28, 29, 43 and 44, which became higher after the addition of NH 3 in the transition and NOx-limited regimes, indicating that NH 3 could enhance the formation of the compounds containing carbonyl and carboxylic acid functional groups. Compared to hydrocarbon-limited regime, higher atomic nitrogen-to-carbon (N:C) ratios were observed when NH 3 were injected into transition and NOx-limited regimes, and this is mainly due to more organic nitrate formation. Four factors, which were assigned to inorganic nitrate aerosols, carboxylic acid compounds, carbonyl compounds and N-containing organic compounds (NOC), were identified and interpreted by applying the positive matrix factorization (PMF) to the AMS dataset. These results provide new insights into the complex chemistry of toluene/NOx/NH 3 during different O 3 formation regimes, and imply the benefit of controlling NH 3 to mitigate PM 2.5 when O 3 formation is under VOC-limited regime. [Display omitted] • How NH 3 affects particle formation in different photochemical regimes was investigated. • NH 3 does not affect O 3 formation but affect particle formation and composition. • Higher O:C and N:C were observed after NH 3 injection in NOx-limited regime. • Four factors contributing to the secondary aerosols were identified by PMF analysis. [ABSTRACT FROM AUTHOR]

Droplet formation and evaporation are key processes of spray combustion, the mechanism of which is yet not fully understood. In this study, we develop a method based on high-speed (25 kHz) digital off-axis holography (DOH) to visualize and measure burning ethanol droplets in the atomization. Ligaments and fragments from a burning drop internally blown to disintegrate are studied after hologram processing. Reconstructed images are nearly free from influences of the flame with the measured droplets showing clear borders. Size and depth location uncertainties reduce to nearly 1/10 of those of commonly used with digital in-line holography. A time-resolved observation shows the dynamic formation of secondary droplets with stages classified as vapor penetration, sheet breakup, and ligament disintegration. Sizes and velocities of fragments are extracted and their distributions are analyzed at 1.12 ms, 3.12 ms, and 13 ms after the initiation of atomization. Results show that new secondary droplets have larger sizes and smaller velocities with time. Lagrangian measurements are performed with 3D droplet tracking algorithm. Evaporation rates of 31 droplets with different positions, sizes, and velocities are obtained and the results are in good accordance with previous studies. The DOH technique is promising to investigate the combustion of individual fuel droplets in a polydisperse droplet cloud as the real spray combustion. [ABSTRACT FROM AUTHOR]

The size and morphology of irregular particles are essential parameters for a variety of industrial processes. The backward interferometric speckle imaging technique can be applied to measure the relevant parameters of opaque irregular particles. To verify the accuracy of the backward interferometric speckle imaging technique, an elaborately designed experimental system was used to combine a backward interferometric speckle imaging system with a digital inline holography (DIH) system to characterise the same pulverised coal particles for quantitative comparison. The results of the backward interferometric speckle imaging were in good agreement with those of DIH in terms of particle size and morphology. In the backward interferometric speckle imaging system, the laser illumination and recording system are configured on the same side, and therefore only one window is required during measurement. This facilitates its instrument integration and provides significant potential for industrial applications involving powder processing. • Backward interferometric speckle imaging and DIH is applied to measure irregular particle. • The accuracy of backward interferometric speckle imaging for irregular particle is quantified. • Backward ISI with laser illumination and recording at one side in facilitates instrumentation. [ABSTRACT FROM AUTHOR]

• Phase critical angle scattering (PCAS) is applied to bubble size and growth measurement. • The PCAS technique is validated by numerical simulation. • The accuracy of size and growth measurement with PCAS is evaluated. Simultaneous measurement of bubble size and its transient growth is of great importance for the study of bubble dynamics. Current methods based on Lagrangian tracking strategy cannot resolve nanoscale bubble growth within a short time interval. We have developed phase critical angle scattering (PCAS) and the theoretical derivation reveals the capability of PCAS to realize it. Nine air bubble cases are simulated based on a Lorenz-Mie scattering algorithm, and the results show that PCAS technique has a high resolution in size variation down to several nanometers and high accuracy with errors within 9%. Then the PCAS technique is applied to measure single growing bubble generated by electrolysis. By comparing the size measurement reults with results of the microscopic imaging, the size measurement accuracy of PCAS is evaluated to be around 7%. The PCAS technique has great potential in the characterization of bubble-like particle dynamics. [ABSTRACT FROM AUTHOR]

• Picosecond pulsed digital off-axis holography visualize a kerosene swirl spray. • Droplet size, shape and 3D position are measured clearly in near nozzle region. • 3D spatial number and SMD distributions of spray field are statistically analyzed. Near-nozzle spray formation determines the spray structure of downstream dilute spray, and thus plays an important role in evaluating the performance of air blast atomizer. To capture the exact structure of the atomization field in near-nozzle region, the spray cones from the exit of a two-stage swirler to the 9 mm downstream area with the gas pressure of 0.5 kPa, 1.0 kPa, 3.0 kPa and the fuel pressure of 0.03 MPa and 0.71 MPa, are investigated using a picosecond pulsed laser digital off-axis holography (DOH) system. The spray structures and droplet characteristics in near-nozzle region are visualized with clear image of nonspherical droplets and then quantified. Semi-spray cone angles from the front view (x - y) projections of particle fields are obtained and results indicate that the angle increases with the increase of gas pressure within test range. From the overall view of spray field, the droplet peak diameter decreases with gas pressure, from about 80 μm at 0.54 kPa to about 30 μm at 3.05 kPa. In addition, cumulative volume distribution of droplet obtained in near-nozzle region agrees well with modified Rosin–Rammler distribution. From the local view, spatial distributions of the normalized droplet number density and Sauter mean diameters (SMD) ranging from 30 μm to 480 μm of the swirl spray field are statistically analyzed. Results indicate that as the gas pressure increases, the SMD distribution is more uniform. Under all gas pressure conditions, SMD distributions tend to be larger in the near-exit area and the region inside mist cone edge. The work also demonstrates that picosecond pulsed DOH is a powerful tool for 3D diagnostics of spray. [ABSTRACT FROM AUTHOR]

A field campaign was carried out during May–September of 2018 at three sites in Hangzhou, representing residential (ZH), industrial (XS), and natural (HZHP) areas, respectively. The characteristics of precursors to ozone (O 3) - volatile organic compounds (VOCs) and nitrogen (NOx) - revealed observably diversities among the three sites. A 0-D atmospheric box model contained the Master Chemical Mechanism (MCMv3.3.1) was implemented to study the O 3 -precursor sensitivity and O 3 in-situ photochemical processing. The discussion of relative incremental reactivity (RIR) showed that O 3 production at HZHP was mostly limited by both VOCs and NOx, while ZH and XS were generally identified as VOC-limited regime. More specifically, ethene, m -xylene, and toluene had the largest contributing to O 3 production in Hangzhou. The simulated mixing ratios of hydroxyl radical (OH) were within same level among ZH, XS and HZHP, while the simulated mixing ratios of hydroperoxyl radical (HO 2) at HZHP were much higher than the other two sites, indicating the different cyclic processes between OH and HO 2 among the three sites. Modellings for various emission reduction scenarios were conducted, and the results implied that different strategies were needed for different areas in order to efficiently reduce O 3 pollution. For example, the abatement ratio of anthropogenic VOCs (AVOCs) to NOx mixing ratios should be higher than 1.6 and 2.5 at ZH and XS, respectively, while we should target on reducing NOx instead of AVOCs at HZHP. The obtained results provide policy relevant guidance on understanding the photochemical pollution through fundamental chemical mechanism, and can assist local governments (Hangzhou) in taking effective control strategies to deal with O 3 pollution. • 0-D box model with MCMv3.3.1 was applied to investigate the summertime O 3 formation mechanism at three sites of Hangzhou. • The photochemical regimes of the three sites were identified through relative incremental reactivity (RIR) analysis. • Ethene, toluene, and m -xylene were identified as the most sensitive anthropogenic VOC species to O 3 formation in Hangzhou. • Modellings for reduction scenarios were conducted, and different ozone control strategies were developed for each area. [ABSTRACT FROM AUTHOR]

• A compact phase rainbow refractometer (PRR) with larger measurement volume. • The resolution in measuring change in droplet diameter using PRR is quantified. • Direct measurement of transient evaporation rate of droplets in a droplet stream. • Interaction droplets on the evaporation rate is quantified. • A refined correlation for evaporation of droplets in a droplet stream is presented. Quantifying the evaporation rate of droplets is of great importance in many applications and this is especially true if the evaporation occurs in a rapidly changing environment, such that models describing evaporation under steady state conditions are no longer valid. To achieve such information from experiments, the phase rainbow refractometry (PRR) technique has recently be shown to be capable of simultaneously measuring temperature, size, and size variation at the nanometer scale, quantities essential for quantifying transient evaporation rates. The present study examines the use of the PRR technique to characterize the evaporation of monodispersed droplets in a droplet stream injected into ambient air. This is combined with high-speed microscopic shadowgraphy, yielding as measured quantities droplet diameter, diameter change, temperature evolution, velocity and computed transient evaporation rate of the droplet stream. The accuracy and resolution of the measurements are evaluated by comparison with theoretical values and values measured with alternative means. Furthermore, the results are used to investigate how the evaporation rate is modified by interaction among droplets in the droplet stream and how these rates differ from evaporation rates predicted for isolated droplets, using the well proven Abramzon and Sirignano model. Finally, the evaporation rate, including the influence of droplet interaction, is shown to be in line with correlations suggested by Virepinte; refinement to this correlation is proposed. [ABSTRACT FROM AUTHOR]

Background: Ureteral stricture (US) is a pathological stenosis in the urinary tract characterized by increased collagen synthesis and inflammation. Autophagy activation has been shown to ameliorate tissue fibrosis and protect against fibrotic diseases. Verapamil has beneficial therapeutic benefits on fibrotic disorders. The pharmacological effects of verapamil on fibroblast autophagy in US and the underlying mechanism need to be investigated further., Methods: US patients were recruited to isolate scar tissues, hematoxylin-eosin (HE) and Masson trichrome staining were performed to analyze histopathological changes. The US animal model was established and administered with verapamil (0.05 mg/kg) in the drinking water. Transforming growth factor (TGF)-β1 was adopted to facilitate collagen synthesis in fibroblasts. The mRNA and protein expressions were examined by qRT-PCR, western blot, immunofluorescence and immunohistochemistry. ELISA was adopted to measure interleukin (IL)-1β and IL-6 levels. Molecular interaction experiments like dual luciferase reporter and chromatin immunoprecipitation (ChIP) assays were performed to analyze the interaction between signal transducers and activators of transcription 3 (STAT3) and RNA polymerase II associated factor 1 (PAF1)., Results: Herein, our results revealed that verapamil activated TGF-β1-treated fibroblast autophagy and inhibited inflammation and fibrosis by repressing Ca 2+ ⁄calmodulin-dependent protein kinase II (CaMK II) δ-mediated STAT3 activation. Our following tests revealed that STAT3 activated PAF1 transcription. PAF1 upregulation abrogated the regulatory effect of verapamil on fibroblast autophagy and fibrosis during US progression. Finally, verapamil mitigated US in vivo by activating fibroblast autophagy., Conclusion: Taken together, verapamil activated TGF-β1-treated fibroblast autophagy and inhibited fibrosis by repressing the CaMK IIδ/STAT3/PAF1 axis.

The Letter delves into an approach to holographic image denoising, drawing inspiration from the generative paradigm. It introduces a conditional diffusion model framework that effectively suppresses twin-image noises and speckle noises in dense particle fields with a large depth of field (DOF). Specific training and inference configurations are meticulously outlined. For evaluation, the method is tested using calibration dot board data and droplet field data, encompassing gel atomization captured via inline holography and aviation kerosene swirl spray through off-axis holography. The performance is assessed using three distinct metrics. The metric outcomes, along with representative examples, robustly demonstrate its superior noise reduction, detail preservation, and generalization capabilities when compared to two other methods. The proposed method not only pioneers the field of generative holographic image denoising but also highlights its potential for industrial applications, given its reduced dependency on high-quality training labels.

We propose a new, to the best of our knowledge, rainbow technique called three-dimensional rainbow refractometry (TDRR), with a cylindrical lens in the signal collecting system. With a TDRR model based on the ray transfer matrix developed, it is proved that the tilt angle of the rainbow signal is related to the axial position of the droplet, which helps to obtain the 3D position. By converting rainbow scattering angle calibration into the system parameter calibration, a new rainbow data processing program is written in combination with the model to obtain the refractive index and the particle size. With TDRR, we measured a monodisperse droplet stream of deionized water at room temperature for experimental validation and obtained the refractive index with an absolute error of less than 0.0015, the droplet size with an error within ±5%, and the axial position with an error within ±3%, which demonstrated a high accuracy of TDRR.

Background: Bladder cancer (BCa) is the most frequent type of cancer in humans. The association between m6A modification and the anti-tumor effects of natural killer (NK) cells has been described in BCa. This study intended to investigate the implications of m6A regulators in modulating SYTL1 expression in BCa and the association with the anti-tumor effects of NK cells., Methods: The prognostic role of SYTL1 in BCa was investigated using bioinformatics analysis, and the correlation between SYTL1 expression and NK cells was analyzed. The effects of SYTL1 on the anti-tumor response of NK-92 cells were examined by RT-qPCR, cytotoxicity, western blot, and ELISA assays. The relationships among WTAP, YTHDF2, and SYTL1 were investigated by RT-qPCR, RIP-qPCR, ELISA, and actinomycin D treatment. Finally, the effects of WTAP and SYTL1 on BCa tumor growth and the anti-tumor response of NK cells were verified in vivo ., Results: SYTL1 was reduced in BCa tissues and had a prognostic significance, which was related to NK cell-mediated anti-tumor responses. NK-92 cells produced toxicity to BCa cells, which was further enhanced by SYTL1 overexpression in BCa cells through prompting LDH, NKG2D, NKp30, and NKp44 and IFN-γ levels. WTAP enhanced the degradation of the SYTL1 mRNA by YTHDF2. WTAP and YTHDF2 impaired the anti-tumor response of NK cells in BCa. SYTL1 inhibited the BCa progression in mice while enhancing the anti-tumor response of NK cells., Conclusions: WTAP inhibited the anti-tumor response of NK cells to BCa cells by promoting the degradation of SYTL1 mRNA through YTHDF2-mediated m6A methylation., (©The Author(s) 2024. Open Access. This article is licensed under a Creative Commons CC-BY International License.)

Industrial development is an essential foundation of the national economy, but the industry is also the largest source of air pollution, of which power plants, iron and steel, building materials, and other industries emit large amounts of pollutants. Therefore, the Chinese government has promulgated a series of stringent emission regulations, and it is against this backdrop that research into air pollution control technologies for key industrial sectors is in full swing. In particular, during the 13th Five-Year Plan, breakthroughs have been made in pollution control technology for key industrial sectors. A multi-pollutant treatment technology system of desulfurization, denitrification, and dust collection, which applies to key industries such as power plants, steel, and building materials, has been developed. High-performance materials for the treatment of different pollutants, such as denitrification catalysts and desulfurization absorbers, were developed. At the same time, multi-pollutant synergistic removal technologies for flue gas in various industries have also become a hot research topic, with important breakthroughs in the synergistic removal of NO x , SO x , and Hg. Due to the increasingly stringent emission standards and regulations in China, there is still a need to work on the development of multi-pollutant synergistic technologies and further research and development of synergistic abatement technologies for CO 2 to meet the requirements of ultra-low emissions in industrial sectors., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022. Published by Elsevier B.V.)

ETS transcription factor (ELK1) stimulates the expression of genes at the onset of the cell cycle and participates in early developmental programming. Here, we investigated whether alterations of ELK1 lead to progression of bladder cancer (BCa), a main neoplasm of urinary tract, and clarified the function of ELK1 in BCa. Using the GEO database, we identified ELK1 as the most significantly overexpressed gene in BCa, which was substantiated in the acquired clinical samples and cells. Silencing of ELK1 inhibited the malignant phenotype of BCa cells. Further analysis revealed that ELK1 synergized with histone deacetylase 2 (HDAC2) to specifically bind to the synaptotagmin like 1 (SYTL1) promoter, thereby repressing SYTL1 transcription and protein expression. Depletion of SYTL1 reversed the repressive effects of ELK1 depletion on the malignant phenotype of BCa cells. Our in vitro findings were reproduced in vivo on a nude mouse tumorigenic model. Together, our results reveal that ELK1, through suppression of SYTL1 via HDAC2, supports the malignant phenotype of BCa cells., (© 2022. The Author(s) under exclusive licence to Japan Human Cell Society.)

Background: Ureteral stricture (US) is a fibrotic process that leads to urinary tract obstruction and even kidney damage, with the characteristic of reduced extracellular matrix (ECM) degradation and increased collagen synthesis. Verapamil, as a calcium channel blocker, was reported to prevent scar formation. Our work aimed to investigate the biological effects and mechanism of verapamil in US., Methods: Fibroblasts were subjected to transforming growth factor-beta 1 (TGF-β1) to stimulate collagen synthesis, and the messenger ribonucleic acid (mRNA) and protein expressions in fibroblasts were assessed using quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. The location of phosphorylation-signal transducer and activator of transcription 3 (p-STAT3) and Jund proto-oncogene subunit (JunD) in fibroblasts were determined by immunofluorescence (IF). The binding relationship between signal transducer and activator of transcription 3 (STAT3) and collagen type I alpha1 (COL1A1)/collagen type III alpha 1 chain (COL3A1) and the binding relationship between JunD and tissue inhibitor of metalloproteinases-1 (TIMP-1) were verified by dual luciferase reporter gene and chromatin Immunoprecipitation (ChIP) assays., Results: Herein, we found that verapamil could inhibit TGF-β1/Ca2 + ⁄calmodulin-dependent protein kinase II (CaMK II)-mediated STAT3 activation in fibroblasts, and STAT3 inhibition repressed collagen production. In addition, verapamil could inhibit TGF-β1/CaMK II-mediated Mothers against DPP homolog 3 (Smad3)/JunD pathway activation in fibroblasts, and JunD silencing inhibited TIMP1 (a matrix metalloproteinase inhibitor) expression. Our subsequent experiments revealed that STAT3 bound with COL1A1 promoter and COL3A1 promoter and activated their transcription, and JunD bound with TIMP1 promoter and activated its transcription. Moreover, as expected, STAT3 activation could eliminate the inhibitory effect of verapamil treatment on TGF-β1-induced collagen production in fibroblasts, and JunD overexpression reversed the inhibitory effect of verapamil treatment on TGF-β1-induced TIMP1 expression in fibroblasts., Conclusion: Verapamil inhibited collagen production and TIMP-1 expression in US by blocking CaMK II-mediated STAT3 and Smad3/JunD pathways., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Under the extensive implementation of ultra-low emission facilities, sulfur trioxide (SO 3 ) has received increasing attention. This article reviews the measurement techniques for SO 3 in flue gas, which include controlled condensation method (CCM), isopropanol absorption method (IPA), salt method, tunable diode laser absorption spectroscopy (TDLAS), ultraviolet absorption spectroscopy (UVs), and Fourier transform infrared spectroscopy (FTIR). The first three methods are chemical methods, which focus on the extraction of SO 3 from flue gas. With highly reactive nature and relatively low concentrations, which are about 5 mg/m 3 even lower, achieving high-fidelity flue gas sampling and non-destructive extraction of SO 3 is the key to SO 3 measurement. The latter three methods belong to spectroscopic methods, which focus on the principle, system composition, and influencing factor analysis. With real-time response and 1-ppm detection limit, attention is attracted to spectroscopic methods on online measurement. This article comprehensively introduces the measurement techniques for SO 3 concentration in flue gas and presents conclusions so as to enable researchers to decide the direction of further investigation.

Atomization of low temperature fuel is of great importance in a jet engine combustor, and its visualization and diagnostics are challenging, especially in the presence of shreds and ligaments. A 25 kHz picosecond pulsed digital inline holography system is applied to measure the spray produced by an airblast atomizer with low temperature kerosene. The breakup process of shreds and ligaments of -37 ∘ C kerosene are visualized and analyzed, revealing the transition of liquid jet disintegrating into droplets under the atomizing air film. Three-dimensional positions and size distributions of droplets in spray are acquired. It is found that a decrease in the kerosene temperature increases shreds and ligaments in the spray, which eventually leads to reduction of droplet density and increase of droplet size, while increasing the air pressure can compensate the degradation. This work also demonstrates that high speed holographic imaging is a powerful tool in spray diagnostics and liquid breakup visualization.

Haze formation involves many interacting factors, such as secondary aerosol formation, unfavourable synoptic conditions and regional transport. The interaction between these factors complicates scientific understanding of the mechanism behind haze formation. In this study, we investigated the factors resulting in haze events in Longyou, a city located in a basin in China. Aerosol samples of PM 2.5 were collected for subsequent chemical composition analysis between 11 January and 5 February 2018. The impacts of wind on PM 2.5 , SO 2 and NO 2 concentrations were analysed. Besides, the origin of air parcels and potential sources of PM 2.5 were analysed by backward trajectory, potential source contribution function (PSCF) and concentration-weighted trajectories (CWT). Among the water-soluble ions identified, NO 3 - had the highest concentration, with further analysis demonstrating the haze evolution was mainly driven by the reactions involving NO 3 - formation. The dramatic increase of nitrate is mainly due to the homogeneous reaction of nitric acid with ammonia, while sulfate is likely due to heterogeneous reactions of NO 2 , SO 2 and NH 3 . The average wind speed was less than 2 m/s during the aerosol sampling period, which could be considered as a stagnant state. Pollutants emitted by industrial area located in the northeast Longyou were probably brought to observation sites by continuous wind from northeast and accumulated gradually. Air parcels originating from the northeast of Zhejiang province also had large effects on haze pollution in Longyou. Together, our results showed that rapid secondary aerosol formation and unfavourable synoptic conditions are the main factors resulting in haze pollution in Longyou., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

During the 2016 Hangzhou G20 Summit, the chemical composition of submicron particles (PM 1 ) was measured by a High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) along with a suite of collocated instruments. The campaign was undertaken between August 5 and September 23, 2016. The impacts of emission controls and meteorological conditions on PM 1 chemical composition, diurnal cycles, organic aerosol (OA) source apportionment, size distribution and elemental ratios were characterized in detail. Excluding rainy days, the mean PM 1 mass concentration during G20 was 30.3 μg/m 3 , similar to that observed before G20 (28.6 μg/m 3 ), but much lower than that after G20 (42.7 μg/m 3 ). The aerosol chemistry during the three periods was substantially different. Before G20, high PM 1 loading mostly occurred at daytime, with OA accounting for 60.1% of PM 1 , followed by sulfate (15.6%) and ammonium (9.1%). During G20, the OA fraction decreased from 60.1% to 44.6%, whereas secondary inorganic aerosol (SIA) increased from 31.8% to 49.5%. After G20, SIA dominated high PM 1 loading, especially at nighttime. Further analysis showed that the nighttime regional transport might play an unfavorable role in the slight increase of secondary PM 1 during G20, while the strict emissions controls were implemented. The OA (O/C = 0.58) during G20 was more aged, 48.7% and 13.7% higher than that before and after G20 respectively. Our study highlighted that the emission controls during G20 were of great success in lowering locally produced aerosol and pollutants, despite of co-existence of nighttime regional transport containing aerosol high in low-volatile organics and sulfate. It was implied that not only are emissions controls on both local and regional scale important, but that the transport of pollutants needs to be sufficiently well accounted for, to ensure the successful implementation of air pollution mitigation campaigns in China., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Objective: To investigate the cytochrome P450 2E1 (CYP2E1) RsaI/PstI and DraI polymorphisms in workers exposed to benzene., Methods: A cross-sectional survey was carried out. A total of 71 workers exposed to benzene were included in observation group and the same number of people without occupational benzene exposure were included in control group. Blood samples from the two groups were collected and genotyping for CYP2E1 RsaI/PstI and DraI were conducted using the polymerase chain reaction-restriction fragment length polymorphism., Results: There were no significant differences in CYP2E1 DraI genotype and allele distributions between the observation group and the control group (χ² = 2.374, P > 0.05; χ² = 2.113, P > 0.05). Significant differences in CYP2E1 RsaI/PstI genotype and allele distributions between the two groups were observed (χ² = 9.129, P < 0.01; χ² = 6.028, P < 0.05)., Conclusion: Mutations at CYP2E1 RsaI/PstI can enhance the expression of CYP2E1 and this suggests individuals with the mutated gene have increased susceptibility to chronic benzene poisoning.

The holographic microscopy technique is a strong contender for dynamic three-dimensional (3D) measurement of small particles (typically smaller than 5 microm) in microchannels. However, there is a big challenge to accurately measure the size of such small particles. The traditional hologram reconstruction method was numerically investigated. It is found that the error level, especially for the size measurement, is higher than expected, even in an ideal situation without consideration of noise. An alternative way based on Lorenz-Mie (LM) calculations was then presented. The intensity distribution of the fringe pattern on the particle hologram is directly used and compared with the ones calculated using an LM-based program. Various cases for particle sizes from 0.5 to 5 microm and recording distances from 5 to 500 microm are tested. The results show that the accuracy in particle sizing can be significantly improved.