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Understanding the near-ground vertical and temporal photochemical O3 formation mechanism is important to mitigate O3 pollution. Here, we measured the vertical profiles of O3 and its precursors at six different heights, ranging from 5 to 335 m, using a newly built vertical observation system in the Pearl River Delta (PRD) region of China. The net photochemical ozone production rate (P(O3)net) and O3 formation sensitivities at various heights were diagnosed using an observation-based model coupled with the Master Chemical Mechanism (MCM v3.3.1). Moreover, to assess model performance and identify the causative factors behind O3 pollution episodes, the P(O3)net was measured at 5 m above ground level with a custom-built detection system. In total, three O3 pollution episodes and two non-episodes were captured. The identified O3 pollution episodes were found to be jointly influenced by both photochemical production and physical transport, with local photochemical reactions playing a major role. The high index of agreement (IOA) calculated by comparing the modelled and measured P(O3)net values indicated the rationality of investigating the vertical and temporal variability in O3 formation mechanisms using model results. However, the measured P(O3)net values were generally higher than the modelled P(O3)net values, particularly under high-NOx conditions, which may indicate a potential underestimation of total RO2 by the model. Throughout the measurement period, the contribution of different reaction pathways to O3 production remained consistent across various heights, with HO2 + NO as the major O3 production pathway, followed by RO2 + NO. We observed that P(O3)net decreased with an increase in measurement height, which was primarily attributed to the reduction in O3 precursors, such as oxygenated volatile organic compounds (OVOCs) and non-methane hydrocarbons (NMHCs). The O3 formation regimes were similar at different heights during both episodes and non-episodes, either being located in the VOC-sensitive regime or in the transition regime that is more sensitive to VOCs. Diurnally, photochemical O3 formation typically remained in the VOC-sensitive regime during the morning and noon, but it transitioned to the transition regime and was more sensitive to VOCs in the afternoon at around 16:00 LT (local time). Vertical and temporal photochemical O3 formation is most sensitive to OVOCs, suggesting that targeting specific VOCs for control measures is more practical and feasible at the observation site. The vertical temporal analysis of O3 formation mechanisms near the ground surface in this study provides critical foundational knowledge that can be used to formulate effective short-term emergency and long-term control strategies to combat O3 pollution in the PRD region of China.

Stiffness excitation is one of the important excitations for the variable hyperbolic circular-arc-tooth-trace (VH-CATT) cylindrical gear system. Accurate calculation of the gear meshing stiffness is of great significance to investigating dynamic characteristics of the VH-CATT cylindrical gear system. Firstly, based on the forming theory of the modified tooth surface, the modified tooth surface equation of the VH-CATT cylindrical gear was deduced, and the 3D reconstruction was realised. Next, the load tooth contact analysis (LTCA) model of the VH-CATT cylindrical gear was developed to calculate the meshing stiffness of the VH-CATT cylindrical gear, and it was verified by the finite-element calculation. Finally, the influence of the load and modification parameters on the VH-CATT cylindrical gear stiffness was investigated. Research shows that the stiffness calculation method of the VH-CATT cylindrical gear based on LTCA is accurate. The meshing stiffness of the VH-CATT cylindrical gear in the double-tooth meshing area is large, and the meshing stiffness of the VH-CATT cylindrical gear in the single-tooth meshing area is small. The stiffness of the VH-CATT cylindrical gear increases with an increase in the load and cutter inclination angle, the stiffness of the VH-CATT cylindrical gear only in the double-tooth meshing area decreases with an increase in the parabolic coefficient, and the stiffness of the VH-CATT cylindrical gear increases with a decrease in the blade parabolic vertex position value. The research results provide a basis for improving the bearing capacity of the VH-CATT cylindrical gear and optimising design.

While aqueous-phase processing is known to contribute to the formation of nitrogen-containing organic compounds (NOCs), the specific pathways involved remain poorly understood. In this study, we aimed to characterize the NOCs present in both pre-fog aerosols and fog water collected at a suburban site in northern China. Fourier-transform ion cyclotron resonance mass spectrometry was utilized to analyze the molecular composition of NOCs in both negative and positive modes of electrospray ionization (ESI− and ESI+). In both pre-fog aerosols and fog water samples, NOCs constituted a significant portion, accounting for over 60 % of all assigned formulas in ESI− and more than 80 % in ESI+. By comparing the molecular composition of NOCs originating from biomass burning, coal combustion, and vehicle emissions, we identified that 72.3 % of NOCs in pre-fog aerosols were attributed to primary anthropogenic sources (pNOCs), while the remaining NOCs were categorized as secondary NOCs formed within the aerosols (saNOCs). Unique NOCs found in fog water were classified as secondary NOCs formed within the fog water (sfNOCs). Through a comprehensive “precursor–product pair” screening involving 39 reaction pathways, we observed that the nitration reaction, the amine pathway, and the intramolecular N-heterocycle pathway of NH3 addition reactions contributed 43.6 %, 22.1 %, and 11.6 % of saNOCs, respectively. In contrast, these pathways contributed 26.8 %, 28.4 %, and 29.7 % of sfNOCs, respectively. This disparity in formation pathways is likely influenced by the diverse precursors, the aqueous acidity, and the gas-phase species partitioning. Correspondingly, saNOCs were found to contain a higher abundance of carbohydrate-like and highly oxygenated compounds with two nitrogen atoms compared to pNOCs. Conversely, sfNOCs exhibited a higher content of lipid-like compounds with fewer oxygen atoms. These results underscore the distinct secondary processes contributing to the diversity of NOCs in aerosols and fog water, which may lead to their different climate effects.

Single-photon detectors, with their exceptional sensitivity, provide a reliable means for single-photon-level detection, demonstrating significant advantages in detecting weak signals in complex environments compared to traditional detectors. With the continuous advancement in semiconductor manufacturing technology, single-photon detectors based on linear array configurations have emerged and rapidly developed. This study utilizes a linear array single-photon detector in free-running mode combined with a scanning mechanism to design and implement a spectral detection and imaging system. Through the spectral scanning unit, this system successfully achieves precise spectral detection in the 890 nm to 1710 nm range, with a spectral resolution better than 2 nm. Utilizing the imaging scanning unit, the system effectively performs target spectral imaging under single and multiple wavelength conditions at 1064 nm, 1310 nm, and 1520 nm. By optimizing algorithms for data processing, the system can achieve rapid and accurate spectral detection and imaging even under low-light conditions where the average photon count per pixel is less than 3. The results of this study are expected to provide strong technical support for the application of spectral imaging technology in the field of high-speed detection and imaging.

Installation errors are important factor for the contact performance of the variable hyperbolic circular arc tooth trace (VH-CATT) cylindrical gear; the study of the relationship between installation errors and contact performances is beneficial for gear vibration and noise reduction. Firstly, based on the meshing theory, the tooth surface equation and contact ellipse of the VH-CATT cylindrical gear were deduced, and the tooth surface imprinting experiment was realized. Next, the tooth contact analysis model of the VH-CATT cylindrical gear was developed to investigate the influence of the installation errors on the elliptical contact area. Then, the calculation formulas of the tooth surface gap and contact point flexibility matrix were carried out to develop the load tooth contact analysis model of the VH-CATT cylindrical gear. Finally, the influence of the installation errors on the load distribution was investigated. Research shows that the elliptical contact area of the VH-CATT cylindrical gear is a line contact within a certain range and is located in the middle section of the tooth width. The elliptical contact area of the VH-CATT cylindrical gear increases or decreases rapidly when meshing in and out, and all the installation errors have a certain influence on the elliptical contact area, except for the center distance error. The single-tooth meshing area with the installation errors is greater than that of the ideal gear pair. The load distribution area with the installation errors deviates from the middle section, except for the center distance error. The installation rotation errors around the x and y axis have a certain influence on the maximum load of the single-tooth meshing area. The research results provide a basis for improving the bearing capacity of the VH-CATT cylindrical gear and optimizing the design.

The boundary layer's separation loss in compressor cascades constitutes a significant portion of profile loss, critically influencing aerodynamic performance optimization and control. This study employs Large Eddy Simulation (LES) to examine separation losses at varying attack angles, focusing on a rectangular compressor cascade. Specifically, it explores the long separation bubble at a 45% blade height cross-section under designed incidence. Analysis of the separation bubble's transition process revealed a notable surge in total pressure loss rate prior to transition, which stabilized following reattachment. The study thoroughly investigates the evolution of long bubbles, employing quadrant analysis of Reynolds stress, critical point theory, and an in-depth examination of individual vortex dynamics. The findings indicate that the peak of cross-flow within the separation bubble acts as the primary mechanism initiating the transition. This insight is corroborated by DNS calculations of natural transitions on flat plates. Building upon these findings, the study discusses the effects of varying attack angles on transition processes. Notably, increased incidence prompted the upstream migration of the long separation bubble, transforming it into a short bubble at the leading edge. This shift led to a fivefold increase in separation loss and doubled the frequency of transverse flow fluctuations.

This study analyzes the evolution of single-proton states within the odd-A isotopes of 117−133Sb. We identified the monopole force interaction between the πg7/2 and νh11/2 orbitals as the key driver of the ground-state inversion observed in 121Sb. Moreover, we provide an additional asset for this monopole force by investigating the negative-parity states in 132Sb and demonstrating its manifestation through a comparative assessment of πg-νh multiplets. Our results provide conclusive evidence, for the first time, explaining the ground-state inversion in 121Sb through observations in 132Sb. The increasing occupation and configurations of the orbit πd5/2 revealed that the single-proton property of state 5/2+ remained robust even in the neutron mid-shell region.

High-resolution models have become widely available for the study of the ocean's small-scale processes. Although these models simulate more turbulent ocean dynamics and reduce uncertainties of parameterizations, they are not practical for long-term simulations, especially for climate studies. Besides scientific research, there are also growing needs from key applications for multi-resolution, flexible modeling capabilities. In this study we introduce the Ocean Modeling with Adaptive REsolution (OMARE), which is based on refactoring Nucleus for European Modelling of the Ocean (NEMO) with the parallel computing framework of JASMIN (J parallel Adaptive Structured Mesh applications INfrastructure). OMARE supports adaptive mesh refinement (AMR) for the simulation of the multi-scale ocean processes with improved computability. We construct an idealized, double-gyre test case, which simulates a western-boundary current system with seasonally changing atmospheric forcings. This paper (Part 1) focuses on the ocean physics simulated by OMARE at two refinement scenarios: (1) 0.5–0.1∘ static refinement and the transition from laminar to turbulent, eddy-rich ocean, and (2) the short-term 0.1–0.02∘ AMR experiments, which focus on submesoscale processes. Specifically, for the first scenario, we show that the ocean dynamics on the refined, 0.1∘ region is sensitive to the choice of refinement region within the low-resolution, 0.5∘ basin. Furthermore, for the refinement to 0.02∘, we adopt refinement criteria for AMR based on surface velocity and vorticity. Results show that temporally changing features at the ocean's mesoscale, as well as submesoscale process and its seasonality, are captured well through AMR. Related topics and future plans of OMARE, including the upscaling of small-scale processes with AMR, are further discussed for further oceanography studies and applications.

Water-soluble humic-like substances (HULIS) absorb light in near-UV and visible wavelengths and exert significant influence on the atmospheric environment and climate. However, knowledge on HULIS evolution during haze bloom-decay process is limited. Herein, PM2.5 samples were obtained during a winter haze event in Guangzhou, China, and the light absorption and molecular composition of HULIS were investigated by UV–Vis spectrophotometry and ultrahigh-resolution mass spectrometry. Compared with HULIS on clean days, the absorption coefficients (Abs365) of HULIS on haze days were significantly higher but the mass absorption efficiencies (MAE365) were relatively low, suggesting diverse and dynamic absorption properties of HULIS during haze episodes. The CHO and CHON compounds were the most abundant components in HULIS, followed by CHOS, CHONS, and CHN. Haze HULIS presented comparatively high molecular weight; a lower aromaticity index (AImod); and higher O/Cw, O/Nw, and O/Sw ratios, indicating that HULIS fractions undergo relatively high oxidation during haze days compared to clean days. Moreover, CHON and CHO compounds with high AImod were the major potential chromophores in HULIS and significantly contributed to HULIS light absorption. It is worth noting that the proportions of these chromophores decreased during haze events, mainly owing to their higher oxidation during haze episodes. Besides, accumulated contribution of organic compounds emitted from vehicles and formed from reactions of biogenic volatile organic compounds (bio-VOCs) also diluted light-absorbing compounds in haze HULIS. These findings help us to understand HULIS evolution during haze bloom-decay processes in the subtropic region of China.

The roundness error is the main geometric characteristic parameter of shaft and hole parts. Evaluation accuracy is an important indicator of the quality inspection technology. Existing roundness error evaluation methods are insufficient in terms of the calculation amount, convergence speed, and calculation accuracy. This study proposes a novel roundness error evaluation method based on improved bee colony algorithm to evaluate the roundness error of shaft and hole parts. Population initialization and search mechanism were considered for the optimal design to improve the convergence precision of the algorithm. The population was initialized in the local search domain defined by the contour data. The roughness error was obtained by the convergence solution of the circle center calculated iteratively by the step-decreasing method. The roundness error was also evaluated by taking the same set of image domain data as an example to verify the feasibility of the proposed method. The algorithm exhibited higher accuracy than that traditional methods and thus can be widely used to evaluate the roundness error of shaft and hole parts.

The surface radiation budget, also known as all-wave net radiation (Rn), is a key parameter for various land surface processes including hydrological, ecological, agricultural, and biogeochemical processes. Satellite data can be effectively used to estimate Rn, but existing satellite products have coarse spatial resolutions and limited temporal coverage. In this study, a point-surface matching estimation (PSME) method is proposed to estimate surface Rn using a residual convolutional neural network (RCNN) integrating spatially adjacent information to improve the accuracy of retrievals. A global high-resolution (0.05∘), long-term (1981–2019), and daily mean Rn product was subsequently generated from Advanced Very High Resolution Radiometer (AVHRR) data. Specifically, the RCNN was employed to establish a nonlinear relationship between globally distributed ground measurements from 522 sites and AVHRR top-of-atmosphere (TOA) observations. Extended triplet collocation (ETC) technology was applied to address the spatial-scale mismatch issue resulting from the low spatial support of ground measurements within the AVHRR footprint by selecting reliable sites for model training. The overall independent validation results show that the generated AVHRR Rn product is highly accurate, with R2, root-mean-square error (RMSE), and bias of 0.84, 26.77 W m−2 (31.54 %), and 1.16 W m−2 (1.37 %), respectively. Inter-comparisons with three other Rn products, i.e., the 5 km Global Land Surface Satellite (GLASS); the 1∘ Clouds and the Earth's Radiant Energy System (CERES); and the 0.5∘ × 0.625∘ Modern-Era Retrospective analysis for Research and Applications, Version 2 (MERRA-2), illustrate that our AVHRR Rn retrievals have the best accuracy under most of the considered surface and atmospheric conditions, especially thick-cloud or hazy conditions. However, the performance of the model needs to be further improved for the snow/ice cover surface. The spatiotemporal analyses of these four Rn datasets indicate that the AVHRR Rn product reasonably replicates the spatial pattern and temporal evolution trends of Rn observations. The long-term record (1981–2019) of the AVHRR Rn product shows its value in climate change studies. This dataset is freely available at https://doi.org/10.5281/zenodo.5546316 for 1981–2019 (Xu et al., 2021).

Organosulfur compounds (OrgSs), especially organosulfates, have been widely reported to be present in large quantities in particulate organic matter found in various atmospheric environments. Despite hundreds of organosulfates and their formation mechanisms being previously identified, a large fraction of OrgSs remain unexplained at the molecular level, and a better understanding of their formation pathways and critical environmental parameters is required to explain the variations in their concentrations. In this study, the abundance and molecular composition of OrgSs in fine particulate samples collected in Guangzhou were reported. The results revealed that the ratio of the annual average mass of organic sulfur to total particulate sulfur was 33 ± 12 %, and organic sulfur had positive correlations with SO2 (r=0.37, p) and oxidant (NOx + O3, r=0.40, p). A Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) analysis revealed that more than 80 % of the sulfur-containing formulas detected in the samples had the elemental composition of o/(4s+3n)≥1, indicating that they were largely in the form of oxidized organosulfates or nitrooxy organosulfates. Many OrgSs that were previously tentatively identified as having biogenic or anthropogenic origins were also present in freshly emitted aerosols derived from combustion sources. The results indicated that the formation of OrgSs through an epoxide intermediate pathway could account for up to 46 % of OrgSs from an upper bound estimation, and the oxidant levels could explain 20 % of the variation in the mass of organic sulfur. The analysis of our large dataset of FT-ICR MS results suggested that relative humidity, oxidation of biogenic volatile organic compounds via ozonolysis, and NOx-related nitrooxy organosulfate formation were the major reasons for the molecular variation of OrgSs, possibly highlighting the importance of the acid-catalyzed ring-opening of epoxides, oxidation processes, and heterogeneous reactions involving either the uptake of SO2 or the heterogeneous oxidation of particulate organosulfates into additional unrecognized OrgSs.

The presence of organic sulfur compounds (OS) at the water surface acting as organic surfactants, may influence the air-water interaction and contribute to new particle formation in the atmosphere. However, the impact of ubiquitous anthropogenic pollutant emissions, such as SO2 and polycyclic aromatic hydrocarbons (PAHs) on the formation of OS at the air-water interface still remains unknown. Here, we observe large amounts of OS formation in the presence of SO2, upon irradiation of aqueous solutions containing typical PAHs, such as pyrene (PYR), fluoranthene (FLA), and phenanthrene (PHE) as well as dimethylsulfoxide (DMSO). We observe rapid formation of several gaseous OSs from light-induced heterogeneous reactions of SO2 with either DMSO or a mixture of PAHs and DMSO (PAHs/DMSO), and some of these OSs (e.g. methanesulfonic acid) are well established secondary organic aerosol (SOA) precursors. A myriad of OSs and unsaturated compounds are produced and detected in the aqueous phase. The tentative reaction pathways are supported by theoretical calculations of the Gibbs energy of reactions. Our findings provide new insights into potential sources and formation pathways of OSs occurring at the water (sea, lake, river) surface, that should be considered in future model studies for a better representation of the air-water interaction and SOA formation processes.

Characterizing the molecular composition of cloud water could provide unique insights into aqueous chemistry. Field measurements were conducted at Mt. Tianjing in southern China in May, 2018. There are thousands of formulas (C5–30H4–55O1–15N0–2S0–2) identified in cloud water by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). CHON formulas (formulas containing C, H, O, and N elements; the same is true for CHO and CHOS) represent the dominant component (43.6 %–65.3 % of relative abundance), followed by CHO (13.8 %–52.1%). S-containing formulas constitute ∼5 %–20 % of all assigned formulas. Cloud water has a relative-abundance-weighted average O/C of 0.45–0.56, and the double bond equivalent of 5.10–5.70. Most of the formulas (>85 %) are assigned as aliphatic and olefinic species. No statistical difference in the oxidation state is observed between cloud water and interstitial PM2.5. CHON with aromatic structures are abundant in cloud water, suggesting their enhanced in-cloud formation. Other organics in cloud water are mainly from biomass burning and oxidation of biogenic volatile organic compounds. The cloud water contains more abundant CHON and CHOS at night, which are primarily contributed by −N2O5 function and organosulfates, demonstrating the enhanced formation in dark aqueous or multi-phase reactions. While more abundant CHO is observed during the daytime, likely due to the photochemical oxidation and photolysis of N- or S-containing formulas. The results provide an improved understanding of the in-cloud aqueous-phase reactions.

The intrinsic mechanical and interfacial characteristics of precipitates in Mg–Sn–Y alloys were calculated to predict strengthening precipitates and to design novel Mg alloys. The first-principle calculations results indicated that the Sn3Y5 phase had a higher bulk and shear moduli than the Mg24Y5 and Mg2Sn phases. The Mg/Sn3Y5 interface was more stable and possessed a higher adhesive strength than the Mg/Mg2Sn and Mg/Mg24Y5 interfaces. Four as-cast alloys (S10Y3 (Mg-0.5Sn-0.16Y), S5Y3 (Mg-0.43Sn-0.25Y), S1Y1 (Mg-0.36Sn-0.37Y) and S3Y5 (Mg-0.27Sn-0.48Y) alloy (at.%)) were then designed according to the different Sn to Y atomic ratios (10:3, 5:3, 1:1 and 3:5). The lower Sn to Y atomic ratio promoted the formation of the Sn3Y5 phase in the S3Y5 alloy, whereas the S10Y3 alloy with a higher Sn to Y atomic ratio mainly consisted of the Mg2Sn phase. Compared with the S10Y3 alloy, the yield strength and ultimate tensile strength of the S3Y5 alloy were increased by 70% and 16% without sacrificing the elongation at room temperature, which was greatly improved by 127% and 104% at elevated temperatures simultaneously. These results suggested that the calculations of intrinsic mechanical and interfacial characteristics of precipitates may provide an effective tool to design high-strength Mg alloys.

Volatile organic compounds (VOCs) play important roles in the tropospheric atmosphere. In this study, VOCs were measured at an urban site in Guangzhou, one of the megacities in the Pearl River Delta (PRD), using a gas chromatograph–mass spectrometer/flame ionization detection (GC–MS/FID) and a proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS). Diurnal profile analyses show that stronger chemical removal by OH radicals for more reactive hydrocarbons occurs during the daytime, which is used to estimate the daytime average OH radical concentration. In comparison, diurnal profiles of oxygenated volatile organic compounds (OVOCs) indicate evidence of contributions from secondary formation. Detailed source analyses of OVOCs, using a photochemical age-based parameterization method, suggest important contributions from both primary emissions and secondary formation for measured OVOCs. During the campaign, around 1700 ions were detected in PTR-ToF-MS mass spectra, among which there were 462 ions with noticeable concentrations. VOC signals from these ions are quantified based on the sensitivities of available VOC species. OVOC-related ions dominated PTR-ToF-MS mass spectra, with an average contribution of 73 % ± 9 %. Combining measurements from PTR-ToF-MS and GC–MS/FID, OVOCs contribute 57 % ± 10 % to the total concentration of VOCs. Using concurrent measurements of OH reactivity, OVOCs measured by PTR-ToF-MS contribute greatly to the OH reactivity (19 % ± 10 %). In comparison, hydrocarbons account for 21 % ± 11 % of OH reactivity. Adding up the contributions from inorganic gases (48 % ± 15 %), ∼ 11 % (range of 0 %–19 %) of the OH reactivity remains `missing”, which is well within the combined uncertainties between the measured and calculated OH reactivity. Our results demonstrate the important roles of OVOCs in the emission and evolution budget of VOCs in the urban atmosphere.

Higher alkanes are a major class of intermediate-volatility organic compounds (IVOCs), which have been proposed to be important precursors of secondary organic aerosols (SOA) in the atmosphere. Accurate estimation of SOA from higher alkanes and their oxidation processes in the atmosphere is limited, partially due to the difficulty of their measurement. High-time-resolution (10 s) measurements of higher alkanes were performed using NO+ chemical ionization in proton transfer reaction time-of-flight mass spectrometry (NO+ PTR-ToF-MS) at an urban site in Guangzhou in the Pearl River Delta (PRD) and at a rural site in the North China Plain (NCP). High concentrations were observed in both environments, with significant diurnal variations. At both sites, SOA production from higher alkanes is estimated from their photochemical losses and SOA yields. Higher alkanes account for significant fractions of SOA formation at the two sites, with average contributions of 7.0 % ± 8.0 % in Guangzhou and 9.4 % ± 9.1 % in NCP, which are comparable to or even higher than both single-ring aromatics and naphthalenes. The significant contributions of higher alkanes to SOA formation suggests that they should be explicitly included in current models for SOA formation. Our work also highlights the importance of NO+ PTR-ToF-MS in measuring higher alkanes and quantifying their contributions to SOA formation.

Abstract Background Prurigo nodularis (PN) is a highly pruritic, chronic dermatosis and difficult to treat. PN lesions are characterized by existence of many hyperkeratotic, erosive papules and nodules. However, the pathogenesis of PN still remains unelucidated. Aim To clarify the keratin role in the epidermis hyperproliferation, the keratin expression pattern in the PN lesional skin. Methods In this study, we enrolled 24 patients with PN and 9 healthy control volunteers. K1/K10, K5/K14, K6/K16/K17 expression pattern were investigated by using immunohistochemical staining. Results The lesional skin consists of the thickened spinous layers, in which active cell division was found. K5/K14 were upregulated in PN lesional epidermis, the staining signal localized in the basal layer and lower suprabasal layers. Hyperproliferation‐associated K6 was found in all layers of epidermal lesional skin, especially in the spinous layers. In contrast, K16 was only detected in the basal and lower suprabasal layers, K17 was observed in the basal and spinous layers. Terminal differential keratins K1/K10 were upregulated, detected in the pan‐epidermis, but spared in the basal and low suprabasal layers. Conclusion The keratinocytes enter an alternative differentiation pathway, which are responsible for the activated keratinocyte phenotype, abnormal keratins expression potentially contributes to the keratinocytes proliferation, subsequently lead to increased lesional skin epidermis thickness, hyperkeratiosis and alteration of skin barrier properties.

Unlike the deep understanding of highly oxygenated organic molecules (HOMs) driving continental new particle formation (NPF), little is known about the organic compounds involved in coastal and open-ocean NPF. On the coastline of China we observed intense coastal NPF events initiated by iodine nucleation, but particle growth to cloud condensation nuclei (CCN) sizes was dominated by organic compounds. This article reveals a new group of C18,30HhOoNn and C20,24,28,33HhOo compounds with specific double-bond equivalents and oxygen atom numbers in new sub 20 nm coastal iodine particles by using ultrahigh-resolution Fourier transform–ion cyclotron resonance mass spectrometry (FT-ICR-MS). We proposed these compounds are oxygenated or nitrated products of long-chain unsaturated fatty acids, fatty alcohols, nonprotein amino acids or amino alcohols emitted mutually with iodine from coastal biota or biologically active sea surface. Group contribution method estimated that the addition of –ONO2, –OH and –C=O groups to the precursors reduced their volatility by 2–7 orders of magnitude and thus made their products condensable onto new iodine particles in the coastal atmosphere. Nontarget MS analysis also provided a list of 440 formulas of iodinated organic compounds in size-resolved aerosol samples during the iodine NPF days, which facilitates the understanding of unknown aerosol chemistry of iodine.

Brown carbon (BrC) plays an essential impact on radiative forcing due to its ability to absorb sunlight. In this study, the optical properties and molecular characteristics of water-soluble and methanol-soluble organic carbon (OC; MSOC) emitted from the simulated combustion of biomass and coal fuels and vehicle emissions were investigated using ultraviolet–visible (UV–vis) spectroscopy, excitation–emission matrix (EEM) spectroscopy, and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) coupled with electrospray ionization (ESI). The results showed that these smoke aerosol samples from biomass burning (BB) and coal combustion (CC) had a higher mass absorption efficiency at 365 nm (MAE365) than vehicle emission samples. A stronger MAE365 value was also found in MSOC than water-soluble organic carbon (WSOC), indicating low polar compounds would possess a higher light absorption capacity. Parallel factor (PARAFAC) analysis identified six types of fluorophores (P1–6) in WSOC including two humic-like substances (HULIS-1) (P1 and P6), three protein-like substances (PLOM) (P2, P3, and P5), and one undefined substance (P4). HULIS-1 was mainly from aging vehicle exhaust particles; P2 was only abundant in BB aerosols; P3 was ubiquitous in all tested aerosols; P4 was abundant in fossil burning aerosols; and P5 was more intense in fresh vehicle exhaust particles. The MSOC chromophores (six components; C1–6) exhibited consistent characteristics with WSOC, suggesting the method could be used to indicate the origins of chromophores. FT-ICR mass spectra showed that CHO and CHON were the most abundant components of WSOC, but S-containing compounds appeared in a higher abundance in CC aerosols and vehicle emissions than BB aerosols, while considerably fewer S-containing compounds largely with CHO and CHON were detected in MSOC. The unique formulas of different sources in the van Krevelen (VK) diagram presented different molecular distributions. To be specific, BB aerosols with largely CHO and CHON had a medium H ∕ C and low O ∕ C ratio, while CC aerosols and vehicle emissions largely with S-containing compounds had an opposite H ∕ C and O ∕ C ratio. Moreover, the light absorption capacity of WSOC and MSOC was positively associated with the unsaturation degree and molecular weight in the source aerosols. The above results are potentially applicable to further studies on the EEM-based or molecular-characteristic-based source apportionment of chromophores in atmospheric aerosols.

Leg weakness (LW) issues are a great concern for pig breeding industry. And it also has a serious impact on animal welfare. To dissect the genetic architecture of limb-and-hoof firmness in commercial pigs, a genome-wide association study was conducted on bone mineral density (BMD) in three sow populations, including Duroc, Landrace and Yorkshire. The BMD data were obtained by ultrasound technology from 812 pigs (including Duroc 115, Landrace 243 and Yorkshire 454). In addition, all pigs were genotyped using genome-by-sequencing and a total of 224 162 single-nucleotide polymorphisms (SNPs) were obtained. After quality control, 218 141 SNPs were used for subsequent genome-wide association analysis. Nine significant associations were identified on chromosomes 3, 5, 6, 7, 9, 10, 12 and 18 that passed Bonferroni correction threshold of 0.05/(total SNP numbers). The most significant locus that associated with BMD (P value = 1.92e−14) was detected at approximately 41.7 Mb on SSC6 (SSC stands for Sus scrofa chromosome). CUL7, PTK7, SRF, VEGFA, RHEB, PRKAR1A and TPO that are located near the lead SNP of significant loci were highlighted as functionally plausible candidate genes for sow limb-and-hoof firmness. Moreover, we also applied a new method to measure the BMD data of pigs by ultrasound technology. The results provide an insight into the genetic architecture of LW and can also help to improve animal welfare in pigs.

The Tibetan Plateau (TP) plays a vital role in regional and global climate change. The TP has been undergoing significant surface warming starting from 1850, with an air temperature increase of 1.39 K and surface solar dimming resulting from decreased incident solar radiation. The causes and impacts of solar dimming on surface warming are unclear. In this study, long-term (from 1850 to 2015) surface downward radiation datasets over the TP are developed by integrating 18 Coupled Model Intercomparison Project phase 5 (CMIP5) models and satellite products. The validation results from two ground measurement networks show that the generated downward surface radiation datasets have a higher accuracy than the mean of multiple CMIP5 datasets and the fused datasets of reanalysis and satellite products. After analyzing the generated radiation data with four air temperature datasets, we found that downward shortwave radiation (DSR) remained stable before 1950 and then declined rapidly at a rate of −0.53 W m−2 per decade, and that the fastest decrease in DSR occurs in the southeastern TP. Evidence from site measurements, satellite observations, reanalysis, and model simulations suggested that the TP solar dimming was primarily driven by increased anthropogenic aerosols. The TP solar dimming is stronger in summer, at the same time that the increasing magnitude of the surface air temperature is the smallest. The cooling effect of solar dimming offsets surface warming on the TP by 0.80±0.28 K (48.6±17.3 %) in summer since 1850. It helps us understand the role of anthropogenic aerosols in climate warming and highlights the need for additional studies to be conducted to quantify the influence of air pollution on regional climate change over the TP.

The molecular compositions of polar organic compounds (POCs) in particles emitted from various vessels and excavators were characterized using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), and possible molecular structures of POCs were proposed. POCs were extracted with purified water and sorted by elemental composition into three groups: CHO, CHON, and S-containing compounds (CHONS and CHOS). The results show the following. (i) CHO (accounting for 49 % of total POCs in terms of peak response) was the most abundant group for all tested off-road engines, followed by CHON (33 %) and CHOS (35 %) for diesel and HFO (heavy-fuel-oil)-fueled off-road engines. (ii) The abundance and structure of the CHON group in water extracts were different in terms of engine type and load. The relative peak response of CHON was the highest for excavator emissions in working mode, compared to the idling and moving modes. Furthermore, dinitrophenol and methyl dinitrophenol were potentially the most abundant emission species for high-rated speed excavators, while nitronaphthol and methyl nitronaphthol were more important for low-rated speed vessels. (iii) The composition and structure of the S-containing compounds were directly influenced by fuel oil characteristics (sulfur content and aromatic ring), with more condensed aromatic rings in the S-containing compounds proposed in HFO-fueled vessel emissions. More abundant aliphatic chains were inferred in diesel equipment emissions. Overall, higher fractions of condensed hydrocarbons and aromatic rings in POCs emitted from vessels using HFO cause strong optical absorption capacity. Different structures in POCs could provide a direction for qualitative and quantitative analysis of organic compounds as tracers to distinguish these emissions from diesel or HFO-fueled off-road engines.

Waterlogging limits plant growth and yield. We investigated the effects of waterlogging stress on leaf photosynthesis, chlorophyll fluorescence, antioxidant capacity, chloroplast ultrastructure, and yield of sorghum (Sorghum bicolor L.). Two sorghum cultivars, Jinuoliang01 (JN01, waterlogging-tolerant cultivar) and Jinza31 (JZ31, waterlogging-sensitive cultivar) were subjected to a 12-d waterlogging treatment; the plants of the two cultivars which were not subjected to waterlogging were used as control (CK), respectively. After waterlogging treatment, the yield of JZ31 and JN01 decreased by 72.3 and 52.9%, the net photosynthetic rate of JZ31 and JN01 decreased by 61.8 and 39.0%, respectively, compared with CK. The chlorophyll content was higher, PSII was more stable, and chloroplast structure remained more intact in JN01 than that in JZ31 under waterlogging. This was due to the higher peroxidase and catalase activities and nonphotochemical quenching in JN01 compared to JZ31. Therefore, greater antioxidant capacity and nonphotochemical quenching could alleviate damage to PSII and chloroplast ultrastructure to maintain higher net photosynthetic rate under waterlogging. This may be an important waterlogging-tolerance mechanism of sorghum.

An increased trend in aerosol concentration has been observed in the Himalayas in recent years, but the understanding of the chemical composition and sources of aerosol remains poorly understood. In this study, molecular chemical composition of water-soluble organic matter (WSOM) from two filter samples collected during two high aerosol loading periods (denoted as P1 and P2) at a high-altitude station (Qomolangma Station, QOMS; 4276 m a.s.l.) in the northern Himalayas was identified using electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR MS). More than 4000 molecular formulas were identified in each filter sample which were classified into two compound groups (CHO and CHON) based on their elemental composition, with both accounting for nearly equal contributions in number (45 %–55 %). The relative abundance weighted mole ratio of O∕Cw for P1 and P2 was 0.43 and 0.39, respectively, and the weighted double bond equivalents (DBEw), an index for the saturation of organic molecules, were 7.12 and 7.87, respectively. Although the O∕Cw mole ratio was comparable for CHO and CHON compounds, the DBEw was significantly higher in CHON compounds than CHO compounds. More than 50 % molecular formulas in the Van Krevelen (VK) diagram (H∕C vs. O∕C) were located in 1–1.5 (H∕C) and 0.2–0.6 (O∕C) regions, suggesting potential lignin-like compounds. The distributions of CHO and CHON compounds in the VK diagram, DBE vs. number of C atoms, and other diagnostic diagrams showed high similarities among each other, suggesting their similar source and/or atmospheric processes. Many formulas formed from biogenic volatile organic compounds (e.g., ozonolysis of α-pinene products) and biomass-burning-emitted compounds (e.g., phenolic compounds) were found in the WSOM, suggesting the important contribution of these two sources in the Himalayas. The high DBE and high fraction of nitrogen-containing aerosol can potentially impact aerosol light absorption in this remote region. Further comprehensive study is needed due to the complexity of organic aerosol and limited molecular number identified in this study.

We studied the auto-oscillation spectrum of spin Hall nano-oscillators (SHNO) based on synthetic antiferromagnets (SAFs) by micromagnetic simulations. In our model, Py/Ru/Py is used as the SAF, and the typical heavy metal Pt is used to generate the pure spin current via spin Hall effect (SHE). The pure spin current perpendicularly flows into SAF and drive the magnetizations in SAF to precession. We found that the oscillation frequency of the nano-gap SHNO driven by the pure spin current can reach terahertz once the Ruderman-Kittel-Kasuya-Yosida (RKKY) intensity of SAF and current density are reasonably strong. This terahertz spectrum can be excited even without any external magnetic field. The competition between RKKY interaction and SHE definitely boost up the dynamics of magnetization in SAF. Moreover, the terahertz spectrum can be tuned by DC current and/or RKKY intensity. We also studied the influence of the thickness of SAF on the terahertz spectrum. Finally, the nonreciprocity of the generated terahertz spectrum is demonstrated by introducing DMI between HM and SAF. Our results suggest a possible way to exploit terahertz spintronics devices.

The hydrogen supply in many refineries is becoming a critical issue because of a trend of heavier crude oils and increasingly rigorous legislation. One of the significant problems is that the concentration fluctuation of hydrogen affects product quality of refineries and causes economic losses. This article investigates the disturbance resistance ability of hydrogen network. The Worst-Case Conditional Value-at-Risk (WCVaR) concept which indicates possible minimum hydrogen content in hydrogen networks is introduced to handle this problem. The disturbance resistance ability is optimized in maximization of WCVaR associated with uncertainty distribution. The article can obtain the hydrogen network whose WCVaR is not less than limit hydrogen content. The resistance ability of the obtained network structure is verified by Monte Carlo simulation. The literature example illustrate that the hydrogen network optimized by the WCVaR model performs robustly.

Signatures of sulfur isotope mass-independent fractionation (S-MIF) have been observed in stratospheric sulfate aerosols deposited in polar ice. The S-MIF signatures are thought to be associated with stratospheric photochemistry following stratospheric volcanic eruptions, but the exact mechanism responsible for the production and preservation of these signatures is debated. In order to identify the origin and the mechanism of preservation for these signatures, a series of laboratory photochemical experiments were carried out to investigate the effect of temperature and added O2 on the S-MIF produced by two absorption band systems of SO2: photolysis in the 190 to 220 nm region and photoexcitation in the 250 to 350 nm region. The SO2 photolysis (SO2 + hν → SO + O) experiments showed S-MIF signals with large 34S/34S fractionations, which increases with decreasing temperature. The overall S-MIF pattern observed for photolysis experiments, including high 34S/34S fractionations, positive mass-independent anomalies in 33S, and negative anomalies in 36S, is consistent with a major contribution from optical isotopologue screening effects and data for stratospheric sulfate aerosols. In contrast, SO2 photoexcitation produced products with positive S-MIF anomalies in both 33S and 36S, which is different from stratospheric sulfate aerosols. SO2 photolysis in the presence of O2 produced SO3 with S-MIF signals, suggesting the transfer of the S-MIF anomalies from SO to SO3 by the SO + O2 + M → SO3 + M reaction. This is supported with energy calculations of stationary points on the SO3 potential energy surfaces, which indicate that this reaction occurs slowly on a single adiabatic surface, but that it can occur more rapidly through intersystem crossing. Based on our experimental results, we estimate a termolecular rate constant on the order of 10−37 cm6 molecule−2 s−1. This rate can explain the preservation of mass independent isotope signatures in stratospheric sulfate aerosols and provides a minor, but important, oxidation pathway for stratospheric SO2. The production and preservation of S-MIF signals requires a high SO2 column density to allow for optical isotopologue screening effects to occur and to generate a large enough signature that it can be preserved. In addition, the SO2 plume must reach an altitude of around 20 to 25 km, where SO2 photolysis becomes a dominant process. These experiments are the first step towards understanding the origin of the sulfur isotope anomalies in stratospheric sulfate aerosols.

Gelatinous marrow transformation (GMT) is a rare condition observed in severe illness or malnutrition, in which the bone marrow contains amorphous “gelatinous” extracellular material, and histopathology demonstrates varied degrees of fat cell atrophy and loss of hematopoietic elements. An association of GMT with imatinib use in chronic myeloid leukemia (CML) has been reported recently. The objective of this study is to describe a case of GMT associated with imatinib use and review the existing similar cases in the literature to identify epidemiological patterns and potential imatinib-induced mechanisms leading to gelatinous conversion.

With improved staining and chromosome preparation techniques, meiosis of pollen mother cells (PMCs) and male gametophyte development in autotetraploid cucumber (Cucumis sativus L.) was studied to understand the correlation between chromosomes behaviour and fertility. Various chromosome configurations, e.g. multivalent, quadrivalents, trivalents, bivalents and univalents were observed in most PMCs at metaphase I. Lagging chromosomes were frequently observed at anaphase in both meiotic divisions. In addition, chromosomes segregations were not synchronous and equal in some PMCs during anaphase II and telophase II. Dyads, triads, tetrads with micronuclei and polyads were observed at tetrad stage, and the frequencies of normal tetrad with four microcytes were only 55.4 %. The frequency of abnormal behaviour in each stage of meiosis was counted, and the average value was 37.2 %. The normal meiotic process could be accomplished to form the microspore tetrads via simultaneous cytokinesis. Most microspores could develop into fertile gametophytes with 2 cells and 3 germ pores through the following stages: single-nucleus early stage, single-nucleus late stage and 2-celled stage. The frequency of abnormalities was low during the process of male gametophyte development. The germination rate of pollen grains was 46.9 %. These results suggested that abnormal meiosis in PMCs was the reason for low pollen fertility in the autotetraploid cucumber.

To what degree elevated pulsatile components of blood pressure arise from a primary interaction of ventricular contraction with the impedance of the arterial tree or from more complex phenomena involving backward wave travel in the arterial tree is unknown. We used wave intensity analysis to explore the haemodynamic basis for elevated pulsatile components of blood pressure in 20 hypertensive subjects (47.4± 13.4 years, 158.5±27.7/98.7±14.2 mmHg, means ± SD) compared to 20 normotensive controls (52.2±12.3 years, 108.7±12.2/71.8±7.7 mmHg, means ± SD). Secondly we used dobutamine and norepinephrine as inodilators and vasoconstrictors in normotensive subjects to examine the contributions of ventricular contractility and peripheral vasoconstriction to waves disproportionately elevated in hypertensive compared to normotensive subjects. An elevated central pulse pressure in hypertensive subjects was accounted primarily by the forward wave component (50.4±3.4 vs 35.2±1.8 mmHg, P < 0.001) but the backward wave also contributed significantly (8.9±1.7 vs 1.6±0.4 mmHg, P < 0.002) and was a particularly important component of augmentation pressure (13.5±3.6 vs 0.3±0.6 mmHg, P < 0.01). The forward component arose from the primary forward compression wave (FCW) and the backward component from a backward compression wave (BCW). The BCW/FCW intensity was greater in hypertensive compared to normotensive subjects and in normotensive subjects could be increased by norepinephrine but not by dobutamine. Increased pulse pressure in hypertension results primarily from the FCW but the BCW provides a significant contribution to pulse pressure components particularly augmentation pressure.

Background: Nitroglycerin (NTG) reduces cardiac pre-load and after-load through venodilation and arterial dilation respectively but the relative contributions of these effects to reduction in myocardial wall stress is unknown. Methods: We estimated myocardial wall stress from transthoracic echocardiographic imaging of the left ventricle (LV) and LV pressure estimated from carotid tonometry during systole. Nineteen subjects aged 43.3 ± 2.7 (mean ± SE) years were studied before and 7–12 min after NTG (400 ìg sublingually). Carotid pressure calibrated by mean and diastolic blood pressure (BP) was used to calculate time-varying LV wall stress from endocardial and epicardial volumes obtained from Tomtec wall tracking analysis. The relative contributions of reductions in systolic pressure and in LV volumes and to overall reduction in LV wall stress were calculated assuming that volume or pressures after NTG were identical to baseline values. Results: NTG decreased peak LV stress (pre: 387±22; post: 329±22kdynes/cm2, P

Background. Organic nitrates (e.g. nitroglycerin) are highly selective dilators of muscular conduit arteries. By contrast, the endogenous inorganic nitrite anion (NO2−) is thought to be a hypoxia-dependent dilator of small resistance arterioles, via its reduction to vasodilating nitric oxide (NO) by deoxyhaemoglobin. Objective. To establish selectivity of nitrite for resistance versus conduit arteries. Methods and Results A series of forearm blood flow (FABF) studies were performed in healthy volunteers. Intra-brachial sodium nitrite (8.7 μmol/min) markedly increased radial artery diameter (assessed using ultrasound) by 37.6 ± 9.7% (P < 0.001), with HbO2 ∼99%. Furthermore, nitrite (0.087–87 μmol/min) displayed similar selectivity as nitroglycerin (0.003–1 μg/min) for conduit arteries, compared to resistance arterioles (FABF). Intravenous administration of sodium nitrite (8.7 μmol/min) dilated the contralateral radial artery by 10.7 ± 1.8% (P < 0.01) and lowered central systolic blood pressure (BP) by ~12mmHg from 98.3 ± 12.3 to 86.7 ± 15.1 mmHg (P = 0.02) without any change in peripheral BP; nitrite also reduced augmentation index and pulse wave velocity. In contrast to nitrite’s effects on FABF, induction of hypoxia (breathing 12% O2) paradoxically inhibited nitrite-induced dilatation of the radial artery to a similar extent as hyperoxia/ breathing 100% O2 (both P < 0.001 compared to normoxia). Conclusions. Contrary to expectation, inorganic nitrite is a normoxia-dependent selective conduit artery dilator with similar selectivity to nitroglycerin. A specific advantage of nitrite is that it lacks the problems of development of tolerance and endothelial dysfunction, which limit the efficacy of organic nitrates. The selective central BP-lowering effects of nitrite have therapeutic potential to reduce cardiovascular events.

Background: Pulse wave velocity (PWV), measure of aortic stiffness, is predictive of cardiovascular events. PWV is strongly related to age and blood pressure but its relation to other risk factors and presence of calcification is unclear. We sought to determine the association between PWV and cardiovascular risk factors, aortic calcification and heritability of PWV. Methods: Subjects were 900 female twins (504 dizygotic, 396 monozygotic), 53–63 years (interquartile range), from TwinsUK cohort. PWV was determined over the carotid-femoral region using the SphygmoCor system. Age matched women (n=40) with PWV in the 1st and 3rd tertiles of the PWV distribution (entire cohort) underwent computed tomography from the carotid to iliac bifurcation to determine calcification. Calcium content was scored using the Agatston method. Heritability of PWV was determined using structural equation modelling. Results: In multivariate regression PWV was significantly correlated with age, mean arterial blood pressure (MAP) and heart rate (standardized regression coefficients, β=0.41, 0.39 and 0.20 respectively, each P

No abstract available.