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Citrusinol was regarded as an antineoplastic agent, and acetyl-citrusinol was synthesized as a new derivative of citrusinol. The interactions of bovine serum albumin (BSA) and calf thymus DNA (ct-DNA) with citrusinol and acetyl-citrusinol were studied. The structure of acetyl-citrusinol was identified by nuclear magnetic resonance (13C NMR, 1H NMR) and heteronuclear multiple-bond correlation (HMBC). Fluorescence spectrum and molecular docking were used to investigate the interactions of citrusinol and acetyl-citrusinol with BSA. The UV–Vis spectroscopy was used to study the interactions of citrusinol and acetyl-citrusinol with ct-DNA. The citrusinol and acetyl-citrusinol combining with BSA showed the fluorescence quenching and a decrease in the maximum emission wavelength. The molecular docking results showed that there were stable combinations of citrusinol and acetyl-citrusinol with BSA. Thus, the interactions between citrusinol and acetyl-citrusinol with BSA were mainly hydrophobic and hydrogen bonding. According to the UV–Vis spectrum, citrusinol, and acetyl-citrusinol interacted with ct-DNA via electrostatic interaction.

Stressed plants and polymer production can emit many unsaturated volatile organic esters (UVOEs). However, secondary organic aerosol (SOA) formation of UVOEs remains unclear, especially under complex ambient conditions. In this study, we mainly investigated ethyl methacrylate (EM) ozonolysis. Results showed that a substantial increase in secondary H2SO4 particles promoted SOA formation with increasing SO2. An important reason was that the homogeneous nucleation of more H2SO4 at high SO2 level provided greater surface area and volume for SOA condensation. However, increased primary H2SO4 with seed acidity enhanced EM uptake but reduced SOA formation. This was ascribed to the fact that the ozonolysis of more adsorbed EM was hampered with the formation of surface H2SO4 at higher particle acidity. Moreover, the increase in secondary H2SO4 particle via homogeneous nucleation favored to the oligomerization of oxidation products, whereas the increasing of primary H2SO4 with acidity in the presence of seed tended to promote the functionalization conversion products. This study indicated that the role of increased H2SO4 to EM-derived SOA may not be the same under different ambient conditions, which helps to advance our understanding of the complicated roles of H2SO4 in the formation of EM-derived SOA.

Atmospheric submicrometer aerosols have a great effect on air quality and human health, while their formation and evolution processes are still not fully understood. Herein, the crucial role of atmospheric oxidation capacity, as characterized by OH exposure dose in the formation and evolution of secondary submicrometer aerosols, was systematically investigated based on a highly time-resolved chemical characterization of PM1 in a southern suburb of Beijing in summertime from 25 July to 21 August 2019. The averaged concentration of PM1 was 19.3 ± 11.3 µg m−3, and nearly half (48.3 %) of the mass was organic aerosols (OAs) during the observation period. The equivalent photochemical age (ta) estimated from the ratios of toluene to benzene was applied to characterize the OH exposure dose of the air mass, in which an observation period with the similar sources and minimal influence of fresh emission was adopted. The relationships of non-refractory PM1 species, OA factors (i.e., one hydrocarbon-like and three oxygenated organic aerosol factors) and elemental compositions (e.g., H∕C, O∕C, N∕C, S∕C, OM∕OC, and OSc) to ta were analyzed in detail. It was found that higher PM1 concentration accompanied longer ta, with an average increase rate of 0.8 µgm-3h-1. Meanwhile, the formation of sulfate and more oxidized oxygenated OA were most sensitive to the increase in ta, and their contributions to PM1 were enhanced from 22 % to 28 % and from 29 % to 48 %, respectively, as ta increased. In addition, OSc and the ratios of O∕C and OM∕OC increased with the increase in ta. These results indicated that photochemical aging is a key factor leading to the evolution of OA and the increase in PM1 in summertime.

N,N-dimethylhydroxylamine (DMHA) is an effective novel salt-free reductant used in spent fuel reprocessing. This paper reports the effect of monomethylhydrazine (MMH) on γ-ray radiolysis and radiolytic by-products of DMHA in HNO3. The presence of MMH improves the stability of DMHA against radiation significantly, the main radiolytic by-products are N-methylhydroxylamine, HCHO, HCOOH and HNO2, which concentration increases with the dose. The concentration of N-methylhydroxylamine increases with the MMH concentration, but that of HCHO, HCOOH and HNO2 decreases with increasing MMH concentration. These results will provide considerable reference for the application of DMHA in the PUREX process.

Secondary aerosols are a major component of PM2.5, yet their formation mechanisms in the ambient atmosphere are still unclear. Based on field measurements in downtown Beijing, we show that the photolysis of nitrous acid (HONO) may promote the formation of organic and nitrate aerosols in winter in Beijing, which is supported by the fact that the mass concentrations of organic and nitrate aerosols linearly increase as a function of HONO consumed from early morning to noon. The increased nitrate content also leads to the formation of ammonium particulate matter through enhancing the neutralization of nitrate and sulfate by ammonia. We further illustrate that during pollution events in winter in Beijing, over 50 % of the ambient HONO may be related to traffic-related emissions, including direct emissions and formation via the reaction between OH and vehicle-emitted NO. Overall, our results indicate that traffic-related HONO may play an important role in the oxidative capacity and in turn contribute to haze formation in winter in Beijing. The mitigation of HONO and NOx emissions from vehicles may be an effective way to reduce the formation of secondary aerosols and severe haze events in winter in Beijing.

Ochratoxin A (OTA) is a possibly carcinogenic mycotoxin which is one of the most abundant food contaminants. It can be normally monitored and detected by immunochromatographic assays (ICG) which have a good sensitivity and specificity and easy to operate. However, the development of normal ICG is based on traditional OTA-conjugates or chemosynthetic mimotope peptides, which are very high-cost reagents with a detrimental effect on the environment and operators. This study takes advantage of both biosynthetic mimetic OTA-conjugates and a convenient IGG to develop a novel environmental-friendly and low-cost ICG for the rapid detection of OTA. Qualitatively, the visual cut-off level of the developed ICG for OTA was 0.8 ng/ml, which is 10-fold more sensitive than the chemosynthetic mimotope peptide based ICG, while there is no cross-reaction with other mycotoxins. The assay takes only 15 min to acquire results visible to the naked eye. Quantitatively, the half inhibition concentration of the ICG setup with mimetic OTA-conjugates was 0.187 ng/ml, with a linear range of 0.015 to 0.5 ng/ml. These results demonstrate the potential to adapt the method for detecting other toxic mycotoxins.

We investigated the ozone pollution trend and its sensitivity to key precursors from 1990 to 2015 in the United States using long-term EPA Air Quality System (AQS) observations and mesoscale simulations. The modeling system, a coupled regional climate–air quality model (CWRF-CMAQ; Climate-Weather Research Forecast and the Community Multiscale Air Quality), captured well the summer surface ozone pollution during the past decades, having a mean slope of linear regression with AQS observations of ∼0.75. While the AQS network has limited spatial coverage and measures only a few key chemical species, CWRF-CMAQ provides comprehensive simulations to enable a more rigorous study of the change in ozone pollution and chemical sensitivity. Analysis of seasonal variations and diurnal cycle of ozone observations showed that peak ozone concentrations in the summer afternoon decreased ubiquitously across the United States, up to 0.5 ppbv yr−1 in major non-attainment areas such as Los Angeles, while concentrations at certain hours such as the early morning and late afternoon increased slightly. Consistent with the AQS observations, CMAQ simulated a similar decreasing trend of peak ozone concentrations in the afternoon, up to 0.4 ppbv yr−1, and increasing ozone trends in the early morning and late afternoon. A monotonically decreasing trend (up to 0.5 ppbv yr−1) in the odd oxygen (Ox=O3+NO2) concentrations are simulated by CMAQ at all daytime hours. This result suggests that the increased ozone in the early morning and late afternoon was likely caused by reduced NO–O3 titration, driven by continuous anthropogenic NOx emission reductions in the past decades. Furthermore, the CMAQ simulations revealed a shift in chemical regimes of ozone photochemical production. From 1990 to 2015, surface ozone production in some metropolitan areas, such as Baltimore, has transited from a VOC-sensitive environment (>50 % probability) to a NOx-sensitive regime. Our results demonstrated that the long-term CWRF-CMAQ simulations can provide detailed information of the ozone chemistry evolution under a changing climate and may partially explain the US ozone pollution responses to regional and national regulations.

We compare Community Multiscale Air Quality (CMAQ) model predictions with measured nitrous acid (HONO) concentrations in Beijing, China, for December 2015. The model with the existing HONO chemistry in CMAQ severely underestimates the observed HONO concentrations with a normalized mean bias of −97 %. We revise the HONO chemistry in the model by implementing six additional heterogeneous reactions in the model: the reaction of nitrogen dioxide (NO2) on ground surfaces, the reaction of NO2 on aerosol surfaces, the reaction of NO2 on soot surfaces, the photolysis of aerosol nitrate, the nitric acid displacement reaction, and the hydrochloric acid displacement reaction. The model with the revised chemistry substantially increases HONO predictions and improves the comparison with observed data with a normalized mean bias of −5 %. The photolysis of HONO enhances daytime hydroxyl radical by almost a factor of 2. The enhanced hydroxyl radical concentrations compare favorably with observed data and produce additional sulfate via the reaction with sulfur dioxide, aerosol nitrate via the reaction with nitrogen dioxide, and secondary organic aerosols via the reactions with volatile organic compounds. The additional sulfate stemming from revised HONO chemistry improves the comparison with observed concentration; however, it does not close the gap between model prediction and the observation during polluted days.

Aerosols from surface emission can be transported upwards through convective mixing in the planetary boundary layer (PBL), which subsequently interact with clouds, serving as important sources to nucleate droplets or ice particles. However, the evolution of aerosol composition during this vertical transport has yet to be explicitly understood. In this study, simultaneous measurements of detailed aerosol compositions were conducted at two sites, namely urban Beijing (50 m above sea level – a.s.l.) and Haituo mountain (1344 m a.s.l.) during wintertime, representing the anthropogenically polluted surface environment and the top of the PBL, respectively. The pollutants from surface emissions were observed to reach the mountain site on daily basis through daytime PBL convective mixing. From the surface to the top of PBL, we found efficient transport or formation of lower-volatility species (black carbon, sulfate, and low-volatile organic aerosol, OA); however, a notable reduction in semivolatile substances, such as the fractions of nitrate and semivolatile OA reduced by 74 % and 76 %, respectively, during the upward transport. This implies that the mass loss of these semivolatile species was driven by the evaporation process, which repartitioned the condensed semivolatile substances to the gas phase when aerosols were transported and exposed to a cleaner environment. In combination with the oxidation processes, these led to an enhanced oxidation state of OA at the top of the PBL compared to surface environment, with an increase of oxygen to carbon atomic ratio by 0.2. Such a reduction in aerosol volatility during vertical transport may be important in modifying its viscosity, nucleation activity, and atmospheric lifetime.

Although the anthropogenic emissions of SO2 have decreased significantly in China, the decrease in SO42- in PM2.5 is much smaller than that of SO2. This implies an enhanced formation rate of SO42- in the ambient air, and the mechanism is still under debate. This work investigated the formation mechanism of particulate sulfate based on statistical analysis of long-term observations in Shijiazhuang and Beijing supported with flow tube experiments. Our main finding was that the sulfur oxidation ratio (SOR) was exponentially correlated with ambient RH in Shijiazhuang (SOR = 0.15+0.0032×exp⁡(RH/16.2)) and Beijing (SOR = -0.045+0.12×exp⁡(RH/37.8)). In Shijiazhuang, the SOR is linearly correlated with the ratio of aerosol water content (AWC) in PM2.5 (SOR = 0.15+0.40×AWC/PM2.5). Our results suggest that uptake of SO2 instead of oxidation of S(IV) in the particle phase is the rate-determining step for sulfate formation. NH4NO3 plays an important role in the AWC and the change of particle state, which is a crucial factor determining the uptake kinetics of SO2 and the enhanced SOR during haze days. Our results show that NH3 significantly promoted the uptake of SO2 and subsequently the SOR, while NO2 had little influence on SO2 uptake and SOR in the presence of NH3.

Nutrient-rich peat soils have previously been demonstrated to lose carbon despite higher photosynthesis and litter production compared to nutrient-poor soils, where instead carbon accumulates. To understand this phenomenon, we used a process-oriented model (CoupModel) calibrated on data from two closely located drained peat soil sites in boreal forests in Finland, Kalevansuo and Lettosuo, with different soil C/N ratios. Uncertainty-based calibrations were made using eddy-covariance data (hourly values of net ecosystem exchange) and tree growth data. The model design used two forest scenarios on drained peat soil, one nutrient-poor with dense moss cover and another with lower soil C/N ratio with sparse moss cover. Three vegetation layers were assumed: conifer trees, other vascular plants, and a bottom layer with mosses. Adding a moss layer was a new approach, because moss has a modified physiology compared to vascular plants. The soil was described by three separate soil organic carbon (SOC) pools consisting of vascular plants and moss litter origin and decomposed organic matter. Over 10 years, the model demonstrated a similar photosynthesis rate for the two scenarios, 903 and 1,034 g C m−2 yr−1, for the poor and rich site respectively, despite the different vegetation distribution. For the nutrient-rich scenario more of the photosynthesis produce accumulated as plant biomass due to more trees, while the poor site had abundant moss biomass which did not increase living aboveground biomass to the same degree. Instead, the poor site showed higher litter inputs, which compared with litter from vascular plants had low turnover rates. The model calibration showed that decomposition rate coefficients for the three SOC pools were similar for the two scenarios, but the high quantity of moss litter input with low decomposability for the nutrient poor scenario explained the major difference in the soil carbon balance. Vascular plant litter declined with time, while SOC pools originating from mosses accumulated with time. Large differences between the scenarios were obtained during dry spells where soil heterotrophic respiration doubled for the nutrient-rich scenario, where vascular plants dominated, owing to a larger water depletion by roots. Where moss vegetation dominated, the heterotrophic respiration increased by only 50% during this dry period. We suggest moss vegetation is key for carbon accumulation in the poor soil, adding large litter quantities with a resistant quality and less water depletion than vascular plants during dry conditions.

Copper-based materials have been selected as heat-sink materials in some nuclear fusion reactors, where a great number of structural defects will be created due to the irradiation of energetic particles. In the practice of fusion reactors, an important issue is how the defects in copper heat-sink material affect its thermal transport property. However, there is no systematic study on the relation between thermal conductivity and the concentrations of various point defects in copper up to now. Our theoretical calculations show that the thermal conductivity ($$ \kappa $$) of Cu is significantly reduced by the presence of vacancies, self-interstitial atoms, SIA–vacancy pairs and the doped impurity tungsten (W) at finite temperatures. Among these concerned point defects, the doped impurity W plays the strongest role in impeding the thermal transport of conduction electrons, and the presence of 4% W impurity in Cu leads to about 80% reduction in $$ \kappa $$ as compared to that of the defect-free Cu system ($$ \kappa_{0} $$). Furthermore, it is revealed that during the cascade, the thermal transport property of Cu changes as the structural defects evolve, and the thermal transport of electrons is impeded significantly in the initial stages of cascade. In addition, our calculations show that the Wiedemann–Franz law is still valid in defected copper systems.

Ganoderic acid T (GAT) has many pharmacological functions such as antitumor and antimycobacterial activity. However, to the best of our knowledge, no commercial high-purity GAT is available and the experimental and theoretical study of Raman spectrum of GAT has never been reported up to date. Therefore, in this work, GAT was extracted and purified from the mycelia of G. lucidum by ourselves, and its Raman spectrum was measured and analyzed based on density functional theory (DFT) calculation at B3LYP/6-311+G(d, p) level. The research on the molecular structural and spectral properties may lead to deeper insights into the functions and better applications of GAT.

It has been recognized that carbon nanomaterials and soot particles are toxic for human health, but the influence of functionalization on their toxicity as well as the evolution of the toxicity of carbon nanomaterials due to chemical aging in the atmosphere is still controversial. In the current study, the oxidation potential measured by dithiothreitol (DTT) decay rate and the cytotoxicity to murine macrophage cells of different functionalized carbon nanomaterials were investigated to understand the role of functionalization in their toxicities. The DTT decay rates of special black 4A (SB4A), graphene, graphene oxide, single-walled carbon nanotubes (SWCNTs), SWCNT-OH and SWCNT-COOH were 45.9±3.0, 58.5±6.6, 160.7±21.7, 38.9±8.9, 57.0±7.2 and 36.7±0.2 pmol min−1 µg−1, respectively. Epoxide was found to be mainly responsible for the highest DTT decay rate of graphene oxide compared to other carbon nanomaterials based on comprehensive characterizations. Both carboxylation and hydroxylation showed little influence on the oxidation potential of carbon nanomaterials, while epoxidation contributes to the enhancement of oxidation potential. All these carbon nanomaterials were toxic to the murine J774 cell line. However, oxidized carbon nanomaterials (graphene oxide, SWCNT-OH and SWCNT-COOH) showed weaker cytotoxicity to the J774 cell line compared to the corresponding control sample as far as the metabolic activity was considered and stronger cytotoxicity to the J774 cell line regarding the membrane integrity and DNA incorporation. These results imply that epoxidation might enhance the oxidation potential of carbon nanomaterials.

Methoxyphenols are an important organic component of wood-burning emissions and considered to be potential precursors of secondary organic aerosol (SOA). In this work, the rate constant and SOA formation potential for the OH-initiated reaction of 4-allyl-2-methoxyphenol (eugenol) were investigated for the first time in an oxidation flow reactor (OFR). The rate constant was 8.01±0.40×10-11 cm3 molecule−1 s−1, determined by the relative rate method. The SOA yield first increased and then decreased as a function of OH exposure and was also dependent on eugenol concentration. The maximum SOA yields (0.11–0.31) obtained at different eugenol concentrations could be expressed well by a one-product model. The carbon oxidation state (OSC) increased linearly and significantly as OH exposure rose, indicating that a high oxidation degree was achieved for SOA. In addition, the presence of SO2 (0–198 ppbv) and NO2 (0–109 ppbv) was conducive to increasing SOA yield, for which the maximum enhancement values were 38.6 % and 19.2 %, respectively. The N∕C ratio (0.032–0.043) indicated that NO2 participated in the OH-initiated reaction, subsequently forming organic nitrates. The results could be helpful for further understanding the SOA formation potential from the atmospheric oxidation of methoxyphenols and the atmospheric aging process of smoke plumes from biomass burning emissions.

In a series of 10-day campaigns in Ontario and Quebec, Canada, between 2005 and 2007, ozonesondes were launched twice daily in conjunction with continuous high-resolution wind-profiling radar measurements. Windprofilers can measure rapid changes in the height of the tropopause, and in some cases follow stratospheric intrusions. Observed stratospheric intrusions were studied with the aid of a Lagrangian particle dispersion model and the Canadian operational weather forecast system. Definite stratosphere-troposphere transport (STT) events occurred approximately every 2–3 days during the spring and summer campaigns, whereas during autumn and winter, the frequency was reduced to every 4–5 days. Although most events reached the lower troposphere, only three events appear to have significantly contributed to ozone amounts in the surface boundary layer. Detailed calculations find that STT, while highly variable, is responsible for an average, over the seven campaigns, of 3.1% of boundary layer ozone (1.2 ppb), but 13% (5.4 ppb) in the lower troposphere and 34% (22 ppb) in the middle and upper troposphere, where these layers are defined as 0–1 km, 1–3 km, and 3–8 km respectively. Estimates based on counting laminae in ozonesonde profiles, with judicious choices of ozone and relative humidity thresholds, compare moderately well, on average, with these values. The lamina detection algorithm is then applied to a large dataset from four summer ozonesonde campaigns at 18 North American sites between 2006 and 2011. The results show some site-to-site and year-to-year variability, but stratospheric ozone contributions average 4.6% (boundary layer), 15% (lower troposphere) and 26% (middle/upper troposphere). Calculations were also performed based on the TOST global 3D trajectory-mapped ozone data product. Maps of STT in the same three layers of the troposphere suggest that the STT ozone flux is greater over the North American continent than Europe, and much greater in winter and spring than in summer or fall. When averaged over all seasons, magnitudes over North America show similar ratios between levels to the previous calculations, but are overall 3–4 times smaller. This may be because of limitations (trajectory length and vertical resolution) to the current TOST-based calculation.

Physical review letters : PRL 127(15), 021101 (2021). doi:10.1103/PhysRevLett.127.021101, Published by American Physical Society, College Park, Md.

Study question Can oocytes isolated from transgender men after oophorectomy support embryonic development? Summary answer Embryo developmental arrest at 4–8cell stage (day 3 embryos) indicates poor quality of in vitro matured oocytes from transgender men. What is known already Gender affirming surgery for transgender men leads to permanent infertility, as it involves bilateral oophorectomy. Current approaches for fertility preservation, such as oocyte freezing following ovarian hyperstimulation, may interfere with the wanted masculine characteristics and enhance gender dysphoria. In vitro matured oocytes (IVM) isolated following oophorectomy have been proposed as a source of potential gametes to ensure fertility preservation for transgender men with a child wish. From previous studies, it has been shown that these oocytes are able to undergo maturation and display normal spindles, but their competence to be fertilized and support embryonic development has not been addressed yet. Study design, size, duration We evaluated the quality of in vitro matured oocytes isolated from ovaries of transgender men by applying calcium imaging and monitoring fertilization and embryonic development following intracytoplasmic sperm injection (ICSI). Ovaries were collected in cold (4oC) or warm (37oC) medium, to investigate the best collection procedure. So far, results from four transgender men have been included. Participants/materials, setting, methods: Ovaries from four transgender men undergoing testosterone treatment were collected after oophorectomy in cold or warm medium. Cumulus oocyte complexes (COCs) were isolated and cultured in maturation medium for 48hrs. Mature oocytes were injected with donated sperm and assessed either by calcium imaging, measuring the total calcium release following injection, or following embryonic development. Donated in vitro matured oocytes, germinal vesicle(GV) or metaphase I(MI) origin, from other patients undergoing IVF treatment were used as controls. Main results and the role of chance In total, 179 COCs were collected from ovaries (n = 8) of four transgender men. From the COCs collected in warm medium, 73/105(69%) survived and 33/73(45%) reached metaphase II (MII). Of 21 MII injected with sperm, 13/21(62%) fertilized, 9/21(43%) formed 2 pronuclei (PN), 8/9(89%) reached the 2-cell stage, 3/9(33%) reached 4–8cell stage but arrested. From 74 COCs isolated in cold medium, 57/74(77%) survived and 28/57(49%) matured. Of the 11 MII injected with sperm, 7/11(64%) fertilized, 6/11(54%) formed 2PN, 6/6(100%) reached the 2-cell stage, 4/6(67%) reached 4–8cell but arrested. In the control group, 10/13 oocytes injected with the same sperm sample, were normally fertilized (77%), 8/10(80%) reached the 2-cell stage, 7/10(70%) reached the 4–8cell stage and 4/10(40%) became blastocysts. From the warm, cold and control conditions, respectively 12,14 and 17 MII oocytes were used for calcium imaging. The product of amplitude and frequency of calcium peaks, representing total calcium release, was calculated. Oocytes showed an average release of 0.66AU and 1.69AU for the warm and cold condition, respectively. The average value for control oocytes was 2.19AU. Limitations, reasons for caution One major limitation of our study is the lack of ovaries from cis women as control group. Our control oocytes originated from women undergoing IVF treatment and have undergone ovarian stimulation. Furthermore, the number of oocytes analysed and number of patients per group was limited and is being increased. Wider implications of the findings: Our data indicate that in vitro matured oocytes from transgender men ovaries display poor quality, as demonstrated by the poor embryonic development. In the future, we will apply nuclear transfer technology as a mean to overcome embryonic developmental arrest in this group of oocytes. Trial registration number Not applicable

International audience; Precise knowledge of the charge and rigidity dependence of the secondary cosmic ray fluxes and the secondary-to-primary flux ratios is essential in the understanding of cosmic ray propagation. We report the properties of heavy secondary cosmic ray fluorine F in the rigidity $R$ range 2.15 GV to 2.9 TV based on 0.29 million events collected by the Alpha Magnetic Spectrometer experiment on the International Space Station. The fluorine spectrum deviates from a single power law above 200 GV. The heavier secondary-to-primary F/Si flux ratio rigidity dependence is distinctly different from the lighter B/O (or B/C) rigidity dependence. In particular, above 10 GV, the $^{\textrm{F/Si}}_{\textrm{B/O}}$ ratio can be described by a power law $R^δ$ with $δ=0.052±0.007$. This shows that the propagation properties of heavy cosmic rays, from F to Si, are different from those of light cosmic rays, from He to O, and that the secondary cosmic rays have two classes.

To provide insight into the planetary boundary layer (PBL) production of ozone (O3) over the North China Plain, the Air chemistry Research in Asia (ARIAs) campaign conducted aircraft measurements of air pollutants over Hebei Province, China, between May and June 2016. We evaluate vertical profiles of trace gas species including O3, nitrogen oxides (NOx), carbon monoxide (CO), and volatile organic compounds (VOCs) and relate to rates of O3 production. This analysis shows measured O3 levels ranged from 45 to 146 ppbv, with the peak median concentration (∼ 92 ppbv) occurring between 1000 and 1500 m. The NOx concentrations exhibited strong spatial and altitudinal variations, with a maximum of 53 ppbv. Ratios of CO∕CO2 indicate the prevalence of low-efficiency combustion from biomass burning and residential coal burning but indicate some success of regional pollution controls compared to earlier studies in China. Concentrations of total measured VOCs reveal alkanes dominate the total measured volume mixing ratio of VOCs (68 %), and sources include vehicular emissions, fuel and solvent evaporation, and biomass burning. Alkanes and alkenes/alkynes are responsible for 74 % of the total VOC reactivity assessed by calculating the OH loss rates, while aromatics contribute the most to the total ozone formation potential (OFP) (43 %) with toluene, m/p-xylene, ethylene, propylene, and i-pentane playing significant roles in the aloft production of O3 in this region. In the PBL below 500 m, box model calculations constrained by measured precursors indicate the peak rate of mean O3 production was ∼ 7 ppbv h−1. Pollution frequently extended above the PBL into the lower free troposphere around 3000 m, where NO2 mixing ratios (∼ 400 pptv) led to net production rates of O3 up to ∼ 3 ppbv h−1; this pollution can travel substantial distances downwind. The O3 sensitivity regime is determined to be NOx-limited throughout the PBL, whereas it is more VOC-limited at low altitudes near urban centers, demonstrating that control of both VOCs and NOx is needed to reduce aloft O3 pollution over Hebei.

The discovery of a two-dimensional electron gas (2DEG) at the $$\hbox {LaAlO}_3/\hbox {SrTiO}_3$$ LaAlO 3 / SrTiO 3 interface has set a new platform for all-oxide electronics which could potentially exhibit the interplay among charge, spin, orbital, superconductivity, ferromagnetism and ferroelectricity. In this work, by using angle-resolved photoemission spectroscopy and conductivity measurement, we found the reduction of 2DEGs and the changes of the conductivity nature of some ferroelectric oxides including insulating Nb-lightly-substituted $$\hbox {KTaO}_3$$ KTaO 3 , $$\hbox {BaTiO}_3$$ BaTiO 3 (BTO) and (Ca,Zr)-doped BTO across paraelectric-ferroelectric transition. We propose that these behaviours could be due to the increase of space-charge screening potential at the 2DEG/ferroelectric regions which is a result of the realignment of ferroelectric polarisation upon light irradiation. This finding suggests an opportunity for controlling the 2DEG at a bare oxide surface (instead of interfacial system) by using both light and ferroelectricity.

N, N-dimethylhydroxylamine (DMHA) is a new salt-free reductant used in spent fuel reprocessing, this paper reports the effect of HNO2 on γ-ray radiolysis and radiolytic products of DMHA in nitric acid medium. DMHA concentration in irradiated samples decreases with the increasing dose and initial HNO2 concentration, and the radiolytic rate of DMHA is lower than 21% at 10 kGy supposed to be the maximum dose absorbed by the reagent during the U/Pu separation and the Pu purification. The main radiolytic products are H2, CH3NHOH, HCHO, and HCOOH, and their quantity increases with the dose and initial HNO2 concentration.

We examined the effects of tumor necrosis factor-α (TNFα) and interleukin-6 (IL6) gene knockout in preserving the bone loss induced by ovariectomy (OVX) and the mechanisms involved in bone metabolism. Twenty female wild-type (WT), TNFα-knockout (TNFα−/−) or IL6-knockout (IL6−/−) mice aged 12 weeks were sham-operated (SHAM) or subjected to OVX and killed after 4 weeks. Bone mass and skeletal microarchitecture were determined using micro-CT. Bone marrow stromal cells (BMSCs) from all three groups (WT, TNFα−/− and IL6−/−) were induced to differentiate into osteoblasts or osteoclasts and treated with 17-β-estradiol. Bone metabolism was assessed by histological analysis, serum analyses and qRT-PCR. OVX successfully induced a high turnover in all mice, but a repair effect was observed in TNFα−/− and IL6−/− mice. The ratio of femoral trabecular bone volume to tissue volume, trabecular number and trabecular thickness were significantly decreased in WT mice subjected to OVX, but increased in TNFα−/− mice (1.62, 1.34, 0.27-fold respectively; P −/− mice (1.34, 0.80, 0.22-fold respectively; P −/− mice when compared to the IL6−/− mice. Both, TNFα−/− and IL6−/− BMSCs exhibited decreased numbers of TRAP-positive cells and an increase in ALP-positive cells, with or without E2 treatment (P TNFα or IL6 significantly upregulated mRNA expressions of osteoblast-related genes (Runx2 and Col1a1) and downregulated osteoclast-related mRNA for TRAP, MMP9 and CTSK in vivo and in vitro, TNFα knockout appeared to have roles beyond IL6 knockout in upregulating Col1a1 mRNA expression and downregulating mRNA expressions of WNT-related genes (DKK1 and Sost) and TNF-related activation-induced genes (TRAF6). TNFα seemed to be more potentially invasive in inhibiting bone formation and enhancing TRAF6-mediated osteoclastogenesis than IL6, implying that the regulatory mechanisms of TNFα and IL6 in bone metabolism may be different.

In this work, Raman measurements were performed with quenched LiCl-KCl-LiF-ZrCl4/ZrF4/K2ZrF6 salt mixtures for deciphering the coordination chemistry of zirconium(IV) in the presence of fluoride ion in the melt. The occurrence of ZrCl62-, ZrCl4F22-, ZrF62-, ZrF73- and ZrF84- in melt at different F/Zr molar ratios was confirmed by Raman spectra. The electrochemical redox behaviors of zirconium in LiCl-KCl-LiF-ZrCl4 were also examined at 773 K. Transient methods such as cyclic voltammetry and square wave voltammetry were used. In LiCl-KCl-LiF-ZrCl4 with LiF concentration less than 1.27 wt% (molar ratio F/Zr 101), the reduction of Zr(IV) followed a two-step mechanism of Zr(IV)/Zr(III) and Zr(III)/Zr(0) at the potentials of about -0.85 and -1.40 V versus Pt, respectively. (C) 2018 The Electrochemical Society.

In vitro and in vivo studies suggested that polyphenol epigallocatechin 3-gallate (EGCG) in tea may have anti-carcinogenic effect on prostate cells, but this protective effect has less been examined in epidemiology studies. We aimed to investigate the association between prostate cancer (PCA) risk and habitual green tea intake among Chinese men in Hong Kong; meanwhile, the relationship with EGCG was also explored. We consecutively recruited 404 PCA cases and 395 controls from the same hospital who had complete data on habitual tea consumption, including green, oolong, black and pu’er tea. We reconstructed the level of EGCG intake according to a standard questionnaire and the analytic values for EGCG extracted from the literature published by Lin et al. in 2003. We calculated odds ratios (ORs) for tea consumption and EGCG intake using unconditional multiple logistic regression, and examined their exposure–-response relationships with PCA risk. A total of 32 cases and 50 controls reported habitual green tea drinking, showing an adjusted OR of 0.60 (95% confidence interval (CI): 0.37, 0.98). A moderate excess risk was observed among the habitual pu’er tea drinkers (OR=1.44, 95% CI: 1.02, 1.91). A significantly lower intake of EGCG was observed among cases (54.4 mg) than the controls (72.5 mg), which resulted in an inverse gradient of PCA risk with the increasing intake of EGCG (test for trend, P=0.015). PCA risk among Chinese men in Hong Kong was inversely associated with green tea consumption and EGCG intake, but these results need to be replicated in larger studies.

Resistive Plate Chambers have largely been used in High Energy Physics and Cosmic Ray research. In view of using this detector for calorimetry applications it is important to know the maximum measurable particle density, or its intrinsic linearity limit, which is tightly related to the dimension of the discharge region. In this paper we report the results of measurements performed at the Beam Test Facility (INFN National Laboratory of Frascati, Italy) where the intrinsic linearity of bakelite RPCs operated in streamer mode has been tested at different impinging particle densities.

Objective The objective of this study was to compare the activity and biological function of leukocytes isolated using apheresis platelet leukoreduction system chambers (LRSC), whole blood leukoreduction filters (LRF), and leukocytes in unfiltered peripheral whole blood (WB). Methods Peripheral blood mononuclear cells (PBMCs) and granulocytes were obtained by density gradient centrifugation using recovery filters and WB. Flow cytometry was used to detect the activity, phenotype, and apoptosis ratio of each cell subtype. Results The proportion of lymphocytes obtained from PBMCs was similar when using the two different filters as compared to traditional isolation; however, there were significant differences between the monocytes and granulocytes. The phenotypic frequency of lymphocytes was similar, but the apoptosis rate of lymphocytes from the two filters was slightly higher. Additionally, monocytes isolated via the three sources were able to be induced into dendritic cells expressing specific molecules; Granulocytes isolated from the LRF showed a lower purity and a higher level of apoptosis than granulocytes isolated from the WB. Conclusion Compared with WB, the PBMCs isolated from the filters used in our blood center had no statistical difference in their activity and biological function, but they did differ in the proportion and quantity of monocytes and granulocytes. Our results show that the two filters can be used as an alternative method to collect leukocytes, which solves the problem of an insufficient blood supply for clinical and basic science research. Thus, these filters have significant value beyond their practical use in clinics.

Obesity is a major risk factor of preventable deaths worldwide, with increasing rates being observed in adults and children. To understand the mechanisms of obesity development, genetically lean (Duroc strain) and obese (Rongchang strain) pigs were used to identify potential differences in muscle and adipose development patterns following consumption of an identical diet for 180 days. Lean pigs had a significantly higher lean percentage (67.79% versus 44.71%) and lower obesity index (0.68 versus 0.84) than obese pigs. They also exhibited significantly lower adipocyte volumes and higher myofibre cross-sectional areas. Quantitative polymerase chain reaction showed that lean pigs had a significantly higher expression of muscle growth-related genes and lower expression of lipogenesis-related genes. By contrast, obese pigs had higher expression of a myostatin-related gene and lower expression of lipolysis-related genes. Additionally, the mitochondrial DNA copy number was higher in the muscle and lower in adipose tissue in lean compared with obese pigs. These results indicate that lean pigs have a distinct development pattern from obese pigs, involving lipogenesis, muscle growth, and energy metabolism. This study provides a basis for exploring the mechanisms of adipose deposition and muscle growth in obesity. Keywords: Obesity, mitochondrial DNA, Sus scrofa

With high kinetic energy and excellent penetration performance, metal jets have been widely used in the defence industry. When a thin plate is impacted by a metal jet with a velocity higher than 3 km/s, debris clouds will be generated at both sides of the plates. However, compared with the debris clouds generated by hypervelocity impact of projectiles, debris clouds generated by hypervelocity jets is rarely observed. In this paper, the utility of ultrahigh-speed simultaneous framing and streak photography technology is applied in the experiment of copper jets impact thin aluminum plates at hypervelocity. Debris clouds and front edges of shock waves are clearly observed and recognized after using newly developed technology to effectively restrain excessive exposure caused by intensive self-illumination in the experiment. From framing and streak pictures, the process of jets impact targets is comprehensively and completely recorded and the velocities of the jet and the debris cloud are obtained using the methods of data processing developed in present paper.

Herein, circularly polarized light is utilized to trigger an enantioselective polymerization reaction, resulting in the synthesis of an optically active polymer from racemic monomers in the absence of any chiral dopant or catalyst.

The procedure for Heuchera villosa ‘Caramel’ propagation was investigated, which involves shoot regeneration, rooting of regenerated shoots, and acclimation of regenerated plantlets. Petioles, as explants, were cultured on MS medium supplemented with 1-naphthylacetic acid (NAA), benzylaminopurine (BA), thidiazuron (TDZ) and callus formed on all media. Shoots were observed to proliferate from callus on media with BA and NAA, whereas no shoots regenerated on media with TDZ and NAA. On media containing 0.5 or 1.0 mg·L−1 BA in combination with NAA, the regenerated shoots showed severe hyperhydricity, whereas on media containing 0.1 mg·L−1 BA in combination with NAA, the regenerated shoots grew normally. The highest shoot induction rate, 90.6%, was obtained on media containing 0.1 mg·L−1 BA and 0.01 mg·L−1 NAA. The effects of indole-3-acetic acid (IAA), indole-3-butyric acid (IBA), and NAA on rooting of H. villosa ‘Caramel’ was explored. The highest rooting rate (95%) was obtained on 1/2 MS medium containing 0.2 mg·L−1 NAA. In the subsequent acclimation experiments, about 85% of rooted plantlets survived and grew normally.

Hygroscopicity largely affects environmental and climatic impacts of pollen grains, one important type of primary biological aerosol particles in the troposphere. However, our knowledge of pollen hygroscopicity is rather limited, and the effect of temperature in particular has rarely been explored before. In this work three different techniques, including a vapor sorption analyzer, diffusion reflectance infrared Fourier transform spectroscopy (DRIFTS) and transmission Fourier transform infrared spectroscopy (transmission FTIR) were employed to characterize six anemophilous pollen species and to investigate their hygroscopic properties as a function of relative humidity (RH, up to 95 %) and temperature (5 or 15, 25 and 37 ∘C). Substantial mass increase due to water uptake was observed for all the six pollen species, and at 25 ∘C the relative mass increase at 90 % RH, when compared to that at  % RH, ranged from ∼30 % to ∼50 %, varying with pollen species. It was found that the modified κ-Köhler equation can well approximate mass hygroscopic growth of all the six pollen species, and the single hygroscopicity parameter (κ) was determined to be in the range of 0.034±0.001 to 0.061±0.007 at 25 ∘C. In situ DRIFTS measurements suggested that water adsorption by pollen species was mainly contributed to by OH groups of organic compounds they contained, and good correlations were indeed found between hygroscopicity of pollen species and the number of OH groups, as determined using transmission FTIR. An increase in temperature would in general lead to a decrease in hygroscopicity, except for pecan pollen. For example, κ values decreased from 0.073±0.006 at 5 ∘C to 0.061±0.007 at 25 ∘C and to 0.057±0.004 at 37 ∘C for Populus tremuloides pollen, and decreased from 0.060±0.001 at 15 ∘C to 0.054±0.001 at 25 ∘C and 0.050±0.002 at 37 ∘C for paper mulberry pollen.

The oil-impregnated paper plays a critical role in the reliability and safety of converter transformer, which is suffered by the accumulation of charges on oil-impregnated paper, leading to distorting the electric field and overvoltage. In addition, the problem of temperature rise is more prominent in contrast with the power transformer, which is attributed to the DC magnetic bias and harmonic current. As a consequence, the performance deterioration of oil-impregnated paper is a comprehensive result from multiple factors including thermal stress and electric field. Surface fluorination has obvious effect on the characteristics of the insulating material based on our previous work. This paper is dedicated to research effects of temperature on the charge characteristic of fluorinated oil-paper insulation under the coupling of DC and pulse voltage. The conclusions can be drawn that The strong electronegativity of fluorine and the tiny voids generated by fluorination contributes to capturing carriers for inhibiting the increase level of carrier mobility. The temperature rise has more influence in modifying the trap depth of the fluorinated paper in contrast with the trap density.

Physical review letters 121(5), 051103 (2018). doi:10.1103/PhysRevLett.121.051103, Published by APS, College Park, Md.

Chinese purple yam (Dioscorea alata) is a kind of yam which is cultivated in different regions of China. It contains high amount of vitamins, minerals, amino acids, and functional components such as mucin, anthocyanins and catechins. Traditionally, yams have been used as Chinese herbal medicines to prevent the diseases of diarrhoea, diabetes and also possess antioxidant and antimutagenic activities. The aim of this study was to identify the major phenolic compounds in Chinese purple yam. From fresh yam, 25 g of sample was blended and extracted with 250 mL 0.01% HCl in methanol (v/v) and stored at 5°C. The analyses were performed on a Shimadzu LCMS-IT-TOF instrument. Six kinds of anthocyanins were tentatively identified, namely cyanidin3-gentiobio-side, alatanin C, cyanidin 3-ferulyl gentiobioside, cyanidin3-sinapylgentianoside, peonidin 3-gentiobioside and alatanin 2. The dominant anthocyanin in Chinese purple yam is alatanin C which accounts for about 46.3% of the total anthocyanins.

Two-dimensional (2D) transition-metal dichalcogenides have emerged as a promising material system for optoelectronic applications, but their primary figure-of-merit, the room-temperature photoluminescence quantum yield (QY) is extremely poor. The prototypical 2D material, MoS 2 is reported to have a maximum QY of 0.6% which indicates a considerable defect density. We report on an air-stable solution-based chemical treatment by an organic superacid which uniformly enhances the photoluminescence and minority carrier lifetime of MoS 2 monolayers by over two orders of magnitude. The treatment eliminates defect-mediated non-radiative recombination, thus resulting in a final QY of over 95% with a longest observed lifetime of 10.8±0.6 nanoseconds. Obtaining perfect optoelectronic monolayers opens the door for highly efficient light emitting diodes, lasers, and solar cells based on 2D materials.

This paper discusses natural attenuation of chlorobenzene (CB) elimination in a deep confined aquifer in a certain test site in China during a groundwater artificial recharge process. Pilot-scale experiments were conducted in laboratory, including adsorption and biodegradation experiments. The results from the adsorption experiments indicated that the adsorption rate increased within the temperature range 0–20 °C. Processes were fitted to the pseudo-first-order and pseudo-second-order kinetic equations, Freundlich and Langmuir models. Maximal amounts of adsorption were 20.747, 21.505 and 23.364 µg/g at 0, 10 and 20 °C, respectively. The adsorption of CB was an endothermic process. The results from the biodegradation experiments indicated that the processes were well fitted by the Monod and first-order decay kinetics equations at different temperatures. It showed that the Monod μ max changed from 0.0314 to 0.0387 h−1, and the half-life (t 1/2) decreased from 3.02 to 1.46 d with an increase in temperature from 0 to 20 °C. The influence of temperature on the biodegradation rate was expressed by the Arrhenius equation. This study provides information on the mechanisms of natural attenuation of CB in the subsurface environment, whilst also providing the necessary technical information for the security of artificial recharge implementation.

Radioactive iodine (RAI) ablation is a beneficial, adjuvant therapy for the management of differentiated thyroid cancer (DTC) after thyroidectomy. The goal of RAI is to destroy remnant thyroid and microscopic cancerous tissue. Radioactive iodine uptake is enhanced by elevating TSH levels and initiating a low iodine diet (LID) prior to ablation. An ideal LID should preferably not exceed 50 mcg/day of dietary iodine for 1-2 weeks, although the duration may be shortened to a week with a structured patient education programme. A pre-ablation spot urinary iodine concentration (UIC) of

Somatic embryogenesis receptor-like kinase (SERK) is a small gene family found in plants. SERK is involved in somatic embryogenesis and can be found in various important signal transduction pathways. Research on SERK found in pineapple (AcSERK1 and AcSERK2) has indicated that these genes could be used as potential marker genes for monitoring the acquisition of embryogenic competence. This experiment was designed to study somatic embryogenesis in pineapple in detail using AcSERK1 as a marker gene. The results showed that somatic embryogenesis in pineapple callus originated from the surface, the inside, and the superficial layer of the callus. Very few parenchyma cells could be converted into competent cells under 2,4-D induction. The competent cells passed through the pro-embryo-protuberance, the pro-embryo, and the early stage globular embryo. The passage of competent cells through these channels formed the globular embryo. AcSERK1 expression was upregulated by jasmonic acid (JA), salicylic acid (SA), injury, and low temperature treatment. The His6-AcSERK1 protein had autophosphorylation activity. These results confirmed that AcSERK1 can be used as a marker gene for the study of embryogenesis and for expression of totipotency in pineapple. The results indicated that AcSERK1 may also play a role in pineapple stress-response signaling. For future studies, the prokaryotically-expressed His6-AcSERK1 protein can be used to examine the receptor-like kinases function of SERK proteins.

In this work, a yeast strain Rhodotorula mucilaginosa WT6-5 that could grow at the pH from 3·0 to 8·0, isolated from tailings soil in Huludao of Liaoning province, China, was investigated with respect to lead ions in aqueous solutions. The effect of initial lead concentration on biosorption quantity is studied at 20, 30, 40 and 50°C, respectively. The experimental results are fitted to the Langmuir and Freundlich model isotherms to obtain the characteristic parameters of each model using non-linear regressive analysis. The maximum biosorption capacity of lead ions onto R. mucilaginosa WT6-5 is 12·1097 mg g−1 at 30°C. For the solution containing 10 mg L−1 Pb2+ at pH 5·0, the maximum absorption rate is reached at 92·75%. The elements of R. mucilaginosa WT6-5 biomass before and after absorption were observed using X-ray fluorescence. The results indicated that Pb2+ biosorption mechanism of R. mucilaginosa WT6-5 is a type of ions exchange and surface complexation.

Oxide-supported metal catalysts were prepared by thermal impregnation of highly crystalline and highly-faceted starting spinels of the form (M0.75Mg0.25)Al2O4, where M = Ni, Co, or Cu and mixtures thereof. In situ reduction at 900 °C extracts the transition metals from the oxide, and the resulting catalysts contain metal crystallites with particle sizes of ~100 nm and exceedingly low dispersion, but show high activity for dry reforming of methane with turnover frequencies as large as 3.9 at 850 °C. The Ni0.375Cu0.375Mg0.25Al2O4 catalyst shows stable methane conversion out to 12 hours on stream without performance-degrading coking. For the Ni/Co catalysts, the reforming activity and sulfur tolerance are both functions of the Ni/Co ratio and the synthesis temperature of the starting spinel, with Ni0.375Co0.375Mg0.25Al2O4 synthesized at 1500 °C displaying fast reaction kinetics even in the presence of 20 ppm H2S. High reforming activity is attributed to long linear lengths of high-perfection facet edges and corners on the metal crystallites. Sulfur tolerance appears to be improved by a combination of the oxygen storage capacity of the defective spinel support and its faceting that provides additional reaction sites for activation of CO2.

Silver, once regarded as a safe noble metal for humans, has been widely used in industrial and commercial products, especially in nanometer biomaterials. It is now well known that Ag

Despite the great progress in the field of mesoporous silica materials, there are few reports on mesoporous spherical silica nanoparticles (MSSNPs) synthesized by hydrolysis and co-condensation of tetraethyl orthosilicate (TEOS) and n-octadecyltrimethoxysilane (C18TMS). Here, we design a facile strategy for the synthesis of MSSNPs using C18TMS as a porogen, and TEOS as a silica precursor in a water–ethanol–ammonia system. Further, we investigate the effects of some synthesis conditions, including synthesis time, reaction temperature and molar ratio of EtOH/H2O on mesostructure. The obtained particles show tunable pore diameter, pore volume and surface area by changing synthesis conditions. Electron microscopy images show a particle size ranging from 100 nm to 200 nm. The N2 adsorption analysis indicates that the maximum Brunauer–Emmett–Teller surface area and Barrett–Joyner–Halanda pore volume up to 1164.9 m2 g−1 and 1.5 cm3 g−1 respectively, and a maximum pore diameter of 4.9 nm.

A new Co(II) coordination complex with the formula [Co(IS)2(H2O)4] (I), where HIS = isoquinoline-5-sulfonic acid, has been synthesized and characterized by single crystal X-ray diffraction, IR spectroscopy, elemental analysis, fluorescence and surface photovoltage spectroscopy (SPS). X-ray diffraction analyses indicated that center Co2+ ion adopts six-coordinated with a N2O4 donors set of the two IS− and four aqua ligands, resulting in an ideal octahedral. Topological analysis on complex I considering {Co(IS)2(H2O)4} as nodes and hydrogen bonds as linkers gives a uninodal ten-connected net bct with point symbol (312 × 428 × 55). In the crystal packing, the components interact with pairs of intermolecular O-H...O hydrogen bonds and π-π stacks forming a 3D supramolecular network. The SPS of I indicates that there are positive response bands in the range of 300–600 nm showing photo-electric conversion properties. The solidstate photoluminescence property of I has also been investigated.