Discovery of novel ocotillol derivatives modulating glucocorticoid receptor/NF-κB signaling for the treatment of sepsis.

Glucocorticoids (GCs) have been used in the treatment of sepsis because of their potent anti-inflammatory effects. However, their clinical efficacy against sepsis remains controversial because of glucocorticoid receptor (GR) downregulation and side effects. Herein, we designed and synthesized 30 ocotillol derivatives and evaluated their anti-inflammatory activities. Ocotillol 24(R/S) differential isomers were stereoselective in their pharmacological action. Specifically, 24(S) derivatives had better anti-inflammatory activity than their corresponding 24(R) derivatives. Compound 20 most effectively inhibited NO release (85.97% reduction), and it exerted dose-dependent inhibitory effects on interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) levels. Mechanistic studies revealed that compound 20 reduces the degradation of GR mRNA and GR protein. Meanwhile, compound 20 inhibited the activation of nuclear factor-κB (NF-κB) signaling, thereby inhibiting the nuclear translocation of p65 and attenuating the inflammatory response. In vivo studies revealed that compound 20 attenuated hepatic, pulmonary, and renal pathology damage in mice with sepsis and suppressed the production of inflammatory mediators. These results indicated that compound 20 is a promising lead compound for designing and developing anti-sepsis drugs.

Nitroaromatic compounds in six major Chinese cities: Influence of different formation mechanisms on light absorption properties.

Nitroaromatic compounds (NACs) are important nitrogen organics in aerosol with strong light-absorbing and chemically reactive properties. In this study, NACs in six Chinese megacities, including Harbin (HB), Beijing (BJ), Xi'an (XA), Wuhan (WH), Chengdu (CD), and Guangzhou (GZ), were investigated for understanding their sources, gas-particle partitioning, and impact on BrC absorption properties. The concentrations of ΣNACs in PM2.5 in the six cities ranged from 9.15 to 158.8 ng/m3 in winter and from 2.02 to 9.39 ng/m3 in summer. Nitro catechols (NCs), nitro phenols (NPs), and nitro salicylic acids (NSAs) are the main components in ΣNACs, with NCs being dominant in particulate phase and NPs being dominant in the gas phase. Correlation analysis between different pollutant species revealed that coal and biomass combustions were the major sources of NACs in the northern cities during wintertime, while secondary formation dominated NACs in the southern cities during summertime. The contribution of ΣNACs to brown carbon (BrC) light absorption ranged from 0.85 to 7.98 % during the wintertime and 2.07-6.44 % during the summertime. The mass absorption efficiency at 365 nm (MAE365) were highest for 4-nitrocatechol (4NC, 17.4-89.0 m2/g), 4-methyl-5-nitrocatechol (4M5NC, 15.0-76.9 m2/g), and 4-nitroguaiacol (4NG, 11.7-59.8 m2/g). The formation of NCs and NG through oxidation and nitration of catechol and guaiacol led to a significant increase in aerosol light absorption. In contrast, NPs and NSAs formed by the photonitration and photooxidation in liquid phase showed high polarity but low light absorption ability, and the proportions of (NPs + NSAs) in the light absorption of ΣNACs were lower than 15.3 % in the six megacities.

New Insights into MeHg Accumulation in Rice (Oryza sativa L.): Evidence from Cysteine.

The intake of methylmercury (MeHg)-contaminated rice poses immense health risks to rice consumers. However, the mechanisms of MeHg accumulation in rice plants are not entirely understood. The knowledge that the MeHg-Cysteine complex was dominant in polished rice proposed a hypothesis of co-transportation of MeHg and cysteine inside rice plants. This study was therefore designed to explore the MeHg accumulation processes in rice plants by investigating biogeochemical associations between MeHg and amino acids. Rice plants and underlying soils were collected from different Hg-contaminated sites in the Wanshan Hg mining area. The concentrations of both MeHg and cysteine in polished rice were higher than those in other rice tissues. A significant positive correlation between MeHg and cysteine in rice plants was found, especially in polished rice, indicating a close geochemical association between cysteine and MeHg. The translocation factor (TF) of cysteine showed behavior similar to that of the TF of MeHg, demonstrating that these two chemical species might share a similar transportation mechanism in rice plants. The accumulation of MeHg in rice plants may vary due to differences in the molar ratios of MeHg to cysteine and the presence of specific amino acid transporters. Our results suggest that cysteine plays a vital role in MeHg accumulation and transportation inside rice plants.

Measurement constrained emission estimates of alkylated polycyclic aromatic hydrocarbons in the Canadian Athabasca oil sands region.

Alkylated polycyclic aromatic hydrocarbons (APAH) are important contaminants of crude oil production and exhibit similar toxicity to their parent compounds. This study developed an emission inventory of APAH in a major oil sands development region of Alberta, Canada, and validated the inventory with ambient concentration measurements through dispersion modeling. The initial estimate of regional total annual emissions of 21 APAH species was 362 tonnes/year in the last decade, of which 309 and 53 tonnes/year were in particle-bound and gas-phase APAH, respectively. Fugitive dust from oil sands mining activities is the primary source of particle-bound APAH, emitting 274 tonnes/year. Other major sources of APAH include point sources (31), tailings ponds (21), anthropogenic fuel consumption from mine fleet (17), and local transportation (13). The group of species with highest emissions was C1-C4 alkylnaphthalenes (53%), followed by C1-C4 alkylphenanthrenes/anthracenes (19%), C1-C4 fluorenes (13%), and C1-C4 fluoranthenes/pyrenes and C1-C4 benz[a]anthracenes/chrysene/triphenylenes (7% each). CALPUFF dispersion modeling was performed using the APAH emissions as model input. The model-predicted annual average ambient APAH concentrations at 17 monitoring sites were 1%-52% (19% on average) lower than the measurements. Inverse dispersion modeling was then applied to adjust APAH emissions higher by 19% for each of the 21 APAH species, which resulted in a revised estimate of APAH emissions to 431 tonnes/year. With the revised emissions as model input, model bias in the predicted ambient concentration was reduced from -19% to -8%. The model results showed the highest concentrations of APAH were near tailings ponds and open mining faces and downwind areas, with total APAH concentrations being higher than 50 ng/m3.

Study on Seepage Characteristics of Grouting Slurry for Water-Absorbing Mudstone with Rough Fissure.

Based on the computed tomography scanning, which abbreviation is CT scanning, and fractal theory, geometric parameters of mudstone fissures are obtained. The physical model of a single fissured channel is obtained in combination with Barton standard curves and 3D printing technology, and similar materials of mudstone are developed based on the water absorption of natural mudstone to prepare single fissured water-absorbing grouting test blocks with different roughness levels for the grouting simulation testing. By analyzing the viscosity change characteristics of grouting slurry before and after grouting, the seepage characteristics of the grouting slurry in the rough fissures of the water-absorbing mudstone are revealed. The results show that when the roughness is small, the grouting slurry will have an obvious water loss effect after passing through mudstone fissures. However, with the flow of the slurry, the water loss effect of the subsequent grouting slurry will be weakened. For fissures with high roughness, the water absorption properties of the rough surfaces and the walls of the mudstone fissures work together, leading to the sedimentation and blockage of the fissure channels, thereby hindering the flow of slurry.

Directing Cell Delivery to Murine Atherosclerotic Aortic Lesions via Targeting Inflamed Circulatory Interface using Nanocarriers.

Stem cell therapy holds significant potential for many inflammatory diseases and regenerative medicine applications. However, delivery of therapeutic cells to specific disease sites after systemic administration without indiscriminate trafficking to other non-target tissues is a major limitation of current cell therapies. Here, we describe a novel nanocarrier-directed targeted cell delivery system that enables cell surface coating with dendrimer nanocarriers containing adhesion moieties to serve as a global positioning system "GPS" to guide circulating cells to targeted lesions and mediate the anchoring of cells at the inflammation site. By exploiting cell surface ligands/receptors selectively and/or molecular moieties that are highly expressed on activated endothelium in pathologic disease states, nanocarrier-coated cells containing the counterpart binding receptors/ligands can be enabled to specifically traffic to and dock at vasculature within target lesions. We demonstrate the efficacy of the I-domain fragment of LFA-1 ( id LFA-1) complexed to modified nanocarriers to facilitate homing of mesenchymal stem cells (MSCs) to inflamed luminal endothelial cells on which ICAM-1 is highly expressed in a murine model of aortic atherosclerosis. Our method can overcome challenges imposed by the high velocity and dynamic circulatory flow of the aorta to successfully deliver MSCs to atherosclerotic regions and allow for docking of the potentially therapeutic and immunomodulating cells. This targeted cell-delivery platform can be tailored for selective systemic delivery of various types of therapeutic cells to different disease areas.

Association between left bundle branch block and ventricular septal mid-wall fibrosis in patients with preserved left ventricular ejection fraction.

BACKGROUND: The left bundle branch block (LBBB) is associated with ventricular septal mid-wall fibrosis (SMF) in patients with dilated cardiomyopathy (DCM). However, whether LBBB is also associated with SMF in patients with preserved left ventricular ejection fraction (LVEF) remains unclear. METHODS: We performed a retrospective study of 210 patients with preserved LVEF (male, n = 116; female, n = 94; mean age, 44 ± 17 years). LBBB was defined as QRS duration ≥140 ms for men or ≥ 130 ms for women, QS or rS in V1-V2, mid-QRS notching or slurring in at least two leads (V1, V2, V5, V6, I, and aVL). SMF determined by late gadolinium-enhancement cardiovascular magnetic resonance was defined as stripe-like or patchy mid-myocardial hyper-enhancement in the interventricular septal segments. RESULTS: SMF was detected in 24.8% (52/210) of these patients. The proportion of patients with SMF with LBBB was higher than the proportion of patients with SMF without LBBB (58.3% vs. 20.4%; P < 0.001). In the forward multivariate logistic analysis, LBBB (OR, 4.399; 95% CI, 1.774-10.904; P = 0.001) and age (OR, 1.028; 95% CI, 1.006-1.051; P = 0.011) were independently associated with SMF. The presence of LBBB showed a sensitivity of 27%%, specificity of 94%, positive predictive value of 58%%, and negative predictive value of 80% for the detection of SMF. CONCLUSION: LBBB was significantly associated with SMF in hospitalized patients with preserved LVEF. Screening with a resting 12­lead ECG may help to identify patients who are at a high risk of the presence of SMF.

Lixisenatide ameliorated lipopolysaccharide (LPS)-induced expression of mucin and inflammation in bronchial epithelial cells.

Chronic obstructive pulmonary disease (COPD) induces serious social and economic burdens due to its high disability and mortality, the pathogenesis of which is highly involved with inflammation, oxidative stress (OS), and mechanism of mucin 5AC (MUC5AC) secretion. Lixisenatide is a selective glucagon-like peptide 1 receptor agonist recently reported to have anti-inflammatory properties. Our study will focus on the potential impact of lixisenatide on lipopolysaccharide (LPS)-induced mucin secretion and inflammation in 16 human bronchial epithelial (16HBE) cells to check its potential function in COPD. 16HBE cells were treated with LPS, with or without lixisenatide (10 and 20 nM) for 1 day. Remarkably declined cell viability, enhanced lactate dehydrogenase release, activated OS, and elevated release of inflammatory cytokines were observed in LPS-treated 16HBE cells, accompanied by the activation of nuclear factor-κB signaling, all of which were signally reversed by lixisenatide. Moreover, elevated expression and release of MUC5AC were observed in LPS-treated 16HBE cells but were markedly repressed by lixisenatide. Furthermore, the repressed nuclear factor erythroid 2-related factor 2 (Nrf2) level in LPS-treated 16HBE cells was notably rescued by lixisenatide. Lastly, following the knockdown of Nrf2, the protective function of lixisenatide on LPS-triggered MUC5AC release in 16HBE cells was significantly abrogated. Collectively, lixisenatide ameliorated LPS-induced expression of mucin and inflammation in bronchial epithelial cells by regulating Nrf2.

Chemical characteristics, distribution patterns, and source apportionment of particulate elements and inorganic ions in snowpack in Harbin, China.

Snowpack, which serves as a natural archive of atmospheric deposition of multiple pollutants, is a practical environmental media that can be used for assessing atmospheric records and input of the pollutants to the surface environments and ecosystems. A total of 29 snowpack samples were collected at 20 sampling sites covering three different functional areas of a major city (Harbin) in Northeast China. Two samples at the "snow layer" and one or two samples at the "particulate layer" were collected at each sampling site in the industrial areas characterized by multi-layer snowpack, and only one sample at the "snow layer" was collected at each sampling site in the cultural and recreational as well as agricultural areas. The snow contents of 31 elements (Na, Mg, Al, K, Ca, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Y, Cd, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Pb) and six major water-soluble inorganic ions (WSIIs, NH4+, K+, Ca2+, NO2-, NO3-, and SO42-) were analyzed. The total mass of the measured elements is dominated (95.8%-99.2%) by crustal elements. Heavy metals only account for 0.77%-4.07% of the total mass of the elements, but are occasionally close to or even above the standard limit in the "Environmental Quality Standards for Surface Water" of China (GB3838-2002). SO42- and Ca2+ are the main anion and cation, accounting for 34.9%-81.1% and 1.43%-29.9%, respectively, of the measured total ions. Total atmospheric deposition of crustal elements and heavy metals is dominated by wet deposition in areas near the petrochemical plant and by dry deposition in areas near the cement plant. Coal combustion, industrial emissions, and traffic-related activities lead to the enrichment of heavy metals in the snowpacks of urban and suburban areas, while coal combustion and biomass burning contribute to pollution in rural areas. The cities and regions situated in the western, northwestern, northern, and northeastern directions from Harbin are potential source regions of these pollutant species.

A single-point modeling approach for the intercomparison and evaluation of ozone dry deposition across chemical transport models (Activity 2 of AQMEII4).

A primary sink of air pollutants and their precursors is dry deposition. Dry deposition estimates differ across chemical transport models, yet an understanding of the model spread is incomplete. Here, we introduce Activity 2 of the Air Quality Model Evaluation International Initiative Phase 4 (AQMEII4). We examine 18 dry deposition schemes from regional and global chemical transport models as well as standalone models used for impact assessments or process understanding. We configure the schemes as single-point models at eight Northern Hemisphere locations with observed ozone fluxes. Single-point models are driven by a common set of site-specific meteorological and environmental conditions. Five of eight sites have at least 3 years and up to 12 years of ozone fluxes. The interquartile range across models in multiyear mean ozone deposition velocities ranges from a factor of 1.2 to 1.9 annually across sites and tends to be highest during winter compared with summer. No model is within 50 % of observed multiyear averages across all sites and seasons, but some models perform well for some sites and seasons. For the first time, we demonstrate how contributions from depositional pathways vary across models. Models can disagree with respect to relative contributions from the pathways, even when they predict similar deposition velocities, or agree with respect to the relative contributions but predict different deposition velocities. Both stomatal and nonstomatal uptake contribute to the large model spread across sites. Our findings are the beginning of results from AQMEII4 Activity 2, which brings scientists who model air quality and dry deposition together with scientists who measure ozone fluxes to evaluate and improve dry deposition schemes in the chemical transport models used for research, planning, and regulatory purposes.

Global trends of targeted therapy for hepatocellular carcinoma: A bibliometric and visualized study from 2008 to 2022.

BACKGROUND: Hepatocellular carcinoma (HCC) is an exceedingly prevalent malignancy with an exceptionally poor prognosis. Targeted therapy is an effective treatment option for patients with advanced HCC. However, there have been no bibliometric analyses of targeted therapies for HCC. METHODS: This study aimed to assess the current status and future directions of targeted therapy for HCC to provide future scholars with clearer research contents and popular themes. Methods: Literature on targeted therapy for HCC from 2008 to 2022 was obtained from the Web of Science (WoS) and assessed using bibliometric methodology. Additionally, the VOS viewer was applied in the visualization study to conduct bibliographic coupling, co-authorship, co-citation, and co-occurrence analyses of publications. RESULTS: A total of 10,779 papers were subsequently selected. Over the past 15 years, there has been a progressive increase in the number of publications on an annualized basis. China released the most publications in the field, whereas the United States had the highest H-index. Cancers published the most papers. Fudan University had the greatest sway in this area. Studies could be divided into 5 clusters: "Gene and expression research," "Mechanism study," "Nanoparticle study," "Targeted drug research," and "Clinical study." CONCLUSIONS: In the upcoming years, more papers on targeted therapy for HCC are expected to be released, demonstrating the potential for this topic to flourish. Particularly, "Clinical study" is the following trendy topic in this field. Other research subfields may likewise exhibit a continuous tendency towards balanced development.

Analysis of risk factors and short-term prognostic factors of arrhythmia in patients infected with mild/moderate SARS-CoV-2 Omicron variant.

Background: Complications, including arrhythmia, following severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection continue to be of concern. Omicron is the mainstream SARS-CoV-2 mutant circulating in mainland China. At present, there are few epidemiological studies concerning the relationship between arrhythmia and Omicron variant infection in mainland China. Objectives: To investigate the risk factors of arrhythmia in patients infected with the SARS-CoV-2 Omicron variant and the factors influencing prognosis. Methods: Data from 192 Omicron infected patients with symptoms of arrhythmia (AH group) and 100 Omicron infected patients without arrhythmia (Control group) were collected. Patients in the AH group were divided into the good and poor prognosis groups, according to the follow-up results 4-6 weeks after infection. The general and clinical data between the AH and Control groups, and between the good and poor prognosis groups were compared. The variables with differences between the groups were included in the multivariate logistic regression analysis, and the quantitative variables were analyzed by receiver operating characteristic curve to obtain their cut-off values. Results: Compared with the control group, the body mass index (BMI), proportion of patients with a history of arrhythmia, proportion of antibiotics taken, heart rate, moderate disease severity, white blood cell (WBC) count, and the aspartate aminotransferase, creatine kinase (CK), CK isoenzyme (CK-MB), myoglobin (Mb), high-sensitive troponin I (hs-cTnI), lymphocyte ratio and high sensitivity C-reactive protein (hs-CRP) levels in the AH group were significantly higher (p < 0.05). In addition, obesity (BMI ≥24 kg/m2), fast heart rate (≥100 times/min), moderate disease severity, and WBC, CK-MB and hs-cTnI levels were independent risk factors of arrhythmia for patients with Omicron infection (p < 0.05), and hs-CRP was a protective factor (p < 0.05). Compared with the good prognosis group, the age, proportion of patients with a history of arrhythmia, heart rate, proportion of moderate disease severity, and hs-CRP, CK, Mb and hs-cTnI levels were significantly higher in the poor prognosis group, while the proportion of vaccination was lower in the poor prognosis group (p < 0.05). Advanced age (≥65 years old), proportion of history of arrhythmia, moderate disease severity, vaccination, and hs-CRP, Mb and cTnI levels were independent factors for poor prognosis of patients with arrhythmia (p < 0.05). Conclusion: The factors that affect arrhythmia and the prognosis of patients infected with Omicron include obesity, high heart rate, severity of the disease, age. history of arrhythmia, WBC, hs-CRP, and myocardial injury indexes, which could be used to evaluate and prevent arrhythmia complications in patients in the future.

Machine learning-based prediction of surgical benefit in borderline resectable and locally advanced pancreatic cancer.

INTRODUCTION: Surgery represents a primary therapeutic approach for borderline resectable and locally advanced pancreatic cancer (BR/LAPC). However, BR/LAPC lesions exhibit high heterogeneity and not all BR/LAPC patients who undergo surgery can derive beneficial outcomes. The present study aims to employ machine learning (ML) algorithms to identify those who would obtain benefits from the primary tumor surgery. METHODS: We retrieved clinical data of patients with BR/LAPC from the Surveillance, Epidemiology, and End Results (SEER) database and classified them into surgery and non-surgery groups based on primary tumor surgery status. To eliminate confounding factors, propensity score matching (PSM) was employed. We hypothesized that patients who underwent surgery and had a longer median cancer-specific survival (CSS) than those who did not undergo surgery would certainly benefit from surgical intervention. Clinical and pathological features were utilized to construct six ML models, and model effectiveness was compared through measures such as the area under curve (AUC), calibration plots, and decision curve analysis (DCA). We selected the best-performing algorithm (i.e., XGBoost) to predict postoperative benefits. The SHapley Additive exPlanations (SHAP) approach was used to interpret the XGBoost model. Additionally, data from 53 Chinese patients prospectively collected was used for external validation of the model. RESULTS: According to the results of the tenfold cross-validation in the training cohort, the XGBoost model yielded the best performance (AUC = 0.823, 95%CI 0.707-0.938). The internal (74.3% accuracy) and external (84.3% accuracy) validation demonstrated the generalizability of the model. The SHAP analysis provided explanations independent of the model, highlighting important factors related to postoperative survival benefits in BR/LAPC, with age, chemotherapy, and radiation therapy being the top three important factors. CONCLUSION: By integrating of ML algorithms and clinical data, we have established a highly efficient model to facilitate clinical decision-making and assist clinicians in selecting the population that would benefit from surgery.

Seasonal variations of mass absorption efficiency of elemental carbon in PM2.5 in urban Guangzhou of South China.

This study investigates seasonal variations of mass absorption efficiency of elemental carbon (MAEEC) and possible influencing factors in urban Guangzhou of South China. Mass concentrations of elemental carbon (EC) and organic carbon (OC) in PM2.5 and aerosol absorption coefficient (bap) at multi-wavelengths were simultaneously measured in four seasons of 2018-2019 at hourly resolution by a semi-continuous carbon analyzer and an aethalometer. Seasonal average mass concentrations of EC were in the range of 1.36-1.70 µgC/m3 with a lower value in summer than in the other seasons, while those of OC were in the range of 4.70-6.49 µgC/m3 with the lowest value in summer and the highest in autumn. Vehicle exhaust from local traffic was identified to be the predominant source of carbonaceous aerosols. The average aerosol absorption Ångström exponents (AAE) were lower than 1.2 in four seasons, indicating EC and bap were closely related with vehicle exhaust. Seasonal MAEEC at 550 nm was 11.0, 8.5, 10.4 and 11.3 m2/g in spring, summer, autumn, and winter, respectively. High MAEEC was related with the high mass ratio of non-carbonaceous aerosols to EC and high ambient relative humidity.

Contributions of the oil sands sources to the ambient concentrations and deposition of particulate elements in the Canadian Athabasca oil sands region.

In this study, model sensitivity tests were conducted to investigate the relative contributions between emission sources of oil sands (OS) activities and other sources to the ambient concentrations and deposition of 29 particulate elements in the Athabasca oil sands region (AOSR) of Canada. Element emission sources from a recently developed emission database were grouped into three source sectors for elements in PM2.5 (OS-Industrial, OS-Dust, and Non-OS) and two source sectors for elements in PM2.5-10 (OS-All and Non-OS). The OS-Dust and OS-Industrial sectors (combined as one sector for PM2.5-10; OS-All) included element sources linked to dust and other industrial activities from the OS activities, respectively, whereas the Non-OS sector included remaining sources in the region, unrelated to the OS activities. The OS-Industrial, OS-Dust, and Non-OS emissions (tonnes/year) of all elements in PM2.5 were 326, 1430, and 562, respectively. The OS-All and Non-OS emissions (tonnes/year) of all elements in PM2.5-10 were 5890 and 2900, respectively. The element concentrations were simulated by the CALPUFF dispersion model. The sum of the domain averaged annual mean concentrations of all elements in PM2.5 and PM2.5-10 from all sources were 57.3 ng/m3 and 30.4 ng/m3, respectively. Except for Co (PM2.5 and PM2.5-10), Sb (PM2.5-10), and Sn (PM2.5-10), major proportions (≥ 59 %) of the ambient concentrations of the individual elements were linked to the OS source sector. Overall, the OS sector was responsible for 78 % and 68 % of the sum of the mean ambient concentrations of all elements in PM2.5 and PM2.5-10, respectively, which are close to the corresponding emission contributions (76 % and 67 %, respectively). Likewise, the bulk proportion (∼74 %) of the sum of the total atmospheric deposition of all elements was also associated with the OS sources. Carcinogenic and non-carcinogenic risks associated with inhalation exposure to airborne elements were below the recommended threshold risk levels.

Synchronous Changes of GPP and Solar-Induced Chlorophyll Fluorescence in a Subtropical Evergreen Coniferous Forest.

Using in situ near-surface observations of solar-induced chlorophyll fluorescence (SIF) and gross primary productivity (GPP) of a subtropical evergreen coniferous forest in southern China, this study analyzed the dynamics of SIF, GPP and their environmental responses, and explored the potential of SIF in characterizing the variation of GPP. The results showed that SIF and GPP have similar diurnal and seasonal variation and both reach the highest value in summer, indicating that the SIF can be applied to indicate the seasonal variation of GPP for the subtropical evergreen co-niferous. With the increase in temporal scale, the correlation between SIF and GPP becomes more linear. The diurnal variations of both SIF and GPP were characterized by photosynthetically active radiation (PAR), the seasonal variations of SIF and GPP were influenced by air temperature (Ta) and PAR. Probably due to the absent of drought stress during the study period, no significant correlation was detected between soil water content (SWC) and either SIF or GPP. With the in-crease in Ta, PAR or SWC, the linear correlation between the SIF and GPP gradually decreased, and when Ta or PAR was relatively higher, the correlation between SIF and GPP become weakly. Further research is still needed to illustrate the relationship between SIF and GPP under drought condition which occurred frequently in this region based on longer observation.

Using Mercury Stable Isotopes to Quantify Bidirectional Water-Atmosphere Hg(0) Exchange Fluxes and Explore Controlling Factors.

In this study, exchange fluxes and Hg isotope fractionation during water-atmosphere Hg(0) exchange were investigated at three lakes in China. Water-atmosphere exchange was overall characterized by net Hg(0) emissions, with lake-specific mean exchange fluxes ranging from 0.9 to 1.8 ng m-2 h-1, which produced negative δ202Hg (mean: -1.61 to -0.03‰) and Δ199Hg (-0.34 to -0.16‰) values. Emission-controlled experiments conducted using Hg-free air over the water surface at Hongfeng lake (HFL) showed negative δ202Hg and Δ199Hg in Hg(0) emitted from water, and similar values were observed between daytime (mean δ202Hg: -0.95‰, Δ199Hg: -0.25‰) and nighttime (δ202Hg: -1.00‰, Δ199Hg: -0.26‰). Results of the Hg isotope suggest that Hg(0) emission from water is mainly controlled by photochemical Hg(0) production in water. Deposition-controlled experiments at HFL showed that heavier Hg(0) isotopes (mean ε202Hg: -0.38‰) preferentially deposited to water, likely indicating an important role of aqueous Hg(0) oxidation played during the deposition process. A Δ200Hg mixing model showed that lake-specific mean emission fluxes from water surfaces were 2.1-4.1 ng m-2 h-1 and deposition fluxes to water surfaces were 1.2-2.3 ng m-2 h-1 at the three lakes. Results from the this study indicate that atmospheric Hg(0) deposition to water surfaces indeed plays an important role in Hg cycling between atmosphere and water bodies.

Trends of inorganic sulfur and nitrogen species at an urban site in western Canada (2004-2018).

A 15-year (2004-2018) record of measurement data of gaseous and particulate sulfur and nitrogen pollutants in air collected at an urban site in Burnaby in western Canada was analyzed for generating their decadal trends using three different methods, including linear regression, Mann-Kendall test and Theil-Sen trend estimator (MK-TS), and ensemble empirical mode decomposition (EEMD). Annual mean concentration of SO2 and SO42- decreased by about 59% and 42%, respectively, during the 15-year period. The slower decreases of SO42- than SO2 were mainly caused by the increased O3 concentration and temperature in spring and summer, which promoted conversion of SO2 to SO42- through gas-phase reaction, and by the increased aerosol pH value and availability of H2O2 in winter, which enhanced aqueous-phase SO42- formation. Accordingly, the sulfur oxidation ratio (SOR) increased by 23% or more in spring, summer, and winter during the 15-year period. Annual mean concentrations of NO2 and NO3- declined by 36% and 38%, respectively, during this period. On seasonal basis, NO3- decreased faster than NO2 in autumn and slower in winter. The non-linear responses of NO3- to NO2 concentration decreases were more evident in winter than the other seasons, partly due to the increased particulate NO3- fraction caused by decreased temperature, increased aerosol pH value, and enhanced NO3- formation caused by increased O3 concentrations. Annual mean concentration of NH3 showed small increases due to stable NH3 emission and reduced conversion of NH3 to NH4+. NH4+ concentration decreased by 51% during the 15-year period. These results suggest that reduced oxidants levels are likely responsible for weakened formation of secondary inorganic aerosols, besides emission reductions for SO2 and NO2.

Combination of Merocel sponge with Lipopolysaccharide to establish rat rhinosinusitis model

Abstract Objective The study aimed to investigate the feasibility of establishing rhinosinusitis model in rats combinated with Lipopolysaccharide (LPS) and merocel sponge. Methods SD (Sprague Dawley) rats that underwent nasal obstruction using Merocel sponge packing, rats with LPS instillation alone, and rats with both nasal obstruction and LPS instillation were used to establish rat models of rhinosinusitis. After the models were established, the nasal symptoms of rats were recorded, the histopathological examination and Transmission Electron Microscopy (TME) of the sinus tissue were performed and the levels of Tumor Necrosis Factor-α (TNF-α), Interleukin-6 (IL-6) in the blood were also analyzed. The expressions of Aquaporin-5 (AQP5), Occludin, Toll-Like Receptor-4 (TLR4), Medullary differentiation factor 88 (MyD88) and phosphorylated (p)-p65 protein were detected by Western blot to evaluate the effect and mechanism of the experimental models. Results We found that compared with the control group and LPS group, the sinusitis symptom scores in the Merocel sponge combined with LPS group were significantly increased; the respiratory epithelia of the maxillary sinus were degenerated, cilia were detached, and even inflammatory cell infiltration occurred; the levels of TNF-α and IL-6 were increased; the expression of AQP5 and Occludin protein was decreased; and the expressions of TLR4, MyD88, and p-p65 protein were increased. Conclusion For the first time, we successfully established a rat rhinosinusitis model using Merocel sponge with LPS and explored the possible mechanism of LPS action.

County-level and monthly resolution multi-pollutant emission inventory for residential solid fuel burning in Fenwei Plain, China.

The Fenwei Plain (FWP) in central China is the fourth largest plain nationwide. This region has experienced severe air pollution during the past decades, largely due to residential solid fuel burning. A regional-scale emission inventory covering multi-pollutants was currently unavailable for this area due to the lack of localized emission factors (EFs) from various sources. In this study, localized EFs derived from previous in situ measurements and detailed county-level activity data were used to develop an emission inventory of particulate and gaseous pollutants for the source sector of five residential solid fuels in the FWP in 2020. Emissions of particulate matter with an aerodynamic diameter of ≤2.5 µm (PM2.5), organic carbon (OC), elemental carbon (EC), ions, polycyclic aromatic hydrocarbons (PAHs), carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), and volatile organic compounds (VOCs) were estimated to be 230-290, 89-160, 20-29, 31-54, 0.93-22, 2100-3600, 64-87, 9.3-12, and 45-92 Gg/yr, respectively. The county-level distribution characteristics differed between pollutant species due to their different EFs and consumption patterns of solid fuels. Shouyang County emitted most for all pollutants (2.66%-4.91% of the region total) except PM2.5 and SO2, for which Xiangfen and Hongtong County emitted the most (2.64% and 2.90%), respectively. Emissions were higher in cold (SO2 during November to January, other pollutants during November to February) than warm months. Uncertainties in this newly developed emission inventory were estimated to be 25.2%-69.8%, much lower than those of existing ones, demonstrating the reliability of this inventory. Gini coefficients indicated that EC, PAHs, NOx, and VOC emissions exhibited evident regional disparities, e.g., Yuncheng and Jinzhong had high pollution levels despite low economic output. Future emission control policies should first focus on developing regions with high pollution in FWP.