Clinical study of neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio in hypertriglyceridemia-induced acute pancreatitis and acute biliary pancreatitis with persistent organ failure.

BACKGROUND: The neutrophil-to-lymphocyte ratio (NLR) and platelet-to-lymphocyte ratio (PLR) are novel inflammatory indicators that can be used to predict the severity and prognosis of various diseases. We categorize acute pancreatitis by etiology into acute biliary pancreatitis (ABP) and hypertriglyceridemia-induced acute pancreatitis (HTGP). AIM: To investigate the clinical significance of NLR and PLR in assessing persistent organ failure (POF) in HTGP and ABP. METHODS: A total of 1450 patients diagnosed with acute pancreatitis (AP) for the first time at Shanxi Bethune Hospital between January 2012 and January 2023 were enrolled. The patients were categorized into two groups according to the etiology of AP: ABP in 530 patients and HTGP in 241 patients. We collected and compared the clinical data of the patients, including NLR, PLR, and AP prognostic scoring systems, within 48 h of hospital admission. RESULTS: The NLR (9.1 vs 6.9, P < 0.001) and PLR (203.1 vs 160.5, P < 0.001) were significantly higher in the ABP group than in the HTGP group. In the HTGP group, both NLR and PLR were significantly increased in patients with severe AP and those with a SOFA score ≥ 3. Likewise, in the ABP group, NLR and PLR were significantly elevated in patients with severe AP, modified computed tomography severity index score ≥ 4, Japanese Severity Score ≥ 3, and modified Marshall score ≥ 2. Moreover, NLR and PLR showed predictive value for the development of POF in both the ABP and HTGP groups. CONCLUSION: NLR and PLR vary between ABP and HTGP, are strongly associated with AP prognostic scoring systems, and have predictive potential for the occurrence of POF in both ABP and HTGP.

Health-Oriented Emission Control Strategy of Energy Utilization and Its Co-CO2 Benefits: A Case Study of the Yangtze River Delta, China.

Reducing air pollutants and CO2 emissions from energy utilization is crucial for achieving the dual objectives of clean air and carbon neutrality in China. Thus, an optimized health-oriented strategy is urgently needed. Herein, by coupling a CO2 and air pollutants emission inventory with response surface models for PM2.5-associated mortality, we shed light on the effectiveness of protecting human health and co-CO2 benefit from reducing fuel-related emissions and generate a health-oriented strategy for the Yangtze River Delta (YRD). Results reveal that oil consumption is the primary contributor to fuel-related PM2.5 pollution and premature deaths in the YRD. Significantly, curtailing fuel consumption in transportation is the most effective measure to alleviate the fuel-related PM2.5 health impact, which also has the greatest cobenefits for CO2 emission reduction on a regional scale. Reducing fuel consumption will achieve substantial health improvements especially in eastern YRD, with nonroad vehicle emission reductions being particularly impactful for health protection, while on-road vehicles present the greatest potential for CO2 reductions. Scenario analysis confirms the importance of mitigating oil consumption in the transportation sector in addressing PM2.5 pollution and climate change.

Comparison of inebilizumab or rituximab in addition to glucocorticoid therapy for neuromyelitis optica spectrum disorders.

AIM: To investigate the short-term efficacy and safety of inebilizumab for neuromyelitis optica spectrum disorders (NMOSD). METHODS: A total of 33 patients with NMOSD treated with inebilizumab (Group INB, n=15) or rituximab (Group RTX, n=18) in addition to high-dose glucocorticoids were included. Both groups underwent hormone shock therapy during the acute phase. Subsequently, Group INB received inebilizumab injections during the remission phase, while Group RTX received rituximab injections. A comparison of aquaporins 4 (AQP4) titer values, peripheral blood B lymphocyte counts, and visual function recovery was conducted before and 8wk after treatment. Additionally, adverse reactions and patient tolerability were analyzed after using inebilizumab treatment regimes. RESULTS: Following inebilizumab treatment, there was a significantly improvement in the visual acuity of NMOSD patients (P<0.05), accompanied by a notable decrease in AQP4 titer values and B lymphocyte ratio (P<0.05). Moreover, inebilizumab treatment showed a partial effect in preventing optic nerve atrophy (P<0.05). However, there were no significant differences in other therapeutic effects compared to rituximab, which has previously demonstrated substantial therapeutic efficacy (P>0.05). Furthermore, inebilizumab exhibited higher safety levels than that of rituximab injections. CONCLUSION: The combination of inebilizumab and high-dose glucocorticoids proves to be effective. In comparison to rituximab injections, inebilizumab displays better tolerance and safety. Moreover, it demonstrates a partial effect in preventing optic nerve atrophy. Thus, it stands as an effective method to reduce the disability rates and improve the daily living ability of patients with NMOSD.

Association of histone modification with the development of schizophrenia.

Schizophrenia, influenced by genetic and environmental factors, may involve epigenetic alterations, notably histone modifications, in its pathogenesis. This review summarizes various histone modifications including acetylation, methylation, phosphorylation, ubiquitination, serotonylation, lactylation, palmitoylation, and dopaminylation, and their implications in schizophrenia. Current research predominantly focuses on histone acetylation and methylation, though other modifications also play significant roles. These modifications are crucial in regulating transcription through chromatin remodeling, which is vital for understanding schizophrenia's development. For instance, histone acetylation enhances transcriptional efficiency by loosening chromatin, while increased histone methyltransferase activity on H3K9 and altered histone phosphorylation, which reduces DNA affinity and destabilizes chromatin structure, are significant markers of schizophrenia.

Electrospun medicated gelatin/polycaprolactone Janus fibers for photothermal-chem combined therapy of liver cancer.

Liver cancer is a common cancer in the world, and core-shell nanoparticles as a commonly used combination therapy for local tumor ablation, have many shortcomings. In this study, photothermal Janus nanofibers were prepared using a electrospinning technology for tumor treatment, and the products were characterized and in vitro photothermal performance investigated. The micromorphology analysis showed that the photothermic agent CuS and electrospun fibers (loaded with CuS and anticancer drug dihydromyricetin) were successfully prepared, with diameters of 11.58 ± 0.27 µm and 1.19 ± 0.01 µm, respectively. Water contact angle and tensile test indicated that the fiber membranes has a certain hydrophilic adhesion and excellent mechanical strength. The fiber membranes has 808 nm near-infrared laser photothermal heating performance and photothermal stability, and it also has a strong response to the laser that penetrates biological tissue. In addition, in vitro cell culture and in vivo implantation study showed that the fiber membranes could kill HepG2 hepatocellular carcinoma cells combined with photothermal-chem and could be enriched in the implantation area, respectively. Hence, the Janus membranes may be a potential cancer treatment material.

Upf2-Mediated Nonsense-Mediated Degradation Pathway Involved in Genetic Compensation of TrpA1 Knockout Mutant Silkworm (Bombyx mori).

Genetic mutations leading to premature termination codons are known to have detrimental effects. Using the Lepidoptera model insect, the silkworm (Bombyx mori), we explored the genetic compensatory response triggered by mutations with premature termination codons. Additionally, we delved into the molecular mechanisms associated with the nonsense-mediated mRNA degradation pathway. CRISPR/Cas9 technology was utilized to generate a homozygous bivoltine silkworm line BmTrpA1-/- with a premature termination. Transcript levels were assessed for the BmTrpA paralogs, BmPyrexia and BmPainless as well as for the essential factors Upf1, Upf2, and Upf3a involved in the nonsense-mediated mRNA degradation (NMD) pathway. Upf2 was specifically knocked down via RNA interference at the embryonic stage. The results comfirmed that the BmTrpA1 transcripts with a 2-base deletion generating a premature termination codon in the BmTrpA1-/- line. From day 6 of embryonic development, the mRNA levels of BmPyrexia, BmPainless, Upf1, and Upf2 were significantly elevated in the gene-edited line. Embryonic knockdown of Upf2 resulted in the suppression of the genetic compensation response in the mutant. As a result, the offspring silkworm eggs were able to hatch normally after 10 days of incubation, displaying a non-diapause phenotype. It was observed that a genetic compensation response does exist in BmTrpA1-/-B. mori. This study presents a novel discovery of the NMD-mediated genetic compensation response in B. mori. The findings offer new insights into understanding the genetic compensation response and exploring the gene functions in lepidopteran insects, such as silkworms.

Methylobacterium nigriterrae sp. nov., isolated from black soil.

An aerobic, Gram-stain-negative, motile rod bacterium, designated as SYSU BS000021T, was isolated from a black soil sample in Harbin, Heilongjiang province, China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that the isolate belongs to the genus Methylobacterium, and showed the highest sequence similarity to Methylobacterium segetis KCTC 62267 T (98.51%) and Methylobacterium oxalidis DSM 24028 T (97.79%). Growth occurred at 20-37℃ (optimum, 28 °C), pH 6.0-8.0 (optimum, pH 7.0) and in the presence of 0% (w/v) NaCl. Polar lipids comprised of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, one unidentified aminolipid and one unidentified polar lipid. The major cellular fatty acids (> 5%) were C18:0 and C18:1 ω7c and/or C18:1 ω6c. The predominant respiratory quinone was Q-10. The genomic G + C content was 68.36% based on the whole genome analysis. The average nucleotide identity (≤ 83.5%) and digital DNA-DNA hybridization (≤ 27.3%) values between strain SYSU BS000021T and other members of the genus Methylobacterium were all lower than the threshold values recommended for distinguishing novel prokaryotic species. Based on the results of phenotypic, chemotaxonomic and phylogenetic analyses, strain SYSU BS000021T represents a novel species of the genus Methylobacterium, for which the name Methylobacterium nigriterrae sp. nov. is proposed. The type strain of the proposed novel species is SYSU BS000021T (= GDMCC 1.3814 T = KCTC 8051 T).

Spatially and Temporally Differentiated NOx and VOCs Emission Abatement Could Effectively Gain O3-Related Health Benefits.

The increasing level of O3 pollution in China significantly exacerbates the long-term O3 health damage, and an optimized health-oriented strategy for NOx and VOCs emission abatement is needed. Here, we developed an integrated evaluation and optimization system for the O3 control strategy by merging a response surface model for the O3-related mortality and an optimization module. Applying this system to the Yangtze River Delta (YRD), we evaluated driving factors for mortality changes from 2013 to 2017, quantified spatial and temporal O3-related mortality responses to precursor emission abatement, and optimized a health-oriented control strategy. Results indicate that insufficient NOx emission abatement combined with deficient VOCs control from 2013 to 2017 aggravated O3-related mortality, particularly during spring and autumn. Northern YRD should promote VOCs control due to higher VOC-limited characteristics, whereas fastening NOx emission abatement is more favorable in southern YRD. Moreover, promotion of NOx mitigation in late spring and summer and facilitating VOCs control in spring and autumn could further reduce O3-related mortality by nearly 10% compared to the control strategy without seasonal differences. These findings highlight that a spatially and temporally differentiated NOx and VOCs emission control strategy could gain more O3-related health benefits, offering valuable insights to regions with severe ozone pollution all over the world.

The safety and short-term effect of mixed approach in laparoscopic right hemicolectomy for right colon cancer compared with middle approach: a retrospective study.

PURPOSE: To investigate whether the mixed approach is a safe and advantageous way to operate laparoscopic right hemicolectomy. METHODS: A retrospective study was performed on 316 patients who underwent laparoscopic right hemicolectomy in our center. They were assigned to the middle approach group (n = 158) and the mixed approach group (n = 158) according to the surgical approaches. The baseline data like gender、age and body mass index as well as the intraoperative and postoperative conditions including operation time, blood loss, postoperative hospital stay and complications were analyzed. RESULTS: There were no significant differences in age, sex, BMI, ASA grade and tumor characteristics between the two groups. Compared with the middle approach group, the mixed approach group was significantly lower in terms of operation time (217.61 min vs 154.31 min, p < 0.001), intraoperative blood loss (73.8 ml vs 37.97 ml, p < 0.001) and postoperative drainage volume. There was no significant difference in the postoperative complications like postoperative anastomotic leakage, postoperative infection and postoperative intestinal obstruction. CONCLUSIONS: Compared with the middle approach, the mixed approach is a safe and advantageous way that can significantly shorten the operation time, reduce intraoperative bleeding and postoperative drainage volume, and does not prolong the length of hospital stay or increase the morbidity postoperative complications.

Rapid hydrolysis of NO2 at High Ionic Strengths of Deliquesced Aerosol Particles.

Nitrogen dioxide (NO2) hydrolysis in deliquesced aerosol particles forms nitrous acid and nitrate and thus impacts air quality, climate, and the nitrogen cycle. Traditionally, it is considered to proceed far too slowly in the atmosphere. However, the significance of this process is highly uncertain because kinetic studies have only been made in dilute aqueous solutions but not under high ionic strength conditions of the aerosol particles. Here, we use laboratory experiments, air quality models, and field measurements to examine the effect of the ionic strength on the reaction kinetics of NO2 hydrolysis. We find that high ionic strengths (I) enhance the reaction rate constants (kI) by more than an order of magnitude compared to that at infinite dilution (kI=0), yielding log10(kI/kI=0) = 0.04I or rate enhancement factor = 100.04I. A state-of-the-art air quality model shows that the enhanced NO2 hydrolysis reduces the negative bias in the simulated concentrations of nitrous acid by 28% on average when compared to field observations over the North China Plain. Rapid NO2 hydrolysis also enhances the levels of nitrous acid in other polluted regions such as North India and further promotes atmospheric oxidation capacity. This study highlights the need to evaluate various reaction kinetics of atmospheric aerosols with high ionic strengths.

Integrated analyses for identification of a three-gene signature associated with Chaihu Shugan San formula for hepatocellular carcinoma treatment.

Chaihu Shugan San (CSS) is a well-known traditional herbal formula that has the potential to ameliorate hepatocellular carcinoma (HCC); however, its mechanism of action remains unknown. Here, we identified the key targets of CSS against HCC and developed a prognostic model to predict the survival of patients with HCC. The effect of CSS plus sorafenib on HCC cell proliferation was evaluated using the MTT assay. LASSO-Cox regression was used to establish a three-gene signature model targeting CSS. Correlations between immune cells, immune checkpoints and risk score were determined to evaluate the immune-related effects of CSS. The interactions between the components and targets were validated using molecular docking and Surface Plasmon Resonance (SPR) assays. CSS and sorafenib synergistically inhibited HCC cell proliferation. Ten core compounds and 224 targets were identified using a drug compound-target network. The prognostic model of the three CSS targets (AKT1, MAPK3 and CASP3) showed predictive ability. Risk scores positively correlated with cancer-promoting immune cells and high expression of immune checkpoint proteins. Molecular docking and SPR analyses confirmed the strong binding affinities of the active components and the target genes. Western blot analysis confirmed the synergistic effect of CSS and sorafenib in inhibiting the expression of these three targets. In conclusion, CSS may regulate the activity of immune-related factors in the tumour microenvironment, reverse immune escape, enhance immune responses through AKT1, MAPK3, and CASP3, and synergistically alleviate HCC. The co-administration of sorafenib with CSS has a strong clinical outlook against HCC.

A probe into the acid deposition mitigation path in China over the last four decades and beyond.

China currently has the highest acid deposition globally, yet research on its status, impacts, causes and controls is lacking. Here, we compiled data and calculated critical loads regarding acid deposition. The results showed that the abatement measures in China have achieved a sharp decline in the emissions of acidifying pollutants and a continuous recovery of precipitation pH, despite the drastic growth in the economy and energy consumption. However, the risk of ecological acidification and eutrophication showed no significant decrease. With similar emission reductions, the decline in areas at risk of acidification in China (7.0%) lags behind those in Europe (20%) or the USA (15%). This was because, unlike Europe and the USA, China's abatement strategies primarily target air quality improvement rather than mitigating ecological impacts. Given that the area with the risk of eutrophication induced by nitrogen deposition remained at 13% of the country even under the scenario of achieving the dual targets of air quality and carbon dioxide mitigation in 2035, we explored an enhanced ammonia abatement pathway. With a further 27% reduction in ammonia by 2035, China could largely eliminate the impacts of acid deposition. This research serves as a valuable reference for China's future acid deposition control and for other nations facing similar challenges.

Transcriptomic and functional analyzes reveal that the brassinosteroid insensitive 1 receptor (OsBRI1) regulates cold tolerance in rice.

Brassinosteroids (BR) play crucial roles in plant development and abiotic stresses in plants. Exogenous application of BR can significantly enhance cold tolerance in rice. However, the regulatory relationship between cold tolerance and the BR signaling pathway in rice remains largely unknown. Here, we characterized functions of the BR receptor OsBRI1 in response to cold tolerance in rice using its loss-of-function mutant (d61-1). Our results showed that mutant d61-1 was less tolerant to cold stress than wild-type (WT). Besides, d61-1 had lower levels than WT for some physiological parameters, including catalase activity (CAT), superoxide dismutase activity (SOD), peroxidase activity (POD), peroxidase activity (PRO), soluble protein, and soluble sugar content, while malondialdehyde content (MDA) and relative electrical conductivity (REC) levels in d61-1 were higher than those in WT plants. These results indicated that the loss of OsBRI1 function resulted in decreased cold tolerance in rice. In addition, we performed RNA sequencing (RNA-seq) of WT and d61-1 mutant under cold stress. Numerous common and unique differentially expressed genes (DEGs) with up- and down-regulation were observed in WT and d61-1 mutant. Some DEGs were expressed to various degrees, even opposite, between CK1 vs. T1 (WT) and CK2 vs. T2 (d61-1). Among these specific DEGs, some typical genes are involved in plant tolerance to cold stress. Through weighted correlation network analysis (WGCNA), 50 hub genes were screened in the turquoise and blue module. Many genes were involved in cold stress and plant hormone, such as Os01g0279800 (BRI1-associated receptor kinase 1 precursor), Os10g0513200 (Dwarf and tiller-enhancing 1, DTE1), Os02g0706400 (MYB-related transcription factor, OsRL3), etc. Differential expression levels of some genes were verified in WT and d61-1 under cold stress using qRT-PCR. These valuable findings and gene resources will be critical for understanding the regulatory relationships between cold stress tolerance and the BR signaling pathways in rice.

Unpacking the factors contributing to changes in PM2.5-associated mortality in China from 2013 to 2019.

From 2013 to 2019, a series of air pollution control actions significantly reduced PM2.5 pollution in China. Control actions included changes in activity levels, structural adjustment (SA) policy, energy and material saving (EMS) policy, and end-of-pipe (EOP) control in several sources, which have not been systematically studied in previous studies. Here, we integrate an emission inventory, a chemical transport model, a health impact assessment model, and a scenario analysis to quantify the contribution of each control action across a range of major emission sources to the changes in PM2.5 concentrations and associated mortality in China from 2013 to 2019. Assuming equal toxicity of PM2.5 from all the sources, we estimate that PM2.5-related mortality decreased from 2.52 (95 % confidence interval, 2.13-2.88) to 1.94 (1.62-2.24) million deaths. Anthropogenic emission reductions and declining baseline incidence rates significantly contributed to health benefits, but population aging partially offset their impact. Among the major sources, controls on power plants and industrial boilers were responsible for the highest reduction in PM2.5-related mortality (∼80 %), followed by industrial processes (∼40 %), residential combustion (∼40 %), and transportation (∼30 %). However, considering the potentially higher relative risks of power plant PM2.5, the adverse effects avoided by their control could be ∼2.4 times the current estimation. Our power plant sensitivity analyses indicate that future estimates of source-specific PM2.5 health effects should incorporate variations in individual source PM2.5 effect coefficients when available. As for the control actions, while activity levels increased for most sources, SA policy significantly reduced the emissions in residential combustion and industrial boilers, and EOP control dominated the contribution in health benefits in most sources except residential combustion. Considering the emission reduction potential by source and control actions in 2019, our results suggest that promoting clean energy in residential combustion and enforcing more stringent EOP control in the iron and steel industry should be prioritized in the future.

UBC9-mediated SUMOylation of Lamin B1 enhances DNA-damage-induced nuclear DNA leakage and autophagy after spinal cord injury.

Recent studies have shown that nucleophagy can mitigate DNA damage by selectively degrading nuclear components protruding from the nucleus. However, little is known about the role of nucleophagy in neurons after spinal cord injury (SCI). Western blot analysis and immunofluorescence were performed to evaluate the nucleophagy after nuclear DNA damage and leakage in SCI neurons in vivo and NSC34 expression in primary neurons cultured with oxygen-glucose deprivation (OGD) in vitro, as well as the interaction and colocalization of autophagy protein LC3 with nuclear lamina protein Lamin B1. The effect of UBC9, a Small ubiquitin-related modifier (SUMO) E2 ligase, on Lamin B1 SUMOylation and nucleophagy was examined by siRNA transfection or 2-D08 (a small-molecule inhibitor of UBC9), immunoprecipitation, and immunofluorescence. In SCI and OGD injured NSC34 or primary cultured neurons, neuronal nuclear DNA damage induced the SUMOylation of Lamin B1, which was required by the nuclear Lamina accumulation of UBC9. Furthermore, LC3/Atg8, an autophagy-related protein, directly bound to SUMOylated Lamin B1, and delivered Lamin B1 to the lysosome. Knockdown or suppression of UBC9 with siRNA or 2-D08 inhibited SUMOylation of Lamin B1 and subsequent nucleophagy and protected against neuronal death. Upon neuronal DNA damage and leakage after SCI, SUMOylation of Lamin B1 is induced by nuclear Lamina accumulation of UBC9. Furthermore, it promotes LC3-Lamin B1 interaction to trigger nucleophagy that protects against neuronal DNA damage.

New cassane-type alkaloids and diterpenoids from the pericarps of Caesalpinia bonduc.

The phytochemical investigation of the pericarps of Caesalpinia bonduc led to the isolation and identification of five new cassane-type alkaloids: caesalminines C - G (1-5) and six new diterpenoids: caesalbonducin K - P (6-11), along with seven known compounds (12-18). Compounds 1-5 were identified as a group of rare alkaloids possessing a tetracyclic cassane-type diterpenoid skeleton with a lactam D-ring instead of a typical furan or lactone moiety. The structures of 1-11 were elucidated on the basis of 1D and 2D NMR including HSQC, HMBC, COSY and NOESY, and other spectroscopic analyses. The cytotoxic activities of the isolated compounds were evaluated in the A431, A549 and U87MG cancer cell lines.

Factors Associated with Re-Displacement after Nonsurgical Treatment of Distal Radius Fractures in Adults: A Retrospective Study.

OBJECTIVE: Closed reduction combined with external fixation is a frequently utilized approach for treating distal radial fractures in adults. Nonetheless, the potential for re-displacement following external fixation remains. Analyzing the factors influencing re-displacement after nonsurgical treatment of distal radial fractures in adults is vital for preventing re-displacement and making prognostic assessments. METHODS: A retrospective analysis was performed on 884 patients who underwent nonsurgical treatment for distal radius fractures in the reduction room of the Orthopedics and Traumatology Department of Integrated Traditional Chinese and Western Medicine at Tianjin Hospital, Tianjin, China, between July 2019 and December 2022. Patients were categorized into two groups, namely displaced and nondisplaced, based on radiographic outcomes. Factors affecting fracture re-displacement were examined, including sex, age, side, AO/OTA type, external fixation, and radiographic outcomes at pre-reduction and immediate reduction. Logistic regression analysis was employed to identify the risk factors for fracture re-displacement, and ROC curves were constructed. RESULTS: Among the 884 patients, 563 (63.69%) experienced re-displacement after fracture reduction. There were no statistically significant differences (p > 0.05) between the two groups in terms of gender, external fixation method, and palmar tilt angle at pre-reduction and immediate reduction, while significant differences (p < 0.05) were observed in age, side, AO/OTA type, and radial inclination, radial length, and radiographic outcomes of ulnar variance at pre-reduction and immediate reduction. Multifactorial logistic regression analysis revealed that age (odds ratio [OR] = 1.027, p < 0.001), AO/OTA type (OR = 2.327, p = 0.005), ulnar variance at pre-reduction (OR = 1.142, p = 0.048), and ulnar variance at immediate reduction (OR = 1.685, p < 0.001) were significant factors (p < 0.05) associated with re-displacement following nonoperative treatment of adult distal radius fractures. For patients aged ≥60 years, the amount of missing radiographic outcomes was positively correlated with age. The receiver operating characteristic curve demonstrated that age ≥65.5 years, ulnar variance >3.26 mm at pre-reduction, and ulnar variance >2.055 mm at immediate reduction were high-risk factors for fracture re-displacement. CONCLUSIONS: Nonsurgical treatment of distal radius fractures exhibits a higher rate of re-displacement. Age, AO/OTA type, pre-reduction, and immediate reduction ulnar variance are key factors predicting fracture re-displacement.

[Effect of Biomass Burning on Carbonaceous Aerosol Composition and Light Absorption in Guangxi Regional Background Site].

Carbonaceous aerosols are an important component of fine particulate matter (PM2.5) in the atmosphere, having great impacts on air quality, human health, and the climate. In this study, PM2.5 samples were collected from November 2017 to October 2018 in a background site of Guangxi Province to investigate the potential impacts of biomass burning, an essential source of carbonaceous aerosols, on carbonaceous aerosols. Further, the composition of carbonaceous aerosols, sugar compounds, and the light absorption coefficient (babs) of water-soluble brown carbon (BrC) were also conducted. Considering the effect of the degradation of atmospheric levoglucosan (LG), the concentration of the corrected LG was quantified using the aging of air masses (AAM) index. Then, the contribution of biomass burning (BB) to organic carbon (OC) [BB-OC] was quantified using the corrected LG-derived molecular tracer method combined with the Bayesian mixing model. Here, we further explored the potential sources of water-soluble BrC using correlation analysis. In this research, the mean AAM index was 0.40±0.28 during the study period, indicating that the atmospheric LG had undergone a photochemical degradation process. The characteristic ratio combined with the Bayesian mixing model indicated that the crop straw (i.e., corn, rice, and sugarcane straw) was the dominant biomass fuel type in the Guangxi Region, contributing 22%, 23%, and 18% of OC without the correction of LG and 16%, 21%, and 17% with the corrected LG concentration, respectively. The neglection of LG degradation led to the underestimation of BB-OC, in which the BB-OC values with and without correction were 49.0% and 21.1%, respectively. Here, the annual mean babs of water-soluble BrC was (8.7±10.7) Mm-1, and its main sources were BB, fossil fuel combustion, and vegetation emission.