Comparison of the efficacy of costoclavicular space brachial plexus blockade with 0.5% versus 0.375% ropivacaine: a randomized, double-blind, single-centre, noninferiority clinical trial.

PURPOSE: Recently, more attention has been given to the costoclavicular space (CCS) as an alternative pathway for ultrasound-guided brachial plexus block (BPB). While 0.5% ropivacaine was used in most related studies, research has shown effective ultrasound-guided supraclavicular BPB using lower local anesthetic concentrations, and our preliminary data have indicated that 0.375% ropivacaine may be effective when given in the CCS. Hence, we hypothesized that the efficacy of 0.375% ropivacaine would be noninferior compared with 0.5% in ultrasound-guided BPB via the CCS. METHODS: We conducted a randomized, double-blind, single-centre, noninferiority clinical trial. Seventy patients undergoing elective forearm or hand surgery were randomly assigned to receive either 20 mL of 0.375% ropivacaine (experimental group) or 0.5% ropivacaine (control group) in the CCS for BPB. We assessed sensory and motor blockade at five, ten, 15, 20, 25, and 30 min after the injection. The primary outcome was the rate of successful BPB. Secondary outcomes included onset time, duration of sensory and motor blockade, and adverse reactions. The depth from the skin to the CCS was also recorded during the procedure. RESULTS: A total of 69 patients were evaluable for block success. There was one failed block in both groups, yielding a BPB block success rate of 97% in both groups. 0.375% Ropivacaine was noninferior to 0.5% ropivacaine (P = 0.98). There was no significant difference in the median [interquartile range (IQR)] onset time of sensory-motor blockade in the experimental group (15 [15-20] min; N = 34) compared with the control group (15 [13-20] min; N = 33; Mann-Whitney test, P = 0.48). The median [IQR] duration of sensory blockade was significantly shorter in the experimental group (455 [398-490] min vs 610 [570-655] min in the control group; Hodges-Lehmann estimator of the difference, 165 min; 95.08% confidence interval (CI), 130 to 195; P < 0.001). Likewise, the median [IQR] duration of motor blockade was significantly shorter in the experimental group (470 [409-500] min vs 625 [578-665] min in the control group; Hodges-Lehmann estimator of the difference, 165 min; 95.08% CI, 130 to 195; P < 0.001). There were no adverse reactions directly related to the technique or the ropivacaine injection in either group. CONCLUSIONS: 0.375% Ropivacainewas noninferior to 0.5% ropivacaine with regard to rate of successful ultrasound-guided costoclavicular BPB. STUDY REGISTRATION: chictr.org.cn (ChiCTR20000306570); registered 8 March 2020.

RéSUMé: OBJECTIF: L'espace costo-claviculaire (ECC) a récemment bénéficié d'un regain d'intérêt comme voie de substitution pour le bloc du plexus brachial (BPB) échoguidé. La ropivacaïne 0,5 % a été utilisée dans la majorité des études sur ce sujet, mais la recherche a montré un BPB supra-claviculaire échoguidé efficace en utilisant de plus faibles concentrations d'anesthésique local et nos données préliminaires ont indiqué que la ropivacaïne à 0,375 % pouvait être efficace en administration dans l'ECC. En conséquence, nous avons émis l'hypothèse selon laquelle l'efficacité de la ropivacaïne 0,375 % serait non inférieure à la ropivacaïne 0,5 % dans le BPB échoguidé via l'ECC. MéTHODES: Nous avons mené un essai clinique monocentrique de non-infériorité, randomisée en double insu. Soixante-dix patients subissant une chirurgie élective de l'avant-bras ou de la main ont été randomisés dans un groupe recevant 20 mL de ropivacaïne 0,375 % (groupe expérimental) ou de ropivacaïne 0,5 % (groupe contrôle) dans l'ECC pour un BPB. Nous avons évalué les blocs sensoriel et moteur à 5, 10, 15, 20, 25 et 30 minutes après l'injection. Le critère d'évaluation principal était le taux de succès du BPB. Les critères d'évaluation secondaires étaient, notamment, le délai d'action, la durée des blocs sensoriel et moteur, et les événements indésirables. La profondeur de la peau à l'ECC a aussi été consignée pendant la procédure. RéSULTATS: Un total de 69 patients était évaluable pour le succès du bloc. Il y a eu un échec du bloc dans chacun des deux groupes, ramenant le taux de succès du BPB à 97 % dans les deux groupes. La ropivacaïne 0,375 % a été non inférieure à la ropivacaïne 0,5 % (P = 0,98). Il n'y a pas eu de différence significative concernant le délai d'action médian (plage interquartile [PIQ]) du bloc sensori-moteur dans le groupe expérimental (15 [15 à 20] minutes; n = 34) comparativement au groupe contrôle (15 [13 à 20] minutes; n = 33; test de Mann­Whitney, P = 0,48). La durée médiane [PIQ] du bloc sensitif a été significativement plus courte dans le groupe expérimental (455 [398 à 490] minutes contre 610 [570 à 655] minutes dans le groupe contrôle; estimateur de la différence de Hodges­Lehmann, 165 minutes; intervalle de confiance [IC] à 95,08 % : 130 à 195; P < 0,001). De même, la durée médiane [PIQ] du bloc moteur a été significativement plus courte dans le groupe expérimental (470 [409 à 500] minutes contre 625 [578 à 665] minutes dans le groupe contrôle; estimateur de la différence de Hodges­Lehmann, 165 minutes; IC à 95,08 %, 130 à 195; P < 0,001). Il n'y a pas eu d'événement indésirable directement lié à la technique ou à l'injection de ropivacaïne dans l'un ou l'autre groupe. CONCLUSIONS: La ropivacaïne 0,375 % a été non inférieure à la ropivacaïne 0,5 % en ce qui concerne le taux de succès du BPB costo-claviculaire échoguidé. ENREGISTREMENT DE L'éTUDE: chictr.org.cn (ChiCTR20000306570); Enregistrée le 8 mars 2020.

Chemical signature and fractionation of trace elements in fine particles from anthropogenic and natural sources.

The health effects of trace metal elements in atmospheric fine particulate matter (PM2.5) are widely recognized, however, the emission factor profiles and chemical fractionation of metal elements in different sources were poorly understand. In this study, sixteen metal elements, including Cd, Pb, V, Zn, Ba, Sb, As, Fe, Sr, Cr, Rb, Co, Mn, Cu, Ni and Sn from biomass burning, bituminite and anthracite combustion, as well as dust, were quantified. The results show different emission sources were associated with distinct emission profiles, holding important implications for source apportionment of ambient particulate metals. Specifically, Fe was the dominant metal species (28-1922 mg/kg) for all samples, and was followed by different metals for different samples. For dust, Mn (39.9 mg/kgdust) had the second-highest emission factor, while for biomass burning, it was Cr and Ba (7.5 and 7.4 mg/kgbiomass, respectively). For bituminous coal combustion, the emission factor of Zn and Ba was 6.2 and 6.0 mg/kgbituminous, respectively, while for anthracite combustion the corresponding emission factor was 5.6 and 4.3 mg/kganthracite, respectively. Moreover, chemical fractionation (i.e., the exchangeable, reducible fraction, oxidizable, and residual fraction) and the bioavailability index (BI) values of the metal elements from different sources were further investigated to reveal the link between different emission sources and the potential health risk. The findings from this study hold important implications for source apportionment and source-specific particulate metal-associated health effects.

Preactivation of Notch1 in remote ischemic preconditioning reduces cerebral ischemia-reperfusion injury through crosstalk with the NF-κB pathway.

BACKGROUND: Remote ischemic preconditioning (RIPC) initiates endogenous protective pathways in the brain from a distance and represents a new, promising paradigm in neuroprotection against cerebral ischemia-reperfusion (I/R) injury. However, the underlying mechanism of RIPC-mediated cerebral ischemia tolerance is complicated and not well understood. We reported previously that preactivation of Notch1 mediated the neuroprotective effects of cerebral ischemic preconditioning in rats subjected to cerebral I/R injury. The present study seeks to further explore the role of crosstalk between the Notch1 and NF-κB signaling pathways in the process of RIPC-induced neuroprotection. METHODS: Middle cerebral artery occlusion and reperfusion (MCAO/R) in adult male rats and oxygen-glucose deprivation and reoxygenation (OGD/R) in primary hippocampal neurons were used as models of I/R injury in vivo and in vitro, respectively. RIPC was induced by a 3-day procedure with 4 cycles of 5 min of left hind limb ischemia followed by 5 min of reperfusion each day before MCAO/R. Intracerebroventricular DAPT injection and sh-Notch1 lentivirus interference were used to inhibit the Notch1 signaling pathway in vivo and in vitro, respectively. After 24 h of reperfusion, neurological deficit scores, infarct volume, neuronal apoptosis, and cell viability were assessed. The protein expression levels of NICD, Hes1, Phospho-IKKα/ß (p-IKK α/ß), Phospho-NF-κB p65 (p-NF-κB p65), Bcl-2, and Bax were assessed by Western blotting. RESULTS: RIPC significantly improved neurological scores and reduced infarct volume and neuronal apoptosis in rats subjected to I/R injury. OGD preconditioning significantly reduced neuronal apoptosis and improved cell viability after I/R injury on days 3 and 7 after OGD/R. However, the neuroprotective effect was reversed by DAPT in vivo and attenuated by Notch1-RNAi in vitro. RIPC significantly upregulated the expression of proteins related to the Notch1 and NF-κB pathways. NF-κB signaling pathway activity was suppressed by a Notch1 signaling pathway inhibitor and Notch1-RNAi. CONCLUSIONS: The neuroprotective effect of RIPC against cerebral I/R injury was associated with preactivation of the Notch1 and NF-κB pathways in neurons. The NF-κB pathway is a downstream target of the Notch1 pathway in RIPC and helps protect focal cerebral I/R injury.

Comprehensive analysis of non-small-cell lung cancer microarray datasets identifies several prognostic biomarkers.

Aim: To find accurate and effective biomarkers for diagnosis of non-small-cell lung cancer (NSCLC) patients. Materials & methods: We downloaded microarray datasets GSE19188, GSE33532, GSE101929 and GSE102286 from the database of Gene Expression Omnibus. We screened out differentially expressed genes (DEGs) and miRNAs (DEMs) with GEO2R. We also performed analyses for the enrichment of DEGs' and DEMs' function and pathway by several tools including database for annotation, visualization and integrated discovery, protein-protein interaction and Kaplan-Meier-plotter. Results: Total 913 DEGs were screened out, among which ten hub genes were discovered. All the hub genes were linked to the worsening overall survival of the NSCLC patients. Besides, 98 DEMs were screened out. MiR-9 and miR-520e were the most significantly regulated miRNAs. Conclusion: Our results could provide potential targets for the diagnosis and treatment of NSCLC.

Brown Carbon Aerosol in Urban Xi'an, Northwest China: The Composition and Light Absorption Properties.

Light-absorbing organic carbon (i.e., brown carbon or BrC) in the atmospheric aerosol has significant contribution to light absorption and radiative forcing. However, the link between BrC optical properties and chemical composition remains poorly constrained. In this study, we combine spectrophotometric measurements and chemical analyses of BrC samples collected from July 2008 to June 2009 in urban Xi'an, Northwest China. Elevated BrC was observed in winter (5 times higher than in summer), largely due to increased emissions from wintertime domestic biomass burning. The light absorption coefficient of methanol-soluble BrC at 365 nm (on average approximately twice that of water-soluble BrC) was found to correlate strongly with both parent polycyclic aromatic hydrocarbons (parent-PAHs, 27 species) and their carbonyl oxygenated derivatives (carbonyl-OPAHs, 15 species) in all seasons ( r2 > 0.61). These measured parent-PAHs and carbonyl-OPAHs account for on average ∼1.7% of the overall absorption of methanol-soluble BrC, about 5 times higher than their mass fraction in total organic carbon (OC, ∼0.35%). The fractional solar absorption by BrC relative to element carbon (EC) in the ultraviolet range (300-400 nm) is significant during winter (42 ± 18% for water-soluble BrC and 76 ± 29% for methanol-soluble BrC), which may greatly affect the radiative balance and tropospheric photochemistry and therefore the climate and air quality.

Source-Specific Health Risk Analysis on Particulate Trace Elements: Coal Combustion and Traffic Emission As Major Contributors in Wintertime Beijing.

Source apportionment studies of particulate matter (PM) link chemical composition to emission sources, while health risk analyses link health outcomes and chemical composition. There are limited studies to link emission sources and health risks from ambient measurements. We show such an attempt for particulate trace elements. Elements in PM2.5 were measured in wintertime Beijing, and the total concentrations of 14 trace elements were 1.3-7.3 times higher during severe pollution days than during low pollution days. Fe, Zn, and Pb were the most abundant elements independent of the PM pollution levels. Chemical fractionation shows that Pb, Mn, Cd, As, Sr, Co, V, Cu, and Ni were present mainly in the bioavailable fraction. Positive matrix factorization was used to resolve the sources of particulate trace elements into dust, oil combustion, coal combustion, and traffic-related emissions. Traffic-related emission contributed 65% of total mass of the measured elements during low pollution days. However, coal combustion dominated (58%) during severe pollution days. By combining element-specific health risk analyses and source apportionment results, we conclude that traffic-related emission dominates the health risks by particulate trace elements during low pollution days, while coal combustion becomes equally or even more important during moderate and severe pollution days.

Characterization of Primary Organic Aerosol from Domestic Wood, Peat, and Coal Burning in Ireland.

An aerosol chemical speciation monitor (ACSM) was deployed to study the primary nonrefractory submicron particulate matter emissions from the burning of commercially available solid fuels (peat, coal, and wood) typically used in European domestic fuel stoves. Organic mass spectra (MS) from burning wood, peat, and coal were characterized and intercompared for factor analysis against ambient data. The reference profiles characterized in this study were used to estimate the contribution of solid fuel sources, along with oil combustion, to ambient pollution in Galway, Ireland using the multilinear engine (ME-2). During periods influenced by marine air masses, local source contribution had dominant impact and nonsea-spray primary organic emissions comprised 88% of total organic aerosol mass, with peat burning found to be the greatest contributor (39%), followed by oil (21%), coal (17%), and wood (11%). In contrast, the resolved oxygenated organic aerosol (OOA) dominated the aerosol composition in continental air masses, with contributions of 50%, compared to 12% in marine air masses. The source apportionment results suggest that the use of domestic solid fuels (peat, wood, and coal) for home heating is the major source of evening and night-time particulate pollution events despite their small use.

Study on the Ultrahigh Quantum Yield of Fluorescent P,O-g-C3 N4 Nanodots and its Application in Cell Imaging.

Graphitic carbon nitride nanodots (g-C3 N4 nanodots), as a new kind of heavy-metal-free quantum dots, have attracted considerable attention because of their unique physical and chemical properties. Although various methods to obtain g-C3 N4 nanodots have been reported, it is still a challenge to synthesize g-C3 N4 nanodots with ultrahigh fluorescence quantum yield (QY). In this study, highly fluorescent phosphorus/oxygen-doped graphitic carbon nitride (P,O-g-C3 N4 ) nanodots were prepared by chemical oxidation and hydrothermal etching of bulk P-g-C3 N4 derived from the pyrolysis of phytic acid and melamine. The as-prepared P,O-g-C3 N4 nanodots showed strong blue fluorescence and a relatively high QY of up to 90.2 %, which can be ascribed to intrinsic phosphorus/oxygen-containing groups, and surface-oxidation-related fluorescence enhancement. In addition, the P,O-g-C3 N4 nanodots were explored for cell imaging with excellent stability and biocompatibility, which suggest that they have great potential in biological applications.

Zebrafish as a model for studying the developmental neurotoxicity of propofol.

Anesthetics can cause widespread apoptotic neurodegeneration and adverse effects on synaptogenesis during early postnatal life. Synaptogenesis correlates with several proteins, including myelin basic protein (MBP). However, little is known about the adverse effects of exposure to propofol on MBP, particularly during embryonic development. Our goal was to use zebrafish to explore the effect of propofol on embryonic development, apoptosis and MBP expression. Zebrafish embryos were exposed to propofol at defined doses and stages from 6 to 48 h postfertilization by immersion. The survival rate, hatchability, aberration rate, cell apoptosis and gene expression were analyzed at defined stages. Analysis revealed that doses of 1, 2 and 3 µg ml(-1) propofol were reasonable anesthetic concentrations for zebrafish embryos. These doses of propofol caused a significant decrease in hatchability and an increase in aberration rate. Moreover, 6 days postfertilization (dpf) larvae are anesthetized by immersion into water containing 1, 2 or 3 µg ml(-1) of propofol. The number of apoptotic cells in the head of propofol-treated 36 h postfertilization embryos were significantly increased, and the expression of caspases-3, -8 and -9 were upregulated. Apoptosis was also induced in the brain of 3 dpf larvae exposed to propofol. However, propofol caused a decrease in mbp gene and protein (dose-dependent) expression levels in the central nervous system of 3 dpf zebrafish. These data show that embryonic exposure to propofol is neurotoxic, causing increased apoptosis and decreased MBP expression. We believe zebrafish can be used as a novel model to explore the mechanisms of propofol neurotoxicity.

Lutein protects against ischemia/reperfusion injury in rat skeletal muscle by modulating oxidative stress and inflammation.

BACKGROUND: Lutein is an antioxidant compound with potential biological effects. The present study investigated the protective role of Lutein against I/R injury in skeletal muscle. METHODS: Animals were divided into three groups. Group I - sham operated; Group II- IR injury- Hind limb ischemia was induced by clamping the common femoral artery and vein. After 4 h of ischemia, the clamp was removed and the animals underwent 2 h of reperfusion. Group III-Lutein + IR injury- Rats with Lutein treatment received intraperitoneal injection 1 h before reperfusion. The skeletal tissues were analyzed for oxidative stress parameters (reactive oxygen species, protein carbonylation and sulfhydryls, lipid peroxidation). Antioxidant status was determined by evaluating Nrf-2 levels and antioxidant enzyme activities. The inflammatory mechanism was determined through NF-κB and COX-2 expressions. Pro-inflammatory cytokines were determined by ELISA. RESULTS: The results showed that Lutein treatment significantly decreased the oxidative stress by reducing reactive oxygen species, protein carbonylation and sulphydryls, lipid peroxidation. Further, the levels of Nrf-2 and antioxidant status was significantly declined during IR injury compared to sham operated rats. Lutein treatment reduced the oxidative stress by enhancing Nrf-2 levels and antioxidant status. Skeletal IR injury enhanced the inflammatory signaling by up regulating NF-κB, COX-2 and various pro-inflammatory cytokines. NF-κB, COX-2 expressions were down regulated by Lutein treatment. CONCLUSION: The study shows that Lutein protects against skeletal IR injury by down regulating oxidative stress and inflammatory mechanisms.

Label-free fluorescence strategy for sensitive detection of adenosine triphosphate using a loop DNA probe with low background noise.

A simple, rapid, label-free, and ultrasensitive fluorescence strategy for adenosine triphosphate (ATP) detection was developed using a loop DNA probe with low background noise. In this strategy, a loop DNA probe, which is the substrate for both ligation and digestion enzyme reaction, was designed. SYBR green I (SG I), a double-stranded specific dye, was applied for the readout fluorescence signal. Exonuclease I (Exo I) and exonuclease III (Exo III), sequence-independent nucleases, were selected to digest the loop DNA probe in order to minimize the background fluorescence signal. As a result, in the absence of ATP, the loop DNA was completely digested by Exo I and Exo III, leading to low background fluorescence owing to the weak electrostatic interaction between SG I and mononucleotides. On the other hand, ATP induced the ligation of the nicking site, and the sealed loop DNA resisted the digestion of Exo I and ExoIII, resulting in a remarkable increase of fluorescence response. Upon background noise reduction, the sensitivity of the ATP determination was improved significantly, and the detection limitation was found to be 1.2 pM, which is much lower than that in almost all the previously reported methods. This strategy has promise for wide application in the determination of ATP.

Proteomic profiling of the phosphoproteins in the rat thalamus, hippocampus and frontal lobe after propofol anesthesia.

BACKGROUND: Propofol is a safe and effective intravenous anesthetic that is widely used for the induction and maintenance of anesthesia during surgery. However, the mechanism by which propofol exerts its anesthetic effect remains unknown. The rapid onset of phosphorylation modifications coincides with that of propofol anesthesia. METHODS: Propofol-anesthetized rat models were built and phosphorylated proteins in the thalamus, hippocampus and frontal lobe were enriched the to analyze the changes in these phosphoproteins after propofol anesthesia. RESULTS: Sixteen of these phosphoprotein spots were successfully identified using MALDI-TOF MS and a subsequent comparative sequence search in the Mascot database. Of these proteins, keratin 18 and the tubulin 2c chain are cytoskeletal proteins; keratin 18 and gelsolin are relevant to alcohol drowsiness. Based on Western blot analysis, we also confirmed that the phosphorylation of these proteins is directly induced by propofol, indicating that propofol anesthesia may be relevant to cytoskeletal proteins and alcohol drowsiness. CONCLUSIONS: These identified propofol-induced phosphorylations of proteins provide meaningful contributions for further studying the anesthetic mechanism of propofol.

Efficacy and safety of pericapsular nerve group block in total hip arthroplasty: a meta-analysis and systematic review.

INTRODUCTION: Ensuring effective perioperative pain control is a crucial aspect of rehabilitation programs following total hip arthroplasty. This study presents a comprehensive meta-analysis and systematic review to assess the efficacy and safety of pericapsular nerve group block (PENG) in the context of total hip arthroplasty. EVIDENCE ACQUISITION: A systematic search was conducted in multiple databases, including PubMed, Embase, Cochrane Library, and Web of Science, to identify relevant randomized controlled studies investigating the efficacy and safety of PENG for total hip arthroplasty. The search was conducted up until 1st June 2023. Data analysis was performed using Stata v. 15.0. EVIDENCE SYNTHESIS: A total of 721 individuals participated in this study, which included 13 randomized controlled trials. Among them, 377 individuals were assigned to the experimental group, while 344 individuals were assigned to the control group. The findings from the meta-analysis indicated that the application of PENG yielded favorable outcomes in terms of reducing six-hour pain scores (SMD=-0.63, 95% CI -1.18, -0.09) and 24-hour pain scores (SMD=-1.45, 95% CI -2.51, -0.29). Moreover, it was found to decrease opioid consumption (SMD=-0.84, 95% CI -1.35, -0.34), without causing a significant increase in nausea and vomiting (RR=0.75, 95% CI 0.45, 1.23) or urinary retention (RR=2.46, 95% CI 0.49, 12.31). CONCLUSIONS: Based on the latest findings, PENG has been shown to effectively decrease pain scores within six and 24 hours following total hip arthroplasty. However, its effectiveness in pain control diminishes after 48 hours. Additionally, PENG has demonstrated the ability to reduce opioid consumption without an accompanying increase in adverse drug events.

Melatonin regulates microglial M1/M2 polarization via AMPKα2-mediated mitophagy in attenuating sepsis-associated encephalopathy.

BACKGROUND: Sepsis-associated encephalopathy (SAE) is a disease characterized by neuroinflammation and cognitive dysfunction caused by systemic infection. Inflammation-induced microglial activation is closely associated with neuroinflammation in SAE. It is widely understood that melatonin has strong anti-inflammatory and immunomodulatory properties beneficial for sepsis-related brain damage. However, the mechanism of melatonin action in SAE has not been fully elucidated. METHODS: The SAE cell model and SAE mouse model were induced by lipopolysaccharide (LPS). Behavioral tests were performed to analyze cognitive function. Microglial markers and M1/M2 markers were measured by immunofluorescence. Mitophagy was assessed by western blot, mt-Keima and transmission electron microscopy experiments. Immunoprecipitation and co-immunoprecipitation assays investigated the interactions between AMP-activated protein kinase α2 (AMPKα2) and PTEN-induced putative kinase 1 (PINK1). RESULTS: Melatonin suppresses LPS-induced microglia M1 polarization by enhancing mitophagy, thereby attenuating LPS-induced neuroinflammation and behavioral deficits. However, inhibition or knockdown of AMPKα2 can inhibit the enhancement of melatonin on mitophagy, then weaken its promotion of microglia polarization towards M2 phenotype, and eliminate its protective effect on brain function. Furthermore, melatonin enhances mitophagy through activating AMPKα2, promotes PINK1 Ser495 site phosphorylation, and ultimately regulates microglial polarization from M1 to M2. CONCLUSIONS: Our findings demonstrate that melatonin facilitates microglia polarization towards M2 phenotype to alleviate LPS-induced neuroinflammation, primarily through AMPKα2-mediated enhancement of mitophagy.

Understanding the variability of ground-level ozone and fine particulate matter over the Tibetan plateau with data-driven approach.

The Tibetan Plateau, known as the "Third Pole", is susceptible to ground-level ozone (O3) and fine particulate matter (PM2.5) pollution due to its unique high-altitude environment. This study constructed random forest regression models using multi-source data from ground measurements and meteorological satellites to predict variations in ground-level O3 and PM2.5 concentrations and their influencing factors across seven major cities in the Tibetan Plateau over two-year periods. The models successfully reproduced O3 and PM2.5 levels with satisfactory R-squared values of 0.71 and 0.73, respectively. Results reveal combustion-related carbon monoxide (CO) and nitrogen dioxide (NO2) as the most substantial influences on O3 and PM2.5 concentrations. Solar radiation, geographical factors, and meteorological variables also played crucial roles in driving pollutant variations. Conversely, transport-related and human activity factors exhibited relatively lower significance. High O3 and PM2.5 pollution occurred during pre-monsoon and post-monsoon/winter seasons, driven by solar radiation and emissions, respectively. While CO consistently contributed across cities and seasons, key influencing factors varied locally. This study unveils the key driving forces governing air pollutant variations across the Tibetan Plateau, shedding light on complex atmospheric processes in this unique high-altitude region.

Direct emissions of particulate glyoxal and methylglyoxal from biomass burning and coal combustion.

Glyoxal (Gly) and methylglyoxal (Mgly) are key precursors globally for secondary organic aerosol (SOA) formation. These two species were often thought to be formed in the atmosphere via photochemical oxidation of organics from biogenic and anthropogenic origins, although few studies have shown their direct emissions. In this study, we report direct emissions of particulate Gly and Mgly from different residential fuels typically used in north China. The emission ratios (ERs) and emission factors (EFs) of particulate Gly and Mgly for biomass burning were approximate 5-fold and 7-fold higher than those for coal combustion, respectively. The large variances in emissions of Gly and Mgly could be attributed to the different combustion processes, which influenced by the fuel types and combustion conditions. The averaged ERs and EFs of particulate Gly and Mgly were about one order of magnitude lower than their gaseous counterparts due to the low Henry's law constant, which was also consistent with the low particle-to-gas ratio of Gly (0.04) and Mgly (0.02). Our results suggest that the direct emissions of Gly and Mgly from emission sources should be considered when estimating the formation of SOA from Gly and Mgly.

System pharmacology-based determination of the functional components and mechanisms in chronic heart failure treatment: an example of Zhenwu decoction.

Chronic heart failure (CHF) is the primary cause of death among patients with cardiovascular diseases, representing the advanced stage in the development of several cardiovascular conditions. Zhenwu decoction (ZWD) has gained widespread recognition as an efficacious remedy for CHF due to its potent therapeutic properties and absence of adverse effects. Nevertheless, the precise molecular mechanisms underlying its actions remain elusive. This study endeavors to unravel the intricate pharmacological underpinnings of five herbs within ZWD concerning CHF through an integrated approach. Initially, pertinent data regarding ZWD and CHF were compiled from established databases, forming the foundation for constructing an intricate network of active component-target interactions. Subsequently, a pioneering method for evaluating node significance was formulated, culminating in the creation of core functional association space (CFAS). To discern vital components, a novel dynamic programming algorithm was devised and used to determine the core component group (CCG) within the CFAS. Enrichment analysis of the CCG targets unveiled the potential coordinated molecular mechanisms of ZWD, illuminating its capacity to ameliorate CHF by modulating genes and related signaling pathways involved in pathological remodeling. Notable pathways encompass PI3K-Akt, diabetic cardiomyopathy, cAMP and MAPK signaling. Concluding the computational analyses, in vitro experiments were executed to assess the effects of vanillic acid, paradol, 10-gingerol and methyl cinnamate. Remarkably, these compounds demonstrated efficacy in reducing the production of ANP and BNP within isoprenaline-induced AC 16 cells, further validating their potential therapeutic utility. This investigation underscores the efficacy of the proposed model in enhancing the precision and reliability of CCG selection within ZWD, thereby presenting a novel avenue for mechanistic inquiries, compound refinement and the secondary development of TCM herbs.

Seasonality of Aerosol Sources Calls for Distinct Air Quality Mitigation Strategies.

An Aerosol Chemical Speciation Monitor (ACSM) was deployed to investigate the temporal variability of non-refractory particulate matter (NR-PM1) in the coastal city of Galway, Ireland, from February to July 2016. Source apportionment of the organic aerosol (OA) was performed using the newly developed rolling PMF strategy and was compared with the conventional seasonal PMF. Primary OA (POA) factors apportioned by rolling and seasonal PMF were similar. POA factors of hydrocarbon-like OA (HOA), peat, wood, and coal were associated with domestic heating, and with an increased contribution to the OA mass in winter. Even in summer, sporadic heating events occurred with similar diurnal patterns to that in winter. Two oxygenated OA (OOA) factors were resolved, including more-oxygenated OOA and less-oxygenated OOA (i.e., MO-OOA and LO-OOA, accordingly) which were found to be the dominant OA factors during summer. On average, MO-OOA accounted for 62% of OA and was associated with long-range transport in summer. In summer, compared to rolling PMF, the conventional seasonal PMF over-estimated LO-OOA by nearly 100% while it underestimated MO-OOA by 30%. The results from this study show residential heating and long-range transport alternately dominate the submicron aerosol concentrations in this coastal city, requiring different mitigation strategies in different seasons.

Polycyclic aromatic hydrocarbons from cooking emissions.

Air pollution studies have often overlooked the contribution from cooking to the particle-bound polycyclic aromatic hydrocarbons (PAHs) in the ambient environment, despite cooking emissions have been identified as an important source of organic aerosol in most urban areas, known as the cooking-like organic aerosol factor (i.e., COA). In this study, a Long-Time-of-Flight (LToF) soot particle aerosol mass spectrometer (SP-AMS) was deployed to evaluate the impact of cooking emissions on outdoor particle-bound PAHs levels during a summer campaign in 2019 in Xi'an China. Combined with the robust receptor model, cooking emission was found to be the major source of ambient PAHs, on average, accounting for 90% of PAHs, 9 times higher than traffic (10%). The ambient cooking PAH profile was well correlated (r2 of 0.87) with that for frying oil fume, suggesting cooking oil was the major source of PAHs instead of the food being cooked. We further evaluated the health risk associated with the cooking PAHs and estimated the cooking PAH levels in some of the major cities in the world where COA factor has been reported. The results show the particle-bound PAHs from cooking can be an important source of ambient PAHs in most Chinese cities. The findings from this study hold important implications for public health and are informing for policymakers.

Large contribution from worship activities to the atmospheric soot particles in northwest China.

Worship activities like burning joss paper during the Chinese Hanyi festival is a common, traditional custom in northwest China. However, the pollutants of e.g., soot particles, released from joss paper burning and the corresponding impacts on urban air quality were poorly investigated, which can be a particular concern since these activities are conducted in an uncontrolled manner. In this study, a long time-of-flight (LToF) soot particle aerosol mass spectrometry (SP-AMS) was deployed to characterize the refractory black carbon (rBC) emitted from the joss paper burning, as well as crop residue, coal combustion, and traffic during the Hanyi Festival in mid-November 2020 in the northwestern city of Xi'an in China. Large difference (from <5% to >100%) in the fragmentation patterns (Cn+) for the measured rBC from different source emissions were found when compared to the reference Regal Black. Using the receptor model of positive matrix factorization (PMF) with the multilinear engine (ME-2) algorithm, the obtained rBC mass spectra were used as the anchoring profiles to evaluate the emission strengths of different source types to the atmospheric rBC. Our results show that the burning of joss paper accounted for up to 42% of the atmospheric rBC mass, higher than traffic (14-17%), crop residue (10-17%), coal (18-20%) during the Hanyi festival in northwest China. Moreover, we show that the overall air quality can be worsened due to the practice of uncontrolled burning of joss paper during the festival, which is not just confined to the people who do the burning. Although worship activities occur mainly during festival periods, the pollution events contributed by joss paper burning may pose an acute exposure risk for public health. This is particularly important since burning joss paper during worship activities is common in China and most Asian countries with similar traditions.