Recent-year variations in O3 pollution with high-temperature suppression over central China.

By analyzing environmental and meteorological monitoring data over recent years of 2015-2022, the Twain-Hu Basin (THB) in central China was identified as a regional O3 pollution center over China with the highest increasing trend at 1.10 %⸱yr-1 in interannual variations of O3 concentrations with deteriorating O3 pollution over recent years. We explored the spatiotemporal variations in O3 pollution in the THB with ozone suppression (OS) under high air temperature over metropolitan, small urban, and mountainous areas. The bipolarized interannual trends in interannual O3 variations in urban and mountainous areas over central China were characterized with the increasing and decreasing 90th percentiles of the daily maximum 8-h (MDA8-90) O3 concentrations respectively in polluted urban areas and clean mountainous areas over recent eight years. The changes of the near-surface O3 concentrations with air temperature exhibited the inflection points of OS from increasing to decreasing O3 at air temperature of 30.5 °C in mountainous areas, 32.5 °C in small urban areas, and 34.5 °C in metropolitan areas, and the intensity of OS was estimated in the ranking with mountainous areas (-2.30 µg⸱m-3⸱°C-1) > small urban areas (-1.96 µg⸱m-3⸱°C-1) > metropolitan areas (-1.54 µg⸱m-3⸱°C-1), indicating that the OS was more significant over the lower-O3 mountainous areas. This study has implications for understanding O3 pollution variations with the meteorological drivers.

Interannual variations in ozone pollution with a dipole structure over Eastern China associated with springtime thermal forcing over the Tibetan Plateau.

The Tibetan Plateau (TP) is essential in modulating climate change in downstream Eastern China (EC). As a meteorology-sensitive pollutant, changes in ozone (O3) in connection with the TP have received limited attention. In this study, using climate analysis of the China High Air Pollutants O3 product and ERA5 reanalysis data of meteorology for 1980-2020, the effect of springtime TP thermal forcing on the warm season (April-September) O3 pollution over EC was investigated. The strong TP thermal effect significantly modulates the interannual variations in O3 pollution with a dipole pattern over EC, inducing more O3 pollution in northern EC regions and alleviating O3 pollution in the southern regions. In northern (southern) EC, strong TP thermal forcing triggers a significant anomalous high (low) pressure center accompanied by anticyclonic (cyclonic) anomalies, resulting in decreased (increased) total cloud cover, increased (reduced) surface downward solar radiation and air temperature, which are conducive to the anomalous increase (decrease) in surface O3 concentrations. Moreover, the key sources of springtime thermal forcing over the TP influence the major O3 pollution regions over southern and northern EC with an inverse pattern, depending on their locations and orientations to the large topography of the TP. This research reveals an important driving factor for the dipole interannual variation in O3 pollution over EC, providing a new prospect for the effect of the TP on atmospheric environmental change.

Inverse effects of aerosol radiative forcing on heavy PM2.5 pollution of local accumulation and regional transport over Central China.

Regional transport of air pollutants is a crucial factor influencing atmospheric environment, and aerosol radiative forcing (ARF) feedback to atmospheric boundary layer (ABL) structure and ambient air pollution is yet to be comprehensively understood over the receptor region of regional transport. By simulating meteorology and air pollutants during a heavy PM2.5 pollution event with WRF-Chem model, we quantitatively investigated the ARF and ABL interaction for PM2.5 pollution over the Twain-Hu Basin (THB), a key receptor region of regional transport over central China. Driven by northerly winds, PM2.5 was transported from upstream north China to downstream THB accompanied by high PM2.5 levels in the free troposphere. The ARF exacerbated local PM2.5 accumulation by up to 20 µg m-3 and inhibited the impact of regional transport on PM2.5 levels in the ABL with reducing near-surface PM2.5 concentrations of 5 µg m-3 over the THB. The ARF-intensified air temperature inversion at the top of ABL was unfavorable for the transported air pollutants crossing the ABL top to the near-surface layer, thus weakening the impact of regional PM2.5 transport on air quality in the receptor region. Meanwhile, the ARF of transported PM2.5 induced updrafts in the free troposphere, promoting vertical mixing of air pollutants with positive feedback on increasing secondary PM2.5 concentrations in the free troposphere. The ARF induced more and less secondary PM2.5 formations respectively in the free troposphere and the near-surface layer during the regional transport period of air pollution. These results enhance our comprehension of aerosol-meteorology feedback in regional changes of atmospheric environment with inverse effects of ARF on PM2.5 pollution of local accumulation and regional transport.

Terrain effect on atmospheric process in seasonal ozone variation over the Sichuan Basin, Southwest China.

Terrain effect is challenging for understanding atmospheric environment changes under complex topography. This study targets the Sichuan Basin (SCB), a deep basin isolated by plateaus and mountains in Southwest China, by employing WRF-Chem with integrated process rates (IPR) analysis to characterize the terrain-driven seasonal variations of tropospheric ozone (O3) with atmospheric physical and chemical processes. Results show that the basin terrain exerts reversed impacts on regional air quality changes by aggravating summertime and alleviating wintertime near-surface O3 with the relative contributions oscillating seasonally between -40% and 40% in SCB. Similarly, a seasonal shift of vertical O3 structures is dominated by summertime positive and wintertime negative changes in the lower troposphere induced by basin terrain. The key contributions of atmospheric process to near-surface O3 are identified with vertical and horizontal transport, which is dominated by basin terrain with intensifying seasonal and diurnal variations. With the existence of basin, the daytime O3 productions at the near-surface layer are elevated in months of warm seasons (April and July) but inhibited in the cold seasons (October and January), presenting a seasonal transition of primary factor from meteorology to aerosol-radiation forcing on photochemical reactions. Driven by plateau-basin thermodynamic forcing, horizontal O3 transport between the SCB and eastern TP is enhanced by mountain-plains solenoid (MPS), and even nocturnal O3-rich layers contribute to the impacts of vertical exchange on near-surface O3 levels. The terrain effects of deep basin under the interaction of Asian monsoons and westerlies could jointly change atmospheric physical and chemical processes to construct the seasonal and diurnal O3 evolution patterns over the SCB region.

The S1PR1 agonist SEW2871 promotes the survival of skin flap.

Skin flap transfer is an important method to repair and reconstruct various tissue defects; however, avascular necrosis largely affects the success of flap transfer. The sphingosine 1-phosphate receptor 1 (S1PR1) agonist SEW2871 has been proven to ameliorate ischemic injury; however, its effect on flap survival has not been reported. In this study, an experimental skin flap model was established in rats to investigate the roles of SEW2871. The results indicated that SEW2871 greatly increased the survival of the skin flap, alleviated pathological injury, promoted the angiogenesis, and inhibited cells apoptosis in skin flap tissues. SEW2871 activated S1PR1 downstream signaling pathways, including heat shock protein 27 (HSP27), extracellular regulated protein kinases (ERK), and protein kinase B (Akt). In addition, SEW2871 promoted the expression of S1PR1. These findings may provide novel insights for skin flap transfer.

Importance of regional PM2.5 transport and precipitation washout in heavy air pollution in the Twain-Hu Basin over Central China: Observational analysis and WRF-Chem simulation.

With observational analysis and WRF-Chem simulation on a heavy air pollution event in January 2019 over the Twain-Hu Basin (THB) in Central China, this study characterized the regional transport of PM2.5 emitted from the North China Plain (NCP) to the THB region in Central China and quantitatively assessed the influence of the regional PM2.5 transport and precipitation washout on PM2.5 change in the wintertime heavy air pollution over the THB. It was found that the THB's heavy air pollution event was exacerbated by the strong northeasterly winds driving a quasi 2-day time lag of regional PM2.5 transport from the NCP to the THB. The multi-scale atmospheric circulations of cold air invasion influenced by East Asian winter monsoon and the terrain block of THB altered the structures of regional PM2.5 transport in deteriorating air quality to the THB. It was assessed for the THB region that the enhancing contribution of regional PM2.5 transport to the high air pollution level reached up to 70.5% in the heavy air pollution, and the precipitation washout could contribute the 55.3% PM2.5 removal to dissipating the PM2.5 pollution over the THB with frequent precipitation and wet environment, distinguishing from the dominance of wind-cleaning air pollution in the other regions in China.

[Analysis of Pollution Characteristics and Sources of PM2.5 Chemical Components in Chengdu in Winter].

Day-night PM2.5 samples were continuously collected in Chengdu from January 1 to 20, 2017, and the concentrations of major chemical components (water-soluble ions and carbonaceous components) were measured in the laboratory. During the observation period, the average mass concentration of PM2.5 was (127.1±59.9) µg·m-3. The mass concentration of water-soluble ions was (56.5±25.7) µg·m-3 and SO42-, NO3-, and NH4+ were the most dominant ions with a concentration of (13.6±5.5), (21.4±12.0), and (13.3±5.7) µg·m-3, respectively, accounting for 85.6% of the water-soluble ions. The average mass concentrations of organic carbon (OC) and elemental carbon (EC) were 34.0 and 6.1 µg·m-3, respectively, accounting for 26.8% and 4.8% of the PM2.5 mass concentration, respectively. The comparison of the average day-night concentration shows that the daytime and nighttime mass concentrations of PM2.5 are (120.4±56.4) and (133.8±64.0) µg·m-3, respectively, and that the nighttime pollution is more serious. The SO42-, NO3-, and NH4+ concentrations are higher during the day than at night, which is related to daytime light, which promotes the formation of secondary ions. The Cl-, K+, OC, and EC concentrations increase significantly, which may be affected by increased emissions from coal and material combustion. Based on the literature review and comparison of the winter chemical composition of PM2.5 in Chengdu in recent years, the SO42- concentration significantly decreases from 50.6 µg·m-3 in 2010 to 13.6 µg·m-3 in 2017. The NO3- concentration changes little; it is maintained at~20 µg·m-3. The analysis of the acid-alkali ion balance shows that PM2.5 in Chengdu is alkaline due to the relative overgrowth of NH4+, which is different from previous partially acidic results. The average value of NO3-/SO42- is 1.57. Mobile sources have a greater impact on the PM2.5 pollution in Chengdu in winter. The correlation coefficients of OC and EC between daytime and nighttime are 0.82 and 0.90, respectively (P<0.01), which indicates that the OC and EC sources are consistent. The SOC estimation shows that the SOC concentrations during the day and night are 8.5 µg·m-3 and 11.9 µg·m-3, respectively, accounting for 28.1% and 30.8% of the OC, respectively. The K+/EC average value is 0.31 and the correlation coefficient between K+ and OC is 0.87 (P<0.01), indicating that biomass combustion has a certain influence on the carbonaceous aerosol in Chengdu in winter. The principal component analysis shows that the winter PM2.5 in Chengdu mainly originates from combustion sources (coal burning, biomass burning, etc.), secondary inorganic sources, and soil and dust sources. The contribution rates are 32.8%, 34.5%, and 21.5%, respectively.

Rapamycin Protects Skin Fibroblasts from Ultraviolet B-Induced Photoaging by Suppressing the Production of Reactive Oxygen Species.

BACKGROUND/AIMS: Ultraviolet B (UVB) irradiation alters multiple molecular pathways in the skin, thereby inducing skin photoaging. Murine dermal fibroblasts (MDFs) were subjected to a series of 4 sub-cytotoxic UVB doses (120 mJ/cm2), resulting in changes in cell shape, DNA damage, cell cycle arrest, extracellular matrix variations, reactive oxygen species (ROS) generation, and alterations in major intracellular antioxidant and cellular autophagy levels. Rapamycin (RAPA) is a new macrolide immunosuppressive agent that is primarily used in oncology, cardiology, and transplantation medicine and has been found to extend the lifespan of genetically heterogeneous mice. Several studies have shown that RAPA may have anti-aging effects in cells and organisms. Thus, in this study, we explored the effects and mechanisms of RAPA against the photoaging process using a well-established cellular photoaging model. METHODS: We developed a stress-induced premature senescence (SIPS) model through repeated exposure of MDFs to ultraviolet B (UVB) irradiation. The cells were cultured in the absence or presence of RAPA for 48 h. Senescent phenotypes were assessed by examining cell viability, cell morphology, senescence-associated ß-galactosidase (SA-ß-gal) expression, cell cycle progression, intracellular ROS production, matrix metalloproteinase (MMP) synthesis and degradation, extracellular matrix (ECM) component protein expression, alterations in major intracellular antioxidant levels, and the cellular autophagy level. RESULTS: Compared with the UVB group, pretreatment with RAPA (5 µM) significantly decreased the staining intensity and percentage of SA-ß-gal-positive cells and preserved the elongated cell shape. Moreover, cells pretreated with RAPA showed inhibition of the reduction in the type I collagen content by blocking the UVB-induced upregulation of MMP expression. RAPA also decreased photoaging cell cycle arrest and downregulated p53 and p21 expression. RAPA application significantly attenuated irradiation-induced ROS release by modulating intracellular antioxidants and increasing the autophagy level. CONCLUSIONS: Our study demonstrated that RAPA elicited oxidative damage in vitro by reducing ROS accumulation in photoaged fibroblasts. The anti-aging effect can be attributed to the maintenance of normal antioxidant and cellular autophagy levels. However, determination of the definitive mechanism requires further study.

Mycobacterium abscessus Infection After Facial Injection With Autologous Fat: A Case Report.

We report a case of Mycobacterium abscessus infection in a 29-year-old woman after facial injection with autologous fat. Nineteen months previously, she received a facial surgery of autologous fat injection with the fat harvested from her inner thigh. On examination, she had multiple painful and fluctuant abscesses associated with local pyrexia in her bilateral temporal and lower orbital regions. A B ultrasound revealed multiple fat liquefaction in her bilateral temporal and lower orbital regions. The acid-fast bacilli culture and polymerase chain reaction sequencing confirmed M. abscessus infection. She was treated with moxifloxacin, clarithromycin, and ethambutol for 12 months, and finally the symptoms subsided. To avoid infection after fat graft, aseptic technique as well as standard operation of the fat harvest and process should be strictly enforced. In cases of persistent infection, or invalid cases treated with conventional antibiotic therapy, nontuberculous mycobacteria should be suspected, and a polymerase chain reaction sequencing as well as a drug sensitivity test should be carried out.

Efficacy and Safety of Botulinum Toxin Type A in the Treatment of Glabellar Lines: A Meta-Analysis of Randomized, Placebo-Controlled, Double-Blind Trials.

BACKGROUND: The uses of botulinum toxin type A for facial aesthetic procedures have been reported in recently published studies. The authors systematically analyzed the prospective, randomized, controlled trials, which continue to expand. New efficacy data and endpoints regarding the safety of botulinum toxin type A injection for treating glabellar lines were analyzed. METHODS: The authors identified randomized controlled trials of botulinum toxin type A through searches of Ovid MEDLINE, PubMed, Elsevier, and the Cochrane Library from January of 2002 to November of 2014. The search terms included "botulinum toxin" and "glabellar lines." Only randomized, placebo-controlled, double-blind trials that used an injection dose of 20 units were included in the analysis. Safety was assessed by means of a meta-analysis of the number and frequency of adverse events. RESULTS: Seven studies involving 1474 subjects met inclusion criteria and qualified for meta-analysis. Overall, the pooled effective rate assessed by investigators in botulinum toxin type A treatment groups was significantly higher than that in controls (relative risk, 33.54; 95 percent CI, 18.65 to 60.33). The effective rate in treatment groups using a new endpoint was also higher than that in controls (relative risk, 99.04; 95 percent CI, 14.0 to 700.58). Subgroup analysis confirmed that botulinum toxin type A could improve the appearance of glabellar lines at rest (relative risk, 5.88; 95 percent CI, 3.49 to 9.91). There were no significant differences in the frequency of adverse events between the treatment and placebo groups in any of the studies. CONCLUSION: This meta-analysis shows that a single 20-unit dose of botulinum toxin type A is considered remarkably effective and safe for the treatment of glabellar lines. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, II.

A modified technique for expanded polytetrafluoroethylene shaping in chin augmentation: parallel groove carving technique.

OBJECTIVE: In the current study, we restricted our focus on a modified approach to address the poor curved attachment of expanded polytetrafluoroethylenein chin augmentation. METHOD: The implant is shaped generally in accordance with the chin, followed by 5-to-8 longitudinally parallel "V"-grooves carved in the median of posterior site where the implant directly attaches to the mandible. Thus, it enhances bend ductility of the prosthesis and renders better attachment from the curved surface of prosthesis to the mandibular embedded region. RESULTS: This procedure was performed in 15 patients. After follow-up for 2 to 6 months, there were no complications observed postoperatively including mobilization, dead space, subcutaneous dropsy, topical infection, or palpable edges in the subcutaneous area. CONCLUSIONS: The introduction of longitudinally parallel V-groove technique provides an effective method for avoidance of increasing hardness, decreasing flexibility, and palpable edges after implantation.As a novel and effective technique, it is beneficial for better attachment and satisfactory outcome without causing extra expenses.

Rosiglitazone ameliorates senescence-like phenotypes in a cellular photoaging model.

BACKGROUND: Rosiglitazone (RO), a second-generation thiazolidinedione used mainly in the treatment of non-insulin-dependent diabetes mellitus, has been discovered to be a high-affinity ligand for peroxisome proliferator-activated receptor-γ (PPAR-γ). Several studies have revealed that PPAR-γ is also involved in the regulation of oxidative stress and chronic inflammation associated with aging process in vivo as well as with cellular senescence in vitro. We sought to investigate whether RO pretreatment will counteract the photoaging process using a well-established cellular photoaging model. METHODS: Murine dermal fibroblasts (MDFs) were cultured in the absence or presence of RO for 48h, followed by exposure to repeated UVB irradiation. The senescent phenotypes were evaluated including cell viability, senescence-associated ß-galactosidase (SA-ß-gal) expression, cell morphology, ROS generation, cell cycle, production and degradation of extracellular matrix (ECM), and the potential mechanisms were discussed. RESULTS: Pretreatment with RO (40µM) significantly decreased the staining intensity and the percentage of SA-ß-gal-positive cells and reserved the elongated cell shape compared with UVB group. The cells pretreated with RO also showed decreased UVB-induced degradation of type I collagen by decreasing MMPs expressions. In addition, we observed counteraction of cell-cycle arrest and repression of UVB-induced p53 and p21 in the presence of RO. We further confirmed a significant decrease in ROS accumulation accompanied by an increase in catalase in RO group. CONCLUSIONS: RO, a potent PPAR-γ activator, counteracts senescence-like phenotypes, including long-term growth arrest, flattened morphology, degradation of ECM and SA-ß-gal-positive staining in MDFs by inhibiting the expression of MMPs and increasing the synthesis of catalase when administered to repeated UVB irradiation. The novel application of RO may lead to innovative and effective anti-photoaging therapies.