Efficient Tin-Lead Perovskite Solar Cells with a Ultrawide Usage Windows of Precursor Solution Opened by SnF2.

High quality tin-lead perovskite solar cells (Sn─Pb PSCs) can be fabricated via simple solution processing methods. However, the instability of precursor solutions and their narrow usage windows still pose challenges in manufacturing efficient and reproducible Sn─Pb PSCs, hindering the commercialization of PSCs. Fluorine tin (SnF2) is widely used as an antioxidant to improve the crystallinity of perovskite. In this study, another role of SnF2 as a stabilizer is found to restrain the deprotonation of methylammonium iodide (MAI) in the precursor solution, which improves their stability and expands their usage windows. Due to the inhibition of SnF2 on oxidation and deprotonation, stable large-sized colloidal clusters form gradually in perovskite precursor solution during aging, leading to uniform nucleation/crystallization during film growth, significantly reducing the roughness and defect density in the films. Because of the competitive deprotonation and oxidation process of Sn2+, the benefit of larger cluster maximizes after about ten days storage of precursor solution. The champion efficiency of Sn─Pb PSCs prepared with 10 days aged precursor solution is 22.00%. High performance of devices fabricated with precursor solution stored for even ≈40 days discloses the wide usage windows of precursor solution with SnF2 additive.

Metabolomic analysis reveals the changing trend and differential markers of volatile and nonvolatile components of Artemisiae argyi with different aging years.

INTRODUCTION: Artemisia argyi Folium (AAF) is a traditional medicinal herb and edible plant. Analyzing the differential metabolites that affect the efficacy of AAF with different aging years is necessary. OBJECTIVE: The aim of the study was to investigate the changing trend and differential markers of volatile and nonvolatile metabolites of AAF from different aging years, which are necessary for application in clinical medicine. METHODOLOGY: Metabolites were analyzed using a widely targeted metabolomic approach based on ultrahigh-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) and gas chromatography tandem mass spectrometry (GC-MS). RESULTS: A total of 153 volatile metabolites and 159 nonvolatile metabolites were identified. Principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA) could clearly distinguish AAF aged for 1 year (AF-1), 3 years (AF-3), and 5 years (AF-5). Seven flavonoids and nine terpenoids were identified as biomarkers for tracking the aging years. CONCLUSIONS: The metabolomic method provided an effective strategy for tracking and identifying biomarkers of AAF from different aging years. This study laid the foundation for analysis of the biological activity of Artemisia argyi with different aging years.

Utilizing Extracellular Vesicles for Eliminating 'Unwanted Molecules': Harnessing Nature's Structures in Modern Therapeutic Strategies.

Extracellular vesicles (EVs) are small phospholipid bilayer-bond structures released by diverse cell types into the extracellular environment, maintaining homeostasis of the cell by balancing cellular stress. This article provides a comprehensive overview of extracellular vesicles, their heterogeneity, and diversified roles in cellular processes, emphasizing their importance in the elimination of unwanted molecules. They play a role in regulating oxidative stress, particularly by discarding oxidized toxic molecules. Furthermore, endoplasmic reticulum stress induces the release of EVs, contributing to distinct results, including autophagy or ER stress transmission to following cells. ER stress-induced autophagy is a part of unfolded protein response (UPR) and protects cells from ER stress-related apoptosis. Mitochondrial-derived vesicles (MDVs) also play a role in maintaining homeostasis, as they carry damaged mitochondrial components, thereby preventing inflammation. Moreover, EVs partake in regulating aging-related processes, and therefore they can potentially play a crucial role in anti-aging therapies, including the treatment of age-related diseases such as Alzheimer's disease or cardiovascular conditions. Overall, the purpose of this article is to provide a better understanding of EVs as significant mediators in both physiological and pathological processes, and to shed light on their potential for therapeutic interventions targeting EV-mediated pathways in various pathological conditions, with an emphasis on age-related diseases.

Sex Differences in Longitudinal Trajectories of Cognitive Aging in Zaragoza, Spain.

OBJECTIVES: The objective of this study was to document the longitudinal trajectories of cognitive aging in a sample of cognitively healthy subjects of 55 years or older. The following differences between men and women were hypothesized: 1) in the cognitive loss through aging, 2) in the distinct trajectories identified; and 3) in the predictors associated with the identified trajectories. DESIGN AND SETTING: A 4-wave, population-based study in Zaragoza, Spain (1994-2006). PARTICIPANTS: A total of 2,403 individuals aged 55+ years, cognitively healthy at baseline. MEASUREMENTS: All participants had at least three measurements with the Mini-Mental State Examination (MMSE). Validated Spanish versions of international instruments were used for assessment. Random effects linear panel regression model for analyzing differences by sex in MMSE scores through aging were performed, and growth mixture models (GMM) applied independently for each sex for modeling the longitudinal cognitive trajectories. RESULTS: Women showed lower mean MMSE scores in all phases and significantly higher loss in the MMSE from phases 2 to 3 and 3 to 4. The best fitting age-adjusted model of the cognitive trajectories was a 4-class GMM in men and a 3-class in women. Education was a predictor of cognitive trajectories in both men and women. Dependence on iADLs and alcohol status were predictors only for men, and depression and diabetes only for women. CONCLUSIONS: The identified differences by sex in cognitive trajectories and their associated factors suggest that men and women may require a different strategy when addressing cognitive aging.

How soon do metabolic alterations and oxidative distress precede the reduction of muscle mass and strength in Wistar rats in aging process?

Here we investigate metabolic changes, the antioxidant system and the accumulation of oxidative damage in muscles with different fiber types during the aging process in Wistar rats and try to map how sooner the changes occur. To do so, 30 male Wistar rats were submitted to behavioral evaluation to determine voluntary strength in the 11, 15, and 19 month old rats, measuring the energy metabolism, antioxidant system, oxidative damage and structure in the soleus and extensor digitorum longus muscles. We detected structural and metabolic changes in both muscles, especially in the EDL of 15 month old rats and in the soleus of 19 month old rats. In the 15 month old rats, there was a reduction in the cross-sectional area of the fibers, and a reduction in the proportion of type I fibers, accompanied by an increase in fiber density and the amount of type IIA fibers. This change in the fiber profile was followed by an increase in the activity of anaerobic metabolism enzymes, suggesting a reduction in the oxidative capacity of the muscle. In addition, there was an increase in the rate of lipid peroxidation, accompanied by a reduced antioxidant capacity. In the 19 month old rats, these disturbances got stronger. In summary, the present study demonstrated that before functional disturbances, there was an accumulation of oxidative damage and structural changes in the skeletal muscle beginning at 15 months old in the EDL and the soleus only in the biochemical parameters. Therefore, the metabolic alterations occurred at 15 months old and not before.

Impact of HIV on COVID-19 Outcomes: A Propensity Score Matching Analysis with Varying Age Differences.

To exploratorily test (1) the impact of HIV and aging process among PLWH on COVID-19 outcomes; and (2) whether the effects of HIV on COVID-19 outcomes differed by immunity level. The data used in this study was retrieved from the COVID-19 positive cohort in National COVID Cohort Collaborative (N3C). Multivariable logistic regression models were conducted on populations that were matched using either exact matching or propensity score matching (PSM) with varying age difference between PLWH and non-PLWH to examine the impact of HIV and aging process on all-cause mortality and hospitalization among COVID-19 patients. Subgroup analyses by CD4 counts and viral load (VL) levels were conducted using similar approaches. Among the 2,422,864 adults with a COVID-19 diagnosis, 15,188 were PLWH. PLWH had a significantly higher odds of death compared to non-PLWH until age difference reached 6 years or more, while PLWH were still at an elevated risk of hospitalization across all matched cohorts. The odds of both severe outcomes were persistently higher among PLWH with CD4 < 200 cells/mm3. VL ≥ 200 copies/ml was only associated with higher hospitalization, regardless of the predefined age differences. Age advancement in HIV might significantly contribute to the higher risk of COVID-19 mortality and HIV infection may still impact COVID-19 hospitalization independent of the age advancement in HIV.

Aging of Nanoplastics Significantly Affects Protein Corona Composition Thus Enhancing Macrophage Uptake.

Nanoplastics (NPs), as emerging contaminants, have attracted increasing attention for their effects on human exposure and potential health risks. The protein corona formed on the surface of NPs affects the biological activity and fate of the NPs in vivo. However, how environmental aging, an inevitable process once NPs enter the environment, affects the formation of protein corona on NPs is still unclear. This study investigated the changes in the compositions of protein corona formed on photo-aged polystyrene (PS) NPs in human bronchoalveolar lavage fluid (BALF), corresponding to the inhalation exposure pathway. The results demonstrated that both the species and abundance of proteins in the BALF protein corona on the surface of PS NPs were altered by aging. In addition, the aged PS NPs are more hydrophilic and less electronegative than the pristine PS NPs; hence, there is an increased sorption of more negatively charged hydrophilic proteins. Moreover, aging-induced alterations in BALF protein corona enhanced the uptake of aged PS NPs by lung macrophages J774A.1 through phagocytosis and clathrin-mediated endocytosis. These findings highlight the importance of environmental aging processes in the biosafety assessment of nanoplastics.

Characterizing emission factors and oxidative potential of motorcycle emissions in a real-world tunnel environment.

Transportation emissions significantly affect human health, air quality, and climate in urban areas. This study conducted experiments in an urban tunnel in Taipei, Taiwan, to characterize vehicle emissions under real driving conditions, providing emission factors of PM2.5, eBC, CO, and CO2. By applying multiple linear regression, it derives individual emission factors for heavy-duty vehicles (HDVs), light-duty vehicles (LDVs), and motorcycles (MCs). Additionally, the oxidative potential using dithiothreitol assay (OPDTT) was established to understand PM2.5 toxicity. Results showed HDVs dominated PM2.5 and eBC concentrations, while LDVs and MCs influenced CO and CO2 levels. The CO emission factor for transportation inside the tunnel was found to be higher than those in previous studies, likely owing to the increased fraction of MCs, which generally emit higher CO levels. Among the three vehicle types, HDVs exhibited the highest PM2.5 and eBC emission factors, while CO and CO2 levels were relatively higher for LDVs and MCs. The OPDTTm demonstrated that fresh traffic emissions were less toxic than aged aerosols, but higher OPDTTv indicated the impact on human health cannot be ignored. This study updates emission factors for various vehicle types, aiding in accurate assessment of transportation emissions' effects on air quality and human health, and providing a guideline for formulating mitigation strategies.

Effects of Testosterone Replacement Therapy on Muscle Strength in Older Men with Low to Low-Normal Testosterone Levels: A Systematic Review and Meta-Analysis.

BACKGROUND: Previous studies and meta-analyses have explored the relationship among testosterone, muscle strength, and physical function, to the best of our knowledge, no meta-analysis has investigated the effects of testosterone replacement therapy (TRT) on subgroup of relatively hypogonadal older men. OBJECTIVE: The aim of this study was to evaluate the effect of TRT in older men with low testosterone levels. METHODS: PubMed, Embase, and Web of Science were systematically searched for articles published between January 1990 and April 2020. We included randomized controlled studies that investigated the effect of TRT and included older men (age >60 years) with relatively low testosterone levels. Studies were extracted following the PRISMA flowchart, and the included randomized controlled trials were evaluated using RoB 2.0. Our main outcome was muscle strength changes after TRT evaluated using a metaregression of confounding factors. Secondary outcomes included changes in physical performance and the risk ratio of adverse events. Random-effects meta-analyses of TRT on muscle strength and physical function were performed. RESULTS: Thirteen studies with 2,043 patients were included. The mean age of subjects in various studies ranged from 65.9 years to 76 years. Transdermal testosterone dosages ranged from 5 to 10 g/day, while intramuscular options were 125 mg/week or 200 mg every 2 weeks. Oral testosterone supplementation was given at 160 mg/day in one study. Pooled meta-analyses revealed greater muscle strength improvement after TRT compared with placebo (Hedges' g = 0.21; 95% CI: = 0.15-0.28). Intramuscular administration of TRT had greater efficacy (Hedges' g = 0.74; 95% CI: = 0.34-1.14) than transdermal and oral TRT (p < 0.001). A metaregression revealed that baseline serum total testosterone was associated with muscle strength improvement (ß = -0.004, p = 0.002). The risk ratios of adverse events, including elevated prostate-specific antigen, acute coronary syndrome, and prostate cancer, were not significantly different. CONCLUSION: TRT improved muscle strength in older, relatively hypogonadal men. The effect was more pronounced in populations with lower baseline testosterone levels.

Exploring the aging process of cognitively healthy adults by analyzing cerebrospinal fluid metabolomics using liquid chromatography-tandem mass spectrometry.

BACKGROUND: During biological aging, significant metabolic dysregulation in the central nervous system may lead to cognitive decline and neurodegeneration. However, the metabolomics of the aging process in cerebrospinal fluid (CSF) has not been thoroughly explored. METHODS: In this cohort study of CSF metabolomics using liquid chromatography-mass spectrometry (LC-MS), fasting CSF samples collected from 92 cognitively unimpaired adults aged 20-87 years without obesity or diabetes were analyzed. RESULTS: We identified 37 metabolites in these CSF samples with significant positive correlations with aging, including cysteine, pantothenic acid, 5-hydroxyindoleacetic acid (5-HIAA), aspartic acid, and glutamate; and two metabolites with negative correlations, asparagine and glycerophosphocholine. The combined alterations of asparagine, cysteine, glycerophosphocholine, pantothenic acid, sucrose, and 5-HIAA showed a superior correlation with aging (AUC = 0.982). These age-correlated changes in CSF metabolites might reflect blood-brain barrier breakdown, neuroinflammation, and mitochondrial dysfunction in the aging brain. We also found sex differences in CSF metabolites with higher levels of taurine and 5-HIAA in women using propensity-matched comparison. CONCLUSIONS: Our LC-MS metabolomics of the aging process in a Taiwanese population revealed several significantly altered CSF metabolites during aging and between the sexes. These metabolic alterations in CSF might provide clues for healthy brain aging and deserve further exploration.

Relationship between specific leisure activities and successful aging among older adults.

Background/Objectives: This study was designed to investigate the association between specific leisure activities and successful aging among older adults, using data from the Chinese Longitudinal Healthy Longevity Survey. Methods: A total of 7689 older adults were involved in this study and categorized as successful aging group (n = 3989; 51.8%) or non-successful aging group (n = 3703; 48.2%). Participants were identified as successful aging if they had a score of more than 3 points, or as non-successful aging. The points were based on the following five items and each item was assigned 1 point: self-rated health, self-rated psychological status or mood, cognitive function, activities of daily life, and physical activity. Six activities including gardening work, reading newspapers or books, raising domestic animals or pets, playing cards or mahjong, watching TV or listening to radio, and participating in social activities were collected to reflect leisure activities. Chi-square tests, independent sample t-test, and logistic regression analyses were employed to explore the association between specific leisure activities and successful aging. Results: The prevalence of successful aging was 51.8% among Chinese older adults. A significant positive relationship was found between the frequency of participation in specific leisure activities and successful aging (p < 0.05). Older adults who usually participated in leisure activities had greater odds for successful aging compared to those who never participated in leisure activities (adjusted odds ratio (OR): 1.31 (95% CI: 1.15-1.49) to 1.88 (95% CI: 1.62-2.19)). Older adults participating in one or more leisure activities had greater odds for successful aging compared to those who did not participate in leisure activities (adjusted OR: 1.51 (95% CI: 1.30-1.76) to 4.10 (95% CI: 2.44-6.89)). Conclusions: The findings provide evidence that participating more frequently and in more leisure activities was associated with a greater probability of successful aging among Chinese older adults. Encouraging older people to participate frequently in a larger number of leisure activities may be a key to promote successful aging. Therefore, the frequency and number of participation in leisure activities should be highlighted and targeted for promoting successful aging.

Profiling the role of microorganisms in quality improvement of the aged flue-cured tobacco.

BACKGROUND: The aging process in the tobacco production, as in other food industries, is an important process for improving the quality of raw materials. In the spontaneous aging, the complex components in flue-cured tobacco (FT) improve flavor or reduce harmful compounds through chemical reactions, microbial metabolism, and enzymatic catalysis. Some believed that tobacco-microbe played a significant part in this process. However, little information is available on how microbes mediate chemical composition to improve the quality of FT, which will lay the foundation for the time-consuming spontaneous aging to seek ways to shorten the aging cycle. RESULTS: Comparing aged and unaged FT, volatile and non-volatile differential compounds (DCs) were multi-dimensionally analyzed with the non-targeted metabolomes based on UPLC-QTOP-MS (the ultra-performance liquid chromatography quadrupole time-of-flight mass spectrometry), GC-MS (gas chromatography-mass spectrometer) assisted derivatization and HP-SPME-GC/MS (headspace solid-phase micro-extraction assisted GC-MS). Products associated with the degradation pathways of terpenoids or higher fatty acids were one of the most important factors in improving FT quality. With the microbiome, the diversity and functions of microbial flora were analyzed. The high relative abundance function categories were in coincidence with DCs-related metabolic pathways. According to the correlation analysis, Acinetobacter, Sphingomonas and Aspergillus were presumed to be the important contributor, in which Aspergillus was associated with the highest number of degradation products of terpenoids and higher fatty acids. At last, the screened Aspergillus nidulans strain F4 could promote the degradation of terpenoids and higher fatty acids to enhance tobacco flavor by secreting highly active lipoxygenase and peroxidase, which verified the effect of tobacco-microbes on FT quality. CONCLUSIONS: By integrating the microbiome and metabolome, tobacco-microbe can mediate flavor-related substances to improve the quality of FT after aging, which provided a basis for identifying functional microorganisms for reforming the traditional spontaneous aging.

Dynamic Behaviors of Newly Deposited Atmospheric Heavy Metals in the Soil-Pak Choi System.

Dynamic behaviors of the newly deposited atmospheric heavy metals in the soil-pak choi (Brassica chinensis L.) system are investigated by a fully factorial atmospheric exposure experiment using soils exposed to 0.5-year and 1.5-year atmospheric depositions. The results showed approximately 17-87%, 19-64%, and 43-84% of the Cu, Cd, and Pb in pak choi edible parts were contributed from the new depositions, respectively. For the newly deposited metals, foliar uptake was the key pathway of shoot bioaccumulation rather than from root uptake of the deposited metals in soils, resulting in no significant soil contribution differences between pak chois growing in 0.5-year and 1.5-year exposed soils. Indeed, highly bioavailable metals in atmospheric deposition significantly increased the soil plant-bioavailable Cu, Cd, and Pb fractions; however, soil aging resulted in similar percentages of the plant-bioavailable fractions in 0.5-year and 1.5-year exposed soils, which indicated the bioavailability of metals deposited into soils rapidly decreased with aging. The soil aging process of the deposited metals was well fitted with the first-order exponential decay model, and soil organic matter and clay were the major driving factors. Our findings highlight high plant bioaccumulation rates and the rapid soil aging process of newly deposited metals during the plant growth period.

Adsorption of Cu2+ by UV aged polystyrene in aqueous solution.

Microplastics are the critical carriers of heavy metals in the environment. Thus, investigating the adsorption mechanisms between the microplastics and heavy metals is helpful to understand the migration and transformation pattern of the heavy metals in the environment. The adsorption of microplastics towards heavy metals can be largely affected by natural aging (e.g., UV-aging), environmental pH, and salinity. In this study, the adsorption of polystyrene (PS) towards Cu2+ and the effects of UV-aging, environment pH, and salinity on the adsorption were systematically investigated. The results show that the adsorption capacity of PS towards Cu2+ increased with the UV-aging time, as UV-aging increased the microcracks and oxygen-containing functional groups on the surface of the PS. Adsorption kinetics data followed the pseudo-second-order model, indicating that the interaction between PS and Cu2+ is chemical adsorption. Adsorption isotherms data could be well-described by both the Langmuir and Freundlich models, indicating that the adsorption was multilayer adsorption. As the solution pH and salinity can influence the surface charge of the PS, they could also affect the performance of the PS on Cu2+ adsorption. High pH facilitated the adsorption of PS towards Cu2+, while high salinity (above 1‰) inhibited the adsorption.

A fast and low-cost approach for the discrimination of commercial aged cachaças using synchronous fluorescence spectroscopy and multivariate classification.

BACKGROUND: Cachaça is the distilled beverage typical of Brazil and can be subjected to the aging process in wooden barrels. In addition to oak barrels, cachaça is also aged in barrels of different Brazilian native woods, resulting in a wide variety of its sensory characteristics. In this work, 172 cachaças aged in bálsamo, jequitibá, oak, and umburana barrels were analyzed by synchronous fluorescence spectroscopy and by the classification methods of principal component analysis and partial least squares discriminant analysis. Spectra were preprocessed by the first derivative by Savitzky-Golay smoothing, using a filter width and polynomial order determined through face-centered central composite designs. Multivariate analysis was realized using the spectra recorded at different wavelength differences, and models were compared by the classification errors in the test sets. RESULTS: The principal component analysis applied to the synchronous fluorescence spectra presented a tendency of separation by the wood used in the aging process, and the partial least squares discriminant analysis model constructed using the fluorescence spectra recorded at a wavelength difference of 30 nm provided better performance parameters (efficiency 91-97%, sensitivity 81-100%, and specificity 91-100%). CONCLUSION: Synchronous fluorescence spectroscopy offers a promising approach for the classification of cachaças aged in bálsamo, oak, jequitibá, and umburana barrels, and the discriminant model can be used for routine analysis as a screening method. © 2022 Society of Chemical Industry.

Enhanced mixing state of black carbon with nitrate in single particles during haze periods in Zhengzhou, China.

Black carbon (BC) plays an important role in air quality and climate change, which is closely associated with its mixing state and chemical compositions. In this work the mixing state of BC-containing single particles was investigated to explore the evolution process of ambient BC particles using a single particle aerosol mass spectrometer (SPAMS) in March 2018 in Zhengzhou, China. The BC-containing particles accounted for 61.4% of total detected ambient single particles and were classified into five types including BC-nitrate (BC-N, 52.3%) as the most abundant species, followed by BC-nitrate-sulfate (BC-NS, 22.4%), BCOC (16.8%), BC-fresh (BC-F, 4.5%) and BC-sulfate particles (BC-S, 4.0%). With enhancement of the ambient nitrate concentration, the relative peak area (RPA) of nitrate in BC-N and BCNS particles both increased, yet only the number fraction (Nf) of BCN particles increased while the Nf of BC-NS particles decreased, suggesting that the enhanced mixing state of BC with nitrate was mainly due to the increase in the ambient nitrate mass concentration. In addition, the Nf of BC-N decreased from 65.3% to 28.4% as the absorbing Ångström exponents (AAE) of eBC increased from 0.75 to 1.45, which indicated the reduction of light absorption ability of aged BC particles with the enhanced formation of BC-N particles. The results of this work indicated a change in the mixing state of BC particles due to the dominance of nitrate in PM2.5, which also influenced the optical properties of aged BC particles.

SELECTED PROBLEMS IN THE REHABILITATION OF PATIENTS IN A NURSING AND CARE INSTITUTION.

OBJECTIVE: The aim of the study was to assess selected problems in the rehabilitation of patients staying at a nursing and care institution. PATIENTS AND METHODS: Materials and methods: The study included 33 patients aged 55 to 96 years who were staying at the nursing and care institution in Lipsko. Study patients were examined over a period of 3 months using the standardised Activities of Daily Living (ADL) and Instrumental Activities of Daily Living (I-ADL) scores, the Abbreviated Mental Test Score (AMTS) and the Timed Up and Go Test (TUG). RESULTS: Results: Standardised ADL testing showed that a considerable proportion of study patients (60%) aged 66-75 years had moderate disability. Standardised Lawton scale testing showed that the most difficult complex activities were home maintenance (96.97%), shopping (90.91%), cooking (87.88%), cleaning (87.88%) and doing laundry (78.79%). The standardised Timed Up and Go Test showed that a large proportion of study patients (71.43%) aged 66-75 years had considerable functional mobility limitations. The AMTS, which assessed the cognitive function, revealed normal results in 36.36% of study patients. CONCLUSION: Conclusions: 1. Study patients had significant functional disability. 2. The patients' sex did not influence the ability to perform complex activities of daily living. 3. Sociodemographic determinants did not influence cognitive functioning. 4. Physical therapy and rehabilitation in the elderly should be performed on a regular basis and in the entire society.

High-Resolution Fluorescence Spectra of Airborne Biogenic Secondary Organic Aerosols: Comparisons to Primary Biological Aerosol Particles and Implications for Single-Particle Measurements.

Aqueous extracts of biogenic secondary organic aerosols (BSOAs) have been found to exhibit fluorescence that may interfere with the laser/light-induced fluorescence (LIF) detection of primary biological aerosol particles (PBAPs). In this study, we quantified the interference of BSOAs to PBAPs by directly measuring airborne BSOA particles, rather than aqueous extracts. BSOAs were generated by the reaction of d-limonene (LIM) or α-pinene (PIN) and ozone (O3) with or without ammonia in a chamber under controlled conditions. With an excitation wavelength of 355 nm, BSOAs exhibited peak emissions at 464-475 nm, while fungal spores exhibited peak emissions at 460-483 nm; the fluorescence intensity of BSOAs with diameters of 0.7 µm was in the same order of magnitude as that of fungal spores with diameters of 3 µm. The number fraction of 0.7 µm BSOAs that exhibited fluorescence above the threshold was in the range of 1.9-15.9%, depending on the species of precursors, relative humidity (RH), and ammonia. Similarly, the number fraction of 3 µm fungal spores that exhibited fluorescence above the threshold was 4.9-36.2%, depending on the species of fungal spores. Normalized fluorescence by particle volumes suggests that BSOAs exhibited fluorescence in the same order of magnitude as pollen and 10-100 times higher than that of fungal spores. A comparison with ambient particles suggests that BSOAs caused significant interference to ambient fine particles (15 of 16 ambient fine particle measurements likely detected BSOAs) and the interference was smaller for ambient coarse particles (4 of 16 ambient coarse particle measurements likely detected BSOAs) when using LIF instruments.

Toxicity of soil antimony to earthworm Eisenia fetida (Savingy) before and after the aging process.

Information on soil antimony (Sb) toxicity to earthworm Eisenia fetida (Savingy) is limited. This ecotoxicology study was designed to quantify the soil Sb toxicity to earthworm E. fetida before and after aging process, establishing dose-effect relationship between Sb content and mortality. Results of the avoidance test and acute test showed that the values of net avoidance response, escape rate and mortality were generally decreased in aged treatment compared to that in fresh treatment, respectively from 93.33% to 66.67%, 36.67% to 13.33% and 100% to 53.33% (15 d) taking TL800 (treatment level of 800 mg/kg) for example, meanwhile the values of median lethal content (LC50) at 72 h, 7 d and 15 d were respectively increased from 355.27 mg/kg to 2324.55 mg/kg, 322.19 mg/kg and 1743.19 mg/kg and 282.74 mg/kg to 745.94 mg/kg, indicating that aging process could reduce the Sb acute toxicity to earthworm. According to a three-step sequential extraction procedure, the bioavailable Sb ranged from 24.45% to 43.24% and 16.97% to 27.70% in fresh treatment and aged treatment, respectively, and the mortality of earthworm for 24 h decreased with the decrease of the content of mild acid-soluble antimony (which decreased averagely from 23.09% to 14.00%), which was more suited to assess Sb toxicity. This is the first report that confirms the toxicity of soil Sb to earthworm E. fetida as well as the considering of aging process and speciation.

The Effect of Aging on the Roughness and Bacterial Adhesion of Lithium Disilicate and Zirconia Ceramics.

PURPOSE: This in vitro study was designed to compare bacterial adhesion to zirconia versus lithium disilicate crowns after artificial aging. MATERIALS AND METHODS: Seventy-five discs were tested in this study: 25 Cr-Co base metal discs (control), 25 zirconia discs, and 25 lithium disilicate discs. Each sample was polished and glazed appropriately. The discs were subjected to 1000 thermal cycles between 5 and 55°C, whereby samples stayed in the bath for 20 seconds, at each temperature. Then, 10 µL of Streptococcus sanguinis suspension was placed on the discs. The samples were scanned for surface roughness before and after aging, and after incubation. Sp and Sa were measured with a confocal, visible light disk-scanning system (Sa expresses the difference in height of each point compared to the arithmetical mean of the surface. Sp is the height of the highest peak within the defined area). Optical density of the discs was evaluated by a spectrophotometer. One-way ANOVA was performed to assess differences after aging and incubation. RESULTS: Statistical analysis showed significant differences (p = 0.02) in surface roughness between the Cr-Co base metal, zirconia and lithium disilicate before and after aging. The mean Sa was 0.36 ± 0.12 µm, 0.638 ± 0.24 µm, and 1.23 ± 0.42 µm, respectively. Lithium disilicate had the highest surface roughness values. There was a significant difference (p = 0.001) after incubation. The mean and standard deviation surface roughness of Cr-Co base metal, zirconia and lithium disilicate were 0.99 ± 0.49 µm, 1.40 ± 0.46 µm, and 2.44 ± 1.21 µm, respectively. While no significant differences were found in the accumulation of S. sanguinis between zirconia and lithium disilicate, there was a significant difference (p = 0.02) in the optical density between these 2 test groups and the control group (metal). The optical density of metal (0.94 ± 0.15) was higher than for lithium disilicate (0.74 ± 0.10) and zirconia (0.75 ± 0.08). There was no statistical difference in bacterial adherence between lithium disilicate and zirconia. CONCLUSION: Dental crown materials differed significantly in terms of surface roughness and bacterial adhesion between Cr-Co base metal and zirconia and lithium disilicate. After aging and bacterial adherence, the zirconia discs had the smoothest surface, with similar bacterial accumulation as lithium disilicate; suggesting that lithium disilicate may be less sensitive to bacterial adhesion than zirconia.