Acid Deposition Research Articles

Spatiotemporal distribution in chemical composition of wet atmospheric deposition in Bandung Indonesia.

Bandung, Indonesia, represents the complex interactions between climate variability, basin topography, and deposition processes. This study conducted a long-term spatiotemporal analysis, including pH distribution and pollutant accumulation monitoring, to observe the chemical composition of wet deposition in Bandung as part of the Acid Deposition Monitoring Network in East Asia (EANET). The results revealed that and were the predominant ions, followed by , with their distribution varying across different sites due to local emissions and atmospheric processes. The interactions between these ions, particularly the formation of secondary inorganic aerosols such as ammonium sulfate and ammonium nitrate, were closely linked to the basin's localized sources and topographical features. Areas experiencing high traffic congestion were classified as acidic regions due to their low pH levels. In contrast, a rural site exhibited a basic pH due to the high concentration of ion . Variations in pH and conductivity, along with the impacts of climatic events such as El Niño and La Niña, emphasized the role of weather patterns in shaping wet deposition dynamics. Seasonal trends indicated elevated total ion concentrations during the dry season, driven by sea salt contributions, as supported by strong correlations between Na+ and and between Na+ and Mg2+. Additionally, geological materials and atmospheric reactions contributed to the strong correlations observed between soil-derived cations and acidic species. The increasing trend in and the contrasting decrease in concentrations in rural areas suggest evolving emission sources and environmental conditions.

Effects of Key Rumen Bacteria and Microbial Metabolites on Fatty Acid Deposition in Goat Muscle

In this study, the fatty acid composition in the muscles of Hechuan white goats was correlated with the metabolome and metagenome of their rumen contents, and potential effects of the metabolites and microorganisms in the rumen on host muscle fatty acid deposition were analyzed. The results of the correlation analysis between the rumen content’s metabolome and muscle fatty acid content showed that vitamin-B-related metabolites were significantly correlated with fatty acid content (p < 0.05). Most of these metabolites were positively correlated with stearic acid and negatively correlated with palmitic acid. In accordance with the level of fatty acid content, significant differences were found in the microbial species and abundance among groups at the species level. An abundance of Bacteroides, Ruminococcaceae P7, Eubacterium ruminant, and Prevotella in the rumen was significantly correlated with fatty acid content. These results provide data support for the development of targeted feeding management strategies to improve the quality of goat meat.

Several Mechanisms Drive the Heterogeneity in Browning Across a Boreal Stream Network

AbstractOver the past few decades, many catchments in Northern hemisphere have experienced increases in dissolved organic carbon (DOC) concentrations, resulting in a brownish color of the water, known as aquatic browning. Several mechanisms have been proposed to explain browning, but consensus regarding the relative importance of recovery from acid deposition, climate change, and land management remains elusive. To advance our understanding of browning mechanisms, we explored DOC trends across 13 nested boreal catchments, leveraging concurrent hydrological, chemical, and terrestrial ecosystem data to quantify the contributions of different drivers on observed trends. We first identified the related environmental factors, then attributed the individual trends of DOC to potential drivers across space and time. Our results showed that all catchments exhibited increased DOC trends from 2003 to 2021, but the DOC response rates differed by five‐fold. No single mechanism could fully explain the browning; instead, sulfate deposition, climate‐related factors, and site properties jointly controlled the variation in DOC trends. Specifically, the long‐term increases in DOC were primarily driven by recovery from sulfate deposition, followed by increases in terrestrial productivity, temperature, and discharge. However, catchment area and landcover type also regulated the response rate of DOC to these drivers, creating spatial heterogeneity in browning among sub‐catchments despite similar deposition and climate forcing. Interestingly, browning has weakened in the last decade as sulfate deposition has fully recovered and other current drivers are insufficient to sustain the long‐term increases. Our results highlight that multifaceted, spatially structured, and nonstationary drivers must be accounted for to predict future DOC changes.

Exploring Tissue Permeability of Brain Tumours in Different Grades: Insights from Pore-scale Fluid Dynamics Analysis

Interstitial fluid (ISF) flow is identified as an essential physiological process that plays an important role in the development and progression of brain tumours. However, the relationship between the permeability of the tumour tissue, a complex porous medium, and the interstitial fluid flow around the tumour cells at the microscale is not well understood. To shed light on this issue, and in the absence of experimental techniques that can provide direct measurements, we develop a computational model to predict the tissue permeability of brain tumours in different grades by analysing the ISF flow at the pore scale. The 3-D geometrical models of tissue extracellular spaces are digitally reconstructed for each grade tumour based on their morphological properties measured from microscopic images. The predictive accuracy of the framework is validated by experimental results reported in the literature. Our results indicate that high-grade brain tumours are less permeable despite their higher porosity, whereas necrotic areas of glioblastoma are more permeable than the viable tumour areas. This implies that tissue permeability is primarily governed by both tissue porosity and the deposition of hyaluronic acid (HA), a key component of the extracellular matrix, while the HA deposition can have a greater effect than macro-level porosity. Parametric studies show that tissue permeability falls exponentially with increasing HA concentration in all grades of brain tumours, and this can be captured using an empirically derived relationship in a quantitative manner. These findings provide an improved understanding of the hydraulic properties of brain tumours and their intrinsic links to tumour microstructure. This work can be used to reveal the intratumoural physiochemical processes that rely on fluid flow and offer a powerful tool to tune textured and porous biomaterials for desired transport properties. Statement of SignificanceInterstitial fluid flow in the extracellular space of brain tumours plays a crucial role in their progression, development, and response to drug treatments. However, the mechanisms of interstitial fluid transport around tumour cells and the characterization of these microscale transports at the tissue scale to meet clinical requirements are largely unknown. In the absence of advanced experimental techniques to capture these pore-scale transport phenomena, we have developed and validated a computational framework to successfully reveal these phenomena across all grades of brain tumours. For the first time, we have quantitatively determined the tissue permeability of all grades of brain tumours as a function of the concentration of hyaluronic acid, a key component of the extracellular matrix. This framework will enhance our ability to capture the intratumoural physicochemical processes in brain tumours and correlate them with tumour tissue-scale behaviours.

Large scale study on PFASs levels in fruits, vegetables and soil from allotments and gardens contaminated by atmospheric deposition from a Dutch fluorochemical production plant

Citizens grow their own fruits and vegetables in allotment gardens in the vicinity of a fluorochemical production plant (FCPP) in The Netherlands. Historic emissions and the subsequent atmospheric deposition of perfluorooctanoic acid (PFOA) and GenX (hexafluoropropylene oxide-dimer acid / HFPO-DA) from the FCPP have resulted in the nearby environment being contaminated with per- and polyfluoroalkyl substances (PFASs). This research aimed to investigate the levels of PFASs in garden produce and whether a gradient can be observed in relation to distance from the FCPP. Furthermore, differences between certain types of fruits and vegetables were explored, as well as a potential relation between the measured concentrations in garden produce and soil. 737 fruit and vegetable samples were collected from 17 allotments and 4 gardens up to 20 kilometres from the FCPP, along with soil and water samples. Garden produce included fruits, potatoes, fruiting vegetables, brassicas, leafy vegetables, root vegetables, bulb vegetables, legumes and stem vegetables. PFASs concentrations in the samples were quantified using a very sensitive UPLC-MS/MS method. PFASs were detected in most samples above the analytical limit of detection (0.3 to 12.5 pg/g ww). PFOA and GenX were found in the highest concentrations (up to 5280 pg/g ww GenX and 3020 pg/g ww PFOA) in garden produce sampled downwind and close to the FCPP. Other PFASs were also found, but at (much) lower levels. Field-derived bioaccumulation factors (BAFs) were calculated for PFOA and GenX. The BAFs for PFOA were shown to be approximately 1 order of magnitude lower than BAFs from other studies. This may be explained by aging of the PFASs contamination and the intense cultivation of the garden plots. This study shows that PFOA and GenX can end up in garden produce and this will result in human exposure when the garden produce is consumed.

Nitisinone attenuates progression of aortic stenosis in patients with alkaptonuria: an analysis of the SONIA 2 study

Abstract Background/introduction Alkaptonuria (AKU) is a rare metabolic disorder caused by a defective enzyme, resulting in deposition of unmetabolised homogentisic acid in various connective tissues throughout the body (also termed "ochronosis"). Ochronosis of the aortic valve leading to progressive aortic stenosis is a rare but serious complication. Nitisinone decreases urinary and serum homogentisic acid levels and has been shown to improve morbidity and slow disease progression in AKU but the effects of this treatment on the progression of aortic stenosis have not yet been described. This review extrapolated from the data set of the SONIA 2 study, a 4-year multi-centre, randomised controlled trial investigating the effect of nitisinone on a composite clinical measure of AKU disease activity, but looked more specifically at measures of aortic stenosis disease progression. Methods Data was obtained from echocardiograms performed on 138 patients at baseline, 12, 24, 36 and 48 months of follow-up. In measuring the degree of aortic stenosis, the peak trans-aortic velocity (Vmax) was examined. A linear mixed effects regression model was used to assess the association between treatment and Vmax and to ascertain the difference in this measure at baseline and 48 months between the treatment and control groups. The mixed effects model incorporated both fixed effects for population parameters (age, sex, baseline Vmax, follow-up time) and treatment; and random effects, to account for intra-subject correlation of longitudinal observations of Vmax, inter-subject variability of baseline measurements of Vmax, and centre. Results At baseline, 19/138 patients (13.8%) had aortic stenosis, as classified by echocardiogram findings in accordance with the European Society of Cardiology (ESC) guidance on valvular heart disease, with 9/19 having mild aortic stenosis, 6/19 having moderate aortic stenosis and 4/19 having severe aortic stenosis. 25/138 had aortic sclerosis (see figure 1). The prevalence of aortic valve disease increased with age. From the 4-year follow-up period, 613 longitudinal observations of 138 subjects across all sites were obtained. At baseline, the difference in Vmax between the control and treatment groups was 0.063 m/s [95% CI: -0.054 m/s to 0.18 m/s] and did not reach statistical significance (p=0.23). At the end of the 4-year treatment period, the difference in Vmax was 0.10 m/s [95% CI: -0.0007 m/s to 0.20 m/s] and was statistically significant (p=0.05) (see figure 2). Conclusion Nitisinone slowed progression of aortic stenosis in patients with AKU. This may be grounds for timely initiation of nitisinone in those deemed to be at high risk, as identified by echocardiography. Of note, this is the first time that any medical therapy has ever been shown to affect the natural history of aortic stenosis.

The role of dissolved organic carbon in Great Smoky Mountains National Park streams impacted by long-term acid deposition.

Following reductions in acid deposition in the Great Smoky Mountains National Park (GRSM) since the 2000s, many streams remain acidic and the role of organic acids (OA-) remains unknown due to limited OA- data. This study investigated dissolved organic carbon (DOC) concentrations as a surrogate for OA- across GRSM and its relationships with watershed characteristics, seasons, flow, and stream chemistry. Baseflow water samples were collected from seven watersheds for 2years and stormflow samples from three watersheds for 1year. During baseflow, DOC concentrations ranged from < 0.04 to 2.29mg L-1 with watershed medians between 0.61 and 1.00mg L-1. Stormflow DOC concentrations ranged from 1.36 to 5.66mg L-1. During the summer, median DOC concentrations were about twice that of the other three seasons. Stream DOC concentrations decreased with increasing elevation during baseflow but increased with increasing elevation during stormflow. Considering high elevations historically received greater acid deposition, this gradient between baseflow and stormflow suggests higher elevation streams are more impacted by OA-. Based on an OA-/DOC acidity model, it was estimated that during baseflow OA- was a minor contributor to stream acidity, in the order of 5.3 μeq L-1, however stormflow OA- was estimated at 52.5 μeq L-1, contributing to nearly half of stream acidity. Baseflow DOC was significantly correlated with pH and Ca2+, suggesting stream acidification/recovery is governed by base cations and Ca2+ availability. Furthermore, this study provides essential data for future research to evaluate stream DOC trends during acidification recovery and changes in biogeochemical processes.

Identification and Functional Characterization of the FATP1 Gene from Mud Crab, Scylla paramamosain.

In mammals, fatty acid transport protein 1 (FATP1) plays important roles in cellular uptake and activation of long-chain fatty acid (LCFA), especially in processes of transportation, oxidation and triacylglycerol synthesis. However, the role of FATP1 in invertebrates, especially decapod crustaceans, is still poorly understood. In this study, the cDNA of a FATP1 gene from a decapod crustacean, mud crab Scylla paramamosain, was cloned and functionally characterized. The FATP1 gene encoded a polypeptide consisting of 643 amino acids that exhibits all the typical features of the FATP family and shares high homology with the other FATP orthologs of crustaceans. The relative mRNA expression levels of FATP1 were observed to be higher in metabolically active tissues such as hepatopancreas, stomach and gill than in other crab parts. Knockdown of the FATP1 mRNA in vivo significantly reduced triacylglycerols and total lipid levels in the hepatopancreas, accompanied by an increase in the expression of genes related to fatty acid transportation, allocation and hydrolysis, including long-chain acyl-CoA synthetase 3/4 (ACSL3/4) and carnitine palmitoyl transferase 1 (CPT1), and a decrease in the expression of genes related to fatty acid synthesis such as acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS) in the hepatopancreas. Furthermore, increased dietary n-3 long-chain polyunsaturated fatty acid (LC-PUFA) levels resulted in the up-regulation of the FATP1 expression in the hepatopancreas, accompanied by an increase in LC-PUFA content, especially eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3), in both polar (PLs) and neutral lipids (NLs) in the hepatopancreas and muscles of crabs. These findings suggested that the FATP1 gene identified in S. paramamosain might play important roles in regulating long-chain fatty acid metabolism and deposition in crustaceans.

Complex interactions of deer herbivory, soil chemistry, and competing vegetation explain oak–hickory forest tree regeneration in central Pennsylvania, USA

The root causes of forest tree regeneration failure are difficult to resolve, although numerous studies show ungulate herbivory, soil conditions, and competition from undesirable vegetation as likely contributors. To better understand the relative importance of each issue, we conducted a 7-year manipulative experiment to assess the interactive effects of white-tailed deer ( Odocoileus virginianus) herbivory, soil acidity, and competing vegetation on tree regeneration in oak–hickory forests of central Pennsylvania, USA. Outcomes depended on initial tree seedling abundance, and all three factors had significant interactions. At low initial seedling abundance, fencing resulted in the greatest increase, but all treatments had a positive effect on seedling growth and abundance. At higher initial seedling abundance, abundance failed to recover 7 years after herbicide treatment and soil pH was an important predictor. When soil pH was &gt;4.6 from lime application, seedling growth and abundance in unfenced controls with high initial abundance was comparable to the fenced-only treatment. Competing vegetation, assumed to be a symptom of excessive, long-term deer herbivory, does not seem to be the primary factor limiting tree regeneration in our study area. Ameliorating acid deposition warrants greater consideration as a management action because it could provide long-lasting benefits compared to short-term fence installations.

Textile-based 3D printing and traditional Chinese geometric patterns for fashion textile development

Here, textile-based 3D printing technology is combined with traditional Chinese patterns to create new effects. Traditional Chinese patterns are the main carrier of cultural heritage and have been widely applied as creative design elements to develop unique fashion and textile products. Two geometric patterns inspired by traditional Chinese patterns are developed through the direct deposition of polylactic acid onto polyester fabric. Then the physical and mechanical performances of the printed patterns are examined under a microscope, along with tensile, tear, and joint motion tests. After that, two garment prototypes are created to explore the design aesthetics of the 3D printed geometric patterns. This research work reports on a comprehensive and practical design process for the creation of 3D printed fashion textiles. The work is expected to provide insights for designers and researchers when reviving traditional elements through modern technology. More applications can be explored based on the results reported in this paper.

8802 A Rare Case Of Symptomatic Hypercalcemia In A Patient With Untreated Chronic Tophaceous Gout

Abstract Disclosure: S. Avula: None. A. Kumar: None. Z.J. Anderson: None. A. Chauhan: None. L.T. LaFave: None. Background: Hypercalcemia is a medical condition with abnormally high serum calcium levels. There are numerous mechanisms for the development of hypercalcemia, but gout is not well documented.Hypercalcemia attributed to Tophaceous gout is a rare phenomenon that is not well studied. Here we report a case of symptomatic hypercalcemia in a patient with a history of untreated tophaceous gout, leading to hypercalcemia and osteolytic lesions. Clinical Case: The patient is a 52-year-old male with a medical history of hypertension, rheumatoid arthritis, and tophaceous gout who immigrated from Tanzania. He presented with two weeks of abdominal pain that acutely worsened the morning of his presentation. He reported a 16-year history of tophaceous gout, for which he had been treated with allopurinol without success. On physical examination polyarticular subcutaneous nodules were present in the bilateral upper and lower extremities, primarily over the joints. There were similar lesions on the buttocks. Initial laboratory evaluation included a complete blood count which was notable for a hemoglobin of 10.3 g/dL (13.1 - 17.5 g/dL). His albumin was normal at 4 g/dl. (3.8 - 5.1 g/dl). Serum calcium was elevated at 12.9 mg/dL (8.8-10.0 mg/dL), with a serum ionized calcium level of 6.52 mg/dL(4.40-5.20 mg/dL). PTH was low at 15.8 pg/mL (16.0 - 65.0 pg/mL), and PTHrP was 2.9 pg/ml (&amp;lt;4.5 pg/ml). Uric acid level on admission was elevated to 11.4 mg/dL (3.4 - 7.0 mg/dL). 1-25 dihydroxy vitamin D elevated at 93.2 pg/mL (19.9 - 79.3 pg/mL). Computed tomography (CT) with intravenous contrast of the chest, abdomen, and pelvis was notable for axillary, pelvic, and inguinal lymphadenopathy concerning for lymphoproliferative or neoplastic processes. Biopsy of right inguinal node biopsy showed benign-appearing lymphoid tissue. Additional findings included multiple lobulated calcified hyperdense foci throughout the subcutaneous and muscular tissues of the buttocks with resorptive changes of the axial skeleton. Spectral CT reconstruction determined these to be uric acid deposits. Radiographs of his extremities were consistent with advanced gouty arthropathy. Infectious work-up was negative. Patient was given 3 liters of 0.9% sodium chloride. He received four doses of Calcitonin (4 units/kg) followed by one dose of Zoledronic acid 5 mg I.V. He was treated with Febuxostat, solumedrol and Azathioprine for his tophaceous gouty arthritis. Conclusion: Hypercalcemia is a commonly encountered yet a very important clinical condition. Parathyroid and malignant etiologies of hypercalcemia account for approximately 90% of cases of hypercalcemia. Gout as the inciting factor for developing hypercalcemia is a rarely documented phenomenon. This case highlights hypercalcemia as an unusual yet severe manifestation of untreated chronic gout and demonstrates the need for additional studies and reviews. Presentation: 6/2/2024

Acid deposition promotes soil carbon sequestration in terrestrial ecosystems of China

Acid deposition promotes soil carbon sequestration in terrestrial ecosystems of China

Fluoride-Treated Nano-HZSM-5 Zeolite as a Highly Stable Catalyst for the Conversion of Bioethanol to Propylene.

Fluoride treatment of ZSM-5 zeolite can effectively adjust surface acidity and generate a secondary pore structure. In this study, a series of modified nano-HZSM-5 zeolites were prepared by NH4F-HF mixed solution treatment and applied to the selective conversion of bioethanol to propylene at 500 °C, atmospheric pressure, and a WHSV of 10 h-1. The results showed that NH4F-HF modification weakened the surface acidity of nano-HZSM-5 zeolites, thus inhibiting coke formation. Additionally, the mesopores in the nano-HZSM-5 zeolites increased after NH4F-HF treatment, thereby enhancing the mass transfer rate and improving the coke-resistance ability. The NH4F-HF mixed solution modification significantly improved the stability of nano-HZSM-5 zeolites in catalyzing bioethanol to propylene and greatly extended the working life of nano-HZSM-5 zeolites. It can be seen from the characterization of the deactivated catalysts that coke deposition and weakening of acidity may be the key factors for catalyst deactivation.

Functionalized expanded graphite foam supported by PVDF skeleton for cationic dyes selectively separating and purifying

In order to fully utilize the advantages of expandable graphite (large specific surface area and porous structure), a solvent-free method was used to provide a supporting skeleton for expandable graphite through melting, bonding and solidification of polyvinylidene fluoride (PVDF). Based on its porous structure and enhanced mechanical stability, the formed PVDF/expandable graphite composite foam, amounts of functional groups were introduced throughout the foam (outside on the surface and inner side in the expandable graphite) by deposition of tannic acid (TA) and dopamine (DA), endowing it selective adsorption characteristics. The functioned foam exhibited excellent dynamic dye adsorption capacity by capturing dye molecules firmly through π-π interaction, hydrogen bonding, and charge attraction between the functional groups and dyes. Furthermore, with low zeta potential (-24.9 mV), the functional groups showed selective adsorption properties resulting in rapid separation of cationic dyes and anionic dyes. The functionalized PVDF/expandable graphite composite foam contact these two materials together in order to complement each other's advantages, showing a new research orientation for the treatment of different types of dyestuff wastewater.

Hypoxia and Foxn1 alter the proteomic signature of dermal fibroblasts to redirect scarless wound healing to scar-forming skin wound healing in Foxn1−/− mice

BackgroundFoxn1−/− deficient mice are a rare model of regenerative skin wound healing among mammals. In wounded skin, the transcription factor Foxn1 interacting with hypoxia-regulated factors affects re-epithelialization, epithelial-mesenchymal transition (EMT) and dermal white adipose tissue (dWAT) reestablishment and is thus a factor regulating scar-forming/reparative healing. Here, we hypothesized that transcriptional crosstalk between Foxn1 and Hif-1α controls the switch from scarless (regenerative) to scar-present (reparative) skin wound healing. To verify this hypothesis, we examined (i) the effect of hypoxia/normoxia and Foxn1 signalling on the proteomic signature of Foxn1−/− (regenerative) dermal fibroblasts (DFs) and then (ii) explored the effect of Hif-1α or Foxn1/Hif-1α introduced by a lentiviral (LV) delivery vector to injured skin of regenerative Foxn1−/− mice with particular attention to the remodelling phase of healing.ResultsWe showed that hypoxic conditions and Foxn1 stimulation modified the proteome of Foxn1−/− DFs. Hypoxic conditions upregulated DF protein profiles, particularly those related to extracellular matrix (ECM) composition: plasminogen activator inhibitor-1 (Pai-1), Sdc4, Plod2, Plod1, Lox, Loxl2, Itga2, Vldlr, Ftl1, Vegfa, Hmox1, Fth1, and F3. We found that Pai-1 was stimulated by hypoxic conditions in regenerative Foxn1−/− DFs but was released by DFs to the culture media exclusively upon hypoxia and Foxn1 stimulation. We also found higher levels of Pai-1 protein in DFs isolated from Foxn1+/+ mice (reparative/scar-forming) than in DFs isolated from Foxn1−/− (regenerative/scarless) mice and triggered by injury increase in Foxn1 and Pai-1 protein in the skin of mice with active Foxn1 (Foxn1+/+ mice). Then, we demonstrated that the introduction of Foxn1 and Hif-1α via lentiviral injection into the wounded skin of regenerative Foxn1−/− mice activates reparative/scar-forming healing by increasing the wounded skin area and decreasing hyaluronic acid deposition and the collagen type III to I ratio. We also identified a stimulatory effect of LV-Foxn1 + LV-Hif-1α injection in the wounded skin of Foxn1−/− mice on Pai-1 protein levels.ConclusionsThe present data highlight the effect of hypoxia and Foxn1 on the protein profile and functionality of regenerative Foxn1−/− DFs and demonstrate that the introduction of Foxn1 and Hif-1α into the wounded skin of regenerative Foxn1−/− mice activates reparative/scar-forming healing.

An efficient hole transport layer and novel citrate-FeCo(OH)x cocatalyst co-modified Ti-Fe2O3 photoanode towards boosting photoelectrochemical water oxidation

The restricted performance of α-Fe2O3 in photoelectrochemical (PEC) water splitting is currently constrained by the slow kinetics of water oxidation and the rapid charge recombination. Herein, we prepared a composite photoanode with molecular copper phthalocyanine (CuPc) as the hole transport layer and citric acid assisted FeCo(OH)x as the cocatalyst using a simple two-step method. The optimized Ti-Fe2O3/CuPc/citrate-FeCo(OH)x photoanode achieved an photocurrent density of 2.67 mA/cm−2 at 1.23 V vs. RHE, which is 6.5 times higher than pure Ti-Fe2O3 and can maintain long-term stability. Detailed studies have shown that CuPc and Ti-Fe2O3 can form an interface electric field for hole oriented transport, significantly improving the transfer of photogenerated carriers. The FeCo(OH)x coating assisted by citric acid deposition not only forms a conformal coating, but also acts as a bifunctional layer to quickly transfer holes from Ti-Fe2O3/CuPc to the electrolyte. It also significantly increases the reactive active sites and hydrophilicity of Ti-Fe2O3/CuPc, which further accelerates the water oxidation kinetics. This study provides a promising strategy for the development of an efficient and cost-effective photoanode and extends the design concept of a PEC water splitting device.

Sodium silicate accelerates suberin accumulation at wounds of potato tuber by inducing phenylpropanoid pathway and fatty acid metabolism during healing

Although soluble silicate was reported to accelerate wound healing in muskmelon fruit through encouraging the deposition of lignin or free fatty acids, whether sodium silicate affects the biosynthesis, cross-linking and transport of suberin monomers during potato wound healing remains unknown. In this study, sodium silicate upregulated the expression and activity of 4-coumarate: coenzyme A ligase (4CL), phenylalanine ammonia lyase (PAL), and promoted the synthesis of phenolic acids (caffeic acid, p-coumaric acid, cinnamic acid, sinapic acid, and ferulic acid) in tuber wounds. Meanwhile, sodium silicate upregulated the expression of glycerol-3-phosphate acyltransferase (StGPAT), fatty acyl reductase (StFAR), long-chain acyl-CoA synthetase (StLACS), β-ketoacyl-CoA synthase (StKCS), and cytochrome P450 (StCYP86A33), and thus increased the levels of α, ω-diacids, ω-hydroxy acids, and primary alcohols in wounds. Sodium silicate also induced the expression of ω-hydroxy acid/fatty alcohol hydroxycinnamoyl transferase (StFHT), ABC transporter (StABCG), and promoted the deposition of suberin in wound surface, hence reducing tuber disease index and weight loss during healing. Taken together, sodium silicate may accelerate suberin accumulation at potato tubers wound through inducing the phenylpropanoid pathway and fatty acid metabolism.

Modeling Indoor Inorganic Aerosol Concentrations During the ATHLETIC Campaign with IMAGES.

In 2018, the ATHLETIC campaign was conducted at the University of Colorado Dal Ward Athletic Center and characterized dynamic indoor air composition in a gym environment. Among other parameters, inorganic particle and gas-phase species were alternatingly measured in the gym's supply duct and weight room. The Indoor Model of Aerosols, Gases, Emissions, and Surfaces (IMAGES) uses the inorganic aerosol thermodynamic equilibrium model, ISORROPIA, to estimate the partitioning of inorganic aerosols and corresponding gases. In this study herein, measurements from the ATHLETIC campaign were used to evaluate IMAGES' performance. Ammonia emission rates, nitric acid deposition, and particle deposition velocities were related to observed occupancy, which informed these rates in IMAGES runs. Initially, modeled indoor inorganic aerosol concentrations were not in good agreement with measurements. A parametric investigation revealed that lowering the temperature or raising the relative humidity used in the ISORROPIA model drove the semivolatile species more toward the particle phase, substantially improving modeled-measured agreement. One speculated reason for these solutions is that aerosol water was enhanced by increasing the RH or decreasing the temperature. Another is that thermodynamic equilibrium was not established in this indoor setting or that the thermodynamic parametrizations in ISORROPIA are less accurate for typical indoor settings. This result suggests that applying ISORROPIA indoors requires further careful experimental validation.

Variations of dissolved trace elements in precipitation and stream water in Japanese forest area: additional evidence of changing air pollution in the region

Trace elements released into the atmosphere by human activities, such as fossil fuel combustion, flow into forest ecosystems via wet and dry deposition and can flow out via mountainous stream water. The Kajikawa catchment site in Niigata Prefecture, located on the Sea of Japan side in central Japan, suffers from large amounts of acidic substance deposition due to its geographical conditions and meteorological seasonality and is affected by transboundary air pollution originating from the Asian continent due to northwesterly seasonal winds in winter. This study determined the concentrations of trace elements dissolved in precipitation and stream water to comprehensively evaluate the effects of transboundary air pollution on forest ecosystems. The results showed that the concentrations of trace elements and major inorganic ions in precipitation tended to be high in winter and low in summer. The fluxes of many trace elements also increased in winter, reflecting high precipitation amount. Except for Sr, the enrichment factors of the highly enriched trace elements did not show clear seasonality. Therefore, they were continuously influenced by anthropogenic activities. Furthermore, the stable Pb isotope ratio changed significantly during the observation period; however, this was not explained by seasonal changes. This study revealed that trace elements are transported to the Sea of Japan side in central Japan, especially in winter; however, their quantity and content change in response to changes in local and transboundary air pollution.Graphical

Diatom dynamics during the last six centuries in Lake Odensjön: a new varved sediment record from southern Sweden

AbstractVarved lake sediments offer valuable insight into past environmental conditions with high temporal resolution and precise chronological control. A combination of diatom and geochemical analyses of the recently deposited sediments of Odensjön, a small dimictic lake in southern Sweden, shows alternating light and dark laminae composed of greater amounts of biogenic silica and organic matter, respectively. As confirmed by independent radiometric dating and Pb pollution data, and supported by scanning electron microscopy of individual laminae, these features represent ongoing deposition of biogenic varves. Corresponding diatom and geochemical data obtained from a 92-cm long freeze core provide evidence of substantial lake-ecosystem dynamics during the last six centuries, related mainly to variations in light penetration and wind shear driven by human-induced changes in catchment vegetation. The diatom assemblage of Odensjön’s varved sediments is dominated by planktonic species, primarily Asterionella formosa, Fragilaria saxoplanktonica and Discostella lacuskarluki during periods of forest cover, while increased catchment openness from the mid-1500s to the late 1800s led to increased abundance of Lindavia comensis. Long-term variations in climate and land use, mediated through changing length of the ice-cover season and nutrient input, respectively, probably contributed to the observed trends, as well as to variations in the appearance and visibility of the varve record across the sampled sediment sequence. Odensjön represents the southernmost varved sediment record in Fennoscandia documented to date, offering potential to study the effects of various types of external forcing on its sensitive lacustrine ecosystem since the Late Weichselian deglaciation. In the present study, we investigated the possibility of assessing the local impacts of two major, historically documented volcanic events, Laki 1783–84 and Tambora 1815, which are known to have affected European societies. Although the mildly alkaline waters of the lake are well buffered and hence relatively resilient to volcanic acid deposition, a minor response to the Laki eruption may be recorded in the diatom stratigraphy.