Guangzhou Institute of Geochemistry
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Molecular characteristics of organic matters in PM 2.5 associated with upregulation of respiratory virus infection<i> in</i><i> vitro</i>
No full textThe extent to which organic matters (OM) in PM 2.5 affect virus infections and the key organic molecules involved in this process remain unclear. Herein, this study utilized ultra-high resolution mass spectrometry coupled with in vitro experiments to identify the organic molecules associated with respiratory virus infection for the first time. Water-soluble organic matters (WSOM) and water-insoluble organic matters (WIOM) were separated from PM 2.5 samples collected at the urban area of Guangzhou, China. Their molecular compositions were analyzed using Fourier transform ion cyclotron resonance mass spectrometry. Subsequently, in vitro experiments were conducted to explore the impact of WSOM and WIOM exposure on the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pseudo-virus infection in A549 cells. Results revealed that WSOM and WIOM respectively promoted 1.7 to 2.1-fold and 1.9 to 3.5-fold upregulation of SARS-CoV-2 pseudo-virus infection in a concentration- dependent manner (at 25 to 100 mu g mL-1) compared to the virus-only control group. Partial least squares model analysis indicated that the increased virus infection was likely related to phthalate ester and nitro-aromatic molecules in WSOM, as well as LipidC molecules with aliphatic and olefinic structures in WIOM. Interestingly, the molecules responsible for upregulating SARS-CoV-2 receptor angiotensin-converting enzyme 2 ( ACE2 ) expression and virus infection differed. Thus, it was concluded that ACE2 upregulation alone may not fully elucidate the mechanisms underlying increased susceptibility to virus infection. The findings highlight the critical importance of aromatic and lipid molecules found in OM in relation to respiratory virus infection
Unravelling the mechanisms underlying marine redox shifts during sedimentary manganese metallogenesis: insights from the Carboniferous Muhu deposit, China
No full textSedimentary manganese (Mn) mineralization requires a switch between anoxic and oxic water column conditions, which is commonly explained by the "bathtub ring" model and more recently interpreted by the emerging "episodic ventilation" model. To date, however, it remains unclear regarding how to distinguish between these two mechanisms, profoundly influencing Mn ore prospecting. Here, we conducted a comprehensive investigation on the Muhu Mn deposit in northwestern China. The upward lithological variations from breccia-dominated to fine-grained siliciclastic units (e.g., black shales) are typical of sequence characteristics of rifted basins. Black shales were deposited in deep waters due to continued tectonic subsidence that resulted in hydrographic restriction and bottom water euxinia, as indicated by their high ratios of FeHR/FeT and FePy/FeHR, as well as relatively low Mo/TOC ratios. The Mn ore beds are interbedded with black shales and consist of divalent Mn minerals (e.g., rhodochrosite). They display shale-normalized positive cerium anomalies and negative inorganic carbon isotopes and Mo isotopes, suggesting that these Mn carbonate minerals originated from the diagenetic conversion of primary buried Mn oxides deposited under oxic benthic conditions. Taken together, the intimate spatial association between Mn ore beds and black shales records a dynamic temporal redox change. Such a redox shift is consistent with the "episodic ventilation" scenario, where incursions of oxygenated seawater triggered the deposition of initial Mn oxides. In contrast with the "bathtub ring" model, the ventilation scenario represents distinct spatial-temporal configurations of redox-hydrological conditions. Therefore, deciphering the detailed redox variations of Mn-hosting sedimentary successions, in conjunction with paleogeographic reconstruction, is the key to distinguishing between these two mechanisms
Apatite low-temperature thermochronology constraints on the Cenozoic differential uplift/denudation of the Ke'eryin lithium ore field in western China: Implications for lithium exploration
No full textThe Ke'eryin pegmatite-type lithium ore field is a major lithium concentration area in the Songpan-Garze fold belt, western China. However, there is a notable spatial variability in lithium mineralization, with the northeastern and southeastern regions showing higher mineralization intensity than the western and northern parts. Previous studies suggest that this difference is likely related to the development of a Cenozoic thrust fault, the Ke'eryin thrust fault (KEYF), which traverses the eastern and southern parts of the ore field. However, direct chronological evidence is lacking. This study employs apatite fission track thermochronology on three representative deposits located in the northeastern, southeastern, and western regions of the Ke'eryin ore field, offering insights into differential uplift/denudation. The integration of regional tectonic evolution, apatite fission track age data, and thermal modelling results reveals that the Ke'eryin ore field has underwent two primary phases of rapid cooling after its formation: initially from the Late Jurassic to the Cretaceous, and subsequently from the Early Miocene to the present. The initial rapid cooling phase is mainly attributed to the LhasaQiangtang collision, whereas the subsequent phase is connected to significant fault activity and regional river incision due to the India-Asia continental collision. Apatite fission track age data and thermal modelling results indicate that differential uplift/denudation between the eastern and western Ke'eryin ore field primarily took place during the Late Miocene of the Cenozoic. The development of the thrust fault, which has been constrained to have initiated since 12 Ma, has led to the denudation of lithium deposits in the hanging wall (the western and northern parts of the Ke'eryin ore field), whereas those in the footwall (the eastern part) remain relatively well preserved. Based on these characteristics, this study recommends focusing exploration efforts for pegmatite-type lithium resources in the footwall regions, particularly in exploration gaps that are away from river valleys between large and super-large deposits. Additionally, in the entire Songpan-Garze fold belt, there is significant pegmatite-type lithium exploration potential in the high elevation, arid, and less topographically relieved western regions
Apatite low-temperature thermochronology constraints on the Cenozoic differential uplift/denudation of the Ke'eryin lithium ore field in western China: Implications for lithium exploration
No full textThe Ke'eryin pegmatite-type lithium ore field is a major lithium concentration area in the Songpan-Garze fold belt, western China. However, there is a notable spatial variability in lithium mineralization, with the northeastern and southeastern regions showing higher mineralization intensity than the western and northern parts. Previous studies suggest that this difference is likely related to the development of a Cenozoic thrust fault, the Ke'eryin thrust fault (KEYF), which traverses the eastern and southern parts of the ore field. However, direct chronological evidence is lacking. This study employs apatite fission track thermochronology on three representative deposits located in the northeastern, southeastern, and western regions of the Ke'eryin ore field, offering insights into differential uplift/denudation. The integration of regional tectonic evolution, apatite fission track age data, and thermal modelling results reveals that the Ke'eryin ore field has underwent two primary phases of rapid cooling after its formation: initially from the Late Jurassic to the Cretaceous, and subsequently from the Early Miocene to the present. The initial rapid cooling phase is mainly attributed to the LhasaQiangtang collision, whereas the subsequent phase is connected to significant fault activity and regional river incision due to the India-Asia continental collision. Apatite fission track age data and thermal modelling results indicate that differential uplift/denudation between the eastern and western Ke'eryin ore field primarily took place during the Late Miocene of the Cenozoic. The development of the thrust fault, which has been constrained to have initiated since 12 Ma, has led to the denudation of lithium deposits in the hanging wall (the western and northern parts of the Ke'eryin ore field), whereas those in the footwall (the eastern part) remain relatively well preserved. Based on these characteristics, this study recommends focusing exploration efforts for pegmatite-type lithium resources in the footwall regions, particularly in exploration gaps that are away from river valleys between large and super-large deposits. Additionally, in the entire Songpan-Garze fold belt, there is significant pegmatite-type lithium exploration potential in the high elevation, arid, and less topographically relieved western regions
Chemical characteristics, source apportionment of precipitation ion and the response to air quality in Kunming, southwest monsoonal area of China
No full textChemical composition (ion) of precipitation contains the information of atmospheric pollution, provides key scientific evidence for improving air quality and deposition flux to ecological environmental assessment in study region. The ion concentrations of 99 precipitation events (January 2013 to December 2014) in Kunming (southwest monsoonal region of China) were reported here with detailed study on the ion characteristics, sources tracing and influencing factors by correlation analysis (SPSS software), Positive Matrix Factorization (PMF) and Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) models analysis. The results showed that the major ions were NH4+, Ca2+, SO42- and NO3-, accounting for 81% of the total ions. PMF model results estimated six sources: secondary inorganic product, metal-cement industrial source, construction dust source, chlorination industrial source, marine source and biomass combustion source. In addition, HYSPLIT results showed that Kunming was mainly affected by five air masses, with highest ionic flux from the southwest direction (Indian Ocean). The annual average concentration of precipitation ions from 2013 to 2020 show positive relationships to air quality index (AQI), which indicate that precipitation ions can record different types of human activities (i.e. "coal ban", energy structure transformation, fertilizer usage, etc.) contribute to AQI
From holocene to anthropogenic impact: Surpassing coral's pH up-regulation capacity under ocean acidification
No full textCorals' regulation of internal calcifying fluid (CF or cf) chemistry is crucial for their extraordinary calcification capacity, endowing them with a certain ability to cope with environmental changes such as anthropogenic ocean acidification (OA) and warming. However, it remains unclear whether the impacts of these changes on corals have substantially surpassed their regulation capacity, particularly in comparison to the CF chemistry responses to natural climate variability with minor or no human perturbation. In this study, we reconstructed the pH, dissolved inorganic carbon, and carbonate ion concentrations in coral CF (pH(cf), DICcf, and [CO32-](cf)) during the Mid- to Late-Holocene, by analyzing the skeletal delta B-11 and B/Ca of 80 Porites spp. from eastern Hainan Island in the South China Sea (SCS). Our records indicate considerable inter-colony variations in CF chemistry, with maximum disparities reaching 0.18 units for pH(cf) and 1664 mu mol/kg for DICcf. With this in mind, we found no clear responses of coral DICcf to the climate fluctuations during the past similar to 5500 years, nor evident differences in pH(cf) and [CO32-](cf) across pre-industrial natural epochs. However, pH(cf) and [CO32-](cf) of modern corals have significantly declined compared to fossil corals. Further analyzes compiling global data on Porites spp. also confirm this pronounced pH(cf) decrease in modern corals, suggesting the limitations of pantropical corals to counteract OA by up-regulating pH(cf). Importantly, these fossil and modern corals reveal a clear long-term pH(cf) descending trend parallel to atmospheric CO2 changes, supporting the reliability of coral delta B-11 in recording long-term changes in seawater pH (pH(sw))
Accumulation of lipophilic and proteinophilic halogenated organic pollutants (HOPs) in the different types of feathers of laying hens
No full textThis study investigated the bioaccumulation of halogenated organic pollutants (HOPs) in three types of feathers from laying hens through exposure experiments. The HOPs included lipophilic polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs), as well as proteinophilic perfluoroalkyl carboxylic acids (PFCAs). Concentrations of PCBs, PBDEs, and short-chain PFCAs (8) showed no significant differences among primary, tail, and body feathers. The concentration order in the feathers was & sum;12PFCAs > & sum;7PBDEs > & sum;(13)PCBs, which was completely reversed by the exposure dose. The transfer rates (TRs) (concentration ratio of feather to serum) of PFCAs (0.11-6.8) were one order of magnitude higher than those (0.01-0.30) of PCBs and PBDEs. These results indicate that PFCAs preferentially accumulate in feathers compared to PBDEs and PCBs. TRs, regardless of whether they were lipophilic or proteinophilic HOPs, were significantly and positively correlated with the protein-water partition coefficient (log K-pw). Strong and significant correlations between feathers and inner tissues were primarily observed in body feathers. Egg-laying significantly affects PFCA accumulation in feathers and even distorts the actual exposure dose in hens; however, its impact on PCBs and PBDEs is limited. These findings provide crucial insights into HOP deposition in bird feathers
Stable Nd isotopic fractionation in REY-rich deep-sea sediments
No full textStable Nd isotope ratios are regarded as a potential tracer for marine rare earth elements (REEs) cycling. However, the fractionation behavior of Nd in marine geological processes has not yet been constrained. This study investigates the bulk and leachate compositions (phosphate, Fe-Mn oxides, and aluminosilicates) of a Ndenriched deep-sea sediment core in the western Pacific for both the stable and radiogenic Nd isotopes. The epsilon Nd values of the bulk sediments range from -6.2 to -5.1, indicating a basically consistent source material throughout the core. Compared to the Bulk Silicate Earth (BSE), the core shows enrichment in heavy Nd isotopes, suggesting that marine authigenic components play a key role in controlling the stable Nd isotope behavior. In the phosphate phase, Nd content correlates positively with P2O5 and CaO contents (R2 = 0.97 and R2 = 0.96, respectively), while the stable Nd isotopic compositions exhibit limited variability (0.076 %o +/- 0.055 %o), suggesting that phosphates have the potential to reconstruct the stable Nd isotope composition of paleo-seawater. For Fe-Mn oxide phases, Mn content initially correlates with Nd content and stable Nd isotope composition, and then exhibit a negative relationship, which suggests that Fe-Mn (hydr)oxides initially adsorb heavier 146Nd from seawater and subsequently release it into pore water. The bulk sediment illite abundance and Al2O3 content correlate with bulk Nd content (R2 = 0.55 and R2 = 0.62, respectively) in aluminosilicate phases, but not with stable Nd isotope composition, indicating that illite controls Nd distribution within this phase without causing stable isotope fractionation. These results elucidate the behavior of stable Nd isotope fractionation in REY-rich deep-sea sediments and provide a fundamental understanding of stable Nd isotopes as a tracer for marine REEs cycling
A prominent oxygenation event in the late Mesoproterozoic broke the calm of the second half of the "Boring Billion"
No full textThe redox conditions on Earth's surface during the so-called "Boring Billion" (ca. 1.8-0.8 Ga) were characterized by an overall low-oxygen background punctuated by pulsed oxygenation events. This viewpoint, however, is primarily based on the redox studies from the first half of the "Boring Billion". Therefore, it remains unclear whether this state continued into the second half. To address this issue, carbonate rocks from the ca. 1.25-1.22 Ga Taizi and Yemahe formations in the Shennongjia area, Yangtze Block, South China, were analyzed using integrated methods. The carbonate rocks in the upper Taizi Formation display persistent and significant negative Ce anomalies (0.50 +/- 0.05, n = 46) and relatively high I/(Ca + Mg) ratios (up to 1.28 mu mol/mol), whereas those from the Yemahe Formation show no negative Ce anomalies (0.99 +/- 0.21, n = 39) and low I/(Ca + Mg) ratios (0.03 +/- 0.04 mu mol/mol, n = 86). These data suggest the occurrence of a significant pulsed oxygenation event in shallow seawater during the deposition of the upper Taizi Formation. A model calculation shows that the shallow seawater oxygen concentrations may have reached up to 41 mu M, accompanied with a rise in atmospheric oxygen levels to 12% PAL (present atmospheric level). In contrast, the reconstructed seawater delta 98Mo value is +1.15 parts per thousand for this interval, lower than that of the modern seawater but similar to those of most mid-Proterozoic values, indicating the global seafloor largely remained anoxic. These findings indicate that the ocean redox state in the second half of the "Boring Billion" was more dynamic than previously thought
Terrestrial ecosystem response to Early Cretaceous global environmental change: A calibrated, high-resolution Aptian record from Northeast China
No full textExtensive studies of Aptian oceanic anoxic events and carbon cycle perturbations have significantly advanced our understanding of marine responses to global climate change. However, further exploration of possible volcanism-climate-environment linkages is hindered by the scarcity of continuous, well-documented terrestrial records. In an attempt to address this gap, the Yanshan Scientific Drilling Project extracted a 1497.5 m core from the shale-dominated, lacustrine, Jiufotang Formation in the Kazuo Basin of Northeast China. High-precision U-Pb geochronology of two interlayered tuffs yielded depositional ages of 121.05 +/- 0.32 Ma and 117.359 +/- 0.031 Ma, and a Bayesian age-depth model for the lower half of the formation. An astrochronological model based on delta 13Corg and major element chemostratigraphy has suggested a duration of 9.03-9.14 Ma for the entire core, from 121.05 to 121.30 to 111.91-112.20 Ma. A 75.2 m core interval with unequivocal correlation to the oceanic anoxic event (OAE) 1a was identified by carbon isotope stratigraphy, which has a calibrated onset at 120.2 Ma and a total duration of ca. 450 kyr. Our results highlight the potential of lacustrine strata in recording at highresolution the marine-correlated carbon cycle changes and in deciphering the drivers and mechanisms of climate change across the marine and terrestrial realms