Rapid determination of germanium in lignite coal and coal-related solid byproducts by graphite furnace digestion inductively coupled plasma emission spectroscopy.

This study developed a rapid and efficient graphite furnace digestion combined with inductively coupled plasma emission spectrometry (ICP-OES) method, enabling precise quantification of germanium (Ge) in coal and various coal-derived metallurgical byproducts across a broad concentration level (∼ppm-n%). The graphite furnace digestion conditions were examined intensively as a function of the acid amounts of HNO3 and HF (5-10 mL), temperature (80-180 °C), time (1-5 h), and acid drive methods (H3BO3 neutralization versus heating). Coal references including SARM 19, SARM 20, NIST SRM 1632e, and fly ash standard NIST SRM 2689 were tested. The optimum recovery of germanium was obtained when the HNO3 dosage, HF dosage, solid sample mass, temperature, and duration time were 10 mL, 5 mL, 0.1 g, 80 °C and 1 h. Agreement of 95.15-96.54 % between the measured and certified value was obtained under the optimum conditions. The spiked recovery was 103.23-103.54 %, indicating the matrix-analytes interactions were negligible. Boric acid neutralization reduced the recovery rates to 47.2-49.3 % and was not be appropriate for driving HF. The optimal spectral line for determining Ge is at a wavelength of 265.117 nm, at which the limit of detect and the limit of quantification were 0.46 µg L-1 and 1.53 µg L-1, respectively. The applicability of the method was validated by quantifying Ge in Ge-rich lignite, fly ashes (FA), and chlorinated distillation residue (CR) samples. The concentration of Ge in coals was 44.75-225.41 µg g-1, the content in FA was 0.68%-2.3 %, and the content in CR was 0.18 %, with the uncertainty of the method obtained being less than 0.5 %. X-ray fluorescence spectrometer (XRF) was used to verify the results. The difference between XRF data and ICP-OES data was less than 5 %, confirming the accuracy and reproductivity of the analytical method.

Simulating short-term light responses of photosynthesis and water use efficiency in sweet sorghum under varying temperature and CO2 conditions.

Climate change, characterized by rising atmospheric CO2 levels and temperatures, poses significant challenges to global crop production. Sweet sorghum, a prominent C4 cereal extensively grown in arid areas, emerges as a promising candidate for sustainable bioenergy production. This study investigated the responses of photosynthesis and leaf-scale water use efficiency (WUE) to varying light intensity (I) in sweet sorghum under different temperature and CO2 conditions. Comparative analyses were conducted between the A n-I, g s-I, T r-I, WUEi-I, and WUEinst-I models proposed by Ye et al. and the widely utilized the non-rectangular hyperbolic (NRH) model for fitting light response curves. The Ye's models effectively replicated the light response curves of sweet sorghum, accurately capturing the diminishing intrinsic WUE (WUEi) and instantaneous WUE (WUEinst) trends with increasing I. The fitted maximum values of A n, g s, T r, WUEi, and WUEinst and their saturation light intensities closely matched observations, unlike the NRH model. Despite the NRH model demonstrating high R 2 values for A n-I, g s-I, and T r-I modelling, it returned the maximum values significantly deviating from observed values and failed to generate saturation light intensities. It also inadequately represented WUE responses to I, overestimating WUE. Across different leaf temperatures, A n, g s, and T r of sweet sorghum displayed comparable light response patterns. Elevated temperatures increased maximum A n, g s, and T r but consistently declined maximum WUEi and WUEinst. However, WUEinst declined more sharply due to the disproportionate transpiration increase over carbon assimilation. Critically, sweet sorghum A n saturated at current atmospheric CO2 levels, with no significant gains under 550 µmol mol-1. Instead, stomatal closure enhanced WUE under elevated CO2 by coordinated g s and T r reductions rather than improved carbon assimilation. Nonetheless, this response diminished under simultaneously high temperature, suggesting intricate interplay between CO2 and temperature in modulating plant responses. These findings provide valuable insights into photosynthetic dynamics of sweet sorghum, aiding predictions of yield and optimization of cultivation practices. Moreover, our methodology serves as a valuable reference for evaluating leaf photosynthesis and WUE dynamics in diverse plant species.

Addressing the long-standing limitations of double exponential and non-rectangular hyperbolic models in quantifying light-response of electron transport rates in different photosynthetic organisms under various conditions.

The models used to describe the light response of electron transport rate in photosynthesis play a crucial role in determining two key parameters i.e., the maximum electron transport rate (J max) and the saturation light intensity (I sat). However, not all models accurately fit J-I curves, and determine the values of J max and I sat. Here, three models, namely the double exponential (DE) model, the non-rectangular hyperbolic (NRH) model, and a mechanistic model developed by one of the coauthors (Z-P Ye) and his coworkers (referred to as the mechanistic model), were compared in terms of their ability to fit J-I curves and estimate J max and I sat. Here, we apply these three models to a series of previously collected Chl a fluorescence data from seven photosynthetic organisms, grown under different conditions. Our results show that the mechanistic model performed well in describing the J-I curves, regardless of whether photoinhibition/dynamic down-regulation of photosystem II (PSII) occurs. Moreover, both J max and I sat estimated by this model are in very good agreement with the measured data. On the contrary, although the DE model simulates quite well the J-I curve for the species studied, it significantly overestimates both the J max of Amaranthus hypochondriacus and the I sat of Microcystis aeruginosa grown under NH4 +-N supply. More importantly, the light intensity required to achieve the potential maximum of J (J s) estimated by this model exceeds the unexpected high value of 105 µmol photons m-2 s-1 for Triticum aestivum and A. hypochondriacus. The NRH model fails to characterize the J-I curves with dynamic down-regulation/photoinhibition for Abies alba, Oryza sativa and M. aeruginosa. In addition, this model also significantly overestimates the values of J max for T. aestivum at 21% O2 and A. hypochondriacus grown under normal condition, and significantly underestimates the values of J max for M. aeruginosa grown under NO3 -N supply. Our study provides evidence that the 'mechanistic model' is much more suitable than both the DE and NRH models in fitting the J-I curves and in estimating the photosynthetic parameters. This is a powerful tool for studying light harvesting properties and the dynamic down-regulation of PSII/photoinhibition.

Long-term tadalafil once daily in Chinese men with erectile dysfunction: a 2-year final analysis of a post-marketing, multicenter, randomized, open-label trial.

The long-term safety and effectiveness of once-daily tadalafil is crucial, but limited data are available in Chinese patients with erectile dysfunction (ED). In this post-marketing, multicenter, randomized, open-label trial with 2-year follow-up, 635 ED cases were randomized to receive daily oral tadalafil 2.5 mg or 5 mg for 3 months, of whom 580 continued once-daily tadalafil 5 mg for 21 months. Treatment-emergent adverse events in the 12-month and 24-month period were similar, with the most common being viral upper respiratory tract infection, upper respiratory tract infection, and headache. Significant improvement from baseline in the International Index of Erectile Function-Erectile Function (IIEF-EF) score was detected at month 12 (least squares mean [LSM] change: 7.9, 95% confidence interval [CI]: 7.5-8.4, P < 0.001) and was maintained to month 24 (LSM change: 8.6, 95% CI: 8.1-9.0, P < 0.001). The proportions of patients regaining normal erectile function (IIEF-EF score ≥26) were 43.7% and 48.0% at months 12 and 24, respectively. Global Assessment Questionnaire results showed improved erection function in 97.5% of patients and improved ability to engage in sexual activity in 95.9% of patients at month 12; these values were 96.1% and 95.0% at month 24, respectively. The quality of sexual life score based on the Sexual Life Quality Questionnaire (SLQQ) was increased by 52.2% at month 12 and by 55.3% at month 24 (both P < 0.001). The treatment satisfaction score determined by SLQQ (mean ± standard deviation) was 62.4 ± 21.0 at month 12 versus 65.9 ± 20.2 at month 24. Two-year daily application of tadalafil 5 mg in Chinese men with ED showed a favorable safety profile and durable improvement in sexual performance and satisfaction.

Simultaneously tuning the luminescent color and realizing an optical temperature sensor by negative thermal expansion in Sc2(WO4)3:Tb/Eu phosphors.

At present, many researchers are focusing on trivalent lanthanide (Ln3+)-doped thermally enhanced upconversion luminescent (UCL) materials with negative thermal expansion (NTE) properties. However, selective anti-thermal quenching downshifting emissions of the activator and thermal quenching of the sensitizer in a phosphor with NTE properties are not implemented. Herein, Tb3+/Eu3+ co-doped Sc2(WO4)3 phosphors synthesized by the solid-state method are explored in selectively enhanced red emission (Eu3+:5D0 → 7F2) due to the energy-transfer efficiency from Tb3+ to Eu3+ and the promoted radiative transition probability. The selective thermally quenched green emission (Tb3+:5D4 → 7F5) is owing to the change of energy transfer from Tb3+ to Eu3+ as the temperature increased. Moreover, under ultraviolet 365 nm excitation, the thermally stimulated color emission tuned from yellow to red with the increase in temperature. Based on the radically different thermal response downshifting the luminescence of the activator and sensitizer, the luminescence intensity ratio (LIR) of non-thermally coupled levels (NTCLs) for 5D0 (Eu3+) and 5D4 (Tb3+) is adopted for optical temperature sensing. The optimal relative sensitivity of temperature sensing in the Sc2(WO4)3:25%Tb3+/3%Eu3+ sample could reach 2.94% K-1 at 347 K. All these indicate that this Sc2(WO4)3:Tb3+/Eu3+ material is a promising candidate for high-sensitivity optical temperature sensing.

Investigation on absorption cross-section of photosynthetic pigment molecules based on a mechanistic model of the photosynthetic electron flow-light response in C3, C4 species and cyanobacteria grown under various conditions.

Investigation on intrinsic properties of photosynthetic pigment molecules participating in solar energy absorption and excitation, especially their eigen-absorption cross-section (σ ik) and effective absorption cross-section (σ ' ik), is important to understand photosynthesis. Here, we present the development and application of a new method to determine these parameters, based on a mechanistic model of the photosynthetic electron flow-light response. The analysis with our method of a series of previously collected chlorophyll a fluorescence data shows that the absorption cross-section of photosynthetic pigment molecules has different values of approximately 10-21 m2, for several photosynthetic organisms grown under various conditions: (1) the conifer Abies alba Mill., grown under high light or low light; (2) Taxus baccata L., grown under fertilization or non-fertilization conditions; (3) Glycine max L. (Merr.), grown under a CO2 concentration of 400 or 600 µmol CO2 mol-1 in a leaf chamber under shaded conditions; (4) Zea mays L., at temperatures of 30°C or 35°C in a leaf chamber; (5) Osmanthus fragrans Loureiro, with shaded-leaf or sun-leaf; and (6) the cyanobacterium Microcystis aeruginosa FACHB905, grown under two different nitrogen supplies. Our results show that σ ik has the same order of magnitude (approximately 10-21 m2), and σ ' ik for these species decreases with increasing light intensity, demonstrating the operation of a key regulatory mechanism to reduce solar absorption and avoid high light damage. Moreover, compared with other approaches, both σ ik and σ ' ik can be more easily estimated by our method, even under various growth conditions (e.g., different light environment; different CO2, NO2, O2, and O3 concentrations; air temperatures; or water stress), regardless of the type of the sample (e.g., dilute or concentrated cell suspensions or leaves). Our results also show that CO2 concentration and temperature have little effect on σ ik values for G. max and Z. mays. Consequently, our approach provides a powerful tool to investigate light energy absorption of photosynthetic pigment molecules and gives us new information on how plants and cyanobacteria modify their light-harvesting properties under different stress conditions.

A review on light response model of photosynthesis under different environmental conditions.

Light response curve of photosynthesis (An-I curve) is a useful modeling tool to investigate how photosynthesis reacts with different abiotic factors, which would help quantify the response of photosynthetic rate to photosynthetically active radiation. Based on the mathematical characteristics of photosynthesis An-I models, we reviewed the advantages of using these model in practice and the potential caveats. We proposed the development of new mechanistic photosynthesis An-I models based on the primary light response and discussed its advantages in the field of plant ecology and physiology. Photosynthesis has three main steps, including the primary reaction, the assimilatory power forms, and the carbon assimilation. Changes in each step could directly affect the photochemical efficiency and carbon assimilation in photosynthesis. The primary reaction consists of a series of physical processes that are related to light energy absorption and utilization, including the absorption of light energy, the change of quantum state, and the transfer and de-excitation of exciton resonance of light-trapping pigment molecules. How-ever, the empirical photosynthesis An-I models can not explain some scenarios. For example, the non-photochemical quenching in plants increases with increasing light intensity in a non-linear manner. Further, the life-time of singlet chlorophyll molecules can be extended when plant light-harvesting pigment molecules absorb excessive light energy but would not be immediately used for the photochemical reaction. Meanwhile, the parameters obtained by fitting the mechanistic An-I curve model can not only reflect the primary photochemical reaction characteristics of plants, but also describe the physical characteristics of plant light harvesting pigment molecules, such as the number of light harvesting pigment molecules in the excited state (Nk) and effective light energy absorption cross-section (σik'). This can be used to further investigate the physical characteristics of light harvesting pigment molecules, including the light-response of Nk and σik' and the average life time of light harvesting pigment molecules in the lowest exciting state (τmin). In addition, it would be necessary to determine how to incorporate abiotic factors, such as temperature and CO2 concentration, into the mechanistic An-I curve model, as well as to determine the association between the abiotic factors and light harvesting pigment molecules, such as Nk, σik', and τmin.

Simultaneous Thermal Enhancement of Upconversion and Downshifting Luminescence by Negative Thermal Expansion in Nonhygroscopic ZrSc(WO4)2PO4:Yb/Er Phosphors.

Thermal quenching (TQ) is still a critical challenge for lanthanide (Ln3+)-doped luminescent materials. Herein, we report the novel negative thermal expansion nonhygroscopic phosphor ZrSc(WO4)2PO4:Yb3+/Er3+. Upon excitation with a 980 nm laser, a simultaneous thermal enhancement is realized on upconversion (UC) and downshifting (DS) emissions from room temperature to 573 K. In situ temperature-dependent X-ray diffraction and photoluminescence dynamics are used to reveal the luminescence mechanism in detail. The coexistence of the high energy transfer efficiency and the promoted radiative transition probability can be responsible for the thermally enhanced luminescence. On the basis of the luminescence intensity ratio of thermally coupled energy levels 2H11/2 and 4S3/2 at different temperatures, the relative and absolute sensitivities of the targeted samples reach 1.10% K-1 and 1.21% K-1, respectively, and the low-temperature uncertainty is approximately 0.1-0.4 K on the whole temperature with a high repeatability (98%). Our findings highlight a general approach for designing a hygro-stable, thermostable, and highly efficient Ln3+-doped phosphor with UC and DS luminescence.

Fine chemical speciation and environmental impact capacity of trace elements with different enrichment levels in coal.

Enriched trace elements in coal are considered to have a high environmental impact, but the extent of the influence of the enrichment level is unclear. To study the chemical speciation and environmental behavior of trace elements in coal at different enrichment levels, representative coal samples from multiple provinces in China were collected, including bituminous coal I-L2 from Inner Mongolia with high concentrations of Be, Y, Zn, Tl, U, Er, and Yb, and 72-9 coal from Anhui enriched with Cu, Cd, Pb, V, and Zn. The chemical speciation of trace elements in coal was analyzed using a variety of techniques, including X-ray Photoelectron Spectroscopy (XPS), Near Edge X-ray Absorption Fine Structure (NEXAFS), and sequential chemical extraction procedures. Cluster analysis was used for grouping the coal samples based on the enrichment coefficients of trace elements. Coal samples with similar genesis and in closer regions were more likely to be grouped. Metal carbonates and metal sulfate were observed in coals through XPS analysis. The main C species in coal were identified as phenolic C, carboxylic C, unsaturated C, and O-alkyl C/carbonyl C through NEXAFS. The amplitude variation of peaks for the fly ash was smaller than that for the feed coal, which showed that the structure of carbon became homogeneous after high-temperature combustion. It was difficult to identify the chemical speciation difference of trace elements with different enrichment degrees in coals through XPS and NEXAFS, but the results of the sequential chemical extraction could compensate. Several enriched trace elements in coal were relatively high in the chemical fractions (exchangeable, carbonates and monosulfides associated, or FeMn oxide bound) that were easy to extract and relatively low in the less insoluble chemical fractions (organic matter-bound, disulfides associated, or silicates associated), indicating that enriched trace elements in coal had higher environmental impact capacity.

Simplified stepwise anatomical ablation strategy for mitral isthmus: efficacy, efficiency, safety, and outcome.

AIMS: Bidirectional and durable block of mitral isthmus (MI) is essential for catheter ablation of persistent atrial fibrillation (PeAF) and perimitral flutter (PMF), but it remains a challenge. The aim of this study was to create a simple anatomical ablation strategy with minimal fluoroscopy that would yield a high success rate for MI block. METHODS AND RESULTS: Patients with PeAF or PMF were included. Mitral isthmus was ablated in a stepwise strategy. In Step 1, endocardial MI linear ablation was performed; in Step 2, ablation was targeted to the posterolateral portion of the left atrium along the MI line; in Step 3, epicardial ablation within the coronary sinus (CS) was performed across the MI line to the ostium of the vein of Marshall (VOM) or performed within the VOM if available; in Step 4, the catheter was rotated and ablated in the CS to isolate the CS; and in Step 5, the early activation site with complex component potential above the MI line during distal CS pacing was considered as the ablation target. All patients were followed up. A total of 178 (17 patients with mechanical prosthetic mitral valve) were included. One hundred and sixty-six patients achieved a confirmed MI bidirectional conduction block (93%). One patient had cardiac tamponade. Four patients showed re-conduction across the MI line during a repeated ablation. In the latest follow-up [12 (7, 16) months], 161 of 178 (90%) patients maintained their sinus rhythm. CONCLUSION: A simple stepwise anatomical ablation strategy for MI shows a high success rate with low fluoroscopy exposure.

Chromium in Chinese coals: geochemistry and environmental impacts associated with coal-fired power plants.

Chromium (Cr), one of the prime hazardous trace elements in coals, may engender adverse effects on eco-environment and threaten human health during utilization of coal. Based on the samples obtained in our laboratory and published literature, the abundance and modes of occurrence of Cr in Chinese coals, and the environmental impacts associated with coal-fired power plants (CFPPs) were elucidated in this study. With a total of 1397 sets of data, the mean concentration of Cr in Chinese coals was calculated as 21.33 µg/g by the "reserve-concentration" weighted calculation method. Spatially, the average Cr contents increased gradually from North China to South China. Temporally, coals from T3, E-N and P2 were relatively enriched in Cr compared to the other geological time. The Cr concentration in coal varied with different coal ranks. The geological factors accounted for Cr enrichment in coals could be divided into the primary, secondary and epigenetic processes. Higher percentages of organically Cr occurred in low-rank coals, while inorganically associated Cr was mainly found in clay minerals. After coal combustion, most of Cr was enriched in solid wastes (e.g., fly ash and bottom ash). The leaching of Cr from solid wastes in the rainy season (especially acid rain) needs to be a concern for CFPPs. It was estimated that the atmospheric emission of Cr from CFPPs increased annually from 2015 to 2019 and reached approximately 159 tons in 2019.

T cell exhaustion assessment algorism in tumor microenvironment predicted clinical outcomes and immunotherapy effects in glioma.

Despite the recent increase in the use of immune checkpoint blockade (ICB), no ICB medications have been approved or are undergoing large-scale clinical trials for glioma. T cells, the main mediators of adaptive immunity, are important components of the tumor immune microenvironment. Depletion of T cells in tumors plays a key role in assessing the sensitivity of patients to immunotherapy. In this study, the bioinformatics approach was applied to construct T cell depletion-related risk assessment to investigate the impact of T cell depletion on prognosis and ICB response in glioma patients. The Cancer Genome Atlas (TCGA) and GSE108474 glioma cohorts and IMvigor210 immunotherapy datasets were collected, including complete mRNA expression profiles and clinical information. We used cell lines to verify the gene expression and the R 3.6.3 tool and GraphPad for bioinformatics analysis and mapping. T cell depletion in glioma patients displayed significant heterogeneity. The T cell depletion-related prognostic model was developed based on seven prognostic genes (HSPB1, HOXD10, HOXA5, SEC61G, H19, ANXA2P2, HOXC10) in glioma. The overall survival of patients with a high TEXScore was significantly lower than that of patients with a low TEXScore. In addition, high TEXScore scores were followed by intense immune responses and a more complex tumor immune microenvironment. The "hot tumors" were predominantly enriched in the high-risk group, which patients expressed high levels of suppressive immune checkpoints, such as PD1, PD-L1, and TIM3. However, patients with a low TEXScore had a more significant clinical response to immunotherapy. In addition, HSPB1 expression was higher in the U251 cells than in the normal HEB cells. In conclusion, the TEXScore related to T cell exhaustion combined with other pathological profiles can effectively assess the clinical status of glioma patients. The TEXScore constructed in this study enables the effective assessment of the immunotherapy response of glioma patients and provides therapeutic possibilities.

Impact of ultra-low emission retrofitting on partitioning and emission behavior of chromium in a Chinese coal-fired power plant.

Due to its low vapor pressure, chromium (Cr) mostly emitted as fly ash particles (especially PM2.5) into environment in coal-fired power plants (CFPPs). The ultra-low emission (ULE) control technologies used in current CFPPs may be beneficial to reducing both the regular pollutants and hazardous trace elements (e.g., Cr), but the insight into the removal efficiency of Cr by different upgrading air pollution cleaning devices (APCDs) and the environmental stability of the Cr-bearing wastes produced from those APCDs in the ULE CFPPs has rarely reported. This study investigated and compared the distribution and emission characteristics of Cr in a Chinese CFPP before and after ULE, and the leaching behavior of Cr after ULE retrofitting in combustion byproducts was also revealed. The results showed that Cr was primarily captured in bottom and fly ashes (80.85%), followed by gypsum (0.02%) and sludge from wet electrostatic precipitator (WESP) (4.52 × 10-4%), with only 3.02 × 10-8% emitted into the atmosphere. Additional WESP had a large removal efficiency of Cr with the value of 92.04%, and the overall Cr removal efficiency of selective catalytic reduction (SCR) equipment, electrostatic precipitator (ESP), wet flue gas desulphurization (WFGD) system, and WESP equipped after ULE retrofitting was 99.99%. Notably, although the mass percentage of Cr in WESP sludge was negligible, the concentration of Cr in WESP sludge was 324.04 mg/kg. The leaching concentrations of Cr in combustion byproducts were in the descending order: fly ash > WESP sludge > bottom ash > gypsum. The atmospheric emission factor of Cr in the studied power plant was 1.08 mg/t coal, which was significantly lower than those of the CFPPs before ULE retrofitting. Therefore, the ULE retrofitting for CFPP was beneficial to reduce Cr emissions. More attention should be paid to the subsequent processing problem of solid combustion byproducts, especially the WESP sludge.

Thermally boosted upconversion and downshifting luminescence in Sc2(MoO4)3:Yb/Er with two-dimensional negative thermal expansion.

Rare earth (RE3+)-doped phosphors generally suffer from thermal quenching, in which their photoluminescence (PL) intensities decrease at high temperatures. Herein, we report a class of unique two-dimensional negative-thermal-expansion phosphor of Sc2(MoO4)3:Yb/Er. By virtue of the reduced distances between sensitizers and emitters as well as confined energy migration with increasing the temperature, a 45-fold enhancement of green upconversion (UC) luminescence and a 450-fold enhancement of near-infrared downshifting (DS) luminescence of Er3+ are achieved upon raising the temperature from 298 to 773 K. The thermally boosted UC and DS luminescence mechanism is systematically investigated through in situ temperature-dependent Raman spectroscopy, synchrotron X-ray diffraction and PL dynamics. Moreover, the luminescence lifetime of 4I13/2 of Er3+ in Sc2(MoO4)3:Yb/Er displays a strong temperature dependence, enabling luminescence thermometry with the highest relative sensitivity of 12.3%/K at 298 K and low temperature uncertainty of 0.11 K at 623 K. These findings may gain a vital insight into the design of negative-thermal-expansion RE3+-doped phosphors for versatile applications.

The intriguing roles of Siglec family members in the tumor microenvironment.

Sialic acid-binding receptors are expressed on the surfaces of a variety of immune cells and have complex and diverse immunoregulatory functions in health and diseases. Recent studies have shown that Siglecs could play diverse immune and nonimmune regulatory roles in the tumor microenvironment (TME) and participate in tumor progression through various mechanisms, such as regulating tumor growth and metastasis, mediating the inflammatory response, and promoting tumor immune escape, thereby affecting the prognoses and outcomes of patients. However, depending on the cell type in which they are expressed, each Siglec member binds to corresponding ligands in the microenvironment milieu to drive diverse cell physiological and pathological processes in tumors. Therefore, we herein summarize the expression spectra and functions of the Siglec family in human diseases, particularly cancer, and highlight the possibility of therapeutic interventions targeting the TME in the future.

Fine particulate-bound arsenic and selenium from coal-fired power plants: Formation, removal and bioaccessibility.

The arsenic (As) and selenium (Se) in fine particulate matter (PM10) have attracted increasing attentions due to their health effects. However, the emission control of fine particulate-bound arsenic and selenium (fine particulate-bound As/Se) from coal-fired power plants still faces various challenges. Understanding the formation and characteristics of fine particulate-bound As/Se is crucial for developing specific control technologies. This study clarifies the formation mechanism, removal characteristics, and inhalation bioaccessibility of fine particulate-bound As/Se from industrial coal-fired power plants through methods including aerosol generation, As/Se speciation determination, and in vitro bioaccessibility testing. The findings demonstrated that PM1 from pulverized coal-fired (PC) boilers was enriched with As/Se in terms of concentration and mass distribution. Instead, As/Se was mainly distributed in PM2.5-10 from circulating fluidized bed (CFB) boilers. Limestone injection in CFB boilers promoted As/Se enrichment in coarse PM. Fine particulate-bound As was mainly formed by chemical adsorption of As vapors by Ca-minerals, while the formation of fine particulate-bound Se was closely related to active Ca-minerals and Fe-minerals. Furthermore, Ca-bound As was easy to remove by electrostatic precipitator (ESP) and the removal of physically adsorbed SeO2(s) was difficult, which was caused by the specific resistivity of different mineral components. Importantly, finer particulate-bound As/Se posed higher inhalation bioaccessibility, following the order of PM1 ≥ PM1-2.5 > PM2.5-10. In particular, Ca-bound Se in fine PM owned high bioaccessibility. Based on these findings, measures were proposed to suppress the formation of fine particulate-bound As/Se in the furnace and/or strengthen its removal in the post-combustion stage.

Condensation and adsorption characteristics of gaseous selenium on coal-fired fly ash at low temperatures.

Gaseous selenium is of high saturated vapor pressure, making its retention in solid phases quite difficult during coal combustion. The selenium transformation from gaseous form into solid phases at low temperatures can be essential to control selenium emission. To understand the migration of SeO2 (g) on ash particles in the low-temperature zone, this study investigated the speciation of selenium in fly ash and simulated the physical retention of SeO2 (g) on fly ash. The results demonstrated that there was a large proportion of physically-bound Se in the fly ash of pulverized-coal-fired boiler (22.62 %-58.03%), while the content of physically-bound Se in fly ash of circulated fluidized-bed boiler was lower (∼6%). The physically-bound Se was formed through selenium condensation and physical adsorption. The decrease of temperature or the increase of cooling rate could promote the transformation of gaseous selenium to solid phase and the presence of HCl might suppress SeO2 transformation into Se in the condensation process. Meanwhile the compositions of fly ash had a great influence on the selenium adsorption process. Among typical coal-fired ash components, mullite showed the best performance in the selenium capture in the temperature range of 90-200 °C, contributing to the high content of physically-adsorbed selenium in PC fly ash. These findings provided new ideas for improving the removal rate of volatile selenium.