Ordered heterogeneity of molecular photosensitizer toward enhanced photocatalysis.

SignificanceThe photosensitizer is one of the important components in the photocatalytic system. Molecular photosensitizers have well-defined structures, which is beneficial in revealing the catalysis mechanism and helpful for further structural design and performance optimization. However, separation and recycling of the molecular photosensitizers is a great problem. Loading them into/on two/three-dimensional supports through covalent bonds, electrostatic interactions, and supramolecular interactions is a method that enhances their separation and recycling capability. Nonetheless, the structures of the resulting composites are unclear. Thus, the development of highly crystalline heterogeneity methods for molecular photosensitizers, albeit greatly challenging, is meaningful and desirable in photocatalysis, through which heterogeneous photosensitizers with well-defined structures, definite catalysis mechanisms, and good catalytic performance would be expected.

Super Enhancer-Associated Circular RNA-CircKrt4 Regulates Hypoxic Pulmonary Artery Endothelial Cell Dysfunction in Mice.

BACKGROUND: Circular RNAs (circRNAs) have been implicated in pulmonary hypertension progression through largely unknown mechanisms. Pulmonary artery endothelial cell (PAEC) dysfunction is a hallmark in the pathogenesis of pulmonary hypertension. However, the specific role of circular RNAs in PAEC injury caused by hypoxia remains unclear. METHODS: In this study, using the Western blotting, RNA pull down, Dual-luciferase reporter assay, immunohistochemistry, and immunofluorescence, we identified a novel circular RNA derived from alternative splicing of the keratin 4 gene (circKrt4). RESULTS: CircKrt4 was upregulated in lung tissues and plasma and specifically in PAECs under hypoxic conditions. In the nucleus, circKrt4 induces endothelial-to-mesenchymal transition by interacting with the Pura (transcriptional activator protein Pur-alpha) to promote N-cadherin gene activation. In the cytoplasm, increased circKrt4 leads to mitochondrial dysfunction by inhibiting cytoplasmic-mitochondrial shuttling of mitochondrial-bound Glpk (glycerol kinase). Intriguingly, circKrt4 was identified as a super enhancer-associated circular RNA that is transcriptionally activated by a transcription factor, CEBPA (CCAAT enhancer binding protein alpha). Furthermore, RBM25 (RNA-binding-motif protein 25) was found to regulate circKrt4 cyclization by increase the back-splicing of Krt4 gene. CONCLUSIONS: These findings demonstrate that a super enhancer-associated circular RNA-circKrt4 modulates PAEC injury to promote pulmonary hypertension by targeting Pura and Glpk.

Boosting CO2 Photoreduction to Formate or CO with High Selectivity over a Covalent Organic Framework Covalently Anchored on Graphene Oxide.

Covalent organic frameworks (COFs) have been widely studied in photocatalytic CO2 reduction reaction (CO2 RR). However, pristine COFs usually exhibit low catalytic efficiency owing to the fast recombination of photogenerated electrons and holes. In this study, we fabricated a stable COF-based composite (GO-COF-366-Co) by covalently anchoring COF-366-Co on the surface of graphene oxide (GO) for the photocatalytic CO2 reduction. Interestingly, in absolute acetonitrile (CH3 CN), GO-COF-366-Co shows a high selectivity of 94.4 % for the photoreduction of CO2 to formate, with a formate yield of 15.8 mmol/g, which is approximately four times higher than that using the pristine COF-366-Co. By contrast, in CH3 CN/H2 O (v : v=4 : 1), the main product for the photocatalytic CO2 reduction over GO-COF-366-Co is CO (96.1 %), with a CO yield as high as 52.2 mmol/g, which is also approximately four times higher than that using the pristine COF-366-Co. Photoelectrochemical experiments demonstrate the covalent bonding of COF-366-Co and GO to form the GO-COF-366-Co composite facilitates charge separation and transfer significantly, thereby accounting for the enhanced catalytic activity. In addition, theoretical calculations and in situ Fourier transform infrared spectroscopy reveal H2 O can stabilize the *COOH intermediate to further form a *CO intermediate via O-H(aq)⋅⋅⋅O(*COOH) hydrogen bonding, thus explaining the regulated photocatalytic performance.

Water-Etched Approach to Hierarchically Porous Metal-Organic Frameworks with High Stability.

The development of hierarchically porous metal-organic frameworks (MOFs) with high stability is desirable to expand their applications but remains challenging. Herein, an anionic sodalite-type microporous MOF (Yb-TTCA; TTCA3- = triphenylene-2,6,10-tricarboxylate) was synthesized, which shows outstanding catalytic activities for the cycloaddition of CO2 into cyclic carbonates. Moreover, the microporous Yb-TTCA can be transformed into a hierarchical micro- and mesoporous Yb-TTCA by water treatment with the mesopore sizes of 2 to 12 nm. The hierarchically porous Yb-TTCA (HP-Yb-TTCA) not only exhibits a high thermal stability up to 500 °C but also shows a high chemical stability in aqueous solutions with pH values ranging from 2 to 12. In addition, the HP-Yb-TTCA displays enhanced performance for the removal of organic dyes in comparison with microporous Yb-TTCA. This work provides a facile way to construct hierarchically porous MOF materials.

Hg0 Conversion over Sulfureted HPMo/γ-Fe2O3 with HCl at Low Temperatures: Mechanism, Kinetics, and Application in Hg0 Removal from Coal-Fired Flue Gas.

Recently, sulfureted metal oxides have been developed for the catalytic oxidation of Hg0 to HgCl2 using HCl as an oxidant at low temperatures, and they exhibit excellent Hg0 removal performance. Owing to the lack of reaction mechanisms and kinetics, further improvement in their performance for Hg0 conversion is extremely restricted. In this study, the reaction mechanism of Hg0 conversion over sulfureted HPMo/γ-Fe2O3 with HCl at low temperatures was investigated using Hg balance analysis and transient reaction. The chemical adsorption of Hg0 as HgS and the catalytic oxidation of Hg0 to HgCl2 both contributed to Hg0 conversion over sulfureted HPMo/γ-Fe2O3. Meanwhile, the formed HgCl2 can adsorb onto sulfureted HPMo/γ-Fe2O3. Then, the kinetics of Hg0 conversion, Hgt adsorption, and HgCl2 desorption were developed, and the kinetic parameters were gained by fitting the Hg balance curves. Subsequently, the inhibition mechanism of H2O and SO2 on Hg0 conversion over sulfureted HPMo/γ-Fe2O3 was determined by comparing the kinetic parameters. The kinetic model suggested that both HgCl2 resulting from Hg0 oxidation and unoxidized Hg0 can be completely adsorbed on sulfureted HPMo/γ-Fe2O3 with a moderate mass hourly space velocity. Therefore, sulfureted HPMo/γ-Fe2O3 can be developed as a reproducible sorbent for recovering Hg0 emitted from coal-fired power plants.

Highly efficient Cr (VI) removal from electroplating wastewater by regenerable copper sulfides: Mechanism and magical induction effect for Cr resource recovery.

The current sorbents used to remove Cr (VI) from electroplating wastewater are faced with some challenges including the difficulty in separating, regenerating, and safely disposing of adsorbed Cr species. To address these challenges, CuSx/TiO2 was developed to recover Cr (VI) from electroplating wastewater. CuSx/TiO2 had superior performance in removing Cr (VI), with the rate and capacity of approximately 9.36 mg g-1 h-1 and 68.8 mg g-1 at initial pH 4.0, respectively. Additionally, Cu2+ released from CuSx/TiO2 during Cr (VI) removal would come back to its external surface as the Cu(OH)2 precipitate at initial pH 4.0, which helped to prevent the generation of secondary pollution. The Cu(OH)2 precipitate would be decomposed into CuOx after calcination, which would then be transformed back into CuSx by re-sulfuration for regeneration. Hence, CuSx showed a magical induction effect on Cr (VI) recovery, and Cr (VI) from electroplating wastewater might be gradually enriched as Cr2O3 in the sandwich between CuSx and TiO2 through multiple regenerations and removals, which could be considered as a chromium ore resource for industrial applications when the amount of enriched Cr2O3 reached more than 30 wt%. Overall, CuSx/TiO2 showed great potential as a promising sorbent for Cr (VI) removal from electroplating wastewater.

Paeonol represses A549 cell glycolytic reprogramming and proliferation by decreasing m6A modification of Acyl-CoA dehydrogenase.

Aberrant glycolytic reprogramming is involved in lung cancer progression by promoting the proliferation of non-small cell lung cancer cells. Paeonol, as a traditional Chinese medicine, plays a critical role in multiple cancer cell proliferation and inflammation. Acyl-CoA dehydrogenase (ACADM) is involved in the development of metabolic diseases. N6-methyladenosine (m6A) modification is important for the regulation of messenger RNA stability, splicing, and translation. Here, we investigated whether paeonol regulates the proliferation and glycolytic reprogramming via ACADM with m6A modification in A549 cells (human non-small cell lung cancer cells). Cell counting kit 8, 5-Bromo-2-deoxyuridine, 5-ethynyl-2'-deoxyuridine (EdU) incorporation, flow cytometry analysis, western blotting and seahorse XFe24 extracellular flux analyzer assays showed that paeonol had a significant inhibitory effect against A549 cell proliferation and glycolysis. Mechanistically, ACADM was a functional target of paeonol. We also showed that the m6A reader YTH domain containing 1 plays an important role in m6A-modified ACADM expression, which is negatively regulated by paeonol, and is involved in A549 cell proliferation and glycolytic reprogramming. These results indicated the central function of paeonol in regulating A549 cell glycolytic reprogramming and proliferation via m6A modification of ACADM.

LncRNA FENDRR with m6A RNA methylation regulates hypoxia-induced pulmonary artery endothelial cell pyroptosis by mediating DRP1 DNA methylation.

BACKGROUND: Pyroptosis is a form of programmed cell death involved in the pathophysiological progression of hypoxic pulmonary hypertension (HPH). Emerging evidence suggests that N6-methyladenosine (m6A)-modified transcripts of long noncoding RNAs (lncRNAs) are important regulators that participate in many diseases. However, whether m6A modified transcripts of lncRNAs can regulate pyroptosis in HPH progression remains unexplored. METHODS: The expression levels of FENDRR in hypoxic pulmonary artery endothelial cells (HPAECs) were detected by using quantitative real-time polymerase chain reaction (qRT-PCR) and fluorescence in situ hybridization (FISH). Western blot, Lactate dehydrogenase (LDH) release assay, Annexin V-FITC/PI double staining, Hoechst 33342/PI fluorescence staining and Caspase-1 activity assay were used to detect the role of FENDRR in HPAEC pyroptosis. The relationship between FENDRR and dynamin-related protein 1 (DRP1) was explored using bioinformatics analysis, Chromatin Isolation by RNA Purification (CHIRP), Electrophoretic mobility shift assay (EMSA) and Methylation-Specific PCR (MSP) assays. RNA immunoprecipitation (RIP) and m6A dot blot were used to detect the m6A modification levels of FENDRR. A hypoxia-induced mouse model of pulmonary hypertension (PH) was used to test preventive effect of conserved fragment TFO2 of FENDRR. RESULTS: We found that FENDRR was significantly downregulated in the nucleus of hypoxic HPAECs. FENDRR overexpression inhibited hypoxia-induced HPAEC pyroptosis. Additionally, DRP1 is a downstream target gene of FENDRR, and FENDRR formed an RNA-DNA triplex with the promoter of DRP1, which led to an increase in DRP1 promoter methylation that decreased the transcriptional level of DRP1. Notably, we illustrated that the m6A reader YTHDC1 plays an important role in m6A-modified FENDRR degradation. Additionally, conserved fragment TFO2 of FENDEE overexpression prevented HPH in vivo. CONCLUSION: In summary, our results demonstrated that m6A-induced decay of FENDRR promotes HPAEC pyroptosis by regulating DRP1 promoter methylation and thereby provides a novel potential target for HPH therapy.

Novel Counteraction Effect of H2O and SO2 toward HCl on the Chemical Adsorption of Gaseous Hg0 onto Sulfureted HPW/γ-Fe2O3 at Low Temperatures: Mechanism and Its Application in Hg0 Recovery from Coal-Fired Flue Gas.

In this work, sulfureted phosphotungstic acid-grafted γ-Fe2O3 (HPW/γ-Fe2O3) was investigated as a regenerable monolithic sorbent to recover gaseous Hg0 upstream of wet flue gas desulfurizations (FGDs), and the effects of HCl, SO2, and H2O on the chemical adsorption of Hg0 onto sulfureted HPW/γ-Fe2O3 were investigated with Hg balance analysis and kinetic analysis. Hg0 conversion over sulfureted HPW/γ-Fe2O3 was remarkably promoted in the presence of HCl, and most Hg0 was catalytically oxidized to HgCl2. Moreover, the chemical adsorption of Hg0 was notably restrained as the key species for Hg0 transformation to HgS (i.e., S22-) was rapidly oxidized by Cl*. However, the effect of HCl on Hg0 conversion over sulfureted HPW/γ-Fe2O3 was almost counteracted by H2O and SO2 as they competed with physically adsorbed Hg0 and S22- for the consumption of Cl*. Therefore, the chemical adsorption of Hg0 onto sulfureted HPW/γ-Fe2O3 in the presence of SO2 and H2O was slightly inhibited by HCl, and only a small amount of HgCl2 was formed. Moreover, sulfureted HPW/γ-Fe2O3 exhibited a moderate ability for gaseous HgCl2 adsorption. As a result, sulfureted HPW/γ-Fe2O3 showed excellent performance in recovering Hg0 from the flue gas upstream of the FGDs for the centralized control of Hg0 emitted from coal-fired plants.

Simultaneous Adsorption of Gaseous Hg0 and Hg(II) by Regenerable Monolithic FeMoSx/TiO2: Mechanism and its Application in the Centralized Control of Hg Pollution in Coal-Fired Flue Gas.

FeMoSx/TiO2 was investigated as a regenerable sorbent to simultaneously adsorb Hg0 and Hg(II) from coal-fired flue gas for the centralized control of Hg pollution discharged from coal-fired power plants. The performance of FeMoSx/TiO2 for Hg(II) and/or Hg0 adsorption was evaluated on a fixed-bed reactor at 80 oC, and the mutual interference between Hg0 adsorption and Hg(II) adsorption was analyzed using individual adsorption, simultaneous adsorption, and two-stage adsorption. FeMoSx/TiO2 displayed an excellent capacity for individual Hg0 adsorption (41.8 mg g-1) and a moderate capacity for individual Hg(II) adsorption (0.48 mg g-1). Two types of adsorption sites were present on FeMoSx/TiO2 for gaseous Hg adsorption (S0 and FeS2/MoS3 sites). X-ray photoelectron spectroscope and kinetic analyses demonstrated that Hg0 and Hg(II) could adsorb onto S0 sites, whereas only Hg0 was adsorbed onto FeS2/MoS3 sites. As Hg0 competed with Hg(II) for the S0 sites, the amount of Hg(II) adsorbed slightly decreased by 16% in the presence of Hg0. However, Hg0 adsorption onto the FeS2/MoS3 sites predominated over the Hg0 adsorption onto FeMoSx/TiO2 and it was not inhibited in the presence of Hg(II). Therefore, the amount of Hg0 adsorbed on FeMoSx/TiO2 was only decreased by 2% in the presence of Hg(II).

Incorporation of Chromophores into Metal-Organic Frameworks for Boosting CO2 Conversion.

The exploitation of highly stable and active catalysts for the conversion of CO2 into valuable fuels is desirable but is a great challenge. Herein, we report that the incorporation of chromophores into metal-organic frameworks (MOFs) could afford robust catalysts for efficient CO2 conversion. Specifically, a porous Nd(III) MOF (Nd-TTCA; TTCA3- = triphenylene-2,6,10-tricarboxylate) was constructed by incorporating one-dimensional Nd(CO2)n chains and TTCA3- ligands, which exhibits a very high stability, retaining its framework not only in the air at 300 °C for 2 h but also in boiling aqueous solutions at pH 1-12 for 7 days. More importantly, Nd-TTCA has achieved a 5-fold improvement in photocatalytic activity for reducing CO2 to HCOOH and a 10-fold improvement in catalytic activity for the cycloaddition of CO2 into cyclic carbonate in comparison to those of H3TTCA itself. This work gives a new strategy to design efficient artificial crystalline catalysts for CO2 conversion.

Novel Promotion of Sulfuration for Hg0 Conversion over V2O5-MoO3/TiO2 with HCl at Low Temperatures: Hg0 Adsorption, Hg0 Oxidation, and Hg2+ Adsorption.

In this work, the commercial selective catalytic reduction (SCR) catalyst V2O5-MoO3/TiO2 was sulfureted with H2S to improve both its capability for elemental mercury (Hg0) removal at low temperatures and its resistance to SO2 and H2O. Hg0 removal over both V2O5-MoO3/TiO2 and sulfureted V2O5-MoO3/TiO2 involved the catalytic oxidation of Hg0 to HgCl2 and the chemical adsorption of gaseous Hg0; therefore, the effect of sulfuration on Hg0 chemical adsorption and the catalytic oxidation of Hg0 to HgCl2 over V2O5-MoO3/TiO2 and its resistance to SO2 and H2O were investigated using Hg balance analysis. Kinetic analysis showed that the rates of the chemical adsorption and oxidation of Hg0 were both in direct proportion to the concentration of physically adsorbed Hg0. The physical adsorption of gaseous Hg0 on V2O5-MoO3/TiO2 was remarkably promoted after sulfuration, and the physical adsorption of gaseous Hg0 over sulfureted V2O5-MoO3/TiO2 was scarcely inhibited by SO2 and H2O. Therefore, the performance of V2O5-MoO3/TiO2 for Hg0 removal and its resistance to SO2 and H2O were both improved after sulfuration. Even more remarkably, sulfureted V2O5-MoO3/TiO2 can adsorb gaseous HgCl2, which resulted from Hg0 oxidation. Therefore, sulfureted V2O5-MoO3/TiO2 showed an excellent performance to recover Hg0 from coal-fired power plants, which can then be converted to liquid Hg.

Different Design Strategies for Metal Sulfide Sorbents to Capture Low Concentrations of Gaseous Hg0 in Coal-Fired Flue Gas and High Concentrations of Gaseous Hg0 in Smelting Flue Gas.

Capturing gaseous Hg0 using regenerable metal sulfides is a promising technology to recover gaseous Hg0 from both coal-fired flue gas (CFG) and smelting flue gas (SFG) for the centralized control. Gaseous Hg0 concentration in SFG is 2-3 orders of magnitude higher than that in CFG; therefore, the design strategy of metal sulfides for capturing gaseous Hg0 from CFG is quite different from that from SGF. In this work, the structure-activity relationship of metal sulfides to capture Hg0 was investigated according to the remarkable difference in MoO3 loading on sulfureted FeTiOx to capture low/high concentrations of gaseous Hg0. The rate of Hg0 adsorption onto metal sulfides was mainly related to the amounts of adsorption sites and S22- on the surface, the affinity of adsorption sites to gaseous Hg0, and the gaseous Hg0 concentration. Meanwhile, the capacity for Hg0 adsorption was approximately equal to the less of the amount of adsorption sites and S22- on the surface. Furthermore, capturing low concentrations of gaseous Hg0 from CFG required the metal sulfide sorbents having more adsorption sites with strong affinity to gaseous Hg0, while capturing high concentrations of gaseous Hg0 from SFG required the sorbents with enough adsorption sites.

Faster electron injection and higher interface reactivity in g-C3N4/Fe2O3 nanohybrid for efficient photo-Fenton-like activity toward antibiotics degradation.

Two different morphologies of Fe2O3 involving nanodots and nanosheets were deposited on g-C3N4 nanosheets by simple in-situ deposition and impregnation-hydrothermal methods, respectively. Structural effect of Fe2O3 on photo-Fenton-like activity and charge transfer at the interface in these two g-C3N4/Fe2O3 hybrids were studied. Detail characterizations on charge transfer kinetics revealed that g-C3N4/nanodot-Fe2O3 structure showed faster electron injection rate and higher injection efficiency (≈0.084 ns-1 and ≈27.5%) than g-C3N4/nanosheet-Fe2O3 counterpart (≈0.054 ns-1 and ≈19.5%). Stronger intimate junction between g-C3N4 nanosheets and Fe2O3 nanodots was believed to be the reason for faster and more efficient electron injection. In addition, stronger interaction with tetracycline and higher reactivity with H2O2 at the interface were observed for g-C3N4/nanodot-Fe2O3 compared with g-C3N4/nanosheet-Fe2O3. Thereby, under visible light stimulation, g-C3N4/nanodot-Fe2O3 demonstrated higher photo-Fenton-like tetracycline removal efficiency and rate (≈87% and ≈0.037 min-1) than g-C3N4/nanosheet-Fe2O3 (≈57% and ≈0.016 min-1). Furthermore, g-C3N4/nanodot-Fe2O3 junction can remain robust catalytic performance under various conditions (recycle experiment, real environment, different initial pHs and temperatures, anion coexistence, and other contaminants removal) and possible tetracycline degradation pathways were proposed. This study provided deep insights into structure-activity relationship and electron transfer between g-C3N4 and nanostructured Fe2O3, which can open a new avenge to develop Fe2O3-based photo-Fenton catalysts with high efficiencies for antibiotic wastewaters remediation.

Outstanding Performance of Magnetically Separable Sulfureted MoO3/Fe-Ti Spinel for Gaseous Hg0 Recovery from Smelting Flue Gas: Mechanism and Adsorption Kinetics.

To replace the hazardous and complicated Boliden-Norzink technology, the technology of Hg0 recovery from smelting flue gas by a magnetic and reproducible sulfureted MoO3/Fe-Ti spinel was employed to keep the produced H2SO4 free of Hg. The sulfureted MoO3/Fe-Ti spinel showed excellent performance in capturing gaseous Hg0, with an average adsorption rate of 93.3 µg g-1 min-1 and an adsorption capacity of 66.3 mg g-1 at 60 °C, which were much better than those of most of the other reported sorbents. Meanwhile, the sulfureted MoO3/Fe-Ti spinel exhibited excellent superparamagnetism and magnetization of 19.9 emu g-1, which ensured that it could easily be magnetically separated without a specialized precipitator or the molding of pulverous sorbents to monolithic sorbents. To investigate the promotion mechanism of MoO3 loading on Hg0 adsorption onto the sulfureted Fe-Ti spinel, the Hg0 adsorption kinetic parameters of the sulfureted MoO3/Fe-Ti spinel and sulfureted Fe-Ti spinel, resulting from the fitting of the adsorption breakthrough curves based on the kinetic model, were compared. The promotion of MoO3 loading was attributed to the remarkable increase in the adsorption sites on the sulfureted Fe-Ti spinel for Hg0 physical adsorption, which was mainly related to the formation of the MoS3 layer.

Novel Synergistic Effect of Fe and Mo in FeMoSx/TiO2 for Recovering High Concentrations of Gaseous Hg0 from Smelting Flue Gas: Reaction Mechanism and Kinetics.

There is a high demand for developing a more effective and environment-friendly technology to substitute the complicated and hazardous Boliden-Norzink technology for recovering gaseous Hg0 from smelting flue gas. In this work, a low-cost and reproducible sorbent (FeMoSx/TiO2) was developed to recover gaseous Hg0 from smelting flue gas. FeMoSx/TiO2 exhibited a superior ability for capturing high concentrations of Hg0, with an adsorption rate of 72.2 µg g-1 min-1 and a capacity of 41.8 mg g-1 at 60 °C. These were generally larger than the sums of those of FeSx/TiO2 and MoSx/TiO2. The kinetic model of Hg0 adsorption by FeSx/TiO2, MoSx/TiO2, and FeMoSx/TiO2 were constructed according to the adsorption mechanism. Then, the structure-activity relationship of FeMoSx/TiO2 for Hg0 capture was determined by comparing the kinetic parameters. The intrinsic adsorption of Hg0 by MoSx/TiO2 (i.e., physically adsorbed Hg0 was oxidized by MoS3 to HgS) was inhibited marginally after FeSx was incorporated. However, another Hg0 adsorption route (i.e., physically adsorbed Hg0 was oxidized by FeS2 to HgS) appeared on FeMoSx/TiO2. Its rate was significantly higher than that of FeSx/TiO2. Thus, a novel synergistic effect of Fe and Mo in FeMoSx/TiO2 for Hg0 capture was observed.

Significant Enhancement of Gaseous Elemental Mercury Recovery from Coal-Fired Flue Gas by Phosphomolybdic Acid Grafting on Sulfurated γ-Fe2O3: Performance and Mechanism.

The existing technologies to control Hg emissions from coal-fired power plants can be improved to achieve the centralized control of Hg0 emissions, which continue to pose a risk of Hg exposure to human populations. In this work, MoSx@γ-Fe2O3, formed by the sulfuration of phosphomolybdic acid (HPMo)-grafted γ-Fe2O3, was developed as a magnetic and regenerable sorbent to recover gaseous Hg0 from coal-fired flue gas as a cobenefit to the use of wet electrostatic precipitators. The thermal stability of γ-Fe2O3 was notably enhanced by HPMo grafting; thus, the magnetization of MoSx@γ-Fe2O3 hardly decreased during the application. The kinetic analysis indicates that the chemical adsorption of gaseous Hg0 was mainly dependent on the amounts of surface S22- and surface adsorption sites. Although the amount of S22- on sulfurated γ-Fe2O3 decreased after HPMo grafting, the amount of surface adsorption sites significantly increased due to the formation of a layered MoSx structure on the surface. Therefore, the ability of sulfurated γ-Fe2O3 to capture Hg0 was improved considerably after HPMo grafting. Furthermore, low concentrations of gaseous Hg0 in coal-fired flue gas can be gradually enriched by at least 1000 times by MoSx@γ-Fe2O3, which facilitates the recovery and centralized control of gaseous Hg0 in flue gas.

Acceleration of Hg0 Adsorption onto Natural Sphalerite by Cu2+ Activation during Flotation: Mechanism and Applications in Hg0 Recovery.

The rate of gaseous Hg0 adsorption onto natural sphalerite increased by approximately 1.9-7.7 times after Cu2+ activation during flotation of the natural sphalerite to remove impurities. Via a new pathway involving CuS, physically adsorbed Hg0 was oxidized by CuS to HgS on natural sphalerite after Cu2+ activation. In a similar intrinsic ZnS pathway, physically adsorbed Hg0 was oxidized by ZnS to HgS. The rate of the CuS pathway for Hg0 capture was generally significantly larger than that of the intrinsic ZnS pathway. Thus, Hg0 adsorption onto natural sphalerite was notably accelerated after Cu2+ activation. However, the kinetic analysis indicated that the capacity of natural sphalerite for Hg0 capture did not vary. Because the properties of the activated sphalerite for Zn smelting were barely degraded after Hg0 capture, the spent activated sphalerite for Hg0 capture can be reused for Zn smelting. Moreover, most of the gaseous Hg0 captured by activated sphalerite can be recovered eventually as liquid Hg0 in the condenser unit of Zn smelters. Thus, Hg0 recovery by activated sphalerite is a cost-effective and environmentally friendly technology to recover Hg0 from Zn smelting flue gas, thus replacing the complex and dangerous Boliden-Norzink process.

Recent advances in the use of microcarriers for cell cultures and their ex vivo and in vivo applications.

Microcarriers are 100- to 300-micron support matrices that permit the growth of adherent cells in bioreactor systems. They have a larger surface area to volume ratio in comparison to single cell monolayers, enabling cost-effective cell production and expansion. Microcarriers are composed of a solid matrix that must be separated from expanded cells during downstream processing stages. The detachment method is chosen on the basis of several factors like cell type, microcarrier surface chemistry, cell confluency and degree of aggregation. The development of microcarriers with a range of physiochemical properties permit controlled cell and protein associations that hold utility for novel therapeutics. In this review, we provide an overview of the recent advances in microcarrier cell culture technology. We also discuss its significance as an ex vivo research tool and the therapeutic potential of newly designed microcarrier systems in vivo.

Outstanding Performance of Recyclable Amorphous MoS3 Supported on TiO2 for Capturing High Concentrations of Gaseous Elemental Mercury: Mechanism, Kinetics, and Application.

Hg0 capture by sorbents was a promising technology to control Hg0 emission from coal-fired power plants and smelters. However, the design of a high performance sorbent and the predicting of the extent of Hg0 adsorption were both extremely limited due to the lack of adsorption kinetics and structure-activity relationship. In this work, the adsorption kinetics of gaseous Hg0 onto MoS3/TiO2 was investigated and kinetic parameters were obtained by fitting breakthrough curves. According to the kinetic parameters, the removal efficiency, the adsorption rate and the capacity for Hg0 capture were accurately predicted. Meanwhile, the structure-activity relationship of metal sulfides for gaseous Hg0 adsorption was built. The chemical adsorption rate of gaseous Hg0 was found to mainly depend on the amount of surface adsorption sites available for the physical adsorption of Hg0, the amount of surface S22- available for Hg0 oxidation and gaseous Hg0 concentration. As MoS3/TiO2 showed a superior performance for capturing high concentrations of Hg0 due to the large number of surface adsorption sites for the physical adsorption of gaseous Hg0, it has promising applications in recovering Hg0 from smelting flue gas.