Transition Metal Single-Atom Catalysts for the Electrocatalytic Nitrate Reduction: Mechanism, Synthesis, Characterization, Application, and Prospects.

Excessive accumulation of nitrate in the environment will affect human health. To combat nitrate pollution, chemical, biological, and physical technologies have been developed recently. The researcher favors electrocatalytic reduction nitrate reaction (NO3 RR) because of the low post-treatment cost and simple treatment conditions. Single-atom catalysts (SACs) offer great activity, exceptional selectivity, and enhanced stability in the field of NO3 RR because of their high atomic usage and distinctive structural characteristics. Recently, efficient transition metal-based SACs (TM-SACs) have emerged as promising candidates for NO3 RR. However, the real active sites of TM-SACs applied to NO3 RR and the key factors controlling catalytic performance in the reaction process remain ambiguous. Further understanding of the catalytic mechanism of TM-SACs applied to NO3 RR is of practical significance for exploring the design of stable and efficient SACs. In this review, from experimental and theoretical studies, the reaction mechanism, rate-determining steps, and essential variables affecting activity and selectivity are examined. The performance of SACs in terms of NO3 RR, characterization, and synthesis is then discussed. In order to promote and comprehend NO3 RR on TM-SACs, the design of TM-SACs is finally highlighted, together with the current problems, their remedies, and the way forward.

High areal capacitance of vanadium oxides intercalated Ti3C2 MXene for flexible supercapacitors with high mass loading.

Flexible all-solid-state supercapacitors (ASSSs) have caught the scientific attention to meet the explosive demand for portable and wearable electronic devices. However, it is difficult for flexible electrode materials to obtain a high areal capacitance at a high mass loading, which limits their commercial applications. In this study, vanadium oxide (V2O5) nanoparticles are introduced into Ti3C2 flakes with the aid of cetyltrimethylammonium bromide (CTAB). The intercalation of V2O5 particles in the interlayer of Ti3C2 establishes a hierarchical structure and facilitates the electrolyte penetration. As a result, the prepared CT-Ti3C2@V2O5 composite electrode achieves a high areal capacitance of 2065 mF cm-2 at 3 mA cm-2 and superior active mass loading (15 mg cm-2). Meanwhile, over 93% capacitance is maintained after 6000 cycles at 18 mA cm-2. The ASSS based on CT-Ti3C2@V2O5 delivers a high areal capacitance of 477 mF cm-2 at 1 mV s-1 and exhibits stable performance at different bending states, which reaches to the advanced level for the ASSSs based on MXenes.

Deep Dehalogenation of Florfenicol Using Crystalline CoP Nanosheet Arrays on a Ti Plate via Direct Cathodic Reduction and Atomic H.

Efficient elimination of antibacterial activity of halogenated antibiotics by dehalogenation pretreatment is desired for a biochemical treatment process. In this study, crystalline cobalt phosphide nanosheet arrays on a Ti plate (C-CoP/Ti) are fabricated by a simple electrodeposition and phosphorization process. The crystalline structure greatly promotes atomic hydrogen (H*) generation. Moreover, the nanosheet arrays can provide abundant active sites and accelerate electron transfer and mass transport. As a result, the dehalogenation rate of florfenicol (FLO, an emerging organic pollutant) on C-CoP/Ti is 11.1, 2.97, and 13.6 times higher than that on amorphous CoP/Ti, Pd/Ti, and bare Ti, respectively. The C-CoP/Ti electrode achieves 97.4% dehalogenation of FLO (20 mg L-1) within 30 min at -1.2 V (vs Ag/AgCl). Nearly 100% of Cl and 20% of F are broken away within 120 min, showing the highest electrocatalytic defluorination efficiency reported so far. Both experimental results and theoretical calculations reveal that the dehalogenation of FLO on C-CoP/Ti is synergistically accomplished via direct reduction of electron transfer and indirect reduction of H*. This study develops a highly efficient non-noble metal electrode material for dehalogenation of halogenated organic compounds.

Removal and Recovery of Uranium from Groundwater Using Direct Electrochemical Reduction Method: Performance and Implications.

Removal of uranium from groundwater is of great significance as compared to in situ bioimmobilization technology. In this study, a novel direct electro-reductive method has been developed to efficiently remove and recover uranium from carbonate-containing groundwater, where U(VI)O2(CO3)34- and Ca2U(VI)O2(CO3)3 are the dominant U species. The transferred electron calculations and XPS, XRD analyses confirmed that U(VI) was reduced to U(IV)O2 and accumulated on the surface of the Ti electrode (defined as Ti@U(IV)O2 electrode) with high current efficiencies (over 90.0%). Moreover, over 98.0% of the accumulated U(IV)O2 could be recovered by soaking the Ti@U(IV)O2 electrode in the dilute nitric acid. Results demonstrated that the accumulated U(IV)O2 on the surface of the Ti electrode played a key role in the removal of U(VI), which can promote the electro-reduction of U(VI). Therefore, the electrode could be used repeatedly and has a high removal capacity of U(VI) due to the continuous accumulation of active U(IV)O2 on the surface of the electrode. Significantly, the uranium in both real and high salinity groundwater can be efficiently removed. This study implies that the proposed direct electro-reductive method has great potential for the removal and recovery of uranium from groundwater and uranium-containing wastewater.

[Performance of FibroScan in evaluating the curative effects of traditional Chinese medicine on liver fibrosis].

OBJECTIVE: To assess the performance of FibroScan in evaluating the curative effects of traditional Chinese medicine (TCM) on liver fibrosis, and to analyze factors influencing the diagnostic accuracy. METHODS: Data of FibroScan values, types of disease, use of drug, liver function indexes, prothrombin time (PT) and international normalized ratio (INR) were collected at both pre- (1 month prior) and post-FibroScan for 102 patients who underwent at least two FibroScan procedures. Patients were subgrouped according to presence of fibrosis, presence of cirrhosis, and TCM formulation and statistically analyzed. RESULTS: The pre- and post-FibroScan mean liver stiffness measurements (LSMs) were significantly different when the variation of LSM was more than or equal to2 kPa for the non-fibrotic group (vs. the fibrotic group), or when the variation wasmore than or equal to4 kPa for the cirrhotic group (vs. the non-cirrhotic group). In addition, the three TCM formulation groups showed significant differences, with the most robust difference exhibited between the FuZheng HuaYu formulation group and the other treatment groups (P = 0.010). No significant differences were observed for the liver function indexes, PT, or INR. However, the post-FibroScan levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyltransferase (GGT) was significantly reduced in patients with reduced LSM. CONCLUSION: FibroScan may be a useful non-invasive clinical tool for evaluating the comprehensive curative effect of treatments for chronic liver diseases, and its performance is not obviously impacted by ALT, AST, GGT, PT, and INR. The criteria for efficacy established by FibroScan are 2 kPa for the patients without liver fibrosis and 4 kPa for patients with liver cirrhosis.

Recent Advances in Carbon-Based Single-Atom Catalysts for Electrochemical Oxygen Reduction to Hydrogen Peroxide in Acidic Media.

Electrochemical oxygen reduction reaction (ORR) via the 2e- pathway in an acidic media shows great techno-economic potential for the production of hydrogen peroxide. Currently, carbon-based single-atom catalysts (C-SACs) have attracted extensive attention due to their tunable electronic structures, low cost, and sufficient stability in acidic media. This review summarizes recent advances in metal centers and their coordination environment in C-SACs for 2e--ORR. Firstly, the reaction mechanism of 2e--ORR on the active sites of C-SACs is systematically presented. Secondly, the structural regulation strategies for the active sites of 2e--ORR are further summarized, including the metal active center, its species and configurations of nitrogen coordination or heteroatom coordination, and their near functional groups or substitute groups, which would provide available and proper ideas for developing superior acidic 2e--ORR electrocatalysts of C-SACs. Finally, we propose the current challenges and future opportunities regarding the acidic 2e--ORR pathway on C-SACs, which will eventually accelerate the development of the distributed H2O2 electrosynthesis process.

Noble-metal-free Co-N-C catalyst derived from cellulose-based poly(ionic liquid)s for highly efficient oxygen reduction reaction.

Noble-Metal-Free nitrogen-doped carbon-based materials are promising electrocatalysts for oxygen reduction reaction (ORR), yet it remains a great challenge to construct efficient porous non-noble metal nitrogen-doped carbon (M-N-C) catalysts with uniform distribution, due to the easy aggregation of metals. Herein, we reported the synthesis and assessment of a novel and efficient noble-metal-free catalyst for oxygen reduction reaction (ORR) from pyrolysis of a cobalt-containing cellulosic poly(ionic liquid) (Co-N-C). The prepared Co-N-C catalyst possesses high surface area, hierarchical porous structure, well-dispersed Co nanoparticles and large amounts of low-coordinated Co active sites. Especially, the Co-N-C-850 sample exhibits a high ORR activity (Eonset = 0.827 V, E1/2 = 0.74 V) that can rival 20 wt% commercial Pt/C (Eonset = 0.833 V, E1/2 = 0.71 V) in alkaline media. Moreover, the Co-N-C-850 sample also shows excellent anti-methanol poisoning activity and long-term stability toward ORR compared with commercial Pt/C. Our study provides a promising avenue both for the development of non-noble M-N-C catalysts for fuel cells and the functional utilization of cellulose.

The synthesis of multifunctional cellulose graft alternating copolymers of 3,4-dihydrocoumarin and epoxides in DBU/DMSO/CO2 solvent system.

Cellulose graft copolymers having well-defined structures could incorporate the characteristics of both the cellulose skeleton and side chains, providing a new method for the preparation functionalised cellulose derivatives. Herein, a series of multifunctional cellulose grafted, alternating 3,4-dihydrocoumarin (DHC) and epoxide (EPO) copolymers (cell-g-P(DHC-alt-EPO)) were prepared in a metal-free DBU/DMSO/CO2 solvent system without adding additional catalyst. Four examples of cell-g-P(DHC-alt-EPO) with tunable thermal and optical properties were synthesized by copolymerization of DHC with styrene oxide (SO), propylene oxide (PO), cyclohexene oxide (CHO) or furfuryl glycidyl ether (FGE) onto cellulose. The nonconjugated cell-g-P(DHC-alt-EPO) showed UV absorption properties with the maximum absorption peak at 282 nm and 295 nm and photoluminescence performance. A clustering-triggered emission mechanism was confirmed and consistent with DFT theoretical calculations. In DMSO solution, the copolymer (DHCSO5) with DP of 11.64 showed ACQ behaviour as the concentration increased. In addition, DHCSO5 had good antioxidant capacity with an instantaneous radical scavenging activity of 2,2-diphenyl-1-picrylhydrazine (DPPH) up to 65 % at a concentration of 40 mg/ ml and increased to 100 % after 30 min. Thus, the multifunctional cell-g-P(DHC-alt-EPO) materials had a variety of potential applications in the fields of fluorescent printing, bio-imaging, UV- shielding and antioxidants.

Effects of vitamin E on mercuric chloride-induced renal interstitial fibrosis in rats and the antioxidative mechanism.

OBJECTIVE: To observe the effects of vitamin E (Vit E) on mercuric chloride (HgCl2)-induced renal interstitial fibrosis (RIF) in rats and discuss its antioxidative mechanism. METHODS: A total of 32 Sprague-Dawley rats were randomly assigned to three groups: normal group, model group and Vit E group. RIF was induced by oral administration of HgCl(2) at a dose of 8 mg/kg body weight once a day for 9 weeks. Rats in Vit E group were administered with Vit E capsule at 100 mg/kg body weight, and rats in normal and model groups were treated with normal saline. At the end of the 9th week, rats were sacrificed and renal hydroxyproline (Hyp)'s trichrome and periodic acid-silver methenamine (PASM) staining. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and contents of glutathione (GSH) and malondialdehyde (MDA) in kidney tissue were tested with commercial kits. The expressions of nuclear factor-κB (NF-κB), inhibitor-κB (IκB), phospho-IκB (p-IκB) and tumor necrosis factor-α (TNF-α) were determined by Western blot. The expression of α-smooth muscle actin (α-SMA) was assayed by Western blot and immunofluorescent staining. RESULTS: Renal Hyp content, HE, Masson's trichrome and PASM staining results and α-SMA expression confirmed development of HgCl2-induced RIF in rats. Oxidative stress markers GSH, GSH-Px and MDA confirmed oxidative stress in RIF rats. Compared with model rats, rats in Vit E group had lower kidney Hyp content (P<0.01). GSH and MDA contents decreased significantly in Vit E group compared with model group (P<0.01). The expressions of NF-κB and IκB had no significant difference among all groups (P>0.05). In Vit E group, the expressions of p-IκB and TNF-α decreased significantly compared with model group (P<0.01). The expression of α-SMA in Vit E group was also decreased significantly compared with model group (P<0.01). CONCLUSION: Vit E has a protective effect on experimental RIF induced by HgCl(2) in rats and it is related to inhibition of lipid peroxidation, which involves blocking of NF-κB signaling pathway and the activation of cells producing extracellular matrix.

[Biochemical characteristics of traditional Chinese medicine syndromes and their elements in patients with hepatitis B cirrhosis].

OBJECTIVE: To investigate the characteristics of traditional Chinese medicine (TCM) syndromes and their elements in patients with post hepatitic cirrhosis by analyzing the relationships between signs and symptoms and biochemical parameters. METHODS: A total of 440 patients with hepatitis B cirrhosis treated in Shanghai Public Health Center and Shuguang Hospital, Longhua Hospital and Central Hospital of Putuo District Affiliated to Shanghai University of Traditional Chinese Medicine during January 2002 to January 2006 were enrolled in this study. Signs and symptoms and biochemical information of patients were collected by using a self-designed questionnaire regarding the four examinations of TCM. Signs and symptoms were firstly analyzed to find the frequency of occurrence. Then, the patients were divided into two groups according to non-existent or existent sign and symptom and the correlations between the signs and symptoms which occurred most frequently and their biochemical parameters were analyzed. RESULTS: Sixteen symptoms which occurred most frequently were fatigue, colored urine, liver palms, opaque complexion, string-like pulse, weakness at waist and knees, dry month and bitter taste in the mouth, profuse dreaminess and poor sleepiness, heaviness of limbs, abdominal distention, yellow eyes, fine pulse, impetuosity and susceptibility to rage, splenomegaly, poor appetite, and distension and fullness in the chest and hypochondrium. A previous study on syndrome differentiation of 900 patients with post hepatitic cirrhosis showed 4 syndrome patterns: internal accumulation of dampness-heat, liver-kidney yin deficiency, internal accumulation of blood stasis-heat, and liver depression and spleen deficiency. Further analysis showed that internal accumulation of dampness-heat syndrome was characterized by obvious hepatic inflammation, poor synthesis function and more ascites. Liver-kidney yin deficiency syndrome was characterized by low-level hepatic inflammation, poor synthesis function and more ascites. Internal accumulation of blood stasis-heat syndrome was characterized by low-level hepatic inflammation, poorer synthesis function, ascites and splenomegalia, and liver depression and spleen deficiency syndrome was characterized by slight hepatic inflammation, synthesis function injury, decreased internal portal vein diameter and less ascites. CONCLUSION: Different syndrome patterns have different pathological features, showing the complexity and polymorphism of syndrome construction.

Tuning the Oxidation State of Cu Electrodes for Selective Electrosynthesis of Ammonia from Nitrate.

Electrochemical reduction of nitrate (NO3-) to ammonia (NH3) provides a promising route for recycling nitrate from wastewater to balance the nitrogen cycle and sustainable production of ammonia. Among various catalytic materials for NO3- electroreduction, Cu shows a favorable selectivity to NH3. However, Cu can be easily oxidized, while the effect of the Cu oxidation state on NO3- reduction remains to be elucidated. Here, we report that oxidic Cu formed on a Cu electrode can enhance its activity and selectivity for NO3- reduction to NH3. We first used a polished Cu foil as a model catalyst for NO3- reduction and found that a brief exposure of the Cu electrode to air could increase its yield rate and Faradaic efficiency for NH3 production. The improved catalytic performance was attributed to the formed Cu+ sites that can reduce the energy barrier for NO3- reduction to NH3 and suppress the competing HER reaction. Based on this finding, an oxide-derived Cu (OD-Cu) electrode was prepared by annealing a Cu foil in O2 gas followed by electroreduction, which exhibited superior performance for NO3- reduction to NH3, with a Faradaic efficiency of 92% and a yield rate of 1.1 mmol h-1 cm-2 for NH3 production at -0.15 V versus reversible hydrogen electrode. Moreover, an OD-Cu foam electrode was similarly developed to demonstrate NO3- recycling from a low-concentration NO3- solution, which showed a nearly 100% conversion of NO3- to NH3 using a circulating flow cell.

Salvianolic acid B prevents epithelial-to-mesenchymal transition through the TGF-beta1 signal transduction pathway in vivo and in vitro.

BACKGROUND: Salvianolic Acid B (Sal B) is a water-soluble component from Danshen (a traditional Chinese herb widely used for chronic renal diseases) with anti-oxidative and cell protective properties. Sal B also has potential protective effects on renal diseases. Tubular epithelial cells can undergo epithelial-to-mesenchymal transition (EMT), which plays an important role in the pathogenesis of renal interstitial fibrosis (RIF) and is mainly regulated by TGF-beta1/Smads pathway. The aims of the study are to investigate the effect of Sal B on tubular EMT in vivo and in vitro, and to elucidate its underlying mechanism against EMT related to TGF-beta1/Smads pathway. RESULTS: For in vivo experiments, RIF was induced in rats by oral administration of HgCl2 and prophylaxised with Sal B and vitamin E. The protein expression of E-cadherin was down-regulated, while the expression of alpha-SMA, TGF-beta1, TbetaR-I, p-Smad2/3 and the activity of matrix metalloproteinase-2 (MMP-2) were up-regulated in kidneys of model rats when compared with those of normal rats. In contrast, Sal B and vitamin E significantly attenuated the expression of alpha-SMA, TGF-beta1, TbetaR-I, p-Smad2/3, and MMP-2 activity, but increased E-cadherin expression. For in vitro experiments, HK-2 cells were incubated with TGF-beta1 to induce EMT, and the cells were co-cultured with 1 and 10 microM Sal B or SB-431542 (a specific inhibitor of TbetaR-I kinase). TGF-beta1 induced a typical EMT in HK-2 cells, while it was blocked by Sal B and SB-431542, as evidenced by blocking morphologic transformation, restoring E-cadherin and CK-18 expression, inhibiting alpha-SMA expression and F-actin reorganization, and down-regulating MMP-2/9 activities in TGF-beta1 mediated HK-2 cells. Furthermore, Sal B and SB-431542 profoundly down-regulated the expressions of TbetaR-I and p-Smad2/3 but prevented the decreased expression of Smad7 in TGF-beta1 stimulated HK-2 cells. CONCLUSIONS: Sal B can prevent tubular EMT in the fibrotic kidney induced by HgCl2 as well as HK-2 cells triggered by TGF-beta1, the mechanism of Sal B is closely related to the regulation of TGF-beta1/Smads pathway, manifested as the inhibition of TGF-beta1 expression, suppression of TbetaR-I expression and function, down-regulation of Smad2/3 phosphorylation, and restoration of the down-regulation of Smad7, as well as inhibition of MMP-2 activity.

[Effects of fuzheng huayu recipe in antagonizing rat's renal interstitial fibrosis].

OBJECTIVE: To observe the effects of Fuzheng Huayu Recipe (FHR) on rat's renal interstitial fibrosis induced by mercuric chloride (HgCl2), and to explore preliminarily its mechanism of action. METHODS: Rats were randomly divided into four groups: the normal group, the model group, the FHR group and the vitamin E group, the latter two were treated respectively by FHR 4.6 g/kg and vitamin E 100 mg/kg. Rats model was established by oral administration of 8 mg/kg HgCl2 for 9 weeks. Serum creatinine (Cr) and urea nitrogen (BUN) content were tested with corresponding test kits; hydroxyproline (Hyp) content in kidney was assayed with hydrochloric acid hydrolysis; renal histologic change was observed with HE, Masson and methenamine silver (PASM) staining; and collagen type I (Col I), as well as protein expressions of fibronectin (FN) and alpha-smooth muscle actin (alpha-SMA) was determined with Western blot. RESULTS: Compared with the model group, the kidney/body weight ratio, serum levels of Cr and BUN, kidney Hyp content, and severity of renal interstitial fibrosis in the two treated groups were significantly lower (P<0.05 or P<0.01), and the improvements were more significant in the FHR group than those in the vitamin E group; Col I and FN protein expression was also weaker in the two treated group (Col, P<0.05; FN, P<0.01); while the expression of alpha-SMA was lower in the FHR group (P<0.01), but it wasn't in the vitamin E group (P>0.05). CONCLUSION: FHR could improve the HgCl2-induced renal function injury in rats, decrease extracellular matrix deposition and restrain renal interstitial fibrosis, the mechanism of action might be related with its inhibitory effect on myofibroblast activation.

Efficient Photocatalytic Hydrogen Evolution and CO2 Reduction: Enhanced Light Absorption, Charge Separation, and Hydrophilicity by Tailoring Terminal and Linker Units in g-C3N4.

Although graphitic carbon nitride (g-C3N4) has been identified as a promising photocatalyst, pristine g-C3N4 has a limited light absorption, insolubility, small specific surface area, and rapid electron-hole pair recombination. In this study, hydroxyl-grafted oxygen-linked tri-s-triazine-based polymer (HGONTP) is achieved through the polycondensation of hydrothermally pretreated dicyandiamide (DCDA). The content of C-O-C linkers and terminal OH groups in HGONTP can be regulated by the cyclization and hydrolysis degrees of DCDA through the replacement of the pendant NH2 groups with OH groups. The HGONTP photocatalyst exhibits an outstanding light absorption from UV to near-IR, possessing a narrow band gap of 2.18 eV, a hydrophilic surface, a large specific surface area of 96.1 m2 g-1, and reduced charge recombination. As a result, HGONTP exhibits a hydrogen evolution rate 27.7-fold higher than that for pristine g-C3N4 (6.54 vs 0.236 mmol g-1 h-1). The apparent quantum yield reaches 12.6% at 420 nm and 4.1% at 500 nm. In addition, the photocatalytic conversion efficiency of CO2 to CO reaches as high as 3.3 µmol g-1 h-1 without cocatalysts and sacrificial agents. The selectivity of CO2 to CO achieves 88.4%. The proposed strategy paves a new avenue to design high-performance polymeric photocatalysts used in water.

Embedding few-layer Ti3C2Tx into alkalized g-C3N4 nanosheets for efficient photocatalytic degradation.

Solution of the increasingly important problem of aquatic pollution requires the use of an economical, energy-efficient, highly effective and environmentally-friendly catalyst. Polymeric carbon nitride (C3N4) has shown to be a promising metal-free photocatalyst that however suffers from strong charge recombination and poor conductivity, while MXenes have shown to be perfect co-catalysts for the photocatalytic process but show poor stability. In this study, we successfully constructed a robust heterostructure photocatalyst in which few-layer Ti3C2Tx was embedded into alkalized C3N4 without being oxidized. The photocatalyst showed stable and effective photocatalytic performance for the removal of tetracycline hydrochloride and other organic compounds under visible light irradiation. Different characterization methods were used to elucidate the morphology and structure of the as-prepared photocatalyst. The robust heterostructure and the intimate interaction between the two constituents of the composite were verified. Based on the van der Waals heterostructure, Ti3C2Tx acts as the electron acceptor and helps to form Schottky junction, preventing charge recombination of the photocatalyst. And in the meantime, the electrons from C3N4 protect Ti3C2Tx from oxidation. SEM and XRD results demonstrated that the Ti3C2Tx structure remains unchanged after calcination and after photodegradation experiments. Furthermore, a possible mechanism for photocatalytic tetracycline hydrochloride degradation was proposed based on the results of radical scavenging experiments. This work provides a strategy to strengthen heterostructure between 2D materials, and shows that carbon nitride and Mxenes could be promising materials for photocatalytic wastewater pre-treatment applications.

Impacts of event-specific air quality improvements on total hospital admissions and reduced systemic inflammation in COPD patients.

There is limited evidence linking the impacts of reduced air pollution on hospital admissions. The potential biological mechanisms are still not completely understood. This study examined the effects of mitigated ambient pollution on hospital admissions and inflammatory biomarker levels in chronic obstructive pulmonary disease (COPD) COPD patients. Daily hospital admissions were compared over 51 days associated with the Asian Games period (Nov 1-Dec 21, 2010) with the identical calendar dates of baseline years (2004-2009 and 2011-2013). A three-year cohort study was conducted with 36 COPD patient participants. The daily particulate matter (PM10) decreased from 65.86 µg/m3 during the baseline period to 62.63 µg/m3 during the Asian Games period; the daily NO2 level decreased from 51.33 µg/m3 to 42.63 µg/m3. Between the baseline period and the Asian Games, daily hospital admissions from non-accidental diseases decreased from 116 to 93, respectively; respiratory diseases decreased from 20 to 17, respectively; and cardiovascular diseases decreased from 11 to 9 during the Asian Games period, respectively. No statistically significant reductions were seen in the remaining months of 2010 in Guangzhou, during the the Asian Games period in the control city, and two other control diseases. Furthermore, we identified significant improvement in CRP and fibrinogen by -20.4% and -15.4% from a pre-Asian game period to a during-Asian game period, respectively. For CRP, we found significant increases in NO2 at lag1-3 days after-Asian game period and significant increases in PM10 at lag1-2 days. Similar effects were also seen with fibrinogen. This discovery provides support for efforts to diminish air pollution and improve public health through human air pollutants intervention. Improved air pollution during the 2010 Asian games was correlated with decreases in biomarkers associated with systemic inflammation in COPD patient participants.

Non-inflammatory emphysema induced by NO2 chronic exposure and intervention with demethylation 5-Azacytidine.

AIMS: A rat model of emphysema was established that mimics the features of the human emphysema subtype and explores the effects of demethylation on lung function and blood tests. MATERIALS AND METHODS: Rats were randomly assigned to NO2, NO2 + 5-Azacytidine, and normal air groups based on a emphysema rat model induced by chronic NO2 exposure. This study estimates the characteristics of emphysema by conducting an analysis for IL-6 and TNF-α levels in bronchoalveolar lavage fluids (BALF) and plasma. Furthermore, CD68 macrophage immunofluorescent staining and inflammatory cell counts in BALF were compared between rats exposed to NO2 and normal air. KEY FINDINGS: 5-Azacytidine treatment led to restored ∆weight at 14 and 75 days of intervention and NO2 + 5-Azacytidine significantly reversed the effect of NO2 exposure on ∆weight. Intervention with 5-Azacytidine alleviated the decline of pulmonary function with a significant increase in FEV100/FVC% at 75 days in NO2 + 5-Azacytidine rats compared to NO2 rats. 5-Azacytidine reduced the counts of white blood cells (WBCs), granulocytes, lymphocytes, and monocytes at 14 days, but increased WBC, granulocyte, and monocyte counts at 45 days. Red blood cell counts, hemoglobin, and hematocrit concentrations were significantly reduced in NO2 + 5-Azacytidine rats. SIGNIFICANCE: This non-inflammatory rat emphysema model (induced by chronic NO2 exposure with global DNA hypomethylation and demethylation therapy with 5-Azacytidine) effectively improved emphysema by alleviating the decline of lung function and hypoxia, and slightly reinforced immune function. These results indicate the therapeutic potential of demethylation agents for the prevention and treatment of emphysema induced by the air pollutant NO2.

Regionalized and vectorial charges transferring of Cd1-xZnxS twin nanocrystal homojunctions for visible-light driven photocatalytic applications.

In photocatalyst designing, quick recombination of photo-generated electron-hole pairs in the bulk or on the surface of semiconductors is a major limiting factor in achieving high photocatalytic efficiency, which is one of the most knotty scientific issues. For this purpose, a series of Cd1-xZnxS twin nanocrystal (NC) zinc blende/wurtzite (ZB/WZ) homojunctions photocatalysts were synthesized by a facile solvothermal route and innovatively employed in photocatalytic degradation. In sample Cd0.6Zn0.4S, ZB and WZ phases have the largest distribution and closest interconnection at atomic level. The type-II staggered band alignment formed between two phases made photo-generated electrons and holes spatially separated to ZB (away from twin plane) and WZ (to twin plane) regions, and the ordered arrangement of redox reaction's active sites was then realized inside a single semiconductor. Finally, photocatalytic activities of the samples were evaluated by degradation of methylene blue (MB) upon visible light irradiation. The optimal Cd0.6Zn0.4S NCs without any co-catalyst loading showed high photocatalytic activity with degradation efficiency of 95% in 80 min and performed excellent photostability. Furthermore, photocatalytic degradation and electron transfer mechanisms in Cd0.6Zn0.4S twin NCs are studied particularly. Inner twin structure homojunction has provided a new insight into the crystalline phase engineering.

"Dark Deposition" of Ag Nanoparticles on TiO2: Improvement of Electron Storage Capacity To Boost "Memory Catalysis" Activity.

"Memory catalysis" (MC) studies have received appreciable attention recently because of the unique talent to retain the catalytic performance in the dark condition. However, the MC activity is still low owing to the relatively limited electron storage capacity of the present materials. Here, a TiO2@Ag composite was synthesized by a "dark-deposition (DD)" method, which is based on the electron trap effect of TiO2. Unlike traditional photodeposition (PD), an exploration of the morphology and chemical compositions of as-prepared samples shows that DD can inhibit the growth of Ag nanoparticles and the formation of Ag2O, which greatly improve the electron storage capacity. We further demonstrated that the maximum electronic capacity was in the order of TiO2@Ag-DD (1 µmol/mg) > TiO2@Ag-PD (0.35 µmol/mg) > TiO2 (0.11 µmol/mg). Moreover, the enhanced MC activity was confirmed by various degradation experiments. Especially, the use of TiO2@Ag-DD as a round-the-clock catalyst for the degradation of multicomponent pollutants has also been achieved. This strategy opens a door for enhancing the MC activity and reveals that the coupling of photocatalysis and MC may provide a new opportunity for the continuous removal of pollutants in day and night. It also may be extended to other fields, such as energy storage and continuous disinfection.

Electrocatalytic dechlorination of halogenated antibiotics via synergistic effect of chlorine-cobalt bond and atomic H.

Although noble metal electrocatalysts are highly efficient in the dehalogenation of halogenated antibiotics, the prohibitive cost hinders their practical applications. In this study, a cobalt-phosphorous/oxide (CoP/O) composite prepared via a one-step electrodeposition was for the first time applied in electroreductive dechlorination of halogenated antibiotics (HA), including chloramphenicol (CAP), florfenicol (FLO) and thiamphenicol (TAP). CoP/O had a higher FLO dechlorination efficiency (91%) than Pd/C (69.3%) (t = 60 min, C0 = 20 mg L-1, applied voltage of -1.2 V vs. saturated calomel electrode (SCE)). Furthermore, the dechlorination efficiencies of CoP/O for CAP and TAP reached to 98.7 and 74.2%, respectively. The electron spin resonance and in situ Raman characterizations confirmed that atomic H* was produced via the CoP and the formation of CoCl bonds occurred on the CoO in CoP/O. The CoCl bond formation could trap HA molecules onto CoP/O and weaken the CCl bond strength. The synergistic effect of H* attack and CoCl bond was responsible for the high dechlorination efficiency. This study offers new insights into the interface mechanism of electroreductive dehalogenation process, and shows a great potential for the remediation of halogenated antibiotics contaminated wastewater.