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1.
J Nanosci Nanotechnol ; 20(2): 769-778, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31383072

RESUMO

A super absorbent was synthesized from calcium-aluminum waste residue of aluminum industrial using a facile hydrothermal method. The XRD results revealed that the main phase of hydrothermal product at 120 °C is CaSO4 ·2H2O, with a small amount of Al(OH)3. The as-prepared products were used to investigate the adsorptive applications in Congo red (CR) removal, and the results showed that the products treated at 120 °C had the best adsorption properties. The maximum adsorption capacity reaches about 1860.11 mg/g with a removal rate of 99.75%. Furthermore, the used adsorbent could be regenerated for at least four cycles through a calcination procedure, indicating its potential as an excellent adsorbent for the removal of CR dye from wastewater. The adsorption behavior was analyzed by Langmuir, Freundlich and Sips isotherms, and the adsorption proved to be a multilayer adsorption. This facile method presented here may provide promise synthesis of high-effective and low-cost adsorbents from industrial solid waste and achieve the goal of "using waste to treat waste" in the future.

2.
J Environ Radioact ; 208-209: 106027, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31442938

RESUMO

Nonreductive biomineralization of uranium is a promising methodology for the removal of uranium contamination as it provides stable products and wide applications. However, the efficiency of mineralization has become a major obstacle for the removal of uranium contamination by this technology, and the mineralizing process still remains largely obscure. To solve this problem in a practical way, we report a fast nonreductive biomineralization process of uranium by Bacillus subtilis ATCC-6633, a widespread bacterium with environmentally-friendly applications. In this system, we demonstrated that the size and crystallization degree of the obtained nonreduced biomineralized products is significantly superior to the results reported in the literature under comparable conditions. Meanwhile, combined with SEM, TEM, and FT-IR, a mineralization process of uranium transfer from the outer surface of the Bacillus subtilis ATCC-6633 to the internal has been clearly observed, which was accompanied by the evolution of amorphous U(VI) to crystalline uramphite. This work uncovers whole-process insights into the nonreductive biomineralization of uranium by Bacillus subtilis ATCC-6633, paving a new way for the rapid and sustained removal of uranium contamination.

3.
J Hazard Mater ; : 120614, 2019 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-31378419

RESUMO

Heavy metal-containing gypsum is a widespread hazardous waste. In this work, H+ was found to be the most essential factor of the mineralizers in hydrothermal treatment to completely (≥99.8%) extract Cr(VI) from gypsum waste to the supernatant, where the significant growth (from several µm to several hundreds of µm) and perfection of the gypsum crystals were observed. Moreover, with increasing concentration of H+, the crystal growth (undergoing Ostwald ripening process) was accelerated and the phase transformation temperature of gypsum was decreased from 110℃ (at 0.2 mol/L of HCl) to 100℃ (at 0.3 mol/L of HCl), which are favorable to enhance Cr(VI) extraction efficiency. Pilot experiments further certified this method to be practicable even in ton-scale. This work proposes a practicable and universal method to completely extract Cr(VI) from gypsum waste, and would also inspire the recycle of gypsum waste containing other heavy metals, such as As, Pb, Cd, and Hg.

4.
Environ Pollut ; 254(Pt A): 112961, 2019 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31398635

RESUMO

CoFe2O4/C nano-sheets (NSs) have been synthesized by a facile molten salt method using cheap potassium fulvate as carbon source and sodium chloride as template. The morphology, crystallinity and composition of the materials were analyzed by TEM, XRD and XPS. The study on the catalytic performance of 4-nitrophenol (4-NP) shows that CoFe2O4/C-600 nano-catalyst has the highest catalytic activity and the corresponding apparent constant is 1.91 min-1, this result is higher than that reported in most literatures. Catalytic kinetics of 4-NP reduction was studied in this article, and activation energy (Ea) was calculated to be 14.31 kJ mol-1. The catalyst also shows good cycle performance and stability. This convenient method provides a reference for the synthesis of MFe2O4/C and other nano-metal oxides/C nanocomposite catalysts.

5.
Int J Biometeorol ; 2019 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-31302762

RESUMO

Outdoor microclimatic conditions strongly affect the thermal comfort of pedestrians. A transversal field survey was conducted in Guangzhou, together with micrometeorological measurements. The outdoor physiological equivalent temperature (PET) varied from 3 to 59 °C. Regression lines were obtained to establish correlations of the mean thermal sensation vote (MTSV) with the PET bins with a width of 1 °C. Furthermore, the thermal comfort range of PET, neutral PET (NPET), and preferred PET was analyzed. The results indicated that, for the young people, thermal comfort range of PET spanned from 19.2 to 24.6 °C. The NPET and preferred PET significantly differed in different seasons. The NPET was higher in the summer than that in the winter and transitional seasons. However, the preferred PET of the summer was lower than that of the winter. The PET limits of different thermal stress categories were also confirmed, which differed from those in other cities. Thus, the impacts of adaptation on thermal comfort range were significant for people in outdoor environment.

6.
Environ Pollut ; 253: 680-707, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31330359

RESUMO

Solid wastes containing potentially toxic elements (PTEs) are widely generated around the globe. Critical concerns have been raised over their impacts on human health and the environment, especially for the exposure to PTEs during the transfer and disposal of the wastes. It is important to devise highly-efficient and cost-effective treatment technologies for the removal or immobilisation of PTEs in solid wastes. However, there is an inadequate overview of the global flow of PTEs-contaminated solid wastes in terms of geographical distribution patterns, which is vital information for decision making in sustainable waste management. Moreover, in view of the scarcity of resources and the call for a circular economy, there is a pressing need to recover materials (e.g., precious metals and rare earth elements) from waste streams and this is a more sustainable and environmentally friendly practice compared with ore mining. Therefore, this article aims to give a thorough overview to the global flow of PTEs and the recovery of waste materials. This review first summarises PTEs content in various types of solid wastes; then, toxic metal(loid)s, radioactive elements, and rare earth elements are critically reviewed, with respect to their patterns of transport transformation and risks in the changing environment. Different treatments for the management of these contaminated solid wastes are discussed. Based on an improved understanding of the dynamics of metal(loid) fates and a review of existing management options, new scientific insights are provided for future research in the development of high-performance and sustainable treatment technologies for PTEs in solid wastes.

7.
Stroke ; 50(7): 1887-1890, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31182001

RESUMO

Background and Purpose- Hypoxic-ischemic brain damage is a well-recognized physiopathologic mechanism after aneurysmal subarachnoid hemorrhage (aSAH). The Ngb (neuroglobin) is a hemoprotein predominantly expressed in the brain with a high affinity for oxygen. Relationship between serum Ngb level and brain metabolism in aSAH patients has not been investigated previously. Methods- Thirty-six consecutive severe aSAH patients (Glasgow Coma Scale score ≤8 on admission) with multimodal neuromonitoring and 36 matched healthy subjects were included. Serum Ngb level was analyzed in combination with other time-matched cerebral microdialysis parameters, brain tissue oxygen tension, and 12-month neurological outcomes. Results- Serum Ngb level was correlated positively with cerebral microdialysis parameters and brain tissue oxygen tension ( P<0.001). Poor functional outcome (modified Rankin Scale score >3) 12 months after aSAH was associated with higher Ngb level but independent of age, sex, and disease severity ( P<0.001). A similar association was found between high Ngb level and neuropsychological test results indicative of impairments in cognition, visual conceptualization, and frontal executive functions ( P<0.001). Conclusions- Ngb may be a potential biomarker for reflecting brain tissue oxygen tension, brain metabolism, and functional outcome in severe aSAH patients and merits further study in the context of aSAH.

8.
Neurocrit Care ; 2019 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-31161421

RESUMO

BACKGROUND AND OBJECTIVE: The aim of the study is to investigate the value of serum iron and hemoglobin levels for predicting acute seizures following aneurysmal subarachnoid hemorrhage (aSAH). METHODS: Clinical and laboratorial data from patients with ruptured intracranial aneurysms were collected in the retrospective study. Age, sex, symptom onset, history of diabetes and hypertension, history of coronary artery disease, temperature, Hunt-Hess grade, Fisher grade, aneurysm location, hemoglobin, serum potassium, sodium, calcium, phosphorus, and iron were collected. Acute seizures were determined as seizures within 1 week following aSAH. Propensity score matching (PSM) analyses were performed to correct imbalances in patient characteristics between seizure and non-seizure groups. RESULTS: A total of 760 patients were included. Incidence of acute seizures following aSAH was 6.4%. In the univariate analysis, significant differences were detected in age, admission Hunt-Hess grade, Fisher grade, hemoglobin, serum sodium, and serum iron between seizure and non-seizure groups. In multivariate logistic regression model, lower serum iron was considered as a risk factor for acute seizures (OR 0.182, 95% CI 0.084-0.393, p = 0.000), as well as lower hemoglobin (OR 0.977, 95% CI 0.962-0.993, p = 0.004) and higher serum sodium (OR 1.072, 95% CI 1.003-1.145, p = 0.039). After PSM, there were no significant differences in age, admission Hunt-Hess grade, Fisher grade, and serum sodium between seizure and non-seizure groups. The matched seizure group had lower serum iron and hemoglobin levels compared with the matched non-seizure group (p < 0.05). The optimal cutoff value for serum iron and hemoglobin levels as a predictor of acute seizure after aSAH was determined as 9.9 mmol/L (sensitivity was 81.63% and the specificity was 65.40%) and 119 g/L (sensitivity was 63.27% and the specificity was 70.18%), respectively. CONCLUSIONS: Serum iron and hemoglobin levels were inversely associated with a high risk of acute seizures following aSAH.

9.
Environ Pollut ; 252(Pt B): 1133-1141, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31252111

RESUMO

The efficient removal of mercury from aqueous media remains a severe challenge in ensuring environmental safety, especially for low-concentration mercury, which requires adsorbents with high mercury affinity. In this work, we reported a nanocomposite of ß-cyclodextrin and three-dimensional graphene (3D CD@RGO) to enhance the adsorption affinity and capacity for mercury with low concentrations. Characterization of the nanocomposite revealed that cyclodextrin was well dispersed on the 3D graphene support structure to provide highly exposed hydroxyl groups. Adsorption experiments showed that CD@RGO exhibited different adsorption behaviors for mercury within different concentration ranges of 0.2-4.0 mg/L and 4.0-10.0 mg/L, and the adsorption affinity for the former range (KL = 10.05 L/mg) was 1.5 times higher than that for the latter range (KL = 6.69 L/mg). Moreover, CD@RGO had a high adsorption efficiency of 96.6% with a superb adsorption affinity (172.09 L/g) at Ce = 0.01 mg/L, which is 6.70 and 41.25 times higher than that of RGO and RCD (physical mixture of RGO and cyclodextrin), respectively, indicating a synergistic effect of CD@RGO for mercury adsorption. This enhancement can be attributed to the transformation of the adsorption mechanism from the outer-sphere force of electrostatic interaction in RGO to the inner-sphere surface complexation in CD@RGO.

10.
Environ Sci Technol ; 53(15): 8892-8902, 2019 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-31246435

RESUMO

The dynamic behavior of arsenic (As) species is closely associated with iron mineral dissolution/transformation in the environment. Bacterially induced As(V) desorption from iron oxides may be another important process that facilitates As(V) release from iron oxides without significant reductive dissolution of iron oxides. Under the impact of bacterially induced desorption, As kinetic behavior is controlled by both the microbial reduction of As(V) and the As(III)&As(V) reactions on iron oxide surfaces. However, there is still a lack of quantitative understanding on the coupled kinetics of these processes in complex systems. We developed a quantitative model that integrated the time-dependent microbial reduction of As(V) with nonlinear As(III)&As(V) adsorption/desorption kinetics on iron oxides under the impact of bacterially induced As(V) desorption. We collected and modeled literature data from 11 representative studies, in which microbial reduction reactions occurred with minimal iron oxide dissolution/transformation. Our model highlighted the significance of microbially induced As(V) desorption and time-dependent changes of microbial reduction rates. The model can quantitatively assess the roles and the coupling of individual reactions in controlling the overall reaction rates. It provided a basis for developing comprehensive models for As cycling in the environment by coupling with other chemical, physical, and microbial processes.

11.
J Hazard Mater ; 379: 120811, 2019 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-31254786

RESUMO

The application of green synthesized iron nanoparticles (nFe) for the removal of arsenic (As) from contaminated sites has often been proposed as one of the most promising remediation methods. In this work, TEM analysis showed that As(V) was uniformly adsorbed on the surfaces of nFe, while FTIR analysis confirmed that adsorption was mainly via an FeOAs bond, and XPS analysis indicated that only As(V) was adsorbed. Hence, the removal mechanism proposed for As(V) is based on initially nFe reacting with As(V) to form a monodentate chelating ligand and subsequently a bidentate binuclear complex. The initially high surface area (51.14 m2 g-1) of nFe was decreased by half (26.03 m2 g-1) after As(V) adsorption, where the materials high As(V) adsorption capacity(21.59 mg g-1) was attributed to unique properties derived from the green synthesis. Adsorption isotherm modeling indicated that As(V) adsorption by nFe best fit the Langmuir equation (RL2 = 0.9903), and thus suggested chemisorption was occurring. The adsorption also fitted the pseudo second-order kinetic rate equation well, which confirmed that adsorption was via chemisorption. Overall, the green synthesis of nFe exhibited great application potential for As(V) removal due to high As(V) adsorption capacity and simplicity of synthesis.

12.
Angew Chem Int Ed Engl ; 58(26): 8794-8798, 2019 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-31038831

RESUMO

Localized surface plasmon resonance (LSPR) excitation of noble metal nanoparticles has been shown to accelerate and drive photochemical reactions. Here, LSPR excitation is shown to enhance the electrocatalysis of a fuel-cell-relevant reaction. The electrocatalyst consists of Pdx Ag alloy nanotubes (NTs), which combine the catalytic activity of Pd toward the methanol oxidation reaction (MOR) and the visible-light plasmonic response of Ag. The alloy electrocatalyst exhibits enhanced MOR activity under LSPR excitation with significantly higher current densities and a shift to more positive potentials. The modulation of MOR activity is ascribed primarily to hot holes generated by LSPR excitation of the Pdx Ag NTs.

13.
J Nanosci Nanotechnol ; 19(11): 7131-7138, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31039867

RESUMO

Uranium can be immobilized as nanoscale minerals by biomineralization under aerobic conditions. Current researches on nonreductive biomineralization of U(VI) mainly focus on revealing the mechanisms associated with functional groups and enzymes. However, studies on the effect of initial uranium concentration on the uranium bio-immobilization are relatively rare. This paper researched the immobilization of U(VI) at different concentrations by Bacillus cereus 12-2. Adsorption experiments showed that the adsorption equilibrium was rapidly reached within 10 min when U(VI) concentration was 25 mg/L while over 2 h when U(VI) concentration was 200 mg/L. The biological adsorption capacity improved gradually from 24.68 to 163.17 mg/g (dry weight) as U(VI) concentration increased, but the removal rate of uranium decreased from about 100% to 80%. X-ray diffraction (XRD) showed that nanoscale uramphite ((NH4)(UO2)PO4·3H2O) formation time was 4, 4, 12 and 24 h, respectively when initial U(VI) concentration was 25, 50, 75 and 100 mg/L. No mineral was formed after reaction for 24 h when U(VI) concentration was 200 mg/L. Uramphite had better peaks in spectrum after 50 mg/L U(VI) had interacted with Bacillus cereus 12-2 for 4 h. XRD, SEM (scanning electron microscopy) and TEM (transmission electron microscopy) indicated that a large number of amorphous uranium-containing particles appeared extracellularly after 10 min and nanoscale uramphite formed intracellularly after 4 h when uranium concentration was 50 mg/L. This study showed that the time required for adsorption equilibrium and mineralization by Bacillus cereus 12-2 was shorter when the initial U(VI) concentration was lower within a certain range. This phenomenon could be attributed to the increase of relative content of functional groups and the decrease of cytotoxicity of uranium at low concentrations. This work had certain guiding significance for further understanding the mechanism of uranium biomineralization and the application of Bacillus cereus 12-2 under actual uranium-contaminated environments.

14.
Sci Total Environ ; 677: 556-563, 2019 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-31063897

RESUMO

Uranium in saline lake brine is a nuclear resource that attracts worldwide attention. Relatively low concentrations (about 0.2 mg L-1 to 30 mg L-1) require high affinity for the capture materials. In this paper, magnesium binary layered double hydroxides (MgAl-LDH) and its Fe-induced ternary LDH (MgAlFe-LDH) were synthesized for the extraction of simulated concentrations of U(VI) in the saline lake brine system. Batch experiments have shown that both LDHs have strong affinity towards uranium. MgAl-LDH yielded of stronger affinity in lower U(VI) concentrations (0.2 mg L-1 to 5 mg L-1), while MgAlFe-LDH was at higher U(VI) concentrations (5 mg L-1 to 30 mg L-1). For current uranium extraction, the affinities of MgAl-LDH and MgAlFe-LDH are more than twice the maximum affinity of other LDHs and LDHs-based materials. Therefore, these two LDHs are suitable for U(VI) extraction with different concentration levels in saline lakes. The capture process followed the pseudo-second-order kinetics with fast adsorption speed, and the coexisting cations have little effect on the extraction rate. Research through X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) showed the main adsorption mechanisms are surface complexation and the interlayer carbonate coprecipitation. This work provides a potential method for U(VI) extraction while reusing the waste magnesium resources in saline lake.

15.
J Hazard Mater ; 373: 389-396, 2019 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-30933861

RESUMO

The issue that the residual Cr(VI) in the reduced chromite ore processing residue (rCOPR) is slowly released during deposition has attracted increasing attention. However, the speciation and leaching behaviors of Cr(VI) in rCOPR are still not clear, which is essential for revealing the release mechanism of Cr(VI). In this study, ettringite was determined to be the host phase of Cr(VI) in ferrous sulfate-reduced COPR by scanning electron microscopy (SEM), microfocus X-ray fluorescence spectroscopy (µ-XRF) and aberration-corrected scanning transmission electron microscopy (Cs-STEM). This is because the channel structure of ettringite makes it relatively easy for sulfate to be replaced by chromate with similar structure and thermochemical radius. Furthermore, the investigation on the leaching behavior and mechanism of Cr(VI) in rCOPR eroded by environmental factors showed that carbonates, sulfates and acid can promote the release of Cr(VI). Among them, the erosion effect of HCl on rCOPR is weaker than that of Na2CO3 and Na2SO4 because rCOPR possesses a high buffering reserve of alkalinity. In addition, the erosion of rCOPR by Na2CO3 and Na2SO4 can change Cr(VI) speciation in rCOPR. The results implied that the environmental risk of Cr(VI) release during the deposition of rCOPR should deserve careful assessment.

16.
World Neurosurg ; 127: e1237-e1241, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-31009781

RESUMO

OBJECTIVE: We tested the hypothesis that low hemoglobin levels are associated with acute seizures after aneurysmal subarachnoid hemorrhage (aSAH). METHODS: Patients with ruptured intracranial aneurysms were enrolled in the observational cohort study that prospectively collected age, sex, symptom onset, history of diabetes and hypertension, history of coronary artery disease, temperature, Hunt-Hess grade, Fisher grade, aneurysm location, hemoglobin, hematocrit, serum potassium, sodium, calcium, phosphorus, iron, and modified Rankin Scale. Acute seizures were determined as seizures within 1 week after aSAH. RESULTS: We included 554 patients with requisite data for analysis in the prospective study. Incidence of acute seizures following aSAH was 3.61%. In the univariate analysis, significant differences were detected in admission Hunt-Hess grade, Fisher grade, hemoglobin, and serum iron between epilepsy and nonepilepsy groups. Furthermore, acute seizures were associated with higher modified Rankin Scale score and poor outcome (P = 0.004). Serum hemoglobin levels were 114.30 ± 20.08 g/L in the epilepsy group, which were lower than those in the nonepilepsy group (128.64 ± 17.94 mmol/L, P = 0.001). Serum iron levels were 8.89 ± 5.03 g/L in the epilepsy group, which were also lower than those in the nonepilepsy group (13.71 ± 6.70 mmol/L, P = 0.002). The hemoglobin level was positively correlated with serum iron on admission (ρ = 0.321, P = 0.000). In the multivariate logistic regression model, lower hemoglobin was considered as an independent risk factor of acute seizures (odds ratio 4.286, 95% confidence interval 1.492-12.315, P = 0.007). The optimal cutoff value for hemoglobin level as a predictor for acute epilepsy after aSAH was determined as 119 g/L in the receiver operating characteristic curve (sensitivity was 75.00%, and specificity was 69.48%). CONCLUSIONS: These data support the hypothesis that hemoglobin was inversely associated with acute seizures following aSAH.

17.
Sci Total Environ ; 669: 903-910, 2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-30970457

RESUMO

The interaction among various soil minerals can significantly impact on the environmental geochemical process of contaminants. Therefore, this study investigated the effects of interaction between vermiculite (VER) and manganese dioxide (MnO2) on the migration and transformation of Tl(I). The VER exhibited typical layered structure and MnO2 possessed a flower-like structure with serious reunion phenomenon, while the production of interaction between vermiculite and manganese dioxide, labeled VER-MnO2, illustrated as fish scales evenly spread over a large sheet, suggesting that MnO2 could triumphantly be anchored on the VER and the aggregation of MnO2 was prevented. Compared with the pure MnO2, VER acted as template substrate contributed the higher specific surface area (298.18 m2·g-1) and the oxidation degree of Mn. VER-MnO2 showed the highest fixation capacity (144.29 mg·g-1) than other two materials in the order VER-MnO2 > MnO2 > VER, and there was no risk derived from Mn dissolution. The influence mechanism of VER-MnO2 on Tl(I) migration and transformation lied in immobilization, ion exchange and oxidization. Fixed-bed column immobilization experiments showed that VER-MnO2 could purify drinking water contaminated by Tl (20 µg·L-1) and the effective breakthrough volumes were 900 bed volumes until reaching the maximum limits allowed in drinking water (0.1 µg·L-1). VER-MnO2 excellently catches Tl to prevent groundwater pollution. This study provides a theoretical guidance for environmental fate and restoration of soil heavy metal pollution.

18.
Cell Biol Int ; 43(5): 565-573, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30958604

RESUMO

Heterotopic ossification (HO) is a common disturbing complication of intra-articular fractures. Its prevention and treatment are still difficult as its pathogenesis is unclear. It was reported that PDGFRα+ muscle cells in skeletal muscle may participate in the formation of HO; however, the specific mechanism is still unknown. This study investigated the function of miR-19b-3p in osteogenic differentiation of PDGFRα+ muscle cells. MiR-19b-3p was upregulated during PDGFRα+ muscle cell osteogenic differentiation. The exogenous expression of miR-19b-3p led to an increase in osteogenic marker gene transcription and translation during the osteogenic differentiation of PDGFRα+ muscle cells. Furthermore, both alkaline phosphatase and alizarin red staining increased in miR-19b-3p mimic transfected cells. Over-expression of miR-19b-3p led to the down-regulation of gene of phosphate and tension homology deleted on chromosome ten (PTEN). Additionally, the dual luciferase reporter assay demonstrated that PTEN was a direct target of miR-19b-3p. The increase of osteocalcin, osteopontin, and Runt-related transcription factor 2 protein levels induced by ectopic miR-19b-3p expression could be partially reversed by PTEN over-expression. In conclusion, our results suggested that miR-19b-3p may be a promising target in inhibiting PDGFRα+ muscle cell osteogenic differentiation and treatment of HO.


Assuntos
MicroRNAs/metabolismo , Ossificação Heterotópica/metabolismo , PTEN Fosfo-Hidrolase/metabolismo , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/metabolismo , Diferenciação Celular/fisiologia , Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Regulação para Baixo , Humanos , MicroRNAs/genética , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Ossificação Heterotópica/genética , Ossificação Heterotópica/patologia , Osteocalcina/metabolismo , PTEN Fosfo-Hidrolase/genética , Receptor alfa de Fator de Crescimento Derivado de Plaquetas/genética
19.
Environ Int ; 127: 5-12, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30889398

RESUMO

Nanoparticles of four noble metal doped titanium dioxide (i.e., Pd/TiO2, Ag/TiO2, Pt/TiO2 and Cu/TiO2) were synthesized and investigated for their effectiveness to degrade polybrominated diphenyl ethers (PBDEs) under UV light. All the investigated noble metal additives can greatly enhance the performance of TiO2 to degrade 2,2',4',4'-tetrabromodiphenyl ether (BDE-47). However, the debromination pathways of BDE-47 in Ag/TiO2 and Cu/TiO2 systems are just contrary to those in Pd/TiO2 and Pt/TiO2 systems, and there was an induction period in the former systems but not in the latter systems. The hydrogenation experiment suggests a direct H-atom transfer mechanism in Pd/TiO2 and Pt/TiO2 systems, while in Ag/TiO2 and Cu/TiO2 systems, electron transfer is still the dominant mechanism. Electronic method was applied to explain why BDE-47 exhibit different debromination pathways based on different degradation mechanism. In addition, oxygen was proved to be able to capture both electrons and H atoms, and thus can greatly inhibit the degradation of PBDEs in all investigated systems. Finally, the merit and demerit of each metal doped TiO2 were discussed in detail, including the reactivity, stability and the generation of byproducts. We proposed our study greatly enhance our understanding on the mechanisms of PBDE degradation in various metal doped TiO2 systems.

20.
J Neurosurg ; : 1-11, 2019 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-30717037

RESUMO

OBJECTIVEGlutamate excitotoxicity and neuronal apoptosis are suggested to contribute to early brain injury after subarachnoid hemorrhage (SAH). Annexin A7 (ANXA7) has been shown to regulate glutamate release. However, the role of ANXA7 in early brain injury after SAH has not been illustrated. In this study, we aimed to investigate the effect of ANXA7 knockdown in reducing the severity of early brain injury after SAH, and determine the underlying mechanisms.METHODSEndovascular perforation was performed to induce SAH in male Sprague-Dawley rats. ANXA7-siRNA was administered via intraventricular injection 5 days before SAH induction. Neurological test, evaluation of SAH grade, assessment of blood-brain barrier (BBB) permeability, measurement of brain water content, Western blot, double immunofluorescence staining, TUNEL staining, and enzyme-linked immunosorbent assay (ELISA) were performed at 24 hours of SAH induction.RESULTSANXA7 protein expression increased significantly after SAH induction and was seen mainly in neurons. High expression of ANXA7 was associated with poor neurological status. ANXA7 knockdown dramatically ameliorated early brain injury through alleviating BBB disruption and brain edema. Further investigation of the mechanism showed that inhibiting ANXA7 expression can rescue neuronal apoptosis. In addition, ANXA7 knockdown also significantly reduced glutamate release, which was consistent with a significant increase of Bcl-2 expression and decreases of Bax and cleaved caspase-3 expression.CONCLUSIONSANXA7 can induce neuronal apoptosis by affecting glutamate release in rats with SAH. Downregulating the expression of ANXA7 can significantly attenuate early brain injury after SAH. Future therapy targeting ANXA7 may be a promising new choice.

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