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1.
J Environ Sci (China) ; 145: 205-215, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38844320

RESUMEN

Thermal treatment can effectively decontaminate soils but alter their properties. Previous research mainly focused on volatile organic compounds and metals, i.e. Hg, neglecting non-volatile metal(loid)s. This study aimed to investigate Cd and As transformation during aerobic and anaerobic calcination. The results showed that both aerobic and anaerobic calcination increased soil pH by reducing soil organic matter (SOM) content, which also influenced the cation exchange capacity (CEC) and the leaching behavior of Cd and As in the soil. The total concentrations of Cd and As in the calcined soils varied depending on the calcination temperature and atmosphere. When the aerobic calcination temperature exceeded 700 °C, Cd volatilized as CdCl2, while anaerobic calcination at relatively low temperatures (600 °C) involved reductive reactions, resulting in the formation of metallic Cd with a lower boiling point. Similarly, As volatilized at 800 °C aerobically and 600 °C anaerobically. The formation of As-based minerals, particularly Ca3(AsO4)2, hindered its gasification, whereas anaerobic calcination promoted volatilization efficiency through the generation of C-As(III) based gaseous components with lower boiling points. Contrasting trends were observed in the TCLP-extractable Cd and As contents of the calcined soils. Over 70% of TCLP-extractable Cd contents were suppressed after thermal treatment, attributed to the elevated pH and reduced CEC of the soil, as well as volatilization. However, TCLP-extractable As contents increased with elevated temperatures, likely due to the desorption of AsO43- and re-adsorption of gaseous As2O3 during cooling. These findings have implications for assessing the environmental impact of thermal treatment and provide insights for remediation strategies concerning Cd and As-contaminated soils.


Asunto(s)
Arsénico , Cadmio , Contaminantes del Suelo , Suelo , Cadmio/química , Cadmio/análisis , Contaminantes del Suelo/análisis , Contaminantes del Suelo/química , Arsénico/análisis , Arsénico/química , Suelo/química , Restauración y Remediación Ambiental/métodos , Calor
2.
J Environ Sci (China) ; 142: 226-235, 2024 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-38527888

RESUMEN

In North China, iodine-rich groundwater has been extensively studied, but few in South China. This study aimed to investigate the characteristics of iodine-rich groundwater in South China and identify potential contamination sources. The results revealed that the average concentration of iodine in groundwater was 890 µg/L, with a maximum concentration of 6350 µg/L, exceeding the permitted levels recommended by the World Health Organization (5-300 µg/L). Notably, the enrichment of iodide occurred in acidic conditions (pH = 6.6) and a relatively low Eh environment (Eh = 198.4 mV). Pearson correlation and cluster analyses suggested that the enrichment of iodide could be attributed to the intensified redox process involving Mn(II), iodine (I2), or iodate (IO3-) in the soil. The strong affinity between Mn(II) and I2/IO3- facilitated their interaction, resulting in the formation and mobilization of I- from the soil to the groundwater. Leaching experiments further confirmed that reducing substances (such as sodium sulfides, ascorbic acids, and fulvic acids) in the soil with low dissolved oxygen (DO) levels (< 1.0 mg/L) enhanced the dissolution of iodine species. Conversely, higher DO content (> 3.8 mg/L) promoted the oxidation of I- into I2 or IO3-, leading to its stabilization. This research provides new insights into the characteristics and mechanisms of I- enrichment in groundwater in South China, and emphasizes the significance of the redox reactions involving Mn(II) and I2/IO3-, as well as the influence of soil properties in regulating the occurrence and transportation of iodine species within groundwater systems.


Asunto(s)
Agua Subterránea , Yodo , Contaminantes Químicos del Agua , Yodo/análisis , Yoduros/análisis , Agua Subterránea/química , Suelo , China , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente
4.
Chemosphere ; 338: 139573, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37474037

RESUMEN

In the Pearl River Delta of China, many sites are likely contaminated with aniline in the soil and arsenic (As) in the groundwater because of a high As background level and the prevailing printing and dyeing industry. This study is to explore the remediation performance of thermally activated persulfate oxidation for the sites with these two contaminants, aniline and As. The As influence on the aniline degradation and vice versa are also systematically investigated. When the molar ratio of aniline to persulfate is 1: 4.65, over 85% of aniline can be degraded at 40 °C in 24 h, and 100 µg L-1 As(III) in solution can be completely adsorbed by the soil. A higher pH favored the aniline degradation but disfavored the As(III) oxidation. Due to the strong buffer capacity of the soil, aniline in the soil could be more quickly degraded than those in the solution. The As(III), however, seem more easily oxidized in the absence of soil. The coexisting Fe2+ can substantially improve As(III) oxidation and immobilization, although the dilute Fe2+ solution may suppress the aniline degradation. The presence of aniline severely inhibited the As(III) oxidation and adsorption, likely due to the competition for the generated free radicals and the adsorption sites on the soils. In contrast, the existing As(III) has a slight effect on aniline degradation. These findings are believed to provide the theoretical basis for the remediation of aniline-arsenic contaminated sites.


Asunto(s)
Arsénico , Sulfatos , Suelo , Oxidación-Reducción , Compuestos de Anilina
5.
Environ Sci Technol ; 57(8): 3357-3368, 2023 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-36790364

RESUMEN

To cope with the urgent and unprecedented demands for rare earth elements (REEs) in sophisticated industries, increased attention has been paid to REE recovery from recycled streams. However, the similar geochemical behaviors of REEs and transition metals often result in poor separation performance due to nonselectivity. Here, a unique approach based on the selective transformation between ceria sulfation and iron/manganese mineralization was proposed, leading to the enhancement of the selective separation of REEs. The mechanism of the selective transformation of minerals could be ascribed to the distinct geochemical and metallurgical properties of ions, resulting in different combinations of cations and anions. According to hard-soft acid-base (HSAB) theory, the strong Lewis acid of Ce(III) was inclined to combine with the hard base of sulfates (SO42-), while the borderline acid of Fe(II)/Mn(II) prefers to interact with oxygen ions (O2-). Both in situ characterization and density functional theory (DFT) calculation further revealed that such selective transformation might trigger by the generation of an oxygen vacancy on the surface of CeO2, leading to the formation of Ce2(SO4)3 and Fe/Mn spinel. Although the electron density difference of the configurations (CeO2-x-SO4, Fe2O3-x-SO4, and MnO2-x-SO4) shared a similar direction of the electron transfer from the metals to the sulfate-based oxygen, the higher electron depletion of Ce (QCe = -1.91 e) than Fe (QFe = -1.66 e) and Mn (QMn = -1.64 e) indicated the higher stability in the Ce-O-S complex, resulting in the larger adsorption energy of CeO2-x-SO4 (-6.88 eV) compared with Fe2O3-x-SO4 (-3.10 eV) and MnO2-x-SO4 (-2.49 eV). This research provided new insights into the selective transformation of REEs and transition metals in pyrometallurgy and thus offered a new approach for the selective recovery of REEs from secondary resources.


Asunto(s)
Metales de Tierras Raras , Elementos de Transición , Manganeso , Hierro , Adsorción , Sulfatos
6.
Front Oncol ; 12: 1091782, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36605439

RESUMEN

Immune evasion through up-regulating checkpoint inhibitory receptors on T cells plays an essential role in tumor initiation and progression. Therefore, immunotherapy, including immune checkpoint inhibitor targeting programmed cell death protein 1 (PD-1) and chimeric antigen receptor T cell (CAR-T) therapy, has become a promising strategy for hematological malignancies. T cell immunoreceptor with immunoglobulin and ITIM domain (TIGIT) is a novel checkpoint inhibitory receptor expressed on immune cells, including cytotoxic T cells, regulatory T cells, and NK cells. TIGIT participates in immune regulation via binding to its ligand CD155. Blockage of TIGIT has provided evidence of considerable efficacy in solid tumors in preclinical research and clinical trials, especially when combined with PD-1 inhibition. However, the mechanism and function of TIGIT in hematological malignancies have not been comprehensively studied. In this review, we focus on the role of TIGIT in hematological malignancies and discuss therapeutic strategies targeting TIGIT, which may provide a promising immunotherapy target for hematological malignancies.

7.
Environ Sci Technol ; 2021 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-34310116

RESUMEN

The increasing demand for rare earth elements (REEs) motivates the development of novel strategies for cost-effective REE recovery from secondary sources, especially rare earth tailings. The biggest challenges in recovering REEs from ion-adsorption rare earth tailings are incomplete extraction of cerium (Ce) and the coleaching of iron (Fe) and manganese (Mn). Here, a synergistic process between reduction and stabilization was proposed by innovatively using elemental sulfur (S) as reductant for converting insoluble CeO2 into soluble Ce2(SO4)3 and transforming Fe and Mn oxides into inert FeFe2O4 and MnFe2O4 spinel minerals. After the calcination at 400 °C, 97.0% of Ce can be dissolved using a diluted sulfuric acid, along with only 3.67% of Fe and 23.3% of Mn leached out. Thermodynamic analysis reveals that CeO2 was indirectly reduced by the intermediates MnSO4 and FeS in the system. Density functional theory calculations indicated that Fe(II) and Mn(II) shared similar outer electron arrangements and coordination environments, favoring Mn(II) over Ce(III) as a replacement for Fe(II) in the FeO6 octahedral structure of FeFe2O4. Further investigation on the leaching process suggested that 0.5 mol L-1 H2SO4 is sufficient for the recovery of REEs (97.0%). This research provides a promising strategy to selectively recover REEs from mining tailings or secondary sources via controlling the mineral phase transformation.

8.
World J Clin Cases ; 8(22): 5618-5624, 2020 Nov 26.
Artículo en Inglés | MEDLINE | ID: mdl-33344552

RESUMEN

BACKGROUND: Primary myelofibrosis (PMF) is a myeloproliferative neoplasm (MPN) characterized by recurrent mutations in the JAK2, CALR, and MPL genes. The CALR and MPL co-mutation is very rare. To our knowledge, no more than five cases have been reported. Here, we report a case of PMF in which a CALR and MPL co-mutation was detected by next-generation sequencing (NGS) technology, and a literature review was performed. CASE SUMMARY: A 73-year-old woman was admitted to our hospital in 2018 due to abdominal distension. The patient had splenomegaly, lymphadenopathy, leukopenia, anemia, and immature granulocytes in peripheral blood. There were dacrocytes and atypical megakaryocytes in bone marrow, and megakaryocytic proliferation was very active, accompanied by reticulin fibrosis grade 2. By NGS analysis of the bone marrow sample, we detected mutations in CALR, MPL, and PIK3RI, while JAK2 V617F and BCR-ABL were negative. Therefore, the patient was diagnosed with PMF and received oral ruxolitinib. However, the spleen and hematologic responses were poor. We review the literature, analyze previous reports of the mutation sites in our patient and differences between our patient and other reported cases of co-mutated CALR and MPL genes, and discuss the reason why the CALR and MPL co-mutations are rare and possible mechanisms and their impact on the prognosis of patients. CONCLUSION: CALR and MPL mutations can be concurrent in MPN, but they are rare. The use of NGS may help to identify more patients with co-mutated CALR and MPL genes. This will help to further explore the mechanism and its impact on these patients to develop appropriate treatment strategies.

9.
Chemosphere ; 221: 563-572, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-30677726

RESUMEN

Nickel (Ⅱ)-ethylenediaminetetraacetic acid (Ni-EDTA) complexes are widely present in electroplating effluents. Owing to its chemical stability, Ni-EDTA is hardly removed in traditional Fenton/Fenton-like processes with conventional iron (Fe)-based catalyst. In this study, oxygen vacancies were introduced into our highly efficient and novel Fe3O4@γ-Al2O3 catalysts using Cu doping for Ni-EDTA decomposition in Fenton-like system. Without noble-metal cocatalyst, the introduction of oxygen vacancies in Cu-doped Fe3O4@γ-Al2O3 catalysts exhibit excellent Fenton-like activity even in neutral or alkaline conditions. Experimental results revealed that, without the aid of extra energy, Ni-EDTA complexes could be effectively decomposed over oxygen vacancies-based catalyst. Electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), oxygen temperature-programmed desorption (O2-TPD), and hydrogen temperature-programmed reduction (H2-TPR) were used to get a deep insight into the decomposition mechanism. Additionally, by employing the Al-containing support, stable layered double-hydroxide phases of NiAl could be formed, indicating that a synergy of oxidation and adsorption could simultaneously take place, which led to the recovery of released Ni2+ ions and also reduction in secondary pollution. To investigate the decomposition process of Ni-EDTA over oxygen vacancies-based catalyst, liquid chromatography-quadrupole/electrostatic field orbitrap high resolution mass spectrometry (LC-MS/MS) was employed to identify the generated intermediates, and thus, a plausible decomposition pathway was successfully conceived.


Asunto(s)
Ácido Edético/química , Galvanoplastia , Restauración y Remediación Ambiental/métodos , Níquel/química , Adsorción , Óxido de Aluminio/química , Catálisis , Cobre , Compuestos Férricos , Peróxido de Hidrógeno/química , Oxidación-Reducción , Oxígeno/química
10.
Ecotoxicol Environ Saf ; 172: 26-32, 2019 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-30669071

RESUMEN

Enhancing industrial sludge detoxification is of scientific and practical significance in confronting urban development and stringent environmental regulations. A strategy combining ultrasound (US) with the zero-valent iron/EDTA/Air (ZEA) process was proven to be eco-friendly, being efficient in the removal of toxic compounds from textile dyeing sludge in our previous studies. In this paper, therefore, the detoxification effects of three advanced oxidation processes (US, ZEA, US/ZEA) on textile dyeing sludge were comparatively evaluated for the first time through alteration of the sludge's physico-chemical parameters (e.g., macronutrients, heavy metals, and persistent organic pollutants) and toxicity (plants and aquatic biota), by which the appropriateness of industrial sludge's agricultural use was assessed. The results showed that US led to the least alteration of the physico-chemical properties, and the treated sludge became less biodegradable, as demonstrated by XPS. With ZEA treatment, persistent organic pollutants (POPs) were degraded by oxidation, and heavy metals were more leachable, leading to effective detoxification with a relatively low sludge dose, but an excessive amount of EDTA would negatively change the fertilizing properties of the sludge. However, the integration of US and ZEA could avoid this situation, as US promoted the degradation of EDTA and POPs, thus causing the least inhibition or even a noticeable stimulation of plant growth when the sludge dosage was 7.5 tdw/ha (recommended dosage by the latest legislation in China). Aquatic organism toxicity tests further confirmed that US/ZEA treatment realized the most significant toxicity reduction, leading to the slightest environmental disruption. This study could be instructive in providing guidance for industrial sludge management considering agricultural use.


Asunto(s)
Residuos Industriales , Aguas del Alcantarillado/química , Textiles , Purificación del Agua/métodos , Agricultura/métodos , China , Contaminantes Ambientales/análisis , Contaminantes Ambientales/toxicidad , Metales Pesados/análisis , Metales Pesados/toxicidad , Reciclaje/métodos , Pruebas de Toxicidad , Ondas Ultrasónicas , Contaminantes Químicos del Agua/análisis , Contaminantes Químicos del Agua/toxicidad
11.
J Hazard Mater ; 358: 441-449, 2018 09 15.
Artículo en Inglés | MEDLINE | ID: mdl-30029142

RESUMEN

To cope with the increasing environmental issues of red mud, an integrated technological route for its comprehensive utilization was developed through the extraction of valuable components and the synthesis of magnetic 4A-zeolite. To accelerate the crystallization process of the synthesized 4A-zeolite, sodium chloride (NaCl) was innovatively employed under hydrothermal treatment. The effects of various parameters, including mass ratio of red mud/NaOH, alkali fusion temperature, alkali fusion time and molar ratio of NaCl/Al2O3, were systematically investigated. The results showed that approximately 81.0% Al, 76.1% Si and 95.8% Fe were utilized from red mud using alkali fusion and acid leaching methods. The optimal conditions of the alkali fusion process were determined as: mass ratio of red mud/NaOH = 1/2, alkali fusion temperature of 800 °C, and time of 90 min. Furthermore, when the molar ratio of NaCl/Al2O3 was kept at 1.5, the crystallization time reduced from 240 min to 150 min, and particle size distributions narrowed from 20-100 µm to 1-10 µm. The practical applications in removal of mixed heavy metal ions (Zn2+, Cu2+, Cd2+, Ni2+, and Pb2+) from wastewater indicated that the as-synthesized magnetic 4A-zeolite is a promising candidate for heavy metals adsorption.

12.
Oncol Rep ; 39(6): 2951-2959, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-29658600

RESUMEN

Phosphoinositide­dependent kinase 1 (PDK1) is generally active in multiple myeloma (MM) and higher expression than other hematopoietic cells, which is associated with the drug resistance and the disease progression. Previous studies have demonstrated that PDK1 can be targeted therapeutically in MM. In the present study, we examined the combination effect of GSK2334470 (GSK­470), a novel and highly specific inhibitor of PDK1, with proteasome inhibitor MG­132 in MM cell lines. GSK­470 monotherapy significantly inhibited growth of MM cell lines and induced apoptosis that was associated with the activation of both the intrinsic mitochondrial pathway and the extrinsic death receptor pathway. Moreover, GSK­470 demonstrated synergistic growth inhibitory effects with MG­132. Notably, treatment with these inhibitors resulted in an almost complete inhibition of phosphorylation of mammalian target of rapamycin on Ser2448 and Ser2481 and full activation of AKT. The combination therapy also caused an upregulation of PTEN and an increased nuclear accumulation of PTEN protein. Collectively, our results provide the rationale for novel combination treatment with PDK1 inhibitor and proteasome inhibitors to improve outcomes in patients with MM.


Asunto(s)
Núcleo Celular/metabolismo , Indazoles/farmacología , Leupeptinas/farmacología , Mieloma Múltiple/metabolismo , Fosfohidrolasa PTEN/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pirimidinas/farmacología , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Sinergismo Farmacológico , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Humanos , Mieloma Múltiple/tratamiento farmacológico , Fosforilación/efectos de los fármacos , Serina-Treonina Quinasas TOR/metabolismo
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