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1.
Food Res Int ; 186: 114394, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38729737

RESUMO

The ability of spices (bay leaf, star anise, and red pepper) and their characteristic phenolic compounds (quercetin, kaempferol, and capsaicin) to inhibit Heterocyclic aromatic amines (HAAs) in roasted beef patties were compared. Density functional theory (DFT) was used to reveal phenolic compounds interacting with HAAs-related intermediates and free radicals to explore possible inhibitory mechanisms for HAAs. 3 % red chili and 0.03 % capsaicin reduced the total HAAs content by 57.09 % and 68.79 %, respectively. DFT demonstrated that this was due to the stronger interaction between capsaicin and the ß-carboline HAAs intermediate (Ebind = -32.95 kcal/mol). The interaction between quercetin and phenylacetaldehyde was found to be the strongest (Ebind = -17.47 kcal/mol). Additionally, DFT indicated that capsaicin reduced the carbonyl content by transferring hydrogen atoms (HAT) to eliminate HO·, HOO·, and carbon-centered alkyl radicals. This study provided a reference for the development of DFT in the control of HAAs.


Assuntos
Aminas , Culinária , Teoria da Densidade Funcional , Compostos Heterocíclicos , Fenóis , Aminas/química , Bovinos , Compostos Heterocíclicos/química , Animais , Fenóis/análise , Capsaicina/química , Capsaicina/farmacologia , Capsaicina/análogos & derivados , Capsicum/química , Escatol/análise , Especiarias/análise , Carne Vermelha/análise , Produtos da Carne/análise , Temperatura Alta , Quercetina/análogos & derivados , Quercetina/análise , Quercetina/farmacologia
2.
Food Chem ; 452: 139608, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38754171

RESUMO

Protein from tiger nut meal (TNP) performance high nutritional value. This study optimized the extraction parameters for TNP (DES-TNP) using deep eutectic solvent, with HBD: HBA = 5:1, Liquid: Solid = 11:1, and the moisture content was 15 %. A comprehensive comparison was conducted with the protein extracted using alkali-soluble acid precipitation (ASAE-TNP). DES-TNP demonstrated significantly higher purity (76.21 ± 2.59 %) than ASAE-TNP (67.48 ± 1.11 %). Density functional theory confirmed the successful synthesis of DES and its strong interaction with TNP. Moreover, DES-TNP and ASAE-TNP were different in structure (microscopic, secondary, and tertiary) and molecular weight distribution. The discrepancy contributed to the different functional properties, DES-TNP exhibiting better solubility, emulsification and foaming properties at pH13 compared to ASAE-TNP. For nutritional properties, DES-TNP and ASAE-TNP exhibited similar amino acid composition and digestibility, but the total amino acid content of DES-TNP was higher. This study presented a novel method for the extraction and comprehensive utilization of TNP.


Assuntos
Álcalis , Solventes Eutéticos Profundos , Valor Nutritivo , Proteínas de Plantas , Solubilidade , Proteínas de Plantas/química , Álcalis/química , Solventes Eutéticos Profundos/química , Nozes/química , Aminoácidos/química , Precipitação Química , Peso Molecular
3.
J Sci Food Agric ; 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38666745

RESUMO

BACKGROUND: Complex phosphates (CP) can improve the physicochemical properties and gelation properties of myofibrillar fibrous protein (MP) in mixed meat products, but an excessive intake of phosphates over a long period of time is harmful to health. The present study investigated the effects of partial or complete substitution of CP with sodium bicarbonate (SB) on the physicochemical properties and gel properties of beef-pork-chicken mixed myofibrillar protein (BPC-MP), aiming to evaluate the feasibility of this method in reducing the amount of phosphate in mixed meat products. RESULTS: Under the optimal substitution conditions, the turbidity of BPC-MP was reduced by 37.8%, the net negative potential was increased by 28.9% and the modulus of elasticity (G') was increased. The tertiary structure indexes of protein (including fluorescence intensity, surface hydrophobicity and active thiol content) were significantly changed, whereas the α-helix and ß-turn angle contents in the secondary structure of protein were significantly increased. In addition, the water retention ability and strength of gel were also improved, which were increased by 20.7% and 42.6%, respectively. The results of scanning electron microscopy showed that the SB substitution group had a more compact and ordered microstructure. CONCLUSION: The results showed that partial substitution of CP with SB reduced the amount of phosphate added to BPC-MP and had a positive effect on the physicochemical and gel properties of BPC-MP. © 2024 Society of Chemical Industry.

4.
Environ Pollut ; 322: 121154, 2023 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-36736562

RESUMO

Air quality has significantly improved in China; however, new challenges emerge when dust weather is combined with haze pollution during spring in northern China. On March 15, 2021, an extremely severe sandstorm occurred in Beijing, with hourly maximum PM10 and PM2.5 concentrations reaching 5267.7 µg m-3 and 963.9 µg m-3, respectively. Continuous sandstorm events usually lead to complicated pollution status in spring. Three pollution types were identified disregarding the time sequence throughout March. The secondary formation type was dominant, with high ratios of PM2.5/PM10 (mean 74%) and PM1/PM2.5 (mean 52%). This suggests that secondary transformations are the primary cause of heavy pollution, even during the dry seasons. Sandstorm type resulted in dramatic PM10 levels, with a noticeable decrease in PM2.5/PM10 levels (27%), although PM2.5 levels remain high. The transitional pollution type was distinguished by an independent increase in PM10 levels, although PM2.5 and PM1 levels differed from the PM10 levels. Throughout March, the sulfur oxidation rate varied considerably, with high levels during most periods (mean 0.52). A strong correlation indicated that relative humidity was the primary variable promoting the formation of secondary sulfate. Sandstorms promote heterogeneous reactions by providing abundant reaction surfaces from mineral particles, therefore aggravating secondary pollution. The sandstorm air mass from the northwest passing through the sand sources of Mongolia carried not only crustal matter but also organic components, such as bioaerosols, resulting in a sharp increase in the organic carbon in PM2.5.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Pequim , Poluentes Atmosféricos/análise , Material Particulado/análise , Monitoramento Ambiental , China , Estações do Ano , Aerossóis/análise
5.
Environ Pollut ; 318: 120846, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36496065

RESUMO

Organic aerosols (OA) are major components of fine particulate matter, yet their formation mechanism remains unclear, especially in polluted environments. In this study, we investigated the diurnal chemical compositions and formation processes of OA in carbonaceous particles during winter in Beijing using aerosol time-of-flight mass spectrometry. We found that 84.5% of the measured carbonaceous particles underwent aging processes, characterized by larger diameter and more secondary species compared to fresh carbonaceous particles, and presented different chemical compositions of OA in the daytime and nighttime. During the day, under high O3 concentrations, organosulfates and oligomers existed in the aged carbonaceous particles, which were mixed with a higher signal of nitrate compared with sulfate. At night, under high relative humidity, distinct spectral signatures of hydroxymethanesulfonate and organic nitrogen compounds, and minor signals of other hydroxyalkylsulfonates and high molecular weight organic compounds were present in the aged carbonaceous particles, which were mixed with a higher signal of sulfate compared with nitrate. Our results indicated that photochemistry contributed to OA formation in the daytime, while aqueous chemistry played an important role in OA formation in the nighttime. The findings can help improve the performance of air quality and climate models on OA simulation.


Assuntos
Poluentes Atmosféricos , Pequim , Poluentes Atmosféricos/análise , Nitratos/análise , Monitoramento Ambiental , Material Particulado/análise , Compostos Orgânicos/análise , Estações do Ano , Aerossóis/análise , Sulfatos/análise , China
6.
Kidney Blood Press Res ; 47(12): 702-710, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36260980

RESUMO

INTRODUCTION: Renal cell carcinoma (RCC) generally has a poor prognosis because of late diagnosis and metastasis. Despite its abundance in RCC cells, the functions of kallikrein-related peptidase 4 (KLK4) in RCC cells remain unknown. The results of this investigation were examined to discover if KLK4 gene silencing influences the development of RCC cells. METHODS: The mRNA levels of KLK4 and the relationship between KLK4 and tumor stage in patients with RCC were analyzed from the GEPIA database. Real-time PCR and Western blotting were used to measure the mRNA and protein levels of KLK4. Cell Counting Kit 8 (CCK-8), colony formation, wound healing, and Transwell assays were used to examine the proliferation, invasion, and migration of RCC cells after KLK4 suppression. Finally, xenograft experiments in a mouse model helped understand the in vivo effects of KLK4 knockdown. RESULTS: Our research found that KLK4 expression was upregulated in the kidney chromophobe (KICH) specimens and cell lines. Moreover, inhibiting KLK4 growth led to a slowdown in RCC cell proliferation and colony formation. Additionally, KLK4 knockdown inhibited migration, invasion, and epithelial-mesenchymal transition (EMT) of RCC cells. AKT and ERK phosphorylation were enhanced with KLK4 silencing. In the nude mouse xenograft cancer model, KLK4 silencing also prevented the expression of Ki-67, CD105, and the growth of tumors. CONCLUSION: KLK4 accelerated KICH progression via the ERK/AKT signaling pathway, providing a novel regulatory mechanism for KICH pathogenesis.


Assuntos
Carcinoma de Células Renais , Calicreínas , Neoplasias Renais , Animais , Humanos , Camundongos , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Transição Epitelial-Mesenquimal , Regulação Neoplásica da Expressão Gênica , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Mensageiro , Transdução de Sinais , Calicreínas/metabolismo
7.
Sci Total Environ ; 838(Pt 1): 155970, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-35588831

RESUMO

During the coronavirus disease 2019 (COVID-19) lockdown in 2020, severe haze pollution occurred in the North China Plain despite the significant reduction in anthropogenic emissions, providing a natural experiment to explore the response of haze pollution to the reduction of human activities. Here, we study the characteristics and causes of haze pollution during the COVID-19 outbreak based on comprehensive field measurements in Beijing during January and February 2020. After excluding the Spring Festival period affected by fireworks activities, we found the ozone concentrations and the proportion of sulfate and nitrate in PM2.5 increased during the COVID-19 lockdown compared with the period before the lockdown, and sulfate played a more important role. Heterogeneous chemistry and photochemistry dominate the formation of sulfate and nitrate during the whole campaign, respectively, and the heterogeneous formation of nitrate at night was enhanced during the lockdown. The coeffects of more reductions in NOx than VOCs, weakened titration of NO, and increased temperature during the lockdown led to the increase in ozone concentrations, thereby promoting atmospheric oxidation capacity and photochemistry. In addition, the increase in relative humidity during the lockdown facilitated heterogeneous chemistry. Our results indicate that unbalanced emission reductions and adverse meteorological conditions induce the formation of secondary pollutants during the COVID-19 lockdown haze, and the formulation of effective coordinated emission-reduction control measures for PM2.5 and ozone pollution is needed in the future, especially the balanced control of NOx and VOCs.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Poluentes Ambientais , Ozônio , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Pequim/epidemiologia , COVID-19/epidemiologia , China/epidemiologia , Controle de Doenças Transmissíveis , Monitoramento Ambiental , Humanos , Nitratos , Ozônio/análise , Material Particulado/análise , Sulfatos
8.
J Oncol ; 2022: 7346460, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35342412

RESUMO

Renal cell carcinoma (RCC) serves as a prevalent malignancy of urinary system and presents severe mortality and increasing incidence. Long noncoding RNAs (lncRNAs) have demonstrated critical roles in RCC development. Here, we were interested in the function of MMP2-AS1 during RCC progression. We observed that MP2-AS1 localized in both nucleus and cytoplasm of RCC cells using fluorescent in situ hybridization (FISH). The cell viability, proliferation, invasion, and migration of RCC cells were reduced by the depletion of MMP2-AS1. The MMP2-AS1 depletion-inhibited viability, proliferation, migration, and invasion of RCC cells were rescued by the overexpression of MMP2 in vitro. Consistently, the tumor growth of RCC cells was repressed by the depletion of MMP2-AS1 in the nude mice, while the overexpression of MMP2 could reverse this effect in vivo. Mechanically, we predicted the potential interaction of miR-34c-5p with both MMP2-AS1 and MMP2. The treatment of miR-34c-5p mimic reduced the luciferase activity of MMP2-AS1 and MMP2 3'UTR. The depletion of MMP2-AS1 enhanced miR-34c-5p expression and the expression of MMP2 was inhibited by miR-34c-5p in RCC cells. The protein levels of MMP2 were downregulated by MMP2-AS1 knockdown, while the inhibitor of miR-34c-5p rescued the expression of MMP2 in the cells. The treatment of miR-34c-5p mimic attenuated the cell viability, proliferation, invasion, and migration of RCC cells, in which MMP2 overexpression restored the phenotypes. MMP2-AS1 depletion-attenuated viability, proliferation, migration, and invasion of RCC cells were reversed by miR-34c-5p inhibitor. We concluded that MMP2-AS1 contributed to progression of renal cell carcinoma by modulating miR-34c-5p/MMP2 axis.

9.
ACS Appl Mater Interfaces ; 14(2): 2860-2870, 2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-34995451

RESUMO

A diesel oxidation catalyst (DOC) is installed upstream of an exhaust after-treatment line to remove CO and hydrocarbons and generate NO2. The catalyst should possess both good oxidation ability and thermal stability because it sits after the engine. We present a novel high-performance DOC with high steam resistance and thermal stability. A selective dissolution method is adopted to modify the surface physicochemical environment of CeO2-SmMn2O5. The X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, Raman, electron paramagnetic resonance, hydrogen temperature-programmed reduction, and temperature-programmed desorption results reveal that surface Sm cations are partially removed with the exposure of more Mn4+ and Ce3+ cations and the presence of active surface oxygen species. This mechanism benefits the oxygen transformation from Ce to Mn and promotes the Ce3+ + Mn4+ ↔ Ce4+ + Mn3+ redox cycle according to the in situ near-ambient pressure X-ray photoelectron spectroscopy and in situ diffuse reflectance infrared Fourier transformation spectroscopy results. Under laboratory-simulated diesel combustion conditions, the catalyst demonstrates excellent low-temperature oxidation catalytic activity (CO and C3H6 conversion: T100 = 250 °C) compared to a Pt-based catalyst (CO and C3H6 conversion: T100 = 310 °C) with a WHSV of 120,000 mL g-1 h-1. Specifically, NO conversion reaches 68% when the temperature is approximately 300 °C.

10.
Chemosphere ; 286(Pt 2): 131807, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34371362

RESUMO

An online field observation was conducted in Zibo, China from September 1, 2018 to February 28, 2019, covering autumn and winter. Within the investigation period, the mean mass concentrations of PM1, PM2.5, and PM10 were 49.3, 86.1, and 136.5 µg m-3, respectively. OA (organic aerosol) was the most dominant species in PM2.5 (39.7 %), followed by NO3- (26.3 %) and SO42- (17.0 %), indicating the importance of secondary species on PM2.5. Increase of particles were always accompanied increasing relative humidity (RH), slow wind, and increasing precursors, contributing the secondary transition. SO42- was more susceptible to RH, indicating the dominant role of heterogeneous processes in its secondary formation. As RH increased, its strengthening effect on SO42- increased as well. Photochemistry was the main contributor to the secondary formation of NO3-. The morning and evening rush hours determined the peak of absolute NO3- throughout the day. By classifying particles into three bins, we found that smaller particles were the biggest contributors (larger PM1/PM2.5) of slight pollution (35 < PM2.5<115 µg m-3). When severe haze occurred, PM2.5 contributed more than particles of other sizes (PM1 or PM10). Secondary species contributed more to particles within 2.5 µm but less to larger particles. PM1/PM2.5 was high from 9:00 to 15:00, indicating the strong effect of photochemistry on smaller particles. In comparison, larger particles favored more humid conditions. NO3- preferentially existed in larger particles because the hygroscopicity of preexisting species (SO42- and NO3-) promoted partitioning. SO42- appeared a stable diurnal variation, replying its stable contribution to particles of different sizes.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , China , Monitoramento Ambiental , Material Particulado/análise , Estações do Ano
11.
J Hazard Mater ; 424(Pt C): 127601, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34763284

RESUMO

Catalytic oxidation is promising in removing atmospheric pollutants to address serious environmental concerns. Supported Pt-based catalysts (e.g., Pt/CeO2) are most effective for catalytic removal of atmospheric pollutants. However, the catalytic performance is largely affected by the oxidation state of Pt, oxygen vacancy and metal-support interaction (MSI). Herein, two different types of Pt/CeO2 catalyst were fabricated via surfactant-assisted strategy and treated in different annealing atmospheres, which was applied to carbon monoxide (CO) and toluene (C7H8) oxidation, respectively. The results reveal that the as-synthesized Pt/CeO2-NH catalyst is favorable to C7H8 oxidation, whereas the contrast Pt/CeO2-AH is favorable to CO oxidation. Meanwhile, Pt/CeO2-NH catalyst also has high thermal stability facing high temperature (e.g., 400 °C). Various characterizations, such as in-situ Raman, XPS, CO-DRIFTS and XANES, clarifies that the Pt/CeO2-NH catalyst has a higher surface Pt0 proportion, a weak MSI and more oxygen vacancies. The corresponding theoretical calculation also supports the experimental results. These results advance efficient regulation and fundamental understanding of MSI, and the design of heterogeneous catalysts.

12.
J Food Sci ; 86(10): 4611-4627, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34533217

RESUMO

The purpose of this study is to develop a green and safe chitosan-based preservative which can be applied in strawberry preservation. Chitosan (CS) was treated by 2,2,6,6-tetramethylpiperidine oxygen radical/laccase oxidation system (TEMPO/laccase oxidation system), which was mainly used to prepare TEMPO/laccase chitosan (TLCS). Furthermore, on this basis, the structure and performance of TLCS were also studied. The results showed that compared with CS, the solubility of TLCS improved, and the kinetic viscosity reduced significantly. Next, a cinnamaldehyde-TEMPO/laccase chitosan (CIN-TLCS) antibacterial agent was prepared by covalently combining the aldehyde group in cinnamaldehyde (CIN) and the amino group in CS. It was found that CIN combined with TLCS through covalent bonds, which changed the structure and crystallinity of TLCS. In addition, the total antioxidant capacity of CIN-TLCS also improved, which was necessary for the application of CIN-TLCS in extending shelf life. Cytotoxicity experiments showed that CIN-TLCS had no cytotoxicity. Furthermore, strawberries were used to explore the actual bacteriostatic and fresh-keeping effects of CIN-TLCS. The experiment found that CIN-TLCS could maintain the freshness of strawberries at room temperature (23 ± 1°C) for 5 days and had positive effects on strawberry color, loss-weight rate, hardness and pH. These results showed that CIN-TLCS could be used as a potential preserving agent for fruit storage. PRACTICAL APPLICATION: To obtain a green, safe and effective food preservative, chitosan (CS) was modified by a 2,2,6,6-tetramethylpiperidine oxygen radical/laccase oxidation system (TEMPO/laccase oxidation system) to get TEMPO/laccase chitosan (TLCS) and cinnamic aldehyde-TEMPO/laccase chitosan (CIN-TLCS). At the same time, the structure and antibacterial properties of TLCS and CIN-TLCS were analyzed, and their possibility as a new green and safe strawberry preservative was studied. Compared with oxazolidine, imidazole and triazole commercial drugs, CIN-TLCS has the advantages of low price, no pollution, no cytotoxicity and no drug resistance.


Assuntos
Quitosana , Conservação de Alimentos , Fragaria , Frutas , Quitosana/química , Conservação de Alimentos/métodos
13.
Chemosphere ; 282: 131041, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34090003

RESUMO

The surface sediment concentrations of heavy metals (Cu, Zn, Pb, Cd, Cr, Hg, and As), major metals (Fe and Mn), and the nutrient concentrations in the interstitial water of Lake Houguan, a large eutrophic shallow lake, were surveyed for three years. The results showed that Cu, Zn, and Fe were significantly higher in the east lake parts, and Cd in November was significantly higher than April. 19% of Hg and all of As were larger than the probable effect concentrations (PECs) according to the consensus-based sediment quality guidelines (SQGs), and the geo-accumulation index (Igeo) indicated As, Hg, and Cd were slightly polluted to severely polluted. The RI value (average 704.2) of the potential ecological risk index (PERI) suggested that heavy metals posed very high ecological risks with most of the contributions induced by Cd and Hg. The consequence of hierarchical clustering analysis (HCA) and principle component analysis (PCA) identified Cd, As, and Pb might originate from urbanization, industrial pollution, and agricultural activity; Hg might be from atmospheric deposition and anthropogenic sources above; Cu, Zn, Cr, Fe, and Mn might be from both natural and anthropogenic sources. The Spearman correlation analysis indicated Pb and As were significantly positively correlated with total nitrogen, while Cd significantly negatively correlated with sulfate; As was significantly correlated with ammonia, sulfate, and nitrate in the interstitial water. These results suggested eutrophication might affect sedimental heavy metals by increasing organic matter or influencing the redox potentials in the sediment.


Assuntos
Metais Pesados , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Lagos , Metais Pesados/análise , Nutrientes , Medição de Risco , Poluentes Químicos da Água/análise
14.
Environ Pollut ; 279: 116923, 2021 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-33751950

RESUMO

To control the spread of COVID-19, China implemented a series of lockdowns, limiting various offline interactions. This provided an opportunity to study the response of air quality to emissions control. By comparing the characteristics of pollution in the summers of 2019 and 2020, we found a significant decrease in gaseous pollutants in 2020. However, particle pollution in the summer of 2020 was more severe; PM2.5 levels increased from 35.8 to 44.7 µg m-3, and PM10 increased from 51.4 to 69.0 µg m-3 from 2019 to 2020. The higher PM10 was caused by two sandstorm events on May 11 and June 3, 2020, while the higher PM2.5 was the result of enhanced secondary formation processes indicated by the higher sulfate oxidation rate (SOR) and nitrate oxidation rate (NOR) in 2020. Higher SOR and NOR were attributed mainly to higher relative humidity and stronger oxidizing capacity. Analysis of PMx distribution showed that severe haze occurred when particles within Bin2 (size ranging 1-2.5 µm) dominated. SO42-(1/2.5) and SO42-(2.5/10) remained stable under different periods at 0.5 and 0.8, respectively, indicating that SO42- existed mainly in smaller particles. Decreases in NO3-(1/2.5) and increases in NO3-(2.5/10) from clean to polluted conditions, similar to the variations in PMx distribution, suggest that NO3- played a role in the worsening of pollution. O3 concentrations were higher in 2020 (108.6 µg m-3) than in 2019 (96.8 µg m-3). Marked decreases in fresh NO alleviated the titration of O3. Furthermore, the oxidation reaction of NO2 that produces NO3- was dominant over the photochemical reaction of NO2 that produces O3, making NO2 less important for O3 pollution. In comparison, a lower VOC/NOx ratio (less than 10) meant that Beijing is a VOC-limited area; this indicates that in order to alleviate O3 pollution in Beijing, emissions of VOCs should be controlled.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , COVID-19 , Aerossóis/análise , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Pequim , China , Controle de Doenças Transmissíveis , Monitoramento Ambiental , Gases , Humanos , Material Particulado/análise , SARS-CoV-2 , Estações do Ano
15.
J Environ Sci (China) ; 103: 207-218, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33743903

RESUMO

Accelerating the (NH4)2SO3 oxidation gives rise to the reclaiming of byproduct, while there are secondary environmental risks from reduction of the coexisted selenium species by sulfite. In this study, a bi-functional Co-SBA-15-SH, were synthesized through Co impregnation and sulfhydryl (-SH) decoration, which can simultaneously uptake Se and accelerate sulfite oxidation efficiently. Meanwhile, the adsorption kinetics and migration mechanism of Se species were revealed through characterization and density functional calculations, with maximum adsorption capacity of 223 mg/g. The inhibition of Se0 re-emission and poisonous effect of Se on sulfite oxidation was also investigated. Using the findings of this study, the ammonia desulfurization can be improved by enabling purification of the byproduct and lowering the toxicity of effluent by removing toxic pollutants.


Assuntos
Amônia , Selênio , Catálise , Oxirredução , Sulfitos
16.
Ann Palliat Med ; 10(1): 584-589, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33474959

RESUMO

BACKGROUND: Renal cell carcinoma (RCC) is the most common type of kidney cancer, and accounts for approximately 3% of all malignancies. Metastatic RCC (mRCC) is not sensitive to traditional radiotherapy and chemotherapy, therefore targeted therapy has become an important treatment option. In this study, the second-line targeted drug everolimus (Afinitor), a mammalian target of rapamycin (mTOR) inhibitor, was investigated for its clinical efficacy and adverse events in mRCC after failure of first-line targeted therapy, such as sorafenib, sunitinib or pazopanib. METHODS: A total of 21 patients with mRCC who had been treated with surgery or other therapies such as tyrosine kinase inhibitors (TKIs) were given oral everolimus (10 mg/day) until disease progression. Clinical efficacy was evaluated using the Response Evaluation Criteria in Solid Tumors (RECIST) 2 months after therapy, including complete response (CR), partial response (PR), stable disease (SD), and progressive disease (PD). The adverse events were observed, and timely treatment was provided. RESULTS: Everolimus extended progression-free survival (PFS) in mRCC patients from 4 to 8 months (median 6.3 months). There were 3 patients with PR, 12 with SD, and 6 with PD, and the disease control rate (DCR) was 15/21 (71.4%). Common adverse events included stomatitis, rash, and pneumonitis. CONCLUSIONS: This study provides further support that everolimus is still an important option in mRCC treatment after failure of first-line targeted therapy. However, clinical studies are still needed to further improve its therapeutic efficacy.


Assuntos
Antineoplásicos , Carcinoma de Células Renais , Neoplasias Renais , Antineoplásicos/efeitos adversos , Carcinoma de Células Renais/tratamento farmacológico , Everolimo/efeitos adversos , Humanos , Neoplasias Renais/tratamento farmacológico , Sirolimo/efeitos adversos , Resultado do Tratamento
17.
J Hazard Mater ; 403: 123811, 2021 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-33264910

RESUMO

The elimination of benzene, a typical volatile organic pollutant, is one of the most challenging topics for environmental scientists. Catalytic oxidation technology is considered the most efficient approach for its elimination. Herein, we report the successful preparation of a novel α-MnO2-like rod catalyst via an acid etching route and propose YMn2O5 mullite as a novel precursor. The optimized α-MnO2-like rod catalyst showed significantly improved benzene oxidation activity compared to the raw YMn2O5 and commercial MnO2 catalysts, resulting in 100 % benzene conversion at 200 °C at a GHSV of 60,000 mL g-1 h-1. Notably, the α-MnO2-like rod catalyst performance at lower temperatures (100-175 ℃) exceeded that of a commercial Pt/Al2O3 catalyst. The excellent catalytic performance of the α-MnO2-like rod catalyst is associated with its low-temperature reducibility and abundant surface-active oxygen species. During the acid etching process, more Mn3+ is oxidized to Mn4+, and more surface oxygen vacancies are generated on the α-MnO2-like rod catalyst, which provides more adsorption sites for oxygen molecules to promote the benzene oxidation reaction. The α-MnO2-like rod catalyst should be a great alternative to commercial noble metal catalysts for the elimination of volatile organic pollutants, especially at lower temperatures.

18.
Phys Rev Lett ; 125(14): 142501, 2020 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-33064499

RESUMO

The recent RIKEN experiment on the quenched g_{A} in the superallowed Gamow-Teller transition from ^{100}Sn indicates the role of scale anomaly encoded in the anomalous dimension ß^{'} of the gluonic stress tensor Tr G_{µν}^{2}. This observation provides support to the notion of hidden scale symmetry emerging by strong nuclear correlations with an infrared (IR) fixed point realized-in the chiral limit-in the Nambu-Goldstone mode. We suggest there is an analogy in the way scale symmetry manifests in a nuclear medium to the continuity from the unitarity limit at low density (in light nuclei) to the dilaton limit at high density (in compact stars). In between the limits, say, at normal nuclear matter density, the symmetry is not visible, hence hidden.

19.
Sci Total Environ ; 746: 141209, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32763608

RESUMO

Organic aerosols (OA) undergo sophisticated physiochemical processes in the atmosphere, playing a crucial role in extreme haze formations over the Northern China Plain. However, current understandings of the detailed composition and formation pathways are limited. In this study, high-molecular weight (HMW) species were observed in samples collected year-round in urban Beijing, especially in autumn and winter, during 2016-2017. The positive-ion-mode mass spectra of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF-MS) showed that higher signal intensities were obtained in the mass-to-charge (m/z) ranges of 200-500 and 800-900, with repetitive mass difference patterns of m/z 12, 14, 16, and 18. This provided sound evidence that high-molecular-weight oligomers were generated as haze episodes became exacerbated. These oligomer signal intensities were enhanced in the presence of high relative humidity, aerosol water content, and PM2.5 (particles with an aerodynamic diameter ≤ 2.5 µm) mass, proving that the multiphase reaction processes play a fundamental role in haze formation in Beijing. Our study can form a basis for improved air pollution mitigation measures aimed at OA to improve health outcomes.

20.
Pathol Oncol Res ; 26(2): 1201-1209, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31190217

RESUMO

To assess the associations between O6-methylguanine-DNA methyltransferase(MGMT) polymorphisms and prostate cancer risk. We retrieved PubMed, Cochrane Library and Embase electronic database to search for all eligible studies published from Jan 1, 1970 to Sep 31, 2017 to conduct a Meta-analysis. we identified 11 independent studies in 5 eligible reports, including 5143 cases and 8118 controls. The data suggested that rs12917 was associated with higher PCa risk under the contrast of TT vs CC and recessive model in overall population (TT vs CC: OR = 1.599, 95%CI: 1.007-2.539, P = 0.047; TT vs CC + CT: OR = 1.627, 95%CI: 1.026-2.580, P = 0.038). In subgroup analyses stratified by ethnicity, the remarkable association with higher PCa risk was detected under allelic model, dominant model, the contrast of TC vs CC, and the contrast of TC vs CC + TT in Asian population. (T vs C: OR = 1.911, 95%CI: 1.182-3.090, P = 0.008; TC vs CC: OR = 1.948, 95%CI: 1.152-3.295, P = 0.013; TC + TT vs CC: OR = 1.994, 95%CI: 1.190-3.342, P = 0.009; TC vs CC + TT: OR = 1.926, 95%CI: 1.140-3.255, P = 0.014). However, the data suggest the rs2308327 and rs2308321 polymorphisms of the MGMT gene were nor associated with the susceptibility of prostate cancer. Based on the meta-analysis, MGMT rs12917 polymorphism increase the susceptibility to prostate cancer, which can be taken for a diagnosis and screening molecular biomarker for prostate cancer patients.


Assuntos
Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Predisposição Genética para Doença/genética , Neoplasias da Próstata/genética , Proteínas Supressoras de Tumor/genética , Humanos , Masculino , Polimorfismo de Nucleotídeo Único/genética
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