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Converting carbon dioxide (CO2) into fuel and high-value-added chemicals is considered a green and effective way to solve global energy and environmental problems. Covalent triazine frameworks (CTFs) are extensively utilized as an emerging catalyst for photo/electrocatalytic CO2 reduction reaction (CO2RR) recently recognized for their distinctive qualities, including excellent thermal and chemical stability, π-conjugated structure, rich nitrogen content, and a strong affinity for CO2, etc. Nevertheless, single-component CTFs have the problems of accelerated recombination of photoexcited electron-hole pairs and restricted conductivity, which limit their application for photo/electrocatalytic CO2RR. Therefore, emphasis will then summarize the strategies for enhancing the photocatalytic and electrocatalytic efficiency of CTFs for CO2RR in this paper, including atom doping, constructing a heterojunction structure, etc. This review first illustrates the synthesis strategies of CTFs and the advantages of CTFs in the field of photo/electrocatalytic CO2RR. Subsequently, the mechanism of CTF-based materials in photo/electrocatalytic CO2RR is described. Lastly, the challenges and future prospects of CTFs in photo/electrocatalytic CO2RR are addressed, which offers a fresh perspective for the future development of CTFs in photo/electrocatalytic CO2RR.
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In vitro dissolution profile has been shown to be correlated with the drug absorption and has often been considered as a metric for assessing in vitro bioequivalence between a test product and corresponding reference one. Various methods have been developed to assess the similarity between two dissolution profiles. In particular, similarity factor f2 has been reviewed and discussed extensively in many statistical articles. Although the f2 lacks inferential statistical properties, the estimation of f2 and its various modified versions were the most widely used metric for comparing dissolution profiles. In this paper, we investigated performances of the naive f2 estimate method, bootstrap f2 confidence interval method and bias corrected-accelerated (BCa) bootstrap f2 confidence interval method for comparing dissolution profiles. Our studies show that naive f2 estimate method and BCa bootstrap f2 confidence interval method are unable to control the type I error rate. The bootstrap f2 confidence interval method can control the type I error rate under a specific level. However, it will cause great conservatism on the power of the test. To solve the potential issues of the previous methods, we recommended a bootstrap bias corrected (BC) f2 confidence interval method in this paper. The type I error rate, power and sensitivity among different f2 methods were compared based on simulations. The recommended bootstrap BC f2 confidence interval method shows better control of type I error than the naive f2 estimate method and BCa bootstrap f2 confidence interval method. It also provides better power than the bootstrap f2 confidence interval method.
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Fator F , Humanos , Solubilidade , Equivalência Terapêutica , ViésRESUMO
BACKGROUND: Current studies in most Western countries have largely focused on body mass index (BMI) as an important risk factor for impaired glucose tolerance (IGT) and impaired fasting glucose (IFG), which have different pathophysiological bases. In people with obesity, the prevalence of IGT is higher and the prevalence of IFG is lower. The prevalence of IGT in the Asian population is higher than that in the white population, and the obesity rate in China is still increasing. However, few cohort studies explore the relationship between BMI and the incidence of IGT and IFG in China. We aimed to explore the relationship between BMI and the risk of IGT and IFG in Chinese adults and analyze the differences between them. METHODS: The baseline data were obtained from the 2010 China Chronic Disease and Risk Factor Surveillance, of which 20 surveillance sites were followed up from 2016 to 2017. Finally, in this study, a total of 5,578 studies were grouped into BMI categories of underweight (BMI < 18.5 kg/m2), normal weight (18.5-23.9 kg/m2), overweight (24.0-27.9 kg/m2), and obesity (≥ 28.0 kg/m2). We used the unconditional logistic regression model to analyze the relationship between BMI and the risk of IGT and IFG. RESULTS: During an average follow-up of 6.4 years, 562 developed IGT and 257 developed IFG. After age, gender, urban and rural areas, physical activity, family history of diabetes, hypertension, abdominal obesity, dyslipidemia, and other factors were adjusted, overweight increased the risk of IGT by 35% [odds ratio (OR) 1.35, 95% confidence interval (CI) 1.08-1.70], and obesity increased the risk of IGT by 77% (OR 1.77, 95% CI 1.27-1.47). After the factors consistent with the above were adjusted, only obesity increased the risk of IFG by 122% (OR 2.22, 95% CI 1.39-3.54). CONCLUSIONS: In China, obesity is an important risk factor for IGT and IFG, and the risk of IGT increases during the overweight stage.
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Intolerância à Glucose , Estado Pré-Diabético , Adulto , Humanos , Intolerância à Glucose/epidemiologia , Índice de Massa Corporal , Estudos Prospectivos , Sobrepeso/epidemiologia , População do Leste Asiático , Glicemia , Estado Pré-Diabético/epidemiologia , Obesidade/epidemiologia , JejumRESUMO
Four new germacrane sesquiterpene dilactones, 2ß-hydroxyl-11ß,13-dihydrodeoxymikanolide (1), 3ß-hydroxyl-11ß,13-dihydrodeoxymikanolide (2), 1α,3ß-dihydroxy-4,9-germacradiene-12,8:15,6-diolide (3), and (11ß,13-dihydrodeoxymikanolide-13-yl)-adenine (4), together with five known ones (5-9) were isolated from the aerial parts of Mikania micrantha. Their structures were elucidated on the basis of extensive spectroscopic analysis. Compound 4 is featured with an adenine moiety in the molecule, which is the first nitrogen-containing sesquiterpenoid so far isolated from this plant species. These compounds were evaluated for their in vitro antibacterial activity against four Gram-(+) bacteria of Staphyloccocus aureus (SA), methicillin-resistant Staphylococcus aureus (MRSA), Bacillus cereus (BC) and Curtobacterium. flaccumfaciens (CF), and three Gram-(-) bacteria of Escherichia coli (EC), Salmonella. typhimurium (SA), and Pseudomonas Solanacearum (PS). Compounds 4 and 7-9 were found to show strong in vitro antibacterial activity toward all the tested bacteria with the MIC values ranging from 1.56 to 12.5 µg/mL. Notably, compounds 4 and 9 showed significant antibacterial activity against the drug-resistant bacterium of MRSA with MIC value 6.25 µg/mL, which was close to reference compound vancomycin (MIC 3.125 µg/mL). Compounds 4 and 7-9 were further revealed to show in vitro cytotoxic activity toward human tumor A549, HepG2, MCF-7, and HeLa cell lines, with IC50 values ranging from 8.97 to 27.39 µM. No antibacterial and cytotoxic activity were displayed for the other compounds. The present research provided new data to support that M. micrantha is rich in structurally diverse bioactive compounds worthy of further development for pharmaceutical applications and for crop protection in agricultural fields.
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Antineoplásicos , Staphylococcus aureus Resistente à Meticilina , Mikania , Humanos , Mikania/química , Sesquiterpenos de Germacrano , Células HeLa , Antibacterianos/química , Bactérias , Testes de Sensibilidade MicrobianaRESUMO
FDA's experience to date has shown that completion of stability data requirements is one of the most observed challenges for applicants of New Drug Applications (NDAs) with an expedited review designation. Since NDAs submitted under these expedited pathways often have limited available real-time stability data from the primary batches, Modeling Approaches to Reimagine Stability (MARS) have been proposed to support establishment of tentative retest periods of the drug substance and/or expiration dating period (shelf-life) of the drug product. MARS incorporate statistical principles and available tools as a part of the predictive models. In this study, a data mining exercise has been conducted with regulatory submissions of Investigational New Drug (IND) Applications, NDAs, and Abbreviated New Drug Applications (ANDAs) containing MARS data. The case studies presented herein demonstrate how MARS data has been applied to regulatory scenarios involving prediction of retest and/or shelf-life, bridging major development changes, and confirming that no degradation has been observed or predicted. Using the assumption of a linear time trend for those cases that do not display sufficient degradation to conduct MARS for projection of an expiration date, an analysis of covariance (ANCOVA) model is developed and described herein to test the hypothesis of zero slope by a p-value method. Our results show that the application of MARS adequately supported establishment of a tentative commercially viable retest date/shelf-life, thus enabling earlier access to critical drugs for patients with unmet medical needs.
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Fatores de Tempo , Humanos , Estados Unidos , Previsões , United States Food and Drug AdministrationRESUMO
Depression is a common psychopathological state or mood disorder syndrome. The serious risks to human life and the inadequacy of the existing antidepressant drugs have driven us to understand the pathogenesis of depression from a new perspective. Our research group has found disturbances in glucose catabolism in both depression and nephrotic syndrome. What are the specific metabolic pathways and specificities of glucose catabolism disorders caused by depression? To address the above scientific questions, we creatively combined traditional metabolomics technology with stable isotope-resolved metabolomics to research the glucose catabolism of the corticosterone-induced PC12 cell damage model and the adriamycin-induced glomerular podocyte damage model. The results showed an increased flux of pyruvate metabolism in depression. The increased flux of pyruvate metabolism led to an activation of gluconeogenesis in depression. The disturbed upstream metabolism of succinate caused the tricarboxylic acid cycle (TCA cycle) to be blocked in depression. In addition, there were metabolic disturbances in the purine metabolism and pentose phosphate pathways in depression. Compared with nephrotic syndrome, pyruvate metabolism, the TCA cycle, and gluconeogenesis metabolism in depression were specific. The metabolic pathways researched above are likely to be important targets for the efficacy of antidepressants.
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Depressão , Síndrome Nefrótica , Corticosteroides , Animais , Ciclo do Ácido Cítrico , Depressão/induzido quimicamente , Feminino , Glucose/metabolismo , Humanos , Isótopos , Masculino , Metabolômica/métodos , Células PC12 , Ácido Pirúvico , RatosRESUMO
Melanocortin 5 receptor (MC5R), which is expressed in the terminally differentiated sebaceous gland, is a G protein-coupled receptor (GPCR). MC5R exists mostly in mammals but is completely lost in whales; only the relic of MC5R can be detected in manatees, and phenotypically, they have lost sebaceous glands. Interestingly, whales and manatees are both aquatic mammals but have no immediate common ancestors. The loss of MC5R and sebaceous glands in whales and manatees is likely to be a result of convergent evolution. Here, we find that MC5R in whales and manatees are lost by two different mechanisms. Homologous recombination of MC5R in manatees and the insertion of reverse transcriptase in whales lead to the gene loss, respectively. On one hand, in manatees, there are two "TTATC" sequences flanking MC5R, and homologous recombination of the segments between the two "TTATC" sequences resulted in the partial loss of the sequence of MC5R. On the other hand, in whales, reverse transcriptase inserts between MC2R and RNMT on the chromosome led to the loss of MC5R. Based on these two different mechanisms for gene loss in whales and manatees, we finally concluded that MC5R loss might be the result of convergent evolution to the marine environment, and we explored the impact on biological function that is significant to environmental adaptation.
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Trichechus , Baleias , Animais , Mamíferos , Filogenia , DNA Polimerase Dirigida por RNA/genética , Receptores de Melanocortina , Baleias/genéticaRESUMO
Zhizi Baipi decoction is a classic traditional Chinese medicine formula for the treatment of jaundice and various liver diseases. The chemical components of Zhizi baipi decoction were not clear resulting of the paucity of relevant studies, which hindered the elucidation of the pharmacological mechanism, and the comprehensive development and utilization of Zhizi baipi decoction in clinical. In this study, ultra-performance liquid chromatography-quadrupole-time of flight mass spectrometry combined with the UNIFI natural product information analysis platform was used to rapidly analyze and identify the chemical components in Zhizi baipi decoction. A total of 122 chemical components, including 53 flavonoids, 16 alkaloids, 25 terpenoids, five phenylpropanoids, 14 organic acids, and seven others, were identified from Zhizi baipi decoction. These compounds may be the active components of Zhizi baipi decoction. The method established in this study can systematically, rapidly, and accurately resolve the chemical components in Zhizi baipi decoction, which lays the foundation for further establishment of the pharmacodynamic substance basis and quality control of Zhizi baipi decoction.
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Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão/métodos , Medicamentos de Ervas Chinesas/análise , Espectrometria de Massas/métodos , Cromatografia Líquida , Flavonoides/análise , Informática , Terpenos/análiseRESUMO
BACKGROUND: In China, few studies have examined the relationship between the combination of body mass index and waist circumference and the risk of stroke. Moreover, the relationship may also be different in different genders. Thus, we investigated the association between the combination of body mass index and waist circumference and the risk of stroke in Chinese. METHODS: This prospective cohort study included 36 632 participants aged 18 to 90 years. Participants were recruited from 60 surveillance sites (25 urban sites and 35 rural sites) across China in 2010 China Chronic Disease Risk Factor Surveillance, and followed up in 2016-2017. Incident cases of stroke were identified through questionnaires (including the basis of clinical diagnosis, imaging tests, time of diagnosis, diagnosis unit) and Cardiovascular Event Report System. Risk factors for stroke were collected at baseline using questionnaire, physical measurements and laboratory tests. Cox proportional hazards regression models were used to generate adjusted hazard ratios and 95%CI. All analyses were duplicated by gender stratification. RESULTS: During 6.42 ± 0.50 years of follow-up, 1 333 (597 males, 736 females) stroke events were observed among the 27 112 participants who did not have cardiovascular diseases at baseline. Compared with the general population who have normal weight or underweight with normal WC, those who have normal weight or underweight with abdominal obesity (adjusted hazard ratios 1.45, 95%CI 1.07-1.97 in males; 0.98, 95%CI 0.78-1.24 in females), overweight with abdominal obesity (1.41, 95%CI 1.14-1.75 in males; 1.33, 95%CI 1.10-1.61 in females), obesity with abdominal obesity (1.46, 95%CI 1.11-1.91 in males; 1.46, 95%CI 1.17-1.81 in females). Overweight with normal WC was found to be not statistically significant for both males and females (all P>0.05). Subgroup analysis found a multiplicative interaction between age and anthropometric group in females (P for interaction <0.05). Sensitivity analysis results did not change. In the subjects with CVD risk factors, we found a similar relationship as in the general population . CONCLUSIONS: Combined assessment of body mass index and waist circumference identifies obesity patterns associated with stroke risk.
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Doenças Cardiovasculares , Acidente Vascular Cerebral , Índice de Massa Corporal , Doenças Cardiovasculares/epidemiologia , China/epidemiologia , Feminino , Humanos , Masculino , Obesidade/complicações , Obesidade/epidemiologia , Obesidade Abdominal/epidemiologia , Sobrepeso/complicações , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/epidemiologia , Magreza/complicações , Circunferência da CinturaRESUMO
Three new polycyclic phenol derivatives, 2-acetyl-4-hydroxy-6H-furo [2,3-g]chromen-6-one (1), 2-(1',2'-dihydroxypropan-2'-yl)-4-hydroxy-6H-furo [2,3-g][1]benzopyran-6-one (2) and 3,8,10-trihydroxy-4,9-dimethoxy-6H-benzo[c]chromen-6-one (8), along with seven known ones (3-7, 9 and 10) were isolated for the first time from the leaves of Spermacoce latifolia. Their structures were determined by spectroscopic analysis and comparison with literature-reported data. These compounds were tested for their in vitro antibacterial activity against four Gram-(+) bacteria: Staphyloccocus aureus (SA), methicillin-resistant Staphylococcus aureus (MRSA), Bacillus cereus (BC), Bacillus subtilis (BS), and the Gram-(-) bacterium Escherichia coli. Compounds 1, 2, 5 and 8 showed antibacterial activity toward SA, BC and BS with MIC values ranging from 7.8 to 62.5 µg/mL, but they were inactive to MRSA. Compound 4 not only showed the best antibacterial activity against SA, BC and BS, but it further displayed significant antibacterial activity against MRSA (MIC 1.95 µg/mL) even stronger than vancomycin (MIC 3.9 µg/mL). No compounds showed inhibitory activity toward E. coli. Further bioassay indicated that compounds 1, 4, 5, 6, 8 and 9 showed in vitro α-glucosidase inhibitory activity, among which compound 9 displayed the best α-glucosidase inhibitory activity with IC50 value (0.026 mM) about 15-fold stronger than the reference compound acarbose (IC50 0.408 mM). These results suggested that compounds 4, 8 and 9 were potentially highly valuable compounds worthy of consideration to be further developed as an effective anti-MRSA agent or effective α-glucosidase inhibitors, respectively. In addition, the obtained data also supported that S. latifolia was rich in structurally diverse bioactive compounds worthy of further investigation, at least in searching for potential antibiotics and α-glucosidase inhibitors.
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Antibacterianos , Inibidores de Glicosídeo Hidrolases , Fenóis , Rubiaceae , Antibacterianos/química , Antibacterianos/farmacologia , Bacillus cereus , Bacillus subtilis , Escherichia coli , Inibidores de Glicosídeo Hidrolases/química , Inibidores de Glicosídeo Hidrolases/farmacologia , Staphylococcus aureus Resistente à Meticilina , Testes de Sensibilidade Microbiana , Fenóis/química , Fenóis/farmacologia , Folhas de Planta/química , Rubiaceae/química , alfa-Glucosidases/farmacologiaRESUMO
The severe harm of depression to human life has attracted great attention to neurologists, but its pathogenesis is extremely complicated and has not yet been fully elaborated. Here, we provided a new strategy for revealing the specific pathways of abnormal brain glucose catabolism in depression, based on the supply of energy substrates and the evaluation of the mitochondrial structure and function. By using stable isotope-resolved metabolomics, we discovered that the tricarboxylic acid cycle (TCA cycle) is blocked and gluconeogenesis is abnormally activated in chronic unpredictable mild stress (CUMS) rats. In addition, our results showed an interesting phenomenon that the brain attempted to activate all possible metabolic enzymes in energy-producing pathways, but CUMS rats still exhibited a low TCA cycle activity due to impaired mitochondria. Depression caused the mitochondrial structure and function to be impaired and then led to abnormal brain glucose catabolism. The combination of the stable isotope-resolved metabolomics and mitochondrial structure and function analysis can accurately clarify the mechanism of depression. The mitochondrial pyruvate carrier and acetyl-CoA may be the key targets for depression treatment. The strategy provides a unique insight for exploring the mechanism of depression, the discovery of new targets, and the development of ideal novel antidepressants. Data are available via ProteomeXchange with identifier PXD025548.
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Depressão , Metabolômica , Animais , Encéfalo , Glucose , Isótopos , Ratos , Ratos Sprague-DawleyRESUMO
Porous MoS2nanofibers were synthesized by electroplating and post-annealing and applied in a responsive drug delivery system. The one-dimensional (1D) MoS2nanofibers displayed a high specific surface area, controllable morphology, and uniform size, serving as a promising drug carrier for chemotherapy. After surface modification with polyethylene glycol (PEG) through PEGylation, the MoS2/PEG composite displayed excellent physical/chemical stability and biocompatibility. More importantly, MoS2/PEG loaded with doxorubicin (DOX) exhibited a controllable release responsive to pH and near-infrared (NIR) irradiation and demonstrated precise DOX dose release. Such remarkable anticancer effects were mainly attributed to outstanding photothermal performance and stability of porous MoS2nanofibers. This work offered a new opportunity of employing porous MoS2nanofibers as drug carriers for effective cancer chemotherapy.
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Antineoplásicos , Dissulfetos , Portadores de Fármacos , Molibdênio , Nanofibras , Antineoplásicos/química , Antineoplásicos/farmacocinética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Dissulfetos/química , Dissulfetos/toxicidade , Doxorrubicina/química , Doxorrubicina/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/toxicidade , Células Hep G2 , Humanos , Concentração de Íons de Hidrogênio , Raios Infravermelhos , Molibdênio/química , Molibdênio/toxicidade , Nanofibras/química , Nanofibras/toxicidade , Terapia Fototérmica , Polietilenoglicóis/química , PorosidadeRESUMO
Five biochars derived from lotus seedpod (LSP) were applied to examine and compare the adsorption capacity of 17ß-estradiol (E2) from aqueous solution. The effect of KOH activation and the order of activation steps on material properties were discussed. The effect of contact time, initial concentration, pH, ionic strength and humic acid on E2 adsorption were investigated in a batch adsorption process. Experimental results demonstrated that the pseudo second-order model fitted the experimental data best and that adsorption equilibrium was reached within 20â¯hr. The efficiency of E2 removal increased with increasing E2 concentration and decreased with the increase of ionic strength. E2 adsorption on LSP-derived biochar (BCs) was influenced little by humic acid, and slightly affected by the solution pH when its value ranged from 4.0 to 9.0, but considerably affected at pHâ¯10.0. Low environmental temperature is favorable for E2 adsorption. Chemisorption, π-π interactions, monolayer adsorption and electrostatic interaction are the possible adsorption mechanisms. Comparative studies indicated that KOH activation and the order of activation steps had significant impacts on the material. Post-treated biochar exhibited better adsorption capacity for E2 than direct treated, pre-treated, and raw LSP biochar. Pyrolyzed biochar at higher temperature improved E2 removal. The excellent performance of BCs in removing E2 suggested that BCs have potential in E2 treatment and that the biochar directly treated by KOH would be a good choice for the treatment of E2 in aqueous solution, with its advantages of good efficiency and simple technology.
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Estradiol/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Adsorção , Carvão Vegetal , Temperatura Alta , Substâncias Húmicas , Concentração de Íons de Hidrogênio , Hidróxidos , Cinética , Lotus , Concentração Osmolar , Compostos de Potássio , Sementes , TemperaturaRESUMO
Regional inequality has caused large social and economic problems in China. Numerous researchers have sought to understand the status of economic inequality in the past decades. However, studies are lacking on other aspects of regional inequality, particularly when multiple facets must be considered. In this study, we have innovatively proposed a Pareto law-based method that can help assess multiple dimensions of regional inequality simultaneously. With this approach, we can rank multiple aspects of inequality and provide robust, reasonable goals for different groups of administrative districts. The proposed approach was successfully implemented by using Chinese data for 2015 and 2016, a period during which China was experiencing both severe PM2.5 pollution and economic regional inequality. The results indicate that (1) Shanghai and Shenzhen represent the optimal condition of economic development; (2) different from the spatial distribution of economic inequality alone, inequality was higher in central China for both economic development and PM2.5 air quality; (3) in the context of severe economic inequality in China, the tradeoff between economic development and air quality will result in a relatively equitable condition. In addition, the proposed method is open-ended and can be extended to incorporate more aspects of regional inequality. This approach appears to possess substantial potential for integration into decision-making regarding regional inequality.
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Poluentes Atmosféricos , Poluição do Ar , China , Desenvolvimento Econômico , Monitoramento Ambiental , Material Particulado , Fatores SocioeconômicosRESUMO
In this work, we demonstrated the preparation of the carbonized montmorillonite/carboxymethyl cellulose (MMT/CMC) hybrids and their application as an adsorbent for efficient removal of 17ß-Estradiol (ßE2). X-ray diffractometer (XRD) results showed that CMC intercalation reached saturation at a CMC to MMT weight ratio of 1; transmission electron microscope (TEM) measurements clearly revealed that carbonization caused graphenes distribute on the MMT surfaces; pyrolysis temperature at 600⯰C yielded novel MMT/CMC sample of high surface areas as reflected by Brunauer-Emmett-Teller (BET) surface area. The adsorbed amount of ßE2 under various conditions decreased in the order MMT/CMC1:1(600)â¯>â¯MMT/CMC1:1(450)â¯>â¯MMT/CMC1:1(300)â¯â¼â¯MMT/CMC2:1(600)â¯â¼â¯MMTâ¯>â¯MMT/CMC5:1(600). The removal of ßE2 by MMT/CMC1:1(600) occurred very quickly, and the adsorption kinetics could be well fitted by the Ritchie nth-order kinetic model; the best-fit adsorption isotherm model was Freundlich model. The MMT/CMC1:1(600) also exhibited good regeneration performance after five adsorption/desorption cycles. The experimental results also showed that the adsorption of ßE2 on the MMT/CMC1:1(600) composite could contribute to hydrophobic partitioning, π-π staking interaction, H-bond interaction, pore-filling effect and simple van der Waals interaction. This highly effective and novel adsorbent can be easily synthesized and regenerated, indicating its great potential in drinking and wastewater purification for endocrine disruptor compounds.
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Poluentes Químicos da Água , Purificação da Água , Adsorção , Bentonita , Carbono , Carboximetilcelulose Sódica , Estradiol , Cinética , Pirólise , ÁguaRESUMO
Biochar is regarded as a promising new class of materials due to its multifunctional character and the possibility of effectively coupling different properties. With increasing introduction into the environment, environmental chemicals such as surfactants will load onto the released biochar and change its physicochemical characteristics and adsorption behavior toward pollutants. In this study, sodium dodecyl sulfate (SDS), as one type of anionic surfactant, was coated onto biochar with different loading amounts. The influence of SDS loading onto biochar's physicochemical properties were investigated by Fourier transform infrared (FT-IR) spectroscopy, elemental analysis, zeta potential and Brunauer-Emmett-Teller (BET) surface area and pore size distribution analysis. Results showed that the pore size of the biochar decreased gradually with the increase of SDS loading because of the surface-adsorption and pore-blocking processes; the pH of the point of zero charge (pHPZC) decreased with increasing SDS loading. Although surface-coating with SDS decreased the pore size of the biochar, its adsorption capacity toward Methylene Blue (MB) significantly increased. The biochar-bound SDS introduced functional groups and negative charges to the biochar surface, which could thus enhance the adsorption of MB via hydrogen bonding and electrostatic interaction. The results can shed light on the underlying mechanism of the influence of anionic surfactants on the adsorption of MB by biochar.
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Carvão Vegetal/química , Azul de Metileno/química , Modelos Químicos , Dodecilsulfato de Sódio/química , Poluentes Químicos da Água/química , AdsorçãoRESUMO
Adsorption of two estrogen contaminants (17ß-estradiol and 17α-ethynyl estradiol) by graphene nanomaterials was investigated and compared to those of a multi-walled carbon nanotube (MWCNT), a single-walled carbon nanotube (SWCNT), two biochars, a powdered activated carbon (PAC), and a granular activate carbon (GAC) in ultrapure water and in the competition of natural organic matter (NOM). Graphene nanomaterials showed comparable or better adsorption ability than carbon nanotubes (CNTs), biochars (BCs), and activated carbon (ACs) under NOM preloading. The competition of NOM decreased the estrogen adsorption by all adsorbents. However, the impact of NOM on the estrogen adsorption was smaller on graphenes than CNTs, BCs, and ACs. Moreover, the hydrophobicity of estrogens also affected the uptake of estrogens. These results suggested that graphene nanomaterials could be used to removal estrogen contaminants from water as an alternative adsorbent. Nevertheless, if transferred to the environment, they would also adsorb estrogen contaminants, leading to great environmental hazards.
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Estrogênios , Nanoestruturas , Poluentes Químicos da Água , Adsorção , Carbono , Carvão Vegetal , Grafite , Nanotubos de Carbono , Purificação da ÁguaRESUMO
To investigate the anti-oxidative effect of celastrol on H2O2-induced oxidative stress in the cell model of amyotrophic lateral sclerosis (ALS) and its molecular mechanism, NSC34 motor neuron-like cells were transfected with EGFP-G93A-SOD1 plasmid and used as in vitro ALS cell model. SOD1G93A transfected NSC34 cells were treated with different doses of H2O2 and celastrol. The survival rate of the cells was detected by CCK-8 assay, and malondialdehyde (MDA) content was detected by corresponding kit. The mRNA expression of glutamate-cysteine ligase catalytic subunit (GCLC) and glutathione S-transferases (GST) were detected by real-time PCR. The activation of intracellular MEK/ERK and PI3K/Akt signal pathways was detected by Western blot. The results showed that pre-incubation of celastrol (50 nmol/L) for 4 h prior to H2O2 (10 µmol/L) co-treatment for another 24 h significantly attenuated H2O2-induced cell death and MDA level in SOD1G93A transfected NSC34 cells. Real-time PCR showed that the mRNA expressions of GCLC and GST were enhanced with pre-incubation of celastrol. Celastrol quickly induced phosphorylation of ERK1/2 and Akt within 30 min and 1 h respectively in SOD1G93A transfected NSC34 cells. Pharmacological inhibitors of MEK (PD98059, 10 µmol/L) or Akt (MK2206, 10 µmol/L) could reverse the phosphorylation of ERK1/2 and Akt, and abolish up-regulation of GCLC and GST induced by celastrol at mRNA levels. Taken together, we conclude that celastrol exerts a beneficial antioxidant effect in SOD1G93ANSC34 cells, which might be dependent on MEK/ERK and PI3K/Akt signaling pathway activation.
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Esclerose Lateral Amiotrófica/tratamento farmacológico , Antioxidantes/farmacologia , Peróxido de Hidrogênio/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Triterpenos/farmacologia , Esclerose Lateral Amiotrófica/metabolismo , Animais , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Glutamato-Cisteína Ligase/genética , Camundongos , Triterpenos Pentacíclicos , Fosforilação , Triterpenos/uso terapêuticoRESUMO
A novel biochar/MgAl-layered double hydroxides composite (CB-LDH) was prepared for the removal of crystal violet from aqueous solution by pyrolyzing MgAl-LDH pre-coated ramie stem (Boehmeria nivea (L.) Gaud.). Pyrolysis played dual role for both converting biomass into biochar and calcining MgAl-LDH during the pyrolysis process. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray analysis (EDS), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) and zeta potential analysis were used to characterize the CB-LDH. The results of characterization suggested that the calcined LDH was successfully synthesized and coated on biochar. The resulted CB-LDH had higher total pore volume and more functional groups than the pristine biochar. Adsorption experimental data fitted well with the pseudo-second order kinetics model and the Freundlich isotherm model. The rate-controlled step was controlled by film-diffusion initially and then followed by intra-particle diffusion. Thermodynamic analysis showed that the adsorption of crystal violet was a spontaneous and endothermic process. The higher pH and temperature of the solution enhanced the adsorption performance. CB-LDH could also have excellent ability for the removal of crystal violet from the actual industrial wastewater and groundwater with high ionic strength. LDH adsorption, electrostatic attraction, pore-filling, π-π interaction and hydrogen bond might be the main mechanisms for crystal violet adsorption on CB-LDH. The results of this study indicated that CB-LDH is a sustainable and green adsorbent with high performance for crystal violet contaminated wastewater treatment and groundwater remediation.