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1.
J Hazard Mater ; 389: 122131, 2020 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-32004839

RESUMO

Inhibition of high calcium during anaerobic wastewater treatment has been studied in recent years, focusing on calcium precipitates in anaerobic granule but neglecting the effect of functional microbes. In this study, key factors of calcification and microbial behaviors especially methanogens of calcified anaerobic granule (AnGS) were investigated in batch assays with calcium level varying from 0 to 5 g L-1. The results showed that the COD removal efficiency and specific methane activity of calcified AnGS were restrained with calcium addition, especially high calcium (>2 g L-1), and little tolerance of calcified AnGS to Ca2+ was underlined compared with non-calcified AnGS. Analysis of calcium mass flow from solution to sludge validated the formation of calcium precipitates influenced by calcium concentration, pH and HCO3-. Besides, death of microbes in outer layer of anaerobic granules was triggered by calcium precipitation. Most importantly, aceticlastic Methanothrix genus was the dominant methanogen, and its relative abundance was correlative negatively with cumulative decrease of bulk Ca2+. Hydrogenotrophic Methanobacterium was enriched at higher calcium level, and it suggested that hydrogenotrophic methanogenesis could play a role in alleviating the inhibition of high calcium.

2.
Bioresour Technol ; 302: 122805, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32007847

RESUMO

Anaerobic membrane bioreactor (AnMBR) is an advanced technology in treating pharmaceutical wastewater, but the membrane fouling limits its development. In this study, the biochar with adsorption capacity of biopolymers was added in AnMBR to investigate its potential in treating pharmaceutical wastewater and alleviating membrane fouling. In the biochar-amended AnMBR, adsorbable organic halogen (AOX) was removed effectively, and more COD was biotransformed into CH4. Membrane fouling mitigation was achieved in the third stage with a 56% decrease of average transmembrane pressure difference (TMP) rising rate. The predominant culprit, proteins of extracellular polymeric substance (EPS-proteins) in sludge mixture and cake layer, was reduced significantly. Particularly, the proportion of micromolecular (0.1-0.15 kDa) EPS-proteins in cake layer was 1.5-folds that of the control group. The important bio-foulant genus Arcobacter aggregating on the membrane had less and almost half the relative abundance (16.5%) than that of the control group (30.7%).

3.
Elife ; 92020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32043463

RESUMO

Guanine-rich DNA sequences can fold into four-stranded G-quadruplex (G4-DNA) structures. G4-DNA regulates replication and transcription, at least in cancer cells. Here, we demonstrate that, in neurons, pharmacologically stabilizing G4-DNA with G4 ligands strongly downregulates the Atg7 gene. Atg7 is a critical gene for the initiation of autophagy that exhibits decreased transcription with aging. Using an in vitro assay, we show that a putative G-quadruplex-forming sequence (PQFS) in the first intron of the Atg7 gene folds into a G4. An antibody specific to G4-DNA and the G4-DNA-binding protein PC4 bind to the Atg7 PQFS. Mice treated with a G4 stabilizer develop memory deficits. Brain samples from aged mice contain G4-DNA structures that are absent in brain samples from young mice. Overexpressing the G4-DNA helicase Pif1 in neurons exposed to the G4 stabilizer improves phenotypes associated with G4-DNA stabilization. Our findings indicate that G4-DNA is a novel pathway for regulating autophagy in neurons.

4.
Brain Behav Immun ; 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32058038

RESUMO

INTRODUCTION: Stroke is a sexually dimorphic disease. While women account for more stroke deaths, recent data show that after adjusting for age and pre-stroke functional status, mortality is higher in men. Immune responses are key determinants of stroke outcome and may differ by sex. This study examined sex differences in central and peripheral T cell immune responses, systemic effects on gut permeability and microbiota diversity and behavioral outcomes after stroke in aged mice. We hypothesized that there are sex differences in the immune response to stroke in aged animals. METHODS: C57BL/6N mice (20-22 months) were subjected to 60 min middle cerebral artery occlusion, or sham surgery. T cells were quantified in brain and blood at 3, 7 and 15 days (d) post-stroke by flow cytometry. Peripheral effects on gut permeability and microbiota diversity, as well as neurological function were assessed up to 14d, and at 21d (cognitive function) post-stroke. Brain glial fibrillary acidic protein (GFAP) expression was evaluated at 42d post-stroke. RESULTS AND DISCUSSION: Mortality (50% vs 14%, p<0.05) and hemorrhagic transformation (44% vs 0%) were significantly higher in males than in females. No difference in infarct size at 3d were observed. Peripherally, stroke induced greater gut permeability of FITC-dextran in males at d3 (p<0.05), and non-reversible alterations in microbiota diversity in males. Following the sub-acute phase, both sexes demonstrated a time-dependent increase of CD4+ and CD8+ T cells in the brain, with significantly higher levels of CD8+ T cells and Regulatory T cells in males at d15 (p<0.01). Aged males demonstrated greater neurological deficits up to d5 and impaired sensorimotor function up to d15 when assessed by the corner asymmetry test (p<0.001 and p<0.01, respectively). A trend in greater cognitive decline was observed at d21 in males. Increased GFAP expression in the ischemic hemisphere, indicating astroglial activation and gliosis, was demonstrated in both males and females 42d post-stroke. Our findings indicate that despite a similar initial ischemic brain injury, aged male mice experience greater peripheral effects on the gut and ongoing central neuroinflammation past the sub-acute phase after stroke.

5.
Phys Chem Chem Phys ; 22(6): 3748, 2020 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-32022090

RESUMO

Correction for 'Understanding of binding energy calibration in XPS of lanthanum oxide by in situ treatment' by Jerry Pui Ho Li et al., Phys. Chem. Chem. Phys., 2019, 21, 22351-22358.

7.
Arthritis Res Ther ; 22(1): 7, 2020 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-31924265

RESUMO

BACKGROUND: To explore the clinical patterns of patients with IgG4-related disease (IgG4-RD) based on laboratory tests and the number of organs involved. METHODS: Twenty-two baseline variables were obtained from 154 patients with IgG4-RD. Based on principal component analysis (PCA), patients with IgG4-RD were classified into different subgroups using cluster analysis. Additionally, IgG4-RD composite score (IgG4-RD CS) as a comprehensive score was calculated for each patient by principal component evaluation. Multiple linear regression was used to establish the "IgG4-RD CS" prediction model for the comprehensive assessment of IgG4-RD. To evaluate the value of the IgG4-RD CS in the assessment of disease severity, patients in different IgG4-RD CS groups and in different IgG4-RD responder index (RI) groups were compared. RESULTS: PCA indicated that the 22 baseline variables of IgG4-RD patients mainly consisted of inflammation, high serum IgG4, multi-organ involvement, and allergy-related phenotypes. Cluster analysis classified patients into three groups: cluster 1, inflammation and immunoglobulin-dominant group; cluster 2, internal organs-dominant group; and cluster 3, inflammation and immunoglobulin-low with superficial organs-dominant group. Moreover, there were significant differences in serum and clinical characteristics among subgroups based on the CS and RI scores. IgG4-RD CS had a similar ability to assess disease severity as RI. The "IgG4-RD CS" prediction model was established using four independent variables including lymphocyte count, eosinophil count, IgG levels, and the total number of involved organs. CONCLUSION: Our study indicated that newly diagnosed IgG4-RD patients could be divided into three subgroups. We also showed that the IgG4-RD CS had the potential to be complementary to the RI score, which can help assess disease severity.

8.
Acta Pharmacol Sin ; 2020 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-31969689

RESUMO

Vonoprazan is characterized as having a long-lasting antisecretory effect on gastric acid. In this study we developed a physiologically based pharmacokinetic (PBPK)-pharmacodynamic (PD) model linking to stomach to simultaneously predict vonoprazan pharmacokinetics and its antisecretory effects following administration to rats, dogs, and humans based on in vitro parameters. The vonoprazan disposition in the stomach was illustrated using a limited-membrane model. In vitro metabolic and transport parameters were derived from hepatic microsomes and Caco-2 cells, respectively. We found the most predicted plasma concentrations and pharmacokinetic parameters of vonoprazan in rats, dogs and humans were within twofold errors of the observed data. Free vonoprazan concentrations (fu × C2) in the stomach were simulated and linked to the antisecretory effects of the drug (I) (increases in pH or acid output) using the fomula dI/dt = k × fu × C2 × (Imax - I) - kd × I. The vonoprazan dissociation rate constant kd (0.00246 min-1) and inhibition index KI (35 nM) for H+/K+-ATPase were obtained from literatures. The vonoprazan-H+/K+-ATPase binding rate constant k was 0.07028 min-1· µM-1 using ratio of kd to KI. The predicted antisecretory effects were consistent with the observations following intravenous administration to rats (0.7 and 1.0 mg/kg), oral administration to dogs (0.3 and 1.0 mg/kg) and oral single dose or multidose to humans (20, 30, and 40 mg). Simulations showed that vonoprazan concentrations in stomach were 1000-fold higher than those in the plasma at 24 h following administration to human. Vonoprazan pharmacokinetics and its antisecretory effects may be predicted from in vitro data using the PBPK-PD model of the stomach. These findings may highlight 24-h antisecretory effects of vonoprazan in humans following single-dose or the sustained inhibition throughout each 24-h dosing interval during multidose administration.

9.
APMIS ; 2020 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-31976578

RESUMO

We aimed to investigate whether the gene polymorphisms of TLR10 was associated with risk and severity of pneumococcal meningitis (PM) and serum cytokine levels in children. Three single nucleotide polymorphisms (SNPs) of TLR10 rs4129009 (2676A>G), rs10004195 (1018T>A) and rs11466617 (40735A>G) were studied in 95 laboratory-confirmed PM pediatric patients and 330 healthy controls by PCR-based sequencing. Ten serum cytokines were determined by multiplex immunoassay. The frequency of variant haplotype GAG of TLR10 was significantly lower in patients than controls (11.3% vs. 33.3%, p <0.001), although frequencies of the genotypes and alleles of the three SNPs did not differ between patients and controls. Frequency of variant haplotype GAG was significantly lower in patients who had CSF protein > 1000 mg/L than those who had CSF protein ≤1000 mg/L (3.50% vs. 32.4%, p <0.001). Moreover, higher frequency of the haplotype GAG was found in patients who had higher levels of inflammatory cytokines such as IFN-γ, TNF-α and IL-1ß. Our finding suggested that the variant haplotype GAG in TLR10 is associated with decreased risk of PM in Chinese children.

10.
IEEE Trans Cybern ; 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31985451

RESUMO

Achieving high classification performance in electroencephalogram (EEG)-based brain-computer interfaces (BCIs) often entails a large number of channels, which impedes their use in practical applications. Despite the previous efforts, it remains a challenge to determine the optimal subset of channels in a subject-specific manner without heavily compromising the classification performance. In this article, we propose a new method, called spatiotemporal-filtering-based channel selection (STECS), to automatically identify a designated number of discriminative channels by leveraging the spatiotemporal information of the EEG data. In STECS, the channel selection problem is cast under the framework of spatiotemporal filter optimization by incorporating a group sparsity constraints, and a computationally efficient algorithm is developed to solve the optimization problem. The performance of STECS is assessed on three motor imagery EEG datasets. Compared with state-of-the-art spatiotemporal filtering algorithms using full EEG channels, STECS yields comparable classification performance with only half of the channels. Moreover, STECS significantly outperforms the existing channel selection methods. These results suggest that this algorithm holds promise for simplifying BCI setups and facilitating practical utility.

11.
Biofouling ; : 1-18, 2020 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-31928216

RESUMO

The impact of feed water quality on biofilm formation during membrane distillation (MD) was investigated in this study, particularly emphasizing the interrelationship between organics, salts, and microbes. Two types of typical natural surface waters in Nanjing, China, were chosen as feed solutions for long-term MD operation, including the Qinhuai River and Xuanwu Lake. The biofilms that developed under different feed water qualities exhibited distinct Foulant compositions and structures, causing different flux decline trends for the MD system. Accordingly, two typical patterns of biofilm formation were suggested for the MD operation of the two different kinds of surface waters in this study. Organics from a primal feed solution and dead bacteria were the key to the establishment of a biofilm on the membrane, and this needs to be effectively removed from the MD system through pre-treatment and process control strategies. Finally, a feasible strategy for MD biofouling control was suggested.

12.
Transplant Proc ; 52(1): 383-391, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31959353

RESUMO

BACKGROUND: Hypoxia-inducible factor 1 alpha (HIF-1α) is a transcription factor that plays a major role under hypoxia conditions. Cold storage during heart transplantation causes the donor heart long-term hypoxia. There is some evidence indicating a conceivable HIF-1α/microRNA-21 (miR-21)/phosphatase and tensin homolog (PTEN)/programmed cell death 4 (PDCD4) pathway. We assessed the hypothesis that HIF-1α has a positive effect during donor heart cold storage by making the miR-21 upregulate to reduce the expression of PDCD4. METHODS: We established the rat heart cold storage model and stratified it into 6-hour groups from 0 to 24 hours. Western blot and quantitative reverse transcription polymerase chain reaction were performed to detect the expression of HIF-1α, miR-21, PDCD4, and PTEN. RESULTS: After cold storage the expression of HIF-1α increased from 0 to 6 hours and then gradually decreased, but the expression level was relatively higher compared with the control group. The miR-21 was upregulated from 0 to 12 hours then downregulated. The messenger RNA expression of PDCD4 was upregulated gradually, but the protein expression was significantly downregulated at 12th hour then continued to upregulate. Interestingly, the expression level of miR-21 was highest in the 12th hour, which indicated miR-21 could inhibit the PDCD4. We subsequently detected the messenger RNA of PTEN, which can inhibit HIF-1α and be inhibited by miR-21. The expression of PTEN was also significantly downregulated at the 12th hour. CONCLUSION: In conclusion, there is possible interaction between HIF-1α and miR-21, and the conceivable HIF-1α/miR-21/PTEN/PDCD4 pathway plays a protective role in cold storage of the heart.

13.
Medicine (Baltimore) ; 99(1): e18536, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31895789

RESUMO

It remains challenging for endoscopists to manage pancreaticobiliary diseases in patients with ectopic papilla of Vater by endoscopic retrograde cholangiopancreatography (ERCP). The present study sought to evaluate the efficacy and safety of ERCP for this issue.Consecutive patients with ectopic papilla of Vater who underwent initial ERCP due to pancreaticobiliary diseases were retrospectively analyzed.One hundred seven patients with ectopic papilla of Vater were included. The success rate of cannulation was 83.2%. Endoscopic sphincterotomy, endoscopic papillary balloon dilation, and mechanical lithotripsy were performed in 12 (11.2%), 25 (23.4%), and 1 (0.9%) patients, respectively. The technical success rate was 83.2%; of these, endoscopic nasobiliary drainage, endoscopic retrograde biliary drainage, endoscopic retrograde pancreatic drainage, and stone extraction was conducted in 61 (57.0%), 17 (15.9%), 5 (4.7%), and 45 (42.1%) patients, respectively. Bile duct stone size ≥1 cm, number ≥2, and duodenum stenosis were risk factors for stone extraction inability. Adverse events occurred in 20 (18.7%) patients, including post-ERCP pancreatitis (3.7%), hyperamylasemia (12.1%), and infection of biliary tract (2.8%); all of the adverse events were mild and alleviated by conventional therapies.ERCP is an appropriate choice for pancreaticobiliary diseases in patients with ectopic papilla of Vater due to its high efficacy and safety. Bile duct stone size ≥1 cm, number ≥2, and duodenum stenosis increase difficulties for stone extraction.


Assuntos
Ampola Hepatopancreática , Doenças Biliares/cirurgia , Colangiopancreatografia Retrógrada Endoscópica/métodos , Coristoma/cirurgia , Duodenopatias/cirurgia , Pancreatopatias/cirurgia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
14.
IEEE Trans Neural Syst Rehabil Eng ; 28(1): 328-338, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31825869

RESUMO

To enhance the performance of the brain-actuated robot system, a novel shared controller based on Bayesian approach is proposed for intelligently combining robot automatic control and brain-actuated control, which takes into account the uncertainty of robot perception, action and human control. Based on maximum a posteriori probability (MAP), this method establishes the probabilistic models of human and robot control commands to realize the optimal control of a brain-actuated shared control system. Application on an intelligent Bayesian shared control system based on steady-state visual evoked potential (SSVEP)-based brain machine interface (BMI) is presented for all-time continuous wheelchair navigation task. Moreover, to obtain more accurate brain control commands for shared controller and adapt the proposed system to the uncertainty of electroencephalogram (EEG), a hierarchical brain control mechanism with feedback rule is designed. Experiments have been conducted to verify the proposed system in several scenarios. Eleven subjects participated in our experiments and the results illustrate the effectiveness of the proposed method.

15.
Trends Endocrinol Metab ; 31(1): 46-52, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31629614

RESUMO

Obesity is a neurological disorder that operates by favoring energy storage within adipose depots and increased caloric intake. Most cases of human obesity are acquired without any underlying genetic basis. Here, we suggest that obesity can impair the function of some hypothalamic neurons critical to body weight regulation. Genetic ablation of the retinoblastoma (Rb) gene within pro-opiomelanocortin (POMC) neurons leads to death of the neurons and subsequent obesity. The Rb protein (pRb), a key inhibitor of the cell cycle, can also be inactivated by cyclin dependent kinase (CDK)-mediated phosphorylation. Extensive development led to the production of FDA-approved CDK4/6 inhibitors. Based on our own results, we propose that maintaining or re-instating pRb function using CDK4/6 inhibitors are potentially effective treatments of diet-induced obesity (DIO).

16.
Biochem Biophys Res Commun ; 521(2): 285-289, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31668374

RESUMO

Apoptosis is associated with various cardiovascular diseases. CGRP exerts a variety of effects within the cardiovascular system, and protects against the onset and development of angiotensin (Ang) II-induced vascular dysfunction and remodelling. However, it is not known whether CGRP has a direct effect on Ang II-induced apoptosis in vascular smooth muscle cells (VSMCs), and the mechanism underlying the anti-apoptotic role remains unclear. In this study, CGRP significantly suppressed reactive oxygen species (ROS) and apoptosis in Ang II-induced VSMCs. In VSMCs pre-treated with a CGRP receptor antagonist (CGRP8-37), the CGRP-mediated inhibition of Ang II-induced ROS and apoptosis was completely abolished. Moreover, pre-treatment with N-acetyl-L cysteine (NAC), an ROS scavenger, blocked the effects of CGRP on Ang II-induced apoptosis. In addition, the activation of CaMKII and the downstream transcription factor CREB stimulated by Ang II was abrogated by CGRP. Importantly, in both CGRP and NAC-treated VSMCs, CGRP failed to further attenuate CaMKII and CREB activation. The results demonstrate that CGRP attenuated Ang II-induced ROS-dependent apoptosis in VSMCs by inhibiting the CaMKII/CREB signalling pathway.

17.
Cancer ; 126(4): 840-849, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31714592

RESUMO

BACKGROUND: The thoracic radiotherapy (TRT) target volume for limited-stage small-cell lung cancer (SCLC) has been controversial for decades. In this report, the final results of a prospective randomized trial on the TRT target volume before and after induction chemotherapy are presented. METHODS: After 2 cycles of etoposide and cisplatin, patients arm were randomized to receive TRT to the postchemotherapy or prechemotherapy tumor volume in a study arm and a control arm. Involved-field radiotherapy was received in both arms. TRT consisted of 1.5 grays (Gy) twice daily in 30 fractions to up to a total dose of 45 Gy. Lymph node regions were contoured, and intentional and incidental radiation doses were recorded. RESULTS: The study was halted early because of slow accrual. Between 2002 and 2017, 159 and 150 patients were randomized to the study arm or the control arm, respectively; and 21.4% and 19.1% of patients, respectively, were staged using positron emission tomography/computed tomography (P = .31). With a median follow-up of 54.1 months (range, 19.9-165.0 months) in survivors, the 3-year local/regional progression-free probability was 58.2% and 65.5% in the study and control arms, respectively (P = .44), and the absolute difference was -7.3% (95% CI, -18.2%, 3.7%). In the study and control arms, the median overall survival was 21.9 months and 26.6 months, respectively, and the 5-year overall survival rate was 22.8% and 28.1%, respectively (P = .26). Grade 3 esophagitis was observed in 5.9% of patients in the study arm versus 15.5% of those in the control arm (P = .01). The isolated out-of-field failure rate was 2.6% in the study arm versus 4.1% in the control arm (P = .46), and all such failures were located in the supraclavicular fossa or contralateral hilum. The regions 7, 3P, 4L, 6, 4R, 5, and 2L received incidental radiation doses >30 Gy. CONCLUSIONS: TRT could be limited to the postchemotherapy tumor volume, and involved-field radiotherapy could be routinely applied for limited-stage SCLC.

18.
J Cell Biochem ; 121(2): 1649-1663, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31560409

RESUMO

The exploration of an effective method for preventing and treating pressure ulcers (PUs) is a hot topic in medical research. Recently, disputes about the choice of heat and cold therapies have emerged for the prevention and treatment of clinical PUs. The present study was designed to compare the effect of cool and heat therapies on pyroptosis and apoptosis of early-stage PUs in rats. Sixty SD rats of SPF grade were randomly divided into the sham group, model group, heating group, and cooling group. We established a rat model of early-stage PUs by using an ischemia-reperfusion method. At the end of the experiment, the tissue underneath the compressed region was collected for hematoxylin and eosin staining, transmission electron microscopy, immunohistochemistry, immunofluorescence staining, a TdT-mediated dUTP nick-end labeling assay, a Western blot analysis, and a mitochondrial swelling experiment. Our results suggested that the mitochondrial apoptotic pathway and pyroptosis were involved in the formation of early-stage PUs, and local heating increased the PU injury in rats, while local cooling reduced the PU injury in rats. This study showed that heat therapy might not be suitable for the clinical treatment and care of early-stage PUs, while cold therapy may be more appropriate.

19.
Pest Manag Sci ; 76(2): 534-542, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31270930

RESUMO

BACKGROUND: Dengue fever is caused by the spread of dengue virus by Aedes mosquito vectors. Currently, the most effective way to control dengue is by preventing mosquitoes from spreading the disease. Arisaema fargesii is a Chinese herbal medicine commonly used to repel mosquitoes. In our laboratory, anti-mosquito chemical components were extracted from A. fargesii, and the effects of these substances on mosquito larvae were examined. RESULTS: In total, 48 compounds corresponding to 98.79% of the total oil were identified and the major compounds identified were linalool (12.38%), carvacrol (8.27%), eugenol (5.21%), and ß-selinene (5.36%). Essential oil had larvicidal activity against Ae. aegypti and Ae. albopictus with LC50 values of 40.49 mg/L, 47.01 mg/L, respectively. The LC50 values of carvacrol, eugenol, linalool and ß-selinene were 32.78, 56.34, 70.56, 136.03 mg/L against Ae. aegypti larvae, and 39.08, 52.07, 82.34, 151.74 mg/L, respectively, against Ae. albopictus larvae. Biochemical assays of Aedes larvae showed that the activities of acetylcholinesterase (AChE), monooxygenases (MO), glutathione-S-transferase (GST), p-Nitrophenyl acetate (p-NPA) esterase, α-esterase and ß-esterase were significantly affected by carvacrol. Essential oil induced the detoxification mechanism for the action of GST and MO. CONCLUSION: The result indicates that essential oil of A. fargesii and its isolated constituent have good inhibitory effects on the defense enzymes of Aedes mosquito larvae. A. fargesii essential oil can be used to control Aedes mosquito larvae to prevent the spread of dengue fever. © 2019 Society of Chemical Industry.

20.
Environ Sci Technol ; 54(3): 1909-1919, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-31886657

RESUMO

In this study, a permanganate/redox mediator system for enhanced transformation of a series of emerging contaminants was evaluated. The presence of various redox mediators (i.e., 1-hydroxybenzotriazole, N-hydroxyphthalimide, violuric acid, syringaldehyde, vanillin, 4-hydroxycoumarin, and p-coumaric acid) accelerated the degradation of bisphenol A (BPA) by Mn(VII). Since 1-hydroxybenzotriazole (HBT) exhibited the highest reactive ability, it was selected to further investigate the reaction mechanisms and quantify the effects of important reaction parameters on Mn(VII)/redox-mediator reactions with BPA and bisphenol AF (BPAF). Interestingly, not only HBT accelerated the degradation of BPA, but also BPA enhanced the decay of HBT. Evidence for the in situ formation of HBT· radicals as the active oxidant responsible for accelerated BPA and BPAF degradation was obtained by radical scavenging experiments and 31P NMR spin trapping techniques. The routes for HBT· radical formation involving Mn(VII) and the electron-transfer pathway from BPA/BPAF to HBT· radicals demonstrate that the Mn(VII)/HBT system was driven by the electron-transfer mechanism. Compared to Mn(VII) alone, the presence of HBT totally inhibited self-coupling of BPA and BPAF and promoted ß-scission, hydroxylation, ring opening, and decarboxylation reactions. Moreover, Mn(VII)/HBT is also effective in real waters with the order of river water > wastewater treatment plant (WWTP) effluent > deionized water.

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