Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 936
Filtrar
1.
Stroke ; : STROKEAHA120032424, 2021 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-33947206

RESUMO

BACKGROUND AND PURPOSE: Whether imaging parameters would independently predict stroke recurrence in low-risk minor ischemic stroke (MIS) or transient ischemic attack (TIA) according to traditional score system (such as ABCD2 score, which was termed on the basis of the initials of the five factors: age, blood pressure, clinical features, duration, diabetes) remains unclear. We sought to evaluate the association between imaging parameters and 1-year stroke recurrence in patients with TIA or MIS in different risk stratum stratified by ABCD2 score. METHODS: We included patients with TIA and MIS (National Institutes of Health Stroke Scale score ≤3) with complete baseline vessel and brain imaging data from the Third China National Stroke Registry III. Patients were categorized into different risk groups based on ABCD2 score (low risk, 0-3; moderate risk, 4-5; and high risk, 6-7). The primary outcome was stroke recurrence within 1 year. Multivariable Cox proportional-hazards regression models were used to assess whether imaging parameters (large artery stenosis, infarction number) were independently associated with stroke recurrence. RESULTS: Of the 7140 patients included, 584 patients experienced stroke recurrence within 1 year. According to the ABCD2 score, large artery stenosis was associated with higher stroke recurrence in both low-risk (adjusted hazard ratio, 1.746 [95% CI, 1.200-2.540]) and moderate-risk group (adjusted hazard ratio, 1.326 [95% CI, 1.042-1.687]) but not in the high-risk group (P>0.05). Patients with multiple acute infarctions or single acute infarction had a higher risk of recurrent stroke than those with no infarction in both low- and moderate-risk groups, but not in the high-risk group. CONCLUSIONS: Large artery stenosis and infarction number were independent predictors of 1-year stroke recurrence in low-moderate risk but not in high-risk patients with TIA or MIS stratified by ABCD2 score. This finding emphasizes the importance of early brain and vascular imaging evaluation for risk stratification in patients with TIA or MIS.

2.
Medicine (Baltimore) ; 100(18): e25615, 2021 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-33950940

RESUMO

BACKGROUND: Type 2 diabetes is an emergent worldwide health crisis, and rates are growing globally. Aerobic exercise is an essential measure for patients with diabetes, which has the advantages of flexible time and low cost. Aerobic exercise is a popular method to reduce blood glucose. Due to the lack of randomized trials to compare the effects of various aerobic exercises, it is difficult to judge the relative efficacy. Therefore, we intend to conduct a network meta-analysis to evaluate these aerobic exercises. METHODS: According to the retrieval strategies, randomized controlled trials on different aerobic exercise training will be obtained from China National Knowledge Infrastructure, WanFang, SinoMed, PubMed, Web of Science, EMBASE, and Cochrane Library, regardless of publication date or language. Studies were screened based on inclusion and exclusion criteria, and the Cochrane risk bias assessment tool will be used to evaluate the quality of the literature. The network meta-analysis will be performed in Markov Chain Monte Carlo method and carried out with Stata14 and OpenBUGS software. Ultimately, the evidentiary grade for the results will be evaluated. RESULTS: Eighteen literatures with a total of 1134 patients were included for the meta-analysis. In glycemia assessment, Tennis (standard mean difference = 3.59, credible interval 1.52, 5.65), had significantly better effects than the named control group. Tennis (standard mean difference = 3.50, credible interval 1.05, 5.59), had significantly better effects than the named Taiji group. CONCLUSION: All together, these results suggest that tennis may be the best way to improve blood glucose in patients with type 2 diabetes. This study may provide an excellent resource for future control glycemia and may also serve as a springboard for creative undertakings as yet unknown.

3.
Biomater Sci ; 2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33913979

RESUMO

Combined antitumor therapies based on nanomedicines have shown efficacy in various tumor models in recent years, overcoming the disadvantages of inefficiency and undesired toxicity of traditional therapies. Herein, we present a copper sulfide- and doxorubicin-loaded gold nanorods@mesoporous SiO2 multifunctional nanocomposite (AuNR@mSiO2@DOX-CuxS-PEG) to integrate chemotherapy, the photothermal properties of AuNRs, and the photodynamic properties of CuxS into a single nanoplatform based on hydrophobic interaction and electrostatic attraction. Upon near-infrared light irradiation, the AuNR@mSiO2@DOX-CuxS-PEG nanocomposites exhibit a synergistic therapeutic effect and inhibit the in situ tumor growth and lung metastasis in a melanoma model. This occurs because of the high photothermal conversion efficiency, boosted intracellular reactive oxygen species production, and excellent doxorubicin (DOX) release, as well as an induced tumor-specific immune response. The inspired antitumor immunity was confirmed by elevated infiltration of activated T cells in tumor tissues and improved maturation and activation of dendritic cells in tumor-draining lymph nodes. This study highlights the superior antitumor therapeutic effect elicited by a multifunctional nanoplatform for skin with in situ melanoma and lung metastasis inhibition, indicating its satisfactory clinical application prospects.

4.
Phys Rev E ; 103(3-1): 032409, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33862816

RESUMO

The mechanical behavior and cortical tension of single cells are analyzed using electrodeformation relaxation. Four types of cells, namely, MCF-10A, MCF-7, MDA-MB-231, and GBM, are studied, with pulse durations ranging from 0.01 to 10 s. Mechanical response in the long-pulse regime is characterized by a power-law behavior, consistent with soft glassy rheology resulting from unbinding events within the cortex network. In the subsecond short-pulse regime, a single timescale well describes the process and indicates the naive tensioned (prestressed) state of the cortex with minimal force-induced alteration. A mathematical model is employed and the simple ellipsoidal geometry allows for use of an analytical solution to extract the cortical tension. At the shortest pulse of 0.01 s, tensions for all four cell types are on the order of 10^{-2} N/m.

5.
Adv Mater ; 33(18): e2100849, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33797149

RESUMO

Gene silencing holds promise for cancer therapeutics because of its potential to inhibit genes involved in tumor development. However, gene silencing is still restricted by its limited efficacy and safety. Nanoscale coordination polymers (CPs) emerge as promising nanocarriers for gene delivery, but their responsiveness and potential therapeutic properties have rarely been explored simultaneously. Here, multifunctional ultrathin 2D nanosheets of Cu(I) 1,2,4-triazolate CP with a thickness of 4.5 ± 0.8 nm are synthesized using a bottom-up method. These CP nanosheets can act as both an effective DNAzyme nanocarrier for gene therapy and an intrinsic photosensitizer for hypoxia-tolerant type I photodynamic therapy (PDT), which is ascribed to the Fenton-like reaction. Because of the glutathione (GSH)-responsiveness of the CP nanosheets, DNAzyme-loaded CP nanosheets exhibit excellent cancer-cell-targeting gene silencing of the early growth response factor-1 (EGR-1), with messenger RNA inhibited by 84% in MCF-7 (human breast cancer cells) and only 6% in MCF-10A (normal human mammary epithelial cells). After tail intravenous injection into MCF-7-tumor-bearing mice, the CP nanosheets loaded with chlorin-e6-modified DNAzyme under photoirradiation show a high antitumor efficacy (88.0% tumor regression), demonstrating a promising therapeutic platform with efficient and selective gene silencing and PDT of cancer.

6.
Stroke Vasc Neurol ; 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33795488

RESUMO

BACKGROUND: Studies show tranexamic acid can reduce the risk of death and early neurological deterioration after intracranial haemorrhage. We aimed to assess whether tranexamic acid reduces haematoma expansion and improves outcome in intracerebral haemorrhage patients susceptible to haemorrhage expansion. METHODS: We did a prospective, double-blind, randomised, placebo-controlled trial at 10 stroke centres in China. Acute supratentorial intracerebral haemorrhage patients were eligible if they had indication of haemorrhage expansion on admission imaging (eg, spot sign, black hole sign or blend sign), and were treatable within 8 hours of symptom onset. Patients were randomly assigned (1:1) to receive either tranexamic acid or a matching placebo. The primary outcome was intracerebral haematoma growth (>33% relative or >6 mL absolute) at 24 hours. Clinical outcomes were assessed at 90 days. RESULTS: Of the 171 included patients, 124 (72.5%) were male, and the mean age was 55.9±11.6 years. 89 patients received tranexamic acid and 82 received placebo. The primary outcome did not differ significantly between the groups: 36 (40.4%) patients in the tranexamic acid group and 34 (41.5%) patients in the placebo group had intracranial haemorrhage growth (OR 0.96, 95% CI 0.52 to 1.77, p=0.89). The proportion of death was lower in the tranexamic acid treatment group than placebo group (8.1% vs 10.0%), but there were no significant differences in secondary outcomes including absolute intracranial haemorrhage growth, death and dependency. CONCLUSIONS: Among patients susceptible to haemorrhage expansion treated within 8 hours of stroke onset, tranexamic acid did not significantly prevent intracerebral haemorrhage growth. Larger studies are needed to assess safety and efficacy of tranexamic acid in intracerebral haemorrhage patients.

7.
Stroke Vasc Neurol ; 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33795489

RESUMO

BACKGROUND AND PURPOSE: Current randomised controlled trials (RCTs) showed an uncertain benefit of haemostatic therapy on preventing haematoma expansion and improving the outcome in patients with intracerebral haemorrhage (ICH). This meta-analysis aims to systematically evaluate the effect of haemostatic agents on the prevention of haemorrhage growth in patients with high-risk spontaneous ICH predicted by CT signs in RCTs. METHODS: A comprehensive search of PubMed, EMBASE and Cochrane library from 1 January 2005 to 30 June 2021 was conducted. RCTs that compared haemostatic agents with placebo for the treatment of spontaneous patients with ICH with high-risk haemorrhage growth were included. The primary endpoint was haematoma expansion at 24 hours. Other major endpoints of interest included 90-day functional outcome and mortality. RESULTS: The meta-analysis included four RCTs that randomised 2666 patients with ICH with high-risk haemorrhage growth. Haemostatic therapy reduced the rate of haematoma expansion at a marginally statistically significant level when compared with placebo (OR 0.84; 95% CI 0.70 to 1.00; p=0.051). Subgroup analysis for patients with black hole sign on CT revealed a significant reduction of haematoma expansion with haemostatic therapy (OR 0.61; 95% CI 0.39 to 0.94; p=0.03). However, both the primary analysis and subgroup analyses showed that haemostatic therapy could not reduce the rate of poor functional outcome (modified Rankin Scale >3) or death. CONCLUSIONS: Haemostatic therapy showed a marginally significant benefit in reducing early haematoma expansion in patients with high-risk spontaneous ICH predicted by markers on CT scan. However, no significant improvement in functional outcome or reduction of mortality was observed.

9.
Talanta ; 226: 122114, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33676670

RESUMO

Nanomaterial-based on-off-on fluorescence sensing strategies are significant particularly in intracellular nucleic acids imaging assay. There still remains challenge to rationally balance fluorescence quenching efficiency and recovery dynamics. We assume that the performance of on-off-on fluorescence sensing strategy can be fundamentally improved on small zero-dimensional (0D) nanomaterial with precisely modulated surface charge. For a proof-of-concept demonstration, silicon nanoparticle (SiNP) with ~4 nm was synthesized and used as the quencher model, of which the surface charge density was modulated by modification of triphenylphosphonium (TPP). The influence of particle size, surface charge and charge density of the nanomaterials on sensing performance was systematically investigated. The strategy showed a low limit of detection (LOD) as 26 pM for target model miR-494, which is one of the lowest in nanomaterial-based on-off-on sensing platforms. And the LOD is even comparable to amplification-based methods in a greatly shortened assay time (2.5 h). The miR-494 expresses in cancerous and normal living cells of human cervical carcinoma (HeLa), human lung carcinoma (A549), human breast cancer (MCF-7), and normal human mammary epithelial (MCF-10A) cells were imaged and localized with significantly improved sensitivity and specificity. These excellent performances insure it a promising candidate as convenient and non-enzymatic sensing platform for miRNA-associated disease detection and early diagnosis.

10.
Aging (Albany NY) ; 13(5): 6525-6553, 2021 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-33690171

RESUMO

The present study was designed to update the knowledge about hypoxia-related multi-omic molecular landscape in hepatocellular carcinoma (HCC) tissues. Large-size HCC datasets from multiple centers were collected. The hypoxia exposure of tumor tissue from patients in 10 HCC cohorts was estimated using a novel HCC-specific hypoxia score system constructed in our previous study. A comprehensive bioinformatical analysis was conducted to compare hypoxia-associated multi-omic molecular features in patients with a high hypoxia score to a low hypoxia score. We found that patients with different exposure to hypoxia differed significantly in transcriptomic, genomic, epigenomic, and proteomic alterations, including differences in mRNA, microRNA (miR), and long non-coding RNA (lncRNA) expression, differences in copy number alterations (CNAs), differences in DNA methylation levels, differences in RNA alternative splicing events, and differences in protein levels. HCC survival- associated molecular events were identified. The potential correlation between molecular features related to hypoxia has also been explored, and various networks have been constructed. We revealed a particularly comprehensive hypoxia-related molecular landscape in tumor tissues that provided novel evidence and perspectives to explain the role of hypoxia in HCC. Clinically, the data obtained from the present study may enable the development of individualized treatment or management strategies for HCC patients with different levels of hypoxia exposure.

11.
Aging (Albany NY) ; 13(6): 9108-9118, 2021 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-33752174

RESUMO

We aim to evaluate the risk of stroke recurrence among non-diabetes mellitus (non-DM), previously diagnosed diabetes mellitus (PDDM), newly diagnosed diabetes mellitus-related hyperglycemia (NDDM-RH) and stress hyperglycemia after minor stroke or TIA. Totally, 3026 patients with baseline fasting glucose and glycated albumin from the CHANCE trial (Clopidogrel in High-Risk Patients with Acute Nondisabling Cerebrovascular Events) were included. Patients were classified as non-DM, PDDM, NDDM-RH and stress hyperglycemia according to the status of glucose metabolism. The primary outcome was stroke recurrence during 90-day follow up. Cox regression was performed to estimate the relationship between the status of glucose metabolism and risk of 90-day stroke recurrence. Compared with PDDM, NDDM-RH had a similar risk of 90-day stroke recurrence (hazard ratios [HR]1.39, 95% confidence intervals [CI] 0.94-2.04), while stress hyperglycemia had approximately a 5.3-fold increased risk of 90-day stroke recurrence after adjusted for confounding covariates (HR 5.32, 95% CI 3.43-8.26). Parallel results were found for 90-day recurrent ischemic stroke and composite events. Compared with PDDM in minor stroke or TIA, a parallel risk of 90-day stroke recurrence were observed for NDDM-RH, while stress hyperglycemia might relate to higher risk of 90-day stroke recurrence.

12.
Bull Environ Contam Toxicol ; 106(5): 786-791, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33787975

RESUMO

The studies on how humic acid (HA) influences the oxidative stress of arsenic in aquatic organism is limited. Using Danio rerio as case study, we explored the oxidative stress effects in aquatic organism after 96 h exposure to the HA and arsenic. Results revealed the co-exposure of HA and arsenite elevated the superoxide dismutase activities and downgraded the malondialdehyde. Thus, we speculate that HA may alleviate the oxidative stress induced by arsenite, which may be caused by the HA's coating in combination with the complexation of arsenite and HA. In addition, HA acted as the reactive oxygen species scavenger, promising to eliminate the oxygen free radicals. Contrastingly, HA may impact little on the arsenate exposure. This study can help better understand oxidative stress mechanism of co-exposure of arsenic and HA in aquatic environment.


Assuntos
Arsênico , Arsenitos , Animais , Arseniatos/toxicidade , Arsenitos/toxicidade , Substâncias Húmicas , Estresse Oxidativo , Peixe-Zebra
13.
Stroke Vasc Neurol ; 2021 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-33727409

RESUMO

BACKGROUNDS: Increased blood pressure (BP) for patients who had an acute ischaemic stroke is associated with poor functional outcome, however the optimal timing of antihypertensive therapy is unknown. AIMS: We aim to compare early antihypertensive treatment to delayed antihypertensive treatment for reducing the risk of composite major disability and mortality at 3 months in acute ischaemic stroke. DESIGN: The China Antihypertensive Trial in Acute Ischemic Stroke II (CATIS-2) trial is a multicentre, randomised, open-label, blinded-endpoints trial that will be conducted in 100 hospitals in China. The primary outcome is the composite of death and major disability (modified Rankin Scale score ≥3) at 3 months of randomisation. Antihypertensive treatment will be received immediately after randomisation in the early treatment group, aimed at average systolic BP by 10%-20% reduction within the first 24 hours, and achieving an average BP level of <140/90 mm Hg within 5 days. Patients in the delayed treatment group will discontinue any antihypertension medications for the first 7 days of randomisation, and will receive antihypertensive therapy achieving a BP goal of <140/90 mm Hg after 7 days. CONCLUSION: The CATIS-2 trial will be testing the hypotheses that early BP lowering leads to improved functional outcome without any other harms, and developing clinical guidelines of the BP management for patients who had an acute ischaemic stroke. TRIAL REGISTRATION NUMBER: NCT03479554.

14.
Stroke ; 52(4): 1473-1477, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33657858

RESUMO

BACKGROUND AND PURPOSE: Intraluminal thrombus (ILT) is an emerging imaging marker in acute ischemic stroke. We aimed to investigate the association of ILT with outcomes of acute large vessel occlusion (LVO) patients receiving endovascular treatment. METHODS: Acute LVO stroke patients who underwent endovascular treatment within 24 hours, in a prospective, nationwide registry were enrolled. Pretreatment digital subtraction angiography was reviewed for the presence of ILT. The primary outcome was 90-day functional dependence (modified Rankin Scale scores, 3-6). Secondary outcomes included 24-hour LVO, 90-day death, and symptomatic intracranial hemorrhage. RESULTS: Among 711 patients enrolled, 75 (10.5%) with ILT were less likely to have 90-day functional dependence compared with those without ILT (adjusted odds ratio, 0.53 [95% CI, 0.31-0.90]; P=0.021). The same trend was found among those with successful reperfusion (modified Thrombolysis in Cerebral Infarction 2b-3; P=0.008) but not in those without successful reperfusion (P=0.107). Presence of ILT was also independently associated with a lower rate of 24-hour LVO (adjusted odds ratio 0.34 [95% CI, 0.13-0.89]; P=0.028). However, those with or without ILT had similar risks of symptomatic intracranial hemorrhage and 90-day death. CONCLUSIONS: Among acute LVO patients receiving endovascular treatment, pretreatment ILT-positive patients may have a better 90-day functional outcome (versus ILT-negative) but similar risk of death and symptomatic intracranial hemorrhage. The possibly favorable effect of ILT patients remained in those with successful reperfusion. Registration: URL: http://www.chictr.org.cn; Unique identifier: ChiCTR1900022154.

15.
Drug Dev Ind Pharm ; : 1-41, 2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33784225

RESUMO

In order to explore the effect of the hollow capsule material formulation on the capsule glue and film formation, this study used hydroxypropylmethylcellulose (HPMC), carrageenan, KCl and Tween 80 as raw materials to determine the production of HPMC hollow capsules suitable formula.The optimal process conditions are as follows: the proportions of HPMC, carrageenan, KCl and Tween 80 in the solvent (purified water) are 18% (m:V), 0.7% (m:V), 0.07% (m:V) and 0.018% (V:V), respectively. Under this condition, the viscosity of the resulting solution, glue solidification temperatureand and gel strength were medium. The resulting film has low hygroscopicity, good solubility, optical properties and mechanical properties. This research can provide data support for the precise formulation and industrial production of HPMC hollow plant capsules.

16.
Bioorg Med Chem Lett ; 40: 127905, 2021 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-33689874

RESUMO

Altered glucose-6-phosphate dehydrogenase (G6PD) status is influential in many cellular pathophysiological processes and diseases, making G6PD a potential target for cancer therapy. However, the available G6PD inhibitors are very limited and restricted. Here we developed a reducing equivalent nicotinamide adenine dinucleotide phosphate (NADPH) absorption photometry assay based on enzyme kinetics to characterize G6PD activity. In this way, we performed a high-throughput screening (HTS) to an in house library. And then we identified compound named Wedelolactone inhibiting G6PD strongly in a non-competitive, reversible way. In addition, we did the surface Plasmon Resonance (SPR) assay and indicated the KD between Wedelolactone and G6PD protein was 3.64 µM. Furthermore, our basic colony formation assay showed the inhibitory effect of Wedelolactone on the proliferation of ovarian cancer cells (IC50 ~ 10 µM). Thus, we provided a high-throughput screening assay to quickly and efficiently discover G6PD inhibitors, and identified Wedelolactone as a G6PD inhibitor, implying that Wedelolactone suppresses ovarian cancer partly through targeting G6PD.

18.
Chem Biol Interact ; 339: 109430, 2021 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-33676887

RESUMO

Connexin-40 (Cx40) and Cx43 are the principal components of gap junctions. Dysregulation of connexin expression is clinically related to cardiac pathologies. 25-Hydroxy protopanaxadiol [25-OH-PPD, 20 (R)-dammarane-3ß, 12ß, 20, 25-tetrol], known as AD2, is a novel protopanaxadiol extracted from Panax ginseng that exhibits many pharmacological activities, but its effects on cardiac gap junctions are poorly understood. The aim of this study was to evaluate the effects of AD2 on angiotensin II (Ang II)-induced Cx40 and Cx43 dysregulation. In this study, isolated beating rat atria were perfused with Ang II (5 µM) for 1 h to induce Cx40 and Cx43 dysregulation. The effects of AD2 (1.6, 16, and 160 µg/100 g body weight) on Ang II-induced hemodynamics in rats were analyzed by biological recorder, and changes in proteins levels were analyzed by western blotting. The results showed that AD2 ameliorated Ang II-induced hyper hemodynamics and abnormal P-waves, and prevented fibrotic collagen deposition (3.77% ± 1.64%-26.31% ± 1.64% with Ang II, 5.76% ± 0.94% with AD2). Ang II upregulated expression of nuclear factor kappa B, activator protein 1, and transforming growth factor ß1, and downregulated of Cx40 and Cx43 expression, which were inhibited by AD2 concomitantly with increased of AMP-activated protein kinase (AMPK) expression via liver kinase B1 activation. The present findings suggest that AD2 inhibited Ang II-induced dysregulation of Cx40 and Cx43 via activation of AMPK signaling, thus highlighting the promise and utility of AD2 for treatment of connexin dysregulation-related heart disease.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Angiotensina II/farmacologia , Conexina 43/metabolismo , Conexinas/metabolismo , Ginsenosídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Regulação para Baixo/efeitos dos fármacos , Fibrose/metabolismo , Junções Comunicantes/efeitos dos fármacos , Junções Comunicantes/metabolismo , Ginsenosídeos/metabolismo , NF-kappa B/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Transcrição AP-1/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Regulação para Cima/efeitos dos fármacos
19.
J Hazard Mater ; 415: 125579, 2021 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-33721782

RESUMO

Although carbon nanomaterials (CNMs) commonly exist throughout the aquatic environment, their effect on arsenic (As) distribution and toxicity is unclear. In this study, arsenite accumulation, transformation, subcellular distribution, and enzyme activity were assessed in adult zebrafish (Danio rerio) intestines, heads and muscles, following co-exposure to arsenite and CNMs with different structures (single-walled carbon nanotubes (SWCNTs), multi-walled carbon nanotubes (MWCNTs), fullerene (C60), graphene oxide (GO), and graphene (GN)). Results show that GN and GO promoted As toxicity in D. rerio, as carriers increasing total As accumulation in the intestine, resulting in arsenite adsorbed by GO and GN being released and transformed mainly into moderately-toxic monomethylarsonic acid (MMA), which was mostly distributed in organelles and metallothionein-like proteins (MTLPs). Moreover, GO and GN influenced As species distribution in D. rerio due to the excellent electron transfer ability. However, the effect was marginal for SWCNT, MWCNT and C60, because of the different structure and suspension stability in fish-culture water. In addition, in the muscle and head tissues, As was mainly distributed in cellular debris in the forms of dimethylarsinic acid (DMA) and arsenobetaine (AsB). These findings help better understand the influence of CNMs on the mechanism of As toxicity in natural aquatic environments.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...