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1.
Cell ; 173(7): 1716-1727.e17, 2018 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-29779945

RESUMO

Sunlight exposure is known to affect mood, learning, and cognition. However, the molecular and cellular mechanisms remain elusive. Here, we show that moderate UV exposure elevated blood urocanic acid (UCA), which then crossed the blood-brain barrier. Single-cell mass spectrometry and isotopic labeling revealed a novel intra-neuronal metabolic pathway converting UCA to glutamate (GLU) after UV exposure. This UV-triggered GLU synthesis promoted its packaging into synaptic vesicles and its release at glutamatergic terminals in the motor cortex and hippocampus. Related behaviors, like rotarod learning and object recognition memory, were enhanced after UV exposure. All UV-induced metabolic, electrophysiological, and behavioral effects could be reproduced by the intravenous injection of UCA and diminished by the application of inhibitor or short hairpin RNA (shRNA) against urocanase, an enzyme critical for the conversion of UCA to GLU. These findings reveal a new GLU biosynthetic pathway, which could contribute to some of the sunlight-induced neurobehavioral changes.


Assuntos
Encéfalo/efeitos da radiação , Ácido Glutâmico/biossíntese , Aprendizagem/efeitos da radiação , Memória/efeitos da radiação , Raios Ultravioleta , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Cromatografia Líquida de Alta Pressão , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Neurônios/citologia , Neurônios/fisiologia , Técnicas de Patch-Clamp , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Espectrometria de Massas em Tandem , Urocanato Hidratase/antagonistas & inibidores , Urocanato Hidratase/genética , Urocanato Hidratase/metabolismo , Ácido Urocânico/sangue , Ácido Urocânico/metabolismo
2.
Proc Natl Acad Sci U S A ; 119(45): e2211228119, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36322742

RESUMO

Magnetic targeting is one of the most promising approaches for improving the targeting efficiency by which magnetic drug carriers are directed using external magnetic fields to reach their targets. As a natural magnetic nanoparticle (MNP) of biological origin, the magnetosome is a special "organelle" formed by biomineralization in magnetotactic bacteria (MTB) and is essential for MTB magnetic navigation to respond to geomagnetic fields. The magnetic targeting of magnetosomes, however, can be hindered by the aggregation and precipitation of magnetosomes in water and biological fluid environments due to the strong magnetic attraction between particles. In this study, we constructed a magnetosome-like nanoreactor by introducing MTB Mms6 protein into a reverse micelle system. MNPs synthesized by thermal decomposition exhibit the same crystal morphology and magnetism (high saturation magnetization and low coercivity) as natural magnetosomes but have a smaller particle size. The DSPE-mPEG-coated magnetosome-like MNPs exhibit good monodispersion, penetrating the lesion area of a tumor mouse model to achieve magnetic enrichment by an order of magnitude more than in the control groups, demonstrating great prospects for biomedical magnetic targeting applications.


Assuntos
Magnetossomos , Magnetospirillum , Nanopartículas , Neoplasias , Camundongos , Animais , Proteínas de Bactérias/metabolismo , Magnetossomos/química , Bactérias Gram-Negativas/metabolismo , Nanopartículas/química , Campos Magnéticos , Neoplasias/metabolismo , Magnetospirillum/metabolismo
3.
Langmuir ; 40(15): 8180-8193, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38581394

RESUMO

Ni-rich layered materials Li[NixCoyMnzAl1-x-y-z]O2 (x > 0.8) are regarded as the competitive cathode for practical applications in lithium-ion batteries owing to the large discharging capacity. Nevertheless, the strong oxidation activity, the poor structure, and the thermal stability at the electrode-electrolyte interface would lead to much trouble, for example, inferior electrochemical properties and acute safety issues. To ameliorate the above problems, this work reports a strategy for the double modification of F- doping and LiNbO3 covering in LiNi0.88Co0.06Mn0.03Al0.03O2 cathode via using high-temperature calcining and ball-milling technology. As a result, the cathodes after F- doping and LiNbO3 covering not only demonstrate a more stabilized crystal structure and particle interface but also reduce the release of high-activity oxygen species to ameliorate the thermal runaway. The electrochemical tests show that the LiNbO3-F--modified cathode displays a superior rate capability of 159.3 mAh g-1 at 10.0 C and has the predominant capability retention of 92.1% in the 200th cycle at 25 °C, much superior than those (125.4 mAh g-1 and 84.0%) of bare cathode. Thus, the F- doped and LiNbO3-coated Ni-rich oxides could be a promising cathode to realize the high capacity and a stabilized interface.

4.
J Appl Clin Med Phys ; 25(4): e14243, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38229472

RESUMO

PURPOSE: To develop a radiotherapy positioning system based on Point Cloud Registration (PCR) and Augmented Reality (AR), and to verify its feasibility. METHODS: The optimal steps of PCR were investigated, and virtual positioning experiments were designed to evaluate its accuracy and speed. AR was implemented by Unity 3D and Vuforia for initial position correction, and PCR for precision registration, to achieve the proposed radiotherapy positioning system. Feasibility of the proposed system was evaluated through phantom positioning tests as well as real human positioning tests. Real human tests involved breath-holding positioning and free-breathing positioning tests. Evaluation metrics included 6 Degree of Freedom (DOF) deviations and Distance (D) errors. Additionally, the interaction between CBCT and the proposed system was envisaged through CBCT and optical cross-source PCR. RESULTS: Point-to-plane iterative Closest Point (ICP), statistical filtering, uniform down-sampling, and optimal sampling ratio were determined for PCR procedure. In virtual positioning tests, a single registration took only 0.111 s, and the average D error for 15 patients was 0.015 ± 0.029 mm., Errors of phantom tests were at the sub-millimeter level, with an average D error of 0.6 ± 0.2 mm. In the real human positioning tests, the average accuracy of breath-holding positioning was still at the sub-millimeter level, where the errors of X, Y and Z axes were 0.59 ± 0.12 mm, 0.54 ± 0.12 mm, and 0.52 ± 0.09 mm, and the average D error was 0.96 ± 0.22 mm. In the free-breathing positioning, the average errors in X, Y, and Z axes were still less than 1 mm. Although the mean D error was 1.93 ± 0.36 mm, it still falls within a clinically acceptable error margin. CONCLUSION: The AR and PCR-guided radiotherapy positioning system enables markerless, radiation-free and high-accuracy positioning, which is feasible in real-world scenarios.


Assuntos
Realidade Aumentada , Humanos , Imageamento Tridimensional/métodos , Estudos de Viabilidade , Imagens de Fantasmas
5.
Langmuir ; 39(13): 4662-4675, 2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-36854144

RESUMO

Mn-based cathode material Li1.20Mn0.52Ni0.20Co0.08O2 was proposed and ameliorated by surface-coating poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and doping Ga3+. X-ray diffraction and high-resolution transmission electron microscopy studies revealed that part of Ga3+ replacing the Ni site could reduce the Li+/Ni2+ mixing by forming a well-ordered layered structure and a homogeneous coating layer of PEDOT:PSS is covered on the surface of Li1.20Mn0.52Ni0.19Co0.08Ga0.01O2. The results of the electrochemical studies demonstrated the higher initial charging-discharging Coulombic efficiency, and outstanding rate capabilities and cyclic performance were obtained for the PEDOT:PSS-covered and Ga3+-doped samples. Especially, 2 wt % PEDOT:PSS-coated Li1.20Mn0.52Ni0.19Co0.08Ga0.01O2 delivered 38.3 mAh g-1, which is larger than the pristine cathode at a 5C high rate. Meanwhile, it could retain 189.6 mAh g-1 (90.3% of its initial discharge capacity at 45 °C) after 300 cycles with a 1C rate, while the pristine cathode only delivered 149.7 mAh g-1 with 80.7% cycling retention left. The results strongly suggested that such PEDOT:PSS-coated and Ga3+-doped Mn-based layered structure materials demonstrated high potential as a cathode candidate especially for high-energy applications.

6.
J Nanobiotechnology ; 21(1): 9, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36609374

RESUMO

As one of the most significant imaging modalities currently available, magnetic resonance imaging (MRI) has been extensively utilized for clinically accurate cancer diagnosis. However, low signal-to-noise ratio (SNR) and low specificity for tumors continue to pose significant challenges. Inspired by the distance-dependent magnetic resonance tuning (MRET) phenomenon, the tumor microenvironment (TME)-activated off-on T1-T2 dual-mode MRI nanoswitch is presented in the current study to realize the sensitive early diagnosis of tumors. The tumor-specific nanoswitch is designed and manufactured on the basis of PDGFB-conjugating ferroferric oxide coated by Mn-doped silica (PDGFB-FMS), which can be degraded under the high-concentration GSH and low pH in TME to activate the T1-T2 dual-mode MRI signals. The tumor-specific off-on dual-mode MRI nanoswitch can significantly improve the SNR and is used successfully for the accurate diagnosis of early-stage tumors, particularly for orthotopic prostate cancer. In addition, the systemic delivery of the nanoswitch did not cause blood or tissue damage, and it can be excreted out of the body in a timely manner, demonstrating excellent biosafety. Overall, the strategy is a significant step in the direction of designing off-on dual-mode MRI nanoprobes to improve imaging accuracy, which opens up new avenues for the development of new MRI probes.


Assuntos
Meios de Contraste , Neoplasias , Masculino , Humanos , Proteínas Proto-Oncogênicas c-sis , Neoplasias/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Dióxido de Silício , Microambiente Tumoral
7.
Small ; 18(15): e2107422, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35233936

RESUMO

Cuprous-based nanozymes have demonstrated great potential for cascade chemodynamic therapy (CDT) due to their higher catalytic efficiency and simple reaction conditions. Here, hollow cuprous oxide@nitrogen-doped carbon (HCONC) dual-shell structures are designed as nanozymes for CDT oncotherapy. This HCONC with a size distribution of 130 nm is synthesized by a one-step hydrothermal method using cupric nitrate and dimethyl formamide as precursors. The thin-layer carbon (1.88 nm) of HCONC enhances the water-stability and reduces the systemic toxicity of cuprous oxide nanocrystals. The dissolved Cu+ of HCONC in acid solution induces a Fenton-like reaction and exhibits a fast reaction rate for catalyzing H2 O2 into highly toxic hydroxyl radicals (·OH). Meanwhile, the formed Cu+ consumes oversaturated glutathione (GSH) to avoid its destruction of ROS at the intracellular level. In general, both cellular and animal experiments show that HCONC demonstrates excellent antitumor ability without causing significant systemic toxicity, which may present tremendous potential for clinical cancer therapy.


Assuntos
Nanocápsulas , Neoplasias , Animais , Carbono , Linhagem Celular Tumoral , Cobre , Glutationa/química , Peróxido de Hidrogênio/química , Neoplasias/tratamento farmacológico , Nitrogênio
8.
BMC Cancer ; 22(1): 885, 2022 Aug 13.
Artigo em Inglês | MEDLINE | ID: mdl-35964070

RESUMO

BACKGROUND: Pyroptosis is a programmed cell death mediated by the gasdermin superfamily, accompanied by inflammatory and immune responses. Exogenously activated pyroptosis is still not well characterized in the tumor microenvironment. Furthermore, whether pyroptosis-related genes (PRGs) in lower-grade glioma (LGG) may be used as a biomarker remains unknown. METHODS: The RNA-Sequencing and clinical data of LGG patients were downloaded from publicly available databases. Bioinformatics approaches were used to analyze the relationship between PRGs and LGG patients' prognosis, clinicopathological features, and immune status. The NMF algorithm was used to differentiate phenotypes, the LASSO regression model was used to construct prognostic signature, and GSEA was used to analyze biological functions and pathways. The expression of the signature genes was verified using qRT-PCR. In addition, the L1000FWD and CMap tools were utilized to screen potential therapeutic drugs or small molecule compounds and validate their effects in glioma cell lines using CCK-8 and colony formation assays. RESULTS: Based on PRGs, we defined two phenotypes with different prognoses. Stepwise regression analysis was carried out to identify the 3 signature genes to construct a pyroptosis-related signature. After that, samples from the training and test cohorts were incorporated into the signature and divided by the median RiskScore value (namely, Risk-H and Risk-L). The signature shows excellent predictive LGG prognostic power in the training and validation cohorts. The prognostic signature accurately stratifies patients according to prognostic differences and has predictive value for immune cell infiltration and immune checkpoint expression. Finally, the inhibitory effect of the small molecule inhibitor fedratinib on the viability and proliferation of various glioma cells was verified using cell biology-related experiments. CONCLUSION: This study developed and validated a novel pyroptosis-related signature, which may assist instruct clinicians to predict the prognosis and immunological status of LGG patients more precisely. Fedratinib was found to be a small molecule inhibitor that significantly inhibits glioma cell viability and proliferation, which provides a new therapeutic strategy for gliomas.


Assuntos
Neoplasias Encefálicas , Glioma , Neoplasias Encefálicas/patologia , Perfilação da Expressão Gênica , Glioma/patologia , Humanos , Prognóstico , Piroptose/genética , Microambiente Tumoral/genética
9.
BMC Gastroenterol ; 22(1): 211, 2022 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35501704

RESUMO

BACKGROUND: This study aimed to determine the prognostic value of the sarcopenia on the progression free survival (PFS) and overall survival (OS) of esophageal squamous cell cancer (ESCC) patients who received radiotherapy (RT) or chemoradiotherapy (CRT). METHODS: Data on clinicopathological characteristics and nutritional parameters were analyzed and correlated with PFS and OS, retrospectively. Skeletal muscle, subcutaneous, visceral and total fat tissue cross-sectional areas were evaluated on CT images at the midpoint of the 3rd lumbar vertebrae. A total of 213 patients were enrolled in this study. RESULTS: Sarcopenia was significantly associated with subcutaneous fat content. The univariate analysis demonstrated that OS was superior in patients with non-sarcopenia, non-alcohol, NRI ≥ 100, albumin ≥ 40 g/L, TATI > 83.0, SATI > 27.8, VATI > 49, non-anemia, cervical and upper-thoracic ESCC, T stage 1-2, N stage 0-1 and TNM stage I-II. In the multivariate analysis, sarcopenia, albumin, N stage and TNM stage were identified as independent prognostic factors of survival. This study demonstrated that sarcopenia was related to worse PFS and OS in patients with ESCC who received RT or CRT. CONCLUSIONS: Sarcopenia is considered to be a useful predictor in patients with ESCC who received RT or CRT. This study also provided a conceptual basis for further prospective research on the application of the sarcopenia for patients receiving RT or CRT for intermediate- and advanced-stage ESCC.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Esofágicas , Carcinoma de Células Escamosas do Esôfago , Sarcopenia , Albuminas , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia/efeitos adversos , Células Epiteliais , Neoplasias Esofágicas/complicações , Neoplasias Esofágicas/terapia , Carcinoma de Células Escamosas do Esôfago/patologia , Carcinoma de Células Escamosas do Esôfago/terapia , Humanos , Prognóstico , Estudos Retrospectivos , Sarcopenia/diagnóstico por imagem , Sarcopenia/etiologia
10.
Small ; 17(31): e2100794, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34165871

RESUMO

Phototherapy in the second near-IR (1000-1700 nm, NIR-II) window has achieved much progress because of its high efficiency and relatively minor side effects. In this paper, a new NIR-II responsive hollow magnetite nanocluster (HMNC) for targeted and imaging-guided cancer therapy is reported. The HMNC not only provides a hollow cavity for drug loading but also serves as a contrast agent for tumor-targeted magnetic resonance imaging. The acid-induced dissolution of the HMNCs can trigger a pH-responsive drug release for chemotherapy and catalyze the hydroxyl radical (·OH) formation from the decomposition of hydrogen peroxide for chemodynamic therapy. Moreover, the HMNCs can adsorb and convert NIR-II light into local heat (photothermal conversion efficacy: 36.3%), which can accelerate drug release and enhance the synergistic effect of chemo-photothermal therapy. The HMNCs show great potential as a versatile nanoplatform for targeted imaging-guided trimodal cancer therapy.


Assuntos
Hipertermia Induzida , Nanopartículas , Doxorrubicina , Liberação Controlada de Fármacos , Óxido Ferroso-Férrico , Imageamento por Ressonância Magnética , Fototerapia
11.
Nanotechnology ; 33(11)2021 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-34768251

RESUMO

Photocatalytic conversion of carbon dioxide into fuels and valuable chemicals is a promising method for carbon neutralization and solving environmental problems. Through a simple thermal-oxidative exfoliation method, the O element was doped while exfoliated bulk g-C3N4into ultrathin structure g-C3N4. Benefitting from the ultrathin structure of g-C3N4, the larger surface area and shorter electrons migration distance effectively improve the CO2reduction efficiency. In addition, density functional thory computation proves that O element doping introduces new impurity energy levels, which making electrons easier to be excited. The prepared photocatalyst reduction of CO2to CO (116µmol g-1h-1) and CH4(47µmol g-1h-1).

12.
J Nanobiotechnology ; 19(1): 227, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-34330298

RESUMO

The cell membrane is widely considered as a promising delivery nanocarrier due to its excellent properties. In this study, self-assembled Pseudomonas geniculate cell membranes were prepared with high yield as drug nanocarriers, and named BMMPs. BMMPs showed excellent biosafety, and could be more efficiently internalized by cancer cells than traditional red cell membrane nanocarriers, indicating that BMMPs could deliver more drug into cancer cells. Subsequently, the BMMPs were coated with nanoselenium (Se), and subsequently loaded with Mn2+ ions and doxorubicin (DOX) to fabricate a functional nanoplatform (BMMP-Mn2+/Se/DOX). Notably, in this nanoplatform, Se nanoparticles activated superoxide dismutase-1 (SOD-1) expression and subsequently up-regulated downstream H2O2 levels. Next, the released Mn2+ ions catalyzed H2O2 to highly toxic hydroxyl radicals (·OH), inducing mitochondrial damage. In addition, the BMMP-Mn2+/Se nanoplatform inhibited glutathione peroxidase 4 (GPX4) expression and further accelerated intracellular reactive oxygen species (ROS) generation. Notably, the BMMP-Mn2+/Se/DOX nanoplatform exhibited increased effectiveness in inducing cancer cell death through mitochondrial and nuclear targeting dual-mode therapeutic pathways and showed negligible toxicity to normal organs. Therefore, this nanoplatform may represent a promising drug delivery system for achieving a safe, effective, and accurate cancer therapeutic plan.


Assuntos
Biomimética , Doxorrubicina/farmacologia , Manganês/farmacologia , Mitocôndrias/metabolismo , Nanopartículas , Selênio/química , Antineoplásicos/farmacologia , Biomassa , Linhagem Celular Tumoral , Sistemas de Liberação de Medicamentos , Tratamento Farmacológico , Células HeLa , Humanos , Peróxido de Hidrogênio/metabolismo , Íons , Fosfolipídeo Hidroperóxido Glutationa Peroxidase , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase-1
13.
Sheng Wu Yi Xue Gong Cheng Xue Za Zhi ; 38(5): 1003-1009, 2021 Oct 25.
Artigo em Zh | MEDLINE | ID: mdl-34713669

RESUMO

Bionic untethered micro-nano robots, due to their advantages of small size, low weight, large thrust-to-weight ratio, strong wireless mobility, high flexibility and high sensitivity, have very important application values in the fields of biomedicine, such as disease diagnosis, minimally invasive surgery, targeted therapy, etc. This review article systematically introduced the manufacturing methods and motion control, and discussed the biomedical applications of bionic untethered micro-nano robots. Finally, the article discussed the possible challenges for bionic untethered micro-nano robots in the future. In summary, this review described bionic untethered micro-nano robots and their potential applications in biomedical fields.


Assuntos
Biônica , Robótica , Desenho de Equipamento , Procedimentos Cirúrgicos Minimamente Invasivos , Movimento (Física)
14.
Int J Neurosci ; 130(2): 153-160, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31516042

RESUMO

Purpose: Parkinson's disease is a progressive disorder. To investigate the biochemical alterations in the striatum of rats with different stages of Parkinson's disease induced by proteasomal inhibition, we quantified neurochemical profiles of the striatum using proton magnetic resonance spectroscopyusing 9.4 T ultra-high field imaging.Methods: In this study, 10 µg/2 µl lactacystin, a selective proteasome inhibitor, was unilaterally injected stereotaxically into the left substantia nigra pars compacta of rats. An equal volume of saline was injected into the same region and side in the control group. Changes in motor behaviour were observed. The morphological changes of tyrosine hydroxylase-positive cells in substantia nigra pars compacta were visualized using immunohistochemistry. Tyrosine hydroxylase-positive nerve fibers were quantified. Alterations of N-acetylaspartate, choline, creatine, taurine in the different stages of Parkinson's disease rats were detected using proton magnetic resonance spectroscopy.Results: Application of in vivo 1H magnetic resonance spectroscopy was repeated in both the six Parkinson's disease rats and the six control rats across three time points during the first, second and fourth weekend after administration. In Parkinson's disease rats, increased N-acetylaspartate and decreased taurine concentrations were observed in the left striatum at the first week after administration. The increased N-acetylaspartate and choline concentrations were observed at the second weekend. At the fourth weekend, increased creatine concentrations in the left side were observed, while other metabolites were not significantly changed.Conclusions: Neurochemical alterations occurred in the striatum during different stages of the Parkinson's disease model in rats. Also, 9.4 T 1H magnetic resonance spectroscopy may be a useful tool for elucidating the progression of Parkinson's disease through the variation of these metabolites.


Assuntos
Corpo Estriado/metabolismo , Doença de Parkinson/metabolismo , Inibidores de Proteases/farmacologia , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Animais , Corpo Estriado/diagnóstico por imagem , Corpo Estriado/efeitos dos fármacos , Modelos Animais de Doenças , Masculino , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson Secundária/induzido quimicamente , Doença de Parkinson Secundária/metabolismo , Espectroscopia de Prótons por Ressonância Magnética , Ratos , Ratos Sprague-Dawley
15.
Fish Shellfish Immunol ; 92: 367-376, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31200070

RESUMO

Oxidative stress plays a crucial role in ammonia nitrogen toxicity. In this study, the beneficial effects of dietary nano cerium oxide (nano CeO2) as a potent antioxidant were examined in the Chinese mitten crab (Eriocheir sinensis). Crabs were fed a diet supplemented with 0, 0.2, 0.4, 0.8, 1.6, 3.2, 6.4, or 12.8 mg/kg nano CeO2 for 60 d. The optimum supplementation level of nano CeO2 that significantly increased weight gain rate and decreased feed coefficient was 0.8 mg/kg. This level also offered immune protection when crabs were kept under ammonia nitrogen stress and/or exposed to pathogen infection (Aeromonas hydrophila). Supplementation with 0.8 mg/kg of CeO2 (i) relieved pathological damage to the hepatopancreas; (ii) increased hemocyte counts, including total number of hemocytes, granulocytes, and hyalinocytes; (iii) decreased malondialdehyde content and increased antioxidant enzyme activities of superoxide dismutase and catalase in the hemolymph; (iv) increased the activities of lysozyme, acid phosphatase, and alkaline phosphatase in the hemolymph; and (v) increased gene and protein expression of cathepsin L in the hepatopancreas. Mortality increased when crabs were injected with bacteria under ammonia nitrogen stress, but dietary supplementation with 0.8 mg/kg nano CeO2 decreased the mortality rate. Thus, the results of this study suggested that dietary supplementation with nano CeO2 in crabs promoted growth and up-regulated immunity to bacterial infection under ammonia nitrogen stress.


Assuntos
Amônia/efeitos adversos , Braquiúros/efeitos dos fármacos , Cério/metabolismo , Imunidade Inata/efeitos dos fármacos , Nanopartículas Metálicas , Estresse Oxidativo/efeitos dos fármacos , Ração Animal/análise , Animais , Braquiúros/crescimento & desenvolvimento , Braquiúros/imunologia , Braquiúros/fisiologia , Cério/administração & dosagem , Cério/farmacologia , Dieta , Suplementos Nutricionais/análise , Relação Dose-Resposta a Droga , Nanopartículas Metálicas/administração & dosagem , Distribuição Aleatória
16.
J Nanobiotechnology ; 17(1): 41, 2019 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-30894193

RESUMO

BACKGROUND: Cerium oxide nanoparticles (CeO2 NPs) have potential application for use in biomedical and in various consumer products. However, it is largely unclear whether CeO2 NPs have effects on male reproductive function. METHODS: In this study, male mice were examined for toxicity, if any, following chronic oral administration of CeO2 NPs for 32 days. In each animal, epididymides were examined for sperm motility and DNA integrity. Bloods were tested for testosterone levels. Testicular tissues were collected to determine the element Ce content, the daily sperm production (DSP), marker enzymes such as ACP, G6PD, γ-GT and SDH, mRNA expression levels of steroidogenesis genes Star, P450scc, P450c17, 3ß-Hsd, and 17ß-Hsd, as well as steroidogenic factor-1 (SF-1) gene/protein levels. RESULTS: The results showed that CeO2 NPs (20 mg/kg and 40 mg/kg) increased the element Ce content in testis, the testis histopathological patterns and sperm DNA damage whereas decreased the testis weight, DSP and sperm motility. There were also remarkable reduction in testosterone levels and marker enzymes activities, down-regulated mRNA expression levels of several steroidogenesis genes such as Star, P450scc, P450c17, 3ß-Hsd, and 17ß-Hsd, as well as altered gene and protein expressions of SF-1. CONCLUSION: These results reveal the male reproductive toxicity of chronic exposure of CeO2 NPs in mice, hinting that the utilization of CeO2 NPs need to be carefully evaluated about their potential reproductive toxicity on the human health.


Assuntos
Cério/química , Nanopartículas Metálicas/toxicidade , Reprodução/efeitos dos fármacos , Fator Esteroidogênico 1/metabolismo , Animais , Cério/toxicidade , Dano ao DNA , Regulação da Expressão Gênica , Masculino , Camundongos Endogâmicos C57BL , Tamanho da Partícula , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/anormalidades , Fator Esteroidogênico 1/genética
17.
Mikrochim Acta ; 186(11): 737, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31673790

RESUMO

A self-powered photoelectrochemical (PEC) aptamer probe is presented for the determination of oxytetracycline (OTC). The assay is based on the use of g-C3N4 and NiO nanocrystals (NCs) which form a heterojunction. The latter was prepared by two-step hydrothermal pyrolysis by using the ionic liquid 1-hydroxyethyl-3-methylimidazole chloride which functions as a morphological template to form NiO NCs. The heterojunction exhibits much better electronic conductivity, wider absorption range, higher electron-hole-separation productivity, and stronger photocurrent compared to plain g-C3N4. The heterojunction was adopted to construct a self-powered PEC aptamer probe for OTC detection. An OTC-binding aptamer was immobilized on the heterojunction and the probe was constructed. The aptamer on the probe binding with OTC can form steric hindrance for transmitting of electrons and cause the PEC signal change depending on the OTC concentration. The photocurrent decreases with increasing OTC concentration in the 0.01 to 100 nM concentration range and its detection limit is 4 pM (at S/N = 3). Graphical abstract Schematic representation of a self-powered photochemical aptamer probe. The probe performs enhanced ability for oxytetracycline (OTC) determination due to the formation of NiO nanocrystals/g-C3N4 (NiO NCs/g-C3N4) heterojunction and the specification recognition of the aptamer.

18.
Mikrochim Acta ; 186(12): 794, 2019 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-31734780

RESUMO

A photoelectrochemical (PEC) aptasensor is described for detecting tetracycline (TC). A gold nanoparticles/BiOBr (AuNPs/BiOBr) composite was prepared where the AuNPs play a key function in carrier transfer which is ascribed to the wavelength-dependent dual function as an electron sink and as a hot-electron donor. Due to this dual function, the composite exhibits a wide photo-response and high electron transfer efficiency. This results in enormously enhanced PEC response. The TC-aptamer was immobilized on an ITO modified with AuNPs/BiOBr via Au-S covalent bonding. The resulting PEC aptasensor possesses a wide linear range (1-104 ng L-1) and a low detection limit (0.35 ng L-1; at S/N = 3). Graphical abstractSchematic representation of a photoelectrochemical aptasensor for tetracycline based on the use of a AuNP/BiOBr composite with electron sink and hot-electron donor properties of the gold nanoparticles.


Assuntos
Aptâmeros de Nucleotídeos/química , Técnicas Biossensoriais/métodos , Bismuto/química , Técnicas Eletroquímicas/métodos , Nanopartículas Metálicas/química , Tetraciclina/análise , Antibacterianos/análise , Antibacterianos/química , Ouro/química , Limite de Detecção , Nanocompostos/química , Nanocompostos/efeitos da radiação , Reprodutibilidade dos Testes , Tetraciclina/química , Raios Ultravioleta
19.
Magn Reson Med ; 80(1): 200-210, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29193266

RESUMO

PURPOSE: A new diffusion-mapping method based on single-shot overlapping-echo detachment (DM-OLED) planar-imaging sequence, along with a corresponding separation algorithm, is proposed to achieve reliable quantitative diffusion mapping in a single shot. The method can resist the effects of motion and help in detecting the quick variation of diffusion under different physiological status. METHODS: The echo-planar imaging method is combined with two excitation pulses with small flip angle to gain overlapping-echo signal in a single shot. Then the overlapping signals are separated by a separation algorithm and used for diffusion computation. Numerical simulation, phantom, and in vivo rat experiments were performed to verify the efficiency, accuracy, and motion tolerance of DM-OLED. RESULTS: The DM-OLED sequence could obtain reliable diffusion maps within milliseconds in numerical simulation, phantom, and in vivo experiments. Compared with conventional diffusion mapping with spin-echo echo-planar imaging, DM-OLED has higher time resolution and fewer motion-incurred errors in the apparent diffusion coefficient maps. CONCLUSIONS: As a reliable fast diffusion measurement tool, DM-OLED shows promise for real-time dynamic diffusion mapping and functional magnetic resonance imaging. Magn Reson Med 80:200-210, 2018. © 2017 International Society for Magnetic Resonance in Medicine.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Imagem Ecoplanar/métodos , Algoritmos , Animais , Encéfalo/diagnóstico por imagem , Simulação por Computador , Análise de Fourier , Hemodinâmica , Hipocampo/diagnóstico por imagem , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética , Modelos Teóricos , Movimento (Física) , Imagens de Fantasmas , Ratos
20.
Inorg Chem ; 57(23): 14532-14541, 2018 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-30451498

RESUMO

The development of an artificial model of photoinduced hydrogen production system requires efficient, long-term stability and cost-competitive photocatalysts to store solar energy in chemical bonds. However, the existing photocatalysts still suffer from the high cost, high recombination rate of photoexcited electron-hole pairs, and poor photostability. Herein, we demonstrate the synthesis of a p-type CuO/n-type CeO2 heterojunction in situ grown on graphene via a hypha assistance process. Amazingly, optical and photoelectrochemical measurements show the superiority of this hierarchically biomorphic structure. The observed H2 evolution rate of the CeO2-CuO quantum dots/graphene has reached 2481 µmol·h-1·g-1 and remains unchanged in four hydrogen production cycles. Considering the convenience of microbial culture, this heterostructure system has great potential as a photocatalyst for solar-fuel conversion.

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