Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 245
Filtrar
1.
Nat Chem Biol ; 20(10): 1272-1281, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38783134

RESUMO

Fluorescent RNAs (FRs) provide an attractive approach to visualizing RNAs in live cells. Although the color palette of FRs has been greatly expanded recently, a green FR with high cellular brightness and photostability is still highly desired. Here we develop a fluorogenic RNA aptamer, termed Okra, that can bind and activate the fluorophore ligand ACE to emit bright green fluorescence. Okra has an order of magnitude enhanced cellular brightness than currently available green FRs, allowing the robust imaging of messenger RNA in both live bacterial and mammalian cells. We further demonstrate the usefulness of Okra for time-resolved measurements of ACTB mRNA trafficking to stress granules, as well as live-cell dual-color superresolution imaging of RNA in combination with Pepper620, revealing nonuniform and distinct distributions of different RNAs throughout the granules. The favorable properties of Okra make it a versatile tool for the study of RNA dynamics and subcellular localization.


Assuntos
Corantes Fluorescentes , RNA Mensageiro , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Mensageiro/química , Humanos , Corantes Fluorescentes/química , Aptâmeros de Nucleotídeos/química , Aptâmeros de Nucleotídeos/metabolismo , Microscopia de Fluorescência/métodos
2.
J Cell Mol Med ; 28(8): e18178, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38553964

RESUMO

Bergamot essential oil (BEO) is an extract of the bergamot fruit with significant neuroprotective effect. This study was to investigate the effects and the underlying mechanism of BEO in mitigating depression. GC-MS were used to identify its constituents. Antidepressive properties of BEO were evaluated by sucrose preference test (SPT), force swimming test (FST) and open field test (OFT). Nissl staining was used to determine the number of Nissl bodies in hippocampus (HIPP) of rats. Changes in HIPP dendritic length and dendritic spine density were detected by Golgi-Cox staining. Immunohistochemistry and Western blot were used to detect the postsynaptic density protein-95 (PSD-95) and synaptophysin (SYP) in the HIPP of rats. The enzyme-linked immunosorbent assay was used to determine the 5-hydroxytryptamine (5-HT), insulin-like growth factor 1 (IGF-1) and interleukin-1ß (IL-1ß) in the HIPP, serum and cerebrospinal fluid (CSF) of rats. Inhaled BEO significantly improved depressive behaviour in chronic unpredictable mild stress (CUMS) rats. BEO increased Nissl bodies, dendritic length and spine density, PSD-95 and SYP protein in the HIPP. Additionally, BEO upregulated serum 5-HT, serum and CSF IGF-1, while downregulating serum IL-1ß. Collectively, inhaled BEO mitigates depression by protecting the plasticity of hippocampal neurons, hence, providing novel insights into treatment of depression.


Assuntos
Depressão , Óleos Voláteis , Ratos , Animais , Depressão/tratamento farmacológico , Depressão/etiologia , Depressão/metabolismo , Óleos Voláteis/farmacologia , Óleos Voláteis/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Serotonina/metabolismo , Hipocampo/metabolismo , Proteína 4 Homóloga a Disks-Large/metabolismo , Neurônios/metabolismo , Estresse Psicológico/complicações , Estresse Psicológico/tratamento farmacológico , Modelos Animais de Doenças , Comportamento Animal
3.
Biochem Biophys Res Commun ; 710: 149856, 2024 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-38583234

RESUMO

The topological properties of DNA have long been a focal point in biophysics. In the 1970s, White proposed that the topology of closed DNA double helix follows White's formula: Lk=Wr+Tw. However, there has been controversy in the calculation of DNA twisting number, partly due to discrepancies in the definition of torsion in differential geometry. In this paper, we delved into a detailed study of torsion, revealing that the calculation of DNA twisting number should use the curve's geodesic torsion. Furthermore, we found that the discrepancy in DNA twisting numbers calculated using different torsion is N. This study elucidated the impact of torsion on the calculation of DNA twisting numbers, aiming to resolve controversies in the calculation of DNA topology and provided accurate computational methods and theoretical foundations for related research.


Assuntos
DNA , Conformação de Ácido Nucleico , DNA/genética , Matemática , Biofísica
4.
Chemistry ; : e202402972, 2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39243153

RESUMO

Developing efficient bifunctional oxygen electrocatalysts is crucial for enhancing the performance of rechargeable Zn-air batteries (ZABs). In this study, cobalt/cobalt oxides embedded in N-doped carbon nanofibers (Co/CoOx/NCNFs) were synthesized through a combination of electrospinning and annealing processes. The resulting Co/CoOx/NCNFs catalysts feature abundant CoNx and CoOx active species, leveraging the large specific surface area of nanofibers to facilitate oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). The optimized Co/CoOx/NCNFs-0.1 achieved a half-wave potential (vs. RHE) of 0.82 V and required only 429 mV to reach 10 mA cm-2 in a typical three-electrode system with 0.1 M KOH using an electrochemical workstation equipped with a pine instruments rotator, outperforming the Pt/C+RuO2. The assembled ZABs exhibited high specific capacity (771 mAh gZn -1), substantial power density (981.6 mWh gZn -1), and long-term stability (>325 h). In situ Raman spectroscopy confirmed that the electrocatalytic processes involve the redox activity of Co (II and III) species derived from abundant CoNx and CoOx, elaborating the origin of the catalysts' exceptional oxygen electrocatalysis performance. This work not only presents a straightforward and effective approach for producing bifunctional oxygen electrocatalysts in ZABs but also sheds light on the catalytic mechanisms underlying ORR and OER for CoNx/CoOx-based oxygen electrocatalysts.

5.
Langmuir ; 40(24): 12419-12426, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38836381

RESUMO

Recently, polyurethane elastomer (TPU) has attracted more and more attention depending on its excellent optical, mechanical, and retreatment properties. The high strength of polyurethane has always been pursued, which can enable its application in more fields. In this work, an aliphatic polyurethane elastomer membrane (HRPU6) was successfully synthesized, and its strength was obviously improved by solvent annealing technology. The tensile strength and adhesion strength can reach 64.56 and 2.58 MPa, but 36.55 and 1.57 MPa only before solvent annealing, respectively. The impact strength of laminated glass based on HRPU has also been significantly improved after solvent annealing, confirmed through drop ball impact testing. It has been confirmed that the increase in strength of HRPU6 is attributed to the enhancement of hydrogen bonding and the improvement of the phase separation degree.

6.
Chem Rec ; 24(1): e202300088, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37098879

RESUMO

CoP nanomaterials have been extensively regarded as one of the most promising electrocatalysts for overall water splitting due to their unique bifunctionality. Although the great promise for future applications, some important issues should also be addressed. Heteroatom doping has been widely acknowledged as a potential strategy for improving the electrocatalytic performance of CoP and narrowing the gap between experimental study and industrial applications. Recent years have witnessed the rapid development of heteroatom-doped CoP electrocatalysts for water splitting. Aiming to provide guidance for the future development of more effective CoP-based electrocatalysts, we herein organize a comprehensive review of this interesting field, with the special focus on the effects of heteroatom doping on the catalytic performance of CoP. Additionally, many heteroatom-doped CoP electrocatalysts for water splitting are also discussed, and the structure-activity relationship is also manifested. Finally, a systematic conclusion and outlook is well organized to provide direction for the future development of this interesting field.

7.
J Org Chem ; 89(21): 15822-15833, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39420776

RESUMO

Herein, we report a general and efficient Ni-catalyzed reductive cross-coupling reaction of substituted vinyl bromides and α-chloro phosphonates to access a set of α-vinyl phosphonates using zinc as the terminal reductant. This reaction exhibits broad substrate adaptability and good functional group tolerance, which allows to afford diverse compounds including structurally complex motifs from natural products and drugs. Furthermore, the practicality was certificated through the gram-scale and transformation experiments. The preliminary mechanistic investigations support a radical chain process. The potential to realize enantiomeric control makes it more valuable for further exploration.

8.
Postgrad Med J ; 100(1186): 592-602, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-38507237

RESUMO

PURPOSE: To construct a clinical noncontrastive computed tomography (NCCT) deep learning joint model for predicting early hematoma expansion (HE) after cerebral hemorrhage (sICH) and evaluate its predictive performance. METHODS: All 254 patients with primary cerebral hemorrhage from January 2017 to December 2022 in the General Hospital of the Western Theater Command were included. According to the criteria of hematoma enlargement exceeding 33% or the volume exceeding 6 ml, the patients were divided into the HE group and the hematoma non-enlargement (NHE) group. Multiple models and the 10-fold cross-validation method were used to screen the most valuable features and model the probability of predicting HE. The area under the curve (AUC) was used to analyze the prediction efficiency of each model for HE. RESULTS: They were randomly divided into a training set of 204 cases in an 8:2 ratio and 50 cases of the test set. The clinical imaging deep feature joint model (22 features) predicted the area under the curve of HE as follows: clinical Navie Bayes model AUC 0.779, traditional radiology logistic regression (LR) model AUC 0.818, deep learning LR model AUC 0.873, and clinical NCCT deep learning multilayer perceptron model AUC 0.921. CONCLUSION: The combined clinical imaging deep learning model has a high predictive effect for early HE in sICH patients, which is helpful for clinical individualized assessment of the risk of early HE in sICH patients.


Assuntos
Hemorragia Cerebral , Aprendizado Profundo , Hematoma , Tomografia Computadorizada por Raios X , Humanos , Hemorragia Cerebral/diagnóstico por imagem , Masculino , Hematoma/diagnóstico por imagem , Feminino , Pessoa de Meia-Idade , Idoso , Valor Preditivo dos Testes , Modelos Logísticos , Progressão da Doença , Teorema de Bayes
9.
Proc Natl Acad Sci U S A ; 118(46)2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34772807

RESUMO

Chronic infection with liver flukes (such as Clonorchis sinensis) can induce severe biliary injuries, which can cause cholangitis, biliary fibrosis, and even cholangiocarcinoma. The release of extracellular vesicles by C. sinensis (CsEVs) is of importance in the long-distance communication between the hosts and worms. However, the biological effects of EVs from liver fluke on biliary injuries and the underlying molecular mechanisms remain poorly characterized. In the present study, we found that CsEVs induced M1-like activation. In addition, the mice that were administrated with CsEVs showed severe biliary injuries associated with remarkable activation of M1-like macrophages. We further characterized the signatures of miRNAs packaged in CsEVs and identified a miRNA Csi-let-7a-5p, which was highly enriched. Further study showed that Csi-let-7a-5p facilitated the activation of M1-like macrophages by targeting Socs1 and Clec7a; however, CsEVs with silencing Csi-let-7a-5p showed a decrease in proinflammatory responses and biliary injuries, which involved in the Socs1- and Clec7a-regulated NF-κB signaling pathway. Our study demonstrates that Csi-let-7a-5p delivered by CsEVs plays a critical role in the activation of M1-like macrophages and contributes to the biliary injuries by targeting the Socs1- and Clec7a-mediated NF-κB signaling pathway, which indicates a mechanism contributing to biliary injuries caused by fluke infection. However, molecules other than Csi-let-7a-5p from CsEVs that may also promote M1-like polarization and exacerbate biliary injuries are not excluded.


Assuntos
Vesículas Extracelulares/metabolismo , Fasciola hepatica/metabolismo , Macrófagos/metabolismo , Animais , Camundongos , Camundongos Endogâmicos C57BL , MicroRNAs/metabolismo , NF-kappa B/metabolismo , Infecção Persistente/parasitologia , Transdução de Sinais/fisiologia
10.
Yi Chuan ; 46(2): 92-108, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38340001

RESUMO

Fluorescent RNA is a kind of emerging RNA labeling technique that can be used for in situ labeling and imaging of RNA in live cells, which plays an important role in understanding the function and regulation mechanism of RNA. Biosensing technology based on fluorescent RNA can be applied in dynamic detection of small molecule metabolites and proteins in real time, offering valuable tools for basic life science research and biomedical sensing technology development. In this review, we introduce the development of genetically encoded fluorescent RNA, and the application of fluorescent RNA in RNA imaging and biosensing technology based on fluorescent RNA in biosensing in live cell. Meanwhile, we discuss the direction and challenge of future development of fluorescent RNA technology to provide valuable insights for further development and application of this technology in relevant fields.


Assuntos
Técnicas Biossensoriais , RNA , Técnicas Biossensoriais/métodos , Proteínas , Corantes Fluorescentes
11.
Pak J Pharm Sci ; 37(1): 139-145, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38741410

RESUMO

Liposomes, a nanoscale carrier, plays an important role in the delivery of drug, affects the in vivo efficacy of drugs. In this paper, silymarin(SM)-loaded liposomes was optimized using the response surface method (RSM), with entrapment efficiency (EE%) as an index. The formulation was optimized as follow: lecithin (7.8mg/mL), SM/lecithin (1/26) and lecithin/cholesterol (10/1). The optimized SM liposomes had a high EE (96.58 ±3.06%), with a particle size of 290.3 ±10.5nm and a zeta potential of +22.98 ±1.73mV. In vitro release tests revealed that SM was released in a sustained-release manner, primarily via diffusion mechanism. In vitro cytotoxicity studies demonstrated that the prepared SM liposomes had stronger inhibitory effects than the model drug. Overall, these results indicate that this liposome system is suitable for intravenous delivery to enhance the antitumor effects of SM.


Assuntos
Lecitinas , Lipossomos , Tamanho da Partícula , Silimarina , Silimarina/farmacologia , Silimarina/química , Silimarina/administração & dosagem , Humanos , Lecitinas/química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/administração & dosagem , Liberação Controlada de Fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Colesterol/química , Química Farmacêutica , Composição de Medicamentos
12.
Mol Carcinog ; 62(8): 1163-1175, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37144864

RESUMO

Numerous epidemiological studies suggest a link between Parkinson's disease (PD) and cancer. However, their relevant pathogenesis is not clear. In the present study, we investigated the potential role of exosome-delivered α-synuclein (α-syn) in the regulation between PD and liver cancer. We cultured hepatocellular carcinoma (HCC) cells with exosomes derived from conditioned medium of the PD cellular model, and injected exosomes enriched with α-syn into the striatum of a liver cancer rat model. We found that α-syn-contained exosomes from the rotenone-induced cellular model of PD suppressed the growth, migration, and invasion of HCC cells. Integrin αVß5 in exosomes from the rotenone-induced PD model was higher than that in the control, resulting in more α-syn-contained exosomes being taken up by HCC cells. Consistently, in vivo experiments with rat models also confirmed exosome-delivered α-syn inhibited liver cancer. These findings illustrate the important role of PD-associated protein α-syn inhibiting hepatoma by exosome delivery, suggesting a new mechanism underlying the link between these two diseases and therapeutics of liver cancer.


Assuntos
Carcinoma Hepatocelular , Exossomos , Neoplasias Hepáticas , Doença de Parkinson , Animais , Ratos , alfa-Sinucleína/genética , alfa-Sinucleína/metabolismo , Carcinoma Hepatocelular/patologia , Exossomos/metabolismo , Neoplasias Hepáticas/patologia , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Rotenona/farmacologia , Humanos
13.
Arch Biochem Biophys ; 744: 109698, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37487948

RESUMO

Numerous epidemiological studies suggest a link between Parkinson's disease (PD) and cancer, indicating that PD-associated proteins may mediate the development of cancer. Here, we investigated a potential role of PD-associated protein α-synuclein in regulating liver cancer progression in vivo and in vitro. We found the negative correlation of α-synuclein with metabotropic glutamate receptor 5 (mGluR5) and γ-synuclein by analyzing the data from The Cancer Genome Atlas database, liver cancer patients and hepatoma cells with overexpressed α-synuclein. Moreover, upregulated α-synuclein suppressed the growth, migration, and invasion. α-synuclein was found to associate with mGluR5 and γ-synuclein, and the truncated N-terminal of α-synuclein was essential for the interaction. Furthermore, overexpressed α-synuclein exerted the inhibitory effect on hepatoma cells through the degradation of mGluR5 and γ-synuclein via α-synuclein-dependent autophagy-lysosomal pathway (ALP). Consistently, in vivo experiments with rotenone-induced rat model of PD also confirmed that, upregulated α-synuclein in liver cancer tissues through targeting on mGluR5/α-synuclein/γ-synuclein complex inhibited tumorigenesis involving in ALP-dependent degradation of mGluR5 and γ-synuclein. These findings give an insight into an important role of PD-associated protein α-synuclein accompanied by the complex of mGluR5/α-synuclein/γ-synuclein in distant communications between PD and liver cancer, and provide a new strategy in therapeutics for the treatment of liver cancer.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Doença de Parkinson , Animais , Ratos , alfa-Sinucleína/metabolismo , Autofagia/fisiologia , Carcinogênese , Transformação Celular Neoplásica , gama-Sinucleína/genética , gama-Sinucleína/metabolismo , Doença de Parkinson/metabolismo , Receptor de Glutamato Metabotrópico 5/genética , Receptor de Glutamato Metabotrópico 5/metabolismo , Regulação para Cima , Humanos
14.
Chem Rec ; 23(2): e202200237, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36538728

RESUMO

Single-atom site catalysts (SACs) provide an ideal platform to identify the active centers, explore the catalytic mechanism, and establish the structure-property relationships, and thus have attracted increasing interests for electrocatalytic energy conversion. Substantial endeavors have been devoted to the construction of carbon-supported SACs, and their progress have been comprehensively reviewed. Compared with carbon-supported SACs, transition metal compounds (TMCs)-supported SACs are still in their infancy in the field of electrocatalysis. However, they have also aroused ever-increasing attention for driving electrocatalytic water splitting, and emerged as an indispensable class of SACs in recent years, predominately owing to their inherently structural features, such as rich anchoring sites, surface defects, and lattice vacancy. Herein, in this review, we have systematically summarized the recent advances of a variety of TMC supported SACs toward electrocatalytic water splitting. The advanced characterization techniques and theoretical analyses for identifying and monitoring the atomic structure of SACs are firstly manifested. Subsequently, the anchoring and stabilization mechanisms for TMC supported SACs are also highlighted. Thereafter, the advances of TMC supported SACs for driving water electrolysis are systematically unraveled.

15.
Analyst ; 148(5): 1058-1067, 2023 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-36728941

RESUMO

Cell-imprinted polymers (CIPs) for yeasts were fabricated via metal-free visible-light-induced atom transfer radical polymerization (MVL ATRP) on the surface of a glassy carbon electrode (GCE) which had been modified with gold nanoparticles (AuNPs)/MXene (Ti3C2Tx) composites. Here, the AuNPs/Ti3C2Tx composites form a macroporous structure, which could improve the electron transfer rate of the materials and facilitate the leaving or rebinding of cells. Methacrylic acid (MAA) and N,N'-methylene bis-acrylamide (MBA) were selected as the functional monomer and cross-linker of CIPs, because they could form efficient hydrogen bonding with mannan from yeast cell walls. The obtained electrode (CIPs/AuNPs/Ti3C2Tx/GCE) was characterized by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS). Further experiments indicated that the CIPs/AuNPs/Ti3C2Tx/GCE electrode could be utilized as an electrochemical biosensor to determine yeast cells by differential pulse voltammetry (DPV). The linear response range was 1.0 × 102 to 1.0 × 109 cells per mL and the detection limit was 20 cells per mL (S/N = 3). The CIPs/AuNPs/Ti3C2Tx/GCE electrode also showed good selectivity, repeatability, reproducibility, and regeneration. Finally, the proposed sensor was used to detect yeast cells in commercial samples of Saccharomyces boulardii sachets by a standard addition method. The obtained recovery was from 96.9 to 104.8% showing its potential applications in clinical and diagnostic research.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Ouro/química , Nanopartículas Metálicas/química , Polímeros/química , Reprodutibilidade dos Testes , Saccharomyces cerevisiae , Técnicas Eletroquímicas/métodos , Carbono/química , Eletrodos , Técnicas Biossensoriais/métodos , Limite de Detecção
16.
Inorg Chem ; 62(4): 1659-1666, 2023 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-36649641

RESUMO

Rational design of fast and sensitive determination of nitrite (NO2-) from a complicated actual sample overtakes a crucial role in constructing a high-efficiency sensing platform. Herein, a visual NO2- sensing platform with outstanding selectivity, sensitivity, and stability based on a surface plasmon resonance (SPR)-enhanced oxidase-like activity has been proposed. Benefiting from the intrinsic photocatalytic activity and limited light penetration of ZnS, the oxidase-like activity based on ZnS decorated on Ag nanowires (Ag@ZnS) is determined. It is demonstrated that the electrons are generated efficiently on the surface of ZnS and then transferred into the hot electrons of Ag with the help of localized SPR excitation, thus greatly oxidating the colorless 3,3',5,5'-tetramethylbenzidine (TMB) to produce dark blue oxidized TMB (oxTMB). When nitrite is added into the reaction system, the oxTMB will selectively react with NO2- to generate diazotized oxTMB, leading to a visual color change from dark blue to light green and subsequently to dark yellow. Owing to the specific recognition between nitrite and oxTMB, the recovery of catalytic activity induced an enhanced colorimetric test with a wider linear range for NO2- determination, an ultralow detection limit of 0.1 µM, excellent selectivity, and practicability for application in real samples. This plasmon-enhanced oxidase-like activity not only provides a smart approach to realize a colorimetric assay with high sensitivity and simplicity but also modulates oxidase-like activities.


Assuntos
Nanofios , Oxirredutases , Nitritos , Dióxido de Nitrogênio , Colorimetria , Limite de Detecção
17.
Anal Bioanal Chem ; 415(1): 157-166, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36348040

RESUMO

Sensitive determination of ofloxacin (OFL) is very essential for human health and environmental protection. Here, a novel composite of gold nanoparticles(nAu)@MXene(Ti3C2Tx)/poly-p-aminobenzene sulfonic acid (PABSA) was fabricated on the surface of glassy carbon electrode (GCE) and used to sensitively determine OFL. The results of experiments showed that the obtained nAu@Ti3C2Tx/PABSA/GCE electrode could be used as an electrochemical sensor to directly detect ofloxacin (OFL) by differential pulse voltammetry (DPV). Under the optimal conditions, the proposed electrode displayed a broader linear range and a lower detection limit (LOD) for OFL determination when it was compared to those similar sensors. The linear range was from 5.0 × 10-8 to 5.0 × 10-4 mol/L and the LOD was 3.7 × 10-8 mol/L (S/N = 3). The nAu@Ti3C2Tx/PABSA/GCE electrode also showed good selectivity, repeatability, and reproducibility. Finally, the proposed electrode was used to detect OFL in commercial samples by the standard addition method. The obtained recovery was from 97.3% and 105.7% showing its potential applications in actual sample analysis.


Assuntos
Ouro , Nanopartículas Metálicas , Humanos , Reprodutibilidade dos Testes , Eletrodos , Técnicas Eletroquímicas/métodos , Carbono
18.
Ecotoxicol Environ Saf ; 262: 115141, 2023 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-37320917

RESUMO

Cytosine arabinoside (Ara-C) is one of the most widely used chemotherapeutic agents for hematological malignancies. The residues of Ara-C have been detected in wastewater and river water with increased usage and discharge. As the ability to cross the placenta and the teratogenicity at low ng/L levels, the toxic effects on pregnant women and infants have been concerned. The toxicity of Ara-C exposure on early embryonic neurodevelopment has not been fully elucidated. In this study, pregnant C57BL/6 mice were injected with different doses of Ara-C on Gestation day (GD) 7.5 and assessed on GD11.5 and GD13.5 to explore the neural developmental effects of Ara-C. HE staining, immunofluorescence, western blot, EdU assay, and flow cytometry were utilized to determine the toxic effects of Ara-C in vivo and in vitro. Our results showed that Ara-C (15-22.5 mg/kg body weight) induced the occurrence of neural tube defects (NTDs). The expression of PH3 was markedly reduced in embryos with Ara-C-induced NTDs, compared to the control group (P < 0.05). In contrast, cell apoptosis was markedly increased. Increased expression levels of GFAP and decreased Nestin were observed in the embryonic brain tissues in Ara-C induced NTDs. The level of ß-catenin was also decreased on both GD11.5 and GD13.5. These results were confirmed in vitro using mouse Sv129 embryonic stem cells (mESC). Ara-C at a dose comparable to the environment level (0.05 nM) had cytotoxicity. Impaired Wnt/ß-catenin signaling pathway is involved in Ara-C exposure induced imbalance between cell proliferation, apoptosis, and differentiation, which might contribute to Ara-C-induced occurrence of NTDs. Our data indicated the environmental concentration of Ara-C had cytotoxicity and that maternal exposure to Ara-C induced NTDs. These results might provide more information to understand the environmental toxic impact of Ara-C on neurodevelopment.

19.
Int J Neurosci ; : 1-6, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37459646

RESUMO

BACKGROUND AND OBJECTIVES: Neuromyelitis optica spectrum disorder (NMOSD) is a group of demyelinating diseases of the nervous system with high relapse rate and high disability rate without treatment, and we aimed to explore the influencing factors related to the recurrence of NMOSD and provide basis for clinical treatment in this study. METHODS: Referring to the diagnostic criteria for NMOSD issued in 2015, 259 patients were enrolled. Clinical information, cerebrospinal fluid (CSF) and serum analysis results, brain and spinal cord magnetic resonance imaging (MRI) findings, treatment details, and prognosis were all recorded. RESULTS: 176 (68.00%) participants were found to be AQP4 Ab-positive in serum or CSF, and the relapse rate was 36.67% (95/259). These 259 individuals were separated into two groups: non-release (n = 164) and relapse (n = 95). In terms of EDSS scores at onset, EDSS score after treatment, lesion location, serum creatinine (Cr) and treatment strategy, there were statistical differences between the two groups. Multivariable logistic regression analyses revealed five predictors for recurrence of NMOSD patients within two years: EDSS scores at onset, transverse myelitis, brain/brainstem, Cr, and Rituximab/immunosuppressants. CONCLUSION: It is essential to explore the risk factors related to recurrence and prevent them to reduce the risk of disability and improve the prognosis, and the recurrence rate of NMOSD may be affected by several factors.

20.
J Am Chem Soc ; 144(12): 5295-5303, 2022 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-35294182

RESUMO

The discovery of the intrinsic magnetic order in single-layer chromium trihalides (CrX3, X = I, Br, and Cl) has drawn intensive interest due to their potential application in spintronic devices. However, the notorious environmental instability of this class of materials under ambient conditions renders their device fabrication and practical application extremely challenging. Here, we performed a systematic investigation of the degradation chemistry of chromium iodide (CrI3), the most studied among CrX3 families, via a joint spectroscopic and microscopic analysis of the structural and composition evolution of bulk and exfoliated nanoflakes in different environments. Unlike other air-sensitive 2D materials, CrI3 undergoes a pseudo-first-order hydrolysis in the presence of pure water toward the formation of amorphous Cr(OH)3 and hydrogen iodide (HI) with a rate constant of kI = 0.63 day-1 without light. In contrast, a faster pseudo-first-order surface oxidation of CrI3 occurs in a pure O2 environment, generating CrO3 and I2 with a large rate constant of kCr = 4.2 day-1. Both hydrolysis and surface oxidation of CrI3 can be accelerated via light irradiation, resulting in its ultrafast degradation in air. The new chemical insights obtained allow for the design of an effective stabilization strategy for CrI3 with preserved optical and magnetic properties. The use of organic acid solvents (e.g., formic acid) as reversible capping agents ensures that CrI3 nanoflakes remain stable beyond 1 month due to the effective suppression of both hydrolysis and oxidation of CrI3.

SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa