Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Adv Sci (Weinh) ; 11(22): e2309963, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38544340

RESUMO

The electroreduction of carbon dioxide (CO2) to multi-carbon (C2+) compounds offers a viable approach for the up-conversion of greenhouse gases into valuable fuels and feedstocks. Nevertheless, current industrial applications face limitations due to unsatisfactory conversion efficiency and high overpotential. Herein, a facile and scalable plasma fluorination method is reported. Concurrently, self-evolution during CO2 electroreduction is employed to control the active sites of Cu catalysts. The copper catalyst modified with fluorine exhibits an impressive C2+ Faradaic efficiency (FE) of 81.8% at a low potential of -0.56 V (vs a reversible hydrogen electrode) in an alkaline flow cell. The presence of modified fluorine leads to the exposure and stabilization of high-activity Cu+ species, enhancing the adsorption of *CO intermediates and the generation of *CHO, facilitating the subsequent dimerization. This results in a notably improved conversion efficiency of 13.1% and a significant reduction in the overpotential (≈100 mV) for the C2+ products. Furthermore, a superior C2+ FE of 81.6% at 250 mA cm-2, coupled with an energy efficiency of 31.0%, can be achieved in a two-electrode membrane electrode assembly electrolyzer utilizing the fluorine-modified copper catalyst. The strategy provides novel insights into the controllable electronic modification and surface reconstruction of electrocatalysts with practical potential.

2.
PLoS One ; 19(3): e0296980, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38547255

RESUMO

In the era of rapid product iteration, companies need simple and effective methods to guide the entire process of product innovation design and enhance their product innovation capabilities. Most research focused on improving one or several steps in the product design process. Although some scholars have proposed methods that guided the entire process, they combined more than three different theories, which increased the difficulty of theoretical learning and the complexity of practical implementation. This paper proposed a product innovation design process composed of three theoretical methods: Kano, Axiomatic Design (AD), and Theory of the Solution of Inventive Problems (TRIZ). This new process guided the entire product design process with fewer theoretical methods, reducing the difficulty of learning and implementation. The paper demonstrated the effectiveness of this method through the design practice of a portable two-wheeled self-balancing vehicle. Additionally, the discussion section explored the method's potential from the design management perspective.


Assuntos
Invenções , Aprendizagem , Nigéria
3.
Front Psychol ; 14: 1243623, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38046118

RESUMO

Introduction: This study examined the interplay between parenting styles, empathy, and aggressive behavior in Chinese preschool children aged 3-5 years. Methods: Data were collected from 87 participants using the Child Behavior Checklist, Children's Empathy Quotient, and Parenting Style Questionnaire, and were subsequently analyzed. Results: The findings revealed significant age and gender differences in empathy, but not in parenting styles or aggressive behavior. Additionally, a substantial correlation was identified between authoritarian parenting style and aggressive behavior, as well as between children's empathy levels and aggressive behavior. This indicates that empathy may act as a mediator between parenting style and aggressive behavior. Discussion: Our findings suggest that an authoritarian parenting style influences aggressive behavior both directly and indirectly through its effect on children's empathy. These results point toward the possibility that an authoritarian parenting style may stifle the development of empathy in preschool children, subsequently heightening their aggressive behavior.

4.
Environ Pollut ; 323: 121337, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36841420

RESUMO

Atrazine is a biotoxic long-residing herbicide whose toxic effects on soil microorganisms have attracted widespread attention. However, previous studies on the effects of atrazine on soil microorganisms have yielded highly variable results. Therefore, a meta-analysis using a database containing 1141 data points from 39 peer-reviewed papers was conducted to illustrate the response of soil microorganisms to the application of atrazine. The results showed that the application of atrazine significantly increased soil microbial biomass and respiration by 8.9% and 26.77%, respectively, and decreased soil microbial diversity and enzyme activity by 4.87% and 24.04%, respectively. In addition, mixed-effect models were used to explain the influence of moderator variables, including water holding capacity, temperature, pH, organic carbon content, atrazine concentration, duration, and soil texture, on the results to help account for inconsistent conclusions. It was found that soil microbial biomass was significantly positively correlated with temperature, organic carbon content, atrazine concentration, clay content and silt content, while it was negatively correlated with pH and sand content. Soil microbial respiration was negatively correlated with pH and positively correlated with atrazine concentration. Soil microbial diversity was positively correlated with water holding capacity, pH, silt content and sand content, and negatively correlated with organic carbon content and clay content. Soil enzyme activity, the indicator that showed the largest decrease after atrazine application, was significantly positively correlated with water holding capacity, temperature, organic carbon content, and herbicide concentration; it was negatively correlated with soil pH. On the basis of these analysis results, we recommend that atrazine should not be allowed to persist in alkaline sandy soil for long periods of time, as this can result in atrazine having a significant negative impact on soil microorganisms.


Assuntos
Atrazina , Herbicidas , Poluentes do Solo , Atrazina/análise , Solo/química , Areia , Argila , Microbiologia do Solo , Herbicidas/análise , Carbono , Água/análise , Poluentes do Solo/toxicidade , Poluentes do Solo/análise
5.
Am J Orthod Dentofacial Orthop ; 162(2): 162-172, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35654687

RESUMO

INTRODUCTION: The zygomaticomaxillary suture (ZMS) maturation evaluation is a reliable method for predicting the optimal timing of maxillary protraction. The objective of this study was to compare age distribution patterns of ZMS maturation stages between cleft lip and palate (CLP) patients and non-cleft lip and palate (non-CLP) patients to aid our comprehension in choosing the optimal timing of maxillary protraction. METHODS: Samples of 216 non-CLP and 220 CLP Asian patients without orthodontic and orthognathic treatment aged 5-25 years were scanned to evaluate the ZMS maturation stage by 2 evaluators blindly. Evaluators' agreements and bilateral ZMS maturation consistency were assessed by weighted kappa tests. Age distribution patterns of each ZMS maturation stage were described. Gender effect and age distribution differences between groups were analyzed using an independent t-test. RESULTS: Evaluators' agreements and bilateral ZMS maturation consistency were satisfying (weighted kappa coefficient >0.90). At stages A and B, patients with CLP were 1.3 and 0.4 years older than patients in the non-CLP group (P <0.001 and P = 0.01). In contrast, at stage C, patients with CLP were approximately 1.2 years younger (P = 0.004). Gender barely played a role in the divergence of ZMS maturation (P >0.05). No statistically significant difference was observed between ZMS maturation of patients with unilateral or bilateral cleft lip and palate (UBCLP) and patients with unilateral or bilateral cleft lip (UBCL) (P >0.05). CONCLUSIONS: The ZMS development of patients with CLP was premature at stage C, whereas delayed at stages A and B.


Assuntos
Fenda Labial , Fissura Palatina , Fenda Labial/cirurgia , Fissura Palatina/cirurgia , Suturas Cranianas , Humanos , Suturas
6.
Artigo em Inglês | MEDLINE | ID: mdl-35668782

RESUMO

Objective: Biheimaer (BHM) is a hospital formulation for clinical treatment of dyspepsia and acid reflux, based on Compatibility Theory of Traditional Chinese Medicine. This study anticipated to elucidate the molecular mechanism of BHM against Functional dyspepsia via combined network pharmacology prediction with experimental verification. Methods: Based on network pharmacology, the potential active components and targets of BHM in the treatment of functional dyspepsia were explored by prediction and molecular docking technology. The results of protein-protein interaction analysis, functional annotation, and pathway enrichment analysis further refined the main targets and pathways. The molecular mechanism of BHM improving functional dyspepsia mice induced by L-arginine + atropine was verified on the basis of network pharmacology. Results: In this study, 183 effective compounds were screened from BHM; moreover, 1007 compound-related predicted targets and 156 functional dyspepsia-related targets were found. The results of enrichment analysis and in vivo experiments showed that BHM could regulate intestinal smooth muscle contraction to play a therapeutic role in functional dyspepsia by reducing the expression of NOS3, SERT, TRPV1, and inhibiting the inflammatory cytokine (IL-1ß, TNF-α) to intervene the inflammatory response in mice. Conclusions: This study revealed the molecular biological mechanisms of the Traditional Chinese Medicine formulation of BHM in functional dyspepsia by network pharmacology and experimental verification, meanwhile provided scientific support for subsequent clinical medication.

7.
Nano Lett ; 22(13): 5451-5458, 2022 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-35731860

RESUMO

Laser-induced graphene (LIG) suffers from serious decay in long-term biosensing, which greatly restricts its practical applications. Herein, we report a new strategy to engineer the LIG surface with Au clusters and chitosan sequentially to form a C-Au-LIG electrode with a superhydrophilic and highly conductive 3D graphene surface, which demonstrates superior performance and negligible decay in both long-term storage and practical usage in vitro and in vivo environments. Moreover, the C-Au-LIG electrode can be used for detecting uric acid (UA) and pH simultaneously from a single differential pulse voltammetry curve with low-detection limitation, high accuracy, and negligible interference with other sweat biomarkers. The integrated C-Au-LIG wearable biosensor was employed to continuously monitor the UA content in human sweat, which can well reflect the daily intake of purines for at least 10 days. Therefore, the C-Au-LIG electrode demonstrates significant application potential and provides inspiration for surface engineering of other biosensor materials and electrodes.


Assuntos
Técnicas Biossensoriais , Grafite , Técnicas Eletroquímicas , Eletrodos , Grafite/química , Humanos , Concentração de Íons de Hidrogênio , Lasers , Ácido Úrico
8.
Toxicol Appl Pharmacol ; 439: 115939, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35217026

RESUMO

Drosophila is often exposed to harmful environments, and the intestinal epithelium is the first line of defense against external infection. Intestinal stem cells (ISCs) in the Drosophila midgut play a crucial role in maintaining tissue homeostasis and compensating for cell loss caused by tissue damage. Crocus sativus L. (saffron) can protect against intestinal injury in response to inflammation; however, the specific protective components of saffron and the related mechanisms remain unclear. Safranal is one of the main components of saffron. Here, we used dextran sodium sulfate (DSS) or Erwinia carotovora carotovora 15 (Ecc15) to create an intestinal injury model and explored the protective effect of safranal against tissue damage. Excessive proliferation and differentiation of ISCs in the Drosophila midgut were observed after DSS or Ecc15 feeding; however, these phenotypes were rescued after safranal feeding. In addition, we found that this process occurred through inhibition of the c-Jun N-terminal kinase (JNK), epidermal growth factor receptor (EGFR) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathways. Furthermore, safranal inhibited the Ecc15- and DSS-induced increases in antimicrobial peptide (AMP) and reactive oxygen species (ROS) levels and intestinal epithelial cell death, thereby protecting gut integrity. In summary, safranal was found to have a significant protective effect and maintain intestinal homeostasis in Drosophila; these findings provide a foundation for the application of safranal in clinical research and the treatment of intestinal injury.


Assuntos
Cicloexenos , Drosophila , Animais , Cicloexenos/farmacologia , Drosophila/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Terpenos/farmacologia
9.
Shanghai Kou Qiang Yi Xue ; 31(6): 661-667, 2022 Dec.
Artigo em Chinês | MEDLINE | ID: mdl-36970806

RESUMO

PURPOSE: To investigate the impact of maxillary sinus floor on the mesial movement of maxillary first molar. METHODS: Orthodontic patients with maxillary first premolars extracted were selected. Their maxillary first molars were divided into case group and control group according to whether their roots were in contact with the maxillary sinus floor. The case group was further divided into three subtypes according to the depth of the root extruded into the maxillary sinus. A total of 64 maxillary first molars from 32 patients were enrolled in this study, including 34 in the case group (five in subtype Ⅱ, fourteen in subtype Ⅲ, and 15 in subtype Ⅳ) and 30 in the control group. The mesial movement distance of each root and crown and the inclination of each root long axis were measured, and resorption of each root was evaluated. SPSS 22.0 software package was used for data analysis. RESULTS: After orthodontic treatment, the mesial movement distance of roots from both groups were all lager than 2 mm. The mesial movement distance of the crown was not statistically different between the two groups (P>0.05), while the mesial movement distance of the roots in the control group was significantly larger than in the case group(P<0.05). Inclined movement towards the mesial direction was found in both groups, and the inclination angle was significantly larger in the case group(P<0.05). The inclination angle of the first molars in the subtype Ⅳ was significantly larger than that in the subtype Ⅲ and the control group. Most of the maxillary first molars from both groups had no obvious root resorption(P>0.05). CONCLUSIONS: With the proper force system, maxillary first molars with roots extruded into the maxillary sinus floor can be moved mesialy with mild or no root resorption, while a larger inclination can be found compared with maxillary first molars without root extruding into the maxillary sinus floor. The deeper the root extruding into the maxillary sinus, the larger the inclination angle will be.


Assuntos
Reabsorção da Raiz , Levantamento do Assoalho do Seio Maxilar , Humanos , Seio Maxilar/diagnóstico por imagem , Dente Molar , Dente Pré-Molar , Maxila , Raiz Dentária
10.
J Diabetes Investig ; 12(8): 1326-1335, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33300305

RESUMO

AIMS/INTRODUCTION: Periodontal disease, a chronic inflammation induced by bacteria, is closely linked with diabetes mellitus. Many complications associated with diabetes are related to epigenetic changes. However, the exact epigenetic changes whereby diabetes affects periodontal disease remain largely unknown. Thus, we sought to investigate the role of diabetes-dependent epigenetic changes of gingival tissue in the susceptibility to periodontal disease. MATERIALS AND METHODS: We studied the effect of streptozotocin-induced diabetes in minipigs on gingival morphological and epigenetic tissue changes. Accordingly, we randomly divided six minipigs into two groups: streptozotocin-induced diabetes group, n = 3; and non-diabetes healthy control group, n = 3. After 85 days, all animals were killed, and gingival tissue was collected for histology, deoxyribonucleic acid methylation analysis and immunohistochemistry. RESULTS: A diabetes mellitus model was successfully created, as evidenced by significantly increased blood glucose levels, reduction of pancreatic insulin-producing ß-cells and histopathological changes in the kidneys. The gingival tissues in the diabetes group presented acanthosis of both gingival squamous epithelium and sulcular/junctional epithelium, and a significant reduction in the number and length of rete pegs. Deoxyribonucleic acid methylation analysis showed a total of 1,163 affected genes, of which 599 and 564 were significantly hypermethylated and hypomethylated, respectively. Immunohistochemistry staining showed that the hypomethylated genes - tumor necrosis factor-α and interleukin-6 - were positively expressed under the junctional epithelium area in the diabetes group. CONCLUSIONS: Diabetes mellitus induces morphological and epigenetic changes in periodontal tissue, which might contribute to the increased susceptibility of periodontal diseases in patients with diabetes.


Assuntos
Complicações do Diabetes/genética , Diabetes Mellitus Experimental/genética , Epigênese Genética , Periodontite/etiologia , Periodontite/genética , Animais , Glicemia/análise , Metilação de DNA , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/complicações , Gengiva/patologia , Imuno-Histoquímica , Interleucina-6/metabolismo , Masculino , Periodontite/patologia , Suínos , Porco Miniatura , Fator de Necrose Tumoral alfa/metabolismo
11.
Oncol Rep ; 44(4): 1596-1604, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32945475

RESUMO

The aim of the present study was to explore the antitumor effects of sinoporphyrin sodium (DVDMS)­mediated photodynamic therapy (PDT) and sonodynamic therapy (SDT) in glioma, and to reveal the underlying mechanisms. The uptake of DVDMS by U­118 MG cells was detected by flow cytometry (FCM). A 630­nm semiconductor laser and 1­MHz ultrasound were used to perform PDT and SDT, respectively. Cell proliferation and apoptosis were evaluated using the Cell Counting Kit­8 assay, FCM and Hoechst 33258 staining, respectively. Western blot analysis was used to detect protein expression and phosphorylation levels. BALB/c nude mice were used to establish a xenograft model of U­118 MG cells. DVDMS was injected intravenously and PDT and SDT were performed 24 h later. An in vivo imaging system was used to evaluate the fluorescence of DVDMS, to measure tumor sizes, and to evaluate the therapeutic effects. The uptake of DVDMS by U­118 MG cells was optimal after 4 h. PDT and SDT following DVDMS injection significantly inhibited the proliferation and increased apoptosis of glioma cells in vitro (P<0.05, P<0.01) respectively. In vivo, the fluorescence intensity of DVDMS was lower in the PDT and SDT groups compared with the DVDMS group, while tumor cell proliferation and weight were lower in the PDT and SDT groups than in the control group (P<0.05, P<0.01). However, there was no significant difference when laser, ultrasound or DVDMS were applied individually, compared with the control group. Hematoxylin and eosin staining suggested that both PDT and SDT induced significant apoptosis and vascular obstruction in cancer tissues. DVDMS­mediated PDT and SDT inhibited the expression levels of proliferating cell nuclear antigen (PCNA) and Bcl­xL, increased cleaved ­caspase 3 levels, and decreased the protein phosphorylation of the PI3K/AKT/mTOR signaling pathway. Changes in the expression of PCNA, and Bcl­xL and in the levels of cleaved­caspase 3 were partly reversed by N­acetyl­L­cysteine, a reactive oxygen species (ROS) scavenger. Similar results were obtained with FCM. DVDMS­mediated PDT and SDT inhibited glioma cell proliferation and induced cell apoptosis in vitro and in vivo, potentially by increasing the generation of ROS and affecting protein expression and phosphorylation levels.


Assuntos
Glioma/terapia , Fotoquimioterapia , Porfirinas/farmacologia , Terapia por Ultrassom , Animais , Apoptose/efeitos dos fármacos , Apoptose/efeitos da radiação , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/efeitos da radiação , Terapia Combinada , Citometria de Fluxo , Glioma/patologia , Humanos , Lasers Semicondutores/uso terapêutico , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto
12.
ACS Appl Mater Interfaces ; 12(30): 33785-33794, 2020 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-32631054

RESUMO

Fabrication of superior nonprecious electrocatalysts is essential for water electrolysis. Herein, the epitaxial growth of the XMoO4 (X = Ni, Co, Fe) nanosheets on the hexagonal MoO2 nanoplates are carried out. The preoxidation of MoO2 nanoplate is fatal to the epitaxial growth of a nanosheets array on MoO2 nanoplates. The hierarchical heterostructure of the vertically aligned NiMo nanosheets on MoO2 nanoplate (NiMo/MoO2) is well-maintained in the process of in situ topotactic reduction transformation from NiMoO4·xH2O/MoO2. Attributing it to the rich electroactive sites from nanosheets array, together with the intrinsic electrocatalytic performance of NiMo alloy, the as-engineered NiMo/MoO2 as electrocatalyst exhibits admirable hydrogen evolution reaction (HER) activity with a small onset potential of -12 mV vs RHE (1 mA cm-2) and a tafel value of 43.6 mV dec-1 at alkaline media. Furthermore, the obtained CoMoO4/MoO2 possesses excellent oxygen evolution performance, which is verified by an ultralow overpotential of 230 mV@10 mA cm-2, small Tafel slope (51 mV dec-1), and robust durability. The developed NiMo/MoO2 and CoMoO4/MoO2 electrocatalysts are assembled into an alkaline electrolyzer, which affords a cell potential of 1.51 V at 10 mA cm-2, as well as outstanding operational durability, which is superior to the typically constructed 20 wt % Pt/C-RuO2 system (1.59 V at 10 mA cm-2). Hence, the universal strategy using MoO2 nanoplates as Mo source and epitaxial substrate may be extended to explore and construct economical and superior Mo-based electrocatalysts for water electrolysis.

13.
Clin Cancer Res ; 26(12): 2810-2818, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32156743

RESUMO

PURPOSE: Bruton tyrosine kinase (BTK) inhibition alone leads to incomplete responses in chronic lymphocytic leukemia (CLL). Combination therapy may reduce activation of escape pathways and deepen responses. This open-label, phase Ib, sequential dose-escalation and dose-expansion study evaluated the safety, tolerability, pharmacokinetics, and preliminary efficacy of the selective BTK inhibitor tirabrutinib alone, in combination with the PI3K delta (PI3Kδ) inhibitor idelalisib, or with the spleen tyrosine kinase (SYK) inhibitor entospletinib in patients with relapsed/refractory CLL. PATIENTS AND METHODS: Patients received either tirabrutinib monotherapy (80 mg every day) or tirabrutinib 20-150 mg every day in combination with either idelalisib (50 mg twice a day or 100 mg every day) or entospletinib (200 mg or 400 mg every day). RESULTS: Fifty-three patients were included. Systemic tirabrutinib exposure was comparable between monotherapy and combination therapy. No MTD was identified. Across all treatment groups, the most common adverse event was diarrhea (43%, 1 patient grade ≥3); discontinuation due to adverse events was uncommon (13%). Objective response rates were 83%, 93%, and 100%, and complete responses were 7%, 7%, and 10% in patients receiving tirabrutinib, tirabrutinib/idelalisib, and tirabrutinib/entospletinib, respectively. As of February 21, 2019, 46 of 53 patients continue to receive treatment on study. CONCLUSIONS: Tirabrutinib in combination with idelalisib or entospletinib was well tolerated in patients with CLL, establishing an acceptable safety profile for concurrent selective inhibition of BTK with either PI3Kδ or SYK. This small study did not establish a superior efficacy of the combinations over tirabrutinib alone. This trial is registered at www.clinicaltrials.gov (NCT02457598).


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Terapia de Salvação , Idoso , Idoso de 80 Anos ou mais , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Feminino , Seguimentos , Humanos , Imidazóis/administração & dosagem , Indazóis/administração & dosagem , Leucemia Linfocítica Crônica de Células B/patologia , Masculino , Dose Máxima Tolerável , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Prognóstico , Purinas/administração & dosagem , Pirazinas/administração & dosagem , Pirimidinas/administração & dosagem , Quinazolinonas/administração & dosagem , Distribuição Tecidual
14.
ACS Appl Mater Interfaces ; 12(2): 2362-2369, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31846290

RESUMO

As a green, pollution-free, and renewable clean energy source, photocatalytic H2 production has attracted great attention. Here, epitaxial growth of pyramidal CdS-Cd nanoparticles on S-doped MoO2 nanosheets (CdS-Cd/S-MoO2) was prepared by one-step co-sublimation of CdS and MoO3. The photogenerated electrons of CdS as a photocatalyst are transferred to Cd and S-MoO2 as co-catalysts for H2 production, which is observed by surface photovoltage (SPV) under visible light irradiation. At last, the obtained CdS-Cd/S-MoO2 presented an efficient photocatalytic performance under the visible light (>420 nm) with a prominent H2 generation rate of as high as 24.98 µmol h-1 mg-1, which is 11 times higher than that of the CdS-Cd nanoparticles (2.26 µmol h-1 mg-1), and it is superior than that of the CdS (1.51 µmol h-1 mg-1).

15.
iScience ; 19: 1090-1100, 2019 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-31527009

RESUMO

The large-scale application of economically efficient electrocatalysts for hydrogen evolution reaction (HER) is limited in view of the high cost of polymer binders (Nafion) for immobilizing of powder catalysts. In this work, nitrogen-doped molybdenum carbide nanobelts (N-Mo2C NBs) with porous structure are synthesized through a direct pyrolysis process using the pre-prepared molybdenum oxide nanobelts (MoO3 NBs). Nanocellulose instead of Nafion-bonded N-Mo2C NBs (N-Mo2C@NCs) exhibits superior performance toward HER, because of excellent dispersibility and multiple exposed catalytically active sites. Furthermore, the conductive film composed of N-Mo2C NBs, graphene nanosheets, and nanocellulose (N-Mo2C/G@NCs) is fabricated by simple vacuum filtration, as flexible and editable electrode, which possesses excellent performance for scale HER applications. This work not only proposes the potential of nanocellulose to replace Nafion for binding powder catalysts, but also offers a facile strategy to prepare flexible and conductive films for a wide variety of nanomaterials.

16.
Int J Mol Med ; 43(4): 1635-1642, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30816515

RESUMO

The present study describes the preparation of a dodecapeptide YHWYGYTPQNVI (GE11)­conjugated liposome bound with polyethylene glycol to enhance the therapeutic effect of resveratrol (RSV) in head and neck cancer cells. The results indicated that (RSV)­loaded GE11­conjugated liposomes (RSV­GL) exhibited a high entrapment efficiency of >95%, with an active drug loading level of 19.5% w/w. Release kinetics revealed that RSV was released in a slow and sustained manner from the RSV­GL and RSV­loaded liposome (RSV­L) nanoparticulate systems. The epidermal growth factor receptor (EGFR)­overexpressing squamous cell carcinoma HN cells specifically internalized GE11 surface­conjugated liposome in a manner that was markedly increased compared with that of the non­targeted carrier. Consistently, RSV­GL exhibited a significantly increased cytotoxic effect compared with that of the non­targeted nanoparticles. Notably, RSV­GL induced significantly increased proportions of early (~60%) and late (~10%) apoptotic cells in head and neck cancer cell populations. To the best of our knowledge, the application and development of EGFR­targeted peptide­conjugated liposome system for RSV delivery has not been studied previously in the treatment of head and neck cancer. In addition, RSV­GL exhibited the greatest antitumor efficacy compared with any other group. RSV­GL exhibited a 2­fold decrease in tumor volume compared with the free RSV and a 3­fold decrease in volume compared with the control. Overall, the nanomedicine strategy described in the present study may potentially advance the chemotherapy­based treatment of head and neck cancer, with promising applications in other EGFR­overexpressing tumors.


Assuntos
Peptídeos/farmacologia , Resveratrol/farmacologia , Carcinoma de Células Escamosas de Cabeça e Pescoço/patologia , Sequência de Aminoácidos , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Liberação Controlada de Fármacos , Feminino , Humanos , Lipossomos , Camundongos Nus , Tamanho da Partícula , Peptídeos/química
17.
RSC Adv ; 9(19): 10528-10535, 2019 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-35515276

RESUMO

Here, we show that berberine (BBR) nanoparticles (BBRNPs, ∼300 nm hydrodynamic diameter) are a promising sonosensitizer for cancer sonodynamic therapy (SDT). HeLa cells were cultured for in vitro investigation, and a HeLa xenograft tumor model was established with BALB/c nude mice (∼20 g, female) for in vivo study. Significant effects of BBRNP-mediated SDT were observed in both in vitro and in vivo experiments. Cell counting kit-8 (CCK-8) cell proliferation and cytotoxicity assays were performed to confirm if BBRNPs-SDT has cytotoxicity against HeLa cells in vitro. The mechanism for inhibition of tumor proliferation by BBRNPs-SDT was investigated via flow cytometry, photoluminescence spectroscopy, dynamic light scattering, scanning electron microscopy, ultrasonic contrast imaging, tumour pathological analysis, western blot and anatomical analysis. We identified two ongoing assumptive mechanisms. One is due to the tumor angioembolism effect, which blocks oxygen and nutrient supply in situ, leading to early-stage HeLa apoptosis. The other domino effect is due to ultrasonic energy-activated BBRNP cavitation and reactive oxygen species release, which leads to tumor vascular injury and finally induces HeLa apoptosis, resulting in tumour shrinkage. Both pathways synergistically helped with HeLa xenograft tumor supression. In conclusion, we posit that BBRNPs are a promising agent for tumor SDT.

18.
ACS Appl Mater Interfaces ; 9(38): 32840-32850, 2017 Sep 27.
Artigo em Inglês | MEDLINE | ID: mdl-28872833

RESUMO

A new porous covalent porphyrin framework (CPF) filled with triphenylphosphine was designed and synthesized using the rigid tetrakis(p-bromophenyl)porphyrin (TBPP) and 1,3,5-benzenetriboronic acid trivalent alcohol ester as building blocks. The carbonization of this special CPF has afforded coupled Fe2P and Fe4N nanoparticles embedded in N-doped carbons (Fe2P/Fe4N@N-doped carbons). This CPF serves as an "all in one" precursor of Fe, N, P, and C. The porous property and solid skeleton of the CPF endow Fe2P/Fe4N@N-doped carbons with porous structure and a high degree of graphitization. As a result, Fe2P/Fe4N@N-doped carbons exhibited highly efficient multifunctional electrocatalytic performance for water splitting and oxygen electroreduction. Typically, Fe2P/Fe4N@C-800, obtained at a heat-treatment temperature of 800 °C, showed an ORR half-wave potential of 0.80 V in alkaline media and 0.68 V in acidic media, close to that of commercial Pt/C catalysts. Fe2P/Fe4N@C-800 also displayed efficient OER and HER activities, comparable to other phosphide and nitride electrocatalysts. The coupled Fe4N and Fe2P nanoparticles embedded in carbons exert unique catalytic efficiency for water splitting and fuel cells.

19.
PLoS One ; 9(5): e95316, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24835251

RESUMO

For many organisms, the reconstruction of source-sink dynamics is hampered by limited knowledge of the spatial assemblage of either the source or sink components or lack of information on the strength of the linkage for any source-sink pair. In the case of marine species with a pelagic dispersal phase, these problems may be mitigated through the use of particle drift simulations based on an ocean circulation model. However, when simulated particle trajectories do not intersect sampling sites, the corroboration of model drift simulations with field data is hampered. Here, we apply a new statistical approach for reconstructing source-sink dynamics that overcomes the aforementioned problems. Our research is motivated by the need for understanding observed changes in jellyfish distributions in the eastern Bering Sea since 1990. By contrasting the source-sink dynamics reconstructed with data from the pre-1990 period with that from the post-1990 period, it appears that changes in jellyfish distribution resulted from the combined effects of higher jellyfish productivity and longer dispersal of jellyfish resulting from a shift in the ocean circulation starting in 1991. A sensitivity analysis suggests that the source-sink reconstruction is robust to typical systematic and random errors in the ocean circulation model driving the particle drift simulations. The jellyfish analysis illustrates that new insights can be gained by studying structural changes in source-sink dynamics. The proposed approach is applicable for the spatial source-sink reconstruction of other species and even abiotic processes, such as sediment transport.


Assuntos
Distribuição Animal/fisiologia , Ecossistema , Modelos Teóricos , Cifozoários/fisiologia , Movimentos da Água , Alaska , Animais , Biomassa , Oceanos e Mares , Dinâmica Populacional , Análise de Regressão , Fatores de Tempo
20.
Virology ; 361(1): 204-11, 2007 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-17174373

RESUMO

The ORF38 of Autographa californica multiple nucleopolyhedrovirus (AcMNPV), or AcORF38, contains a conserved motif of Nudix (nucleotide diphosphate X) superfamily. It has the highest homology with ADP-ribose pyrophosphatase (ADPRase), a subfamily of Nudix pyrophosphatase. In the current study, recombinant AcORF38 protein was prepared and shown to have ADPRase activity, with a Km of 204 microM, and K(cat) of 6.96 s(-1) at pH 8.0 and 5 mM MgCl2. The transcription of AcORF38 was detected 2 h postinfection, and lasted until the late stage. An orf38 gene-deleted mutant virus, vAcGFP-Delta38, was constructed. Although it produced progeny virus, the yield of extracellular virus was less than 1% of the wild-type virus. The activity of viral very late gene promoter was also greatly reduced in vAcGFP-Delta38-infected cells as indicated by the expression of green fluorescence protein gene driven by polyhedrin promoter. The mutant phenotype was rescued by co-transfection with an AcORF38-expressing plasmid. These results suggest that AcORF38 plays an important role in virus replication, although the detail is to be elucidated.


Assuntos
Nucleopoliedrovírus/fisiologia , Pirofosfatases/metabolismo , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Genes Virais , Dados de Sequência Molecular , Nucleopoliedrovírus/química , Filogenia , Pirofosfatases/genética , Alinhamento de Sequência , Spodoptera , Proteínas Virais/genética , Replicação Viral
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA