Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 98
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Macromol Rapid Commun ; 44(2): e2200541, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36057795

RESUMO

It is shown that the aligned electrospun fibers are a convenient platform for studying the mechanical effects on nanomaterials, particularly when using surface-enhanced Raman scattering as a sensitive tool of monitoring. The ligands on the surface of the embedded Au nanoparticles fall off easily with the shear force from the stretching, in contrast to the counterparts protected by polymer/silica shells. Upon stretching, the chains of Au nanoparticles will reversibly break, as revealed by the dramatic changes in the longitudinal plasmon absorption. It is believed that such a platform will open a window for understanding mechanical effects at the nanoscale, and also a new means for synthetic control.


Assuntos
Nanopartículas Metálicas , Nanoestruturas , Análise Espectral Raman , Polímeros , Ouro
2.
J Invertebr Pathol ; 201: 108023, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37995901

RESUMO

The effects of chemical factors on the infectivity of DIV1 have not been fully accessed yet. In order to investigate the stability of DIV1 to strong brine, pH, and other chemical conditions, we conducted a bioassay using clinically healthy Penaeus vannamei individuals. DIV1 inoculum was exposed to various chemical conditions, and the infectivity of DIV1 was determined through intramuscular injection. The results showed that DIV1 lost its infectivity when exposed to strong brine, specifically in a 3 mol/L NaCl solution for a duration of 1 h. Moreover, DIV1 was found to be inactivated within 1 h when subjected to pH levels below 3.1 or above 9.6. Additionally, both Triton X-100 and 1 % formaldehyde demonstrated the ability to inactivate DIV1. These results provide valuable insights into the tolerance of DIV1 towards certain chemical factors, serving as a reference for the establishment of biosecurity measures against DIV1.


Assuntos
Penaeidae , Animais , Octoxinol , Injeções Intramusculares
3.
Proc Natl Acad Sci U S A ; 117(1): 271-277, 2020 01 07.
Artigo em Inglês | MEDLINE | ID: mdl-31848246

RESUMO

Brown planthopper (BPH) is one of the most destructive insects affecting rice (Oryza sativa L.) production. Phenylalanine ammonia-lyase (PAL) is a key enzyme involved in plant defense against pathogens, but the role of PAL in insect resistance is still poorly understood. Here we show that expression of the majority of PALs in rice is significantly induced by BPH feeding. Knockdown of OsPALs significantly reduces BPH resistance, whereas overexpression of OsPAL8 in a susceptible rice cultivar significantly enhances its BPH resistance. We found that OsPALs mediate resistance to BPH by regulating the biosynthesis and accumulation of salicylic acid and lignin. Furthermore, we show that expression of OsPAL6 and OsPAL8 in response to BPH attack is directly up-regulated by OsMYB30, an R2R3 MYB transcription factor. Taken together, our results demonstrate that the phenylpropanoid pathway plays an important role in BPH resistance response, and provide valuable targets for genetic improvement of BPH resistance in rice.


Assuntos
Hemípteros/efeitos dos fármacos , Oryza/enzimologia , Oryza/metabolismo , Fenilalanina Amônia-Liase/metabolismo , Fenilalanina Amônia-Liase/farmacologia , Doenças das Plantas/imunologia , Fatores de Transcrição/metabolismo , Animais , DNA de Plantas/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Técnicas de Silenciamento de Genes , Genes de Plantas , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/fisiologia , Lignina/metabolismo , Oryza/genética , Oryza/imunologia , Fenilalanina Amônia-Liase/genética , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Plantas Geneticamente Modificadas/genética , Ácido Salicílico/metabolismo
4.
Small ; 18(13): e2106863, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35076167

RESUMO

Carbonized polymer dots (CPDs) have received tremendous attention during the last decade due to their excellent fluorescent properties and catalytic performance. Doping CPDs with transition metal atoms accelerates the local electron flow in CPDs and improves the fluorescent properties and catalytic performance of the CPDs. However, the binding sites and the formation mechanisms of the transition-metal-atom-doped CPDs remain inconclusive. In this work, Mn2+ -ion-doped CPDs (Mn-CPDs) are synthesized by the hydrothermal method. The Mn2+ ions form MnO bonds that bridge the sp2 domains of carbon cores and increases the effective sp2 domains in the Mn-CPDs, which redshifts the fluorescence emission peak of the Mn-CPDs slightly. The Mn2+ ions form covalent bonds in the CPDs and remedy the oxygen vacancies of the CPDs, which cuts off the non-radiative-recombination process of the Mn-CPDs and increases the quantum yield of the Mn-CPDs to 70%. Furthermore, the MnO bonds accelerate the electron flow between adjacent sp2 domains and enhances the electron transport in the Mn-CPDs. Thus, the Mn-CPDs demonstrate excellent catalytic performance to activate hydrogen peroxide (H2 O2 ) and produce hydroxyl radicals (•OH) to degrade methylene blue (MB) and rhodamine B (RhB).


Assuntos
Polímeros , Pontos Quânticos , Carbono/química , Transporte de Elétrons , Fluorescência , Polímeros/química , Pontos Quânticos/química
5.
Nanomedicine ; 41: 102517, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35032629

RESUMO

Mesenchymal stem cells (MSCs) are promising in idiopathic pulmonary fibrosis (IPF) therapy. However, low survival rate and ambiguous behavior of MSCs after transplantation impede their clinical translation. To this end, we have developed a new strategy to improve the survival rate and monitor the behavior of the transplanted MSCs simultaneously. In our strategy, nintedanib, a tyrosine kinase inhibitor, is employed to protect the human MSCs (hMSCs) from excessive oxidative stress responses and inflammatory environment in the damaged lung. Moreover, by labeling of the transplanted hMSCs with a computed tomography (CT) nanotracer, Au nanoparticles functionalized with polyethylenimine (PEI) and polyethylene glycol (PEG) (Au@PEI@PEG), in combination with red-emitting firefly luciferase (RfLuc), in vivo CT/bioluminescence (BL) dual-modal imaging tracking of the location, distribution, and survival of the transplanted hMSCs in presence of nintedanib were achieved, which facilitates the profound understanding of the role the stem cells play in IPF therapy.


Assuntos
Fibrose Pulmonar Idiopática , Células-Tronco Mesenquimais , Nanopartículas Metálicas , Ouro , Humanos , Fibrose Pulmonar Idiopática/diagnóstico por imagem , Fibrose Pulmonar Idiopática/tratamento farmacológico , Indóis , Luciferases de Vaga-Lume , Nanopartículas Metálicas/uso terapêutico , Polietilenoglicóis , Polietilenoimina , Tomografia Computadorizada por Raios X
6.
Nano Lett ; 21(24): 10279-10283, 2021 12 22.
Artigo em Inglês | MEDLINE | ID: mdl-34851648

RESUMO

Because of the extraordinary properties including high atomic numbers and large µτ products, metal halide perovskites have been widely employed and used for radiation detecting. Cs4PbI6 material has a high X-ray attenuation coefficient and excellent electrical properties that have a good potential in X-ray detection applications. Here, we have designed a flexible polymer-encapsulated Au/Cs4PbI6/Au X-ray detector with outstanding sensitivity of 256.20 µC Gy-1 cm-2 irradiated by 30 keV X-ray at 10 V bias, long-time stability, and durable flexibility without obvious degradation after bending for 600 cycles. These features demonstrate that this polymer-encapsulated durable flexible and sensitive X-ray detector could open a new possibility for next-generation radiation applications in dosimeter, imaging technologies.


Assuntos
Metais , Polímeros , Radiografia , Raios X
7.
BMC Oral Health ; 22(1): 366, 2022 08 26.
Artigo em Inglês | MEDLINE | ID: mdl-36028869

RESUMO

BACKGROUND: Peri-implantitis of tooth seriously affects the life quality of patients. This study aimed to investigate the role of HSP90AA1 in the inflammatory of human gingival fibroblasts (HGFs) induced by porphyromonas gingivalis lipopolysaccharide (Pg-LPS), and to provide a potential therapeutic target for clinical treatment of peri-implantitis. METHODS: Pg-LPS (0.1, 1, 10 µg/mL) was used to construct the inflammatory model of HGFs to evaluate the effect of Pg-LPS on HGFs. Then HSP90AA1-siRNA was transfected to construct HSP90AA1 low expression HGFs cell line, and 3-MA was also added. After that, cell viability, apoptosis, the contents of inflammatory cytokines were detected by CCK-8, flow cytometry and ELISA assay, respectively. Intracellular ROS, the expressions of HSP90α, HSP90ß were detected by immunofluorescence. The levels of HSP90AA1, p-NF-κB p65/NF-κB p65, LC3 II/I, ATG5, Beclin-1 and TLR protein were detected by western blot. RESULTS: Pg-LPS treatment didn't affect the viability of HGFs cells, but induced the cell apoptosis and ROS generation, increased the contents of IL-1ß, IL-6, TNF-α, and the protein expressions of HSP90AA1, p-NF-κBp65/NF-κBp65, LC3II/I, ATG5, and Beclin-1 in HGFs. While HSP90AA1-siRNA transfected into Pg-LPS induced HGFs significantly reduced the HSP90AA1, HSP90α, HSP90ß expression, decreased the inflammatory factors, ROS generation, cell apoptosis rate, and autophagy-related proteins and TLR2/4 protein levels. What's more, the addition of autophagy inhibitor 3-MA further promote the effect of HSP90AA1-siRNA on Pg-LPS treated HGFs. CONCLUSIONS: This study showed that HSP90AA1 promoted the inflammatory response of Pg-LPS induced HGFs by regulating autophagy. The addition of 3-MA further confirmed that autophagy may mediate siHSP90AA1 to enhance the inflammatory response.


Assuntos
Fibroblastos , Proteínas de Choque Térmico HSP90 , Peri-Implantite , Porphyromonas gingivalis , Autofagia , Proteína Beclina-1 , Células Cultivadas , Fibroblastos/patologia , Gengiva , Proteínas de Choque Térmico HSP90/genética , Humanos , Inflamação , Lipopolissacarídeos , NF-kappa B , RNA Interferente Pequeno , Espécies Reativas de Oxigênio
8.
Nanomedicine ; 33: 102358, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33484882

RESUMO

Virus-like particle (VLP) vaccines have become one of the dominant vaccine candidates for foot-and-mouth disease (FMD). To further enhance the immunogenicity of VLP vaccines, gold nanocages (AuNCs) were selected as an adjuvant for the vaccine. Our experiments demonstrated that AuNCs had little biotoxicity in vivo and in vitro and improved the uptake of VLP in BHK-21 and RAW264.7 cell lines. The VLP-AuNCs activated DCs mainly through toll-like receptor 4 (TLR4) and promoted the secretion of IL-6, IL-1ß, and TNF-α. The conjugation of VLP and AuNCs triggered a strong immune response against FMD virus (FMDV) in mice and guinea pigs. The VLP-AuNCs significantly enhanced the proliferation of CD8+ T cells (P < 0.05) and the secretion of cellular immune-related cytokines (IFN-γ, P < 0.05; IL-12p70, P < 0.01) compared with VLP. The present study demonstrated that AuNCs, as a great potential adjuvant for FMDV VLP vaccines, significantly enhance the immune response.


Assuntos
Adjuvantes Imunológicos/química , Portadores de Fármacos/química , Febre Aftosa/prevenção & controle , Ouro/química , Nanopartículas Metálicas/química , Vacinas de Partículas Semelhantes a Vírus/química , Vacinas Virais/química , Adjuvantes Imunológicos/farmacologia , Animais , Melhoramento Biomédico , Linfócitos T CD8-Positivos , Permeabilidade da Membrana Celular , Proliferação de Células , Citocinas/metabolismo , Composição de Medicamentos , Liberação Controlada de Fármacos , Feminino , Vírus da Febre Aftosa , Cobaias , Camundongos , Camundongos Endogâmicos BALB C , Testes de Neutralização , Células RAW 264.7 , Vacinas de Partículas Semelhantes a Vírus/farmacologia , Vacinas Virais/farmacologia
9.
Br J Clin Pharmacol ; 85(12): 2714-2720, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31396983

RESUMO

AIMS: Type 2 diabetes mellitus (T2DM) is commonly complicated by renal impairment. Polyethylene glycol loxenatide (PEX168) is a novel long-acting glucagon-like peptide-1 receptor agonist for T2DM. PEX168 pharmacokinetics was studied to identify requirements for dose-modification in T2DM complicated by renal impairment. METHODS: This was a single-centre, open-labelled, parallel-group, single-dose, phase I clinical trial of patients with mild and moderate renal impairment, and with or without T2DM. Age-, sex- and body mass index-matched subjects with normal renal function, and with or without T2DM were recruited as controls. Subjects received a single abdominal subcutaneous injection of PEX168 200 µg. Pharmacokinetic samples were taken at 0, 24, 48, 72, 96, 120, 144, 216, 312, 480, 648 and 720 hours. RESULTS: Twenty-three patients were included in the pharmacokinetics analysis. Vz/F and CL/F were lower in the moderate impairment group than in the other groups. The mean t1/2 (163 hours) in the moderate impairment group was prolonged compared to the mild impairment (117 hours) and normal (121 hours) groups. AUC0-inf increased by 13 and 100.7% in patients with mild and moderate renal impairment, respectively. Most adverse events were mild gastrointestinal disorders, with only 1 serious adverse event observed. CONCLUSION: A single dose of 200 µg of PEX168 was in general well tolerated in patients with renal impairment. The in vivo clearance rate of PEX168 in patients with moderate renal impairment is slower than in patients with mild renal impairment and normal renal function and dose adjustment might be required (ClinicalTrials.org #NCT02467790).


Assuntos
Diabetes Mellitus Tipo 2/sangue , Nefropatias Diabéticas/sangue , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Hipoglicemiantes/sangue , Rim/metabolismo , Peptídeos/sangue , Adulto , Área Sob a Curva , Relação Dose-Resposta a Droga , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/etiologia , Feminino , Humanos , Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/efeitos adversos , Rim/fisiopatologia , Masculino , Pessoa de Meia-Idade , Peptídeos/administração & dosagem , Peptídeos/efeitos adversos , Polietilenoglicóis/administração & dosagem , Polietilenoglicóis/efeitos adversos
10.
J Oral Maxillofac Surg ; 77(1): 184-194, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30218654

RESUMO

PURPOSE: To assess the possible benefits of elective neck dissection (END) in patients with squamous cell carcinoma (SCC) of the oral cavity and clinically N0 neck. MATERIALS AND METHODS: Medline, Embase, the China National Knowledge Infrastructure, and the Wan Fang Database were systematically searched. A meta-analysis was performed to evaluate the possible benefits of END to such patients. RESULTS: Six prospective studies involving 865 patients fulfilled the inclusion criteria. Meta-analysis of all included studies showed that END substantially lowered the risk of regional recurrences (risk ratio [RR] = 0.27; 95% confidence interval [CI], 0.21-0.36) in the fixed-effect model compared with observation only. Three of the 6 included studies showed that the specific death rate related to regional recurrences was lower in the END group than in the observation group in the fixed-effect model (RR = 0.35; 95% CI, 0.19-0.65). The mean metastasis rate of occult cervical lymph node was 30.27% (standard deviation, 9.42%). When the fixed-effect model was applied, 4 of the 6 included studies showed less recurrence in the END group compared with the observation group (RR = 0.53; 95% CI, 0.44-0.64). CONCLUSIONS: END substantially decreases recurrences and deaths related to regional recurrences in early-stage SCC of the oral cavity with clinically N0 neck, especially SCC of the oral tongue and floor of the mouth, which is necessary for such patients.


Assuntos
Carcinoma de Células Escamosas , Neoplasias Bucais , Carcinoma de Células Escamosas/cirurgia , China , Humanos , Neoplasias Bucais/cirurgia , Esvaziamento Cervical , Recidiva Local de Neoplasia , Estadiamento de Neoplasias , Estudos Prospectivos , Estudos Retrospectivos , Resultado do Tratamento
11.
Opt Lett ; 41(6): 1233-6, 2016 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-26977677

RESUMO

A nanometeric plasmonic filter with a symmetrical multiple-teeth-shaped structure is investigated theoretically and numerically. A tunable wide bandgap is achievable by adjusting the depth and number of teeth. This phenomenon can be attributed to the interference superposition of the reflected and transmitted waves from each tooth. Moreover, the effects of varying the number of identical teeth are also discussed. It is found that the bandgap width increases continuously with the increasing number of teeth. The finite difference time domain method is used to simulate and compute the coupling of surface plasmon polariton waves with different structures in this Letter. The plasmonic waveguide filter that we propose here may have meaningful applications in ultra-fine spectrum analysis and high-density nanoplasmonic integration circuits.


Assuntos
Dispositivos Ópticos , Luz , Fenômenos Ópticos
12.
J Sep Sci ; 39(18): 3578-85, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27443574

RESUMO

A quick and specific pretreatment method based on a series of extraction clean-up disks, consisting of molecularly imprinted polymer monoliths and C18 adsorbent, was developed for the specific enrichment of salbutamol and clenbuterol residues in food. The molecularly imprinted monolithic polymer disk was synthesized using salbutamol as a template through a one-step synthesis process. It can simultaneously and specifically recognize salbutamol and clenbuterol. The monolithic polymer disk and series of C18 disks were assembled with a syringe to form a set of tailor-made devices for the extraction of target molecules. In a single run, salbutamol and clenbuterol can be specifically extracted, cleaned, and eluted by methanol/acetic acid/H2 O. The target molecules, after a silylation derivatization reaction were detected by gas chromatography-mass spectrometry. The parameters including solvent desorption, sample pH, and the cycles of reloading were investigated and discussed. Under the optimized extraction and clean-up conditions, the limits of detection and quantitation were determined as 0.018-0.022 and 0.042-0.049 ng/g for salbutamol and clenbuterol, respectively. The assay described was convenient, rapid, and specific; thereby potentially efficient in the high-throughput analysis of ß2 -agonists residues in real food samples.


Assuntos
Agonistas Adrenérgicos beta/isolamento & purificação , Albuterol/isolamento & purificação , Clembuterol/isolamento & purificação , Contaminação de Alimentos/análise , Carne/análise , Extração em Fase Sólida/métodos , Agonistas Adrenérgicos beta/análise , Adsorção , Albuterol/análise , Animais , Clembuterol/análise , Cromatografia Gasosa-Espectrometria de Massas , Impressão Molecular , Polímeros/síntese química , Polímeros/química , Extração em Fase Sólida/instrumentação , Suínos
13.
BMC Infect Dis ; 14: 337, 2014 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-24939221

RESUMO

BACKGROUND: Hand, foot and mouth disease (HFMD), a virus-induced infectious disease that usually affects infants and children, has an increased incidence in China in recent years. This study attempted to investigate the role of the Notch signaling pathway in the pathogenesis of HFMD. METHODS: Eighty-two children diagnosed with HFMD were enrolled into this study. The HFMD group was further divided into the uncomplicated HFMD and HFMD with encephalitis groups. The control group included 40 children who underwent elective surgery for treatment of inguinal hernias. RESULTS: Children with HFMD displayed significantly reduced CD3+, CD3+CD4+ and CD3+CD8+ cell subsets, but substantially enhanced CD3-CD19+ cell subset (p<0.05 versus control subjects). The expression levels of Notch ligands Dll1 and Dll4 in the peripheral blood of the HFMD group were significantly higher than those in the control group (p<0.05). There were statistically significant differences in CD3+, CD3+CD4+ and CD3-CD19+ cell subsets, but not in Notch ligand expression, between the uncomplicated HFMD and HFMD with encephalitis groups. Dll4 expression in HFMD subjects correlated negatively with the CD3+ and CD3+CD8+ cell subsets (p<0.05), but positively with the CD3-CD19+ cell subset (p<0.05). Furthermore, Dll4 expression in HFMD with encephalitis subjects correlated positively with total white blood cell (WBC) counts and total protein contents in cerebrospinal fluid (CSF) (p<0.05). CONCLUSIONS: The Notch ligand Dll4 exhibits a strong correlation with the CD3+, CD3+CD8+ and CD3-CD19+ cell subsets in children with HFMD, indicating that the Notch signaling may be involved in the development of HFMD by affecting the number and status of peripheral lymphocytes.


Assuntos
Doença de Mão, Pé e Boca/genética , Peptídeos e Proteínas de Sinalização Intercelular/genética , Criança , Pré-Escolar , China , Encefalite/genética , Encefalite/imunologia , Feminino , Doença de Mão, Pé e Boca/sangue , Doença de Mão, Pé e Boca/imunologia , Humanos , Lactente , Peptídeos e Proteínas de Sinalização Intercelular/imunologia , Contagem de Leucócitos , Masculino , Subpopulações de Linfócitos T/imunologia
14.
Int J Biol Macromol ; 266(Pt 1): 131175, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38552696

RESUMO

Myocardial ischemia-reperfusion injury (MIRI) significantly contributes to the high incidence of complications and mortality associated with acute myocardial infarction. Recently, injectable electroconductive hydrogels (IECHs) have emerged as promising tools for replicating the mechanical, electroconductive, and physiological characteristics of cardiac tissue. Herein, we aimed to develop a novel IECH by incorporating irbesartan as a drug delivery system (DDS) for cardiac repair. Our approach involved merging a conductive poly-thiophene derivative (PEDOT: PSS) with an injectable dual-network adhesive hydrogel (DNAH) comprising a catechol-branched polyacrylamide network and a chitosan-hyaluronic acid covalent network. The resulting P-DNAH hydrogel, benefitting from a high conducting polymer content, a chemically crosslinked network, a robust dissipative matrix, and dynamic oxidation of catechol to quinone exhibited superior mechanical strength, desirable conductivity, and robust wet-adhesiveness. In vitro experiments with the P-DNAH hydrogel carrying irbesartan (P-DNAH-I) demonstrated excellent biocompatibility by cck-8 kit on H9C2 cells and a rapid initial release of irbesartan. Upon injection into the infarcted hearts of MIRI mouse models, the P-DNAH-I hydrogel effectively inhibited the inflammatory response and reduced the infarct size. In conclusion, our results suggest that the P-DNAH hydrogel, possessing suitable mechanical properties and electroconductivity, serves as an ideal IECH for DDS, delivering irbesartan to promote heart repair.


Assuntos
Resinas Acrílicas , Quitosana , Hidrogéis , Traumatismo por Reperfusão Miocárdica , Irbesartana/administração & dosagem , Traumatismo por Reperfusão Miocárdica/tratamento farmacológico , Quitosana/administração & dosagem , Quitosana/química , Resinas Acrílicas/administração & dosagem , Resinas Acrílicas/química , Hidrogéis/administração & dosagem , Hidrogéis/química , Hidrogéis/toxicidade , Condutividade Elétrica , Elasticidade , Injeções , Linhagem Celular , Animais , Ratos , Modelos Animais de Doenças , Camundongos , Masculino , Camundongos Endogâmicos C57BL , Sobrevivência Celular/efeitos dos fármacos
15.
Bone ; 180: 116990, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38141748

RESUMO

Numerous studies have demonstrated that estrogen deficiency inhibit the proliferation and differentiation of pre-osteoblasts in skeleton by affecting osteogenic signaling, lead to decreased bone mass and impaired regeneration. To explore the mechanisms maintaining bone regeneration under estrogen deficiency, we randomly selected 1102 clinical cases, in which female patients aged between 18 and 75 have underwent tooth extraction in Stomatological Hospital of Tongji University, there is little difference in the healing effect of extraction defects, suggesting that to some extent, the regeneration of jawbone is insensitive to the decreased estrogen level. To illuminate the mechanisms promoting jawbone regeneration under estrogen deficiency, a tooth extraction defect model was established in the maxilla of female rats who underwent ovariectomy (OVX) or sham surgery, and jawbone marrow stromal cells (BMSCs) were isolated for single-cell sequencing. Further quantitative PCR, RNA interference, alizarin red staining, immunohistochemistry and western blotting experiments demonstrated that in the context of ovariectomy, maxillary defects promoted G protein-coupled estrogen receptor 1 (Gper1) expression, stimulate downstream cAMP/PKA/pCREB signaling, and facilitate cell proliferation, and thus provided sufficient progenitors for osteogenesis and enhanced the regeneration capacity of the jawbone. Correspondingly, the heterozygous deletion of the Gper1 gene attenuated the phosphorylation of CREB, led to decreased cell proliferation, and impaired the restoration of maxillary defects. This study demonstrates the importance of Gper1 in maintaining jawbone regeneration, especially in the context of estrogen deficiency.


Assuntos
Regeneração Óssea , Osteogênese , Humanos , Ratos , Feminino , Animais , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Diferenciação Celular , Arcada Osseodentária , Estrogênios
16.
Artigo em Inglês | MEDLINE | ID: mdl-38498783

RESUMO

PURPOSE: To explore the contribution of paired-related homeobox 1-positive cells to the implant-induced osseointegration process in adult alveolar bone and the potential underlying mechanisms. MATERIALS AND METHODS: Cre recombinase-induced lineage tracing and cell ablation were conducted in a murine dental implant model. Scratch and transwell assays were used to assess MC3T3-E1 cell migration after paired-related homeobox 1 overexpression. Single-cell RNA sequencing were applied to identify potential genes involved in pairedrelated homeobox 1-positive cells-driven osteogenesis. RESULTS: Paired-related homeobox 1- positive cells were observed to accumulate in the peri-implant area in a time-dependent manner. The number of these cells were found to reach its maximum on day 14. Osseointegration in mice were noticeably impaired after ablation of paired-related homeobox 1-positive cells. Further, it was discovered that paired-related homeobox 1 promotes MC3T3- E1 cell migration, a process which is indispensable for sound healing of peri-implant tissue. Finally, Semaphorin 3C was detected exclusively and abundantly expressed by paired-related homeobox 1-positive cells. Knockdown of semaphorin 3C in paired-related homeobox 1- positive cells significantly weakened their osteogenic potential. CONCLUSION: Our data suggest that paired-related homeobox 1-positive cells contribute to the osseointegration process under stress stimulation and semaphorin 3C may play a critical role in paired-related homeobox 1- positive cell-driven osteogenesis. Paired-related homeobox 1 could significantly promote MC3T3-E1 cell migration.

17.
Sci Total Environ ; 920: 171046, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38369151

RESUMO

Food security, water scarcity, and excessive fossil energy use pose considerable challenges to sustainable agriculture. To understand how rain-fed farming systems on the Loess Plateau, China, reconcile yield increases with ecological conservation, we conducted an integrated evaluation based on the denitrification-decomposition (DNDC) model, agricultural statistics data using the Food-Energy-Water (FEW) nexus indicator. The results showed that maize yields with ridge-furrow plastic film mulching (PFM) were 3479, 8942, and 11,124 kg ha-1 under low (50 kg N ha-1), medium (200 kg N ha-1), and high (350 kg N ha-1) nitrogen (N) fertilizer rates, respectively, and that PFM increased yield and water use efficiency (WUE) by 110-253 % and 166-205 % compared to using no mulching (control, CK), respectively. Plastic film mulching also increased net energy (126-436 %), energy use efficiency (81-578 %), energy productivity (100-670 %), and energy profitability (126-994 %), and nitrogen fertilizer, compound fertilizer, and diesel fuel consumption by agricultural machinery were the main energy inputs. The PFM system reduced water consumption during the maize growing season and the green water footprint and gray water footprint decreased by 66-74 % and 44-68 %, respectively. The FEW nexus indicator, based on a high production at low environmental cost scenario, was greater under the PFM system and had the widest spatial distribution area at the medium-N application rate. Among the environmental factors, the nexus indicator was negatively correlated with precipitation (-0.37), air temperature (-0.36), and the aridity index (-0.36), but positively correlated with elevation (0.17). Our results suggest that the PFM system promotes resource-saving while increasing yields and moves dryland agriculture in an environmentally friendly direction, thus promoting the sustainable development of agroecosystems.


Assuntos
Solo , Água , Água/análise , Fertilizantes , Agricultura/métodos , Zea mays , China , Nitrogênio/análise , Plásticos
18.
J Bone Miner Res ; 39(5): 611-626, 2024 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-38477792

RESUMO

The impaired bone healing in tooth extraction sockets due to periodontitis presents a major obstacle to restoring oral health. The mechanisms regulating the osteogenic capacity of jawbone-derived stromal cells in the periodontitis microenvironment remain elusive. Leptin receptor (LepR) expressing stromal cells, which largely overlap with Cxcl12-abundant reticular (CAR) cells in bone tissue, rapidly proliferate and differentiate into bone-forming cells during extraction socket healing to support alveolar bone repair. In this study, we identify that CCRL2 is significantly expressed and inhibits osteogenesis in LepR+/CAR cells of alveolar bones with periodontitis. The Ccrl2-KO mice exhibit significant improvements in bone healing in extraction sockets with periodontitis. Specifically, the binding of CCRL2 to SFRP1 on the surface of LepR+/CAR cells can amplify the suppressive effect of SFRP1 on Wnt signaling under inflammation, thus hindering the osteogenic differentiation of LepR+/CAR cells and resulting in poor bone healing in extraction sockets with periodontitis. Together, we clarify that the CCRL2 receptor of LepR+/CAR cells can respond to periodontitis and crosstalk with Wnt signaling to deteriorate extraction socket healing.


The impaired bone healing in tooth extraction sockets due to periodontitis presents a major obstacle to restoring oral health. Alterations in the cellular activity of LepR+/CAR cells, an essential stromal cell population for extraction socket healing, in the periodontitis microenvironment have yet to be determined. In this study, we identify that CCRL2, as a potent agent of inflammation-bone crosstalk, is significantly expressed and inhibits osteogenesis in LepR+/CAR cells of alveolar bones with periodontitis. Specifically, the binding of CCRL2 to SFRP1 on the surface of LepR+/CAR cells can amplify the suppressive effect of SFRP1 on the Wnt/ß-catenin signaling under inflammation, thus hindering the osteogenic differentiation of LepR+/CAR cells and resulting in poor bone healing in tooth extraction sockets with periodontitis.


Assuntos
Osteogênese , Periodontite , Receptores para Leptina , Via de Sinalização Wnt , Animais , Periodontite/metabolismo , Periodontite/patologia , Receptores para Leptina/metabolismo , Receptores para Leptina/deficiência , Receptores para Leptina/genética , Camundongos , Camundongos Knockout , Células Estromais/metabolismo , Células Estromais/patologia , Masculino , Humanos , Processo Alveolar/patologia , Processo Alveolar/metabolismo , Cicatrização , Proteínas de Membrana/metabolismo
19.
Bioresour Technol ; 393: 130171, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38086460

RESUMO

The study reports the economic and sustainable syntheses of a lignin-based porous carbon (LPC) for CO2 capture application. The pH values of hydrothermal solution affected the polymerization and aromatization of spheroidization, with morphological changes from blocky to microsphere. In addition, the reliable mechanisms of CO2 adsorption were proposed by combining experiments with Gaussian16 simulations based on DFT. The electrostatic attraction of oxygen-containing functional groups and the diffusivity resistance of CO2 in the pores are the key factors for the CO2 adsorption. ​The carboxyl groups have the strongest electrostatic attraction to CO2. LPC-pH 1 has the highest carboxyl group content, possessing a CO2 adsorption capacity of up to 5.10 mmol/g at 0℃, 1 bar. Furthermore, CO2 diffusion resistance became a main factor as the adsorption temperature increases. The innovative combination of quantum chemical calculations and microscopic properties provides a viable pathway for an insight into the future control of lignin-based carbon formation.


Assuntos
Dióxido de Carbono , Lignina , Dióxido de Carbono/química , Lignina/química , Adsorção , Porosidade , Microesferas , Concentração de Íons de Hidrogênio
20.
Biofabrication ; 16(4)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-38914075

RESUMO

Accurate reproduction of human intestinal structure and functionin vitrois of great significance for understanding the development and disease occurrence of the gut. However, mostin vitrostudies are often confined to 2D models, 2.5D organ chips or 3D organoids, which cannot fully recapitulate the tissue architecture, microenvironment and cell compartmentalization foundin vivo. Herein, a centimeter-scale intestine tissue that contains intestinal features, such as hollow tubular structure, capillaries and tightly connected epithelium with invivo-likering folds, crypt-villi, and microvilli is constructed by 3D embedding bioprinting. In our strategy, a novel photocurable bioink composed of methacrylated gelatin, methacrylated sodium alginate and poly (ethylene glycol) diacrylate is developed for the fabrication of intestinal model. The Caco-2 cells implanted in the lumen are induced by the topological structures of the model to derive microvilli, crypt-villi, and tight junctions, simulating the intestinal epithelial barrier. The human umbilical vein endothelial cells encapsulated within the model gradually form microvessels, mimicking the dense capillary network in the intestine. This intestine-like tissue, which closely resembles the structure and cell arrangement of the human gut, can act as a platform to predict the therapeutic and toxic side effects of new drugs on the intestine.


Assuntos
Bioimpressão , Capilares , Células Endoteliais da Veia Umbilical Humana , Intestinos , Impressão Tridimensional , Humanos , Células CACO-2 , Capilares/citologia , Intestinos/citologia , Engenharia Tecidual , Alginatos/química , Polietilenoglicóis/química , Alicerces Teciduais/química , Mucosa Intestinal/citologia , Gelatina/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA