RESUMO
Polymeric vehicles often exhibit batch-to-batch variations due to polydispersity, limiting their reproducibility for biomedical applications. In contrast, polyhedral oligomeric silsesquioxane (POSS) has emerged as an attractive candidate for drug delivery due to its precise chemical structure and rigid molecular shape. A promising strategy to enhance drug efficacy while reducing systemic toxicity is the development of multi-stimuli-responsive delivery systems capable of targeted drug release at a disease site. Herein, we developed a drug delivery platform based on POSS-polymer conjugates. By functionalizing the POSS with amino groups and establishing B-N coordination with boronic acids, the nanoparticles (NPs) exhibit responsive behavior to stimuli, including adenosine-5'-triphosphate (ATP), acidic pH, and nucleophilic reagents. We successfully encapsulated two boronic acid-containing molecules: tetraphenylethylene (TPE), serving as a fluorescent probe, and bortezomib (BTZ), an anticancer drug. The TPE@NPs were employed to visualize the cellular uptake of NPs by tumor cells, while the BTZ@NPs exhibited increased cytotoxicity in tumor cells compared with normal cells. This POSS-PEG conjugate offers a nanoparticle platform for encapsulating versatile boronic acid-containing molecules, thereby enhancing drug efficacy while minimizing systemic toxicity. Given the wide-ranging applications of boronic acid-containing molecules in biomedicine, our platform holds significant promise for the development of intelligent drug delivery systems for diagnostics and therapeutics.
Assuntos
Antineoplásicos , Nanopartículas , Ácidos Borônicos/química , Reprodutibilidade dos Testes , Antineoplásicos/farmacologia , Antineoplásicos/química , Sistemas de Liberação de Medicamentos , Nanopartículas/química , Bortezomib/farmacologia , Polímeros/químicaRESUMO
Organic solar cells (OSCs) have achieved great progress, driven by the rapid development of wide bandgap electron donors and narrow bandgap non-fullerene acceptors (NFAs). Among a large number of electron-accepting (A) building blocks, thiazole (Tz) and its derived fused heterocycles have been widely used to construct photovoltaic materials, especially conjugated polymers. Benefiting from the electron deficiency, rigidity, high planarity, and enhanced intra/intermolecular interactions of Tz-containing heterocycles, some related photovoltaic materials exhibit proper energy levels, optimized molecular aggregation, and active layer morphology, leading to excellent photovoltaic performance. This review focuses on the progress of Tz-based photovoltaic materials in the field of OSCs. First, the Tz-based donor and acceptor photovoltaic materials are reviewed. Then, the materials based on promising Tz-containing heterocycles, mainly including thiazolo[5,4-d]thiazole (TzTz), benzo[1,2-d:4,5-d']bis(thiazole) (BBTz), and benzo[d]thiazole (BTz) are summarized and discussed. In addition, the new emerging Tz-fused structures and their application in OSCs are introduced. Finally, perspectives and outlooks for the further development of Tz-containing heterocycle-based photovoltaic materials are proposed.
Assuntos
Elétrons , Polímeros , TiazóisRESUMO
Insect gut bacteria play an essential role in the nutritional metabolism, growth, and development of insects. Grasshoppers (Orthoptera) are cellulose-rich plant-feeding pests. Although the biological potential of grasshopper gut microorganisms to assist cellulose decomposition is well established, microbial resources for efficient degradation of cellulose biomass are still scarce and need to be developed. In this study, we used selective media to isolate cellulose-degrading bacteria from the intestines of Atractomorpha sinensis, Trilophidia annulata, Sphingonotus mongolicus, and Calliptamus abbreviatus. Phylogenetic analysis based on the maximum likelihood method using 16S rDNA sequencing sequences to identify bacteria revealed the isolation of 11 strains belonging to 3 genera, including Klebsiella, Aeromonas, and Bacillus. The degradability of the isolates to cellulose was then determined by the DNS colorimetric method, and the results showed that Bacillus had the highest degradation rate. The elucidation of microbial cellulose degradation capacity in grasshoppers not only contributes to the understanding of multiple plant-insect-microbe interactions, but also provides a valuable microbial resource for solving the biomass conversion of cellulose species problem.
Assuntos
Gafanhotos , Animais , Gafanhotos/metabolismo , Filogenia , Celulose/metabolismo , Bactérias/genética , BiomassaRESUMO
BACKGROUND/AIM: Injuries to the primary dentition affect children's esthetics, function, and mental health. They may also affect the development of the permanent teeth. The knowledge of dentists about deciduous tooth trauma is rarely evaluated. The aim of this study was to evaluate the knowledge and attitude of dentists in China regarding traumatic dental injuries to primary teeth. MATERIAL AND METHODS: A self-administered online questionnaire containing questions on demographic data and knowledge based on a clinical scenario was given to a purposive sample of dentists, recruited by a non-probability convenience sampling method. The chi-square test was used for statistical analysis, with the significance level set at P <.05. RESULTS: A total of 394 out of 409 dentists provided valid data. There was no significant difference in demographic data. Questions about the treatment of hard dental tissue injuries in primary teeth presented a correct-response rate of 66.4%, with the highest correct-response rate for enamel fracture (n = 368, 93.4%) and lowest for complicated crown-root fracture with pulp exposure (n = 104, 26.4%). Questions about treatment of luxation injuries in primary teeth presented a correct-response rate of 66.6%, with subluxation presenting the highest correct-response rate (n = 391, 99.2%). Factors associated with higher correct-response rates were specialist disciplines, educational qualifications, workplaces, experience of injured teeth treated, and educational experience about primary tooth trauma. No significant differences were found in the correct-response rates of dentists with different years of work experience. Lack of cooperation from children was considered a major obstacle for treatment. Special lectures and Internet courses were the most preferred methods of obtaining knowledge. CONCLUSION: The results suggest that it is necessary to enhance dental trauma education for dentists in China. More attention needs to be paid to trauma in primary dentition to ensure adequate treatment for traumatized primary teeth.
Assuntos
Avulsão Dentária , Traumatismos Dentários , Criança , China , Estudos Transversais , Odontólogos , Humanos , Avulsão Dentária/terapia , Traumatismos Dentários/terapia , Dente DecíduoRESUMO
Understanding the relationship between the structure of solid foods and their oral processing is paramount for enhancing features such as texture and taste and for improving health-related factors such as management of body weight or dysphagia. This paper discusses the main aspects of the oral processing of solid foods across different categories: (1) oral physiology related to chewing, (2) in-mouth food transformation, (3) texture perception, and (4) taste perception, and emphasis is placed on unveiling the underlying mechanisms of how food structure influences the oral processing of solid foods; this is exemplified by comparing the chewing behaviors for a number of representative solid foods. It highlights that modification of the texture/taste of food based on food structure design opens up the possibility for the development of food products that can be applied in the management of health.
Assuntos
Alimentos Especializados , Percepção Gustatória , Mastigação , Boca , PaladarRESUMO
Microscopic structures have a significant influence on the properties of ceramics. The development of macromolecular self-assembly has allowed for control over microscopic structures of ceramics to prepare ceramics with diverse compositions and ordered nanostructures. Herein, recent progress in the preparation of ceramics with periodically ordered nanostructures guided by phase-separated macromolecules are reviewed, which can be summarized as a general strategy termed the "macromolecule-guided strategy." Moreover, two different subcategories, namely, the macromolecule-templated method and the macromolecule-precursor method, are illustrated. In the former method, amphiphilic macromolecules are used as templates to guide the assembly of inorganic species into ordered nanostructures, which are subsequently converted into ceramics; in the latter method, amphiphilic macromolecules containing non-volatile elements are used as the single-source precursors for ordered ceramics. It is believed that the unique diversity and tunable features of macromolecular self-assembly might offer unprecedented opportunities in the development of functional ceramics for various applications.
Assuntos
Cerâmica/química , Substâncias Macromoleculares/química , Nanoestruturas/química , Géis/química , Metais/química , Óxidos/química , Polímeros/química , Porosidade , Silício/químicaRESUMO
Two wide-bandgap (WBG) conjugated polymers (PBPD-p and PBPD-m) based on phenyl-substituted benzodithiophene (BDT) with the different substitution position of the alkyl side chain and benzodithiophene-4,8-dione (BDD) units are designed and synthesized to investigate the influence of alkyl substitution position on the photovoltaic performance of polymers in polymer solar cells (PSCs). The thermogravimetric analysis, absorption spectroscopy, molecular energy level, X-ray diffraction, charge transport and photovoltaic performance of the polymers are systematically studied. Compared with PBPD-p, PBPD-m exhibits a slight blue-shift but a deeper highest occupied molecular orbital (HOMO) energy level, a tighter alkyl chain packing and a higher hole mobility. The PBPD-m-based PSCs blended with acceptor IT-4F shows a higher power conversion efficiency (PCE) of 11.95% with a high open-circuit voltage (Voc ) of 0.88 V, a short-circuit current density (Jsc ) of 19.76 mA cm-2 and a fill factor (FF) of 68.7% when compared with the PCE of 6.97% with a Voc of 0.81 V, a Jsc of 15.97 mA cm-2 and an FF of 53.9% for PBPD-p. These results suggest that it is a feasible and effective strategy to optimize photovoltaic properties of WBG polymers by changing the substitution position of alkyl side chain in PSCs.
Assuntos
Energia Solar , Polímeros , Luz SolarRESUMO
BACKGROUND: Layering techniques for direct composite resin restorations might be complicated for inexperienced learners, as a number of materials and instruments are required at each step. The present study aimed to compare and assess the teaching effect of step-by-step and all-in-one teaching methods in layering techniques for direct composite resin restorations among undergraduate dental students. METHODS: A total of 68 junior dental students participated in this study, which was a prospective and single-blind trial. The students were randomly divided into a step-by-step group (experimental group, n = 34) and all-in-one group (control group, n = 34). The same teacher taught the two groups, ensuring a comparable teaching effect. The final score of each student was an average of scores by two experts who were blinded to the grouping. The scoring system was consisted by five parts. Each part was assigned scores of 3.0, 1.5, or 0. The total maximum score was 15 and minimum was 0. The total time taken by each group was also calculated. RESULTS: The values of the quality of tooth restorations evaluated by experts for step-by-step and all-in-one groups were 11.29 ± 2.13 from 15 and 9.00 ± 2.71 from 15 (t = 3.88, P < 0.001), respectively. In addition, the time spent by the experimental group was significantly lesser than that spent by the control group, which was 122.47 ± 2.82 and 137.18 ± 6.75 min, respectively (t = 11.72, p < 0.001). CONCLUSION: With regard to the layering techniques for direct composite resin restorations, the outcomes were better in the step-by-step group than in the all-in-one group.
Assuntos
Resinas Compostas , Estudantes de Odontologia , Humanos , Estudos Prospectivos , Faculdades de Odontologia , Método Simples-CegoRESUMO
Single denitrification using bacteria has been widely investigated, but few studies have focused on the simultaneous removal of nitrate, phosphorus. and tetracycline. Strain L2, an iron-reducing bacteria, was immobilized using chitosan/polyvinyl alcohol to simultaneously remove nitrate and phosphorus. The effects of carbon/nitrogen ratio (1:1, 1.5:1, and 2:1), initial Fe2+ concentration (0, 15, and 30 mg·L-1), and HRT (2, 4, and 6 h) were assessed in bioreactors and optimum conditions were established. Results showed that the nitrate and phosphorus removal efficiency reached 100.00% (2.697 mg·L-1·h-1) and 81.93% (1.533 mg·L-1·h-1) under the conditions of carbon/nitrogen of 2:1, Fe2+ concentration of 30 mg·L-1 and HRT of 6 h. The precipitation of bioreactor, which identified as FeOOH by XRD, had significant adsorption on tetracycline. The results of high-throughput sequencing indicated that strain L2 played a significant role in denitrification. This bioreactor provided effective method for the treatment of polluted water contaminated by nitrate, phosphorus, and tetracycline.
Assuntos
Reatores Biológicos/microbiologia , Quitosana/química , Desnitrificação , Nitratos/metabolismo , Fósforo/metabolismo , Álcool de Polivinil/química , Tetraciclina/metabolismo , Eliminação de Resíduos LíquidosRESUMO
BACKGROUND/AIMS: Traumatic dental injuries (TDIs) are considered to be a public dental health problem worldwide. The aim of the current study was to provide the worldwide tendency and perspectives in TDIs in the last two decades via bibliometric analysis. METHODS: ''Tooth injuries'' was searched as the Medical Subject Headings term within PubMed with the date range from 1999 to 2018. Two investigators perused information in the articles according to the inclusion and exclusion criteria. The articles were independently categorized according to the following aspects: (a) annual scholarly output; (b) leading countries or regions; (c) leading journals; (d) productive authors; (e) citations; (f) study design; (f) distribution of topics; and (g) the type of dentition and TDIs. VOSviewer 1.6.7 and Citespace 5.2 were used for analyzing and visualizing bibliometric networks. RESULTS: A total of 2627 articles about traumatic dental injuries were published and indexed in PubMed during the two decades, and the number of publications on traumatic dental injuries was rising in general. The research outputs were mainly concentrated in developed countries and affiliated hospitals of universities. Brazil was the most productive country. The journal Dental Traumatology had the most contributions to the scientific research of traumatic dental injuries. "Case report" was the most frequent type of article (36.50%), followed by cross-sectional studies (19.57%) and case-control studies (13.67%). Most studies focused on the treatment of TDIs (38.94%), especially for avulsion (21.01%), crown fracture (9.71%), and intrusion (5.25%). Permanent teeth (66%) were the dominant dentition. CONCLUSION: There is a lack of high-quality well-designed studies such as cohort studies. The number of publications on prevention and the primary dentition is disproportionate in relation to their significance.
Assuntos
Fraturas dos Dentes , Traumatismos Dentários/epidemiologia , Bibliometria , Brasil , Estudos Transversais , HumanosRESUMO
OBEJECTIVE: To investigate the role of a novel chemically defined medium (CDM) in the regulation of dental papilla cells (DPCs) functional phenotype in vitro and periodontal bone regeneration in vivo. METHODS: DPCs were isolated and cultured in conventional medium (CM) or CDM. The surface makers, and the proliferation, migration and osteogenic differentiation abilities of DPCs were evaluated. In vivo, the DPCs that mixed with collagen gel were implanted into the model rats in the defect of periodontal to repair the periodontal tissue. Regeneration of the tissues was examined by microcomputed tomography and histological observation. RESULTS: DPCs in the CM group and CDM group showed similar surface markers. Compared to the CM group, the CDM significantly enhanced the proliferation, colony-forming efficiency and migration of DPCs in vitro. In addition, real time PCR showed that the expression levels of osteogenesis-related genes, Runx2, Alp and Opn. were significantly enhanced in DPCs in the CDM group. DPCs cells treated with CDM also exhibited higher alkaline phosphatase activity and stronger ability of formation of mineralized nodules in vitro. In vivo, DPCs from CDM group significantly enhanced the periodontal bone regeneration and the reconstruction of periodontal bone tissues in rat periodontal defect model. CONCLUSION: CDM is a suitable medium to culture DPCs for periodontal bone regeneration. This research provided a substitute for basic research and set the stage for future clinical application of stem cell transplantation.
Assuntos
Osteogênese , Ligamento Periodontal , Animais , Regeneração Óssea , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Papila Dentária , Ratos , Regeneração , Microtomografia por Raio-XRESUMO
Nephronectin (NPNT) is a novel extracellular matrix protein and a new ligand of integrin α8ß1. Recent studies showed that NPNT is highly expressed in kidney, lung, thyroid, etc, and it may play an important role in many pathological conditions. NPNT is involved in the process of kidney development and acute kidney injury, regulates proliferation and differentiation of osteoblast, and induces the vasculogenesis in vitro. NPNT may play a key role in pathological osteoporosis and therefore be a new therapeutic target of bone diseases. NPNT gene variants are not only associated with lung function, but also potentially implicated in chronic airway diseases development. Moreover, NPNT is also an important factor that mediates pathology of cardiac, epidermis, breast, liver and teeth diseases. In this paper, we reviewed some research progresses on the structure, distribution, physiological and pathophysiological functions of NPNT.
Assuntos
Proteínas da Matriz Extracelular/fisiologia , Rim/fisiologia , Osteoblastos/citologia , Diferenciação Celular , Proliferação de Células , Humanos , OsteoporoseRESUMO
In this report, a series of polycations are designed and synthesized by conjugating reactive oxygen species (ROS)-responsive thioacetal-linkers to low molecular weight (LMW) polyethylenimine (PEI) via ring-opening polymerization. Their structureâ»activity relationships (SARs) as gene delivery vectors are systematically studied. Although the MWs of the target polymers are only ~9 KDa, they show good DNA binding ability. The formed polyplexes, which are stable toward serum but decomposed under ROS-conditions, have appropriate sizes (180~300 nm) and positive zeta-potentials (+35~50 mV). In vitro experiments reveal that these materials have low cytotoxicity, and higher transfection efficiency (TE) than controls. Furthermore, the title polymers exhibit excellent serum tolerance. With the present of 10% serum, the TE of the polymers even increases up to 10 times higher than 25 KDa PEI and 9 times higher than Lipofectamine 2000. The SAR studies also reveal that electron-withdrawing groups on the aromatic ring in 4a may benefit to balance between the DNA condensation and release for efficient gene transfection.
Assuntos
Técnicas de Transferência de Genes , Nanopartículas , Espécies Reativas de Oxigênio , Compostos de Sulfidrila , Linhagem Celular , Sobrevivência Celular , DNA/química , Vetores Genéticos/química , Humanos , Peso Molecular , Nanopartículas/química , Poliaminas/química , Polieletrólitos , Polímeros/síntese química , Polímeros/química , Espécies Reativas de Oxigênio/química , Compostos de Sulfidrila/químicaRESUMO
Background: We studied whether 48 weeks of pegylated interferon alfa-2b (peginterferon) add-on therapy increases serological response in hepatitis B virus (HBV) envelope antigen (HBeAg)-positive patients receiving nucleos(t)ide analogue (NA) therapy, compared with continued NA monotherapy. Methods: This randomized trial included HBeAg-positive patients with compensated liver disease who were treated with entecavir/tenofovir for >12 months and had an HBV DNA load of <2000 IU/mL. Patients were randomly assigned in a 1:1 ratio to 48 weeks of peginterferon add-on therapy (n = 39) or continued NA monotherapy (n = 38). Response (defined as HBeAg seroconversion with an HBV DNA load of <200 IU/mL) was assessed at week 48, with responders discontinuing NA therapy at week 72. Results: The primary end point (response at week 96) was achieved in 18% of patients who were assigned peginterferon add-on therapy versus 8% of patients assigned NA monotherapy (P = .31). Among 58 interferon-naive patients, add-on therapy led to a greater frequency of HBeAg seroconversion (30% vs 7%; P = .034) and response (26% vs 7%; P = .068) at week 96, compared with monotherapy. Among 8 responders at week 48 who discontinued NA therapy at week 72, 6 patients (75%) maintained a response until week 96 (4 of 6 [67%] in the add-on therapy group vs 2 of 2 [100%] in the monotherapy group; P = 1.00). Adverse events were mainly related to peginterferon. Conclusion: The primary end point was negative, but peginterferon add-on therapy appeared to result in a greater frequency of HBeAg seroconversion, compared with NA monotherapy, in interferon-naive patients receiving NA therapy. Clinical Trials Registration: NCT01532843.
Assuntos
Antivirais/administração & dosagem , Guanina/análogos & derivados , Hepatite B Crônica/tratamento farmacológico , Interferon-alfa/administração & dosagem , Polietilenoglicóis/administração & dosagem , Tenofovir/uso terapêutico , Adulto , China , DNA Viral/sangue , Quimioterapia Combinada , Feminino , Guanina/uso terapêutico , Antígenos E da Hepatite B/sangue , Vírus da Hepatite B , Humanos , Interferon alfa-2 , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Países Baixos , Proteínas Recombinantes/administração & dosagem , Resultado do TratamentoRESUMO
An atorvastatin calcium (AT)-loaded dextran sulfate (DXS)-coated core-shell reconstituted high density lipoprotein (rHDL), termed AT-DXS-LP-rHDL, was developed for targeted drug delivery to macrophages and suppression of inflammation via the high affinity of DXS with scavenge receptor class AI (SR-AI) as well as depletion of intracellular cholesterol by apolipoprotein A-I (apoA-I)-mediated cholesterol efflux. These core-shell nanoparticles comprising an AT-loaded negatively charged poly(lactide-co-glycolide) (PLGA) core and a cationic lipid bilayer shell were prepared by nanoprecipitation method followed by thin film hydration and extrusion. The nanoparticles were further functionalized with apoA-I and DXS via sodium cholate mediation and electrostatic interaction, respectively. The core-shell structure and the surface coating of apoA-I and DXS were verified by the increased particle size, inverted zeta potential, and reduced in vitro drug release rate. The TEM image further confirmed the entrapment of the PLGA nanoparticles in the aqueous interior of the liposomes. In vitro cell viability assay showed the biocompatibility of the AT-loaded nanocarriers. The cellular uptake study illustrated that the targeting efficacy to macrophages increased in the following order: PLGA nanoparticles (P-NP), core-shell nanoparticles (LP-NP), core-shell rHDL (LP-rHDL), and DXS-LP-rHDL. Moreover, cellular drug efficacy of AT-loaded nanoparticles in preventing macrophage-derived foam cell formation and inflammation such as intracellular lipid deposition, cholesterol esters content, DiI-oxLDL uptake, cholesterol efflux, and secretion of TNF-α, IL-6, and IL-10 was much better than that of the drug-free nanoparticles, consistent with the results of cellular uptake study. Collectively, AT-DXS-LP-rHDL, as multifunctional carriers, could not only deliver more drug to macrophages, but also present antiatherogenic actions of the biofunctional nanocarriers through damping oxidized low density lipoproteins (oxLDL) uptake and promoting cholesterol efflux.
Assuntos
Aterosclerose/tratamento farmacológico , Sulfato de Dextrana/química , Portadores de Fármacos/química , Lipoproteínas HDL/química , Macrófagos/metabolismo , Animais , Atorvastatina/química , Atorvastatina/farmacologia , Atorvastatina/uso terapêutico , Transporte Biológico , Colesterol/metabolismo , Portadores de Fármacos/metabolismo , Humanos , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Espaço Intracelular/metabolismo , Ácido Láctico/química , Lipoproteínas LDL/metabolismo , Camundongos , Modelos Moleculares , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Conformação Proteica , Células RAW 264.7 , Propriedades de Superfície , Fator de Necrose Tumoral alfa/metabolismoRESUMO
A ring-shaped electroeluter (RSE) was designed for protein recovery from polyacrylamide gel matrix. The RSE was designed in such a way that a ring-shaped well was used to place gel slices and an enrichment well was used to collect eluted protein samples. With HSA as model protein, the electroelution time was less than 30 min with 80% recovery rate, and the concentration of recovered protein was 50 times higher than that of conventional method. The RSE could be reused at least ten times. The developed device makes great advance towards economic electroelution of biomolecules (such as proteins) from gel matrix.
Assuntos
Resinas Acrílicas/química , Eletroquímica/instrumentação , Eletroforese em Gel de Poliacrilamida/métodos , Albumina Sérica/isolamento & purificação , HumanosRESUMO
Quaternized chitosan is a cationic biopolymer with good antibacterial activity, biocompatibility, and biodegradability, and it has been widely applied in many fields. We have developed a convenient method to evaluate the antibacterial activity of hydroxypropyltrimethylammonium chloride chitosan (HACC) with a nonionic surfactant poloxamer in aqueous solution by monitoring the change of the oxidation peak current in cyclic voltammetry. Increasing values of the oxidation peak current were positively correlated with the antibacterial activity of HACC-poloxamer solutions. Optical microscope images, the zeta potential, and fluorescence spectroscopy showed that the aggregation state of HACC-poloxamer was related to the ratio of the two polymers and also to the antibacterial activity and oxidation peak current. At an HACC-to-poloxamer ratio of 1:0.75, the maximum surface charge density and the smooth edge of HACC-poloxamer aggregates can accelerate diffusion in aqueous solution. It is expected that this convenient method can be applied for a quick evaluation of the antibacterial activity of cationic biopolymers in aqueous solution. Graphical Abstract The cyclic voltammograms of MB in HACC/poloxamer solution, and the antibacterial efficiency against S. aureus after incubated with HACC (a) and 1/0.75 of HACC/poloxamer (b).
Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Quitosana/análogos & derivados , Quitosana/farmacologia , Poloxâmero/química , Poloxâmero/farmacologia , Staphylococcus aureus/efeitos dos fármacos , Compostos de Amônio/química , Compostos de Amônio/farmacologia , Técnicas Eletroquímicas/métodos , Humanos , Testes de Sensibilidade Microbiana/métodos , Infecções Estafilocócicas/tratamento farmacológico , Tensoativos/química , Tensoativos/farmacologiaRESUMO
We report tandem polymer light emitting devices by using the PEDOTâ¶PSS/ZnO/PEIE charge generation layer (CGL) and investigate the influences of the conductance and thickness of PEDOTâ¶PSS layer on the properties of the devices. The results indicate that the conductance and thickness of PEDOTâ¶PSS layer have marginal impact on the J-V characteristics of the devices, while significant influences of device efficiency upon utilization of different PEDOTâ¶PSS specimens mainly come from their different strengths on exciton quenching. Luminance efficiency of TOLEDs with the PEDOTâ¶PSS thickness of 60 nm in CGL is better than TOLEDs with the PEDOTâ¶PSS thickness of 30 nm in CGL, the reason is that PEDOTâ¶PSS thickness of 60 nm the surface topography is more even . Luminance efficiency and driving voltage of the tandem devices match the sum of the luminance efficiency and driving voltage of the component light-emitting units, respectively, indicating that charges generated in the CGL can be injected efficiently into the adjacent light-emitting units. Incorporation of a V2O5 layer into the CGL structure only slightly affects the J-V and LE-I characteristics of the tandem devices, suggesting that the utilization of the PEDOTâ¶PSS/ZnO/PEIE CGL enables the simplification of the CGL structure without compromising device performance. The luminescence spectra of TOLEDs obviously involves two light emitting unit of spectrum, which shows that two light emitting unit in TOLEDs is normal work. Measurements on the capacitance-voltage characteristics of the CGL-based devices confirm that under negative bias (ITO anode) charges are accumulated and displaced in the CGL, which is totally in line with the full operation of light emitting units in the tandem devices. PEDOTâ¶PSS/ZnO/PEIE layer is evidenced the effective CGL. On this basis, for the first time we report tandem polymer light emitting devices containing three SY-PPV light-emitting unitsï¼which show the mixture of luminance efficiency and external quantum efficiency of 21.7 cd·A-1 and 6.95%, similar to the total luminance efficiency and external quantum efficiency of constituent LEUs. At 5 000 cd·m-2, the luminance efficiency and external quantum efficiency of the tandem devices are 20.5 cd·A-1 and 6.6%. Thus, the increase in the number of light emitting units leads to almost no performance losses, implying the robustness of the PEDOTâ¶PSS/ZnO/PEIE CGL. Tandem polymer light emitting devices containing three SY-PPV light-emitting units of the luminescent spectra is close to the light emitting unit. Further efforts on the optimization of hole injection layer in the CGL to minimize exciton quenching are underlying to promote the luminance efficiency of tandem polymer light emitting devices.
Assuntos
Luminescência , Polímeros , EletrodosRESUMO
BACKGROUND: Bacteria affect oral health, but few studies have systematically examined the role of bacterial communities in oral diseases. We examined this relationship in a large population-based Chinese cancer screening cohort. METHODS: Human Oral Microbe Identification Microarrays were used to test for the presence of 272 human oral bacterial species (97 genera) in upper digestive tract (UDT) samples collected from 659 participants. Oral health was assessed using US NHANES (National Health and Nutrition Examination Survey) protocols. We assessed both dental health (total teeth missing; tooth decay; and the decayed, missing, and filled teeth (DMFT) score) and periodontal health (bleeding on probing (BoP) extent score, loss of attachment extent score, and a periodontitis summary estimate). RESULTS: Microbial richness, estimated by number of genera per sample, was positively correlated with BoP score (P = 0.015), but negatively correlated with tooth decay and DMFT score (P = 0.008 and 0.022 respectively). Regarding ß-diversity, as estimated by the UniFrac distance matrix for pairwise differences among samples, at least one of the first three principal components of the UniFrac distance matrix was correlated with the number of missing teeth, tooth decay, DMFT, BoP, or periodontitis. Of the examined genera, Parvimonas was positively associated with BoP and periodontitis. Veillonellacease [G-1] was associated with a high DMFT score, and Filifactor and Peptostreptococcus were associated with a low DMFT score. CONCLUSIONS: Our results suggest distinct relationships between UDT microbiota and dental and periodontal health. Poor dental health was associated with a less microbial diversity, whereas poor periodontal health was associated with more diversity and the presence of potentially pathogenic species.
Assuntos
Periodontite Crônica/epidemiologia , Saúde Bucal , Adulto , Idoso , China/epidemiologia , Periodontite Crônica/microbiologia , Periodontite Crônica/patologia , Feminino , Trato Gastrointestinal/microbiologia , Bactérias Gram-Negativas/isolamento & purificação , Bactérias Gram-Positivas/isolamento & purificação , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Índice de Gravidade de Doença , Fatores SocioeconômicosRESUMO
In order to test the equilibrium solubility of puerarin in different solvents and solubilizer,cilia toxicity and irritation of these excipient, the balance method, toad in the ciliary body toxicity and rat nasal mucosa irritation were used respectively. Results showed that puerarin solubility was 56.44 g x L(-1) in combined solvent of 30% PEG200 and 10% Kolliphor HS 15. With normal saline solution as negative control and sodium deoxycholate as positive control, the effects of 30% PEG200, 30% PEG 400, 10% Kolliphor HS 15 and combination of 30% of PEG200 and 10% Kolliphor HS 15 on toad palate cilium were observed and cilia movement duration was recorded. The results indicated that there was no significant difference in cilia movement duration among 30% PEG200, 10% Kolliphor HS 15 and normal saline group. The rats long-term nasal mucous membrane irritation of 30% PEG 400, 10% Kolliphor HS 15, which had no cilia toxicity, was studied, with normal saline solution as negative control. There were no significant difference revealed on rat nasal mucosa epithelial thickness among 30% PEG 400, 10% Kolliphor HS 15 and normal saline. Above researches showed 30% PEG 400, 10% Kolliphor HS 15 was ideal for solubility of puerarin nasal drops and showed a lower cilia toxicity and irritation, and can be used as the solvent and solubilizer of puerarin nasal drops.