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

Banco de datos
País/Región como asunto
Tipo del documento
Intervalo de año de publicación
1.
Macromol Rapid Commun ; 45(4): e2300566, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37931779

RESUMEN

Donor-acceptor (D-A) conjugated polymer (CP) featuring high charge mobility and widely tunable energy bands have shown promising prospects in photocatalysis. In this work, a library of ternary D-A CPs (22 polymers) based on benzothiadiazole, bithiophene, and fluorene derivatives (i.e., fluorene [Fl], 9,9-dihexylfluorene [HF], and 9,9'-spirobifluorene [SF]) with and without alkyl side chains, and with 3D geometry are designed and synthesized via atom-economical direct C-H arylation polymerization to explore the synergetic effects of stereochemistry, D/A ratio, and alkyl chains on the properties and photocatalytic performances, which reveal that 1) the cross-shaped 3D spirobifluorene (SF) building block shows the highest hydrogen evolution rates (HER) owing to the sufficient photocatalytic active sites exposed, 2) the alkyl-free linear polymer (FlBtBT0.05 ) exhibit the highest photocatalytic pollutant degradation performance owing to its superior charge separation, and 3) the alkyl side chains are redundances that will exert detrimental effects on the aqueous photocatalysis owing to their insulating and hydrophobic property. The structure-property-performance correlation results obtained will provide a desirable guideline for the rational design of CP-based photocatalysts.


Asunto(s)
Contaminantes Ambientales , Fluorenos , Hidrógeno , Polimerizacion , Polímeros
2.
Int J Mol Sci ; 24(7)2023 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-37047424

RESUMEN

At present, the development and usage of degradable plastics instead of traditional plastics is an effective way to solve the pollution of marine microplastics. Poly (butylene adipate-co-terephthalate) (PBAT) is known as one of the most promising biodegradable materials. Nevertheless, the degradation rate of PBAT in water environment is slow. In this work, we successfully prepared four kinds of high molecular weight polyester copolyesters (PBATGA) via quaternary copolymerization. The results showed that the intrinsic viscosity of PBATGA copolymers ranged from 0.74 to 1.01 dL/g with a glycolic acid content of 0-40%. PBATGA copolymers had excellent flexibility and thermal stability. The tensile strength was 5~40 MPa, the elongation at break was greater than 460%, especially the elongation at break of PBATGA10 at 1235%, and the thermal decomposition temperature of PBATGA copolyesters was higher than 375 °C. It was found that PBATGA copolyester had a faster hydrolysis rate than PBAT, and the weight loss of PBATGA copolymers showed a tendency of pH = 12 > Lipase ≈ pH = 7 > pH = 2. The quaternary polymerization of PBAT will have the advantage of achieving industrialization, unlike the previous polymerization process. In addition, the polymerization of PBATGA copolyesters not only utilizes the by-products of the coal chemical industry, but also it can be promising in the production of biodegradable packaging to reduce marine plastic pollution.


Asunto(s)
Plásticos , Poliésteres , Polimerizacion , Poliésteres/química , Polímeros , Adipatos
3.
J Am Chem Soc ; 144(34): 15689-15697, 2022 08 31.
Artículo en Inglés | MEDLINE | ID: mdl-35930760

RESUMEN

Stacking interactions are of significant importance in the fields of chemistry, biology, and material optoelectronics because they determine the efficiency of charge transfer between molecules and their quantum states. Previous studies have proven that when two monomers are π-stacked in series to form a dimer, the electrical conductance of the dimer is significantly lower than that of the monomer. Here, we present a strong opposite case that when two anthanthrene monomers are π-stacked to form a dimer in a scanning tunneling microscopic break junction, the conductance increases by as much as 25 in comparison with a monomer, which originates from a room-temperature quantum interference. Remarkably, both theory and experiment consistently reveal that this effect can be reversed by changing the connectivity of external electrodes to the monomer core. These results demonstrate that synthetic control of connectivity to molecular cores can be combined with stacking interactions between their π systems to modify and optimize charge transfer between molecules, opening up a wide variety of potential applications ranging from organic optoelectronics and photovoltaics to nanoelectronics and single-molecule electronics.


Asunto(s)
Grafito , Conductividad Eléctrica , Electrodos , Electrónica , Microscopía de Túnel de Rastreo , Polímeros
4.
Int J Mol Sci ; 23(19)2022 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-36232379

RESUMEN

The main problem of manufacturing with traditional biodegradable plastics is that it is more expensive than manufacturing with polymers derived from petroleum, and the application scope is currently limited due to poor comprehensive performance. In this study, a novel biodegradable poly(butylene adipic acid/terephthalate-co-glycolic acid) (PBATGA) copolyester with 25-60% glycolic acid units was successfully synthesized by esterification and polycondensation using cheap coal chemical byproduct methyl glycolate instead of expensive glycolic acid. The structure of the copolyester was characterized by ATR-FTIR, 1H NMR, DSC, and XRD; and its barrier property, water contact angle, heat resistance, and mechanical properties were tested. According to the experiment result, the PBATGA copolyesters showed improved oxygen (O2) and water vapor barrier character, and better hydrophilicity when compared with PBAT. The crystallization peaks of PBATGAs were elevated from 64 °C to 77 °C when the content of the GA unit was 25 mol %, meanwhile, the elongation at the break of PBATGA25 was more than 1300%. These results indicate that PBATGA copolyesters have good potentiality in high O2 and water vapor barrier and degradable packaging material.


Asunto(s)
Plásticos Biodegradables , Petróleo , Adipatos , Alquenos , Carbón Mineral , Glicolatos , Oxígeno , Ácidos Ftálicos , Poliésteres/química , Polímeros/química , Vapor
5.
Environ Sci Technol ; 54(17): 10926-10935, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32693582

RESUMEN

Fertilizer drawn forward osmosis (FDFO) was proposed to extract fresh water from flowback and produced water (FPW) from shale gas extraction for irrigation, with fertilizer types and membrane orientations assessed. The draw solution (DS) with NH4H2PO4 displayed the best performance, while the DS with (NH4)2HPO4 resulted in the most severe membrane fouling. The DS with KCl and KNO3 led to substantial reverse solute fluxes. The FDFO operation where the active layer of the membrane was facing the feed solution outperformed that when the active layer was facing the DS. The diluted DS and diluted FPW samples were used for irrigation of Cherry radish and Chinese cabbage. Compared to deionized water, irrigation with the diluted DS (total dissolved solid (TDS) = 350 mg·L-1) promoted plant growth. In contrast, inhibited plant growth was observed when FPW with high salinity (TDS = 5000 mg·L-1) and low salinity (TDS = 1000 mg·L-1) was used for irrigation of long-term (8-week) plant cultures. Finally, upregulated genes were identified to illustrate the difference in plant growth. The results of this study provide a guide for efficient and safe use of FPW after FDFO treatment for agricultural application.


Asunto(s)
Fertilizantes , Purificación del Agua , Fertilizantes/análisis , Membranas Artificiales , Gas Natural , Ósmosis , Agua
6.
Eur Arch Otorhinolaryngol ; 276(10): 2819-2826, 2019 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-31332548

RESUMEN

BACKGROUND: The discomfort and complications have always been problems for nasal packing materials. This study provided a new nasal packing material called high expansion degradable cotton (HEDC). METHODS: Nasal endoscopic surgery was used to establish a dog model of nasal bleeding, and wound surfaces were filled with Merocel, Nasopore and HEDC, respectively. Intraoperative and postoperative bleeding of 24 h was calculated. We evaluate the absorbability score, adhesion score, infection sore and nasal mucosal epithelium in postoperative 3, 7, 14 and 28 days. HE staining and electron microscopy were used to evaluate the recovery of nasal mucosa. RESULTS: There was no significant difference in nasal bleeding between HEDC, Merocel and Nasopore. Nasal endoscopic examination revealed HEDC absorbability of score, adhesion score, infection score were significantly lower than Merocel and Nasopore. The epithelialization time of HEDC was significantly shorter than that of Merocel and Nasopore. HE staining showed that HEDC and Nasopore could significantly reduce scar hyperplasia on the wound surface. The results of electron microscopy suggested that HEDC could protect the edge cilia of the wound. CONCLUSION: HEDC could be used as new choice for hemostasis after nasal endoscopic surgery, which could reduce nasal epithelialization time, and protect wound edge cilia.


Asunto(s)
Epistaxis/terapia , Formaldehído/administración & dosificación , Procedimientos Quírurgicos Nasales/efectos adversos , Cirugía Endoscópica por Orificios Naturales/efectos adversos , Alcohol Polivinílico/administración & dosificación , Hemorragia Posoperatoria/terapia , Animales , Perros , Técnicas Hemostáticas , Hemostáticos/administración & dosificación , Humanos , Modelos Animales , Procedimientos Quírurgicos Nasales/métodos , Cirugía Endoscópica por Orificios Naturales/métodos , Adherencias Tisulares , Resultado del Tratamiento
7.
Molecules ; 24(9)2019 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-31067638

RESUMEN

Diketopyrrolopyrrole (DPP) is an important type of π-conjugated building block for high-performance organic electronic materials. DPP-based conjugated materials are usually synthesized via Suzuki, Stille, or Negishi cross-coupling reactions, which require organometallic precursors. In this paper, a series of novel phenyl-cored DPP molecules, including five meta-phenyl-cored molecules and four para-phenyl-cored molecules, have been synthesized in moderate to good yields, in a facile manner, through the Pd-catalyzed direct arylation of C-H bonds, and their optoelectrical properties have been investigated in detail. All new molecules have been fully characterized by NMR, MALDI-TOF MS, elemental analysis, UV-visible spectroscopy, and cyclic voltammetry. This synthetic strategy has evident advantages of atom- and step-economy and low cost, compared with traditional cross-coupling reactions.


Asunto(s)
Estructura Molecular , Polímeros/síntesis química , Pirroles/síntesis química , Catálisis , Electrónica , Polímeros/química , Pirroles/química
8.
BMC Plant Biol ; 18(1): 50, 2018 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-29580214

RESUMEN

BACKGROUND: Silicon (Si) can confer plant resistance to both abiotic and biotic stress. In the present study, the priming effect of Si on rice (Oryza sativa cv Nipponbare) against the root-knot nematode Meloidogyne graminicola and its histochemical and molecular impact on plant defense mechanisms were evaluated. RESULTS: Si amendment significantly reduced nematodes in rice roots and delayed their development, while no obvious negative effect on giant cells was observed. Increased resistance in rice was correlated with higher transcript levels of defense-related genes (OsERF1, OsEIN2 and OsACS1) in the ethylene (ET) pathway. Si amendment significantly reduced nematode numbers in rice plants with enhanced ET signaling but had no effect in plants deficient in ET signaling, indicating that the priming effects of Si were dependent on the ET pathway. A higher deposition of callose and accumulation of phenolic compounds were observed in rice roots after nematode attack in Si-amended plants than in the controls. CONCLUSION: These findings indicate that the priming effect may partially depend on the production of phenolic compounds and hydrogen peroxide. Further research is required to model the ethylene signal transduction pathway that occurs in the Si-plant-nematode interaction system and gain a better understanding of Si-induced defense in rice.


Asunto(s)
Oryza/efectos de los fármacos , Oryza/parasitología , Enfermedades de las Plantas/prevención & control , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/parasitología , Silicio/farmacología , Tylenchoidea/patogenicidad , Animales , Lignina/metabolismo , Enfermedades de las Plantas/parasitología , Tylenchoidea/efectos de los fármacos
9.
Bioconjug Chem ; 29(8): 2619-2627, 2018 08 15.
Artículo en Inglés | MEDLINE | ID: mdl-29923709

RESUMEN

Design and synthesis of biocompatible and multifunctional photothermal agents is crucial for effective cancer phototherapy. In order to achieve this ambition, simple D-A-D structural bisbithiophenyl diketopyrrolopyrrole (TDPP) was fabricated. In this molecule, the donor, 2-thiophenylboric acid, was conjugated via Suzuki coupling reaction, which could expand the emission wavelength to the red region of the spectrum. TDPP could self-assemble into stable and uniform nanoparticles (TDPP NPs) in assistant of amphiphilic Pluronic F-127 polymer. Exposing TDPP NPs (100 µg/mL) aqueous dispersion to 638 nm (0.61 W/cm2) laser irradiation resulted in a temperature elevation of approximately 30 °C within 5 min, which is high enough for inducing the cytotoxicity and tumor inhibition. Because of the bathochromic shift absorption of TDPP NPs in water, TDPP NPs could also act as a contrast agent for near-infrared fluorescence imaging (NIRF) to visualize the drug distribution in vivo. Coupled with the infrared thermal imaging properties of the photothermal agent, TDPP NPs were proven to be a multifunctional theranostic agent for dual-modal imaging-guided phototherapy.


Asunto(s)
Imagen Óptica/métodos , Fototerapia/métodos , Pirroles/química , Ácidos Bóricos/química , Supervivencia Celular , Células HeLa , Humanos , Estructura Molecular , Nanopartículas/química , Poloxámero/química , Nanomedicina Teranóstica/métodos
10.
J Nanosci Nanotechnol ; 18(4): 2330-2336, 2018 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-29442900

RESUMEN

In the following study, we describe the preparation and characterization of poly(ethylene glycol) (PEG) and biotin modified, doxorubicin (DOX) loaded silica nanoparticles (Dox/SLN-PEG-Biotin), which was employed as a drug delivery system for colon cancer therapy. The DOX/SLN-PEG-Biotin exhibited small particle size and low cytotoxicity in vitro. Moreover, the Dox releases from DOX/SLN-PEG-Biotin followed a redox-sensitive behavior. Biotin functionalized Dox/SLN-PEG-Biotin demonstrated tumor-targeted delivery of their payload, resulting in enhanced cellular uptake in HCT116 tumor cells and potentiated tumor accumulation in HCT116 tumor-bearing mice. In particular, in vivo anti-cancer assay confirmed that DOX/SLN-PEG-Biotin as a tumor-targeted delivery system exerted strong anti-cancer efficacy. Altogether, DOX chemotherapy using DOX/SLN-PEG-Biotin might be an effective strategy for improved treatment in colon cancer.


Asunto(s)
Antibióticos Antineoplásicos/administración & dosificación , Neoplasias del Colon/tratamiento farmacológico , Doxorrubicina/administración & dosificación , Portadores de Fármacos , Nanopartículas , Animales , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos , Ratones , Polietilenglicoles , Dióxido de Silicio/química
11.
Bioconjug Chem ; 28(11): 2784-2793, 2017 11 15.
Artículo en Inglés | MEDLINE | ID: mdl-28972780

RESUMEN

As a noninvasive treatment method, photothermal therapy (PTT) has been widely investigated for cancer therapy. In this work, metal-organic frameworks@polymer composites (UiO-66@CyP) with bioimaging and PTT activity were prepared by introducing cyanine-containing polymer (CyP) via multicomponent Passerini reaction in the presence of Zr-based nanoscale metal-organic frameworks (UiO-66). As-prepared UiO-66@CyP not only possesses uniformed size, controllable morphology, and excellent dispersibility in aqueous media, but also indicates strong near-infrared absorption and high photothermal conversion efficiency. Due to these combined merits, UiO-66@CyP appears to be an excellent phototherapy agent for ablation of tumor cells under a low-power laser irradiation and near-infrared fluorescence imaging agent. This work might open up a new avenue to develop multifunctional composites by integrating metal-organic frameworks with carboxyl, aldehyde, and isocyano-containing materials.


Asunto(s)
Carbocianinas/química , Neoplasias/diagnóstico por imagen , Neoplasias/terapia , Imagen Óptica/métodos , Compuestos Organometálicos/química , Polímeros/química , Animales , Carbocianinas/uso terapéutico , Línea Celular Tumoral , Células HeLa , Humanos , Hipertermia Inducida/métodos , Masculino , Ratones Endogámicos BALB C , Compuestos Organometálicos/uso terapéutico , Fototerapia/métodos , Polímeros/uso terapéutico
12.
Inorg Chem ; 56(21): 12952-12966, 2017 Nov 06.
Artículo en Inglés | MEDLINE | ID: mdl-29019398

RESUMEN

We investigated the coordination ability of the bis(1,2,4-triazolyl) module, tr2pr = 1,3-bis(1,2,4-triazol-4-yl)propane, toward the engineering of solid-state structures of copper polyoxomolybdates utilizing a composition space diagram approach. Different binding modes of the ligand including [N-N]-bridging and N-terminal coordination and the existence of favorable conformation forms (anti/anti, gauche/anti, and gauche/gauche) resulted in varieties of mixed metal CuI/MoVI and CuII/MoVI coordination polymers prepared under hydrothermal conditions. The composition space analysis employed was aimed at both the development of new coordination solids and their crystallization fields through systematic changes of the reagent ratios [copper(II) and molybdenum(VI) oxide precursors and the tr2pr ligand]. Nine coordination compounds were synthesized and structurally characterized. The diverse coordination architectures of the compounds are composed of cationic fragments such as [CuII3(µ2-OH)2(µ2-tr)2]4+, [CuII3(µ2-tr)6]6+, [CuII2(µ2-tr)3]4+, etc., connected to polymeric arrays by anionic species (molybdate MoO42-, isomeric α-, δ-, and ß-octamolybdates {Mo8O26}4- or {Mo8O28H2}6-). The inorganic copper(I,II)/molybdenum(VI) oxide matrix itself forms discrete or low-dimensional subtopological motifs (0D, 1D, or 2D), while the organic spacers interconnect them into higher-dimensional networks. The 3D coordination hybrids show moderate thermal stability up to 230-250 °C, while for the 2D compounds, the stability of the framework is distinctly lower (∼190 °C). The magnetic properties of the most representative samples were investigated. The magnetic interactions were rationalized in terms of analyzing the planes of the magnetic orbitals.


Asunto(s)
Complejos de Coordinación/química , Cobre/química , Molibdeno/química , Polímeros/química , Triazoles/química , Complejos de Coordinación/síntesis química , Ligandos , Fenómenos Magnéticos , Modelos Químicos , Conformación Molecular , Estructura Molecular , Polímeros/síntesis química
13.
J Appl Clin Med Phys ; 18(1): 128-138, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28291913

RESUMEN

MOTIVATION: In this study, a method is reported to perform IMRT and VMAT treatment delivery verification using 3D volumetric primary beam fluences reconstructed directly from planned beam parameters and treatment delivery records. The goals of this paper are to demonstrate that 1) 3D beam fluences can be reconstructed efficiently, 2) quality assurance (QA) based on the reconstructed 3D fluences is capable of detecting additional treatment delivery errors, particularly for VMAT plans, beyond those identifiable by other existing treatment delivery verification methods, and 3) QA results based on 3D fluence calculation (3DFC) are correlated with QA results based on physical phantom measurements and radiation dose recalculations. METHODS: Using beam parameters extracted from DICOM plan files and treatment delivery log files, 3D volumetric primary fluences are reconstructed by forward-projecting the beam apertures, defined by the MLC leaf positions and modulated by beam MU values, at all gantry angles using first-order ray tracing. Treatment delivery verifications are performed by comparing 3D fluences reconstructed using beam parameters in delivery log files against those reconstructed from treatment plans. Passing rates are then determined using both voxel intensity differences and a 3D gamma analysis. QA sensitivity to various sources of errors is defined as the observed differences in passing rates. Correlations between passing rates obtained from QA derived from both 3D fluence calculations and physical measurements are investigated prospectively using 20 clinical treatment plans with artificially introduced machine delivery errors. RESULTS: Studies with artificially introduced errors show that common treatment delivery problems including gantry angle errors, MU errors, jaw position errors, collimator rotation errors, and MLC leaf position errors were detectable at less than normal machine tolerances. The reported 3DFC QA method has greater sensitivity than measurement-based QA methods. Statistical analysis-based Spearman's correlations shows that the 3DFC QA passing rates are significantly correlated with passing rates of physical phantom measurement-based QA methods. CONCLUSION: Among measurement-less treatment delivery verification methods, the reported 3DFC method is less demanding than those based on full dose re-calculations, and more comprehensive than those that solely checks beam parameters in treatment log files. With QA passing rates correlating to measurement-based passing rates, the 3DFC QA results could be useful for complementing the physical phantom measurements, or verifying treatment deliveries when physical measurements are not available. For the past 4+ years, the reported method has been implemented at authors' institution 1) as a complementary metric to physical phantom measurements for pretreatment, patient-specific QA of IMRT and VMAT plans, and 2) as an important part of the log file-based automated verification of daily patient treatment deliveries. It has been demonstrated to be useful in catching both treatment plan data transfer errors and treatment delivery problems.


Asunto(s)
Procesamiento de Imagen Asistido por Computador/métodos , Neoplasias Pulmonares/radioterapia , Fantasmas de Imagen , Garantía de la Calidad de Atención de Salud/normas , Planificación de la Radioterapia Asistida por Computador/métodos , Radioterapia de Intensidad Modulada/métodos , Programas Informáticos , Humanos , Método de Montecarlo , Aceleradores de Partículas , Control de Calidad , Dosificación Radioterapéutica
14.
Biomed Environ Sci ; 30(10): 701-707, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29122090

RESUMEN

OBJECTIVE: To analyze the prevalence and years lived with disability (YLD) from dental caries among children and adolescents and the time trends over the past two decades in Sichuan province, the largest province in west China. METHODS: Based on the Global Burden of Disease Study 2015 (GBD2015), which systematically assessed the epidemiological characteristics of major diseases and their transitions by country and region from 1990 to 2015, we extracted the estimated results for China. We then used the Bayesian meta-regression method to estimate the sex- and age-specific prevalences and YLDs from dental caries among children and adolescents under 15 years old in Sichuan province and compared them with global and national indicators for the same period. RESULTS: In 2015, there were almost 6 million cases of dental caries in children and adolescents (aged < 15 years) in Sichuan province, accounting for 6% of the total cases in China. For children under 5 years, the prevalence of deciduous caries was 55.9%, and the YLDs value was 10.8 per 100,000, while it was 24.3% and 5.1 per 100,000 respectively among 5- to 14-year-olds; for those aged 5 to 14 years, the prevalence of permanent caries was 21.5%, and the YLDs value was 11.5 per 100,000. From 1990 to 2015, the prevalence of dental caries for children under 5 years increased substantially, by 16.2%, and the YLDs increased by 8.7%. Among those aged 5 to 14 years, the prevalence increased and the YLDs decreased. CONCLUSION: Dental caries remains a huge health burden in Western China. In contrast to the global and national data, the trend has increased rapidly over the past 25 years in this region. This work provides suggestions for the prevention and control for oral health in China with the policy of two-child.


Asunto(s)
Caries Dental/epidemiología , Caries Dental/patología , Adolescente , Niño , Preescolar , China/epidemiología , Personas con Discapacidad , Femenino , Humanos , Masculino , Prevalencia
15.
J Surg Res ; 200(2): 533-43, 2016 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-26602038

RESUMEN

BACKGROUND: A rodent occlusal hypofunction model has been widely established in jawbone-related studies. However, the effects of occlusal stimuli, with total elimination of molar contacts, and its rehabilitation on mandibular remodeling remain unclear. MATERIALS AND METHODS: Forty-eight 5-wk-old Sprague-Dawley male rats were used. Twenty-four experimental rats underwent occlusal hypofunction by insertion of a bite-raising appliance. Twenty-four rats received no treatment (control group). Two weeks later, half the experimental rats (occlusal hypofunction group) were killed; the appliance was removed from the remaining experimental rats (recovery group) for two additional weeks before killing. Control animals were killed biweekly. Body weight and masseter muscle weight were measured, and the mandibles were subjected to micro-computed tomography to evaluate the mandibular morphology and cortical bone characteristics. The expressions of osteoblast- and osteoclast-related genes were evaluated with quantitative polymerase chain reaction. RESULTS: No significant body weight differences were observed between the experimental and control rats. However, lighter masseter muscle, shorter mandibular incisor crown, mandibular body and ramus, and higher mandibular alveolar process and first molar fossae were observed in the occlusal hypofunction group. Moreover, the cortical bone characteristics associated with the expression of osteoblast- and osteoclast-related genes were remarkably different in the central and posterior mandible in the occlusal hypofunction group. At the 2-wk recovery time point after occlusal stimuli, the altered parameters in the masseter and mandible returned to normal levels. CONCLUSIONS: Mandibular remodeling via bone turnover is region specific for altered occlusal stimuli. Normal occlusion is an important determinant of the mandibular morphology and architecture.


Asunto(s)
Maloclusión/patología , Mandíbula/patología , Animales , Biomarcadores/metabolismo , Peso Corporal , Densidad Ósea/fisiología , Masculino , Maloclusión/diagnóstico por imagen , Maloclusión/rehabilitación , Mandíbula/diagnóstico por imagen , Mandíbula/metabolismo , Músculo Masetero/patología , Ratas , Ratas Sprague-Dawley , Microtomografía por Rayos X
16.
Nanomedicine ; 11(5): 1047-56, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25804412

RESUMEN

Local tumor recurrence remains a major clinical problem following surgical treatment for most cancers such as hepatocellular carcinoma (HCC). An implantable local drug delivery system may be suitable for addressing this unmet clinical need. In this study, asymmetric multilayer polylactide nanofiber (AMPN) mats were prepared and a one-sided and prolonged release profile of hydrophilic dye or oxaliplatin was observed after they were sandwiched between two liver lobes in mice. Covering the surgery site by drug-loaded AMPN mat after tumor resection, in both subcutaneous and orthotopic HCC model in mice, the recurrence of HCC was significantly retarded and the survival time of mice was markedly prolonged. In conclusion, post-surgical therapy at tumor resection margins by drug-loaded AMPN mats may represent a suitable application of nanofiber-based local chemotherapy. FROM THE CLINICAL EDITOR: After cancer surgery, local recurrence remains a significant problem. In this study, the authors designed asymmetric multilayer PLA nanofiber (AMPN) mats and loaded them with anti-tumor drugs. Both in-vitro and in-vivo experiments showed good efficacy in preventing tumor recurrence. This novel product may point a way to the future and improve survival of cancer patients.


Asunto(s)
Antineoplásicos/administración & dosificación , Carcinoma Hepatocelular/prevención & control , Preparaciones de Acción Retardada/química , Neoplasias Hepáticas/prevención & control , Nanofibras/química , Recurrencia Local de Neoplasia/prevención & control , Poliésteres/química , Animales , Antineoplásicos/uso terapéutico , Carcinoma Hepatocelular/patología , Carcinoma Hepatocelular/cirugía , Sistemas de Liberación de Medicamentos , Hígado/efectos de los fármacos , Hígado/patología , Hígado/cirugía , Neoplasias Hepáticas/patología , Neoplasias Hepáticas/cirugía , Masculino , Ratones , Nanofibras/ultraestructura , Recurrencia Local de Neoplasia/patología
17.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 46(4): 568-72, 2015 Jul.
Artículo en Zh | MEDLINE | ID: mdl-26480660

RESUMEN

OBJECTIVE: To study microbial diversity of peri-implantitis subgingival with high-throughput sequencing, and investigate microbiological etiology of peri-implantitis. METHODS: Subgingival plaques were sampled from the patients with peri-implantitis (D group) and non-peri-implantitis subjects (N group). The microbiological diversity of the subgingival plaques was detected by sequencing V4 region of 16S rRNA with Illumina Miseq platform. The diversity of the community structure was analyzed using Mothur software. RESULTS: A total of 156 507 gene sequences were detected in nine samples and 4 402 operational taxonomic units (OTUs) were found. Selenomonas, Pseudomonas, and Fusobacterium were dominant bacteria in D group, while Fusobacterium, Veillonella and Streptococcus were dominant bacteria in N group. Differences between peri-implantitis and non-peri-implantitis bacterial communities were observed at all phylogenetic levels by LEfSe, which was also found in PcoA test. CONCLUSION: The occurrence of peri-implantitis is not only related to periodontitis pathogenic microbe, but also related with the changes of oral microbial community structure. Treponema, Herbaspirillum, Butyricimonas and Phaeobacte may be closely related to the occurrence and development of peri-implantitis.


Asunto(s)
Bacterias/clasificación , Placa Dental/microbiología , Periimplantitis/microbiología , ADN Bacteriano/genética , Fusobacterium , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Periodontitis , Filogenia , Pseudomonas , ARN Ribosómico 16S/genética , Selenomonas , Análisis de Secuencia de ADN , Streptococcus , Treponema
18.
Int J Biol Macromol ; 255: 128185, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-37977456

RESUMEN

Chitosan and cellulose nanofiber films are frequently employed as biodegradable materials for food packaging. However, many exhibit suboptimal hydrophobicity and antioxidant properties. To address these shortcomings, we enhanced the performance by adding different concentrations of soybean protein isolate (SPI) to chitosan-cellulose nanofiber (CS-CNF) films. As SPI concentration varied, the turbidity, particle size, and ζ-potential of the film-forming solutions initially decreased and subsequently increased. This suggests that 1 % SPI augments the electrostatic attraction and compatibility. Rheological analysis confirmed a pronounced apparent viscosity at this concentration. Analyses using Fourier transform infrared spectra, Raman spectra, X-ray diffraction, and Scanning electron microscope revealed the presence of hydrogen bonds and electrostatic interactions between SPI and CS-CNF, indicative of superior compatibility. When SPI concentration was set at 1 %, notable enhancements in film attributes were observed: improvements in tensile strength and elongation at break, a reduction in water vapor permeability by 8.23 %, and an elevation in the contact angle by 18.85 %. Furthermore, at this concentration, the ABTS+ and DPPH scavenging capacities of the film surged by 61.53 % and 46.18 %, respectively. Meanwhile, the films we prepare are not toxic. This research offers valuable insights for the advancement and application of protein-polysaccharide-based films.


Asunto(s)
Quitosano , Películas Comestibles , Nanofibras , Quitosano/química , Proteínas de Soja/química , Celulosa , Nanofibras/química , Resistencia a la Tracción , Permeabilidad , Embalaje de Alimentos
19.
Int J Biol Macromol ; 269(Pt 1): 131900, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38677675

RESUMEN

Liposomes were modified with different proportions of ß-conglycinin (7S) and glycinin (11S) to form Lip-7S and Lip-11S. The morphology, interaction and in vitro simulated digestion of liposomes were studied. The particle size of Lip-7S was smaller than that of Lip-11S. When the values of Lip-7S and Lip-11S were 1:1 and 1:0.75, respectively, the ζ-potential had the maximum absolute value and the dispersion of the system was good. The results of multispectral analysis showed that hydrogen-bond and hydrophobic interaction dominated protein-modified liposomes, the protein structure adsorbed on the surface of liposomes changed, the content of α-helix decreased, and the structure of protein-modified liposomes became denser. The surface hydrophobicity and micropolarity of liposomes decreased with the increase of protein ratio, and tended to be stable after Lip-7S (1:1) and Lip-11S (1:0.75). Differential scanning calorimetry showed that Lip-7S had higher phase transition temperature (≥170.5 °C) and better rigid structure. During simulated digestion, Lip-7S (22.5 %) released less Morin than Lip (40.6 %) and Lip-11S (26.2 %), and effectively delayed the release of FFAs. The environmental stability of liposomes was effectively improved by protein modification, and 7S had better modification effect than 11S. This provides a theoretical basis for 7S and 11S modified liposomes, and also provides a data reference for searching for new materials for stabilization of liposomes.


Asunto(s)
Antígenos de Plantas , Globulinas , Liposomas , Proteínas de Almacenamiento de Semillas , Proteínas de Soja , Globulinas/química , Proteínas de Almacenamiento de Semillas/química , Proteínas de Soja/química , Liposomas/química , Antígenos de Plantas/química , Interacciones Hidrofóbicas e Hidrofílicas , Digestión , Tamaño de la Partícula , Enlace de Hidrógeno
20.
Adv Healthc Mater ; 13(18): e2303549, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38333940

RESUMEN

Periodontitis is a common oral disease accompanied by inflammatory bone loss. The pathological characteristics of periodontitis usually accompany an imbalance in the periodontal immune microenvironment, leading to difficulty in bone regeneration. Therefore, effective treatment strategies are needed to modulate the immune environment in order to treat periodontitis. Here, highly-oriented periodic lamellae poly(ε-caprolactone) electrospun nanofibers (PLN) are developed by surface-directed epitaxial crystallization. The in vitro result shows that the PLN can precisely modulate macrophage polarization toward the M2 phenotype. Macrophages polarized by PLN significantly enhance the migration and osteogenic differentiation of Bone marrow stromal cells. Notably, results suggest that the topographical cues presented by PLN can modulate macrophage polarization by activating YAP, which reciprocally inhibits the NF-κB signaling pathway. The in vivo results indicate that PLN can inhibit inflammatory bone loss and facilitate bone regeneration in periodontitis. The authors' findings suggest that topographical nanofibers with periodic lamellae is a promising strategy for modulating immune environment to treat inflammatory bone loss in periodontitis.


Asunto(s)
Nanofibras , Osteogénesis , Periodontitis , Poliésteres , Nanofibras/química , Periodontitis/terapia , Periodontitis/patología , Periodontitis/inmunología , Periodontitis/tratamiento farmacológico , Animales , Ratones , Poliésteres/química , Osteogénesis/efectos de los fármacos , Células RAW 264.7 , Macrófagos/inmunología , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Regeneración Ósea/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , FN-kappa B/metabolismo , Células Madre Mesenquimatosas/inmunología , Inmunomodulación/efectos de los fármacos , Transducción de Señal/efectos de los fármacos , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Proteínas Adaptadoras Transductoras de Señales/inmunología , Ratones Endogámicos C57BL , Masculino , Inflamación/patología , Proteínas Señalizadoras YAP
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA