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1.
BMC Pregnancy Childbirth ; 24(1): 432, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38886682

RESUMEN

BACKGROUND: IgA nephropathy (IgAN) is the most common cause of primary glomerulonephritis, with complex pathogenic mechanisms involving abnormal B-cell activation. As a novel biologic agent, telitacicept inhibits both B-lymphocyte stimulating factor and a proliferation-inducing ligand. It also inhibits both B cells and plasma cells and the production of galactose-deficient IgA1 (Gd-IgA1) and its autoantibodies, thus exerting an immunosuppressive effect. Women with IgAN are at a higher risk of adverse pregnancy outcomes such as preeclampsia and miscarriage, especially those with uncontrolled massive proteinuria and advanced chronic kidney disease. Therefore, IgAN disease control before and during pregnancy is essential. Here, we report the case of a woman with IgAN who had a successful pregnancy with significant improvement and long-term remission after treatment with telitacicept. This is the first report of a pregnancy following exposure to telitacicept. CONCLUSION: This report describes the efficacy of telitacicept in patients with IgAN and explores its value in women of childbearing age, suggesting effective and safe treatment options for women who wish to conceive.


Asunto(s)
Glomerulonefritis por IGA , Complicaciones del Embarazo , Humanos , Femenino , Glomerulonefritis por IGA/tratamiento farmacológico , Glomerulonefritis por IGA/complicaciones , Embarazo , Adulto , Complicaciones del Embarazo/tratamiento farmacológico , Resultado del Embarazo
2.
Small ; 18(24): e2202047, 2022 06.
Artículo en Inglés | MEDLINE | ID: mdl-35570715

RESUMEN

Ultralight and highly flexible aerogel sensors, composed of reduced graphene oxide cross-linked by sustainable-macromolecule-derived carbon, are prepared via facile freeze-drying and thermal annealing. The synergistic combination of cross-linked graphene nanosheets and micrometer-sized honeycomb pores gives rise to the exceptional properties of the aerogels, including superior compressibility and resilience, good mechanical strength and durability, satisfactory fire-resistance, and outstanding electromechanical sensing performances. The corresponding aerogel sensors, operated at an ultralow voltage of 0.2 V, can efficiently respond to a wide range of strains (0.1-80%) and pressures (13-2750 Pa) even at temperatures beyond 300 °C. Moreover, the ultrahigh-pressure sensitivity of 10 kPa-1 and excellent sensing stability and durability are accomplished. Strikingly, the aerogel sensors can also sense the vibration signals with ultrahigh frequencies of up to 4000 Hz for >1 000 000 cycles, significantly outperforming those of other sensors. These enable successful demonstration of the exceptional performance of the cross-linked graphene-based biomimetic aerogels for sensitive monitoring of mechanical signals, e.g., acting as wearable devices for monitoring human motions, and for nondestructive monitoring of cracks on engineering structures, showing the great potential of the aerogel sensors as next-generation electronics.


Asunto(s)
Grafito , Dispositivos Electrónicos Vestibles , Carbono/química , Electrónica , Grafito/química , Humanos , Vibración
3.
Bioconjug Chem ; 33(3): 444-451, 2022 03 16.
Artículo en Inglés | MEDLINE | ID: mdl-35138820

RESUMEN

Membrane-less scenarios that involve liquid-liquid phase separation (coacervation) provide clues for how protocells might emerge. Here, we report a versatile approach to construct coacervates by mixing fatty acid with biomolecule dopamine as the protocell model. The coacervate droplets are easily formed over a wide range of concentrations. The solutes with different interaction characteristics, including cationic, anionic, and hydrophobic dyes, can be well concentrated within the coacervates. In addition, reversible self-assemblies of the coacervates can be controlled by concentration, pH, temperature, salinity, and bioreaction realizing cycles between compartmentalization and noncompartmentalization. Through in situ dopamine polymerization, the stability of coacervate droplets is significantly improved, leading to higher resistance toward external factors. Therefore, the coacervates based on fatty acid and dopamine could serve as a bottom-up membrane-less protocell model that provides the links between the simple (small molecule) and complex (macromolecule) systems in the process of cell evolution.


Asunto(s)
Células Artificiales , Células Artificiales/química , Dopamina , Ácidos Grasos , Interacciones Hidrofóbicas e Hidrofílicas , Sustancias Macromoleculares
4.
Macromol Rapid Commun ; 43(2): e2100619, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34662467

RESUMEN

Bio-based and biodegradable polymer composites, most notably poly(l-lactic acid) (PLLA) and poly(3-hydroxybutyrate) (PHB), represent a promising solution to replace conventional petroleum-based plastics. However, the brittleness and low miscibility of PLLA and PHB remain two major obstacles to practical applications. In this work, first PLLA/PHB blends are reported by melt mixing with a rigid component, poly(methyl methacrylate) (PMMA). Driven by favorable entropy, PMMA forms an interfacial nanolayer, which transforms the morphology of resultant blends. The ternary blends show 55-fold increase in elongation, 50-fold in toughness, and metal-like malleability (≈180° bending and twisting), while retaining its high stiffness (3.4 GPa) and strength (≈50 MPa). The mechanical improvement arises from numerous craze fibrils and shear deformation of the matrix, induced by the incorporated PMMA. Furthermore, this generic strategy can be applied to design other mechanically robust biocomposites for advanced green devices.


Asunto(s)
Poliésteres , Polímeros , Polimetil Metacrilato
5.
Nephrology (Carlton) ; 26(5): 432-441, 2021 May.
Artículo en Inglés | MEDLINE | ID: mdl-33501721

RESUMEN

AIMS: Immunoglobulin A nephropathy (IgAN) is the most common primary glomerular disease to cause end-stage kidney disease. This study investigated the difference in urinary exosomal circular RNA (circRNA) expression profiles between patients with IgAN and healthy controls (HCs), for better understanding of gene regulation in exosomes of IgAN patients. METHODS: A pairwise comparison of urinary circRNA expression profiles between IgAN patients and HCs was performed using methods, including high-throughput sequencing and quantitative polymerase chain reaction. Moreover, the potential functions of differentially expressed circRNAs (DECs) in IgAN were investigated by gene ontology (GO) enrichment analysis; Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis; and the circRNA-miRNA-mRNA network. RESULTS: We identified 450 upregulated and 26 downregulated circRNAs in the IgAN patients. GO analysis showed that these enriched circRNAs might regulate primary miRNA processing, the ability of angiotensin receptor binding, and stress fibre function. KEGG analysis suggested these DECs may be closely associated with the phosphoinositide-3-kinase-protein kinase B/Akt (PI3K-Akt) signalling pathways. Network analysis revealed the relationship between circRNAs and their target genes. CONCLUSION: The identified DECs may be useful for both researches on molecular aetiology of IgAN and development of potentially novel non-invasive biomarkers of IgAN.


Asunto(s)
Exosomas/genética , Glomerulonefritis por IGA/orina , ARN Circular/orina , Adulto , Regulación de la Expresión Génica , Glomerulonefritis por IGA/genética , Glomerulonefritis por IGA/metabolismo , Humanos , Masculino , Persona de Mediana Edad , ARN Circular/biosíntesis , Adulto Joven
6.
Ren Fail ; 42(1): 667-672, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-32713238

RESUMEN

PURPOSE: The association of serum elabela (ELA) and apelin with the progression of chronic kidney disease (CKD) is unknown. We determined if serum ELA and apelin levels were associated with CKD stage. METHODS: This observational study involved 60 CKD patients and 20 healthy, age-, race-, and gender-matched controls. The participants were grouped according to renal function as follows: normal control group, CKD1 group (stage-1 CKD, 20 patients), CKD3 group (stage-3 CKD, 20 patients), and CKD5 group (stage-5 CKD, 20 patients) in accordance with the Kidney Disease Outcomes - Quality Initiative criteria. We recorded the demographic, clinical, and biochemical data of all participants. Serum ELA and apelin levels were measured using commercially available enzyme-linked immunosorbent assays. RESULTS: Serum ELA levels gradually and significantly declined with decreases in the estimated glomerular filtration rate (eGFR). Serum ELA showed significant negative correlations with serum creatinine (r = -0.529, p < .001), blood urea nitrogen (r = -0.575, p < .001), systolic blood pressure (r = -0.455, p < .001), and diastolic blood pressure (r = -0.450, p < .001), and significant positive correlations with hemoglobin (r = 0.523, p < .001) and eGFR (r = 0.728, p < .001). Multiple regression analysis showed that eGFR independently influenced serum ELA levels. No significant association was found between serum apelin levels and CKD progression. CONCLUSION: In CKD patients, serum ELA levels decreased with decreasing eGFR. This finding may provide a new target for the prediction, diagnosis, and staging of CKD.


Asunto(s)
Apelina/sangre , Tasa de Filtración Glomerular , Hormonas Peptídicas/sangre , Insuficiencia Renal Crónica/sangre , Adulto , Anciano , Biomarcadores/sangre , Presión Sanguínea , Nitrógeno de la Urea Sanguínea , Estudios de Casos y Controles , Creatinina/sangre , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Insuficiencia Renal Crónica/fisiopatología
7.
Macromol Rapid Commun ; 40(5): e1800047, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-29774615

RESUMEN

Strength and toughness are the two most important prerequisites for structural applications. Unfortunately, these two properties are often in conflict in materials. Here, an effective and yet practical strategy is proposed to simultaneously strengthen and toughen poly(l-lactide) (PLLA) using a simple rigid-rubber "reinforcing element." This element consists of a rigid graphene oxide (GO) sheet covalently coupled with poly(caprolactone-co-lactide) (PCLLA) rubbery layers, which can be easily synthesized and incorporated into PLLA matrix to develop composites with well-tailored GO/PLLA interfaces. It is demonstrated that by adding the "reinforcing element," i.e., GO-graft-rubber-graft-polyd-lactide), PLLA exhibits higher strength and higher toughness, which could be attributed to the synergy of rigid GO and rubbery PCLLA working in tandem during deformation. It is further demonstrated that this strategy can also be applied to other filler systems, such as clay and particulate polyhedral oligomeric silsesquioxane, and other polymer systems, such as poly(methyl methacrylate). The strategy could be considered as a general design principle for reinforcing materials where both strength and toughness are the key concerns.


Asunto(s)
Ensayo de Materiales , Nanocompuestos/química , Poliésteres/química , Rastreo Diferencial de Calorimetría , Grafito/química , Espectroscopía de Resonancia Magnética , Polímeros/síntesis química , Polímeros/química , Goma/química , Resistencia a la Tracción
8.
Pharm Biol ; 57(1): 250-254, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30957612

RESUMEN

CONTEXT: In vitro and in vivo research has shown that curcumin can alleviate diabetes and the relevant complications. OBJECTIVE: To investigate the effect of curcumin on gestational diabetes (GD). MATERIALS AND METHODS: C57 BL/KsJdb/+(db/+) mice and C57 BL/KsJ+/+ mice (10-12 weeks old) were divided into four groups (n = 15): normal pregnancy (C57 BL/KsJ+/+), GD (C57 BL/KsJdb/+), GD plus low dose curcumin (50 mg/kg, orally gavage every day) and GD plus high dose curcumin (100 mg/kg, orally gavage every day). The tolerance of glucose and insulin were measured on gestation day 10. Body weight at birth and litter size of offspring were investigated, and the expression of oxidative stress factors [thiobarbituric acid reactive substance (TBARS), glutathione (GSH), superoxide dismutase (SOD) and catalase (CAT)] and AMP-activated protein kinase (AMPK), phospho-AMPK, histone deacetylases 4 (HDAC4), pHDAC4 and glucose-6-phosphatase (G6Pase) in the livers were analyzed by ELISA and Western blot on gestation day 20. RESULTS: High dose curcumin could partly ameliorate the intolerance of glucose and insulin, and completely restore the litter size and the body weight of GD mice through decreased TBARS expression (p < 0.05) and increased GSH, SOD and CAT expression (p < 0.05). Enhanced AMPK activation, accompanied with decreased HDAC4 and G6Pase expression (p < 0.05) were partly contributed to the alleviation of GD mediated by curcumin. CONCLUSIONS: Although further detailed mechanism needs to be deciphered, curcumin can be considered as an alternative treatment for gestational diabetes.


Asunto(s)
Proteínas Quinasas Activadas por AMP/efectos de los fármacos , Curcumina/farmacología , Diabetes Mellitus Experimental/tratamiento farmacológico , Diabetes Gestacional/tratamiento farmacológico , Proteínas Quinasas Activadas por AMP/metabolismo , Animales , Western Blotting , Catalasa/metabolismo , Curcumina/administración & dosificación , Diabetes Mellitus Experimental/fisiopatología , Diabetes Gestacional/fisiopatología , Relación Dosis-Respuesta a Droga , Ensayo de Inmunoadsorción Enzimática , Femenino , Glucosa/metabolismo , Glutatión/metabolismo , Insulina/metabolismo , Tamaño de la Camada/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Estrés Oxidativo/efectos de los fármacos , Embarazo , Superóxido Dismutasa/metabolismo
9.
Langmuir ; 32(36): 9265-75, 2016 09 13.
Artículo en Inglés | MEDLINE | ID: mdl-27550631

RESUMEN

We report one-pot synthesis of Fe(III)-polydopamine (PDA) complex nanospheres, their structures, morphology evolution, and underlying mechanism. The complex nanospheres were synthesized by introducing ferric ions into the reaction mixture used for polymerization of dopamine. It is verified that both the oxidative polymerization of dopamine and Fe(III)-PDA complexation contribute to the "polymerization" process, in which the ferric ions form coordination bonds with both oxygen and nitrogen, as indicated by X-ray absorption fine-structure spectroscopy. In the "polymerization" process, the morphology of the complex nanostructures is gradually transformed from sheetlike to spherical at the feed Fe(III)/dopamine molar ratio of 1/3. The final size of the complex spheres is much smaller than its neat PDA counterpart. At higher feed Fe(III)/dopamine molar ratios, the final morphology of the "polymerization" products is sheetlike. The results suggest that the formation of spherical morphology is likely to be driven by covalent polymerization-induced decrease of hydrophilic functional groups, which causes reself-assembly of the PDA oligomers to reduce surface area. We also demonstrate that this one-pot synthesis route for hybrid nanospheres enables the facile construction of carbonized PDA (C-PDA) nanospheres uniformly embedded with Fe3O4 nanoparticles of only 3-5 nm in size. The C-PDA/Fe3O4 nanospheres exhibit catalytic activity toward oxygen reduction reaction and deliver a stable discharge voltage for over 200 h when utilized as the cathode in a primary Zn-air battery and are also good recyclable catalyst supports.

10.
Small ; 10(17): 3544-50, 2014 Sep 10.
Artículo en Inglés | MEDLINE | ID: mdl-24515964

RESUMEN

A carbon microbelt (CMB) aerogel with good selective sorption can be produced in large scale by using waste paper as a precursor. The CMB aerogel shows highly efficient sorption of organic liquids (pump oil: up to 188 times its own weight; chloroform: up to 151 times its own weight). Moreover, the CMB aerogel can be regenerated many times without decrease of sorption capacity by distillation, or squeezing depending on the type of pollutants.

11.
Chemistry ; 20(41): 13226-33, 2014 Oct 06.
Artículo en Inglés | MEDLINE | ID: mdl-25168708

RESUMEN

An electrofluorochromic (EFC) conjugated copolymer (PEFC) containing carbazole and benzothiadiazole (BTD) moieties is synthesized through Suzuki coupling followed by electrochemical polymerization, resulting in a nanoporous EFC polymer electrode. The electrode exhibits high sensitivity and selectivity in the EFC detection of cyanide anions (CN(-)) in largely aqueous electrolyte (67 vol % water) because electrochemical oxidation of PEFC leads to significant fluorescence quenching, and the presence of different concentrations (1 to 100 µM) of CN(-) in the electrolyte can weaken the oxidative quenching to substantially different extents. Although PEFC is hydrophobic in the neutral state, it is converted to radical cation/dication states upon oxidation, rendering the PEFC some hydrophilicity. Moreover, its nanoporous morphology provides a large surface area and short diffusion distance, facilitating the movement of CN(-) in the electrolyte into the PEFC film to interact with receptors. Density functional theory calculations show that the noncovalent interaction between electron-deficient BTD and nucleophilic CN(-) is energy favorable in the oxidized states in both aqueous and organic media, suggesting that the specific π(-)-π(+) interaction plays the main role in the CN(-) detection.

12.
Chemistry ; 20(25): 7776-83, 2014 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-24862644

RESUMEN

Inspired by the high transition-metal-ion content in mussel glues, and the cross-linking and mechanical reinforcement effects of some transition-metal ions in mussel threads, high concentrations of nickel(II), cobalt(II), and manganese(II) ions have been purposely introduced into the reaction system for dopamine polymerization. Kinetics studies were conducted for the Ni(2+)-dopamine system to investigate the polymerization mechanism. The results show that the Ni(2+) ions could accelerate the assembly of dopamine oligomers in the polymerization process. Spectroscopic and electron microscopic studies reveal that the Ni(2+) ions are chelated with polydopamine (PDA) units, forming homogeneous Ni(2+)-PDA complexes. This facile one-pot approach is utilized to construct transition-metal-ion-PDA complex thin coatings on graphene oxide, which can be carbonized to produce robust hybrid nanosheets with well-dispersed metallic nickel/metallic cobalt/manganese(II) oxide nanoparticles embedded in PDA-derived thin graphitic carbon layers. The nickel-graphene hybrid prepared by using this approach shows good catalytic properties and recyclability for the reduction of p-nitrophenol.


Asunto(s)
Dopamina/metabolismo , Grafito/química , Grafito/síntesis química , Nanopartículas del Metal/química , Animales , Bivalvos , Polimerizacion
13.
Eur J Med Res ; 29(1): 94, 2024 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-38297369

RESUMEN

BACKGROUND: Elabela, a recently discovered hormonal peptide containing 32 amino acids, is a ligand for the apelin receptor. It can lower blood pressure and attenuate renal fibrosis. However, the clinicopathological relationship between Elabela level and renal damage caused by benign hypertension (BHT) and malignant hypertension (MHT) has not been elucidated. Therefore, we investigated the clinicopathological correlation between serum Elabela level and renal damage caused by BHT and MHT. METHODS: The participants comprised 50 patients and 25 age-matched healthy adults. The 50 patients were separated into two groups: MHT (n = 25) and BHT groups (n = 25). We analyzed their medical histories, demographics, and clinical examinations, including physical and laboratory tests. RESULTS: The results showed that serum Elabela level decreased gradually with a continuous increase in blood pressure from the healthy control group, BHT, to MHT. Moreover, Elabela levels negatively correlated with BMI (R = - 0.27, P = 0.02), SBP (r = - 0.64, P < 0.01), DBP (r = - 0.58, P < 0.01), uric acid (r = - 0.39, P < 0.01), bun (r = - 0.53, P < 0.01), and Scr (r = - 0.53 P < 0.01) but positively correlated with eGFR (r = 0.54, P < 0.01). Stepwise multivariate linear regression analysis showed that SBP was the variable most related to Elabela (t = - 5.592, P < 0.01). CONCLUSIONS: Serum Elabela levels decreased in patients with hypertension, especially malignant hypertension, and has the potential to be a marker of hypertension-related kidney damage.


Asunto(s)
Hipertensión Maligna , Hipertensión , Adulto , Humanos , Riñón , Presión Sanguínea , Análisis Multivariante
14.
Hemodial Int ; 2024 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-38924346

RESUMEN

Few studies have reported the application of vacuum-sealing drainage of infected dialysis vascular access wounds. Herein, we present a case of buttonhole-related arteriovenous fistula infection treated with vacuum-sealing drainage. A 53-year-old female hemodialysis patient was hospitalized with an inflamed arteriovenous fistula. The patient underwent non-tunneled catheterization for dialysis and was treated with moxifloxacin and vancomycin for staphylococcal infection. On Day 3, the skin overlying the inflamed fistula was ulcerated, resulting in severe hemorrhage. Emergency surgery was performed along with vacuum-sealing drainage for fistula reconstruction. Vacuum-sealing drainage accelerated the recovery of the wound without complications. No further access complications occurred during over a 3-year follow-up.

15.
Eur J Med Res ; 29(1): 208, 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38549160

RESUMEN

OBJECTIVE: Secondary hyperparathyroidism (SHPT) is a common complication of chronic kidney disease (CKD). Hungry bone syndrome (HBS) after parathyroidectomy (PTX) is a serious complication, which can lead to diarrhea, convulsion, arrhythmia and even death. This study was aimed to determine the risk factors for HBS after PTX in dialysis patients with SHPT and construct a nomogram prediction model to predict the incidence of postoperative complications. METHODS: Clinical data were collected from 80 maintenance hemodialysis (MHD) patients with SHPT who received total PTX in the Second Hospital of Jilin University from January 2018 to September 2021. In line with the inclusion and exclusion criteria, totally 75 patients were finally enrolled for analysis. Patients were divided into two groups for retrospective analysis according to the severity of postoperative HBS, including HBS group and non-HBS (N-HBS) group. Univariate and multivariate logistic regression analyses were conducted to determine the risk factors for postoperative HBS. Afterwards, the receiver operating characteristic (ROC) curves were plotted based on the statistical analysis results, aiming to compare the prediction effects of different predicting factors. Finally, the nomogram was established to evaluate the occurrence probability of postoperative complications predicted by the risk factors. RESULTS: Among the 75 patients, 32 had HBS (HBS group), while 43 did not have HBS (N-HBS group). Univariate analysis results indicated that, the preoperative intact parathyroid hormone (iPTH) and serum alkaline phosphatase (ALP) levels in HBS group were significantly higher than those in N-HBS group, while preoperative hemoglobin and preoperative albumin (Alb) levels were significantly lower than those in N-HBS group. As discovered by multivariate logistic regression analysis, preoperative iPTH (OR = 1.111, P = 0.029) and ALP (OR = 1.010, P < 0.001) were the independent risk factors for postoperative HBS. ROC curve analysis suggested that the area under the curve (AUC) values of these two indicators were 0.873 and 0.926, respectively (P < 0.0001). Subsequently, the nomogram model for predicting HBS was constructed. The model verification results indicated that the predicted values were basically consistent with the measured values, with the C-index of 0.943 (95% CI 0.892-0.994). Besides, the calibration curve was consistent with the ideal curve, demonstrating the favorable accuracy and discrimination of the model. CONCLUSIONS: Preoperative iPTH and preoperative ALP are the risk factors for postoperative HBS, which can be used to guide the early clinical intervention.


Asunto(s)
Enfermedades Óseas Metabólicas , Hiperparatiroidismo Secundario , Hipocalcemia , Humanos , Paratiroidectomía/efectos adversos , Paratiroidectomía/métodos , Diálisis Renal/efectos adversos , Estudios Retrospectivos , Nomogramas , Hipocalcemia/epidemiología , Hipocalcemia/etiología , Hipocalcemia/cirugía , Hiperparatiroidismo Secundario/etiología , Hiperparatiroidismo Secundario/cirugía , Hormona Paratiroidea , Complicaciones Posoperatorias/epidemiología , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/cirugía
16.
Chem Asian J ; 19(12): e202400236, 2024 Jun 17.
Artículo en Inglés | MEDLINE | ID: mdl-38679783

RESUMEN

A series of conjugated polymers bearing thiophene-based donors and pyromellitic diimide (PMDI) acceptor were prepared, and their electrochromic (EC) properties were studied via using fabricated thin-film EC devices. It was observed that structurally regular alternating polymers with fewer (1 and 2) thiophene donors do not exhibit any EC properties while increasing the number of donors eventually led to the emergence of orange-red-to-green colour switching. On this basis, two more random co-polymers containing higher donor-to-acceptor ratios were synthesized to further improve EC switching properties. The two polymers, which bear a PMDI-to-thiophene ratio of ca. 1 : 7 and 1 : 8, revealed orange red-to-blue colour switching and generally improved optical contrasts and switching speeds in both the visible and near infra-red (NIR) region. In addition, the subtle modulation of polymer colour and hue via variation of the number of thiophene donors was evident through colorimetric study. This work therefore demonstrates the potential and possibility of using the PMDI acceptor unit to construct EC-active conjugated polymers, and considerations for future tuning of colour and switching performances.

17.
Small ; 9(4): 596-603, 2013 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-23117928

RESUMEN

In this work, monodisperse polydopamine (PDA) spheres with tunable diameters have been synthesized through a facile and low cost method using a deionized water and alcohol mixed solvent. The PDA spheres possess surface functional groups (-OH, -NH(2)), exhibiting an extraordinary versatile active nature. It is demonstrated that the PDA spheres could serve as an active template for the convenient synthesis of various nanostructures, e.g., MnO(2) hollow spheres or PDA/Fe(3)O(4) and PDA/Ag core/shell nanostructures. No surface modification or special treatment is required for the synthesis of these nanostructures, which makes the fabrication process simple and very convenient. The novel application of PDA/Fe(3)O(4) spheres as fillers in nanocomposites for high-performance capacitors is demonstrated, indicating a promising practicality. The PDA spheres provide a new general platform not only for the facile assembly of nanostructures but also a green synthetic template for practical applications.


Asunto(s)
Indoles/química , Nanoestructuras/química , Polímeros/química , Nanotecnología , Propiedades de Superficie
18.
Langmuir ; 29(4): 1238-44, 2013 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-23289718

RESUMEN

Clay-based functional hydrogels were facilely prepared via a bioinspired approach. Montmorillonite (clay) was exfoliated into single layers in water and then coated with a thin layer of polydopamine (PDOPA) via in situ polymerization of dopamine under basic aqueous conditions. When a small amount of ferric salt was added into aqueous suspensions of the polydopamine-coated clay (D-clay), D-clay and Fe(3+) ions could rapidly self-assemble into three-dimensional networks through the formation of coordination bonds. Consequently, supramolecular hydrogels were formed at very low D-clay contents. Rheological measurements show that the D-clay/Fe(3+) hydrogels exhibit fairly elastic response in low stain range, and have self-healing capability upon removal of applied large stress. More importantly, the hydrogels can be used as adsorbents to effectively remove Rhodamine 6G (Rh6G), an organic pollutant, from water. UV-vis absorption spectra of the Rh6G-loaded hydrogels show bands related to π-π stacking interactions between the aromatic moieties of PDOPA and Rh6G, confirming the formation of PDOPA/Rh6G complex on the surface of D-clay.

19.
Macromol Rapid Commun ; 34(5): 431-6, 2013 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-23281193

RESUMEN

Azulene-containing conjugated polymers with near-infrared absorption up to 1.5 µm and beyond are achieved by treating with trifluoroacetic acid (TFA). Density functional theory calculations reveal that the near-infrared absorption arises from a strong intramolecular charge transfer transition on the polymer backbone, and the near-infrared absorption can be tuned by the degree of protonation. Furthermore, TFA treated polymers show a ten-fold enhancement in electrochromic contrast and significantly improved switching stability, suggesting that these polymers are promising candidates for fabrication of the first generation organic near-infrared devices.

20.
Macromol Rapid Commun ; 34(19): 1563-8, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23996916

RESUMEN

Rocket-like vesicles formed are composed of poly(acrylic aicd) (PMAA )/poly(ethylene glycol) (PEG) complex coated hollow silica spheres, and the structure and composition of the vesicles are characterized using TGA, (1)H NMR, FTIR, and TEM. Although only one-third of EG units of PEG brushes grafted to hollow silica spheres form the complex with PMAA via hydrogen bonding, the first "booster" layer composed of PMAA/PEG complex can provide secure encapsulation of model compound calcein blue under an acidic condition. The second "booster" layer composed of PEG brushes can be formed by changing acidic pH to 7.4 through the disassociation of the PMAA/PEG complex. A higher molecular weight PMAA exhibits a faster disassembly due to the formation of a looser PMAA/PEG complex on the surfaces of hollow silica spheres.


Asunto(s)
Portadores de Fármacos/química , Polietilenglicoles/química , Ácidos Polimetacrílicos/química , Dióxido de Silicio/química , Resinas Acrílicas/química , Concentración de Iones de Hidrógeno , Propiedades de Superficie
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