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1.
Small ; 19(9): e2206141, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36538734

RESUMEN

Despite of extremely high theoretical capacity of Si (3579 mAh g-1 ), Si anodes suffer from pulverization and delamination of the electrodes induced by large volume change during charge/discharge cycles. To address those issues, herein, self-healable and highly stretchable multifunctional binders, polydioxythiophene:polyacrylic acid:phytic acid (PEDOT:PAA: PA, PDPP) that provide Si anodes with self-healability and excellent structural integrity is designed. By utilizing the self-healing binder, Si anodes self-repair cracks and damages of Si anodes generated during cycling. For the first time, it is demonstrated that Si anodes autonomously self-heal artificially created cracks in electrolytes under practical battery operating conditions. Consequently, this self-healable Si anode can still deliver a reversible capacity of 2312 mAh g-1 after 100 cycles with remarkable initial Coulombic efficiency of 94%, which is superior to other reported Si anodes. Moreover, the self-healing binder possesses enhanced Li-ion diffusivity with additional electronic conductivity, providing excellent rate capability with a capacity of 2084 mAh g-1 at a very high C-rate of 5 C.

2.
J Am Chem Soc ; 144(18): 8084-8095, 2022 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-35471843

RESUMEN

Polyvinyl polymers bearing pendant hole transport functionalities have been extensively explored for solution-processed hole transport layer (HTL) technologies, yet there are only rare examples of high anisotropic packing of the HT moieties of these polymers into substrate-parallel orientations within HTL films. For small molecules, substrate-parallel alignment of HT moieties is a well-established approach to improve overall device performance. To address the longstanding challenge of extension from vapor-deposited small molecules to solution-processable polymer systems, a fundamental chemistry tactic is reported here, involving the positioning of HT side chains within macromolecular frameworks by the construction of HT polymers having bottlebrush topologies. Applying state-of-the-art polymer synthetic techniques, various functional subunits, including triphenylamine (TPA) for hole transport and adhesion to the substrate, and perfluoro alkyl-substituted benzyloxy styrene for migration to the air interface, were organized with exquisite control over the composition and placement throughout the bottlebrush topology. Upon assembling the HT bottlebrush (HTB) polymers into monolayered HTL films on various substrates through spin-casting and thermal annealing, the backbones of HTBs were vertically aligned while the grafts with pendant TPAs were extended parallel to the substrate. The overall design realized high TPA π-stacking along the out-of-plane direction of the substrate in the HTLs, which doubled the efficiency of organic light-emitting diodes compared with linear poly(vinyl triphenylamine)s.

3.
Small ; 18(17): e2106937, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35344267

RESUMEN

The advancement of wearable electronics, particularly self-powered wearable electronic devices, necessitates the development of efficient energy conversion technologies with flexible mechanical properties. Recently, ionic thermoelectric (TE) materials have attracted great attention because of their enormous thermopower, which can operate capacitors or supercapacitors by harvesting low-grade heat. This study presents self-healable, stretchable, and flexible ionic TE composites comprising an ionic liquid (IL), 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (EMIM:OTf); a polymer matrix, poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP); and a fluoro-surfactant (FS). The self-healability of the IL-based composites originates from dynamic ion-dipole interactions between the IL, the PVDF-HFP, and the FS. The composites demonstrate excellent ionic TE properties with an ionic Seebeck coefficient (Si ) of ≈38.3 mV K-1 and an ionic figure of merit of ZTi  = 2.34 at 90% relative humidity, which are higher than the values reported for other IL-based TE materials. The IL-based ionic TE composites developed in this study can maintain excellent ionic TE properties under harsh conditions, including severe strain (75%) and multiple cutting-healing cycles.

4.
Proc Natl Acad Sci U S A ; 114(9): 2137-2142, 2017 02 28.
Artículo en Inglés | MEDLINE | ID: mdl-28193865

RESUMEN

An important goal of the modern soft matter science is to discover new self-assembly modalities to precisely control the placement of small particles in space. Spatial inhomogeneity of liquid crystals offers the capability to organize colloids in certain regions such as the cores of the topological defects. Here we report two self-assembly modes of nanoparticles in linear defects-disclinations in a lyotropic colloidal cholesteric liquid crystal: a continuous helicoidal thread and a periodic array of discrete beads. The beads form one-dimensional arrays with a periodicity that matches half a pitch of the cholesteric phase. The periodic assembly is governed by the anisotropic surface tension and elasticity at the interface of beads with the liquid crystal. This mode of self-assembly of nanoparticles in disclinations expands our ability to use topological defects in liquid crystals as templates for the organization of nanocolloids.

5.
Angew Chem Int Ed Engl ; 56(22): 6083-6087, 2017 05 22.
Artículo en Inglés | MEDLINE | ID: mdl-27901307

RESUMEN

Growth of three-dimensional cancer spheroids (CSs) in man-made hydrogels mimicking natural extracellular matrix is an important and challenging task. Herein, we report on a supramolecular temperature-responsive hydrogel designed for the growth and subsequent release of CSs. A filamentous hydrogel was formed at 37 °C from an aqueous suspension of cellulose nanocrystals surface-functionalized with temperature-responsive polymer molecules. The encapsulation of cells in the hydrogel enabled effective growth of CSs with dimensions determined by the concentration of cellulose nanocrystals in the hydrogel. On demand release of CSs without loss of cell viability and spheroid integrity was achieved upon hydrogel cooling. The tumorigenic properties of the released CSs were examined by encapsulating and re-growing them in fibrin hydrogel. The results in this work can be used in fundamental cancer research and in cancer drug screening.


Asunto(s)
Hidrogeles/química , Nanofibras/química , Neoplasias/patología , Esferoides Celulares/citología , Celulosa/química , Calor , Humanos , Células MCF-7 , Microscopía Electrónica de Rastreo
6.
Biomacromolecules ; 17(10): 3244-3251, 2016 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-27615746

RESUMEN

Natural extracellular matrices often have a filamentous nature, however, only a limited number of artificial extracellular matrices have been designed from nanofibrillar building blocks. Here we report the preparation of temperature-responsive nanofibrillar hydrogels from rod-shaped cellulose nanocrystals (CNCs) functionalized with a copolymer of N-isopropylacrylamide and N,N'-dimethylaminoethyl methacrylate. The composition of the copolymer was tuned to achieve gelation of the suspension of copolymer-functionalized CNCs at 37 °C in cell culture medium and gel dissociation upon cooling it to room temperature. The mechanical properties and the structure of the hydrogel were controlled by changing copolymer composition and the CNC-to-copolymer mass ratio. The thermoreversible gels were used for the encapsulation and culture of fibroblasts and T cells and showed low cytotoxicity. Following cell culture, the cells were released from the gel by reducing the temperature, thus, enabling further cell characterization. These results pave the way for the generation of injectable temperature-responsive nanofibrillar hydrogels. The release of cells following their culture in the hydrogels would enable enhanced cell characterization and potential transfer in a different cell culture medium.


Asunto(s)
Acrilamidas/química , Etilaminas/química , Matriz Extracelular/efectos de los fármacos , Hidrogeles/química , Metacrilatos/química , Acrilamidas/farmacología , Celulosa/química , Celulosa/farmacología , Medios de Cultivo/química , Etilaminas/farmacología , Fibroblastos/efectos de los fármacos , Humanos , Hidrogeles/farmacología , Metacrilatos/farmacología , Nanopartículas/química , Polímeros/química , Polímeros/farmacología , Linfocitos T/efectos de los fármacos
7.
Angew Chem Int Ed Engl ; 55(45): 14014-14018, 2016 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-27735118

RESUMEN

We report composite stimulus-responsive cholesteric catalytically active microgels derived from filamentous supramolecular building blocks: cellulose nanocrystals (CNCs). The variation in the microgel dimensions and pitch in response to the change in ambient conditions was governed by the polymer component. The cholesteric morphology of the microgels resulted from the self-organization of CNCs in spherical confinement. The microgels exhibited excellent structural integrity and functioned as microreactors in catalytic hydrolysis reactions and in the synthesis of metal nanoparticles. Because of these collective properties, the reported microgels show much promise for application in the design of functional responsive materials.

8.
Thorac Cardiovasc Surg ; 63(5): 360-6, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-24911900

RESUMEN

BACKGROUND: Anomalous aortic origin of coronary artery is a rare congenital condition in which the coronary artery arises from the opposite sinus of Valsalva. Although many patients are asymptomatic at the time of presentation or diagnosis, surgical correction is recommended due to the risk of ischemic sudden death. We describe seven cases of right coronary artery (RCA) arising from the left sinus of Valsalva, causing the hypoperfusion through RCA. PATIENTS AND METHODS: All patients underwent preoperative coronary angiography, echocardiography, and cardiac stress test (treadmill test [TMT], n = 4; technetium-99m sestamibi [MIBI], n = 3). In four patients, coronary computed tomography (CT) was performed. On the basis of preoperative test results, unroofing of the coronary artery (n = 3) or off-pump coronary artery bypass (OPCAB; n = 4; patients with coronary arterial occlusive disease) was performed. In two patients, intraoperative flow meter was performed and showed the improvement of flow rate through RCA. RESULTS: Postoperative CT angiography after OPCAB confirmed good graft patency (n = 4); CT angiography after unroofing demonstrated widely patent neo-orifice (n = 3). All patients underwent postoperative cardiac stress tests including TMT and MIBI, which revealed no evidence of ischemia. All patients were asymptomatic and returned to normal activities (mean follow-up, 41 months; 32-49 months). CONCLUSION: The appropriate surgical procedure based on specific anatomical details, perioperative evaluation, and follow-up by focusing on the ischemia may lead to successful surgical outcomes of this coronary anomaly.


Asunto(s)
Puente de Arteria Coronaria Off-Pump/métodos , Seno Coronario/anomalías , Anomalías de los Vasos Coronarios/diagnóstico , Anomalías de los Vasos Coronarios/cirugía , Vasos Coronarios/cirugía , Adulto , Anciano , Dolor en el Pecho/diagnóstico , Dolor en el Pecho/etiología , Angiografía Coronaria/métodos , Circulación Coronaria/fisiología , Seno Coronario/cirugía , Ecocardiografía Doppler/métodos , Prueba de Esfuerzo/métodos , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Cuidados Preoperatorios/métodos , Recuperación de la Función , Medición de Riesgo , Muestreo , Factores de Tiempo , Tomografía Computarizada por Rayos X/métodos , Resultado del Tratamiento , Adulto Joven
9.
Macromol Rapid Commun ; 35(4): 437-41, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24347368

RESUMEN

Diblock brush terpolymers (DBTs) with different fluorinated methacrylate-based block segments are synthesized through sequential ring-opening metathesis polymerizations and are used to prepare polymer thin films with predictable film thicknesses. These DBTs exhibit preferable substrate vertical alignments within the films, induced by the relatively lower surface energy of the fluorinated structural components, together with the overall cylindrical morphology of the brush architecture.


Asunto(s)
Polímeros/química , Metacrilatos/química , Nanotecnología , Polimerizacion , Polímeros/síntesis química
10.
Angew Chem Int Ed Engl ; 53(1): 156-9, 2014 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-24272951

RESUMEN

Gold nanoparticles, especially positron-emitter- labeled gold nanostructures, have gained steadily increasing attention in biomedical applications. Of the radionuclides used for nanoparticle positron emission tomography imaging, radiometals such as (64) Cu have been widely employed. Currently, radiolabeling through macrocyclic chelators is the most commonly used strategy. However, the radiolabel stability may be a limiting factor for further translational research. We report the integration of (64) Cu into the structures of gold nanoparticles. With this approach, the specific radioactivity of the alloyed gold nanoparticles could be freely and precisely controlled by the addition of the precursor (64) CuCl2 to afford sensitive detection. The direct incorporation of (64) Cu into the lattice of the gold nanoparticle structure ensured the radiolabel stability for accurate localization in vivo. The superior pharmacokinetic and positron emission tomography imaging capabilities demonstrate high passive tumor targeting and contrast ratios in a mouse breast cancer model, as well as the great potential of this unique alloyed nanostructure for preclinical and translational imaging.


Asunto(s)
Radioisótopos de Cobre , Oro , Nanopartículas/química , Neoplasias/diagnóstico por imagen , Tomografía de Emisión de Positrones/métodos , Animales , Radioisótopos de Cobre/química , Diagnóstico por Imagen , Oro/química , Ratones , Radioquímica , Radiografía
11.
J Am Chem Soc ; 135(11): 4203-6, 2013 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-23480169

RESUMEN

We describe a high-resolution, high-sensitivity negative-tone photoresist technique that relies on bottom-up preassembly of differential polymer components within cylindrical polymer brush architectures that are designed to align vertically on a substrate and allow for top-down single-molecule line-width imaging. By applying cylindrical diblock brush terpolymers (DBTs) with a high degree of control over the synthetic chemistry, we achieved large areas of vertical alignment of the polymers within thin films without the need for supramolecular assembly processes, as required for linear block copolymer lithography. The specially designed chemical compositions and tuned concentric and lengthwise dimensions of the DBTs enabled high-sensitivity electron-beam lithography of patterns with widths of only a few DBTs (sub-30 nm line-width resolution). The high sensitivity of the brush polymer resists further facilitated the generation of latent images without postexposure baking, providing a practical approach for controlling acid reaction/diffusion processes in photolithography.

12.
Biochem Biophys Res Commun ; 439(2): 315-20, 2013 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-23867822

RESUMEN

Oxidant-mediated death of lung epithelial cells due to cigarette smoking plays an important role in pathogenesis in lung diseases such as idiopathic pulmonary fibrosis (IPF). However, the exact mechanism by which oxidants induce epithelial cell death is not fully understood. Reactive oxygen species (ROS) modulator 1 (Romo1) is localized in the mitochondria and mediates mitochondrial ROS production through complex III of the mitochondrial electron transport chain. Here, we show that Romo1 mediates mitochondrial ROS production and apoptosis induced by oxidative stress in lung epithelial cells. Hydrogen peroxide (H2O2) treatment increased Romo1 expression, and Romo1 knockdown suppressed the cellular ROS levels and cell death triggered by H2O2 treatment. In immunohistochemical staining of lung tissues from patients with IPF, Romo1 was mainly localized in hyperplastic alveolar and bronchial epithelial cells. Romo1 overexpression was detected in 14 of 18 patients with IPF. TUNEL-positive alveolar epithelial cells were also detected in most patients with IPF but not in normal controls. These findings suggest that Romo1 mediates apoptosis induced by oxidative stress in lung epithelial cells.


Asunto(s)
Células Epiteliales/patología , Fibrosis Pulmonar Idiopática/patología , Pulmón/patología , Proteínas de la Membrana/metabolismo , Proteínas Mitocondriales/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Muerte Celular , Línea Celular , Células Epiteliales/metabolismo , Regulación de la Expresión Génica , Técnicas de Silenciamiento del Gen , Humanos , Fibrosis Pulmonar Idiopática/genética , Fibrosis Pulmonar Idiopática/metabolismo , Pulmón/citología , Proteínas de la Membrana/genética , Mitocondrias/metabolismo , Mitocondrias/patología , Proteínas Mitocondriales/genética
13.
ACS Omega ; 8(17): 15298-15305, 2023 May 02.
Artículo en Inglés | MEDLINE | ID: mdl-37151491

RESUMEN

MIL-101-NH2(Fe) is one of the effective photocatalytic metal-organic frameworks (MOFs) working under visible light. However, its powder-type form inhibits reusability in practical applications. In this study, we immobilized MIL-101-NH2(Fe) on a polymeric microfiber mesh to improve reusability while minimizing the loss of catalytic performance. To overcome the lack of surface functionality of the nylon fibers, an atomic layer deposition Al2O3 layer and NH2-BDC linker were introduced to facilitate uniform coating of the MOF on the fiber surface. The reactions of the metal precursor to the nylon substrate and NH2-BDC ligand of the MOF allow chemical bonding from the core to the shell of the entire hybrid catalytic materials. The resulting fiber-immobilized MOFs (Nylon@Al2O3@MOF) demonstrated high photocatalytic performance in the removal of RhB and Cr(VI) as representatives of organic dyes and heavy metals, respectively, while retaining over 85% of its efficiency after five cycles.

14.
Acta Pharm Sin B ; 13(4): 1660-1670, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-37139426

RESUMEN

To expand the single-dose duration over which noninvasive clinical and preclinical cancer imaging can be conducted with high sensitivity, and well-defined spatial and temporal resolutions, a facile strategy to prepare ultrasmall nanoparticulate X-ray contrast media (nano-XRCM) as dual-modality imaging agents for positron emission tomography (PET) and computed tomography (CT) has been established. Synthesized from controlled copolymerization of triiodobenzoyl ethyl acrylate and oligo(ethylene oxide) acrylate monomers, the amphiphilic statistical iodocopolymers (ICPs) could directly dissolve in water to afford thermodynamically stable solutions with high aqueous iodine concentrations (>140 mg iodine/mL water) and comparable viscosities to conventional small molecule XRCM. The formation of ultrasmall iodinated nanoparticles with hydrodynamic diameters of ca. 10 nm in water was confirmed by dynamic and static light scattering techniques. In a breast cancer mouse model, in vivo biodistribution studies revealed that the 64Cu-chelator-functionalized iodinated nano-XRCM exhibited extended blood residency and higher tumor accumulation compared to typical small molecule imaging agents. PET/CT imaging of tumor over 3 days showed good correlation between PET and CT signals, while CT imaging allowed continuous observation of tumor retention even after 10 days post-injection, enabling longitudinal monitoring of tumor retention for imaging or potentially therapeutic effect after a single administration of nano-XRCM.

15.
Microbiol Spectr ; 11(6): e0144623, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-37811937

RESUMEN

IMPORTANCE: In this study, we confirmed the binding of M13KO7 to Potato virus Y (PVY) using enzyme-linked immunosorbent assay. M13KO7 is a "bald" bacteriophage in which no recombinant antibody is displayed. M13KO7 is easy to propagate by using Escherichia coli, making this method more reasonable in economic perspective. Based on this study, we suggest that M13KO7 detection system has applicability as a novel biological tool for the detection of PVY.


Asunto(s)
Bacteriófagos , Potyvirus , Bacteriófagos/genética , Ensayo de Inmunoadsorción Enzimática , Escherichia coli/genética , Enfermedades de las Plantas
17.
J Chest Surg ; 55(1): 44-48, 2022 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-35115421

RESUMEN

BACKGROUND: Although classical multi-port video-assisted thoracic surgery has been widely performed, single-incision thoracoscopic surgery (SITS) is a popular surgical technique for the treatment of primary spontaneous pneumothorax (PSP). However, the inconvenient alignment of instruments and the limited field of view occasionally make surgeons convert from SITS to multi-port surgery or extend the incision. This study aimed to present an easy and safe SITS technique for PSP using a spinal needle. METHODS: In total, 139 patients underwent SITS between May 2011 and December 2017. We used a spinal needle to hook the bulla or bleb, and wedge resection was performed through a small incision. Patients' medical records were reviewed retrospectively, and a telephone survey was conducted to investigate the recurrence rate. RESULTS: The mean age of the 139 patients was 23.62±9.60 years. The mean operative time was 36.69±14.64 minutes, and multi-port conversion was not performed. The mean postoperative hospital stay was 3.00±0.78 days, and the mean indwelling chest tube duration was 1.97±0.77 days. No complications were observed. In the mean follow-up period of 86.75±23.20 months, recurrence of pneumothorax was found in 3 patients. CONCLUSION: We suggest that SITS for PSP with the aid of a spinal needle to replace a grasper is a safe and easy technique that only requires a small incision.

18.
Carbohydr Polym ; 275: 118754, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34742448

RESUMEN

Herein, environmentally benign chitin nanofiber (ChNF) membranes were fabricated by regulating suspension behavior. The introduction of zeolitic imidazole frameworks (ZIF-8) into the composite membranes led to the domain formation of ChNF derived by coordinative interaction, resulting in pore size-tunable membranes. Based on the rheological, morphological, and structural characterizations, the driving force of pore-size control was studied in the aqueous suspension of ChNF and ZIF-8 according to the relative concentration. At critical concentration, the 30-ChNF membrane presents superior water permeance (40 LMH h-1) while maintaining a high rejection rate (>80% for all organic dyes). Moreover, the molecular size cut-off of the composite membranes for dyes can be controlled in the range of less than 1 nm to 2 nm. The experimental results provide a simple strategy for the preparation of pore tunable ChNF membranes using MOF with high mechanical strength, good durability, high flux, dye rejection, and antifouling ability.


Asunto(s)
Quitina/química , Imidazoles/química , Estructuras Metalorgánicas/química , Nanofibras/química , Zeolitas/química , Animales , Incrustaciones Biológicas/prevención & control , Bovinos , Quitina/farmacología , Contaminantes Ambientales/antagonistas & inhibidores , Contaminantes Ambientales/metabolismo , Imidazoles/farmacología , Estructuras Metalorgánicas/farmacología , Tamaño de la Partícula , Albúmina Sérica Bovina/antagonistas & inhibidores , Albúmina Sérica Bovina/metabolismo , Propiedades de Superficie , Zeolitas/farmacología
19.
J Chest Surg ; 55(1): 85-87, 2022 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-35115427

RESUMEN

Diaphragmatic hernias have been reported in 0.8%-1.6% of patients who experience blunt chest trauma. The hernia is assumed to form as a result of direct diaphragmatic violation or significant intraabdominal or intrathoracic pressure caused by the trauma. Some reports have described cases of delayed diaphragmatic hernia and subsequent stomach perforation that occurred a few days to several years after an accident. We report an extremely rare case of diaphragmatic herniation in which the process from initial blunt trauma to visceral organ perforation took only 2 days, without any evidence of herniation on the initial X-ray or computed tomography. Delayed diaphragmatic herniation and subsequent visceral organ perforation should not be missed during the period immediately after blunt chest trauma.

20.
Artículo en Inglés | MEDLINE | ID: mdl-36288400

RESUMEN

Defense against chemical warfare agents (CWAs) is regarded as a top priority for the protection of humanity, but it still depends on physical protection with severe limitations such as residual toxicity and post-treatment requirement. In this study, a strategically designed functional polymeric substrate was composited with a metal-organic framework catalyst to remove toxicity immediately. A series of PMMA-BPEI copolymers exhibited high processability as a coating and accelerated the catalytic activity of Zr(IV)-based metal-organic framework catalysts (UiO-66). Among them, PMB12_40 composite coating on a cotton fabric, containing a PMMA-BPEI copolymer (PMMA/BPEI = 1/2) and 40% of UiO-66 catalyst, can efficiently decompose nerve agent simulants (methyl-paraoxon) under both liquid phase (t1/2 = 0.14 h) and humidified (t1/2 = 4.8 h) conditions. Moreover, a real agent, GD, was decomposed 100% by PMB12_40 in 4 h at 25 °C and 65% relative humidity. On the basis of superior catalytic activity, the PMB composites are anticipated to be a potential material for active chemical protection coating.

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