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2.
Opt Express ; 27(8): A397-A403, 2019 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-31052891

RESUMEN

The fabrication and feasibility assessment of n-side up, thin-epilayer, AlGaInP-based vertical light-emitting-diodes (LEDs; emitting area: 1 mm × 1 mm) with a copper-invar-copper-composite metal (CIC) substrate was obtained by wafer bonding and epilayer transferring technologies. The structure of CIC substrate is a top Cu layer of 20 µm, a middle Invar layer of 64 µm, and a bottom Cu layer of 20 µm. The invar layer consists of Fe and Ni at a ratio of 70% to 30%. The coefficient of thermal expansion for CIC is about 6.1 × 10-6 /K, which is similar to that of the GaAs substrate (5.7 × 10-6 /K) and AlGaInP epilayers. Due to the high thermal conductivity (160 W/m-K) of 104-µm-thick CIC, the high performances of the packaged LEDs are obtained. They present a low red shift phenomenon (from 623 to 642 nm for 100 mA to 1 A) and a high output power 212 mW at 800 mA. The CIC substrate can be extended to fabricate high-efficiency thin film LEDs with conventional vertical electrodes.

3.
Insect Mol Biol ; 27(6): 752-765, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29892979

RESUMEN

In animals, differentiation of germline from soma usually takes place during embryogenesis. Genes and their products that are preferentially expressed in the embryonic germ cells are regarded as candidates for maintaining germline fate or promoting germline identity. In Drosophila, for example, the protein encoded by the germline gene vasa is specifically restricted to the germ cells, while products of the gap gene hunchback (hb), a somatic gene, are preferentially expressed in the neuroblasts. In this study, we report the expression of both messenger RNA and protein encoded by Aphb, an hb orthologue in the asexual viviparous pea aphid Acyrthosiphon pisum, in germ cells as well as in neuroblasts. We infer that expression of Aphb messenger RNA in the germ cells during the formation of germaria is required for the anterior localization of Aphb in the protruding oocytes. Germarial expression and anterior localization of ApKrüppel was also identified but, unlike Aphb, its expression was not detected in the migrating germ cells. Very similar patterns of hb expression were also identified in the green peach aphid Myzus persicae, suggesting that germline expression of hb is conserved within the Aphididae. To date, this pattern of hb germline expression has not been reported in other insects.


Asunto(s)
Áfidos/metabolismo , Células Germinativas/metabolismo , Proteínas de Insectos/metabolismo , Animales , Áfidos/embriología , Secuencia de Bases , Proteínas de Unión al ADN , Proteínas de Drosophila , Desarrollo Embrionario , Factores de Transcripción de Tipo Kruppel/metabolismo , Factores de Transcripción
4.
Eye (Lond) ; 31(11): 1569-1575, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-28622312

RESUMEN

AimsTo identify the clinical features and prognostic factors of endogenous endophthalmitis caused by Klebsiella pneumoniae.MethodsThis is a retrospective case series of all patients with Klebsiella endophthalmitis managed from January 2006 to December 2015 by Kowloon East Ophthalmic Service. Statistical analysis involved hypothesis testing on the SPSS 18.0 software (SPSS). A significance level of P<0.05 was taken.ResultsIn the 10-year period, K. pneumoniae accounted for 19 out of 39 cases of endogenous endophthalmitis (48.7%). The mean age of patients was 67.9 years. Bilateral involvement occurred in five patients (26.3%). More than half of the patients (10/19, 52.6%) had underlying diabetes mellitus. Most patients had concurrent liver abscess (18/19, 94.74%). Ten patients (52.6%) had disseminated intravascular coagulopathy. Eight patients (42.1%) were in shock. The overall mortality was 21.1% (4/19). Septic shock was associated with a significantly higher mortality (50.0 vs 0%, P=0.018). Among the 15 survivors, nine patients (60.0%) required evisceration and three patients (20.0%) had no light perception in an involved eye. Eyes with diffuse posterior involvement were less likely to have a final visual acuity of logMAR 0.30 or better than those with focal posterior involvement (4.76 vs 100% 4.76%, P=0.002). Patients with hypopyon were more likely to require evisceration (85.71 vs 25.00%, P=0.02).ConclusionsKlebsiella endophthalmitis is associated with a high incidence of diabetes mellitus and liver abscess. Prognosis remains poor. Universal ocular screening and systemic control in patients with Klebsiella sepsis are recommended.


Asunto(s)
Enfermedades Endémicas/estadística & datos numéricos , Endoftalmitis/epidemiología , Infecciones Bacterianas del Ojo/epidemiología , Predicción , Infecciones por Klebsiella/epidemiología , Klebsiella pneumoniae/aislamiento & purificación , Tamizaje Masivo/métodos , Anciano , Anciano de 80 o más Años , Antibacterianos/administración & dosificación , Endoftalmitis/tratamiento farmacológico , Endoftalmitis/microbiología , Infecciones Bacterianas del Ojo/tratamiento farmacológico , Infecciones Bacterianas del Ojo/microbiología , Femenino , Estudios de Seguimiento , Hong Kong/epidemiología , Humanos , Incidencia , Inyecciones Intravítreas , Infecciones por Klebsiella/tratamiento farmacológico , Infecciones por Klebsiella/microbiología , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos
5.
Eye (Lond) ; 31(9): 1373-1379, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28452991

RESUMEN

PurposeTo describe and correlate the morphological and clinical features of focal choroidal excavation (FCE).MethodsThis is a consecutive case series from the review of the 4436 optical coherence tomography scans performed by Kowloon East Cluster Ophthalmic Service from 1 August 2014-31 January 2016. Statistical analysis was performed on SPSS 18.0 (SPSS, Chicago, IL, USA). A significance level of P<0.05 was taken.ResultsAll 16 patients with FCE had unilateral involvement. The mean age of diagnosis was 52.56±14.00. The mean greatest linear dimension (GLD) of FCE was 636.25±265.11 µm. The mean choroidal thickness was 183.63±52.39 µm. Fourteen FCEs (87.5%) were conforming and two were non-conforming (12.5%). In the eyes with FCE, concurrent macular pathology was present in four cases (25.0%). Tractional pathologies of macular pucker and macular scar corresponded to the two non-conforming FCEs in the series. Polypoidal choroidal vasculopathy (PCV) and lacquer crack had a close topographic relationship with the FCE. The mean GLD was significantly larger in eyes with concurrent macular pathology than those without (878.00 vs 555.67 µm, P=0.029). In the fellow eyes, concurrent macular pathology was present in 5 cases (31.3%): PCV in 3 cases and chronic central serous chorioretinopathy in 2 cases.ConclusionAs a significant proportion of FCE is associated with concurrent macular pathology in the involved or fellow eye, angiography for both eyes is recommended even for asymptomatic cases. The GLD of FCE may have clinical value in risk stratification.


Asunto(s)
Enfermedades de la Coroides/patología , Coroides/patología , Adulto , Anciano , Coriorretinopatía Serosa Central/diagnóstico , Neovascularización Coroidal/diagnóstico , Femenino , Angiografía con Fluoresceína , Humanos , Degeneración Macular/diagnóstico , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Tomografía de Coherencia Óptica , Agudeza Visual/fisiología
6.
J Hand Surg Eur Vol ; 41(3): 340-5, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26115681

RESUMEN

This study was performed to measure the equivalent scattered radiation dose delivered to susceptible organs while simulating orthopaedic surgery using conventional and mini C-arm fluoroscopy. In addition, shielding effects on the thyroid, thymus, and gonad, and the direct exposure delivered to the patient's hands were also compared. A conventional and mini C-arms were installed in an operating room, and a hand and an operator phantom were used to simulate a patient's hand and a surgeon. Photoluminescence dosimeters were used to measure the equivalent dose by scattered radiation arriving at the thyroid, thymus, and gonad on a whole-body phantom in the position of the surgeon. Equivalent scattered radiation doses were measured in four groups: (1) unshielded conventional C-arm group; (2) unshielded mini C-arm group; (3) lead-shielded conventional C-arm group; and (4) lead-shielded mini C-arm group. Equivalent scattered radiation doses to the unshielded group were significantly lower in the mini C-arm group than those in the conventional C-arm group for all organs. The gonad in the lead-shielded conventional C-arm group showed the highest equivalent dose among operator-susceptible organs, and radiation dose was reduced by approximately 96% compared with that in the unshielded group. Scattered radiation was not detected in any susceptible organ in the lead-shielded mini C-arm group. The direct radiation dose to the hand phantom measured from the mini C-arm was significantly lower than that measured from the conventional C-arm. The results show that the equivalent scattered radiation dose to the surgeon's susceptible organs and the direct radiation dose to a patient's hand can be decreased significantly by using a mini C-arm rather than a conventional C-arm. However, protective lead garments, such as a thyroid shield and apron, should be applied to minimize radiation exposure to susceptible organs, even during use of mini C-arm fluoroscopy.


Asunto(s)
Fluoroscopía/instrumentación , Exposición Profesional , Ortopedia , Dosis de Radiación , Exposición a la Radiación , Radiación Ionizante , Gónadas , Humanos , Fantasmas de Imagen , Timo , Glándula Tiroides
7.
Biochem Biophys Res Commun ; 465(3): 613-9, 2015 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-26315268

RESUMEN

The localization of adenylyl cyclase A (ACA) to uropod of cells is required for the stream formation during Dictyostelium development. RacC is a Dictyostelium orthologue of Cdc42. We identified a streaming defect of racC(-) cells as they are clearly less polarized and form smaller and fragmented streams. ACA-YFP is mainly associated with intracellular vesicular structures, but not with the plasma membrane in racC(-) cells. racC(-) cells have a slightly higher number of vesicles than Ax3 cells, suggesting that the defect of ACA trafficking is not simply due to the lack of vesicle formation. While the ACA-YFP vesicles traveled with an average velocity of 9.1 µm/min in Ax3 cells, a slow and diffusional movement without direction with an average velocity of 4 µm/min was maintained in racC(-) cells. Images acquired by using total internal reflection fluorescence (TIRF) microscopy and fluorescence recovery after photobleaching (FRAP) analysis revealed that a significantly decreased number of ACA-YFP vesicles appeared near the cell membrane, indicating a defect in ACA-YFP vesicle trafficking. These results suggest an important role of RacC in the rapid and directional movements of ACA vesicles on microtubules to the plasma membrane, especially to the back of polarized cell.


Asunto(s)
Adenilil Ciclasas/metabolismo , Extensiones de la Superficie Celular/metabolismo , Dictyostelium/fisiología , Fracciones Subcelulares/enzimología , Proteína de Unión al GTP cdc42/metabolismo , Agregación Celular/fisiología , Transporte de Proteínas/fisiología
8.
Res Vet Sci ; 98: 74-81, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25440995

RESUMEN

Extensive use of current anti-coccidial drugs together with drug resistance and residue has raised concerns about public health and poultry development. Here, we studied the anti-coccidial properties of Bidens pilosa. A phytochemical approach was developed for analysis of B. pilosa utilized as a feed additive. The protective effects of B. pilosa supplemented chicken diet were evaluated chickens infected with Eimeria tenella. B. pilosa, at doses of 0.5%, 1% and 5% of the chicken diet, significantly protected against E.tenella as measured by reduction in mortality, weight loss, fecal oocyst excretion and gut pathology in chickens. Finally, drug resistance of E. tenella to B. pilosa was assessed in chickens using the anti-coccidial index. This index showed that B. pilosa induced little, if any, drug resistance to Eimeria in chickens. Collectively, this work suggests that B. pilosa may serve as a novel, natural remedy for coccidiosis with low drug resistance in chickens.


Asunto(s)
Bidens/química , Coccidiosis/veterinaria , Coccidiostáticos/uso terapéutico , Resistencia a Medicamentos/efectos de los fármacos , Eimeria tenella/fisiología , Extractos Vegetales/uso terapéutico , Enfermedades de las Aves de Corral/tratamiento farmacológico , Alimentación Animal/análisis , Animales , Pollos , Coccidiosis/tratamiento farmacológico , Coccidiosis/parasitología , Coccidiostáticos/administración & dosificación , Dieta/veterinaria , Suplementos Dietéticos/análisis , Relación Dosis-Respuesta a Droga , Extractos Vegetales/administración & dosificación , Enfermedades de las Aves de Corral/parasitología
9.
Osteoarthritis Cartilage ; 23(2): 232-8, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25450843

RESUMEN

OBJECTIVE: We sought to determine (1) whether change in the tibial plateau inclination (TPI) after high tibial osteotomy (HTO) is different from change in the knee joint line orientation (KJLO) relative to the ground; (2) whether, in varus knee OA patients before and after HTO, these radiographic measures are different from those in normal control; and (3) whether the postoperative values of the TPI and KJLO relative to the ground are associated with short term clinical outcome scores after HTO. DESIGN: Fifty patients who underwent HTO and 75 normal controls were assessed with four radiographic measures. We compared the measures before HTO with those after HTO and with those of the normal controls, then examined associations between the postoperative radiographic measures and clinical outcome scores 1-year after HTO. RESULTS: After HTO, TPI increased 9.0°, whereas KJLO relative to the ground only increased 4.1°, with a compensatory change of the ankle joint line orientation. However, the postoperative KJLO relative to the ground in the HTO group was significantly different from that of the normal controls (mean difference, 4.9°; P < 0.001). In the multiple regression analyses, the postoperative radiographic measures were not associated with outcome clinical scores 1 year after HTO. CONCLUSION: After HTO the relative KJLO changed significantly less than did the anatomical geometry of the proximal tibia. Although the KJLO after the HTO was still significantly different from that of normal knees, its value did not adversely affect clinical outcome scores 1 year after HTO.


Asunto(s)
Articulación del Tobillo/anatomía & histología , Articulación de la Rodilla/anatomía & histología , Osteoartritis de la Rodilla/cirugía , Osteotomía , Tibia/cirugía , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Osteotomía/métodos , Periodo Posoperatorio
10.
Chem Commun (Camb) ; 50(93): 14635-8, 2014 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-25313686

RESUMEN

CuCo2O4 nanoparticles have been synthesized by a simple and low-cost urea combustion method and characterized as bifunctional catalysts for non-aqueous Li-air batteries. The resulting CuCo2O4 catalyst has been demonstrated to effectively reduce the charge-discharge polarization of Li-air batteries in a simulated air environment (80% Ar : 20% O2).

11.
Clin Exp Immunol ; 178(3): 537-47, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25098704

RESUMEN

We investigated the impact of rice prolamin extract (RPE) on lipopolysaccharide (LPS)-induced nuclear factor (NF)-κB signalling in intestinal epithelial cells and macrophages, and determined the therapeutic efficacy of RPE in acute murine colitis. The effect of RPE on LPS-induced NF-κB signalling and proinflammatory gene expression was evaluated by reverse transcription-polymerase chain reaction (RT-PCR), Western blotting, immunofluorescence and electrophoretic mobility shift assay (EMSA). The in-vivo efficacy of RPE was assessed in mice with 3% dextran sulphate sodium (DSS)-induced colitis. Apoptotic and cellular proliferative activities were evaluated by immunostaining with cleaved caspase-3 and proliferating cell nuclear antigen (PCNA) antibodies. RPE inhibited LPS-induced expression of monocyte chemotactic protein (MCP)-1, interleukin (IL)-6 and tumour necrosis factor (TNF)-alpha and LPS-induced NF-κB signalling in intestinal epithelial cells and macrophages. RPE-fed, DSS-exposed mice showed less weight loss, longer colon length and lower histological score compared to control diet-fed, DSS-exposed mice. Immunostaining analysis revealed a significant decrease of cleaved caspase-3 positive cells in RPE-fed, DSS-exposed mice compared to DSS-exposed mice. Also, the number of PCNA-positive cells within intact colonic crypts decreased significantly in RPE-fed, DSS-exposed mice compared to control diet-fed, DSS-exposed mice. DSS-induced NF-κB signalling was inhibited by RPE. RPE ameliorates intestinal inflammation by inhibiting NF-κB activation and modulating intestinal apoptosis and cell proliferation in an acute murine colitis.


Asunto(s)
Apoptosis/efectos de los fármacos , Colitis/tratamiento farmacológico , Intestinos/efectos de los fármacos , FN-kappa B/antagonistas & inhibidores , Oryza/química , Extractos Vegetales/farmacología , Prolaminas/farmacología , Enfermedad Aguda , Animales , Proliferación Celular/efectos de los fármacos , Masculino , Ratones , Ratones Endogámicos C57BL , Extractos Vegetales/uso terapéutico
12.
Oncogene ; 33(22): 2898-908, 2014 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-23873025

RESUMEN

Melanoma cells facilitate endothelial gap formation, the first step during tumor transendothelial migration, which is mediated by both adhesion and endogenously produced chemokines (in particular, interleukin-8 (IL-8)). Tetraspanins are localized to the cell surface in cancer and participate in various functions including invasion of tissues mediated by secretion of cytokines and matrix metalloproteinases. However, little is known about the role of CD82 tetraspanins in malignant melanomas during cancer cell invasion. In this study, we investigated the functional importance of CD82 expression in melanoma-mediated gap formation by using cDNAs to induce CD82 expression in highly invasive melanoma cell lines. Results showed that CD82 expression inhibited melanoma cell-induced gap formation, melanoma cell extravasation in vitro and subsequent lung metastasis development in vivo. Mechanistic studies showed that inducible expression of CD82 in highly metastatic melanoma cells significantly increased p21 expression upon binding of Duffy antigen receptor group (DARC), inducing tumor cell senescence and interrupting IL-8-mediated vascular endothelial (VE)-cadherin disassembly. Taken together, these studies provide a rationale for using drug therapies that restore CD82 expression and inhibit IL-8 production to inhibit late-stage melanoma cell extravasation and subsequent metastasis development.


Asunto(s)
Células Endoteliales/metabolismo , Interleucina-8/metabolismo , Proteína Kangai-1/genética , Melanoma/genética , Melanoma/metabolismo , Adulto , Anciano , Animales , Sistema del Grupo Sanguíneo Duffy/metabolismo , Femenino , Expresión Génica , Células Endoteliales de la Vena Umbilical Humana/metabolismo , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundario , Masculino , Melanoma/patología , Ratones , Persona de Mediana Edad , Invasividad Neoplásica , Metástasis de la Neoplasia , Estadificación de Neoplasias , Unión Proteica , Receptores de Superficie Celular/metabolismo
13.
Lung Cancer ; 82(2): 276-81, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23992877

RESUMEN

BACKGROUND: Molecularly targeted agents for non-small cell lung cancer (NSCLC) can provide similar efficacy to chemotherapy without chemotherapy-associated toxicities. Combining two agents with different modes of action could further increase the efficacy of these therapies. The TASK study evaluated the efficacy and safety of the epidermal growth factor receptor tyrosine kinase inhibitor erlotinib in combination with the anti-angiogenic agent bevacizumab as first-line therapy in unselected, advanced non-squamous NSCLC patients. METHODS: Patients were recruited from December 2007 to September 2008. Planned sample size was 200 patients, a total of 124 patients were randomized. Patients were randomized using a minimization algorithm 1:1 to receive bevacizumab (iv 15 mg/kg day 1 of each 21-day cycle) plus chemotherapy (gemcitabine/cisplatin or carboplatin/paclitaxel standard doses, 4-6 cycles) (BC arm) or bevacizumab plus erlotinib (p.o. 150 mg/day; BE arm) until disease progression or unacceptable toxicity. The primary endpoint was progression-free survival (PFS). If the hazard ratio (HR) of PFS for BE relative to BC was above 1.25 at the pre-planned interim analysis in favor of BC, the study would be re-evaluated. Secondary endpoints included overall survival, response rate and safety. RESULTS: All randomized patients (n = 63 BE; n = 61 BC) were evaluated for the efficacy analyses. At the updated interim analysis, median PFS was 18.4 weeks (95% confidence interval [CI] 17.0-25.1) versus 25.0 weeks (95% CI 20.6-[not reached]) for BE versus BC, respectively (HR for death or disease progression, BE relative to BC, 2.05, p = 0.0183). The incidence of death was 19% for BE treatment compared with 11.5% for BC treatment. The HR for PFS at the updated interim analysis was above 1.25, therefore patients on the BE arm were permitted to change arms or switch to another drug and the study was terminated. Adverse events reported were as expected. CONCLUSIONS: The TASK study did not show a benefit in terms of PFS for the combination of erlotinib with bevacizumab in unselected first-line advanced non-squamous NSCLC compared with chemotherapy plus bevacizumab.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/patología , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Adulto , Anciano , Anticuerpos Monoclonales Humanizados/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bevacizumab , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Clorhidrato de Erlotinib , Femenino , Humanos , Neoplasias Pulmonares/mortalidad , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Quinazolinas/administración & dosificación , Factores de Riesgo , Resultado del Tratamiento
14.
Phys Chem Chem Phys ; 15(39): 16579-85, 2013 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-23959211

RESUMEN

Layered Li2MnO3·3LiNi0.5-xMn0.5-xCo2xO2 (x = 0, 0.05, 0.1, 0.165) microspheres with Mn-rich core were successfully synthesized by a simple two-step precipitation calcination method and intensively evaluated as cathode materials for lithium ion batteries. The X-ray powder diffractometry (XRD) results indicate that the growth of Li2MnO3-like regions is impeded due to the presence of cobalt (Co) in the material. The field-emission scanning electron microscopy (FESEM) data reveal the core-shell-like structure with a Mn-rich core in the as-prepared particles. The charge-discharge testing reveals that the capacity is markedly improved by adding Co. The activation of the cathode after Co doping becomes easier and can be accomplished completely when charged to 4.6 V at the C/40 rate in the initial cycle. Superior electrochemical performances are obtained for samples with x = 0.05 and 0.1. The corresponding initial discharge capacities are separately 281 and 285 mA h g(-1) at C/40 between 2 and 4.6 V at room temperature. After 250 cycles at C/2, the respective capacity retentions are 71.2% and 70.4%, which are better compared to the normal Li-excess Li2MnO3·3LiNi0.4Mn0.4Co0.2O2 sample with a uniform distribution of Mn element in the particles. The initial discharge capacities of both samples are approximately 250 mA h g(-1) at a rate of C/2 between 2 and 4.6 V at 55 °C after activation. Furthermore, the samples are investigated by electrochemical impedance spectroscopy (EIS) at room and elevated temperature, revealing that the key factor affecting electrochemical performance is the charge transfer resistance in the particles.

15.
ACS Appl Mater Interfaces ; 5(18): 8961-7, 2013 Sep 25.
Artículo en Inglés | MEDLINE | ID: mdl-23981067

RESUMEN

A microspherical, hollow LiFePO4 (LFP) cathode material with polycrystal structure was simply synthesized by a solvothermal method using spherical Li3PO4 as the self-sacrificed template and FeCl2·4H2O as the Fe(2+) source. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) show that the LFP micro hollow spheres have a quite uniform size of ~1 µm consisting of aggregated nanoparticles. The influences of solvent and Fe(2+) source on the phase and morphology of the final product were chiefly investigated, and a direct ion exchange reaction between spherical Li3PO4 templates and Fe(2+) ions was firstly proposed on the basis of the X-ray powder diffraction (XRD) transformation of the products. The LFP nanoparticles in the micro hollow spheres could finely coat a uniform carbon layer ~3.5 nm by a glucose solution impregnating-drying-sintering process. The electrochemical measurements show that the carbon coated LFP materials could exhibit high charge-discharge capacities of 158, 144, 125, 101, and even 72 mAh g(-1) at 0.1, 1, 5, 20, and 50 C, respectively. It could also maintain 80% of the initial discharge capacity after cycling for 2000 times at 20 C.


Asunto(s)
Suministros de Energía Eléctrica , Hierro/química , Litio/química , Fosfatos/química , Solventes/química , Carbono/química , Electrodos , Compuestos Ferrosos/química , Intercambio Iónico , Iones/química , Tamaño de la Partícula
16.
Nanoscale ; 5(19): 9101-9, 2013 Oct 07.
Artículo en Inglés | MEDLINE | ID: mdl-23904051

RESUMEN

Hierarchical assembly of Ti(IV)/Sn(II)-doped SnO2 nanosheets along titanate nanowires serving as both sacrificial templates and a Ti(IV) source is demonstrated, using SnCl2 as a tin precursor and Sn(II) dopants and NaF as the morphology controlling agent. Excess fluoride inhibits the hydrolysis of SnCl2, promoting heterogeneous nucleation of Sn(II)-doped SnO2 on the titanate nanowires due to the insufficient oxidization of Sn(II) to Sn(IV). Simultaneously, titanate nanowires are dissolved forming Ti(4+) species under the etching effect of in situ generated HF resulting in spontaneous Ti(4+) ion doping of SnO2 nanosheets formed under hydrothermal conditions. Compositional analysis indicates that Ti(4+) ions are incorporated by substitution of Sn sites at a high level (16-18 at.%), with uniform distribution and no phase separation. Mössbauer spectroscopy quantified the relative content of Sn(II) and Sn(IV) in both Sn(II)-doped and Ti(IV)/Sn(II) co-doped SnO2 samples. Electrochemical properties were investigated as an anode material in lithium ion batteries, demonstrating that Ti-doped SnO2 nanosheets show improved cycle performance, which is attributed to the alleviation of inherent volume expansion of the SnO2-based anode materials by substituting part of Sn sites with Ti dopants.

17.
Osteoporos Int ; 24(11): 2819-25, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-23681087

RESUMEN

UNLABELLED: We report the bone attenuation of ankle joint measured on computed tomography (CT) and the cause of injury in patients with ankle fractures. The results showed age- and gender-dependent low bone attenuation and low-energy trauma in elderly females, which suggest the osteoporotic features of ankle fractures. INTRODUCTION: This study was performed to investigate the osteoporotic features of ankle fracture in terms of bone attenuation and cause of injury. METHODS: One hundred ninety-four patients (mean age 51.0 years, standard deviation 15.8 years; 98 males and 96 females) with ankle fracture were included. All patients underwent CT examination, and causes of injury (high/low-energy trauma) were recorded. Mean bone attenuations of the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis were measured on CT images. Patients were divided into younger age (<50 years) and older age (≥50 years) groups, and mean bone attenuation and causes of injury were compared between the two groups in each gender. RESULTS: Proportion of low-energy trauma was higher in the older age group than in the younger age group, but the difference was only significant in female gender (p = 0.011). The older age group showed significantly lower bone attenuation in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis than the younger age group in both genders. The older age group showed more complex pattern of fractures than the younger age group. With increasing age, bone attenuations tended to decrease and the difference of bone attenuation between the genders tended to increase in the talus, medial malleolus, lateral malleolus, and distal tibial metaphysis. CONCLUSIONS: Ankle fracture had features of osteoporotic fracture that is characterized by age- and gender-dependent low bone attenuation. Ankle fracture should not be excluded from the clinical and research interest as well as from the benefit of osteoporosis management.


Asunto(s)
Fracturas de Tobillo , Articulación del Tobillo/diagnóstico por imagen , Fracturas Osteoporóticas/diagnóstico por imagen , Adulto , Factores de Edad , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Variaciones Dependientes del Observador , Fracturas Osteoporóticas/etiología , Reproducibilidad de los Resultados , Factores Sexuales , Astrágalo/diagnóstico por imagen , Tibia/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto Joven
18.
J Biomed Mater Res A ; 101(9): 2586-601, 2013 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-23401387

RESUMEN

The abraded debris might cause osteocytic osteolysis on the interface between implants and bone tissues, thus inducing the subsequent mobilization of implants gradually and finally resulting in the failure of bone implants, which imposes restrictions on the applications of porous NiTi shape memory alloys (SMAs) scaffolds for bone tissue engineering. In this work, the effects of the annealing temperature, applied load, and porosity on the tribological behavior and wear resistance of three-dimensional porous NiTi SMA are investigated systematically. The porous structure and phase transformation during the exothermic process affect the tribological properties and wear mechanism significantly. In general, a larger porosity leads to better tribological resistance but sometimes, SMAs with small porosity possess better wear resistance than ones with higher porosity during the initial sliding stage. It can be ascribed to the better superelasticity of the former at the test temperature. The porous NiTi phase during the exothermic reaction also plays an important role in the wear resistance. Generally, porous NiTi has smaller friction coefficients under high loads due to stress-induced superelasticity. The wear mechanism is discussed based on plastic deformation and microcrack propagation.


Asunto(s)
Huesos/cirugía , Níquel/química , Andamios del Tejido/química , Titanio/química , Materiales Biocompatibles/química , Análisis de Falla de Equipo , Dureza , Calor , Humanos , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Transición de Fase , Porosidad , Prótesis e Implantes , Estrés Mecánico , Propiedades de Superficie , Ingeniería de Tejidos
19.
Osteoporos Int ; 24(4): 1399-406, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23052930

RESUMEN

UNLABELLED: The 12-week home-based virtual cycling training (hVCT) improved lower limb muscle strength and areal bone mineral density (aBMD) than the control program in children with cerebral palsy (CP). A muscle strengthening program, rather than general physical activity, is more specific in enhancing aBMD for these children. A novel hVCT is an effective and efficient strategy that enhances lower limb bone density in these children. INTRODUCTION: This is the first study to assess the efficacy of a novel hVCT program on bone density for children with spastic CP using a well-designed randomized controlled trial. METHODS: Twenty-seven ambulatory children with spastic CP, aged 6-12 years, were randomly assigned to the hVCT group (n=13) or control group (n=14). Outcome measures-motor function [Gross Motor Function Measure-66 (GMFM-66)], muscle strength (curl up scores and isokinetic torque of knee extensor and flexor muscle) and aBMD of the lumbar and distal femur-were administered before and immediately after the 12-week intervention. RESULTS: Analysis of covariance results show that the hVCT group had greater distal femur aBMD and isokinetic torques of knee extensor and flexor muscles than the control group at posttreatment (p<0.05). However, curl up scores, GMFM-66, and lumbar aBMD at posttreatment did not differ between the two groups. CONCLUSIONS: Analytical findings suggest that the muscle strengthening program is more specific in enhancing bone density for children with CP than general physical activity. Thus, the proposed 12-week hVCT protocol is an effective and efficient strategy for improving lower limb aBMD in these children.


Asunto(s)
Ciclismo/fisiología , Densidad Ósea/fisiología , Parálisis Cerebral/rehabilitación , Terapia por Ejercicio/métodos , Servicios de Atención de Salud a Domicilio , Terapia de Exposición Mediante Realidad Virtual/métodos , Parálisis Cerebral/fisiopatología , Niño , Femenino , Fémur/fisiopatología , Humanos , Articulación de la Rodilla/fisiopatología , Masculino , Fuerza Muscular/fisiología , Músculo Esquelético/fisiopatología , Rango del Movimiento Articular/fisiología , Resultado del Tratamiento , Caminata/fisiología
20.
Lupus ; 21(14): 1582-5, 2012 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-23161579

RESUMEN

Neonatal lupus is a passively acquired autoimmune syndrome resulting from the transplacental passage of maternal anti-Ro/SSA and/or anti-La/SSB antibodies to the fetus. Few past studies have reported central nervous system involvement in neonatal lupus, and most cases had a good neurological outcome. We report here a preterm case of neonatal lupus with thrombocytopenia and comorbid hemorrhagic stroke. In the follow-up, the infant developed spastic quadriplegia and showed delayed milestones. We believe that this is the first reported case of neonatal lupus accompanied by perinatal hemorrhagic stroke. We present this case to remind clinicians to conduct regular central nervous system surveys in cases of neonatal lupus.


Asunto(s)
Hemorragia Cerebral/etiología , Lupus Eritematoso Sistémico/congénito , Accidente Cerebrovascular/etiología , Trombocitopenia/etiología , Hemorragia Cerebral/patología , Humanos , Recién Nacido , Lupus Eritematoso Sistémico/complicaciones , Masculino , Nacimiento Prematuro , Cuadriplejía/etiología , Accidente Cerebrovascular/patología
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