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1.
RSC Adv ; 14(37): 27132-27140, 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39193290

RESUMEN

Hydrogen production via cost-effective electrochemical water splitting is one of the most promising approaches to confront the energy crisis and to obtain clean fuels with high energy density. To address this concern, herein, we developed a simple one-step synthesis method for creating an AuAgCu trimetallic alloy using aspirin as a capping agent. This alloy shows potential for efficient electrocatalyst for hydrogen evolution reaction. The trimetallic nanoparticles based alloy exhibit an equiaxed grain-like morphology and a face-centred cubic phase. In HER experiments using a 1 M KOH electrolyte, the AuAgCu alloy shows nearly negligible overpotential compared to mono- and bimetallic catalysts, and the Tafel slope was 32.7 mV dec-1, which is the lowest ever achieved for alloy-based electrocatalysts and extremely close to a commercially available Pt/C with high stability for 21 days and no decrease in current density in alkaline media. Besides, with excellent HER activity and stability, the trimetallic AuAgCu-modified electrode possessed significant durability for over 1000 cycles in the selected range of potential from 0.5 to 0.8 V at different scan rates from 1 to 100 mV s-1. This simple, cost-effective and environmentally friendly methodology can pave the way for the exploitation of mixed metal alloy-based electrocatalysts not only for water splitting but also for other applications, such as fuel cells, lithium-ion batteries and supercapacitors.

2.
Nanoscale ; 16(33): 15419-15445, 2024 Aug 22.
Artículo en Inglés | MEDLINE | ID: mdl-39078286

RESUMEN

The excessive presence of airborne fungal spores presents major concerns with potential adverse impacts on public health and food safety. These spores are recognized as pathogens and allergens prevalent in both outdoor and indoor environments, particularly in public spaces such as hospitals, schools, offices and hotels. Indoor environments pose a heightened risk of pulmonary diseases due to continuous exposure to airborne fungal spore particles through constant inhalation, especially in those individuals with weakened immunity and immunocompromised conditions. Detection methods for airborne fungal spores are often expensive, time-consuming, and lack sensitivity, making them unsuitable for indoor/outdoor monitoring. However, the emergence of micro-nano biosensor systems offers promising solutions with miniaturized designs, nanomaterial integration, and microfluidic systems. This review provides a comprehensive overview of recent advancements in bio-nano-sensor system technology for detecting airborne fungal spores, while also discussing future trends in biosensor device development aimed at achieving rapid and selective identification of pathogenic airborne fungi.


Asunto(s)
Microbiología del Aire , Técnicas Biosensibles , Esporas Fúngicas , Técnicas Biosensibles/métodos , Esporas Fúngicas/aislamiento & purificación , Hongos/aislamiento & purificación , Humanos , Monitoreo del Ambiente/métodos , Nanoestructuras/química
3.
Mater Horiz ; 10(5): 1580-1607, 2023 05 09.
Artículo en Inglés | MEDLINE | ID: mdl-36880340

RESUMEN

Flexible and stretchable wearable electronic devices have received tremendous attention for their non-invasive and personal health monitoring applications. These devices have been fabricated by integrating flexible substrates and graphene nanostructures for non-invasive detection of physiological risk biomarkers from human bodily fluids, such as sweat, and monitoring of human physical motion tracking parameters. The extraordinary properties of graphene nanostructures in fully integrated wearable devices have enabled improved sensitivity, electronic readouts, signal conditioning and communication, energy harvesting from power sources through electrode design and patterning, and graphene surface modification or treatment. This review explores advances made toward the fabrication of graphene-interfaced wearable sensors, flexible and stretchable conductive graphene electrodes, as well as their potential applications in electrochemical sensors and field-effect-transistors (FETs) with special emphasis on monitoring sweat biomarkers, mainly in glucose-sensing applications. The review emphasizes flexible wearable sweat sensors and provides various approaches thus far employed for the fabrication of graphene-enabled conductive and stretchable micro-nano electrodes, such as photolithography, electron-beam evaporation, laser-induced graphene designing, ink printing, chemical-synthesis and graphene surface modification. It further explores existing graphene-interfaced flexible wearable electronic devices utilized for sweat glucose sensing, and their technological potential for non-invasive health monitoring applications.


Asunto(s)
Grafito , Sudor , Humanos , Comunicación , Conductividad Eléctrica , Glucosa
4.
Analyst ; 148(8): 1633-1652, 2023 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-36880521

RESUMEN

Semiconductor quantum dots (QDs) are a promising class of nanomaterials for developing new photoelectrodes and photoelectrochemistry systems for energy storage, transfer, and biosensing applications. These materials have unique electronic and photophysical properties and can be used as optical nanoprobes in displays, biosensors, imaging, optoelectronics, energy storage and energy harvesting. Researchers have recently been exploring the use of QDs in photoelectrochemical (PEC) sensors, which involve exciting a QD-interfaced photoactive material with a flashlight source and generating a photoelectrical current as an output signal. The simple surface properties of QDs also make them suitable for addressing issues related to sensitivity, miniaturization, and cost-effectiveness. This technology has the potential to replace current laboratory practices and equipment, such as spectrophotometers, used for testing sample absorption and emission. Semiconductor QD-based PEC sensors offer simple, fast, and easily miniaturized sensors for analyzing a variety of analytes. This review summarizes the various strategies for interfacing QD nanoarchitectures for PEC sensing, as well as their signal amplification. PEC sensing devices, particularly those used for the detection of disease biomarkers, biomolecules (glucose, dopamine), drugs, and various pathogens, have the potential to revolutionize the biomedical field. This review discusses the advantages of semiconductor QD-based PEC biosensors and their fabrication methods, with a focus on disease diagnostics and the detection of various biomolecules. Finally, the review provides prospects and considerations for QD-based photoelectrochemical sensor systems in terms of their sensitivity, speed, and portability for biomedical applications.


Asunto(s)
Nanoestructuras , Puntos Cuánticos , Técnicas Electroquímicas/métodos , Nanoestructuras/química , Puntos Cuánticos/química , Semiconductores , Propiedades de Superficie , Técnicas Biosensibles
5.
J Surg Case Rep ; 2023(1): rjad002, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36727122

RESUMEN

Primary meningeal melanocytomas are extremely rare, benign tumours arising from the leptomeninges. While they are considered to be benign lesions, there is potential for their growth and transformation into malignant melanomas. They are commonly found in the cervical spine, with a decreased incidence in the thoracic and lumbar regions. We present a case report of a 56-year-old man who presented to our unit with a 4-month history of lower limb weakness and a sensory level at T6. Magnetic resonance imaging shows an intradural extramedullary tumour. The patient underwent a thoracic debulking of the lesion with neurophysiological monitoring. Histopathology confirmed the diagnosis of melanocytoma of meningeal origin, with a low mitotic count. Our patient recovered well post-operatively with no complications. Surgical resection is an effective method to manage this tumour; however, adjuvant radiotherapy is advised due to the risk of recurrence and malignant transformation.

6.
Chemosphere ; 322: 138149, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36804630

RESUMEN

Sustainable fabrication of flexible hybrid supercapacitor electrodes is extensively investigated during the current era to solve global energy problems. Herein, we used a cost-effective and efficient electrophoretic deposition (EPD) approach to fabricate a hybrid supercapacitor electrode. ZnO/CuO and ZnO/CuO/rGO heterostructure were prepared by sol-gel synthesis route and were electrophoretically deposited on indium tin oxide (ITO) substrate as a thin uniform layer using 1 V for 20 min at 50 mV/s. ZnO/CuO and ZnO/CuO/rGO heterostructure coated ITOs were then employed as the working electrode in a three-electrode setup for supercapacitor measurements. The fabricated electrodes have been investigated by Galvanostatic charge-discharge (GCD), electrochemical impedance spectroscopy (EIS), and cyclic voltammetry (CV) to study their charge storage properties. ZnO/CuO revealed a specific capacitance of 1945 F g-1 at 2 mV/s and 999 F g-1 at 5 A g-1. However, an increased specific capacitance of 2305 F g-1 was measured for ZnO/CuO/rGO heterostructure at 2 mV/s and 1235 F g-1 at 5 A g-1. The lower internal resistance was observed for ZnO/CuO/rGO heterostructure, indicating good conductivity of the electrode material. Thus, the overall results of the current study suggest that EPD-assisted ZnO/CuO/rGO heterostructure hybrid electrode possess a substantial potential for energy storage as a supercapacitor.


Asunto(s)
Óxido de Zinc , Cobre , Electrodos
7.
RSC Adv ; 12(54): 35409-35417, 2022 Dec 06.
Artículo en Inglés | MEDLINE | ID: mdl-36540222

RESUMEN

Sustainable and effective electrochemical materials for supercapacitors are greatly needed for solving the global problems of energy storage. In this regard, a facile nanocomposite of Pd/NiOPdO was synthesized using foliar phyto eco-friendly agents and examined as an electrochemical electrode active material for supercapacitor application. The nanocomposite showed a mixed phase of a ternary nano metal oxide phase of rhombohedral NiO and tetragonal PdO confirmed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and XPS (X-rays photoelectron spectroscopy). The optical (direct) energy value of the synthesized nanocomposite was 3.14 eV. The phyto-functionalized nanocomposite was studied for electrochemical supercapacitor properties and revealed a specific capacitance of 88 F g-1 and low internal resistance of 0.8 Ω. The nanoscale and phyto organic species functionalized nanocomposite exhibited enhanced electrochemical properties for supercapacitor application.

8.
Mater Sci Eng C Mater Biol Appl ; 129: 112356, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34579878

RESUMEN

Recent COVID-19 pandemic has claimed millions of lives due to lack of a rapid diagnostic tool. Global scientific community is now making joint efforts on developing rapid and accurate diagnostic tools for early detection of viral infections to preventing future outbreaks. Conventional diagnostic methods for virus detection are expensive and time consuming. There is an immediate requirement for a sensitive, reliable, rapid and easy-to-use Point-of-Care (PoC) diagnostic technology. Electrochemical biosensors have the potential to fulfill these requirements, but they are less sensitive for sensing viruses/viral infections. However, sensitivity and performance of these electrochemical platforms can be improved by integrating carbon nanostructure, such as graphene and carbon nanotubes (CNTs). These nanostructures offer excellent electrical property, biocompatibility, chemical stability, mechanical strength and, large surface area that are most desired in developing PoC diagnostic tools for detecting viral infections with speed, sensitivity, and cost-effectiveness. This review summarizes recent advancements made toward integrating graphene/CNTs nanostructures and their surface modifications useful for developing new generation of electrochemical nanobiosensors for detecting viral infections. The review also provides prospects and considerations for extending the graphene/CNTs based electrochemical transducers into portable and wearable PoC tools that can be useful in preventing future outbreaks and pandemics.


Asunto(s)
Técnicas Biosensibles , COVID-19 , Grafito , Nanotubos de Carbono , Virus , Humanos , Pandemias , SARS-CoV-2
9.
Analyst ; 145(24): 7825-7848, 2021 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-33111714

RESUMEN

Viral and bacterial infections commonly occur by their transmission through air, contaminated food, water, body fluids or physical contact from person to person. They rapidly spread among the population causing millions of deaths worldwide. One of the major challenges in the diagnosis of infection is differential diagnosis of viral from bacterial infections. Constant viral mutations, reassortment and recombination give rise to the emergence of new and diverse viral populations which makes the diagnosis difficult. Antibiotics prescribed for patients suffering from viral infections are ineffective and a contributing factor to bacterial antibiotic resistance. Evaluating the existing biosensing platforms for early diagnosis of the bacterial etiology of infections enables researchers and clinicians to differentially diagnose viral infections. Over the last decade, many biosensors have been developed to detect a wide range of bacterial and viral markers and reduce the costs for healthcare. There has been considerable interest in finding diagnostic and prognostic biomarkers that can be detected in blood and predict bacterial and viral infections. This review provides an overview on the existing biosensor technology platforms for host biomarker detection that can be applied for differential diagnosis of viral and bacterial infections, as well as recommended considerations and future prospects of viral/bacterial infection detection technology.


Asunto(s)
Infecciones Bacterianas , Técnicas Biosensibles , Antibacterianos , Infecciones Bacterianas/diagnóstico , Infecciones Bacterianas/tratamiento farmacológico , Biomarcadores , Farmacorresistencia Bacteriana , Humanos
10.
Mater Sci Eng C Mater Biol Appl ; 118: 111545, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33255097

RESUMEN

Combination of quantum dots (QDs) and magnetic nanoparticles (MNPs) as magnetic quantum dots (MQDs) has a broad range of applications as multifunctional nanoscale devices in biological imaging, medical nano-diagnostics and nanomedicine. MQDs derived from iron oxide nanoparticles and QDs possess excellent superparamagnetic and fluorescent properties, respectively making them multifunctional nanoprobes because of their; (a) strong magnetic strength with tunable functionality, such as rapid and simple magnetic separation, (b) intense and stable fluorescence from QDs combined with tunable biological functionality upon QDs' bio-activation, and (c) imaging/visualization by simple ultraviolet light exposure. These excellent features of MQD nanoprobes enable them to be used for magnetic resonance imaging (MRI) as contrast agents, nano-diagnostic systems for Point-of-Care (PoC) disease diagnosis, theranostics nanorobots and in other bio-medical applications. Most of MQDs are derived from iron based MNPs because of their abundancy, superparamagnetic properties, low cost and easy to synthesize. In this review, we present different methods employed for chemical synthesis of MQDs derived from iron oxide MNPs, their major chemical compositions and important parameters, such as precursor compositions, quantum yield and magnetic properties. The review also summarizes the most frequently used MQDs in applications such as bio-imaging, drug delivery, biosensor platforms and finally ends with future prospects and considerations for MQDs in biomedical applications.


Asunto(s)
Nanopartículas , Puntos Cuánticos , Nanopartículas Magnéticas de Óxido de Hierro , Magnetismo , Nanomedicina
11.
IEEE Trans Biomed Circuits Syst ; 12(6): 1440-1449, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-30605085

RESUMEN

This paper presents a hand-held point-of-care device that incorporates a lab-on-a-chip module with interdigitated capacitive biosensors for label-free detection of multiple cancer and cardiovascular disease biomarkers. The developed prototype is comprised of a cartridge incorporating capacitive biodetection sensors, a sensitive capacitive readout electronics enclosed in a hand-held unit, and data analysis software calculating the concentration of biomarkers using previously stored reference database. The capacitive biodetection sensors are made of interdigitated circular electrodes, which are preactivated with single (for detecting one biomarker) or multiple specific antibodies (for detecting multiple disease biomarkers). Detection principle of capacitive biosensor is based on measuring the level of capacitance change between interdigitated electrode pairs induced by the change in dielectric constant due to affinity-based electron exchange in between antibodies/antigens and electrodes. The more antibody-antigens binding occurs, the more capacitance change is measured due to the change in dielectric constant of the capacitance media. The device uses preactivated ready-to-use cartridges embedded with capacitive biosensors with shelf-life of three months under optimal conditions, and is capable of onsite diagnosis and can report the result in less than 30 min. The device is verified with real patient blood samples for six different disease biomarkers.


Asunto(s)
Biomarcadores/sangre , Técnicas Biosensibles/instrumentación , Cardiopatías/diagnóstico , Neoplasias/diagnóstico , Sistemas de Atención de Punto , Biomarcadores de Tumor/sangre , Bases de Datos Factuales , Diseño de Equipo , Humanos , Dispositivos Laboratorio en un Chip
12.
Ann Med Surg (Lond) ; 17: 22-26, 2017 May.
Artículo en Inglés | MEDLINE | ID: mdl-28392913

RESUMEN

INTRODUCTION: There are two main choices of anti-coagulation in cerebral venous thrombosis: Unfractionated heparin versus low molecular weight heparin. A consensus is yet to be reached regarding which agent is optimal. Therefore the aim of this systematic review and meta-analysis was to identify which agent is most effective in treating CVT. METHODS: Databases Pubmed (MEDLINE), Google Scholar and hand-picked references from papers of interest were reviewed. Studies comparing the use of low molecular weight heparin and unfractionated heparin in adult patients with a confirmed diagnosis of cerebral vein thrombosis were selected. Data was recorded for patient mortality, functional outcome and haemorrhagic complications of therapy. RESULTS: A total of 2761 papers were identified, 74 abstracts were screened, with 5 papers being read in full text and three studies suitable for final inclusion. A total of 179 patients were in the LMWH group and 352 patients were in the UH group. Mortality and functional outcome trended towards favouring LMWH with OR [95% CI] of 0.51 [0.23, 1.10], p = 0.09 and 0.79 [0.49, 1.26] p = 0.32 respectively. There was no difference in extra-cranial haemorrhage rates between either agent with a OR [95% CI] of 1.00 [0.29, 3.52] p = 0.99. CONCLUSION: Trends towards improved mortality and improved functional outcomes were seen in patients treated with LMWH. No result reached statistical significance due to low numbers of studies available for inclusion. There is a need for further large scale randomized trials to definitively investigate the potential benefits of LMWH in the treatment of CVT.

13.
Biosens Bioelectron ; 90: 53-60, 2017 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-27875752

RESUMEN

Electronic-cigarettes (e-cigarette) are widely used as an alternative to traditional cigarettes but their safety is not well established. Herein, we demonstrate and validate an analytical method to discriminate the deleterious effects of e-cigarette refills (e-juice) and soluble e-juice aerosol (SEA) by employing stress-specific bioluminescent recombinant bacterial cells (RBCs) as whole-cell biosensors. These RBCs carry luxCDABE-operon tightly controlled by promoters that specifically induced to DNA damage (recA), superoxide radicals (sodA), heavy metals (copA) and membrane damage (oprF). The responses of the RBCs following exposure to various concentrations of e-juice/SEA was recorded in real-time that showed dose-dependent stress specific-responses against both the e-juice and vaporized e-juice aerosols produced by the e-cigarette. We also established that high doses of e-juice (4-folds diluted) lead to cell death by repressing the cellular machinery responsible for repairing DNA-damage, superoxide toxicity, ion homeostasis and membrane damage. SEA also caused the cellular damages but the cells showed enhanced bioluminescence expression without significant growth inhibition, indicating that the cells activated their global defense system to repair these damages. DNA fragmentation assay also revealed the disintegration of total cellular DNA at sub-toxic doses of e-juice. Despite their state of matter, the e-juice and its aerosols induce cytotoxicity and alter normal cellular functions, respectively that raises concerns on use of e-cigarettes as alternative to traditional cigarette. The ability of RBCs in detecting both harmful effects and toxicity mechanisms provided a fundamental understanding of biological response to e-juice and aerosols.


Asunto(s)
Bacterias/efectos de los fármacos , Técnicas Biosensibles , Daño del ADN/efectos de los fármacos , Sistemas Electrónicos de Liberación de Nicotina/efectos adversos , Aerosoles/química , Bacterias/genética , Proteínas Bacterianas/genética , ADN Recombinante/química , ADN Recombinante/genética , Humanos , Oxidorreductasas/genética , Rec A Recombinasas/genética
14.
Biosens Bioelectron ; 91: 225-231, 2017 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-28012318

RESUMEN

E. coli O157:H7 is an enterohemorrhagic bacteria responsible for serious foodborne outbreaks that causes diarrhoea, fever and vomiting in humans. Recent foodborne E. coli outbreaks has left a serious concern to public health. Therefore, there is an increasing demand for a simple, rapid and sensitive method for pathogen detection in contaminated foods. In this study, we developed a label-free electrical biosensor interfaced with graphene for sensitive detection of pathogenic bacteria. This biosensor was fabricated by interfacing graphene with interdigitated microelectrodes of capacitors that were biofunctionalized with E. coli O157:H7 specific antibodies for sensitive pathogenic bacteria detection. Here, graphene nanostructures on the sensor surface provided superior chemical properties such as high carrier mobility and biocompatibility with antibodies and bacteria. The sensors transduced the signal based on changes in dielectric properties (capacitance) through (i) polarization of captured cell-surface charges, (ii) cells' internal bioactivity, (iii) cell-wall's electronegativity or dipole moment and their relaxation and (iv) charge carrier mobility of graphene that modulated the electrical properties once the pathogenic E. coli O157:H7 captured on the sensor surface. Sensitive capacitance changes thus observed with graphene based capacitors were specific to E. coli O157:H7 strain with a sensitivity as low as 10-100 cells/ml. The proposed graphene based electrical biosensor provided advantages of speed, sensitivity, specificity and in-situ bacterial detection with no chemical mediators, represents a versatile approach for detection of a wide variety of other pathogens.


Asunto(s)
Técnicas Biosensibles/instrumentación , Infecciones por Escherichia coli/microbiología , Escherichia coli O157/aislamiento & purificación , Grafito/química , Dispositivos Laboratorio en un Chip , Nanoestructuras/química , Anticuerpos Inmovilizados/química , Diseño de Equipo , Contaminación de Alimentos/análisis , Microbiología de Alimentos , Enfermedades Transmitidas por los Alimentos/microbiología , Humanos , Límite de Detección , Microelectrodos , Nanoestructuras/ultraestructura
15.
Colloids Surf B Biointerfaces ; 146: 39-46, 2016 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-27248463

RESUMEN

In this study, soil bacteria were isolated from nanomaterials (NMs) contaminated pond soil and enriched in the presence of graphene oxide (GO) in mineral medium to obtain NMs resistant bacteria. The isolated resistant bacteria were biochemically and genetically identified as Fontibacillus aquaticus. The resistant bacteria were allowed to interact with engineered GO in order to study the biotransformation in GO structure. Raman spectra of GO extracted from culture medium revealed decreased intensity ratio of ID/IG with subsequent reduction of CO which was consistent with Fourier transform infrared (FTIR) results. The structural changes and exfoliatied GO nanosheets were also evident from transmission electron microscopy (TEM) images. Ultraviolet-visible spectroscopy, high resolution X-ray diffraction (XRD) and current-voltage measurements confirmed the reduction of GO after the interaction with resistant bacteria. X-ray photoelectron spectroscopy (XPS) analysis of biotransformed GO revealed reduction of oxygen-containing species on the surface of nanosheets. Our results demonstrated that the presented method is an environment friendly, cost effective, simple and based on green approaches for the reduction of GO using NMs resistant bacteria.


Asunto(s)
Grafito/química , Nanoestructuras/química , Óxidos/química , Paenibacillus/química , Biodegradación Ambiental , Microscopía Electrónica de Transmisión , Espectroscopía de Fotoelectrones , Microbiología del Suelo , Espectroscopía Infrarroja por Transformada de Fourier , Espectrometría Raman , Difracción de Rayos X
16.
Biosens Bioelectron ; 69: 26-33, 2015 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-25703725

RESUMEN

In this study, we surface engineered living S. cerevisiae cells by decorating quantum dots (QDs) and traced the fate of QDs on molecular landscape of single mother cell through several generation times (progeny cells). The fate of QDs on cell-surface was tracked through the cellular division events using confocal microscopy and fluorescence emission profiles. The extent of cell-surface QDs distribution among the offspring was determined as the mother cell divides into daughter cells. Fluorescence emission from QDs on progeny cells was persistent through the second-generation time (~240min) until all of the progeny cells lost their cell-bound QDs during the third generation time (~360min). The surface engineered yeast cells were unaffected by the QDs present on their molecular landscapes and retained their normal cellular growth, architecture and metabolic activities as confirmed by their viability, scanning electron microscopy (SEM) examinations and cytotoxicity tests, respectively. Our results demonstrated that QDs on mother cell landscape tend to distribute among its progeny cells that accompanied with concomitant reduction in QDs' fluorescence, which can be quantified. We suggest that surface engineered cells with QDs will enable investigating the cellular behavior and monitoring cell growth patterns as nanobiosensors for screening of drugs/chemicals at single cell level with fewer side effects.


Asunto(s)
Microscopía Fluorescente/métodos , Saccharomyces cerevisiae/química , Saccharomyces cerevisiae/citología , Fracciones Subcelulares/química , División Celular , Fracciones Subcelulares/ultraestructura
17.
Br J Neurosurg ; 29(3): 358-61, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-25470243

RESUMEN

OBJECT: To investigate what benefits can be derived from a shorter construct length in the pedicle screw based surgical treatment of thoracolumbar burst fracture (TLBF). METHODS: A retrospective analysis was performed of clinical notes and radiology for patients who underwent surgical fixation of TLBFs between 2007 and 2012 in a single UK institution. Constructs either fixed the vertebra above the fracture to the vertebra below (short segment fixation - SSF) or fixed the vertebra above to the relatively well-preserved pedicles and inferolateral portions of the bodies of the fractured vertebra (mono-segment fixation - MSF). 11 patients in each group were included and length of operation, postoperative opiate use, time to mobilisation and length of hospital stay were recorded. Anterior vertebral height loss (AVHL) was measured from sagittal reconstructions of CT imaging and lateral radiographs. RESULTS: The mean operation time was 169 ± 10.4 min in the MSF group compared to 227 ± 13.3 minin the SSF group (p = 0.0028). Mean postoperative opiate use was 50.4 ± 17.9 mg in the MSF group compared to 126.6 ± 64.6 mgs in the SSF group (p = 0.3088, ns). Mean time to mobilisation was 1.3 ± 0.2 in the MSF group and 3.4 ± 1.3 in the SSF group (p = 0.1031, ns). There were no significant differences in progression of anterior vertebral height loss or hospital stay between the two groups. CONCLUSIONS: MSF for TLBFs is associated with shorter operative times than SSF. Strong trends are also demonstrated to quicker mobilisation, and lower opiate use. These advantages of a shorter construct length may result in cost saving and echo the advantages claimed by others for reducing spinal exposure in minimally invasive spinal surgery.


Asunto(s)
Tornillos Óseos , Vértebras Lumbares/cirugía , Fracturas de la Columna Vertebral/cirugía , Vértebras Torácicas/cirugía , Adulto , Anciano , Humanos , Persona de Mediana Edad , Tempo Operativo , Periodo Posoperatorio , Estudios Retrospectivos , Resultado del Tratamiento
18.
Analyst ; 140(1): 243-9, 2015 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-25365825

RESUMEN

A new in vitro assay was developed to detect human epidermal growth factor receptor 2 (HER2) protein, based on affinity dissociation of carbon nanotube (CNT)-wrapped anti-HER2 ssDNA aptamers. First, we selected an anti-HER2 ssDNA aptamer (H2) using an in vitro serial evolution of ligands by an exponential enrichment (SELEX) process. Then the fluorescently labelled H2 ssDNAs were tightly packed on CNTs that had previously been coupled with magnetic microbeads (MBs), forming MB-CNT-H2 hybrids. The loading capacity of these MB-CNTs heterostructures (2.8 × 10(8)) was determined to be 0.025 to 3.125 µM of H2. HER2 protein-induced H2 dissociation occurred from MB-CNT-H2 hybrids, which was specifically induced by the target HER2 protein, with a dissociation constant (Kd) of 270 nM. The stoichiometric affinity dissociation ratio with respect to H2-to-HER2 protein was shown to be approximately 1 : 1. Our results demonstrated that the developed assay can be an effective approach in detecting native forms of disease biomarkers in free solutions or in biological samples, for accurate diagnosis.


Asunto(s)
Aptámeros de Nucleótidos/química , ADN de Cadena Simple/química , Nanotubos de Carbono/química , Receptor ErbB-2/análisis , Humanos
19.
Biosens Bioelectron ; 67: 100-6, 2015 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-25088079

RESUMEN

Despite intensive studies on examining the toxicity of nanomaterials (NMs), our current understanding on potential toxicity in relation to size and cellular responses has remained limited. In this work, we have developed a whole-cell based capacitive biosensor (WCB) to determine the biological toxicity of nanoparticles (NPs) using iron oxide (Fe3O4) NPs as models. This WCB chip comprised of an array of capacitor sensors made of gold interdigitated microelectrodes on which living Escherichia coli cells were immobilized. Cells-on-chip was then allowed to interact with different sizes of Fe3O4 NPs (5, 20 and 100 nm) and concentration-depended cellular-responses were measured in terms of change in dielectric properties (capacitance) as a function of applied AC frequency. The WCB response showed smaller-sized Fe3O4 NPs (5 nm) induced maximum change in surface capacitance because of their effective cellular interaction with E. coli cells-on-chip indicating that the cells suffered from severe cellular deformation, which was confirmed by scanning electron microscopic (SEM) examination. Further our results were validated through their cell viability and E. coli responses at the interface of cell-membrane and NPs as a proof-of-concept. WCB response showed a size-dependent shift in maximum response level from 2 µg/ml of 5 nm sized NPs to 4 µg/ml with NP-sizes greater than 20 nm. The developed WCB offered real-time, label-free and noninvasive detection of cellular responses against Fe3O4 NPs' toxicity with speed, simplicity and sensitivity that can be extended to toxicity screening of various other NPs.


Asunto(s)
Técnicas Biosensibles , Supervivencia Celular/efectos de los fármacos , Compuestos Férricos/toxicidad , Nanopartículas/toxicidad , Escherichia coli/efectos de los fármacos , Oro/química , Microscopía Electrónica de Rastreo , Tamaño de la Partícula
20.
Br J Neurosurg ; 28(3): 347-50, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24111709

RESUMEN

OBJECTIVE: In the UK approximately 4000 patients are diagnosed with brain tumours each year. Many patients undergo CT scans of the chest, abdomen and pelvis as part of the investigation of such tumours. We aimed to determine the value of CT body scans in patients with newly diagnosed brain tumours. METHODS: We retrospectively reviewed the minutes of our neuro-oncology multidisciplinary team (MDT) meetings over a 12-month period to identify patients with a new radiological diagnosis of a brain tumour. Patients were divided into groups based on radiological diagnosis. Histology results were obtained for patients who underwent surgery. Results of CT body scans were obtained. RESULTS: A total of 261 patients were identified. Sixty percent had radiological primary brain tumours and 40% had secondary brain tumours. Concordance between radiological and histological diagnoses was high (97% for radiological primary brain tumours, and 83% for radiological secondary brain tumours). CT body scans demonstrated primary lesions in 90% of radiological secondary brain tumours. Thirty-four percent of patients with a radiological diagnosis of primary brain tumour underwent CT body scans. The majority of these scans were normal (78%). CONCLUSION: The ability of a specialist neuro-oncology MDT to correctly identify primary and secondary brain tumours on initial imaging is high. If the radiological diagnosis is of a secondary brain tumour, then CT body scans are essential. If the radiological diagnosis is of a primary brain tumour, then CT scans of the body are likely to add little to patient management.


Asunto(s)
Neoplasias Encefálicas/diagnóstico por imagen , Imagen de Cuerpo Entero/métodos , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias Encefálicas/patología , Neoplasias Encefálicas/cirugía , Estudios de Cohortes , Femenino , Glioblastoma/diagnóstico por imagen , Glioblastoma/patología , Glioblastoma/cirugía , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia/diagnóstico por imagen , Metástasis de la Neoplasia/patología , Valor Predictivo de las Pruebas , Estudios Retrospectivos , Tomografía Computarizada por Rayos X , Adulto Joven
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