Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 8 de 8
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
ACS Appl Bio Mater ; 7(5): 3143-3153, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38662615

RESUMO

Novel and flexible disposable laser-induced graphene (LIG) sensors modified with graphene conductive inks have been developed for dopamine and interleukin-6 (IL-6) detection. The LIG sensors exhibit high reproducibility (relative standard deviation, RSD = 0.76%, N = 5) and stability (RSD = 4.39%, N = 15) after multiple bendings, making the sensors ideal for wearable and stretchable bioelectronics applications. We have developed electrode coatings based on graphene conductive inks, poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (G-PEDOT:PSS) and polyaniline (G-PANI), for working electrode modification to improve the sensitivity and limit of detection (LOD). The selectivity of LIG sensors modified with the G-PANI ink is 41.47 times higher than that of the screen-printed electrode with the G-PANI ink modification. We have compared our fabricated bare laser-engraved Kapton sensor (LIG) with the LIG sensors modified with G-PEDOT (LIG/G-PEDOT) and G-PANI (LIG/G-PANI) conductive inks. We have further compared the performance of the fabricated electrodes with commercially available screen-printed electrodes (SPEs) and screen-printed electrodes modified with G-PEDOT:PSS (SPE/G-PEDOT:PSS) and G-PANI (SPE/G-PANI). SPE/G-PANI has a lower LOD of 0.632 µM compared to SPE/G-PEDOT:PSS (0.867 µM) and SPE/G-PANI (1.974 µM). The lowest LOD of the LIG/G-PANI sensor (0.4084 µM, S/N = 3) suggests that it can be a great alternative to measure dopamine levels in a physiological medium. Additionally, the LIG/G-PANI electrode has excellent LOD (2.6234 pg/mL) to detect IL-6. Also, the sensor is successfully able to detect ascorbic acid (AA), dopamine (DA), and uric acid (UA) in their ternary mixture. The differential pulse voltammetry (DPV) result shows peak potential separation of 229, 294, and 523 mV for AA-DA, DA-UA, and UA-AA, respectively.


Assuntos
Dopamina , Eletrodos , Grafite , Tinta , Lasers , Teste de Materiais , Nanocompostos , Grafite/química , Dopamina/análise , Nanocompostos/química , Humanos , Interleucina-6/análise , Técnicas Biossensoriais/instrumentação , Tamanho da Partícula , Imunoensaio/instrumentação , Técnicas Eletroquímicas/instrumentação , Materiais Biocompatíveis/química
2.
Micromachines (Basel) ; 15(4)2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38675286

RESUMO

Implantable biosensors have evolved to the cutting-edge technology of personalized health care and provide promise for future directions in precision medicine. This is the reason why these devices stand to revolutionize our approach to health and disease management and offer insights into our bodily functions in ways that have never been possible before. This review article tries to delve into the important developments, new materials, and multifarious applications of these biosensors, along with a frank discussion on the challenges that the devices will face in their clinical deployment. In addition, techniques that have been employed for the improvement of the sensitivity and specificity of the biosensors alike are focused on in this article, like new biomarkers and advanced computational and data communicational models. A significant challenge of miniaturized in situ implants is that they need to be removed after serving their purpose. Surgical expulsion provokes discomfort to patients, potentially leading to post-operative complications. Therefore, the biodegradability of implants is an alternative method for removal through natural biological processes. This includes biocompatible materials to develop sensors that remain in the body over longer periods with a much-reduced immune response and better device longevity. However, the biodegradability of implantable sensors is still in its infancy compared to conventional non-biodegradable ones. Sensor design, morphology, fabrication, power, electronics, and data transmission all play a pivotal role in developing medically approved implantable biodegradable biosensors. Advanced material science and nanotechnology extended the capacity of different research groups to implement novel courses of action to design implantable and biodegradable sensor components. But the actualization of such potential for the transformative nature of the health sector, in the first place, will have to surmount the challenges related to biofouling, managing power, guaranteeing data security, and meeting today's rules and regulations. Solving these problems will, therefore, not only enhance the performance and reliability of implantable biodegradable biosensors but also facilitate the translation of laboratory development into clinics, serving patients worldwide in their better disease management and personalized therapeutic interventions.

3.
Obes Surg ; 33(4): 1040-1048, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36708467

RESUMO

PURPOSE: There are very few studies that have compared the short-term outcomes of laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG). Among short-term outcomes, hospital readmission after these procedures is an area for quality enhancement and cost reduction. In this study, we compared 30-day readmission rates after LSG and LRYGB through analyzing a nationalized dataset. In addition, we identified the reasons of readmission. MATERIALS AND METHODS: The current study was a retrospective analysis of data from National Surgical Quality Improvement Program (NSQIP) All adult patients, ≥ 18 years of age and who had LSG or LRYGB during 2014 to 2019 were included. Current Procedural Terminology (CPT) codes were used to identify the procedures. Multivariate logistic regressions were used to calculate propensity score adjusted odds ratios (ORs) for all cause 30-day re-admissions. RESULTS: There were 109,900 patients who underwent laparoscopic bariatric surgeries (67.5% LSG and 32.5% LRYGB). Readmissions were reported in 4168 (3.8%) of the patients and were more common among RYGB recipients compared to LSG (5.6% versus 2.9%, P < 0.001). The odds of 30-day readmissions were significantly higher among LRYGB group compared to LSG group (AOR, 2.20; 95% CI; 1.83, 2.64). In addition, variables such as age, chronic obstructive pulmonary disease, hypertension, bleeding disorders, blood urea nitrogen, SGOT, alkaline phosphatase, hematocrit, and operation time were significantly predicting readmission rates. CONCLUSIONS: Readmission rates were significantly higher among those receiving LRYGB, compared to LSG. Readmission was also affected by many patient factors. The factors could help patients and providers to make informed decisions for selecting appropriate procedures.


Assuntos
Derivação Gástrica , Laparoscopia , Obesidade Mórbida , Adulto , Humanos , Derivação Gástrica/métodos , Readmissão do Paciente , Obesidade Mórbida/cirurgia , Melhoria de Qualidade , Pontuação de Propensão , Estudos Retrospectivos , Complicações Pós-Operatórias/etiologia , Laparoscopia/efeitos adversos , Gastrectomia/métodos , Resultado do Tratamento
4.
Transl Lung Cancer Res ; 11(5): 802-816, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35693277

RESUMO

Background: The mutation rate of the tumor protein P53 (TP53) has been reported to be greater than 50% in non-small cell lung cancer (NSCLC), and gain-of-function (GOF) mutations in unfolded P53 (TP53R175H and TP53Y220C) have been associated with poor prognosis. However, the best treatment for patients with NSCLC harboring unfolded mutant P53 (mutp53) remains unclear. Triptolide is a natural compound derived from Tripterygium wilfordii that has shown a strong antitumor effect in a variety of cancers. Our study aimed to explore the GOF mutations in unfolded mutp53 (TP53R175H and TP53Y220C) and to clarify the molecular mechanisms by which triptolide regulates the degradation of unfolded mutp53 proteins in NSCLC. Methods: Two unfolded proteins harboring TP53R175H and TP53Y220C mutations were selected to explore their functions in NSCLC progression. NCI-H1299 cells (TP53-null) were transfected with wild-type TP53 (TP53WT), TP53R175H, or TP53Y220C genes and treated with triptolide or a vehicle. Wound healing and transwell assays were performed to measure cell migration and invasion in vitro. Lung metastasis models were constructed through tail vein injection of mutant cells into BALB/c nude mice to evaluate the effect of triptolide on metastasis in vivo. Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), immunoprecipitation, and dual-luciferase reporter assays were performed to explore the relevant molecular mechanisms. Results: Our study revealed that triptolide treatment reduced TP53R175H levels and that the TP53Y220C mutation enhanced the invasion and migration of NCI-H1299 cells. Mechanistically, triptolide promoted TP53R175H and TP53Y220C protein proteasomal degradation mediated through the E3 ligase murine double minute 2 (MDM2) by directly interacting with heat shock protein 70 (HSP70). Moreover, by upregulating HSP70 transcription, triptolide contributed to the protein degradation of the GOF mutp53. Conclusions: Our study reports, for the first time, the mechanism underlying triptolide-regulated protein degradation of TP53R175H or TP53Y220C, which offers new insight into developing a better therapeutic strategy for patients with NSCLC who express the unfolded mutp53 GOF protein.

5.
Biosens Bioelectron ; 117: 818-829, 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30096736

RESUMO

Lactate plays a crucial role in the anaerobic metabolic pathway of humans. In situations of oxygen deficit, its production increases; leading to several life-threatening conditions such as hemorrhage, respiratory failure, trauma or ischemia from lactate acidosis. Lactate level detection and point-of-care (POC) monitoring in a fast, accurate and non-invasive manner is ultimately important for many health care applications. Optical and electrochemical techniques are employed in lactate sensing to achieve high sensitivity and selectivity, miniaturization, portability, simplicity, and low cost. To improve the selectivity and sensitivity, two important enzymes, lactate oxidase (LOx) and lactate dehydrogenese (LDH) are employed. Conventional methods for lactate detection are not fast enough to be used in point-of-care or personal health monitoring settings. Moreover, the existing point-of-care lactate sensing tools follow invasive or partially invasive sampling protocols such as finger pricking. In this review, a comprehensive overview of different lactate biosensing devices is presented. Particularly, the state-of-the-art and prospects of wearable, non-invasive lactate sensing from different biofluids are discussed.


Assuntos
Técnicas Biossensoriais/métodos , Ácido Láctico/análise , Sistemas Automatizados de Assistência Junto ao Leito , Animais , Técnicas Eletroquímicas/métodos , Corantes Fluorescentes/química , Humanos , Oxigenases de Função Mista/metabolismo , Estrutura Molecular , Processos Fotoquímicos , Fótons , Medicina de Precisão , Lágrimas/metabolismo
6.
Biosens Bioelectron ; 87: 522-530, 2017 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-27598854

RESUMO

Multimodal electrochemical technique incorporating both open circuit potential (OCP) and amperometric techniques have been conceptualized and implemented to improve the detection of specific analyte in systems where more than one analyte is present. This approach has been demonstrated through the detection of ethanol while eliminating the contribution of water in a micro fuel cell sensor system. The sensor was interfaced with LMP91000 potentiostat, controlled through MSP430F5529LP microcontroller to implement an auto-calibration algorithm tailored to improve the detection of alcohol. The sensor was designed and fabricated as a three electrode system with Nafion as a proton exchange membrane (PEM). The electrochemical signal of the interfering phase (water) was eliminated by implementing the multimodal electrochemical detection technique. The results were validated by comparing sensor and potentiostat performances with a commercial sensor and potentiostat respectively. The results suggest that such a sensing system can detect ethanol at concentrations as low as 5ppm. The structure and properties such as low detection limit, selectivity and miniaturized size enables potential application of this device in wearable transdermal alcohol measurements.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Eletroquímicas/instrumentação , Etanol/análise , Eletrodos , Desenho de Equipamento , Polímeros de Fluorcarboneto/química , Humanos , Umidade , Limite de Detecção , Membranas Artificiais , Reprodutibilidade dos Testes , Pele/química , Água/química
7.
Biosens Bioelectron ; 86: 595-608, 2016 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-27453988

RESUMO

Potential applications of thin film metamaterials are diverse and their realization to offer miniaturized waveguides, antennas and shielding patterns are on anvil. These artificially engineered structures can produce astonishing electromagnetic responses because of their constituents being engineered at much smaller dimensions than the wavelength of the incident electromagnetic wave, hence behaving as artificial materials. Such micro-nano dimensions of thin film metamaterial structures can be customized for various applications due to their exclusive responses to not only electromagnetic, but also to acoustic and thermal waves that surpass the natural materials' properties. In this paper, the recent major advancements in the emerging fields of diagnostics (sensors) and therapeutics involving thin film metamaterials have been reviewed and underlined; discussing their edge over conventional counterpart techniques; concentrating on their design considerations and feasible ways of achieving them. Challenges faced in sensitivity, precision, accuracy and factors that interfere with the degree of performance of the sensors are also dealt with, herein.


Assuntos
Técnicas Biossensoriais/instrumentação , Monitoramento de Medicamentos/instrumentação , Refratometria/instrumentação , Ressonância de Plasmônio de Superfície/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
8.
Appl Opt ; 51(17): 3768-75, 2012 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-22695654

RESUMO

This paper presented the fabrication and calibration of a clad-modified evanescent based plastic optical fiber (POF) sensor for the detection of ammonia in both stagnant and dynamic aqueous media. This optochemical sensor was based on Oxazine 170 perchlorate (sensing material) and polydimethylsiloxane (PDMS) (protective material) thin layers. A special chemical solution was developed for the etching removal of cladding and a methodology for trapping moisture was exercised. Experimental results on dissolved ammonia detection exhibited short response time (≤10 s), low detection limit (minimum detection limit 1.4 ppm), high sensitivity, and excellent reversibility (over 99%).


Assuntos
Amônia/análise , Tecnologia de Fibra Óptica/instrumentação , Oxazinas/química , Água/química , Calibragem , Dimetilpolisiloxanos/química , Limite de Detecção , Fibras Ópticas
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...