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1.
Heliyon ; 9(7): e17963, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37456019

RESUMO

As the recent COVID-19 pandemic has clearly demonstrated, appropriate state support policies are crucial for supporting industrial supply chains during crises to prevent viable businesses from defaulting. In this context, this study proposes a hybrid credit risk model to appropriately size public interventions for viable (worthy) businesses through systematic risk assessment during a period of turmoil. This study discusses the effects of the credit crunch-based economic downturn and proposes a methodology to assist policymakers in managing limited public resources to effectively support industrial supply chains. The proposed approach initially focuses on the dynamics of credit risk during economic recession periods, identifying the conditions that may justify a public intervention strategy based on public guarantees. Subsequently, a hybrid credit risk model is developed to appropriately size public interventions by quantifying systematic risk. Finally, a numerical application is presented to demonstrate the effectiveness of the proposed approach.

2.
Anal Chim Acta ; 1190: 339215, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34857136

RESUMO

In this work electrochemical sensors fabricated from compact disc material (waste or new) are used to quantify chloride ions in different types of samples. All three electrodes, working, counter, and pseudo-reference electrodes, were fabricated from the compact disc and directly used. Different parameters were studied in order to demonstrate the possibility of using this waste material for efficient and low-cost electrochemical sensors. Chloride sensing performance was evaluated using linear scan voltammetry as the detection technique. A sensitivity of 0.174 mA mM-1 cm-2 with a limit of detection of 20 µM and excellent selectivity against many interferents was observed. Selectivity and reproducibility tests were also carried out, showing excellent results. Sensors were also validated with real samples (drinking and sea water, milk, sweat and physiological solutions) with results comparable to conventional techniques. Our results show the applicability and suitability of these low-cost sensors, for detection of those analytes for which, silver, has high sensitivity and selectivity.


Assuntos
Cloretos , Técnicas Eletroquímicas , Discos Compactos , Eletrodos , Reprodutibilidade dos Testes
3.
Anal Chim Acta ; 1187: 339124, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34753568

RESUMO

Dopamine is an important neurotransmitter involved in many human biological processes as well as in different neurodegenerative diseases. Monitoring the concentration of dopamine in biological fluids, i.e., blood and urine is an effective way of accelerating the early diagnosis of these types of diseases. Electrochemical sensors are an ideal choice for real-time screening of dopamine as they can achieve fast, portable inexpensive and accurate measurements. In this work, we present electrochemical dopamine sensors based on reduced graphene oxide coupled with Au or Pt nanoparticles. Sensors were developed by co-electrodeposition onto a flexible substrate, and a systematic investigation concerning the electrodeposition parameters (concentration of precursors, deposition time and potential) was carried out to maximize the sensitivity of the dopamine detection. Square wave voltammetry was used as an electrochemical technique that ensured a high sensitive detection in the nM range. The sensors were challenged against synthetic urine in order to simulate a real sample detection scenario where dopamine concentrations are usually lower than 600 nM. Our sensors show a negligible interference from uric and ascorbic acids which did not affect sensor performance. A wide linear range (0.1-20 µm for gold nanoparticles, 0.1-10 µm for platinum nanoparticles) with high sensitivity (6.02 and 7.19 µA µM-1 cm-2 for gold and platinum, respectively) and a low limit of detection (75 and 62 nM for Au and Pt, respectively) were achieved. Real urine samples were also assayed, where the concentrations of dopamine detected aligned very closely to measurements undertaken using conventional laboratory techniques. Sensor fabrication employed a cost-effective production process with the possibility of also being integrated into flexible substrates, thus allowing for the possible development of wearable sensing devices.


Assuntos
Grafite , Nanopartículas Metálicas , Ácido Ascórbico , Dopamina , Técnicas Eletroquímicas , Eletrodos , Ouro , Humanos , Platina , Ácido Úrico
4.
Blood Transfus ; 7(3): 193-203, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-19657483

RESUMO

BACKGROUND: One of the most serious risks of blood transfusions is an error in ABO blood group compatibility, which can cause a haemolytic transfusion reaction and, in the most severe cases, the death of the patient. The frequency and type of errors observed suggest that these are inevitable, in that mistakes are inherent to human nature, unless significant changes, including the use of computerised instruments, are made to procedures. METHODS: In order to identify patients who are candidates for the transfusion of blood components and to guarantee the traceability of the transfusion, the Securblood system (BBS srl) was introduced. This system records the various stages of the transfusion process, the health care workers involved and any immediate transfusion reactions. The patients and staff are identified by fingerprinting or a bar code. The system was implemented within Ragusa hospital in 16 operative units (ordinary wards, day hospital, operating theatres). RESULTS: In the period from August 2007 to July 2008, 7282 blood components were transfused within the hospital, of which 5606 (77%) using the Securblood system. Overall, 1777 patients were transfused. In this year of experience, no transfusion errors were recorded and each blood component was transfused to the right patient. We recorded 33 blocks of the terminals (involving 0.6% of the transfused blood components) which required the intervention of staff from the Service of Immunohaematology and Transfusion Medicine (SIMT). Most of the blocks were due to procedural errors. CONCLUSIONS: The Securblood system guarantees complete traceability of the transfusion process outside the SIMT and eliminates the possibility of mistaken identification of patients or blood components. The use of fingerprinting to identify health care staff (nurses and doctors) and patients obliges the staff to carry out the identification procedures directly in the presence of the patient and guarantees the presence of the doctor at the start of the transfusion.


Assuntos
Transfusão de Componentes Sanguíneos , Dermatoglifia , Processamento Eletrônico de Dados/instrumentação , Processamento Eletrônico de Dados/métodos , Sistemas Computadorizados de Registros Médicos/instrumentação , Feminino , Humanos , Masculino
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