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1.
Adv Mater ; 32(18): e1904205, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-31957144

RESUMO

Ionic liquids (ILs) are widely studied as a safer alternative electrolyte for lithium-ion batteries. The properties of IL electrolytes compared to conventional electrolytes make them more thermally stable, but they also have poor wetting with commercial separators. In a lithium-ion battery, the electrolyte should completely wet out the separator and electrodes to reduce the cell internal resistance. Investigations of cell materials with IL electrolytes have shown that the wetting issues in IL-electrolyte cells are most likely due to poor separator compatibility, not electrode compatibility. A compatible separator must be developed before IL electrolytes can be used in commercial lithium-ion batteries. Herein, separators for IL electrolytes, including commercial and novel separators, are reviewed. Separators with different processing methods, polymers, additives, and different IL electrolytes are considered. Collated, the separator studies show a strong correlation between ionic conductivity and membrane porosity, even more than the electrolyte type. The challenge of a suitable separator for IL electrolytes is not solved yet. Herein, it is revealed that a separator for IL electrolytes will most likely require a combination of high thermal and mechanical stability polymer, ceramic additives, and an optimized manufacturing process.

2.
Biosens Bioelectron ; 101: 227-234, 2018 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-29096360

RESUMO

Flexible epidermal tattoo and textile-based electrochemical biosensors have been developed for vapor-phase detection of organophosphorus (OP) nerve agents. These new wearable sensors, based on stretchable organophosphorus hydrolase (OPH) enzyme electrodes, are coupled with a fully integrated conformal flexible electronic interface that offers rapid and selective square-wave voltammetric detection of OP vapor threats and wireless data transmission to a mobile device. The epidermal tattoo and textile sensors display a good reproducibility (with RSD of 2.5% and 4.2%, respectively), along with good discrimination against potential interferences and linearity over the 90-300mg/L range, with a sensitivity of 10.7µA∙cm3∙mg-1 (R2 = 0.983) and detection limit of 12mg/L in terms of OP air density. Stress-enduring inks, used for printing the electrode transducers, ensure resilience against mechanical deformations associated with textile and skin-based on-body sensing operations. Theoretical simulations are used to estimate the OP air density over the sensor surface. These fully integrated wearable wireless tattoo and textile-based nerve-agent vapor biosensor systems offer considerable promise for rapid warning regarding personal exposure to OP nerve-agent vapors in variety of decentralized security applications.


Assuntos
Ar/análise , Técnicas Biossensoriais/instrumentação , Agentes Neurotóxicos/análise , Compostos Organofosforados/análise , Dispositivos Eletrônicos Vestíveis , Tecnologia sem Fio/instrumentação , Arildialquilfosfatase/química , Eletrodos , Desenho de Equipamento , Humanos , Limite de Detecção , Reprodutibilidade dos Testes , Têxteis , Volatilização
3.
ACS Sens ; 2(4): 553-561, 2017 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-28723187

RESUMO

A flexible glove-based electrochemical biosensor with highly stretchable printed electrode system has been developed as a wearable point-of-use screening tool for defense and food security applications. This disposable-mechanically robust "lab-on-a-glove" integrates a stretchable printable enzyme-based biosensing system and active surface for swipe sampling on different fingers, and is coupled with a compact electronic interface for electrochemical detection and real-time wireless data transmission to a smartphone device. Stress-enduring inks are used to print the electrode system and the long serpentine connections to the wireless electronic interface. Dynamic mechanical deformation, bending, and stretching studies illustrate the resilience and compliance of the printed traces against extreme mechanical deformations expected for such on-glove sampling/sensing operation. An organophosphorus hydrolase (OPH)-based biosensor system on the index finger enables rapid on-site detection of organophosphate (OP) nerve-agent compounds on suspicious surfaces and agricultural products following their swipe collection on the thumb finger. The new wireless glove-based biosensor system offers considerable promise for field screening of OP nerve-agents and pesticides in defense and food-safety applications, with significant speed and cost advantages. Such "lab-on-a-glove" demonstration opens the area of flexible wearable sensors to future on-the-hand multiplexed chemical detection in diverse fields.

4.
Macromol Biosci ; 13(10): 1321-6, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23881528

RESUMO

Flexible and solvent stable fibers are produced after concentrated recombinant honeybee protein solutions are extruded into a methanol bath, dried, drawn in aqueous methanol, then covalently cross-linked using dry heat. Proteins in solution are predominantly coiled coil. Significant levels of non-orientated ß-sheets form during drying or after coagulation in aqueous methanol. Drawing generally aligns the coiled coil component parallel with the fibre axis and ß-sheet component perpendicular to the fiber axis. The fibres are readily handled, stable in the strong protein denaturants, urea and guanidinium, and suitable for a range of applications such as weaving and knitting.


Assuntos
Abelhas/química , Estrutura Secundária de Proteína , Proteínas/química , Seda/química , Animais , Animais Geneticamente Modificados , Abelhas/genética , Proteínas/genética , Soluções/química , Resistência à Tração , Água/química
5.
ACS Comb Sci ; 14(11): 605-12, 2012 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-23072483

RESUMO

A combinatorial approach was developed for the rapid determination of thermochromic behavior of a large number of binary and ternary sterol based thermochromic liquid crystalline formulations. A binary mixture containing cholesteryl oleyl carbonate and cholesteryl nonanoate, and ternary mixtures also containing a third component, either cholesteryl oleate, cholesteryl benzoate, cholesteryl 2,4-dichlorobenzoate or cholesteryl propionate, were formulated via solvent deposition into a black Teflon coated aluminum 96 well plate. The temperature of the well plate was then varied, and the color appearance of the deposited mixture in each well was recorded. This approach allowed expedient examination of the thermochromic behavior for a large range of liquid crystal formulations. The accuracy of the rapid combinatorial technique was validated on selected thermochromic liquid crystal mixture compositions by comparing well thermochromic output with that observed using UV-vis spectroscopy on material produced in gram quantities.


Assuntos
Colesterol/química , Técnicas de Química Combinatória , Cromatografia em Camada Fina , Cristalização
6.
Biomed Mater ; 5(2): 25005, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-20308775

RESUMO

A polyester polycaprolactone-based polyurethane elastomer (PU) and poly-(l-lactide) (PLLA), two common biomaterials, were electrospun to produce membranes with fibres either randomly orientated or aligned. PU was used to produce membranes consisting of smooth fibres. PLLA was used to prepare fibres with a textured surface. Contact angle measurements of the PU and PLLA cast films reveal that they were both below 90 degrees and fully wetted in less than 60 s. These membranes were investigated for the effect of fibre topography and fibre alignment on cell adhesion, using mouse L929 fibroblasts. It was found that the alignment of electrospun fibres controls the directional spreading of fibroblast independent of fibre being smooth or textured.


Assuntos
Materiais Biocompatíveis/química , Fibroblastos/citologia , Fibroblastos/fisiologia , Membranas Artificiais , Poliésteres/química , Poliuretanos/química , Engenharia Tecidual/métodos , Animais , Anisotropia , Adesão Celular/fisiologia , Técnicas de Cultura de Células/métodos , Linhagem Celular , Cristalização/métodos , Eletroquímica/métodos , Matriz Extracelular/química , Teste de Materiais , Camundongos , Conformação Molecular , Rotação , Propriedades de Superfície
7.
Gastrointest Endosc ; 54(5): 633-6, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11677486

RESUMO

BACKGROUND: Patients with head and neck cancer (HNC) benefit from nutritional support by means of PEG tubes, but endoscopy may be impossible when there is partial or complete trismus and/or stenosis or occlusion of the upper aerodigestive tract. METHODS: PEG tubes were placed in 277 patients with HNC. Oral insertion of an endoscope into the esophagus was impossible in 27 patients. Transnasal endoscopy was performed (n = 4). In the cases of high-grade tumor obstruction, the endoscope was introduced into the esophagus through a straight laryngoscope (n = 9). When upper aerodigestive tract occlusion was present, endoscopy with PEG placement was successfully performed during surgery by means of the opened pharynx after tumor resection (n = 12). RESULTS: In 25 of the 27 cases PEG tubes could be placed by using the above alternative techniques. There were no immediate complications, and no complications occurred within 30 days of PEG placement. CONCLUSIONS: Transnasal, straight laryngoscopic, or intraoperative open endoscopy can improve the success rate for PEG tube placement in patients with HNC.


Assuntos
Endoscopia do Sistema Digestório/métodos , Nutrição Enteral/métodos , Neoplasias de Cabeça e Pescoço , Laringoscópios , Adulto , Idoso , Transtornos de Deglutição/etiologia , Nutrição Enteral/instrumentação , Feminino , Neoplasias de Cabeça e Pescoço/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Cavidade Nasal
8.
Eur J Epidemiol ; 17(6): 501-4, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11949720

RESUMO

BACKGROUND AND AIMS: To investigate the prevalence of Helicobacter pylori (HP) infection, as well as possible risk factors affecting its acquisition among young Greek adults. METHODOLOGY: Sera were collected from 153 male young Hellenic Navy recruits (mean age 23.6 y.o.; range, 20-30 y.o.) at induction into the Hellenic Navy during January 1999. An enzyme-linked immunosorbent assay was used to detect HP-specific-IgG antibodies. All the subjects completed a structured questionnaire regarding demographic and socioeconomic data, as well as dietary habits, alcohol and tobacco use and gastrointestinal complaints. Statistical analysis was performed using logistic regression and the chi2 test. RESULTS: The observed crude seropositivity rate was 19.01%. Among the examined parameters the most important predictive variable for HP-IgG status was the current median family income (B = +0.98, SE(B) = 0.56, p = 0.08, by logistic regression), which however, did not attain adequate statistical significance. The rate of seropositivity for HP that we observed is much lower than rates reported in older studies in this narrow-aged group in Greece. Probably the changes that ensued in life-style in Greece during the last 10 years resulted in a reduction in HP seropositivity.


Assuntos
Infecções por Helicobacter/epidemiologia , Helicobacter pylori , Militares , Adulto , Anticorpos Antibacterianos/sangue , Ensaio de Imunoadsorção Enzimática/métodos , Grécia/epidemiologia , Infecções por Helicobacter/sangue , Infecções por Helicobacter/imunologia , Helicobacter pylori/imunologia , Humanos , Masculino , Medicina Naval , Prevalência , Análise de Regressão , Fatores de Risco , Estudos Soroepidemiológicos , Inquéritos e Questionários
9.
Ann Nucl Med ; 14(3): 217-21, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10921488

RESUMO

A 56-yr-old man, two months after an operation for an acoustic neurinoma, gradually developed dyspnea. Massive pulmonary embolism (MPE), with a significant right-to-left (R-L) shunt, was seen in a perfusion scan of the lungs with Tc-99m MAA. Radioactivity was noted in the thyroid, spleen, kidneys and brain. A cardiac ultrasound study did not reveal intracardiac shunting. A few days later, when the patient's condition improved, another perfusion scan of the lungs did not show the shunt, whereas a subsequent digital subtraction angiographic study confirmed the diagnosis of MPE but failed to reveal the cause of the shunt. In the absence of any possible pathophysiological mechanism, to explain the observed R-L shunt, we deduce that the particles of Tc-99m MAA might have passed through the precapillary pulmonary arteriovenous anastomoses and/or through dilated pulmonary capillaries, as a result of highly increased pulmonary vascular pressure due to MPE.


Assuntos
Defeitos dos Septos Cardíacos/diagnóstico por imagem , Pulmão/diagnóstico por imagem , Embolia Pulmonar/complicações , Embolia Pulmonar/diagnóstico por imagem , Compostos Radiofarmacêuticos , Agregado de Albumina Marcado com Tecnécio Tc 99m , Angiografia Digital , Ecocardiografia , Humanos , Masculino , Pessoa de Meia-Idade , Neuroma Acústico/cirurgia , Cintilografia , Compostos Radiofarmacêuticos/farmacocinética , Agregado de Albumina Marcado com Tecnécio Tc 99m/farmacocinética , Distribuição Tecidual
10.
Orv Hetil ; 140(24): 1347-52, 1999 Jun 13.
Artigo em Húngaro | MEDLINE | ID: mdl-10439635

RESUMO

UNLABELLED: Patients who are not able to eat do need tube feeding. The most preferred way of artificial enteral nutritional support is feeding via percutaneous endoscopic gastrostomy (PEG) tubes. Head and neck cancer patients do represent a special group of patients needing a PEG. On the one hand at the time of admission to the hospital they are mainly undernourished. On the other hand the failure rate of placing a PEG is the highest among them. Furthermore in the perioperative period nasogastric tubes do cause a lot of complications in these settings. 188 PEG placements were carried out from July 1995 till November 1998. INDICATIONS: head and neck cancer (n = 171), neurologic disorders (n = 17). PEG tubes were placed 76 times during intratracheal narcosis and 112 times following local anaesthesia. 39 times there was a prior abdominal surgery in our patients medical history. The pull-through, the push-wire and the introducer techniques were used. Beside the usual oro-gastric way of endoscopying (n = 163), 25 times the following alternative ways of entering the upper gastrointestinal tract were used: transnasal route (n = 4), through a Kleinsasser type direct laryngoscope (n = 7) and via the opened pharynx (n = 14). No immediate or late onset procedure related complications occurred. During a follow-up of 22,480 tubedays 26 minor (dermatitis n = 24, ulcer n = 2) and 8 major (abscess n = 4, perforation/peritonitis n = 3, stomach and bowel wall necrosis n = 1) complications occurred. The success rate of placing a PEG was 98.9%. In head and neck cancer patients placing a PEG is suggested when there is a need for at least a 7 days time tube-feeding. Using the described alternative ways, a PEG tube can be placed almost always. Because of the uncertain outcome, nutritional support via PEG tubes is suggested also in cachectic patients and in vegetative state as well.


Assuntos
Gastrostomia/métodos , Neoplasias de Cabeça e Pescoço/cirurgia , Nutrição Enteral , Gastroscopia/métodos , Humanos , Estudos Retrospectivos
13.
Orv Hetil ; 137(23): 1263-5, 1996 Jun 09.
Artigo em Húngaro | MEDLINE | ID: mdl-8757097

RESUMO

The authors present the case of a young male with massive haemothorax caused by intralobar bronchopulmonary sequestration. Angiography is necessary for the exact diagnosis of bronchopulmonary sequestration. The most common site of intrapulmonary type sequestration is the left lower lobe of the lung. In this case the aberrant artery was originated from the abdominal aorta. During thoracotomy after ligature of the aberrant vessels S5,S10 segmentectomy was performed. The authors emphasize that the rare cause of rapid anaemia in consequence of haemothorax could be intralobar bronchopulmonary sequestration.


Assuntos
Sequestro Broncopulmonar/diagnóstico , Hemotórax/etiologia , Adulto , Sequestro Broncopulmonar/complicações , Sequestro Broncopulmonar/cirurgia , Diagnóstico Diferencial , Humanos , Masculino
14.
Orv Hetil ; 136(4): 189-93, 1995 Jan 22.
Artigo em Húngaro | MEDLINE | ID: mdl-7870413

RESUMO

An old women was in an 8-year-period 9 times admitted to the hospital because of severe mental disturbances. The average serum sodium concentration was 126.25 +/- 2.43 mmol/l at the admissions; it increased to 139.44 +/- 1.40 mmol/l after intravenous infusion of hypertonic solutions accompanied with the disappearance of the mental disturbances. The patient was usually chronically hyponatremic due to the increased water intake and the insufficient water excretion. The latter was induced by the augmented vasopressin levels. The remarkable feature of the syndrome of inappropriate antidiuretic hormone secretion was its association with lowered blood level of atrial natriuretic factor accompanied by sodium, and volume depletion. Discontinuation of the exaggerated water intake resulted in the elimination of the permanent hyponatremia; no episode of water intoxication occurred during the last 3 and 1/2 years.


Assuntos
Fator Natriurético Atrial/sangue , Hiponatremia/etiologia , Síndrome de Secreção Inadequada de HAD/etiologia , Intoxicação por Água , Idoso , Transtornos Cognitivos/etiologia , Comportamento de Ingestão de Líquido , Feminino , Humanos , Hiponatremia/terapia , Síndrome de Secreção Inadequada de HAD/sangue , Síndrome de Secreção Inadequada de HAD/terapia , Vasopressinas/sangue , Intoxicação por Água/sangue , Intoxicação por Água/etiologia , Intoxicação por Água/psicologia , Intoxicação por Água/terapia
15.
Orv Hetil ; 135(13): 699-701, 1994 Mar 27.
Artigo em Húngaro | MEDLINE | ID: mdl-8170670

RESUMO

A case of a young man with eosinophilic gastroenteritis with mucosal involvement in the antrum and duodenum is presented. The diagnosis was based on endoscopic biopsy with histological examination, peripheral blood eosinophilia and gastrointestinal symptoms, like abdominal cramping, nausea, vomiting and diarrhoea. Parasitic and extraintestinal diseases were ruled out. Steroid therapy was effective. It is emphasised that in the cases of abdominal complaints accompanied by eosinophilia, this rare disease should be considered.


Assuntos
Eosinofilia/complicações , Gastroenterite/complicações , Adulto , Biópsia , Dietoterapia , Endoscopia Gastrointestinal , Eosinofilia/tratamento farmacológico , Gastroenterite/sangue , Gastroenterite/tratamento farmacológico , Humanos , Masculino , Esteroides/uso terapêutico
16.
Orv Hetil ; 132(31): 1691-4, 1991 Aug 04.
Artigo em Húngaro | MEDLINE | ID: mdl-1866164

RESUMO

The authors have been working on the cytostatic treatment of gastric cancer since 1982. The patients were divided into two groups. Group 1.: Patients who had been operated radically on gastric cancer. Group 2.: Patients who had advanced gastric cancer. The following cytostatic drugs were administrated: Cyclophosphamide, Vincristine, Ftorafur. The patients who had been operated on radically were given adjuvant cytostatic treatment for 3 months according to their own protocol. The patients advanced gastric cancer got life long systemic cytostatic treatment. Between 1982 and 1989, 36 histologically proven gastric carcinoma patients were treated. The effectiveness of the therapy was measured by the survival time from the beginning of the cytostatic treatment. The control group 67 patients consisted of radically or palliative operated patients of the surgical department of those who had not got chemotherapeutic treatment. According to the experiences of the authors, the survival time was prolonged considerably by cytostatic treatment in the group of palliative operated or inoperable patients.


Assuntos
Ciclofosfamida/uso terapêutico , Neoplasias Gástricas/tratamento farmacológico , Tegafur/uso terapêutico , Vincristina/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Protocolos Clínicos , Gastrectomia , Humanos , Indução de Remissão , Neoplasias Gástricas/cirurgia , Taxa de Sobrevida
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