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1.
Epilepsy Behav ; 129: 108636, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35259626

RESUMO

OBJECTIVE: The effect of the frontal lobe on cognitive functions is a subject that has been studied frequently. However, cognitive impairments that can be seen in frontal lobe epilepsy are less addressed. In previous studies on decision-making disorders in patients with epilepsy, patients with temporal lobe epilepsy (TLE) were frequently studied, and it was reported that decision-making disorders could be encountered in this patient group. In this study, we aimed to compare the decision-making performance of patients with cryptogenic frontal lobe epilepsy (FLE) and TLE in ambiguous situations. METHODS: Twenty patients with TLE (mean age: 34.10 ±â€¯11.71 years) and 20 patients with FLE (mean age: 32.25 ±â€¯11.92 years) were enrolled in the study and their cognitive performance was compared with 20 healthy controls (mean age: 33.15 ±â€¯13.66 years). Neuropsychological tests were performed on the participants for sleep, depression, anxiety, impulsivity, intelligence, attention, language functions, memory and learning, and frontal axis functions. Decision-making performance in ambiguous situations was studied using the Iowa Gambling Task (IGT). RESULTS: Iowa Gambling Task performances of patients with FLE and TLE were found to be worse than in healthy controls (p = 0.049). Although there was no statistically significant difference when the decision-making of patients with TLE and FLE was compared, it was observed that patients with FLE chose higher risk cards compared with those with TLE. The performances of the neuropsychological subgroup tests of patients with TLE and FLE in attention, language functions, memory and learning, and frontal axis functions were found to be significantly worse than in healthy subjects. CONCLUSION: Decision-making in patients with TLE and FLE in ambiguous situations is similarly impaired compared with healthy controls.


Assuntos
Epilepsia do Lobo Frontal , Epilepsia do Lobo Temporal , Adulto , Cognição , Epilepsia do Lobo Frontal/psicologia , Epilepsia do Lobo Temporal/complicações , Epilepsia do Lobo Temporal/psicologia , Humanos , Pessoa de Meia-Idade , Testes Neuropsicológicos , Lobo Temporal , Adulto Jovem
2.
Appl Opt ; 60(28): 8949-8955, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34613123

RESUMO

We present highly efficient green, yellow, and red filters based on a metal-dielectric structure. The filters encompass only five layers of alternating zinc tin oxide and silver thin films that are grown on soda lime glass and white light-emitting diodes (LEDs) using direct current magnetron sputtering at room temperature. The designed filters provide efficient color filtering in the visible spectrum. High purity colored light is obtained by direct application of filters on LEDs as color converters. The presented method offers an easy way for realizing different colors by tuning the thicknesses of layers in the structure.

3.
Colorectal Dis ; 23(12): 3141-3151, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34346554

RESUMO

AIM: The aim of this study is to demonstrate our video training tool developed to teach and standardize complete mesocolic excision (CME) for right-sided colon cancer and also to present our long-term oncological outcomes. METHOD: Educational narrative videos were produced to demonstrate the technical steps of CME. First, a three-dimensional animation video was prepared. Then cadaveric dissections were recorded in a step-by-step fashion, following the sequences of open and minimally invasive surgery. These were followed by videos of real-life demonstrations of surgical procedures, enhanced by superimposed animations of key anatomical structures. In order to demonstrate the impact of this training module on outcomes of patients undergoing CME, we retrospectively queried data from before (2005-2010) and after (2011-2019) implementation of standardized CME in our practice. RESULTS: A total of 180 consecutive patients underwent right hemicolectomy between 2005 and 2019. Fifty-four patients underwent surgery before and 126 patients after CME principles were elaborated and standardized. Of those patients who had surgery after the training module, 58 (46%) underwent open surgery and 68 (54%) underwent laparoscopic colectomy. Demographics, perioperative parameters and morbidity were comparable between the groups. The 5-year overall and disease-free survival rates were significantly improved after implementation of CME training (p = 0.059 and p = 0.041, respectively). Also, 5-year overall and disease-free survival rates for all patients were considerably better than our reported national outcomes. CONCLUSION: Our comprehensive step-by-step training video module for the CME technique demonstrates surgical anatomical planes and important vascular structures and variations. The video also helps standardization of the CME technique and should contribute to improved histopathological and oncological outcomes.


Assuntos
Neoplasias do Colo , Laparoscopia , Mesocolo , Colectomia , Neoplasias do Colo/cirurgia , Computadores , Humanos , Excisão de Linfonodo , Mesocolo/cirurgia , Padrões de Referência , Estudos Retrospectivos , Resultado do Tratamento
4.
Med Princ Pract ; 26(6): 573-578, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29131002

RESUMO

OBJECTIVE: The aim was to compare the effects of low tidal volume (VT) and moderate positive end-expiratory pressure (PEEP) with high VT and zero end-expiratory pressure (ZEEP) on postoperative pulmonary functions and oxygenation in patients undergoing robot-assisted laparoscopic radical prostatectomy. SUBJECTS AND METHODS: Forty-four patients were randomized into low VT-PEEP and high VT-ZEEP groups. The patients were ventilated with a VT of 6 mL/kg and 8 cm H2O PEEP in the low VT-PEEP group and a VT of 10 mL/kg and 0 cm H2O PEEP in the high VT-ZEEP group. Preoperative and postoperative spirometric measurements were done and chest X-rays were evaluated using the radiological atelectasis score (RAS). p < 0.05 was considered statistically significant. RESULTS: The intraoperative and postoperative arterial partial pressure of oxygen and arterial oxygen saturation values were significantly higher in the low VT-PEEP group than in the high VT-ZEEP group. At all times, the arterial-to-alveolar oxygenation gradients were significantly lower in the low VT-PEEP group than in the high VT-ZEEP group. Preoperative RAS were similar in both groups, but the postoperative RAS was significantly lower in the low VT-PEEP group (p < 0.001). Forced vital capacity, forced expiratory volume in 1 s, and peak expiratory flow rate recorded postoperatively were significantly lower in the high VT-ZEEP group (p < 0.001). CONCLUSIONS: Postoperative pulmonary functions were less impaired in patients ventilated with a VT of 6 mL/kg and 8 cm H2O PEEP than in patients ventilated with a VT of 10 mL/kg and ZEEP.


Assuntos
Laparoscopia/métodos , Respiração com Pressão Positiva/métodos , Prostatectomia/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Oxigênio/sangue , Respiração com Pressão Positiva/efeitos adversos , Período Pós-Operatório , Estudos Prospectivos , Testes de Função Respiratória , Volume de Ventilação Pulmonar
5.
Neuroreport ; 28(18): 1215-1220, 2017 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-28902707

RESUMO

Recently, we showed that murine dorsal root ganglion (DRG) Car8 expression is a cis-regulated eQTL that determines analgesic responses. In this report, we show that transduction through sciatic nerve injection of DRG with human wild-type carbonic anhydrase-8 using adeno-associated virus viral particles (AAV8-V5-CA8WT) produces analgesia in naive male C57BL/6J mice and antihyperalgesia after carrageenan treatment. A peak mean increase of about 4 s in thermal hindpaw withdrawal latency equaled increases in thermal withdrawal latency produced by 10 mg/kg intraperitoneal morphine in these mice. Allometric conversion of this intraperitoneal morphine dose in mice equals an oral morphine dose of about 146 mg in a 60-kg adult. Our work quantifies for the first time analgesia and antihyperalgesia in an inflammatory pain model after DRG transduction by CA8 gene therapy.


Assuntos
Analgésicos Opioides/uso terapêutico , Biomarcadores Tumorais/uso terapêutico , Hiperalgesia/terapia , Morfina/uso terapêutico , Manejo da Dor/métodos , Limiar da Dor/fisiologia , Dor/fisiopatologia , Adenoviridae/genética , Animais , Biomarcadores Tumorais/genética , Carragenina/toxicidade , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Gânglios Espinais/efeitos dos fármacos , Gânglios Espinais/metabolismo , Humanos , Inflamação/induzido quimicamente , Inflamação/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Dor/tratamento farmacológico , Dor/etiologia , Medição da Dor/efeitos dos fármacos , Limiar da Dor/efeitos dos fármacos , Tempo de Reação/efeitos dos fármacos , Transdução Genética
6.
Anesth Essays Res ; 11(2): 458-462, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28663641

RESUMO

BACKGROUND: The postdural puncture headache (PDPH) and postdural puncture backache (PDPB) are well-known complications of spinal anesthesia. There are some attempts to reduce the frequency of complication such as different design of the spinal needles. AIMS: The primary outcome of this study is to compare the incidence of PDPH between 26-gauge Atraucan and 26-gauge Quincke spinal needles in elective cesarean operations. The severity of symptoms, the incidence of backache, technical issues, and comparison of cost of needles are secondary outcomes. MATERIALS AND METHODS: After Investigational Review Board approval, a randomized, prospective, double-blinded study was designed in 682 American Society of Anesthesiologists I-II women having elective cesarean operations under spinal anesthesia. Patients were divided into two groups as 26-gauge Atraucan Group A (n = 323) and 26-gauge Quincke spinal needles Group Q (n = 342). All patients were questioned about backache 1 week later. Differences between categorical variables were evaluated with Chi-square test. Continuous variables were compared by Student's t-test for two independent groups. A two-sided P < 0.05 was considered statistically significant for all analyses. RESULTS: There were no significant differences between groups in all demographic data. The one attempt success rate of the dural puncture in Group A (70,58%) and in Group Q (69.3%) was similar (P > 0.05). The incidence of PDPH was 6.5% in Group A and 4.9% in Group Q (P > 0.05). The epidural blood patch was performed to the three patients in Group A and five patients in Group Q who had severe headache (P > 0.05). The incidence of PDPB was 4.33% versus 2.04% in Group A and Group Q (P > 0.05). CONCLUSIONS: The incidence of complication rates and technical handling characteristics did not differ between two groups. Quincke needle is cheaper than Atracaun needle, so it can be a cost-effective choice in obstetric patients.

7.
Mamm Genome ; 28(9-10): 407-415, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28547032

RESUMO

Carbonic anhydrase-8 (Car8 mouse gene symbol) is devoid of enzymatic activity, but instead functions as an allosteric inhibitor of inositol trisphosphate receptor-1 (ITPR1) to regulate this intracellular calcium release channel important in synaptic functions and neuronal excitability. Causative mutations in ITPR1 and carbonic anhydrase-8 in mice and humans are associated with certain subtypes of spinal cerebellar ataxia (SCA). SCA mice are genetically deficient in dorsal root ganglia (DRG) Car8 expression and display mechanical and thermal hypersensitivity and susceptibility to subacute and chronic inflammatory pain behaviors. In this report, we show that DRG Car8 expression is variable across 25 naïve-inbred strains of mice, and this cis-regulated eQTL (association between rs27660559, rs27706398, and rs27688767 and DRG Car8 expression; P < 1 × 10-11) is correlated with nociceptive responses in mice. Next, we hypothesized that increasing DRG Car8 gene expression would inhibit intracellular calcium release required for morphine antinociception and might correlate with antinociceptive sensitivity of morphine and perhaps other analgesic agents. We show that mean DRG Car8 gene expression is directly related to the dose of morphine or clonidine needed to provide a half-maximal analgesic response (r = 0.93, P < 0.00002; r = 0.83, P < 0.0008, respectively), suggesting that greater DRG Car8 expression increases analgesic requirements. Finally, we show that morphine induces intracellular free calcium release using Fura 2 calcium imaging in a dose-dependent manner; V5-Car8 WT overexpression in NBL cells inhibits morphine-induced calcium increase. These findings highlight the 'morphine paradox' whereby morphine provides antinociception by increasing intracellular free calcium, while Car8 and other antinociceptive agents work by decreasing intracellular free calcium. This is the first study demonstrating that biologic variability associated with this cis-eQTL may contribute to differing analgesic responses through altered regulation of ITPR1-dependent calcium release in mice.


Assuntos
Analgésicos/farmacologia , Biomarcadores Tumorais/genética , Gânglios Espinais/enzimologia , Regulação da Expressão Gênica/genética , Variação Genética/efeitos dos fármacos , Proteínas do Tecido Nervoso/genética , Medição da Dor/efeitos dos fármacos , Locos de Características Quantitativas/genética , (trans)-Isômero de 3,4-dicloro-N-metil-N-(2-(1-pirrolidinil)-ciclo-hexil)-benzenoacetamida/farmacologia , Animais , Cálcio/metabolismo , Clonidina/farmacologia , Relação Dose-Resposta a Droga , Variação Genética/genética , Estudo de Associação Genômica Ampla , Masculino , Camundongos , Morfina/farmacologia , Variantes Farmacogenômicos , Sequências Reguladoras de Ácido Nucleico/genética
8.
Minerva Anestesiol ; 83(3): 274 - 281, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-27922254

RESUMO

BACKGROUND: Sevoflurane is a commonly used inhalation agent. There are two forms of sevoflurane in Turkey. The aim of this study was to evaluate the effects of original versus generic sevoflurane products on hemodynamics, time to reach 1 MAC level, inspired and expired sevoflurane levels and postoperative recovery profile. METHODS: Seventy patients undergoing general anaesthesia were divided into two groups as Group Sevo or Group Sojo. After intravenous induction of anaesthesia (with the same drugs in both groups), inhalation anaesthetic was started. Hemodynamic parameters, Bispectral index (BIS), time to reach 1MAC level, inspired and expired sevoflurane levels, % vaporizer concentration of sevoflurane, additional remifentanil doses were recorded. In the awakening period, decreasing times of MAC 0.5, 0.4, 0.3, BIS levels, sedation-agitation and Aldrete scores were recorded. RESULTS: The time to reach 1MAC level was shorter in Group Sevo than in Group Sojo (p=0.01). The fractions of inspired sevoflurane levels were higher at 4, 6, 8, 10, 15, 30, 35, 45. minutes, the fractions of expired sevoflurane levels were higher at 4, 6, 8, 10, 15, 20. minutes in Group Sevo (p < 0.05). In the awakening period and postoperatively, there were no differences in recorded parameters between the groups. CONCLUSION: Although there are differences in maintenance period of the anaesthesia, the two products seem to be comparable routine anaesthesia practice. But further studies are needed to enhance our knowledge.

10.
J Matern Fetal Neonatal Med ; 29(6): 962-6, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25845277

RESUMO

OBJECTIVE: In this study, the effect of perioperative uses of low dose ketamine on post-operative wound pain and analgesic consumption in patients undergoing elective Cesarean section was evaluated. METHODS: In randomized, double blind clinical trial, 52 women with American Society of Anesthesiologists (ASA) class I-II identification undergoing elective Cesarean section in general anesthesia were enrolled. In the ketamine group (group K), a ketamine bolus of 0.5 mg kg(-1) IV was administered at the time of induction of general anesthesia. After induction, a ketamine infusion of 0.25 mg kg(-1) h(-1) was started and discontinued at the end of surgery. Patients allocated to the control group (group C) were given identical volumes of saline. The cumulative dose of morphine consumption after surgery was measured as the primary outcome of this study. Secondary outcomes were pain control assessed by numeric rating scale (NRS) and need for rescue analgesia and incidence of side effects. RESULTS: The mean 24-h morphine consumption was lower in group K (p = 0,001). At 15 min postoperatively, NRS values were lower in group K than group C (p = 0,001). There was no difference among groups regarding the need for supplemental analgesia (rescue diclofenac doses) (p > 0.05). CONCLUSIONS: Perioperative uses of low dose ketamine decreased post-operative opioid requirements, which was observed long after the normal expected duration of ketamine.


Assuntos
Analgésicos/administração & dosagem , Cesárea , Ketamina/administração & dosagem , Dor Pós-Operatória/prevenção & controle , Adulto , Anestesia Geral , Método Duplo-Cego , Feminino , Humanos , Período Perioperatório , Gravidez
11.
J Forensic Leg Med ; 36: 32-6, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26367781

RESUMO

Crimean-Congo Hemorrhagic Fever (CCHF) is an acute zoonotic infection caused by the CCHF virus. The viruses' activity peaks during April and May with a mortality rate of 3-30%. Transmission of the virus to human occurs through tick bites or exposure to infected animals' tissues or blood. The major at-risk group includes farmers living in endemic areas. Health-care workers are the second most affected group. Virus has shown up in a diverse geographic area which includes Middle East, Asia, Africa and Eastern Europe and is considered one of the most wide-spread tick borne infections. The most recent cases are from Iran and Turkey. This article represents autopsy results of four CCHF infected cases in 2011 and 2012, in Ankara, Turkey.


Assuntos
Médicos Legistas , Febre Hemorrágica da Crimeia/diagnóstico , Febre Hemorrágica da Crimeia/transmissão , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Adolescente , Adulto , Criança , Feminino , Hemorragia/patologia , Vírus da Febre Hemorrágica da Crimeia-Congo , Humanos , Controle de Infecções , Masculino , Turquia , Adulto Jovem
12.
Turk J Anaesthesiol Reanim ; 43(1): 50-4, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27366465

RESUMO

Diaphragmatic hernia is usually congenital. However, it is rarely traumatic and can stay asymptomatic. In this report, we aimed to present the anaesthetic management of a patient with diaphragmatic hernia due to previous trauma (14 years ago), which was diagnosed incidentally during surgery for rectal cancer. The patient (53 years, 56 kg, 165 cm, American Society of Anaesthesiologist (ASA) II), to whom laparoscopic surgery was planned because of rectal cancer, had a history of falling from a height 14 years ago. Preoperatively, the patient did not have any sign except small right diaphragmatic elevation on the chest x-ray. After induction, maintenance of anaesthesia was continued with sevoflurane and O2/N2O. The patient was given a 30° Trendelenburg position. When the trochars were inserted by the surgeon, the diaphragmatic hernia was seen on the right part of the diaphragm, which was hidden by the liver. The surgery was continued laparoscopically but with low pressure (12 mmHg), because the patient did not have any haemodynamic and respiratory instability. The patient, who had stable haemodynamic parameters and no respiratory complications during the operation, was transferred to the ward for monitorised care. Traumatic diaphragmatic hernias can be detected incidentally after a long period of acute event. In our case, it was diagnosed during laparoscopic surgery. The surgery was completed with appropriate and careful haemodynamic monitoring and low intra-abdominal pressure under inhalational anaesthesia without any impairment in the patient's haemodynamic and respiratory parameters.

13.
Turk J Anaesthesiol Reanim ; 43(2): 140-1, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27366485
15.
North Clin Istanb ; 1(1): 39-44, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-28058300

RESUMO

OBJECTIVE: Axillary plexus block is one of the widely used technique for upper extremity surgery. In this study, we retrospectively evaluated the single injection axillary plexus block technique we used in our rutine anesthesia practice, between August 2010-March 2011. METHODS: Medical records of ASA I-III, 40 17 female and 23 male patients who underwent elective single injection axillary block performed by neurostimulation technique in elective distal part of the arm, forearm and hand surgeries were evaluated, retrospectively. Axillary block was performed with a nerve stimulator, and a 22 G, 50 mm insolated needle. The needle was inserted immediately superior to axillary artery, advanced through the lateral border of the pectoralis major muscle and to the most proximal part of the axilla. The local anesthetic mixture (1% lidocaine 20 ml + 0.25% bupivacaine 15 ml) was injected to the place (point) where the distal motor responses of the median and ulnar nerves were elicited at the same time, before dropping the stimulation current down to 0.5 mA. In our study, demographic data, motor and sensory block times, the success rate and the complications of the block were evaluated. RESULTS: The mean block performance time was 1.21±0.39 min in our 40 patients. The onset time of the motor block was 14.20±4.96 min and the sensory block was 17.19±2.71 min, respectively. The success rate of the block was 97.5 percent. No complication was found during 24 hours postoperatively. The sensory and motor functions returned properly in all patients. CONCLUSION: In our study we found that the single injection axillary block tecnique was easy to perform with its higher success, and lower complication rates. Therefore we concluded that axillary block should be supported in appropriate cases.

16.
Surg Laparosc Endosc Percutan Tech ; 21(2): 98-100, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21471801

RESUMO

OBJECTIVE: To investigate to what effect active subdiaphragmatic gas aspiration reduces pain after a laparoscopic cholecystectomy. MATERIALS AND METHODS: A total of 104 patients undergoing laparoscopic cholecystectomy were randomly placed into 2 groups. Group I included active subdiaphragmatic gas aspiration (n=52) while group II included simple evacuation (n=52) without any additional procedures. Postoperative analgesic requirements were recorded and the level of postoperative abdominal and shoulder pain was assessed using a numeric scale after 24 postoperative hours. Data were analyzed using the χ test for nonparametric data and Student t test for parametric data. RESULTS: Age, volume of CO2 used during surgery, and operation duration were similar in the 2 groups. The simple evacuation group (group II) experienced more shoulder and abdominal pain postoperatively when compared with the active subdiaphragmatic aspiration group (group I) and had a higher use of analgesics during the postoperative period. CONCLUSIONS: Active subdiaphragmatic gas aspiration after a laparoscopic cholecystectomy is a simple procedure that can effectively reduce postoperative abdominal and shoulder pain and as a result the need for analgesics.


Assuntos
Dor Abdominal/prevenção & controle , Colecistectomia Laparoscópica/efeitos adversos , Dor Pós-Operatória/prevenção & controle , Troca Gasosa Pulmonar , Dor de Ombro/prevenção & controle , Dor Abdominal/etiologia , Analgesia Controlada pelo Paciente , Distribuição de Qui-Quadrado , Colecistectomia Laparoscópica/estatística & dados numéricos , Intervalos de Confiança , Feminino , Indicadores Básicos de Saúde , Humanos , Tempo de Internação/estatística & dados numéricos , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória/etiologia , Dor de Ombro/etiologia , Turquia
17.
Arch Gerontol Geriatr ; 53(3): e267-70, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21176978

RESUMO

The aging of the population is one of the most important demographic events of the 21st century. The aim of this study is to define the basic variables related with criminal behavior among the elderly for cases over 60 years. A retrospective assessment of the criminal data (255 cases) consists of the period between 2000 and 2005 of the Council of Forensic Medicine, Turkish Ministry of Justice. Of the cases whose average age is 68.2±6.9, 25 of the 56 cases were diagnosed as ill. Out of 225 elderly who had committed a criminal act 56 of them had a medical antecedent which is a psychiatric diagnosis. Whether or not they had a medical antecedent the Board made 90 psychiatric diagnosis. This comprised of 25 out of the 56 who also had a medical antecedent and 65 out of the 199 who did not have a medical antecedent. Delusional disorder (43.3%) and schizophrenia (25.6%) are the most frequent diagnoses. Specializing and developing standards for determining the criminal responsibility of the elderly is required.


Assuntos
Envelhecimento/psicologia , Crime/estatística & dados numéricos , Criminosos/estatística & dados numéricos , Esquizofrenia Paranoide/epidemiologia , Idoso , Idoso de 80 Anos ou mais , Delusões , Feminino , Psiquiatria Legal/estatística & dados numéricos , Homicídio/estatística & dados numéricos , Humanos , Defesa por Insanidade , Masculino , Estudos Retrospectivos , Esquizofrenia Paranoide/psicologia , Turquia/epidemiologia
18.
J Fluoresc ; 21(2): 607-13, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20945079

RESUMO

The first use of electrospun nanofibrous materials as highly responsive fluorescence quenching-based optical CO(2) sensors is reported. Poly(methyl methacrylate) and ethyl cellulose were used as polymeric materials. Sensing slides were fabricated by electrospinning technique. A fiber-optic bundle was used for the gas detection. CO(2) sensors based on the change in the fluorescence signal intensity of ion pair form of 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS). The sensor slides showed high sensitivities due to the high surface area-to-volume ratio of the nanofibrous membrane structures. The preliminary results of Stern-Volmer analysis show that the sensitivities of electrospun nanofibrous membranes to detect CO(2) are 24 to 120 fold higher than those of the thin film based sensors. The response times of the sensing reagents were short and the signal changes were fully reversible. The stability of ion pair form of HPTS in the employed matrix materials was excellent and when stored in the ambient air of the laboratory there was no significant drift in signal intensity after 7 months. Our stability tests are still in progress.


Assuntos
Dióxido de Carbono/análise , Líquidos Iônicos/química , Nanofibras/química , Nanotecnologia , Fenômenos Ópticos , Absorção , Celulose/análogos & derivados , Celulose/química , Membranas Artificiais , Polimetil Metacrilato/química , Pirenos/síntese química , Pirenos/química , Ácidos Sulfônicos/síntese química , Ácidos Sulfônicos/química , Temperatura
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