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1.
Rev Sci Instrum ; 92(6): 064101, 2021 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243508

RESUMO

With the aim of improving phototherapy for neonatal jaundice (hyperbilirubinemia), this study investigates the degradation of unconjugated bilirubin under irradiance by conventional light and by white, red, green, and blue LED sources in vitro. The absorption spectra of bilirubin under these different light sources are compared. The results demonstrate that white LED phototherapy promotes more efficient bilirubin degradation than conventional blue-light therapy. This study provides a basis for the design of novel phototherapy devices for the treatment of hyperbilirubinemia.


Assuntos
Icterícia Neonatal , Fototerapia , Bilirrubina , Humanos , Recém-Nascido , Luz
2.
Med Eng Phys ; 35(1): 140-4, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22959619

RESUMO

In this paper, we report our experimental design in searching a smart and easy-to-read dosimeter used to detect 6 MV X-rays for improving patient safety in radiation oncology. The device was based on an organic emissive solutions of poly(2-methoxy-5(2'-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV), aluminum-tris-(8-hydroxyquinoline) (Alq3) and additive components which were characterized by UV-Vis absorption, photoluminescence and CIE color coordinate diagram. The optical properties of MEH-PPV/Alq3 solutions have been examined as function of radiation dose over the range of 0-100 Gy. It has shown that MEH-PPV/Alq3 solutions are specifically sensitive to X-rays, since the effect of radiation on this organic system is strongly correlated with the efficient spectral overlap between Alq3 emission and the absorption of degraded MEH-PPV, which alters the color and photoemission of MEH-PPV/Alq3 mixtures from red to yellow, and then to green. The rate of this change is more sensitive when MEH-PPV/Alq3 is irradiated in the presence of benzoyl peroxide than when in the presence of hindered phenolic stabilizers, respectively, an accelerator and an inhibitor to activate or inhibit free radical formation. This gives rise to optimize the response curve of the dosimeter. It is clear from the experimental results that organic emissive semiconductors have potential to be used as dedicated and low-cost dosimeters to provide an independent check of beam output of a linear accelerator and therefore to give patients the opportunity to have information on the dose prescription or equipment-related problems a few minutes before being exposed to radiation.


Assuntos
Acidentes , Compostos Organometálicos/química , Polímeros/química , Lesões por Radiação/prevenção & controle , Radioterapia (Especialidade)/instrumentação , Radiometria/instrumentação , Compostos de Vinila/química , Peróxido de Benzoíla/química , Humanos , Fenômenos Ópticos , Fenóis/química , Doses de Radiação , Radioterapia (Especialidade)/economia , Radiometria/economia , Risco , Raios X/efeitos adversos
3.
Med Phys ; 36(2): 642-4, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19292005

RESUMO

Optical absorption and fluorescence measurements have been done on poly[2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene]/[aluminum-tris(8-hydroxyquinoline)] solutions. The authors show that there is a visible response that covers the electronic absorption of bilirubin (350-500 nm), and hence, this material is applicable for managing the radiation doses planning before treatment of jaundice of neonates, which is one of the most common reasons of hospital readmission of newborns infants. The results show that the material presents a gradation of color from orange to yellow clearly, while its peak position emission shifts from orange-red (lambda(max) = 571 nm) to green (lambda(max) = 540 nm) with the radiation exposure time. The rate of these changes can be altered by manipulations of organic solution concentration and they are usually slow (from 2 to 8 h), suggesting these color and emission changes can be used to design an easy to make, easy to read, easy to operate, low cost (< US $0.50) and accuracy for individual monitoring indicator dosimeter in order to represent easily the radiation exposure time usually used in management of neonatal jaundice.


Assuntos
Luz , Radiometria/métodos , Absorção , Cor , Humanos , Hidroxiquinolinas/química , Recém-Nascido , Icterícia Neonatal/terapia , Fototerapia , Polivinil/química , Doses de Radiação , Espectrometria de Fluorescência , Fatores de Tempo
4.
Eur J Pediatr Surg ; 18(5): 307-12, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19051398

RESUMO

AIM: The aim of the study was to review our experience in the management of newborns with congenital diaphragmatic hernia (CDH). METHODS: A retrospective study including all infants with CDH at the Hospital de São João, a center that does not provide ECMO support, for the period from 1997 to 2006. Since 2003, a new treatment protocol has been used. RESULTS: There were 61 newborns (30 male/31 female) with a birth weight of 2800 g (880 - 3770), and a gestational age of 38 weeks (28 - 41); 46 (75 %) were inborn and 42 (69 %) had a prenatal diagnosis of CDH. There were 2 (3 %) chromosomal anomalies, 3 (5 %) with other congenital anomalies and 1 (2 %) with nonimmune hydrops fetalis. The diaphragmatic defect was left sided in 55 (90 %) cases. Corrective surgery was performed in 43 (70 %) patients. New therapies were used: HFOV 13 % (n = 8); inhaled nitric oxide 13 % (n = 8); and sildenafil 7 % (n = 4). We found that systemic arterial hypotension (p = 0.001), the severity of pulmonary hypertension (p = 0.001), prenatal diagnosis (p = 0.006), birth weight (p = 0.022), female gender (p = 0.029), inborn birth (p = 0.030), arterial pH < 7.35 at admission (p = 0.030), right-sided defect (p = 0.033) and pneumothorax (p = 0.033) to be predictive of mortality. The overall survival rate was 43 % (n = 26), and since 2003 this rate has improved to 61 % for term neonates without other congenital or chromosomal anomalies. CONCLUSIONS: Our survival rate for infants with CDH has improved over the last ten years, and this improvement is associated with the use of new therapies such as HFOV, inhaled nitric oxide and sildenafil.


Assuntos
Procedimentos Cirúrgicos do Sistema Digestório/métodos , Hérnias Diafragmáticas Congênitas , Feminino , Seguimentos , Refluxo Gastroesofágico/epidemiologia , Refluxo Gastroesofágico/etiologia , Hérnia Diafragmática/complicações , Hérnia Diafragmática/cirurgia , Humanos , Recém-Nascido , Masculino , Morbidade/tendências , Portugal/epidemiologia , Recidiva , Doenças Respiratórias/epidemiologia , Doenças Respiratórias/etiologia , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo
5.
Eur J Pediatr Surg ; 18(4): 219-23, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18704887

RESUMO

AIM: The aim of the study was to review our experience in the management of newborns with congenital diaphragmatic hernia (CDH). METHODS: A retrospective study including all infants with CDH at the Hospital de São João, a center that does not provide ECMO support, for the period from 1997 to 2006. Since 2003, a new treatment protocol has been used. RESULTS: There were 61 newborns (30 male/31 female) with a birth weight of 2800 g (880 - 3770), and a gestational age of 38 weeks (28 - 41); 46 (75 %) were inborn and 42 (69 %) had a prenatal diagnosis of CDH. There were 2 (3 %) chromosomal anomalies, 3 (5 %) with other congenital anomalies and 1 (2 %) with nonimmune hydrops fetalis. The diaphragmatic defect was left sided in 55 (90 %) cases. Corrective surgery was performed in 43 (70 %) patients. New therapies were used: HFOV 13 % (n = 8); inhaled nitric oxide 13 % (n = 8); and sildenafil 7 % (n = 4). We found that systemic arterial hypotension (p = 0.001), the severity of pulmonary hypertension (p = 0.001), prenatal diagnosis (p = 0.006), birth weight (p = 0.022), female gender (p = 0.029), inborn birth (p = 0.030), arterial pH < 7.35 at admission (p = 0.030), right-sided defect (p = 0.033) and pneumothorax (p = 0.033) to be predictive of mortality. The overall survival rate was 43 % (n = 26), and since 2003 this rate has improved to 61 % for term neonates without other congenital or chromosomal anomalies. CONCLUSIONS: Our survival rate for infants with CDH has improved over the last ten years, and this improvement is associated with the use of new therapies such as HFOV, inhaled nitric oxide and sildenafil.


Assuntos
Hérnia Diafragmática/cirurgia , Feminino , Hérnia Diafragmática/diagnóstico , Hérnia Diafragmática/mortalidade , Hérnias Diafragmáticas Congênitas , Humanos , Recém-Nascido , Masculino , Piperazinas/uso terapêutico , Purinas/uso terapêutico , Estudos Retrospectivos , Citrato de Sildenafila , Sulfonas/uso terapêutico , Vasodilatadores/uso terapêutico
6.
Am J Gastroenterol ; 85(2): 178-80, 1990 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2301340

RESUMO

We present here an unusual case of a pancreatic gastrinoma that caused recurrent episodes of clinical pancreatitis secondary to complete obstruction of the main pancreatic duct. The patient did not manifest signs or symptoms of peptic ulcer disease.


Assuntos
Gastrinoma/diagnóstico , Neoplasias Pancreáticas/diagnóstico , Pancreatite/diagnóstico , Adulto , Doença Crônica , Diagnóstico Diferencial , Gastrinoma/patologia , Gastrinoma/cirurgia , Humanos , Masculino , Pâncreas/patologia , Pancreatectomia , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/cirurgia , Pancreatite/patologia , Recidiva
7.
J Med Educ ; 54(11): 856-62, 1979 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-501716

RESUMO

A cost containment program initiated in 1975 on the medical teaching service of an 890-bed university affiliated hospital has led to a significant improvement in house staff utilization of facilities and procedures. During the first three and one-half years of the program the average length of stay on the general medical service was reduced by 21 percent; and the cost per admission rose at a rate of only 4.3 percent per annum, while the cost per admission on other services rose at an average rate of 14.5 percent per year. In the outpatient setting eliminating unnecessary laboratory procedures resulted in an actual reduction in patient-encounter cost initiated by interns despite price increases on all procedures. Overall cost advantage gained by reduction in utilization will rapidly be negated, however, if the current rate of inflation continues.


Assuntos
Controle de Custos , Corpo Clínico Hospitalar/educação , Hospitais com mais de 500 Leitos , Hospitais Universitários , Tempo de Internação/economia , North Carolina , Ambulatório Hospitalar/economia
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