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1.
Ned Tijdschr Tandheelkd ; 127(7-08): 434-440, 2020.
Artigo em Holandês | MEDLINE | ID: mdl-32840499

RESUMO

Many medications prescribed in the Netherlands have adverse effects on the oral mucosa. Adverse events often described are stomatitis, white lesions, abnormal pigmentation and sensibility disorders. Stomatitis is frequently observed in patients using medications for the treatment of malignancies or auto-immune diseases. Important causative classes of medicines are alkylating agents, anthracyclines, monoclonal antibodies, protein kinase inhibitors, purine derivatives, pyrimidine antagonists, taxanes and vinca alkaloids. White oral lesions often concern candidiasis and are frequently seen in patients using certain immunosuppressants and antibiotics. Abnormal pigmentation is frequently seen in patients using hydroxycarbamide, an antineoplastic agent. Sensibility disorders of the oral mucosa are described in several classes of medications, including protein kinase inhibitors. It is very important oral healthcare professionals can recognise possible adverse effects of medications on the oral mucosa. When it is probable an anomaly of the oral mucosa is caused by medication, the oral healthcare professional should contact the prescribing physician to discuss the possibility of adjusting or discontinuing the medication.


Assuntos
Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Úlceras Orais , Humanos , Mucosa Bucal , Países Baixos
2.
Ned Tijdschr Tandheelkd ; 126(1): 23-28, 2019 01.
Artigo em Holandês | MEDLINE | ID: mdl-30636262

RESUMO

Dental professionals will be confronted more frequently with medically compromised patients due to an increasing life expectancy in Western countries. The patients' systemic diseases and medication usage can both have consequences for oral health and dental treatment. It is often impossible to have all medical-dental interactions handy in the dental practice. To support the dental professional in providing safe healthcare, a tool has been developed. The medical-dental interactions scanner supports both patients and dental professionals in taking a patient's medical history and linking that information to the available literature. By that means, it is possible for the caregiver to provide patient-specific recommendations concerning possible adverse effects of medicaments,intra-oral manifestations of systemic diseases and measures to prevent medical emergencies.


Assuntos
Registros Eletrônicos de Saúde , Saúde Bucal , Equipe de Assistência ao Paciente , Assistência Odontológica , Humanos , Países Baixos
5.
Proc Natl Acad Sci U S A ; 114(18): 4597-4602, 2017 05 02.
Artigo em Inglês | MEDLINE | ID: mdl-28420793

RESUMO

The organic electronic ion pump (OEIP) provides flow-free and accurate delivery of small signaling compounds at high spatiotemporal resolution. To date, the application of OEIPs has been limited to delivery of nonaromatic molecules to mammalian systems, particularly for neuroscience applications. However, many long-standing questions in plant biology remain unanswered due to a lack of technology that precisely delivers plant hormones, based on cyclic alkanes or aromatic structures, to regulate plant physiology. Here, we report the employment of OEIPs for the delivery of the plant hormone auxin to induce differential concentration gradients and modulate plant physiology. We fabricated OEIP devices based on a synthesized dendritic polyelectrolyte that enables electrophoretic transport of aromatic substances. Delivery of auxin to transgenic Arabidopsis thaliana seedlings in vivo was monitored in real time via dynamic fluorescent auxin-response reporters and induced physiological responses in roots. Our results provide a starting point for technologies enabling direct, rapid, and dynamic electronic interaction with the biochemical regulation systems of plants.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Eletrônica , Ácidos Indolacéticos/farmacologia , Fenômenos Fisiológicos Vegetais/efeitos dos fármacos , Plantas Geneticamente Modificadas/crescimento & desenvolvimento , Plântula/crescimento & desenvolvimento , Arabidopsis/genética , Ácidos Indolacéticos/metabolismo , Bombas de Íon , Fenômenos Fisiológicos Vegetais/genética , Plantas Geneticamente Modificadas/genética , Plântula/genética
6.
Phys Med Biol ; 60(7): 2715-33, 2015 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-25768708

RESUMO

Cine MRI is a clinical reference standard for the quantitative assessment of cardiac function, but reproducibility is confounded by motion artefacts. We explore the feasibility of a motion corrected 3D left ventricle (LV) quantification method, incorporating multislice image registration into the 3D model reconstruction, to improve reproducibility of 3D LV functional quantification. Multi-breath-hold short-axis and radial long-axis images were acquired from 10 patients and 10 healthy subjects. The proposed framework reduced misalignment between slices to subpixel accuracy (2.88 to 1.21 mm), and improved interstudy reproducibility for 5 important clinical functional measures, i.e. end-diastolic volume, end-systolic volume, ejection fraction, myocardial mass and 3D-sphericity index, as reflected in a reduction in the sample size required to detect statistically significant cardiac changes: a reduction of 21-66%. Our investigation on the optimum registration parameters, including both cardiac time frames and number of long-axis (LA) slices, suggested that a single time frame is adequate for motion correction whereas integrating more LA slices can improve registration and model reconstruction accuracy for improved functional quantification especially on datasets with severe motion artefacts.


Assuntos
Algoritmos , Técnicas de Imagem de Sincronização Cardíaca/métodos , Imagem Cinética por Ressonância Magnética/métodos , Função Ventricular Esquerda , Adulto , Feminino , Humanos , Imageamento Tridimensional/métodos , Pessoa de Meia-Idade , Modelos Cardiovasculares , Movimento (Física)
7.
Clin Radiol ; 69(1): 63-71, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24156797

RESUMO

AIM: To investigate the capability and diagnostic accuracy of diffusion-weighted imaging (DWI) in differentiating benign from malignant breast lesions using 3 T magnetic resonance imaging (MRI). MATERIALS AND METHODS: Women with suspicious or indeterminate breast lesions detected at MRI, mammogram and/or ultrasound were recruited for dynamic contrast-enhanced (DCE)-MRI and DWI prior to their biopsy. Image fusion of DCE-MRI with apparent diffusion coefficient (ADC) map was utilized to select the region of interest (ROI) for ADC calculation in the area that showed the most avid enhancement. DWI was performed using two sets of b-values at 500 and 1000 s/mm(2), respectively. RESULTS: Fifty women were recruited and the final analysis comprised 44 breast lesions, 31 of which were malignant and 13 were benign. Significant results were obtained between ADC values of benign and malignant lesions (p < 0.001). The cut-off ADC values for benign and malignant lesions were 1.21 × 10(-3) mm(2)/s for b = 500 s/mm(2) and 1.22 × 10(-3) mm(2)/s for b = 1000 s/mm(2), respectively. The sensitivity of DCE-MRI alone was 100% with a specificity of 66.7%. When DCE-MRI was combined with b = 1000 s/mm(2), the specificity rose to 100%, while only mildly affecting sensitivity (90.6%). No significant correlation was found between ADC values and prognostic factors, such as lymph node metastasis, tumour size, oestrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) status, and tumour grades. CONCLUSION: The present study provides consistent evidence to support DWI as a diagnostic tool for breast lesion characterization. A combination of DCE-MRI with DWI is suggested to improve the sensitivity and specificity of lesion characterization.


Assuntos
Neoplasias da Mama/diagnóstico , Imagem de Difusão por Ressonância Magnética/métodos , Adulto , Idoso , Meios de Contraste , Diagnóstico Diferencial , Feminino , Gadolínio DTPA , Humanos , Metástase Linfática , Mamografia , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Sensibilidade e Especificidade , Ultrassonografia Mamária
8.
Clin Radiol ; 68(9): e502-10, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23706826

RESUMO

AIM: To investigate the diagnostic accuracy of single-voxel proton magnetic resonance spectroscopy (SV (1)H MRS) by quantifying total choline-containing compounds (tCho) in differentiating malignant from benign lesions, and subsequently, to analyse the relationship of tCho levels in malignant breast lesions with their histopathological subtypes. MATERIALS AND METHODS: A prospective study of SV 1H MRS was performed following dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in 61 women using a 3 T MR system. All lesions (n = 57) were analysed for characteristics of morphology, contrast-enhancement kinetics, and tCho peak heights at SV (1)H MRS that were two-times above baseline. Subsequently, the tCho in selected lesions (n = 32) was quantified by calculating the area under the curve, and a tCho concentration equal to or greater than the cut-off value was considered to represent malignancy. The relationship between tCho in invasive ductal carcinomas (IDCs) and their Bloom & Richardson grading of malignancy was assessed. RESULTS: Fifty-two patients (57 lesions; 42 malignant and 15 benign) were analysed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV), of predicting malignancy were 100, 73.3, 91.3, and 100%, respectively, using DCE-MRI and 95.2, 93.3, 97.6, and 87.5%, respectively, using SV (1)H MRS. The tCho cut-off for receiver operating characteristic (ROC) curve was 0.33 mmol/l. The relationship between tCho levels in malignant breast lesions with their histopathological subtypes was not statistically significant (p = 0.3). CONCLUSION: Good correlation between tCho peaks and malignancy, enables SV (1)H MRS to be used as a clinically applicable, simple, yet non-invasive tool for improved specificity and diagnostic accuracy in detecting breast cancer.


Assuntos
Neoplasias da Mama/diagnóstico , Carcinoma Ductal de Mama/diagnóstico , Prótons , Adulto , Idoso , Idoso de 80 Anos ou mais , Mama/química , Colina/análise , Detecção Precoce de Câncer/métodos , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Espectroscopia de Ressonância Magnética/métodos , Pessoa de Meia-Idade , Estudos Prospectivos , Sensibilidade e Especificidade , Adulto Jovem
9.
Artigo em Inglês | MEDLINE | ID: mdl-23542669

RESUMO

Analytical procedures for the determination of tramadol (T), O-desmethyltramadol (ODT), and N-desmethyltramadol (NDT) in human urine have been developed and validated using gas chromatography-mass spectrometry (GC/MS). Sample preparation involved liquid-liquid extraction with methyl-tert-butyl ether (MTBE) and followed by back extraction with 0.1 M hydrochloric acid. Proadifen (SKF525A) was selected as internal standard (IS). Extraction efficiencies of T, ODT and NDT were 102.12, 101.30, and 98.21%, respectively. The calibration curves were linear (r(2)>0.99) in the concentration range 10-1000 ng/mL for all compounds. Limits of quantification (LOQ) were 10, 10 and 20 ng/mL for T, ODT and NDT, respectively. Intra-assay precision was within 1.29-6.48% and inter-assay precision was within 1.28-6.84% for T, ODT and NDT. Intra-assay accuracy was within 91.79-106.89% for all analytes. This method detected urine concentrations of T, ODT and NDT in six healthy volunteers for 7 days after administration of 50 mg oral doses of tramadol.


Assuntos
Analgésicos Opioides/urina , Cromatografia Gasosa-Espectrometria de Massas/métodos , Tramadol/análogos & derivados , Tramadol/urina , Analgésicos Opioides/química , Humanos , Limite de Detecção , Padrões de Referência , Reprodutibilidade dos Testes , Tramadol/química
10.
BMJ Open ; 2(4)2012.
Artigo em Inglês | MEDLINE | ID: mdl-22855630

RESUMO

INTRODUCTION: At present, physicians have a limited ability to predict major cardiovascular complications after non-cardiac surgery and little is known about the anatomy of coronary arteries associated with perioperative myocardial infarction. We have initiated the Coronary CT Angiography (CTA) VISION Study to (1) establish the predictive value of coronary CTA for perioperative myocardial infarction and death and (2) describe the coronary anatomy of patients that have a perioperative myocardial infarction. METHODS AND ANALYSIS: The Coronary CTA VISION Study is prospective observational study. Preoperative coronary CTA will be performed in 1000-1500 patients with a history of vascular disease or at least three cardiovascular risk factors who are undergoing major elective non-cardiac surgery. Serial troponin will be measured 6-12 h after surgery and daily for the first 3 days after surgery. Major vascular outcomes at 30 days and 1 year after surgery will be independently adjudicated. ETHICS AND DISSEMINATION: Coronary CTA results in a measurable radiation exposure that is similar to a nuclear perfusion scan (10-12 mSV). Treating physicians will be blinded to the CTA results until 30 days after surgery in order to provide the most unbiased assessment of its prognostic capabilities. The only exception will be the presence of a left main stenosis >50%. This approach is supported by best available current evidence that, excluding left main disease, prophylatic revascularisation prior to non-cardiac surgery does not improve outcomes. An external safety and monitoring committee is overseeing the study and will review outcome data at regular intervals. Publications describing the results of the study will be submitted to major peer-reviewed journals and presented at international medical conferences.

11.
Singapore Med J ; 52(11): e232-5, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22173263

RESUMO

A 62 year-old woman who presented with an atraumatic acute abdomen was discovered to have haemoperitoneum with splenic rupture on urgent computed tomography and was immediately referred for life-saving emergency splenectomy. Histopathological examination revealed secondary splenic amyloidosis. The patient was later found to be suffering from infective endocarditis secondary to her permanent cardiac pacemaker. This report describes a patient who could have suffered from a long-standing infected vegetation on a permanent cardiac pacemaker, which led to splenic amyloidosis and spontaneous splenic rupture.


Assuntos
Amiloidose/diagnóstico , Endocardite/diagnóstico , Ruptura Esplênica/diagnóstico , Amiloidose/etiologia , Infecções por Corynebacterium/metabolismo , Endocardite/microbiologia , Feminino , Humanos , Pessoa de Meia-Idade , Marca-Passo Artificial/efeitos adversos , Baço/patologia , Baço/cirurgia , Esplenectomia/métodos , Ruptura Esplênica/etiologia , Esplenomegalia/microbiologia , Tomografia Computadorizada por Raios X/métodos
12.
Int J Clin Pharmacol Ther ; 49(12): 709-12, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22122812

RESUMO

AIM: Chemotherapy-induced nausea and vomiting (CINV) is not understood completely. The aim of this study is to investigate the effects of smoking on CINV. METHODS: 121 consecutive patients who received cisplatin (≥ 50 mg/m²) based chemotherapy were included in the study. The patients who reported motion sickness, pain, emesis during past pregnancy, emesis history of previous chemotherapy, with Karnofsky score < 70, peptic ulcer, gastroesophageal reflux, migraine, central nervous system metastasis and patients scheduled to receive radiation therapy were excluded from the study. A standard antiemetic treatment was given to all patients. The nausea and vomiting was assessed by the European Organization for the Research and Treatment of Cancer Quality of Life Questionnaire. After first cycle of chemotherapy, Grade 2 - 3 nausea and vomiting were questioned. RESULTS: Grade 2 - 3 nausea and vomiting was higher in non-smokers (p < 0.001). We found that nausea and vomiting in women is more frequent than in men (p < 0.001). CONCLUSION: In our study we found that smokers had a lower incidence of CINV. Further investigations are needed to confirm the findings of this pilot study.


Assuntos
Antineoplásicos/efeitos adversos , Náusea/induzido quimicamente , Fumar , Vômito/induzido quimicamente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/prevenção & controle , Estudos Prospectivos , Vômito/prevenção & controle
13.
Ned Tijdschr Geneeskd ; 152(44): 2425-9, 2008 Nov 01.
Artigo em Holandês | MEDLINE | ID: mdl-19055144

RESUMO

OBJECTIVE: To determine, in people who participated in the Netherlands Heart Foundation's National Cholesterol Test in supermarkets, risk factors for cardiovascular disease and expectations concerning the test result using a questionnaire, and to compare their cholesterol levels with reference values. DESIGN: Descriptive study and questionnaire survey. METHOD: Participants who underwent the National Cholesterol Test in 9 supermarkets during the summer of 2007 were invited to complete a short questionnaire about risk factors for cardiovascular disease and expectations concerning the test result. Statements about the intention to change behaviour were offered, and the measured total cholesterol level was recorded. RESULTS: The average age of the 684 respondents was 57 years (SD: 16); 72% were female. Participants had on average a lower risk of cardiovascular disease than the general population; they suffered less frequently from diabetes, hypertension and being overweight, and smoked less. The measured cholesterol level was 5.0-6.5 mmol/l in 37% and > 6.5 mmoll in 11%. Elevated cholesterol levels were less common in this group than in the general population. The intention to change behaviour was substantial. CONCLUSION: The results of this study showed that the National Cholesterol Test reached relatively many healthy, somewhat worried people. The intention to change behaviour was substantial.


Assuntos
Colesterol/sangue , Comportamentos Relacionados com a Saúde , Hipercolesterolemia/diagnóstico , Doenças Cardiovasculares/epidemiologia , Diabetes Mellitus Tipo 2/epidemiologia , Feminino , Humanos , Hipercolesterolemia/sangue , Hipercolesterolemia/epidemiologia , Hipertensão/epidemiologia , Masculino , Pessoa de Meia-Idade , Países Baixos/epidemiologia , Obesidade/epidemiologia , Valores de Referência , Fatores de Risco , Inquéritos e Questionários , Tabagismo/epidemiologia
14.
Br J Radiol ; 78(931): 596-600, 2005 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15961840

RESUMO

The objective of this study was to prospectively determine the incidence of venous thrombosis (VT) in the upper limbs in patients with peripherally inserted central catheters (PICC). We prospectively investigated the incidence of VT in the upper limbs of 26 patients who had PICC inserted. The inclusion criteria were all patients who had a PICC inserted, whilst the exclusion criterion was the inability to perform a venogram (allergies, previous contrast medium reaction and inability of gaining venous access). Both valved and non-valved catheters were evaluated. Prior to removal of the PICC, an upper limb venogram was performed. The number of segments involved with VT were determined. The duration of central venous catheterization was classified as; less than 6 days, between 6 days and 14 days and more than 14 days. VT was confirmed in 38.5% (10/26) of the patients. The majority 85.7% (12/14) were complete occlusive thrombi and the majority of VT only involved one segment. There was no statistical correlation between the site of insertion of the PICC and the location of VT. Neither was there any observed correlation between the occurrence of VT with the patient's history of hypertension, hypercholesterolaemia, coronary artery disease, diabetes mellitus, cardiac insufficiency, smoking or cancer. There was also no statistical correlation with the size of the catheter. In conclusion, PICCs are associated with a significant risk of upper extremity deep vein thrombosis (UEVT).


Assuntos
Braço/irrigação sanguínea , Cateterismo Venoso Central/efeitos adversos , Trombose Venosa/etiologia , Adolescente , Adulto , Idoso , Cateterismo Venoso Central/instrumentação , Cateterismo Venoso Central/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Flebografia , Estudos Prospectivos , Fatores de Tempo , Trombose Venosa/diagnóstico por imagem
15.
Anal Sci ; 21(6): 595-614, 2005 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15984192

RESUMO

Articles about the development of derivative spectrophotometric methods and analytical applications of derivative spectrophotometry (DS) published in the last nine years (since 1994) are reviewed.

16.
J Pharm Biomed Anal ; 30(4): 1087-92, 2002 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-12408899

RESUMO

A simple 19F NMR spectrometric method was proposed for the determination of the partition coefficients of fluorinated psychotropic drugs, trifluoperazine (TFPZ), flunitrazepam (FNZ) and flurazepam (FZ) between phosphatidylcholine (PC) bilayer of small unilamellar vesicles (SUVs) and water (buffer). Each 19F NMR spectrum of these drugs in the presence of PC SUV showed a single signal accompanying a PC concentration-depending shift change and broadening, which indicated a fast exchange of these drugs between the water phase and the PC bilayer of SUV. From the relationship between the 19F chemical shift change (Deltadelta) of each drug and the PC concentration, the molar partition coefficients (K(p)'s) were calculated and obtained with a good precision of RSD below 6%. The fractions of the partitioned drugs calculated by using the obtained K(p)-values were in a good agreement with the experimental values. The results demonstrate that the 19F NMR method can be usefully applied to the determination of partition coefficients of many drugs having fluorine atom(s) without any separation procedure, especially for drugs which do not have absorption in the ultraviolet or visible region, or those having absorption but show insignificant spectral changes according to their incorporation to PC bilayers (e.g. FNZ).


Assuntos
Espectroscopia de Ressonância Magnética/métodos , Fosfatidilcolinas/metabolismo , Psicotrópicos/análise , Psicotrópicos/farmacocinética , Flúor/análise , Flúor/farmacocinética , Bicamadas Lipídicas/metabolismo , Lipossomos , Psicotrópicos/química , Água/metabolismo
17.
Vet Immunol Immunopathol ; 80(1-2): 131-42, 2001 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-11445224

RESUMO

A total of 14 antibodies were found to label resting and/or activated swine platelets. Six recognized CD previously characterized for swine (CD29, CD41/61 and CD46). One had been characterized for human cells (CD47). Two antibodies with CD14 and SLA class I specificity suggested by the donor as well as five blind antibodies were also positive on platelets. One antibody appeared to recognize the swine homologue to human CD47, and four remained unclustered.


Assuntos
Plaquetas/imunologia , Suínos/imunologia , Animais , Anticorpos Monoclonais , Especificidade de Anticorpos , Antígenos CD , Citometria de Fluxo , Humanos , Especificidade da Espécie
18.
Med J Malaysia ; 50(1): 64-71, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7752979

RESUMO

Specific human papillomavirus (HPV) types have been implicated in the development of cervical carcinoma worldwide. Novel molecular techniques have facilitated the detection and typing of HPV in cervical lesions. DNA preparations from a series of 23 histopathologically confirmed cervical carcinoma patients were analyzed by polymerase chain reaction (PCR) using degenerate primers for the presence of HPV DNA sequences. A total of 22 of 23 cases studied (95.7%) were found positive for HPV DNA sequences. Further studies by DNA hybridization with viral specific probe and restriction enzyme analysis demonstrated the presence of HPV 16 in 73.9% (17/23) and HPV 18 in 65.2% (15/23) of the cases examined. Interestingly, the uncommon HPV 31 and 33 were also found but with a lower percentage (16.9%). It was noted that HPV 16 frequency in the carcinoma increased with age but HPV 18 was evenly present at all ages investigated. We found that HPV was frequently associated with the majority of the cervical carcinomas, and in all but one case, oncogenic high risk HPV genotypes were present. We conclude that HPV infection of the genital tract has an important role in the development of the disease in Malaysia.


Assuntos
Carcinoma/virologia , Papillomaviridae/classificação , Papillomaviridae/isolamento & purificação , Reação em Cadeia da Polimerase , Mapeamento por Restrição , Neoplasias do Colo do Útero/virologia , Sequência de Bases , Feminino , Humanos , Sondas Moleculares/genética , Dados de Sequência Molecular
19.
BMJ ; 306(6884): 1038-41, 1993 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-8490498

RESUMO

OBJECTIVE: To assess the ability of clinicians to recognise deaths which require referral to the coroner. DESIGN: Postal questionnaire consisting of 16 fictitious case histories, 14 of which contained a clear indication for referral to the coroner. SETTING: Large teaching hospital. Coroner's office. SUBJECTS: 200 clinicians from general medical and surgical firms and senior staff of the local coroner's office (two coroner's officers and the two deputy coroners). MAIN OUTCOME MEASURES: Number of correct assessments on questionnaire. RESULTS: The mean recognition score for the clinicians was 9.11 (range 3-14) with no difference between the clinical grades. All of the coroner's senior staff recorded maximum recognition scores of 16. CONCLUSIONS: The study highlights several features of the coronial system which are poorly understood by clinicians and provides the basis for an initiative to improve the medicolegal education of all clinicians.


Assuntos
Causas de Morte , Médicos Legistas , Corpo Clínico Hospitalar , Competência Profissional , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Encaminhamento e Consulta , Inquéritos e Questionários
20.
Int J Rad Appl Instrum A ; 39(5): 439-40, 1988.
Artigo em Inglês | MEDLINE | ID: mdl-2840420

RESUMO

The utility of a phantom material, based on SMR(L) [Standard Malaysian Rubber] grade natural rubber and a formulation used for the proprietary rubber phantom-material, Temex, has been examined for the 1-MeV photon-Measurement has also been performed with 60-keV photons using the radionuclide 241Am. At photon-therapy energy levels the measured response, when compared with tabulated central-axis percentage depth doses for the defined measuring conditions, produces everywhere (in the range 1-19 cm depth) better than 2% deviation. The favourable measured response characteristics combined with the ease of processing and casting the phantom material provide the basis for useful radiotherapy machine calibration and anthropomorphic dosimetry measurements. The measured mass-attenuation coefficient, at 60keV, of 0.204 cm2 g-1 (+/- 3%) is in close agreement with tabulated values for water (0.2055 cm2 g-1).


Assuntos
Modelos Estruturais , Dosagem Radioterapêutica , Borracha , Radioisótopos de Cobalto , Raios gama , Humanos
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