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1.
Med J Malaysia ; 77(3): 313-319, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35638487

RESUMO

BACKGROUND: Acute illness and hospitalisation detriment the nutritional status of older patients. This study aimed to describe the prevalence of malnutrition, characteristics and in-hospital outcomes associated with malnutrition, and nutritional management among patients who were admitted to the Subacute Geriatric Ward. METHODS: This is a retrospective study of older patients (age ≥ 60) who were admitted to the Subacute Geriatric Ward of Kuala Lumpur Hospital from 1 March 2021 to 31 May 2021. Malnutrition was identified using the Mini Nutritional Assessment-Short Form (MNA-SF). The in-hospital outcomes evaluated were hospital-associated complications, namely delirium, functional decline, incontinence, inpatient falls, inpatient pressure injuries, hospital-acquired infection, institutionalisation, and inpatient mortality. RESULTS: Seventy-three patients were included (mean age 74.7, female 58.9%), of which 28 (38.4%) and 27 (37.0%) were malnourished and at risk of malnutrition, respectively. Poorer nutritional status was associated with increased age, comorbidity burden, frailty, immobility, impaired basic activities of daily living, history of falls, cognitive impairment, incontinence, and arthritis. About 71.2% and 60.3% of patients were offered dietitian review and oral nutritional supplements, respectively. The in-hospital outcome rates were higher among malnourished patients, but the differences were not statistically significant. However, multiple hospital-associated complications were more common with poorer nutritional status (p = 0.018). CONCLUSION: Hospital malnutrition is prevalent among older patients, and unidentified malnutrition is not justified due to its association with multiple adverse outcomes.


Assuntos
COVID-19 , Desnutrição , Atividades Cotidianas , Idoso , COVID-19/epidemiologia , Estudos Transversais , Feminino , Avaliação Geriátrica , Hospitalização , Humanos , Malásia/epidemiologia , Desnutrição/complicações , Desnutrição/epidemiologia , Pandemias , Estudos Retrospectivos , Centros de Atenção Terciária
2.
Osteoporos Int ; 32(5): 921-926, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33170309

RESUMO

Integration of a vertebral fracture identification service into a Fracture Liaison Service is possible. Almost one-fifth of computerised tomography scans performed identified an individual with a fracture. This increase in workload needs to be considered by any FLS that wants to utilise such a service. INTRODUCTION: This service improvement project aimed to improve detection of incidental vertebral fractures on routine imaging. It embedded a vertebral fracture identification service (Optasia Medical, OM) on routine computerised tomography (CT) scans performed in this hospital as part of its Fracture Liaison Service (FLS). METHODS: The service was integrated into the hospital's CT workstream. Scans of patients aged ≥ 50 years for 3 months were prospectively retrieved, alongside their clinical history and the CT report. Fractures were identified via OM's machine learning algorithm and cross-checked by the OM radiologist. Fractures identified were then added as an addendum to the original CT report and the hospital FLS informed. The FLS made recommendations based on an agreed algorithm. RESULTS: In total, 4461 patients with CT scans were retrieved over the 3-month period of which 850 patients had vertebra fractures identified (19.1%). Only 49% had the fractures described on hospital radiology report. On average, 61 patients were identified each week with a median of two fractures. Thirty-six percent were identified by the FLS for further action and recommendations were made to either primary care or the community osteoporosis team within 3 months of fracture detection. Of the 64% not identified for further action, almost half was because the CT was part of cancer assessment or treatment. The remaining were due to a combination of only ≤ 2 mild fractures; already known to a bone health specialist; in the terminal stages of any chronic illness; significant dependency for activities of daily living; or a life expectancy of less than 12 months CONCLUSION: It was feasible to integrate a commercial vertebral fracture identification service into the daily working of a FLS. There was a significant increase in workload which needs to be considered by any future FLS planning to incorporate such a service into their clinical practice.


Assuntos
Osteoporose , Fraturas por Osteoporose , Fraturas da Coluna Vertebral , Atividades Cotidianas , Idoso , Humanos , Fraturas por Osteoporose/diagnóstico por imagem , Melhoria de Qualidade , Prevenção Secundária , Fraturas da Coluna Vertebral/diagnóstico por imagem , Fraturas da Coluna Vertebral/etiologia
3.
Nature ; 495(7439): 103-6, 2013 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-23395958

RESUMO

Post-transcriptional switches are flexible effectors of dynamic changes in gene expression. Here we report a new post-transcriptional switch that dictates the spatiotemporal and mutually exclusive expression of two alternative gene products from a single transcript. Expression of primate-specific exonic microRNA-198 (miR-198), located in the 3'-untranslated region of follistatin-like 1 (FSTL1) messenger RNA, switches to expression of the linked open reading frame of FSTL1 upon wounding in a human ex vivo organ culture system. We show that binding of a KH-type splicing regulatory protein (KSRP, also known as KHSRP) to the primary transcript determines the fate of the transcript and is essential for the processing of miR-198: transforming growth factor-ß signalling switches off miR-198 expression by downregulating KSRP, and promotes FSTL1 protein expression. We also show that FSTL1 expression promotes keratinocyte migration, whereas miR-198 expression has the opposite effect by targeting and inhibiting DIAPH1, PLAU and LAMC2. A clear inverse correlation between the expression pattern of FSTL1 (pro-migratory) and miR-198 (anti-migratory) highlights the importance of this regulatory switch in controlling context-specific gene expression to orchestrate wound re-epithelialization. The deleterious effect of failure of this switch is apparent in non-healing chronic diabetic ulcers, in which expression of miR-198 persists, FSTL1 is absent, and keratinocyte migration, re-epithelialization and wound healing all fail to occur.


Assuntos
Proteínas Relacionadas à Folistatina/genética , Regulação da Expressão Gênica/genética , MicroRNAs/genética , RNA Mensageiro/genética , Transcrição Gênica/genética , Cicatrização/genética , Proteínas Adaptadoras de Transdução de Sinal/antagonistas & inibidores , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Movimento Celular , Pé Diabético/genética , Pé Diabético/metabolismo , Pé Diabético/patologia , Éxons/genética , Proteínas Relacionadas à Folistatina/biossíntese , Forminas , Humanos , Técnicas In Vitro , Queratinócitos/citologia , Queratinócitos/metabolismo , Laminina/antagonistas & inibidores , Laminina/metabolismo , Fases de Leitura Aberta/genética , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Pele/citologia , Pele/lesões , Pele/metabolismo , Pele/patologia , Fatores de Tempo , Transativadores/genética , Transativadores/metabolismo , Fator de Crescimento Transformador beta1/metabolismo , Ativador de Plasminogênio Tipo Uroquinase/antagonistas & inibidores , Ativador de Plasminogênio Tipo Uroquinase/metabolismo
4.
Water Sci Technol ; 76(3-4): 623-632, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28759444

RESUMO

In this paper, the effect of suspended flocs on the tailing of ultraviolet (UV) disinfection kinetics of secondary effluents was examined. To achieve this goal, final effluents produced in two processes for treating wastewater; namely, a trickling filter system and an activated sludge system, were collected and their UV disinfection were compared. Tailing of the UV dose response curve was controlled by the fraction of flocs that are both culturable and UV-resistant, referred to as the 'tailing propensity'. Using this parameter, the contribution of various floc size fractions in reducing the UV disinfection efficiency of wastewater samples was quantified. Activated sludge flocs larger than 125 µm exhibited as much as 35 times greater tailing propensity than smaller flocs in the range of 20-25 µm. Within a fixed size range, the tailing propensity of flocs generated in the trickling filter system was 3 to 8 times higher than that of activated sludge flocs, and this difference increased with the floc size. A mathematical model was developed to predict the UV disinfection of secondary effluents from suspended particle size distribution data. The model showed good agreement with experimental results.


Assuntos
Esgotos/microbiologia , Raios Ultravioleta , Águas Residuárias/microbiologia , Desinfecção/métodos , Cinética , Tamanho da Partícula , Eliminação de Resíduos Líquidos/métodos
5.
Appl Radiat Isot ; 204: 111109, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38029636

RESUMO

The goal of this study is to provide a benchmark for the use of Monte Carlo simulation when applied to coincidence summing corrections. The examples are based on simple geometries: two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The coincidence corrective factors are computed for four radionuclides. The exercise input files and calculation results with practical recommendations are made available for new users on a dedicated webpage.

6.
Appl Radiat Isot ; 201: 110993, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37651916

RESUMO

Atomic and nuclear data represent an important input for the accuracy of primary activity measurements based on liquid scintillation. In particular, the reliability of ß-spectrum computation has been investigated for several years through experimental and theoretical studies providing solid evidence for the need to consider the atomic effects. In the present study, the activity standardization of two ß-emitting radionuclides (60Co, 106Ru/106Rh) was carried out by means of the 4πß-γ coincidence and Triple-to-Double Coincidence Ratio (TDCR) methods. The comparison between the activity concentrations given by both primary techniques presents new evidence that a better agreement is obtained when the exchange and screening effects are included in the ß-spectra implemented in the model of light emission for TDCR measurements. A new development of a stochastic model based on Geant4 simulations for TDCR calculations is also presented.

7.
Arch Plast Surg ; 50(4): 370-376, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37564709

RESUMO

Background The posterior ledge (PL) is a vital structure that supports the implant posteriorly during orbital floor reconstruction. This study describes a technique for mapping the PL in relation to the infraorbital margin (IM) in patients with orbital floor blowout fractures. This study establishes the location of the optic foramen in relation to the PL. Methods Facial computed tomography (FCT) scans of 67 consecutive patients with isolated orbital floor blowout fractures were analyzed using Osirix. Planes of reference for orbital fractures, a standardized technique for performing measurements on FCT, was used. Viewed coronally, the orbit was divided into seven equal sagittal slices (L1 laterally to L7 medially) with reference to the midorbital plane. The distances of PL from IM and location of optic foramen were determined. Results The greatest distance to PL is found at L5 (median: 30.1 mm, range: 13.5-37.1 mm). The median and ranges for each slice are as follows: L1 (median: 0.0 mm, range: 0.0-19.9 mm), L2 (median: 0.0 mm, range: 0.0-21.5 mm), L3 (median: 15.8 mm, range: 0.0-31.7 mm), L4 (median: 26.1 mm, range: 0.0-34.0 mm), L5 (median: 30.1 mm, range: 13.5-37.1 mm), L6 (median: 29.0 mm, range: 0.0-36.3 mm), L7 (median: 20.8 mm, range: 0.0-39.2 mm). The median distance of the optic foramen from IM is 43.7 mm (range: 37.0- 49.1) at L7. Conclusion Distance to PL from IM increases medially until the L5 before decreasing. A reference map of the PL in relation to the IM and optic foramen is generated. The optic foramen is located in close proximity to the PL at the medial orbital floor. This aids in preoperative planning and intraoperative dissection.

9.
Mali Med ; 37(1): 32-35, 2022.
Artigo em Francês | MEDLINE | ID: mdl-38196251

RESUMO

Atrial fibrillation is the most frequent permanent rhythm disorder.Theaim of this work was to determine the epidemiological and clinical aspects of atrial fibrillation cases hospitalized in the cardiology department of the University Hospital of Kati. MATERIALS AND METHODS: We carried out a descriptive retrospective study, from January 2018 to December 2019.Patients of all ages and both sexes with clinical and EKG atrial fibrillation admitted to the department during the study period were included in the study.The variables studiedwere: socio-demographic characteristics, clinical signs, classification of atrial fibrillation, and comorbidities associated. RESULTS: A total of 52 patients were included in the studyof 203 cases hospitalized in the department, with a hospital prevalence of 25.61%, the female sex was predominant 69.23%. The main reason for consultation was heart failure syndrome (46.15%).Arterial hypertension (55.76%) was the mostassociatedcomorbidity. Permanent atrial fibrillation accounted for 63.46% of cases . CONCLUSION: Atrial fibrillation is the most frequent arrhythmia in our environment, preventive measures must be put in place for early detection and better management of comorbiditiesassociatedwith atrial fibrillation.


La fibrillation auriculaire est le trouble du rythme le plus fréquent. Le but de ce travail était de déterminer les aspects épidémiologiques et cliniques de la fibrillation atriale dans le service de cardiologie du CHU de Kati. MATÉRIELS ET MÉTHODES: Il s'agit d'une étude rétrospective descriptive menée de janvier 2018 à décembre 2019. Ont été inclus dans cette étude les patients de tout âge et des deux sexes ayant présenté une fibrillation atriale sur des critères cliniques et électrocardiographiques, admis dans le service pendant la période d'étude. Les variables étudiées étaient : les caractéristiques sociodémographiques, les signes cliniques et électriques, et les comorbidités associées. RÉSULTATS: Au total 52 patients ont été inclus dans l'étude sur 203 cas hospitalisés dans le service soit une prévalence hospitalière de 25,61%, le sexe féminin a été prédominant 69,23%. Le principal motif de consultation était le syndrome d'insuffisance cardiaque (46,15%). L'hypertension artérielle (55,76%) a été la comorbidité la plus associée. La fibrillation atriale permanente représentait 63,46% des cas. CONCLUSION: La fibrillation atriale est l'arythmie la plus fréquente dans notre milieu, des mesures préventives doivent être mise en place pour une détection précoce et une meilleure prise en charge des comorbidités associées.

10.
Mali Med ; 36(2): 19-22, 2021.
Artigo em Francês | MEDLINE | ID: mdl-37973584

RESUMO

INTRODUCTION: High blood pressure is a major cardiovascular risk factor. Patients with cardiovascular risk factors are at risk of developing COVID-19. The objective of this study was to determine epidemiology of Covid-19 infected in patients with high blood pressure. PATIENTS AND METHOD: Descriptive cross-sectional study from April 2020 to June 2020 about patients hospitalized for Covid 19 by PCR diagnosis at the Hopital du Mali Bamako and having high blood pressure. Admission registry and patient charts were used to collect data. RESULTS: We collected 78 out of 484 in patients which mean hospital frequency of 16.11%. The mean age was 55.21 +/- 14.61 years. Sex ratio M / F was 1.36. Patients were followed for high blood pressure in 59% of cases. Medical history was ischemic heart disease in 2.6% and dilated cardiomyopathy in 2.6%. Main functional signs were cough in 41.02% and lost of taste in 11.53%. High blood pressure on admission was grade 2 in 37.2% and grade 3 in 3.8%. Treatments received were calcium channel blockers 41.02%, inhibitors of the reninangiotensinaldosterone system 16.66% and combinations 15.38%. Hospital mortality was 10.3%. There was no statistically significant difference in mortality between known hypertensive patients and de novo hypertensive patients. There was also no statistically significant difference in mortality by grade of hypertension. CONCLUSION: High blood pressure can be associated to Covid 19. Treatment is based on calcium channel blockers and reninangiotensinaldosterone system inhibitors. It has an impact on the prognosis of the disease with significant mortality.


INTRODUCTION: L'hypertension artérielle (HTA) est un facteur de risque cardiovasculaire majeur. Dans la littérature elle est fréquemment retrouvée chez les patients atteints de la COVID-19.L'objectif de cette étude est de décrire l'épidémiologie de cette association chez les patients hospitalisés pour Covid-19. PATIENTS ET MÉTHODE: L'Etude est transversale et descriptive ; elle a été réalisée sur la période du 1erAvril 2020 au 30 Juin 2020. Elle a concerné les patients hospitalisés pour Covid 19 avec un test PCR positif à l'hôpital du Mali de Bamako et ayant une HTA. Les registres d'admission et les dossiers des patients ont servi pour la collecte des données. RÉSULTATS: Nous avons colligé 78 sur 484 patients hospitalisés soit une fréquence de 16,11%. L'âge moyen était de 55,21 +/- 14,61 ans. Le sex ratio H/F était de 1,36.Les patients étaient suivis pour HTA dans 59% des cas. Les antécédents médicaux étaient la cardiopathie ischémique chez 2,6% et la cardiomyopathie dilatée chez 2,6%. Les principaux signes fonctionnels étaient la toux chez 41,02% et l'agueusie chez 11,53%. L'HTA à l'admission était de grade 2 dans 37,2% des cas et de grade 3 dans 3,8% des cas. Les traitements reçus étaient les inhibiteurs calciques 41,02%, les inhibiteurs du système rénine angiotensine aldostérone 16,66% et les associations 15,38%. La mortalité hospitalière était de 10,3%. Il n'y avait pas de différence statistiquement significative concernant la mortalité entre les patients connus hypertendus et les patients hypertendus de novo. Il n'y avait pas non plus de différence statistiquement significative concernant la mortalité selon le grade de l'HTA. CONCLUSION: l'HTA peut être associée au Covid 19. Le traitement est basé sur les inhibiteurs calciques et sur les inhibiteurs du système rénine angiotensine aldostérone. Elle a un impact sur le pronostic de la maladie avec une mortalité importante.

11.
Appl Radiat Isot ; 156: 108964, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31706855

RESUMO

This article describes the Nuclide++ module developed at LNE-LNHB to simulate the decay schemes related to single or multiple radionuclides, by randomly selecting decay pathways. Written in C++, with respect of the Geant4 coding style, this module can be used transparently in Geant4-based simulation applications as an alternative to the existing Radioactive Decay Module (RDM). Nuclide++ takes advantage of the DDEP recommended data, accurate ß-emitting spectra calculation and detailed description of the atomic rearrangement. This module can be useful in many applications, especially those involving radioactive sources. The reliability of the module was verified through comparisons with a while chosen radionuclides.

12.
Appl Radiat Isot ; 166: 109349, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32818806

RESUMO

The 2011 Decay Data Evaluation Project (DDEP) evaluation for 147Nd includes recommended absolute emission intensities for the two main gamma-rays at 91.105 (2) keV and 531.016 (22) keV of 0.284 (18) and 0.127 (9) respectively, i.e. with uncertainties of 6.3% and 7.1%. These large uncertainties stem from inconsistencies in the published data and are unfit for modern purposes, since the production of 147Nd is used as an important neutron flux dosimeter. The LNE-LNHB has undertaken new absolute gamma-ray emission intensity measurements. The results of these measurements will be presented, along with a full uncertainty budget, and their effect on the recommended data uncertainties will be discussed.

13.
Appl Radiat Isot ; 158: 109068, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32174369

RESUMO

Spectral unmixing was investigated for fast spectroscopic identification in γ-emitter mixtures at low-statistics in the case of measurements performed to prevent illegal nuclear material trafficking or for in situ environmental analysis following a radiological or nuclear accident. For that purpose, a multiplicative update algorithm based on full-spectrum analysis was tested in the case of a 3″x3″ NaI(Tl) detector. Automatic decision-making was addressed using Monte Carlo calculations of decision thresholds and detection limits. The first results obtained with a portable instrument equipped with a 3″x3″ NaI(Tl) detector designed for the control of food samples by non-expert users following a radiological or nuclear accident, are also presented.

14.
Appl Radiat Isot ; 153: 108826, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31525708

RESUMO

Holmium-166 is a high-energy ß--emitter radionuclide (~ 1.8 MeV) with a short half-life (~26.8h) that offers great potential as an alternative to 90Y for the treatment of liver cancer based on radioembolization. The possibility of quantitative Single Photon Emission Computed Tomography (SPECT) imaging of the main γ-ray emission at 80.6 keV, in addition to strong paramagnetic properties suitable for Magnetic Resonance Imaging (MRI), complement this therapeutic potential. The present paper describes the measurements carried out in three European radionuclide metrology laboratories for primary standardization of 166Ho and new determinations of X- and γ-ray photon-emission intensities in the framework of the European EMPIR project MRTDosimetry. New half-life measurements were also performed.


Assuntos
Hólmio/análise , Doses de Radiação , Radioisótopos/análise , Humanos , Neoplasias Hepáticas/diagnóstico por imagem , Neoplasias Hepáticas/radioterapia , Tomografia Computadorizada de Emissão de Fóton Único
15.
Appl Radiat Isot ; 154: 108850, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31476556

RESUMO

Monte Carlo (MC) simulation is widely used in gamma-ray spectrometry, however, its implementation is not always easy and can provide erroneous results. The present action provides a benchmark for several MC software for selected cases. The examples are based on simple geometries, two types of germanium detectors and four kinds of sources, to mimic eight typical measurement conditions. The action outputs (input files and efficiency calculation results, including practical recommendations for new users) are made available on a dedicated webpage.

16.
Phys Med Biol ; 53(11): 3039-55, 2008 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-18490808

RESUMO

The GATE Monte Carlo simulation platform based on the Geant4 toolkit has now become a diffused tool for simulating PET and SPECT imaging devices. In this paper, we explore its relevance for dosimetry of low-energy 125I photon brachytherapy sources used to treat prostate cancers. To that end, three 125-iodine sources widely used in prostate cancer brachytherapy treatment have been modelled. GATE simulations reproducing dosimetric reference observables such as radial dose function g(r), anisotropy function F(r, theta) and dose-rate constant (Lambda) were performed in liquid water. The calculations were splitted on the EGEE grid infrastructure to reduce the computing time of the simulations. The results were compared to other relevant Monte Carlo results and to measurements published and fixed as recommended values by the AAPM Task Group 43. GATE results agree with consensus values published by AAPM Task Group 43 with an accuracy better than 2%, demonstrating that GATE is a relevant tool for the study of the dose induced by low-energy photons.


Assuntos
Simulação por Computador , Fótons/uso terapêutico , Neoplasias da Próstata/diagnóstico por imagem , Anisotropia , Braquiterapia/métodos , Humanos , Radioisótopos do Iodo , Masculino , Método de Monte Carlo , Cintilografia
17.
Stud Health Technol Inform ; 138: 34-48, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18560106

RESUMO

The paper describes a platform developed for the secure management and analysis of medical data and images in a grid environment. Designed for telemedicine and built upon the EGEE gLite middleware and particularly the metadata catalogue AMGA as well as the GridSphere web portal, the platform provides to healthcare professionals the capacity to upload and query medical information stored over distributed servers. A job submission environment is also available for data analysis. Security features include authentication and authorization by grid certificates, anonymization of medical data and image encryption. The platform is currently deployed on several sites in Europe and Asia and is being customized for applications in the field of telemedicine and medical physics.


Assuntos
Segurança Computacional/instrumentação , Sistemas Computacionais , Computação em Informática Médica , Sistemas Computadorizados de Registros Médicos/organização & administração , Telemedicina/organização & administração , Acesso à Informação , Algoritmos , Bases de Dados como Assunto , França , Humanos , Método de Monte Carlo , Neurocirurgia/organização & administração , Software
18.
Appl Radiat Isot ; 134: 252-256, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28676277

RESUMO

In the framework of an international BIPM comparison (Bureau International des Poids et Mesures), the activity standardization of 68Ge in a solution of 68Ge/68Ga in equilibrium provided by NIST was carried out at LNHB. This exercise was organized to meet the growing interest in 68Ga as a radiopharmaceutical in nuclear medicine services (e.g. as a surrogate of 18F for PET imaging). Due to the volatility of germanium, the activity standardization of 68Ge was investigated at LNHB by means of 4πß-γ coincidence counting based on Cherenkov measurements. This technique was applied to take advantage of the Cherenkov threshold (~ 260keV in aqueous solutions) in order to prevent counting from electron-capture events associated with 68Ge disintegrations. Cherenkov counting was performed using glass and polyethylene vials and the resulting activity concentrations were compared with 4πß-γ coincidence measurements based on liquid scintillation. The efficiency-extrapolation curve obtained with Cherenkov measurements in glass vials was compared to Monte Carlo simulations based on the Geant4 code.

19.
Appl Radiat Isot ; 119: 60-65, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27846441

RESUMO

Due to their stability and reproducibility, re-entrant pressurized ionization chambers (also called radionuclide calibrators) are widely used for activity measurements in nuclear medicine services as well as in national metrology institutes to maintain reference standards. Generally, these secondary instruments yield accurate activity measurements for γ-emitting radionuclides. Ionization chambers are easy to use and thus well-adapted to guarantee the metrological traceability between national metrology institutes and end-users. However, the reproducibility of calibration factors can be significantly impaired when measuring high-energy pure ߯-emitters such as radiopharmaceuticals based on 90Y. This is because the bremsstrahlung emission contributing to the instrument response is strongly dependent on the geometry of the components surrounding the radioactive solution. The present article describes a new design based on pulse counting to address this problem. It takes advantage of Cherenkov emission resulting from Compton scattering in transparent materials. The interest of Cherenkov counting is to obtain a low-sensitivity detector that enables direct measurements of high-activity solutions (at least up to 10 GBq for 90Y-microspheres in aqueous suspensions used in nuclear medicine). A simple design based on a geometry close to an ionization chamber used at LNHB (Vinten 671 type) is described. The feasibility in terms of detection efficiencies (lower than 10-4 for 90Y solutions) of the new radionuclide calibrator is investigated by Monte Carlo calculations using the Geant4 code.

20.
Int Angiol ; 36(1): 1-20, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27606807

RESUMO

The Asian venous thromboembolism (VTE) prophylaxis guidelines were first published in 2012. Since its first edition, the Asian Venous Thrombosis Forum (AVTF) working group have updated the Asian VTE epidemiology and reviewed issues that were not addressed in the previous guidelines. The authors noted that the rising incidence of VTE across Asia may be attributable to aging population, dietary changes, and increasing incidence of obesity and diabetes. The new additions in the guideline include role of thrombophilia in VTE, bleeding risk in Asians, individual risk assessment, updates in the prevention of VTE in medically ill, bariatric surgery, cancer, orthopedic and trauma patients. The influence of primary thrombophilia in perioperative VTE is still unclear. The secondary risk factors, however, are similar between Asians and Caucasians. The group found no evidence of increased risk of bleeding while using pharmacological agents, including the use of novel anti-coagulants. At present, Caprini risk assessment model is widely used for individual risk assessment. Further validation of this model is needed in Asia. In medically ill patients, pharmacological agents are preferred if there is no bleeding risk. Intermittent pneumatic compression device (IPC) is recommended in patients with bleeding risk but we do not recommend using graduated compressive stockings. In bariatric patients, data on VTE is lacking in Asia. We recommend following current international guidelines. A high index of suspicion should be maintained during postbariatric surgery to detect and promptly treat portomesenteric venous thrombosis. Different cancer types have different thrombotic risks and the types of surgery influence to a large extent the overall VTE risk. Cancer patients should receive further risk assessment. In patients with higher thrombotic risk, either due to predisposing risk or concomitant surgery, low molecular weight heparin is indicated. Different countries appear to have different incidence of VTE following trauma and major orthopedic surgery. We recommend mechanical prophylaxis using IPC as the main method and additional pharmacological prophylaxis if the thrombotic risk is high. As for obstetric practice, we propose adherence to the UK Greentop guideline that is widely accepted and utilized across Asia. To improve VTE thromboprophylaxis implementation in the region, we propose that there should be better health education, establishment of hospital-based guidelines and multidisciplinary collaboration.


Assuntos
Tromboembolia Venosa/prevenção & controle , Tromboembolia Venosa/terapia , Anticoagulantes/uso terapêutico , Ásia/epidemiologia , Feminino , Fibrinolíticos/uso terapêutico , Hemorragia/prevenção & controle , Humanos , Incidência , Dispositivos de Compressão Pneumática Intermitente , Masculino , Complicações Pós-Operatórias/prevenção & controle , Gravidez , Medição de Risco , Fatores de Risco , Sociedades Médicas , Meias de Compressão
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