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1.
Artigo em Inglês | LILACS, BBO - Odontologia | ID: biblio-1448795

RESUMO

ABSTRACT Objective: To evaluate an imaging protocol for use as a diagnostic and calibration tool for dentists before and after practical activity. Material and Methods: Thirty photos of children's teeth with or without changes in dental enamel were selected and evaluated by a group of experienced dentists previously calibrated to establish the diagnosis defined as the gold standard. After instructions, the images were shown to a group of postgraduate dentists for free identification of dental changes. Subsequently, a lecture on molar incisor hypomineralization (MIH) was carried out, and, at 14 days and all calibration was performed using the criteria previously. The retest was performed at 28 days. After experience in clinical activity in the following two weeks, the post-test was performed at 49 days. Data were analyzed using Cohen's kappa coefficient. Results: Theoretical learning on the subject showed low inter-examiner agreement when the diagnosis of defects was made from images obtained from intraoral photographs. After clinical practice, there was greater intra-examiner agreement. After theoretical training, dentists started to identify different types of enamel alteration, although with low agreement between them. Conclusion: Clinical experience in theoretical and imaging training favored the identification of defects. However, it is necessary to improve the protocol to establish a reliable and viable diagnostic method for calibration in MIH.


Assuntos
Humanos , Masculino , Feminino , Hipoplasia do Esmalte Dentário/diagnóstico por imagem , Hipomineralização Molar/diagnóstico por imagem , Calibragem/normas , Fotografia Dentária/instrumentação
2.
Aval. psicol ; 21(2): 127-139, abr.-jun. 2022. il, tab
Artigo em Português | LILACS, Index Psicologia - Periódicos | ID: biblio-1447458

RESUMO

A Bateria de Provas de Raciocínio (BPR-5) é um instrumento bastante utilizado para avaliação da inteligência no Brasil, possuindo três formas: infantil (1º ao 6º ano do Ensino Fundamental), Forma A (7º ao 9º ano do Ensino Fundamental) e Forma B (Ensino Médio e Superior). Visando a possibilidade de comparar os resultados entre sujeitos que respondem a formas diferentes, o presente estudo objetivou: (a) calibrar os itens das três formas pelo modelo de Rasch, realizando a equalização por itens comuns de modo a obter uma escala equiparável para as três formas, (b) atualizar as normas expandindo a representatividade das amostras e produzindo-se normas para diferentes combinações de idade, escolaridade e sexo, (c) descrever padrões de desenvolvimento da inteligência a partir da escala, comum, produzida entre 6 e 52 anos. Dois estudos foram relatados, o primeiro sobre a calibração dos parâmetros segundo o modelo de Rasch indicando um bom ajuste ao modelo. O segundo estudo exemplificou a utilização de regressão múltipla para criação de normas para testes psicológicos, considerando as variáveis idade, escolaridade e sexo como preditoras dos escores na BPR-5. Essas três variáveis tiveram efeitos significativos explicando 8% (Raciocínio Abstrato), 13% (Raciocínio Verbal), 12% (Raciocínio Espacial), 8% (Raciocínio Numérico) e 22% (Raciocínio Mecânico).(AU)


The Reasoning Tests Battery (BPR-5) is widely used in Brazil for the assessment of intelligence. It has three different forms: children (1st to 6th grade of elementary school), Form A (7th to 9th grade of elementary school) and Form B (high school and higher education). This study describes the steps followed to create a common metric across the forms. It aimed to: (a) calibrate the items of the three forms using Rasch model, link items and equate subjects' scores across forms using the anchoring of common items method, (b) update the norms by expanding the representativeness of the samples by producing norms for different combinations of age, education and sex, and (c) describe the developmental patterns of the BPR-5 subtests across a wide age range, from 6 to 52 years. We present two studies, the first reporting the calibration of item and person parameters with the Rasch model and a good fit to the model. The second illustrated the use of multiple regression analysis to create norms for the psychological tests considering the variables age, education and gender as predictors of the BPR-5 scores. These three variables had significant effects explaining 8% (Abstract Reasoning), 13% (Verbal Reasoning), 12% (Spatial Reasoning), 8% (Numerical Reasoning) and 22% (Mechanical Reasoning) of the variance. (AU)


La Batería de Pruebas de Razonamiento (BPR-5) es un instrumento muy utilizado para la evaluación de la inteligencia en Brasil, disponiendo de tres formas: infantil (1° al 6° año de la Enseñanza Fundamental), Forma A (7° al 9° año de la Enseñanza Fundamental) y Forma B (Bachillerato y Educación Superior). Teniendo como finalidad la posibilidad de comparar los resultados entre sujetos que responden a diferentes versiones, el presente estudio tuvo como objetivo: (a) calibrar los ítems de las tres formas por el modelo de Rasch, realizando la igualación por ítems comunes a fin de obtener una escala equiparable para las tres formas, (b) actualizar las normas ampliando la representatividad de las muestras y produciendo normas para diferentes combinaciones de edad, escolarización y sexo, (c) describir patrones de desarrollo de la inteligencia a partir de la escala, común, producida entre los 6 y los 52 años. Dos estudios fueron reportados, el primer sobre la calibración de los parámetros de acuerdo con el modelo de Rasch, indicando un buen ajuste al modelo. El segundo estudio ejemplificó la utilización de regresión múltiple para crear normas para tests psicológicos, considerando las variables edad, educación y sexo como predictivos de los escores en el BPR-5. Esas tres variables tuvieron efectos significativos explicando 8% (Razonamiento Abstracto), 13% (Razonamiento Verbal), 12% (Razonamiento Espacial), 8% (Razonamiento Numérico), y 22% (Razonamiento Mecánico).(AU)


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Inteligência , Testes de Inteligência/normas , Psicometria , Calibragem/normas , Análise de Regressão , Escolaridade , Distribuição por Idade e Sexo
3.
Fertil Steril ; 117(1): 15-21, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34753600

RESUMO

When a diverse group of individuals is working together in the contemporary fertility clinic to provide time-sensitive and complex care for patients, a high degree of coordination and collaboration must take place. When performed dynamically, this process is referred to as teaming. Although the positive impact of teamwork in health care settings has been well established in the literature, the concept of teaming has limited foundation in the clinic. This review will provide an overview of how teaming can be used to improve patient care in today's fertility clinics. Approaches to integrating teaming into the clinic that will be discussed include framing, the creation of a psychologically safe environment for staff input, and facilitating collaborative constructs to support teaming. Best practices to implement teaming and how to address challenges to teaming in today's clinical environment will also be addressed.


Assuntos
Clínicas de Fertilização , Cultura Organizacional , Equipe de Assistência ao Paciente/organização & administração , Instituições de Assistência Ambulatorial/organização & administração , Instituições de Assistência Ambulatorial/tendências , Calibragem/normas , Atenção à Saúde/organização & administração , Atenção à Saúde/normas , Atenção à Saúde/tendências , Feminino , Clínicas de Fertilização/organização & administração , Clínicas de Fertilização/tendências , Humanos , Masculino , Assistência ao Paciente/normas , Assistência ao Paciente/tendências , Equipe de Assistência ao Paciente/normas , Equipe de Assistência ao Paciente/tendências , Medicina de Precisão/métodos , Medicina de Precisão/tendências , Gravidez
4.
Ann Thorac Surg ; 113(2): 386-391, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34717906

RESUMO

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database is the world's premier adult cardiac surgery outcomes registry. This tutorial explains the following: how STS updates the risk models that are used to calculate the predicted risks of adverse events in the registry; why STS on a quarterly basis adjusts or "calibrates" the observed-to-expected ratios to equal 1 (O/E = 1), thereby effectively making the annual number of adverse events predicted by the model match the annual number of adverse events observed in the entire registry; the differences between the calibrated and uncalibrated O/E ratios; and how and when to use each.


Assuntos
Ponte de Artéria Coronária/normas , Doença da Artéria Coronariana/cirurgia , Sistema de Registros , Medição de Risco/métodos , Sociedades Médicas , Cirurgia Torácica , Adulto , Calibragem/normas , Doença da Artéria Coronariana/epidemiologia , Bases de Dados Factuais , Seguimentos , Humanos , Incidência , Estudos Retrospectivos , Fatores de Risco , Taxa de Sobrevida/tendências , Estados Unidos/epidemiologia
5.
Rio de Janeiro; rBLH; 2 rev; set. 2021. [8] p. ilus.(Normas técnicas BLH-IFF/NT, 1, 44). (BLH-IFF/NT 44.21).
Monografia em Espanhol, Português | LILACS, BVSAM | ID: biblio-1436547

RESUMO

Esta Norma Técnica tem por objetivo estabelecer as orientações necessárias para aferição e leitura dos termômetros utilizados no controle de temperatura nos Bancos de Leite Humano e Postos de Coleta de Leite Humano, visando a garantia da qualidade nestes serviços e sua certificação.


Esta Norma Técnica tiene como objetivo establecer las orientaciones necesarias para la medición y la lectura de los termómetros utilizados en el control de la temperatura en los Bancos de Leche Humana y en los Centros de Recolección de Leche Humana, con el fin de garantizar la calidad de estos servicios y su certificación.


Assuntos
Controle de Qualidade , Temperatura , Termômetros/normas , Calibragem/normas , Bancos de Leite Humano/normas , Leite Humano
6.
Opt Express ; 29(14): 22127-22135, 2021 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-34265984

RESUMO

Quantitative phase imaging (QPI) exploits sample-induced changes in the optical field to analyze biological specimens in a label-free manner. However, the quantitative nature of QPI makes it susceptible to optical aberrations. We propose a method for calibrating pupil aberrations by imaging a sample of interest. The proposed method recovers pupil information by utilizing the cross-spectral density between optical fields at different incident angles and allows both thin and weakly scattering three-dimensional samples for calibration. We experimentally validate the proposed method by imaging various samples, including a resolution target, breast tissue, and a polystyrene bead, and demonstrate aberration-free two- and three-dimensional QPI.


Assuntos
Algoritmos , Calibragem/normas , Processamento de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Microscopia/métodos , Pupila , Humanos , Iluminação
7.
Bioanalysis ; 13(10): 787-796, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33960820

RESUMO

Biomarker assay method development is a multistep rigorous process and calibrant material selection is integral to ensuring the quality of such assays. However, the impact of selection of calibrator material may often get overlooked. In this article, we highlight three case studies where biomarker calibrant material selection was deemed an essential criterion for consideration. Through these case studies we highlight challenges faced, steps taken and discuss the impact on assay-related decision-making. We also provide additional perspectives for selection and characterization of calibrant proteins in the setting of an evolving biomarker context of use.


Assuntos
Bioensaio/métodos , Calibragem/normas , Biomarcadores/metabolismo , Humanos
8.
Appl Opt ; 60(5): 1380-1386, 2021 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-33690582

RESUMO

Mueller matrix (MM) imaging has demonstrated its potential application in much research, especially in probing delicate and complex biomedical specimens. Qualities of MM images are important for further quantitative characterization. In this paper, we compare the performance and imaging qualities of three calibration methods. Air, waveplate and cell specimen are selected as standard samples for comparison. In addition, we also propose two general MM imaging quality indices that can be used as quantitative evaluations for MM imaging systems and calculation processes based on real samples. The numerical calibration method turns out to give the best accuracy and precision, as well as the best image qualities.


Assuntos
Microscopia de Polarização/métodos , Imagem Óptica/métodos , Ar , Calibragem/normas , Células HeLa , Humanos , Luz , Microscopia de Polarização/normas , Imagem Óptica/normas
9.
J Healthc Eng ; 2021: 6680762, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33628406

RESUMO

Out of all the changes to our daily life brought by the COVID-19 pandemic, one of the most significant ones has been the limited access to health services that we used to take for granted. Thus, in order to prevent temporary injuries from having lingering or permanent effects, the need for home rehabilitation device is urgent. For this reason, this paper proposes a cable-driven device for limb rehabilitation, CUBE2, with a novel end-effector (EE) design and autotuning capabilities to enable autonomous use. The proposed design is presented as an evolution of the previous CUBE design. In this paper, the proposed device is modelled and analyzed with finite element analysis. Then, a novel vision-based control strategy is described. Furthermore, a prototype has been manufactured and validated experimentally. Preliminary test to estimate home position repeatability has been carried out.


Assuntos
Serviços de Assistência Domiciliar , Telerreabilitação , Algoritmos , Fenômenos Biomecânicos , COVID-19 , Calibragem/normas , Desenho de Equipamento , Humanos , Robótica/instrumentação , SARS-CoV-2 , Telerreabilitação/instrumentação , Telerreabilitação/métodos , Telerreabilitação/normas
10.
Sci Rep ; 11(1): 389, 2021 01 11.
Artigo em Inglês | MEDLINE | ID: mdl-33431989

RESUMO

Lentiviral vectors (LV) have emerged as a robust technology for therapeutic gene delivery into human cells as advanced medicinal products. As these products are increasingly commercialized, there are concomitant demands for their characterization to ensure safety, efficacy and consistency. Standards are essential for accurately measuring parameters for such product characterization. A critical parameter is the vector copy number (VCN) which measures the genetic dose of a transgene present in gene-modified cells. Here we describe a set of clonal Jurkat cell lines with defined copy numbers of a reference lentiviral vector integrated into their genomes. Genomic DNA was characterized for copy number, genomic integrity and integration coordinates and showed uniform performance across independent quantitative PCR assays. Stability studies during continuous long-term culture demonstrated sustained renewability of the reference standard source material. DNA from the Jurkat VCN standards would be useful for control of quantitative PCR assays for VCN determination in LV gene-modified cellular products and clinical samples.


Assuntos
Dosagem de Genes , Lentivirus/genética , Transdução Genética , Calibragem/normas , Técnicas de Transferência de Genes/normas , Vetores Genéticos/genética , Humanos , Células Jurkat , Mutagênese Insercional/genética , Padrões de Referência , Reprodutibilidade dos Testes , Transdução Genética/métodos , Transdução Genética/normas , Transfecção/métodos , Transfecção/normas , Estudos de Validação como Assunto , Integração Viral/genética
11.
J Chromatogr A ; 1635: 461631, 2021 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-33260023

RESUMO

Asymmetrical flow field-flow fractionation is a versatile chromatographic fractionation method. In combination with at least one detection technique it is used for size-based separation of colloids, biomolecules and polymers. Although often used as pure separation method, a well-elaborated theory is available that allows precise quantification of the translational diffusion coefficient D. Still, current literature suggests different ways to transform this theory into applicable experimental procedures and no "gold standard" for correct data processing exists. While some sources report a direct way to extract diffusion information from the fractogram, others suggest the necessity of an external calibration measurement to obtain the channel width w. In this work, we compare the different approaches and calibration algorithms based on original and literature data using our own open-source AF4 evaluation software. Based on the results, we conclude that available AF4 setups do not fulfill the requirements for absolute measurements of D. We show that the best way to conduct is to consider the area of the channel and D of the calibrant while neglecting the small peak which occurs in the void peak region.


Assuntos
Calibragem/normas , Técnicas de Química Analítica/métodos , Fracionamento por Campo e Fluxo , Algoritmos , Técnicas de Química Analítica/normas , Difusão , Tamanho da Partícula , Polímeros/química
12.
Curr Opin Neurol ; 34(1): 142-149, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33278146

RESUMO

PURPOSE OF REVIEW: Experimental preclinical models of recovery of consciousness (ROC) and anesthesia emergence are crucial for understanding the neuronal circuits restoring arousal during coma emergence. Such models can also potentially help to better understand how events during coma emergence facilitate or hinder recovery from brain injury. Here we provide an overview of current methods used to assess ROC/level of arousal in animal models. This exposes the need for objective approaches to calibrate arousal levels. We outline how correlation of measured behaviors and their reestablishment at multiple stages with cellular, local and broader neuronal networks, gives a fuller understanding of ROC. RECENT FINDINGS: Animals emerging from diverse coma-like states share a dynamic process of cortical and behavioral recovery that reveals distinct states consistently sequenced from low-to-high arousal level and trackable in nonhuman primates and rodents. Neuronal activity modulation of layer V-pyramidal neurons and neuronal aggregates within the brainstem and thalamic nuclei play critical roles at specific stages to promote restoration of a conscious state. SUMMARY: A comprehensive, graded calibration of cortical, physiological, and behavioral changes in animal models is undoubtedly needed to establish an integrative framework. This approach reveals the contribution of local and systemic neuronal circuits to the underlying mechanisms for recovering consciousness.


Assuntos
Nível de Alerta/fisiologia , Transtornos da Consciência/patologia , Transtornos da Consciência/reabilitação , Modelos Animais de Doenças , Animais , Tronco Encefálico/patologia , Tronco Encefálico/fisiopatologia , Calibragem/normas , Estado de Consciência/fisiologia , Humanos , Primatas , Recuperação de Função Fisiológica/fisiologia , Roedores
13.
Reprod Biol Endocrinol ; 18(1): 86, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32799874

RESUMO

BACKGROUND: There is a need for a reference material to support the development and ensure the quality of immunoassays for human AMH. A batch of ampoules, coded 16/190, containing lyophilised recombinant AMH was evaluated in a WHO Collaborative Study. The aims of the study were to determine the AMH content in terms of the calibration of each immunoassay method, to predict long-term stability and to assess the suitability of the preparation to calibrate AMH immunoassays. METHODS: Study participants were asked to report the AMH content of specific dilutions of coded ampoules of 16/190 and a comparator preparation containing approximately half the AMH content. In each assay, participants also reported the AMH content of 22 patient samples to assess commutability. A robust all-laboratory geometric mean of the content estimates was determined using the laboratory geometric mean estimates. Commutability was assessed using a difference in bias approach. Stability was predicted by the measurement of thermally accelerated degradation samples. RESULTS: Seven laboratories performed twenty-one immunoassay method-platform combinations, sixteen of which provided data which met the validity criteria, giving a consensus geometric mean estimate of AMH content of 511 ng/ampoule (95% CI, 426-612, n = 16, GCV 42%) and a robust geometric mean of 489 ng/ampoule. By contrast, the GCV% for the all-laboratory geometric mean of the relative content estimates for the comparator sample to 16/190 was 12%. Commutability was assessed using 20 of the 22 representative patient samples. Of the valid assays, 16/190 was within the limits of acceptable commutability for 6 methods, partially commutable for a further 3 methods and non-commutable when measured by 7 methods. The preparation was predicted to be highly stable when stored at - 20 °C. CONCLUSION: The majority of methods met the validity criteria. Content estimates showed a high between-method variability, yet assays exhibited a similar proportionality of response as demonstrated using the comparator sample. 16/190 was commutable in some but not all methods. On the basis of these results, it was agreed by the WHO Expert Committee on Biological Standardization to establish 16/190 as a WHO Reference Reagent for AMH with a content defined by consensus immunoassay of 489 ng/ampoule.


Assuntos
Hormônio Antimülleriano/análise , Bioensaio/normas , Indicadores e Reagentes , Organização Mundial da Saúde , Animais , Hormônio Antimülleriano/sangue , Bioensaio/métodos , Células CHO , Calibragem/normas , Serviços de Laboratório Clínico/normas , Cricetulus , Feminino , Humanos , Imunoensaio/métodos , Imunoensaio/normas , Indicadores e Reagentes/análise , Indicadores e Reagentes/isolamento & purificação , Cooperação Internacional , Internacionalidade , Ensaio de Proficiência Laboratorial/normas , Padrões de Referência
14.
Proc Natl Acad Sci U S A ; 117(35): 21005-21007, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32817536

RESUMO

The new radiocarbon calibration curve (IntCal20) allows us to calculate the gradient of the relationship between 14C age and calendar age over the past 55 millennia before the present (55 ka BP). The new gradient curve exhibits a prolonged and prominent maximum between 48 and 40 ka BP during which the radiocarbon clock runs almost twice as fast as it should. This radiocarbon time dilation is due to the increase in the atmospheric 14C/12C ratio caused by the 14C production rise linked to the transition into the Laschamp geomagnetic excursion centered around 41 ka BP. The major maximum in the gradient from 48 to 40 ka BP is a new feature of the IntCal20 calibration curve, with far-reaching impacts for scientific communities, such as prehistory and paleoclimatology, relying on accurate ages in this time range. To illustrate, we consider the duration of the overlap between Neanderthals and Homo sapiens in Eurasia.


Assuntos
Paleontologia/métodos , Datação Radiométrica/métodos , Animais , Calibragem/normas , Fósseis , Humanos , Homem de Neandertal
15.
Phys Med Biol ; 65(19): 195006, 2020 09 22.
Artigo em Inglês | MEDLINE | ID: mdl-32503026

RESUMO

The 1990 code of practice (COP), produced by the IPSM (now the Institute of Physics and Engineering in Medicine, IPEM) and the UK National Physical Laboratory (NPL), gave instructions for determining absorbed dose to water for megavoltage photon (MV) radiotherapy beams (Lillicrap et al 1990). The simplicity and clarity of the 1990 COP led to widespread uptake and high levels of consistency in external dosimetry audits. An addendum was published in 2014 to include the non-conventional conditions in Tomotherapy units. However, the 1990 COP lacked detailed recommendations for calibration conditions, and the corresponding nomenclature, to account for modern treatment units with different reference fields, including small fields as described in IAEA TRS483 (International Atomic Energy Agency (IAEA) 2017, Vienna). This updated COP recommends the irradiation geometries, the choice of ionisation chambers, appropriate correction factors and the derivation of absorbed dose to water calibration coefficients, for carrying out reference dosimetry measurements on MV external beam radiotherapy machines. It also includes worked examples of application to different conditions. The strengths of the 1990 COP are retained: recommending the NPL2611 chamber type as secondary standard; the use of tissue phantom ratio (TPR) as the beam quality specifier; and NPL-provided direct calibration coefficients for the user's chamber in a range of beam qualities similar to those in clinical use. In addition, the formalism is now extended to units that cannot achieve the standard reference field size of 10 cm × 10 cm, and recommendations are given for measuring dose in non-reference conditions. This COP is designed around the service that NPL provides and thus it does not require the range of different options presented in TRS483, such as generic correction factors for beam quality. This approach results in a significantly simpler, more concise and easier to follow protocol.


Assuntos
Calibragem/normas , Imagens de Fantasmas , Fótons/uso terapêutico , Radiometria/métodos , Radiometria/normas , Radioterapia de Alta Energia/normas , Humanos , Agências Internacionais , Dosagem Radioterapêutica , Água
16.
J Appl Clin Med Phys ; 21(2): 50-59, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32039545

RESUMO

In breast-targeted intraoperative radiotherapy (TARGIT) clinical trials (TARGIT-B, TARGIT-E, TARGIT-US), a single fraction of radiation is delivered to the tumor bed during surgery with 1.5- to 5.0-cm diameter spherical applicators and an INTRABEAM x-ray source (XRS). This factory-calibrated XRS is characterized by two depth-dose curves (DDCs) named "TARGIT" and "V4.0." Presently, the TARGIT DDC is used to treat patients enrolled in clinical trials; however, the V4.0 DDC is shown to better represent the delivered dose. Therefore, we reevaluate the delivered prescriptions under the TARGIT protocols using the V4.0 DDC. A 20-Gy dose was prescribed to the surface of the spherical applicator, and the TARGIT DDC was used to calculate the treatment time. For a constant treatment time, the V4.0 DDC was used to recalculate the dosimetry to evaluate differences in dose rate, dose, and equivalent dose in 2-Gy fractions (EQD2) for an α/ß = 3.5 Gy (endpoint of locoregional relapse). At the surface of the tumor bed (i.e., spherical applicator surface), the calculations using the V4.0 DDC predicted increased values for dose rate (43-16%), dose (28.6-23.2 Gy), and EQD2 (95-31%) for the 1.5- to 5.0-cm diameter spherical applicator sizes, respectively. In general, dosimetric differences are greatest for the 1.5-cm diameter spherical applicator. The results from this study can be interpreted as a reevaluation of dosimetry or the dangers of underdosage, which can occur if the V4.0 DDC is inadvertently used for TARGIT clinical trial patients. Because the INTRABEAM system is used in TARGIT clinical trials, accurate knowledge about absorbed dose is essential for making meaningful comparisons between radiation treatment modalities, and reproducible treatment delivery is imperative. The results of this study shed light on these concerns.


Assuntos
Neoplasias da Mama/radioterapia , Calibragem/normas , Cuidados Intraoperatórios , Imagens de Fantasmas , Planejamento da Radioterapia Assistida por Computador/normas , Relação Dose-Resposta à Radiação , Feminino , Humanos , Radiometria
17.
Biotechnol Prog ; 36(4): e2984, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32087049

RESUMO

Mechanistic modeling of chromatography processes is one of the most promising techniques for the digitalization of biopharmaceutical process development. Possible applications of chromatography models range from in silico process optimization in early phase development to in silico root cause investigation during manufacturing. Nonetheless, the cumbersome and complex model calibration still decelerates the implementation of mechanistic modeling in industry. Therefore, the industry demands model calibration strategies that ensure adequate model certainty in a limited amount of time. This study introduces a directed and straightforward approach for the calibration of pH-dependent, multicomponent steric mass action (SMA) isotherm models for industrial applications. In the case investigated, the method was applied to a monoclonal antibody (mAb) polishing step including four protein species. The developed strategy combined well-established theories of preparative chromatography (e.g. Yamamoto method) and allowed a systematic reduction of unknown model parameters to 7 from initially 32. Model uncertainty was reduced by designing two representative calibration experiments for the inverse estimation of remaining model parameters. Dedicated experiments with aggregate-enriched load material led to a significant reduction of model uncertainty for the estimates of this low-concentrated product-related impurity. The model was validated beyond the operating ranges of the final unit operation, enabling its application to late-stage downstream process development. With the proposed model calibration strategy, a systematic experimental design is provided, calibration effort is strongly reduced, and local minima are avoided.


Assuntos
Anticorpos Monoclonais/isolamento & purificação , Calibragem/normas , Resinas de Troca de Cátion/química , Cromatografia por Troca Iônica , Anticorpos Monoclonais/química
18.
Artigo em Inglês | MEDLINE | ID: mdl-32019060

RESUMO

To best represent reality, simulation models of environmental and health-related systems might be very nonlinear. Model calibration ideally identifies globally optimal sets of parameters to use for subsequent prediction. For a nonlinear system having multiple local optima, calibration can be tedious. For such a system, we contrast calibration results from PEST, a commonly used automated parameter estimation program versus several meta-heuristic global optimizers available as external packages for the Python computer language-the Gray Wolf Optimization (GWO) algorithm; the DYCORS optimizer framework with a Radial Basis Function surrogate simulator (DRB); and particle swarm optimization (PSO). We ran each optimizer 15 times, with nearly 10,000 MODFLOW simulations per run for the global optimizers, to calibrate a steady-state, groundwater flow simulation model of the complex Birds Nest aquifer, a three-layer system having 8 horizontal hydraulic conductivity zones and 25 head observation locations. In calibrating the eight hydraulic conductivity values, GWO averaged the best root mean squared error (RMSE) between observed and simulated heads-20 percent better (lower) than the next lowest optimizer, DRB. The best PEST run matched the best GWO RMSE, but both the average PEST RMSE and the range of PEST RMSE results were an order of magnitude larger than any of the global optimizers.


Assuntos
Comportamento Animal , Calibragem/normas , Água Subterrânea/normas , Algoritmos , Animais , Aves , Simulação por Computador , Objetivos , Modelos Teóricos
19.
Methods Appl Fluoresc ; 8(2): 025004, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-31995796

RESUMO

Spatial light modulation using cost efficient digital micromirror devices (DMD) is finding broad applications in fluorescence microscopy due to the reduction of phototoxicity and bleaching and the ability to manipulate proteins in optogenetic experiments. However, precise illumination by DMDs and their application to single-molecule localization microscopy (SMLM) remained a challenge because of non-linear distortions between the DMD and camera coordinate systems caused by optical components in the excitation and emission path. Here we develop a fast and easy to implement calibration procedure that determines these distortions and matches the DMD and camera coordinate system with a precision below the optical diffraction limit. As a result, a region from a fluorescence image can be selected with a higher precision for illumination compared to a rigid transformation allowed by manual alignment of the DMD. We first demonstrate the application of our precisely calibrated light modulation by performing a proof of concept fluorescence recovery after photobleaching experiment with the endoplasmic reticulum-localized protein IRE1 fused to GFP in budding yeast (S. cerevisiae). Next, we develop a spatially informed photoactivation approach for SMLM in which only regions of the cell that contain photoactivatable fluorescent proteins are selected for photoactivation. The reduced exposure of the cells to 405 nm light increased the possible imaging time by 44% until phototoxic effects cause a dominant fluorescence background and a change in cell morphology. As a result, the mean number of reliable single-molecule localizations was also significantly increased by 28%. Since the localization precision and the ability for single-molecule tracking is not altered compared to traditional photoactivation of the entire field of view, spatially informed photoactivation significantly improves the quality of SMLM images and single-molecule tracking data. Our precise calibration method therefore lays the foundation for improved SMLM with active feedback photoactivation far beyond the applications in this work.


Assuntos
Calibragem/normas , Fluorescência , Iluminação/métodos , Microscopia de Fluorescência/métodos
20.
Psychometrika ; 85(1): 35-55, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31531789

RESUMO

The maintenance of item bank is essential for continuously implementing adaptive tests. Calibration of new items online provides an opportunity to efficiently replenish items for the operational item bank. In this study, a new optimal design for online calibration (referred to as D-c) is proposed by incorporating the idea of original D-optimal design into the reformed D-optimal design proposed by van der Linden and Ren (Psychometrika 80:263-288, 2015) (denoted as D-VR design). To deal with the dependence of design criteria on the unknown item parameters of new items, Bayesian versions of the locally optimal designs (e.g., D-c and D-VR) are put forward by adding prior information to the new items. In the simulation implementation of the locally optimal designs, five calibration sample sizes were used to obtain different levels of estimation precision for the initial item parameters, and two approaches were used to obtain the prior distributions in Bayesian optimal designs. Results showed that the D-c design performed well and retired smaller number of new items than the D-VR design at almost all levels of examinee sample size; the Bayesian version of D-c using the prior obtained from the operational items worked better than that using the default priors in BILOG-MG and PARSCALE; and Bayesian optimal designs generally outperformed locally optimal designs when the initial item parameters of the new items were poorly estimated.


Assuntos
Calibragem/normas , Avaliação Educacional/métodos , Sistemas On-Line/instrumentação , Psicometria/métodos , Adaptação Fisiológica , Algoritmos , Teorema de Bayes , Simulação por Computador , Humanos , Modelos Estatísticos , Tamanho da Amostra
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