Congruencia entre modelos dentales impresos 3D y el archivo digital de origen: estudio in vitro comparativo de 5 impresoras 3D / Congruence between 3D printed dental models and the original digital file: comparative in vitro study of 5 3D printers

Este trabajo tuvo como objetivo conocer la fiabilidad de la impresora 3D (i3D) aditiva por Matriz de Proceso Digital de Luz (MDLP) Hellbot modelo Apolo®, a través de verificar la congruencia dimensional entre las mallas de modelos impresos (MMi) y su correspondiente archivo digital de origen (MMo), obtenido del software de planificación ortodontica Orchestrate 3D® (O3D). Para determinar su uso en odontología y sus posibilidades clínicas, fue comparada entre cinco i3D de manufactura aditiva, dos DLP, dos por estereolitografía (SLA) y una por Depósito de Material Fundido (FDM). La elección de las cinco i3D se fundamentó en su valor de mercado, intentando abarcar la mayor diversidad argentina disponible. Veinte modelos fueron impresos con cada i3D y escaneados con Escáner Intraoral (IOS) Carestream modelo 3600® (Cs3600). Las 120 MMi fueron importadas dentro del programa de ingeniería inversa Geomagic® Control X® (Cx) para su análisis 3D, consistiendo en la superposición de MMo con cada una de las MMi. Luego, una evaluación cualitativa de la desviación entre la MMi y MMo fue realizada. Un análisis estadístico cuidadoso fue realizado obteniendo como resultado comparaciones en 3d y 2d. Las coincidencias metrológicas en la superposición tridimensional permitieron un análisis exhaustivo y fácilmente reconocible a través de mapas colorimétricos. En el análisis bidimensional se plantearon planos referenciados dentariamente desde la MMo, para hacer coincidir las mediciones desde el mismo punto de partida dentaria. Los resultados fueron satisfactorios y muy alentadores. Las probabilidades de obtener rangos de variabilidad equivalentes a +/- 50µm fueron de un 40,35 % y de +/- 100µm un 71,04 %. Por lo tanto, te- niendo en cuenta las exigencias de congruencia dimensional clínicas de precisión y exactitud a las cuales es sometida nuestra profesión odontológica, se evitan problemas clínicos arrastrados por los errores dimensionales en la manufactura (Cam) (AU)

The objective of this study was to determine the reliability of the Hellbot Apollo® model additive 3D printer (i3D) by Matrix Digital Light Processing (MDLP) by verifying the dimensional congruence between the printed model meshes (MMi) and their corresponding digital source file (MMo), obtained from the Orchestrate 3D® (O3D) orthodontic planning software. A comparison was made between five i3D of additive manufacturing, two DLP, two by stereolithography (SLA), and one by Fused Material Deposition (FDM), to determine its use in dentistry and its clinical possibilities. The choice of the five i3D was based on their market value, trying to cover most of the Argentinean diversity available. Twenty models were printed with each i3D and scanned with Carestream Intraoral Scanner (IOS) model 3600® (Cs3600). The 120 MMi were imported into the reverse engineering program Geomagic® Control X® (Cx) for 3D analysis, consisting of overlaying MMo with each MMi. Then, a qualitative evaluation of the deviation between MMi and MMo. Also, a careful statistical analysis was performed, resulting in 3d and 2d comparisons. Metrological coincidences in three-dimensional overlay allowed a comprehensive and easily recognizable analysis through colorimetric maps. In the two-dimensional analysis, dentally referenced planes were proposed from the MMo, to match the measurements from the same dental starting point. The results were satisfactory and very encouraging. The probabilities of obtaining ranges of variability equivalent to +/- 50µm were 40.35 % and +/- 100µm 71.04 %. Therefore, considering the demands of clinical dimensional congruence, precision, and accuracy to which our dental profession it is subjected, clinical problems caused by dimensional errors in manufacturing (Cam) are avoided (AU)

A Phantom-based Investigation Into the Influence of Low Tube Potential and Matrix Size on Radiation Dose and Image Quality for a 128 Slice Abdominopelvic Ct Protocol

@#Introduction: Reducing radiation dose for CT examinations has been accompanied by an increase in image noise. Studies have highlighted the application of a higher matrix size for improving image quality when assessing the lungs. This study aims to evaluate the influence of a low kVp and higher matrix size on radiation dose and image quality for abdominopelvic CT. Methods: This experiment was done on a 32 cm body phantom and scanned using a 128 slice CT scanner. The study utilised various combinations of kVp settings (140, 120, 100, 80 & 70) and matrix sizes (1024, 768 & 512). The image obtained was analysed objectively and subjectively. For objective analysis, we calculated SNR, and CNR. For subjective analysis, two radiologists evaluated the image in a 3-point scoring scale. Results: The study reported an increase in SNR (0.8%) and CNR (46%) at 120 kVp when increasing the matrix size from 512 x 512 to 768 x 768. Similarly, there was an increase of 14.5 % and 56.4 % in CNR and SNR using 1024 matrix size. The DLP was reduced by 4.5%, 50% and 70.6 % using 100, 80 and 70 kVp respectively. However, there was no change in DLP with higher matrix sizes. Conclusion: The study reported a combination of 100 kVp and 768 matrix size resulted in an almost similar (↓0.9 %) SNR and improved CNR (↑46.4 %) compared to 120 kVp and 512 matrix size. Qualitative analysis also showed a similar image quality with decreased radiation dose for abdominopelvic CT.

Integrated 3D bioprinting-based geometry-control strategy for fabricating corneal substitutes / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Background: The shortage of donor corneas is a severe global issue, and hence the development of corneal alternatives is imperative and urgent. Although attempts to produce artificial cornea substitutes by tissue engineering have made some positive progress, many problems remain that hamper their clinical application worldwide. For example, the curvature of tissue-engineered cornea substitutes cannot be designed to fit the bulbus oculi of patients. Objective: To overcome these limitations, in this paper, we present a novel integrated three-dimensional (3D) bioprinting-based cornea substitute fabrication strategy to realize design, customized fabrication, and evaluation of multi-layer hollow structures with complicated surfaces. Methods: The key rationale for this method is to combine digital light processing (DLP) and extrusion bioprinting into an integrated 3D cornea bioprinting system. A designable and personalized corneal substitute was designed based on mathematical modelling and a computer tomography scan of a natural cornea. The printed corneal substitute was evaluated based on biomechanical analysis, weight, structural integrity, and fit. Results: The results revealed that the fabrication of high water content and highly transparent curved films with geometric features designed according to the natural human cornea can be achieved using a rapid, simple, and low-cost manufacturing process with a high repetition rate and quality. Conclusions: This study demonstrated the feasibility of customized design, analysis, and fabrication of a corneal substitute. The programmability of this method opens up the possibility of producing substitutes for other cornea-like shell structures with different scale and geometry features, such as the glomerulus, atrium, and oophoron.

Integrated 3D bioprinting-based geometry-control strategy for fabricating corneal substitutes / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

BACKGROUND@#The shortage of donor corneas is a severe global issue, and hence the development of corneal alternatives is imperative and urgent. Although attempts to produce artificial cornea substitutes by tissue engineering have made some positive progress, many problems remain that hamper their clinical application worldwide. For example, the curvature of tissue-engineered cornea substitutes cannot be designed to fit the bulbus oculi of patients.@*OBJECTIVE@#To overcome these limitations, in this paper, we present a novel integrated three-dimensional (3D) bioprinting-based cornea substitute fabrication strategy to realize design, customized fabrication, and evaluation of multi-layer hollow structures with complicated surfaces.@*METHODS@#The key rationale for this method is to combine digital light processing (DLP) and extrusion bioprinting into an integrated 3D cornea bioprinting system. A designable and personalized corneal substitute was designed based on mathematical modelling and a computer tomography scan of a natural cornea. The printed corneal substitute was evaluated based on biomechanical analysis, weight, structural integrity, and fit.@*RESULTS@#The results revealed that the fabrication of high water content and highly transparent curved films with geometric features designed according to the natural human cornea can be achieved using a rapid, simple, and low-cost manufacturing process with a high repetition rate and quality.@*CONCLUSIONS@#This study demonstrated the feasibility of customized design, analysis, and fabrication of a corneal substitute. The programmability of this method opens up the possibility of producing substitutes for other cornea-like shell structures with different scale and geometry features, such as the glomerulus, atrium, and oophoron.

ULK1 and JNK are involved in mitophagy incurred by LRRK2 G2019S expression

Mutations in LR RK2 (Leucine rich repeat kinase 2) are a major cause of Parkinson's disease (PD). We and others reported recently that expression of the pathogenic gainof-function mutant form of LRRK2, LRRK2 G2019S, induces mitochondrial fission in neurons through DLP1. Here we provide evidence that expression of LRRK2 G2019S stimulates mitochondria loss or mitophagy. We have characterized several LRRK2 interacting proteins and found that LRRK2 interacts with ULK1 which plays an essential role in autophagy. Knockdown of either ULK1 or DLP1 expression with shRNAs suppresses LRRK2 G2019S expression-induced mitochondrial clearance, suggesting that LRRK2 G2019S expression induces mitochondrial fission through DLP1 followed by mitophagy via an ULK1 dependent pathway. In addition to ULK1, we found that LRRK2 interacts with the endogenous MKK4/7, JIP3 and coordinates with them in the activation of JNK signaling. Interestingly, LRRK2 G2019S-induced loss of mitochondria can also be suppressed by 3 different JNK inhibitors, implying the involvement of the JNK pathway in the pathogenic mechanism of mutated LRRK2. Thus our findings may provide an insight into the complicated pathogenesis of PD as well as some clues to the development of novel therapeutic strategies.

Estimate of Radiation Doses in MDCT Using Patient Weight / 의학물리

The purpose of this study provides measurements of radiation dose from MDCT of head, chest, abdomen and pelvic examinations. A series of dose quantities that are measured of patient weight to compare the dose received during MDCT examinations. Data collected included: weight together with CT dose descriptors, volume CT dose index (CTDIvol) and dose length product (DLP). The effective dose was also estimated and served as collective dose estimation data. Data from 1,774 adult patients attending for a CT examination of the head (n=520) or chest (n=531) or abdomen (n=724) was obtained from spiral CT units using a same CT protocol. Mean values of CTDIvol was a range of 48.6 mGy for head and 6.9, 10.5 mGy for chest, abdomen examinations, respectively. And mean values of DLP was range of 1,604 mGy.cm for head, 250 mGy.cm for chest, 575 mGy.cm for abdomen examinations, respectively. Mean effective dose values for head, chest, abdominal CT were 3.6, 4.2, and 8.6 mSv, respectively. The degree of CTDIvol and DLP was a positive correlation with weight. And there was a positive correlation for weight versus CTDIvol (r2=0.62), DLP (r2=0.694) in chest. And head was also positive correlation with weight versus CTDIvol (r2=0.691), DLP (r2=0.741). We conclude that CTDIvol and DLP is an important determinant of weight within the CT examinations. The results for this study suggest that CT protocol should be tailored according to patient weight.

O papel da expressão de Bcl-2 em material obtido por PAAF no diagnóstico de doenças linfoproliferativas B / The role of Bcl-2 expression in fine needle aspiration specimens for the diagnostic accuracy in lymphoproliferative diseases

INTRODUÇÃO: O diagnóstico das doenças linfoproliferativas (DLP) tradicionalmente baseia-se no estudo histológico dos linfonodos (LN) acrescido de imuno-histoquímica. A imunofenotipagem (IFT) pela citometria de fluxo (CF) é uma ferramenta sensível e rápida, que pode ser aplicada nas DLP, em material obtido por punção aspirativa por agulha fina (PAAF) de LN. O Bcl-2 é um proto-oncogene que se expressa em várias DLP, porém em níveis especialmente elevados no linfoma folicular (LF). OBJETIVOS: Diagnosticar DLP, através de morfologia e imunofenotipagem por CF, em amostras obtidas por PAAF de LN. MATERIAL e MÉTODO: Amostras de 25 pacientes com adenopatias e de duas tonsilas reacionais foram analisadas pela morfologia e IFT, utilizando um painel inicial de AcMo (CD3, CD4, CD8, CD19, anti-kappa; e anti-lambda;), ampliado conforme a necessidade (CD5, CD10, CD11c, CD23, CD79b, sIgM, FMC-7 e Bcl-2). Os resultados foram comparados com a histologia. RESULTADOS:Dos 25 casos, quatro foram classificados como reacionais e 21 como DLP-B, havendo concordância com resultados histológicos em todos os casos. A intensidade média de fluorescência (IMF) da Bcl-2 no LF (19,92) foi maior que em outras DLP-B (11,93) e que nos controles (3,49) (p = 0,032). CONCLUSÃO:A PAAF de LN combinada com a citomorfologia e a IFT por CF permite uma rápida diferenciação entre os processos reacionais e linfoproliferativos B. A elevada expressão da Bcl-2 nos LFs pela citometria mostra sua utilidade no diagnóstico do tipo mais freqüente das DLP-B. A obtenção de células por PAAF requer treinamento e recomendamos mais de uma punção.

BACKGROUND: The diagnosis of lymphoproliferative disorders (LPD) is routinely made through histological and immunohistochemical analysis of lymph nodes. Immunophenotyping by flow cytometry (FC) is a sensitive and fast tool, which may be applied in samples obtained through fine needle aspiration for the diagnosis of LPD. Bcl-2 is a proto-oncogene that appears in several LPD and it has a significantly high expression in follicular lymphomas. OBJECTIVES: to diagnose LPD in FNA samples through morphology and flow cytometry immunophenotyping. MATERIAL AND METHODS: Samples from 25 patients with lymphadenopathies and 2 reactive tonsils were studied through morphology and immunophenotyping. The antigens expressions were evaluated by using a screening panel of monoclonal antibodies (CD3, CD4, CD8, CD19, light chains kappa; and lambda), followed by CD5, CD10, CD11c, CD23, CD79b, sIgM, FMC-7 and Bcl-2 when required. The results were compared with histology. RESULTS:Four out of 25 samples were reactive processes and 21were B-LPD. In all cases there was consistency with histological results. The mean fluorescence intensity of Bcl-2 in Follicular Lymphoma (19.92) was higher compared with other lymphoproliferative diseases (11.93) and controls (3.49) (p = 0.032). CONCLUSION: Fine needle aspiration of lymph nodes associated with cytomorphology and flow cytometry immunophenotyping allows a fast differentiation between reactive processes and B lymphoproliferative cases. The high expression of Bcl-2 by cytometry shows its usefulness in the diagnosis of the most frequent type of B-LPD. Fine needle aspiration sampling requires training and more than one aspiration is recommended.