scholarly journals Estudo comparativo da densidade radiográfica de cimentos resinosos

Author(s):  
Ariadne De Araujo Goulart Pasquali ◽  
Mauricio Rufaiel Matson ◽  
Ricardo Raitz
Keyword(s):  

Introdução: A radiopacidade dos cimentos resinosos revela a presença de partículas densas, sendo útil na identificação da adaptação de peças cimentadas. Nosso objetivo é comparar a densidade óptica de diferentes cimentos resinosos pelos métodos radiográficos convencional e digital. Métodos: Para cada cimento escolhido (C&B, BisCem, Enforce) e para o grupo-controle (amálgama) foram confeccionados 5 corpos de prova (cp) idênticos em uma matriz de pvc. Cada um dos cp foi radiografado 3 vezes tanto pelo método convencional (utilizando-se filme periapical e aparelho de raios X intra-oral), quanto pelo digital (utilizando-se placas sensoras periapicais do sistema Digora-Soredex). As radiografias convencionais foram digitalizadas e a análise óptica da densidade dos materiais foi comparada pelo software Image J (NIH Image - Machintoch). Para o tratamento estatístico realizado pela ANOVA com 2 fatores e o teste complementar de Tukey com nível de significância de 5%, os valores considerados foram os obtidos a partir da média dos valores entre as diferentes radiografias e cp. Resultados: os valores de densidade pelo método convencional e digital foram respectivamente para cada material: 232,87 e 255 para o amálgama; 136,73 e 136,24 para o Enforce; 135,44 e 148,51 para o Bis-Cem e 125,24 e 58,97 para o C&B. Conclusões: Não houve diferenças significantes entre os métodos radiográficos (p=0,069%). Foram verificadas diferenças significantes entre os materiais (p=0,00), em ambos os métodos, exceto entre o Enforce e o BisCem, que obtiveram média de tons de cinza semelhantes. O cimento C&B mostrou as menores médias de tons de cinza.

Author(s):  
John R. Porter

New ceramic fibers, currently in various stages of commercial development, have been consolidated in intermetallic matrices such as γ-TiAl and FeAl. Fiber types include SiC, TiB2 and polycrystalline and single crystal Al2O3. This work required the development of techniques to characterize the thermochemical stability of these fibers in different matrices.SEM/EDS elemental mapping was used for this work. To obtain qualitative compositional/spatial information, the best realistically achievable counting statistics were required. We established that 128 × 128 maps, acquired with a 20 KeV accelerating voltage, 3 sec. live time per pixel (total mapping time, 18 h) and with beam current adjusted to give 30% dead time, provided adequate image quality at a magnification of 800X. The maps were acquired, with backgrounds subtracted, using a Noran TN 5500 EDS system. The images and maps were transferred to a Macintosh and converted into TIFF files using either TIFF Maker, or TNtolMAGE, a Microsoft QuickBASIC program developed at the Science Center. From TIFF files, images and maps were opened in either NIH Image or Adobe Photoshop for processing and analysis and printed from Microsoft Powerpoint on a Kodak XL7700 dye transfer image printer.


Author(s):  
M. T. Dineen

The production of rubber modified thermoplastics can exceed rates of 30,000 pounds per hour. If a production plant needs to equilibrate or has an upset, that means operating costs and lost revenue. Results of transmission electron microscopy (TEM) can be used for process adjustments to minimize product loss. Conventional TEM, however, is not a rapid turnaround technique. The TEM process was examined, and it was determined that 50% of the time it took to complete a polymer sample was related to film processing, even when using automated equipment. By replacing the conventional film portion of the process with a commercially available system to digitally acquire the TEM image, a production plant can have the same TEM image in the control room within 1.5 hours of sampling.A Hitachi H-600 TEM Operated at 100 kV with a tungsten filament was retrofitted with a SEMICAPS™ image collection and processing workstation and a KODAK MEGAPLUS™ charged coupled device (CCD) camera (Fig. 1). Media Cybernetics Image-Pro Plus software was included, and connections to a Phaser II SDX printer and the network were made. Network printers and other PC and Mac software (e.g. NIH Image) were available. By using digital acquisition and processing, the time it takes to produce a hard copy of a digital image is greatly reduced compared to the time it takes to process film.


Author(s):  
John Mansfield

Advances in camera technology and digital instrument control have meant that in modern microscopy, the image that was, in the past, typically recorded on a piece of film is now recorded directly into a computer. The transfer of the analog image seen in the microscope to the digitized picture in the computer does not mean, however, that the problems associated with recording images, analyzing them, and preparing them for publication, have all miraculously been solved. The steps involved in the recording an image to film remain largely intact in the digital world. The image is recorded, prepared for measurement in some way, analyzed, and then prepared for presentation.Digital image acquisition schemes are largely the realm of the microscope manufacturers, however, there are also a multitude of “homemade” acquisition systems in microscope laboratories around the world. It is not the mission of this tutorial to deal with the various acquisition systems, but rather to introduce the novice user to rudimentary image processing and measurement.


1999 ◽  
Vol 25 (4) ◽  
pp. 403-414 ◽  
Author(s):  
Christopher L Liner
Keyword(s):  

1998 ◽  
Vol 8 (4) ◽  
pp. 219-222 ◽  
Author(s):  
P. Kenny ◽  
J. Rice ◽  
B. McCormack ◽  
S.K. O'Rourke

The femoral cement mantle was reproduced in a laboratory model. This model consisted of rigid plastic tubing, 10 cm long, with an internal diameter of 2.5 cm. One end of the tube was sealed to simulate an intramedullary plug. A wooden model was used to simulate the femoral component of a total hip arthroplasty. Bone cement was mixed in a glass bowl with a steel spatula in a standardised manner for two minutes. In all cases the model femur was filled with bone cement and a regular mantle around the wooden “femoral stem” was observed. Pores were present on the cut surface of all of the specimens. The pore density (No. of pores per unit area) was measured using an NIH image programme and was found to be dramatically reduced in the experimental cement mantles, when compared to the control specimens. The porosity in the cement mantles produced by vacuum loading the gun was significantly lower (p< 0.001) than that in the mantles produced by the manually loaded guns.


PLoS ONE ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. e0211629 ◽  
Author(s):  
Douglas E. Long ◽  
Alejandro G. Villasante Tezanos ◽  
James N. Wise ◽  
Philip A. Kern ◽  
Marcas M. Bamman ◽  
...  

2014 ◽  
Vol 32 (26_suppl) ◽  
pp. 40-40 ◽  
Author(s):  
Neil M. Iyengar ◽  
Patrick Glyn Morris ◽  
Xi Kathy Zhou ◽  
Ayca Gucalp ◽  
Dilip D. Giri ◽  
...  

40 Background: Chronic inflammation predisposes to several malignancies. We previously demonstrated an obesity → inflammation → aromatase axis in breast tissue. As obesity is a risk factor for postmenopausal (PoM) but not premenopausal (PreM) breast cancer (BC), we examined whether menopause and body mass index (BMI) independently impact breast white adipose tissue (WAT) inflammation. Methods: WAT was prospectively collected from patients (pts) from 04/10 to 08/13. WAT inflammation, detected by CD68 immunohistochemistry, was defined by the presence of dead or dying adipocytes surrounded by an envelope of macrophages known as crown-like structures of the breast (CLS-B). WAT area was measured with NIH Image J. Adipocyte diameter was measured with Canvas 11 Software. Endpoints were 1) CLS-B (+/-) and 2) CLS-B/cm2. Clinicopathologic associations with CLS-B were analyzed by logistic regression and Fisher’s exact test. Results: WAT (237 mastectomies, 13 abdominal reconstructions) was obtained from 238 pts; median age 48 (range 22 to 90). CLS-B occurrence and number of CLS-B/cm2 were greater in overweight/obese (BMI ≥ 25) and PoM pts compared to lean (BMI < 25) and PreM pts (Table). In multivariable analyses, BMI and PoM state were independently associated with CLS-B presence (p <.01 and p = .04) and greater CLS-B/cm2(p < .01 and p = .01). PoM pts had larger mean adipocyte diameter (105.2 +/- 14.0 μ) than PreM pts (95.7 +/-15.6 μ; p < 0.01). In pts with bilateral breast WAT and abdominal WAT, concordant CLS status (+/-) was found in 49/63 (78%) and 10/13 (77%) pts, respectively. Conclusions: Breast WAT inflammation (both presence and severity), which we have previously linked to increased aromatase activity, is associated with both increased BMI and menopause. These findings can explain the increased risk of estrogen receptor–positive BC with obesity and PoM status and may also provide targets for rational therapies. [Table: see text]


2015 ◽  
Vol 68 (1-2) ◽  
pp. 10-16
Author(s):  
Milan Drobac ◽  
Igor Stojanac ◽  
Bojana Ramic ◽  
Milica Premovic ◽  
Ljubomir Petrovic

Introduction. The ultimate goal in restorative dentistry has always been to achieve strong and permanent bond between the dental tissues and filling materials. It is not easy to achieve this task because the bonding process is different for enamel and dentin - dentin is more humid and more organic than enamel. It is moisture and organic nature of dentin that make this hard tissue very complex to achieve adhesive bond. One of the first and most widely used tools for examining the adhesive bond between hard dental tissues and composite restorative materials is scanning electron microscopy. The aim of this study was scanning electron microscopy analyzes the interfacial micro morphology of total-etch and self-etch adhesives. Material and Methods. Micro morphological characteristics of interface between totaletch adhesive (Prime & Bond NT) in combination with the corresponding composite (Ceram X Mono) were compared with those of self-etching adhesive (AdheSE One) in combination with the corresponding composite (Tetric EvoCeram). The specimens were observed under 1000 x magnification of scanning electron microscopy (JEOL, JSM-6460 Low Vacuum). Measurement of the thickness of the hybrid layer of the examined composite systems was performed with the software of the device used (NIH Image ?nalyser). Results. Micromorphological analysis of interface showed that the hybrid layer in sound dentin was well formed, its average thickness being 2.68 ?m, with a large number of resin tags and a large amount of lateral branches for specimens with a composite system Prime & Bond NT - Ceram X Mono. However, the specimens with composite systems Adhese One - Tetric EvoCeram did not show the presence of hybrid layer and the resin tags were poorly represented. Conclusion. The results of this study suggest that total-etch adhesives bond better with sound dentin than self-etch adhesives.


2013 ◽  
pp. 31-36 ◽  
Author(s):  
Catalina Lapuente ◽  
Carlos A Rengifo ◽  
Marco F Ávila ◽  
Angel E Céspedes

Introduction: The pathophysiology of cerebral ischemia is essential for early diagnosis, neurologic recovery, the early onset of drug treatment and the prognosis of ischemic events. Experimental models of cerebral ischemiac an be used to evaluate the cellular response phenomena and possible neurological protection by drugs. Objective: To characterize the cellular changes in the neuronal population and astrocytic response by the effect of Dimethyl Sulfoxide (DMSO) on a model of ischemia caused by cerebral embolism. Methods: Twenty Wistar rats were divided into four groups (n= 5). The infarct was induced with α-bovinethrombin (40 NIH/U). The treated group received 90 mg (100 µL) of DMSO in saline (1:1 v/v) intraperitoneally for 5 days; ischemic controls received only NaCl (placebo) and two non-ischemic groups (simulated) received NaCl and DMSO respectively. We evaluated the neuronal (anti-NeuN) and astrocytic immune-reactivity (anti-GFAP). The results were analyzed by densitometry (NIH Image J-Fiji 1.45 software) and analysis of variance (ANOVA) with the Graph pad software (Prism 5). Results: Cerebral embolism induced reproducible and reliable lesions in the cortex and hippocampus (CA1). similar to those of focal models. DMSO did not reverse the loss of post-ischemia neuronal immune-reactivity, but prevented the morphological damage of neurons, and significantly reduced astrocytic hyperactivity in thesomato-sensory cortex and CA1 (P <0.001). Conclusions: The regulatory effect of DMSO on astrocyte hyperreactivity and neuronal-astroglial cytoarchitecture, gives it potential neuroprotective properties for the treatment of thromboembolic cerebral ischemiain the acute phase.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 906E-906 ◽  
Author(s):  
Gary W. Stutte ◽  
Elizabeth C. Stryjewski

Manual methods for estimating root length are tedious and time-consuming. Image capture and analysis systems can be used to obtain precise measurements of root length and growth angle. Root activity can also be determined through analysis of the mean pixel intensity of a digitized image. Both commercial (the IBM-compatible ICAS System) and public domain (the Macintosh-based NIH Image) image capture and analysis software have been used to analyze intact root systems. Examples of ICAS classification of hydroponic and soil-grown root systems will be presented. Advantages of the NIH Image software for analysis of micro-gravity experiments aboard the Space Shuttle will be discussed.


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