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PubMed1999

[Color Doppler-echo in rheumatoid arthritis with extra-articular location. Preliminary experience].

INTRODUCTION: Chronic inflammation in rheumatoid arthritis usually involves articular synovia and extends to other joint components such as bursae, tendons and sheaths. Conventional US with high frequency transducers is an accurate tool for assessing abnormal changes in evolutive rheumatoid arthritis. We investigated the role of color and power Doppler imaging in staging extra-articular involvement, monitoring local inflammatory changes and drug treatment response. MATERIAL AND METHODS: We used a color Doppler unit with a 5-10 Mhz transducer and automatic power Doppler switch to examine 23 patients with tenosynovitis of the flexor (4/23) and extensor (8/23) tendons of the hand, Achilles (6/23) and posterior tibial (3/23) tendons, and long head of biceps (2/23) in acute rheumatoid arthritis. Only minimal pressure was exerted with the probe on the patients' skin to avoid compression and collapse of blood vessels. Ten normal volunteers were also examined as a control group. RESULTS: In all 23 acute rheumatoid arthritis patients, conventional US showed tendon involvement with intra-articular fluid, thickened tendons with partial tear and markedly hypoechoic thickened sheaths. Color signals were shown in all patients. Mid-caliber vessels were visualized coursing straight from the sheath deep into the tendon. Intra-articular signals were seen in 10/12 patients only. Spectral analysis showed arterial flow, with RI ranging .40-.70. Power Doppler added no important information, but improved vessel depiction relative to color Doppler thanks to its higher accuracy in detecting flow signals. There were no color signals in the tendons of the 10 healthy volunteers in the control group. No color signals were seen in both joints and tendons in 12 patients submitted to medical treatment. CONCLUSION: Color and power Doppler can be a necessary and useful integration to high resolution US for flow mapping in rheumatoid arthritis patients with tendon and extra-articular involvement. These modes depict local circulation changes related to disease stage and treatment response.

Adult↗

PubMedDate not supplied

Polymerization color changes of esthetic restoratives.

The color changes of three different types of tooth-colored restoratives during polymerization were investigated using colorimetry. L*, a*, b* color parameters of five different shades of Z100 (a mini-filled composite resin), Fuji II LC (a resin-modified glass-ionomer cement), and Dyract (a polyacid-modified composite resin) were taken precure and postcure. The results showed that the restoratives evaluated all underwent color changes during polymerization. The polymerization changes in color parameters were shade and not material dependent. Changes in L* parameter or lightness during polymerization were significant for all material and shade combinations and had the greatest influence on the overall polymerization color change. As the color change was perceivable by the human eye for most shades of materials, the clinical practice of polymerizing some material on, or adjacent to, the undried tooth to confirm shades of esthetic restoratives before restorative procedures is prudent.

Colorimetry↗

PubMedDate not supplied

A study of the bond strength and color of ultralow-fusing porcelain.

PURPOSE: The purpose of this study was to investigate the effects of different bonding agents, surface roughness, and acid pickling on the bond strength and color of ultralow-fusing porcelain fused to gold alloy. MATERIALS AND METHODS: Porcelain-metal specimens were made to 25 mm x 3 mm x 0.5 mm with a 1-mm porcelain thickness. A 3-point bending test was used to evaluate the bond strength. The color of the porcelain was measured using a dental chromameter, and the data were processed in the CIE Lab system. The color difference (delta E*) was calculated for the tested groups. RESULTS: Good bond strength and color could be achieved regardless of the use and type of bonding agent. Surface roughness and acid pickling had more effect on the bond strength than on color. CONCLUSION: The type of the bonding agent, surface roughness, and acid pickling influenced the bond strength but had minimal effects on the color of ultralow-fusing porcelain. This ultralow-fusing porcelain could produce a color closer to the Vita shade than the conventional low-fusing porcelain.

Acid Etching, Dental↗

PubMed2000

Practical color vision tests for air traffic control applicants: en route center and terminal facilities.

BACKGROUND: Two practical color vision tests were developed and validated for use in screening Air Traffic Control Specialist (ATCS) applicants for work at en route center or terminal facilities. The development of the tests involved careful reproduction/simulation of color-coded materials from the most demanding, safety-critical color task performed in each type of facility. METHODS: The tests were evaluated using 106 subjects with normal color vision and 85 with color vision deficiency. The en route center test, named the Flight Progress Strips Test (FPST), required the identification of critical red/black coding in computer printing and handwriting on flight progress strips. The terminal option test, named the Aviation Lights Test (ALT), simulated red/green/white aircraft lights that must be identified in night ATC tower operations. Color-coding is a non-redundant source of safety-critical information in both tasks. RESULTS: The FPST was validated by direct comparison of responses to strip reproductions with responses to the original flight progress strips and a set of strips selected independently. Validity was high; Kappa = 0.91 with original strips as the validation criterion and 0.86 with different strips. The light point stimuli of the ALT were validated physically with a spectroradiometer. The reliabilities of the FPST and ALT were estimated with Chronbach's alpha as 0.93 and 0.98, respectively. CONCLUSIONS: The high job-relevance, validity, and reliability of these tests increases the effectiveness and fairness of ATCS color vision testing.

Adolescent↗

PubMed2001

[Usefulness of three-dimensional color Doppler sonography for the differential diagnosis of subpleural lesions].

The purpose of our investigation was to assess the usefulness of three-dimensional color Doppler sonography (velocity mode and power mode) for the differential diagnosis of subpleural lesions. Thirty lesions (11 pneumonias, 5 lung abscesses, 11 primary lung cancers, 3 metastatic lung cancers) were examined. Three-dimensional images were reconstructed by a maximum intensity projection method. Three-dimensional representations of intralesional blood flow became available for all lesions approximately 11 seconds after scanning. In every case, the entire vasculature of the tumor, the pneumonia, the abscess, or the inflamed region of the lung was appreciated more easily from three-dimensional images than from two-dimensional images. We classified the color flow pattern of subpleural lesions depicted by color flow imaging into seven groups. Color flow was depicted better by the three-dimensional color Doppler power mode than the velocity mode. Three-dimensional color flow patterns observed in power mode, patterns of the pneumonias and the lung cancers differed significantly. Our results suggest that the three-dimensional color Doppler power mode is useful for the differential diagnosis of subpleural lesions.

Adult↗

PubMed2000

Effect of mouthwash and accelerated aging on the color stability of esthetic restorative materials.

PURPOSE: To evaluate the color stability of esthetic restorative materials after immersion in mouthwashes and accelerated aging. MATERIALS AND METHODS: Compomers and resin-based composites (RBC) were measured at baseline and repeatedly after immersion in three kinds of mouthwash (Listerine, Peridex, Rembrandt Age Defying) for 24 hrs and 7 days, and after aging for 150 kJ/m2. Color was measured according to CIE L*a*b* color scale on a reflection spectrophotometer. RESULTS: After immersion for 7 days, the mouthwash groups did not produce significantly higher color changes than the distilled water group, except with some mouthwashes used with Tetric-Ceram. After immersion for 7 days and aging for 150 kJ/m2, the mouthwash groups did not produce significantly higher color changes than the distilled water group. Aging in weathering chamber produced color change (deltaE*) of 1.1-3.9, which was mainly influenced by the material. With some exceptions, the color changes from immersion of the RBCs and compomers in mouthwashes were not perceptible (deltaE*<3.3).

Analysis of Variance↗

PubMed2001

Color and optical properties of resin-based composites for bleached teeth after polymerization and accelerated aging.

PURPOSE: To determine changes in color and optical properties after polymerization and accelerated aging of white resin-based composites (RBCs) used to restore bleached teeth and compare them with those of conventional shades. MATERIALS AND METHODS: Four white shades and two conventional shades (A2, A3) of two different brands of RBCs (Vitalescence, Synergy) were measured before and after polymerization and after accelerated aging for 150 kJ/m2. Color was measured according to CIE L*a*b* color scale on a reflection spectrophotometer, and scattering coefficient, absorption coefficient, contrast ratio and translucency parameter were calculated. RESULTS: After curing, the color change ( E*) of white RBC was not significantly higher than that of conventional shade (P= 0.05). Color change after curing was positively influenced by the change of K (beta = 0.55), and negatively influenced by the changes of L*, b* and S (beta = -0.34, -0.95 and -0.70, respectively). After aging for 150 kJ/m2, the color changes of white RBCs were 2.4 and 5.8, and those of conventional shade were 1.7 and 2.9, respectively. Higher a* and b* values had a negative influence on the color change for both polymerization and aging.

Color↗

PubMedDate not supplied

Effect of toothbrushing on the material loss, roughness, and color of intrinsically and extrinsically stained porcelain used in metal-ceramic restorations: an in vitro study.

PURPOSE: Because of abrasion by toothbrushing, dental materials in the oral cavity are subjected to substance loss to a different extent depending on the hardness of the material. This study investigated the color-change effect of substance loss and change of roughness resulting from toothbrushing of internally and externally stained metal ceramic. MATERIALS AND METHODS: Metal-ceramic specimens 15 mm in diameter and 2 mm thick were made. Blue colorant suspension was applied over the enamel porcelain (enamel-stained), in the body porcelain (dentin-stained), and over the opaque porcelain (opaque-stained). One group was not stained. Each group was made up of seven samples. All specimens were brushed in an experimental device. Material loss, roughness measurements, and spectrophotometric evaluations were made before and after brushing. Overall color change, chroma change, and value change were calculated with the use of the CIE-LAB uniform color scale. RESULTS: Significant substance loss as a result of brushing was observed. No significant differences between chroma changes, between value changes of different groups, or between overall color changes of dentin- and enamel-stained groups were found. The difference between overall color changes of opaque-dentin and opaque-enamel stained groups was statistically significant. CONCLUSION: Staining should be done as deeply as possible to obtain durable color appearance.

Dental Porcelain↗

PubMedDate not supplied

Changes in translucency and color of particulate filler composite resins.

PURPOSE: The purpose of this study was to examine changes in translucency and color of particulate filler composite resins that can be fabricated into metal-free crowns. MATERIALS AND METHODS: Eight types of materials were used in this study. The particulate filler composite resins were represented by Artglass, BelleGlass, Estenia, Gradia, and Targis. Herculite XRV and Solidex were the conventional composite resins for crowns and fixed partial denture facings, and Empress was the ceramic material. Disks with a thickness of 1.0 mm were fabricated from each material and subjected to an accelerated test by immersion in 60 degrees C distilled water for up to 8 weeks. Color measurements were made before and after water immersion. Changes in translucency were evaluated by determining the contrast ratio, and changes in color were evaluated by determining color difference. RESULTS: After water immersion, Targis and Solidex demonstrated a significant increase in contrast ratio (6% to 7%) and a decrease in translucency. A color difference of more than 2.0, a visually perceptible value, was found for Targis, Gradia, and Solidex. However, the maximum color difference for these was 3.0, a value that would be considered clinically acceptable. CONCLUSION: Within the limitations of this study, the particulate filler composite resins were stable in both translucency and color.

Aluminum Silicates↗

PubMedDate not supplied

Enhanced color flows in hepatic tumors.

BACKGROUND/AIMS: The study was to utilize both color Doppler sonography and power Doppler sonography to analyze the enhancement characteristics of hepatic tumors known to have a clinical or histologically confirmed diagnosis of hepatocellular carcinoma, hemangioma, or focal nodular hyperplasia. METHODOLOGY: Twenty-two hepatocellular carcinomas, 6 hemangiomas, and 2 focal nodular hyperplasias were observed with color Doppler sonography and power Doppler sonography before and after contrast agent (Levovist) administration. Color Doppler sonography and power Doppler sonography were used to detect the intratumoral vasculature and their sensitivity would be evaluated. RESULTS: Significant improvement in the detection of color flow signals was obtained in hepatocellular carcinomas after administering Levovist (32% (7/22) vs. 91% (20/22); p = 0.0002), but it was not significant in hemangiomas (0% (0/6) vs. 33% (2/6); p = 0.454). Power Doppler sonography was more sensitive than color Doppler sonography in the detection of flow signals in hepatocellular carcinomas after administering Levovist (91% (20/22) vs. 50% (11/22); p = 0.008). Eighty percent (16/20) of hepatocellular carcinomas had signals of curvilinear type versus spotty type (p = 0.0005), the detected signal in both hemangiomas was iris diaphragm phenomenon. The typical spoke-wheel appearance of focal nodular hyperplasia was more easily demonstrated after administering Levovist. The hepatocellular carcinomas with absent baseline flow (1.2-5.6 cm, mean: 3.1 +/- 1.0 cm) tended to be smaller than the hepatocellular carcinomas with baseline flows (2.3-8.3 cm, mean: 4.9 +/- 2.2 cm) (p = 0.06). The 9 hepatocellular carcinomas (largest diameter: 1.2-3.8 cm, mean: 2.6 +/- 0.8 cm) with enhanced flows only observed by power Doppler sonography was smaller than the 11 hepatocellular carcinomas (largest diameter: 2.3-8.3 cm, mean: 4.5 +/- 1.8 cm) with enhanced flows observed by color Doppler sonography and power Doppler sonography (p = 0.01). CONCLUSIONS: Enhanced color flow study may aid in the detection of flow signals or sonographic differentiation of hepatic tumors.

Adult↗

PubMed2003

Color vision with rapid-onset acceleration.

INTRODUCTION: Only sporadic information exists concerning perceived color shifts at increased G-loads. The purpose of this study was to investigate whether or not color vision is affected by rapid onset high G7-loads up to +9 Gz, and specifically whether perception of hue changes. METHODS: There were 10 male subjects, 9 with normal color vision and 1 with red-green protanomaly, all accustomed to Gz-loads in a human centrifuge. Each subject was tested on a total of 60 Gz-exposures with 10 s periods at +3, +5, +7, and +9 Gz in the centrifuge on three different days. G-onset rate was 6 G x s(-1). The subjects wore an anti-G suit and performed straining maneuvers if necessary to maintain vision. Five square color stimuli of medium saturation (yellow, red, blue, green, and gray) were projected one at a time on a screen in front of the subject, who gave his hue response orally. RESULTS: In 96.6% of exposures to various Gz-loads, the subjects responded by correctly naming colors. (The statistical analyses of the results were done for the subjects with normal color vision, with the protanomalous subject excluded.) Hue shifts occurred at the higher +Gz-levels, including 7.7% of the +9 Gz exposures. Yellow was the hue most frequently perceived as changed. Hue shifts were reported for yellow in 11% and 16% of the +7 and +9 Gz exposures, respectively. Hue shifts at +9 Gz occurred as frequently as blackout and G-LOC together. However, statistical analyses showed no significant effects for +Gz-load. CONCLUSIONS: Absolute identification of the color stimuli of medium saturation was stable and was not significantly affected by the rapid onset +Gz-loads up to and including +9 Gz.

Acceleration↗

PubMedDate not supplied

Color vision testing.

1. Color deficiency occurs in about 8% of the population, due to alterations in the chemistry of one of the three receptive pigments for colored light, or the substitution of one pigment for another in the photoreceptor cones. 2. Subjects with pigment alteration can see a broad range of color; those with substitution of one pigment for another have broad areas of color perception defect. 3. The most common tests are pseudoisochromatic (color confusion) plates, designed with patterns hidden to the color deficient. Other tests use colored caps, tracing patterns, or an anomaloscope.

Color Vision Defects↗

PubMed2004

[Color Doppler sonography of focal abdominal lesions].

Color Doppler sonography (CDS--spectral, color and power), harmonic imaging techniques (THI, PHI), possibility of 3D analysis of picture, usage of contrast agents, have raised the values of ultrasound as a diagnostic method to a very high level. THI--non-linear gray scale modality, is based on the processing of higher reflected frequencies, that has improved a picture resolution, which is presented with less artifacts and limiting effects of obesity and gases. Ultrasound contrast agents improve analysis of micro and macro circulation of the examined area, and with the assessment of velocity of supply in ROI (wash in), distribution and time of signal weakening (wash out), are significantly increasing diagnostic value of ultrasound. Besides the anatomical and topographic presentation of examined region (color, power), Color Doppler sonography gives us haemodynamic-functional information on vascularisation of that region, as well as on pathologic vascularisation if present. Avascular aspect of a focal pathologic lesion corresponds to a cyst or haematoma, while coloration and positive spectral curve discover that anechogenic lesions actually represents aneurysms, pseudoaneurysms or AVF. In local inflammatory lesion, abscess in an acute phase, CDS shows first increased, and then decreased central perfusion, while in a chronic phase, a pericapsular vascularisation is present. Contribution of CDS in differentiation of hepatic tumors (hemangioma, HCC and metastasis) is very significant. Central color dots along the peripheral blood vessels and the blush phenomenon are characteristics of capillary hemangioma, peritumoral vascular ring "basket" of HCC, and "detour" sign of metastasis. The central artery, RI from 0.45 to 0.60 and radial spreading characterize FNH. Hepatic adenoma is characterized by an intratumoral vein, and rarely by a vascular hallo. Further on, blood velocity in tumor defined by Color Doppler, distinguishes malignant from benign lesion, where 40 cm/s is a rough border value. Values of DPI (Doppler perfusion index) over 0.3 and tumor index over 1.0 characterize primary, and lower values characterize secondary liver malignancies. In differentiation of benign and malign tumors of kidneys, besides the aspect of vascularisation, the maximal frequency altitude in tumor artery (the limit around 2.5 kHz) is very important. However, peripheral and penetrating blood vessels are most usually seen in RCC, less often in AML and bigger oncocytomas. CDS with contrast agent is very useful in making differential diagnosis of the focal lesions with 95% specificity for some lesions.

Abdomen↗

PubMed1992

Color changes of light-cured composite resins.

The color changes of light-cured composite resins over specified periods of time were examined. Silux Plus (3M Co.) light-cured composite resin disks (shades: U,Y,DY,L,G,UO,YO) 10 mm in diameter and 1 mm in thickness were made with 2 minutes of light exposure. Five specimens of each color were prepared. The specimens were stored in 37 degrees C artificial saliva. The colorimetric values of the specimens were measured first without a background color and then against a white plate immediately after curing and then 1 day, 1 month, 3 months, 6 months and 1 year later. The color measuring was performed with the Murakami Color Research Laboratory Fast Spectrophotometer CMS-500 and Flexible Sensor FS-3. For specimens without background color, the delta E*ab values of all shade guides increased for 6 months proportionately to the time elapsed. For specimens measured against a white plate, the delta E*ab values of all shade guides increased for 6 months after curing. However, compared to the 6 month delta E*ab values, the one year delta E*ab values increased in some shades and decreased in other shades. Using the values obtained immediately after curing as the standard, the delta E*ab of the month specimens with or with-out background color were over 1.2, meanwhile most one year specimens were near or over 2.5.

Color↗

PubMed1992

[Confusion lines in dichromatism using various surface colors].

Confusion lines, convergence points, and neutral points in dichromatism were examined using various surface colors. Confusion lines were obtained from 8 cases of protanopia and 24 cases of deuteranopia by color matching with the surface colors of the Farnsworth-Munsell 100 hue test, then regression analysis was carried out on the cross-points of all confusion lines obtained. Convergence points were obtained and neutral points were also calculated. The convergence point obtained from protanopia using surface colors converged to x = 0.811 and y = 0.189, which is a point near Pitt and Judd's convergence point. The confusion line gradient obtained from deuteranopia was steeper than that of Pitt and Judd's line. The convergence point of deuteranopia was x = 1.959 and y = -0.959. Compared with previous reports, it was in the lower right region. The neutral point of protanopia was in the vicinity of 495 nm and that of deuteranopia in the vicinity of 500 nm. These two values were almost the same as the values in Judd's report. Considering the results mentioned above, the neutral point obtained with surface colors was almost the same as that obtained with spectrum color. From the above results, the convergence point was thought to be different from that obtained using spectrum color. In particular, the difference was significant in deuteranopia.

Adolescent↗

PubMed1991

[Color adaptation in a yellow-blue system: proof of a simple numerical relationship].

Three axes in color space are specified: a (unique) yellow - (unique) blue axis, a (unique) green - magenta axis and brightness. Based on the two chromatic axes two linear opponent colors systems are defined: a red/green-system and a yellowish/bluish-system. A numerical relation is presented to describe color adaptation for the yellowish/bluish-system under adaptation to (unique) yellow and (unique) blue: two pairs of color stimuli are equivalent with regard to the yellowish/bluish-system - consisting of a test stimulus and an adaptation stimulus, respectively - if the ratios from the yellowish/bluish-coordinates of test stimulus and adaptation stimulus are identical. A control of brightness and the red/green-system is presupposed. For several (unique) yellow and (unique) blue adaptation stimuli it is examined how a test stimulus that appears neither yellowish nor bluish changes its location on the (unique) yellow - (unique) blue axis within color space. Three observers take part in the experiment. For each observer a plane of constant brightness and the opponent colors axes are estimated experimentally. The data show that the ratios from the yellowish/bluish coordinates of test stimulus and adaptation stimulus are essentially constant. The results are compared with analogous data for the red/green-system. The findings provide evidence for the specification of the three phenomenal axes. The specification is discussed with regard to Hering's opponent colors theory and Krauskopf's three "cardinal" axes [1982, Vision Research, 22, 1123-1131].

Adaptation, Ocular↗

PubMed1990

Children's sex-related stereotyping of colors.

4 studies addressed children's sex-related stereotyping of colors. Study 1 examined preschoolers' awareness of color stereotypes. Children were presented with 6 toy animals, identical except for color, and were asked to identify the sex of each animal and to select a favorite. Both sex identifications and toy preferences were highly consistent with adult color stereotypes. Study 2 demonstrated that clothing color influences preschool, kindergarten, and first-grade children's impressions of other children whose sex is known. Studies 3 and 4 indicated that the effects of stereotyping based on color are modest in comparison to the effects of stereotyping based directly on sex. In addition, color stereotyping did not show the regular age-related increase that is characteristic of sex-role stereotyping.

Child↗

PubMed1986

Categorical shape and color coding by pigeons.

Categorical coding is the tendency to respond similarly to discriminated stimuli. Past research indicates that pigeons can categorize colors according to at least three spectral regions. Two present experiments assessed the categorical coding of shapes and the existence of a higher order color category (all colors). Pigeons were trained on two independent tasks (matching-to-sample, and oddity-from-sample). One task involved red and a plus sign, the other a circle and green. On test trials one of the two comparison stimuli from one task was replaced by one of the stimuli from the other task. Differential performance based on which of the two stimuli from the other task was introduced suggested categorical coding rules. In Experiment 1 evidence for the categorical coding of sample shapes was found. Categorical color coding was also found; however, it was the comparison stimuli rather than the samples that were categorically coded. Experiment 2 replicated the categorical shape sample effect and ruled out the possibility that the particular colors used were responsible for the categorical coding of comparison stimuli. Overall, the results indicate that pigeons can develop categorical rules involving shapes and colors and that the color categories can be hierarchical.

Animals↗