Color Matching Research Articles

Comparative Color Stability Assessment of One- Shaded Structurally-Colored and Conventional Multi-Shaded Resin Composites

Purpose: To assess the color stability of one- shaded structurally- colored resin composite compared to conventional multi- shaded one. Subjects and methods: Thirty- two disc- like specimens from one- shaded structurally- colored resin composite (Omnichroma, Tokuyama Dental); Group I, or conventional resin composite (Filtek Z350, 3M ESPE); Group II were prepared, with equal allocation ratio (i.e.: n= 16). Samples were left in coffee then by using spectrophotometry, colors for all specimens were assessed in (CIE) Lab values; before (baseline) and 30 days later. Substitution in the (after - before) equation was performed to obtain the color change (ΔE); to detect color change for each specimen. Data was tabulated & statistically analyzed. Results: One- shaded structurally- colored resin composite (Omnichroma) showed statistically significant (p ≤ 0.05) color stability in comparison to conventional resin composite (Filtek Z350). Conclusion: One- shaded structurally- colored resin composite (Omnichroma) proved better than conventional resin composite (Filtek Z350) regarding color stability. Esthetic color matching, therefore, could be easily obtained and maintained.

Construction of grid color mixture model of seven primary-color and modified Stearns-Noechel color matching algorithm for color prediction of full-color-gamut rotor melange yarn

In this paper, the full-color-gamut grid color mixture model containing 601 grid points is constructed by ternary double coupling blending of seven primary-color fibers, and the spinning method of full-color-gamut melange yarn is given by combining with three-channel NC rotor spinning technology. A modified S-N color prediction model was constructed by selecting 55 uniformly distributed grid points for yarn and fabric production from the full-color-gamut grid color mixture model as samples for solving the reflectance conversion coefficients. On this basis, the method of predicting the color value of a melange yarn based on its primary-color fiber composition and blending ratio and predicting the primary-color fiber composition and blending ratio based on the color value of a melange yarn using the parameters of the nearest sample grid point is proposed, and six samples with different blending ratios in six color mixing regions of the full-color-gamut grid color mixture model are designed for validation. The results showed that the average color difference between the predicted color and the actual color of the melange yarn is 1.15, the predicted primary-color fiber composition of the melange yarn is consistent with the actual composition, and the average error between the predicted blending ratio and the actual blending ratio is 3.95%. The method proposed in this paper can effectively predict the color value and blending ratio of melange yarn.

Performance of CIE 2006 Color Matching Functions in Different Fields of View

Performance of CIE 2006 Color Matching Functions in Different Fields of View

A Comparative Study between Autologous Noncultured Trypsinized Melanocytes-Keratinocytes Cell Suspension and Autologous Noncultured Nontrypsinized Epidermal Cells Grafting (Jodhpur Technique) in Stable Vitiligo.

Noncultured epidermal cell suspension (NCES) and Jodhpur technique (JT) are two treatment options in vitiligo, in which the basic principle is the transfer of melanocytes from uninvolved skin to stable vitiligo patch in the form of either tissue graft or cellular graft. The aim of this study was to evaluate effectiveness of two different treatment methods (NCES and JT) in stable vitiligo. This was a randomized comparative study, which included 45 patients with 153 stable vitiligo patches. Cases were randomly divided into two groups. Appropriate statistical analysis was done. A value of P < 0.05 was considered statistically significant. Of 45 cases, female-to-male ratio was 1.36:1. Mean duration of disease and stability were found to be 10.44 ± 5.24 and 3.83 ± 2.31 years, respectively. Mean size of treated area for NCES and JT was 10.11 ± 10.31 and 10.13 ± 10.29 cm2, respectively. Earliest repigmentation was found at 3 weeks in NCES and 6 weeks in JT. At 6 weeks, repigmentation was better in NCES, whereas later JT showed better pigmentation. Follow-up was done at 8 days and 6, 10, 14, and 24 weeks. With respect to color match at 6 weeks, JT was found superior; however, at 24 weeks both showed similar efficacy. Mean reduction in daily life quality index was significantly decreased post-surgery. This was a single-center, small sample size study. Melanocyte plus keratinocyte cell transfer is very effective in the treatment of stable vitiligo. On the basis of the results, JT may show significant contribution in vitiligo.

Color matching method of product interactive interface based on user experience

Color matching method of product interactive interface based on user experience

The Longevity and Clinical Performance of Direct and Indirect Restorations, Including Amalgam, Composite, Ceramic, and Metal Restorations

The longevity of dental restorations depends on patient-related, dentist-related, and material-related factors. Patientrelated factors include restoration size, chewing habits, oral hygiene, and systemic conditions. Strength, wear resistance, water tolerance, dimensional stability, and colour stability are all material-related variables. When deciding on a course of treatment, dentists must take these things into account. Since the 19th century, dental amalgam, which is composed of mercury, silver, tin, copper, and other metals, has been used effectively. Although it has limits in terms of tooth colour matching, it is appropriate for Class I and II restorations. Amalgam offers good load-bearing qualities, wear resistance, and tolerance for various clinical conditions. Safety concerns include the release of mercury vapor and the possibility of localized allergic reactions. Resin-based composites are esthetic and safe materials used for anterior and small to moderate-sized posterior fillings. Postoperative tooth sensitivity and shrinkage-related issues can occur, but improvements have minimized these problems. Adequate field control is essential for successful placement. Indirect restorative materials include all-ceramic and base metal casting alloys. All-ceramic restorations provide excellent aesthetics, high strength, and biocompatibility. However, they rely on resin-based cements and adhesives for retention, and allergies can occur. Base metal alloys offer an economical alternative and are effective for crown-and-bridge restorations. The choice of restorative materials depends on various factors, and dentists must consider the specific needs of each patient to achieve successful outcomes.

Arbitrary Style Transfer With Fused Convolutional Block Attention Modules

The advancement of deep learning has rendered image style transfer a progressively intricate subject matter. The proposed solution aims to tackle the limitations of current methods in retaining the content image object contours and avoiding blurred image boundaries and mismatched color matching after stylization. To achieve this, an arbitrary-style transfer network is introduced, which leverages the attention mechanism. The network comprises an encoder-decoder module, a convolutional block attention module (CBAM), and an adaptive attention normalization network (AdaAttN) module. The CBAM attention mechanism is presented as an extension of the AdaAttN network, with the aim of producing stylized images that exhibit both global and local style coordination. This is achieved by leveraging long-range dependencies in the image. Additionally, a novel loss function, referred to as the structural similarity loss, is proposed to enhance the consistency of the generated images with respect to the underlying content structure. Finally, a new local feature loss is introduced to further enhance the visual quality of the stylized images at a local level. The study involved conducting style transfer training on a dataset comprising 82,783 real images and 81,446 artistic images. Furthermore, an additional set of 1,000 resultant images, generated from 100 real photos and 10 artistic portraits, was utilized for testing purposes. The study compares the experimental outcomes with four contemporary-style transfer techniques. Additionally, the efficacy of the CBAM module and SSIM loss function is demonstrated through ablation experiments. The findings of the experiment demonstrate that the network proposed has the ability to effectively adapt to the local style and can adeptly correspond the semantically proximate style features to the content features, thereby preserving superior spatial consistency.

Development of an Electric Pegboard (e-Peg) for Hand Dexterity Improvement and Cognitive Rehabilitation: A Preliminary Study

Fine motor dysfunction and cognitive impairments commonly develop after stroke, which greatly impact the daily lives of patients. In current occupational therapy, hand dexterity and cognitive functions are evaluated individually (e.g., by manipulation of small objects with fingers, or a paper-and-pencil test), which is insufficient for therapists to grasp the total ability of combined dexterity and cognition in everyday situations. Additionally, the traditional methods require a tester to measure the completion time manually and tend to be monotonous for patients. These problems would be solved using technology. This study aimed to develop a new electric pegboard (e-Peg) prototype and to investigate preliminary utility in healthy adults. The system judges the peg insertion accuracy based on magnetism and records the time course and scores, which are linked to human object manipulation ability. The e-Peg executes three types of tasks: a basic color matching task (BT), a color comparison task using a pattern sheet (CT), and a visual memory task (MT), with one/two-color sample patterns. Six older and nine younger healthy adults performed the e-Peg tasks, functional tests, and responded to questionnaires. As a result, the number of correct answers in a bicolor symmetrical MT were significantly greater in the younger group than in the older group. The older group required a significantly longer completion time for BT and CT than the younger group. Significant correlations were found between one-color BT/CT and dexterity tests, between bicolor BT/CT and dexterity/cognitive tests, and between a bicolor MT and a cognitive test. Questionnaire results revealed that participants regarded BT/CT as easy/interesting tasks, whereas MT was considered a difficult/challenging task. In conclusion, our e-Peg is potentially a useful rehabilitation device that facilitates many tasks related to hand manipulation and attention/executive functions, and a valuable tool for personalized therapy.

The effect of thickness and cement shade on the color match of different CAD-CAM glass-ceramic materials

Aim: This study aimed to assess the impact of the type and thickness of the ceramic and cement color on the targeted shade of glass-ceramics with various chemical compositions. Methodology: Thirty ceramic specimens were prepared from leucite-reinforced (GC Initial LRF, GC Group) and lithium-disilicate (IPS e.max CAD, EM Group) materials in three different thicknesses (0.5 mm, 0.7 mm, and 1 mm). Four 4-mm-thick substrates were then made from A3-shaded composite resin material to mimic tooth structure and be utilized for cement application. Four shades (Variolink II: transparent, white, yellow, and bleach) of 0.2-mm-thick resin cement were polymerized over these substrates. Next, the specimens were placed over these substrates, and color measurements were applied with a spectrophotometer (VITA Easyshade V) leading to 24 group combinations (n=5). The color difference (∆E) readings were obtained in the spectrophotometer's reference shade verification mode by selecting the A2 shade standard. Three-way mixed ANOVA, Tukey HSD, and Bonferroni tests were used for statistical analysis (α=0.05). Results: The main effects of material, cement, and thickness were found to be statistically significant (p &lt; 0.05), as were the interactions of cement×material, cement×thickness, and material×thickness (p &lt; 0.05). However, the material×cement×thickness interaction was not found to be statistically significant (p = 0.568). Regardless of thickness or cement shade, the GC group had a lower mean ∆E value than that of the EM group (p &lt; 0.05). Lower ∆E values were achieved in both materials with a thickness of 1 mm and bleach-shaded cement (p &lt; 0.05). The materials with the greatest mean ∆E values were those with the thickness of 0.5 mm and the transparent shade cement combination (p &lt; 0.05). Conclusion: The thickness and shade of the cement used influenced the final color of the glass-ceramic materials with the same shade and translucency but diverse chemical compositions. When compared to the lithium disilicate glass-ceramic material, the leucite-reinforced feldspathic glass-ceramic material displayed lower color difference values and a better color match with the targeted shade. How to cite this article: Yılmaz Savaş T. The effect of thickness and cement shade on the color match of different CAD-CAM glass-ceramic materials. Int Dent Res 2022;12(Suppl.1):108-13. https://doi.org/10.5577/intdentres.457 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

The effects of age on tooth color and of viewing distance on visual tooth color matching in aesthetic dentistry

Aim: This study aims to question the effect of visual distance on color selection by scoring the maxillary central tooth color with the visual color selection method and to investigate the relationship between tooth color and patient age. Methodology: Maxillary central tooth color was determined by a single operator using visual methods from two different distances, 35 cm and 70 cm, in a total of 100 people between the ages of 20-80 and of different genders. The value, hue and ages of the teeth were recorded using the VITA Toothguide 3D-MASTER color scale at 2 different viewing distances. Visual color selection was made in natural daylight, preferably between 10:00 and 12:00 in the morning. Subjects were observed at eye level, and all color assessments were performed rapidly (5-7 s). Independent T-test was used for independent groups and Chi-square test was used for dependent groups. Results: Considering the relationship of lightness with distance, there is a significant difference between the values ​​at 35 cm and 70 cm distances. It was observed that the lightness increased when the measurements made from 70 cm were compared with the measurements made from 35 cm. As the age increases, the ratio of the brightness value of 1, which is the highest lightness, decreases, and the ratio of the darker 3 and 4 lightness​​increases. R (reddish) hue was found to be higher in the 40-59 and over 60 age groups compared to the 20-39 age group. Conclusion: It was observed that the tooth color was determined lighter in the measurements made from 70 cm compared to the measurements made from 35 cm. It is important to determine the color at 35 cm so that the incorrect lightness (value) is not selected. It can be said that as the age increases, the tooth gets darker and the reddish and yellowish hue increases. How to cite this article: Kızılırmak B, Güntekin N, Tunçdemir AR. The effects of age on tooth color and of viewing distance on visual tooth color matching in aesthetic dentistry. Int Dent Res 2022;12(Suppl.1):29-33. https://doi.org/10.5577/intdentres.442 Linguistic Revision: The English in this manuscript has been checked by at least two professional editors, both native speakers of English.

Translucent Monolithic, Multi-Layered Zirconia: Matching Esthetics with Strength

High esthetic demand of patients has led to the development of newer tooth-colored restorative materials. Yttria-stabilized Zirconia (3Y-TZP) ceramic is considered an acceptable material for prosthetic rehabilitation due to its high fracture resistance, biocompatibility, biomechanical stability, and better color matching compared to the traditional porcelain fused to metal restorations. Tetragonal stabilized polycrystalline zirconia (TZP: tetragonal zirconia polycrystal) is doped with 3 mol% yttrium oxide (3Y-TZP).The opaque appearance of zirconia is a key challenge in obtaining optimum esthetics. These restorations are typically veneered with a weak glassy phase ceramic to mask the opaque appearance. The risk of delamination and chipping of ceramic veneer from such layered prostheses is a major concern. High masticatory load in posterior teeth, poor framework design, inadequate thickness of ceramic veneer, contamination of zirconia substructure, low elastic modulus and thermal conductive of zirconia compared to veneer porcelain could be some of the factors leading to such catastrophic failures.Various methods have been developed to increase the translucency of zirconia such as increasing the percentage of the cubic phase, increasing sintering temperature, reducing impurities, altering yttria content, and reducing the grain size. With higher yttrium doping, the proportion of cubic phase zirconia is increased by 25 % for 4Y-TZP and 53 % for 5Y-TZP, which allows for improved translucency. However, with the increase in the cubic phase proportion, there is a risk of reduced strength, due to a reduction in the extent of transformation toughening.More recently, new monolithic multi-layer zirconia has been developed with a color gradient from the incisal to the cervical third, miming natural tooth color. Different grades of the translucent blank are available such as High Translucent Multi-layered (HTML), Super Translucent Multi-layered (STML), and Ultra Translucent Multi-layer zirconia (UHTML). Multi-layer zirconia discs consist of different layers with varying degrees of transparency: the outer enamel layer, transitions layers, and an inner body layer. This new innovative multilayer polychromatic zirconia blank allows technicians to work with a nearly universal zirconia blank. However, more researches ensuring the optimum mechanical properties of newer products are necessary before they can be safely used in all clinical scenarios.

Comparison between color stability of zirconia and lithium disilicate

The most widely used glass-ceramic is lithium disilicate (LD) because of its remarkable optical qualities, high strength, and simplicity of manufacture. Greater marginal strength, reduced porosity, and net-shaped manufacturing by pressing are further benefits of LD. The development of yttrium stabilized trigonal zirconia polycrystalline (Y-TZP) ceramics is the result of the pursuit for a material with both mechanical capabilities, like the resistance provided by metallic restoration, and the distinctive optical characteristics of glass-ceramic. The main drawback is the fragile veneering ceramics, which are prone to chipping, debonding, and breakage. There is evidence that extrinsic variables such beverages, mouthwashes, acid solutions, dental brushing, and increased temperatures might cause ceramic surfaces to deteriorate. The composition and surface shape of ceramic materials have an impact on the extrinsic pigment absorption or adsorption from the oral cavity. The main causes for the clinical replacement of anterior restorations, according to prior research, are poor color matching and color instabilities. Monolithic zirconia is more prone to staining from chlorhexidine, green tea, and coffee. In monolithic zirconia, the aging-related color changes are more pronounced. The color of the background substructure influences how zirconia restorations look overall. In terms of color stability and translucency, LD ceramic has also been proven to be more aesthetically pleasing. In comparison to monolithic zirconia, bilayer zirconia with feldspar veneering ceramic displayed reduced discoloration overall. It has been noted that monolithic zirconia is more susceptible to low-temperature degradation than the core Y-TZP. The use of current literature to infer outcomes has several limitations because in most vitro investigations, thermocycling has been carried out in water rather than oral cavity saliva and the influence of sunlight exposure, salivary proteins, food coloring, tobacco, different enzymes, and surface-related factors on the color stability is yet to be examined.

Newly learned shape-color associations show signatures of reliability-weighted averaging without forced fusion or a memory color effect.

Reliability-weighted averaging of multiple perceptual estimates (or cues) can improve precision. Research suggests that newly learned statistical associations can be rapidly integrated in this way for efficient decision-making. Yet, it remains unclear if the integration of newly learned statistics into decision-making can directly influence perception, rather than taking place only at the decision stage. In two experiments, we implicitly taught observers novel associations between shape and color. Observers made color matches by adjusting the color of an oval to match a simultaneously presented reference. As the color of the oval changed across trials, so did its shape according to a novel mapping of axis ratio to color. Observers showed signatures of reliability-weighted averaging-a precision improvement in both experiments and reweighting of the newly learned shape cue with changes in uncertainty in Experiment 2. To ask whether this was accompanied by perceptual effects, Experiment 1 tested for forced fusion by measuring color discrimination thresholds with and without incongruent novel cues. Experiment 2 tested for a memory color effect, observers adjusting the color of ovals with different axis ratios until they appeared gray. There was no evidence for forced fusion and the opposite of a memory color effect. Overall, our results suggest that the ability to quickly learn novel cues and integrate them with familiar cues is not immediately (within the short duration of our experiments and in the domain of color and shape) accompanied by common perceptual effects.

Determination, implication, and satisfaction of shade selection in aesthetic dentistry

Delivering an aesthetic solution that proportionally complements the patient's neighboring teeth is crucial. In the discipline of cosmetic dentistry, qualities like surface form, translucency, and color are the most important factors for creating esthetic prostheses. The final color of translucent ceramic restorations is determined by many factors such as the thickness of the porcelain veneer, the thickness and color of the luting agents and the color of the underlying tooth structure. In order to the results to be accurate, homogenous, and predictable—all of which are crucial for cosmetic dentistry—color matching must be carried out in a methodical manner. Lighting control at the site, the surrounding environment, state of the teeth, patient positioning, time, and clinician proximity to the tooth, squint test, visual color guidelines, Vita Classical shade guide, Vita Toothguide 3D-Master, Chromascop, customized shade guides, and dentinal and extended shade guides are all considered when mapping shade and translucency. A sensor, a signals conditioner, and technology that allows the conversion of the signals into data usable in the dental laboratory or operatory make up the three components of every color-measuring instrument. Colorimetry, spectrophotometry, digital photography, hybrid equipment, and spectroradiometry comprise a few types of color measurement technology. Both print and electronic shade systems need to be used when choosing the right shade in order to create acceptable aesthetics. The practitioner and patient are both satisfied when the appropriate shade is matched, and the patient also has a more appealing appearance.

An investigation on fatigue, fracture resistance, and color properties of aesthetic CAD/CAM monolithic ceramics

ObjectivesTo evaluate and compare fracture resistance, translucency, and color reproducibility, as well as the effect of aging on the fracture load and color stability of novel monolithic CAD/CAM ceramics.Materials and methodsOne hundred crowns of uniform thickness were milled from five ceramic blocks (n = 20): partially crystallized lithium disilicate (PLD) and fully crystallized lithium disilicate (FLD), lithium metasilicate (LMS), 4Y-TZP (SMZ), and 5Y-TZP (UMZ) monolithic zirconia. PLD crowns were glazed, LMS was fired, and FLD was polished. SMZ and UMZ crowns were sintered and polished. Crowns were adhesively cemented to epoxy dies. Half of the crowns (n = 10) were subjected to 1.200.000 load cycles with thermal cycling. Color space values L, a, b defined by the Commission Internationale de l´Eclairage (CIELAB) were measured before and after aging, and (∆E) was calculated. Both aged and non-aged specimens were loaded until fracture in a universal testing machine and the fracture load was recorded. X-ray diffraction (XRD) and scanning electron microscope (SEM) fractographic analysis were carried out on fractured fragments of representative samples. For translucency and color reproducibility, 50 rectangular-shaped specimens were fabricated and processed as described previously. Color values were measured over black and white backgrounds, and the translucency parameter (TP) was computed. Using the shade verification mode, (∆E) to shade A3 was calculated. Data were statistically analyzed using one-way and two-way ANOVA, and t-test.ResultsAging did not affect fracture resistance significantly (p > 0.05). The highest mean fracture load was obtained for the SMZ and UMZ. A significant color change was observed after aging in all groups. The highest TP was noted for FLD. SMZ and UMZ had the best shade match.ConclusionsZirconia showed higher fracture resistance and color stability than lithium silicate ceramics. Lithium silicate ceramics were more translucent. The experimental FLD demonstrated high translucency.Clinical relevanceTested ceramics showed sufficient stability to withstand masticatory forces. Characterization of final restorations might be mandatory for better color match.

Lantana camara flowers as a natural dye source for cotton fabrics

ABSTRACT Environmental concerns about synthetic dyes and their carcinogenic properties renewed interest in eco-friendly natural dyes. Natural dyes produce a wide range of tints and shades with the same dye material. In this study, natural colorants from Lantana camara flowers, a Verbenaceae plant, have been applied to bleached cotton fabrics following pre-mordanting, simultaneous mordanting, and post-mordanting with different chemical mordants (copper sulfate, ferrous sulfate, nickel sulfate, potassium aluminum sulfate, potassium dichromate, stannous chloride). Dyed samples were tested for wash-fastness, light-fastness, and rubbing-fastness, as per Standard IS methods. The colors of dyed pieces were evaluated with color matching software using CIELAB (ΔL*, Δa*, Δb*) coordinates and K/S values for dye absorption on cotton. Pre-mordanting produced good dye uptake. The extracted natural dye was analyzed using Ultraviolet-Visible Spectroscopy, Fourier-Transform Infrared Spectroscopy, and Inductively Coupled Plasma Mass Spectrometry. This study demonstrated that the flowers of Lantana camara are an excellent source of eco-friendly natural dye, and the dye extract is free from heavy metals such as antimony, arsenic, cadmium, and lead. Cotton and natural fiber textiles can be commercially dyed with the dye extracted from the Lantana camara flowers using a variety of chemical mordants to achieve different color shades.

Ecofriendly pretreatment of cotton fabrics by ultrasonication and reusing bath chemicals.

The textile industries of Bangladesh contribute significantly to the country's economy, accounting for more than 40% of total annual export. The quest of new technologies for efficient water and energy use in cotton knit dyeing could result in significant water savings and improve environmental sustainability. Textile wet processing consumes a lot of utilities (water and energy), and the water generates a lot of waste, which enhances chemical consumption and effluent management costs. The cotton knit fabric used in this study was pretreated and dyed utilizing ultrasonication at a lower temperature than conventional pretreatment and dyeing techniques in an attempt to establish ecofriendly wet processing in the textile industry. The bath chemicals were reused up to two times before dyeing in conventional techniques, and fabric properties such as whiteness index, weight loss, bursting strength, color fastness to light, washing, perspiration, rubbing, color strength and durability, or dimensional stability were evaluated and compared with the values obtained by conventional techniques. The color matching of reactive dyed fabric for ultrasonic pretreated fabric with and without reusing bath chemicals was determined. The sonicated scoured and bleached fabric's whiteness index was found to be acceptable, with relatively low weight loss; however, the bursting strength was found to be increased. Color fastness to light, washing, perspiration, and rubbing were found to be comparable to the conventional technique for low temperature ultrasonicated pretreated and reuse-1 pretreated dyed knit fabric. The results also revealed that there was no color degradation during ultrasonication. FT-IR spectroscopy and scanning electron microscopy (SEM) revealed no significant changes in the chemical composition of cellulose or the fabric shape of pretreated and dyed cotton knit fabric after ultrasonication.

On the twilight phenomenon of the green band.

The twilight sky is usually characterized by the well-known reddish/orange colors close to the horizon and the blue colors above. However, in many cases, a green or greenish band forms between the blue and reddish parts of the sky, and it is essentially not documented in the literature. In this study, the green band phenomenon is simulated using the radiative transfer model SCIATRAN and subsequent color modeling based on the CIE color matching functions and chromaticity values. Different parameters and processes that have a potential influence are investigated. In addition, a possible contribution by airglow emissions is discussed. The simulations show that it requires just the right intensities in the blue, green, and long-wave spectral regions to produce a green color. The total ozone column has the comparatively largest influence. This study is, to the best of our knowledge, the first detailed investigation of the green band phenomenon.

Black-to-Transmissive dual polymer complementary electrochromics with high coloration efficiency

In a complementary electrochromic device (ECD), both the anode and the cathode can synergistically change color in response to an electrical bias, allowing for a high coloration efficiency. Complementary ECD that can switch from black to transmissive state is rare, due to the difficulty of pairing two electrochromic electrodes. In this study, we report the construction of high coloration efficiency complementary ECDs by pairing polyazoisoindigo (PAI), an n-type electrochromic polymer that undergoes green-to-transmissive switching, with p-type magenta (ECP-M) and red (ECP-R) electrochromic polymers to obtain black-to-transmissive ECD. Physical modeling tool, COMSOL, is introduced for complementary color matching. Through balancing the charge densities of two electrochromic electrodes, black-to-transmissive ECDs with record-high coloration efficiencies of 688 cm2/C and 437 cm2/C have been achieved for PAI|ECP-M and PAI|ECP-R, respectively. This study provides a general protocol for the design and fabrication of complementary ECDs.

The V Advancement Flap Sans Y Closure in Treatment of Volar Foot Ulcers

Background: Management of foot ulcer is challenging for plastic surgeons owing to inherent sturdiness of the volar skin and also the necessity to give a robust cover to ensure functionality including weight bearing. This study was conducted to examine the results of our technique of single or double ‘V’ advancement flap sans the ‘Y’ closure of the classical ‘VY’ flap, which was found to be technically simple for the management of plantar ulcers in our foot ulcer patients. Methods and Material: 37 patients hospitalized for the management of foot plantar ulcer, who underwent repair with our modified ‘V’ flap advancement without ‘Y’ closure technique, at our institution were included in the study. Demographic data, disease-related parameters, technique related complications data were recorded and analysed. Technique complications or sequelae, if any, were accounted. Descriptive statistics was used to summarize the findings. Results: In our study, 23 men and 14 women were there with their ages ranging from 15 to 87 years (mean = 54.1 years). The diameter of the ulcers ranged from 14 to 26 mm with mean of 19.3 mm. Unilateral V (-Y) advancement flap was used in 26 cases and in 11 cases bilateral V (-Y) advancement flap was used. Complications included wound dehiscence (3) and partial flap loss (1) of which 3 required redo surgeries while one healed with secondary intention. Conclusions: Though a relatively small study group our technique well suited the needs for plantar ulcer wound closure with acceptable complication rate. Key Messages: Foot ulcer management is a therapeutic challenge which, if managed efficiently reduces encumbrance. Our technique represents a useful and reliable technique with advantages of excellent colour and texture matching and primary donor site closure. Keywords: VY advancement flap, Plantar foot ulcer, Diabetic ulcer, Malignant foot ulcer, Trophic ulcer, Traumatic ulcer