Colored
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Polypropylene (PP) belongs among the most important commodity plastics due to its widespread application. The color of the PP products can be achieved by the addition of pigments, which can dramatically affect its material characteristics. To maintain product consistency (dimensional, mechanical, and optical), knowledge of these implications is of great importance. This study investigates the effect of transparent/opaque green masterbatches (MBs) and their concentration on the physico-mechanical and optical properties of PP produced by injection molding. The results showed that selected pigments had different nucleating abilities, affecting the dimensional stability and crystallinity of the product. The rheological properties of pigmented PP melts were affected as well. Mechanical testing showed that the presence of both pigments increased the tensile strength and Young's modulus, while the elongation at break was significantly increased only for the opaque MB. The impact toughness of colored PP with both MBs remained similar to that of neat PP. The optical properties were well controlled by the dosing of MBs, and were further related to the RAL color standards, as demonstrated by CIE color space analysis. Finally, the selection of appropriate pigments for PP should be considered, especially in areas where dimensional and color stability, as well as product safety, are highly important.
- MeSH
- houby MeSH
- modul pružnosti MeSH
- plastické hmoty * MeSH
- polypropyleny * MeSH
- pomocné látky MeSH
- Publikační typ
- časopisecké články MeSH
The diversity in human diets that can be reached by proper use of different crops and varieties, including some underutilized ones, is a potentially powerful strategy to ensure food security and prevent serious health problems caused by current diets that are often not fulfilling nutritional requirements. In the framework of this research, the content of tocopherols and tocotrienols, thiamine, riboflavin, pyridoxine, and superoxide dismutase in nine varieties of quinoa, both colored and nonpigmented, obtained from 4 different countries, was investigated and compared to the content of the same vitamins and antioxidants in barley and wheat, both colored and nonpigmented, cultivated in the same experimental field. The aim of this work was to create a crop diversity strategy and encourage the consumption of underutilized crops to ensure that the human diet fulfills nutritional requirements. The contents of vitamin B1, B2, B6, tocopherol, and tocotrienol isomers and superoxide dismutase were determined via HPLC; imaging techniques were used to evaluate the seed color. Quinoa grains had the greatest concentration of tocopherol isomers and activity, represented mainly by α-tocopherol and γ-tocopherol. Wheat and barley seeds had substantial concentrations of tocopherols and tocotrienols. The concentration of riboflavin was greater in barley and wheat than in quinoa, the concentrations of pyridoxine and thiamine were variety-dependent in all grains. Quinoa grains had greater concentration of superoxide dismutase compared to wheat and barley. The richness of each variety and crop should be recognized and used integrally to improve the diet quality. PRACTICAL APPLICATION: Nutritional potential of crops was evaluated from the viewpoint of selected vitamins and antioxidants to create a well-balanced diet. Combined use of both traditional (wheat, barley) and underutilized crops (quinoa) is recommended. HPLC methods and image analysis were successfully used as viable tools for food quality determination.
- MeSH
- alfa-tokoferol analýza MeSH
- antioxidancia analýza MeSH
- Chenopodium quinoa chemie MeSH
- ječmen (rod) chemie MeSH
- lidé MeSH
- nutriční hodnota MeSH
- pšenice chemie MeSH
- semena rostlinná chemie MeSH
- thiamin analýza MeSH
- tokoferoly analýza MeSH
- tokotrienoly analýza MeSH
- vitamin A analýza MeSH
- vitamin E analýza MeSH
- vitaminy analýza MeSH
- zemědělské plodiny MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Production of carotenoids with red yeasts is a promising area of industrial biotechnology. All spectrophotometrical ("classic") analyses of carotenoids are based on preliminary extraction of the water-insoluble carotenoids; thus, these analyses are precise but complicated and time consuming. This paper presents a simple method to evaluate the red-colored carotenoids in yeast biomass by its color, without extraction. The method is based on digital characteristics of the biomass whole coloring, and it has already been successfully applied in other areas of biology: to compare plant and animal objects. In contrast to spectrophotometry measuring the amount of light that can pass through a solution, the biomass photo is a reflected color of the insoluble compounds. Application of this method to microorganisms permitted to compare the yeast strains and the effects of substrates or culturing regimes for any change in the red-colored pigments. The proposed rapid method was compared with the classic analyses of the carotenoids and showed that evaluation of red-colored carotenoids by the whole coloring of biomass can be used to discover changes in the yeast carotenoid production. In whole, the paper contributes method which is new for pigmented microorganisms and has a potential application in biotechnology.
- MeSH
- biomasa * MeSH
- biotechnologie trendy MeSH
- fotografování MeSH
- karotenoidy * analýza chemie MeSH
- kvasinky * chemie MeSH
- spektrofotometrie MeSH
- Publikační typ
- časopisecké články MeSH
Restoration of decayed primary teeth is very important and significant not only for the maintenance of health and psychics of the child but also for the physiological development of permanent dentition. Esthetic materials were formulated for permanent teeth restoration, but they can also be used for the treatment of primary dentition, especially in minimally invasive techniques, atraumatic tooth restoration, and preventive interventions. Composite resins, glass ionomers, resin modified glass ionomers, and compomers are the materials of choice in the form of direct filling. Findings of individual authors on success of esthetic primary teeth restoration are, however, different and further well-founded clinical trials and experimental studies are necessary. Opinions on the decision-making process when choosing a restorative material are very similar and can be formulated in the following way: To receive reliable results with esthetic material restoration in primary dentition three conditions have to be present: isolation, cooperation, and time. Microscopic structure peculiarities of primary enamel and dentin and time until tooth exfoliation have to be taken into consideration too. One has to state, however, that the longevity of tooth-colored materials has not been found higher than that of amalgam. That is why dentists should consider the diagnosis, ease of material placement, oral hygiene, caries risk, esthetic demands, and financial aspects when choosing a restorative material for primary teeth.
- MeSH
- akrylové pryskyřice terapeutické užití MeSH
- dentinová adheziva terapeutické užití MeSH
- dítě MeSH
- estetika stomatologická MeSH
- financování organizované MeSH
- kompomery terapeutické užití MeSH
- lidé MeSH
- skloionomerní cementy terapeutické užití MeSH
- trvalá sanace zubů metody MeSH
- zuby mléčné MeSH
- Check Tag
- dítě MeSH
- lidé MeSH
- Publikační typ
- přehledy MeSH
OBJECTIVES: To evaluate systematically the influence of sex of dental professionals on their capability for visual color matching. MATERIALS AND METHODS: The protocol was registered on PROSPERO (CRD42020205393). PICOS question was develop based on the population, intervention, comparison, outcomes, and study design (PICOS). Eligibility criteria included cross section studies, randomized clinical trials and cohort studies that compared the effect of sex on the visual color matching process. Five electronic databases (Pubmed, Cochrane, EMBASE, Medline, and SCOPUS) and additional literature were screened independently by two researchers in July 2020. Clinical studies evaluating visual color matching skills of dental professionals were included. Studies that did not compare the difference between sexes were excluded. Duplicate articles were removed, titles and abstracts were screened, and studies were selected according to the inclusion criteria. Data were collected and reported in accordance with PRISMA guidelines. Risk of bias was assessed using Joanna Briggs Institute Critical Appraisal Tools. RESULTS: A total of 1192 articles were screened from which 132 full text articles were analyzed and 37 finally included in the systematic review. Most of the studies evaluated the color matching abilities of dental students in vitro with shade tabs or extracted teeth. Out of the 37 articles included, 25 reported no significant difference in shade matching abilities between the sexes. Of the 12 studies that found a significant difference, 11 reported that females had better scores in shade matching exercises. For all studies a low risk of bias was revealed for most of the domains. CONCLUSIONS: While the non-homogeneity of the settings and methods in the included studies make it impossible to construct aggregate statistic, this systematic review suggests that the sex is unlikely to be a critical factor influencing color matching abilities. CLINICAL SIGNIFICANCE: This study suggest that sex of dental professionals does not play a critical factor in matching satisfactory color of future dental restoration with surrounding teeth.
- MeSH
- barva MeSH
- barvení protéz * MeSH
- lidé MeSH
- návrh zubní protézy MeSH
- vnímání barev MeSH
- zuby * MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
- systematický přehled MeSH
Synestezie je pojem označující skutečnost, že podnět z jedné smyslové nebo kognitivní oblasti vyvolá vjem v jiné smyslové oblasti, která není primárně aktivována. Nejčastější synestezie jsou mezi grafémy a barvami, kdy písmeno nebo číslice napsané achromatickou barvou vyvolá barevný vjem. Tyto vjemy jsou vesměs pociťovány stejně reálně jako non-synestetiky skutečně vnímané barvy. Barevný vjem může evokovat i samotná představa grafému. Mezi synestezií a kreativitou jsou úzké vztahy dané tím, že synestetici jsou schopni vytvářet smysluplné asociace mezi rozdílnými stimuly. Autor předkládá souborný článek shrnující současné poznatky v této oblasti doplněný autentickými výroky synestetiků.
Synaesthesia is an experience in which stimulation in one sensory or cognitive stream leads to associated experiences in a second unstimulated stream. People with color-graphemic synaesthesia experience vivid, reliable color upon viewing achromatic alphanumeric characters. Recent evidence indicates that synaesthetic color experiences are as perceptually real as actual colors are for non-synaestetic observers, even in internally generated stimuli. It has been also suggested that individuals with synaesthesia may show hightened creativity as a result of being able to form meaningful association between these disparate stimuli. The present paper summarizes our current knowledge concerning synaesthesia including the personal experiences of some synesthetes with this peculiar gift.
- Klíčová slova
- osobní zkušenost,
- MeSH
- čití, cítění MeSH
- dítě MeSH
- dospělí MeSH
- kreativita MeSH
- lidé MeSH
- neurofyziologie MeSH
- synestezie MeSH
- vidění barevné MeSH
- vnímání barev MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- lidé MeSH
- Publikační typ
- autobiografie MeSH
