Changes In Colors Research Articles

Effect of color on the comprehensibility of pesticide pictograms by the agricultural workers in Central India

In the central Indian context, there are some pictograms used in almost all pesticide packaging. These pictograms depict the nature of pesticides, their correct dosage and handling. The objective of this study was to investigate the effect of different colors (black, red, yellow, green, blue, and pink) on the comprehensibility of pesticide pictograms. Thirty farmers were selected as the participants of this study. Two tests were conducted in this study, a Comprehension test and a Ranking test. In the Comprehension test, comprehensibility for different colors of pesticide pictograms was evaluated. In the Ranking test, the participant’s preference for colors was checked for the pesticide pictograms. Maximum comprehension level was observed for the pictogram of ‘Wash after using pesticide’ (100%) for all the colors. A minimum comprehension level was observed for the pictogram of ‘How to handle liquid’ (65%) for red color. Results indicated no significant variations (p > 0.05) in comprehension levels for changes in different colors of pesticide pictograms. Results of the ranking test indicated that the users preferred Red color (mean rank 1.37) for pesticide pictograms, while Yellow (mean rank 4.54) and Pink (mean rank 4.57) colors were the least preferred colors for pesticide pictograms. The results we mentioned are for comprehension level though no significant difference was noticed, but for the ranking test red color was preferred over other colors.

A Spectroscopic Model of the Type Ia Supernova–Host-galaxy Mass Correlation from SALT3

The unknown cause of the correlation between Type Ia supernova (SN Ia) Hubble residuals and their host-galaxy masses (the “mass step”) may bias cosmological parameter measurements. To better understand the mass step, we develop a SALT3 light-curve model for SN cosmology that uses the host-galaxy masses of 296 low-redshift SNe Ia to derive a spectral energy distribution–host-galaxy mass relationship. The resulting model has larger Ca ii H and K, Ca ii near-infrared triplet, and Si ii equivalent widths for SNe in low-mass host galaxies at 2.2–2.7σ significance; this indicates higher explosion energies per unit mass in low-mass-hosted SNe. The model has phase-dependent changes in SN Ia colors as a function of host mass, indicating intrinsic differences in mean broadband light curves. Although the model provides a better fit to the SN data overall, it does not substantially reduce data–model residuals for a typical light curve in our sample nor does it significantly reduce Hubble residual dispersion. This is because we find that previous SALT models parameterized most host-galaxy dependencies with their first principal component, although they failed to model some significant spectral variations. Our new model is luminosity and cosmology independent, and applying it to data reduces the mass step by 0.021 ± 0.002 mag (uncertainty accounts for correlated data sets); these results indicate that ∼35% of the mass step can be attributed to luminosity-independent effects. This SALT model version could be trained using alternative host-galaxy properties and at different redshifts, and therefore will be a tool for understanding redshift-dependent correlations between SNe Ia and their host properties as well as their impact on cosmological parameter measurements.

Mineralogy and Geochemistry of Nepheline Syenite From the Bang Phuc Massif of the Alkaline Cho Don Complex in North-Eastern Vietnam—Implications for Magma Evolution and Fluid–Rock Interactions

Abstract The alkaline Cho Don complex in NE Vietnam comprises several mafic-felsic suites related to the widespread magmatism developed during the early Permian–late Triassic. The contribution explores the petrogenesis of nepheline syenite from the Bang Phuc massif and its petrogenetic relationship with cogenetic scapolite-rich gabbro. The nepheline syenite formed through fractional crystallization of pristine mantle-derived basaltic melt modified by subduction-related components (chiefly sediment-derived melts), as shown by, e.g. low Ba/Th and high Th/Nb ratios of the rocks. The transition from gabbro to syenite follows a within-plate enrichment trend (e.g. increasing Ta/Yb, Nb/Yb, and Th/Yb ratios) that might reflect switch from post-orogenic to intra-plate regimes, accompanied by subduction–collision–extension events related to the Indosinian Orogeny. Furthermore, magma evolution involved the progressive contribution of asthenospheric-derived melts that resulted in the appearance of OIB-like signatures (e.g. high Nb/La ratios) in the nepheline syenite. Fractional crystallization of fluorapatite and mafic phases, as well as assimilation of carbonate wall rocks ultimately led to the decrease of LREE contents and/or modification of Zr/Hf ratios. Magmatic phases of the nepheline syenite include nepheline, sodalite, oligoclase, orthoclase, and annite, as well as accessory fluorapatite, fluorite, and minor amounts of zircon and metamict allanite-Ce. The nepheline equilibrated at temperatures ranging between 850°C and 700°C, which reflects protracted residence at a higher temperature. Later, it has been locally altered to cancrinite, dawsonite, and natrolite via CO2- and alkali-rich fluid influx. The fluid–rock interactions were also manifested by the presence of chessboard-twinned albite and coarsening of braid-perthite into patch-perthite, as well as recrystallization of primary orthoclase into microcline. The orthoclase→microcline conversion, albeit fairly indiscrete under a polarizing microscope and confirmed by Raman micro-spectroscopy, is followed by the change of cathodoluminescence colours, i.e. from light-blue (activated by Ti4+ and/or Al-O—Al centres) in orthoclase towards brownish and/or greenish (activated by Mn2+ and structural defects) in microcline.

Crystal-Liquid-Glass Transition and Near-Unity Photoluminescence Quantum Yield in Low Melting Point Hybrid Metal Halides.

Hybrid metal halides (HMHs) are a class of materials that combine extraordinary photophysical properties and excellent processability. Their chemical variability allows for the solid-liquid transition toward melt-processable HMHs. Herein, we report the design and synthesis of zero-dimensional HMHs [M(DMSO)6][SbCl6], where the isolated octahedra of [M(DMSO)6]3+ and [SbCl6]3- are alternatively aligned in the crystal structure. The luminescent center of [SbCl6]3- enables the photogeneration of self-trapped excitons, resulting in broadband photoluminescence with a large Stokes shift and a nearly 100% quantum yield. Meanwhile, the release of DMSO ligands from [M(DMSO)6]3+ is controlled by the M-O coordination and thus a low melting point of ∼90 °C is achieved for HMHs. Interestingly, the glass phase is obtained by melt quenching, with a sharp change in photoluminescence colors compared to the crystal phase of melt-processable HMHs. The robust crystal-liquid-glass transition opens a new avenue to tailoring structural disorder and optoelectronic performance in organic-inorganic materials.

Lizards exploit the changing optics of developing chromatophore cells to switch defensive colors during ontogeny

Many animals undergo changes in functional colors during development, requiring the replacement of integument or pigment cells. A classic example of defensive color switching is found in hatchling lizards, which use conspicuous tail colors to deflect predator attacks away from vital organs. These tail colors usually fade to concealing colors during ontogeny. Here, we show that the ontogenetic blue-to-brown tail color change in Acanthodactylus beershebensis lizards results from the changing optical properties of single types of developing chromatophore cells. The blue tail colors of hatchlings are produced by incoherent scattering from premature guanine crystals in underdeveloped iridophore cells. Cryptic tail colors emerge during chromatophore maturation upon reorganization of the guanine crystals into a multilayer reflector concomitantly with pigment deposition in the xanthophores. Ontogenetic changes in adaptive colors can thus arise not via the exchange of different optical systems, but by harnessing the timing of natural chromatophore development. The incoherent scattering blue color here differs from the multilayer interference mechanism used in other blue-tailed lizards, indicating that a similar trait can be generated in at least two ways. This supports a phylogenetic analysis showing that conspicuous tail colors are prevalent in lizards and that they evolved convergently. Our results provide an explanation for why certain lizards lose their defensive colors during ontogeny and yield a hypothesis for the evolution of transiently functional adaptive colors.

Intelligent Colorimetric Indicators for Quality Monitoring and Multilevel Anticounterfeiting with Kinetics-Tunable Fluorescence

The spoilage and forgery of perishable products such as food, drugs, and vaccines cause serious health hazards and economic loss every year. Developing highly efficient and convenient time-temperature indicators (TTIs) to realize quality monitoring and anticounterfeiting simultaneously is urgent but remains a challenge. To this end, a kind of colorimetric fluorescent TTI, based on CsPbBr3@SiO2 nanoparticles with tunable quenching kinetics, is developed. The kinetics rate of the CsPbBr3-based TTIs is easily regulated by adjusting temperature, concentration of the nanoparticles, and addition of salts, stemming from the cation exchange effect, common-ion effect, and structural damage by water. Typically, when combined with europium complexes, the developed TTIs show an irreversible dynamic change in fluorescent colors from green to red upon increasing temperature and time. Furthermore, a locking encryption system with multiple logics is also realized by combining TTIs with different kinetics. The correct information only appears at specific ranges of time and temperature under UV light and is irreversibly self-erased afterward. The simple and low-cost composition and the ingenious design of kinetics-tunable fluorescence in this work stimulate more insights and inspiration toward intelligent TTIs, especially for high-security anticounterfeiting and quality monitoring, which is really conducive to ensuring food and medicine safety.

PEMETAAN POLA SUHU PERMUKAAN TUBUH KUDA MENGGUNAKAN KAMERA TERMAL INFRAMERAH

Infrared thermal camera is an alternative and non-invasive method used to identify various physiological and pathological process related to body surface temperature changes. The aim of this research was to study the body surface temperature pattern based on the observed regios. Three horses were randomly selected as animal experiments. Thermal image data was collected at 17.00 – 19.00 WIB for five days. Images were retrieved from seven regios: head, thorax, abdomen, and four lower legs. The result of horse A’s surface temperature in five days on head, thorax, abdomen, front left leg, front right leg, rear left leg, and rear right leg regios were 33.42, 33.49, 33.56, 31.30, 31.48, 31. 33.14, 31.34 °C, respectively. The resulf of horse B’s surface tempereture were 33.55, 33.65, 33.64, 31.45, 31.35, 31.53, 31.48 °C, respectively. The resulf of horse C’s surface tempereture were 33.45, 33.55, 33.60, 31.37, 31.45, 31.34, 31.42 °C, respectively. The result showed that difference on horse A’s rear left leg (p<0.05) because of inflamation. Inflamation recovery process on horse A occured on the fifth day, indicated by a drop in temperature and a change in colors on thermal image. Color noises on some images were color difference between objects and poor color saturation. Color noises on thermal images did not affect the results of temperature interpretation.

Prevention of Chilling Injury in Pomegranates Revisited: Pre- and Post-Harvest Factors, Mode of Actions, and Technologies Involved.

The storage life of pomegranate fruit (Punica granatum L.) is limited by decay, chilling injury, weight loss, and husk scald. In particular, chilling injury (CI) limits pomegranate long-term storage at chilling temperatures. CI manifests as skin browning that expands randomly with surface spots, albedo brown discoloration, and changes in aril colors from red to brown discoloration during handling or storage (6-8 weeks) at <5-7 °C. Since CI symptoms affect external and internal appearance, it significantly reduces pomegranate fruit marketability. Several postharvest treatments have been proposed to prevent CI, including atmospheric modifications (MA), heat treatments (HT), coatings, use of polyamines (PAs), salicylic acid (SA), jasmonates (JA), melatonin and glycine betaine (GB), among others. There is no complete understanding of the etiology and biochemistry of CI, however, a hypothetical model proposed herein indicates that oxidative stress plays a key role, which alters cell membrane functionality and integrity and alters protein/enzyme biosynthesis associated with chilling injury symptoms. This review discusses the hypothesized mechanism of CI based on recent research, its association to postharvest treatments, and their possible targets. It also indicates that the proposed mode of action model can be used to combine treatments in a hurdle synergistic or additive approach or as the basis for novel technological developments.

The mechanical implementations in three kinds of color-changing beetle elytra

With superior adaptability, some elytra as modified forewings can provide mechanical protection for the underlying hind wings and soft body while changing in color in a dynamically natural environment. There are mainly three color-changing styles for elytra: angle-dependent, irreversible and reversible color changes. Here, Popillia indgigonacea Motsch, Sagra femorata purpurea Lichtenstein and Dynastes tityus were chosen as specimens to investigate the relationship between the color formation of the three color-changing styles and the mechanical properties of light weight and high strength. The optical and nanomechanical properties of purplish red S. femorata purpurea Lichtenstein were studied by using an angle-resolved spectroscopy system and a nanoindenter, respectively. In finite-element analysis, three geometrical structural models – namely, color-change-relevant, color-change-irrelevant and whole-elytron models – were designed, and then the mechanical properties of six coupled bionic models of each beetle were investigated. The multilayer, convex closures and photonic crystal in the epicuticle can complete the dynamic presentation of structural colors by interference, scattering and photonic bandgap as they when resourcefully resist the external forces in low/high stress and strain with high/small elastic modulus and hardness. Meanwhile, other microstructures of multilayer and trabecular hollow were reasonably constructed to display co-operatively the mechanical properties of light weight and high strength.

모형배전반 차광과 색상에 따른 내·외부 온도변화 기초 실험

In this study, in order to examine the method of suppressing the temperature rise of the switchboard exposed to direct sunlight, the variation of temperature in its inside was measured by shading of sunlight. In addition, the temperature changes according to the color of the green and white roof, and the paint color of the switchboard were examined by an experimental method as a Cool Roof effect. The installation of shading net reduced the temperature by about 10℃ or more. The temperature change of colors was measured at 63°C for green and 38°C for white, with a temperature deviation of 25°C. In addition, the gray switchboard surface was 51.4℃ and the white switchboard surface was 43. 6℃, confirming the temperature reduction effect of about 8℃.

DISCURSO ESCRITO DE JUEGOS DE AZAR EN LA LENGUA ESPAÑOLA

The aim of our studies is to suggest the definition of gambling discourse, to define its types and to describe lexico-grammar, sintactic and graphic peculiarities of the texts included in gambling discourse. The studied discourse belongs to institutional and ritual discourse because gambling games possess rules which the gamblers should follow obligatorily. Gambling discourse is represented by oral and written form. We determine various types of texts belonging to the gambling discourse: advertising texts in the sphere of gambling; specialized texts of gambling discourse; texts of gamblers’ communication during the game and outside the game. Among lexical resources of gambling discourse we single out gambling terms, words of positive evaluation, metaphors, metonymy, hyperbole, comparison. Grammar and syntactic resorces include nominative and imperative sentences, rhetoric questions which communicate a dialogue character to written gambling discourse and motivate potential gamblers to play. Graphic means are characterized by the use of symbols, numbers, verbal and non verbal resources, such as change of colors and sizes, capitalization, animation, outlined text, links to other web pages dedicated to gambling. The range of lexical, grammar, syntactical and graphic means represent a positive image of a game and incent the gamblers to play. The texts of gambling discourse perform nominative, informative and expressive functions.

Supramolecular assembly of dendronized spiropyrans in aqueous solutions into nanospheres with photo- and thermo-responsive chiralities.

Tailoring the amphiphilicity of a molecule through external stimuli can alter the balance between self-association and repulsion, resulting in different propensities for its assembly. Here we report on the supramolecular assembly of a series of dendronized spiropyrans (DSPs) in water. These DSPs carry 3-fold dendritic oligoethylene glycols (OEGs) with either methoxyl or ethoxyl terminals for different hydrophilicities, and contain an Ala-Gly dipeptide to provide the chirality. These dendronized amphiphiles form supramolecular nanospheres in aqueous solutions with remarkable induced chirality to a level of 1.0 × 106 deg cm2 dmol-1. They can be tuned reversibly through photoisomerization of the spiropyran moieties from the hydrophobic SP form into the hydrophilic MC form, and can even become chirally silent through thermally mediated collapse of the dendritic OEGs. Photoisomerization of the spiropyran moieties in these DSPs is accompanied by simultaneous changes of UV absorption, fluorescence emission, supramolecular chirality and aqueous solution colors. These supramolecular nanospheres exhibit characteristic thermoresponsive behavior due to thermal collapse of the dendritic OEGs with their cloud point temperatures (Tcps) being dependent on the overall hydrophilicity of the molecules and also the aggregate morphologies resulting from how dendritic OEGs are wrapped around the aggregates. Both photo-irradiation-mediated isomerization of the spiropyran moieties and thermally mediated dehydration and collapse of the dendritic OEGs influence the amphiphilicity of these DSPs and their solvation by water, leading to varied driving forces for their assembly. NMR, circular dichroism (CD) and fluorescence spectroscopy techniques, as well as DLS and AFM techniques are combined to follow the supramolecular assembly and illustrate the aggregation mechanism. All experimental results demonstrate that the reversible chirality of the aggregates originates from the balance between dendritic OEGs and spiropyran moieties against water solvation.

Investigation of Color Change of Different Restoration Thickness, Background Color and Resin Cement Shade on CAD/CAM Glass Ceramic Materials

The aim of this study is to investigate the color change of different restoration thicknesses, backgrounds and resin cement colors on lithium disilicate and zirconium reinforced lithium silicate materials in vitro. In this study, IPS emax CAD (LT C14) and Celtra Duo (LT C14) are used as full ceramic materials, and Variolink Esthetic LC (warm, neutral) used as resin cement and Tokuyama Estelite Sigma Quick (A3, A2) is used as composite materials. A total of 160 samples in the form of 40 pieces of 5 × 5 0.4 mm thick 40 pieces of 5 × 5 0.6 mm thick square discs from each of the all-ceramic materials in block form were obtained using a water jet device (DWJ1525-FA; Dardi International Corporation, Nanjing, China). Glass ceramic samples produced in 2 different thicknesses were cemented on 2 different backgrounds with 2 different resin types of cement. Color measurements of the samples before and after cementation were performed on a grey background with spectrophotometer Vita EasyShade V (Vita Zahnfabrik, Bad Sackingen, Germany) and color parameters (L*, a*, b*, ΔE) were calculated according to the CIE Lab (Commission Internationale de L’Eclairage) system. Average values for each group (ΔE) were not affected by ceramic type, material thickness, background color, resin cement color, and the interaction of these four variables (p > 0.05). When the triple interactions between the groups were examined, there were no statistically significant differences (p > 0.05). In the evaluation of pairwise interactions between two groups (material type-material thickness, material type-background color, and thickness of material-background interactions) statistically significant differences (p 0.05).

Multifunctional Fluorescent Materials with Reversible Mechanochromism and Distinct Photochromism

AbstractIt is extremely significant and desirable to integrate the fascinating mechanochromism and photochromism in one simple molecule. Herein, two intriguing cyanostilbene‐containing triphenylamine (TPA)/tetraphenylethylene (TPE) derivatives (Z‐TPA‐MB and Z‐TPE‐MB) are elaborately designed, which not only display excellent aggregation‐induced emission (AIE) properties with high solid‐state fluorescence quantum yields (60.9% and 63.8%) but also exhibit reversible and high contrast mechanochromism and distinct photochromism. The powders of Z‐TPA‐MB and Z‐TPE‐MB both exhibit large red‐shift under mechanical stimulation based on the highly twisted conformation and the resulting loose packing mode, accompanied by significant changes in apparent and fluorescent colors. Meanwhile, their solid‐state fluorescence can be reversibly switched between crystalline and amorphous structures through alternating grinding and solvent fuming, exhibiting good fatigue resistance. In addition, the molecules also exhibit distinct dual‐mode photochromic behaviors owing to the presence of cyanostilbene moieties: under 420/365 nm light irradiation, the fluorescence of which decreases in solution owing to the photo‐isomerization, while decreases and blue‐shifts in the aggregated state owing to the photodimerization reactions. The reversible, tractable, and high‐contrast mechanochromism and distinct photochromism of the cyanostilbene‐containing molecules endow them with excellent application prospects in the field of rewritable papers and photo‐patterning.

Synthesis of a naphthalenediimide with photo-induced fluorescence enhancement and its visual dual-response to highly polar solvents

A photochromic 1,4,5,8-naphthalenediimide (NDI) derivative N,N-bis(4,6- diamino-1,3,5-triazinyl-2-)naphthalenediimide (DDNDI) was synthesized and the photo-induced fluorescence enhancement of DDNDI was found for the first time for NDI materials, the fluorescence intensity increases with the increase of sunlight or UV irradiation time. For sunlight irradiation, it shows a linear relationship of y=22.38821x+85.37868 (R=0.9987). And the photochromism and fluorescence of the DDNDI solution have synchronous “on-off” characteristic. Under continuous irradiation, the photochromic color of the DDNDI solution changes from colorless to yellow and the fluorescence color changes from colorless to green. After adding polar solvent, photochromism and fluorescence can be suppressed simultaneously due to the twisted intramolecular charge transfer (TICT) and the photoinduced electron transfer (PET). Based on the dual changes of photochromic and fluorescent colors caused by UV, visual dual-response to highly polar solvents can be observed, and the fluorescence intensity is linearly related to the amount of the added DMSO: y=-1.21857x+780.04855 (R=0.9966). • Photo-induced fluorescence enhancement for the naphthalenediimide materials is found first. • The photo-induced fluorescence enhancement is linearly related to the sunlight irradiation time. • The mechanism is investigated by the turn on and off of the fluorescence and photochromism simultaneously.

드라마의 색채 활용 및 인식에 관한 연구

This study analyzed the use of colors in dramas and perception changes according to color changes of viewers through the drama The Penthouse: War in Life. First, the color changes of three representative episodes of ‘revenge’, ‘crime’, and ‘desire’ that constituted the main story were examined. Uses of colors in various mise-en-scène was analyzed. As a result, The Penthouse: War in Life increased viewers’ tension by changing background colors according to changes in the story or achieved climactic atmosphere through changes in costumes and lighting and delivered the drama’s contents more effectively. In addition, it was confirmed that the viewers received different meanings from the same video according to the strong color contrast that represented mental state of characters and the flow of the story and the change of the symbolic colors. In this way, through the use of colors in video production, it is possible to increase the immersion of viewers and increase the atmosphere of the drama as well as increase the video aesthetics.

A clinical case of catarrhal mastitis in a cow

Food security includes not only the provision of basic foodstuffs to the population but also the guarantee of their quality and safety for the consumer. These criteria are essential for milk as the primary food product. The pathological processes, which are developed in the breast, harm the quality of milk, and the medical products used in their treatment, may affect the safety of this product. The article has represented the results of the bioregulatory approach in treating catarrhal mastitis in cows using medical products containing ultra-low doses of biologically active substances. These products do not have a withdrawal period regarding milk. The use of this approach makes it possible to increase the safety of treatment, which in turn will lead to economic benefits. Clinical symptoms of mastitis were determined by clinical signs (increasing local temperature, soreness, thickening of the udder, changing in color and consistency of milk, presence of flakes and clots). A сow No. 3095 was selected with characteristics of clinical symptoms of catarrhal mastitis of the rear left lobe of the udder. The following scheme was used for therapy: intramuscular injection of Traumeel 10 ml once a day, intracisternal injection of Lachesis Сompositum 10 ml into the affected part once a day, Traumeel(gel) locally after milking. The choice of bioregulatory preparations was based on the components and their action. On the third day, the cow's udder swelling decreased, local temperature normalized. The color and consistency of milk during control milking and its examination with the Avita diagnostic test showed an improvement from (+++) to (++). Complete clinical and laboratory recovery was diagnosed on the sixth day. A cow was returned to the general herd. Based on the treatment results, it can be concluded that this treatment scheme for catarrhal mastitis is effective. The absence of a withdrawal period regarding milk and the acceleration of recovery rates make it economically profitable.

Trichromatic ratiometric fluorescent sensor based on machine learning and smartphone for visual and portable monitoring of tetracycline antibiotics

In this work, a tri-color ratiometric fluorescent optical device integrated with machine learning-assisted smartphones is designed for the visual monitoring of tetracycline antibiotics. The trichromatic sensing probe consists of blue emitting carbon dots (BCDs) at 420 nm, and red-emitting bovine serum albumin-protected copper nanoclusters (BSA-Cu NCs) at 635 nm, as well as an emission peak at 520 nm, rises in the presence of tetracycline antibiotics (TCs), therefore, a three emission system is formed. BCDs/BSA-Cu NCs present three emission responses to TCs, which are based on the internal filtering effect (IFE) and the sensitization mechanisms with BSA. The reaction mechanism was verified by density functional theory (DFT) and a series of characterizations, such as infrared spectrum, ultraviolet absorption spectrum, and fluorescence lifetime. Interestingly, the fluorescence intensity of BCDs was quenched by TCs, and due to the sensitization between BSA and TCs, a green fluorescence rose at 520 nm, while the peak of BSA-Cu NCs remained stable, resulting in a significant color shift from red to cyan. Therefore, the ratiometric fluorescence intensity of I(635+520)/I420 can be used to determine TCs, and the colors change can be used to identify the quantitative analysis. In addition, the deep learning of the YOLO v3 algorithm assists the integrated tri-color portable optical device of smartphones, which can realize the visual detection of TCs. In general, the sensing system has many advantages, such as good stability, specificity, and rich color changes, which provide help for the visual detection of tetracycline residues.

The accumulation of organic contaminants in hair with different biological characteristics

Human hair has increasingly been used as a noninvasive biomonitoring matrix for assessment of human exposure to various organic contaminants (OCs). However, the accumulation processes of OCs in hair remains unclear thus far, which raised concerns on the reliability of hair analysis results for OCs. Herein, Chinese population was selected as the study subject, the effects of changes in hair biological characteristics, including length and color, on the accumulation of OCs in hair was investigated. With the growing of hair shaft and the increased distance from the scalp, a significant increasing trend was found for levels of polychlorinated biphenyls (PCBs) and organophosphate flame retardants (PFRs) along the hair shafts (p < 0.05). Source identification using Chemical Mass Balance model indicated that PCBs in hair were mainly from exogenous sources (air and dust). The accumulation rates of PCB and PFR individuals in the hair shaft decreased with increasing of log Kow values. Additionally, the levels of OCs in hair decreased with the change in color from black to white, probably because of the loss of melanin in white hair. The ratios (R) of Cblack/Cwhite were significantly correlated with the log Kow values for individual chemicals (p < 0.05), implying that OCs with high log Kow values tend to accumulate more readily in black hair. The results of this study demonstrated the growth and change in colors of hair, as well as the physicochemical properties of chemicals, play vital roles in the accumulation of OCs in hair. The present study provides fundamental basis for the precise assessment of human exposure to OCs using hair as a biomonitoring matrix in future studies.

Micropatterned Hydrogels with Highly Ordered Cellulose Nanocrystals for Visually Monitoring Cardiomyocytes (Small 45/2022)

Cardiomyocyte Monitoring In article number 2202235, Chunyu Chang, Donghui Zhang, and co-workers develop micropatterned hydrogels with anisotropic structural colors by locking shear-oriented tunicate cellulose nanocrystals (TCNCs) in hydrogel networks through in situ polymerization. The autonomous beating of cardiomyocytes drives synchronous deformations of the micropatterned hydrogels, causing periodic changes in transmittance colors. This system has potential as a high-throughput assay to visually monitor cardiomyocyte function.