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1.
Heliyon ; 10(12): e32938, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38994067

RESUMO

Significance: Blue light with wavelengths of 380-445 nm can harm the retina, leading to the development of blue-blocking lenses (BBLs). Understanding whether BBLs affect color vision test outcomes and color discrimination ability is crucial for people in color-associated jobs. Aim: This study aimed to evaluate the effect of BBLs on color vision tests and analyze color discrimination using mathematical models of color spaces. Approach: Six pseudoisochromatic (PIC) tests and two Farnsworth-Munsell (FM) tests were conducted to assess participants' color vision. Friedman signed rank test was used to compare the outcomes of the Farnsworth-Munsell 100-Hue Tests (FM 100-Hue Tests) between the BBLs and ordinary lenses groups. The CIE color difference formula and a spectral illuminometer were employed to evaluate the color differences with and without BBLs. Results: All subjects showed normal outcomes in all PIC tests and Farnsworth-Munsell Dichotomous D-15 Tests (FM D-15 Tests). There were no significant differences between ordinary lenses group and BBLs groups in FM 100-Hue Tests. In the color space, the effect of BBLs on each color light was equivalent to a translation on the CIE 1931 chromaticity diagram with minor distortion. Since BBLs do not disrupt the continuity of the chromaticity diagram, or cause different colors to appear the same, they do not lead to color confusion. However, colors with short wavelengths exhibited more changes in color difference when wearing BBLs. Conclusions: BBLs do not impair the wearer's ability to discriminate colors or perform color vision tests accurately. However, BBLs can cause color differences especially in the recognition of blue hues.

2.
Appl Radiat Isot ; 210: 111380, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38830278

RESUMO

This study explores the structural and luminescent properties of terbium (Tb³âº)-doped lanthanum aluminium borate (LaAl2B4O10, abbreviated as LAB) phosphors, a novel host lattice for Tb³âº doping. LAB:Tb³âº phosphors, with varying dopant concentrations, were synthesized using a microwave-assisted combustion synthesis approach and characterized using X-ray diffraction (XRD), Rietveld refinement, and photoluminescence spectroscopy at both room and low temperatures. The structural analysis confirmed the hexagonal crystal structure of LAB and revealed successful incorporation of Tb³âº ions without altering the fundamental lattice. Luminescence studies demonstrated that the LAB:Tb³âº phosphors show strong green emission primarily attributed to the 5D4→7F5 transition of Tb³âº. The optimal doping concentration was determined to be 5 wt% Tb³âº, which provided maximum luminescence efficiency. This concentration also allowed for a critical study of energy transfer mechanisms within the phosphor, revealing dipole-dipole interactions with a critical distance of 9.80 Å between Tb³âº ions. Additionally, the CIE chromaticity coordinates of LAB:0.05 Tb³âº were precisely determined to be (0.289, 0.4460), indicating the potential for high-quality green emission suitable for solid-state lighting and display technologies. This work not only demonstrates the potential of LAB:Tb3+ as a highly efficient green luminescent material, but also sheds light on the mechanisms responsible for energy transfer and concentration quenching.

3.
Appl Spectrosc ; : 37028241257267, 2024 Jun 11.
Artigo em Inglês | MEDLINE | ID: mdl-38860879

RESUMO

Passive infrared (IR) systems enable rapid detection of chemical vapors but are limited by size, weight, cost, and power. Previously, the authors reported a novel passive sensor that utilizes multiple IR filter/detector combinations to discriminate between different chemical vapors based on their unique IR absorption spectra in the same manner the human eye uses to generate colors. This approach enables a very small, compact, and low-power sensor system with the capability to discriminate between chemical vapors of interest and background chemicals. All previous work showed the capability of this sensor system in discriminating chemical vapors against a hot blackbody in a laboratory environment. Now the authors demonstrate the ability of this sensor system to discriminate between the chemical vapor agent simulant dimethyl methylphosphonate and ethanol against the cold sky in an outdoor environment.

4.
Dent Mater J ; 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-38925979

RESUMO

No effective technique exists for removing adhesive remnants following bracket debonding. We propose that fluorescence imaging using europium ions (Eu3+) offers an effective solution for minimizing iatrogenic enamel damage. This study aimed to assess the impact of different mixing ratios of monomer mixtures on the photoluminescence and flexural properties of a newly developed fluorescent adhesive. Four monomer blends with varying urethane dimethacrylate (UDMA) to triethylene glycol dimethacrylate (TEGDMA) ratios were prepared and polymerized. The blends contained 0.1 wt% of tris(1,3-diphenyl-1,3-propanedionato)(1,10-phenanthroline) Eu(III), [Eu(DBM)3Phen], as the phosphor. Optical measurements and flexural tests were conducted for each resin specimen. The emission spectra exhibited narrow bands corresponding to the 4f-4f transitions of the Eu3+ ions. The photoluminescence properties remained unaffected by the mixing ratio, whereas the mechanical properties tended to improve with higher UDMA content. We conclude that the Eu(DBM)3Phen-containing resin shows promise as a fluorescent orthodontic adhesive that contributes to preserving enamel health.

5.
Zhongguo Zhong Yao Za Zhi ; 49(7): 1865-1871, 2024 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-38812198

RESUMO

This study aims to reveal the dynamics of the HPLC fingerprint, chromaticity values, and main chemical components of Mori Cortex during the stir-frying process. The fingerprints of raw and processed products of Mori Cortex were established. The content of mulberroside A, oxyresveratrol, kuwanon G, and kuwanon H in the samples and the chromaticity values of the samples were determined. Furthermore, the similarity evaluation of fingerprints and the correlation analysis between fingerprints and chromaticity values were carried out. The results showed that the fingerprints of raw and processed products of Mori Cortex had high similarity, and the overall changes in the content of the main chemical components in the stir-frying process were similar. According to the experience, when the stir-frying is moderate, the total chromaticity value difference |ΔE~*_(ab)| is above 1.5. With the extension of stir-frying time, the L~* and E~*_(ab) values keep decreasing, and the a~* value keeps increasing. The results of the correlation analysis between fingerprints and chromaticity values showed that peaks 1(5-hydroxy maltol), 2(mulberroside A), 3, 4, 6, 7, 11(oxyresveratrol), 14, 17(kuwanon G), and 18(kuwanon H) had significant correlations with the chromaticity values. Quantitative analysis of the four components with higher content showed that the content of the four components decreased to varying degrees when the stir-frying was excessive. In addition, 5-hydroxy maltol was produced after stir-frying of Mori Cortex, and the fingerprint and chromaticity values showed regular changes during the stir-frying process. The chromaticity can be included in the evaluation of the stir-frying process of Mori Cortex, which provides a reference for standardizing the quality of stir-fried Mori Cortex.


Assuntos
Medicamentos de Ervas Chinesas , Morus , Cromatografia Líquida de Alta Pressão , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/análise , Morus/química , Dissacarídeos , Estilbenos
6.
J Fluoresc ; 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38558125

RESUMO

In the present work, we synthesized 3-chloro-6-methoxy-2-(methyl sulfanyl) quinoxaline (3MSQ) using a microwave-assisted synthesis method. The physicochemical structural analysis of the synthesized compound utilizing 1H-NMR, 13C-NMR, and FT-IR spectroscopy techniques. The photophysical properties of 3MSQ was examined through absorption and fluorescence spectroscopy. Spectroscopic analyses revealed a bathochromic shift in both absorption and fluorescence spectra, attributed to the π → π* transition. Ground and excited state dipole moments was experimentally determined using the solvatochromic shift method, employing various correlations such as Lippert's, Bakhshiev's, Kawski-Chamma-Viallet's equations, and solvent polarity parameters. Our findings indicate that the excited state dipole moments exceed those of the ground state, suggesting increased polarity in the excited state. Further, the while detailed bond length, bond angles, dihedral angles, Mulliken charge distribution, ground state dipole moments and HOMO-LUMO energy gap estimated through ab initio computations using Gaussian-09W. The value of energy band gap obtained from both the methods are in good agreement. Furthermore, employing DFT computational analysis, we identified reactive centers such as electrophilic and nucleophilic sites using molecular electrostatic potential (MESP) 3D plots. Additionally, CIE chromaticity analysis was performed to understand the photoluminescent properties of 3MSQ. The insights derived from these analyses contribute to a better understanding of the molecule's electronic structure, photophysical properties, and solute-solvent interactions, thus providing valuable information regarding its behaviour and characteristics under diverse conditions. These results contribute to a comprehensive understanding of the molecular structure and properties of 3-chloro-6-methoxy-2-(methyl sulfanyl) quinoxaline (3MSQ).

7.
Angew Chem Int Ed Engl ; 63(27): e202318949, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38446671

RESUMO

Lanthanoid carboxylates were synthesized and in situ self-assembled to illustrate temperature-driven evolution in chromaticity. Evolution in structure (crystallinity), composition, luminosity, and chromaticity were investigated revealing the coupled role of divergence in order/structure (spatial organization), and composition in tuning observed color. Loss of crystallinity or increase in residual carbon leads to decrease in luminosity even with increase in hue. Comparing Ho and Er congeners shows that the density of accessible transition states relates to shifts in low and high wavelength components of color. This work demonstrates that, just as interface dipoles can lead to change in semiconductor band gap, structure and composition can analogously alter observed color.

8.
Heliyon ; 10(3): e25064, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38352738

RESUMO

Breast cancer remains a significant global health concern, necessitating the development of novel therapeutic approaches. In this study, we investigate the role of Eu3+ doped hydroxyapatite nanocomposites (Han: Eu3+) in the treatment of MCF7 and 4T1 breast cancer cell lines. Furthermore, we explored the structural and luminescent properties of these nanocomposites. Han: Eu3+ were synthesized using a modified co-precipitation method, and their morphology and crystal structure were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD) in which the average crystalline size of Han: Eu3+ was found to be 25 nm, rendering them suitable for cellular uptake and targeted therapy. To gain insights into the luminescent properties of Han: Eu3+, their excitation and emission spectra were recorded using photoluminescence spectrometer. The characteristic red emission of Eu3+ ions was observed upon excitation, validating the successful doping of Eu3+ into the Han lattice, which was confirmed by the CIE chromaticity coordinate study. These luminescent properties of Han: Eu3+ hold promise for potential applications in bioimaging. To evaluate the efficacy of Han: Eu3+ in breast cancer treatment, MCF7 and 4T1 cell lines were exposed to varying concentrations of the nanocomposites. Cell viability assays revealed a concentration-dependent reduction in cell viability, indicating the potential anticancer activity of Han: Eu3+. The findings of this study contribute to the expanding field of nanomedicine, bringing targeted breast cancer treatments and us closer to more effective.

9.
J Prosthodont ; 2024 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-38288518

RESUMO

PURPOSE: Speed sintering was introduced to fabricate time-efficient chairside restorations, however, its influence on the microstructure and optical properties of zirconia is still unclear. This study investigated the influence of speed sintering on the microstructure and optical properties of ultra-translucent multi-layered cubic zirconia. MATERIALS AND METHODS: Ultra-translucent cubic zirconia (Katana™ UTML; Kuraray Noritake Dental Inc., Aichi, Japan) was cut into a total of 80 specimens, twenty within each layer of the blank. The specimens were divided into 2 groups: speed and conventional sintering. The translucency parameter, opalescence, chromaticity, and color difference were recorded using a spectrophotometer. Scanning electron microscope images were used for crystallographic analysis. One-way ANOVA and Tukey's post-hoc test (p < 0.05) were used for data analysis. RESULTS: Speed sintering significantly reduced the translucency and opalescence compared to conventional sintering excluding the opalescence of the dentin layer. Chromaticity significantly decreased with speed sintering in less chromatic layers and significantly increased in more chromatic layers. Mean color change ranged between 0.65 and 1.25 across different layers. Mean crystal size decreased with speed sintering. CONCLUSIONS: With speed sintering, translucency, and opalescence decrease while chromaticity increases in the more chromatic layers. Additionally, no clinically perceptible color change was found compared to conventional sintering.

10.
J Pharm Biomed Anal ; 241: 115968, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38280238

RESUMO

The dried young fruit of Citrus reticulata Blanco, known as Qingpi, is commonly used in clinic both with its raw and vinegar-processed products. However, the distinctions in quality between these two products remain unclear, and the methods for identification are considerably intricate. In this study, an electronic eye technique was applied to assess the overall color of Qingpi products before and after processing. The luminosity (L*) and yellow-blue (b*) values of Qingpi decreased after vinegar processing, while red-green (a*) values increased. The discriminant function models based on color parameters were established to effectively classify the two products. The chemical compositions of different Qingpi products were characterized using ultra-high performance liquid chromatography fingerprint technology, and 10 distinct components were considered as potential chemical markers. The correlation analysis revealed a significant relationship between chromatic values and chemical components. In conclusion, the results of this study suggested that chromaticity can be effectively considered as a valuable instrument for the prediction of component content in both raw and vinegar-processed Qingpi products. This study will provide new ideas and methods for identification and quality evaluation of Qingpi processed products, as well as provide a reference for standardizing traditional Chinese medicine processing techniques.


Assuntos
Medicamentos de Ervas Chinesas , Medicamentos de Ervas Chinesas/química , Ácido Acético , Medicina Tradicional Chinesa , Análise Discriminante , Cromatografia Líquida de Alta Pressão/métodos
11.
J Fluoresc ; 34(2): 915-923, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37418200

RESUMO

Fluorescence spectra of Pr3+ doped CdS nanoparticles, synthesized by chemical precipitation method, have been recorded at room temperature. The synthesized particles are nearly spherical shaped and the grain size is decreased with the increase in Pr3+ concentration. The chemical identity of the nanoparticles was confirmed by EDAX spectrum, the absorption peaks was confirmed by FTIR spectrum and then the recorded values were compared with the CIE diagram. The oscillator strengths of the 4f ↔ 4I transitions are parameterized in terms of three phenomenological Judd-Ofelt intensity parameters Ωλ (λ = 2, 4 and 6). Using the fluorescence data and these Ωλ parameters, theoretical and experimental study of various radiative properties viz., spontaneous emission probability (A), radiative life time , fluorescence branching ratio and stimulated emission cross-section were evaluated. The values of these parameters indicate that 3P0→ 3H4 transition can be considered to be good laser transition in the visible colour region. Also, excitation with 493 nm, leads to similar blue regions. The synthesized Pr3+ doped CdS nanomaterials could be useful for sensing and detecting devices, particularly for temperature sensing measurement and bio-sensing detection.

12.
Spectrochim Acta A Mol Biomol Spectrosc ; 308: 123757, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38142490

RESUMO

A novel Fluro boro-phosphate host matrix doped with the 1 mol% of Dy3+ ions (50B2O3 + 20P2O5 + 10TiO2 + 10SrCO3 + 4BaF2 + 5BaCO3 + 1Dy2O3) was prepared using a conventional melt-quenching mechanism, and its structural characteristics were explored through the Powder-XRD, FT-IR, FT-Raman, EDAX and SEM spectroscopic analysis. The XRD spectrum of the glass confirmed its non-crystalline or amorphous structure. FT-IR and FT-Raman spectrum studies revealed that various borate and phosphate groups present with a variety of stretching and bending vibrations. Scanning Electron Microscope (SEM) and Energy Dispersive X-ray analysis (EDAX) analysis have been used to examine the surface morphology and the presence of elements, respectively in the prepared glass. The optical absorption spectrum was used to explore the electronic band structure through the measurements of optical band-gap energy and Urbach energy. The luminescence spectrum reveals the emission characteristics of Dy3+ ions due to the electric-dipole and magnetic-dipole transitions. It is found that the decay time of the 4F9/2 excited level at a concentration of 1 mol% Dy3+ in the glass matrix is tri-fit non-exponential. The CIE chromaticity coordinates and the concentration influence on Y/B intensity ratios were computed for the creation of white light from the luminescence spectrum. The present work also discusses the findings after figuring out the correlated color temperature associated (CCT) with the color purity (Pe). The Thermoluminescence (TL) characteristics and the kinetic parameters of the glass were studied after the γ-irradiation with a dose of 2 kGy. EPR investigation revealed the paramagnetic characteristics through the hyperfine structure of Dy3+ ions and the electron-hole pair formation upon irradiation in the glass matrix.

13.
Sci Total Environ ; 912: 169506, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38123084

RESUMO

This study focused on the removal of the total coliforms, fecal coliforms and four target antibiotics in the dissolved ozone flotation (DOF) thickening sludge process. Additionally, the thickened effluent chromaticity and its effect on thickened sludge hydrolysis process were investigated. Ozonation in the DOF process could inactivate coliforms by oxidizing cellular components and destroying genetic material, as well as altering the chemical structure of antibiotics, leading to the degradation of antibiotics. At an O3 dosage of 16 mg/g TS, the concentration of total coliforms and fecal coliforms decreased by 2.2 log and 2.4 log, corresponding to an overall removal rate of 99.4 % and 99.7 %, respectively. The total degradation rate of four target antibiotics (tetracycline (TC), oxytetracycline (OTC), norfloxacin (NOR), ofloxacin (OFL)) were 66.5 %, 68.8 %, 53.3 % and 57.5 %, respectively. The chromaticity removal rate of the thickened effluent reached 95 %. Analysis of fluorescence spectra indicated alterations in the fluorescence properties of dissolved organic matter, resulting in a decrease in fluorescence intensity by ozonation. The thickened sludge had higher hydrolysis rates, resulting in a greater production of volatile fatty acids (VFAs). This was mainly attributed to the increased amount of soluble protein and carbohydrate in the substrate after DOF treatment, which was more conducive for the rapid conversion of hydrolysis into VFAs during the initial stage. These results provided new ideas for upgrading and transforming the thickening process of wastewater treatment plants (WWTPs).


Assuntos
Antibacterianos , Ozônio , Ozônio/química , Esgotos/química , Tetraciclina , Bactérias
14.
J Fluoresc ; 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38051400

RESUMO

Lithium-aluminum-borate glasses doped with single, double, or triple Tm3+, Tb3+, or Eu3+ ions, respectively, at several concentrations were prepared. Structural characterization was performed using optical absorption and luminescence spectroscopy. The transition for the rare earth ions under study was observed in optical absorption and some for-host glass at wavelengths less than 300 nm. The luminescence of Eu3+, Tb3+, and Tm3+ is presented as bright red, green, and blue emissions, respectively. White light was produced by adjusting the excitation wavelength and doping concentration of Tm2O3, Eu2O3, and Tb4O7. The sample doped with triple rare earth ions produced color emissions from Tb and Tm to Eu, which varied in hue based on the excitation wavelengths of 350, 360, and 370 nm. The glass samples under investigation may be promising for optoelectronic devices and security applications such as data encryption.

15.
Food Chem X ; 20: 101022, 2023 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-38144802

RESUMO

Ziziphi Spinosae Semen (ZSS) is a valued seed renowned for its sedative and sleep-enhancing properties. However, the price increase has been accompanied by adulteration. In this study, chromaticity analysis and Fourier transform near-infrared (FT-NIR) combined with multivariate algorithms were employed to identify the adulteration and quantitatively predict the adulteration ratio. The findings suggested that the utilization of chromaticity extractor was insufficient for identification of adulteration ratio. The raw spectrum of ZMS and HAS adulterants extracted by FT-NIR was processed by SNV + CARS and 1d + SG + ICO respectively, the average accuracy of machine learning classification model was improved from 77.06 % to 97.58 %. Furthermore, the R2 values of the calibration and prediction set of the two quantitative prediction regression models of adulteration ratio are greater than 0.99, demonstrating excellent linearity and predictive accuracy. Overall, this study demonstrated that FT-NIR combined with multivariate algorithms provided a significant approach to addressing the growing issue of ZSS adulteration.

16.
J Fluoresc ; 2023 Dec 23.
Artigo em Inglês | MEDLINE | ID: mdl-38141145

RESUMO

Structural, optical, photoluminescence and colorimetric analyses of Gd (1-5 mol %) doped BNT ceramics synthesized by the solid-state reaction technique are reported. Structural analyses of all the samples are done by the X-ray diffraction method. It is shown that the samples have rhombohedral crystal structures with an R3C space group. The energy band gap of all the phosphors is computed from the UV-visible absorbance spectra. Photoluminescence behaviors are analyzed from the excitation along with the emission spectra of the prepared materials. The critical quenching concentration with the critical energy transfer distance is observed owing to the dipole-dipole interactions between the materials. Colorimetric analyses are carried out with the help of CIE chromaticity. Moreover, the color purity, correlated color temperature, color rendering index, and luminous efficiency of radiation values are evaluated by using the chromaticity coordinates.

17.
Zhongguo Zhong Yao Za Zhi ; 48(18): 5003-5013, 2023 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-37802842

RESUMO

In this study, CM-5 spectrophotometer and Heracles NEO ultra-fast gas-phase electronic nose were used to analyze the changes in color and odor of vinegar-processed Cyperi Rhizoma(VPCR) pieces. Various analysis methods such as DFA and partial least squares discriminant analysis(PLS-DA) were combined to identify different processing degrees and quantify the end point of processing. The results showed that with the increase in vinegar processing, the brightness parameter L~* of VPCR pieces decreased gradua-lly, while the red-green value a~* and yellow-blue value b~* initially increased and reached their maximum at 8 min of processing, followed by a gradual decrease. A discriminant model based on the color parameters L~*, a~*, and b~* was established(with a discrimination accuracy of 98.5%), which effectively differentiated different degrees of VPCR pieces. Using the electronic nose, 26 odor components were identified from VPCR samples at different degrees of vinegar processing. DFA and PLS-DA models were established for different degrees of VPCR pieces. The results showed that the 8-min processed samples were significantly distinct from other samples. Based on variable importance in projection(VIP) value greater than 1, 10 odor components, including 3-methylfuran, 2-methylbuty-raldehyde, 2-methylpropionic acid, furfural, and α-pinene, were selected as odor markers for differentiating the degrees of vinegar processing in VPCR. By combining the changes in color and the characteristic odor components, the optimal processing time for VPCR was determined to be 8 min. This study provided a scientific basis for the standardization of vinegar processing techniques for VPCR and the improvement of its quality standards and also offered new methods and ideas for the rapid identification and quality control of the end point of processing for other traditional Chinese medicine.


Assuntos
Ácido Acético , Medicamentos de Ervas Chinesas , Medicamentos de Ervas Chinesas/análise , Rizoma/química , Controle de Qualidade , Eletrônica
18.
Nanomaterials (Basel) ; 13(17)2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37686921

RESUMO

We present a dual-layer hafnium dioxide (HfO2) grating capable of full-color modulation in the visible spectrum by leveraging the magnetic dipole resonance induced by the lower-layer HfO2 grating, while the upper-layer HfO2 grating serves as a refractive index matching layer to effectively suppress high-order Mie resonances at shorter wavelengths. The HfO2/HfO2 grating exhibits a significantly larger distribution area in the CIE 1931 chromaticity diagram compared to the HfO2 grating. Furthermore, the structural color saturation closely approximates that of monochromatic light. Under varying background refractive index environments, this structure consistently exhibits high-quality structural color. However, the hue of the structural color undergoes alterations. When the polarization angle is below 20°, the saturation of the acquired structural color remains remarkably consistent. However, exceeding 20° results in a significant degradation in the quality of the structural color. This study demonstrates the promising potential for diverse applications, encompassing fields such as imaging and displays.

19.
Wilderness Environ Med ; 34(4): 610-617, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37775373

RESUMO

This Lessons from History article uses science, aviation, medicine, and mountaineering sources to describe some of the effects of hypoxia, illumination, and other environmental conditions on the eye, the central nervous system, and light and color perception. The historical perspective is augmented by an analysis of an informal observation of the altered perception of red color on a deck of playing cards while climbing Mera Peak in the Himalaya. The appearance of a grayer red color on the cards was initially attributed to the effects of hypoxia alone. Instead, analysis of cards in combination with the low incidence of protan color vision defects at altitude indicated that glare and contrast effects in the extremely bright lighting environment combined with hypoxia likely caused the perception of a grayer red. The incident provides an educational opportunity for review, analysis, and commentary about some of the complex elements that impact color vision.


Assuntos
Defeitos da Visão Cromática , Visão de Cores , Humanos , Percepção de Cores/fisiologia , Altitude , Defeitos da Visão Cromática/etiologia , Hipóxia/complicações
20.
Front Vet Sci ; 10: 1174700, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37415964

RESUMO

Bacteria- or virus-infected chicken is conventionally detected by manual observation and confirmed by a laboratory test, which may lead to late detection, significant economic loss, and threaten human health. This paper reports on the development of an innovative technique to detect bacteria- or virus-infected chickens based on the optical chromaticity of the chicken comb. The chromaticity of the infected and healthy chicken comb was extracted and analyzed with International Commission on Illumination (CIE) XYZ color space. Logistic Regression, Support Vector Machines (SVMs), K-Nearest Neighbors (KNN), and Decision Trees have been developed to detect infected chickens using the chromaticity data. Based on the X and Z chromaticity data from the chromaticity analysis, the color of the infected chicken's comb converged from red to green and yellow to blue. The development of the algorithms shows that Logistic Regression, SVM with Linear and Polynomial kernels performed the best with 95% accuracy, followed by SVM-RBF kernel, and KNN with 93% accuracy, Decision Tree with 90% accuracy, and lastly, SVM-Sigmoidal kernel with 83% accuracy. The iteration of the probability threshold parameter for Logistic Regression models has shown that the model can detect all infected chickens with 100% sensitivity and 95% accuracy at the probability threshold of 0.54. These works have shown that, despite using only the optical chromaticity of the chicken comb as the input data, the developed models (95% accuracy) have performed exceptionally well, compared to other reported results (99.469% accuracy) which utilize more sophisticated input data such as morphological and mobility features. This work has demonstrated a new feature for bacteria- or virus-infected chicken detection and contributes to the development of modern technology in agriculture applications.

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