Blue Color Change Research Articles

Rapid Cyanide Detection Using the Cyantesmo® Kit

Sources of cyanide exposure are many, including combustion of plastic and vinyl, such as in a house fire, laboratory or industrial exposures including exposure in the electroplating industry both of printed circuit boards and in jewelry work. Rapid and definitive diagnosis of cyanide poisoning is unavailable in the emergency department setting. It is desirable to make a definitive diagnosis in order to prevent potential complications of empiric treatment of presumptive cyanide poisoning from the cyanide antidote kit currently approved by the US Food and Drug Administration (FDA). We investigated a technique to detect cyanide currently utilized by water treatment facilities to determine if it can be applied to rapidly detect concentrations of cyanide in the clinically important range. Varying standardized dilutions of KCN ranging from 0.25 microg/mL to 30 microg/mL were acidified with a drop of sulphuric acid in a closed system under a ventilation hood. Cyantesmo test strips were placed into the test tubes above the fluid level where liberated HCN gas interacted with the test strip to effect a color change. Color changes were compared to negative controls and to each other. The test strips demonstrated an incrementally increasing deep blue color change over a progressively longer portion of the test strip in less than 5 minutes for each concentration of KCN including 1, 3, 10, and 30 microg/mL. The concentrations of 0.25, 0.5, and 0.75 required more than 2 hours to begin demonstration of any color change. The Cyantesmo test strips accurately and rapidly detected, in a semi-quantifiable manner, concentrations of CN greater than 1 microg/mL contained in each test sample. Future work to validate this test in blood and in clinical specimens is planned.

The laser-induced blue state of bacteriorhodopsin: mechanistic and color regulatory roles of protein-protein interactions, protein-lipid interactions, and metal ions.

In this paper we characterize the mechanistic roles of the crystalline purple membrane (PM) lattice, the earliest bacteriorhodopsin (BR) photocycle intermediates, and divalent cations in the conversion of PM to laser-induced blue membrane (LIBM; lambda(max)= 605 nm) upon irradiation with intense 532 nm pulses by contrasting the photoconversion of PM with that of monomeric BR solubilized in reduced Triton X-100 detergent. Monomeric BR forms a previously unreported colorless monomer photoproduct which lacks a chromophore band in the visible region but manifests a new band centered near 360 nm similar to the 360 nm band in LIBM. The 360 nm band in both LIBM and colorless monomer originates from a Schiff base-reduced retinyl chromophore which remains covalently linked to bacterioopsin. Both the PM-->LIBM and monomer-->colorless monomer photoconversions are mediated by similar biphotonic mechanisms, indicating that the photochemistry is localized within single BR monomers and is not influenced by BR-BR interactions. The excessively large two-photon absorptivities (> or =10(6) cm(4) s molecule(-1) photon(-1)) of these photoconversions, the temporal and spectral characteristics of pulses which generate LIBM in high yield, and an action spectrum for the PM-->LIBM photoconversion all indicate that the PM-->LIBM and Mon-->CMon photoconversions are both mediated by a sequential biphotonic mechanism in which is the intermediate which absorbs the second photon. The purple-->blue color change results from subsequent conformational perturbations of the PM lattice which induce the removal of Ca(2+) and Mg(2+) ions from the PM surface.

Symptoms of Raynaud’s Phenomenon in an Inner-City African-American Community: Prevalence and Self-Reported Cardiovascular Comorbidity

The objective of this study was to determine the prevalence of symptoms and the morbidity associated with Raynaud’s phenomenon (RP) among African Americans. A total of 2196 randomly selected residents of an inner-city community, in Baltimore, completed a health-assessment survey. Symptoms of RP consisted of cold sensitivity plus cold-induced white or blue digital color change. One third ( n = 703) reported cold sensitivity and 14% ( n = 308) reported digital color change; 84 residents with symptoms of RP were identified, yielding an overall prevalence rate of 3.8% (95% confidence interval [CI] 3.0–4.6). RP was associated with poor or fair health status (odds ratio [OR] = 1.82, CI 1.18–2.81), heart disease (OR = 2.32, CI 1.39–3.87), and stroke (OR = 2.20, CI 1.17–4.15), after adjustment for age, gender, and physician-diagnosed arthritis. The prevalence of symptoms of RP in this African-American community is comparable to published reports from other populations. These community-based data suggest that identification of RP among African Americans should raise consideration of possible comorbidity, particularly cardiovascular disease.

Prevalence of Raynaud phenomenon in the general population: A preliminary study by questionnaire

A short questionnaire inquiring about cold sensitivity of the fingers was administered to 1752 randomly selected subjects in a probability sample drawn from the adult population of the state of South Carolina. The overall prevalence of reported cold sensitivity was approximately 10% and showed no sex or race difference. A female preponderance was revealed only after subjects exposed to vibrating tools were excluded, and then only in the white group. Estimates of the prevalence of Raynaud phenomenon were obtained using the following criteria: (1) cold sensitive subjects reporting white and/or blue color changes: 4.6%; (2) cold sensitivity leading to medical consultation: 3.0%; (3) combination of the two criteria above: 1.9%.

Structural studies on the glycolato, lactato, and mandelato solid complexes of some bivalent iron series metals

Electronic absorption spectra, infrared vibrational spectra, and X-ray powder patterns have been measured for anhydrous bis(glycolato), bis(lactato), and bis(mandelato) complexes of bivalent Mn, Co, Ni, Cu, and Zn. Despite indications of considerable differences in crystal structure, the visible spectra of all complexes are quite similar to those of analogous hexaaquo complexes. A ligand field analysis yields as new data a spectrochemical series for the ligands[Formula: see text]in agreement with the order of proposed metal–oxygen stretch frequencies and previously measured acid pK's of the ligands.An interesting red to blue color change, observed in all cobalt complexes on heating, is shown to be reversible in the glycolate. A tentative model proposed for the complex appears to be consistent with all the experimental data including the color change phenomena.

Direct Titrimetric Determination of Aromatic Quaternary Ammonium Salts and Long Chain Aliphatic Sulfates and Sulfonates

Aromatic quaternary ammonium salts and long chain aliphatic sulfates and sulfonates can be assayed by a rapid, single phase aqueous titration. Sodium tetraphenylboron serves as a direct standard in the assay of the quaternaries and benzalkonium chloride as the tirrant for anionic detergents. Bromophenol blue indicator gives a purple to blue color change when the anionic substances are titrated in strongly alkaline solution. The results of this method show excellent agreement with the standard chloroform extraction titration.

Reaction to Differentiate Vitamin A from Carotene by Means of Antimony Trichloride.

SummaryAntimony trichloride may be used effectively as a reagent to differentiate vitamin A from carotene. In chloroform solution antimony trichloride and carotene interact with the formation of a blue color, which persists after heating on the water-bath at 60° C. Under similar conditions antimony trichloride and vitamin A-bearing oils develop at room temperature a blue color. On the application of heat the blue color changes to rose, violet-red or wine-red, depending upon the concentration of the vitamin.Pyrocatechin, which Rosenthal and Erdelyi employed along with the antimony trichloride reagent to differentiate vitamin A from carotene, is not only needless, but it actually inhibits the formation of the blue color with carotene and of the blue color with oils rich in vitamin A at room temperature and of the rose or violet-red after heating. Aged solutions of pyrocatechol exert even greater inhibitory powers than fresh solutions.

Heteroploidy and Somatic Variation in the Dutch Flowering Bulbs

The following is a summary of somatic variations in hyacinths, tulips and narcissi. A. Somatic variation without change of chromosome number. (1) Somatic variation of flower coloration. In hyacinths: heteroploid varieties without change of chromosome number produce bud variations in which the anthocyanin appears in the epidermis instead of in the subepidermis. The blue color changes into light violet. In tulips: carotinoids as well as anthocyanin act a part in somatic variation. Moreover, sectors are found in which form and color are different from the mother variety. In narcissi: changes of the color of the chromoplasts take place by somatic variation. (2) Somatic variation of form. In hyacinths: somatic variations of triploid varieties occur in which one organ or all the organs of the plant are much elongated. In tulips: besides parrot forms very primitive shaped flowers appear. In narcissi: splitting of the corona by somatic variation and phenomena connected with it occur. B. Somatic variation with cha...