Ambient Fluorescent Light Research Articles

Mechanism of the Reaction of Olefins with Nitrous Anhydride (O═N-O-N═O) to Form 1,2-Oxazetes.

The mechanistic pathway for the formation of 1,2-oxazetes by reaction of olefins with nitrous anhydride has been clarified. The initial reaction intermediate, a β-nitroso nitrite ester that is sensitive to light, undergoes O-NO fission to form a β-nitroso alkoxy radical, even with ambient fluorescent lighting but much faster with blue light irradiation. The oxygen of the alkoxy radical subsequently adds to the adjacent nitroso group to generate a cyclic four-membered nitrosyl radical. The 1,2-oxazete is then produced by elimination to generate the C═N bond. No 1,2-oxazete formation occurs in the dark.

Bright environmental light improves the sleepiness of nightshift ICU nurses

BackgroundShift work can disturb circadian homeostasis and result in fatigue, excessive sleepiness, and reduced quality of life. Light therapy has been shown to impart positive effects in night shift workers. We sought to determine whether or not prolonged exposure to bright light during a night shift reduces sleepiness and enhances psychomotor performance among ICU nurses.MethodsThis is a single-center randomized, crossover clinical trial at a surgical trauma ICU. ICU nurses working a night shift were exposed to a 10-h period of high illuminance (1500–2000 lx) white light compared to standard ambient fluorescent lighting of the hospital. They then completed the Stanford Sleepiness Scale and the Psychomotor Vigilance Test. The primary and secondary endpoints were analyzed using the paired t test. A p value <0.05 was considered significant.ResultsA total of 43 matched pairs completed both lighting exposures and were analyzed. When exposed to high illuminance lighting subjects experienced reduced sleepiness scores on the Stanford Sleepiness Scale than when exposed to standard hospital lighting: mean (sem) 2.6 (0.2) vs. 3.0 (0.2), p = 0.03. However, they committed more psychomotor errors: 2.3 (0.2) vs. 1.7 (0.2), p = 0.03.ConclusionsA bright lighting environment for ICU nurses working the night shift reduces sleepiness but increases the number of psychomotor errors.Trial registrationClinicalTrials.gov, NCT03331822. Retrospectively registered on 6 November 2017.

EVALUATING THE CLINICAL AND PHYSIOLOGICAL EFFECTS OF LONG-TERM ULTRAVIOLET B RADIATION ON RABBITS (ORYCTOLAGUS CUNICULUS)

Vitamin D is an essential hormone in vertebrates. Most animals acquire this hormone through their diet and/or exposure to ultraviolet B (UVB) radiation. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on rabbits (Oryctolagus cuniculus) and to evaluate the long-term safety of artificial UVB light supplementation over a 6-month period. Twelve New Zealand white rabbits were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received ambient fluorescent light with no UVB supplementation for 12 hours daily. All animals were offered the same diet and housed under the same conditions. Blood samples were collected every 3 weeks over 6 months to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations were performed at the beginning of the study and every 2 months thereafter. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly (P = 0.003) between animals provided supplemental UVB radiation (83.12 ± 22.44 nmol/L) and those not provided UVB radiation (39.33 ± 26.07 nmol/L). There were no apparent negative clinical or pathologic side effects noted between the groups. This study found that exposing rabbits to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, which was sustainable over time.

Study on the Photoinduced Nitric‐Oxide‐Releasing Ability of 4‐Alkoxy Furoxans

AbstractNitric oxide (NO) has a range of biological activities in living systems. Because NO is a gaseous and short‐lived molecule, the development of methods to enable a temporally and spatially resolved NO supply has been a challenging task. Herein, 3‐aryl‐4‐alkoxy furoxan is revealed as a potent photoinduced NO donor. Whilst negligible levels of NO release were observed under ambient fluorescent light, a significant amount of NO was released under UV irradiation (λ=300–400 nm). A thiol mediator that contains a pendant amino group was found to be indispensable for NO release from aryl alkoxy furoxans. Analysis of the NO‐releasing mechanism of aryl alkoxy furoxan revealed that the main co‐product was the corresponding aryl nitrile, which was derived from fragmentation of the furoxan ring. Based on these results, we have proposed a plausible mechanism for photoinduced NO release, in which the key steps are nucleophilic attack of the thiol at the 3‐position of the furoxan, thereby leading to fragmentation of the furoxan ring, and the formation of a tetrahydrothiazole that contains a C‐nitroso group. A comparison of fluorofuroxan and alkoxy furoxan is also discussed.

赤色光がミカンキイロアザミウマの植物に対する行動に及ぼす影響評価

We used light-emitting diodes (LEDs) to examine the effect of red light on the behavioral responses of melon thrips, Flankliniella occidentalis. We allowed adults to choose between tomato plants exposed and unexposed to red LED light under ambient fluorescent lighting conditions. Thrips were less attracted to plants exposed to red LED light during 8- as well as 24-h exposure.

Effects of Artificial Ultraviolet Radiation on Serum 25-Hydroxyvitamin D3 Concentrations in Captive Guinea Pigs (Cavia Porcellus)

Under natural conditions, guinea pigs (Cavia porcellus) are exposed to ultraviolet B (UVB) radiation. Although the role of UVB radiation in the photobiochemical synthesis of vitamin D is well documented in humans and other vertebrates, to date it has not been evaluated in guinea pigs. The purpose of this study was to determine whether artificial UVB radiation has an effect on serum 25-hydroxyvitamin D3 levels in guinea pigs. A total of 12 juvenile guinea pigs were randomly assigned to 1 of 2 treatment groups: Group A was exposed to 12 hours of artificial UVB radiation (290 to 315nm) daily and Group B received ambient fluorescent light with no UVB supplementation for 12 hours/day. Blood samples were collected under anesthesia on days 0 and 18 to measure serum 25-hydroxyvitamin D3 levels. Animals in both groups were offered the same diet. There was a significant difference in 25-hydroxyvitamin D3 concentrations over time (F = 399.3, P = 0.0001) and by group (F = 63.6, P = 0.0001), with an average increase between sampling periods of 56.5nmol/L in Group A (UVB) and 2.33nmol/L in Group B (no UVB). This study represents the first attempt to measure the effect of UVB radiation on 25-hydroxyvitamin D3 levels in guinea pigs. In vertebrates, vitamin D is an essential hormone that regulates many physiologic functions within the body. These preliminary findings confirm that guinea pigs can obtain vitamin D via photobiochemical synthesis, but additional work is needed to determine the physiologic importance of this finding and potential risks associated with UVB exposure in these rodents.

Evaluating the clinical and physiological effects of long term ultraviolet B radiation on guinea pigs (Cavia porcellus).

Vitamin D is an important hormone in vertebrates. Most animals acquire this hormone through their diet, secondary to exposure to ultraviolet B (UVB) radiation, or a combination thereof. The objectives for this research were to evaluate the clinical and physiologic effects of artificial UVB light supplementation on guinea pigs (Cavia porcellus) and to evaluate the long-term safety of artificial UVB light supplementation over the course of six months. Twelve juvenile acromelanic Hartley guinea pigs were randomly assigned to one of two treatment groups: Group A was exposed to 12 hours of artificial UVB radiation daily and Group B received only ambient fluorescent light for 12 hours daily. Animals in both groups were offered the same diet and housed under the same conditions. Blood samples were collected every three weeks to measure blood chemistry values, parathyroid hormone, ionized calcium, and serum 25-hydroxyvitamin D3 (25-OHD3) levels. Serial ophthalmologic examinations, computed tomography scans, and dual energy x-ray absorptiometry scans were performed during the course of the study. At the end of the study the animals were euthanized and necropsied. Mean ± SD serum 25-OHD3 concentrations differed significantly in the guinea pigs (p<0.0001) between the UVB supplementation group (101.49±21.81 nmol/L) and the control group (36.33±24.42 nmol/L). An increased corneal thickness in both eyes was also found in the UVB supplementation compared to the control group (right eye [OD]: p<0.0001; left eye [OS]: p<0.0001). There were no apparent negative clinical or pathologic side effects noted between the groups. This study found that exposing guinea pigs to UVB radiation long term significantly increased their circulating serum 25-OHD3 levels, and that this increase was sustainable over time. Providing guinea pigs exposure to UVB may be an important husbandry consideration that is not currently recommended.

Diagnostic Challenge

Under natural conditions, guinea pigs (Cavia porcellus) are exposed to ultraviolet B (UVB) radiation. Although the role of UVB radiation in the photobiochemical synthesis of vitamin D is well documented in humans and other vertebrates, to date it has not been evaluated in guinea pigs. The purpose of this study was to determine whether artificial UVB radiation has an effect on serum 25-hydroxyvitamin D3 levels in guinea pigs. A total of 12 juvenile guinea pigs were randomly assigned to 1 of 2 treatment groups: Group A was exposed to 12 hours of artificial UVB radiation (290 to 315 nm) daily and Group B received ambient fluorescent light with no UVB supplementation for 12 hours/day. Blood samples were collected under anesthesia on days 0 and 18 to measure serum 25-hydroxyvitamin D3 levels. Animals in both groups were offered the same diet. There was a significant difference in 25-hydroxyvitamin D3 concentrations over time (F = 399.3, P = 0.0001) and by group (F = 63.6, P = 0.0001), with an average increase between sampling periods of 56.5 nmol/L in Group A (UVB) and 2.33 nmol/L in Group B (no UVB). This study represents the first attempt to measure the effect of UVB radiation on 25-hydroxyvitamin D3 levels in guinea pigs. In vertebrates, vitamin D is an essential hormone that regulates many physiologic functions within the body. These preliminary findings confirm that guinea pigs can obtain vitamin D via photobiochemical synthesis, but additional work is needed to determine the physiologic importance of this finding and potential risks associated with UVB exposure in these rodents.

Stability study of carboplatin infusion solutions in 0.9% sodium chloride in polyvinyl chloride bags.

Carboplatin is a platinum-containing compound with efficacy against various malignancies. The physico-chemical stability of carboplatin in dextrose 5% water (D5W) has been thoroughly studied; however, there is a paucity of stability data in clinically relevant 0.9% sodium chloride infusion solutions. The manufacturer's limited stability data in sodium chloride solutions hampers the flexibility of carboplatin usage in oncology patients. Hence, the purpose of this study is to determine the physical and chemical stability of carboplatin-sodium chloride intravenous solutions under different storage conditions. The physico-chemical stability of 0.5 mg/mL, 2.0 mg/mL, and 4.0 mg/mL carboplatin-sodium chloride solutions prepared in polyvinyl chloride bags was determined following storage at room temperature under ambient fluorescent light and under refrigeration in the dark. Concentrations of carboplatin were measured at predetermined time points up to seven days using a stability-indicating high-performance liquid chromatography method. All tested solutions were found physically stable for at least seven days. The greatest chemical stability was observed under refrigerated storage conditions. At 4℃, all tested solutions were found chemically stable for at least seven days, with nominal losses of ≤6%. Following storage at room temperature exposed to normal fluorescent light, the chemical stability of 0.5 mg/mL, 2.0 mg/mL, and 4.0 mg/mL solutions was three days, five days, and seven days, respectively. The extended physico-chemical stability of carboplatin prepared in sodium chloride reported herein permits advance preparation of these admixtures, facilitating pharmacy utility and operations. Since no antibacterial preservative is contained within these carboplatin solutions, we recommend storage, when prepared under specified aseptic conditions, no greater than 24 h at room temperature or three days under refrigeration.

Optical fibre probe NIR Raman measurements in ambient light and in combination with a tactile resonance sensor for possible cancer detection

First measurements on a combined instrument with a thin fibre optic Raman probe mounted inside a hollow tactile resonance sensor have been performed in ambient light on porcine tissue. The ambient fluorescent light was removed successfully from the spectra. The stiffness and the biomolecular composition of the tissue were analysed.

Stability of norepinephrine solutions in normal saline and 5% dextrose in water.

Most previous stability studies for norepinephrine have reported the percentage of drug remaining in IV solutions after only 24 h. No previously published study has evaluated the effect of light on the stability of this drug. To evaluate the stability of norepinephrine (64 mg/L) in either normal saline (NS; 0.9% sodium chloride) or 5% dextrose in water (D5W) with storage at either 4°C or room temperature (23°C) in polyvinyl chloride (PVC) bags exposed to or protected from normal room lighting for 2 months. Thirty-two PVC bags were prepared, each containing norepinephrine at 64 mg/L; half of the bags had normal saline as the diluent and the other half had D5W. The bags were stored at either 4°C or room temperature (23°C), with protection from or exposure to ambient fluorescent room light. Overall, there were 4 bags for each combination of diluent, temperature, and light condition. The concentration of norepinephrine in each bag was determined by a validated, stability-indicating liquid chromatographic method on study days 0, 1, 2, 3, 4, 8, 9, 10, 11, 14, 18, 21, 23, 25, 28, 30, 36, 42, and 61. Analysis of variance revealed differences in percentage remaining as a function of study day (p < 0.001) and light conditions (p < 0.001), but not diluent (p = 0.06) or storage temperature (p > 0.99). Solutions of norepinephrine 64 mg/L in NS or D5W can be stored in PVC bags at 4°C for up to 61 days with protection from light. This expiry date allows for up to 24 h storage at 23°C. Solutions that are not protected from light will retain only 90% of the initial concentration after storage for 39 days at 4°C. This storage period could include up to 24 h at room temperature, without protection from light.

Stability of Ziprasidone Mesylate in an Extemporaneously Compounded Oral Solution

To formulate a liquid preparation of ziprasidone in a convenient concentration to allow dosing of less than 20 mg and of sufficient chemical and physical stability to enable an entire prescription or course of treatment to be prepared in a single batch. Geodon for injection (ziprasidone mesylate), 20 mg/mL, was diluted to 2.5 mg/mL in a commercially available sugar-free and alcohol-free, flavored syrup and stored at room temperature under ambient fluorescent light illumination, at room temperature in darkness, and under refrigeration. The ziprasidone content was measured in samples at various time intervals using a stability-indicating high-performance liquid chromatographic method. When refrigerated, the ziprasidone syrup that was compounded in a commercially available, sugar-free and alcohol-free vehicle maintained at least 90% of stated potency for at least 6 weeks. Samples stored under other conditions were less stable, underscoring the manufacturer's labeling regarding refrigerated storage of the reconstituted injection. The findings suggest that chemical and physical stability are maintained for 2 weeks under refrigeration, allowing the convenience of compounding for the long-term needs of a particular patient, rather than daily compounding. The only storage condition we recommend is refrigeration at 5°C.

Preformulation Stability of trans-Resveratrol and trans-Resveratrol Glucoside (Piceid)

Resveratrol and resveratrol glucoside (piceid) were evaluated in a preformulation stability study. An HPLC assay was used for the analysis of stressed/reference samples. Samples of solid, crystalline material were held under the following conditions: 40 degrees C/75% RH (both open and protected), ambient fluorescent light (open), 70 degrees C (open), and exposed using a light cabinet to achieve ICH conditions for UV/fluorescent light. Both compounds were found to be stable out to 3 months for both accelerated and ambient conditions with negligible degradation. Exposure to UV and fluorescent light under ICH conditions did not significantly degrade the solid materials for UV exposure at 3 times the ICH limit and for fluorescent light exposure at 1 times the ICH limit. The results presented demonstrate crystalline resveratrol and piceid are stable solids. No evidence of oxidation of either material by atmospheric oxidants was seen. The data reported may help to clarify widely held beliefs that resveratrol is unstable and extremely sensitive to oxidation/degradation.

Formation of Carotenoid Neutral Radicals in Photosystem II

beta-Carotene radicals produced in the hexagonal pores of the molecular sieve Cu(II)-MCM-41 were studied by ENDOR and visible/near-IR spectroscopies. ENDOR studies showed that neutral radicals of beta-carotene were produced in humid air under ambient fluorescent light. The maximum absorption wavelengths of the neutral radicals were measured and were additionally predicted by using time-dependent density functional theory (TD-DFT) calculations. An absorption peak at 750 nm, assigned to the neutral radical with a proton loss from the 4(4') position of the beta-carotene radical cation in Cu(II)-MCM-41, was also observed in photosystem II (PS II) samples using near-IR spectroscopy after illumination at 20 K. This peak was previously unassigned in PS II samples. The intensity of the absorption peak at 750 nm relative to the absorption of chlorophyll radical cations and beta-carotene radical cations increased with increasing pH of the PS II sample, providing further evidence that the absorption peak is due to the deprotonation of the beta-carotene radical cation. Based on a consideration of possible proton acceptors that are adjacent to beta-carotene molecules in photosystem II, as modeled in the X-ray crystal structure of Guskov et al. Nat. Struct. Mol. Biol. 2009, 16, 334-342, an electron-transfer pathway from a beta-carotene molecule with an adjacent proton acceptor to P680*+ is proposed.

Photosensitized Tetrahydropyran Transfer

THP ethers were formed cleanly during photolysis of 3,4-dihydro-2 H-pyran, an alcohol, and catalytic 1,5-dichloro-9,10-anthraquinone with use of visible light. The reaction could be conducted under ambient fluorescent lighting or with sunlight as well as in a Rayonet reactor. The scope and mechanism are discussed.

One generation of n-3 polyunsaturated fatty acid deprivation increases depression and aggression test scores in rats

Male rat pups at weaning (21 days of age) were subjected to a diet deficient or adequate in n-3 polyunsaturated fatty acids (n-3 PUFAs) for 15 weeks. Performance on tests of locomotor activity, depression, and aggression was measured in that order during the ensuing 3 weeks, after which brain lipid composition was determined. In the n-3 PUFA-deprived rats, compared with n-3 PUFA-adequate rats, docosahexaenoic acid (22:6n-3) in brain phospholipid was reduced by 36% and docosapentaenoic acid (22:5n-6) was elevated by 90%, whereas brain phospholipid concentrations were unchanged. N-3 PUFA-deprived rats had a significantly increased (P = 0.03) score on the Porsolt forced-swim test for depression, and increased blocking time (P = 0.03) and blocking number (P = 0.04) scores (uncorrected for multiple comparisons) on the isolation-induced resident-intruder test for aggression. Large effect sizes (d > 0.8) were found on the depression score and on the blocking time score of the aggression test. Scores on the open-field test for locomotor activity did not differ significantly between groups, and had only small to medium effect sizes. This single-generational n-3 PUFA-deprived rat model, which demonstrated significant changes in brain lipid composition and in test scores for depression and aggression, may be useful for elucidating the contribution of disturbed brain PUFA metabolism to human depression, aggression, and bipolar disorder.

Surface functionalization of cellulose fibers with titanium dioxide nanoparticles and their combined bactericidal activities

A well-adherent surface of titanium oxide nanoparticles was produced on cellulose fibers at low temperature from an aqueous titania sol that was obtained via hydrolysis and condensation reactions of titanium isopropoxide in water. SEM investigations of the formed titania films revealed a semi-spherical particle morphology with grain size about 10 nm in diameter. The coated substrates showed substantial bactericidal properties under UV radiation, ambient fluorescent white light and dark conditions. The possible mechanisms for the antibacterial activity are discussed. The stability of the titania coatings was investigated by comparing the UV transmission profiles of coated fibers before and after repeated washing.

Photocatalytic Transformation of 2,4,5-Trichlorophenol on TiO2 under Sub-Band-Gap Illumination

The adsorptive behavior of TiO2 under various illumination conditions was investigated. In the dark, Degussa P25, which contains both the anatase and rutile phases of TiO2, adsorbed significantly greater amounts of 2,4,5-trichlorophenol (TCP) than either pure anatase or pure rutile. Results in the literature and in our laboratory that appeared to indicate “photoenhanced adsorption” under ambient fluorescent lighting on P25 and anatase are in fact due to the photoreaction of TCP. On pure-phase anatase, all reactions are due to trace ultra-band-gap energy light present in the fluorescent lighting. On P25, however, reaction also occurs at sub-band-gap energies. TCP forms a charge-transfer complex with P25 that is activated by light wavelengths as long as 520 nm. The trichlorophenoxyl radicals resulting from charge-transfer couple with each other to form a suite of polyaromatic chlorinated products with detected masses as high as 1200 D. These products are not formed under UV irradiation and in fact are destr...

Stability and compatibility of tirofiban hydrochloride during simulated Y-site administration with other drugs.

The stability and compatibility of tirofiban hydrochloride injection during simulated Y-site administration with various other drugs were studied. Tirofiban hydrochloride, dobutamine, epinephrine hydrochloride, furosemide, midazolam hydrochloride, and propranolol hydrochloride injections were each prepared from their respective concentrates in both 0.9% sodium chloride injection and 5% dextrose injection at both the minimum and maximum concentrations normally administered. The high-concentration solutions of midazolam hydrochloride and furosemide were used as is. Morphine sulfate was diluted in 5% dextrose injection only. Nitroglycerin premixed infusions, atropine sulfate injection, and diazepam injection were used as is. Tirofiban hydrochloride solutions were combined 1:1 with each of the secondary drug solutions in separate glass containers. Samples were stored for four hours at room temperature under ambient fluorescent light and were assayed for drug content and degradation by high-performance liquid chromatography and for pH, appearance, and turbidity. All mixtures except those containing diazepam remained clear and colorless, with no visual or turbidimetric indication of physical instability. Mixing of tirofiban hydrochloride and diazepam solutions resulted in immediate precipitation. all remaining mixtures remained clear. There was no significant loss of any of the drugs tested, no increase in known degradation products, and no appearance of unknown drug-related peaks. The pH of all test solutions remained constant. Tirofiban hydrochloride injection 0.05 mg/mL was stable for at least four hours when combined 1:1 in glass containers with atropine sulfate, dobutamine, epinephrine hydrochloride, furosemide, midazolam hydrochloride, morphine sulfate, nitroglycerin, and propranolol hydrochloride at the concentrations studied. Tirofiban hydrochloride was incompatible with diazepam.

Compatibility of tirofiban HCl with dopamine HCl, famotidine, sodium heparin, lidocaine HCl and potassium chloride during simulated Y-site administration.

To study the compatibility of tirofiban HCl injection 0-05 mg/ml with dopamine HCl, famotidine, sodium heparin, lidocaine HCl and potassium chloride infusion solutions during simulated Y-site administration. Tirofiban HCl, dopamine HCl, famotidine, lidocaine HCl and potassium chloride infusions were each prepared from their respective concentrates as per current clinical preparation instructions in both 0.9% sodium chloride and 5% dextrose solutions at both the minimum and maximum concentrations normally administered. Sodium heparin premixed infusion solutions in 5% dextrose and 0-45% sodium chloride were used as-is. Tirofiban HCl solutions were combined 1:1 (simulated Y-site administration) with the dopamine HCl, famotidine, sodium heparin, lidocaine HCl and potassium chloride solutions in separate glass containers and polyvinylchloride Y-site infusion lines. Samples were held for 4 h at room temperature under ambient fluorescent light and were assayed for changes in drug content, degradation, pH, appearance and turbidity. Activity of sodium heparin solutions was measured using an aPTT coagulation assay. All mixtures remained clear and colourless with no visual indication of instability, i.e. precipitation. Clarity of solutions was confirmed by turbidometric analysis. There was no significant loss of drug, increase in known degradates, or appearance of unknown drug-related peaks as determined by HPLC. The activity of heparin in heparin-containing solutions remained unchanged. The pH of all test-solutions remained constant. Tirofiban HCl injection 0.05 mg/ml can be co-infused by Y-site administration with dopamine HCl, famotidine, sodium heparin, lidocaine HCl and potassium chloride injection solutions.