Effects of acidified seawater on calcification, photosynthetic efficiencies and the recovery processes from strong light exposure in the coral Stylophora pistillata

2017 ◽  
Vol 38 (3) ◽  
pp. e12444 ◽  
Author(s):  
Takashi Nakamura ◽  
Akira Iguchi ◽  
Atsushi Suzuki ◽  
Kazuhiko Sakai ◽  
Yukihiro Nojiri
Keyword(s):  
Light Exposure ◽  
Strong Light ◽  
Stylophora Pistillata ◽  
Recovery Processes ◽  
Photosynthetic Efficiencies

scholarly journals Preparation and Evaluation of Intravaginal Ring Containing Drospirenone

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Ying Zhang ◽  
Chun-Xiao Li ◽  
Mei-Ying Ning ◽  
Xue-Yan Duan ◽  
Ying Liu
Keyword(s):  
Light Exposure ◽  
In Vitro Release ◽  
Tissue Level ◽  
Strong Light ◽  
Reservoir System ◽  
The Matrix ◽  
Reservoir Type ◽  
Preparation And Evaluation ◽  
Effective Contraceptive

In the present study, we investigated the feasibility of the vaginal administration of drospirenone silicone IVR. The in vitro release characteristics of matrix-type and reservoir-type IVR were compared under sink conditions in 21 days. At the same time, API excipients compatibility and preformulation study was performed by HPLC, IR, and DSC methods. Biocompatibility of reservoir system was evaluated by tolerability on tissue level in rats. It was found that, under strong light exposure, high temperature, and high humidity conditions, drospirenone and excipients had no significant interactions. The daily release of reservoir-type IVR was about 0.5 mg/d sustaining 21 days, which significantly decreased the burst effect compared with the matrix system. When drospirenone was modified by the PVPk30 in the reservoir system formulation, the daily release rate increased to 1.0 mg/d sustaining 21 days. The cumulative release of reservoir-type IVR was fitted to zero release equation. In addition, biocompatibility of drospirenone IVR system in this dosage is safe. It is feasibility feasibile to further developed for safe, convenient, and effective contraceptive drug delivery with reduced dosing interval.

scholarly journals Determination and Data Correlation of Solubility of Sofosbuvir Polymorphs in Ethyl Acetate + Toluene and Methyl tert-Butyl Ether Binary Solvents at the Temperature Range from 268.15 to 308.15 K

Crystals ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 209
Author(s):  
Wei-Jie Ji ◽  
En-Fu Wang ◽  
Ming-Hui Qi
Keyword(s):  
Solid State ◽  
Ethyl Acetate ◽  
Light Exposure ◽  
Binary Solvents ◽  
Methyl Tert Butyl Ether ◽  
Butyl Ether ◽  
Strong Light ◽  
Temperature Range ◽  
Tert Butyl ◽  
Solid State Stability

A gravimetric method was used to experimentally determine the (solid + liquid) equilibrium of sofosbuvir of crystalline forms A and B in both ethyl acetate + toluene and methyl tert-butyl ether (MTBE) + toluene binary solvents systems at atmosphere pressure. Experiments were carried out at a temperature range of 268.15−308.15 K. Results show that the solubility of sofosbuvir increases with temperature, and the solubility of form B was higher than that of form A. The modified Apelblat model, the CNIBS/Redlich–Kister model, and the combined version of Jouyban–Acree model were employed to correlate the measured solubility data, respectively. Furthermore, an examination of the solid-state stability of the two polymorphs was conducted, finding that form A and form B exhibit good solid-state stability under high temperature, high humidity, and strong light exposure conditions.

scholarly journals A Novel Botanical Combination Attenuates Light-Induced Retinal Damage through Antioxidant and Prosurvival Mechanisms

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Juntao Kan ◽  
Junrui Cheng ◽  
Jun Guo ◽  
Liang Chen ◽  
Xue Zhang ◽  
...  
Keyword(s):  
Light Exposure ◽  
Retinal Pigment Epithelial Cell ◽  
Outer Nuclear Layer ◽  
Retinal Pigment ◽  
Epithelial Cell Line ◽  
Retinal Damage ◽  
Protective Effects ◽  
Black Currant ◽  
Strong Light ◽  
Goji Berry

The prevalence of light-induced eye fatigue is increasing globally. Efficient regimen for mitigating light-induced retinal damage is becoming a compelling need for modern society. We investigated the effects of a novel combination of lutein ester, zeaxanthin, chrysanthemum, goji berry, and black currant extracts against retinal damage. In the current work, both in vitro and in vivo light-induced retinal damage models were employed. Animal study showed that under strong light exposure (15000 lx for 2 hours), the a-wave and b-wave from electroretinogram were significantly decreased. Treatment with the combination significantly restored the decrease for b-wave under high- and low-stimulus intensity. Histological analysis reported a substantial decrease in the outer nuclear layer (ONL) thickness in the model group, while the supplementation with the combination significantly improved the ONL thickness. To further explore the underlying mechanism of the protective effects, we utilized ARPE-19 retinal pigment epithelial cell line and found that strong light stimulation (2900 lx for 30 minutes) significantly increased phosphorylation of p38 and JNK and decreased HIF expression. Intriguingly, chrysanthemum, black currant extracts, lutein ester, and zeaxanthin significantly decreased the phosphorylation of p38 and JNK, while chrysanthemum, goji berry, black currant extracts, and lutein ester restored HIF expression. The botanical combination can alleviate light-induced retina damage, potentially through antioxidant and prosurvival mechanisms.

Afterimage and pupillary activity following strong light exposure

1971 ◽  
Vol 11 (3) ◽  
pp. 275-288 ◽  
Author(s):  
David A. Newsome
Keyword(s):  
Light Exposure ◽  
Strong Light

Changes of Drift Mobility in a-Si:H with Light Exposure and Doping

1987 ◽  
Vol 95 ◽  
Author(s):  
J. Takada ◽  
H. Fritzsche
Keyword(s):  
Light Intensity ◽  
Amorphous Silicon ◽  
Light Exposure ◽  
Hydrogenated Amorphous Silicon ◽  
Drift Mobility ◽  
Mobility Edge ◽  
Strong Light ◽  
Quasi Fermi Level ◽  
Multiple Trapping ◽  
Hydrogenated Amorphous

AbstractMeasurements of the drift mobility μ of photo-excited electrons in n-type hydrogenated amorphous silicon (a-Si:H) as a function of light intensity are reported. The value of μ increases as the quasi Fermi level is moved closer to the transport states in accordance with the multiple trapping theory. The drift mobility decreases with increasing doping as well as with an increase in the concentration of metastable dangling bonds defects by strong light exposures. This decrease in μ between 300 and 360K can be explained by a corresponding decrease in the microscopic mobility, by an increase in the density of tail states within 0.35eV below the electron mobility edge, or by a combination of both these effects.

The lutein epoxide cycle in higher plants: its relationships to other xanthophyll cycles and possible functions

2007 ◽  
Vol 34 (9) ◽  
pp. 759 ◽  
Author(s):  
Jose I. García-Plazaola ◽  
Shizue Matsubara ◽  
C. Barry Osmond
Keyword(s):  
Light Harvesting ◽  
Higher Plants ◽  
Protein Complexes ◽  
Light Exposure ◽  
Photosynthetic Pigment ◽  
In Vivo Studies ◽  
Photochemical Quenching ◽  
Strong Light

Several xanthophyll cycles have been described in photosynthetic organisms. Among them, only two are present in higher plants: the ubiquitous violaxanthin (V) cycle, and the taxonomically restricted lutein epoxide (Lx) cycle, whereas four cycles seem to occur in algae. Although V is synthesised through the β-branch of the carotenoid biosynthetic pathway and Lx is the product of the α-branch; both are co-located in the same sites of the photosynthetic pigment-protein complexes isolated from thylakoids. Both xanthophylls are also de-epoxidised upon light exposure by the same enzyme, violaxanthin de-epoxidase (VDE) leading to the formation of zeaxanthin (Z) and lutein (L) at comparable rates. In contrast with VDE, the reverse reaction presumably catalysed by zeaxanthin epoxidase (ZE), is much slower (or even inactive) with L than with antheraxanthin (A) or Z. Consequently many species lack Lx altogether, and although the presence of Lx shows an irregular taxonomical distribution in unrelated taxa, it has a high fidelity at family level. In those plants which accumulate Lx, variations in ZE activity in vivo mean that a complete Lx-cycle occurs in some (with Lx pools being restored overnight), whereas in others a truncated cycle is observed in which VDE converts Lx into L, but regeneration of Lx by ZE is extremely slow. Accumulation of Lx to high concentrations is found most commonly in old leaves in deeply shaded canopies, and the Lx cycle in these leaves is usually truncated. This seemingly anomalous situation presumably arises because ZE has a low but finite affinity for L, and because deeply shaded leaves are not often exposed to light intensities strong enough to activate VDE. Notably, both in vitro and in vivo studies have recently shown that accumulation of Lx can increase the light harvesting efficiency in the antennae of PSII. We propose a model for the truncated Lx cycle in strong light in which VDE converts Lx to L which then occupies sites L2 and V1 in the light-harvesting antenna complex of PSII (Lhcb), displacing V and Z. There is correlative evidence that this photoconverted L facilitates energy dissipation via non-photochemical quenching and thereby converts a highly efficient light harvesting system to an energy dissipating system with improved capacity to engage photoprotection. Operation of the α- and β-xanthophyll cycles with different L and Z epoxidation kinetics thus allows a combination of rapidly and slowly reversible modulation of light harvesting and photoprotection, with each cycle having distinct effects. Based on the patchy taxonomical distribution of Lx, we propose that the presence of Lx (and the Lx cycle) could be the result of a recurrent mutation in the epoxidase gene that increases its affinity for L, which is conserved whenever it confers an evolutionary advantage.

scholarly journals Anaerobic digestion effluent treatment using microalgae and nitrifiers in an outdoor raceway pond with fluidized carriers

2020 ◽  
Vol 82 (6) ◽  
pp. 1081-1091
Author(s):  
Shinichi Akizuki ◽  
Germán Cuevas-Rodríguez ◽  
Tatsuki Toda
Keyword(s):  
Anaerobic Digestion ◽  
Light Exposure ◽  
Light Stress ◽  
Total Suspended Solid ◽  
Suspended Solid ◽  
Effluent Treatment ◽  
Ammonium Concentration ◽  
Ammonium Oxidation ◽  
Strong Light ◽  
Raceway Pond

Abstract Combining microalgae and nitrifiers in a single photobioreactor has attracted attention as an alternative approach for conventional nitrogen removal from wastewater. However, nitrifiers are known to be sensitive to light exposure. This study demonstrated the effectiveness of using fluidized carriers to mitigate light stress in nitrifiers. An outdoor raceway pond containing microalgae and nitrifiers with fluidized carriers was used to treat two-fold diluted anaerobic digestion effluent (785 mg-N L−1 as a form of dissolved total Kjeldahl nitrogen: TKN) over 50 days. The average daily sunlight intensity reached the inhibition level of nitrifiers (423 μmol photons m−2 s−1); however, stable nitrification with a specific ammonium oxidation rate of 55 mg-N g-total suspended solid−1 day−1 was observed. TKN was mostly removed via nitrifier metabolism (ammonium oxidation and uptake: 40.1%) and partially via microalgae uptake (5.7%). Different microalgae-based processes including that of this study were compared in terms of tolerances to a high dissolved TKN concentration and strong light. Our system showed a relatively higher resistance to not only light exposure but also TKN because the nitrification process decreased the free ammonia level to less than 0.25 mg L−1, which allowed microalgae to grow despite the high ammonium concentration.

scholarly journals PHOTOPROTECTIIVE STRATEGIES OF UNICELULAR RED ALGA RHODELLA VIOLACEA DURING ACCLIMATION TO STRONG LIGHT

2020 ◽  
Vol 3 (11(80)) ◽  
pp. 31-38
Author(s):  
K. Neverov
Keyword(s):  
Fluorescence Quenching ◽  
Red Algae ◽  
Molecular Mechanisms ◽  
Light Exposure ◽  
Photosynthetic Apparatus ◽  
Water Soluble ◽  
Photochemical Quenching ◽  
Strong Light ◽  
Rhodella Violacea ◽  
Chl Fluorescence

Red algae contain in their photosynthetic machinery water-soluble antenna complexes - phycobilisomes (PBSs) attached to thylakoid membranes to transfer excitation energy to photosystems. Strong light absorbed by the PBSs triggers a fast formation of transthylakoid ΔpH that follows the non-photochemical quenching of chlorophyll (Chl) fluorescence. The ΔpH build-up seems to be essential for photoprotecting the photosynthetic apparatus in the absence of xanthophyll cycle common to higher plants. However, the photoprotective mechanisms of red algae are not studied in details yet.  We present here our research of the Chl fluorescence quenching in unicellular red algae Rhodella violacea and its correlation with the ΔpH gradient being formed. The relation of this phenomenon to photoprotection of photosystem 2 (PS 2) in the normal and high light-acclimated Rhodella cells is also examined.  Under the photoinhibitory conditions (white light of 2000-3000 μE/m2s), the ΔpH-dependent Chl fluorescence quenching was found to delay the kinetics of PS 2 photoinhibition. The uncouplers like nigericin and NH4Cl are known to break down ΔpH gradient, lead to the dissipation of Chl fluorescence quenching followed by enhancing the PS 2 photoinhibition rate. The same effect showed far-red (FR) light consuming transthylakoid ΔpH. ATPase inhibitor, DCCD, having no impact on ΔpH didn’t influence PS 2 photoinhibition as well this implies the photoprotection to be fulfilled by the proton gradient rather than by ATP synthesis.  Long-term acclimation of Rhodella cells to higher irradiances (500-1000 μE/m2s) results in a partial loss of the periphery phycoerythrin-containing subunits by PBSs. The light-acclimated cultures display a higher resistance to the photoinhibitory light than the non-acclimated ones. This could be explained by diminishing the energy transfer from the reduced PBSs to PS 2 as well as light screening by the secondary carotenoids synthesized during light exposure.  Data on low-temperature (77K) fluorescence allow to evaluate the molecular mechanisms of light-induced Chl fluorescence suppression in Rhodella cells and its recovery in darkness. 

scholarly journals SOME BEHAVIOUR PATTERNS AND DISTRIBUTION OF CASPIAN ORDINARY SPRAT SPECIES - CLUPEONELLA DELICATULA CASPIA SVETOVIDOV

2018 ◽  
pp. 27-38
Author(s):  
Sergei Vladimirovich Kanatev ◽  
Aliya Ahmetovna Aseinova ◽  
Yuriy Aleksandrovich Paritskiy ◽  
Vjacheslav Petrovich Razinkov
Keyword(s):  
Light Source ◽  
Caspian Sea ◽  
Light Field ◽  
Light Exposure ◽  
Monochromatic Light ◽  
Mnemiopsis Leidyi ◽  
Fishing Gear ◽  
The Caspian Sea ◽  
Strong Light ◽  
Study Results

The global environmental changes that occurred in the Caspian Sea in the last decade, as well as the population outbreak of Mnemiopsis leidyi invasive from the Black Sea resulted in extinction of the most important food item of endemic sprat species, which caused biological wellbeing of ordinary sprat. The data of multi-year observations obtained in the course of studying the abundance and biology of the species have been generalized in order to improve methods and fishing gear and to organize ordinary sprat fishery. The article presents study results of ordinary sprat’s behavior. The analysis has revealed that ordinary sprat is less photophilous in strong light zones, compared to anchovy sprat, and forms exploitable concentrations under the light exposure from 45 min and longer. In the light field ordinary sprat species keep away from the light source and create a second ring at a distance 0.8-2.5 m from the light bulb. The fish aggregation in the light field of the DNaT 400 lamp occurs at smaller exposures than of the SC-102 lamp. The experiment with concurrent use of two different light sources demonstrates some preference of monochromatic light collecting in its light field up to 75% fishes of the total number. The contrast of light and shade created by a light source with a partially darkened bulb changes the fish behavior and increases the density of their aggregation in the light sector near the bulb of the lamp. According to the study results, the article presents considerations concerning new fishing gear in fishing industry that allow to regulate fish species composition in the catch in the Caspian Sea with an increase in the proportion of ordinary sprat.

Sign in / Sign up

Export Citation Format

Share Document