scholarly journals Study on the Photochemical Reaction Process of 4-methyl-7-Hydroxycoumarin and Its Mechanism by Multi-Spectroscopic Technologies

2021 ◽  
Vol 2112 (1) ◽  
pp. 012023
Author(s):  
Qian Tang ◽  
Zhengping Xian ◽  
Lingjing Li ◽  
Hongyu Cao ◽  
Lihao Wang ◽  
...  
Keyword(s):  
Fluorescence Spectroscopy ◽  
Photochemical Reaction ◽  
Structural Changes ◽  
Blue Shift ◽  
Inhibitory Effect ◽  
Reaction Process ◽  
New Materials ◽  
Characteristic Peak ◽  
Other Substances ◽  
Slight Blue Shift

Abstract The photochemical reaction process of 4-methyl-7-hydroxycoumarin (7H4MC) was studied by UV-Vis spectrometer and fluorescence spectroscopy. The results have shown that the characteristic peak of the UV-Vis spectra at 323 nm of 7H4MC undergoes a significant decrease in absorbance and a slight blue shift when was illuminated; the absorbance of the absorption peak at 279 nm rises, and there is a tendency for new peaks to appear. May be, there are structural changes or new materials generation. The addition of imidazole, VC, 3-indole methanol, GSH and other substances also have different effects on the photochemical reaction of 7H4MC. Among them, only imidazole has a certain inhibitory effect on the process of its photochemical reaction.

scholarly journals Garlic Extract: Inhibition of Biochemical and Biophysical Changes in Glycated HSA

2021 ◽  
Vol 11 (22) ◽  
pp. 11028
Author(s):  
Mohd W. A. Khan ◽  
Ahmed A. Otaibi ◽  
Arwa F. M. Alhumaid ◽  
Abdulmohsen K. D. Alsukaibi ◽  
Asma K. Alshamari ◽  
...  
Keyword(s):  
Structural Changes ◽  
Therapeutic Potential ◽  
Inhibitory Effect ◽  
Significant Inhibition ◽  
Garlic Extract ◽  
Diabetic Patients ◽  
Age Related ◽  
Health Complications ◽  
Biophysical Changes

Glycation of various biomolecules contributes to structural changes and formation of several high molecular weight fluorescent and non-fluorescent, advanced glycation end products (AGEs). AGEs and glycation are involved in various health complications. Synthetic medicines, including metformin, have several adverse effects. Natural products and their derivatives are used in the treatment of various diseases due to their significant therapeutic qualities. Allium sativum (garlic) is used in traditional medicines because of its antioxidant, anti-inflammatory, and anti-diabetic properties. This study aimed to determine the anti-glycating and AGEs inhibitory activities of garlic. Biochemical and biophysical analyses were performed for in vitro incubated human serum albumin (HSA) with 0.05 M of glucose for 1, 5, and 10 weeks. Anti-glycating and AGEs inhibitory effect of garlic was investigated in glycated samples. Increased biochemical and biophysical changes were observed in glycated HSA incubated for 10 weeks (G-HSA-10W) as compared to native HSA (N-HSA) as well as glycated HSA incubated for 1 (G-HSA-1W) and 5 weeks (G-HSA-5W). Garlic extract with a concentration of ≥6.25 µg/mL exhibited significant inhibition in biophysical and biochemical changes of G-HSA-10W. Our findings demonstrated that garlic extract has the ability to inhibit biochemical and biophysical changes in HSA that occurred due to glycation. Thus, garlic extract can be used against glycation and AGE-related health complications linked with chronic diseases in diabetic patients due to its broad therapeutic potential.

EFFECTS OF SULFUR SUBSTITUTIONAL IMPURITIES ON ZnO STRUCTURE USING DENSITY FUNCTIONAL THEORY

2011 ◽  
Vol 10 (03) ◽  
pp. 381-390
Author(s):  
MANUEL ALBERTO FLORES-HIDALGO ◽  
DIANA BARRAZA-JIMÉNEZ ◽  
DANIEL GLOSSMAN-MITNIK
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Structural Changes ◽  
Theoretical Calculations ◽  
Plane Waves ◽  
Crystal Form ◽  
Functional Theory ◽  
Substitutional Impurity ◽  
Gap Energy ◽  
Other Substances

Zinc oxide ( ZnO ) electrical properties can be modified by addition of impurities or defects such as vacancies or other substances. We use sulfur ( S ) as a substitutional impurity and present a theoretical study on the characteristics of ZnO structures in its crystal form containing S in substitution of O . For theoretical calculations we used Density Functional Theory (DFT) with pseudopotentials and plane waves. ZnO in crystal form with S in substitution of O at heavy percentage was studied by analyzing properties like lattice characteristics, total energy, and gap energy. Lattice parameters a, b, c, and c/a ratio increase with the S -substituent percentage while the crystal stability decreases. Variation of gap energy shows a decreasing trend with increasing amount of substitution. In this paper, we provide a detailed data useful to identify the effects on ZnO in its crystal form when O is replaced by S that will help to predict if the structural changes on the modified ZnO structures may be suitable for applications in opto-electronics.

Controlled Synthesis of PbWO4 Crystals with Good Fluorescence Property by a Novel Duck Egg Membrane

2015 ◽  
Vol 33 ◽  
pp. 49-59
Author(s):  
Bao You Gong ◽  
Le Pan ◽  
Qing Feng Zhang ◽  
Hui Zhang ◽  
An Jian Xie ◽  
...  
Keyword(s):  
Outer Surface ◽  
Fluorescence Spectra ◽  
Room Temperature ◽  
Blue Shift ◽  
Biomimetic Synthesis ◽  
Reactant Concentration ◽  
Inner Surface ◽  
Egg Membrane ◽  
Duck Egg ◽  
Slight Blue Shift

PbWO4 crystals with different morphologies were readily induced by duck egg membrane via biomimetic synthesis at room temperature. The size and morphologies of the PbWO4 crystals could be controlled by outer or inner surface of duck egg membrane, the reactant concentration and the reaction time. The results show that spherical, flower-like and spindle-like crystals were obtained on the inner surface of membrane while rhombic, hexagon-like and chrysanthemum-like crystals were gained on the outer surface with the concentration of Pb2+ and WO42- increases. Room-temperature fluorescence spectra indicate the products on the inner surface of the duck egg membrane have a slight blue shift compared to that on the outer surface at the same condition. The PbWO4 crystals with small size obtained at a lower reactant concentration present a better fluorescence performance. The exploration of the reaction mechanism reveals that the interaction between Pb2+ ions and the proteins on the surface of duck egg membrane can make the conformation of the proteins more ordered. In general, the present synthesis route may be extended to prepare other inorganic functional micro-materials.

Prejunctional adrenergic inhibition by aggregating platelets in canine blood vessels

1985 ◽  
Vol 249 (3) ◽  
pp. H685-H689 ◽  
Author(s):  
R. R. Lorenz ◽  
P. M. Vanhoutte
Keyword(s):  
Blood Vessels ◽  
Inhibitory Effect ◽  
Adrenergic Nerve ◽  
Saphenous Veins ◽  
Other Substances ◽  
Adrenergic Nerve Endings ◽  
Adrenergic Neurotransmission ◽  
Prejunctional Inhibition ◽  
Serotonergic Antagonist ◽  
Stimulation Of

Experiments were performed to determine the effect of aggregating platelets on adrenergic neurotransmission. Rings of canine saphenous veins and left circumflex coronary arteries were incubated with [3H]norepinephrine and suspended for superfusion. Aggregating platelets and exogenous 5-hydroxytryptamine decreased the overflow of [3H]norepinephrine evoked by electrical stimulation of the adrenergic nerve endings. The reduction of transmitter overflow caused by 5-hydroxytryptamine was prevented by the serotonergic antagonist methiothepin in a concentration that did not significantly affect the release of 5-hydroxytryptamine or thromboxane B2 from the aggregating platelets. Methiothepin decreased but did not abolish the inhibitory effect of aggregating platelets on neurotransmitter overflow. These experiments demonstrate that 5-hydroxytryptamine and other substances released from aggregating platelets can exert prejunctional inhibition of adrenergic neurotransmission in isolated blood vessels.

scholarly journals Strain-dependent structure and Raman behaviours in the heavy-ion irradiated manganite at extreme low dose

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Nam Nhat Hoang ◽  
Duc Huyen Yen Pham ◽  
The Nghia Nguyen
Keyword(s):  
Density Functional ◽  
Structural Changes ◽  
Low Dose ◽  
Blue Shift ◽  
Heavy Ion ◽  
Dynamic Calculation ◽  
Functional Theory ◽  
Lattice Dynamic Calculation ◽  
Strain Dependent ◽  
Shed Light

AbstractThe microstrains in heavy-ion irradiated manganite LaMnO3 can be managed in linear response of irradiation dose, and the corresponding internal pressure up to 8 GPa can be induced by varying doses. The response of structure under stress is studied by means of Density Functional Theory and Lattice Dynamic Calculation. All obtained Raman scattering lines are discussed in details to shed light onto structural changes during ion implantation. There appears new resonance peak at around 550 cm−1, which splits from broad features in the spectra, and attributes to the anti-symmetric vibrations of O6 cages. The blue shift of this peak scales to ~2.4 cm−1 per 1 GPa of stress. Another strong feature showing considerable blue shift is seen in the vicinity of 640 cm−1 and corresponds to one of rhombohedral distortion related soft modes. A weak mode, not frequently reported, is seen at around 420 cm−1 and corresponds to translation-like motions of fixed O6 cages.

scholarly journals TFIIA induces conformational changes in TFIID via interactions with the basic repeat.

1992 ◽  
Vol 12 (11) ◽  
pp. 5189-5196 ◽  
Author(s):  
D K Lee ◽  
J DeJong ◽  
S Hashimoto ◽  
M Horikoshi ◽  
R G Roeder
Keyword(s):  
Dna Binding ◽  
Conformational Changes ◽  
Structural Changes ◽  
Inhibitory Effect ◽  
Binding Studies ◽  
Binding Interaction ◽  
Contact Points ◽  
Tata Element ◽  
N Terminus ◽  
Dna Binding Studies

DNA-binding studies with Saccharomyces cerevisiae TFIID point mutants indicated that TFIIA interacts with the basic repeat region of TFIID and induces structural changes. The latter was shown by the ability of TFIIA to compensate for TFIID point mutants defective for DNA binding. Interaction with TFIIA also rendered TFIID binding temperature independent, thus mimicking the effect of removing the nonconserved N terminus of TFIID. In addition, N-terminal truncation of the TFIID point mutants defective for DNA binding mimicked the ability of TFIIA to restore DNA binding of those mutants. Taken together, these results suggest that TFIIA enhances TFIID binding to DNA by eliminating an otherwise inhibitory effect of the nonconserved N terminus of TFIID. Furthermore, analyses of TFIID contact points on DNA and binding studies with TATA-containing oligonucleotide probes showed that TFIIA decreases the effect of sequences flanking the adenovirus major late TATA element on TFIID binding to DNA, suggesting a possible role of TFIIA in allowing TFIID to recognize a wider variety of promoters.

Photoinduced Structural Changes as the Factor Influencing the Direction of the Photochemical Reaction in the Crystal

2017 ◽  
Vol 17 (3) ◽  
pp. 1347-1352 ◽  
Author(s):  
Krzysztof Konieczny ◽  
Julia Bąkowicz ◽  
Renata Siedlecka ◽  
Tomasz Galica ◽  
Ilona Turowska-Tyrk
Keyword(s):  
Photochemical Reaction ◽  
Structural Changes

scholarly journals THE INHIBITORY EFFECT OF ACRIDINE ON THE SPOROGONY OF A COCCIDIUM (EIMERIA STIEDÆ)

1924 ◽  
Vol 40 (2) ◽  
pp. 263-267 ◽  
Author(s):  
Paul A. Lewis
Keyword(s):  
Inhibitory Effect ◽  
Protozoan Parasites ◽  
Other Substances ◽  
Acridine Hydrochloride ◽  
Further Development ◽  
Eimeria Stiedae

The development or ripening of the oocyst of the coccidium of the rabbit is prevented by acridine hydrochloride provided that the cysts are exposed to the action of the chemical before development has started. After sporoblasts are formed acridine does not prevent further development. Many other substances, some of them known to be active against certain protozoan parasites, have no influence on the ripening of the oocysts of the coccidium.

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