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2022 ◽  
Author(s):  
R. El-Mallawany ◽  
Weam aboutaleb ◽  
M.A. Naeem ◽  
S.M. Kotb ◽  
M.E. Krar ◽  
...  

Abstract Borotellurite glasses with a composition [(60-X)TeO2-(20+X)B2O3-10Li2O-10Bi2O3] where x= 5-20 in steps of 5 mol% have been synthesized. Glass density, molar volume, oxygen packing density, and many other physical parameters were measured. UV-spectra in the wave length range (200-800) nm have been measured for the whole glass series. The optical energy band gap Eopt , refractive index, and optical basicity were measured. The mass absorption coefficients (μm) are determined experimentally by the HPGe detector and compared with the theoretical values obtained by XCOM program and MCNP5 simulation code within (0.121–1.408) MeV photon energy range. Half value layer (HVL), effective atomic number and electron density (Zeff and Neff), and macroscopic removal cross-section (∑R) were evaluated. The sample [55TeO2 – 25B2O3 – 10Bi2O3 – 10Li2O] possess the highest values of (μm = 1.192 ± 0.033 cm2/g, Zeff = 56.12 e/atom and ∑ R = 0.101499 cm-1) at energy 121 keV also lower values of (HVL = 0.121 cm, TVL = 0.1 cm and MFP = 0.174 cm) at photon energy 121 keV, therefore this sample considered the best gamma ray shielding material among the prepared glasses.


2022 ◽  
Vol 67 (4) ◽  
pp. 97-105
Author(s):  
Rukhsana Ghaffar ◽  
Manzoor Ahmad ◽  
Haroon Khan ◽  
Nausheen Nazir ◽  
Nuzat Sultana ◽  
...  

Traditionally, Viola serpens has been used in the treatment of several human disorders including liver diseases without any scientific evidence. As the current therapies are not very effective and face challenges of unwanted effects and patient compliance, therefore more effective and safe agents are highly needed. The current study aimed to evaluate the hepatoprotective potential of the crude extract and subsequent fractions of the whole plant in the in-vivo model using various hematological and histopathological parameters followed by an HPLC study for the identification of phenolic compounds. Rabbits (1000-1200 g) were used in the study. Paracetamol (2g) was used to induce hepatotoxicity in experimental rabbits. The plant extract was used in two doses (150 and 300 mg/kg body weights) for eight days. The hematological parameters AST, ALT and ALP values were determined along with the histopathology of the liver. Phenolic compounds were identified by high-performance liquid chromatography (HPLC) Agilent-1260 infinity from their retention time, UV spectra and available standards while quantification was done taking the percent peak area. The doses 150 and 300 mg/kg body weight seemed to be more effective. The hematological values and the histopathological slides show the hepatoprotective effect of the plant. Regeneration indicated the presence of nuclei, nuclear cleaning, prominent nucleoli, RBC’s, central veins and plates of hepatocytes. The HPLC studies revealed the presence of a number of phenicol compounds. The crude extract and the subsequent fractions of the plant possess strong hepatoprotective activity, providing a scientific rationale for its uses in the treatment of liver toxicities.


Author(s):  
qin wang ◽  
Kun Zhang ◽  
Rui-Lian Lin ◽  
Wenqi Sun ◽  
Mingfu Ye ◽  
...  

By using 1H NMR, ESI-MS and UV spectra, novel light-responsive molecular switch constructed by 1,1’-bis(benzyl)-4-[2-(4-pyridyl)-vinyl]-pyridinium (12+) and cucurbit[7]uril (Q[7]) is demonstrated. The E- to Z-isomerization of double bond in 12+...


2022 ◽  
Vol 924 (2) ◽  
pp. 70
Author(s):  
Brenna Mockler ◽  
Angela A. Twum ◽  
Katie Auchettl ◽  
Sierra Dodd ◽  
K. D. French ◽  
...  

Abstract Tidal disruption events (TDEs) provide a unique opportunity to probe the stellar populations around supermassive black holes (SMBHs). By combining light-curve modeling with spectral line information and knowledge about the stellar populations in the host galaxies, we are able to constrain the properties of the disrupted star for three TDEs. The TDEs in our sample have UV spectra, and measurements of the UV N iii to C iii line ratios enabled estimates of the nitrogen-to-carbon abundance ratios for these events. We show that the measured nitrogen line widths are consistent with originating from the disrupted stellar material dispersed by the central SMBH. We find that these nitrogen-to-carbon abundance ratios necessitate the disruption of moderately massive stars (≳1–2 M ⊙). We determine that these moderately massive disruptions are overrepresented by a factor of ≳102 when compared to the overall stellar population of the post-starburst galaxy hosts. This implies that SMBHs are preferentially disrupting higher mass stars, possibly due to ongoing top-heavy star formation in nuclear star clusters or to dynamical mechanisms that preferentially transport higher mass stars to their tidal radii.


2021 ◽  
Vol 12 (4) ◽  
pp. 419-431
Author(s):  
Soundararajan Krishnan ◽  
Thanigaimani Kaliyaperumal ◽  
Ramalingam Marimuthu ◽  
Sethuraman Velusamy

The crystal structure investigation of the title compound 4-((pyrrolidin-1-ylsulfonyl) methyl)aniline (PSMA) C11H16N2O2S shows that the molecule is essentially coplanar with a dihedral angle of 26.70(14)°between the pyrrolidine and the benzene rings. A pair of strong N-H···O hydrogen bonds produces continuous two-dimensional sheets with R22(18) ring motifs. The crystal structure also features a weak C-H···π interaction resulting in a three-dimensional network. Density functional theory (DFT) calculations reveal that the experimental and calculated geometric parameters of the molecule are nearly the same. Hirshfeld surface analysis has been carried out to study the various intermolecular interactions responsible for the crystal packing. Theoretical calculations indicate an excellent correlation between the experimental and the simulated UV spectra.


2021 ◽  
Author(s):  
Nora Mettig ◽  
Mark Weber ◽  
Alexei Rozanov ◽  
John P. Burrows ◽  
Pepijn Veefkind ◽  
...  

Abstract. Vertical ozone profiles from combined spectral measurements in the ultraviolet and infrared spectral range were retrieved by using data from TROPOMI/S5P and CrIS/Suomi-NPP, which are flying in loose formation three minutes apart in the same orbit. A previous study of ozone profiles retrieved exclusively from TROPOMI UV spectra showed that the vertical resolution in the troposphere is clearly limited (Mettig et al, 2021). The vertical resolution and the vertical extent of the ozone profiles is improved by combining both wavelength ranges compared to retrievals limited to UV or IR spectral data only. The combined retrieval particularly improves the accuracy of the retrieved tropospheric ozone and to a lesser degree stratospheric ozone up to 30 km. An increase in the degree-of-freedom by one was found in the UV+IR retrieval compared to the UV-only retrieval. Compared to previous publications, which investigated combinations of UV and IR observations from the pairs OMI/TES and GOME-2/IASI, the degree of freedom is lower, which is attributed to the reduced spectral resolution of CrIS compared to TES or IASI. Tropospheric lidar and ozonesondes were used to validate the ozone profiles and tropospheric ozone column (TOC). From the comparison with tropospheric lidars both ozone profiles and TOCs show smaller biases for the retrieved data from the combined UV+IR observation than the UV observations alone. While the TOCs show good agreement, the profiles have a positive bias of more than 20 % between 10 and 15 km. The reason is probably a positive stratospheric bias from the IR retrieval. The comparison of the UV+IR and UV ozone profiles up to 30 km with MLS (Microwave Limb Sounder) demonstrates the improvement of the UV+IR profile in the stratosphere.


2021 ◽  
Vol 3 (4) ◽  
pp. 746-812
Author(s):  
Gulnara Abd-Rashidovna Yuldasheva ◽  
Assel Kurmanaliyeva ◽  
Aleksandr Ilin

Chromatographic analysis shows that the ionic nanostructured complex of the FS-1 drug contains nanocomplexes of α-dextrin with a size of ~40–48 Å. Based on good agreement between the UV spectra of the model structures and the experimental spectrum of the FS-1 drug, the structure of the active FS-1 nanocomplex is proposed. The structure of the active centers of the drug in the dextrin ring was calculated using the quantum-chemical approach DFT/B3PW91. The active centers, i.e., a complex of molecular iodine with lithium halide (I), a binuclear complex of magnesium and lithium containing molecular iodine, triiodide (II), and triiodide (III), are located inside the dextrin helix. The polypeptide outside the dextrin helix forms a hydrogen bond with dextrin in Complex I and coordinates the molecular iodine in Complex II. It is revealed that the active centers of the FS-1drug can be segregated from the dextrin helix and form complexes with DNA nucleotide triplets. The active centers of the FS-1 drug are only segregated on specific sections of DNA. The formation of a complex between the DNA nucleotide and the active center of FS-1 is a key stage in the mechanisms of anti-HIV, anti-coronavirus (Complex I) and antibacterial action (Complex II).


Atmosphere ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1655
Author(s):  
Kumar Sarang ◽  
Krzysztof J. Rudziński ◽  
Rafał Szmigielski

This review thoroughly covers the research on green leaf volatiles (GLV) in the context of atmospheric chemistry. It briefly takes on the GLV sources, in-plant synthesis, and emission inventory data. The discussion of properties includes GLV solubility in aqueous systems, Henry’s constants, partition coefficients, and UV spectra. The mechanisms of gas-phase reactions of GLV with OH, NO3, and Cl radicals, and O3 are explained and accompanied by a catalog of products identified experimentally. The rate constants of gas-phase reactions are collected in tables with brief descriptions of corresponding experiments. A similar presentation covers the aqueous-phase reactions of GLV. The review of multiphase and heterogeneous transformations of GLV covers the smog-chamber experiments, products identified therein, along with their yields and the yields of secondary organic aerosols (SOA) formed, if any. The components of ambient SOA linked to GLV are briefly presented. This review recognized GLV as atmospheric trace compounds that reside primarily in the gas phase but did not exclude their transformation in atmospheric waters. GLV have a proven potential to be a source of SOA with a global burden of 0.6 to 1 Tg yr−1 (estimated jointly for (Z)-hexen-1-ol, (Z)-3-hexenal, and 2-methyl-3-buten-2-ol), 0.03 Tg yr−1 from switch grass cultivation for biofuels, and 0.05 Tg yr−1 from grass mowing.


Catalysts ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1478
Author(s):  
Mayra K. S. Monteiro ◽  
Ángela Moratalla ◽  
Cristina Sáez ◽  
Elisama V. Dos Santos ◽  
Manuel A. Rodrigo

Chlorine dioxide was produced by the reduction of chlorate with hydrogen peroxide in strongly acidic media. To avoid reaction interference during measuring procedures, UV spectra were acquired to monitor the chlorate reduction. This reduction led to the formation of chlorine dioxide and notable concentrations of chlorite and hypochlorous acid/chlorine, suggesting that the hydrogen peroxide:chlorate ratio is important. Once chlorates are transformed to chlorine dioxide, the surplus hydrogen peroxide promoted the further reaction of the chlorinated species down to less-important species. Moreover, chlorine dioxide was stripped with the outlet gas flow. A linear relationship was established between the amount of limiting reagent consumed and the maximum height of the absorption peak at 360 nm after testing with different ratios of hydrogen peroxide and chlorate, allowing calculations of the maximum amount of chlorine dioxide formed. To verify the reproducibility of the method, a test with four replicates was conducted in a hydrogen peroxide/chlorate solution where chlorine dioxide reduction was not promoted due to the presence of surplus chlorate in the reaction medium after the test. Results confirmed the efficient formation of this oxidant, with maximum concentrations of 8.0 ± 0.33 mmol L−1 in 400–450 min and a conversion percentage of 97.6%. Standard deviations of 0.14–0.49 mmol L−1 were obtained during oxidation (3.6–6.5% of the average), indicating good reproducibility.


Author(s):  
Indrani Chakraborty ◽  
Nirmal Chandra Sukul ◽  
Anirban Sukul ◽  
Rathin Chakravarty

Background: A homeopathic potency is usually given to the nursing mother for the treatment of her baby. Potencies above 12 CH cross the Avogadro number and are, therefore, too dilute to contain any original drug molecules. A potency is thought to be specifically structured water carrying the imprint of original drug molecules. It may convert the water structure in the body of the mother and through her milk reach the suckling baby. Using a toad model we have recently demonstrated that the antialcoholic effect of Nux vomica 200 CH could be transferred from one group of toads to another through capillary water which carries the information of Nux vomica. Homeopathic potencies show UV spectra distinct from its diluent medium of aquous ethanol. Does a potency remain effective even after passage through a living body? Objectives: To demonstrate that a potency effect can be transferred through the body of a live toad to other groups of toads connected through water to the live toad. Further, we want to see whether the UV spectra of drug solution and of water connected to the drug are similar in nature. Methods: A live toad was held vertically with one hind limb dipped in Nux vomica 200 CH solution in a beaker and another limb in distilled water in another beaker. The second beaker was connected by wet cotton threads encased in polythene tubes to 5 beakers, each of which contained adult toads in distilled water. A batch of toads was directly treated with Nux vomica 200 CH. An equal number of toads in distilled water served as the untreated control. After 30 min the control and the two batches of treated toads were kept separately in 209 mM ethanol solution. Toads, that stopped movement, were placed in supine position on a dry surface. Failure to assume a normal sitting posture within a cutoff time of 60 sec was regarded as loss of righting reflex (RR). The experiment was replicated using large number of toads. UV spectra of Nux vomica 200 CH solution and of water before and after connection with the drug were obtained. Results: The percentage of toads losing RR in the three groups of toads increased with time of exposure to 209 mM ethanol solution. The loss of RR was significantly delayed with the direct treatment group ( P < 0.001, chi square test) and the connected groups ( P < 0.01 , χ2 test ) as compared to the control. The two former groups did not differ from each other significantly. UV spectra of Nux vomica 200 CH solution were similar to that of water connected to the drug solution. Conclusion: The antialcoholic effect of Nux vomica 200 CH could be transferred through the body of a live toad to other groups of toads. The drug did not undergo denaturation during its passage through the living body. That water carries the information of original drug is further evidenced by the spectral properties of water connected to the drug solution through capillary water.


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