Geological and radioactivity studies accompanied by uranium recovery: Um Bogma Formation,southwestern Sinai,Egypt

Journal of Radioanalytical and Nuclear Chemistry - High radioactive anomalies were recorded in the variegated claystones at the middle member of Um Bogma Formation, the eU-content reaches...     

Influence of various diet regimens on deterioration of hepatic function and hematological parameters following carbon tetrachloride: a potential protective role of natural honey

The objective was to assess the effects of commercial regular diet as control, total food restriction with honey, commercial regular diet with dextrose, or total food restriction with dextrose, on blood variables after carbon tetrachloride (CCl4) administration. Sprague Dawley albino rats were divided into four groups, 10 rats each; Group 1 rats were on commercial regular diet, Group 2 rats were on commercial regular diet with 50% dextrose, Group 3 rats were on total food restriction with 50% dextrose, and Group 4 rats were on total food restriction with 50% honey. Rats in all the groups were i.m. administered CCL4 (2.4 mL kg b. wt.-1). Blood tests including ALT, AST, serum albumin, serum protein, BUN, blood glucose (BG), hemoglobin (Hb), and white blood cell (WBC) were performed before CCl4 administration and repeated after 48 and 96 h of post-injection. In Group 1, CCl4 caused significant elevation in AST and ALT, and decrease in BS, WBC, and BUN; lower elevation in AST and ALT at 48 h and decreased AST and ALT at 96 h were obtained when dextrose was added to commercial regular diet (Group 2). Using dextrose alone (Group 3), though there was significant elevation of AST and ALT and decrease in BUN and WBC as compared to baseline values, significant decrease in ALT, AST, and BUN as compared to control was obtained. During absolute honey feeding (Group 4), elevation in AST and ALT obtained, following CCl4 administration was significantly less than the values obtained in all other groups; with lower elevation in AST and ALT as compared to baseline values. Honey increased serum albumin, serum protein, BG, and caused lower reduction in Hb. Conclusively, exclusive honey feeding (50% concentration) significantly modifies and ameliorates biochemical and hematological changes obtained after CCl4 injection.     

Effect of Nano‐support and Type of Active Metal on Reforming of CH4 with CO2

Two series of Co and Ni based catalysts supported over commercial (ZrO₂, CeO₂, and Al₂O₃) nano supports were investigated for dry reforming of methane. The catalytic activity of both Co and Ni based catalysts were assessed at different reaction temperatures ranging from 500—800 °C; however, for stability the time on stream experiments were conducted at 700 °C for 6 h. Various techniques such as N₂ adsorption‐desorption isotherm, temperature‐programmed reduction (H₂‐TPR), temperature‐programmed desorption (CO₂‐TPD), temperature‐programmed oxidation (TPO), X‐ray diffraction (XRD), thermogravimetric analysis (TGA) were applied for characterization of fresh and spent catalysts. The catalytic activity and stability tests clearly showed that the performance of catalyst is strongly dependent on type of active metal and support. Furthermore, active metal particle size and Lewis basicity are key factors which have significant influence on catalytic performance. The results indicated that Ni supported over nano ZrO₂ exhibited highest activity among all tested catalysts due to its unique properties including thermal stability and reducibility. The minimum carbon deposition and thus relatively stable performance was observed in case of Co‐Al catalyst, since this catalyst has shown highest Lewis basicity.     

Preparation,Spectroscopic and Structural Investigations of Spiro Derivatives of Hexachlorocyclotriphosphazatriene

Abstract

Mono-(N₃P₃Cl₄Y₂), bis-(N₃P₃Cl₂Y₄) and tris-spiro derivatives (N₃P₃Y₆) have been prepared with ethylene, 1, 3-propylene and 1,4-butylene glycols (Y₂ = glycol residue). The ¹H NMR spectra of mono- and tris-derivatives are relatively simple; those of the bis- very complex due to the intrinsic asymmetry of the methylene protons. This effect is made use of in studying the replacement pattern of N₃P₃Cl₄ [O (CH₂)₃O] with primary and secondary amines. Homonuclear ¹H decoupling simplifies the spectra and allows an unambiguous distinction to be made between the different isomeric possibilities of the bis amino derivatives N₃P₃Cl₂R₂ [O(CH₂)₃O] where R = amino residue. Primary amines give geminal, secondary amines nongeminal trans-derivatives. The trans-structure of the bis-pyrrolidino derivative has been confirmed by X-ray crystallography.     

Poly[diaquadi‐μ6‐oxalato‐μ5‐oxalato‐chromium(III)rubidium(I)]: a new supramolecular isomer

The title compound, [CrRb(C₂O₄)₂(H₂O)₂]_n, obtained under hydrothermal conditions and investigated structurally at 100 K, is a three‐dimensional supramolecular isomer of the layered structure compound studied at room temperature. This novel polymer is built up from crosslinked heterobimetallic units. The linkage of alternating edge‐ and vertex‐shared RbO₇(H₂O)₂ and CrO₄(H₂O)₂ polyhedra running along three different directions gives a dense packing. The two independent ligands display two η⁴‐chelation modes and two conventional carboxylate bridges. However, the pentadentate ligand connects the Cr^III and Rb^I ions through one O‐atom bridge, while the hexadentate ligand exhibits an additional η³‐chelation and two O‐atom bridges. Each coordinated water molecule forms an O‐atom bridge between the two metals. Moreover, in the absence of protonated ligands, these water molecules act as donors through their four H atoms in strong‐to‐weak hydrogen bonds. This results in zigzag chains of alternating oxalate and aqua ligands parallel to the twofold screw axis. The six double oxalates known to date containing an alkali and Cr^III all present layered two‐dimensional structures. In the series, this supramolecular isomer is the first three‐dimensional framework.     

Time-Dependent Density Functional Theory Study on Hydrogen and Dihydrogen Bonding in Electronically Excited State of 2-Pyridone–Borane–Trimethylamine Cluster

In this work, the intermolecular dihydrogen and hydrogen bonding interactions in electronically excited states of a 2-pyridone (2PY)–borane–trimethylamine (BTMA) cluster have been theoretically studied using time-dependent density functional theory method. Our computational results show that the S₁ state of 2PY–BTMA cluster is a locally excited state, in which only 2PY moiety is electronically excited. The theoretical infrared (IR) spectra of the 2PY–BTMA cluster demonstrate that the N–H stretching vibrational mode is slightly blue-shifted upon the electronic excitation. Moreover, the computed IR spectrum of the 2PY–BTMA cluster exhibits no carbonyl character due to the extension of the C=O bond length in the S₁ state. However, the N–H bond is shortened slightly upon photoexcitation. At the same time, the H···H and H···O distances are obviously lengthened in the S₁ sate by comparison with those in ground state. In addition, the electron density of the carbonyl oxygen is diminished due to the electronic excitation. Consequently, the proton acceptor ability of carbonyl oxygen is decreased in the electronic excited state. As a result, it is demonstrated that the intermolecular dihydrogen and hydrogen bonds are significantly weakened in the electronically excited state.     

Amorphous metal-aluminophosphate catalysts for aldol condensation of n-heptanal and benzaldehyde to jasminaldehyde

Amorphous aluminophosphate (AlP) and metal‐aluminophosphates (MAlPs, where M=2.5 mol%Cu, Zn, Cr, Fe, Ce, or Zr) were prepared by coprecipitation method. Their surface properties and catalytic activity ...     

Carbonyl ylide reactions of α-benzylidene-β-dicarbonyl compounds: competitive formation of dihydrofurans and dihydrobenzoxepines

α-Benzylidene-β,β′-biscarbonyl compounds were reacted with dimethyl diazomalonate using Cu(II) acetylacetonate as a catalyst. Dihydrofurans or mixtures of dihydrofurans and dihydrobenzoxepines were obtained depending on the nature of the carbonyl group present in the starting material.     

Assessment of Antioxidant and Anticancer Activities of Microgreen Alga Chlorella vulgaris and Its Blend with Different Vitamins

There is a very vital antioxidant extracted from microgreen alga. Chlorella vulgaris has major advantages and requires high yield worldwide. Some microalgae require vitamins for their growth promotion. This study was held to determine the impact of different vitamins including Thiamine (B1), Riboflavin (B2), Pyridoxine (B6), and Ascorbic acid (c) at concentrations of 0.02, 0.04, 0.06, and 0.08 mg/L of each. Each vitamin was added to the BG11 growth medium to determine the effect on growth, total carbohydrate, total protein, pigments content, antioxidant activities of Chlorella vulgaris. Moreover, antitumor effects of methanol extract of C. vulgaris without and with the supplement of thiamine against Human prostate cancer (PC-3), Hepatocellular carcinoma (HEPG-2), Colorectal carcinoma (HCT-116) and Epitheliod Carcinoma (Hela) was estimated in vitro. C. vulgaris supplemented with various vitamins showed a significant increase in biomass, pigment content, total protein, and total carbohydrates in comparison to the control. Thiamine was the best vitamin influencing as an antioxidant. C. vulgaris supplemented with thiamine had high antitumor effects in vitro. So, it’s necessary to add vitamins to BG11 media for enhancement of the growth and metabolites.