Visual spatial memory is enhanced in female rats (but inhibited in males) by dietary soy phytoestrogens

Background  

In learning and memory tasks, requiring visual spatial memory (VSM), males exhibit superior performance to females (a difference attributed to the hormonal influence of estrogen). This study examined the influence of phytoestrogens (estrogen-like plant compounds) on VSM, utilizing radial arm-maze methods to examine varying aspects of memory. Additionally, brain phytoestrogen, calbindin (CALB), and cyclooxygenase-2 (COX-2) levels were determined.     

Conformational properties of a phototautomerizable nucleoside biomarker for phenolic carcinogen exposure

We have characterized the conformational properties of the C8-deoxyguanosine (C8-dG) nucleoside adduct, 8-(2"-hydroxyphenyl)-2'-dG (1), which is a potential biomarker for exposure to phenolic carcinogens. Adduct 1 possesses the unique ability to phototautomerize, through an excited-state intramolecular proton transfer (ESIPT) process, to generate its keto form. This tautomerization depends on the presence of an intramolecular hydrogen (H)-bond between the phenolic OH and the imine nitrogen (N7) and has permitted insight into the equilibrium ground states of adduct 1. The results of our studies demonstrate that adduct 1 undergoes an ESIPT despite preferring a nonplanar "twisted" conformation that is imposed by the deoxyribose (dR) sugar moiety. Interestingly, a planar conformation of adduct 1 is also formed in certain aprotic solvents due to the anchoring effect of the intramolecular H-bond. Our results provide a basis for future studies aimed at determining the conformations of adduct 1 within DNA that will aid in our understanding of phenol-mediated carcinogenesis.     

Supramolecular structures and columnar mesophase induction in nondiscoid pyrazoles by complexation to rhodium(I)

Several new cis-[RhCl(CO)2(Ln)] complexes have been prepared using different polycatenar pyrazole ligands (Ln) in order to obtain columnar liquid crystalline arrangements. The topology of the ligand plays an essential role, and a mesophase is induced at room temperature from a nonmesogenic pyrazole only when it is symmetrically substituted with six decyloxy chains. The single-crystal structure of a methoxy-substituted analogue, 3,5-bis(3,4,5-trimethoxyphenyl)pyrazole, is formed by globular tetrameric structures held together by H-bonding. However, parallel dimers are present in the corresponding cis-chlorodicarbonylrhodium(I) complex, a situation that explains the induction of a columnar mesophase in the decyloxy-substituted complex. The XRD pattern of the mesophase is consistent with a hexagonal symmetry in which the columns are formed by molecules assembled in an antiparallel mode. The crystal-to-mesophase transition was also detected by spectroscopic techniques as a shift in the IR carbonyl stretching bands and the appearance of a charge-transfer band in the absorption spectrum with thermochromic behavior.     

The application of homotopy analysis method to solve nonlinear differential equation governing Jeffery–Hamel flow

In this paper Jeffery–Hamel flow has been studied and its nonlinear ordinary differential equation has been solved through homotopy analysis method (HAM). The obtained solution in comparison with the numerical ones represents a remarkable accuracy. The results also indicate that HAM can provide us with a convenient way to control and adjust the convergence region.     

Neuromodulation by soy diets or equol: Anti-depressive &; anti-obesity-like influences,age- &; hormone-dependent effects

Background  

Soy-derived isoflavones potentially protect against obesity and depression. In five different studies we examined the influence of soy-containing diets or equol injections on depression, serotonin levels, body weight gain (BW) and white adipose tissue (WAT) deposition in female Long-Evans rats at various stages of life [rats were intact, ovariectomized or experienced natural ovarian failure (NOF)].     

Silver pyrazolates as coordination-polymer luminescent metallomesogens

Silver pyrazolates with columnar liquid-crystal phases that are stable at room temperature have been prepared by reaction of silver nitrate with 3,5-diarylpyrazolates. The complexes consist of open-chain oligomers, despite the fact that the most common structural type for homoleptic coinage metal pyrazolates is the trimeric metallacycle [M(μ-pz)](3). The special characteristics of silver in forming reversible metal-ligand bonds in solution, evidenced experimentally, leads to supramolecular organizations in which the silver cations promote self-organization of the nonmesomorphic pyrazolates into helical 1D polymers that exhibit columnar mesophases. The materials are readily soluble in common organic solvents and are liquid-crystalline over a broader temperature range than their gold counterparts, which are known to form discrete cyclic trinuclear species. Thin films of the silver complexes show luminescence at room temperature. The compounds described here are the first examples of luminescent metallomesogens formed by a main-chain coordination polymer.     

The physics of diamond

The accurate measurement of the thermal conductivity of metals still poses considerable experimental difficulty. The reasons for this, and the main ways in which the problem has been approached, are summarized. A detailed examination of the development in technique and methods of measurement shows that while most of the steady-state methods introduced over 50 years ago are still being improved, the emphasis in the last few years has been on the development of methods which give more rapid results, particularly at high temperatures.