Synthetic, crystallographic, computational, and biological studies of 1,4-difluorobenzo[c]phenanthrene and its metabolites

1,4-Difluorobenzo[c]phenanthrene (1,4-DFBcPh) and its putative metabolites, the dihydrodiol and diol epoxides, have been synthesized and structurally characterized, and the extent of DNA binding by the metabolites has been assessed. 1,4-DFBcPh and 1,4-difluoro-10-methoxybenzo[c]phenanthrene were prepared by photochemical cyclization of appropriate naphthylphenylethylenes. The dihydrodiol was synthesized from 1,4-difluoro-10-methoxybenzo[c]phenanthrene, and the diol epoxides were diastereoselectively synthesized from the dihydrodiol. Interesting differences were noted in 1H NMR spectra of the series 1 (syn) diol epoxides of benzo[c]phenanthrene (BcPh) and 1,4-DFBcPh; the BcPh diol epoxide displays a quasi-diequatorial orientation of the hydroxyl groups, but in the 1,4-DFBcPh case these are diaxially disposed. This difference probably stems from the presence of the fjord-region fluorine atom in 1,4-DFBcPh. A through-space, fjord-region H-F coupling has also been observed for 1,4-DFBcPh and its derivatives. Comparative X-ray crystallographic analyses of BcPh and 1,4-DFBcPh and their dihydrodiols show that introduction of fluorine increases the molecular distortion by about 6-7 degrees . As a guide to estimating the molecular distortion and its effects, and for comparison with the X-ray structures in known cases, optimized structures of BcPh, 1,4-DFBcPh, and 1,4-DMBcPh (the dimethyl analogue) as well as their dihydrodiols and diol epoxides were computed. Relative aromaticities of these compounds were assessed by nucleus-independent chemical shift calculations, and 13C NMR chemical shifts were computed by gauge-inducing atomic orbital calculations. 1,4-DFBcPh and its dihydrodiol were subjected to metabolism, and the amount of DNA binding in human breast cancer MCF-7 cells was assessed. The extent of DNA binding was then compared with that for BcPh and its dihydrodiol and the potent carcinogen benzo[a]pyrene. The 1,4-DFBcPh series 2 (anti) diol epoxide-derived DNA adducts were also compared with those arising from intracellular oxidation of the dihydrodiol with subsequent DNA binding. These experiments showed that increased molecular distortion decreased metabolic activation to the terminal metabolites but that diol epoxide metabolites that are formed are the DNA-damaging species.     

An investigation of the biogeochemistry of the uranium radionuclide in the munitions testing contaminated soil of Kirkcudbright, New Galloway, SW Scotland

The understanding of the bio-geochemical behavior of the uranium radionuclides in the environmental matrices is crucial for the health safety point of view. The research was carried out in munitions testing sites New Golloway (SW) of Scotland at the Dunderann firing range which is contaminated with depleted uranium and site is particularly important because it provides a controlled environment for the investigation of post depositional association of Depleted Uranium (DU) in contaminated soils. This study used the modified BCR sequential extraction method to investigates the association of DU in at the different sampling location and in a control soil and were followed by elemental analysis using inductively coupled-optical Emission spectroscopy (ICP-OES).The Certified Reference Material (CRM) were used for the validation of the concentration. The concentrations of (Bureau of Reference) BCR-extracted Uranium (U) were in the range of 4–40 (±13.2) mg kg⁻¹ for the DU-contaminated sites whilst U was barely detectable in the soil from the control site (Rebury Gun) RGW. With the exception of RGH and RGW, the values for BCR-extracted U compared well with those obtained using Aqaua-regia. The obtained result showed that the maximum Uranium deposition is at RGE and it is 20 mg kg⁻¹ before hitting the target, the 6 mg kg⁻¹ at RGH and minimum is at RGG and RGW control site.     

Antioxidant Effect of Azadirachta Indica on High Fat Diet Induced Diabetic Charles Foster Rats

Oxidative stress plays a major role in the pathogenesis of both types of diabetes mellitus. Excessively high levels of free radicals cause damage to cellular proteins, membrane lipids and nucleic acids, and eventually cell death. The present study was designed to investigate the possible effect of Azadirachta indica leaf extract in high fat diet induced diabetic Charles Foster rats. The increased level of lipidperoxidation and altered levels of enzymatic (superoxide dismutase, glutathione peroxidase and catalase) and non-enzymatic (glutathione) antioxidants were seen in high fructose fed animals. The treatment with A. indica leaf extract significantly normalized the altered levels of lipid peroxidation and antioxidant status at 400?mg/kg b.w. dose. The A. indica leaf extract was also tested for in vitro inhibition of generation of superoxide anion and hydroxyl free radical in both enzymatic and non-enzymatic systems. The A. indica leaf extract was found to inhibit generation of superoxide anion and hydroxyl free radical significantly at 200???g/ml concentration. Data of present study demonstrated that the A. indica leaf extract has both antidiabetic and antioxidant properties.     

Analytic Calculation of Neutrino Mass Eigenvalues

Implication of the neutrino oscillation search for the neutrino mass square difference and mixing are discussed. We have considered the effective Majorana mass m _ee , related for ββ _0ν decay. We find limits for neutrino mass eigen value m _i in the different neutrino mass spectrum,which explain the different neutrino data.     

Sub-diffraction-limited far-field imaging in infrared

We investigated a far-field superlens operating at mid-infrared wavelength that allows resolving subwavelength features in the far-field. By utilizing evanescent enhancement provided by surface plasmon excitation of silver nanorods and Moiré effect, we numerically demonstrated that subwavelength information of an object can be converted to propagating information. This information can then be captured by conventional optical components. A simple image reconstruction algorithm can restore the subwavelength object. A sub-diffraction-limited resolution of 2.5 μm at 6-μm wavelength is demonstrated.     

Applicability of equation of state in extreme compression region and study of diatomic solids under pressure

In the present study, the expression of first pressure derivative of bulk modulus B′?earlier derived by Goyal and Gupta EoS [7] is corrected and the validity of the EoS is then verified in extreme compression region. The expressions of second and third order pressure derivative $(B^{{}^{″}},B^{″\prime })$of bulk modulus are obtained. The values of B′, B²B? to BB″,?Grunesien parameters?λ_∞,?γ_∞,?q_∞ at infinite pressure (P?→?∞)?are calculated using the identities [11–13] to check the validity of the equation in extreme compression region. The Goyal and Gupta EoS is then used to study the volume compression in diatomic solids, LiH and MgO. The values of pressure, bulk modulus and its first order pressure derivative at different compressions are calculated and compared with the results obtained from Hama–Suito EoS. The results justify the validity of the present EoS in high pressure region and the results for diatomic solids are also found in good consistency with the compared results.     

Schwinger representation for the symmetric group: Two explicit constructions for the carrier space

We give two explicit constructions for the carrier space for the Schwinger representation of the group Sn. While the first relies on a class of functions consisting of monomials in antisymmetric variables, the second is based on the Fock space associated with the Greenberg algebra.     

Oscillations and fluctuations in a dissipative spin system

A dissipative spin system, which is also considered to be a model for optical fluorescence, is investigated from the viewpoint of Brownian motion of spins. The most probable path and the fluctuations are determined by the quantum mechanical version of the system size expansion method. For the most probable path, the flow lines as well as the time evolutions are obtained exactly. This system exhibits a sort of nonequilibrium phase transition as the strength of an external field exceeds the dissipation. The fluctuations show unusual behaviour associated with the Volterra-like oscillations above threshold.     

Application of self seeding technique in regulating polymorphic transformations during non-isothermal bulk crystallization of polymers

Non-isothermal melt crystallization of trans-1,4-polyisoprene (TPIP) has been studied with the help of differential scanning calorimetry (DSC) and wide-angle x-ray diffraction. Self-seeding has been used for the controlled growth of polymorphs. Thus, self-seeding below 55° and below 71°C has led to the exclusive crystallization of and polymorphs, respectively, upon non-isothermal cooling of the polymer melt. These temperatures may vary slightly with the previous thermal history and molecular characteristics of the original sample. It has been interpreted that during cooling the rate of growth (by secondary nucleation) of seeds of either polymorph remains much faster than the rate of primary nucleation of the other polymorph whose seeds are not present in the melt. As a result, the crystallizing melt becomes occupied by the spherulites of the seeded polymorph well before the other polymorph can nucleate.