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their centers. The planar compounds of boron without Bi 2O 3 addition, have been achieved. The
which exhibit similar bond distance but have no Curie temperatures were found to be unaffected on
symmetry-attraction are mentioned as exception. bismuth concentration. The room temperature
resistivity increases with increasing of bismuth
033 CHOWDHURY, M. Z.A. & SHYAM, L.K. addition.
(Dept. of Chemistry, University of Chittagong,
Chittagong). EFFECT OF SYMMETRY-REPULSION
ON THE EQUALITY OF BOND DISTANCES IN 539. 16 : PHYSICS : RADIOACTIVITY
TETRAHEDRAL AB 4 MOLECULES, J. Bang. Acad.
Sci., 2006, 30 (2), 233-237.
035 ALAM, M. K (Institute of Food Radiation
The reason for the equality of four A-B bond Biology, Atomic Energy Research Establishment.
distances in tetrahedral AB 4 molecules is Dhaka). DOSE LIMIT FOR MEASURING
investigated with the help of group theory. This GAMMA RADIATION INDUCED FORMATION
investigation indicates that the equality of these OF 8-OXOGUANINE IN THE DNA LEVEL. J.
bonds is caused by the repulsion between the Bang. Acad. Sci., 2007, 31 (1), 97-102.
valence orbitals which have the same symmetry
properties. In the molecules of both transition and Gamma radiation induced formation of 8-
non-transition central atoms, ns and np orbitals are oxoguanie was demonstrated in the Chinese
involved in bonding and (n+l)d, nd or (n-l)d hamster ovary cell line (CHO-K1) and E. coli
orbitals, remain in the non-bonding level. Since the DNA by enzyme-linked immunosorbent assay
triply degenerate d orbitals have the same (ELISA) using monoclonal antibodies against 8-

symmetry property t 2 as the triply degenerate p oxoguanine. From the dose response study, it was
observed that there is some maximum level of dose
orbitals, their repulsion is expected to depress the
energy of p orbitals to bring them closer to that of s beyond which the 8-oxoguanine cannot be
orbital. This closeness in energy may be detected, which is observed due to the strand
breaking of the DNA molecules.
responsible for making the four bonds equivalent
in all tetrahedral AB 4 molecules.
036 ALAM, M.K. & BEGUM, S. (Institute
034 SAHA, D.K. & HAKIM, M.A. of Food and Radiation Biology, Atomic Energy
(Materials Science Division, Atomic Energy Research Establishment, Dhaka). GAMMA
Center, Dhaka). EFFECT OF Bi 2O 3 ADDITION ON IRRADIATION INDUCED FORMATION OF 8-
HYDROXYDEOXYGUANINE AT DNA LEVEL IN
LOWERING THE SINTERING TEMPERATURE
OF Ni-Cu-Zn FERRITE. J. Bang. Acad. Sci., 2006, CHO-K1 CELL LINE. Bang. J. Zool. 2006, 34 (1),
30 (1), 55-63. 41-46.

Effect of Bi 2O 3 addition (0-2.0 wt.%) to lower the A dose response of radiation against 8-
hydroxydeoxyguanine residue of the DNA
sintering temperature, T s of Ni 0.35 Cu 0.15 Zn s0.50Fe 2 O 4 molecule of Chinese hamster (Cricertulus griseus)
ferrite has been investigated using conventional
ceramic technique. X-ray diffraction study confirmed ovary cell line (CHOK1) by enzyme linked
the single-phase spinel structure of all the samples immunosorbent assay using monoclonal antibody
under investigation. It was found that the sintering was investigated. The differences of absorbencies
temperature could be reduced by 250°C as compared by the antigen-antibody complex indicate that the
to Ni-Cu-Zn ferrite when Bi 2O 3 (>1.2 wt.%) was EL1SA technique can be applied to observe the
added to it. Post sintering density and the initial radiation shock of the CHO Kl cell line.
magnetic permeability of the sintered ferrite are
strongly dependent on Bi 2O 3 content and sintering 037 ALAM, M. K. (Institute of Nuclear
temperature. With the addition of 2.0 wt.% Bi 2O 3, Science & Technology, Atomic Energy Research
97.5% of the theoretical density (T s=1000°C) and Establistment, Dhaka).; ISLAM M.N &
permeability of 600 (T s=1200°C) compared with ZAMAN, M.A. (Dept. of Physics, Jahangirnagar
that of 94% and 339, respectively, at T s=1200°C University, Savar, Dhaka). STUDY OF

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