Welcome to the inaugural Issue of Pakistan BioMedical Journal

Firstly, I would like to welcome all the readers, authors, editorial team and management of Pakistan Biomedical Journal (PBMJ) to this new journal in Biomedical Sciences. It is an intenational peer-reviewed, open-access journal that merges the basic and clinical research for the better outcome in terms of diagnosis and therapeutics. This approach will update and upgrade the existing knowledge among the researchers and clinicians, regarding the patient care and practice as well as understanding of underlying mechanisms of diseases. The ultimate beneficiary is patient and community as a whole. PBMJ is led by an outstanding Editorial Board comprising of national and international members with multidisciplinary research background. Our goal is to promote the basic and clinical research, health and disease perspectives. We receive original studies, review articles, case reports, systemetic reviews on medical, biomedical, basic and therapeutic research. We welcome scientific contributions from all over the world. It is the need and demand of the recent world scenario to focus on biomedical research. In the current world, basic and medical science cannot be considered as two separate and independent entities. There should be coherent efforts to unveil the basic understandings of pathologies at physiological, cellular and molecular level. Furthermore, the therapeutic strategies should also be explored on regional and global levels, by keeping in mind the different genetic makeups and considering the individual identities. It leads to the field of ‘personalized medicine’. There are many other recent therapeutic regimens such as regenerative medicine, exosomes, gene silencing and gene editing technologies. The world has also advanced in diagnostic modalities. Much focus has been emphasized on rapidness, accuracy and cost-effectiveness of these techniques. Imaging, scanning, histopathological, biochemical and hematological techniques have been much advanced than before. World has been changing rapidly in medical profession. Hence, it is important to be aware of these advancements worldwide and also to share the health related researches at local level. We hope this new journal will be a good addition in this perspective of sharing the recent knowledge, advancements and create awareness among masses.

Investigation of Rare Earth and Transition Metals Substituted X-Type Hexagonal Ferrites for Microwave Applications

The present work is focused on the fabrication of Sr-Ba based X-type ferrites substituted with transition metals (TM: Ni, Co), and trivalent rare-earth cations (Nd, Dy, Pr, Gd) for microwave applications. This dissertation presents a systematic study on four series namely, SrBaCu2-xNixNdyFe28-yO46, SrBaMg2-xNixCoyFe28-yO46, SrBaZn2-xNixPryFe28-yO46 and SrBaMn2-xCoxGdyFe28-yO46 (x=0 to 1.0 and y=0 to 0.1) of hexagonal ferrites. These X-type materials were fabricated by sol-gel method at 1250 °C temperature. The thermal decomposition of nitrate-citrate gel of as-synthesized samples and estimation of sintering temperature to obtain X-type phase was determined by DSC, TGA, and DTA analysis. X-Ray Diffraction patterns revealed pure X-type hexagonal phase of the investigated X-type hexaferrites, except for the series doped with Dy-Co an extra peak of orthorhombic phasedetected as DyFeO3 appeared for higher concentrations of Dy content. Lattice parameters (lattice constants, porosity, X-ray density, bulk density, crystalline size) showed variations with dopants (RE-TM) and their concentrations. There was increase in lattice constants (a, c) with increase in dopants concentration which was attributed to introduction of higher ionic radius of RE3+ cations in octahedral sites of Fe3+ ions.FTIR spectral study revealed the presence of absorption bands in the range 400-600 cm-1which are characteristics of hexaferrites. It was observed that substitution of RE-TM ions caused shifting of band positions due to change in metal-oxygen bond length at A- and B-sites. From hysteresis loops magnitudes of saturation magnetization, coercivity as well as retentivity were calculated. It was observed that magnetic parameters (saturation magnetization, retentivity, coercivity) were enhanced with RE-TM doping in these X-type ferrites. For all samples, the values of saturation magnetization varied in range from 40 to 65 emu/g, and coercivity was found in range 1500-3500 Oe, the high values of Ms and Hcsuggested application of these RE-TM doped X-type ferrites in high density video recording and permanent magnets. The dielectric characteristics were carried out in frequency range 1 MHz to 3 GHz. The real and imaginary parts of dielectric constant and tangent loss were decreased with the increase of frequency on the basis of Wagner and Koop''s theory. The resonance peak appeared in all samples above 2 GHz (i.e. in MW band) which is characteristics of materials used for EMI attenuation. The doping of RE-TM resulted in increase of dielectric constant, AC conductivity and Q-value for all series. In the Present studies it had been found that Q-factor decreased with concentration of RE-TM ions which reflected the fact that with addition of RE-TM substitution the loss of energy has been enhanced. Reduced size, high porosity, high losses, low Q values and high saturation magnetization endorsed these X-type materials for microwave absorption applications such as in mobiles, medicine, satellite communication, stealth and RAM etc.