Electronic structure of spin 1/2 Heisenberg antiferromagnetic systems: Ba_2Cu(PO_4)_2 and Sr_2Cu(PO_4)_2

We have employed first principles calculations to study the electronic structure and magnetic properties of the low-dimensional phosphates, Ba2Cu(PO4)2 and Sr2Cu(PO4)2. Using the self-consistent tight-binding lin- earized muffin-tin orbital method and the Nth order muffin-tin orbital method, we have calculated the various intrachain as well as the interchain hopping parameters between the magnetic ions Cu2+ for both the com- pounds. We find that the nearest-neighbor intrachain hopping t is the dominant interaction suggesting the compounds to be indeed one dimensional. Our analysis of the band dispersion, orbital projected band struc- tures, and the hopping parameters confirms that the Cu2+-Cu2+ super-super exchange interaction takes place along the crystallographic b direction mediated by O-P-O. We have also analyzed in detail the origin of short-range exchange interaction for these systems. Our ab initio estimate of the ratio of the exchange inter- action of Sr2Cu(PO4)2 to that of Ba2Cu(PO4)2 compares excellently with available experimental results.Comment: 6 pages, 4 figure

Local magnetism of isolated Mo atoms at substitutional and interstitial sites in Yb metal : Experiment and Theory

Using TDPAD experiment and local spin density calculations, we have observed large 4d moments on isolated Mo atoms at substitutional and octahedral interstitial lattice sites in Yb metal, showing Curie-Weiss local susceptibility and Korringa like spin relaxation rate. As a surprising feature, despite strong hybridization with the Yb neighbours, interstitial Mo atoms show high moment stability with small Kondo temperature. While, magnetism of Mo, at substitutional site is consistent with Kondo type antiferromagnetic d-sp exchange interaction, we suggest that moment stability at the interstitial site is strongly influenced by ferromagnetic polarization of Yb-4f5d band electrons.Comment: 4 pages, 4 figure

Structural transformations in protein crystals caused by controlled dehydration

Recent experiments in this laboratory on structural transformations caused by controlled dehydration of protein crystals have been reviewed. X-ray diffraction patterns of the following crystals have been examined under varying conditions of environmental humidity in the relative humidity range of 100-75%: a new crystal form of bovine pancreatic ribonuclease A grown from acetone solution in tris buffer (I), the well-known monoclinic form of the protein grown from aqueous ethanol (II), the same form grown from a solution of 2-methyl pentan-2,4-diol in phosphate buffer (III), tetragonal (IV), orthorhombic (V), monoclinic (VI) and triclinic (VII) hen egg white lysozyme, porcine 2 Zn insulin (VIII), porcine 4 Zn insulin (IX) and the crystals of concanavalin A(X). I, II, IV, V and VI undergo one or more transformations as evidenced by discontinuous changes in the unit cell dimensions, the diffraction pattern and the solvent content. Such water-mediated transformations do not appear to occur in the remaining crystals in the relative humidity range explored. The relative humidity at which the transformation occurs is reduced when 2-methyl pentan-2,4-diol is present in the mother liquor. The transformations are affected by the crystal structure but not by the amount of solvent in the crystals. The X-ray investigations reviewed here and other related investigations emphasize the probable importance of water-mediated transformations in exploring hydration of proteins and conformational transitions in them

Toxicological studies on Helicoverpa armigera in pigeonpea growing in Vidarbha region of Maharashtra, India

Insecticide resistance level in pigeonpea pod borer, Helicoverpa armigera (Hubner) to technical grade insecticides collected from major pigeonpea growing districts of Vidarbha viz., Akola, Amravati, Buldhana, Yavatmal and Washim was worked out. LDP indicated LD50 of Cypermethrin in the range of 1.402 to 9.209 ppm with maximum in Yavatmal (9.209 ppm); LD90 within range of 6.021 to 18.427 ppm. LD50 of Quinalphos in the range of 1.303 to 4.789 ppm with maximum in Yavatmal (4.789 ppm); LD90 within range of 3.150 to 14.194 ppm.LD50 of Methomyl in the range of 1.297 to 3.792 ppm with maximum in Yavatmal (3.792 ppm); LD90 within range of 4.993 to 16.737 ppm.LD50 of Indoxacarb in the range of 0.521 to 2.709 ppm with maximum in Yavatmal (2.709 ppm); LD90 within range of 2.819 to 20.947 ppm.LD50 of Spinosad in the range of 0.713 to 2.408 ppm with maximum in Buldhana (2.408 ppm); LD90 within range of 6.413 to 18.349 ppm. The resistance level is visibly high in cypermethrin, moderate to indoxacarb, quinalphos, spinosad and low to methomyl; Yavatmal and Washim strains expressed higher resistance level to cypermethrin, quinalphos and methomyl, whereas Yavatmal and Buldhana strains expressed higher resistance level to indoxacarb and spinosad. The investigation will help to track resistence level in Helicoverpa armigera to different groups of insecticides

Fixed Point Theorems for Expansion Mappings in Cone Rectangular Metric Spaces

Abstract In this paper we prove some fixed point theorems for mappings satisfying expansive conditions in cone rectangular metric spaces

Acceptability of different oral dosage forms in paediatric patients in hospital setting

Objective The understanding of acceptability of existing dosage forms is limited in most of the world and hinders the development of acceptable, age‐appropriate medicines. The attributes of paediatric medicine acceptability may differ from country to country based on culture, healthcare infrastructure and health policies. This study was designed to map the acceptability of oral medicines in paediatric patients treated in hospital in India. Methods An observational, cross-sectional study was conducted in patients aged below 18 years and taking any form of oral medication. Acceptability scores were obtained using CAST–ClinSearch Acceptability Score Test tool. Findings 490 patients were recruited and 193 evaluations of different pharmaceutical products available in 20 dosage forms and 7 routes of administration were studied. Oral liquids (50%) and tablets (35%) were the most commonly prescribed and administered forms. Regardless of the therapeutic class and age, the oral liquids were ‘positively accepted’ in infants and toddlers. Acceptability of tablets improved with age and appeared to be generally good from the age of 6. Conclusion This study indicates the limited progress towards adoption of age-appropriate dosage forms in India and thus impact on the acceptability of existing oral dosage forms. The key challenges posed by the adoption of age-appropriate formulations in India are (1) awareness of importance of appropriate administration and acceptability of medicines to children in India, (2) availability of age-appropriate dosage forms and (3) lack of child-appropriate medicine policies

European Paediatric Formulation Initiative workshop report: Improving the administration of oral liquid medicines in paediatrics using dosing syringes and enteral accessories

Accurate dosing of the right medicine to the right patient is a key element of safe and efficacious pharmacotherapy, yet prone to technical challenges and human error when dosing involves the administration of small volumes of liquid medicines. For this reason, the topic has gained increased attention over the last decade from multiple stakeholder parties e.g. academia, hospital pharmacy, the medical device and pharmaceutical industry, and regulatory agencies. It is now well acknowledged that spoons and cups are not suitable for the measurement of small volumes of oral liquid medicines and that syringes are a better alternative, but syringes for parenteral use should not be used for oral dosing in order to avoid accidental parenteral delivery of oral products. However, dosing accuracy of very small volumes of liquid medicines to young children, and especially pre-term neonates, is still not sufficiently ensured. A workshop was organised in 2018 by the European Paediatric Formulation Initiative to reflect on current status and challenges (first part) and possible strategies to improve the present situation (second part). A voting system (n = 24) was used to consider the most favourable solutions. The harmonisation and/or standardisation of the technical design of oral syringes (including e.g. female/male connection) was considered a key priority

Design and Development of Stable, Water-soluble, Human Toll-like Receptor 2-Specific, Monoacyl Lipopeptides as Candidate Vaccine Adjuvants

Antigens in modern subunit vaccines are largely soluble and poorly immunogenic proteins inducing relatively short-lived immune responses. Appropriate adjuvants initiate early innate immune responses, amplifying subsequent adaptive immune responses. Agonists of TLR2 are devoid of significant pro-inflammatory activity in ex vivo human blood models, and yet potently adjuvantic, suggesting that this chemotype may be a safe and effective adjuvant. Our earlier work on the monoacyl lipopeptide class of TLR2 agonists led to the design of a highly potent lead, but with negligible aqueous solubility, necessitating the reintroduction of aqueous solubility. We explored several strategies of introducing ionizable groups on the lipopeptide, as well as the systematic evaluation of chemically stable bioisosteres of the ester-linked palmitoyl group. These studies have led to a fully optimized, chemically stable, and highly water-soluble, human TLR2-specific agonist, which was found to have an excellent safety profile and displayed prominent adjuvantic activities in rabbit models

Drug utilization study in a neonatal intensive care unit of a government tertiary care hospital in Western Maharashtra

Background: Presently drug utilization studies (DUS) are in an evolving era. Current literature search has shown paucity of epidemiological studies in the field of paediatric pharmacology. Hence the present study was designed to assess the drug utilization pattern in neonatal intensive care unit to improvise the current prescription practices, if required and to determine areas in neonatal pharmacology in need of further research.Methods: A prospective, observational study spanned for a period of one year from January 2015 to December 2015 was conducted at the neonatal intensive care unit (NICU), Government teaching tertiary care hospital, Maharashtra. Data of prescribed drugs was collected. WHO prescribing indicators were used for evaluating DUS. Assessment of exposure rates of different class of drugs in different gestational age groups was done. Data were analysed using descriptive studies.Results: Data of 205 neonates, showed male preponderance (53.17%) over female neonates (46.83%). With regard to the gestational age, 47.31% were term, 52.68% preterm. Average number of drugs per encounter was 6.69. 76.29% drugs were prescribed by generic name and 69.80 % drugs were from IAP list of essential medicines for children. Mean drug use was 6.23±3.34 per patient. Most common class of drug to which neonates were exposed was antibiotics (96.10%) and amikacin topped the list with exposure rate of 91.22%.Conclusions: The present study substantiates the need for implementation of institutional antibiotic policies, awareness regarding IAP list of essential drugs for children, prescription by generic name and rational drug use

An augmented space recursion study of the electronic structure of rough epitaxial overlayers

In this communication we propose the use of the Augmented Space Recursion as an ideal methodology for the study of electronic and magnetic structures of rough surfaces, interfaces and overlayers. The method can take into account roughness, short-ranged clustering effects, surface dilatation and interdiffusion. We illustrate our method by an application of Fe overlayer on Ag (100) surface.Comment: 22 pages, Latex, 6 postscript figure