Exchange bias-like magnetic properties in Sr2LuRuO6

Exchange bias properties are observed in a double perovskite compound, Sr2LuRuO6. The observed exchange bias properties have been analyzed on the basis of some of the available theoretical models. Detailed magnetization measurements show that the exchange bias properties are associated with the Dzyaloshinsky-Moria (D-M) interaction among the antiferromagnetically ordered Ru moments (TN~32K). In addition to the usual canting of the antiferromagnetic moments, D-M interaction in this compound also causes a magnetization reversal at T~26K, which seems to trigger the exchange bias properties. Heat capacity measurements confirm the two magnetic anomalies.Comment: 5 Pages, 6 Figure

Isolation and Biomedical Screening of the Tissue Extracts of Two Marine Gastropods Hemifusus pugilinus (Born, 1778) and Natica didyma (Roding, 1798)

The in vitro antibacterial activity of the acetone and methanol extracts of the marine gastropods Hemifusus pugilinus (Born, 1778) and Natica didyma (Roding, 1798) were tested against Escherichia coli, Staphylococcus aureus, Bacillus subtilis and Enterobacter aerogenes following standard disc diffusion method. Highest activity (19.3±0.39 mm) was observed in the methanol extract of N. didyma against E. coli. The extracts were also subjected to anti-inflammatory activity using human red blood cell (HRBC) membrane stabilisation method. All the extracts exhibited antiinflammatory activity, and was high in the acetone extract of H. pugilinus (72.58±1.66%) at 1mL concentration. However, the control drug hydrocortisone exhibited significantly higher activity than the tissue extracts of both the animals. The extracts were screened for their alpha amylase inhibitory activity also and all the extracts inhibited the alpha amylase enzyme activity. Among the mollusc extracts, maximum inhibition was observed in H. pugilinus acetone extract at 50 μL concentration (72.23±0.44%). But, the control drug (Acarbose) had significantly higher inhibitory action than the tissue extracts of both the animals. The amount of protein was comparatively high in the tissue of both H. pugilinus (1.34±5.63 μg.mL-1) and N. didyma (0.90±4.37 μg.mL-1) than carbohydrates and lipids

Investigational synthetic neuroactive steroid zuranolone in treatment of major depressive disorder with peripartum onset

Major depressive disorder with peripartum onset or peripartum depression is a common condition experienced by a large proportion of women and to some extent even in men. The current treatment strategies involve the use of conventional pharmacotherapeutic classes of drugs like selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs) and psychotherapy methods in the management of this condition. In this article, we try to review and evaluate the pathophysiology of the condition along with the safety and efficacy of the novel investigational therapeutic drug zuranolone, which is a synthetic neuroactive steroid (NAS) that has shown promise in clinical trials for the management of conditions like major depressive disorder, peripartum depression and bipolar disorder. The synthetic NAS zuranolone is an orally bioavailable positive allosteric modulator of the gamma amino butyric acid (GABAA) receptor, which can regulate the action of the GABAergic pathway implicated in many depressive episodes and also affect the normal functioning of the hypothalmo pituitary-adrenal (HPA) axis which is the core pathophysiological cause behind major depressive disorder with peripartum onset

Large area silicon sheet by EFG

Progress in a program to produce high speed, thin, wide silicon sheets for fabricating 10% efficient solar cells is reported. An EFG ribbon growth system was used to perform growth rate and ribbon thickness experiments. A new, wide ribbon growth system was developed. A theoretical study of stresses in ribbons was also conducted. The EFG ribbons were observed to exhibit a characteristic defect structure which is orientation dependent in the early stages of growth

Observation of magnetization reversal and negative magnetization in a double perovskite compound Sr2YbRuO6

Detailed magnetic properties of the compound Sr2YbRuO6 are presented here. The compound belongs to the family of double perovskites forming a monoclinic structure. Magnetization meas-urements reveal clear evidence for two components of magnetic ordering aligned opposite to each other, leading to a magnetization reversal, compensation temperature (T* = 34 K) and neg-ative magnetization at low temperatures and low magnetic fields. Heat capacity measurements corroborate the presence of two components in the magnetic ordering and a noticeable third anomaly at low temperatures (~15 K) which cannot be attributed the Schottky effect. The calcu-lated magnetic entropy is substantially lower than that expected for the ground states of the or-dered moments of Ru5+ and Yb3+, indicating the presence of large crystal field effects and/ or in-complete magnetic ordering and/or magnetic frustrations well above the magnetic ordering. An attempt is made to explain the magnetization reversal within the frameworks of available models.Comment: 15 pages text, 6 figures Journal-ref: J.Phys.:Condens.Matter 20(2008)23520