Study of the photovoltaic effect in thin film barium titanate

The photoelectric effect in structures consisting of metal deposited barium titanate film silicon is described. A radio frequency sputtering technique is used to deposit ferroelectric barium titantate films on silicon and quartz. Film properties are measured and correlated with the photoelectric effect characteristics of the films. It was found that to obtain good quality pin hole free films, it is necessary to reduce the substrate temperature during the last part of the deposition. The switching ability of the device with internal applied voltage is improved when applied with a ferroelectric memory device

Plasmodium-infected red blood cells exhibit enhanced rolling independent of host cells and alter flow of uninfected red cells

The pathogenicity of Plasmodium falciparum results from its unique ability to adhere to endothelium and uninfected erythrocytes. It is, therefore, important to understand the events leading to flowing blood cells undergoing such adhesion. Largely based on the leukocyte adhesion model, it is postulated that the slowing down (rolling) of Plasmodium-infected red blood cells (PRBCs) is initiated by interactions between certain host adhesion molecules and the parasite proteins. In this article we present data demonstrating that PRBCs do not require the presence of host adhesion molecules to slow down and roll. In a synchronized culture, the proportion of slow-flowing cells increased with parasite development and was highest at the trophozoite stage. We also observed that the uninfected red cells (URBCs), originating from a parasite culture containing PRBCs, were also inherently slower compared to malaria-unexposed normal red blood cells (NRBCs). NRBCs became slower upon incubation with supernatant taken from a parasite culture. However, such an effect was transient and the NRBCs reverted to their normal flow speed within 12 h upon withdrawal of culture supernatant. Based on our observations, we suggest that the higher propensity of PRBCs and URBCs to slow down is due to inherent structural anisotropy and altered membrane rigidity. Thus the initial events leading to the slowing down of malaria-infected blood cells appear to be different from those occurring during leukocyte adhesion

Building the Iowa wine culture through improved quality

Iowa’s first “State of the Viticulture Industry” quality report was prepared by the ISU Extension Value Added Agriculture Program and the Midwest Grape and Wine Industry Institute to identify quality benchmarks for the industry

Let's not forget plants.

'Many physicists see the interface with biology as an exciting place to be'. Athene Donald provides a personal perspective on working at the interface between the physical and biological sciences.This is the accepted manuscript. The final version is available from IOP at http://iopscience.iop.org/1478-3975/11/5/053008

Human Rad52 binding renders ssDNA unfolded: image and contour length analyses by Atomic Force Microscopy

Atomic force microscopy imaging has been used to study the changes associated with human Rad52 (HsRad52) protein in solution, in dried state as well as following ssDNA (linear and circular) binding. In the dried state, the free protein exists predominantly as a characteristic panoply of novel trifoliate forms. However, in solution, the level of trifoliates diminishes significantly. Height analyses of either form reveal two categories: smaller (~ 3-5 nm) and larger ((~ 10-12 nm) particles, perhaps related to sub-heptameric and heptameric forms respectively. Interestingly, binding of the protein to linear ssDNA smoothly extends and unfolds the naked DNA. Contour length measurements performed on several individual circular ssDNA/nucleoprotein complexes reveal marked (about threefold) extension of naked ssDNA, following HsRad52 binding. We speculate that the alignment of HsRad52 on ssDNA into a smoothly extended and unfolded strand from that of highly compact morphology of naked ssDNA, may have bearing on the recombination function of HsRad52 protein

Euler buckling in red blood cells: An optically driven biological micromotor

We investigate the physics of an optically-driven micromotor of biological origin. A single, live red blood cell, when placed in an optical trap folds into a rod-like shape. If the trapping laser beam is circularly polarized, the folded RBC rotates. A model based on the concept of buckling instabilities captures the folding phenomenon; the rotation of the cell is simply understood using the Poincar\`e sphere. Our model predicts that (i) at a critical intensity of the trapping beam the RBC shape undergoes large fluctuations and (ii) the torque is proportional to the intensity of the laser beam. These predictions have been tested experimentally. We suggest a possible mechanism for emergence of birefringent properties in the RBC in the folded state

Knowledge, attitude, and practice among healthcare professionals of adverse drug reactions reporting in a tertiary care center

Background: There has been a rapid increase in the number of drugs entering the market from last few decades. Preclinical and clinical data are insufficient to conclude the complete safety of drugs. Hence, it is necessary to have a robust pharmacovigilance system in place to generate safety signals. Under reporting of adverse drug reactions (ADRs) exists as an inherent weakness of current voluntary reporting scheme. This study was therefore taken up, to evaluate the knowledge, attitude, and practice about ADR reporting among doctors in a tertiary care center.Methods: The present study was a cross-sectional questionnaire-based study, which included prescribers of a tertiary care teaching hospital. We tried to find out the possible ways to improve reporting of ADR and factors responsible for deficient reporting of ADRs.Results: After analyzing the data, we observed that 59% of the responders were aware of the ADRs reporting system. And the most encouraging finding was 94% of the respondents think that this reporting system is necessary. However, the practice was very poor just 14% among the respondents. 74% and 61% of participants felt creating awareness among healthcare professionals, and training to healthcare professionals would lead to improvement in reporting of ADRs respectively. Main factors which discouraged ADR reporting by healthcare professionals were reporting would lead to extra work 70.5%, non-availability of forms 64.5%.Conclusion: The deficiencies in ADR reporting require attention so as to improve spontaneous reporting and enhance safety of patients