Formation of InAs Self-Assembled Quantum Rings on InP

Shape transformations of partially capped self-assembled InAs quantum dots grown on InP are studied. Atomic force microscopy images show large anisotropic redistribution of the island material after coverage by a 1 nm thick InP layer. The anisotropic material redistribution occurs within a few minutes and leads to a change from lens-like to elongated ring-like islands. The shape transformation is not accompanied by dot material compositional change. The formation of InAs/InP quantum rings disagrees with a previous model of InAs/GaAs ring formation that assumes that the driving force for the dot to ring transformation is the difference in surface diffusion velocity of indium and gallium atoms.Comment: 13 pages, including 2 figures and 1 table. Submitted to Appl. Phys. Let

The quantum efficiency of HgCdTe photodiodes in relation to the direction of illumination and to their geometry

A theoretical study of the effect of the direction of the incident light on the quantum efficiency of homogeneous HgCdTe photodiodes suitable for sensing infrared radiation in the 8-12 microns atmospheric window is presented. The probability of an excess minority carrier to reach the junction is derived as a function of its distance from the edge of the depletion region. Accordingly, the quantum efficiency of photodiodes is presented for two geometries. In the first, the light is introduced directly to the area in which it is absorbed (opaque region), while in the second, the light passes through a transparent region before it reaches the opaque region. Finally, the performance of the two types of diodes is analyzed with the objective of finding the optimal width of the absorption area. The quantum efficiency depends strongly on the way in which the light is introduced. The structure in which the radiation is absorbed following its crossing the transparent region is associated with both higher quantum efficiency and homogeneity. In addition, for absorption region widths higher than a certain minimum, the quantum efficiency in this case is insensitive to the width of the absorption region

Knowledge, attitude and practice of progestin-only emergency contraceptives among female students of Jimma Teachers Training College, Jimma, Ethiopia

Background: Emergency contraception (EC) is the safest strategy for prevention of unintended pregnancy following unsafe sex provided that users have sufficient knowledge & awareness of EC. Objective: The main objective of this study was to assess the knowledge, attitude, and practice of progestin-only emergency contraceptives. Methods: Retrospective cross-sectional study was conducted from February 16 to April 18, 2017, among students of Jimma teacher’s training college. Chi-square test was run to identify the association between variables. Variables with the critical value P<0.05 at CI of 95% were considered as statistically significant.Results: A total of 270 female students were involved in the study; of which 53.70% of them had knowledge about ECs. A significant association was found between knowledge on ECs & age distribution (p<0.001) and also the sexual activity of the participants (p=0.013).More than half of the respondents agreed that widespread use of ECs would increase the prevalence of HIV/ AIDS and other sexually transmitted diseases (STIs). Of the total study participants, 121 (44.81%) have used ECs and the utilization practice has a significant association with age distribution (p<0.001 and religion of the study participants (p=0.002).   Conclusion: Generally, nearly half of the study participants had knowledge about ECs and used EC at least once in their lifetime. Most of the students agreed that relying on EC pills and its accessibility would promote the spread of HIV/AIDS and STIs.  Funding: The study was conducted with the financial support of Jimma UniversityKeywords: Knowledge, emergency contraceptives, attitude, practic

Effect of some anticancer drugs on the growth of children with Acute Lymphoblastic Leukemia in Iraq

Acute Lymphoblastic Leukemia (ALL) is the most common type of leukemia in children. It represents about 75% of all leukemia types in children less than 15 years old and peak incidence at (2-5) years old. The study was designed to evaluate the effect of chemotherapeutic regimens used for Iraqi children with ALL by assessing anthropometric parameters, oxidative state markers, and metabolic state. This prospective randomized clinical study was carried out on (30) newly diagnosed children with ALL (6 months – 8 years old) in Iraq. According to the FAB-classification, the patients grouped as L1 group (n=16) and L2 group (n=14). A healthy children (n=14) were involved and considered as a control group to compare their normal data with these of patients groups. The IGF-I, albumin, total serum protein, BMI, TAS, and LDH were determined at baseline, 1st, 2nd, and 3rd months of the treatment regimen. The results showed that the mean level of serum IGF-I in both patient groups was significantly lower than that of control children at baseline, and it is increased significantly after receiving treatment while no significance difference between patients of both groups. Serum albumin, total serum protein, and BMI showed no significant differences in both patient groups when compared with the control group at baseline and after receiving treatment, also, between patients of both groups. TAS showed a significant reduction at baseline and after receiving treatment of both patients’ groups when compared with the control children, and there was a significant difference between patients of both groups. For LDH, there was a significant elevation in the mean level at baseline for both patients’ groups when compared with the control children, while after receiving treatment a significant reduction noticed in both groups when compared with control children and no significance difference between patients of both groups. These results can give indication for the effect of chemotherapy on the growth and nutrition of ALL children through their effects on IGF-I, which has a direct effect on GH and the reduction in the levels of total proteins and albumin, which may affect BMI, while the reduction in TAS during chemotherapy treatment may result in disruption of cells metabolism which will affect the normal body homeostasis. Keywords: ALL, Growth, IGF-I, Chemotherapy

A predictor for toxin-like proteins exposes cell modulator candidates within viral genomes

Motivation: Animal toxins operate by binding to receptors and ion channels. These proteins are short and vary in sequence, structure and function. Sporadic discoveries have also revealed endogenous toxin-like proteins in non-venomous organisms. Viral proteins are the largest group of quickly evolving proteomes. We tested the hypothesis that toxin-like proteins exist in viruses and that they act to modulate functions of their hosts

DOMMINO: a database of macromolecular interactions

With the growing number of experimentally resolved structures of macromolecular complexes, it becomes clear that the interactions that involve protein structures are mediated not only by the protein domains, but also by various non-structured regions, such as interdomain linkers, or terminal sequences. Here, we present DOMMINO (http://dommino.org), a comprehensive database of macromolecular interactions that includes the interactions between protein domains, interdomain linkers, N- and C-terminal regions and protein peptides. The database complements SCOP domain annotations with domain predictions by SUPERFAMILY and is automatically updated every week. The database interface is designed to provide the user with a three-stage pipeline to study macromolecular interactions: (i) a flexible search that can include a PDB ID, type of interaction, SCOP family of interacting proteins, organism name, interaction keyword and a minimal threshold on the number of contact pairs; (ii) visualization of subunit interaction network, where the user can investigate the types of interactions within a macromolecular assembly; and (iii) visualization of an interface structure between any pair of the interacting subunits, where the user can highlight several different types of residues within the interfaces as well as study the structure of the corresponding binary complex of subunits

GeneCards Version 3: the human gene integrator

GeneCards (www.genecards.org) is a comprehensive, authoritative compendium of annotative information about human genes, widely used for nearly 15 years. Its gene-centric content is automatically mined and integrated from over 80 digital sources, resulting in a web-based deep-linked card for each of >73 000 human gene entries, encompassing the following categories: protein coding, pseudogene, RNA gene, genetic locus, cluster and uncategorized. We now introduce GeneCards Version 3, featuring a speedy and sophisticated search engine and a revamped, technologically enabling infrastructure, catering to the expanding needs of biomedical researchers. A key focus is on gene-set analyses, which leverage GeneCards’ unique wealth of combinatorial annotations. These include the GeneALaCart batch query facility, which tabulates user-selected annotations for multiple genes and GeneDecks, which identifies similar genes with shared annotations, and finds set-shared annotations by descriptor enrichment analysis. Such set-centric features address a host of applications, including microarray data analysis, cross-database annotation mapping and gene-disorder associations for drug targeting. We highlight the new Version 3 database architecture, its multi-faceted search engine, and its semi-automated quality assurance system. Data enhancements include an expanded visualization of gene expression patterns in normal and cancer tissues, an integrated alternative splicing pattern display, and augmented multi-source SNPs and pathways sections. GeneCards now provides direct links to gene-related research reagents such as antibodies, recombinant proteins, DNA clones and inhibitory RNAs and features gene-related drugs and compounds lists. We also portray the GeneCards Inferred Functionality Score annotation landscape tool for scoring a gene’s functional information status. Finally, we delineate examples of applications and collaborations that have benefited from the GeneCards suite