Primary and secondary pyroelectric effects of ferroelectric 0-3 composites

Author name used in this publication: F. G. ShinAuthor name used in this publication: B. PlossAuthor name used in this publication: H. L. W. Chan2003-2004 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

The effect of Fe substitution on pyroelectric properties of 0.62Pb(Mg[sub ⅓]Nb[sub ⅔])O₃-0.38PbTiO₃ single crystals

Version of RecordPublishe

Quantitative principles of cis-translational control by general mRNA sequence features in eukaryotes.

BackgroundGeneral translational cis-elements are present in the mRNAs of all genes and affect the recruitment, assembly, and progress of preinitiation complexes and the ribosome under many physiological states. These elements include mRNA folding, upstream open reading frames, specific nucleotides flanking the initiating AUG codon, protein coding sequence length, and codon usage. The quantitative contributions of these sequence features and how and why they coordinate to control translation rates are not well understood.ResultsHere, we show that these sequence features specify 42-81% of the variance in translation rates in Saccharomyces cerevisiae, Schizosaccharomyces pombe, Arabidopsis thaliana, Mus musculus, and Homo sapiens. We establish that control by RNA secondary structure is chiefly mediated by highly folded 25-60 nucleotide segments within mRNA 5' regions, that changes in tri-nucleotide frequencies between highly and poorly translated 5' regions are correlated between all species, and that control by distinct biochemical processes is extensively correlated as is regulation by a single process acting in different parts of the same mRNA.ConclusionsOur work shows that general features control a much larger fraction of the variance in translation rates than previously realized. We provide a more detailed and accurate understanding of the aspects of RNA structure that directs translation in diverse eukaryotes. In addition, we note that the strongly correlated regulation between and within cis-control features will cause more even densities of translational complexes along each mRNA and therefore more efficient use of the translation machinery by the cell

Influence of long-range dipolar interactions on the phase stability and hysteresis shapes of ferroelectric and antiferroelectric multilayers

Phase transition and field driven hysteresis evolution of a two-dimensional Ising grid consisting of ferroelectric-antiferroelectric multilayers that take into account the long range dipolar interactions were simulated by a Monte-Carlo method. Simulations were carried out for a 1+1 bilayer and a 5+5 superlattice. Phase stabilities of components comprising the structures with an electrostatic-like coupling term were also studied. An electrostatic-like coupling, in the absence of an applied field, can drive the ferroelectric layers towards 180º domains with very flat domain interfaces mainly due to the competition between this term and the dipole-dipole interaction. The antiferroelectric layers do not undergo an antiferroelectric-to-ferroelectric transition under the influence of an electrostatic-like coupling between layers as the ferroelectric layer splits into periodic domains at the expense of the domain wall energy. The long-range interactions become significant near the interfaces. For high periodicity structures with several interfaces, the interlayer long-range interactions substantially impact the configuration of the ferroelectric layers while the antiferroelectric layers remain quite stable unless these layers are near the Neel temperature. In systems investigated with several interfaces, the hysteresis loops do not exhibit a clear presence of antiferroelectricity that could be expected in the presence of anti-parallel dipoles, i. e., the switching takes place abruptly. Some recent experimental observations in ferroelectric-antiferroelectric multilayers are discussed where we conclude that the different electrical properties of bilayers and superlattices are not only due to strain effects alone but also long-range interactions. The latter manifests itself particularly in superlattices where layers are periodically exposed to each other at the interfaces

Clostridium septicum sepsis and colorectal cancer - a reminder

<p>Abstract</p> <p>Background</p> <p>Spontaneous clostridium septicum infections are rare and are associated with a high mortality. Association of clostridium infection with colorectal malignancies have been previously reported and most cases are described in tumours of the ascending colon. We report our experience of clostridium septicum infection in the presence of tumour perforation in a series of two patients as a reminder of its association with sepsis in the presence of colorectal malignancy.</p> <p>Case Presentation</p> <p>We isolated clostridium septicum infection in a series of two patients admitted as emergencies. One patient was found to have a perforated caecal tumour intraoperatively whilst the other had a perforated rectal tumour. The clinical outcome and management of each case are reported and underlying reasons for variations in outcome are discussed.</p> <p>Conclusion</p> <p>Although uncomman, the possibility of clostridium septicum sepsis should be borne in mind in patients who present with underlying malignancy and have sepsis. The cumulative effect of sepsis and malignant perforation is associated with a high morbidity and mortality. Awareness and early diagnosis of clostridium septicum may improve the prognosis of what is usually regarded as a fatal infection.</p

The paradox of screening: Rural women's views on screening for postnatal depression

<p>Abstract</p> <p>Background</p> <p>Universal screening for postnatal depression is currently being promoted in Australia to assist detection and treatment of affected women, yet debate continues internationally about the effectiveness of screening. One rural shire in Victoria has been screening all women for postnatal depression at maternal and child health checks for many years. This paper explores the views of women affected by this intervention.</p> <p>Methods</p> <p>A postal survey was sent to an entire one year cohort of women resident in the shire and eligible for this program [n = 230]. Women were asked whether they recalled having been screened for postnatal depression and what their experience had been, including any referrals made as a result of screening. Women interested in providing additional information were invited to give a phone number for further contact. Twenty women were interviewed in-depth about their experiences. The interview sample was selected to include both depressed and non-depressed women living in town and on rural properties, who represented the range of circumstances of women living in the shire.</p> <p>Results</p> <p>The return rate for the postal survey was 62% [n = 147/230]. Eighty-seven women indicated that they were interested in further contact, 80 of whom were able to be reached by telephone and 20 were interviewed in-depth. Women had diverse views and experiences of screening. The EPDS proved to be a barrier for some women, and a facilitator for others, in accessing support and referrals. The mediating factor appeared to be a trusting relationship with the nurse able to communicate her concern for the woman and offer support and referrals if required.</p> <p>Conclusions</p> <p>Detection of maternal depression requires more than administration of a screening tool at a single time point. While this approach did work for some women, for others it actually made appropriate care and support more difficult. Rather, trained and empathic healthcare providers working in a coordinated primary care service should provide multiple and flexible opportunities for women to disclose and discuss their emotional health issues.</p

Risk factors for severe hand foot mouth disease in Singapore: a case control study

BACKGROUND: Hand foot mouth disease (HFMD) is a common childhood infection that can potentially lead to serious complications. The aim of this study is to identify risk factors of acquiring severe HFMD in our population. METHODS: We performed a case control study using patients admitted to our hospital from August 2004 to July 2014. Cases were patients with severe HFMD disease while controls were age-matched patients obtained from the same year, in a 2:1 ratio. Data comprising demographic characteristics, clinical symptoms and signs, and lab findings were collected. Conditional univariable logistic regression was performed to determine risk factors for severe disease. RESULTS: A total of 24 cases of severe HFMD were identified and matched with 48 controls. Seventeen (70.8 %) cases had central nervous system complications. Seven (29.2 %) had cardiovascular complications without evidence of myocarditis. One patient died of encephalitis. The overall mortality of severe disease is 4 %. Evidence of hypoperfusion, seizure, altered mentation, meningeal irritation, tachycardia, tachypnea, raised absolute neutrophil count and EV-A71 (Enterovirus A71) positivity were significantly associated with a severe course of HFMD. CONCLUSION: In managing children with HFMD, physicians should consider these factors to help identify patients at risk for severe disease

Validation of pooled genotyping on the Affymetrix 500 k and SNP6.0 genotyping platforms using the polynomial-based probe-specific correction

10.1186/1471-2156-10-82BMC Genetics10-BGME

LIM and SH3 Protein -1 Modulates CXCR2-Mediated Cell Migration

BACKGROUND: The chemokine receptor CXCR2 plays a pivotal role in migration of neutrophils, macrophages and endothelial cells, modulating several biological responses such as angiogenesis, wound healing and acute inflammation. CXCR2 is also involved in pathogenesis of chronic inflammation, sepsis and atherosclerosis. The ability of CXCR2 to associate with a variety of proteins dynamically is responsible for its effects on directed cell migration or chemotaxis. The dynamic network of such CXCR2 binding proteins is termed as "CXCR2 chemosynapse". Proteomic analysis of proteins that co-immunoprecipitated with CXCR2 in neutrophil-like dHL-60 cells revealed a novel protein, LIM and SH3 protein 1 (LASP-1), binds CXCR2 under both basal and ligand activated conditions. LASP-1 is an actin binding cytoskeletal protein, involved in the cell migration. METHODOLOGY/PRINCIPAL FINDINGS: We demonstrate that CXCR2 and LASP-1 co-immunoprecipitate and co-localize at the leading edge of migrating cells. The LIM domain of LASP-1 directly binds to the carboxy-terminal domain (CTD) of CXCR2. Moreover, LASP-1 also directly binds the CTD of CXCR1, CXCR3 and CXCR4. Using a site-directed and deletion mutagenesis approach, Iso323-Leu324 of the conserved LKIL motif on CXCR2-CTD was identified as the binding site for LASP-1. Interruption of the interaction between CXCR2-CTD and LIM domain of LASP-1 by dominant negative and knock down approaches inhibited CXCR2-mediated chemotaxis. Analysis for the mechanism for inhibition of CXCR2-mediated chemotaxis indicated that LASP-1/CXCR2 interaction is essential for cell motility and focal adhesion turnover involving activation of Src, paxillin, PAK1, p130CAS and ERK1/2. CONCLUSIONS/SIGNIFICANCE: We demonstrate here for the first time that LASP-1 is a key component of the "CXCR2 chemosynapse" and LASP-1 interaction with CXCR2 is critical for CXCR2-mediated chemotaxis. Furthermore, LASP-1 also directly binds the CTD of CXCR1, CXCR3 and CXCR4, suggesting that LASP-1 is a general mediator of CXC chemokine mediated chemotaxis. Thus, LASP-1 may serve as a new link coordinating the flow of information between chemokine receptors and nascent focal adhesions, especially at the leading edge. Thus the association between the chemokine receptors and LASP-1 suggests to the presence of a CXC chemokine receptor-LASP-1 pro-migratory module in cells governing the cell migration