Critical Design Criterion for Achieving Zero Voltage Switching in Inductorless Half-Bridge-Driven Piezoelectric-Transformer-Based Power Supplies

A methodology for predicting the ability of inductor-less driven piezoelectric transformer (PT) based power supplies to achieve zero voltage switching (ZVS) is presented. A describing function approach is used to derive an equivalent circuit model of the PT operating in the vicinity of ZVS and the subsequent application of the model provides a quantitative measure of a PT's ability to achieve ZVS when driven by an inductor-less half-bridge inverter. Through detailed analysis of the analytical model, the limitations of the inductor-less half-bridge driven PT are exposed from which guidelines for designing both the PT and inverter are derived

B2: Presence of Immunosuppressive Drugs affect Innate Immune Response and Monocyte Differentiation in Lung Transplant Patients

Lung transplant patients are administered Immunosuppressive Drugs (ISDs) to prevent transplant rejection, but this also puts them at constant risk of infection due to the decreased ability of the immune system to respond to subsequent infections by viruses, bacteria etc. Purpose This paper focuses on the effect of ISDs on the innate immune response. We are using different parts of viruses and bacteria and allowing them to represent the organism as a whole. Methods As representatives of the innate immune system, we are going to be testing monocyte, macrophage, and dendritic cell lineages. We are hypothesizing that the presence of ISDs dampens the immune system response to viruses/bacteria as well as that in the presence of ISDs, there is decreased differentiation of the monocytes into macrophages. We used PCR and Flow cytometry to help interpret the data. PCR allowed us to recognize innate immune transcriptional changes of the cells that were treated with ISDs in comparison to the control. We used the Flow Cytometer to test monocyte differentiation into macrophages. Results The results showed that there were certain innate immune genes that showed increase in expression, some showed decrease, while others showed no change in the presence of ISDs. It was also concluded that the presence of ISDs actually induced differentiation of Monocytes into Macrophages. Conclusion This information can be used to manipulate the immune systems of lung transplant patients to better respond to specific subsequent infections even in the presence of Immunosuppressive Drugs while still maintaining the integrity of the transplant

Heliospheric Transport of Neutron-Decay Protons

We report on new simulations of the transport of energetic protons originating from the decay of energetic neutrons produced in solar flares. Because the neutrons are fast-moving but insensitive to the solar wind magnetic field, the decay protons are produced over a wide region of space, and they should be detectable by current instruments over a broad range of longitudes for many hours after a sufficiently large gamma-ray flare. Spacecraft closer to the Sun are expected to see orders-of magnitude higher intensities than those at the Earth-Sun distance. The current solar cycle should present an excellent opportunity to observe neutron-decay protons with multiple spacecraft over different heliographic longitudes and distances from the Sun.Comment: 12 pages, 4 figures, to be published in special issue of Solar Physic

Closing five Emergency Departments in England between 2009 and 2011: the closED controlled interrupted time-series analysis

Background In recent years, a number of emergency departments (EDs) have closed or have been replaced by another facility such as an urgent care centre. With further reorganisation of EDs expected, this study aimed to provide research evidence to inform the public, the NHS and policy-makers when considering local closures. Objective To understand the impact of ED closures/downgrades on populations and emergency care providers. Design A controlled interrupted time series of monthly data to assess changes in the patterns of mortality in local populations and changes in local emergency care service activity and performance, following the closure of type 1 EDs. Setting The populations of interest were in the resident catchment areas of five EDs that closed between 2009 and 2011 (in Newark, Hemel Hempstead, Bishop Auckland, Hartlepool and Rochdale) and of five control areas. Main outcome measures The primary outcome measures were ambulance service incident volumes and times, the number of emergency and urgent care attendances at EDs, the number of emergency hospital admissions, mortality, and case fatality ratios. Data sources Data were sourced from the Office for National Statistics, Hospital Episode Statistics (HES) accident and emergency, HES admitted patient care and ambulance service computer-aided dispatch records. Results There was significant heterogeneity among sites in the results for most of the outcome measures, but the overall findings were as follows: there is evidence of an increase, on average, in the total number of incidents attended by an ambulance following 999 calls, and those categorised as potentially serious emergency incidents; there is no statistically reliable evidence of changes in the number of attendances at emergency or urgent care services or emergency hospital admissions; there is no statistically reliable evidence of any change in the number of deaths from a set of emergency conditions following the ED closure in any site, although, on average, there was a small increase in an indicator of the ‘risk of death’ in the closure areas compared with the control areas. Limitations Unavailable or unreliable data hindered some of the analysis regarding ED and ambulance service performance. Conclusions Overall, across the five areas studied, there was no statistically reliable evidence that the reorganisation of emergency care was associated with an increase in population mortality. This suggests that any negative effects caused by increased journey time to the ED can be offset by other factors; for example, if other new services are introduced and care becomes more effective than it used to be, or if the care received at the now-nearest hospital is more effective than that provided at the hospital where the ED closed. However, there may be implications of reorganisation for NHS emergency care providers, with ambulance services appearing to experience a greater burden. Future work Understanding why effects vary between sites is necessary. It is also necessary to understand the impact on patient experience. Economic evaluation to understand the cost implications of such reorganisation is also desirable

Long-term reduction in 137Cs concentration in food crops on coral atolls resulting from potassium treatment

Bikini Island was contaminated March 1, 1954 by the Bravo detonation (U.S nuclear test series, Castle) at Bikini Atoll. About 90% of the estimated dose from nuclear fallout to potential island residents is from cesium-137 ({sup 137}Cs) transferred from soil to plants that are consumed by residents. Thus, radioecology research efforts have been focused on removing {sup 137}Cs from soil and/or reducing its uptake into vegetation. Most effective was addition of potassium (K) to soil that reduces {sup 137}Cs concentration in fruits to 3-5% of pretreatment concentrations. Initial observations indicated this low concentration continued for some time after K was last applied. Long-term studies were designed to evaluate this persistence in more detail because it is very important to provide assurance to returning populations that {sup 137}Cs concentrations in food (and, therefore, radiation dose) will remain low for extended periods, even if K is not applied annually or biennially. Potassium applied at 300, 660, 1260, and 1970 kg ha{sup -1} lead to a {sup 137}Cs concentration in drinking coconut meat that is 34, 22, 10, and about 4 % of original concentration, respectively. Concentration of {sup 137}Cs remains low 8 to 10 y after K is last applied. An explanation for this unexpected result is discussed

Prior dengue virus exposure shapes T Cell immunity to Zika Virus in humans

While progress has been made in characterizing humoral immunity to Zika virus (ZIKV) in humans, little is known regarding the corresponding T cell responses to ZIKV. Here we investigate the kinetics and viral epitopes targeted by T cells responding to ZIKV and address the critical question of whether pre-existing dengue virus (DENV) T cell immunity modulates these responses. We find that memory T cell responses elicited by prior infection with DENV or vaccination with Tetravalent Dengue Attenuated Vaccines (TDLAV) recognize ZIKV-derived peptides. This cross-reactivity is explained by the sequence similarity of the two viruses, as the ZIKV peptides recognized by DENV-elicited memory T cells are identical or highly conserved in DENV and ZIKV. DENV exposure prior to ZIKV infection also influences the timing and magnitude of the T cell response. ZIKV-reactive T cells in the acute phase of infection are detected earlier and in greater magnitude in DENV-immune patients. Conversely, the frequency of ZIKV-reactive T cells continues to rise in the convalescent phase in DENV-naive donors, but declines in DENV pre-exposed donors, compatible with more efficient control of ZIKV replication and/or clearance of ZIKV antigen. The quality of responses is also influenced by previous DENV exposure, and ZIKV-specific CD8 T cells form DENV pre-exposed donors selectively up-regulated granzyme B and PD1, as compared to DENV-naïve donors. Finally, we discovered that ZIKV structural proteins (E, prM and C) are major targets of both the CD4 and CD8 T cell responses, whereas DENV T cell epitopes are found primarily in nonstructural proteins

Hepatitis C Virus Infection Induces Autocrine Interferon Signaling by Human Liver Endothelial Cells and Release of Exosomes, Which Inhibits Viral Replication

Liver sinusoidal endothelial cells (LSECs) make up a large proportion of the non-parenchymal cells in the liver. LSECs are involved in induction of immune tolerance, but little is known about their functions during hepatitis C virus (HCV) infection