HYBRID SERIAL-OUTPUT CONVERTER TOPOLOGY FOR VOLUME AND WEIGHT RESTRICTED LED LIGHTING APPLICATIONS

T. McRae,A. Prodi? 전력전자학회 2015 ICPE(ISPE)논문집 Vol.2015 No.6

This paper introduces a new high power density step-up LED driver converter architecture based on power processing divided between a switched capacitor (SC) converter and a flyback stage. The step up function is obtained by stacking the output of the flyback on top of the SC converter output. The high power density SC processes the majority of the power of the system and is left unregulated to maximize its efficiency. The small flyback processes only a small portion of the total power and regulates the output voltage. As a result high power efficiency, small converter volume, and tight output voltage regulation are achieved. A digital controller regulates the operation of this hybrid converter topology. In comparison with conventional boost and flyback based solutions, the new architecture drastically reduces the passive component volume and decreases peak voltage stress of switches. The paper also gives design guidelines for this topology and topologies of its kind for a given power processing efficiency target. Experimental results obtained with a 12 V to 55 V, 47W, 500 kHz prototype show that the hybrid converter has about four times smaller energy storage requirements compared to conventional solutions, while maintaining approximately the same power processing efficiency of 90%.

High polarity analytes in food - enrofloxacin and sulfadiazine in bovine tissue (CCQM-K141)

Windust, Anthony,McRae, Garnet,Meija, Juris,Mester, Zoltá,n,Melanson, Jeremy E,Croft, Meg,Johnston, Lesley,Murby, John,Rego, Eliane C P do,Violante, Fernando G M,Fernandes, Jane L N,Wollinger, W BUREAU INTERNATIONAL DES POIDS ET MESURES 2019 METROLOGIA -BERLIN- Vol.56 No.-

<P></P> <P>Within the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantitè de Matiére (CCQM), key comparison CCQM-K141 and associated pilot study CCQM-P178 were coordinated by the National Research Council Canada (NRC). This comparison was a Track A key comparison that formed part of the OAWG 10-year strategic plan. The comparison demonstrated capabilities for measuring high-polarity analytes in a high-fat and high-protein matrix. The measurand chosen as the model system was enrofloxacin and sulfadiazine in bovine tissue. Thirteen National Metrology Institutes or Designated Institutes participated in the CCQM-K141, while two National Metrology Institutes participated in CCQM-P178.</P> <P>The bovine muscle tissue study material was derived from a single live animal that was administered with chemical based pharmaceutical agents prior to processing. Therefore, the study material was naturally incurred, providing a true test of extraction procedures relative to more commonly encountered spiked materials. NRC confirmed excellent homogeneity and stability of the material prior to shipping. Three 10 g bottles of freeze dried powdered muscle tissue were supplied. NRC also provided isotopically labelled solutions of the two measurands, <SUP>13</SUP>C<SUB>6</SUB>-sulfadiazine and enrofloxacin-d<SUB>5</SUB> (HI Salt), to those interested in using isotope dilution mass spectrometry (IDMS) methodologies. Procurement and purity assignment with appropriate metrological traceability of native calibrants were the responsibility of individual participants. The study required extraction, clean-up, analytical separation, and selective detection of the analytes.</P> <P>The level of agreement was reasonable given the measurands and matrix were new for most laboratories. The KCRV values and their uncertainties at the 95% confidence level of 57.81 ± 2.57 μg/kg for enrofloxacin and 2285 ± 68 μg/kg for sulfadiazine were calculated using the DSL means. While one participant's value was voluntarily excluded from the KCRV calculations for enrofloxacin, all other participants demonstrated equivalence for both measurands.</P> <P>Significant effort was undertaken post-study to identify the major sources of variability between results. In particular, the various extraction conditions used by participants were investigated thoroughly. While there appeared to be a correlation between highly acidic conditions and higher recovery, this was not definitive and could not be confirmed. The form of standards employed (i.e. free base vs salts) and potential differential solubility between forms was also a suspected source of variability. Biases could also have been introduced with the choice of solvents used for standard preparation, with some solvents better able to minimize adsorption of the analytes to glass surfaces.</P> <P>KEY WORDS FOR SEARCH</P> <P>enrofloxacin, sulfadiazine, bovine tissue, incurred, key comparison</P> <P></P> <H2>Main text</H2> <P> To reach the main text of this paper, click on <A HREF='https://www.bipm.org/utils/common/pdf/final_reports/QM/K141/CCQM-K141.pdf'>Final Report</A>. Note that this text is that which appears in Appendix B of the BIPM key comparison database <A HREF='http://kcdb.bipm.org/'>kcdb.bipm.org/</A>.</P> <P>The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).</P>

Genome-wide average DNA methylation is determined <i>in utero</i>

Li, Shuai,Wong, Ee Ming,Dugué,, Pierre-Antoine,McRae, Allan F,Kim, Eunae,Joo, Ji-Hoon Eric,Nguyen, Tuong L,Stone, Jennifer,Dite, Gillian S,Armstrong, Nicola J,Mather, Karen A,Thalamuthu, Anbupal Oxford University Press 2018 International journal of epidemiology Vol.47 No.3

<P><B>Abstract</B></P><P><B>Background</B></P><P>Investigating the genetic and environmental causes of variation in genome-wide average DNA methylation (GWAM), a global methylation measure from the HumanMethylation450 array, might give a better understanding of genetic and environmental influences on methylation.</P><P><B>Methods</B></P><P>We measured GWAM for 2299 individuals aged 0 to 90 years from seven twin and/or family studies. We estimated familial correlations, modelled correlations with cohabitation history and fitted variance components models for GWAM.</P><P><B>Results</B></P><P>The correlation in GWAM for twin pairs was ∼0.8 at birth, decreased with age during adolescence and was constant at ∼0.4 throughout adulthood, with no evidence that twin pair correlations differed by zygosity. Non-twin first-degree relatives were correlated, from 0.17 [95% confidence interval (CI): 0.05–0.30] to 0.28 (95% CI: 0.08–0.48), except for middle-aged siblings (0.01, 95% CI: −0.10–0.12), and the correlation increased with time living together and decreased with time living apart. Spouse pairs were correlated in all studies, from 0.23 (95% CI: 0.3–0.43) to 0.31 (95% CI: 0.05–0.52), and the correlation increased with time living together. The variance explained by environmental factors shared by twins alone was 90% (95% CI: 74–95%) at birth, decreased in early life and plateaued at 28% (95% CI: 17–39%) in middle age and beyond. There was a cohabitation-related environmental component of variance.</P><P><B>Conclusions</B></P><P>GWAM is determined <I>in utero</I> by prenatal environmental factors, the effects of which persist throughout life. The variation of GWAM is also influenced by environmental factors shared by family members, as well as by individual-specific environmental factors.</P>

Validating lactate dehydrogenase (LDH) as a component of the PLASMIC predictive tool (PLASMIC-LDH)

Christopher Chin Keong Liam,Jim Yu-Hsiang Tiao,Yee Yee Yap,Yi Lin Lee,Jameela Sathar,Simon McRae,Amanda Davis,Jennifer Curnow,Robert Bird,Philip Choi,Pantep Angchaisuksiri,Sim Leng Tien,Joyce Ching Me 대한혈액학회 2023 Blood Research Vol.58 No.1

Background The PLASMIC score is a convenient tool for predicting ADAMTS13 activity of <10%. Lactate dehydrogenase (LDH) is widely used as a marker of haemolysis in thrombotic thrombocytopenic purpura (TTP) monitoring, and could be used as a replacement marker for lysis. We aimed to validate the PLASMIC score in a multi-centre Asia Pacific region, and to explore whether LDH could be used as a replacement marker for lysis. Methods Records of patients with thrombotic microangiopathy (TMA) were reviewed. Patients’ ADAMTS13 activity levels were obtained, along with clinical/laboratory findings relevant to the PLASMIC score. Both PLASMIC scores and PLASMIC-LDH scores, in which LDH replaced traditional lysis markers, were calculated. We generated a receiver operator characteristics (ROC) curve and compared the area under the curve values (AUC) to determine the predictive ability of each score. Results 46 patients fulfilled the inclusion criteria, of which 34 had ADAMTS13 activity levels of <10%. When the patients were divided into intermediate-to-high risk (scores 5‒7) and low risk (scores 0‒4), the PLASMIC score showed a sensitivity of 97.1% and specificity of 58.3%, with a positive predictive value (PPV) of 86.8% and negative predictive value (NPV) of 87.5%. The PLASMIC-LDH score had a sensitivity of 97.1% and specificity of 33.3%, with a PPV of 80.5% and NPV of 80.0%. Conclusion Our study validated the utility of the PLASMIC score, and demonstrated PLASMIC-LDH as a reasonable alternative in the absence of traditional lysis markers, to help identify high-risk patients for treatment via plasma exchange.