Cerebrospinal fluid P-tau(181P):biomarker for improved differential dementia diagnosis

The goal of this study is to investigate the value of tau phosphorylated at threonine 181 (P-tau(181p)) in the Alzheimer's disease (AD) cerebrospinal fluid (CSF) biomarker panel for differential dementia diagnosis in autopsy confirmed AD and non-AD patients. The study population consisted of 140 autopsy confirmed AD and 77 autopsy confirmed non-AD dementia patients. CSF concentrations of amyloid-beta peptide of 42 amino acids (A(beta 1-42)), total tau protein (T-tau), and P-tau(181p) were determined with single analyte ELISA-kits (INNOTEST, Fujirebio, Ghent, Belgium). Diagnostic accuracy was assessed through receiver operating characteristic (ROC) curve analyses to obtain area under the curve (AUG) values and to define optimal cutoff values to discriminate AD from pooled and individual non-AD groups. ROC curve analyses were only performed on biomarkers and ratios that differed significantly between the groups. Pairwise comparison of AUG values was performed by means of DeLong tests. The A(beta 1-42)/P-tau(181p) ratio (AUG = 0.770) performed significantly better than A(beta 1-42) (AUG = 0.677, P = 0.004), T-tau (AUG = 0.592, P <0.001), and A beta(1-42)/T-tau (AUG = 0.678, P = 0.001), while Ptau(181p) (AUG = 0.720) performed significantly better than T-tau (AUG = 0.592, P <0.001) to discriminate between AD and the pooled non-AD group. When comparing AD and the individual non-AD diagnoses, A beta(1-42)/P-tau(181P) (AUG =0.894) discriminated AD from frontotemporal dementia significantly better than A(beta 1-42) (AUG = 0.776, P = 0.020) and T-tau (AUG = 0.746, P = 0.004), while P-tauisip/T-tau (AUG = 0.958) significantly improved the differentiation between AD and Creutzfeldt-Jakob disease as compared to A beta(1-42) (AUG = 0.688, P = 0.004), T-tau (AUG = 0.874, P = 0.040), and A beta(1-42)/P-tau(181P) (AUG = 0.760, P = 0.003). In conclusion, this study demonstrates P-tau(181P) P is an essential component of the AD CSF biomarker panel, and combined assessment of A beta(1-42), Ttau, and P-tau(181p) renders, to present date, the highest diagnostic power to discriminate between AD and non-AD dementias

Exploring the experiences and coping strategies of international medical students

<p>Abstract</p> <p>Background</p> <p>Few studies have addressed the challenges that international medical students face and there is a dearth of information on the behavioural strategies these students adopt to successfully progress through their academic program in the face of substantial difficulties of language barrier, curriculum overload, financial constraints and assessment tasks that require high proficiency in communication skills.</p> <p>Methods</p> <p>This study was designed primarily with the aim of enhancing understanding of the coping strategies, skill perceptions and knowledge of assessment expectations of international students as they progress through the third and fourth years of their medical degree at the School of Medicine, University of Tasmania, Australia.</p> <p>Results</p> <p>Survey, focus group discussion and individual interviews revealed that language barriers, communication skills, cultural differences, financial burdens, heavy workloads and discriminatory bottlenecks were key factors that hindered their adaptation to the Australian culture. Quantitative analyses of their examination results showed that there were highly significant (p < 0.001) variations between student performances in multiple choice questions, short answer questions and objective structured clinical examinations (70.3%, 49.7% & 61.7% respectively), indicating existence of communication issues.</p> <p>Conclusions</p> <p>Despite the challenges, these students have adopted commendable coping strategies and progressed through the course largely due to their high sense of responsibility towards their family, their focus on the goal of graduating as medical doctors and their support networks. It was concluded that faculty needs to provide both academic and moral support to their international medical students at three major intervention points, namely point of entry, mid way through the course and at the end of the course to enhance their coping skills and academic progression. Finally, appropriate recommendations were made.</p

Attenuated total reflection infrared spectroscopy for studying adsorbates on planar model catalysts : CO adsorption on silica supported Rh nanoparticles

A sensitive method is presented for studying adsorption of gaseous species on metal surfaces in vacuum by attenuated total internal reflection Fourier transform IR spectroscopy (ATR). The method is illustrated by CO adsorption expts. on silica supported Rh nanoparticles. An exptl. setup and a procedure are described in detail to obtain a sensitivity of reflectance change of .apprx.5 * 10-5 absorbance units. Here, a silicon ATR crystal with a 50 nm layer of hydroxylated silica acts as the support for the Rh nanoparticles. These particles are easily prepd. by spincoat impregnation from a RhCl3 soln. followed by H2 redn. XPS before and after redn. shows that rhodium is reduced to Rh0 and that all chlorine is removed. At. force microscope images the distribution of the particles, which are 3-4 nm in height. When the crystal is exposed to pressures up to 1 mbar of CO, a gas which is inert to the silica support, the stretch vibration of linearly adsorbed CO on the Rh nanoparticles is detected at 2023 cm-1, while no bridged CO or geminal dicarbonyl species can be distinguished. The min. detectable coverage is estd. .apprx.0.005 CO per nm2 substrate area or .apprx.5 * 10-4 ML. [on SciFinder (R)

FeP Nanocatalyst with Preferential [010] Orientation Boosts the Hydrogen Evolution Reaction in Polymer-Electrolyte Membrane Electrolyzer

The development of nonprecious metal electrocatalysts for polymer-electrolyte membrane (PEM) water electrolysis is a milestone for the technology, which currently relies on rare and expensive platinum-group metals. Half-cell measurements have shown iron phosphide materials to be promising alternative hydrogen evolution electrocatalysts, but their realistic performance in flow-through devices remains unexplored. To fill this gap, we report herein the activity and durability of FeP nanocatalyst under application-relevant conditions. Our facile synthesis route proceeds via impregnation of an iron complex on conductive carbon support followed by phosphorization, giving rise to highly crystalline nanoparticles with predominantly exposed [010] facets, which accounts for the high electrocatalytic activity. The performance of FeP gas diffusion electrodes toward hydrogen evolution was examined under application-relevant conditions in a single cell PEM water electrolysis at 22 °C. The FeP cathode exhibited a current density of 0.2 A cm–2 at 2.06 V, corresponding to a difference of merely 0.07 W cm–2 in power input as compared to state-of-the-art Pt cathode, while outperforming other nonprecious cathodes operated at similar temperature. Quantitative product analysis of our PEM device excluded the presence of side reactions and provided strong experimental evidence that our cell operates with 84–100% Faradaic efficiencies and with 4.1 kWh Nm–3 energy consumption. The FeP cathodes exhibited stable performance of over 100 h at constant operation, while their suitability with the intermittency of renewable sources was demonstrated upon 36 h operation at variable power inputs. Overall, the performance as well as our preliminary cost analysis reveal the high potential of FeP for practical applications.</p