Accurate diagnostic and serology assays are required for the continued management of the COVID-19 pandemic yet spike protein mutations and intellectual property concerns with antigens and antibodies used in various test kits render comparability assessments difficult. As the use of common, well-characterized reagents can help address this lack of standardization, the National Research Council Canada has produced two protein reference materials (RMs) for use in SARS-CoV-2 serology assays: biotinylated human angiotensin-converting enzyme 2 RM, ACE2-1, and SARS-CoV-2 Omicron BA.4/5 spike protein RM, OMIC-1.
View Article and Find Full Text PDFRapid antigen tests have become a widely used COVID-19 diagnostic tool with demand accelerating in response to the highly contagious SARS-CoV-2 Omicron variant. Hundreds of such test kits are approved for use worldwide, predominantly reporting on the presence of the viral nucleocapsid (N) protein, yet the comparability among manufacturers remains unclear and the need for reference standards is recognized. To address this lack of standardization, the National Research Council Canada has developed a SARS-CoV-2 nucleocapsid protein reference material solution, NCAP-1.
View Article and Find Full Text PDFDevelopment of diagnostic testing capability has advanced with unprecedented pace in response to the COVID-19 pandemic. An undesirable effect of such speed is a lack of standardization, often leading to unreliable test results. To assist the research community surmount this challenge, the National Research Council Canada has prepared a SARS-CoV-2 spike protein reference material, SMT1-1, as a buffered solution.
View Article and Find Full Text PDFObjectives: The objectives of this work were to evaluate demographic data, healing rate, recurrence rate, amputation rate and death rate of patients with diabetic foot ulcers (DFUs) treated in a Québec outpatient diabetic foot ulcer multidisciplinary clinic. Another objective was to determine factors associated with higher ulcer recurrence.
Methods: We conducted a retrospective cohort study of adults with diabetes with a DFU referred to a Québec City diabetic foot clinic between December 1, 2013 and May 1, 2019.
Valvular heart disease is observed in approximately 2% of the general population. Although the initial observation is often localized (for example, to the aortic or mitral valve), disease manifestations are regularly observed in the other valves and patients frequently require surgery. Despite the high frequency of heart valve disease, only a handful of genes have so far been identified as the monogenic causes of disease.
View Article and Find Full Text PDFDespite the huge importance of spoken language production in everyday life, little is known about the manner and extent to which the motor aspects of speech production evolve with advancing age, as well as the nature of the underlying senescence mechanisms. In this cross-sectional group study, we examined the relationship between age and speech production performance using a nonlexical speech production task in which spoken syllable frequency and phonological complexity were systematically varied to test hypotheses about underlying mechanisms. A nonprobabilistic sample of 60 cognitively healthy adults (18-83 years) produced meaningless nonwords aloud as quickly and accurately as possible.
View Article and Find Full Text PDFThe purity value assignment of metrologically traceable peptide reference standards requires specialized primary methods. Conventionally, amino acid analysis by isotope dilution tandem mass spectrometry (LC-MS/MS) following peptide hydrolysis is employed as a reference method. By contrast, quantitative nuclear magnetic resonance (qNMR) spectroscopy allows for quantitation of intact peptides, thus eliminating potential bias due to hydrolysis.
View Article and Find Full Text PDFIdentification and quantitation of related impurities is vital in obtaining corrected purity values for peptide certified reference materials. The sensitivity and selectivity of high-resolution mass spectrometry (MS) renders it an indispensable technique in this arena. Typical quantitation efforts involve constructing external calibration curves, although analysis of dilute peptide solutions can be complicated by analyte adsorption to vial walls, instrument tubing, etc.
View Article and Find Full Text PDFIn this study, we propose a novel approach for the determination of total dissolved nitrogen (TDN) in seawater combining high-precision isotope dilution GC-MS with persulfate digestion. A 2 mL sample aliquot was digested with an alkaline solution of persulfate to convert nitrogen containing compounds to nitrate. Digested samples were spiked with NO internal standard and treated with aqueous triethyloxonium to convert the analyte into volatile EtONO.
View Article and Find Full Text PDFRemote Sens Environ
January 2018
A Neural Network (NN) algorithm was developed to estimate global surface soil moisture for April 2015 to March 2017 with a 2-3 day repeat frequency using passive microwave observations from the Soil Moisture Active Passive (SMAP) satellite, surface soil temperatures from the NASA Goddard Earth Observing System Model version 5 (GEOS-5) land modeling system, and Moderate Resolution Imaging Spectroradiometer-based vegetation water content. The NN was trained on GEOS-5 soil moisture target data, making the NN estimates consistent with the GEOS-5 climatology, such that they may ultimately be assimilated into this model without further bias correction. Evaluated against in situ soil moisture measurements, the average unbiased root mean square error (ubRMSE), correlation and anomaly correlation of the NN retrievals were 0.
View Article and Find Full Text PDFRemote Sens Environ
January 2018
Launched in January 2015, the National Aeronautics and Space Administration (NASA) Soil Moisture Active Passive (SMAP) observatory was designed to provide frequent global mapping of high-resolution soil moisture and freeze-thaw state every two to three days using a radar and a radiometer operating at L-band frequencies. Despite a hardware mishap that rendered the radar inoperable shortly after launch, the radiometer continues to operate nominally, returning more than two years of science data that have helped to improve existing hydrological applications and foster new ones. Beginning in late 2016 the SMAP project launched a suite of new data products with the objective of recovering some high-resolution observation capability loss resulting from the radar malfunction.
View Article and Find Full Text PDFCyanocobalamin (CNCbl) is an active form of vitamin B12, commonly employed for the preparation of multivitamin supplements and fortified food. In this study, we present a novel analytical method for its determination based on stable isotope dilution liquid chromatography electrospray tandem mass spectrometry (ID LC-MS/MS). Isotopically enriched CNCbl was synthesized in-house and used as internal standard.
View Article and Find Full Text PDFObjectives: Ethnic discrimination increases risk for depressive symptoms, but less is known about factors that influence the impact of this cultural challenge on psychological adjustment for immigrant-origin college students. Sociocultural identity development is especially relevant during emerging adulthood. Studies examining exacerbating or buffering impacts of ethnic identity have yielded mixed results.
View Article and Find Full Text PDFThis paper evaluates the retrieval of soil moisture in the top 5-cm layer at 3-km spatial resolution using L-band dual-copolarized Soil Moisture Active-Passive (SMAP) synthetic aperture radar (SAR) data that mapped the globe every three days from mid-April to early July, 2015. Surface soil moisture retrievals using radar observations have been challenging in the past due to complicating factors of surface roughness and vegetation scattering. Here, physically based forward models of radar scattering for individual vegetation types are inverted using a time-series approach to retrieve soil moisture while correcting for the effects of static roughness and dynamic vegetation.
View Article and Find Full Text PDFLeft-ventricular outflow tract obstructions (LVOTO) encompass a wide spectrum of phenotypically heterogeneous heart malformations which frequently cluster in families. We performed family based whole-exome and targeted re-sequencing on 182 individuals from 51 families with multiple affected members. Central to our approach is the family unit which serves as a reference to identify causal genotype-phenotype correlations.
View Article and Find Full Text PDFThe effects of aging on voice production are well documented, including changes in loudness, pitch, and voice quality. However, one important and clinically relevant question that remains concerns the possibility that the aging of voice can be prevented or at least delayed through noninvasive methods. Indeed, discovering natural means to preserve the integrity of the human voice throughout aging could have a major impact on the quality of life of elderly adults.
View Article and Find Full Text PDFBackground And Objective: Pruritus is a frequent occurrence in dermatology, and investigation is often unrevealing. The authors report the case of a 65-year-old man presenting with generalized recalcitrant pruritus as the presenting manifestation of hypereosinophilic syndrome.
Methods And Results: A 65-year-old man developed intractable pruritus.
The manner and extent to which voice amplitude and frequency control mechanisms change with age is not well understood. The related question of whether the assessment of one's own voice evolves with age, concomitant with the acoustical changes that the voice undergoes, also remains unanswered. In the present study, we characterized the aging of voice production mechanisms (amplitude, frequency), compared the aging voice in different experimental contexts (vowel utterance, connected speech) and examined the relationship between voice self-assessment and age-related voice acoustical changes.
View Article and Find Full Text PDFBackground: We report a 13-year-old female patient followed since birth for multiple rare congenital defects, including hypotrichosis, telangiectasia, and severe dilatation of the ascending aorta.
Methods: Comprehensive phenotype assessment throughout childhood included repeated echocardiographic measurements, evaluation of renal function, and immunohistochemical analysis of skin biopsy samples. Whole-exome sequencing was performed for the patient and both unaffected parents.