Multi-omics characterization of NIST seafood reference materials and alternative matrix preparations.

The National Institute of Standards and Technology (NIST) has prepared four seafood reference materials (RMs) for use in food safety and nutrition studies: wild-caught and aquacultured salmon (RM 8256 and RM 8257) and wild-caught and aquacultured shrimp (RM 8258 and RM 8259). These materials were characterized using genetic, metabolomic (1H-NMR, nuclear magnetic resonance and LC-HRMS/MS, liquid chromatography high-resolution tandem mass spectrometry), lipidomic, and proteomic methods to explore their use as matrix-matched, multi-omic differential materials for method development towards identifying product source and/or as quality control in untargeted omics studies. The results from experimental replicates were reproducible for each reference material and analytical method, with the most abundant features reported. Additionally, differences between the materials could be detected, where wild-caught and aquacultured seafood could be distinguished using untargeted metabolite, lipid, and protein analyses. Further processing of the fresh-frozen RMs by freeze-drying revealed the freeze-dried seafoods could still be reliably discerned. These results demonstrate the usefulness of these reference materials as tools for omics instrument validation and measurement harmonization in seafood-related studies. Furthermore, their use as differential quality control (QC) materials, regardless of preparation method, may also provide a tool for laboratories to demonstrate proficiency at discriminating between products based on source/species.

Current Practices in LC-MS Untargeted Metabolomics: A Scoping Review on the Use of Pooled Quality Control Samples.

Untargeted metabolomics is an analytical approach with numerous applications serving as an effective metabolic phenotyping platform to characterize small molecules within a biological system. Data quality can be challenging to evaluate and demonstrate in metabolomics experiments. This has driven the use of pooled quality control (QC) samples for monitoring and, if necessary, correcting for analytical variance introduced during sample preparation and data acquisition stages. Described herein is a scoping literature review detailing the use of pooled QC samples in published untargeted liquid chromatography-mass spectrometry (LC-MS) based metabolomics studies. A literature query was performed, the list of papers was filtered, and suitable articles were randomly sampled. In total, 109 papers were each reviewed by at least five reviewers, answering predefined questions surrounding the use of pooled quality control samples. The results of the review indicate that use of pooled QC samples has been relatively widely adopted by the metabolomics community and that it is used at a similar frequency across biological taxa and sample types in both small- and large-scale studies. However, while many studies generated and analyzed pooled QC samples, relatively few reported the use of pooled QC samples to improve data quality. This demonstrates a clear opportunity for the field to more frequently utilize pooled QC samples for quality reporting, feature filtering, analytical drift correction, and metabolite annotation. Additionally, our survey approach enabled us to assess the ambiguity in the reporting of the methods used to describe the generation and use of pooled QC samples. This analysis indicates that many details of the QC framework are missing or unclear, limiting the reader's ability to determine which QC steps have been taken. Collectively, these results capture the current state of pooled QC sample usage and highlight existing strengths and deficiencies as they are applied in untargeted LC-MS metabolomics.

Proteomics as a Metrological Tool to Evaluate Genome Annotation Accuracy Following De Novo Genome Assembly: A Case Study Using the Atlantic Bottlenose Dolphin (Tursiops truncatus).

The last decade has witnessed dramatic improvements in whole-genome sequencing capabilities coupled to drastically decreased costs, leading to an inundation of high-quality de novo genomes. For this reason, the continued development of genome quality metrics is imperative. Using the 2016 Atlantic bottlenose dolphin NCBI RefSeq annotation and mass spectrometry-based proteomic analysis of six tissues, we confirmed 10,402 proteins from 4711 protein groups, constituting nearly one-third of the possible predicted proteins. Since the identification of larger proteins with more identified peptides implies reduced database fragmentation and improved gene annotation accuracy, we propose the metric NP10, which attempts to capture this quality improvement. The NP10 metric is calculated by first stratifying proteomic results by identifying the top decile (or 10th 10-quantile) of identified proteins based on the number of peptides per protein and then returns the median molecular weight of the resulting proteins. When using the 2016 versus 2012 Tursiops truncatus genome annotation to search this proteomic data set, there was a 21% improvement in NP10. This metric was further demonstrated by using a publicly available proteomic data set to compare human genome annotations from 2004, 2013 and 2016, which showed a 33% improvement in NP10. These results demonstrate that proteomics may be a useful metrological tool to benchmark genome accuracy, though there is a need for reference proteomic datasets across species to facilitate the evaluation of new de novo and existing genome.

Feasibility of a pilot dyadic randomized controlled trial testing the effects of three behavioral interventions on older adults' cognitive, physical and everyday function.

Introduction: Maintaining functional abilities is critical for optimizing older adults' well-being and independence. This randomized controlled trial (RCT) pilot examined the feasibility of testing the effects of three commercially available interventions on function-related outcomes in older adults. Methods: Pairs of community-dwelling older adults (N=55, Mage=71.4) were randomized to a 10-week intervention (cognitive-COG, physical-EX, combined exergame-EXCOG, or control-CON). Cognitive, physical, and everyday function were assessed at baseline, immediately post-intervention, and 6-months post-intervention. Feasibility was evaluated using recruitment, enrollment, training adherence, and retention metrics. Variability and patterns of change in functional outcomes were examined descriptively. Results: A total of 208 individuals were screened, with 26% subsequently randomized. Across training arms, 95% of training sessions were completed and 89% of participants were retained at immediate post-test. Variability in functional outcomes and patterns of change differed across study arms. Discussion: Results support a fully powered RCT, with several modifications to the pilot study design, to investigate short- and long-term training impacts.

Considering community care in public health responses: A national study regarding palliative care during a prolonged coronavirus disease 2019 lockdown.

OBJECTIVE: To describe changes in palliative care characteristics, utilisation and outcomes in Victoria during a period of enhanced public health management and a prolonged lockdown due to coronavirus disease 2019. METHODS: A national retrospective cohort study with palliative care service setting comparisons in Victoria and other mainland states was conducted. RESULTS: Analysis of 48 non-Victorian services (n=53,428 patients) and 20 Victorian services (n=31,125 patients) showed that for community services, patient volume, average length of stay, functional dependency and the proportion of admissions in a deteriorating phase increased during the lockdown in Victoria, yet little changed in comparator states. Regarding inpatient services, the management of family/carer problems remained constant in comparator states, yet substantial fluctuations in outcomes in Victoria were observed. CONCLUSIONS: As health systems adapt to changing circumstances during the pandemic, the ability to upscale community services is critical. Addressing the implications of shifting inpatient care to the community needs attention. IMPLICATIONS FOR PUBLIC HEALTH: Our study highlights the need to ensure community care providers are adequately considered within public health management responses. 'Joined up' policy and implementation across care settings are essential, especially as major barriers to infection control and increased utilisation may be evident in the community during the coronavirus disease 2019 pandemic.

Midterm Outcomes of the INBONETM II Total Ankle Arthroplasty.

As the number of total ankle arthroplasties (TAA) performed continues to increase, understanding midterm outcomes can guide both implant selection and preoperative patient counseling. The purpose of this study was to investigate midterm results including the survival rate and reasons for revision for the INBONETM II TAA. Patients undergoing a primary TAA with the study implant and minimum of 4.6 years postoperative follow-up were reviewed from a prospectively collected database. The primary outcome was implant survival. Secondary outcomes included coronal plane radiographic alignment, evaluation for cysts and osteolysis, and failure mode when applicable. Patients were eligible for inclusion in this study if they had a minimum of 4.6-year follow-up TAA with the study implant. Eighty-five TAAs in 83 patients were eligible for inclusion; 75 TAA in 73 patients were included in the study. The mean duration of follow up was 6.2 ± 0.9 years (range 4.7-8.1 years). Thirty-six percent of the TAAs had a preoperative coronal plane deformity of at least 10°, and 12% of the TAAs had at least 20°. There were 6 (8%) implant failures that occurred at a mean 2.0 ± 1.4 years postoperatively. Eighty-one percent of the TAAs had no reoperation events in the follow-up period. Midterm outcomes at a minimum of 4.6 years postoperatively in patients undergoing a TAA using this implant demonstrates acceptable implant survival, an approximately 20% reoperation rate, and maintenance of coronal plane alignment.

The influence of proteoforms: assessing the accuracy of total vitamin D-binding protein quantification by proteolysis and LC-MS/MS.

OBJECTIVES: Vitamin D-binding protein (VDBP), a serum transport protein for 25-hydroxyvitamin D [25(OH)D], has three common proteoforms which have co-localized amino acid variations and glycosylation. A monoclonal immunoassay was found to differentially detect VDBP proteoforms and methods using liquid chromatography-tandem mass spectrometry (LC-MS/MS) might be able to overcome this limitation. Previously developed multiple reaction monitoring LC-MS/MS methods for total VDBP quantification represent an opportunity to probe the potential effects of proteoforms on proteolysis, instrument response and quantification accuracy. METHODS: VDBP was purified from homozygous human donors and quantified using proteolysis or acid hydrolysis and LC-MS/MS. An interlaboratory comparison was performed using pooled human plasma [Standard Reference Material® 1950 (SRM 1950) Metabolites in Frozen Human Plasma] and analyses with different LC-MS/MS methods in two laboratories. RESULTS: Several shared peptides from purified proteoforms were found to give reproducible concentrations [≤2.7% coefficient of variation (CV)] and linear instrument responses (R2≥0.9971) when added to human serum. Total VDBP concentrations from proteolysis or amino acid analysis (AAA) of purified proteoforms had ≤1.92% CV. SRM 1950, containing multiple proteoforms, quantified in two laboratories resulted in total VDBP concentrations with 7.05% CV. CONCLUSIONS: VDBP proteoforms were not found to cause bias during quantification by LC-MS/MS, thus demonstrating that a family of proteins can be accurately quantified using shared peptides. A reference value was assigned for total VDBP in SRM 1950, which may be used to standardize methods and improve the accuracy of VDBP quantification in research and clinical samples.

African American Alzheimer's Caregiver Training and Support Project 2 (ACTS2) pilot study: Outcomes analysis.

PURPOSE/OBJECTIVE: The purpose of this study was to conduct an initial evaluation of the quantitative and qualitative outcomes of the African American Alzheimer's Caregiver Training and Support Project 2 (ACTS2). Quantitative objectives focused on assessing changes in caregiver depression and health status, as well as the severity of caregiving and self-care problems from pre- to postintervention. Secondary quantitative analyses examined posttreatment changes in social support and caregiver burden. Qualitative objectives included examining caregivers' perceptions of the effectiveness of in-session training activities, quality of relationships among group participants and their facilitator, and appraisals of spiritual elements of the program. RESEARCH METHOD/DESIGN: Nine African American family caregivers of older adults with dementia completed the ACTS2 lay pastoral care facilitator-led, telephone cognitive-behavioral intervention. The 12-week training program included seven skills-building groups and five individual problem-solving sessions. RESULTS: Significant improvements were found on the majority of dependent measures, including caregiver depression, health status, problem severity, and social support. Qualitative analysis highlighted the value caregivers placed on relationships with coparticipants and group facilitators, the role of spirituality in the program, and the importance of goal setting for improving caregiver distress and self-care. CONCLUSIONS/IMPLICATIONS: Convergence was found between quantitative and qualitative findings, particularly improvements in caregiver distress, health status, and social support. Overall, the findings of the pilot study were promising. Replication using a randomized controlled design with a larger sample size is needed to test the reliability of the findings. The benefits of tailoring intervention to caregivers' sociocultural preferences and spiritual values are also addressed. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Complications, Reoperations, and Patient-Reported Outcomes Following a 2-Stage Revision Total Ankle Arthroplasty for Chronic Periprosthetic Joint Infections.

BACKGROUND: As total ankle arthroplasty (TAA) becomes more common, chronic periprosthetic joint infections (PJIs) will be encountered more frequently. No studies have reported on patient-reported outcomes following a 2-stage revision procedure for a chronic PJI after a TAA. The primary purpose of this study was to investigate postoperative clinical outcomes at a minimum of 2 years following a 2-stage revision TAA for chronic PJI. METHODS: Patients who underwent a 2-stage revision TAA for a chronic PJI (>4 weeks after a primary TAA) between January 2010 and December 2019 were eligible to be included in this study. Chronic PJI was defined as a sinus tract that directly communicated with the prosthesis or the same organism identified in ≥2 synovial fluid samples. Twelve patients were eligible to be included in this case series. One patient died prior to 2-year follow-up, which left 11 patients available for analysis. All 11 patients underwent reimplantation. The data were found not to be normally distributed; therefore, medians and interquartile ranges (IQRs) were reported. RESULTS: At a median of 3.0 years (IQR 2.0-4.0 years) following the second stage of their revision arthroplasty, the median Foot and Ankle Ability Measure (FAAM) Activities of Daily Living and Sports scores were 60.7 (IQR 52.4, 79.8) and 31.3 (IQR 9.4, 40.6), respectively. At final follow-up, 10 patients (90.9%) were ambulating with a TAA in place. Seven patients (63.6%) required a reoperation including 1 patient who underwent a below-knee amputation. CONCLUSION: Our study suggests that a 2-stage revision TAA may be an option for patients with a chronic PJI. However, patients who undergo a 2-stage revision TAA for a chronic PJI have lower than previously published 2-year FAAM scores and a high rate of reoperation. LEVEL OF EVIDENCE: Level IV, case series.

Transforming Social Determinants to Educational Outcomes: Geospatial Considerations.

In recovering from one of the worst educational crises in recorded history due to the pandemic, in a mission to rebuild and become more resilient, there has been a heightened urgency to provide resources to communities most in need. However, precisely identifying those needs have become all the more important due to the increase in popularity of e-learning as a suitable option and the improvement of technologies. Most notably, socially disadvantaged and historically marginalized communities were disproportionately and severely impacted by several aspects of the pandemic, in terms of health, economics, access to education, and sustainable well-being. This differential effect was modeled spatially with the combination of aerial photogrammetry, traditional geospatial mapping, and other robust AI-driven techniques to synthesize and analyze the various types of data. In this original research study, we apply various spatial health variables, relate them to educational variables in an initial empirical process of understanding how to address equity-related considerations from the context of the learner's experience, providing the empirical evidence for the development of locally tailored learner support and assistance, meeting students where they are by specifically identifying and targetting geographically underserved areas. We found that there were clear statistically significant relationships between educational attainment and several physical (p < 0.001), mental (p = 0.003), access to healthy food/food security (p < 0.001), and uptake of preventative health measures (p < 0.001), which also varied geographically. Geographic variations in learning experiences demonstrates the unquestionable need to understand a variety of physical, mental, and dietary factors surrounding the student's success. Understanding a combination of these factors in a geospatial context will allow educational institutions to best serve the needs of learners.

Peronosporaceae species causing downy mildew diseases of Poaceae, including nomenclature revisions and diagnostic resources.

Downy mildew pathogens of graminicolous hosts (Poaceae) are members of eight morphologically and phylogenetically distinct genera in the Peronosporaceae (Oomycota, Peronosporales). Graminicolous downy mildews (GDMs) cause severe losses in crops such as maize, millets, sorghum, and sugarcane in many parts of the world, especially in tropical climates. In countries where the most destructive GDMs are not endemic, these organisms are often designated as high-risk foreign pathogens and subject to oversight and quarantine by regulatory officials. Thus, there is a need to reliably and accurately identify the causal organisms. This paper provides an overview of the Peronosporaceae species causing graminicolous downy mildew diseases, with a description of their impact on agriculture and the environment, along with brief summaries of the nomenclatural and taxonomic issues surrounding these taxa. Key diagnostic characters are summarized, including DNA sequence data for types and/or voucher specimens, morphological features, and new illustrations. New sequence data for cox2 and 28S rDNA markers are provided from the type specimens of three species, Peronosclerospora philippinensis, Sclerospora iseilematis, and Sclerospora northii. Thirty-nine species of graminicolous downy mildews are accepted, and seven previously invalidly published taxa are validated. Fifty-five specimens are formally designated as types, including lectotypification of 10 species, neotypification of three species, and holotype designation for Sclerophthora cryophila. Citation: Crouch JA, Davis WJ, Shishkoff N, Castroagudín VL, Martin F, Michelmore R, Thines M (2022). Peronosporaceae species causing downy mildew diseases of Poaceae, including nomenclature revisions and diagnostic resources. Fungal Systematics and Evolution 9: 43-86. doi: 10.3114/fuse.2022.09.05.

Interrater agreement of the HEART score history component: A chart review study.

Study objectives: This study investigated the interrater reliability of the history component of the HEART (history, electrocardiogram, age, risk, troponin) score between physicians in emergency medicine (EM) and internal medicine (IM) at 1 tertiary-care center. Methods: We conducted a retrospective, secondary analysis of 60 encounters selected randomly from a database of 417 patients with chest pain presenting from January to June 2016 to an urban tertiary-care center. A total of 4 raters (1 EM attending, 1 EM resident, 1 IM attending, and 1 IM resident) scored the previously abstracted history data from these encounters.The primary outcome was the interrater agreement of HEART score history components, as measured by kappa coefficient, between EM and IM attending physicians. Secondary outcomes included the agreement between attending and resident physicians, overall agreement, pairwise percent agreement, and differences in scores assigned. Results: The kappa value for the EM attending physician and IM attending physician was 0.33 with 55% agreement. Interrater agreement of the other pairs was substantial between EM attending and resident but was otherwise fair to moderate. Percent agreement between the other pairs ranged from 48.3% to 80%. There was a significant difference in scores assigned and the subgroup in which there was disagreement between the raters demonstrated significantly higher scores by the EM attending and resident when compared to the IM attending. Conclusion: This study demonstrates fair agreement between EM and IM attending physicians in the history component of the HEART score with significantly higher scores by the EM attending physician in cases of disagreement at 1 tertiary-care center.

Reference materials for MS-based untargeted metabolomics and lipidomics: a review by the metabolomics quality assurance and quality control consortium (mQACC).

INTRODUCTION: The metabolomics quality assurance and quality control consortium (mQACC) is enabling the identification, development, prioritization, and promotion of suitable reference materials (RMs) to be used in quality assurance (QA) and quality control (QC) for untargeted metabolomics research. OBJECTIVES: This review aims to highlight current RMs, and methodologies used within untargeted metabolomics and lipidomics communities to ensure standardization of results obtained from data analysis, interpretation and cross-study, and cross-laboratory comparisons. The essence of the aims is also applicable to other 'omics areas that generate high dimensional data. RESULTS: The potential for game-changing biochemical discoveries through mass spectrometry-based (MS) untargeted metabolomics and lipidomics are predicated on the evolution of more confident qualitative (and eventually quantitative) results from research laboratories. RMs are thus critical QC tools to be able to assure standardization, comparability, repeatability and reproducibility for untargeted data analysis, interpretation, to compare data within and across studies and across multiple laboratories. Standard operating procedures (SOPs) that promote, describe and exemplify the use of RMs will also improve QC for the metabolomics and lipidomics communities. CONCLUSIONS: The application of RMs described in this review may significantly improve data quality to support metabolomics and lipidomics research. The continued development and deployment of new RMs, together with interlaboratory studies and educational outreach and training, will further promote sound QA practices in the community.

Mortality and Conversion Rates to Below-Knee or Above-Knee Amputation After Transmetatarsal Amputation.

INTRODUCTION: The purpose of this study was to identify associated risk factors for complications, need for a higher level of amputation such as below-knee amputation (BKA) or above-knee amputation (AKA), and mortality after transmetatarsal amputation (TMA). METHODS: We identified 265 patients who underwent 286 TMA procedures between June 2002 and July 2016. Medical records were reviewed for revision surgery and amputation. Mortality was verified using the National Death Index. We identified and documented potential risk factors including diabetes, hemoglobin A1c level, end-stage renal disease, cardiovascular disease, peripheral vascular disease, history of revascularization, contralateral amputation, and neuropathy. Sixty-eight percent were male, the mean age was 56.9 years (SD 12.8; range 24.1 to 92.1), and the median body mass index was 28.6 (interquartile range, 24.5 to 33.1). RESULTS: Twenty-seven percent of the patients required a subsequent BKA or AKA after the index TMA surgery. The results of a multivariable model indicated that women (odds ratio [OR], 3.63; 95% confidence interval [CI], 1.716 to 7.672), patients aged 57 to 64 years (OR, 0.17; 95% CI, 0.06 to 0.51), and patients with a history of revascularization (OR, 7.06, 95% CI, 2.86 to 17.44) had markedly higher odds than the relevant comparison groups. Forty percent of the patients died after the index TMA at a median of 27 months. After adjusting for all patient factors, history of end-stage renal disease (OR, 2.2; 95% CI, 1.206 to 4.014) and cardiovascular disease (OR, 2.879; 95% CI, 1.615 to 5.131) remained markedly associated with mortality after TMA. DISCUSSION: There are high rates of additional amputation after nontraumatic TMA and a high mortality rate. Surgeons should set realistic expectations with patients considered for TMA and identify risk factors, which may guide treatment. Treatment is multidisciplinary, requiring attention to surgical details, correction of vascular deficiency or contracture when present, and perioperative medical optimization. LEVEL OF EVIDENCE: IV.

Reaching for equitable care: High levels of disability-related knowledge and cultural competence only get us so far.

BACKGROUND: Achieving equitable medical care for people with disabilities is a complex challenge with emphasis often placed on the need for improved physician knowledge and cultural competence. Physical medicine and rehabilitation (PM&R) is a specialty dedicated to maximizing patient function, where a focus on working with and learning from patients with complex disabilities informs physician training and patient care. OBJECTIVE: The purpose of this study was to assess barriers to equitable care in PM&R clinics through a structural checklist and semi-structured interviews with clinic staff and physicians. METHODS: We used qualitative analysis with a grounded theory approach to develop a unified explanation of how existing clinic processes and provider attitudes affect equitable access to medical care. RESULTS: We found physicians comfortable with and respectful of patient differences who described leveraging unpaid time and creativity to navigate structural, resource, and awareness barriers. Staff and physicians described current barriers as negatively affecting quality of care, clinic efficiency, and, in some cases, patient and staff safety. CONCLUSION: Our results suggest that high levels of physician disability-related knowledge and cultural competence may be insufficient to the challenge of achieving equitable care.

SMARCA4 biology in alveolar rhabdomyosarcoma.

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and phenocopies a muscle precursor that fails to undergo terminal differentiation. The alveolar subtype (ARMS) has the poorest prognosis and represents the greatest unmet medical need for RMS. Emerging evidence supports the role of epigenetic dysregulation in RMS. Here we show that SMARCA4/BRG1, an ATP-dependent chromatin remodeling enzyme of the SWI/SNF complex, is prominently expressed in primary tumors from ARMS patients and cell cultures. Our validation studies for a CRISPR screen of 400 epigenetic targets identified SMARCA4 as a unique factor for long-term (but not short-term) tumor cell survival in ARMS. A SMARCA4/SMARCA2 protein degrader (ACBI-1) demonstrated similar long-term tumor cell dependence in vitro and in vivo. These results credential SMARCA4 as a tumor cell dependency factor and a therapeutic target in ARMS.

Creating a Resident Research Track in Synergy With the Rehabilitation Medicine Scientist Training Program.

ABSTRACT: Physician scientists play an important role in the translation of research findings to patient care; however, their training faces numerous challenges. Residency research track programs represent an opportunity to facilitate the training of future physician scientists in physical medicine and rehabilitation, although optimal program organization and long-term outcomes remain unknown. The Rehabilitation Medicine Scientist Training Program is a National Institutes of Health-funded program aimed at addressing the shortage of physician researchers in the field of physical medicine and rehabilitation by providing instruction, mentorship, and networking opportunities for a successful research career. While the opportunities provided through the Rehabilitation Medicine Scientist Training Program provide critical education and guidance at a national level, trainees are most successful with availability of strong local support and mentorship. The purpose of this article was to present a realistic and easily applicable structure for a physical medicine and rehabilitation residency research track that can be used in concert with the Rehabilitation Medicine Scientist Training Program.

Proteogenomic Assessment of Intraspecific Venom Variability: Molecular Adaptations in the Venom Arsenal of Conus purpurascens.

Cone snails produce venom that contains diverse groups of peptides (conopeptides/conotoxins) and display a wide mass range, high rate of posttranslational modifications, and many potential pharmacological targets. Here we employ a proteogenomic approach to maximize conopeptide identification from the injected venom of Conus purpurascens. mRNA sequences from C. purpurascens venom ducts were assembled into a search database and complemented with known sequences and de novo approaches. We used a top-down peptidomic approach and tandem mass spectrometry identification to compare injected venom samples of 27 specimens. This intraspecific analysis yielded 543 unique conopeptide identifications, which included 33 base conopeptides and their toxiforms, 21 of which are novel. The results reveal two distinct venom profiles with different synergistic interactions to effectively target neural pathways aimed to immobilize prey. These venom expression patterns will aid target prediction, a significant step toward developing conotoxins into valuable drugs or neural probes.

Investigating the feasibility of ICP-MS/MS for differentiating NIST salmon reference materials through determination of Sr and S isotope ratios.

Inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) was investigated for possible use in food fraud studies through the measurement of strontium and sulfur isotope ratios. Oxygen mass shift mode was applied to shift 87Sr/86Sr and 34S/32S isotope ratios to their respective oxides, 87Sr16O+/86Sr16O+ and 34S16O+/32S16O+, effecting a gas-phase chemical separation of the elements from Rb and Kr (for Sr) and molecular N and O species, along with P- and S-hydrides (for S). A total least squares regression approach was employed to generate the isotope ratio data from time-resolved analyses, and method uncertainties and accuracies were determined. The utility of the approach was shown by using the Sr and S isotope ratios together to differentiate between NIST RM 8256 Wild-Caught Coho Salmon and NIST RM 8257 Aquacultured Coho Salmon. These materials are currently under development at NIST as certified food fraud standards and method evaluation materials for comprehensive chemical analysis.