Combined Collection and Analysis of Inorganic and Organic Gunshot Residues.

Gunshot residue (GSR) analysis and their interpretation provide crucial information on a criminal investigation involving the use of firearms. To date, several approaches have been proposed for the implementation of a combined sampling and analysis of inorganic (IGSR) and organic GSR (OGSR). However, it is not clear at this stage if concurrent analyses of both types of residue might be detrimental to the analysis of IGSR currently applied in forensic laboratories. Thus, this work aims to compare and evaluate three different protocols for the combined collection and analysis of IGSR and OGSR. These methods, respectively, involve the use of a modified stub (with two halves, one for the detection of IGSR and the other for the analysis of OGSR); the sequential recovery of GSR with two stubs mounted with different adhesives (double-sided carbon tape and Tesa® TACK) and the sequential analysis of IGSR and OGSR from a single carbon stub following carbon deposition. The detection of IGSR was carried out using SEM-EDX, while OGSR analysis was performed using ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS). Obtained results for experiments performed using Geco Sinoxid <sup>®</sup> ammunition indicated that sequential analysis was the most suitable protocol for the combined collection and analysis of both IGSR and OGSR. A higher number of inorganic (characteristic and consistent) particles and higher concentrations of ethylcentralite, N-nitrosodiphenylamine, diphenylamine, and nitroglycerin were recovered with this method

Secondary transfer of organic gunshot residues: Empirical data to assist the evaluation of three scenarios.

The present study aimed at providing data to assess the secondary transfer of organic gunshot residues (OGSR). Three scenarios were evaluated in controlled conditions, namely displacing a firearm from point A to point B, a simple handshake and an arrest involving handcuffing on the ground. Specimens were collected from the firearm, the hands of the shooter and the non-shooter undergoing the secondary transfer in order to compare the amounts detected. Secondary transfer was observed for the three scenarios, but to a different extent. It was found that displacing a firearm resulted in secondary transfer in <50% of the experiments. The firearm also had an influence, as contrary to the pistol, no secondary OGSR were detected using the revolver. Shaking the hand of the shooter also transferred OGSR to the non-shooter's hand. In that case, the amount of OGSR was generally higher on the shooter than on the non-shooter. Finally, the largest secondary transfer was observed after the arrest with handcuffing with positive results in all cases using the pistol. In that scenario, the amounts on the shooter and the non-shooter were in the same range. This study highlights that the secondary transfer must be taken into account in the interpretation of OGSR. Indeed, an individual's hands might be contaminated by handling a firearm or having physical contact with a shooter

Validation of the Mass-Extraction-Window for Quantitative Methods Using Liquid Chromatography High Resolution Mass Spectrometry.

A paradigm shift is underway in the field of quantitative liquid chromatography-mass spectrometry (LC-MS) analysis thanks to the arrival of recent high-resolution mass spectrometers (HRMS). The capability of HRMS to perform sensitive and reliable quantifications of a large variety of analytes in HR-full scan mode is showing that it is now realistic to perform quantitative and qualitative analysis with the same instrument. Moreover, HR-full scan acquisition offers a global view of sample extracts and allows retrospective investigations as virtually all ionized compounds are detected with a high sensitivity. In time, the versatility of HRMS together with the increasing need for relative quantification of hundreds of endogenous metabolites should promote a shift from triple-quadrupole MS to HRMS. However, a current "pitfall" in quantitative LC-HRMS analysis is the lack of HRMS-specific guidance for validated quantitative analyses. Indeed, false positive and false negative HRMS detections are rare, albeit possible, if inadequate parameters are used. Here, we investigated two key parameters for the validation of LC-HRMS quantitative analyses: the mass accuracy (MA) and the mass-extraction-window (MEW) that is used to construct the extracted-ion-chromatograms. We propose MA-parameters, graphs, and equations to calculate rational MEW width for the validation of quantitative LC-HRMS methods. MA measurements were performed on four different LC-HRMS platforms. Experimentally determined MEW values ranged between 5.6 and 16.5 ppm and depended on the HRMS platform, its working environment, the calibration procedure, and the analyte considered. The proposed procedure provides a fit-for-purpose MEW determination and prevents false detections

Toxic doses of caffeine are needed to increase skeletal muscle contractility.

Discrepant results have been reported regarding an intramuscular mechanism underlying the ergogenic effect of caffeine on neuromuscular function in humans. Here, we reevaluated the effect of caffeine on muscular force production in humans and combined this with measurements of the caffeine dose-response relationship on force and cytosolic free [Ca <sup>2+</sup> ] ([Ca <sup>2+</sup> ] <sub>i</sub> ) in isolated mouse muscle fibers. Twenty-one healthy and physically active men (29 ± 9 yr, 178 ± 6 cm, 73 ± 10 kg, mean ± SD) took part in the present study. Nine participants were involved in two experimental sessions during which supramaximal single and paired electrical stimulations (at 10 and 100 Hz) were applied to the femoral nerve to record evoked forces. Evoked forces were recorded before and 1 h after ingestion of 1) 6 mg caffeine/kg body mass or 2) placebo. Caffeine plasma concentration was measured in 12 participants. In addition, submaximal tetanic force and [Ca <sup>2+</sup> ] <sub>i</sub> were measured in single mouse flexor digitorum brevis (FDB) muscle fibers exposed to 100 nM up to 5 mM caffeine. Six milligrams of caffeine per kilogram body mass (plasma concentration ~40 µM) did not increase electrically evoked forces in humans. In superfused FDB single fibers, millimolar caffeine concentrations (i.e., 15- to 35-fold above usual concentrations observed in humans) were required to increase tetanic force and [Ca <sup>2+</sup> ] <sub>i</sub> . Our results suggest that toxic doses of caffeine are required to increase muscle contractility, questioning the purported intramuscular ergogenic effect of caffeine in humans

The R&D Program for Targetry at a Neutrino Factory

The need for intense muon beams for muon colliders [1] and for neutrino factories based on muon storage rings [2, 3, 4] leads to a concept of 1-4 MW proton beams incident a moving target that is inside a 20-T solenoid magnet, with a mercury jet as a preferred example. Novel technical issues for such a system include disruption of the mercury jet by the proton beam and distortion of the jet on entering the solenoid, as well as more conventional issues of materials lifetime and handling of activated materials in an intense radiation environment. As part of the R&D program [5] of the Neutrino Factory and Muon Collider Collaboration, R&D effort related to targetry is being performed within the context of BNL E951 [6], first results of which are discussed here and in other contributions to this conference

An activating mutation in the kinase homology domain of the natriuretic peptide receptor-2 causes extremely tall stature without skeletal deformities

Background: C-type natriuretic peptide (CNP)/natriuretic peptide receptor 2 (NPR2) signaling is essential for long bone growth. Enhanced CNP production caused by chromosomal translocations results in tall stature, a Marfanoid phenotype, and skeletal abnormalities.Asimilar phenotype was described in a family with an activating NPR2 mutation within the guanylyl cyclase domain. Case: Here we describe an extremely tall male without skeletal deformities, with a novel NPR2 mutation (p.Arg655Cys) located in the kinase homology domain. Objectives: The objective of the study was to investigate the functional and structural effects of the NPR2 mutation. Methods: Guanylyl cyclase activities of wild-type vs mutant NPR2 were analyzed in transfected human embryonic kidney 293 cells and in skin fibroblasts. The former were also used to study possible interactions between both isoforms. Homology modeling was performed to understand the molecular impact of the mutation. Results: CNP-stimulated cGMP production by the mutant NPR2 was markedly increased in patient skin fibroblasts and transfected human embryonic kidney 293 cells. The stimulatory effects of ATP on CNP-dependent guanylyl cyclase activity were augmented, suggesting that this novel mutation enhances both the responsiveness of NPR2 to CNP and its allosteric modulation/stabilization by ATP. Coimmunoprecipitation showed that wild-type and mutant NPR2 can form stable heterodimers, suggesting a dominant-positive effect. In accordance with augmented endogenous receptor activity, plasma N-terminal pro-CNP (a marker of CNP production in tissues) was reduced in the proband. Conclusions:Wereport the first activating mutation within the kinase homology domain of NPR2, resulting in extremely tall stature. Our observations emphasize the important role of this domain in the regulation of guanylyl cyclase activity and bone growth in response to CNP

Detailed stratified GWAS analysis for severe COVID-19 in four European populations

Given the highly variable clinical phenotype of Coronavirus disease 2019 (COVID-19), a deeper analysis of the host genetic contribution to severe COVID-19 is important to improve our understanding of underlying disease mechanisms. Here, we describe an extended GWAS meta-analysis of a well-characterized cohort of 3255 COVID-19 patients with respiratory failure and 12 488 population controls from Italy, Spain, Norway and Germany/Austria, including stratified analyses based on age, sex and disease severity, as well as targeted analyses of chromosome Y haplotypes, the human leukocyte antigen (HLA) region and the SARS-CoV-2 peptidome. By inversion imputation, we traced a reported association at 17q21.31 to a ~ 0.9-Mb inversion polymorphism that creates two highly differentiated haplotypes and characterized the potential effects of the inversion in detail. Our data, together with the 5th release of summary statistics from the COVID-19 Host Genetics Initiative including non-Caucasian individuals, also identified a new locus at 19q13.33, including NAPSA, a gene which is expressed primarily in alveolar cells responsible for gas exchange in the lung