Comparison of massively parallel sequencing to capillary electrophoresis for short tandem repeat genotyping of trace DNA.

In forensic genetics, massively parallel sequencing (MPS) offers several advantages over the current golden standard, capillary electrophoresis (CE): additional sequence information, shorter amplicon lengths, and the simultaneous analysis of many markers. These benefits result in a reduced number of reactions necessary while improving the amount of data obtained, thereby conserving valuable sample extracts. This proves particularly advantageous for the analysis of trace DNA. This study assessed the suitability of MPS for short tandem repeat (STR) typing of low template samples compared with results obtained through CE. The MPS genotypes showed higher concordance to reference genotypes, with donor alleles being more frequently assigned to be the major contributor, meeting the requirements for database entry. However, the MPS workflow is more time-consuming and associated with higher costs.

Homicide Manner-of-Death Classification in Arrest-Related Death.

ABSTRACT: Multiple studies have documented various factors that influence or determine forensic pathologist classification of manner of death. There do not appear to be any published studies on manner of death classification specifically regarding arrest-related deaths (ARDs). The goal of this study was to consider a large body of cases of nonfirearm ARDs to analyze the homicide classification with regards to numerous decedent and practitioner (medical examiner/coroner [ME/C]) variables. We analyzed 1145 US autopsy reports from the years 2006-2020, inclusive, and considered decedent variables of age, ethnicity, height, weight, body mass index, toxicology, and mention of a conducted electrical weapon and ME/C influence variables of gender, country region, and year. We found that the homicide classification likelihood increased by a factor of 1.04-1.05 per year, 1.34-1.37 for a female medical examiner, and 1.4-1.5 going from Southern states to Western states. There is an increasing trend for ME/C to label nonfirearm ARDs as homicides in the United States. The homicide classification is more common in Western states and less common in Southern states, and it was more common with a female ME/C.

The diversity of shedder tests and a novel factor that affects DNA transfer.

Since the first shedder test was formulated almost 20 years ago, a plethora of different test strategies has emerged. The amount of data generated so far is considerable. However, because of the limited reproducibility of its results, the reliability of the shedder concept is frequently questioned. This study provides a literature overview of applied shedder tests that capture the diversity of the concept. It is pointed out to what extent different classification criteria, workflows, and trace evaluation can impair the classification outcome. The robustness of shedder status was assessed by applying a promising approach established by Fonneløp et al. (Forensic Sci Int Genet 29:48-60, 21). Data provide similar results to those in recent studies but also ambiguous shedder classifications. The applied shedder test was adapted based on our own as well as the reviewed data. With novel classification parameters, promising results were achieved. This study reveals uncertainties and inconsistencies of the shedder concept. Recommendations for harmonization and transparency are proposed. Implementation of the recommendations may result in an increased impact on casework and transfer studies, including activity-level assessments. Furthermore, this study shows that moisturizers affect participants' shedder status as well as DNA transfer. The impact appears to remain relevant even 60 min post ointment application but depends greatly on the type of moisturizer applied.

Electrical weapons and rhabdomyolysis.

It has been suggested that an application of a conducted electrical weapon (CEW) might cause muscle injury such as rhabdomyolysis and an acute inflammatory response. We explored this hypothesis by testing the effects of electrical weapons on circulating markers of inflammation and muscle damage. In a prospective study, 29 volunteers received a full-trunk 5-s TASER® X26(E) CEW exposure. Venous blood samples were taken before, 5 min after, and at 24 h following the discharge. We tested for changes in serum levels of C-reactive protein (CRP), alkaline phosphatase (ALP), myoglobin, albumin, globulin, albumin/globulin ratio, aspartate and alanine aminotransferase, creatine kinase, total protein, bilirubin, and lactic acid dehydrogenase. Uncorrected CRP and myoglobin levels were lower in the immediate post exposure period (CRP levels 1.44 ± 1.39 v 1.43 ± 1.32 mg/L; p = 0.046 and myoglobin 36.8 ± 11.9 v 36.1 ± 13.9 µg/L; p = 0.0019) but these changes were not significant after correction for multiple comparisons. There were no changes in other biomarkers. At 24 h, CRP levels had decreased by 30% to 1.01 ± 0.80 mg/L (p = 0.001 from baseline). ALP was unchanged immediately after the CEW application but was reduced by 5% from baseline (66.2 ± 16.1 to 62.7 ± 16.1 IU/L; p = 0.0003) at 24 h. No other biomarkers were different from baseline at 24 h. A full-trunk electrical weapon exposure did not lead to clinically significant changes in the acute phase protein levels or changes in measures of muscle cellular injury. We found no biomarker evidence of rhabdomyolysis.

Solvent-Dependent Growth and Stabilization Mechanisms of Surfactant-Free Colloidal Pt Nanoparticles.

Understanding the formation of nanoparticles (NPs) is key to develop materials by sustainable routes. The Co4CatTM process is a new synthesis of precious metal NPs in alkaline mono-alcohols well-suited to develop active nanocatalysts. The synthesis is 'facile', surfactant-free and performed under mild conditions like low temperature. The reducing properties of the solvent are here shown to strongly influence the formation of Pt NPs. Based on the in situ formation of CO adsorbed on the NP surface by solvent oxidation, a model is proposed that accounts for the different growth and stabilization mechanisms as well as re-dispersion properties of the surfactant-free NPs in different solvents. Using in situ and ex situ characterizations, it is established that in methanol, a slow nucleation with a limited NP growth is achieved. In ethanol, a fast nucleation followed by continuous and pronounced particle sintering occurs.

A comparative study of conducted electrical weapon incapacitation during a goal-directed task.

Conducted electrical weapons (CEW) are ubiquitous in law enforcement given their unique ability to physically incapacitate violently resisting subjects. Early use of animal models to study CEW incapacitation effectiveness (e.g. porcine model with 4-limb strain gauges) proved to be poorly predictive of human incapacitation effectiveness. In a previously published human study, we developed a methodology for the prospective assessment of the incapacitation effectiveness of CEWs in highly motivated human subjects. Here we use this methodology in Part 1 to compare the incapacitation effectiveness of the newly released Axon® (formerly TASER® International) T(ASER) 7 to the TASER X26E, the "gold standard", and the TASER X2, a current model. The T7 has a new "adaptive cross-connect" technology that may improve incapacitation effectiveness in the scenario of small spreads between probe pairs, a common cause of weapon "failure" in the field. In Part 2, we use our methodology to test the functionality of the T7 cross-connect technology by comparing different bay and probe configurations. This is the first published study in the literature comparing different CEW models using this human model. For Part 1, 29 subjects completed the study and had data available for analysis. For Part 2, 21 subjects completed the study and had data available for analysis. The subjects were motivated to complete the task of reaching a suspended martial arts dummy 3.4 m (11 ft) away while being exposed "under power" to the CEW. In Part 1, subjects were assigned to 1 of 6 groups with probe spreads of 10, 20, and 30 cm (4, 8, 12 in). Subjects were exposed to a "control" CEW (either the X2 or X26E) and the T7 on alternating sides. Exposures with the X2 and T7 included 2 bay-exposures. In Part 2, 21 subjects were assigned to 1 of 5 groups of different T7 bay and probe configurations all with a theoretical effective spread of 30 cm (12 in). Subjects were rated on their progress towards successfully reaching the dummy and on the extent of limb incapacitation using a quasi-blinded expert-observer scoring panel based on high-speed video review. In Part 1, all CEW models achieved maximal or near-maximal subject control with the 30 cm probe spread. With probe spreads of 10 and 20 cm the pooled data showed the T7 to be superior to the X2 for goal achievement (p < 0.001) and limb incapacitation (p = 0.002) mostly driven by differences seen with the 10 cm spread (2-bay exposures). The T7 was non-inferior to the X26E. In Part 2, there was no statistical significance between the limb capture scores, but there was a statistically significant difference in goal scores. The results overall validate that the T7 CEW cross-connect feature performed as expected. The T7 adaptive cross-connect feature with two simultaneous deployed probe pairs demonstrated a significant improvement in incapacitation effectiveness compared to the current X2 CEW with two simultaneously deployed probe pairs. Small probe spreads are a common reason for limited incapacitation effectiveness in the field and this study suggests the T7 may offer an improvement in this scenario. The T7, with single-bay exposures, was non-inferior to the single-bay X26E.

The physiologic effects of a new generation conducted electrical weapon on human volunteers at rest.

Axon Enterprise, Inc. (Axon) released its newest generation conducted electrical weapon (CEW), the T7, in October 2018. In order to compare the effects of this new CEW to prior generations, we used our previously described methodology to study the physiologic effects of CEWs on human volunteers at rest. This was a prospective, observational study of human subjects consisting of two parts. Part 1 was testing a single cartridge (2-probe) exposure. Subjects received a 10-s exposure from the T7 to the back with a 30 cm (12 in.) spread between the two probes. Part 2 was testing a simultaneous two-cartridge (4-probe) exposure. Subjects received a 10-s exposure from the T7 to the back with two cartridges with a 10 cm (4 in.) spread between each probe pair. The probe pairs were arranged cephalad to caudal such that the distance between the top probe of the first cartridge and the bottom probe of the second cartridge was 30 cm (12 in.). Vital signs were measured immediately before and after the exposure. Continuous spirometry was performed. ECG monitoring was performed immediately before and after the exposure. Venous pH, lactate, potassium, CK, catecholamines, and troponin were measured before and immediately after the exposure, at 1-h post-exposure, and again at 24 h. 11 subjects completed part 1 of the study. 9 subjects completed part 2 of the study. No subjects had a dysrhythmia or morphology change in the surface ECG. There were no statistical changes in vital signs pre- and post-exposure. While subjects did not have a statistical change in spirometry parameters pre-exposure to exposure except for a small drop in PETCO2, there was an increase in minute ventilation after the exposure that could have several explanations. A similar pattern was seen with prior generation weapons. No subject had elevated troponin levels. Other blood parameters including venous pH, lactate, potassium, CK, and catecholamines had changes similar to prior generation weapons. Comparison of the data for the single-cartridge exposures against the simultaneous two-cartridge exposures yielded no difference in vital signs, but the minute ventilation was higher for the two-cartridge exposures. The blood data, where there was a difference, was mixed. In our study, the physiologic effects of the Axon T7 are modest, consistent with the electrically-induced motor nerve-driven muscle contraction, and were similar to prior generation weapons.

Repair of Lafosse I subscapularis lesions brings no benefit in anterosuperior rotator cuff reconstruction.

PURPOSE: Optimal management of partial anterosuperior rotator cuff tears is unknown. Our aim was to compare clinical and subjective outcomes of supraspinatus (SSP) repair patients treated with or without repair of an associated superior subscapularis (SSC) partial tear. METHODS: SSP repair patients with an associated partial (Lafosse I) tear of the superior SSC tendon were retrospectively examined. Baseline and operative data and the outcomes of shoulder range of motion (ROM), pain level, strength, Constant-Murley Score, complications at 6 months as well as patient-reported Oxford Shoulder Score, Subjective Shoulder Value, and satisfaction at 6- and 24-month post-surgery were compared between patients with and without a repaired SSC tear. Mixed models and propensity-score matching were used to adjust baseline group differences. RESULTS: Of 75 eligible patients, 34 had an SSC repair and were younger with better baseline function. Non-repair surgeries were significantly shorter by 34 min (95% CI 23-45; p < 0.001). There were no group differences in the clinical and patient-rated outcome scores at both follow-ups (n.s.) as well as in pain, muscle strength in abduction, ROM, the 6-month complication risk (risk difference - 1.9%), and satisfaction with postoperative shoulder condition (n.s.). CONCLUSION: We could not show a functional or subjective benefit of repairing cranial partial tears of the SSC tendon over debridement only in the setting of an SSP reconstruction with 24 months of follow-up. A longer operative duration is expected if a partial SSC tear repair is performed. LEVEL OF EVIDENCE: III.

Ligand-Linked Nanoparticles-Based Hydrogen Gas Sensor with Excellent Homogeneous Temperature Field and a Comparative Stability Evaluation of Different Ligand-Linked Catalysts.

This paper presents a thermoelectric gas microsensor with improved stability where platinum nanoparticles linked by bifunctional ligands are used as a catalyst. The sensor design provides a homogeneous temperature field over the membrane, an important factor for the long-term stability of the catalyst. A comprehensive study of heat transfer from the chip is performed to evaluate the convection heat loss coefficient and to understand its effect on the homogeneity of the temperature field in a real-time situation. The effect of highly heat-conductive thermopiles is also analyzed by comparing the temperature distribution and power consumption with a thermoresistive sensor of the same dimensions and materials. Despite the thermopiles, the thermoelectric sensor gives better temperature homogeneity and consumes 23% less power than the thermoresistive sensor for 90 °C average temperature on the membrane. A comparative stability analysis among ligand-linked nanoparticles with 5 different ligands and unprotected nanoparticles was done through 3 consecutive 24 h tests under 1.5% continuous hydrogen gas flow. The sensors give very stable output, almost no degradation, through 72 h (3 × 24 h) tests for 3 different ligand-linked nanoparticles. The sensor design provides superb stability to the catalyst: Even catalysts of unprotected nanoparticles withstood more than 24 h and the sensor signal degradation is only 20%.

A comparative brief on conducted electrical weapon safety.

The variety and high number of published research articles on conducted electrical weapons (CEW) provides a detailed, yet in some parts inconclusive overview of medical aspects of CEW. Due to different research approaches and the use of dissimilar test subjects, an assessment of possible health risks of CEW is limited. The present work provides a brief on CEW safety based on currently available animal, computer and human research data. Using the medical database PubMed, articles published on this topic are critically evaluated and compared with each other. Special focuses are the differences and similarities of human and animal research as well as computer simulation programs. The authors explain why some studies are more reliable than others and give their expert opinion on the safety of CEW. The body of data that have been reviewed provides reasonable support for the safety of CEW.

Cardiac and skeletal muscle effects of electrical weapons : A review of human and animal studies.

Conducted Electrical Weapons (CEWs) are being used as the preferred non-lethal force option for police and special forces worldwide. This new technology challenges an exposed opponent similarly to the way they would be challenged by physical exercise combined with emotional stress. While adrenergic and metabolic effects have been meta-analyzed and reviewed, there has been no systematic review of the effects of CEWs on skeletal and cardiac muscle. A systematic and careful search of the MedLine database was performed to find publications describing pathophysiological cardiac and skeletal muscle effects of CEWs. For skeletal muscle effects, we analyzed all publications providing changes in creatine kinase, myoglobin and potassium. For cardiac effects, we analyzed reported troponin changes and arrhythmias related to short dart-to-heart-distances. Conducted electrical weapons satisfy all relevant electrical safety standards and there are, to date, no proven electrocution incidents caused by CEWs. A potential cardiovascular risk has been recognized by some of the experimental animal data. The effects on the heart appear to be limited to instances when there is a short dart-to-heart-distance. The effect on the skeletal muscle system appears to be negligible. A responsible use of a CEW on a healthy adult, within the guidelines proposed by the manufacturer, does not imply a significant health risk for that healthy adult.

Colloids for Catalysts: A Concept for the Preparation of Superior Catalysts of Industrial Relevance.

Compared to conventional preparation methods for supported heterogeneous catalysts, the use of colloidal nanoparticles (NPs) allows for a precise control over size, size distribution, and distribution/location of the NPs on the support. However, common colloidal syntheses have restrictions that limit their applicability for industrial catalyst preparation. We present a simple, surfactant-free, and scalable preparation method for colloidal NPs to overcome these restrictions. We demonstrate how precious-metal NPs are prepared in alkaline methanol, how the particle size can be tuned, and how supported catalysts are obtained. The potential of these colloids in the preparation of improved catalysts is demonstrated by two examples from heterogeneous catalysis and electrocatalysis.

Functionalization of platinum nanoparticles with L-proline: simultaneous enhancements of catalytic activity and selectivity.

In this work we present the successful application of functionalizing Pt nanoparticles (NPs) with hydrophilic organic ligands as a strategy for enhancing their catalytic activity and selectivity. In the first step, Pt NPs were prepared by a colloidal approach and subsequently functionalized in a separate synthesis step with L-proline (PRO). The functionalized NPs were supported onto Al2O3 and investigated as heterogeneous catalysts for the selective hydrogenation of acetophenone. Whereas significant amounts of side products are formed by supported, "unprotected" (ligand-free) NPs, the PRO-functionalized Pt NPs are highly chemoselective even at 100% conversion. Experiments under kinetically controlled conditions reveal that this high chemoselectivity is not accompanied by a loss of catalytic activity. In contrast, an enhanced rate toward the desired product was found for PRO-Pt in comparison to the "unprotected" Pt NPs. This finding demonstrates that the use of ligands in heterogeneous catalysis allows for simultaneous enhancements of activity and selectivity.

Influence of Sn content on the hydrogenation of crotonaldehyde catalysed by colloidally prepared PtSn nanoparticles.

Bimetallic PtSn nanoparticles (NPs) of well-defined size and metal composition were prepared by means of colloidal methods. The mean particle diameter was about 2 nm for all samples irrespective of the Pt/Sn-ratio, which enables a systematic study of the influence of the composition on the catalytic properties while excluding particle size effects. The hydrogenation of crotonaldehyde was investigated as a reaction for which chemoselectivity is known to be a challenging task. Already very low atomic Sn contents (≈10%) were found to lead to a significantly improved activity which may be attributed to an electronic effect of Sn on Pt. For further increasing tin contents the activity decreased gradually. This trend was accompanied by a steady increase in selectivity towards the desired product (crotylalcohol). The results show that the highest crotylalcohol time yields can be obtained by using catalysts with an atomic Sn content of approximately 23%. In contrast, maximum crotylalcohol selectivities are achieved by using catalysts with a high tin content (>50%).

[The assessment of bite injuries from a forensic point of view]. / Die Beurteilung von Hundebissverletzungen aus gerichtsärztlicher Sicht.

The identification of a bite injury and its differentiation between human and animal origin demand a high level of special knowledge from the examining physician. The evaluation of bite injuries in terms of their hazard potential, risk profile and origin is usually done by a forensic specialist based on medical record documentation after immediate medical treatment. Therefore, as a first responder, a detailed documentation of the entire injury pattern is essential. If necessary, samples for further DNA analysis should be taken.The present article is intended to give a brief introduction to various aspects of bite injuries as well as to point out possibilities and limitations of the assessment of such cases.

[Fatal skiing accidents: a forensic analysis taking the example of Salzburg]. / Tödliche Skiunfälle--eine gerichtsärztliche Übersicht am Beispiel des Landes Salzburg.

The rising popularity of Alpine skiing in recent years has led to an increase of skiing accidents, some with fatal outcome. In this paper, all fatal skiing accidents from the autopsy material of the Institute of Forensic Medicine of the Paris Lodron University Salzburg were evaluated and compared with statistical data of the Alpine Police. In the wintertime of 2005/2006 until 2013/2014, 22 deadly skiing accidents were autopsied. The age of the male and female victims ranged between 12 and 71 years. The main cause of death was craniocerebral and chest trauma. A relevant blood alcohol concentration was detected in only one case. Together with trauma-biomechanical and technical experts, forensic medicine serves as a necessary clarification interface between the investigating authorities and the judiciary. Determining the cause and manner of death as well as reconstructing the accident is the main task of the forensic pathologist. The present study shows that in the county of Salzburg, only a small percentage of fatal skiing accidents is evaluated from a forensic and trauma-biomechanical point of view. Thus the possibilities of an interdisciplinary accident analysis are not always fully utilized.

The effect of particle proximity on the oxygen reduction rate of size-selected platinum clusters.

The diminished surface-area-normalized catalytic activity of highly dispersed Pt nanoparticles compared with bulk Pt is particularly intricate, and not yet understood. Here we report on the oxygen reduction reaction (ORR) activity of well-defined, size-selected Pt nanoclusters; a unique approach that allows precise control of both the cluster size and coverage, independently. Our investigations reveal that size-selected Pt nanoclusters can reach extraordinarily high ORR activities, especially in terms of mass-normalized activity, if deposited at high coverage on a glassy carbon substrate. It is observed that the Pt cluster coverage, and hence the interparticle distance, decisively influence the observed catalytic activity and that closely packed assemblies of Pt clusters approach the surface activity of bulk Pt. Our results open up new strategies for the design of catalyst materials that circumvent the detrimental dispersion effect, and may eventually allow the full electrocatalytic potential of Pt nanoclusters to be realized.

Stabilizing catalytically active nanoparticles by ligand linking: toward three-dimensional networks with high catalytic surface area.

A general approach for the linking of Pt nanoparticles (NPs) with bifunctional amine ligands (organic molecules with two amine groups) is presented that allows for the preparation of NP catalysts without inorganic supports and high densities of the catalytically active metal. Advantage was taken of the use of "unprotected" NPs, which enables us to prepare different ligand-functionalized NPs from the same particle batch and thus to relate changes of the resulting material properties exclusively to the influence of the ligand. Three bifunctional ligands with similar functional groups (amines) but different hydrocarbon skeletons were used and compared to monofunctional ligands of similar molecular structures (alkyl and aryl amines) showing significantly different material properties. Monofunctional molecules with minor steric demand cover almost completely the NP surface and lead to two-dimensional assembling of the NPs. In contrast, the use of bifunctional amine ligands leads to the formation of porous, three-dimensional NP networks (ligand-linked NPs) with a high density of ligand free surface atoms, thus enabling for the application as catalytic materials. The stabilizing effect of bifunctional ligands serves as an alternative to the use of inorganic support materials and enables for catalytic applications of ligand-linked NP networks.

Ligand-stabilized Pt nanoparticles (NPs) as novel materials for catalytic gas sensing: influence of the ligand on important catalytic properties.

Different mono- and bifunctional amine ligands have been used to stabilize Pt NPs for catalytic H2 gas sensing. Depending on the chemical structure and properties of the ligand, the catalysts show different overall sensor performances, activation periods, and long-term stabilities. These sensor characteristics are put into relation with chemical processes like cleaning of the surface, degradation processes of the ligands and nanoparticle (NP) sintering. It has been found that during activation free adsorption sites are formed primarily due to desorption of synthetic residues. Furthermore, partial desorption of the ligands followed by their degradation may occur. For monoamines the latter process results in destabilization of the NPs followed by catalyst deactivation through particle sintering. The use of bifunctional ligands that link individual NPs shows significantly enhanced stabilities which can be related to the reduction of the ligand desorption rates and degradation. Besides the functionality of the ligands it was observed that the chemical nature of their hydrocarbon skeleton affects the catalyst stability: aromatic substructures remain intact upon H2 oxidation, while alkyl fragments undergo oxidation and decomposition. The advantages of bifunctionality and an aromatic hydrocarbon skeleton can be combined by the use of para-phenylenediamine (PDA) as a linking ligand. Networks formed by this ligand were indeed found to be stable under the applied catalytic conditions for more than 24 h.