“…This was expected for ammunition with higher-energy (Table 1 ) shot at gelatin [ 31 ]. The muzzle gasses entering the wound cavity when contact shots are applied display severe wounding potential in real gunshot cases [ 10 ] and exhibited the same destructive potential in this study as was previously described by Euteneuer et al [ 14 ] and elsewhere, e.g., as demonstrated by Schyma et al [ 22 , 32 , 33 ]. While the polygon perimeters showed hardly any difference between the various shooting distances for revolver shots (despite containing bone splinters inside nearly every wound channel), the measured values by the pistol showed larger deviations between their replicates, with the 15- and 20-cm distances exhibiting slightly lower values than the rest.…”
Section: Discussionsupporting
confidence: 79%
“…3 ). With both firearms, the wound profiles of contact shots are clearly distinguishable from those of distant shots, due to the vast destructive potential by the muzzle gasses [ 22 ]. Fig.…”
In molecular ballistics, where traces originating from the use of firearms against biological targets are investigated, “backspatter” traces are of particular importance. This biological material comprising blood and tissue from the victim is propelled back from the bullet entry site towards the direction of the shooter and can consolidate and persist on the inner and outer surfaces of the firearm, from where it can be collected and analyzed. Thus, a connection between the weapon and the victim can be established solely by molecular biological trace analysis. For the criminalistic investigation of gun-related crimes, the determination of the distance between the weapon and the victim can be of critical importance in reconstructing the circumstances of a crime. In this study, we investigated possible correlations between the shooting distance and the amount of backspatter in/on the used firearm. To this purpose, we employed a previously established skull model and performed shootings in triplicates from various distances up to 50 cm with two types of handguns (pistol and revolver). Backspatter was collected from various sampling locations, and DNA contents were quantified. A post-shooting wound channel evaluation was conducted by optical and radiological evaluation. The obtained DNA yields varied considerably between replicates from the same and from different distances. In contrast, apart from contact shots, no meaningful differences were observable in wound channel evaluations. In summary, no meaningful correlation between backspatter distribution and DNA yields, the shooting distance and the condition of the wound channel could be established.
“…This was expected for ammunition with higher-energy (Table 1 ) shot at gelatin [ 31 ]. The muzzle gasses entering the wound cavity when contact shots are applied display severe wounding potential in real gunshot cases [ 10 ] and exhibited the same destructive potential in this study as was previously described by Euteneuer et al [ 14 ] and elsewhere, e.g., as demonstrated by Schyma et al [ 22 , 32 , 33 ]. While the polygon perimeters showed hardly any difference between the various shooting distances for revolver shots (despite containing bone splinters inside nearly every wound channel), the measured values by the pistol showed larger deviations between their replicates, with the 15- and 20-cm distances exhibiting slightly lower values than the rest.…”
Section: Discussionsupporting
confidence: 79%
“…3 ). With both firearms, the wound profiles of contact shots are clearly distinguishable from those of distant shots, due to the vast destructive potential by the muzzle gasses [ 22 ]. Fig.…”
In molecular ballistics, where traces originating from the use of firearms against biological targets are investigated, “backspatter” traces are of particular importance. This biological material comprising blood and tissue from the victim is propelled back from the bullet entry site towards the direction of the shooter and can consolidate and persist on the inner and outer surfaces of the firearm, from where it can be collected and analyzed. Thus, a connection between the weapon and the victim can be established solely by molecular biological trace analysis. For the criminalistic investigation of gun-related crimes, the determination of the distance between the weapon and the victim can be of critical importance in reconstructing the circumstances of a crime. In this study, we investigated possible correlations between the shooting distance and the amount of backspatter in/on the used firearm. To this purpose, we employed a previously established skull model and performed shootings in triplicates from various distances up to 50 cm with two types of handguns (pistol and revolver). Backspatter was collected from various sampling locations, and DNA contents were quantified. A post-shooting wound channel evaluation was conducted by optical and radiological evaluation. The obtained DNA yields varied considerably between replicates from the same and from different distances. In contrast, apart from contact shots, no meaningful differences were observable in wound channel evaluations. In summary, no meaningful correlation between backspatter distribution and DNA yields, the shooting distance and the condition of the wound channel could be established.
“…The S2 subunit of S mediates both viral-cell fusion and cell-cell fusion [ 40 , 41 , 42 ], with cell-cell fusion readily observed both in a laboratory setting and in the lungs of SARS-CoV-2 infected patients [ 40 , 41 , 42 , 43 , 44 , 45 ]. To better understand the requirements and contribution of cellular proteases to S2 mediated cell-cell fusion, we performed syncytia and reporter gene assays.…”
Section: Resultsmentioning
confidence: 99%
“…However, when S1/S2 border cleavage is blocked, viral entry can be mediated through endosomal compartments with proteolytic cleavage carried out by a member of the cathepsin family, similar to the entry pathway of SARS-CoV [ 10 , 35 , 37 , 38 , 39 ]. In addition to promoting virus-cell fusion during viral particle entry, S can also promote cell-cell fusion, a pathogenic effect observed in the lungs of COVID-19 patients where neighboring cells fuse together to form large multi-nucleated cells, termed syncytia [ 40 , 41 , 42 , 43 , 44 , 45 ]. While the role of cellular proteases and S cleavage in viral entry is being extensively investigated, insight into the cleavage requirements for cell-cell fusion in SARS-CoV-2 remains more limited.…”
The trimeric SARS-CoV-2 spike protein (S) is the sole viral protein responsible for both viral binding to a host cell and the membrane fusion event needed for cell entry. In addition to facilitating fusion needed for viral entry, S can also drive cell-cell fusion, a pathogenic effect observed in the lungs of SARS-CoV-2 infected patients. While several studies have investigated S requirements involved in viral particle entry, examination of S stability and factors involved in S cell-cell fusion remain limited. A furin cleavage site at the border between the S1 and S2 subunits (S1/S2) has been identified, along with putative cathepsin L and TMPRSS2 cleavage sites within S2. We demonstrate that S must be processed at the S1/S2 border in order to mediate cell-cell fusion, and that mutations at potential cleavage sites within the S2 subunit alter S processing at the S1/S2 border, thus preventing cell-cell fusion. We also identify residues within the internal fusion peptide and the cytoplasmic tail that modulate S-mediated cell-cell fusion. Additionally, we examined S stability and protein cleavage kinetics in a variety of mammalian cell lines, including a bat cell line related to the likely reservoir species for SARS-CoV-2, and provide evidence that proteolytic processing alters the stability of the S trimer. This work therefore offers insight into S stability, proteolytic processing, and factors that mediate S cell-cell fusion, all of which help give a more comprehensive understanding of this high profile therapeutic target.
“…Each tissue type acquires different methylation patterns during its differentiation. So, these different methylation patterns can provide the basis for an assay to identify body fluids (Kader et al, 2019).…”
Background
Epigenetic modifications are heritable and follow a non-mendelian inheritance pattern. They do not alter the DNA sequence but affect the gene expression at the transcriptional level. DNA methylation is one of these epigenetic changes and it is characteristic to each tissue and shows specificity with respect to developmental stage and age. Due to its specificity and reliability, it has emerged as a valuable tool in forensic investigation. Biological samples, such as blood, saliva, semen, or hair found at the crime scene can be used to isolate DNA and study the methylation pattern. Recent developments in molecular biology techniques allowed the study of the effects of methylation in specific tissues. DNA methylation specificity is very intense. These specific markers can be used to identify the tissue type such as blood, saliva, or semen at the crime scene and helps in the identification of the culprit. The present study aimed to validate the use of DNA methylation body fluid-specific markers in the identification of peripheral blood, menstrual blood, and semen. Additionally, it aimed to investigate the potential use of such DNA methylation markers for the identification of different body fluids mixtures simulating forensic science scenarios. Different DNA methylation markers were studied in different body fluid samples (peripheral blood, menstrual blood, and semen) individually and as mixtures. DNA extraction and bisulfite conversion were performed and followed by real-time PCR.
Results
The results of real-time PCR and the statistical analysis showed that the SPERM2 marker was better than SEU2 in the identification of semen DNA in mixed samples. However, in the identification of individual semen samples, the later marker showed better results than the first one, whereas BLM1 and MENS1 markers were successful in identifying the peripheral and menstrual blood samples, respectively.
Conclusions
This data can be readily used and applied on different forensic samples for tissue identification. Further sequencing studies are strongly recommended.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
