Surface-enhanced Raman spectroscopy for the forensic analysis of vaginal fluid

Vaginal fluid is most often found at crime scenes where a sexual assault has taken place or on clothing or other items collected from sexual assault victims or perpetrators. Because the victim is generally known in these cases, detection of vaginal fluid is not a matter of individual identification, as it might be for semen identification. Instead, linkages can be made between victim and suspect if the sexual assault was carried out digitally or with a foreign object (e.g., bottle, pool cue, cigarette, handle of a hammer or other tool, etc.). If such an object is only analyzed for DNA and the victim is identified, the suspect may claim that the victim’s DNA is present because she handled and/or is the owner of the object and not because it was used to sexually assault her; identification of vaginal fluid residue would alleviate such uncertainty. Most of the research conducted thus far regarding methods for the identification of vaginal fluid involves mRNA biomarkers and identification of various bacterial strains.1-3 However, these approaches require extensive sample preparation and laboratory analysis and have not fully explored the genomic differences among all body fluid RNAs. No existing methods of vaginal fluid identification incorporate both high specificity and rapid analysis.4 Therefore, a new rapid detection method is required. Surface-enhanced Raman spectroscopy (SERS) is an emerging technique with high sensitivity for the forensic analysis of various body fluids. This technique has the potential to improve current vaginal fluid identification techniques due to its ease-of-use, rapid analysis time, portability, and non-destructive nature. For this experiment, all vaginal fluid samples were collected from anonymous donors by saturation of a cotton swab via vaginal insertion. Samples were analyzed on gold nanoparticle chips.4 This nanostructured metal substrate is essential for the large signal-enhancement effect of SERS and also quenches any background fluorescence that sometimes interferes with normal Raman spectroscopy measurements.5 Vaginal fluid SERS signal variation of a single sample over a six-month period was evaluated under both ambient and frozen storage conditions. Vaginal fluid samples were also taken from 10 individuals over the course of a single menstrual cycle. Four samples collected at one-week intervals were obtained from each individual and analyzed using SERS. The SERS vaginal fluid signals showed very little variation as a function of time and storage conditions, indicating that the spectral pattern of vaginal fluid is not likely to change over time. The samples analyzed over the span of one menstrual cycle showed slight intra-donor differences, however, the overall spectral patterns remained consistent and reproducible. When cycle spectra were compared between individuals, very little donor-to-donor variation was observed indicating the potential for a universal vaginal fluid signature spectrum. A cross-validated, partial least squares – discriminant analysis (PLS-DA) model was built to classify all body fluids, where vaginal fluid was identified with 95.0% sensitivity and 96.6% specificity, which indicates that the spectral pattern of vaginal fluid was successfully distinguished from semen and blood. Thus, SERS has a high potential for application in the field of forensic science for vaginal fluid analysis

Protective adaptations

Consists of five pieces of sculpture which explore organic forms and the contrasting characteristics between protective exteriors versus vulnerable interiors

Detection prospects for multi-GeV neutrinos from collisionally heated GRBs

Neutrinos with energies ranging from GeV to sub-TeV are expected to be produced in γ-ray Bursts (GRBs) as a result of the dissipation of the jet kinetic energy through nuclear collisions occurring around or below the photosphere, where the jet is still optically thick to high-energy radiation. So far, neutrino emission from the inelastic collisional model in GRBs has been poorly investigated from the experimental point of view. In the present work, we discuss prospects for identifying neutrinos produced in such collisionally heated GRBs with the large-volume neutrino telescopes KM3NeT and IceCube, including their low-energy extensions, KM3NeT/ORCA and DeepCore, respectively. We evaluated the detection sensitivity for neutrinos from both individual and stacked GRBs, exploring bulk Lorentz factor values ranging from 100 to 600. As a result of our analysis, individual searches appear feasible only for extreme sources, characterized by γ-ray fluence values at the level of Fγ ≥ 10−2 erg cm−2. In turn, it is possible to detect a significant flux of neutrinos from a stacking sample of ∼ 900 long GRBs (which could be detected by current γ-ray satellites in about five years) already with DeepCore and KM3NeT/ORCA. The detection sensitivity increases with the inclusion of data from the high-energy telescopes, IceCube and KM3NeT/ARCA, respectively

On the hadronic origin of the TeV radiation from GRB 190114C

The recently discovered TeV emission from Gamma-Ray Bursts (GRBs) hints towards a possible hadronic origin of this radiation component. We developed a Monte Carlo (MC) simulation reproducing the kinematics of photo-hadronic interactions at internal shocks, including the pair production process that the secondary gamma rays undergo in the GRB jet. We find that sub-TeV observations of GRB 190114C can be reproduced by a baryonic energy content comparable to that in sub-GeV photons and a bulk Lorentz factor $\Gamma=100$, with a ms variability timescale. Neutrino flux predictions by the model are found to be consistent with experimental upper limits set by ANTARES and IceCube

On the hadronic origin of the TeV radiation from GRB 190114C

The recently discovered TeV emission from Gamma-Ray Bursts (GRBs) has renewed the long-standing discussion about the hadronic versus leptonic origin of the observed GRB radiation. In this work, we investigate the possibility that the very high energy gamma rays observed by MAGIC from GRB 190114C (with energy from similar to 0.1 to similar to 0.8 TeV) are originated in a hadronic model. We developed a Monte Carlo (MC) simulation of the source internal state dynamics and of the photo-hadronic interactions at internal shock. We in-cluded in the simulation also the pair production process that the secondary gamma rays undergo in the GRB jet. We find upper limits on the internal shock model parameters by comparing our simulations to the sub-TeV observations of GRB 190114C. Neutrino flux predictions by the model are found to be consistent with experimental upper limits set by ANTARES and IceCube

Radiologic-Pathologic Correlation of Unusual Lingual Masses: Part II: Benign and Malignant Tumors

Because the tongue is superficially located and the initial manifestation of most diseases occurring there is mucosal change, lingual lesionscan be easily accessed and diagnosed without imaging analysis. Some lingual neoplasms, however, may manifest as a submucosal bulge and be located in a deep portion of the tongue, such as its base; their true characteristics and extent may be recognized only on cross-sectional images such as those obtained by CT or MRI

Neutrino predictions from choked GRBs and comparison with the observed cosmic neutrino flux

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Neutrino predictions from choked Gamma-Ray Bursts and comparison with the observed cosmic diffuse neutrino flux

The strong constraints from the Fermi-LAT data on the isotropic gamma-ray background suggest that the neutrinos observed by IceCube might possibly come from sources that are hidden to gamma-ray observations. A possibility emerged in recent years is that neutrinos may come from jets of collapsing massive stars which fail to break out of the stellar envelope, and for this reason they are known as choked jets, or choked Gamma-Ray Bursts (GRBs). We here show our predictions of neutrino flux and spectrum expected from these sources, focusing on Type II SNe, through detailed calculations of pγ interactions and accounting for all the neutrino production channels and scattering angles. We provide predictions of expected event rates for ANTARES, IceCube, and the next generation neutrino telescope KM3NeT.We also compute the contribution of the choked GRB population to the diffuse astrophysical neutrino flux, thus providing constraints on the local rate of this source population as to reproduce the observed neutrino flux