2-Propanol Suspension Method to Increase Acetylcholinesterase and Flow Stability on μPADs.

Ensuring detection performance and shelf life is crucial for analytical devices. Advances in materials and reaction mechanisms have improved detection performance, yet extending the operational lifetime of microfluidic paper-based analytical devices (μPADs)─especially those reliant on sensitive enzymes─remains a challenge. Here, we present an alternative to air-drying and lyophilization: loading enzymes suspended in 2-propanol (iPrOH).

Forensic-geology-based magnetic analysis of beach sediments from the Shimokita Peninsula, Japan.

The occurrences of various illegal activities on beaches require effective geological and environmental investigation methods. Among these methods, the room-temperature magnetic analysis of soils and sediments represents a nondestructive investigation method for various amounts, types, and grain sizes of magnetic minerals. Here, to verify the usefulness of magnetic analysis in forensic geology research, beach sediment samples from nine sites in the Shimokita Peninsula, Japan, were measured using magnetic analysis to determine the correlations between their concentration-dependent magnetic parameters and actual regional characteristics.

Metagenomic sequencing of CRISPRs as a new marker to aid in personal identification with low-biomass samples.

The high specificity of the human skin microbiome is expected to provide a new marker for personal identification. Metagenomic sequencing of clustered regularly interspaced short palindromic repeats (CRISPRs), which we call metaCRISPR typing, was shown to achieve personal identification accurately. However, the intra-individual variability observed in previous studies, which may be due to poor DNA yields from skin samples, has resulted in non-reproducible results.

Simultaneous analysis of depurinated nucleic acid stem-loop and free adenine for ricin toxicity assay by hydrophilic interaction liquid chromatography-high-resolution mass spectrometry (HILIC-HRMS).

A simple, accurate method for measuring ricin activity was developed by detecting depurinated nucleic acid stem-loops and adenine using a commercially available hydrophilic interaction liquid chromatography (HILIC) column and a quadrupole-Orbitrap tandem mass spectrometer. Ricin in beverages was isolated using magnetic beads conjugated with ricin B-chain antibodies, and then incubated with a 14 mer RNA or a 12 mer RNA/DNA chimera, in which adenosine at the depurination site of RNA was replaced by deoxyadenosine. The adenine and depurinated nucleic acids were separated by HILIC and both analytes were detected by high-resolution mass spectrometry.

Development of a simple estimation method of serum caffeine concentration using a point-of-care test kit for urinary caffeine.

Purpose: Serum caffeine concentration is an indicator of caffeine intoxication; however, it is difficult to measure it in most emergency departments. We developed a simple estimation method using a point-of-care test kit for urinary caffeine.

Methods: Caffeine-spiked human serum (100, 50, 25, and 10 µg/mL) was diluted 10-, 20-, 50-, and 100-fold with phosphate-buffered saline and applied to the kit.

Compact and transportable system for detecting lead-shielded highly enriched uranium using Cf rotation method with a water Cherenkov neutron detector.

The global challenge of on-site detection of highly enriched uranium (HEU), a substance with considerable potential for unauthorized use in nuclear security, is a critical concern. Traditional passive nondestructive assay (NDA) techniques, such as gamma-ray spectroscopy with high-purity germanium detectors, face significant challenges in detecting HEU when it is shielded by heavy metals. Addressing this critical security need, we introduce an on-site detection method for lead-shielded HEU employing a transportable NDA system that utilizes the Cf rotation method with a water Cherenkov neutron detector.

Effects of natural environments on drug contents in nails: comparison of drug residual rates between nails and hair to determine the drug-use history of corpses in unnatural death cases using micro-segmental analysis.

Purpose: We previously developed evaluation methods using micro-segmental analysis (MSA) to examine the effects of external environments on drug content in hair and nails. In this study, the effects of the natural environmental factors (water, temperature, humidity, light, and soil) on drug contents in nails were examined and compared with our previous experimental data on hair.

Methods: Four hay-fever medicines were used as model drugs (fexofenadine, epinastine, cetirizine, and desloratadine) to evaluate drug stability in the nails.

Synthesis and analytical characterization of 1-(2-thienoyl)-6-allyl-nor-d-lysergic acid diethylamide (1T-AL-LAD).

Lysergic acid diethylamide (LSD) analogs have emerged as new psychoactive substances (NPS) since the mid-2010s, and new compounds continue to emerge for recreational use. Since the end of 2023, "1D-AL-LAD" appeared on X (formerly Twitter) and other websites. As for the compound "1D-LSD" (which also has "1D" in the name), several studies show that the ingredient of seized blotter paper printed "1D-LSD" was actually 1-(2-thienoyl)-LSD (1T-LSD).

Area measure of skin conductance in the Concealed Information Test.

Skin conductance (SC) is one of the indices commonly used in the autonomic Concealed Information Test (CIT), but SC amplitude is sometimes difficult to quantify. This study investigated the applicability of SC area to the CIT as an unambiguous measure of SC. Secondary analyses of an existing dataset indicated that SC area could be used to classify examinees according to their knowledge status, although the equivalence of its performance with the SC amplitude was inconclusive.

Quantitative evaluation of endometrium-expressed mRNAs for the purpose of discriminating between menstruation and traumatic vaginal injury in sexual assault cases.

In sexual assault cases, it is crucial to discriminate between peripheral blood and menstrual blood to provide evidence for vaginal intercourse with traumatic injury. In this study, the menstrual blood mRNA markers progestagen-associated endometrial protein (PAEP), matrix metallopeptidase 7 (MMP7), and left-right determination factor 2 (LEFTY2) were evaluated by quantitative RT-PCR (RT-qPCR) for the discrimination of menstrual blood from peripheral blood and vaginal fluid. As a result, all markers with cutoff delta cycle quantification (ΔCq) values were specifically determined in menstrual blood among forensically relevant body fluids.

Visualization of latent fingerprints using fluorescence lifetime imaging on paper emitting strong fluorescence.

Latent fingerprints were successfully visualized using fluorescence lifetime imaging (FLIM) on paper which emits strong fluorescence with a lifetime close to that of fingerprints and thus from which it is difficult for time-resolved spectroscopy to visualize fingerprints. Latent fingerprint samples on paper were excited using a 450 nm or 532 nm nanosecond pulsed-laser, and time-resolved fluorescence images were obtained at a delay time of 6-16 ns in intervals of 1 ns, to the excitation pulse. The excitation beam was expanded using a lens, and the fluorescence from the fingerprints was captured using an intensified CCD camera.

Y chromosome haplogroup N in a Japanese population is classified into three subclades, and two DYS385 loci, a duplicated Y-STR, are duplicated again in subclade N-M1819.

DYS385 is one of the major Y chromosome short tandem repeats (Y-STRs) in forensic genetics and exists as 2 copies in the human Y chromosome palindrome P4 region. In this study, we found that some samples were estimated to have ≥ 4 copies of DYS385 in Y chromosome haplogroup N in a Japanese population. Y chromosome haplogroup N is distributed widely in eastern/central Asia, Siberia, and eastern/northern Europe, and is also observed in Japan; however, little is known about haplogroup N subclades in the Japanese population.

Development and comparison of forensic interval age prediction models by statistical and machine learning methods based on the methylation rates of ELOVL2 in blood DNA.

Age estimation can be useful information for narrowing down candidates of unidentified donors in criminal investigations. Various age estimation models based on DNA methylation biomarkers have been developed for forensic usage in the past decade. However, many of these models using ordinary least squares regression cannot generate an appropriate estimation due to the deterioration in prediction accuracy caused by an increased prediction error in older age groups.

COL1A2 Barcoding: Bone Species Identification via Shotgun Proteomics.

Species identification of fragmentary bones remains a challenging task in archeology and forensics. A species identification method for such fragmentary bones that has recently attracted interest is the use of bone collagen proteins. Here, we describe a method similar to DNA barcoding that reads collagen protein sequences in bone and automatically determines the species by performing sequence database searches.

Effects of temperature, humidity, light, and soil on drug stability in hair: a preliminary study for estimating personal profiles using micro-segmental analysis of corpse hair.

Purpose: Micro-segmental hair analysis (MSA), which enables detailed measurement of the distribution of drugs in a single hair strand, is useful for examining the day of death and drug use history of a person. However, corpses are often found in severe environments, such as soil and freezers, which affect the drug contents in hair. Therefore, we examined the effects of temperature, humidity, light, and soil on drug stability in hair as a preliminary study to estimate personal profiles using MSA of corpse hair.