Yoshiyasu Higashikawa

Studies on 1-(2-phenethyl)-4-(N-propionylanilino)piperidine (fentanyl) and its related compounds. VI. Structure-analgesic activity relationship for fentanyl, methyl-substituted fentanyls and other analogues

Eleven chemically modified 1-(2-phenethyl)-4-(N-propionylanilino)-piperidine (fentanyl) analogues were synthesized and their analgesic activities were evaluated by the acetic acid writhing method in mice. Their effective dose (ED50) and lethal dose (LD50) values were compared with those of morphine and fentanyl. The synthesized fentanyl analogues were categorized into three groups: a mono-methylated group, a group in which hydrogen in the para-position of the aromatic ring bound to the propionylanilino group was substituted with F, Cl, CH3, or OCH3, and a group in which the propionyl moiety was changed to an acetyl one. 3-Methylfentanyl showed the strongest analgesic activity among these compounds, and the most frequently abused fentanyl derivative, α-methylfentanyl, also showed quite strong activity. The analgesic activities of p-fluorofentanyl and acetylfentanyl were also relatively strong and not negligible. The activities of other analogues were significantly lower than that of fentanyl. The ranges between LD50 and ED50 of these fentanyl analogues were narrower than that of fentanyl. A number of fatal cases in humans caused by the abuse of fentanyl analogues are considered to be due not only to overdosing but also to the narrow ranges between the ED50 and LD50 values.

Guilty by his fibers: suspect confession versus textile fibers reconstructed simulation

In one particular criminal case involving murder and theft, the arrested suspect admitted to the theft, but denied responsibility for the murder of the inhabitant of the crime scene. In his confession, the suspect stated that he found the victims body when he broke into the crime scene to commit theft. For this report, the actual crime scene was reconstructed in accordance with the confession obtained during the interrogation of the suspect, and suspect behavior was simulated in accord to the suspect confession. The number of characteristic fibers retrieved from the simulated crime scene was compared with those of retrieved from the actual crime scene. By comparing the distribution and number of characteristic fibers collected in the simulation experiments and the actual investigation, the reliability of the suspects confession was evaluated. The characteristic dark yellowish-green woolen fibers of the garment that the suspect wore when he entered the crime scene were selected as the target fiber in the reconstruction. The experimental simulations were conducted four times. The distributed target fibers were retrieved using the same type of adhesive tape and the same protocol by the same police officers who conducted the retrieval of the fibers at the actual crime scene. The fibers were identified both through morphological observation and by color comparisons of their ultaviolet-visible transmittance spectra measured with a microspectrophotometer. The fibers collected with the adhesive tape were counted for each area to compare with those collected in the actual crime scene investigation. The numbers of fibers found at each area of the body, mattress and blankets were compared between the simulated experiments and the actual investigation, and a significant difference was found. In particular, the numbers of fibers found near the victims head were significantly different. As a result, the suspects confession was not considered to be reliable, as a stronger contact with the victim was demonstrated by our simulations. During the control trial, traditional forensic traces like DNA or fingerprints were mute regarding the suspects says. At the opposite, the fiber intelligence was highly significant to explain the suspects behavior at the crime scene. The fiber results and simulations were presented at the court and the man was subsequently found guilty not only of theft and trespassing but also murder.

Feasibility Study of Visualizing Diversity of Japanese Hiragana Handwritings by Multidimensional Scaling of Earth Mover's Distance toward Assisting Forensic Experts in Writer Verification

In this paper, we demonstrated a mapping procedure to visualize the diversity of overall handwriting shapes of five Japanese Hiragana characters for the purpose of assisting forensic examiners in the process of writer verification. Multidimensional scaling was applied to Earth Movers Distance (EMD) data calculated between 60 different writers in order to visualize each writers feature in population. EMD flow was calculated between k-means cluster centroids, which are representative points of kernel density distribution of handwritten stroke of each writer within six trials. Experimental results showed that the relative relation of overall handwritten shapes of each writer was successfully visualized as the locus in multidimensional space. The state of distribution such as the density in multidimensional space is considered to provide effective information to forensic examiners in evaluating the rarity of handwritten features observed in questioned document.

Wide-field time-resolved luminescence imaging and spectroscopy to decipher obliterated documents in forensic science

Abstract. We applied a wide-field time-resolved luminescence (TRL) method with a pulsed laser and a gated intensified charge coupled device (ICCD) for deciphering obliterated documents for use in forensic science. The TRL method can nondestructively measure the dynamics of luminescence, including fluorescence and phosphorescence lifetimes, which prove to be useful parameters for image detection. First, we measured the TRL spectra of four brands of black porous-tip pen inks on paper to estimate their luminescence lifetimes. Next, we acquired the TRL images of 12 obliterated documents at various delay times and gate times of the ICCD. The obliterated contents were revealed in the TRL images because of the difference in the luminescence lifetimes of the inks. This method requires no pretreatment, is nondestructive, and has the advantage of wide-field imaging, which makes it is easy to control the gate timing. This demonstration proves that TRL imaging and spectroscopy are powerful tools for forensic document examination.

Improvement of inkjet printer spur gear teeth number estimation by fixing the order in maximum entropy spectral analysis

In this paper, we estimated the number of inkjet printer spur gear teeth from shorter pitch data strings than previous study by fixing the order in maximum entropy method (MEM). The purpose of this study is to improve the efficiency of inkjet printer model identification based on spur mark comparison method (SCM) in the field of forensic document analysis. Experiments were performed using two spur gears in different color inkjet printer models. The eight kinds of pitch data length whose length ranges from three to 10 rotations of spur gear was provided for analysis. The experimental results showed that proper teeth number was estimated from shorter pitch data string compared with the strategies based on minimum AIC estimate in our previous study. The estimation was successful from the short data length nearly equal to the condition of nyquist frequency. The proposed method was considered to improve the accuracy of printer model identification based on SCM.

Estimation of Inkjet Printer Spur Gear Teeth Number from Pitch Data String of Limited Length

In this paper, we investigate the feasibility of estimating the number of inkjet printer spur gear teeth from pitch data strings of limited length by maximum entropy spectral analysis. The purpose of this study is to improve the efficiency of inkjet printer model identification based on spur mark comparison in the field of forensic document analysis. Experiments were performed using two spur gears in different color inkjet printer models, and eight different lengths of pitch data strings--ranging from three to 10 times the number of spur gear teeth. The result for a data string longer than five times the number of teeth showed a proper estimation within a deviation of one tooth. However, the estimation failed for shorter data strings because the order in maximum entropy analysis was determined inappropriately. The presented results provide information on the number of spur gear teeth from shorter data strings than in a previous study.

Differentiation of black writing ink on paper using luminescence lifetime by time-resolved luminescence spectroscopy

The time-resolved luminescence spectra and the lifetimes of eighteen black writing inks were measured to differentiate pen ink on altered documents. The spectra and lifetimes depended on the samples. About half of the samples only exhibited short-lived luminescence components on the nanosecond time scale. On the other hand, the other samples exhibited short- and long-lived components on the microsecond time scale. The samples could be classified into fifteen groups based on the luminescence spectra and dynamics. Therefore, luminescence lifetime can be used for the differentiation of writing inks, and luminescence lifetime imaging can be applied for the examination of altered documents.