Direct synthesis of rigid-rod aromatic polyamides was studied without condensation reagents by using reaction-induced crystallization of oligomers during solution polymerization. Polymerizations of p-aminobenzoic acid were carried out in an aromatic solvent at a polymerization concentration of 20% at 350 °C. High molecular weight poly(p-benzamide) (PBA) was obtained in the form of plate-like crystals, and the highest molecular weight was 11.6 × 103. In this polymerization, the oligomers were formed in the solution by the condensation reaction with the elimination of water. When the molecular weight of oligomers exceeded the critical value, the oligomers were precipitated by crystallization via supersaturated state to form the plate-like crystals. The molecular weight increased by the polymerization between the oligomers on and in the crystals. Poly(p-phenylene isophthalamide) (PPIA) was also obtained in the form of plate-like crystals by the polymerization of p-phenylene diamine (PPDA) and isophthalic acid (IPA) under the same condition as that of PBA. These results exhibited the thermally direct synthesis of infusible aromatic polyamides. Sequential addition of monomers into this heterogeneous polymerization was examined to increase the molecular weight. In the step-growth polymerization, the addition of monomers into the homogeneous polymerization could not increase the molecular weight because it was determined by the extent of reaction and reshuffled by the transamidation reaction. However, the addition of PPDA and IPA during the polymerization resulted in the increase in the molecular weight of PPIA. This result gave possibly a novel procedure for the preparation of high molecular weight condensation-type polymers.
Ubiquitin is a member of the heat shock protein family and is rapidly induced by various types of stimuli, including ischemic and mechanical stress. However, its significance in determining wound vitality of neck compression skin in forensic pathology remains unclear. We immunohistochemically examined the expression of ubiquitin in the neck skin samples to understand its forensic applicability in determining wound vitality. Skin samples were obtained from 53 cases of neck compression (hanging, 42 cases; strangulation, 11 cases) during forensic autopsies. Intact skin from the same individual was used as the control. Ubiquitin expression was detected in 73.9% of keratinocytes in intact skin samples, but only in 21.2% of keratinocytes in the compression regions, with statistical differences between the control and compression groups. This depletion in the case of neck compression may be caused by the impaired conversion of conjugated to free ubiquitin and failure of de novo ubiquitin synthesis. From a forensic pathological perspective, immunohistochemical examination of ubiquitin expression in the skin of the neck can be regarded as a valuable marker for diagnosing traces of antemortem compression.
We investigated the dynamics of the gene expression of M1 and M2 macrophage markers during skin wound healing in mice. Expression of M1-macrophage markers, such as Il12a, Tnf, Il6, Il1b, and Nos2 was upregulated after wounding and peaked at 1 or 3 days after injury, and that of M2-macrophage markers such as Mrc1, Cd163, Ccl17, Arg, and Tgfb1, peaked at 6 days after injury. Consistent with these findings, using triple-color immunofluorescence analysis revealed that F4/80+CD80+ M1 macrophages were more abundant than F4/80+CD206+ M2 macrophages on day 3 in mouse wound specimens, and that M2 macrophages were prominently detected in day 6 wounds. For application in forensic practice, we examined macrophage polarization using human wound specimens. The average ratios of CD68+iNOS+ M1 macrophages to CD68+CD163+ M2 macrophages (M1/M2 ratios) were greater than 2.5 for the wounds aged 2–5 days. Out of 11 wounds aged 1–5 days, five samples had the M1/M2 ratios of > 3.0. These observations propose that the M1/M2 ratios of 3.0 would indicate a wound age of 1–5 days as the forensic opinion. This study showed that M1 and M2 macrophages in human skin wound might be a promising marker for wound age determination.
This retrospective study evaluated 637 forensic autopsy cases of solitary death (kodoku-shi in Japanese) and clarified the present situation of solitary death from the viewpoints of forensic medicine. Of 637 cases who had solitary death, 471 were male and 166 were female, indicating that solitary death predominantly occurred in men. This tendency increased from the age of 40 years in men and 60 years in women. Among the cases, 349 and 199 were natural death and external death, respectively. Ischemic heart disease- and fire-related fatalities were most common in natural death and external death cases, respectively. Suicidal death was more frequent in women than in men. We found two peaks of postmortem interval until finding (PMI-f): < 1 d (182 cases, 28.6%) and 7 days to < 1 month (164 cases, 25.7%). The PMI-f in female cases was significantly shorter than that in male cases. The PMI-f of external death cases was significantly shorter than that of natural death cases. Kushimoto and Shingu, located in the southern part (Kinan region), had a high solitary death rate in forensic autopsy cases because of their small population and high aging rate. Few cases were welfare recipients in solitary death cases in Kinan region (non-urban area), and 23 of 36 welfare recipients lived in Wakayama City, indicating that the economic state would contribute more to the occurrence of solitary death in Wakayama City (urban area). We identified several risk factors and regional characteristics for solitary death cases, and our observations could contribute to administrative welfare measures for the prevention of solitary deaths.
Estimating the age and vitality of human skin wounds is essential in forensic practice, and the use of immunohistochemical parameters in this regard remains a challenge. Heat shock proteins (HSPs) are evolutionarily conserved universal proteins that protect biological systems from various types of stress. However, its importance in forensic pathology for determining wound activation in neck compression skin remains unclear. The expression of HSP27 and HSP70 in neck skin samples was immunohistochemically examined to understand its forensic applicability in determining wound vitality. Skin samples were obtained from 45 cases of neck compression (hanging, 32 cases; strangulation, 10 cases; manual strangulation, 2 cases; other, 1 case) during forensic autopsies; intact skin from the same individual was used as a control. HSP27 expression was detected in 17.4% of keratinocytes in the intact skin samples. In the compressed region, the frequency of HSP27 expression in keratinocytes was 75.8%, which was significantly higher than that in intact skin. Similarly, HSP70 expression was 24.8% in intact skin samples and 81.9% in compressed skin samples, significantly higher in compressed skin than in intact skin samples. This increase in case compression cases may be due to the cell defence role of HSPs. From a forensic pathology perspective, the immunohistochemical examination of HSP27 and HSP70 expression in neck skin could be considered a valuable marker for diagnosing traces of antemortem compression.
Pb-I layers in two-dimensional (2D) organic-inorganic hybrid perovskite thin films (CH3(CH2)3NH3)2(CH3NH3)Pb2I7 has been tried to preferentially orient perpendicular to substrates only by thermal annealing after spin coating of reagent solution for improvements of the energy-conversion-efficiency of solar cells. It is found from x-ray diffraction measurements that the ratio of diffraction intensity from (202) plane to that from (060) becomes larger in thermally annealed (50 – 135 oC) samples. This indicates that the Pb-I layer tend to grow perpendicular to the surface of the substrate. Especially, the ratio has reached to 8.2, which is larger compared with the ratio of 2.7 for randomly oriented powder sample, for the sample prepared on SnO2 substrates. Such (202) oriented films seem to contribute to improvements of the energy-conversion-efficiency of tandem type solar cells utilizing the 2D perovskite thin films as an active layer of the top cell.
We investigated the dynamics of the gene expression of M1 and M2 macrophage markers during skin wound healing in mice. Expression of M1-macrophage markers, such as Il12a, Tnf, Il6, Il1b, and Nos2 was upregulated after wounding and peaked at 1 or 3 days after injury, and that of M2-macrophage markers such as Mrc1, Cd163, Ccl17, Arg, and Tgfb1, peaked at 6 days after injury. Consistent with these findings, using double-color immunofluorescence analysis revealed that CD80-positive M1 macrophages were more abundant than CD206-positive M2 macrophages on day 3 in mouse wound specimens, and that M2 macrophages were prominently detected in day 6 wounds. For application in forensic practice, we examined macrophage polarization using human wound specimens. The average ratios of HLA-DRα-positive M1 macrophages to CD163-positive M2 macrophages (M1/M2 ratios) were greater than 2.0 for the wounds aged 2–5 days. Furthermore, six of the eight samples individually exceeded the M1/M2 ratio of 2.0 in the range of 1.88–4.30. Therefore, an M1/M2 ratio significantly above 2.0 strongly indicates a wound age of 2–5 days. This study showed that M1 and M2 macrophages in human skin wound might be a promising marker for wound age determination.
Estimating the age and vitality of human skin wounds is essential for forensic practice, and the use of immunohistochemical parameters for the same remains a challenge. Heat shock proteins (HSPs) are evolutionarily conserved, universal systems that protect the biological system from various types of stress. However, its importance in forensic pathology in determining wound activation of neck compression skin remains unclear. To understand the forensic applicability in determining wound vitality, the expression of HSP27 and HSP70 in neck skin samples was examined immunohistochemically. Skin samples were obtained from 45 cases of neck compression (hanging, 32 cases; strangulation, 10 cases; manual strangulation, two cases; other, one case) during forensic autopsies; intact skin from the same individual was used as a control. HSP27 expression was detected in 17.4% of keratinocytes in intact skin samples. In the compressed region, the frequency of HSP27 expression in keratinocytes was 75.8%, which was significantly higher than that in intact skin. Similarly, the frequency of HSP70 expression was 24.8% in intact skin and 81.9% in compressed skin, which was significantly higher in compressed skin than in intact skin. This increase in case compression cases may be due to the cell defense role of HSPs. From a forensic pathology perspective, immunohistochemical examination of HSP27 and HSP70 expression in neck skin can be seen as a valuable marker for diagnosing traces of prenatal compression.
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