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The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2’s Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu’s surface age.

The near-Earth asteroid 162173 Ryugu, the target of the Hayabusa2 sample-return mission, is thought to be a primitive carbonaceous object. We report reflectance spectra of Ryugu’s surface acquired with the Near-Infrared Spectrometer (NIRS3) on Hayabusa2, to provide direct measurements of the surface composition and geological context for the returned samples. A weak, narrow absorption feature centered at 2.72 micrometers was detected across the entire observed surface, indicating that hydroxyl (OH)–bearing minerals are ubiquitous there. The intensity of the OH feature and low albedo are similar to thermally and/or shock-metamorphosed carbonaceous chondrite meteorites. There are few variations in the OH-band position, which is consistent with Ryugu being a compositionally homogeneous rubble-pile object generated from impact fragments of an undifferentiated aqueously altered parent body.

Purpose Since the 1980s, the detection sensitivity of mass spectrometers has increased by improving the analysis of drugs in hair. Accordingly, the number of hair strands required for the analysis has decreased. The length of the hair segment used in the analysis has also shortened. In 2016, micro-segmental hair analysis (MSA), which cuts a single hair strand at a 0.4-mm interval corresponding to a hair growth length of approximately one day, was developed. The advantage of MSA is that the analytical results provide powerful evidence of drug use in the investigation of drug-related crimes and detailed information about the mechanism of drug uptake into hair. This review article focuses on the MSA technique and its applications in forensic toxicology. Methods Multiple databases, such as SciFinder, PubMed, and Google, were utilized to collect relevant reports referring to MSA and drug analysis in hair. The experiences of our research group on the MSA were also included in this review. Results The analytical results provide a detailed drug distribution profile in a hair strand, which is useful for examining the mechanism of drug uptake into hair in detail. Additionally, the analytical method has been used for various scenarios in forensic toxicology, such as the estimation of days of drug consumption and death. Conclusions The detailed procedures are summarized so that beginners can use the analytical method in their laboratories. Moreover, some application examples are presented, and the limitations of the current analytical method and future perspectives are described.

Using angle-resolved photoemission spectroscopy (ARPES) and density functional theory (DFT), an experimental and theoretical study of changes in the electronic structure (dispersion dependencies) and corresponding modification of the energy band gap at the Dirac point (DP) for topological insulator (TI) have been carried out with gradual replacement of magnetic Mn atoms by non-magnetic Ge atoms when concentration of the latter was varied from 10% to 75%. It was shown that when Ge concentration increases, the bulk band gap decreases and reaches zero plateau in the concentration range of 45–60% while trivial surface states (TrSS) are present and exhibit an energy splitting of 100 and 70 meV in different types of measurements. It was also shown that TSS disappear from the measured band dispersions at a Ge concentration of about 40%. DFT calculations of band structure were carried out to identify the nature of observed band dispersion features and to analyze the possibility of magnetic Weyl semimetal state formation in this system. These calculations were performed for both antiferromagnetic (AFM) and ferromagnetic (FM) ordering types while the spin-orbit coupling (SOC) strength was varied or a strain (compression or tension) along the c-axis was applied. Calculations show that two different series of topological phase transitions (TPTs) may be implemented in this system, depending on the magnetic ordering. In the case of AFM ordering, the transition between TI and the trivial insulator phase passes through the Dirac semimetal state, whereas for FM phase such route admits three intermediate states instead of one (TI—Dirac semimetal—Weyl semimetal—Dirac semimetal—trivial insulator). Weyl points that form in the FM system along the direction annihilate when either the SOC strength decreases or a sufficient tensile strain is applied, which is accompanied by the corresponding TPTs. Model calculations of the influence of local magnetic ordering in AFM were carried out by alternating Mn layers with Ge-doped layers and showed that the magnetic Weyl semimetal state in this system is reachable at a Ge concentration of approximately 40% without application of any external magnetic fields.

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. After 5 min incubation, the kit was scanned by a flatbed scanner and the membrane image was processed with ImageJ. Results When the 20-fold diluted serum was applied, serum samples with initial caffeine concentration ≤ 25 and ≥ 50 µg/mL were caffeine-negative and -positive, respectively. When the 100-fold diluted serum was applied, none of the caffeine-spiked serum samples gave positive results. Therefore, we proposed the following test procedure: (i) 20-fold diluted serum was initially tested and (ii) 100-fold diluted serum was additionally tested when the initial result was caffeine positive. Using this procedure, caffeine concentration is expected to be classified into three levels: ≤ 25, > 25– ≤ 100, and > 100 µg/mL, which almost correspond to no or mild, severe, and potentially fatal intoxication, respectively. The test procedure was validated using postmortem heart blood from two cases of fatal caffeine intoxication (caffeine concentration: 276 and 175 µg/mL) and two cases of other intoxication. Conclusions Our developed method using point-of-care urinary caffeine test kits enabled simple estimation of serum caffeine concentration.

BACKGROUND AND AIMS: Global warming is gaining significance as a threat to natural and managed ecosystems since temperature is one of the major environmental factors affecting plant productivity. Hence, the effects of moderate temperature increase on the growth and development of the tomato plant (Lycopersicon esculentum) were investigated. METHODS: Plants were grown at 32/26 °C as a moderately elevated temperature stress (METS) treatment or at 28/22 °C (day/night temperatures) as a control with natural light conditions. Vegetative growth and reproductive development as well as sugar content and metabolism, proline content and translocation in the androecium were investigated. KEY RESULTS: METS did not cause a significant change in biomass, the number of flowers, or the number of pollen grains produced, but there was a significant decrease in the number of fruit set, pollen viability and the number of pollen grains released. Glucose and fructose contents in the androecium (i.e. all stamens from one flower) were generally higher in the control than METS, but sucrose was higher in METS. Coincidently, the mRNA transcript abundance of acid invertase in the androecium was decreased by METS. Proline contents in the androecium were almost the same in the control and METS, while the mRNA transcript level of proline transporter 1, which expresses specifically at the surface of microspores, was significantly decreased by METS. CONCLUSIONS: The research indicated that failure of tomato fruit set under a moderately increased temperature above optimal is due to the disruption of sugar metabolism and proline translocation during the narrow window of male reproductive development.

In postmortem examinations, the drug analysis of hair is effective for revealing drug-use history. Additionally, a method to estimate the day of death using hair was previously developed by analyzing a single hair strand segmented at 0.4-mm intervals (micro-segmental hair analysis). However, for drowned bodies, drugs in the hair may be washed out due to soaking in water for extended periods. To evaluate the possibility of measuring drug distribution in the hair of drowned bodies, drug stability in hair samples soaked in various aqueous solutions was examined. First, reference hair strands of drug users containing specific drugs consistently along the hair shaft were prepared. The participants ingested 4 hay-fever medicines (fexofenadine, epinastine, cetirizine, and loratadine) every day for approximately 4 months before hair collection. Each reference strand was divided into regions, and each region was soaked in different solutions containing various solutes for extended periods up to approximately 2 months. In solutions without divalent ions (Ca2+ and Mg2+), the drug content in the hair decreased up to approximately 5 % with increasing salt concentration and soaking time. However, the decreased drug content was negligible in solutions containing divalent ions, implying that the divalent ions prevented drugs contained in hair from washing out. As natural river and sea waters contain divalent ions, the drugs in hair were hardly washed out even when the hair was soaked for 2 months. Thus, it was concluded that drug-distribution measurements using micro-segmental analysis can also be applied to the hairs of drowned bodies.HighlightsDrug stabilities in hair soaked in various aqueous solutions were examined.Drug concentrations in hair decreased depending on solutes and soaking time.Divalent ions, such as Ca2+ and Mg2+, prevent drugs from being washed out.River and sea waters hardly affected the drug contents in hair.Micro-segmental analysis is effective even for hair of drowned bodies.

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. Reference nails containing the four medicines were collected from patients with hay fever who ingested the medicines daily for four months. The nails were exposed to various natural environments for up to four months. Results The effects of temperature, humidity, and light on drug contents in the nails were comparatively small. Soil significantly decomposed the nail surfaces and decreased the drug content of the nails (up to 17 %). Water also decreased the drug content (up to 12 %), although no apparent changes in nail surfaces were observed. Conclusions In comparison with hair data obtained under the same environmental conditions, light affected drugs in the hair rather than in nails, whereas water and soil greatly affected drugs in the nails rather than in hair. Although the disposition of drugs incorporated in the tissues differed between nails and hair, the analytes were detected in nails and hair strands left in severe natural environments. MSA could be useful for estimating drug-use histories and personal profiles using the nails and hair of a corpse.

[Display omitted] •Chiral SFC method for ephedrine and its stereoisomers was developed.•The method was suitable for crystalline methamphetamine including ephedrines.•Fast analysis (11min) with baseline separation was achieved.•Unsupervised multivariate analysis objectively classified seized methamphetamine. In forensic science, drug profiling is clarifying the identity of seized drugs of abuse based on their physicochemical properties and it is applied to various drugs, including crystalline methamphetamine. Impurity analysis is particularly important in drug profiling because the impurities can be a measure for speculating how the methamphetamine was synthesized in the clandestine laboratories. However, developments in scientific techniques have allowed the synthesis of high-purity, homogeneous crystalline methamphetamine, and thus new techniques to characterize methamphetamine are needed. In this study, we developed a method for chiral separation of ephedrine and its stereoisomers by supercritical fluid chromatography. Ephedrine is a common starting compound for methamphetamine synthesis. It possesses two chiral center carbon atoms and has four stereoisomers, (1R,2S)–(−)–ephedrine, (1S,2R)–(+)–ephedrine, (1S,2S)–(+)–pseudoephedrine, and (1R,2R)–(−)–pseudoephedrine. Because the stereostructure of ephedrines contained in methamphetamine seizure reflects the starting materials and the synthetic pathways, the stereoisomer ratio will provide additional information for drug profiling. The developed method achieved rapid separation of four isomers in about 11min with low limits of detection (1pg on column). Due to a switching valve connecting a chromatograph to a mass spectrometer, dense methamphetamine sample solutions containing small amount of ephedrines could be analyzed directly with a simple pre-treatment. Using multivariate analysis, 44 real samples were objectively grouped based on stereoisomer ratio. Our method is expected to improve the profiling of crystalline methamphetamine.

Purpose Since the mid-2010s, lysergic acid diethylamide (LSD) analogs made for substance abuse have periodically emerged. In this case, three pieces of blotter paper labeled “1D-LSD” and presumably impregnated with this LSD analog, were seized. Several websites indicate that 1D-LSD is 1-(1,2-dimethylcyclobutane-1-carbonyl)-LSD. Because this analog is much more difficult to synthesize than previously reported LSD analogs, we doubted that the blotter paper contained 1D-LSD. Herein, we determined the structure of the absorbed compound. Methods One of the seized specimens was extracted and analyzed using gas chromatography/mass spectrometry (GC/MS), liquid chromatography/mass spectrometry (LC/MS), high-resolution mass spectrometry (HRMS), and nuclear magnetic resonance (NMR) spectroscopy to estimate the extract components. The estimated compound was then synthesized, yielding an authentic standard. The contents of the seized specimens were identified using authentic standard analysis with GC/MS, LC/MS, and NMR spectroscopy. Results Instrumental analyses confirmed the active compound to be 1-(thiophene-2-carbonyl)-LSD, which was inconsistent with the labeling on drug-infused blotter paper. Conclusion As in this case, similar blotter paper analyses should consider the possibility of a mismatch between the label and ingredient. To the authors’ knowledge, this is the first case report in which 1-(thiophene-2-carbonyl)-LSD was seized and the first seizure of an LSD analog in which an aromatic carboxylic acid had been condensed to LSD. This type of lysergamide may become prevalent in the near future, and we should remain alert for newly appearing lysergamides.