Ring-size-selective construction of fluorine-containing carbocycles via intramolecular iodoarylation of 1,1-difluoro-1-alkenes

1,1-Difluoro-1-alkenes bearing a biaryl-2-yl group effectively underwent site-selective intramolecular iodoarylation by the appropriate cationic iodine species. Iodoarylation of 2-(2-aryl-3,3-difluoroallyl)biaryls proceeded via regioselective carbon–carbon bond formation at the carbon atoms in β-position to the fluorine substituents, thereby constructing dibenzo-fused six-membered carbocycles bearing a difluoroiodomethyl group. In contrast, 2-(3,3-difluoroallyl)biaryls underwent a similar cyclization at the α-carbon atoms to afford ring-difluorinated seven-membered carbocycles

Influence of microstructure on fatigue property of ultra high-strength steels

Ultra-high-strength steels (with tensile strength higher than 980 MPa) are widely used in automobile manufacturing owing to their lightweight that contributes to fuel efficiency. The fatigue strength of ultra-high-strength steels with a notch tends to decrease, which is known as the effect of notch sensitivity. In this study, 4-point bending fatigue tests were performed to examine the fatigue strength and notch sensitivity of four steels; namely 590 MPa class steel, 980 MPa class martensitic steel, 980 MPa class bainitic steel, and 980 MPa class precipitation hardening steel plates with three different stress concentration factors. The results indicate that the fatigue strength and notch sensitivity of 980 MPa class steel specimens were higher than those of 590 MPa class steel specimens. The notch sensitivities of tested plate specimens were lower than those reported for cylindrical specimens of bainitic ultra-high-strength steels. Fatigue crack observation revealed that the cracks initiated in 590 MPa class steel, 980 MPa class bainitic, and martensitic steel propagated southward from the lowest bottom of notch. Although similar initial crack propagation pattern was detected in precipitation hardening steel, the crack changed direction when it reached the central part of the specimen

舌の厚みとその臨床的意義

Background: The tongue occupies most of the space in the oral cavity and it plays an important role in oral functions such as mastication, swallowing and articulation. The tongue continues to move from the time of intake to swallowing, particularly during masticating. A method for evaluating tongue thickness at rest by ultrasonography has been proposed; however, the association between tongue thickness and various oral functions remains unclear. Objective: The purpose of this study was to investigate the relation between tongue thickness and oral functions, and to clarify the clinical significance of tongue thickness measurements in oral function maintenance. Materials and Methods: Elderly outpatients were serially screened for enrollment and a total of 106 subjects (men, 54; women, 52; mean age, 75.2±6.5 years) were selected. Age, body mass index, and functional teeth number including implant and pontic of fixed partial denture number were recorded as the basic attributes. Tongue thickness, tongue pressure, tongue thrust pressure and tongue motor function were measured as tongue assessments. Cheek pressure, oral moisture and occlusal force were measured as other oral functions. Results: Subjects with thick tongue tended to have higher BMI, stronger muscle strengths and lower diadochokinesis. Diadochokinesis of/ka/, cheek pressure and functional teeth number were extracted as the independent factors affecting tongue thickness. Conclusion: Tongue thickness does not necessarily reflect oral functions in healthy elderly people except for a negative association between tongue thickness and oral diadochokinesis of /ka/. Multiple assessments of tongue would be required to evaluate oral function, and the assessment of tongue thickness might have a different clinical meaning

Influence of microstructure on fatigue property of ultra high-strength steels

Ultra-high-strength steels (with tensile strength higher than 980 MPa) are widely used in automobile manufacturing owing to their lightweight that contributes to fuel efficiency. The fatigue strength of ultra-high-strength steels with a notch tends to decrease, which is known as the effect of notch sensitivity. In this study, 4-point bending fatigue tests were performed to examine the fatigue strength and notch sensitivity of four steels; namely 590 MPa class steel, 980 MPa class martensitic steel, 980 MPa class bainitic steel, and 980 MPa class precipitation hardening steel plates with three different stress concentration factors. The results indicate that the fatigue strength and notch sensitivity of 980 MPa class steel specimens were higher than those of 590 MPa class steel specimens. The notch sensitivities of tested plate specimens were lower than those reported for cylindrical specimens of bainitic ultra-high-strength steels. Fatigue crack observation revealed that the cracks initiated in 590 MPa class steel, 980 MPa class bainitic, and martensitic steel propagated vertically from the lowest bottom of notch. Although similar initial crack propagation pattern was detected in precipitation hardening steel, the crack changed direction when it reached the central part of the specimen

超音波検査を用いた嚥下音産生機序の解明

Background: Cervical auscultation is a technique frequently used for the screening of dysphagia. However, this method is difficult to evaluate objectively and it is unclear how sound is generated during the swallowing process. The aim of this study was to analyze the waveform of swallowing sound and clarify the sound production process using recordings of swallowing sounds and ultrasound images (USI), performed simultaneously. Materials and Methods: Commercial natural spring water and natural carbonated water were used in experiments 1 and 2, respectively. In experiment 1, a microphone was attached to the skin of the neck of 20 young participants and swallowing sounds were recorded and analyzed. In experiment 2, swallowing processes in three participants were recorded by a medical ultrasonography apparatus. The ultrasonic probe was placed on the skin over one of the thyroid cartilages or the thyroid gland. Results: The swallowing sound wave (SSW) was divided into three sectional periods. The mean duration of the first, second, and third SSW was 210 ± 147 ms, 458 ± 113 ms, and 91 ± 61 ms, respectively. The mean intensity ratio of the first, second, and third SSW was 7.8 ± 5.2, 29.2 ± 16.5, and 5.8 ± 5.1, respectively. When the ultrasonic probe was placed on the skin over one of the thyroid cartilages, in the phase between the production of the second SSW and the silent period, the USI revealed an accumulation of swallowed material around the valleculae and oropharynx. In the silent period of the second SSW, the swallowed material accumulated around the hypopharynx. When the ultrasonic probe was placed on the skin over the thyroid gland, in the silent period of the second SSW, the USI revealed that the swallowed material had passed through esophagus. Conclusion: Waveform and USI findings from this study suggest that swallowing sound can be divided into three sectional periods: an oral phase, a pharyngeal phase, and a repositioning phase

コウクウ ケア ト シカ イリョウ デバイス

Life expectancy in Japan is among the world's highest and aging population has been increasing. Oral care in the elderly has been focused on many medical facilities for prevention from aspiration pneumonia and hospital infections. Poor oral hygiene of the elderly can cause various problems not only in the mouth but also in general health. We have studied on denture plaque micro flora, saliva and the relationship between oral and systemic conditions for more than 15 years. The results of our studies showed the direct and indirect effects of oral care. This article describes on the inflectious problem by dental devices including denture plaque, and significance of oral care through our studies

Characterization of Swallowing Sound : Preliminary Investigation of Normal Subjects

Objective The purpose of this study was to characterize the swallowing sound and identify the process of sound generation during swallowing in young healthy adults. Methods Thirty-three healthy volunteers were enrolled and allocated into three experimental groups. In experiment 1, a microphone was attached to one of eight cervical sites in 20 subjects, participants swallowed 5 ml water, and the sound waveform was recorded. In experiment 2, 10 subjects swallowed either 0, 5, 10, or 15 ml water during audio recording. In addition, participants consumed the 5 ml bolus in two different cervical postures. In experiment 3, the sound waveform and videofluoroscopy were simultaneously recorded while the three participants consumed 5 ml iopamidol solution. The duration and peak intensity ratio of the waveform were analyzed in all experimental groups. Results The acoustic analysis of the waveforms and videofluoroscopy suggested that the swallowing sound could be divided into three periods, each associated with a stage of the swallowing movement: the oral phase comprising posterior tongue and hyoid bone movement; the pharyngeal phase comprising larynx movement, hyoid bone elevation, epiglottis closure, and passage of the bolus through the esophagus orifice; and the repositioning phase comprising the return of the hyoid bone and larynx to their resting positions, and reopening of the epiglottis. Conclusion Acoustic analysis of swallowing sounds and videofluoroscopy suggests that the swallowing sound could be divided into three periods associated with each process of the swallowing movement: the oral phase comprising the posterior movement of the tongue and hyoid bone; the pharyngeal phase comprising the laryngeal movement, hyoid bone elevation, epiglottis closure, and the bolus passage to the esophagus orifice; and the repositioning phase comprising the repositioning of the hyoid bone and larynx, and reopening of the epiglottis

Association of genetically determined chronotype with circulating testosterone: a Mendelian randomization study

Low testosterone levels in men have been linked to decreased physical and mental function, as well as a reduced quality of life. Previous prospective observational studies have suggested an association between testosterone and sleep traits, but the causality of this relationship remains unclear. We aimed to explore the potential causal link between genetically determined sleep traits and testosterone levels in men using Mendelian randomization (MR) analysis from the UK Biobank dataset. Our exposures were genetic variants associated with sleep traits (chronotype and sleep duration), whereas our outcomes were traits of sex steroid hormones (total testosterone, TT; bioavailable testosterone, BAT; and sex hormone-binding globulin, SHBG). We employed inverse variance weighted (IVW) and weighted median (WM) methods to assess the causal associations. The IVW method offers a robust estimate of causality, whereas the WM method provides reliable results even when some genetic variants are invalid instruments. Our main analysis involving sex steroid hormones and chronotype identified 155 chronotype-related variants. The primary findings from the analysis, which used chronotype as the exposure and sex steroid hormones as the outcomes, showed that a genetically predicted chronotype score was significantly associated with an increased levels of TT (association coefficient β, 0.08; 95% confidence interval [CI], 0.02–0.14; P = 0.008) and BAT (β, 0.08; 95% CI, 0.02–0.14; P = 0.007), whereas there was no significant association with SHBG (β, 0.01; 95% CI, −0.02–0.03; P = 0.64). Meanwhile, MR analysis of sex steroid hormones and sleep duration was performed, and 69 variants associated with sleep duration were extracted. There were no significant association between sleep duration and sex steroid hormones (TT, P = 0.91; BAT, P = 0.82; and SHBG, P = 0.95). Our data support a causal association between chronotype and circulating testosterone levels in men. These findings underscore a potential causal relationship between chronotype and testosterone levels in men, suggesting that lifestyle adjustments are crucial for men’s health. Recognizing factors that influence testosterone is essential. One limitation of this study is the use of one-sample MR, which can introduce potential bias due to non-independence of genetic associations for exposure and outcome. In conclusion, our findings indicate that a morning preference is correlated with circulating testosterone levels, emphasizing the potential impact of lifestyle habits on testosterone levels in men

High-pressure xenon gas time projection chamber with scalable design and its performance at around the Q value of 136^{136}Xe double-beta decay

We have been developing a high-pressure xenon gas time projection chamber (TPC) to search for neutrinoless double beta ($0\nu\beta\beta$) decay of $^{136}$Xe. The unique feature of this TPC is in the detection part of ionization electrons, called ELCC. ELCC is composed of multiple units, and one unit covers 48.5 $\mathrm{cm}^2$. A 180 L size prototype detector with 12 units, 672 channels, of ELCC was constructed and operated with 7.6 bar natural xenon gas to evaluate the performance of the detector at around the Q value of $^{136}$Xe $0\nu\beta\beta$. The obtained FWHM energy resolution is (0.73 $\pm$ 0.11) % at 1836 keV. This corresponds to (0.60 $\pm$ 0.03) % to (0.70 $\pm$ 0.21) % of energy resolution at the Q value of $^{136}Xe$ $0\nu\beta\beta$. This result shows the scalability of the AXEL detector with ELCC while maintaining high energy resolution. Factors determining the energy resolution were quantitatively evaluated and the result indicates further improvement is feasible. Reconstructed track images show distinctive structures at the endpoint of electron tracks, which will be an important feature to distinguish $0\nu\beta\beta$ signals from gamma-ray backgrounds.Comment: 33 pages, 24 figures, preprint accepted by PTE