169 research outputs found
Current Femoral Stem Fixation Selection in Hip-Fracture Bipolar Hemiarthroplasties, and Factors Affecting Surgeonsā Confidence in Their Ability to Teach about Cemented Stems: A Questionnaire in a Region of Japan with Super-Aged Patients
Japanās hip fracture management guidelines now recommend the use of cemented stems in cases of bone fragility. However, the current stem selection practices in bipolar hemiarthroplasty (BHA) in a super-aging area in Japan remain unclear. This study aimed to examine the stem selection policies, the surgeonsā concerns about cemented stems, and factors affecting their confidence in their ability to coach others on cemented stem procedures. Ninety-four orthopedic surgeons (27 facilities) responded to our web-based questionnaire conducted in January/February 2022. Cementless stem was the first choice of 97.8% of the surgeons; <15% of the respondents expected to increase their use of cemented stems in the future. The cement technique was the greatest concern; almost half of the surgeons described having insufficient experience with cemented stems. The factor that most affected the surgeonsā expertise in using cemented stems is the number of surgeries they had conducted with a cemented stem (multivariable analysis odds ratio 8.42, p=0.001). Greater experience was associated with increased expertise of the surgeons in using cemented stems, with a threshold of 11 cases showing sensitivity of 41.7% and specificity of 98.3% for their confidence to instruct cemented stems
Six-month low level chlorine dioxide gas inhalation toxicity study with two-week recovery period in rats
<p>Abstract</p> <p>Background</p> <p>Chlorine dioxide (CD) gas has a potent antimicrobial activity at extremely low concentration and may serve as a new tool for infection control occupationally as well as publicly. However, it remains unknown whether the chronic exposure of CD gas concentration effective against microbes is safe. Therefore, long-term, low concentration CD gas inhalation toxicity was studied in rats as a six-month continuous whole-body exposure followed by a two-week recovery period, so as to prove that the CD gas exposed up to 0.1 ppm (volume ratio) is judged as safe on the basis of a battery of toxicological examinations.</p> <p>Methods</p> <p>CD gas at 0.05 ppm or 0.1 ppm for 24 hours/day and 7 days/week was exposed to rats for 6 months under an unrestrained condition with free access to chow and water in a chamber so as to simulate the ordinary lifestyle in human. The control animals were exposed to air only. During the study period, the body weight as well as the food and water consumptions were recorded. After the 6-month exposure and the 2-week recovery period, animals were sacrificed and a battery of toxicological examinations, including biochemistry, hematology, necropsy, organ weights and histopathology, were performed.</p> <p>Results</p> <p>Well regulated levels of CD gas were exposed throughout the chamber over the entire study period. No CD gas-related toxicity sign was observed during the whole study period. No significant difference was observed in body weight gain, food and water consumptions, and relative organ weight. In biochemistry and hematology examinations, changes did not appear to be related to CD gas toxicity. In necropsy and histopathology, no CD gas-related toxicity was observed even in expected target respiratory organs.</p> <p>Conclusions</p> <p>CD gas up to 0.1 ppm, exceeding the level effective against microbes, exposed to whole body in rats continuously for six months was not toxic, under a condition simulating the conventional lifestyle in human.</p
Electrostatic Discharge Ground Test of a Polar Orbit Satellite Solar Panel
The Advanced Land Observing Satellite that was launched by the Japan Aerospace Exploration Agency in 2006 carries a large solar-array paddle of 22 times 3 m in polar orbit. The wake side of the solar paddle can be charged to a negative value exceeding -1000 V. Numerical simulations and laboratory experiments are carried out to investigate charging and arcing phenomena on the backside of the solar paddle that has exposed bypass diode boards and silver-Teflon thermal film. Possibility of secondary arc and surge voltage between hot and return ends of power circuit has been investigated. The authors irradiate solar-panel coupons with an electron beam to simulate charging situation near the North Pole. Surface flashover is observed once the insulator potential exceeds -7000 V. The authors have also tested charging situation near the South Pole where carbon fiber-reinforced plastics surface facing dense ionospheric plasma may arc easily once a satellite potential drops to -80 or -90 V. The solar-paddle design has been modified to increase the safety margin against arcing, and tests have been carried out to identify the strength limit under extremely harsh test environment
Spatially resolved metabolic distribution for unraveling the physiological change and responses in tomato fruit using matrix-assisted laser desorption/ionizationāmass spectrometry imaging (MALDIāMSI)
Information on spatiotemporal metabolic behavior is indispensable for a precise understanding of physiological changes and responses, including those of ripening processes and wounding stress, in fruit, but such information is still limited. Here, we visualized the spatial distribution of metabolites within tissue sections of tomato (Solanum lycopersicum L.) fruit using a matrix-assisted laser desorption/ionizationāmass spectrometry imaging (MALDIāMSI) technique combined with a matrix sublimation/recrystallization method. This technique elucidated the unique distribution patterns of more than 30 metabolite-derived ions, including primary and secondary metabolites, simultaneously. To investigate spatiotemporal metabolic alterations during physiological changes at the whole-tissue level, MALDIāMSI was performed using the different ripening phenotypes of mature green and mature red tomato fruits. Although apparent alterations in the localization and intensity of many detected metabolites were not observed between the two tomatoes, the amounts of glutamate and adenosine monophosphate, umami compounds, increased in both mesocarp and locule regions during the ripening process. In contrast, malate, a sour compound, decreased in both regions. MALDIāMSI was also applied to evaluate more local metabolic responses to wounding stress. Accumulations of a glycoalkaloid, tomatine, and a low level of its glycosylated metabolite, esculeoside A, were found in the wound region where cell death had been induced. Their inverse levels were observed in non-wounded regions. Furthermore, the amounts of both compounds differed in the developmental stages. Thus, our MALDIāMSI technique increased the understanding of the physiological changes and responses of tomato fruit through the determination of spatiotemporally resolved metabolic alterations
Neurotrophic sesterterpenes isolated from a marine sponge, Spongia sp.
éę²¢å¤§å¦å¤§å¦é¢čŖē¶ē§å¦ē ē©¶ē§ēēę“»ę§ē©č³Ŗē§å¦éę²¢å¤§å¦č¬å¦éØThe MeOH extract of a marine sponge of the genus Spongia showed neurotrophic activity in pheochromocytoma (PC-12) cells. Purification of the extract afforded a new sesterterpene, deacetoxyscalarin (1), along with five known sesterterpenes (2-6). Among them, 2-6 induced neurite outgrowth in PC-12 cells at the concentration of 50 Ī¼g/mL but 1 was inactive. Ā© 2006 The Japan Institute of Heterocyclic Chemistry
Synchronous Total Occlusion of the Celiac Axis and Superior Mesenteric Artery: An Autopsy Case
Acute mesenteric ischemia (AMI) is often caused by superior mesenteric artery (SMA) embolization. We report a rare case of synchronous celiac axis and SMA embolization in an elderly woman with initially mild abdominal pain. Ultimately, a second contrast-enhanced computed tomography revealed extensive necrosis from the stomach to the transverse colon together with liver ischemia due to hours of occlusion. Multiorgan failure made palliation the only option, and she died the following evening. Autopsy revealed a fragile atherosclerosis-asso-ciated thrombus. Careful examination and repeat diagnostic tests should be performed in patients with mild abdominal symptoms at risk for AMI
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