194 research outputs found

    Comparison of gravity wave propagation directions observed by mesospheric airglow imaging at three different latitudes using the M-transform

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    We developed user-friendly software based on Matsuda et al.'s (2014) 3D-FFT method (Matsuda-transform, M-transform) for airglow imaging data analysis as a function of Interactive Data Language (IDL). Users can customize the range of wave parameters to process when executing the program. The input for this function is a 3-D array of a time series of a 2-D airglow image in geographical coordinates. We applied this new function to mesospheric airglow imaging data with slightly different observation parameters obtained for the period of April–May at three different latitudes: Syowa Station, the Antarctic (69∘&thinsp;S, 40∘&thinsp;E); Shigaraki, Japan (35∘&thinsp;N, 136∘&thinsp;E); and Tomohon, Indonesia (1∘&thinsp;N, 122∘&thinsp;E). The day-to-day variation of the phase velocity spectrum at the Syowa Station is smaller and the propagation direction is mainly westward. In Shigaraki, the day-to-day variation of the horizontal propagation direction is larger than that at the Syowa Station; the variation in Tomohon is even larger. In Tomohon, the variation of the nightly power spectrum magnitude is remarkable, which indicates the intermittency of atmospheric gravity waves (AGWs). The average nightly spectrum obtained from April–May shows that the dominant propagation is westward with a phase speed &lt;50&thinsp;m&thinsp;s−1 at the Syowa Station and east-southeastward with a phase speed of up to ∼80&thinsp;m&thinsp;s−1 in Shigaraki. The day-to-day variation in Tomohon is too strong to discuss average characteristics; however, a phase speed of up to ∼100&thinsp;m&thinsp;s−1 and faster is observed. The corresponding background wind profiles derived from MERRA-2 indicate that wind filtering plays a significant role in filtering out waves that propagate eastward at the Syowa Station. On the other hand, the background wind is not strong enough to filter out relatively high-speed AGWs in Shigaraki and Tomohon and the dominant propagation direction is likely related to the distribution and characteristics of the source region, at least in April and May.</p

    Acute small bowel obstruction as a result of a Meckel's diverticulum encircling the terminal ileum: A case report

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    BACKGROUND: In the developed world, small bowel obstruction accounts for 20% of all acute surgical admissions. The aetiology for majority of these cases includes postoperative adhesions and herniae. However, a relatively uncommon cause is a Meckel's diverticulum. Although this diagnosis is primarily reported in the adolescent population, it should also be considered in adults. CASE PRESENTATION: In the present report, we present a rare case where a fit and healthy 74-year-old gentleman, with no previous history of abdominal surgery, presented with the cardinal symptoms and signs of small bowel obstruction as the result of a Meckel's diverticulum encircling his terminal ileum. Initial investigations included a supine abdominal x-ray showing dilated loops of small bowel and computerised tomographic imaging of the abdomen, which revealed a stricture in the terminal ileum of unknown aetiology. At laparotomy, multiple loops of distended small bowel were seen from the duodeno-jeujenal junction to the terminal ileum, which was encircled by a Meckel's diverticulum. The Meckel's diverticulum was then divided to release the obstruction, mobilised and subsequently removed. Finally, the small bowel contents were decompressed into the stomach and the nasogastric tube aspirated, before returning the loops of bowel into the abdomen in sequence. The patient made a good postoperative recovery and was discharged home 5 days later. CONCLUSION: This report highlights the importance of considering a Meckel's diverticulum as a cause of small bowel obstruction in individuals from all age groups and especially in a person with no previous abdominal pathology or surgery

    Seasonal variation of carbon monoxide in northern Japan: Fourier transform IR measurements and source-labeled model calculations

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    Tropospheric carbon monoxide (CO) was measured throughout 2001 using groundbased Fourier transform IR (FTIR) spectrometers at Moshiri 44.4N and Rikubetsu 43.5N) observatories in northern Japan, which are separated by 150 km. Seasonal and day-to-day variations of CO are studied using these data, and contributions from various CO sources are evaluated using three-dimensional global chemistry transport model (GEOS-CHEM) calculations. Seasonal maximum and minimum FTIR-derived tropospheric CO amounts occurred in April and September, respectively. The ratio of partial column amounts between the 0–4 and 0–12 km altitude ranges is found to be slightly greater in early spring. The GEOS-CHEM model calculations generally reproduce these observed features. Source-labeled CO model calculations suggest that the observed seasonal variation is caused by seasonal contributions from various sources, in addition to a seasonal change in chemical CO loss by OH. Changes in meteorological fields largely control the relative importance of various source contributions. The contributions from fossil fuel (FF) combustion in Asia and photochemical CO production have the greatest yearly averaged contribution at 1 km among the CO sources (31% each). The Asian FF contribution increases from winter to summer, because weak southwesterly wind in summer brings more Asian pollutants to the observation sites. The seasonal variation from photochemical CO production is small (±17% at 1 km), likely because of concurrent increases (decreases) of photochemical production and loss rates in summer (winter), with the largest contribution between August and December. The contribution from intercontinental transport of European FF combustion CO is found to be comparable to that of Asian FF sources in winter. Northwesterly wind around the Siberian high in this season brings pollutants from Europe directly to Japan, in addition to southward transport of accumulated pollution from higher latitudes. The influences are generally greater at lower altitudes, resulting in a vertical gradient in the CO profile during winter. The model underestimates total CO by 12–14% between March and June. Satellite-derived fire-count data and the relationship between FTIR-derived HCN and CO amounts are generally consistent with biomass burning influences, which could have been underestimated by the model calculations

    Successful Treatment for Hepatic Encephalopathy Aggravated by Portal Vein Thrombosis with Balloon-Occluded Retrograde Transvenous Obliteration

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    This report presents the case of a 78-year-old female with hepatic encephalopathy due to an inferior mesenteric venous-inferior vena cava shunt. She developed hepatocellular carcinoma affected by hepatitis C virus-related cirrhosis and underwent posterior sectionectomy. Portal vein thrombosis developed and the portal trunk was narrowed after hepatectomy. Portal vein thrombosis resulted in high portal pressure and increased blood flow in an inferior mesenteric venous-inferior vena cava shunt, and hepatic encephalopathy with hyperammonemia was aggravated. The hepatic encephalopathy aggravated by portal vein thrombosis was successfully treated by balloon-occluded retrograde transvenous obliteration via a right transjugular venous approach without the development of other collateral vessels

    Insufficient maintenance DNA methylation is associated with abnormal embryonic development

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    <p>Abstract</p> <p>Background</p> <p>Early pregnancy loss (EPL) is a frustrating clinical problem, whose mechanisms are not completely understood. DNA methylation, which includes maintenance methylation and <it>de novo </it>methylation directed by DNA methyltransferases (DNMTs), is important for embryo development. Abnormal function of these DNMTs may have serious consequences for embryonic development.</p> <p>Methods</p> <p>To evaluate the possible involvement of DNA methylation in human EPL, the expression of DNMT proteins and global methylation of DNA were assessed in villous or decidua from EPL patients. The association of maintenance methylation with embryo implantation and development was also examined.</p> <p>Results</p> <p>We found that DNMT1 and DNMT3A were both expressed in normal human villous and decidua. DNMT1 expression and DNA global methylation levels were significantly down-regulated in villous of EPL. DNMT3A expression was not significantly changed in the EPL group compared to controls in either villous or decidua. We also found that disturbance of maintenance methylation with a DNMT1 inhibitor may result in a decreased global DNA methylation level and impaired embryonic development in the mouse model, and inhibit <it>in vitro </it>embryo attachment to endometrial cells.</p> <p>Conclusions</p> <p>Our results demonstrate that defects in DNA maintenance methylation in the embryo, not in the mother, are associated with abnormal embryonic implantation and development. The findings of the current study provide new insights into the etiology of EPL.</p
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