18 research outputs found
Sunspot Observations by Hisako Koyama: 1945-1996
The sunspot record is the only observational tracer of solar activity that
provides a fundamental, multi-century reference. Its homogeneity has been
largely maintained with a succession of long-duration visual observers. In this
paper, we examine observations of one of the primary reference sunspot
observers, Hisako Koyama. By consulting original archives of the National
Museum of Nature and Science of Japan (hereafter, NMNS), we retrace the main
steps of her solar-observing career, from 1945 to 1996. We also present the
reconstruction of a full digital database of her sunspot observations at the
NMNS, with her original drawings and logbooks. Here, we extend the availability
of her observational data from 1947-1984 to 1945-1996. Comparisons with the
international sunspot number (version 2) and with the group sunspot number
series show a good global stability of Koyama's observations, with only
temporary fluctuations over the main interval 1947-1982. Identifying drawings
made by alternate observers throughout the series, we find that a single
downward baseline shift in the record coincides with the partial contribution
of replacement observers mostly after 1983. We determine the correction factor
to bring the second part (1983-1996) to the same scale with Koyama's main
interval (1947-1982). We find a downward jump by 9% after 1983, which then
remains stable until 1996. Overall, the high quality of Koyama's observations
with her life-long dedication leaves a lasting legacy of this exceptional
personal achievement. With this comprehensive recovery, we now make the
totality of this legacy directly accessible and exploitable for future
research.Comment: Main text 31 pages, references 6 pages, 13 figures, 3 tabes, accepted
for publication in Monthly Notices of the Royal Astronomical Society, 202
Endosonography-Guided Pancreatic Duct Drainage for Chronic Pancreatitis: A Case Report and Review
A 50-year-old man was admitted to our department, complaining of epigastric pain and high fever. CT revealed a pseudocyst at the pancreatic head with upstream dilatation of the pancreatic duct (PD) and fluid collection surrounding the pancreas. Endosonography-guided PD drainage (ESPD) was performed because of unsuccessful ERCP. With a curved linear array echoendoscope, a 7.2 F catheter was placed in the PD. Laboratory data showed improvement in a few days and revealed disappearance of the fluid collection. Ten days after ESPD, a 7 F stent was placed in the PD via the puncture tract across the papilla of Vater followed by transpapillary replacement with a 10 F stent. CT showed a reduction in diameter of the PD and disappearance of the pseudocyst. ESPD is a feasible and useful procedure in selected patients with chronic pancreatitis showing stenosis of the main PD when transpapillary approach is impossible
Newly Developed Fully Covered Metal Stent for Unresectable Malignant Biliary Stricture
We herein report two patients with unresectable malignant biliary stricture who underwent stenting with a newly developed fully-covered metal stent. In the first case of lower-middle bile duct cancer, a stent was placed through the stenosis. In the second case of middle bile duct stricture due to lymph node metastases from gallbladder cancer, a stent was placed in the bile duct across the stenosis. No procedure-related complications were observed. Unevenness of the outer surface and a low shortening ratio are expected to lessen the occurrence of complications characteristic of covered metal stents such as stent migration and bile duct kinking
Association between intercondylar notch narrowing and bilateral anterior cruciate ligament injuries in athletes
Intercondylar notch narrowing is a risk factor for anterior cruciate ligament (ACL) injuries, but it is unclear whether a narrow intercondylar notch correlates with bilateral ACL injuries.To determine whether a narrow intercondylar notch is associated with bilateral ACL knee injuries in athletes, using magnetic resonance imaging (MRI) and radiography to investigate the notch size.A retrospective case-control study.This was a comparative cohort study on 50 subjects of which 25 patients with sport trauma-associated bilateral ACL injuries, 30 with unilateral ACL injuries, and 20 healthy subjects. the notch width index (NWI) was measured as the ratio of the width of the intercondylar notch to the femoral condylar width on radiography and the MRI slice containing the region near the ACL attachment site on the femoral side (NWI-A) and on the following posterior slice (NWI-P).The mean NWI values on radiography were 0.257 (SD 0.040), 0.332 (SD 0.036), and 0.341 (SD 0.027) in the bilateral, unilateral, and control groups, respectively, with significant differences between the bilateral and unilateral groups and the bilateral and healthy groups. On MRI, the mean NWI-A values were 0.236 (SD 0.025), 0.243 (SD 0.048), and 0.266 (SD 0.030), respectively, with a significant difference between the bilateral and healthy groups. the mean NWI-P values were 0.239 (SD 0.021), 0.258 (SD 0.038), and 0.273 (SD 0.033), respectively, with significant differences between the bilateral and unilateral groups and the unilateral and healthy groups. A cutoff value of 0.25 for NWI-P gave an odds ratio of 22.667 for the risk of developing bilateral ACL knee injuries.The intercondylar notch was significantly narrower in subjects with bilateral ACL injuries than in healthy subjects. NWI measurement using coronal MRI is useful for judging intercondylar notch narrowing. the risk for ACL injuries is very high when NWI is a parts per thousand currency sign0.25. Preventive measures for the unaffected knee are required for patients with a narrow intercondylar notch.Nihon Univ, Dept Orthopaed Surg, Sch Med, Itabashi Ku, Tokyo 1738610, JapanNihon Univ, Dept Orthopaed Surg, Nerima Hikarigaoka Hosp, Nerima Ku, Tokyo 1790072, JapanHonjo Gen Hosp, Dept Orthopaed Surg, Saitama, JapanUniversidade Federal de São Paulo, Div Phys Med & Rehabil, Dept Orthopaed Surg, São Paulo, BrazilUniversidade Federal de São Paulo, Div Phys Med & Rehabil, Dept Orthopaed Surg, São Paulo, BrazilWeb of Scienc
Pancreatic guidewire placement for achieving selective biliary cannulation during endoscopic retrograde cholangio-pancreatography
AIM: To investigate the frequency and risk factors for acute pancreatitis after pancreatic guidewire placement (P-GW) in achieving cannulation of the bile duct during endoscopic retrograde cholangio-pancreatography (ERCP)