Efficient and precise fabrication of Wolter type-I x-ray mirrors via nickel electroforming replication using quartz glass mandrels.

This study presents an approach for fabricating Wolter type-I mirrors for x-ray telescopes using a nickel electroforming replication process with quartz glass mandrels. The proposed method addresses the challenges encountered in conventional fabrication techniques, which involve using electroless nickel-coated aluminum mandrels that are susceptible to corrosion and thermal deformation. Quartz glass mandrels offer excellent chemical, thermal, and mechanical stability, enabling the efficient production of high-performance mirrors. Wolter type-I mirrors for telescopes possess a large aperture that collects x-ray photons from the universe. However, previous nickel electroforming replication processes using quartz glass mandrels have challenges in fabricating large mirrors, particularly due to bubble pit formation during nickel shell development. In this study, we introduced an efficient pitting inhibition technique via vacuum degassing. This technique facilitates the precise replication of pit-free Wolter type-I mirrors for telescopes using quartz glass mandrels. We demonstrated the fabrication process on a Wolter type-I mirror proposed for FOXSI-4 [(FOXSI) Focusing Optics X-ray Solar Imager], resulting in three mirrors obtained from the same mandrel without repolishing or repairing. The figure error of the mirror was within 1 µm over most areas in both longitudinal and circumferential directions. The ray-tracing simulation indicated that the performance of the mirror was ∼12 arcsec in half-power diameter, comparable to the performance achieved by previous high-resolution x-ray missions.

Fabrication of soft x-ray monolithic Wolter mirror based on surface scanning measurement using touch probe.

The monolithic Wolter mirror is an ideal optical device for focusing soft x rays to a submicron-sized spot, with the advantages of high efficiency, large acceptance, achromaticity, and robustness to alignment error. The fabrication process for this type of mirror has not been established because of the difficulty in highly accurate figure measurement of free-form surfaces with small radii of curvature and steep profiles. In this study, we employed tactile scanning measurement for surface characterization to fabricate a high-precision Wolter mirror. First, it was demonstrated that the touch probe measurement did not leave scratches on the raw surface of the mirror substrate. Next, the measurement capability of the surface profiler was assessed, and the data analysis conditions were determined. Finally, the Wolter mirror was fabricated through repeated figure correction based on the tactile measurement, and the figure error of the final surface was evaluated. Wave-optical simulations that used this error as reference suggested that the size of the beam focused by the mirror was equivalent to the theoretical value at 1000 eV. The reflected image with uniform intensity distribution obtained at SPring-8 also revealed the effectiveness of the present fabrication approach based on tactile measurement.

Serum level of free fatty acids is associated with nocturnal hypoglycemia in cirrhotic patients with HCV infection: a pilot study.

BACKGROUND/AIMS: Nocturnal hypoglycemia is an aggravating factor for liver cirrhosis. However, in patients with compensated liver cirrhosis, a clinical parameter associated with nocturnal hypoglycemia remains unclear. The aim of this study is to investigate a clinical parameter associated with nocturnal hypoglycemia in patients with hepatitis C virus (HCV)-related compensated liver cirrhosis. METHODOLOGY: Twenty patients with HCV-related compensated liver cirrhosis were enrolled in this study. Nocturnal glucose profile was examined by the Continuous Glucose Monitoring System. According to the glucose levels between 21:00 to 6:00, patients were classified into a normoglycemia group (glucose level >70 mg/dL, n=10) or a nocturnal hypoglycemia group (glucose level <70 mg/dL, n=10). Differences in body compositions and biochemical parameters were examined between the two groups. RESULTS: Fifty percent of compensated cirrhotic patients showed nocturnal hypoglycemia. The serum level of free fatty acids, but not any other parameters, was significantly higher in the nocturnal hypoglycemia group compared to that in the normoglycemia group (553 +/- 209 vs. 367 +/- 131 mEq/L; p < 0.05). CONCLUSIONS: Nocturnal hypoglycemia occurred even in compensated cirrhotic patients. Higher serum level of free fatty acids may suggest the presence of nocturnal hypoglycemia in HCV-related compensated cirrhotic patients.

Initial experience with a new peroral electronic pancreatoscope with an accessory channel.

BACKGROUND: A peroral electronic pancreatoscope was previously developed to improve visualization of the pancreatic duct, but this instrument had no accessory channel. METHODS: A new peroral electronic pancreatoscope (2.6-mm external diameter) with an accessory channel (0.5 mm) was developed. Peroral pancreatoscopy or cholangioscopy was performed with this new instrument in 11 patients with various pancreatobiliary diseases. The clinical utility of the new peroral electronic pancreatoscope was assessed, and visualization with this new instrument was compared with that of the prototype. RESULTS: The resolution of the two instrument systems was nearly equal, with that provided by the new peroral electronic pancreatoscope being slightly better. The new peroral electronic pancreatoscope was inserted successfully into the pancreatic or bile duct in 9 of the 11 patients (82%). Observation of a predetermined target and juice collection with direct visualization was successful in 8 of the 9 patients (89%). CONCLUSIONS: The new peroral electronic pancreatoscope with an accessory channel was useful for clinical diagnosis of various pancreatobiliary diseases. Visualization is excellent. Pancreatic juice and other samples can be collected under direct visualization.

A polymorphism of interferon-gamma gene associated with changes of anti-thyrotropin receptor antibodies induced by antithyroid drug treatment for Graves' disease in Japanese patients.

Graves' disease (GD) is an autoimmune disorder with genetic predisposition. Interferon-gamma (IFN-gamma) is an important mediator of inflammatory and immune responses. The aim of the present study was to investigate whether the polymorphism of IFN-gamma gene is associated with the development of GD or with clinical course during the antithyroid drug therapy. We have studied the CA repeat polymorphisms in the first intron of IFN gamma gene in Japanese patients with GD (n = 162) and healthy control subjects without antithyroid autoantibodies or family history of autoimmune disorders (n = 133). There was no difference in allele frequency of IFN-gamma gene polymorphism between patients with GD and control subjects. However, the allele 4 (15 CA repeats) frequency was significantly greater in patients whose antithyrotropin receptor antibody (TRAb) became negative within 3 years by antithyroid drug treatment than those with consistently positive TRAb for more than 3 years (34.1% vs. 15.7%, chi2 = 8.545, p = 0.0035, pc = 0.049). The in vitro production of IFN-gamma by concanavalin A-stimulated peripheral blood mononuclear cells was significantly smaller in control subjects with the allele 4 compared to those with the other alleles. In conclusions, the CA repeat polymorphism of the IFN-gamma gene might be associated with the outcome of anti-thyroid drug treatment.

A case of pseudotumorous pancreatitis that presented unique pancreatoscopic findings with the peroral electronic pancreatoscope.

A 49-year-old man was admitted to Hospital of Kyoto Prefectural University of Medicine complaining of epigastralgia and jaundice. There was a tumor (approximately 30 mm) in the pancreatic head on ultrasound, computed tomography and magnetic resonance imaging. Endoscopic retrograde cholangiopancreatography revealed a stenosis of the main pancreatic duct in the head of the pancreas. Pancreatoscopy with the peroral electronic pancreatoscope (PEPS) was performed to differentiate between pseudotumorous pancreatitis (PTP) and pancreatic carcinoma. The PEPS showed non-erosive erythematous mucosa around the stenosis and this unique finding was different from that of pancreatic carcinoma. Pylorus-preserving pancreatoduodenectomy was performed under the possible diagnosis of carcinoma. As a result, the diagnosis of PTP was confirmed histopathologically. At present, the diagnosis of PTP is difficult because of similar findings with carcinoma in various imaging procedures. However, we consider that detailed observation and accurate morphologic assessment of the main pancreatic duct with the PEPS has the possibility of differentiating PTP from pancreatic carcinoma.

Electronic pancreatoscopy for the diagnosis of pancreatic diseases.

OBJECTIVES: Diagnostic pancreatoscopy was performed in 56 patients using the newly developed peroral electronic pancreatoscope (PEPS). The diagnostic value of the PEPS for pancreatic diseases was evaluated. METHODS: The PEPS (external diameter = 2.1 mm, bidirectional tip deflection) was developed with a minute 50,000-pixel interline charge-coupled device. Pancreatoscopy was performed by means of an endoscopic retrograde approach without sphincterotomy. The cases examined were normal (three), chronic pancreatitis (32), pancreatic cancer (eight), and intraductal papillary mucinous tumors (13). RESULTS: Of the 56 cases, 42 (75%) were adequately seen. In normal cases, fine capillary vessels were clearly visualized on the smooth whitish-pink mucosa. Findings in chronic pancreatitis included protein plugs, calcified stones, rough whitish mucosa, scar formation, edema, erythema, and indistinct capillary appearance. All the stenoses of chronic pancreatitis could be differentiated from those of pancreatic cancer with the PEPS. In the pancreatic cancer cases, all patients had stenoses or duct cutoffs; most cases had friable mucosa with erythema and erosive changes, and a single patient had a compressed pancreatic duct wall covered with normal epithelium. In the cases of intraductal papillary mucinous tumors, papillary tumors were visualized with extreme clarity. In the case of adenocarcinoma, the PEPS revealed oval-shaped tumors with spotty redness or villous tumors with dilation of capillary vessels. Moderate acute pancreatitis was recognized after pancreatoscopy in one of the 56 cases (1.8%). CONCLUSIONS: Electronic pancreatoscopy with the PEPS is feasible in most patients and technically safe, and improves diagnostic yield over conventional pancreatoscopy.

A synthetic prostaglandin E1 analog, alprostadil alfadex, relaxes sphincter of Oddi in humans.

It is well established that prostaglandins (PGs) exert potent pharmacological actions on vascular and nonvascular smooth muscle, although their effects on the sphincter of Oddi (SO) remain to be elucidated. The aim of this study was to investigate the effect of PGE1 on motility of the human SO. Twenty patients appearing for routine endoscopic retrograde cholangiopancreatography (ERCP) examination were studied. Each patient was randomly allocated to receive an intravenous infusion of normal saline (six patients), or alprostadil alfadex, a synthetic PGE1 analog, at a dose of either 0.05 or 0.1 microg/kg/min (seven patients for each condition). Endoscopic biliary manometry was done with a recording of basal SO pressure, amplitude of SO phasic contractions, and phasic contractile frequency before and 5 min after intravenous infusions, using a 4-French microtransducer catheter. There was no significant change in SO motor variables following application of normal saline. Alprostadil alfadex significantly decreased basal SO pressure at a dose of 0.05 microg/kg/min, and significantly decreased all parameters at a dose of 0.1 microg/kg/min. A synthetic PGE1 analog, alprostadil alfadex, effectively inhibits motility of the human SO. This drug may be of clinical application as a SO-relaxing agent.