137 research outputs found
Development and Performance Evaluation of High Temperature Electromagnetic Acoustic Transducer
Monitoring techniques are in demand in high temperature metal processing environments such as steel manufacturing facilities or foundries. Important processes that affect the quality of the final product are often carried out under high temperature conditions, and the materials can reach temperatures ranging from 600 to 1500 degrees C. Electromagnetic Acoustic Transducer (EMAT) can provide non-contact measurements, and is suitable for measurements in high temperature. Conventional EMAT uses rare-earth based magnets such as Nd or Sm-Co base ones for its bias magnetic sources, but the operation temperature of these types of magnets are limited by their Curie points. Recently, pulsed electromagnet EMAT which uses iron yoke is developed [1], and it is confirmed that this EMAT can be used up to 600 degrees C. However, to use it in higher temperature, it is supposed that the Curie point of iron yoke becomes a problem.
This study proposes an EMAT that uses an air-cored pulsed electromagnet to overcome the Curie temperature limitations of these devices. For the purpose, we design the air-cored electromagnet, which can apply a sufficiently high magnetic field, and fabricate a prototype EMAT using high temperature materials as shown in Fig. 1. To evaluate the performance of the proposed EMAT, pulse-echo waveforms are measured under high temperature conditions. To increase the signal-to-noise ratio of the echo signals, the pulse-echo waveform is discussed in the frequency. As a result, the echo signals are successfully obtained over the temperature range from RT to 700 degrees C, and the reduction of shear wave velocity with increasing temperature is confirmed as shown in Fig. 2.
This work was performed with partial support from a Grant-in-Aid for Challenging Exploratory Research (grant no. 24656080) from the Japan Society for the Promotion of Science (JSPS), and from the JSPS Core-to-Core Program, A. Advanced Research Networks, “International research core on smart layered materials and structures for energy saving”
A case of sporadic intestinal cryptosporidiosis diagnosed by endoscopic biopsy
Sporadic intestinal cryptosporidiosis is not easily diagnosed and might be overlooked. We present here a case of this disease in a 23-year-old Japanese military man with 3 days of abdominal pain, watery diarrhea, and nausea. The frequency of his diarrhea was more than 10 times per day. After his diarrheal bowel symptoms subsided, a colonoscopy was performed because inflammatory bowel disease was suspected. Although the endoscopic findings indicated non-specific ileitis, intestinal cryptosporidiosis was suspected from the histology of ileal biopsy specimens, and this was confirmed ultrastructurally. At that time, however, the patient was on active duty, and thus it was not possible to confirm this as a definitive diagnosis by an adequate stool examination for cryptosporidium. Routine practitioners should be encouraged to carefully inspect patients for this disease, supported by detailed knowledge of it and its diagnosis. If stool-examination results are negative or are not obtained at first, histological diagnosis by endoscopic biopsy could be a useful way to screen for intestinal cryptosporidiosis. Furthermore, stool or histological examination should be performed in recovered patients because the oocysts may continue to be shed for 1 to 4 weeks after the symptoms disappear. Therefore, endoscopic and histological examinations may be useful tools for the early diagnosis of intestinal cryptosporidiosis, although admittedly they are invasive procedures.</p
Cor Triatriatum in the Adult with Aortic Stenosis and Mitral Stenosis
Background:Cor triatriatum is a rare congenital cardiac anomaly, in which the left atrium or right atrium is separated by an abnormal fibromuscular membrane with one or more restrictive orifices. This condition typically presents in infancy or early childhood and can be associated with other cardiac anomalies.Case presentation:A 75-year-old woman was admitted for exertional dyspnea with moderate aortic and mitral stenosis. As cor triatriatum was revealed by a computed tomography and echocardiography, she was referred to our department for surgery. Aortic valve replacement, mitral valve replacement and excision of the membranous septum in the left atrium was performed. This report presents an incidental findings of cor triatriatum with aortic stenosis, moderate mitral stenosis in septuagenarian.Conclusion:We encountered a rare case of cor triatriatum with aortic stenosis and mitral stenosis in septuagenarian. She was incidentally diagnosed by rheumatic aortic and mitral stenosis which had advanced to moderate level
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Attenuation Of Multiple Nef Functions In HIV-1 Elite Controllers
Background
Impaired HIV-1 Gag, Pol, and Env function has been described in elite controllers (EC) who spontaneously suppress plasma viremia to < 50 RNA copies/mL; however, activity of the accessory protein Nef remains incompletely characterized. We examined the ability of 91 Nef clones, isolated from plasma of 45 EC and 46 chronic progressors (CP), to down-regulate HLA class I and CD4, up-regulate HLA class II invariant chain (CD74), enhance viral infectivity, and stimulate viral replication in PBMC.
Results
In general, EC Nef clones were functional; however, all five activities were significantly lower in EC compared to CP. Nef clones from HLA-B*57-expressing EC exhibited poorer CD4 down-regulation function compared to those from non-B*57 EC, and the number of EC-specific B*57-associated Nef polymorphisms correlated inversely with 4 of 5 Nef functions in these individuals.
Conclusion
Results indicate that decreased HIV-1 Nef function, due in part to host immune selection pressures, may be a hallmark of the EC phenotype
フクマク ハシュ オ トモナッタ コウド シンコウ イガン ニ タイスル TS 1 ニヨル ジュツゼン カガク リョウホウ ノ ユウヨウセイ
TS -1 is an oral anticancer agent developed by utilizing biochemical modulation. We
used TS -1in neoadjuvant chemotherapy for a patient with highly advanced gastric cancer
that was accompanied by peritoneal dissemination. This enabled us to resect tumor.
This patient was a60-year-old woman. Fluoroscopic upper gastrointestinal series revealed
a circumferential, type4lesion extending from the middle of the corpus to the antrum. This
was diagnosed by endoscopy as poorly differentiated adenocarcinoma. CT showed ascites,
thickening of the gastric wall, and direct infiltration into the head of the pancreas. In
endoscopy of the large bowel, a strawberry jelly-like elevation was detected at the ileum.
This was diagnosed as poorly differentiated adenocarcinoma, and considered a metastatic
lesion produced by dissemination. Chest CT showed a single metastasis in the upper lobe
of the right lung. We gave her3cycles of combined TS-1and low-dose CDDP for neoadjuvant
chemotherapy. On laparotomy, we found that there was no ascites, and miliary scars were
present at several sites near the ascending colon. The antrum of the stomach firmly adhered
to the head of the pancreas, and scarred. We judged that the tumor was resectable, and
performed distal gastrectomy(D2)plus ileocecal resection(D2).
In histopathological examination, poorly differentiated adenocarcinoma was detected
only on a part of the muscular layer in the lesser curvature and posterior wall of the corpus,
and marked fibrosis was observed in the submucosal layer. The effect of chemotherapy was
histologically evaluated as grade2. The tumor was diagnosed as poorly differentiated
adenocarcinoma(por), with muscularis propria(mp), lymph invasion2(ly2),vein invasion
0(v0)and degree of lymph node metastasis2(+)[n2(+)]. Tubular adenocarcinoma was
detected in a part of the submucosal layer of the ileum. The patient was alive with cancer
as of27months after operation
チョメイナ ノウホウ ケイセイ オ トモナッタ カンサイボウ ガン ノ 1ジケンレイ
It is said that in hepatocellular carcinoma, necrosis is liable to occur in the center and
the percentage of cystic formation is comparatively low, but as we have experienced one
case of hepatocellular carcinoma associated with marked cystic formation, we reported it.
The patient was a female aged70years. Because general fatigue and anorexia occurred,
Abdominal CT test was conducted and hepatic mass was pointed out. Contrast-CT test
showed a tumor of6cm in diameter in the medial segment of the left lobe of the liver. As
the border was stained with arterial phase, the center was not imaged and the tumor was
diagnosed as vascular proliferating type hepatic tumor associated with marked cystic
change. MRI test showed that the border of the tumor was lobular and part thereof was of
septal structure. The tumor was diagnosed as hepatocellular carcinoma associated with
bleeding in tumor, hepatic cystadenocarcinoma or hepatic sarcoma. Abdominal angiography
showed not only marked vascular proliferation and tumor stain in the area of the middle
hepatic artery but also early venous return, and the middle hepatic vein was clearly imaged.
The tumor size was 5×5×4cm in size and was in contact with the middle hepatic vein
but it did not invade the vein. Left hepatic lobectomy was performed. Histopathologically
the center of the tumor was cystic with colliquative necrosis. The tumor had the trabecular
structure and the tumor cell was consisted of clear cell. The tumor was thus diagnosed as
poorly differentiated hepatocellular carcinoma. Postoperative course was good and the patient
was discharged from our hospital on the19th day after operation. At the moment when19
months have passed since the operation, the patient is alive without any recurrence of
carcinoma
Neuropeptide Y mediates orexin A-mediated suppression of pulsatile gonadotropin-releasing hormone secretion in ovariectomized rats
Objectives : Reproductive functions are influenced by various feeding regulators.
Orexin, which is one of orexinergic peptides, suppresses the pulsatile secretion of
luteinizing hormone (LH) in bilaterally ovariectomized (OVX) rats. However, the mechanism
of this effect is still not clear. To investigate whether neuropeptide Y (NPY) is involved
in the orexin A-mediated suppression of pulsatile LH secretion, we evaluated the
effects of NPY antibody on the suppressive effect of orexin A. Methods : Orexin A was administered
intracerebroventricularly (icv) and NPY antibody (NPY-Ab) was injected before
icv administration of orexin A in OVX rats. Pulsatile LH secretion was analyzed by
measuring serum LH concentrations in the next 2 h in blood samples drawn at 6-min intervals
by radioimmunoassay. Results : Administration of orexin A significantly reduced
the mean LH concentration and LH pulse frequency. Co-administration of NPY antibody
with orexin A significantly restored the suppressive effect of orexin A on the mean LH
concentration and LH pulse frequency. Conclusion : NPY mediated the suppressive effect
of intracerebroventricularly injected orexin A on pulsatile LH secretion, suggesting that
hypothalamic orexin suppressed pulsatile gonadotropin-releasing hormone (GnRH) secretion
via NPY in the hypothalamus of female rats
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