17 research outputs found

    A FORMULA FOR PREDICTION OF FREQUENCY OF TONAL SOUND IN CAVITY FLOWS WITH ACOUSTIC RESONANCE

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    ABSTRACT Self-sustained oscillations with tonal sound in flows over a cavity are investigated by experiments using a wind tunnel and direct numerical simulation of flow and acoustic fields. The effects of the length-to-depth ratio of the cavity and the ratio of the cavity length L to the momentum thickness of the incoming boundary layer on the mode of the oscillations are clarified. The simultaneous measurements of flow pattern and sound pressure are also performed. The results show that a time lag between the generation of an expansion wave due to the collision of a vortex with the downstream edge and the radiation of the expansion wave from the cavity becomes larger for the cavity flow with the acoustic resonance. The computational results explain why the delay becomes larger. Moreover, considering this delay, a new formula for the frequency of the tonal sound in cavity flows with the acoustic resonance is proposed. The frequencies predicted by this formula agree well with those measured

    ACPA-negative RA consists of two genetically distinct subsets based on RF positivity in Japanese.

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    HLA-DRB1, especially the shared epitope (SE), is strongly associated with rheumatoid arthritis (RA). However, recent studies have shown that SE is at most weakly associated with RA without anti-citrullinated peptide/protein antibody (ACPA). We have recently reported that ACPA-negative RA is associated with specific HLA-DRB1 alleles and diplotypes. Here, we attempted to detect genetically different subsets of ACPA-negative RA by classifying ACPA-negative RA patients into two groups based on their positivity for rheumatoid factor (RF). HLA-DRB1 genotyping data for totally 954 ACPA-negative RA patients and 2,008 healthy individuals in two independent sets were used. HLA-DRB1 allele and diplotype frequencies were compared among the ACPA-negative RF-positive RA patients, ACPA-negative RF-negative RA patients, and controls in each set. Combined results were also analyzed. A similar analysis was performed in 685 ACPA-positive RA patients classified according to their RF positivity. As a result, HLA-DRB1*04:05 and *09:01 showed strong associations with ACPA-negative RF-positive RA in the combined analysis (p = 8.8×10(-6) and 0.0011, OR: 1.57 (1.28-1.91) and 1.37 (1.13-1.65), respectively). We also found that HLA-DR14 and the HLA-DR8 homozygote were associated with ACPA-negative RF-negative RA (p = 0.00022 and 0.00013, OR: 1.52 (1.21-1.89) and 3.08 (1.68-5.64), respectively). These association tendencies were found in each set. On the contrary, we could not detect any significant differences between ACPA-positive RA subsets. As a conclusion, ACPA-negative RA includes two genetically distinct subsets according to RF positivity in Japan, which display different associations with HLA-DRB1. ACPA-negative RF-positive RA is strongly associated with HLA-DRB1*04:05 and *09:01. ACPA-negative RF-negative RA is associated with DR14 and the HLA-DR8 homozygote

    Epidemiology of Infectious Hepatitis 1st. Chapter Epidemiologic Observations for Infectious Hepatitis in Akaiwa District (No. 1)

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    Since August 1951 to Feb. 1953, there was a great epidemic of serious infectious hepatitis over the area including Toyota, Onoda, Kama villages in Akaiwa County, as well as Kumayama village in wake County; observing its state, the following results were obtained. 1. Death toll has amounted to 13, out of 93 patients: its mortality rate, 13.98%; in number of the patients, Kama at the top, next, Toyoda, Onoda and Kumayama village, in literal order. 2. The epidemic took the direction, from the south extending to the north in a slow march, taking a hamlet as unit, showed a lack of specific seasonal occurence. 3. As to age, it has ranged roughly from 10 to 60, amid which 21-30 figured out as top years; below 10, only 4 cases; above 70, 5 cases. As to sex, almost similar in number. 4. As to profession, principally, farming people; as one can suppose from its locality. In making investigations into the cause of disease. certain consideration must be taken on the great responsibility imposed on farmers' wives. 5. The infection for this disease was classified as village infection or familiary infection; among 22 cases (23.4% of total patients) of familary infection, there were 4 families, each yielding even 3 sickened members; 5 families whose two members taken infection; in total, amnunted to 9 families. Among these tribal infection, report has been submitted about 1 family whose infection tract was clearly traced, as well as a family in which, if man did not expose certain inapparent infections, all cases have proved utterly whimsical. 6. The incubation period for this disease may probably be estimated to be about 24-27 days, if it may be supposed from these infectious state, and would be considered perorale infection

    Genetic Polymorphisms of the Human PNPLA3 Gene Are Strongly Associated with Severity of Non-Alcoholic Fatty Liver Disease in Japanese

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    Nonalcoholic fatty liver disease (NAFLD) includes a broad range of liver pathologies from simple steatosis to cirrhosis and fibrosis, in which a subtype accompanying hepatocyte degeneration and fibrosis is classified as nonalcoholic steatohepatitis (NASH). NASH accounts for approximately 10-30% of NAFLD and causes a higher frequency of liver-related death, and its progression of NASH has been considered to be complex involving multiple genetic factors interacting with the environment and lifestyle.To identify genetic factors related to NAFLD in the Japanese, we performed a genome-wide association study recruiting 529 histologically diagnosed NAFLD patients and 932 population controls. A significant association was observed for a cluster of SNPs in PNPLA3 on chromosome 22q13 with the strongest p-value of 1.4 × 10(-10) (OR = 1.66, 95%CI: 1.43-1.94) for rs738409. Rs738409 also showed the strongest association (p = 3.6 × 10(-6)) with the histological classifications proposed by Matteoni and colleagues based on the degree of inflammation, ballooning degeneration, fibrosis and Mallory-Denk body. In addition, there were marked differences in rs738409 genotype distributions between type4 subgroup corresponding to NASH and the other three subgroups (p = 4.8 × 10(-6), OR = 1.96, 95%CI: 1.47-2.62). Moreover, a subgroup analysis of NAFLD patients against controls showed a significant association of rs738409 with type4 (p = 1.7 × 10(-16), OR = 2.18, 95%CI: 1.81-2.63) whereas no association was obtained for type1 to type3 (p = 0.41). Rs738409 also showed strong associations with three clinical traits related to the prognosis of NAFLD, namely, levels of hyaluronic acid (p = 4.6 × 10(-4)), HbA1c (p = 0.0011) and iron deposition in the liver (p = 5.6 × 10(-4)).With these results we clearly demonstrated that Matteoni type4 NAFLD is both a genetically and clinically different subset from the other spectrums of the disease and that the PNPLA3 gene is strongly associated with the progression of NASH in Japanese population

    A large-scale association study identified multiple HLA-DRB1 alleles associated with ACPA-negative rheumatoid arthritis in Japanese subjects.

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    [Background] HLA-DRB1 is associated with rheumatoid arthritis (RA). However, it has recently been suggested that HLA-DRB1 is only associated with patients with RA who have anticitrullinated peptide/protein antibodies (ACPA), which are specific to RA. [Objective] To elucidate whether specific HLA-DR alleles are associated with ACPA-negative RA development. [Methods] HLA-DRB1 typing was carried out in 368 Japanese ACPA-negative patients with RA and 1508 healthy volunteers as the first set, followed by HLA-DRB1 typing of 501 cases and 500 controls as the second set. The HLA-DRB1 allele frequency and diplotype frequency were compared in each group, and the results of the two studies were combined to detect HLA-DRB1 alleles or diplotypes associated with ACPA-negative RA. [Results] HLA-DRB1*12:01 was identified as a novel susceptibility allele for ACPA-negative RA (p=0.000088, OR=1.72, 95% CI 1.31 to 2.26). HLA-DRB1*04:05 and *14:03 showed moderate associations with ACPA-negative RA (p=0.0063, OR=1.26, 95% CI 1.07 to 1.49 and p=0.0043, OR=1.81, 95% CI 1.20 to 2.73, respectively). The shared epitope was weakly associated with ACPA-negative RA, but no dosage effect was detected (p=0.016, OR=1.17, 95% CI 1.03 to 1.34). A combination of HLA-DRB1*12:01 and DRB1*09:01 showed a strong association with susceptibility to ACPA-negative RA (p=0.00013, OR=3.62, 95% CI 1.79 to 7.30). Homozygosity for HLA-DR8 was significantly associated with ACPA-negative RA (p=0.0070, OR=2.16, 95% CI 1.22 to 3.82). It was also found that HLA-DRB1*15:02 and *13:02 were protective against ACPA-negative RA (p=0.00010, OR=0.68, 95% CI 0.56 to 0.83 and p=0.00059, OR=0.66, 95% CI 0.52 to 0.84, respectively). [Conclusions] In this large-scale association study multiple alleles and diplotypes were found to be associated with susceptibility to, or protection against, ACPA-negative RA
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