A Study on a High Frequency Application of Thyristor

Static switches utilizing thyristor capable of switching at high frequency are described. A brief summary of the experimental operation of the device is included, followed by an analysis of the static switches. Design procedures and graphs are developed that make possible the design of such static switches based upon design criteria.Article信州大学工学部紀要 21: 11-20 (1966)departmental bulletin pape

Japan's Deflation, Problems in the Financial System, and Monetary Policy

This paper offers three analyses of Japan's macroeconomic experience during the post-1990 period. First, we analyze various facets of deflation during the period, arguing that the deflation of general prices has by no means been a major factor for the stagnating economy. In contrast, the deflation of asset prices was closely related to the economic difficulty of the period. In particular, the negative shocks generated by sharp declines in asset prices in the early 1990s have been propagated and amplified by their interaction with the deterioration in the condition of the financial system. Some statistical evidence supports this view. Second, we analyze the effects of monetary policy adopted by the Bank of Japan (BOJ) to fight deflation since the late 1990s. Given that short-term interest rates were already nearly zero in the mid-1990s, policy measures have focused on creating monetary easing effects beyond those created by zero interest rates alone. We show that the zero interest rate policy, which includes a commitment to maintain a zero interest rate for a longer period than that suggested by a baseline monetary policy rule, has produced strong effects on expected future short-term interest rates and thus the entire yield curve. Third, we argue that the BOJ has successfully prevented a repetition of the 1997-98 type liquidity crisis by directing market operations at addressing the financial-sector problems. These operations have taken the form of containing risk and liquidity premiums, particularly in the money market, through proactive provision of liquidity as well as the BOJ's own risk- taking activity.

Long-term results of the open stent-grafting technique for extended aortic arch disease

ObjectiveThis report elucidates the long-term safety and effectiveness of extended aortic arch replacement with an open stent-grafting technique from our 12 years of experience.MethodsFrom 1994 to 2004, 126 patients (mean age 67.8 years) with different pathologic conditions of the aortic arch with extension to the descending aorta (57 dissections [acute/chronic = 31/26] and 69 aneurysms) were operated on with an open stent-grafting technique. During deep hypothermic circulatory arrest with selective cerebral perfusion, the stent graft was delivered through the transected proximal aortic arch, and arch replacement with a 4-branched prosthesis was performed.ResultsOperative mortality within 30 days was 3.2%. Perioperative morbidity included 7 (5.6%) strokes and 8 (6.3%) spinal injuries (paraplegia in 3, transient paraparesis in 5). Sixty-three percent of the patients were extubated within 24 hours. In long-term follow-up (mean 60.4 ± 36.5 months, maximum 153 months), survival was 81.1%, 63.3%, and 53.7% at 1, 5, and 8 years. Five (3.9%) late endoleaks were observed but treated with successful additional endovascular repair. Freedom from endoleaks was 98.0%, 91.1%, and 91.1% for 1, 5, and 8 years, respectively.ConclusionLong-term observation showed safety and good durability of the open stent-grafting technique for aortic arch disease. This technique could be an attractive treatment option for aortic arch aneurysm with distal extension and aortic dissection requiring aortic arch replacement

Increased Tear Fluid Production as a Compensatory Response to Meibomian Gland Loss A Multicenter Cross-sectional Study

PurposeTo compare tear film parameters as well as meibomian gland morphologic features and function among patients with meibomian gland dysfunction (MGD), those with non–Sjögren syndrome aqueous-deficient dry eye (non-SS ADDE), those with non-SS ADDE and MGD, and normal subjects.DesignMulticenter, cross-sectional, observational case series.ParticipantsForty-one eyes of 41 patients (all women; mean age ± standard deviation, 62.1±9.9 years) with non-SS ADDE, 70 eyes of 70 patients (all women; 66.0±8.7 years) with MGD, 17 eyes of 17 patients (all women; 72.4±7.8 years) with non-SS ADDE and MGD, and 70 eyes of 70 normal control subjects (all women; 65.0±7.1 years).MethodsOcular symptoms were scored from 0 to 14 and lid margin abnormalities from 0 to 4 according to their respective number. Meibomian gland changes were scored from 0 to 6 (meiboscore) on the basis of noncontact meibography findings, and meibum was graded from 0 to 3 depending on its volume and quality. Conjunctival and corneal epithelial damage were scored from 0 to 9 (fluorescein score). Tear film break-up time (TBUT) was measured as an index of tear film stability, and tear fluid production was evaluated with Schirmer's test.Main Outcome MeasuresOcular symptom score, lid margin abnormality score, meiboscore, meibum grade, fluorescein score, TBUT, and Schirmer's test value.ResultsThe ocular symptom score did not differ significantly between the MGD and non-SS ADDE groups (P = 0.762). The lid margin abnormality score, meiboscore, and meibum grade were significantly higher in the MGD group than in the non-SS ADDE group (P = 0.0012, P < 0.0001, and P < 0.0001, respectively). The fluorescein score, TBUT, and Schirmer's test value were significantly worse in the non-SS ADDE group than in the MGD group (P < 0.0001, P = 0.0061, and P < 0.0001, respectively). The meiboscore correlated significantly with Schirmer's test value only in the MGD group (ρ = 0.508, P = 8.3×10−6).ConclusionsAn increase in tear fluid production likely compensates for loss of meibomian glands in individuals with MGD

Structural Determinants of the APOBEC3G N-Terminal Domain for HIV-1 RNA Association

APOBEC3G (A3G) is a cellular protein that inhibits HIV-1 infection through virion incorporation. The interaction of the A3G N-terminal domain (NTD) with RNA is essential for A3G incorporation in the HIV-1 virion. The interaction between A3G-NTD and RNA is not completely understood. The A3G-NTD is also recognized by HIV-1 Viral infectivity factor (Vif) and A3G-Vif binding leads to A3G degradation. Therefore, the A3G-Vif interaction is a target for the development of antiviral therapies that block HIV-1 replication. However, targeting the A3G-Vif interactions could disrupt the A3G-RNA interactions that are required for A3G's antiviral activity. To better understand A3G-RNA binding, we generated in silico docking models to simulate the RNA-binding propensity of A3G-NTD. We simulated the A3G-NTD residues with high RNA-binding propensity, experimentally validated our prediction by testing A3G-NTD mutations, and identified structural determinants of A3G-RNA binding. In addition, we found a novel amino acid residue, I26 responsible for RNA interaction. The new structural insights provided here will facilitate the design of pharmaceuticals that inhibit A3G-Vif interactions without negatively impacting A3G-RNA interactions

JAK2 V617F-Dependent Upregulation of PU.1 Expression in the Peripheral Blood of Myeloproliferative Neoplasm Patients

Myeloproliferative neoplasms (MPN) are multiple disease entities characterized by clonal expansion of one or more of the myeloid lineages (i.e. granulocytic, erythroid, megakaryocytic and mast cell). JAK2 mutations, such as the common V617F substitution and the less common exon 12 mutations, are frequently detected in such tumor cells and have been incorporated into the diagnostic criteria published by the World Health Organization since 2008. However, the mechanism by which these mutations contribute to MPN development is poorly understood. We examined gene expression profiles of MPN patients focusing on genes in the JAK–STAT signaling pathway using low-density real-time PCR arrays. We identified the following 2 upregulated genes in MPN patients: a known target of the JAK–STAT axis, SOCS3, and a potentially novel target, SPI1, encoding PU.1. Induction of PU.1 expression by JAK2 V617F in JAK2-wildtype K562 cells and its downregulation by JAK2 siRNA transfection in JAK2 V617F-positive HEL cells supported this possibility. We also found that the ABL1 kinase inhibitor imatinib was very effective in suppressing PU.1 expression in BCR-ABL1-positive K562 cells but not in HEL cells. This suggests that PU.1 expression is regulated by both JAK2 and ABL1. The contribution of the two kinases in driving PU.1 expression was dominant for JAK2 and ABL1 in HEL and K562 cells, respectively. Therefore, PU.1 may be a common transcription factor upregulated in MPN. PU.1 is a transcription factor required for myeloid differentiation and is implicated in erythroid leukemia. Therefore, expression of PU.1 downstream of activated JAK2 may explain why JAK2 mutations are frequently observed in MPN patients

Virological characteristics of the SARS-CoV-2 Omicron BA.2.75 variant

SARS-CoV-2オミクロンBA.2.75株（通称ケンタウロス）のウイルス学的性状の解明. 京都大学プレスリリース. 2022-10-12.The SARS-CoV-2 Omicron BA.2.75 variant emerged in May 2022. BA.2.75 is a BA.2 descendant but is phylogenetically distinct from BA.5, the currently predominant BA.2 descendant. Here, we show that BA.2.75 has a greater effective reproduction number and different immunogenicity profile than BA.5. We determined the sensitivity of BA.2.75 to vaccinee and convalescent sera as well as a panel of clinically available antiviral drugs and antibodies. Antiviral drugs largely retained potency but antibody sensitivity varied depending on several key BA.2.75-specific substitutions. The BA.2.75 spike exhibited a profoundly higher affinity for its human receptor, ACE2. Additionally, the fusogenicity, growth efficiency in human alveolar epithelial cells, and intrinsic pathogenicity in hamsters of BA.2.75 were greater than those of BA.2. Our multilevel investigations suggest that BA.2.75 acquired virological properties independent of BA.5, and the potential risk of BA.2.75 to global health is greater than that of BA.5