Exploring the white dwarf cooling sequence in Globular Clusters

White dwarfs (WDs) are electron-degenerate structures that are commonly assumed to evolve via a pure cooling process, with no stable thermonuclear activity at work. Their cooling rate is adopted as a cosmic chronometer to constrain the age of several Galactic populations, including the disk, Globular Clusters (GCs) and open clusters. This thesis work is aimed at the study of the WD populations in globular clusters and is articulated in two branches. The first was focused on the study of the bright portion of the WD cooling sequence. By analyzing high resolution UV data acquired with the Hubble Space Telescope (HST), we compared the WD luminosity functions (LFs) in four Galactic GCs (namely M13, M3, NGC6752, and M5) finding an unexpected over-abundance of WDs in M13 and NGC6752 with respect to M3 and M5. Theoretical models suggest that, consistently with the blue-tail horizontal branch (HB) morphology of M13 and NGC6752, this overabundance is due to a population of slowly cooling WDs, i.e., WDs fading more slowly than in a pure cooling process thanks to an extra-energy source provided by stable thermonuclear burning in their residual hydrogen-rich envelope. This is the first empirical evidence of WDs fading at a slower rate than usually assumed, and has a crucial impact on the use of the cooling sequence as a cosmic chronometer. The second branch was focused on the search for the companion star to binary millisecond Pulsars (MSP) in the globular clusters M13 and NGC 6652: the identified companions turned out to be helium-core WDs, and provided a invaluable constraints on the mass of the neutron star and the epoch of the MSP formation

Influence of antiviral therapy on survival of patients with hepatitis B-associated hepatocellular carcinoma undergoing transarterial chemoembolization

Purpose: To examine the prognostic value of antiviral therapy among hepatocellular carcinoma (HCC) patients undergoing transarterial chemoembolization (TACE).Method: A total of 356 patients with HCC undergoing TACE were recruited for the purpose of current study. All the patients were categorized into two groups; antiviral (n = 132) and non-antiviral group (n = 224). All the clinical and laboratory parameters were noted at baseline. Patients were then followed up for five years. The mortality rates in two groups were evaluated with Kaplan-Meier estimate.Results: The average age of the participants was 51.2 ± 6.17 years. A majority (329; 92.4 %) of the patients were male while females constituted only 7.6 %. During five years follow-up period, a total of 274 (76.9 %) died, with 89 patients belonging to the antiviral group while the remaining 185 patients were in the non-antiviral group. Mortality rate significantly differed between the antiviral and non-antiviral groups (67.4 % versus 82.5 %, p = 0.028). The results of Cox regression demonstrated that being a smoker, low serum albumin, local ablation and resection decreased overall survival while female gender, antiviral therapy, and early tumor site-node-metastatis (TNM) staging increased overall survival.Conclusion: Antiviral therapy for underlying hepatitis B in HCC patients undergoing TACE prolongs overall survival and prevents or delays reactivation of tumor.Keywords: Cancer, Chemoembolization, Hepatitis, Hepatocellular carcinoma, Transarterial chemoembolization (TACE

Teleportation of an arbitrary two-particle state via entanglement swapping

A scheme of teleportation of an arbitrary two-particle state is presented when two pairs of entangled particles are used as quantum channels. After the Bell state measurements are operated by the sender, the original state with deterministic probability can be reconstructed by the receiver when a corresponding unitary transformation is followed

Exocyst複合体Sec10サブユニットのX線結晶構造解析

学位の種別: 課程博士審査委員会委員 : （主査）東京大学准教授 深井 周也, 東京大学教授 伊藤 耕一, 東京大学教授 泊 幸秀, 東京大学客員教授 本田 真也, 東京大学准教授 石谷 隆一郎University of Tokyo(東京大学

Analysis of dynamic stability for wind turbine blade under fluid-structure interaction

Aiming at improving vibration performance of 1.5 MW wind turbine blades, the theoretical model and the calculation process of vibration problems under geometric nonlinearity and unidirectional fluid-structure interaction (UFSI) were presented. The dynamic stability analysis on a 1.5 MW wind turbine blade was carried out. Both the maximum brandish displacement and the maximum Mises stress increase nonlinearly with the increase of wind speed. The influences of turbulent effect, wind shear effect and their joint effect on displacement and stress increase sequentially. Furthermore, the stability critical curves are calculated and analyzed. As a result, the stability region is established where the wind turbine blade can run safely

Correlation between Internet Addiction Disorder and Mental Health of Junior Middle School Students in Chengdu

Objective: To study the prevalence and main influencing factors of Internet addiction among junior middle school students in Chengdu, and to provide scientific basis for the prevention and intervention of Internet addiction. Methods: From September to December 2017, 3,607 junior middle school students were randomly selected from 8 middle schools in Chengdu by stratified cluster sampling, and investigated by selfmade questionnaire. SPSS 19.0 software was used for χ 2 test and multiple linear regression analysis. Results: 174 of 3,607 junior middle school students in Chengdu were diagnosed with Internet addiction, and the detection rate of Internet addiction was 4.8%. There were significant differences in the scores of mental health, learning pressure, parent-child relationship and peer relationship between Internet addiction and non-internet addiction junior middle school students (P < 0.05). The results of multiple linear regression showed that family economic status, learning pressure, depression and anxiety were positively correlated with internet addiction, while parent-child relationship, peer relationship and social support were negatively correlated with Internet addiction (P < 0.05, P < 0.01). Conclusion: The detection rate of Internet addiction among junior middle school students in Chengdu is at a low level. Junior middle school students with low social support and high depression and anxiety have a higher risk of Internet addiction, which can be reduced by improving their mental health

Quantitative Polymerase Chain Reaction Coupled With Sodium Dodecyl Sulfate and Propidium Monoazide for Detection of Viable Streptococcus agalactiae in Milk

Streptococcus agalactiae is an important pathogen causing bovine mastitis. The aim of this study was to develop a simple and specific method for direct detection of S. agalactiae from milk products. Propidium monoazide (PMA) and sodium dodecyl sulfate (SDS) were utilized to eliminate the interference of dead and injured cells in qPCR. Lysozyme (LYZ) was adopted to increase the extraction efficiency of target bacteria DNA in milk matrix. The specific primers were designed based on cfb gene of S. agalactiae for qPCR. The inclusivity and exclusivity of the assay were evaluated using 30 strains. The method was further determined by the detection of S. agalactiae in spiked milk. Results showed significant differences between the SDS–PMA–qPCR, PMA–qPCR and qPCR when a final concentration of 10 mg/ml (R2 = 0.9996, E = 95%) of LYZ was added in DNA extraction. Viable S. agalactiae was effectively detected when SDS and PMA concentrations were 20 μg/ml and 10 μM, respectively, and it was specific and more sensitive than qPCR and PMA–qPCR. Moreover, the SDS–PMA–qPCR assay coupled with LYZ was used to detect viable S. agalactiae in spiked milk, with a limit of detection of 3 × 103 cfu/ml. Therefore, the SDS–PMA–qPCR assay had excellent sensitivity and specificity for detection of viable S. agalactiae in milk