Essays in Capital Mobility, Growth, and Macroeconomic Volatility

This dissertation comprises three chapters in international macroeconomics. Specifically, we focus on international financial integration and its linkage to economic growth and volatility. In Chapter 1, we revisit the Feldstein-Horioka (1980) puzzle that saving-investment correlation exhibits a pattern contrary to expectation, being higher among the OECD countries that are more financially integrated and lower among emerging markets economies with less financial integration and greater capital controls. We find that the evolution of FH coefficient is highly consistent with increased financial integration over time, thus resolving the puzzle dynamically. We also explain the cross-country component of the puzzle by showing that financial market imperfections influence how well FH coefficient measures capital mobility. In chapter 2, we study the linkage between financial integration and economic growth. We develop a dynamic stochastic model that generalizes Obstfeld\u27s (1994) model by incorporating the costs from systemic risk besides the well-known benefit from risk-sharing by Obstfeld (1994). We show that potential cost from the systemic risk could lower the benefit from risk diversification in an integrated financial market. By using the stock market data from Taiwan and US to calibrate the model, we find that the predictions of the model are consistent with actual data on growth. In chapter 3, we study the relationship between financial integration and economic volatility. Prior research that has studied this relationship has not explored the potentially distinct effects of capital inflows and capital out flows on volatility. Our contribution is to make this crucial distinction conducting our analysis. We find that non-OECD countries with higher levels of external debt assets are associated with lower consumption volatility, and external debt liabilities are associated with higher consumption volatility. This finding is insignificant for OECD countries

Association between Sex Hormone and Blood Uric Acid in Male Patients with Type 2 Diabetes

The association between serum uric acid (SUA) level and sexual dysfunction in patients with diabetes is not well characterized. Type 2 diabetes mellitus (T2DM) causes metabolic disorders, including abnormal serum uric acid (SUA) levels. In this study, we enrolled 205 male patients with T2DM and investigated the relationship between sex hormone levels and SUA. Patients were divided into four groups based on SUA quartiles. On the other hand, based on the total testosterone (TT) level, patients were divided into three groups; SUA and other laboratory indices were determined. Increase in SUA level was significantly associated with decreased levels of TT, luteinizing hormone, follicle-stimulating hormone, sex hormone-binding globulin, and increased levels of dehydroepiandrosterone, age, body mass index (BMI), waist circumference, glycated hemoglobin, serum creatinine, and HOMA-IR levels. SUA, waist circumference, BMI, and HOMA-IR showed a negative correlation with TT level, while age showed a positive correlation with TT level. SUA and body mass index were found to be risk factors for gonadal dysfunction. Therefore, we conclude that hypogonadism of male patients with T2DM is related to SUA level

Characteristics and risk factors for invasive fungal infection in hospitalized patients with acute-on-chronic hepatitis B liver failure: a retrospective cohort study from 2010 to 2023

Background and aimThe global burden of invasive fungal infections (IFIs) is emerging in immunologic deficiency status from various disease. Patients with acute-on-chronic hepatitis B liver failure (ACHBLF) are prone to IFI and their conditions are commonly exacerbated by IFI. However, little is known about the characteristics and risk factors for IFI in hospitalized ACHBLF patients.MethodsA total of 243 hospitalized ACHBLF patients were retrospectively enrolled from January 2010 to July 2023. We performed restricted cubic spline analysis to determine the non-linear associations between independent variables and IFI. The risk factors for IFI were identified using logistic regression and the extreme gradient boosting (XGBoost) algorithm. The effect values of the risk factors were determined by the SHapley Additive exPlanations (SHAP) method.ResultsThere were 24 ACHBLF patients (9.84%) who developed IFI on average 17.5 (13.50, 23.00) days after admission. The serum creatinine level showed a non-linear association with the possibility of IFI. Multiple logistic regression revealed that length of hospitalization (OR = 1.05, 95% CI: 1.02–1.08, P = 0.002) and neutrophilic granulocyte percentage (OR = 1.04, 95% CI: 1.00–1.09, P = 0.042) were independent risk factors for IFI. The XGBoost algorithm showed that the use of antibiotics (SHAP value = 0.446), length of hospitalization (SHAP value = 0.406) and log (qHBV DNA) (SHAP value = 0.206) were the top three independent risk factors for IFI. Furthermore, interaction analysis revealed no multiplicative effects between the use of antibiotics and the use of glucocorticoids (P = 0.990).ConclusionIFI is a rare complication that leads to high mortality in hospitalized ACHBLF patients, and a high neutrophilic granulocyte percentage and length of hospitalization are independent risk factors for the occurrence of IFI

Inhibition of UGT1A1 by natural and synthetic flavonoids

Flavonoids are widely distributed phytochemicals in vegetables, fruits and medicinal plants. Recent studies demonstrate that some natural flavonoids are potent inhibitors of the human UDP-glucuronosyltransferase 1A1 (UGT1A1), a key enzyme in detoxification of endogenous harmful compounds such as bilirubin. In this study, the inhibitory effects of 56 natural and synthetic flavonoids on UGT1A1 were assayed, while the structure–inhibition relationships of flavonoids as UGT1A1 inhibitors were investigated. The results demonstrated that the C-3 and C-7 hydroxyl groups on the flavone skeleton would enhance UGT1A1 inhibition, while flavonoid glycosides displayed weaker inhibitory effects than their corresponding aglycones. Further investigation on inhibition kinetics of two strong flavonoid-type UGT1A1 inhibitors, acacetin and kaempferol, yielded interesting results. Both flavonoids were competitive inhibitors against UGT1A1-mediated NHPN-O-glucuronidation, but were mixed and competitive inhibitors toward UGT1A1-mediated NCHN-O-glucuronidation, respectively. Furthermore, docking simulations showed that the binding areas of NHPN, kaempferol and acacetin on UGT1A1 were highly overlapping, and convergence with the binding area of bilirubin within UGT1A1. In summary, detailed structure-inhibition relationships of flavonoids as UGT1A1 inhibitors were investigated carefully and the findings shed new light on the interactions between flavonoids and UGT1A1, and will contribute considerably to the development of flavonoid-type drugs without strong UGT1A1 inhibition.Peer reviewe

The burden of cardiovascular disease in Asia from 2025 to 2050: a forecast analysis for East Asia, South Asia, South-East Asia, Central Asia, and high-income Asia Pacific regions.

Summary Background Given the rapidly growing burden of cardiovascular disease (CVD) in Asia, this study forecasts the CVD burden and associated risk factors in Asia from 2025 to 2050. Methods Data from the Global Burden of Disease 2019 study was used to construct regression models predicting prevalence, mortality, and disability-adjusted life years (DALYs) attributed to CVD and risk factors in Asia in the coming decades. Findings Between 2025 and 2050, crude cardiovascular mortality is expected to rise 91.2% despite a 23.0% decrease in the age-standardised cardiovascular mortality rate (ASMR). Ischaemic heart disease (115 deaths per 100,000 population) and stroke (63 deaths per 100,000 population) will remain leading drivers of ASMR in 2050. Central Asia will have the highest ASMR (676 deaths per 100,000 population), more than three-fold that of Asia overall (186 deaths per 100,000 population), while high-income Asia sub-regions will incur an ASMR of 22 deaths per 100,000 in 2050. High systolic blood pressure will contribute the highest ASMR throughout Asia (105 deaths per 100,000 population), except in Central Asia where high fasting plasma glucose will dominate (546 deaths per 100,000 population). Interpretation This forecast forewarns an almost doubling in crude cardiovascular mortality by 2050 in Asia, with marked heterogeneity across sub-regions. Atherosclerotic diseases will continue to dominate, while high systolic blood pressure will be the leading risk factor. Funding This was supported by the NUHS Seed Fund (NUHSRO/2022/058/RO5+6/Seed-Mar/03), National Medical Research Council Research Training Fellowship (MH 095:003/008-303), National University of Singapore Yong Loo Lin School of Medicine's Junior Academic Fellowship Scheme, NUHS Clinician Scientist Program (NCSP2.0/2024/NUHS/NCWS) and the CArdiovascular DiseasE National Collaborative Enterprise (CADENCE) National Clinical Translational Program (MOH-001277-01)

Antifungal susceptibility profiles and drug resistance mechanisms of clinical Candida duobushaemulonii isolates from China

Candida duobushaemulonii, type II Candida haemulonii complex, is closely related to Candida auris and capable of causing invasive and non-invasive infections in humans. Eleven strains of C. duobushaemulonii were collected from China Hospital Invasive Fungal Surveillance Net (CHIF-NET) and identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF), VITEK 2 Yeast Identification Card (YST), and internal transcribed spacer (ITS) sequencing. Whole genome sequencing of C. duobushaemulonii was done to determine their genotypes. Furthermore, C. duobushaemulonii strains were tested by Sensititre YeastOne™ and Clinical and Laboratory Institute (CLSI) broth microdilution panel for antifungal susceptibility. Three C. duobushaemulonii could not be identified by VITEK 2. All 11 isolates had high minimum inhibitory concentrations (MICs) to amphotericin B more than 2 μg/ml. One isolate showed a high MIC value of ≥64 μg/ml to 5-flucytosine. All isolates were wild type (WT) for triazoles and echinocandins. FUR1 variation may result in C. duobushaemulonii with high MIC to 5-flucytosine. Candida duobushaemulonii mainly infects patients with weakened immunity, and the amphotericin B resistance of these isolates might represent a challenge to clinical treatment

Implementation and performances of the IPbus protocol for the JUNO Large-PMT readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a large neutrino detector currently under construction in China. Thanks to the tight requirements on its optical and radio-purity properties, it will be able to perform leading measurements detecting terrestrial and astrophysical neutrinos in a wide energy range from tens of keV to hundreds of MeV. A key requirement for the success of the experiment is an unprecedented 3% energy resolution, guaranteed by its large active mass (20 kton) and the use of more than 20,000 20-inch photo-multiplier tubes (PMTs) acquired by high-speed, high-resolution sampling electronics located very close to the PMTs. As the Front-End and Read-Out electronics is expected to continuously run underwater for 30 years, a reliable readout acquisition system capable of handling the timestamped data stream coming from the Large-PMTs and permitting to simultaneously monitor and operate remotely the inaccessible electronics had to be developed. In this contribution, the firmware and hardware implementation of the IPbus based readout protocol will be presented, together with the performances measured on final modules during the mass production of the electronics

Mass testing of the JUNO experiment 20-inch PMTs readout electronics

The Jiangmen Underground Neutrino Observatory (JUNO) is a multi-purpose, large size, liquid scintillator experiment under construction in China. JUNO will perform leading measurements detecting neutrinos from different sources (reactor, terrestrial and astrophysical neutrinos) covering a wide energy range (from 200 keV to several GeV). This paper focuses on the design and development of a test protocol for the 20-inch PMT underwater readout electronics, performed in parallel to the mass production line. In a time period of about ten months, a total number of 6950 electronic boards were tested with an acceptance yield of 99.1%