Real-world experience of metformin 1000 mg/day in patients with type 2 diabetes mellitus and comorbidities from Myanmar

Background: The study was conducted to assess the efficacy and safety of 1000 (mg/day) metformin in patients with type 2 diabetes (T2DM) with comorbidities and special reference to elderly people in Myanmar.Methods: This was a retrospective, post surveillance study conducted in patients diagnosed with T2DM receiving treatment of metformin (1000 mg/day). Baseline characteristics, comorbidities, random blood sugar level (RBS) and RBS changes pre- and post-therapy were retrieved from patient’s medical records. A paired sample t-test was used for comparing the pre- and post-treatment RBS levels.Results: A total of 303 patients with T2DM were included. A total of 88, 115 and 100 patients belonged to age groups ≤50, >50-≤60 and >61 years, respectively. Duration of T2DM was significantly higher in elderly patients (>61 years) compared to ≤50 and >50-≤60 age group. Hypertension was the most common comorbid condition observed in all age groups followed by cardiovascular disease. However, both hypertension and cardiovascular disease were significantly higher among elderly patients (>61 years) compared to ≤50 and >50-≤60 age group (p50-≤60 years, 86.2 mg/dL and >61 years, 97.2 mg/dL). Metformin was well tolerated with minimal gastrointestinal adverse events (n=27).Conclusions: In this post marketing surveillance study, metformin (1000 mg/day) was found to be effective in reducing RBS in T2DM patients with comorbidities especially older adults and well tolerated with no risk of hypoglycemia

Prevalence and Risk Factors of Eye Problems among Older People in Central Tropical Region, Naypyitaw Union Territory, Myanmar

Purpose:Vision is essential one and it is proximately linked with their quality of life. In the meantime, older populations are increasing rapidly in the whole world and thus, age-related macular degeneration, glaucoma, cataract and diabetic retinopathy are becoming common. Hot and dusty environment, inadequate access to water and poor facial hygiene are risk factors for blindness. Design: Lewe Township was purposively selected due to its high prevalent on eye problems. This cross-sectional study was conducted and simple random sampling was applied to achieve desired sample size. The structured questionnaires were used to collect data including screening of eye problems from 414 older population. Frequency, percentage, mean, SD and other descriptive analysis were determined and chi-square test for associations was constructed. Findings: Cataract was the highest prevalence rate with 40.8% followed by refractive error (27.3%) and pterygium (12.8%) among older people population in research area. While knowledge level indicated good level (88.4%), good attitude level (21.3%) and good practice level (27.1%) were noticeably low among older people. In the meantime, there were significantly associations between age (p=0.003) and education level (p=0.001) with knowledge level of older people while age (p=0.001), education level (p=<0.001), occupation (p=0.038) showed statistically association with attitude level. Originality:The study noticed that higher prevalence of eye problems while relatively poor level of eye care seeking practice and unawareness on risk factors in targeted community. Knowledge and awareness for changing attitude about eye problems, eye care seeking behavior and preventive practices should be accomplished more

Controlling Electronic States of Few-walled Carbon Nanotube Yarn via Joule-annealing and p-type Doping Towards Large Thermoelectric Power Factor

Flexible, light-weight and robust thermoelectric (TE) materials have attracted much attention to convert waste heat from low-grade heat sources, such as human body, to electricity. Carbon nanotube (CNT) yarn is one of the potential TE materials owing to its narrow band-gap energy, high charge carrier mobility, and excellent mechanical property, which is conducive for flexible and wearable devices. Herein, we propose a way to improve the power factor of CNT yarns fabricated from few-walled carbon nanotubes (FWCNTs) by two-step method; Joule-annealing in the vacuum followed by doping with p-type dopants, 2,3,5,6-tetrafluo-7,7,8,8-tetracyanoquinodimethane (F4TCNQ). Numerical calculations and experimental results explain that Joule-annealing and doping modulate the electronic states (Fermi energy level) of FWCNTs, resulting in extremely large thermoelectric power factor of 2250 mu Wm(-1) K-2 at a measurement temperature of 423K. Joule-annealing removes amorphous carbon on the surface of the CNT yarn, which facilitates doping in the subsequent step, and leads to higher Seebeck coefficient due to the transformation from (semi) metallic to semiconductor behavior. Doping also significantly increases the electrical conductivity due to the effective charge transfers between CNT yarn and F4TCNQ upon the removal of amorphous carbon after Joule-annealing

Experimental and numerical analysis on the thermal performance of the aluminium absorber

The absorber is a vital part of a solar air collector and has a significant impact on the overall efficiency of a solar air heating unit. The objective of this research is to examine and compare the performance of two distinct aluminium absorbers with and without aluminium fins by using experimental and numerical (computational fluid dynamics – CFD) methods. The studies were conducted in Mandalay, Myanmar, which is located at latitude 21.98° N and longitude 96.1° E, during December 2022. A plate absorber solar air collector (PASAC) and finned absorber solar air collector (FASAC) with the same absorber area of 0.889 m2 are compared in terms of their thermal performance. At a mass flow rate of 0.0389 kg/s, the average thermal efficiency, as computed numerically, is 53.5 % for FASAC, and the experimental results show a thermal efficiency of 54.2 %. Similarly, for PASAC, the numerical computation yields an average thermal efficiency of 44.4 %, while the experimental results indicate a thermal efficiency of 47.3 %. The FASAC outperforms PASAC in terms of thermal performance. The improved thermal performance of the double-pass solar air collectors with aluminium-finned absorbers can be advantageous for employment as a drying process unit

High rate of virological failure and low rate of switching to second-line treatment among adolescents and adults living with HIV on first-line ART in Myanmar, 2005-2015.

BACKGROUND: The number of people living with HIV on antiretroviral treatment (ART) in Myanmar has been increasing rapidly in recent years. This study aimed to estimate rates of virological failure on first-line ART and switching to second-line ART due to treatment failure at the Integrated HIV Care program (IHC). METHODS: Routinely collected data of all adolescent and adult patients living with HIV who were initiated on first-line ART at IHC between 2005 and 2015 were retrospectively analyzed. The cumulative hazard of virological failure on first-line ART and switching to second-line ART were estimated. Crude and adjusted hazard ratios were calculated using the Cox regression model to identify risk factors associated with the two outcomes. RESULTS: Of 23,248 adults and adolescents, 7,888 (34%) were tested for HIV viral load. The incidence rate of virological failure among those tested was 3.2 per 100 person-years follow-up and the rate of switching to second-line ART among all patients was 1.4 per 100 person-years follow-up. Factors associated with virological failure included: being adolescent; being lost to follow-up at least once; having WHO stage 3 and 4 at ART initiation; and having taken first-line ART elsewhere before coming to IHC. Of the 1032 patients who met virological failure criteria, 762 (74%) switched to second-line ART. CONCLUSIONS: We found high rates of virological failure among one third of patients in the cohort who were tested for viral load. Of those failing virologically on first-line ART, about one quarter were not switched to second-line ART. Routine viral load monitoring, especially for those identified as having a higher risk of treatment failure, should be considered in this setting to detect all patients failing on first-line ART. Strategies also need to be put in place to prevent treatment failure and to treat more of those patients who are actually failing

Long-term outcomes of second-line antiretroviral treatment in an adult and adolescent cohort in Myanmar.

BACKGROUND: Myanmar has a high burden of Human Immunodeficiency Virus (HIV) and second-line antiretroviral treatment (ART) has been available since 2008 in the public health sector. However, there have been no published data about the outcomes of such patients until now. OBJECTIVE: To assess the treatment and programmatic outcomes and factors associated with unfavorable outcomes (treatment failure, death and loss to follow-up from care) among people living with HIV (aged ≥ 10 years) receiving protease inhibitor-based second-line ART under the Integrated HIV Care Program in Myanmar between October 2008 and June 2015. DESIGN: Retrospective cohort study using routinely collected program data. RESULTS: Of 824 adults and adolescents on second-line ART, 52 patients received viral load testing and 19 patients were diagnosed with virological failure. However, their treatment was not modified. At the end of a total follow-up duration of 7 years, 88 (11%) patients died, 35 (4%) were lost to follow-up, 21 (2%) were transferred out to other health facilities and 680 (83%) were still under care. The incidence rate of unfavorable outcomes was 7.9 patients per 100 person years follow-up. Patients with a history of injecting drug use, with a history of lost to follow-up, with a higher baseline viral load and who had received didanosine and abacavir had a higher risk of unfavorable outcomes. Patients with higher baseline C4 counts, those having taken first-line ART at a private clinic, receiving ART at decentralized sites and taking zidovudine and lamivudine had a lower risk of unfavorable outcomes. CONCLUSIONS: Long-term outcomes of patients on second-line ART were relatively good in this cohort. Virological failure was relatively low, possibly because of lack of viral load testing. No patient who failed on second-line ART was switched to third-line treatment. The National HIV/AIDS Program should consider making routine viral load monitoring and third-line ART drugs available after a careful cost-benefit analysis

Observational study of adult respiratory infections in primary care clinics in Myanmar: understanding the burden of melioidosis, tuberculosis and other infections not covered by empirical treatment regimes.

BACKGROUND: Lower respiratory infections constitute a major disease burden worldwide. Treatment is usually empiric and targeted towards typical bacterial pathogens. Understanding the prevalence of pathogens not covered by empirical treatment is important to improve diagnostic and treatment algorithms. METHODS: A prospective observational study in peri-urban communities of Yangon, Myanmar was conducted between July 2018 and April 2019. Sputum specimens of 299 adults presenting with fever and productive cough were tested for Mycobacterium tuberculosis (microscopy and GeneXpert MTB/RIF [Mycobacterium tuberculosis/resistance to rifampicin]) and Burkholderia pseudomallei (Active Melioidosis Detect Lateral Flow Assay and culture). Nasopharyngeal swabs underwent respiratory virus (influenza A, B, respiratory syncytial virus) polymerase chain reaction testing. RESULTS: Among 299 patients, 32% (95% confidence interval [CI] 26 to 37) were diagnosed with tuberculosis (TB), including 9 rifampicin-resistant cases. TB patients presented with a longer duration of fever (median 14 d) and productive cough (median 30 d) than non-TB patients (median fever duration 6 d, cough 7 d). One case of melioidosis pneumonia was detected by rapid test and confirmed by culture. Respiratory viruses were detected in 16% (95% CI 12 to 21) of patients. CONCLUSIONS: TB was very common in this population, suggesting that microscopy and GeneXpert MTB/RIF on all sputum samples should be routinely included in diagnostic algorithms for fever and cough. Melioidosis was uncommon in this population

Design and fabrication of excitonic solar cells

The excitonic solar cells (XSCs), including organic solar cells (OSCs) and dye-sensitized solar cells (DSSCs), have attracted a great interest due to their huge potential of low cost technology compared to conventional silicon solar cells. Although the technologies of XSCs have advanced significantly, XSCs still need to be improved in various aspects to become tangible in energy market. The important criteria of a solar cell are efficiency, cost and life time. Hence, the research in this dissertation focuses on the design of XSCs with better choice of materials and device architecture for either enhancement in stability and efficiency or reduction of cost. In spite of over 7% power conversion efficiency, the OSC based on bulk-heterojunction concept has limitation in device stability due to diffusion of oxygen into the organic layer through pinholes and grain boundaries in Al cathode and the degradation of transparent conductive oxide (TCO) electrode, which is etched by poly (3,4-ethylene dioxythiophene):(polystyrene sulfonic acid) (PEDOT:PSS) buffer layer. To overcome this problem, an inverted structure was implemented. The reverse polarity of charge collection in an inverted structure allows the usage of air-stable high-work-function metal as top electrode and gets rid of TCO/PEDOT:PSS interface. In our design, TCO is modified with sol-gel derived zinc oxide (ZnO) to exclusively collect electrons from active layer and block holes. A thermal-evaporated molybdenum oxide (MoO3), which is inserted between active layer and top electrode, increases the fill factor of the device due to exciton/electron blocking property. It was observed that the efficiency of an inverted structure OSC can be further improved by manipulating the resistivity, energy level and optical property of ZnO layer with appropriate amount of indium doping. We also verified that the stability of device in air is significantly improved by inverted structure. DSSC, another type of XSC, is also a promising alternative to silicon photovoltaic technology. However, it is estimated that conducting glass is the most expensive part of DSSC and it incurs 60% of total cost. Therefore, we designed top-illuminated structure which can be fabricated on inexpensive opaque substrates such as metals or plastic foils with metal coating. Although the efficiency of the top-illuminated cell is about 20% lower than the traditional bottom-illuminated cell, it reduces the cost of DSSC tremendously by eliminating the usage of expensive TCO. Ti is more suitable to be used as electrode in top-illuminated DSSC than other metals because of minimum catalytic activity on redox reaction and high resistance to corrosion. Another approach to eliminate TCO is replacing with transparent carbon nanotube (CNT) electrode. However, the catalytic activity to redox reaction limits its application as working electrode in DSSC. Therefore, the implementation of DSSC with CNT electrode was realized by modifying CNT with titanium-sub-oxide (TiOx) which inhibits the charge-transfer kinetic at CNT/redox solution interface and facilitates the unidirectional flow of electrons in the cell. To our best knowledge, this is the first demonstration of CNT as working electrode for liquid-type DSSC. Based on this finding, we also realized DSSC with all carbon electrodes.DOCTOR OF PHILOSOPHY (EEE

Design and fabrication of excitonic solar cells.

The excitonic solar cells (XSCs), including organic solar cells (OSCs) and dyesensitized solar cells (DSSCs), have attracted a great interest due to their huge potential of low cost technology compared to conventional silicon solar cells. Although the technologies of XSCs have advanced significantly, XSCs still need to be improved in various aspects to become tangible in energy market. The important criteria of a solar cell are efficiency, cost and life time. Hence, the research in this dissertation focuses on the design of XSCs with better choice of materials and device architecture for either enhancement in stability and efficiency or reduction of cost. In spite of over 7% power conversion efficiency, the OSC based on bulkheterojunction concept has limitation in device stability due to diffusion of oxygen into the organic layer through pinholes and grain boundaries in Al cathode and the degradation of transparent conductive oxide (TCO) electrode, which is etched by poly (3,4-ethylene dioxythiophene):(polystyrene sulfonic acid) (PEDOT:PSS) buffer layer. To overcome this problem, an inverted structure was implemented. The reverse polarity of charge collection in an inverted structure allows the usage of air-stable high-work-function metal as top electrode and gets rid of TCO/PEDOT:PSS interface. In our design, TCO is modified with sol-gel derived zinc oxide (ZnO) to exclusively collect electrons from active layer and block holes. A thermal-evaporated molybdenum oxide (MoO3), which is inserted between active layer and top electrode, increases the fill factor of the device due to exciton/electron blocking property. It was observed that the efficiency of an inverted structure OSC can be further improved by manipulating the resistivity, energy level and optical property of ZnO ATTENTION: The Singapore Copyright Act applies to the use of this document. Nanyang Technological University Library viii layer with appropriate amount of indium doping. We also verified that the stability of device in air is significantly improved by inverted structure. DSSC, another type of XSC, is also a promising alternative to silicon photovoltaic technology. However, it is estimated that conducting glass is the most expensive part of DSSC and it incurs 60% of total cost. Therefore, we designed top-illuminated structure which can be fabricated on inexpensive opaque substrates such as metals or plastic foils with metal coating. Although the efficiency of the top-illuminated cell is about 20% lower than the traditional bottom-illuminated cell, it reduces the cost of DSSC tremendously by eliminating the usage of expensive TCO. Ti is more suitable to be used as electrode in top-illuminated DSSC than other metals because of minimum catalytic activity on redox reaction and high resistance to corrosion. Another approach to eliminate TCO is replacing with transparent carbon nanotube (CNT) electrode. However, the catalytic activity to redox reaction limits its application as working electrode in DSSC. Therefore, the implementation of DSSC with CNT electrode was realized by modifying CNT with titanium-sub-oxide (TiOx) which inhibits the charge-transfer kinetic at CNT/redox solution interface and facilitates the unidirectional flow of electrons in the cell. To our best knowledge, this is the first demonstration of CNT as working electrode for liquidtype DSSC. Based on this finding, we also realized DSSC with all carbon electrodes.DOCTOR OF PHILOSOPHY (EEE