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BackgroundTo respond to the dual HIV and injecting drug use epidemic, Vietnam has implemented methadone maintenance treatment (MMT) nationwide since 2010 and decentralized it to primary care (i.e. commune health centers) since 2015. The study aims to explore the challenges that Vietnamese community health workers (CHW) at commune health centers encounter in providing MMT and the factors associated to these challenges.MethodsThis study had a mixed method design. We used two types of data in this study. For the sub-study 1, we used the secondary data from a quantitative survey conducted in Vinh Phuc and Phu Tho provinces among 300 CHWs who did not provide MMT at the time of the study. For the sub-studies 2 and 3, we collected quantitative and qualitative primary data from Dien Bien province. We conducted a quantitative survey among 276 CHWs including both MMT providers and non-MMT providers. From this sample, we selected 26 MMT providers with various characteristics for in-depth interviews.ResultsIn the sub-study 1, the mean score of CHWs’ interaction with PWUD 36.4 (SD 8.8) on a scale of 60. The interaction between CHW not providing MMT and people who use drugs (PWUD) was negatively associated with their stigmatizing attitude towards PWUD (β = -0.84, 95% CL: -1.05; -0.63) after adjusting for their background (gender, education level, job position and years of working experience) and job-related characteristics (perceived risk and challenges when working with PWUD, job satisfaction and empathy towards PWUD). In the sub-study 2, 114 (41.3%) CHW had ever provided MMT services. Better MMT knowledge was associated with higher levels of confidence in providing MMT services among CHW who had no experience with MMT program (β=0.90, 95%CL: 0.29; 1.51), not among those who had experiences. On the other hand, technical support in working with PWUD was associated with a higher level of confidence in providing MMT services for both groups (β=0.71, 95%CL: 0.35; 1.08 and β=0.58, 95%CL: 0.19; 0.96 among CHWs who had ever and who had never worked in MMT, respectively). In sub-study 3, the perceived challenges for MMT provision included lack of confidence and motivation to provide MMT, inadequate human resource, lack of institutional support, insufficient technical support, lack of referral resources and additional support for patients, lack of policies to support the MMT program at CHCs and to protect service providers.ConclusionCHWs in Vietnam faced several challenges in working with PWUD and providing MMT services at primary care settings. Supportive policies and tailored interventions should be developed at different levels to ensure the quality and effectiveness of the MMT decentralization program.

Background: Cervical cancer is one of the most common causes of cancer death in women in low- and middle-income countries (LMICs). The death of a woman also has an impact on her family and society. Taking Vietnam as an example, this thesis aims to quantify the burden of cervical cancer, to understand the impact of a mother’s death on childhood mortality, and to evaluate the impact of cervical cancer prevention strategies on health outcomes, harms, cost-effectiveness and budget impact. Methods: The burden of human papillomavirus (HPV) infection, precancer and cervical cancer in Vietnam was reviewed and synthesized, a systematic review and meta-analysis on the impact of maternal death on childhood mortality in LMICs was conducted, and the number of female deaths from cancers and additional child deaths were predicted for 2015 in Vietnam. A comprehensive modelled evaluation of the health outcomes, number needed to treat, cost-effectiveness and budget impact of several HPV vaccination and cervical screening options in Vietnam was conducted. Results: Without intervention, the number of new cervical cancer cases in Vietnam will increase from 6,707 (range 5,273-8,493) in 2012 to 7,958 (4,919-12,762) in 2049. The relative risk of child death among children whose mother died vs. those whose mother is alive ranged from 2.8-35.5, depending on age of child and time since a maternal death. There were ~200,000 deaths from any cause in women aged 15-59 years and an estimated 4,000 associated childhood deaths in 2015 in Vietnam. All available HPV vaccine types would be very cost-effective at US$4.5-$14.4 per dose. Twice-lifetime cervical screening with HPV testing, triaging with HPV genotyping in urban regions and visual inspection in rural regions, would be very cost-effective and could reduce cervical cancer mortality by up to 30%. For younger vaccinated cohorts, screening would remain cost-effective. Conclusions: HPV vaccination and cervical screening are effective and cost-effective cervical cancer prevention strategies in Vietnam; the benefits of such cancer prevention strategies will not only accrue to women but also to their children. These findings have implications not only for Vietnam but for other LMICs that have not yet implemented concerted cervical cancer prevention programs.

CO has been recognised as a signalling molecule in mammalian organisms and is involved in regulating physiological and pathophysiological pathways. CO has also been demonstrated to have potent anti-inflammatory, anti-proliferative and anti-apoptotic effects. The significant therapeutic effects of controlled CO inhalation have been proven in animal models of disease with the anti-inflammatory activity of CO studied in phase II clinical trials. However, the therapeutic benefits of CO gas administration have remained questionable as a result of its systemic toxicity at high concentrations and difficulties in storing and delivering gaseous CO to the target tissue in a controlled manner. To overcome these limitations, chemists have developed molecules capable of releasing carbon monoxide (CORMs) as pharmaceutical agents for safer, more convenient and controlled CO release. Among CORMs, the commercial CORM-2 and CORM-3 are the most common CO releasing molecules used in biological studies. These compounds exert significant biological properties including anti-inflammatory and antimicrobial activities. However, the clinical use of these compounds as therapeutic agents is problematic owing to their short CO-releasing half-life and poor solubility in aqueous solutions. These drawbacks can be addressed by using macromolecular scaffolds as CO carriers. Macromolecular carriers, such as polymeric nanoparticles appear to be an ideal vehicle for the transport of drugs because their sizes can be easily tuned, permitting passive accumulation in tumour tissue via the enhanced permeability and retention (EPR) effect. Additionally, macromolecular carriers offer a high CO-loading capacity due to the attachment of several CO per macromolecule, resulting in a significant increase in the CO concentration. Furthermore, nanocarriers not only enhance the therapeutic efficacy, but they also reduce the systemic toxicity of drugs, which results in a reduction in side effects. Inspired both by the excellent biological activities of CORM-2/CORM-3 and many advantages of macromolecular materials, we aimed to construct novel multifunctional macromolecular systems that possess features allowing the controlled and selective delivery of CO. This work opens up new strategies for development of CO releasing scaffolds in biological applications.

Thermoelectric (TE) materials have been attractive to several research groups all over the world for their ability of directly converting thermal energy into electrical energy by the Seebeck Effect, and vice versa by the Peltier Effect. Due to their reliability and scalability, TE materials can be incorporated into devices for power generation or for cooling applications. Skutterudites have a complex crystalline structure in which the voids in the structure can be filled with foreign atoms. This doping technique has been shown to improve the TE performance of these "filled" skutterudite materials by disrupting the thermal conductivity without significantly impacting the electrical conductivity. Several studies have been done on filled CoSb3-based skutterudites and high ZT values have been obtained for these materials around 6000C. However, for thermoelectric applications that require higher operating temperatures, the more refractory IrSb3 with a peritectic decomposition at 11360C (1409 K) offers an advantage over CoSb3, which decomposes at 8740C (1147 K). Using the traditional synthesis method of melting, quenching, then annealing stoichiometric amounts of the elements to produce n-filled skutterudites, the obtained filling fraction was found to be significantly lower than the nominal filling fraction due to the high reactivity, or sometimes the high volatility, of the elemental fillers. In this experiment, we explored the effects of pre-reacting the reactive metal filler element with one of the elements in the skutterudite structure and utilized this precursor for the synthesis of the filled skutterudites to compare the relative successes of achieving targeted filling percentages of the voids in the structure. KyIr4Sb12 samples were synthesized using both the pure filler element, as well as the pre-reacted K-Sb compound. The phase purities, lattice parameters and elemental compositions were analyzed for each sample, calculated using X-Ray diffraction (XRD), scanning electron microscopy (SEM) and electron microprobe analysis (EPMA), respectively. Their thermoelectric properties were also measured and calculated at room temperature and as a function of temperature ranging from room temperature to about 7500C (1023 K). The preliminary results obtained suggest that pre-reacting the potassium with antimony results in higher percentages of phase impurities and less efficient void filling in IrSb3 skutterudite. The highest ZT among all potassium-filled samples synthesized was measured to be 0.28 at 5000C (773 K) for K0.24Ir4Sb12. The data suggest that the cumulative thermoelectric properties of potassium filled IrSb3 are not as favorable as those IrSb3-based skutterudites filled with other atoms such as Ba or Eu. However, some of the potassium-filled samples achieved high room temperature carrier concentrations, similar to those seen in barium-filled samples, indicating that the potassium effectively participates in doping the structure. This work has compared and contrasted two methods for incorporating potassium fillers in the void spaces of IrSb3 skutterudite. While the ZT of potassium-filled samples was less than required for practical applications, this work does suggest that potassium may be useful in tuning electrical properties in samples that employ multiple element filling. The relationship between the lattice parameter and the filling fraction was also studied on barium-filled and europium-filled IrSb3 skutterudite samples. A higher nominal filling fraction acquired a higher EPMA filling fraction and a higher lattice parameter until the filling fraction limit was reached. While barium displayed higher filling efficiency, europium possessed higher filling fraction limit. These preliminary results suggest that the optimization of multiple element filling to produce higher ZT is very obtainable with further studies on different single fillers.