Precise Regulation of Combustion Characteristics of High-Energy Composite Propellants by Incorporation of CL-20 Crystals Intercalated with Energetic Burn Rate Modifiers.

In this study, a 2D structured triaminoguanidine-glyoxal polymer with a high nitrogen content has been coordinated with metal ions to produce energetic metal complexes (TAGP-Ms) employed as energetic burn rate inhibitors. The metal ions (Ba2+, K+, and Ca2+) are elaborately selected based on their ability of suppressing the burn rate of composite propellants. The CL-20 crystals were intercalated with prepared TAGP-Ms materials via a solvent-antisolvent method for realization of the precise control on burning behaviors of studied propellants. The influence of TAGP-Ms inhibitors on thermal decomposition and combustion characteristics of high-energy composite propellants was evaluated using thermal analysis and a combustion diagnostic method. Results of TGA/DSC-FTIR measurements suggest that the thermal decomposition of CL-20-containing composite propellants was found to be constrained by varied degrees as a result of TAGP-Ms additions, in which the TAGP-K displays a stronger effect on suppressing the thermal decomposition of CL-20 compared with that of other TAGP-Ms. The FTIR spectra indicate that the primary gaseous phase products are composed of N2O, H2O, and CO2 in CL-20 decomposition, as well as by HCl, H2O, NO2, and N2O in the decomposition of AP for all studied composite propellants. The combustion characterizations show that the TAGP-K-containing composite propellant exhibits a significantly reduced rate of heat release but is associated with a higher flame radiation intensity increased by 4.2% compared with that of the reference propellant, which clearly implies that the TAGP-K is capable of suppressing the energy release rate while ensuring the high energetic features of propellants to be well maintained. Moreover, the burn rate pressure exponents are considerably decreased by ∼10% for the TAGP-K-containing propellants in comparison with those of propellants with the typical formulation, which strongly suggests that TGAP-Ms are promising candidates for tuning the combustion behaviors of composite propellants by influencing the decomposition processes of CL-20 and AP collectively.

Stabilization of AlH3 Crystals by the Coating of Hydrophobic PFPE and Resulted Reactivity with Ammonium Perchlorate.

Aluminum hydride (AlH3) is a promising fuel component of solid propellant, but its stabilization is still challenging. Herein, surface functionalization of hydrophobic perfluoropolyether (PFPE) followed by ammonium perchlorate (AP) coating has been implemented. In particular, AlH3@PFPE@xAP (x = 10, 30, 50, or 64.21%) composites (AHFPs) were prepared by a spray-drying technique. The PFPE-functionalized AlH3 with a hydrophobic surface shows an increased water contact angle (WCA) from 51.87° to 113.54°. Compared with pure AlH3, the initial decomposition temperatures of AHFPs were increased by 17 °C, and the decomposition properties of AP in the AHFPs were also enhanced with significantly decreased peak temperature and fairly increased energy output. Moreover, the decomposition induction time of AHFPs-30% was improved by almost 1.82 times that of raw AlH3, which indicates that the coatings of PFPE and AP could improve the stability of AlH3. The maximum flame radiation intensity of AHFPs-30% was 21.6 × 103, which is almost 7.71 times that of pure AlH3 (2.8 × 103).

Time from last immunity event against infection during Omicron-dominant period in Malaysia.

OBJECTIVES: To study the incidence of Omicron infections in Malaysia and the exposures that could reduce the hazard of attaining Omicron infection. METHODS: We used a multicenter, prospective cohort to study 482 healthcare workers vaccinated with two and three doses of BNT162b2 for SARS-CoV-2 infection during the Omicron-dominant period in Malaysia. RESULTS: Between January 31 and July 31, 2022, the cumulative incidence was 44.6% (95% CI 40.2-49.1%), and the incidence rate was 3.33 (95% CI 2.91-3.80) per 1000 person-days. Our study found that protection against Omicron infection was significantly higher for persons with previous SARS-CoV-2 infection (hazard ratio [HR] 0.41, 95% CI 0.27-0.62) and persons with a more recent immunity event (<30 days [reference] vs >90 days, HR 3.82, 95%CI 1.34-10.90) from the beginning of the Omicron period. CONCLUSION: Pre-Omicron natural infection and a recent immunity event protect against future Omicron infections.

Projecting the impact of implementation of WHO MPOWER measures on smoking prevalence and mortality in Japan.

OBJECTIVE: This study aimed to quantify the long-term impact of implementing the WHO Framework Convention on Tobacco Control (FCTC) compliant tobacco control measures, MPOWER, on smoking prevalence and mortality in men and women aged ≥20 years in Japan. DESIGN: A Stock-and-Flow simulation model was used to project smoking prevalence and mortality from 2018 to 2050 under eight different scenarios: (1) maintaining the 2018 status quo, (2) implementation of smoke-free policies, (3) tobacco use cessation programmes, (4-5) health warning about the dangers of tobacco (labels, mass media), (6) enforcement of tobacco advertising bans or (7) tobacco taxation at the highest recommended level and (8) all these interventions combined. RESULTS: Under the status quo, the smoking prevalence in Japan will decrease from 29.6% to 15.5% in men and 8.3% to 4.7% in women by 2050. Full implementation of MPOWER will accelerate this trend, dropping the prevalence to 10.6% in men and 3.2% in women, and save nearly a quarter million deaths by 2050. This reduction implies that Japan will only attain the current national target of 12% overall smoking prevalence in 2033, 8 years earlier than it would with the status quo (in 2041), a significant delay from the national government's 2022 deadline. CONCLUSIONS: To bring forward the elimination of tobacco smoking and substantially reduce smoking-related deaths, the government of Japan should fulfil its commitment to the FCTC and adopt stringent tobacco control measures delineated by MPOWER and beyond.

COVID-19 breakthrough infections and humoral immune response among BNT162b2 vaccinated healthcare workers in Malaysia.

The evaluation of breakthrough infection and humoral immunity responses are important outcomes for vaccination policy for healthcare staff. This prospective cohort study collected blood samples at 5-time points; before primary vaccine doses, and at 2, 10 and 24 weeks after BNT162b2 vaccination from 551 HCWs, between March and October 2021. We investigated the association between anti-spike-1 protein receptor-binding domain (anti-S1-RBD) antibody geometric mean titre (GMT) and breakthrough infections. Two weeks post-vaccination, the GMT of anti-S1-RBD antibodies was measured at almost maximum detectable value (3115 BAU/ml [95% CI, 3051-3180]); it decreased to 1486 BAU/ml (95% CI, 1371-1610) at 10 weeks; and to 315 BAU/ml (95% CI, 283-349) at 24 weeks. Prior COVID-19 infection and age significantly affected the antibody titres. Fifty-six participants, none of whom were COVID-19 convalescents, had breakthrough infections between 10 and 24 weeks post-vaccination. Before breakthrough infections, the GMT was not different between the breakthrough and non-breakthrough individuals. After infection, the GMT was significantly higher in individuals with breakthrough infections (2038 BAU/ml [95%CI, 1547-2685]), specifically in symptomatic breakthroughs, compared to those without infection (254 BAU/ml [95%CI, 233-278]). A notable surge in breakthrough infections among healthcare workers coincided with the emergence of the Delta variant and when BNT162b2-elicited antibody responses waned in 10-24 weeks (i.e. approximately 3-6 months). Post-breakthrough, the antibody response was boosted in individuals with symptomatic presentations, but not asymptomatic individuals. The study finding supports administering booster vaccination for healthcare staff, including those who recovered from asymptomatic breakthrough infection.

Adult palliative care 2004-2030 population study: estimates and projections in Malaysia.

OBJECTIVES: To estimate past trends and future projection of adult palliative care needs in Malaysia. METHODS: This is a population-based secondary data analysis using the national mortality registry from 2004 to 2014. Past trend estimation was conducted using Murtagh's minimum and maximum methods and Gómez-Batiste's method. The estimated palliative care needs were stratified by age groups, gender and administrative states in Malaysia. With this, the projection of palliative care needs up to 2030 was conducted under the assumption that annual change remains constant. RESULTS: The palliative care needs in Malaysia followed an apparent upward trend over the years regardless of the estimation methods. Murtagh's minimum estimation method showed that palliative care needs grew 40% from 71 675 cases in 2004 to 100 034 cases in 2014. The proportion of palliative care needs in relation to deaths hovered at 71% in the observed years. In 2030, Malaysia should anticipate the population needs to be at least 239 713 cases (240% growth from 2014), with the highest needs among age group ≥80-year-old in both genders. Sarawak, Perak, Johor, Selangor and Kedah will become the top five Malaysian states with the highest number of needs in 2030. CONCLUSION: The need for palliative care in Malaysia will continue to rise and surpass its service provision. This trend demands a stepped-up provision from the national health system with advanced integration of palliative care services to narrow the gap between needs and supply.

Incidence and Determinants of Acute Mountain Sickness in Mount Kinabalu, Malaysia.

Background: Acute mountain sickness (AMS) is the most common type of high-altitude sickness. The incidence of AMS varies by mountain location, trail characteristics, and study design. The lack of local epidemiology data has driven us to investigate the incidence and severity of AMS and its associated factors at Mount Kinabalu, Malaysia. Methods: A cohort study was conducted to collect data from climbers after days 1 (3272 m) and 2 (4095 m) of ascent. A self-administered questionnaire was used to explore climbers' demographic and climb characteristics, history of AMS, alcohol exposure, and AMS prevention measures. The Lake Louis score 2018 was used to assess the presence and severity of AMS (cutoff ≥3). Univariate and multivariable logistic regressions were performed to determine the factors associated with the development of AMS on day 2. Results: Data from 345 climbers were analyzed. The incidence of AMS was 23.9% (95% confidence interval [CI] 19.5%-28.7%) and 21.7% (95% CI 17.5%-26.3%) on days 1 and 2, respectively. The majority were mild cases. Experiencing AMS on day 1 (odds ratio [OR] = 12.88; 95% CI 6.71-24.75), alcohol consumption (OR = 3.73; 95% CI 1.66-8.39), receiving guide advice on day 1 (OR = 0.49; 95% CI 0.26-0.93), and age (OR = 0.96; 95% CI 0.93-0.99) were significant determinants of AMS at Mount Kinabalu. Gender, history of AMS, past exposure to high altitude, ascending time, water intake, acetazolamide use, physical fitness, pulse rate, and peripheral capillary oxygen saturation (SpO2) were not associated with AMS at Mount Kinabalu. Conclusion: Future analysis with age strata is required to ascertain the association of age with AMS. Our research has signposted a strong call for collaborative efforts to improve the provision of hiking advice and discourage alcohol sales to mitigate the risk of AMS among Mount Kinabalu climbers.

Treating More with Less: Effectiveness and Event Outcomes of Antituberculosis Fixed-dose Combination Drug versus Separate-drug Formulation (Ethambutol, Isoniazid, Rifampicin and Pyrazinamide) for Pulmonary Tuberculosis Patients in Real-world Clinical Practice.

INTRODUCTION: Conventionally, a combination of four separate drugs (ethambutol, isoniazid, rifampicin, and pyrazinamide [EHRZ]) is the first-line pharmacotherapy for pulmonary tuberculosis (TB). In recent years, fixed-dose combination (FDC) formulation, where a single tablet contains the active ingredients of four aforementioned drugs, is gaining popularity due to its ease of administration. OBJECTIVE: To compare the real-world effectiveness of EHRZ and FDC treatment groups on a cohort registry by investigating the sputum conversion rate and treatment outcomes of both groups. METHODS: A total of 11,489 patients' data were extracted from the Sabah TB registry between January 2012 and June 2016, including EHRZ (n = 4188) and FDC (n = 7301) patients. Then, 1:1 propensity score matching was adopted to reduce the baseline bias. Caliper matching was conducted with maximum tolerance score set at 0.001. Confounders included in the propensity score matching were gender, nationality, diabetes, HIV status, smoking status, and chest X-ray status. Successful matching provided 4188 matched pairs (n = 8376) for final analysis. RESULTS: In this matched cohort of 4188 pairs, the 2-month sputum conversion rate of FDC group was significantly higher than the EHRZ group (96.3% vs. 94.3%; P < 0.001) whereas 6-month sputum conversion of both groups showed no significant difference. Treatment outcomes such as noncompliance rate, failure rate, and success rate have no significant difference (P > 0.05) in both the treatment groups. There was an incidental finding of reduced death rate among FDC group compared to the EHRZ group (0.2% vs. 0.5%; P = 0.034). CONCLUSION: The FDC formulation has better sputum conversion rate at 2 months compared to conventional EHRZ regime as separate-drug formulation. It was also observed that FDC has a slight protective effect against all-cause death among TB patients. This protective effect of FDC, however, still needs to be proven further.