A novel series of two zirconium- and one indium-based metal–organic frameworks (MOFs), namely, MOF-892, MOF-893, and MOF-894, constructed from the hexatopic linker, ...1′,2′,3′,4′,5′,6′-hexakis(4-carboxyphenyl)benzene, were synthesized and fully characterized. MOF-892 and MOF-893 are two new exemplars of materials with topologies previously unseen in the important family of zirconium MOFs. MOF-892, MOF-893, and MOF-894 exhibit efficient heterogeneous catalytic activity for the cycloaddition of CO2, resulting in a cyclic organic carbonate formation with high conversion, selectivity, and yield under mild conditions (1 atm CO2, 80 °C, and solvent-free). Because of the structural features provided by their building units, MOF-892 and MOF-893 are replete with accessible Lewis and Brønsted acid sites located at the metal clusters and the non-coordinating carboxylic groups of the linkers, respectively, which is found to promote the catalytic CO2 cycloaddition reaction. As a proof-of-concept, MOF-892 exhibits high catalytic activity in the one-pot synthesis of styrene carbonate from styrene and CO2 without preliminary synthesis and isolation of styrene oxide.
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IJS, KILJ, NUK, PNG, UL, UM
The chemical composition and larvicidal activity of essential oils from the leaves and rhizomes of Zingiber collinsii Mood & Theilade (Zingiberaceae) were reported. The main compounds in the leaf oil ...were α-pinene (25.6%), β-caryophyllene (16.8%), β-pinene (16.1%) and bicyclogermacrene (6.9%) while the rhizome oil consist mainly of camphene (22.5%), β-pinene (16.3%), α-pinene (9.0%) and humulene oxide II (9.0%). The rhizome oil demonstrated larvicidal effects towards fourth instant larvae of mosquito vectors. The highest mortality (100%) was observed at 24 h exposure against Aedes albopictus (concentration 100 μg/mL) and 48 h (concentration of 50 and 100 μg/mL), while the highest mortality (100%) was observed for Culex quinquefasciatus at 24 h and 48 h at concentration of 100 μg/mL. The 24 h mosquito larvicidal activity of the rhizome oil against Ae. albopictus were LC50 = 25.51 μg/mL; LC90 = 40.22 μg/mL and towards Cx. quinquefasciatus with LC50 = 50.11 μg/mL and LC90 = 71.53 μg/mL). However, the 48 h larvicidal activity were LC50 = 20.03 μg/mL and LC90 = 24.51 μg/mL (Ae. albopictus), as well as LC50 = 36.18 μg/mL and LC90 = 55.11 μg/mL (Cx. quinquefasciatus). On the other hand, no appreciable mortality and larvicidal activity was observed for the leaf oil. The larvicidal activity of the essential oils of Z. collinsii was being reported for the first time.
This work investigates the fate of polycyclic aromatic hydrocarbons (PAH) in relation to the process severity in the steam- and H2-containing reaction environment of steam gasification of biomass. ...The focus is on the regimen of tertiary tar formation during the gasification in a fluidized bed gasifier; the tertiary tar is tar that is predominantly aromatic compounds. The process severity reflects the following operating conditions: temperature, gas residence time in the reactor, and contact time between the gas phase and catalytic bed material. The conducted experiments employed a raw gas upgrading process downstream of the gasifier. A mature tar-containing raw gas produced in the Chalmers 2–4-MWth dual fluidized bed biomass gasifier was upgraded in a bench-scale, bubbling fluidized bed reactor, in which inert silica sand and a naturally occurring ilmenite catalyst were used as the bed materials. The obtained results show that, following the increased process severity, the growth of PAH can either enhance or suppress. For the growth of PAH being suppressed, it is required that the process severity is sufficient to convert steam and H2 into the reactive hydrogen intermediates that prevent the combination of the carbon-containing species. To ensure this, the application of silica sand as a bed material requires an operating temperature of 850 °C and a gas residence time of >11.5 s, while the use of ilmenite requires an operating temperature of 800 °C and a gas residence time of >3.4 s, together with a gas–solid contact time of about 0.7 s. In particular, the results obtained for ilmenite encourage the use of naturally occurring catalysts in fluidized bed gasifiers, despite the fact that their catalytic activities are lower than that of synthetic catalysts.
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IJS, KILJ, NUK, PNG, UL, UM
Although abiotic catalysts are capable of promoting numerous new-to-nature reactions, only a small subset has so far been successfully integrated into living systems. Research in intracellular ...catalysis requires an interdisciplinary approach that takes advantage of both chemical and biological tools as well as state of the art instruments. In this Perspective, we will focus on the techniques that have made studying metal-catalyzed reactions in cells possible using representative examples from the literature. Although the lack of quantitative data in vitro and in vivo has somewhat limited progress in the catalyst development process, recent advances in characterization methods should help overcome some of these deficiencies. Given its tremendous potential, we believe that intracellular catalysis will play a more prominent role in the development of future biotechnologies and therapeutics.
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IJS, KILJ, NUK, PNG, UL, UM
Summary
Azole‐resistant environmental Aspergillus fumigatus presents a threat to public health but the extent of this threat in Southeast Asia is poorly described. We conducted environmental ...surveillance in the Mekong Delta region of Vietnam, collecting air and ground samples across key land‐use types, and determined antifungal susceptibilities of Aspergillus section Fumigati (ASF) isolates and azole concentrations in soils. Of 119 ASF isolates, 55% were resistant (or non‐wild type) to itraconazole, 65% to posaconazole and 50% to voriconazole. Azole resistance was more frequent in A. fumigatus sensu stricto isolates (95%) than other ASF species (32%). Resistant isolates and agricultural azole residues were overrepresented in samples from cultivated land. cyp51A gene sequence analysis showed 38/56 resistant A. fumigatus sensu stricto isolates carried known resistance mutations, with TR34/L98H most frequent (34/38).
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Abstract
There are growing concerns on stress among nurses in low- and middle-income countries (LMICs) in South-East Asia. It is important to improve mental health among nurses in these countries. ...The objective of this study was to examine the efficacy of two types of newly developed smartphone-based stress management programs in improving depressive and anxiety symptoms among hospital nurses in Vietnam. This study was a three-arm (including two intervention groups and one control group) randomized trial. Participants were recruited from nurses in a large general hospital in Hanoi, Vietnam. Two types (free-choice and fixed sequential order) of smartphone-based stress management programs were developed. Participants were randomly allocated to Program A (a free-choice, multimodule stress management), Program B (a fixed-order, internet cognitive behavioral therapy, iCBT), or a control group (treatment as usual). The depressive and anxiety symptoms were measured by using the Depression Anxiety and Stress Scales at baseline, 3-, and 7-month follow-up surveys. 951 participants were randomly allocated to each of the three groups. Program B showed a statistically significant effect on improving depressive symptoms at 3-month (p = 0.048), but not at 7-month (p = 0.92); Cohen’s d was − 0.18 (95% CI − 0.34 to − 0.02) and 0.03 (95% CI − 1.00 to 1.05), respectively. Program A failed to show a significant intervention effect on any of the outcomes at 3- or 7-month follow-up (p > 0.05). Despite the small effect size, the present fixed-order iCBT program seems effective in improving depression of hospital nurses in Vietnam. A public health impact of the intervention can be scalable, when considering its accessibility and minimal cost.
Trial registration number: The study protocol is registered at the UMIN Clinical Trials Registry (UMINCTR; ID = UMIN000033139). Registered date of the protocol is 1st Jul. 2018.
https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000037796
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The present study investigated the internal consistency reliability, construct validity, and item response characteristics of a newly developed Vietnamese version of the Kessler 6 (K6) scale among ...hospital nurses in Hanoi, Vietnam. The K6 was translated into the Vietnamese language following a standard procedure. A survey was conducted of nurses in a large general hospital in Hanoi, Vietnam, using a questionnaire including the Vietnamese K6, other scales (DASS21, health-related QOL, self-rated health, and psychosocial work environment), and questions about demographic variables. Internal consistency reliability (Cronbach's alpha coefficient) was calculated. A confirmatory factor analysis was conducted. Eleven hypotheses were tested (as Pearson's correlations with the K6) to assess the scale's construct validity. Item response theory (IRT) analysis was conducted to identify the item response characteristics. The Cronbach's alpha coefficient was 0.864. The explanatory and confirmatory factor analyses indicated a one-factor structure. Most hypotheses tested for construct validity were supported. IRT analysis indicated that response categories were located in order according to severity. K6 provided reliable information regarding higher levels of psychological distress. The findings suggest that the Vietnamese version of the K6 is a reliable and valid instrument to measure psychological distress among hospital nurses in Vietnam.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Since Covid-19 started, it has created nothing but puzzle in the investment field. This paper adds more knowledge to ESG funds by investigating the performance of 96 ESG ETFs during the Covid-19 ...market stress. My findings show that ESG ETFs outperformed the market during the pandemic, suggesting they were better immune investments than other investment tools. This addresses the controversy that ESG funds are more likely of having actual investment performance value than just being of marketing tools. In addition, this paper examines whether ESG ETFs attempted to track their indexes exactly, and the results indicate that ETF funds did an excellent job on tracking their indexes they followed before Covid-19 and Covid-19 recovery except for during Covid-19 since their indexes were harder to track during the outbreak. This paper also provides discussion on why ESG funds were better immune investment tools. My findings and discussions aim to inform investors and portfolio managers in decision making during this outbreak.
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