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The four-electron oxygen reduction reaction (4e--ORR) is the mainstay in chemical energy conversion. Elucidation of factors influencing the catalyst's reaction rate and selectivity is important in the development of more active catalysts of 4e--ORR. In this study, we investigated chemical and electrochemical 4e--ORR catalyzed by Co2(μ-O2) complexes bridged by xanthene (1) and anthracene (3) and by a Co2(OH)2 complex bridged by anthraquinone (2). In the chemical ORR using Fe(CpMe)2 as a reductant in acidic PhCN, we found that 1 showed the highest initial turnover frequency (TOFinit = 6.8 × 102 s-1) and selectivity for 4e--ORR (96%) in three complexes. The detailed kinetic analyses have revealed that the rate-determining steps (RDSs) in the catalytic cycles of 1-3 have the O2 addition to [CoII2(OH2)2]4+ as an intermediate in common. In the only case that complex 1 was used as a catalyst, kcat depended on proton concentration because the reaction rate of the O2 addition to [CoII2(OH2)2]4+ was so fast as compared to that of the concerted PCET process of 1. Through X-ray, Raman, and electrochemical analyses and stoichiometric reactions, we found the face-to-face structure of 1 characterized by a slightly flexible xanthene was advantageous in capturing O2 and stabilizing the Co2(μ-O2) structure, thus increasing both the reaction rate and selectivity for 4e--ORR.

Despite a decade of sustained malaria control, malaria remains a serious public health problem in the Democratic Republic of Congo (DRC). Children under five years of age and school-age children aged 5–15 years remain at high risk of symptomatic and asymptomatic malaria infections. The World Health Organization’s malaria control, elimination, and eradication recommendations are still only partially implemented in DRC. For better malaria control and eventual elimination, the integration of all individuals into the national malaria control programme will strengthen malaria control and elimination strategies in the country. Thus, inclusion of schools and school-age children in DRC malaria control interventions is needed.

Background: In Tsarang (at 3560 m), which is located in Mustang, 62.7% of the residents answered that they had a subjective medical history of arthritis, and 41.1% of the residents answered that their families had a subjective medical history of arthritis on a survey conducted in 2017. The expression of hypoxia-inducible factor (HIF) and its efects are deeply involved in hypoxic adaptation in Tibetan highlanders. At the same time, HIF is also related to the onset of rheumatoid arthritis. Therefore, the adaptive mechanism acquired by Tibetan highlanders may promote the development of rheumatoid arthritis. The prevalence of rheumatoid arthritis is estimated to be approximately 0.5–1.0% worldwide. The objective of this study was to estimate the prevalence of rheumatoid arthritis in Tsarang residents using existing diagnostic criteria and to explore its risk factors. Methods: An epidemiological survey was conducted in Tsarang in 2019. Data obtained from anthropometry and questionnaires were statistically analyzed. Biochemical measurements using blood samples were also performed, and the results were used to assess arthritis status. Residents’ joint status was scored, and arthritis was assessed based on the clinical disease activity index and ACR/EULAR 2010 criteria. Results: Twenty-seven males and 50 females participated in this survey. In Tsarang, ACR/EULAR 2010 classifed 4.3% of males and 7.1% of females as having rheumatoid arthritis, indicating a very high estimated prevalence. We also performed a multivariate analysis to explore its risk factors, and two factors, older age (standardized parameter estimate = 4.84E−01, 95% CI = [9.19E−02, 8.76E−01], p = 0.0170) and a history of living in urban areas (standardized parameter estimate = − 5.49E−01, 95% CI = [− 9.21E−01, 1.77E−01], p = 0.0050), signifcantly contributed to the higher ACR/EULAR 2010 score in females. In addition, three factors, having no spouse (standardized parameter estimate = 3.17E−01, 95% CI = [5.74E−02, 5.77E−01], p = 0.0179), having a smoking habit (standardized parameter estimate = 2.88E−01, 95% CI = [1.71E−02, 5.59E−01], p = 0.0377), and a history of living in urban areas (standardized parameter estimate = − 3.69E−01, 95% CI = [− 6.83E−01, − 5.60E−02], p = 0.0219), resulted in signifcantly higher clinical disease activity index scores in females. Furthermore, smoking habits were found to signifcantly increase blood hyaluronic acid in both males (standardized parameter estimate = 6.03E−01, 95% CI = [3.06E−01, 9.01E−01], p = 0.0020) and females (standardized parameter estimate = 4.87E−01, 95% CI = [5.63E−02, 9.18E−01], p = 0.0291)., Journal of Physiological Anthropology, 41(1), art.no. 12; 2022

Background Many studies have indicated specific low-hemoglobin (Hb) adaptation to high altitude in the Tibetan population, but studies focusing on physiological variations within this population are limited. This study aimed to investigate the relationships between SpO2 and related factors, including individual variations and sex differences, to assess the generality of high-altitude adaptation in the Tibetan population of Tsarang. Methods The participants were 31 male and 41 female community-dwelling people aged ≥18 years living in Tsarang, in the Mustang district of Nepal. Height, weight, SpO2, Hb concentration, finger temperature, heart rate, and blood pressure were measured. Lifestyle information was obtained by interview. Results Men had significantly higher systolic blood pressure (p = 0.002) and Hb (p < 0.001) than women. There was no significant correlation between SpO2 and other parameters in men. In women, SpO2 was negatively correlated with heart rate (p = 0.036), Hb (p = 0.004), and finger temperature (p = 0.037). In multiple regression analysis, a higher SpO2 was marginally correlated with lower age (β = −0.109, p = 0.086) and higher Hb (β = 0.547, p = 0.053) in men. In women, higher SpO2 was significantly correlated with lower heart rate (β = −0.045, p = 0.036) and Hb (β = −0.341, p = 0.018). Mean hemoglobin (95% confidence interval) was 13.6 g/dl (13.1–14.0 g/dl), which is lower than that found previously in Andeans and almost equal to that in Japanese lowlanders measured using the same device. In some participants of both sexes, hemoglobin was >17.0 g/dl. Conclusion Higher SpO2 was marginally correlated with younger age and higher Hb in men and with lower heart rate and lower Hb in women. Hemoglobin concentration was similar to that found previously in lowlanders, but higher in some individuals. These results indicate individual variation and sex differences in the hemodynamics of high-altitude adaptation in Tibetan highlanders of Tsarang, as well as low-Hb adaptation to high altitude equal to that of other Tibetans.

Many studies have indicated specific low-hemoglobin (Hb) adaptation to high altitude in the Tibetan population, but studies focusing on physiological variations within this population are limited. This study aimed to investigate the relationships between SpOThe participants were 31 male and 41 female community-dwelling people aged ≥18 years living in Tsarang, in the Mustang district of Nepal. Height, weight, SpOMen had significantly higher systolic blood pressure (p = 0.002) and Hb (p0.001) than women. There was no significant correlation between SpOHigher SpO

The emergence and spread of Plasmodium falciparum parasites resistant to antimalarial drugs constitutes an obstacle to malaria control and elimination. This study aimed to identify the prevalence of polymorphisms in pfk13, pfmdr1, pfdhfr, pfdhps and pfcrt genes in isolates from asymptomatic and symptomatic school-age children in Kinshasa.Nested-PCR followed by sequencing was performed for the detection of pfk13, pfmdr1, pfdhfr, pfdhps and pfcrt polymorphisms.Two mutations in pfk13, C532S and Q613E were identified in the Democratic Republic of Congo for the first time. The prevalence of the drug-resistance associated mutations pfcrt K76T, pfdhps K540E and pfmdr1 N86Y was low, being 27%, 20% and 9%, respectively.We found a low prevalence of genetic markers associated with chloroquine and sulfadoxine-pyrimethamine resistance in Kinshasa. Furthermore, no mutations previously associated with resistance against artemisinin and its derivatives were observed in the pfK13 gene. These findings support the continued use of ACTs and IPTp-SP. Continuous molecular monitoring of antimalarial resistance markers is recommended.

Background: Loss of efcacy of diagnostic tests may lead to untreated or mistreated malaria cases, compromising case management and control. There is an increasing reliance on rapid diagnostic tests (RDTs) for malaria diagnosis, with the most widely used of these targeting the Plasmodium falciparum histidine-rich protein 2 (PfHRP2). There are numerous reports of the deletion of this gene in P. falciparum parasites in some populations, rendering them unde‑ tectable by PfHRP2 RDTs. The aim of this study was to identify P. falciparum parasites lacking the P. falciparum histidine rich protein 2 and 3 genes (pfhrp2/3) isolated from asymptomatic and symptomatic school-age children in Kinshasa, Democratic Republic of Congo. Methods: The performance of PfHRP2-based RDTs in comparison to microscopy and PCR was assessed using blood samples collected and spotted on Whatman 903™ flter papers between October and November 2019 from schoolage children aged 6–14 years. PCR was then used to identify parasite isolates lacking pfhrp2/3 genes. Results: Among asymptomatic malaria carriers (N=266), 49%, 65%, and 70% were microscopy, PfHRP2_RDT, and pfdh-qPCR positive, respectively. The sensitivity and specifcity of RDTs compared to PCR were 80% and 70% while the sensitivity and specifcity of RDTs compared to microscopy were 92% and 60%, respectively. Among sympto‑ matic malaria carriers (N=196), 62%, 67%, and 87% were microscopy, PfHRP2-based RDT, pfdh-qPCR and positive, respectively. The sensitivity and specifcity of RDTs compared to PCR were 75% and 88%, whereas the sensitivity and specifcity of RDTs compared to microscopy were 93% and 77%, respectively. Of 173 samples with sufcient DNA for PCR amplifcation of pfhrp2/3, deletions of pfhrp2 and pfhrp3 were identifed in 2% and 1%, respectively. Three (4%)of samples harboured deletions of the pfhrp2 gene in asymptomatic parasite carriers and one (1%) isolate lacked the pfhrp3 gene among symptomatic parasite carriers in the RDT positive subgroup. No parasites lacking the pfhrp2/3 genes were found in the RDT negative subgroup. Conclusion: Plasmodium falciparum histidine-rich protein 2/3 gene deletions are uncommon in the surveyed popu‑ lation, and do not result in diagnostic failure. The use of rigorous PCR methods to identify pfhrp2/3 gene deletions is encouraged in order to minimize the overestimation of their prevalence., Malaria Journal, 21(1), art. no. 126; 2022

Background: Tibetan highlanders have adapted to hypoxic environments through the development of unique mechanisms that suppress an increase in hemoglobin (Hb) concentration even in high-altitude areas. Hb concentrations generally decrease with increasing age. However, in the highlands, chronic altitude sickness is known to occur in the elderly population. To investigate how aging in a hypoxic environment affects Hb levels in Tibetan highlanders, we focused on the Mustang people, who live above 3500 m. We tried to clarify the pure relationship between aging and Hb levels in a hypoxic environment.Results: We found that the Hb concentration increased with increasing age in females but not in males. Multivariate analysis showed that age, pulse pressure, the poverty index, and vascular diameter were strongly correlated with the Hb concentration. Conclusions: We found unique Hb dynamics among female Tibetan highlanders. As seen in these Hb dynamics, there may be sex-based differences in the adaptive mechanism in Tibetan highlanders., Tropical Medicine and Health, 49(1), art.no.2; 2020

Balamuthia mandrillaris is a free-living amoeba that lives in soil and water near human settlements. B. mandrillaris was first isolated from a mandrill baboon that died at the San Diego Zoo Wildlife Park in California in 1986, and the first human infection was reported in 1990. Although reported B. mandrillaris infections are often not properly characterized, it appears that B. mandrillaris invades the living body from the soil and water, either via a wound or the nasal cavity. Most confirmed infections have originated in South and North America. B. mandrillaris inhabits warm climates and is recognized as a pathogen in warm areas such as desert climates and tropical climates. B. mandrillaris has been isolated from environmental samples since 2000, most of which originated from warm areas such as step climates, tropical climates, and desert climates. However, B. mandrillaris may survive in diverse environments, although fewer granulomatous amebic encephalitis patients have been reported in colder Japanese and Northern European regions. In the present study, we conducted a survey of 13 soil samples in Aomori Prefecture located at the northernmost tip of Japan Honshu and successfully isolated one strain of B. mandrillaris from soil for the first time in Japan. In addition, B. mandrillaris gene was detected from several soils. This confirms that B. mandrillaris is capable of spreading to a wider climatic region.

Seven years after the Great East Japan Earthquake, we investigated telomeres as a potential biomarker of maternal chronic stress in children according to the timing of exposure to the disaster. The subjects were children aged 5-9 years living in Rikuzentakata, Japan. Relative telomere length (rTL) was measured with PCR in saliva samples. The partial regression coefficient of the rTL was significantly shorter in the group of children conceived after the disaster than in the children who were in utero on the day of the disaster. Telomere length should be investigated as a biomarker for assessing disaster-related trauma in future studies.

Objectives: Microorganisms in environmental samples are identified by sequential screening, isolation, and culture steps, followed by the verification of physiological characteristics and morphological classification. Isolation and purification of Amoebae from soil samples is extremely complex, laborious, and time-consuming and require considerable expertise for morphological evaluation. PCR testing of soil DNA seems to be an effective means for protozoa habitat screening. In this study, we added Acanthamoeba sp. (MK strain) to soil and developed a method of extracting protozoan DNA from the soil. Methods: Soil allophane is a known DNA adsorbing substance that inhibits the PCR reaction. After comparing the soil properties and allophane contents of 7 soil samples, we attempted to combine multiple cell disruption and DNA purification methods to design an optimal soil DNA extraction method that can be used for downstream PCR analysis. Results: We compared five different crushing/refining methods. Amplification of the gene was confirmed by Acanthamoeba specific PCR in protocol V where the concentration of Acanthamoeba in soil (1.0 × 102/g) was the detection limit of PCR. Conclusion: The soil DNA extraction method following protocol V allows DNA amplification of protozoa, including Amoeba, which is difficult to cultivate, thus simplifying the investigation of protozoa habitats and genetic analyses. Keywords: Soil, DNA, Protozoan, PCR inhibitor, Allophane, Epidemiological survey

The shape and size of barium chromate nanoparticles formed using a water-in-oil microemulsion prepared from the anionic surfactant AOT were examined. As a result, nanowires, nanorods, and nanodots could be synthesized by changing the raw ion concentration and by adding ethanol as a poor solvent. The nanowires and nanorods were self-assembled. It has been shown that the aspect ratio of the generated nanoparticles decreased with increasing chromate ion concentration or due to the addition of ethanol. By contrast, the aspect ratio was almost constant even when the barium ion concentration was changed. The surfactant AOT was selectively adsorbed on the crystal faces of the barium chromate nanoparticles along the a- axis, where it suppressed the growth of their crystal face. Furthermore, the generated nanoparticles were self-assembled through hydrophobic interactions between the surface-anchored AOT molecules. In conclusion, it was clarified that the supersaturation ratio and the particle–surfactant interaction were important factors for controlling the shape and size of these inorganic nanoparticles using the microemulsion method.

New rotary-die ECAP (RD-ECAP) was applied to a commercial Al–Si–Mg (AC4C) alloy to improve the ductility, and the microstructural developments and mechanical properties of ECAPed specimens were investigated. The as-cast Al alloy was used after machining to a cylindrical shape. ECAP was performed at 543, 603 and 673 K. The microstructure changes of samples were examined. The Vickers microhardness was measured with respect to RD-ECAP passes and the tensile test was conducted to check the high-temperature ductility. The samples after ECAP showed very clean external surface without any edge cracking. The grain size was drastically decreased and saturated into 2–3 μm after six passes because the dynamic recovery occurred during the process. After 10 passes, a very homogenous microstructure was obtained. The longation of the alloy increased from 25% to 125% after 10 passes, and the m value was 0.21 after 20 passes.

ECAP (Equal-Channel Angular Pressing) can produce large strains in a billet without decreasing its original diameter or thickness and therefore is an attractive process for the production of alloys with fine grained microstructures. However, since the strain per pass through the die is not large in ECAP, about 10 passes are required to obtain a desired fine microstructure. In conventional ECAP, the pressed billet must be removed from the die and reinserted back for the next pressing cycle, making the ECAP process inefficient and difficult to control. The latter problem is eliminated in ECAP with a rotary die. Tests with an AC4C alloy have shown that ECAP processing up to 20 passes is possible without billet removal. After 10 passes, the AC4C alloy showed 2–3 μm grain sizes, which enhanced the tensile ductility at 723 K up to about 126%. The tensile specimens showed a smooth surface after testing.

Ethane is directly converted to ethanol by the photochemical reaction at temperatures lower than 100 °C in atmospheric pressure. The conversion reaction is initiated by the hydroxyl radicals formed in the photolysis of water vapor. The conversion coefficient of ethane was 7.7% at 5h, and the selectivity 33.3%.

Ethane is directly converted to ethanol by the photochemical reaction at temperatures lower than 100 °C in atmospheric pressure. The conversion reaction is initiated by the hydroxyl radicals formed in the photolysis of water vapor. The conversion coefficient of ethane was 7.7% at 5h, and the selectivity 33.3%.