Reaction of size-selected iron-oxide cluster cations with methane: a model study of rapid methane loss in Mars' atmosphere.

We report gas-phase reactions of free iron-oxide clusters, FenOm+, and their Ar adducts with methane in the context of chemical processes in Mars' atmosphere. Methane activation was observed to produce FenOmCH2+/FenOmCD2+ and FenOmC+, where the reactivity exhibited size and composition dependence. For example, the rate coefficients of methane activation for Fe3O+ and Fe4O+ were estimated to be 1 × 10-13 and 3 × 10-13 cm3 s-1, respectively. Based on these reaction rate coefficients, the presence of iron-oxide clusters/particles with a density as low as 107 cm-3 in Mars' atmosphere would explain the rapid loss of methane observed recently by the Curiosity rover.

Photoelectron Imaging Signature for Selective Formation of Icosahedral Anionic Silver Cages Encapsulating Group 5 Elements: M@Ag12- (M = V, Nb, and Ta).

An assembly of 13 atoms can form highly symmetric architectures like those belonging to D3h, Oh, D5h, and Ih point groups. Here, using photoelectron imaging spectroscopy in combination with density functional theory (DFT) calculations, we present a simple yet convincing experimental signature for the selective formation of icosahedral cages of anionic silver clusters encapsulating a dopant atom of group 5 elements: M@Ag12- (M = V, Nb, and Ta). Their photoelectron images obtained at 4 eV closely resemble one another: only a single ring is observed, which is assignable to photodetachment signals from a 5-fold degenerate superatomic 1D electronic shell in the 1S21P61D10 configuration of valence electrons. The perfect degeneracy represents an unambiguous fingerprint of an icosahedral symmetry, which would otherwise be lifted in all of the other structural isomers. DFT calculations confirm that Ih forms are the most stable and that D5h, Oh, and D3h structures are not found even in metastable states.

Nut consumption during pregnancy is associated with decreased risk of peer problems in 5-year-old Japanese children.

OBJECTIVES: Nuts are nutrient-dense foods rich in unsaturated fatty acids, protein, dietary fiber, vitamins, and minerals. The present prebirth cohort study examined the association between maternal nut intake during pregnancy and the risk of childhood behavioral problems in 5-year-old Japanese children. METHODS: Study subjects were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional problems, conduct problems, hyperactivity problems, peer problems, and low prosocial behavior were assessed using the parent-reported version of the Strengths and Difficulties Questionnaire. Adjustments were made for a priori-selected nondietary confounders and potentially related dietary factors. RESULTS: Compared with mothers who had not eaten nuts during pregnancy, mothers who had eaten nuts had a significantly reduced risk of peer problems in children; the adjusted odds ratio was 0.64 (95% confidence interval: 0.42-0.97). There were no measurable associations between maternal consumption of nuts during pregnancy and the risk of childhood emotional problems, conduct problems, hyperactivity problems, and low prosocial behavior. CONCLUSIONS: Maternal consumption of nuts during pregnancy may be associated with a decreased risk of peer problems in 5-year-old children.

Distinct motifs in the E protein are required for SARS-CoV-2 virus particle formation and lysosomal deacidification in host cells.

IMPORTANCE: Severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19), has caused a global public health crisis. The E protein, a structural protein found in this virus particle, is also known to be a viroporin. As such, it forms oligomeric ion channels or pores in the host cell membrane. However, the relationship between these two functions is poorly understood. In this study, we showed that the roles of E protein in virus particle and viroporin formation are distinct. This study contributes to the development of drugs that inhibit SARS-CoV-2 virus particle formation. Additionally, we designed a highly sensitive and high-throughput virus-like particle detection system using the HiBiT tag, which is a useful tool for studying the release of SARS-CoV-2.

Photodestruction Action Spectroscopy of Silver Cluster Anions, AgN- (N = 3-19), with a Linear Ion Trap: Observation of Bound Excited States above the Photodetachment Threshold.

Electron detachment thresholds of metal cluster anions, MN-, are a few electron volts. The excess electron is therefore detached by visible or ultraviolet light, which also creates low-lying bound electronic states, MN-*; i.e., MN-* energetically overlaps with the continuum, MN + e-. Here, we perform action spectroscopy of photodestruction, leading either to photodetachment or to photofragmentation, for size-selected silver cluster anions, AgN- (N = 3-19), to unveil such bound electronic states embedded in the continuum. The experiment takes advantage of a linear ion trap that enables us to measure photodestruction spectra with high quality at well-defined temperatures, where bound excited states, AgN-*, are clearly identified above their vertical detachment energies. Structural optimization of AgN- (N = 3-19) is conducted by using density functional theory (DFT), which is followed by calculations of vertical excitation energies by time-dependent DFT to assign the observed bound states. Spectral evolution observed as a function of cluster size is also discussed, where the optimized geometries are found to be closely related to the observed spectral profiles. A plasmonic band consisting of nearly degenerate individual excitations is observed for N = 19.

Protein Pull-down Assay Using HiBiT-tag-dependent Luciferase Activity Measurement.

Co-immunoprecipitation or pull-down assays are frequently used to analyze protein-protein interactions. In these experiments, western blotting is commonly used to detect prey proteins. However, sensitivity and quantification problems remain in this detection system. Recently, the HiBiT-tag-dependent NanoLuc luciferase system was developed as a highly sensitive detection system for small amounts of proteins. In this report, we introduce the method of using HiBiT technology for the detection of prey protein in a pull-down assay. Using this protocol, we demonstrate the formation of a ternary complex consisting of Japanese encephalitis virus NS4B and two host factors, namely valosin-containing protein, and nuclear protein localization protein 4, which is a critical biological event during flavivirus replication in cells.

A highly sensitive NanoLuc-based protease biosensor for detecting apoptosis and SARS-CoV-2 infection.

Proteases play critical roles in various biological processes, including apoptosis and viral infection. Several protease biosensors have been developed; however, obtaining a reliable signal from a very low level of endogenous protease activity remains a challenge. In this study, we developed a highly sensitive protease biosensor, named FlipNanoLuc, based on the Oplophorus gracilirostris NanoLuc luciferase. The flipped ß-strand was restored by protease activation and cleavage, resulting in the reconstitution of luciferase and enzymatic activity. By making several modifications, such as introducing NanoBiT technology and CL1-PEST1 degradation tag, the FlipNanoLuc-based protease biosensor system achieved more than 500-fold luminescence increase in the corresponding protease-overexpressing cells. We demonstrated that the FlipNanoLuc-based caspase sensor can be utilized for the detection of staurosporine-induced apoptosis with sixfold increase in luminescence. Furthermore, we also demonstrated that the FlipNanoLuc-based coronavirus 3CL-protease sensor can be used to detect human coronavirus OC43 with tenfold increase in luminescence and severe acute respiratory syndrome-coronavirus-2 infections with 20-fold increase in luminescence by introducing the stem-loop 1 sequence to prevent the virus inducing global translational shutdown.

Pre- and postnatal maternal hair dye use and risk of wheeze and asthma in 5-year-old Japanese children: the Kyushu Okinawa Maternal and Child Health Study.

The present study investigated the association between pre- and postnatal maternal hair dye use and the risk of wheeze and asthma in Japanese children aged 5 years. Study participants were 1199 mother-child pairs. Information on the variables under study was obtained using repeated questionnaires completed by parents. Prenatal maternal hair dye use was associated with an increased risk of current wheeze and ever doctor-diagnosed asthma; the adjusted odds ratios (ORs) (95% confidence intervals [CIs]) were 1.44 (1.02-2.02) and 1.51 (1.00-2.25), respectively. Postnatal maternal hair dye use was related to the risk of doctor-diagnosed asthma; the adjusted OR (95% CI) was 1.58 (1.03-2.40). Children who were exposed to maternal hair dye use both prenatally and postnatally had an increased risk of childhood current wheeze and ever doctor-diagnosed asthma; the adjusted ORs (95% CIs) were 1.59 (1.03-2.42) and 1.76 (1.06-2.88), respectively. Our findings suggest that perinatal maternal hair dye use is associated with the risk of wheeze and asthma in children.

Sex differences in the association between smoking exposure and prevalence of wheeze and asthma in 3-year-old children.

OBJECTIVE: We examined independent and joint associations between prenatal and postnatal smoking exposure and the prevalence of wheeze and asthma among 3-year-old Japanese children. Sex differences were also investigated. METHODS: Smoking exposure, allergic symptoms, and potential confounding factor data were collected using a self-administered questionnaire. Wheeze was defined on the basis of the International Study of Asthma and Allergies in Childhood criteria. Physician-diagnosed asthma was considered to be present if a physician had diagnosed the child with asthma any time before the survey was administered. RESULTS: There were 6402 pediatric participants in this study. Maternal smoking throughout pregnancy and household smoking exposure during the first year of life were associated with an increased prevalence of wheeze among girls but not boys (adjusted odds ratio (OR) [95% CI] = 2.00 [1.13-3.42] and 1.34 [1.07-1.68], respectively). Girls exposed to both prenatal maternal smoking and postnatal household smoking exposure had a significantly higher prevalence of wheeze and physician-diagnosed asthma compared with girls without these exposures (adjusted OR [95% CI] = 2.06 [1.39-3.01] and 1.86 [1.01-3.26], respectively). No association was observed between perinatal smoking exposure and the prevalence of wheeze or asthma among boys. Significant interactions between sex and smoking exposure affecting wheeze and asthma were also found (p for interaction = 0.0003 and 0.01, respectively). CONCLUSION: We found a positive association between perinatal smoking exposure and the prevalence of wheeze and asthma only among girls. Effects of perinatal smoking exposure on wheeze and asthma might be sex specific. Further research is required.

Maternal Consumption of Dairy Products during Pregnancy Is Associated with Decreased Risk of Emotional Problems in 5-Year-Olds: The Kyushu Okinawa Maternal and Child Health Study.

Milk is a good source of fats, minerals, and vitamins. The present prebirth cohort study examined the association between maternal dairy product intake during pregnancy and the risk of childhood behavioral problems in 5-year-old Japanese children. Study subjects were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional problems, conduct problems, hyperactivity problems, peer problems, and low prosocial behavior were assessed using the parent-reported version of the Strengths and Difficulties Questionnaire. Adjustments were made for a priori selected non-dietary confounders and potentially related dietary factors. A significant inverse exposure-response association was observed between maternal total dairy intake during pregnancy and the risk of childhood emotional problems (adjusted odds ratio [OR] between extreme quartiles, 0.62; 95% confidence interval [CI]: 0.36-1.03, p for trend, 0.04). The greater maternal consumption of cow's milk, but not yogurt or cheese, during pregnancy was independently related to a reduced risk of emotional problems in children (adjusted OR between extreme quartiles, 0.41; 95% CI: 0.23-0.70, p for trend, 0.003). Higher maternal consumption levels of total dairy products, especially cow's milk, during pregnancy may be associated with a decreased risk of emotional problems in 5-year-old children.

Photoelectron imaging of size-selected metal cluster anions in a quasi-continuous mode.

We present a novel high-repetition-rate photoelectron imaging (PEI) apparatus for exploring electronic structures of metal cluster anions. A continuous beam of mass-selected metal cluster anions, generated by a magnetron-sputtering cluster-ion source coupled with a quadrupole mass filter, is chopped into sub-megahertz ion bunches using a high-voltage pulser. The quasi-continuous anion beam is introduced into a PEI spectrometer, where the anions are photodetached using a 404 nm (3.07 eV) continuous-wave laser diode. As a demonstration, we acquire photoelectron images for size-selected Ag cluster anions, AgN - (N = 3, 7, 14), and show that each image can be obtained in a short accumulation time (50 s) with a kinetic energy resolution (ΔE/E) of 4% at E = 1.77 eV. The quasi-continuous PEI technique enables high-count-rate, space-charge-free acquisition of photoelectron spectra and angular distributions not only from size-selected metal cluster anions but also from anions prepared by other continuous ion sources, such as electrospray ionization.

Exploring s-d, s-f, and d-f Electron Interactions in AgnCe+ and AgnSm+ by Chemical Reaction toward O2.

We investigate gas-phase reactions of free AgnCe+ and AgnSm+ clusters with oxygen molecules to explore s-d, s-f, and d-f electron interactions in the finite size regime; a Ce atom has a 5d electron as well as a 4f electron, whereas a Sm atom has six 4f electrons without 5d electrons. In the reaction of AgnCe+ (n = 3-20), the Ce atom located on the cluster surface provides an active site except for n = 15 and 16, as inferred from the composition of the reaction products with oxygen bound to the Ce atom as well as from their relatively high reactivity. The extremely low reactivity for n = 15 and 16 is due to encapsulation of the Ce atom by Ag atoms. The minimum reactivity observed at n = 16 suggests that a closed electronic shell with 18 valence electrons is formed with a delocalized Ce 5d electron, while the localized Ce 4f electron does not contribute to the shell closure. As for AgnSm+ (n = 1-18), encapsulation of the Sm atom was observed for n ≥ 15. The lower reactivity at n = 17 than at n = 16 and 18 implies that an 18-valence-electron shell closure is formed with s electrons from Ag and Sm atoms; Sm 4f electrons are not involved in the shell closure as in the case of AgnCe+. The present results suggest that the 4f electrons tend to localize on the lanthanoid atom, whereas the 5d electron delocalizes to contribute to the electron shell closure.

Psychosocial characteristics of victims of special fraud among Japanese older adults: A cross-sectional study using scam vulnerability scale.

Despite the police preventing special fraud victimisation of older adults, both the number of cases and the amount of damage have remained high in Japan. 'Special fraud', in Japan, is a crime in which victims are tricked by fraudsters who through phone or postcards impersonate the victims' relatives, employees and other associates, to dupe the victims of their cash or other valuables. The number of recognised cases of special fraud has been turned to increase in 2021. Although police or consumer affairs administrations have been conducting all-encompassing enlightenment or public education for prevention, it is also necessary to reach out to those who are vulnerable to fraud. In this study, we determine the psychosocial characteristics of victims of special fraud in Japanese older adults. We analysed the age, gender, education, residential status, household satisfaction, risk perception and scam vulnerability scale of 56 older adults aged 60 years or older (mean age: 79.34 ± 7.51 years, 49 women) who had been victims of special fraud and 99 older adults aged 60 years or older (mean age: 77.73 ± 5.69 years, 61 women) who had never been victims of special fraud. The study found that the victimised older adults were more likely to be females who live alone and go out less frequently than the non-victimised older adults. The total scores of the scam vulnerability scale were higher among the elderly victims of special fraud compared to those who had never been scammed, suggesting that the psychosocial characteristics of victims of special fraud among older adults are being female, living alone, going out infrequently, having high confidence against fraud victimisation and responding quickly to phone calls and unknown visitors. Therefore, government agencies or family members should take care of older women who meet these characteristics to reduce their contact with fraudsters.

Tryptophan intake is related to a lower prevalence of depressive symptoms during pregnancy in Japan: baseline data from the Kyushu Okinawa Maternal and Child Health Study.

OBJECTIVE: Tryptophan is an essential amino acid wholly derived from diet. While the majority of tryptophan is degraded through the kynurenine pathway into neuroactive metabolites like quinolinic acid and kynurenic acid, a small proportion of ingested tryptophan is metabolized into the neurotransmitter serotonin. The current cross-sectional study in Japan examined the association between tryptophan intake and depressive symptoms during pregnancy. METHODS: Study subjects were 1744 pregnant women. Dietary intake during the preceding month was assessed using a self-administered diet history questionnaire. Depressive symptoms were defined as a score ≥ 16 on the Center for Epidemiologic Studies Depression Scale. Adjustment was made for age, gestation, region of residence, number of children, family structure, history of depression, family history of depression, smoking, secondhand smoke exposure at home and at work, employment, household income, education, body mass index, and intake of saturated fatty acids, eicosapentaenoic acid plus docosahexaenoic acid, calcium, vitamin D, and isoflavones. RESULTS: The prevalence of depressive symptoms during pregnancy was 19.2%. After adjustment for confounding factors, higher tryptophan intake was independently inversely associated with the prevalence of depressive symptoms during pregnancy: the adjusted prevalence ratios (95% confidence intervals) for depressive symptoms during pregnancy in the first, second, third, and fourth quartiles of tryptophan intake were 1 (reference), 0.99 (0.76-1.28), 0.94 (0.71-1.25), and 0.64 (0.44-0.93), respectively (p for trend = 0.04). CONCLUSIONS: Higher estimated tryptophan intake was cross-sectionally independently associated with a lower prevalence of depressive symptoms during pregnancy in Japanese women.

Maternal calcium intake during pregnancy and childhood blood pressure: the Kyushu Okinawa Maternal and Child Health Study.

PURPOSE: Evidence regarding the relationship between maternal calcium intake during pregnancy and childhood blood pressure is limited and inconsistent. The present prebirth cohort study examined this issue in Japanese children aged 6 years. METHODS: Subjects were 854 mother-child pairs. Maternal intake during pregnancy was assessed with a validated diet history questionnaire. A research technician measured systolic and diastolic blood pressures at home in children aged 6 years using an electronic sphygmomanometer. Analysis of covariance was used to calculate adjusted means of systolic and diastolic blood pressures according to maternal calcium intake during pregnancy. RESULTS: Maternal calcium intake during pregnancy was not related to systolic blood pressure in children. On the other hand, compared with children of mothers whose calcium intake during pregnancy was in the lowest quartile, those of mothers whose calcium intake during pregnancy was in the highest quartile had 2.8 mmHg lower adjusted mean diastolic blood pressure (95% confidence interval: 0.3-5.3 mmHg, P for trend = .009). CONCLUSIONS: Higher maternal calcium intake during pregnancy may be associated with a decrease in diastolic, but not systolic, blood pressure in Japanese children aged 6 years.

Flavivirus recruits the valosin-containing protein-NPL4 complex to induce stress granule disassembly for efficient viral genome replication.

Flaviviruses are human pathogens that can cause severe diseases, such as dengue fever and Japanese encephalitis, which can lead to death. Valosin-containing protein (VCP)/p97, a cellular ATPase associated with diverse cellular activities (AAA-ATPase), is reported to have multiple roles in flavivirus replication. Nevertheless, the importance of each role still has not been addressed. In this study, the functions of 17 VCP mutants that are reportedly unable to interact with the VCP cofactors were validated using the short-interfering RNA rescue experiments. Our findings of this study suggested that VCP exerts its functions in replication of the Japanese encephalitis virus by interacting with the VCP cofactor nuclear protein localization 4 (NPL4). We show that the depletion of NPL4 impaired the early stage of viral genome replication. In addition, we demonstrate that the direct interaction between NPL4 and viral nonstructural protein (NS4B) is critical for the translocation of NS4B to the sites of viral replication. Finally, we found that Japanese encephalitis virus and dengue virus promoted stress granule formation only in VCP inhibitor-treated cells and the expression of NS4B or VCP attenuated stress granule formation mediated by protein kinase R, which is generally known to be activated by type I interferon and viral genome RNA. These results suggest that the NS4B-mediated recruitment of VCP to the virus replication site inhibits cellular stress responses and consequently facilitates viral protein synthesis in the flavivirus-infected cells.

Correction: Electron counting in cationic and anionic silver clusters doped with a 3d transition-metal atom: endo- vs. exohedral geometry.

Correction for 'Electron counting in cationic and anionic silver clusters doped with a 3d transition-metal atom: endo- vs. exohedral geometry' by Kento Minamikawa et al., Phys. Chem. Chem. Phys., 2022, DOI: 10.1039/d1cp04197e.

Electron counting in cationic and anionic silver clusters doped with a 3d transition-metal atom: endo- vs. exohedral geometry.

Electron counting is a concept that often governs properties of molecules, clusters, and complexes. Here we explore silver clusters doped with a transition-metal atom, where it has been an issue whether or not 3d electrons delocalize to participate in electron counting. The experiment is performed on AgNM+/- (M = Sc-Ni) clusters to examine their stability through chemical reactivity, enabling systematic control of the number of valence electrons by the cluster size, the charge state, and the transition-metal element across the periodic table. It is revealed for 18-valence-electron clusters that 3d electrons participate in electron counting to show exceptional stability only when the transition-metal atom is endohedrally doped, except for Cr and Mn doping that forces 3d electrons to localize. We thus present new entries for superatomic metal clusters as well as a geometric factor that regulates the behavior of 3d electrons in the nanoscale regime.

Maternal metal intake during pregnancy and childhood behavioral problems in Japan: the Kyushu Okinawa Maternal and Child Health Study.

OBJECTIVES: Lower maternal metal intake during pregnancy might affect childhood development. The current prebirth cohort study investigated the relationship between maternal intake of zinc, magnesium, iron, copper, and manganese during pregnancy and behavioral problems in Japanese children aged five years. METHODS: Subjects were 1199 mother-child pairs. Dietary intake during the preceding month was assessed using a diet history questionnaire. Emotional, conduct, hyperactivity, and peer problems and low prosocial behavior were assessed using the Strengths and Difficulties Questionnaire. Maternal age, gestation at baseline, region of residence, number of children, maternal and paternal education, household income, maternal depressive symptoms during pregnancy, maternal alcohol intake during pregnancy, maternal smoking during pregnancy, child's birth weight, child's sex, breastfeeding duration, smoking in the household during the first year of life, and some dietary confounders that were associated with outcomes under study in this population were adjusted for. RESULTS: Compared with maternal magnesium intake during pregnancy in the first quartile, magnesium intake in the second, third, and fourth quartiles was independently inversely related to childhood hyperactivity problems, but not to emotional, conduct, or peer problems or low prosocial behavior: the adjusted odds ratio between extreme quartiles was 0.48 (95% confidence interval: 0.23-0.99, P for trend = 0.04). No evident associations were observed between maternal intake of zinc, iron, copper, or manganese during pregnancy and childhood emotional, conduct, hyperactivity, or peer problems or low prosocial behavior. CONCLUSIONS: The present study suggests that higher maternal magnesium intake during pregnancy is inversely associated with hyperactivity problems in Japanese children.

Perinatal maternal depressive symptoms and risk of behavioral problems at five years.

BACKGROUND: Evidence on the association between perinatal maternal depression and children's behavioral development is limited. We investigated the association between maternal depressive symptoms during pregnancy and postpartum and the risk of childhood behavioral problems using data from a birth cohort study. METHODS: Study subjects were 1199 mother-child pairs. Maternal depressive symptoms were assessed with the Center for Epidemiologic Studies Depression Scale during pregnancy and the Edinburgh Postnatal Depression Scale at 4 months postpartum. Children's behavioral development at 5 years of age was assessed with the Strengths and Difficulties Questionnaire. RESULTS: Compared with children whose mothers did not experience depressive symptoms during pregnancy, those whose mothers did experience depressive symptoms during pregnancy had increased risk of emotional symptoms, conduct problems, hyperactivity, peer problems, and low prosocial behavior. Maternal depressive symptoms at around 4 months postpartum were associated with increased risk of childhood emotional problems. Compared with children whose mothers did not experience depressive symptoms during the perinatal period, those whose mothers did experience depressive symptoms both during pregnancy and postpartum had a fivefold increased risk of childhood emotional symptoms and a threefold increased risk of peer problems. CONCLUSIONS: Our findings suggest that perinatal maternal depression is associated with behavioral problems in children. IMPACT: Several epidemiological studies in Western countries have examined the association between perinatal maternal depression and children's behavioral development, yet the results are conflicting and inconclusive. There is limited evidence on this topic in Asia. In our study using data from a prospective pregnancy birth cohort, maternal depressive symptoms around 4 months postpartum were associated with an increased risk of emotional symptoms in children aged 5 years. Children whose mothers had exhibited depressive symptoms both during pregnancy and postpartum had a fivefold increased risk of childhood emotional symptoms and a threefold increased risk of peer problems.