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The dynamics of phytoplankton biomass in the vertically mixed south-eastern part of the Bisan Strait, in the Seto Inland Sea of Japan, may be considered to be strongly dependent not only on nutrients but also on light status. This was investigated by examining variations in chlorophyll-a (Chl-a), nutrients, and Secchi-disc depth through high-frequency sampling (a mean of once every 1.7 days) at the same station from April to October 2019. Precipitation during the Japanese rainy season (East Asian monsoon rains) was associated with a decrease in salinity from 32 to 31 in late July. The highest concentration of dissolved inorganic nitrogen (DIN), the most deficient nutrient, also was recorded in late July in association with seasonal precipitation. However, the measured Chl-a peak (max. 4 μg l−1) in early August was not as high as expected, possibly due to low water clarity. A relatively small but substantial peak of DIN (max. 4 μM) was recorded in mid-August, which coincided with the passing of a typhoon. The small peak of DIN coupled with higher water clarity thereafter was followed by a phytoplankton bloom from mid-August to early September, at which the highest Chl-a (7 μg l−1) occurred. It is suggested that increased light penetration enhanced the efficiency of nutrient assimilation and thereby triggered the late-summer phytoplankton bloom. In contrast to the adjacent stratified areas, light rather than nutrient status appears to be the key determinant for the onset of phytoplankton blooms in the Bisan Strait.
The Tarim Basin is the major source of aeolian dust in the northern hemisphere. Glacial activity in the mountains, transportation by rivers and homogenization by wind are believed to be responsible for dust production within the basin. However, the major source(s) and homogenization process(es) are not clear. Moreover, provenance studies on fine fractions have never been conducted. Here, we measured electron spin resonance (ESR) signal intensity and the crystallinity index of quartz in fine (< 16 μm) and coarse (> 64 μm) fractions of river sediments, dry lake sediments and mountain loess to examine the process(es) that produce aeolian dust. The result suggests that the coarse fraction of the river sediment was derived from the bedrock in the drainage area. The ESR signal intensity and crystallinity index of the fine fraction of river sediments from the Tian Shan Mountains and mountainous rivers in the westernmost Kunlun and Pamir mountains are also similar to the coarse fraction, suggesting the same sources. However, the ESR signal intensity and crystallinity index of the fine fraction of river sediments from the Kunlun Mountains are different from the coarse fraction and converge towards values close to the average for the fine fraction of river sediments and mountain loess. Convergence of the ESR and crystallinity index values for the fine fraction of river sediments from the Kunlun Mountains can be explained by contamination of the river sediments by aeolian dust. The convergent values resulted from the homogenization of fine detrital material by repeated recycling within the basin.
Sensors based on the surface plasmon resonance (SPR) technique are useful devices to detect and monitor interactions between biomolecules in real-time. SPR is a label-free method that monitors the variation of reflectivity of a biochip composed of a metal-coated glass prism and can be applied in several areas, such as biotechnology, food safety and clinical diagnosis. In the last years, several researchers have proven the efficiency of metallic nanoparticles (NPs) in the enhancement of SPR signal. This feature allowed the detection of biomolecules at very low concentration. Aiming to further enhance SPR signal towards the detection of proteins at low concentration and by a simple procedure, the present work compared the performance of gold and platinum bimetallic NPs (AuPtNPs) with that of monometallic gold NPs (AuNPs) in the enhancement of SPR signal. In order to evaluate the NPs, protein peanut agglutin (PNA) was used as target analyte and anti-PNA antibody was used as sensing molecule. Firstly NPs were functionalized with anti-PNA antibody and incubated with a solution containing PNA. Then, the NPs bound to PNA were injected into the SPR equipment containing a biochip previously modified with anti-PNA antibody. The results demonstrated that the AuPtNPs provided a 91-fold increase compared to the direct detection of free PNA in solution. In comparison with AuNPs, the signal generated by AuPtNPs was about 4 times higher. This encouraging result indicated that the application of bimetallic NPs may be a better strategy to further enhance sensitivity of SPR biosensors and could drive the development of new strategies that are not only simple, but also able to detect proteins at low concentrations, which is of great importance, especially in clinical diagnostics.
Aeolian dust input exerts significant influence on oceanic biogeochemical cycles and further potentially controls atmospheric CO2 concentrations. However, the possible link between long-term aeolian dust supply and primary productivity in the western North Pacific remains poorly understood. Here, we present a comprehensive study of major and trace elements and total organic carbon (TOC) concentrations of sediments from Integrated Ocean Drilling Program (IODP) Site U1430 in the southern Japan Sea, in order to reconstruct oceanic palaeoproductivity evolution and test its possible link to Asian dust input since 4 Ma. Palaeoproductivity proxies indicate remarkable increases in productivity at ∼3–2 Ma followed by high-frequency oscillations in productivity since 1.2 Ma. We suggest that higher dust-derived iron supply from Central Asia at 3–2 Ma, which was likely driven by the growth of the Northern Hemisphere ice sheets, could account for enhanced primary productivity and export production in the Japan Sea. Such increased oceanic palaeoproductivity could enhance organic carbon burial, which might contribute to the decrease in atmospheric CO2 concentrations, and provide a positive feedback to the global cooling. However, the Tsushima Warm Current (TSWC) intrusion via the southern Tsushima Strait, which was controlled by glacioeustatic sea level changes, has been the principal cause of the rapid changes in primary productivity and benthic redox condition since 1.2 Ma, regardless of continuously increased Asian dust input.
We reconstruct the provenance of aluminosilicate sediment deposited in Ulleung Basin, Japan Sea, over the last 12 Ma at Site U1430 drilled during Integrated Ocean Drilling Program Expedition 346. Using multivariate partitioning techniques (Q-mode factor analysis, multiple linear regressions) applied to the major, trace and rare earth element composition of the bulk sediment, we identify and quantify four aluminosilicate components (Taklimakan, Gobi, Chinese Loess and Korean Peninsula), and model their mass accumulation rates. Each of these end-members, or materials from these regions, were present in the top-performing models in all tests. Material from the Taklimakan Desert (50–60 % of aluminosilicate contribution) is the most abundant end-member through time, while Chinese Loess and Gobi Desert components increase in contribution and flux in the Plio-Pleistocene. A Korean Peninsula component is lowest in abundance when present, and its occurrence reflects the opening of the Tsushima Strait at c. 3 Ma. Variation in dust source regions appears to track step-wise Asian aridification influenced by Cenozoic global cooling and periods of uplift of the Tibetan Plateau. During early stages of the evolution of the East Asian Monsoon, the Taklimakan Desert was the major source of dust to the Pacific. Continued uplift of the Tibetan Plateau may have influenced the increase in aeolian supply from the Gobi Desert and Chinese Loess Plateau into the Pleistocene. Consistent with existing records from the Pacific Ocean, these observations of aeolian fluxes provide more detail and specificity regarding the evolution of different Asian source regions through the latest Cenozoic.
This article reviews the semiconductor and metal-based nanohybrid-sensitized photoelectrochemical (PEC) cells for hydrogen generation from water. The nanoscale hybridization of sensitizers in the photoanode can enhance light harvesting, interfacial charge transfer, charge separation, and induce a catalytic effect in dependence on the kind of the components and interfacial junction state. Subsequent to the introduction, second and third sections present the basic structure and design of the nanohybrid-sensitized PEC cell. Fourth section deals with the effect of the interfacial bond between quantum dots and TiO2 on the electron injection process. Fifth section mainly describes the formation of heteroepitaxial junction between the components of nanohybrids. In the sixth section, the state-of-the-art nanohybrid-sensitized PEC cells are treated with a particular emphasis placed on the interface state.
We conducted a randomised, double-blind, placebo-controlled trial to elucidate the effects of dietary milk fat globule membrane (MFGM) on the physical performance of community-dwelling Japanese adults. For this 24-week study, 115 middle-aged subjects (range 50–70 years old) were invited, of whom 113 (seventy-two women, forty-one men) completed the trial. Participants were then divided into either the placebo control or MFGM group. Measurements of physical performance (without undertaking any mandatory exercise) examining muscle strength, agility and balance were tested every 6 weeks until 24 weeks. Analyses were performed using the intention-to-treat method for all participants. Although the effects of MFGM on muscle strength and agility were not significant, we noted that the parameter for balance (such as the ability to stand on one leg with eyes closed for longer durations) increased in the MFGM group (mean 10·1 (95 % CI 8·25, 12·4) s) compared with the placebo (mean 7·53 (95 % CI 6·11, 9·30) s) (P = 0·046). Similarly, application of the mixed-effect model for repeated measures under unstructured covariance also revealed that the effect of MFGM was significant when compared with the placebo (10·2 (95 % CI 8·33, 12·4) v. 7·61 (95 % CI 6·17, 9·30) s) (P = 0·045). In conclusion, we demonstrated that MFGM had an effect on the physical performance of community-dwelling Japanese adults despite mandatory exercise. However, studies using larger cohorts of individuals from different demographic backgrounds are required to further elucidate the mechanisms underlying these effects and to extend the application of MFGM.
Temperature-dependent variations in electric switching and transverse resistance of phase-change [(GeTe)2(Sb2Te3)]n (n=4 and 8) chalcogenide superlattice (CSL) films were studied using conductive scanning probe microscopy (SPM). Three temperature regions with different electric transport properties were recognized in point current-voltage (I-V) spectra and the surface potential maps measured with tantalum and platinum-coated SPM cantilevers. At around 80°C the switching voltage decreased abruptly from ∼2 V to 0.5 V and the thermal coefficient of resistance changes its sign, indicating different carrier transport mechanisms. The observed changes correlated with decrease in the surface potential by ∼150 meV from 25 to 150°C. The results were ascribed to an opening of the CSL electronic band gap near the Fermi energy caused by thermal stress, which led to the transition from a Dirac-like semimetal to a narrow-gap semiconductor.
Human organoid models recapitulate many aspects of the complex composition and function of native organs. One of the main challenges in developing these models is the growth and maintenance of three-dimensional tissue structures and proper cellular organization that enable function. Biomaterials play an important role by providing a defined and tunable three-dimensional environment that is required for complex cellular organization and organoid growth in vitro or in vivo. This review summarizes organoids of the respiratory and digestive system, and the use of biomaterials to improve upon these model systems.
We demonstrate formation of allylamine (AAm) and acrylic acid (AAc)-functionalized colloidal silicon nanocrystals (Si NCs) exhibiting near-infrared (NIR) luminescence and immobilization of the NCs on substrates via covalent bond. The surface functionalization is confirmed by IR absorption spectroscopy and specific binding property of functionalized NCs. Atomic force microscope observations reveal that AAm- and AAc-functionalized Si NCs are chemically immobilized on self-assembled monolayers via covalent bonds. The functionalized Si NCs exhibit photoluminescence in a NIR region (1.5–1.6 eV), which is not significantly affected by the functionalization.
Topological (GeTe)/(Sb2Te3) superlattices (SL) are of
practical interest for memory applications because of different mechanism of
electric conductance switching in the crystalline phase. In the work, electrical
switching behavior of individual SL grains was examined employing a multimode
scanning probe microscope (MSPM) in a lithography mode at room temperature.
Using programmed bias voltage with different amplitude and pulse duration, we
observed the position-dependent variations of the switching voltage and the
current injection delay for [(GeTe)2
(Sb2Te3)]4 SLs on Si(100). The results shed
a light on the role of electric field and hot-electron injection on the SL
Shiga-toxin-producing Escherichia coli (STEC) infections usually cause haemolytic uraemic syndrome (HUS) equally in male and female children. This study investigated the localization of globotriaosylceramide (Gb3) in human brain and kidney tissues removed from forensic autopsy cases in Japan. A fatal case was used as a positive control in an outbreak of diarrhoeal disease caused by STEC O157:H7 in a kindergarten in Urawa in 1990. Positive immunodetection of Gb3 was significantly more frequent in female than in male distal and collecting renal tubules. To correlate this finding with a clinical outcome, a retrospective analysis of the predictors of renal failure in the 162 patients of two outbreaks in Japan was performed: one in Tochigi in 2002 and the other in Kagawa Prefecture in 2005. This study concludes renal failure, including HUS, was significantly associated with female sex, and the odds ratio was 4·06 compared to male patients in the two outbreaks. From 2006 to 2009 in Japan, the risk factor of HUS associated with STEC infection was analysed. The number of males and females and the proportion of females who developed HUS were calculated by age and year from 2006 to 2009. In 2006, 2007 and 2009 in adults aged >20 years, adult women were significantly more at risk of developing HUS in Japan.
The present study aimed to investigate the correlation between mothers’ and children’s vegetable intake and whether children are conscious about their vegetable intake.
Cross-sectional study. Self-administered questionnaires for mothers and children, consisting of items regarding diet history, were distributed to children via homeroom teachers. We created dummy exposure variables for each quartile of mothers’ vegetable intake. Multiple regression analysis was performed with children’s vegetable intake as the outcome variable.
Two public elementary schools in a residential district of Tokyo, Japan.
Study participants were upper-grade children (aged 10–12 years) and their mothers (332 pairs of mothers and children).
The mean vegetable intake in mothers and children was 310 (sd 145) g/d and 276 (sd 105) g/d, respectively. A positive linear relationship was found between mothers’ and children’s vegetable intake even after adjustment for considerable covariates (P<0·001). When stratified by children’s consciousness, the positive linear relationship was more pronounced in children who were conscious of eating all their vegetables (P<0·001 for interaction with children’s consciousness).
Mothers’ vegetable intake was significantly correlated with children’s vegetable intake. However, this correlation was stronger in children who were conscious of eating all their vegetables. Our findings suggest that enhancing mother’s vegetable intake and health consciousness of children are indispensable prerequisites for increasing vegetable intake among children.
The present study investigated anticipation processes in L2 speech comprehension. French–Spanish late bilinguals were presented with high-constrained Spanish sentences. ERPs were time-locked on the article preceding the critical noun, which was muted to avoid overlapping effects. Articles that mis-matched the gender of the expected nouns triggered a negativity. A subsequent lexical recognition task revealed that words expected from the context were (falsely) recognised significantly more often than unexpected words, even though all were muted. Overall, the results suggest that anticipation processes are at play during L2 speech processing, and allow creating a memory trace of a word prior to presentation.