Fe-rich smectite is ubiquitous in soil environments and closely linked to the fate and mobility of hazardous trace metals and particularly to the variations in the biogeochemical redox reactions of structural Fe that determine the sorption and desorption properties of clay minerals. The biotic/abiotic redox reactions of a Fe-rich smectite, nontronite (NAu-1), were performed at various reaction times using the Fe-reducing bacterium Shewanella oneidensis MR-1 at 30°C and Na-dithionite (Na2S2O4), respectively. The extent of biotic Fe-reduction of NAu-1 after 30 days of incubation reached up to 10.7% of total Fe and the range of abiotic Fe-reduction varied from 4.9–46.6% at reaction times of 5 min, 30 min, 1 h, and 4 h. The biotically and abiotically Fe-reduced NAu-1 samples were spiked with Pb concentrations of 0.07, 0.2, 0.5, and 1.0 mg/kg and incubated under aerobic or anaerobic conditions for 24 h.

The amounts of Pb in the supernatants were analyzed using an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) and Multi-collector (MC)-ICP-MS. The amounts of Pb removed from the supernatants were negatively related to the extent of Fe(III) reduction in the abiotically Fe-reduced NAu-1 samples. In contrast, less Pb (~15%) was removed from the biotically Fe-reduced NAu-1 samples with a similar extent of Fe(III) reduction. Changes in the isotopic 208/204Pb ratio indicated that the lighter 204Pb isotope was preferentially adsorbed to the NAu-1 samples with less Fe reduction and indicated that variations in the net layer charge affected isotopic fractionation. Significant differences in the 208/204Pb ratios for NAu-1 samples that were biotically Fe-reduced under anaerobic conditions were measured and indicate that the reversibility of the structural/chemical modifications that occur under redox conditions can affect Pb removal and, thus, isotope fractionation. These results collectively infer that the biogeochemical properties of clay minerals should be considered in order to understand the fate of trace metals in natural environments.

Mineralization of microbial biomass is a common phenomenon in geothermal habitats, but knowledge of the structure of the minerals formed in these environments is limited. A combination of spectroscopic, microscopic, and stable isotopic methods, as well as the chemical analysis of spring water, were employed in the present study to characterize calcium carbonate minerals deposited in filamentous cyanobacterial mats in different locations of La Duke hot spring, a circumneutral thermal feature near the north entrance of Yellowstone National Park, Montana, USA. Calcite was the primary crystalline mineral phase associated with biofilm-containing deposits closest to the source of the spring and the suspended microbial biomass in a pool further from the source. The carbonate minerals at all sites occurred as aggregated granules, ~2 μm in diameter, in close association with the microbial biomass. Only in the deposits closest to the source were the granules organized as laminated structures interspersed with microbial biomass. The calcium carbonate grains contained two distinct regions: a dense monolithic calcite core and a porous dendritic periphery containing organic matter (OM). Electron energy loss spectroscopy (EELS) indicated that the voids were infilled with OM and carbonates. The EELS technique was employed to distinguish the source of carbon in the organic matter and carbonate mixture. The studies of carbon isotope compositions of the calcium carbonates and the saturation indices for calcite in the spring waters suggest that processes (abiotic vs. biotic) controlling the carbonate formation may vary among the sampling sites.

This study was performed to improve production efficiency at the level of recipient pig and donor nuclei of transgenic cloned pigs used for xenotransplantation. To generate transgenic pigs, human endothelial protein C receptor (hEPCR) and human thrombomodulin (hTM) genes were introduced using the F2A expression vector into GalT–/–/hCD55+ porcine neonatal ear fibroblasts used as donor cells and cloned embryos were transferred to the sows and gilts. Cloned fetal kidney cells were also used as donor cells for recloning to increase production efficiency. Pregnancy and parturition rates after embryo transfer and preimplantation developmental competence were compared between cloned embryos derived from adult and fetal cells. Significantly higher parturition rates were shown in the group of sows (50.0 vs. 4.1%), natural oestrus (20.8 vs. 0%), and ovulated ovary (16.7 vs. 5.6%) compared with gilt, induced and non-ovulated, respectively (P < 0.05). When using gilts as recipients, final parturitions occurred in only the fetal cell groups and significantly higher blastocyst rates (15.1% vs. 21.3%) were seen (P < 0.05). Additionally, gene expression levels related to pluripotency were significantly higher in the fetal cell group (P < 0.05). In conclusion, sows can be recommended as recipients due to their higher efficiency in the generation of transgenic cloned pigs and cloned fetal cells also can be recommended as donor cells through correct nuclear reprogramming.

This study compares the investigated water vapor diffusion coefficient in the neat polyurethane (PU) membrane, the silica–PU nanocomposite membrane, and two surface-modified silica–PU nanocomposite membranes. The silane first surface modifier is with an amine functional group known as N-[3-(trimethoxysilyl)propyl]ethylenediamine, while the second one is with an aniline functional group known as N-[3-(trimethoxysilyl)propyl]aniline. The enhancement of water vapor diffusivity values through the polymer nanocomposite is desirable for the membrane air dehumidification application. The diffusivities were calculated via molecular dynamics simulations at the temperature of 298.15 K. The Einstein's relationship known as the mean square displacement method was used to obtain the diffusivity for the membranes. The results showed a significant effect on the diffusivity of water vapor for the surface-modified silica–PU nanocomposite membrane as compared with the neat PU and the unmodified silica–PU nanocomposite membranes. For the amine-modified silica, the diffusion coefficient increased by 80.3% compared with the unmodified silica–PU nanocomposite membrane. On the other hand, the aniline-modified silica outperformed the amine-modified one in terms of the diffusion coefficient by 22.4%.

We have investigated interfacial thermal resistance (ITR) between single-layer graphene and Cu substrate by using both experimental and numerical methods. For experiments, the micropipette sensing technique was utilized to measure the thermal conductivity of suspended graphene and temperature profile of supported graphene on Cu film subjected to heating with a point source continuous wave laser. The thermal conductivity of suspended single-layer graphene was measured to be 3492 ± 453 W/m°C from measurements of temperature profile on the suspended graphene. This intrinsic graphene thermal conductivity and the finite element method integrated with a multi-parameter fitting technique were used to estimate ITR between graphene and Cu film. In the multi-parameter fitting technique, the simulated temperature profile is compared with experimentally measured temperature profile on the supported graphene surface and the best-fitted parameters including thermal interface resistance was obtained. The estimated interface thermal resistance between single graphene and Cu substrate is 2.3 × 10−7 m2 K/W and the difference between experiment and simulation result during multi-parameter fitting is 6.9%.

We examined whether hypotension in very low birth weight infants aged⩽1 week was associated with hospital morbidities and overall mortality. Further, we studied whether hypotension was associated with poor neurodevelopmental outcomes in these patients at the corrected age of 18 months. A total of 166 very low birth weight infants were studied during this period. Hospital outcomes and neurodevelopmental outcomes at the corrected age of 18 months were evaluated. Among the 166 very low birth weight infants, 95 patients (57.2%) experienced hypotension at⩽1 week and were associated with an increased incidence of morbidities and mortality. At the corrected age of 18 months, hypotension of the⩽1 week group had significantly lower scores in all three – cognitive, language, and motor – composites of the Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) screening tests. In addition, a multivariable logistic regression analysis showed that longer mechanical ventilation and periventricular leukomalacia were additionally associated with worse cognitive and language neurodevelopmental outcomes. Hypotension in very low birth weight infants within 1 week of life was associated with increased morbidities and overall mortality. It was also associated with an increased risk of cognitive and language outcomes.

The submarine channel-fill system of the Cambrian Spurs Formation exhibits unique metre-scale cycles of breccia and diamictite. The studied sections, Eureka Spurs, are located at the Mariner Glacier in the central-eastern part of northern Victoria Land, Antarctica. A facies analysis of the channel-fill deposit has led to the recognition of four main lithofacies: breccia, diamictite, thin-bedded sandstone and mudstone. The channel-fill deposit consists of two architectural elements: hollow-fill (HF) and sheet-like (SL) elements. The SL has wide convex-up geometry and consists solely of a very thick bed of diamictite, and is interpreted as a submarine channel lobe. The HF has a concave-up erosional base and flat upper surface. The HF consists of nine cyclic alternations of underlying breccia (cohesionless debris flow) and overlying diamictite (cohesive debris flow). The deposition of breccia is interpreted to have been controlled by repeated allogenic processes such as earthquakes. In contrast, the abrupt vertical transition from breccia to diamictite in each cycle is interpreted to have resulted from an autogenic, slope instability-related process. The interaction of the allogenic and autogenic factors recorded in the metre-scale unique cyclic deposits provides new criteria to interpret cycles of submarine debris flow.

Despite their importance in the formation and evolution of stellar clusters and galaxies, the formation of high-mass stars remains poorly understood. We recently started a systematic observational study of the 22 GHz water and 44 GHz class I methanol masers in high-mass star-forming regions as a four-year KaVA large program. Our sample consists of 87 high-mass young stellar objects (HM-YSOs) in various evolutionary phases, many of which are associated with two or more different maser species. The primary scientific goals are to measure the spatial distributions and 3-dimensional velocity fields of multiple maser species, and understand the dynamical evolution of HM-YSOs and their circumstellar structures, in conjunction with follow-up observations with JVN/EAVN (6.7 GHz class II methanol masers), VERA, and ALMA. In this paper we present details of our KaVA large program, including the first-year results and observing/data analysis plans for the second year and beyond.

We present the results of the linear polarisation observations of methanol masers at 44 and 95 GHz towards 39 massive star forming regions (Kang et al. 2016). These two lines are observed simultaneously with the 21-m Korean VLBI Network (KVN) telescope in single dish mode. About 60% of the observed showed fractional polarisation of a few percents at least at one of the two transition lines. We note that the linear polarisation of the 44 GHz methanol maser is first detected in this study including single dish and interferometer observations. We find the polarisation properties of these two lines are similar as expected, since they trace similar regions. As a follow-up study, we have carried out the VLBI polarisation observations toward some 44 GHz maser targets using the KVN telescope. We present preliminary VLBI polarisation results of G10.34-0.14, which show consistent polarisation properties in multiple epoch observations.

Technologies for detecting and analyzing a single molecule help us understand and engineer numerous phenomena observed in nature. Carbon nanotubes (CNTs) are highly efficient molecular conduits due to their atomically smooth surface. Because of their small diameters, comparable to the size of a single molecule, even a single blocking molecule can obstruct CNT fluidic channels. Analyzing these pore-blocking events in CNTs therefore enables single-molecule studies. The high-aspect ratios of CNT channels, which extend the time scale of transport, allow for studying molecular transport that is too fast to record in other systems. Both theoretical studies and ensemble experimental measurements have verified the enhanced flow of various ions and molecular species in CNTs. Experimental measurements of a single-CNT fluidic channel, however, have only recently begun, demonstrating the detection of individual DNA, polymer, and alkali-metal ions. This article reviews recent advances in single-nanotube fluidic channels with a focus on experimental measurements.

Two challenges exist in laser-assisted atom probe tomography (APT). First, a drastic decline in mass-resolving power is caused, not only by laser-induced thermal effects on the APT tips of bulk oxide materials, but also the associated asymmetric evaporation behavior; second, the field evaporation mechanisms of bulk oxide tips under laser illumination are still unclear due to the complex relations between laser pulse and oxide materials. In this study, both phenomena were investigated by depositing Ni- and Co-capping layers onto the bulk LaAlO3 tips, and using stepwise APT analysis with transmission electron microscopy (TEM) observation of the tip shapes. By employing the metallic capping, the heating at the surface of the oxide tips during APT analysis became more symmetrical, thereby enabling a high mass-resolving power in the mass spectrum. In addition, the stepwise microscopy technique visualized tip shape evolution during APT analysis, thereby accounting for evaporation sequences at the tip surface. The combination of “capping” and “stepwise APT with TEM,” is applicable to any nonconductors; it provides a direct observation of tip shape evolution, allows determination of the field evaporation strength of oxides, and facilitates understanding of the effects of ultrafast laser illumination on an oxide tip.