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As the electronics industry is integrating more and more new molecules to utilize them in logic circuits and memories to achieve ultra-high efficiency and device density, many organic structures emerged as promising candidates either in conjunction with or as an alternative to conventional semiconducting materials such as but not limited to silicon. Owing to rotaxane's mechanically interlocked molecular structure consisting of a dumbbell-shaped molecule threaded through a macrocycle, they could be excellent nanomachines in molecular switches and memory applications. As a nanomachine, the macrocycle of rotaxane can move reversibly between two stations along its axis under external stimuli, resulting in two stable molecular configurations known as "ON" and "OFF" states of the controllable switch with distinct resistance. There are excellent reports on rotaxane's structure, properties, and function relationship and its application to molecular electronics (Ogino

International audience; We present a comparison of atmospheric transport model (ATM) simulations for carbonyl sulfide (COS), within the framework of the atmospheric tracer transport model intercomparison project "TransCom-COS." Seven ATMs participated in the experiment and provided simulations of COS mixing ratios over the years 2010-2018, using state-of-the-art surface fluxes for various components of the COS budget: biospheric sink, oceanic source, sources from fire and industry. The main goal of TransCom-COS is to investigate the impact of the transport uncertainty and emission distribution in simulating the spatio-temporal variability of tropospheric COS mixing ratios. A control case with seasonal surface fluxes of COS was constructed. The results indicate that the COS mixing ratios are underestimated by at least 50 parts per trillion (ppt) in the tropics, pointing to a missing tropical source. In summer, the mixing ratios are overestimated by at least 50 ppt above 40°N, pointing to a likely missing sink in the high northern latitudes. Regarding the latitudinal profile, the model spread is greater than 60 ppt above 40°N in boreal summer. Regarding the seasonal amplitude, the model spread reaches 50 ppt at 6 out of 15 sites, compared to an observed seasonal amplitude of 100 ppt. All models simulated a too late minimum by at least 2-3 months at two high northern-latitude sites, likely owing to errors in the seasonal cycle in the ocean emissions. This study highlighted the shortcomings in the COS global budget that need to be resolved before using COS as a photosynthesis tracer. Plain Language Summary In this study, we evaluate the state-of-the-art fluxes for various components of the carbonyl sulfide (COS) budget: biospheric sink, oceanic source, sources from fire and industry. A control case with seasonal surface fluxes of COS was constructed. Seven atmospheric transport models provided simulations of COS mixing ratios. Then, the simulated mixing ratios were evaluated against atmospheric measurements at several surface sites. Results show that all models fail to capture the observed latitudinal distribution and that the model spread is small compared to the model-observation mismatch. In summer, the overestimated mixing ratios above 40°N point to a likely missing sink in the high northern latitudes. The underestimated mixing ratios in the tropics point to a missing tropical source. This study highlighted the shortcomings in the COS global budget that need to be resolved before using COS as a photosynthesis tracer. REMAUD ET AL.

A new special collection in AGU journals will present findings from the Second REgional Carbon Cycle Assessment and Processes (RECCAP2) study with a decade of data on greenhouse gas growth.

Additive manufacturing technologies are expected to disrupt the majority of the traditional way of manufacturing methods, particularly in the field of medical and healthcare. Bones and teeth are vital organs that are susceptible to various disorders due to environmental, traumatic, genetic factors and inherent malignant disorders. Most of the implants/prostheses normally used are cast and have a standard size and shape. Additive manufacturing has opened opportunities to replace these hard tissues with customized implants, prostheses or the whole additive manufactured organ itself while considering anatomical/structural parts and functional aspects of the body. It helps to visualize and mimic internal organs/models, pre-planning via simulation, anatomical demonstration, treatments and surgical teaching/training to technical staff by medical professionals. The current review covers additive manufacturing applications for the possible treatment of osteosarcoma, bone tumors, traumatic fracture, congenital anomalies, dental diseases, vertebral and cranial abnormalities, etc. from toe to head highlighting printing of long bones, short bones, cartilages, teeth and more based on the general classification of bones shape, that is, the external shape and size of different bones with some case studies. The article has also touched upon the additive manufacturing competitive edge over the conventional methods in terms of complexity, easiness, cost-effectiveness and reduced time. However, the internal structures have not been addressed so far in additive manufacturing which could be a new corner to enhance the properties of bones and teeth in the future.

As VLSI technology is shifting from microelectronics to nanoelectronics era, bi-stable [2]rotaxane emerges as a promising candidate for molecular electronics. A typical voltage-driven [2]rotaxane consists of a cyclobis-(paraquat-p-phenylene) macrocycle encircling a dumbbell shape molecular chain and moving between two stations on the chain: tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP). As a molecular switch, the macrocycle can move reversibly between two stations along its axis with appropriate driving voltage, resulting in two stable molecular conformational states with distinct high and low resistance. This makes it a well-suited candidate to represent binary states ("0" and "1") for digital electronics. In this work, we performed molecular simulation to investigate the switching mechanism of [2]rotaxane molecule. We used distance and angle variables to characterize the movement of the macrocycle along the chain, and compared the switching behavior of [2]rotaxane in water, ethanol, dimethyl ether and vacuum. The results show that the solvent environment plays an important role in the switching characteristics of [2]rotaxane molecule. The switching of [2]rotaxane is stable, controllable, reversible and repeatable. We also looked into potential failure mechanism of the [2]rotaxane, which could shed light on the fault model, testing and reliability enhancement of [2]rotaxane based molecular electronics. Our simulation results support that [2]rotaxane molecules possess potential to be used for molecular memory and logic applications.

The graphene nanoparticles incorporated in thin polystyrene film in different configurations, garner into unique phenomenon of self-assembly regulated by the self-organization of the thin polystyrene film. The polystyrene–graphene nanoparticles composite when spin-coated together to form a thin film over a substrate, was observed to self-assemble in a Voronoi tessellation of ribbon-like structure. The suppression of dewetting of thin polystyrene film at the stage, where the holes coalesce and grow to form Voronoi tessellation of polymeric ribbons, sways the path for the graphene nanoparticles to self-assemble and organize into a Voronoi tessellation-like pattern of graphene nanoparticles. In the second method, the graphene nanoparticles dispersed in solvent were casted over the instability based dewetting patterns formed on the surface of the thin polystyrene film. This method exclusively caused the graphene nanoparticles to arrange in a polygonal array of dots prompted by the dynamics and morphology of dewetting. The reversals of the dewetted patterns were observed in this process, because of the solvent evaporation and Marangoni flow. The graphene nanoparticles in the presence of solvent destruct and self-healed the dewetted holes formed on the surface of the pure polystyrene thin film.

COVID-19 induced restrictions resulted in a lowered fine aerosol particle and trace gas concentration across several urban places around the world, providing a natural opportunity to study effects of anthropogenic activities on emissions of air pollutants. Impact of sudden suspension of human activities on air pollution was analyzed by studying the change in satellite retrieved NO2 concentrations and top-down NOx emission over the urban and rural areas around Delhi. NO2 was chosen for being the most indicative of emission intensity due to its short lifetime of the order of a few hours in the planetary boundary layer. We present a robust temporal comparison of Ozone Monitoring Instrument (OMI) retrieved NO2 column density during the lockdown with the counterfactual baseline concentrations, extrapolated from the long-term trend and seasonal cycle components of NO2 using observations during 2015 to 2019. NO2 columns in the urban area of Delhi experienced an anomalous relative change ranging from 60.0% decline during the Phase 1 of lockdown (March 25-April 13, 2020) to 3.4% during the post-lockdown Phase 5. In contrast, we find no substantial reduction in NO2 concentrations over the rural areas. To clarify the quantitative impact of the lockdown measures, weekly top-down NOx emissions were estimated from TROPOspheric Monitoring Instrument (TROPOMI) retrieved NO2 by accounting for horizontal advection derived from the steady state continuity equation. NOx emissions from urban areas and power plants exhibited a mean decline of 72.19% and 53.4% respectively in Phase 1 compared to the pre-lockdown business-as-usual phase. Due to absence of confounding emission source activity during lockdown, emission estimates over urban areas and power-plants were validated with respective electricity generation reports and Google’s mobility reports. A higher anomaly in emission estimates suggests that comparison of only concentration change, without accounting for the dynamical and photochemical conditions, may mislead evaluation of lockdown impact. Our results are also useful for optimizing bottom-up emission inventories.

Graphene-based nanocomposites have been extensively employed to design biomimetic platforms epitomizing the structural and functional complexity of the tissue with increased robustness and physiological relevance. The adhesive and mechanical cues provided by such nanocomposite microenvironment kindles the cell fate decisions. Owing to their differentiation and regenerative potential, Human Mesenchymal Stem Cells (hMSCs) have proven to be a promising candidate for treating several neurodegenerative disorders. However, their degree of differentiation and its reproducibility is often jeopardized by multiple levels of heterogeneity, thereby compromising their translational utilization. Baffled at this crossroad, we designed a one-step approach to electrospin Poly-caprolactone (PCL) nanocomposite, with varying graphene concentrations, to capture, for the first time, the realms of their biocompatible and anisotropic characteristics, providing biomimetic platforms for improved differentiation of human bone marrow-derived MSCs (hMSCs) into neurons. Interestingly, PCL having 0.05% graphene (PCL-G0.05) showcased an ideal nano-topography with an unprecedented combination of guidance stimuli and substrates cues, aiding in enhanced differentiation of hMSCs into dopaminergic neurons (DA). These newly differentiated DA neurons were characterized at gene, protein, and functional levels and were seen to exhibit unique neuronal arborization, enhanced intracellular Ca2+ influx, and dopamine secretion, thereby opening new horizons for pre-clinical and clinical applications.

The 11th Symposium on Polar Science/Special session: [S] Accelerating Arctic research: Recent progress and future prospect of Arctic research, Poster presentations, Mon. 16 Nov. - Fri. 18 Dec.

The graphene quantum dot (GQD) is a carbon allotrope with a planar surface amenable for functionalization and nanoscale dimensions that confer photoluminescent properties. Collectively, these properties render GQDs an advantageous platform for nanobiotechnology applications, including as optical biosensors and delivery platforms. In particular, noncovalent functionalization offers a route to reversible modification and preservation of the pristine GQD substrate. However, a clear paradigm for GQD noncovalent functionalization has yet to be realized. Herein, we demonstrate the feasibility of noncovalent polymer adsorption to the GQD surface, with a specific focus on single-stranded DNA (ssDNA). We study how GQD oxidation level affects the propensity for polymer adsorption by synthesizing and characterizing four types of GQD substrates and investigating noncovalent polymer association to these substrates. Distinct adsorption methods are developed for successful ssDNA attachment based upon the GQD’s initial level of oxidation. ssDNA adsorption to the GQD is confirmed by atomic force microscopy, by inducing ssDNA desorption, and with molecular dynamics simulations. ssDNA is determined to adsorb strongly to no-oxidation GQDs, weakly to low-oxidation GQDs, and not at all for heavily oxidized GQDs. We hypothesize that high GQD oxygen content disrupts the graphitic carbon domains responsible for stacking with the aromatic ssDNA bases, thus preventing the formation of stable polymer-GQD complexes. Finally, we develop a more generic adsorption platform and assess how the GQD system is tunable by modifying both the polymer sequence and type.

It is one of the most important needs to develop renewable, scalable and multifunctional methods for the fabrication of 3D carbon architectures. Even though a lot of methods have been developed to create porous and mechanically stable 3D scaffolds, the fabrication and control over the synthesis of such architectures still remain a challenge. Here, we used Magnetospirillum magneticum (AMB-1) bacteria as a bio-template to fabricate light-weight 3D solid structure of carbon nanotubes (CNTs) with interconnected porosity. The resulting porous scaffold showed good mechanical stability and large surface area because of the excellent pore interconnection and high porosity. Steered molecular dynamics simulations were used to quantify the interactions between nanotubes and AMB-1 via the cell surface protein MSP-1 and flagellin. The 3D CNTs-AMB1 nanocomposite scaffold is further demonstrated as a potential substrate for electrodes in supercapacitor applications.

Rett syndrome (RTT), mainly caused by mutations in the methyl-CpG binding protein 2 (MeCP2), is one of the most prevalent intellectual disorders without effective therapeutics. Here, we used two-dimensional and three-dimensional human brain cultures to investigate MeCP2 function. We found that MeCP2 mutations cause severe abnormalities in human interneurons (INs). Surprisingly, the treatment with a BET inhibitor, JQ1, rescued the molecular and functional phenotypes of MeCP2 mutant INs. We uncovered that abnormal increases in the chromatin binding of BRD4 and the enhancer-promoter interactions underlie the abnormal transcription in MeCP2 mutant INs, which were recovered to normal levels by JQ1. We revealed the cell type-specific transcriptome impairment in MeCP2 mutant region-specific human brain organoids, which were rescued by JQ1. Finally, JQ1 ameliorated RTT-like phenotypes in mice. These data demonstrate BRD4 dysregulation is a critical driver for RTT etiology, and suggest targeting BRD4 could be a potential therapeutic opportunity for RTT.

Fundamental understanding of interactions at the interface of biological molecules, such as proteins, and nanomaterials is crucial for developing various biocompatible hybrid materials and biosensing platforms. Biosensors comprising of graphene-based conductive nanomaterials offer the advantage of higher sensitivity and reliable diagnosis mainly due to their superior specific surface area and ballistic conductivity. Furthermore, conductive nanocomposite structures that immobilize proteins can synergize the properties of both transducers and molecular recognition elements improving the performance of the biosensing device. Here we report for the first time, using a combined molecular dynamics simulations and experimental approach, the interactions between avidin and graphene for the development of a sensing platform that can be used for the detection of biological macromolecules such as mismatch repair proteins through biotinylated DNA substrates. We find that the interactive forces between avidin and graphene are mainly hydrophobic, along with some van der Waals, electrostatic and hydrogen bonding interactions. Notably, the structure and function of the avidin molecule are largely preserved after its adsorption on the graphene surface. The MD results agree well with scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS) analysis of avidin immobilized on a graphenated polypyrrole (G-PPy) conductive nanocomposite confirming the adsorption of avidin on graphene nanoplatelets as observed from the Fourier-transform infrared spectroscopy (FTIR).

The counter electrode (CE), despite being as relevant as the photoanode in a quantum dot solar cell (QDSC), has hardly received the scientific attention it deserves. In this study, nine CEs (single-walled carbon nanotubes (SWCNTs), tungsten oxide (WO3), poly(3,4-ethylenedioxythiophene) (PEDOT), copper sulfide (Cu2S), candle soot, functionalized multiwalled carbon nanotubes (F-MWCNTs), reduced tungsten oxide (WO3–x), carbon fabric (C-Fabric), and C-Fabric/WO3–x) were prepared by using low-cost components and facile procedures. QDSCs were fabricated with a TiO2/CdS film which served as a common photoanode for all CEs. The power conversion efficiencies (PCEs) were 2.02, 2.1, 2.79, 2.88, 2.95, 3.78, 3.66, 3.96, and 4.6%, respectively, and the incident photon to current conversion efficiency response was also found to complement the PCE response. Among all CEs employed here, C-Fabric/WO3–x outperforms all the other CEs, for the synergy between C-Fabric and WO3–x comes to the fore during cell operation. The low...

Advances in nanotechnology has become enormously promising in the field of health science, in developing many medical equipment. The possible effects of novel nanomedical technology significantly improve the diagnosis and therapeutic aspects of many diseases. Nanomaterials are being applied in operation, disease diagnosis as well as therapy, molecular imaging, implant technology, tissue engineering, as well as a device for efficient drug delivery, protein and gene release. In this review we discussed the utility of nanoscience in health issues, and the knowledge from there how can be disseminated to the educators and parents for expanding STEM (Science, Technology, Engineering and Math) programs.

Additional file 1: Figure S1. Detail of the masks used for space averaging and construction of the error covariance matrix. Upper row: rural, urban and sea domains. Lower row: areas corresponding to EDGAR grid cells with flux higher than 1 mg m−2 s−1 (left panel) and 0.1 mg m−2 s−1 (center panel), for reference. Right panel shows the inner domain used when averaging over all areas.

Human cortical organoids (hCOs), derived from human embryonic stem cells (hESCs), provide an excellent platform to study human brain development and diseases in complex 3D tissue. However, current hCOs lack microvasculature, resulting in limited oxygen and nutrient delivery to the inner-most parts of hCOs. Here, we engineered hESCs to ectopically express human ETS variant 2 (hETV2) to create in vitro vasculature in hCOs, namely vhCOs (vascularized hCOs). hETV2-expressing cells in hCOs contributed to forming a complex vascular-like network in hCOs. Importantly, the presence of vascularization resulted in enhanced functional maturation of organoids. We found that vhCOs acquired several blood-brain barrier (BBB) characteristics, including an increase in the expression of tight junctions, nutrient transporters, and trans-endothelial electrical resistance. Finally, hETV2-induced endothelium supported the formation of perfused blood vessels in vivo. These vhCOs form vasculature that resemble the early prenatal brain, and present a robust model to study brain disease in vitro.

Background In order to use in situ measurements to constrain urban anthropogenic emissions of carbon dioxide (CO2), we use a Lagrangian methodology based on diffusive backward trajectory tracer reconstructions and Bayesian inversion. The observations of atmospheric CO2 were collected within the Tokyo Bay Area during the Comprehensive Observation Network for TRace gases by AIrLiner (CONTRAIL) flights, from the Tsukuba tall tower of the Meteorological Research Institute (MRI) of the Japan Meteorological Agency and at two surface sites (Dodaira and Kisai) from the World Data Center for Greenhouse Gases (WDCGG). Results We produce gridded estimates of the CO2 emissions and calculate the averages for different areas within the Kanto plain where Tokyo is located. Using these inversions as reference we investigate the impact of perturbing different elements in the inversion system. We modified the observations amount and location (surface only sparse vs. including aircraft CO2 observations), the background representation, the wind data used to drive the transport model, the prior emissions magnitude and time resolution and error parameters of the inverse model. Conclusions Optimized fluxes were consistent with other estimates for the unperturbed simulations. Inclusion of CONTRAIL measurements resulted in significant differences in the magnitude of the retrieved fluxes, 13% on average for the whole domain and of up to 21% for the spatiotemporal cells with the highest fluxes. Changes in the background yielded differences in the retrieved fluxes of up to 50% and more. Simulated biases in the modelled transport cause differences in the retrieved fluxes of up to 30% similar to those obtained using different meteorological winds to advect the Lagrangian trajectories. Perturbations to the prior inventory can impact the fluxes by ~ 10% or more depending on the assumptions on the error covariances. All of these factors can cause significant differences in the estimated flux, and highlight the challenges in estimating regional CO2 fluxes from atmospheric observations. Electronic supplementary material The online version of this article (10.1186/s13021-019-0118-8) contains supplementary material, which is available to authorized users.

Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere – the “global carbon budget” – is important to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe data sets and methodology to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFF) are based on energy statistics and cement production data, while emissions from land use and land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) and terrestrial CO2 sink (SLAND) are estimated with global process models constrained by observations. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the last decade available (2008–2017), EFF was 9.4±0.5 GtC yr−1, ELUC 1.5±0.7 GtC yr−1, GATM 4.7±0.02 GtC yr−1, SOCEAN 2.4±0.5 GtC yr−1, and SLAND 3.2±0.8 GtC yr−1, with a budget imbalance BIM of 0.5 GtC yr−1 indicating overestimated emissions and/or underestimated sinks. For the year 2017 alone, the growth in EFF was about 1.6 % and emissions increased to 9.9±0.5 GtC yr−1. Also for 2017, ELUC was 1.4±0.7 GtC yr−1, GATM was 4.6±0.2 GtC yr−1, SOCEAN was 2.5±0.5 GtC yr−1, and SLAND was 3.8±0.8 GtC yr−1, with a BIM of 0.3 GtC. The global atmospheric CO2 concentration reached 405.0±0.1 ppm averaged over 2017. For 2018, preliminary data for the first 6–9 months indicate a renewed growth in EFF of +2.7 % (range of 1.8 % to 3.7 %) based on national emission projections for China, the US, the EU, and India and projections of gross domestic product corrected for recent changes in the carbon intensity of the economy for the rest of the world. The analysis presented here shows that the mean and trend in the five components of the global carbon budget are consistently estimated over the period of 1959–2017, but discrepancies of up to 1 GtC yr−1 persist for the representation of semi-decadal variability in CO2 fluxes. A detailed comparison among individual estimates and the introduction of a broad range of observations show (1) no consensus in the mean and trend in land-use change emissions, (2) a persistent low agreement among the different methods on the magnitude of the land CO2 flux in the northern extra-tropics, and (3) an apparent underestimation of the CO2 variability by ocean models, originating outside the tropics. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding the global carbon cycle compared with previous publications of this data set (Le Quéré et al., 2018, 2016, 2015a, b, 2014, 2013). All results presented here can be downloaded from https://doi.org/10.18160/GCP-2018.

During a heart failure, an increased content and activity of nucleoside diphosphate kinase (NDPK) in the sarcolemmal membrane is responsible for suppressing the formation of the second messenger cyclic adenosine monophosphate (cAMP)—a key component required for calcium ion homeostasis for the proper systolic and diastolic functions. Typically, this increased NDPK content lets the surplus NDPK react with a mutated G protein in the beta-adrenergic signal transduction pathway, thereby inhibiting cAMP synthesis. Thus, it is thus that inhibition of NDPK may cause a substantial increase in adenylate cyclase activity, which in turn may be a potential therapy for end-stage heart failure patients. However, there is little information available about the molecular events at the interface of NDPK and any prospective molecule that may potentially influence its reactive site (His118). Here we report a novel computational approach for understanding the interactions between graphene oxide (GO) and NDPK. Using molecular dynamics, it is found that GO interacts favorably with the His118 residue of NDPK to potentially prevent its binding with adenosine triphosphate (ATP), which otherwise would trigger the phosphorylation of the mutated G protein. Therefore, this will result in an increase in cAMP levels during heart failure.

This paper presents the first results of an age of air (AoA) inter-comparison of six global transport models. Following a protocol, three global circulation models and three chemistry transport models simulated five tracers with boundary conditions that grow linearly in time. This allows for an evaluation of the AoA and transport times associated with inter-hemispheric transport, vertical mixing in the troposphere, transport to and in the stratosphere, and transport of air masses between land and ocean. Since AoA is not a directly measurable quantity in the atmosphere, simulations of 222Rn and SF6 were also requested. We focus this first analysis on averages over the period 2000–2010, taken from longer simulations covering the 1988–2014 period. We find that two models, NIES and TOMCAT, show substantially slower vertical mixing in the troposphere compared to other models (LMDZ, TM5, EMAC, and ACTM). However, while the TOMCAT model, as used here, has slow transport between the hemispheres and between land and ocean, the NIES model shows efficient horizontal mixing and a smaller latitudinal gradient in SF6 compared to the other models and observations. We find consistent differences between models concerning vertical mixing of the troposphere, expressed as AoA differences and modeled 222Rn gradients between 950 and 500 hPa. All models agree, however, on an interesting asymmetry in inter-hemispheric mixing, with faster transport from the Northern hemisphere surface to the Southern hemisphere than vice versa. This is attributed to a rectifier caused by a stronger seasonal cycle in boundary layer venting over Northern hemispheric landmasses, and possibly to a related asymmetric position of the inter-tropical convergence zone. The calculated AoA in the upper stratosphere varies considerably among the models (4–7 years). Finally, we find that the inter-model differences are generally larger than differences in AoA that result from using the same model with a different resolution or convective parameterisation. Taken together, the AoA model inter-comparison provides a useful addition to traditional approaches to evaluate transport time scales. Results highlight that inter-model differences associated with resolved transport (advection) and parameterised transport (convection, boundary layer mixing) are still large, and require further analysis. For this purpose, all model output and analysis software is available.

Vaccination is a safe and effective approach to prevent deadly diseases. To increase vaccine production, we propose that a mechanical stimulation can enhance protein production. In order to prove this hypothesis, Sf9 insect cells were used to evaluate the increase in the expression of a fusion protein from hepatitis B virus (HBV S1/S2). We discovered that the ultrasound stimulation at a frequency of 1.5 MHz, intensity of 60 mW/cm2, for a duration of 10 minutes per day increased HBV S1/S2 by 27%. We further derived a model for transport through a cell membrane under the effect of ultrasound waves, tested the key assumptions of the model through a molecular dynamics simulation package, NAMD (Nanoscale Molecular Dynamics program) and utilized CHARMM force field in a steered molecular dynamics environment. The results show that ultrasound waves can increase cell permeability, which, in turn, can enhance nutrient / waste exchange thus leading to enhanced vaccine production. This finding is very meaningful in either shortening vaccine production time, or increasing the yield of proteins for use as vaccines.

A potential ion-exchange material was developed from poly(acrylonitrile) fibers that were prepared by electrospinning followed by alkaline hydrolysis (to convert the nitrile group to the carboxylate functional group). Characterization studies performed on this material using X-ray photoelectron spectroscopy, scanning electron microscopy, Fourier-Transform infra-red spectroscopy, and ion chromatography confirmed the presence of ion-exchange functional group (carboxylate). Optimum hydrolysis conditions resulted in an ion-exchange capacity of 2.39 meq/g. Ion-exchange fibers were used in a packed-bed column to selectively remove heavy-metal cation from the background of a benign, competing cation at a much higher concentration. The material can be efficiently regenerated and used for multiple cycles of exhaustion and regeneration.

Zinc finger nucleases (ZFNs) are associated with cell death and apoptosis by binding at countless undesired locations. This cytotoxicity is associated with the binding ability of engineered zinc finger domains to bind dissimilar DNA sequences with high affinity. In general, binding preferences of transcription factors are associated with significant degenerated diversity and complexity which convolutes the design and engineering of precise DNA binding domains. Evolutionary success of natural zinc finger proteins, however, evinces that nature created specific evolutionary traits and strategies, such as modularity and rank-specific recognition to cope with binding complexity that are critical for creating clinical viable tools to precisely modify the human genome. Our findings indicate preservation of general modularity and significant alteration of the rank-specific binding preferences of the three-finger binding domain of transcription factor SP1 when exchanging amino acids in the 2nd finger.

A living entity can be described as a complex adaptive system which differs from any, however complex, chemical structure by its capability of functional self-organization based on the processing of information. If one asks, where does this information come from and what is its primary semantics, the answer is: information generates itself in feedback loops via replication and selection, the objective being 'to be or not to be'. This paper describes the theoretical framework of information-generating systems and provides experimental clues for some basic forms of genetic organization, such as molecular quasi-species, hypercyclic and compartmentalized RNA-protein assemblies. The results are primarily obtained with RNA viruses and virus-like systems. The experiments are carried out with the help of automated, computer-controlled bioreactors, called 'evolution machines', that may form the basis of a new 'evolutionary biotechnology'.

A novel design of a laboratory built axially rotating collector (ARC) having capability to align electrospun nanofibers have been described. A detailed morphological comparison of such nanofibers orientation and their geometry is done using scanning electron microscopy (SEM). For comparison various polymeric solutions were electrospun on conventional static collector as well as ARC. The average diameter of polyvinyl alcohol (PVA) nanofibers was found to be 250 nm while polycaprolactone (PCL) nanofibers were found to be within a range of 600-800 nm. Conducting nanoparticles such as graphene and multi-walled carbon nanotubes (MWNTs) mixed with polymer solutions shown to have a significant influence on the overall geometry of these nanofibers and their diameter distribution. It is evident from the SEM analysis that both graphene and MWNTs in polymer solution play a crucial role in achieving a uniform diameter of nanofibers. Lastly, the formation of the aligned nanofibers using ARC has been mathematically modeled and the electromagnetic field governing the process has been simulated.

The aim of this paper is to present an overview of inverse modeling methods that have been developed over the years for estimating the global sources and sinks of CH4. It provides insight into how techniques and estimates have evolved over time, and what the remaining shortcomings are. As such, it serves a didactical purpose of introducing apprentices to the field, but it also takes stock of the developments so far and reflects on promising new directions. The main focus is on methodological aspects that are particularly relevant for CH4, such as its atmospheric oxidation, the use of methane isotopologues, and specific challenges in atmospheric transport modeling of CH4. The use of satellite retrievals receives special attention, as it is an active field of methodological development, with special requirements on the sampling of the model and the treatment of data uncertainty. Regional scale flux estimation and attribution is still a grand challenge, which calls for new methods capable of combining information from multiple data streams of different measured parameters. A process model representation of sources and sinks in atmospheric transport inversion schemes allows the integrated use of such data. These new developments are needed not only to improve our understanding of the main processes driving the observed global trend, but also to support international efforts to reduce greenhouse gas emissions.

Human brain organoid techniques have rapidly advanced to facilitate investigating human brain development and diseases. These efforts have largely focused on generating telencephalon due to its direct relevance in a variety of forebrain disorders. Despite its importance as a relay hub between cortex and peripheral tissues, the investigation of three-dimensional (3D) organoid models for the human thalamus has not yet been explored. Here, we describe a method to differentiate human embryonic stem cells (hESCs) to thalamic organoids (hThOs) that specifically recapitulate the development of thalamus. Single-cell RNA sequencing revealed a formation of distinct thalamic lineages, which diverge from telencephalic fate. Importantly, we developed a 3D system to create the reciprocal projections between thalamus and cortex by fusing the two distinct region-specific organoids representing the developing thalamus or cortex. Our study provides a platform for understanding human thalamic development and modeling circuit organizations and related disorders in the brain.

Flame-retardant properties of nylon 6/organically modified montmorillonite (OMMT) thin films, fibers, and fabrics were investigated to determine the efficacy of condensed-phase flame-retardant mechanism in relation to montmorillonite concentration, sample geometry, and flame test conditions. Horizontal flame spread conducted on thin films revealed no significant difference in burning behavior between nylon 6 and nanocomposites with 5 wt% OMMT. However, with a higher concentration level of 8–10 wt% OMMT, the films burned without any dripping. The flame spread rate was reduced by 30–40% as compared with nylon 6 films. Cone calorimeter study on nanocomposite films showed that the peak heat release rate of nylon 6 was reduced by 65–67% with 8–10 wt% OMMT. Undrawn nanocomposite monofilaments with 10 wt% OMMT burned slowly and steadily in Bunsen flame without dripping. In cone calorimeter, nanocomposite fabrics with 8 wt% OMMT showed reduced heat release rate and mass loss rate compared to nylon 6 fabrics with increase in fabric tightness factor. The mass loss rate was about 40–60% less when compared with nylon 6 fabrics. The fabric char structure remained intact after burning. This demonstrated the interdependence of fabric tightness factor, OMMT concentration, and source of heat flux in forming a protective char and affecting the flammability of fabrics. POLYM. ENG. SCI., 2008. © 2008 Society of Plastics Engineers

第6回極域科学シンポジウム分野横断セッション：[IA] 急変する北極気候システム及びその全球的な影響の総合的解明―GRENE北極気候変動研究事業研究成果報告2015―11月19日（木） 国立極地研究所１階交流アトリウム

Supercapacitors also known as electrochemical capacitors, that store energy via either Faradaic or non-Faradaic processes, have recently grown popularity mainly because they complement and can even replace, conventional energy storage systems in variety of applications. Supercapacitor performance can be improved significantly by developing new nanocomposite electrodes which utilizes both the energy storage processes simultaneously. Here we report, fabrication of the freestanding hybrid electrodes, by incorporating graphene and carbon nanotubes (CNT) in pyrrole monomer via its in-situ polymerization. At the scan rate of 5 mV s−1, the specific capacitance of the polypyrrole-CNT-graphene (PCG) electrode film was 453 F g−1 with ultrahigh energy and power density of 62.96 W h kg−1 and 566.66 W kg−1 respectively, as shown in the Ragone plot. A nanofibrous membrane was electrospun and effectively used as a separator in the supercapacitor. Four supercapacitors were assembled in series to demonstrate the device performance by lighting a 2.2 V LED.

Generating renewable energy while sequestering CO2 using algae has recently attracted significant research attention, mostly directing towards biological methods such as systems biology, genetic engineering and bio-refining for optimizing algae strains. Other approaches focus on chemical screening to adjust culture conditions or culture media. We report for the first time the physiological changes of algal cells in response to a novel form of mechanical stimulation, or a pulsed wave at the frequency of 1.5 MHz and the duty cycle of 20%. We studied how the pulsed wave can further increase algal lipid production on top of existing biological and chemical methods. Two commonly used algal strains, fresh-water Chlorella vulgaris and seawater Tetraselmis chuii, were selected. We have performed the tests in shake flasks and 1 L spinner-flask bioreactors. Conventional Gravimetric measurements show that up to 20% increase for algal lipid could be achieved after 8 days of stimulation. The total electricity cost needed for the stimulations in a one-liter bioreactor is only one-tenth of a US penny. Gas liquid chromatography shows that the fatty acid composition remains unchanged after pulsed-wave stimulation. Scanning electron microscope results also suggest that pulsed wave stimulation induces shear stress and thus increases algal lipid production.

Over the years, many designs for biobandage were introduced for different types of burns but in most cases these designs are introduced as a protection means to cover and protect the burned tissue from the bacterial infection not as a treatment means. In this paper a new model for a burns biobandage is introduced not only as a protective mean but also as a treatment technique by helping the tissue to rebuild itself as fast as possible. The main objective of this research is to develop a simple cryotherapeutic system to absorb the large amount of heat produced by the burned tissue and reducing its temperature in order to facilitate the tissue healing and regeneration process. A biobandage is proposed to include an iced layer as a cooling source, a cotton layer and a water gel layer for comfort and temperature control, and a plastic layer to seal the ice layer. The combination of these four layers physically work together to reduce inflammation, which in turn make the heeling or recovery time shorter and reduce pain as a result of decreasing the nerve conductivity. The COMSOL Multiphysics was used to model the cooling process on burned tissue using the proposed iced-biobandage. The calculated temperature profiles along the depth biobandage and burned skin provide a clear visualizing of the heat flow within each layer. The history of temperature and heat transfer rate at the burned skin surface are monitored for an effective cooling and healing process. A modeling analysis was performed to examine the changes of temperature over a predetermined time and to help in identifying the optimal period for ice cooling process, the analysis shows that the ice layer is effective within a certain period of time and after this period it doesn't add any beneficial effect.

Over the past forty years, significant research has been done on story/narrative generation in which the computer is the author. Many existing systems generate stories by filling in a template or copying an analogous story (and changing the time, place, etc.) or by prompting the user to provide a start to the story. Very few systems generate variable stories without these techniques. While it is impossible to quantify a human writer's inspiration, we can consider a common exercise that authors perform; namely ‘writing prompts’. A writing prompt is just a topic or idea around which to start writing. The prompt can simply be a few words, which becomes the basis for a story. In this paper we present story generation from the perspective of how human authors create stories via writing prompts. The system will select a few random words as a prompt, which will form the basic parameters for generating a story. But unlike a human writer, a computer cannot intuitively know the context of a chosen word. Therefore, the Internet (and existing ‘Concept Knowledge’ systems) will be used to find the context for the selected words, thus guiding the story generation process.

Biological tissues have the remarkable ability to remodel and repair in response to disease, injury and mechanical stresses. Synthetic materials lack the complexity of biological tissues, and man-made materials that respond to external stresses through a permanent increase in stiffness are uncommon. Here we report that polydomain nematic liquid crystal elastomers increase in stiffness by up to 90% when subjected to a low-amplitude (5%), repetitive (dynamic) compression. Elastomer stiffening is influenced by liquid crystal content, the presence of a nematic liquid crystal phase and the use of a dynamic as opposed to static deformation. Through rheological and X-ray diffraction measurements, stiffening can be attributed to a mobile nematic director, which rotates in response to dynamic compression. Stiffening under dynamic compression has not been previously observed in liquid crystal elastomers and may be useful for the development of self-healing materials or for the development of biocompatible, adaptive materials for tissue replacement.

Classical experiments show that the force required to slide liquid drops on surfaces increases with the resting time of the drop, t(rest), and reaches a plateau typically after several minutes. Here we use the centrifugal adhesion balance to show that the lateral force required to slide a water drop on a graphene surface is practically invariant with t(rest). In addition, the drop's three-phase contact line adopts a peculiar micrometric serrated form. These observations agree well with current theories that relate the time effect to deformation and molecular re-orientation of the substrate surface. Such molecular re-orientation is non-existent on graphene, which is chemically homogenous. Hence, graphene appears to provide a unique tribological surface test bed for a variety of liquid drop-surface interactions.