bluuebunny/crossref_metadata_2025 huggingface dataset:
Solar Wind Interaction With the Martian Upper Atmosphere: Roles of the Cold Thermosphere and Hot Oxygen Corona
Authors: Dong Chuanfei , Bougher Stephen W. , Ma Yingjuan , Lee Yuni , Toth Gabor , Nagy Andrew F. , Fang Xiaohua , Luhmann Janet , Liemohn Michael W. , Halekas Jasper S. , Tenishev Valeriy , Pawlowski David J. , Combi Michael R.
Published: June 2018

We study roles of the thermosphere and exosphere on the Martian ionospheric structure and ion escape rates in the process of the solar wind‐Mars interaction. We employ a four‐species multifluid magnetohydrodynamic model to simulate the Martian ionosphere and magnetosphere. Thecoldthermosphere background is taken from the Mars Global Ionosphere Thermosphere Model, and the hot oxygen exosphere is adopted from the Mars exosphere Monte Carlo model—Adaptive Mesh Particle Simulator. A total of four cases with the combination of 1‐D (globally averaged) and 3‐D thermospheres and exospheres are studied. The ion escape rates calculated by adopting 1‐D and 3‐D atmospheres are similar; however, the latter are required to adequately reproduce the ionospheric observations by the Mars Atmosphere and Volatile EvolutioN mission. In addition, our simulations show that the 3‐D hot oxygen corona plays an important role in preventing planetary molecular ions (Oand CO) escaping from Mars, mainly resulting from the mass loading of the high‐altitude exospheric O+ions. Thecoldthermospheric oxygen atom, however, is demonstrated to be the primary neutral source for O+ion escape during the relatively weak solar cycle 24.
The Improved Two‐Dimensional Artificial Neural Network‐Based Ionospheric Model (ANNIM)
Authors: Tulasi Ram S. , Sai Gowtam V. , Mitra Arka , Reinisch B.
Published: June 2018

An artificial neural network‐based two‐dimensional ionospheric model (ANNIM) that can predict the ionospheric F2‐layer peak density (NmF2) and altitude (hmF2) had recently been developed using long‐term data of Formosat‐3/COSMIC GPS radio occultation (RO) observations (Sai Gowtam & Tulasi Ram, 2017a, https://doi.org/10.1002/2017JA024795). In this current paper, we present an improved version of ANNIM that was developed by assimilating additional ionospheric data from CHAMP, GRACE RO, worldwide ground‐based Digisonde observations, and by using a modified spatial gridding approach based on the magnetic dip latitudes. The improved ANNIM better reproduces the spatial and temporal variations of NmF2 and hmF2, including the postsunset enhancement in equatorial hmF2 associated with the prereversal enhancement in the zonal electric field. The ANNIM‐predicted NmF2 and hmF2 exhibit excellent correlations with ground‐based Digisonde observations over different solar activity periods. The ANNIM simulations under enhanced geomagnetic activity predict the depletion of NmF2 at auroral‐high latitudes, and enhancement over low latitude to midlatitude with respect to quiet conditions, which is consistent with the storm time meridional wind circulation and the associated neutral composition changes. The improved ANNIM also predicts a significant enhancement in hmF2 around auroral latitudes due to increased plasma scale height associated with particle and Joule heating during storm periods. Further, the ANNIM successfully reproduces the coherent oscillations in NmF2 and hmF2 with recurrent cororating interaction region‐driven geomagnetic activity during the extreme solar minimum year 2008 and can distinguish the roles of recurrent geomagnetic activity and solar irradiance through controlled simulations.
A Quick Look Method to Assess the Dependencies of Rock Physical Sediment Properties on the Saturation With Pore‐Filling Hydrate
Authors: Spangenberg Erik , Seyberth Karl , Heeschen Katja U. , Priegnitz Mike , Schicks Judith M.
Published: June 2018

Within the framework of the national German hydrate project Submarine Gas Hydrate Reservoirs (SUGAR) we promised to deliver dependencies of compressional‐wave velocity and electrical resistivity on hydrate saturation within sand sediments of the paleo Danube channel‐levee system in the Black Sea. These data supported starting models for joint inversion of seismic and electromagnetic geophysics data for that area. Because hydrate formation in sediment samples under laboratory conditions is a complex and particularly time‐consuming procedure, we developed a quick look experimental methodology. We used ice as an analogue for methane hydrate to simplify the experimental procedure for laboratory studies. The difference from existing approaches is the way the ice and water saturation of the porous sediment is determined. To verify this approach, we compared the new data measured on ice‐bearing sand with measurements on hydrate‐bearing sediments, where methane hydrate was produced from methane dissolved in water. The main result from this study is that ice forming from a salt solution in the pore space of sand forms like methane hydrate as a noncementing solid pore fill. The method does not require a pore pressure system and produces a homogeneous ice distribution, as long as homogeneous temperature distribution throughout the sample can be guaranteed. For compressional‐wave velocity measurements we demonstrate that ice can be used as an analogue for noncementing methane hydrate. Therefore, the complete dependence of velocity on ice saturation, depending on the saturation increment, can easily be measured in 1 to 2 weeks.
Earthquake Lights: Mechanism of Electrical Coupling of Earth's Crust to the Lower Atmosphere
Authors: Jánský Jaroslav , Pasko Victor P.
Published: June 2018

Earthquake lights are an atmospheric luminous phenomenon occurring before, during, and occasionally after earthquakes. In the present work we assume that strong electric currents are produced inside the Earth during earthquakes and model the current and field distribution inside and above the Earth to find the conditions where electrical discharges can appear. The simulation results quantify the effects of various configurations of current dipoles inside the Earth. The results are supported by approximate formulations allowing effective solution of the same problems using an analytical theory. It is shown that a large‐scale dipole with poles located in Earth's crust at 5 and 15 km beneath the Earth's surface requires energy significantly higher than the total seismic wave energy in major earthquakes. The more likely setup to produce earthquake lights is found to be when the upper pole of the source current dipole is shifted close to the Earth's surface, in particular, when locations of current dipoles are tens of meters beneath Earth's surface.
Near infrared fluorescent peptide nanoparticles for enhancing esophageal cancer therapeutic efficacy
Authors: Fan Zhen , Chang Yan , Cui Chaochu , Sun Leming , Wang David H. , Pan Zui , Zhang Mingjun
Published: June 2018

Various types of nanoparticles have been proposed for targeted drug delivering, imaging, and tracking of therapeutic agents. However, highly biocompatible nanoparticles with structure-induced fluorescence and capability to conjugate with biomarkers and drugs remain lacking. This research proposes and synthesizes fluorescent nanoparticles (f-PNPs) assembled by cyclic peptides to combine imaging and drug delivering for esophageal cancer (EC). To achieve tumor targeting, f-PNPs are first conjugated with RGD moieties to selectively target EC cells via αvβ3 integrin; the nanoparticles are then embedded with epirubicin (EPI). Cell viability assays and analysis of tissue histology reveal that EPI-loaded RGD-f-PNPs (RGD-f-PNPs/EPI) led to significantly reduced cardiotoxicity and improved anti-tumor activity compared to EPI alone. Moreover, the drug delivery to tumor sites and therapeutic responses could be monitored with near-infrared fluorescence using RGD-f-PNPs/EPI. This unique nanoparticle system may lead to potential approaches for bioorganic fluorescence-based delivering, imaging, and drug release tracking.
Highly stable QLEDs with improved hole injection via quantum dot structure tailoring
Authors: Cao Weiran , Xiang Chaoyu , Yang Yixing , Chen Qi , Chen Liwei , Yan Xiaolin , Qian Lei
Published: June 2018

For the state-of-the-art quantum dot light-emitting diodes, while the ZnO nanoparticle layers can provide effective electron injections into quantum dots layers, the hole transporting materials usually cannot guarantee sufficient hole injection owing to the deep valence band of quantum dots. Developing proper hole transporting materials to match energy levels with quantum dots remains a great challenge to further improve the device efficiency and operation lifetime. Here we demonstrate high-performance quantum dot light-emitting diodes with much extended operation lifetime using quantum dots with tailored energy band structures that are favorable for hole injections. These devices show a T95 operation lifetime of more than 2300 h with an initial brightness of 1000 cd m−2, and an equivalent T50 lifetime at 100 cd m−2 of more than 2,200,000 h, which meets the industrial requirement for display applications.
FerriTag is a new genetically-encoded inducible tag for correlative light-electron microscopy
Authors: Clarke Nicholas I. , Royle Stephen J.
Published: June 2018

A current challenge is to develop tags to precisely visualize proteins in cells by light and electron microscopy. Here, we introduce FerriTag, a genetically-encoded chemically-inducible tag for correlative light-electron microscopy. FerriTag is a fluorescent recombinant electron-dense ferritin particle that can be attached to a protein-of-interest using rapamycin-induced heterodimerization. We demonstrate the utility of FerriTag for correlative light-electron microscopy by labeling proteins associated with various intracellular structures including mitochondria, plasma membrane, and clathrin-coated pits and vesicles. FerriTagging has a good signal-to-noise ratio and a labeling resolution of approximately 10 nm. We demonstrate how FerriTagging allows nanoscale mapping of protein location relative to a subcellular structure, and use it to detail the distribution and conformation of huntingtin-interacting protein 1 related (HIP1R) in and around clathrin-coated pits.
microRNA-122 amplifies hepatitis C virus translation by shaping the structure of the internal ribosomal entry site
Authors: Schult Philipp , Roth Hanna , Adams Rebecca L. , Mas Caroline , Imbert Lionel , Orlik Christian , Ruggieri Alessia , Pyle Anna M. , Lohmann Volker
Published: June 2018

The liver-specific microRNA-122 (miR-122) recognizes two conserved sites at the 5′ end of the hepatitis C virus (HCV) genome and contributes to stability, translation, and replication of the viral RNA. We show that stimulation of the HCV internal ribosome entry site (IRES) by miR-122 is essential for efficient viral replication. The mechanism relies on a dual function of the 5′ terminal sequence in the complementary positive (translation) and negative strand (replication), requiring different secondary structures. Predictions and experimental evidence argue for several alternative folds involving the miR-binding region (MBR) adjacent to the IRES and interfering with its function. Mutations in the MBR, designed to suppress these dysfunctional structures indeed stimulate translation independently of miR-122. Conversely, MBR mutants favoring alternative folds show impaired IRES activity. Our results therefore suggest that miR-122 binding assists the folding of a functional IRES in an RNA chaperone-like manner by suppressing energetically favorable alternative secondary structures.
MiR-99b-5p and miR-203a-3p Function as Tumor Suppressors by Targeting IGF-1R in Gastric Cancer
Authors: Wang Zhenzhen , Zhao Zhenghao , Yang Yang , Luo Mai , Zhang Min , Wang Xiaofei , Liu Liying , Hou Ni , Guo Qingqing , Song Tusheng , Guo Bo , Huang Chen
Published: June 2018

MicroRNAs (miRNAs) have been explored in many critical cellular processes, including proliferation and apoptosis. The purpose of this study was to detect the biological function and regulation of miR-99b-5p and miR-203a-3p in gastric cancer (GC). Here, we demonstrated that miR-99b-5p/203a-3p were downregulated in both GC tissues and cell lines. MiR-99b-5p/203a-3p overexpression reduced GC cell proliferation and cell cycle progression in vitro. Notably, we combined bioinformatics tools with biological validation assays to demonstrate that insulin-like growth factor 1 receptor (IGF-1R) is a direct co-target and functional mediator of miR-99b-5p/203a-3p in GC cells. Mechanistically, the AKT pathway, which is downstream of IGF-1R, is essential for the functional roles of miR-99b-5p/203a-3p in GC cells. Taken together, our data revealed that IGF-1R is a direct co-target of miR-99b-5p/203a-3p, and miR-99b-5p/203a-3p may function as tumor suppressive miRNAs by negatively regulating IGF-1R expression in GC cells.
Down-regulation of circPVRL3 promotes the proliferation and migration of gastric cancer cells
Authors: Sun Han-Dong , Xu Zhi-Peng , Sun Zhi-Qiang , Zhu Bin , Wang Qian , Zhou Jian , Jin Hui , Zhao Andi , Tang Wei-Wei , Cao Xiu-Feng
Published: June 2018

Circular RNA (circRNA) is a key regulator in the development and progression of various types of carcinomas. However, its role in gastric cancer (GC) tumorigenesis is not well understood. The present study aimed to investigate the expression profile and potential modulation of circRNAs on GC carcinogenesis. Human circRNA microarray was performed to screen for abnormally expressed circRNA in GC tissue. Results showed that a decrease in the circPVRL3 expression level was associated with the presence of GC, and also with higher TNM stage and lower overall survival rates compared with that in adjacent noncancerous tissues. In vitro assays of the GC cell lines MKN-45 and MGC-803 demonstrated that knockdown of circPVRL3 promoted cell proliferation significantly. Prediction and annotation revealed circPVRL3 was able to sponge to 9 miRNAs and may be also able to have a binding with AGO2, FUS, LIN28A, PTB, and EIF4A3. In addition, based on the structure of internal ribosomal entry sites, open reading frame, and m6A modification, circPVRL3 may have the potential ability to encode proteins. Taken together, our study indicated that down-regulation of circPVRL3 could promote the proliferation in gastric carcinoma and have potential to encode protein.
Publisher Correction: TGF-β concentrations and activity are down-regulated in the aqueous humor of patients with neovascular age-related macular degeneration
Authors: Tosi Gian Marco , Neri Giovanni , Caldi Elena , Fusco Fiorella , Bacci Tommaso , Tarantello Antonio , Nuti Elisabetta , Marigliani Davide , Baiocchi Stefano , Traversi Claudio , Barbarino Marcella , Eandi Chiara M. , Parolini Barbara , Mundo Lucia , Santucci Annalisa , Orlandini Maurizio , Galvagni Federico
Published: June 2018

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
Neural signatures of reinforcement learning correlate with strategy adoption during spatial navigation
Authors: Anggraini Dian , Glasauer Stefan , Wunderlich Klaus
Published: June 2018

Human navigation is generally believed to rely on two types of strategy adoption, route-based and map-based strategies. Both types of navigation require making spatial decisions along the traversed way although formal computational and neural links between navigational strategies and mechanisms of value-based decision making have so far been underexplored in humans. Here we employed functional magnetic resonance imaging (fMRI) while subjects located different objects in a virtual environment. We then modelled their paths using reinforcement learning (RL) algorithms, which successfully explained decision behavior and its neural correlates. Our results show that subjects used a mixture of route and map-based navigation and their paths could be well explained by the model-free and model-based RL algorithms. Furthermore, the value signals of model-free choices during route-based navigation modulated the BOLD signals in the ventro-medial prefrontal cortex (vmPFC), whereas the BOLD signals in parahippocampal and hippocampal regions pertained to model-based value signals during map-based navigation. Our findings suggest that the brain might share computational mechanisms and neural substrates for navigation and value-based decisions such that model-free choice guides route-based navigation and model-based choice directs map-based navigation. These findings open new avenues for computational modelling of wayfinding by directing attention to value-based decision, differing from common direction and distances approaches.
Evaluation of surface charge shift of collagen fibrils exposed to glutaraldehyde
Authors: Mesquida Patrick , Kohl Dominik , Andriotis Orestis G. , Thurner Philipp J. , Duer Melinda , Bansode Sneha , Schitter Georg
Published: June 2018

Collagen fibrils are a major component of the extracellular matrix. They form nanometer-scale “cables” acting as a scaffold for cells in animal tissues and are widely used in tissue-engineering. Besides controlling their structure and mechanical properties, it is crucial to have information of their surface charge, as this affects how cells attach to the scaffold. Here, we employed Kelvin-probe Force Microscopy to determine the electrostatic surface potential at the single-fibril level and investigated how glutaraldehyde, a well-established protein cross-linking agent, shifts the surface charge to more negative values without disrupting the fibrils themselves. This shift can be interpreted as the result of the reaction between the carbonyl groups of glutaraldehyde and the amine groups of collagen. It reduces the overall density of positively charged amine groups on the collagen fibril surface and, ultimately, results in the observed negative shift of the surface potential measured. Reactions between carbonyl-containing compounds and proteins are considered the first step in glycation, the non-enzymatic reaction between sugars and proteins. It is conceivable that similar charge shifts happen in vivo caused by sugars, which could have serious implications on age-related diseases such as diabetes and which has been hypothesised for many years.
Enzootic frog pathogen Batrachochytrium dendrobatidis in Asian tropics reveals high ITS haplotype diversity and low prevalence
Authors: Mutnale Milind C. , Anand Sachin , Eluvathingal Lilly M. , Roy Jayanta K. , Reddy Gundlapally S. , Vasudevan Karthikeyan
Published: June 2018

Emerging Infectious Diseases (EIDs) are a major threat to wildlife and a key player in the declining amphibian populations worldwide. One such EID is chytridiomycosis caused by Batrachochytrium dendrobatidis (Bd), a fungal pathogen. Aetiology of Bd infection is poorly known from tropical frogs in Asian biodiversity hotspots. Surveys were carried out in four biodiversity hotspots to ascertain the status of Bd fungus. We collected a total of 1870 swab samples from frogs representing 32 genera and 111 species. Nested PCRs revealed low prevalence (8.4%) and high Bd haplotype richness was revealed after sequencing. We document 57 Bd Internal Transcribed Spacer region (ITS) haplotypes, of which 46 were unique to the global database. Bd ITS region showed indels at the Taqman binding site and qPCR reverse primer binding site, suggesting qPCR is unsuitable for diagnosis in Asian Bd coldspots. Our median-joining network and Bayesian tree analyses reveal that the Asian haplotypes, with the exception of Korea, formed a separate clade along with pandemic BdGPL (Bd Global Panzootic Lineage) haplotype. We hypothesise that the frog populations in Asian tropics might harbour several endemic strains of Bd, and the high levels of diversity and uniqueness of Bd haplotypes in the region, probably resulted from historical host-pathogen co-evolution.
Altered cortical functional network during behavioral inhibition in individuals with childhood trauma
Authors: Kim Sungkean , Kim Ji Sun , Shim Miseon , Im Chang-Hwan , Lee Seung-Hwan
Published: June 2018

Individuals who have prior history of childhood traumatic experiences are at a high risk for a variety of psychological and behavioral problems throughout their lifetime. This study aimed to investigate whether such individuals exhibit altered cortical functional networks during a behavioral inhibition task. One hundred fifty-three non-clinical individuals were recruited and instructed to perform a Go/NoGo task during an electroencephalograph. Source-level weighted functional networks based on the graph theory were analyzed for NoGo-P3 processing. Based on their total scores on the childhood trauma questionnaire (CTQ) participants were divided into three groups: low CTQ, middle CTQ, and high CTQ. Results at the global level indicated decreased strength, clustering coefficient, and efficiency for the low and gamma bands in the high CTQ group. In addition, the path length of the low beta band was observed to be longer in the high CTQ group than the low CTQ group. At the nodal level, the nodal clustering coefficient of high CTQ group was decreased in left primary somatosensory cortex and middle occipital gyrus for the low beta band, and in left superior temporal gyrus for the gamma band. The nodal clustering coefficient of the left primary somatosensory cortex showed a significant negative correlation with the total CTQ score for the low beta band. In addition, the nodal clustering coefficient of the left middle occipital gyrus for the low beta band and superior temporal gyrus for the gamma band showed significant negative correlations with the emotional neglect score. Our results demonstrate an altered cortical functional network in individuals who experienced childhood trauma. In particular, the left primary somatosensory cortex, middle occipital gyrus, and superior temporal gyrus were found to be vulnerable in individuals who experienced childhood trauma, especially emotional neglect.
Measuring shared knowledge with group false memory
Authors: Arima Yoshiko , Yukihiro Ryoji , Hattori Yosuke
Published: June 2018

We conducted two experiments to investigate the effects of word list consistency and group collaboration on false memory. Using the DRM (Deese-Roediger-McDermott) paradigm, the first experiment (n = 121) examined false memory in a group; participants collaborated to select keywords using a between-subject condition of a consistent or randomized word list. The proportion of false responses was larger than that of error responses, especially for the consistent word list condition (p < 0.001), and group collaboration increased false recognition for both word lists (p < 0.001). Using an applied within-subject word list condition, the second experiment (n = 119) confirmed the results of Experiment 1. Furthermore, individual differences Euclidean distance model analysis revealed a difference in the shared cognitive dimension related to group false memory.
Dosage compensation and DNA methylation landscape of the X chromosome in mouse liver
Authors: Duncan Christopher G. , Grimm Sara A. , Morgan Daniel L. , Bushel Pierre R. , Bennett Brian D. ,   NISC Comparative Sequencing Program, Barnabas Beatrice B. , Bouffard Gerard G. , Brooks Shelise Y. , Coleman Holly , Dekhtyar Lyudmila , Guan Xiaobin , Han Joel , Ho Shi-ling , Legaspi Richelle , Maduro Quino L. , Masiello Catherine A. , McDowell Jennifer C. , Montemayor Casandra , Mullikin James C. , Park Morgan , Riebow Nancy L. , Schandler Karen , Schmidt Brian , Sison Christina , Smith Raymond , Stantripop Sirintorn , Thomas James W. , Thomas Pamela J. , Vemulapalli Meghana , Young Alice C. , Roberts John D. , Tyson Frederick L. , Merrick B. Alex , Wade Paul A.
Published: June 2018

DNA methylation plays a key role in X-chromosome inactivation (XCI), a process that achieves dosage compensation for X-encoded gene products between mammalian female and male cells. However, differential sex chromosome dosage complicates genome-wide epigenomic assessments, and the X chromosome is frequently excluded from female-to-male comparative analyses. Using the X chromosome in the sexually dimorphic mouse liver as a model, we provide a general framework for comparing base-resolution DNA methylation patterns across samples that have different chromosome numbers and ask at a systematic level if predictions by historical analyses of X-linked DNA methylation hold true at a base-resolution chromosome-wide level. We demonstrate that sex-specific methylation patterns on the X chromosome largely reflect the effects of XCI. While our observations concur with longstanding observations of XCI at promoter-proximal CpG islands, we provide evidence that sex-specific DNA methylation differences are not limited to CpG island boundaries. Moreover, these data support a model in which maintenance of CpG islands in the inactive state does not require complete regional methylation. Further, we validate an intragenic non-CpG methylation signature in genes escaping XCI in mouse liver. Our analyses provide insight into underlying methylation patterns that should be considered when assessing sex differences in genome-wide methylation analyses.
Motivational goal-priming with or without awareness produces faster and stronger force exertion
Authors: Takarada Yudai , Nozaki Daichi
Published: June 2018

Previous research has demonstrated that barely visible (subliminal) goal-priming with motivational reward can alter the state of the motor system and enhance motor output. Research shows that these affective-motivational effects result from associations between goal representations and positive affect without conscious awareness. Here, we tested whether motivational priming can increase motor output even if the priming is fully visible (supraliminal), and whether the priming effect occurs through increased cortical excitability. Groups of participants were primed with either barely visible or fully visible words related to effort and control sequences of random letters that were each followed by fully visible positively reinforcing words. The priming effect was measured behaviourally by handgrip force and reaction time to the grip cue after the priming was complete. Physiologically, the effects were measured by pupil dilation and motor-evoked potentials (MEPs) in response to transcranial magnetic stimulation during the priming task. Analysis showed that for both the supraliminal and subliminal conditions, reaction time decreased and total force, MEP magnitude, and pupil dilation increased. None of the priming-induced changes in behaviour or physiology differed significantly between the supraliminal and the subliminal groups, indicating that implicit motivation towards motor goals might not require conscious perception of the goals.
Prevalence and risk factors of latent tuberculosis among Korean healthcare workers using whole-blood interferon-γ release assay
Authors: Yeon Jeong Hwa , Seong Hye , Hur Ho , Park Yoonseon , Kim Young Ah , Park Yoon Soo , Han Chang Hoon , Lee Sun Min , Seo Jeong Hun , Kang Jung Gu
Published: June 2018

Because healthcare workers (HCWs) are at high risk for tuberculosis (TB) infection, it is essential to research the prevalence of latent TB infection (LTBI) and to implement health interventions including early treatment of LTBI and TB infection control measures. The purpose of the study was to determine the prevalence and risk factors for LTBI using interferon-γ release assay (IGRA) among HCWs in South Korea. The cross-sectional study was carried in the National Health Insurance Service Ilsan Hospital, which is a 740-bed general hospital, South Korea. HCWs who participated in this survey were required to complete a questionnaire and IGRA was performed. Of the 1,655 HCWs, 271 results were positive and the prevalence of LTBI was 16% (95% CI; 15–18%). In the multivariate analysis, age (OR; 2.201, 95% CI; 1.911–2.536, P < 0.001), male sex (OR; 1.523, 95% CI; 1.133–2.046, P = 0.005), contact active TB patients (OR; 1.461, 95% CI; 1.061–2.010, P = 0.02) and diabetes (OR; 2.837, 95% CI; 1.001–8.044, P = 0.05) were significant risk factors for LTBI. LTBI among HCWs in Korea, although prevalent, might not exceed the background level of the general population. Because contact with active TB patients has been identified as a risk factor for LTBI, more effective TB infection control measures are essential in healthcare facilities and congregate settings.
Towards Laser-Textured Antibacterial Surfaces
Authors: Lutey Adrian H. A. , Gemini Laura , Romoli Luca , Lazzini Gianmarco , Fuso Francesco , Faucon Marc , Kling Rainer
Published: June 2018

Escherichia coli and Staphylococcus aureus bacterial retention on mirror-polished and ultrashort pulse laser-textured surfaces is quantified with a new approach based on ISO standards for measurement of antibacterial performance. It is shown that both wettability and surface morphology influence antibacterial behavior, with neither superhydrophobicity nor low surface roughness alone sufficient for reducing initial retention of either tested cell type. Surface structures comprising spikes, laser-induced periodic surface structures (LIPSS) and nano-pillars are produced with 1030 nm wavelength 350 fs laser pulses of energy 19.1 μJ, 1.01 μJ and 1.46 μJ, respectively. SEM analysis, optical profilometry, shear force microscopy and wettability analysis reveal surface structures with peak separations of 20–40 μm, 0.5–0.9 μm and 0.8–1.3 μm, average areal surface roughness of 8.6 μm, 90 nm and 60 nm and static water contact angles of 160°, 119° and 140°, respectively. E. coli retention is highest for mirror-polished specimens and spikes whose characteristic dimensions are much larger than the cell size. S. aureus retention is instead found to be inhibited under the same conditions due to low surface roughness for mirror-polished samples (Sa: 30 nm) and low wettability for spikes. LIPSS and nano-pillars are found to reduce E. coli retention by 99.8% and 99.2%, respectively, and S. aureus retention by 84.7% and 79.9% in terms of viable colony forming units after two hours of immersion in bacterial broth due to both low wettability and fine surface features that limit the number of available attachment points. The ability to tailor both wettability and surface morphology via ultrashort pulsed laser processing confirms this approach as an important tool for producing the next generation of antibacterial surfaces.
Inorganic carbon and nitrogen assimilation in cellular compartments of a benthic kleptoplastic foraminifer
Authors: LeKieffre Charlotte , Jauffrais Thierry , Geslin Emmanuelle , Jesus Bruno , Bernhard Joan M. , Giovani Maria-Evangelia , Meibom Anders
Published: June 2018

Haynesina germanica, an ubiquitous benthic foraminifer in intertidal mudflats, has the remarkable ability to isolate, sequester, and use chloroplasts from microalgae. The photosynthetic functionality of these kleptoplasts has been demonstrated by measuring photosystem II quantum efficiency and O2 production rates, but the precise role of the kleptoplasts in foraminiferal metabolism is poorly understood. Thus, the mechanism and dynamics of C and N assimilation and translocation from the kleptoplasts to the foraminiferal host requires study. The objective of this study was to investigate, using correlated TEM and NanoSIMS imaging, the assimilation of inorganic C and N (here ammonium, NH4+) in individuals of a kleptoplastic benthic foraminiferal species. H. germanica specimens were incubated for 20 h in artificial seawater enriched with H13CO3− and 15NH4+ during a light/dark cycle. All specimens (n = 12) incorporated 13C into their endoplasm stored primarily in the form of lipid droplets. A control incubation in darkness resulted in no 13C-uptake, strongly suggesting that photosynthesis is the process dominating inorganic C assimilation. Ammonium assimilation was observed both with and without light, with diffuse 15N-enrichment throughout the cytoplasm and distinct 15N-hotspots in fibrillar vesicles, electron-opaque bodies, tubulin paracrystals, bacterial associates, and, rarely and at moderate levels, in kleptoplasts. The latter observation might indicate that the kleptoplasts are involved in N assimilation. However, the higher N assimilation observed in the foraminiferal endoplasm incubated without light suggests that another cytoplasmic pathway is dominant, at least in darkness. This study clearly shows the advantage provided by the kleptoplasts as an additional source of carbon and provides observations of ammonium uptake by the foraminiferal cell.
A misaligned magneto-optical trap to enable miniaturized atom chip systems
Authors: Roy Ritayan , Rushton Jo , Dragomir Andrei , Aldous Matthew , Himsworth Matt
Published: June 2018

We describe the application of displaced, or misaligned, beams in a mirror-based magneto-optical trap (MOT) to enable portable and miniaturized atom chip experiments where optical access is limited to a single window. Two different geometries of beam displacement are investigated: a variation on the well-known ‘vortex-MOT’, and the other a novel ‘hybrid-MOT’ combining Zeeman-shifted and purely optical scattering force components. The beam geometry is obtained similar to the mirror-MOT, using a planar mirror surface but with a different magnetic field geometry more suited to planar systems. Using these techniques, we have trapped around 6 × 106 and 26 × 106 atoms of 85Rb in the vortex-MOT and hybrid-MOT respectively. For the vortex-MOT the atoms are directly cooled well below the Doppler temperature without any additional sub-Doppler cooling stage, whereas the temperature of the hybrid-MOT has been measured slightly above the Doppler temperature limit. In both cases the attained lower temperature ensures the quantum behaviour of the trapped atoms required for the applications of portable quantum sensors and many others.
Concurrent TSHR mutations and DIO2 T92A polymorphism result in abnormal thyroid hormone metabolism
Authors: Park Eunkuk , Jung Jaehoon , Araki Osamu , Tsunekawa Katsuhiko , Park So Young , Kim Jeonghyun , Murakami Masami , Jeong Seon-Yong , Lee Sihoon
Published: June 2018

Deiodinase 2 (DIO2) plays an important role in thyroid hormone metabolism and its regulation. However, molecular mechanism that regulates DIO2 activity remains unclear; only mutaions in selenocysteine insertion sequence binding protein 2 and selenocysteine tranfer RNA (tRNA[Ser]Sec) are reported to result in decreased DIO2 activity. Two patients with clinical evidence of abnormal thyroid hormone metabolism were identified and found to have TSHR mutations as well as DIO2 T92A single nucleotide polymorphism (SNP). Primary-cultured fibroblasts from one patient present a high level of basal DIO2 enzymatic activity, possibly due to compensation by augmented DIO2 expression. However, this high enzymatic active state yet fails to respond to accelerating TSH. Consequently, TSHR mutations along with DIO2 T92A SNP (“double hit”) may lead to a significant reduction in DIO2 activity stimulated by TSH, and thereby may have clinical relevance in a select population of hypothyroidism patients who might benefit from a T3/T4 combination therapy.
Environmental properties of cells improve machine learning-based phenotype recognition accuracy
Authors: Toth Timea , Balassa Tamas , Bara Norbert , Kovacs Ferenc , Kriston Andras , Molnar Csaba , Haracska Lajos , Sukosd Farkas , Horvath Peter
Published: June 2018

To answer major questions of cell biology, it is often essential to understand the complex phenotypic composition of cellular systems precisely. Modern automated microscopes produce vast amounts of images routinely, making manual analysis nearly impossible. Due to their efficiency, machine learning-based analysis software have become essential tools to perform single-cell-level phenotypic analysis of large imaging datasets. However, an important limitation of such methods is that they do not use the information gained from the cellular micro- and macroenvironment: the algorithmic decision is based solely on the local properties of the cell of interest. Here, we present how various features from the surrounding environment contribute to identifying a cell and how such additional information can improve single-cell-level phenotypic image analysis. The proposed methodology was tested for different sizes of Euclidean and nearest neighbour-based cellular environments both on tissue sections and cell cultures. Our experimental data verify that the surrounding area of a cell largely determines its entity. This effect was found to be especially strong for established tissues, while it was somewhat weaker in the case of cell cultures. Our analysis shows that combining local cellular features with the properties of the cell’s neighbourhood significantly improves the accuracy of machine learning-based phenotyping.
Gene expression profile in peripheral blood mononuclear cells of postpartum depression patients
Authors: Pan Danqing , Xu Yuemei , Zhang Lei , Su Qizhu , Chen Manman , Li Bing , Xiao Qian , Gao Qi , Peng Xiuhua , Jiang Binfei , Gu Yilu , Du Yuling , Gao Pengfei
Published: June 2018

Postpartum depression (PPD) is a common mental health problem that causes maternal suffering and various negative consequences for offspring. The pathogenesis of PPD and the causes of consequences for offspring remain largely unknown. Here, we applied RNA sequencing to sequence the whole transcriptomes of peripheral blood mononuclear cells (PBMCs) from PPD patients (Edinburgh Postnatal Depression Scale [EPDS] score ≥13) and control subjects (EPDS = 0). We found that PPD was positively correlated with multiple genes involved in energy metabolism, neurodegenerative diseases and immune response, while negatively correlated with multiple genes in mismatch repair and cancer-related pathways. Remarkably, genes associated with appetite regulation and nutrient response were differentially expressed between PPD and control subjects. Then, we employed a postnatal growth retardation model by repeated immobilization stress (IS) stimulation to maternal mice. The expression of appetite regulation and nutrient response-related genes in the PBMCs of IS mice and in the hypothalamus of their offspring were also affected. In conclusion, this study provides a comprehensive characterization of the PBMCs transcriptome in PPD and suggests that maternal stress may affect appetite regulation and nutrient response in the hypothalamus of offspring mice.
Isoquercetin and inulin synergistically modulate the gut microbiome to prevent development of the metabolic syndrome in mice fed a high fat diet
Authors: Tan Si , Caparros-Martin Jose A. , Matthews Vance B. , Koch Henrietta , O’Gara Fergal , Croft Kevin D. , Ward Natalie C.
Published: June 2018

Dietary fibre positively influences gut microbiome composition, enhancing the metabolism of dietary flavonoids to produce bioactive metabolites. These synergistic activities facilitate the beneficial effects of dietary flavonoids on cardiometabolic health parameters. The aims of this study were to investigate whether isoquercetin (a major dietary flavonoid) and inulin (soluble fibre), either alone or in combination could improve features of the metabolic syndrome. Following a 1 week acclimatization, male C57BL6 mice (6–8 weeks) were randomly assigned to; (i) normal chow diet (n = 10), (ii) high fat (HF) diet (n = 10), (iii) HF diet + 0.05% isoquercetin (n = 10), (iv) HF diet + 5% inulin, or (v) HF diet + 0.05% isoquercetin + 5% inulin (n = 10). Body weight and food intake were measured weekly. At 12 weeks, glucose and insulin tolerance tests were performed, and blood, faecal samples, liver, skeletal muscle and adipose tissue were collected. At 12 weeks, mice on the HF diet had significantly elevated body weights as well as impaired glucose tolerance and insulin sensitivity compared to the normal chow mice. Supplementation with either isoquercetin or inulin had no effect, however mice receiving the combination had attenuated weight gain, improved glucose tolerance and insulin sensitivity, reduced hepatic lipid accumulation, adipocyte hypertrophy, circulating leptin and adipose FGF21 levels, compared to mice receiving the HF diet. Additionally, mice on the combination diet had improvements in the composition and functionality of their gut microbiome as well as production of short chain fatty acids. In conclusion, long-term supplementation with the dietary flavonoid isoquercetin and the soluble fibre inulin can attenuate development of the metabolic syndrome in mice fed a high fat diet. This protective effect appears to be mediated, in part, through beneficial changes to the microbiome.
Tweaking the Electronic and Optical Properties of α-MoO3 by Sulphur and Selenium Doping – a Density Functional Theory Study
Authors: Bandaru Sateesh , Saranya Govindarajan , English Niall J. , Yam Chiyung , Chen Mingyang
Published: June 2018

First-principles calculations were carried out to understand how anionic isovalent-atom doping affects the electronic structures and optical properties of α-MoO3. The effects of the sulphur and selenium doping at the three unique oxygen sites (Ot, Oa, and Ot) of α-MoO3 were examined. We found that the valence p orbitals of Sulphur/Selenium dopant atoms give rise to impurity bands above the valence band maximum in the band structure of α-MoO3. The number of impurity bands in the doped material depends on the specific doping sites and the local chemical environment of the dopants in MoO3. The impurity bands give rise to the enhanced optical absorptions of the S- and Se-doped MoO3 in the visible and infrared regions. At low local doping concentration, the effects of the dopant sites on the electronic structure of the material are additive, so increasing the doping concentration will enhance the optical absorption properties of the material in the visible and infrared regions. Further increasing the doping concentration will result in a larger gap between the maximum edge of impurity bands and the conduction band minimum, and will undermine the optical absorption in the visible and infrared region. Such effects are caused by the local geometry change at the high local doping concentration with the dopants displaced from the original O sites, so the resulting impurity bands are no long the superpositions of the impurity bands of each individual on-site dopant atom. Switching from S-doping to Se-doping decreases the gap between the maximum edge of the impurity bands and conduction band minimum, and leads to the optical absorption edge red-shifting further into the visible and infrared regions.
Vehicle criteria pollutant (PM, NOx, CO, HCs) emissions: how low should we go?
Authors: Winkler S. L. , Anderson J. E. , Garza L. , Ruona W. C. , Vogt R. , Wallington T. J.
Published: June 2018

Over the past 30–40 years, vehicle tailpipe emissions of particulate matter (PM), nitrogen oxides (NOx), carbon monoxide (CO), and hydrocarbons (HCs) have decreased significantly. Advanced emission after-treatment technologies have been developed for gasoline and diesel vehicles to meet increasingly stringent regulations, yielding absolute emission reductions from the fleet despite increased vehicle travel. As a result of mobile and stationary source emission controls, air quality has generally improved substantially in cities across the US and Europe. Emission regulations (such as Tier 3 in the US, LEV III in California, and Euro 6 rules in the EU) will lead to even lower vehicle emissions and further improvements in air quality. We review historical vehicle emission and air quality trends, discuss the future outlook for air quality, and note that modern internal combustion engine vehicles typically have lower exhaust emissions than battery electric vehicle upstream emissions. As vehicle manufacturers and city officials grapple with questions about future mobility in cities, we raise the question “how low should we go?” for future vehicle criteria emissions. The answer to this question will have profound implications for automotive and fuel companies and for the future economic and environmental health of urban areas.
Evidence of non-tandemly repeated rDNAs and their intragenomic heterogeneity in Rhizophagus irregularis
Authors: Maeda Taro , Kobayashi Yuuki , Kameoka Hiromu , Okuma Nao , Takeda Naoya , Yamaguchi Katsushi , Bino Takahiro , Shigenobu Shuji , Kawaguchi Masayoshi
Published: June 2018

Arbuscular mycorrhizal fungus (AMF) species are some of the most widespread symbionts of land plants. Our much improved reference genome assembly of a model AMF, Rhizophagus irregularis DAOM-181602 (total contigs = 210), facilitated a discovery of repetitive elements with unusual characteristics. R. irregularis has only ten or 11 copies of complete 45S rDNAs, whereas the general eukaryotic genome has tens to thousands of rDNA copies. R. irregularis rDNAs are highly heterogeneous and lack a tandem repeat structure. These findings provide evidence for the hypothesis that rDNA heterogeneity depends on the lack of tandem repeat structures. RNA-Seq analysis confirmed that all rDNA variants are actively transcribed. Observed rDNA/rRNA polymorphisms may modulate translation by using different ribosomes depending on biotic and abiotic interactions. The non-tandem repeat structure and intragenomic heterogeneity of AMF rDNA/rRNA may facilitate successful adaptation to various environmental conditions, increasing host compatibility of these symbiotic fungi.
Direct Observation of Hierarchic Molecular Interactions Critical to Biogenic Aerosol Formation
Authors: Hou Gao-Lei , Lin Wei , Wang Xue-Bin
Published: June 2018

Small clusters consisting of sulfuric acid/bisulfate and oxidized organics have been identified in both aerosol field measurements and laboratory experiments, and their formation is suggested to be the rate-limiting step in the formation of new particles. However, the underlying mechanism for cluster formation is still largely unclear. Here we show, through an integrated negative ion photoelectron spectroscopy and quantum chemical study on a series of (HSO4−)(organic molecule) surrogate binary clusters, that the functional groups are more important in determining the extent of the enhanced role of the organics in aerosol formation process than the average carbon oxidation states or O/C ratios. This extent is quantified explicitly for specific functional groups, revealing highly hierarchic intermolecular interactions critical to aerosol formation. Born–Oppenheimer molecular dynamics simulations are employed to probe the water-binding abilities of these clusters under ambient conditions, and their statistical hydrogen-bonding networks.
Kinetic barriers to α-synuclein protofilament formation and conversion into mature fibrils
Authors: Brown James W. P. , Meisl Georg , Knowles Tuomas P. J. , Buell Alexander K. , Dobson Christopher M. , Galvagnion Céline
Published: June 2018

An increase in temperature allows the conversion of α-synuclein lipid-induced proto-fibrils to mature fibrils by overcoming the associated energy barrier.
Production of dynamic lipid bilayers using the reversible thiol–thioester exchange reaction
Authors: Konetski Danielle , Mavila Sudheendran , Wang Chen , Worrell Brady , Bowman Christopher N.
Published: June 2018

Coupling of phospholipid precursors using the reversible thiol–thioester exchange reaction enables downstream remodeling and functionalization.
A flexible ionic synaptic device and diode-based aqueous ion sensor utilizing asymmetric polyelectrolyte distribution
Authors: Zhao Yiwei , Dai Shilei , Chu Yingli , Wu Xiaohan , Huang Jia
Published: June 2018

Two terminal ionic synaptic devices and pH sensors based on ionic diodes were developed by utilizing asymmetric polyelectrolyte distribution.
Glutathione-responsive homodithiacalix[4]arene-based nanoparticles for selective intracellular drug delivery
Authors: Cheng Qian , Yin Hang , Sun Chen , Yue Ludan , Ding Yuanfu , Dehaen Wim , Wang Ruibing
Published: June 2018

Glutathione-responsive, paclitaxel-loaded nanoparticles based on homodithiacalix[4]arene were successfully developed, exhibiting selective drug release in cancer cells.
Dion–Jacobson-type perovskite KCa2Ta3O10 nanosheets hybridized with g-C3N4 nanosheets for photocatalytic H2 production
Authors: Jiang Deli , Ma Wanxia , Yao Yingjie , Xiao Peng , Wen Baowei , Li Di , Chen Min
Published: June 2018

Dion–Jacobson-type perovskite oxide KCa2Ta3O10 has been identified as a promising semiconductor for construction of hybrid catalyst for photocatalytic H2 evolution.