bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of Interplanetary Dust Detected by the Juno Spacecraft and Its Contribution to the Zodiacal Light
Authors: Jorgensen J. L. , Benn M. , Connerney J. E. P. , Denver T. , Jorgensen P. S. , Andersen A. C. , Bolton S. J.
Published: November 2020

The Solar System is home to a cloud of dust that orbits the Sun and makes its presence known by virtue of scattered light (Zodiacal Light) that can be seen after dusk and before dawn. Within this cloud are bands of dust orbiting near the ecliptic plane, evidenced by an excess of scattered light at discrete ecliptic latitudes. Dedicated dust detectors borne by spacecraft in transit of the solar system have detected few such particles of the appropriate size owing to limited detector aperture and sparsity of the population. Thus, the distribution, origin, and orbital evolution of the dust in these bands remains a mystery. A star camera aboard the Juno spacecraft traveling from Earth to Jupiter recorded interplanetary dust impacts on the spacecraft in numbers sufficient to characterize the spatial distribution of such particles for the first time. The observed distribution is consistent with a primary source of dust particles sharing the Mars orbit plane between Earth and the 4:1 resonance with Jupiter. We propose that the primary distribution is scattered by orbital resonances with Jupiter via the Kozai‐Lidov (KL) effect into a secondary population at higher inclination to the ecliptic. The measured dust distribution, occupying a volume uniquely determined by the orbital elements of Mars and KL scattering, accounts for the observed variation of the Zodiacal Light with ecliptic latitude. Our results provide a compelling alternative to the prevailing theory of the origin and evolution of interplanetary dust observed at low ecliptic latitudes.
Early-life stress alters affective behaviors in adult mice through persistent activation of CRH-BDNF signaling in the oval bed nucleus of the stria terminalis
Authors: Hu Pu , Maita Isabella , Phan Mimi L. , Gu Edward , Kwok Christopher , Dieterich Andrew , Gergues Mark M. , Yohn Christine N. , Wang Yu , Zhou Jiang-Ning , Qi Xin-Rui , Swaab Dick F. , Pang Zhiping P. , Lucassen Paul J. , Roepke Troy A. , Samuels Benjamin A.
Published: November 2020

Early-life stress (ELS) leads to stress-related psychopathology in adulthood. Although dysfunction of corticotropin-releasing hormone (CRH) signaling in the bed nucleus of the stria terminalis (BNST) mediates chronic stress-induced maladaptive affective behaviors that are historically associated with mood disorders such as anxiety and depression, it remains unknown whether ELS affects CRH function in the adult BNST. Here we applied a well-established ELS paradigm (24 h maternal separation (MS) at postnatal day 3) and assessed the effects on CRH signaling and electrophysiology in the oval nucleus of BNST (ovBNST) of adult male mouse offspring. ELS increased maladaptive affective behaviors, and amplified mEPSCs and decreased M-currents (a voltage-gated K+ current critical for stabilizing membrane potential) in ovBNST CRH neurons, suggesting enhanced cellular excitability. Furthermore, ELS increased the numbers of CRH+ and PACAP+ (the pituitary adenylate cyclase-activating polypeptide, an upstream CRH regulator) cells and decreased STEP+ (striatal-enriched protein tyrosine phosphatase, a CRH inhibitor) cells in BNST. Interestingly, ELS also increased BNST brain-derived neurotrophic factor (BDNF) expression, indicating enhanced neuronal plasticity. These electrophysiological and behavioral effects of ELS were reversed by chronic application of the CRHR1-selective antagonist R121919 into ovBNST, but not when BDNF was co-administered. In addition, the neurophysiological effects of BDNF on M-currents and mEPSCs in BNST CRH neurons mimic effects and were abolished by PKC antagonism. Together, our findings indicate that ELS results in a long-lasting activation of CRH signaling in the mouse ovBNST. These data highlight a regulatory role of CRHR1 in the BNST and for BDNF signaling in mediating ELS-induced long-term behavioral changes.
The tumor suppressor microRNA let-7 inhibits human LINE-1 retrotransposition
Authors: Tristán-Ramos Pablo , Rubio-Roldan Alejandro , Peris Guillermo , Sánchez Laura , Amador-Cubero Suyapa , Viollet Sebastien , Cristofari Gael , Heras Sara R.
Published: November 2020

Nearly half of the human genome is made of transposable elements (TEs) whose activity continues to impact its structure and function. Among them, Long INterspersed Element class 1 (LINE-1 or L1) elements are the only autonomously active TEs in humans. L1s are expressed and mobilized in different cancers, generating mutagenic insertions that could affect tumor malignancy. Tumor suppressor microRNAs are ∼22nt RNAs that post-transcriptionally regulate oncogene expression and are frequently downregulated in cancer. Here we explore whether they also influence L1 mobilization. We show that downregulation of let-7 correlates with accumulation of L1 insertions in human lung cancer. Furthermore, we demonstrate that let-7 binds to the L1 mRNA and impairs the translation of the second L1-encoded protein, ORF2p, reducing its mobilization. Overall, our data reveals that let-7, one of the most relevant microRNAs, maintains somatic genome integrity by restricting L1 retrotransposition.
Complex reaction processes in combustion unraveled by neural network-based molecular dynamics simulation
Authors: Zeng Jinzhe , Cao Liqun , Xu Mingyuan , Zhu Tong , Zhang John Z. H.
Published: November 2020

Combustion is a complex chemical system which involves thousands of chemical reactions and generates hundreds of molecular species and radicals during the process. In this work, a neural network-based molecular dynamics (MD) simulation is carried out to simulate the benchmark combustion of methane. During MD simulation, detailed reaction processes leading to the creation of specific molecular species including various intermediate radicals and the products are intimately revealed and characterized. Overall, a total of 798 different chemical reactions were recorded and some new chemical reaction pathways were discovered. We believe that the present work heralds the dawn of a new era in which neural network-based reactive MD simulation can be practically applied to simulating important complex reaction systems at ab initio level, which provides atomic-level understanding of chemical reaction processes as well as discovery of new reaction pathways at an unprecedented level of detail beyond what laboratory experiments could accomplish.
Interactive analysis of single-cell epigenomic landscapes with ChromSCape
Authors: Prompsy Pacôme , Kirchmeier Pia , Marsolier Justine , Deloger Marc , Servant Nicolas , Vallot Céline
Published: November 2020

Chromatin modifications orchestrate the dynamic regulation of gene expression during development and in disease. Bulk approaches have characterized the wide repertoire of histone modifications across cell types, detailing their role in shaping cell identity. However, these population-based methods do not capture cell-to-cell heterogeneity of chromatin landscapes, limiting our appreciation of the role of chromatin in dynamic biological processes. Recent technological developments enable the mapping of histone marks at single-cell resolution, opening up perspectives to characterize the heterogeneity of chromatin marks in complex biological systems over time. Yet, existing tools used to analyze bulk histone modifications profiles are not fit for the low coverage and sparsity of single-cell epigenomic datasets. Here, we present ChromSCape, a user-friendly interactive Shiny/R application distributed as a Bioconductor package, that processes single-cell epigenomic data to assist the biological interpretation of chromatin landscapes within cell populations. ChromSCape analyses the distribution of repressive and active histone modifications as well as chromatin accessibility landscapes from single-cell datasets. Using ChromSCape, we deconvolve chromatin landscapes within the tumor micro-environment, identifying distinct H3K27me3 landscapes associated with cell identity and breast tumor subtype.
MEKK2 mediates aberrant ERK activation in neurofibromatosis type I
Authors: Bok Seoyeon , Shin Dong Yeon , Yallowitz Alisha R. , Eiseman Mark , Cung Michelle , Xu Ren , Li Na , Sun Jun , Williams Alfred L. , Scott John E. , Su Bing , Shim Jae-Hyuck , Greenblatt Matthew B.
Published: November 2020

Neurofibromatosis type I (NF1) is characterized by prominent skeletal manifestations caused by NF1 loss. While inhibitors of the ERK activating kinases MEK1/2 are promising as a means to treat NF1, the broad blockade of the ERK pathway produced by this strategy is potentially associated with therapy limiting toxicities. Here, we have sought targets offering a more narrow inhibition of ERK activation downstream of NF1 loss in the skeleton, finding that MEKK2 is a novel component of a noncanonical ERK pathway in osteoblasts that mediates aberrant ERK activation after NF1 loss. Accordingly, despite mice with conditional deletion of Nf1 in mature osteoblasts (Nf1fl/fl;Dmp1-Cre) and Mekk2−/− each displaying skeletal defects, Nf1fl/fl;Mekk2−/−;Dmp1-Cre mice show an amelioration of NF1-associated phenotypes. We also provide proof-of-principle that FDA-approved inhibitors with activity against MEKK2 can ameliorate NF1 skeletal pathology. Thus, MEKK2 functions as a MAP3K in the ERK pathway in osteoblasts, offering a potential new therapeutic strategy for the treatment of NF1.
The Polycomb group protein Ring1 regulates dorsoventral patterning of the mouse telencephalon
Authors: Eto Hikaru , Kishi Yusuke , Yakushiji-Kaminatsui Nayuta , Sugishita Hiroki , Utsunomiya Shun , Koseki Haruhiko , Gotoh Yukiko
Published: November 2020

Dorsal-ventral patterning of the mammalian telencephalon is fundamental to the formation of distinct functional regions including the neocortex and ganglionic eminence. While Bone morphogenetic protein (BMP), Wnt, and Sonic hedgehog (Shh) signaling are known to determine regional identity along the dorsoventral axis, how the region-specific expression of these morphogens is established remains unclear. Here we show that the Polycomb group (PcG) protein Ring1 contributes to the ventralization of the mouse telencephalon. Deletion of Ring1b or both Ring1a and Ring1b in neuroepithelial cells induces ectopic expression of dorsal genes, including those for BMP and Wnt ligands, as well as attenuated expression of the gene for Shh, a key morphogen for ventralization, in the ventral telencephalon. We observe PcG protein–mediated trimethylation of histone 3 at lysine-27 and binding of Ring1B at BMP and Wnt ligand genes specifically in the ventral region. Furthermore, forced activation of BMP or Wnt signaling represses Shh expression. Our results thus indicate that PcG proteins suppress BMP and Wnt signaling in a region-specific manner and thereby allow proper Shh expression and development of the ventral telencephalon.
OsChz1 acts as a histone chaperone in modulating chromatin organization and genome function in rice
Authors: Du Kangxi , Luo Qiang , Yin Liufan , Wu Jiabing , Liu Yuhao , Gan Jianhua , Dong Aiwu , Shen Wen-Hui
Published: November 2020

While the yeast Chz1 acts as a specific histone-chaperone for H2A.Z, functions of CHZ-domain proteins in multicellular eukaryotes remain obscure. Here, we report on the functional characterization of OsChz1, a sole CHZ-domain protein identified in rice. OsChz1 interacts with both the canonical H2A-H2B dimer and the variant H2A.Z-H2B dimer. Within crystal structure the C-terminal region of OsChz1 binds H2A-H2B via an acidic region, pointing to a previously unknown recognition mechanism. Knockout of OsChz1 leads to multiple plant developmental defects. At genome-wide level, loss of OsChz1 causes mis-regulations of thousands of genes and broad alterations of nucleosome occupancy as well as reductions of H2A.Z-enrichment. While OsChz1 associates with chromatin regions enriched of repressive histone marks (H3K27me3 and H3K4me2), its loss does not affect the genome landscape of DNA methylation. Taken together, it is emerging that OsChz1 functions as an important H2A/H2A.Z-H2B chaperone in dynamic regulation of chromatin for higher eukaryote development.
Insulator-to-conductor transition driven by the Rashba–Zeeman effect
Authors: Tao Lingling , Tsymbal Evgeny Y.
Published: November 2020

The Rashba effect has recently attracted great attention owing to emerging physical properties associated with it. The interplay between the Rashba effect and the Zeeman effect, being produced by the exchange field, is expected to broaden the range of these properties and even result in novel phenomena. Here we predict an insulator-to-conductor transition driven by the Rashba–Zeeman effect. We first illustrate this effect using a general Hamiltonian model and show that the insulator-to-conductor transition can be triggered under certain Rashba and exchange-field strengths. Then, we exemplify this phenomenon by considering an Ag2Te/Cr2O3 heterostructure, where the electronic structure of the Ag2Te monolayer is affected across the interface by the proximity effect of the Cr2O3 antiferromagnetic layer with well-defined surface magnetization. Based on first-principles calculations, we predict that such a system can be driven into either insulating or conducting phase, depending on the surface magnetization orientation of the Cr2O3 layer. Our results enrich the Rashba–Zeeman physics and provide useful guidelines for the realization of the insulator-to-conductor transition, which may be interesting for experimental verification.
A late Pleistocene dataset of Agulhas Current variability
Authors: Simon Margit H. , Ziegler Martin , Barker Stephen , van der Meer Marcel T. J. , Schouten Stefan , Hall Ian R.
Published: November 2020

The interocean transfer of thermocline water between the Indian and the Atlantic Oceans known as ‘Agulhas leakage’ is of global significance as it influences the Atlantic Meridional Overturning Circulation (AMOC) on different time scales. Variability in the Agulhas Current regime is key in shaping hydroclimate on the adjacent coastal areas of the African continent today as well as during past climates. However, the lack of long, continuous records from the proximal Agulhas Current region dating beyond the last glacial cycle prevents elucidation of its role in regional and wider global climate changes. This is the first continuous record of hydrographic variability (SST; δ18Osw) from the Agulhas Current core region spanning the past 270,000 years. The data set is analytical sound and provides a solid age model. As such, it can be used by paleoclimate scientists, archaeologists, and climate modelers to evaluate, for example, linkages between the Agulhas Current system and AMOC dynamics, as well as connections between ocean heat transport and Southern African climate change in the past and its impact on human evolution.
New insights into the application of pair distribution function studies to biogenic and synthetic hydroxyapatites
Authors: Arnold Emily L. , Keeble Dean S. , Greenwood Charlene , Rogers Keith D.
Published: November 2020

Biogenic and synthetic hydroxyapatites are confounding materials whose properties remain uncertain, even after years of study. Pair distribution function (PDF) analysis was applied to hydroxyapatites in the 1970’s and 1980’s, but this area of research has not taken full advantage of the relatively recent advances in synchrotron facilities. Here, synchrotron X-ray PDF analysis is compared to techniques commonly used to characterise hydroxyapatite (such as wide angle X-ray scattering, Fourier-transform infrared spectroscopy and thermogravimetric analysis) for a range of biogenic and synthetic hydroxyapatites with a wide range of carbonate substitution. Contributions to the pair distribution function from collagen, carbonate and finite crystallite size were examined through principal component analysis and comparison of PDFs. Noticeable contributions from collagen were observed in biogenic PDFs when compared to synthetic PDFs (namely r < 15 Å), consistent with simulated PDFs of collagen structures. Additionally, changes in local structure were observed for PDFs of synthetic hydroxyapatites with differing carbonate content, notably in features near 4 Å, 8 Å and 19 Å. Regression models were generated to predict carbonate substitution from peak position within the PDFs.
Neutrophil extracellular traps from healthy donors and HIV-1-infected individuals restrict HIV-1 production in macrophages
Authors: Mojoli Andrés , Gonçalves Barbara Simonson , Temerozo Jairo R. , Cister-Alves Bruno , Geddes Victor , Herlinger Alice , Aguiar Renato Santana , Pilotto José Henrique , Saraiva Elvira M. , Bou-Habib Dumith Chequer
Published: November 2020

Neutrophils release extracellular traps (NETs) after interaction with microorganisms and physiological or synthetic products. NETs consist of decondensed chromatin complexed with proteins, some of them with microbicidal properties. Because NETs can modulate the functioning of HIV-1 target cells, we aimed to verify whether they modify HIV-1 replication in macrophages. We found that exposure of HIV-1-infected macrophages to NETs resulted in significant inhibition of viral replication. The NET anti-HIV-1 action was independent of other soluble factors released by the activated neutrophils, but otherwise dependent on the molecular integrity of NETs, since NET-treatment with protease or DNase abolished this effect. NETs induced macrophage production of the anti-HIV-1 β-chemokines Rantes and MIP-1β, and reduced the levels of integrated HIV-1 DNA in the macrophage genome, which may explain the decreased virus production by infected macrophages. Moreover, the residual virions released by NET-treated HIV-1-infected macrophages lost infectivity. In addition, elevated levels of DNA-elastase complexes were detected in the plasma from HIV-1-infected individuals, and neutrophils from these patients released NETs, which also inhibited HIV-1 replication in in vitro infected macrophages. Our results reveal that NETs may function as an innate immunity mechanism able to restrain HIV-1 production in macrophages.
Chemoradiation impairs myofiber hypertrophic growth in a pediatric tumor model
Authors: Paris Nicole D. , Kallenbach Jacob G. , Bachman John F. , Blanc Roméo S. , Johnston Carl J. , Hernady Eric , Williams Jacqueline P. , Chakkalakal Joe V.
Published: November 2020

Pediatric cancer treatment often involves chemotherapy and radiation, where off-target effects can include skeletal muscle decline. The effect of such treatments on juvenile skeletal muscle growth has yet to be investigated. We employed a small animal irradiator to administer fractionated hindlimb irradiation to juvenile mice bearing implanted rhabdomyosarcoma (RMS) tumors. Hindlimb-targeted irradiation (3 × 8.2 Gy) of 4-week-old mice successfully eliminated RMS tumors implanted one week prior. After establishment of this preclinical model, a cohort of tumor-bearing mice were injected with the chemotherapeutic drug, vincristine, alone or in combination with fractionated irradiation (5 × 4.8 Gy). Single myofiber analysis of fast-contracting extensor digitorum longus (EDL) and slow-contracting soleus (SOL) muscles was conducted 3 weeks post-treatment. Although a reduction in myofiber size was apparent, EDL and SOL myonuclear number were differentially affected by juvenile irradiation and/or vincristine treatment. In contrast, a decrease in myonuclear domain (myofiber volume/myonucleus) was observed regardless of muscle or treatment. Thus, inhibition of myofiber hypertrophic growth is a consistent feature of pediatric cancer treatment.
Structures of the free and inhibitors-bound forms of bromelain and ananain from Ananas comosus stem and in vitro study of their cytotoxicity
Authors: Azarkan Mohamed , Maquoi Erik , Delbrassine François , Herman Raphael , M’Rabet Nasiha , Calvo Esposito Rafaèle , Charlier Paulette , Kerff Frédéric
Published: November 2020

The Ananascomosus stem extract is a complex mixture containing various cysteine ​​proteases of the C1A subfamily, such as bromelain and ananain. This mixture used for centuries in Chinese medicine, has several potential therapeutic applications as anti-cancer, anti-inflammatory and ecchymosis degradation agent. In the present work we determined the structures of bromelain and ananain, both in their free forms and in complex with the inhibitors E64 and TLCK. These structures combined with protease-substrate complexes modeling clearly identified the Glu68 as responsible for the high discrimination of bromelain in favor of substrates with positively charged residues at P2, and unveil the reasons for its weak inhibition by cystatins and E64. Our results with purified and fully active bromelain, ananain and papain show a strong reduction of cell proliferation with MDA-MB231 and A2058 cancer cell lines at a concentration of about 1 μM, control experiments clearly emphasizing the need for proteolytic activity. In contrast, while bromelain and ananain had a strong effect on the proliferation of the OCI-LY19 and HL-60 non-adherent cell lines, papain, the archetypal member of the C1A subfamily, had none. This indicates that, in this case, sequence/structure identity beyond the active site of bromelain and ananain is more important than substrate specificity.
Molecular insights into the mechanisms of susceptibility of Labeo rohita against oomycete Aphanomyces invadans
Authors: Pradhan P. K. , Verma Dev Kumar , Peruzza Luca , Gupta Shubham , Haq Syed Assim , Shubin Sergei V. , Morgan Kenton L. , Trusch Franziska , Mohindra Vindhya , Hauton Chris , van West Pieter , Sood Neeraj
Published: November 2020

Aphanomyces invadans, the causative agent of epizootic ulcerative syndrome, is one of the most destructive pathogens of freshwater fishes. To date, the disease has been reported from over 160 fish species in 20 countries and notably, this is the first non-salmonid disease that has resulted in major impacts globally. In particular, Indian major carps (IMCs) are highly susceptible to this disease. To increase our knowledge particularly with regards to host immune response against A. invadans infection in a susceptible host, the gene expression profile in head kidney of A. invadans-infected and control rohu, Labeo rohita was investigated using RNA sequencing. Time course analysis of RNA-Seq data revealed 5608 differentially expressed genes, involved among others in Antigen processing and presentation, Leukocyte transendothelial migration, IL-17 signaling, Chemokine signaling, C-type lectin receptor signaling and Toll-like receptor signaling pathways. In the affected pathways, a number of immune genes were found to be downregulated, suggesting an immune evasion strategy of A. invadans in establishing the infection. The information generated in this study offers first systematic mechanistic understanding of the host–pathogen interaction that might underpin the development of new management strategies for this economically devastating fish-pathogenic oomycete A. invadans.
Modifying the thickness, pore size, and composition of diatom frustule in Craspedostauros sp. with Al3+ ions
Authors: Soleimani Mohammad , Rutten Luco , Maddala Sai Prakash , Wu Hanglong , Eren E. Deniz , Mezari Brahim , Schreur-Piet Ingeborg , Friedrich Heiner , van Benthem Rolf A. T. M.
Published: November 2020

Diatoms are unicellular photosynthetic algae that produce a silica exoskeleton (frustule) which exposes a highly ordered nano to micro scale morphology. In recent years there has been a growing interest in modifying diatom frustules for technological applications. This is achieved by adding non-essential metals to the growth medium of diatoms which in turn modifies morphology, composition, and resulting properties of the frustule. Here, we investigate the frustule formation in diatom Craspedostauros sp., including changes to overall morphology, silica thickness, and composition, in the presence of Al3+ ions at different concentrations. Our results show that in the presence of Al3+ the total silica uptake from the growth medium increases, although a decrease in the growth rate is observed. This leads to a higher inorganic content per diatom resulting in a decreased pore diameter and a thicker frustule as evidenced by electron microscopy. Furthermore, 27Al solid-state NMR, FIB-SEM, and EDS results confirm that Al3+ becomes incorporated into the frustule during the silicification process, thus, improving hydrolysis resistance. This approach may be extended to a broad range of elements and diatom species towards the scalable production of silica materials with tunable hierarchical morphology and chemical composition.
Relationships between motor and cognitive functions and subsequent post-stroke mood disorders revealed by machine learning analysis
Authors: Hama Seiji , Yoshimura Kazumasa , Yanagawa Akiko , Shimonaga Koji , Furui Akira , Soh Zu , Nishino Shinya , Hirano Harutoyo , Yamawaki Shigeto , Tsuji Toshio
Published: November 2020

Mood disorders (e.g. depression, apathy, and anxiety) are often observed in stroke patients, exhibiting a negative impact on functional recovery associated with various physical disorders and cognitive dysfunction. Consequently, post-stroke symptoms are complex and difficult to understand. In this study, we aimed to clarify the cross-sectional relationship between mood disorders and motor/cognitive functions in stroke patients. An artificial neural network architecture was devised to predict three types of mood disorders from 36 evaluation indices obtained from functional, physical, and cognitive tests on 274 patients. The relationship between mood disorders and motor/cognitive functions were comprehensively analysed by performing input dimensionality reduction for the neural network. The receiver operating characteristic curve from the prediction exhibited a moderate to high area under the curve above 0.85. Moreover, the input dimensionality reduction retrieved the evaluation indices that are more strongly related to mood disorders. The analysis results suggest a stress threshold hypothesis, in which stroke-induced lesions promote stress vulnerability and may trigger mood disorders.
Complement C6 deficiency exacerbates pathophysiology after spinal cord injury
Authors: Su Diane , Hooshmand Mitra J. , Galvan Manuel D. , Nishi Rebecca A. , Cummings Brian J. , Anderson Aileen J.
Published: November 2020

Historically, the membrane attack complex, composed of complement components C5b-9, has been connected to lytic cell death and implicated in secondary injury after a CNS insult. However, studies to date have utilized either non-littermate control rat models, or mouse models that lack significant C5b-9 activity. To investigate what role C5b-9 plays in spinal cord injury and recovery, we generated littermate PVG C6 wildtype and deficient rats and tested functional and histological recovery after moderate contusion injury using the Infinite Horizon Impactor. We compare the effect of C6 deficiency on recovery of locomotor function and histological injury parameters in PVG rats under two conditions: (1) animals maintained as separate C6 WT and C6-D homozygous colonies; and (2) establishment of a heterozygous colony to generate C6 WT and C6-D littermate controls. The results suggest that maintenance of separate homozygous colonies is inadequate for testing the effect of C6 deficiency on locomotor and histological recovery after SCI, and highlight the importance of using littermate controls in studies involving genetic manipulation of the complement cascade.
Rice husk derived Aminated Silica for the efficient adsorption of different gases
Authors: Bakdash Rashed S. , Aljundi Isam. H. , Basheer Chanbasha , Abdulazeez Ismail
Published: November 2020

In this present work, we successfully prepared aminated silica (ASiO2) from rice husk ash (RHA) and functionalized with 3-aminopropyltriethoxysilane (APTES). Physical and chemical properties of the synthesized material were investigated by various techniques SEM–EDX, XPS, FTIR, TGA. The surface area of RHA was 223 m2/g, while for ASiO2 was 101 m2/g. Molecular level DFT calculations revealed that the functionalization of ASiO2 resulted in a significant decrease in the HOMO–LUMO energy gap, a reduction in hardness, and a consequent increase in charge transfer characteristics. The adsorption behavior at low pressure (1 atm.) of aminated silica on different gases CO2, CH4, H2, and N2 at temperatures 77, 273, 298 K was studied. The adsorption of hydrogen was reported for the first time on aminated silica with an excellent adsorption capacity of 1.2 mmol/g. The ASiO2 exhibited excellent performance in terms of gas separation in binary mixtures of CO2/CH4, CO2/N2 and CO2/H2 at 273, and 298 K, respectively. The catalyst further exhibits high stability during three cycles with less than 10% variation in the separation capacity.
Artificial intelligence application for rapid fabrication of size-tunable PLGA microparticles in microfluidics
Authors: Damiati Safa A. , Rossi Damiano , Joensson Haakan N. , Damiati Samar
Published: November 2020

In this study, synthetic polymeric particles were effectively fabricated by combining modern technologies of artificial intelligence (AI) and microfluidics. Because size uniformity is a key factor that significantly influences the stability of polymeric particles, therefore, this work aimed to establish a new AI application using machine learning technology for prediction of the size of poly(d,l-lactide-co-glycolide) (PLGA) microparticles produced by diverse microfluidic systems either in the form of single or multiple particles. Experimentally, the most effective factors for tuning droplet/particle sizes are PLGA concentrations and the flow rates of dispersed and aqueous phases in microfluidics. These factors were utilized to develop five different and simple in structure artificial neural network (ANN) models that are capable of predicting PLGA particle sizes produced by different microfluidic systems either individually or jointly merged. The systematic development of ANN models allowed ultimate construction of a single in silico model which consists of data for three different microfluidic systems. This ANN model eventually allowed rapid prediction of particle sizes produced using various microfluidic systems. This AI application offers a new platform for further rapid and economical exploration of polymer particles production in defined sizes for various applications including biomimetic studies, biomedicine, and pharmaceutics.
Protein-caged zinc porphyrin as a carbonic anhydrase mimic for carbon dioxide capture
Authors: Chi Haixia , Chen Han , Gong Kai , Wang Xiaoqiang , Zhang Youming
Published: November 2020

Zinc tetraphenylporphyrin (Zn-TPP) solubilized by GroEL protein cage was prepared as a supramolecular mimic of carbonic anhydrase (CA) for CO2 capture. It is shown that the soluble Zn-TPP-GroEL complex can be formed easily by detergent dialysis. The Zn-TPP/GroEL binding ratio was found to increase with their dialysis ratio until reaching the maximum of about 30 porphyrins per protein cage. Moreover, the complex showed hydrase activity that catalyzes the CO2 hydration in HCO3− and H+. It is further seen that the catalytic activity of Zn-TPP-GroEL was about one-half of that of a bovine CA at 25 °C. On the other hand, as the temperature was increased to 60 °C close to an industrial CO2 absorption temperature, the natural enzyme lost function while Zn-TPP-GroEL exhibited better catalytic performance indicative of a higher thermal stability. Finally, we demonstrate that the GroEL-solubilized Zn-TPP is able to accelerate the precipitation of CO2 in the form of CaCO3 and has better long-term performance than the bovine CA. Thus a new type of nano-caged system mimicking natural CAs for potential applications in carbon capture has been established.
Defectors’ intolerance of others promotes cooperation in the repeated public goods game with opting out
Authors: Křivan Vlastimil , Cressman Ross
Published: November 2020

The theoretical and experimental research on opting out (also called conditional dissociation) in social dilemmas has concentrated on the effect this behavior has on the level of cooperation when used against defectors. The intuition behind this emphasis is based on the common property of social dilemmas that individuals are worse off the more their opponents defect. However, this article shows clearly that other opting out mechanisms are better at increasing cooperative behavior. In fact, by analyzing the stable Nash equilibria for the repeated multi-player public goods game with opting out, our results provide a strong argument that the best opting out rule is one whereby the only groups that voluntarily stay together between rounds are those that are homogeneous (i.e., those groups that are either all cooperators or all defectors), when these groups stay together for enough rounds. This outcome emerges when defectors are completely intolerant of individuals who cooperate (e.g., defectors exhibit xenophobic behavior toward cooperators) and so opt out whenever their group has a cooperator in it. The strong preference by defectors to be with like-minded individuals causes all heterogeneous groups to disband after one round.
Ensemble description of the intrinsically disordered N-terminal domain of the Nipah virus P/V protein from combined NMR and SAXS
Authors: Schiavina Marco , Salladini Edoardo , Murrali Maria Grazia , Tria Giancarlo , Felli Isabella C. , Pierattelli Roberta , Longhi Sonia
Published: November 2020

Using SAXS and NMR spectroscopy, we herein provide a high-resolution description of the intrinsically disordered N-terminal domain (PNT, aa 1–406) shared by the Nipah virus (NiV) phosphoprotein (P) and V protein, two key players in viral genome replication and in evasion of the host innate immune response, respectively. The use of multidimensional NMR spectroscopy allowed us to assign as much as 91% of the residues of this intrinsically disordered domain whose size constitutes a technical challenge for NMR studies. Chemical shifts and nuclear relaxation measurements provide the picture of a highly flexible protein. The combination of SAXS and NMR information enabled the description of the conformational ensemble of the protein in solution. The present results, beyond providing an overall description of the conformational behavior of this intrinsically disordered region, also constitute an asset for obtaining atomistic information in future interaction studies with viral and/or cellular partners. The present study can thus be regarded as the starting point towards the design of inhibitors that by targeting crucial protein–protein interactions involving PNT might be instrumental to combat this deadly virus.
Entrainment of circadian rhythms of locomotor activity by ambient temperature cycles in the dromedary camel
Authors: Farsi Hicham , Achaâban Mohamed R. , Piro Mohammed , Bothorel Béatrice , Ouassat Mohammed , Challet Etienne , Pévet Paul , El Allali Khalid
Published: November 2020

In the dromedary camel, a well-adapted desert mammal, daily ambient temperature (Ta)-cycles have been shown to synchronize the central circadian clock. Such entrainment has been demonstrated by examining two circadian outputs, body temperature and melatonin rhythms. Locomotor activity (LA), another circadian output not yet investigated in the camel, may provide further information on such specific entrainment. To verify if daily LA is an endogenous rhythm and whether the desert Ta-cycle can entrain it, six dromedaries were first kept under total darkness and constant-Ta. Results showed that the LA rhythm free runs with a period of 24.8–24.9 h. After having verified that the light–dark cycle synchronizes LA, camels were subjected to a Ta-cycle with warmer temperatures during subjective days and cooler temperatures during subjective nights. Results showed that the free-running LA rhythm was entrained by the Ta-cycle with a period of exactly 24.0 h, while a 12 h Ta-cycle phase advance induced an inversion of the LA rhythm and advanced the acrophase by 9 h. Similarly, activity onset and offset were significantly advanced. All together, these results demonstrate that the Ta-cycle is a strong zeitgeber, able to entrain the camel LA rhythm, hence corroborating previous results concerning the Ta non-photic synchronization of the circadian master clock.
Validation of the BD FACSPresto system for the measurement of CD4 T-lymphocytes and hemoglobin concentration in HIV-negative and HIV-positive subjects
Authors: Lu Xiaofan , Sun Hanxiao , Li Haicong , Xia Wei , Wu Hao , Chen Daihong , Tan Meiyu , Yu Shijun , Zhang Tong , Sheng Huiming , Zhu Zhaoqin
Published: November 2020

This study aimed to compare the performance of the BD FACSPresto system with the conventional standard-of-care technologies for the measurement of absolute CD4 count (AbsCD4), CD4 percentage (CD4%) and total hemoglobin concentration (Hb) in capillary and venous blood samples of HIV-negative and HIV-positive subjects. A total of 1304 participants were included in this prospective cohort study. Both venous and capillary blood samples were analyzed using the BD FACSPresto system and the results were compared against the BD FACSCalibur for enumerating AbsCD4 and CD4% and Sysmex XT-4000i hematology analyzer for determining Hb levels. Method comparison studies were performed using Deming regression and Bland–Altman plots. The Deming regression analyses comparing the accuracy of the BD FACSPresto system with the reference standard technologies demonstrated a significant linear correlation between the AbsCD4, CD4%, and Hb values generated by the two platforms. The 95% CI of the slopes for AbsCD4, CD4%, and Hb levels were 0.94–0.99, 0.99–1.01 and 0.86–0.93, respectively (P < 0.001). Bland–Altman plots for AbsCD4, CD4%, and Hb levels demonstrated close agreement between the BD FACSPresto system and the reference standards for all study participants. The performance and accuracy of BD FACSPresto system was comparable to the reference standard technologies. The BD FACSPresto system can be used interchangeably with BD FACSCalibur platform for CD4 and Sysmex XT-4000i hematology analyzer for Hb concentrations in resource-limited settings thus, improving accessibility to point-of-care testing services.
Incidence and risk factors of vascular complications in people with impaired fasting glucose: a national cohort study in Korea
Authors: Yu Eun Sun , Hong Kwan , Chun Byung Chul
Published: November 2020

This study aimed to evaluate the risk of vascular complications of impaired fasting glucose (IFG). This population-based study included 425,608 participants from the National Health Screening Cohort in Korea in 2003 and 2004 who were followed-up until 2015. The participants were classified into normal, IFG, and diabetes groups based on fasting plasma glucose levels. Incidence rate (per 1000 person-year) was evaluated for the following vascular complications: cardiovascular (ischemic heart disease, cerebrovascular disease, arterial and capillary disease), renal, and retinal diseases. Hazard ratios (HR) of IFG for diabetes were estimated after adjusting for patient characteristics. Among the 88,330 IFG participants, the incidence of cardiovascular, chronic renal and retinal diseases were 11.52, 0.47, and 1.08 per 1000 person-years, respectively. Furthermore, IFG patients with a family history of diabetes, past history of hypertension, and high body mass index had significantly increased risk of vascular complications [adjusted HR, cardiovascular: 1.39 (95% CI 1.33–1.46); renal: 2.17 (95% CI 1.66–2.83); and retinal: 1.14 (95% CI 0.98–1.32)]. IFG patients have a substantial risk of cardiovascular, chronic renal and retinal diseases. Therefore, early preventative interventions are beneficial, especially for those with high-risk factors, in whom should emphasize on maintaining a healthy lifestyle, early screening and continuous follow-up.
Identification of critical genetic variants associated with metabolic phenotypes of the Japanese population
Authors: Koshiba Seizo , Motoike Ikuko N. , Saigusa Daisuke , Inoue Jin , Aoki Yuichi , Tadaka Shu , Shirota Matsuyuki , Katsuoka Fumiki , Tamiya Gen , Minegishi Naoko , Fuse Nobuo , Kinoshita Kengo , Yamamoto Masayuki
Published: November 2020

We performed a metabolome genome-wide association study for the Japanese population in the prospective cohort study of Tohoku Medical Megabank. By combining whole-genome sequencing and nontarget metabolome analyses, we identified a large number of novel associations between genetic variants and plasma metabolites. Of the identified metabolite-associated genes, approximately half have already been shown to be involved in various diseases. We identified metabolite-associated genes involved in the metabolism of xenobiotics, some of which are from intestinal microorganisms, indicating that the identified genetic variants also markedly influence the interaction between the host and symbiotic bacteria. We also identified five associations that appeared to be female-specific. A number of rare variants that influence metabolite levels were also found, and combinations of common and rare variants influenced the metabolite levels more profoundly. These results support our contention that metabolic phenotyping provides important insights into how genetic and environmental factors provoke human diseases.
A cosolvent surfactant mechanism affects polymer collapse in miscible good solvents
Authors: Bharadwaj Swaminath , Nayar Divya , Dalgicdir Cahit , van der Vegt Nico F. A.
Published: November 2020

The coil–globule transition of aqueous polymers is of profound significance in understanding the structure and function of responsive soft matter. In particular, the remarkable effect of amphiphilic cosolvents (e.g., alcohols) that leads to both swelling and collapse of stimuli-responsive polymers has been hotly debated in the literature, often with contradictory mechanisms proposed. Using molecular dynamics simulations, we herein demonstrate that alcohols reduce the free energy cost of creating a repulsive polymer–solvent interface via a surfactant-like mechanism which surprisingly drives polymer collapse at low alcohol concentrations. This hitherto neglected role of interfacial solvation thermodynamics is common to all coil–globule transitions, and rationalizes the experimentally observed effects of higher alcohols and polymer molecular weight on the coil-to-globule transition of thermoresponsive polymers. Polymer–(co)solvent attractive interactions reinforce or compensate this mechanism and it is this interplay which drives polymer swelling or collapse.
Prediction of structure and cation ordering in an ordered normal-inverse double spinel
Authors: Pilania Ghanshyam , Kocevski Vancho , Valdez James A. , Kreller Cortney R. , Uberuaga Blas P.
Published: November 2020

Spinels represent an important class of technologically relevant materials, used in diverse applications ranging from dielectrics, sensors and energy materials. While solid solutions combining two “single spinels” have been explored in a number of past studies, no ordered “double” spinels have been reported. Based on our first principles computations, here we predict the existence of such a double spinel compound MgAlGaO4, formed by an equimolar mixing of MgAl2O4normal and MgGa2O4inverse spinels. After studying the details of its atomic and electronic structure, we use a cluster expansion based effective Hamiltonian approach with Monte Carlo simulations to study the thermodynamic behavior and cation distribution as a function of temperature. Our simulations provide strong evidence for short-ranged cation order in the double spinel structure, even at significantly elevated temperatures. Finally, an attempt was made to synthesize the predicted double spinel compound. Energy Dispersive X-ray Spectrometry and X-ray diffraction Rietveld refinements were performed to characterize the single-phase chemical composition and local configurational environments, which showed a favorable agreement with the theoretical predictions. These findings suggest that a much larger number of compounds can potentially be realized within this chemical space, opening new avenues for the design of spinel-structured materials with tailored functionality.
A 3D tissue model-on-a-chip for studying the effects of human senescent fibroblasts on blood vessels
Authors: Pauty Joris , Nakano Shizuka , Usuba Ryo , Nakajima Tadaaki , Johmura Yoshikazu , Omori Satotaka , Sakamoto Naoya , Kikuchi Akihiko , Nakanishi Makoto , Matsunaga Yukiko T.
Published: November 2020

Senescent cells modify their environment and cause tissue aging that leads to organ dysfunction. Developing strategies for healthy aging rises a need for in vitro models that enables to study senescence and senotherapeutics at a tissue level.
Continuous flow fabrication of Fmoc-cysteine based nanobowl infused core–shell like microstructures for pH switchable on-demand anti-cancer drug delivery
Authors: Chibh Sonika , Katoch Vibhav , Kour Avneet , Khanam Farheen , Yadav Amit Singh , Singh Manish , Kundu Gopal C. , Prakash Bhanu , Panda Jiban Jyoti
Published: November 2020

pH responsive core–shell nanobowl-microstructures (NB-shells) as novel and exciting platforms for stimuli activated drug delivery applications.
One-for-all intelligent core–shell nanoparticles for tumor-specific photothermal–chemodynamic synergistic therapy
Authors: Wu Hongshuai , Gu Dihai , Xia Shengjin , Chen Fanghui , You Chaoqun , Sun Baiwang
Published: November 2020

This study reports an intelligent targeted therapy platform based on Fe3+- and GOx-containing core–shell nanoparticles for NIR-induced PTT and pH-activated and NIR-reinforced CDT.
Molecular designs for expanding the limits of ultralong C–C bonds and ultrashort H⋯H non-bonded contacts
Authors: Mandal Nilangshu , Datta Ayan
Published: November 2020

Dispersion-corrected DFT calculations provide a library of new molecules containing rare examples of ultralong C–C bonds and ultrashort H⋯H contacts.
RbB3O4F2: a rubidium fluorooxoborate with an unprecedented [B3O5F2]3− functionalized unit and a large birefringence
Authors: Lu Zixiu , Zhang Fangfang , Tudi Abudukadi , Yang Zhihua , Pan Shilie
Published: November 2020

A promising DUV birefringent material, RbB3O4F2, presents novel [B3O4F2]− chains formed by the unprecedented [B3O5F2]3− fundamental building block.
Attosecond laser control of photoelectron angular distributions in XUV-induced ionization of H2
Authors: Bello Roger Y. , Martín Fernando , Palacios Alicia
Published: November 2020

An attosecond XUV pump-IR probe scheme is used to exert control on H2 ionization dynamics and induce preferential electron ejection directions.
Ultra high molecular weight polyethylene with incorporated crystal violet and gold nanoclusters is antimicrobial in low intensity light and in the dark
Authors: Wu Ke , Wu Gaowei , MacRobert Alexander J. , Allan Elaine , Gavriilidis Asterios , Parkin Ivan P.
Published: November 2020

Antibiotics lose their effectiveness over time due to antimicrobial resistance.
Towards a RIOK2 chemical probe: cellular potency improvement of a selective 2-(acylamino)pyridine series
Authors: Wang Christopher B. , Lorente-Macías Álvaro , Wells Carrow , Pickett Julie E. , Picado Alfredo , Zuercher William J. , Axtman Alison D.
Published: November 2020

Modification of the 2-(acylamino)pyridine scaffold led to the identification of structure–activity relationships that improve RIOK2 cellular potency and maintain its selectivity.
Polyhedral plasmonic nanoclusters through multi-step colloidal chemistry
Authors: Tanjeem Nabila , Chomette Cyril , Schade Nicholas B. , Ravaine Serge , Duguet Etienne , Tréguer-Delapierre Mona , Manoharan Vinothan N.
Published: November 2020

A high-yield chemical synthesis approach to making metal-coated nanoclusters results in precisely controlled plasmonic properties.
Photoresponsive porous materials
Authors: Danowski Wojciech , van Leeuwen Thomas , Browne Wesley R. , Feringa Ben L.
Published: November 2020

Integration of molecular photoswitches in porous materials i.e. MOFs, COFs, PAFs provides responsive materials with a variety of functions ranging from switchable gas adsorption to macroscopic actuation.