bluuebunny/crossref_metadata_2025 huggingface dataset:
Self-induced mechanical stress can trigger biofilm formation in uropathogenic Escherichia coli
Authors: Chu Eric K. , Kilic Onur , Cho Hojung , Groisman Alex , Levchenko Andre
Published: October 2018

Bacterial biofilms represent an important medical problem; however, the mechanisms of the onset of biofilm formation are poorly understood. Here, using new controlled methods allowing high-throughput and reproducible biofilm growth, we show that biofilm formation is linked to self-imposed mechanical stress. In growing uropathogenic Escherichia coli colonies, we report that mechanical stress can initially emerge from the physical stress accompanying colony confinement within micro-cavities or hydrogel environments reminiscent of the cytosol of host cells. Biofilm formation can then be enhanced by a nutrient access-modulated feedback loop, in which biofilm matrix deposition can be particularly high in areas of increased mechanical and biological stress, with the deposited matrix further enhancing the stress levels. This feedback regulation can lead to adaptive and diverse biofilm formation guided by the environmental stresses. Our results suggest previously unappreciated mechanisms of the onset and progression of biofilm growth.
Copy number load predicts outcome of metastatic colorectal cancer patients receiving bevacizumab combination therapy
Authors: Smeets Dominiek , Miller Ian S. , O’Connor Darran P. , Das Sudipto , Moran Bruce , Boeckx Bram , Gaiser Timo , Betge Johannes , Barat Ana , Klinger Rut , van Grieken Nicole C. T. , Cremolini Chiara , Prenen Hans , Mazzone Massimiliano , Depreeuw Jeroen , Bacon Orna , Fender Bozena , Brady Joseph , Hennessy Bryan T. , McNamara Deborah A. , Kay Elaine , Verheul Henk M. , Maarten Neerincx , Gallagher William M. , Murphy Verena , Prehn Jochen H. M. , Koopman Miriam , Punt Cornelis J. A. , Loupakis Fotios , Ebert Matthias P. A. , Ylstra Bauke , Lambrechts Diether , Byrne Annette T.
Published: October 2018

Increased copy number alterations (CNAs) indicative of chromosomal instability (CIN) have been associated with poor cancer outcome. Here, we study CNAs as potential biomarkers of bevacizumab (BVZ) response in metastatic colorectal cancer (mCRC). We cluster 409 mCRCs in three subclusters characterized by different degrees of CIN. Tumors belonging to intermediate-to-high instability clusters have improved outcome following chemotherapy plus BVZ versus chemotherapy alone. In contrast, low instability tumors, which amongst others consist of POLE-mutated and microsatellite-instable tumors, derive no further benefit from BVZ. This is confirmed in 81 mCRC tumors from the phase 2 MoMa study involving BVZ. CNA clusters overlap with CRC consensus molecular subtypes (CMS); CMS2/4 xenografts correspond to intermediate-to-high instability clusters and respond to FOLFOX chemotherapy plus mouse avastin (B20), while CMS1/3 xenografts match with low instability clusters and fail to respond. Overall, we identify copy number load as a novel potential predictive biomarker of BVZ combination therapy.
Nickel nanoparticles set a new record of strength
Authors: Sharma A. , Hickman J. , Gazit N. , Rabkin E. , Mishin Y.
Published: October 2018

Material objects with micrometer or nanometer dimensions can exhibit much higher strength than macroscopic objects, but this strength rarely approaches the maximum theoretical strength of the material. Here, we demonstrate that faceted single-crystalline nickel (Ni) nanoparticles exhibit an ultrahigh compressive strength (up to 34 GPa) unprecedented for metallic materials. This strength matches the available estimates of Ni theoretical strength. Three factors are responsible for this record-high strength: the large Ni shear modulus, the smooth edges and corners of the nanoparticles, and the thin oxide layer on the particle surface. This finding is supported by molecular dynamics simulations that closely mimic the experimental conditions, which show that the mechanical failure of the strongest particles is triggered by homogeneous nucleation of dislocation loops inside the particle. The nucleation of a stable loop is preceded by multiple nucleation attempts accompanied by unusually large local atomic displacements caused by thermal fluctuations.
High-performance nanomaterials formed by rigid yet extensible cyclic β-peptide polymers
Authors: Fears Kenan P. , Kolel-Veetil Manoj K. , Barlow Daniel E. , Bernstein Noam , So Christopher R. , Wahl Kathryn J. , Li Xianfeng , Kulp John L. , Latour Robert A. , Clark Thomas D.
Published: October 2018

Organisms have evolved biomaterials with an extraordinary convergence of high mechanical strength, toughness, and elasticity. In contrast, synthetic materials excel in stiffness or extensibility, and a combination of the two is necessary to exceed the performance of natural biomaterials. We bridge this materials property gap through the side-chain-to-side-chain polymerization of cyclic β-peptide rings. Due to their strong dipole moments, the rings self-assemble into rigid nanorods, stabilized by hydrogen bonds. Displayed amines serve as functionalization sites, or, if protonated, force the polymer to adopt an unfolded conformation. This molecular design enhances the processability and extensibility of the biopolymer. Molecular dynamics simulations predict stick-slip deformations dissipate energy at large strains, thereby, yielding toughness values greater than natural silks. Moreover, the synthesis route can be adapted to alter the dimensions and displayed chemistries of nanomaterials with mechanical properties that rival nature.
Aberrant expression of CITED2 promotes prostate cancer metastasis by activating the nucleolin-AKT pathway
Authors: Shin Seung-Hyun , Lee Ga Young , Lee Mingyu , Kang Jengmin , Shin Hyun-Woo , Chun Yang-Sook , Park Jong-Wan
Published: October 2018

Despite many efforts to develop hormone therapy and chemotherapy, no effective strategy to suppress prostate cancer metastasis has been established because the metastasis is not well understood. We here investigate a role of CBP/p300-interacting transactivator with E/D-rich carboxy-terminal domain-2 (CITED2) in prostate cancer metastasis. CITED2 is highly expressed in metastatic prostate cancer, and its expression is correlated with poor survival. The CITED2 gene is highly activated by ETS-related gene that is overexpressed due to chromosomal translocation. CITED2 acts as a molecular chaperone to guide PRMT5 and p300 to nucleolin, thereby activating nucleolin. Informatics and experimental data suggest that the CITED2–nucleolin axis is involved in prostate cancer metastasis. This axis stimulates cell migration through the epithelial–mesenchymal transition and promotes cancer metastasis in a xenograft mouse model. Our results suggest that CITED2 plays a metastasis-promoting role in prostate cancer and thus could be a target for preventing prostate cancer metastasis.
Publisher Correction: Exosomes maintain cellular homeostasis by excreting harmful DNA from cells
Authors: Takahashi Akiko , Okada Ryo , Nagao Koji , Kawamata Yuka , Hanyu Aki , Yoshimoto Shin , Takasugi Masaki , Watanabe Sugiko , Kanemaki Masato T. , Obuse Chikashi , Hara Eiji
Published: October 2018

This Article contains errors in Fig. 4. In panel d, the lanes of the western blot should have been labeled ‘1.05’,‘1.06, ‘1.09’, ‘1.11’ ‘1.13’, ‘1.16’, ‘1.19’, ‘1.22’, ‘1.24’, ‘1.25’. The correct version of Figure 4 appears in the associated Publisher Correction.
Orthogonal programming of heterogeneous micro-mechano-environments and geometries in three-dimensional bio-stereolithography
Authors: Yin Hang , Ding Yonghui , Zhai Yao , Tan Wei , Yin Xiaobo
Published: October 2018

Engineering heterogeneous micro-mechano-microenvironments of extracellular matrix is of great interest in tissue engineering, but spatial control over mechanical heterogeneity in three dimensions is still challenging given the fact that geometry and stiffness are inherently intertwined in fabrication. Here, we develop a layer-by-layer three-dimensional (3D) printing paradigm which achieves orthogonal control of stiffness and geometry by capitalizing on the conventionally adverse effect of oxygen inhibition on free-radical polymerization. Controlled oxygen permeation and inhibition result in photo-cured hydrogel layers with thicknesses only weakly dependent to the ultraviolet exposure dosage. The dosage is instead leveraged to program the crosslink density and stiffness of the cured structures. The programmable stiffness spans nearly an order of magnitude (E ~ 2–15 kPa) within the physiologically relevant range. We further demonstrate that extracellular matrices with programmed micro-mechano-environments can dictate 3D cellular organization, enabling in vitro tissue reconstruction.
Thermal and electrical signatures of a hydrodynamic electron fluid in tungsten diphosphide
Authors: Gooth J. , Menges F. , Kumar N. , Süβ V. , Shekhar C. , Sun Y. , Drechsler U. , Zierold R. , Felser C. , Gotsmann B.
Published: October 2018

In stark contrast to ordinary metals, in materials in which electrons strongly interact with each other or with phonons, electron transport is thought to resemble the flow of viscous fluids. Despite their differences, it is predicted that transport in both conventional and correlated materials is fundamentally limited by the uncertainty principle applied to energy dissipation. Here we report the observation of experimental signatures of hydrodynamic electron flow in the Weyl semimetal tungsten diphosphide. Using thermal and magneto-electric transport experiments, we find indications of the transition from a conventional metallic state at higher temperatures to a hydrodynamic electron fluid below 20 K. The hydrodynamic regime is characterized by a viscosity-induced dependence of the electrical resistivity on the sample width and by a strong violation of the Wiedemann–Franz law. Following the uncertainty principle, both electrical and thermal transport are bound by the quantum indeterminacy, independent of the underlying transport regime.
Dynamic intercellular transport modulates the spatial patterning of differentiation during early neural commitment
Authors: Glen Chad M. , McDevitt Todd C. , Kemp Melissa L.
Published: October 2018

The initiation of heterogeneity within a population of phenotypically identical progenitors is a critical event for the onset of morphogenesis and differentiation patterning. Gap junction communication within multicellular systems produces complex networks of intercellular connectivity that result in heterogeneous distributions of intracellular signaling molecules. In this study, we investigate emergent systems-level behavior of the intercellular network within embryonic stem cell (ESC) populations and corresponding spatial organization during early neural differentiation. An agent-based model incorporates experimentally-determined parameters to yield complex transport networks for delivery of pro-differentiation cues between neighboring cells, reproducing the morphogenic trajectories during retinoic acid–accelerated mouse ESC differentiation. Furthermore, the model correctly predicts the delayed differentiation and preserved spatial features of the morphogenic trajectory that occurs in response to intercellular perturbation. These findings suggest an integral role of gap junction communication in the temporal coordination of emergent patterning during early differentiation and neural commitment of pluripotent stem cells.
Diverse definitions of the early course of schizophrenia—a targeted literature review
Authors: Newton Richard , Rouleau Alice , Nylander Anna-Greta , Loze Jean-Yves , Resemann Henrike K. , Steeves Sara , Crespo-Facorro Benedicto
Published: October 2018

Schizophrenia is a debilitating psychiatric disorder and patients experience significant comorbidity, especially cognitive and psychosocial deficits, already at the onset of disease. Previous research suggests that treatment during the earlier stages of disease reduces disease burden, and that a longer time of untreated psychosis has a negative impact on treatment outcomes. A targeted literature review was conducted to gain insight into the definitions currently used to describe patients with a recent diagnosis of schizophrenia in the early course of disease (‘early’ schizophrenia). A total of 483 relevant English-language publications of clinical guidelines and studies were identified for inclusion after searches of MEDLINE, MEDLINE In-Process, relevant clinical trial databases and Google for records published between January 2005 and October 2015. The extracted data revealed a wide variety of terminology and definitions used to describe patients with ‘early’ or ‘recent-onset’ schizophrenia, with no apparent consensus. The most commonly used criteria to define patients with early schizophrenia included experience of their first episode of schizophrenia or disease duration of less than 1, 2 or 5 years. These varied definitions likely result in substantial disparities of patient populations between studies and variable population heterogeneity. Better agreement on the definition of early schizophrenia could aid interpretation and comparison of studies in this patient population and consensus on definitions should allow for better identification and management of schizophrenia patients in the early course of their disease.
Author Correction: A Multiwell-Based Detection Platform with Integrated PDMS Concentrators for Rapid Multiplexed Enzymatic Assays
Authors: Wei Xi , Do Vu Q. , Pham Sang V. , Martins Diogo , Song Yong-Ak
Published: October 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.
The Quantum Mechanics of a Rolling Molecular “Nanocar”
Authors: Fernandez Oscar E. , Radhakrishnan Mala L.
Published: October 2018

We formulate a mathematical model of a rolling “molecular wheelbarrow”—a two-wheeled nanoscale molecular machine—informed by experiments on molecular machines recently synthesized in labs. The model is a nonholonomic system (briefly, a system with non-integrable velocity constraints), for which no general quantization procedure exists. Nonetheless, we successfully embed the system in a Hamiltonian one and then quantize the result using geometric quantization and other tools; we extract from the result the quantum mechanics of the molecular wheelbarrow, and derive explicit formulae for the quantized energy spectrum. We also study a few variants of our model, some of which ignore the model’s nonholonomic constraints. We show that these variants have different quantum energy spectra, indicating that in such systems one should not ignore the nonholonomic constraints, since they alter in a non-trivial way the energy spectrum of the molecule.
Single-mode, high-power, mid-infrared, quantum cascade laser phased arrays
Authors: Zhou Wenjia , Wu Donghai , Lu Quan-Yong , Slivken Steven , Razeghi Manijeh
Published: October 2018

We demonstrate single-mode, 16-channel, optical phased arrays based on quantum cascade laser technology, with emission wavelengths around 4.8 µm. The integrated device consists of a distributed feedback seed section, a highly-efficient tree array multi-mode interferometer power splitter, and a 16-channel amplifier array with a 4° angled facet termination. With a single layer Y2O3 coating, the angled facet reflectivity is estimated to be less than 0.1% for suppressing amplifier self-lasing. A peak output power of 30 W is achieved with an emission spectrum narrower than 11 nm and a side mode suppression ratio over 25 dB. Far field distribution measurement result indicates a uniform phase distribution across the array output. Using the same phased array architecture, we also demonstrate single-mode 3.8 µm QCL amplifier arrays with up to 20 W output power.
Epidemiology, microbiology and therapeutic consequences of chronic osteomyelitis in northern China: A retrospective analysis of 255 Patients
Authors: Ma Xianzhi , Han Shengshou , Ma Jun , Chen Xiaotao , Bai Wenbin , Yan Wenqi , Wang Kai
Published: October 2018

The study aimed to explore the epidemiology and clinical characteristics of chronic osteomyelitis observed in a northern China hospital. Clinical data of 255 patients with chronic osteomyelitis from January 2007 to January 2014 were collected and analyzed, including general information, disease data, treatment and follow-up data. Chronic osteomyelitis is more common in males and in the age group from 41–50 years of age. Common infection sites are the femur, tibiofibular, and hip joint. More g+ than g- bacterial infections were observed, with S. aureus the most commonly observed pathogenic organism. The positive detection rate from debridement bacterial culture is 75.6%. The detection rate when five samples are sent for bacterial culture is 90.6%, with pathogenic bacteria identified in 82.8% of cases. The two-stage debridement method (87.0%) has higher first curative rate than the one-stage debridement method (71.2%). To improve detection rate using bacterial culture, at least five samples are recommended. Treatment of chronic osteomyelitis with two-stage debridement, plus antibiotic-loaded polymethylmethacrylate (PMMA) beads provided good clinical results in this study and is therefore recommended.
Aromatic thermosetting copolyester bionanocomposites as reconfigurable bone substitute materials: Interfacial interactions between reinforcement particles and polymer network
Authors: Bakir Mete , Meyer Jacob L. , Sutrisno Andre , Economy James , Jasiuk Iwona
Published: October 2018

Development of porous materials consisting of polymer host matrix enriched with bioactive ceramic particles that can initiate the reproduction of cellular organisms while maintaining in vivo mechanical reliability is a long-standing challenge for synthetic bone substitutes. We present hydroxyapatite (HA) reinforced aromatic thermosetting copolyester (ATSP) matrix bionanocomposite as a potential reconfigurable bone replacement material. The nanocomposite is fabricated by solid-state mixing a matching set of precursor oligomers with biocompatible pristine HA particles. During endothermic condensation polymerization reaction, the constituent oligomers form a mechanochemically robust crosslinked aromatic backbone while incorporating the HAs into a self-generated cellular structure. The morphological analysis demonstrates near-homogenous distributions of the pristine HAs within the matrix. The HAs behave as a crack-arrester which promotes a more deformation-tolerant formation with relatively enhanced material toughness. Chain relaxation dynamics of the nanocomposite matrix during glass transition is modified via HA-induced segmental immobilization. Chemical characterization of the polymer backbone composition reveals the presence of a hydrogen-advanced covalent interfacial coupling mechanism between the HAs and ATSP matrix. This report lays the groundwork for further studies on aromatic thermosetting copolyester matrix bionanocomposites which may find applications in various artificial bone needs.
Real-time Brain Tumor imaging with endogenous fluorophores: a diagnosis proof-of-concept study on fresh human samples
Authors: Poulon Fanny , Pallud Johan , Varlet Pascale , Zanello Marc , Chretien Fabrice , Dezamis Edouard , Abi-Lahoud Georges , Nataf François , Turak Baris , Devaux Bertrand , Abi Haidar Darine
Published: October 2018

The primary line of therapy for high-grade brain tumor is surgical resection, however, identifying tumor margins in vivo remains a major challenge. Despite the progress in computer-assisted imaging techniques, biopsy analysis remains the standard diagnostic tool when it comes to delineating tumor margins. Our group aims to answer this challenge by exploiting optical imaging of endogenous fluorescence in order to provide a reliable and reproducible diagnosis close to neuropathology. In this study, we first establish the ability of two-photon microscopy (TPM) to discriminate normal brain tissue from glioblastomas and brain metastasis using the endogenous fluorescence response of fresh human brain sample. Two-photon fluorescence images were compared to gold standard neuropathology. “Blind” diagnosis realized by a neuropathologist on a group of TPM images show a good sensitivity, 100%, and specificity, 50% to discriminate non tumoral brain tissue versus glioblastoma or brain metastasis. Quantitative analysis on spectral and fluorescence lifetime measurements resulted in building a scoring system to discriminate brain tissue samples.
Novel multiplex PCR-SSP method for centromeric KIR allele discrimination
Authors: Le Luduec Jean-Benoît , Kudva Anupa , Boudreau Jeanette E. , Hsu Katharine C.
Published: October 2018

Allelic diversity of the KIR2DL receptors drive differential expression and ligand-binding affinities that impact natural killer cell function and patient outcomes for diverse cancers. We have developed a global intermediate resolution amplification-refractory mutation system (ARMS) PCR-SSP method for distinguishing functionally relevant subgroups of the KIR2DL receptors, as defined by phylogenetic study of the protein sequences. Use of the ARMS design makes the method reliable and usable as a kit, with all reactions utilizing the same conditions. Six reactions define six subgroups of KIR2DL1; four reactions define three subgroups of KIR2DL2; and five reactions define four subgroups of KIR2DL3. Using KIR allele data from a cohort of 426 European-Americans, we identified the most common KIR2DL subtypes and developed the high-throughput PCR-based methodology, which was validated on a separate cohort of 260 healthy donors. Linkage disequilibrium analysis between the different KIR2DL alleles revealed that seven allelic combinations represent more than 95% of the observed population genotypes for KIR2DL1/L2/L3. In summary, our findings enable rapid typing of the most common KIR2DL receptor subtypes, allowing more accurate prediction of co-inheritance and providing a useful tool for the discrimination of observed differences in surface expression and effector function among NK cells exhibiting disparate KIR2DL allotypes.
Structural insights into pro-aggregation effects of C. elegans CRAM-1 and its human ortholog SERF2
Authors: Balasubramaniam Meenakshisundaram , Ayyadevara Srinivas , Shmookler Reis Robert J.
Published: October 2018

Toxic protein aggregates are key features of progressive neurodegenerative diseases. In addition to “seed” proteins diagnostic for each neuropathy (e.g., Aβ1–42 and tau in Alzheimer’s disease), aggregates contain numerous other proteins, many of which are common to aggregates from diverse diseases. We reported that CRAM-1, discovered in insoluble aggregates of C. elegans expressing Q40::YFP, blocks proteasomal degradation of ubiquitinated proteins and thus promotes aggregation. We now show that CRAM-1 contains three α-helical segments forming a UBA-like domain, structurally similar to those of mammalian adaptor proteins (e.g. RAD23, SQSTM1/p62) that shuttle ubiquitinated cargos to proteasomes or autophagosomes for degradation. Molecular modeling indicates that CRAM-1, through this UBA-like domain, can form tight complexes with mono- and di-ubiquitin and may thus prevent tagged proteins from interacting with adaptor/shuttle proteins required for degradation. A human ortholog of CRAM-1, SERF2 (also largely disordered), promotes aggregation in SH-SY5Y-APPSw human neuroblastoma cells, since SERF2 knockdown protects these cells from amyloid formation. Atomistic molecular-dynamic simulations predict spontaneous unfolding of SERF2, and computational large-scale protein-protein interactions predict its stable binding to ubiquitins. SERF2 is also predicted to bind to most proteins screened at random, although with lower average stability than to ubiquitins, suggesting roles in aggregation initiation and/or progression.
Alteration of Serum Free Fatty Acids are Indicators for Progression of Pre-leukaemia Diseases to Leukaemia
Authors: Khalid Ayesha , Siddiqui Amna Jabbar , Huang Jian-Hua , Shamsi Tahir , Musharraf Syed Ghulam
Published: October 2018

Acute Leukaemia (AL) is a neoplasm of WBCs (white blood cells). Being an important class of metabolites, alteration in free fatty acids (FFAs) levels play a key role in cancer development and progression. As they involve in cell signaling, maintain membrane integrity, regulate homeostasis and effect cell and tissue functions. Considering this fact, a comprehensive analysis of FFAs was conducted to monitor their alteration in AL, pre-leukaemic diseases and healthy control. Fifteen FFAs were analyzed in 179 serum samples of myelodysplastic syndrome (MDS), aplastic anemia (APA), acute lymphoblastic leukaemia (ALL), acute myeloid leukaemia (AML) and healthy control using gas chromatography-multiple reaction monitoring-mass spectrometry (GC-MRM-MS). A multivariate statistical method of random forest (RF) was employed for chemometric analysis. Serum level of two FFAs including C18:0 and C14:0 were found discriminative among all five groups, and between ALL and AML, respectively. Moreover, C14:0 was identified as differentiated FFAs for systematic progression of pre-leukaemic conditions towards AML. C16:0 came as discriminated FFAs between APA and MDS/AML. Over all it was identified that FFAs profile not only become altered in leukaemia but also in pre-leukaemic diseases.
First assessment of the comparative toxicity of ivermectin and moxidectin in adult dung beetles: Sub-lethal symptoms and pre-lethal consequences
Authors: Verdú José R. , Cortez Vieyle , Martinez-Pinna Juan , Ortiz Antonio J. , Lumaret Jean-Pierre , Lobo Jorge M. , Sánchez-Piñero Francisco , Numa Catherine
Published: October 2018

Among macrocyclic lactones (ML), ivermectin (IVM) and moxidectin (MOX) potentially affect all Ecdysozoan species, with dung beetles being particularly sensitive. The comparative effects of IVM and MOX on adult dung beetles were assessed for the first time to determine both the physiological sub-lethal symptoms and pre-lethal consequences. Inhibition of antennal response and ataxia were tested as two intuitive and ecologically relevant parameters by obtaining the lowest observed effect concentration (LOEC) values and interpolating other relevant toxicity thresholds derived from concentration-response curves (IC50, as the concentration of each ML where the antennal response is inhibited by half; and pLC50, as the quantity of ingested ML where partial paralysis was observed by half of treated individuals) from concentration-response curves. Both sub-lethal and pre-lethal symptoms obtained in this study coincided in that IVM was six times more toxic than MOX for adult dung beetles. Values of LOEC, IC50 and pLC50 obtained for IVM and MOX evaluated in an environmental context indicate that MOX, despite needing more time for its elimination in the faeces, would be half as harmful to dung beetles as IVM. This approach will be valuable to clarify the real impact of MLs on dung beetle health and to avoid the subsequent environmental consequences.
Phenology determines the robustness of plant–pollinator networks
Authors: Ramos–Jiliberto Rodrigo , Moisset de Espanés Pablo , Franco–Cisterna Mauricio , Petanidou Theodora , Vázquez Diego P.
Published: October 2018

Plant–pollinator systems are essential for ecosystem functioning, which calls for an understanding of the determinants of their robustness to environmental threats. Previous studies considering such robustness have focused mostly on species’ connectivity properties, particularly their degree. We hypothesized that species’ phenological attributes are at least as important as degree as determinants of network robustness. To test this, we combined dynamic modeling, computer simulation and analysis of data from 12 plant–pollinator networks with detailed information of topology of interactions as well as species’ phenology of plant flowering and pollinator emergence. We found that phenological attributes are strong determinants of network robustness, a result consistent across the networks studied. Plant species persistence was most sensitive to increased larval mortality of pollinators that start earlier or finish later in the season. Pollinator persistence was especially sensitive to decreased visitation rates and increased larval mortality of specialists. Our findings suggest that seasonality of climatic events and anthropic impacts such as the release of pollutants is critical for the future integrity of terrestrial biodiversity.
Fiber-bundle illumination: realizing high-degree time-multiplexed multifocal multiphoton microscopy with simplicity
Authors: Yu Jiun-Yann , Kim Sunduck , Shim Young Bo , Holland Daniel B. , Allodi Marco A. , Yeh Chao-Yuan , Blake Geoffrey A. , Han Young-Geun , Guo Chin-Lin
Published: October 2018

High-degree time-multiplexed multifocal multiphoton microscopy was expected to provide a facile path to scanningless optical-sectioning and the fast imaging of dynamic three-dimensional biological systems. However, physical constraints on typical time multiplexing devices, arising from diffraction in the free-space propagation of light waves, lead to significant manufacturing difficulties and have prevented the experimental realization of high-degree time multiplexing. To resolve this issue, we have developed a novel method using optical fiber bundles of various lengths to confine the diffraction of propagating light waves and to create a time multiplexing effect. Through this method, we experimentally demonstrate the highest degree of time multiplexing ever achieved in multifocal multiphoton microscopy (~50 times larger than conventional approaches), and hence the potential of using simply-manufactured devices for scanningless optical sectioning of biological systems.
Empagliflozin Ammeliorates High Glucose Induced-Cardiac Dysfuntion in Human iPSC-Derived Cardiomyocytes
Authors: Ng Kwong-Man , Lau Yee-Man , Dhandhania Vidhu , Cai Zhu-Jun , Lee Yee-Ki , Lai Wing-Hon , Tse Hung-Fat , Siu Chung-Wah
Published: October 2018

Empagliflozin, a sodium-glucose co-transporter (SGLT) inhibitor, reduces heart failure and sudden cardiac death but the underlying mechanisms remain elusive. In cardiomyocytes, SGLT1 and SGLT2 expression is upregulated in diabetes mellitus, heart failure, and myocardial infarction. We hypothesise that empagliflozin exerts direct effects on cardiomyocytes that attenuate diabetic cardiomyopathy. To test this hypothesis, cardiomyocytes derived from human induced pluripotent stem cells (hiPSCs) were used to test the potential effects of empagliflozin on neutralization of cardiac dysfunction induced by diabetic-like cultures. Our results indicated that insulin-free high glucose culture significantly increased the size of and NPPB, SGLT1 and SGLT2 expression of hiPSC-derived cardiomyocytes. In addition, high glucose-treated hiPSC-derived cardiomyocytes exhibited reduced contractility regardless of the increased calcium transient capacity. Interestingly, application of empagliflozin before or after high glucose treatment effectively reduced the high glucose-induced cardiac abnormalities. Since application of empagliflozin did not significantly alter viability or glycolytic capacity of the hiPSC-derived cardiomyocytes, it is plausible that empagliflozin exerts its effects via the down-regulation of SGLT1, SGLT2 and GLUT1 expression. These observations provide supportive evidence that may help explain its unexpected benefit observed in the EMPA-REG trial.
Energy barriers at grain boundaries dominate charge carrier transport in an electron-conductive organic semiconductor
Authors: Vladimirov I. , Kühn M. , Geßner T. , May F. , Weitz R. T.
Published: October 2018

Semiconducting organic films that are at the heart of light-emitting diodes, solar cells and transistors frequently contain a large number of morphological defects, most prominently at the interconnects between crystalline regions. These grain boundaries can dominate the overall (opto-)electronic properties of the entire device and their exact morphological and energetic nature is still under current debate. Here, we explore in detail the energetics at the grain boundaries of a novel electron conductive perylene diimide thin film. Via a combination of temperature dependent charge transport measurements and ab-initio simulations at atomistic resolution, we identify that energetic barriers at grain boundaries dominate charge transport in our system. This novel aspect of physics at the grain boundary is distinct from previously identified grain-boundary defects that had been explained by trapping of charges. We furthermore derive molecular design criteria to suppress such energetic barriers at grain boundaries in future, more efficient organic semiconductors.
Modeling O2-dependent Heme Enzymes: A Quick Guide for Non-experts
Authors: Sancho Ferran , Santiago Gerard , Amengual-Rigo Pep , Guallar Victor
Published: October 2018

In this chapter, we provide an introduction and short review on how in silico techniques have been used to model O2-dependent heme enzymes. We aim at presenting a quick but wide assessment of different computational tools, including diverse bioinformatics and molecular modeling techniques. To perform such analysis, we focus on three different enzymes: the superfamily of Cytochrome P450 monooxygenases and the two related enzymes tryptophan 2,3-dioxygenase and indoleamine 2,3-dioxygenase. We hope that this overview will inspire the use of modeling tools, which, as shown here, have significantly contributed to the advance of mechanistic and design studies in these heme enzymes.
Structure and Function of Membrane-bound Bacterial Nitric Oxide Reductases
Authors: Tosha Takehiko , Shiro Yoshitsugu
Published: October 2018

Just as dioxygen is indispensable for lives, the analogous diatomic gas molecule nitric oxide (NO) also plays essential roles in several biological processes as a signaling molecule. However, NO induces cellular damage through reactions with biomolecules. To minimize the cytotoxic effect of NO in the signaling processes, nature utilizes a very sensitive NO receptor, heme-based soluble guanylate cyclase, to effectively capture NO produced by NO synthase. Nature has also developed NO decomposition systems to eliminate the cytotoxicity of NO. In particular, denitrifying bacteria have an effective NO decomposition system, since nitrite reductase continuously produces NO as a process of denitrification, a form of anaerobic respiration. In this chapter, we focus on the NO decomposition system in microbial denitrification, in which membrane-integrated nitric oxide reductase (NOR) catalyzes NO reduction at the heme/non-heme iron binuclear active center, to learn about heme and NO chemistry. On the basis of the crystal structures of NOR, a possible NO reduction mechanism is described. In addition, the structure of NOR is compared with that of evolutionary related oxygen-reducing cytochrome c oxidase to gain insight into the evolution of these respiratory enzymes.
Mechanisms of Nitric Oxide Sensing and Detoxification by Bacterial Hemoproteins
Authors: Moënne-Loccoz Pierre , Yukl Erik T. , Matsumura Hirotoshi
Published: October 2018

Nitric oxide (NO) plays important roles as a signaling molecule and antimicrobial agent throughout biology. As with O2, many of its physiological effects are mediated by its interactions with hemoproteins. This chapter focuses on bacterial hemoproteins that function as NO sensors and NO scavengers. These functions are particularly important to pathogenic organisms as they provide a means to resist the NO produced by the host immune response. We begin by presenting structural data for NO sensor proteins that highlight mechanisms of signal transduction upon binding of NO to the heme iron. We then describe two mechanisms of NO detoxification, the NO dioxygenase and NO reductase reactions. The former is catalyzed by members of the globin family and produces nitrate (NO3−), while the latter is catalyzed by heme/nonheme diiron NO reductases and produces nitrous oxide (N2O). A wealth of spectroscopic and rapid kinetics data on these proteins and synthetic or bioengineered analogues has begun to identify intermediates that provide insights into these physiologically important reactions.
A new 3-D coordination polymer as a precursor for CuI-based thermoelectric composites
Authors: Bai Shi-Qiang , Wong Ivy Hoi Ka , Zhang Nan , Lin Ke Karen , Lin Ming , Young David James , Hor T. S. Andy
Published: October 2018

A room temperature stable CuI-coordination polymer was characterized and pyrolysed to form a low density, thermoelectric composite with a relatively high Seebeck coefficient (∼1308 μV K−1) below 100 °C.
Effects of molecular weight fractionated humic acid on the transport and retention of quantum dots in porous media
Authors: Yang Jiangli , Xu Piao , Hu Liang , Zeng Guangming , Chen Anwei , He Kai , Huang Zhenzhen , Yi Huan , Qin Lei , Wan Jia
Published: October 2018

How molecular weight fractionated humic acid affects the transport and retention of quantum dots in porous media.
Environmental transformation of natural and engineered carbon nanoparticles and implications for the fate of organic contaminants
Authors: Sigmund Gabriel , Jiang Chuanjia , Hofmann Thilo , Chen Wei
Published: October 2018

Environmental transformations of natural and engineered carbon nanoparticles significantly affect their fate, transport, and interactions with organic contaminants.
Peracetylation as a strategy to improve oleuropein stability and its affinity to fatty foods
Authors: Bonacci Sonia , Paonessa Rosina , Costanzo Paola , Salerno Raffaele , Maiuolo Jessica , Nardi Monica , Procopio Antonio , Manuela Oliverio
Published: October 2018

Acetylated oleuropein, a safe, biologically active semi-synthetic stable derivative of oleuropein, is proposed as an easy alternative to make oleuropein more bioavailable and suitable to be added to fatty foods.
In situ grown nickel selenide on graphene nanohybrid electrodes for high energy density asymmetric supercapacitors
Authors: Kirubasankar Balakrishnan , Murugadoss Vignesh , Lin Jing , Ding Tao , Dong Mengyao , Liu Hu , Zhang Jiaoxia , Li Tingxi , Wang Ning , Guo Zhanhu , Angaiah Subramania
Published: October 2018

A NiSe–G∥AC asymmetric supercapacitor with both pseudocapacitance and EDLC mechanisms provides an energy density of 50.1 W h kg−1 and a power density of 816 W kg−1.
An integrated experimental and theoretical study on the optical properties of uniform hairy noble metal nanoparticles
Authors: Yang Di , Chen Yihuang , Peng Hongshang , Chen Gengxiang , Lin Zhiqun
Published: October 2018

An integrated experimental and modeling study reveals the contributions of intra- and inter-band transitions and the size and surface ligand effects on plasmonic absorption.
First enantioselective total synthesis of altersolanol A
Authors: Mechsner Bastian , Henßen Birgit , Pietruszka Jörg
Published: October 2018

The first enantioselective total synthesis of altersolanol A was accomplished by Diels–Alder cycloaddition promoted by (R)-3,3′-BINOL/boron Lewis acid.
Exquisite regulation of supramolecular equilibrium polymers in water: chain stoppers control length, polydispersity and viscoelasticity
Authors: Karunakaran Suneesh C. , Cafferty Brian J. , Peláez-Fernández Miguel , Neselu Kasahun , Schmidt-Krey Ingeborg , Fernandez-Nieves Alberto , Schuster Gary B. , Hud Nicholas V.
Published: October 2018

Positively charged molecules with planar surfaces control the length of supramolecular polymers formed by 2,4,6-triaminopyrimidine and a modified cyanuric acid.
Transcriptional analysis of long non-coding RNAs in facet joint osteoarthritis
Authors: Chen Chu , Xu Guanhua , Yuan Kun , Sun Yuyu , Bao Guofeng , Xu Dawei , Cui Zhiming
Published: October 2018

It is recognized that facet joint osteoarthritis (FJOA) is commonly induced by the degeneration of articular cartilage of the facet joint.
Fabrication of covalently linked exfoliated boron nitride nanosheet/multi-walled carbon nanotube hybrid particles for thermal conductive composite materials
Authors: Kim Kiho , Oh Hyunwoo , Kim Jooheon
Published: October 2018

Boron nitride nanosheet (BNNS)/multi-walled carbon nanotube (MWCNT) hybrid particles were synthesized for use as a conductive filler for epoxy and polyphenylene sulfide (PPS).
Mechanism of adsorption of humic acid by modified aged refuse
Authors: Zhang Aiping , Chen Weiming , Gu Zhepei , Li Qibin , Shi Guozhong
Published: October 2018

In the present study, aged refuse (AR) was modified to be applied as an adsorbent to remove humic acid from water.
Schwertmannite: occurrence, properties, synthesis and application in environmental remediation
Authors: Zhang Zhuo , Bi Xue , Li Xintong , Zhao Qiancheng , Chen Honghan
Published: October 2018

Schwertmannite is a typical iron-derived mineral, which was originally discovered in acid mine drainings and subsequently synthesized in the laboratory.
Effects of hydrotalcite on rigid polyurethane foam composites containing a fire retarding agent: compressive stress, combustion resistance, sound absorption, and electromagnetic shielding effectiveness
Authors: Peng Hao-Kai , Wang Xiao Xiao , Li Ting-Ting , Huang Shih-Yu , Lin Qi , Shiu Bing-Chiuan , Lou Ching-Wen , Lin Jia-Horng
Published: October 2018

The synthesis of rigid polyurethane foam.
Transition metal-promoted hierarchical ETS-10 solid base for glycerol transesterification
Authors: Xiang Mei , Wu Dongfang
Published: October 2018

The inherent Lewis basicity and hierarchical structure of ETS-10 favor oriented conversion of glycerol. Moreover, Ni0 species play a critical role in accelerating the interaction of Lewis basic sites with active glycerol hydroxyl groups.
The evolved fast rotator Sargas
Authors: Domiciano de Souza A. , Bouchaud K. , Rieutord M. , Espinosa Lara F. , Putigny B.
Published: October 2018

Context. Gravity darkening (GD) and flattening are important consequences of stellar rotation. The precise characterization of these effects across the Hertzsprung–Russell (H-R) diagram is crucial to a deeper understanding of stellar structure and evolution.

Aims. We seek to characterize such important effects on Sargas (θ Scorpii), an evolved, fast-rotating, intermediate-mass (∼5 M⊙) star, located in a region of the H-R diagram where they have never been directly measured as far as we know.

Methods. We use our numerical model CHARRON to analyze interferometric (VLTI/PIONIER) and spectroscopic (VLT/UVES) observations through a MCMC model-fitting procedure. The visibilities and closure phases from the PIONIER data are particularly sensitive to rotational flattening and GD. Adopting the Roche approximation, we investigate two GD models: (1) the β-model (Teff ∝
geff β), which includes the classical von Zeipel’s GD law, and (2) the ω-model, where the flux is assumed to be anti-parallel to geff.

Results. Using this approach we measure several physical parameters of Sargas, namely, equatorial radius, mass, equatorial rotation velocity, mean Teff, inclination and position angle of the rotation axis, and β. In particular, we show that the measured β leads to a surface flux distribution equivalent to the one given by the ω-model. Thanks to our results, we also show that Sargas is most probably located in a rare and interesting region of the H-R diagram: within the Hertzsprung gap and over the hot edge of the instability strip (equatorial regions inside it and polar regions outside it because of GD).

Conclusions. These results show once more the power of optical/infrared long-baseline interferometry, combined with high-resolution spectroscopy, to directly measure fast-rotation effects and stellar parameters, in particular GD. As was the case for a few fast rotators previously studied by interferometry, the ω-model provides a physically more profound description of Sargas’ GD, without the need of a β exponent. It will also be interesting to further investigate the implications of the singular location of such a fast rotator as Sargas in the H-R diagram.
Capturing the oxidation of silicon carbide in rocky exoplanetary interiors
Authors: Hakim Kaustubh , van Westrenen Wim , Dominik Carsten
Published: October 2018

Context. Theoretical models predict the condensation of silicon carbide around host stars with C/O ratios higher than 0.65 (cf. C/OSun = 0.54), in addition to its observations in meteorites, interstellar medium and protoplanetary disks. Consequently, the interiors of rocky exoplanets born from carbon-enriched refractory material are often assumed to contain large amounts of silicon carbide.

Aims. Here we aim to investigate the stability of silicon carbide in the interior of carbon-enriched rocky exoplanets and to derive the reaction leading to its transformation.

Methods. We performed a high-pressure high-temperature experiment to investigate the reaction between a silicon carbide layer and a layer representative of the bulk composition of a carbon-enriched rocky exoplanet.

Results. We report the reaction leading to oxidation of silicon carbide producing quartz, graphite, and molten iron silicide. Combined with previous studies, we show that in order to stabilize silicon carbide, carbon saturation is not sufficient, and a complete reduction of Fe2+ to Fe0 in a planetary mantle is required, suggesting that future spectroscopic detection of Fe2+ or Fe3+ on the surface of rocky exoplanets would imply the absence of silicon carbide in their interiors.
High-resolution abundance analysis of four red giants in the globular cluster NGC 6558
Authors: Barbuy B. , Muniz L. , Ortolani S. , Ernandes H. , Dias B. , Saviane I. , Kerber L. , Bica E. , Pérez-Villegas A. , Rossi L. , Held E. V.
Published: October 2018

Context. NGC 6558 is a bulge globular cluster with a blue horizontal branch (BHB), combined with a metallicity of [Fe/H] ≈ −1.0. It is similar to HP 1 and NGC 6522, which could be among the oldest objects in the Galaxy. Element abundances in these clusters could reveal the nature of the first supernovae.

Aims. We aim to carry out detailed spectroscopic analysis for four red giants of NGC 6558, in order to derive the abundances of the light elements C, N, O, Na, Al, the α-elements Mg, Si, Ca, Ti, and the heavy elements Y, Ba, and Eu.

Methods. High-resolution spectra of four stars with FLAMES-UVES at VLT UT2-Kueyen were analysed. Spectroscopic parameter-derivation was based on excitation and ionization equilibrium of Fe I and Fe II.

Results. This analysis results in a metallicity of [Fe/H] = − 1.17 ± 0.10 for NGC 6558. We find the expected α-element enhancements in O and Mg with [O/Fe] = +0.40, [Mg/Fe] = +0.33, and low enhancements in Si and Ca. Ti has a moderate enhancement of [Ti/Fe] = +0.22. The r-element Eu appears very enhanced with a mean value of [Eu/Fe] = +0.63. The first peak s-elements Y and Sr are also enhanced, these results have however to be treated with caution, given the uncertainties in the continuum definition; the use of neutral species (Sr I, Y I), instead of the dominant ionized species is another source of uncertainty. Ba appears to have a solar abundance ratio relative to Fe.

Conclusions. NGC 6558 shows an abundance pattern that could be typical of the oldest inner bulge globular clusters, together with the pattern in the similar clusters NGC 6522 and HP 1. They show low abundances of the odd-Z elements Na and Al, and of the explosive nucleosynthesis α-elements Si, Ca, and Ti. The hydrostatic burning α-elements O and Mg are normally enhanced as expected in old stars enriched with yields from core-collapse supernovae, and the iron-peak elements Mn, Cu, Zn show low abundances, which is expected for Mn and Cu, but not for Zn. Finally, the cluster trio NGC 6558, NGC 6522, and HP 1 have relatively high abundances of first-peak heavy elements, variable second-peak element Ba, and the r-element Eu is enhanced. The latter is particularly high in NGC 6558.