bluuebunny/crossref_metadata_2025 huggingface dataset:
Increased glia density in the caudate nucleus in williams syndrome: Implications for frontostriatal dysfunction in autism
Authors: Hanson Kari L. , Lew Caroline H. , Hrvoj‐Mihic Branka , Groeniger Kimberly M. , Halgren Eric , Bellugi Ursula , Semendeferi Katerina
Published: November 2017

Williams syndrome (WS) is a rare neurodevelopmental disorder with a well‐described, known genetic etiology. In contrast to Autism Spectrum Disorders (ASD), WS has a unique phenotype characterized by global reductions in IQ and visuospatial ability, with relatively preserved language function, enhanced reactivity to social stimuli and music, and an unusual eagerness to interact socially with strangers. A duplication of the deleted region in WS has been implicated in a subset of ASD cases, defining a spectrum of genetic and behavioral variation at this locus defined by these opposite extremes in social behavior. The hypersociability characteristic of WS may be linked to abnormalities of frontostriatal circuitry that manifest as deficits in inhibitory control of behavior. Here, we examined the density of neurons and glia in associative and limbic territories of the striatum including the caudate, putamen, and nucleus accumbens regions in Nissl stained sections in five pairs of age, sex, and hemisphere‐matched WS and typically‐developing control (TD) subjects. In contrast to what is reported in ASD, no significant increase in overall neuron density was observed in this study. However, we found a significant increase in the density of glia in the dorsal caudate nucleus, and in the ratio of glia to neurons in the dorsal and medial caudate nucleus in WS, accompanied by a significant increase in density of oligodendrocytes in the medial caudate nucleus. These cellular abnormalities may underlie reduced frontostriatal activity observed in WS, with implications for understanding altered connectivity and function in ASD. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 78: 531–545, 2018
A Novel Diterpenoid Suppresses Osteoclastogenesis and Promotes Osteogenesis by Inhibiting Ifrd1-Mediated and IκBα-Mediated p65 Nuclear Translocation
Authors: Xie Zi'ang , Yu Hejun , Sun Xuewu , Tang Pan , Jie Zhiwei , Chen Shuai , Wang Jiying , Qin An , Fan Shunwu
Published: November 2017

Osteoporosis develops because of impaired bone formation and/or excessive bone resorption. Although the pharmacological treatment of osteoporosis has been extensively developed, alternative treatments are still needed. Here, we showed that oridonin (ORI), a diterpenoid isolated from Rabdosia rubescens, can suppress osteoclastogenesis and enhance osteogenesis. ORI inhibited the receptor activator of nuclear factor-κB (NF-κB) ligand (RANKL)-induced osteoclast formation and bone resorption through the inhibition of p65 nuclear translocation. ORI-induced inhibition of this translocation led to an increase in osteoblast differentiation and mineralization through the promotion of Smad1/Smad5 phosphorylation. Further analyses demonstrated that the inhibition of p65 nuclear translocation is due to the suppression of IκBα phosphorylation and the induced proteasomal degradation of interferon-related development regulator 1 (Ifrd1), a transcriptional corepressor that is involved in the suppression of NF-κB nuclear translocation. Moreover, mice treated with ORI at catabolic and anabolic windows showed a considerable attenuation of ovariectomy (OVX)-induced osteoporosis. Taken together, our findings reveal that ORI protects against OVX-induced bone loss via inhibiting osteoclastic bone resorption but enhancing osteoblastic bone formation through abolishing both Ifrd1-mediating and IκBα-mediated p65 nuclear translocation. These results show the potential of ORI for treatment of osteoporosis and highlight Ifrd1 as a another novel promising target for anti-osteoporotic drugs. © 2017 American Society for Bone and Mineral Research
Suppression of hyaluronan synthesis attenuates the tumorigenicity of low‐grade chondrosarcoma
Authors: Hamada Shunsuke , Nishida Yoshihiro , Zhuo Lisheng , Shinomura Tamayuki , Ikuta Kunihiro , Arai Eisuke , Koike Hiroshi , Kimata Koji , Ushida Takahiro , Ishiguro Naoki
Published: November 2017

Hyaluronan (HA) has been shown to play crucial roles in the tumorigenicity of malignant tumors. Chondrosarcoma, particularly when low‐grade, is characterized by the formation of an extracellular matrix (ECM) containing abundant HA, and its drug/radiation resistance has become a clinically relevant problem. This study aimed to evaluate the effects of an HA synthesis inhibitor, 4‐methylumbelliferone (MU), on ECM formation as well as antitumor effects in chondrosarcoma. We investigated the effects of MU on rat chondrosarcoma (RCS) cells with a grade I histological malignancy in vitro and in vivo grafted model. HA binding protein (HABP) stainability on and around the RCS cells was effectively reduced with treatment of MU. ECM formation was markedly suppressed by MU at a dose of 1.0 mM. Cell proliferation was significantly reduced by MU at 24 h. Cell motility and invasion were suppressed in a dose‐dependent manner by MU. No significant changes in mRNA expression of Has1−3 were observed. Furthermore, MU inhibited the growth of grafted tumors in vivo. Histologically, chondrosarcoma cells of control tumors showed a cell‐clustering structure. HABP stainability was markedly decreased in the MU‐treated group. These results suggest that MU exhibits antitumor effects on low‐grade chondrosarcoma, via inhibition of HA accumulation and ECM formation. MU, which is an approved drug in bile therapy, could be a new off‐label medication for chondrosarcomas. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 36:1573–1580, 2018.
Fisher information and Cramér‐Rao lower bound for experimental design in parallel imaging
Authors: Bouhrara Mustapha , Spencer Richard G.
Published: November 2017

Purpose

The Cramér‐Rao lower bound (CRLB) is widely used in the design of magnetic resonance (MR) experiments for parameter estimation. Previous work has considered only Gaussian or Rician noise distributions in this calculation. However, the noise distribution for multi‐coil acquisitions, such as in parallel imaging, obeys the noncentral χ‐distribution under many circumstances. The purpose of this paper is to present the CRLB calculation for parameter estimation from multi‐coil acquisitions.

Theory and Methods

We perform explicit calculations of Fisher matrix elements and the associated CRLB for noise distributions following the noncentral χ‐distribution. The special case of diffusion kurtosis is examined as an important example. For comparison with analytic results, Monte Carlo (MC) simulations were conducted to evaluate experimental minimum standard deviations (SDs) in the estimation of diffusion kurtosis model parameters. Results were obtained for a range of signal‐to‐noise ratios (SNRs), and for both the conventional case of Gaussian noise distribution and noncentral χ‐distribution with different numbers of coils, m.

Results

At low‐to‐moderate SNR, the noncentral χ‐distribution deviates substantially from the Gaussian distribution. Our results indicate that this departure is more pronounced for larger values of m. As expected, the minimum SDs (i.e., CRLB) in derived diffusion kurtosis model parameters assuming a noncentral χ‐distribution provided a closer match to the MC simulations as compared to the Gaussian results.

Conclusion

Estimates of minimum variance for parameter estimation and experimental design provided by the CRLB must account for the noncentral χ‐distribution of noise in multi‐coil acquisitions, especially in the low‐to‐moderate SNR regime. Magn Reson Med 79:3249–3255, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Wissenschaftliche Stammbäume der theoretischen Chemie
Authors: Jug Karl , Andrae Dirk
Published: November 2017

Das Genealogieprojekt Theoretische Chemie bietet in einer Onlinedatenbank umfangreiche Informationen über Theoretiker und deren wissenschaftliche Vor‐ und Nachfahren aus mehreren Jahrhunderten. Mittlerweile sind über 3000 Einträge recherchierbar.
einhundertundfünfzig
Authors: Bulmahn Maren
Published: November 2017

Verblüffendes, Informatives, schon fast Vergessenes: Die Serie Zahlenstatistik des Monats liefert Fakten aus 150 Jahren. In diesem Monat geht es um Chemie, die kracht und stinkt.
Neue Wege in der Bibliometrie
Authors: Böhme Uwe , Tesch Silke
Published: November 2017

Klassische Zitationsmetriken wie der Journal‐Impactfaktor erfassen nicht, wie sich Publikationen, Forschungsdaten, Software und andere wissenschaftliche Objekte im Internet und öffentlichen Medien verbreiten und wie sie wirken. Genau das tut aber die alternative Impactmetrik, kurz Altmetrik.
MANS‐15 an der Universität Leipzig
Authors: Kohlmann Holger , Kersting Berthold
Published: November 2017

Ende August trafen sich etwa 150 Chemiker aus Deutschland zum fünfzehnten mitteldeutschen Anorganiker‐Nachwuchssymposium (MANS), diesmal in Leipzig. Die Veranstaltung findet seit dem Jahr 2003 im jährlichen Wechsel in Chemnitz, Halle, Leipzig, Jena, Dresden und Freiberg statt. Außerdem nahmen auch Chemiker aus Bayreuth, Cottbus‐Senftenberg und Magdeburg an der eintägigen Konferenz teil.
Materialwissenschaft: geschwungen, leicht und prämiert
Authors: Bulmahn Maren
Published: November 2017

Der überwiegende Teil der Faserverbundkunststoffe ist glasfaserverstärkt. Die Produktion solcher Composites nimmt seit fünf Jahren zu. Für diese und andere Verbünde gab es Innovationspreise.
Increase in the skewness of extratropical vertical velocities with climate warming: fully nonlinear simulations versus moist baroclinic instability
Authors: O'Gorman Paul A. , Merlis Timothy M. , Singh Martin S.
Published: November 2017

The distribution of vertical velocities in the extratropical troposphere is skewed such that upward motions are faster than downward motions. This skewness is important for the intensity distribution of precipitation and for the effective static stability experienced by moist eddies. We show here that the skewness of the vertical velocity increases in magnitude as the climate warms in simulations with an idealized general circulation model (GCM), except in very warm climates. That the skewness increases with warming is consistent with studies of moist baroclinic instability which suggest that the area of updraughts should contract as the stratification approaches moist neutrality in warm climates. However, the increase in skewness with warming is much weaker in the fully nonlinear simulations as compared to what is found for unstable modes of moist baroclinic instability in the same GCM. Nonlinear equilibration to a macroturbulent state leads to a reduction in skewness in warm climates. Therefore, while the unstable modes may be relevant for some cases of cyclogenesis, they overestimate the effect of warming on the skewness of the overall distribution of the vertical velocity. Remarkably, the most unstable mode transitions from a quasi‐periodic wave to an isolated diabatic Rossby vortex at sufficiently high temperatures, with possible implications for fast‐growing disturbances in warm climates.
Exploring Site Formation and Building Local Contexts through Wiggle-Match Radiocarbon Dating: Re-Dating of the Firth of Clyde Crannogs, Scotland
Authors: Jacobsson Piotr , Hale Alex G.C. , Cook Gordon , Hamilton Derek
Published: November 2017

There are at least four wooden intertidal platforms, also known as marine crannogs, in the Firth of Clyde, on the west coast of Scotland. The interpretation of these sites partly depends on their dating and, if coeval, they could point to the presence of a native maritime hub. Furthermore, the spatial coincidence with the terminus of the Antonine Wall has led to speculation about the role they may have played in Roman-native interaction during the occupation of southern Scotland in the early first millennium calad. Hence, a better absolute chronology is essential to evaluate whether the marine crannogs were contemporary with one another and whether they related to any known historic events. This article presents results of a wiggle-match dating project aimed at resolving these uncertainties at two of the sites in question, Dumbuck and Erskine Bridge crannogs. The results show that the construction of these sites pre-date direct Roman influence in Scotland. Furthermore, the results indicate that the two sites were built at least 300 years apart, forcing us to consider the possibility that they may have functioned in very different historical contexts. Other findings include technical observations on the fine shape of the radiocarbon calibration curve near the turn of the first millenniabc/adand potential evidence for persistent contamination in decayed and exposed sections of waterlogged alder.
PRISMATIC BLADE PRODUCTION IN THE LOWER CACAULAPA VALLEY, HONDURAS: IMPLICATIONS FOR A LATE CLASSIC POLITICAL ECONOMY
Authors: McFarlane William J. , Schortman Edward M.
Published: November 2017

Investigations of ancient political economies frequently focus on craft production. How manufacturing is organized can provide critical insights on more than the economy because social interactions and political processes are also involved. Here we consider how the acquisition, fabrication, and distribution of obsidian blades figured in the political strategies of craftworkers and elites within the Late Classic (AD 600–800) lower Cacaulapa Valley, northwestern Honduras. This evidence provides insights into the organization of craft manufacture across southeastern Mesoamerica and suggests that current models do not capture the varied production strategies that may be pursued within the same polity.
MIGRATION FROM WITHIN AND WITHOUT: IN THE FOOTSTEPS OF EASTERN CHRISTIANS IN THE EARLY MODERN WORLD
Authors: Ghobrial John-Paul A.
Published: November 2017

From Lebanese politicians in Argentina to Iraqi immigrants in Sweden, Middle Eastern Christians can be found today scattered across the entire world. Too often, however, this global migration has been seen purely as a modern development, one arising from contemporary political and religious tensions in the Middle East. In fact, this type of mobility had earlier manifestations in the early modern period. From the sixteenth century onwards, Christians from the Ottoman Empire set out for distant worlds and foreign lands, travelling as far as Europe, India, Russia and even the Americas and leaving traces of themselves in countless European and Middle Eastern archives, chanceries and libraries. This paper lays out a framework for understanding movement in the early modern world in a way that pays as much attention to how migrants understood their own travels as to contemporary European ideas about Eastern Christian mobility. Focusing on the intersection of two traditions of sources, I explore here how European and Eastern Christian perspectives about migration drew from one another, reinforcing and feeding on each other in powerful, mutually constitutive ways. In doing so, this paper seeks to make a contribution to our understanding of the everyday experience of circulation and mobility in the early modern world.
LANGUAGES OF FREEDOM IN DECOLONISING AFRICAThe Gladstone Prize Winner
Authors: Hunter Emma
Published: November 2017

The ‘triumph of liberalism’ in the mid-twentieth-century west is well known and much studied. But what has it meant for the way the decolonisation of Africa has been viewed, both at the time and since? In this paper, I suggest that it has quietly but effectively shaped our understanding of African political thinking in the 1950s to 1960s. Although the nationalist framing that once led historians to neglect those aspects of the political thinking of the period which did not move in the direction of a territorial nation-state has now been challenged, we still struggle with those aspects of political thinking that were, for instance, suspicious of a focus on the individual and profoundly opposed to egalitarian visions of a post-colonial future. I argue that to understand better the history of decolonisation in the African continent, both before and after independence, while also enabling comparative work with other times and places, we need to think more carefully and sensitively about how freedom and equality were understood and argued over in local contexts.
Relations entre dépression et troubles cognitifs
Authors: Clerc Marie-Therese , von Gunten Armin
Published: November 2017

Zusammenfassung. Depressionen, leichte kognitive Störungen und Demenzen sind besonders bei älteren Menschen häufig assoziiert. Ähnliche neuropathologische Mechanismen scheinen diesen Zusammenhang und die gegenseitigen Einflüsse mindestens teilweise zu erklären. Wir schlagen hier eine Kurzreview der Rolle der Depression als Risikofaktor, Prodrom oder Folge der kognitiven Störungen vor und skizzieren kurz mögliche Behandlungsansätze.
CME
Authors: Zweig Annina , Pohl Daniel
Published: November 2017

Zusammenfassung. Funktionelle Magen-Darm-Beschwerden sind in der Allgemeinbevölkerung weit verbreitet, und das Reizdarmsyndrom (Irritable Bowel Syndrome, IBS) ist eines der häufigsten gastroenterologischen Krankheitsbilder. Trotz individuell sehr unterschiedlicher klinischer Präsentation berichtet ein Grossteil der Patienten über eine Abhängigkeit ihrer Beschwerden von der Nahrungsaufnahme bzw. von bestimmten Nahrungsmitteln. Die FODMAP-arme Diät, durch eine spezialisierte Ernährungsberatung instruiert, zeigt sich sehr wirksam zur Symptomreduktion bei IBS-Patienten. Sie basiert auf einer Reduktion fermentierbarer Kohlenhydrate. Ziel der Diät ist es, potenzielle nutritive Auslöser abdominaler Symptome zu identifizieren und diese in der täglichen Ernährung zu meiden.
Statistical parity-time-symmetric lasing in an optical fibre network
Authors: Jahromi Ali K. , Hassan Absar U. , Christodoulides Demetrios N. , Abouraddy Ayman F.
Published: November 2017

Parity-time (PT)-symmetry in optics is a condition whereby the real and imaginary parts of the refractive index across a photonic structure are deliberately balanced. This balance can lead to interesting optical phenomena, such as unidirectional invisibility, loss-induced lasing, single-mode lasing from multimode resonators, and non-reciprocal effects in conjunction with nonlinearities. Because PT-symmetry has been thought of as fragile, experimental realisations to date have been usually restricted to on-chip micro-devices. Here, we demonstrate that certain features of PT-symmetry are sufficiently robust to survive the statistical fluctuations associated with a macroscopic optical cavity. We examine the lasing dynamics in optical fibre-based coupled cavities more than a kilometre in length with balanced gain and loss. Although fluctuations can detune the cavity by more than the free spectral range, the behaviour of the lasing threshold and the laser power is that expected from a PT-stable system. Furthermore, we observe a statistical symmetry breaking upon varying the cavity loss.
Self-patterning of rostral-caudal neuroectoderm requires dual role of Fgf signaling for localized Wnt antagonism
Authors: Takata Nozomu , Sakakura Eriko , Eiraku Mototsugu , Kasukawa Takeya , Sasai Yoshiki
Published: November 2017

The neuroectoderm is patterned along a rostral-caudal axis in response to localized factors in the embryo, but exactly how these factors act as positional information for this patterning is not yet fully understood. Here, using the self-organizing properties of mouse embryonic stem cell (ESC), we report that ESC-derived neuroectoderm self-generates a Six3+ rostral and a Irx3+ caudal bipolarized patterning. In this instance, localized Fgf signaling performs dual roles, as it regulates Six3+ rostral polarization at an earlier stage and promotes Wnt signaling at a later stage. The Wnt signaling components are differentially expressed in the polarized tissues, leading to genome-wide Irx3+ caudal-polarization signals. Surprisingly, differentially expressed Wnt agonists and antagonists have essential roles in orchestrating the formation of a balanced rostral-caudal neuroectoderm pattern. Together, our findings provide key processes for dynamic self-patterning and evidence that a temporally and locally regulated interaction between Fgf and Wnt signaling controls self-patterning in ESC-derived neuroectoderm.
A mesoporous cationic thorium-organic framework that rapidly traps anionic persistent organic pollutants
Authors: Li Yuxiang , Yang Zaixing , Wang Yanlong , Bai Zhuanling , Zheng Tao , Dai Xing , Liu Shengtang , Gui Daxiang , Liu Wei , Chen Meng , Chen Lanhua , Diwu Juan , Zhu Lingyan , Zhou Ruhong , Chai Zhifang , Albrecht-Schmitt Thomas E. , Wang Shuao
Published: November 2017

Many environmental pollutants inherently exist in their anionic forms and are therefore highly mobile in natural water systems. Cationic framework materials that can capture those pollutants are highly desirable but scarcely reported. Here we present a mesoporous cationic thorium-based MOF (SCU-8) containing channels with a large inner diameter of 2.2 nm and possessing a high surface area of 1360 m2 g−1. The anion-exchange properties of SCU-8 were explored with many anions including small oxo anions like ReO4− and Cr2O72− as well as anionic organic dyes like methyl blue and the persistent organic pollutant, perfluorooctane sulfonate (PFOS). Both fast uptake kinetics and great sorption selectivity toward PFOS are observed. The underlying sorption mechanism was probed using quantum mechanical and molecular dynamics simulations. These computational results reveal that PFOS anions are immobilized in SCU-8 by driving forces including electrostatic interactions, hydrogen bonds, hydrophobic interactions, and van der Waals interactions at different adsorption stages.
Aperiodic nanoplasmonic devices for directional colour filtering and sensing
Authors: Davis Matthew S. , Zhu Wenqi , Xu Ting , Lee Jay K. , Lezec Henri J. , Agrawal Amit
Published: November 2017

Exploiting the wave-nature of light in its simplest form, periodic architectures have enabled a panoply of tunable optical devices with the ability to perform useful functions such as filtering, spectroscopy, and multiplexing. Here, we remove the constraint of structural periodicity to enhance, simultaneously, the performance and functionality of passive plasmonic devices operating at optical frequencies. By using a physically intuitive, first-order interference model of plasmon-light interactions, we demonstrate a simple and efficient route towards designing devices with flexible, multi-spectral optical response, fundamentally not achievable using periodic architectures. Leveraging this approach, we experimentally implement ultra-compact directional light-filters and colour-sorters exhibiting angle- or spectrally-tunable optical responses with high contrast, and low spectral or spatial crosstalk. Expanding the potential of aperiodic systems to implement tailored spectral and angular responses, these results hint at promising applications in solar-energy harvesting, optical signal multiplexing, and integrated sensing.
Thermodynamic signatures of the field-induced states of graphite
Authors: LeBoeuf D. , Rischau C. W. , Seyfarth G. , Küchler R. , Berben M. , Wiedmann S. , Tabis W. , Frachet M. , Behnia K. , Fauqué B.
Published: November 2017

When a magnetic field confines the carriers of a Fermi sea to their lowest Landau level, electron−electron interactions are expected to play a significant role in determining the electronic ground state. Graphite is known to host a sequence of magnetic field-induced states driven by such interactions. Three decades after their discovery, thermodynamic signatures of these instabilities are still elusive. Here we report the detection of these transitions with sound velocity measurements. The evolution of elastic constant anomalies with temperature and magnetic field allows to draw a detailed phase diagram which shows that the ground state evolves in a sequence of thermodynamic phase transitions. Our analysis indicates that the electron−electron interaction is not the sole driving force of these transitions and that lattice degrees of freedom play an important role.
Quantum wave mixing and visualisation of coherent and superposed photonic states in a waveguide
Authors: Dmitriev A. Yu. , Shaikhaidarov R. , Antonov V. N. , Hönigl-Decrinis T. , Astafiev O. V.
Published: November 2017

Superconducting quantum systems (artificial atoms) have been recently successfully used to demonstrate on-chip effects of quantum optics with single atoms in the microwave range. In particular, a well-known effect of four wave mixing could reveal a series of features beyond classical physics, when a non-linear medium is scaled down to a single quantum scatterer. Here we demonstrate the phenomenon of quantum wave mixing (QWM) on a single superconducting artificial atom. In the QWM, the spectrum of elastically scattered radiation is a direct map of the interacting superposed and coherent photonic states. Moreover, the artificial atom visualises photon-state statistics, distinguishing coherent, one- and two-photon superposed states with the finite (quantised) number of peaks in the quantum regime. Our results may give a new insight into nonlinear quantum effects in microwave optics with artificial atoms.
Underwater sound from vessel traffic reduces the effective communication range in Atlantic cod and haddock
Authors: Stanley Jenni A. , Van Parijs Sofie M. , Hatch Leila T.
Published: November 2017

Stellwagen Bank National Marine Sanctuary is located in Massachusetts Bay off the densely populated northeast coast of the United States; subsequently, the marine inhabitants of the area are exposed to elevated levels of anthropogenic underwater sound, particularly due to commercial shipping. The current study investigated the alteration of estimated effective communication spaces at three spawning locations for populations of the commercially and ecologically important fishes, Atlantic cod (Gadus morhua) and haddock (Melanogrammus aeglefinus). Both the ambient sound pressure levels and the estimated effective vocalization radii, estimated through spherical spreading models, fluctuated dramatically during the three-month recording periods. Increases in sound pressure level appeared to be largely driven by large vessel activity, and accordingly exhibited a significant positive correlation with the number of Automatic Identification System tracked vessels at the two of the three sites. The near constant high levels of low frequency sound and consequential reduction in the communication space observed at these recording sites during times of high vocalization activity raises significant concerns that communication between conspecifics may be compromised during critical biological periods. This study takes the first steps in evaluating these animals’ communication spaces and alteration of these spaces due to anthropogenic underwater sound.
Microscopic Differentiation of Plasmonic Nanoparticles for the Ratiometric Read-out of Target DNA
Authors: Wu Zhenjie , Yang Rui , Zu Di , Sun Shuqing
Published: November 2017

The development of highly sensitive and rapid methods for detecting DNA is of critical importance. Here, we describe a strategy for the digital detection of target DNA at the femto-molar level. Individual DNA molecules were encoded with a single gold nanorod (AuNR), separated and enriched by magnetic immune-separation. The coding gold nanorods were then de-hybridized and dispersed into a gold nanosphere (AuNS) solution at a certain concentration, and both gold nanoparticles were immobilized on glass slides for dark-field microscopic imaging. Using an in-house Matlab program, the concentration of the target DNA was calculated based on the ratio of the coding gold nanorods to gold nanospheres. By combining the coding of individual biomolecules with a single gold nanorod and the use of gold nanospheres as an internal standard, a method for the rapid and accurate digital detection of target DNA to the femto-molar level was developed.
A study on the correlation between the dewetting temperature of Ag film and SERS intensity
Authors: Quan Jiamin , Zhang Jie , Qi Xueqiang , Li Junying , Wang Ning , Zhu Yong
Published: November 2017

The thermally dewetted metal nano-islands have been actively investigated as cost-effective SERS-active substrates with a large area, good reproducibility and repeatability via simple fabrication process. However, the correlation between the dewetting temperature of metal film and SERS intensity hasn’t been systematically studied. In this work, taking Ag nano-islands (AgNIs) as an example, we reported a strategy to investigate the correlation between the dewetting temperature of metal film and SERS intensity. We described the morphology evolution of AgNIs on the SiO2 planar substrate in different temperatures and got the quantitative information in surface-limited diffusion process (SLDP) as a function of annealing temperature via classical mean-field nucleation theory. Those functions were further used in the simulation of electromagnetic field to obtain the correlation between the dewetting temperature of Ag film and theoretical analysis. In addition, Raman mapping was done on samples annealed at different temperatures, with R6G as an analyte, to accomplish the analysis of the correlation between the dewetting temperature of Ag film and SERS intensity, which is consistent with the theoretical analysis. For SLDP, we used the morphological characterization of five samples prepared by different annealing temperatures to successfully illustrate the change in SERS intensity with the temperature fluctuation, obtaining a small deviation between the experimental results and theoretic prediction.
Reversing the undesirable pH-profile of doxorubicin via activation of a di-substituted maleamic acid prodrug at tumor acidity
Authors: Zhang Anqi , Yao Lan , An Ming
Published: November 2017

Selective drug release at pH 6.7 over pH 7.4 is achieved through a combination of ‘switch-on’ and ‘switch-off’ mechanisms.
Engineered photoproteins that give rise to photosynthetically-incompetent bacteria are effective as photovoltaic materials for biohybrid photoelectrochemical cells
Authors: Liu Juntai , Friebe Vincent M. , Swainsbury David J. K. , Crouch Lucy I. , Szabo David A. , Frese Raoul N. , Jones Michael R.
Published: November 2017

We address concerns that PufX-deficient RCLH1 complexes from photosynthetically-incompetent bacteria may not be suitable as photovoltaic materials for incorporation into biohybrid photoelectrochemical cells.
Hot off the press
Authors: Hill Robert A. , Sutherland Andrew
Published: November 2017

A personal selection of 32 recent papers is presented covering various aspects of current developments in bioorganic chemistry and novel natural products such as tryptorubin A isolated from a Streptomyces species.
Spirals and helices by asymmetric active surface growth
Authors: He Jiating , Wang Yong , Fan Zhanxi , Wang Yawen , Zhang Hua , Chen Hongyu
Published: November 2017

Spiral and helical Au nanowires can be directly grown via the Active Surface Growth mechanism, which is controlled by the ratio of reactant concentration.
Strong polarization switching with low-energy loss in hydrogen-bonded organic antiferroelectrics
Authors: Horiuchi S. , Kumai R. , Ishibashi S.
Published: November 2017

Highly efficient switching of strong polarization in squaric acid crystal arises from 90° rotation of sheet polarization in a pseudo-tetragonal lattice.
A comprehensive optimization study on Bi2Te3-based thermoelectric generators using the Taguchi method
Authors: Kishore Ravi Anant , Kumar Prashant , Priya Shashank
Published: November 2017

This study provides design of high performance thermoelectric generator using numerical technique in conjunction with Taguchi robust optimization method.
GPR4 knockout improves renal ischemia–reperfusion injury and inhibits apoptosis via suppressing the expression of CHOP
Authors: Dong Biao , Zhang Xiaolu , Fan Yafeng , Cao Songqiang , Zhang Xuepei
Published: November 2017

The aim of the present study was to investigate the effects and molecular mechanisms of GPR4 (G-protein-coupled receptor 4) in cell apoptosis and renal ischemia–reperfusion (IR) injury in vivo and in vitro. GPR4−/− mice and wild-type (WT) mice underwent renal IR or sham procedures. For hypoxia/reoxygenation (HR), human umbilical vein endothelial cells (HUVECs) were subjected to 4 h of hypoxia, followed by 6 h of reoxygenation. Renal histological changes were observed by periodic acid-Schiff staining and myeloperoxidase activity. Apoptosis was detected by TUNEL staining. GPR4, C/EBP-homologous protein (CHOP) and cleaved caspase-3 protein expressions were detected by western blot. Both GPR4 and CHOP were up-regulated after renal IR in mice. GPR4-knockout mice had significantly less renal damage and decreased TUNEL-positive cells than WT controls after IR. Bone marrow chimeras demonstrated that it was due to the GPR4 inactivation in renal parenchymal cells. Moreover, GPR4 was mainly expressed in endothelial cells after renal IR. GPR4 knockdown markedly inhibited CHOP expression and cell apoptosis in the HUVECs after HR treatment. GPR4 blockade attenuated renal injury after IR and reduced the cell apoptosis through the suppression of CHOP expression.
Suppression of Stim1 reduced intracellular calcium concentration and attenuated hypoxia/reoxygenation induced apoptosis in H9C2 cells
Authors: He Fei , Wu Qianfu , Xu Banglong , Wang Xiaocheng , Wu Jixiong , Huang Li , Cheng Jing
Published: November 2017

Objective: Previous studies have demonstrated Stromal interaction molecule 1 (STIM1)-mediated store-operated Ca2+ entry (SOCE) contributes to intracellular Ca2+ accumulation. The present study aimed to investigate the expression of STIM1 and its downstream molecules Orai1/TRPC1 in the context of myocardial ischemia/reperfusion injury (MIRI) and the effect of STIM1 inhibition on Ca2+ accumulation and apoptosis in H9c2 cardiomyocytes subjected to hypoxia/reoxygenation (H/R).

Methods: Expression of STIM1/Orai1/TRPC1 was determined by RT-PCR and Western blot in mice subjected to MIRI and H9C2 cardiomyocytes subjected to H/R. To knock-down STIM1, H9C2 cardiomyocytes was transfected with Stealth SiRNA. Apoptosis was analyzed by both flow cytometry and TUNEL assay. Cell viability was measured by MTT assay. Intracellular Ca2+ concentration was detected by laser scanning confocal microscopy using Fluo-3/AM probe. Furthermore, the opening of mitochondrial permeability transition pore (mPTP) was assessed by coloading with calcein AM and CoCl2, while ROS generation was evaluated using the dye DCFH-DA in H9C2 cardiomyocytes.

Results: Expression of STIM1/Orai1/TRPC1 significantly increased in transcript and translation level after MIRI in vivo and H/R in vitro. In H9C2 cardiomyocytes subjected to H/R, intracellular Ca2+ accumulation significantly increased compared with control group, along with enhanced mPTP opening and elevated ROS generation. However, suppression of STIM1 by SiRNA significantly decreased apoptosis and intracellular Ca2+ accumulation induced by H/R in H9C2 cardiomyocytes, accompanied by attenuated mPTP opening and decreased ROS generation. In addition, suppression of STIM1 increased the Bcl-2/Bax ratio, decreased Orai1/TRPC1, and cleaved caspase-3 expression.

Conclusion: Suppression of STIM1 reduced intracellular calcium level and attenuated hypoxia/reoxygenation induced apoptosis in H9C2 cardiomyocytes. Our findings provide a new perspective in understanding STIM1-mediated calcium overload in the setting of MIRI.
Sub‐synchronous oscillation mechanism and its suppression in MMC‐based HVDC connected wind farms
Authors: Lyu Jing , Cai Xu , Amin Mohammad , Molinas Marta
Published: November 2017

A subsynchronous oscillation (SSO) phenomenon in a wind farm integrated with a modular multilevel converter (MMC)‐based high‐voltage direct current (HVDC) transmission system has been recently observed in the real world. An attempt is made in this paper to contribute to the understanding of the root cause of the SSO in the MMC‐HVDC connected wind farms. For that, the small‐signal impedance model of the MMC is first developed based on the harmonic state‐space (HSS) modelling method. An inherent low‐frequency resonance peak in the MMC excluding any control influence is identified by its terminal impedance. Arguably, this could be the reason why the SSO occurs in the MMC‐HVDC connected wind farms. In addition to that, the influence factors, such as main circuit parameters, controller parameters, and power level, on the stability of the interconnected system are examined, which can provide guidelines for the system design in order to guarantee the stability of the interconnected system. Based on the mechanism analysis, a stabilization control for suppressing the SSO in the MMC‐HVDC based wind farms is also proposed. Finally, the theoretical analysis and stabilization control are validated by both time‐domain simulations and field measurements in a real MMC‐HVDC connected wind farm in China.
Fast inrush voltage and current restraining method for droop controlled inverter during grid fault clearance in distribution network
Authors: Shuai Zhikang , Ge Jun , Huang Wen , Feng Yaojing , Tang Jie
Published: November 2017

Control mode switching strategy of droop controlled inverter can effectively avoid overcurrent during grid fault, but it is easy to cause inrush voltage and current during grid fault clearance, which leads to the failure of fault ride through process of the distribution network. In this study, a new control mode re‐switching method is proposed on the basis of restricting the outputs of the off‐line controllers, which can make sure that the inrush voltage and current are suppressed and return to the normal condition quickly. First, the dynamic characteristics of fault current of droop controlled inverter are analysed. Then, the instantaneous inrush voltage and current caused by the output saturations of voltage controller and power controller before the re‐switching process are mainly discussed. This method takes full advantage of integration of the existing off‐line controllers to limit the output saturations, which can make the inrush problems well solved, and reduce the influence on grid connected inverters and the distribution network. Simulation results verify the validity of the theoretical analysis.
Adaptive beam‐allocation method based on lobe efficacy
Authors: Yu Liang , Cheng Yongmei , Li Song , Zhao Huisheng , Liu Zhunga
Published: November 2017

During the torpedo guidance procedure, homing‐torpedo beam allocation and guidance operate in a fixed allocation mode. However, in the complicated acoustic‐warfare environment, the true target is very likely to release many decoys. The torpedo must constantly detect and track multiple targets at the same time before the actual target is confirmed. Based on the analysis of the environment, this study suggests an efficacy‐computation model on the basis of lobes and a secondary beam‐disposal framework based on beam formation and beam allocation, in addition to the universal norm for lobe classification based on the maximum efficacy. Based on considering four factors simultaneously – target probability, tracking demand, identification needs and task requirements – a comprehensive self‐adaptive beam‐allocation method is proposed. First, the whole beam section is divided into many lobes based on all target positions, and then all the target efficacies in each lobe can be computed. The calculation methods for both the efficacy function of each factor and the overall efficacy function are also provided. The simulation results show that this method can ensure that the stable tracking of multiple targets and the goals is identified simultaneously. This method can provide a rational and effective approach to multiple‐target beam allocation.
Early-Career Surgical Practice for Cerebellopontine Angle Tumors in the Era of Radiosurgery
Authors: Sorrentino Tommaso , Altieri Roberto , Zinis Luca , Stefini Roberto , Panciani Pier , Fontanella Marco , Spena Giannantonio
Published: November 2017

We analyzed the outcomes of patients with large cerebellopontine angle (CPA) tumors treated by a skull-base team in which two surgeons (one neurosurgeon and one otological surgeon) were in the beginning of their careers (<40 years old). Data of patients operated on between April 2012 and March 2016 were reviewed. All factors related to surgical training were considered. Thirty-one patients had vestibular schwannomas, while 26 had meningiomas. Mean tumor diameter was 30.6 mm (range, 23–49 mm) for schwannomas and 35 mm (range, 22–51 mm) for meningiomas. Satisfactory postoperative facial nerve function (House–Brackmann's grade I or II) was achieved in 20 (64.5%) schwannoma patients and 21 (80.7%) meningioma patients. Gross total and near-total resections (residual tumor < 5 mm) were achieved in 21 (67.7%) and 9 (29%) schwannoma patients, respectively. Gross total resection (Simpson's grade II) was achieved in 18 (69.2%) meningioma patients. In both groups, the retrosigmoid approach was the most common approach. Regarding surgical training of the two younger surgeons, during the residency period, they attended high-volume centers for CPA tumors. Application of microsurgical techniques was systematically applied from the beginning of their personal series in every intracranial pathology case. During the first 2 years of the series, they were supervised by more experienced surgeons and followed a stepwise sharing of increasingly difficult surgical phases; by comparing results of this period with the last 2 years of the series, where they acquired a complete autonomy, no relevant difference was detected. Our results suggest that young surgeons may achieve good results even at the beginning of their careers, if specific conditions related to training and mentorship are met.
Theory of molecular nonadiabatic electron dynamics in condensed phases
Authors: Takatsuka Kazuo
Published: November 2017

In light of the rapid progress of ultrafast chemical dynamics driven by the pulse lasers having width as short as several tens of attoseconds, we herein develop a theory of nonadiabatic electron wavepacket dynamics in condensed phases, with which to directly track the dynamics of electronic-state mixing such as electron transfer in liquid solvents. Toward this goal, we combine a theory of path-branching representation for nonadiabatic electron wavepacket dynamics in vacuum {a mixed quantum-classical representation, Yonehara and Takatsuka [J. Chem. Phys. 129, 134109 (2008)]} and a theory of entropy functional to treat chemical dynamics in condensed phases {a mixed dynamical-statistical representation, Takatsuka and Matsumoto [Phys. Chem. Chem. Phys. 18, 1771 (2016)]}. Difficulty and complexity in the present theoretical procedure arise in embedding the Schrödinger equation into classically treated statistical environment. Nevertheless, the resultant equations of motion for electronic-state mixing due to the intrinsic nonadiabatic interactions and solute-solvent interactions, along with the force matrix that drives nuclear branching paths, both turn out to be clear enough to make it possible to comprehend the physical meanings behind. We also discuss briefly the nonvalidness of naive application of the notion of nonadiabatic transition dynamics among free energy surfaces.
Investigation of high density two-dimensional electron gas in Zn-polar BeMgZnO/ZnO heterostructures
Authors: Ding K. , Ullah M. B. , Avrutin V. , Özgür Ü. , Morkoç H.
Published: November 2017

Zn-polar BeMgZnO/ZnO heterostructures grown by molecular beam epitaxy on high resistivity GaN templates producing high-density two-dimensional electron gas (2DEG) are investigated. This is motivated by the need to reach plasmon-longitudinal optical (LO) phonon resonance for attaining minimum LO phonon lifetime. Achievement of high 2DEG concentration in MgZnO/ZnO heterostructures requires growth of the MgZnO barrier at relatively low temperatures, which compromises the ternary quality that in turn hinders potential field effect transistor performance. When this ternary is alloyed further with BeO, the sign of strain in the BeMgZnO barrier on ZnO switches from compressive to tensile, making the piezoelectric and spontaneous polarizations to be additive in the BeMgZnO/ZnO heterostructures much like the Ga-polar AlGaN/GaN heterostructures. As a result, a 2DEG concentration of 1.2 × 1013 cm−2 is achieved in the Be0.03Mg0.41Zn0.56O/ZnO heterostructure. For comparison, a 2DEG concentration of 7.7 × 1012 cm−2 requires 2% Be and 26% Mg in the barrier, whereas the same in the MgZnO/ZnO system would require incorporation of more than 40% Mg into the barrier, which necessitates very low growth temperatures. Our results are consistent with the demands on achieving short LO phonon lifetimes through plasmon-LO phonon resonance for high carrier velocity.
Secondary electron emission yield from high aspect ratio carbon velvet surfaces
Authors: Jin Chenggang , Ottaviano Angelica , Raitses Yevgeny
Published: November 2017

The plasma electrons bombarding a plasma-facing wall surface can induce secondary electron emission (SEE) from the wall. A strong SEE can enhance the power losses by reducing the wall sheath potential and thereby increasing the electron flux from the plasma to the wall. The use of the materials with surface roughness and the engineered materials with surface architecture is known to reduce the effective SEE by trapping the secondary electrons. In this work, we demonstrate a 65% reduction of SEE yield using a velvet material consisting of high aspect ratio carbon fibers. The measurements of SEE yield for different velvet samples using the electron beam in vacuum demonstrate the dependence of the SEE yield on the fiber length and the packing density, which is strongly affected by the alignment of long velvet fibers with respect to the electron beam impinging on the velvet sample. The results of SEE measurements support the previous observations of the reduced SEE measured in Hall thrusters.
Anisotropic bulk SmCo7 nanocrystalline magnets with high energy product
Authors: Song Wenpeng , Li Xiaohong , Lou Li , Hua Yingxin , Zhang Qian , Huang Guangwei , Zhang Xiangyi
Published: November 2017

Realizing grain alignment along easy magnetization axis in bulk SmCo7 nanocrystalline materials is crucial for their development as high-performance high-temperature magnets, yet it remains challenging. Here, we report the fabrication of anisotropic bulk SmCo7 nanocrystalline magnets with a small grain size of ∼20 nm and a (00l) texture using high-pressure thermal compression starting from partially amorphous precursors. The synthesized magnet exhibits a high energy product of 18.4 MGOe, 40% larger than the reported highest value (13 MGOe) for bulk nanostructured SmCo7 magnets, and outperforms its anisotropic coarse-grained counterpart. Moreover, our magnet shows a low coercivity temperature coefficient of β = −0.19%/°C. These findings make an important step toward the fabrication of oriented bulk nanostructures for practical applications.