bluuebunny/crossref_metadata_2025 huggingface dataset:
Réactions réciproques des marchés du beurre, de la margarine et du saindoux en Belgique de 1920 à 1937
Authors: Cools L.-J.
Published: August 2016

La présente étude a comme but principal de rechercher de quelle façon la consommation des trois principales graisses alimentaires, le beurre, la margarine et le saindoux, a évolué pendant la période de 1920–1937, et de déterminer le rapport éventuel entre la consommation et les prix de ces graisses.

Dans plusieurs pays, et principalement aux États-Unis d’Amérique, des études approfondies ont été publiées sur les éléments déterminants de la production et des prix de nombreuses denrées agricoles. Nous rappelons ici surtout les études du Département of Agriculture, de l’Université de Cornell, du Wheat Institutes.

Le beurre cependant, n’est guère traité, malgré son grand intérêt.

Son importance économique saute aux yeux en parcourant le tableau I, lequel, bien que ne relatant pas exactement la production mondiale annuelle du beurre, nous donne toutefois une estimation suffisante de la production annuelle du beurre dans les régions productrices les plus importantes.
La Conjoncture économique de la Belgique et du Luxembourg
Authors: Dupriez Léon-H.
Published: August 2016

Le commentaire des événements survenus en Belgique dans le domaine de l’activité économique sera, comme dans notre dernier diagnostic, assez terne: assurément, le rythme du travail ne se modifie pas sensiblement et le pays végète, depuis le printemps, dans une dépression qui ne paraît pas devoir être profonde. Une observation attentive révélera certes des mouvements significatifs, mais, une fois de plus, l’esprit est attiré par les secousses auxquelles l’organisme financier s’est vu contraint de faire face. Car si le début de mobilisation n’a entraîné que des remous de peu d’amplitude dans l’activité industrielle, il a provoqué, par contre, des demandes assez fortes de numéraire, pour des raisons d’ailleurs objectivement justifiées. Un commentaire approprié des événements se doit de situer d’abord exactement ce qui s’est passé dans ce domaine.

La nature de la tension survenue fin septembre dans le système financier est toute autre que celle de la crise des changes en mai: il s’agissait de faire face à des besoins ayant une origine non économique: de certains côtés, des achats spéciaux, d’autres côtés la constitution d’encaisses plus considérables, à raison de la séparation des familles, des frais exceptionnels à exposer en cas de conflit, des difficultés de retraits de fonds qui pourraient résulter de cette éventualité: bref, une diminution de la vélocité de circulation de la monnaie était imposée par les circonstances et il fallait y faire face sans créer la déflation, c’est-à-dire en faisant appel à l’élasticité du système monétaire.
L’industrie textile belge en 1938
Authors: Capelle Stanislas
Published: August 2016

L’industrie textile belge a ressenti avec une particulière gravité les effets du ralentissement de l’activité économique survenu au courant de l’année 1937, et qui a continué en 1938. C’est ce que démontre notamment l’analyse des indices trimestriels des prix de gros calculés par l’Institut.

Elle permet en effet de constater que le recul des prix s’est produit aussitôt après le mois d’avril 1937, simultanément pour les trois stades de la fabrication : matières premières, demi-produits (fils) et produits finis (tissus et cordages). De ces trois indices, c’est celui des demi-produits qui a baissé le plus; et les produits finis ont baissé presque autant que les matières premières. Cette évolution anormale provient certainement du fait que l’industrie textile belge ne se trouve pas seulement en présence d’une crise due à la conjoncture générale des affaires, mais qu’elle se trouve également en face d’une crise de structure, qu’on ne peut malheureusement qualifier de crise de croissance.
La métallurgie en 1938
Authors: de Strycker Robert
Published: August 2016

Ainsi qu’on pouvait déjà le prévoir il y a un an, l’activité de l’industrie sidérurgique a été, en moyenne, moins intense en 1938 que pendant les douze mois précédents. Dès janvier, la production de la plupart des pays a été moins forte que la moyenne mensuelle de 1937 et la réduction de la production au cours des mois suivants est une des plus rapides que l’on ait jamais observée. Beaucoup d’acheteurs s’étaient presque complètement retirés du marché en sorte que, quelques faibles que nous paraissent les tonnages produits à la fin de l’hiver, ils dépassaient encore le volume des commandes inscrites par les usines pendant cette époque. L’activité s’améliora quelque peu en été et l’on assiste à une progression continue qui se poursuivait encore en décembre.

Les chiffres globaux montrent que la production mondiale d’acier, tout en diminuant en un an d’environ 20 %, reste encore très voisine de son total de 1928. En ce qui concerne la fonte, la réduction est un peu plus forte, de l’ordre de 22 %. Nous croyons que cet écart peut s’expliquer par le fait, déjà signalé l’année dernière, qu’il y eut une véritable disette de mitrailles en 1937; elles étaient relativement plus abondantes l’année dernière. L’écart entre la réduction des tonnages de fonte et d’aciers produits aurait probablement été plus fort, si la politique économique du Gouvernement allemand n’avait obligé les sidérurgistes d’outre-Rhin à diminuer le pourcentage de mitrailles chargées dans leurs fours Martin.
La Conjoncture économique de la Belgique et du Luxembourg
Authors: Dupriez Léon-H.
Published: August 2016

Les derniers mois n’ont pas apporté de changements profonds, ou même caractéristiques, dans la conjoncture économique mondiale. Les espoirs d’un revirement franc, entretenus dans certains milieux à l’approche de saisons déterminées, se sont évanouis — comme ils devaient s’évanouir, car le processus de la reprise connaît surtout des revirements successifs et d’une netteté très discutable au début. Cette désillusion, jointe aux craintes de complications internationales plus susceptibles de surgir au printemps qu’au cours de l’hiver, a réagi défavorablement sur l’esprit d’entreprise et tend à encourager des départs de capitaux européens vers les pays d’outremer : bref, la diminution de la demande industrielle de capitaux provoque certes une liquidité du marché à court terme, mais elle ne crée pas corrélativement une offre de capitaux à long terme. L’un des moteurs d’une reprise économique, sur le plan habituel de l’initiative privée, se trouve donc affaibli en Europe et renforcé outremer.

Dans cette ambiance internationale, on ne pouvait s’attendre à ce que la conjoncture belge prenne une direction nouvelle bien déterminée. Il apparaît, dès lors, plus important de faire en ce moment le point, d’estimer raisonnablement, sans optimisme de commande et sans pessimisme de lassitude, la situation actuelle du pays que de s’appesantir sur les détails des derniers mouvements recensés. C’est à faire cet examen aussi objectif que possible que nous consacrerons le plus clair de cette première chronique de l’année 1939.
La formation du réseau des voies navigables en Belgique
Authors: Urbain Yves
Published: August 2016

Au cours des périodes moderne et contemporaine, deux réseaux navigables différents se sont successivement développés dans chacun des pays occidentaux. Le premier, fluvial et commercial ou agricole, se forme jusque vers la fin du XVIIe siècle. Le deuxième, artificiel et industriel, se développe dès le milieu du XVIIIe siècle.

Entre la formation de ces deux systèmes, se place un temps d’arrêt et de contraction d’une durée et d’une importance variables suivant les pays. Cette période intermédiaire est issue d’une baisse lente des prix, accentuée souvent par une politique d’avilissement du prix des matières premières. L’action des gouvernements modifia, en conséquence, la localisation des entreprises dans le sens d’une réduction des transports pondéreux. Elle provoqua le fractionnement des aires économiques en régions isolées. Elle entraîna la création naturelle ou forcée des manufactures et d’une manière inégale, le perfectionnement de l’agriculture. Ainsi était assurée la prépondérance du produit de valeur dans la circulation. Alors se formèrent les grands réseaux routiers qui, à frais égaux, pouvaient effectuer l’ensemble des transports avec plus de rapidité. Dans ce monde économique atrophié, l’industrie lourde et capitaliste naissante put vivoter jusqu’au moment où la pénurie du bois posa le probleme du combustible, des matériaux de construction et de l’outil. La répartition géographique inégale du charbon, la nature de ce nouveau combustible déplacèrent la question qui retomba dans la domaine des transports et de la métallurgie. Au milieu du XVIIIe siècle, une hausse des prix, quelconque au début, permit l’adaptation de procédés industriels qui n’étaient pas tous nouveaux. La solution du problème des transports par le développement d’un réseau navigable artificiel, l’augmentation ainsi provoquée de la production charbonnière et minérale, la prospérité de l’industrie du bâtiment formèrent une période transitoire dont sortit l’expansion économique de l’époque contemporaine.
La Conjoncture économique de la Belgique et du Luxembourg
Authors: Dupriez Léon-H.
Published: August 2016

Une fois de plus les derniers mois ont été témoins d’une affluence considérable d’or aux États-Unis, en provenance d’Europe: le « Federal Reserve Bulletin » de mai annonce « que les importations d’or aux États-Unis augmentèrent à la suite de l’occupation allemande de la Tchécoslovaquie et que du 15 mars au 26 avril elles furent de 700 millions de dollars (soit 20.650 millions de francs belges). L’allure de l’entrée d’or fut aussi forte que pendant la crise tchécoslovaque six mois plus tôt ». Le stock d’or des États-Unis atteint ainsi 15.258 millions de dollars, pour une circulation monétaire de 6.817 millions.

Ce nouvel afflux d’or ne pouvait contribuer sérieusement à stimuler l’économie américaine, car il représente des capitaux flottants et instables; il n’a fait qu’accroître les réserves déjà pléthoriques du système bancaire. Par contre, il n’est pas douteux que ce fut. un nouveau coup pour les économies européennes, peinant sous la pression d’une lente déflation.
Six Things Dwarf Planets Have Taught Us About the Solar System
Authors: Wendel JoAnna
Published: August 2016

It's been 10 years since Pluto was reclassified as a dwarf planet. But no matter the label, it and its dwarf planet cousins continue to stun researchers with their complexity.
Notch-Hes-1 axis controls TLR7-mediated autophagic death of macrophage via induction of P62 in mice with lupus
Authors: Li Xiaojing , Liu Fei , Zhang Xuefang , Shi Guoping , Ren Jing , Ji Jianjian , Ding Liang , Fan Hongye , Dou Huan , Hou Yayi
Published: August 2016

The increased death of macrophages has been considered as a pathogenic factor for systemic lupus erythematosus (SLE), and dysfunction of autophagy may contribute to improper cell death. However, the effect of autophagy on macrophage during the pathogenesis of SLE is still unclear. Here we found that the death rate and autophagy level of macrophages significantly increased in MRL/lpr lupus-prone mice. Activation of toll-like receptor 7 (TLR7) triggered macrophage death in an autophagy-dependent but caspase-independent way in vitro. Moreover, P62/SQSTM1 is thought to have an essential role in selective autophagy. We also demonstrated that P62/SQSTM1 was required for TLR7-induced autophagy, and knockdown of P62 suppressed R848-induced cell death and LC3II protein accumulation. As an important mediator for cell–cell communication, Notch signaling is responsible for cell-fate decisions. Our results showed that activation of TLR7 also upregulated the expression of Notch1, especially its downstream target gene Hairy and enhancer of split 1 (Hes-1) in macrophages. Of note, we found that Hes-1, as a transcriptional factor, controlled TLR7-induced autophagy by regulating P62 expression. Furthermore, to confirm the above results in vivo, TLR7 agonist imiquimod (IMQ)-induced lupus mouse model was prepared. Splenic macrophages from IMQ-treated mice exhibited increased autophagy and cell death as well as enhanced expressions of Notch1 and Hes-1. Our results indicate that Notch1-Hes-1 signaling controls TLR7-induced autophagic death of macrophage via regulation of P62 in mice with lupus.
A simple non-perturbing cell migration assay insensitive to proliferation effects
Authors: Glenn Honor L. , Messner Jacob , Meldrum Deirdre R.
Published: August 2016

Migration is a fundamental cellular behavior that plays an indispensable role in development and homeostasis, but can also contribute to pathology such as cancer metastasis. Due to its relevance to many aspects of human health, the ability to accurately measure cell migration is of broad interest and numerous approaches have been developed. One of the most commonly employed approaches, because of its simplicity and throughput, is the exclusion zone assay in which cells are allowed to migrate into an initially cell-free region. A major drawback of this assay is that it relies on simply counting cells in the exclusion zone and therefore cannot distinguish the effects of proliferation from migration. We report here a simple modification to the exclusion zone migration assay that exclusively measures cell migration and is not affected by proliferation. This approach makes use of a lineage-tracing vital stain that is retained through cell generations and effectively reads out migration relative to the original, parental cell population. This modification is simple, robust, non-perturbing and inexpensive. We validate the method in a panel of cell lines under conditions that inhibit or promote migration and demonstrate its use in normal and cancer cell lines as well as primary cells.
Absence of food alternatives promotes risk-prone feeding of unpalatable substances in honey bees
Authors: Desmedt Lucie , Hotier Lucie , Giurfa Martin , Velarde Rodrigo , de Brito Sanchez Maria Gabriela
Published: August 2016

The question of why animals sometimes ingest noxious substances is crucial to understand unknown determinants of feeding behaviour. Research on risk-prone feeding behaviour has largely focused on energy budgets as animals with low energy budgets tend to ingest more aversive substances. A less explored possibility is that risk-prone feeding arises from the absence of alternative feeding options, irrespectively of energy budgets. Here we contrasted these two hypotheses in late-fall and winter honey bees. We determined the toxicity of various feeding treatments and showed that when bees can choose between sucrose solution and a mixture of this sucrose solution and a noxious/unpalatable substance, they prefer the pure sucrose solution and reject the mixtures, irrespective of their energy budget. Yet, when bees were presented with a single feeding option and their escape possibilities were reduced, they consumed unexpectedly some of the previously rejected mixtures, independently of their energy budget. These findings are interpreted as a case of feeding helplessness, in which bees behave as if it were utterly helpless to avoid the potentially noxious food and consume it. They suggest that depriving bees of variable natural food sources may have the undesired consequence of increasing their acceptance of food that would be otherwise rejected.
Electrically Controllable Microparticle Synthesis and Digital Microfluidic Manipulation by Electric-Field-Induced Droplet Dispensing into Immiscible Fluids
Authors: Um Taewoong , Hong Jiwoo , Im Do Jin , Lee Sang Joon , Kang In Seok
Published: August 2016

The dispensing of tiny droplets is a basic and crucial process in a myriad of applications, such as DNA/protein microarray, cell cultures, chemical synthesis of microparticles and digital microfluidics. This work systematically demonstrates droplet dispensing into immiscible fluids through electric charge concentration (ECC) method. It exhibits three main modes (i.e., attaching, uniform and bursting modes) as a function of flow rates, applied voltages and gap distances between the nozzle and the oil surface. Through a conventional nozzle with diameter of a few millimeters, charged droplets with volumes ranging from a few μL to a few tens of nL can be uniformly dispensed into the oil chamber without reduction in nozzle size. Based on the features of the proposed method (e.g., formation of droplets with controllable polarity and amount of electric charge in water and oil system), a simple and straightforward method is developed for microparticle synthesis, including preparation of colloidosomes and fabrication of Janus microparticles with anisotropic internal structures. Finally, a combined system consisting of ECC-induced droplet dispensing and electrophoresis of charged droplet (ECD)-driven manipulation systems is constructed. This integrated platform will provide increased utility and flexibility in microfluidic applications because a charged droplet can be delivered toward the intended position by programmable electric control.
Adsorption of Antibiotics on Graphene and Biochar in Aqueous Solutions Induced by π-π Interactions
Authors: Peng Bingquan , Chen Liang , Que Chenjing , Yang Ke , Deng Fei , Deng Xiaoyong , Shi Guosheng , Xu Gang , Wu Minghong
Published: August 2016

The use of carbon based materials on the removal of antibiotics with high concentrations has been well studied, however the effect of this removal method is not clear on the actual concentration of environments, such as the hospital wastewater, sewage treatment plants and aquaculture wastewater. In this study, experimental studies on the adsorption of 7 antibiotics in environmental concentration of aqueous solutions by carbon based materials have been observed. Three kinds of carbon materials have shown very fast adsorption to antibiotics by liquid chromatography–tandem mass spectrometry (LC-MS-MS) detection and the highest removal efficiency of antibiotics could reach to 100% within the range of detection limit. Surprisedly, the adsorption rate of graphene with small specific surface area was stronger than other two biochar and adsorption rate of the two biochar which have approximate specific surface and different carbonization degree, was significantly different. The key point to the present observation were the π-π interactions between aromatic rings on adsorbed substance and carbon based materials by confocal laser scanning microscope observation. Moreover, adsorption energy markedly increased with increasing number of the π rings by using the density functional theory (DFT), showing the particular importance of π-π interactions in the adsorption process.
Distinguishing autocrine and paracrine signals in hematopoietic stem cell culture using a biofunctional microcavity platform
Authors: Müller Eike , Wang Weijia , Qiao Wenlian , Bornhäuser Martin , Zandstra Peter W. , Werner Carsten , Pompe Tilo
Published: August 2016

Homeostasis of hematopoietic stem cells (HSC) in the mammalian bone marrow stem cell niche is regulated by signals of the local microenvironment. Besides juxtacrine, endocrine and metabolic cues, paracrine and autocrine signals are involved in controlling quiescence, proliferation and differentiation of HSC with strong implications on expansion and differentiation ex vivo as well as in vivo transplantation. Towards this aim, a cell culture analysis on a polymer microcavity carrier platform was combined with a partial least square analysis of a mechanistic model of cell proliferation. We could demonstrate the discrimination of specific autocrine and paracrine signals from soluble factors as stimulating and inhibitory effectors in hematopoietic stem and progenitor cell culture. From that we hypothesize autocrine signals to be predominantly involved in maintaining the quiescent state of HSC in single-cell niches and advocate our analysis platform as an unprecedented option for untangling convoluted signaling mechanisms in complex cell systems being it of juxtacrine, paracrine or autocrine origin.
High gene flow between alternative morphs and the evolutionary persistence of facultative paedomorphosis
Authors: Oromi Neus , Michaux Johan , Denoël Mathieu
Published: August 2016

Paedomorphosis and metamorphosis are two major developmental processes that characterize the evolution of complex life cycles in many lineages. Whereas these processes were fixed in some taxa, they remained facultative in others, with alternative phenotypes expressed in the same populations. From a genetic perspective, it is still unknown whether such phenotypes form a single population or whether they show some patterns of isolation in syntopy. This has deep implications for understanding the evolution of the phenotypes, i.e. towards their persistence or their fixation and speciation. Newts and salamanders are excellent models to test this hypothesis because they exhibit both developmental processes in their populations: the aquatic paedomorphs retain gills, whereas the metamorphs are able to colonize land. Using microsatellite data of coexisting paedomorphic and metamorphic palmate newts (Lissotriton helveticus), we found that they formed a panmictic population, which evidences sexual compatibility between the two phenotypes. The high gene flow could be understood as an adaptation to unstable habitats in which phenotypic plasticity is favored over the fixation of developmental alternatives. This makes then possible the persistence of a polyphenism: only metamorphosis could be maintained in case of occasional drying whereas paedomorphosis could offer specific advantages in organisms remaining in water.
Hierarchical organization of functional connectivity in the mouse brain: a complex network approach
Authors: Bardella Giampiero , Bifone Angelo , Gabrielli Andrea , Gozzi Alessandro , Squartini Tiziano
Published: August 2016

This paper represents a contribution to the study of the brain functional connectivity from the perspective of complex networks theory. More specifically, we apply graph theoretical analyses to provide evidence of the modular structure of the mouse brain and to shed light on its hierarchical organization. We propose a novel percolation analysis and we apply our approach to the analysis of a resting-state functional MRI data set from 41 mice. This approach reveals a robust hierarchical structure of modules persistent across different subjects. Importantly, we test this approach against a statistical benchmark (or null model) which constrains only the distributions of empirical correlations. Our results unambiguously show that the hierarchical character of the mouse brain modular structure is not trivially encoded into this lower-order constraint. Finally, we investigate the modular structure of the mouse brain by computing the Minimal Spanning Forest, a technique that identifies subnetworks characterized by the strongest internal correlations. This approach represents a faster alternative to other community detection methods and provides a means to rank modules on the basis of the strength of their internal edges.
A plasmonic colorimetric strategy for visual miRNA detection based on hybridization chain reaction
Authors: Miao Jie , Wang Jingsheng , Guo Jinyang , Gao Huiguang , Han Kun , Jiang Chengmin , Miao Peng
Published: August 2016

In this work, a novel colorimetric strategy for miRNA analysis is proposed based on hybridization chain reaction (HCR)-mediated localized surface plasmon resonance (LSPR) variation of silver nanoparticles (AgNPs). miRNA in the sample to be tested is able to release HCR initiator from a solid interface to AgNPs colloid system by toehold exchange-mediated strand displacement, which then triggers the consumption of fuel strands with single-stranded tails for HCR. The final produced long nicked double-stranded DNA loses the ability to protect AgNPs from salt-induced aggregation. The stability variation of the colloid system can then be monitored by recording corresponding UV-vis spectrum and initial miRNA level is thus determined. This sensing system involves only four DNA strands which is quite simple. The practical utility is confirmed to be excellent by employing different biological samples.
Graphene oxide based DNA nanoswitches as a programmable pH-responsive biosensor
Authors: Luo Fengyan , Xi Qiang , Jiang Jianhui , Yu Ruqin
Published: August 2016

We developed a programmable pH-responsive biosensor by combining the conformational changes of DNA probes and GO-mediated selective adsorption.
Facile one-pot synthesis of carbon/calcium phosphate/Fe3O4 composite nanoparticles for simultaneous imaging and pH/NIR-responsive drug delivery
Authors: Gou Mingyu , Li Shengnan , Zhang Lingyu , Li Lu , Wang Chungang , Su Zhongmin
Published: August 2016

We report herein a facile one-pot synthesis of carbon/calcium phosphate/Fe3O4 composite nanoparticles, which were employed as pH/NIR-responsive drug delivery vehicles for simultaneous MRI and chemo-photothermal therapy.
A new insight into π–π stacking involving remarkable orbital interactions
Authors: Zhao Rundong , Zhang Rui-Qin
Published: August 2016

The importance of orbital interaction in π–π interactions is explored in detail and a unified description of π–π stacking is proposed.
Controllable intramolecular interaction of 3D arranged π-conjugated luminophores based on a POSS scaffold, leading to highly thermally-stable and emissive materials
Authors: Gon Masayuki , Sato Keita , Tanaka Kazuo , Chujo Yoshiki
Published: August 2016

This manuscript describes the inorganic cubic core as an advantageous scaffold for realizing solid-state emissive materials with high thermal stability.
Graphene/nickel aerogel: an effective catalyst for the thermal decomposition of ammonium perchlorate
Authors: Lan Yuanfei , Jin Bixin , Deng Jingke , Luo Yunjun
Published: August 2016

G/Ni aerogels were prepared by a sol–gel method and supercritical CO2 drying. They exhibit a remarkable catalytic performance for the thermal decomposition of AP.
The influence of a dye–TiO2 interface on DSSC performance: a theoretical exploration with a ruthenium dye
Authors: He Ling-Jun , Chen Jie , Bai Fu-Quan , Jia Ran , Wang Jian , Zhang Hong-Xing
Published: August 2016

Slight modification of dye–TiO2 interface structure induces significant changes in the photo-generated current density.
Fabrication of a polymer electrolyte membrane with uneven side chains for enhancing proton conductivity
Authors: Zhang Yunfeng , Li Cuicui , Liu Xupo , Yang Zehui , Dong Jiaming , Liu Yuan , Cai Weiwei , Cheng Hansong
Published: August 2016

Enhancement of proton conductivity of polymer electrolyte membranes was achieved by broadening the proton transfer channels via attaching acid groups to both long and short side chains of polymer electrolytes simultaneously.
Colorimetric and fluorometric dual-mode detection of aniline pollutants based on spiropyran derivatives
Authors: Tian Weiguo , Xue Yinan , Tian Jintao , Gong Peizhen , Dai Jinhui , Wang Xin , Zhu Zhibin
Published: August 2016

The selective UV-vis absorption of spiropyran and the fluorescence quenching of SP-cellulose material induced by aniline were observed and exploited for rapid detection and accurate quantitative determination of aniline pollutants in the environment.
Room-temperature fabrication of multi-deformable perovskite solar cells made in a three-dimensional gel framework
Authors: Ma Mingming , Tang Qunwei , Yang Peizhi , He Benlin
Published: August 2016

Ultraflexible perovskite solar cells are made by absorbing solar cell materials into 3D gel framework, yielding enhanced photovoltaic performances under deformations.
Enhanced dielectric performance of polyvinylidene fluoride composites with an all-carbon hybrid architecture: vertically aligned carbon nanotube arrays on graphite nanoplatelets
Authors: Zhao Hang , Yang Min-Hao , He Delong , Bai Jinbo
Published: August 2016

The dielectric properties of PVDF-based percolative composites can be strongly improved by loading novel conductive units with a well-designed micro-architecture.
Molecular basis of the osmolyte effect on protein stability: a lesson from the mechanical unfolding of lysozyme
Authors: Adamczak Beata , Wieczór Miłosz , Kogut Mateusz , Stangret Janusz , Czub Jacek
Published: August 2016

Osmolytes are a class of small organic molecules that shift the protein folding equilibrium. For this reason, they are accumulated by organisms under environmental stress and find applications in biotechnology where proteins need to be stabilized or dissolved. However, despite years of research, debate continues over the exact mechanisms underpinning the stabilizing and denaturing effect of osmolytes. Here, we simulated the mechanical denaturation of lysozyme in different solvent conditions to study the molecular mechanism by which two biologically relevant osmolytes, denaturing (urea) and stabilizing (betaine), affect the folding equilibrium. We found that urea interacts favorably with all types of residues via both hydrogen bonds and dispersion forces, and therefore accumulates in a diffuse solvation shell around the protein. This not only provides an enthalpic stabilization of the unfolded state, but also weakens the hydrophobic effect, as hydrophobic forces promote the association of urea with nonpolar residues, facilitating the unfolding. In contrast, we observed that betaine is excluded from the protein backbone and nonpolar side chains, but is accumulated near the basic residues, yielding a nonuniform distribution of betaine molecules at the protein surface. Spatially resolved solvent–protein interaction energies further suggested that betaine behaves in a ligand- rather than solvent-like manner and its exclusion from the protein surface arises mostly from the scarcity of favorable binding sites. Finally, we found that, in the presence of betaine, the reduced ability of water molecules to solvate the protein results in an additional enthalpic contribution to the betaine-induced stabilization.
Frequency control of self‐sustained push‐pull resonant converter using effective parasitic capacitances
Authors: Tian J. , Hu A.P.
Published: August 2016

A method to control the frequency of a self‐sustained push‐pull converter at megahertz (MHz) level is proposed by utilising the parasitic capacitances of the circuit. As the equivalent parasitic capacitance and the frequency of the converter can be controlled by a DC voltage, the converter works as a voltage‐controlled oscillator and a phase locked loop (PLL) controller is developed to lock in the zero‐voltage switching frequency under circuit parameter variations such as the load, the coupling coefficient etc. The effect of the parasitic capacitances on the operating frequency and why the DC voltage can control it are analysed in details with equivalent circuit analysis and simulation study. Practical experiments demonstrate that the PLL controller can lock the operating frequency within 20–30 MHz with relatively good waveforms.
Multi‐functional hybrid active power converter and its industrial application for electrolytic copper‐foil
Authors: He Zhixing , Ma Fujun , Li Mingshen , Xu Qianming , Zhou Fayun , Yue Yufei
Published: August 2016

To meet the requirements of high‐power compensating occasion such as electrochemical industries, a multifunctional hybrid active power converter (HAPC) with LC series filter is studied to effectively integrate functions of rectification and power compensation. HAPC can be used as a high‐power pulse width modulation rectifier to supply its dc load, meanwhile, it can also compensate large amount of reactive and harmonic current without increasing the voltage rating of itself. A compound current control method for HAPC is introduced so as to improve the dynamic tracking performance. The current and voltage dual closed‐loop system of HAPC is built in s domain, and the detailed control parameters are designed to tune control performance further. Finally, a set of 800 kVA HAPC system for electrolytic copper‐foil is developed. The results show that the HAPC system can achieve expected operation performance and largely improves power quality of power grid.
Optimum coherent detection in homogenous K‐distributed clutter
Authors: Shi Sai‐Nan , Shui Peng‐Lang
Published: August 2016

In this study, the optimum coherent detector in homogeneous K‐distributed clutter is derived. It is named the Hom‐OKD to show its relationship with the optimum K‐distributed detector (OKD) under highly heterogeneous K‐distributed clutter. The Hom‐OKD has a different expression from the OKD because the received vectors at the reference cells are used as a part of the hypotheses. The Hom‐OKD is shown to be constant false alarm rate (CFAR) with respect to speckle covariance matrix, Doppler steering vector, and the scale parameter of the gamma texture. Moreover, the adaptive Hom‐OKD using a non‐iterative maximum likelihood estimate of speckle covariance matrix is given and is proved to have the same CFAR property as the Hom‐OKD. Under homogeneous K‐distributed clutter environments, the adaptive Hom‐OKD provides better detection performance than the adaptive OKD owing to the fact that the texture information conveyed by the secondary data at the reference cells is fully exploited. Simulated experiments are used to verify the optimality of the Hom‐OKD. Experiments using real sea clutter data are made to show that the adaptive OKD and adaptive Hom‐OKD are complementary. The former surpasses the latter for highly heterogeneous sea clutter and the situation is converse for homogeneous sea clutter.
Surface charge and flashover characteristics of fluorinated PP under pulse voltage
Authors: Du Boxue , Huang Penghao , Xing Yunqi
Published: August 2016

Polypropylene (PP), with low loss and high dielectric strength, is widely used as dielectric for the metallised film capacitor (MFC). The electric ageing and dielectric breakdown of the dielectrics under high‐voltage stress is a major concern in the research on polymer materials. Surface discharge and flashover may happen on the PP film between the metallised segments in MFCs, which can influence the dielectric property and cause the breakdown of insulation. Fluorination is effective on modifying the surface characteristics of the polymers, meanwhile retaining the bulk properties. The effects of direct fluorination on the surface charge and flashover characteristics of PP films under pulse voltage are experimented in this study. The samples with different fluorination time were prepared. Surface charging was performed by corona discharge using repetitive pulse power, which was applied to measure the surface flashover voltage as well. The experimental results indicated that the surface charge and flashover voltage were strongly correlated with the charge polarity, pulse frequency and fluorination time. It was suggested that the fluorination of certain time could significantly improve the decay rate of the surface charge as well as the surface flashover voltage of PP samples.
Synthesis of an Advanced Fragment of (+)-Trienomycinol
Authors: Choppin Sabine , Barbarotto Marie , Obringer Michel , Colobert Françoise
Published: August 2016

The synthesis of the fully functionalized eastern fragment of trienomycins A–F, ansamycin antibiotics is described. A key step involves a peptidic coupling between a sulfonyl aniline and an enantiopure carboxylic acid obtained by a completely diastereoselective reduction of a β-ketosulfoxide to generate the stereogenic carbinol. Studies on the coupling with the western part were also performed, giving access to an advanced fragment of trienomycinol.
A hybrid-drive nonisobaric-ignition scheme for inertial confinement fusion
Authors: He X. T. , Li J. W. , Fan Z. F. , Wang L. F. , Liu J. , Lan K. , Wu J. F. , Ye W. H.
Published: August 2016

A new hybrid-drive (HD) nonisobaric ignition scheme of inertial confinement fusion (ICF) is proposed, in which a HD pressure to drive implosion dynamics increases via increasing density rather than temperature in the conventional indirect drive (ID) and direct drive (DD) approaches. In this HD (combination of ID and DD) scheme, an assembled target of a spherical hohlraum and a layered deuterium-tritium capsule inside is used. The ID lasers first drive the shock to perform a spherical symmetry implosion and produce a large-scale corona plasma. Then, the DD lasers, whose critical surface in ID corona plasma is far from the radiation ablation front, drive a supersonic electron thermal wave, which slows down to a high-pressure electron compression wave, like a snowplow, piling up the corona plasma into high density and forming a HD pressurized plateau with a large width. The HD pressure is several times the conventional ID and DD ablation pressure and launches an enhanced precursor shock and a continuous compression wave, which give rise to the HD capsule implosion dynamics in a large implosion velocity. The hydrodynamic instabilities at imploding capsule interfaces are suppressed, and the continuous HD compression wave provides main pdV work large enough to hotspot, resulting in the HD nonisobaric ignition. The ignition condition and target design based on this scheme are given theoretically and by numerical simulations. It shows that the novel scheme can significantly suppress implosion asymmetry and hydrodynamic instabilities of current isobaric hotspot ignition design, and a high-gain ICF is promising.
Reproducible and controllable induction voltage adder for scaled beam experiments
Authors: Sakai Yasuo , Nakajima Mitsuo , Horioka Kazuhiko
Published: August 2016

A reproducible and controllable induction adder was developed using solid-state switching devices and Finemet cores for scaled beam compression experiments. A gate controlled MOSFET circuit was developed for the controllable voltage driver. The MOSFET circuit drove the induction adder at low magnetization levels of the cores which enabled us to form reproducible modulation voltages with jitter less than 0.3 ns. Preliminary beam compression experiments indicated that the induction adder can improve the reproducibility of modulation voltages and advance the beam physics experiments.
Multi-frequency recirculating planar magnetrons
Authors: Greening Geoffrey B. , Jordan Nicholas M. , Exelby Steven C. , Simon David H. , Lau Y. Y. , Gilgenbach Ronald M.
Published: August 2016

The multi-frequency recirculating planar magnetron (MFRPM) is the first magnetron capable of simultaneous generation of significantly different output frequencies (1 and 2 GHz) in a single operating pulse. Design and simulation of a prototype MFRPM were followed by hardware fabrication and experimental verification using the Michigan Electron Long Beam Accelerator with a Ceramic insulator at −300 kV, 1–5 kA, and 0.14–0.23 T axial magnetic field. Preliminary results demonstrated simultaneous generation of microwave pulses near 1 GHz and 2 GHz at powers up to 44 MW and 21 MW, respectively, with peak total efficiencies up to 9%.
Towards electromechanical computation: An alternative approach to realize complex logic circuits
Authors: Hafiz M. A. A. , Kosuru L. , Younis M. I.
Published: August 2016

Electromechanical computing based on micro/nano resonators has recently attracted significant attention. However, full implementation of this technology has been hindered by the difficulty in realizing complex logic circuits. We report here an alternative approach to realize complex logic circuits based on multiple MEMS resonators. As case studies, we report the construction of a single-bit binary comparator, a single-bit 4-to-2 encoder, and parallel XOR/XNOR and AND/NOT logic gates. Toward this, several microresonators are electrically connected and their resonance frequencies are tuned through an electrothermal modulation scheme. The microresonators operating in the linear regime do not require large excitation forces, and work at room temperature and at modest air pressure. This study demonstrates that by reconfiguring the same basic building block, tunable resonator, several essential complex logic functions can be achieved.
Bandwidth enhancement of MgZnO-based MSM photodetectors by inductive gain peaking
Authors: Wang Ping , Guo Xinlu , Guo Lixin , He Jingfang , Yang Yintang , Zhang Zhiyong
Published: August 2016

For high-speed optical communication applications, the bandwidth of photodetector would be a key limitation. In this work, the bandwidth property of MgZnO-based Metal-Semiconductor-Metal (MSM) photodetector considering RC and transit limitations is investigated on the basis of the series and enhanced gain peaked photodetector circuits proposed by us with different finger widths. To ensure the accuracy of parameters, the high-filed transportation characteristics of MgZnO are investigated by a three-valley ensemble Monte Carlo simulation combined with first principle calculations. The results show that the gain peaking technique, especially the enhanced gain peaking, can improve the bandwidth of MgZnO MSM photodetector to a maximum value of 61.28 GHz, corresponding to a bandwidth enhancement of 49% without undesired effects. Three-dimensional electromagnetic computation is further performed to design and simulate the on-chip-inductor. The value of the simulated inductor is approximately 0.0529 nH, which is in good agreement with the designed value of 0.0569 nH. This work benefits the development of high speed MgZnO MSM photodetector.
Generation of ultra-intense gamma-ray train by QED harmonics
Authors: Liu Chen , Shen Baifei , Zhang Xiaomei , Ji Liangliang , Wang Wenpeng , Xu Jiancai , Zhao Xueyan , Yi Longqing , Shi Yin , Zhang Lingang , Xu Tongjun , Pei Zhikun , Xu Zhizhan
Published: August 2016

In nonlinear media, photons may combine into a photon of energy and momentum of all those photons. This process, called harmonic generation, happens in nonlinear crystal, gas, and relativistic plasma. When the laser intensity reaches 1022 W/cm2, QED effects appear and play a significant role in the harmonic generation. In contrast to the gas and relativistic high-order harmonic generation processes, harmonics influenced by QED effects are usually not coherent because of the characteristic of random radiation, while the property of high intensity and ultra-short duration is conserved. In this work, the generation of high-order harmonics with QED effects is investigated by one- and two-dimensional particle-in-cell simulations. Studies have shown that interacting with a laser pulse with the intensity of I=5.35×1023 W/cm2, such harmonics can produce ultra-short gamma-ray train with periodic structures. The period of gamma-ray train is half of the laser period, and the peak intensity is 1.4×1022 W/cm2 from one-dimensional simulation when ions are considered immobile. This new harmonic production with QED effects are crucial to light-matter interaction in strong field and can be verified in experiments by 10 PW laser facilities in the near future.
Helicity and field dependent magnetization dynamics of ferromagnetic Co/Pt multilayers
Authors: Tsema Yu. , Kichin G. , Hellwig O. , Mehta V. , Kimel A. V. , Kirilyuk A. , Rasing Th.
Published: August 2016

We present helicity and field dependent magnetization dynamics of ferromagnetic Co/Pt multilayers, suitable for all-optical helicity-dependent switching. Employing single-shot time-resolved magneto-optical Kerr effect imaging, our study demonstrates an ultra-fast quenching of the magnetization after a single 60 fs laser pulse excitation followed by a recovery. Full demagnetization occurs within 1 ps after laser excitation. The magnetization dynamics reveals a small helicity dependence caused by magnetic circular dichroism. When an external magnetic field is applied, a heat-assisted magnetization reversal occurs on a nanosecond time scale.
Ultrathin phase-change coatings on metals for electrothermally tunable colors
Authors: Bakan Gokhan , Ayas Sencer , Saidzoda Tohir , Celebi Kemal , Dana Aykutlu
Published: August 2016

Metal surfaces coated with ultrathin lossy dielectrics enable color generation through strong interferences in the visible spectrum. Using a phase-change thin film as the coating layer offers tuning the generated color by crystallization or re-amorphization. Here, we study the optical response of surfaces consisting of thin (5–40 nm) phase-changing Ge2Sb2Te5 (GST) films on metal, primarily Al, layers. A color scale ranging from yellow to red to blue that is obtained using different thicknesses of as-deposited amorphous GST layers turns dim gray upon annealing-induced crystallization of the GST. Moreover, when a relatively thick (>100 nm) and lossless dielectric film is introduced between the GST and Al layers, optical cavity modes are observed, offering a rich color gamut at the expense of the angle independent optical response. Finally, a color pixel structure is proposed for ultrahigh resolution (pixel size: 5 × 5 μm2), non-volatile displays, where the metal layer acting like a mirror is used as a heater element. The electrothermal simulations of such a pixel structure suggest that crystallization and re-amorphization of the GST layer using electrical pulses are possible for electrothermal color tuning.
Position dependent optical coupling between single quantum dots and photonic crystal nanocavities
Authors: Kuruma K. , Ota Y. , Kakuda M. , Takamiya D. , Iwamoto S. , Arakawa Y.
Published: August 2016

We demonstrate precise and quick detection of the positions of quantum dots (QDs) embedded in two-dimensional photonic crystal nanocavities. We apply this technique to investigate the QD position dependence of the optical coupling between the QD and the nanocavity. We use a scanning electron microscope (SEM) operating at a low acceleration voltage to detect surface bumps induced by the QDs buried underneath. This enables QD detection with a sub-10 nm precision. We then experimentally measure the vacuum Rabi spectra to extract the optical coupling strengths (gs) between single QDs and cavities, and compare them to the values estimated by a combination of the SEM-measured QD positions and electromagnetic cavity field simulations. We found a highly linear relationship between the local cavity field intensities and the QD-cavity gs, suggesting the validity of the point dipole approximation used in the estimation of the gs. The estimation using SEM has a small standard deviation of ±6.2%, which potentially enables the high accuracy prediction of g prior to optical measurements. Our technique will play a key role for deeply understanding the interaction between QDs and photonic nanostructures and for advancing QD-based cavity quantum electrodynamics.
Effects of ethephon on anatomical changes in sunflower (Helianthus annuus L.) stems associated with lodging
Authors: Mangieri Mariano A. , Mantese Anita I. , Schürmann Alejandro Alvarez , Chimenti Claudio A.
Published: August 2016

Stem lodging causes significant losses in crops of cereals and oilseeds. The aim of the present study was to identify the anatomical causes that generate differences in response to stem lodging in sunflower. Two sunflower hybrids (Stay-Green, resistant to stem lodging; Zenit, susceptible to stem lodging) were grown at three crop population densities and artificially lodged at two advanced ontogeny stages (R7 and R8), which were preceded by ethephon application near the flower button stage (R1). Measurements included stem failure moment of force (Bs), thickness of primary and secondary structures in the stem lodging zone (t), diameter of the stem lodging zone (di), sclerenchyma packages area (sp), secondary xylem tissue area (xt) and yield. Stay-Green had significantly higher values for Bs, t, di, sp and xt. At higher crop densities and more advanced ontogeny stages these parameters were reduced, favouring stem lodging, although the effects were ameliorated by ethephon application through anatomical modifications. Zenit exhibited the greatest responses to ethephon application. The present study is the first field study identifying anatomical changes causing stem lodging and intraspecific variability in sunflowers. The information provided can be used by geneticists in selection programs for stem lodging tolerance in the context of increasing crop population densities to improve sunflower yield.