bluuebunny/crossref_metadata_2025 huggingface dataset:
Assessment and Diagnosis of Excessive Daytime Sleepiness
Authors: Bogan Richard K.
Published: August 2016

The symptoms of excessive daytime sleepiness (EDS) need to be assessed both clinically and with objective diagnostics. As with any other medical disorder, when patients present with excessive sleepiness, the first step is to determine the chief complaint. The spectrum of clinical presentations for EDS is wide, and patients may complain of fatigue, low energy, laziness, apathy, lethargy, poor memory, reduced concentration, reduced attention, irritability, poor performance in work/school, automatic behavior, frequent accidents, drowsiness, and/or sleep attacks. Oftentimes patients do not recognize their own excessive sleepiness and will not quantify the problem unless they are specifically asked if they are sleepy. Some of these patients only present because they have been referred by their employers due to their excessive sleepiness.

After the patient has noted his chief complaint, the clinician should assess the patient's score on the Epworth Sleeping Scale (ESS) on a quantifiable basis. The ESS is a self-administered questionnaire used to rate the severity of EDS. Respondents are asked to use a numeric scale from 0 to 3, corresponding to the likelihood (never, slight, moderate, and high) that they may fall asleep in eight given situations (Slide 1). An ESS score can range from 0 to 24. A score >9 indicates an abnormal level of sleepiness. A score >14 suggests marked sleepiness. Most patients with narcolepsy will score in this range. The normal range varies for different sleep disorders (Slide 2).
Delirium and Isolated Angiitis of the Central Nervous System: A Case Report and Review
Authors: Carandang Carlo G. , Grant Allison L.
Published: August 2016

Central nervous system (CNS) vasculitis is a rare entity, especially when it occurs in isolation; it is seen more commonly as part of a multisystem vasculitis. Common presenting symptoms include persistent headache, encephalopathy, and multifocal signs. We discuss the case of a 68-year-old female who presented twice in 1 month with confusion and choreaform movements. Extensive workup was negative for a connective tissue disease or other conditions in the differential, including neurosarcoidosis, Creutzfeldt-Jakob disease, and neurosyphilis. The only significant findings were elevated erythrocyte sedimentation rate, inflammatory signs in the CNS, and diffuse slowing of the electroencephalogram. A presumptive diagnosis of isolated angiitis of the central nervous system (IACNS) was made and the patient was successfully treated with steroids. She recovered fully with no residual symptoms. The diagnosis of IACNS is often difficult given there are no definitive laboratory investigations or pathognomonic presentation. However, a series of signs, symptoms, and laboratory findings have been proposed that are helpful in making the diagnosis. To our knowledge, IACNS presenting primarily with delirium has not been previously reported in the literature. The diagnosis of IACNS is purely speculative for this case, as the gold standard for diagnosis, a leptomeningeal cortical biopsy, was not performed.
Conclusion: The Future of Single-Isomer Pharmacology
Authors: Rosenbaum Jerrold F.
Published: August 2016

Taken together, the articles gathered in this supplement underscore the major role in drug development that single-isomer science can play—a role that will undoubtedly take on a greater importance in the future. While the chirality of certain pharmacologically active molecules has been recognized for almost a century, it is only in recent years that drug synthesis and chiral separation techniques have advanced far enough to allow meaningful comparisons among enantiomers. Now that these methods are broadly available, the potential applications of single isomer drug development are considerable.

Numerous examples from a range of therapeutic areas confirm that single enantiomers can enhance clinical efficacy, reduce adverse effects, cause fewer interactions with other drugs, and minimize response variations among patients by offering more predictable pharmacokinetics and greater selectivity. In some cases, these advantages are simply due to the removal of an inactive enantiomer, but in other cases, a given dose of a single isomer offers greater benefits when administered alone than when administered as the racemic mixture, suggesting that the opposite enantiomer (the distomer) actually has detracting effects. As the papers by Drs. Gal and Hurt explain, the different activities of a pair of enantiomers are usually traceable to stereochemical differences in the way they interact with chiral macromolecules such as enzymes, transport systems, and receptors.
Bipolar Disorder in Children and Adolescents
Authors: Wolf Dwight V. , Wagner Karen Dineen
Published: August 2016

There is increased recognition that bipolar disorder has an early age of onset. The prevalence of bipolar disorder in prepubertal children has not been determined, however the prevalence in adolescence is ˜1%. Bipolar disorder in children poses a diagnostic challenge since the symptoms may differ from those in late adolescence and adulthood. Comorbid disorders, such as attention-deficit/hyperactivity disorder, further complicate both the diagnosis and course of the disorder. There is increasing evidence of the chronicity and severity of this disorder in youths. Bipolar disorder significantly disrupts a child's psychosocial development including impairments in academic functioning, family functioning, and relationship with peers. Although this disorder has significant morbidity in children and adolescents, there is a paucity of controlled studies to assess the efficacy and safety of mood stabilizers in the treatment of this disorder in youths. The treatment literature consists largely of case studies, retrospective chart reviews, and open-label studies. There is a compelling need for double-blind, placebo-controlled trials to determine whether commonly used medications to treat this disorder are significantly superior to placebo. Since many children in clinical practice require more than one psychotropic medication to adequately manage this disorder, studies of combination treatments are warranted. This review will provide an overview of the literature of bipolar disorder in children and adolescents, including discussion of the prevalence, diagnosis, epidemiology, course of the illness, and treatment issues.
Safety Considerations in Pharmacotherapy of Bipolar Disorder
Authors: Masand Prakash S. , Fazal Farhan S. , Patkar Ashwin A.
Published: August 2016

Bipolar disorder is a chronic, frequently relapsing illness with a prevalence of 1.2% to 3.4% in the general population. It is associated with high disability, higher comorbidity due to medical illnesses, and significant social and economical consequences for patients, their families, and society. The episodic nature of this disease warrants rational use of medications and proper monitoring for adverse events. Various drug classes, such as mood stabilizers, antipsychotics, benzodiazepines, and antidepressants, are used for the acute and maintenance treatment of bipolar disorder. Each group of drugs is associated with wide array of adverse events and drug interactions, which are the main hurdles in treatment outcome and compliance. Common side effects seen with several agents, particularly antipsychotics, are somnolence, weight gain, extrapyramidal symptoms, dyslipidemia, type-2 diabetes, and hyperprolactinemia. Major drug interactions are seen with drugs such as carbamazepine, due to hepatic enzyme induction. Adverse effects such as somnolence are tolerability concerns and can be managed easily; others, such as diabetes mellitus, are safety concerns. It is prudent to have precise knowledge of the individual drug's side-effect profile, pharmacokinetics, and pharmacodynamics, to plan a treatment regimen. More research is needed to understand potential rish of various drugs and to devise and incorporate monitoring protocols in the treatment regimen.
Il Symptom Questionnaire come strumento di screening nei contesti sanitari di base
Authors: Rucci Paola , de Marco Piero , Bivi Raffaella
Published: August 2016

Objective. - To test by means of ROC analysis the performance of the Symptom Questionnaire (SQ) of Kellner and Fava against an interview designed for making DSM-III diagnoses in 517 subjects. To analyse the trend of SQ scores at 3 months, 1 year and 2 years after the first interview in a sample of 112 persons. Design. - Cross-sectional and longitudinal analysis of the distributions of SQ scores in DSM-III cases and in non-cases. Setting. - General practice, hospital medical wards and emergency departments of Regione Emilia Romagna. Main outcome measures. - Symptom Questionnaire, Bech Mini-compendium to formulate DSM-III diagnoses. Results. - The SQ reached high sensitivity and specificity levels (80%, 76% in general practice, 86%, 74% in hospital medical wards, 83%, 85% in emergency departments with the cut-off scores of 24, 24 and 26, respectively). SQ scores show a similar trend in cases and in non-cases, with a significant drop at three months. Conclusions. - The SQ seems to be an adequate screening tool in the above-mentioned settings, but its length and the assistance sometimes needed during the compilation make its use in the emergency departments problematic.
Mechanistic stratification in electroactive biofilms of Geobacter sulfurreducens mediated by pilus nanowires
Authors: Steidl Rebecca J. , Lampa-Pastirk Sanela , Reguera Gemma
Published: August 2016

Electricity generation by Geobacter sulfurreducens biofilms grown on electrodes involves matrix-associated electron carriers, such as c-type cytochromes. Yet, the contribution of the biofilm’s conductive pili remains uncertain, largely because pili-defective mutants also have cytochrome defects. Here we report that a pili-deficient mutant carrying an inactivating mutation in the pilus assembly motor PilB has no measurable defects in cytochrome expression, yet forms anode biofilms with reduced electroactivity and is unable to grow beyond a threshold distance (∼10 μm) from the underlying electrode. The defects are similar to those of a Tyr3 mutant, which produces poorly conductive pili. The results support a model in which the conductive pili permeate the biofilms to wire the cells to the conductive biofilm matrix and the underlying electrode, operating coordinately with cytochromes until the biofilm reaches a threshold thickness that limits the efficiency of the cytochrome pathway but not the functioning of the conductive pili network.
Correction: Corrigendum: NFATc1 supports imiquimod-induced skin inflammation by suppressing IL-10 synthesis in B cells
Authors: Alrefai Hani , Muhammad Khalid , Rudolf Ronald , Pham Duong Anh Thuy , Klein-Hessling Stefan , Patra Amiya K. , Avots Andris , Bukur Valesca , Sahin Ugur , Tenzer Stefan , Goebeler Matthias , Kerstan Andreas , Serfling Edgar
Published: August 2016

Nature Communications 7 Article number: 11724 doi: 10.1038/ncomms11724(2016); Published: 25 May 2016; Updated: 2 August 2016. The affiliation details for Amiya K. Patra are incomplete in this Article. The correct affiliations are given below: Institute of Translational and Stratified Medicine, Peninsula Schools of Medicine and Dentistry, University of Plymouth, Plymouth Science Park, Research Way, Plymouth PL6 8BU, UK.
Ancient landscapes and the relationship with microbial nitrification
Authors: Jenkins Sasha N. , Murphy Daniel V. , Waite Ian S. , Rushton Steven P. , O’Donnell Anthony G.
Published: August 2016

Ammonia oxidizing archaea (AOA) and bacteria (AOB) drive nitrification and their population dynamics impact directly on the global nitrogen cycle. AOA predominate in the majority of soils but an increasing number of studies have found that nitrification is largely attributed to AOB. The reasons for this remain poorly understood. Here,amoAgene abundance was used to study the distribution of AOA and AOB in agricultural soils on different parent materials and in contrasting geologic landscapes across Australia (n = 135 sites). AOA and AOB abundances separated according to the geologic age of the parent rock with AOB higher in the more weathered, semi-arid soils of Western Australia. AOA dominated the younger, higher pH soils of Eastern Australia, independent of any effect of land management and fertilization. This differentiation reflects the age of the underlying parent material and has implications for our understanding of global patterns of nitrification and soil microbial diversity. Western Australian soils are derived from weathered archaean laterite and are acidic and copper deficient. Copper is a co-factor in the oxidation of ammonia by AOA but not AOB. Thus, copper deficiency could explain the unexpectedly low populations of AOA in Western Australian soils.
The differential short- and long-term effects of HIV-1 latency-reversing agents on T cell function
Authors: Clutton G. , Xu Y. , Baldoni P. L. , Mollan K. R. , Kirchherr J. , Newhard W. , Cox Kara , Kuruc J. D. , Kashuba A. , Barnard R. , Archin N. , Gay C. L. , Hudgens M. G. , Margolis D. M. , Goonetilleke N.
Published: August 2016

Despite the extraordinary success of HIV-1 antiretroviral therapy in prolonging life, infected individuals face lifelong therapy because of a reservoir of latently-infected cells that harbor replication competent virus. Recently, compounds have been identified that can reverse HIV-1 latency in vivo. These latency- reversing agents (LRAs) could make latently-infected cells vulnerable to clearance by immune cells, including cytolytic CD8+ T cells. We investigated the effects of two leading LRA classes on CD8+ T cell phenotype and function: the histone deacetylase inhibitors (HDACis) and protein kinase C modulators (PKCms). We observed that relative to HDACis, the PKCms induced much stronger T cell activation coupled with non-specific cytokine production and T cell proliferation. When examining antigen-specific CD8+ T cell function, all the LRAs except the HDACi Vorinostat reduced, but did not abolish, one or more measurements of CD8+ T cell function. Importantly, the extent and timing of these effects differed between LRAs. Panobinostat had detrimental effects within 10 hours of drug treatment, whereas the effects of the other LRAs were observed between 48 hours and 5 days. These observations suggest that scheduling of LRA and CD8+ T cell immunotherapy regimens may be critical for optimal clearance of the HIV-1 reservoir.
Lysine-specific histone demethylase 1 inhibition promotes reprogramming by facilitating the expression of exogenous transcriptional factors and metabolic switch
Authors: Sun Hao , Liang Lining , Li Yuan , Feng Chengqian , Li Lingyu , Zhang Yixin , He Songwei , Pei Duanqing , Guo Yunqian , Zheng Hui
Published: August 2016

Lysine-specific histone demethylase 1 (LSD1) regulates histone methylation and influences the epigenetic state of cells during the generation of induced pluripotent stem cells (iPSCs). Here we reported that LSD1 inhibition via shRNA or specific inhibitor, tranylcypromine, promoted reprogramming at early stage via two mechanisms. At early stage of reprogramming, LSD1 inhibition increased the retrovirus-mediated exogenous expression of Oct4, Klf4 and Sox2 by blocking related H3K4 demethylation. Since LSD1 inhibition still promoted reprogramming even when iPSCs were induced with small-molecule compounds in a virus-free system, additional mechanisms should be involved. When RNA-seq was used for analysis, it was found that LSD1 inhibition reversed some gene expression changes induced by OKS, which subsequently promoted reprogramming. For example, by partially rescuing the decreased expression of Hif1α, LSD1 inhibition reversed the up-regulation of genes in oxidative phosphorylation pathway and the down-regulation of genes in glycolysis pathway. Such effects facilitated the metabolic switch from oxidative phosphorylation to glycolysis and subsequently promoted iPSCs induction. In addition, LSD1 inhibition also promoted the conversion from pre-iPSCs to iPSCs by facilitating the similar metabolic switch. Therefore, LSD1 inhibition promotes reprogramming by facilitating the expression of exogenous transcriptional factors and metabolic switch.
Addressing proteolytic efficiency in enzymatic degradation therapy for celiac disease
Authors: Rey Martial , Yang Menglin , Lee Linda , Zhang Ye , Sheff Joey G. , Sensen Christoph W. , Mrazek Hynek , Halada Petr , Man Petr , McCarville Justin L , Verdu Elena F. , Schriemer David C.
Published: August 2016

Celiac disease is triggered by partially digested gluten proteins. Enzyme therapies that complete protein digestion in vivo could support a gluten-free diet, but the barrier to completeness is high. Current options require enzyme amounts on the same order as the protein meal itself. In this study, we evaluated proteolytic components of the carnivorous pitcher plant (Nepenthes spp.) for use in this context. Remarkably low doses enhance gliadin solubilization rates and degrade gliadin slurries within the pH and temporal constraints of human gastric digestion. Potencies in excess of 1200:1 (substrate-to-enzyme) are achieved. Digestion generates small peptides through nepenthesin and neprosin, the latter a novel enzyme defining a previously-unknown class of prolyl endoprotease. The digests also exhibit reduced TG2 conversion rates in the immunogenic regions of gliadin, providing a twin mechanism for evading T-cell recognition. When sensitized and dosed with enzyme-treated gliadin, NOD/DQ8 mice did not show intestinal inflammation, when compared to mice challenged with only pepsin-treated gliadin. The low enzyme load needed for effective digestion suggests that gluten detoxification can be achieved in a meal setting, using metered dosing based on meal size. We demonstrate this by showing efficient antigen processing at total substrate-to-enzyme ratios exceeding 12,000:1.
From discrete molecule, to polymer, to MOF: mapping the coordination chemistry of CdIIusing113Cd solid-state NMR
Authors: Frost Jamie M. , Kobera Libor , Pialat Amélie , Zhang Yixin , Southern Scott A. , Gabidullin Bulat , Bryce David L. , Murugesu Muralee
Published: August 2016

Studies of three related CdIIsystems derived from the ligand 2,4,6-tris(2-pyrimidyl)-1,3,5-triazine, reveal an exceptionally rare example of113Cd–113CdJcoupling that is detectable by solid-state NMR (2JCd–Cd= ∼65 Hz).
Highly enantioselective construction of carbazole derivatives via [4+2] cycloaddition of silyloxyvinylindoles and β,γ-unsaturated α-ketoesters
Authors: Zhao Xiaohu , Mei Hongjiang , Xiong Qian , Fu Kai , Lin Lili , Liu Xiaohua , Feng Xiaoming
Published: August 2016

A highly enantioselective [4+2] cycloaddition between silyloxyvinylindoles and β,γ-unsaturated α-ketoesters was realized by an avaliable chiral N,N′-dioxide/yttrium triflate complex.
Effects of the acceptor unit in dyes with acceptor–bridge–donor architecture on the electron photo-injection mechanism and aggregation in DSSCs
Authors: Zarate Ximena , Claveria-Cadiz Francisca , Arias-Olivares David , Rodriguez-Serrano Angela , Inostroza Natalia , Schott Eduardo
Published: August 2016

The photo-injection mechanism is influenced by the acceptor motif of dyes in dye-sensitized solar cells (DSSCs).
Hard magnetism in structurally engineered silica nanocomposite
Authors: Song Hyon-Min , Zink Jeffrey I.
Published: August 2016

Architectural engineering of silica nanocomposites with structural intricacy and desirable hard magnetism is achieved by rapid thermal process.
Exploring the reaction pathways of Pd(ii)-catalyzed cyclohexene oxidation with molecular oxygen: vinylic and allylic oxidation, disproportionation and oxidative dehydrogenation
Authors: da Silva M. J. , Berlini L.
Published: August 2016

Palladium(ii) salts are able catalysts to promote different oxidative transformations of cyclohexene in the presence of molecular oxygen: vinylic and allylic oxidation and disproportionation.
Three-dimensional MgSiO3-coated SnO2/C nanostructures for efficient adsorption of heavy metal ions from aqueous solution
Authors: Han Tianli , Zhang Xiaoman , Fu Xiangqian , Liu Jinyun
Published: August 2016

A hierarchical nanostructure consisting of a coral-like base and nanoflake coating exhibits high adsorption performance towards Pb(ii) and As(v).
Toughened redox-active hydrogel as flexible electrolyte and separator applying supercapacitors with superior performance
Authors: Feng Enke , Ma Guofu , Sun Kanjun , Yang Qian , Peng Hui , Lei Ziqiang
Published: August 2016

The as-fabricated supercapacitor with PVA–H2SO4–AQSS gel polymer under fold or in-series conditions exhibits superior electrochemical performance.
Folate-conjugated stealth archaeosomes for the targeted delivery of novel antitumoral peptides
Authors: Jiblaoui Ahmad , Barbeau Julie , Vivès Thomas , Cormier Patrick , Glippa Virginie , Cosson Bertrand , Benvegnu Thierry
Published: August 2016

In this work, novel archaeosomes based on Egg-PC and a mixture of PEGylated archaeal tetraether lipids were investigated as nanocarriers forin vitrodelivery of an original anticancer peptide.
Photoresponse properties based on CdS nanoparticles deposited on multi-walled carbon nanotubes
Authors: Hu Chenglong , Wang Yuan , Chen Shaoyun , Cheng Huan , Lin Mei , Zhang Yuanfang , He Dan , Liu Xueqing , Liu Jiyan
Published: August 2016

The deposition of CdS on MWCNT has been successfully achieved by an attaching noncovalent chemical approach. The PCE of CdS@MWCNT nanohybrids was found to be as high as 4.54%, contrasting sharply with the value (1.67%) of the pure CdS nanoparticles.
Advances in photocatalytic NOx abatement through the use of Fe2O3/TiO2 nanocomposites
Authors: Balbuena José , Carraro Giorgio , Cruz Manuel , Gasparotto Alberto , Maccato Chiara , Pastor Adrián , Sada Cinzia , Barreca Davide , Sánchez Luis
Published: August 2016

Supported Fe2O3/TiO2 nanocomposites were prepared for the first time by a plasma-assisted route and successfully tested in photocatalytic NOx abatement driven by solar illumination.
Iodine-catalyzed formation of substituted 2-aminobenzothiazole derivatives in PEG400
Authors: Dumonteil G. , Hiebel M.-A. , Scherrmann M.-C. , Berteina-Raboin S.
Published: August 2016

An iodine-catalyzed formation of substituted 2-aminobenzothiazole derivatives is herein described using hydrogen peroxide as an oxidant in PEG400.
GFI1 functions in transcriptional control and cell fate determination require SNAG domain methylation to recruit LSD1
Authors: Velinder Matthew , Singer Jason , Bareyan Diana , Meznarich Jessica , Tracy Christopher M. , Fulcher James M. , McClellan David , Lucente Helena , Franklin Sarah , Sharma Sunil , Engel Michael E.
Published: August 2016

Proper hematopoietic cell fate decisions require co-ordinated functions of transcription factors, their associated co-regulators, and histone-modifying enzymes. Growth factor independence 1 (GFI1) is a zinc finger transcriptional repressor and master regulator of normal and malignant hematopoiesis. While several GFI1-interacting proteins have been described, how GFI1 leverages these relationships to carry out transcriptional repression remains unclear. Here, we describe a functional axis involving GFI1, SMYD2, and LSD1 that is a critical contributor to GFI1-mediated transcriptional repression. SMYD2 methylates lysine-8 (K8) within a -8KSKK11- motif embedded in the GFI1 SNAG domain. Methylation-defective GFI1 SNAG domain lacks repressor function due to failure of LSD1 recruitment and persistence of promoter H3K4 di-methyl marks. Methylation-defective GFI1 also fails to complement GFI1 depletion phenotypes in developing zebrafish and lacks pro-growth and survival functions in lymphoid leukemia cells. Our data show a discrete methylation event in the GFI1 SNAG domain that facilitates recruitment of LSD1 to enable transcriptional repression and co-ordinate control of hematopoietic cell fate in both normal and malignant settings.
Bad faith in All’s Well That Ends Well
Authors: Hadfield Andrew
Published: August 2016

All’s Well That Ends Wellis a complicated and disturbing play that has a comic ending, but which seems anything but a comedy with a forced marriage based on bed-trickery between the reluctant Bertram and the feisty and witty Helena. Unsurprisingly, audiences have tended to side with Helena and the play has been classified as a “problem comedy” ever since William Lawrence identified this particular group of Shakespeare plays nearly a century ago. I want to argue in this essay that the play might better be classified as an “equivocation” play alongsideMacbeth, Othello, andTroilus and Cressidaand that the anxieties about fidelity, honesty and truthfulness in marriage need to be read in terms of the fear of religious tolerance/intolerance which dominated religious politics in the early years of James’s reign before the passing of the Oath of Allegiance (1606). The play is notable for its interest in chop logic, which the clown in particular displays throughout the play, a counterpoint to the arguments of Bertram and Helena who want very different things, but who are bound together as future husband and wife. Although the language of treason and treachery is used throughout, the play is less interested in answering the question of how far one can trust a stranger within than the issue of how far one can accommodate the needs of others. This article is published as part of a collection to commemorate the 400th anniversary of William Shakespeare’s death.
A dissolution-precipitation mechanism is at the origin of concrete creep in moist environments
Authors: Pignatelli Isabella , Kumar Aditya , Alizadeh Rouhollah , Le Pape Yann , Bauchy Mathieu , Sant Gaurav
Published: August 2016

Long-term creep (i.e., deformation under sustained load) is a significant material response that needs to be accounted for in concrete structural design. However, the nature and origin of concrete creep remain poorly understood and controversial. Here, we propose that concrete creep at relative humidity ≥ 50%, but fixed moisture content (i.e., basic creep), arises from a dissolution-precipitation mechanism, active at nanoscale grain contacts, as has been extensively observed in a geological context, e.g., when rocks are exposed to sustained loads, in liquid-bearing environments. Based on micro-indentation and vertical scanning interferometry data and molecular dynamics simulations carried out on calcium–silicate–hydrate (C–S–H), the major binding phase in concrete, of different compositions, we show that creep rates are correlated with dissolution rates—an observation which suggests a dissolution-precipitation mechanism as being at the origin of concrete creep. C–S–H compositions featuring high resistance to dissolution, and, hence, creep are identified. Analyses of the atomic networks of such C–S–H compositions using topological constraint theory indicate that these compositions present limited relaxation modes on account of their optimally connected (i.e., constrained) atomic networks.
Fluid mobility over corrugated surfaces in the Stokes regime
Authors: Shelley S. R. , Smith J. D. , Hibbins A. P. , Sambles J. R. , Horsley S. A. R.
Published: August 2016

An exact solution is found for laminar fluid flow along the grooves of a family of surfaces whose shape is given by the Lambert W-function. This simple solution allows for the slip length in the direction parallel to the grooves to be calculated exactly. With this analytical model, we establish the regime of validity for a previously untested perturbation theory intended for calculating the surface mobility tensor of arbitrary periodic surfaces, finding that it compares well to the exact expression for nearly all choices of parameters of the conformal map. To test this perturbation theory further, the mobility tensor is evaluated for a simple sinusoidal surface for flow both parallel and perpendicular to the grooves, finding that the perturbation theory is less accurate in the latter of these two cases.
Experimental evaluation of the response of micro-channel plate detector to ions with 10s of MeV energies
Authors: Jeong Tae Won , Singh P. K. , Scullion C. , Ahmed H. , Kakolee K. F. , Hadjisolomou P. , Alejo A. , Kar S. , Borghesi M. , Ter-Avetisyan S.
Published: August 2016

The absolute calibration of a microchannel plate (MCP) assembly using a Thomson spectrometer for laser-driven ion beams is described. In order to obtain the response of the whole detection system to the particles’ impact, a slotted solid state nuclear track detector (CR-39) was installed in front of the MCP to record the ions simultaneously on both detectors. The response of the MCP (counts/particles) was measured for 5–58 MeV carbon ions and for protons in the energy range 2–17.3 MeV. The response of the MCP detector is non-trivial when the stopping range of particles becomes larger than the thickness of the detector. Protons with energies E ≳ 10 MeV are energetic enough that they can pass through the MCP detector. Quantitative analysis of the pits formed in CR-39 and the signal generated in the MCP allowed to determine the MCP response to particles in this energy range. Moreover, a theoretical model allows to predict the response of MCP at even higher proton energies. This suggests that in this regime the MCP response is a slowly decreasing function of energy, consistently with the decrease of the deposited energy. These calibration data will enable particle spectra to be obtained in absolute terms over a broad energy range.
Stability of thermal convection in a rotating cylindrical container
Authors: Herrada Miguel , Shtern Vladimir
Published: August 2016

The rotation and an axial gradient of temperature drive the meridional circulation of a fluid filling a sealed cylindrical container. This numerical study explains why the flow remains stable up to the Grashof number Gr around 1011; Gr characterizes the circulation strength. The shear-layer instability, occurring in a rotating pipe for small values of the Prandtl number Pr [M. A. Herrada and V. N. Shtern, “Stability of centrifugal convection in a rotating pipe,” Phys. Fluids 27, 064106 (2015)], is suppressed here even for the cylinder length-to-radius ratio being ten. The cold end disk enhances the fluid circulation near the sidewall and diminishes it near the axis. The inflection point in the radial profile of axial velocity shifts to the sidewall vicinity where the stable centrifugal stratification and the no-slip condition prevent the disturbance growth. The cases Pr = 0, 0.015 (mercury), 0.7 (air), and 5.8 (water) are particularly analyzed. At Pr > 0, the stable density stratification develops and helps to suppress the disturbances. The obtained results are of fundamental interest and might be important for the development of efficient heat exchangers.
All-dielectric phase-change reconfigurable metasurface
Authors: Karvounis Artemios , Gholipour Behrad , MacDonald Kevin F. , Zheludev Nikolay I.
Published: August 2016

We harness non-volatile, amorphous-crystalline transitions in the chalcogenide phase-change medium germanium antimony telluride (GST) to realize optically-switchable, all-dielectric metamaterials. Nanostructured, subwavelength-thickness films of GST present high-quality resonances that are spectrally shifted by laser-induced structural transitions, providing reflectivity and transmission switching contrast ratios of up to 5:1 (7 dB) at visible/near-infrared wavelengths selected by design.
Laser induced fluorescence measurements of axial velocity, velocity shear, and parallel ion temperature profiles during the route to plasma turbulence in a linear magnetized plasma device
Authors: Chakraborty Thakur S. , Adriany K. , Gosselin J. J. , McKee J. , Scime E. E. , Sears S. H. , Tynan G. R.
Published: August 2016

We report experimental measurements of the axial plasma flow and the parallel ion temperature in a magnetized linear plasma device. We used laser induced fluorescence to measure Doppler resolved ion velocity distribution functions in argon plasma to obtain spatially resolved axial velocities and parallel ion temperatures. We also show changes in the parallel velocity profiles during the transition from resistive drift wave dominated plasma to a state of weak turbulence driven by multiple plasma instabilities.
Fragmentation pathways of tungsten hexacarbonyl clusters upon electron ionization
Authors: Neustetter M. , Jabbour Al Maalouf E. , Limão-Vieira P. , Denifl S.
Published: August 2016

Electron ionization of neat tungsten hexacarbonyl (W(CO)6) clusters has been investigated in a crossed electron-molecular beam experiment coupled with a mass spectrometer system. The molecule is used for nanofabrication processes through electron beam induced deposition and ion beam induced deposition techniques. Positive ion mass spectra of W(CO)6 clusters formed by electron ionization at 70 eV contain the ion series of the type W(CO)n+ (0 ≤ n ≤ 6) and W2(CO)n+ (0 ≤ n ≤ 12). In addition, a series of peaks are observed and have been assigned to WC(CO)n+ (0 ≤ n ≤ 3) and W2C(CO)n+ (0 ≤ n ≤ 10). A distinct change of relative fragment ion intensity can be observed for clusters compared to the single molecule. The characteristic fragmentation pattern obtained in the mass spectra can be explained by a sequential decay of the ionized organometallic, which is also supported by the study of the clusters when embedded in helium nanodroplets. In addition, appearance energies for the dissociative ionization channels for singly charged ions have been estimated from experimental ion efficiency curves.
A theoretical study of the relaxation of a phenyl group chemisorbed to an RDX freestanding thin film
Authors: Pereverzev Andrey , Sewell Thomas D.
Published: August 2016

Energy relaxation from an excited phenyl group chemisorbed to the surface of a crystalline thin film of α-1,3,5-trinitro-1,3,5-triazacyclohexane (α-RDX) at 298 K and 1 atm is simulated using molecular dynamics. Two schemes are used to excite the phenyl group. In the first scheme, the excitation energy is added instantaneously as kinetic energy by rescaling momenta of the 11 atoms in the phenyl group. In the second scheme, the phenyl group is equilibrated at a higher temperature in the presence of static RDX geometries representative of the 298 K thin film. An analytical model based on ballistic phonon transport that requires only the harmonic part of the total Hamiltonian and includes no adjustable parameters is shown to predict, essentially quantitatively, the short-time dynamics of the kinetic energy relaxation (∼200 fs). The dynamics of the phenyl group for times longer than about 6 ps follows exponential decay and agrees qualitatively with the dynamics described by a master equation. Long-time heat propagation within the bulk of the crystal film is consistent with the heat equation.
Stability of stratified two-phase flows in inclined channels
Authors: Barmak I. , Gelfgat A. Yu. , Ullmann A. , Brauner N.
Published: August 2016

Linear stability of the stratified gas-liquid and liquid-liquid plane-parallel flows in the inclined channels is studied with respect to all wavenumber perturbations. The main objective is to predict the parameter regions in which the stable stratified configuration in inclined channels exists. Up to three distinct base states with different holdups exist in the inclined flows, so that the stability analysis has to be carried out for each branch separately. Special attention is paid to the multiple solution regions to reveal the feasibility of the non-unique stable stratified configurations in inclined channels. The stability boundaries of each branch of the steady state solutions are presented on the flow pattern map and are accompanied by the critical wavenumbers and the spatial profiles of the most unstable perturbations. Instabilities of different nature are visualized by the streamlines of the neutrally stable perturbed flows, consisting of the critical perturbation superimposed on the base flow. The present analysis confirms the existence of two stable stratified flow configurations in a region of low flow rates in the countercurrent liquid-liquid flows. These configurations become unstable with respect to the shear mode of instability. It was revealed that in slightly upward inclined flows the lower and middle solutions for the holdup are stable in the part of the triple solution region, while the upper solution is always unstable. In the case of downward flows, in the triple solution region, none of the solutions are stable with respect to the short-wave perturbations. These flows are stable only in the single solution region at low flow rates of the heavy phase, and the long-wave perturbations are the most unstable ones.
Ultra-fast computation of electronic spectra for large systems by tight-binding based simplified Tamm-Dancoff approximation (sTDA-xTB)
Authors: Grimme Stefan , Bannwarth Christoph
Published: August 2016

The computational bottleneck of the extremely fast simplified Tamm-Dancoff approximated (sTDA) time-dependent density functional theory procedure [S. Grimme, J. Chem. Phys. 138, 244104 (2013)] for the computation of electronic spectra for large systems is the determination of the ground state Kohn-Sham orbitals and eigenvalues. This limits such treatments to single structures with a few hundred atoms and hence, e.g., sampling along molecular dynamics trajectories for flexible systems or the calculation of chromophore aggregates is often not possible. The aim of this work is to solve this problem by a specifically designed semi-empirical tight binding (TB) procedure similar to the well established self-consistent-charge density functional TB scheme. The new special purpose method provides orbitals and orbital energies of hybrid density functional character for a subsequent and basically unmodified sTDA procedure. Compared to many previous semi-empirical excited state methods, an advantage of the ansatz is that a general eigenvalue problem in a non-orthogonal, extended atomic orbital basis is solved and therefore correct occupied/virtual orbital energy splittings as well as Rydberg levels are obtained. A key idea for the success of the new model is that the determination of atomic charges (describing an effective electron-electron interaction) and the one-particle spectrum is decoupled and treated by two differently parametrized Hamiltonians/basis sets. The three-diagonalization-step composite procedure can routinely compute broad range electronic spectra (0-8 eV) within minutes of computation time for systems composed of 500-1000 atoms with an accuracy typical of standard time-dependent density functional theory (0.3-0.5 eV average error). An easily extendable parametrization based on coupled-cluster and density functional computed reference data for the elements H–Zn including transition metals is described. The accuracy of the method termed sTDA-xTB is first benchmarked for vertical excitation energies of open- and closed-shell systems in comparison to other semi-empirical methods and applied to exemplary problems in electronic spectroscopy. As side products of the development, a robust and efficient valence electron TB method for the accurate determination of atomic charges as well as a more accurate calculation scheme of dipole rotatory strengths within the Tamm-Dancoff approximation is proposed.
Complete equation of state for shocked liquid nitrogen: Analytical developments
Authors: Winey J. M. , Gupta Y. M.
Published: August 2016

The thermodynamic response of liquid nitrogen has been studied extensively, in part, due to the long-standing interest in the high pressure and high temperature dissociation of shocked molecular nitrogen. Previous equation of state (EOS) developments regarding shocked liquid nitrogen have focused mainly on the use of intermolecular pair potentials in atomistic calculations. Here, we present EOS developments for liquid nitrogen, incorporating analytical models, for use in continuum calculations of the shock compression response. The analytical models, together with available Hugoniot data, were used to extrapolate a low pressure reference EOS for molecular nitrogen [R. Span et al., J. Phys. Chem. Ref. Data 29, 1361 (2000)] to high pressures and high temperatures. Using the EOS presented here, the calculated pressures and temperatures for single shock, double shock, and multiple shock compression of liquid nitrogen provide a good match to the measured results over a broad range of P-T space. These calculations provide the first comparison of EOS developments with recently measured P-T states under multiple shock compression. The present EOS developments are general and are expected to be useful for other liquids that have low pressure reference EOS information available.
The adiabatic limit of the exact factorization of the electron-nuclear wave function
Authors: Eich F. G. , Agostini Federica
Published: August 2016

We propose a procedure to analyze the relation between the exact factorization of the electron-nuclear wave function and the Born-Oppenheimer approximation. We define the adiabatic limit as the limit of infinite nuclear mass. To this end, we introduce a unit system that singles out the dependence on the electron-nuclear mass ratio of each term appearing in the equations of the exact factorization. We observe how non-adiabatic effects induced by the coupling to the nuclear motion affect electronic properties and we analyze the leading term, connecting it to the classical nuclear momentum. Its dependence on the mass ratio is tested numerically on a model of proton-coupled electron transfer in different non-adiabatic regimes.
A novel optical apparatus for the study of rolling contact wear/fatigue based on a high-speed camera and multiple-source laser illumination
Authors: Bodini I. , Sansoni G. , Lancini M. , Pasinetti S. , Docchio F.
Published: August 2016

Rolling contact wear/fatigue tests on wheel/rail specimens are important to produce wheels and rails of new materials for improved lifetime and performance, which are able to operate in harsh environments and at high rolling speeds. This paper presents a novel non-invasive, all-optical system, based on a high-speed video camera and multiple laser illumination sources, which is able to continuously monitor the dynamics of the specimens used to test wheel and rail materials, in a laboratory test bench. 3D macro-topography and angular position of the specimen are simultaneously performed, together with the acquisition of surface micro-topography, at speeds up to 500 rpm, making use of a fast camera and image processing algorithms. Synthetic indexes for surface micro-topography classification are defined, the 3D macro-topography is measured with a standard uncertainty down to 0.019 mm, and the angular position is measured on a purposely developed analog encoder with a standard uncertainty of 2.9°. The very small camera exposure time enables to obtain blur-free images with excellent definition. The system will be described with the aid of end-cycle specimens, as well as of in-test specimens.
Experimental evidence of beam-foil plasma creation during ion-solid interaction
Authors: Sharma Prashant , Nandi Tapan
Published: August 2016

Charge state evolution of the energetic projectile ions during the passage through thin carbon foils has been revisited using the X-ray spectroscopy technique. Contributions from the bulk and the solid surface in the charge changing processes have been segregated by measuring the charge state distribution of the projectile ions in the bulk of the target during the ion–solid interaction. Interestingly, the charge state distribution measured in the bulk exhibits Lorentzian profile in contrast to the well-known Gaussian structure observed using the electromagnetic methods and the theoretical predictions. The occurrence of such behavior is a direct consequence of the imbalance between charge changing processes, which has been seen in various cases of the laboratory plasma. It suggests that the ion-solid collisions constitute high-density, localized plasma in the bulk of the solid target, called the beam-foil plasma. This condensed beam-foil plasma is similar to the high-density solar and stellar plasma which may have practical implementations in various fields, in particular, plasma physics and nuclear astrophysics. The present work suggests further modification in the theoretical charge state distribution calculations by incorporating the plasma coupling effects during the ion–solid interactions. Moreover, the multi-electron capture from the target exit surface has been confirmed through comparison between experimentally measured and theoretically predicted values of the mean charge state of the projectile ions.
Dual wavelength imaging of a scrape-off layer in an advanced beam-driven field-reversed configuration
Authors: Osin D. , Schindler T.
Published: August 2016

A dual wavelength imaging system has been developed and installed on C-2U to capture 2D images of a He jet in the Scrape-Off Layer (SOL) of an advanced beam-driven Field-Reversed Configuration (FRC) plasma. The system was designed to optically split two identical images and pass them through 1 nm FWHM filters. Dual wavelength images are focused adjacent on a large format CCD chip and recorded simultaneously with a time resolution down to 10 μs using a gated micro-channel plate. The relatively compact optical system images a 10 cm plasma region with a spatial resolution of 0.2 cm and can be used in a harsh environment with high electro-magnetic noise and high magnetic field. The dual wavelength imaging system provides 2D images of either electron density or temperature by observing spectral line pairs emitted by He jet atoms in the SOL. A large field of view, combined with good space and time resolution of the imaging system, allows visualization of macro-flows in the SOL. First 2D images of the electron density and temperature observed in the SOL of the C-2U FRC are presented.
Monolithic integration of enhancement-mode vertical driving transistorson a standard InGaN/GaN light emitting diode structure
Authors: Lu Xing , Liu Chao , Jiang Huaxing , Zou Xinbo , Zhang Anping , Lau Kei May
Published: August 2016

In this letter, monolithic integration of InGaN/GaN light emitting diodes (LEDs) with vertical metal-oxide-semiconductor field effect transistor (VMOSFET) drivers have been proposed and demonstrated. The VMOSFET was achieved by simply regrowing a p- and n-GaN bilayer on top of a standard LED structure. After fabrication, the VMOSFET is connected with the LED through the conductive n-GaN layer, with no need of extra metal interconnections. The junction-based VMOSFET is inherently an enhancement-mode (E-mode) device with a threshold voltage of 1.6 V. By controlling the gate bias of the VMOSFET, the light intensity emitted from the integrated VMOSFET-LED device could be well modulated, which shows great potential for various applications, including solid-state lighting, micro-displays, and visible light communications.
Designing convex repulsive pair potentials that favor assembly of kagome and snub square lattices
Authors: Piñeros William D. , Baldea Michael , Truskett Thomas M.
Published: August 2016

Building on a recently introduced inverse strategy, isotropic and convex repulsive pair potentials were designed that favor assembly of particles into kagome and equilateral snub square lattices. The former interactions were obtained by a numerical solution of a variational problem that maximizes the range of density for which the ground state of the potential is the kagome lattice. Similar optimizations targeting the snub square lattice were also carried out, employing a constraint that required a minimum chemical potential advantage of the target over select competing structures. This constraint helped to discover isotropic interactions that meaningfully favored the snub square lattice as the ground state structure despite the asymmetric spatial distribution of particles in its coordination shells and the presence of tightly competing structures. Consistent with earlier published results [W. Piñeros et al., J. Chem. Phys. 144, 084502 (2016)], enforcement of greater chemical potential advantages for the target lattice in the interaction optimization led to assemblies with enhanced thermal stability.