bluuebunny/crossref_metadata_2025 huggingface dataset:
Endoplasmic reticulum stress and cell death in mTORC1‐overactive cells is induced by nelfinavir and enhanced by chloroquine
Authors: Johnson Charlotte E. , Hunt David K. , Wiltshire Marie , Herbert Terry P. , Sampson Julian R. , Errington Rachel J. , Davies D. Mark , Tee Andrew R.
Published: November 2014

Inappropriate activation of mammalian/mechanistic target of rapamycin complex 1 (mTORC1) is common in cancer and has many cellular consequences including elevated endoplasmic reticulum (ER) stress. Cells employ autophagy as a critical compensatory survival mechanism during ER stress. This study utilised drug‐induced ER stress through nelfinavir in order to examine ER stress tolerance in cell lines with hyper‐active mTORC1 signalling. Our initial findings in wild type cells showed nelfinavir inhibited mTORC1 signalling and upregulated autophagy, as determined by decreased rpS6 and S6K1 phosphorylation, and SQTSM1 protein expression, respectively. Contrastingly, cells with hyper‐active mTORC1 displayed basally elevated levels of ER stress which was greatly exaggerated following nelfinavir treatment, seen through increased CHOP mRNA and XBP1 splicing. To further enhance the effects of nelfinavir, we introduced chloroquine as an autophagy inhibitor. Combination of nelfinavir and chloroquine significantly increased ER stress and caused selective cell death in multiple cell line models with hyper‐active mTORC1, whilst control cells with normalised mTORC1 signalling tolerated treatment. By comparing chloroquine to other autophagy inhibitors, we uncovered that selective toxicity invoked by chloroquine was independent of autophagy inhibition yet entrapment of chloroquine to acidified lysosomal/endosomal compartments was necessary for cytotoxicity. Our research demonstrates that combination of nelfinavir and chloroquine has therapeutic potential for treatment of mTORC1‐driven tumours.
Implication of Boron Isotope Geochemistry for the Pedogenic Environments in Loess and Paleosol Sequences of Central China
Authors: Wei Hai-Zhen , Lei Fang , Jiang Shao-Yong , Lu Hua-Yu , Xiao Ying-Kai , Zhang Han-Zhi , Sun Xue-Feng
Published: November 2014

We investigated the boron isotopic composition in loess–paleosol sequences in five different profiles in the Chinese Loess Plateau. Three possible boron sources are identified: atmospheric input, carbonates, and weathered silicate rocks. Variations of [Sr], [B], δ11B and the magnetic susceptibility correlate well with the pedogenetic intensity in three out of the five studied profiles, where pedogenesis under a cold–dry climate indicates lower δ11B, lower [B], lower magnetic susceptibility and higher [Sr] values. Exceptions to the variations between the δ11B and other known proxies were observed in arenaceous soils and the Red Clay sequence: the former suggested that vertical redistribution probably occurred with the boron migration, and the latter indicated an unknown mechanism of susceptibility enhancement. A better correlation between the δ11B and magnetic susceptibility and the quantitative estimation of boron budget from each source confirms the influence of paleoenvironmental changes on boron geochemical cycle. Significant positive correlations in Sr/Ca vs. B/Ca and Mg/Ca vs. B/Ca reflect consistent enrichment behavior of those mobile elements into calcium carbonate. The preliminary results imply that boron isotopic compositions in soils can be a potential geochemical proxy to reconstruct the paleoenvironmental changes in loess–paleosol sequences.
Treatment of early episode in patients with schizophrenia: the role of long acting antipsychotics
Authors: Heres S. , Lambert M. , Vauth R.
Published: November 2014

The use of long-acting injectable antipsychotics (LAIs) in schizophrenia is usually restricted to patients in long-term treatment, who prefer them to oral antipsychotics, and to patients with multiple relapses who have a history of non-adherence. However, preliminary evidence from patients in the early phases of the disease suggest that second generation LAIs may be superior to second generation oral medications with regard to the control of negative symptoms and psychosocial functioning. Moreover, several studies have found that psychiatrists are generally reluctant to prescribe LAI antipsychotics and under-estimate their acceptability by patients. Key elements to take into account when offering a LAI in the early course of schizophrenia should include their potential superiority in allowing early detection of non-adherence and in reducing the number of rehospitalisations and relapses.
Scenario 1: multiple casualties following a parachute insertion
Authors: CONRAD LILY
Published: November 2014

Twelve-person Special Forces team Interdiction operation for weapons convoy Night static line jump from C-130 Four-mile patrol over rocky terrain to objective Planned helicopter extraction near target Observed during parachute drop and taken under fire First casualty: head wound, unconscious Second casualty: chest wound, severe repsiratory distress develops in several minutes Third casualty: multiple abdominal wounds
Scenario 3: unconscious parachute jumper fouled in a tree
Authors: HORNER BRIAN
Published: November 2014

Twelve-person Special Forces team Assault on jungle narcotics processing laboratory Night static-line jump from C-130 Four-mile patrol to objective Planned extraction by helicopter 2 miles from target On drop-zone, one jumper observed to be unconscious and caught in tree about 30 ft off the ground
Scenario 4: near-drowning after a water parachute jump
Authors: DICKISON ANNE
Published: November 2014

Seven-person SEAL team Night high-altitude high-opening (HAHO) water jump Planned assault operation on a terrorist group in house near beach One SEAL becomes tangled in his lines after landing Rescued by swim buddy Casualty unconscious and in respiratory distress on beach
Scenario 5: multiple trauma from parachute collapse
Authors: WEISS ERIC
Published: November 2014

Twelve-person Special Forces Team Interdiction operation on a weapons convoy Night static line jump from C-130 Four-mile patrol over rocky terrain to objective Planned helicopter extraction near target One jumper has canopy collapse 40 ft above the drop zone Open facial fractures with blood and teeth in the oropharynx Bilateral ankle fractures Open angulated fracture of the left femur
Scenario 8: acute gastroenteritis on a 4-day patrol
Authors: BACKER HOWARD
Published: November 2014

Twelve-person Special Forces team Dropped into unfriendly Middle Eastern country Four-day SCUD missile hunt Planned helicopter extraction at end of operation Lost communications; no CASEVAC or extraction plan changes possible Patrolling in moderately populated area Two patrol members develop severe diarrhea and stomach cramps
Scenario 9: altitude sickness
Authors: ZAFREN KEN
Published: November 2014

Twelve-person Special Forces team Acclimated to 4500 ft altitude Intelligence-gathering patrol in mountainous region Helicopter insertion at 9000 ft Patrol over 8 hours to elevation of 14000 ft Establish observation post Several patrol members develop moderate fatigue and headaches One patrol member develops progressive cough and dyspnea
Scenario 10: cold water immersion
Authors: BAGIAN JAMES
Published: November 2014

Twenty-person Ranger patrol in Arctic terrain Cross-country skis traversing a frozen lake Planned direct action mission on radar site Moderate-intensity hostile patrol activity Air temperature 25°F Three-mile patrol to target Planned extraction at objective area by helicopter One patrol member suddenly falls through the ice into the water
Scenario 11: open fracture of the tibia and fibula from fast roping
Authors: GLANCY GERALD
Published: November 2014

Twelve-person Special Forces team Planned assault on terrorist training camp Rappel into jungle clearing as helicopter unable to land Four-mile patrol to target Planned extraction site 1 mile from target Fourth man down lands hard Open fracture of left tibia and fibula
Strategic Institutional Design: Two Case Studies of Non-Majoritarian Agencies in Health Care Priority-Setting
Authors: Landwehr Claudia , Böhm Katharina
Published: November 2014

Governments’ decisions to delegate policy decisions to non-majoritarian agencies have been both criticized as attempts at blame avoidance or depoliticization and defended as enhancing the rationality and credibility of decisions. This article focuses not on the decision to delegate, but on the decisions of how and to whom to delegate. We argue that strategic motives are relevant not only in the decision to delegate, but equally, and perhaps more importantly, in the selection of the institutional properties of these non-majoritarian agencies. We present two case studies of health care priority-setting, in England and Germany, to illustrate how governments proceed strategically in institutional design choices and how their decisions affect outcomes.
Verification of the Spectral Classification of Stars Using the Hipparcos Catalogue
Authors: Deb D. , Chakraborty P.
Published: November 2014

The spectral classifications of the stars from spectral data have been corrected from time to time and new spectral and luminosity classes have been assigned. Identifying stars with wrong spectral and luminosity classification has been a stupendous task from the huge catalogue of stars. In this work we describe a simple statistical technique to identify stars with wrong spectral and luminosity classification. We make use of the Hipparcos catalogue which has the most accurate measurement of the distance d of the stars. A comparison is made between the absolute V magnitudes MV computed using the observed V magnitude mV and d, with the standard absolute magnitude MV0 assigned to a spectral and luminosity classification for a large number of stars (with d < 100 pc). As expected, for most of the stars the difference between MV and MV0 lies within the range ±2 mag, due to the intrinsic nature of each star ignored in this generalisation. A systematic error analysis is made of all the observable used in the computation. Therefore to identify stars which we suspect to be wrongly classified, we look for abnormal deviation in |MV – MV0| ≥5. The location of these stars with respect to the galactic plain and interstellar extinction is also investigated to rule out effects due to variations in the interstellar extinction. From our results we see that some of the stars were indeed wrongly classified and have recently been reclassified (SIMBAD). The reclassification drastically reduces the |MV – MV0| deviation. The other stars in the list which have not yet been reclassified need to be spectroscopically investigated and classified again.
Transition – Wie Jugendliche mit Cystischer Fibrose und ihre Eltern den Übertritt von der Kinder- in die Erwachsenenmedizin erleben
Authors: Becher Christine , Regamey Nicolas , Spichiger Elisabeth
Published: November 2014

Hintergrund: Cystische Fibrose (CF) ist die häufigste autosomal-rezessiv vererbte Erkrankung in der europäischen Bevölkerung. Die mittlere Überlebenszeit von CF-Betroffenen steigt und liegt heute bei über 40 Jahren. Deshalb ist die Betreuung in der Adoleszenz während des Übergangs von der Pädiatrie in die Erwachsenenmedizin, in der Fachsprache Transition genannt, ein wichtiges Thema. Ziel: Mit dieser Studie wurde exploriert, wie Jugendliche mit CF und ihre Eltern die Transition erlebten. Methode: Die Studie wurde an einem universitären CF Zentrum durchgeführt. Sechs Jugendliche und ihre Mütter erzählten in zwölf Interviews, wie sie die Phase der Transition erlebten. Die Auswertung der transkribierten Interviews erfolgte nach der Methode der hermeneutischen Phänomenologie. Ergebnisse: Positive und negative Erfahrungen während der langjährigen Behandlung in der Kinderklinik, die Adoleszenz als Lebensphase und die Zusammenarbeit mit den Ärzten während der Transition beeinflussten das Erleben der Betroffenen. Für die Mütter könnte eine unsensible Eröffnung der CF Diagnose Auswirkungen auf die Transition gehabt haben. Die Jugendlichen begrüßten eine individualisierte, ihrer Entwicklung angepasste Begleitung. Kontinuität in der ärztlichen Betreuung, die Ankündigung des Übertritts und der Einbezug in dessen Planung erleichterten die Transition. Besonders geschätzt wurde die zeitliche Anpassung an individuelle Bedürfnisse. Schlussfolgerung: Flexibilität und die enge Zusammenarbeit zwischen dem pädiatrischen und adulten CF-Team sind zentral für die Betreuung der Familien.
Lebensqualität und Gesundheit – Subjektive Perspektiven von selbstauskunftsfähigen Pflegeheimbewohnern – eine qualitative Studie
Authors: Behr Anja , Meyer Roger , Holzhausen Martin , Kuhlmey Adelheid , Schenk Liane
Published: November 2014

Hintergrund: Ein Ziel von Forschung und Pflegepraxis ist die Aufrechterhaltung der Lebensqualität von Bewohner(inne)n stationärer Langzeitpflegeeinrichtungen. Gesundheit, als ein wichtiger Teilbereich von Lebensqualität, gewinnt mit steigendem Alter an Bedeutung. Ziel: Die vorliegende Arbeit verfolgt das Ziel, die Aspekte «Intakte geistige Fähigkeiten» und «Mobil sein» eingehender zu analysieren. Methode: Es wurden neun Männer und 33 Frauen aus acht verschiedenen Pflegeheimen in Berlin und Umland mittels narrativer Leitfadeninterviews befragt. Die selbstauskunftsfähigen Interviewpartner waren im direkten Gespräch durch die Interviewer gewonnen worden. Die Auswertung der Interviews erfolgte in Anlehnung an die dokumentarische Methode nach Bohnsack. Ergebnisse: Für die Befragten ist es wichtig, bis ins hohe Alter geistig leistungsfähig zu sein, um selbstbestimmt handeln, und eigenständig das Leben kontrollieren zu können. Als problematisch sehen die Befragten nicht nur den Verlust eigener, sondern auch den Verlust der kognitiven Fähigkeiten von Mitbewohnern an. Als eine weitere zentrale Komponente von Gesundheit wird die Fähigkeit des «Laufen Könnens» erachtet, um Selbstbestimmung zu wahren und an den Aktivitäten des (Heim-)Lebens teilzuhaben. Schlussfolgerungen: Pflegeheimbewohner(innen) sollten eine gezielte und individuelle Förderung kognitiver Fähigkeiten erhalten. Interessierte Bewohner(innen) sollten verstärkt Informationen zum Krankheitsbild der Demenz erhalten. Alltagsnahe Bewegungsangebote können zum Erhalt der Mobilität beitragen.
Wie Angehörige die pflegerische Betreuung von dialysepflichtigen Patientinnen und Patienten mit Demenz auf der Hämodialysestation erleben – Eine qualitative Studie
Authors: Rütti Gisela , Huynh-Do Uyen , Spichiger Elisabeth
Published: November 2014

Hintergrund: Bis zu 70 % der Dialysepatienten Sämtliche im Text verwendeten männlichen Formulierungen gelten auch für das weibliche Geschlecht. über 55 Jahre leiden an einer demenziellen Entwicklung. Einem gegebenenfalls agitierten Patienten mit Demenz kann es schwerfallen, sich während der Hämodialysetherapie ruhig zu halten, was zu einer herausfordernden Betreuung führt. Obwohl Angehörige von Menschen mit Demenz sowie von Hämodialysepatienten als Betreuungsexperten im Alltag beschrieben werden, wurde bisher die Perspektive der Angehörigen von Hämodialysepatienten mit Demenz nicht untersucht. Ziel: Diese qualitative Studie soll aufzeigen, wie diese Angehörigen die Pflege auf der Hämodialysestation erleben. Methode: Acht Interviews mit Angehörigen wurden auf zwei Hämodialysestationen erhoben und mittels Inhaltsanalyse ausgewertet. Ergebnisse: Angehörige wussten den Patienten bei den Pflegenden in guten Händen. Die Anwesenheit der Angehörigen während der Therapie war von unterschiedlicher Dauer und Häufigkeit; sie wurden selten in die Pflege einbezogen. Angehörige und Pflegende tauschten sich zum Befinden des Patienten kaum aus. Die Angehörigen beschrieben zwar demenzielle Symptome, aber es war ihnen wichtig zu bezeugen, dass der Patient noch «gut im Kopf» sei. Schlussfolgerungen: Angehörige von Menschen mit Demenz haben unterschiedliche Bedürfnisse bezüglich ihrer Anwesenheit während der Therapie und dem Informationsaustausch mit Fachpersonen. Pflegende sollten auf Angehörige zugehen und ihre individuellen Bedürfnisse erfassen, um eine gute Zusammenarbeit zu erreichen.
Beratungsqualität von Pflegeexpertinnen-APN im spitalexternen Bereich (APN-BQ) – Psychometrische Testung des Instruments
Authors: Petry Heidi , Suter-Riederer Susanne , Kerker-Specker Carmen , Imhof Lorenz
Published: November 2014

Hintergrund: Patientenzentrierte und individuell ausgerichtete Angebote, wie die häusliche Beratung durch Pflegeexpertinnen-APN (Advanced Practice Nurses), eignen sich besonders, chronisch kranke alte Menschen in einer möglichst selbstständigen Lebensführung zu unterstützen. Methode: Um die Qualität einer patientenzentrierten Beratung zu evaluieren, wurde ein 23-Item Instrument entwickelt und seine psychometrischen Eigenschaften mit einer Stichprobe von 206 Personen, die 80 Jahre und älter waren getestet. Ziel: Ziel dieses Artikels ist es, die Entwicklung und Evaluation des APN-BQ zu beschreiben. Die psychometrische Testung des Instruments erfolgte anhand einer Hauptkomponentenanalyse mit Varimax-Rotation. Ergebnisse: Die Analyse ergab eine stabile vier Faktorenstruktur (FS = 0,91) mit 19 Items. Alle Faktoren hatten eine Faktorladung > 0,45. Die interne Konsistenz der Gesamtskala ergab einen Wert von Cronbachs alpha 0,86. Die hohe Rücklaufquote der Fragebogen und die Tatsache, dass 98,8 % der Fragen beantwortet wurden, bestätigten die Anwendungsfreundlichkeit und Akzeptanz des Instruments. Schlussfolgerungen: Das APN-BQ erwies sich als zuverlässiges und in Bezug auf Inhalt und Konstrukt valides Instrument, die Struktur-, Prozess- und Ergebnisqualität einer patientenzentrierten Beratungsintervention in der gemeindenahen Versorgung sowie das Ausmaß der Partizipation und Selbstbefähigung (Empowerment) der zu Beratenden zu messen.
Nursing Minimum Data Sets (NMDS) – eine Literaturübersicht bezüglich Zielsetzungen und Datenelementen
Authors: Ranegger Renate , Ammenwerth Elske
Published: November 2014

Hintergrund: Um den prognostizierten Wandel im Pflegebereich begleiten zu können, wird seit langem die Forderung nach einer einheitlichen Datenbasis gestellt, auf deren Grundlage Pflegedaten von Leistungsanbietern transparent abgebildet werden können. In Österreich fehlt bis dato eine Empfehlung, welche Pflegedaten als «Basisdaten» dokumentiert werden müssen, wodurch eine nationale Vergleichbarkeit von Pflegedaten erschwert wird. Internationale Entwicklungen von Nursing Minimum Data Sets (NMDS) weisen darauf hin, dass Pflegedaten adäquat abgebildet werden können. Ziel der vorgestellten systematischen Literaturanalyse ist es, den aktuellen Wissensstand über NMDS zu erheben und eine strukturierte Beschreibung von NMDS zu entwickeln, welche vor allem die erfassten Datenelemente und die zugehörigen Zielsetzungen der NMDS-Verwendung dokumentieren kann. Ergebnisse: Insgesamt wurden 70 Publikationen zum Thema NMDS in die Literaturübersicht eingeschlossen. Die Analyse der vorgestellten acht NMDS ergab sechs zentrale Zielsetzungen und sechs übergeordnete Datenelemente. Zu den identifizierten sechs Zielsetzungen gehören: Beschreibung der Pflegepraxis, Verteilung finanzieller Mittel, Benchmarking, Personaleinsatzplanung, Trendanalysen und Qualitätssicherung. Die identifizierten sechs Datenelemente umfassen betriebliche Daten, demografische Daten, Pflegediagnosen, -interventionen, -ergebnisse (Qualitätsindikatoren) und Pflegeintensität (klinische Daten). Diskussion: Es hat sich gezeigt, dass kein klarer Zusammenhang zwischen den Zielsetzungen und Datenelementen der untersuchten minimalen Pflegedatensätzen vorliegt.
Emergency Department Admission and Mortality Rate for Suicidal Behavior
Authors: Pavarin Raimondo Maria , Fioritti Angelo , Fontana Francesca , Marani Silvia , Paparelli Alessandra , Boncompagni Giancarlo
Published: November 2014

Background: The international literature reports that for every completed suicide there are between 8 and 22 visits to an Emergency Department (ED) for attempted suicide/suicidal behavior. Aims: To describe the characteristics of admission to emergency departments (EDs) for suicide-related presenting complaints in the metropolitan area of Bologna; to estimate the risk for all-cause mortality and for suicide; to identify the profiles of subjects most at risk. Method: Follow-up of patients admitted to the EDs of the metropolitan area of Bologna between January 2004 and December 2010 for attempted suicide. A Cox model was used to evaluate the association between sociodemographic variables and the general mortality risk. Results: We identified 505 cases of attempted suicide, which were more frequent for female subjects, over the weekend, and at night (8:00 p.m./8:00 a.m.). The most used suicide methods were psychotropic drugs, sharp or blunt objects, and jumping from high places. In this cohort, 3.6% of subjects completed suicide (4.5% of males vs. 2.9% of females), 2.3% within 1 year of the start of follow-up. The most common causes of death were drug use and hanging. In the multivariate analysis, those who used illicit drugs 24 hr prior to admission to the ED (hazard ratio [HR] = 3.46, 95% CI = 1.23–9.73) and patients who refused the treatment (HR = 6.74, 95% CI = 1.86–24.40) showed an increased mortality risk for suicide. Conclusion: Deliberate self-harm patients presenting to the ED who refuse treatment represent a specific target group for setting up dedicated prevention schemes.
Effects of Rhodiola on production, health and gut development of broilers reared at high altitude in Tibet
Authors: Li Long , Wang Honghui , Zhao Xin
Published: November 2014

Rhodiola has long been used as a traditional medicine to increase resistance to physical stress in humans in Tibet. The current study was designed to investigate whether Rhodiola crenulata (R. crenulata) could alleviate the negative effects of hypoxia on broiler chickens reared in Tibet Plateau. The effect of supplementing crushed roots of R. crenulata on production performance, health and intestinal morphology in commercial male broilers was investigated. Dietary treatments included CTL (basal diet), Low-R (basal diet + 0.5% R. crenulata) and High-R (basal diet + 1.5% R. crenulata). In comparison with broilers fed the control diet, Low-R had no effect on production performance while High-R significantly decreased average daily feed intake at d14, 28 and 42, body weight at d28 and 42 and gut development. Ascites induced mortality did not differ among treatments. Nevertheless Low-R significantly reduced non-ascites induced mortality and total mortality compared with broilers fed CTL and High-R diets. Broilers fed the High-R diet had significantly increased blood red blood cell counts and hemoglobin levels at 28d compared with other treatments. Our results suggest that supplementation with Rhodiola might reduce the effects of hypoxia on broilers and consequently decrease mortality rate.
One-step ultrasonic synthesis of graphene quantum dots with high quantum yield and their application in sensing alkaline phosphatase
Authors: Zhu Yanhong , Wang Guangfeng , Jiang Hong , Chen Ling , Zhang Xiaojun
Published: November 2014

With only graphene oxide and KMnO4, the luminescent graphene quantum dots (GQDs) in high quantum yield were prepared by one-step synthesis using ultrasonication, and applied in the label-free, simple and fast fluorescence assay of alkaline phosphatase (ALP).
Cobalt-doped lithium-rich cathode with superior electrochemical performance for lithium-ion batteries
Authors: Yuan Bing , Liao Shi-Xuan , Xin Yan , Zhong Yanjun , Shi Xiaxing , Li Longyan , Guo Xiaodong
Published: November 2014

Cobalt doped to modify the structure of lithium-rich cathode and obtain the material with superior electrochemical performance.
An overview of protein moonlighting in bacterial infection
Authors: Henderson Brian
Published: November 2014

We are rapidly returning to a world in which bacterial infections are a major health issue. Pathogenic bacteria are able to colonize and cause pathology due to the possession of virulence factors such as adhesins, invasins, evasins and toxins. These are generally specifically evolved proteins with selective actions. It is, therefore, surprising that most human bacterial pathogens employ moonlighting proteins as virulence factors. Currently, >90 bacterial species employ one or more moonlighting protein families to aid colonization and induce disease. These organisms employ 90 moonlighting bacterial protein families and these include enzymes of the glycolytic pathway, tricarboxylic acid (TCA) cycle, hexosemonophosphate shunt, glyoxylate cycle and a range of other metabolic enzymes, proteases, transporters and, also, molecular chaperones and protein-folding catalysts. These proteins have homologues in eukaryotes and only a proportion of the moonlighting proteins employed are solely bacterial in origin. Bacterial moonlighting proteins can be divided into those with single moonlighting functions and those with multiple additional biological actions. These proteins contribute significantly to the population of virulence factors employed by bacteria and some are obvious therapeutic targets. Where examined, bacterial moonlighting proteins bind to target ligands with high affinity. A major puzzle is the evolutionary mechanism(s) responsible for bacterial protein moonlighting and a growing number of highly homologous bacterial moonlighting proteins exhibit widely different moonlighting actions, suggesting a lack in our understanding of the mechanism of evolution of protein active sites.
A frequency and amplitude scanned quadrupole mass filter for the analysis of high m/z ions
Authors: Shinholt Deven L. , Anthony Staci N. , Alexander Andrew W. , Draper Benjamin E. , Jarrold Martin F.
Published: November 2014

Quadrupole mass filters (QMFs) are usually not used to analyze high m/z ions, due to the low frequency resonant circuit that is required to drive them. Here we describe a new approach to generating waveforms for QMFs. Instead of scanning the amplitude of a sine wave to measure the m/z spectrum, the frequency of a trapezoidal wave is digitally scanned. A synchronous, narrow-range (<0.2%) amplitude scan overlays the frequency scan to improve the sampling resolution. Because the frequency is the primary quantity that is scanned, there is, in principle, no upper m/z limit. The frequency signal is constructed from a stabilized base clock using a field programmable gate array. This signal drives integrating amplifiers which generate the trapezoidal waves. For a trapezoidal wave the harmonics can be minimized by selecting the appropriate rise and fall times. To achieve a high resolving power, the digital signal has low jitter, and the trapezoidal waveform is generated with high fidelity. The QMF was characterized with cesium iodide clusters. Singly and multiply charged clusters with z up to +5 were observed. A resolving power of ∼1200 (FWHM) was demonstrated over a broad m/z range. Resolution was lost above 20 000 Th, partly because of congestion due to overlapping multiply charged clusters. Ions were observed for m/z values well in excess of 150 000 Th.
Survival probability for open spherical billiards
Authors: Dettmann Carl P. , Rahman Mohammed R.
Published: November 2014

We study the survival probability for long times in an open spherical billiard, extending previous work on the circular billiard. We provide details of calculations regarding two billiard configurations, specifically a sphere with a circular hole and a sphere with a square hole. The constant terms of the long-time survival probability expansions have been derived analytically. Terms that vanish in the long time limit are investigated analytically and numerically, leading to connections with the Riemann hypothesis.
Rate coefficients, binding probabilities, and related quantities for area reactivity models
Authors: Prüstel Thorsten , Meier-Schellersheim Martin
Published: November 2014

We further develop the general theory of the area reactivity model that describes the diffusion-influenced reaction of an isolated receptor-ligand pair in terms of a generalized Feynman-Kac equation and that provides an alternative to the classical contact reactivity model. Analyzing both the irreversible and reversible reaction, we derive the equation of motion of the survival probability as well as several relationships between single pair quantities and the reactive flux at the encounter distance. Building on these relationships, we derive the equation of motion of the many-particle survival probability for irreversible pseudo-first-order reactions. Moreover, we show that the usual definition of the rate coefficient as the reactive flux is deficient in the area reactivity model. Numerical tests for our findings are provided through Brownian Dynamics simulations. We calculate exact and approximate expressions for the irreversible rate coefficient and show that this quantity behaves differently from its classical counterpart. Furthermore, we derive approximate expressions for the binding probability as well as the average lifetime of the bound state and discuss on- and off-rates in this context. Throughout our approach, we point out similarities and differences between the area reactivity model and its classical counterpart, the contact reactivity model. The presented analysis and obtained results provide a theoretical framework that will facilitate the comparison of experiment and model predictions.
Reference Correlations of the Thermal Conductivity of o-Xylene, m-Xylene, p-Xylene, and Ethylbenzene from the Triple Point to 700 K and Moderate Pressures
Authors: Mylona S. K. , Antoniadis K. D. , Assael M. J. , Huber M. L. , Perkins R. A.
Published: November 2014

This paper contains new, representative reference equations for the thermal conductivity of o-xylene, m-xylene, p-xylene, and ethylbenzene. The equations are based in part upon a body of experimental data that has been critically assessed for internal consistency and for agreement with theory whenever possible. In the case of the dilute-gas thermal conductivity, a theoretically based correlation was adopted in order to extend the temperature range of the experimental data. Moreover, in the critical region, the experimentally observed enhancement of the thermal conductivity is well represented by theoretically based equations containing just one adjustable parameter. All four correlations are applicable for the temperature range from the triple point of each fluid to 700 K, and an upper pressure limit determined by the maximum density limit for the equation of state used to provide density. At the upper temperature limit of 700 K, the maximum pressure was 200 MPa for m-xylene and p-xylene, but 60 and 70 MPa for ethylbenzene and o-xylene, respectively. At lower temperatures, the maximum pressure is lower. The overall uncertainty (at the 95% confidence level) of the correlations of the thermal conductivity of o-, m-, p-xylene, and ethylbenzene, over their range of applicability, varies for each fluid. For o-xylene, we estimate the uncertainty for liquid and supercritical densities for temperatures from the triple point to 400 K to be 2.6%, and 4% at higher temperatures, and in the dilute-gas region we estimate the uncertainty to be 2%. For m-xylene, the estimated uncertainty for liquid and supercritical densities at temperatures from the triple point to 375 K is 3.6%, and 5% at higher temperatures, and 6% for the dilute gas. For p-xylene, the estimated uncertainty for liquid and supercritical densities at temperatures from the triple point to 700 K is 3.6%, and 2.5% for the dilute gas. Finally, for ethylbenzene the estimated uncertainty for liquid and supercritical densities at temperatures from the triple point to 400 K is 2.8%, and 2.5% in the dilute-gas region. Uncertainties in the critical region for all four fluids are much larger, since the thermal conductivity approaches infinity at the critical point and is very sensitive to small changes in density.
Instability of elliptic liquid jets: Temporal linear stability theory and experimental analysis
Authors: Amini Ghobad , Lv Yu , Dolatabadi Ali , Ihme Matthias
Published: November 2014

The instability dynamics of inviscid liquid jets issuing from elliptical orifices is studied, and effects of the surrounding gas and the liquid surface tension on the stability behavior are investigated. A dispersion relation for the zeroth azimuthal (axisymmetric) instability mode is derived. Consistency of the analysis is confirmed by demonstrating that these equations reduce to the well-known dispersion equations for the limiting cases of round and planar jets. It is shown that the effect of the ellipticity is to increase the growth rate over a large range of wavenumbers in comparison to those of a circular jet. For higher Weber numbers, at which capillary forces have a stabilizing effect, the growth rate decreases with increasing ellipticity. Similar to circular and planar jets, increasing the density ratio between gas and liquid increases the growth of disturbances significantly. These theoretical investigations are complemented by experiments to validate the local linear stability results. Comparisons of predicted growth rates with measurements over a range of jet ellipticities confirm that the theoretical model provides a quantitatively accurate description of the instability dynamics in the Rayleigh and first wind-induced regimes.
Hydrodynamic interaction between a capsule and a solid boundary in unbounded Stokes flow
Authors: Keh M. P. , Walter J. , Leal L. G.
Published: November 2014

Dynamics of the hydrodynamic thin film drainage between a capsule and a solid boundary in flow is crucial to adhesion of capsules, and therefore, to the stability and effectiveness of capsule products. Although there have been numerous studies for drops and initially stress-free vesicles, this phenomenon is still not well understood when capsules or preinflated membrane bound particles are involved. Based on the existing theories for drops and vesicles, we have derived scaling theories in a more general way to allow for a non-uniform and non-isotropic tension profile on the membrane, which is usually the case for capsules, and also included the effect of preinflation. These scaling theories were then compared with simulations using a numerical model coupling the boundary integral method for the motion of the fluids and a finite element method for the membrane mechanics. Surprisingly, we find that the only relevant modulus for capsules in the drainage process is the area dilation modulus Ks, which is often deemed to be of secondary importance compared to the shear modulus Gs or the surface Young's modulus in studies of capsule dynamics. This leads to the fact that the drainage behavior of an initially stress-free capsule is similar to an initially stress-free vesicle, in spite of the additional shear modulus that is present for capsules. We also find that the drainage behavior of a prestressed capsule or a prestressed vesicle is similar to a drop with an immobile interface in a weak flow.
Quantitative chemical exchange saturation transfer with hyperpolarized nuclei (qHyper-CEST): Sensing xenon-host exchange dynamics and binding affinities by NMR
Authors: Kunth M. , Witte C. , Schröder L.
Published: November 2014

The reversible binding of xenon to host molecules has found numerous applications in nuclear magnetic resonance studies. Quantitative characterization of the Xe exchange dynamics is important to understand and optimize the physico-chemical behavior of such Xe hosts, but is often challenging to achieve at low host concentrations. We have investigated a sensitive quantification technique based on chemical exchange saturation transfer with hyperpolarized nuclei, qHyper-CEST. Using simulated signals we demonstrated that qHyper-CEST yielded accurate and precise results and was robust in the presence of large amounts of noise (10%). This is of particular importance for samples with completely unknown exchange rates. Using these findings we experimentally determined the following exchange parameters for the Xe host cryptophane-A monoacid in dimethyl sulfoxide in one type of experiment: the ratio of bound and free Xe, the Xe exchange rate, the resonance frequencies of free and bound Xe, the Xe host occupancy, and the Xe binding constant. Taken together, qHyper-CEST facilitates sensitive quantification of the Xe exchange dynamics and binding to hydrophobic cavities and has the potential to analyze many different host systems or binding sites. This makes qHyper-CEST an indispensable tool for the efficient design of highly specific biosensors.
Nanoscale phase separation in epitaxial Cr-Mo and Cr-V alloy thin films studied using atom probe tomography: Comparison of experiments and simulation
Authors: Devaraj A. , Kaspar T. C. , Ramanan S. , Walvekar S. , Bowden M. E. , Shutthanandan V. , Kurtz R. J.
Published: November 2014

Tailored metal alloy thin film-oxide interfaces generated using molecular beam epitaxy (MBE) deposition of alloy thin films on a single crystalline oxide substrate can be used for detailed studies of irradiation damage response on the interface structure. However, the presence of nanoscale phase separation in the MBE grown alloy thin films can impact the metal-oxide interface structure. Due to nanoscale domain size of such phase separation, it is very challenging to characterize by conventional techniques. Therefore, laser assisted atom probe tomography (APT) was utilized to study the phase separation in epitaxial Cr0.61Mo0.39, Cr0.77Mo0.23, and Cr0.32V0.68 alloy thin films grown by MBE on MgO(001) single crystal substrates. Statistical analysis, namely frequency distribution analysis and Pearson coefficient analysis of experimental data was compared with similar analyses conducted on simulated APT datasets with known extent of phase separation. Thus, the presence of phase separation in Cr-Mo films, even when phase separation was not clearly observed by x-ray diffraction, and the absence of phase separation in the Cr-V film were confirmed.
Analytic results for spatial coherence and information entropy of an optical vortex field
Authors: Coffey Mark W.
Published: November 2014

Optical vortex fields have applications in information processing and storage and in the manipulation of microscopic particles. We present analytic results for quantities describing the extent of spatial coherence and entropy of one-dimensional projections of a vortex field. Sums of squares of values of certain Jacobi polynomials are important in the analysis. A family of summation identities is presented that provides the moments of an associated discrete probability distribution.
Characteristics of the positive ion source at reduced gas feed
Authors: Sharma S. K. , Bharathi P. , Prahlad V. , Patel P. J. , Choksi B. , Jana M. R. , Bansal L. K. , Qureshi K. , Sumod C. B. , Vadher V. , Thakkar D. , Gupta L. N. , Rambabu S. , Parmar S. , Contractor N. , Sahu A. K. , Pandya B. , Sridhar B. , Pandya S. , Baruah U. K.
Published: November 2014

The neutral beam injector of steady state superconducting tokamak (SST1-NBI) at IPR is designed for injecting upto 1.7 MW of neutral beam (Hº, 30–55 keV) power to the tokamak plasma for heating and current drive. Operations of the positive ion source (PINI or Plug-In-Neutral-Injector) of SST1-NBI were carried out on the NBI test stand. The PINI was operated at reduced gas feed rate of 2–3 Torr l/s, without using the high speed cryo pumps. Experiments were conducted to achieve a stable beam extraction by optimizing operational parameters namely, the arc current (120–300 A), acceleration voltage (16–40 kV), and a suitable control sequence. The beam divergence, power density profiles, and species fractions (H+:H2+:H3+) were measured by using the diagnostics such as thermal calorimetry, infrared thermography, and Doppler shift spectroscopy. The maximum extracted beam current was about 18 A. A further increase of beam current was found to be limited by the amount of gas feed rate to the ion source.
Hydrogen passivation of interstitial iron in boron-doped multicrystalline silicon during annealing
Authors: Liu AnYao , Sun Chang , Macdonald Daniel
Published: November 2014

Effective hydrogenation of interstitial iron in boron-doped multicrystalline silicon wafers is reported. The multicrystalline silicon wafers were annealed with plasma-enhanced chemical vapour deposited silicon nitride films, at temperatures of 400 °C – 900 °C and for times from minutes to hours. At low temperatures where a combined effect of hydrogenation and precipitation of dissolved Fe is expected, results show that the hydrogenation process dominates the effect of precipitation. The concentrations of dissolved interstitial iron reduce by more than 90% after a 30-min anneal at temperatures between 600 and 900 °C. The most effective reduction occurs at 700 °C, where 99% of the initial dissolved iron is hydrogenated after 30 min. The results show that the observed reductions in interstitial Fe concentrations are not caused by the internal gettering of Fe at structural defects or by an enhanced diffusivity of Fe due to the presence of hydrogen. The hydrogenation process is conjectured to be the pairing of positively charged iron with negatively charged hydrogen, forming less recombination active Fe-H complexes in silicon.
Inertial migration of deformable droplets in a microchannel
Authors: Chen Xiaodong , Xue Chundong , Zhang Li , Hu Guoqing , Jiang Xingyu , Sun Jiashu
Published: November 2014

The microfluidic inertial effect is an effective way of focusing and sorting droplets suspended in a carrier fluid in microchannels. To understand the flow dynamics of microscale droplet migration, we conduct numerical simulations on the droplet motion and deformation in a straight microchannel. The results are compared with preliminary experiments and theoretical analysis. In contrast to most existing literature, the present simulations are three-dimensional and full length in the streamwise direction and consider the confinement effects for a rectangular cross section. To thoroughly examine the effect of the velocity distribution, the release positions of single droplets are varied in a quarter of the channel cross section based on the geometrical symmetries. The migration dynamics and equilibrium positions of the droplets are obtained for different fluid velocities and droplet sizes. Droplets with diameters larger than half of the channel height migrate to the centerline in the height direction and two equilibrium positions are observed between the centerline and the wall in the width direction. In addition to the well-known Segré-Silberberg equilibrium positions, new equilibrium positions closer to the centerline are observed. This finding is validated by preliminary experiments that are designed to introduce droplets at different initial lateral positions. Small droplets also migrate to two equilibrium positions in the quarter of the channel cross section, but the coordinates in the width direction are between the centerline and the wall. The equilibrium positions move toward the centerlines with increasing Reynolds number due to increasing deformations of the droplets. The distributions of the lift forces, angular velocities, and the deformation parameters of droplets along the two confinement direction are investigated in detail. Comparisons are made with theoretical predictions to determine the fundamentals of droplet migration in microchannels. In addition, existence of the inner equilibrium position is linked to the quartic velocity distribution in the width direction through a simple model for the slip angular velocities of droplets.
X-ray conversion efficiency and radiation non-uniformity in the hohlraum experiments at Shenguang-III prototype laser facility
Authors: Zhang Huasen , Yang Dong , Song Peng , Zou Shiyang , Zhao Yiqing , Li Sanwei , Li Zhichao , Guo Liang , Wang Feng , Peng Xiaoshi , Wei Huiyue , Xu Tao , Zheng Wudi , Gu Peijun , Pei Wenbing , Jiang Shaoen , Ding Yongkun
Published: November 2014

The hohlraum radiation properties are studied experimentally by the Shenguang-III prototype laser facility and numerically by the two-dimensional code LARED with the multi-group radiation transfer model. The measured radiation temperature is consistent with the prediction of the simulations in a wide laser energy range, suggesting that the x-ray conversion efficiency is around 75% at the peak radiation temperature. The delicate hohlraum experiments further show that the radiation intensity inside the hohlraum is significantly non-uniform. The measured radiation flux of the hot spot region is over twice higher than that of the re-emitted wall region. Good agreements between the experiments and simulations further demonstrate the validity of the LARED code to study the hohlraum radiation properties.
Whistler wave radiation from a pulsed loop antenna located in a cylindrical duct with enhanced plasma density
Authors: Kudrin Alexander V. , Shkokova Natalya M. , Ferencz Orsolya E. , Zaboronkova Tatyana M.
Published: November 2014

Pulsed radiation from a loop antenna located in a cylindrical duct with enhanced plasma density is studied. The radiated energy and its distribution over the spatial and frequency spectra of the excited waves are derived and analyzed as functions of the antenna and duct parameters. Numerical results referring to the case where the frequency spectrum of the antenna current is concentrated in the whistler range are reported. It is shown that under ionospheric conditions, the presence of an artificial duct with enhanced density can lead to a significant increase in the energy radiated from a pulsed loop antenna compared with the case where the same source is immersed in the surrounding uniform magnetoplasma. The results obtained can be useful in planning active ionospheric experiments with pulsed electromagnetic sources operated in the presence of artificial field-aligned plasma density irregularities that are capable of guiding whistler waves.
Reconstruction by fluorescence imaging of the spatio-temporal evolution of the viscosity field in Hele-Shaw flows
Authors: Bunton P. , Dice B. , Pojman J. A. , De Wit A. , Brau F.
Published: November 2014

We study the spatio-temporal evolution of the viscosity field during stable and unstable radial flows of glycerol-water solutions in a horizontal Hele-Shaw cell where a localized temperature gradient is imposed. The viscosity field is reconstructed from the measurement of the fluorescence emitted by a viscosity-sensitive molecular probe (Auramine O). For an immiscible flow, the viscosity and temperature fields are obtained accurately. For miscible displacements, we show how the interplay between the viscosity changes of both fluids and the variation of the fluid thickness in the gap prevents obtaining strict quantitative reconstruction of the viscosity field. We explain how the reconstructed viscosity field can nevertheless be interpreted to obtain information about the fluid thickness and the local viscosity and temperature.
High-frequency thermal-electrical cycles for pyroelectric energy conversion
Authors: Bhatia Bikram , Damodaran Anoop R. , Cho Hanna , Martin Lane W. , King William P.
Published: November 2014

We report thermal to electrical energy conversion from a 150 nm thick BaTiO3 film using pyroelectric cycles at 1 kHz. A microfabricated platform enables temperature and electric field control with temporal resolution near 1 μs. The rapid electric field changes as high as 11 × 105 kV/cm-s, and temperature change rates as high as 6 × 105 K/s allow exploration of pyroelectric cycles in a previously unexplored operating regime. We investigated the effect of phase difference between electric field and temperature cycles, and electric field and temperature change rates on the electrical energy generated from thermal-electrical cycles based on the pyroelectric Ericsson cycle. Complete thermodynamic cycles are possible up to the highest cycle rates tested here, and the energy density varies significantly with phase shifts between temperature and electric field waveforms. This work could facilitate the design and operation of pyroelectric cycles at high cycle rates, and aid in the design of new pyroelectric systems.