bluuebunny/crossref_metadata_2025 huggingface dataset:
FDR Explorer
Authors: Freitas Leo , Woodcock Jim
Published: April 2008

We describe: (1) the internal structures of FDR, the refinement model checker for Hoare’s Communicating Sequential Processes (CSP); and (2) an application-programming interface (API) that allows users to interact more closely with FDR and to have finer-grain control over its behaviour and data structures. This API makes it possible to create optimised CSP code to perform refinement checks that are more space or time efficient, enabling the analysis of more complex and data-intensive specifications. The API can be used either by those constructing CSP models or by tools that automatically generate CSP code. We present examples of using our tool, including handling advanced FDR features such as transparent functions, which compress state spaces before checking. We also show how to transform FDR’s graph format into a graph notation such as JGraph, enabling visualisation of labelled transition systems of CSP specifications.
The effect of vaccination with the lysate of heat‐shocked tumor cells on nitric oxide production in BALB/c mice with fibrosarcoma tumor
Authors: Hashemi Seyed Mahmoud , Hassan Zuhair M. , Soudi Sara , Shahabi Shahram
Published: April 2008

The aim of this study was to investigate the effect of heat shock protein‐70 (HSP‐70) on splenocyte proliferation and nitric oxide (NO) production in the BALB/c mice fibrosarcoma tumor model. To do so, HSP‐70 was induced in the lysate of heat‐shocked tumor cells and WEHI‐164 cells (mouse fibrosarcoma cell line) were injected subcutaneously into the right flank of inbred BALB/c mice to establish a tumor model. Three animal bearing tumor groups were applied: the test group; vaccinated with HSP‐70 enriched tumor lysate; control group I, vaccinated with tumor lysate only; and control group II, which received PBS. Using immunoblot analysis, an increase of HSP‐70 expression was detected in the lysate of heat‐shocked cells in comparison with non‐heat‐shocked cells. The effect of the test lysate on NO production was measured both in vitro and in vivo in the peritoneal macrophages and splenocytes of tumor bearing mice, respectively. The result showed a significant increase in NO production both in vitro by peritoneal macrophages and in vivo after immunization with HSP‐70 enriched tumor lysate. In addition, tumor growth was significantly postponed and the proliferation of splenocytes was increased in the test group. Our results indicate that the lysate of heat‐shocked tumor cells was more potent than that of non‐heat‐shocked tumor cells in inducing anti‐tumor immunity. Since production of NO by HSP‐activated antigen presenting cells (APCs) is likely to affect innate immunity and tumor growth, the probable mechanism of postponing tumor growth would be NO production by innate immune cells. These findings provide a useful therapeutic model for developing novel approaches to cancer treatments.
Detection of cross‐links between FtsH, YidC, HflK/C suggests a linked role for these proteins in quality control upon insertion of bacterial inner membrane proteins
Authors: van Bloois Edwin , Dekker Henk L. , Fröderberg Linda , Houben Edith N.G. , Urbanus Malene L. , de Koster Chris G. , de Gier Jan-Willem , Luirink Joen
Published: April 2008

MINT‐6478034:

hflB (uniprotkb:P0AAI3) physically interacts (MI:0218) with yidC (uniprotkb:P25714), hflK (uniprotkb:P0ABC7), hflC (uniprotkb:P0ABC3) by cross-linking studies (MI:0030)

MINT‐6478363:

yidC (uniprotkb:P25714) physically interacts (MI:0218) with lldD (uniprotkb:P33232), rplD (uniprotkb:P60723), yrbD (uniprotkb:P64604), rpsA (uniprotkb:P0AG67), aphA1 (uniprotkb:P00551), dacC (uniprotkb:P08506), rpsC (uniprotkb:P0A7V3), rpsD (uniprotkb:P0A7V8), rpsE (uniprotkb:P0A7W1), rpoA (uniprotkb:P0A7Z4), ompC (uniprotkb:P06996), ompA (uniprotkb:P0A910), atpA (uniprotkb:P0ABB0), atpD (uniprotkb:P0ABB4), adhE (uniprotkb:P0A9Q7),hflB (uniprotkb:P0AAI3), hflC (uniprotkb:P0ABC3), hflK (uniprotkb:P0ABC7), lacI (uniprotkb:P03023), gapA (uniprotkb:P0A9B2), rbsB (uniprotkb:P02925), sdhA (uniprotkb:P0AC41), rho (uniprotkb:P0AG30), udp (uniprotkb:P12758), nuoC (uniprotkb:P33599), treB (uniprotkb:P36672) and manX (uniprotkb:P69797) by cross-linking studies (MI:0030)

MINT‐6477988:

yidC (uniprotkb:P25714) physically interacts (MI:0218) with hflB (uniprotkb:P0AAI3), hflK (uniprotkb:P0ABC7), hflC (uniprotkb:P0ABC3), secD (uniprotkb:P0AG90) and secG (uniprotkb:P0AG99) by cross-linking studies (MI:0030)

MINT‐6478012:

yidC (uniprotkb:P25714) physically interacts (MI:0218) with hflC(uniprotkb:P0ABC3) and hflK (uniprotkb:P0ABC7) by cross-linking studies (MI:0030)
Small heat shock protein Hsp27 protects myosin S1 from heat‐induced aggregation, but not from thermal denaturation and ATPase inactivation
Authors: Markov Denis I. , Pivovarova Anastasia V. , Chernik Ivan S. , Gusev Nikolai B. , Levitsky Dmitrii I.
Published: April 2008

MINT‐6490863, MINT‐6490872:

LC1 (S1) (uniprotkb:P02602), Myosin subfragment 1 (S1) (uniprotkb:P02562) and Hsp27 (uniprotkb:P04792) physically interact (MI:0218) by dynamic light scattering (MI:0038)

MINT‐6490833:

LC1 (S1) (uniprotkb:P02602), Myosin subfragment 1 (S1) (uniprotkb:P02562) and Hsp27 (uniprotkb:P04792) physically interact (MI:0218) by cosedimentation (MI:0027)

MINT‐6490770, MINT‐6490782:

LC1 (S1) (uniprotkb:P02602), Myosin subfragment 1 (S1) (uniprotkb:P02562) and Hsp27 (uniprotkb:P04792) physically interact (MI:0218) by light scattering (MI:0067)
Trends in the global funding and activity of cancer research
Authors: Eckhouse Seth , Lewison Grant , Sullivan Richard
Published: April 2008

Cancer research has carved an astonishing trajectory giving rise to a multi billion euro global network covering most domains of science and including all manner of research funders from industry to government and philanthropic funders. We have estimated that in 2004/2005 the global spend on cancer research was 14,030 million euros, with the USA, dominated by the NCI (c. 83%) accounting for the largest absolute spend. This is between 2 and 3 times the level of per capita spend compared to EU‐15 and Europe, respectively. In Europe, the UK is at comparable levels of spend compared to the USA. Funding for cancer research in Europe is split almost 50:50 between philanthropic and governmental sources. Cancer research productivity in terms of outputs (publications) is slightly greater in Europe compared to the USA with an increasing trend towards more applied (clinical) outputs. Both the USA and Europe have equally strong industry‐supported output levels.
Methods to study degradation of ruminant feeds
Authors: Mohamed Ruba , Chaudhry Abdul Shakoor
Published: April 2008

Ruman degradation is crucial in the supply of dietary nutrients to meet the nutrient demands of the anaerobic microbes and body tissues of ruminant animals. Therefore, it is essential to study the dynamics of rumen degradation of various feeds before their potential use to formulate nutritious diets for ruminant animals. Amongst many methods that have been used in the past, thein saccomethod has been the most effective method to study rumen degradation. However, this method is undesirable due to its implications for animal welfare and costs. While manyin vitromethods have been tested as possible alternatives to thein saccomethod to study rumen degradation of feeds, they were unable to remove the need to use fistulated animals to obtain rumen fluid. Although solubility, enzyme- and faeces-basedin vitromethods do not require rumen fluid, they still need data from either thein saccomethod or the rumen fluid-basedin vitromethods for comparison and validation. Therefore, there is a need to developin vitromethods that do not require the need to surgically modify ruminants to obtain rumen fluid to study rumen degradation. We review the potentials and problems associated with the existing methods to study rumen degradation and their implications for the animal industry in different situations.
Schulung von Patienten mit Herzinsuffizienz – Effekte auf das Selbstpflegeverhalten. Eine Literaturrecherche
Authors: Grossmann Florian F. , Mahrer-Imhof Romy
Published: April 2008

Herzinsuffizienz ist eine häufige chronische Erkrankung, deren Prävalenz weiter zunehmen wird. In der Literatur sind zahlreiche Interventionen für Patienten mit Herzinsuffizienz beschrieben, deren zentraler Bestandteil Patientenschulung und -beratung durch Pflegende ist. In dieser Arbeit wurde mittels einer Literaturrecherche der Zusammenhang zwischen Patientenschulung und verbessertem Selbstpflegeverhalten von Patienten mit Herzinsuffizienz untersucht. Sieben randomisierte kontrollierte Studien konnten eingeschlossen werden. Wichtige Inhalte von Schulungsprogrammen sind Medikamenteneinnahme, tägliches Wiegen, Salz- und Flüssigkeitsrestriktion und das Ergreifen konkreter Maßnahmen bei zunehmender Symptomatik. Die Studien zeigten übereinstimmend, dass Interventionen, die eine Patientenschulung beinhalten, einen positiven Effekt auf das Selbstpflegeverhalten von Patienten mit Herzinsuffizienz haben. Die Schulung muss an die Patienten individuell angepasst sein, und Familienmitglieder sollten integriert werden. Pflegende müssen für die Patientenschulung und -beratung gut ausgebildet sein, um zum Beispiel ein klinisches Assessment durchführen zu können. Die optimale Dauer und der Umfang der Patientenschulung, die nötig sind, um das Selbstpflegeverhalten effektiv und nachhaltig zu verbessern, sind noch unklar und verlangen nach weiterer Forschung.
Pathologische Darmbefunde: Fallbezogene Differentialdiagnose und Abklärung
Authors: Kehl Oth.
Published: April 2008

Die transabdominelle Sonographie ist bei intestinalen Erkrankungen die am häufigsten verwendete Erstuntersuchung, die sich dank hoher Verfügbarkeit und fehlender Strahlennebenwirkungen auch als Verlaufsuntersuchung optimal eignet. Neuere Techniken wie das «Tissue Harmonic Imaging» zusammen mit dem Einsatz von Kontrastmitteln scheinen die diagnostische Treffsicherheit bei chronisch entzündlichen Darmerkrankungen zu erhöhen. Für die Divertikulitis, die infektiösen Kolitiden und die Darm-Tumoren fehlen diesbezügliche Daten bis anhin. Anhand typischer Fallbeispiele werden die sonomorphologischen Kriterien wichtiger intestinaler Krankheitsbilder aufgezeigt.
Das Endocannabinoid-System
Authors: Sudano I. , Périat D. , Noll G.
Published: April 2008

Das Endocannabinoidsystem ist ein physiologisches System, welches unter anderem für die Kontrolle des Energiegleichgewichtes, den Glukose- und Lipidmetabolismus sowie für die Regulation des Körpergewichtes verantwortlich ist. Die Endocannabinoid- Rezeptoren sind sowohl im zentralen Nervensystem als auch in der Peripherie verteilt. Durch verschiedene Studien wird belegt, dass ein hyperaktives Endocannabinoidsystem für die Entwicklung verschiedener kardialer und metabolischer Risikofaktoren von Bedeutung ist. Die medikamentöse Blockierung des Cannabinoid-1- Rezeptors kann einen neuen Ansatz zur Beeinflussung von kardiometabolischer Risikofaktoren darstellen.
Placental site trophoblastic tumor - Ein Fallbericht und Literaturübersicht
Authors: Kunz, J. , Bannwart F.
Published: April 2008

Vorgestellt wird eine 32-jährige III-Para, bei welcher sich anlässlich der zweiten und der dritten Sectio caesarea eine stille Uterusruptur fand. Nach der dritten Sectio caesarea bestand in der Stillphase während fünf Monaten eine geringgradige uterine Blutung, dann stellte sich unter oraler Kontrazeption eine Amenorrhoe ein. Regelmässige klinische und sonographische Kontrollen zeigten negative Serum-β- HCG-Werte und eine retrovesikale Resistenz, die nach 18 Monaten an Grösse zunahm und symptomatisch wurde. Bei abgeschlossener Familienplanung erfolgte die abdominale Hysterektomie ohne Adnexektomie. Histologisch zeigte sich ein Placental site trophoblastic tumor (PSTT), ein seltener trophoblastärer Tumor mit malignem Potential, dessen Prognose abhängig ist vom primären Tumorstadium, dem Zeitintervall zwischen letzter Schwangerschaft und Erkrankung, dem Alter der Patientin sowie der Mitoserate, und dessen Verlauf mit dem Prognosescore für trophoblastäre Erkrankungen der WHO nicht abgeschätzt werden kann. Therapeutisch empfohlen wird die Hysterektomie. Die Chemosensitivität ist gering und wegen der Seltenheit der Tumoren ist das geeignetste Chemotherapie-Schema nicht bekannt. Bei metastasierenden oder rezidivierenden PSTT hat sich das EP/EMA-Regime als am effektivsten erwiesen.
Age, spreading rates, and spreading asymmetry of the world's ocean crust
Authors: Müller R. Dietmar , Sdrolias Maria , Gaina Carmen , Roest Walter R.
Published: April 2008

We present four companion digital models of the age, age uncertainty, spreading rates, and spreading asymmetries of the world's ocean basins as geographic and Mercator grids with 2 arc min resolution. The grids include data from all the major ocean basins as well as detailed reconstructions of back‐arc basins. The age, spreading rate, and asymmetry at each grid node are determined by linear interpolation between adjacent seafloor isochrons in the direction of spreading. Ages for ocean floor between the oldest identified magnetic anomalies and continental crust are interpolated by geological estimates of the ages of passive continental margin segments. The age uncertainties for grid cells coinciding with marine magnetic anomaly identifications, observed or rotated to their conjugate ridge flanks, are based on the difference between gridded age and observed age. The uncertainties are also a function of the distance of a given grid cell to the nearest age observation and the proximity to fracture zones or other age discontinuities. Asymmetries in crustal accretion appear to be frequently related to asthenospheric flow from mantle plumes to spreading ridges, resulting in ridge jumps toward hot spots. We also use the new age grid to compute global residual basement depth grids from the difference between observed oceanic basement depth and predicted depth using three alternative age‐depth relationships. The new set of grids helps to investigate prominent negative depth anomalies, which may be alternatively related to subducted slab material descending in the mantle or to asthenospheric flow. A combination of our digital grids and the associated relative and absolute plate motion model with seismic tomography and mantle convection model outputs represents a valuable set of tools to investigate geodynamic problems.
Mineralogy as a critical factor of dust iron solubility
Authors: Journet Emilie , Desboeufs Karine V. , Caquineau Sandrine , Colin Jean‐Louis
Published: April 2008

To understand the impact of dust deposition on ocean primary productivity, the evaluation of dust input is not sufficient, and the soluble iron supply is also needed. Measurements of iron in aerosols suggest a much higher solubility than in soil, implying substantial atmospheric processing of chemical or physical nature. Here, we have investigated the effect of the mineralogy on iron solubility. We have measured iron solubility from some minerals commonly found in dust (clay, feldspar and iron (hydr‐)oxides). Firstly, we observe a greater solubility of iron resulting from clays (~4%) in comparison to iron (hydr‐)oxides (<1%), independently of specific surface of minerals. Secondly, by considering amount of dissolved iron and the mineralogical composition of dust, our results indicate that dissolved iron fraction mainly comes from clay dissolution in contrast to that assumed in some biogeochemical models. In consequence, it appears that iron solubility is closely linked to the mineralogical composition of aerosol.
Role of Korteweg stresses in geodynamics
Authors: Morra Gabriele , Yuen David A.
Published: April 2008

It has come to our attention that the constitutive relationship used in the modeling of geodynamical flow problems with strongly variable physical properties, should have additional terms in the stress tensor, known in the literature as Korteweg stresses (K‐stresses). These stresses arising at diffuse interfaces, which can best be explained in terms of density gradients, have already been mentioned in the literature for more than one hundred years, but have not received attention recently until a combination of experimental and numerical evidence have confirmed their existence. We will discuss the important potential role these new terms have for geophysics. It has many ramifications in geodynamics, ranging from mantle convection to earthquakes and magma fragmentation.
Observations of a comet tail disruption induced by the passage of a CME
Authors: Kuchar T. A. , Buffington A. , Arge C. N. , Hick P. P. , Howard T. A. , Jackson B. V. , Johnston J. C. , Mizuno D. R. , Tappin S. J. , Webb D. F.
Published: April 2008

The Solar Mass Ejection Imager observed an extremely faint interplanetary coronal mass ejection (ICME) as it passed Comet C/2001 Q4 (NEAT) on 5 May 2004, apparently causing a disruption of its plasma tail. This is the first time that an ICME has been directly observed interacting with a comet. SMEI's nearly all‐sky coverage and image cadence afforded unprecedented coverage of this rarely observed event. The onset first appeared as a “kink” moving antisunward that eventually developed knots within the disturbed tail. These knots appeared to be swept up in the solar wind flow. We present the SMEI observations as well as identify a likely SOHO/LASCO progenitor of the CME. SMEI observed two other comets (C/2002 T7 [LINEAR] and C/2004 F4 [Bradfield]) and at least five similar events during a 35‐d period encompassing this observation. Although these had similar morphologies to the 5 May NEAT event, SMEI did not observe any ICMEs in these cases. Three of these were observed close to the heliospheric current sheet indicating that a magnetic boundary crossing may have contributed to the disruptions. However, there are no discernable causes in the SMEI observations for the remaining two events.
Solar wind plasma entry into the magnetosphere under northward IMF conditions
Authors: Li Wenhui , Raeder Joachim , Thomsen Michelle F. , Lavraud Benoit
Published: April 2008

This study examines how solar wind plasma enters the magnetosphere under northward interplanetary magnetic field (IMF) conditions, using the Open Geospace General Circulation Model (OpenGGCM) for various solar wind, IMF, and geomagnetic dipole conditions. We trace flow paths of individual fluid elements from the solar wind and study the variation of the topology of the magnetic field line along those flow paths. We find that there is an entry window through which the solar wind plasma can enter the magnetosphere as a result of double high‐latitude reconnection under northward IMF conditions. We investigate how the entry window depends on solar wind, IMF, and geomagnetic dipole parameters, and we estimate the solar wind plasma entry rate for various conditions. We find that the effective entry rate under northward IMF conditions is of the order of 1026 to 1027 particles per second. We also estimate the conditions for which solar wind plasma entry is most efficient. The newly created flux tubes with closed‐field topology are subsequently convected to the nightside and consequently cause magnetosheath plasma to be captured and enter the magnetosphere. Some captured dayside plasma takes about 90 min to convect along the magnetopause to a near tail flank region of the central plasma sheet, thus forming a cold dense plasma sheet. Double high‐latitude reconnection can also release the captured plasma. Thus a balance of inflow and outflow of the captured plasma is eventually established under prolonged northward IMF conditions. We find that high‐latitude reconnection is common under northward IMF conditions in our simulations. It occurs for IMF with any clock angle within [−90°, 90°], measured in front of the bow shock, and for any geomagnetic dipole tilt angle within [−30°, 30°]. An IMF field line with a zero x component usually first reconnects with a geomagnetic field line at the northern high‐latitude boundary when the geomagnetic dipole tilts positive toward the Sun, and vice versa for negative dipole tilt. Our simulations also show that ionosphere conductance affects the convection of the newly closed field lines. Consequently, ionosphere conductance can change the solar wind plasma effective entry rate and can cause asymmetric effective entry rate with respect to positive and negative IMF clock angles.
Ionospheric scintillation effects on single frequency GPS
Authors: Steenburgh R. A. , Smithtro C. G. , Groves K. M.
Published: April 2008

Ionospheric scintillation of Global Positioning System (GPS) signals threatens navigation and military operations by degrading performance or making GPS unavailable. Scintillation is particularly active within, although not limited to, a belt encircling the Earth within 20 degrees of the geomagnetic equator. As GPS applications and users increase, so does the potential for degraded precision and availability from scintillation. We examined amplitude scintillation data spanning 7 years from Ascension Island, U.K.; Ancon, Peru; and Antofagasta, Chile in the Atlantic/American longitudinal sector as well as data from Parepare, Indonesia; Marak Parak, Malaysia; Pontianak, Indonesia; Guam; and Diego Garcia, U.K. in the Pacific longitudinal sector. From these data, we calculate percent probability of occurrence of scintillation at various intensities described by the S4 index. Additionally, we determine Dilution of Precision at 1 min resolution. We examine diurnal, seasonal, and solar cycle characteristics and make spatial comparisons. In general, activity was greatest during the equinoxes and solar maximum, although scintillation at Antofagasta, Chile was higher during 1998 rather than at solar maximum.
Slip reversals on active normal faults related to the inflation and deflation of magma chambers: Numerical modeling with application to the Yellowstone‐Teton region
Authors: Hampel Andrea , Hetzel Ralf
Published: April 2008

Earthquakes and coseismic slip on faults are the common response of Earth's crust to plate‐tectonic forces. Here we demonstrate, using three‐dimensional numerical experiments, that pulses of magmatic activity may alter the slip behavior of nearby tectonic faults by causing unusual aseismic creep and even reversals in the sense of slip. We apply our results to the Teton normal fault, Wyoming, which experienced hitherto unexplained episodes of reverse and normal creep between 1988 and 2001, to show that its anomalous behavior can be explained by inflation and deflation of two magma chambers beneath the Yellowstone caldera. Our findings imply a strong coupling between magmatism and tectonic faulting, which requires coordinated monitoring of both processes to improve our understanding of the resulting spatial and temporal strain pattern.
Acute Functional Recovery of Cerebral Blood Flow after Forebrain Ischemia in Rat
Authors: Zhou Chao , Shimazu Tomokazu , Durduran Turgut , Luckl Janos , Kimberg Daniel Y , Yu Guoqiang , Chen Xiao-Han , Detre John A. , Yodh Arjun G , Greenberg Joel H
Published: April 2008

After complete cerebral ischemia, the postischemic blood flow response to functional activation is severely attenuated for several hours. However, little is known about the spatial and temporal extent of the blood flow response in the acute postischemic period after incomplete cerebral ischemia. To investigate the relative cerebral blood flow (rCBF) response in the somatosensory cortex of rat to controlled vibrissae stimulation after transient incomplete ischemia (15-min bilateral common carotid artery occlusion + hypotension), we employed laser speckle imaging combined with statistical parametric mapping. We found that the ischemic insult had a significant impact on the baseline blood flow ( P <0.005) and the activation area in response to functional stimulation was significantly reduced after ischemia ( P < 0.005). The maximum rCBF response in the activation area determined from the statistical analysis did not change significantly up to 3 h after ischemia ( P > 0.1). However, the time when rCBF response reached its maximum was significantly delayed ( P < 0.0001) from 2.4 ± 0.2 secs before ischemia to 3.6 ± 0.1 secs at 20 mins into reperfusion ( P < 0.001); the delay was reduced gradually to 2.9 ± 0.2 secs after 3 h, which was still significantly greater than that observed before the insult ( P = 0.04).
Gene Expression in Peripheral Blood Differs after Cardioembolic Compared with Large-Vessel Atherosclerotic Stroke: Biomarkers for the Etiology of Ischemic Stroke
Authors: Xu Huichun , Tang Yang , Liu Da-Zhi , Ran Ruiqiong , Ander Bradley P , Apperson Michelle , Liu Xin She , Khoury Jane C , Gregg Jeffrey P , Pancioli Arthur , Jauch Edward C , Wagner Kenneth R , Verro Piero , Broderick Joseph P , Sharp Frank R
Published: April 2008

There are no biomarkers that differentiate cardioembolic from large-vessel atherosclerotic stroke, although the treatments differ for each and ~30% of strokes and transient ischemic attacks have undetermined etiologies using current clinical criteria. We aimed to define gene expression profiles in blood that differentiate cardioembolic from large-vessel atherosclerotic stroke. Peripheral blood samples were obtained from healthy controls and acute ischemic stroke patients (< 3, 5, and 24 h). RNA was purified, labeled, and applied to Affymetrix Human U133 Plus 2.0 Arrays. Expression profiles in the blood of cardioembolic stroke patients are distinctive from those of large-vessel atherosclerotic stroke patients. Seventy-seven genes differ at least 1.5-fold between them, and a minimum number of 23 genes differentiate the two types of stroke with at least 95.2% specificity and 95.2% sensitivity for each. Genes regulated in large-vessel atherosclerotic stroke are expressed in platelets and monocytes and modulate hemostasis. Genes regulated in cardioembolic stroke are expressed in neutrophils and modulate immune responses to infectious stimuli. This new method can be used to predict whether a stroke of unknown etiology was because of cardioembolism or large-vessel atherosclerosis that would lead to different therapy. These results have wide ranging implications for similar disorders.
Additive Effects of Statin and Dipyridamole on Cerebral Blood Flow and Stroke Protection
Authors: Kim Hyung-Hwan , Sawada Naoki , Soydan Guray , Lee Ho-Seong , Zhou Zhipeng , Hwang Seo-Kyoung , Waeber Christian , Moskowitz Michael A , Liao James K
Published: April 2008

Recent studies suggest that dipyridamole (DP) may exert stroke protective effects beyond platelet inhibition. The purpose of this study is to determine whether statin and DP could enhance stroke protection through nitric oxide (NO)-dependent vascular effects. Mice were pretreated with DP (10 to 60 mg/kg, q 12 h, 3 days) alone or in combination with a statin (simvastatin; 0.1 to 20 mg/kg per day, 14 days) before transient intraluminal middle cerebral artery occlusion. Although simvastatin (1 mg/kg per day, 14 days) increased endothelial NO synthase (eNOS) activity by 25% and DP (30 mg/kg, q12 h, 3 days) increased aortic cGMP levels by 55%, neither statin nor DP alone, at these subtherapeutic doses, increased absolute cerebral blood flow (CBF) or conferred stroke protection. However, the combination of subtherapeutic doses of simvastatin and DP increased CBF by 50%, decreased stroke volume by 54%, and improved neurologic motor deficits, all of which were absent in eNOS-deficient mice. In contrast, treatment with aspirin (10 mg/kg per day, 3 days) did not augment the neuroprotective effects of DP and/or simvastatin. These findings indicate that statin and DP exert additive NO-dependent vascular effects and suggest that the combination of statin and DP has greater benefits in stroke protection than statin alone through vascular protection.
Hepatocellular transport in acquired cholestasis: new insights into functional, regulatory and therapeutic aspects
Authors: Roma Marcelo G. , Crocenzi Fernando A. , Sánchez Pozzi Enrique A.
Published: April 2008

The recent overwhelming advances in molecular and cell biology have added enormously to our understanding of the physiological processes involved in bile formation and, by extension, to our comprehension of the consequences of their alteration in cholestatic hepatopathies. The present review addresses in detail this new information by summarizing a number of recent experimental findings on the structural, functional and regulatory aspects of hepatocellular transporter function in acquired cholestasis. This comprises (i) a short overview of the physiological mechanisms of bile secretion, including the nature of the transporters involved and their role in bile formation; (ii) the changes induced by nuclear receptors and hepatocyte-enriched transcription factors in the constitutive expression of hepatocellular transporters in cholestasis, either explaining the primary biliary failure or resulting from a secondary adaptive response; (iii) the post-transcriptional changes in transporter function and localization in cholestasis, including a description of the subcellular structures putatively engaged in the endocytic internalization of canalicular transporters and the involvement of signalling cascades in this effect; and (iv) a discussion on how this new information has contributed to the understanding of the mechanism by which anticholestatic agents exert their beneficial effects, or the manner in which it has helped the design of new successful therapeutic approaches to cholestatic liver diseases.
Energy loss magnetic chiral dichroism: A new technique for the study of magnetic properties in the electron microscope (invited)
Authors: Schattschneider P. , Rubino S. , Stoeger-Pollach M. , Hébert C. , Rusz J. , Calmels L. , Snoeck E.
Published: April 2008

The similarity between x-ray absorption near edge structure and electron energy loss near edge structure is well known. However, “exporting” x-ray magnetic circular dichroism (XMCD) to the transmission electron microscope (TEM) was considered impossible with present technology since electron probes possessing chirality (i.e., spin polarization) cannot be set up with sufficient intensity. But recently magnetically induced chiral electronic transitions were detected in the TEM. In analogy to XMCD we introduced the term EMCD (energy loss magnetic chiral dichroism). The mechanism builds upon the formal equivalence between the mixed dynamic form factor for inelastic electron scattering and the absorption cross section for x-rays. Experiments on the 3d ferromagnets show effects very similar to XMCD. Calculations based on the WIEN2K package are in good agreement with experiments. The recent improvement in signal strength and spatial resolution allows now to study atom specific spin and orbital moments on a scale of less than 10nm, an important progress for spintronics and nanomagnetism.
Properties and long range interactions of the calcium atom
Authors: Mitroy J. , Zhang J.-Y.
Published: April 2008

The properties of a number of states of calcium are determined from a large basis configuration interaction calculation. The main focus is on the polarizabilities of the low lying states (the 4s2Se1, 4s3dDe1,3, 4s4pPo1,3, and 4s5sSe1,3 states) and the dispersion interactions of those states with the calcium ground state, the hydrogen atom, and the rare gases.
Auxiliary density perturbation theory
Authors: Flores-Moreno Roberto , Köster Andreas M.
Published: April 2008

A new approach, named auxiliary density perturbation theory, for the calculation of second energy derivatives is presented. It is based on auxiliary density functional theory in which the Coulomb and exchange-correlation potentials are expressed by auxiliary function densities. Different to conventional coupled perturbed Kohn–Sham equations the perturbed density matrix is obtained noniteratively by solving an inhomogeneous equation system with the dimension of the auxiliary function set used to expand the auxiliary function density. A prototype implementation for the analytic calculation of molecular polarizabilities is presented. It is shown that the polarizabilities obtained with the newly developed auxiliary density perturbation approach match quantitative with the ones from standard density functional theory if augmented auxiliary function sets are used. The computational advantages of auxiliary density perturbation theory are discussed, too.
Adaptively biased molecular dynamics for free energy calculations
Authors: Babin Volodymyr , Roland Christopher , Sagui Celeste
Published: April 2008

We present an adaptively biased molecular dynamics (ABMD) method for the computation of the free energy surface of a reaction coordinate using nonequilibrium dynamics. The ABMD method belongs to the general category of umbrella sampling methods with an evolving biasing potential and is inspired by the metadynamics method. The ABMD method has several useful features, including a small number of control parameters and an O(t) numerical cost with molecular dynamics time t. The ABMD method naturally allows for extensions based on multiple walkers and replica exchange, where different replicas can have different temperatures and/or collective variables. This is beneficial not only in terms of the speed and accuracy of a calculation, but also in terms of the amount of useful information that may be obtained from a given simulation. The workings of the ABMD method are illustrated via a study of the folding of the Ace-GGPGGG-Nme peptide in a gaseous and solvated environment.
Effects of size constraint on water filling process in nanotube
Authors: Meng Lingyi , Li Qikai , Shuai Zhigang
Published: April 2008

Molecular dynamics (MD) simulation and the potential of mean force (PMF) analysis are used to investigate the structural properties of water molecules near the end of nanotube for the whole process from the initial water filling up to the configuration stabilization inside the carbon nanotubes (CNTs). Numerical simulations showed that when a small-sized nanotube is immersed into the water bath, the size constraint will induce a prevailing orientation for the water molecule to diffuse into the tube and this effect can persist approximately 3.3Å from the end of CNT. As the structure within the CNTs stabilizes, the ambient structural properties can indirectly reflect their corresponding properties inside the nanotube. Our results also showed that there exists a close correlation between the PMF analysis and the results of MD simulations, and the properties at nanometer scale are closely related to the size-constraint effect.
Floating nanodot gate memory fabrication with biomineralized nanodot as charge storage node
Authors: Miura Atsushi , Uraoka Yukiharu , Fuyuki Takashi , Yoshii Shigeo , Yamashita Ichiro
Published: April 2008

We have demonstrated floating nanodot gate memory (FNGM) fabrication by utilizing uniform biomineralized cobalt oxide (Co3O4) nanodots (Co-BNDs) which are biochemically synthesized in the vacant cavity of supramolecular protein, ferritin. High-density Co-BND array (>6.5×1011cm−2) formed on Si substrate with 3-nm-thick tunnel SiO2 is embedded in metal-oxide-semiconductor (MOS) stacked structure and used as the floating gate of FNGM. Fabricated Co-BND MOS capacitors and metal-oxide-semiconductor field effect transistors show the hysteresis loop due to the electron and hole confinement in the embedded Co-BND. Fabricated MOS memories show wide memory window size of 3–4V under 10V operation, good charge retention characteristics until 104s after charge programming, and stress endurance until 105 write/erase operation. Observed charge injection thresholds suggest that charge injection through the direct tunneling from Si to the energy levels in the conduction and valence bands of Co3O4 and long charge retention characteristics implies prompt charge confinement to the deeper energy level of metal Co which is formed during the annealing in the device processing.
Carrier concentration tuning of bandgap-reduced p-type ZnO films by codoping of Cu and Ga for improving photoelectrochemical response
Authors: Shet Sudhakar , Ahn Kwang-Soon , Yan Yanfa , Deutsch Todd , Chrustowski Kevin M. , Turner John , Al–Jassim Mowafak , Ravindra Nuggehalli
Published: April 2008

In this study, the synthesis of p-type ZnO films with similar bandgaps but varying carrier concentrations through codoping of Cu and Ga is reported. The ZnO:(Cu,Ga) films are synthesized by rf magnetron sputtering in O2 gas ambient at room temperature, followed by postdeposition annealing at 500°C in air for 2h. The bandgap reduction and p-type conductivity are caused by the incorporation of Cu. The tuning of carrier concentration is realized by varying the Ga concentration. The carrier concentration tuning does not significantly change the bandgap and crystallinity. However, it can optimize the carrier concentration to significantly enhance the photoelectrochemical response for bandgap-reduced p-type ZnO thin films.
Investigation of stress and morphology in electrodeposited copper nanofilms by cantilever beam method and in situ electrochemical atomic force microscopy
Authors: Ahmed S. , Ahmed T. T. , O’Grady M. , Nakahara S. , Buckley D. N.
Published: April 2008

Both stress and atomic force microscopy (AFM) measurements were carried out in situ during potentiostatic electrodeposition of copper on gold in 0.05moldm−3 CuSO4 in 0.1moldm−3 H2SO4 with and without additives. With no additives, compressive stress generally developed initially and films subsequently underwent a compressive-to-tensile (C-T) transition. With increasing negative potential, the time for the C-T transition decreased rapidly as the rate of coalescence of nuclei (measured by AFM) increased rapidly. This is consistent with models that attribute the C-T transition to increasing tensile stress due to coalescence of nuclei. Furthermore, at a potential of −75mV (Cu∕Cu2+), where AFM showed very little coalescence of nuclei, no C-T transition was observed, again consistent with these models. The nucleation density measured by AFM increased from 2.7×107cm−2 at −75mVto2.5×109cm−2 at −300mV. Stress measurements with a combination of three additives [1×10−3moldm−3 Cl−, 8.82×10−5moldm−3 polyethylene glycol, and 1×10−5moldm−3 3-mercapto-1-propanesulfonic acid sodium salt (MPSA)] also showed that compressive stress generally developed initially and its magnitude was greater than in additive-free electrolyte. At less negative potentials, even though the rate of coalescence of nuclei was rapid, as observed by AFM, the stress continued to evolve in the compressive direction. At intermediate potentials (−90to−150mV), classical compressive-tensile-compressive (C-T-C) behavior was observed, while at more negative potentials the stress continued to evolve in the tensile direction. Similar results were obtained with a combination of two additives (1×10−3moldm−3 Cl− and 1×10−5moldm−3 MPSA), but in that case the compressive stress appeared to be greater, and consequently the T-C transition was observed even at −500mV. The results are consistent with enhancement of a compressive component of stress in the presence of additives.
Influences of template layer thickness on strain fields and transition energies in self-assembled SiGe∕Si quantum dots
Authors: Kuo M. K. , Lin T. R. , Hong K. B.
Published: April 2008

This paper investigates the influence of thickness of template layer on strain fields and transition energies in lens-shaped self-assembled SiGe∕Si quantum dots. This study analyzes strain fields in and around quantum dots on the basis of the theory of linear elasticity. Strain fields are then incorporated into the steady-state effective-mass Schrödinger equation. Energy levels and wavefunctions of both electrons and holes are calculated. The calculated results of strain-induced phonon frequency are consistent with previous results obtained by Raman spectroscopy. Moreover, the calculated transition energy agrees well with previous experimental photoluminescence data. Numerical results also suggest that transition energy decreases as the template layer thickness increases.
Approximate analytical solutions for continuously focused beams and single-species plasmas in thermal equilibrium
Authors: Startsev Edward A. , Lund Steven M.
Published: April 2008

Simple, two-dimensional Vlasov–Poisson descriptions of thermal equilibrium have been applied to both an unbunched ion beam propagating in a continuous linear focusing channel and an unneutralized, single-species plasma confined in a Penning–Malmberg trap geometry. In scaled variables, these two thermal equilibrium systems result in an identical nonlinear equation that must be solved to describe the radial density and/or potential of the equilibrium. Numerous publications have been based on numerical solutions of the highly nonlinear equilibrium equation. Following a brief review of the thermal equilibrium model, we construct approximate, closed-form analytical solutions to the equilibrium equation that are accurate over a wide range of system parameters.
Controlling electromagnetic waves using tunable gradient dielectric metamaterial lens
Authors: Lin Xian Qi , Cui Tie Jun , Chin Jessie Yao , Yang Xin Mi , Cheng Qiang , Liu Ruopeng
Published: April 2008

We propose a metamaterial particle which is composed of a dielectric block with a thin metallic rod screwed inside. By adjusting the height of rod inside the dielectric block, we can control the effective medium parameters of a periodic structure composed of the particles. An experiment is presented to retrieve the effective medium parameters, which have good agreements with those from simulation results. Using the unique property of the tunable particles, gradient metamaterial lenses are easily designed to deflect and focus the incident plane waves.
Exciton diffusion length in the organic semiconductor diindenoperylene
Authors: Kurrle D. , Pflaum J.
Published: April 2008

The photovoltaic behavior of Schottky barrier devices consisting of a single diindenoperylene (DIP) layer sandwiched between an indium tin oxide and Ag electrode has been investigated. Correlating the spectral dependence of the photocurrent and the absorption coefficient, we estimated the exciton diffusion length in DIP to ∼100nm along the c′ direction. X-ray structural analysis yielded this length to be in agreement with the average crystallite size, thereby, revealing domain boundaries to be the limiting effect on the exciton transport. The corresponding exciton diffusion constant of 5×10−3cm2∕s resembles that of highly ordered single crystals of polyaromatic hydrocarbons.
Microwave air breakdown enhanced with metallic initiators
Authors: Herring G. C. , Popović S.
Published: April 2008

We have determined X-band (9.4GHz) electric field strengths required to obtain air breakdown at atmospheric pressure in the presence of metallic initiators, which are irradiated with repetitive (30pulses∕s) microwave pulses of 3μs duration and 200kW peak power. Using a half-wavelength initiator, a factor of 40 reduction (compared to no initiator) was observed in the electric field required to achieve breakdown. The present measurements are compared to a previously published model for air breakdown, which was originally validated with S-band (3GHz) frequencies and single 40μs pulses. We find good agreement between this previous model and our present measurements of breakdown with X-band frequencies and repetitive 3μs pulses.
Segmented nanowires of HgTe and Te grown by molecular beam epitaxy
Authors: Haakenaasen R. , Selvig E. , Foss S. , Trosdahl-Iversen L. , Taftø J.
Published: April 2008

Heterostructured nanowires consisting of alternating segments of HgTe and Te have been grown by molecular beam epitaxy. The cubic ⟨111⟩HgTe and the hexagonal ⟨001⟩Te directions are oriented along the wire. The 15–70nm wide, 0.5–1.5μm long wires are nucleated at Au particles and grow laterally on Si substrates, but they are not epitaxially coupled to the substrates. An excess of Te relative to Hg during growth could explain the segmentation, as the bulk phase diagram then allows only HgTe and elemental Te. Alternating between these two phases is facilitated by the epitaxial match between the HgTe and Te segments.
Comment on “Barut–Girardello and Klauder–Perelomov coherent states for the Kravchuk functions” [J. Math. Phys. 48, 112106 (2007)]
Authors: Fakhri H. , Dehghani A.
Published: April 2008

We call attention to the misconstructions in a paper recently published in this journal [A. Chenaghlou and O. Faizy, J. Math. Phys. 48, 112106 (2007)]. It is shown that the constructed Barut–Girardello coherent states are problematic from the view points of the definition and the measure. The claimed coherencies for the Kravchuk functions cannot actually exist.
Ordering layers of [bmim][PF6] ionic liquid on graphite surfaces: Molecular dynamics simulation
Authors: Maolin Sha , Fuchun Zhang , Guozhong Wu , Haiping Fang , Chunlei Wang , Shimou Chen , Yi Zhang , Jun Hu
Published: April 2008

Microscopic structures of room temperature ionic liquid (IL) [bmim][PF6] on hydrophobic graphite surfaces have been studied in detail by molecular dynamics simulation. It is clearly shown that both the mass and electron densities of the surface adsorbed ionic liquid are oscillatory, and the first peak adjacent to the graphite surface is considerably higher than others, corresponding to a solidlike IL bottom layer of 6Å thick. Three IL layers are indicated between the graphite surface and the inner bulk IL liquid. The individually simulated properties of single-, double-, and triple-IL layers on the graphite surface are very similar to those of the layers between the graphite surface and the bulk liquid, indicating an insignificant effect of vapor-IL interface on the ordered IL layers. The simulation also indicates that the imidazolium ring and butyl tail of the cation (bmim+) of the IL bottom layer lie flat on the graphite surface.
Scaling of mixed structure functions in turbulent boundary layers
Authors: Jacob Boris , Casciola Carlo Massimo , Talamelli Alessandro , Alfredsson P. Henrik
Published: April 2008

We address the issue of the scaling of the anisotropic components of the hierarchy of correlation tensors in the logarithmic region of a turbulent boundary layer over a flat plate, at Reθ≈15000. We isolate the anisotropic observables by means of decomposition tools based on the SO(3) symmetry group of rotations. By employing a dataset made of velocity signals detected by two X probes, we demonstrate that the behavior of the anisotropic fluctuations throughout the boundary layer may be understood in terms of the superposition of two distinct regimes. The transition is controlled by the magnitude of the mean shear and occurs in correspondence with the shear scale. Below the shear scale, an isotropy-recovering behavior occurs, which is characterized by a set of universal exponents which roughly match dimensional predictions based on Lumley’s argument [J. L. Lumley, Phys. Fluids 8, 1056 (1965)]. Above the shear scale, the competition between energy production and transfer mechanisms gives rise to a completely different scenario with strong alterations of the observed scaling laws. This aspect has significant implications for the correct parametrization of the anisotropy behavior in the near wall region since, approaching the wall, an increasingly larger fraction of the scaling interval tends to conform to the shear-dominated power laws.
Two-surface Monte Carlo with basin hopping: Quantum mechanical trajectory and multiple stationary points of water cluster
Authors: Bandyopadhyay Pradipta
Published: April 2008

The efficiency of the two-surface monte carlo (TSMC) method depends on the closeness of the actual potential and the biasing potential used to propagate the system of interest. In this work, it is shown that by combining the basin hopping method with TSMC, the efficiency of the method can be increased by several folds. TSMC with basin hopping is used to generate quantum mechanical trajectory and large number of stationary points of water clusters.