bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute and long-term effects of grape and pomegranate juice consumption on vascular reactivity in paediatric metabolic syndrome
Authors: Hashemi Mohammad , Kelishadi Roya , Hashemipour Mahin , Zakerameli Afshin , Khavarian Noushin , Ghatrehsamani Shohreh , Poursafa Parinaz
Published: February 2010

Objectives

This study, which to the best of our knowledge is the first of its kind, aimed to determine the acute and long-term effects of the consumption of grape and pomegranate juices on endothelium function in adolescents with metabolic syndrome, and to compare the effects of these two kinds of juices.

Methods

This randomised controlled clinical trial was conducted in 2008 among 30 adolescents, aged 12–15 years, with metabolic syndrome. Participants were randomly assigned to two groups of equal number; one group was asked to drink 18 millilitre per kilogram per day of natural grape juice and the other group was asked to drink 240 millilitre per day of natural pomegranate juice once daily for 1 month. Juices were homemade without any added sweetener. Basal brachial artery dimension and flow-mediated dilation as an index of endothelial function and endothelial-dependent dilation after receiving nitoglycerin spray were evaluated by high-resolution B mode ultrasonography before juice consumption, 4 hours and 30 days after regular daily consumption.

Results

Flow-mediated dilation at 90 seconds and after nitoglycerin significantly improved at 4 hours and at 1 month after drinking both kinds of juices, without significant difference between the two groups. The change at 1 month versus 4 hours was significant only in the grape juice group.

Conclusion

Daily consumption of diets rich in antioxidants might improve endothelial function in adolescents with metabolic syndrome. These effects began as soon as 4 hours after juice consumption. Such beneficial effects should be considered in dietary recommendations for the paediatric age group, notably in obese individuals.
Profiles of functional deficits in mild cognitive impairment and dementia: benefits from objective measurement
Authors: PEREIRA FERNANDA SPEGGIORIN , YASSUDA MÔNICA SANCHES , OLIVEIRA ALEXANDRA MARTINI , DINIZ BRENO SATLER , RADANOVIC MÁRCIA , TALIB LEDA LEME , GATTAZ WAGNER FARID , FORLENZA ORESTES VICENTE
Published: February 2010

The magnitude of functional impairment that may indicate the threshold between MCI and incipient Alzheimer’s disease (AD) has not been clearly defined. The objective was to examine the pattern of functional impairment in the continuum MCI-AD. Eighty-nine older adults (32 cognitively unimpaired, 31 MCI, and 26 AD patients) were examined with the Brazilian version of the Direct Assessment of Functional Status (DAFS-BR) at a university-based memory clinic. MCI patients were sub-divided according to the progression to AD upon follow-up, and had baseline cognitive, functional and biological variables analyzed. MCI patients displayed mild deficits in functional abilities, with intermediate scores as compared to controls and AD. The DAFS-BR items that differentiated MCI from controls involved the ability to deal with finances and shopping skills. At baseline, scores obtained by MCI patients who converted to AD were not significantly different from scores of nonconverters. The magnitude of functional deficits was associated with AD-like pathological findings in the CSF. In conclusion, MCI patients present with early functional changes in complex, instrumental abilities that require the integrity of memory and executive functions. The objective measurement of the functional state may help identify older adults with increased risk of developing dementia in the MCI-AD continuum. (JINS, 2010, 16, 297–305.)
Learning and memory in amnestic mild cognitive impairment: Contribution of working memory
Authors: PRICE SARAH E. , KINSELLA GLYNDA J. , ONG BEN , MULLALY ELIZABETH , PHILLIPS MARGARET , PANGNADASA-FOX LANKI , PERRE DIANA , STOREY ELSDON
Published: February 2010

In addition to deficits in delayed recall, recent research suggests that participants with amnestic mild cognitive impairment (aMCI) demonstrate diminished use of strategic encoding strategies during learning. Few studies have explored the cognitive mechanisms underlying this deficit. The aim of this study was to investigate in aMCI whether components of working memory (executive attention – attention set-shifting, dividing and focusing attention; and episodic buffer functions – strategic retrieval and manipulation of information) predict strategic encoding strategies during learning (semantic clustering). Thirty-three participants with aMCI and 33 healthy older adults (HOA) were administered neuropsychological tests assessing word-list learning and working memory. The aMCI group demonstrated significant impairment in acquisition, retrieval of information, and decreased use of semantic clustering strategies. Use of semantic clustering in the aMCI group was not predicted by measures of executive attention or phonemic verbal fluency, but was predicted by semantic verbal fluency performance. In the HOA group, semantic clustering was strongly related to semantic verbal fluency. These findings suggest that in aMCI, diminished strategic encoding strategies during learning (semantic clustering) is selectively related to the strategic function of the episodic buffer, but only when in interaction with the manipulation and retrieval of semantic associations. (JINS, 2010, 16, 342–351.)
The Emergence of Two First-Person Plural Pronouns in Haredi Jerusalemite Yiddish
Authors: Assouline Dalit
Published: February 2010

This paper demonstrates the rise of a new distinction in the first-person plural pronouns in Jerusalemite Yiddish, a contemporary dialect of Yiddish spoken in Israel by ultra-orthodox (Haredi) Jews. The distinction is semantically-pragmatically motivated, where a particular pronoun is used to refer to a specific subgroup of “us” compared with “them.” This innovation evolved as a result of both dialect contact and of the special sociolinguistic characteristics of the Haredi community in Israel. A rare phenomenon in the languages of the world, it reflects the unique self-imposed seclusion that is the social reality of speakers of Haredi Yiddish.*
Yiddish Proto-Vowels and German Dialects
Authors: Beider Alexander
Published: February 2010

This paper suggests a series of schemas aimed at eliminating the main drawbacks of existing schemas of Yiddish proto-vowels. It attempts to complete the schemas developed by other scholars mainly in two aspects, proposing derivational rules that (1) account for Proto-Western Yiddish and its sub-dialects and (2) explain the relation between the vowels of the German donor language and Yiddish proto-vowels. This analysis shows the impossibility of constructing a schema of a single Proto-Yiddish as a historical reality and thus implies the polygenesis of the system of stressed vowels and diphthongs of Yiddish. Proto-Western Yiddish and Proto-Eastern Yiddish had no common, specifically Jewish ancestor. The comparative analysis of various German dialects and Yiddish proposed here provides the basis for determining the regions (East Franconia and Bohemia, respectively) where the stressed vocalism of the Yiddish dialects likely appeared and the corresponding time period (the 14th–15th centuries).
Maternal copper deficiency perpetuates altered vascular function in Sprague-Dawley rat offspring
Authors: Anderson C. M. , Johnson W. T.
Published: February 2010

Little is known about the consequences of maternal copper (Cu) deficiency on the vascular function of offspring or on perpetuation of vascular effects to a second generation. We examined vascular functional responses in mesenteric arteries from Cu-deficient Sprague-Dawley rat dams and from offspring directly exposed to maternal Cu deficiency during development and lactation and perpetuation of the effects in a second generation of offspring. Dams were fed a diet with marginal (1 mg Cu/kg) or adequate (6 mg Cu/kg) Cu for 3 weeks before conception and throughout pregnancy and lactation periods. Half of the first generation (F1) litters were cross-fostered. At reproductive maturity, F1 pairs were bred within groups resulting in second generation (F2) offspring. At 9 weeks of age, mesenteric artery (200 μm) isometric tension was determined in response to vasoconstrictors and vasorelaxants using a small artery wire myograph. Cu deficiency did not alter the vascular function in dams. In F1 offspring, increased responsiveness to potassium chloride in male offspring was due to direct exposure to maternal Cu deficiency in the birth mother, while enhanced endothelium-dependent relaxation responses in female offspring resulted from postnatal exposure to maternal Cu deficiency. Increased endothelium independent and decreased endothelium-dependent relaxation responses were identified in F2 Cu-deficient male offspring. These data indicate that exposure to maternal Cu deficiency during critical windows of development alter the vascular function across two generations of offspring.
A northward shift of the North Atlantic Ocean Intertropical Convergence Zone in response to summertime Saharan dust outbreaks
Authors: Wilcox Eric M. , Lau K. M. , Kim Kyu‐Myong
Published: February 2010

The influence on the summertime North Atlantic Ocean inter‐tropical convergence zone (ITCZ) of Saharan dust outbreaks is explored using nine years of continuous satellite observations and atmospheric reanalysis products. During dust outbreak events rainfall along the ITCZ shifts northward by 1 to 4 degrees latitude. Dust outbreaks coincide with warmer lower‐tropospheric temperatures compared to low dust conditions, which is attributable to advection of the warm Saharan Air Layer, enhanced subtropical subsidence, and radiative heating of dust. The enhanced positive meridional temperature gradient coincident with dust outbreaks is accompanied by an acceleration of the easterly winds on the north side of the African Easterly Jet (AEJ). The center of the positive vorticity region south of the AEJ moves north drawing the center of low‐level convergence and ITCZ rainfall northward with it. The enhanced precipitation on the north side of the ITCZ occurs in spite of widespread sea surface temperature cooling north of the ITCZ owing to reduced surface solar insolation by dust scattering.
Simultaneous Estimation of Input Functions: An Empirical Study
Authors: Ogden R Todd , Zanderigo Francesca , Choy Stephen , Mann J John , Parsey Ramin V
Published: February 2010

In neuroreceptor mapping, methods for the estimation of distribution volume require determination of a metabolite-corrected arterial input function. In application, this may be accomplished by collecting arterial blood samples during scanning, adjusting these measurements according to a separate metabolite analysis, and then modeling the resulting concentration data. Although many groups do this routinely, it is invasive and requires considerable effort. Furthermore, both the plasma and the metabolite data are noisy, and thus estimation of kinetic parameters can be affected by this variability. One promising alternative to full-input function modeling is the simultaneous estimation (SIME) approach, in which kinetic parameters and common input function parameters are estimated using results obtained from several regions at once. We investigate the performance of this approach on data from four different radioligands, using various kinetic models, comparing the results with those obtained by estimation using full-input function modeling. Results indicate that SIME provides a promising alternative for all the radioligands considered.
Effects of AMP-Activated Protein Kinase in Cerebral Ischemia
Authors: Li Jun , McCullough Louise D
Published: February 2010

AMP-activated protein kinase (AMPK) is a serine threonine kinase that is highly conserved through evolution. AMPK is found in most mammalian tissues including the brain. As a key metabolic and stress sensor/effector, AMPK is activated under conditions of nutrient deprivation, vigorous exercise, or heat shock. However, it is becoming increasingly recognized that changes in AMPK activation not only signal unmet metabolic needs, but also are involved in sensing and responding to ‘cell stress’, including ischemia. The downstream effect of AMPK activation is dependent on many factors, including the severity of the stressor as well as the tissue examined. This review discusses recent in vitro and in vivo studies performed in the brain/neuronal cells and vasculature that have contributed to our understanding of AMPK in stroke. Recent data on the potential role of AMPK in angiogenesis and neurogenesis and the interaction of AMPK with 3-hydroxy-3-methy-glutaryl-CoA reductase inhibitors (statins) agents are highlighted. The interaction between AMPK and nitric oxide signaling is also discussed.
Inhibition of Reactive Astrocytes with Fluorocitrate Retards Neurovascular Remodeling and Recovery after Focal Cerebral Ischemia in Mice
Authors: Hayakawa Kazuhide , Nakano Takafumi , Irie Keiichi , Higuchi Sei , Fujioka Masayuki , Orito Kensuke , Iwasaki Katsunori , Jin Guang , Lo Eng H , Mishima Kenichi , Fujiwara Michihiro
Published: February 2010

Glial scarring is traditionally thought to be detrimental after stroke. But emerging studies now suggest that reactive astrocytes may also contribute to neurovascular remodeling. Here, we assessed the effects and mechanisms of metabolic inhibition of reactive astrocytes in a mouse model of stroke recovery. Five days after stroke onset, astrocytes were metabolically inhibited with fluorocitrate (FC, 1 nmol). Markers of reactive astrocytes (glial fibrillary acidic protein (GFAP), HMGB1), markers of neurovascular remodeling (CD31, synaptophysin, PSD95), and behavioral outcomes (neuroscore, rotarod latency) were quantified from 1 to 14 days. As expected, focal cerebral ischemia induced significant neurological deficits in mice. But over the course of 14 days after stroke onset, a steady improvement in neuroscore and rotarod latencies were observed as the mice spontaneously recovered. Reactive astrocytes coexpressing GFAP and HMGB1 increased in peri-infarct cortex from 1 to 14 days after cerebral ischemia in parallel with an increase in the neurovascular remodeling markers CD31, synaptophysin, and PSD95. Compared with stroke-only controls, FC-treated mice demonstrated a significant decrease in HMGB1-positive reactive astrocytes and neurovascular remodeling, as well as a corresponding worsening of behavioral recovery. Our results suggest that reactive astrocytes in peri-infarct cortex may promote neurovascular remodeling, and these glial responses may aid functional recovery after stroke.
Acute-Stage Diffusion-Weighted Magnetic Resonance Imaging for Predicting Outcome of Poor-Grade Aneurysmal Subarachnoid Hemorrhage
Authors: Sato Kenichi , Shimizu Hiroaki , Fujimura Miki , Inoue Takashi , Matsumoto Yasushi , Tominaga Teiji
Published: February 2010

We investigated the role of acute-stage diffusion-weighted images (DWIs) for predicting outcome of poor-grade subarachnoid hemorrhage (SAH). This study included 38 patients with poor-grade SAH who underwent DWI within 24 h after onset. DWI findings were divided into three groups on the basis of lesion area: none (N), spotty (S, ≦10 mm2), or areal (A, >10 mm2). We evaluated the correlation between preoperative DWI findings and clinical outcome, and the characteristics of DWI abnormalities. DWI abnormalities were revealed in 81.6% of cases (group S 34.2%; group A 47.3%). All patients in groups N and S and 73.3% of patients in group A were treated radically. For those patients without rerupture, favorable outcomes were achieved in 100% of group N, 53.8% of group S, and 0% of group A. Abnormal lesions on initial DWI, which resulted in permanent lesions, showed a mean apparent diffusion coefficient ratio to the control value of 0.71, which was significantly lower than 0.95 observed in reversible lesions ( P<0.01). We recommend radical treatment for even poor-grade SAH as long as the preoperative DWI shows no or only spotty lesions. DWI may provide an objective means to estimate the outcome of poor-grade SAH.
Assessment of Regional Differences in Tariquidar-Induced P-Glycoprotein Modulation at the Human Blood–Brain Barrier
Authors: Bauer Martin , Karch Rudolf , Neumann Friederike , Wagner Claudia C , Kletter Kurt , Müller Markus , Löscher Wolfgang , Zeitlinger Markus , Langer Oliver
Published: February 2010

We attempted to assess regional differences in cerebral P-glycoprotein (P-gp) function by performing paired positron emission tomography (PET) scans with the P-gp substrate ( R)-[11C]verapamil in five healthy subjects before and after i.v. infusion of tariquidar (2 mg/kg). Comparison of tariquidar-induced changes in distribution volumes ( DVs) in 42 brain regions of interest (ROIs) failed to detect significant differences among brain ROIs. Statistical parametric mapping analysis of parametric DV images visualized symmetrical bilateral clusters with moderately higher DV increases in response to tariquidar administration in cerebellum, parahippocampal gyrus, olfactory gyrus, and middle temporal lobe and cortex, which might reflect moderately decreased P-gp function and expression.
Statistics in Experimental Cerebrovascular Research—Comparison of Two Groups with a Continuous Outcome Variable
Authors: Schlattmann Peter , Dirnagl Ulrich
Published: February 2010

Part one of this mini-series on statistics in cerebrovascular research uses the simplest yet most common comparison in experimental research (two groups with a continuous outcome variable) to introduce the very basic concepts of statistical testing: a priori formulation of hypotheses and definition of planned statistical analysis, error considerations, and power analysis.
A Novel Inhibitor of Plasminogen Activator Inhibitor-1 Provides Antithrombotic Benefits Devoid of Bleeding Effect in Nonhuman Primates
Authors: Izuhara Yuko , Yamaoka Nagahisa , Kodama Hidehiko , Dan Takashi , Takizawa Shunya , Hirayama Noriaki , Meguro Kanji , van Ypersele de Strihou Charles , Miyata Toshio
Published: February 2010

Inhibition of plasminogen activator inhibitor (PAI)-1 is useful to treat several disorders including thrombosis. An inhibitor of PAI-1 (TM5275) was newly identified by an extensive study of structure-activity relationship based on a lead compound (TM5007) which was obtained through virtual screening by docking simulations. Its antithrombotic efficacy and adverse effects were tested in vivo in rats and nonhuman primates (cynomolgus monkey). TM5275, administered orally in rats (1 to 10 mg/kg), has an antithrombotic effect equivalent to that of ticlopidine (500 mg/kg) in an arterialvenous shunt thrombosis model and to that of clopidogrel (3 mg/kg) in a ferric chloride-treated carotid artery thrombosis model. TM5275 does not modify activated partial thromboplastin time and prothrombin time or platelet activity and does not prolong bleeding time. Combined with tissue plasminogen activator, TM5275 improves the latter's therapeutic efficacy and reduces its adverse effect. Administered to a monkey model of photochemical induced arterial thrombosis, TM5275 (10 mg/kg) has the same antithrombotic effect as clopidogrel (10 mg/kg), without enhanced bleeding. This study documents the antithrombotic benefits of a novel, more powerful, PAI-1 inhibitor in rats and, for the first time, in nonhuman primates. These effects are obtained without adverse effect on bleeding time.
Xenon is an Inhibitor of Tissue-Plasminogen Activator: Adverse and Beneficial Effects in a Rat Model of Thromboembolic Stroke
Authors: David Hélène N , Haelewyn Benoît , Risso Jean-Jacques , Colloc'h Nathalie , Abraini Jacques H
Published: February 2010

Preclinical evidence in rodents has proven that xenon may be a very promising neuroprotective agent for treating acute ischemic stroke. This has led to the general thinking that clinical trials with xenon could be initiated in acute stroke patients in a next future. However, an unappreciated physicochemical property of xenon has been that this gas also binds to the active site of a series of serine proteases. Because the active site of serine proteases is structurally conserved, we have hypothesized and investigated whether xenon may alter the catalytic efficiency of tissue-type plasminogen activator (tPA), a serine protease that is the only approved therapy for acute ischemic stroke today. Here, using molecular modeling and in vitro and in vivo studies, we show (1) xenon is a tPA inhibitor; (2) intraischemic xenon dose dependently inhibits tPA-induced thrombolysis and subsequent reduction of ischemic brain damage; (3) postischemic xenon virtually suppresses ischemic brain damage and tPA-induced brain hemorrhages and disruption of the blood–brain barrier. Taken together, these data indicate (1) xenon should not be administered before or together with tPA therapy; (2) xenon could be a golden standard for treating acute ischemic stroke if given after tPA-induced reperfusion, with both unique neuroprotective and antiproteolytic (anti-hemorrhaging) properties.
Absence of the αvβ3 Integrin Dictates the Time-Course of Angiogenesis in the Hypoxic Central Nervous System: Accelerated Endothelial Proliferation Correlates with Compensatory Increases in α5β1 Integrin Expression
Authors: Li Longxuan , Welser Jennifer V , Milner Richard
Published: February 2010

Cerebral angiogenesis is an important adaptive response to hypoxia. As the αvβ3 integrin is induced on angiogenic vessels in the ischemic central nervous system (CNS), and the suggested angiogenic role for this integrin in other systems, it is important to determine whether the αvβ3 integrin is an important mediator of cerebral angiogenesis. αvβ3 integrin expression was examined in a model of cerebral hypoxia, in which mice were subject to hypoxia (8% O2) for 0, 4, 7, or 14 days. Immunofluorescence and western blot analysis revealed that in the hypoxic CNS, αvβ3 integrin was strongly induced on angiogenic brain endothelial cells (BEC), along with its ligand vitronectin. In the hypoxia model, β3 integrin-null mice showed no obvious defect in cerebral angiogenesis. However, early in the angiogenic process, BEC in these mice showed an increased mitotic index that correlated closely with increased α5 integrin expression. In vitro experiments confirmed α5 integrin upregulation on β3 integrin-null BEC, which also correlated with increased BEC proliferation on fibronectin. These studies confirm hypoxic induction of αvβ3 integrin on angiogenic vessels, but suggest distinct roles for the BEC integrins αvβ3 and α5β1 in cerebral angiogenesis, with αvβ3 having a nonessential role, and α5β1 promoting BEC proliferation.
Ascorbic Acid Prevents Blood–Brain Barrier Disruption and Sensory Deficit Caused by Sustained Compression of Primary Somatosensory Cortex
Authors: Lin Jia-Li , Huang Yung-Hsin , Shen Yi-Ching , Huang Hsuan-Chi , Liu Pei-Hsin
Published: February 2010

Transient compression of rat somatosensory cortex has been reported to affect cerebral microvasculature and sensory function simultaneously. However, the effects of long-term cortical compression remain unknown. Here, we investigated whether and to what extent sustained but moderate epidural compression of rat somatosensory cortex impairs somatic sensation and/or cortical microvasculature. Electrophysiological and behavioral tests revealed that sustained compression caused only short-term sensory deficit, particularly at 1 day after injury. Although the diameter of cortical microvessels was coincidentally reduced, no ischemic insult was observed. By measuring Evans Blue and immunoglobulin G extravasation, the blood–brain barrier (BBB) permeability was found to dramatically increase during 1 to 3 days, but this did not lead to brain edema. Furthermore, immunoblotting showed that the BBB component proteins occludin, claudin-5, type IV collagen, and glial fibrillary acidic protein were markedly upregulated in the injured cortex during 1 to 2 weeks when BBB regained integrity. Conversely, treatment of ascorbic acid prevented compression-induced BBB disruption and sensory impairment. Together, these data suggest that sustained compression of the somatosensory cortex compromises BBB integrity and somatic sensation only in the early period. Ascorbic acid may be used therapeutically to modulate cortical compression and/or BBB dysfunction.
Genetic Determinants of Cerebral Vasospasm, Delayed Cerebral Ischemia, and Outcome after Aneurysmal Subarachnoid Hemorrhage
Authors: Ducruet Andrew F , Gigante Paul R , Hickman Zachary L , Zacharia Brad E , Arias Eric J , Grobelny Bartosz T , Gorski Justin W , Mayer Stephan A , Connolly E Sander
Published: February 2010

Despite extensive effort to elucidate the cellular and molecular bases for delayed cerebral injury after aneurysmal subarachnoid hemorrhage (aSAH), the pathophysiology of these events remains poorly understood. Recently, much work has focused on evaluating the genetic underpinnings of various diseases in an effort to delineate the contribution of specific molecular pathways as well as to uncover novel mechanisms. The majority of subarachnoid hemorrhage genetic research has focused on gene expression and linkage studies of these markers as they relate to the development of intracranial aneurysms and their subsequent rupture. Far less work has centered on the genetic determinants of cerebral vasospasm, the predisposition to delayed cerebral injury, and the determinants of ensuing functional outcome after aSAH. The suspected genes are diverse and encompass multiple functional systems including fibrinolysis, inflammation, vascular reactivity, and neuronal repair. To this end, we present a systematic review of 21 studies suggesting a genetic basis for clinical outcome after aSAH, with a special emphasis on the pathogenesis of cerebral vasospasm and delayed cerebral ischemia. In addition, we highlight potential pitfalls in the interpretation of genetic association studies, and call for uniformity of design of larger multicenter studies in the future.
Increased Nuclear Apoptosis-Inducing Factor after Transient Focal Ischemia: A 12/15-Lipoxygenase-dependent Organelle Damage Pathway
Authors: Pallast Stefanie , Arai Ken , Pekcec Anton , Yigitkanli Kazim , Yu Zhanyang , Wang Xiaoying , Lo Eng H , van Leyen Klaus
Published: February 2010

12/15-lipoxygenase (12/15-LOX) contributes to acute neuronal injury and edema formation in mouse models of middle cerebral artery occlusion (MCAO). The apoptosis-inducing factor (AIF) is implicated in caspase-independent forms of apoptosis, and has been linked to ischemic neuronal cell death. We show here that increased AIF in the peri-ischemic cortex of mouse colocalizes with 12/15-LOX after 2 h of MCAO. The 12/15-LOX inhibitor baicalein prevents the increase and nuclear localization of AIF, suggesting this pathway may be partially responsible for the neuroprotective qualities of baicalein. Using an established cell line model of neuronal oxidative stress, we show that 12/15-LOX activated after glutathione depletion leads to AIF translocation to the nucleus, which is abrogated by the 12/15-LOX inhibitor baicalein (control: 19.3%±6.8% versus Glutamate: 64.0%±8.2% versus glutamate plus baicalein: 11.4%±2.2%). Concomitantly, resident proteins of the ER are dispersed throughout the cell (control: 31.0%±8.4% versus glutamate: 70.0%±5.5% versus glutamate plus baicalein: 8.0%±2.7%), suggesting cell death through organelle damage. Taken together, these findings show that 12/15-LOX and AIF are sequential actors in a common cell death pathway that may contribute to stroke-induced brain damage.
Molecular Magnetic Resonance Imaging of Acute Vascular Cell Adhesion Molecule-1 Expression in a Mouse Model of Cerebral Ischemia
Authors: Hoyte Lisa C , Brooks Keith J , Nagel Simon , Akhtar Asim , Chen Ruoli , Mardiguian Sylvie , McAteer Martina A , Anthony Daniel C , Choudhury Robin P , Buchan Alastair M , Sibson Nicola R
Published: February 2010

The pathogenesis of stroke is multifactorial, and inflammation is thought to have a critical function in lesion progression at early time points. Detection of inflammatory processes associated with cerebral ischemia would be greatly beneficial in both designing individual therapeutic strategies and monitoring outcome. We have recently developed a new approach to imaging components of the inflammatory response, namely endovascular adhesion molecule expression on the brain endothelium. In this study, we show specific imaging of vascular cell adhesion molecule (VCAM)-1 expression in a mouse model of middle cerebral artery occlusion (MCAO), and a reduction in this inflammatory response, associated with improved behavioral outcome, as a result of preconditioning. The spatial extent of VCAM-1 expression is considerably greater than the detectable lesion using diffusion-weighted imaging (25% versus 3% total brain volume), which is generally taken to reflect the core of the lesion at early time points. Thus, VCAM-1 imaging seems to reveal both core and penumbral regions, and our data implicate VCAM-1 upregulation and associated inflammatory processes in the progression of penumbral tissue to infarction. Our findings indicate that such molecular magnetic resonance imaging (MRI) approaches could be important clinical tools for patient evaluation, acute monitoring of therapy, and design of specific treatment strategies.
Mechanisms Contributing to Cerebral Infarct Size after Stroke: Gender, Reperfusion, T Lymphocytes, and Nox2-Derived Superoxide
Authors: Brait Vanessa H , Jackman Katherine A , Walduck Anna K , Selemidis Stavros , Diep Henry , Mast Anja E , Guida Elizabeth , Broughton Brad RS , Drummond Grant R , Sobey Christopher G
Published: February 2010

Cerebral infarct volume is typically smaller in premenopausal females than in age-matched males after ischemic stroke, but the underlying mechanisms are poorly understood. In this study we provide evidence in mice that this gender difference only occurs when the ischemic brain is reperfused. The limited tissue salvage achieved by reperfusion in male mice is associated with increased expression of proinflammatory proteins, including cyclooxygenase-2 (Cox-2), Nox2, and vascular cell adhesion molecule-1 (VCAM-1), and infiltration of Nox2-containing T lymphocytes into the infarcted brain, whereas such changes are minimal in female mice after ischemia–reperfusion (I-R). Infarct volume after I-R was no greater at 72 h than at 24 h in either gender. Infarct development was Nox2 dependent in male but not in female mice, and Nox2 within the infarct was predominantly localized in T lymphocytes. Stroke resulted in an ∼15-fold increase in Nox2-dependent superoxide production by circulating, but not spleen-derived, T lymphocytes in male mice, and this was ∼sevenfold greater than in female mice. These circulating immune cells may thus represent a major and previously unrecognized source of superoxide in the acutely ischemic and reperfused brain of males (and potentially in postmenopausal females). Our findings provide novel insights into mechanisms that could be therapeutically targeted in acute ischemic stroke patients who receive thrombolysis therapy to induce cerebral reperfusion.
Evaluation of Cerebral Acetate Transport and Metabolic Rates in the Rat Brainin vivoUsing1H-[13C]-NMR
Authors: Patel Anant B , de Graaf Robin A , Rothman Douglas L , Behar Kevin L , Mason Graeme F
Published: February 2010

Acetate is a well-known astrocyte-specific substrate that has been used extensively to probe astrocytic function in vitro and in vivo. Analysis of amino acid turnover curves from13C-acetate has been limited mainly for estimation of first-order rate constants from exponential fitting or calculation of relative rates from steady-state13C enrichments. In this study, we used1H-[13C]-Nuclear Magnetic Resonance spectroscopy with intravenous infusion of [2-13C]acetate-Na+in vivo to measure the cerebral kinetics of acetate transport and utilization in anesthetized rats. Kinetics were assessed using a two-compartment (neuron/astrocyte) analysis of the13C turnover curves of glutamate-C4 and glutamine-C4 from [2-13C]acetate-Na+, brain acetate levels, and the dependence of steady-state glutamine-C4 enrichment on blood acetate levels. The steady-state enrichment of glutamine-C4 increased with blood acetate concentration until 90% of plateau for plasma acetate of 4 to 5 mmol/L. Analysis assuming reversible, symmetric Michaelis–Menten kinetics for transport yielded 27±2mmol/L and 1.3±0.3 μmol/g/min for Ktand Tmax, respectively, and for utilization, 0.17±0.24 mmol/L and 0.14±0.02 μmol/g/min for KM_utiland Vmax_util, respectively. The distribution space for acetate was only 0.32±0.12 mL/g, indicative of a large excluded volume. The astrocytic and neuronal tricarboxylic acid cycle fluxes were 0.37±0.03 μmol/g/min and 1.41±0.11 μmol/g/min, respectively; astrocytes thus comprised ∼21%±3% of total oxidative metabolism.
Use of Magnetic Resonance Imaging to Predict Outcome after Stroke: A Review of Experimental and Clinical Evidence
Authors: Farr Tracy D , Wegener Susanne
Published: February 2010

Despite promising results in preclinical stroke research, translation of experimental data into clinical therapy has been difficult. One reason is the heterogeneity of the disease with outcomes ranging from complete recovery to continued decline. A successful treatment in one situation may be ineffective, or even harmful, in another. To overcome this, treatment must be tailored according to the individual based on identification of the risk of damage and estimation of potential recovery. Neuroimaging, particularly magnetic resonance imaging (MRI), could be the tool for a rapid comprehensive assessment in acute stroke with the potential to guide treatment decisions for a better clinical outcome. This review describes current MRI techniques used to characterize stroke in a preclinical research setting, as well as in the clinic. Furthermore, we will discuss current developments and the future potential of neuroimaging for stroke outcome prediction.
Oxygen-Sensitive Outcomes and Gene Expression in Acute Ischemic Stroke
Authors: Rink Cameron , Roy Sashwati , Khan Mahmood , Ananth Pavan , Kuppusamy Periannan , Sen Chandan K , Khanna Savita
Published: February 2010

Acute ischemic stroke (AIS) results in focal deprivation of blood-borne factors, one of them being oxygen. The purpose of this study was two-fold: (1) to identify therapeutic conditions for supplemental oxygen in AIS and (2) to use transcriptome-wide screening toward uncovering oxygen-sensitive mechanisms. Transient MCAO in rodents was used to delineate the therapeutic potential of normobaric (NBO, 100% O2, 1ATA) and hyperbaric oxygen (HBO, 100% O2, 2ATA) during ischemia (iNBO, iHBO) and after reperfusion (rNBO, rHBO). Stroke lesion was quantified using 4.7 T MRI at 48 h. Supplemental oxygen during AIS significantly attenuated percent stroke hemisphere lesion volume as compared with that in room air (RA) controls, whereas identical treatment immediately after reperfusion exacerbated lesion volume (RA=22.4±1.8, iNBO=9.9±3.6, iHBO=6.6±4.8, rNBO=29.8±3.6, rHBO=35.4±7.6). iNBO and iHBO corrected penumbra tissue pO2 during AIS as measured by EPR oxymetry. Unbiased query of oxygen-sensitive transcriptome in stroke-affected tissue identified 5,769 differentially expressed genes. Candidate genes were verified by real-time PCR using neurons laser-captured from the stroke-affected somatosensory cortex. Directed microarray analysis showed that supplemental oxygen limited leukocyte accumulation to the infarct site by attenuation of stroke-inducible proinflammatory chemokine response. The findings provide key information relevant to understanding oxygen-dependent molecular mechanisms in the AIS-affected brain.
Development of high efficiency Versatile Arc Discharge Ion Source at CERN ISOLDE
Authors: Penescu L. , Catherall R. , Lettry J. , Stora T.
Published: February 2010

We report here recent developments of Forced Electron Beam Induced Arc Discharge (FEBIAD) ion sources at the ISOLDE radioactive ion beam facility, hosted at the European Organization for Nuclear Research (CERN). As a result of the propositions to improve the ionization efficiency, two FEBIAD prototypes have been produced and successfully tested in 2008. Off-line studies showed that the 1+ ionization efficiencies for noble gases are 5–20 times larger than with the standard ISOLDE FEBIAD ion sources and reach 60% for radon, which allowed the identification at ISOLDE of R229n, an isotope that had never previously been observed in the laboratory. A factor of 3 increase is also expected for the ionization efficiency of the other elements. The experimental and theoretical methodology is presented. The theoretical model, which gives precise insights on the processes affecting the ionization, is used to design optimal sources (grouped under the name of VADIS—Versatile Arc Discharge Ion Source) for the different chemical classes of the produced isotopes, as already demonstrated for the noble gases.
On the measured current in electrospinning
Authors: Bhattacharjee P. K. , Schneider T. M. , Brenner M. P. , McKinley G. H. , Rutledge G. C.
Published: February 2010

The origin and scaling of the current measured during steady electrospinning of polymer solutions in organic solvents are considered. For a specified electric field strength E, flow rate Q, and conductivity K, the total measured current is shown empirically to scale as Itotal∼EQ0.5K0.4, for a wide variety of polymer solutions with different electrical conductivities. It is also shown that Itotal is composed of two distinct components: one that varies linearly with E, and another that is independent of E, but varies with the conductivity K of the fluid and the flow rate Q. The experimental evidence suggests that the latter component arises due to a secondary electrospray emanating from the surface of the jet. The consequence of this secondary electrospray mechanism on the final fiber size achieved during the electrospinning process is also discussed.
Investigation of fringe plasma parameters on a high power rf driven ion source
Authors: McNeely P. , Schiesko L.
Published: February 2010

It has been observed that there are differences between the uncompensated Langmuir probes installed in the upper and lower areas of the rf driven H− sources at IPP Garching. The two probes often had substantially different floating potentials or ion saturation currents. In an effort to understand the reasons for these differences a Langmuir probe analysis system was used on the probes to collect the full current voltage characteristic. The results show what is likely the formation of an ion-ion plasma. The paper shows the effect of beam extraction and the presence of caesium on the probe characteristics.
Effect of nitrogen implantation at the SiO2/SiC interface on the electron mobility and free carrier density in 4H-SiC metal oxide semiconductor field effect transistor channel
Authors: Poggi A. , Moscatelli F. , Solmi S. , Armigliato A. , Belsito L. , Nipoti R.
Published: February 2010

The electrical characteristics of n-metal oxide semiconductor field effect transistors (n-MOSFETs) fabricated on 4H-SiC with a process based on nitrogen (N) implantation in the channel region before the growth of the gate oxide are reported as a function of the N concentration at the SiO2/SiC interface. A strong correlation among the increase in the N concentration, the reduction of the interface state density near the conduction band and the improvement of the MOSFET performance was obtained. Hall-effect measurements were used to determine the electron mobility and the free carrier concentration in the MOSFET channel. Among the investigated combinations of N dose and oxidation time, the one with the higher dose and the shorter time produces MOSFETs with the higher N concentration at the SiO2/SiC interface and the best electrical characteristics. This superior performance is obtained in spite of the lowering of the bulk mobility in the channel of this sample, a negative effect probably ascribable to the incomplete recovery of the implantation damage or to the high density of interstitial nitrogen atoms present in the channel region. However, evidence of extended defects, clusters or nanoparticles was not observed by transmission electron microscopy analyses in any of the investigated SiC MOSFET devices.
Study of metal/ZnO based thin film ultraviolet photodetectors: The effect of induced charges on the dynamics of photoconductivity relaxation
Authors: Yadav Harish Kumar , Sreenivas K. , Gupta Vinay
Published: February 2010

Ultraviolet photoconductivity relaxation in ZnO thin films deposited by rf magnetron sputtering are investigated. Effect of oxygen partial pressure in the reactive gas mixture and film thickness on the photoconductivity transients is studied. A different photodetector configuration comprising ZnO thin film with an ultrathin overlayer of metals like Cu, Al, Sn, Au, Cr, and Te was designed and tested. Photoresponse signal were found to be stronger (four to seven times) in these configurations than the pure ZnO thin films. Sn(30 nm)/ZnO sample exhibits highest responsivity of ∼8.57 kV/W whereas Te(20 nm)/ZnO structure presents highest sensitivity of ∼31.3×103 compared to unloaded ZnO thin film. Enhancement in the photoresponse of ZnO thin films is attributed to the change in surface conductivity due to induced charge carriers at the interface because of the difference in work function and oxygen affinity values of metal overlayer with the underlying semiconducting layer. Charge carrier transfer from the metal layer to ZnO creates a surplus of electrons at the interface; a fraction of which are captured by the defect centers (traps) at the surface whereas the remaining one represents free carriers in the conduction band and are responsible for the enhanced photoconductivity.
Modeling of light scattering from micro- and nanotextured surfaces
Authors: Dominé D. , Haug F.-J. , Battaglia C. , Ballif C.
Published: February 2010

We present a calculation routine for the angular and spectral dependence of scattered light after transmission through textured interfaces. Based on a modified Rayleigh–Sommerfeld integral, the treatment requires only measured surface profiles, and the refractive indices of the two materials adjacent to the textured interface but no fitting parameter. For typical surface morphologies used in solar cell fabrication, the calculations correctly reproduce the angle resolved scattering at 543 nm and the total scattered light intensity in the spectral range from 400 to 2000 nm. The model is then applied to predict the behavior of the interface between ZnO and silicon in a thin film solar cell which is not experimentally accessible.
Accurate ab initio potential energy curve of O2. I. Nonrelativistic full configuration interaction valence correlation by the correlation energy extrapolation by intrinsic scaling method
Authors: Bytautas Laimutis , Ruedenberg Klaus
Published: February 2010

The recently introduced method of correlation energy extrapolation by intrinsic scaling is used to calculate the nonrelativistic electron correlations in the valence shell of the O2 molecule at 24 internuclear distances along the ground state Σ3g− potential energy curve from 0.9 to 6 Å, the equilibrium distance being 1.207 52 Å. Using Dunning’s correlation-consistent triple- and quadruple-zeta basis sets, the full configuration interaction energies are determined, with an accuracy of about 0.3 mhartree, by successively generating up to sextuple excitations with respect to multiconfigurational reference functions that strongly change along the reaction path. The energies of the reference functions and those of the correlation energies with respect to these reference functions are then extrapolated to their complete basis set limits.
Calculation of proper energy barriers for atomistic kinetic Monte Carlo simulations on rigid lattice with chemical and strain field long-range effects using artificial neural networks
Authors: Castin N. , Malerba L.
Published: February 2010

In this paper we take a few steps further in the development of an approach based on the use of an artificial neural network (ANN) to introduce long-range chemical effects and zero temperature relaxation (elastic strain) effects in a rigid lattice atomistic kinetic Monte Carlo (AKMC) model. The ANN is trained to predict the vacancy migration energies as calculated given an interatomic potential with the nudged elastic band method, as functions of the local atomic environment. The kinetics of a single-vacancy migration is thus predicted as accurately as possible, within the limits of the given interatomic potential. The detailed procedure to apply this method is described and analyzed in detail. A novel ANN training algorithm is proposed to deal with the necessarily large number of input variables to be taken into account in the mathematical regression of the migration energies. The application of the ANN-based AKMC method to the simulation of a thermal annealing experiment in Fe–20%Cr alloy is reported. The results obtained are found to be in better agreement with experiments, as compared to already published simulations, where no atomic relaxation was taken into account and chemical effects were only heuristically allowed for.
Photoelectron spectroscopy and density functional calculations of FenBO2− clusters
Authors: Feng Yuan , Xu Hong-Guang , Zhang Zeng-Guang , Gao Zhen , Zheng Weijun
Published: February 2010

We conducted a study of FenBO2− clusters by mass spectrometry and photoelectron spectroscopy. The vertical detachment energies and adiabatic detachment energies of these clusters were evaluated from their photoelectron spectra. We have also performed density-functional calculations of FenBO2− (n=1–5) clusters and determined their structures by comparison of theoretical calculations to experimental results. The studies show that BO2 moiety still maintains its linear structure as the bare BO2 cluster. BO2 behaves as a superhalogen. Analysis of molecular orbitals reveals that the highest occupied molecular orbitals of FenBO2− clusters are mainly localized on the Fen units.
Crystallization limits of the two-term Yukawa potentials based on the entropy criterion
Authors: Lee Lloyd L. , Hara Michael C. , Simon Steven J. , Ramos Franklin S. , Winkle Andrew J. , Bomont Jean-Marc
Published: February 2010

We examine the fluid-solid transition for the potential with two Yukawa terms (one attractive and the other repulsive) and a hard core by exploration of the parameter space of (K1, Z1, and Z2), i.e., the parameters of interaction strength and interaction ranges, respectively. We apply the single-phase crystallization rule of Giaquinta and Giunta (1992) by searching for the conditions where the residual entropy reaches zero. To obtain accurate entropy properties, we adopt the self-consistent closure theory of the zero-separation genre. This closure gives accurate thermodynamic properties. The Ornstein–Zernike equation is solved to obtain the correlation functions. The structure factor S(q) is examined with respect to its cluster-cluster peak, whose value is another indication of phase transition according to Hansen and Verlet (1969). We discover that the parameter Z1 (which determines the range of attractive forces) is important in crystal formation, so long as sufficient attraction (parameter K1) is present. If the range of attraction is too narrow, strength alone is not adequate to satisfy the Giaquinta rule or to solidify at given concentration and temperature. The control of the range of repulsion rests with the Z2-parameter. Its variations can bring about a high peak in S(q) at zero wave number (i.e., at q=0). Implications for the crystallization of protein and colloidal solutions are discussed.