bluuebunny/crossref_metadata_2025 huggingface dataset:
Antioxidant activity of growth hormone-releasing hormone antagonists in LNCaP human prostate cancer line
Authors: Barabutis Nektarios , Schally Andrew V.
Published: December 2008

Hypothalamic growth hormone-releasing hormone (GHRH) controls the release of growth hormone and acts as a growth factor in various tumors. Potent antagonistic analogues of GHRH have been synthesized that strongly suppress the growth of diverse cancers through several mechanisms. However, the influence of GHRH antagonists on the redox (reduction/oxidation) status of cancers has not been investigated. Cellular generation of reactive oxygen species (ROS) is central to redox signaling and is implicated in the initiation, development, and progression of cancer. In this study, we evaluated by Western blot the effects
in vitro
of GHRH and its antagonist JMR-132 on proliferating cell nuclear antigen, tumor suppressor protein p53, transcription factor NF-κB p50 and its phosphorylated form, caspase 3, and cleaved caspase 3 in the LNCaP human prostate cancer cell line. GHRH stimulated and GHRH antagonist inhibited the expression of the major antioxidant enzymes, as well as the expression of COX 2 and cytochrome
c
oxidase IV, which are enzymes involved in the generation of ROS. GHRH augmented and GHRH antagonist suppressed lipid and protein oxidative stress markers, as well as the intracellular generation of ROS. In all these tests, GHRH antagonists exerted strong antioxidant activity. Because the metabolism of ROS and oxidative stress have been associated with initiation and progression of not only prostate tumors but also other malignancies, our findings reinforce previous experimental evidence that GHRH antagonists could be useful for cancer therapy.
The role of nutricline depth in regulating the ocean carbon cycle
Authors: Cermeño Pedro , Dutkiewicz Stephanie , Harris Roger P. , Follows Mick , Schofield Oscar , Falkowski Paul G.
Published: December 2008

Carbon uptake by marine phytoplankton, and its export as organic matter to the ocean interior (i.e., the “biological pump”), lowers the partial pressure of carbon dioxide (
p
CO
2
) in the upper ocean and facilitates the diffusive drawdown of atmospheric CO
2
. Conversely, precipitation of calcium carbonate by marine planktonic calcifiers such as coccolithophorids increases
p
CO
2
and promotes its outgassing (i.e., the “alkalinity pump”). Over the past ≈100 million years, these two carbon fluxes have been modulated by the relative abundance of diatoms and coccolithophores, resulting in biological feedback on atmospheric CO
2
and Earth's climate; yet, the processes determining the relative distribution of these two phytoplankton taxa remain poorly understood. We analyzed phytoplankton community composition in the Atlantic Ocean and show that the distribution of diatoms and coccolithophorids is correlated with the nutricline depth, a proxy of nutrient supply to the upper mixed layer of the ocean. Using this analysis in conjunction with a coupled atmosphere–ocean intermediate complexity model, we predict a dramatic reduction in the nutrient supply to the euphotic layer in the coming century as a result of increased thermal stratification. Our findings indicate that, by altering phytoplankton community composition, this causal relationship may lead to a decreased efficiency of the biological pump in sequestering atmospheric CO
2
, implying a positive feedback in the climate system. These results provide a mechanistic basis for understanding the connection between upper ocean dynamics, the calcium carbonate-to-organic C production ratio and atmospheric
p
CO
2
variations on time scales ranging from seasonal cycles to geological transitions.
Ecological and Lyapunov Stability
Authors: Justus James
Published: December 2008

Ecologists have proposed several incompatible definitions of ecological stability. Emulating physicists, mathematical ecologists commonly define it as Lyapunov stability. This formalizes the problematic concept by integrating it into a well-developed mathematical theory. The formalization also seems to capture the intuition that ecological stability depends on how ecological systems respond to perturbation. Despite these advantages, this definition is flawed. Although Lyapunov stability adequately characterizes perturbation responses of many systems studied in physics, it does not for ecological systems. This failure reveals a limitation of its underlying mathematical theory, and an important difference between dynamic systems modeling in physics and ecology.
rHVDM: an R package to predict the activity and targets of a transcription factor
Authors: Barenco M. , Papouli E. , Shah S. , Brewer D. , Miller C.J. , Hubank M.
Published: December 2008

Summary: Highly parallel genomic platforms like microarrays often present researchers with long lists of differentially expressed genes but contain little or no information on how these genes are regulated. rHVDM is a novel R package which uses gene expression time course data to predict the activity and targets of a transcription factor. In the first step, rHVDM uses a small number of known targets to derive the activity profile of a given transcription factor. Then, in a subsequent step, this activity profile is used to predict other putative targets of that transcription factor. A dynamic and mechanistic model of gene expression is at the heart of the technique. Measurement error is taken into account during the process, which allows an objective assessment of the robustness of fit and, therefore, the quality of the predictions. The package relies on efficient algorithms and vectorization to accomplish potentially time consuming tasks including optimization and differential equation integration. We demonstrate the efficiency and accuracy of rHVDM by examining the activity of the tumour-suppressing transcription factor, p53.

Availability: The version of the package presented here (1.8.1) is freely available from the Bioconductor Web site (http://bioconductor.org/packages/2.3/bioc/html/rHVDM.html).

Contact:  m.barenco@ucl.ac.uk

Supplementary information:  Supplementary data are available at Bioinformatics online.
Alternaria alternata and Plectosporium tabacinum on Snap Beans: Pathogenicity, Cultivar Reaction, and Fungicide Efficacy
Authors: Brantner Jason R. , Windels Carol E. , Omer Medani A.
Published: December 2008

Verticillium wilt of sugar beet has not previously been reported in the Red River Valley of Minnesota and North Dakota where both Verticillium dahliae Kleb and V. albo-atrum Reinke & Berthier cause wilt on potato. In August 2003, sugar beet in four fields from eastern North Dakota (sown to potato in 2002) exhibited typical symptoms of Verticillium wilt. Our objectives were to: (i) identify isolates from infected sugar beet and (ii) evaluate them for pathogenicity on sugar beet and potato.

Accepted for publication 22 September 2008. Published 12 December 2008.
Alternaria alternata and Plectosporium tabacinum on Snap Beans: Pathogenicity, Cultivar Reaction, and Fungicide Efficacy
Authors: Dillard Helene R. , Cobb Ann C.
Published: December 2008

Pod-flecking complex (PFC) has become an increasing problem for snap bean production. Pods from several commercial fields in New York and one in Pennsylvania were observed in 2006 with small dark flecks and streaks. Two pathogens were isolated and identified as Alternaria alternata and Plectosporium tabacinum. Isolates varied in aggressiveness, and generally isolates of P. tabacinum caused more disease than isolates of A. alternata. Eight snap bean cultivars were susceptible to A. alternata and P. tabacinum. In greenhouse fungicide efficacy trials pyraclostrobin, chlorothalonil, azoxystrobin, and copper hydroxide provided greater than 43% control of PFC caused by either fungus.

Accepted for publication 18 September 2008. Published 12 December 2008.
Phytophthora alni subsp. uniformis Found in Alaska Beneath Thinleaf Alders
Authors: Adams Gerard C. , Catal Mursel , Trummer Lori , Hansen Everett M. , Reeser Paul , Worrall James J.
Published: December 2008

Phytophthora alni Brasier & S. A. Kirk 2004 is an emergent pathogen causing a lethal root and collar disease of alder species in Europe. The species has not been previously found in North America, although an isolate tentatively referred to as P. alni was reported in a survey of nurseries in Minnesota. The potential establishment and spread of this complex of pathogens is perceived to represent a threat to all species of Alnus in the western hemisphere.

Accepted for publication 2 October 2008. Published 12 December 2008.
Phytophthora alni subsp. uniformis Found in Alaska Beneath Thinleaf Alders
Authors: Glawe Dean A. , Koike Steven T.
Published: December 2008

Periwinkle is a trailing, spreading evergreen plant used in landscapes as a groundcover. Beginning in 2005, a powdery mildew was observed on periwinkle in coastal (Monterey Co.) California. As reported herein, the causal agent was determined to be Golovinomyces orontii (Castagne) V.P. Heluta. This appears to be the first record of a powdery mildew species on Vinca spp. in North America.

Accepted for publication 16 October 2008. Published 12 December 2008.
Blood leucocyte cytokine production after LPS stimulation at different concentrations of glucose and/or insulin
Authors: BEITLAND S. , OPDAHL H. , ASPELIN T. , SAETRE L. , LYBERG T.
Published: December 2008

Background: Previous studies have indicated that alterations in blood glucose and/or insulin levels modify the inflammatory response. The purpose of this study was to elucidate whether increased levels of glucose and/or insulin influence the activation pattern of blood leucocytes and their production of cytokines in vitro.

Methods: Venous blood was obtained from eight healthy male volunteers after an overnight fast. Glucose and/or insulin were added to aliquots of whole blood to increase the blood glucose concentration by 5 or 20 mmol/l and/or the insulin concentration by 6 or 30 nmol/l, respectively, before stimulation with E. coli lipopolysaccharide (LPS) at concentrations of 10, 100 or 1000 ng/ml. The samples were subsequently incubated at 37 °C for 6 h before cytokine measurements. After centrifugation the levels of interleukins (IL)‐1β, IL‐6, IL‐8, IL‐10 and tumour necrosis factor (TNF)‐α were measured in plasma using enzyme‐linked immuno‐sorbent assays. The results were compared with cytokine levels in parallel control samples to which only identical amounts of LPS were added.

Results: The LPS‐stimulated production of IL‐1β was significantly reduced by on average 26% in samples to which glucose 20 mmol/l was added; addition of insulin and/or glucose 5 mmol/l had no apparent effect on the IL‐1β production at any LPS concentration. The levels of IL‐6, IL‐8, IL‐10 and TNF‐α were not manifestly altered by addition of glucose and/or insulin at any LPS concentration.

Conclusion: A substantial increase in blood glucose concentration changed the IL‐1β production, but not the production of other cytokines, in response to LPS stimulation.
When the Truth Is Not Too Hard to Handle
Authors: Nieuwland Mante S. , Kuperberg Gina R.
Published: December 2008

Our brains rapidly map incoming language onto what we hold to be true. Yet there are claims that such integration and verification processes are delayed in sentences containing negation words like not. However, studies have often confounded whether a statement is true and whether it is a natural thing to say during normal communication. In an event-related potential (ERP) experiment, we aimed to disentangle effects of truth value and pragmatic licensing on the comprehension of affirmative and negated real-world statements. As in affirmative sentences, false words elicited a larger N400 ERP than did true words in pragmatically licensed negated sentences (e.g., “In moderation, drinking red wine isn't bad/good…”), whereas true and false words elicited similar responses in unlicensed negated sentences (e.g., “A baby bunny's fur isn't very hard/soft…”). These results suggest that negation poses no principled obstacle for readers to immediately relate incoming words to what they hold to be true.
With a Clean Conscience
Authors: Schnall Simone , Benton Jennifer , Harvey Sophie
Published: December 2008

Theories of moral judgment have long emphasized reasoning and conscious thought while downplaying the role of intuitive and contextual influences. However, recent research has demonstrated that incidental feelings of disgust can influence moral judgments and make them more severe. This study involved two experiments demonstrating that the reverse effect can occur when the notion of physical purity is made salient, thus making moral judgments less severe. After having the cognitive concept of cleanliness activated (Experiment 1) or after physically cleansing themselves after experiencing disgust (Experiment 2), participants found certain moral actions to be less wrong than did participants who had not been exposed to a cleanliness manipulation. The findings support the idea that moral judgment can be driven by intuitive processes, rather than deliberate reasoning. One of those intuitions appears to be physical purity, because it has a strong connection to moral purity.
An In-Group Advantage in Detecting Intergroup Anxiety
Authors: Gray Heather M. , Mendes Wendy Berry , Denny-Brown Carrigan
Published: December 2008

We examined the possibility of an in-group advantage in detecting intergroup anxiety. Specifically, we videotaped White and Black participants while they engaged in same-race or interrace interactions. Then we asked White and Black observers to view these videotapes (unaware of the racial context) and provide their impressions of participants' anxiety. Two results pointed to an in-group advantage in detecting intergroup anxiety. First, only same-race observers perceived a modulation of participants' anxious behavior as a function of racial context. This held true not only for relatively subjective perceptions of global anxiety, but also for perceptions of single, discrete behaviors tied to anxiety. Second, we found that only same-race observers provided descriptions of anxiety that tracked reliably with participants' cortisol changes during the task. These results suggest that White and Black Americans may have difficulty developing a sense of shared emotional experience.
Gender Recognition of Human Faces Using Color
Authors: Nestor Adrian , Tarr Michael J.
Published: December 2008

A continuing question in the object recognition literature is whether surface properties play a role in visual representation and recognition. Here, we examined the use of color as a cue in facial gender recognition by applying a version of reverse correlation to face categorization in CIE L∗a∗b∗ color space. We found that observers exploited color information to classify ambiguous signals embedded in chromatic noise. The method also allowed us to identify the specific spatial locations and the components of color used by observers. Although the color patterns found with human observers did not accurately mirror objective natural color differences, they suggest sensitivity to the contrast between the main features and the rest of the face. Overall, the results provide evidence that observers encode and can use the local color properties of faces, in particular, in tasks in which color provides diagnostic information and the availability of other cues is reduced.
Is Relative Pitch Specific to Pitch?
Authors: McDermott Josh H. , Lehr Andriana J. , Oxenham Andrew J.
Published: December 2008

Melodies, speech, and other stimuli that vary in pitch are processed largely in terms of the relative pitch differences between sounds. Relative representations permit recognition of pitch patterns despite variations in overall pitch level between instruments or speakers. A key component of relative pitch is the sequence of pitch increases and decreases from note to note, known as the melodic contour. Here we report that contour representations are also produced by patterns in loudness and brightness (an aspect of timbre). The representations of contours in different dimensions evidently have much in common, as contours in one dimension can be readily recognized in other dimensions. Moreover, contours in loudness and brightness are nearly as useful as pitch contours for recognizing familiar melodies that are normally conveyed via pitch. Our results indicate that relative representations via contour extraction are a general feature of the auditory system, and may have a common central locus.
The Fragility of Intergroup Relations
Authors: Pearson Adam R. , West Tessa V. , Dovidio John F. , Powers Stacie Renfro , Buck Ross , Henning Robert
Published: December 2008

Intergroup interactions between racial or ethnic majority and minority groups are often stressful for members of both groups; however, the dynamic processes that promote or alleviate tension in intergroup interaction remain poorly understood. Here we identify a behavioral mechanism—response delay—that can uniquely contribute to anxiety and promote disengagement from intergroup contact. Minimally acquainted White, Black, and Latino participants engaged in intergroup or intragroup dyadic conversation either in real time or with a subtle temporal disruption (1-s delay) in audiovisual feedback. Whereas intergroup dyads reported greater anxiety and less interest in contact after engaging in delayed conversation than after engaging in real-time conversation, intragroup dyads reported less anxiety in the delay condition than they did after interacting in real time. These findings have theoretical and practical implications for understanding intergroup communication and social dynamics and for promoting positive intergroup contact.
Reorienting When Cues Conflict
Authors: Ratliff Kristin R. , Newcombe Nora S.
Published: December 2008

Proponents of a geometric module claim that human adults accomplish spatial reorientation in a fundamentally different way than young children and non-human animals do. However, reporting two experiments that used a conflict paradigm, this article shows striking similarities between human adults and young children, as well as nonhuman animals. Specifically, Experiment 1 demonstrates that adults favor geometric information in a small room and rely on features in a larger room, whereas Experiment 2 demonstrates that experience in a larger room produces dominance of features over geometric cues in a small room—the first human case of reliance on features that contradict geometric information. Thus, use of features during reorientation depends on the size of the environment and learning history. These results clearly undermine the modularity claim and the view that feature use during reorientation is purely associative, and we discuss the findings within an adaptive-combination view, according to which a weighting system determines use of feature or geometric cues during reorientation.
Driving Under the Influence (of Stress)
Authors: Su Jenny C. , Tran Alisia G.T.T. , Wirtz John G. , Langteau Rita A. , Rothman Alexander J.
Published: December 2008

Did the September 11 terrorist attacks elicit a subsequent increase in traffic fatalities? Gigerenzer (2004) argued that decreases in flying and increases in driving in the 3 months after the attacks led to 353 “surplus” traffic fatalities. We applied a more systematic analysis to the same data and found no evidence of a significant increase in miles driven or of a significant increase in traffic fatalities. However, we did find evidence for a regional effect of the attacks on driving behaviors. We hypothesized that geographic proximity to the attacks increased stress, which in turn decreased driving quality. Our analyses revealed that in the last 3 months of 2001, the Northeast exhibited a significant increase in traffic fatalities, as well as a significant increase in fatal accidents involving an alcohol- or drug-related citation. Increased stress related to physical proximity to the attacks may explain the increase in traffic fatalities.
Clobazam in the treatment of Lennox‐Gastaut syndrome
Authors: Conry Joan A. , Ng Yu‐Tze , Paolicchi Juliann M. , Kernitsky Lydia , Mitchell Wendy G. , Ritter Frank J. , Collins Stephen D. , Tracy Katherine , Kormany William N. , Abdulnabi Radhi , Riley Bill , Stolle Julie
Published: December 2008

Purpose:  This randomized, double‐blind, dose‐ranging study evaluated safety and efficacy of clobazam (CLB) as adjunctive therapy for drop seizures in patients with Lennox‐Gastaut syndrome (LGS).

Methods:  Sixty‐eight patients with LGS aged 2–26 years were administered CLB (low dose = target 0.25 mg/kg/day; high dose = target 1.0 mg/kg/day). The study consisted of 4‐week baseline, 3‐week titration, and 4‐week maintenance periods, followed by a 3‐week taper or continuation in an open‐label study. Seizure frequency was recorded in a diary by the parent/caregiver throughout the study.

Results:  Weekly drop seizure rates were significantly reduced from baseline in both the high‐dose and low‐dose groups; the reduction was significantly greater in the high‐dose group. A significantly greater proportion of patients in the high‐dose group experienced reductions in drop seizures of ≥25%, ≥50%, and ≥75% compared to the low‐dose group; more patients in the high‐dose group experienced a 100% reduction, but the difference was not significant. Nondrop seizures were also reduced in a dose‐dependent manner. In both investigator and parent/caregiver global evaluations, patients in the high‐dose group showed significantly greater improvements in overall symptoms compared to low‐dose CLB. Adverse events were generally mild or moderate, and were similar between dose groups. Five serious adverse events were reported in four patients, but in no case was CLB discontinued.

Conclusions:  Clobazam was well tolerated and reduced drop seizure rates; high‐dose CLB was more effective than low‐dose CLB. Other seizure types were also reduced.
Association of subjective anxiety, depression, and sleep disturbance with quality‐of‐life ratings in adults with epilepsy
Authors: Kwan Patrick , Yu Evelyn , Leung Howan , Leon Teresa , Mychaskiw Marko A.
Published: December 2008

Purpose:  To determine the relative contributions of subjective anxiety, depression, sleep disturbance, and seizure‐related variables to quality‐of‐life scores in adults with epilepsy, and the interrelationships among these factors.

Methods:  Consecutive adult patients with epilepsy attending neurology outpatient clinics were recruited. Patients completed the following scales: Hospital Anxiety and Depression Scale (HADS), Hamilton Anxiety Rating Scale, Medical Outcomes Study (MOS) Sleep Scale, Epworth Sleepiness Scale, and Quality of Life in Epilepsy Inventory‐31 (QOLIE‐31). Univariate and multivariate linear regression models were used to identify variables associated with QOLIE‐31 overall score. Path analysis model was constructed to test for interrelations between the variables.

Results:  Two hundred forty‐seven patients completed the questionnaires. By multivariate analysis, in order of degree of contribution, HADS anxiety subscale score, MOS Sleep Scale Sleep Problems Index score, HADS depression subscale score, number of current antiepileptic drugs used, and seizure freedom in the past 4 weeks, significantly correlated with QOLIE‐31 overall score, accounting for 65.2% of the variance. Complex interrelationships were present between these factors. A general linear model to predict QOLIE‐31 overall score in the presence of these factors was constructed.

Conclusion:  Subjective anxiety, depression, and sleep disturbance exerted greater effect than short‐term seizure control on quality of life scores of patients with epilepsy. These factors should be considered simultaneously when evaluating effects of treatment on quality of life.
Effect of CuO on the Sintering and Piezoelectric Properties of 0.95(Na0.5K0.5)NbO3–0.05SrTiO3Lead‐Free Piezoelectric Ceramics
Authors: Seo In‐Tae , Cho Kyung‐Hoon , Park Hwi‐Yeol , Park Seok‐Jung , Choi Min‐Kyu , Nahm Sahn , Lee Hyeung‐Gyu , Kang Hyung‐Won , Lee Hwac‐Joo
Published: December 2008

CuO was used to enhance the sinterability of 0.95(Na0.5K0.5)NbO3–0.05SrTiO3(0.95NKN–0.05ST) ceramics. The poor sinterability of 0.95NKN–0.05ST ceramics was improved by the addition of 1.5 mol% CuO, so that they were well sintered even at 960°C with grain growth. The densification and grain growth were attributed to liquid‐phase sintering, probably due to the presence of a liquid phase containing SrO and CuO. The grain size decreased when the sintering temperature exceeded 960°C, due to the presence of a large amount of liquid phase. The microstructure of the 0.95NKN–0.05ST ceramics was considerably affected by even small variations of sintering temperature. Thed33,kp, andQmvalues increased with CuO addition due to the increased density and grain size. The high piezoelectric properties ofkp=0.35,d33=200, and ɛ33T/ɛo=1235 were obtained from the 0.95NKN–0.05ST ceramics containing 1.5 mol% CuO sintered at 960°C for 10 h.
Microwave Dielectric Properties of a New Ultra Low Loss Pervoskite Ceramic
Authors: Tseng Ching‐Fang
Published: December 2008

The microwave dielectric properties and microstructures of an Mg(Zr0.05Ti0.95)O3 ceramic system have been investigated. The compounds were prepared by the conventional solid‐state route, and sintered at 1360°–1450°C for 2–6 h. The structure and microstructure were analyzed using X‐ray diffraction and scanning electron microscopy techniques. The Mg(Zr0.05Ti0.95)O3 had excellent dielectric properties: Q×f=380 000 (GHz), ɛr=18.1, and τf=−50 ppm/°C for the sample at 1420°C/4 h. These properties were correlated with the formation of second phases, Mg2TiO4 and Mg0.25Zr0.38Ti0.38O1.75.
Thermal Decomposition of Indium(III) Hydroxide Prepared by the Microwave‐Assisted Hydrothermal Method
Authors: Koga Nobuyoshi , Kimizu Takaaki
Published: December 2008

Cubic‐shaped In(OH)3 particles with average size of 0.348 μm were precipitated from a mixed aqueous solution of InCl3 and urea by a microwave‐assisted hydrothermal method. The kinetics and mechanisms of the thermal decomposition of the sample were investigated by means of thermoanalytical measurements under three different modes of temperature program, complemented by several physicochemical techniques. No intermediate compound was found during the course of thermal decomposition from cubic‐In(OH)3 to cubic‐In2O3. Distinguished induction period for the thermal decomposition was identified as one of the most characteristic kinetic phenomena of the present reaction, together with the crack formation on the surface product layer during the second half of the reaction. The kinetic rate behavior of the reaction was characterized physicogeometrically as the surface nucleation and subsequent advancement of the established reaction interface inward toward the center of the reactant particle, where the apparent activation energies for the surface nucleation and advancement of the reaction interface were estimated as 257 and 140 kJ/mol, respectively.
Selective Synthesis of Lithium Ion‐Conductive β‐LiVOPO4 Crystals via Glass–Ceramic Processing
Authors: Nagamine Kenta , Honma Tsuyoshi , Komatsu Takayuki
Published: December 2008

A glass–ceramic processing is applied to a glass with the composition of 33.3Li2O–33.3V2O5–33.3P2O5 (mol%) in order to synthesize lithium ion‐conductive β‐LiVOPO4 crystals being a potential candidate for cathode materials in lithium ion batteries. It is found that three crystalline phases of α‐LiVOPO4, Li2VPO6, and β‐LiVOPO4 are formed during the crystallization and α‐LiVOPO4 crystals formed initially transform into β‐LiVOPO4. The glass–ceramics consisting of almost mainly β‐LiVOPO4 crystals are successfully prepared by a heat treatment at around 600°C in air. The glass–ceramics with β‐LiVOPO4 crystals show the electrical conductivity of 1.7 × 10−7 S/cm at room temperature and the activation energy of 0.38 eV in the temperature range of 25°–240°C. The structure and electrical properties of the precursor glass are also examined. The present study proposes that the glass–ceramic processing has an advantage for the fabrication of β‐LiVOPO4 crystals, because it is difficult to synthesize β‐LiVOPO4 crystals using a conventional powder‐sintering method.
Thermal Properties, Microstructure, and Conductivity of New Glasses Based on the GeSe2–Ga2Se3–AgI System
Authors: Tang Gao , Liu Cunming , Luo Lan , Chen Wei
Published: December 2008

A new class of GeSe2–Ga2Se3–AgI glass systems has been prepared and its glass‐forming region was identified. The maximum dissolvable AgI in glasses was up to 60 mol%. The thermal, optical, and structural properties of glasses were investigated as a function of AgI and Ga2Se3 contents. The GeSe2–Ga2Se3–AgI glasses have a wide region of transmission window (0.6–16 μm) and a high glass transition temperature (Tg). The conductivities of the samples have been determined by impedance spectroscopy. The maximum ionic conductivity value of around 3.32 × 10−5 S/cm can be obtained for samples at room temperature. Arrhenius behavior is verified between 30° and 310°C for glasses with activation energies of 0.287 eV. Consequently, these novel glasses may be promising candidate materials for infrared optics and solid electrolyte applications.
Large‐Scale Controllable Synthesis and Characterization of Ytterbium Silicate Nanostructures
Authors: Sun Hong‐Tao , Fujii Minoru , Nitta Noriko , Shimaoka Fumiaki , Mizuhata Minoru , Yasuda Hidehiro , Deki Shigehito , Hayashi Shinji
Published: December 2008

Large‐scale synthesis of ytterbium silicate (Yb2SiO5) nanoparticles and nanorods has been realized by a facile molten‐salt approach. The synthesized products were structurally and morphologically characterized by X‐ray diffraction, transmission electron microscopy (TEM), and high‐resolution TEM. Our results revealed that the morphologies of Yb2SiO5 products can be readily controlled by a simple variation of the reactants used for the molten‐salt reaction. Single‐crystalline Yb2SiO5 nanorods with a high yield can be obtained using NP‐7.5 as a surfactant. The formation mechanism of Yb2SiO5 nanostructures was also discussed. The method presented here for the synthesis of Yb2SiO5 nanostructures may pave the way for their application as environmental barrier coating materials.
Fabrication and Characterization of a (100) Three‐Axis‐Oriented Single‐Crystal (Ba0.7Sr0.3)TiO3 Thin Film Prepared by the Chemical Solution Deposition Method
Authors: Hosokura Tadasu , Kageyama Keisuke , Takagi Hiroshi , Sakabe Yukio
Published: December 2008

Epitaxially grown single‐crystal perovskite (100) three‐axis‐oriented (Ba0.7Sr0.3)TiO3 thin films were prepared on a (100) platinum‐coated (100) magnesium oxide (MgO) single‐crystal substrate by the chemical solution deposition method using a solution derived from Ba(CH3COO)2, Sr(CH3COO)2, and Ti(O‐i‐C3H7)4.

The growth of the film was found to depend on the annealing condition. A (Ba,Sr)TiO3 thin film annealed at 1073 K was found to be a single crystal by transmission electron microscope. The single‐crystal film exhibited a (100) three‐axis orientation that followed the (100) orientation of the Pt substrate, as observed from an X‐ray pole figure measurement and selected area electron diffraction patterns.
Phenyl‐Substituted Siloxane Hybrid Gels that Soften Below 140°C
Authors: Jitianu Andrei , Amatucci Glenn , Klein Lisa C.
Published: December 2008

A characteristic of so‐called melting gels is that the gels, which are rigid at room temperature, are able to soften and resoften at temperatures around 110°C. However, after consolidation at temperatures higher than 150°C, the gels no longer resoften. Two systems of melting gels were investigated: phenyltrimethoxysilane (PhTMS)–diphenyldimethoxysilane (DPhDMS) and phenyltriethoxysilane (PhTES)–diphenyldiethoxysilane (DPhDES). The influence of disubstituted versus monosubstituted alkoxide on the softening behavior and the temperature of decomposition was studied. The consolidation temperature increased as the amount of disubstituted alkoxide increased, while the decomposition temperature increased only slightly. In general, the ethoxy‐containing gels (maximum at 150°C) consolidated at lower temperatures than the methoxy‐containing gels (maximum at 180°C).
Stability Domains of TiO2–Ti3O5–Ti2O3–TiC/Ti(CN) Systems During Reduction Process
Authors: Kwon Hanjung , Kang Shinhoo
Published: December 2008

The phase domain of Ti3O5–Ti2O3–Ti(CO) at 1580 K was determined from the formation energies of Ti(CxOy), as calculated via the Gibbs–Duhem equation. An extensive Ti(CO) domain is attributed to the high affinity between TiC and TiO. The phase domain of Ti3O5–Ti2O3–Ti(CN) was obtained at 1673 K using the formation energies of Ti(CxNy). This study shows that the stable region for Ti2O3 is significantly small in the Ti3O5–Ti2O3–Ti(CN) phase domain. It demonstrates the absence of TiO and Ti2O3 in the normal syntheses of TiC and Ti(CN) from TiO2, respectively.
Cost‐Effective Microstructural Engineering of Solid Oxide Fuel Cell Components for Planar and Tubular Designs
Authors: Ruiz‐Morales Juan Carlos , Peña‐Martínez Juan , Canales‐Vázquez Jesús , Marrero‐López David , Savaniu Cristian , Núñez Pedro
Published: December 2008

A novel, simple, and cost‐effective method allows material engineering for the creation of a 2D/3D matrix of cross‐linked channels through whole solid oxide fuel cell (SOFC) electrode materials. The size of the channels can be precisely tailored from a few micrometers up to 75–90 μm and remains stable up to 1500°C. Because of the versatility of the method proposed, it can be applied to practically any type of material commonly used in SOFC technology or in other fields.
Systems Biology of Growth Factor‐Induced Receptor Endocytosis
Authors: Zwang Yaara , Yarden Yosef
Published: December 2008

Clathrin‐mediated endocytosis sorts for degradation of more than 50 different growth factor receptors capable of relaying growth and differentiation signals by means of their cytoplasm‐facing, intrinsic tyrosine kinase activity. The kinetics and alternative routings of receptor endocytosis critically regulate growth factor signaling, which underscores the importance of understanding mechanisms underlying fail‐safe operation (robustness) and fidelity of the pathway. Like other robust systems, a layered hub‐centric network controls receptor endocytosis. Characteristically, the modular hubs (e.g., AP2–Eps15 and Hrs) contain a membrane‐anchoring lipid‐binding domain, an ubiquitin‐binding module, which recruits ubiquitinylated cargo, and a machinery enabling homo‐assembly. Scheduled hub transitions, as well as cascades of Rab family guanosine triphosphatases and membrane bending machineries, define points of commitment to vesicle budding, thereby securing unidirectional trafficking. System’s bistability permits stimulation by a growth factor, which oscillates a series of switches based on posttranslational protein modifications (i.e., phosphorylation, ubiquitinylation and neddylation), as well as transient low‐affinity/high‐avidity protein assemblies. Cbl family ubiquitin ligases, along with a set of phosphotyrosine‐binding adaptors (e.g., Grb2), integrate receptor endocytosis into the densely wired networks of signal transduction pathways, which are involved in health and disease.
Tumour necrosis factor‐related apoptosis‐inducing ligand (TRAIL)‐induced chemokine release in both TRAIL‐resistant and TRAIL‐sensitive cells via nuclear factor kappa B
Authors: Tang Wanhu , Wang Weimin , Zhang Yaxi , Liu Shilian , Liu Yanxin , Zheng Dexian
Published: December 2008

Tumour necrosis factor‐related apoptosis‐inducing ligand (TRAIL) induces apoptosis in a variety of tumour cells, but not in most normal cells, and has attracted considerable attention for its potential use in cancer therapy. Recently, increasing evidence has shown that TRAIL is involved in inflammation, although much of this evidence is controversial. In this article, it is shown that TRAIL induces CXCL2, CCL4 and CCL20 secretion in a nuclear factor kappa B‐dependent manner. The dominant negative constructs of tumour necrosis factor receptor‐associated death domain protein (TRADD) and tumour necrosis factor receptor‐associated factor 2 are unable to block TRAIL‐induced chemokine up‐regulation, and the dominant negative construct of TRADD may even enhance TRAIL‐triggered signals. Using small interfering RNA, receptor interacting protein has been demonstrated to be essential for TRAIL‐induced chemokine release. Furthermore, it has been demonstrated that p38 mitogen‐activated protein kinase is involved in TRAIL‐induced chemokine release without any effects on nuclear factor kappa B activation, suggesting that some unknown transcription factors may be activated by TRAIL. Using a xenograft tumour model, it has been illustrated that TRAIL can also induce chemokine release in vivo. Although these chemokines induced by TRAIL are inflammatory chemokines, their functions are not restricted to inflammation and require further examination. Our results indicate that attention should be paid to the side‐effects of TRAIL treatment, not only in TRAIL‐resistant but also in TRAIL‐sensitive tumour cells.
Destabilization of psychrotrophic RNase HI in a localized fashion as revealed by mutational and X‐ray crystallographic analyses
Authors: Rohman Muhammad S. , Tadokoro Takashi , Angkawidjaja Clement , Abe Yumi , Matsumura Hiroyoshi , Koga Yuichi , Takano Kazufumi , Kanaya Shigenori
Published: December 2008

The Arg97 → Gly and Asp136 → His mutations stabilized So‐RNase HI from the psychrotrophic bacterium Shewanella oneidensis MR‐1 by 5.4 and 9.7 °C, respectively, in Tm, and 3.5 and 6.1 kJ·mol−1, respectively, in ΔG(H2O). These mutations also stabilized the So‐RNase HI derivative (4×‐RNase HI) with quadruple thermostabilizing mutations in an additive manner. As a result, the resultant sextuple mutant protein (6×‐RNase HI) was more stable than the wild‐type protein by 28.8 °C in Tm and 27.0 kJ·mol−1 in ΔG(H2O). To analyse the effects of the mutations on the protein structure, the crystal structure of the 6×‐RNase HI protein was determined at 2.5 Å resolution. The main chain fold and interactions of the side‐chains of the 6×‐RNase HI protein were basically identical to those of the wild‐type protein, except for the mutation sites. These results indicate that all six mutations independently affect the protein structure, and are consistent with the fact that the thermostabilizing effects of the mutations are roughly additive. The introduction of favourable interactions and the elimination of unfavourable interactions by the mutations contribute to the stabilization of the 6×‐RNase HI protein. We propose that So‐RNase HI is destabilized when compared with its mesophilic and thermophilic counterparts in a localized fashion by increasing the number of amino acid residues unfavourable for protein stability.
Regulators of G‐protein signalling are modulated by bacterial lipopeptides and lipopolysaccharide
Authors: Riekenberg Sabine , Farhat Katja , Debarry Jennifer , Heine Holger , Jung Günther , Wiesmüller Karl‐Heinz , Ulmer Artur J.
Published: December 2008

Regulators of G‐protein signalling accelerate the GTPase activity of Gα subunits, driving G proteins in their inactive GDP‐bound form. This property defines them as GTPase activating proteins. Here the effect of different Toll‐like receptor agonists on RGS1 and RGS2 expression in murine bone marrow‐derived macrophages and J774 cells was analysed. After stimulation with TLR2/1 or TLR2/6 lipopeptide ligands and the TLR4/MD2 ligand lipopolysaccharide, microarray analyses show only modulation of RGS1 and RGS2 among all the regulators of G‐protein signalling tested. Real‐time PCR confirmed modulation of RGS1 and RGS2. In contrast to RGS2, which was always downregulated, RGS1 mRNA was upregulated during the first 30 min after stimulation, followed by downregulation. Similar results were also found in the murine macrophage cell line J774. The ligand for intracellular TLR9 modulates RGS1 and RGS2 in a similar manner. However, the TLR3 ligand poly(I:C) permanently upregulates RGS1 and RGS2 expression indicating a different modulation by the MyD88‐ and TRIF‐signalling pathway. This was confirmed using MyD88−/− and TRIF−/− bone marrow‐derived macrophages. Modulation of RGS1 and RGS2 by Toll‐like receptor ligands plays an important role during inflammatory and immunological reactions after bacterial and viral infection.
Rapid and local autoregulation of cerebrovascular blood flow: a deep‐brain imaging study in the mouse
Authors: Kuga Nahoko , Hirata Tadashi , Sakai Ikuko , Tanikawa Yoshihisa , Chiou Huei Yu , Kitanishi Takuma , Matsuki Norio , Ikegaya Yuji
Published: December 2008

The brain obtains energy by keeping the cerebral blood flow constant against unexpected changes in systemic blood pressure. Although this homeostatic mechanism is widely known as cerebrovascular autoregulation, it is not understood how widely and how robustly it works in the brain. Using a needle‐like objective lens designed for deep‐tissue imaging, we quantified the degree of autoregulation in the mouse hippocampus with single‐capillary resolution. On average, hippocampal blood flow exhibited autoregulation over a comparatively broad range of arterial blood pressure and did not significantly respond to pressure changes induced by the pharmacological activation of autonomic nervous system receptors, whereas peripheral tissues showed linear blood flow changes. At the level of individual capillaries, however, about 40% of hippocampal capillaries did not undergo rapid autoregulation. This heterogeneity suggests the presence of a local baroreflex system to implement cerebral autoregulation.
Where the O2goes to: preservation of human fetal oxygen delivery and consumption at high altitude
Authors: Postigo Lucrecia , Heredia Gladys , Illsley Nicholas P. , Torricos Tatiana , Dolan Caitlin , Echalar Lourdes , Tellez Wilma , Maldonado Ivan , Brimacombe Michael , Balanza Elfride , Vargas Enrique , Zamudio Stacy
Published: December 2008

Fetal growth is decreased at high altitude (> 2700 m). We hypothesized that variation in fetal O2delivery might account for both the altitude effect and the relative preservation of fetal growth in multigenerational natives to high altitude. Participants were 168 women of European or Andean ancestry living at 3600 m or 400 m. Ancestry was genetically confirmed. Umbilical vein blood flow was measured using ultrasound and Doppler. Cord blood samples permitted calculation of fetal O2delivery and consumption. Andean fetuses had greater blood flow and oxygen delivery than Europeans and weighed more at birth, regardless of altitude (+208 g,P< 0.0001). Fetal blood flow was decreased at 3600 m (P< 0.0001); the decrement was similar in both ancestry groups. Altitude‐associated decrease in birth weight was greater in Europeans (−417 g) than Andeans (−228 g,P< 0.005). Birth weight at 3600 m was > 200 g lower for Europeans at any given level of blood flow or O2delivery. Fetal haemoglobin concentration was increased,decreased, and the fetal/curve was left‐shifted at 3600 m. Fetuses receiving less O2extracted more (r2= 0.35,P< 0.0001). These adaptations resulted in similar fetal O2delivery and consumption across all four groups. Increased umbilical venous O2delivery correlated with increased fetal O2consumption per kg weight (r2= 0.50,P< 0.0001). Blood flow (r2= 0.16,P< 0.001) and O2delivery (r2= 0.17,P< 0.001) correlated with birth weight at 3600 m, but not at 400 m (r2= 0.04, and 0.03, respectively). We concluded that the most pronounced difference at high altitude is reduced fetal blood flow, but fetal haematological adaptation and fetal capacity to increase O2extraction indicates that deficit in fetal oxygen delivery is unlikely to be causally associated with the altitude‐ and ancestry‐related differences in fetal growth.
In Vitro Activity of LK-157, a Novel Tricyclic Carbapenem As Broad-Spectrum β-Lactamase Inhibitor
Authors: Paukner Susanne , Hesse Lars , Preželj Andrej , Šolmajer Tomaž , Urleb Uroš
Published: December 2008

LK-157 is a novel tricyclic carbapenem with potent activity against class A and class C β-lactamases. When tested against the purified TEM-1 and SHV-1 enzymes, LK-157 exhibited 50% inhibitory concentrations (IC
50
s) in the ranges of the clavulanic acid and tazobactam IC
50
s (55 nM and 151 nM, respectively). Moreover, LK-157 significantly inhibited AmpC β-lactamase (IC
50
, 62 nM), as LK-157 was >2,000-fold more potent than clavulanic acid and approximately 28-fold more active than tazobactam. The in vitro activities of LK-157 in combination with amoxicillin, piperacillin, ceftazidime, cefotaxime, ceftriaxone, cefepime, cefpirome, and aztreonam against an array of Ambler class A (TEM-, SHV-, CTX-M-, KPC-, PER-, BRO-, and PC-type)- and class C-producing bacterial strains derived from clinical settings were evaluated in synergism experiments and compared with those of clavulanic acid, tazobactam, and sulbactam. In vitro MICs against ESBL-producing strains (except CTX-M-containing strains) were reduced 2- to >256-fold, and those against AmpC-producing strains were reduced even up to >32-fold. The lowest MICs (≤0.025 to 1.6 μg/ml) were observed for the combination of cefepime and cefpirome with a constant LK-157 concentration of 4 μg/ml, thus raising an interest for further development. LK-157 proved to be a potent β-lactamase inhibitor, combining activity against class A and class C β-lactamases, which is an absolute necessity for use in the clinical setting due to the worldwide increasing prevalence of bacterial strains resistant to β-lactam antibiotics.
Effect of Differences in MIC Values on Clinical Outcomes in Patients with Bloodstream Infections Caused by Gram-Negative Organisms Treated with Levofloxacin
Authors: DeFife Robyn , Scheetz Marc H. , Feinglass Joe M. , Postelnick Michael J. , Scarsi Kimberly K.
Published: December 2008

Emerging evidence suggests that current fluoroquinolone dosing strategies may be inadequate to treat bloodstream infections caused by organisms classified as sensitive. This study sought to determine if differences in MICs for levofloxacin-susceptible gram-negative organisms correlate with differences in patient outcomes. A retrospective cohort study evaluated patients treated with levofloxacin for bloodstream infections caused by susceptible gram-negative organisms. Patients infected with gram-negative organisms for which MICs indicated susceptibility were categorized into three groups: those with organisms for which MICs were low (≤0.25 mg/liter), intermediate (0.5 mg/liter), and high (1 or 2 mg/liter). Patients were evaluated for baseline similarity, all-cause mortality, and measurements of morbidity. A total of 404 patients with bloodstream infections caused by gram-negative organisms were identified. Of these patients, 312 were treated with levofloxacin and included in the analysis. No significant difference in all-cause mortality among the three groups was observed. The high-MIC group had a significantly longer average hospital stay postculture than the low- and intermediate-MIC groups (16.4 days versus 7.3 and 7.9 days;
P
< 0.01) and a significantly longer duration of infection (2.1 days versus 1.0 and 1.2 days;
P
< 0.001). Multivariate analysis adjusting for covariates revealed that a high MIC was associated with an increase of 5.67 days (95% confidence interval, 0.77 to 10.62 days;
P
= 0.02) in the mean length of stay postculture compared to the mean length of stay for the low-MIC group. Patients treated with levofloxacin for bloodstream infections caused by gram-negative organisms for which MICs were elevated, yet still in the susceptible category, had worse outcomes than similar patients infected with organisms for which MICs were lower. In vitro susceptibility classifications of fluoroquinolones for the treatment of bloodstream infections caused by gram-negative organisms require further study.