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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Journal of High Resolution Chromatography 22 (1999), S. 11-16 
    ISSN: 0935-6304
    Keywords: Pyrolysis gas chromatography ; microstructure determination ; syndiotactic copolymers ; styrenes ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: ---The composition and microstructure of syndiotactic para-methylstyrene/styrene copolymer was determined by a pyrolysis gas chromatography (Py-GC) method. This method uses the styrene and para-methylstyrene monomer peak intensities to determine the styrene and para-methylstyrene composition in the copolymer. The number average sequence length of styrene was calculated by using the triad peak intensities. Because of the low concentration of para-methylstyrene in the copolymer, the number average sequence length of para-methylstyrene was determined with formulas that incorporate the copolymer composition and the number average sequence length of styrene. The distribution of para-methylstyrene defined by the terms “percent of single units” and “percent of desired distribution” was calculated by the number average sequence of para-methylstyrene. This method has been tested with copolymers containing up to 24 mole% of para-methylstyrene. The composition results from Py-GC of para-methylstyrene and styrene copolymers used in this study were in excellent agreement with 1H-NMR results.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 23 (1994), S. 203-207 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Submicrometer phase quantitative analysis is always a challenging problem for electron beam microanalysis because the phase is smaller than the electron beam and the specimen interaction volume. In order to obtain more accurate composition information, other analytical techniques need to be used to clarify the elements present and characterize the valence state of major elements in that submicrometer phase In this study, the electron probe microanalyzer (EPMA) was used to determine the contamination phase in the tungsten carbide-cobalt ceramic system. The average size of the contamination phase was approximately 0.5 μm in diameter. The chemical composition of the contamination phase was elucidated by combining results from x-ray mapping, valence state determination and EPMA quantitative analysis data. The effect of the contamination phase in the tungsten carbide-cobalt ceramic system is also discussed.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    X-Ray Spectrometry 23 (1994), S. 272-277 
    ISSN: 0049-8246
    Keywords: Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Physics
    Notes: Owing to improvements in impregnation techniques, the impregnation of copper compounds into a zeolite framework to form copper zeolite catalysts results in more uniformly distributed and finer (nanoscale size) copper-containing particles. In order to determine the oxidation state of copper in a copper zeolite catalyst, a method utilizing the X-ray absorption-induced (absorption edge/self-absorption) effect was developed using electron probe microanalysis. This method can provide oxidation state information that is not possible with traditional quantitative microanalysis owing to the electron beam and specimen interaction volume. The advantages and limitations of this method are discussed.
    Additional Material: 4 Ill.
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  • 4
    Publication Date: 2016-02-20
    Description: ABSTRACT Acute lung injury (ALI) is a serious inflammatory disorder which remains the primary cause of incidence and mortality in patients with acute pulmonary inflammation. However, there is still no effective medical strategy available clinically for the improvement of ALI. Wogonin, isolated from roots of Scutellaria baicalensis Georgi, is a common medicinal herb which presents biological and pharmacological effects, including antioxidation, anti-inflammation, and anticancer. Preadministration of wogonin inhibited not only lung edema but also protein leakage into the alveolar space in murine model of lipopolysaccharide (LPS)-induced ALI. Moreover, wogonin not only reduced the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX)−2 but also inhibited the phosphorylation of mitogen-activated protein kinase (MAPK) induced by LPS. We further found wogonin inhibited the phosphorylation of p38 MAPK and JNK at a concentration lower than ERK. In addition, inhibition of lung edema, protein leakage, expression of iNOS and COX-2, and phosphorylation of p38 MAPK and JNK were all observed in a parallel concentration-dependent manner. These results suggest that wogonin possesses potential protective effect against LPS-induced ALI via downregulation of iNOS and COX-2 expression by blocking phosphorylation of p38 MAPK and JNK. © 2016 Wiley Periodicals, Inc. Environ Toxicol, 2016.
    Print ISSN: 1520-4081
    Electronic ISSN: 1522-7278
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by Wiley-Blackwell
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  • 5
    Publication Date: 2016-09-18
    Description: Valproic acid (VPA), with inhibition activity mainly towards histone deacetylase (HDAC) and Glycogen Synthase Kinase (GSK)-3, and lithium, with inhibition activity mainly toward GSK-3, are both prescribed in clinical as mood-stabilizers and anticonvulsants for the control of bipolar disorder. This study aims to compare the immuno-modulation activities of VPA and lithium, especially on the differentiation and functions of dendritic cells (DC). Our data show that treatment with VPA or lithium effectively alleviated the severity of collagen-induced arthritis triggered by LPS in mice. Both agents reduced the serum level of IL-6 and IL-10 after LPS challenge in mice. VPA and lithium both induce significant down-regulation of group I CD1 expression and secretion of IL-6 during differentiation of human monocyte-derived immature DC, while they differ in the induction of CD83 and CD86 expression, secretion of IL-8, IL-10, and TNF-α. Upon stimulation of immature DC with LPS, VPA and lithium both reduced the secretion of IL-6 and TNF-α. However, only lithium significantly increased the production of IL-10, while VPA increased the production of IL-8 but substantially reduce the secretion of IL-10 and IL-23. Treatment with VPA resulted in a reduced capacity of LPS-stimulated DC to promote the differentiation of T helper 17 cells that are critical in the promotion of inflammatory responses. Taken together, our results suggest that VPA and lithium may differentially modulate inflammation through regulating the capacity of DC to mediate distinct T cell responses, and they may provide a complementary immunomodulatory effects for the treatment of inflammation-related diseases. This article is protected by copyright. All rights reserved
    Electronic ISSN: 1097-4652
    Topics: Biology , Medicine
    Published by Wiley-Blackwell
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  • 6
    Publication Date: 2016-09-09
    Description: ABSTRACT Cells switch to anaerobic glycolysis when there is a lack of oxygen during brain ischemia. Extracellular pH thus drops and such acidosis causes neuronal cell death. The fate of astrocytes, mechanical and functional partners of neurons, in acidosis is less studied. In this report we investigated the signaling in acidosis-challenged rat cortical astrocytes and whether these signals were related to mitochondrial dysfunction and cell death. Exposure to acidic pH (6.8, 6.0) caused Ca 2+ release and influx, p38 MAPK activation and Akt inhibition. Mitochondrial membrane potential was hyperpolarized after astrocytes were exposed to acidic pH as soon as 1 h and lasted for 24 h. Such mitochondrial hyperpolarization was prevented by SC79 (an Akt activator) but not by SB203580 (a p38 inhibitor) nor by cytosolic Ca 2+ chelation by BAPTA, suggesting that only the perturbation in Akt signaling was causally related to mitochondrial hyperpolarization. SC79, SB203580 and BAPTA did not prevent acidic pH-induced cell death. Acidic pH suppressed ROS production, thus ruling out the role of ROS in cytotoxicity. Interestingly, pH 6.8 caused an increase in ADP/ATP ratio and apoptosis; pH 6.0 caused a further increase in ADP/ATP ratio and necrosis. Therefore, astrocyte cell death in acidosis did not result from mitochondrial potential collapse; in case of acidosis at pH 6.0, necrosis might partly result from mitochondrial hyperpolarization and subsequent suppressed ATP production. This article is protected by copyright. All rights reserved
    Electronic ISSN: 0091-7419
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Published by Wiley-Blackwell
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  • 7
    Publication Date: 2017-06-21
    Description: Our previous hybrid simulation [ Shi et al. , 2013] under a radial interplanetary magnetic field (IMF) and a supercritical solar wind Mach number has shown that foreshock compressional waves originated from the quasi-parallel (Q-∥) shock are mode converted to kinetic Alfvén waves (KAWs) at the Alfvén resonance surface of the subsolar magnetopause. In this paper, three-dimensional global dayside mode conversion is investigated for cases under various solar wind conditions using the global hybrid model. The global patterns and propagations of KAWs are distinguished and presented. Under a near-critical Mach number ( M A =3), KAW structures due to mode conversion exhibit a feature of broader excitation regions in the magnetopause boundary layer (MPBL) compared to super-critical Mach number ( M A =5) shocks. For cases with an oblique IMF with supercritical Mach numbers ( M A =5), the amplitude of magnetosheath compressional waves is larger at the quasi-parallel shock (Q-∥) than at the quasi-perpendicular (Q-⊥) shock. Downstream of the Q-∥ shock, there is a general trend that the perturbations of density ( N ) and magnetic field ( B ) change from predominantly in-phase in the magnetosheath to anti-phase near the MPBL. While downstream of the Q-⊥ shock, an anti-phase relation between N and B is dominant throughout the magnetosheath and magnetopause except near the shock transition. The compressional drivers are found to reach an extended region of the magnetopause due to the combined effects of wave propagation in the plasma frame and flow convection, leading to a broad region of mode conversion at the magnetopause. Subsequently, the resulting KAWs can be carried to the regions downstream of the Q-⊥ shock owing to the ïňĆow convection at the magnetopause. The KAWs propagate poleward along the geomagnetic field lines and meanwhile are carried tailward by the ambient flows, and they are more intense in the downstream of Q-∥ shocks than downstream of Q-⊥ shocks.
    Print ISSN: 0148-0227
    Topics: Geosciences , Physics
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  • 8
    Publication Date: 2013-08-30
    Description: Q-ball imaging (QBI) is an imaging technique that is capable of resolving intravoxel fiber crossings; however, the signal readout based on echo-planar imaging (EPI) introduces geometric distortions in the presence of susceptibility gradients. This study proposes an imaging technique that reduces susceptibility distortions in QBI by short-axis PROPELLER EPI acquisition. Conventional QBI and PROPELLER QBI data were acquired from two 3T MR scans of the brains of five healthy subjects. Prior to the PROPELLER reconstruction, residual distortions in single-blade low-resolution b0 and diffusion-weighted images (DWIs) were minimized by linear affine and nonlinear diffeomorphic demon registrations. Subsequently, the PROPELLER keyhole reconstruction was applied to the corrected DWIs to obtain high-resolution PROPELLER DWIs. The generalized fractional anisotropy and orientation distribution function maps contained fewer distortions in PROPELLER QBI than in conventional QBI, and the fiber tracts more closely matched the brain anatomy depicted by turbo spin-echo (TSE) T 2 -weighted imaging (T2WI). Furthermore, for fixed T E , PROPELLER QBI enabled a shorter scan time than conventional QBI. We conclude that PROPELLER QBI can reduce susceptibility distortions without lengthening the acquisition time and is suitable for tracing neuronal fiber tracts in the human brain. Copyright © 2013 John Wiley & Sons, Ltd. This study employed the short-axis PROPELLER EPI technique in conjunction with data-sharing PROPELLER reconstruction to obtain QBI data with reduced susceptibility distortions. The results showed that PROPELLER EPI with affine + demon registrations substantially reduces the susceptibility distortions in PROPELLER EPI. As compared with conventional QBI, the GFA, ODF, and fiber tracts in PROPELLER QBI more closely match their anatomical locations in distortion-free TSE T2WI.
    Print ISSN: 0952-3480
    Electronic ISSN: 1099-1492
    Topics: Medicine
    Published by Wiley-Blackwell
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  • 9
    Publication Date: 2013-05-10
    Description: Consumption of fructose has been linked to the development of metabolic syndrome, whereas the cardiomyopathic changes and cardiac apoptosis of dietary high-fructose intake have not yet been clarified. The purpose of this study was to evaluate the effects of high-fructose on cardiac apoptotic and survival pathways. Thirty-two Wistar rats were randomly divided into a control group (CON), which received a standard chow diet, and a fructose-induced metabolic syndrome group (FIMS), which received a 50% fructose-content diet for 13 weeks. Histopathological analysis, TUNEL assays and Western blotting were performed on the excised hearts from both groups. The blood pressure, glucose, insulin, triglyceride and cholesterol levels were significantly increased in the FIMS group, compared with the CON group. The abnormal myocardial architecture, enlarged interstitial space and increased cardiac TUNEL-positive apoptotic cells were observed in the FIMS group. The TNF- α , TNF receptor 1, Fas ligand, Fas receptor, FADD, and activated caspase-3 and 8 protein levels (Fas pathway) and the Bax, Bak, Bax/Bcl-2, Bak/Bcl-xL, cytosolic cytochrome c , and activated caspase-3 and nine protein levels (mitochondria pathway) were increased in the FIMS group compared with those in the CON group. The IGFI, IGFI-R, p-PI3K, p-Akt, Bcl-2 and Bcl-xL protein levels (survival pathway) were all significantly decreased in the FIMS group compared with those in the CON group. High-fructose intake elevated blood pressure and glucose levels; moreover, high-fructose diet activated cardiac Fas-dependent and mitochondria-dependent apoptotic pathways and suppressed the survival pathway, which might provide one possible mechanism for developing heart failure in patients with metabolic syndrome. Copyright © 2013 John Wiley & Sons, Ltd.
    Print ISSN: 0263-6484
    Electronic ISSN: 1099-0844
    Topics: Biology , Medicine
    Published by Wiley-Blackwell
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  • 10
    Publication Date: 2014-06-29
    Description: Testicular nuclear receptor 4 (TR4) plays protective roles from oxidative stress and DNA damage and might contribute to aging. Our recent clinical tumor tissue staining results showed higher expression of TR4 in prostate cancer (PCa) patients with high Gleason scores compared to the tissues with the low Gleason scores. In vitro migration/invasion assays after manipulation of the TR4 expression in PCa cells showed that TR4 promoted PCa cells migration/invasion. Mechanism dissection found that the CCL2/CCR2 axis plays the key role in the mediation of TR4-promoted PCa cells migration/invasion. Chromatin immunoprecipitation and Luciferase assays further confirmed TR4 modulation of CCL2 at the transcriptional level, and addition of the CCR2 antagonist led to interruption of the TR4-enhanced PCa cells migration/invasion. Finally, the orthotopic xenografted mice studies using the luciferase expressing CWR22Rv1 cells found that TR4 enhanced PCa metastasis and this increased metastasis was reversed when the CCR2 antagonist was injected into the mice. Together, these in vitro and in vivo results revealed a positive role of TR4 in PCa metastasis and demonstrated CCL2/CCR2 signaling as an important mediator in exerting TR4 action. This finding suggests that TR4 may represent a biomarker related to PCa metastasis and/or targeting the TR4-CCL2/CCR2 axis may become a new therapeutic approach to battle PCa metastasis. © 2014 Wiley Periodicals, Inc.
    Print ISSN: 0020-7136
    Electronic ISSN: 1097-0215
    Topics: Biology , Medicine
    Published by Wiley-Blackwell
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