GLORIA

GEOMAR Library Ocean Research Information Access

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Photopolymerization of N-substituted phenyl maleimide initiated with N,N-dimethyl-4-toluidine (1997)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 643-650 
    Details
    ISSN: 0887-624X
    Keywords: photopolymerization of N-substituted phenyl maleimides ; N,N-dimethyl-4-Toluidine ; exciplex ; radical intermediate ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Several N-phenyl maleimides with different p-substituents have been synthesized from the maleic anhydride and relevant aromatic amine. In the presence of N,N-dimethyl-4-toluidine (DMT), the N-substituted phenyl maleimide (4-XPhMIs) could be polymerized under UV irradiation. It was observed that a new absorption appeared on the UV-Vis spectrum of the mixture solution of 4-XPhMI and DMT, which reveals the formation of charge-transfer complex in the ground state. It was found that the fluorescence of DMT was quenched by 4-XPhMI and the quenching constant of 4-XPhMI, obtained from the Stern-Volmer plot, increases with the electron-deficiency of ethylene double bond of 4-XPhMI. The dynamic quenching of the fluorescence of DMT by 4-XPhMI suggests the formation of exciplex in excited state between DMT and 4-XPhMI. The radicals formed in the systems have been detected by spin-trapping techniques and electron paramagnetic resonance (EPR) spectrometer. Based on all of these results, it has been proposed that the initiation process of the polymerization involves the formation of exciplex and the initial radicals were produced by proton-transfer in the exciplex from DMT to 4-XPhMI. © 1997 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 2
    Electronic Resource
    Electronic Resource
    The electropolymerization of poly(styrene-co-4-carboxyphenyl maleimide) coatings onto steel (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 62 (1996), S. 1303-1312 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Electropolymerization can be used to produce uniform and pin-hole free coatings on surfaces of complex shapes, due to the intrinsic characteristic of the process. In this article, the electrocopolymerization behavior of 4-carboxyphenyl maleimide (4CPMI) with styrene onto a steel surface is reported. The polymerization mechanism is by free radical, as might be expected for an aqueous reaction environment. Experimental results suggest that initially a charge transfer complex forms between styrene and 4CPMI, which is much more reactive than either of the two monomers. Alternating copolymers are always obtained at low conversion, even with significant changes in the monomer feed compositions. Because of the incorporation of rigid imide rings into the copolymer backbone, the coating formed has very good thermal properties and is thus a potential candidate for high-temperature applications. Furthermore, the copolymer dielectric constant is comparable to that of commercial polyimides, making it attractive for use in electrical and electronic insulation applications. © 1996 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 3
    Electronic Resource
    Electronic Resource
    Some Synthetic Studies Related to Perylenequinones (1993)
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1993 (1993), S. 35-41 
    Details
    ISSN: 0170-2041
    Keywords: Fungus pigments ; Perylenequinones, synthesis of ; Selenium dioxide oxidation ; Ullmann coupling ; Double coupling of 1,2-naphthalenediols ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two closely related routes to dimethyl 3,10-dihydro-2,11-dihydroxy-4,6,7,9-tetramethoxy-3,10-dioxo-1,12-perylenediacetate (10), one involving Ullmann phenol coupling and the other by double oxidative coupling are described. Regioselective demethylation of 10 followed by methylation or vice versa yields dimethyl 3,10-dihydro-4,9-dihydroxy-2,6,7,11-tetramethoxy-3,10-dioxo-1,12-perylenediacetate (22) which, except for its side chains, structurally resembles some of the natural perylenequinones.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/jlac.199319930107
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    facet.materialart.
    Unknown
    The PMIP4 contribution to CMIP6 – Part 4: Scientific objectives and experimental design of the PMIP4-CMIP6 Last Glacial Maximum experiments and PMIP4 sensitivity experiments (2017)
    Copernicus Publications (EGU)
    In:  Geoscientific Model Development, 10 (11). pp. 4035-4055.
    Details
    Publication Date: 2020-02-06
    Description: The Last Glacial Maximum (LGM, 21 000 years ago) is one of the suite of paleoclimate simulations included in the current phase of the Coupled Model Intercomparison Project (CMIP6). It is an interval when insolation was similar to the present, but global ice volume was at a maximum, eustatic sea level was at or close to a minimum, greenhouse gas concentrations were lower, atmospheric aerosol loadings were higher than today, and vegetation and land-surface characteristics were different from today. The LGM has been a focus for the Paleoclimate Modelling Intercomparison Project (PMIP) since its inception, and thus many of the problems that might be associated with simulating such a radically different climate are well documented. The LGM state provides an ideal case study for evaluating climate model performance because the changes in forcing and temperature between the LGM and pre-industrial are of the same order of magnitude as those projected for the end of the 21st century. Thus, the CMIP6 LGM experiment could provide additional information that can be used to constrain estimates of climate sensitivity. The design of the Tier 1 LGM experiment (lgm) includes an assessment of uncertainties in boundary conditions, in particular through the use of different reconstructions of the ice sheets and of the change in dust forcing. Additional (Tier 2) sensitivity experiments have been designed to quantify feedbacks associated with land-surface changes and aerosol loadings, and to isolate the role of individual forcings. Model analysis and evaluation will capitalize on the relative abundance of paleoenvironmental observations and quantitative climate reconstructions already available for the LGM.
    Type: Article , PeerReviewed
    Format: text
    Format: archive
    DOI: 10.5194/gmd-10-4035-2017
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 5
    facet.materialart.
    Unknown
    The p73 G4C14-to-A4T14 polymorphism is associated with risk of lung cancer in the Han nationality of North China (2012)
    Wiley-Blackwell
    Details
    Publication Date: 2012-04-16
    Description: p73, a structural and functional homolog of p53, plays an important role in tumor carcinogenesis. Previous studies have suggested that the association between the p73 G4C14-to-A4T14 polymorphism and the risk of lung cancer, but the results have not been entirely consistent. We examined whether the p73 G4C14-to-A4T14 polymorphism was related to the risk of developing lung cancer in a Chinese population. The p73 G4C14-to-A4T14 polymorphism was genotyped in 293 lung cancer patients and 380 cancer-free controls of Han nationality in North China using PCR-RFLP. Multivariate logistic regression analysis was used to calculate adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs). We observed that compared with the GC/GC genotype, the genotypes containing AT allele (GC/AT + AT/AT genotypes) were associated with significantly increased susceptibility to lung cancer (OR, 1.48; 95% CI, 1.08–2.02; P  = 0.014). In addition, compared with the GC/GC genotype, the GC/AT genotype was also significantly associated with increased susceptibility to lung cancer (OR, 1.46; 95% CI, 1.06–2.02; P  = 0.046). Our findings suggest that the p73 G4C14-to-A4T14 polymorphism contributes to the risk of developing lung cancer in Chinese population. © 2012 Wiley Periodicals, Inc.
    Print ISSN: 0899-1987
    Electronic ISSN: 1098-2744
    Topics: Medicine
    Published by Wiley-Blackwell
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 6
    facet.materialart.
    Unknown
    Centennial- to millennial-scale monsoon changes since the last deglaciation linked to solar activities and North Atlantic cooling (2020)
    Copernicus Publications (EGU)
    Details
    Publication Date: 2023-02-08
    Description: Rapid monsoon changes since the last deglaciation remain poorly constrained due to the scarcity of geological archives. Here we present a high-resolution scanning X-ray fluorescence (XRF) analysis of a 13.5 m terrace succession on the western Chinese Loess Plateau (CLP) to infer rapid monsoon changes since the last deglaciation. Our results indicate that Rb∕Sr and Zr∕Rb are sensitive indicators of chemical weathering and wind sorting, respectively, which are further linked to the strength of the East Asian summer monsoon (EASM) and the East Asian winter monsoon (EAWM). During the last deglaciation, two cold intervals of the Heinrich event 1 and Younger Dryas were characterized by intensified winter monsoon and weakened summer monsoon. The EAWM gradually weakened at the beginning of the Holocene, while the EASM remained steady till 9.9 ka and then grew stronger. Both the EASM and EAWM intensities were relatively weak during the Middle Holocene, indicating a mid-Holocene climatic optimum. Rb∕Sr and Zr∕Rb exhibit an antiphase relationship between the summer and winter monsoon changes on a centennial timescale during 16–1 ka. Comparison of these monsoon changes with solar activity and North Atlantic cooling events reveals that both factors can lead to abrupt changes on a centennial timescale in the Early Holocene. During the Late Holocene, North Atlantic cooling became the major forcing of centennial monsoon events.
    Type: Article , PeerReviewed
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 7
    facet.materialart.
    Unknown
    PISM-LakeCC: Implementing an adaptive proglacial lake boundary into an ice sheet model (2020)
    Copernicus Publications (EGU)
    Details
    Publication Date: 2022-03-10
    Description: Geological records show that vast proglacial lakes existed along the land terminating margins of palaeo ice sheets in Europe and North America. Proglacial lakes impact ice sheet dynamics by imposing marine-like boundary conditions at the ice margin. These lacustrine boundary conditions include changes in the ice sheet’s geometry, stress balance and frontal ablation and therefore affect the entire ice sheet’s mass balance. This interaction, however, has not been rigorously implemented in ice sheet models. In this study, the implementation of an adaptive lake boundary into the Parallel Ice Sheet Model (PISM) is described and applied to the glacial retreat of the Laurentide Ice Sheet (LIS). The results show that the presence of proglacial lakes locally enhances the ice flow. Along the continental ice margin, ice streams and ice lobes can be observed. Lacustrine terminating ice streams cause immense thinning of the ice sheet’s interior and thus play a significant role in the demise of the LIS. Due to the presence of lakes, a process similar to the marine ice sheet instability causes the collapse of the ice saddle over Hudson Bay, which blocked drainage via the Hudson Strait. In control experiments without a lake model, Hudson Bay is still glaciated at the end of the simulation. Future studies should target the development of parametrizations that better describe the glacial-lacustrine interactions.
    Type: Article , PeerReviewed
    Format: text
    Format: text
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    OceanRep: Article in a Scientific Journal - peer-reviewed
  • 8
    facet.materialart.
    Unknown
    Crystallographic studies of SarV, a global regulator from Staphylococcus aureus (2015)
    Wiley-Blackwell
    Details
    Publication Date: 2015-08-08
    Description: SarV, a member of the SarA protein family, is a global transcriptional regulator which has been reported to be involved in the regulation of autolysis in Staphylococcus aureus . In this study, SarV from S. aureus was successfully cloned, expressed, purified and crystallized. X-ray diffraction data were collected to 2.10 Å resolution. The crystals of SarV belonged to the monoclinic space group P 2 1 , with unit-cell parameters a = 36.40, b = 119.64, c = 66.80 Å, α = γ = 90, β = 98.75°. The Matthews coefficient and the solvent content were estimated to be 2.57 Å 3  Da −1 and 52%, respectively, suggesting the presence of four molecules in the asymmetric unit. The results of size-exclusion chromatography (SEC) indicated that S. aureus SarV exists as a homodimer in solution. Unfortunately, the structure cannot be solved by molecular replacement because of the low sequence identity of S. aureus SarV to known structures. Further phase determination by selenomethionine single-wavelength anomalous dispersion (SAD) and the heavy-atom method is in progress.
    Electronic ISSN: 1744-3091
    Topics: Biology , Chemistry and Pharmacology , Geosciences , Physics
    Published by Wiley-Blackwell on behalf of International Union of Crystallography (IUCr).
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 9
    facet.materialart.
    Unknown
    Diffusion kurtosis MRI versus conventional diffusion-weighted imaging for evaluating inflammatory activity in Crohn's disease (2017)
    Wiley-Blackwell
    Details
    Publication Date: 2017-06-04
    Description: Purpose To assess the efficacy of diffusion kurtosis imaging (DKI) and to compare DKI-derived parameters with that of conventional diffusion-weighted imaging (DWI) for grading the inflammatory activity of Crohn's disease (CD). Materials and Methods In all, 38 patients with CD underwent 3T magnetic resonance enterography (MRE) with DKI (b values of 0–2000 s/mm 2 ). The inflammatory activity of the bowel segments was graded by magnetic resonance index of activity (MaRIA) as inactive (〈7), mild (≥7 and 〈11), or moderate-severe (≥11). Apparent diffusion for non-Gaussian distribution (D app ) and apparent kurtosis coefficient (K app ) on DKI as well as apparent diffusion coefficient (ADC) on DWI were compared. Results In all, 86 bowel segments including inactive (20), mild (19), and moderate-severe (47) CD were analyzed. The differences in K app , D app , and ADC among inactive, mild, and moderate-severe CD were significant (all P 〈 0.05). K app ( r = 0.862), D app ( r = −0.755), and ADC ( r = −0.713) correlated well with MaRIA in all segments. Stronger correlation with MaRIA in moderate-severe CD was found for K app ( r = 0.647) than that of D app ( r = −0.414) and ADC ( r = −0.580). Receiver operating characteristic (ROC) curve analysis showed high accuracy of K app , D app , and ADC for differentiating active from inactive CD (AUC: 0.953 for K app , 0.944 for D app , 0.907 for ADC) as well as differentiating inactive-mild from moderate-severe CD (AUC: 0.946 for K app , 0.887 for D app , 0.846 for ADC). The threshold K app of 0.731 allowed differentiation of active from inactive CD with 89.4% sensitivity and 95% specificity. Conclusion DKI of CD is clinically feasible and might be superior to conventional DWI for grading the inflammatory activity of CD. Level of Evidence : 2 Technical Efficacy : Stage 2 J. Magn. Reson. Imaging 2017.
    Print ISSN: 1053-1807
    Electronic ISSN: 1522-2586
    Topics: Medicine
    Published by Wiley-Blackwell
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
  • 10
    facet.materialart.
    Unknown
    Increased precipitation and weathering across the Paleocene-Eocene thermal maximum in central China (2016)
    Wiley-Blackwell
    Details
    Publication Date: 2016-05-22
    Description: Global warming during the Paleocene-Eocene Thermal Maximum (PETM) ∼55.5 million years ago (Ma) was associated with a massive release of carbon to the ocean-atmosphere system, as evidenced by a prominent negative carbon isotope excursion (CIE) and widespread dissolution of marine carbonates. The paleohydrologic response to the PETM warming has been studied worldwide; however, relevant records of environmental perturbation in Asia are lacking so far. Here we extend the record of this event in central China, a subtropical paleosetting, through geochemical and mineralogical analyses of lacustrine sediments. Geochemical indicators of authigenic carbonates – including molar Mg/Ca and Sr/Ca ratios – suggest an overall increased precipitation across the PETM, compatible with the disappearance of authigenic dolomite and the appearance of kaolinite in the strata. The relatively humid conditions persisted long after the carbon-cycle perturbation had stopped, implying that the transient hyper-greenhouse warming might have forced the regional climate system into a new climate state that was not easily reversed. Additionally, a gradual increase in chemical index of alteration (CIA) and the appearance of kaolinite are associated with the PETM, indicating an intensified silicate weathering and pedogenesis in the watershed in response to warmer and more humid climate. Our results corroborate the theory that an accelerated continental chemical weathering served as a negative feedback to sequester carbon and lower the atmospheric greenhouse-gas levels during the PETM. This article is protected by copyright. All rights reserved.
    Electronic ISSN: 1525-2027
    Topics: Chemistry and Pharmacology , Geosciences , Physics
    Published by Wiley-Blackwell on behalf of American Geophysical Union (AGU).
    Location Call Number Limitation Availability
    BibTip Others were also interested in ...
    PAPER CURRENT
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...