Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
Language
Year
  • 1
    Language: English
    In: Plant and Soil, Feb, 2006, Vol.280(1), p.209
    Description: Byline: Fabian Jaeger (1), Elisabeth Grohmann (2), Gabriele E. Schaumann (1) Keywords: [.sup.1]H NMR relaxometry; extracellular polymeric substances (EPS); soil microorganisms; soil organic matter (SOM) Abstract: [.sup.1]H NMR relaxometry is applied for the investigation of pore size distributions in geological substrates. The transfer to humous soil samples requires the knowledge of the interplay between soil organic matter, microorganisms and proton relaxation. The goal of this contribution is to give first insights in microbial effects in the 1.sup.H NMR relaxation time distribution in the course of hydration of humous soil samples. We observed the development of the transverse relaxation time distribution of the water protons after addition of water to air dried soil samples. Selected samples were treated with cellobiose to enhance microbial activity. Besides the relaxation time distribution, the respiratory activity and the total cell counts were determined as function of hydration time. Microbial respiratory activities were 2--15 times higher in the treated samples and total cell counts increased in all samples from 1x10.sup.9 to 5x10.sup.9 cells g.sup.-1 during hydration. The results of 1.sup.H NMR relaxometry showed tri-, bi- and mono-modal relaxation time distributions and shifts of peak relaxation times towards lower relaxation times of all investigated soil samples during hydration. Furthermore, we found lower relaxation times and merging of peaks in soil samples with higher microbial activity. Dissolution and hydration of cellobiose had no detectable effect on the relaxation time distributions during hydration. We attribute the observed shifts in relaxation time distributions to changes in pore size distribution and changes in spin relaxation mechanisms due to dissolution of organic and inorganic substances (e.g. Fe.sup.3+, Mn.sup.2+), swelling of soil organic matter (SOM), production and release of extracellular polymeric substances (EPS) and bacterial association within biofilms. Author Affiliation: (1) Department of Environmental Chemistry, University of Technology Berlin, Sekr. KF 3, Strasse des 17. Juni 135, D-10623, Berlin, Germany (2) Department of Environmental Microbiology, University of Technology Berlin, Sekr. FR 1--2, Franklinstrasse 28/29, D-10587, Berlin, Germany Article History: Registration Date: 12/09/2005 Received Date: 25/05/2005 Accepted Date: 08/09/2005
    Keywords: Microbiology ; Diagnostic Imaging ; Nuclear Magnetic Resonance
    ISSN: 0032-079X
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: The Angle orthodontist, September 2017, Vol.87(5), pp.672-680
    Description: To quantify treatment-related changes in peridental bone height and thickness in orthodontic patients. Cone-beam computed tomographs (CBCTs) of 43 patients (24 female, 19 male; mean age: 25 years, 5 months) who underwent orthodontic treatment with multibracket appliances for at least 1 year were chosen for retrospective evaluation. Dehiscence depth and changes in bone width and tooth inclination were determined for 954 teeth. There was a significant decrease in peridental bone height (dehiscence; -0.82 ± 1.47 mm) and bone thickness (-0.56 ± 0.7 and -0.69 ± 0.9 mm at 5 mm and 10 mm apical to the CEJ, respectively) during treatment (P 2 mm before treatment. In 90% of these patients, at least one tooth was affected. The maxillary canines and all mandibular teeth showed a higher risk for vestibular bone loss. Treatment changes in tooth inclination were correlated with horizontal bone loss. Based on these results, it seems reasonable to recommend that peridental bone in orthodontic patients older than 30 be evaluated on a routine basis due to the risk of increased vertical bone loss. Ninety percent of patients younger than 30 showed reduced bone height (dehiscence) of the periodontium of at least one tooth.
    Keywords: Cone-Beam Computed Tomography ; Multibracket ; Peridental Bone ; Alveolar Bone Loss -- Etiology ; Alveolar Process -- Diagnostic Imaging ; Cone-Beam Computed Tomography -- Methods ; Orthodontics, Corrective -- Adverse Effects ; Tooth Movement Techniques -- Adverse Effects
    ISSN: 00033219
    E-ISSN: 1945-7103
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: German
    In: ZWF Zeitschrift für wirtschaftlichen Fabrikbetrieb, 03/28/2018, Vol.113(3), pp.142-147
    Description: Lean Production Systems (LPS) are state of the art in today's production companies. By now, it is increasingly important to not only focus on Lean tools and methods, but also on substantial leadership styles, such as Lean Leadership, that strengthen the application of those methods. Sustainable LPS success mostly depends on leadership efforts that focus on the people at the shopfloor level. Those workers need to be qualified to independently solve problems occuring in their work routines in order to significantly participate in the company's continous improvement process. Therefore, Shopfloor Management is one of the most important methods in LPS. The implementation of the method as well as its benefits are well-known in literature. However, there is no approach existing that allows the evaluation of the quality of the Shopfloor Management initiative. Especially when it comes to the implementation of the method, the simultaneous identification of weak points can help to foster the sustainable establishment of the Shopfloor Management routine. In this article, a novel approach for the qualitative assessment of Shopfloor Management initiatives is presented. Moreover, the success of the so-called Braunschweiger Shopfloor Management Assessment is validated by presenting a practical example.
    Keywords: Qualitative Analyse ; Problemlösung ; Kontinuierlicher Verbesserungsprozess ; Produktionssystem ; Stand Der Technik ; Schlanke Fertigung ; Mitarbeiterführung ; Führungsstil ; Schwachstelle (Organisation) ; Engineering;
    ISSN: 0947-0085
    E-ISSN: 2511-0896
    Source: CrossRef
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: The Open Magnetic Resonance Journal, 07/06/2010, Vol.3(2), pp.15-26
    ISSN: 18747698
    Source: Bentham Science (via CrossRef)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Soil Science Society of America journal, 2008, Vol.72(6), pp.1694-1707
    Description: Proton nuclear magnetic resonance (1H NMR) relaxometry has been used to analyze pore size distributions of wet porous samples. To make this method applicable to soil samples, knowledge about contribution from the soil solution to the total proton relaxation is needed. We extracted soil solutions from nine soil samples and determined transverse proton relaxation rates, the concentration of Fe, Mn, and total organic C (TOC), and the pH of the solutions. The effects of Fe, Mn, and TOC on the proton relaxation in the soil solution were compared with those of dissolved Fe2+, Fe3+, and Mn2+ and of glucose, D-cellobiose, potassium hydrogen phthalate, sodium alginate, and agar in model solutions. Proton relaxation rates in the soil solutions were up to 20 times larger than in pure water, which was mainly due to dissolved Fe(III) and Mn(II) species. The relaxivities of Fe and Mn in soil solution were reduced to 40 and 70% compared with Fe(III) and Mn(II) in a model solution, respectively. Smaller relaxivities were primarily due to the formation of metal-organic complexes. We conclude that the proton relaxation in soil samples is generally accelerated by the soil solution, and its contribution must be considered to estimate pore sizes from relaxation times. By using the calculated relaxivities of Fe and Mn in soil solution, the contribution of the soil solution to the total proton relaxation can be estimated from the Fe and Mn concentration in the soil solution. ; Includes references ; p. 1694-1707.
    Keywords: Soil Organic Carbon ; Goethite ; Cellobiose ; Soil Solution ; Agar ; Soil Pore System ; Manganese ; Ions ; Iron ; Colloids ; Sampling ; Alginates ; Glucose ; Extracts ; Chemical Concentration ; Chemical Composition ; Nuclear Magnetic Resonance Spectroscopy ; Montmorillonite ; Sodium Alginate ; Pore Size Distribution ; Proton Relaxation ; Potassium Hydrogen Phthalate
    ISSN: 0361-5995
    E-ISSN: 14350661
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: The Open Magnetic Resonance Journal, 07/06/2010, Vol.3(2), pp.27-45
    ISSN: 18747698
    Source: Bentham Science (via CrossRef)
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Journal of Orofacial Orthopedics / Fortschritte der Kieferorthopädie, 2018, Vol.79(5), pp.309-319
    Description: To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1007/s00056-018-0144-2 Byline: Stephan Christian Mohlhenrich (1), Fabian Jager (1), Andreas Jager (2), Pascal Schumacher (3), Michael Wolf (1), Ulrike Fritz (1), Christoph Bourauel (4) Keywords: Fixed retainer; Orthodontic wires; CAD/CAM; Nickel titanium; Plastic deformation; Retainer; Orthodontische Drahte; CAD/CAM; Nickel-Titan; Plastische Verformung Abstract: Purpose This study aimed to determine and compare the mechanical properties of novel CAD/CAM(computer-aided design/manufacturing)-individualized nickel-titanium (NiTi) and conventional twisted wires. Methods Seven NiTi wires (angular, 0.20a[macron]x0.20a[macron]mm up to 0.50a[macron]x0.50a[macron]mm) and two twisted steel wires (round, 0.40a[macron]mm and 0.44a[macron]mm) were investigated in three-point (3PBT) and four-point bending tests (4PBT) using the Orthodontic Measurement and Simulation System. All wires were loaded up to a distance of 3.3a[macron]mm, and resulting forces were measured. Additionally, in the biomechanical test (BMT), CAD/CAM-individualized NiTi retainers (0.35a[macron]x0.35a[macron]mm) were subjected to intrusive and extrusive deformation of 0.1, 0.2, and 0.4a[macron]mm. Results For twisted wires, typical plastic deformations were found in 3PBT (0.40a[macron]mm: 0.3a[macron]mm 0.44a[macron]mm: 0.4a[macron]mm), and maximum resulting forces for these reached 1.3a[macron]N and 3.2a[macron]N for the 0.40a[macron]mm and 0.44a[macron]mm wires, respectively. Corresponding values in the 4PBT totaled 0.8a[macron]N for the 0.40a[macron]mm and 1.9a[macron]N for the 0.44a[macron]mm twisted wire. The NiTi samples showed plastic deformations in the 3PBT for the 0.25a[macron]x0.25a[macron]mm dimension and in 4PBT for the 0.35a[macron]mma[macron]x0.35a[macron]mm version. At a deflection of 1.5a[macron]mm, both tests revealed significantly different forces for the NiTi wires of different dimensions (pa[macron]a[currency]0.001). In the BMT, no remarkable loading plateau or plastic deformation was observed. The resulting forces were significantly higher for extrusive than for intrusive deformation (pa[macron]a[currency]0.001). Conclusions Individualized NiTi retainers feature specific elasticity and dimensional stability, and more deflection is necessary to achieve permanent deformations. The CAD/CAM production process did not significantly influence the biomechanical properties of the NiTi wires. Abstract (German): Ziele Ziel dieser Studie war es, die mechanischen Eigenschaften von neuartigen CAD/CAM("computer aided design/manufacturing")-individualisierten Nickel-Titan (NiTi) und konventionellen verdrillten Drahten zu bestimmen und zu miteinander zu vergleichen. Methoden Sieben NiTi-Drahte (eckig, 0,20a[macron]x0,20 bis zu 0,50a[macron]x0,50a[macron]mm) und 2 verdrillte Stahldrahte (rund, 0,40 und 0,44a[macron]mm) wurden in Drei- (3PBT) und Vierpunktbiegetests (4PBT) mit dem kieferorthopadischen Mess- und Simulationssystem (OMSS) untersucht. Alle Drahte erfuhren eine maximale Auslenkung von 3,3a[macron]mm, die resultierende Kraft wurde gemessen. Zusatzlich wurden CAD/CAM-individualisierte NiTi-Retainer (0,35a[macron]x0,35a[macron]mm) in einem biomechanischen Test (BMT) einer intrusiven und extrusiven Auslenkung von 0,1, 0,2 und 0,4a[macron]mm ausgesetzt. Ergebnisse Fur die verdrillte Drahte wurden typische plastische Verformungen in 3PBT (0,40a[macron]mm: 0,3a[macron]mm 0,44a[macron]mm: 0,4a[macron]mm) festgestellt. Dabei lagen die maximal resultierende Krafte im 3PBT bei 1,3a[macron]N fur den 0,40-mm- und bei 3,2a[macron]N fur den 0,44-mm-Draht, im 4PBT bei 0,8a[macron]N fur den 0,40-mm- und 1,9a[macron]N fur den 0,44-mm-Draht. Plastische Verformungen der NiTi-Drahte zeigten sich im 3PBT ab einer Gro[sz]e von 0,25a[macron]x0,25a[macron]mm und in 4PBT ab 0,35a[macron]x0,35a[macron]mm. Ab einer Auslenkung von 1,5a[macron]mm wurden in beiden Tests signifikante Kraftunterschiede fur NiTi-Drahte unterschiedlicher Gro[sz]e festgestellt (pa[macron]a[currency]0,001). Im BMT traten weder ein Belastungsplateau noch plastische Verformungen auf. Die resultierenden Krafte waren signifikant hoher bei extrusiver als bei intrusiver Verformung (pa[macron]a[currency]0,001). Schlussfolgerungen Individualisierte NiTi-Retainer zeichnen sich durch besondere Elastizitat und Formstabilitat aus. Erst gro[sz]ere Auslenkungen fuhren zu dauerhaften Verformungen. Der CAD/CAM-Herstellungsprozess hat keinen signifikanten Einfluss auf die biomechanischen Eigenschaften der NiTi-Drahte. Author Affiliation: (1) 0000 0000 8653 1507, grid.412301.5, Department of Orthodontics and Dentofacial Orthopedics, University Hospital of the RWTH Aachen, Pauwelsstra[sz]e 30, 52074, Aachen, Germany (2) 0000 0001 2240 3300, grid.10388.32, Department of Orthodontics and Dentofacial Orthopedics, University of Bonn, Welschnonnenstra[sz]e 17, 53111, Bonn, Germany (3) Private practice, Cologne, Germany (4) 0000 0001 2240 3300, grid.10388.32, Department of Oral Technology, University of Bonn, Welschnonnenstra[sz]e 17, 53111, Bonn, Germany Article History: Registration Date: 15/06/2018 Received Date: 21/12/2017 Accepted Date: 11/06/2018 Online Date: 16/07/2018 Article note: Stephan Christian Mohlhenrich and Fabian Jager share first authorship.
    Keywords: Fixed retainer ; Orthodontic wires ; CAD/CAM ; Nickel titanium ; Plastic deformation
    ISSN: 1434-5293
    E-ISSN: 1615-6714
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Plant and Soil, 2006, Vol.280(1), pp.209-222
    Description: 1 H NMR relaxometry is applied for the investigation of pore size distributions in geological substrates. The transfer to humous soil samples requires the knowledge of the interplay between soil organic matter, microorganisms and proton relaxation. The goal of this contribution is to give first insights in microbial effects in the 1 H NMR relaxation time distribution in the course of hydration of humous soil samples. We observed the development of the transverse relaxation time distribution of the water protons after addition of water to air dried soil samples. Selected samples were treated with cellobiose to enhance microbial activity. Besides the relaxation time distribution, the respiratory activity and the total cell counts were determined as function of hydration time. Microbial respiratory activities were 2–15 times higher in the treated samples and total cell counts increased in all samples from 1×10 to 5×10 cells g during hydration. The results of H NMR relaxometry showed tri-, bi- and mono-modal relaxation time distributions and shifts of peak relaxation times towards lower relaxation times of all investigated soil samples during hydration. Furthermore, we found lower relaxation times and merging of peaks in soil samples with higher microbial activity. Dissolution and hydration of cellobiose had no detectable effect on the relaxation time distributions during hydration. We attribute the observed shifts in relaxation time distributions to changes in pore size distribution and changes in spin relaxation mechanisms due to dissolution of organic and inorganic substances (e.g. Fe, Mn), swelling of soil organic matter (SOM), production and release of extracellular polymeric substances (EPS) and bacterial association within biofilms.
    Keywords: H NMR relaxometry ; extracellular polymeric substances (EPS) ; soil microorganisms ; soil organic matter (SOM)
    ISSN: 0032-079X
    E-ISSN: 1573-5036
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Research Projects in Dry Eye Syndrome, 2010, Vol.45, p.12-15
    Description: Abstract Several diseases concomitant with L-arginine deficiency (diabetes, chronic kidney failure, psoriasis) are significantly associated with dry eye syndrome. One important factor that has so far been neglected is the y + transporter. In humans, y + accounts for nearly 80% of arginine transport, exclusively carrying the cationic amino acids L-arginine, L-lysine and L-ornithine. y + is represented by CAT(cationic amino acid transporter) proteins. L-arginine is a precursor of the moisturizer urea, which has been used in the treatment of dry skin diseases. Although urea has also been shown to be part of the tear film, little attention has been paid to it in this role. Moreover, L-arginine and L-lysine are major components contributing to synthesis of the antimicrobially active β-defensins induced under dry eye conditions. The first results have demonstrated that transport of L-arginine and L-lysine into epithelial cells is limited by the y + transporter at the ocular surface. Copyright © 2010 S. Karger AG, Basel
    Keywords: Amino Acid Transport Systems, Basic -- Physiology ; Dry Eye Syndromes -- Metabolism ; Beta-Defensins -- Physiology;
    ISBN: 978-3-8055-9418-9
    ISSN: 0250-3751
    E-ISSN: 1662-2790
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Journal of the American Chemical Society, 11 March 2015, Vol.137(9), pp.3308-17
    Description: The first highly water-soluble perylene-calix[4]arene hybrid with the calixarene scaffold acting as a structure-determining central platform is presented. In this tetrahedrally shaped amphiphilic architecture the hydrophilic and hydrophobic subunits are oriented at the opposite side of the calixarene platform. The hydrophobic part contains the two perylene diimide moieties, which enable strong π-π interactions in self-assembly processes. Two hydrophilic Newkome-type dendrons provide sufficient water solubility at slightly basic conditions. The tetrahedrally shaped amphiphile displays an unprecedented aggregation behavior down to concentrations as low as 10(-7) mol L(-1). The intriguing self-assembly process of the compound in water as well as under changed polarity conditions, achieved by addition of THF, could be monitored by the complemented use of cryogenic transmission electron microscopy (cryo-TEM), UV-vis spectroscopy, and fluorescence spectroscopy. Molecular-dynamics and molecular modeling simulations helped in understanding the interplay of supramolecular and optical behavior.
    Keywords: Calixarenes -- Chemistry ; Perylene -- Chemistry
    ISSN: 00027863
    E-ISSN: 1520-5126
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages