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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Complexation Properties of Maltosylated Hyperbranched Poly(ethylene imine)s in Solution and in Functional Hydrogels

Polikarpov, Nikita 11 December 2012 (has links)
Hyperbranched poly(ethylene imine) with Mw 5,000 and 25,000 Da and different degrees of substitution with maltose (PEI-Mal) was firstly described by Appelhans et al. Its biocompatibility and the potential to complex anionic molecules was demonstrated previously. In this study, the characterisation of host-guest interactions of PEI-Mal with various anionic water-soluble guest molecules with aromatic moieties in the structure (adenosine triphosphate, rose bengal, and acid red 26) in solution was provided. Also, a multicomponent drug@PEI-Mal@hydrogel system was achieved.
42

Promoting Electrocatalysis upon Aerogels

Cai, Bin, Eychmüller, Alexander 20 September 2019 (has links)
Electrocatalysis plays a prominent role in renewable energy conversion and storage, enabling a number of sustainable processes for future technologies. There are generally three strategies to improve the efficiency (or activity) of the electrocatalysts: (i) increasing the intrinsic activity of the catalyst itself; (ii) improving the exposure of active sites; and (iii) acceleratingmass transfer during catalysis (both reactants and products). These strategies are not mutually exclusive and can ideally be addressed simultaneously, leading to the largest improvements in activity. Aerogels, as featured by large surface area, high porosity, and self-supportability provide a platform that matches all the aforementioned criteria for the design of efficient electrocatalysts. The field of aerogel synthesis has seen much progress in recent years, mainly thanks to the rapid development of nanotechnology. Employing precursors with different properties enables the resulting aerogel with targeted catalytic properties and improved performances. This report demonstrates the design strategies of aerogel catalysts and reviews their performances for several electrochemical reactions. The common principles that govern electrocatalysis are further discussed for each category of reactions, thus serving as a guide to the development of future aerogel electrocatalysts.
43

Polymer self-assembly : adding complexity to mesostructures of diblock copolymers by specific interactions / Polymer self-assembly : adding complexity to mesostructures of diblock copolymers by specific interactions

Schlaad, Helmut January 2005 (has links)
In dieser Arbeit wurde die Rolle selektiver, nicht-kovalenter Wechselwirkungen bei der Selbstorganisation von Diblockcopolymeren untersucht. Durch Einführung elektrostatischer, dipolarer Wechselwirkungen oder Wasserstoffbrückenbindungen sollte es gelingen, komplexe Mesostrukturen zu erzeugen und die Ordnung vom Nanometerbereich auf größere Längenskalen auszuweiten. Diese Arbeit ist im Rahmen von Biomimetik zu sehen, da sie Konzepte der synthetischen Polymer- und Kolloidchemie und Grundprinzipien der Strukturbildung in supramolekularen und biologischen Systemen verbindet. Folgende Copolymersysteme wurden untersucht: (i) Blockionomere, (ii) Blockcopolymere mit chelatisierenden Acetoacetoxyeinheiten und (iii) Polypeptid-Blockcopolymere. / In this work, the basic principles of self-organization of diblock copolymers having the in¬herent property of selective or specific non-covalent binding were examined. By the introduction of electrostatic, dipole–dipole, or hydrogen bonding interactions, it was hoped to add complexity to the self-assembled mesostructures and to extend the level of ordering from the nanometer to a larger length scale. This work may be seen in the framework of biomimetics, as it combines features of synthetic polymer and colloid chemistry with basic concepts of structure formation applying in supramolecular and biological systems. The copolymer systems under study were (i) block ionomers, (ii) block copolymers with acetoacetoxy chelating units, and (iii) polypeptide block copolymers.
44

Early specific cognitive-behavioural psychotherapy in subjects at high risk for bipolar disorders: study protocol for a randomised controlled trial

Pfennig, Andrea, Leopold, Karolina, Bechdolf, Andreas, Correll, Christoph U., Holtmann, Martin, Lambert, Martin, Marx, Carolin, Meyer, Thomas D., Pfeiffer, Steffi, Reif, Andreas, Rottmann-Wolf, Maren, Schmitt, Natalie M., Stamm, Thomas, Juckel, Georg, Bauer, Michael 21 July 2014 (has links) (PDF)
Background: Bipolar disorders (BD) are among the most severe mental disorders with first clinical signs and symptoms frequently appearing in adolescence and early adulthood. The long latency in clinical diagnosis (and subsequent adequate treatment) adversely affects the course of disease, effectiveness of interventions and health-related quality of life, and increases the economic burden of BD. Despite uncertainties about risk constellations and symptomatology in the early stages of potentially developing BD, many adolescents and young adults seek help, and most of them suffer substantially from symptoms already leading to impairments in psychosocial functioning in school, training, at work and in their social relationships. We aimed to identify subjects at risk of developing BD and investigate the efficacy and safety of early specific cognitive-behavioural psychotherapy (CBT) in this subpopulation. Methods/Design: EarlyCBT is a randomised controlled multi-centre clinical trial to evaluate the efficacy and safety of early specific CBT, including stress management and problem solving strategies, with elements of mindfulness-based therapy (MBT) versus unstructured group meetings for 14 weeks each and follow-up until week 78. Participants are recruited at seven university hospitals throughout Germany, which provide in- and outpatient care (including early recognition centres) for psychiatric patients. Subjects at high risk must be 15 to 30 years old and meet the combination of specified affective symptomatology, reduction of psychosocial functioning, and family history for (schizo)affective disorders. Primary efficacy endpoints are differences in psychosocial functioning and defined affective symptomatology at 14 weeks between groups. Secondary endpoints include the above mentioned endpoints at 7, 24, 52 and 78 weeks and the change within groups compared to baseline; perception of, reaction to and coping with stress; and conversion to full BD. Discussion: To our knowledge, this is the first study to evaluate early specific CBT in subjects at high risk for BD. Structured diagnostic interviews are used to map the risk status and development of disease. With our study, the level of evidence for the treatment of those young patients will be significantly raised.
45

Depression Does Not Affect the Treatment Outcome of CBT for Panic and Agoraphobia: Results from a Multicenter Randomized Trial

Emmrich, Angela, Beesdo-Baum, Katja, Gloster, Andrew T., Knappe, Susanne, Höfler, Michael, Arolt, Volker, Deckert, Jürgen, Gerlach, Alexander L., Hamm, Alfons, Kircher, Tilo, Lang, Thomas, Richter, Jan, Ströhle, Andreas, Zwanzger, Peter, Wittchen, Hans-Ulrich 13 February 2014 (has links) (PDF)
Background: Controversy surrounds the questions whether co-occurring depression has negative effects on cognitivebehavioral therapy (CBT) outcomes in patients with panic disorder (PD) and agoraphobia (AG) and whether treatment for PD and AG (PD/AG) also reduces depressive symptomatology. Methods: Post-hoc analyses of randomized clinical trial data of 369 outpatients with primary PD/AG (DSM-IV-TR criteria) treated with a 12-session manualized CBT (n = 301) and a waitlist control group (n = 68). Patients with comorbid depression (DSM-IV-TR major depression, dysthymia, or both: 43.2% CBT, 42.7% controls) were compared to patients without depression regarding anxiety and depression outcomes (Clinical Global Impression Scale [CGI], Hamilton Anxiety Rating Scale [HAM-A], number of panic attacks, Mobility Inventory [MI], Panic and Agoraphobia Scale, Beck Depression Inventory) at post-treatment and follow-up (categorical). Further, the role of severity of depressive symptoms on anxiety/depression outcome measures was examined (dimensional). Results: Comorbid depression did not have a significant overall effect on anxiety outcomes at post-treatment and follow-up, except for slightly diminished post-treatment effect sizes for clinician-rated CGI (p = 0.03) and HAM-A (p = 0.008) when adjusting for baseline anxiety severity. In the dimensional model, higher baseline depression scores were associated with lower effect sizes at post-treatment (except for MI), but not at follow-up (except for HAM-A). Depressive symptoms improved irrespective of the presence of depression. Conclusions: Exposure-based CBT for primary PD/AG effectively reduces anxiety and depressive symptoms, irrespective of comorbid depression or depressive symptomatology. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
46

Early specific cognitive-behavioural psychotherapy in subjects at high risk for bipolar disorders: study protocol for a randomised controlled trial

Pfennig, Andrea, Leopold, Karolina, Bechdolf, Andreas, Correll, Christoph U., Holtmann, Martin, Lambert, Martin, Marx, Carolin, Meyer, Thomas D., Pfeiffer, Steffi, Reif, Andreas, Rottmann-Wolf, Maren, Schmitt, Natalie M., Stamm, Thomas, Juckel, Georg, Bauer, Michael 21 July 2014 (has links)
Background: Bipolar disorders (BD) are among the most severe mental disorders with first clinical signs and symptoms frequently appearing in adolescence and early adulthood. The long latency in clinical diagnosis (and subsequent adequate treatment) adversely affects the course of disease, effectiveness of interventions and health-related quality of life, and increases the economic burden of BD. Despite uncertainties about risk constellations and symptomatology in the early stages of potentially developing BD, many adolescents and young adults seek help, and most of them suffer substantially from symptoms already leading to impairments in psychosocial functioning in school, training, at work and in their social relationships. We aimed to identify subjects at risk of developing BD and investigate the efficacy and safety of early specific cognitive-behavioural psychotherapy (CBT) in this subpopulation. Methods/Design: EarlyCBT is a randomised controlled multi-centre clinical trial to evaluate the efficacy and safety of early specific CBT, including stress management and problem solving strategies, with elements of mindfulness-based therapy (MBT) versus unstructured group meetings for 14 weeks each and follow-up until week 78. Participants are recruited at seven university hospitals throughout Germany, which provide in- and outpatient care (including early recognition centres) for psychiatric patients. Subjects at high risk must be 15 to 30 years old and meet the combination of specified affective symptomatology, reduction of psychosocial functioning, and family history for (schizo)affective disorders. Primary efficacy endpoints are differences in psychosocial functioning and defined affective symptomatology at 14 weeks between groups. Secondary endpoints include the above mentioned endpoints at 7, 24, 52 and 78 weeks and the change within groups compared to baseline; perception of, reaction to and coping with stress; and conversion to full BD. Discussion: To our knowledge, this is the first study to evaluate early specific CBT in subjects at high risk for BD. Structured diagnostic interviews are used to map the risk status and development of disease. With our study, the level of evidence for the treatment of those young patients will be significantly raised.
47

Using internet-based self-help to bridge waiting time for face-to-face outpatient treatment for Bulimia Nervosa, Binge Eating Disorder and related disorders: Study protocol of a randomized controlled trial

Vollert, Bianka, Beintner, Ina, Musiat, Peter, Gordon, Gemma, Görlich, Dennis, Nacke, Barbara, Schmidt-Hantke, Juliane, Potterton, Rachel, Spencer, Lucy, Grant, Nina, Schmidt, Ulrike, Jacobi, Corinna 06 December 2018 (has links)
Background: Eating disorders are serious conditions associated with an impaired health-related quality of life and increased healthcare utilization and costs. Despite the existence of evidence-based treatments, access to treatment is often delayed due to insufficient health care resources. Internet-based self-help interventions may have the potential to successfully bridge waiting time for face-to-face outpatient treatment and, thus, contribute to overcoming treatment gaps. However, little is known about the feasibility of implementing such interventions into routine healthcare. The aim of this study is to analyze the effects and feasibility of an Internet-based selfhelp intervention (everyBody Plus) specifically designed for patients with Bulimia Nervosa, Binge Eating Disorder and other specified feeding and eating disorders (OSFED) on a waiting list for outpatient face-to-face treatment. The aim of this paper is to describe the study protocol. Methods: A multi-country randomized controlled trial will be conducted in Germany and the UK. N=275 female patients awaiting outpatient treatment will be randomly allocated either to the guided online self-help intervention “everyBody Plus” or a waitlist control group condition without access to the intervention. everyBody Plus comprises eight weekly sessions that cover topics related to eating and exercise patterns, coping with negative emotions and stress as well as improving body image. Participants will receive weekly individualized feedback based on their self-monitoring and journal entries. Assessments will take place at baseline, post-intervention as well as at 6- and 12-months follow up. In addition, all participants will be asked to monitor core eating disorder symptoms weekly to provide data on the primary outcome. The primary outcome will be number of weeks after randomization until a patient achieves a clinically relevant improvement in core symptoms (BMI, binge eating, compensatory behaviors) for the first time. Secondary outcomes include frequency of core symptoms and eating disorder related attitudes and behaviors, as well as associated psychopathology. Additional secondary outcomes will be the participating therapists' confidence in treating eating disorders as well as perceived benefits of everyBody Plus for patients. Discussion: To the best of our knowledge, this is the first randomized controlled trial examining the effects of Internet-based self-help for outpatients with eating disorders awaiting face-to-face outpatient treatment. If proven to be effective and successfully implemented, Internet-based self-help programs might be used as a first step of treatment within a stepped-care approach, thus reducing burden and cost for both patients and health care providers.
48

Online Self-Help as an Add-On to Inpatient Psychotherapy: Efficacy of a New Blended Treatment Approach

Zwerenz, Rüdiger, Becker, Jan, Knickenberg, Rudolf J., Siepmann, Martin, Hagen, Karin, Beutel, Manfred E. 26 May 2020 (has links)
Background: Depression is one of the most frequent and costly mental disorders. While there is increasing evidence for the efficacy of online self-help to improve depression or prevent relapse, there is little evidence in blended care settings, especially combined with inpatient face-to-face psychotherapy. Therefore, we evaluated whether an evidencebased online self-help program improves the efficacy of inpatient psychotherapy. Methods: A total of 229 depressed patients were randomly allocated either to an online selfhelp program (intervention group [IG]; Deprexis) or an active control group (CG; weekly online information on depression) in addition to inpatient psychodynamic psychotherapy. Both groups had access to their respective experimental intervention for 12 weeks, regardless of inpatient treatment duration. Reduction of depressive symptoms, as measured with the Beck Depression Inventory-II, was the primary outcome at the end of the intervention (T2). Results: Depressive symptoms were statistically significantly lower in the IG compared to the active CG at T2 with a moderate betweengroup effect size of d = 0.44. The same applied to anxiety ( d = 0.33), quality of life ( d = 0.34), and self-esteem ( d = 0.38) at discharge from inpatient treatment (T1). No statistically significant differences were found regarding dysfunctional attitudes ( d = 0.14) and work ability ( d = 0.08) at T1. Conclusions: This is the first evidence for blended treatment combining online self-help with inpatient psychotherapy. The study opens new and promising avenues for increasing the efficacy of inpatient psychotherapy. Future studies should determine how integration of online self-help into the therapeutic process can be developed further.
49

Depression Does Not Affect the Treatment Outcome of CBT for Panic and Agoraphobia: Results from a Multicenter Randomized Trial

Emmrich, Angela, Beesdo-Baum, Katja, Gloster, Andrew T., Knappe, Susanne, Höfler, Michael, Arolt, Volker, Deckert, Jürgen, Gerlach, Alexander L., Hamm, Alfons, Kircher, Tilo, Lang, Thomas, Richter, Jan, Ströhle, Andreas, Zwanzger, Peter, Wittchen, Hans-Ulrich January 2012 (has links)
Background: Controversy surrounds the questions whether co-occurring depression has negative effects on cognitivebehavioral therapy (CBT) outcomes in patients with panic disorder (PD) and agoraphobia (AG) and whether treatment for PD and AG (PD/AG) also reduces depressive symptomatology. Methods: Post-hoc analyses of randomized clinical trial data of 369 outpatients with primary PD/AG (DSM-IV-TR criteria) treated with a 12-session manualized CBT (n = 301) and a waitlist control group (n = 68). Patients with comorbid depression (DSM-IV-TR major depression, dysthymia, or both: 43.2% CBT, 42.7% controls) were compared to patients without depression regarding anxiety and depression outcomes (Clinical Global Impression Scale [CGI], Hamilton Anxiety Rating Scale [HAM-A], number of panic attacks, Mobility Inventory [MI], Panic and Agoraphobia Scale, Beck Depression Inventory) at post-treatment and follow-up (categorical). Further, the role of severity of depressive symptoms on anxiety/depression outcome measures was examined (dimensional). Results: Comorbid depression did not have a significant overall effect on anxiety outcomes at post-treatment and follow-up, except for slightly diminished post-treatment effect sizes for clinician-rated CGI (p = 0.03) and HAM-A (p = 0.008) when adjusting for baseline anxiety severity. In the dimensional model, higher baseline depression scores were associated with lower effect sizes at post-treatment (except for MI), but not at follow-up (except for HAM-A). Depressive symptoms improved irrespective of the presence of depression. Conclusions: Exposure-based CBT for primary PD/AG effectively reduces anxiety and depressive symptoms, irrespective of comorbid depression or depressive symptomatology. / Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
50

Synthesis of α-olefin-based copolymers and nanocomposites

Zakrzewska, Sabina 14 April 2015 (has links)
The research goal of this work was dedicated to improvement of the properties and enhancement of the application potential of commodity polymer based on polyolefins by choosing different synthesis routes to create new structures and materials. More precisely, the presented study explores different aspects of metallocene and post-metallocene catalyzed olefin polymerization leading to synthesis of novel copolymers and nanocomposites. The first part of this thesis deals with controlled polymerization of α-olefins catalyzed by post-metallocenes. Bis(phenoxyamine) zirconium complexes with [ONNO]-type ligands bearing cumyl (bPA-c) and 1-adamantyl (bPA-a) ortho-substituents were applied. For the polymerization catalyzed by bPA catalyst quasi-living kinetic character is proposed. The bPA catalyst was applied for synthesis of block copolymers by employing the strategy of sequential monomer addition. The blocky structure of the copolymer was successfully achieved and confirmed by NMR techniques. Moreover, the monomodal distribution of molar mass in SEC chromatogram confirmed the absence of homopolymers. In the second part of the work new defined comb-like copolymers (CLC) having a poly(10-undecene-1-ol) (PUol) backbone and densely grafted poly(ε-caprolactone) (PCL) side chains are presented. These copolymers were synthesized in two steps by means of metallocene polymerization followed by ring opening polymerization. Copolymers with varied and adjustable graft length (PCL segments) were synthesized. It was proved that the melting and crystallization temperatures of the CLC correlate with the PCL side chain length, i.e. longer chains result in higher Tm and Tc,o values. The melting enthalpy was found to be asymptotically dependent on the length of PCL side chains. The bulk morphology of the comb-like copolymers is proposed to be lamellar as judged from the TEM micrographs. The third part of the thesis is focused on the synthesis of polypropylene nanocomposites via in situ polymerization. Thereby, organomodified aluminumphosphate with kanemite-type layered structure (AlPO-kan) has been used as novel filler. Melt compounding composites were prepared for comparison purposes to evaluate the influence of in situ synthesis on the dispersion quality of the filler in polymer matrix. Melt compounding of neat AlPO-kan with PP did not lead to formation of nanocomposites. TEM images show macro-composites with the lamellar solid remaining agglomerated. On the contrary, in situ polymerization of propene yielded materials with exfoliated nanocomposite morphology. In XRD, diffractions of the AlPO-kan pilling of layers are not detectable. It can be concluded that the primary existing layers are delaminated. Very fine distribution of the filler in the polypropylene matrix has been impressively demonstrated by TEM.

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