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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.
121

Zinc(II) Adsorption by Low-Carbon Shungite: The Effect of pH

Fischer, Axel R., Sgolik, Luisa, Kreller, André, Dornack, Christina 11 June 2018 (has links)
Shungite is a carbonaceous rock which is abundant in Karelia (Russian Federation). Large deposits of shungite with low levels of carbon (approx. 10% C) are also found in Kazakhstan, where it is mined under the trade name Taurit (Koksu Mining Company). Although Taurit has been reported to be used as an adsorbent for hazardous compounds in water treatment, there is very little precise data about its adsorption capacity or the compounds adsorbed. In this study, the ability of Taurit to adsorb Zn(II) was investigated and Freundlich isotherms were determined for both distilled water and tap water. Taurit was found to have a high buffer capacity leading to pH values > 7.0 in aqueous solution. Because dissolved zinc precipitates as Zn(OH)2 under alkaline conditions, the pH must be carefully controlled and kept ≤7.0. Despite the small inner surface area (BET) of Taurit (13.4 m2 g−1), Freundlich coefficients for distilled water (Kf = 2.4, n = 4.0) and tap water (Kf = 1.5, n = 2.5) were similar to other adsorbents. Our results indicate that Taurit could provide a cheap alternative to activated carbon since both substances have a similar adsorption capacity (at least for Zn(II)).
122

Impact of telephone prompts on the adherence to an Internet-based aftercare program for women with bulimia nervosa: A secondary analysis of data from a randomized controlled trial

Beintner, Ina, Jacobi, Corinna 07 June 2018 (has links)
Introduction Poor adherence is a common challenge in self-directed mental health interventions. Research findings indicate that telephone prompts may be useful to increase adherence. Method Due to poor adherence in a randomized controlled trial evaluating an Internet-based aftercare program for women with bulimia nervosa we implemented regular short telephone prompts into the study protocol halfway through the trial period. Of the 126 women in the intervention group, the first 63 women were not prompted by telephone (unprompted group) and compared with 63 women who subsequently enrolled into the study and were attempted to prompt bimonthly by a research assistant (telephone prompt group). Completed telephone calls took less than 5 min and did not include any symptom-related counseling. Results Most of the women in the telephone prompt group (67%) were reached only once or twice during the intervention period. However, overall adherence in the telephone prompt group was significantly higher than in the unprompted group (T = − 3.015, df = 124, p = 0.003). Conclusion Our findings from this secondary analysis suggest that telephone prompts can positively affect adherence to an Internet-based aftercare intervention directed at patients with bulimia nervosa.
123

Effect of Chemical Disinfection on Chitosan Coated PMMA and PETG Surfaces—An In Vitro Study

Walczak, Katarzyna, Thiele, Jessica, Geisler, Daniel, Boening, Klaus, Wieckiewicz, Mieszko 12 June 2018 (has links)
In oral sciences, chitosan application is of interest due to its antimicrobial and hemostatic activity. Chitosan coating of dentures and other intraoral devices could be beneficial for treatment of denture stomatitis or in the management of postoperative bleeding. Disinfection of dentures and prosthodontic materials is crucial before their use in patients. This study investigated the influence of chemical disinfectants on chitosan-coated surfaces. A total of 100 specimens were made: 50 of PMMA (polymethyl methacrylate), and 50 of PETG (polyethylene terephthalate glycol-modified) material and coated with 2% chitosan acetate solution. In each material, 5 groups (10 specimens each) were established and disinfected with Printosept-ID (L1), MD 520 (L2), Silosept (L3), or Dentavon (L4), or stored in distilled water (L0, control group). After disinfection, all specimens underwent abrasion tests (30,000 cycles in a tooth-brushing simulator). Areas without chitosan coating were measured by digital planimetry both before and after the disinfection/abrasion procedure and a damage-score was calculated. Regarding chitosan coating, the statistical analysis showed a significant influence of the disinfectants tested and significant differences between disinfectants (p < 0.05). Chitosan coating was most stable on PMMA and PETG after disinfection with MD 520 (L2). Otherwise, active oxygen containing disinfectants (L3, L4) led to the greatest alterations in the chitosan coating.
124

A nonuniform popularity-similarity optimization (nPSO) model to efficiently generate realistic complex networks with communities

Muscoloni, Alessandro, Cannistraci, Carlo Vittorio 12 June 2018 (has links)
The investigation of the hidden metric space behind complex network topologies is a fervid topic in current network science and the hyperbolic space is one of the most studied, because it seems associated to the structural organization of many real complex systems. The popularity-similarity-optimization (PSO) model simulates how random geometric graphs grow in the hyperbolic space, generating realistic networks with clustering, small-worldness, scale-freeness and rich-clubness. However, it misses to reproduce an important feature of real complex networks, which is the community organization. The geometrical-preferential-attachment (GPA) model was recently developed in order to confer to the PSO also a soft community structure, which is obtained by forcing different angular regions of the hyperbolic disk to have a variable level of attractiveness. However, the number and size of the communities cannot be explicitly controlled in the GPA, which is a clear limitation for real applications. Here, we introduce the nonuniform PSO (nPSO) model. Differently from GPA, the nPSO generates synthetic networks in the hyperbolic space where heterogeneous angular node attractiveness is forced by sampling the angular coordinates from a tailored nonuniform probability distribution (for instance a mixture of Gaussians). The nPSO differs from GPA in other three aspects: it allows one to explicitly fix the number and size of communities; it allows one to tune their mixing property by means of the network temperature; it is efficient to generate networks with high clustering. Several tests on the detectability of the community structure in nPSO synthetic networks and wide investigations on their structural properties confirm that the nPSO is a valid and efficient model to generate realistic complex networks with communities.
125

Long-term impacts of prenatal synthetic glucocorticoids exposure on functional brain correlates of cognitive monitoring in adolescence

Ilg, Liesa, Klados, Manousos, Alexander, Nina, Kirschbaum, Clemens, Li, Shu-Chen 12 June 2018 (has links)
The fetus is highly responsive to the level of glucocorticoids in the gestational environment. Perturbing glucocorticoids during fetal development could yield long-term consequences. Extending prior research about effects of prenatally exposed synthetic glucocorticoids (sGC) on brain structural development during childhood, we investigated functional brain correlates of cognitive conflict monitoring in term-born adolescents, who were prenatally exposed to sGC. Relative to the comparison group, behavioral response consistency (indexed by lower reaction time variability) and a brain correlate of conflict monitoring (the N2 event-related potential) were reduced in the sGC exposed group. Relatedly, source localization analyses showed that activations in the fronto-parietal network, most notably in the cingulate cortex and precuneus, were also attenuated in these adolescents. These regions are known to subserve conflict detection and response inhibition as well as top-down regulation of stress responses. Moreover, source activation in the anterior cingulate cortex correlated negatively with reaction time variability, whereas activation in the precuneus correlated positively with salivary cortisol reactivity to social stress in the sGC exposed group. Taken together, findings of this study indicate that prenatal exposure to sGC yields lasting impacts on the development of fronto-parietal brain functions during adolescence, affecting multiple facets of adaptive cognitive and behavioral control.
126

Cytotoxicity of drugs injected into joints in orthopaedics

Busse, Patricia, Vater, Corina, Stiehler, Maik, Nowotny, Jörg, Kasten, Philip, Bretschneider, Henriette, Goodman, Stuart B., Gelinsky, Michael, Zwingenberger, Stefan 26 April 2019 (has links)
Objectives Intra-articular injections of local anaesthetics (LA), glucocorticoids (GC), or hyaluronic acid (HA) are used to treat osteoarthritis (OA). Contrast agents (CA) are needed to prove successful intra-articular injection or aspiration, or to visualize articular structures dynamically during fluoroscopy. Tranexamic acid (TA) is used to control haemostasis and prevent excessive intra-articular bleeding. Despite their common usage, little is known about the cytotoxicity of common drugs injected into joints. Thus, the aim of our study was to investigate the effects of LA, GC, HA, CA, and TA on the viability of primary human chondrocytes and tenocytes in vitro. Methods Human chondrocytes and tenocytes were cultured in a medium with three different drug dilutions (1:2; 1:10; 1:100). The following drugs were used to investigate cytotoxicity: lidocaine hydrochloride 1%; bupivacaine 0.5%; triamcinolone acetonide; dexamethasone 21-palmitate; TA; iodine contrast media; HA; and distilled water. Normal saline served as a control. After an incubation period of 24 hours, cell numbers and morphology were assessed. Results Using LA or GC, especially triamcinolone acetonide, a dilution of 1:100 resulted in only a moderate reduction of viability, while a dilution of 1:10 showed significantly fewer cell counts. TA and CA reduced viability significantly at a dilution of 1:2. Higher dilutions did not affect viability. Notably, HA showed no effects of cytotoxicity in all drug dilutions. Conclusion The toxicity of common intra-articular injectable drugs, assessed by cell viability, is mainly dependent on the dilution of the drug being tested. LA are particularly toxic, whereas HA did not affect cell viability.
127

Internet-based aftercare for women with bulimia nervosa following inpatient treatment: The role of adherence

Beintner, Ina, Jacobi, Corinna 26 April 2019 (has links)
Facing poor long-term outcome and high relapse rates in the treatment of bulimia nervosa, we developed an Internet-based aftercare program for women with severe and chronic bulimia nervosa following inpatient treatment based on previous experiences with self-directed targeted prevention and early intervention programs delivered online. The aim of the present study was to examine adherence to the program in detail, to explore potential variables that predict adherence and to analyze whether adherence affects outcomes. We analyzed data from 126 women in the intervention group of a randomized controlled trial. 107 women (85%) logged on to the program platform at least once. These women opened on average 42.8% (SD=31.9%) of all assigned program pages. Adherence declined during the course of the intervention. Adherence was not associated with the number of outpatient treatment sessions received during the intervention period. Adherence was not related to overall illness severity or duration at baseline. However, excessive exercise at hospital discharge (which may be a sign of insufficient motivation to change eating disorder related behaviors) seems to play some small role in adherence. Adherence did not affect intervention outcomes. Based on our findings, we would like to advocate further research on online aftercare interventions for women with severe and chronic bulimia nervosa.
128

Influence of the Kinaesthetics care conception during patient handling on the development of musculoskeletal complaints and diseases - A scoping review

Freiberg, Alice, Girbig, Maria, Euler, Ulrike, Scharfe, Julia, Nienhaus, Albert, Freitag, Sonja, Seidler, Andreas 06 February 2017 (has links)
The Kinaesthetics care conception is a nursing approach for patient handling which aims to prevent work-related complaints and diseases. The evidence about the influence of Kinaesthetics on musculoskeletal disorders among persons who handle patients is unclear to date. The purposes of the scoping review are to gain insight into the current state of research regarding the clinical effectiveness of Kinaesthetics (in terms of perceived exertion and musculoskeletal complaints) among persons who handle patients and to identify potential research gaps. A scoping review was conducted. The search strategy comprised a systematic search in electronic databases (MEDLINE, EMBASE, AMED, CINAHL), a hand search, a fast forward search (Web of Science) and a Google scholar-search. The review process was carried out independently by two reviewers. Methodological quality was assessed for all studies using three methodological main categories (reporting quality, internal validity, external validity). Thirteen studies with different study designs were included. Seven studies investigated musculoskeletal complaints and nine studies the perceived exertion of nursing staff. Most studies were of very low methodology. Most studies reported a decrease of musculoskeletal complaints and perceived exertion due to Kinaesthetics. In conclusion, there is only little evidence of very low quality about the effectiveness of Kinaesthetics. Out of the studies it could be assumed that Kinaesthetics may decrease the patient handling related perceived exertion and musculoskeletal pain of persons who handle patients. But an overestimation of these results is likely, due to inadequate methodology of included studies. As a result, no clear recommendations about the effectiveness of the Kinaesthetics care conception can be made yet. Since a research gap was shown, further high quality intervention studies are necessary for clarifying the effectiveness of Kinaesthetics.
129

Identification and analysis of Eimeria nieschulzi gametocyte genes reveal splicing events of gam genes and conserved motifs in the wall-forming proteins within the genus Eimeria (Coccidia, Apicomplexa)

Wiedmer, Stefanie, Erdbeer, Alexander, Volke, Beate, Randel, Stephanie, Kapplusch, Franz, Hanig, Sacha, Kurth, Michael 04 June 2018 (has links)
The genus Eimeria (Apicomplexa, Coccidia) provides a wide range of different species with different hosts to study common and variable features within the genus and its species. A common characteristic of all known Eimeria species is the oocyst, the infectious stage where its life cycle starts and ends. In our study, we utilized Eimeria nieschulzi as a model organism. This rat-specific parasite has complex oocyst morphology and can be transfected and even cultivated in vitro up to the oocyst stage. We wanted to elucidate how the known oocyst wall-forming proteins are preserved in this rodent Eimeria species compared to other Eimeria. In newly obtained genomics data, we were able to identify different gametocyte genes that are orthologous to already known gam genes involved in the oocyst wall formation of avian Eimeria species. These genes appeared putatively as single exon genes, but cDNA analysis showed alternative splicing events in the transcripts. The analysis of the translated sequence revealed different conserved motifs but also dissimilar regions in GAM proteins, as well as polymorphic regions. The occurrence of an underrepresented gam56 gene version suggests the existence of a second distinct E. nieschulzi genotype within the E. nieschulzi Landers isolate that we maintain.
130

Syntheses of Acyclic and Macrocyclic Compounds Derived from 9,9‐Diethylfluorene (Part I)

Seidel, Pierre, Mazik, Monika 20 October 2021 (has links)
A series of new 9,9‐diethylfluorenes consisting of three side‐arms each bearing a heterocyclic, bis(carboxymethyl)amino, bis(carbamoylmethyl)amino, bis(ethoxycarbonylmethyl)amino or an amino group were prepared on the basis of 2,4,7‐tris(bromomethyl)‐9,9‐diethylfluorene. Imidazolyl, benzimidazolyl, pyrazolyl, pyrrolyl, 1,3‐dioxoisoindolyl and pyridinium groups were taken into account as heterocyclic units, attached to the aromatic skeleton via −CH2−, −CH2NHCH2− or −CH2N=CH− linkers. In addition to the seventeen 2,4,7‐trisubstituted 9,9‐diethylfluorenes, two macrocyclic compounds were prepared on the basis of 2,7‐bis(aminomethyl)‐9,9‐diethylfluorene. The excellent yield of the macrocyclization reaction is worth a special mention. Both the acyclic and the macrocyclic fluorene‐based compounds have, among other things, the potential to act as artificial receptors for different substrates in analogy to the known receptors consisting of a benzene or biphenyl core.

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