Separation Media Based on Defined Hydrogel Systems = Hydrogele als Separationsmedien auf Basis definierter Porengrößen

A variety of potential pathways for the synthesis of defined polymer networks were applied to (meth)acrylic acid based hydrogels and in-depth characterized. The anionic polymerization of a monomer and a bifunctional linker has been employed, as well as the utilization of efficient cross-linking procedures for the ligation of pre-formed telechelic polymers. The ligation techniques included the subsequent addition of a bifunctional monomer and the azide-alkyne Huisgen ligation. Reversible addition-fragmentation transfer polymerization was investigated as a complementary living polymerization procedure. The influence of the topology of the polymer networks on macroscopic properties were examined, such as the absorbency of sodium chloride solutions, the repulsion of salt during the swelling process and the mobility of ions within the network structure. In addition, 1H-NMR relaxometry, double quantum 1H-NMR and inverse size exclusion chromatography were employed to quantify the network architecture

CO2 adsorption performance of pyrolized and activated waste streams

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Efficacy of Varenicline in Patients With Severe Alcohol Dependence: A Pilot Double-Blind Randomized and Controlled Study.

Purpose/Background: Varenicline has proven its efficacy in the treatment of nicotine dependence, and there is also evidence that it could be helpful in the treatment of alcohol dependence. In our pilot study, we investigated the feasibility and acceptability of varenicline for the treatment of a population of patients with severe alcohol dependence and multiple somatic comorbidities after alcohol detoxification. Methods/Procedures: We conducted a phase II, double-blind, placebocontrolled randomized trial of daily oral varenicline versus a placebo in alcohol-dependent men and women after alcohol detoxification (n = 28). Following our study protocol, somatic conditions and adverse events were thoroughly monitored and several study end points were investigated (percentage of abstinent days for both alcohol and nicotine, number of standardized drinks and cigarettes per day, days of heavy drinking). Findings/Results: Compared with the placebo, varenicline did not have more side effects and did not provoke more adverse events. Patients in the varenicline group did not showa significantly higher percentage of alcohol abstinent days or fewer heavy drinking days. A trend significance was found for a reduced number of standard drinks per day (P = 0.06) in the varenicline group. Implications/Conclusions: In this pilot trial, varenicline was shown to be well tolerated by our study population of severely alcohol-dependent patients with somatic conditions. Varenicline did not sustain alcohol abstinence or reduce the number of heavy drinking days, but it did reduce the daily amount of alcohol consumed

Maternal inheritance of twist and analysis of MAPK activation in embryos of the polychaete Annelid Platynereis dumerilii

In this study, we aimed to identify molecular mechanisms involved in the specification of the 4d (mesentoblast) lineage in Platynereis dumerilii. We employ RT-PCR and in situ hybridization against the Platynereis dumerilii twist homolog (Pdu-twist) to reveal mesodermal specification within this lineage. We show that Pdu-twist mRNA is already maternally distributed. After fertilization, ooplasmatic segregation leads to relocation of Pdu-twist transcripts into the somatoblast (2d) lineage and 4d, indicating that the maternal component of Pdu-twist might be an important prerequisite for further mesoderm specification but does not represent a defining characteristic of the mesentoblast. However, after the primordial germ cells have separated from the 4d lineage, zygotic transcription of Pdu-twist is exclusively observed in the myogenic progenitors, suggesting that mesodermal specification occurs after the 4d stage. Previous studies on spiral cleaving embryos revealed a spatio-temporal correlation between the 4d lineage and the activity of an embryonic organizer that is capable to induce the developmental fates of certain micromeres. This has raised the question if specification of the 4d lineage could be connected to the organizer activity. Therefore, we aimed to reveal the existence of such a proposed conserved organizer in Platynereis employing antibody staining against dpERK. In contrast to former observations in other spiralian embryos, activation of MAPK signaling during 2d and 4d formation cannot be detected which questions the existence of a conserved connection between organizer function and specification of the 4d lineage. However, our experiments unveil robust MAPK activation in the prospective nephroblasts as well as in the macromeres and some micromeres at the blastopore in gastrulating embryos. Inhibition of MAPK activation leads to larvae with a shortened body axis, defects in trunk muscle spreading and improper nervous system condensation, indicating a critical function for MAPK signaling for the reorganization of embryonic tissues during the gastrulation process

Restricted duty hours for surgeons and impact on residents quality of life, education, and patient care: a literature review

<p>Abstract</p> <p>Background</p> <p>Work-hour limitations have been implemented by the Accreditation Council for Graduate Medical Education (ACGME) in July 2003 in order to minimize fatigue related medical adverse events. The effects of this regulation are still under intense debate. In this literature review, data of effects of limited work-hours on the quality of life, surgical education, and patient care was summarized, focusing on surgical subspecialities.</p> <p>Methods</p> <p>Studies that assessed the effects of the work-hour regulation published following the implementation of ACGME guidelines (2003) were searched using PubMed database. The following search modules were selected: work-hours, 80-hour work week, quality of life, work satisfaction, surgical education, residency training, patient care, continuity of care. Publications were included if they were completed in the United States and covered the subject of our review. Manuscrips were analysed to identify authors, year of publication, type of study, number of participants, and the main outcomes.</p> <p>Review Findings</p> <p>Twenty-one articles met the inclusion criteria. Studies demonstrate that the residents quality of life has improved. The effects on surgical education are still unclear due to inconsistency in studies. Furthermore, according to several objective studies there were no changes in mortality and morbidity following the implementation.</p> <p>Conclusion</p> <p>Further studies are necessary addressing the effects of surgical education and studying the objective methods to assess the technical skill and procedural competence of surgeons. In addition, patient surveys analysing their satisfaction and concerns can contribute to recent discussion, as well.</p

Full- & Reduced-Order State-Space Modeling of Wind Turbine Systems with Permanent-Magnet Synchronous Generator

Wind energy is an integral part of nowadays energy supply and one of the fastest growing sources of electricity in the world today. Accurate models for wind energy conversion systems (WECSs) are of key interest for the analysis and control design of present and future energy systems. Existing control-oriented WECSs models are subject to unstructured simplifications, which have not been discussed in literature so far. Thus, this technical note presents are thorough derivation of a physical state-space model for permanent magnet synchronous generator WECSs. The physical model considers all dynamic effects that significantly influence the system's power output, including the switching of the power electronics. Alternatively, the model is formulated in the $(a,b,c)$- and $(d,q)$-reference frame. Secondly, a complete control and operation management system for the wind regimes II and III and the transition between the regimes is presented. The control takes practical effects such as input saturation and integral windup into account. Thirdly, by a structured model reduction procedure, two state-space models of WECS with reduced complexity are derived: a non-switching model and a non-switching reduced-order model. The validity of the models is illustrated and compared through a numerical simulation study.Comment: 23 pages, 11 figure

Synergetic Utilization of Renewable and Fossil Fuels: Dual Fluidized Bed Steam Co-gasification of Coal and Wood

AbstractGasification of biomass and coal is an attractive technology for combined heat and power production, as well as for synthesis processes such as the production of liquid and gaseous biofuels. The allothermal steam blown gasification process yields a high calorific product gas, practically free of nitrogen. Originally designed for wood chips, the system can also handle a large number of alternative fuels. To demonstrate the influence on the system performance of fuels that have a different origin, wood pellets, as the designated feedstock, and hard coal as an example fossil fuel were fed into the DFB gasifier with a fuel blend ratio of 20% coal in terms of energy. A fuel power of 78kW and a steam to fuel ratio of 1.0kg/kgdb were achieved. The system was operated at gasification temperatures between 830 and 870°C. This paper points out the influence of the temperature on the system

Fluid-Dynamic Investigations in a Cold Model for a Dual Fluidized Bed Biomass Steam Gasification Process: Optimization of the Cyclone

Gasification of biomass is an attractive technology for combined heat and power production. Although a great deal of research and development work has been carried out during the past decade the commercial breakthrough for this technology is still not in sight. The optimisation of the operation costs influences significantly the economic efficiency. Especially bed material consumption constitutes a major part of expenses in fluidised bed systems. Thus, cyclones for circulating fluidized beds need to be designed properly. A dual fluidized bed steam gasifier is in commercial operation at the biomass CHP (combined heat and power plant) in Güssing, Austria since 2002. Some erosion and caking in the cyclone of the CHP plant could be observed with increasing hours of operation. The influences of these effects as well as the influence of the solid circulation rate between the two units on the separation efficiency were investigated by fluid-dynamic investigations using a cold model. The results show that due to erosion and caking elutriation rates are increased, especially for smaller particles. However, the cyclone achieves fractional separation efficiencies of more than 99.9%