93 research outputs found
Energieeffizienz bei der industriellen Drucklufterzeugung - Studie zu Entwicklungen, Trends und alternativen Erzeugungstechnologien
Betrachtet man die Entwicklung des weltweiten PrimĂ€renergiebedarfs mit Blick auf dessen prognostizierte jĂ€hrliche Steigerung, so offenbart sich unter BerĂŒcksichtigung der weltweiten Ressourcenverknappung und âverfĂŒgbarkeit die Notwendigkeit der Suche nach neuen Möglichkeiten und Methoden, um soziale, ökologische und ökonomische Nachhaltigkeit unter diesen sich Ă€ndernden Rahmenbedingungen zu gewĂ€hrleisten. ZusĂ€tzlich zur Ressourcenproblematik ist die umweltpolitische Dimension des Klimawandels und somit die Forderung zur Senkung des klimarelevanten Gases CO2, welches hauptsĂ€chlich bei der Verbrennung fossiler
EnergietrĂ€ger anfĂ€llt, anzufĂŒhren. Als vielversprechendste Möglichkeit zur Senkung des fossilen PrimĂ€renergiebedarfs und zur Reduzierung von Treibhausgasen gilt neben der Substitution fossiler EnergietrĂ€ger durch Erneuerbare Energien die Steigerung der Energieeffizienz. Eine in der industriellen Anwendung weit verbreitete Querschnittstechnologie, die in vielen Anwendungsfeldern wie z. B. der Automatisierungstechnik, der GeblĂ€seâ und BelĂŒftungstechnik sowie bei vielen weiteren industriellen Prozessen eingesetzt wird, ist die Drucklufttechnologie. Dieser Artikel beschreibt die Ergebnisse einer Studie bezĂŒglich Entwicklungen, aktuellen Trends und alternativen Methoden zur energieeffizienten Erzeugung industrieller Druckluft
Synthesis of the HIV-Proteinase Inhibitor Saquinavir: A Challenge for Process Research
The task of process research, namely developing efficient, economically and technically as well as ecologically feasible syntheses in time, is demonstrated on the HIV-proteinase inhibitor Saquinavir, a complex molecule comprising six stereo-centres. Based on the first 26-step research
synthesis furnishing a 10% overall yield, process research established a new, short 11-step synthesis affording a 50% overall yield
Prospective, open, multi-centre phase I/II trial to assess safety and efficacy of neoadjuvant radiochemotherapy with docetaxel and oxaliplatin in patients with adenocarcinoma of the oesophagogastric junction
Background: This phase I/II-trial assessed the dose-limiting toxicities (DLT) and maximum tolerated dose (MTD) of neoadjuvant radiochemotherapy (RCT) with docetaxel and oxaliplatin in patients with locally advanced adenocarcinoma of the oesophagogastric junction.
Methods: Patients received neoadjuvant radiotherapy (50.4âGy) together with weekly docetaxel (20âmg/m2 at dose level (DL) 1 and 2, 25âmg/m2 at DL 3) and oxaliplatin (40âmg/m2 at DL 1, 50âmg/m2 at DL 2 and 3) over 5âweeks. The primary endpoint was the DLT and the MTD of the RCT regimen. Secondary endpoints included overall response rate (ORR) and progression-free survival (PFS).
Results: A total of 24 patients were included. Four patients were treated at DL 1, 13 patients at DL 2 and 7 patients at DL 3. The MTD of the RCT was considered DL 2 with docetaxel 20âmg/m2 and oxaliplatin 50âmg/m2. Objective response (CR/PR) was observed in 32% (7/22) of patients. Eighteen patients (75%) underwent surgery after RCT. The median PFS for all patients (nâ=â24) was 6.5âmonths. The median overall survival for all patients (nâ=â24) was 16.3âmonths. Patients treated at DL 2 had a median overall survival of 29.5âmonths.
Conclusion: Neoadjuvant RCT with docetaxel 20âmg/m2 and oxaliplatin 50âmg/m2 was effective and showed a good toxicity profile. Future studies should consider the addition of targeted therapies to current neoadjuvant therapy regimens to further improve the outcome of patients with advanced cancer of the oesophagogastric junction.
Trial Registration: NCT0037498
A prospective, blinded evaluation of a video-assisted â4-stage approachâ during undergraduate student practical skills training
BACKGROUND: The 4-stage approach (4-SA) is used as a didactic method for teaching practical skills in international courses on resuscitation and the structured care of trauma patients. The aim of this study was to evaluate objective and subjective learning success of a video-assisted 4-SA in teaching undergraduate medical students. METHODS: The participants were medical students learning the principles of the acute treatment of trauma patients in their multidiscipline course on emergency and intensive care medicine. The participants were quasi- randomly divided into two groups. The 4-SA was used in both groups. In the control group, all four steps were presented by an instructor. In the study group, the first two steps were presented as a video. At the end of the course a 5-minute objective, structured clinical examination (OSCE) of a simulated trauma patient was conducted. The test results were divided into objective results obtained through a checklist with 9 dichotomous items and the assessment of the global performance rated subjectively by the examiner on a Likert scale from 1 to 6. RESULTS: 313 students were recruited; the results of 256 were suitable for analysis. The OSCE results were excellent in both groups and did not differ significantly (control group: median 9, interquantil range (IQR) 8â9, study group: median 9, IQR 8â9; pâ=â0.29). The global performance was rated significantly better for the study group (median 1, IQR 1â2 vs. median 2, IQR 1â3; pâ<â0.01). The relative knowledge increase, stated by the students in their evaluation after the course, was greater in the study group (85% vs. 80%). CONCLUSION: It is possible to employ video assistance in the classical 4-SA with comparable objective test results in an OSCE. The global performance was significantly improved with use of video assistance
Use of the GlideScopeÂź-Ranger for pre-hospital intubations by anaesthesia trained emergency physicians â an observational study
Background: Pre-hospital endotracheal intubation is more difficult than in the operating room (OR). Therefore, enhanced airway management devices such as video laryngoscopes may be helpful to improve the success rate of pre-hospital intubation. We describe the use of the GlidescopeÂź-Ranger (GS-R) as an alternative airway tool used at the discretion of the emergency physician (EP) in charge. Methods: During a 3.5 year period, the GS-R was available to be used either as the primary or backup tool for pre-hospital intubation by anaesthesia trained EP with limited expertise using angulated videolaryngoscopes. Results: During this period 672 patients needed pre-hospital intubation of which the GS-R was used in 56 cases. The overall GS-R success rate was 66 % (range of 34â100 % among EP). The reasons for difficulties or failure included inexperience of the EP with the GS-R, impaired view due to secretion, vomitus, blood or the inability to see the screen in very bright environment due to sunlight. Conclusion: Special expertise and substantial training is needed to successfully accomplish tracheal intubation with the GS-R in the pre-hospital setting. Providers inexperienced with DL as well as video-assisted intubation should not expect to be able to perform tracheal intubation easily just because a videolaryngoscope is available. Additionally, indirect laryngoscopy might be difficult or even impossible to achieve in the pre-hospital setting due to impeding circumstances such as blood, secretions or bright sun-light. Therefore, videolaryngoscopes, here the GS-R, should not be considered as the âHoly Grailâ of endotracheal intubation, neither for the experts nor for inexperienced providers. Electronic supplementary material The online version of this article (doi:10.1186/s12873-016-0069-2) contains supplementary material, which is available to authorized users
Impact of the Gut Microbiota on Atorvastatin Mediated Effects on Blood Lipids
Background and aims:
The mechanisms of interindividual variation of lipid regulation by statins, such as the low-density lipoprotein cholesterol (LDL) lowering effects, are not fully understood yet. Here, we used a gut microbiota depleted mouse model to investigate the relation between the gut microbiota and the regulatory property of atorvastatin on blood lipids.
Methods:
Mice (C57BL/6) with intact gut microbiota or antibiotic induced abiotic mice (ABS) were put on standard chow diet (SCD) or high fat diet (HFD) for six weeks. Atorvastatin (10 mg/kg body weight/day) or a control vehicle were applied per gavage for the last four weeks of dietary treatment. Blood lipids including total cholesterol, very low-density lipoprotein, low-density lipoprotein, high-density lipoprotein and sphingolipids were measured to probe microbiota-dependent effects of atorvastatin. The expression of genes involved in hepatic and intestinal cholesterol metabolism was analyzed with qRT-PCR. The alteration of the microbiota profile was examined using 16S rRNA qPCR in mice with intact gut microbiota.
Results:
HFD feeding significantly increased total blood cholesterol and LDL levels, as compared to SCD in both mice with intact and depleted gut microbiota. The cholesterol lowering effect of atorvastatin was significantly attenuated in mice with depleted gut microbiota. Moreover, we observed a global shift in the abundance of several sphingolipids upon atorvastatin treatment which was absent in gut microbiota depleted mice. The regulatory effect of atorvastatin on the expression of distinct hepatic and intestinal cholesterol-regulating genes, including Ldlr, Srebp2 and Npc1l1 was altered upon depletion of gut microbiota. In response to HFD feeding, the relative abundance of the bacterial phyla Bacteroidetes decreased, while the abundance of Firmicutes increased. The altered ratio between Firmicutes to Bacteroidetes was partly reversed in HFD fed mice treated with atorvastatin.
Conclusions:
Our findings support a regulatory impact of atorvastatin on the gut microbial profile and, in turn, demonstrate a crucial role of the gut microbiome for atorvastatin-related effects on blood lipids. These results provide novel insights into potential microbiota-dependent mechanisms of lipid regulation by statins, which may account for variable response to statin treatment
Use of cell-free collagen type I matrix implants for the treatment of small cartilage defects in the knee: clinical and magnetic resonance imaging evaluation
Abstract Purpose Articular cartilage defects of the knee are a common condition for which several repair techniques have been described. The aim of the present study was to assess medium-term results of a one-step procedure using a cell-free collagen type I matrix. Methods Fifteen patients with articular cartilage defects of the knee were treated with an 11-mm-diameter cell-free collagen type 1 matrix implant. The matrices were implanted in a press-fit manner into the defect after careful debridement down to the subchondral bone but without penetration of this margin. Follow-up examinations were carried out at 6 weeks, 6 months, and at 12, 24, 36, and 48 months after implantation. Clinical assessment included the visual analogue scale (VAS), the Tegner activity scale, and the International Knee Documentation Committee (IKDC) score. Radiological assessment for graft attachment and tissue regeneration was performed using the magnetic observation of cartilage repair tissue (MOCART) score. Results A total of 15 patients (males: n = 6 and females: n = 9) with a mean age of 26.4 years (range 19-40) were treated. The mean VAS improved significantly when compared to the preoperative values (P \ 0.05). Six weeks after implantation, IKDC values were slightly lower than the preoperative values (n.s.), but increased significantly at final follow-up (P \ 0.05). At 24 months, there were no significant differences in the median Tegner score between the post-operative values and the preoperative values (n.s.). However, after 36 months, a significant improvement was noted that lasted at least up to 48 months (P \ 0.05). The MOCART score improved consistently up to 4 years after implantation, with significant improvements already observed after 12 months (P \ 0.05). No correlation between the clinical scores and the MOCART score could be perceived. Conclusion The present study showed that the use of cellfree collagen type I matrix implants led to a significant and durable improvement in all the clinical and imaging scores investigated 4 years after implantation. Level of evidence IV
Highly Selective PTK2 Proteolysis Targeting Chimeras to Probe Focal Adhesion Kinase Scaffolding Functions
Focal adhesion tyrosine
kinase (PTK2) is often overexpressed in human hepatocellular carcinoma
(HCC), and several reports have linked PTK2 depletion and/or pharmacological
inhibition to reduced tumorigenicity. However, the clinical relevance
of targeting PTK2 still remains to be proven. Here, we present two
highly selective and functional PTK2 proteolysis-targeting chimeras
utilizing von HippelâLindau and cereblon ligands to hijack
E3 ligases for PTK2 degradation. BI-3663 (cereblon-based) degrades
PTK2 with a median DC<sub>50</sub> of 30 nM to >80% across a panel
of 11 HCC cell lines. Despite effective PTK2 degradation, these compounds
did not phenocopy the reported antiproliferative effects of PTK2 depletion
in any of the cell lines tested. By disclosing these compounds, we
hope to provide valuable tools for the study of PTK2 degradation across
different biological systems
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Selective Sirt2 inhibition by ligand-induced rearrangement of the active site
Sirtuins are a highly conserved class of NAD+-dependent lysine deacylases. The human isotype Sirt2 has been implicated in the pathogenesis of cancer, inflammation and neurodegeneration, which makes the modulation of Sirt2 activity a promising strategy for pharmaceutical intervention. A rational basis for the development of optimized Sirt2 inhibitors is lacking so far. Here we present high-resolution structures of human Sirt2 in complex with highly selective drug-like inhibitors that show a unique inhibitory mechanism. Potency and the unprecedented Sirt2 selectivity are based on a ligand-induced structural rearrangement of the active site unveiling a yet-unexploited binding pocket. Application of the most potent Sirtuin-rearranging ligand, termed SirReal2, leads to tubulin hyperacetylation in HeLa cells and induces destabilization of the checkpoint protein BubR1, consistent with Sirt2 inhibition in vivo. Our structural insights into this unique mechanism of selective sirtuin inhibition provide the basis for further inhibitor development and selective tools for sirtuin biology
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