Wirkortäquilibration, Anschlagzeit, "time to peak effect": Bedeutung pharmakokinetisch-dynamischer Prinzipien für die tägliche klinische Praxis

Zusammenfassung: In der anästhesiologischen Pharmakologie spielen im Gegensatz zur internistischen Pharmakologie "Non-steady-state-Phänomene" eine herausragende Rolle. Ihr Verständnis ist eine Conditio sine qua non für die sichere und effiziente Applikation von anästhesierelevanten Medikamenten. Insbesondere die Verfügbarkeit der "optimierten target controlled infusion" ("optimized TCI"), von TCI-Systemen mit Ansteuerung des Effektkompartiments und dem relativ geringen Dosierungsspielraum bei "conscious sedation" unter erhaltener Spontanatmung verlangen von Anästhesisten, sich mit dem Konzept des Konzentrationsverlaufes am Wirkort auseinander zu setzen. Der Leser wird in die grundlegende Problematik eingeführt. Anwendungen der Prinzipien bei der Applikation von Muskelrelaxanzien, Propofol mit TCI-Systemen, volatilen Anästhetika und Opiaten werden erläuter

Postmortem Dental Records Identification by Dental Hygiene Students: A Pilot Study

Purpose: Dental hygienists have the potential for filling critical roles in multidisciplinary victim identification teams. The purpose of this pilot study was to evaluate the accuracy of dental hygiene students utilizing dental charting, bitewings, and skull dentitions for the purpose of making identification matches. Methods: Thirty senior dental hygiene students (n=30) independently viewed an asynchronous online multimedia-based presentation on the procedures used for collecting and recording forensic dental evidence. Following the presentation participants attempted to chart and match three bitewing radiograph sets to three human skull dentitions by correlating matches/exclusions. Immediately following the activity, each student completed a questionnaire rating the difficulty of the exercise, as well as their confidence, and willingness to volunteer as a forensics team member. Descriptive statistics were used to analyze the data. Results: Of the total sample 36.7% (n=11) reported having prior experiences with dental radiography; while the majority (63.33%, n=19) reported no prior experience. Participants\u27 accuracy scores for dental charting ranged from 91.23% (SD=9.42) to 99.06% (SD=3.60), with no statistically significant difference based on prior experience (p\u3e0.05). The average interrater reliability was 86% (p\u3c0.0001), indicating a high level of agreement with charting skulls and radiographs. No statistically significant differences were found for charting time, perceived difficulty, or level of confidence when comparing experience among the participants (p\u3e0.05). Conclusions: Regardless of previous experience, dental hygiene students were able to match postmortem dentitions and radiographs with good interrater reliability and did not differ statistically for charting time, perceived difficulty, or confidence. Results suggest dental hygienists can work as effective victim identification team members when educational programs are implemented

Disaster Preparedness and Response: A Survey of U.S. Dental Hygienists

Purpose: The purpose of this study was to assess dental hygienists’ interests, current involvement, formal education, views, comfort levels, and intentions for involvement with disaster preparedness and response. Methods: Dental hygienists (n=400) were asked to respond to a 21-item online survey. Data was analyzed using descriptive statistics, chi-square goodness-of-fit tests, and a paired-samples t-test. Common themes were identified and categorized from open-ended questions. Results: A response rate of 84% (n=334) was obtained. Most respondents (97%) reported no involvement with disaster preparedness and response; however, a majority (86%) reported interest. Of those who indicated an interest in disaster preparedness and response, 92% had intentions for becoming involved. A majority of dental hygienists (93%) had not received formal education in disaster preparedness and response; yet, 95% shared the view that dental hygienists could have a vital role in this specialty area. Although results indicated a mean difference of 9% increased comfort with activities not requiring physical contact with human remains, dental hygienists were relatively comfortable with activities requiring contact: taking photographs (76%, n=254), taking radiographs (83%, n=273), resecting the mandible (55%, n=184), cleaning skeletonized remains (67%, n=221). Conclusion: Dental hygienists view themselves as professionals who could have a vital role in disaster preparedness and response. Efforts should be made to increase dental hygiene formal education in disaster preparedness and response with needed curriculum models and competencies for best outcomes when dental hygienists are serving their communities

The impact of reduction of doublet well spacing on the Net Present Value and the life time of fluvial Hot Sedimentary Aquifer doublets

This paper evaluates the impact of reduction of doublet well spacing, below the current West Netherlands Basin standard of 1000 to 1500 m, on the Net Present Value (NPV) and the life time of fluvial Hot Sedimentary Aquifer (HSA) doublets. First, a sensitivity analysis is used to show the possible advantage of such reduction on the NPV. The parameter value ranges are derived from West Netherlands Basin HSA doublet examples. The results indicate that a reduction of well spacing from 1400 to 1000 m could already influence NPV by up to 15%. This effect would be larger in more marginally economic HSA doublets compared to the West Netherlands Basin base case scenario. The possibility to reduce well spacing is supported by finite element production simulations, utilizing detailed facies architecture models. Furthermore, our results underline the necessity of detailed facies architecture models to assess the potential and risks of HSA doublets. This factor significantly affects doublet life time and net energy production of the doublet

Micro-crystalline inclusions analysis by PIXE and RBS

A characteristic feature of the nuclear microprobe using a 3 MeV proton beam is the long range of particles (around 70 \mu m in light matrices). The PIXE method, with EDS analysis and using the multilayer approach for treating the X-ray spectrum allows the chemistry of an intra-crystalline inclusion to be measured, provided the inclusion roof and thickness at the impact point of the beam (Z and e, respectively) are known (the depth of the inclusion floor is Z + e). The parameter Z of an inclusion in a mineral can be measured with a precision of around 1 \mu m using a motorized microscope. However, this value may significantly depart from Z if the analyzed inclusion has a complex shape. The parameter e can hardly be measured optically. By using combined RBS and PIXE measurements, it is possible to obtain the geometrical information needed for quantitative elemental analysis. This paper will present measurements on synthetic samples to investigate the advantages of the technique, and also on natural solid and fluid inclusions in quartz. The influence of the geometrical parameters will be discussed with regard to the concentration determination by PIXE. In particular, accuracy of monazite micro-inclusion dating by coupled PIXE-RBS will be presented