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Developing synthetic sandstones using geopolymer binder for constraining coupled processes in porous rocks
Get PDFThere is a current need for developing improved synthetic porous materials for better constraining the dynamic and coupled processes relevant to the geotechnical use of underground reservoirs. In this study, a low temperature preparation method for making synthetic rocks is presented that uses a geopolymer binder cured at 80 °C based on alkali-activated metakaolin. For the synthesised sandstone, the key rock properties permeability, porosity, compressive strength, and mineralogical composition, are determined and compared against two natural reservoir rocks. In addition, the homogeneity of the material is analysed structurally by micro-computed tomography and high-resolution scanning electron microscopy, and chemically by energy dispersive X-ray spectroscopy. It is shown that simple, homogenous sandstone analogues can be prepared that show permeability-porosity values in the range of porous reservoir rocks. The advance in using geopolymer binders to prepare synthetic sandstones containing thermally sensitive minerals provides materials that can be easily adapted to specific experimental needs. The use of such material in flow-through experiments is expected to help bridge the gap between experimental observations and numerical simulations, leading to a more systematic understanding of the physio-chemical behaviour of porous reservoir rocks
Development of Test Programs for the Biorelevant Characterization of Esophageal-Applied Dosage Forms
Get PDFIn the local treatment of the esophageal mucosa, the retention time of the different dosage forms, such as tablets, films or liquids, is of high relevance for the effective treatment of diseases. Unfortunately, there are only few in vitro models describing the esophageal route of administration. To predict the behaviour of an esophageal-applied dosage form, it is necessary to simulate the site of application in a biorelevant way. The aim of this work was to develop two test setups for an esophageal peristalsis model which was described in a previous study. Different parameters such as flow rate, peristalsis, angle of inclination or mucous membrane were varied or introduced into the model. A stimulated and unstimulated modus were developed and tested with two different dosage forms. The time until the dosage form was cleared from the in vitro model was shorter with the stimulated than with the unstimulated modus. Also, esophageal-applied films had a prolonged transit time compared to a viscous syrup. The modification of the simulated esophageal surface made it possible to estimate the retention time of the dosage forms. It could be demonstrated that the residence time of a dosage form depends on different parameters affecting each other
Sustaining medical research – the role of trust and control
Get PDFBackground
Medical research is increasingly interdisciplinary. However, not all projects are successful and cooperation is not always sustained beyond the end of funding. This study empirically assesses the effect of control and trust on the sustainability of interdisciplinary medical research in terms of its performance and satisfaction.
Methods
The sample consists of 100 German publicly funded medical research collaborations with scientists from medicine, natural and social sciences (N = 364). We develop a system model to analyze the influence of trust and control on performance and satisfaction of the cooperation.
Findings
Both control and trust are important prerequisites for sustainability, control mainly for the performance of the collaboration, and trust primarily for its satisfaction. While the level of interdisciplinarity is a positive moderator for performance, expectation of continuity is a negative intervening variable for the effect of trust and control on satisfaction. Moreover, trust principally adds to the positive impact of control on sustainability.
Conclusions
Interdisciplinary medical research requires a participative but systematic management of the respective consortium
A Hairpin Ribozyme Derived Spliceozyme
Get PDFThe vast majority of RNA splicing in today‘s organisms is achieved by the highly regulated and precise removal of introns from pre-mRNAs via the spliceosome. Here we present a model of how RNA splicing may have occurred in earlier life forms. We have designed a hairpin ribozyme derived spliceozyme that mediates two RNA cleavages and one ligation event at specific positions and thus cuts a segment (intron) out of a parent RNA and ligates the remaining fragments (exons). The cut-out intron then performs a downstream function, acting as a positive regulator of the activity of a bipartite DNAzyme. This simple scenario shows how small RNAs can perform complex RNA processing dynamics, involving the generation of new phenotypes by restructuring segments of given RNA species, as well as delivering small RNAs that may play a functional role in downstream processes
Die Bedeutung von petechialen Einblutungen im Gesichtsbereich bei der zweiten Leichenschau vor der Feuerbestattung im Einzugsbereich des Instituts für Rechtsmedizin Greifswald
Get PDFDie zweite Leichenschau vor der Feuerbestattung dient im Wesentlichen der Erkennung von nichtnatürlichen Todesfällen, die im Rahmen der ersten Leichenschau nicht als solche erkannt wurden. Immer wieder fallen dabei punktförmige Einblutungen im Gesichtsbereich, insbesondere in die Lid- und Lidbindehäute auf. Neben krankhaften und lagebedingten Ursachen können diese Einblutungen der einzige äußerlich erkennbare Hinweis auf eine stattgehabte Halskompression sein. Bei Feststellung derartiger Einblutungen im Rahmen der zweiten Leichenschau wird der Sterbefall „angehalten“ und bei der Kriminalpolizei angezeigt. Für einen 12-Jahres-Zeitraum (2010–2021) wurden retrospektiv alle angehaltenen Sterbefälle mit festgestellten Petechien analysiert. In diesem Zeitraum wurden in den Krematorien, für die das Institut für Rechtsmedizin Greifswald verantwortlich ist, insgesamt 2822 Sterbefälle angehalten. In 282 Fällen erfolgte diese Anhaltung aufgrund petechialer Einblutungen im Gesichtsbereich. Durch die zuständige Staatsanwaltschaft wurde in 47 % dieser Fälle eine gerichtliche Obduktion angeordnet. Im Beobachtungszeitraum fanden sich 2 Tötungsdelikte, die erst durch die zweite Leichenschau vor der Feuerbestattung im Krematorium festgestellt wurden. Die Untersuchung zeigt, dass petechiale Einblutungen als Anhaltspunkt für einen nichtnatürlichen Tod nicht ausreichend bei Leichenschauärzten bekannt sind.The primary purpose of a second postmortem external examination is to identify unnatural deaths that were not determined as such during the first postmortem external examination. Petechial hemorrhages in the face, especially in the eyelids and eyelid conjunctiva, are noticed repeatedly. In addition to pathological and position-related causes, these petechial hemorrhages can be the only externally recognizable indication of a neck compression. When such hemorrhages are found during the second postmortem external examination, the cremation-process is halted and the case of death is reported to the criminal police. For a period of 12 years (2010–2021) all cases of death with detected petechial hemorrhages were analyzed retrospectively. During this period a total of 2822 cases of deaths were stopped in the crematoria for which the Greifswald Institute for Forensic Medicine is responsible. In 282 cases, the cremation process was stopped because of petechial hemorrhages in the face. In 47% of these cases the public prosecutor in charge ordered a forensic autopsy. During the observation period two homicides were found, which were only identified by the second postmortem external examination before the cremation. The study shows that petechial hemorrhages are not well known to physicians as an indication of unnatural death
Entwicklung von Qualitätsindikatoren für die Versorgung von Patient:innen mit chronischer Nierenerkrankung: Ergebnisse einer strukturierten Konsensfindung mittels Delphi-Verfahrens
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Die chronische Nierenkrankheit (CKD) ist eine häufige Erkrankung, insbesondere im höheren Alter. Um der Progression der Erkrankung und deren Komplikationen vorzubeugen, ist eine leitliniengerechte ambulante Versorgung von Patient:innen mit CKD anzustreben. Zur Messung und Bewertung der Versorgungsqualität können Qualitätsindikatoren (QI) genutzt werden. In Deutschland existieren bisher keine QI für CKD. Ziel der Arbeit war die Entwicklung von QI für die Qualitätsüberprüfung der ambulanten Versorgung von Patient:innen über 70 Jahren mit nichtdialysepflichtiger CKD.
Material und Methoden
Auf Grundlage der nationalen S3-Leitlinie CKD und eines Reviews internationaler QI wurde eine Liste von QI erstellt. Die ausgewählten QI wurden in 2 Sets eingeteilt: basierend auf Routinedaten (z. B. Abrechnungsdaten der Krankenkassen) und auf Datenerhebung in der Praxis (Chart-Review). Expert:innen verschiedener Fachrichtungen sowie ein Patient:innenvertreter bewerteten diese in einem Delphi-Verfahren mit 2‑stufiger Onlinebefragung im Oktober 2021 und Januar 2022 und abschließender Konsensuskonferenz im März 2022. Zusätzlich wurden Ranglisten der wichtigsten QI von jedem Set erstellt.
Ergebnisse
Ein Inzidenz- und ein Prävalenzindikator wurden a priori festgelegt und standen nicht zur Abstimmung. Weitere 21 QI standen zur Abstimmung durch die Expert:innen. Für jedes QI-Set wurden die 7 wichtigsten Indikatoren ausgewählt. Nur 1 QI wurde von dem Expert:innenpanel für den zusätzlichen Einsatz bei Erwachsenen unter 70 Jahren als nicht geeignet eingestuft.
Diskussion
Die QI sollen es ermöglichen, die Qualität der ambulanten Versorgung von Patient:innen mit CKD zu untersuchen, mit dem Ziel, die leitlinienkonforme ambulante Versorgung zu optimieren.Background
Chronic kidney disease (CKD) is a common condition, especially in the elderly. In order to prevent progression and complications of the disease, guideline-adherent outpatient care of patients with CKD should be prioritized. Quality indicators (QIs) can be used to measure and evaluate the quality of ambulatory care for patients with CKD. QIs specifically made for evaluating CKD care in Germany are not yet available. The goal of this work was to develop QIs for the quality assessment of outpatient care for patients over the age of 70 with CKD not requiring dialysis.
Materials and methods
QIs were operationalized from the recommendations of the German national guideline for CKD and others were proposed based on a published review of international QIs. The resulting QIs were divided into sets based on routine data (e.g., health insurance billing data) and data collection in practices (chart review). A panel of experts from various disciplines as well as a patient representative evaluated the proposed QIs in a two-stage Delphi process via online survey in October 2021 and January 2022 and a final consensus conference in March 2022. In addition, ranking lists of the most important QIs from each set were created.
Results
An incidence indicator and a prevalence indicator were established; these were not subject to vote. Further, 21 QIs were voted upon by the expert panel. The seven most important QIs in each set (billing data or chart review) were selected. Only one QI was rated by the expert panel as not suitable for additional use in adults under the age of 70 years.
Discussion
The QIs will enable the evaluation of the quality of outpatient care for patients with CKD with the long-term aim of optimizing guideline-adherent outpatient care
Akzeptanz grenzüberschreitender Rettungsdiensteinsätze
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Um eine grenzüberschreitende Notfallversorgung zwischen Deutschland und Polen zu etablieren, ist die Einbeziehung aller Stakeholder notwendig. Diese Forschungsarbeit erfasste erstmalig die Akzeptanz zur Versorgung durch einen ausländischen Rettungsdienst aus Bevölkerungsperspektive.
Methodik
An der qualitativen Befragung nahmen insgesamt 422 Personen aus Deutschland und Polen teil. Die strukturierten Interviews wurden mithilfe eines Befragungsleitfadens durchgeführt, elektronisch dokumentiert und für weitere Analysen kategorisiert.
Ergebnisse
99 % der deutschen Befragten und 97 % der polnischen Befragten waren dazu bereit, sich in einem medizinischen Notfall auch von einem Rettungsdienst des Nachbarlandes versorgen zu lassen, wenn dieser schneller bei ihnen sein kann als der heimische Rettungsdienst. Darüber hinaus konnten zahlreiche Herausforderungen erfasst werden, die die Interaktion zwischen dem Rettungsteam und den Betroffenen erschweren können. Hierbei wurden vor allem Sprachbarrieren, Unsicherheiten zur Finanzierung der Behandlungskosten und unterschiedliche medizinische Standards genannt. Um diesen Herausforderungen entgegenzuwirken, formulierte ein Großteil der Befragten mögliche Lösungsansätze.
Diskussion
Trotz der Herausforderungen, die mit einer grenzüberschreitenden Notfallversorgung einhergehen können, sind über 97 % der Befragten dazu bereit, sich auch von einem ausländischen Rettungsdienst versorgen zu lassen. Eine schnelle Versorgung wird von den Befragten deutlich höher priorisiert als die damit verbundenen Herausforderungen.Background
To establish cross-border emergency medical services between Germany and Poland, it is necessary to involve all stakeholders. Our research is the first empirical study to record the recipient population’s acceptance of emergency care delivered by foreign rescue services.
Materials and methods
A total of 422 people from Germany and Poland participated in the qualitative survey. Structured interviews were conducted using a protocol. The answers were electronically recorded and then categorized for analysis.
Results
Overall, 99% and 97% of German and Polish respondents, respectively, were willing to seek medical care from a neighboring country’s emergency medical service if it could be reached faster than the domestic one. Several challenges that may complicate interaction between the rescue team and the affected persons were identified. In particular, language barriers, uncertainties about financing of treatment costs, and different medical standards were mentioned. To counteract these challenges, most respondents had formulated potential solutions.
Conclusion
Despite the challenges that cross-border emergency care can entail, more than 97% of respondents are willing to seek care from a foreign emergency medical service. Quick care was given much higher priority by respondents than the associated challenges
Association of plasma chemerin with all-cause and disease-specific mortality – results from a population-based study
Get PDFBackground and objectives
Various cross-sectional studies have observed an association between high circulating concentrations of the adipokine chemerin and an unfavorable metabolic profile. However, the prognostic value of chemerin for the risk of associated diseases and mortality was examined only in a few studies mostly using small and highly selected patient populations. We aimed to analyze the association between plasma chemerin concentrations and all-cause as well as cause-specific mortality in the general population.
Study design and methods
From the Study of Health in Pomerania (SHIP), participants of two independent cohorts (SHIP-START-1 [n = 3037], SHIP-TREND-0 [n = 4193]) were followed up for 15 and 9 years (median), respectively. The association between plasma chemerin and all-cause mortality was analyzed using multivariable Cox proportional hazard regression models. Additionally, cause-specific hazards for cardiovascular disease (CVD) and cancer mortality were modeled considering competing events.
Results
A total number of 507 and 208 deaths occurred during follow-up in SHIP-START-1 and SHIP-TREND-0, respectively. Multivariable regression analyses revealed a significant association between high plasma chemerin concentrations and greater overall mortality that was independent of major confounders. Each 30 ng/mL increase in chemerin was associated with a 17% higher risk of all-cause mortality (95%-confidence interval: 1.10–1.26). Cause-specific analyses further showed that the chemerin concentration was significantly associated with cancer mortality but not with CVD mortality.
Conclusion
The present study detected a positive association between plasma chemerin concentrations and all-cause mortality in a large population-based study sample. Cause-specific analyses have shown that chemerin is likely to play a decisive role in cancer-related deaths. However, a direct association with cardiovascular mortality could not be established
Powered tooth brushes are beneficial for long-term oral health: Results from the Study of Health in Pomerania (SHIP-TREND)
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To determine the long-term effects of the use of powered tooth brush (PTB) in comparison to manual tooth brush (MTB) on periodontitis severity, coronal caries experience, and the number of missing teeth using in a population-based cohort study.
Materials and Methods
Using 7-year follow-up data of 2214 participants of the Study of Health in Pomerania (SHIP-TREND), comprehensively adjusted linear models using generalized least squares and ordinal regression models estimated the effects of PTB usage on dental outcomes in complete case and imputed data.
Results
At follow-up, PTB users had lower medians for mean probing depth (PD; 2.21 mm) and mean clinical attachment levels (1.73 mm) than MTB users (2.30 and 1.96 mm, respectively). Adjusted models revealed the beneficial effects of PTB usage on follow-up levels of plaque, bleeding on probing, mean PD, percentage of sites with PDs ≥4 mm, mean clinical attachment levels (all, interdental, and non-interdental sites, respectively), and the number of missing teeth. For the number of missing teeth, the effects were more pronounced in participants aged ≥50 years. No significant effects of PTB usage on the number of decayed or filled surfaces (all and interdental sites) were found.
Conclusions
A recommendation of PTB usage in dental practice could contribute to the long-term promotion of oral health
Circulating MicroRNAs as Biomarker for Vessel-Associated Retinal Diseases
Get PDFIntroduction: Vessel-associated retinal diseases are a major cause of blindness and severe visual impairment. The identification of appropriate biomarkers is of great importance to better anticipate disease progression and establish more targeted treatment options. MicroRNAs (miRNAs) are short, single-stranded, noncoding ribonucleic acids that are involved in the posttranscriptional regulation of gene expression through hybridization with messenger RNA. The expression of certain miRNAs can be different in patients with pathological processes and can be used for the detection and differentiation of various diseases. In this study, we investigate to what extent previously in vitro identified miRNAs are present as cell-free circulating miRNAs in the serum and vitreous of human patients with and without vessel-associated retinal diseases. Methods: Relative quantification by quantitative real-time polymerase chain reaction was used to analyze miRNA expression in patients with vessel-associated retinal diseases such as age-related macular degeneration (AMD), diabetic retinopathy (DR), and retinal vein occlusion compared with control patients. Results: In serum samples, miR-29a-3p and miR-192-5p showed increased expression in patients with neovascular AMD relative to control patients. Similarly, miR-335-5p, miR-192-5p, and miR-194-5p showed increased expression in serum from patients with proliferative DR. In vitreous samples, miR-100-5p was decreased in patients with proliferative DR. Differentially expressed miRNAs showed good diagnostic accuracy in receiver operating characteristic (ROC) and area under the ROC curve analysis. Conclusion: The miRNAs investigated in this study may have the potential to serve as biomarkers for vessel-associated retinal diseases. Combining multiple miRNAs may enhance the predictive power of the analysis