Leibniz University of Hanover

About: Leibniz University of Hanover is a education organization based out in Hanover, Niedersachsen, Germany. It is known for research contribution in the topics: Finite element method & Population. The organization has 14283 authors who have published 29845 publications receiving 682152 citations.

Biological aspects of root canal filling materials – histocompatibility, cytotoxicity, and mutagenicity

Abstract: In order to minimize the incidence of local and/or systemic side effects, the biocompatibility of all endodontic materials should be investigated by various in vitro and in vivo tests prior to clinical application. The battery of in vitro tests includes determinations of mutagenicity, cytotoxicity, and antibacterial effects. Several reports have shown that paraformaldehyde-containing ZnO-eugenol cements in particular, such as Endomethasone and N2, are antibacterial. On the other hand, it has been found that endodontic materials with strong antimicrobial activity are frequently mutagenic, i.e., primarily those which release formaldehyde. Cell culture tests clearly show significantly different cytocompatibility of the various types of endodontic sealers: in general, formaldehyde-containing ZnO-eugenol cements are classified as highly/extremely cytotoxic, whereas most Ca(OH)2-based sealers are rated as possessing good or excellent cytocompatibility. These results were confirmed by numerous histological studies in vivo. Sealers with inferior biocompatibility, such as formaldehyde-releasing materials, should no longer be applied in practice because safer alternatives are available.

Applying the Analytic Hierarchy Process in healthcare research: A systematic literature review and evaluation of reporting.

Abstract: The Analytic Hierarchy Process (AHP), developed by Saaty in the late 1970s, is one of the methods for multi-criteria decision making. The AHP disaggregates a complex decision problem into different hierarchical levels. The weight for each criterion and alternative are judged in pairwise comparisons and priorities are calculated by the Eigenvector method. The slowly increasing application of the AHP was the motivation for this study to explore the current state of its methodology in the healthcare context. A systematic literature review was conducted by searching the Pubmed and Web of Science databases for articles with the following keywords in their titles or abstracts: “Analytic Hierarchy Process,” “Analytical Hierarchy Process,” “multi-criteria decision analysis,” “multiple criteria decision,” “stated preference,” and “pairwise comparison.” In addition, we developed reporting criteria to indicate whether the authors reported important aspects and evaluated the resulting studies’ reporting. The systematic review resulted in 121 articles. The number of studies applying AHP has increased since 2005. Most studies were from Asia (almost 30 %), followed by the US (25.6 %). On average, the studies used 19.64 criteria throughout their hierarchical levels. Furthermore, we restricted a detailed analysis to those articles published within the last 5 years (n = 69). The mean of participants in these studies were 109, whereas we identified major differences in how the surveys were conducted. The evaluation of reporting showed that the mean of reported elements was about 6.75 out of 10. Thus, 12 out of 69 studies reported less than half of the criteria. The AHP has been applied inconsistently in healthcare research. A minority of studies described all the relevant aspects. Thus, the statements in this review may be biased, as they are restricted to the information available in the papers. Hence, further research is required to discover who should be interviewed and how, how inconsistent answers should be dealt with, and how the outcome and stability of the results should be presented. In addition, we need new insights to determine which target group can best handle the challenges of the AHP.

Moduli stabilization and cosmology of type IIB on SU(2)-structure orientifolds

Abstract: We consider type IIB flux compactifications on six-dimensional SU(2)-structure manifolds with O5- and O7-planes These six-dimensional spaces allow not only for F 3 and H 3 fluxes but also for F 1 and F 5 fluxes We derive the four-dimensional $$ \mathcal {N} $$ = 1 scalar potential for such compactifications and present one explicit example of a fully stabilized AdS vacuum with large volume and small string coupling We then discuss cosmological aspects of these compactifications and derive several no-go theorems that forbid dS vacua and slow-roll inflation under certain conditions We also study concrete examples of cosets and twisted tori and find that our no-go theorems forbid dS vacua and slow-roll inflation in all but one of them For the latter we find a dS critical point with ϵ numerically zero However, the point has two tachyons and eta-parameter η ≈ −31

Solar Light Responsive Poly(vinyl alcohol)-Assisted Hydrothermal Synthesis of Immobilized TiO2/Ti Film with the Addition of Peroxymonosulfate for Photocatalytic Degradation of Ciprofloxacin in Aqueous Media: A Mechanistic Approach

Abstract: This study is focused on the synthesis of a solar light driven novel poly(vinyl alcohol) (PVA)-assisted TiO2/Ti film via a facile one pot hydrothermal technique and then its photocatalytic applications by adding with peroxymonosulfate (PMS) for efficient degradation of ciprofloxacin (CIP). The key hydrothermal synthesis parameters like PVA-content, hydrothermal time (HT), and pH were optimized. The best photocatalytic performance of the synthesized material was observed when prepared with the conditions of PVA = 8 mg, HT = 3 h, and pH = 2.62. Results showed that 98.3% of CIP was degraded within 60 min by PVA-assisted TiO2/Ti film with 0.5 mM PMS added, compared to 89.38% and 88.86% degradation with 0.5 mM persulfate (PS) and 0.5 mM hydrogen peroxide (H2O2), respectively. The photocatalytic degradation of CIP by PVA-assisted TiO2/Ti film with PMS added was dependent on the [PMS]0 and increased with increase in [PMS]0. The kapp values at [PMS]0 of 0.2, 0.5, 0.8, and 1.0 mM were 0.029, 0.0582, 0.068, and 0.1...