77 research outputs found

    Spin-selective electron transmission through self-assembled monolayers of double-stranded peptide nucleic acid

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    Monolayers of chiral molecules can preferentially transmit electrons with a specific spin orientation, introducing chiral molecules as efficient spin filters. This phenomenon is established as chirality-induced spin selectivity (CISS) and was demonstrated directly for the first time in self-assembled monolayers (SAMs) of double-stranded DNA (dsDNA)1. Here, we discuss SAMs of double-stranded peptide nucleic acid (dsPNA) as a system which allows for systematic investigations of the influence of various molecular properties on CISS. In photoemission studies, SAMs of chiral, γ-modified PNA show significant spin filtering of up to P = (24.4 ± 4.3)% spin polarization. The polarization values found in PNA lacking chiral monomers are considerably lower at about P = 12%. The results confirm that the preferred spin orientation is directly linked to the molecular handedness and indicate that the spin filtering capacity of the dsPNA helices might be enhanced by introduction of chiral centers in the constituting peptide monomers

    Transrectus sheath pre-peritoneal (TREPP) procedure versus totally extraperitoneal (TEP) procedure and Lichtenstein technique:a propensity-score-matched analysis in Dutch high-volume regional hospitals

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    PURPOSE: Results of the most commonly used inguinal hernia repair techniques often originate from expert centers or from randomized controlled studies. In this study, we portray daily-practice results of a high-volume, regional surgical group in the Netherlands, comparing TREPP (open (posterior) transrectus sheath pre-peritoneal) with Lichtenstein (open anterior) and TEP (endoscopic (posterior) totally extraperitoneal). We hypothesize that the TREPP shows more favorable outcome compared to the current gold standard procedures: TEP and Lichtenstein. METHODS: Between January 2016 and December 2018, 3285 consecutive patients underwent surgical treatment and were included for analysis. The outcome measures were postoperative pain, recurrence rate and other surgical complications. Propensity-score matching was used to address potential selection bias. RESULTS: After propensity-score matching, there was no statistically significant difference in postoperative pain in the TREPP group compared to the Lichtenstein group (TREPP 7.3% versus Lichtenstein 6.3%; p = 0.67) nor in TREPP compared to TEP (TREPP 7.4% versus TEP 4.1%; p = 0.064). There was no statistically significant difference in recurrences in the TREPP group compared to Lichtenstein (3.8% vs 2.5%; p = 0.42), nor in the TREPP versus TEP comparison (3.9% vs 2.8%; p = 0.55) CONCLUSION: This study compares TREPP with Lichtenstein and TEP in the presence of postoperative pain, recurrences and other adverse outcomes. After propensity-score matching, no statistically significant difference in postoperative pain or recurrences remained between either TREPP compared to Lichtenstein, or TREPP compared to TEP. Based on these results, TREPP, Lichtenstein and TEP showed comparable results in postoperative pain, recurrences and other surgical site complications

    Infectieziektensyndroom-surveillance bij asielzoekers.

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    In 2015 registreerden zich ruim 1,3 miljoen asielzoekers in de EU+ (Europese Unie, Noorwegen en Zwitserland). (1) Naar verwachting zal de instroom van asielzoekers de de komende jaren aanzienlijk blijven. (2

    Appropriate governance responses to infectious disease threats: Developing working hypotheses

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    Infectious diseases remain a threat to public health in today's interconnected world. There is an ongoing debate on how responses to threats of infectious diseases can best be coordinated, and the field remains nascent in understanding which specific structural governance arrangement will perform best. The present paper contributes to this discussion by demonstrating that it is possible to develop working hypotheses specifying the relationship between the type of infectious disease crisis and type of response to the crisis. For type of crises and type of response mechanisms there is still a lack of research, but the hypothesis combining these two provide a perspective for a future research and action agenda. It certainly prevents us from choosing between schism or hypes when it comes to crisis response. It provides instruments to realize that no single type of response is the most effective and that not all responses are equally effective in a concrete case
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