Diffraction by a right-angled no-contrast penetrable wedge: recovery of far-field asymptotics

We provide a description of the far-field encountered in the diffraction problem resulting from the interaction of a monochromatic plane-wave and a right-angled no-contrast penetrable wedge. To achieve this, we employ a two-complex-variable framework and use the analytical continuation formulae derived in (Kunz $\&$ Assier, QJMAM, 76(2), 2023) to recover the wave-field's geometrical optics components, as well as the cylindrical and lateral diffracted waves. We prove that the corresponding cylindrical and lateral diffraction coefficients can be expressed in terms of certain two-complex-variable spectral functions, evaluated at some given points

Diffraction by a Right-Angled No-Contrast Penetrable Wedge: Analytical Continuation of Spectral Functions

We study the problem of diffraction by a right-angled no-contrast penetrable wedge by means of a two-complex-variable Wiener-Hopf approach. Specifically, the analyticity properties of the unknown (spectral) functions of the two-complex-variable Wiener-Hopf equation are studied. We show that these spectral functions can be analytically continued onto a two-complex dimensional manifold, and unveil their singularities in $\mathbb{C}^2$. To do so, integral representation formulae for the spectral functions are given and thoroughly used. It is shown that the novel concept of additive crossing holds for the penetrable wedge diffraction problem and that we can reformulate the physical diffraction problem as a functional problem using this concept

Diffraction by a Right-Angled No-Contrast Penetrable Wedge Revisited: A Double Wiener-Hopf Approach

In this paper, we revisit Radlow's innovative approach to diffraction by a penetra ble wedge by means of a double Wiener-Hopf technique. We provide a constructive way of obtaining his ansatz and give yet another reason for why his ansatz cannot be the true solution to the diffraction problem at hand. The two-complex-variable Wiener-Hopf equation is reduced to a system of two equations, one of which contains Radlow's ansatz plus some correction term consisting of an explicitly known integral operator applied to a yet unknown function, whereas the other equation, the compatibility equation, governs the behaviour of this unknown function

Bidirectional 868/915 MHz wireless module powered with energy harverster

In this paper, we present a work that allows bidirectional communications in the 868/915 MHz ISM bands, using the power generated by energy harvesters. Our investigations show that a clear channel assessment, receive of acknowledge and resend of the message are possible within a limited, but reasonable time. The design relies on the use of low power microcontrollers and transceivers, and low energy management techniques

Die postoperative Anämie ist ein unabhängiger Risikofaktor für das postoperative Delir und eine verlängerte Hospitalisierung

Die postoperative Anämie ist ein potenzieller Risikofaktor für das postoperative Delir und eine verlängerte Hospitalisierung: Sekundäranalyse einer prospektiven Kohortenstudie. Einleitung: Die postoperative Anämie ist eine häufige Komplikation im Rahmen eines chirurgischen Eingriffes. Im Gegensatz zur präoperativen Anämie gibt es hierzu weitaus weniger Daten zur Inzidenz und klinischen Relevanz. Durch eine potenzielle cerebrale Oxygenierungsstörung könnte die postoperative Anämie zum postoperativen Delir führen. Das Ziel dieser Sekundäranalyse ist, die Assoziation von postoperativer Anämie nach geschlechtsspezifischer Definition der World Health Organization und einen möglichen Zusammenhang zur Krankenhausverweildauer zu untersuchen. Methodik: Es wurde eine Subanalyse der 800 Patienten der multizentrischen CESARO-Studie durchgeführt. Hierbei handelt es sich um eine prospektive Observationsstudie von volljährigen Patienten, an denen ein elektiver nicht-kardialer chirurgischer Eingriff vorgenommen wurde. Die sieben teilnehmenden Zentren bestanden aus Universitätskliniken der Maximalversorgung, einem Kreiskrankenhaus sowie einer auf minimalinvasive Chirurgie spezialisierten Klinik. Es wurde die Definition der World Health Organization (WHO) für Anämie verwendet, laut der eine Hämoglobinkonzentration von weniger als 12g/dl beim weiblichen Geschlecht und beim männlichen Geschlecht von weniger als 13g/dl eine Anämie beschreibt. Der Fokus lag dabei auf der akuten postoperativen Anämie: Patienten mit vorbestehender präoperativer Anämie wurden ausgeschlossen. Das postoperative Delir wurde mit Hilfe der validierten Nursing Delirium Screening Scale mindestens bis 24 Stunden nach operativem Eingriff und maximal bis zum dritten postoperativen Tag gescreent. Ergebnisse: Bei 183 der 800 Patienten lag eine vollständige Dokumentation der prä- und postoperativen Hämoglobinkonzentration vor. Eine postoperative Anämie trat bei 90 Patienten auf. Dies entspricht einer Anämie-Inzidenz von 49,2%. Bei 10 der 93 (10.9%) Patienten, die keine postoperative Anämie erlitten, trat ein postoperatives Delir auf. In der Gruppe der Patienten mit postoperativer Anämie trat das postoperative Delir bei 28 (38,4%) Patienten auf (odds ratio 3,949 (95% Konfidenzintervall, (1,358-11,480), bereinigt für NYHA-Stadium, Schwere der Operation, Schnitt/Naht-Zeit, Dauer der Anästhesie, Transfusion von Erythrozytenkonzentraten und postoperativem Sedierungsstatus gemäß Richmond Agitation Scale. Darüber hinaus war die Krankenhausverweildauer bei Patienten mit postoperativer Anämie signifikant verlängert (7,75 vs. 12,42 Tagen, odds ratio = 1,186, 95% Konfidenzintervall, 1,083-1,299, nach Bereinigung). Schlussfolgerung: Die postoperative Anämie ist nicht nur eine häufige Komplikation mit fast 50% Inzidenz, sondern auch ein unabhängiger Prädiktor für postoperatives Delir und verlängerte Krankenhausverweildauer.Postoperative anaemia might be a risk factor for postoperative delirium and prolonged hospital stay: A secondary analysis of a prospective cohort study. Background: Postoperative anaemia is a frequent surgical complication and in contrast to preoperative anaemia has not been validated in relation to mortality, morbidity and its associated health economic effect. Postoperative anaemia can predispose postoperative delirium through impairment of cerebral oxygenation. The aim of this secondary analysis is to investigate the association of postoperative anaemia in accordance with the sex specific World Health Organization definition of anaemia to postoperative delirium and its impact on the duration of hospital stay. Methods: A secondary analysis of the prospective multicentric observational CESARO-study was conducted. 800 adult patients undergoing elective surgery were enrolled from various operative disciplines across seven hospitals ranging from university hospitals, district general hospitals to specialist clinics of minimally invasive surgery in Germany. Patients were classified as anaemic according to the World Health Organization parameters, setting the haemoglobin level cut off below 12g/dl for females and below 13g/dl for males. Focus of the investigation were patients with acute anaemia. Patients with present preoperative anaemia or missing haemoglobin measurement were excluded from the sample set. Delirium screening was established postoperatively for at least 24 hours and up to three days, applying the validated Nursing Delirium Screening Scale. Results: The initial sample set contained 800 patients of which 183 were suitable for analysis in the study. Ninety out of 183 (49.2%) suffered from postoperative anaemia. Ten out of 93 (10.9%) patients without postoperative anaemia developed a postoperative delirium. In the group with postoperative anaemia, 28 (38.4%) out of 90 patients suffered from postoperative delirium (odds ratio 3.949, 95% confidence interval, (1.358-11.480)) after adjustment for NYHA-stadium, severity of surgery, cutting/suture time, duration of anaesthesia, transfusion of packed red cells and sedation status with Richmond Agitation Scale after surgery. Additionally, patients who suffered from postoperative anaemia showed a significantly longer duration of hospitalisation (7.75 vs. 12.42 days, odds ratio = 1.186, 95% confidence interval, 1.083-1.299, after adjustments). Conclusion: The study results reveal that postoperative anaemia is not only a frequent postsurgical complication with an incidence probability of almost 50%, but could also be associated with a postoperative delirium and a prolonged hospitalisation[1]

Postoperative Anaemia Might Be a Risk Factor for Postoperative Delirium and Prolonged Hospital Stay: A Secondary Analysis of a Prospective Cohort Study

Background: Postoperative anaemia is a frequent surgical complication and in contrast to preoperative anaemia has not been validated in relation to mortality, morbidity and its associated health economic effect. Postoperative anaemia can predispose postoperative delirium through impairment of cerebral oxygenation. The aim of this secondary analysis is to investigate the association of postoperative anaemia in accordance with the sex specific World Health Organization definition of anaemia to postoperative delirium and its impact on the duration of hospital stay. Methods: A secondary analysis of the prospective multicentric observational CESARO-study was conducted. 800 adult patients undergoing elective surgery were enrolled from various operative disciplines across seven hospitals ranging from university hospitals, district general hospitals to specialist clinics of minimally invasive surgery in Germany. Patients were classified as anaemic according to the World Health Organization parameters, setting the haemoglobin level cut off below 12g/dl for females and below 13g/dl for males. Focus of the investigation were patients with acute anaemia. Patients with present preoperative anaemia or missing haemoglobin measurement were excluded from the sample set. Delirium screening was established postoperatively for at least 24 hours and up to three days, applying the validated Nursing Delirium Screening Scale. Results: The initial sample set contained 800 patients of which 183 were suitable for analysis in the study. Ninety out of 183 (49.2%) suffered from postoperative anaemia. Ten out of 93 (10.9%) patients without postoperative anaemia developed a postoperative delirium. In the group with postoperative anaemia, 28 (38.4%) out of 90 patients suffered from postoperative delirium (odds ratio 3.949, 95% confidence interval, (1.358-11.480)) after adjustment for NYHA-stadium, severity of surgery, cutting/suture time, duration of anaesthesia, transfusion of packed red cells and sedation status with Richmond Agitation Scale after surgery. Additionally, patients who suffered from postoperative anaemia showed a significantly longer duration of hospitalisation (7.75 vs. 12.42 days, odds ratio = 1.186, 95% confidence interval, 1.083-1.299, after adjustments). Conclusion: The study results reveal that postoperative anaemia is not only a frequent postsurgical complication with an incidence probability of almost 50%, but could also be associated with a postoperative delirium and a prolonged hospitalisation

Correlative Light- and Electron Microscopy with chemical tags

AbstractCorrelative microscopy incorporates the specificity of fluorescent protein labeling into high-resolution electron micrographs. Several approaches exist for correlative microscopy, most of which have used the green fluorescent protein (GFP) as the label for light microscopy. Here we use chemical tagging and synthetic fluorophores instead, in order to achieve protein-specific labeling, and to perform multicolor imaging. We show that synthetic fluorophores preserve their post-embedding fluorescence in the presence of uranyl acetate. Post-embedding fluorescence is of such quality that the specimen can be prepared with identical protocols for scanning electron microscopy (SEM) and transmission electron microscopy (TEM); this is particularly valuable when singular or otherwise difficult samples are examined. We show that synthetic fluorophores give bright, well-resolved signals in super-resolution light microscopy, enabling us to superimpose light microscopic images with a precision of up to 25nm in the x–y plane on electron micrographs. To exemplify the preservation quality of our new method we visualize the molecular arrangement of cadherins in adherens junctions of mouse epithelial cells