Understanding polaritonic chemistry from ab initio quantum electrodynamics

In this review we present the theoretical foundations and first principles frameworks to describe quantum matter within quantum electrodynamics (QED) in the low-energy regime. Having a rigorous and fully quantized description of interacting photons, electrons and nuclei/ions, from weak to strong light-matter coupling regimes, is pivotal for a detailed understanding of the emerging fields of polaritonic chemistry and cavity materials engineering. The use of rigorous first principles avoids ambiguities and problems stemming from using approximate models based on phenomenological descriptions of light, matter and their interactions. By starting from fundamental physical and mathematical principles, we first review in great detail non-relativistic QED, which allows to study polaritonic systems non-perturbatively by solving a Schrödinger-type equation. The resulting Pauli-Fierz quantum field theory serves as a cornerstone for the development of computational methods, such as quantum-electrodynamical density functional theory, QED coupled cluster or cavity Born-Oppenheimer molecular dynamics. These methods treat light and matter on equal footing and have the same level of accuracy and reliability as established methods of computational chemistry and electronic structure theory. After an overview of the key-ideas behind those novel ab initio QED methods, we explain their benefits for a better understanding of photon-induced changes of chemical properties and reactions. Based on results obtained by ab initio QED methods we identify the open theoretical questions and how a so far missing mechanistic understanding of polaritonic chemistry can be established. We finally give an outlook on future directions within polaritonic chemistry and first principles QED and address the open questions that need to be solved in the next years both from a theoretical as well as experimental viewpoint

Exact Solution for A Real Polaritonic System Under Vibrational Strong Coupling in Thermodynamic Equilibrium: Absence of Zero Temperature and Loss of Light-Matter Entanglement

The first exact quantum simulation of a real molecular system (HD+) under strong ro-vibrational coupling to a quantized optical cavity mode in thermal equilibrium is presented. Theoretical challenges in describing strongly coupled systems of mixed quantum statistics (Bosons and Fermions) are discussed and circumvented by the specific choice of our molecular system. Our exact simulations reveal the absence of a zero temperature for the strongly coupled matter and light subsystems, due to cavity induced non-equilibrium conditions. Furthermore, we explore the temperature dependency of light-matter quantum entanglement, which emerges for the groundstate, but is quickly lost already in the deep cryogenic regime, opposing predictions from phenomenological models (Jaynes-Cummings). Distillable molecular light-matter entanglement of ro-vibrational states may open interesting perspectives for quantum technological applications. Moreover, we find that the dynamics (fluctuations) of matter remains modified by the quantum nature of the thermal and vacuum field fluctuations for significant temperatures, e.g. at ambient conditions. These observations (loss of entanglement and coupling to quantum fluctuations) has far reaching consequences for the understanding and control of polaritonic chemistry and materials science, since a semi-classical theoretical description of light-matter interaction becomes feasible, but the typical canonical equilibrium assumption for the nuclear dynamics remains broken. This opens the door for quantum fluctuations induced stochastic resonance phenomena under vibrational strong coupling. A plausible theoretical mechanism to explain the experimentally observed resonance phenomena in absence of periodic driving, which have not yet been understood

Use of a single bipolar electrode in the posterior arytenoid muscles for bilateral monitoring of the recurrent laryngeal nerves in thyroid surgery

The aims were to assess the technical feasibility of using a single electrode in the posterior arytenoid muscles (PAM) for intraoperative monitoring of the recurrent laryngeal nerve (RLN) in thyroid surgery, to validate the new method against the insertion of electrodes placed in the vocal cord muscle, and to report the results of the clinical application of the new concept. A total of 52 patients were enrolled. The handling and safety of RLN monitoring was tested by simultaneous registration of the EMG response from vocal fold electrodes and PAM electrodes. Acoustically and electromyographically we found nearly the same values for the arytenoid muscles as for the vocal folds, although the signals taken from the vocal folds were slightly stronger. PAM recording using a single bipolar electrode is technically feasible and as reliable compared to the standard vocal cord monitorin

Comparing Results of Concurrent and Retrospective Designs in a Hospital Utilization Review

Hospital utilization reviews are performed on the basis of lists of explicit criteria, such as the Appropriateness Evaluation Protocol, both concurrently and retrospectively, in an increasing number of settings as part of efforts to improve the performance of hospitals and to reduce health care costs. Retrospective data collection has advantages in terms of expenses and ease of sampling, but relies on the quality of medical records. We report on a comparison between concurrent and retrospective data collection performed simultaneously and independently by two reviewers on the same hospital stays in the regional St-Loup Hospital. Results suggest that retrospective data collection produces higher rates of inappropriate hospital utilization, due to a limited number of criteria that are recorded concurrently, but are not found in the retrospective reading of medical records. These results should encourage a further investigation of the comparability between concurrent and retrospective designs in other settings. © 1997 Elsevier Science Ltd. All rights reserve

A systematic review of the relationships between principal characteristics and student achievement

This report reviews studies that have investigated the relationships between principal characteristics (including precursors, behaviors, and leadership styles) and student achievement. Only one experimental study examined a principal intervention designed to improve student achievement. It found that grade 8 students randomly assigned to have one-on-one conversations with the principal scored higher on the state English language arts test. An additional 38 quantitative and 2 mixed method studies provided mixed evidence of the relationships between principal characteristics and student achievement; 11 qualitative studies mirrored the quantitative findings

Effect of herd health management on the prevalence of Postpartum Dysgalaktie Syndrome (PPDS) and the treatment incidence

The Postpartum Dysgalaktie Syndrome (PPDS) also known as metritis agalactia mastitis (MMA), is considered the most common disease of the sow after farrowing. The reasons for PPDS are multifactorial and are to be found in the areas of management and hygiene, feeding, water supply and animal specific factors such as body condition and age of the sows. In this study a veterinary herd health management was carried out in 28 pig farms with PPDS, with the aim to reduce the PPDS prevalence and animal treatment incidence (TI). In 20 of 28 problem farms the PPDS-prevalence could be decreased from 37.4% (± 21.8%) to 24.5% (± 14.1%). The TI was not significantly reduced. The most effective procedures to reduce the PPDS-prevalence were the use of a prepartal transition feed, optimizing the PPDSdiagnostic and the use of nonsteroidal antiinflammatory drugs (NSAID) and oxytocin in the PPDS-treatment

Kann die 18F-FDG-PET/CT-Untersuchung die Panendoskopie zur Detektion von synchronen Zweitkarzinomen ersetzen?

Ziel der Arbeit war es, die Wertigkeit der 18F-FDG-PET/ CT-Untersuchung bezüglich synchroner Zweitkarzinome im Vergleich mit der Panendoskopie beim initialen Staging zu untersuchen. 311 Patienten wurden mit beiden Untersuchungsmethoden abgeklärt. Als Referenz galt die zytologische, histologische und/oder klinische oder radiologische Untersuchung. Die Prävalenz für synchrone Zweitkarzinome betrug mit der Panendoskopie 4,5%, während die Prävalenz mittels PET/ CT-Untersuchung 6,1% betrug. Die Sensitivität für die Panendoskopie betrug 74%, die Spezifität 99,7%, der positiv prädiktive Wert 93% und der negativ prädiktive Wert 98%. Die Sensitivität für die PET/CT-Untersuchung betrug 100%, die Spezifität 95,7% der positiv prädiktive Wert 59% und der negativ prädiktive Wert 100%. Die PET/CT-Untersuchung scheint der Panendoskopie überlegen zu sein. Bei bezüglich synchroner Zweitkarzinome unauffälligem PET/CT kann die Panendoskopie auf die Endoskopie und Beurteilung des Primärtumors beschränkt werden kann. Aufgrund der hohen Kosten und der grossen Anzahl falsch positiver Resultate, welche durch das PET/CT generiert werden, empfehlen wir die Durchführung dieser Untersuchung nur bei fortgeschrittenen Tumoren mit der Frage nach Fernmetastasen. Die Panendoskopie bleibt weiterhin der Goldstandar

Thoracic versus abdominal approach to correct diaphragmatic eventration in children

Background: Plication of diaphragm (DP) for eventration (DE) can be done using thoracic or abdominal approaches. The purpose of our study was to compare outcomes between these approaches based on our experience and on systematic literature review. Methods: Retrospective records of children < 16 years who underwent DP (single-center, 2004–2018) were recorded and analyzed. Systematic review and meta-analysis of related studies was undertaken. Data are reported as median (range). Results: Eighty-nine cases were identified in thoracic (Congenital = 5, Acquired = 84) and 13 (Congenital = 10, Acquired = 3) in abdominal group aged 5.88 (0.36–184.44) and 10.0 (0.12–181.8) months. Improvement in diaphragm level post-DP was significantly higher in abdominal [2(0–4)] than chest [1.5(0–5)] group (p = 0.04). On Cox regression analysis, there was a non-significant trend to a longer time to extubation in the chest group (Hazard ratio (HR) = 0.539[0.208–1.395], p = 0.203). Patients operated transthoracically left intensive care unit after a significantly longer time (HR = 0.339[0.119–0.966], p = 0.043). Patients operated transabdominally tended to be fed later, although this was not significant (HR = 1.801[0.762–4.253], p = 0.043). On Kaplan–Meier analysis, there was a non-significant trend to a lower rate of recurrence in the abdominal group (HR = 0.3196[0.061–1.675], p = 0.1876). In the meta-analysis including three published studies as well as our data (total n = 181, Thoracic = 139, Abdominal = 42), no difference was found in the incidence of recurrence amongst the 2 groups (RD = -0.04, 95%CI = -0.25, 0.18, p = 0.74). Conclusion: This is one of the largest reports on outcomes of children undergoing DP for DE. There is no significant difference in recurrence rate, even though all recurrences in our series (15.7%) were in the acquired cases operated using a thoracic approach

Potential benefits of laparoscopic repair of duodenal atresia: Insights from a retrospective comparative study

Introduction: Congenital duodenal obstruction (CDO) repair can be performed open or laparoscopically. We aimed to determine the potential benefit of laparoscopic repair regarding tolerance of enteral feeding, postoperative pain, hospital stay, and complication rate. Materials and Methods: In a single-center retrospective cohort study, we compared neonates with isolated CDO operated open versus laparoscopically from 2010 to 2019. No transanastomotic tubes were used, and anastomoses were created in a side-to-side fashion in all cases. An early feeding policy is applied for all cases operated at our institution. Statistical comparison was performed using the Mann–Whitney's test or Fisher's exact test where appropriate. Results Forty-one patients analyzed were similar regarding body weight, gestational age, and proportion of patients with trisomy 21. Median follow-up was 21 months. Four (20%) out of 20 laparoscopic procedures started laparoscopically were converted to open. Comparing the 21 open with the 16 laparoscopically completed patients, median anesthetic duration was shorter by 18% in the open versus laparoscopic completed group (218 vs. 179 minutes, respectively; p = 0.025). Median postoperative time to full enteral feeds was shorter by 4 days in the first group (7 vs. 11 days, respectively; p = 0.028). In accordance, the median duration of parenteral nutrition (PN) was less than half in the laparoscopic completed compared with the open group (5 vs. 11.5 days, respectively; p = 0.031). Postoperative opioids were required for only half the duration in the laparoscopically completed group compared with open (2 vs. 4 days, respectively; p = 0.026). Outcomes such as length of stay, the occurrence of strictures or adhesions requiring reintervention, or line sepsis were similar in both groups. Conclusion: Patients undergoing laparoscopic CDO repair at our institution benefited from shorter time to full enteral feeds, and reduced the need for PN as well as postoperative pain medication