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

Radio and thermoluminescence studies in CsI doped with F centers

Radioluminescence, thermoluminescence, and u.v. excitation measurements in CsI additively colored crystals showed a new luminescent component at 2.5 eV. This is attributed to the radiative recombination of Vk centers with F centers. Another new component at 2.72 eV was observed only under uv excitation of 5.14 eV. This is related to the radiative recombination of localized excitons at F+ center sites (α band)

Study of Vk centers in CsI crystals

Vk centers were observed in CsI doped with Na+ and Tl+ after x-ray irradiation at liquid He temperature by using optical and EPR techniques. They are oriented along [100] directions. By studying thermoluminescence, 2 types of thermal migration were found, one due to linear displacement of the centers along the cubic axis and the other due to 90° rotations. They correspond to 2 glow peaks at 60 and 90°K, respectively

Situs inversus abdominalis and duodenal atresia. A case report and review of the literature

Fewer than 20 patients born with situs inversus and duodenal atresia have been reported in the literature. We present a patient with this condition. A newborn baby presented shortly after birth with persistent bilious vomiting. An abdominal radiograph showed a right-sided stomach bubble and a second bubble on the left - typical of duodenal atresia but with mirror image configuration. Laparotomy confirmed the diagnosis of situs inversus abdominalis, which was also demonstrated by contrast studies and ultrasound. Duodenoduodenostomy was performed and the patient discharged on day 8 postoperatively. Situs inversus is associated with other congenital malformations including splenic malformations, left-sided liver and cardiac abnormalities; it is rarely associated with duodenal atresia. Duodenal obstruction in the presence of situs inversus has been described, including obstruction due to a web, stenosis, pre-duodenal portal vein and complete atresia. The patient presented in this paper had a duodenal web in the second part of the duodenum. Before undertaking surgery it is important to establish the presence of associated gastrointestinal and cardiac abnormalities

Non-invasive voiding assessment in conscious mice

OBJECTIVE: To review available options of assessing murine bladder function and to evaluate a non-invasive technique suitable for long-term recording. METHODS: We reviewed previously described methods to record rodent bladder function. We used modified metabolic cages to capture novel recording tracings of mouse micturition. We evaluated our method in a pilot study with female mice undergoing partial bladder outlet obstruction or sham operation, respectively; half of the partial obstruction and sham group received treatment with an S6K-inhibitor, targeting the mTOR pathway, which is known to be implicated in bladder response to obstruction. RESULTS: Our non-invasive method using continuous urine weight recording reliably detected changes in murine bladder function resulting from partial bladder outlet obstruction or treatment with S6K-inhibitor. We found obstruction as well as treatment with S6K-inhibitor to correlate with a hyperactive voiding pattern. CONCLUSIONS: While invasive methods to assess murine bladder function largely disturb bladder histology and intrinsically render post-cystometry gene expression analysis of questionable value, continuous urine weight recording is a reliable, inexpensive, and critically non-invasive method to assess murine bladder function, suitable for a long-term application

Ventricular pre-excitation in cats: 17 cases

Objectives: Atrioventricular accessory pathways are abnormal electrical connections between the atria and ventricles that predispose to ventricular pre-excitation (VPE) and tachycardias. Animals: Seventeen cats with VPE and 15 healthy matched-control cats. Material and methods: Multicenter case-control retrospective study. Clinical records were searched for cats with VPE, defined as preserved atrioventricular synchrony, reduced PQ interval, and increased QRS complex duration with a delta wave. Clinical, electrocardiography, echocardiographic, and outcome data were collated. Results: Most cats with VPE were male (16/17 cats), non-pedigree cats (11/17 cats). Median age and mean body weight were 5.4 years (0.3-11.9 years) and 4.6 ± 0.8 kg, respectively. Clinical signs at presentation included lethargy (10/17 cats), tachypnea (6/17 cats), and/or syncope (3/17 cats). In two cats, VPE was an incidental finding. Congestive heart failure was uncommon (3/17 cats). Nine (9/17) cats had tachyarrhythmias: 7/9 cats had narrow QRS complex tachycardia and 2/9 cats had wide QRS complex tachycardia. Four cats had ventricular arrhythmias. Cats with VPE had larger left (P < 0.001) and right (P < 0.001) atria and thicker interventricular septum (P = 0.019) and left ventricular free wall (P = 0.028) than controls. Three cats had hypertrophic cardiomyopathy. Treatment included different combinations of sotalol (5/17 cats), diltiazem (5/17 cats), atenolol (4/17 cats), furosemide (4/17 cats), and platelet inhibitors (4/17 cats). Five cats died, all from cardiac death (median survival time 1882 days [2-1882 days]). Conclusions: Cats with VPE had a relatively long survival, albeit showing larger atria and thicker left ventricular walls than healthy cats

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

Project PathoPig—A practical approach to strengthen post mortem analyses and early detection of pig diseases and zoonoses

Post mortem examinations are important for early detection and diagnosis of animal diseases and zoonoses. Over the last ten years, the number of necropsies in livestock has decreased considerably in Switzerland. To counteract this decline, the Federal Food Safety and Veterinary Office (FSVO) launched a project in 2014 called PathoPig. The aim is to evaluate the significance of pathologic-anatomical examinations for early detection of pig diseases and to investigate the impact of the findings on the improvement of pig health. Pig producers can participate if at least one of the following criteria is fulfilled: high morbidity and/or high mortality, unusual clinical signs, recurrent problems of unknown aetiology resistant to therapy or increased use of antimicrobials. Accordingly, the veterinarian examines the herd, fills in a standardised anamnesis protocol and submits one to three pigs representing the health problem to a designated pathology laboratory. After post mortem examination, the veterinarian offers specific recommendations to the farmer. Three to six months later, the Swiss Pig Health Service (SPHS) follows up the success of the veterinary recommendations. In 2014, 371 farms submitted pigs for PathoPig. In 84% of these cases, a conclusive diagnosis was obtained. In 56% of the cases, gastrointestinal problems were determined, most often (44%) caused by pathogenic Escherichia coli. In more than 80% of the cases, the animal health status could be improved considerably after the veterinary consultation. Increased post mortem examinations allowed more specific therapeutic treatments and management recommendations. Additionally, an improvement of collaboration between diagnostic laboratories, veterinarians and producers was achieved, thereby strengthening disease awareness and early detection of pig diseases and zoonoses in Switzerland