Observation of Three-Photon Spontaneous Parametric Down-Conversion in a Superconducting Parametric Cavity

Spontaneous parametric down-conversion (SPDC) has been a key enabling technology in exploring quantum phenomena and their applications for decades. For instance, traditional SPDC, which splits a high-energy pump photon into two lower-energy photons, is a common way to produce entangled photon pairs. Since the early realizations of SPDC, researchers have thought to generalize it to higher order, e.g., to produce entangled photon triplets. However, directly generating photon triplets through a single SPDC process has remained elusive. Here, using a flux-pumped superconducting parametric cavity, we demonstrate direct three-photon SPDC, with photon triplets generated in a single cavity mode or split between multiple modes. With strong pumping, the states can be quite bright, with flux densities exceeding 60 photons per second per hertz. The observed states are strongly non-Gaussian, which has important implications for potential applications. In the single-mode case, we observe a triangular star-shaped distribution of quadrature voltages, indicative of the long-predicted "star state." The observed state shows strong third-order correlations, as expected for a state generated by a cubic Hamiltonian. By pumping at the sum frequency of multiple modes, we observe strong three-body correlations between multiple modes, strikingly, in the absence of second-order correlations. We further analyze the third-order correlations under mode transformations by the symplectic symmetry group, showing that the observed transformation properties serve to "fingerprint" the specific cubic Hamiltonian that generates them. The observed non-Gaussian, third-order correlations represent an important step forward in quantum optics and may have a strong impact on quantum communication with microwave fields as well as continuous-variable quantum computation

Structure-activity relationships of novel substituted naphthalene diimides as anticancer agents

Novel 1,4,5,8-naphthalenetetracarboxylic diimide (NDI) derivatives were synthesized and evaluated for their antiproliferative activity on a wide number of different tumor cell lines. The prototypes of the present series were derivatives 1 and 2 characterized by interesting biological profiles as anticancer agents. The present investigation expands on the study of structure-activity relationships of prototypes 1 and 2, namely, the influence of the different substituents of the phenyl rings on the biological activity. Derivatives 3-22, characterized by a different substituent on the aromatic rings and/or a different chain length varying from two to three carbon units, were synthesized and evaluated for their cytostatic and cytotoxic activities. The most interesting compound was 20, characterized by a linker of three methylene units and a 2,3,4-trimethoxy substituent on the two aromatic rings. It displayed antiproliferative activity in the submicromolar range, especially against some different cell lines, the ability to inhibit Taq polymerase and telomerase, to trigger caspase activation by a possible oxidative mechanism, to downregulate ERK 2 protein and to inhibit ERKs phosphorylation, without acting directly on microtubules and tubuline. Its theoretical recognition against duplex and quadruplex DNA structures have been compared to experimental thermodynamic measurements and by molecular modeling investigation leading to putative binding modes. Taken together these findings contribute to define this compound as potential Multitarget-Directed Ligands interacting simultaneously with different biological targets. \ua9 2012 Elsevier Masson SAS. All rights reserved

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Craneal [Cranial] Anatomy Of Akodon Albiventer (Rodentia, Muridae, Sigmodontinae)

Volume: 88Start Page: 33End Page: 5

Historical Biogeography of a Clade of Liolaemus (Iguania: Liolaemidae) based on ancestral areas and dispersal-vicariance analysis (DIVA)

Although many phylogenetic studies have been made on the genus Liolaemus, they are inappropriate for a biogeographic study because of incomplete taxon sampling. Here we develop a biogeographic analysis using a new phylogenetic study of the chiliensis group, which differs from the other studies in having his members fully represented. The biogeographic analysis presented here consists in reconstructing the ancestral area of this clade, under three different methods of analysis: Fitch Optimisation, Dispersal Vicariance Analysis and Weighted Ancestral Area Analysis. The analyses were made on phylogenies from parsimony under equally weighted characters, as well as under implied weighting. The equally weighted tree recovers most of the groupings proposed in previous studies. The strict consensus of the implied weighting trees recovers fifteen groups, but there is no agreement of the relationships between those groups. The ancestral area analyses agree in an Andean-Patagonian origin for the chiliensis clade, and are congruent with previous hypotheses and paleontological data.<br>Ainda que tenham sido feito muitos estudos filogenéticos no gênero Liolaemus, os mesmos não são apropriados para uma análise biogeográfica, porque não possuem uma amostragem taxonômica adequada. Desenvolve-se neste trabalho, uma análise biogeográfica do grupo de L. chiliensis, que se diferencia das contribuições prévias por representar a todos os membros do grupo. A análise biogeográfica consiste em reconstruir a área ancestral deste clado, utilizando três métodos diferentes: Otimização de Fitch, Análise de Dispersão-Vicariância e Áreas Ancestrais Pesadas. As análises foram realizadas em filogenias feitas com o critério de parsimônia sob pesos iguais e pesos implicados. A árvore obtida sob pesos iguais, recupera a maioria dos grupos encontrados em análises prévias. O consenso estrito das árvores de pesos implicados, recupera quinze grupos, mas não pode-se estabelecer as relações entre eles. A análise de áreas ancestrais permite postular a região Andino-Patagônica como provável área ancestral, resultado este, congruente com hipóteses prévias e com informação paleontológica