Cross-platform comparison of arbitrary quantum states.

As we approach the era of quantum advantage, when quantum computers (QCs) can outperform any classical computer on particular tasks, there remains the difficult challenge of how to validate their performance. While algorithmic success can be easily verified in some instances such as number factoring or oracular algorithms, these approaches only provide pass/fail information of executing specific tasks for a single QC. On the other hand, a comparison between different QCs preparing nominally the same arbitrary circuit provides an insight for generic validation: a quantum computation is only as valid as the agreement between the results produced on different QCs. Such an approach is also at the heart of evaluating metrological standards such as disparate atomic clocks. In this paper, we report a cross-platform QC comparison using randomized and correlated measurements that results in a wealth of information on the QC systems. We execute several quantum circuits on widely different physical QC platforms and analyze the cross-platform state fidelities.

Reconfigurable Topological Phases in Next-Nearest-Neighbor Coupled Resonator Lattices.

We present a reconfigurable topological photonic system consisting of a 2D lattice of coupled ring resonators, with two sublattices of site rings coupled by link rings, which can be accurately described by a tight-binding model. Unlike previous coupled-ring topological models, the design is translationally invariant, similar to the Haldane model, and the nontrivial topology is a result of next-nearest couplings with nonzero staggered phases. The system exhibits a topological phase transition between trivial and spin Chern insulator phases when the sublattices are frequency detuned. Such topological phase transitions can be easily induced by thermal or electro-optic modulators, or nonlinear cross phase modulation. We use this lattice to design reconfigurable topological waveguides, with potential applications in on-chip photon routing and switching.

Emergent equilibrium in many-body optical bistability.

Many-body systems constructed of quantum-optical building blocks can now be realized in experimental platforms ranging from exciton-polariton fluids to ultracold Rydberg gases, establishing a fascinating interface between traditional many-body physics and the driven-dissipative, nonequilibrium setting of cavity QED. At this interface, the standard techniques and intuitions of both fields are called into question, obscuring issues as fundamental as the role of fluctuations, dimensionality, and symmetry on the nature of collective behavior and phase transitions. Here, we study the driven-dissipative Bose-Hubbard model, a minimal description of numerous atomic, optical, and solid-state systems in which particle loss is countered by coherent driving. Despite being a lattice version of optical bistability, a foundational and patently nonequilibrium model of cavity QED, the steady state possesses an emergent equilibrium description in terms of a classical Ising model. We establish this picture by making new connections between traditional techniques from many-body physics (functional integrals) and quantum optics (the system-size expansion). To lowest order in a controlled expansion-organized around the experimentally relevant limit of weak interactions-the full quantum dynamics reduces to nonequilibrium Langevin equations, which support a phase transition described by model A of the Hohenberg-Halperin classification. Numerical simulations of the Langevin equations corroborate this picture, revealing that canonical behavior associated with the Ising model manifests readily in simple experimental observables.

Significance of the Extent of Intestinal Resection on the Outcome of a Short-bowel Syndrome in a Porcine Model.

AIM OF THE STUDY: Insufficient data are available to determine the most suitable extent of intestinal resection required to induce short-bowel syndrome (SBS) in pigs. This study aimed to compare the three main SBS-models published. METHODS: A 75%, 90%, or 100% mid-intestinal resection was performed in groups of n = 5 pigs each. Clinical (body weight, stool consistency) and biochemical (serum eletrolytes, citrulline, albumin, prealbumin, and transferrin) parameters were determined daily, functional (D-xylose resorption) and histological (intestinal villus length) parameters were determined after 2 weeks. A t-test and ANOVA were used for statistical analysis. RESULTS: Only in the 100% group, we observed a persistent weight loss (13.6 ± 3.8%) and diarrhea, as well as a decrease in prealbumin-levels (41%) and transferrin levels (33%). Serum electrolytes remained stable in all groups during the observation period. Citrulline stabilized at different levels (100% group 13.9 ± 1.0 µmol/L; 90% group 18.8 ± 1.0 µmol/L; 75% group 26.3 ± 1.4 µmol/L; all p < .05). D-xylose resorption was lowest in the 100%, followed by 90% and 75% group (100% group 32.8 ± 4.9 mg/L; 90% group 50.0 ± 19.6 mg/L; 75% group 57.8 ± 8.8 mg/L; p = .393). Intestinal villus length decreased in all groups (100% group 11.0%; 90% group 14.0%; 75% group 19.1%). CONCLUSIONS: 75% intestinal resection is less suitable as an SBS model, as animals tend to recover remarkably. The 90% model is suitable for longer-term studies, as animals might survive longer due to partial compensation. Due to severe nutritional, biochemical, and physiological derangements, the 100% model can only be used for acute experiments and those immediately followed by small bowel transplantation.

Nuclear accumulation of CDH1 mRNA in hepatocellular carcinoma cells.

Expression of E-cadherin has a central role in maintaining epithelial morphology. In solid tumors, reduction of E-cadherin results in disruption of intercellular contacts. Consequently, cells lose adhesive properties and gain more invasive mesenchymal properties. Nevertheless, the mechanism of E-cadherin regulation is not completely elucidated. Here we analyzed the distribution of E-cadherin expression at the cell level in human hepatocellular carcinoma, in which human liver paraffin blocks from 25 hepatocellular carcinoma patients were prepared from cancerous (CA) and noncancerous areas (NCA). In situ hybridization (ISH) was performed to detect E-cadherin and hypoxia-induced factor-1α (HIF1α) mRNAs and immunohistochemistry to stain E-cadherin protein. In parallel, RNA was extracted from CA and NCA, and E-cadherin and HIF1α were quantified by quantitative reverse transcription PCR. ISH revealed abundant E-cadherin mRNA in nuclei of hepatocellular carcinoma cells (HCCs), whereas immunohistochemistry showed depletion of E-cadherin protein from these areas. In sections of NCA, E-cadherin mRNA was also found in the cytosol, and E-cadherin protein was detected on the membrane of cells. Experiments in cell lines confirmed E-cadherin mRNA in nuclei of cells negative for E-cadherin protein. HIF1α expression is elevated in CAs, which is associated with a clear cytosolic staining for this mRNA. Our results demonstrate that E-caderhin mRNA is selectively retained in nuclei of HCCs, whereas other mRNAs are still exported, suggesting that translocation of E-cadherin mRNA from nuclei to cytoplasm has a role in regulating E-cadherin protein levels during epithelial mesenchymal transition.

Toward knowledge-based liver surgery: holistic information processing for surgical decision support.

PURPOSE: Malignant neoplasms of the liver are among the most frequent cancers worldwide. Given the diversity of options for liver cancer therapy, the choice of treatment depends on various parameters including patient condition, tumor size and location, liver function, and previous interventions. To address this issue, we present the first approach to treatment strategy planning based on holistic processing of patient-individual data, practical knowledge (i.e., case knowledge), and factual knowledge (e.g., clinical guidelines and studies). METHODS: The contributions of this paper are as follows: (1) a formalized dynamic patient model that incorporates all the heterogeneous data acquired for a specific patient in the whole course of disease treatment; (2) a concept for formalizing factual knowledge; and (3) a technical infrastructure that enables storing, accessing, and processing of heterogeneous data to support clinical decision making. RESULTS: Our patient model, which currently covers 602 patient-individual parameters, was successfully instantiated for 184 patients. It was sufficiently comprehensive to serve as the basis for the formalization of a total of 72 rules extracted from studies on patients with colorectal liver metastases or hepatocellular carcinoma. For a subset of 70 patients with these diagnoses, the system derived an average of [Formula: see text] assertions per patient. CONCLUSION: The proposed concept paves the way for holistic treatment strategy planning by enabling joint storing and processing of heterogeneous data from various information sources.

Two-dimensional lattice gauge theories with superconducting quantum circuits.

A quantum simulator of [Formula: see text] lattice gauge theories can be implemented with superconducting circuits. This allows the investigation of confined and deconfined phases in quantum link models, and of valence bond solid and spin liquid phases in quantum dimer models. Fractionalized confining strings and the real-time dynamics of quantum phase transitions are accessible as well. Here we show how state-of-the-art superconducting technology allows us to simulate these phenomena in relatively small circuit lattices. By exploiting the strong non-linear couplings between quantized excitations emerging when superconducting qubits are coupled, we show how to engineer gauge invariant Hamiltonians, including ring-exchange and four-body Ising interactions. We demonstrate that, despite decoherence and disorder effects, minimal circuit instances allow us to investigate properties such as the dynamics of electric flux strings, signaling confinement in gauge invariant field theories. The experimental realization of these models in larger superconducting circuits could address open questions beyond current computational capability.

Topologically robust transport of photons in a synthetic gauge field.

Electronic transport is localized in low-dimensional disordered media. The addition of gauge fields to disordered media leads to fundamental changes in the transport properties. We implement a synthetic gauge field for photons using silicon-on-insulator technology. By determining the distribution of transport properties, we confirm that waves are localized in the bulk and localization is suppressed in edge states. Our system provides a new platform for investigating the transport properties of photons in the presence of synthetic gauge fields.

Constrained dynamics via the Zeno effect in quantum simulation: implementing non-Abelian lattice gauge theories with cold atoms.

We show how engineered classical noise can be used to generate constrained Hamiltonian dynamics in atomic quantum simulators of many-body systems, taking advantage of the continuous Zeno effect. After discussing the general theoretical framework, we focus on applications in the context of lattice gauge theories, where imposing exotic, quasilocal constraints is usually challenging. We demonstrate the effectiveness of the scheme for both Abelian and non-Abelian gauge theories, and discuss how engineering dissipative constraints substitutes complicated, nonlocal interaction patterns by global coupling to laser fields.

Interventional real-time ultrasound imaging with an integrated electromagnetic field generator.

PURPOSE: Ultrasound (US) guided procedures are frequently performed for diagnosis and treatment of many diseases. However, there are safety and procedure duration limitations in US-guided interventions due to poor image quality and inadequate visibility of medical instruments in the field of view. To address this issue, we propose an interventional imaging system based on a mobile electromagnetic (EM) field generator (FG) attached to a US probe. METHODS: A standard US probe was integrated with an EM FG to allow combined movement of the FG with real-time imaging to achieve (1) increased tracking accuracy for medical instruments are located near the center of the tracking volume, (2) increased robustness because the FG is distant to large metallic objects, and (3) reduced setup complexity since time-consuming placement of the FG is not required. The new integrated US-FG imaging system was evaluated by assessing tracking and calibration accuracy in a clinical setting. To demonstrate clinical applicability, the prototype US-EMFG probe was tested in needle puncture procedures. RESULTS: The mobile EMFG attached to a US probe yielded sub-millimeter tracking accuracy despite the presence of metal close to the FG. Calibration errors were in the range of 1-2 mm. In an initial phantom study on US-guided needle punctures, targeting errors of about 3 mm were achieved. CONCLUSION: A combined US-EMFG probe is feasible and effective for tracking medical instruments relative to US images with high accuracy and robustness while keeping hardware complexity low.

Brain metastasis from gastrointestinal cancers: a systematic review.

BACKGROUND: Brain metastases (BM) from the gastrointestinal tract (GIT) cancers are relatively rare. Despite those advances in diagnostic and treatment options, life expectancy and quality of life in these patients are still poor. In this review, we present an overview of the studies which have been previously performed as well as a comprehensive strategy for the assessment and treatment of BM from the GIT cancers. METHOD: To obtain information on brain metastases from GIT, we performed a systematic review of Medline, EMBASE and the Cochrane Central Register of Controlled Trials (CENTRAL). The collected data included patient characteristics, primary tumor data and brain metastases data. RESULT: In our search of the literature, we found 74 studies between 1980 and 2011, which included 2538 patients with brain metastases originated from gastrointestinal cancer. Analysis of available data showed that among 2538 patients who had brain metastases from GIT, a total of 116 patients (4.57%) had esophageal cancer, 148 patients (5.83%) had gastric cancer, 233 patients (9.18%) had liver cancer, 13 patients had pancreas cancer (0.52%) and 2028 patients (79.90%) had colorectal cancer. The total median age of the patients was 58.9 years. CONCLUSION: Brain metastases have been considered the most common structural neurological complication of systemic cancer. Due to poor prognosis they influence the survival rate as well as the quality of life of the patients. The treatment of cerebral metastasis depends on the patients' situation and the decisions of the treating physicians. The early awareness of a probable metastasis from GI to the brain will have a great influence on treatment outcomes as well as the survival rate and the quality-of-life of the patients.

Prognostic impact of tumour-infiltrating immune cells on biliary tract cancer.

BACKGROUND: Biliary tract cancers (BTC) are relatively rare malignant tumours with poor prognosis. It is known from other solid neoplasms that antitumour inflammatory response has an impact on tumour behaviour and patient outcome. The aim of this study was to provide a comprehensive characterisation of antitumour inflammatory response in human BTC. METHODS: Tumour-infiltrating T lymphocytes (CD4+, CD8+, and Foxp3+), natural killer cells (perforin+), B lymphocytes (CD20+), macrophages (CD68+) as well as mast cells (CD117+) were assessed by immunohistochemistry in 375 BTC including extrahepatic (ECC; n=157), intrahepatic (ICC; n=149), and gallbladder (GBAC; n=69) adenocarcinomas. Overall and intraepithelial quantity of tumour-infiltrating immune cells was analysed. Data were correlated with clinicopathological variables and patient survival. RESULTS: The most prevalent inflammatory cell type in BTC was the T lymphocyte. Components of the adaptive immune response decreased, whereas innate immune response components increased significantly in the biliary intraepithelial neoplasia - primary carcinoma - metastasis sequence. BTC patients with intraepithelial tumour-infiltrating CD4+, CD8+, and Foxp3+ T lymphocytes showed a significantly longer overall survival. Number of total intraepithelial tumour-infiltrating Foxp3+ regulatory T lymphocytes (HR: 0.492, P=0.002) and CD4+ T lymphocytes (HR: 0.595, P=0.008) were tumour grade- and UICC-stage-independent prognosticators. The subtype-specific evaluation revealed that the tumour-infiltrating lymphocytic infiltrate is a positive outcome predictor in ECC and GBAC but not in ICC. CONCLUSION: Our findings characterise the immune response in cholangiocarcinogenesis and identify inflammatory cell types that influence the outcome of BTC patients. Further, we show that BTC subtypes show relevant differences with respect to density, quality of inflammation, and impact on patient survival.

Models of short bowel syndrome in pigs: a technical review.

BACKGROUND: Short bowel syndrome (SBS) is still a life-threatening disease in both children and adults. Although the therapeutic options are improving, challenges still remain, and to overcome these challenges is a major focus of SBS research today. In order to simulate anatomical and physiological conditions similar to those in humans for research, porcine models of SBS are often used. Various approaches for generating SBS models have been described in the literature. METHODS/RESULTS: In this work, we present a review of different types of porcine models of SBS and outline the differences between those models regarding types of animals, surgical procedures, monitoring, and methods of assessment. CONCLUSION: The aim of this study was to select the most suitable SBS model regarding the purpose of the research.

Pig kidney transplantation: an up-to-date guideline.

BACKGROUND: Swine and human beings have many aspects in common that make swine a well-characterized large animal model for kidney transplantation (KTx). However, pigs have some peculiar anatomical characteristics that standardized techniques must adapt to. The aim of this study was to prepare an up-to-date guideline for porcine KTx. METHODS: To achieve this goal, we performed a Medline search using the terminology 'kidney' or 'renal' and 'transplantation' and 'pig' or 'swine' or 'porcine'. We found over 1,300 published articles since 1963. Only 13 studies focused on the surgical aspect. Furthermore, we reviewed related books and articles about swine anatomical characteristics and surgery. Finally, our experimental experiences of KTx during the last few decades were added to this collection. RESULTS: Proper hosting, fasting, anesthesia, medical therapy and monitoring can prevent postoperative complications. Explantation with a Carrel patch of the aorta facilitates the implantation and prevents future stenosis. Native nephrectomy makes the follow-up of the implanted organ more precise. KTx in the infrarenal fossa via end-to-side anastomosis to the aorta and inferior vena cava followed by ureteroureterostomy are the recommended options for KTx in pigs compared to other possible methods. CONCLUSION: Pigs, with respect to their characterizations, constitute one of the best large animal models for KTx. Preoperative preparations are as important as the intra- and postoperative management. Using the most adaptable methods of surgery with respect to the specific anatomical characteristics of pigs can prevent undermining the studies and avoid preventable complications and pitfalls.

Current practice and future perspectives in the treatment of short bowel syndrome in children--a systematic review.

PURPOSE: Short bowel syndrome (SBS) is a malabsorption disorder of the intestine, which leads to an inadequate alimentary supply. A number of therapeutic approaches are already in use, but research advances may provide new options in the future. The purpose of this paper was to provide an overview of the established therapeutic approaches together with a discussion of the future perspectives in the treatment of patients with SBS. We review those studies dealing with the treatment of SBS patients and discuss both surgical and non-surgical approaches together with tissue engineering. METHODS: A systemic review of Medline-cited studies dealing with current practice and future perspectives in the treatment of short bowel in children was performed. RESULTS: Surgical approaches, non-surgical approaches, and tissue engineering which was used in the treatment of SBS were analyzed. Among the surgical approaches, the bowel lengthening procedures and small bowel transplantation are prevalent. Stimulants are most important concerning non-surgical approaches. Tissue engineering seems to be more experimental and was also evaluated. CONCLUSION: The treatment of SBS patients remains very complex. It is eminent to find the best therapeutic option for each patient and to individualize and modify the different possible types of applied techniques frequently.

Efficient all-optical switching using slow light within a hollow fiber.

We demonstrate a fiber-optical switch that is activated at tiny energies corresponding to a few hundred optical photons per pulse. This is achieved by simultaneously confining both photons and a small laser-cooled ensemble of atoms inside the microscopic hollow core of a single-mode photonic-crystal fiber and using quantum optical techniques for generating slow light propagation and large nonlinear interaction between light beams.

Optical bistability at low light level due to collective atomic recoil.

We demonstrate optical nonlinearities due to the interaction of weak optical fields with the collective motion of a strongly dispersive ultracold gas. The combination of a recoil-induced resonance in the high gain regime and optical waveguiding within the dispersive medium enables us to achieve a collective atomic cooperativity of 275+/-50 even in the absence of a cavity. As a result, we observe optical bistability at input powers as low as 20 pW. The present scheme allows for dynamic optical control of the dispersive properties of the ultracold gas using very weak pulses of light. The experimental observations are in good agreement with a theoretical model.

Prevalence of nicotine consumption in drug deaths.

One hundred consecutive drug death victims autopsied at the Institute of Forensic Medicine, University of Freiburg, between 1995 and 1997 were studied retrospectively as to whether the drug users had also consumed nicotine. The study included histological examination of the lung tissue for smoker cells and radioimmunological as well as GC-MS assays of the urine for cotinine, the primary metabolite of nicotine. It was found that 98 out of 100 drug victims had consumed nicotine in addition to illicit drugs or replacements. Yellowish-brown discolorations on the middle and index fingers were discernible in 44 drug victims, whereas fresh or scarred burns due to glowing cigarettes were found in six deceased drug consumers. Diseases of the bronchial system typical of heavy smokers were seen in 35 cases. Siderophages could be demonstrated in 17 of the 100 drug deaths.

The changing phenomenology of drug death over the years.

When inspecting the scene the circumstances under which a body is found and the findings on the body surface may give first clues to premortal drug abuse. Besides fresh and/or old injection marks tattoos, underweight and signs of physical neglect, especially after long-term abuse, are mentioned in literature. The incidence of such externally visible physical signs of drug abuse was systematically investigated in 100 consecutive drug deaths occurring from 1995 to 1997. Sixty-eight percent of the bodies were found in the apartments of the deceased or those of friends, 11% in public restrooms or the washrooms of restaurants. The so-called body dumping was seen in three cases. In 61% externally visible, fresh injection marks were found; on dissection of the subcutaneous veins, residues of previous injections were found in 95% of the cases. Tattoos were present in 63%. In 8% there was clear evidence of physical neglect. Eighty-six percent of the drug victims had a normal nutritional status.

Osteoclast activation in inflammatory periodontal diseases.

OBJECTIVE: In this paper, we review the mechanisms thought to be involved in the activation of osteoclasts in periodontitis. SUMMARY: Osteoclasts are regulated by both microbial and host factors. Some factors act directly on cells of the osteoclast lineage, whereas others act indirectly through other cell types in the bone environment. The proinflammatory cytokines (interleukins 1 and 6, tumor necrosis factors) have been implicated in the stimulation of osteoclastic resorption. The roles of the immunoregulatory cytoknes (interleukins 2 and 4, interferon gamma) are less clear, but decreased levels of these factors may contribute to periodontitis. A number of lipid mediators may be involved in stimulation of bone resorption. These include bacterial lipopolysaccharide and host-derived platelet-activating factor and prostaglandins. More recently, reactive oxygen intermediates and extracellular nucleotides, both present at sites of inflammation, have been investigated as possible modulators of osteoclast activity. The potential use of antiresorptive therapies in periodontitis is reviewed. CONCLUSIONS: A wide range of host and bacterial factors contribute to the loss of alveolar bone in periodontitis. However, much remains to be understood about the complex mechanisms through which these factors regulate osteoclast activity. Further studies at the cellular and molecular level will lead to a better understanding of these processes and perhaps suggest new approaches for periodontal therapy.