Generation of hyperentangled states and two-dimensional quantum walks using JJ- (qq)- plates and polarization beamsplitters

A single photon can be made to entangle simultaneously in its different internal degrees of freedom (DoF) -- polarization, orbital angular momentum (OAM), and frequency -- as well as in its external DoF -- path. Such entanglement in multiple DoF is known as hyperentanglement and provide additional advantage for quantum information processing. We propose a passive optical setup using $q$-plates and polarization beamsplitters to hyperentangle an incoming single photon in polarization, OAM, and path DoF. By mapping polarization DoF to a two-dimensional coin state, and path and OAM DoF to two spatial dimensions, $x$ and $y$, we present a scheme for realization of two-dimensional discrete-time quantum walk using only polarization beamsplitters and $q$-plates ensuing the generation of hyperentangled states. The amount of hyperentanglement generated is quantified by measuring the entanglement negativity between any two DoF. We further show the hyperentanglement generation can be controlled by using an additional coin operation or by replacing the $q$-plate with a $J$-plate.Comment: A new appendix has been included, where Jones matrices are realized using $J$-plates and variable waveplate

Quantum direct communication protocol using recurrence in k-cycle quantum walk

The ability of quantum walks to evolve in a superposition of distinct quantum states has been used as a resource in quantum communication protocols. Under certain settings, the $k$-cycle discrete-time quantum walks\,(DTQW) are known to recur to its initial state after every $t_r$ steps. We first present a scheme to optically realize any $k$-cycle DTQW using $J$-plate, orbital angular momentum\,(OAM) sorters, optical switch, and optical delay line. This entangles the polarization and OAM degrees of freedom\,(DoF) of a single photon. Making use of this recurrence phenomena of $k$-cycle DTQW and the entanglement generated during the evolution, we present a new quantum direct communication protocol. The recurrence and entanglement in $k$-cycle walk are effectively used to retrieve and secure the information, respectively, in the proposed protocol. We investigate the security of the protocol against intercept and resend attack. We also quantify the effect of amplitude damping and depolarizing noises on recurrence and mutual information between polarization and OAM DoF of a single photon.Comment: 9 pages, 6 figure

AC-coupled GaAs microstrip detectors with a new type of integrated bias resistors

Full size single-sided GaAs microstrip detectors with integrated coupling capacitors and bias resistors have been fabricated on 3'' substrate wafers. PECVD deposited SiO_2 and SiO_2/Si_3N_4 layers were used to provide coupling capacitaces of 32.5 pF/cm and 61.6 pF/cm, respectively. The resistors are made of sputtered CERMET using simple lift of technique. The sheet resistivity of 78 kOhm/sq. and the thermal coefficient of resistance of less than 4x10^-3 / degree C satisfy the demands of small area biasing resistors, working on a wide temperature range.Comment: 20 pages, 9 figures, to be published in NIM

Medicinal plants used to treat Snake bite by Fulani Herdsmen in Taraba State, Nigeria

Snake bite remains a public health hazard in tropical countries. Taraba State with a high Fulani population has one of the highest incidences in the country. The Fulani herdsmen are more at risk because of their agropastoralist lifestyle. Their village settlement positions make it more difficult for them to assess antiserum, the only source of treatment available for snake bite, Therefore the only option left for them is the use of village surrounding medicinal plants for the treatment of the snake bite. Recent efforts on ethnopharmacology revealed several of these medicinal plants with potential to treat snake bite. This work was designed to document medicinal plants used by Fulani herdsmen in Taraba State, Nigeria, for the treatment of snake bites. Information provided will enable further study on the efficacy of the medicinal plants so identified. Eight out of the total sixteen Local government areas (LGAs) of Taraba State, Nigeria were selected for the survey. Sixty four (64) herdsmen with good ethnomedical knowledge were interviewed. The results showed that 19 plants species belonging to 15 plant families were used as remedies for the treatment of snake bite by 42.20% of the Fulani herdsmen interviewed. Annona senegalensis was the most frequently used plant. The proposed mechanisms of action of these plants with regards to venom enzymes inhibition or neutralization were discussed. Further studies on the efficacy and toxicity of these plants are suggested

Comparison of Magnetic Resonance Imaging and Serum Biomarkers for Detection of Human Pluripotent Stem Cell-Derived Teratomas.

The use of cells derived from pluripotent stem cells (PSCs) for regenerative therapies confers a considerable risk for neoplastic growth and teratoma formation. Preclinical and clinical assessment of such therapies will require suitable monitoring strategies to understand and mitigate these risks. Here we generated human-induced pluripotent stem cells (iPSCs), selected clones that continued to express reprogramming factors after differentiation into cardiomyocytes, and transplanted these cardiomyocytes into immunocompromised rat hearts post-myocardial infarction. We compared magnetic resonance imaging (MRI), cardiac ultrasound, and serum biomarkers for their ability to delineate teratoma formation and growth. MRI enabled the detection of teratomas with a volume >8 mm(3). A combination of three plasma biomarkers (CEA, AFP, and HCG) was able to detect teratomas with a volume >17 mm(3) and with a sensitivity of more than 87%. Based on our findings, a combination of serum biomarkers with MRI screening may offer the highest sensitivity for teratoma detection and tracking

Oxidación a 1123 K de sistemas multicapa AISI 304-Ni/Al-Al2O3/TiO2 depositados mediante proyección por llama

The oxidation behaviour of alumina/titania (97/3, 87/13 and 60/40) ceramic coatings using a Ni-Al coupling layer was studied in a thermobalance. Both layers were deposited on an AISI 304 stainless steel base metal by the flame spray technique. The coated steel was heated from room temperature to 1,123 K at 40 K min–1, oxidized in air for 50 h, and then cooled to room temperature at 40 K min–1. The mass gain was mainly attributed to the oxidation of Ni-Al coupling layer. Kinetic laws, DW·S–1 (mg.mm–2) vs. time (hours) were close to a parabolic plot for each sample. Surface composition of ceramic top layer and the cross section of multilayer system were analysed using a wide range of experimental techniques including Scanning Electron Microscopy (SEM), equipped with a link energy dispersive X-Ray spectroscopy (EDX) and X-Ray diffraction (XRD) before and after the oxidation process. Coatings 97/3 and 87/13 presented a stable structure after flame spray deposition and they did not evolve with the oxidation process, while most of the 60/40 coating changed to a metastable structure after deposition and to a more stable structure after oxidation with high micro-cracks content. SEM and EDX microanalysis of the cross-sections showed that significant oxidation and a weak intergranular precipitation had been produced in the coupling layer and on the stainless steel base metal, respectively.El comportamiento a oxidación de recubrimientos cerámicos alúmina/titania (97/3, 87/13, 60/40) usando una capa de anclaje Ni-Al se ha estudiado mediante una termobalanza. Ambas capas se han depositado sobre un acero inoxidable AISI 304 utilizando la técnica de proyección llama (FS). El acero recubierto se ha calentado desde la temperatura ambiente hasta 1.123 K a 40 K min–1, se ha oxidado al aire durante 50 h, y luego se ha enfriado hasta la temperatura ambiente a 40 K min–1. La ganancia en masa se atribuye a la oxidación de la capa de enganche Ni-Al. La cinética DW·S–1 (mg.mm–2) vs. tiempo (horas) se ha ajustado a una ley parabólica para todas las muestras. La composición super- ficial de la capa cerámica y la sección transversal del sistema multicapa se han analizado mediante las técnicas de Microscopía Electrónica de Barrido (SEM), Espectroscopia de Energías Dispersivas de Rayos X (EDX), Difracción de Rayos X (XRD) antes y después del proceso de oxidación. Los recubrimientos 97/3 y 87/13 han presentado una estruc- tura estable tras el proceso de deposición por proyección por llama y esta estructura tampoco ha evolucionado después de la oxidación, mientras la mayor parte del recubrimiento 60/40 ha cambiado a una estructura metaestable después la deposición y finalmente ha evolucionado a una estructura más estable después de la oxidación con alto contenido de microagrietamiento. El microanálisis mediante SEM y EDX de las secciones transversales han mostrado una oxidación significativa en la capa de enganche y una débil precipitación intergranular en el material base AISI 30

Prediction of Mortality in Very Premature Infants: A Systematic Review of Prediction Models

CONTEXT Being born very preterm is associated with elevated risk for neonatal mortality. The aim of this review is to give an overview of prediction models for mortality in very premature infants, assess their quality, identify important predictor variables, and provide recommendations for development of future models. METHODS Studies were included which reported the predictive performance of a model for mortality in a very preterm or very low birth weight population, and classified as development, validation, or impact studies. For each development study, we recorded the population, variables, aim, predictive performance of the model, and the number of times each model had been validated. Reporting quality criteria and minimum methodological criteria were established and assessed for development studies. RESULTS We identified 41 development studies and 18 validation studies. In addition to gestational age and birth weight, eight variables frequently predicted survival: being of average size for gestational age, female gender, non-white ethnicity, absence of serious congenital malformations, use of antenatal steroids, higher 5-minute Apgar score, normal temperature on admission, and better respiratory status. Twelve studies met our methodological criteria, three of which have been externally validated. Low reporting scores were seen in reporting of performance measures, internal and external validation, and handling of missing data. CONCLUSIONS Multivariate models can predict mortality better than birth weight or gestational age alone in very preterm infants. There are validated prediction models for classification and case-mix adjustment. Additional research is needed in validation and impact studies of existing models, and in prediction of mortality in the clinically important subgroup of infants where age and weight alone give only an equivocal prognosis.Stephanie Medlock, Anita C. J. Ravelli, Pieter Tamminga, Ben W. M. Mol, Ameen Abu-Hann

Prognostication in Acutely Admitted Older Patients by Nurses and Physicians

BACKGROUND: The process of prognostication has not been described for acutely hospitalized older patients. OBJECTIVE: To investigate (1) which factors are associated with 90-day mortality risk in a group of acutely hospitalized older medical patients, and (2) whether adding a clinical impression score of nurses or physicians improves the discriminatory ability of mortality prediction. DESIGN: Prospective cohort study. PARTICIPANTS: Four hundred and sixty-three medical patients 65 years or older acutely admitted from November 1, 2002, through July 1, 2005, to a 1024-bed tertiary university teaching hospital. MEASUREMENTS: At admission, the attending nurse and physician were asked to give a clinical impression score for the illness the patient was admitted for. This score ranged from 1 (high possibility of a good outcome) until 10 (high possibility of a bad outcome, including mortality). Of all patients baseline characteristics and clinical parameters were collected. Mortality was registered up to 90 days after admission. MAIN RESULTS: In total, 23.8% (n=110) of patients died within 90 days of admission. Four parameters were significantly associated with mortality risk: functional impairment, diagnosis malignancy, co-morbidities and high urea nitrogen serum levels. The AUC for the baseline model which included these risk factors (model 1) was 0.76 (95% CI 0.71 to 0.82). The AUC for the model using the risk factors and the clinical impression score of the physician (model 2) was 0.77 (0.71 to 0.82). The AUC for the model using the risk factors and the clinical impression score of the nurse (model 3) was 0.76 (0.71 to 0.82) and the AUC for the model, including the baseline covariates and the clinical impression score of both nurses and physicians was 0.77 (0.72 to 0.82). Adding clinical impression scores to model 1 did not significantly improve its accuracy. CONCLUSION: A set of four clinical variables predicted mortality risk in acutely hospitalized older patients quite well. Adding clinical impression scores of nurses, physicians or both did not improve the discriminating ability of the mode

PIM-1 membranes containing POSS - graphene oxide for CO2 separation

PIM-1 mixed matrix membranes (MMMs) were fabricated with polyhedral oligomeric silsesquioxane (POSS) and graphene oxide (GO) functionalized with POSS (GO-POSS), and tested for CO2/N2 (single gas) and CO2/CH4 (1:1, v:v gas mixture). The CO2 permeability of the best performing fresh MMM (containing 0.05 wt% GO-POSS) was ~ 12000 Barrer, which is 69% higher than that of the neat PIM-1 membrane, with about the same selectivity (CO2/CH4 selectivity ~ 12 and CO2/N2 selectivity ~ 20). In both cases, the gas separation data surpass the 2008 Robeson upper bound. In addition to the initial CO2 permeability enhancement, the use of GO-POSS is an efficient strategy to slow down physical aging. The MMM at a filler loading of 0.75 wt% showed less than half of the reduction in CO2 permeability than the neat PIM-1 membrane 160 days after preparation (26% for the MMM vs 58% for the purely polymeric one). © 2022 The Author(s