Nanopillar spin filter tunnel junctions with manganite barriers.

The potential of a manganite ferromagnetic insulator in the field of spin-filtering has been demonstrated. For this, an ultrathin film of Sm0.75Sr0.25MnO3 is integrated as a barrier in an epitaxial oxide nanopillar tunnel junction and a high spin polarization of up to 75% at 5 K has been achieved. A large zero-bias anomaly observed in the dynamic conductance at low temperatures is explained in terms of the Kondo scattering model. In addition, a decrease in spin polarization at low bias and hysteretic magneto-resistance at low temperatures are reported. The results open up new possibilities for spin-electronics and suggest exploration of other manganites-based materials for the room temperature spin-filter applications.This work was partially supported by the ERC Advanced Integrators Grant “SUPERSPIN”. B.P. was funded by the Nehru Trust for Cambridge University and St John’s College. The TEM work at Texas A&M was supported by the U.S. National Science Foundation (NSF-DMR 0846504). The authors wish to thank Prof. J. Kumar (IIT Kanpur, India) for help in improving the manuscript.This document is the Accepted Manuscript version of a Published Work that appeared in final form in Nano Letters, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021/nl500798

Instabilities of the Vortex Lattice and the Peak Effect in Single Crystal YBa2Cu4O8

We report on the measurements of the remnant magnetization, and hence critical current, in a single crystal of YBa2Cu4O8. A peak in the temperature dependence of the critical current is observed when the external magnetic field is tilted away from the a–b planes. The observed behavior is attributed to a thermally activated instability-driven vortex-lattice splitting or vortex chain formation. The nature of the peak and the possibility of a thermally-activated dimensional crossover have been discussed

The Risk Factor and The Severity of Symptoms Relation in Women with Overactive Bladder

Aim: To investigate whether risk factors for overactive bladder (OAB) in women are associated with symptom severity and to assess the impact of symptom severity on the quality of life. Material and Method: Symptoms of 100 female patients (aged, 47.70 +/- 12.34 years) who were diagnosed with OAB were assessed using the Boyarsky symptom score (BSS). Data for age, educational status, body mass index (BMI), chronic disease, vaginal deliveries, constipation, smoking, consumption of alcohol, tea, coffee, or carbonated drinks and diets involving spicy food were recorded. Subcategories for each factor regarding quantity were established. The findings were statistically correlated with the BSS and with each urinary symptom individually. Each patient's quality-of-life (QoL) scores were correlated with the severity of each symptom and the total, obstructive and irritative BSS. Results: Urgency was related with BMI, spicy food, vaginal deliveries, menopause, and advanced age. Nocturia had a relation with menopause and advanced age. Total BSS was significantly correlated with coffee consumption. Irritative BSS was correlated with menopause and advanced age and obstructive BSS was correlated with constipation. Total and irritative BSS were both positively correlated with the QoL score. Discusion: Risk factors can affect the severity of symptoms and these factors should be considered when planning therapy

Fever and Systemic Inflammatory Response Syndrome Seen After Percutaneous Nephrolithotomy: Review of 1290 Adult Patients

Aim: Although accepted as minimally invasive, percutaneous nephrolithotomy (PCNL) still poses a significant risk of complications. Recent studies suggest that the incidence of sepsis may be higher than previously reported. The systemic inflammatory response syndrome (SIRS) seen in the subset of patients with or without bacteremia, is a life threatening complication and the purpose of this study is to give an insight to the relation between a post-operative fever episode and the risk of developing SIRS. Material and Method: Medical files of 1646 adult patients to whom a PCNL operation was performed were reviewed. A total of 1290 patients fulfilled the needed criteria and were included in the study. Study variables were recorded from the medical files for statistical analysis. Results: Stone burden had a statistically significant correlation with SIRS (p= 2 complications were seen to increase the hospitalization period (p= 120 min. was the only operative variable that had correlation with both fever and SIRS (p2 g/dl (Delta haemoglobin-Hb) and Clavian 5 complications had statistically significant correlations with fever. ASA score >= 3, operation time >120 min. Delta Hb > 2 gr/dl, stone size and Clavian 5 complications had statistically significant correlations with the development of SIRS. The incidence of a fever episode, which was seen in 181 patients (14%), to progress to SIRS, which leaded to death, was found to be 1.6%. Discussion: Postoperative fever has a low risk of progressing to a life threatening condition. But special attention should be given to patients that also have the other SIRS criteria; blood loss more than 2 g/dl and/or operation time more than 120 minutes. Although only encountered in a small subset of patients, multiple organ dysfunctions can develop leading to death

Predicting Surgical Outcome of Percutaneous Nephrolithotomy: Validation of the Guy's Stone Score and Nephrolithometric Nomogram in Terms of Success and Complications

This single institution retrospective study aims to validate the ability of Guy's stone score and the nephrolithometric nomogram to predict the success of PCNL and to assess the correlation of the scoring systems with the complications encountered. Material and Method: Medical files of 1646 adult patients to whom a PCNL operation was performed were reviewed. A total of 1325 patients fulfilled the needed criteria and were included in the study. Study variables were recorded from the medical files for statistical analysis. Results: Stone burden was the only pre-operative, operative and post-operative variable that had a statistically significant correlation both with success and also with the complications encountered (p 120 minutes, presence of a staghorn stone, intra-and post-operative blood transfusion, duration of the nephrostomy catheter, Delta Hg more than 2 gr/dl and and positive post-operative urine/blood culture were the other associated variables related to the complications encountered (p< 0.05). ROC curve analysis performed to the nephrolithometric nomogram data showed that with a cut of value of 80.5% for success, the nomogram has a sensitivity of 71% and specificity of 74% (ROC AUC= 80%). The nomogram was further analyzed for an association between the complications encountered and showed that the association is not strong enough to predict a possible complication (ROC AUC= 67%). Discussion: This study shows that the nephrolithometric nomogram has a good predictive accuracy for success (AUC= 0.80) and the Guys's stone score has a good correlation both with success and with complications (p< 0.05) and can be used for pre-operative counseling and decision making

Intercourse type of situational anejaculation or inability to ejaculate intra-vaginally: three case reports from a conservative islamic community

Anejaculation is defined as the inability to ejaculate semen despite sexual stimulation by intercourse or masturbation. It may result from organic or psychological causes and can be classified as orgasmic, anorgasmic, and situational. Situational anejaculation may be present in intercourse type. This means existence of ejaculation by masturbation, but not during sexual intercourse. Performance anxiety, hostility toward the partner, dysfunctional psychosexual development, and unconscious desire to avoid pregnancy are the possible underlying conditions. We herein report situational anejaculation in 24-, 26-, 34-year-old males who presented with inability to ejaculate intra-vaginally since they got married. All of them were the sole males in their family, had a childhood in a conservative community, and had arranged marriages. Due to the negative aspects of psychosexual counselling in rural societies, it was not possible to continue the follow-up and treatment of patients. Despite this, the authors conclude that this clinical course of situational intercourse anejaculation suggests a psychological problem in these patients

TWIP – TRIP effect in single crystalline VFeCoCrNi multi-principle element alloy

Various multi-principle element alloys exhibit superior mechanical properties across a wide range of tem- peratures including cryogenic temperatures. In most systems, the remarkable properties are attributed to deformation twinning (twinning induced plasticity). The recent VFeCoCrNi multi-principle element alloy displays a combined twinning induced plasticity effect, at room-tem perature, and phase transformation at low deformation temperatures (transformation induced plasticity). This work considers single crystalline specimens of VFeCoCrNi loaded along the [111] direction. At room-temperature, slip dominates at low strains, below 22% plastic strain, and a delayed activation of twinning is observed. At 77 K, early activation of transformation, face-center cubic to body-center cubic having { 111 } F CC // { 110 } BCC and FCC // BCC parallel relations, was revealed

Experimental assessment of the functional fatigue in biocompatible Ti67Zr19Nb11.5Sn2.5 shape memory alloy in the vicinity of drilled holes

Shape memory alloys (SMA) exhibit desirable and unique functionalities that are suitable for a plethora of applications in the automotive, aerospace, and biomedical industries. The TiNbZrSn SMA has been specifically developed for biomedical applications owing to its enhanced biocompatibility compared to the widely available and heavily investigated NiTi-based SMA. In this work, the effects of mechanical rolling, heat treatment, and grain size on the functional fatigue properties of TiNbZrSn are investigated under cyclic loading conditions. Superelasticity was observed for samples rolled to reduction levels exceeding 90 %. However, the recovery magnitudes improved significantly following 96.6 % rolling due to the optimization of the grain size. The reduction in grain size, from about 400 μm in the homogenized conditions to 50 μm for the 96.6 % rolled state, increases slip resistance which consequently promotes superelasticity. The functional superelastic properties were also evaluated for samples with geometric stress concentration (drilled hole). Using full-field measurement techniques, the applied, recoverable, irreversible strains, and their evolution under cyclic loading conditions were carefully measured. The use of virtual extensometers located in multiple locations around the geometric stress concentration provides means to not only evaluate the functional degradation of local superelastic properties, but also the transition to structural damage through the initiation and propagation of fatigue cracks