Statistical significance of fine structure in the frequency spectrum of Aharonov-Bohm conductance oscillations

We discuss a statistical analysis of Aharonov-Bohm conductance oscillations measured in a two-dimensional ring, in the presence of Rashba spin-orbit interaction. Measurements performed at different values of gate voltage are used to calculate the ensemble-averaged modulus of the Fourier spectrum and, at each frequency, the standard deviation associated to the average. This allows us to prove the statistical significance of a splitting that we observe in the h/e peak of the averaged spectrum. Our work illustrates in detail the role of sample specific effects on the frequency spectrum of Aharonov-Bohm conductance oscillations and it demonstrates how fine structures of a different physical origin can be discriminated from sample specific features.Comment: accepted for publication in PR

A single-step sizing and radiofrequency ablation catheter for circumferential ablation of Barrett's esophagus: Results of a pilot study

Background: The 360 Express balloon catheter (360 Express) has the ability to self-adjust to the esophageal lumen, ensuring optimal tissue contact. Objective: The objective of this article is to evaluate the efficacy and safety of the 360 Express for radiofrequency ablation (RFA) treatment of Barrett's esophagus (BE). Methods: BE patients with low-grade dysplasia (LGD), high-grade dysplasia (HGD) or early cancer (EC) were included. Visible lesions were removed by endoscopic resection (ER) prior to RFA. RFA was performed with the 360 Express using the standard ablation regimen (12J/cm2–clean–12J/cm2). Primary outcome: BE regression percentage at three months. Secondary outcomes: procedure time, adverse events, complete eradication of dysplasia (CE-D) and intestinal metaplasia (CE-IM). Results: Thirty patients (median BE C4M6) were included. Eight patients underwent ER prior to RFA. Median BE regression: 90%. Median procedure time: 31 minutes. Adverse events (13%): laceration (n = 1); atrial fibrillation (n = 1); vomiting and dysphagia (n = 1); dysregulated diabetes (n = 1). After subsequent treatment CE-D and CE-IM was achieved in 97% and 87%, respectively. In 10% a stenosis developed during additional treatment requiring a median of one dilation. Conclusion: This study shows that circumferential RFA using the 360 Express may shorten procedure time, while maintaining efficacy compared to standard circumferential RFA

Spin-dependent (magneto)transport through a ring due to spin-orbit interaction

Electron transport through a one-dimensional ring connected with two external leads, in the presence of spin-orbit interaction (SOI) of strength \alpha and a perpendicular magnetic field is studied. Applying Griffith's boundary conditions we derive analytic expressions for the reflection and transmission coefficients of the corresponding one-electron scattering problem. We generalize earlier conductance results by Nitta et al. [Appl. Phys. Lett. 75, 695 (1999)] and investigate the influence of \alpha, temperature, and a weak magnetic field on the conductance. Varying \alpha and temperature changes the position of the minima and maxima of the magnetic-field dependent conductance, and it may even convert a maximum into a minimum and vice versa.Comment: 19 pages, 9 figure

A Red-Light-Activated Ruthenium-Caged NAMPT Inhibitor Remains Phototoxic in Hypoxic Cancer Cells

Metals in Catalysis, Biomimetics & Inorganic Material

An emerging role for microglia in stress-effects on memory

Stressful experiences evoke, among others, a rapid increase in brain (nor)epinephrine (NE) levels and a slower increase in glucocorticoid hormones (GCs) in the brain. Microglia are key regulators of neuronal function and contain receptors for NE and GCs. These brain cells may therefore potentially be involved in modulating stress effects on neuronal function and learning and memory. In this review, we discuss that stress induces (1) an increase in microglial numbers as well as (2) a shift toward a pro-inflammatory profile. These microglia have (3) impaired crosstalk with neurons and (4) disrupted glutamate signaling. Moreover, microglial immune responses after stress (5) alter the kynurenine pathway through metabolites that impair glutamatergic transmission. All these effects could be involved in the impairments in memory and in synaptic plasticity caused by (prolonged) stress, implicating microglia as a potential novel target in stress-related memory impairments.Diabetes mellitus: pathophysiological changes and therap

Comparison of two intraductal brush cytology devices for suspected malignant biliary strictures: randomized controlled trial

Background: Endoscopic retrograde cholangiopancreatography (ERCP) with biliary brush cytology is commonly used to diagnose malignant pancreatobiliary strictures. This trial compared the sensitivity of two intraductal brush cytology devices. Methods: A randomized controlled trial in which consecutive patients with suspected malignant, extrahepatic biliary strictures were randomized (1:1) to a dense or conventional brush cytology device. Primary endpoint was sensitivity. Interim analysis was conducted after 50% of the patients completed follow-up. Results were interpreted by a data safety monitoring board. Results: Between June 2016 and June 2021, 64 patients were randomized to the dense (27 patients, 42%) or conventional brush (37 patients, 58%). Malignancy was diagnosed in 60 patients (94%) and benign disease in 4 patients (6%). Diagnoses were confirmed by histopathology in 34 patients (53%), cytopathology in 24 patients (38%), and clinical or radiological follow up in 6 patients (9%). Sensitivity of the dense brush was 50%, compared to 44% for the conventional brush (p = 0 center dot 785). Discussion: The results of this randomized controlled trial showed that the sensitivity of a dense brush is not superior to a conventional brush for diagnosing malignant extrahepatic pancreatobiliary strictures. This trial was prematurely ended for reasons of futility.Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Miltefosine Suppresses Inflammation in a Mouse Model of Inflammatory Bowel Disease

Cellular mechanisms in basic and clinical gastroenterology and hepatolog

Quality assessment of estrogen receptor and progesterone receptor testing in breast cancer using a tissue microarray-based approach

Assessing hormone receptor status is an essential part of the breast cancer diagnosis, as this biomarker greatly predicts response to hormonal treatment strategies. As such, hormone receptor testing laboratories are strongly encouraged to participate in external quality control schemes to achieve optimization of their immunohistochemical assays. Nine Dutch pathology departments provided tissue blocks containing invasive breast cancers which were all previously tested for estrogen receptor and/or progesterone receptor expression during routine practice. From these tissue blocks