Near-unity Cooper pair splitting efficiency

The two electrons of a Cooper pair in a conventional superconductor form a singlet and therefore a maximally entangled state. Recently, it was demonstrated that the two particles can be extracted from the superconductor into two spatially separated contacts via two quantum dots (QDs) in a process called Cooper pair splitting (CPS). Competing transport processes, however, limit the efficiency of this process. Here we demonstrate efficiencies up to 90%, significantly larger than required to demonstrate interaction-dominated CPS, and on the right order to test Bell's inequality with electrons. We compare the CPS currents through both QDs, for which large apparent discrepancies are possible. The latter we explain intuitively and in a semi-classical master equation model. Large efficiencies are required to detect electron entanglement and for prospective electronics-based quantum information technologies.Comment: 4 page

Prospective multicentre study using high intensity focused ultrasound (HIFU) for the focal treatment of prostate cancer: Safety outcomes and complications

Purpose To investigate focal therapy using High Intensity Focused Ultrasound (HIFU) for the treatment of localized prostate cancer (CaP), we analyzed the safety and complications of this procedure. Methods Patients (pts) eligible for this multicenter prospective cohort study suffered from low to intermediate risk localized CaP with no prior treatment. After tumor identification on multiparametric MRI and in prostate biopsy, the lesions were treated with HIFU observing a safety margin of 8 to 10 mm. Adverse events (AE) after 30 and 90 days, as well as the required interventions were assessed and stratified for treatment localizations. Results Of the 98 men included in the study in two European centers, 35 (35.7%) experienced AEs in the first 30 days after HIFU intervention with Clavien-Dindo grade ≤ II: 15 pts (15.3%) had a postoperative urinary tract infection and 26 pts (26.5%) a urinary retention. Four pts (4.1%) underwent subsequent intervention (Clavien-Dindo grade IIIa/b). The number of late postoperative complications occurring between 30 and 90 days after intervention was low (2.0%). The highest complication rate was associated with tumors located at the anterior base (50.0%). The inclusion of the urethra in the ablation zone led to AEs in 20 out of 41 cases (48.8%) and represented a significant risk factor for complications within 30 days (odds ratio = 2.53; 95% confidence interval: 1.08–5.96; P = 0.033). Conclusions Focal therapy of CaP lesions with a robotic HIFU-probe is safe and renders an acceptable rate of minor early AEs. The inclusion of the urethra in the ablation zone leads to an increase in early complications and should be avoided whenever possible

Application of Aptamers Improves CRISPR-Based Live Imaging of Plant Telomeres

Development of live imaging techniques for providing information how chromatin is organized in living cells is pivotal to decipher the regulation of biological processes. Here, we demonstrate the improvement of a live imaging technique based on CRISPR/Cas9. In this approach, the sgRNA scaffold is fused to RNA aptamers including MS2 and PP7. When the dead Cas9 (dCas9) is co-expressed with chimeric sgRNA, the fluorescent coat protein-tagged for MS2 and PP7 aptamers (tdMCP-FP and tdPCP-FP) are recruited to the targeted sequence. Compared to previous work with dCas9:GFP, we show that the quality of telomere labeling was improved in transiently transformed Nicotiana benthamiana using aptamer-based CRISPR-imaging constructs. Labeling is influenced by the copy number of aptamers and less by the promoter types. The same constructs were not applicable for labeling of repeats in stably transformed plants and roots. The constant interaction of the RNP complex with its target DNA might interfere with cellular processes

In-vivo somatostatin-receptor expression in small cell lung cancer as a prognostic image biomarker and therapeutic target

Background: Given the dismal prognosis of small cell lung cancer (SCLC), novel therapeutic targets are urgently needed. We aimed to evaluate whether SSTR expression, as assessed by positron emission tomography (PET), can be applied as a prognostic image biomarker and determined subjects eligible for peptide receptor radionuclide therapy (PRRT). Methods: A total of 67 patients (26 females; age, 41–80 years) with advanced SCLC underwent SSTR-directed PET/computed tomography (somatostatin receptor imaging, SRI). SRI-avid tumor burden was quantified by maximum standardized uptake values (SUVmax) and tumor-to-liver ratios (T/L) of the most intense SCLC lesion. Scan findings were correlated with progression-free (PFS) and overall survival (OS). In addition, subjects eligible for SSTR-directed radioligand therapy were identified, and treatment outcome and toxicity profile were recorded. Results: On a patient basis, 36/67 (53.7%) subjects presented with mainly SSTR-positive SCLC lesions (>50% lesions positive); in 10/67 patients (14.9%), all lesions were positive. The median SUVmax was found to be 8.5, while the median T/L was 1.12. SRI-uptake was not associated with PFS or OS, respectively (SUVmax vs. PFS, ρ = 0.13 with p = 0.30 and vs. OS, ρ = 0.00 with p = 0.97; T/L vs. PFS, ρ = 0.07 with p = 0.58 and vs. OS, ρ = −0.05 with p = 0.70). PRRT was performed in 14 patients. One patient succumbed to treatment-independent infectious complications immediately after PRRT. In the remaining 13 subjects, disease control was achieved in 5/13 (38.5%) with a single patient achieving a partial response (stable disease in the remainder). In the sub-group of responding patients, PFS and OS were 357 days and 480 days, respectively. Conclusions: SSTR expression as detected by SRI is not predictive of outcome in patients with advanced SCLC. However, it might serve as a therapeutic target in selected patient

Partitioning of on-demand electron pairs

We demonstrate the high fidelity splitting of electron pairs emitted on demand from a dynamic quantum dot by an electronic beam splitter. The fidelity of pair splitting is inferred from the coincidence of arrival in two detector paths probed by a measurement of the partitioning noise. The emission characteristic of the on-demand electron source is tunable from electrons being partitioned equally and independently to electron pairs being split with a fidelity of 90%. For low beam splitter transmittance we further find evidence of pair bunching violating statistical expectations for independent fermions