Possible indicators for low dimensional superconductivity in the quasi-1D carbide Sc3CoC4

The transition metal carbide Sc3CoC4 consists of a quasi-one-dimensional (1D) structure with [CoC4]_{\inft} polyanionic chains embedded in a scandium matrix. At ambient temperatures Sc3CoC4 displays metallic behavior. At lower temperatures, however, charge density wave formation has been observed around 143K which is followed by a structural phase transition at 72K. Below T^onset_c = 4.5K the polycrystalline sample becomes superconductive. From Hc1(0) and Hc2(0) values we could estimate the London penetration depth ({\lambda}_L ~= 9750 Angstroem) and the Ginsburg-Landau (GL) coherence length ({\xi}_GL ~= 187 Angstroem). The resulting GL-parameter ({\kappa} ~= 52) classifies Sc3CoC4 as a type II superconductor. Here we compare the puzzling superconducting features of Sc3CoC4, such as the unusual temperature dependence i) of the specific heat anomaly and ii) of the upper critical field H_c2(T) at T_c, and iii) the magnetic hysteresis curve, with various related low dimensional superconductors: e.g., the quasi-1D superconductor (SN)_x or the 2D transition-metal dichalcogenides. Our results identify Sc3CoC4 as a new candidate for a quasi-1D superconductor.Comment: 4 pages, 5 figure

Photoconductance of a submicron oxidized line in surface conductive single crystalline diamond

We report on sub-bandgap optoelectronic phenomena of hydrogen-terminated diamond patterned with a submicron oxidized line. The line acts as an energy barrier for the two-dimensional hole gas located below the hydrogenated diamond surface. A photoconductive gain of the hole conductivity across the barrier is measured for sub-bandgap illumination. The findings are consistent with photogenerated electrons being trapped in defect levels within the barrier. We discuss the spatial and energetic characteristics of the optoelectronic phenomena, as well as possible photocurrent effects

Validation of Geant4-based Radioactive Decay Simulation

Radioactive decays are of concern in a wide variety of applications using Monte-Carlo simulations. In order to properly estimate the quality of such simulations, knowledge of the accuracy of the decay simulation is required. We present a validation of the original Geant4 Radioactive Decay Module, which uses a per-decay sampling approach, and of an extended package for Geant4-based simulation of radioactive decays, which, in addition to being able to use a refactored per-decay sampling, is capable of using a statistical sampling approach. The validation is based on measurements of calibration isotope sources using a high purity Germanium (HPGe) detector; no calibration of the simulation is performed. For the considered validation experiment equivalent simulation accuracy can be achieved with per-decay and statistical sampling

Radioactive Decays in Geant4

The simulation of radioactive decays is a common task in Monte-Carlo systems such as Geant4. Usually, a system either uses an approach focusing on the simulations of every individual decay or an approach which simulates a large number of decays with a focus on correct overall statistics. The radioactive decay package presented in this work permits, for the first time, the use of both methods within the same simulation framework - Geant4. The accuracy of the statistical approach in our new package, RDM-extended, and that of the existing Geant4 per-decay implementation (original RDM), which has also been refactored, are verified against the ENSDF database. The new verified package is beneficial for a wide range of experimental scenarios, as it enables researchers to choose the most appropriate approach for their Geant4-based application

Carcinoid tumours of the lung and the ’PEPPS’ approach: evaluation of preoperative bronchoscopic tumour debulking as preparation for subsequent parenchyma-sparing surgery

BACKGROUND: Preoperative bronchoscopic tumour ablation has been suggested as a beneficial treatment for bronchopulmonary carcinoid tumours, although data regarding its effects and long-term outcome are lacking. METHODS: In our case-matched cohort study with 208 patients with bronchopulmonary carcinoid tumours we investigated the role of preoperative bronchoscopic interventions before subsequent surgery and analysed the safety of this Procedure of Endobronchial Preparation for Parenchyma-sparing Surgery (PEPPS) based on metastasis and recurrence rates as well as survival data from 1991 to 2010. The subsequent surgery was classified into parenchyma-sparing procedures and classical lobectomies, bilobectomies and pneumonectomies. Data were obtained from the tumour registry and medical reports. Outcomes were the frequency of parenchyma-sparing surgery after bronchoscopic treatment as well as rates of metastasis, recurrence and survival. RESULTS: 132 of 208 carcinoids were located centrally. Among them, 77 patients could be recanalised preoperatively. After bronchoscopic preparation, the rate of subsequent parenchyma-sparing surgery methods was higher (p=0.021). The effect was measured by the number of segments removed. The 10-year survival rate was 89% (typical carcinoids) and 68% (atypical carcinoids), respectively. After applying PEPPS, long-term survival was slightly higher (p=0.23). Metastasis and recurrence rates showed no relevant differences between the bronchoscopically treated or non-treated groups, or between the two types of surgery classes or between the PEPPS and non-PEPPS groups. CONCLUSIONS: After preoperative bronchoscopic treatment, parenchyma-sparing surgery techniques can be applied more frequently. Furthermore, we detected no negative effects after PEPPS based on metastasis, recurrence and survival rates

Action–effect anticipation in infant action control

There is increasing evidence that action effects play a crucial role in action understanding and action control not only in adults but also in infants. Most of the research in infants focused on the learning of action–effect contingencies or how action effects help infants to infer goals in other persons’ actions. In contrast, the present research aimed at demonstrating that infants control their own actions by action–effect anticipation once they know about specific action–effect relations. About 7 and 9-month olds observed an experimenter demonstrating two actions that differed regarding the action–effect assignment. Either a red-button press or a blue-button press or no button press elicited interesting acoustical and visual effects. The 9-month olds produced the effect action at first, with shorter latency and longer duration sustaining a direct impact of action–effect anticipation on action control. In 7-month olds the differences due to action–effect manipulation were less profound indicating developmental changes at this age

Sensing electric fields using single diamond spins

The ability to sensitively detect charges under ambient conditions would be a fascinating new tool benefitting a wide range of researchers across disciplines. However, most current techniques are limited to low-temperature methods like single-electron transistors (SET), single-electron electrostatic force microscopy and scanning tunnelling microscopy. Here we open up a new quantum metrology technique demonstrating precision electric field measurement using a single nitrogen-vacancy defect centre(NV) spin in diamond. An AC electric field sensitivity reaching ~ 140V/cm/\surd Hz has been achieved. This corresponds to the electric field produced by a single elementary charge located at a distance of ~ 150 nm from our spin sensor with averaging for one second. By careful analysis of the electronic structure of the defect centre, we show how an applied magnetic field influences the electric field sensing properties. By this we demonstrate that diamond defect centre spins can be switched between electric and magnetic field sensing modes and identify suitable parameter ranges for both detector schemes. By combining magnetic and electric field sensitivity, nanoscale detection and ambient operation our study opens up new frontiers in imaging and sensing applications ranging from material science to bioimaging

The inner centromere is a biomolecular condensate scaffolded by the chromosomal passenger complex.

The inner centromere is a region on every mitotic chromosome that enables specific biochemical reactions that underlie properties, such as the maintenance of cohesion, the regulation of kinetochores and the assembly of specialized chromatin, that can resist microtubule pulling forces. The chromosomal passenger complex (CPC) is abundantly localized to the inner centromeres and it is unclear whether it is involved in non-kinase activities that contribute to the generation of these unique chromatin properties. We find that the borealin subunit of the CPC drives phase separation of the CPC in vitro at concentrations that are below those found on the inner centromere. We also provide strong evidence that the CPC exists in a phase-separated state at the inner centromere. CPC phase separation is required for its inner-centromere localization and function during mitosis. We suggest that the CPC combines phase separation, kinase and histone code-reading activities to enable the formation of a chromatin body with unique biochemical activities at the inner centromere