Zeeman energy and spin relaxation in a one-electron quantum dot

We have measured the relaxation time, T1, of the spin of a single electron confined in a semiconductor quantum dot (a proposed quantum bit). In a magnetic field, applied parallel to the two-dimensional electron gas in which the quantum dot is defined, Zeeman splitting of the orbital states is directly observed by measurements of electron transport through the dot. By applying short voltage pulses, we can populate the excited spin state with one electron and monitor relaxation of the spin. We find a lower bound on T1 of 50 microseconds at 7.5 T, only limited by our signal-to-noise ratio. A continuous measurement of the charge on the dot has no observable effect on the spin relaxation.Comment: Replaced with the version published in Phys. Rev. Let

Capacitive Spring Softening in Single-Walled Carbon Nanotube Nanoelectromechanical Resonators

We report the capacitive spring softening effect observed in single-walled carbon nanotube (SWNT) nanoelectromechanical (NEM) resonators. The nanotube resonators adopt dual-gate configuration with both bottom-gate and side-gate capable of tuning the resonance frequency through capacitive coupling. Interestingly, downward resonance frequency shifting is observed with increasing side-gate voltage, which can be attributed to the capacitive softening of spring constant. Furthermore, in-plane vibrational modes exhibit much stronger spring softening effect than out-of-plan modes. Our dual-gate design should enable the differentiation between these two types of vibrational modes, and open up new possibility for nonlinear operation of nanotube resonators.Comment: 12 pages/ 3 figure

Особенности деонтологии в сексологической практике

Описаны основные принципы врачебной этики в сексологической практике. Рассмотрены особенности взаимоотношений врача−сексолога и пациента. Подчеркивается, что выполнение врачом деонтологических принципов будет способствовать гармонизации семейно−сексуальных отношений.Basic principles of medical ethics in sexological practice are presented. The peculiarities of mutual relations of the doctor sexologist and the patient are discussed. It is emphasized that adherence of the doctor−sexologist of ethical principles will promote harmonization of family sexual relations

Redefining radiotherapy for early-stage breast cancer with single dose ablative treatment: a study protocol

Contains fulltext : 181789.pdf (publisher's version ) (Open Access

Comparing nuclear power trajectories in Germany and the UK: from ‘regimes' to ‘democracies’ in sociotechnical transitions and Discontinuities

This paper focuses on arguably the single most striking contrast in contemporary major energy politics in Europe (and even the developed world as a whole): the starkly differing civil nuclear policies of Germany and the UK. Germany is seeking entirely to phase out nuclear power by 2022. Yet the UK advocates a ‘nuclear renaissance’, promoting the most ambitious new nuclear construction programme in Western Europe.Here,this paper poses a simple yet quite fundamental question: what are the particular divergent conditions most strongly implicated in the contrasting developments in these two countries. With nuclear playing such an iconic role in historical discussions over technological continuity and transformation, answering this may assist in wider understandings of sociotechnical incumbency and discontinuity in the burgeoning field of‘sustainability transitions’. To this end, an ‘abductive’ approach is taken: deploying nine potentially relevant criteria for understanding the different directions pursued in Germany and the UK. Together constituted by 30 parameters spanning literatures related to socio-technical regimes in general as well as nuclear technology in particular, the criteria are divided into those that are ‘internal’ and ‘external’ to the ‘focal regime configuration’ of nuclear power and associated ‘challenger technologies’ like renewables. It is ‘internal’ criteria that are emphasised in conventional sociotechnical regime theory, with ‘external’ criteria relatively less well explored. Asking under each criterion whether attempted discontinuation of nuclear power would be more likely in Germany or the UK, a clear picture emerges. ‘Internal’ criteria suggest attempted nuclear discontinuation should be more likely in the UK than in Germany– the reverse of what is occurring. ‘External’ criteria are more aligned with observed dynamics –especially those relating to military nuclear commitments and broader ‘qualities of democracy’. Despite many differences of framing concerning exactly what constitutes ‘democracy’, a rich political science literature on this point is unanimous in characterising Germany more positively than the UK. Although based only on a single case,a potentially important question is nonetheless raised as to whether sociotechnical regime theory might usefully give greater attention to the general importance of various aspects of democracy in constituting conditions for significant technological discontinuities and transformations. If so, the policy implications are significant. A number of important areas are identified for future research, including the roles of diverse understandings and specific aspects of democracy and the particular relevance of military nuclear commitments– whose under-discussion in civil nuclear policy literatures raises its own questions of democratic accountability

Preface: natural deep eutectic solvents: A third liquid phase in living organisms? Discovery, theory, biology and applications

Plant science

The association of socioeconomic status on treatment strategy in patients with stage I and II breast cancer in the Netherlands

BACKGROUND: Previous studies have shown that socioeconomic status (SES) influences breast cancer therapy. However, these studies were performed in countries with unequal access to healthcare. Therefore, the aim of this study is to investigate whether SES also contributes to the likelihood of receiving a certain therapy in the Netherlands, a country with supposedly equal access to healthcare. MATERIALS AND METHODS: From the Netherlands Cancer Registry, 105,287 patients with newly diagnosed stage I or II breast cancer diagnosed between 2011 and 2018 were selected for analysis. SES was calculated from the average incomes of each postal code, which were divided into 10 deciles. Primary outcome was the effect of SES on the likelihood of undergoing surgery and secondary outcome was the effect of SES on the likelihood of the type of surgery. Both outcomes were corrected for patient, tumor, and hospital characteristics and were expressed as odds ratio (OR) with 95% confidence interval (CI). RESULTS: SES did not affect the likelihood of a breast cancer patient to undergo surgery (OR 1.00 per 10% stratum). In contrast, increased age and higher tumor stage were the most important factors determining whether patients underwent surgery. Patients with higher SES were less likely to undergo mastectomy (OR 0.98). Additionally, more recently diagnosed patients were less likely to undergo mastectomy (OR 0.93 per year) while patients with higher tumor stage were more likely to undergo mastectomy (OR 3.42). CONCLUSION: SES does not affect whether a patient undergoes surgery; however, higher SES increased the likelihood of BCT

Pumping of vibrational excitations in a Coulomb blockaded suspended carbon nanotube

Low-temperature transport spectroscopy measurements on a suspended few-hole carbon nanotube quantum dot are presented, showing a gate-dependent harmonic excitation spectrum which, strikingly, occurs in the Coulomb blockade regime. The quantized excitation energy corresponds to the scale expected for longitudinal vibrations of the nanotube. The electronic transport processes are identified as cotunnel-assisted sequential tunneling, resulting from non-equilibrium occupation of the mechanical mode. They appear only above a high-bias threshold at the scale of electronic nanotube excitations. We discuss models for the pumping process that explain the enhancement of the non-equilibrium occupation and show that it is connected to a subtle interplay between electronic and vibrational degrees of freedom

Natural deep eutectic solvents as a new extraction media for phenolic metabolites in Carthamus tinctorius

Plant science

Tailoring properties of natural deep eutectic solvents with water to facilitate their applications

Plant science