We probe the indistinguishability of photons emitted by a semiconductor quantum dot (QD) via time- and temperature-dependent two-photon interference (TPI) experiments. An increase in temporal ...separation between consecutive photon emission events reveals a decrease in TPI visibility on a nanosecond time scale, theoretically described by a non-Markovian noise process in agreement with fluctuating charge traps in the QD's vicinity. Phonon-induced pure dephasing results in a decrease in TPI visibility from (96±4)% at 10 K to a vanishing visibility at 40 K. In contrast to Michelson-type measurements, our experiments provide direct access to the time-dependent coherence of a quantum emitter on a nanosecond time scale.
The detection of GW170817 and its electromagnetic counterparts allows us to constrain the equation of state of dense matter in new and complementary ways. Very stiff equations of state are ruled out ...by the upper limit on the average tidal deformability, , imposed by the detected gravitational wave signal. A lower limit, , can also be extracted by considering the large amount of ejected matter that powers the kilonova AT2017gfo. By using several microscopic nucleonic equations of state, we first confirm the existence of a monotonic relation between R1.5 (the radius of the 1.5 M configuration) and . This translates the limits on into limits on the radius: 11.8 km R1.5 13.1 km. We then show that the monotonic relation is violated if a second branch of compact stars composed of quark matter exists, as in the two-families or twin-stars scenarios. In particular, it is possible to fulfill the limits on while having R1.5 significantly smaller than 12 km. In both of these scenarios, the event GW170817/AT2017gfo originates from the merger of a hadronic star and a star containing quark matter.
Neutron stars and the nuclear equation of state Burgio, G.F.; Schulze, H.-J.; Vidaña, I. ...
Progress in particle and nuclear physics,
September 2021, 2021-09-00, Letnik:
120
Journal Article
Recenzirano
Odprti dostop
We review the current status and recent progress of microscopic many-body approaches and phenomenological models, which are employed to construct the equation of state of neutron stars. The equation ...of state is relevant for the description of their structure and dynamical properties, and it rules also the dynamics of core-collapse supernovae and binary neutron star mergers. We describe neutron star matter assuming that the main degrees of freedom are nucleons and hyperons, disregarding the appearance of quark matter. We compare the theoretical predictions of the different equation-of-state models with the currently available data coming from both terrestrial laboratory experiments and recent astrophysical observations. We also analyze the importance of the nuclear strong interaction and equation of state for the cooling properties of neutron stars. We discuss the main open challenges in the description of the equation of state, mainly focusing on the limits of the different many-body techniques, the so-called “hyperon puzzle,” and the dependence of the direct URCA processes on the equation of state.
The success of advanced quantum communication relies crucially on non-classical light sources emitting single indistinguishable photons at high flux rates and purity. We report on deterministically ...fabricated microlenses with single quantum dots inside which fulfil these requirements in a flexible and robust quantum device approach. In our concept we combine cathodoluminescence spectroscopy with advanced in situ three-dimensional electron-beam lithography at cryogenic temperatures to pattern monolithic microlenses precisely aligned to pre-selected single quantum dots above a distributed Bragg reflector. We demonstrate that the resulting deterministic quantum-dot microlenses enhance the photon-extraction efficiency to (23±3)%. Furthermore we prove that such microlenses assure close to pure emission of triggered single photons with a high degree of photon indistinguishability up to (80±7)% at saturation. As a unique feature, both single-photon purity and photon indistinguishability are preserved at high excitation power and pulsed excitation, even above saturation of the quantum emitter.
Summary
Background
Basal cell carcinomas (BCCs) exhibit aberrant activation of the hedgehog pathway. Sonidegib is a hedgehog pathway inhibitor approved for the treatment of locally advanced BCC ...(laBCC) and metastatic BCC (mBCC) based on primary results of the BOLT study Basal Cell Carcinoma Outcomes with LDE225 (sonidegib) Treatment.
Objectives
This is the final 42‐month analysis of the BOLT study, evaluating the efficacy and safety of sonidegib.
Methods
Adults with no prior hedgehog pathway inhibitor therapy were randomized in a 1 : 2 ratio to sonidegib 200 mg or 800 mg once daily. Treatment continued for up to 42 months or until disease progression, unacceptable toxicity, death, study termination or withdrawal of consent. The primary efficacy end point was the objective response rate (ORR) by central review, assessed at baseline; weeks 5, 9 and 17; then subsequently every 8 or 12 weeks during years 1 or 2, respectively. Safety end points included adverse event monitoring and reporting.
Results
The study enrolled 230 patients, 79 and 151 in the 200‐mg and 800‐mg groups, respectively, of whom 8% and 3.3% remained on treatment by the 42‐month cutoff, respectively. The ORRs by central review were 56% 95% confidence interval (CI) 43–68 for laBCC and 8% (95% CI 0·2–36) for mBCC in the 200‐mg group and 46·1% (95% CI 37·2–55·1) for laBCC and 17% (95% CI 5–39) for mBCC in the 800‐mg group. No new safety concerns emerged.
Conclusions
Sonidegib demonstrated sustained efficacy and a manageable safety profile. The final BOLT results support sonidegib as a viable treatment option for laBCC and mBCC.
What's already known about this topic?
Basal cell carcinoma (BCC) is usually treatable with surgery or radiation therapy, but there are limited treatment options for patients with advanced BCC.
Sonidegib, a hedgehog pathway inhibitor approved for the treatment of advanced BCC, demonstrated clinically relevant efficacy and manageable safety in prior analyses of the phase II randomized, double‐blind BOLT study Basal Cell Carcinoma Outcomes with LDE225 (sonidegib) Treatment.
What does this study add?
This final 42‐month analysis of BOLT is the longest follow‐up available for a hedgehog pathway inhibitor.
Clinically relevant efficacy results were sustained from prior analyses, with objective response rates by central review of the approved 200‐mg daily dose of 56% in locally advanced BCC and 8% in metastatic BCC.
No new safety concerns were raised.
The results confirmed sonidegib as a viable long‐term treatment option for patients with advanced BCC.
Linked Comment: Fife. Br J Dermatol 2020; 182:1322–1323.
We investigate the use of hybrid equations of state in binary neutron-star simulations in full general relativity, where thermal effects are included in an approximate way through the adiabatic index ...Γth. We employ a newly developed finite-temperature equation of state derived in the Brueckner-Hartree-Fock approach and carry out comparisons with the corresponding hybrid versions of the same equation of state, investigating how different choices of Γth affect the gravitational-wave signal and the hydrodynamical properties of the remnant. We also perform comparisons with the widely used Steiner-Fischer-Hempel equation of state, detailing the differences between the two cases. Overall, we determine that when using a hybrid equation of state in binary neutron-star simulations, the value of the thermal adiabatic index Γth ≈ 1.7 best approximates the dynamical and thermodynamical behavior of matter computed using complete, finite-temperature equations of state.
A non-classical light source emitting pairs of identical photons represents a versatile resource of interdisciplinary importance with applications in quantum optics and quantum biology. To date, ...photon twins have mostly been generated using parametric downconversion sources, relying on Poissonian number distributions, or atoms, exhibiting low emission rates. Here we propose and experimentally demonstrate the efficient, triggered generation of photon twins using the energy-degenerate biexciton-exciton radiative cascade of a single semiconductor quantum dot. Deterministically integrated within a microlens, this nanostructure emits highly correlated photon pairs, degenerate in energy and polarization, at a rate of up to (234±4) kHz. Furthermore, we verify a significant degree of photon indistinguishability and directly observe twin-photon emission by employing photon-number-resolving detectors, which enables the reconstruction of the emitted photon number distribution. Our work represents an important step towards the realization of efficient sources of twin-photon states on a fully scalable technology platform.
Breaking fat: The regulation and mechanisms of lipophagy Schulze, Ryan J.; Sathyanarayan, Aishwarya; Mashek, Douglas G.
Biochimica et biophysica acta. Molecular and cell biology of lipids,
10/2017, Letnik:
1862, Številka:
10
Journal Article
Recenzirano
Odprti dostop
Lipophagy is defined as the autophagic degradation of intracellular lipid droplets (LDs). While the field of lipophagy research is relatively young, an expansion of research in this area over the ...past several years has greatly advanced our understanding of lipophagy. Since its original characterization in fasted liver, the contribution of lipophagy is now recognized in various organisms, cell types, metabolic states and disease models. Moreover, recent studies provide exciting new insights into the underlying mechanisms of lipophagy induction as well as the consequences of lipophagy on cell metabolism and signaling. This review summarizes recent work focusing on LDs and lipophagy as well as highlighting challenges and future directions of research as our understanding of lipophagy continues to grow and evolve. This article is part of a Special Issue entitled: Recent Advances in Lipid Droplet Biology edited by Rosalind Coleman and Matthijs Hesselink.
•Lipophagy contributes to lipid droplet (LD) degradation in numerous cell types.•Perilipins, lipases, and Rab GTPases act as key regulators of autophagic/lipophagic initiation.•Alterations in lipophagy are common in various diseases.•The mechanisms whereby autophagic machinery target LDs is poorly understood.•The downstream effects of lipophagy on cell signaling networks are largely unknown.
Summary
Background
Squamous cell carcinoma (SCC) is one of the most frequent types of cancer constituting a significant public health burden. Prevention strategies focus on limiting ultraviolet (UV) ...exposure during leisure time. However, the relative impact of occupational and nonoccupational UV exposure for SCC occurrence is unclear.
Objectives
To investigate the association between occupational and nonoccupational UV exposure for SCC in a multicentre population‐based case–control study hypothesizing that high occupational UV exposure increases the risk of SCC.
Methods
Consecutive patients with incident SCC (n = 632) were recruited from a German national dermatology network. Population‐based controls (n = 996) without history of skin cancer were recruited from corresponding residents’ registration offices and propensity score matched to cases. Lifetime UV exposure, sociodemographic and clinical characteristics were assessed by trained physicians. Occupational and nonoccupational UV exposure doses were estimated by masked investigators using established reference values. Odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were assessed using conditional logistic regression adjusting for relevant confounders.
Results
Total solar UV exposure was significantly associated with increased SCC. The OR for high (> 90th percentile) vs. low (< 40th percentile) and high vs, moderate (40–59th percentile) occupational UV exposure was 1·95 (95% CI 1·19–3·18) and 2·44 (95% CI 1·47–4·06) for SCC. Adjusting for occupational UV exposure, nonoccupational UV exposure was not significantly related to SCC incidence. Dose–response relationships were observed for occupational but not for nonoccupational solar UV exposure.
Conclusions
Solar occupational UV exposure is a major determinant of incident SCC. Our findings indicate that prevention strategies should be further expanded to the occupational setting.
What's already known about this topic?
Ultraviolet (UV) exposure is the most important risk factor for cutaneous squamous cell carcinoma (SCC).
Public health strategies mainly focus on UV‐exposure prevention in nonoccupational settings.
Epidemiological studies indicated an elevated risk of SCC in outdoor workers compared with indoor workers.
The relative impact of occupational and nonoccupational UV exposure concerning SCC risk is unclear.
What does this study add?
This population‐based case–control study was the first to apply validated UV‐exposure assessment instruments to discriminate occupational vs. nonoccupational lifetime doses.
High occupational UV exposure (> 90th percentile) is associated with a twofold increased risk for cutaneous SCC, whereas high nonoccupational UV exposure did not appear to be an independent risk factor for SCC.
Prevention strategies need to be further expanded in occupational settings to tackle the burden of SCC.
Linked Comment: von Schuckmann. Br J Dermatol 2018; 178:325–326.
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