Boson sampling is a problem strongly believed to be intractable for classical computers, but can be naturally solved on a specialized photonic quantum simulator. Here, we implement the first ...time-bin-encoded boson sampling using a highly indistinguishable (∼94%) single-photon source based on a single quantum-dot-micropillar device. The protocol requires only one single-photon source, two detectors, and a loop-based interferometer for an arbitrary number of photons. The single-photon pulse train is time-bin encoded and deterministically injected into an electrically programmable multimode network. The observed three- and four-photon boson sampling rates are 18.8 and 0.2 Hz, respectively, which are more than 100 times faster than previous experiments based on parametric down-conversion.
Summary
Estrogen receptor (ER) in ovariectomy-induced osteoporotic fracture was reported to exhibit delayed expression. Mechanical stimulation enhanced ER-α expression in osteoporotic fracture callus ...at the tissue level. ER was also found to be required for the effectiveness of vibrational mechanical stimulation treatment in osteoporotic fracture healing.
Introduction
Estrogen receptor(ER) is involved in mechanical signal transduction in bone metabolism. Its expression was reported to be delayed in osteoporotic fracture healing. The purpose of this study was to investigate the roles played by ER during osteoporotic fracture healing enhanced with mechanical stimulation.
Methods
Ovariectomy-induced osteoporotic SD rats that received closed femoral fractures were divided into five groups, (i) SHAM, (ii) SHAM-VT, (iii) OVX, (iv) OVX-VT, and (v) OVX-VT-ICI, where VT stands for whole-body vibration treatment and ICI for ER antagonization by ICI 182,780. Callus formation and gene expression were assessed at 2, 4, and 8 weeks postfracture. In vitro osteoblastic differentiation, mineralization, and ER-α expression were assessed.
Results
The delayed ER expression was found to be enhanced by vibration treatment. Callus formation enhancement was shown by callus morphometry and micro-CT analysis. Enhancement effects by vibration were partially abolished when ER was modulated by ICI 182,780, in terms of callus formation capacity at 2–4 weeks and ER gene and protein expression at all time points. In vitro, ER expression in osteoblasts was not enhanced by VT treatment, but osteoblastic differentiation and mineralization were enhanced under estrogen-deprived condition. When osteoblastic cells were modulated by ICI 182,780, enhancement effects of VT were eliminated.
Conclusions
Vibration was able to enhance ER expression in ovariectomy-induced osteoporotic fracture healing. ER was essential in mechanical signal transduction and enhancement in callus formation effects during osteoporotic fracture healing enhanced by vibration. The enhancement of ER-α expression by mechanical stimulation was not likely to be related to the increased expression in osteoblastic cells but rather to the systemic enhancement in recruitment of ER-expressing progenitor cells through increased blood flow and neo-angiogenesis. This finding might explain the observed difference in mechanical sensitivity of osteoporotic fracture to mechanical stimulation.
Numerous studies indicate that p300 acts as a key transcriptional cofactor in vivo, at least, in part, by modulating activities of p53 by acetylation. Nevertheless, the regulation of the p53-p300 ...interplay is not completely understood. Here, we have identified the DEAD (Asp-Glu-Ala-Asp) box RNA helicase 24 (DDX24) as a novel regulator of the p300-p53 axis. We found that DDX24 interacts with p300, and this interaction leads to suppression of p300-mediated acetylation of p53. Notably, RNA interference-mediated knockdown of endogenous DDX24 significantly increases the acetylation levels of endogenous p53 in human cancer cells and subsequently promotes p53-mediated activation of its transcriptional targets such as p21 and p53 upregulated modulator of apoptosis (PUMA). In contrast, DDX24 expression inhibits the p300-p53 interaction and suppresses p300-mediated acetylation of p53. Moreover, DDX24 is overexpressed in human cancer cells and reduction of DDX24 protein levels by RNA interference induces cell cycle arrest and senescence in a p53-dependent manner. These results reveal DDX24 as an important regulator of p300 and suggest that the modulation of the p53-p300 interplay by DDX24 is critical in controlling p53 activities in human cancer cells.
Boson sampling is a well-defined task that is strongly believed to be intractable for classical computers, but can be efficiently solved by a specific quantum simulator. However, an outstanding ...problem for large-scale experimental boson sampling is the scalability. Here we report an experiment on boson sampling with photon loss, and demonstrate that boson sampling with a few photons lost can increase the sampling rate. Our experiment uses a quantum-dot-micropillar single-photon source demultiplexed into up to seven input ports of a 16×16 mode ultralow-loss photonic circuit, and we detect three-, four- and fivefold coincidence counts. We implement and validate lossy boson sampling with one and two photons lost, and obtain sampling rates of 187, 13.6, and 0.78 kHz for five-, six-, and seven-photon boson sampling with two photons lost, which is 9.4, 13.9, and 18.0 times faster than the standard boson sampling, respectively. Our experiment shows an approach to significantly enhance the sampling rate of multiphoton boson sampling.
•Gradient metal foams’ pool boiling is experimentally studied.•Adding nanoparticles deeply influence surfactant contact angle.•Nanoparticle and bubble growth affects fiber temperature.•Surfactant ...heavily changes GMF pool boiling heat transfer.
Fiber temperature, bubble growth and boiling curves for gradient metal foams (GMFs) with double layers have been experimentally investigated during pool boiling under atmospheric pressure in deionized water, surfactant solutions and surfactant-nanoliquids. The surfactants are Triton X-100 (TX-100) and polyvinyl pyrrolidone (PVP). The surfactant-nanoliquids are prepared by adding alumina nanoparticles into TX-100 or PVP solutions. GMFs are made by uniform copper foam and nickel foam. The pore densities are 20 PPI and 5PPI. The porosity is fixed as 0.98. The results show that PVP worsens GMF pool boiling heat transfer in most experimental heat flux region while TX-100 improves it in a certain heat flux region. Adding 10 nm alumina nanoparticles into TX-100 solutions increases the static contact angle on copper and nickel surfaces, while adding 10 nm alumina nanoparticles into PVP solutions decreases the static contact angle. Fiber temperature is affected by bubble growth and heat flux. Neither TX-100 nor PVP alumina-particle nanoliquid improves GMF pool boiling heat transfer.
Abstract
The next core-collapse supernova in the Milky Way or its satellites will represent a once-in-a-generation opportunity to obtain detailed information about the explosion of a star and provide ...significant scientific insight for a variety of fields because of the extreme conditions found within. Supernovae in our galaxy are not only rare on a human timescale but also happen at unscheduled times, so it is crucial to be ready and use all available instruments to capture all possible information from the event. The first indication of a potential stellar explosion will be the arrival of a bright burst of neutrinos. Its observation by multiple detectors worldwide can provide an early warning for the subsequent electromagnetic fireworks, as well as signal to other detectors with significant backgrounds so they can store their recent data. The supernova early warning system (SNEWS) has been operating as a simple coincidence between neutrino experiments in automated mode since 2005. In the current era of multi-messenger astronomy there are new opportunities for SNEWS to optimize sensitivity to science from the next galactic supernova beyond the simple early alert. This document is the product of a workshop in June 2019 towards design of SNEWS 2.0, an upgraded SNEWS with enhanced capabilities exploiting the unique advantages of prompt neutrino detection to maximize the science gained from such a valuable event.
A 12‐week feeding trial was conducted to evaluate the effects of replacing fishmeal (FM) with soybean meal (SBM), rapeseed meal (RM) and cottonseed meal (CSM) on growth, feed utilization and body ...composition of juvenile hybrid sturgeon Acipenser baerii ♀ × Acipenser schrenckii ♂ (initial body weight, 8.63 ± 0.24 g). Five isonitrogenous and isoenergetic diets were formulated as follows: a control diet (FM60) containing 600 g/kg FM and four other diets (FM45, FM30, FM15 and FM0 containing 450, 300, 150 and 0 g/kg FM, respectively) where protein from FM was substituted by a mixture of SBM, RM and CSM. Fish fed FM0 and FM15 had poorer growth performance, feed utilization, apparent digestibility coefficients of dry matter, protein, lipid and gross energy, and fed FM0 had poorer hepatosomatic index and survival compared with the fish fed FM60. The whole body lipid in fish fed FM0 was significantly higher than that in fish fed FM60 and FM15. This study indicates that 300 g/kg of FM can be replaced with a mixture of SBM, RM and CSM in the diet of juvenile hybrid sturgeon without compromising growth performance, feed utilization and body composition.
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