Summary
Hepatitis B virus surface antigen (HBsAg) plays an important role in maintaining the tolerance and may interfere with host innate and adaptive immune responses; therefore, novel therapeutic ...strategies to reduce HBsAg loads in patients infected with hepatitis B virus (HBV) are emerging as an attractive but challenging issue. Metformin could regulate hepatic metabolism while the latter interacts with HBV infection. We hypothesized that metformin could affect HBsAg expression and HBV replication and may work synergistically when combined with current antivirals. In our study, a notably inhibitory effect on HBsAg production, as well as a moderate inhibition in HBV replication and HBeAg expression was observed following metformin treatment. The 50% effective concentration (EC50) for extracellular HBsAg and intracellular HBsAg in HBV‐producing HepG2.2.15 cells was 2.85 mm and 2.75 mm, respectively, with a similarly selective index of about 18. When administered in combination, metformin enhanced the inhibitory effects of interferon‐α2b on HBsAg expression and HBV replication and provided a complimentary role in HBsAg expression for lamivudine (LMV). This novel action of metformin derives partially from its inhibition on multiple HBV cis‐acting elements. By the virtues of preferably hepatocyte distribution and safety profile, collectively, our results suggest that metformin would be potentially clinically helpful as an HBsAg production inhibitor.
An outstanding goal in quantum optics and scalable photonic quantum technology is to develop a source that each time emits one and only one entangled photon pair with simultaneously high entanglement ...fidelity, extraction efficiency, and photon indistinguishability. By coherent two-photon excitation of a single InGaAs quantum dot coupled to a circular Bragg grating bull's-eye cavity with a broadband high Purcell factor of up to 11.3, we generate entangled photon pairs with a state fidelity of 0.90(1), pair generation rate of 0.59(1), pair extraction efficiency of 0.62(6), and photon indistinguishability of 0.90(1) simultaneously. Our work will open up many applications in high-efficiency multiphoton experiments and solid-state quantum repeaters.
Studying tissue composition and function in non-human primates (NHPs) is crucial to understand the nature of our own species. Here we present a large-scale cell transcriptomic atlas that encompasses ...over 1 million cells from 45 tissues of the adult NHP Macaca fascicularis. This dataset provides a vast annotated resource to study a species phylogenetically close to humans. To demonstrate the utility of the atlas, we have reconstructed the cell-cell interaction networks that drive Wnt signalling across the body, mapped the distribution of receptors and co-receptors for viruses causing human infectious diseases, and intersected our data with human genetic disease orthologues to establish potential clinical associations. Our M. fascicularis cell atlas constitutes an essential reference for future studies in humans and NHPs.
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.
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.
To determine the association of gestational weight gain (GWG) or pre-pregnancy BMI with postpartum weight retention (PPWR).
Meta-analysis.
PubMed, Cochrane Controlled Trials Register, EMBASE, Science ...Citation Index Expanded, Current Contents Connects and Biosis Previews were used to search articles.
Publications that described the influence of pre-pregnancy BMI or GWG on PPWR.
Seventeen studies that satisfied the eligibility criteria were included in the analyses. Women with inadequate and excessive GWG had significantly lower mean PPWR of -2·14 kg (95 % CI -2·43, -1·85 kg) and higher PPWR of 3·21 kg (95 % CI 2·79, 3·62 kg), respectively, than women with adequate GWG. When postpartum time spans were stratified into 1-3 months, 3-6 months, 6-12 months, 12-36 months and ≥15 years, the association between inadequate GWG and PPWR faded over time and became insignificant (-1·42 kg; 95 % CI -3·08, 0·24 kg) after ≥15 years. However, PPWR in women with excess GWG exhibited a U-shaped trend; that is, a decline during the early postpartum time span (year 1) and then an increase in the following period. Meta-analysis of qualitative studies showed a significant relationship between excessive GWG and higher PPWR risk (OR=2·08; 95 % CI 1·60, 2·70). Moreover, meta-analysis of pre-pregnancy BMI on PPWR indicated that mean PPWR decreased with increasing BMI group.
These findings suggest that GWG, rather than pre-pregnancy BMI, determines the shorter- or longer-term PPWR.
By using a low temperature scanning tunneling microscope we have probed the superconducting energy gap of epitaxially grown Pb films as a function of the layer thickness in an ultrathin regime (5-18 ...ML). The layer-dependent energy gap and transition temperature (Tc) show persistent quantum oscillations down to the lowest thickness without any sign of suppression. Moreover, by comparison with the quantum-well states measured above Tc and the theoretical calculations, we found that the Tc oscillation correlates directly with the density of states oscillation at E(F) . The oscillation is manifested by the phase matching of the Fermi wavelength and the layer thickness, resulting in a bilayer periodicity modulated by a longer wavelength quantum beat.
Improving energy productivity is one of the most cost-effective ways to achieve a sustainable development target. The existing literature has shown some factors that have driven the improvement in ...China’s energy productivity. However, these studies do little to tackle the role of Chinese local officials. Political promotions can be seen as the most important career incentive for Chinese local officials. Hence, we intend to study whether energy productivity affects Chinese local officials’ promotions in this paper. The data of position changes for the 31 provincial governors during 1978‐2012 are utilized. We adopted probit models to empirically examine the correlation between provincial governors’ political promotions and energy productivity. The empirical results demonstrate that (1) energy productivity has a significantly positive impact on provincial governors’ political promotions in China, meaning that the provincial governors have the momentum to improve energy productivity; and (2) the effect of energy productivity on provincial governors’ political promotions has evolved, dynamically changing along with the transformation of the economic growth mode and the adjustment of the local officials’ promotion mechanism. The results are helpful in understanding the drivers of the improvement in China’s energy productivity and provide insightful implications for conducting energy policy in China.
•The data of position changes for China’s provincial governors during 1978–2012 are utilized.•Energy productivity has a positive impact on provincial governors’ promotion in China.•Political incentive is an important driver of the improvement in China’s energy productivity.•The correlation between energy productivity and local officials’ promotions was evolved.
One key feature that distinguishes the flowfield around vehicles flying in supersonic and hypersonic regimes is the bow shock wave ahead of forebody. The severe drag and aeroheating impacting these ...vehicles can be significantly reduced if the bow shock wave ahead of the vehicles forebodies is controlled to yield weaker system of oblique shocks. Benefits of forebody shock control include increasing flight ranges, economizing fuel consumption, reducing dead weights, and thermally protecting forebody structure and onboard equipment. Forebody shock control that has been widely studied since the early 1900s is achievable in numerous techniques that vary according to the mechanism of control. While some of these techniques have already been implemented in real systems, other techniques involve serious complications and tough trade-offs. The present paper is intended to serve as the first comprehensive survey on the field of forebody shock control devices. The objectives of the present paper are multifold. The paper categorizes the various forebody shock control devices in a physics-based manner, explains the underlying physics for each device, and surveys the key studies and state-of-the-art knowledge. The paper also addresses the existing gaps in knowledge, highlights the existing systems implementing these devices, and discusses the associated practical implementation issues and design-tradeoffs.
•Comprehensive survey of Forebody shock control devices for drag and aeroheating.•Clear and structured classification into mechanical, fluidic, energy, and hybrid devices.•Detailed discussion of associated flow physics, up-to-date knowledge, key studies, and current gaps are included.•Practical implementation issues and design trade-offs associated with each device are discussed.•Recommendations for both researchers and designers are proposed.
Knowledge of the in-situ stress field in the rock mass at depth is important to provide stress boundary conditions for underground excavation design, stability evaluation, and the optimization of ...ground support systems. In the present study, in-situ stress measurement using hydraulic fracturing method is conducted in the Beishan area in Gansu Province, China, a preferred candidate site for China's high-level radioactive waste repository. Information on the stress magnitudes and orientations in three sub-areas is obtained from 136 measurement points in nine sub-vertical boreholes at depths ranging from 30 to 700m, and the distribution characteristics of the in-situ stress field is analyzed. The pressure–time records obtained from the test intervals with pre-existing fractures are discussed according to the acoustic borehole televiewer (BHTV) images. The measurement results indicate that the regional stress field is dominated by horizontal stress within most of the measurement depth ranges. A piecewise distribution of the principal stresses reveals approximately three stress domains with increasing depth. At shallow and medium depths, the stress fields are characterized by σH>σh>σv and σH>σv>σh, respectively, where σH, σh, and σv are maximum horizontal, minimum horizontal, and vertical stresses, respectively. With further increase of depth, the maximum principal stress changes from horizontal to vertical (i.e. σv>σH>σh). Fracture impression results reveal that the maximum horizontal stress is dominantly oriented in the NNE–NEE direction, which is in agreement with the orientation of regional tectonic stress field generated from movement of the Earth's tectonic plates. In addition, it is found that the orientations of σH are affected by the geological structures significantly.
•Geological features of the Beishan area are described.•The results of the hydro-fracturing in-situ stress measurements are presented.•The distribution characteristics of the in-situ stress filed are analyzed.•The regional stress field associated with the geological evolution is discussed.
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