Two-dimensional Thouless pumping of light in photonic moiré lattices

Continuous and quantized transports are profoundly different. The latter is determined by the global rather than local properties of a system, it exhibits unique topological features, and its ubiquitous nature causes its occurrence in many areas of science. Here we report the first observation of fully-two-dimensional Thouless pumping of light by bulk modes in a purpose-designed tilted moiré lattices imprinted in a photorefractive crystal. Pumping in such unconfined system occurs due to the longitudinal adiabatic and periodic modulation of the refractive index. The topological nature of this phenomenon manifests itself in the magnitude and direction of shift of the beam center-of-mass averaged over one pumping cycle. Our experimental results are supported by systematic numerical simulations in the frames of the continuous Schrödinger equation governing propagation of probe light beam in optically-induced photorefractive moiré lattice. Our system affords a powerful platform for the exploration of topological pumping in tunable commensurate and incommensurate geometries.P.W., Q.F., R.P. and F.Y. acknowledge support from the NSFC (No. 91950120), Scientific funding of Shanghai (No.9ZR1424400), and Shanghai Outstanding Academic Leaders Plan (No.20XD1402000). Y.V.K. and L.T. acknowledge support from the Severo Ochoa Excellence Programme (CEX2019-000910-S), Fundacio Privada Cellex, Fundacio Privada Mir-Puig, and CERCA/Generalitat de Catalunya. V.V.K. acknowledges financial support from the Portuguese Foundation for Science and Technology (FCT) under Contracts PTDC/FIS-OUT/3882/ 2020 and UIDB/00618/2020Peer ReviewedPostprint (published version

Increased Mast Cell Activation in Mongolian Gerbils Infected by Hepatitis E Virus

Recently, mechanism study of hepatitis E virus (HEV) infection has attracted an increasing attention because of the growing rate of the acute hepatitis caused by the virus over the world. As an important initiate in the inflammation, mast cells (MCs) play a critical role in maintaining a healthy physiology. However, the function of the MCs in the acute hepatitis caused by HEV is still unclear. In the present study, mongolian gerbils infected by HEV were used as an animal model to evaluate the role of MCs in the HEV infection. The positive ELISA and RT-PCR results showed the gerbils was successfully infected with HEV. The number of mast cell in the liver and the small intestine in the infected animals were growing higher significantly than the control group. In addition, higher expression of the tryptase and 5-HT in the liver and the intestine detected by immunohistochemical method and western blot also indicate the activation of MCs in the infection. These results suggest that MCs play an important role in the hepatitis E

Ultra-Short-Term Platform Motion Prediction Method of Large Floating Wind Turbines Based on LSTM Network

The motion prediction of large floating wind turbine platforms is the key technology to realize the control of active ballast systems and intelligent operation and maintenance monitoring. However, the complex environment of floating wind turbines makes ultra-short-term predictions that only rely on physical models and numerical simulation methods very challenging. Therefore, this paper proposes an innovative ultra-short-term prediction method for floating wind turbine platform motion based on the long-short-term memory (LSTM) neural network. Measured data have been used to verify the feasibility and uncertainty of this method in terms of surge motion. The results show that the ultra-short-term prediction method proposed in this paper can obtain a better accuracy. For example, the maximum mean square error of surge motion prediction in the 60 s under working condition is only about 1%. The ultra-short-term motion prediction of large floating wind turbines proposed in this paper provides solid technical support for future intelligent operation and maintenance of floating wind farms

Does Label Differential Privacy Prevent Label Inference Attacks?

Label differential privacy (LDP) is a popular framework for training private ML models on datasets with public features and sensitive private labels. Despite its rigorous privacy guarantee, it has been observed that in practice LDP does not preclude label inference attacks (LIAs): Models trained with LDP can be evaluated on the public training features to recover, with high accuracy, the very private labels that it was designed to protect. In this work, we argue that this phenomenon is not paradoxical and that LDP merely limits the advantage of an LIA adversary compared to predicting training labels using the Bayes classifier. At LDP $\epsilon=0$ this advantage is zero, hence the optimal attack is to predict according to the Bayes classifier and is independent of the training labels. Finally, we empirically demonstrate that our result closely captures the behavior of simulated attacks on both synthetic and real world datasets

Effect of Electrode Distances on Remediation of Eutrophic Water and Sediment by Sediment Microbial Fuel Cell Coupled Floating Beds

Efficient and sustainable technologies for cleaning of contaminated water and sediments are in urgent demand. In this study, a new type of sediment microbial fuel cell coupled floating bed (FB-SMFC) was developed to repair eutrophic water and sediment in a cleaner way. The effect of electrode spacing on the power generation capacity and the synchronous remediation of pollutants from eutrophic water and sediment were studied. When the electrode distance was 60 cm, the maximum power generation and pollutant removal effects were obtained. At the end of the experiment, the maximum output voltage was 0.4 V, and the chemical oxygen demand (CODCr, potassium dichromate method), total nitrogen (TN), and total phosphorus (TP) contents in the overlying water were 8 mg/L, 0.7 mg/L, and 0.39 mg/L. The corresponding removal rates were 88.2%, 78.8%, and 59.0%, respectively. The removal rates of organic matter and TN in the sediment were 12.8% and 86.4%, respectively, and the fixation rate of TP was 29.2%. Proteobacteria was the dominant phylum of bacteria in the sediment and anode. Many anaerobic bacteria were found in the overlying water, which facilitated denitrification. Overall, the results of this research revealed a highly efficient and reliable strategy for eutrophic water and sediment remediation, aquatic ecosystems restoration, and human health protection

Transformation of Chromium Speciation during High Hexavalent Chromium-Contaminated Soil Remediation by CPS and Biostimulation

To address the secondary pollution problem of chemical reduction and the defects of a long bioremediation period for the soil around a chromium (Cr) salt plant in China, calcium polysulfide (CPS) combined with biostimulation (adding nutrient solution with glucose and urea) was used to reduce and stabilize hexavalent chromium [Cr(VI)] in the soil. The results showed that the remediation effect of adding CPS and nutrient solution was better than that of CPS alone for Cr(VI)-contaminated soil. An amount of 2.15% CPS with the Cr(VI) concentration reduced to approximately 330.0 mg/kg was selected as the optimal reducing agent dosage. Following the addition of 11 g/kg glucose and 13 g/kg urea, the degradation rate of Cr(VI) reached over 92% after 3 days, and the water-soluble fraction decreased by 95.6% after 40 days. The stability of the Cr was significantly enhanced. The correlation and regression analyses of Cr speciation indicated that the water-soluble fraction had significant negative correlations with the iron-manganese (Fe-Mn) oxide-bound fraction and the organic matter-bound fraction. There were significant negative correlations between the exchangeable fraction and the carbonate-bound fraction as well as extremely significant positive correlations between the Fe-Mn oxide-bound fraction and the organic matter-bound fraction. It was speculated that both the Fe-Mn oxide-bound fraction and the organic matter-bound fraction were transformed from the water-soluble fraction, and the exchangeable fraction and the carbonate-bound fraction were mutually transformed. This study enables us to acquire more knowledge about the speciation transformation of Cr in soil and provides an efficient, low-cost, and low-risk technology for the remediation of high Cr(VI)-contaminated soil

Challenges and opportunities for improving the druggability of natural product: Why need drug delivery system?

Bioactive natural products (BNPs) are the marrow of medicinal plants, which are the secondary metabolites of organisms and have been the most famous drug discovery database. Bioactive natural products are famous for their enormous number and great safety in medical applications. However, BNPs are troubled by their poor druggability compared with synthesis drugs and are challenged as medicine (only a few BNPs are applied in clinical settings). In order to find a reasonable solution to improving the druggability of BNPs, this review summarizes their bioactive nature based on the enormous pharmacological research and tries to explain the reasons for the poor druggability of BNPs. And then focused on the boosting research on BNPs loaded drug delivery systems, this review further concludes the advantages of drug delivery systems on the druggability improvement of BNPs from the perspective of their bioactive nature, discusses why BNPs need drug delivery systems, and predicts the next direction

Stereodivergent Alkyne Hydrofluorination Using a Simple Practical Reagent

Vinyl fluorides play an important role in drug development as they serve as bioisosteres for peptide bonds and are found in a range of biologically active molecules. The discovery of safe, general and practical procedures to prepare vinyl fluorides remains an important goal and challenge for synthetic chemistry. Here we introduce an inexpensive and easily-handled reagent and report simple, scalable, and metal-free protocols for the regioselective and stereodivergent hydrofluorination of alkynes to access both the E and Z isomers of vinyl fluorides. These conditions were suitable for a diverse collection of alkynes, including several highly-functionalized pharmaceutical derivatives. Mechanistic and DFT studies support C–F bond formation through a vinyl cation intermediate, with the (E)- and (Z)-hydrofluorination products forming under kinetic and thermodynamic control, respectively.<br /

Transformation of Chromium Speciation during High Hexavalent Chromium-Contaminated Soil Remediation by CPS and Biostimulation

To address the secondary pollution problem of chemical reduction and the defects of a long bioremediation period for the soil around a chromium (Cr) salt plant in China, calcium polysulfide (CPS) combined with biostimulation (adding nutrient solution with glucose and urea) was used to reduce and stabilize hexavalent chromium [Cr(VI)] in the soil. The results showed that the remediation effect of adding CPS and nutrient solution was better than that of CPS alone for Cr(VI)-contaminated soil. An amount of 2.15% CPS with the Cr(VI) concentration reduced to approximately 330.0 mg/kg was selected as the optimal reducing agent dosage. Following the addition of 11 g/kg glucose and 13 g/kg urea, the degradation rate of Cr(VI) reached over 92% after 3 days, and the water-soluble fraction decreased by 95.6% after 40 days. The stability of the Cr was significantly enhanced. The correlation and regression analyses of Cr speciation indicated that the water-soluble fraction had significant negative correlations with the iron-manganese (Fe-Mn) oxide-bound fraction and the organic matter-bound fraction. There were significant negative correlations between the exchangeable fraction and the carbonate-bound fraction as well as extremely significant positive correlations between the Fe-Mn oxide-bound fraction and the organic matter-bound fraction. It was speculated that both the Fe-Mn oxide-bound fraction and the organic matter-bound fraction were transformed from the water-soluble fraction, and the exchangeable fraction and the carbonate-bound fraction were mutually transformed. This study enables us to acquire more knowledge about the speciation transformation of Cr in soil and provides an efficient, low-cost, and low-risk technology for the remediation of high Cr(VI)-contaminated soil

A peri-Xanthenoxanthene Centered Columnar-Stacking Organic Semiconductor for Efficient, Photothermally Stable Perovskite Solar Cells

Modulating the structure and property of hole-transporting organic semiconductors is of paramount importance for high-efficiency and stable perovskite solar cells (PSCs). This work reports a low-cost peri-xanthenoxanthene based small-molecule P1, which is prepared at a total yield of 82 % using a three-step synthetic route from the low-cost starting material 2-naphthol. P1 molecules stack in one-dimensional columnar arrangement characteristic of strong intermolecular pi-pi interactions, contributing to the formation of a solution-processed, semicrystalline thin-film exhibiting one order of magnitude higher hole mobility than the amorphous one based on the state-of-the art hole-transporter, 2,2-7,7-tetrakis(N,N '-di-paramethoxy-phenylamine 9,9 '-spirobifluorene (spiro-OMeTAD). PSCs employing P1 as the hole-transporting layer attain a high efficiency of 19.8 % at the standard AM 1.5 G conditions, and good long-term stability under continuous full sunlight exposure at 40 degrees C