A Broad Learning Approach for Context-Aware Mobile Application Recommendation

With the rapid development of mobile apps, the availability of a large number of mobile apps in application stores brings challenge to locate appropriate apps for users. Providing accurate mobile app recommendation for users becomes an imperative task. Conventional approaches mainly focus on learning users' preferences and app features to predict the user-app ratings. However, most of them did not consider the interactions among the context information of apps. To address this issue, we propose a broad learning approach for \textbf{C}ontext-\textbf{A}ware app recommendation with \textbf{T}ensor \textbf{A}nalysis (CATA). Specifically, we utilize a tensor-based framework to effectively integrate user's preference, app category information and multi-view features to facilitate the performance of app rating prediction. The multidimensional structure is employed to capture the hidden relationships between multiple app categories with multi-view features. We develop an efficient factorization method which applies Tucker decomposition to learn the full-order interactions within multiple categories and features. Furthermore, we employ a group $\ell_{1}-$norm regularization to learn the group-wise feature importance of each view with respect to each app category. Experiments on two real-world mobile app datasets demonstrate the effectiveness of the proposed method

Evolution mechanism of principal modes in climate dynamics

Eigen analysis has been a powerful tool to distinguish multiple processes into different simple principal modes in complex systems. For a non-equilibrium system, the principal modes corresponding to the non-equilibrium processes are usually evolving with time. Here, we apply the eigen analysis into the complex climate systems. In particular, based on the daily surface air temperature in the tropics (30? S–30? N, 0? E–360? E) between 1979-01-01 and 2016-12-31, we uncover that the strength of two dominated intra-annual principal modes represented by the eigenvalues significantly changes with the El Niño/southern oscillation from year to year. Specifically, according to the ‘regional correlation’ introduced for the first intra-annual principal mode, we find that a sharp positive peak of the correlation between the El Niño region and the northern (southern) hemisphere usually signals the beginning (end) of the El Niño. We discuss the underlying physical mechanism and suppose that the evolution of the first intra-annual principal mode is related to the meridional circulations; the evolution of the second intra-annual principal mode responds positively to the Walker circulation. Our framework presented here not only facilitates the understanding of climate systems but also can potentially be used to study the dynamical evolution of other natural or engineering complex systems. © 2020 The Author(s)

Tuning the synthesis of polymetallic-doped ZIF derived materials for efficient hydrogenation of furfural to furfuryl alcohol

Cu, Co and Zn modified N-doped porous carbons (CuCo/Zn@NPC) are prepared using a polymetallic homogeneous doping and self-templating method as high performance non-noble metal catalysts for the hydrogenation of furfural (FF) to furfuryl alcohol (FAL). The CuCo/Zn@NPC-600 catalyst after treatment at 600 °C shows a superior catalytic activity with nearly 100% conversion of FF and an almost 100% selectivity of FAL using H2 at 140 °C. Meanwhile in the catalytic transfer hydrogenation (CTH) using 2-propanol as a H-donor, the conversion of FF reaches 95.8% and the selectivity of FAL is 99.1%. The results show that the Zn dopant leads to 37.3 times higher yield on the CuCo/Zn@NPC-600 catalyst than that on CuCo@NPC-600, and 2.3 times higher than that on Co/Zn@NPC-600 with Cu dopants. The efficient activity of the CuCo/Zn@NPC-600 catalyst is mainly due to the highly dispersed metal nanoparticles, the advanced porous structure resulting from Zn escape from the precursor template, and the synergistic effect between Cu and Co. Furthermore, the CuCo/Zn@NPC-600 catalyst exhibits good recyclability in FF hydrogenation in four cycle tests. The advanced synthesis method using a homogeneous doping and self-templating strategy sheds light on preparing effective catalysts for hydrogenation of biomass-based compounds

Efficient single-atom Ni for catalytic transfer hydrogenation of furfural to furfuryl alcohol

The employment of single-atom catalysts in the catalytic transfer hydrogenation (CTH) of furfural (FF) to furfuryl alcohol (FAL) have never been effectively explored. Herein, Ni single-atoms supported on nitrogen doped carbon (Ni-SAs/NC) catalyst is synthesized and first ever utilized in CTH of FF to FAL. Atomically dispersed Ni-N4 sites change the electron density at the metal center and exhibit specific adsorption and desorption to FF and FAL, promoting an outstanding catalytic performance with turnover frequency (TOF) of 832 h-1 and selectivity as high as 97.1 at 130 oC for 2 h. Such performance is 9-fold higher than that of supported Ni nanocatalysts. The Ni-SAs/NC catalyst also exhibits superior stability for CTH of FF and excellent catalytic activity for other α,β-unsaturated aldehydes. This work provides a new strategy of producing green chemical compounds using catalytic biomass conversion and suggests the future application of long-lasting single-atom catalysts for emerging sustainable technologies

MXene (Ti3C2Tx) and Carbon Nanotube Hybrid-Supported Platinum Catalysts for the High-Performance Oxygen Reduction Reaction in PEMFC

The metal–support interaction offers electronic, compositional, and geometric effects that could enhance catalytic activity and stability. Herein, a high corrosion resistance and an excellent electrical conductivity MXene (Ti3C2Tx) hybrid with a carbon nanotube (CNT) composite material is developed as a support for Pt. Such a composite catalyst enhances durability and improved oxygen reduction reaction activity compared to the commercial Pt/C catalyst. The mass activity of Pt/CNT-MXene demonstrates a 3.4-fold improvement over that of Pt/C. The electrochemical surface area of Pt/CNT–Ti3C2Tx (1:1) catalysts shows only 6% drop with respect to that in Pt/C of 27% after 2000 cycle potential sweeping. Furthermore, the Pt/CNT–Ti3C2Tx (1:1) is used as a cathode catalyst for single cell and stack, and the maximum power density of the stack reaches 138 W. The structure distortion of the Pt cluster induced by MXene is disadvantageous to the desorption of O atoms. This issue can be solved by adding CNT on MXene to stabilize the Pt cluster. These remarkable catalytic performances could be attributed to the synergistic effect between Pt and CNT–Ti3C2Tx

Systematic analysis of the necroptosis index in pan-cancer and classification in discriminating the prognosis and immunotherapy responses of 1716 glioma patients

Necroptosis is a programmed form of necrotic cell death that serves as a host gatekeeper for defense against invasion by certain pathogens. Previous studies have uncovered the essential role of necroptosis in tumor progression and implied the potential for novel therapies targeting necroptosis. However, no comprehensive analysis of multi-omics data has been conducted to better understand the relationship between necroptosis and tumor. We developed the necroptosis index (NI) to uncover the effect of necroptosis in most cancers. NI not only correlated with clinical characteristics of multiple tumors, but also could influence drug sensitivity in glioma. Based on necroptosis-related differentially expressed genes, the consensus clustering was used to classify glioma patients into two NI subgroups. Then, we revealed NI subgroup I were more sensitive to immunotherapy, particularly anti-PD1 therapy. This new NI-based classification may have prospective predictive factors for prognosis and guide physicians in prioritizing immunotherapy for potential responders

Vitamin E Analogue Improves Rabbit Sperm Quality during the Process of Cryopreservation through Its Antioxidative Action.

The process of cryopreservation results in high concentration of reactive oxygen species which is detrimental to spermatozoa. The aim of this study was to investigate whether addition of vitamin E analogue to freezing extender can facilitate the cryosurvival of spermatozoa in rabbits, and how vitamin E protects spermatozoa against damages during the process of preservation. Freshly ejaculated semen was diluted with Tris-citrate-glucose extender supplemented with different concentrations of Trolox (a vitamin E analogue). The level of radical oxygen species (ROS) in spermatozoa that was exposed to Trolox was significantly lower than that of the control during each step of the process of preservation. The percentage of frozen-thawed spermatozoa with lipid peroxidation in the Trolox treatments was significantly lower than that of the control. The motility, intact acrosome, membrane integrity and mitochondrial potentials of the frozen-thawed spermatozoa in the treatment of 200 μM Trolox were significantly higher than those of the control. These observations suggest that addition of vitamin E to a freezing extender leads to higher integrity of acrosome, plasma membrane and mitochondrial membrane potential as well as higher motility. Vitamin E protects spermatozoa through its capacity to quench ROS accumulation and lipid peroxidation during the process of preservation. Addition of Trolox is recommended to facilitate the improvement of semen preservation for the rabbit breeding industry

Plasmonic Au nanoparticles supported on both sides of TiO2 hollow spheres for maximising photocatalytic activity under visible light

A strategy of intensifying the visible light harvesting ability of anatase TiO2 hollow spheres (HSs) was developed, in which both sides of TiO2 HSs were utilised for stabilising Au nanoparticles (NPs) through the sacrificial templating method and convex surface-induced confinement. The composite structure of single Au NP yolk-TiO2 shell-Au NPs, denoted as Au@Au(TiO2, was rendered and confirmed by the transmission electron microscopy analysis. Au@Au(TiO2 showed enhanced photocatalytic activity in the degradation of methylene blue and phenol in aqueous phase under visible light surpassing that of other reference materials such as Au(TiO2 by 77% and Au@P25 by 52%, respectively, in phenol degradation