Social Collaborative Filtering by Trust Yang, Bo; Lei, Yu; Liu, Jiming ...
IEEE transactions on pattern analysis and machine intelligence,
08/2017, Letnik:
39, Številka:
8
Journal Article
Recenzirano
Recommender systems are used to accurately and actively provide users with potentially interesting information or services. Collaborative filtering is a widely adopted approach to recommendation, but ...sparse data and cold-start users are often barriers to providing high quality recommendations. To address such issues, we propose a novel method that works to improve the performance of collaborative filtering recommendations by integrating sparse rating data given by users and sparse social trust network among these same users. This is a model-based method that adopts matrix factorization technique that maps users into low-dimensional latent feature spaces in terms of their trust relationship, and aims to more accurately reflect the users reciprocal influence on the formation of their own opinions and to learn better preferential patterns of users for high-quality recommendations. We use four large-scale datasets to show that the proposed method performs much better, especially for cold start users, than state-of-the-art recommendation algorithms for social collaborative filtering based on trust.
This study investigates the role of dynamic capabilities in the resource-based view framework, and also explores the relationships among different resources, different dynamic capabilities and firm ...performance. Employing samples of top 1000 Taiwanese companies, the findings show that dynamic capabilities can mediate the firm's valuable, rare, inimitable and non-substitutable (VRIN) resources to improve performance. On the contrary, non-VRIN resources have an insignificant mediating effect. Among three types of dynamic capabilities, dynamic learning capability most effectively mediates the influence of VRIN resources on performance. Furthermore, the important role of VRIN resources is addressed because of their direct effects on performance based on RBV, as well as their indirect effect via the mediation of dynamic capabilities.
Multidrug resistance (MDR) occurs frequently after long-term chemotherapy, resulting in refractory cancer and tumor recurrence. Therefore, combatting MDR is an important issue. Autophagy, a ...self-degradative system, universally arises during the treatment of sensitive and MDR cancer. Autophagy can be a double-edged sword for MDR tumors: it participates in the development of MDR and protects cancer cells from chemotherapeutics but can also kill MDR cancer cells in which apoptosis pathways are inactive. Autophagy induced by anticancer drugs could also activate apoptosis signaling pathways in MDR cells, facilitating MDR reversal. Therefore, research on the regulation of autophagy to combat MDR is expanding and is becoming increasingly important. We summarize advanced studies of autophagy in MDR tumors, including the variable role of autophagy in MDR cancer cells.
Reversible intercalation of potassium‐ion (K+) into graphite makes it a promising anode material for rechargeable potassium‐ion batteries (PIBs). However, the current graphite anodes in PIBs often ...suffer from poor cyclic stability with low coulombic efficiency. A stable solid electrolyte interphase (SEI) is necessary for stabilizing the large interlayer expansion during K+ insertion. Herein, a localized high‐concentration electrolyte (LHCE) is designed by adding a highly fluorinated ether into the concentrated potassium bis(fluorosulfonyl)imide/dimethoxyethane, which forms a durable SEI on the graphite surface and enables highly reversible K+ intercalation/deintercalation without solvent cointercalation. Furthermore, this LHCE shows a high ionic conductivity (13.6 mS cm−1) and excellent oxidation stability up to 5.3 V (vs K+/K), which enables compatibility with high‐voltage cathodes. The kinetics study reveals that K+ intercalation/deintercalation does not follow the same pathway. The potassiated graphite exhibits excellent depotassiation rate capability, while the formation of a low stage intercalation compound is the rate‐limiting step during potassiation.
A localized high‐concentration electrolyte is designed by adding a highly fluorinated ether into the concentrated potassium bis(fluorosulfonyl)imide/dimethoxyethane, which forms a durable potassium fluoride (KF)‐rich passivation layer on the graphite surface and enables highly reversible K+ intercalation/deintercalation without solvent cointercalation. The potassium‐ion batteries with the high‐loading graphite (≈8 mg cm−2) anode can operate over 300 cycles with negligible capacity decay.
Light‐weight and flexible supercapacitors with outstanding electrochemical performances are strongly desired in portable and wearable electronics. Here, ultralight nitrogen‐doped carbon macrotube ...(N‐CMT) sponges with 3D interconnected macroporous structures are fabricated and used as substrate to grow nickel ferrite (NiFe2O4) nanoparticles by vapor diffusion–precipitation and in situ growth. This process effectively suppresses the agglomeration of NiFe2O4, enabling good interfacial contact between N‐CMT sponges and NiFe2O4. More remarkably, the as‐synthesized NiFe2O4/N‐CMT composite sponges can be directly used as electrodes without additional processing that could cause agglomeration and reduction of active sites. Benefiting from the tubular structure and the synergetic effect of NiFe2O4 and N‐CMT, the NiFe2O4/N‐CMT‐2 exhibits a high specific capacitance of 715.4 F g−1 at a current density of 1 A g−1, and 508.3 F g−1 at 10 A g−1, with 90.9% of capacitance retention after 50 000 cycles at 1 A g−1 in an alkaline electrolyte. Furthermore, flexible supercapacitors are fabricated, yielding areal specific capacitances of 1397.4 and 1041.2 mF cm−2 at 0.5 and 8 mA cm−2, respectively. They also exhibit exceptional cycling performance with capacitance retention of 92.9% at 1 mA cm−2 after 10 000 cycles under bending. This work paves a new way to develop flexible, light‐weight, and high‐performance energy storage devices.
Ultralight and flexible supercapacitors are constructed with NiFe2O4/nitrogen‐doped carbon macrotube (N‐CMT) 3D sponges. Homogenous deposition of NiFe2O4 from vapor diffusion–precipitation on 3D N‐doped carbon sponges results in a composite material which exhibits a superior capacitance (1397.4 mF cm−2 at 0.5 mA cm−2) and cycling performance (92.9% after 10 000 cycles), confirming the emergence of flexible, light‐weight, and high performance energy storage devices.
The union-closed sets conjecture states that, in any nonempty union-closed family F of subsets of a finite set, there exists an element contained in at least a proportion 1/2 of the sets of F. Using ...an information-theoretic method, Gilmer recently showed that there exists an element contained in at least a proportion 0.01 of the sets of such F. He conjectured that their technique can be pushed to the constant 3-52 which was subsequently confirmed by several researchers including Sawin. Furthermore, Sawin also showed that Gilmer's technique can be improved to obtain a bound better than 3-52 but this new bound was not explicitly given by Sawin. This paper further improves Gilmer's technique to derive new bounds in the optimization form for the union-closed sets conjecture. These bounds include Sawin's improvement as a special case. By providing cardinality bounds on auxiliary random variables, we make Sawin's improvement computable and then evaluate it numerically, which yields a bound approximately 0.38234, slightly better than 3-52≈0.38197.
Nutritional metal ions play critical roles in many important immune processes. Hence, the effective modulation of metal ions may open up new forms of immunotherapy, termed as metalloimmunotherapy. ...Here, we demonstrate a prototype of cancer metalloimmunotherapy using cyclic dinucleotide (CDN) stimulator of interferon genes (STING) agonists and Mn
. We screened various metal ions and discovered specific metal ions augmented STING agonist activity, wherein Mn
promoted a 12- to 77-fold potentiation effect across the prevalent human STING haplotypes. Notably, Mn
coordinated with CDN STING agonists to self-assemble into a nanoparticle (CDN-Mn
particle, CMP) that effectively delivered STING agonists to immune cells. The CMP, administered either by local intratumoural or systemic intravenous injection, initiated robust anti-tumour immunity, achieving remarkable therapeutic efficacy with minute doses of STING agonists in multiple murine tumour models. Overall, the CMP offers a new platform for local and systemic cancer treatments, and this work underscores the great potential of coordination nanomedicine for metalloimmunotherapy.
Spinel ferrites are regarded as promising electrode materials for supercapacitors (SCs) in virtue of their low cost and high theoretical specific capacitances. However, bulk ferrites suffer from ...limited electrical conductivity, sluggish ion transport, and inadequate active sites. Therefore, rational structural design and composition regulation of the ferrites are approaches to overcome these limitations. Herein, a general biomimetic mineralization synthetic strategy is proposed to synthesize ferrite (XFe2O4, X = Ni, Co, Mn) quantum dot/graphene (QD/G) heterostructures. Anchoring ferrite QD on the graphene sheets not only strengthens the structural stability, but also forms the electrical conductivity network needed to boost the ion diffusion and charge transfer. The optimized NiFe2O4 QD/G heterostructure exhibits specific capacitances of 697.5 F g−1 at 1 A g−1, and exceptional cycling performance. Furthermore, the fabricated symmetrical SCs deliver energy densities of 24.4 and 17.4 Wh kg−1 at power densities of 499.3 and 4304.2 W kg−1, respectively. Density functional theory calculations indicate the combination of NiFe2O4 QD and graphene facilitates the adsorption of potassium atoms, ensuring rapid ion/charge transfer. This work enriches the application of the biomimetic mineralization synthesis and provides effective strategies for boosting ion/charge transfer, which may offer a new way to develop advanced electrodes for SCs.
A general biomimetic mineralization synthetic strategy is proposed to construct a series of spinel ferrite quantum dot/graphene (XFe2O4 QD/G) heterostructures. The biomimetic mineralization strategy can precisely tune complex architectures by slowing down the reaction kinetics. The combination of ferrite QD and graphene provides rich redox active sites and boosts the ion/charge transfer, improving their capacitive and cyclic performances.
The recent global pandemic of coronavirus disease 2019 (COVID-19) has enormously promoted the development of diagnostic technology. To control the spread of pandemic diseases and achieve rapid ...screening of the population, ensuring that patients receive timely treatment, rapid diagnosis has become the top priority in the development of clinical technology. This review article aims to summarize the current rapid nucleic acid diagnostic technologies applied to pandemic disease diagnosis, from rapid extraction and rapid amplification to rapid detection. We also discuss future prospects in the development of rapid nucleic acid diagnostic technologies.
Gene-expression deconvolution is used to quantify different types of cells in a mixed population. It provides a highly promising solution to rapidly characterize the tumor-infiltrating immune ...landscape and identify cold cancers. However, a major challenge is that gene-expression data are frequently contaminated by many outliers that decrease the estimation accuracy. Thus, it is imperative to develop a robust deconvolution method that automatically decontaminates data by reliably detecting and removing outliers. We developed a new machine learning tool, Fast And Robust DEconvolution of Expression Profiles (FARDEEP), to enumerate immune cell subsets from whole tumor tissue samples. To reduce noise in the tumor gene expression datasets, FARDEEP utilizes an adaptive least trimmed square to automatically detect and remove outliers before estimating the cell compositions. We show that FARDEEP is less susceptible to outliers and returns a better estimation of coefficients than the existing methods with both numerical simulations and real datasets. FARDEEP provides an estimate related to the absolute quantity of each immune cell subset in addition to relative percentages. Hence, FARDEEP represents a novel robust algorithm to complement the existing toolkit for the characterization of tissue-infiltrating immune cell landscape. The source code for FARDEEP is implemented in R and available for download at https://github.com/YuningHao/FARDEEP.git.
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