Fundamental Component Modeling within Recommender Systems

The proliferation of online platforms has significantly increased the scope and complexity of recommender systems. As users engage with diverse content, products, and social groups, it is increasingly important to develop models that can capture the nuanced relationships between users, items, and their interactions. This thesis proposes a comprehensive framework for modeling the core components of recommendation: users, items, and interactions. In user modeling, two published papers explore how users’ participation in groups and social interactions reveal latent interests. I propose two novel methods: one that disentangles these interests to improve recommendation personalization, and another that captures users’ dual roles as initiators and participants in social commerce contexts. In item modeling, a published paper focuses on enhancing recommendation diversity using knowledge graphs (KGs), introducing new techniques to balance accuracy and diversity. One paper focuses on interaction modeling, aiming to optimize Click-Through Rate (CTR) prediction by capturing the dynamic interactions between users and items. All experiments are conducted on public datasets (e.g., Steam, Amazon, MovieLens) and an industrial dataset from Meta, demonstrating the effectiveness of the proposed models across different domains

Pyridazine-Based N‑Heterocyclic Carbene Complexes and Ruthenium-Catalyzed Oxidation Reaction of Alkenes

[Ru₂Cl­(L)­(CH₃CN)₄]­(PF₆)₃ (<b>1</b>, L = 3,6-bis­(<i>N</i>-(pyridylmethyl)­imidazolylidenyl)­pyridazine), [Cu₃L^a₃]­(PF₆)₃ (<b>2</b>, L^a = 3-(<i>N</i>-(pyridylmethyl)­imidazolylidenyl)-6-(<i>N</i>-(pyridylmethyl)­imidazolylonyl)­pyridazine), [Pd₂(allyl)₂L]­(PF₆)₂ (<b>3</b>), [Pd₂(allyl)₂L^b₂]­(PF₆)₂ (<b>4</b>, L^b = <i>N</i>-pyridylmethylimidazole), and [NiL^c₂]­(PF₆)₂ (<b>5</b>, L^c = 3-(<i>N</i>-(pyridylmethyl)­imidazolylidenyl)-6-methoxylpyridazine) have been synthesized and fully characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction analysis. In complex <b>1</b>, ligand L binds to two Ru­(II) centers, forming a well-behaved Ru₂(L)Cl plane with a five-membered metallocyclic ring. Complex <b>2</b> is trinuclear, containing a triangular Cu₃ unit bonded together by three 3-(<i>N</i>-(pyridylmethyl)­imidazolylidenyl)-6-(<i>N</i>-(pyridylmethyl)­imidazolylonyl)­pyridazine, where one imidazolylidene was oxidized into imidazolone. Deprotonation reaction with Ag₂O in CH₃CN and CH₃OH resulted in C–N cleavage of the imidazolium salt, and subsequent reaction with [Pd­(allyl)­Cl]₂ and Ni­(PPh₃)₂Cl₂ gave <b>4</b> and <b>5</b>, respectively. Dinuclear Ru­(II)-NHC complex <b>1</b> exhibits excellent catalytic activity for the oxidation of alkenes into diketones

Pyridazine-Based N‑Heterocyclic Carbene Complexes and Ruthenium-Catalyzed Oxidation Reaction of Alkenes

[Ru₂Cl­(L)­(CH₃CN)₄]­(PF₆)₃ (<b>1</b>, L = 3,6-bis­(<i>N</i>-(pyridylmethyl)­imidazolylidenyl)­pyridazine), [Cu₃L^a₃]­(PF₆)₃ (<b>2</b>, L^a = 3-(<i>N</i>-(pyridylmethyl)­imidazolylidenyl)-6-(<i>N</i>-(pyridylmethyl)­imidazolylonyl)­pyridazine), [Pd₂(allyl)₂L]­(PF₆)₂ (<b>3</b>), [Pd₂(allyl)₂L^b₂]­(PF₆)₂ (<b>4</b>, L^b = <i>N</i>-pyridylmethylimidazole), and [NiL^c₂]­(PF₆)₂ (<b>5</b>, L^c = 3-(<i>N</i>-(pyridylmethyl)­imidazolylidenyl)-6-methoxylpyridazine) have been synthesized and fully characterized by NMR spectroscopy, elemental analysis, and X-ray diffraction analysis. In complex <b>1</b>, ligand L binds to two Ru­(II) centers, forming a well-behaved Ru₂(L)Cl plane with a five-membered metallocyclic ring. Complex <b>2</b> is trinuclear, containing a triangular Cu₃ unit bonded together by three 3-(<i>N</i>-(pyridylmethyl)­imidazolylidenyl)-6-(<i>N</i>-(pyridylmethyl)­imidazolylonyl)­pyridazine, where one imidazolylidene was oxidized into imidazolone. Deprotonation reaction with Ag₂O in CH₃CN and CH₃OH resulted in C–N cleavage of the imidazolium salt, and subsequent reaction with [Pd­(allyl)­Cl]₂ and Ni­(PPh₃)₂Cl₂ gave <b>4</b> and <b>5</b>, respectively. Dinuclear Ru­(II)-NHC complex <b>1</b> exhibits excellent catalytic activity for the oxidation of alkenes into diketones

Quadricuspid Aortic Valve with Ruptured Sinus of Valsalva Aneurysm: a Case Report

Abstract Quadricuspid aortic valve (QAV) and sinus of Valsalva aneurysm (SVA) are rare congenital anomalies. We report an elderly patient with QAV associated with a ruptured SVA to the right atrium. Transthoracic echocardiographic and computed tomographic images are presented. We emphasize the important role of computed tomography angiography in establishing and confirming the diagnosis and facilitating treatment planning. The patient was successfully operated by a minimally invasive approach.</div

The predicted three-dimensional models of <i>U. unicinctus</i> SDO based on SDO protein in <i>A. thaliana</i> (PDB ID: 2GCU).

<p>A. The β-strands, α-helices, and loop regions are shown as yellow, red, and green ribbons, respectively. The typical β-lactamase fold and metal binding sites are labeled. B. The iron (magenta sphere) binding amino acids, H113, H169 and D188, in metal binding site I form the 2His:1Asp facial triad, the remaining residues shown are found in the metal binding site II around the iron.</p

One-Dimensional Conjugated Carbon Nitrides: Synthesis and Structure Determination by HRTEM and Solid-State NMR

Two-dimensional (2D) graphitic carbon nitrides (g-C3N4) have sparked much interest as photocatalysts. However, they suffer from high activation energy and a low separation rate of photoexcited charge carriers. Here we report a viable strategy to craft one-dimensional carbon nitrides denoted as polymelem (PM). Our PM possesses NH-bridged and the N-bridged tautomers, both of which are π-conjugated polymers based on aromatic tri-s-triazine units, as revealed by solid-state nuclear magnetic resonance (NMR), Fourier transform infrared (FTIR), and Raman techniques. A 2D 1H double-quantum–single-quantum (DQ–SQ) NMR spectrum illustrates that the 2D architecture of PM is constructed by the formation of interchain N–H···N hydrogen bonds between different 1D PM chains. PM exhibits largely improved photocatalytic efficiency compared to g-C3N4. This can be attributed to the conjugated structures of PM, which are conducive to the decrease in activation energy and separation rate of photogenerated charge carriers

Examples of positive and negative displays: Four categories.

Examples of positive and negative displays: Four categories.</p

The example of the survey.

The example of the survey.</p

Comparison of the averaged HRs of positive and negative displays (the <i>x</i>-axis indicates the time series, in which 0–15 sec is the stimulus period and 16–35 sec is the rest period; the <i>y</i>-axis indicates the magnitude of HbO).

Comparison of the averaged HRs of positive and negative displays (the x-axis indicates the time series, in which 0–15 sec is the stimulus period and 16–35 sec is the rest period; the y-axis indicates the magnitude of HbO).</p