Keyword Search in Large-Scale Databases with Topic Cluster Units

To solve the inefficiency of the existing keyword search methods in large databases, this paper proposes TCU-based query, an offline query method based on topic cluster units. First, topic cluster units (TCUs) are constructed through vertical grouping and horizontal grouping on tables and tuples. In contrast to traditional keyword query methods, this offline method cannot only reduce the query response time, but also return results comprising richer and more complete semantic information. In order to further improve the efficiency of data preprocessing, an optimized solution for table join ordering based on the genetic algorithm is presented. Second, we select index terms using the association rule, and then we build an index on every topic cluster; by doing so we can improve the query speed significantly. Finally, we conduct extensive experiments to demonstrate that our approach greatly improves the performance of keyword search

The meta-learning method for the ensemble model based on situational meta-task

IntroductionThe meta-learning methods have been widely used to solve the problem of few-shot learning. Generally, meta-learners are trained on a variety of tasks and then generalized to novel tasks.MethodsHowever, existing meta-learning methods do not consider the relationship between meta-tasks and novel tasks during the meta-training period, so that initial models of the meta-learner provide less useful meta-knowledge for the novel tasks. This leads to a weak generalization ability on novel tasks. Meanwhile, different initial models contain different meta-knowledge, which leads to certain differences in the learning effect of novel tasks during the meta-testing period. Therefore, this article puts forward a meta-optimization method based on situational meta-task construction and cooperation of multiple initial models. First, during the meta-training period, a method of constructing situational meta-task is proposed, and the selected candidate task sets provide more effective meta-knowledge for novel tasks. Then, during the meta-testing period, an ensemble model method based on meta-optimization is proposed to minimize the loss of inter-model cooperation in prediction, so that multiple models cooperation can realize the learning of novel tasks.ResultsThe above-mentioned methods are applied to popular few-shot character datasets and image recognition datasets. Furthermore, the experiment results indicate that the proposed method achieves good effects in few-shot classification tasks.DiscussionIn future work, we will extend our methods to provide more generalized and useful meta-knowledge to the model during the meta-training period when the novel few-shot tasks are completely invisible

GPT-4V(ision) as a Generalist Evaluator for Vision-Language Tasks

Automatically evaluating vision-language tasks is challenging, especially when it comes to reflecting human judgments due to limitations in accounting for fine-grained details. Although GPT-4V has shown promising results in various multi-modal tasks, leveraging GPT-4V as a generalist evaluator for these tasks has not yet been systematically explored. We comprehensively validate GPT-4V's capabilities for evaluation purposes, addressing tasks ranging from foundational image-to-text and text-to-image synthesis to high-level image-to-image translations and multi-images to text alignment. We employ two evaluation methods, single-answer grading and pairwise comparison, using GPT-4V. Notably, GPT-4V shows promising agreement with humans across various tasks and evaluation methods, demonstrating immense potential for multi-modal LLMs as evaluators. Despite limitations like restricted visual clarity grading and real-world complex reasoning, its ability to provide human-aligned scores enriched with detailed explanations is promising for universal automatic evaluator

Supplementary material for the article: Wang, L.; Zlatar, M.; Vlahović, F.; Demeshko, S.; Philouze, C.; Molton, F.; Gennari, M.; Meyer, F.; Duboc, C.; Gruden, M. Experimental and Theoretical Identification of the Origin of Magnetic Anisotropy in Intermediate Spin Iron(III) Complexes. Chemistry - A European Journal 2018, 24 (20), 5091–5094. https://doi.org/10.1002/chem.201705989

Supplementary material for: [https://doi.org/10.1002/chem.201705989]Related to published version: [http://cherry.chem.bg.ac.rs/handle/123456789/2130

Réduction catalytique du dioxygène et des protons par des complexes dinucléaires de Fe(II)

This thesis presented the design and synthesis of several bioinspired iron complexes bearing thiolate groups. Their structural, electronic, magnetic properties and their relationship also have been investigated by using different spectroscopic methods in combination with computational ones.This manuscript mainly focused on their catalytic or electrocatalytic propreties towards the reduction of O2. A non-heme diiron(II) complex with an unique thiol group has been synthesized and characterized. The thiol group can be deprotonated by base to derivate a neutral iron(II) thiolate complex. Both complexes displayed highly reactivity towards O2 to yield μ-hydroxo and μ-oxo bridged diron(III) complexes. Iron complex with thiol is an efficient ORR catalyst with 100% selectivity for H2O2 production in the presence of one-electron reducing agent and protons. When the catalysis is electrochemically-driven, H2O is the main product during electrocatalysis (~14-20% of H2O2). Based on the fact that hydrogen peroxide is generated in both cases (quantitatively or in a 20% amount in chemical and electrochemical catalysis, respectively), it can be proposed that a common intermediate, i.e. the calculated iron-peroxo complex, is generated during catalysis. The mechanism has been experimentally and theoretically investigated revealing that the control of the selectivity arises from the efficiency of the electron donor system (reducing chemical or applied potential).Another asymmetric diiron(II) complex with an FeCOCp unit has also been synthesized and well characterized in its two forms in MeCN. This asymmetric diiron (II) complex is active electrocatalyst for H2 production in an E(ECEC) mechanism with an activation step. The possible intermediates in the catalytic cycle have been generated and characterized by different spectroscopies. It should be noted that the bipyridine moiety in ligand acts as electron reservoir in the catalytic cycle.In addition, the first iron-based thiolate/disulfide interconversion system has been presented in this manuscript, which enriched the family of the metal-promoted interconversion between thiolate and disulfide. Interesingly, the iron-based system not only showed hailde-induced interconversion, but also the solvent-dependent properties.Finally, mononuclear iron(III)-thiolate complexes had interesting intermediate spin ground state. Susceptibility measurements, powder cw X- and Q-band EPR spectra, and zero-field powder Mössbauer spectra showed that all complexes display distinct magnetic anisotropy. Theoretical approach demonstrated that the main factor driving the magnetic anisotropy is the spin-orbit coupling (SOC).Cette thèse a présenté la conception et la synthèse de plusieurs complexes de fer bioinspiré portant des groupes thiolate. Leurs propriétés structurelles, électroniques, magnétiques et leur relation ont également été étudiées en utilisant différentes méthodes spectroscopiques en combinaison avec des méthodes computationnelles.Ce manuscrit portait principalement sur leurs propriétés catalytiques ou électrocatalytiques vis-à-vis de la réduction de l'O2. Un complexe non-hème diiron (II) avec un groupe thiol unique a été synthétisé et caractérisé. Le groupe thiol peut être déprotoné par une base pour dériver un complexe de thiolate de fer (II) neutre. Les deux complexes ont montré une forte réactivité vis-à-vis de l'O2 pour donner des complexes diron (III) pontés μ-hydroxo et μ-oxo. Le complexe de fer avec thiol est un catalyseur ORR efficace avec une sélectivité de 100% pour la production de H2O2 en présence d'un agent réducteur à un électron et de protons. Lorsque la catalyse est électrochimiquement entraînée, H2O est le produit principal pendant l'électrocatalyse (~ 14-20% de H2O2). Sur la base du fait que le peroxyde d'hydrogène est généré dans les deux cas (quantitativement ou en 20% en catalyse chimique et électrochimique, respectivement), on peut proposer qu'un intermédiaire commun, le complexe fer-peroxo calculé, soit généré pendant la catalyse . Le mécanisme a été étudié expérimentalement et théoriquement, révélant que le contrôle de la sélectivité provient de l'efficacité du système donneur d'électrons (réduction du potentiel chimique ou appliqué).Un autre complexe asymétrique de diiron (II) avec une unité FeCOCp a également été synthétisé et bien caractérisé dans ses deux formes dans MeCN. Ce complexe de diiron (II) asymétrique est un électrocatalyseur actif pour la production de H2 dans un mécanisme E (ECEC) avec une étape d'activation. Les intermédiaires possibles dans le cycle catalytique ont été générés et caractérisés par différentes spectroscopies. Il convient de noter que le fragment bipyridine dans le ligand agit comme un réservoir d'électrons dans le cycle catalytique.De plus, le premier système d'interconversion thiolate / disulfure à base de fer a été présenté dans ce manuscrit, qui a enrichi la famille de l'interconversion favorisée par le métal entre le thiolate et le disulfure. Intéressant, le système à base de fer a montré non seulement l'interconversion induite par l'hailde, mais aussi les propriétés dépendantes du solvant.Enfin, les complexes mononucléaires de fer (III) -thiolate présentaient un état fondamental de spin intermédiaire intéressant. Les mesures de susceptibilité, les spectres RPE de la poudre cw X et QR et les spectres de Mössbauer en poudre à champ nul ont montré que tous les complexes présentaient une anisotropie magnétique distincte. L'approche théorique a démontré que le principal facteur responsable de l'anisotropie magnétique est le couplage spin-orbite (SOC)

Catalytic reduction of dioxygen and protons by dinuclear Fe (II) complexes

Cette thèse a présenté la conception et la synthèse de plusieurs complexes de fer bioinspiré portant des groupes thiolate. Leurs propriétés structurelles, électroniques, magnétiques et leur relation ont également été étudiées en utilisant différentes méthodes spectroscopiques en combinaison avec des méthodes computationnelles.Ce manuscrit portait principalement sur leurs propriétés catalytiques ou électrocatalytiques vis-à-vis de la réduction de l'O2. Un complexe non-hème diiron (II) avec un groupe thiol unique a été synthétisé et caractérisé. Le groupe thiol peut être déprotoné par une base pour dériver un complexe de thiolate de fer (II) neutre. Les deux complexes ont montré une forte réactivité vis-à-vis de l'O2 pour donner des complexes diron (III) pontés μ-hydroxo et μ-oxo. Le complexe de fer avec thiol est un catalyseur ORR efficace avec une sélectivité de 100% pour la production de H2O2 en présence d'un agent réducteur à un électron et de protons. Lorsque la catalyse est électrochimiquement entraînée, H2O est le produit principal pendant l'électrocatalyse (~ 14-20% de H2O2). Sur la base du fait que le peroxyde d'hydrogène est généré dans les deux cas (quantitativement ou en 20% en catalyse chimique et électrochimique, respectivement), on peut proposer qu'un intermédiaire commun, le complexe fer-peroxo calculé, soit généré pendant la catalyse . Le mécanisme a été étudié expérimentalement et théoriquement, révélant que le contrôle de la sélectivité provient de l'efficacité du système donneur d'électrons (réduction du potentiel chimique ou appliqué).Un autre complexe asymétrique de diiron (II) avec une unité FeCOCp a également été synthétisé et bien caractérisé dans ses deux formes dans MeCN. Ce complexe de diiron (II) asymétrique est un électrocatalyseur actif pour la production de H2 dans un mécanisme E (ECEC) avec une étape d'activation. Les intermédiaires possibles dans le cycle catalytique ont été générés et caractérisés par différentes spectroscopies. Il convient de noter que le fragment bipyridine dans le ligand agit comme un réservoir d'électrons dans le cycle catalytique.De plus, le premier système d'interconversion thiolate / disulfure à base de fer a été présenté dans ce manuscrit, qui a enrichi la famille de l'interconversion favorisée par le métal entre le thiolate et le disulfure. Intéressant, le système à base de fer a montré non seulement l'interconversion induite par l'hailde, mais aussi les propriétés dépendantes du solvant.Enfin, les complexes mononucléaires de fer (III) -thiolate présentaient un état fondamental de spin intermédiaire intéressant. Les mesures de susceptibilité, les spectres RPE de la poudre cw X et QR et les spectres de Mössbauer en poudre à champ nul ont montré que tous les complexes présentaient une anisotropie magnétique distincte. L'approche théorique a démontré que le principal facteur responsable de l'anisotropie magnétique est le couplage spin-orbite (SOC).This thesis presented the design and synthesis of several bioinspired iron complexes bearing thiolate groups. Their structural, electronic, magnetic properties and their relationship also have been investigated by using different spectroscopic methods in combination with computational ones.This manuscript mainly focused on their catalytic or electrocatalytic propreties towards the reduction of O2. A non-heme diiron(II) complex with an unique thiol group has been synthesized and characterized. The thiol group can be deprotonated by base to derivate a neutral iron(II) thiolate complex. Both complexes displayed highly reactivity towards O2 to yield μ-hydroxo and μ-oxo bridged diron(III) complexes. Iron complex with thiol is an efficient ORR catalyst with 100% selectivity for H2O2 production in the presence of one-electron reducing agent and protons. When the catalysis is electrochemically-driven, H2O is the main product during electrocatalysis (~14-20% of H2O2). Based on the fact that hydrogen peroxide is generated in both cases (quantitatively or in a 20% amount in chemical and electrochemical catalysis, respectively), it can be proposed that a common intermediate, i.e. the calculated iron-peroxo complex, is generated during catalysis. The mechanism has been experimentally and theoretically investigated revealing that the control of the selectivity arises from the efficiency of the electron donor system (reducing chemical or applied potential).Another asymmetric diiron(II) complex with an FeCOCp unit has also been synthesized and well characterized in its two forms in MeCN. This asymmetric diiron (II) complex is active electrocatalyst for H2 production in an E(ECEC) mechanism with an activation step. The possible intermediates in the catalytic cycle have been generated and characterized by different spectroscopies. It should be noted that the bipyridine moiety in ligand acts as electron reservoir in the catalytic cycle.In addition, the first iron-based thiolate/disulfide interconversion system has been presented in this manuscript, which enriched the family of the metal-promoted interconversion between thiolate and disulfide. Interesingly, the iron-based system not only showed hailde-induced interconversion, but also the solvent-dependent properties.Finally, mononuclear iron(III)-thiolate complexes had interesting intermediate spin ground state. Susceptibility measurements, powder cw X- and Q-band EPR spectra, and zero-field powder Mössbauer spectra showed that all complexes display distinct magnetic anisotropy. Theoretical approach demonstrated that the main factor driving the magnetic anisotropy is the spin-orbit coupling (SOC)

Keyword Query Expansion Paradigm Based on Recommendation and Interpretation in Relational Databases

Due to the ambiguity and impreciseness of keyword query in relational databases, the research on keyword query expansion has attracted wide attention. Existing query expansion methods expose users’ query intention to a certain extent, but most of them cannot balance the precision and recall. To address this problem, a novel two-step query expansion approach is proposed based on query recommendation and query interpretation. First, a probabilistic recommendation algorithm is put forward by constructing a term similarity matrix and Viterbi model. Second, by using the translation algorithm of triples and construction algorithm of query subgraphs, query keywords are translated to query subgraphs with structural and semantic information. Finally, experimental results on a real-world dataset demonstrate the effectiveness and rationality of the proposed method

Fast Submodular Function Maximization

Submodular functions have many real-world applications, such as document summarization, sensor placement, and image segmentation. For all these applications, the key building block is how to compute the maximum value of a submodular function efficiently. We consider both the online and offline versions of the problem: in each iteration, the data set changes incrementally or is not changed, and a user can issue a query to maximize the function on a given subset of the data. The user can be malicious, issuing queries based on previous query results to break the competitive ratio for the online algorithm. Today, the best-known algorithm for online submodular function maximization has a running time of $O(n k d^2)$ where $n$ is the total number of elements, $d$ is the feature dimension and $k$ is the number of elements to be selected. We propose a new method based on a novel search tree data structure. Our algorithm only takes $\widetilde{O}(nk + kd^2 + nd)$ time

Case report: Bullous pemphigoid associated with sintilimab therapy for pMMR/MSS colorectal cancer

Immunotherapy has become a very effective treatment for many cancers. It has a unique set of immune system-related adverse effects, collectively known as immune-related adverse events (irAEs). Skin toxicities are the most common irAEs, of which bullous pemphigoid, although rare, is potentially life-threatening and affects patients’ survival. In this article, we report the treatment of bullous pemphigoid caused by programmed cell death protein-1 (PD-1) in a case of proficient mismatch repair (pMMR)/microsatellite stable (MSS) colorectal cancer. No significant adverse effects were observed in the patient after methylprednisone was tapered to 4 mg twice a day. No new skin lesions occurred recently in the patient and the original skin lesions healed. In particular, the patient’s immunotherapy was not stopped and the best outcome was a partial remission of the disease, lasting for more than 8 months