250 research outputs found

    Information core optimization using Evolutionary Algorithm with Elite Population in recommender systems

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    Recommender system (RS) plays an important role in helping users find the information they are interested in and providing accurate personality recommendation. It has been found that among all the users, there are some user groups called ā€œcore usersā€ or ā€œinformation coreā€ whose historical behavior data are more reliable, objective and positive for making recommendations. Finding the information core is of great interests to greatly increase the speed of online recommendation. There is no general method to identify core users in the existing literatures. In this paper, a general method of finding information core is proposed by modelling this problem as a combinatorial optimization problem. A novel Evolutionary Algorithm with Elite Population (EA-EP) is presented to search for the information core, where an elite population with a new crossover mechanism named as ordered crossover is used to accelerate the evolution. Experiments are conducted on Movielens (100k) to validate the effectiveness of our proposed algorithm. Results show that EA-EP is able to effectively identify core users and leads to better recommendation accuracy compared to several existing greedy methods and the conventional collaborative filter (CF). In addition, EA-EP is shown to significantly reduce the time of online recommendation

    Analysis of risk factors for recurrence in infertile endometrial cancer patients after in vitro fertilization treatment

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    PurposeTo investigate the oncologic outcomes of patients with early-stage endometrioid endometrial cancer (EEC) treated with in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI) following fertility-sparing treatment (FST).MethodsA total of 62 patients who underwent IVF/ICSI treatment in a single fertility center between June 2010 and December 2021 after conservative treatment for early-stage EEC were assigned to a recurrence group and a non-recurrence group. Their clinical characteristics and disease outcomes were retrospectively evaluated.ResultsThe 62 women with complete remission (CR) after FST for EEC underwent 103 IVF cycles, resulting in 41 fresh embryo transfers (ETs) and 70 frozenā€“thawed transfers; 27 (43.55%) achieved clinical pregnancies, and 20 (32.26%) gave birth to a total of 23 live neonates. Additionally, nine patients had live births from natural pregnancies after IVF failure, bringing the cumulative live birth rate to 46.77% (29/62). After a median follow-up period of 53.88 months (range 20.2ā€“127.5 months), 17 patients (27.42%) experienced recurrence within 2.8 to 57.9 months after the first controlled ovarian stimulation (COS). The probability of relapse at 1, 2, and 3 years after the initiation of COS was 14.52% (9/62), 21% (13/62), and 25.81% (16/62), respectively. Factors such as the time to CR, the time to IVF, the frequency of COS, maintenance treatment before IVF, and histology type were not found to significantly affect recurrence (p = 0.079, 0.182, 0.093, 0.267, and 0.41, respectively). Live births (hazard ratio (HR): 0.28, 95% CI: 0.082ā€“0.962, p = 0.043) and the protocol of letrozole plus gonadotropin-releasing hormone (GnRH) antagonist/agonist used during IVF (HR: 0.1, 95% CI: 0.011ā€“0.882, p = 0.038) were identified as independent favorable factors for recurrence.ConclusionsLive birth was associated with decreased recurrence of EEC. Reducing estrogen levels during COS may serve to mitigate the risk of endometrial cancer recurrence

    Facile synthesis of carbon-11-labeled sEH/PDE4 dual inhibitors as new potential PET agents for imaging of sEH/PDE4 enzymes in neuroinflammation

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    To develop PET tracers for imaging of neuroinflammation, new carbon-11-labeled sEH/PDE4 dual inhibitors have been synthesized. The reference standard N-(4-methoxy-2-(trifluoromethyl)benzyl)benzamide (1) and its corresponding desmethylated precursor N-(4-hydroxy-2-(trifluoromethyl)benzyl)benzamide (2) were synthesized from (4-methoxy-2-(trifluoromethyl)phenyl)methanamine and benzoic acid in one and two steps with 84% and 49% overall chemical yield, respectively. The standard N-(4-methoxy-2-(trifluoromethyl)benzyl)-1-propionylpiperidine-4-carboxamide (MPPA, 4) and its precursor N-(4-hydroxy-2-(trifluoromethyl)benzyl)-1-propionylpiperidine-4-carboxamide (5) were synthesized from methyl 4-piperidinecarboxylate, propionyl chloride and (4-methoxy-2-(trifluoromethyl)phenyl)methanamine in two and three steps with 62% and 34% overall chemical yield, respectively. The target tracers N-(4-[11C]methoxy-2-(trifluoromethyl)benzyl)benzamide ([11C]1) and N-(4-[11C]methoxy-2-(trifluoromethyl)benzyl)-1-propionylpiperidine-4-carboxamide ([11C]MPPA, [11C]4) were prepared from their corresponding precursors 2 and 5 with [11C]CH3OTf through O-[11C]methylation and isolated by HPLC combined with SPE in 25ā€“35% radiochemical yield, based on [11C]CO2 and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the molar activity (AM) at EOB was 370ā€“740ā€ÆGBq/Ī¼mol with a total synthesis time of 35ā€“40-minutes from EOB

    Synthesis of carbon-11-labeled 5-HT6R antagonists as new candidate PET radioligands for imaging of Alzheimerā€™s disease

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    Carbon-11-labeled serotonin (5-hydroxytryptamine) 6 receptor (5-HT6R) antagonists, 1-[(2-bromophenyl)sulfonyl]-5-[11C]methoxy-3-[(4-methyl-1-piperazinyl)methyl]-1H-indole (O-[11C]2a) and 1-[(2-bromophenyl)sulfonyl]-5-methoxy-3-[(4-[11C]methyl-1-piperazinyl)methyl]-1H-indole (N-[11C]2a), 5-[11C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1-(phenylsulfonyl)-1H-indole (O-[11C]2b) and 5-methoxy-3-((4-[11C]methylpiperazin-1-yl)methyl)-1-(phenylsulfonyl)-1H-indole (N-[11C]2b), 1-((4-isopropylphenyl)sulfonyl)-5-[11C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1H-indole (O-[11C]2c) and 1-((4-isopropylphenyl)sulfonyl)-5-methoxy-3-((4-[11C]methylpiperazin-1-yl)methyl)-1H-indole (N-[11C]2c), 1-((4-fluorophenyl)sulfonyl)-5-[11C]methoxy-3-((4-methylpiperazin-1-yl)methyl)-1H-indole (O-[11C]2d) and 1-((4-fluorophenyl)sulfonyl)-5-methoxy-3-((4-[11C]methylpiperazin-1-yl)methyl)-1H-indole (N-[11C]2d), were prepared from their O- or N-desmethylated precursors with [11C]CH3OTf through O- or N-[11C]methylation and isolated by HPLC combined with SPE in 40ā€“50% radiochemical yield, based on [11C]CO2 and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the molar activity (MA) at EOB was 370ā€“740ā€ÆGBq/Ī¼mol with a total synthesis time of āˆ¼40-min from EOB

    Synthesis of N-(3-(4-[11C]methylpiperazin-1-yl)āˆ’1-(5-methylpyridin-2-yl)āˆ’1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide as a new potential PET agent for imaging of IRAK4 enzyme in neuroinflammation

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    The reference standard N-(3-(4-methylpiperazin-1-yl)āˆ’1-(5-methylpyridin-2-yl)āˆ’1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide (9) and its demethylated precursor N-(1-(5-methylpyridin-2-yl)āˆ’3-(piperazin-1-yl)āˆ’1H-pyrazol-5-yl)pyrazolo[1,5-Ī±]pyrimidine-3-carboxamide (8) were synthesized from pyrazolo[1,5-a]pyrimidine-3-carboxylic acid and ethyl 2-cyanoacetate with overall chemical yield 13% in nine steps and 14% in eight steps, respectively. The target tracer N-(3-(4-[11C]methylpiperazin-1-yl)āˆ’1-(5-methylpyridin-2-yl)āˆ’1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide ([11C]9) was prepared from its precursor with [11C]CH3OTf through N-[11C]methylation and isolated by HPLC combined with SPE in 50ā€“60% radiochemical yield, based on [11C]CO2 and decay corrected to EOB. The radiochemical purity was >99%, and the specific activity at EOB was 370ā€“1110 GBq/Ī¼mol

    Observation of a multitude of correlated states at the surface of bulk 1T-TaSe2_2 crystals

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    The interplay between electron-electron interactions and structural ordering can yield exceptionally rich correlated electronic phases. We have used scanning tunneling microscopy to investigate bulk 1T-TaSe2 and have uncovered surprisingly diverse correlated surface states thereof. These surface states exhibit the same in-plane charge density wave ordering but dramatically different electronic ground states ranging from insulating to metallic. The insulating variety of surface state shows signatures of a decoupled surface Mott layer. The metallic surface states, on the other hand, exhibit zero-bias peaks of varying strength that suggest Kondo phases arising from coupling between the Mott surface layer and the metallic bulk of 1T-TaSe2. The surface of bulk 1T-TaSe2 thus constitutes a rare realization of the periodic Anderson model covering a wide parameter regime, thereby providing a model system for accessing different correlated phenomena in the same crystal. Our results highlight the central role played by strong correlations in this material family

    Impaired large-scale corticoā€“hippocampal network connectivity, including the anterior temporal and posterior medial systems, and its associations with cognition in patients with first-episode schizophrenia

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    Background and objectiveThe corticoā€“hippocampal network is an emerging neural framework with striking evidence that it supports cognition in humans, especially memory; this network includes the anterior temporal (AT) system, the posterior medial (PM) system, the anterior hippocampus (aHIPPO), and the posterior hippocampus (pHIPPO). This study aimed to detect aberrant patterns of functional connectivity within and between large-scale corticoā€“hippocampal networks in first-episode schizophrenia patients compared with a healthy control group via resting-state functional magnetic resonance imaging (rs-fMRI) and to explore the correlations of these aberrant patterns with cognition.MethodsA total of 86 first-episode, drug-naĆÆve schizophrenia patients and 102 healthy controls (HC) were recruited to undergo rs-fMRI examinations and clinical evaluations. We conducted large-scale edge-based network analysis to characterize the functional architecture of the corticoā€“hippocampus network and investigate between-group differences in within/between-network functional connectivity. Additionally, we explored the associations of functional connectivity (FC) abnormalities with clinical characteristics, including scores on the Positive and Negative Syndrome Scale (PANSS) and cognitive scores.ResultsCompared with the HC group, schizophrenia patients exhibited widespread alterations to within-network FC of the corticoā€“hippocampal network, with decreases in FC involving the precuneus (PREC), amygdala (AMYG), parahippocampal cortex (PHC), orbitofrontal cortex (OFC), perirhinal cortex (PRC), retrosplenial cortex (RSC), posterior cingulate cortex (PCC), angular gyrus (ANG), aHIPPO, and pHIPPO. Schizophrenia patients also showed abnormalities in large-scale between-network FC of the corticoā€“hippocampal network, in the form of significantly decreased FC between the AT and the PM, the AT and the aHIPPO, the PM and the aHIPPO, and the aHIPPO and the pHIPPO. A number of these signatures of aberrant FC were correlated with PANSS score (positive, negative, and total score) and with scores on cognitive test battery items, including attention/vigilance (AV), working memory (WM), verbal learning and memory (Verb_Lrng), visual learning and memory (Vis_Lrng), reasoning and problem-solving (RPS), and social cognition (SC).ConclusionSchizophrenia patients show distinct patterns of functional integration and separation both within and between large-scale corticoā€“hippocampal networks, reflecting a network imbalance of the hippocampal long axis with the AT and PM systems, which regulate cognitive domains (mainly Vis_Lrng, Verb_Lrng, WM, and RPS), and particularly involving alterations to FC of the AT system and the aHIPPO. These findings provide new insights into the neurofunctional markers of schizophrenia
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