Aligning Recommendation and Conversation via Dual Imitation

Human conversations of recommendation naturally involve the shift of interests which can align the recommendation actions and conversation process to make accurate recommendations with rich explanations. However, existing conversational recommendation systems (CRS) ignore the advantage of user interest shift in connecting recommendation and conversation, which leads to an ineffective loose coupling structure of CRS. To address this issue, by modeling the recommendation actions as recommendation paths in a knowledge graph (KG), we propose DICR (Dual Imitation for Conversational Recommendation), which designs a dual imitation to explicitly align the recommendation paths and user interest shift paths in a recommendation module and a conversation module, respectively. By exchanging alignment signals, DICR achieves bidirectional promotion between recommendation and conversation modules and generates high-quality responses with accurate recommendations and coherent explanations. Experiments demonstrate that DICR outperforms the state-of-the-art models on recommendation and conversation performance with automatic, human, and novel explainability metrics.Comment: EMNLP 202

Drug-Eluting Stent Thrombosis The Kounis Hypersensitivity-Associated Acute Coronary Syndrome Revisited

The advent of drug-eluting stents (DES) has revolutionized the field of interventional cardiology. Their dramatic and persistent restenotic and target lesion revascularization advantages are unquestioned. However, concerns over the rare but potentially catastrophic risk of stent thrombosis (ST) have tempered universal acceptance of these devices. Although the precise mechanism of DES ST is undoubtedly multifactorial and as yet not fully elucidated, delayed or incomplete endothelial healing clearly plays a pivotal role. Detailed histopathological data have implicated a contributory allergic or hypersensitivity component, as verified by the Food and Drug Administration's Manufacturer and User Device Experience Center and the Research on Adverse Drug/device events And Reports (RADAR) project. These findings thus suggest a potential connection with the Kounis syndrome, the concurrence of acute coronary events with allergic, hypersensitivity, anaphylactic, or anaphylactoid reactions. Potential culprits responsible for this phenomenon include: arachidonic acid metabolites such as leukotrienes and thromboxane, proteolytic enzymes such as chymase and tryptase, histamine, cytokines, and chemokines. Additionally, inflammatory cells such as macrophages, T-lymphocytes, and mast cells are probably also contributory. Autopsy-confirmed infiltrates of various inflammatory cells including lymphocytes, plasma cells, macrophages, and eosinophils have been reported in all 3 vascular wall layers and are reminiscent of those associated with the Kounis syndrome. Although the concurrence of acute coronary syndromes with hypersensitivity reactions has been long established, the specific association with DES ST remains unproven. Potential incorporation of hypersensitivity suppressive agents might represent a promising paradigm shift from efficacy to safety in future DES designs

Think Twice: A Human-like Two-stage Conversational Agent for Emotional Response Generation

Towards human-like dialogue systems, current emotional dialogue approaches jointly model emotion and semantics with a unified neural network. This strategy tends to generate safe responses due to the mutual restriction between emotion and semantics, and requires rare emotion-annotated large-scale dialogue corpus. Inspired by the "think twice" behavior in human dialogue, we propose a two-stage conversational agent for the generation of emotional dialogue. Firstly, a dialogue model trained without the emotion-annotated dialogue corpus generates a prototype response that meets the contextual semantics. Secondly, the first-stage prototype is modified by a controllable emotion refiner with the empathy hypothesis. Experimental results on the DailyDialog and EmpatheticDialogues datasets demonstrate that the proposed conversational outperforms the comparison models in emotion generation and maintains the semantic performance in automatic and human evaluations.Comment: Accepted to AAMAS202

Abnormal Vasomotor Function of Porcine Coronary Arteries Distal to Sirolimus-Eluting Stents

ObjectivesThis study sought to determine vasomotor functional responses of conduit coronary artery distal to bare-metal stents (BMS), polymer-only stents (POLY), and sirolimus-eluting stents (SES) in a clinically relevant animal model.BackgroundDrug-eluting stents (DES) reduce in-stent restenosis, and also affect neointima formation and vascular remodeling in downstream coronary segments. Whether distal artery vasomotor function is also influenced by DES has not been determined.MethodsPigs (n = 12) received coronary stent implants, and hearts were harvested at 1 month. Arterial segments ≥15 mm distal to stents were excised and studied in an organ-chamber apparatus. Endothelium-dependent and endothelium-independent relaxation and contraction to classical agonists were measured.ResultsThe SES showed increased lumen area and reduced neointima; abnormal vasomotor function of conduit arteries distal to SES also was observed. Contraction to endothelin-1 was significantly enhanced for SES compared with both BMS and POLY. Endothelium-dependent relaxation to a maximal dose of substance P was attenuated for SES compared with both BMS and POLY (46 ± 6% vs. 71 ± 3% and 78 ± 3%, respectively, p < 0.001). Endothelium-independent relaxation to sodium nitroprusside was potentiated for SES, compared with BMS and POLY (100 ± 5% vs. 69 ± 7% and 77 ± 5%, respectively, p = 0.02).ConclusionsStent-based local delivery of sirolimus profoundly inhibited neointima formation but caused vasomotor dysfunction in distal conduit vessel segments. These observations suggest that distal coronary vasospasm may be more readily evoked in the presence of DES and contribute to pathophysiological sequela

Intracoronary and retrograde coronary venous myocardial delivery of adipose-derived stem cells in swine infarction lead to transient myocardial trapping with predominant pulmonary redistribution

OBJECTIVES: To examine the comparative fate of adipose-derived stem cells (ASCs) as well as their impact on coronary microcirculation following either retrograde coronary venous (RCV) or arterial delivery. BACKGROUND: Local delivery of ASCs to the heart has been proposed as a practical approach to limiting the extent of myocardial infarction. Mouse models of mesenchymal stem cell effects on the heart have also demonstrated significant benefits from systemic (intravenous) delivery, prompting a question about the advantage of local delivery. There has been no study addressing the extent of myocardial vs. systemic disposition of ASCs in large animal models following local delivery to the myocardium. METHODS: In an initial experiment, dose-dependent effects of ASC delivery on coronary circulation in normal swine were evaluated to establish a tolerable ASC dosing range for intracoronary (IC) delivery. In a set of subsequent experiments, an anterior acute myocardial infarction (AMI) was created by balloon occlusion of the proximal left anterior descending (LAD) artery, followed by either IC or RCV infusion of 10(7) (111)Indium-labeled autologous ASCs 6 days following AMI. Indices of microcirculatory resistance (IMR) and coronary flow reserve (CFR) were measured before sacrifices to collect tissues for analysis at 1 or 24 hr after cell delivery. RESULTS: IC delivery of porcine ASCs to normal myocardium was well tolerated up to a cumulative dose of 14 × 10(6) cells (approximately 0.5 × 10(6) cells/kg). There was evidence suggesting microcirculatory trapping of ASC: at unit doses of 50 × 10(6) ASCs, IMR and CFR were found to be persistently altered in the target LAD distribution at 7 days following delivery, whereas at 10 × 10(6) ASCs, only CFR was altered. In the context of recent MI, a significantly higher percentage of ASCs was retained at 1 hr with IC delivery compared with RCV delivery (57.2 ± 12.7% vs. 17.9 ± 1.6%, P = 0.037) but this initial difference was not apparent at 24 hr (22.6 ± 5.5% vs. 18.7 ± 8.6%; P = 0.722). In both approaches, most ASC redistributed to the pulmonary circulation by 24 hr postdelivery. There were no significant differences in CFR or IMR following ASC delivery to infarcted tissue by either route. CONCLUSIONS: Selective intravascular delivery of ASC by coronary arterial and venous routes leads to similarly limited myocardial cell retention with predominant redistribution of cells to the lungs. IC arterial delivery of ASC leads to only transiently greater myocardial retention, which is accompanied by obstruction of normal regions of coronary microcirculation at higher doses. The predominant intrapulmonary localization of cells following local delivery via both methods prompts the notion that systemic delivery of ASC might provide similarly beneficial outcomes while avoiding risks of inadvertent microcirculatory compromise

Optimal Production and Biochemical Properties of a Lipase from Candida albicans

Lipases from microorganisms have multi-faceted properties and play an important role in ever-growing modern biotechnology and, consequently, it is of great significance to develop new ones. In the present work, a lipase gene from Candida albicans (CaLIP10) was cloned and two non-unusual CUG serine codons were mutated into universal codons, and its expression in Pichia pastoris performed optimally, as shown by response surface methodology. Optimal conditions were: initial pH of culture 6.86, temperature 25.53 °C, 3.48% of glucose and 1.32% of yeast extract. The corresponding maximal lipolytic activity of CaLIP10 was 8.06 U/mL. The purified CaLIP10 showed maximal activity at pH 8.0 and 25 °C, and a good resistance to non-ionic surfactants and polar organic solvent was noticed. CaLIP10 could effectively hydrolyze coconut oil, but exhibited no obvious preference to the fatty acids with different carbon length, and diacylglycerol was accumulated in the reaction products, suggesting that CaLIP10 is a potential lipase for the oil industry

Subresultants with the Bézout Matrix

Colloque avec actes et comité de lecture. internationale.International audienceSubresultants are defined usually by means of subdeterminants of the Sylvester matrix. This paper gives an explicit and simple representation of the subresultants in terms of subdeterminants of the Bézout matrix and thus provides an alternative definition for subresultants. The representation and the lower dimensionality of the Bézout matrix lead to an effective technique for computing subresultant chains using determinant evaluation. Our preliminary experiments show that this technique is computationally superior to the standard technique based on pseudo-division for certain classes of polynomials

Advances in developing novel therapeutic strategies for Alzheimer’s disease

Abstract Alzheimer’s Disease (AD), the most prevalent neurodegenerative disease of aging, affects one in eight older Americans. Nearly all drug treatments tested for AD today have failed to show any efficacy. There is a great need for therapies to prevent and/or slow the progression of AD. The major challenge in AD drug development is lack of clarity about the mechanisms underlying AD pathogenesis and pathophysiology. Several studies support the notion that AD is a multifactorial disease. While there is abundant evidence that amyloid plays a role in AD pathogenesis, other mechanisms have been implicated in AD such as tangle formation and spread, dysregulated protein degradation pathways, neuroinflammation, and loss of support by neurotrophic factors. Therefore, current paradigms of AD drug design have been shifted from single target approach (primarily amyloid-centric) to developing drugs targeted at multiple disease aspects, and from treating AD at later stages of disease progression to focusing on preventive strategies at early stages of disease development. Here, we summarize current strategies and new trends of AD drug development, including pre-clinical and clinical trials that target different aspects of disease (mechanism-based versus non-mechanism based, e.g. symptomatic treatments, lifestyle modifications and risk factor management)