Unsupervised Sentiment Analysis by Transferring Multi-source Knowledge

Sentiment analysis (SA) is an important research area in cognitive computation—thus, in-depth studies of patterns of sentiment analysis are necessary. At present, rich-resource data-based SA has been well-developed, while the more challenging and practical multi-source unsupervised SA (i.e., a target-domain SA by transferring from multiple source domains) is seldom studied. The challenges behind this problem mainly locate in the lack of supervision information, the semantic gaps among domains (i.e., domain shifts), and the loss of knowledge. However, existing methods either lack the distinguishable capacity of the semantic gaps among domains or lose private knowledge. To alleviate these problems, we propose a two-stage domain adaptation framework. In the first stage, a multi-task methodology-based shared-private architecture is employed to explicitly model the domain-common features and the domain-specific features for the labeled source domains. In the second stage, two elaborate mechanisms are embedded in the shared-private architecture to transfer knowledge from multiple source domains. The first mechanism is a selective domain adaptation (SDA) method, which transfers knowledge from the closest source domain. And the second mechanism is a target-oriented ensemble (TOE) method, in which knowledge is transferred through a well-designed ensemble method. Extensive experiment evaluations verify that the performance of the proposed framework outperforms unsupervised state-of-the-art competitors. What can be concluded from the experiments is that transferring from very different distributed source domains may degrade the target-domain performance, and it is crucial to choose proper source domains to transfer from.

     

Brainstem atrophy in the early stage of Alzheimer’s disease: a voxel-based morphometry study

Brain Imaging and Behavior - Postmortem studies on patients with Alzheimer’s disease (AD) have confirmed that the dorsal raphe nucleus (DRN) in the brainstem is the first brain structure...     

Synthesis and Photovoltaic Properties of D–A Copolymers Based on 11,12‐Difluorodibenzo[a,c]phenazine Acceptor Unit

Four conjugated D‐π‐A copolymers, P1 – P4 , based on 11,12‐difluorodibenzo[a,c]phenazine as an acceptor unit, benzodithiophene (BDT) with an alkoxy side chain ( P1 and P2 ) or thiophene‐conjugated side chain ( P3 and P4 ) as a donor unit, and thiophene π‐bridges, are designed and synthesized to investigate the effect of the side‐chain nature and position on the photovoltaic performance of the conjugated polymer donor materials in polymer solar cells (PSCs). It is found that the copolymers of P3 and P4 with thiophene conjugated side chains on the BDT unit demonstrate broader absorption and better photovoltaic performance than that of P1 and P2 with alkoxy side chains on the BDT unit. The photovoltaic performance of P1 and P3 with an alkyl side chain on the thiophene π‐bridge close to the acceptor unit is improved over that of P2 and P4 with an alkyl side chain on the thiophene π‐bridge close to the donor unit, due to the lower steric hindrance of P1 and P3 . The results indicate that side‐chain engineering is very important for improving the photovoltaic performance of conjugated polymer donor materials.

     

Endothelial progenitor cells: the promise of cell-based therapies for acute lung injury

Background

Endothelial progenitor cells (EPCs) are defined as a special type of stem cell that have been found to directly incorporate into injured vessels and that participate in angiogenesis and reconstruction by differentiation into endothelial cells. EPCs are widely used to therapeutically treat cardiovascular disease, limb ischemia and vascular repair. However, the role of EPCs in inflammatory diseases, especially in lung injury, is less studied.

Objective

To investigate the application of EPCs to vascular repair, and the role of EPCs in acute lung injury (ALI) and acute respiratory distress syndrome (ARDS).

Methods

A computer-based online search was performed in the PubMed database and Web of Science database for articles published, concerning EPCs, angiogenesis, ALI/ARDS and stem cell transplantation

Conclusion

EPCs have a therapeutic potential for vascular regeneration and may emerge as novel strategy for the diseases that are associated with ALI/ARDS.     

New insights into the beneficial roles of dispersants in reducing negative influence of Mg2+ on molybdenite flotation

Due to the shortage of freshwater, seawater has been widely considered for mineral flotation. However, the presence of Mg²⁺ in seawater plays an apparently negative role. In this work, two dispersants (i.e., sodium silicate (SS) and sodium hexametaphosphate (SH)) were applied to reduce the detrimental effects of Mg²⁺ on the flotation of molybdenite (MoS₂). Various measurements including contact angle, zeta potential, FTIR and XPS were carried out to understand the impacts of these two dispersants on MoS₂ flotation. Results indicate that both dispersants prevented the adsorption of colloidal Mg(OH)₂ onto MoS₂ surface under alkaline conditions, thereby improving MoS₂ floatability. In addition, both dispersants are physically adsorbed on MoS₂ surface, but chemically adsorbed on Mg(OH)₂ surface. In addition, the extended Derjaguin–Landau–Verwey–Overbeek (DLVO) calculation suggests that both SS and SH reverse the total interaction energies between MoS₂ and colloidal Mg(OH)₂ from negative (attraction force) to positive (repulsive force), with the impact of SH being more significant.

Due to the shortage of freshwater, seawater has been widely considered for mineral flotation.     

Neuroprotective constituents from the aerial parts of Cannabis sativa L. subsp. sativa

Five new compounds including three new cannabinoids, cannabisativas A–C (1–3), two new phenolic acids, (7Z,9Z)-cannabiphenolic acid A (4) and (8S,9Z)-cannabiphenolic acid B (5), together with twelve known compounds (6–17), were isolated from the aerial parts of Cannabis sativa L. subsp. sativa. The structures of 1–5 were established on the basis of extensive 1D, 2D NMR and HRESIMS analysis. The absolute configurations were determined by comparison between their experimental and calculated spectra of electronic circular dichroism (ECD) or the modified Mosher''s method. The neuroprotective effects of the compounds 1–17 were evaluated on PC 12 cells. Compounds 12, 13 and 15 showed potential protective effects against H₂O₂-induced damage.

5 new compounds including 3 new cannabinoids, cannabisativas A–C, 2 new phenolic acids, (7Z,9Z)-cannabiphenolic acid A and (8S,9Z)-cannabiphenolic acid B, together with 12 known compounds, were isolated from the aerial parts of Cannabis sativa L. subsp. sativa.     

Increased serum brain-derived neurotrophic factor with high-intensity interval training in stroke patients: A randomized controlled trial

BackgroundPhysiological adaptations of stroke patients after high-intensity interval training (HIIT) and moderate-intensity continuous training (MICT) remain unclear.ObjectiveThis study determined the HIIT and MICT effects on aerobic capacity, cerebral oxygenation, peak cardiac output (CO), and serum brain-derived neurotrophic factor (BDNF) in stroke patients.MethodsWe included 23 stroke patients with age about 55 years and stroke duration > 24 months; participants completed 36 sessions of exercise training for 30 min; 13 were randomly assigned to perform MICT at 60% of peak oxygen consumption (VO_2peak) and 10 to perform HIIT at alternating 80% (3 min) and 40% (3 min) VO_2peak. Before and after interventions, we evaluated VO_2peak, peak CO, arteriovenous oxygen difference (AV O_2diff), bilateral frontal cortex oxygenation (relative changes of oxyhemoglobin Δ[O₂Hb], deoxyhemoglobin Δ[HHb], and total hemoglobin Δ[THb] levels), serum brain-derived neurotrophic factor (BDNF) level, and fluorescent cell staining for neuron morphology and percentage of cell-bearing neurites (% neurites).ResultsHIIT induced significant increases in VO_2peak (P = 0.008), CO (P = 0.038), Δ[HHb] (P = 0.046), Δ[THb] (P = 0.046), and serum BDNF level (P = 0.012). The improvement in VO_2peak was significantly greater with HIIT than MICT (20.7% vs. 9.8%, P = 0.031), as was AV O_2diff (P = 0.041), Δ[HHb] (P = 0.027), and serum BDNF level (P < 0.001). HIIT facilitated neuron dendritic protrusions (greater % neurites, P = 0.012) with prominent redistribution of mitochondria.ConclusionAs compared with MICT, HIIT-improved aerobic capacity by increasing systemic tissue O₂ extraction in stroke patients. Increased cerebral O₂ utilization in the involved hemisphere was also identified after HIIT. These physiological adaptations may be associated with increased serum BDNF level. In vitro dendritic growth in neurons treated with serum from HIIT participants may imply significant effects on neuron activities as compared with MICT.ClinicalTrials.gov identifierNCT04135391.     

瑞马唑仑临床应用的研究进展

瑞马唑仑是一种新型的超短效苯二氮?类药,它具有像瑞芬太尼一样器官独立的新陈代谢作用,并能像咪达唑仑一样作用于γ氨基丁酸（GABA）受体。其起效快,恢复迅速,对肝肾功能及血流动力学影响较轻,且能够被氟马西尼快速逆转,这些药理作用使瑞马唑仑在理论上成为较理想的镇静药物。本文主要就瑞马唑仑的作用机制、药代动力学、对器官功能的影响、临床应用研究进展进行综述,为其临床应用提供理论依据。     

Diagnostic accuracy of quantitative flow ratio (QFR) and vessel fractional flow reserve (vFFR) estimated retrospectively by conventional radiation saving X-ray angiography

Background

Angiography derived FFR reveals good performance in assessing intermediate coronary stenosis. However, its performance under contemporary low X-ray frame and pulse rate settings is unknown. We aim to validate the feasibility and performance of quantitative flow ratio (QFR) and vessel fractional flow reserve (vFFR) under such angiograms.

Methods

This was an observational, retrospective, single center cohort study. 134 vessels in 102 patients, with angiograms acquired under 7.5fps and 7pps mode, were enrolled. QFR (fQFR and cQFR) and vFFR were validated with FFR as the gold standard. A conventional manual and a newly developed algorithmic exclusion method (M and A group) were both evaluated for identification of poor-quality angiograms.

Results

Good agreement between QFR/vFFR and FFR were observed in both M and A group, except for vFFR in the M group. The correlation coefficients between fQFR/cQFR/vFFR and FFR were 0.6242, 0.5888, 0.4089 in the M group, with r_vFFR significantly lower than r_fQFR (p?=?0.0303), and 0.7055, 0.6793, 0.5664 in the A group, respectively. AUCs of detecting lesions with FFR?≤?0.80 were 0.852 (95% CI 0.722–0.913), 0.858 (95% CI 0.778–0.917), 0.682 (95% CI 0.586–0.768), for fQFR/cQFR/vFFR in the M group, while vFFR performed poorer than fQFR (p?=?0.0063) and cQFR (p?=?0.0054). AUCs were 0.898 (95% CI 0.811–0.945), 0.892 (95% CI 0.803–0.949), 0.843 (95% CI 0.746–0.914) for fQFR/cQFR/vFFR in the A group. AUC_vFFR was significantly higher in the A group than that in the M group (p?=?0.0399).

Conclusions

QFR/vFFR assessment is feasible under 7.5fps and 7pps angiography, where cQFR showed no advantage compared to fQFR. Our newly developed algorithmic exclusion method could be a better method of selecting angiograms with adequate quality for angiography derived FFR assessment.