Concomitant protein pathogenesis in Parkinson’s disease and perspective mechanisms

Comorbidity is a common phenotype in Parkinson’s disease (PD). Patients with PD not only have motor deficit symptoms, but also have heterogeneous non-motor symptoms, including cognitive impairment and emotional changes, which are the featured symptoms observed in patients with Alzheimer’s disease (AD), frontotemporal dementia (FTD) and cerebrovascular disease. Moreover, autopsy studies have also confirmed the concomitant protein pathogenesis, such as the co-existences of α-synuclein, amyloid-β and tau pathologies in PD and AD patients’ brains. Here, we briefly summarize the recent reports regarding the comorbidity issues in PD from both clinical observations and neuropathological evidences. Furthermore, we provide some discussion about the perspective potential mechanisms underlying such comorbidity phenomenon, with a focus on PD and related neurodegenerative diseases

Does Pre-login Search Matter? Evidence from a Mobile Commerce Platform

An increasing number of consumers enjoy shopping through mobile devices. When consumers use a mobile app, they can choose whether to log in with their accounts. We argue that pre-login search plays a critical role in affecting consumers’ purchase decisions, although it has largely been overlooked in the literature. Using clickstream data, we adopt different econometric models to examine whether and how pre-login search affects the likelihood of purchase. Our results show that pre-login search behaviors are as important as post-login search to consumers’ purchase decisions. We also demonstrate that consumers’ purchase propensity increases at a diminishing rate with an increasing search effort during both pre- and post-login periods. Based on recommender systems (RSs) and paradox of choice theory, our results contribute to the burgeoning literature on consumer behavior in mobile commerce and provide novel insights to the strategic usage of RSs. Finally, we discuss theoretical and managerial implications

Adsorption and desorption characteristics of arsenic onto ceria nanoparticles

The rapid increase in the use of engineered nanoparticles [ENPs] has resulted in an increasing concern over the potential impacts of ENPs on the environmental and human health. ENPs tend to adsorb a large variety of toxic chemicals when they are emitted into the environment, which may enhance the toxicity of ENPs and/or adsorbed chemicals. The study was aimed to investigate the adsorption and desorption behaviors of arsenic on ceria NPs in aqueous solution using batch technique. Results show that the adsorption behavior of arsenic on ceria NPs was strongly dependent on pH and independent of ionic strength, indicating that the electrostatic effect on the adsorption of these elements was relatively not important compared to surface chemical reactions. The adsorption isotherms fitted very well to both the Langmuir and Freundlich models. The thermodynamic parameters (ΔH0, ΔS0, and ΔG0) for the adsorption of arsenic were determined at three different temperatures of 283, 303, and 323 K. The adsorption reaction was endothermic, and the process of adsorption was favored at high temperature. The desorption data showed that desorption hysteresis occurred at the initial concentration studied. High adsorption capacity of arsenic on ceria NPs suggests that the synergistic effects of ceria NPs and arsenic on the environmental systems may exist when they are released into the environment

Evolution of iron-rich intermetallics and its effect on the mechanical properties of Al–Cu–Mn–Fe–Si alloys after thermal exposure and high-temperature tensile testing

Si addition is commonly used to modify the iron-rich intermetallics in Al–Cu–Mn–Fe alloys, which is beneficial to increasing the use of recycled aluminum. Most of the available research has focused on the effect of Si content on the room-temperature mechanical properties of Al–Cu–Mn–Fe alloys. To expand the application of Al–Cu–Mn–Fe–Si alloys as light heat-resistant structural components in the automotive and aerospace industries, it is of great importance to investigate the evolution of iron-rich intermetallics and its effect on the fracture behavior of Al–Cu–Mn–Fe–Si alloys after thermal exposure and high-temperature tensile testing. In this work, the evolution of iron-rich intermetallics and the high-temperature mechanical properties of heat-treated Al-6.5Cu-0.6Mn-0.5Fe alloys with different Si contents after thermal exposure and high-temperature tensile testing were assessed by tensile tests, image analysis, scanning electron microscopy, X-Ray diffraction, transmission electron microscopy, and atomic probe tomography. The results indicate that the Al-6.5Cu-0.6Mn-0.5Fe alloys with 0.1Si and 0.5Si additions have excellent and stable high-temperature mechanical properties after long thermal exposure, which are better than those of most heat-resistant Al alloys. The high performance of the high-temperature mechanical properties is attributed to the high heat resistance of secondary intermetallics and precipitated particles. The addition of Si is detrimental to the strength of Al-6.5Cu-0.6Mn-0.5Fe alloys after long thermal exposure. This can be attributed to the solid-state phase transformation of iron-rich intermetallics from α-Fe to β-Fe, which results in the increase of needle-like Fe-rich phases and Si particles, the agglomeration of secondary intermetallics, and the consumption of Al$_{2}$Cu phases

Service Quality Evaluation of Ancient City Scenic Spots Based on Tourists' Perceptions: An Example of Qingzhou Ancient

From the perspective of tourist service perception, this study is the first to evaluate the service quality of the Qingzhou Ancient City tourist scenic area. The study adopts the SERVQUAL model and modifies it into a tourist service quality model specifically designed for ancient city scenic areas to measure the gap between tourists' perceived service quality and expected service quality in the context of the ancient city scenic area. The study also examines the influence of each dimension of this model on tourist satisfaction. Qingzhou Ancient City is chosen as a case study because it has a relatively high rating among ancient city scenic areas in China. The results indicate that tourists' overall satisfaction with the service in Qingzhou Ancient City is average. Among the six dimensions of this model, "historical and cultural significance," "assurance," and "empathy" are identified as key predictors of tourist satisfaction. This paper discusses the research findings and elucidates their managerial implications

A Novel Control Strategy of DFIG Based on the Optimization of Transfer Trajectory at Operation Points in the Islanded Power System

A novel control strategy based on the optimization of transfer trajectory at operation points for DFIG is proposed. Aim of this control strategy is to reduce the mechanical fatigue of DFIG caused by the frequent adjustment of rotating speed and pitch angle when operating in the islanded power system. Firstly, the stability of DFIG at different operation points is analyzed. Then an optimization model of transfer trajectory at operation points is established, with the minimum synthetic adjustment amount of rotating speed and pitch angle as the objective function and with the balance of active power and the stability of operation points as the constraint conditions. Secondly, the wind speed estimator is designed, and the control strategy of pitch system is improved to cooperate with the indirect stator flux orientation control technology for rotor-side inverter control. Then by the coordination control of its rotating speed and pitch angle, an operation trajectory controller is established to ensure the islanded operation of DFIG along the optimal transfer trajectory. Finally, the simulation results show that the proposed control strategy is technical feasibility with good performance