2,665 research outputs found

    Mechanism of mesenchymal stem cells as a multitarget disease-modifying therapy for parkinson's disease.

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    Parkinson's disease (PD) is one of the most prevalent neurodegenerative disorders, affecting the basal nuclei, causing impairment of motor and cognitive functions. Loss of dopaminergic (DAergic) neurons or their degeneration and the aggregation of Lewy bodies is the hallmark of this disease. The medications used to treat PD relieve the symptoms and maintain quality of life, but currently, there is no cure. There is a need for the development of therapies that can cease or perhaps reverse neurodegeneration effectively. With the rapid advancements in cell replacement therapy techniques, medical professionals are trying to find a cure by which restoration of dopamine neurotransmitters can occur. Researchers have started focusing on cell-based therapies using mesenchymal stem cells (MSCs) due to their abundance in the body, the ability of proliferation, and immunomodulation. Here we review the MSC-based treatment in Parkinson's disease and the various mechanisms it repairs DAergic neurons in parkinsonian patients

    Multifunctional Lightweight Aggregate Containing Phase Change Material and Water for Damage Mitigation of Concrete

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    This paper presents an innovative concept of multifunctional lightweight aggregate, which is produced by loading phase change material (PCM) into the interior of lightweight sand (LWS) and sealing the surface pores using water. The PCM loaded in the LWS functionalizes it as a temperature management agent in concrete, and the water in surface pores enables internal curing. It has been found that the particle shape and pore structure of crushed expanded shale LWS makes it an ideal carrier for PCM, loading sufficient PCM and maintaining better (compared to natural sand) mechanical interlocking. When coupled with the internal curing effect, the LWS yields an interpenetrated interfacial transition zone with the cement paste, leading to a compressive strength comparable to natural sand mortar. The hydration products penetrated into the surface pores also helps stabilizing PCM in the LWS. However, any PCM residuum non-stabilized in LWS tends to compromise the strength. Under an optimized scenario, the LWS-PCM composite aggregate is produced by grading, PCM impregnation, rinsing, and water saturation. A mortar proportioned with this aggregate yields comparable 28-day strength to the reference mortar and a 63% lower autogenous shrinkage (because of internal curing). Furthermore, it shows a 7 ⁰C lower semi-adiabatic temperature rise, delayed appearance of peak temperature and gentled cooling curve. These results indicate that the functional aggregate can effectively mitigate the risk of thermal cracking in early-age mass concrete. In addition, PCM remained in aged concrete has a potential to improve its adaptivity to temperature fluctuations in the service environment

    Parity-violating asymmetry of WW bosons produced in pp-pp collisions

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    The parity-violating asymmetry is an ideal tool to study the quark helicity distribution in the proton. We study the parity-violating asymmetry of W±W^{\pm} bosons produced by longitudinally polarized pp-pp collision in RHIC, based on predictions of quark distributions of the proton in the SU(6) quark-spectator-diquark model and a perturbative QCD based counting rule analysis. We find that the two models give nearly equal asymmetry for W+W^+ but that for WW^- quite different. Therefore future experiments on such quantity can help to clarify different predictions of the value Δd(x)/d(x)\Delta d(x)/d(x) at x1x \to 1 in the proton.Comment: 11 Latex pages, 9 figures, final version to appear in NP

    Vascular complications in adults and pediatrics live-donor renal transplantation: 3 decades of single centre experience

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    We analyzed the incidence of vascular complications in adults and pediatrics live donor renal transplantations over 3 decades and compared its impact upon patient and graft survival in both groups.Material and methods: Between March 1976 and December 2005, 1785 live-donor renal transplantswere performed in a single institute, of the 1546 adults and 239 pediatric (age ≤18 years). The incidence of different types of vascular complications were determined in both groups. Long term patient and graft survival in patients with or without vascular complications and in various types of vascular complications were calculated & compared in both groups.Results: The overall incidence of vascular complications was 2.9%, it was equally 2.9% in both groups. In adults, 46 complications in 45 patients included 16 arterial, 10 renal artery thrombosis (0.6%), 2 cases of spasm in renal artery(0.1%), renal artery stenosis in 5 (0.3%), renal vein thrombosis in one (0.06%) and hemorrhagic complications in 28 patients whereas there were no thrombotic complications in the pediatric group, 6 case of hemorrhage (2.5%) and one case of renal artery stenosis (0.4%). There is steady decrease of vascular complications over the last 3 decades. The vascular complications significantly adverse patient and graft survival in both groups (p<0.001). The 5-years patient and graft survival in adults and pediatrics with or without vascular complications were 59.5 ± 9.2%, 89.14 ± 0.89%, 57.5 ± 18.7% and 90.18 ± 2.2% for the patient and 40.14 ± 7.75%, 97.79 ± 1.14%, 28.57 ± 17.07% and 77.18 ± 3.02% for the graft. There is no statistical significant difference in either patient or graft survival in thrombotic, stenotic or hemorrhagic complications in adult or hemorrhagic complications in the pediatric group (p=0.22 and p=0.142 respectively).Conclusions: There is no increase in incidence of vascular complications in pediatrics than adult transplants. The survival either graft or patient is comparable between adult and pediatric with or without vascular complications and the subgroups of vascular complications

    Engineering students' approaches to learning and views on collaboration: How do both evolve in a PBL environment and what are their contributing and constraining factors?

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    Background: This study investigated the development of engineering students' approaches to learning and views on collaboration in a PBL environment. Material and methods: An explanatory mixed research approach was employed with participants from four PBL-implementing engineering courses in Qatar and China. 197students responded to two surveys, and 168 students participated in group interviews. Results: While the study reveals increased adoption of deep approaches to learning on team projects, little influence on surface approaches to learning was found. The study also provides evidence supporting the positive relationship between students' adoption of deep learning approaches and their acknowledgement of values of collaboration in teamwork. Conclusions: This study suggests that while PBL characteristics may support deep learning, certain factors may underpin surface learning, including a feeling of insecurity during first experiences with it, lack of skills, and assessment methods that favor surface learning. Further efforts on engaging students with PBL may benefit both deep learning and team effectiveness.Scopu

    Emotion classification and crowd source sensing; a lexicon based approach

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    In today's world, social media provides a valuable platform for conveying expressions, thoughts, point-of-views, and communication between people, from diverse walks of life. There are currently approximately 2.62 billion active users' social networks, and this is expected to exceed 3 billion users by 2021. Social networks used to share ideas and information, allowing interaction across communities, organizations, and so forth. Recent studies have found that the typical individual uses these platforms between 2 and 3 h a day. This creates a vast and rich source of data that can play a critical role in decision-making for companies, political campaigns, and administrative management and welfare. Twitter is one of the important players in the social network arena. Every scale of companies, celebrities, different types of organizations, and leaders use Twitter as an instrument for communicating and engaging with their followers. In this paper, we build upon the idea that Twitter data can be analyzed for crowd source sensing and decision-making. In this paper, a new framework is presented that uses Twitter data and performs crowd source sensing. For the proposed framework, real-time data are obtained and then analyzed for emotion classification using a lexicon-based approach. Previous work has found that weather, understandably, has an impact on mood, and we consider these effects on crowd mood. For the experiments, weather data are collected through an application-programming-interface in R and the impact of weather on human sentiments is analyzed. Visualizations of the data are presented and their usefulness for policy/decision makers in different applications is discussed

    Microstructural and mechanical properties analysis of extruded Sn–0.7Cu solder alloy

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    AbstractThe properties and performance of lead-free solder alloys such as fluidity and wettability are defined by the alloy composition and solidification microstructure. Rapid solidification of metallic alloys is known to result in refined microstructures with reduced microsegregation and improved mechanical properties of the final products as compared to normal castings. The rapidly solidified Sn-based solders by melt spinning were shown to be suitable for soldering with low temperature and short soldering duration. In the present study, rapidly solidified Sn–0.7wt.%Cu droplets generated by impulse atomization (IA) were achieved as well as directional solidification under transient conditions at lower cooling rate. This paper reports on a comparative study of the rapidly solidified and the directionally solidified samples. Different but complementary characterization techniques were used to fully analyze the solidification microstructures of the samples obtained under the two cooling regimes. These include X-ray diffractometry (XRD) and scanning electron microscopy (SEM). In order to compare the tensile strength and elongation to fracture of the directionally solidified ingot and strip castings with the atomized droplet, compaction and extrusion of the latter were carried out. It was shown that more balanced and superior tensile mechanical properties are available for the hot extruded samples from compacted as-atomized Sn–0.7wt.%Cu droplets. Further, elongation-to-fracture was 2–3× higher than that obtained for the directionally solidified samples

    Top quark pair production via polarized and unpolarized photons in Supersymmetric QCD

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    QCD corrections to top quark pair production via fusion of both polarized and unpolarized photons are calculated in Supersymmetric Model. The corrections are found to be sizable. The dependence of the corrections on the masses of the supersymmetric particles is also investigated. Furthermore, we studied CP asymmetry effects arising from the complex couplings in the MSSM. The CP violating parameter can reach 10210^{-2} for favorable parameter values.Comment: 26 pages, LaTex, including 12 figures in 12 eps files. submitted to Phys. Rev.

    Noiseless nonreciprocity in a parametric active device

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    Nonreciprocal devices such as circulators and isolators belong to an important class of microwave components employed in applications like the measurement of mesoscopic circuits at cryogenic temperatures. The measurement protocols usually involve an amplification chain which relies on circulators to separate input and output channels and to suppress backaction from different stages on the sample under test. In these devices the usual reciprocal symmetry of circuits is broken by the phenomenon of Faraday rotation based on magnetic materials and fields. However, magnets are averse to on-chip integration, and magnetic fields are deleterious to delicate superconducting devices. Here we present a new proposal combining two stages of parametric modulation emulating the action of a circulator. It is devoid of magnetic components and suitable for on-chip integration. As the design is free of any dissipative elements and based on reversible operation, the device operates noiselessly, giving it an important advantage over other nonreciprocal active devices for quantum information processing applications.Comment: 17 pages, 4 figures + 12 pages Supplementary Informatio

    Working Across Professions to Develop the Interprofessional Education Curriculum Pathway

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    This poster presents the assessment of curriculum through the Interprofessional Education committee, which was created in 2015 with the support of the Deans of the John A. Burns School of Medicine, School of Nursing and Dental Hygiene, Myron B. Thompson School of Social Work, the Daniel K. Inouye School of Pharmacy and Director of the Office of Public Health Studies in order to help prepare students for working collaboratively in complex healthcare settings. The process through which the curriculum is assess against the Interprofessional Education Collaborative competencies is outlined. In addition to discussing the identified curriculum gaps and plan for action, a detailed curriculum map is provided
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