33 research outputs found

    Ermakov-Lewis symmetry in photonic lattices

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    We present a class of waveguide arrays that is the classical analog of a quantum harmonic oscillator where the mass and frequency depend on the propagation distance. In these photonic lattices refractive indices and second neighbor couplings define the mass and frequency of the analog quantum oscillator, while first neighbor couplings are a free parameter to adjust the model. The quantum model conserves the Ermakov-Lewis invariant, thus the photonic crystal also posses this symmetry.Comment: 8 pages, 3 figure

    Using OWA fuzzy operator to merge retrieval system results

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    With rapid growth of information sources, it is essential to develop methods that retrieve most relevant information according to the user requirements. One way of improving the quality of retrieval is to use more than one retrieval engine and then merge the retrieved results and show a single ranked list to the user. There are studies that suggest combining the results of multiple search engines will improve ranking when these engine are treated as independent experts. In this study, we investigated performance of Persian retrieval by merging four different language modeling methods and two vector space models with Lnu.ltu and Lnc.btc weighting schemes. The experiments were conducted on a large Persian collection of news archives called Hamshari Collection. Different variations of the Ordered Weighted Average (OWA) fuzzy operators method, called a quantifier based OWA operator and a degree-of-importance based OWA operator method have been tested for merging the results. Our experimental results show that the OWA operators produce better precision and ranking in comparison with weaker retrieval methods. But in comparison with stronger retrieval models they only produce minimal improvements

    Bone mineral density status in patients with recent-onset rheumatoid arthritis

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    Background: Osteoporosis is a sizable comorbidity complication in Rheumatoid Arthritis (RA) sufferers. In the current study, the prevalence of osteopenia and osteoporosis in active RA sufferers and the association of disease-related factors of osteoporosis and reduced bone mineral density (BMD) have been examined. Methods: In this cross-sectional study, 300 new-onset symptoms (less than one year) RA patients without a history of glucocorticoids or DMARDs were selected. Biochemical blood measurements and BMD status were performed with dual-energy X-ray absorptiometry. According to the T-scores of the patients, they were divided into three groups: osteoporosis<-2.5, -2.5 < osteopenia <-1, and − 1 < normal. Also, the MDHAQ questionnaire, DAS-28, and FRAX criteria were calculated for all patients. Multivariate logistic regression was used to determine the associated factors of osteoporosis and osteopenia. Results: The Prevalence of osteoporosis and osteopenia was 27% (95%CI:22–32) and 45% (95%CI:39–51), respectively. The multivariate regression analysis showed that age could play a role as an associated factor for spine/hip Osteoporosis and Osteopenia. The female gender is also a predictor of Spine osteopenia Patients with Total hip Osteoporosis were more likely to have higher DAS-28 (OR 1.86, CI 1.16–3.14) and positive CRP (OR 11.42, CI 2.65–63.26). Conclusion: recent-onset RA patients are at risk for osteoporosis and its complications, regardless of using glucocorticoids or DMARDs. Demographic factors (e.g. age and female gender), patients’ MDHAQ scores, and disease-related factors(e.g., DAS-28, positive CRP were associated with reduced BMD levels. Therefore, it is recommended that clinicians investigate early BMD measurements to have a reasonable judgment for further interventions. © 2023, The Author(s), under exclusive licence to Tehran University of Medical Sciences

    Menstrual blood-derived stromal stem cells augment CD4+ T cells proliferation

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    Background: It is more than sixty years that the concept of the fetal allograft and immunological paradox of pregnancy was proposed and in this context, several regulatory networks and mechanisms have been introduced so far. It is now generally recognized that mesenchymal stem cells exert potent immunoregulatory activity. In this study, for the first time, the potential impact of Menstrual blood Stem Cells (MenSCs), as surrogate for endometrial stem cells, on proliferative capacity of CD4+ T cells was tested. Methods: MenSCs and Bone marrow Mesenchymal Stem Cells (BMSCs) were isolated and assessed for their immunophenotypic features and multi-lineage differentiation capability. BMSCs and MenSCs with or without IFNγ pre-stimulation were co-cultured with purified anti-CD3/CD28-activated CD4+ T cells and the extent of T cell proliferation at different MenSCs: T cell ratios were investigated by CSFE flow cytometry. IDO activity of both cell types was measured after stimulation with IFNγ by a colorimetric assay. Results: MenSCs exhibited dual mesenchymal and embryonic markers and multi-lineage differentiation capacity. MenSCs significantly increased proliferation of CD4+ cells at ratios 1:2, 1:4 and 1:8. IFNγ pre-treated BMSCs but not MenSCs significantly suppressed CD4+ T cells proliferation. Such proliferation promoting capacity of MenSCs was not correlated with IDO activity as these cells showed the high IDO activity following IFNγ treatment. Conclusion: Although augmentation of T cell proliferation by MenSCs can be a basis for maintenance of endometrial homeostasis to cope with ascending infections, this may not fulfill the requirement for immunological tolerance to a semi-allogeneic fetus. However, more investigation is needed to examine whether or not the immunomodulatory properties of these cells are affected by endometrial microenvironment during pregnancy. © 2018, Avicenna Journal of Medical Biotechnology. All rights reserved

    HT2008-56478 HEAT TRANSFER ENHANCEMENT IN TRIANGULAR FIN

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    ABSTRACT Fins are widely utilized in many industrial applications for example, fins are used in air cooled finned tube heat exchangers like car radiators, heat rejection devices, refrigeration systems and in condensing central heat exchangers. In this paper, heat transfer inside the fin system composed of a primary rectangular fin with a number of rectangular fins (secondary fins), which are attached on its surface, is modeled and analyzed numerically. The length of the secondary fins decreases linearly from the base of the primary fin to its tip. This modified triangular fin is a kind of improved tree fin networks. The effectiveness of the modified triangular fin is compared with the effectiveness of triangular fin which is calculated analytically. The results show that adding secondary fins increases the effectiveness of triangular fin significantly. Also, it is found that increasing the number of secondary fins in a constant length of primary fin will increase the effectiveness. In addition, by comparing the results it can be concluded that by shortening the length of the primary fin in modified triangular fin, the effectiveness will increase significantly to the contrary of the triangular fin, so smaller heat exchangers can be built by using the modified triangular fin. It is found that in a constant length of primary fin, there is an optimum thickness of secondary fins which maximize the effectiveness of the fin. INTRODUCTION The principle goal in improving the performance of existing thermal systems or in the design of new ones is to enhance heat transfer between hot or cold surfaces and the transport fluid. As such, several methods were proposed in the literature to achieve this task. These methods can be classifie

    Building a Nasa Yuwe Language Test Collection

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    Ermakov-Lewis Symmetry In Photonic Lattices

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    We present a class of waveguide arrays that is the classical analog of a quantum harmonic oscillator, where the mass and frequency depend on the propagation distance. In these photonic lattices, refractive indices and secondneighbor couplings define the mass and frequency of the analog quantum oscillator, while first-neighbor couplings are a free parameter to adjust the model. The quantum model conserves the Ermakov-Lewis invariant, thus the photonic crystal also possesses this symmetry. © 2014 Optical Society of America

    MneSCs exert a supportive role in establishing a pregnancy-friendly microenvironment by inhibiting TH17 polarization

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    Objectives: Uncontrolled TH17 differentiation has been suggested to play a role in the pathogenesis of pregnancy loss. We recently showed that menstrual blood stromal/stem cells (MenSCs) alter functional features of natural killer cells. Here, we hypothesized that MenSCs could modulate differentiation of TH17 cells. Method: MenSCs were collected from 18 apparently healthy women and characterized. Bone marrow mesenchymal stem cells (BMSCs) served as a control. TH17 polarization and proliferation of purified T CD4+ cells were assessed by flow cytometry in a well-defined co-culture system containing T CD4+ cells and MenSCs or BMSCs. Indoleamine 2,3-Dioxygenase (IDO) activity was evaluated in MenSC and BMSC culture supernatants by a colorimetric assay. The impact of MenSCs on expression of transcription factors, RORC, T-bet, Gata3, NRP-1 and Helios were studied by qPCR. Results: MenSCs significantly inhibited TH17 differentiation (p = 0.0383) and percentage of the cells co-expressing IL-17 and IFN-γ (p = 0.0023). PGE2 blockade significantly reduced percentage and proliferation of T CD4+IL-17+ (p = 0.003, p = 0.0018), T CD4+ IFN-γ+ (p = 0.002, p = 0.0022) and T CD4+IL-17+ IFN-γ+ (p = 0.004, p = 0.02) cells. MenSCs produced a considerable activity of IDO (p = 0.0002), induced a significant rise in the Treg frequency (p = 0.0091) and a sharp increase in TH17/Tregs ratio (p = 0.0022). MenSCs increased expression of NRP1 (p = 0.001), while downregulated expression of RORC in T cells (p = 0.001). Conclusion: Our results suggest a supportive role for MenSCs in establishing a pregnancy-friendly microenvironment in the uterus and put forth the idea that inherent abnormalities of MenSCs may be a basis for dysregulated endometrial immune network leading to pregnancy loss. © 2020 Elsevier B.V
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