1,723,161 research outputs found
Translational studies on mitochondrial function and hypoxia in complications of diabetes mellitus
No full textDiabetes Mellitus (DM) is a major concern for societies and healthcare systems globally. DM-associated morbidity and mortality is mediated by diabetic complications. Hypoxia and oxidative stress have emerged as key players in the pathogenesis of various macro- and microvascular complications of DM. This work aimed to investigate different aspects of the relationship between hypoxia, regulation of hypoxia inducible factor-1 (HIF-1), mitochondrial function and the development of common DM complications from a translational perspective.Paper I investigates the endogenous antioxidant Coenzyme Q10 in a Swedish cohort of DM patients. We explored the association between markers of oxidative stress and the prevalence of vascular complications of DM. Our results showed hyperlipidemia, hyperglycemia, and inflammation to be associated with markers of oxidative stress, which in turn was correlated to the prevalence of diabetes complications such as peripheral neuropathy. In Paper II, we investigated a novel epoxidated Tocotrienol derivative exhibiting antioxidative properties affecting mitochondrial function. Mono-epoxy-tocotrienol-alpha was seen to stimulate pro-wound healing processes such as fibroblast migration rates and endothelial tube formation in vitro. The compound was also shown to increase wound closure rates in diabetic mice. This paper demonstrated experimentally that modulating mitochondrial function can improve factors underlying deficient wound healing in DM. The association between hypoxia regulation, wound healing and cellular bioenergetics in DM was studied in Paper III. HypoxamiR-210 (miR-210) is induced by HIF-1 in response to hypoxia. We found that hyperglycaemia reduced hypoxia-dependent miR-210 induction. miR- 210 increased the rate of wound healing in diabetic mice. The same treatment reduced oxygen consumption rate and ROS production in wound tissue. We thus showed that the hypoxia associated dysregulation in wound healing can be reversed through miR-210-mediated improvement of cellular metabolism. Finally, Paper IV explored the relationship between HIF-1 repression by hyperglycemia and overproduction of ROS in DM. Using a translational approach employing cell cultures, mice and human subjects exposed to hypoxic conditions, we showed that HIF-1-deficient induction of ROS production is specific feature in DM. Reversing this process was shown to be a protective factor against diabetic nephropathy. Hence, reversing impaired HIF-1 function is a potential therapeutic target in the treatment of DM complications.List of scientific papersI. Elisabete Forsberg*, Cheng Xu*, Jacob Grünler, Johan Frostegård, Michael Tekle, Kerstin Brismar, Lars Kärvestedt. Coenzyme Q10 and oxidative stress, the association with peripheral sensory neuropathy and cardiovascular disease in type 2 diabetes mellitus. J Diabetes Compliations. Nov-Dec 2015;29(8):1152-8. *Shared first authorship. https://doi.org/10.1016/j.jdiacomp.2015.08.006 II. Cheng Xu, Magnus Bentinger, Octavian Savu, Ali Mosfegh, Vivekananda Sunkari, Gustav Dallner, Ewa Swiezewska, Sergiu-Bogdan Catrina, Kerstin Brismar, Michael Tekle. Mono-epoxy-tocotrienol-alpha enhances wound healing in diabetic mice and stimulates in vitro angiogenesis and cell migration. J Diabetes Complications. 2017 Jan;31(1):4-12. https://doi.org/10.1016/j.jdiacomp.2016.10.010 III. Sampath Narayanan, Sofie Eliasson, Cheng Xu, Jacob Grünler, Allan Zhao, Wan Zhu, Ning Xu Landén, Mona Ståhle, Jingping Zhang, Mircea Ivan, Raluca Georgiana Maltesen, Ileana Ruxandra Botusan, Neda Rajamand Ekberg, Xiaowei Zheng, Sergiu-Bogdan Catrina. HypoxamiR-210 accelerates wound healing in diabetes by improving cellular metabolism. Comms Bio. [Accepted] https://doi.org/10.1038/s42003-020-01495-y IV. Xiaowei Zheng*, Sampath Narayanan*, Cheng Xu*, Sofie Eliasson, Jacob Grünler, Allan Zhao, Alessandro di Torro, Luciano Bernardi, Massimiliano Massone, Peter Carmeliet, Marianna del Sole, Giancarlo Solaini, Kerstin Brismar, Tomas A. Schiffer, Ileana Ruxandra Botusan, Neda Rajamand Ekberg, Fredrik Palm, Sergiu-Bogdan Catrina. Repression of Hypoxia inducible Factor 1 (HIF-1) in diabetes contributes to the increase of mitochondrial radical oxygen species (ROS) production. *Shared first authorship. [Manuscript]</p
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Qiang guan lian xi tong zhong de chang cheng xu
No full textLong range order (LRO) is one of the most important properties of physics systems, especially for a strongly correlated system. In this thesis, the long range order in a few strongly correlated systems is investigated both rigorously and numerically.Magnetic orders in the two-dimensional periodic Anderson model (PAM) were investigated in the project. Several numerical methods including exact diagonalization, mean field methods and the constrained path Monte Carlo (CPMC) method were used here. We studied the effect of the dispersion of the impurity band on the magnetism and gave estimated phase diagrams on the band filling and impurity chemical potential plane, by comparing the ground state energies and by studying the Fourier transformation of the spin-spin correlations.The Neel long range order in various quantum spin models was studied. A spatially anisotropy antiferromagnetic Heisenberg system was studied and a critical point Jup⊥S was obtained. When J⊥ is larger than Jup⊥S , the Neel long range order was proved to exist in the ground state of the system. Then an onsite single-ion anisotropy D-term was imposed on the above system and its effect on the existence of the long range order was studied. We obtained a critical line on the DJ⊥ plane such that above which the long range order exists. To get insight into the long range order in the two-dimensional isotropic Heisenberg model, the XXZ model and the Heisenberg system with next nearest neighbors interaction were studied. For the XXZ model, two critical couplings DeltaXY and DeltaIsing were obtained such that when 0 ≤ Delta ≤XY or Delta ≥ DeltaIsing, the Neel order appears. For the antiferromagnetic Heisenberg model with next nearest neighbors interaction both spin S = 1/2 and S = 1 were studied. For S = 1/2, a critical next nearest neighbors ferro-coupling Jc2 was obtained such that when J2 ≤ Jc2 , the Neel long range order appears, while for S = 1 an improved Jc2 was obtained such that when J2 ≤ Jc2 the Neel order still exists even with frustration.Wang Yongqiang = 强关联系统中的长程序 / 王永强."June 2005."Adviser: Haiqing Lin.Source: Dissertation Abstracts International, Volume: 67-07, Section: B, page: 3861.Thesis (Ph.D.)--Chinese University of Hong Kong, 2005.Includes bibliographical references (p. 156-162).Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Electronic reproduction. [Ann Arbor, MI] : ProQuest Information and Learning, [200-] System requirements: Adobe Acrobat Reader. Available via World Wide Web.Text in English; abstracts in English and Chinese.School code: 1307.Wang Yongqiang = Qiang guan lian xi tong zhong de chang cheng xu / Wang Yongqiang
sj-pdf-1-imr-10.1177_03000605231198742 - Supplemental material for Plasma exchange for anti-MDA5 antibody-positive dermatomyositis-associated rapidly progressive interstitial lung disease: A case report and literature review
No full textSupplemental material, sj-pdf-1-imr-10.1177_03000605231198742 for Plasma exchange for anti-MDA5 antibody-positive dermatomyositis-associated rapidly progressive interstitial lung disease: A case report and literature review by Ci Lu, Cheng Xu, Xiaoying Zhu and Yongmei Han in Journal of International Medical Research</p
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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