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Validation study of a portable accelerometer to measure muscular power output : Correlation between the Beast Sensor and the linear encoder MuscleLabBergenblad, Jonas January 2017 (has links)
Abstract Background: The ability to produce a high power output can be the deciding factor in determining which athlete wins or loses in a sporting event. Power output can be measured in an exercise like the squat or bench press. The use of a force plate, or a force plate paired with a linear position transducer is considered the gold standard when measuring power output in an exercise like the squat or bench press. Linear position transducers or linear encoders have also been considered valid methods. Power output can also be measured by accelerometers. Purpose: The purpose of this study was to test the concurrent validity of the accelerometer Beast Sensor by measuring average power in explosive squatting and bench pressing at 40 % and 80 % of one repetition maximum (1RM). The linear encoder MuscleLab was used as criterion. Methods: 17 test subjects, five women and 12 men (average age 28 years) were recruited. Fifteen of the subjects completed two test sessions. The first session determined their 1RM. The second session took place 7-14 days later and measured average power output during two sets of three repetitions at 40 % and 80 % of the subjects 1RM in explosive squats and bench presses. The average power output of the repetitions was measured simultaneously by Beast Sensor and MuscleLab. For the Beast Sensor to be considered valid, a correlation coefficient of 0.9 or higher needed to be reached. Results: Beast Sensor demonstrated high or very high correlations with MuscleLab for average power output of explosive squats at 40 % of 1RM (rs = 0.91), and for explosive bench presses at 40 % (rs = 0.86) and 80 % of 1RM (rs = 0.74). However, for explosive squats at 80 % of 1RM, the correlation was low (rs = 0.42). All correlations were statistically significant with p-values of < 0.01. Beast Sensor was considered valid for squats at 40 % of 1RM, but neither at 80 % of 1RM in squats, nor at 40 % or 80 % of 1RM in bench presses. Conclusion: Beast Sensor showed high or very high correlations with the criterion MuscleLab in three of the four assessed data variables. Only the correlation for average power output of the explosive squats at 40 % of the subject’s 1RM reached the required correlation coefficient of 0.9 or higher for the Beast Sensor to be considered valid. Except for at 40 % of 1RM in squats, Beast Sensor missed a substantial amount of repetitions. Further studies examining the reliability of the Beast Sensor are therefore needed. / Abstrakt Bakgrund: Förmågan att producera hög effektutveckling (power) kan avgöra vilken idrottare som vinner eller förlorar en tävling. Effektutveckling kan mätas i övningar som knäböj och bänkpress. Detta kan göras med hjälp av en kraftplatta, eller en kraftplatta parad med en linear position transducer. Dessa metoder anses vara ”gold standard”, men linear position transducers eller linear encoders har också ansetts vara valida metoder. Effektutveckling kan även mätas med hjälp av en accelerometer. Syfte: Syftet med denna studie var att mäta samtidig validitet hos accelerometern Beast Sensor genom att mäta genomsnittlig effektutveckling i explosiva knäböj och bänkpressar vid 40 % och 80 % av en repetition max (1RM). MuscleLab, en linear encoder, användes som referensvärde. Metod: 17 försökspersoner, fem kvinnor och tolv män (medelålder 28 år) rekryterades. Femton av försökspersonerna fullföljde deltagande. Vid det första testtillfället mättes 1RM. Det andra tillfället ägde rum 7-14 dagar senare och mätte genomsnittlig effektutveckling i explosiva knäböj och bänkpressar vid 40 % och 80 % av försökspersonernas uppmätta 1RM. Två set av tre repetitioner mättes vid 40 % och 80 % av 1RM i både knäböj och bänkpress. Repetitionerna mättes samtidigt av MuscleLab och Beast Sensor. För att Beast Sensor skulle anses vara valid behövde en korrelationskoefficient på 0.9 eller högre uppnås. Resultat: Beast Sensor uppvisade höga eller väldigt höga korrelationer med MuscleLab för genomsnittlig effektutveckling i explosiva knäböj vid 40 % av 1RM (rs = 0.91) och explosiva bänkpressar vid 40 % (rs = 0.86) och 80 % av 1RM (rs = 0.74). Dock uppmättes en låg korrelation för de explosiva knäböjen vid 80 % av 1RM (rs = 0.42). Alla korrelationer var statistiskt signifikanta med p-värden på < 0.01. Beast Sensor ansågs vara valid för att mäta effektutveckling vid 40 % av 1RM i knäböj, men varken vid 80 % av 1RM i knäböj, eller vid 40 % eller 80 % av 1RM i bänkpressar. Slutsats: Beast Sensor visade höga eller väldigt höga korrelationer med referensvärdet från MuscleLab för tre av de fyra uppmätta variablerna. Endast korrelationen för genomsnittlig effektutveckling i explosiva knäböj vid 40 % av 1RM uppnådde den korrelationskoefficient på 0.9 eller högre som krävdes för att Beast Sensor skulle anses vara valid. Förutom vid 40 % av 1RM i knäböj, missade Beast Sensor en väsentlig andel repetitioner. Därför finns det ett behov av fler studier som undersöker reliabiliteten hos Beast Sensor.
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Conception, fabrication et caractérisation de transducteurs ultrasonores multi-éléments en environnements sévères / Ultrasonic transducers arrays for harsh environnementsCadot, Christophe 16 December 2016 (has links)
L’objectif de cette thèse était de concevoir, fabriquer, et tester des transducteurs ultrasonores multi – éléments pour des applications en environnements sévères. Dans ce contexte, des techniques de caractérisation des matériaux ont été développées afin d’adapter la conception des transducteurs en fonction des contraintes de l’environnement, et plus particulièrement la température. Deux types de conceptions ont été étudiées selon les applications visées : La première application consistait à développer un transducteur ultrasonore permettant de réaliser des contrôles non destructifs dans des réacteurs de génération IV (refroidi au sodium liquide) lors d’un arrêt de tranche. Dans ce cas, l’environnement sévère était caractérisé par une température de 200 °C, et la présence de sodium liquide. Des radiations pouvaient également être présentes. Pour cette application, un transducteur (nommé LiNa) sous la forme d’un projecteur ultrasonore linéaire de 20 éléments, fonctionnant à 2.5MHz a été fabriquée, puis testé en eau et en sodium liquide. La seconde application consistait à développer un transducteur ultrasonore permettant de réaliser des contrôles non destructifs en contact de pièces massives en cours de soudage. Une pièce massive est par exemple une cuve de réacteur nucléaire. Ce transducteur permet de détecter des défauts dans une soudure très rapidement après sa réalisation, et ainsi corriger directement cette dernière, sans attendre que les pièces soient refroidies. Pourcette application, un transducteur (nommé MaCo) sous forme de matrice 8 × 8 éléments, fonctionnant à 5MHz a été développé, et caractérisé de la température ambiante, jusqu’à 240 °C. Avec ce capteur, Avec ce capteur, des échos en ondes transversales ont été obtenus jusqu’à la température limite, sans refroidissement. / The goal of this thesis was to design, fabricate and test phased arrays ultrasonic transducers for harshenvironment applications. In this context, characterization methods were developed in order to adapt transducerdesign to the environment. We designed two types of ultrasonic phased array transducers according to theconsidered application:The first application aimed at developping an ultrasonic transducer for non destructive testing in IVth generationnuclear reactors (cooled with liquid sodium) during reactor outages. In this case, the harsh environment wascharacterized by a temperature of 200 °C, and the presence of liquid sodium. Radiations could also be present.For this application, a 20 elements 2.5MHz immersion linear projector (called LiNa) was fabricated then testedunder water and under liquid sodium.The second application aimed at developping an ultrasonic transducer in order to realize non destructive testingin contact with massive pieces during welding. A massive piece for example is a tank for nuclear plant reactor.The transducer will permit to quickly detect defects in a weld after its realization, and then correct it directlyif necessary, without waiting for the pieces to cool down at ambient temperatures. For this application,a 64elements 5MHz matrix transducer (named MaCo) were developed and tested from ambient to 240 °C. Thetransducer worked up to the limit temperature without any cooling system, and some typical defects weredetected.
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Problèmes de bornes pour les automates et les transducteurs à pile visible / Boudedness problems for visibly pushdown automata and transducersCaralp, Mathieu 18 December 2015 (has links)
L’étude des automates est un sujet fondamental de l’informatique. Ce modèle apporte des solutions pratiques à divers problèmes en compilation et en vérification notamment. Dans ce travail nous proposons l'extension aux automates à pile visible de résultats existants pour les automates. Nous proposons une définition d'automate à pile visible émondé et donnons un algorithme s’exécutant en temps polynomial émondant un automate en préservant son langage. Nous donnons aussi un algorithme de complexité exponentielle qui, pour un automate à pile visible donné, construit un automate équivalent à la fois émondé et déterministe. Cette complexité exponentielle se révèle optimale. Étant donné un automate à pile visible, nous pouvons associer à ses transitions des coûts pris dans un semi-anneau S. L’automate associe ainsi un mot d’entrée à un élément de S. Le coût d’un automate est le supremum des coûts associés aux mots d'entrée. Pour les semi-anneaux des entiers naturels et Max-plus, nous donnons des caractérisations et des algorithmes polynomiaux pour décider si le coût d’un automate est fini. Puis, nous étudions pour les entiers naturels la complexité du problème de la majoration du coût par un entier k. Les transducteurs à pile visibles produisent des sorties sur chaque mot accepté. Un problème classique est de décider s'il existe une borne sur le nombre de sorties de chaque mot accepté. Pour une sous-classe des transducteurs à pile visible, nous proposons des propriétés caractérisant les instances positives de ce problème. Nous montrons leur nécessité et discutons d’approches possibles afin de montrer leur suffisance. / The study of automata is a central subject of computer science. This model provides practical solutions to several problems including compilation and verification. In this work we extend existing results of automata to visibly pushdown automata. We give a definition of trimmed visibly pushdown automata and a polynomial time algorithm to trim an automata while preserving its language. We also provide an exponential time algorithm which, given a visibly pushdown automaton, produces an equivalent automaton, both deterministic and trimmed. We prove the optimality of the complexity. Given a visibly pushdown automaton, we can equip its transitions with a cost taken from a semiring S, and thus associate each input word to an element of S. The cost of the automaton is the supremum of the input words cost. For the semiring of natural integers and Max-plus, we give characterisations and polynomial time algorithms to decide if the cost of a visibly pushdown automaton is finite. Then in the case of natural integers we study the complexity of deciding if the cost is bounded by a given integer k. Visibly pushdown transducers produce output on each accepted word. A classical problem is to decide if there exists a bound on the number of outputs of each accepted word. In the case of a subclass of visibly pushdown transducers, we give properties characterizing positive instances of this problem. We show their necessity and discuss of possible approaches to prove their sufficiency.
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Desenvolvimento de um aparelho para teste de força do músculo abdutor curto do polegar e abdutor do quinto dedo da mão / not availableLuciane Fernanda Rodrigues Martinho 30 September 1998 (has links)
A força dos músculos Abdutor curto do polegar (ACP) e Abdutor do quinto dedo (AQD) serve como parâmetro para a avaliação da função dos nervos mediano e ulnar, respectivamente. Um aparelho foi desenvolvido para realizar a medida da força daqueles músculos em mãos de diferentes tamanhos, com a mesma eficiência. Este aparelho foi construído inteiramente com materiais de fácil obtenção e baixo custo, incluindo o aço, o latão, o alumínio e o duralumínio, e consiste de uma base dotada de uma coluna rígida para a fixação de um transdutor de força do tipo resistivo (célula de carga) e de um apoio para a mão para mantê-la firme durante os testes. Acessórios foram construídos segundo medidas antropométricas previamente obtidas nos polegares e quintos dedos voluntários, de modo que pudessem ser acoplados à célula de carga e permitir a avaliação de mãos direitas e esquerdas de diferentes tamanhos. A célula de carga foi calibrada. Quando pronto, o protótipo final foi utilizado para medir a força dos músculos ACP e AQD de 42 voluntários, sendo 20 mulheres e 22 homens, cujo critério de inclusão era a total ausência de qualquer patologia nos membros superiores. Dois pontos de aplicação da carga foram selecionados, sendo um proximal, no nível da falange proximal, e outro distal, no nível da falange distal. Três medidas eram tomadas para cada ponto de aplicação da carga, para cada um dos músculos, e uma média foi obtida para uso na análise estatística dos resultados, que mostraram que a força de ambos os músculos era consistentemente maior nos homens e na mão direita. Quanto aos dois pontos de aplicação da carga, a força foi sempre maior no ponto proximal, tanto para o polegar, como para o quinto dedo. A avaliação geral do desempenho do aparelho mostrou que ele é versátil, fornecendo informações confiáveis para as mãos direitas e esquerdas de todos os tamanhos. / The strength of the Abductor pollicis brevis and Abductor digiti quinti muscles may serve as a parameter to the evaluation of the median and ulnar nerve function, respectively. A device was developed especially for carrying out measurements of the strength of those muscles in hands of different sizes with the same efficiency. The device was built entirely with easily obtained low cost materials, including steel, solid brass, aluminium and duralumin, and consists of a metal base provided with a rigid colunm for fixation of a resistive type strength transducer (load cell) and a hand stand to keep the hand still while in test. Accessories were built according to a previous anthropometric measurement of both thumb and fifth fingers of volunteers, so as to be coupled onto the load cell and allow for the evaluation of the strength of different size hands. The load cell was calibrated. Once ready, the final prototype was used to measure the strength of the APB and AbDQ muscles in 42 volunteers, being 20 women and 22 men, whose inclusion criterion was the total absence of any pathology in the upper limbs. Two points of load application were selected, being one proximal, at the level of the proximal phalanx, and another one distal, at the level of the distal phalanx. Three measurements were taken for each point of load application for both muscles, an average value being obtained for use in the statistical analysis of the results, which showed that the strength was consistantly greater in men and in the right hand. As refers to the different points of load application, the strength was always greater at the proximal point, both for the thumb and the fifth finger. The overall evaluation of performance of the prototype showed that it is versatile, supplying reliable information for all size hands.
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Multifunctional Soft Materials: Design, Development and ApplicationsJanuary 2020 (has links)
abstract: Soft materials are matters that can easily deform from their original shapes and structures under thermal or mechanical stresses, and they range across various groups of materials including liquids, foams, gels, colloids, polymers, and biological substances. Although soft materials already have numerous applications with each of their unique characteristics, integrating materials to achieve complementary functionalities is still a growing need for designing advanced applications of complex requirements. This dissertation explores a unique approach of utilizing intermolecular interactions to accomplish not only the multifunctionality from combined materials but also their tailored properties designed for specific tasks. In this work, multifunctional soft materials are explored in two particular directions, ionic liquids (ILs)-based mixtures and interpenetrating polymer network (IPN).
First, ILs-based mixtures were studied to develop liquid electrolytes for molecular electronic transducers (MET) in planetary exploration. For space missions, it is challenging to operate any liquid electrolytes in an extremely low-temperature environment. By tuning intermolecular interactions, the results demonstrated a facile method that has successfully overcome the thermal and transport barriers of ILs-based mixtures at extremely low temperatures. Incorporation of both aqueous and organic solvents in ILs-based electrolyte systems with varying types of intermolecular interactions are investigated, respectively, to yield optimized material properties supporting not only MET sensors but also other electrochemical devices with iodide/triiodide redox couple targeting low temperatures.
Second, an environmentally responsive hydrogel was synthesized via interpenetrating two crosslinked polymer networks. The intermolecular interactions facilitated by such an IPN structure enables not only an upper critical solution temperature (UCST) transition but also a mechanical enhancement of the hydrogel. The incorporation of functional units validates a positive swelling response to visible light and also further improves the mechanical properties. This studied IPN system can serve as a promising route in developing “smart” hydrogels utilizing visible light as a simple, inexpensive, and remotely controllable stimulus.
Over two directions across from ILs to polymeric networks, this work demonstrates an effective strategy of utilizing intermolecular interactions to not only develop multifunctional soft materials for advanced applications but also discover new properties beyond their original boundaries. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2020
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Raspberry Pi Based IoT System for Bats Detection at Wind FarmsKaruturi, Hemanth Surya, Karri, Megha Sanjeev Reddy January 2020 (has links)
Context: Large numbers of bats are killed by collisions with wind turbines and there is at present no accepted method of reducing or preventing this mortality. We designed a system, which detects and records any bats’ activity in and around the surroundings of wind turbines. The system can help to study bats by identifying the species that are present in that particular locality. Objectives: The main objective of this thesis is to design an ultrasound-based IoT system, which detects the bats to prevent them from clashing with wind turbines. The design is based on a study of bats’ behaviors. Methods: The system has been developed using User-Driven Design, UDD, approach. The required functionalities have been embedded into IoT based system. An ultrasonic technology along with other sensors are used. The sensors are intended to activate monitoring during favorable conditions for bat activity. Results: A model of a system has been developed. The model was implemented into a prototype. Recorded bats’ activities are uploaded to a server by employing a suitable app, which informs the user about the activities of bats' various sub-species. Conclusions: A surveillance for bats approaching the wind farms within 80 m has been developed. The monitoring system is activated when the weather conditions are favorable for bat activities.
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Decline of miR-124 in Myeloid Cells Promotes Regulatory T-cell Development in Hepatitis C Virus InfectionRen, Jun P., Wang, Lin, Zhao, Juan, Wang, Ling, Ning, Shun B., El Gazzar, Mohamed, Moorman, Jonathan P., Yao, Zhi Q. 18 October 2016 (has links)
Myeloid‐derived suppressor cells (MDSC s) and microRNA s (miRNA s) contribute to attenuating immune responses during chronic viral infection; however, the precise mechanisms underlying their suppressive activities remain incompletely understood. We have recently shown marked expansion of MDSC s that promote regulatory T (Treg) cell development in patients with chronic hepatitis C virus (HCV ) infection. Here we further investigated whether the HCV ‐induced expansion of MDSC s and Treg cells is regulated by an miRNA ‐mediated mechanism. The RNA array analysis revealed that six miRNA s were up‐regulated and six miRNA s were down‐regulated significantly in myeloid cells during HCV infection. Real‐time RT ‐PCR confirmed the down‐regulation of miR‐124 in MDSC s from HCV patients. Bioinformatic analysis suggested that miR‐124 may be involved in the regulation of signal transducer and activator of transcription 3 (STAT ‐3), which was overexpressed in MDSC s from HCV patients. Notably, silencing of STAT ‐3 significantly increased the miR‐124 expression, whereas reconstituting miR‐124 decreased the levels of STAT ‐3, as well as interleukin‐10 and transforming growth factor‐β , which were overexpressed in MDCS s, and reduced the frequencies of Foxp3+ Treg cells that were developed during chronic HCV infection. These results suggest that reciprocal regulation of miR‐124 and STAT ‐3 in MDSC s promotes Treg cell development, thus uncovering a novel mechanism for the expansion of MDSC and Treg cells during HCV infection.
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Expansion of Myeloid-Derived Suppressor Cells Promotes Differentiation of Regulatory T Cells in HIV-1+ IndividualsWang, Ling, Zhao, Juan, Ren, Junping P., Wu, Xiao Y., Morrison, Zheng D., El Gazzar, Mohamed A., Ning, Shunbin, Moorman, Jonathan P., Yao, Zhi Q. 19 June 2016 (has links) (PDF)
Objective: Regulatory T cells (Tregs) contribute to HIV-1 disease progression by impairing antiviral immunity; however, the precise mechanisms responsible for the development of Tregs in the setting of HIV-1 infection are incompletely understood.
Design: In this study, we provide evidence that HIV-induced expansion of monocytic myeloid-derived suppressor cells (M-MDSCs) promote the differentiation of Foxp3+ Tregs.
Methods: We measured MDSC induction and cytokine expression by flow cytometry and analyzed their functions by coculturing experiments.
Results: We observed a dramatic increase in M-MDSC frequencies in the peripheral blood of HIV-1 seropositive (HIV-1+) individuals, even in those on antiretroviral therapy with undetectable viremia, when compared with healthy participants. We also observed increases in M-MDSCs after incubating healthy peripheral mononuclear cells (PBMCs) with HIV-1 proteins (gp120 or Tat) or Toll-like receptor 4 ligand lipopolysaccharides in vitro, an effect that could be abrogated in the presence of the phosphorylated signal transducer and activator of transcription 3 inhibitor, STA-21. Functional analyses indicated that M-MDSCs from HIV-1+ individuals express higher levels of IL-10, tumor growth factor-β, IL-4 receptor α, p47phex, programmed death-ligand 1, and phosphorylated signal transducer and activator of transcription 3 – all of which are known mediators of myelopoiesis and immunosuppression. Importantly, incubation of healthy CD4+ T cells with MDSCs derived from HIV-1+ individuals significantly increased differentiation of Foxp3+ Tregs. In addition, depletion of MDSCs from PBMCs of HIV-1+ individuals led to a significant reduction of Foxp3+ Tregs and increase of IFNγ production by CD4+ T effector cells.
Conclusions: These results suggest that HIV-induced MDSCs promote Treg cell development and inhibit T cell function – a hallmark of many chronic infectious diseases.
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Development of a novel cell traction force transducer based on cholesteryl ester liquid crystals. Characterisation, quantification and evaluation of a cholesteryl ester liquid crystal based single cell force transducer system.Soon, Chin Fhong January 2011 (has links)
In biomechano-transducing, cellular generated tension can be measured by soft substrates based on polymers but these techniques are limited either by spatial resolution or ability to detect localised cell traction forces (CTF) due to their non-linear viscous behaviour under shear rates. A newly developed cell traction force transducer system based on cholesteryl ester lyotropic liquid crystals (LCTFT) was developed to sense localised traction forces of human keratinocyte cell lines (HaCaTs), in which the length of the deformation line induced represents the intensity of the CTF exerted. The physical properties of the cholesteryl ester based lyotropic liquid crystals (LLC) were characterised by using polarising microscopy, rheology, atomic force microscopy (AFM) based nano-indentation, spherical indentation, and micro-tensile tests. The interactions of LLC with cells were studied by using cell viability studies, cytochemical treatments, widefield surface plasmon resonance (WSPR) microscopy and various immuno-staining techniques. The results show that LLC is thermally stable (0 - 50 oC) and linearly viscoelastic below 10 % shear strain at shear rates of < 1 s-1. AFM nano and spherical indentations show a good agreement on the Young¿s modulus of both determined at ~110 kPa which is close to the elastic modulus of the epidermis. The Poisson¿s ratio of LLC was determined at ~0.58 by using micro tensile tests. The biophysical interaction studies indicated that LLC is biocompatible and allowed cell attachment. Cell relaxation technique by cytochalasin-B treatment suggested that the attachment and contraction of cells on LLC was due to the contractile activity of actin cytoskeletons that are mediated by focal adhesions. The staining experiments showed that cells consistently expressed the same suites of integrins (¿2, ¿3, ¿5 and ¿1) and ECM proteins (collagen type IV, laminin and fibronectin) on both glass and LLC coated substrates. Interfacial interaction of cells with LLC observed via the staining of actin and vinculin, and WSPR imaging suggest the association of marginal actin filaments and focal adhesions in attaching HaCaT cells to the LLC. Linear static analysis applied in the Finite Element model of focal adhesion-LC confirmed the compressive force patterns induced by cells. By applying cell relaxation techniques and Hooke¿s theorem, the force-deformation relationships of the LLC were derived and used for direct quantification of CTF in culture. The sensitivity of the LCTFT was implied by a wide range of CTF (10 - 140 nN) measured at high resolutions (~2 ¿m). Nonetheless, a custom-built cell traction force measurement and mapping software (CTFM) was developed to map CTF of single cells. Reliability of the LCTFT was evaluated by using a known pharmacological active cytokine, TGF-¿1, in inducing contraction of human keratinocytes. This study inferred internal consistency and repeatability of the LCTFT in sensing contraction responses of HaCaT cells in a concentration dependent manner of TGF-¿1. The overall LCTFT and CTFM software had shown good potential for use in the study of contraction and migration of keratinocytes. / Malaysia Ministry of Higher Education
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The Effect of STAT5 on Inflammation-Related Gene Expression in Diabetic Mouse KidneysShaw, Samantha J. 12 June 2014 (has links)
No description available.
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