605 research outputs found

    Spectroscopic imaging techniques for detecting calcification in knee joint tissue

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    Abstract. Osteoarthritis (OA) is the most common form of arthritis that is costly both economically and socially(1). Since OA is irreversible, researchers are constantly seeking the most efficient and reliable method of diagnosing it at an early stage. OA is closely associated with the development of calcifications in soft tissues of the knee joint, such as the meniscus and articular cartilage (AC). These crystal-induced calcifications may represent a potential target for disease-modifying agents in OA treatment. The presence of OA-associated crystals can be also found in the synovial fluid (SF). Among the most common types of crystals found to be associated with OA are basic calcium phosphate (BCP) and calcium phosphate dihydrate (CPPD)(2). Although BCP and CPPD crystals may coexist, their clinical patterns and etiology differ significantly(3). The detection and characterization of OA-related crystals are challenging since they have sub-micron structures, and they can coexist with other crystal deposition disorders like pseudogout or gout. OA-related changes in AC and SF have been extensively studied, in addition, in recent years the meniscus has also been taken into consideration. It has been reported that the meniscus can be calcified even though the AC is not(2). According to these results, meniscal calcification may potentially be a risk factor for cartilage lesions. There are a number of analytical techniques that have been applied to detect and characterize crystals in knee joint tissue, either directly or indirectly. This thesis focuses on different spectroscopic techniques available for detecting calcium crystals in synovial fluid, articular cartilage, and meniscus of the knee joint. Particularly, this thesis aims to systematically review the spectroscopic studies related to the detection of calcification from knee join tissue and presents an experiment that characterizes calcifications in meniscus using Raman spectroscopy

    An RG potential for the quantum Hall effects

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    The phenomenological analysis of fully spin-polarized quantum Hall systems, based on holomorphic modular symmetries of the renormalization group (RG) flow, is generalized to more complicated situations where the spin or other "flavors" of charge carriers are relevant, and where the symmetry is different. We make the simplest possible ansatz for a family of RG potentials that can interpolate between these symmetries. It is parametrized by a single number aa and we show that this suffices to account for almost all scaling data obtained to date. The potential is always symmetric under the main congruence group at level two, and when aa takes certain values this symmetry is enhanced to one of the maximal subgroups of the modular group. We compute the covariant RG β\beta-function, which is a holomorphic vector field derived from the potential, and compare the geometry of this gradient flow with available temperature driven scaling data. The value of aa is determined from experiment by finding the location of a quantum critical point, i.e., an unstable zero of the β\beta-function given by a saddle point of the RG potential. The data are consistent with a∈Ra \in \mathbb{R}, which together with the symmetry leads to a generalized semi-circle law.Comment: 10 figures, sligthly updated discussion and refs, accepted for PR

    The Effect of Forage Legumes on Mineral Nitrogen Content in Soil

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    The cultivation of forage legumes is often suggested as a possibility to improve nitrogen (N) utilisation in farming. However, previous studies have indicated examples in which the cultivation of legumes such as white clover has led to accumulation of large amounts of N in soil (Adams & Pattison, 1985). In this study the potential risks of N leaching were estimated by determining amount of mineral N in the soil

    Local height probabilities in a composite Andrews-Baxter-Forrester model

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    We study the local height probabilities in a composite height model, derived from the restricted solid-on-solid model introduced by Andrews, Baxter and Forrester, and their connection with conformal field theory characters. The obtained conformal field theories also describe the critical behavior of the model at two different critical points. In addition, at criticality, the model is equivalent to a one-dimensional chain of anyons, subject to competing two- and three-body interactions. The anyonic-chain interpretation provided the original motivation to introduce the composite height model, and by obtaining the critical behaviour of the composite height model, the critical behaviour of the anyonic chains is established as well. Depending on the overall sign of the hamiltonian, this critical behaviour is described by a diagonal coset-model, generalizing the minimal models for one sign, and by Fateev-Zamolodchikov parafermions for the other.Comment: 34 pages, 5 figures; v2: expanded introduction, references added and other minor change

    Immune activation in the small intestine in patients with rheumatoid arthritis

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    Objectives: To determine whether inflammation in the gut associated immune system is activated in rheumatoid arthritis ( RA). The expression of chemokine receptor- (CCR4, CCR5) and cytokine- ( interleukin (IL) 2, IL10, interferon gamma (IFNgamma), tumour necrosis factor alpha (TNFalpha), and transforming growth factor beta (TGFbeta)) specific mRNA in intestinal biopsy samples from patients with RA was examined. Methods: Duodenal biopsy samples from 13 patients with RA and 15 control subjects were studied. The mRNA expression of CCR4, CCR5, IL2, IL10, IFNgamma, TNFalpha, and TGFb in intestinal biopsy samples was demonstrated by real time quantitative reverse transcriptase-polymerase chain reaction. Results: The mRNA expression of CCR4, CCR5, and IL10 in intestinal biopsy samples was increased in patients with RA in comparison with control subjects ( p = 0.001, p = 0.046, p = 0.019). No difference in the expression levels of IL2, IFNgamma, TNFalpha, or TGFbeta was seen between patients with RA and controls. Conclusions: The increased intestinal mRNA expression of IL10, CCR5, and CCR4 suggests that gut associated immune cells are activated in patients with RA.Peer reviewe

    Salivary IgA to MAA-LDL and Oral Pathogens Are Linked to Coronary Disease

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    A large body of literature has established the link between periodontal disease and cardiovascular disease. Oxidized low-density lipoproteins (OxLDLs) have a crucial role in atherosclerosis progression through initiation of immunological response. Monoclonal IgM antibodies to malondialdehyde-modified low-density lipoprotein (MDA-LDL) and to malondialdehyde acetaldehyde-modified low-density lipoprotein (MAA-LDL) have been shown to cross-react with the key virulence factors of periodontal pathogens Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. We have previously shown that salivary IgA antibodies to MAA-LDL cross-react with P. gingivalis in healthy humans. In this study, we aim to assess whether oral mucosal immune response represented by salivary IgA to MAA-LDL and oral pathogens is associated with coronary artery disease (CAD). Also, the molecular mimicry through antibody cross-reaction between salivary IgA to MAA-LDL and oral pathogens was evaluated. The study subjects consisted of 451 patients who underwent a coronary angiography with no CAD (n = 133), stable CAD (n = 169), and acute coronary syndrome (ACS, n = 149). Elevated salivary IgA antibody levels to MAA-LDL, Rgp44 (gingipain A hemagglutinin domain of P. gingivalis), and Aa-HSP60 (heat shock protein 60 of A. actinomycetemcomitans) were discovered in stable-CAD and ACS patients when compared to no-CAD patients. In a multinomial regression model adjusted for known cardiovascular risk factors, stable CAD and ACS were associated with IgA to MAA-LDL (P = 0.016, P = 0.043), Rgp44 (P = 0.012, P = 0.004), Aa-HSP60 (P = 0.032, P = 0.030), Tannerella forsythia (P = 0.002, P = 0.004), Porphyromonas endodontalis (P = 0.016, P = 0.020), Prevotella intermedia (P = 0.038, P = 0.005), and with total IgA antibody concentration (P = 0.002, P = 0.016). Salivary IgA to MAA-LDL showed cross-reactivity with the oral pathogens tested in the study patients. The study highlights an association between salivary IgA to MAA-LDL and atherosclerosis. However, whether salivary IgA to MAA-LDL and the related oral humoral responses play a causal role in the development in the CAD should be elucidated in the future.Peer reviewe
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