1,649 research outputs found

    Long-term clinical and radiographic results of acl reconstruction. Retrospective comparison between three techniques (hamstrings autograft, hamstrings autograft with extra-articular reconstruction, bone patellar tendon autograft)

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    Background. There is no consensus in the current literature on which surgical options render the best long-term results after ACL reconstruction in terms of clinical outcomes and development of radiographic osteoarthritis (AO). The aim of this study is to investigate clinical and radiological results at long-term follow up after ACL reconstruction using hamstring tendons autograft (Group HT), hamstrings autograft with extra-articular reconstruction (Group HT-ER), and bone patellar tendon bone autograft (Group BPTB). Methods. All patients were evaluated at final follow-up using Lysholm, Internation- al Knee Documentation Committee (IKDC), and Tegner scores. An arthrometric KT-1000 evaluation was also done. Comparative weight bearing radiographs were taken, including a skyline view for patellofemoral joint and analyzed according to Fair- bank, Kellgren, and IKDC classification. Sixty patients were selected for this retrospective study, 20 for each group. The mini- mum final follow-up was 10 years for each group. All patients were male and involved in sport activities (Tegner pre-injury >7). Results. Subjective scores improved significantly in all groups, with no significative differences between groups (P<0,05). The number of patients classified as C or D at the IKDC objective activity score was higher in Group HT (2/20, 10%), than in Group BTB (1/20, 5%) and Group HT-E (0/20, 0%). In term of failure-rate, there were no difference between the three groups (P<0,05). Radiologic evaluation shoved more arthritic changes in Group-BT in the patello-fem- oral joint (PMJ). Conclusions. All the three techniques showed satisfactory results at long term follow up with no differences in term of subjective scores. Finally, there was a statistically significant higher incidence of arthritic changes in PFJ as evaluated with x-ray in the BPTP group respect to HT and HT + ER groups (p<0.05)

    Urban Heat Island (UHI) risk maps as innovative tool for urban regeneration strategies. The case of Parma

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    For the purposes of regeneration of the consolidated city it is increasingly important to have the knowledge of the micro-scale distribution of the vulnerability of the population to the consequences of climate change and increasing urbanization. The work to be presented starts with the creation of maps of the risk classification induced by the heat islands in the city of Parma, and aims to investigate which are the most effective strategies that a Public Administration can adopt. The maps that have been created allow to assess the risk for the fragile population at the level of the single building. They relate the climatic datum of thermal variation with the population residing within each building, and verify the causal relationship with the soil sealing and with the morphology of the urban fabric. The results of the study can help to identify the thermal hot spot, receivers of specific mitigation actions. The risk map is itself a tool to develop multilevel actions, designed according to the peculiarities of the sites, where the possible adaptive solutions are compared with the physical and morphological characteristics of the places. The positive function of green infrastructures (contrast of overheating, flood mitigation, creation of places and services with a recreational function) is acquired by research and urban planning practice. It is equally well known the difficulty faced by Local Authorities in the maintenance and increase of unbuilt public areas, fundamental for the connection of ecological networks

    Genetic diversity of wild-type measles viruses: implications for global measles elimination programs.

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    Wild-type measles viruses have been divided into distinct genetic groups according to the nucleotide sequences of their hemagglutinin and nucleoprotein genes. Most genetic groups have worldwide distribution; however, at least two of the groups appear to have a more limited circulation. To monitor the transmission pathways of measles virus, we observed the geographic distribution of genetic groups, as well as changes in them in a particular region over time. We found evidence of interruption of indigenous transmission of measles in the United States after 1993 and identified the sources of imported virus associated with cases and outbreaks after 1993. The pattern of measles genetic groups provided a means to describe measles outbreaks and assess the extent of virus circulation in a given area. We expect that molecular epidemiologic studies will become a powerful tool for evaluating strategies to control, eliminate, and eventually eradicate measles

    Efficient Quantum Tensor Product Expanders and k-designs

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    Quantum expanders are a quantum analogue of expanders, and k-tensor product expanders are a generalisation to graphs that randomise k correlated walkers. Here we give an efficient construction of constant-degree, constant-gap quantum k-tensor product expanders. The key ingredients are an efficient classical tensor product expander and the quantum Fourier transform. Our construction works whenever k=O(n/log n), where n is the number of qubits. An immediate corollary of this result is an efficient construction of an approximate unitary k-design, which is a quantum analogue of an approximate k-wise independent function, on n qubits for any k=O(n/log n). Previously, no efficient constructions were known for k>2, while state designs, of which unitary designs are a generalisation, were constructed efficiently in [Ambainis, Emerson 2007].Comment: 16 pages, typo in references fixe

    Time-ordering and a generalized Magnus expansion

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    Both the classical time-ordering and the Magnus expansion are well-known in the context of linear initial value problems. Motivated by the noncommutativity between time-ordering and time derivation, and related problems raised recently in statistical physics, we introduce a generalization of the Magnus expansion. Whereas the classical expansion computes the logarithm of the evolution operator of a linear differential equation, our generalization addresses the same problem, including however directly a non-trivial initial condition. As a by-product we recover a variant of the time ordering operation, known as T*-ordering. Eventually, placing our results in the general context of Rota-Baxter algebras permits us to present them in a more natural algebraic setting. It encompasses, for example, the case where one considers linear difference equations instead of linear differential equations

    Chronic Endometritis in Subfertile Mares With Presence of Chlamydial DNA

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    When endometritis becomes chronic in mares, infertility can follow. Among various causative agents, many bacteria are involved, and mono- or mixed-infections are common. In our study, 50 mares with a previous history of subfertility were subjected to clinical and ultrasonographic examination of the reproductive tract, and samples were collected for cytology, histology, bacteriology, and polymerase chain reaction for Chlamydia spp detection. The aim of this work was to highlight the presence of Chlamydia abortus in chronic endometritis of subfertile mares. Endometrial chronic lesions were detected in five of six Chlamydia-positive animals

    Phenotypically Heterogeneous Podoplanin-expressing Cell Populations Are Associated with the Lymphatic Vessel Growth and Fibrogenic Responses in the Acutely and Chronically Infarcted Myocardium

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    Cardiac lymphatic vasculature undergoes substantial expansion in response to myocardial infarction (MI). However, there is limited information on the cellular mechanisms mediating post-MI lymphangiogenesis and accompanying fibrosis in the infarcted adult heart. Using a mouse model of permanent coronary artery ligation, we examined spatiotemporal changes in the expression of lymphendothelial and mesenchymal markers in the acutely and chronically infarcted myocardium. We found that at the time of wound granulation, a three-fold increase in the frequency of podoplanin-labeled cells occurred in the infarcted hearts compared to non-operated and sham-operated counterparts. Podoplanin immunoreactivity detected LYVE-1-positive lymphatic vessels, as well as masses of LYVE-1-negative cells dispersed between myocytes, predominantly in the vicinity of the infarcted region. Podoplanin-carrying populations displayed a mesenchymal progenitor marker PDGFRalpha, and intermittently expressed Prox-1, a master regulator of the lymphatic endothelial fate. At the stages of scar formation and maturation, concomitantly with the enlargement of lymphatic network in the injured myocardium, the podoplanin-rich LYVE-1-negative multicellular assemblies were apparent in the fibrotic area, aligned with extracellular matrix deposits, or located in immediate proximity to activated blood vessels with high VEGFR-2 content. Of note, these podoplanin-containing cells acquired the expression of PDGFRbeta or a hematoendothelial epitope CD34. Although Prox-1 labeling was abundant in the area affected by MI, the podoplanin-presenting cells were not consistently Prox-1-positive. The concordance of podoplanin with VEGFR-3 similarly varied. Thus, our data reveal previously unknown phenotypic and structural heterogeneity within the podoplanin-positive cell compartment in the infarcted heart, and suggest an alternate ability of podoplanin-presenting cardiac cells to generate lymphatic endothelium and pro-fibrotic cells, contributing to scar development

    Phenotypically Heterogeneous Podoplanin-expressing Cell Populations Are Associated with the Lymphatic Vessel Growth and Fibrogenic Responses in the Acutely and Chronically Infarcted Myocardium

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    Cardiac lymphatic vasculature undergoes substantial expansion in response to myocardial infarction (MI). However, there is limited information on the cellular mechanisms mediating post-MI lymphangiogenesis and accompanying fibrosis in the infarcted adult heart. Using a mouse model of permanent coronary artery ligation, we examined spatiotemporal changes in the expression of lymphendothelial and mesenchymal markers in the acutely and chronically infarcted myocardium. We found that at the time of wound granulation, a three-fold increase in the frequency of podoplanin-labeled cells occurred in the infarcted hearts compared to non-operated and sham-operated counterparts. Podoplanin immunoreactivity detected LYVE-1-positive lymphatic vessels, as well as masses of LYVE-1-negative cells dispersed between myocytes, predominantly in the vicinity of the infarcted region. Podoplanin-carrying populations displayed a mesenchymal progenitor marker PDGFRalpha, and intermittently expressed Prox-1, a master regulator of the lymphatic endothelial fate. At the stages of scar formation and maturation, concomitantly with the enlargement of lymphatic network in the injured myocardium, the podoplanin-rich LYVE-1-negative multicellular assemblies were apparent in the fibrotic area, aligned with extracellular matrix deposits, or located in immediate proximity to activated blood vessels with high VEGFR-2 content. Of note, these podoplanin-containing cells acquired the expression of PDGFRbeta or a hematoendothelial epitope CD34. Although Prox-1 labeling was abundant in the area affected by MI, the podoplanin-presenting cells were not consistently Prox-1-positive. The concordance of podoplanin with VEGFR-3 similarly varied. Thus, our data reveal previously unknown phenotypic and structural heterogeneity within the podoplanin-positive cell compartment in the infarcted heart, and suggest an alternate ability of podoplanin-presenting cardiac cells to generate lymphatic endothelium and pro-fibrotic cells, contributing to scar development

    Spitzer's Identity and the Algebraic Birkhoff Decomposition in pQFT

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    In this article we continue to explore the notion of Rota-Baxter algebras in the context of the Hopf algebraic approach to renormalization theory in perturbative quantum field theory. We show in very simple algebraic terms that the solutions of the recursively defined formulae for the Birkhoff factorization of regularized Hopf algebra characters, i.e. Feynman rules, naturally give a non-commutative generalization of the well-known Spitzer's identity. The underlying abstract algebraic structure is analyzed in terms of complete filtered Rota-Baxter algebras.Comment: 19 pages, 2 figure
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