965 resultados para zirconia stabilization


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Hepatitis C virus (HCV) infection induces a state of oxidative stress by affecting mitochondrial-respiratory-chain activity. By using cell lines inducibly expressing different HCV constructs, we showed previously that viral-protein expression leads to severe impairment of mitochondrial oxidative phosphorylation and to major reliance on nonoxidative glucose metabolism. However, the bioenergetic competence of the induced cells was not compromised, indicating an efficient prosurvival adaptive response. Here, we show that HCV protein expression activates hypoxia-inducible factor 1 (HIF-1) by normoxic stabilization of its alpha subunit. In consequence, expression of HIF-controlled genes, including those coding for glycolytic enzymes, was significantly upregulated. Similar expression of HIF-controlled genes was observed in cell lines inducibly expressing subgenomic HCV constructs encoding either structural or nonstructural viral proteins. Stabilization and transcriptional activation of HIF-1alpha was confirmed in Huh-7.5 cells harboring cell culture-derived infectious HCV and in liver biopsy specimens from patients with chronic hepatitis C. The HCV-related HIF-1alpha stabilization was insensitive to antioxidant treatment. Mimicking an impairment of mitochondrial oxidative phosphorylation by treatment of inducible cell lines with oligomycin resulted in stabilization of HIF-1alpha. Similar results were obtained by treatment with pyruvate, indicating that accumulation of intermediate metabolites is sufficient to stabilize HIF-1alpha. These observations provide new insights into the pathogenesis of chronic hepatitis C and, possibly, the HCV-related development of hepatocellular carcinoma.

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Background: Adenovirus serotype 5 (Ad5) phase IIb vaccine trial (STEP) was prematurely stopped due to a lack of efficacy and two-fold higher incidence of HIV infection among Ad5 seropositive vaccine recipients. We have recently demonstrated that Ad5 immune complexes (Ad5 ICs)-mediated activation of the dendritic cell (DC)-T cell axis was associated with the enhancement of HIV infection in vitro. Although the direct role of Ad5 neutralizing antibodies (NAbs) in the increase of HIV susceptibility during the STEP trial is still under debate, vector-specific NAbs remain a major hurdle for vector-based gene therapies or vaccine strategies. To surmount this obstacle, vectors based on ''rare'' Ad serotypes including Ad6, Ad26, Ad36 and Ad41 were engineered.Methods: The present study aimed to determine whether Ad ICmediated DC maturation could be circumvented using these Advector candidates.Results: We found that all Ad vectors tested forming ICs with plasma containing serotype-specific NAbs had the capacity to 1) mature human DCs as monitored by the up-regulation of costimulatory molecules and the release of pro-inflammatory cytokines (TNF-a), via the stabilization of Ad capsid at endosomal but not lysosomal pH rendering Ad DNA/TLR9 interactions possible and 2) potentiate Ad-specific CD4 and CD8 T cell responses.Conclusion: In conclusion, despite a conserved DC maturation potential, the low prevalence of serotype-specific NAbs renders rare Ad vectors attractive for vaccine strategies.

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Hypertension is associated with increased risk of cardiovascular diseases. Antihypertensive treatment, particularly blockade of the renin-angiotensin system, contributes to prevent atherosclerosis-mediated cardiovascular events. Direct comparison of different antihypertensive treatments on atherosclerosis and particularly plaque stabilization is sparse. ApoE(-/-) mice with vulnerable (2-kidney, 1-clip renovascular hypertension model) or stable (1-kidney, 1-clip renovascular hypertension model) atherosclerotic plaques were used. Mice were treated with aliskiren (renin inhibitor), irbesartan (angiotensin-receptor blocker), atenolol (beta-blocker), or amlodipine (calcium channel blocker). Atherosclerosis characteristics were assessed. Hemodynamic and hormonal parameters were measured. Aliskiren and irbesartan significantly prevented atherosclerosis progression in 2-kidney, 1-clip mice. Indeed, compared with untreated animals, plaques showed thinner fibrous cap (P<0.05); smaller lipid core (P<0.05); decreased media degeneration, layering, and macrophage content (P<0.05); and increased smooth muscle cell content (P<0.05). Interestingly, aliskiren significantly increased the smooth muscle cell compared with irbesartan. Despite similar blood pressure lowering, only partial plaque stabilization was attained by atenolol and amlodipine. Amlodipine increased plaque smooth muscle cell content (P<0.05), whereas atenolol decreased plaque inflammation (P<0.05). This divergent effect was also observed in 1-kidney, 1-clip mice. Normalizing blood pressure by irbesartan increased the plasma renin concentration (5932+/-1512 ng/mL per hour) more than normalizing it by aliskiren (16085+/-5628 ng/mL per hour). Specific renin-angiotensin system blockade prevents atherosclerosis progression. First, evidence is provided that direct renin inhibition mediates atherosclerotic plaque stabilization. In contrast, beta-blocker and calcium channel blocker treatment only partially stabilize plaques differently influencing atherogenesis. Angiotensin II decisively mediates plaque vulnerability. The plasma renin concentration measurement by an indirect method did not confirm the excessive increase of plasma renin concentration reported in the literature during aliskiren compared with irbesartan or amlodipine treatment.

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Nonlinear optical nanocrystals have been recently introduced as a promising alternative to fluorescent probes for multiphoton microscopy. We present for the first time a complete survey of the properties of five nanomaterials (KNbO(3), LiNbO(3), BaTiO(3), KTP, and ZnO), describing their preparation and stabilization and providing quantitative estimations of their nonlinear optical response. In the light of their prospective use as biological and clinical markers, we assess their biocompatibility on human healthy and cancerous cell lines. Finally, we demonstrate the great potential for cell imaging of these inherently nonlinear probes in terms of optical contrast, wavelength flexibility, and signal photostability.

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We aimed to analyze the changes in isokinetic internal (IR) and external (ER) rotator muscles fatigue (a) in patients with non-operated recurrent anterior instability, and (b) before and after shoulder surgical stabilization with the Bristow-Latarjet procedure. Thirty-seven patients with non-operated unilateral recurrent anterior post-traumatic instability (NG) were compared with 12 healthy subjects [control group (CG)]. Twenty patients with operated recurrent anterior instability group (OG) underwent isokinetic evaluation before and 3, 6, and 21 months after Bristow-Latarjet surgery. IR and ER muscles strength was evaluated with Con-Trex® dynamometer, with subjects seated and at a 45° shoulder abduction angle in scapular plane. IR and ER muscle fatigue was determined after 10 concentric repetitions at 180° · s(-1) through the fatigue index, the percent decrease in performance (DP), and the slope of peak torque decrease. There were no differences in rotator muscles fatigue between NG and CG. In OG, 3 months post-surgery, IR DP of operated shoulder was significantly (P < 0.001) higher than presurgery and 6 and 21 months post-surgery. Rotator muscles fatigability was not associated with recurrent anterior instability. After surgical stabilization, there was a significantly higher IR fatigability in the operated shoulder 3 months post-surgery, followed by recovery evidenced 6 months post-surgery and long-term maintenance over 21 months.

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Se ha estudiado los efectos que tiene la aplicación de cenizas de caldera de biomasa, en el modelo jerárquico de agregación (Tisdall y Oades, 1982) y en la estabilización del C orgánico en un suelo forestal situado en la zona templada del País Vasco. Para ello, se aplicaron 3 tratamientos con diferentes dosis de ceniza en muestras de suelo tamizadas a 250 μm procedentes de un huerto semillero de pinus radiata. Estas muestras fueron incubadas durante 3 meses y fraccionadas los días 29, 44, 64, 78 y 92 con la intención de separar los macroagregados grandes (LMagg), de los macroagregados pequeños (Magg), microagregados (magg), limos (silt) y arcillas (clay). Todas las fracciones fueron analizadas para determinar su contenido en C orgánico. Los resultados mostraron que con la aplicación de cenizas, el modelo jerárquico de agregación de suelo se cumple para las fracciones LMagg, Magg y magg, pero no para la fracción silt. Además se ha observado que las cenizas promueven la formación de microagregados aumentado así la capacidad de secuestro de C del suelo, pero en cambio disminuye la proporción de macroagregados, hecho que podría acarrear una disminución en la calidad estructural del suelo.

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El objetivo del presente proyecto ha sido estudiar los efectos del biochar en el modelo jerárquico de agregación del suelo. Para estudiar estas propiedades se ha realizado una incubación de tres tratamientos de biochar Miscanthus (biochar 10t/ha (B10), 2t/ha (B2) y 10t/ha+Nitrógeno (BN), durante 91 días, realizando fraccionamientos en húmedo de las muestras los días 28, 43, 63, 77 y 91. En estos fraccionamientos se han separado las fracciones macroagregrado (LMagg+Magg), microagregados (magg), limos (Silt) y arcillas (Clay). Por último se determinó el C orgánico de todas las fracciones de los tratamientos obtenidos con el objeto de obtener información sobre el efecto que puede tener la aplicación del biochar sobre la estabilización de C en las fracciones del suelo. Los resultados obtenidos indican que con la aplicación de biochar, la teoría jerárquica de agregación propuesta por Tisdall y Oades (1982), no se cumple en la dinámica de agregación del suelo, si bien se puede observar una jerarquía en la estabilización del C orgánico en los macroagregados y microagregados. Además las dosis altas de biochar producen mayor cantidad de microagregados, favoreciendo el secuestro de C en el suelo. Por otro lado, con dosis altas de biochar se aprecia una disminución de la fracción de macroagregados, hecho que puede influir negativamente en la estructura del suelo.

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Neurofilaments are typical structures of the neuronal cytoskeleton and participate in the formation and stabilization of the axonal and dendritic architecture. In this study, we have characterized a murine monoclonal antibody, FNP7, that is directed against the medium-sized neurofilament subunit NF-M. This antibody identifies a subset of neurons in the cerebral cortex of various species including human and in organotypic cultures of rat cortex. In the neocortex of all species examined, the antibody labels pyramidal cells in layers III, V, and VI, with a distinctive laminar distribution between architectonic boundaries. In comparison with other antibodies directed against NF-M, the FNP7 antibody identifies on blots two forms of NF-M that appear relatively late during development, at the time when dynamic growth of processes changes to the stabilization of the formed processes. Dephosphorylation with alkaline phosphatase unmasks the site, making it detectable for the FNP7 antibody. The late appearance suggests that the site is present during early development in phosphorylated form and with increasing maturation becomes dephosphorylated, mainly in dendrites. This event may relate to changes in cytoskeleton stability in a late phase of dendritic maturation. Furthermore, mainly corticofugal projections and only few callosal axons are stained, suggesting a differential phosphorylation in a subset of axons. The antibody provides a useful marker to study subsets of pyramidal cells in vivo, in vitro, and under experimental conditions.

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To measure the average length of telomere repeats at chromosome ends in individual cells we developed a flow cytometry method using fluorescence in situ hybridization (flow FISH) with labeled peptide nucleic acid (PNA) probes. Results of flow FISH measurements correlated with results of conventional telomere length measurements by Southern blot analysis (R = 0.9). Consistent differences in telomere length in CD8+ T-cell subsets were identified. Naive and memory CD4+ T lymphocytes in normal adults differed by around 2.5 kb in telomere length, in agreement with known replicative shortening of telomeres in lymphocytes in vivo. T-cell clones grown in vitro showed stabilization of telomere length after an initial decline and rare clones capable of growing beyond 100 population doublings showed variable telomere length. These results show that flow FISH can be used to measure specific nucleotide repeat sequences in single cells and indicate that the very large replicative potential of lymphocytes is only indirectly related to telomere length.

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We report a patient with Marfan's syndrome and pectus excavatum who underwent open heart surgery with simultaneous correction of the sternal malformation. Permanent internal stabilization, achieved by bilateral overlapping of the bevelled ends of the lowest ribs and reinforced with sternal closure wires offered a maintained postoperative chest wall stability, avoided the potential postoperative complications of cardiac compression, and improved the aesthetic appearance of the anterior chest wall. The increased risk of bleeding due to extensive dissection was minimized by postponing the repair of pectus excavatum to when protamin is administered after termination of cardiopulmonary bypass.

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In neurons, the regulation of microtubules plays an important role for neurite outgrowth, axonal elongation, and growth cone steering. SCG10 family proteins are the only known neuronal proteins that have a strong destabilizing effect, are highly enriched in growth cones and are thought to play an important role during axonal elongation. MAP1B, a microtubule-stabilizing protein, is found in growth cones as well, therefore it was important to test their effect on microtubules in the presence of both proteins. We used recombinant proteins in microtubule assembly assays and in transfected COS-7 cells to analyze their combined effects in vitro and in living cells, respectively. Individually, both proteins showed their expected activities in microtubule stabilization and destruction respectively. In MAP1B/SCG10 double-transfected cells, MAP1B could not protect microtubules from SCG10-induced disassembly in most cells, in particular not in cells that contained high levels of SCG10. This suggests that SCG10 is more potent to destabilize microtubules than MAP1B to rescue them. In microtubule assembly assays, MAP1B promoted microtubule formation at a ratio of 1 MAP1B per 70 tubulin dimers while a ratio of 1 SCG10 per two tubulin dimers was needed to destroy microtubules. In addition to its known binding to tubulin dimers, SCG10 binds also to purified microtubules in growth cones of dorsal root ganglion neurons in culture. In conclusion, neuronal microtubules are regulated by antagonistic effects of MAP1B and SCG10 and a fine tuning of the balance of these proteins may be critical for the regulation of microtubule dynamics in growth cones.

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Stability berms are commonly constructed where roadway embankments cross soft or unstable ground conditions. Under certain circumstances, the construction of stability berms cause unfavorable environmental impacts, either directly or indirectly, through their effect on wetlands, endangered species habitat, stream channelization, longer culvert lengths, larger right-of-way purchases, and construction access limits. Due to an ever more restrictive regulatory environment, these impacts are problematic. The result is the loss of valuable natural resources to the public, lengthy permitting review processes for the department of transportation and permitting agencies, and the additional expenditures of time and money for all parties. The purpose of this project was to review existing stability berm alternatives for potential use in environmentally sensitive areas. The project also evaluates how stabilization technologies are made feasible, desirable, and cost-effective for transportation projects and determines which alternatives afford practical solutions for avoiding and minimizing impacts to environmentally sensitive areas. An online survey of engineers at state departments of transportation was also conducted to assess the frequency and cost effectiveness of the various stabilization technologies. Geotechnical engineers that responded to the survey overwhelmingly use geosynthetic reinforcement as a suitable and cost-effective solution for stabilizing embankments and cut slopes. Alternatively, chemical stabilization and installation of lime/cement columns is rarely a remediation measure employed by state departments of transportation.

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1. The major side effects of the immunosuppressive drug cyclosporin A (CsA) are hypertension and nephrotoxicity. It is likely that both are caused by local vasoconstriction. 2. We have shown previously that 20 h treatment of rat vascular smooth muscle cells (VSMC) with therapeutically relevant CsA concentrations increased the cellular response to [Arg8]vasopressin (AVP) by increasing about 2 fold the number of vasopressin receptors. 3. Displacement experiments using a specific antagonist of the vasopressin V1A receptor (V1AR) showed that the vasopressin binding sites present in VSMC were exclusively receptors of the V1A subtype. 4. Receptor internalization studies revealed that CsA (10(-6) M) did not significantly alter AVP receptor trafficking. 5. V1AR mRNA was increased by CsA, as measured by quantitative polymerase chain reaction. Time-course studies indicated that the increase in mRNA preceded cell surface expression of the receptor, as measured by hormone binding. 6. A direct effect of CsA on the V1AR promoter was investigated using VSMC transfected with a V1AR promoter-luciferase reporter construct. Surprisingly, CsA did not increase, but rather slightly reduced V1AR promoter activity. This effect was independent of the cyclophilin-calcineurin pathway. 7. Measurement of V1AR mRNA decay in the presence of the transcription inhibitor actinomycin D revealed that CsA increased the half-life of V1AR mRNA about 2 fold. 8. In conclusion, CsA increased the response of VSMC to AVP by upregulating V1AR expression through stabilization of its mRNA. This could be a key mechanism in enhanced vascular responsiveness induced by CsA, causing both hypertension and, via renal vasoconstriction, reduced glomerular filtration.

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The present thesis comprises two study populations. The first study sample (SS1) consisted of 411 adults examined and interviewed at three annual visits. The second study sample (SS2) consisted of 1720 adults who filled in a mailed questionnaire about secondary otalgia, tinnitus and fullness of ears. In the second phase of the SS2, 100 subjects with otalgia were examined and interviewed by specialist in stomatognathic physiology and otorhinolaryngology. In the third phase, 36 subjects participated in a randomized, controlled and blinded trial of effectiveness of occlusal appliance on secondary otalgia, facial pain, headache and treatment need of temporomandibular disorders (TMD). The standardized prevalence of recurrent secondary otalgia was 6%, tinnitus 15% and fullness of ears 8%. Aural symptoms were more frequent among young than old subjects. They were associated with other, simultaneous aural symptoms, TMD pain, head and neck region pain, and visits to a physician. The subjects with aural symptoms more often had tenderness on palpation of masticatory muscles and clinical signs of temporomandibular joint than the subjects without. 85% of the subjects reporting secondary otalgia had cervical spine or temporomandibular disorder or both. In SS1, the final model of secondary otalgia included active need treatment for TMD, elevated level of stress symptoms, and bruxism. In SS2, the final models of aural symptoms included associated aural symptoms, young age, TMD pain, headache and shoulder ache. Stabilization splint more effectively alleviated secondary otalgia and active treatment need for TMD than a palatal control splint. In patients with aural pain, tinnitus or fullness of ears, it is important to first rule out otologic and nasopharyngeal diseases that may cause the symptoms. If no explanation for aural symptoms is found, temporomandibular and cervical spine disorders should be rouled out to minimize unnecessary visits to a physician.

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According to the Taylor principle a central bank should adjust the nominal interest rate by more than one-for-one in response to changes in current inflation. Most of the existing literature supports the view that by following this simple recommendation a central bank can avoid being a source of unnecessary fluctuations in economic activity. The present paper shows that this conclusion is not robust with respect to the modelling of capital accumulation. We use our insights to discuss the desirability of alternative interest rate rules. Our results suggest a reinterpretation of monetary policy under Volcker and Greenspan: The empirically plausible characterization of monetary policy can explain the stabilization of macroeconomic outcomes observed in the early eighties for the US economy. The Taylor principle in itself cannot.