Bibliographies thématiques / PRKN

Sommaire

Articles de revues
Thèses
Livres
Chapitres de livres
Actes de conférences
Rapports d'organisations

Littérature scientifique sur le sujet « PRKN »

Auteur : Grafiati

Publié le 9 mars 2023

Mis à jour le 10 mars 2023

Créez une référence correcte selon les styles APA, MLA, Chicago, Harvard et plusieurs autres

Choisissez une source :

Consultez les listes thématiques d’articles de revues, de livres, de thèses, de rapports de conférences et d’autres sources académiques sur le sujet « PRKN ».

À côté de chaque source dans la liste de références il y a un bouton « Ajouter à la bibliographie ». Cliquez sur ce bouton, et nous générerons automatiquement la référence bibliographique pour la source choisie selon votre style de citation préféré : APA, MLA, Harvard, Vancouver, Chicago, etc.

Vous pouvez aussi télécharger le texte intégral de la publication scolaire au format pdf et consulter son résumé en ligne lorsque ces informations sont inclues dans les métadonnées.

Articles de revues sur le sujet "PRKN"

Sophocleous, Georgios, Darerca Owen et Helen R. Mott. « The structure and function of protein kinase C-related kinases (PRKs) ». Biochemical Society Transactions 49, n^o 1 (1 février 2021) : 217–35. http://dx.doi.org/10.1042/bst20200466.

Texte intégral

Résumé :

The protein kinase C-related kinase (PRK) family of serine/threonine kinases, PRK1, PRK2 and PRK3, are effectors for the Rho family small G proteins. An array of studies have linked these kinases to multiple signalling pathways and physiological roles, but while PRK1 is relatively well-characterized, the entire PRK family remains understudied. Here, we provide a holistic overview of the structure and function of PRKs and describe the molecular events that govern activation and autoregulation of catalytic activity, including phosphorylation, protein interactions and lipid binding. We begin with a structural description of the regulatory and catalytic domains, which facilitates the understanding of their regulation in molecular detail. We then examine their diverse physiological roles in cytoskeletal reorganization, cell adhesion, chromatin remodelling, androgen receptor signalling, cell cycle regulation, the immune response, glucose metabolism and development, highlighting isoform redundancy but also isoform specificity. Finally, we consider the involvement of PRKs in pathologies, including cancer, heart disease and bacterial infections. The abundance of PRK-driven pathologies suggests that these enzymes will be good therapeutic targets and we briefly report some of the progress to date.

Styles APA, Harvard, Vancouver, ISO, etc.

Lubbe, Steven J., Bernabe I. Bustos, Jing Hu, Dimitri Krainc, Theresita Joseph, Jason Hehir, Manuela Tan et al. « Assessing the relationship between monoallelic PRKN mutations and Parkinson’s risk ». Human Molecular Genetics 30, n^o 1 (1 janvier 2021) : 78–86. http://dx.doi.org/10.1093/hmg/ddaa273.

Texte intégral

Résumé :

Abstract Biallelic Parkin (PRKN) mutations cause autosomal recessive Parkinson’s disease (PD); however, the role of monoallelic PRKN mutations as a risk factor for PD remains unclear. We investigated the role of single heterozygous PRKN mutations in three large independent case-control cohorts totalling 10 858 PD cases and 8328 controls. Overall, after exclusion of biallelic carriers, single PRKN mutations were more common in PD than controls conferring a >1.5-fold increase in the risk of PD [P-value (P) = 0.035], with meta-analysis (19 574 PD cases and 468 488 controls) confirming increased risk [Odds ratio (OR) = 1.65, P = 3.69E-07]. Carriers were shown to have significantly younger ages at the onset compared with non-carriers (NeuroX: 56.4 vs. 61.4 years; exome: 38.5 vs. 43.1 years). Stratifying by mutation type, we provide preliminary evidence for a more pathogenic risk profile for single PRKN copy number variant (CNV) carriers compared with single nucleotide variant carriers. Studies that did not assess biallelic PRKN mutations or consist of predominantly early-onset cases may be biasing these estimates, and removal of these resulted in a loss of association (OR = 1.23, P = 0.614; n = 4). Importantly, when we looked for additional CNVs in 30% of PD cases with apparent monoallellic PRKN mutations, we found that 44% had biallelic mutations, suggesting that previous estimates may be influenced by cryptic biallelic mutation status. While this study supports the association of single PRKN mutations with PD, it highlights confounding effects; therefore, caution is needed when interpreting current risk estimates. Together, we demonstrate that comprehensive assessment of biallelic mutation status is essential when elucidating PD risk associated with monoallelic PRKN mutations.

Styles APA, Harvard, Vancouver, ISO, etc.

Koinuma, Takahiro, Taku Hatano, Koji Kamagata, Christina Andica, Akio Mori, Takashi Ogawa, Haruka Takeshige-Amano et al. « Diffusion MRI Captures White Matter Microstructure Alterations in PRKN Disease ». Journal of Parkinson's Disease 11, n^o 3 (2 août 2021) : 1221–35. http://dx.doi.org/10.3233/jpd-202495.

Texte intégral

Résumé :

Background: Although pathological studies usually indicate pure dopaminergic neuronal degeneration in patients with parkin (PRKN) mutations, there is no evidence to date regarding white matter (WM) pathology. A previous diffusion MRI study has revealed WM microstructural alterations caused by systemic oxidative stress in idiopathic Parkinson’s disease (PD), and we found that PRKN patients have systemic oxidative stress in serum biomarker studies. Thus, we hypothesized that PRKN mutations might lead to WM abnormalities. Objective: To investigate whether there are WM microstructural abnormalities in early-onset PD patients with PRKN mutations using diffusion tensor imaging (DTI). Methods: Nine PRKN patients and 15 age- and sex-matched healthy controls were recruited. DTI measures were acquired on a 3T MR scanner using a b value of 1,000 s/mm2 along 32 isotropic diffusion gradients. The DTI measures were compared between groups using tract-based spatial statistics (TBSS) analysis. Correlation analysis was also performed between the DTI parameters and several serum oxidative stress markers obtained in a previously conducted metabolomic analysis. Results: Although the WM volumes were not significantly different, the TBSS analysis revealed a corresponding decrease in fractional anisotropy and an increase in mean diffusivity and radial diffusivity in WM areas, such as the anterior and superior corona radiata and uncinate fasciculus, in PRKN patients compared with controls. Furthermore, 9-hydroxystearate, an oxidative stress marker, and disease duration were positively correlated with several parameters in PRKN patients. Conclusion: This pilot study suggests that WM microstructural impairments occur in PRKN patients and are associated with disease duration and oxidative stress.

Styles APA, Harvard, Vancouver, ISO, etc.

Borsche, Max, Inke R. König, Sylvie Delcambre, Simona Petrucci, Alexander Balck, Norbert Brüggemann, Alexander Zimprich et al. « Mitochondrial damage-associated inflammation highlights biomarkers in PRKN/PINK1 parkinsonism ». Brain 143, n^o 10 (1 octobre 2020) : 3041–51. http://dx.doi.org/10.1093/brain/awaa246.

Texte intégral

Résumé :

Abstract There is increasing evidence for a role of inflammation in Parkinson’s disease. Recent research in murine models suggests that parkin and PINK1 deficiency leads to impaired mitophagy, which causes the release of mitochondrial DNA (mtDNA), thereby triggering inflammation. Specifically, the CGAS (cyclic GMP-AMP synthase)-STING (stimulator of interferon genes) pathway mitigates activation of the innate immune system, quantifiable as increased interleukin-6 (IL6) levels. However, the role of IL6 and circulating cell-free mtDNA in unaffected and affected individuals harbouring mutations in PRKN/PINK1 and idiopathic Parkinson’s disease patients remain elusive. We investigated IL6, C-reactive protein, and circulating cell-free mtDNA in serum of 245 participants in two cohorts from tertiary movement disorder centres. We performed a hypothesis-driven rank-based statistical approach adjusting for multiple testing. We detected (i) elevated IL6 levels in patients with biallelic PRKN/PINK1 mutations compared to healthy control subjects in a German cohort, supporting the concept of a role for inflammation in PRKN/PINK1-linked Parkinson’s disease. In addition, the comparison of patients with biallelic and heterozygous mutations in PRKN/PINK1 suggests a gene dosage effect. The differences in IL6 levels were validated in a second independent Italian cohort; (ii) a correlation between IL6 levels and disease duration in carriers of PRKN/PINK1 mutations, while no such association was observed for idiopathic Parkinson’s disease patients. These results highlight the potential of IL6 as progression marker in Parkinson’s disease due to PRKN/PINK1 mutations; (iii) increased circulating cell-free mtDNA serum levels in both patients with biallelic or with heterozygous PRKN/PINK1 mutations compared to idiopathic Parkinson’s disease, which is in line with previous findings in murine models. By contrast, circulating cell-free mtDNA concentrations in unaffected heterozygous carriers of PRKN/PINK1 mutations were comparable to control levels; and (iv) that circulating cell-free mtDNA levels have good predictive potential to discriminate between idiopathic Parkinson’s disease and Parkinson’s disease linked to heterozygous PRKN/PINK1 mutations, providing functional evidence for a role of heterozygous mutations in PRKN or PINK1 as Parkinson’s disease risk factor. Taken together, our study further implicates inflammation due to impaired mitophagy and subsequent mtDNA release in the pathogenesis of PRKN/PINK1-linked Parkinson’s disease. In individuals carrying mutations in PRKN/PINK1, IL6 and circulating cell-free mtDNA levels may serve as markers of Parkinson’s disease state and progression, respectively. Finally, our study suggests that targeting the immune system with anti-inflammatory medication holds the potential to influence the disease course of Parkinson’s disease, at least in this subset of patients.

Styles APA, Harvard, Vancouver, ISO, etc.

Di Rita, Anthea, Teresa Maiorino, Krenare Bruqi, Floriana Volpicelli, Gian Carlo Bellenchi et Flavie Strappazzon. « miR-218 Inhibits Mitochondrial Clearance by Targeting PRKN E3 Ubiquitin Ligase ». International Journal of Molecular Sciences 21, n^o 1 (5 janvier 2020) : 355. http://dx.doi.org/10.3390/ijms21010355.

Texte intégral

Résumé :

The selective elimination of dysfunctional mitochondria through mitophagy is crucial for preserving mitochondrial quality and cellular homeostasis. The most described mitophagy pathway is regulated by a positive ubiquitylation feedback loop in which the PINK1 (PTEN induced kinase 1) kinase phosphorylates both ubiquitin and the E3 ubiquitin ligase PRKN (Parkin RBR E3 ubiquitin ligase), also known as PARKIN. This event recruits PRKN to the mitochondria, thus amplifying ubiquitylation signal. Here we report that miR-218 targets PRKN and negatively regulates PINK1/PRKN-mediated mitophagy. Overexpression of miR-218 reduces PRKN mRNA levels, thus also reducing protein content and deregulating the E3 ubiquitin ligase action. In fact, following miR-218 overexpression, mitochondria result less ubiquitylated and the autophagy machinery fails to proceed with correct mitochondrial clearance. Since mitophagy defects are associated with various human diseases, these results qualify miR-218 as a promising therapeutic target for human diseases.

Styles APA, Harvard, Vancouver, ISO, etc.

Fan, Kuan, Pengzhi Hu, Chengyuan Song, Xiong Deng, Jie Wen, Yiming Liu et Hao Deng. « Novel Compound Heterozygous PRKN Variants in a Han-Chinese Family with Early-Onset Parkinson’s Disease ». Parkinson's Disease 2019 (23 décembre 2019) : 1–6. http://dx.doi.org/10.1155/2019/9024894.

Texte intégral

Résumé :

Genetic factors are thought to play an important role in the pathogenesis of Parkinson’s disease (PD), particularly early-onset PD. The PRKN gene is the primary disease-causing gene for early-onset PD. The details of its functions remain unclear. This study identified novel compound heterozygous variants (p.T240K and p.L272R) of the PRKN gene in a Han-Chinese family with early-onset PD. This finding is helpful in the genetic diagnosis of PD and also the functional research of the PRKN gene.

Styles APA, Harvard, Vancouver, ISO, etc.

Li, Dunhui, May T. Aung-Htut, Kristin A. Ham, Sue Fletcher et Steve D. Wilton. « A Splice Intervention Therapy for Autosomal Recessive Juvenile Parkinson’s Disease Arising from Parkin Mutations ». International Journal of Molecular Sciences 21, n^o 19 (1 octobre 2020) : 7282. http://dx.doi.org/10.3390/ijms21197282.

Texte intégral

Résumé :

Parkin-type autosomal recessive juvenile-onset Parkinson’s disease is caused by mutations in the PRKN gene and accounts for 50% of all autosomal recessive Parkinsonism cases. Parkin is a neuroprotective protein that has dual functions as an E3 ligase in the ubiquitin–proteasome system and as a transcriptional repressor of p53. While genomic deletions of PRKN exon 3 disrupt the mRNA reading frame and result in the loss of functional parkin protein, deletions of both exon 3 and 4 maintain the reading frame and are associated with a later onset, milder disease progression, indicating this particular isoform retains some function. Here, we describe in vitro evaluation of antisense oligomers that restore functional parkin expression in cells derived from a Parkinson’s patient carrying a heterozygous PRKN exon 3 deletion, by inducing exon 4 skipping to correct the reading frame. We show that the induced PRKN transcript is translated into a shorter but semi-functional parkin isoform able to be recruited to depolarised mitochondria, and also transcriptionally represses p53 expression. These results support the potential use of antisense oligomers as a disease-modifying treatment for selected pathogenic PRKN mutations.

Styles APA, Harvard, Vancouver, ISO, etc.

Palmer, R. H., et P. J. Parker. « Expression, purification and characterization of the ubiquitous protein kinase C-related kinase 1 ». Biochemical Journal 309, n^o 1 (1 juillet 1995) : 315–20. http://dx.doi.org/10.1042/bj3090315.

Texte intégral

Résumé :

The recently described protein kinase C-related kinase (PRK) family is comprised of at least three members: PRK1, PRK2 and PRK3. Here the expression, purification and characterization of the ubiquitously expressed isoform, PRK1, is described. The enzyme was expressed in COS 7 cells and subsequently purified to apparent homogeneity by sequential column chromatography. The purified PRK1 protein migrates as a single 120 kDa polypeptide on SDS/PAGE. It displays a substrate specificity that in part resembles that of protein kinase C (PKC); however, unlike PKC, it is not activated by any combination of phorbol esters, diacylglycerol and Ca2+. Nevertheless, it can be activated by limited proteolysis, indicating a negative regulatory role for the N-terminal domain(s). PRK1 is also activated by phospholipids. The physiological relevance of this activation is discussed.

Styles APA, Harvard, Vancouver, ISO, etc.

Broadway, Benjamin J., Paige K. Boneski, Jenny M. Bredenberg, Ana Kolicheski, Xu Hou, Alexandra I. Soto-Beasley, Owen A. Ross, Wolfdieter Springer et Fabienne C. Fiesel. « Systematic Functional Analysis of PINK1 and PRKN Coding Variants ». Cells 11, n^o 15 (5 août 2022) : 2426. http://dx.doi.org/10.3390/cells11152426.

Texte intégral

Résumé :

Loss of either PINK1 or PRKN causes an early onset Parkinson’s disease (PD) phenotype. Functionally, PINK1 and PRKN work together to mediate stress-activated mitochondrial quality control. Upon mitochondrial damage, PINK1, a ubiquitin kinase and PRKN, a ubiquitin ligase, decorate damaged organelles with phosphorylated ubiquitin for sequestration and degradation in lysosomes, a process known as mitophagy. While several genetic mutations are established to result in loss of mitophagy function, many others have not been extensively characterized and are of unknown significance. Here, we analyzed a set of twenty variants, ten in each gene, focusing on understudied variants mostly from the Parkinson’s progressive marker initiative, with sensitive assays to define potential functional deficits. Our results nominate specific rare genetic PINK1 and PRKN variants that cause loss of enzymatic function in line with a potential causative role for PD. Additionally, we identify several variants with intermediate phenotypes and follow up on two of them by gene editing midbrain-derived neuronal precursor cells. Thereof derived isogenic neurons show a stability defect of the rare PINK1 D525N mutation, while the common PINK1 Q115L substitution results in reduced kinase activity. Our strategy to analyze variants with sensitive functional readouts will help aid diagnostics and disease treatment in line with current genomic and therapeutic advances.

Styles APA, Harvard, Vancouver, ISO, etc.

Lei, Yuchen, et Daniel J. Klionsky. « New regulators of PRKN-independent mitophagy ». Autophagy 18, n^o 1 (19 décembre 2021) : 1–3. http://dx.doi.org/10.1080/15548627.2021.2012867.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Thèses sur le sujet "PRKN"

TREZZI, ILARIA. « INVESTIGATING GLUTAMATE TOXICITY ASSOCIATED TO PARK2 MUTATIONS IN PRE-CLINICAL MODELS OF PARKINSON¿S DISEASE ». Doctoral thesis, Università degli Studi di Milano, 2022. http://hdl.handle.net/2434/925250.

Texte intégral

Résumé :

ABSTRACT Background: Park2 mutations cause Autosomal Recessive Juvenile Parkinsonism (ARJP), characterized by the loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). Park2 encodes for a ubiquitin-ligase protein whose mutation upregulates Gluk2, a subunit of the glutamate kainate receptor (KAR), expressed in SNpc neurons. Park2 is highly expressed also in astrocytes and KARs upregulation may induce excitotoxicity both in DA neurons and glia, leading to an early synaptopathy, neuroinflamation and neurodegeneration. Aims and Objectives: 1. To generate Park2 induced pluripotent stem cells (iPSCs)-derived in vitro cellular models; 2. To characterize Park2 iPSCs-derived in vitro cellular models; 3. to test glutamate toxicity due to KAR upregulation in Park2 cellular models. Materials and Methods: Fibroblasts and lymphocytes from Park2 patients and age-matched controls were reprogrammed into iPSCs. The iPSCs were further differentiated into dopaminergic neurons, astrocytes and mesencephalic organoids were generated and differentiated. Protein expression profile was analysed through western blot (WB), qPCR and immunofluorescence (IF). Electrophysiology assessment was performed on dopaminergic neurons and midbrain organoids in order to better functionally profile these models. Results: Gluk2 levels resulted significantly increased in PARK2 midbrain organoids compared to CTR both at WB (p< 0.001) and qPCR analyses (p< 0.001). Gluk2 levels resulted also significantly enhanced in PARK2 astrocytes both at WB (p< 0.05) and qPCR analyses (p< 0.05). TH mRNA and protein levels were significantly increased both in PARK2 dopaminergic neurons (WB p< 0.01; qPCR p< 0.0001; IF p< 0.0001) and midbrain organoids (WB p< 0.01; qPCR p< 0.0001; IF p< 0.0001) compared to CTR. Glial fibrillary acidic protein (GFAP), a marker of reactive astrocytes, resulted enhanced in PARK2 astrocytes and especially in PARK2 midbrain organoids (WB p< 0.001; IF p< 0.01). EAAT2, the astrocytic glutamate transporter resulted reduced in mutated lines (WB p< 0.01). Calcium-imaging and HD-MEAs show an oscillatory augmented reactivity in PARK2 midbrain organoids. Conclusions and perspectives: Gluk2 expression was enhanced in PARK2 astrocytes and midbrain organoids, confirming the previous finding that Park2 mutations lead to KAR upregulation (Maraschi A, 2014). Neuronal reactivity was also found increased in PARK2 midbrain organoids at electrophysiology assessment, maybe linked to glutamate dysregulation. Two innovative findings emerged from this study. First of all, that TH expression resulted increased in PARK2, supporting previous finding that stated an augmented dopamine turnover and a reduced dopamine re-uptake (Jiang H., 2012). This is an impairment that happens early in the neurodegenerative process and that could consequently lead to an excessive oxidative stress and consequent neurodegeneration. The second original result is that PARK2 is associated to an increased astrocytic reactivity and a possible dysfunction of astrocytic glutamate transporter EAAT2. This finding means that astrocytes play a key role in neurodegeneration although it is not clear whether they contribute to the initiation or propagation of it. Their increased reactivity could be the consequence of a glutamate toxicity or glutamate toxicity could result from reactive astrocytes dysfunction, not able to process the excessive glutamate influx. Further studies are required in order to establish Park2 role in TH expression regulation, in astrocytic reactivity induction and in glutamate toxicity.

Styles APA, Harvard, Vancouver, ISO, etc.

Miele, Gino. « Analyses of gene expression in Prn-p+/+ and Prn-p-/- mice ». Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/22489.

Texte intégral

Résumé :

The Transmissible Spongiform Encephalopathies (TSEs) are a group of invariably fatal neurodegenerative diseases which manifest in a broad range of species. At present, the causative agent of the TSEs remains unknown. The only disease-specific macromolecule identified to date is a protease-resistant abnormal isoform (PrP^Sc) of a protease sensitive normal host-encoded glycoprotein (PrP^C). Despite the discovery of PrP^C more than a decade ago, the precise normal physiological function of this protein remains unknown. PrP^C is highly conserved across all species studied to date, and is expressed predominantly in neural tissues, but is also detected in non-neuronal tissues. PrP mRNA is developmentally regulated during embryogenesis, and has been shown to be widespread at E13.5. However, the precise timing of PrP mRNA transcriptional activation during murine embryogenesis has not been examined. Surprisingly, two lines of mice harbouring a null mutation in Prn-p, and which do not express detectable levels of PrP^C, are viable and develop and reproduce apparently normally. This thesis describes attempts to obtain clues to the normal physiological function of PrP^C by assessing the effect on gene expression of the ablation of PrP^C. To identify genes with altered expression profiles as a result of the ablation of PrP^C, the technique of Differential Display RT-PCR (DDRT-PCR) was optimised and utilised to undertake a comprehensive analysis of gene expression between Prn-p^+/+ and Prn-p^-/- postnatal developing brain. Five candidate genes were identified as being differentially expressed between Prn-p^+/+ and Prn-p^-/- brain. One of these genes was PrP, demonstrating the validity of the approach. The isolation, identification and expression of the remaining candidate transcripts is described. A detailed expression analysis of PrP mRNA expression was also performed and indicated that PrP is transcriptionally activated between E8.5 and E9 in the murine embryo, during neurulation. It was also demonstrated that PrP mRNA is developmentally regulated in the murine postnatal (P) developing brain, increasing in expression level approximately 8-fold from P0 to P42.

Styles APA, Harvard, Vancouver, ISO, etc.

Olivera, Espinoza César Augusto. « PRK : excimer láser experiencia hospitalaria ». Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2003. https://hdl.handle.net/20.500.12672/2018.

Texte intégral

Résumé :

El presente trabajo tiene por meta realizar un estudio prospectivo de un grupo de pacientes con diversos grados de Ametropia Miopica, protocolizandolos y sometiéndose a cirugía refractiva fotoablativa. PRK; no LASIK por no contar con el Microkeratomo. El protocolo ha sido diseñado para así uniformizar la elección de los pacientes y poder interpretar fidedignamente los resultados. Como es bien sabido el porcentaje de vicios de refracción. es muy atto en la población en general por lo tanto la necesidad de corregirlos con la tecnología actual es cada vez más imperante.
Tesis de segunda especialidad

Styles APA, Harvard, Vancouver, ISO, etc.

Couto, Gustavo de Alvarenga. « Efeito do ângulo da fieira na geometria e propriedades mecânicas de barras trefiladas ». Universidade Federal de Minas Gerais, 2011. http://hdl.handle.net/1843/PRCN-8P9GMW.

Texte intégral

Résumé :

In cold drawing of metallic bars most of the plastic flow is caused by compressive forces which arise from the reaction of the metal to the die. Due to the characteristics of the process this flow is not homogeneous along the cross section of the bar and is influenced by the die geometry. This inhomogeneous deformation generates residual stresses in the bars, which can produce a change in size and straightness during subsequent processes of cutting, grinding and heat treatment. This work presents an analysis of the influence of the die geometry and number of drawing passes on the final geometry and mechanical properties of drawn bars of SAE 1045 steel. Eight experiments were performed, with die angles of 12º, 18º, 30º and 40º, bearing lengths from 3,51mm to 7,09mm, and 01 or 02 passes of drawing. Measurements of straightness, roundness and diameter, microhardness and tensile tests were performed on the bars. Also were made measurements of straightness of shock absorbers rods after the induction hardening process. This study has shown that the die angle has a strong influence on the final geometry of the drawn bars; dies with high entry angle (30º and 40º) resulted in better values of straightness than dies with smaller angles (12º and 18º). Dies with high entry angle also resulted in less variation between the bearing diameter and the final diameter of the bar. It was also observed a strong relation between the straightness of the drawn bars and the straightness of the shock absorbers rods after the induction hardening process, where drawn bars with better straightness resulted in a better straightness of the shock absorbers rods after the induction hardening process.
Na trefilação a frio de barras metálicas a maior parte da deformação plástica é atribuída às tensões de compressão impostas ao material, devido ao contato entre a barra e a fieira. Devido às características do processo esta deformação não é homogênea ao longo da seção transversal da barra e seu nível é influenciado pela geometria da fieira. Esta deformação não homogênea gera tensões residuais nas barras trefiladas, as quais podem produzir uma mudança nas dimensões e retilineidade das mesmas, durante processos de corte, retífica e tratamento térmico ulteriores. Neste trabalho foi realizada uma análise da influência do ângulo e comprimento do paralelo da fieira, além do número de passes de trefilação, na geometria final e nas propriedades mecânicas das barras trefiladas de aço SAE 1045. Foram realizados oito experimentos, com ângulos de fieira de 12º, 18º, 30º e 40º, com comprimentos de paralelo de 3,51mm a 7,09mm, com 01 e 02 passes de trefilação. Para as barras trefiladas de cada experimento foram realizadas medições de retilineidade, diâmetro e ovalização, além de ensaios de microdureza e ensaios de tração completos. Também foram realizadas medições de retilineidade de hastes de amortecedor após o processo de têmpera superficial por indução. Com este trabalho foi possível verificar que o ângulo da fieira exerce forte influência na geometria final das barras trefiladas, sendo que fieiras com maior ângulo de entrada (30º e 40º) resultaram em melhores valores de retilineidade em comparação às fieiras com ângulos menores (12º e 18º). Fieiras com maior ângulo de entrada também resultaram em menor variação entre o diâmetro do paralelo e o diâmetro final da barra. Também foi observada uma forte relação entre a retilineidade das barras trefiladas e a retilineidade das hastes de amortecedor após o processo de têmpera superficial por indução, sendo que melhor retilineidade das barras trefiladas implicou em melhor retilineidade das hastes de amortecedor após o processo de têmpera.

Styles APA, Harvard, Vancouver, ISO, etc.

Bezerra, Augusto Cesar da Silva. « Concreto com fibras curtas de aço submetido a alta temperatura ». Universidade Federal de Minas Gerais, 2012. http://hdl.handle.net/1843/PRCN-8TEFUF.

Texte intégral

Résumé :

This study investigated conventional concrete with the addition of short fibers of steel in normal condition and after have been subjected to high temperature. The fibers were characterized by microscopy and mechanical tensile tests. The constituents of the cementitious composites were characterized. To evaluate the interaction between fibers and the cement matrix, were fabricated prismatic specimen partitioned with 40x40x160mm, the halves were connected by three fibers in the direction longititudinal and they were tested at flexion. To evaluate the cementitious composites reinforced, was molded 4 prismatic specimens with 150X150X500mm and 20 cylindrical with 100mm in diameter and 200mm in height for each type of model with fiber and without fiber. Half of the specimens was taken to the oven for heating. After heating, the raw samples and submitted high temperatures were mechanically characterized by compressive strength testing, tensile strength in diametral compression testing, tensile strength testing in bending and dynamic modulus of elasticity. The results show that there is a reduction in the mechanical properties after subjection to high temperatures, and smaller losses in fiber reinforced concrete.
O presente trabalho estudou concreto convencional com adição de fibras curtas de aço em condição normal e após ser submetido a temperatura elevada. As fibras foram caracterizadas por meio de técnicas de microscopia e ensaios mecânicos de tração. Os compósitos cimentícios tiveram seus constituintes caracterizados. Para avaliação da interação das fibras e matriz cimentícia foram confeccionados corpos-de-prova prismáticos de 40x40x160mm particionados, sendo as metades ligadas por três fibras na direção longititudinal e os mesmos foram ensaiados a flexão. Para a avaliação do compósito cimentício reforçado foram moldados 4 corpos-de-prova prismáticos de 150X150X500mm e 20 cilíndricos de 100mm de diâmetro e 200mm de altura para cada modelo de fibra e sem fibra. A metade dos corpos-de-prova foi levada ao forno para aquecimento. Após o aquecimento, os corpos-de-prova crus e submetidos à altas temperaturas foram caracterizados mecanicamente através dos ensaios de resistência à compressão, resistência à tração na compressão diametral, resistência à tração na flexão e modulo de elasticidade dinâmico. Os resultados demonstram que ocorre redução nas propriedades mecânicas após a submissão a temperaturas elevadas, sendo menores as perdas nos concretos reforçados com fibras.

Styles APA, Harvard, Vancouver, ISO, etc.

Sandgren, Daniel. « Test av brunnslock i komposit enligt standard prEN 124 ». Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-100025.

Texte intégral

Résumé :

Standarder finns i alla möjliga delar av samhället. De används för att säkerställa kvalité, säkerhet och effektivitet. Standarden för hur brunnslock produceras och designas heter prEN 124. Den har förändrats och det är grunden till detta projekt.Brunnspecialisten AB, ett företag i Holmsund, är projektets beställare och har behov av att godkänna sina brunnslock enligt prEN 124 för fortsatt försäljning.Projektets arbetsmoment kan delas in i tre saker. För det första att tolka vilka tester som behöver utföras för att godkänna brunnslock enligt prEN 124. För det andra definiera hur de ska utföras samt det tredje; att utföra fyra av dessa tester.Det certifierande organet är Svensk maskinprovning. De hade kunnat granska standarden prEN 124 och ta fram alla testmetoder. Med detta projekt hoppas deras granskning och då även Brunnspecialisten ABs kostnad kunna minskas.De definierade testerna ska sammanställas i ett dokument. Dokumentet har till uppgift att hjälpa Brunnspecialisten AB när brunnslocken ska certifieras enligt prEN 124. Tolv tester behöver utföras för certifiering. Åtta av dessa tester definieras och beskrivs i tidigare nämnda dokument. Till dokumentet bifogas också ett flödesschema. Flödesschemat visar i vilken ordning testerna ska utföras. Två av testerna utreds om de ens måste utföras. Anledningen är att prEN 124 beskriver en annan design än brunnslocken som Brunnspecialisten AB har. Utredningen visade att SMP godkänner den alternativa designen. Deformationstestet är endast med i flödesschemat. Halkskyddstestet undersöks inte alls i detta projekt.De fyra testerna som skulle utföras var vattenabsorptionstest, motstånd mot fordonsbränsle, stöttest och test av värmepåverkan. Dessa fyra tester genomfördes som planerat. Däremot blev utförandet något förenklat i vissa delar. Förenklingarna skedde av ekonomiska och tidsmässiga skäl.Resultaten från samtliga tester hamnade inom de krav som ställs utifrån prEN 124.De förenklingar som gjorts under projektet anses som acceptabla. Detta eftersom beställaren har deltagit och kunnat bedöma om mer resurser ska tillföras för att utföra testet noggrannare.De fyra testerna visar att brunnslocken troligen klarar att möta standarden prEN 124 för vattenabsorption, motstånd mot fordonsbränsle, stöttålighet och värmepåverkan.
Standards are used in all parts of society to secure quality, safety, and efficiency. Some guiding requirements for design and production as well as the certification methods for manhole covers are specified in standard prEN 124. It is currently undergoing changes and is the reason for this project.Brunnspecialisten AB, a company located in Holmsund, is the project owner. They need to certify their product according to prEN 124 to continue their business.The thesis project was devided into three parts. The first part presents what kind of tests that have to be made to secure that a gully top or manhole top meets the standard according to prEN 124. The second part interprets how these tests should be done and the third part; to carry out four of these tests.The defined tests are collected in a document. The purpose of the document is to help Brunnspecialisten AB when the manhole covers are to be certified according to prEN 124. Twelve tests are defined in the certification standard called prEN 124. Eight of these tests shall be interpreted and described in the previously mentioned document. With the document follows a flow chart. The flow chart shows in which order the tests are carried out. Two of the tests will not be carried out, and a part of this project investigates if they can be removed. SMP (Swedish Machinery Testing Institute) deemed that the tests can be skipped, accepting the alternative design which is the reason why the tests are undoable. The deformation test is only mentioned in the flow chart. Slip/skid resistance test was not included in this project.The certifying institution is the Swedish Machinery Testing Institute. They could read prEN 124 and develop the test methods for the manhole top certification. With this project the hope is to minimize the work that SMP needs to do in preparation for the certifying tests. The less work SMP put in the cheaper the certification will be for Brunnspecialisten AB.The four tests carried out in this project were water absorption, resistance against vehicle fluids, impact resistance and heat resistance. These four tests were carried out as planned, but on some parts the tests were not carried out as defined in prEN 124. The reasons were shortage of time and to save money.The results show that the manhole tops meet the requirements set in the standard prEN 124.The diversions done in the test process are considered acceptable. This is because the project owner has been participating in the tests, giving them the chance to add more resources to get more similarity to the defined test method.The four tests are deemed to make the gully top and manhole covers ready for certifying tests for water absorption, resistance against vehicle fluid, impact resistance, and heat resistance.

Styles APA, Harvard, Vancouver, ISO, etc.

Nejedlý, Zdeněk. « Mechanické a technologické vlastnosti duplexních ocelí v závislosti na hodnotě PREN ». Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2014. http://www.nusl.cz/ntk/nusl-231634.

Texte intégral

Résumé :

This thesis deals with stainless austenitic-ferritic (duplex) steels and their mechanical and technological properties. The first part focuses on introducing these high-alloy materials. The second part describes the influence of chemical composition on the mechanical properties, technological properties and steel structure. There was also observed the effect of heat treatment and steel melting under reduced pressure.

Styles APA, Harvard, Vancouver, ISO, etc.

Uliniuc, Ancuta. « Modificări chimice ale polizaharidelor şi ale hidrogelurilor lor prin procedeul "click chemistry" ». Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00834679.

Texte intégral

Résumé :

Ce travail a pour objet l'obtention et la caractérisation de nouveaux copolymères amphiphiles et d'hydrogels à hydrophilie contrôlée, à partir de polymères naturels, avec comme utilisations potentielles la vectorisation de principes actifs. En conséquence, il est donc nécessaire que les polymères utilisés pour l'obtention de ces architectures répondent à un certain nombre de contraintes, notamment être non-toxiques, biocompatibles et biodégradables. Pour ces raisons, on retient le plus souvent comme matériaux de départ des polymères naturels, en particulier les polysaccharides. Quelques polymères synthétiques répondent aussi à ces contraintes, telle que la polycaprolactone. Ainsi, le matériau de base utilisé dans ce travail est l'amidon sur lequel a été greffé soit la poly (ε-caprolactone), soit une chaîne grasse. La thèse est structurée en cinq chapitres consacrés d'une part au greffage de structures hydrophobes sur l'amidon et la formation d'hydrogels à hydrophobie modulable, d'autre part à la vectorisation de la lévofloxacine par ces composés. La première partie traite du greffage de la polycaprolactone sur l'amidon par "click chemistry" (CuAAC) entre l'amidon fonctionnalisé par des fonctions alcynes et des polycaprolactones à fonction azoture en bout de chaîne, ces dernières étant préalablement obtenues par POC de la caprolactone. Les réactions de CuAAC ont été effectuées non seulement selon les protocoles habituels, mais aussi par micro ondes. Par ailleurs, l'amidon a aussi été hydrophobisé par les méthodes usuelles d'estérification par une chaîne grasse via le chlorure de l'acide palmitoique. Les produits ainsi obtenus ont été caractérisés par RMN, IR, XPS et leur comportement dans différents solvants (solubilité, gonflement) a été étudié. Une seconde partie est consacrée à l'élaboration d'hydrogels à base d'amidon et d'amidon modifié avec des chaînes d'acides gras et de PCL par réticulation avec l'acide citrique. Afin d'atteindre les objectifs, une stratégie multifactorielle expérimentale avec deux variables indépendantes a été utilisée. La modélisation mathématique des données expérimentales permet de remonter aux paramètres physico-chimiques pertinents, montre les effets de synergie et établit les conditions d'optimisation. Une dernière partie a permis d'évaluer les cinétiques de libération de la lévofloxacine, un antibiotique de dernière génération, par les hydrogels obtenus. Les matériaux obtenus ont montré des propriétés de libération contrôlée potentiellement intéressantes. Les résultats obtenus au cours de cette thèse ont été évalués par la publication de trois articles et par dissémination des résultats au six conférences internationales.

Styles APA, Harvard, Vancouver, ISO, etc.

Stanciu, Nicoleta Doriana. « Compozite polimer-organice şi polimer-anorganice obţinute prin polimerizare radicalică „in situ” ». Thesis, Lyon 1, 2010. http://www.theses.fr/2010LYO10006.

Texte intégral

Résumé :

Ce travail porte sur l'obtention et la caractérisation de composites polymères à charges organiques et inorganiques obtenus par polymérisation radicalaire in situ de monomères dans une matrice organique de type cellulose ou inorganique de type silicate. Avec la cellulose, les monomères retenus sont d'abord des dérivés vinyliques de type acide (méth)acrylique et de comonomères tels que l'anhydride maléique, le styrène et le chlorométhylstyrène. Les produits sont caractérisés notamment par ATG et XRD. La conductivité électrique de ces composites en fonction de leur gonflement a été étudiée. La copolymérisation de l'anhydride maléique avec le dicyclopentadiène est ensuite étudiée dans le toluène et le dioxane. Ce type de copolymère n'avait pas été étudié jusqu'à présent. L'influence du type de solvant sur la conduite de la réaction est étudiée. La caractérisation des composites est effectuée par IR, XRD et microscopie SEM. L'interaction entre les composants est mise en évidence par XRD. Les composites à base de silicate sont obtenus par polymérisation radicalaire contrôlée après greffage de l'amorceur sur le support inorganique. Le greffage est caractérisé par IR. Les analyses XRD et IR mettent en évidence la prédominance du greffage du polymère à la surface du silicate. L'étude de la copolymérisation chlorométhylstyrène - méthacrylate d'hydroxyéthyle a été effectuée qui montre in fine l'influence du support sur la structure des copolymères. De même, les analyses XRD et IR révèlent la modification de la structure du silicate. La microscopie SEM met en évidence des structures homogènes. Une étude complète de dégradation thermique a été menée par ATG qui montre l'influence des différents polymères
The synthesis of organic-polymer or inorganic-polymer composites was a real challenge within the last decades due to the difficulty of optimally dispersing the reinforcing agent into the polymeric matrix. A method to solve this problem is the "in situ "polymerization. The first part of the experimental study deals with the synthesis of the polymer-cellulose composites. Cellulose-containing composites based on copolymers of acrylic acid with styrene, 4-chloro-methyl-styrene and maleic anhydride or based on copolymers of methacrylic acid with styrene and 4-chloro-methyl-styrene were prepared for proton conducting membranes. Next, cellulose composites with maleic anhydride – dicyclopentadiene copolymer matrix were obtained by “in situ” free-radical polymerization. The syntheses were carried out in two different solvents: toluene and dioxane, aiming to determine their influence upon both the polymerization process and properties of the resulting materials. To the best of our knowledge, studies concerning the preparation of this composite have not been published in the literature until now. The second part of the original contributions section is dedicated to the investigation of some polymer-layered silicates composites, using a commercial layered silicate (Cloisite 30B), modified with OH-containing quaternary ammonium salts. First, a new ATRP-based procedure to synthesize polymer-layered silicate composites involving a simpler method than those published in the literature up to now, was studied. The novelty of the methods consists in the one-step preparation of the ATRP initiating sites anchored onto the layered silicate by reacting the OH groups of the quaternary ammonium salt with chloroacetic anhydride, followed by the "in situ” ATRP of the monomer. This way several intermediate stages are eliminated. The last experimental study concerns the synthesis and characterization of a composite with an inorganic support (Cloisite 30B) and a polymeric matrix synthesized by the copolymerization of two different monomers with high reactivity: 2-hydroxyethyl methacrylate and 4-chloro-methyl-styrene. To our knowledge, there are no studies published in the literature describing the preparation of this composite until now. The obtained composite materials were characterized both structurally by FT-IR, NMR, XRD and SEM, and from the thermal behavior point of view by TGA-DSC-MS

Styles APA, Harvard, Vancouver, ISO, etc.

Netto, Marcelo Vieira. « Efeitos do uso tópico da mitomicina C na prevenção e tratamento da opacidade corneana em coelhos submetidos à ceratectomia fotorrefrativa ». Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/5/5149/tde-20022009-132232/.

Texte intégral

Résumé :

Objetivos: Determinar os efeitos celulares e o mecanismo de ação da mitomicina C tópica na prevenção e tratamento da opacidade corneana em coelhos submetidos à ceratectomia fotorrefrativa (PRK). Métodos: Foram submetidos à cirurgia de PRK 224 coelhos para correção de -9 dioptrias esféricas, associada à aplicação de mitomicina C tópica ou solução salina balanceada. O nível de opacidade corneana foi avaliado por meio de análise à lâmpada de fenda. Os animais foram sacrificados quatro horas, 24 horas, quatro semanas e seis meses após a cirurgia. A análise imunohistoquímica foi realizada com as técnicas de TUNEL e foram utilizados os anticorpos Ki67 e alpha-SMA para a análise da apoptose celular, replicação celular e formação de miofibroblastos, respectivamente. Resultados: Todos os grupos submetidos à aplicação de mitomicina C apresentaram um maior número de células positivamente marcadas pelo ensaio com TUNEL (indicando maior taxa de apoptose celular) e um menor número de células positivamente marcadas pelo anticorpo Ki67 (indicando menor taxa de replicação celular). Uma menor quantidade de miofibroblastos (células positivamente marcadas pelo anticorpo alpha-SMA) foi identificada após a aplicação profilática da mitomicina C, comparada com sua aplicação com finalidade terapêutica. Além disso, identificou-se uma zona de acelularidade no estroma anterior de córneas tratadas com mitomicina C, persistente por um período mínimo de seis meses. Conclusões: A aplicação da mitomicina C diminuiu signficativamente a formação de opacidade corneana em coelhos. Apesar da mitomicina C ter induzido uma maior apoptose de ceratócitos e miofibroblastos, seu principal mecanismo de ação, responsável pela prevenção da opacidade corneana, decorreu do bloqueio da replicação dos ceratócitos ou outras linhagens celulares progenitoras dos miofibroblastos. A aplicação da mitomicina C na concentração de 0,002% mostrou-se tão eficiente quanto sua aplicação na concentração de 0,02%. Não obstante, uma persistente diminuição da densidade de ceratócitos no estroma anterior pode representar um sinal de alerta para possíveis complicações a longo prazo
Purpose: To determine cellular effects and the mechanism through which topical mitomycin C prevents and treats corneal haze after photorefractive keratectomy (PRK) in rabbits. Methods: Minus nine diopters PRK with mitomycin C or balanced salt solution was performed in two hundred and twenty four New Zealand rabbits. Haze level was graded at the slit lamp. Rabbits were sacrificed at 4 hours, 24 hours, 4 weeks or 6 months after surgery and immunohistochemistry was performed with TUNEL assay, Ki67 and alpha-SMA to analyze keratocyte cells apoptosis, keratocyte cells replication and myofibroblast cells formation, respectively. Results: TUNEL-positive cells increased in all mitomycin C groups (representing more keratocyte cells undergoing apoptosis) while Ki67-positive cells decreased significanlty (representing a decreased keratocyte cells replication) following mitomycin C application. A greater decrease in myofibroblasts was noted with prophylactic mitomycin C treatment than therapeutic mitomycin C treatment. There was, however, an anterior stromal acellular zone in eyes treated with mitomycin C that persisted out to the maximum follow-up of 6 months. Conclusion: Mitomycin C application significantly reduced corneal haze formation in rabbits. Its treatment induces apoptosis of keratocytes and myofibroblasts, but the predominate effect in inhibiting or treating haze appears to be at the level of blocked replication of keratocytes or other progenitor cells of myofibroblasts. Treatment with 0.002% mitomycin C appears to be just as effective as higher concentrations (0.02%) in the rabbit model. However, a persistent decrease in keratocyte cells density in the anterior stroma could be a warning sign for future complications

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Livres sur le sujet "PRKN"

Oprea, Ștefan. Prin teatre și prin ani. Iași : Editura Artes a Universității de Arte "George Enescu", 2011.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Andrew, Davies. Prin. London : French, 1989.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Prin. Athēna : Hexantas, 1994.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Prun-Pustak. New Delhi : Navyug Publishers, 2011.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Lily, Anamika Huqu. Bishwabhara pran. Dhaka : Anindya, 1991.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Jones, E. Breeze. Adar prin. Pengroes (Caernarfon) : Gwasg Dwyfor, 1985.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Khanpuri, Jagjit Singh. Pran Sangli. Patiala : Panjabi University, 1991.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

John, Arwel. Anifeiliaid prin. Aberystwyth : Canolfan Astudiaethau Addysg Prifysgol Cymru, 2003.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Petre, Zoe, 1940- writer of forword, dir. Prin perdea. Iași : Polirom, 2012.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Goldflam, Arnošt. Vratká prkna. Brno : Větrné mlýny, 2012.

Trouver le texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Plus de sources

Chapitres de livres sur le sujet "PRKN"

Suski, W., et T. Palewski. « PrLn"3S6 ». Dans Pnictides and Chalcogenides II, 1590. Berlin, Heidelberg : Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/10713485_606.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Gooch, Jan W. « Sov Pren ». Dans Encyclopedic Dictionary of Polymers, 683. New York, NY : Springer New York, 2011. http://dx.doi.org/10.1007/978-1-4419-6247-8_10912.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Donato, Dominique M., Steven K. Hanks, Kenneth A. Jacobson, M. P. Suresh Jayasekara, Zhan-Guo Gao, Francesca Deflorian, John Papaconstantinou et al. « Prn-i ». Dans Encyclopedia of Signaling Molecules, 1477. New York, NY : Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4419-0461-4_101088.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Donato, Dominique M., Steven K. Hanks, Kenneth A. Jacobson, M. P. Suresh Jayasekara, Zhan-Guo Gao, Francesca Deflorian, John Papaconstantinou et al. « Prn-p ». Dans Encyclopedia of Signaling Molecules, 1477. New York, NY : Springer New York, 2012. http://dx.doi.org/10.1007/978-1-4419-0461-4_101090.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Newton, Alexandra C. « Protein Kinase C (Prkc) ». Dans Encyclopedia of Signaling Molecules, 4216–22. Cham : Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-67199-4_101822.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Newton, Alexandra C. « Protein Kinase C (Prkc) ». Dans Encyclopedia of Signaling Molecules, 1–6. New York, NY : Springer New York, 2016. http://dx.doi.org/10.1007/978-1-4614-6438-9_101822-1.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Buehren, Jens. « Photorefractive Keratectomy (PRK) ». Dans Encyclopedia of Ophthalmology, 1. Berlin, Heidelberg : Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-35951-4_650-1.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Bühren, Jens. « Photorefractive Keratectomy (PRK) ». Dans Encyclopedia of Ophthalmology, 1374–75. Berlin, Heidelberg : Springer Berlin Heidelberg, 2018. http://dx.doi.org/10.1007/978-3-540-69000-9_650.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Nongmeikapam, Kishorjit, Wahengbam Kanan Kumar et Aheibam Dinamani Singh. « Prn-Sorb-Slam ». Dans Autonomous Driving and Advanced Driver-Assistance Systems (ADAS), 167–92. Boca Raton : CRC Press, 2021. http://dx.doi.org/10.1201/9781003048381-8.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Chríost, Diarmait Mac Giolla. « Waldo Williams Dail Pren (1956) ». Dans Welsh Writing, Political Action and Incarceration, 73–99. London : Palgrave Macmillan UK, 2013. http://dx.doi.org/10.1057/9781137372277_5.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Actes de conférences sur le sujet "PRKN"

Branchi, V., L. Esser, C. Boden, J. Pfeiffer, P. Lingohr, M. Gonzalez-Carmona, S. Manekeller, JC Kalff, M. Toma et H. Matthaei. « Umfassende Expressionsanalyse der Gene PRKN, PINK1 und GLUT1 (Gewebe, Organoidmodell, in silico) zeigt deren Biomarkerpotential im Cholangiokarzinom ». Dans DGVS Digital : BEST OF DGVS. © Georg Thieme Verlag KG, 2020. http://dx.doi.org/10.1055/s-0040-1716277.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Wu, Wenfei, Li Erran Li, Aurojit Panda et Scott Shenker. « PRAN ». Dans HotNets-XIII : The 13th ACM Workshop on Hot Topics in Networks. New York, NY, USA : ACM, 2014. http://dx.doi.org/10.1145/2670518.2673865.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Lozinschii, Mariana, Alina Cutcovschii-Mustuc et Maria Sofronii. « Multiplicarea trandafirului prin virtroculturi ». Dans International Scientific Symposium "Advanced Biotechnologies - Achievements and Prospects". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2020. http://dx.doi.org/10.53040/9789975566957.40.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Melnichuk, S. S., P. P. Ljumarov et V. S. Luniov. « «Pran» Package for Integrated Circuits Simulation ». Dans 2006 8th International Conference on Actual Problems of Electronic Instrument Engineering. IEEE, 2006. http://dx.doi.org/10.1109/apeie.2006.4292565.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Sun, Bo, Jason Kuen, Zhe Lin, Philippos Mordohai et Simon Chen. « PRN : Panoptic Refinement Network ». Dans 2023 IEEE/CVF Winter Conference on Applications of Computer Vision (WACV). IEEE, 2023. http://dx.doi.org/10.1109/wacv56688.2023.00395.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

« Excepts of remarks at Pran Nath Fest ». Dans Proceedings of the 10th International Symposium. World Scientific Publishing Company, 2005. http://dx.doi.org/10.1142/9789812701756_others01.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Ciorchina, Nina, Ion Rosca, Maria Sofronii et Elvira Cuzmina. « Multiplicarea soiului de Maceș Can prin vitroculturi ». Dans International Scientific Symposium "Advanced Biotechnologies - Achievements and Prospects". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2020. http://dx.doi.org/10.53040/9789975566957.27.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Mandic, D. P., et J. A. Chambers. « Advanced PRNN based nonlinear prediction/system identification ». Dans IEE Colloquium on Non-Linear Signal and Image Processing. IEE, 1998. http://dx.doi.org/10.1049/ic:19980446.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Mohananey, Anhad, Katharina Kann et Samuel R. Bowman. « Self-Training for Unsupervised Parsing with PRPN ». Dans Proceedings of the 16th International Conference on Parsing Technologies and the IWPT 2020 Shared Task on Parsing into Enhanced Universal Dependencies. Stroudsburg, PA, USA : Association for Computational Linguistics, 2020. http://dx.doi.org/10.18653/v1/2020.iwpt-1.11.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Cai, Biao, Zhishu Li et Xun Lin. « PRN : A Novel Trust Model ». Dans The First International Symposium on Data, Privacy, and E-Commerce (ISDPE 2007). IEEE, 2007. http://dx.doi.org/10.1109/isdpe.2007.99.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Rapports d'organisations sur le sujet "PRKN"

Dai, Wei. Investigation of the Candidate Tumor Suppressor Gene prk in Prostate Cancer. Fort Belvoir, VA : Defense Technical Information Center, décembre 2001. http://dx.doi.org/10.21236/ada405508.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Dai, Wei, Qi Wang et Suqing Xie. Investigation of the Candidate Tumor Suppressor Gene prk in Prostate Cancer. Fort Belvoir, VA : Defense Technical Information Center, novembre 2002. http://dx.doi.org/10.21236/ada413339.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Miller, Robert E., Thompson II, Baldwin William T., Ivan J. B., Tutt Douglas J., Hiers Ronald C. et Paul L. Prospective Evaluation of Mesopic Night Vision and Night Vision Goggle Visual Acuity After Photorefractive Keratectomy (PRK). Fort Belvoir, VA : Defense Technical Information Center, mars 2005. http://dx.doi.org/10.21236/ada435075.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Thomashow, Linda, Leonid Chernin, Ilan Chet, David M. Weller et Dmitri Mavrodi. Genetically Engineered Microbial Agents for Biocontrol of Plant Fungal Diseases. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7696521.bard.

Texte intégral

Résumé :

The objectives of the project were: a) to construct the site-specific integrative expression cassettes carrying: (i) the chiA gene for a 58-kDa endochitinase, (ii) the pyrrolnitrin biosynthesis operon, and (iii) the acdS gene encoding ACC deaminase; b) to employ these constructs to engineer stable recombinant strains with an expanded repertoire of beneficial activities; c) to evaluate the rhizosphere competence and antifungal activity of the WT and modified strains against pathogenic fungi under laboratory and greenhouse conditions; and d) to monitor the persistence and impact of the introduced strains on culturable and nonculturable rhizosphere microbial populations in the greenhouse and the field. The research generally support our concepts that combining strategically selected genes conferring diverse modes of action against plant pathogens into one organism can improve the efficacy of biological control agents. We hypothesized that biocontrol agents (BCAs) engineered to expand their repertoire of beneficial activities will more effectively control soilborne plant pathogens. In this work, we demonstrated that biocontrol activity of Pseudomonas fluorescens Q8r1-96 and Q2-87, both producing the antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG) effective against the plant pathogenic fungus Rhizoctonia solani, can be improved significantly by introducing and expressing either the 1.6-kb gene chiA, encoding the 58-kDa endochitinase ChiA from the rhizosphere strain SerratiaplymuthicaIC1270, or the 5.8-kb prnABCDoperon encoding the broad-range antibiotic pyrrolnitrin (Prn) from another rhizosphere strain, P. fluorescens Pf-5. The PₜₐcchiAandPₜₐcprnABCDcassettes were cloned into the integrative pBK-miniTn7-ΩGm plasmid, and inserted into the genomic DNA of the recipient bacteria. Recombinant derivatives of strains Q8r1-96 and Q2-87 expressing the PₜₐcchiA or PₜₐcprnABCD cassettes produced endochitinase ChiA, or Prn, respectively, in addition to 2,4-DAPG, and the recombinants gave significantly better biocontrol of R. solani on beans under greenhouse conditions. The disease reduction index increased in comparison to the parental strains Q8r1-96 and Q2-87 to 17.5 and 39.0% from 3.2 and 12.4%, respectively, in the case of derivatives carrying the PₜₐcchiAcassette and to 63.1 and 70% vs. 2.8 and 12,4%, respectively, in the case of derivatives carrying the PₜₐcprnABCDcassette. The genetically modified strains exhibited persistence and non-target effects comparable to those of the parental strains in greenhouse soil. Three integrative cassettes carrying the acdS gene encoding ACC deaminase cloned under the control of different promoters were constructed and tested for enhancement of plant growth promotion by biocontrol strains of P. fluorescens and S. plymuthica. The integrative cassettes constructed in this work are already being used as a simple and efficient tool to improve biocontrol activity of various PGPR bacteria against fungi containing chitin in the cell walls or highly sensitive to Prn. Some parts of the work (e. g., construction of integrative cassettes) was collaborative while other parts e.g., (enzyme and antibiotic activity analyses) were fully synergistic. The US partners isolated and provided to the Israeli collaborators the original biocontrol strains P. fluorescens strains Q8r1-96 and Q2-87 and their mutants deficient in 2,4-DAPG production, which were used to evaluate the relative importance of introduction of Prn, chitinase or ACC deaminase genes for improvement of the biocontrol activity of the parental strains. The recombinant strains obtained at HUJI were supplied to the US collaborators for further analysis.

Styles APA, Harvard, Vancouver, ISO, etc.

Coleman, M. D., et L. Bonsignore. M4R Project - consultancy for element materials technology : summary of consultation regarding implementation of measurement methods CEN/TS 17337:2019 and prEN 16429 for monitoring of pollutants from industrial processes regulated under the Industrial Emissions Directive. National Physical Laboratory, juin 2021. http://dx.doi.org/10.47120/npl.env36.

Texte intégral

Styles APA, Harvard, Vancouver, ISO, etc.

Nous offrons des réductions sur tous les plans premium pour les auteurs dont les œuvres sont incluses dans des sélections littéraires thématiques. Contactez-nous pour obtenir un code promo unique!