929 resultados para Relevant expressions
Resumo:
The conversion of cellular prion protein (PrPc), a GPI-anchored protein, into a protease-K-resistant and infective form (generally termed PrPsc) is mainly responsible for Transmissible Spongiform Encephalopathies (TSEs), characterized by neuronal degeneration and progressive loss of basic brain functions. Although PrPc is expressed by a wide range of tissues throughout the body, the complete repertoire of its functions has not been fully determined. Recent studies have confirmed its participation in basic physiological processes such as cell proliferation and the regulation of cellular homeostasis. Other studies indicate that PrPc interacts with several molecules to activate signaling cascades with a high number of cellular effects. To determine PrPc functions, transgenic mouse models have been generated in the last decade. In particular, mice lacking specific domains of the PrPc protein have revealed the contribution of these domains to neurodegenerative processes. A dual role of PrPc has been shown, since most authors report protective roles for this protein while others describe pro-apoptotic functions. In this review, we summarize new findings on PrPc functions, especially those related to neural degeneration and cell signaling.
Resumo:
Invasive mold infections are life-threatening diseases for which appropriate antifungal therapy is crucial. Their epidemiology is evolving, with the emergence of triazole-resistant Aspergillus spp. and multidrug-resistant non-Aspergillus molds. Despite the lack of interpretive criteria, antifungal susceptibility testing of molds may be useful in guiding antifungal therapy. The standard broth microdilution method (BMD) is demanding and requires expertise. We assessed the performance of a commercialized gradient diffusion method (Etest method) as an alternative to BMD. The MICs or minimal effective concentrations (MECs) of amphotericin B, voriconazole, posaconazole, caspofungin, and micafungin were assessed for 290 clinical isolates of the most representative pathogenic molds (154 Aspergillus and 136 non-Aspergillus isolates) with the BMD and Etest methods. Essential agreements (EAs) within ±2 dilutions of ≥90% between the two methods were considered acceptable. EAs for amphotericin B and voriconazole were >90% for most potentially susceptible species. For posaconazole, the correlation was acceptable for Mucoromycotina but Etest MIC values were consistently lower for Aspergillus spp. (EAs of <90%). Excellent EAs were found for echinocandins with highly susceptible (MECs of <0.015 μg/ml) or intrinsically resistant (MECs of >16 μg/ml) strains. However, MEC determinations lacked consistency between methods for strains exhibiting mid-range MECs for echinocandins. We concluded that the Etest method is an appropriate alternative to BMD for antifungal susceptibility testing of molds under specific circumstances, including testing with amphotericin B or triazoles for non-Aspergillus molds (Mucoromycotina and Fusarium spp.). Additional study of molecularly characterized triazole-resistant Aspergillus isolates is required to confirm the ability of the Etest method to detect voriconazole and posaconazole resistance among Aspergillus spp.
Resumo:
Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways.
Resumo:
Actualment, vivim en una societat on hi conviuen diferents cultures i la música és un llenguatge que s’utilitza en totes elles. Aquest treball tractarà el tema de la música i la multiculturalitat a l’aula per investigar si és possible, a partir de la música dels diferents països d’origen dels infants, conèixer-se millor i conèixer millor als companys. Com a mestres hem de tenir en compte totes les cultures de la nostra aula per tal d’ajudar als infants a respectar i valorar cada una d’elles. En aquesta investigació trobarem quina ha estat la metodologia d’estudi, quina ha estat la intervenció a l’aula i quins són els resultats que hem obtingut.
Resumo:
A literature review and pictorial essay were developed to discuss the importance of knowing the main findings and locations of otosclerosis at multidetector computed tomography (MDCT). The authors performed a retrospective review of cases of otosclerosis diagnosed in their institution by means of high resolution multidetector computed tomography. Otosclerosis corresponds to otic capsule dysplasia characterized by metabolic derangement of its endochondral layer. Such condition constitutes a relevant cause of sensorineural hearing loss, affecting about 7% to 10% of the general population. The diagnosis is usually clinical, but imaging methods play a significant role in the anatomical detailing, differential diagnosis, surgical planning and evaluation of postoperative complications. Among such methods, the relevance of MDCT is highlighted. Radiologists should be familiar with the MDCT findings of otosclerosis, as well as with the temporal bone anatomy to assist in the appropriate clinical management of this disease.
Resumo:
Resistance to semi-dry environments has been considered a crucial trait for superior growth and survival of strains used for bioaugmentation in contaminated soils. In order to compare water stress programmes, we analyse differential gene expression among three phylogenetically different strains capable of aromatic compound degradation: Arthrobacter chlorophenolicus A6, Sphingomonas wittichii RW1 and Pseudomonas veronii 1YdBTEX2. Standardized laboratory-induced water stress was imposed by shock exposure of liquid cultures to water potential decrease, induced either by addition of solutes (NaCl, solute stress) or by addition of polyethylene glycol (matric stress), both at absolute similar stress magnitudes and at those causing approximately similar decrease of growth rates. Genome-wide differential gene expression was recorded by micro-array hybridizations. Growth of P. veronii 1YdBTEX2 was the most sensitive to water potential decrease, followed by S. wittichii RW1 and A. chlorophenolicus A6. The number of genes differentially expressed under decreasing water potential was lowest for A. chlorophenolicus A6, increasing with increasing magnitude of the stress, followed by S. wittichii RW1 and P. veronii 1YdBTEX2. Gene inspection and gene ontology analysis under stress conditions causing similar growth rate reduction indicated that common reactions among the three strains included diminished expression of flagellar motility and increased expression of compatible solutes (which were strain-specific). Furthermore, a set of common genes with ill-defined function was found between all strains, including ABC transporters and aldehyde dehydrogenases, which may constitute a core conserved response to water stress. The data further suggest that stronger reduction of growth rate of P. veronii 1YdBTEX2 under water stress may be an indirect result of the response demanding heavy NADPH investment, rather than the presence or absence of a suitable stress defence mechanism per se.
Resumo:
The aim of this study was to prospectively assess the prevalence of orthoptic anomalies following conservative management of pure blowout orbital fractures and to evaluate their clinical relevance. Clinical and radiologic data of patients with unilateral conservatively managed pure blowout orbital fractures with a minimum follow-up of 6 months were reviewed. Eligible patients were contacted and invited to undergo an extended ophthalmologic examination as follows: distance and near visual acuities, Hertel exophthalmometry, corneal light reflex (Hirschberg test), ductions and versions in the 6 cardinal fields of gaze, eye deviation with prisms and alternate cover test in all of the 9-gaze directions with Maddox rod, degrees of incyclo/excyclotorsion with right and left eye fixation, horizontal and vertical deviation with Hess-Weiss coordimetry, degree of horizontal/vertical and incyclo/excyclotorsion deviation with Harms wall deviometry, and vertical deviation with Bielschowsky head-tilt test. Of the 69 patients contacted, 49 declined to participate given that they were asymptomatic. Twenty patients agreed to undergo the examination. One patient complained of minimal double vision limited to the extreme downgaze. Four patients had asymptomatic ocular motility disturbances limited to the extreme gaze. Seven patients had asymptomatic horizontal heterophoria. These disturbances did not interfere with daily or professional activities in any of the patients. The current study demonstrated that conservative management of pure orbital blowout fractures can result in orthoptic anomalies. These sequelae were restricted to a very limited portion of the binocular field of the vision and were not found to be clinically relevant.
Resumo:
In the present chapter some prototype gas and gas-surface processes occurring within the hypersonic flow layer surrounding spacecrafts at planetary entry are discussed. The discussion is based on microscopic dynamical calculations of the detailed cross sections and rate coefficients performed using classical mechanics treatments for atoms, molecules and surfaces. Such treatment allows the evaluation of the efficiency of thermal processes (both at equilibrium and nonequilibrium distributions) based on state-to-state and state specific calculations properly averaged over the population of the initial states. The dependence of the efficiency of the considered processes on the initial partitioning of energy among the various degrees of freedom is discussed.
Resumo:
The aim of this report is to classify analytical methods based on flowing media and to define (standardize) terminology. After the classification and a discussion of terms describing the systems and component parts, a section is devoted to terms describing the performance of flow systems. The list of terms included is restricted to the most relevant ones; especially "self-explanatory" terms are left out. It is emphasised that the usage of terms or expressions that do not adequately describe the processes or procedures involved should be strongly discouraged. Although belonging to the category of methods based on flowing media, chromatographic methods are not comprised in the present document. However, care has been taken that the present text is not in conflict with definitions in that domain. In documents in which flow methods are described, it should be clearly indicated how the sample and/or reagent is introduced and how the sample zone is transported. When introducing new techniques in the field, or variants of existing techniques, it is strongly recommended that descriptive terms rather than trivial or elaborate names are used.
Detailed crystallization study of co-precipitated Y1.47Gd1.53Fe5O12 and relevant magnetic properties
Resumo:
The crystallization process of co-precipitated Y1.5Gd1.5Fe5O12 powder heated up to 1000 ºC at rate of 5 °C min-1 was investigated. Above 810 ºC crystalline Y1.47Gd1.53Fe5O12 was obtained with a lattice parameter of 12.41 Å and a theoretical density of 5.84 g cm-3. Dry pressed rings were sintered at 1270 and 1320 ºC, increasing the grain-size from 3.1 to 6.5 µm, the theoretical density by 87.6 to 95.3% and decreasing Hc from 2.9725 to 1.4005 Oe. Additionally, Hc increased when the frequency of the hysteresis graph varied from 60 Hz to 10 kHz, the curie temperature was 282.4 ºC and Ms equalled 9.25 emu g-1 (0.17 kG) agreeing well with the Bs-value of the hysteresis graph and literature values.
Resumo:
A historiographical study of Jane Marcet’s role in spreading chemistry knowledge to a wider audience in the 19th century is presented here. Her efforts to spread scientific knowledge were crucial to sharing the most important theories of chemistry among different audiences, particularly women and young people. Through her book, “Conversations on Chemistry,” which was published in several editions from 1806 to 1853, she contributed significantly to chemistry education. Despite controversy over the large number of editions, this text is a strong witness to the active participation of women in science. Her scientific rigor and contribution to narrative strategies in chemistry pedagogy have given Jane Marcet consideration not only as an important woman in the scientific community of England during the first half of the 19th century but also as a central figure in the early development of chemistry diffusion and education.
Resumo:
Den rikt utformade och komplexa hinduiska traditionen har hittills huvudsakligen tecknats av manliga forskare och det är främst manliga religiösa strävanden som har dokumenterats. Detta förhållande och de patriarkala synsätt som styr många auktoritativa heliga texter har bidragit till att skapa intrycket att hinduiska kvinnors religiösa erfarenheter antingen saknas eller är avsevärt begränsade. Denna studie lyfter fram det faktum att ett ökande antal indiska kvinnor inom dagens hinduism axlar publika roller som religiösa ledare. Med sitt framträdande utmanar många av dessa rådande sociala uppfattningar om kvinnors underordnade ställning och främjar därmed en förnyad medvetenhet av urgamla föreställningar om Gud som kvinna. Avhandlingen utforskar fenomenet kvinnliga guruer genom att belysa sjuttio guruers andliga karriär, med särskild fokus på fyra av dem. Några av de frågor som behandlas är följande: På vilket sätt är kvinnliga guruer del av den hinduiska traditionen? Vilka förväntningar ställs på dem? Hur legitimeras deras auktoritet som guruer? Hur handskas guruerna med sina dubbla roller som kvinnor och andliga ledare? Hur återspeglas gudinnans ställning, som i indisk religiositet ofta är central, i kvinnors faktiska verklighet? Bidrar kvinnliga guruer med sitt religiösa engagemang till att nyskapa och förändra den indiska religiösa diskursen och utövningen av religion?
Resumo:
Objective: to discuss the participation of Plastic Surgery in the reconstruction of the chest wall, highlighting relevant aspects of interdisciplinaryness. Methods: we analyzed charts from 20 patients who underwent extensive resection of the thoracic integument, between 2000 and 2014, recording the indication of resection, the extent and depth of the raw areas, types of reconstructions performed and complications. Results: among the 20 patients, averaging 55 years old, five were males and 15 females. They resections were: one squamous cell carcinoma, two basal cell carcinomas, five chondrosarcomas and 12 breast tumors. The extent of the bloody areas ranged from 4x9 cm to 25x40 cm. In 12 patients the resection included the muscular plane. In the remaining eight, the tumor removal achieved a total wall thickness. For reconstruction we used: one muscular flap associated with skin grafting, nine flaps and ten regional fasciocutaneous flaps. Two patients undergoing reconstruction with fasciocutaneous flaps had partially suffering of the flap, solved with employment of a myocutaneous flap. The other patients displayed no complications with the techniques used, requiring only one surgery. Conclusion: the proper assessment of local tissues and flaps available for reconstruction, in addition to the successful integration of Plastic Surgery with the specialties involved in the treatment, enable extensive resections of the chest wall and reconstructions that provide patient recovery.
Resumo:
Most cells exchange ions and small metabolites via gap junction channels. These channels are made of two hemichannels (connexons), each formed by the radial arrangement of six connexin (Cx) proteins. Connexins span the bilayer four times (M1-M4) and have both amino- and carboxy-termini (NT, CT) at the cytoplasmic side of the membrane, forming two extracellular loops (E1, E2) and one inner (IL) loop. The channels are regulated by gates that close with cytosolic acidification (e.g., CO2 treatment) or increased calcium concentration, possibly via calmodulin activation. Although gap junction regulation is still unclear, connexin domains involved in gating are being defined. We have recently focused on the CO2 gating sensitivity of Cx32, Cx38 and various mutants and chimeras expressed in Xenopus oocytes and studied by double voltage clamp. Cx32 is weakly sensitive to CO2, whereas Cx38 is highly sensitive. A Cx32 chimera containing the second half of the inner loop (IL2) of Cx38 was as sensitive to CO2 as Cx38, indicating that this domain plays an important role. Deletion of CT by 84% did not affect CO2 sensitivity, but replacement of 5 arginines (R) with sparagines (N) at the beginning of CT (C1) greatly enhanced the CO2 sensitivity of Cx32. This suggests that whereas most of CT is irrelevant, positive charges of C1 maintain the CO2 sensitivity of Cx32 low. As a hypothesis we have proposed a model that involves charge interaction between negative residues of the beginning of IL1 and positive residues of either C1 or IL2. Open and closed channels would result from IL1-C1 and IL1-IL2 interactions, respectively