939 resultados para Ferrite-Pd reciclável
Resumo:
Two organic–inorganic mixed phase supports were prepared, comprising an alumina filler and polymers of different chemical nature. Four low loaded Pd catalysts were prepared. Good activities and selectivities were obtained during the hydrogenations of styrene, 1-heptyne and 2,3-butanedione. The catalysts were found to have excellent mechanical properties and could be used in applications needing high attrition resistance and crushing strength. In this sense, processes for fine chemicals using slurry reactors or processes for commodities using long packed beds could advantageously use them.
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Organizations are seeking new ideas, tools and methods aiming to improve management process and performance. On the other hand, system performance measurement needs to portray organizational changes and provide managers with a set of true and more appropriate information for the decision-making process. This work aims to propose a performance measurement system in the academic field regarding Research, Development and Innovation (RDI) in the oil and gas industry. The research performed a bibliographic review in a descriptive exploratory manner. A field research was conducted with an expert focus group in order to gather new indicators. As for the validation of these indicators, a survey with experienced professional was also realized. The research surveyed four segments in and outside of the Federal University of Rio Grande do Norte-Brazil such as oil and gas project coordinators, staff at Academic Planning Offices, FUNPEC employees as well as coordinators from Petrobrás. The performance measuring system created from this study features three interrelated performance indicators pointed out as: process indicators, outcome indicators and global indicators. The proposal includes performance indicators that seek to establish more appropriate strategies for effective institution management. It might help policy making of university-industry interaction policies
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El objetivo de este estudio es evaluar la eficacia de los tratamientos más utilizados en infecciones odontogénicas en niños y adolescentes aplicando criterios farmacocinéticos/farmacodinámicos (PK/PD). Se han simulado las curvas de concentración plasmática libre-tiempo a partir de parámetros farmacocinéticos medios de amoxicilina, amoxicilina-ácido clavulánico, cefuroxima axetilo, espiramicina, clindamicina, azitromicina y metronidazol. Para los antibióticos con actividad dependiente del tiempo, se ha calculado el tiempo durante el cual las concentraciones permanecen por encima de la concentración inhibitoria mínima (CIM90) de los microorganismos (T>CIM). Para los antimicrobianos con actividad dependiente de la concentración, se ha calculado el cociente entre el área bajo la curva y la CIM90 (ABC/CIM90). Con amoxicilina-ácido clavulánico (80 mg/kg/día) se han obtenido índices de eficacia adecuados frente a los microorganismos estudiados (T > CIM > 40%), excepto paraVeillonella spp. Clindamicina (40 mg/kg/día) también ha presentado índices PK/PD adecuados frente a la mayoría de los patógenos, excepto Lactobacillus, Actinobacillus actinomycetemcomitans, Peptostreptococcus resistente a penicilina y Eikenella corrodens. Con dosis altas de amoxicilina los resultados no han sido satisfactorios frente a varias especies bacterianas. Con azitromicina y metronidazol no se han alcanzado valores adecuados frente a la mayoría de patógenos (ABC/CIM90 < 25). En conclusión, el tratamiento empírico más adecuado en infecciones odontogénicas en niños y adolescentes es amoxicilina-ácido clavulánico en altas dosis de amoxicilina, aunque se puede utilizar como alternativa clindamicina. Sería conveniente confirmar estos resultados mediante ensayos clínicos, para cuyo diseño y evaluación podría ser de gran utilidad la aplicación de estudios PK/PD.
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Durante il mio periodo di tirocinio mi sono occupato della sintesi e caratterizzazione di cluster carbonilici eterometallici, ed in particolare di cluster Ag-Cu-Fe, Au-Cu-Fe, e Ni-Pd. In un primo momento il lavoro si è concentrato sullo studio della reazione tra cluster Cu-Fe e sali di Ag e Au, con lo scopo di ottenere specie Ag-Cu-Fe, e Au-Cu-Fe. Nella seconda parte l’attività è stata incentrata sulla sintesi di cluster Ni-Pd ad elevata nuclearità, attraverso reazioni tra [Ni6(CO)12]2- e composti di Pd(II). In entrambi i casi le sintesi sono state condotte variando i rapporti stechiometrici dei reagenti e i solventi, permettendo l’ottenimento di specie, caratterizzate spettroscopicamente mediante tecnica IR. In alcuni casi è stato anche possibile ottenere cristalli caratterizzati strutturalmente tramite diffrattometria a raggi X. Le reazioni di [Cu3Fe3(CO)12]3- con quantità crescenti di M=Ag, Au danno luogo alla formazione in sequenza di [Cu5Fe4(CO)16]3-, [MxCu5-xFe4(CO)16]3- (x = 0-5), [M5Fe4(CO)16]3-, [M6Fe4(CO)16]2-. Successivamente, nel caso in cui M= Ag, un ulteriore aggiunta di sali di M+ porta alla formazione di [Ag13Fe8(CO)32]3-, mentre se M= Au si formano i cosiddetti “bruni d’oro” e alla fine, [AuFe4(CO)16]-. Le specie [MxCu5-xFe4(CO)16]3- risultano particolarmente interessanti dato che possono essere viste come leghe molecolari M/Cu, che mostrano disordine sia sostituzionale che composizionale. Per quanto riguarda i cluster Ni-Pd sono state ottenute tre nuove specie carboniliche ad elevata nuclearità, ovvero [Ni37-xPd7+x(CO)48]6- (x= 0,69), [HNi37-xPd7+x(CO)48]5- (x= 0,53) and [Ni22-xPd20+x(CO)48]6- (x = 0.63). In tutte queste strutture il Pd tende ad occupare posizioni che minimizzano le interazioni Pd-CO massimizzando le interazioni M-M, mentre l’opposto risulta per il Ni. Ciò si traduce in una parziale segregazione dei due metalli, anche se alcuni fenomeni di disordine (sostituzionale e composizionale) sono presenti in tali strutture.
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Antimicrobial stewardship programs are gaining more and more relevance in optimizing anti-infective treatment and in preventing the emergence of antimicrobial resistance. Personalization of antimicrobial treatment based on real-time therapeutic drug morning (TDM) and dosing adaptation may represent an important tool in antimicrobial stewardship programs. In this Ph.D project, we aim to focus on differences in pharmacokinetics (PK) for meropenem and piperacillin/tazobactam and host response biomarkers (e.g., C-reactive protein) in severe Gram‐negative related infections occurring in oncohematologic patients. We are interested in identifying optimized model‐based individualized dosing strategies for these antibiotics focusing on biomarkers-guided prediction of PK and pharmacodynamic (PD) parameters using population PK/PD modelling. We expect to identify optimal model‐based dosing targets for these antibiotics for special populations for implementation in TDM routines, and mathematical models characterizing the relationship between biomarkers and outcomes in these populations.
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The aim of the study was to develop a culturally adapted translation of the 12-item smell identification test from Sniffin' Sticks (SS-12) for the Estonian population in order to help diagnose Parkinson's disease (PD). A standard translation of the SS-12 was created and 150 healthy Estonians were questioned about the smells used as response options in the test. Unfamiliar smells were replaced by culturally familiar options. The adapted SS-12 was applied to 70 controls in all age groups, and thereafter to 50 PD patients and 50 age- and sex-matched controls. 14 response options from 48 used in the SS-12 were replaced with familiar smells in an adapted version, in which the mean rate of correct response was 87% (range 73-99) compared to 83% with the literal translation (range 50-98). In PD patients, the average adapted SS-12 score (5.4/12) was significantly lower than in controls (average score 8.9/12), p < 0.0001. A multiple linear regression using the score in the SS-12 as the outcome measure showed that diagnosis and age independently influenced the result of the SS-12. A logistic regression using the SS-12 and age as covariates showed that the SS-12 (but not age) correctly classified 79.0% of subjects into the PD and control category, using a cut-off of <7 gave a sensitivity of 76% and specificity of 86% for the diagnosis of PD. The developed SS-12 cultural adaption is appropriate for testing olfaction in Estonia for the purpose of PD diagnosis.
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Current guidelines have advised against the performance of (131)I-iodide diagnostic whole body scintigraphy (dxWBS) to minimize the occurrence of stunning, and to guarantee the efficiency of radioiodine therapy (RIT). The aim of the study was to evaluate the impact of stunning on the efficacy of RIT and disease outcome. This retrospective analysis included 208 patients with differentiated thyroid cancer managed according to a same protocol and followed up for 12-159 months (mean 30 ± 69 months). Patients received RIT in doses ranging from 3,700 to 11,100 MBq (100 mCi to 300 mCi). Post-RIT-whole body scintigraphy images were performed 10 days after RIT in all patients. In addition, images were also performed 24-48 hours after therapy in 22 patients. Outcome was classified as no evidence of disease (NED), stable disease (SD) and progressive disease (PD). Thyroid stunning occurred in 40 patients (19.2%), including 26 patients with NED and 14 patients with SD. A multivariate analysis showed no association between disease outcome and the occurrence of stunning (p = 0.3476). The efficacy of RIT and disease outcome do not seem to be related to thyroid stunning.
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The aim of this study is to test the feasibility and reproducibility of diffusion-weighted magnetic resonance imaging (DW-MRI) evaluations of the fetal brains in cases of twin-twin transfusion syndrome (TTTS). From May 2011 to June 2012, 24 patients with severe TTTS underwent MRI scans for evaluation of the fetal brains. Datasets were analyzed offline on axial DW images and apparent diffusion coefficient (ADC) maps by two radiologists. The subjective evaluation was described as the absence or presence of water diffusion restriction. The objective evaluation was performed by the placement of 20-mm(2) circular regions of interest on the DW image and ADC maps. Subjective interobserver agreement was assessed by the kappa correlation coefficient. Objective intraobserver and interobserver agreements were assessed by proportionate Bland-Altman tests. Seventy-four DW-MRI scans were performed. Sixty of them (81.1%) were considered to be of good quality. Agreement between the radiologists was 100% for the absence or presence of diffusion restriction of water. For both intraobserver and interobserver agreement of ADC measurements, proportionate Bland-Altman tests showed average percentage differences of less than 1.5% and 95% CI of less than 18% for all sites evaluated. Our data demonstrate that DW-MRI evaluation of the fetal brain in TTTS is feasible and reproducible.
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The over-production of reactive oxygen species (ROS) can cause oxidative damage to a large number of molecules, including DNA, and has been associated with the pathogenesis of several disorders, such as diabetes mellitus (DM), dyslipidemia and periodontitis (PD). We hypothesise that the presence of these diseases could proportionally increase the DNA damage. The aim of this study was to assess the micronucleus frequency (MNF), as a biomarker for DNA damage, in individuals with type 2 DM, dyslipidemia and PD. One hundred and fifty patients were divided into five groups based upon diabetic, dyslipidemic and periodontal status (Group 1 - poor controlled DM with dyslipidemia and PD; Group 2 - well-controlled DM with dyslipidemia and PD; Group 3 - without DM with dyslipidemia and PD; Group 4 - without DM, without dyslipidemia and with PD; and Group 5 - without DM, dyslipidemia and PD). Blood analyses were carried out for fasting plasma glucose, HbA1c and lipid profile. Periodontal examinations were performed, and venous blood was collected and processed for micronucleus (MN) assay. The frequency of micronuclei was evaluated by cell culture cytokinesis-block MN assay. The general characteristics of each group were described by the mean and standard deviation and the data were submitted to the Mann-Whitney, Kruskal-Wallis, Multiple Logistic Regression and Spearman tests. The Groups 1, 2 and 3 were similarly dyslipidemic presenting increased levels of total cholesterol, low density lipoprotein cholesterol and triglycerides. Periodontal tissue destruction and local inflammation were significantly more severe in diabetics, particularly in Group 1. Frequency of bi-nucleated cells with MN and MNF, as well as nucleoplasmic bridges, were significantly higher for poor controlled diabetics with dyslipidemia and PD in comparison with those systemically healthy, even after adjusting for age, and considering Bonferroni's correction. Elevated frequency of micronuclei was found in patients affected by type 2 diabetes, dyslipidemia and PD. This result suggests that these three pathologies occurring simultaneously promote an additional role to produce DNA impairment. In addition, the micronuclei assay was useful as a biomarker for DNA damage in individuals with chronic degenerative diseases.
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We describe herein a general method for the controlled Heck arylation of allylated malonates. Both electron-rich and electron-poor aryldiazonium salts were readily employed as the aryl-transfer agents in good yields and in high chemo-, regio-, and stereoselectivity without formation of decarboxylated byproducts. Reaction monitoring via ESI-MS was used to support the formation of chelated Pd species through the catalytic cycle. Additionally, some Heck adducts were successfully used in the total synthesis of pharmacologically active γ-lactones.
Resumo:
The goal of this cross-sectional observational study was to quantify the pattern-shift visual evoked potentials (VEP) and the thickness as well as the volume of retinal layers using optical coherence tomography (OCT) across a cohort of Parkinson's disease (PD) patients and age-matched controls. Forty-three PD patients and 38 controls were enrolled. All participants underwent a detailed neurological and ophthalmologic evaluation. Idiopathic PD cases were included. Cases with glaucoma or increased intra-ocular pressure were excluded. Patients were assessed by VEP and high-resolution Fourier-domain OCT, which quantified the inner and outer thicknesses of the retinal layers. VEP latencies and the thicknesses of the retinal layers were the main outcome measures. The mean age, with standard deviation (SD), of the PD patients and controls were 63.1 (7.5) and 62.4 (7.2) years, respectively. The patients were predominantly in the initial Hoehn-Yahr (HY) disease stages (34.8% in stage 1 or 1.5, and 55.8 % in stage 2). The VEP latencies and the thicknesses as well as the volumes of the retinal inner and outer layers of the groups were similar. A negative correlation between the retinal thickness and the age was noted in both groups. The thickness of the retinal nerve fibre layer (RNFL) was 102.7 μm in PD patients vs. 104.2 μm in controls. The thicknesses of retinal layers, VEP, and RNFL of PD patients were similar to those of the controls. Despite the use of a representative cohort of PD patients and high-resolution OCT in this study, further studies are required to establish the validity of using OCT and VEP measurements as the anatomic and functional biomarkers for the evaluation of retinal and visual pathways in PD patients.
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Nanorap is a new nanotechnological formulation for topical anesthesia composed of lidocaine (2.5%) and prilocaine (2.5%). The present study evaluated the pharmacokinetics (PK) of Nanorap. For the determination of lidocaine and prilocaine in human plasma a new method using high-performance liquid-chromatography coupled to tandem mass spectrometry was developed. Nanorap pharmacodynamic (PD) and its physical proprieties were also evaluated. Nanorap was administered by topical application of 2g to healthy volunteers and blood samples were collected for the PK analysis. The drugs were extracted from plasma by liquid-liquid extraction with ether/hexane (80/20, v/v). The chromatography separation was performed on a Genesis C18 analytical column 4 µm (100 x 2.1 mm i.d.) with a mobile phase of methanol/acetonitrile/water (40/30/30, for lidocaine, and 50/30/20, for prilocaine, v/v/v) + 2 mM of ammonium acetate and ropivacaine as internal standard. The drugs were quantified using a mass spectrometer with an electrospray source in the ESI positive mode (ES+) configured for multiple reaction monitoring. The PD of Nanorap was evaluated with the use of a visual analogue scale. Nanorap was characterized by cryofracture. The chromatography run time was 5.5 min for lidocaine and 3.3 min for prilocaine and the lower limit of quantification was 0.05 ng/mL for both drugs. Mean Cmax was 6.62 and 1.72 ng/mL for lidocaine and prilocaine, respectively. Median Tmax was 6.5 hours for both drugs. Nanocapsules had a mean size of 88nm and mean drug association of 92.5% and 89% for lidocaine and prilocaine, respectively. The PD study showed that Nanorap has a sufficient analgesic effect (>30% reduction in pain) after 10 minutes of application. A new simple, selective and sensitive method for determination of lidocaine and prilocaine in human plasma was developed. Nanorap generated safe plasma levels of the drugs and satisfactory analgesic effect.