964 resultados para Center of resistance


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A classic way of delaying drug resistance is to use an alternative when possible. We tested the malaria treatment Argemone mexicana decoction (AM), a validated self-prepared traditional medicine made with one widely available plant and safe across wide dose variations. In an attempt to reflect the real situation in the home-based management of malaria in a remote Malian village, 301 patients with presumed uncomplicated malaria (median age 5 years) were randomly assigned to receive AM or artesunate-amodiaquine [artemisinin combination therapy (ACT)] as first-line treatment. Both treatments were well tolerated. Over 28 days, second-line treatment was not required for 89% (95% CI 84.1-93.2) of patients on AM, versus 95% (95% CI 88.8-98.3) on ACT. Deterioration to severe malaria was 1.9% in both groups in children aged </=5 years (there were no cases in patients aged >5 years) and 0% had coma/convulsions. AM, now government-approved in Mali, could be tested as a first-line complement to standard modern drugs in high-transmission areas, in order to reduce the drug pressure for development of resistance to ACT, in the management of malaria. In view of the low rate of severe malaria and good tolerability, AM may also constitute a first-aid treatment when access to other antimalarials is delayed.

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In this study we observe the poisoning effect of S to the adsorption and dissociation of 02 molecule on Pd surfaces. To perform this study we used Viennaab initio Simulation Package (VASP) and Spanish Initiative for Electronic structure with thousands of Atoms (SIESTA) ab initio softwares. To describe all Pd surfaces we selected the (100), and (211) surfaces, because we need very reactive and simple surfaces. Before studying the poison¬ing effect of S we had to study the dissociation of 02 on the surfaces. We discovered that on the (100) surface the hollow site is the most reactive site, but at room temperature the steric hinderace effect occurs very easily. If the molecule has enough vibrational energyit will dissociate. On the (211) surface the (100) micro facet's hollow site is the most reactive site and the molecule dissociates in the site without any barrier, and the molecule drifts from the terrace to this site. An S atom sticks on the Pd (100) surface in the hollow site. It affects the d-band density of states of the nearests Pd atoms; It moves the center of the d-band downin energy, when the bond between the Pd atom and the 0 atom is more antibonding. In the hollow site the S atom also blocks the dissociation site of the molecule. On the Pd(211) surface the energetically favourable site of the S atom is the(100) microfacet's hollow site. There it blocks the most reactive site, but its effect to the Pd atoms next to it is not significant.

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Spontaneous mutants resistant to fluoroquinolones were obtained by exposing Serratia marcescens NIMA (wild-type strain) to increasing concentrations of ciprofloxacin both in liquid and on solid media. Frequencies of mutation ranged from 10-7 to 10-9. Active expulsion of antibiotic was explored as a possible mechanism of resistance in mutants as well as changes in topoisomerase target genes. The role of extrusion mechanisms in determining the emergence of multidrug-resistant bacteria was also examined. Mutants resistant to high concentrations of fluoroquinolones had a single mutation in their gyrA QRDR sequences, whereas the moderate resistance in the rest of mutants was due to extrusion of the drug

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Spontaneous mutants resistant to fluoroquinolones were obtained by exposing Serratia marcescens NIMA (wild-type strain) to increasing concentrations of ciprofloxacin both in liquid and on solid media. Frequencies of mutation ranged from 10-7 to 10-9. Active expulsion of antibiotic was explored as a possible mechanism of resistance in mutants as well as changes in topoisomerase target genes. The role of extrusion mechanisms in determining the emergence of multidrug-resistant bacteria was also examined. Mutants resistant to high concentrations of fluoroquinolones had a single mutation in their gyrA QRDR sequences, whereas the moderate resistance in the rest of mutants was due to extrusion of the drug

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Eight patients with colloid cysts of the third ventricle were examined with CT and MR. In six, surgical resection was performed and the material was subjected to histologic evaluation; the concentrations of trace elements were determined by particle-induced X-ray emission. Stereotaxic aspiration was performed in two. The investigation showed that colloid cysts are often iso- or hypodense relative to brain on CT (5/8), but sometimes have a center of increased density. Increased density did not correlate with increased concentration of calcium or other metals but did not correlate with high cholesterol content. Colloid cysts appear more heterogeneous on MR (6/8) than on CT (3/8), despite a homogeneous appearance at histology. High signal on short TR/TE sequences is correlated with a high cholesterol content. A marked shortening of the T2 relaxation time is often noticed in the central part of the cyst. Analysis of trace elements showed that this phenomenon is not related to the presence of metals with paramagnetic effects. Our analysis of the contents of colloid cysts does not support the theory that differing metallic concentrations are responsible for differences in MR signal intensity or CT density. We did find that increased CT density and high MR signal correlated with high cholesterol content.

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Empirical antibiotic therapy of community-acquired pneumonia (CAP) has been complicated by the worldwide emergence of penicillin resistance among Streptococcus pneumoniae. The impact of this resistance on the outcome of patients hospitalized for CAP, empirically treated with betalactams, has not been evaluated in a randomized study. We conducted a prospective, randomized trial to assess the efficacy of amoxicillin-clavulanate (2 g/200 mg/8 hr) and ceftriaxone (1 g/24 hr) in a cohort of patients hospitalized for moderate-to-severe CAP. Three-hundred seventy-eight patients were randomized to receive amoxicillin-clavulanate (184 patients) or ceftriaxone (194 patients). Efficacy was assessed on Day 2, after completion of therapy and at long term follow-up. There were no significant differences in outcomes between treatment groups, both in intention-to-treat and per-protocol analysis. Overall mortality was 10.3% for amoxicillin-clavulanate and 8.8% for ceftriaxone (NS). There were 116 evaluable patients with proven pneumococcal pneumonia. Rates of high-level penicillin resistance (MIC of penicillin ≥2 µg/mL) were similar in the two groups (8.2 and 10.2%). Clinical efficacy at the end of therapy was 90.6% for amoxicillin-clavulanate and 88.9% for ceftriaxone (95% C.I. of the difference: -9.3 to +12.7%). No differences in outcomes were attributable to differences in penicillin susceptibility of pneumococcal strains. Sequential i.v./oral amoxicillin-clavulanate and parenteral ceftriaxone were equally safe and effective for the empirical treatment of acute bacterial pneumonia, including penicillin and cephalosporin-resistant pneumococcal pneumonia. The use of appropriate betalactams in patients with penumococcal pneumonia and in the overall CAP population, is reliable at the current level of resistance

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This study investigated behavioral adaptability, which could be defined as a blend between stability and flexibility of the limbs movement and their inter-limb coordination, when individuals received informational constraints. Seven expert breaststroke swimmers performed three 200-m in breaststroke at constant submaximal intensity. Each trial was performed randomly in a different coordination pattern: 'freely-chosen', 'maximal glide' and 'minimal glide'. Two underwater and four aerial cameras enabled 3D movement analysis in order to assess elbow and knee angles, elbow-knee pair coordination, intra-cyclic velocity variations of the center of mass, stroke rate and stroke length and inter-limb coordination. The energy cost of locomotion was calculated from gas exchanges and blood lactate concentration. The results showed significantly higher glide, intra-cyclic velocity variations and energy cost under 'maximal glide' compared to 'freely-chosen' instructional conditions, as well as higher reorganization of limb movement and inter-limb coordination (p<0.05). In the 'minimal glide' condition, the swimmers did not show significantly shorter glide and lower energy cost, but they exhibited significantly lower deceleration of the center of mass, as well as modified limb movement and inter-limb coordination (p<0.05). These results highlight that a variety of structural adaptations can functionally satisfy the task-goal.

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The gold mineralization of the Hutti Mine is hosted by nine parallel, N - S trending, steeply dipping, 2 - 10 m wide shear zones, that transect Archaean amphibolites. The shear zones were formed after peak metamorphism during retrograde ductile D, shearing in the lower amphibolite facies. They were reactivated in the lower to mid greenschist facies by brittle-ductile D-3 shearing and intense quartz veining. The development of a S-2-S-3 crenulation cleavage facilitates the discrimination between the two deformation events and contemporaneous alteration and gold mineralization. Ductile D, shearing is associated with a pervasively developed distal chlorite - sed cite alteration assemblage in the outer parts of the shear zones and the proximal biotite-plagioclase alteration in the center of the shear zones. D3 is characterized by development of the inner chlorite-K-feldspar alteration, which forms a centimeter-scale alteration halo surrounding the laminated quartz veins and replaces earlier biotite along S-3. The average size of the laminated vein systems is 30-50 m along strike as well as down-dip and 2-6 m in width. Mass balance calculations suggest strong metasomatic changes for the proximal biotite-plagioclase alteration yielding mass and volume increase of ca. 16% and 12%, respectively. The calculated mass and volume changes of the distal chlorite-sericite alteration (ca. 11%, ca. 8%) are lower. The decrease in 6180 values of the whole rock from around 7.5 parts per thousand for the host rocks to 6-7 parts per thousand for the distal chlorite-sericite and the proximal biotite-plagioclase alteration and around 5 parts per thousand for the inner chlorite-K-feldspar alteration suggests hydrothermal alteration during two-stage deformation and fluid flow. The ductile D-2 deformation in the lower amphibolite facies has provided grain scale porosities by microfracturing. The pervasive, steady-state fluid flow resulted in a disseminated style of gold-sulfide mineralization and a penetrative alteration of the host rocks. Alternating ductile and brittle D3 deformation during lower to mid greenschist facies conditions followed the fault-valve process. Ductile creep in the shear zones resulted in a low permeability environment leading to fluid pressure build-up. Strongly episodic fluid advection and mass transfer was controlled by repeated seismic fracturing during the formation of laminated quartz(-gold) veins. The limitation of quartz veins to the extent of earlier shear zones indicate the importance of preexisting anisotropies for fault-valve action and economic gold mineralization. (C) 2003 Elsevier B.V. All rights reserved.

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Productivity and profitability are important concepts and measures describing the performance and success of a firm. We know that increase in productivity decreases the costs per unit produced and leads to better profitability. This common knowledge is not, however, enough in the modern business environment. Productivity improvement is one means among others for increasing the profitability of actions. There are many means to increase productivity. The use of these means presupposes operative decisions and these decisions presuppose informationabout the effects of these means. Productivity improvement actions are in general made at floor level with machines, cells, activities and human beings. Profitability is most meaningful at the level of the whole firm. It has been very difficult or even impossible to analyze closely enough the economical aspects of thechanges at floor level with the traditional costing systems. New ideas in accounting have only recently brought in elements which make it possible to considerthese phenomena where they actually happen. The aim of this study is to supportthe selection of objects to productivity improvement, and to develop a method to analyze the effects of the productivity change in an activity on the profitability of a firm. A framework for systemizing the economical management of productivity improvement is developed in this study. This framework is a systematical way with two stages to analyze the effects of productivity improvement actions inan activity on the profitability of a firm. At the first stage of the framework, a simple selection method which is based on the worth, possibility and the necessity of the improvement actions in each activity is presented. This method is called Urgency Analysis. In the second stage it is analyzed how much a certain change of productivity in an activity affects the profitability of a firm. A theoretical calculation model with which it is possible to analyze the effects of a productivity improvement in monetary values is presented. On the basis of this theoretical model a tool is made for the analysis at the firm level. The usefulness of this framework was empirically tested with the data of the profit center of one medium size Finnish firm which operates in metal industry. It is expressedthat the framework provides valuable information about the economical effects of productivity improvement for supporting the management in their decision making.

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Työn tärkeimpänä tavoitteena oli edistää ympäristöjärjestelmän laatimista Kvaerner Pulping, Power divisioonan Kattilat-liiketoimintayksikölle. Lisäksi tavoitteena oli tarkastella yritykseen kohdistuvia ympäristövaatimuksia ja niiden vaikutusta yrityksen toimintaan. Aluksi työssä tarkasteltiin ympäristöjärjestelmästandardien sisältöjä ja niiden eroja. Työssä käsiteltiin myös erilaisia elinkaarijohtamisen malleja, joita voidaan hyödyntää yrityksen kokonaisvaltaisessa ympäristöjärjestelmässä. Työssä tarkasteltiin myös sidosryhmien vaikutusta yrityksen ympäristötoimintaan. Kattilalaitostoimittajan tärkeimpiä asiakkaita ovat sellu- ja paperiteollisuus. Näihin yrityksiin on kohdistunut runsaan kymmenen vuoden aikana paineita ympäristötoiminnan tehostamiseksi. Tämän kehityksen seurauksena vastaavat tehostamispaineet ovat siirtymässä myös alihankkijoille, kuten kattilaitostoimittajille. Tehokkaan ympäristöjohtamisen takaamiseksi työssä määriteltiin ympäristövastuut ja –valtuudet sekä ympäristöpäämäärät ja –tavoitteet. Lisäksi tunnistettiin yrityksen toimintaan liittyvät ympäristönäkökohdat ja –riskit. Työn yhteydessä laadittiin ympäristöjärjestelmän luonnos, ja se sisältää jatkuvan parantamisen periaatteen. Työn yhteydessä laadittiin lisäksi Kvaerner Pulping Oy:n koelaitokselle ympäristölupahakemus. Työssä on kuvattu koelaitosta ja sen ympäristölupahakemukseen liittyviä asioita esimerkkinä parantuneesta ympäristöasioiden hoidosta.

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We have studied the abrupt and hysteretic changes of resistance in MgO-based capacitor devices. The switching behavior is discussed in terms of the formation and rupture of conduction filaments due to the migration of structural defects in the electric field, together with the redox events which affects the mobile carriers. The results presented in this paper suggest that MgO transparent films combining ferromagnetism and multilevel switching characteristics might pave the way for a new method for spintronic multibit data storage.

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Blood culture remains the best approach to identify the incriminating microorganisms when a bloodstream infection is suspected, and to guarantee that the antimicrobial treatment is adequate. Major improvements have been made in the last years to increase the sensitivity and specificity and to reduce the time to identification of microorganisms recovered from blood cultures. Among other factors, the introduction in clinical microbiology laboratories of the matrix-assisted laser desorption ionization time-of-flight mass spectrometry technology revolutionized the identification of microorganisms whereas the introduction of nucleic-acid-based methods, such as DNA hybridization or rapid PCR-based test, significantly reduce the time to results. Together with traditional antimicrobial susceptibility testing, new rapid methods for the detection of resistance mechanisms respond to major epidemiological concerns such as methicillin-resistant Staphylococcus aureus, extended-spectrum β-lactamase or carbapenemases. This review presents and discusses the recent developments in microbial diagnosis of bloodstream infections based on blood cultures.

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The hypothesis that constitutive and inducible plant resistance against herbivores should trade-off because they use the same resources and impose costs to plant fitness has been postulated for a long time. Negative correlations between modes of deployment of resistance and defences have been observed across and within species in common garden experiments. It was therefore tested whether that pattern of resistance across genotypes follows a similar variation in patterns of gene expression and chemical defence production. Using the genetically tractable model Arabidopsis thaliana and different modes of induction, including the generalist herbivore Spodoptera littoralis, the specialist herbivore Pieris brassicae, and jasmonate application, constitutive and inducibility of resistance was measured across seven A. thaliana accessions that were previously selected based on constitutive levels of defence gene expression. According to theory, it was found that modes of resistance traded-off among accessions, particularly against S. littoralis, in which accessions investing in high constitutive resistance did not increase it substantially after attack and vice-versa. Accordingly, the average expression of eight genes involved in glucosinolate production negatively predicted larval growth across the seven accessions. Glucosinolate production and genes related to defence induction on healthy and herbivore-damaged plants were measured next. Surprisingly, only a partial correlation between glucosinolate production, gene expression, and the herbivore resistance results was found. These results suggest that the defence outcome of plants against herbivores goes beyond individual molecules or genes but stands on a complex network of interactions.

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Tämä diplomityö esittelee 1.6. - 4.11.2002 Mikkelin ammattikorkeakoulun YTI-tutkimuskeskuksen Informaatio- ja mediateknologian hankekokonaisuuden STRIMT-projektin puitteissa tekemäni MHP-kehitysjärjestelmähankinnan tuloksia. Digitaalitelevision MHP-sovelluskehitysjärjestelmän hankinnan tulosten lisäksi työ antaa yleiskuvan MHP-sovelluskehitystyökaluista, digitaalitelevisiostandardeista sekä digitaalitelevisioverkkojen yhteistoimintamalleista televerkkojen kanssa. Keräämieni tietojen, tekemäni tarvemäärittelyn ja suorittamani tuotevertailun perusteella valitsin tarpeisiimme sopivimmaksi järjestelmäksi Alticast Inc.-yrityksen Altifusion-tuotteen. Tuotteen valinnassa otin huomioon myös mahdolliset tulevaisuuden tarpeet aina täysimittaista lähetysjärjestelmää varten kehittämällä vaiheittaisen hankintasuunnitelman. Järjestelmää hankittaessa tärkeintä on huomioida heti alusta alkaen mahdolliset tulevat tarpeet ja varmistaa hankinnan hyödynnettävyys myös tulevaisuudessa. Järjestelmän hankinnan lisäksi vastasin sen käyttöönotosta ja järjestelmää hyödyntävän testisovelluksen laatimisesta.

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We investigate the spatial dependence of the exciton lifetimes in single ZnO nanowires. We have found that the free exciton and bound exciton lifetimes exhibit a maximum at the center of nanowires, while they decrease by 30% towards the tips. This dependence is explained by considering the cavity-like properties of the nanowires in combination with the Purcell effect. We show that the lifetime of the bound-excitons scales with the localization energy to the power of 3/2, which validates the model of Rashba and Gurgenishvili at the nanoscale.