67 resultados para Materials and process characterization


Relevância:

100.00% 100.00%

Publicador:

Resumo:

IT has turned out to be a key factor for the purposes of gaining maturity in Business Process Management (BPM). This book presents a worldwide investigation that was conducted among companies from the ‘Forbes Global 2000’ list to explore the current usage of software throughout the BPM life cycle and to identify the companies’ requirements concerning process modelling. The responses from 130 companies indicate that, at the present time, it is mainly software for process description and analysis that is required, while process execution is supported by general software such as databases, ERP systems and office tools. The resulting complex system landscapes give rise to distinct requirements for BPM software, while the process modelling requirements can be equally satisfied by the most common languages (BPMN, UML, EPC).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

During the last decade, medical education in the German-speaking world has been striving to become more practice-oriented. This is currently being achieved in many schools through the implementation of simulation-based instruction in Skills Labs. Simulators are thus an essential part of this type of medical training, and their acquisition and operation by a Skills Lab require a large outlay of resources. Therefore, the Practical Skills Committee of the Medical Education Society (GMA) introduced a new project, which aims to improve the flow of information between the Skills Labs and enable a transparent assessment of the simulators via an online database (the Simulator Network).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

In the present study the challenge of analyzing complex micro X-ray diffraction (microXRD) patterns from cement–clay interfaces has been addressed. In order to extract the maximum information concerning both the spatial distribution and the crystal structure type associated with each of the many diffracting grains in heterogeneous, polycrystalline samples, an approach has been developed in which microXRD was applied to thin sections which were rotated in the X-ray beam. The data analysis, performed on microXRD patterns collected from a filled vein of a cement–clay interface from the natural analogue in Maqarin (Jordan), and a sample from a two-year-old altered interface between cement and argillaceous rock, demonstrate the potential of this method.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Group B Streptococcus (GBS) causes invasive infections in neonates, older adults and patients with comorbidities. β-hemolysin/cytolysin is an important GBS virulence factor. It is encoded by the cyl operon and confers GBS hemolytic activity. Isolates displaying hyperpigmentation are typically hyperhemolytic. Comparison of clonally identical isolates displaying different levels of pigmentation has shown transcriptional dysregulation due to mutations in components of the control of the virulence S/R (CovS/R) regulatory system. In addition, hyperpigmented isolates show decreased CAMP factor and decreased capsule thickness. In analogy to findings in group A Streptococcus, a pivotal role of CovS/R has been proposed in the host-pathogen interaction of invasive GBS infection. However, corresponding investigations on multiple clinical GBS isolates have not been performed. We prospectively collected hyperpigmented isolates found in a diagnostic laboratory and performed phenotypic, molecular and transcriptional analyses. In the period from 2008 to 2012, we found 10 isolates obtained from 10 patients. The isolates reflected both invasive pathogens and colonizers. In three cases, clonally identical but phenotypically different variants were also found. Hence, the analyses included 13 isolates. No capsular serotype was found to be significantly more frequent. Bacterial pigments were analyzed via spectrophotometry and for their hemolytic activity. Data obtained for typical absorbance spectra peaks correlated significantly with hemolytic activity. Molecular analysis of the cyl operon showed that it was conserved in all isolates. The covR sequence displayed mutations in five isolates; in one isolate, the CovR binding site to cylX was abrogated. Our results on clinical isolates support previous findings on CovR-deficient isogenic mutants, but suggest that - at least in some clinical isolates - for β-hemolysin/cytolysin and CAMP factor production, other molecular pathways may be involved.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

BACKGROUND AND PURPOSE We report on workflow and process-based performance measures and their effect on clinical outcome in Solitaire FR Thrombectomy for Acute Revascularization (STAR), a multicenter, prospective, single-arm study of Solitaire FR thrombectomy in large vessel anterior circulation stroke patients. METHODS Two hundred two patients were enrolled across 14 centers in Europe, Canada, and Australia. The following time intervals were measured: stroke onset to hospital arrival, hospital arrival to baseline imaging, baseline imaging to groin puncture, groin puncture to first stent deployment, and first stent deployment to reperfusion. Effects of time of day, general anesthesia use, and multimodal imaging on workflow were evaluated. Patient characteristics and workflow processes associated with prolonged interval times and good clinical outcome (90-day modified Rankin score, 0-2) were analyzed. RESULTS Median times were onset of stroke to hospital arrival, 123 minutes (interquartile range, 163 minutes); hospital arrival to thrombolysis in cerebral infarction (TICI) 2b/3 or final digital subtraction angiography, 133 minutes (interquartile range, 99 minutes); and baseline imaging to groin puncture, 86 minutes (interquartile range, 24 minutes). Time from baseline imaging to puncture was prolonged in patients receiving intravenous tissue-type plasminogen activator (32-minute mean delay) and when magnetic resonance-based imaging at baseline was used (18-minute mean delay). Extracranial carotid disease delayed puncture to first stent deployment time on average by 25 minutes. For each 1-hour increase in stroke onset to final digital subtraction angiography (or TICI 2b/3) time, odds of good clinical outcome decreased by 38%. CONCLUSIONS Interval times in the STAR study reflect current intra-arterial therapy for patients with acute ischemic stroke. Improving workflow metrics can further improve clinical outcome. CLINICAL TRIAL REGISTRATION: URL http://www.clinicaltrials.gov. Unique identifier: NCT01327989.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

From a biological point of view, casting refers to filling of anatomical and/or pathological spaces with extraneous material that reproduces a three-dimensional replica of the space. Casting may be accompanied by additional procedures such as corrosion, in which the soft tissue is digested out, leaving a clean cast, or the material may be mixed with radiopaque substances to allow x-ray photography or micro computed topography (µCT) scanning. Alternatively, clearing of the surrounding soft tissue increases transparency and allows visualization of the casted cavities. Combination of casting with tissue fixation allows anatomical dissection and didactic surgical procedures on the tissue. Casting materials fall into three categories namely, aqueous substances (India ink, Prussian blue ink), pliable materials (gelatins, latex, and silicone rubber), or hard materials (methyl methacrylates, polyurethanes, polyesters, and epoxy resins). Casting has proved invaluable in both teaching and research and many phenomenal biological processes have been discovered through casting. The choice of a particular material depends inter alia on the targeted use and the intended subsequent investigative procedures, such as dissection, microscopy, or µCT. The casting material needs to be pliable where anatomical and surgical manipulations are intended, and capillary-passable for ultrastructural investigations.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Modified nucleoside triphosphates (dA(Hs)TP, dU(POH)TP, and dC(Val)TP) bearing imidazole, hydroxyl, and carboxylic acid residues connected to the purine and pyrimidine bases through alkyne linkers were prepared. These modified dN*TPs were excellent substrates for various DNA polymerases in primer extension reactions. Moreover, the combined use of terminal deoxynucleotidyl transferase (TdT) and the modified dNTPs led to efficient tailing reactions that rival those of natural counterparts. Finally, the triphosphates were tolerated by polymerases under PCR conditions, and the ensuing modified oligonucleotides served as templates for the regeneration of unmodified DNA. Thus, these modified dN*TPs are fully compatible with in vitro selection methods and can be used to develop artificial peptidases based on DNA.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Tricyclo-DNA (tc-DNA) is a conformationally restricted oligonucleotide analogue that exhibits promising properties as a robust antisense agent. Here we report on the synthesis and biochemical characterization of tc-TTP, the triphosphate of a tc-DNA nucleoside containing the base thymine. Tc-TTP turned out to be a substrate for the Vent (exo−) DNA polymerase, a polymerase that allows for multiple incorporations of tc-T nucleotides under primer extension reaction conditions. However, the substrate acceptance is rather low, as also observed for other sugar-modified analogues. Tc-TTP and tc-nucleotide-containing templates do not sustain enzymatic polymerization under physiological conditions; this indicates that tc-DNA-based antisense agents will not enter natural metabolic pathways that lead to long-term toxicity.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

A method for the culturing and propagation of ovine bone marrow-derived macrophages (BMM) in vitro is described. Bone marrow cells from sterna of freshly slaughtered sheep were cultured in hydrophobic (teflon foil) bags in the presence of high serum concentrations (20% autologous serum and 20% fetal calf serum). During an 18 day culture period in the absence of added conditioned medium, and without medium change, a strong enrichment of mononuclear phagocytes was achieved. Whereas the number of macrophages increased four to fivefold during this time, granulocytes, lymphoid cells, stem cells and undifferentiated progenitor cells were reduced to less than 3% of their numbers at Day 0. This resulted in BMM populations of 94 +/- 3% purity. These cells had morphological and histochemical characteristics of differentiated macrophages, and they performed functions similar to those of non-activated, unprimed human monocyte-derived macrophages. Thus, they avidly ingested erythrocytes coated with IgG of heterologous or homologous origin. They expressed a modest level of procoagulant activity, but upon triggering with lipopolysaccharide (LPS), a marked increase in cell-associated procoagulant activity was observed. LPS triggering promoted the secretion of interleukin-1, as evidenced by measurement of murine thymocyte costimulatory activity, and transforming growth factor-beta. Using the mouse L929 cell cytotoxicity assay as an indication of tumor necrosis factor (TNF) activity, no TNF activity was detected in the same supernatants, a result possibly due to species restriction. BMM generated low levels of O2- upon triggering with phorbol 12-myristate 13-acetate (PMA). On the other hand, no O2- production was observed upon stimulation with zymosan opsonized with ovine or human serum. Using luminol-enhanced chemiluminescence (CL) as a more sensitive indicator of an oxidative burst, both PMA or zymosan were able to trigger CL, but the response was subject to partial inhibition by sodium azide, an inhibitor of myeloperoxidase. This points to non-macrophage cells contributing also to the CL response, and is consistent with the view that unprimed BMM elicit a low oxidative burst upon triggering with strong inducers of a burst. Our functional characterization now allows us to apply priming and activation protocols and to relate their effect to functional alterations.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Background: Despite its extensive use as a nitrogen fertilizer, the role of urea as a directly accessible nitrogen source for crop plants is still poorly understood. So far, the physiological and molecular aspects of urea acquisition have been investigated only in few plant species highlighting the importance of a high-affinity transport system. With respect to maize, a worldwide-cultivated crop requiring high amounts of nitrogen fertilizer, the mechanisms involved in the transport of urea have not yet been identified. The aim of the present work was to characterize the high-affinity urea transport system in maize roots and to identify the high affinity urea transporter. Results: Kinetic characterization of urea uptake (<300 mu M) demonstrated the presence in maize roots of a high-affinity and saturable transport system; this system is inducible by urea itself showing higher Vmax and Km upon induction. At molecular level, the ORF sequence coding for the urea transporter, ZmDUR3, was isolated and functionally characterized using different heterologous systems: a dur3 yeast mutant strain, tobacco protoplasts and a dur3 Arabidopsis mutant. The expression of the isolated sequence, ZmDUR3-ORF, in dur3 yeast mutant demonstrated the ability of the encoded protein to mediate urea uptake into cells. The subcellular targeting of DUR3/GFP fusion proteins in tobacco protoplasts gave results comparable to the localization of the orthologous transporters of Arabidopsis and rice, suggesting a partial localization at the plasma membrane. Moreover, the overexpression of ZmDUR3 in the atdur3-3 Arabidopsis mutant showed to complement the phenotype, since different ZmDUR3-overexpressing lines showed either comparable or enhanced 15N]-urea influx than wild-type plants. These data provide a clear evidence in planta for a role of ZmDUR3 in urea acquisition from an extra-radical solution. Conclusions: This work highlights the capability of maize plants to take up urea via an inducible and high-affinity transport system. ZmDUR3 is a high-affinity urea transporter mediating the uptake of this molecule into roots. Data may provide a key to better understand the mechanisms involved in urea acquisition and contribute to deepen the knowledge on the overall nitrogen-use efficiency in crop plants.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Coumarins are extensively studied anticoagulants that exert additional effects such as anticancerogenic and even anti-inflammatory. In order to find new drugs with anticancer activities, we report here the synthesis and the structural analysis of new coumarin derivatives which combine the coumarin core and five member heterocycles in hydrazinylidene-chroman-2,4-diones. The derivatives were prepared by derivatization of the appropriate heterocyclic amines which were used as electrophiles to attack the coumarin ring. The structures were characterized by spectroscopic techniques including IR, NMR, 2D-NMR and MS. These derivatives were further characterized especially in terms of a potential cytotoxic and apoptogenic effect in several cancer cell lines including the breast and prostate cancer cell lines MCF-7, MDA-MB-231, PC-3, LNCaP, and the monocytic leukemia cell line U937. Cell viability was determined after 48 h and 72 h of treatment with the novel compounds by MTT assay and the 50% inhibitory concentrations (EC50 values) were determined. Out of the 8 novel compounds screened for reduced cell viability, 4c, 4d and 4e were found to be the most promising and effective ones having EC50 values that were several fold reduced when compared to the reference substance 4-hydroxycoumarin. However, the effects were cancer cell line dependent. The breast cancer MDA-MB-231 cells, the prostate cancer LNCaP cells, and U937 cells were most sensitive, MCF-7 cells were less sensitive, and PC-3 cells were more resistant. Reduced cell viability was accompanied by increased apoptosis as shown by PARP-1 cleavage and reduced activity of the survival protein kinase Akt. In summary, this study has identified three novel coumarin derivatives that in comparison to 4-hydroxycoumarin have a higher efficiency to reduce cancer cell viability and trigger apoptosis and therefore may represent interesting novel drug candidates

Relevância:

100.00% 100.00%

Publicador:

Resumo:

The spread of antibiotic-resistant bacteria through food has become a major public health concern because some important human pathogens may be transferred via the food chain. Acinetobacter baumannii is one of the most life-threatening gram-negative pathogens; multidrug-resistant (MDR) clones of A. baumannii are spreading worldwide, causing outbreaks in hospitals. However, the role of raw meat as a reservoir of A. baumannii remains unexplored. In this study, we describe for the first time the antibiotic susceptibility and fingerprint (repetitive extragenic palindromic PCR [rep-PCR] profile and sequence types [STs]) of A. baumannii strains found in raw meat retailed in Switzerland. Our results indicate that A. baumannii was present in 62 (25.0%) of 248 (CI 95%: 19.7 to 30.9%) meat samples analyzed between November 2012 and May 2013, with those derived from poultry being the most contaminated (48.0% [CI 95%: 37.8 to 58.3%]). Thirty-nine strains were further tested for antibiotic susceptibility and clonality. Strains were frequently not susceptible (intermediate and/or resistant) to third- and fourth-generation cephalosporins for human use (i.e., ceftriaxone [65%], cefotaxime [32%], ceftazidime [5%], and cefepime [2.5%]). Resistance to piperacillin-tazobactam, ciprofloxacin, colistin, and tetracycline was sporadically observed (2.5, 2.5, 5, and 5%, respectively), whereas resistance to carbapenems was not found. The strains were genetically very diverse from each other and belonged to 29 different STs, forming 12 singletons and 6 clonal complexes (CCs), of which 3 were new (CC277, CC360, and CC347). RepPCR analysis further distinguished some strains of the same ST. Moreover, some A. baumannii strains from meat belonged to the clonal complexes CC32 and CC79, similar to the MDR isolates responsible for human infections. In conclusion, our findings suggest that raw meat represents a reservoir of MDR A. baumannii and may serve as a vector for the spread of these pathogens into both community and hospital settings.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Policy actors tend to misinterpret and distrust opponents in policy processes. This phenomenon, known as the “devil shift”, consists of the following two dimensions: actors perceive opponents as more powerful and as more evil than they really are. Analysing nine policy processes in Switzerland, this article highlights the drivers of the devil shift at two levels. On the actor level, interest groups, political parties and powerful actors suffer more from the devil shift than state actors and powerless actors. On the process level, the devil shift is stronger in policy processes dealing with socio-economic issues as compared with other issues. Finally, and in line with previous studies, there is less empirical evidence of the power dimension of the devil shift phenomenon than of its evilness dimension.