925 resultados para Combined
Resumo:
[EN] Confluence of anthropogenic influences is common in coastal areas (e.g., disposal of different pollutants like industrial and domestic sewage, brine, etc.). In this study we assessed whether the combined disposal of domestic sewage and brine altered patterns in the abundance and assemblage structure of subtidal meiofauna inhabiting sandy seabeds. Samples were collected in May 2008 and January 2009 at varying distances (0, 15, and 30 m) from the discharge point. Meiofaunal abundances were consistently larger at 0 m (1663.05 ± 1076.86 ind 10 cm?2, mean ± standard error) than at 15 m (471.21 ± 307.97 ind 10 cm?2) and 30 m (316.50 ± 256.85 ind 10 cm?2) from the discharge outfall. This pattern was particularly accentuated for nematodes. Proximity to the discharge point also altered patterns in meiofaunal assemblage structure, though temporal shifts in the sedimentary composition also contributed to explain differences in the meiofaunal assemblage structure. As a result, meiofauna may be a reliable tool for monitoring studies of the combined disposal of sewage and brine as long as potential confounding factors (here temporal changes in grain size composition) are considered.
Resumo:
The majority of carbonate reservoir is oil-wet, which is an unfavorable condition for oil production. Generally, the total oil recovery after both primary and secondary recovery in an oil-wet reservoir is low. The amount of producible oil by enhanced oil recovery techniques is still large. Alkali substances are proven to be able to reverse rock wettability from oil-wet to water-wet, which is a favorable condition for oil production. However, the wettability reversal mechanism would require a noneconomical aging period to reach the maximum reversal condition. An intermittent flow with the optimum pausing period is then combined with alkali flooding (combination technique) to increase the wettability reversal mechanism and as a consequence, oil recovery is improved. The aims of this study are to evaluate the efficiency of the combination technique and to study the parameters that affect this method. In order to implement alkali flooding, reservoir rock and fluid properties were gathered, e.g. interfacial tension of fluids, rock wettability, etc. The flooding efficiency curves are obtained from core flooding and used as a major criterion for evaluation the performance of technique. The combination technique improves oil recovery when the alkali concentration is lower than 1% wt. (where the wettability reversal mechanism is dominant). The soap plug (that appears when high alkali concentration is used) is absent in this combination as seen from no drop of production rate. Moreover, the use of low alkali concentration limits alkali loss. This combination probably improves oil recovery also in the fractured carbonate reservoirs in which oil is uneconomically produced. The results from the current study indicate that the combination technique is an option that can improve the production of carbonate reservoirs. And a less quantity of alkali is consumed in the process.
Resumo:
Objective: To investigate the prognostic significance of ST-segment elevation (STE) in aVR associated with ST-segment depression (STD) in other leads in patients with non-STE acute coronary syndrome (NSTE-ACS). Background: In NSTE-ACS patients, STD has been extensively associated with severe coronary lesions and poor outcomes. The prognostic role of STE in aVR is uncertain. Methods: We enrolled 888 consecutive patients with NSTE-ACS. They were divided into two groups according to the presence or not on admission ECG of aVR STE≥ 1mm and STD (defined as high risk ECG pattern). The primary and secondary endpoints were: in-hospital cardiovascular (CV) death and the rate of culprit left main disease (LMD). Results: Patients with high risk ECG pattern (n=121) disclosed a worse clinical profile compared to patients (n=575) without [median GRACE (Global-Registry-of-Acute-Coronary-Events) risk score =142 vs. 182, respectively]. A total of 75% of patients underwent coronary angiography. The rate of in-hospital CV death was 3.9%. On multivariable analysis patients who had the high risk ECG pattern showed an increased risk of CV death (OR=2.88, 95%CI 1.05-7.88) and culprit LMD (OR=4.67,95%CI 1.86-11.74) compared to patients who had not. The prognostic significance of the high risk ECG pattern was maintained even after adjustment for the GRACE risk score (OR = 2.28, 95%CI:1.06-4.93 and OR = 4.13, 95%CI:2.13-8.01, for primary and secondary endpoint, respectively). Conclusions: STE in aVR associated with STD in other leads predicts in-hospital CV death and culprit LMD. This pattern may add prognostic information in patients with NSTE-ACS on top of recommended scoring system.
Resumo:
The work of the present thesis is focused on the implementation of microelectronic voltage sensing devices, with the purpose of transmitting and extracting analog information between devices of different nature at short distances or upon contact. Initally, chip-to-chip communication has been studied, and circuitry for 3D capacitive coupling has been implemented. Such circuits allow the communication between dies fabricated in different technologies. Due to their novelty, they are not standardized and currently not supported by standard CAD tools. In order to overcome such burden, a novel approach for the characterization of such communicating links has been proposed. This results in shorter design times and increased accuracy. Communication between an integrated circuit (IC) and a probe card has been extensively studied as well. Today wafer probing is a costly test procedure with many drawbacks, which could be overcome by a different communication approach such as capacitive coupling. For this reason wireless wafer probing has been investigated as an alternative approach to standard on-contact wafer probing. Interfaces between integrated circuits and biological systems have also been investigated. Active electrodes for simultaneous electroencephalography (EEG) and electrical impedance tomography (EIT) have been implemented for the first time in a 0.35 um process. Number of wires has been minimized by sharing the analog outputs and supply on a single wire, thus implementing electrodes that require only 4 wires for their operation. Minimization of wires reduces the cable weight and thus limits the patient's discomfort. The physical channel for communication between an IC and a biological medium is represented by the electrode itself. As this is a very crucial point for biopotential acquisitions, large efforts have been carried in order to investigate the different electrode technologies and geometries and an electromagnetic model is presented in order to characterize the properties of the electrode to skin interface.
Resumo:
Our research asked the following main questions: how the characteristics of professionals service firms allow them to successfully innovate in exploiting through exploring by combining internal and external factors of innovation and how these ambidextrous organisations perceive these factors; and how do successful innovators in professional service firms use corporate entrepreneurship models in their new service development processes? With a goal to shed light on innovation in professional knowledge intensive business service firms’ (PKIBS), we concluded a qualitative analysis of ten globally acting law firms, providing business legal services. We analyse the internal and factors of innovation that are critical for PKIBS’ innovation. We suggest how these firms become ambidextrous in changing environment. Our findings show that this kind of firms has particular type of ambidexterity due to their specific characteristics. As PKIBS are very dependant on its human capital, governance structure, and the high expectations of their clients, their ambidexterity is structural, but also contextual at the same time. In addition, we suggest 3 types of corporate entrepreneurship models that international PKIBS use to enhance innovation in turbulent environments. We looked at how law firms going through turbulent environments were using corporate entrepreneurship activities as a part of their strategies to be more innovative. Using visual mapping methodology, we developed three types of innovation patterns in the law firms. We suggest that corporate entrepreneurship models depend on successful application of mainly three elements: who participates in corporate entrepreneurship initiatives; what are the formal processes that enhances these initiatives; and what are the policies applied to this type of behaviour.
Resumo:
Introduction: Open fractures of the leg represent a severe trauma. The combined approach, shared between plastic and orthopaedic surgeons, is considered to be important, although this multidisciplinary treatment is not routinely performed. Aim of this study was to verify whether the orthoplastic treatment is of any advantage over the traditional simply orthopedic treatment, through a multicentric inclusion of these unfrequent injuries into a prospective study. Material and methods: The following trauma centres were involved: Rizzoli Orthopaedic Institute/University of Bologna (leading centre) and Maggiore Hospital (Bologna, Italy), Frenchay Hospital (Bristol, United Kingdom), Jinnah Hospital (Lahore, Pakistan). All patients consecutively hospitalized in the mentioned centres between January 2012 and December 2013 due to tibial open fractures were included in the study and prospectively followed up to December 2014. Demographics and other clinical features were recorded, including the type of treatment (orthopaedic or orthoplastic). The considered outcome measures included duration of hospitalization, time for bone union and soft tissue closure, Enneking score at 3, 6 and 12 months, the incidence of osteomyelitis and other complications. Results: A total of 164 patients were included in the study. Out of them 68% were treated with an orthoplastic approach, whereas 32% received a purely orthopedic treatment. All considered outcome measures showed to be improved by the orthoplastic approach, compared to the orthopaedic one: time for soft tissue closure (2 versus 25 weeks), duration of hospital stay (22 versus 55 days), time for bone union (6 versus 8.5 months) , number of additional operations (0.6 versus 1.2) and functional recovery of the limb at 12 months (27 versus 19, Enneking’s score). All results were statistically significant. Conclusion: The combined orthoplastic approach to the treatment of open tibia fractures, in particular for high grade injuries (Gustilo 3B), is proven to improve the outcome of these severe injuries.
Resumo:
In this thesis is described the design and synthesis of potential agents for the treatment of the multifactorial Alzheimer’s disease (AD). Our multi-target approach was to consider cannabinoid system involved in AD, together with classic targets. In the first project, designed modifications were performed on lead molecule in order to increase potency and obtain balanced activities on fatty acid amide hydrolase and cholinesterases. A small library of compounds was synthesized and biological results showed increased inhibitory activity (nanomolar range) related to selected target. The second project was focused on the benzofuran framework, a privileged structure being a common moiety found in many biologically active natural products and therapeutics. Hybrid molecules were designed and synthesized, focusing on the inhibition of cholinesterases, Aβ aggregation, FAAH and on the interaction with CB receptors. Preliminary results showed that several compounds are potent CB ligands, in particular the high affinity for CB2 receptors, could open new opportunities to modulate neuroinflammation. The third and the fourth project were carried out at the IMS, Aberdeen, under the supervision of Prof. Matteo Zanda. The role of the cannabinoid system in the brain is still largely unexplored and the relationship between the CB1 receptors functional modification, density and distribution and the onset of a pathological state is not well understood. For this reasons, Rimonabant analogues suitable as radioligands were synthesized. The latter, through PET, could provide reliable measurements of density and distribution of CB1 receptors in the brain. In the fifth project, in collaboration with CHyM of York, the goal was to develop arginine analogues that are target specific due to their exclusively location into NOS enzymes and could work as MRI contrasting agents. Synthesized analogues could be suitable substrate for the transfer of polarization by p-H2 molecules through SABRE technique transforming MRI a more sensitive and faster technique.
Resumo:
Diese Arbeit beschreibt die Entwicklung, Konstruktion und Untersuchung eines Magnetometers zur exakten und präzisen Messung schwacher Magnetfelder. Diese Art von Magnetometer eignet sich zur Anwendung in physikalischen hochpräzisions Experimenten wie zum Beispiel der Suche nach dem elektrischen Dipolmomentrndes Neutrons. Die Messmethode beruht auf der gleichzeitigen Detektion der freien Spin Präzession Kern-Spin polarisierten 3He Gases durch mehrere optisch gepumpte Cäsium Magnetometer. Es wird gezeigt, dass Cäsium Magnetometer eine zuverlässige und vielseitige Methode zur Messung der 3He Larmor Frequenz und eine komfortable Alternative zur Benutzung von SQUIDs für diesen Zweck darstellen. Ein Prototyp dieses Magnetometers wurde gebaut und seine Funktion in der magnetisch abgeschirmten Messkabine der Physikalisch Technischen Bundesanstalt untersucht. Die Sensitivität des Magnetometers in Abhängigkeitrnvon der Messdauer wurde experimentell untersucht. Es wird gezeigt, dass für kurze Messperioden (< 500s) Cramér-Rao limitierte Messungen möglich sind während die Sensitivität bei längeren Messungen durch die Stabilität des angelegten Magnetfeldes limitiert ist. Messungen eines 1 muT Magnetfeldes mit einer relative Genauigkeit von besser als 5x10^(-8) in 100s werden präsentiert. Es wird gezeigt, dass die Messgenauigkeit des Magnetometers durch die Zahl der zur Detektion der 3He Spin Präzession eingesetzten Cäsium Magnetometer skaliert werden kann. Prinzipiell ist dadurch eine Anpassung der Messgenauigkeit an jegliche experimentellen Bedürfnisse möglich. Es wird eine gradiometrische Messmethode vorgestellt, die es erlaubt den Einfluss periodischerrnmagnetischer Störungen auf dieMessung zu unterdrücken. Der Zusammenhang zwischen der Sensitivität des kombinierten Magnetometers und den Betriebsparametern der Cäsium Magnetometer die zur Spin Detektion verwendet werden wird theoretisch untersucht und anwendungsspezifische Vor- und Nachteile verschiedener Betriebsartenwerden diskutiert. Diese Zusammenhänge werden in einer Formel zusammengefasst die es erlaubt, die erwartete Sensitivität des Magnetometers zu berechnen. Diese Vorhersagen befinden sich in perfekter Übereinstimmung mit den experimentellen Daten. Die intrinsische Sensitivität des Magnetometer Prototyps wird auf Basis dieser Formel theoretisch bestimmt. Ausserdem wird die erwartete Sensitivität für die Anwendung im Rahmen des Experiments der nächsten Generation zur Bestimmung des elektrischenrnDipolmoments des Neutrons am Paul Scherrer Institut abgeschätzt. Des weiteren wird eine bequeme experimentelle Methode zur Messung des Polarisationsgrades und des Rabi Flip-Winkels der 3He Kernspin Polarisation vorgestellt. Letztere Messung ist sehr wichtig für die Anwendung in hochpräzisions Experimenten.
Resumo:
In the last years, the European countries have paid increasing attention to renewable sources and greenhouse emissions. The Council of the European Union and the European Parliament have established ambitious targets for the next years. In this scenario, biomass plays a prominent role since its life cycle produces a zero net carbon dioxide emission. Additionally, biomass can ensure plant operation continuity thanks to its availability and storage ability. Several conventional systems running on biomass are available at the moment. Most of them are performant either in the large-scale or in the small power range. The absence of an efficient system on the small-middle scale inspired this thesis project. The object is an innovative plant based on a wet indirectly fired gas turbine (WIFGT) integrated with an organic Rankine cycle (ORC) unit for combined heat and power production. The WIFGT is a performant system in the small-middle power range; the ORC cycle is capable of giving value to low-temperature heat sources. Their integration is investigated in this thesis with the aim of carrying out a preliminary design of the components. The targeted plant output is around 200 kW in order not to need a wide cultivation area and to avoid biomass shipping. Existing in-house simulation tools are used: They are adapted to this purpose. Firstly the WIFGT + ORC model is built; Zero-dimensional models of heat exchangers, compressor, turbines, furnace, dryer and pump are used. Different fluids are selected but toluene and benzene turn out to be the most suitable. In the indirectly fired gas turbine a pressure ratio around 4 leads to the highest efficiency. From the thermodynamic analysis the system shows an electric efficiency of 38%, outdoing other conventional plants in the same power range. The combined plant is designed to recover thermal energy: Water is used as coolant in the condenser. It is heated from 60°C up to 90°C, ensuring the possibility of space heating. Mono-dimensional models are used to design the heat exchange equipment. Different types of heat exchangers are chosen depending on the working temperature. A finned-plate heat exchanger is selected for the WIFGT heat transfer equipment due to the high temperature, oxidizing and corrosive environment. A once-through boiler with finned tubes is chosen to vaporize the organic fluid in the ORC. A plate heat exchanger is chosen for the condenser and recuperator. A quasi-monodimensional model for single-stage axial turbine is implemented to design both the WIFGT and the ORC turbine. The system simulation after the components design shows an electric efficiency around 34% with a decrease by 10% compared to the zero-dimensional analysis. The work exhibits the system potentiality compared to the existing plants from both technical and economic point of view.
Resumo:
Combined modality treatment (CMT) of chemotherapy followed by localized radiotherapy is standard treatment for patients with early stage Hodgkin's lymphoma. However, the role of radiotherapy has been questioned recently and some clinical study groups advocate chemotherapy only for this indication. We thus performed a systematic review with meta-analysis of randomized controlled trials comparing chemotherapy alone with CMT in patients with early stage Hodgkin's lymphoma with respect to response rate, tumor control and overall survival (OS). We searched Medline, EMBASE and the Cochrane Library as well as conference proceedings from January 1980 to February 2009 for randomized controlled trials comparing chemotherapy alone versus the same chemotherapy regimen plus radiotherapy. Progression free survival and similar outcomes were analyzed together as tumor control. Effect measures used were hazard ratios for OS and tumor control as well as relative risks for complete response (CR). Meta-analyses were performed using RevMan5. Five randomized controlled trials involving 1,245 patients were included. The hazard ratio (HR) was 0.41 (95% confidence interval (CI) 0.25 to 0.66) for tumor control and 0.40 (95% CI 0.27 to 0.59) for OS for patients receiving CMT compared to chemotherapy alone. CR rates were similar between treatment groups. In sensitivity analyses another 6 trials were included that did not fulfill the inclusion criteria of our protocol but were considered relevant to the topic. These trials underlined the results of the main analysis. In conclusion, adding radiotherapy to chemotherapy improves tumor control and OS in patients with early stage Hodgkin's lymphoma.
Resumo:
We sought to compare reflux and symptom association patterns in patients with nonerosive reflux disease (NERD), erosive esophagitis (EE), and in healthy volunteers (HVs).
Resumo:
We review the functional and oncologic outcomes of seminal vesicle and prostate capsule sparing cystectomy combined with ileal orthotopic bladder substitution.
Resumo:
PURPOSE The aim of this study was to evaluate the antibiotic treatment of postoperative endophthalmitis with combined systemic meropenem and linezolid. METHODS A retrospective analysis of endophthalmitis treated with systemic meropenem and linezolid compared to conventional systemic antibiotics by evaluation of outcome and adverse effects was carried out. RESULTS 26 patients with unilateral postoperative endophthalmitis with a systemic combination regimen of meropenem (2 g TID, mean duration of treatment 5.5 days) and linezolid (600 mg BID, mean duration of treatment 8.9 days) (group 1, mean follow-up time 140 days) were included in this study and compared to 45 postoperative endophthalmitis patients treated with conventional systemic antibiotics (group 2; mean follow-up time 320 days). In group 1, 69.2 % of eyes additionally received intravitreal amikacin and vancomycin (vs. 24.4 % in group 2; p < 0.001), in 92.3 % pars plana vitrectomy was performed (vs. 68.9 % in group 2, p = 0.047). Mean best corrected visual acuity improved from a baseline of 1.76 logMar for group 1 and 1.83 logMar for group 2 to 0.91 logMar (p = 0.0001) and 0.90 logMar (p < 0.0001), respectively, at the end of the follow-up, revealing no significant differences between the two groups at any time point (p > 0.05). Ocular complications were observed in 34.6 % of eyes in group 1 (vs. 37.8 % in group 2; p > 0.05). Adverse drug effects occurred significantly more frequently in group 1 (26.9 % vs. 4.4 % p = 0.02). CONCLUSION In spite of the reported better penetration through the blood-ocular barrier and the broader antibacterial spectrum of meropenem and linezolid, no benefit in outcome was found in the present study. In contrast, adverse effects and costs of the combination regimen were significantly higher.