Advanced Formation Fluid Evaluation While Drilling with a New Heavy Gas Detector

In this paper, a chromatograph which exploits the benefits of FID technology optimized for the high resolution detection of heavier hydrocarbon gas components is described. The components analyzed span from n-hexane to toluene. Flame Ionization Detector (FID) technology is not new to gas detection on the field, however it had never been applied to the detection of gases heavier than n-pentane. The instrumentation has been installed and run on a number of wells in different fields and countries, and it has operated as a complement of an advanced surface logging system for a period of two years. Unlike other technologies presently utilized for this scope, this system reduces dedicated equipment and personnel to a minimum. The results presented show the clear identification of formation fluid contacts with higher accuracy than standard light gas detectors, the recognition of contaminants within the drilling fluid, and the practicality of operating an advanced gas detection system with minimal operational and logistic footprint. Some of the indications obtained challenge common beliefs about gas detection: consistent extraction of heavy hydrocarbon gases from the drilling fluid is possible at relatively low temperatures, provided that the entire gas extraction system is rigorously controlled in terms of gas sample pressure, flow, and temperature. Furthermore, gas data analysis can yield indications on the fluid composition even when the gases analyzed are in extremely low quantity. The system utilizes known technologies, developed and optimized to obtain new results. The system supports formation evaluation when LWD or wireline can be inconclusive, in the presence of a low porosity pay or fresh water. It can also guide and optimize the MDT testing program. Furthermore, the system takes into account the constraints of drilling operations, and strikes a balance between data accuracy and practicality of the application

Investigating The Physics Case of Running a B-Factory at the Y(5S) Resonance

We discuss the physics case of a high luminosity B-Factory running at the Y(5S) resonance. We show that the coherence of the B meson pairs is preserved at this resonance, and that Bs can be well distinguished from Bd and charged B mesons. These facts allow to cover the physics program of a traditional B-Factory and, at the same time, to perform complementary measurements which are not accessible at the Y(4S). In particular we show how, despite the experimental limitations in performing time-dependent measurements of Bs decays, the same experimental information can be extracted, in several cases, from the determination of time-integrated observables. In addition, a few examples of the potentiality in measuring rare Bs decays are given. Finally, we discuss how the study of Bs meson will improve the constraints on New Physics parameters in the Bs sector, in the context of the generalized Unitarity Triangle analysis.Comment: 47 pages, 22 figure

Low-density lipoprotein-lowering medication and platelet function

Elevated low-density lipoprotein (LDL) cholesterol (LDL-C) levels represent one of the most important risk factors for atherosclerosis and therefore cardiovascular morbidity and mortality. LDL-C operates at different levels and through various classic and non-classic mechanisms. In particular, increased or modified LDL enhances platelet function and increases sensitivity of platelets to several naturally occurring agonists. Agents that lower LDL-C in hypercholesterolemic patients have been shown to interfere with platelet function. Several studies, in fact, suggested that statins exert anti-thrombotic effects largely as a result of an anti-platelet activity. Among the other LDL-C-lowering agents those acting by interfering with cholesterol reabsorption from the gut (cholestyramine, colestipol) do not appear to interfere with platelet function, whereas peroxisome proliferator-activated receptor agonists (such as fibrates) can inhibit platelet function. The full potential of these drugs in vascular protection is only just being realized. Further studies are still needed to elucidate the full therapeutic benefits of these agents in plaque stabilization and thrombosis. Copyright (c) 2006 S. Karger AG, Basel

Platelet activation in type 2 diabetes mellitus

The abnormal metabolic state that accompanies diabetes renders arteries susceptible to atherosclerosis, being capable of altering the functional properties of multiple cell types, including endothelium and platelets. In particular, an altered platelet metabolism and changes in intraplatelet signaling pathways may contribute to the pathogenesis of atherothrombotic complications of diabetes. A variety of mechanisms may be responsible for enhanced platelet aggregation. Among them, hyperglycemia may represent a causal factor for in vivo platelet activation, and may be responsible for nonenzymatic glycation of platelet glycoproteins, causing changes in their structure and conformation, as well as alterations of membrane lipid dynamics. Furthermore, hyperglycemia-induced oxidative stress is responsible for enhanced peroxidation of arachidonic acid to form biologically active isoprostanes, which represents an important biochemical link between impaired glycemic control and persistent platelet activation. Finally, increased oxidative stress is responsible for activation of transcription factors and expression of redox-sensitive genes leading to a phenotypic switch of endothelium toward an adhesive, prothrombotic condition, initial platelet activation, adhesion and subsequent platelet aggregate formation. All this evidence is strengthened by the results of clinical trials documenting the beneficial effects of metabolic control on platelet function, and by the finding that aspirin treatment may even be more beneficial in diabetic than in high-risk non-diabetic patients. Attention to appropriate medical management of diabetic patients will have great impact on long-term outcome in this high-risk population. © 2004 International Society on Thrombosis and Haemostasis

Graphene-based nanomaterials for tissue engineering in the dental field

The world of dentistry is approaching graphene-based nanomaterials as substitutes for tissue engineering. Apart from its exceptional mechanical strength, electrical conductivity and thermal stability, graphene and its derivatives can be functionalized with several bioactive molecules. They can also be incorporated into different scaffolds used in regenerative dentistry, generating nanocomposites with improved characteristics. This review presents the state of the art of graphene-based nanomaterial applications in the dental field. We first discuss the interactions between cells and graphene, summarizing the available in vitro and in vivo studies concerning graphene biocompatibility and cytotoxicity. We then highlight the role of graphene-based nanomaterials in stem cell control, in terms of adhesion, proliferation and differentiation. Particular attention will be given to stem cells of dental origin, such as those isolated from dental pulp, periodontal ligament or dental follicle. The review then discusses the interactions between graphene-based nanomaterials with cells of the immune system; we also focus on the antibacterial activity of graphene nanomaterials. In the last section, we offer our perspectives on the various opportunities facing the use of graphene and its derivatives in associations with titanium dental implants, membranes for bone regeneration, resins, cements and adhesives as well as for tooth-whitening procedure

Activité antimicrobienne de produits naturels originaires du Nord de l’Ontario

La multirésistance microbienne pose de grands problèmes au niveau de la santé publique. En fait, il ne reste que peu d’agents antimicrobiens effectifs contre certains microbes multirésistants. Les scientifiques sont donc à la recherche de nouveaux produits antimicrobiens. Cette recherche a évalué l’activité antimicrobienne de substances naturelles provenant de plantes originaires du Nord de l’Ontario. Vingt-cinq extraits, dix fractions et dix-neuf composés purs ont été testés contre des microbes pathogènes, soientEscherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa et Candida albicans. L’activité antimicrobienne des produits naturels a été observée en utilisant la technique de dosage sur microplaque qui emploie le résazurin, et la concentration minimale inhibitrice (CMI) des produits a été déterminée. Afin de démontrer que l’activité antimicrobienne des substances naturelles n’était pas limitée à une seule espèce, certains composés purs ont été testés contre des microbes secondaires, soient Streptococcus lactis, Mycobacterium phlei et Schizosaccharomyces octosporus. Quatre extraits de plantes (Chimaphila umbellata, Betula papyrifera, Rhus typhina et Fraxinus pennsylvanica) et six composés purs (acide gallique, éthyle gallate, acide cafféique, acide synapique, acide gentisique et acide chlorogénique) ont démontré une activité antibactérienne ou antifongique. Ces résultats démontrent que ces produits naturels ont le potentiel d’être développés en nouveaux agents antimicrobiens

Non-steroidal anti-inflammatory drugs in cancer prevention and therapy

Long-term use of non-steroidal anti-inflammatory drugs (NSAIDs) can be regarded as an effective approach for cancer chemoprevention, as demonstrated by a bulk of clinical and experimental evidence. However, the clinical use of these drugs as chemopreventive agents is limited by many open questions about the optimal drug, dose, duration of therapy and knowledge about the mechanism(s) by which these drugs act. In particular, the recent data on cardiovascular toxicity of coxibs has posed some limitations on the use of NSAIDs for cancer chemoprevention in the general population. The situation is different in certain genetically susceptible subgroups, such as in individuals with genetic mutations associated with hereditary nonpolyposis colon cancer (HNPCC) or familiar adenomatous polyps (FAP) in whom lifetime risk increases up to 70-90% and in whom the benefit of a chemopreventive drug might justify its use even in the presence of adverse effects

Interleukin-2 inhalation therapy in renal cell cancer: a case report and review of the literature

Renal cell carcinoma (RCC) is the most common malignancy of the kidney. One third of RCC presents metastatic disease at the time of diagnosis, usually leading to a fatal outcome. Small response rates were seen with most cytotoxic agents including gemcitabine and vinorelbine, whereas systemic therapy with high doses of interleukin 2 (IL-2) has been shown to provide durable complete remissions. However, in consideration of its severe toxicity, IL-2 immunotherapy is restricted to selected patients. Aerosol IL-2 has been introduced as an alternative therapy in cancer patients. However, only very few data are available on its use in patients with pulmonary metastatic RCC. This paper briefly summarizes current clinical experience with the use of inhaled IL-2 therapy, either as a single therapy or in combination with other treatments. In addition, we report on a male patient with pulmonary metastasized RCC who achieved a durable complete response to combined gemcitabine/vinorelbine and interleukin-2 inhalation therapy

Local and system mechanisms for action execution and observation in parietal and premotor cortices

The action observation network (AON) includes a system of brain areas largely shared with action execution in both human and nonhuman primates. Yet temporal and tuning specificities of distinct areas and of physiologically identified neuronal classes in the encoding of self and others’ action remain unknown. We recorded the activity of 355 single units from three crucial nodes of the AON, the anterior intraparietal area (AIP), and premotor areas F5 and F6, while monkeys performed a Go/No-Go grasping task and observed an experimenter performing it. At the system level, during task execution, F6 displays a prevalence of suppressed neurons and signals whether an action has to be performed, whereas AIP and F5 share a prevalence of facilitated neurons and remarkable target selectivity; during task observation, F5 stands out for its unique prevalence of facilitated neurons and its stronger and earlier modulation than AIP and F6. By applying unsupervised clustering of spike waveforms, we found distinct cell classes unevenly distributed across areas, with different firing properties and carrying specific visuomotor signals. Broadly spiking neurons exhibited a balanced amount of facilitated and suppressed activity during action execution and observation, whereas narrower spiking neurons showed more mutually facilitated responses during the execution of one’s own and others’ action, particularly in areas AIP and F5. Our findings elucidate the time course of activity and firing properties of neurons in the AON during one’s own and others’ action, from the system level of anatomically distinct areas to the local level of physiologically distinct cell classes