102 research outputs found

    Comparing the enhanced sensing interfaces of differently oriented carbon nanotubes onto silicon for bio-chip applications

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    Carbon nanotubes improve the sensitivity of electrochemical biochips. An optimized integration of the nano/bio/CMOS interface is required to realize accurate and low-cost sensors for applications in personalized medicine. The nanotubes orientation on the chip is a key parameter. The role of the sidewalls and the tips surface on the electro-activity of the nanosensor is still subject of debate in the literature. In this paper, a comparison between vertical densely-packed and randomlyoriented carbon nanotubes directly growth on silicon wafer is proposed in order to identify the best nano-system for biosensing purposes. The comparison is done by using contact-angle measurements, energy dispersive X-ray analysis and electrochemical voltammetry

    Comparing Sensitivities of Differently Oriented Multi-walled Carbon Nanotubes Integrated on Silicon Wafer for Electrochemical Biosensors

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    In this study, we report on multi-walled carbon nanotubes fabricated on silicon substrate with four different orientations via chemical vapor deposition. It is well-known that chemical treatments improve the nanotube electrochemical reactivity by creating edge-like defects on their exposed sidewalls. Before use, we performed an acid treatment on carbon nanotubes. To prove the effect of the treatment on these nanostructured electrodes, contact angles were measured. Then, sensitivities and detection limits were evaluated performing cyclic voltammetry. Two target molecules were used: potassium ferricyanide, an inorganic electroactive molecule, and hydrogen peroxide that is a product of reactions catalyzed by many enzymes, such as oxidases and peroxidases. Carbon nanotubes with tilted tips become hydrophilic after the treatment showing a contact angle of 22◦ ± 2◦. This kind of electrode has shown also the best electrochemical performance. Sensitivity and detection limit values are 110.0 ± 0.5 uA/(mM cm2) and 8 uM for potassium ferricyanide solutions and 16.4 ± 0.1 uA/(mM cm2) and 24 uM using hydrogen peroxide as target compound. Considering the results of wettability and voltammetric measurements, nanotubes with tilted tips-based electrodes are found to be the most promising for future biosensing application

    Comparison of Two Different Carbon Nanotube-based Surfaces with Respect to Potassium Ferricyanide Electrochemistry

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    This paper describes the electrochemical investigation of two multi-walled carbon nanotube-based electrodes using potassium ferricyanide as a benchmark redox system. Carbon nanotubes were fabricated by chemical vapor deposition on silicon wafer with camphor and ferrocene as precursors. Vertically-aligned as well as islands of horizontally-randomly-oriented carbon nanotubes were obtained by varying the growth parameters. Cyclic voltammetry was the employed method for this electrochemical study. Vertical nanotubes showed a slightly higher kinetic. Regarding the sensing parameterswe found a sensitivity for vertical nanotubes almost equal to the sensitivity obtainedwith horizontally/randomly oriented nanotubes (71.5±0.3 μA/(mM cm2) and 62.8±0.3 μA/(mMcm2), respectively). In addition, values of detection limit are of the same order of magnitude. Although tip contribution to electron emission has been shown to be greatly larger than the lateral contribution on single carbon nanotubes per unit area, the new findings reported in this paper demonstrate that the global effects of nanotube surface on potassium ferricyanide electrochemistry are comparable for these two types of nanostructured surfaces

    Environmental Education Projects in rural education. Experiences destined to work outside the classroom, to recognize the nearby environment, its biodiversity and conservation

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    Huerta orgánica escolar, desecador solar, producción de jugos naturales, observación, identificación y relevamiento de la biodiversidad local, estimación del microclima, elaboración de plantines forestales y campamentos educativos, son todos proyectos desarrollados interdisciplinariamente en el Núcleo Rural de Enseñanza Secundaria Orientada N°1581, de la localidad de La Loma; paraje muy pequeño, ubicado en la zona norte de la provincia de Santa Fe, Argentina. Todos los trabajos apuestan por el fortalecimiento de la Educación Ambiental, y por comprender las relaciones entre la salud de las personas y la del medio ambiente.Organic school garden, solar desiccator, production of natural juices, observation, identification and survey of local biodiversity, estimation of the microclimate, preparation of forest seedlings and educational camps, are all projects that we carry out interdisciplinary in the Rural Nucleus of Oriented Secondary Education N ° 1581, from the town of La Loma; very small place, located in the northern part of the province of Santa Fe, Argentina. Projects that are committed to strengthening Environmental Education, and to understanding the relationships that exist between people's health and environmental health

    dosimetry methods in boron neutron capture therapy

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    Dosimetry studies have been carried out at thermal and epithermal columns of LVR- 15 research reactor for investigating the spatial distribution of gamma dose, fast neutron dose and thermal neutron fluence. Two different dosimetry methods, both based on solid state detectors, have been studied and applied and the accuracy and consistency of the results have been inspected. One method is based on Fricke gel dosimeters that are dilute water solutions and have good tissue equivalence for neutrons and also for all the secondary radiations produced by neutron interactions in tissue or water phantoms. Fricke gel dosimeters give the possibility of separating the various dose contributions, i.e. the gamma dose, the fast neutron dose and the dose due to charged particles generated during thermal neutron reactions by isotopes having high cross section, like 10B. From this last dose, thermal neutron fluence can be obtained by means of the kerma factor. The second method is based on thermoluminescence dosimeters. In particular, the developed method draw advantage from the different heights of the peaks of the glow curve of such phosphors when irradiated with photons or with thermal neutrons. The results show that satisfactory results can be obtained with simple methods, in spite of the complexity of the subject. However, the more suitable dosimeters and principally their utilization and analysis modalities are different for the various neutron beams, mainly depending on the relative intensities of the three components of the neutron field, in particular are different for thermal and epithermal columns

    Visualization and analysis of cellular & Twitter data using qgis

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    The study is to understand individual presence and movement in Friuli Venezia Giulia region. It is important for tourism planning, hazard management, business marketing, implementing government lifetime policies and benefit. The aim of this study is achieved by advanced web 2.0 applications. We need real time and geo-located data to monitor the inflow of tourist and to come up with effective promoting and benefiting plans for tourism, the evacuation and mitigation strategies during hazards to protect social life and environment with less infrastructure damage, marketing plans for advertising or selling of products. Despite wide spread success in predicting specific aspects of human behavior by social media information, a little attention is given to twitter and cell phone data. Accessibility to detailed human movements with fine spatial and temporal granularity is challenging due to confidentiality and safety reasons. With rapid development of web2.0 applications people can post about events, share opinion and emotions online. Using twitter data, how short term travelers, such as tourists, can be recognized and how their travel pattern can be analyzed. Study of finding tourist dynamics such as arriving and outgoing of tourist, sum of trips, sum of days and night spent, number of unique visitors, country of residence, main destination, secondary destination, transits pass through, repeat visits are achieved using CDR (call detail records) and DDR (data detail records)

    Rationale and Design of the PARTHENOPE Trial: A Two-by-Two Factorial Comparison of Polymer-Free vs. Biodegradable-Polymer Drug-Eluting Stents and Personalized vs. Standard Duration of Dual Antiplatelet Therapy in All-Comers Undergoing PCI.

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    BACKGROUND Over the past few decades, percutaneous coronary intervention (PCI) has undergone significant advancements as a result of the combination of device-based and drug-based therapies. These iterations have led to the development of polymer-free drug-eluting stents. However, there is a scarcity of data regarding their clinical performance. Furthermore, while various risk scores have been proposed to determine the optimal duration of dual antiplatelet therapy (DAPT), none of them have undergone prospective validation within the context of randomized trials. DESIGN The PARTHENOPE trial is a phase IV, prospective, randomized, multicenter, investigator-initiated, assessor-blind study being conducted at 13 centers in Italy (NCT04135989). It includes 2,107 all-comers patients with minimal exclusion criteria, randomly assigned in a 2-by-2 design to receive either the Cre8 amphilimus-eluting stent or the SYNERGY everolimus-eluting stent, along with either a personalized or standard duration of DAPT. Personalized DAPT duration is determined by the DAPT score, which accounts for both bleeding and ischemic risks. Patients with a DAPT score <2 (indicating higher bleeding than ischemic risk) receive DAPT for 3 or 6 months for chronic or acute coronary syndrome, respectively, while patients with a DAPT score ≥2 (indicating higher ischemic than bleeding risk) receive DAPT for 24 months. Patients in the standard DAPT group receive DAPT for 12 months. The trial aims to establish the non-inferiority between stents with respect to a device-oriented composite endpoint of cardiovascular death, target-vessel myocardial infarction, or clinically-driven target-lesion revascularization at 12 months after PCI. Additionally, the trial aims to demonstrate the superiority of personalized DAPT compared to a standard approach with respect to a net clinical composite of all-cause death, any myocardial infarction, stroke, urgent target-vessel revascularization, or type 2 to 5 bleeding according to the Bleeding Academic Research Consortium criteria at 24-months after PCI. SUMMARY The PARTHENOPE trial is the largest randomized trial investigating the efficacy and safety of a polymer-free DES with a reservoir technology for drug-release and the first trial evaluating a personalized duration of DAPT based on the DAPT score. The study results will provide novel insights into the optimizing the use of drug-eluting stents and DAPT in patients undergoing PCI

    Colorectal surgery in Italy during the Covid19 outbreak: a survey from the iCral study group

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    Background The COVID19 pandemic had a deep impact on healthcare facilities in Italy, with profound reorganization of surgical activities. The Italian ColoRectal Anastomotic Leakage (iCral) study group collecting 43 Italian surgical centers experienced in colorectal surgery from multiple regions performed a quick survey to make a snapshot of the current situation. Methods A 25-items questionnaire was sent to the 43 principal investigators of the iCral study group, with questions regard- ing qualitative and quantitative aspects of the surgical activity before and after the COVID19 outbreak. Results Two-thirds of the centers were involved in the treatment of COVID19 cases. Intensive care units (ICU) beds were partially or totally reallocated for the treatment of COVID19 cases in 72% of the hospitals. Elective colorectal surgery for malignancy was stopped or delayed in nearly 30% of the centers, with less than 20% of them still scheduling elective colo- rectal resections for frail and comorbid patients needing postoperative ICU care. A significant reduction of the number of colorectal resections during the time span from January to March 2020 was recorded, with significant delay in treatment in more than 50% of the centers. Discussion Our survey confirms that COVID19 outbreak is severely affecting the activity of colorectal surgery centers partici- pating to iCral study group. This could impact the activity of surgical centers for many months after the end of the emergency
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