64 research outputs found

    BYOD for physics lab: Studying Newton's law of cooling with a smartphone

    Get PDF
    In this paper we discuss a simple and inexpensive method to introduce students to Newton''s law of cooling using only their smartphones, according to the Bring-Your-Own-Device philosophy. A popular experiment in basic thermodynamics, both at a high-school and at University level, is the determination of the specific heat of solids and liquids using a water calorimeter, resourcing in many cases to a mercury thermometer. With our approach the analogical instrument is quickly turned into a digital device by analyzing the movement of the mercury with a video tracker. Tus, using very simple labware and the students'' smartphones or tablets, it is possible to observe the decay behavior of the temperature of a liquid lef to cool at room temperature. Te dependence of the time constant with the mass and surface of the liquid can be easily probed, and the results of the different groups in the classroom can be brought together to observe the linear dependence

    Quimio-radioterapia sequencial no carcinoma pulmonar não de pequenas células: estudo retrospectivo de 100 doentes

    Get PDF
    ABSTRACTCombined chemotherapy and radiotherapy has shown to be the correct treatment of unresectable non-small cell lung cancer, aier many years of poor survival figures with standard radiotherapy alone. It has also been demonstrated that the benefit of chemotherapy is mainly achieved if cisplatin-based schedules are used. The authors present a retrospective study of 100 cases of stage III non-small cell lung cancer treated with a sequential approach of chemotherapy and radiotherapy and evaluate median and overall survival, local progression-free survival and distant progression-free survival.The results of our series are quite similar to those published in literature.REV PORT PNEUMOL 2003; IX (3): 215-22

    SPEKcheck — fluorescence microscopy spectral visualisation and optimisation: a web application, javascript library, and data resource [version 1; referees: 3 approved]

    Get PDF
    Advanced fluorescence imaging methods require careful matching of excitation sources, dichroics, emission filters, detectors, and dyes to operate at their best. This complex task is often left to guesswork, preventing optimal dye:filter combinations, particularly for multicolour applications. To overcome this challenge we developed SPEKcheck, a web application to visualise the efficiency of the light path in a fluorescence microscope. The software reports values for the excitation efficiency of a dye, the collection efficiency of the emitted fluorescence, and a "brightness" score, allowing easy comparison between different fluorescent labels. It also displays a spectral plot of various elements in the configuration, enabling users to readily spot potential problems such as low efficiency excitation, emission, or high bleedthrough. It serves as an aid to exploring the performance of different dyes and filter sets

    XRD and FTIR analysis of Ti–Si–C–ON coatings for biomedical applications

    Get PDF
    Ti–Si–C–ON films were deposited by DC reactive magnetron sputtering using different partial pressure ratio of oxygen (pO2) and nitrogen (pN2). Compositional analysis revealed the existence of three different growth zones for the films; (I) N/Ti = 2.1 (high atomic ratio) and low oxygen content; (II) 0.76 < N/Ti < 2.1 (intermediate atomic ratio) and (III) N/Ti ≤ 0.12 (low ratio) and high oxygen content. For high N/Ti atomic ratio (N/Ti = 2.1) the XRD pattern exhibits reflections that correspond to a mixture of two different phases: a metallic-like Ti and a fcc NaCl type structure. Its electrical resistivity presents a metallic character and, consequently, has high infrared reflectivity. For the intermediate N/Ti ratio (0.76 < N/Ti < 2.1), the films crystallize in a B1-NaCl crystal structure typical for TiC0.2N0.8. Their FTIR spectra present C–N modes, besides the TiN ones, that indicate a progressive substitution of nitrogen by carbon atoms with increasing oxygen content (and lowering N/Ti ratio). For the highest oxygen content (and lower N/Ti ratio) the presence of the Ti–O–Ti stretching mode shows the formation of highly resistive Ti–O compounds consistent with the semiconductor character of this film. Biofilm formation as well as material cytotoxicity seemed to be related with the presence of the Ti

    Structural and mechanical properties of Ti–Si–C–ON for biomedical applications

    Get PDF
    Ti–Si–C–ON films were deposited by DC reactive magnetron sputtering using different partial pressure of oxygen (pO2) and nitrogen (pN2) ratio. Compositional analysis revealed the existence of two different growth zones for the films; one zone deposited under low pO2/pN2 and another zone deposited under high pO2/pN2. The films produced under low pO2/pN2 were deposited at a lower rate and presented a fcc structure, as well as, dense and featureless morphologies. The films deposited with high pO2/pN2, consequently higher oxygen content, were deposited at a higher rate and developed an amorphous structure. The structural changes are consistent with the hardness and Young's modulus evolution, as seen by the significant reduction of the hardness and influence on the Young's modulus by increasing pO2/pN2

    CryoSIM: super-resolution 3D structured illumination cryogenic fluorescence microscopy for correlated ultrastructural imaging

    Get PDF
    Rapid cryopreservation of biological specimens is the gold standard for visualizing cellular structures in their true structural context. However, current commercial cryo-fluorescence microscopes are limited to low resolutions. To fill this gap, we have developed cryoSIM, a microscope for 3D super-resolution fluorescence cryo-imaging for correlation with cryo-electron microscopy or cryo-soft X-ray tomography. We provide the full instructions for replicating the instrument mostly from off-the-shelf components and accessible, user-friendly, open-source Python control software. Therefore, cryoSIM democratizes the ability to detect molecules using super-resolution fluorescence imaging of cryopreserved specimens for correlation with their cellular ultrastructure.Funding: Wellcome Trust (091911/Z/11/Z, 096144/Z/11/Z, 105605/Z/14/Z, 107457/Z/15/Z, 203141/Z/16/Z, 209412/Z/17/Z); H2020Marie Skłodowska-Curie Actions (700184)

    SPEKcheck — fluorescence microscopy spectral visualisation and optimisation: a web application, javascript library, and data resource

    No full text
    Advanced fluorescence imaging methods require careful matching of excitation sources, dichroics, emission filters, detectors, and dyes to operate at their best. This complex task is often left to guesswork, preventing optimal dye:filter combinations, particularly for multicolour applications. To overcome this challenge we developed SPEKcheck, a web application to visualise the efficiency of the light path in a fluorescence microscope. The software reports values for the excitation efficiency of a dye, the collection efficiency of the emitted fluorescence, and a "brightness" score, allowing easy comparison between different fluorescent labels. It also displays a spectral plot of various elements in the configuration, enabling users to readily spot potential problems such as low efficiency excitation, emission, or high bleedthrough. It serves as an aid to exploring the performance of different dyes and filter sets

    Biological properties of Ti-Si-C-O-N thin films

    No full text
    The main aim of this work was to study the feasibility of new coatings for medical devices. Ti-Si-C-O-N films were deposited by DC unbalanced reactive magnetron sputtering, using different oxygen and nitrogen partial pressure ratios (pO2/pN2). Surface properties were also analysed. Staphylococcus epidermidis was used to study biofilm formation and cytotoxicity was determined using fibroblasts. Surface morphology changed with the increase of pO2/pN2. Samples of high hydrophobicity displayed opposite behaviour in terms of biofilm formation, presenting the highest and lowest biomass. Moreover, the sample with the highest Ti content was the one, with the lowest biofilm amount, raising the possibility of a correlation between Ti and biofilm formation capability. In fact, this sample also displayed the highest degree of cytotoxicity (near 35%). This work shows the feasibility of the proposed coatings and highlights the importance of joining together both biological properties (biofilm formation and cytotoxicity) with the surface characterization
    • …
    corecore