374 research outputs found

    Theoretical performance of cross-wind axis turbines with results for a catenary vertical axis configuration

    Get PDF
    A general analysis capable of predicting performance characteristics of cross-wind axis turbines was developed, including the effects of airfoil geometry, support struts, blade aspect ratio, windmill solidity, blade interference and curved flow. The results were compared with available wind tunnel results for a catenary blade shape. A theoretical performance curve for an aerodynamically efficient straight blade configuration was also presented. In addition, a linearized analytical solution applicable for straight configurations was developed. A listing of the computer program developed for numerical solutions of the general performance equations is included in the appendix

    Edge phonons in black phosphorus

    Get PDF
    Exfoliated black phosphorus has recently emerged as a new two-dimensional crystal that, due to its peculiar and anisotropic crystalline and electronic band structures, may have potentially important applications in electronics, optoelectronics and photonics. Despite the fact that the edges of layered crystals host a range of singular properties whose characterization and exploitation are of utmost importance for device development, the edges of black phosphorus remain poorly characterized. In this work, the atomic structure and the behavior of phonons near different black phosphorus edges are experimentally and theoretically studied using Raman spectroscopy and density functional theory calculations. Polarized Raman results show the appearance of new modes at the edges of the sample, and their spectra depend on the atomic structure of the edges (zigzag or armchair). Theoretical simulations confirm that the new modes are due to edge phonon states that are forbidden in the bulk, and originated from the lattice termination rearrangements.Comment: 15 pages, 4 figure

    Plasma Cytokines/Chemokines as Predictive Biomarkers For Lymphedema in Breast Cancer Patients

    Get PDF
    Breast cancer-related lymphedema (BCRL) occurs in ~ 40% of patients after axillary lymph node dissection (ALND), radiation therapy (RT), or chemotherapy. First-line palliative treatment utilizes compression garments and specialized massage. Reparative microsurgeries have emerged as a second-line treatment, yet both compression and surgical therapy are most effective at early stages of LE development. Identifying patients at the highest risk for BCRL would allow earlier, more effective treatment. Perometric arm volume measurements, near-infrared fluorescent lymphatic imaging (NIRF-LI) data, and blood were collected between 2016 and 2021 for 40 study subjects undergoing treatment for breast cancer. Plasma samples were evaluated using MILLIPLEX human cytokine/chemokine panels at pre-ALND and at 12 months post-RT. A Mann-Whitne

    Green Tattoo Pre-Operative Renal Embolization for Robotic-Assisted and Laparoscopic Partial Nephrectomy: A Practical Proof of a New Technique

    Get PDF
    Background: Our aim is to describe a new mixed indocyanine-non-adhesive liquid embolic agent (Onyx-18) pre-operative renal embolization technique for assisted-robotic and laparoscopic partial nephrectomy with near-infra-red fluorescence imaging. (2) Methods: Thirteen patients with biopsy-proven renal tumors underwent pre-operative mixed indocyanine–ethylene vinyl alcohol (EVOH) embolization (Green-embo) between June 2021 and August 2022. All pre-operative embolizations were performed with a super selective stop-flow technique using a balloon microcatheter to deliver an indocyanine-EVOH mixture into tertiary order arterial branch feeders and the intra-lesional vascular supply. Efficacy (evaluated as complete embolization, correct tumor mapping on infra-red fluorescence imaging and clamp-off surgery) and safety (evaluated as complication rate and functional outcomes) were primary goals. Clinical and pathological data were also collected. (3) Results: Two male and eleven female patients (mean age 72 years) received pre-operative Green-embo. The median tumor size was 29 mm (range 15–50 mm). Histopathology identified renal cell carcinoma (RCC) in 9 of the 13 (69%) patients, oncocytoma in 3 of the 13 (23%) patients and sarcomatoid RCC in 1 of the 13 (8%) patients. Lesions were equally distributed between polar, meso-renal, endo- and exophytic locations. Complete embolization was achieved in all the procedures. A correct green mapping was identified during all infra-red fluorescence imaging. All patients were discharged on the second day after the surgery. The median blood loss was 145 cc (10–300 cc). No significant differences were observed in serum creatinine levels before and after the embolization procedures. (4) Conclusions: The Green-tattoo technique based on a mixed indocyanine-non-adhesive liquid embolic agent (Onyx-18) is a safe and effective pre-operative embolization technique. The main advantages are the excellent lesion mapping for fluorescence imaging, reduction in surgical time, and definitive, complete and immediate tumor devascularization based on the deep Onyx-18 penetration, leading to a very low intra-operative blood loss

    Long-Term Prognostic Impact of Right Ventricular Dysfunction in Patients with COVID-19

    Get PDF
    The characteristics and clinical course of hospitalized patients with coronavirus disease 2019 (COVID-19) have been widely described, while long-term data are still poor. The aim of this study was to evaluate the long-term clinical outcome and its association with right ventricular (RV) dysfunction in hospitalized patients with COVID-19. This was a prospective multicenter study of consecutive COVID-19 patients hospitalized at seven Italian Hospitals from 28 February to 20 April 2020. The study population was divided into two groups according to echocardiographic evidence of RV dysfunction. The primary study outcome was 1-year mortality. The propensity score matching was performed to balance for potential baseline confounders. The study population consisted of 224 patients (mean age 69 \ub1 14, male sex 62%); RV dysfunction was diagnosed in 63 cases (28%). Patients with RV dysfunction were older (75 vs. 67 years, p < 0.001), had higher prevenance of coronary artery disease (27% vs. 11%, p = 0.003), and lower left ventricular ejection fraction (50% vs. 55%, p <0.001). The rate of 1-year mortality (67% vs. 28%; p 64 0.001) was significantly higher in patients with RV dysfunction compared with patients without. After propensity score matching, patients with RV dysfunction showed a worse long-term survival (62% vs. 29%, p <0.001). The multivariable Cox regression model showed an independent association of RV dysfunction with 1-year mortality. RV dysfunction is a relatively common finding in hospitalized COVID-19 patients, and it is independently associated with an increased risk of 1-year mortality

    Compact Ag@fe3o4 Core-shell Nanoparticles By Means Of Single-step Thermal Decomposition Reaction

    Get PDF
    A temperature pause introduced in a simple single-step thermal decomposition of iron, with the presence of silver seeds formed in the same reaction mixture, gives rise to novel compact heterostructures: brick-like Ag@Fe3O4 core-shell nanoparticles. This novel method is relatively easy to implement, and could contribute to overcome the challenge of obtaining a multifunctional heteroparticle in which a noble metal is surrounded by magnetite. Structural analyses of the samples show 4 nm silver nanoparticles wrapped within compact cubic external structures of Fe oxide, with curious rectangular shape. The magnetic properties indicate a near superparamagnetic like behavior with a weak hysteresis at room temperature. The value of the anisotropy involved makes these particles candidates to potential applications in nanomedicine.4Brown, M.A., Effects of the operating magnetic field on potential nmr contrast agents (1985) Magn. Reson. Imaging, 3, p. 3Renshaw, P.F., Owen, C.S., McLaughlin, A.C., Frey, T.G., Leigh, J.S., Ferromagnetic contrast agents: A new approach (1986) Magn. Reson. Med., 3, p. 217Kozissnik, B., Dobson, J., Biomedical applications of mesoscale magnetic particles (2013) MRS Bulletin, 38, p. 923Xu, C., Sun, S., New forms of superparamagnetic nanoparticles for biomedical applications (2013) Adv. Drug Delivery Rev., 65, p. 732Bao, G., Mitragotri, S., Tong, S., Multifunctional nanoparticles for drug delivery and molecular imaging (2013) Annu. Rev. Biomed. Eng., 15, p. 253Huang, K., Size-dependent localization and penetration of ultrasmall gold nanoparticles in cancer cells, multicellular spheroids, and tumors in vivo (2012) ACS Nano, 6, p. 4483Klitzing, K.V., The quantized hall effect (1986) Rev. Mod. Phys., 58, p. 519Batlle, X., Labarta, A., Finite-size effects in fine particles: Magnetic and transport properties (2002) J. Phys. D: Appl. Phys., 35, p. R15Zhu, H., Zhang, S., Huang, Y.X., Wu, L., Sun, S., Monodisperse m x)fe(3-x)o4 (m 5 fe, cu, co, mn) nanoparticles and their electrocatalysis for oxygen reduction reaction (2013) Nano Lett., 13, p. 2947Nguyen, T.D., Portraits of colloidal hybrid nanostructures: Controlled synthesis and potential applications (2013) Colloids Surf., B 103, p. 326Figueroa, S.J.A., Stewart, S.J., Rueda, T., Hernando, A., De La Presa, P., Thermal evolution of pt-rich fept/fe3o4 heterodimers studied using x-ray absorption near-edge spectroscopy (2011) J. Phys. Chem., C 115, p. 5500Zhang, L., Dou, Y.H., Gu, H.C., Synthesis of ag-fe3o4 heterodimeric nanoparticles (2006) J. Colloid Interf. Sci., 297, p. 660Zhang, L., Dong, W.F., Sun, H.B., Multifunctional superparamagnetic iron oxide nanoparticles: Design, synthesis and biomedical photonic applications (2013) Nanoscale, 5, p. 7664Wang, C., Yin, H., Dai, S., Sun, S., A general approach to noblemetal metal oxide dumbbell. Nanoparticles and their catalytic application for co oxidation (2010) Chem. Mater., 22, p. 3277Yu, S., Label-free immunosensor for the detection of kanamycin using ag-fe3o4 nanoparticles and thionine mixed graphene sheet (2013) Biosens. Bioelectron., 48, p. 224Huang, J., Crystal engineering and sers properties of ag-fe3o4 nanohybrids: From heterodimer to core-shell nanostructures (2011) J. Mater. Chem., 21, p. 17930Sun, L., He, J., Ren, D., An, S., Zhang, J., Facile one-step synthesis of ag@fe3o4 core-shell nanospheres. for reproducible sers substrates (2013) J. Mol. Struct., 1046, p. 74Morones, J.R., The bactericidal effect of silver nanoparticles (2005) Nanotechnology, 16, p. 2346Xu, R., Ag nanoparticles sensitize ir-induced killing of cancer cells (2009) Cell Research, 19, p. 1031Sotiriou, G.A., Pratsinis, S.E., Antibacterial activity of nanosilver ions and particles (2010) Environ. Sci. Technol., 44, p. 5649Seil, J., Webster, T., (2012) Int. J. Nanomed., 7, p. 2767Chen, Y., Gao, N., Jiang, J., Surface matters: Enhanced bactericidal property of core-shell ag-fe2o3 nanostructures to their heteromer counterparts from onepot synthesis (2013) Small, 9, p. 3242Muraca, D., Influence of silver concentrations on structural and magnetic properties of ag-fe3o4 heterodimer nanoparticles (2012) J. Nanosci. Nanotechnol., 12, p. 6961Rockenberger, J., Scher, E.C., Alivisatos, A.P., A new nonhydrolytic singleprecursor approach to surfactant-capped nanocrystals of transition metal oxides (1999) J. Am. Chem. Soc., 121, p. 11595Lopes, G., Ag-fe3o4 dimer colloidal nanoparticles: Synthesis and enhancement of magnetic properties (2010) J. Phys. Chem., C 114, p. 10148Roca, A.G., (2009), digital.csic.es/bitstream/10261/22726/1/Tesis-AlejandroGomez.pdf, Date of access: 01/06/2014Wiley, B., Sun, Y., Mayers, B., Xia, Y., Shape-controlled synthesis of metal nanostructures: The case of silver (2005) Chem. Eur. J., 11, p. 454Zhang, L., He, R., Gu, H.-C., Synthesis and kinetic shape and size evolution of magnetic nanoparticles (2006) Mater. Res. Bull., 41, p. 260Sun, S., Monodisperse mfe2o4 (m5fe, co,mn) nanoparticles (2014) J. Am. Chem. Soc., 126, p. 273Roca, A.G., Morales, M.P., O'Grady, K., Serna, C., Structural and magnetic properties of uniform magnetite nanoparticles prepared by high temperature decomposition of organic precursors (2006) Nanotechnology, 17, p. 2783Polte, J., Mechanism of colloidal silver nanoparticles: Analogies and differences to the growth of gold nanoparticles (2012) ACS Nano, 3, p. 5791Thanh, N.T.K., Maclean, N., Mahiddine, S., Mechanisms of nucleation and growth of nanoparticles in solution (2014) Chem. Rev., 114, p. 7610Park, J., Ultra-large-scale syntheses of monodisperse nanocrystals (2004) Nat. Mater., 3, p. 891Moscoso, O., Physicochemical studies of complex silver-magnetite nanoheterodimers with controlled morphology J. Phys. Chem. CWilke, M., Farges, F., Petit, P.E., Brown, G.E., Martin, F., Oxidation state and coordination of fe in minerals: An fek-xanes spectroscopic study (2001) Am. Mineral., 86, p. 714Piquer, C., Effect of nature and particle size on properties of uniform magnetite and maghemite nanoparticles (2014) J. Phys. Chem., C 118, p. 1332Muscas, G., Magnetic properties of small magnetite nanocrystals (2013) J. Phys. Chem., C 117, p. 23378Verwey, E.J.W., Electronic conduction of magnetite (1939) Nature, 144, p. 327Verwey, E.J.W., Hayman, P.W., Electronic conductivity and transition point of magnetite (1941) Physica, 8, p. 979Muxworthy, A.R., McClelland, E., Review of the low-temperature magnetic properties of magnetite from a rock magnetic perspective (2000) Geophys. J. Int., 140, p. 101Shephered, J.P., Koenitzer, J.W., Aragón, R., Spalek, J., Honig, J.M., Heat capacity and entropy of nonstoichiometric magnetite fe3(1-d) o4: The thermodynamic nature of the verwey transition (1991) Phys. Rev. B, 43, p. 8461Newville, M.J., Exafs analysis using FEFF and FEFFIT (2011) J. Synchrotron Radiat, 8, p. 96Wilke, M., Farges, F., Petit, P.E., Brown, G.E., Martin, F., Oxidation state and coordination of fe in minerals: An fe k-xanes study (2001) Am. Mineral., 86, p. 71

    The modeling of a tokamak plasma discharge, from first principles to a flight simulator

    Get PDF
    A newly developed tool to simulate a tokamak full discharge is presented. The tokamak \u27flight simulator\u27 Fenix couples the tokamak control system with a fast and reduced plasma model, which is realistic enough to take into account several of the plasma non-linearities. A distinguishing feature of this modeling tool is that it only requires the pulse schedule (PS) as input to the simulator. The output is a virtual realization of the full discharge, whose time traces can then be used to judge if the PS satisfies control/physics goals or needs to be revised. This tool is envisioned for routine use in the control room before each pulse is performed, but can also be used off-line to correct PS in advance, or to develop and validate reduced models, control schemes for future machines like a commercial reactor, simulating realistic actuators and sensors behavior

    Drug–drug interactions in vestibular diseases, clinical problems, and medico-legal implications

    Get PDF
    Peripheral vestibular disease can be treated with several approaches (e.g., maneuvers, surgery, or medical approach). Comorbidity is common in elderly patients, so polytherapy is used, but it can generate the development of drug–drug interactions (DDIs) that play a role in both adverse drug reactions and reduced adherence. For this reason, they need a complex kind of approach, considering all their individual characteristics. Physicians must be able to prescribe and deprescribe drugs based on a solid knowledge of pharmacokinetics, pharmacodynamics, and clinical indications. Moreover, full information is required to reach a real therapeutic alliance, to improve the safety of care and reduce possible malpractice claims related to drug–drug interactions. In this review, using PubMed, Embase, and Cochrane library, we searched articles published until 30 August 2021, and described both pharmacokinetic and pharmacodynamic DDIs in patients with vestibular disorders, focusing the interest on their clinical implications and on risk management strategies
    corecore