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Introduction
Published in Armen S. Casparian, Gergely Sirokman, Ann O. Omollo, Rapid Review of Chemistry for the Life Sciences and Engineering, 2021
Armen S. Casparian, Gergely Sirokman, Ann O. Omollo
Diffusion is the migration and mixing of molecules of different substances as a result of a concentration gradient across a fixed space and random molecular motion. Effusion is the escape of gas molecules of a single substance through a tiny orifice (pinhole) of a vessel holding the gas. Graham’s Law of Effusion states: The rates of effusion of two different gases escaping, A and B, are inversely proportional to the square roots of their molar masses: EffusionRateAEffusionRateB=MMBMMA
G
Published in Carl W. Hall, Laws and Models, 2018
Keywords: conduction, heat transfer, thermal, streamline GRAETZ, Leo P., 1856-1941, German physicist Sources: Bolz, R. E. and Tuve, G. L. 1970; Jerrard, H. G. and McNeill, D. B. 1992; Land, N. S. 1972; Parker, S. P. 1992; Perry, R. H. 1967; Potter, J. H. 1967; Rohsenow, W. M. and Hartnett, J. P. 1973. See also PRANDTL; REYNOLDS GRAHAM LAW OF DIFFUSION (1831) The rates of diffusion of various gases vary inversely as the square roots of their densities or their molecular weights, at constant temperature and pressure: r1/r2 = d21/2/d11/2 = M21/2/M11/2 where r = rate of diffusion d = density M = molecular weight Keywords: densities, diffusion, gases, molecular weight GRAHAM, Thomas, 1805-1869, Scottish physical chemist Sources: Honig, J. M. 1953; Landau, S. I. 1986; Mandel, S. 1969; Stedman, T. L. 1976; Thewlis, J. 1961-1964. GRAHAM LAW OF EFFUSION (1829) The relative rates of effusion of different gases under the identical temperature and pressure are inversely proportional to the square roots of their densities. Keywords: densities, effusion, gases, pressure, temperature
Prognostic value of renal failure in patients undergoing transvenous lead extraction: single centre experience and systematic review of the literature
Published in Expert Review of Medical Devices, 2022
Giulia Massaro, Alberto Spadotto, Luca Canovi, Cristian Martignani, Matteo Ziacchi, Andrea Angeletti, Nazzareno Galie, Giuseppe Boriani, Mauro Biffi, Igor Diemberger
We enrolled all patients who underwent TLE at Cardiology Unit, S.Orsola-Malpighi Polyclinic, University of Bologna between March 2011 and April 2020. Primary endpoints were 30-day and 1-year mortality after TLE. Before TLE procedure, each patient underwent blood cultures, transthoracic echocardiogram (TTE) and transesophageal echocardiogram (TEE), to assess ventricular ejection fraction (EF) and presence of intracardiac vegetations or valvular dysfunctions. After TLE procedure, a TEE was repeated to evaluate EF and presence of pericardial effusion, ghosts or valvular dysfunctions [19]. In most cases, 18F-FDG PET/CT was performed before lead extraction, to better identify infection extension. Antibiotic therapy was personalized based on microbiological cultures, after consultation with an infectious disease specialist. TLE procedure was performed in hybrid haemodynamic/surgery room by expert electrophysiologists. Obtained samples were sent to microbiological laboratory for analysis. After hospital discharge, patients were followed up by office visits at 6 and 12 months after TLE procedure, and then every year up to 5 years. Pre-procedural collected data were age, gender, clinical history, comorbidities, CIED characteristics, indication for TLE, blood tests (including microbiological), electrocardiogram, echocardiogram and pharmacological therapy. Procedural data considered tools and techniques used for TLE, radiological and clinical success, and intra-procedural complications. Post-procedural evaluations included: blood tests (including microbiological), echocardiogram, complications, infectious relapse, CIED re-implantation and clinical outcomes. All patients signed informed consent for inclusion in our observational prospective registry of candidates to TLE, approved by our Ethical Committee.
Transcatheter valve-in-valve implantation for degenerated bioprosthetic aortic and mitral valves – an update on indications, techniques, and clinical results
Published in Expert Review of Medical Devices, 2021
Michele Gallo, Michel Pompeu B. O. Sá, Ilias P. Doulamis, Nabil Hussein, Pietro L. Laforgia, Polydoros N. Kampaktsis, Ana Paula Tagliari, Enrico Ferrari
After V–in-V implantation, echocardiography is typically used to confirm appropriate transcatheter valve position, function and assess for complications. Complications such as intravalvular and paravalvular regurgitation, decrease of ventricular function, and new pericardial effusion can be promptly diagnosed. When more than mild paravalvular regurgitation is diagnosed secondary to under-deployment of the prothesis, repeat balloon dilation is recommended. In the event of malposition implantation of a second valve should be considered.
Long-term safety and efficacy of combined percutaneous LAA and PFO/ASD closure: a single-center experience (LAAC combined PFO/ASD closure)
Published in Expert Review of Medical Devices, 2019
Jiangtao Yu, Xiaoxia Liu, Junling Zhou, Xin Xue, Manuela Muenzel, P. Christian Schulze, Sven Moebius-Winkler, Thorsten Keil, Zhaohui Meng, Shaoyong Tang
The episodes of pericardial effusion/tamponade during LAAC were successfully treated with pericardiocentesis. The three cases of device thrombi during LAAC procedure all occurred in the access sheath, which were removed by washing with water and adding heparin.