Search results for "Statics"
showing 10 items of 141 documents
Transfer Free Energies of Test Proteins Into Crowded Protein Solutions Have Simple Dependence on Crowder Concentration
2019
The effects of macromolecular crowding on the thermodynamic properties of test proteins are determined by the latter's transfer free energies from a dilute solution to a crowded solution. The transfer free energies in turn are determined by effective protein-crowder interactions. When these interactions are modeled at the all-atom level, the transfer free energies may defy simple predictions. Here we investigated the dependence of the transfer free energy (Δμ) on crowder concentration. We represented both the test protein and the crowder proteins atomistically, and used a general interaction potential consisting of hard-core repulsion, non-polar attraction, and solvent-screened electrostati…
A Multilayered Plate Theory with Transverse Shear and Normal Warping Functions
2016
A multilayered plate theory which takes into account transverse shear and normal stretching is presented. The theory is based on a seven-unknowns kinematic field with five warping functions. Four warping functions are related to the transverse shear behaviour, the fifth is related to the normal stretching. The warping functions are issued from exact three-dimensional solutions. They are related to the variations of transverse shear and normal stresses computed at specific points for a simply supported bending problem. Reddy, Cho-Parmerter and (a modified version of) Beakou-Touratier theories have been retained for comparisons. Extended versions of these theories, able to manage the normal s…
Aluminum Chloride versus Electrocauterization in Periapical Surgery: A Randomized Controlled Trial
2019
The aim of this study was to evaluate the efficacy of 2 hemostatic agents in periapical surgery and its relationship with patient- and tooth-dependent variables.A prospective study was designed with 2 randomized parallel groups established according to the hemostatic agent used: aluminum chloride or electrocauterization. The surgeon and 2 independent blinded observers examined the initial and final bleeding and recorded it as 0 (no hemorrhage control), 1 (slight but apparent intermittent bleeding), or 2 (complete hemorrhage control). The following patient- and tooth-dependent variables were collected: sex, age, smoking habit, plaque index, and position.Sixty patients with a periapical lesio…
The important impact of dental care on haemostatic treatment burden in patients with mild haemophilia
2022
Background: Mild haemophilia (MH) is mainly characterized by haemorrhages secondary to surgery/invasive procedures or trauma. Haemostatic treatment in MH ranges from on demand to short prophylaxis according to the type of bleeding events and the basal clotting factor level. Oral surgery and dental extractions can represent a frequent haemostatic challenge in MH requiring appropriate treatment. However, only few studies on limited numbers of patients are available in the literature regarding the implications of dental management in patients with MH. Objectives: The purpose of the study was to evaluate the impact of dental care on the burden of haemostatic treatment in patients affected by MH…
Influence of hemostatic agents upon the outcome of periapical surgery: dressings with anesthetic and vasoconstrictor or aluminum chloride
2011
Objective: To evaluate the effects of different hemostatic agents upon the outcome of periapical surgery. Design: A retrospective study was made of patients subjected to periapical surgery between 2006-2009 with the ultrasound technique and using MTA as retrograde filler material. We included patients with a minimum follow-up of 12 months, divided into two groups according to the hemostatic agent used: A) dressings impregnated in anesthetic solution with adrenalin; or B) aluminum chloride paste (Expasyl™). Radiological controls were made after 6 and 12 months, and on the last visit. The global evolution scale proposed by von Arx and Kurt (1999) was used to establish the outcome of periapica…
Management of dental extraction in patients with Haemophilia A and B: a report of 58 extractions
2013
Objectives: Patients with inherited bleeding disorders are at high risk of bleeding following oral surgery and present challenges to the oral surgeons. Aim of this study was to report our experience in dental extraction in patients exhibiting Haemophilia A and B between 2007 and 2012. Patient and Methods: 58 dental extractions in 15 patients during 19 interventions were performed. Replacement therapy with recombinant and plasma-derived factor VIII and IX was applied systematically in combination with antifibrinolytic treatment and local haemostatic measures. The following data were recorded: type of surgery, applied local haemostatic measures, general substitution, systemic antifibrinolytic…
Hemostatic Agents in Periapical Surgery: A Randomized Study of Gauze Impregnated in Epinephrine versus Aluminum Chloride
2016
Abstract Introduction Adequate bleeding control is essential for the success of periapical surgery. The aim of this study was to evaluate the effects of 2 hemostatic agents on the outcome of periapical surgery and their relationship with patient and teeth parameters. Methods A prospective study was designed with 2 randomized parallel groups, depending on the hemostatic agent used: gauze impregnated in epinephrine (epinephrine group) and aluminum chloride (aluminum chloride group). The analysis of the hemorrhage control was judged before and after the application of the hemostatic agents by the surgeon, and 2 examiners independently recorded it as adequate (complete hemorrhage control) or in…
A gelatin-thrombin matrix topical hemostatic agent (Floseal) in combination with harmonic scalpel is effective in patients undergoing total thyroidec…
2016
BACKGROUND: Hemostasis during thyroidectomy is essential; however, the safest, most efficient, and most cost-effective way to achieve this is unclear. This randomized, multicenter, single-blind, prospective study evaluated the efficacy and safety of using different hemostatic approaches in patients undergoing total thyroidectomy. METHODS: Patients aged ≥18 to 70 years were randomized to Floseal + a harmonic scalpel (HS), Floseal alone, HS alone, or standard total thyroidectomy. Primary endpoint was 24-hour drain output. Secondary endpoints included surgery duration and complications. RESULTS: Two hundred and six patients were randomized to Floseal + HS (n = 52), Floseal alone (n = 54), HS a…
Conductance and Ion Selectivity of a Mesoscopic Protein Nanopore Probed with Cysteine Scanning Mutagenesis
2005
Nanometer-scale proteinaceous pores are the basis of ion and macromolecular transport in cells and organelles. Recent studies suggest that ion channels and synthetic nanopores may prove useful in biotechnological applications. To better understand the structure-function relationship of nanopores, we are studying the ion-conducting properties of channels formed by wild-type and genetically engineered versions of Staphylococcus aureus alpha-hemolysin (alphaHL) reconstituted into planar lipid bilayer membranes. Specifically, we measured the ion selectivities and current-voltage relationships of channels formed with 24 different alphaHL point cysteine mutants before and after derivatizing the c…
Physical origin of Na+/Cl− selectivity of tight junctions between epithelial cells. Nonlocal electrostatic approach
2020
Abstract Tight junctions (TJs) of epithelial cells play a key role in regulation of the ion exchange between NaCl solutions separated by the layer of these cells. Their functioning is based on a strong difference in the permeabilities of these channels for Na+ and Cl− ion migrational fluxes owing to specific properties of the protein network inside TJs. It has been assumed in this study that this phenomenon originates from combination of two effects related to this specific TJ protein (claudin) which segments are partially located inside the TJ space. First, their ionogenic groups create a negative charge distributed inside TJs, thus inducing a difference between the Na+ and Cl− concentrati…