191 research outputs found
Residual Stresses in Cold Formed Steel Sections
Initial or residual stresses are considered one of the major factors that affect the design of the cold-formed steel sections, since they could reach 50% of the yield stress of the material. As part of a comprehensive experimental program on the use of cold-formed steel sections in transmission towers, an investigation on the magnitude and distribution of residual stresses in cold-formed steel sections was undertaken. The study involved 83 tests using two nondestructive methods, and two destructive methods, to determine the magnitude and distribution of residual stresses. The paper summarizes the results from this investigation and outlines a number of implications for the design of cold-formed sections
Long-term treatment of osteoporosis: safety and efficacy appraisal of denosumab
Denosumab is a fully human monoclonal antibody to the receptor activator of nuclear factor-κB ligand (RANKL), a member of the tumor necrosis factor receptor superfamily essential for osteoclastogenesis. Denosumab treatment is associated with a rapid, sustained, and reversible reduction in bone turnover markers, a continuous marked increase in bone mineral density at all sites, and a marked decrease in the risk of vertebral, hip, and nonvertebral fractures in women with postmenopausal osteoporosis. Therefore, it could be considered as an effective alternative to previous bisphosphonate treatment as well as first-line treatment of severe osteoporosis. Cost-effectiveness studies support this suggestion. In addition, denosumab seems to be the safest treatment option in patients with impaired renal function. Denosumab is characterized by reversibility of its effect after treatment discontinuation, in contrast with bisphosphonates. Large-scale clinical trials, including the extension of FREEDOM trial for up to 5 years, are reassuring for its safety. However, given its brief post-market period, vigilance regarding adverse events related to putative RANKL inhibition in tissues other than bone, as well as those related to bone turnover oversuppression, is advised
The use of a combined bipedicled axial perforator based fasciocutaneous flap for the treatment of a traumatic diabetic foot wound: a case report
The axial and perforator vascularised fasciocutaneous flaps are reliable and effective treatment methods for covering lower limb post-traumatic, septic, Charcot, and diabetic foot wounds. The authors describe the unique utilisation of a hybrid flap as an axial-perforator flap combination for the treatment of a traumatic diabetic foot wound
Polymorph screening studies of oxcarbazepine : twisted habit in crystals of the elusive form III
Crystal structures exhibiting twisted morphology have been observed at the nanoscale, mesoscale, and macroscale and are challenging to characterise structurally because of their lack of long-range translational symmetry [1]. Crystal structure prediction (CSP) studies of an active pharmaceutical ingredient’s lattice energy landscape are often utilised for assisting experimentalists in identifying and characterising novel polymorphic forms that are thermodynamically feasible, including ones that crystallise with twisted morphologies [2-4]. Oxcarbazepine (OXCBZ) is a commercially available pharmaceutical used for the treatment of epilepsy and three polymorphic forms have been reported, two of which (form I and form II) are known to crystallise in the monoclinic space groups P21/c and P21 respectively [5]. Form III of OXCBZ was originally prepared by slow evaporation from methanol solutions that contained polymer additives but structure solution was not possible because of the small size and poor quality of the crystals. Herein, we present experimental protocols for the crystallization of OXCBZ III from both solution and the vapour phase. In our work, we combined CSP studies of OXCBZ with physical vapour deposition studies and solution-based polymorph screening experiments. Needle-like and fibre-like crystals of OXCBZ III exhibiting variable twisted habit emerged from vapour deposition of OXCBZ onto metallic substrates. Scanning electron and atomic force microscopy studies have been carried out to obtain an insight into the mechanism of formation and growth of the twisted OXCBZ III crystals over the course of the deposition process
High Strength Bolts for Bridges
DTFH61-85-C-00174An extensive experimental program was conducted to evaluate the performance of both black and galvanized high strength bolts for bridges. Seventy two a325 black bolts, 145 hot dip galvanized a325 bolts, 85 mechanically galvanized a325 bolts, and 83 black a490 bolts from several different suppliers, were tested under direct and torqued tension in order to evaluate the current installation practices and astm standard requirements for high strength bolts and to develop guidelines which will ensure proper installation and satisfactory performance of these bolts. An important parameter in the test program was the thread conditions of the bolts and nuts. Four thread conditions were examined: as received, cleaned, weathered and lubricated. Several types of lubricants were considered in the course of the experimental program. The results indicate that a great deal of the problems associated with the performance of high strength bolts lies in the vagueness of the current astm standards and the failure of the bolt suppliers to follow the requirements stated in these standards. A major recommendation in this study is to establish a unified standard which will cover the performance of fastener assemblages (bolt nut washer) under the responsibility of one committee. Guidelines for proper installation of high strength bolts are also given
Student perception of two different simulation techniques in oral and maxillofacial surgery undergraduate training
Successful computationally directed templating of metastable pharmaceutical polymorphs
A strategy of using crystal structure prediction (CSP) methods to determine which, if any, isostructural template could facilitate the first crystallization of a predicted polymorph by vapor deposition is extended to the fenamate family. Mefenamic acid (MFA) and tolfenamic acid (TFA) are used as molecules with minimal chemical differences, whereas flufenamic acid (FFA) shows greater differences in the substituents. The three crystal energy landscapes were calculated, and periodic electronic structure calculations were used to confirm the thermodynamic plausibility of possible isostructural polymorphs to experimentally obtainable crystals of the other molecules. As predicted, a new polymorph, TFA form VI, was found by sublimation onto isomorphous MFA form I, using a recently developed technique. MFA and TFA form a continuous solid solution with the structure of MFA I and TFA VI at the limits, but the isomorphous MFA/FFA solid solution does not extended to a new polymorph of FFA. The novel solid solution structure of TFA and FFA was found, and a new isomorphous polymorph TFA VII was found by sublimation onto this new solid solution template. Sublimation of TFA onto a metal surface at the early stage of deposition gave TFA form VIII. We rationalize the formation of new polymorphs of only TFA
Flexural strength of acrylic resin repairs processed by different methods: water bath, microwave energy and chemical polymerization
European survey on criteria of aesthetics for periodontal evaluation: The ESCAPE study
Objective:
The ESCAPE multicentre survey was designed to (a) compare the agreement of three relevant aesthetic scoring systems among different centres, and (b) evaluate the reproducibility of each question of the questionnaires. /
Materials and Methods:
EFP centres (n = 14) were involved in an e‐survey. Forty‐two participants (28 teachers, 14 postgraduate students) were asked to score the one‐year aesthetic outcomes of photographs using the Before–After Scoring System (BASS), the Pink Esthetic Score (PES) and the Root coverage Esthetic Score (RES). Mean values of kappa statistics performed on each question were provided to resume global agreement of each method. /
Results:
Between teachers, a difference of kappa ≥ 0.41 (p = .01) was found for BASS (75%) and PES (57%). Similarly, RES (84%) and PES (57%) were different (p < .001). No difference was found between BASS (75%) and RES (84%). No difference was found between students, whatever the scoring system. Questions of each scoring system showed differences in their reproducibility. /
Conclusions:
The outcomes of this study indicate that BASS and RES scoring systems are reproducible tools to evaluate aesthetic after root coverage therapies between different centres. Among the various variables, lack of scar, degree of root coverage, colour match and gingival margin that follows the CEJ show the best reliability
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