14 research outputs found
Subtalar instability
No full textSubtalar instability is a confusing yet important condition in patients with lateral ankle instability. The author will explore subtalar kinematics, and how they are closely related to the joint stability of the subtalar joint, both with respect to its intrinsic ligaments and its extrinsic ligaments. As subtalar instability is difficult to diagnose, this article will provide readers with a better understanding of its clinical presentation. Discussions will also include useful radiographic modalities and the most recent evidence regarding their accuracy. The last section discusses surgical options and what the readers need to know in order to make a decision
Finite element modelling of double skin composite slabs
No full text10.1016/S0168-874X(01)00093-2Finite Elements in Analysis and Design387579-599FEAD
A Survey on Usage and Diffusion of Project Risk Management Techniques and Software Tools in the Construction Industry
No full textThe area of Project Risk Management (PRM) has been extensively researched, and the utilization of various tools and techniques for managing risk in several industries has been sufficiently reported. Formal and systematic PRM practices have been made available for the construction industry. Based on such body of knowledge, this paper tries to find out the global picture of PRM practices and approaches with the help of a survey to look into the usage of PRM techniques and diffusion of software tools, their level of maturity, and their usefulness in the construction sector. Results show that, despite existing techniques and tools, their usage is limited: software tools are used only by a minority of respondents and their cost is one of the largest hurdles in adoption. Finally, the paper provides some important guidelines for future research regarding quantitative risk analysis techniques and suggestions for PRM software tools development and improvemen
The practice of risk management by cost consultants in Northern Ireland
No full textThis research endeavoured to explore the practice of risk management by cost consultants in Northern Ireland. It attempted to subjectively investigate the cost consultant’s appreciation of risk management practices and then further appraise the cost consultant’s understanding and usage of the theories and techniques available to manage risk under the risk management framework. A case study based approach involving five consultancy practices was adopted. A series of semi structured interviews (one per each case study) was carried out. The data collected was analysed using the Delphi technique. The practice of risk management for each organisation was documented using an analysis and evaluation of project documentation substantiated with interviews. The research indicated that consultants have a broad awareness of risk management but disparity exists on considering it as a core service. All consultants were unequivocal in identifying the need for an improved risk management framework. It was evident that there was a lack of knowledge of the array of risk identification and analysis techniques available. The research has established that there is a severe need to bridge the void between the theories and techniques used to manage risk and those which are implemented in practice. There is a necessity to train consultants in the practice of risk management and educate clients in the benefits of enforcing risk management practices as an integral part of project delivery
Protecting healthcare workers from COVID-19: learning from variation in practice and policy identified through a global cross-sectional survey
No full textAims The COVID-19 pandemic presents an unprecedented burden on global healthcare systems, and existing infrastructures must adapt and evolve to meet the challenge. With health sys- tems reliant on the health of their workforce, the importance of protection against disease transmission in healthcare workers (HCWs) is clear. This study collated responses from sever- al countries, provided by clinicians familiar with practice in each location, to identify areas of best practice and policy so as to build consensus of those measures that might reduce the risk of transmission of COVID-19 to HCWs at work. Methods A cross-sectional descriptive survey was designed with ten open and closed questions and sent to a representative sample. The sample was selected on a convenience basis of 27 senior surgeons, members of an international surgical society, who were all frontline workers in the COVID-19 pandemic. This study was reported according to the Standards for Reporting Qualitative Research (SRQR) checklist. Results Responses were received by all 27 surgeons from 22 countries across six continents. A number of the study respondents reported COVID-19-related infection and mortality in HCWs in their countries. Differing areas of practice and policy were identified and organ- ized into themes including the specification of units receiving COVID-19 patients, availa- bility and usage of personal protective equipment (PPE), other measures to reduce staff exposure, and communicating with and supporting HCWs. Areas more specific to surgery also identified some variation in practice and policy in relation to visitors to the hospital, the outpatient department, and in the operating room for both non-urgent and emergen- cy care. conclusion COVID-19 presents a disproportionate risk to HCWs, potentially resulting in a diminished health system capacity, and consequently an impairment to population health. Implementa- tion of these recommendations at an international level could provide a framework to reduce this burden.published_or_final_versio
Finite element modelling of shear connection for steel-concrete composite girders
No full textThe main objective of this thesis is to develop effective 3-dimensional finite element models to trace the behaviour of headed stud shear connectors in composite girders with
solid slabs and precast hollow core slabs. The finite element package ABAQUS was used to conduct the analysis. Push-off tests with both types of slabs were simulated
taking into consideration all material nonlinearities of the components. The models are able to predict the headed shear stud capacity, the load-slip characteristic of the shear connection and modes of failure. The results obtained show good agreement with specified data from Codes of practice and results of available numerical and
experimental literature. Parametric studies were carried out using both models to investigate the effects of the change in different parameters on the behaviour of shear
connections.
Full-scale push-off tests with solid and precast hollow core slabs have been carried out to verify the finite element models. The shear connection capacity, load-slip curves and modes of failure were detected from experimental investigation. Both numerical and experimental results were compared and good agreement has been achieved. The
comparison has shown that the model is able to predict accurately the behaviour of headed studs in composite girders with both types of slabs.
The non-linear load-slip characteristics of the headed shear stud connector obtained from FE models of push-off tests were used in modelling the structural behaviour of
composite steel-solid slab concrete and steel-precast hollow core slab girders. A finite element model has been developed for the analysis of each type. The models took into account the non-linear behaviour of concrete slab, steel beam and shear connectors. The accuracy and efficiency of the models have been demonstrated by comparing finite element results with available published experimental and numerical research. An effective parametric study for the evaluation of the effective width for steel-precast concrete slab composite girders is presented
The Diagnostic Potential of RNA Aptamers against the NS1 Protein of Dengue Virus Serotype 2
No full textDengue infection, caused by the dengue virus, is a global threat which requires immediate attention and appropriate disease management. The current diagnosis of dengue infection is largely based on viral isolation, RT-PCR and serology-based detection, which are time-consuming and expensive, and require trained personnel. For early diagnosis of dengue, the direct detection of a dengue antigenic target is efficacious, and one such target is NS1. NS1-based detection is primarily antibody-centric and is beset by drawbacks pertaining to antibodies such as the high cost of synthesis and large batch-to-batch variation. Aptamers are potential surrogates of antibodies and are much cheaper, without exhibiting batch-to-batch variation. Given these advantages, we sought to isolate RNA aptamers against the NS1 protein of dengue virus serotype 2. A total of 11 cycles of SELEX were carried out, resulting in two potent aptamers, DENV-3 and DENV-6, with dissociation constant values estimated at 37.57 ± 10.34 nM and 41.40 ± 9.29 nM, respectively. These aptamers can be further miniaturized to TDENV-3 and TDENV-6a with an increased LOD upon their usage in direct ELASA. Moreover, these truncated aptamers are highly specific against the dengue NS1 while showing no cross-reactivity against the NS1 of the Zika virus, the E2 protein of the Chikungunya virus or the LipL32 protein of Leptospira, with target selectivity retained even in human serum. The usage of TDENV-3 as the capturing probe and TDENV-6a as the detection probe underpinned the development of an aptamer-based sandwich ELASA for the detection of dengue NS1. The sensitivity of the sandwich ELASA was further improved with the stabilization of the truncated aptamers and the repeated incubation strategy, which enabled a LOD of 2 nM when used with the target NS1 spiked in human serum diluted at 1:2000
How to start with hip arthroscopy in a safe and effective manner, using an evidence-based approach
No full textHip arthroscopy is a rapidly evolving field in orthopedics, offering diagnostic and therapeutic benefits for a range of hip pathologies. This review outlines a comprehensive guide to initiating hip arthroscopy safely and effectively using evidence-based practices. Optimal surgical outcomes depend on correct indications for surgery, in particular in the presence of borderline dysplasia and degenerative joint diseases. Proper patient counseling and setting realistic expectations are crucial for satisfactory outcomes and recovery. Physical examination, radiographs, MRI, and CT scans are essential for accurate diagnosis. In case of diagnostic uncertainty, the use of intra-articular injections can help confirm the diagnosis before surgery. Techniques for hip arthroscopy include central compartment first, peripheral compartment first, and outside-in approaches. Each technique has advantages, and the optimal approach depends on the specific case. Finally, Proper operating room setup, meticulous patient positioning, and precise portal placement are critical for a successful procedure. A thorough understanding of the safe zone anatomy for portal placement is essential to minimize the risk of neurovascular complications. In conclusion, this manuscript provides a detailed, evidence-based framework for starting hip arthroscopy, emphasizing the importance of technical proficiency, patient selection, and a multidisciplinary approach to ensure patient safety and procedure efficacy
Analysis of an alternative topology for steel-concrete-steel sandwich beams incorporating inclined shear connectors
No full textThis thesis presents a new concept in steel-concrete-steel sandwich construction in which a bi-directional corrugated-strip core is proposed as an alternative inclined shear connector. The focus is on the feasibility study of fabrication techniques and the theoretical study of the structural responses of both unfilled and concrete-filled steel-concrete-steel sandwich beams under static flexural loading using numerical and analytical methods. Two possible fabrication techniques to create the proposed bi-directional corrugated strip core are presented. The unfilled sandwich beam is studied using a finite element method and three analytical methods referred to as the modified stiffness matrix, the braced frame analogy, and the discrete beam methods The finite element method is used to investigate the stiffness and strength behaviour of the unfilled sandwich beam.The modified stiffness matrix method provides good correlation with the finite element method. The other two analytical methods are less accurate. The assessment of the effect of geometrical parameters defining the bi-directional corrugated-strip core is carried out. The responses of the strength and stiffness, especially the transverse shear stiffness, are examined and discussed. The optimum configuration of the core is found at the angle of the inclined part of the corrugation is about 45°. The concrete-filled sandwich beam is studied using the finite element method. The finite element method is used to investigate the transverse shear strength and the crack development of a four-point loaded concrete-filled sandwich beam. The assessment of the effect of geometrical parameters defining the inclined shear connectors is carried out. The responses of the concrete-filled sandwich beam are examined and discussed. The optimum advantage of the transverse shear strength of the concrete-filled sandwich beam is also found when the inclined shear connectors align at an angle 45º. It is found that creating the proposed core with a 45° pattern provides a great advantage in transverse shear stiffness and strength in both the unfilled and concrete-filled sandwich beams
