560 results on '"McBride, Andrew"'
Search Results
252. Mapping of peatland conditions in Scotland.
- Author
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Poggio, Laura, Gimona, Alessandro, Bruneau, Patricia, Johnson, Sally, McBride, Andrew, and Artz, Rebekka
- Published
- 2018
253. Preface of the special issue: The joy of mechanics.
- Author
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Runesson, Kenneth, Hossain, Mokarram, and McBride, Andrew
- Subjects
- *
JOY - Published
- 2024
- Full Text
- View/download PDF
254. I Remember [1960 - 2010].
- Author
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Shattuck McBride, Andrew
- Subjects
- I Remember 1960-2010 (Poem), MCBRIDE, Andrew Shattuck
- Abstract
The poem "I Remember [1960-2010]" by Andrew Shattuck McBride is presented. First Line: Other families moved more frequently. Last Line: that forgetfulness arrives, finally.
- Published
- 2015
255. Chuckanut Drive Road Trip.
- Author
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Shattuck McBride, Andrew
- Subjects
- CHUCKANUT Drive Road Trip (Poem), MCBRIDE, Andrew Shattuck
- Abstract
The poem "Chuckanut Drive Road Trip" by Andrew Shattuck McBride is presented. First Line: I drive my elderly friend Evelyn through Fairhaven; Last Line: Evelyn told me.
- Published
- 2015
256. Development of a novel mouse model for the colorectal cancer risk locus at Xp22.2
- Author
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McBride, Andrew Niall
- Subjects
- 616.99, colorectal cancer ; mouse model ; Shroom2 ; GPR143
- Abstract
Colorectal cancer (CRC) is the third most common cancer globally with around 1.3 million cases diagnosed annually. In cases of inherited CRC where none of the rare, high-risk mutations associated with familial syndromes are observed it has been theorised that the heritable risk is due to common, low-risk variants in the genome. Identifying these variants of modest or small effect size has become possible due to the use of large genome-wide association studies (GWAS). Through a meta-analysis of five previous GWAS, Dunlop et al. identified three novel susceptibility loci at 6p21, 11q13.4 and Xp22.2. The aims of this study were to further characterise the Xp22.2 risk locus and investigate the function of the putative risk gene SHROOM2. The variant originally identified in the Dunlop et al. study as showing an association with CRC risk rs5934683 is located between SHROOM2 and GPR143. Genome–wide expression analysis has shown that the variant is an eQTL (expression quantitative locus), affecting expression of SHROOM2, but not GPR143. An important caveat to this analysis was that the commercial array used to measure gene expression does not detect all predicted GPR143 transcripts. Hence it was important to understand whether GPR143 might be involved at the locus and whether there was altered expression in normal colonic mucosa. I have analysed the expression of GPR143 and shown that it is poorly expressed in normal mucosa and that expression of the alternative transcripts is rare. This provided further evidence for the gene of interest at Xp22.2 being SHROOM2 and thus became the focus for further investigation. In order to understand SHROOM2 function a knockout mouse was generated allowing studies of gene function beyond the previously used in vitro systems. Embryonic stem cells containing a Shroom2 knockout first allele were obtained from the International Knockout Mouse Consortium and a novel mouse line established. This mouse line was found to be an incomplete knockout and a Cre recombination strategy was employed to remove the critical exon and create a true null allele for Shroom2. This model was validated as being a true knockout of Shroom2 at both the RNA and protein level and the model subjected to initial phenotyping focusing on tissues where the gene has previously been identified as expressed. To investigate the role of Shroom2 as a CRC susceptibility gene preliminary data has been gathered from crosses to the ApcMin/+ CRC model, and analysis of the intestines of the Shroom2KO line has been undertaken. Two spontaneously occurring anorectal adenomas have been identified in Shroom2 null mice, and an additional mid-colonic polyp phenotype identified when crossed onto the ApcMin/+ background. Additionally, embryonic fibroblasts have been used in growth and wound healing assays to determine what effect total loss of Shroom2 has at a cellular level. Proteomics analysis to identify significantly altered pathways associated with Shroom2 loss has also been carried out and has highlighted a number of interesting targets for further investigation. In summary, a novel Shroom2 knockout mouse model has been developed to investigate the CRC susceptibility locus identified at Xp22.2. Preliminary data from this mouse model appears to confirm SHROOM2 as having a role in tumour development in the large intestine.
- Published
- 2016
257. Access to the medullary canal in closed antegrade femoral nailing: a technical report.
- Author
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Karnezis, Ioannis A. and McBride, Andrew R. T.
- Subjects
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FEMUR injuries , *FEMUR , *INTRAMEDULLARY fracture fixation , *INTERNAL fixation in fractures , *FRACTURE fixation , *TREATMENT of fractures - Abstract
Although general recommendations exist regarding the correct placement of the skin incision and the direction of deep dissection for closed antegrade intramedullary nailing of the femur, in surgical practice simultaneously establishing the correct entry point and exact direction for insertion of the entry instrument in the lateral (sagittal) plane may be difficult. This is due to sub-optimal radiographic images in the lateral plane as a result of the overlying shadows of the pelvis, variations in the degree of rotation of the femur during patient positioning and fracture reduction manoeuvres, variations in the degree of anterior bowing of the femoral shaft and the anatomy of the greater trochanter, and deviations of the plane of deep dissection caused by the glutei muscle fibres. This may lead to the need for several attempts with increased damage to the glutei muscles, high exposure to radiation and the risk of an iatrogenic fracture. The present technical note describes a simple method for swift, easy and accurate access to the medullary canal during closed antegrade femoral nailing. [ABSTRACT FROM AUTHOR]
- Published
- 2003
- Full Text
- View/download PDF
258. INTRAVENOUS INJECTION OF ALCOHOL BY DRUG INJECTORS: REPORT OF THREE CASES.
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Mahdi, Ameera S. and McBride, Andrew J.
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ALCOHOL drinking , *DRUG addiction , *DETOXIFICATION (Substance abuse treatment) , *QUALITATIVE research - Abstract
The article presents several case studies related to alcohol detoxification. A 29-year-old unemployed and homeless man was admitted to a hospital for alcohol and diazepam detoxification. A 29-year-old unemployed man, married with one child was admitted to hospital for alcohol detoxification. A 35-year-old single, unemployed man who lived in a hostel for the homeless was admitted to hospital for alcohol and methadone detoxification and had declared injection of illicit drugs.
- Published
- 1999
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259. Benzodiazepines: time for reassessment.
- Author
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Williams, D. D. R., McBride, Andrew, Williams, D D, and McBride, A
- Subjects
BENZODIAZEPINES ,ANXIETY ,INSOMNIA ,PSYCHOLOGICAL distress ,TRANQUILIZING drugs ,MEDICAL protocols ,ANXIETY disorders - Abstract
The article comments on the development of benzodiapines as a drug used to treat people suffering from anxiety in Great Britain. The drug is recommended to treat insomnia when it is severe, disabling or subjecting the individual to extreme distress. The Committee on the Safety of Medicines released emphatic guidelines about the use of benzodiazepine drugs.
- Published
- 1998
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260. Congress of Crows.
- Author
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MCBRIDE, ANDREW
- Subjects
- CONGRESS of Crows (Poem), MCBRIDE, Andrew
- Abstract
The poem "Congress of Crows" by Andrew McBride is presented. First Line: Where Cornwall Avenue crosses Whatcom; Last Line: of crows, and why shouldn't we care?
- Published
- 2016
261. Can Congress Strip Federal Courts of Jurisdiction Over Foreign Citizens Indefinitely Detained by the United States as Enemy Combatants?: Con.
- Author
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McBride, Andrew G.
- Subjects
- *
CIVIL rights , *LEGAL status of international visitors - Abstract
An excerpt from the Amicus Curiae Brief for the Respondents as submitted to the U.S. Supreme Court on October 9, 2007 regarding the denial of fundamental constitutional rights of foreign detainees at Guantánamo Bay, Cuba is presented.
- Published
- 2008
262. Former Attorneys General, et al., Amici Curiae.
- Author
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McBride, Andrew G.
- Subjects
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ACTIONS & defenses (Law) , *LEGAL briefs - Abstract
An excerpt from the amici curiae brief filed by former attorneys general for the respondents in "Hamdan v. Rumsfeld" submitted to the U.S. Supreme Court on February 23, 2006 is presented.
- Published
- 2006
263. a butterfly's.
- Author
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Shattuck McBride, Andrew
- Abstract
An untitled poem authored by Andrew Shattuck McBride is presented. First Line: a butterfly's; Last Line: my day unpinned.
- Published
- 2014
264. foreclosure.
- Author
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McBride, Andrew Shattuck
- Subjects
GRASS breeding - Abstract
An untitled poem by Andrew Shattuck McBride is presented. First Line: foreclosure; Last Line: I planted.
- Published
- 2015
265. The efficacy of ascorbic acid in the prevention of complex regional pain syndrome (type 1) following distal radial fracture
- Author
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McBride, Andrew Richard Thomson
- Subjects
- 617.15
- Abstract
Complex regional pain syndrome (CRPS) is a common problem presenting to orthopaedic surgeons or pain therapists, most frequently encountered following trauma. The cardinal features are of pain, hypersensitivity, vasomotor instability and joint stiffness. The exact cause remains unproven, however an exaggerated inflammatory response and free radical induced cellular damage has been proposed. A small number of previous studies have highlighted a potential role for antioxidants in the prevention of the condition. Over the last three decades pain researchers have developed and agreed on a set of modified International Association of the Study of Pain (IASP) diagnostic criteria. Orthopaedic researchers have developed their own criteria that have been subject to much debate as to their validity. The diagnosis of CRPS in two hundred and sixty-two patients from a previous study have been reanalysed using the Atkins and modified IASP diagnostic criteria of Bruehl. The incidence of CRPS was similar using either criteria (Bruehl 20.61% vs. Atkins 22.52%). Using the Bruehl criteria as a gold standard, there was strong diagnostic agreement (K = 0.79, sensitivity = 0.87, specificity = 0.94). Two hundred and eleven patients who had sustained an isolated distal radial fracture were recruited for a prospective double-blinded randomised control trial to assess the efficacy of five hundred milligrams of ascorbic acid in order to prevent CRPS. Using an intention to treat analysis one hundred and ninety-six were reviewed at a minimum of nine weeks. There was no significant difference in the incidence of CRPS (chi-squared=1.196, p=0.305) or the incidence or severity of the individual features of the condition between the two treatment groups. The results of this study suggest that prophylaxis with ascorbic acid does not prevent the occurrence of CRPS when diagnosed with validated criteria following a distal radial fracture.
- Published
- 2011
266. Naltrexone implants.
- Author
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Kelly, Kathleen I., McBride, Andrew, Kunøe, Nikolaj, Lobmaier, Philipp, Gessop, Michael, and Waal, Helge
- Subjects
LETTERS to the editor ,NALTREXONE - Abstract
A letter to the editor is presented in response to the article "Naltrexone Implants After In-Patient Treatment for Opioid Dependence: Randomised Controlled Trial," by N. Kunøe and colleagues which appeared in a 2009 issue.
- Published
- 2010
- Full Text
- View/download PDF
267. Needle fixing is not a myth: comments on Al-Adwani's "The myth of needle fixation"
- Author
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Pates, Richard and McBride, Andrew
- Subjects
- *
HYPODERMIC needles , *DRUGS - Abstract
Comments on the myth of needle fixation. Unwillingness of patients to give up injectable drugs; Uses of the injectable drugs; Insufficiency of optimal prescribing treatment and syringe exchanges.
- Published
- 2001
- Full Text
- View/download PDF
268. Searching for novel applications of the benzohomoadamantane scaffold in medicinal chemistry: Synthesis of novel 11β-HSD1 inhibitors.
- Author
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Valverde, Elena, Seira, Constantí, McBride, Andrew, Binnie, Margaret, Luque, F. Javier, Webster, Scott P., Bidon-Chanal, Axel, and Vázquez, Santiago
- Subjects
- *
INTERFERON inducers , *MOLECULAR structure , *ADAMANTANE , *PHARMACEUTICAL chemistry , *CYCLOALKANES , *MATERIA medica , *HYDROXYSTEROID dehydrogenases - Abstract
The structural and physicochemical properties of the adamantane nucleus account for its use as a chemical scaffold in multiple drugs. In the last years, we have developed new polycyclic scaffolds as surrogates of the adamantane group with encouraging results in multiple targets. As adamantane is a common structural feature in several 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) inhibitors, we have explored the ability of the 6,7,8,9,10,11-hexahydro-5 H -5,9:7,11-dimethanobenzo[9]annulen-7-yl scaffold to act as a surrogate of the adamantane nucleus in a novel series of 11β-HSD1 inhibitors. Of note, within this family of compounds one derivative is endowed with submicromolar 11β-HSD1 inhibitory activity. Molecular modeling studies support the binding of the compounds to the active site of the enzyme. However, a fine tuning of the hydrophobicity of the size-expanded nucleus may be beneficial for the inhibitory potency. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
269. Today.
- Author
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McBRIDE, ANDREW SHATTUCK
- Subjects
- TODAY (Poem), MCBRIDE, Andrew Shattuck
- Abstract
The poem "Today" by Andrew Shattuck McBride is presented. First Line: Today I don't want to write about the older woman; Last Line: individual humans. Today this is what makes me smile.
- Published
- 2013
270. Letter. A comparison of home detoxification and minimal intervention strategies for problem drinkers.
- Author
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LEWIS, JULIA C. and McBRIDE, ANDREW J.
- Subjects
- *
LETTERS to the editor , *ALCOHOLISM treatment - Abstract
A letter to the editor is presented in response to the article "A comparison of home detoxification and minimal intervention strategies for problem drinkers," by C. Bennie in the 1998 issue.
- Published
- 1999
- Full Text
- View/download PDF
271. Cannabis use in a drug and alcohol clinic population
- Author
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McBride, Andrew J.
- Published
- 1995
- Full Text
- View/download PDF
272. A Hybrid voice/text electronic mail system: an application of the integrated services digital network
- Author
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McBride, Andrew
- Subjects
- Integrated services digital network, Local area network, Phone terminal
- Abstract
The objective of this thesis is to present a useful application for the Integrated Services Digital Network (ISDN) that is expected to one day replace the analog phone system in use today. ISDN itself and its continuing evolution are detailed. The system developed as a part of this thesis involved the creation of an inexpensive "phone terminal" that can serve as an ISDN terminal and also as a bridge to a Local Area Network (LAN). The "phone terminal" provides a hybrid electronic mail system that allows the attachment of speech to text within a message. Messages created with this "phone terminal" could theoretically be sent locally using the LAN interface and globally using ISDN to other users with either "phone terminals" or multimedia personal computers. For this project, the two "phone terminals" created were interconnected via an Ethernet and using an 80486 PC to act as a Central Office System. This Central Office System provides speech/message storage for the "phone terminals." It makes use of speech compression techniques to minimize the storage requirements. The speech compression techniques used as well as the field of speech coding in general are discussed.
- Published
- 1994
273. Psychosis is also common in users of "normal" cannabis.
- Author
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McBride, Andrew J. and Thomas, Huw
- Published
- 1995
- Full Text
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274. Unilateral auditory hallucinations.
- Author
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McBride, Andrew and Hamilton-Kirkwood, Lawrence
- Subjects
LETTERS to the editor ,AUDITORY hallucinations - Abstract
A letter to the editor is presented that presents cases of auditory hallucinations in schizophrenic patients.
- Published
- 1988
275. Metastatic Tumor Volume and Extranodal Tumor Extension.
- Author
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Drinka, Eva, Allen, Pamela, McBride, Andrew, Buchholz, Thomas, and Sahin, Aysegul
- Subjects
- *
BREAST tumors , *CANCER invasiveness , *CONFIDENCE intervals , *FISHER exact test , *LYMPH nodes , *MULTIVARIATE analysis , *PROBABILITY theory , *PROGNOSIS , *SURVIVAL analysis (Biometry) , *SURVIVAL , *TIME , *PROPORTIONAL hazards models , *RETROSPECTIVE studies , *SEVERITY of illness index , *DATA analysis software , *DESCRIPTIVE statistics , *KAPLAN-Meier estimator , *LOG-rank test - Abstract
Context.--Lymph node status and the number of lymph node (LN) positive for cancer cells are the most important prognostic factors in breast cancer. Extranodal tumor extension (ENTE) has been used as a histopathologic feature to classify patients into high risk versus low risk for local recurrence. However, in the current era of early detection and systemic therapy, the prognostic significance of ENTE is not as well defined in patients with 1 to 3 LNs positive for cancer. Objective.--To determine whether the amount of tumor burden in an axillary dissection or the presence of ENTE provides any additional information regarding patient outcome in patents with 1 to 3 positive LN results. Design.--Clinical and pathologic factors were identified for 456 patients with breast cancer at the University of Texas MD Anderson Cancer Center, Houston, who had pT1 tumors and 1 to 3 LNs positive for cancer and were treated by mastectomy, with or without postmastectomy radiotherapy, between 1978 and 2007. Results.--Of the 456 patients, 257 (56.4%), 141 (31.6%), and 58 (12.7%) patients had 1, 2, or 3 positive LN results, respectively. Extranodal tumor extension was present in 99 patients (21.7%) and was absent in the remaining 357 cases (78.3%). Seventy-six patients (16.7%) received radiation therapy. Patients had both worse overall survival time and disease-free survival when ENTE was present, regardless of the amount, as long as the treatment era was not included in the multivariate analysis (pre-2000 versus post-2000). However, ENTE was no longer significant on multivariate analysis when the year of treatment was taken into account. Conclusions.--The number of positive LNs remains an important predictor of survival in patients with 1 to 3 positive LN results, but the prognostic significance of ENTE in this cohort of patients has diminished over time. [ABSTRACT FROM AUTHOR]
- Published
- 2015
- Full Text
- View/download PDF
276. Quantifying the effect of macrozones on the cold-dwell fatigue response of UD-rolled Ti-6Al-4V using high-energy X-ray diffraction.
- Author
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Triantafyllou, Christos, Pagan, Darren C., and McBride, Andrew
- Subjects
- *
X-ray diffraction , *DIGITAL image correlation , *CYCLIC loads - Abstract
High-energy X-ray diffraction is used to investigate the evolution of elastic lattice strains in rolled Ti-6Al-4V specimens during cyclic loading in-situ with and without the inclusion of a 120 s dwell period. A 1 mm segment of the gauge section is monitored throughout the first 100 cycles for specimens extracted along the rolling direction (RD), the transverse direction (TD) and 45° between the two, to explore the effects of texture on the evolution of the micromechanical response. Five families of lattice planes from the hexagonal α phase are analysed with emphasis on lattice strain measured at the peak of each cycle, while macroscopic strain accumulation is simultaneously monitored via Digital Image Correlation. In cyclic loading conditions including a dwell period at load, a prominent increase in elastic strains is observed in prismatic and basal lattice planes with the specimen loaded 45° from the rolling direction. In the absence of dwell, both RD and TD specimen orientations exhibited subtle cyclic hardening in all families of lattice planes probed despite negligible evolution in accumulated macroscopic plastic strain. Estimations of lattice orientation-dependent stresses are also presented using directional moduli to examine redistribution of load across sets of grains with the increasing cycle count. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
277. Well-posedness of a model of strain gradient plasticity for plastically irrotational materials
- Author
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Reddy, B. Daya, Ebobisse, François, and McBride, Andrew
- Subjects
- *
DEFORMATIONS (Mechanics) , *RHEOLOGY , *MICROMECHANICS , *STEREOLOGY - Abstract
Abstract: The initial boundary value problem corresponding to a model of strain gradient plasticity due to [Gurtin, M., Anand, L., 2005. A theory of strain gradient plasticity for isotropic, plastically irrotational materials. Part I: Small deformations. J. Mech. Phys. Solids 53, 1624–1649] is formulated as a variational inequality, and analysed. The formulation is a primal one, in that the unknown variables are the displacement, plastic strain, and the hardening parameter. The focus of the analysis is on those properties of the problem that would ensure existence of a unique solution. It is shown that this is the case when hardening takes place. A similar property does not hold for the case of softening. The model is therefore extended by adding to it terms involving the divergence of plastic strain. For this extended model the desired property of coercivity holds, albeit only on the boundary of the set of admissible functions. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
278. We'll Rue Having Judges on the Battlefield.
- Author
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McBride, Andrew
- Subjects
- *
LEGAL judgments , *ACTIONS & defenses (Law) , *BOUMEDIENE v. Bush , *NATIONAL security - Abstract
The author offers his opinion about the decision of the U.S. Supreme Court on the case Boumediene versus Bush, which has been hailed as a victory for civil rights and the rule of law. He notes that the court has rejected the considered judgment of the Congress and the president on an issue of national security. He argues that the judicial branch should not check the political branches particularly in an effort to fight an enemy. He claims that the judiciary is not competent to make judgments on determining an enemy combatant.
- Published
- 2008
279. Billy.
- Author
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McBride, Andrew
- Subjects
BIOGRAPHIES ,NONFICTION - Abstract
Reviews the book "Billy," by Pamela Stephenson.
- Published
- 2004
- Full Text
- View/download PDF
280. Multifield finite strain plasticity: Theory and numerics.
- Author
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Lewandowski, Karol, Barbera, Daniele, Blackwell, Paul, Roohi, Amir H., Athanasiadis, Ignatios, McBride, Andrew, Steinmann, Paul, Pearce, Chris, and Kaczmarczyk, Łukasz
- Subjects
- *
LINEAR momentum , *DEGREES of freedom , *SOLID mechanics , *SCIENTIFIC computing , *FINITE element method - Abstract
Motivated by the inability of classical computational plasticity to fully exploit modern scientific computing, a multifield formulation for finite strain plasticity is presented. This avoids a local integration of the elastoplastic model. In the multifield approach, the balance of linear momentum, the flow relation and the Karush–Kuhn–Tucker constraints are collectively cast in a variational format. In addition to the deformation, both the plastic strain and the consistency parameter are global degrees of freedom in the resulting spatially discrete problem. The ensuing proliferation of global degrees of freedom in the multifield approach is addressed by exploiting the block sparse structure of the algebraic system together with a tailored block matrix solver which can utilise emerging hardware architectures. A series of numerical problems demonstrate the validity, capability and efficiency of the proposed approach. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
281. Numerical simulation of friction welding processes: An arbitrary Lagrangian-Eulerian approach
- Author
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Hamed, Maien Mohamed Osman, Reddy, Daya, and McBride, Andrew
- Subjects
Mechanical Engineering - Abstract
The development and implementation of a finite strain thermo-viscoplasticity solver with thermomechanical friction contact for numerical simulation of friction welding processes are described. A finite strain associative coupled thermoplasticity model is used, which is suited for the large deformations characteristic of friction welding processes, and which resolves the viscoplastic deformations in the thermomechanically affected zone as well as the elastic stresses in the parent material. To prevent the large deformations from causing large distortions and degrading the simulation accuracy, an arbitrary Lagrangian Eulerian (ALE) formulation for coupled finite strain thermoplasticity is developed and incorporated into the solver, in which the motion of the reference configuration is represented incrementally in terms of a reference velocity field. Thus, the deformation from the material configuration is required neither explicitly in terms of a deformation field, nor implicitly in terms of the deformation gradient. The solver is implemented using the deal. II library and programmed for distributed memory parallel computing architectures, which reduces simulation run times and enables simulations with larger meshes than would fit on a single computer. The interprocess communications required in such a distributed memory parallel implementation of the ALE formulation and the thermomechanical friction contact are described and implemented. The axisymmetric solver implementation is validated with benchmark problems and used to simulate a direct drive friction welding process.
- Published
- 2022
282. Design, synthesis and in vivo study of novel pyrrolidine-based 11β-HSD1 inhibitors for age-related cognitive dysfunction.
- Author
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Leiva, Rosana, Griñan-Ferré, Christian, Seira, Constantí, Valverde, Elena, McBride, Andrew, Binnie, Margaret, Pérez, Belén, Luque, F. Javier, Pallàs, Mercè, Bidon-Chanal, Axel, Webster, Scott P., and Vázquez, Santiago
- Subjects
- *
COGNITION disorders , *PYRROLIDINE , *NEUROPROTECTIVE agents , *LABORATORY mice , *IN vivo studies ,AGE factors in Alzheimer's disease - Abstract
Recent findings suggest that treatment with 11β-HSD1 inhibitors provides a novel approach to deal with age-related cognitive dysfunctions, including Alzheimer's disease. In this work we report potent 11β-HSD1 inhibitors featuring unexplored pyrrolidine-based polycyclic substituents. A selected candidate administered to 12-month-old SAMP8 mice for four weeks prevented memory deficits and displayed a neuroprotective action. This is the first time that 11β-HSD1 inhibitors have been studied in this broadly-used mouse model of accelerated senescence and late-onset Alzheimer's disease. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
283. The discovery of potent and selective kynurenine 3-monooxygenase inhibitors for the treatment of acute pancreatitis.
- Author
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Liddle, John, Beaufils, Benjamin, Binnie, Margaret, Bouillot, Anne, Denis, Alexis A., Hann, Michael M., Haslam, Carl P., Holmes, Duncan S., Hutchinson, Jon P., Kranz, Michael, McBride, Andrew, Mirguet, Olivier, Mole, Damian J., Mowat, Christopher G., Pal, Sandeep, Rowland, Paul, Trottet, Lionel, Uings, Iain J., Walker, Ann L., and Webster, Scott P.
- Subjects
- *
PANCREATITIS treatment , *CHEMICAL inhibitors , *KYNURENINE , *MONOOXYGENASES , *PHARMACODYNAMICS - Abstract
A series of potent, competitive and highly selective kynurenine monooxygenase inhibitors have been discovered via a substrate-based approach for the treatment of acute pancreatitis. The lead compound demonstrated good cellular potency and clear pharmacodynamic activity in vivo . [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
284. Noninvasive Detection of Early Metabolic Left Ventricular Remodeling in Systemic Hypertension.
- Author
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Hamirani, Yasmin S., Kundu, Bijoy K., Zhong, Min, McBride, andrew, Li, Yinlin, Davogustto, Giovanni E., Taegtmeyer, Heinrich, and Bourque, Jamieson M.
- Subjects
- *
POSITRON emission tomography , *LEFT ventricular hypertrophy , *ECHOCARDIOGRAPHY , *HYPERTENSION , *GLUCOSE metabolism - Abstract
Objectives: Hypertension (HTN) is a common cause of left ventricular hypertrophy (LVH). Sustained pressure overload induces a permanent myocardial switch from fatty-acid to glucose metabolism. In this study, we tested the hypothesis that metabolic remodeling, characterized by increased myocardial glucose uptake, precedes structural and functional remodeling in HTN-induced LVH. Methods: We recruited 31 patients: 11 with HTN only, 9 with HTN and LVH and 11 normotensive controls without LVH. Transthoracic echocardiography was performed to assess the function, mass, wall thickness and diastolic function of the left ventricle. Positron emission tomography imaging was performed, and the rate of myocardial 2-deoxy-2-[18F]fluoro-D-glucose uptake, Ki, was determined using a 3-compartment kinetic model. Results: The mean Ki values were significantly higher in HTN patients than in those with HTN and LVH (p < 0.001) and in controls (p = 0.003). The unexpected decrease in Ki with LVH may be secondary to a decreased Ki with diastolic dysfunction (DD), 0.039 ± 0.032 versus 0.072 ± 0.013 (p = 0.004). There was also a significant stepwise decrease in Ki with increasing DD grade (p = 0.04). Conclusion: Glucose metabolic remodeling is detectable in hypertensive patients before the development of LVH. Furthermore, lower glucose uptake rates are observed in patients with DD. The mechanism for this last finding requires further investigation. © 2015 S. Karger AG, Basel [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
285. A variational integrator for the Discrete Element Method.
- Author
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De Klerk, David N., Shire, Thomas, Gao, Zhiwei, McBride, Andrew T., Pearce, Christopher J., and Steinmann, Paul
- Subjects
- *
DISCRETE element method , *STATISTICAL ensembles , *INTEGRATORS , *GRANULAR materials - Abstract
A novel implicit integration scheme for the Discrete Element Method (DEM) based on the variational integrator approach is presented. The numerical solver provides a fully dynamical description that, notably, reduces to an energy minimisation scheme in the quasi-static limit. A detailed derivation of the numerical method is presented for the Hookean contact model and tested against an established open source DEM package that uses the velocity-Verlet integration scheme. These tests compare results for a single collision, long-term stability and statistical quantities of ensembles of particles. Numerically, the proposed integration method demonstrates equivalent accuracy to the velocity-Verlet method. • An implicit integration scheme for the Discrete Element Method based on the variational integrator approach is presented. • Numerically, the proposed integration method demonstrates equivalent accuracy to the established methods. • This work is inspired by the Quasicontinuum Method and is seen as a crucial step towards a granular Quasicontinuum Method. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
286. Genetic and environmental influences on the relationship between peer alcohol use and own alcohol use in adolescents.
- Author
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Fowler, Tom, Shelton, Katherine, Lifford, Kate, Rice, Frances, McBride, Andrew, Nikolov, Ivan, Neale, Michael C., Harold, Gordon, Thapar, Anita, and Van Den Bree, Marianne B. M.
- Subjects
- *
ALCOHOL drinking , *HUMAN behavior , *PEER relations , *BEST friends , *ALCOHOLISM , *DRINKING behavior , *SUBSTANCE abuse , *GENETICS , *TEENAGERS - Abstract
Aims Genetically influenced aspects of adolescent behaviour can play a role in alcohol use and peer affiliation. We explored the correlations between friends' alcohol use and adolescent own use with a genetically sensitive design. Design Genetic and environmental factors were estimated on adolescent reports of their friends' alcohol use and their own use and problem use of alcohol. The correlations between the genetic and environmental factors that influence friends' alcohol use and adolescent own alcohol use and problem use were also estimated. Participants A total of 862 twin pairs aged 11–17 years sampled from the UK population-based Cardiff Study of All Wales and North-west of England Twins (CaStANET). Measurements Data on adolescent own alcohol use and problem use and the alcohol use of their three best friends were obtained using self-report questionnaires. Findings A significant genetic influence was found on adolescent friends' alcohol use (about 30%). Significant correlations of 0.60 and 0.70 were found between the genetic influences on friends' alcohol use and adolescents' own use and problem use of alcohol. Common environmental influences were almost completely correlated for friends' alcohol use and adolescents' own alcohol use and problem use (0.91 and 0.94). Conclusions There is considerable overlap in the common environmental and genetic factors that contribute to the relationship between adolescents' own alcohol use and that of their friends. These findings contribute to understanding of the mechanisms by which friends' alcohol use influences adolescent drinking behaviour. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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287. Exploring the relationship between genetic and environmental influences on initiation and progression of substance use.
- Author
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Fowler, Tom, Lifford, Kate, Shelton, Katherine, Rice, Frances, Thapar, Anita, Neale, Michael C., McBride, Andrew, and Van Den Bree, Marianne B. M.
- Subjects
- *
HUMAN genetics , *SUBSTANCE abuse , *ALCOHOLISM , *SMOKING , *MARIJUANA abuse , *ADOLESCENCE , *TEENAGERS , *YOUNG adults , *SOCIAL context , *SOCIOLOGY - Abstract
Aims To examine the genetic and environmental contributions to the initiation of use and progression to more serious use of alcohol, cigarettes and marijuana during adolescence, and to examine the relationship between initiation and progression of substance use. Design The study used a twin-based design and a new theoretical model, the causal–common–contingent (CCC) model. This allows modelling of the relationship between initiation of use and progression to heavier use as a two-stage model and the examination of genetic and environmental influences on both stages, while taking into account their relationship. Participants The participants consisted of 1214 twin pairs (69% response rate) aged 11–19 years sampled from the UK population-based Cardiff Study of All Wales and North-west of England Twins (CaStANET). Measurements Data on adolescent initiation and progression to more serious use of alcohol, cigarettes and marijuana were obtained using self-report questionnaires. Findings Initiation of alcohol and progression to heavier alcohol use had separate but related underlying aetiologies. For cigarette and marijuana use the relation between initiation and progression to heavier use was stronger, suggesting greater overlap in aetiologies. For all three substances, environmental influences that make twins more similar (common environment) tended to be greater for initiation, while genetic influences were stronger for heavier use. Conclusions These findings have implications for policy decisions aimed at an adolescent and early adult age group. Specifically, these findings suggest that it may be more efficacious to focus alcohol interventions on risk factors for the development of heavier use rather than initiation of use. In contrast, interventions aimed at reducing the initiation of cigarettes and marijuana use may be more appropriate. [ABSTRACT FROM AUTHOR]
- Published
- 2007
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288. Dense granular flow in rotating drums: a computational investigation of constitutive equations
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Povall, Timothy Mark, Govender, Indresan, McBride, Andrew, and Reddy, B Daya
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Physics - Abstract
The constitutive laws of dense granular flow are investigated. Simulations of a drum, with periodic boundary conditions, rotating at varying speeds are performed. From the resulting data, kinematic and kinetic fields are extracted and used to investigate the validity of constitutive relations proposed in the literature. Two key constitutive assumptions are (a) isotropy and (b) incompressibility. The rotating drum system is found to be largely isotropic for high rotational speeds. For low rotational speeds, anisotropy is observed in the bottom part of the system, where the particles are flowing upwards. A small degree of compressibility is observed in the downward-flowing layer. The friction coefficient for the granular constitutive relations is also investigated. An empirically-derived friction law has a better fit to the data when compared to other friction laws proposed in the literature. Lastly, two scaling laws are investigated: the scaling between the scaled flow-rate (flux) and the thickness of the downward- flowing layer and the scaling between the dynamic angle of repose of the bed and the flux through the downward- flowing layer. The thickness-flux scaling is measured by interpolating the flux over a number of slices through the flowing layer, this is done in a number of different ways. The size of the measured section through the flowing layer is varied. The orientation of the slices is also varied. Also investigated is whether the total velocity or the tangential velocity produce the same scaling. The size of the section of the flowing layer significantly changes the scaling, this shows that the scaling is not constant throughout the flowing layer. The dynamic angle of repose is determined using two methods, one which is determined unambiguously as the repose angle of the ellipse fitted to the equilibrium surface and the other which is the changing angle of the tangent to the equilibrium surface or free surface. The first repose angle is found to be highly dependent on the flux even in the limit of infinite drum length, which is modelled using axial periodic boundary conditions. The second definition results in two sets of repose angles with complex behaviour that may be due to inertial effects. An instability in the system is observed, this is conjectured to be due to a frictional threshold that is breached as the rotational speed of the drum increases. Algorithms for calculating field variables and features of the charge are presented.
- Published
- 2018
289. Constitutive modelling of the skin accounting for chronological ageing
- Author
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Pond, Damien and McBride, Andrew Trevor
- Subjects
integumentary system ,Mechanical Engineering ,Biomechanical Engineering - Abstract
The skin is the largest organ in the human body. It is the first line of contact with the outside world, being subject to a harsh array of physical loads and environmental factors. In addition to this, the skin performs numerous physiological tasks such as thermo-regualtion, vitamin D synthesis and neurotransduction. The skin, as with all biological tissue, is subject to chronological ageing, whereby there is a general breakdown of tissue function and a decline in mechanical properties. In addition to this, skin undergoes extrinsic forms of ageing through exposure to external factors such as ultraviolet radiation, air pollution and cigarette smoking. Skin modelling is an area of biomechanics that, although medical in nature, has expanded into areas such as cosmetics, military, sports equipment and computer graphics. Skin can be approximated at the macroscopic continuum scale as an anisotropic, nearly-incompressible, viscoelastic and non-linear material whose material properties are highly dependent on the ageing process. Through the literature, several phenomenologically based models have been satisfactorily employed to capture the behaviour inherent to the skin, but despite the intrinsic link to age, to date no constitutive model for the UV-induced ageing/damage of skin has been developed that is both capable of capturing the material and structural effects, and is embedded in the rigorous framework of non-linear continuum mechanics. Such a mechanistic model is proposed here. The macroscopic response of the skin is due to microscopic components such as collagen, elastin and the surrounding ground substance and the interaction between them. An overview on the structure of the skin helps motivate the form of the continuum model and identifies which aspects of the skin need to be captured in order to replicate the macroscopic response. Furthermore, the ageing process is explored and a firm understanding of the influence of ageing on the substructures is established. Over time, elastin levels tend to decrease which results in a loss of skin elasticity. Collagen levels drop with age, but tend to flatten out which results in an overall increase in skin stiffness and loss of anisotropy. A worm-like chain constitutive model, arranged in an 8-chain configuration, is employed to capture the mechanical response of the skin. The use of such a micro-structurally-motivated model attempts to connect the underlying substructures (collagen, elastin and ground substance) present in the skin to the overall mechanical response. The constitutive model is implemented within a finite element scheme. Simple uniaxial tests are employed to ascertain the validity of the model, whereby skin samples are stretched to elicit the typical anisotropic locking response. A more complex loading condition is applied through bulge tests where a pressure is applied to an in vitro skin specimen. This more complex test is subsequently used to conduct a series of ageing numerical experiments to ascertain the response of the model to changes in material properties associated with ageing. A modified model is then proposed to capture the ageing response of the skin. The key microscopic biophysical processes that underpin ageing are identified, approximated and adapted sufficiently to be of use in the macroscopic continuum model. Aspects of open-system thermodynamics and mixture theory are adapted to the context of ageing in order to capture a continuous ageing response.
- Published
- 2017
290. A patient-specific FSI model for vascular access in haemodialysis
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De Villiers, Anna Magdalena, Reddy, B Daya, and McBride, Andrew Trevor
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Vascular Mechanics ,Haemodynamics - Abstract
This research forms part of an interdisciplinary project that aims to improve the understanding of haemodynamics and vascular mechanics in arteriovenous shunting. To achieve the high flow rates that enable patients with renal disease to receive haemodialysis, a fistula is created between an artery and a vein. The patency rate of fistulas, especially those located in the upper arm, is low. The approach adopted here makes use of new magnetic resonance image (MRI) technology and computational modelling of blood flow, with a view to improving therapeutic strategies of disease requiring vascular interventions. This thesis presents the construction and development of a 3D finite element model of the fluid-structure interaction in a brachial–cephalic patient–specific fistula. An overview of the mathematical models that describe the vessel wall and fluid behaviour as well their interaction with each other is given. An Arbitrary Lagrangian- Eulerian (ALE) framework is used together with a transversely isotropic hyperelastic constitutive model for the vessel walls, while blood flow is modelled as a Newtonian fluid. A three-element Windkessel model is used to allow the fluid to move through the outlets of the computational domain without causing non–physical reflections. Flow data acquired from MRI is used to prescribe the flow at the inlet. The parameters of the Windkessel-model at the two outlets are calibrated to resemble the flow acquired from the 2D MRI. The model is validated against the flow patterns acquired from the 4D MRI. The flow patterns of the blood, and stress present in the vessel are investigated. Of special significance are the flow and wall shear stress at the anastomosis. An area of very high velocity in the anastomosis is followed by an area of recirculation and low velocity. The propagation of pressure waves and their reflection at the anastomosis are studied. Areas that are subjected to low wall shear stress, high oscillatory wall shear stress or flow circulation are identified as areas where intimal hyperplasia may develop. The flow results from the simulation show good qualitative agreement with the MRI data.
- Published
- 2017
291. Stable algorithms for generalized thermoelasticity based on operator-splitting and time-discontinuous Galerkin finite element methods
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Wakeni, Mebratu Fenta, Reddy, B Daya, and McBride, Andrew Trevor
- Subjects
Applied Mathematics - Abstract
This thesis deals with the theoretical and numerical analysis of coupled problems in thermoelasticity. Of particular interest are models that support propagation of thermal energy as waves, rather than the usual mechanism by diffusion. The thesis consists of two parts. The first deals with the non-classical, linear thermoelastic model first proposed and developed by Green and Naghdi in the years between 1991 and 1995, as a possible alternative that potentially removes the shortcomings of the standard Fourier based model. The non-classical theory incorporates three models: the classical model based on Fourier's law of heat conduction, resulting in a hyperbolic-parabolic coupled system; a non-classical theory of a fully-hyperbolic extension; and a combination of the two. An efficient staggered time-stepping algorithm is proposed based on operator-splitting and the time-discontinuous Galerkin finite element method for the non-classical, linear thermoelastic model. The coupled problem is split into two contractive sub-problems, namely, the mechanical phase and thermal phase, on the basis of an entropy controlling mechanism. In the mechanical phase temperature is allowed to vary so as to ensure the entropy remains constant, while the thermal phase is a purely non-classical heat conduction problem in a fixed configuration. Each sub-problem is discretized using the time-discontinuous Galerkin finite element method, resulting in stable time-stepping sub-algorithms. A global stable algorithm is obtained by combining the algorithms for the sub-problems by way of a product method. A number of numerical examples are presented to demonstrate the performance and capability of the method. The second part of this work concerns the formulation of a thermodynamically consistent generalized model of nonlinear thermoelasticity, whose linearization about a natural reference configuration includes the theory of Green and Naghdi. The generalized model is based on the fundamental laws of continuum mechanics and thermodynamics, and is realized through two basic assumptions: The first is the inclusion into the state space of a vector field, which is known as the thermal displacement, and is a time primitive of the absolute temperature. The second is that the heat flux vector is additively split into two parts, which are referred to as the energetic and dissipative components of the heat flux vector. The application of the Coleman-Noll procedure leads to find constitutive relations for the stress, entropy, and energetic component of the heat flux as derivatives of the free energy function. Furthermore, a Clausius-Duhem-type inequality is assumed on a constitutive relation for the dissipative component of the heat flux vector to ensure thermodynamic consistency. A Lyapunov function is obtained for the generalized problem with finite strains; this serves as the basis for the stability analysis of the numerical methods designed for generalized thermoelasticity at finite strains. Due to the lack of convexity of the elastic potential in the finite strain case, a direct extension of the time-discontinuous formulation from the linear to the finite strain case does not guarantee stability. For this reason, various numerical formulations both in monolithic and staggered approaches with fully or partially time-discontinuity assumptions are presented in the framework of the space-time methods. The stability of each of the numerical algorithms is thoroughly analysed. The capability of the newly formulated generalized model of thermoelasticity in predicting various expected features of non-Fourier response is illustrated by a number of numerical examples. These also serve to demonstrate the performance of the space-time Galerkin method in capturing fine solution features.
- Published
- 2016
292. Multiple particle tracking in PEPT using Voronoi tessellations
- Author
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Blakemore, Dylan, Govender, Indresan, and McBride, Andrew Trevor
- Subjects
Mechanical Engineering - Abstract
An algorithm is presented which makes use of three-dimensional Voronoi tessellations to track up to 20 tracers using a PET scanner. The lines of response generated by the PET scanner are discretized into sets of equidistant points, and these are used as the input seeds to the Voronoi tessellation. For each line of response, the point with the smallest Voronoi region is located; this point is assumed to be the origin of the corresponding line of response. Once these origin points have been determined, any outliers are removed, and the remaining points are clustered using the DBSCAN algorithm. The centroid of each cluster is classified as a tracer location. Once the tracer locations are determined for each time frame in the experimental data set, a custom multiple target tracking algorithm is used to associate identical tracers from frame to frame. Since there are no physical properties to distinguish the tracers from one another, the tracking algorithm uses velocity and position to extrapolate the locations of existing tracers and match the next frame's tracers to the trajectories. A series of experiments were conducted in order to test the robustness, accuracy and computational performance of the algorithm. A measure of robustness is the chance of track loss, which occurs when the algorithm fails to match a tracer location with its trajectory, and the track is terminated. The chance of track loss increases with the number of tracers; the acceleration of the tracers; the time interval between successive frames; and the proximity of tracers to each other. In the case of two tracers colliding, the two tracks merge for a short period of time, before separating and become distinguishable again. Track loss also occurs when a tracer leaves the field of view of the scanner; on return it is treated as a new object. The accuracy of location of the algorithm was found to be slightly affected by tracer velocity, but is much more dependent on the distance between consecutive points on a line of response, and the number of lines of response used per time frame. A single tracer was located to within 1.26mm. This was compared to the widely accepted Birmingham algorithm, which located the same tracer to within 0.92mm. Precisions of between 1.5 and 2.0mm were easily achieved for multiple tracers. The memory usage and processing time of the algorithm are dependent on the number of tracers used in the experiment. It was found that the processing time per frame for 20 tracers was about 15s, and the memory usage was 400MB. Because of the high processing times, the algorithm as is is not feasible for practical use. However, the location phase of the algorithm is massively parallel, so the code can be adapted to significantly increase the efficiency.
- Published
- 2016
293. Fluid-structure interaction modelling of a patient-specific arteriovenous access fistula
- Author
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Guess, Winston, Reddy, B Daya, and McBride, Andrew Trevor
- Subjects
Mechanical Engineering - Abstract
This research forms part of an interdisciplinary project that aims to improve the detailed understanding of the haemodynamics and vascular mechanics in arteriovenous shunts that are required for haemodialysis treatments. A combination of new PCMRA imaging and computational modelling of in vivo blood flow aims to determine the haemodynamic conditions that may lead to the high failure rate of vascular access in these circumstances. This thesis focuses on developing a patient-specific fluid-structure interaction (FSI) model of a PC-MRA imaged arteriovenous fistula. The numerical FSI model is developed and simulated within the commercial multiphysics simulation package ANSYS® Academic Research, Release 16. The blood flow is modelled as a Newtonian fluid with the finite-volume method solver ANSYS® Fluent®. A pulsatile mass-flow boundary condition is applied at the artery inlet and a three-element Windkessel model at the artery and vein outlets. ANSYS® Mechanical™, a finite element method solver, is used to model the nonlinear behaviour of the vessel walls. The artery and vein walls are assumed to follow a third-order Yeoh model, and are differentiated by thickness and by material strength characteristics. The staggered FSI model is configured and executed in ANSYS® Workbench™, forming a semi-implicit coupling of the blood flow and vessel wall models. This work shows the effectiveness of combining a number of stabilisation techniques to simultaneously overcome the added-mass effect and optimise the efficiency of the overall model. The PC-MRA data, fluid model, and FSI model show almost identical flow features in the fistula; this applies in particular to a flow recirculation region in the vein that could potentially lead to fistula failure.
- Published
- 2016
294. A novel micromorphic approach captures non-locality in continuum bone remodelling.
- Author
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Titlbach A, Papastavrou A, McBride A, and Steinmann P
- Subjects
- Humans, Bone Density, Femur physiology, Femur diagnostic imaging, Femur anatomy & histology, Models, Biological, Finite Element Analysis, Bone Remodeling physiology
- Abstract
In continuum bone remodelling, bone is considered as continuous matter on the macroscale. Motivated by i) the underlying trabecular microstructure of bone resulting in size-dependence and ii) the non-local characteristics of osteocyte mechanosensing, a novel phenomenological approach based on a micromorphic formulation is proposed. Via illustrative benchmark examples, i.e. elementary unit cube, rod-shaped bone samples, and a 3D-femur sample, the novel approach is compared to the established local formulation, and the influence of the characteristic size of the microcontinuum and the coupling between macro- and microscale deformation is analysed. Taken together, the interaction between continuum points at the macroscale and their neighbourhood is effectively captured by the micromorphic formulation thus influencing the resulting distribution of nominal bone density at the macroscale.
- Published
- 2024
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295. Authorship agreements benefit researchers and research culture.
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Rasmussen LM, Banks G, Demeter E, Holladay-Sandidge HD, McBride A, Hall-Hertel K, and Tonidandel S
- Subjects
- Humans, Publishing, Research Personnel, Authorship, Biomedical Research
- Published
- 2023
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296. Survivorship of shoulder arthroplasty in young patients with osteoarthritis: an analysis of the Australian Orthopaedic Association National Joint Replacement Registry.
- Author
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Khoriati AA, McBride AP, Ross M, Duke P, Hoy G, Page R, Holder C, and Taylor F
- Subjects
- Humans, Survivorship, Treatment Outcome, Retrospective Studies, Australia, Reoperation, Registries, Arthroplasty, Replacement, Shoulder adverse effects, Shoulder Joint surgery, Orthopedics, Osteoarthritis, Arthroplasty, Replacement, Joint Dislocations surgery
- Abstract
Background: The treatment of shoulder osteoarthritis in the young patient remains challenging. The higher functional demands and higher expectations of the young patient cohort are often coupled with increased failure and revision rates. Consequently, shoulder surgeons are faced with a unique challenge with implant selection. The aim of this study was to compare the survivorship and reasons for revision of 5 classes of shoulder arthroplasty in patients aged <55 years with a primary diagnosis of osteoarthritis by use of data from a large national arthroplasty registry., Methods: The study population included all primary shoulder arthroplasty procedures undertaken for osteoarthritis in patients aged <55 years and reported to the registry between September 1999 and December 2021. Procedures were grouped into the following classes: total shoulder arthroplasty (TSA), hemiarthroplasty resurfacing (HRA), hemiarthroplasty stemmed metallic head (HSMH), hemiarthroplasty stemmed pyrocarbon head (HSPH), and reverse total shoulder arthroplasty (RTSA). The outcome measure was the cumulative percent revision, which was defined using Kaplan-Meier estimates of survivorship to describe the time to the first revision. Hazard ratios (HRs) were calculated from Cox proportional hazards models, adjusting for age and sex, to compare revision rates among groups., Results: There were 1564 shoulder arthroplasty procedures in patients aged <55 years, of which 361 (23.1%) were HRA, 70 (4.5%) were HSMH, 159 (10.2%) were HSPH, 714 (45.7%) were TSA, and 260 (16.6%) were RTSA. HRA had a higher rate of revision than RTSA after 1 year (HRA = 2.51 (95% CI 1.30, 4.83), P = .005), with no difference prior to that time. In addition, HSMH had a higher rate of revision than RTSA for the entire period (HR, 2.69 [95% confidence interval, 1.28-5.63], P = .008). There was no significant difference in the rate of revision for HSPH and TSA when they were compared with RTSA. Glenoid erosion was the most common cause of revision for HRA (28.6% of revisions) and HSMH (50%). Instability/dislocation was the leading cause of revision for RTSA (41.7%) and HSPH (28.6%), and for TSA, the majority of revisions were for either instability/dislocation (20.6%) or loosening (18.6%)., Conclusion: These results should be interpreted within the context of the lack of availability of long-term data on RTSA and HSPH stems. RTSA outperforms all implants regarding revision rates at mid-term follow-up. The high early dislocation rate associated with RTSA, as well as the lack of revision options available to address this, indicates that careful selection of patients and a greater appreciation of anatomic risk factors are needed in the future., (Copyright © 2023 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
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297. Shoulder joint arthroplasty in young patients: Analysis of 8742 patients from the Australian Orthopaedic Association National Joint Replacement Registry.
- Author
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McBride AP, Ross M, Duke P, Hoy G, Page R, Dyer C, and Taylor F
- Abstract
Background: Shoulder replacement is a reliable treatment for the relief of pain and improvement of function in patients with glenohumeral arthritis, rotator cuff arthropathy, osteonecrosis and fracture. Limited data is available comparing revision rates for the different types of shoulder replacement when used in younger patients. This study aims to compare the survivorship of hemi resurfacing, stemmed hemiarthroplasty, total shoulder arthroplasty and reverse total shoulder arthroplasty in younger patients using data from a large national arthroplasty registry., Methods: Data from the Australian Orthopaedic Association National Joint Replacement Registry was obtained for the period 16 April 2004-31 December 2018. The study population included all shoulder arthroplasty patients aged <65 years. These were stratified into two groups: <55 years and 55-64 years. A total of 8742 primary shoulder arthroplasty procedures were analysed (1936 procedures in the <55 years and 6806 in the 55-64 years age group)., Results: In the <55 years age group, there was no difference in revision rate for total shoulder arthroplasty versus reverse total shoulder arthroplasty at any time point. Reverse total shoulder arthroplasty had a lower revision rate after six months when compared to hemi resurfacing (HRA) (p = 0.031). Also, reverse total shoulder arthroplasty had a higher early rate of revision in the first 12 months compared to hemiarthroplasty (p = 0.018). However, from 2 years reverse total shoulder arthroplasty had a lower revision rate overall (p = 0.029).In the 55-64 years patient age group, reverse total shoulder arthroplasty had a lower earlier revision rate. This was statistically significant compared to hemi resurfacing (HRA) (p = 0.028), hemiarthroplasty (p = 0.049) and total shoulder arthroplasty (p < 0.001)., Conclusion: This study demonstrated that for patients aged <55 years there was no significant difference in the rate of revision when total shoulder arthroplasty and reverse total shoulder arthroplasty were compared. reverse total shoulder arthroplasty had a lower rate of revision when compared to hemi resurfacing and hemiarthroplasty after 2 years. reverse total shoulder arthroplasty had the lowest comparative revision rate in patients aged 55-64 years overall., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2021.)
- Published
- 2023
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298. Neck shaft angle in reverse shoulder arthroplasty: 135 vs. 145 degrees at minimum 2-year follow-up.
- Author
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Neyton L, Nigues A, McBride AP, and Giovannetti de Sanctis E
- Subjects
- Humans, Adult, Middle Aged, Follow-Up Studies, Retrospective Studies, Shoulder surgery, Range of Motion, Articular, Treatment Outcome, Arthroplasty, Replacement, Shoulder adverse effects, Shoulder Joint diagnostic imaging, Shoulder Joint surgery, Shoulder Prosthesis
- Abstract
Background: The most common complication with reverse shoulder arthroplasty Grammont based design with a 155° neck shaft angle (NSA) is scapular notching. Scapular notching has been associated with reduced clinical outcomes. Reducing the humeral NSA from 155° has been shown to reduce the incidence of scapular notching however it is unknown whether there is a difference in scapular notching between a 145° and 135° NSA. The purpose of this study was to evaluate the effect of decreasing the NSA on scapular notching rate and postoperative range of motion comparing 145° and 135° NSA stems at minimum 2 yr of follow-up., Methods: Consecutive patients undergoing primary reverse shoulder arthroplasty with a NSA of either 145° or 135° between January 2014 and February 2019 were retrospectively reviewed. Patients were included if they were over the age of 18, had minimum clinical follow-up of 24 mo with true postoperative anteroposterior radiographic view., Results: One hundred and three patients were included for the final analysis: 73 with a 145° NSA and 30 with a 135° NSA stem. The mean age and mean follow-up were respectively 70.9 yr (range, 52.0-89.0) and 32.1 mo. The overall incidence of scapular notching was 46.6 %. There was a statistically significant difference in scapular notching between the 145° (53.4%) and 135° (30%) NSA groups (P = .028). There was no difference in terms of postoperative Constant-Murley Score (mean, 66.1 vs. 68.2; P = .395), Subjective Shoulder Value (mean, 76.5 vs. 83.1%, P = .167), forward flexion (mean, 140° vs. 142°, P = .704), abduction (mean, 123.2° vs. 121.5°, P = .771), external rotation with the arm at the side (mean, 34.1° vs. 37.3°, P = .341) and internal rotation (mean, 5.3 vs. 5.4 pts P = .336) between the 2 groups., Conclusion: This is the first study to compare the effect of a 145° vs. 135° NSA on scapular notching rates. The key finding of this study is that scapular notching rate was significantly reduced from 53% to 30% in 135° NSA compared to 145° NSA, after at least 24 mo of follow-up. Our data also show that glenoid lateralization and inferiorization has an influence on scapular notching. We are unable to state that the reduced scapular notching rate was due to a reduction in NSA alone. Despite a lower rate of scapular notching, the 135° NSA group has not shown any significant better clinical and functional outcomes., (Copyright © 2023 Journal of Shoulder and Elbow Surgery Board of Trustees. Published by Elsevier Inc. All rights reserved.)
- Published
- 2023
- Full Text
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299. All-Arthroscopic Trillat Procedure Using Screw Fixation for Recurrent Shoulder Instability.
- Author
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McBride AP, Giovannetti de Sanctis E, Mukhi KS, and Neyton L
- Abstract
The Trillat procedure has been described for the management of shoulder instability in younger patients but also for shoulder instability in older patients with irreparable rotator cuff tears. We describe an all-arthroscopic technique using screw fixation. This technique allows for safe dissection, clearance and osteotomy of the coracoid, and direct visualization during screw tensioning and fixation to minimize the risk of subscapularis impingement. We outline our stepwise approach to medialize and distalize the coracoid process using arthroscopic screw fixation and present pearls to avoid fracture through the superior bone bridge., (© 2023 The Authors.)
- Published
- 2023
- Full Text
- View/download PDF
300. Severe monkeypox with superimposed bacterial infection in an immunocompetent patient: A case report.
- Author
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Manoharan A, Braz BX, McBride A, Hernandez S, Balfour M, Quiroz T, Powell A, Rodriguez A, Morris S, and Gonzales-Zamora JA
- Abstract
Monkeypox, a member of the Orthopoxvirus genu, has been the center of global attention since it has been declared a public health emergency by the World Health Organization. Typically, it is a self-limiting disease; however, it can occasionally have severe presentations in patients with underlying conditions, such as HIV, malignancy, and transplantation. In this article, we will present a case of an immunocompetent patient with a severe presentation of monkeypox. The patient presented with facial pustules with superimposed bacterial infection; furthermore, he had painful vesicles in oral and nasal mucosa and the penis. Dermatologic conditions such as atopic dermatitis has been associated with severe monkeypox. While our patient does not have a history of atopic dermatitis, he does report contact dermatitis as well as a history of skin infections. Researchers have hypothesized that disruption of the skin barrier allows for proliferation of the monkeypox virus; therefore, it is important to take a thorough history of the patient's skin conditions. Lastly, we described the use of Tecovirimat in our patient. Although it is impossible to demonstrate the efficacy of this medication without a randomized clinical trial, our patient seemed to have a faster improvement of the lesions after initiating this antiviral., Competing Interests: The authors declare no competing conflict of interest., (© 2022 The Authors.)
- Published
- 2022
- Full Text
- View/download PDF
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