• Title/Summary/Keyword: Murdoch

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Minimally invasive distal biceps tendon repair: a case series

  • Paul Jarrett;Anna-Lisa Baker
    • Clinics in Shoulder and Elbow
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    • v.26 no.3
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    • pp.222-230
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    • 2023
  • Background: Distal biceps tendon repairs are commonly performed using open techniques. A minimally invasive distal biceps tendon repair technique using a speculum and hooded endoscope was developed to improve visualization, reduce soft-tissue dissection, and minimize complications. This paper describes the technique and reports the outcomes of 75 minimally invasive distal biceps tendon repairs. Methods: The operation reports and outcomes of 75 patients who underwent distal biceps tendon repair using this technique between 2011 and 2021 were retrospectively reviewed. Results: Median time to follow-up was 12 months (interquartile range [IQR], 6-56 months). Primary outcomes were function as measured by the Disabilities of Arm, Shoulder and Hand Score (DASH) questionnaire, and rate of complications. Median DASH score was 1.7 of 100 (IQR, 0-6.8). There were 2 of 75 (2.7%) re-ruptures of the distal tendon. There were no cases of vascular injury, proximal radius fracture, or posterior interosseous nerve, median, or ulnar nerve palsy. Conclusions: In this series, minimally invasive distal biceps repair was safe and effective with a low rate of major complications. Recovery of function, as indicated by low DASH scores, was satisfactory, and inconvenience during recovery was minimized. Level of evidence: IV.

Dietary Bovine Colostrum Increases Villus Height and Decreases Small Intestine Weight in Early-weaned Pigs

  • King, M.R.;Morel, P.C.H.;Revell, D.K.;Pluske, J.R.;Birtles, M.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.21 no.4
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    • pp.567-573
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    • 2008
  • This experiment examined the effect of dietary spray-dried bovine colostrum on intestinal histology and organ weights in early-weaned pigs. In a randomised complete block design, twelve 14-day-old weaner pigs were offered a diet containing either 5% spray-dried bovine colostrum or no colostrum (control). Diets were formulated to contain 14.8 MJ/kg DE, 1.26% available lysine and to meet or exceed requirements for other nutrients. Piglets were offered the diets for a period of 14 days. No effect of diet on growth rate or feed intake was observed (p>0.10). Small intestine weight was reduced by 12% in piglets consuming dietary bovine colostrum (p< 0.05). Villous height and crypt depth were increased and decreased, respectively, in the proximal jejunum, mid jejunum and distal ileum of pigs consuming dietary bovine colostrum (p<0.05). Mid-jejunal lamina propria $CD4^+$ and $CD8^+$ T lymphocyte density was increased by 28 and 37%, respectively, in piglets consuming dietary bovine colostrum (p<0.05). Diet did not affect thickness of tunica muscularis externa or tunica submucosa (p>0.10). Collectively, these results suggest a positive effect of dietary bovine colostrum on intestinal morphology and immune status in early-weaned pigs.

Surface elasticity and residual stress effect on the elastic field of a nanoscale elastic layer

  • Intarit, P.;Senjuntichai, T.;Rungamornrat, J.;Rajapakse, R.K.N.D.
    • Interaction and multiscale mechanics
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    • v.4 no.2
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    • pp.85-105
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    • 2011
  • The influence of surface elasticity and surface residual stress on the elastic field of an isotropic nanoscale elastic layer of finite thickness bonded to a rigid material base is considered by employing the Gurtin-Murdoch continuum theory of elastic material surfaces. The fundamental solutions corresponding to buried vertical and horizontal line loads are obtained by using Fourier integral transform techniques. Selected numerical results are presented for the cases of a finite elastic layer and a semi-infinite elastic medium to portray the influence of surface elasticity and residual surface stress on the bulk stress field. It is found that the bulk stress field depends significantly on both surface elastic constants and residual surface stress. The consideration of out-of-plane terms of the surface stress yields significantly different solutions compared to previous studies. The solutions presented in this study can be used to examine a variety of practical problems involving nanoscale/soft material systems and to develop boundary integral equations methods for such systems.

A Systematic Review of Cervical Cancer Incidence and Mortality in the Pacific Region

  • Obel, J.;Souares, Y.;Hoy, D.;Baravilala, W.;Garland, S.M.;Kjaer, S.K.;Roth, A.
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.21
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    • pp.9433-9437
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    • 2014
  • This study provides the first systematic literature review of cervical cancer incidence and mortality as well as human papillomavirus (HPV) genotype prevalence among women with cervical cancer in the Pacific Island countries and territories. The cervical cancer burden in the Pacific Region is substantial, with age standardized incidence rates ranging from 8.2 to 50.7 and age standardized mortality rate from 2.7 to 23.9 per 100,000 women per year. The HPV genotype distribution suggests that 70-80% of these cancers could be preventable by the currently available bi- or quadrivalent HPV vaccines. There are only few comprehensive studies examining the epidemiology of cervical cancer in this region and no published data have hitherto described the current cervical cancer prevention initiatives in this region.

Developmental Changes of the Oocyte and Its Enveloping Layers, in Micropercops swinhonis (Pisces: Perciformes)

  • Park, Jong-Young;Richardson, Ken-C.Richardson;Kim, Ik-Soo
    • Animal cells and systems
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    • v.2 no.4
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    • pp.501-506
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    • 1998
  • In the goby Micropercops swinhonis, the development of its egg's enveloping layers could be divided into 4 stages. In the earliest developmental period, stage I, there is a simple oocyte surrounded by a layer of squamous follicular cells. Stage II corresponds to the yolk vesicle stage of vitellogenesis. Here the initial follicular layer has become bilaminar with the retention of its outer squamous cell layer and the acquisition of an inner cuboidal cell layer just over the zona radiata. The number and size of the cuboidal cells increases throughout this stage. Stage III corresponds to the yolk granule stage of true vitellogenesis. Here the cuboidal cells begin to be replaced by columnar cells. As the oocyte grows, the columnar cells increase in size. The columnar cells produce cytoplasmic neutral mucins and by the end of this stage their cytoplasm has been filled with this mucin. In stage IV a single layer of squamous cells still remained as the outer follicular layer of the oocyte. The secretory activity of the inner follicular layers' columnar cells has ceased and they had lost their cell wall integrity and ended as a series of bullet-shaped, neutral mucin deposits.

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Nonlocal-integro-vibro analysis of vertically aligned monolayered nonuniform FGM nanorods

  • Yuan, Yuan;Zhao, Ke;Zhao, Yafei;Kiani, Keivan
    • Steel and Composite Structures
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    • v.37 no.5
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    • pp.551-569
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    • 2020
  • Vibration of vertically aligned-monolayered-nonuniform nanorods consist of functionally graded materials with elastic supports has not been investigated yet. To fill this gap, the problem is examined using the elasticity theories of Eringen and Gurtin-Murdoch. The geometrical and mechanical properties of the surface layer and the bulk are allowed to vary arbitrarily across the length. The nonlocal-surface energy-based governing equations are established using differential-type and integro-type formulations, and solved by employing the Galerkin method by exploiting admissible modes approach and element-free Galerkin (EFG). Through various comparison studies, the effectiveness of the EFG in capturing both nonlocal-differential/integro-based frequencies is proved. A constructive parametric study is also conducted, and the roles of nanorods' diameter, length, stiffness of both inter-rod's elastic layer and elastic supports, power-law index of both constituent materials and geometry, nonlocal and surface effects on the dominant frequencies are revealed.

Stability of perforated nanobeams incorporating surface energy effects

  • Almitani, Khalid H.;Abdelrahman, Alaa A.;Eltaher, Mohamed A.
    • Steel and Composite Structures
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    • v.35 no.4
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    • pp.555-566
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    • 2020
  • This paper aims to present an analytical methodology to investigate influences of nanoscale and surface energy on buckling stability behavior of perforated nanobeam structural element, for the first time. The surface energy effect is exploited to consider the free energy on the surface of nanobeam by using Gurtin-Murdoch surface elasticity theory. Thin and thick beams are considered by using both classical beam of Euler and first order shear deformation of Timoshenko theories, respectively. Equivalent geometrical constant of regularly squared perforated beam are presented in simplified form. Problem formulation of nanostructure beam including surface energies is derived in detail. Explicit analytical solution for nanoscale beams are developed for both beam theories to evaluate the surface stress effects and size-dependent nanoscale on the critical buckling loads. The closed form solution is confirmed and proven by comparing the obtained results with previous works. Parametric studies are achieved to demonstrate impacts of beam filling ratio, the number of hole rows, surface material characteristics, beam slenderness ratio, boundary conditions as well as loading conditions on the non-classical buckling of perforated nanobeams in incidence of surface effects. It is found that, the surface residual stress has more significant effect on the critical buckling loads with the corresponding effect of the surface elasticity. The proposed model can be used as benchmarks in designing, analysis and manufacturing of perforated nanobeams.

Surface and small scale effects on the dynamic buckling of carbon nanotubes with smart layers assuming structural damping

  • Farokhian, Ahmad;Salmani-Tehrani, Mehdi
    • Steel and Composite Structures
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    • v.37 no.2
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    • pp.229-251
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    • 2020
  • In this paper, dynamic buckling of a smart sandwich nanotube is studied. The nanostructure is composed of a carbon-nanotube with inner and outer surfaces coated with ZnO piezoelectric layers, which play the role of sensor and actuator. Nanotube is under magnetic field and ZnO layers are under electric field. The nanostructure is located in a viscoelastic environment, which is assumed to obey Visco-Pasternak model. Non-local piezo-elasticity theory is used to consider the small-scale effect, and Kelvin model is used to describe the structural damping effects. Surface stresses are taken into account based on Gurtin-Murdoch theory. Hamilton principle in conjunction with zigzag shear-deformation theory is used to obtain the governing equations. The governing equations are then solved using the differential quadrature method, to determine dynamic stability region of the nanostructure. To validate the analysis, the results for simpler case studies are compared with others reported in the literature. Then, the effect of various parameters such as small-scale, surface stresses, Visco-Pasternak environment and electric and magnetic fields on the dynamic stability region is investigated. The results show that considering the surface stresses leads to an increase in the excitation frequency and the dynamic stability region happens at higher frequencies.

A semi-analytical study on the nonlinear pull-in instability of FGM nanoactuators

  • Attia, Mohamed A.;Abo-Bakr, Rasha M.
    • Structural Engineering and Mechanics
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    • v.76 no.4
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    • pp.451-463
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    • 2020
  • In this paper, a new semi-analytical solution for estimating the pull-in parameters of electrically actuated functionally graded (FG) nanobeams is proposed. All the bulk and surface material properties of the FG nanoactuator vary continuously in thickness direction according to power law distribution. Here, the modified couple stress theory (MCST) and Gurtin-Murdoch surface elasticity theory (SET) are jointly employed to capture the size effects of the nanoscale beam in the context of Euler-Bernoulli beam theory. According to the MCST and SET and accounting for the mid-plane stretching, axial residual stress, electrostatic actuation, fringing field, and dispersion (Casimir or/and van der Waals) forces, the nonlinear nonclassical equation of motion and boundary conditions are obtained derived using Hamilton principle. The proposed semi-analytical solution is derived by employing Galerkin method in conjunction with the Particle Swarm Optimization (PSO) method. The proposed solution approach is validated with the available literature. The freestanding behavior of nanoactuators is also investigated. A parametric study is conducted to illustrate the effects of different material and geometrical parameters on the pull-in response of cantilever and doubly-clamped FG nanoactuators. This model and proposed solution are helpful especially in mechanical design of micro/nanoactuators made of FGMs.

An investigation into the influence of thermal loading and surface effects on mechanical characteristics of nanotubes

  • Ebrahimi, Farzad;Shaghaghi, Gholam Reza;Boreiry, Mahya
    • Structural Engineering and Mechanics
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    • v.57 no.1
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    • pp.179-200
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    • 2016
  • In this paper the differential transformation method (DTM) is utilized for vibration and buckling analysis of nanotubes in thermal environment while considering the coupled surface and nonlocal effects. The Eringen's nonlocal elasticity theory takes into account the effect of small size while the Gurtin-Murdoch model is used to incorporate the surface effects (SE). The derived governing differential equations are solved by DTM which demonstrated to have high precision and computational efficiency in the vibration analysis of nanobeams. The detailed mathematical derivations are presented and numerical investigations are performed while the emphasis is placed on investigating the effect of thermal loading, small scale and surface effects, mode number, thickness ratio and boundary conditions on the normalized natural frequencies and critical buckling loads of the nanobeams in detail. The results show that the surface effects lead to an increase in natural frequency and critical buckling load of nanotubes. It is explicitly shown that the vibration and buckling of a nanotube is significantly influenced by these effects and the influence of thermal loadings and nonlocal effects are minimal.