2,337 research outputs found
Biological and mechanical enhancement of impacted allograft seeded with human bone marrow stromal cells: potential clinical role in impaction bone grafting
No full textWith the demographics of an aging population the incidence of revision surgery is rapidly increasing. Clinical imperatives to augment skeletal tissue loss have brought mesenchymal stem cells to the fore in combination with the emerging discipline of tissue engineering. Impaction bone grafting for revision hip surgery is a recognized technique to reconstitute bone, the success of which relies on a combination of mechanical and biological factors. The use of morsellized allograft is currently the accepted clinical standard providing a good mechanical scaffold with little osteoinductive biological potential. We propose that applying the principles of a tissue engineering paradigm, the combination of human bone marrow stromal cells (hBMSCs) with allograft to produce a living composite, offers a biological and mechanical advantage over the current gold standard of allograft alone. This study demonstrates that hBMSCs combined with allograft can withstand the forces equivalent to a standard femoral impaction and continue to differentiate and proliferate along the bony lineage. In addition, the living composite provides a biomechanical advantage, with increased interparticulate cohesion and shear strength when compared with allograft alone
Esperienza ed evento della verità. Pratica filosofica e astrazione scientifica nel pensiero di A.N. Whitehead
No full textThis article analyzes the relationship between philosophy, experience and event in A.N. Whitehead’s thought. From the critics of the concept of object, the author retraces and describes the peculiar “abstract-concrete dialectic”, at the center of the researches concerning the perceptual experience.
Furthermore, according to Whitehead’s later works, she demonstrates how the philosophical practice is different from all other kinds of science, although it requires science itself because of the co-implication of object and event, abstraction and recognition
Il "Guerrin Meschino" di Gesualdo Bufalino : un'"opra" in versi
No full textGesualdo Bufalino first published Il Guerrin Meschino in 1991 in a non-commercial edition. In 1993, after a deep revision, he re-published his work with publisher Bompiani: the novel has a modified plot, and the author decided to insert three new poems in addition to the opening and closing poems, formerly present in 1991’s edition. This paper, in its entirety supported by handwritten material preserved at Fondazione Gesualdo Bufalino (Comiso), is divided in two parts: the first part illustrates the differences between the first and the second edition, the second part provides a critical edition of the five poems
Nurse led versus lay educators support for those with asthma in primary care: a costing study
No full text<p>Background - Regular review and support for asthma self-management is promoted in guidelines. A randomised controlled trial suggested that unscheduled health care usage was similar when patients were offered self management support by a lay-trainer or practice nurses.</p>
<p>Methods - Following the RCT, a costing study was undertaken using the trial data to account for the cost of delivery of the service under both strategies and the resulting impact on unscheduled healthcare (measure of effectiveness) in this trial.</p>
<p>Results - One year data (n = 418) showed that 29% (61/205) of the nurse group required unscheduled healthcare (177 events) compared with 30.5% (65/213) for lay-trainers (178 events).</p>
<p>The training costs for the lay-trainers were greater than nurses (£36 versus £18 respectively per patient, p<0.001), however, the consultation cost for lay-trainers were lower than nurses (£6 per patient versus £24, p<0.001). If the cost of unscheduled healthcare are accounted for then the costs of nurses is £161, and £135 for lay-trainers (mean difference £25, [95% CI = −£97, £149, p = 0.681]). The total costs (delivery and unscheduled healthcare) were £202 per patient for nurses versus £178 for lay-trainers, (mean difference £24, [95%CI = −£100, £147, p = 0.707]).</p>
<p>Conclusions - There were no significant differences in the cost of training and healthcare delivery between nurse and lay trainers, and no significant difference in the cost of unscheduled health care use.</p>
A FEW WORDS ABOUT THE TEACHER. IN MEMORY OF THE EXCELLENT TEACHER AND SCIENTIST M.R. SAPIN
No full textM.R. Sapin (1925–2015) was a professor at I.M. Sechenov First Moscow State Medical University, honorary academician of Russian academy of medical sciences (1988), and an outstanding representative of the Moscow anatomical school of the middle of XX – early XXI century. From the very beginning of his medical training, Mikhail Romanovich got interested in anatomy, especially in angiology and lymphology, and later concentrated on its studying. The author of more than 30 text books and guidelines for schools, universities, and colleges, Mikhail Romanovich was the doctoral and thesis advisor of 51 Ph.D. and approximately 70 MD dissertations. M.R. Sapin made a significant contribution to the development of anatomical education providing the departments with a various range of dry and wet specimens. His stunning and effective work as a tutor was highly appreciated by his students and colleagues, Russian and foreign anatomists. M.R. Sapin was the leader of the Laboratory of Functional Anatomy since 1972, president of the International Association of Morphologists (1992–2006), chairman of the expert commission of Higher Attestation Commission (1959–1994), etc. A man of a great willpower, M.R. Sapin faced a lot of obstacles in his life and research work but overcame that all successfully. The article presents the most important facts of anatomist’s career and lifetime.</jats:p
Taking tissue engineering principles into theatre: augmentation of impacted allograft with human bone marrow stromal cells
No full textHuman bone marrow contains bone progenitor cells that arise from multipotent mesenchymal stem cells. Seeding bone progenitor cells onto a scaffold can produce a 3D living composite with significant mechanical and biological potential. This article details laboratory and clinical findings from two clinical cases, where different proximal femoral conditions were treated using impacted allograft augmented with marrow-derived autogenous progenitor cells. Autologous bone marrow was seeded onto highly washed morselized allograft and impacted. Samples of the impacted graft were also taken for ex vivo analysis. Both patients made an uncomplicated clinical recovery. Imaging confirmed defect filling with encouraging initial graft incorporation. Histochemical and alkaline phosphatase staining demonstrated that a live composite graft with osteogenic activity had been introduced into the defects. These studies demonstrate that marrow-derived cells can adhere to highly washed morselized allograft, survive the impaction process and proliferate with an osteoblastic phenotype, thus creating a living composite
Verslag van het voorgevallene tijdens het hooge opperwater op de Nederlandsche rivieren in den winter van 1919 op 1920
No full textNadat de Rijn op 20 December 1919 tot even beneden den middelbaren zomerstand 1901-1910 (M.R.) was gedaald vertoonde zich op die rivier een sterke en vrij snelle was, waardoor het water te Keulen tot 6m +M.R. bij het einde van het jaar steeg. In de daarop volgende 11 dagen daalde de waterstand tot 1.5m +M.R. om daarna in 5 dagen weder te rijzen tot den zeer hoogen stand van 7m +M.R. Door een aanvankelijk sterken later flauweren val liep de stand weder terug tot 1.5m +M.R. op 30 Januari. Ook op de Maas vertoonden zich twee dicht op elkaar volgende sterke wassen. Bij den aanvang van den eersten was op 19 december stond het water te Maastricht op ruim 1m +M.R. en steeg het in 6 dagen tot 4.37m +M.R.; in de daaropvolgende 9 dagen bleef de stand steeds hoger dan 4m +M.R. en daalde toen tot ongeveer 2m +M.R. op 10 Januari 1920. De tweede was trad op laatsgenoemde datum in waarbij het water oplied tot 4.94m +M.R. op 15 Januari. Het water daalde daarna dadelijk en was op 29 Januari tot ongeveer 2m +M.R. weggevallen. Bij den tweeden was op Rijn en Maas werden de hoogst bekende waterstanden bij open rivieren overtroffen te Keulen met 7 cm en te Maastricht met 2 cm. De rivieren waren ijsvrij.Hoogwaterversla
Effect of carbon nanoparticle addition on epoxy cure
No full textThe thesis reports studies of cure kinetics and the glass transition
temperature advancements of three commercial epoxy resin systems: MY 750
/ HY 5922 (Vantico), MTM 44 -1 (ACG) and 8552 (Hexcel Composites). This
investigation was conducted with the utilisation of Differential Scanning
Calorimetry (DSC) and Temperature Modulated DSC (TMDSC). Appropriate
phenomenological cure kinetics models were built to predict the degree of
cure as a function of temperature/time profile. The validity of superposition of
dynamic and isothermal experimental data was established. Rheological
measurements were performed in order to determine the gelation region
under given cure conditions. The cure modelling methodology was validated
against an international Round-Robin exercise led by the University of British
Columbia (Canada).
The effects of carbon nanoparticle incorporation on the cure kinetics and
the glass transition temperature advancement of two of the epoxy systems
were also studied. Cure kinetics models were developed for the
nanocomposites containing commercial multiwalled carbon nanotubes and a
direct comparison was made with the models of the neat resin systems. The
glass transition temperature advancement is shown to be affected in the early
stages of the cure.
The state of the dispersion of the nanoparticles was studied in order to
correlate it with the observed effects upon the cure and on the morphology of
the cured samples. The presence of carbon nanotube clusters is shown to
have an influence on the phase separation in the MTM 44-1 resin system.
As a potential industrial application of this study, optical fibre
refractometers were utilised as an on-line cure monitoring technique. A good
correlation was established between the measured refractive index changes
during the cure and the degree of cure predicted by the above mentioned
models, for the neat resin systems and their nanocomposites
Rural-Urban Migration and the Intergenerational Transmission of Wealth
No full textReplaced with revised version of paper 07/24/08.Overlapping Generations Model, Rural-Urban Migration, Poverty Traps, Agglomeration Economies, Place-based Policies, Person-based Policies, Consumer/Household Economics, Labor and Human Capital, R13, R58, O15,
Seismic prevention and rahabilitation of nonstructural elements. Criteria to define a post-seismic damage analysis procedure
No full textIt reports very briefly the research work, developed by the author during her Doctorate course, about a post-seismic damage analysis procedure for nonstructural elements of framed structure building system
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