196,072 research outputs found
The Energy Gallery: a pilot project in Pisa
No full textThe climate crisis will be the main driver of social pressure in the next twenty years. Large-scale urban coal tarred areas contribute immensely to the heat island effect and to excessive carbon emissions. One of the strategies that can guarantee results, in short term, is introducing energy generating galleries that can transform urban districts into power generators. Urban centres have a great capacity to be converted into beneficial galleries that can generate electricity using renewable sources and house within them a micro-climatic atmosphere that encourages urban agriculture. The present study provides possible solutions and applications of this approach through parametric model design and its simulated computer sided analysis in order to produce results for power generation (energy- plus), and overall benefits of comfort of proposing Power Plant Greenhouse Solar Galleries. The Energy Gallery project aims at identifying the potential of a new strategic design for energy generation at a urban scale. By strategically locating energygenerating/reducing systems like modular pavilions, green houses, winter gardens, or public facilities in the city's open spaces, we could reduce dioxide emissions by lowering the energy consumption due to public events and activities that are held inside. This would in turn increase energy generated by renewable sources and local food production, and at the same time ensure higher standards of comfort both inside and outside the pavilion. From the structural point of view, the pavilion is essentially made by a series of portals composed by TVT truss beam elements (Trave Vitrea Tensegrity - Tensegrity Glass Beam), designed and patented by M.Froli who leaded a research project at the University of Pisa aimed at the development of large spanned yet ductile glass beams. The original idea of the TVT constructional system consists in dry assembling laminated glass panels held together just by prestressed steel rods, according to the principle of Tensile Integrity [1],[2]. The entire project could be made thanks to a co-funding of the Tuscany Region [3] to let little or mean Tuscan manufacturers access to high tech projects and is presently owned by Roberglass Ltd
Intramedullary cavernoma: a surgical resection technique
No full textIntramedullary spinal cavernoma is a rare vascular disease constituting 5-12% of all spinal vascular tumors. The clinical course is usually characterized either by an acute neurological deterioration, recurrent episodes of neurological deficits or by a slowly progressive neurological decline. Microsurgical removal is recommended when the symptoms become clinically relevant and the lesion appears accessible. In this article, we present a surgical technique to completely resect an intramedullary cavernoma with the aid of intraoperative electrophysiological monitoring and intraoperative real-time ultrasound guidance. A brief description of current management of this pathology is also presented
Iliac Crest Fresh-Frozen Allografts Versus Autografts in Oral Pre-Prosthetic Bone Reconstructive Surgery : Histologic and Histomorphometric Study
No full textPurpose: The aim of this work was to compare histologically bone biopsies obtained during dental implant placement in atrophic jaws reconstructed with fresh-frozen bone (FFB) or autologous bone blocks. Materials and Methods: Twenty partially or totally edentulous patients were treated either with iliac crest FFB grafts (14 patients; group A) or with iliac crest autografts (6 patients; group B). Seven to 9 months later, dental implants were placed in the reconstructed jaws and bone biopsies were harvested. Results: The reconstructive procedure was uneventful in 9 patients of group A and in all patients of group B. Samples from both groups did not show relevant differences concerning the proportion of lamellar bone, newly formed bone, and bone marrow. In group A, the decreasing proportion of blood vessels from the apical to the coronal portion, the larger amount of lacunae in the apical portion, and the fewer vessels in the coronal portion than in group B evoke an effort of the host bone to "integrate" the graft from the apical portion. Conclusions: FFB cannot be considered as successful and safe in alveolar bone reconstruction as autogenous bone grafting
Rare Pathogens of Central Nervous System: a Systematic Literature Review and Report of Two New Cases of Cerebral Abscesses Due to Gemella morbillorum
No full textTo evaluate and characterize cases of brain abscess in immunocompetent patients due to Gemella morbillorum, an opportunistic
Gram-positive coccus. Two cases of brain abscess due to this pathogen which occurred at the authors’ native institution in 2013
and 2016 were analyzed. Moreover, a literature search regarding brain abscess surgically treated due to this pathogen was
performed in PubMed database, following PRISMA statement. The final review comprised ten articles for a total of 11
patients—all immunocompetent—with a median age of 50.2 years (range 28–77); almost total were males. Neurological deficits
and fever were the most common initial signs; seizures were present only in two cases. Surgical treatment was based on
craniotomy and excision in six cases; the remaining five underwent stereotactic aspiration. The antibiotic initial therapy was
intravenous in all cases. The average duration of therapy was of six weeks with a minimum of four and maximum of ten. One
patient died, while in the other cases, a complete or partial regression of presenting symptoms and disappearing of MRI signs at
intermediate follow-up were obtained. In eight patients (72%), it was possible to identify a primary infection or a predisposing
factor (as cardiac diseases or septic arthritis). G. morbillorum is an emerging pathogen involved in brain abscesses. Even if it is
infrequently reported, the identification of specific characteristics that may increase its neurotropism and virulence also in
immunocompetent patients can help to better understand such a rare pathology
Iliac crest fresh frozen allografts and autografts in maxillary reconstruction: a histologic and histomorphometric evaluation
No full textIliac crest fresh-frozen allografts and autografts in maxillary and mandibular reconstruction: a histologic and histomorphometric evaluation
No full textIliac crest fresh-frozen allografts and autografts in maxillary and mandibular reconstruction : a histologic and histomorphometric evaluation
No full textObiettivo. Confrontare istologicamente e istomorfometricamente l’integrazione di innesti ossei cortico-spongiosi in blocco di ala iliaca autologa ed omologa congelata (FBB, fresh-frozen bone) in chirurgia ricostruttiva pre-implantare dei mascellari.
Metodi. Dodici pazienti con siti alveolari edentuli e atrofici che richiedevano riabilitazione protesica su impianti sono stati sottoposti a ricostruzione con ala iliaca omologa (gruppo A, 6 pazienti) o ala iliaca autologa (gruppo B, 6 pazienti). Quattro-nove mesi più tardi sono stati inseriti gli impianti ed eseguite biopsie ossee per l’analisi istologica e istomorfometrica.
Risultati: il decorso postoperatorio è stato regolare in tutti i pazienti del gruppo B ed in tutti eccetto uno del gruppo A. Si sono verificate complicanze tardive in 5 pazienti del gruppo A, tuttavia è sempre stato possibile inserire impianti. I campioni del gruppo A mostravano osso vascolarizzato, cellule staminali osteoprogenitrici, segni di rimodellamento osseo e sporadiche aree di osso necrotico. Nel gruppo B l’osso presentava fronti di riassorbimento e neoapposizione e segni di rimodellamento. L’analisi istomorfometrica ha rivelato nel gruppo A il 24,7±14,7% di osso lamellare, il 28,4±13,3% di osso neoformato e il 46.9% ±16.9% di spazi midollari; nel gruppo B i valori corrispondenti erano 25,3±15,3%, 22,9±11,0% 51,7±15,7% (differenze tra gruppi statisticamente non significative, Wilcoxon test, P>0,05).
Conclusioni. Non si sono osservate differenze significative tra i campioni dei due gruppi. Sono necessari studi con più pazienti e maggiore follow-up per confermare che gli allotrapianti rappresentino una alternativa affidabile agli autotrapianti.Aim: The aim of this paper was to compare histologically and histomorphometrically the osseointegration of iliac crest fresh-frozen allografts and autografts in human pre-prosthetic maxillary and mandibular onlay bone blocks reconstruction.
Methods: Twelve patients with edentulous atrophic ridges, scheduled for implant-supported prosthetic restorations, underwent reconstruction using iliac crest fresh-frozen allografts (group A, six patients) or autografts (group B, six patients). Four-to-nine months later implants were placed in the augmented areas and bone specimens were simultaneously obtained using trephine burs. The specimens were processed for ground sections and evaluated histologically and histomorphometrically.
Results: The postoperative course was uneventful in all patients in group B and in all except one in group A. Late complications occurred in 5 patients of group A. Dental implants could be inserted in all cases. Specimens from group A showed a vascularized bone with osteoprogenitor stem cells and medium-high grade of bone remodeling. Small areas of necrotic bone were observed sporadically. Sections obtained from group B revealed an advanced stage of bone remodeling. The histomorphometric analysis showed in group A a mean proportion of 24.7±14.7% for lamellar bone, 28.4±13.3% for newly formed bone and 46.9±16.9% for bone marrow; in group B the corresponding values were 25.3±15.3%, 22.9±11.0%, 51.7±15.7%. No statistically significant difference was found (Wilcoxon Test; P>0.05).
Conclusion: There were no significant histological differences between group A and B. Larger studies with long term follow-up are needed to confirm that fresh-frozen allografts are a reliable alternative to autograft
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
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