Seismic amelioration of existing reinforced concrete buildings. Strategy to optimize the amount of reinforcement for joints

Most of the existing Reinforced Concrete (RC) buildings in Italy were built according to obsolete regulations that were not enough aware of issues related to seismic design so that they need to be upgraded by pursuing either amelioration or full seismic rehabilitation. In doing that, the first step is to figure out what is, based on the results of the initial analysis of the structure in its ante-operam version, the best overall dissipative mechanism that could be ob-tained by a number of suitable and economically convenient local interventions. The choice of the overall dissipative mechanism strongly affects the amount of reinforcement to be adopted for the beam-column joints. For new buildings, the current adopted capacity design philosophy pursues an overall beam-sway mechanism in which plastic hinges first form in beams and at last at the base of the columns. On the contrary,for existing ones, often very irregular and gravity-load-dominated, pursuing such overall mechanism may result either uneconomic or even extremely difficult to implement due to the amount of reinforcement to be inserted in the joints. In such cases, an overall dissipative mechanism allowing, at some extent, columns flex-ural plasticizationshould be accepted and clearly identified in advance. Anyway,such ap-proach needs to be addressed properly in order to avoid the formation of column-sways at one story only that would result very dangerous due to the excessive demand of plastic rotations on the resulting hinges. This paper presents two simple models that may help the designer in deal-ing with the operations above. The formeris a model that allows to understand if, given the existing RC building case-study, either the beam-sway or a hybrid beam-column-sway mecha-nism should be conveniently pursued during the design of the retrofitting intervention. The lat-ter isa model that allows to design a hybrid beam-column-sway overall mechanism involving a suitable number of stories such as to guarantee a uniform and reasonable demand of plastic rotations in the involved columns

The cleavable presequence is not essential for import and assembly of the phosphate carrier of mammalian mitochondria but enhances the specificity and efficiency of import.

The phosphate carrier (PiC) of mammalian mitochondria is synthesized with a cleavable presequence, in contrast to other members of the mitochondrial family of inner membrane carrier proteins. The precursor of PiC is efficiently imported, proteolytically processed, and correctly assembled in isolated mitochondria. Here we report that a presequence-deficient PiC was imported with an efficiency of about 50% as compared with the authentic precursor of PiC. This mature-sized PiC was correctly assembled, demonstrating that the presequence is not essential for the assembly pathway. We found the following functions for the PiC presequence. (i) The presequence by itself was able to target a passenger protein to mitochondria with a low efficiency, suggesting that the mammalian PiC contains multiple targeting signals, the more efficient one(s) present in the mature protein part. (ii) Deletion of the presequence allowed a more efficient heterologous import of mammalian PiC into mitochondria from Saccharomyces cerevisiae and Neurospora crassa, indicating an important role of the presequence in determining the specificity of PiC import. (iii) Import of the presequence-deficient PiC required a higher membrane potential across the inner membrane than that of the presequence-carrying form. Therefore, the presequence also enhances the translocation of PiC into the inner membrane

Sarande: water, forma terrae and forma urbis

Ponència presentada a: Session 9: Diseño e Historia (modernidad y tradición) / Design and History (modernity and tradition

Sarande: water, forma terrae and forma urbis

Ponència presentada a: Session 9: Diseño e Historia (modernidad y tradición) / Design and History (modernity and tradition

Co-sputtered amorphous Nb–Ta, Nb–Zr and Ta–Zr coatings for corrosion protection of cyclotron targets for [18F] production

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Early Effects of P-15 on Human Bone Marrow Stem Cells

OBJECTIVES: Peptide-15 (P-15) is an analogue of the cell binding domain of collagen. P-15 has been shown to facilitate physiological to process in a way similar to collagen, to serve as anchorage for cells, and to promote the binding, migration and differentiation of cells. However, how P-15 alters osteoblast activity to promote bone formation is poorly understood. To study the osteoinductive properties of peptide P-15, we analyzed the expression levels of bone related genes in human mesenchymal stem cells treated with this biomaterial. MATERIAL AND METHODS: Using real time Reverse Transcription-Polymerase Chain Reaction the quantitative expression of specific genes, like transcriptional factors (RUNX2 and SP7), bone related genes (SPP1, COL1A1, COL3A1, BGLAP, ALPL, and FOSL1) and mesenchymal stem cells marker (ENG) were examined. RESULTS: P-15 causes a considerable induction of osteoblast transcriptional factor like osterix (SP7) and of the bone related genes osteopontin (SPP1) and osteocalcin (BGLAP). In contrast the expression of endoglin (ENG) was markedly decreased in stem cells treated with P-15 respect to untreated cells, indicating the differentiation effect of this biomaterial on stem cells. CONCLUSIONS: The present study shows the effect of P-15 on mesenchymal stem cells in the early differentiation stages: P-15 is an inducer of osteogenesis on human stem cells as indicated by the activation of bone related markers SP7, SPP1 and BGLAP.The results may allow a better understanding of the molecular mechanism of bone regeneration and as a model for comparing other materials with similar clinical effects

A Diagnosis of Inflammatory Pseudotumor of the Liver by Contrast Enhaced Ultrasound and Fine-Needle Biopsy: A Case Report

Inflammatory pseudotumor (IPT) of the liver is a rare, benign lesion of unclear etiology, which may be misdiagnosed as hepatocellular carcinoma, cholangiocarcinoma, secondary tumor or abscess, because of its non-specific clinical, biochemical and radiologic findings. We present the case of a 48-old-year male in whom diagnosis of liver IPT was suspected by contrast enhanced ultrasound (CEUS) and confirmed by fine-needle liver biopsy. The diagnosis is in contrast to most of the literature reports in which the diagnosis was made only based on a surgical specimen

Nonischemic left ventricular scar and cardiac sudden death in the young

Nonischemic Left Ventricular Scar (NLVS) is a pattern of myocardial injury characterized by midventricular and/or subepicardial gadolinium hyper enhancement at cardiac magnetic resonance, in absence of significant coronary artery disease. We aimed to evaluate the prevalence of NLVS in juvenile sudden cardiac death and to ascertain its aetiology at autopsy. We examined 281 consecutive cases of sudden death of subjects aged 1 to 35 years of age. NLVS was defined as a thin, grey rim of subepicardial and/or midmyocardial scar in the left ventricular free wall and/or the septum, in absence of significant stenosis of coronary arteries. NLVS was the most frequent finding (25%) in sudden deaths occurring during sports. Myocardial scar was localized most frequently within the left ventricular posterior wall, and affected the subepicardial myocardium, often extending to the midventricular layer. On histology it consisted of fibrous or fibro-adipose tissue. Right ventricular involvement was always present. Patchy lymphocytic infiltrates were frequent. Genetic and molecular analyses clarified the aetiology of NLVS in a subset of cases. ECG recordings were available in over half of subjects. The most frequent abnormality was the presence of low QRS voltages (< 0,5 mV) in limb leads. In serial ECG tracings, the decrease in QRS voltages appeared, in some way progressive. NLVS is the most frequent morphologic substrate of juvenile cardiac sudden death in sports. It can be suspected based on ECG findings. Autopsy study and clinical screening of family members are required to differentiate between Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia and chronic acquired myocarditis

The Master athlete: An extraordinary physiological model of aging study, a delicate issue for cardiologists and sports physicians

The prolongation of average life in the industrialized countries and the definitive demonstration of preventive and therapeutic role of regular physical exercise and sport, have greatly increased the number of middle-aged and older subjects engaged in the regular practice of sports activities, not only for fun or healthy purposes, but also at competitive level. The creation by sports federations of age categories (five years in five years) has strengthened the agonistic nature of the activity. Master athletes compete not only against adversaries of the same age group but even against themselves and the Time flowing inexorably. At the scientific and clinical level, two are the fundamental implications of this phenomenon. The first is the positive effect of a regular and intense performance training, both anaerobic and aerobic power. In the latter, regular and intense training is able to slow down significantly (even 50%) the natural, progressive decline of cardiorespiratory functions observed in healthy sedentary subjects of the same age. The second, the reverse of the medal, is the difficulty encountered by sports physician and cardiologist to correctly interpret the clinical/instrumental features of the Master athlete who undergoes pre-participation screening for competitive sports. It is not always easy to differentiate the physiological, adaptive, changes of a middle-aged and older athlete from the pathological ones, related to cardiovascular disease, typical of aging, such as ischemic heart disease, arrhythmias, hypertension, valvular diseases. These difficulties can only be solved by having an adequate knowledge of the clinical and instrumental manifestations of the Master Athlete’s Heart and individual cardiopathies, and with the careful use of all modern cardiological instrumental investigations. In addition to echocardiography and maximal ECG stress-test (preferably cardio-pulmonary test), the magnetic resonance imaging with Gadolinium, and coronary tomography (TC) are playing a decisive role. [1