7,304 research outputs found
Out‐of‐plane reinforcement of masonry walls using joint-embedded steel cables
The out-of-plane mechanism (rocking) of walls often causes fatalities and collapses of historic buildings during earthquakes. This paper addresses the problem of assessing the seismic resistance of walls subjected to out-of-plane bending, before and after reinforcement. A new retrofitting method, consisting in the use of high-strength steel cables fully embedded in the mortar bed joints was studied. An experimental investigation using full-scale brickwork specimens was therefore conducted in an attempt to assess the walls’ structural response when these are subject to out-of-plane loads. Test results demonstrated that it is possible to increase the out-of-plane capacity with the proposed method. A simplified macro-element procedure is also presented along with recommendations for the calculation of the walls’ capacity before and after the application of the steel cable reinforcement. Predictions of the magnitude of horizontal force required to cause out-of-plane failure using the proposed procedure and quasi-static analysis procedures are compared with the results of laboratory experiments
Chemical communication between synthetic and natural cells: a possible experimental design
The bottom-up construction of synthetic cells is one of the most intriguing
and interesting research arenas in synthetic biology. Synthetic cells are built
by encapsulating biomolecules inside lipid vesicles (liposomes), allowing the
synthesis of one or more functional proteins. Thanks to the in situ synthesized
proteins, synthetic cells become able to perform several biomolecular
functions, which can be exploited for a large variety of applications. This
paves the way to several advanced uses of synthetic cells in basic science and
biotechnology, thanks to their versatility, modularity, biocompatibility, and
programmability. In the previous WIVACE (2012) we presented the
state-of-the-art of semi-synthetic minimal cell (SSMC) technology and
introduced, for the first time, the idea of chemical communication between
synthetic cells and natural cells. The development of a proper synthetic
communication protocol should be seen as a tool for the nascent field of
bio/chemical-based Information and Communication Technologies (bio-chem-ICTs)
and ultimately aimed at building soft-wet-micro-robots. In this contribution
(WIVACE, 2013) we present a blueprint for realizing this project, and show some
preliminary experimental results. We firstly discuss how our research goal
(based on the natural capabilities of biological systems to manipulate chemical
signals) finds a proper place in the current scientific and technological
contexts. Then, we shortly comment on the experimental approaches from the
viewpoints of (i) synthetic cell construction, and (ii) bioengineering of
microorganisms, providing up-to-date results from our laboratory. Finally, we
shortly discuss how autopoiesis can be used as a theoretical framework for
defining synthetic minimal life, minimal cognition, and as bridge between
synthetic biology and artificial intelligence.Comment: In Proceedings Wivace 2013, arXiv:1309.712
Sodium hydroxide pretreatment as an effective approach to reduce the dye/holes recombination reaction in P-Type DSCs
We report the synthesis of a novel squaraine dye (VG21-C12) and investigate its behavior
as p-type sensitizer for p-type Dye-Sensitized Solar Cells. The results are compared
with O4-C12, a well-known sensitizer for p-DSC, and sodium hydroxide pretreatment
is described as an effective approach to reduce the dye/holes recombination. Various
variable investigation such as dipping time, dye loading, photocurrent, and resulting cell
efficiency are also reported. Electrochemical impedance spectroscopy (EIS) was utilized
for investigating charge transport properties of the different photoelectrodes and the
recombination phenomena that occur at the (un)modified electrode/electrolyte interface
Implementation of an IP table lookup algorithm based on an Adaptive Stratified Tree
IP Table Lookup is one of the bottlenecks operation of a router. M. Pellegrini, G. Fusco and G. Vecchiocattivi in Adaptive Stratified Search Trees for IP Table Lookup (manuscript) presented a new solution for this problem based on a data structure called Adaptive Stratified Tree (AST). The algorithm has been implemented and compared with the state of the art software solution, notably the LC-Trie of S. Nilsson and G. Karlson. Here we present some experimental results and the complete C code of our program
Carbon, nitrogen and fungal mycelium in the organic and in the mineral soil layers across a chronosequence of Stone pine forest on Mount Vesuvius.
Effect of efflux pump inhibition on Pseudomonas aeruginosa transcriptome and virulence
Efflux pumps of the resistance-nodulation-cell-division (RND) family increase antibiotic resistance in many bacterial pathogens, representing candidate targets for the development of antibiotic adjuvants. RND pumps have also been proposed to contribute to bacterial infection, implying that efflux pump inhibitors (EPIs) could also act as anti-virulence drugs. Nevertheless, EPIs are usually investigated only for their properties as antibiotic adjuvants, while their potential anti-virulence activity is seldom taken into account. In this study it is shown that RND efflux pumps contribute to Pseudomonas aeruginosa PAO1 pathogenicity in an insect model of infection, and that the well-characterized EPI Phe-Arg-β-naphthylamide (PAβN) is able to reduce in vivo virulence of the P. aeruginosa PAO1 laboratory strain, as well as of clinical isolates. The production of quorum sensing (QS) molecules and of QS-dependent virulence phenotypes is differentially affected by PAβN, depending on the strain. Transcriptomic and phenotypic analyses showed that the protection exerted by PAβN from P. aeruginosa PAO1 infection in vivo correlates with the down-regulation of key virulence genes (e.g. genes involved in iron and phosphate starvation). Since PAβN impacts P. aeruginosa virulence, anti-virulence properties of EPIs are worthy to be explored, taking into account possible strain-specificity of their activit
Analysis on the mechanical effects induced by beam impedance heating on the HL-LHC target dump injection segmented (TDIS) absorber
The High Luminosity Large Hadron Collider (HL-LHC) Project at CERN calls for increasing beam brightness and intensity. In such a scenario, critical accelerator devices need to be redesigned and rebuilt. Impedance is among the design drivers, since its thermo-mechanical effects could
lead to premature device failures. In this context, the current work reports the results of a multiphysics study to assess the electromagnetic and thermo-mechanical behaviour of the Target Dump Injection Segmented (TDIS). It first discusses the outcomes of the impedance analysis performed to characterise the resistive wall and the high order resonant modes (HOMs) trapped in the TDIS structures. Then, their
RF-heating effects and the related temperature distribution are considered. Finally, mechanical stresses induced by thermal gradients are studied in order to give a final validation on the design qualit
Visceral Adiposity Index Is Associated with Insulin Sensitivity and Adipocytokine Levels in Newly Diagnosed Acromegalic Patients.
Context:
The visceral adiposity index (VAI) has proved to be a marker of visceral adipose dysfunction, strongly associated with insulin sensitivity in both the general and specific populations of patients at metabolic risk.
Objective:
The objective of the study was to test VAI as a useful tool to assess early metabolic risk in acromegaly.
Patients:
Twenty-four newly diagnosed acromegalic patients (11 women and 13 men, aged 54.9 ± 13.6 yr) were grouped into those with normal (group A, n = 13, 54.2%) and those with high VAI (group B, n = 11, 45.8%).
Outcome Measures:
Glucose, hemoglobin A1c, nadir and area under the curve (AUC) of GH (AUCGH) during the oral glucose tolerance test, AUCCpeptide during a mixed-meal tolerance test, M value during euglycemic-hyperinsulinemic clamp, oral dispositional index (DIo), each component of the metabolic syndrome, leptin, adiponectin, TNF-α, and IL-6.
Results:
The VAI value was positively correlated with the age of patients (ρ = 0.408; P = 0.048), tumor volume (ρ = 0.638; P = 0.001), basal GH (ρ = 0.622; P = 0.001), nadir GH (ρ = 0.534; P = 0.007), AUCGH (ρ = 0.603; P = 0.002), IGF-I (ρ = 0.618; P = 0.001), TNF-α (ρ = 0.512; P = 0.010), and AUCCpeptide (ρ = 0.715; p<0.001) and negatively with adiponectin (ρ = −0.766; P < 0.001), M value (ρ = −0.818; P < 0.001), and DIo (ρ = −0.512; P = 0.011). Patients with high VAI showed significantly higher basal GH levels (P = 0.018), AUCGH (P = 0.047), IGF-I (P = 0.047), AUCCpeptide (P = 0.018), lower M value (P < 0.001), DIo (P = 0.006), and adiponectin levels (P < 0.001), despite the absence of a significantly higher prevalence in the overt metabolic syndrome and glucose tolerance abnormalities. AUCGH proved to be the main independent factor influencing VAI.
Conclusions:
In acromegaly, VAI appears to be associated with disease activity, adiponectin levels, and insulin sensitivity and secretion and is influenced independently by GH levels. VAI could therefore be used as an easy and useful new tool in daily clinical practice for the assessment of early metabolic risk associated with active acromegal
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