2,200 research outputs found
Per una ricapitalizzazione efficacenete co-creativa dei sistemi territoriali italiani
La trasformazione creativa (innovazione) non dovrebbe essere immaginata se non come emergente dall’interazione interna (immanente) ai soggetti individuali o inter-individuali, piuttosto che da istanze separate e superiori (trascendenti). Il compito del planning dovrebbe quindi essere quello di rendere percepibili le potenzialità di cambiamento emergenti dall’interazione della molteplicità di detentori di quote di capitale urbano (stakeholder), che includono in pratica la totalità dei soggetti, e di fornire loro validi framework di orientamento e di scambio tra differenti, e spesso inconciliabili, sistemi di ‘valori’. Sono insomma richiesti approcci innovativi all’‘urbano’, per lo più contrastanti con le tradizionali prassi di investimento infrastrutturale, realizzate a scapito dell’investimento in ‘capitale umano’. Per superare la vieta dicotomia tra approcci top-down e bottom-up appare inoltro opportuno far riferimento a un nuovo modello di governance caratterizzato da reti auto-organizzate assimilabili a un fenomeno spontaneo guidato da processi sociali più che da obiettivi politici. A questo modello social di governance fanno riferimento i cosiddetti Living Lab urbani e territoriali, da considerare come veri e propri ecosistemi di agenzie che, interagendo co-creativamente, sembrano poter costituire un utile riferimento per l’integrazione multi scalare dei livelli di governo e che, attraverso la condivisione di un’idea di impresa e/o di una problematica, sembrano anche in grado di produrre concreti effetti di rigenerazione urbano-territoriale
Ultrasensitive Displacement Noise Measurement of Carbon Nanotube Mechanical Resonators
Mechanical resonators based on a single carbon nanotube are exceptional
sensors of mass and force. The force sensitivity in these ultra-light
resonators is often limited by the noise in the detection of the vibrations.
Here, we report on an ultra-sensitive scheme based on a RLC resonator and a
low-temperature amplifier to detect nanotube vibrations. We also show a new
fabrication process of electromechanical nanotube resonators to reduce the
separation between the suspended nanotube and the gate electrode down to ~nm. These advances in detection and fabrication allow us to reach
displacement sensitivity. Thermal
vibrations cooled cryogenically at 300~mK are detected with a signal-to-noise
ratio as high as 17~dB. We demonstrate
force sensitivity, which is the best force sensitivity achieved thus far with a
mechanical resonator. Our work is an important step towards imaging individual
nuclear spins and studying the coupling between mechanical vibrations and
electrons in different quantum electron transport regimes.Comment: 9 pages, 5 figure
Umbilical Cord Knots: Is the Number Related to Fetal Risk?
True knots of the umbilical cord (UC) are a rare occurrence and are reported in 0.4–1.2% of deliveries. The compression of true knot of the UC can cause obstruction of the fetal circulation, leading to intra‐uterine growth retardation or fetal death. Predisposing factors for the genesis of the true UC knot are numerous and include all the conditions, which lead to a relatively large uterine volume. This situation may predispose to free and excessive fetal movements. Although not all true knots lead to perinatal complications, they have been associated with adverse pregnancy outcomes, including fetal distress, fetal hypoxia, intra‐uterine growth restriction (IUGR), long‐term neurological damage, caesarean delivery and stillbirth. We present a rare case of operative delivery with vacuum in a multiparous woman at term of pregnancy with a double true knot of the UC. As in most cases, the diagnosis was made after delivery, as there were no fetal symptoms during pregnancy. Some authors assume that 3D power sonography may be useful in the diagnosis of true UC knots. However, 3D power Doppler cannot be considered as a definitive method. There are no specific prenatal indications to induce the physician to look for ultrasound signs suggestive of umbilical true knot. Some studies argue that cases of fetal death and fetal risk are directly related to the number of knots. We also support this thesis, even if further observational and retrospective studies are needed to demonstrate it
Lizards and snakes from the late Miocene hominoid locality of Ravin de la Pluie (Axios Valley, Greece)
We here describe lizards and snakes from the late Miocene (MN 10) of Ravin de la Pluie, near Thessaloniki, Greece, a locality widely known for its hominoid primate Ouranopithecus macedoniensis. The new finds comprise two large-sized lizards (a probable anguine and a varanid) and two snakes (an elapid and a small-sized “colubrine”). Even if the material is represented by few specimens, this is the first record of squamates from the late Miocene MN 10 biozone of southeastern Europe and the third only for the whole continent. The importance of the varanid vertebrae for systematic attributions is discussed. The new varanid limb elements described herein rank among the few such specimens in the fossil record of monitor lizards. Judging from the new and previously published varanid appendicular material, we suggest that Neogene monitor lizards from Europe possessed comparatively short and robustly built limbs. Distinctive scars on one of the limb elements are interpreted as bite marks of a predator or scavenger, offering insights on the palaeoecology of the herpetofauna of the locality
High performance bilayer-graphene Terahertz detectors
We report bilayer-graphene field effect transistors operating as THz
broadband photodetectors based on plasma-waves excitation. By employing
wide-gate geometries or buried gate configurations, we achieve a responsivity
and a noise equivalent power in the 0.29-0.38 THz range, in photovoltage and photocurrent mode.
The potential of this technology for scalability to higher frequencies and the
development of flexible devices makes our approach competitive for a future
generation of THz detection systems.Comment: 8 pages, 5 figures. Submitted to Applied Physics Letter
A simple approach for CTAB-free and biofunctionalized gold nanorods to construct photothermal active nanomedicine for potential in vivo applications in cancer cells and scar treatment
Cetyltrimethylammonium bromide (CTAB), a surfactant commonly used in the synthesis of gold nanorods (AuNR), presents challenges owing to cytotoxicity in biological applications, limiting their biomedical applicability, particularly in cancer therapy. This study introduces a straightforward methodology for the effective removal of CTAB by utilizing a combination of ligand replacement and surface bioconjugation processes that efficiently eliminates CTAB and simultaneously functionalizes nanorods with hyaluronic acid (HA) to enhance biocompatibility and introduce targeting capabilities toward cancer cells. The surface chemistry modification of CTAB-capped and CTAB-free AuNR, before and after the functionalization with HA, was scrutinized by UV–visible, surface-enhanced Raman scattering (SERS), attenuated total reflectance (ATR) Fourier-transform infrared (FTIR), and X-ray photoelectron (XPS) spectroscopies. The surface charge, size, and morphology of the different plasmonic nanoparticles were characterized by zeta potential, dynamic light scattering (DLS), and transmission electron microscopy (TEM). The photothermal response was assessed by laser irradiation and thermal camera measurements. Proof-of-work in vitro cellular experiments of cytotoxicity and oxidative stress were carried out on prostate cancer cells, PC-3, overexpressing the CD44 cell surface receptor specifically recognized by HA, in comparison with the CD44-negative murine fibroblasts (3T3 cell line) by MTT and MitoSOX assays, respectively. Cellular uptake and organelle alteration were scrutinized by confocal laser scanning microscopy (LSM), while the perturbative effects on cell migration were studied by optical microscopy (wound scratch assay). The study’s findings offer a promising pathway to tune the gold nanorod properties in cancer treatment by reducing cytotoxicity and enhancing targeted therapeutic efficacy, as well as in the control of scar tissue formation
MicroRNA-221 silencing attenuates the degenerated phenotype of intervertebral disc cells.
The aim of this study was to investigate the role of an antichondrogenic factor, MIR221 (miR‐221), in intervertebral disc degeneration (IDD), and provide basic information for the development of a therapeutic strategy for the disc repair based on specific nucleic acid based drugs, such as miR‐221 silencing. We established a relatively quick protocol to minimize artifacts from extended in vitro culture, without selecting the different types of cells from intervertebral disc (IVD) or completely disrupting extracellular matrix (ECM), but by using the whole cell population with a part of resident ECM. During the de‐differentiation process miR‐221 expression significantly increased. We demonstrated the effectiveness of miR‐221 silencing in driving the cells towards chondrogenic lineage. AntagomiR‐221 treated cells showed in fact a significant increase of expression of typical chondrogenic markers including COL2A1, ACAN and SOX9, whose loss is associated with IDD. Moreover, antagomiR‐221 treatment restored FOXO3 expression and increased TRPS1 expression levels attenuating the severity grade of degeneration, and demonstrating in a context of tissue degeneration and inflammation not investigated before, that FOXO3 is target of miR‐221. Data of present study are promising in the definition of new molecules useful as potential intradiscal injectable biological agents
Insulin-like growth factor-1 as predictive factor of difficult laryngoscopy in patients with GH-producing pituitary adenoma: A pilot study
Background: Growth hormone (GH)-producing pituitary tumors account for 10 to 15% of pituitary tumors. The hypersecretion of GH may induce changes in the airway anatomy through the activation of Insulin-like Growth factor 1(IGF-1) pathway. We sought investigate the role IGF-1 as a potential predictive factor of difficult laryngoscopy in patients with GH-producing pituitary adenoma. Methods: This study was a single center retrospective study. We included 33 patients undergoing transsphenoidal resection of GH-producing pituitary. We recorded demographic data, el-Ganzouri risk index (EGRI) and modified Look-Evaluate-Mallampati-Obstruction-Neck mobility (mLEMON) score, and pituitary hormone plasma levels. We performed ordinal logistic regression to analyze the relationship between IGF-1 and EGRI, mLEMON, and Cormack-Lehane Grade score and a multiple logistic regression to test the capability of EGRI, mLEMON and IGF-1 levels to predict Cormack-Lehane score. Receiver operating curve (ROC), area under the curve (AUC), and cut-off value of IGF-1 were calculated. Results: Only 14 (42.8%) and 12 (36.36%) patients showed predictive factors of difficult intubation according to EGRI and mLEMON score, respectively. IGF-1 significantly correlated with Cormack-Lehane (p = 0.005879) but not with mLEMON and EGRI (p = 0.3080 and 0.4146, respectively). In multiple regression model IGF-1 correlated only with Cormack-Lehane grade (p = 0.0089). Area under ROC was 0.8571 and cut-off value of IGF-1 was 186.15 ng/ml. Conclusion: Higher IGF-1 levels correlate with the probability of having a higher Cormack-Lehane score; classical bedside scores, such as mLEMON and EGRI, were not able to predict difficult laryngoscopy in our population
Noise-Resilient Group Testing: Limitations and Constructions
We study combinatorial group testing schemes for learning -sparse Boolean
vectors using highly unreliable disjunctive measurements. We consider an
adversarial noise model that only limits the number of false observations, and
show that any noise-resilient scheme in this model can only approximately
reconstruct the sparse vector. On the positive side, we take this barrier to
our advantage and show that approximate reconstruction (within a satisfactory
degree of approximation) allows us to break the information theoretic lower
bound of that is known for exact reconstruction of
-sparse vectors of length via non-adaptive measurements, by a
multiplicative factor .
Specifically, we give simple randomized constructions of non-adaptive
measurement schemes, with measurements, that allow efficient
reconstruction of -sparse vectors up to false positives even in the
presence of false positives and false negatives within the
measurement outcomes, for any constant . We show that, information
theoretically, none of these parameters can be substantially improved without
dramatically affecting the others. Furthermore, we obtain several explicit
constructions, in particular one matching the randomized trade-off but using measurements. We also obtain explicit constructions
that allow fast reconstruction in time \poly(m), which would be sublinear in
for sufficiently sparse vectors. The main tool used in our construction is
the list-decoding view of randomness condensers and extractors.Comment: Full version. A preliminary summary of this work appears (under the
same title) in proceedings of the 17th International Symposium on
Fundamentals of Computation Theory (FCT 2009
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