2,002 research outputs found
Production of the front-end boards of the LHCb muon system
This note describes the production of the front end boards CARDIAC, for the 1368 MWPC, and CARDIAC-GEM, for the 12 triple-GEM chambers, of the LHCb muon system. The PCB structure and component layout and the production issues, such as component soldering, quality assurance at the company and delivery rates, are described. The performance of these boards will be the subject of a future publication
Presenza di un «Potyvirus» sul Carciofo (<i>Cynara scolymus</i> L.) in Sardegna
A latent virus of artichoke has been isolated in Sardinia (Italy).
The virus causes characteristic local lesions on Gomphrena globosa L.
and Chenopodium amaranticolor Coste et Reyn., and systemic symptoms on
Nicotiana benthamiana Domin. and N. clevelandii Gray.
In artichoke crude sap the virus has a longevity in vitro of 20-30 hours,
a dilution-end point between 10-3 and 10-4 and a thermal inactivation
point between 55 and 60°C.
The purification of the virus has been obtained from artichoke with
two cicles of differential centrifugation followed by sucrose density gradient
centrifugation. The purified suspensions had an ultraviolet light (UV) ab
sorption spectrum typical of the nucleoproteins with Emax = 260-262 nm;
Emin = 246 nm; and a ratio E280/E260 of 0,85 which suggests a RNA content
of the virus of about 5,5%.
Electron microscope observation showed that negative stained partially
purified virus suspensions are composed of filamentous parti cles with a
normal lenght (NL) of 730 nm and a mode of the lenght distributions of
729 nm; moreover, ultrathin sections of tissue fragments from leaves of
mechanically inocu1ated Nicotiana benthamiana contained cytoplasmic inclusions
of the pinwheel type.
In serological tube tests, partially purified virus suspensions reacted
with homologous serum (titre 1 : 1024) and a serum immune to an ALV
(Artichoke Latent Virus) from Bari. These results have been substantially
confirmed by serological tests with the method of «antibody coating of
virus parti cles » by immune electron microscopy.
I t is obvious that a latent potyvirus is widespread in artichoke growing
in Sardinia. However, it cannot be exc1uded the possible occurrence in
artichoke plants of a latent carlavirus too
Characterization methodology for re-using marble slurry in industrial applications
Nowadays calcium carbonate has a great importance in different industrial fields and currently there is the opportunity of appreciate the potential value of marble waste and convert it into marketable products. Marble slurry samples, collected from different dimension stone treatment plants in Orosei marble district (Sardinia - Italy), were chemically, physically, mineralogically, and morphologically analyzed and the obtained data were evaluated for compatibility with the marketable micronized CaCO3 specifications required by some industrial sectors, estimating the prospects of recovered CaCO3 utilization. Besides the economic benefits, transforming a waste into an important economic resource involves environmental advantages, due to reduced marble waste landfills, and sustainability promotion
Scelta di un modello algebrico semplice per il calcolo degli scambi energetici nelle bovine in lattazione
In order to describe the energetic exchanges in lactating cows, various mathematic models both «mechanicistic»
and «empiric» types have been developed in recent years. The former type models make it possible
to evaluate the elementary processes, but require both the detailed knowledge of numerous variables and
the availability of suitable capacity computers. The latter type models are instead simpler to handle, but
they merely reproduce the experimental data, without adding any new information: among these models,
a simple algebraic one, originally devised by Wood, makes it possible, on the basis of III definited hypothesis,
to foresee the milk yield, the body weight variations and the energetic requirements of lactating cows.
This model has been tested on a sample of 50 Hostein Friesian cows, using a minicomputer with elementary
Basic; the results show an adeguate estimate of the paramethers, based on the study of easily identified
characteristics of the lactation curve
Discrepancies between in silico and in vitro data in the functional analysis of a breast cancer-associated polymorphism in the XRCC6/Ku70 gene.
An experimental study investigating the effect of pain relief from oral analgesia on lumbar range of motion, velocity, acceleration and movement irregularity
Background
Movement alterations are often reported in individuals with back pain. However the mechanisms behind these movement alterations are not well understood. A commonly cited mechanism is pain. The aim of this study was to investigate the effect of pain reduction, from oral analgesia, on lumbar kinematics in individuals with acute and chronic low back pain.
Methods
A prospective, cross-sectional, experimental repeated-measures design was used. Twenty acute and 20 chronic individuals with low back pain were recruited from General Practitioner and self-referrals to therapy departments for low back pain. Participants complained of movement evoked low back pain. Inertial sensors were attached to the sacrum and lumbar spine and used to measure kinematics. Kinematic variables measured were range of motion, angular velocity and angular acceleration as well as a determining movement irregularity (a measure of deviation from smooth motion). Kinematics were investigated before and after administration of oral analgesia to instigate pain reduction.
Results
Pain was significantly reduced following oral analgesia. There were no significant effects on the kinematic variables before and after pain reduction from oral analgesia. There was no interaction between the variables group (acute and chronic) and time (pre and post pain reduction).
Conclusion
The results demonstrate that pain reduction did not alter lumbar range of motion, angular velocity, angular acceleration or movement irregularity questioning the role of pain in lumbar kinematics
Prevention and modulation of aminoglycoside ototoxicity (Review)
More than 60 years after their isolation and characterization, aminoglycoside (AG) antibiotics remain powerful agents in the treatment of severe gram-negative, enterococcal or mycobacterial infections. However, the clinical use of AGs is hampered by nephrotoxicity and ototoxicity, which often develop as a consequence of prolonged courses of therapy, or of administration of increased doses of these drugs. The discovery of non-ototoxic antibacterial agents, showing a wider spectrum of activity, has gradually decreased the use of AGs as first line antibiotics for many systemic infections. However, AGs are now undergoing an unexpected revival, being increasingly indicated for the treatment of severe emerging infections caused by organisms showing resistance to most first-line agents (e.g., multidrug-resistant tuberculosis, complicated nosocomially-acquired acute urinary tract infections). Increasing adoption of aminoglycosides poses again to scientists and physicians the problem of toxicity directed to the kidneys and to the inner ear. In particular, aminoglycoside-induced deafness can be profound and irreversible, especially in genetically predisposed patients. For this reason, an impressive amount of molecular strategies have been developed in the last decade to counteract the ototoxic effect of aminoglycosides. The present article overviews: i) the molecular mechanisms by which aminoglycosides exert their bactericidal activity, ii) the mechanisms whereby AGs exert their ototoxic activity in genetically-predisposed patients, iii) the drugs and compounds that have so far proven to prevent or modulate AG ototoxicity at the preclinical and/or clinical level, and iv) the dosage regimens that have so far been suggested to decrease the incidence of episodes of AG-induced ototoxicity
Biocomposite from polylactic acid and lignocellulosic fibers: structure-property correlations
ABSTRACT
PLA biocomposites were prepared using three corncob fractions and a wood fiber as reference. The composites were characterized by tensile testing, scanning electron (SEM) and polarization optical (POM) microscopy. Micromechanical deformation processes were followed by acoustic emission measurements. The different strength of the components was proved by direct measurements. Two consecutive micromechanical deformation processes were detected in composites containing the heavy fraction of corncob, which were assigned to the fracture of soft and hard particles, respectively. The fracture of soft particles does not result in the failure of the composites that is initi-ated either by the fracture of hard particles or by matrix cracking. Very large particles debond easily from the matrix resulting in catastrophic failure at very low stresses. At sufficiently large shear stresses large particles break easily during compounding, thus reinforcement depending on interfacial adhesion was practically the same in all composites irrespectively of initial fiber characteristics
- …
