The Tesla turbine is an original expander working on the principle of torque transmission by wall shear stress. The principle – demonstrated for air expanders at lab scale - has attractive features ...when applied to ORC expanders: it is suitable for handling limited flow rates (as is the case for machines in the range from 500 W to 5 kW), it can be developed to a reasonable size (rotor diameters between 0.1 and 0.3 m), with limited rotational speeds (from 1000 to 12000 rpm). The original concept is revisited, improving the stator layout (which is the main responsible for poor performance) and developing a modular design allowing to cover a wide power range, as well as to realize a perfectly sealed operation and including other fluid dynamics improvements. The flow model assumes complete real fluid behaviour, and includes several new concepts such as bladed channels for the stator and a detailed treatment of losses. Preliminary design sketches are presented and results discussed and evaluated. Several working fluids are considered, from refrigerants (R245fa, R134a, SES36) to hydrocarbons (n-Hexane, n-Pentane).
Breast cancer is the most common cancer among women worldwide. Molecular and clinical evidence indicated that Fragile X Messenger Ribonucleoprotein 1 (FMRP) plays a role in different types of cancer, ...including breast cancer. FMRP is an RNA binding protein that regulates the metabolism of a large group of mRNAs coding for proteins involved in both neural processes and in epithelial-mesenchymal transition, a pivotal mechanism that in cancer is associated to tumor progression, aggressiveness and chemoresistance. Here, we carried out a retrospective case-control study of 127 patients, to study the expression of FMRP and its correlation with metastasis formation in breast cancer. Consistent with previous findings, we found that FMRP levels are high in tumor tissue. Two categories have been analyzed, tumor with no metastases (referred as control tumors, 84 patients) and tumor with distant metastatic repetition, (referred as cases, 43 patients), with a follow-up of 7 years (mean). We found that FMRP levels were lower in both the nuclei and the cytoplasm in the cases compared to control tumors. Next, within the category cases (tumor with metastases) we evaluated FMRP expression in the specific sites of metastasis revealing a nuclear staining of FMRP. In addition, FMRP expression in both the nuclear and cytoplasmic compartment was significantly lower in patients who developed brain and bone metastases and higher in hepatic and pulmonary sites. While further studies are required to explore the underlying molecular mechanisms of FMRP expression and direct or inverse correlation with the secondary metastatic site, our findings suggest that FMRP levels might be considered a prognostic factor for site-specific metastasis.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•The relevant mouse models for monogenic forms of ASDs are described.•The most common behavioral tasks related to core symptoms of ASD are discussed.•Translation of human behavioral deficits into ...animal models is considered.
Autism Spectrum Disorders are a heterogeneous group of neurodevelopmental disorders, with rising incidence but little effective therapeutic intervention available. Currently two main clinical features are described to diagnose ASDs: impaired social interaction and communication, and repetitive behaviors. Much work has focused on understanding underlying causes of ASD by generating animal models of the disease, in the hope of discovering signaling pathways and cellular targets for drug intervention. Here we review how ASD behavioral phenotypes can be modeled in the mouse, the most common animal model currently in use in this field, and discuss examples of genetic mouse models of ASD with behavioral features that recapitulate various symptoms of ASD.
This study examined the effectiveness of a short-duration but high-intensity exercise countermeasure in combination with a novel oral volume load in preventing bed rest deconditioning and orthostatic ...intolerance. Bed rest reduces work capacity and orthostatic tolerance due in part to cardiac atrophy and decreased stroke volume. Twenty seven healthy subjects completed 5 wk of -6 degree head down bed rest. Eighteen were randomized to daily rowing ergometry and biweekly strength training while nine remained sedentary. Measurements included cardiac mass, invasive pressure-volume relations, maximal upright exercise capacity, and orthostatic tolerance. Before post-bed rest orthostatic tolerance and exercise testing, nine exercise subjects were given 2 days of fludrocortisone and increased salt. Sedentary bed rest led to cardiac atrophy (125 ± 23 vs. 115 ± 20 g; P < 0.001); however, exercise preserved cardiac mass (128 ± 38 vs. 137 ± 34 g; P = 0.002). Exercise training preserved left ventricular chamber compliance, whereas sedentary bed rest increased stiffness (180 ± 170%, P = 0.032). Orthostatic tolerance was preserved only when exercise was combined with volume loading (-10 ± 22%, P = 0.169) but not with exercise (-14 ± 43%, P = 0.047) or sedentary bed rest (-24 ± 26%, P = 0.035) alone. Rowing and supplemental strength training prevent cardiovascular deconditioning during prolonged bed rest. When combined with an oral volume load, orthostatic tolerance is also preserved. This combined countermeasure may be an ideal strategy for prolonged spaceflight, or patients with orthostatic intolerance.
Abstract
The multi-TeV energy region of the cosmic-ray spectra has
been recently explored by direct detection experiments that used
calorimetric techniques to measure the energy of the cosmic
...particles. Interesting spectral features have been observed in both
all-electron and nuclei spectra. However, the interpretation of the
results is compromised by the disagreements between the data
obtained from the various experiments, that are not reconcilable
with the quoted experimental uncertainties. Understanding the
reason for the discrepancy among the measurements is of fundamental
importance in view of the forthcoming high-energy cosmic-ray
experiments planned for space, as well as for the correct
interpretation of the available results.
The purpose of this work is to investigate the possibility that a
systematic effect may derive from the non-proportionality of the
light response of inorganic crystals, typically used in high-energy
calorimetry due to their excellent energy-resolution performance.
The main reason for the non-proportionality of the crystals is that
scintillation light yield depends on ionisation density.
Experimental data obtained with ion beams were used to characterize
the light response of various scintillator materials. The obtained
luminous efficiencies were used as input of a Monte Carlo simulation
to perform a comparative study of the effect of the light-yield
non-proportionality on the detection of high-energy electromagnetic
and hadronic showers. The result of this study indicates that, if
the calorimeter response is calibrated by using the energy deposit
of minimum ionizing particles, the measured shower energy might be
affected by a significant systematic shift, at the level of few
percent, whose sign and magnitude depend specifically on the type of
scintillator material used.
Abstract
The measurement of cosmic-ray individual spectra provides
unique information regarding the origin and propagation of
astro-particles. Due to the limited acceptance of current space
...experiments, protons and nuclei around the “knee” region
(∼ 1 PeV) can only be observed by ground based
experiments. Thanks to an innovative design, the High Energy
cosmic-Radiation Detection (HERD) facility will allow direct
observation up to this energy region: the instrument is mainly based
on a 3D segmented, isotropic and homogeneous calorimeter which
properly measures the energy of particles coming from each direction
and it will be made of about 7500 LYSO cubic crystals. The read-out
of the scintillation light is done with two independent systems: the
first one based on wave-length shifting fibers coupled to
Intensified scientific CMOS cameras, the second one is made of two
photo-diodes with different active areas connected to a custom
front-end electronics. This photo-diode system is designed to
achieve a huge dynamic range, larger than 10
7
, while having a
small power consumption, few mW per channel. Thanks to a good
signal-to-noise ratio, the capability of a proper calibration, by
using signals of both non-interacting and showering particles, is
also guaranteed. In this paper, the current design and the
performance obtained by several tests of the photo-diode read-out
system are discussed.
Background In 1966, five 20-year-old men underwent a comprehensive physiological evaluation of the capacity for adaptation of the cardiovascular system in response to 3 weeks of bed rest and 8 weeks ...of heavy endurance training; these same participants were reevaluated before and after training at the age of 50. The aim of the present study was to reexamine these same men 40 years following the original assessments. Methods and Results In all three studies, minute ventilation and expired gases were analyzed during exercise testing with Douglas bag collection. Cardiac output (CO) was determined using the acetylene rebreathing technique. Compared with the original 30-year interval, the decline in maximal oxygen uptake (VO2max) (−11% vs −25%), maximal CO (+6% vs −11%), and maximal stroke volume (+10% vs −10%) were greater between 50 and 60 years of age. The annualized decline in VO2max (55 mL/min/y) between ages 50 and 60 was approximately fourfold higher than the decline between 20 and 50 years (12 mL/min/y). Conclusions In the original five participants of the Dallas Bed Rest and Training Study, VO2max declined after 40 years of living due to a balanced decrease in central and peripheral determinants of oxygen uptake. The rate of decline in VO2max and its components accelerated after the age of 50 years secondary to age and clinical comorbidities. The net proportional decline in VO2max for a period of 40 years of life was comparable with that experienced after 3 weeks of strict bed rest at the age of 20 (27% vs 26%, respectively).
The Tesla turbine is an original expander working on the principle of torque transmission by wall shear stress. The principle – demonstrated for air expanders at lab scale has some attractive ...features when applied to two-phase expanders: it is suitable for handling limited flow rates (as is the case for machines in the range from 500W to 5 kW), it can be developed to a reasonable size (rotor of 0.1 to 0.25 m diameters), with acceptable rotational speeds (which range from 500 to 10000 rpm). The original concept was revisited, designing it for two-phase operation and considering not only the rotor configuration but the whole machine. The flow model was developed using complete real fluid assumptions including several new concepts such as bladed channels for the stator, labyrinth seals, and a rotating diffuser. Preliminary design sketches are presented, and results discussed and evaluated.
The direct detection of high-energy cosmic rays up to the PeV region is one of the major challenges for the next generation of space-borne cosmic-ray detectors. The physics performance will be ...primarily determined by their geometrical acceptance and energy resolution. CaloCube is a homogeneous calorimeter whose geometry allows an almost isotropic response, so as to detect particles arriving from every direction in space, thus maximizing the acceptance. A comparative study of different scintillating materials and mechanical structures has been performed by means of Monte Carlo simulation. The scintillation-Cherenkov dual read-out technique has been also considered and its benefit evaluated.
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