39 research outputs found
Implementazione di un sistema di registrazione e monitoraggio dosimetrico degli esami radiologici digitali
X-ray diffraction and computational studies of the pressure-dependent tetrachloroethane solvation of diphenylanthracene
The crystal structure of the organic semiconductor 9,10-diphenylanthracene (DPA) has been studied by
single-crystal X-ray diffraction at variable pressure up to 3 GPa. Under ambient conditions and in the presence
of 1,1,2,2-tetrachloroethane, the material invariably crystallises in an unsolvated form, in the space
group C2/c, with Z\u2032 = 1/2, as reported in the literature. As pressure is increased to a modest 0.5 GPa,
crystallisation occurs in the form of a newly discovered solvate with a 1 : 2 DPA\u2013tetrachloroethane stoichiometry,
with the space group P21/c. A theoretical analysis by the PIXEL method with energy partitioning
into Coulombic polarisation and dispersion terms reveals that the solvated and unsolvated structures have
in common two basic packing motifs for the DPA molecule, one with linear interlocking and one with a
T-shaped arrangement in a quincunx fashion. The solvent is enclosed in a cage and interacts with the DPA
molecule by a very strong dispersive component of 44 kJ mol 121. Monte Carlo simulations show that the
mobility of the solvent in its cage would be extremely reduced even under ambient conditions, ruling out a
mechanism of solvate formation and subsequent release. According to a structure-oriented perspective,
the kinetics of the process could then be such that the nucleating system at ambient pressure separates
out the solvent, while a 0.5 GPa pressure provides a solute\u2013solvent grip that forces cocrystallisation, in
agreement with both experiments and simulations. Even in the absence of experimental or computational
proof of the thermodynamic stability of the solvate at high pressure, this appears to be a plausible and sensible
case scenario in its own right
PO-0857: GTV-based prescription and Monte Carlo treatment planning in Cyberknife treatments for lung lesions
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A Lateral Flow Immunoassay Kit for the Detection of Tropical House Dust Mite Blomia Tropicalis
IgE-mediated allergic reactions such as asthma, atopic dermatitis and allergic rhinitis are triggered by allergens such as those from the house dust mite Blomia tropicalis (Bt). Detection of allergens is crucial in the management and prevention of allergic diseases. The study aimed to provide a proof of concept for a sandwich-format lateral flow immunoassay (LFIA) kit for the detection of Bt-specific proteins using gold nanoparticle-labeled polyclonal antibodies. Anti-Bt polyclonal antibodies produced from rabbits were purified using Protein A chromatography, and were labeled with gold nanoparticles (AuNP) synthesized using the citrate reduction method. These were then dispensed on glass fiber pad that serves as the conjugate pad. Test and control lines were established through the immobilization on nitrocellulose membrane pad of the unlabeled antibodies and anti-rabbit IgG respectively. The LFIA kit was constructed from the assembly of cellulose fiber pad as the sample pad, conjugate pad, and the nitrocellulose membrane pad. The anti-Bt polyclonal antibody concentration was 0.99 mg/mL upon purification and pre-concentration. Gold nanoparticles with 21.2 ± 1.0 nm diameter as observed under transmission electron microscope, were used for antibody conjugation at an optimal pH of 8.5 (borate buffer) and an optimal ratio of 10 µL 50 µg/mL antibody:100 µL AuNP. Optimal conditions such as color intensity and fastest migration time were observed with the treatment of 0.05 % Tween20 and 10 % sucrose in the conjugate pads; 5 % bovine serum albumin (BSA) and 0.05 % Tween20 in the sample pads, and 1 % BSA in the test pads. The limit of detection of the Bt LFIA is 0.054 µg/mL. This study provides a prototype for a low-cost, rapid, and equipment-free detection of Blomia tropicalis-specific proteins
Factors affecting outcome in frameless non-isocentric stereotactic radiosurgery for trigeminal neuralgia: A multicentric cohort study
Background: Stereotactic radiosurgery (SRS) is an effective treatment for trigeminal neuralgia (TN). Nevertheless, a proportion of patients will experience recurrence and treatment-related sensory disturbances. In order to evaluate the predictors of efficacy and safety of image-guided non-isocentric radiosurgery, we analyzed the impact of trigeminal nerve volume and the nerve dose/volume relationship, together with relevant clinical characteristics. Methods: Two-hundred and ninety-six procedures were performed on 262 patients at three centers. In 17 patients the TN was secondary to multiple sclerosis (MS). Trigeminal pain and sensory disturbances were classified according to the Barrow Neurological Institute (BNI) scale. Pain-free-intervals were investigated using Kaplan Meier analyses. Univariate and multivariate Cox regression analyses were performed to identify predictors. Results: The median follow-up period was 38 months, median maximal dose 72.4 Gy, median target nerve volume 25 mm3, and median prescription dose 60 Gy. Pain control rate (BNI I-III) at 6, 12, 24, 36, 48, and 60 months were 96.8, 90.9, 84.2, 81.4, 74.2, and 71.2%, respectively. Overall, 18% of patients developed sensory disturbances. Patients with volume 65 30 mm3 were more likely to maintain pain relief (p = 0.031), and low integral dose (< 1.4 mJ) tended to be associated with more pain recurrence than intermediate (1.4-2.7 mJ) or high integral dose (> 2.7 mJ; low vs. intermediate: log-rank test, \u3c72 = 5.02, p = 0.019; low vs. high: log-rank test, \u3c72 = 6.026, p = 0.014). MS, integral dose, and mean dose were the factors associated with pain recurrence, while re-irradiation and MS were predictors for sensory disturbance in the multivariate analysis. Conclusions: The dose to nerve volume ratio is predictive of pain recurrence in TN, and re-irradiation has a major impact on the development of sensory disturbances after non-isocentric SRS. Interestingly, the integral dose may differ significantly in treatments using apparently similar dose and volume constraints
Hypertension, Diabetes and Neurodegenerative Diseases: Is there a Clinical Link through the Ca2+/cAMP Signalling Interaction?
PO-0776: Output factors measurements with radiochromic films for small fields on a Cyberknife unit
Increased migration of a human glioma cell line after in vitro CyberKnife irradiation
A human glioblastoma multiforme cell line (U87) and its derived-spheroids were irradiated either using a conventional irradiation (CIR) or a CK-like irradiation (IIR) in which the 8 Gy was delivered intermittently over a period of 40 min. The ability of glioma cells to migrate into a matrigel matrix was evaluated on days 1-8 from irradiation. Irradiation with CK-driven IIR significantly increased the invasion potential of U87 cells in a matrigel-based assay. In contrast to CIR, IIR was associated with increased levels of TGF beta at four days (real-time PCR), beta 1-integrin at 4-5 d (real-time PCR and protein gel blot) and no elevation in phosphorylated AKT at days 4 and 5 (protein gel blot). Our data suggests that glioma cell invasion as well as elevations of TGF beta and beta 1-integrin are associated with IIR and not CIR
Indoor and outdoor in-flight odometry based solely on optic flows with oscillatory trajectories
International audienceEstimating distance traveled is a frequently arising problem in robotic applications designed for use in environments where GPS is only intermittently or not at all available. In UAVs, the presence of weight and computational power constraints makes it necessary to develop odometric strategies based on minimilastic equipment. In this study, a hexarotor was made to perform up-and-down oscillatory movements while flying forward in order to test a self-scaled optic flow based odometer. The resulting self-oscillatory trajectory generated series of contractions and expansions in the optic flow vector field, from which the flight height of the hexarotor could be estimated using an Extended Kalman Filter. For the odometry, the downward translational optic flow was scaled by this current visually estimated flight height before being mathematically integrated to obtain the distance traveled. Here we present three strategies based on sensor fusion requiring no, precise or rough prior knowledge of the optic flow variations generated by the sinusoidal trajectory. The “rough prior knowledge” strategy is based on the shape and timing of the variations in the optic flow. Tests were performed first in a flight arena, where the hexarotor followed a circular trajectory while oscillating up and down over a distance of about [Formula: see text] m under illuminances of [Formula: see text] lux and [Formula: see text] lux. Preliminary field tests were then performed, in which the hexarotor followed a longitudinal bouncing [Formula: see text]-long trajectory over an irregular pattern of grass