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

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

Sulforaphane induces apoptosis in rhabdomyosarcoma and restores TRAIL-sensitivity in the aggressive alveolar subtype leading to tumor elimination in mice.

Rhadbomyosarcoma (RMS) is the most common soft-tissue sarcoma in children and is subdivided in the embryonal (ERMS) and alveolar (ARMS) subtypes, the latter being associated with the worst prognosis. We report that sulforaphane (SFN), a broccoli-derived anticancer isothiocyanate, causes dose- and time-dependent growth inhibition and apoptosis in both ERMS and ARMS cells. In ARMS, SFN induced the modulation of expression of crucial genes and proteins: mRNA and protein levels of PAX3-FKHR, MYCN, and MET decreased, while those of p21 and TRAIL-receptor DR5 (but not DR4) increased. Since DR5 expression increased specifically in ARMS, we treated ARMS cells with TRAIL, SFN, or their combination. While ARMS cells (RH30 and RH4) proved to be TRAIL-resistant, SFN restored their sensitivity to TRAIL-induced cell-growth inhibition, leading to a stronger effect in combination with TRAIL. ARMS cells transfected with siDR5 showed that SFN-induced DR5 acts as a key regulator, being directly related to the TRAIL-induced cell-growth inhibition. The in vivo anti-tumor activity of SFN and TRAIL was evaluated in a xenograft murine model of ARMS through microPET. The results showed that the systemic treatment (3 wk) of mice with SFN or TRAIL as single agents only delayed tumor evolution, while the combined treatment of SFN and TRAIL led to tumor elimination. These findings indicate that SFN triggers the apoptotic pathway in both alveolar and embryonal rhabdomyosarcomas and that combined treatment with SFN and TRAIL might be a promising therapy for the aggressive alveolar subtype

NEUROPROTECTIVE EFFECTS OF CORD BLOOD SERUM (CB-S) IN RAT MULLER CELLS UNDER OXIDATIVE STRESS

Cord blood (CB) is rich of trophic factors, including neurotrophins such as BDNF (Brain Derived Neurotrophic Factor), NGF (Nerve Growth Factor), GDNF (Glial Derived Neurotrophic Factor), TGF (Transforming Growth Factor)-\u3b1, and EGF (Epidermal Growth factor). The aim of this work was to evaluate the protective effect of CB Serum (CB-S), against the hydrogen peroxide (H2O2)-induced damage on rat retinal Muller cells

CT Scan Dosimetric Parameters Routine Monitoring: First Results of Radiation Dose Optimization Strategies Promptly Provided by a Multidisciplinary Team

CONCLUSION Radiation dose reduction, while saving image quality could be easily implemented with this approach. Furthermore, the availability of a dosimetric data archive provides immediate feedbacks, related to the implemented optimization strategies. Background JCI Standards and European Legislation (EURATOM 59/2013) require the implementation of patient radiation protection programs in diagnostic radiology. Aim of this study is to demonstrate the possibility to reduce patients radiation exposure without decreasing image quality, through a multidisciplinary team (MT), which analyzes dosimetric data of diagnostic examinations. Evaluation Data from CT examinations performed with two different scanners (Siemens DefinitionTM and GE LightSpeed UltraTM) between November and December 2013 are considered. CT scanners are configured to automatically send images to DoseWatch© software, which is able to store output parameters (e.g. kVp, mAs, pitch ) and exposure data (e.g. CTDIvol, DLP, SSDE). Data are analyzed and discussed by a MT composed by Medical Physicists and Radiologists, to identify protocols which show critical dosimetric values, then suggest possible improvement actions to be implemented. Furthermore, the large amount of data available allows to monitor diagnostic protocols currently in use and to identify different statistic populations for each of them. Discussion We identified critical values of average CTDIvol for head and facial bones examinations (respectively 61.8 mGy, 151 scans; 61.6 mGy, 72 scans), performed with the GE LightSpeed CTTM. Statistic analysis allowed us to identify the presence of two different populations for head scan, one of which was only 10% of the total number of scans and corresponded to lower exposure values. The MT adopted this protocol as standard. Moreover, the constant output parameters monitoring allowed us to identify unusual values in facial bones exams, due to changes during maintenance service, which the team promptly suggested to correct. This resulted in a substantial dose saving in CTDIvol average values of approximately 15% and 50% for head and facial bones exams, respectively. Diagnostic image quality was deemed suitable for clinical use by radiologists

Rationale behind the optimum efficiency of columns packed with new 1.9 μm fully porous particles of narrow particle size distribution

Columns packed with new commercially available 1.9 fully porous particles of narrow particle sizedistribution (nPSD) are characterized by extremely high efficiency. Under typical reversed phase con-ditions, these columns are able to generate very high number of theoretical plates (in the order of300,000 plates/m and more). In this paper, we investigate the origin of the high performance of thesenPSD columns by performing a series of measurements that include, in addition to the traditional deter-mination of the van Deemter curve, peak parking, pore blocking and inverse size exclusion experiments.Two nPSD columns (both 100 × 3.0 mm) have been considered in this study: the first one, packed withparticles of 80˚A pore size, is commercially available. The second one is a prototype column packed with1.9 fully porous particles of 120˚A pore size.The main conclusion of our study is that these nPSD columns are characterized by extremely low eddydispersion, while longitudinal diffusion and mass transfer kinetics are substantially equivalent to thoseof other fully porous particles of similar chemistr