Influence of the C/O ratio on titanium and vanadium oxides in protoplanetary disks

Context. The observation of carbon-rich disks have motivated several studies questioning the influence of the C/O ratio on their gas phase composition in order to establish the connection between the metallicity of hot-Jupiters and that of their parent stars. Aims. We to propose a method that allows the characterization of the adopted C/O ratio in protoplanetary disks independently from the determination of the host star composition. Titanium and vanadium chemistries are investigated because they are strong optical absorbers and also because their oxides are known to be sensitive to the C/O ratio in some exoplanet atmospheres. Methods. We use a commercial package based on the Gibbs energy minimization technique to compute the titanium and vanadium equilibrium chemistries in protoplanetary disks for C/O ratios ranging from 0.05 to 10. Our calculations are performed for pressures ranging from 1e-6 to 1e-2 bar, and for temperatures ranging from 50 to 2000 K. Results. We find that the vanadium nitride/vanadium oxide and titanium hydride/titanium oxide gas phase ratios strongly depend on the C/O ratio in the hot parts of disks (T > 1000 K). Our calculations suggest that, in these regions, these ratios can be used as tracers of the C/O value in protoplanetary disks.Comment: Accepted for publication in A&

Histopathologic findings in malignant peripheral nerve sheath tumor predict response to radiotherapy and overall survival

BACKGROUND: Malignant peripheral nerve sheath tumor (MPNST) is an aggressive and poorly understood malignant neoplasm. Even in the setting of multimodal therapy, the clinical course of MPNST is frequently marked by metastatic conversion and poor overall prognosis, with optimal treatment paradigms for this rare tumor unknown. METHODS: We reviewed the medical records and histopathology of 54 consecutive patients who were treated at University of California San Francisco between 1990 and 2018. RESULTS: Our cohort consisted of 24 male and 30 female patients (median age 38 years). Fédération Nationale des Centres de Lutte Contre Le Cancer (FNCLCC) sarcoma grading criteria segregated patients into groups with differences in overall survival (OS) ( CONCLUSIONS: Our results lend support to the FNCLCC sarcoma grading criteria as a prognostic scheme for MPNST, although few cases of grade 1 were included. Further, we identify increased Ki-67 labeling as a strong predictor of poor OS from MPNST. Finally, we identify a subset of MPNSTs with a predictive immunohistochemical profile that has improved local control with adjuvant radiotherapy. These data provide insights into the grading and therapy for patients with MPNST, although further studies are needed for independent validation

A Comparison of Mycophenolate Mofetil With Mycophenolate Sodium in Renal Transplant Recipients on Tacrolimus-Based Treatment

We compared the tolerability and efficacy of mycophenolate mofetil (MMF) versus mycophenolate sodium (MPS) among renal transplant recipients on tacrolimus-based immunosuppression. The 105 patients who underwent kidney transplantation between January 2002 and March 2008 and were treated with steroid, tacrolimus, and a mycophenolic acid compound were enrolled in the study. From patient files we collected on demographics data, donors, immunosuppressive drug doses, biochemical and hematologic parameters, gastrointestinal and hematologic side effects, and kidney function. Fifty-six patients were prescribed MMF and 49 of them were taking MPS. Demographic parameters and pretransplantation dialysis duration were similar between the 2 groups. After the third month, the MPS dose was higher than that of MMF. There were no clinically important differences between the 2 groups, regarding other immunosuppressive drug doses. Gastrointestinal side effects were similar: 42.4% in the MMF versus 44.8% in the MPS group (P = .846). Six patients in the MMF group and 1 patient in the MPS group underwent a switch of the mycophenolic acid therapy due to severe gastrointestinal side effects (P =.183). Biopsy-proven acute rejection was reported in 6 patients on MMF and 7 patients on MPS therapy (P = .768). The log-rank test evaluating a 50% reduction in glomerular filtration rate (GFR) showed no significant difference between the 2 groups (P = .719). No deaths were recorded during the study period; there was only 1 graft loss, which occurred in the MMF group. We did not observe a significant difference in tolerability and efficacy between the 2 widely used mycophenolic acid derivatives. Economic considerations can be an important factor when choosing the drug

Influence of the C/O ratio on titanium and vanadium oxides in protoplanetary disks

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Spiral tacks may contribute to intra-abdominal adhesion formation

Purpose. With the inception of laparoscopic ventral hernia repair came a novel device not used in conventional hernia repair; the spiral tack. We conducted an experimental study on pigs to determine whether spiral tacks contribute to adhesion formation

Optic Nerve Diffusion Tensor Imaging Parameters and Their Correlation With Optic Disc Topography and Disease Severity in Adult Glaucoma Patients and Controls

PurposeTo evaluate optic nerve diffusion tensor imaging (DTI) parameters in glaucoma patients and controls, and to correlate DTI parameters with the rim area obtained with Heidelberg retina tomography (HRT) and with the severity of glaucomatous damage using the Glaucoma Staging System.DesignPilot study.MethodsTwenty-seven patients with glaucoma and 12 control subjects underwent DTI and HRT imaging. Main outcome measures included: fractional anisotropy, mean diffusivity, axial diffusivity, radial diffusivity, HRT rim area, and Glaucoma Staging System stage.ResultsIn group comparison, mean diffusivity (1.33 vs. 0.91 μm/ms, P=0.0002), axial diffusivity (1.70 vs. 1.43 μm/ms, P=0.036), and radial diffusivity (1.24 vs. 0.71 μm/ms, P<0.0001) were significantly higher and fractional anisotropy (0.21 vs. 0.44, P<0.0001) was significantly lower in the glaucoma compared with those of control subjects. In glaucoma patients, mean, axial, and radial diffusivities increased and fractional anisotropy decreased as rim area decreases and the Glaucoma stage increased (P<0.05). However, there were no statistically significant differences in the DTI parameters when adjacent pairs of stages were compared (P>0.05).ConclusionsDTI may be a useful technique for detection and evaluation of glaucomatous damage in the optic nerve, particularly for patients in whom conventional imaging and perimetry are not possible. Future studies are needed to evaluate how DTI parameters change longitudinally with glaucomatous damage within the visual pathways and address cerebrospinal fluid partial volume effects in diffusion tensor quantification, especially for patients with advanced glaucoma stage