308 research outputs found
trans-1,2-Difluoro-3,4,5,6,7,8-hexaphenyltricyclo[4.2.0.0^(2,5)]octa-3,7-diene
In order to probe the possible mechanism of the rearrangement of trans-hexaphenyldifluorotricyclooctadiene (a dimer of fluorotriphenylcyclobutadiene) to pentaphenyldihydrodifluoropentalene via C-F bond migration, a high-temperature study of the title compound, C_(44)H_(30)F_2, was performed at 400 (2) K. In the title compound, there are three fused four-membered rings with the resulting eight-membered tricyclo¬octa¬diene ring adopting a sofa conformation. The dihedral angles between the central four-membered ring and the two outer rings are 66.03 (2) and 65.39 (2)°. The crystal structure contains centrosymmetric dimers formed by C-H… π inter¬actions
Synthesis, structure and ionic conductivity in scheelite type Li<sub>0.5</sub>Ce<sub>0.5-x</sub>Ln<sub>x</sub>MoO<sub>4</sub> (x = 0 and 0.25, Ln = Pr, Sm)
Scheelite type solid electrolytes, Li0.5Ce0.5-xLnxMoO4 (x = 0 and 0.25, Ln = Pr, Sm) have been synthesized using a solid state method. Their structure and ionic conductivity (σ) were obtained by single crystal X-ray diffraction and ac-impedance spectroscopy, respectively. X-ray diffraction studies reveal a space group of I41/a for Li0.5Ce0.5-xLnxMoO4 (x = 0 and 0.25, Ln = Pr, Sm) scheelite compounds. The unsubstituted Li0.5Ce0.5-xLnxMoO4 showed lithium ion conductivity ∼10−5-10−3 Ω−1cm−1 in the temperature range of 300-700°C (σ = 2.5 × 10−3 Ω−1cm−1 at 700°C). The substituted compounds show lower conductivity compared to the unsubstituted compound, with the magnitude of ionic conductivity being two (in the high temperature regime) to one order (in the low temperature regime) lower than the unsubstituted compound. Since these scheelite type structures show significant conductivity, the series of compounds could serve in high temperature lithium battery operations
Microwave photovoltage and photoresistance effects in ferromagnetic microstrips
We investigate the dc electric response induced by ferromagnetic resonance in
ferromagnetic Permalloy (Ni80Fe20) microstrips. The resulting magnetization
precession alters the angle of the magnetization with respect to both dc and rf
current. Consequently the time averaged anisotropic magnetoresistance (AMR)
changes (photoresistance). At the same time the time-dependent AMR oscillation
rectifies a part of the rf current and induces a dc voltage (photovoltage). A
phenomenological approach to magnetoresistance is used to describe the distinct
characteristics of the photoresistance and photovoltage with a consistent
formalism, which is found in excellent agreement with experiments performed on
in-plane magnetized ferromagnetic microstrips. Application of the microwave
photovoltage effect for rf magnetic field sensing is discussed.Comment: 16 pages, 15 figure
(2R*,3R*,4aS*,6aR*,11aS*,11bS*)-Methyl 2-acetoxy-11b-hydroxy-3,7-dimethyl-1,2,3,4,4a,5,6,6a,7,11,11a,11b-dodecahydrophenanthro[3,2-b]furan-3-carboxylate
In the title compound, C22H30O6, the conformation of the molecule is dictated by an intramolecular C—H⋯O contact. The crystal structure is stabilized via intermolecular C—H⋯O, O—H⋯O and C—H⋯π contacts
Ripples in a pond: Do social work students need to learn about terrorism?
In the face of heightened awareness of terrorism, however it is defined, the challenges for social work are legion. Social work roles may include working with the military to ensure the well-being of service-men and women and their families when bereaved or injured, as well as being prepared to support the public within the emergency context of an overt act of terrorism. This paper reviews some of the literature concerning how social work responds to confl ict and terrorism before reporting a smallscale qualitative study examining the views of social work students, on a qualifying programme in the UK, of terrorism and the need for knowledge and understanding as part of their education
Randomized, Noncomparative, Phase II Trial of Early Switch From Docetaxel to Cabazitaxel or Vice Versa, With Integrated Biomarker Analysis, in Men With Chemotherapy-Naïve, Metastatic, Castration-Resistant Prostate Cancer
Purpose The TAXYNERGY trial ( ClinicalTrials.gov identifier: NCT01718353) evaluated clinical benefit from early taxane switch and circulating tumor cell (CTC) biomarkers to interrogate mechanisms of sensitivity or resistance to taxanes in men with chemotherapy-naïve, metastatic, castration-resistant prostate cancer. Patients and Methods Patients were randomly assigned 2:1 to docetaxel or cabazitaxel. Men who did not achieve ≥ 30% prostate-specific antigen (PSA) decline by cycle 4 (C4) switched taxane. The primary clinical endpoint was confirmed ≥ 50% PSA decline versus historical control (TAX327). The primary biomarker endpoint was analysis of post-treatment CTCs to confirm the hypothesis that clinical response was associated with taxane drug-target engagement, evidenced by decreased percent androgen receptor nuclear localization (%ARNL) and increased microtubule bundling. Results Sixty-three patients were randomly assigned to docetaxel (n = 41) or cabazitaxel (n = 22); 44.4% received prior potent androgen receptor-targeted therapy. Overall, 35 patients (55.6%) had confirmed ≥ 50% PSA responses, exceeding the historical control rate of 45.4% (TAX327). Of 61 treated patients, 33 (54.1%) had ≥ 30% PSA declines by C4 and did not switch taxane, 15 patients (24.6%) who did not achieve ≥ 30% PSA declines by C4 switched taxane, and 13 patients (21.3%) discontinued therapy before or at C4. Of patients switching taxane, 46.7% subsequently achieved ≥ 50% PSA decrease. In 26 CTC-evaluable patients, taxane-induced decrease in %ARNL (cycle 1 day 1 v cycle 1 day 8) was associated with a higher rate of ≥ 50% PSA decrease at C4 ( P = .009). Median composite progression-free survival was 9.1 months (95% CI, 4.9 to 11.7 months); median overall survival was not reached at 14 months. Common grade 3 or 4 adverse events included fatigue (13.1%) and febrile neutropenia (11.5%). Conclusion The early taxane switch strategy was associated with improved PSA response rates versus TAX327. Taxane-induced shifts in %ARNL may serve as an early biomarker of clinical benefit in patients treated with taxanes
Nomogram-based Prediction of Overall Survival in Patients with Metastatic Urothelial Carcinoma Receiving First-line Platinum-based Chemotherapy: Retrospective International Study of Invasive/Advanced Cancer of the Urothelium (RISC)
The available prognostic models for overall survival (OS) in patients with metastatic urothelial carcinoma (UC) have been derived from clinical trial populations of cisplatin-treated patients
Comparing genotyping algorithms for Illumina's Infinium whole-genome SNP BeadChips
The Brassica napus 60K Illumina Infinium™ SNP array has had huge international uptake in the rapeseed community due to the revolutionary speed of acquisition and ease of analysis of this high-throughput genotyping data, particularly when coupled with the newly available reference genome sequence. However, further utilization of this valuable resource can be optimized by better understanding the promises and pitfalls of SNP arrays. We outline how best to analyze Brassica SNP marker array data for diverse applications, including linkage and association mapping, genetic diversity and genomic introgression studies. We present data on which SNPs are locus-specific in winter, semi-winter and spring B. napus germplasm pools, rather than amplifying both an A-genome and a C-genome locus or multiple loci. Common issues that arise when analyzing array data will be discussed, particularly those unique to SNP markers and how to deal with these for practical applications in Brassica breeding applications
Hospital-level associations with 30-day patient mortality after cardiac surgery: a tutorial on the application and interpretation of marginal and multilevel logistic regression
Background: Marginal and multilevel logistic regression methods can estimate associations between hospital-level factors and patient-level 30-day mortality outcomes after cardiac surgery. However, it is not widely understood how the interpretation of hospital-level effects differs between these methods. Methods. The Australasian Society of Cardiac and Thoracic Surgeons (ASCTS) registry provided data on 32,354 patients undergoing cardiac surgery in 18 hospitals from 2001 to 2009. The logistic regression methods related 30-day mortality after surgery to hospital characteristics with concurrent adjustment for patient characteristics. Results: Hospital-level mortality rates varied from 1.0% to 4.1% of patients. Ordinary, marginal and multilevel regression methods differed with regard to point estimates and conclusions on statistical significance for hospital-level risk factors; ordinary logistic regression giving inappropriately narrow confidence intervals. The median odds ratio, MOR, from the multilevel model was 1.2 whereas ORs for most patient-level characteristics were of greater magnitude suggesting that unexplained between-hospital variation was not as relevant as patient-level characteristics for understanding mortality rates. For hospital-level characteristics in the multilevel model, 80% interval ORs, IOR-80%, supplemented the usual ORs from the logistic regression. The IOR-80% was (0.8 to 1.8) for academic affiliation and (0.6 to 1.3) for the median annual number of cardiac surgery procedures. The width of these intervals reflected the unexplained variation between hospitals in mortality rates; the inclusion of one in each interval suggested an inability to add meaningfully to explaining variation in mortality rates. Conclusions: Marginal and multilevel models take different approaches to account for correlation between patients within hospitals and they lead to different interpretations for hospital-level odds ratios. © 2012 Sanagou et al; licensee BioMed Central Ltd
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