194 research outputs found

    CCSD(T) Study of CD3-O-CD3 and CH3-O-CD3 Far-Infrared Spectra

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    From a vibrationally corrected 3D potential energy surface determined with highly correlated ab initio calculations (CCSD(T)), the lowest vibrational energies of two dimethyl-ether isotopologues, 12CH3–16O–12CD3 (DME-d3) and 12CD3–16O–12CD3 (DME-d6), are computed variationally. The levels that can be populated at very low temperatures correspond to the COC-bending and the two methyl torsional modes. Molecular symmetry groups are used for the classification of levels and torsional splittings. DME-d6 belongs to the G36 group, as the most abundant isotopologue 12CH3–16O–12CH3 (DME-h6), while DME-d3 is a G18 species. Previous assignments of experimental Raman and far-infrared spectra are discussed from an effective Hamiltonian obtained after refining the ab initio parameters. Because a good agreement between calculated and experimental transition frequencies is reached, new assignments are proposed for various combination bands corresponding to the two deuterated isotopologues and for the 020 → 030 transition of DME-d6. Vibrationally corrected potential energy barriers, structural parameters, and anharmonic spectroscopic parameters are provided. For the 3N – 9 neglected vibrational modes, harmonic and anharmonic fundamental frequencies are obtained using second-order perturbation theory by means of CCSD and MP2 force fields. Fermi resonances between the COC-bending and the torsional modes modify DME-d3 intensities and the band positions of the torsional overtones

    Ab initio spectroscopic characterization of the radical CH3_3OCH2_2 at low temperatures

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    Spectroscopic and structural properties of methoxymethyl radical (CH3_3OCH2_2, RDME) are determined using explicitly correlated ab initio methods. This radical of astrophysical and atmospheric relevance has not been fully characterized at low temperatures, which has delayed the astrophysical searches. We provide rovibrational parameters, excitations to the low energy electronic states, torsional and inversion barriers and low vibrational energy levels. In the electronic ground state (X2^2A), which appears "clean" from non-adiabatic effects, the minimum energy structure is an asymmetric geometry which rotational constants and dipole moment have been determined to be A0_0=46718.6745 MHz, B0_0=10748.4182 MHz, and C0_0=9272.5105 MHz, and 1.432 D (μA\mu_A=0.6952 D, μB\mu_B=1.215 D, μC\mu_C=0.3016 D), respectively. A variational procedure has been applied to determine torsion-inversion energy levels. Each level splits into 3 subcomponents (A1_1/A2_2 and E) corresponding to the three methyl torsion minima. Although the potential energy surface presents 12 minima, at low temperatures, the infrared band shapes correspond to a surface with only three minima because the top of the inversion Vα^{\alpha} barrier at α=0{\alpha}=0^{\circ} (109 cm1^{-1}) stands below the zero point vibrational energy and the CH2_2 torsional barrier is relatively high (\sim2000 cm1^{-1}). The methyl torsion barrier was computed to be \sim500 cm1^{-1} and produces a splitting of 0.01 cm1^{-1} of the ground vibrational state

    The Mission Assessment Post Processor (MAPP): A New Tool for Performance Evaluation of Human Lunar Missions

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    The National Aeronautics and Space Administration s (NASA) Constellation Program paves the way for a series of lunar missions leading to a sustained human presence on the Moon. The proposed mission design includes an Earth Departure Stage (EDS), a Crew Exploration Vehicle (Orion) and a lunar lander (Altair) which support the transfer to and from the lunar surface. This report addresses the design, development and implementation of a new mission scan tool called the Mission Assessment Post Processor (MAPP) and its use to provide insight into the integrated (i.e., EDS, Orion, and Altair based) mission cost as a function of various mission parameters and constraints. The Constellation architecture calls for semiannual launches to the Moon and will support a number of missions, beginning with 7-day sortie missions, culminating in a lunar outpost at a specified location. The operational lifetime of the Constellation Program can cover a period of decades over which the Earth-Moon geometry (particularly, the lunar inclination) will go through a complete cycle (i.e., the lunar nodal cycle lasting 18.6 years). This geometry variation, along with other parameters such as flight time, landing site location, and mission related constraints, affect the outbound (Earth to Moon) and inbound (Moon to Earth) translational performance cost. The mission designer must determine the ability of the vehicles to perform lunar missions as a function of this complex set of interdependent parameters. Trade-offs among these parameters provide essential insights for properly assessing the ability of a mission architecture to meet desired goals and objectives. These trades also aid in determining the overall usable propellant required for supporting nominal and off-nominal missions over the entire operational lifetime of the program, thus they support vehicle sizing

    Patients' satisfaction with community treatment: a pilot cross-sectional survey adopting multiple perspectives.

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    ACCESSIBLE SUMMARY: Patients' satisfaction is scarcely studied within the context of community treatment for adolescents. Thus, this study adopts a multiple perspective on patients' satisfaction (including service users as well as staff members). The results highlighted that all informants (patients, foster carers in foster homes and professional caregivers from community treatment teams) perceived the patients to be satisfied, with foster carers reporting the highest patient satisfaction rate. Considering the patient satisfaction rate from multiple perspectives provides complementary understandings. Clinical outcomes and, specifically, a reduction in emotional difficulties were related to patient's satisfaction, but only from the patients' perspective. ABSTRACT: Community treatment (CT) teams in Switzerland provide care to patients who are unable to use regular child and adolescent mental health services (i.e. inpatient and outpatients facilities). No study has considered patients' self-rated satisfaction alongside with staff members' perspectives on patient satisfaction. Thus, adopting a cross-sectional survey design, we collected patients' satisfaction using the Client Satisfaction Questionnaire (CSQ-8), rated by multiple informants (patients, foster carers in foster homes and professional caregivers from CT teams). Professional caregivers assessed clinical outcomes using the Health of the Nation Outcome Scale for Children and Adolescents. The results indicated that all informants were satisfied with the community treatment teams. The satisfaction scores were not correlated across informants; however, the alleviation of emotional symptoms was correlated with patients' satisfaction. This study indicated that the use of a combined approach including the views of service users and professionals gives important complementary information. Finally, in our sample, lower emotional symptoms were linked to enhanced patient satisfaction. This study demonstrated the importance of considering multiple perspectives to obtain the most accurate picture of patients' satisfaction. Second, focusing on the reduction of emotional symptoms might lead to a higher degree of patients' satisfaction

    Highly correlated ab initio

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    Human mesenchymal stem cells growth and osteogenic differentiation on piezoelectric poly(vinylidene fluoride) microsphere substrates

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    The aim of this work was to determine the influence of the biomaterial environment on human mesenchymal stem cell (hMSC) fate when cultured in supports with varying topography. Poly(vinylidene fluoride) (PVDF) culture supports were prepared with structures ranging between 2D and 3D, based on PVDF films on which PVDF microspheres were deposited with varying surface density. Maintenance of multipotentiality when cultured in expansion medium was studied by flow cytometry monitoring the expression of characteristic hMSCs markers, and revealed that cells were losing their characteristic surface markers on these supports. Cell morphology was assessed by scanning electron microscopy (SEM). Alkaline phosphatase activity was also assessed after seven days of culture on expansion medium. On the other hand, osteoblastic differentiation was monitored while culturing in osteogenic medium after cells reached confluence. Osteocalcin immunocytochemistry and alizarin red assays were performed. We show that flow cytometry is a suitable technique for the study of the differentiation of hMSC seeded onto biomaterials, giving a quantitative reliable analysis of hMSC-associated markers. We also show that electrosprayed piezoelectric poly(vinylidene fluoride) is a suitable support for tissue engineering purposes, as hMSCs can proliferate, be viable and undergo osteogenic differentiation when chemically stimulated.The authors thank the Portuguese Foundation for Science and Technology (FCT) for financial support under project PTDC/EEI-SII/5582/2014, Strategic Funding UID/FIS/04650/2013 and grants SFRH/BPD/90870/2012 (C.R.) and SFRH/BPD/121526/2016 (D.M.C). The authors acknowledge funding by the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) and from the Basque Government Industry Department under the ELKARTEK program. JLGR, LC, RSS and AS acknowledge funding by the Conselleria de Educación, Investigación, Cultura y Deporte of the Generalitat Valenciana through PROMETEO/2016/063 project. CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011, Iniciativa Ingenio 2010, Consolider Program, CIBER Actions and financed by the Instituto de Salud Carlos III with assistance from the European Regional Development. This work was partially financed with FEDER funds (CIBERONC (CB16/12/00284)). The authors acknowledge the assistance and advice of Electron Microscopy Service of the UPVinfo:eu-repo/semantics/publishedVersio

    Profiles of Multidrug Resistance Protein-1 in the Peripheral Blood Mononuclear Cells of Patients with Refractory Epilepsy

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    BACKGROUND: About one third of patients with epilepsy become refractory to therapy despite receiving adequate medical treatment, possibly from multidrug resistance. P-glycoprotein, encoded by multidrug resistance protein-1 (MDR1) gene, at the blood brain barrier is considered as a major factor mediating drug efflux and contributing to resistance. Given that peripheral blood mononuclear cells (PBMNCs) express MDR1, we investigated a MDR1 status of PBMNCs in various subsets of epilepsy patients and demonstrated their association with clinical characteristics. METHODOLOGY/PRINCIPAL FINDINGS: Clinical and MDR1 data were collected from 140 patients with epilepsy, 30 healthy volunteers, and 20 control patients taking anti-epileptic drugs. PBMNCs were isolated, and basal MDR1 levels and MDR1 conformational change levels were measured by flow cytometry. MDR1 profiles were analyzed according to various clinical parameters, including seizure frequency and number of medications used in epilepsy patients. Epilepsy patients had a higher basal MDR1 level than non-epilepsy groups (p<0.01). Among epilepsy patients, there is a tendency for higher seizure frequency group to have higher basal MDR1 level (p = 0.059). The MDR1 conformational change level was significantly higher in the high-medication-use group than the low-use group (p = 0.028). Basal MDR1 (OR = 1.16 [95% CI: 1.060-1.268]) and conformational change level (OR = 1.11 [95% CI: 1.02-1.20]) were independent predictors for seizure frequency and number of medications, respectively. CONCLUSIONS/SIGNIFICANCE: The MDR1 profile of PBMNCs is associated with seizure frequency and medication conditions in patients with epilepsy
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