1,357 research outputs found
Phosphine-functionalised tris(pyrazolyl)methane ligands and their mono- and heterobimetallic complexes
Asymmetrically Difunctionalized 1,1′-Ferrocenyl Metalloligands and Their Transition Metal Complexes
FcBipy: Novel redox-active bipyridine ligands based on 1,1′ difunctionalized ferrocenyl backbone, in conjunction with their metal complexes, are reported. The influence of the implemented functional groups on both the iron-centred redox potential and the N,N′-coordinated nickel complexes were confirmed for the reductive elimination reaction of an aryl ether induced by oxidation of the corresponding methoxides
Structural Characterization and Lifetimes of Triple‐Stranded Helical Coinage Metal Complexes: Synthesis, Spectroscopy and Quantum Chemical Calculations
This work reports on a series of polynuclear complexes containing a trinuclear Cu, Ag, or Au core in combination with the fac-isomer of the metalloligand [Ru(pypzH)](PF) (pypzH=3-(pyridin-2-yl)pyrazole). These (in case of the Ag and Au containing species) newly synthesized compounds of the general formula [{Ru(pypz)}M](PF) (2: M=Cu; 3: M=Ag; 4: M=Au) contain triple-stranded helical structures in which two ruthenium moieties are connected by three N-M-N (M=Cu, Ag, Au) bridges. In order to obtain a detailed description of the structure both in the electronic ground and excited states, extensive spectroscopic and quantum chemical calculations are applied. The equilateral coinage metal core triangle in the electronic ground state of 2–4 is distorted in the triplet state. Furthermore, the analyses offer a detailed description of electronic excitations. By using time-resolved IR spectroscopy from the microsecond down to the nanosecond regime, both the vibrational spectra and the lifetime of the lowest lying electronically excited triplet state can be determined. The lifetimes of these almost only non-radiative triplet states of 2–4 show an unusual effect in a way that the Au-containing complex 4 has a lifetime which is by more than a factor of five longer than in case of the Cu complex 2. Thus, the coinage metals have a significant effect on the electronically excited state, which is localized on a pypz ligand coordinated to the Ru atom indicating an unusual cooperative effect between two moieties of the complex
On the accuracy of ion measurements using a neutral cluster and air ion spectrometer
Here, we present a calibration of the Neutral cluster and Air Ion Spectrometer (NAIS, Airel Ltd.) for the size and concentration of ions in the mobility-diameter size-range 0.98-29.1 nm. Previous studies raised accuracy issues in size and concentration determination and highlighted the importance of used data inversion algorithm. Therefore, we investigated the performance of the NAIS by using five inversion methods. The presented results illustrate that the size information given by the NAIS is very accurate, regardless of the version of the data inversion. The number concentrations determined by the NAIS were 15%-30% too low especially at the lower end of the measurement size range (<5 nm), whereas concentrations at diameters 19.6 nm and larger were overestimated by up to 8%. With the correction presented in this study, the uncertainty of the ion concentration measurement of the NAIS can be reduced to less than 10%, allowing the NAIS to be used in quantitative ion cluster studies and more accurate determination of formation and growth rates.Peer reviewe
Redox-responsive phosphonite gold complexes in hydroamination catalysis
Very high activities were observed in the redox-induced hydroamination of alkynes by employing a redox-active gold(I) complexfeaturingan electron-deficient, terphenyl-substituted phosphonite-based ligand. The hydroamination proceeds roughly two-fold faster with the in situ oxidized catalysts than with their reduced form
Psychometric Evaluation and Design of Patient-Centered Communication Measures for Cancer Care Settings
Objective
To evaluate the psychometric properties of questions that assess patient perceptions of patient-provider communication and design measures of patient-centered communication (PCC). Methods
Participants (adults with colon or rectal cancer living in North Carolina) completed a survey at 2 to 3 months post-diagnosis. The survey included 87 questions in six PCC Functions: Exchanging Information, Fostering Health Relationships, Making Decisions, Responding to Emotions, Enabling Patient Self-Management, and Managing Uncertainty. For each Function we conducted factor analyses, item response theory modeling, and tests for differential item functioning, and assessed reliability and construct validity. Results
Participants included 501 respondents; 46% had a high school education or less. Reliability within each Function ranged from 0.90 to 0.96. The PCC-Ca-36 (36-question survey; reliability=0.94) and PCC-Ca-6 (6-question survey; reliability=0.92) measures differentiated between individuals with poor and good health (i.e., known-groups validity) and were highly correlated with the HINTS communication scale (i.e., convergent validity). Conclusion
This study provides theory-grounded PCC measures found to be reliable and valid in colorectal cancer patients in North Carolina. Future work should evaluate measure validity over time and in other cancer populations. Practice implications
The PCC-Ca-36 and PCC-Ca-6 measures may be used for surveillance, intervention research, and quality improvement initiatives
rapid and robust cd4 and cd8 t nk b cell dendritic cell and monocyte reconstitution after nicotinamide expanded cord blood transplantation
Introduction Nicotinamide-expanded cord blood (NiCord) is a potential alternative source for allogeneic hematopoietic cell transplantation (HCT) when an HLA-id donor is lacking. A phase 1/2 trial with standalone NiCord HCT showed rapid neutrophil- (11 days) and platelet engraftment (34 days). We previously reported that successful CD4+ immune reconstitution (IR) is crucial for infectious and relapse control associated with favorable survival (JACI 2017) and is a better predictor for event-free survival than neutrophil reconstitution. We performed unique in-depth immune monitoring to evaluate and compare IR after NiCord and conventional HCT. Methods In this phase1/2 international multicenter trial, we compared IR after NiCord HCT to cohorts of adolescent and young adult (AYA) patients receiving either unmanipulated cord blood transplantation (unCBT) or T-repleted-unrelated bone marrow transplantation (BMT). All patients received HCT for a hematologic malignancy with myeloablative conditioning without serotherapy. Immune monitoring was performed (harmonized sampling, handling and analyses) in a central lab. The primary endpoint was probability of achieving CD4+ IR (>50*106/L within 100 days). Secondary endpoints were IR of B-cells, CD4+ and CD8+ T-cells, natural killer (NK)-cells, monocytes, and dendritic cells (DC) 7-365 days after HCT. In addition, TREC analyses were performed on CD3+ MACs-sorted cells. Linear-mixed effects modelling in LOESS-regression curves and two-sided log-rank test for univariate comparisons in cumulative incidence plots were used. Results 27 NiCord recipients (median 41.5; 13.4-61.7yrs) were included. NiCord cell dose consisted of median 6.4*106 CD34+/kg, and 2.3*106 CD3+T-cells/kg of the co-infused negative fraction (following CD133+ selection). Of these patients, 91% achieved successful CD4+ IR, which was comparable (p=0.76, Figure 1) to the 27 unCBT (median 15.4; 12.2-22.1 yrs) and 20 BMT (median 14.3; 12.1-19.7 yrs) recipients included in this study. We observed similar reconstitution of T-cells (p=0.15), monocytes (p=0.94), conventional DCs (p=0.41), and plasmacytoid DCs (p=0.52). Interestingly, reconstitution of NK-cells (p Conclusions In-depth immune monitoring reveals fast and full IR after NiCord HCT in adult patients, which is equal or even faster to IR after unCBT or BMT, despite the younger age of the AYA cohorts (expected to reconstitute faster). This may be explained by the higher stem cell dose and higher proliferative capacity of the NiCord-expanded product. Optimal comparison of IR in NiCord vs. unCBT in a randomized phase 3 trial is underway
A mathematical model for breath gas analysis of volatile organic compounds with special emphasis on acetone
Recommended standardized procedures for determining exhaled lower respiratory
nitric oxide and nasal nitric oxide have been developed by task forces of the
European Respiratory Society and the American Thoracic Society. These
recommendations have paved the way for the measurement of nitric oxide to
become a diagnostic tool for specific clinical applications. It would be
desirable to develop similar guidelines for the sampling of other trace gases
in exhaled breath, especially volatile organic compounds (VOCs) which reflect
ongoing metabolism. The concentrations of water-soluble, blood-borne substances
in exhaled breath are influenced by: (i) breathing patterns affecting gas
exchange in the conducting airways; (ii) the concentrations in the
tracheo-bronchial lining fluid; (iii) the alveolar and systemic concentrations
of the compound. The classical Farhi equation takes only the alveolar
concentrations into account. Real-time measurements of acetone in end-tidal
breath under an ergometer challenge show characteristics which cannot be
explained within the Farhi setting. Here we develop a compartment model that
reliably captures these profiles and is capable of relating breath to the
systemic concentrations of acetone. By comparison with experimental data it is
inferred that the major part of variability in breath acetone concentrations
(e.g., in response to moderate exercise or altered breathing patterns) can be
attributed to airway gas exchange, with minimal changes of the underlying blood
and tissue concentrations. Moreover, it is deduced that measured end-tidal
breath concentrations of acetone determined during resting conditions and free
breathing will be rather poor indicators for endogenous levels. Particularly,
the current formulation includes the classical Farhi and the Scheid series
inhomogeneity model as special limiting cases.Comment: 38 page
nicord single unit expanded umbilical cord blood transplantation ucbt final results of a multicenter phase i ii trial
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The First VERITAS Telescope
The first atmospheric Cherenkov telescope of VERITAS (the Very Energetic
Radiation Imaging Telescope Array System) has been in operation since February
2005. We present here a technical description of the instrument and a summary
of its performance. The calibration methods are described, along with the
results of Monte Carlo simulations of the telescope and comparisons between
real and simulated data. The analysis of TeV -ray observations of the
Crab Nebula, including the reconstructed energy spectrum, is shown to give
results consistent with earlier measurements. The telescope is operating as
expected and has met or exceeded all design specifications.Comment: Accepted by Astroparticle Physic
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