1,031 research outputs found
Robust High-Dynamic-Range Vector Magnetometry via Nitrogen-Vacancy Centers in Diamond
We demonstrate a robust, scale-factor-free vector magnetometer, which uses a
closed-loop frequency-locking scheme to simultaneously track Zeeman-split
resonance pairs of nitrogen-vacancy (NV) centers in diamond. Compared with
open-loop methodologies, this technique is robust against fluctuations in
temperature, resonance linewidth, and contrast; offers a
three-order-of-magnitude increase in dynamic range; and allows for simultaneous
interrogation of multiple transition frequencies. By directly detecting the
resonance frequencies of NV centers aligned along each of the diamond's four
tetrahedral crystallographic axes, we perform full vector reconstruction of an
applied magnetic field
Modulation of type IV collagenase and plasminogen activator in a hamster fibrosarcoma by basement membrane components and lung fibroblasts.
The effect of basement membrane components (laminin, fibronectin and type IV collagen) and lung fibroblasts on type IV collagenase and plasminogen activator activity was investigated in a primary HSV-2-induced hamster fibrosarcoma, and its in vivo derived sublines and in vitro derived clones of varying metastatic potential. Fibronectin and type IV collagen were ineffective at influencing the expression of either type IV collagenase or plasminogen activator activity. Laminin, however, at concentrations of 1-10 micrograms ml-1 added to the serum-free culture supernatants, increased the release of type IV collagenase by up to 100% for the parental cell line. Three highly metastatic sublines (two from in vivo origin and one from in vitro cloning) showed increases of up to 300%. Non-metastatic sublines (two from in vivo origin and one from in vitro cloning), however, showed no increase in type IV collagenase activity. Plasminogen activator release from either the parental line cell or its metastatic sublines and clones, was unaffected by the addition of laminin. Addition of tumour cells to lung fibroblast monolayers resulted in an increased expression of PA activity in the supernatant, whilst type IV collagenase activity was reduced
Validation of the Italian version of the Patient Reported Experience Measures for intermediate care services
Background: Intermediate care (IC) services are a key component of integrated care for elderly people, providing a link between hospital and home through provision of rehabilitation and health and social care. The Patient Reported Experience Measures (PREMs) are designed to measure user experience of care in IC settings. Objective: To examine the feasibility and the scaling properties of the Italian version of PREMs questionnaires for use in IC services. Methods: A cross-sectional survey was conducted on consecutive users of 1 home-based and 4 bed-based IC services in Emilia-Romagna (Italy). The main outcome measure was the PREMs questionnaire results. PREMs for each home- and bed-based IC services were translated, back-translated, and adapted through consensus among the members of the advisory board and pilot testing of face validity in 15 patients. A total of 199 questionnaires were returned from users of bed-based services and 185 were returned by mail from users of home-based services. The return rates and responses were examined. Mokken analysis was used to examine the scaling properties of the PREMs. Results: Analysis performed on the bed-based PREMs (N=154) revealed that 13 items measured the same construct and formed a moderate-strength scale (Loevinger H=0.488) with good reliability (Cronbach’s alpha =0.843). Analysis of home-based PREMs (N=134 records) revealed that 15 items constituted a strong scale (Loevinger H=0.543) with good reliability (Cronbach’s alpha =0.875). Conclusion: The Italian versions of the bed- and home-based IC-PREMs questionnaires proved to be valid and reliable tools to assess patients’ experience of care. Future plans include monitoring user experience over time in the same facilities and in other Italian IC settings for between-service benchmarking
PHYCOBILISOMES AND ISOLATED PHYCOBILIPROTEINS. EFFECT OF GLUTARDIALDEHYDE AND BENZOQUINONE ON FLUORESCENCE
The fluorescence of the biliproteins C-phycocyanin from Spirulina platensis, B-phycoerythrin
from Porphyridium cruentum and of isolated whole P. cruentum phycobilisomes is quenched in the
presence of glutardialdehyde (GA) or benzoquinone (BQ). The kinetics of fluorescence decrease thus
induced is biphasic. If GA is used as a quencher, the fluorescence can be recovered at 77 K. Contrary to
the GA-effect, only a minor recovery takes place with BQ at 77K, thus demonstrating a different
mechanism of action of GA and BQ on biliprotein
Young children's cognitive achievement: home learning environment, language and ethnic background
For decades, research has shown differences in cognitive assessment scores between White and minority ethnic group(s) learners as well as differences across different minority ethnic groups. More recent data have indicated that the home learning environment and languages spoken can impact cognitive assessment and other corollary outcomes. This study uses the Millennium Cohort Study to jointly assess how minority ethnic group, home learning environment and home languages predict child cognitive assessment scores. Regression analyses were conducted using two assessment measures. The following is hypothesised: (1) cognitive achievement scores vary by minority ethnic group, (2) more home learning environment in early childhood leads to higher cognitive development scores and (3) English only in the home yields the highest cognitive scores while no English in the home yields the lowest. Findings reveal that there are differences in cognitive scores along ethnic group categories although there are also some unexpected findings. Home learning environment does not play as large a role as was predicted in raising the assessment scores overall for learners while speaking English in the home does, irrespective of ethnic background
Geographic Variation in Response of Pine Engraver, Ips pini, and Associated Species to Pheromone, Lanierone
THERMAL DENATURATION OF MONOMERIC AND TRIMERIC PHYCOCYANINS STUDIED BY STATIC AND SPECTROSCOPY POLARIZED TIME-RESOLVED FLUORESCENCE
C-Phycocyanin (PC) and allophycocyanin (APC). as well as the a-subunit of PC. have been
isolated from the blue-green alga (cyanobacterium). Spirulina platensis. The effects of partial thermal
denaturation of PC and of its state of aggregation have been studied by ps time-resolved, polarized
fluorescence spectroscopy. All measurements have been performed under low photon fluxes (< 10’ ’
photonsipulse x cm’) to minimize singlet-singlet annihilation processes. A complex decay is obtained
under most conditions, which can be fitted satisfactorily with a bi-exponential (7’ = 70400 ps. T? =
1000-3000 ps) for both the isotropic and the polarized part, but with different intensities and time
constants for the two decay curves. The data are interpreted in the frameworkof the model first developed
by Teak and Dale (Biochern. J. 116, 161 (1970)], which divides the spectroscopically different
chromophores in (predominantly) sensitizing (s) and fluorescing U, ones. If one assumes temperature
dependent losses in the energy transfer from the s to the f and between f chromophores. both the
biexponential nature of the isotropic fluorescence decay and the polarization data can be rationalized. In
the isotropic emission (corresponding to the population of excited states) the short lifetime is related to the
s-,f transfer. the longer one to the “free“ decay of the final acceptor(s) (= f). The polarized part is
dominated by an extremely short decay time. which is related to s+f transfer, as well as to resonance
transfer between the f-chromophores
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