562 research outputs found
POLARIZED REFLECTION, ZEEMAN, AND MCD STUDIES OF CRYSTALLINE PORPHYRINS
No full textAuthor Institution: Radiation Laboratory and Department of Chemistry, University of Notre Dame Notre DameSpectroscopic studies on the absorption bands of nickel octaethylporphyrin (NiOEP) crystals are reported and interpreted. These include polarized reflection spectra of oriented single crystals; circular polarized Zeeman, and MCD spectra of polycrystalline samples. Two Davydov or factor groupd components are assigned. The higher energy component is parity forbidden but vibronically coupled to the lower one. MCD, Zeeman and zero-field data determine the symmetry of the vibration and the value of the coupling coefficient. An estimate for the effective orbital angular momentum coupling parameter is calculated from the MCD data
MAGNETIC CIRCULAR DICHROISM (MCD) STUDIES OF MATRIX ISOLATED LITHIUM ATOMS
No full textAuthor Institution:This work reports a series of MCD (and absorption) studies of the transition of Li atoms matrix isolated in Ar, Kr and Ke matrices. The MCD signals were extraordinarily large and showed a strong temperature dependence. The transition is remarkably well resolved into the usual ``triplet’‘ structure. A detailed analysis suggests that we can reproduce the observed data assuming a tetragonal or trigonal site splitting and an effective excited state spin-orbit coupling constant of the order of negative 10^{2} \mbox{cm}^{-1}. The sign and magnitude of this quantity clearly reflect the interaction of the Li atom with neighboring host atoms. It was also found that the spectrum changed significantly under the influence of the scanning radiation due to the high mobility of the Li atoms. The MCD spectrometer was modified so that the MCD and absorption spectrum could be recorded simultaneously at high sensitivity. A brief description of the experimental arrangement will be presented
MCD SPECTRA OF METHYL IODIDE AND HYDROGEN IODIDE IN THE VACUUM ULTRAVIOLET
No full textAuthor Institution: Department of Chemistry, Louisiana State UniversityThe gas-phase magnetic circular dichroism (MCD) spectra of methyl iodide and hydrogen iodide will be reported for the spectral region ca. 1500-2000 {\AA}. Of specific interest are the absorption bands assigned to members of the first s-Rydberg spin-orbit manifold. The differences in the magnetic properties of these spin-orbit members can be observed in their MCD spectra and, therefore, a unique insight into their characterization is provided. The validity of existing assignments will be discussed
STATE OF BENZENE AND DERIVATIVES--MCD SPECTRA AND MAGNETIC MOMENTS
No full textAuthor Institution: Department of Chemistry, University of Southern CaliforniaThe magnetic circular dichroism (MCD) spectra of the transition of benzene and its methyl derivatives have been measured in the gas-phase and in solution. From these data, the magnetic moments of the state in these compounds are obtained. The magnetic moments in solution decrease with increase in methyl substitution. In the gas-phase, Rydberg transitions contribute to the MCD and in some cases prevent the determination of the magnetic moment
Matrine protects against MCD-induced development of NASH via upregulating Hsp72 and downregulating mTOR in a manner distinctive from metformin
No full textThe use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms. The present study investigated the effects of matrine on non-alcoholic steatohepatitis (NASH) in mice induced by a methionine choline-deficient (MCD) diet and the mechanism involved. The study was performed in C57B/6J mice fed a MCD diet for 6 weeks to induce NASH with or without the treatment of matrine (100 mg/kg/day in diet). Metformin was used (250 mg/kg/day in diet) as a comparator for mechanistic investigation. Administration of matrine significantly reduced MCD-induced elevations in plasma ALT and AST but without changing body or liver fat content. Along with alleviating liver injury, matrine suppressed MCD-induced hepatic inflammation (indicated by TNFα, CD68, MCP-1, and NLRP3) and fibrosis (indicated by collagen 1, TGFβ, Smad3, and sirius-red staining). In comparison, metformin treatment did not show any clear sign of effects on these parameters indicative of NASH. Further examination of the liver showed that matrine treatment rescued the suppressed HSP72 (a chaperon protein against cytotoxicity) and blocked the induction of mTOR (a key protein in a stress pathway). In keeping with the lack of the improvement of the NASH features, metformin did not show any significant effect against MCD-induced changes in HSP72 and mTOR. Matrine protects against MCD-induced development of NASH which is refractory to metformin treatment. Its anti-NASH effects involve enhancing HSP72 and downregulating mTOR but do not rely on amelioration of hepatos
An Efficient MCD-OSVM Model for Outlier Detection in IoT-Based Smart Energy Management Systems
No full textAs Information, Communication, and Sensor Technologies (ICST) continue to evolve, data-driven innovations like the Internet of Things (IoT) and Smart Technologies, including Smart Energy Management Systems (SEMS), have become increasingly prevalent worldwide. Ensuring data quality is crucial for the effective implementation of IoT-based SEMS, as poor data management in these critical systems can significantly impact the quality of life for millions and potentially lead to severe disruptions and damage at a national level. In this research, an efficient One-class Support Vector Machine (OSVM) model is developed by deploying the Minimum Covariance Determinant (MCD) model at the data pre-processing phase to clean the training data This allow a better trained OSVM model that can be used for the outlier detection. The comparison between the efficient MCD-OSVM model and the base OSVM model, both based on the same original model, highlights a key difference in the training phase: the proposed model was trained with cleaned data using the MCD method, while the base OSVM model used the original, uncleaned data. Cleaning the dataset with an efficient method such as MCD improves the accuracy of OSVM model, an increase of 13.21% in average accuracy, while only increase the operation time 9.5 seconds, although the overall operation time can be further reduced as it is also found a cleaner training dataset will indirectly improve the execution time of OSVM models by allowing it to run on a lower NU parameter value.© 2024 The author(s). This is an open access article under the CC BY-NC-SA 4.0 license.fi=vertaisarvioitu|en=peerReviewed
Radiographic, computed tomographic, and arthroscopic diagnosis of radioulnar incongruence in dogs with medial coronoid disease
No full textObjective
To characterize radioulnar incongruence (RUI) in large dogs with medial coronoid disease (MCD) and determine the agreement between radiography, computed tomography (CT), and arthroscopy.
Study design
Prospective observational case series.
Animals
Twenty-four large-breed dogs under 3 years of age with confirmed MCD.
Methods
MCD and incongruence were evaluated by radiographs and CT. RUI was measured along the ulnar commissure, mid-body, and apex of the medial coronoid process (MCP) by CT and arthroscopy. Joints with RUI ≥ 2 mm were considered incongruent. Variables recorded during arthroscopic treatment included type of MCD, RUI, and modified Outerbridge score. Agreement between the 3 diagnostic imaging techniques was evaluated, and the association between RUI and cartilage damage was analyzed.
Results
Single fragmentation was the most common MCD according to CT and arthroscopy. RUI was associated with degenerative joint disease according to CT and with cartilage damage according to arthroscopy. RUI was diagnosed in 26% of elbows by radiography, in 35% of elbows by CT, in 78% of elbows according to CT measurements of RUI ≥ 2 mm, and in 57% of joints by arthroscopy. RUI was most commonly detected at the ulnar commissure with CT and at the apex of the MCP with arthroscopy. Imaging modalities were in poor to fair agreement with arthroscopy when evaluating RUI.
Conclusion
CT and arthroscopy provided similar detection of MCD and cartilage disease but disagreed in the assessment and localization of RUI.
Clinical significance
CT does not reliably predict arthroscopic assessment of RUI and associated treatment decisions for MCD
Open charm production from d+Au collisions in STAR
No full textCharmed hadrons are interesting observables in heavy ion collisions. They are becoming more accessible to experimental scrutiny at RHIC energies due to the increased production cross-section of charm with the larger centre-of-mass energy available at RHIC compared to SPS. One source of interest in charm production is due to the fact that gluon fusion dominates the charm production cross-section at high energy. Hence, a measurement of charm hadrons is directly sensitive to the gluon distributions of the colliding particles. In addition, any measurement of production at RHIC, and more importantly any observed suppression, must be compared to the overall production of pairs. A systematic study of charmed hadrons in all collision systems available at RHIC is therefore an invaluable experimental tool in the characterization of the matter produced at RHIC. In particular, d + Au collisions are a necessary step for the comparison of any possible modification of charm production in Au + Au collisions. We present preliminary results on D meson production from d + Au collisions in STAR at = 200
Quantification of humeroulnar incongruity in Labrador Retrievers with and without medial coronoid disease
No full textObjective
To quantify humeroulnar incongruity on elbow radiographs in Labrador Retrievers with or without medial coronoid disease (MCD).
Study Design
Retrospective study of 92 elbows.
Sample Population
Radiographic projections of elbow joints from Labrador Retrievers with MCD (n = 42 elbows; 26 dogs) and without MCD (n = 50 elbows; 25 dogs).
Procedure
The congruity of the humeroulnar joint was measured using an index of subluxation (SI) for each elbow. SI was defined as the distance between the centers of 2 circles drawn along the margins of the incisura trochlearis and the trochlea of humerus on mediolateral digital radiographic projections, normalized by the radius of the circle circumscribing the humeral trochlea. SI was compared between right and left elbows with and without pathology using a Wilcoxon test for paired data, and between normal and abnormal groups with a Wilcoxon test for unpaired data. Mismatch between ulnar curvature and curvature of humeral trochlea and radioulnar incongruency were also noted (Wilcoxon test). The intraobserver repeatability, correlation between SI and radioulnar incongruency, and between SI and mismatch elbow curvature were estimated with a Pearson's correlation coefficient.
Results
Intraobserver repeatability of SI measurement was high (r = 0.97). Mean ± SD humeroulnar incongruity (SI) was greater in elbows with MCD (18.5 ± 6.6) than in the normal elbows (1.7 ± 2.0, P < 0.001). The difference between the diameters of the curvatures of the ulnar and humeral trochlea was greater in elbows with MCD (12.5 ± 4.4) than in the normal group (10.7 ± 4.1, P < 0.05). A moderate correlation was found between the degree of humeroulnar incongruity and a radioulnar step (r = 0.63); however, no correlation was identified between SI and the difference between the diameters of the curvatures of the ulnar and humeral trochleae (r = 0.14).
Conclusion
We propose a radiographic index to measure humeroulnar incongruity on mediolateral digital radiographic projections. This index (SI) supports the presence of humeroulnar incongruity in Labrador Retrievers with MCD. Further evaluation of its reproducibility and clinical importance are warranted. Although there is a moderate correlation between humeroulnar incongruity and radioulnar incongruency, causation has not been established
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