190 research outputs found
Comparison of selected methods for the retrieval of neologisms
The paper discusses and compares several semi-automatic methods used to extract neologisms from linguistic corpora. All the methods are based on the concept of discriminants, or textual features (both lexis and punctuation), that either precede (lexical discriminants) or confine (punctuation discriminants) phrases in which the occurrence of neologisms is higher than elsewhere in the text. Excerption and comparison was conducted on a corpus of 45 million words, articles from Nature scientific magazine. The putative neologisms were extracted using morphological analysis and frequency of their occurrence in the Google search engine. The result is a list of 1000 neologisms and assessment of the efficacy of each method. The paper discusses and compares several semi-automatic methods used to extract neologisms from linguistic corpora. All the methods are based on the concept of discriminants, or textual features (both lexis and punctuation), that either precede (lexical discriminants) or confine (punctuation discriminants) phrases in which the occurrence of neologisms is higher than elsewhere in the text. Excerption and comparison was conducted on a corpus of 45 million words, articles from Nature scientific magazine. The putative neologisms were extracted using morphological analysis and frequency of their occurrence in the Google search engine. The result is a list of 1000 neologisms and assessment of the efficacy of each method
Metal-promoted synthesis and characterization of Pr(III), Nd(III) and Eu(III) Schiff base complexes derived from salicylaldehyde and 4,9-dioxa-1,12- diaminododecane
The one-step metal template reaction of salicylaldehyde with 4,9-dioxa-1,12-diaminododecane in the presence of praseodymium(III), neodymium(III) or europium(III) nitrates gives complexes containing N,N’- bis(salicylidene)-1,12-diamino-4.9-dioxadodecane ligand with N2O4 set of donor atoms as a result of the [2+1] Schiff base condensation. The template reaction products were characterized by spectroscopic (IR, UV-Vis, ESI-MS) and analytical (elemental and thermogravimetric analysis) methods. All data indicate 1:1 ligand to metal stoichiometry
Late Gadolinium Enhancement by Cardiac Magnetic Resonance Imaging and Major Adverse Coronary Events
Background: Coronary artery disease is the most common type of heart disease. CAD encompasses atherosclerosis and arteriosclerosis and is the leading cause of death in the United States in both men and women. This disease process involves the blood vessels responsible for supplying blood to the heart. Arteriosclerosis is described as a hardening of the vessels, while atherosclerosis is the obstruction of vessels due to genetics and dietary/lifestyle activities. In the long-term, these abnormalities can lead to myocardial infarction (MI), valvular heart disease, chest pain or angina, and heart failure.
Standard practice of care currently involves the use electrocardiogram (ECG), computed tomography (CT), and echocardiogram in order to monitor cardiac function. A new emerging imaging study, cardiac magnetic resonance with late gadolinium enhancement, has shown to be a promising prognostic tool in evaluating patient’s risks for major adverse coronary events (MACE).
CMR is a medical imaging technology for non-invasive assessment for the function and structure of the heart. Gadolinium is a contrast agent that can be injected during the CMR study that localizes in cardiac cicatrix tissue. If the imaging study has a positive result, it may lend evidence that cardiac function is below optimal and may put patient at risk for MACE in the future.
Methods: An exhaustive search of available medical literature was performed using the following databases: MEDLINE-OVID, MEDLINE-Pubmed, and CINAHL-EBSCO Host. Articles were discovered using the following terms: MRI, Coronary heart disease, gadolinium, LGE, and cicatrix. Relevant articles were assessed for quality using GRADE.
Results: Three studies met the inclusion criteria and were included in this systematic review. All three of these cohort studies demonstrated that the presence of scar tissue, identified by late gadolinium enhancement (LGE), had a positive predictive value of major adverse cardiac events (MACE) in patients with symptoms or signs suspicious of coronary artery disease (CAD). Studies demonstrated hazard ratios for MACE in LGE positive patients ranging from 4.69 to 11.48.
Conclusion: The use of late gadolinium enhancement as an adjunct to cardiac magnetic resonance (CMR) testing has shown to be a valuable asset in predicting major adverse coronary events such as myocardial infarction and cardiac death. These events were followed for an accumulative median of 19 months, spanning from 6 months to 4.7 years. From the high-quality evidence gathered, LGE was a strong predictor of MACE and may have an invaluable future in stratifying risk among patient populations with clinical CAD.
Keywords: MRI, coronary heart disease, gadolinium, and cicatrix
2,4-Diamino-6-methyl-1,3,5-triazine methanol solvate
The crystal structure of the title compound, C4H7N5·CH4O, is determined by an extensive network of hydrogen bonding. A sequence of centrosymmetric dimeric associations, formed by two different N—H(amino)⋯N(ring) hydrogen bonds, connects the triazine rings into a planar molecular tape. The methanol solvent molecules act as di-acceptors and mono-donors of hydrogen bonds and interlink, almost perpendicularly, the hydrogen-bonded tapes into a three-dimensional structure
Bis(pyridinium) trans-tetrachloridodioxidouranate(VI) dioxane solvate
In the crystal structure of the title compound, (C5H6N)2[UCl4O2]·C4H8O2, the pyridinium cations occupy general positions and the anions and the solvent dioxane molecule are located on centres of inversion. The dioxane molecules are connected to two symmetry-related pyridinium cations via O—H⋯O hydrogen bonding. There are additional intermolecular C—H⋯Cl contacts, which are indicative of weak C—H⋯Cl interactions
Chlorido[2,15-dimethyl-3,7,10,14,20-pentaazabicyclo[14.3.1]eicosa-1(20),2,14,16,18-pentaene]manganese(II) perchlorate acetonitrile solvate
The Mn ion in the title complex, [MnCl(C17H27N5)]ClO4·CH3CN, is six-coordinated with a geometry intermediate between pentagonal pyramidal and heavily distorted octahedral. In the macrocycle, the pyridinium ring makes a large dihedral angle of 63.70 (9)° with the best plane through the remaining four N atoms. This feature is common for 17-membered N5 rings, in contrast to their 16- and 15-membered analogues which often form planar N5 systems. In the crystal, N—H⋯O and C—H⋯O interactions help to establish the packing. The perchlorate counter-ion is rotationally disordered around the chlorine centre, with occupation factors of 0.74 (1) and 0.26 (1)
Disordered structure of propane-1,2-diaminium dichloride
In the title compound, C3H12N2
2+·2Cl−, the cations are disordered over two well resolved positions in a 0.525 (13):0.475 (13) ratio. The disorder involves two C atoms which assume positions that make an almost mirror-symmetrical system. Similar disorder is observed both at room temperature and at 120 (1) K. The conformation of the NCCN chain in both components is close to trans (the torsion angles ca ±170°), while that of CCCN chain is close to gauche (±50°). In the crystal, a network of relatively strong N—H⋯Cl hydrogen bonds connects the cations and anions into one-cation-deep layers parallel to (001); there are R
2
4(8) and R
2
4(11) ring motifs within the plane. The planes are only loosely connected by van der Waals contacts and electrostatic interactions between cations and anions
cis-2,6-Dibenzylcyclohexanone
In the title compound, C20H22O, the molecule is a meso isomer with the two benzyl groups cis to each other. The central cyclohexanone ring adopts a chair conformation. The molecule lies on a noncrystallographic mirror plane and the dihedral angles of the benzyl groups with respect to the ketone moiety are 88.06 (6) and 89.07 (6)°
2-Acetylpyridinium 3-amino-2-chloropyridinium tetrachloridocobaltate(II)
In the title complex, (C5H6ClN2)(C7H8NO)[CoCl4], the CoII ions are tetrahedrally coordinated. The crystal structure is built from hydrogen-bonded centrosymmetric tetramers of tetrachloridocobaltate(II) dianions and 3-amino-2-chloropyridinium cations, additionally strengthened by significant π–π stacking of pyridinium rings [interplanar distance 3.389 (3) Å]. The tetramers are linked by N—H⋯Cl hydrogen bonds into chains; the second kind of cations, viz. 2-acetylpyridinium, are connected by N—H⋯Cl hydrogen bonds to both sides of the chain. The Co—Cl bond lengths in the dianion correlate with the number of hydrogen bonds accepted by the Cl atom. An intramolecular C—H⋯Cl interaction is also present
N-[2-(Acetamido)ethyl]-2-hydroxybenzamide
In the title molecule, C11H14N2O3, an intramolecular O—H⋯O hydrogen bond closes an almost planar [maximum deviation = 0.022 (13) Å] six-membered ring and enforces the cis conformation of the keto group with respect to the hydroxy substituent. In the crystal, intermolecular N—H⋯O hydrogen bonds link the moleclues into ribbons extended along [10]. Weak intermolecular C—H⋯O interactions further consolidate the crystal packing
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