911 research outputs found
Ferromagnetic properties of one-dimensional decamethylferrocenium tetracyanoethylenide (1:1): [Fe(n5-C5Me5)2].+[TCNE].-
Journal Article[Fe(C5Me5)2].+ [TCNE].-- has been characterized by magnetic susceptibility to possess dominant ferromagnetic interactions; its structure has been determined by X-ray crystallography
Quest for a polymeric ferromagnet: a new polymorph of 1,4-bis(2,2,6,6-tetramethyl-4-oxy-4-piperidyl-1-oxy)butadiyne (invited)
Journal ArticleA new polymorph of 1,4-bis(2,2,6,6-tetramethyl-4-oxy-4-piperidyl-l-oxy) butadiyne has been prepared and characterized by x-ray diffraction, infrared and Raman spectroscopies, and magnetic susceptibility. Unlike t h e Pccn-a phase, the B phase belongs to the Pca2y1 space group [a = 14.265(1) A(o),b = 8.079 (3) A(o), and c = 18.865(2) A(o), V = 2174.1 A(o) 3, Z = 4, T = - 100 °C, Ru = 4.8%, Rw = 5.0%) . The C=C, CC-CC, and NO distances are 1.201, 1.391, and 1.293 A., respectively. The only intermolecular interactions a r e 1.844-A(o)-OH... ON hydrogen bonding interactions
Formation of a zwitterionic donor-acceptor compound based on N,N,N',N'-tetramethly-p-phenylenediamine and 7,7,8,8-tetracyanoperfluoro-p-quinodimethane
Journal ArticleThe reaction of the donor N,N,N',N'- tetramethyl-p-phenylenediamine (TMPD) with the acceptor 7,7,8,8-tetracyanoperfluoro-p-quinodimethane (TCNQF4) has led to the isolation of a novel type of zwitterionic donor-acceptor compound whose structure has been determined by X-ray crystallography
Synthesis, Structure, and Reactivity of a Rhenium Oxo-Vinylalkylidene Complex
The reaction of 3 equiv of KOC(CF_3)_2Me with ReOCl_3(PPh_3)_2 in dichloromethane, followed by recrystallization from hexanes/THF, gives ReO[OC(CF_3)_2Me]_3(THF)_2( 1) in 35 7% yield. An
X-ray diffraction study of 1 (monoclinic, P2_1/n, a = 10.010(3) Å, b = 29.247(6) Å, c = 10.800(3) Å, β = 117.09(1)', Z = 4) reveals a facial arrangement of the three alkoxide ligands around the metal center in a distorted octahedron. The ligand environment in 1 is quite crowded, as evidenced by an elongated Re-O bond between rhenium and one of the THF ligands. The reaction of 3,3-diphenylcyclopropene with 1 in dichloromethane gives initially a mixture of two isomeric rhenium oxo-vinylalkylidene complexes, of which the isomer syn,mer-ReO[C(H)-CH=CPh_2] [OC(CF3)2Me]3(THF) (2b) was isolated in 87% yield. An X-ray diffraction study of 2b (triclinic, P1^(bar), a = 10.459(3) Å, b = 10.913(3) Å, c = 21.308(6) Å, α = 91.16(3)°,β = 102.05-(2)°, γ = 117.98(2)°, 2 = 2) supports a pseudooctahedral structure with mutually trans vinylalkylidene and THF ligands. Complex 2b does not react readily with internal or terminal olefins; however, the addition of GaBr_3 (1 equiv) to 2b yields moderately active catalyst(s) that metathesize cis-2-pentene at ~6.7 turnovers min^(-1). No propagating alkylidene species are observed during the metathesis reaction
Synthesis, Structure, and Reactivity of a Rhenium Oxo-Vinylalkylidene Complex
The reaction of 3 equiv of KOC(CF_3)_2Me with ReOCl_3(PPh_3)_2 in dichloromethane, followed by recrystallization from hexanes/THF, gives ReO[OC(CF_3)_2Me]_3(THF)_2( 1) in 35 7% yield. An
X-ray diffraction study of 1 (monoclinic, P2_1/n, a = 10.010(3) Å, b = 29.247(6) Å, c = 10.800(3) Å, β = 117.09(1)', Z = 4) reveals a facial arrangement of the three alkoxide ligands around the metal center in a distorted octahedron. The ligand environment in 1 is quite crowded, as evidenced by an elongated Re-O bond between rhenium and one of the THF ligands. The reaction of 3,3-diphenylcyclopropene with 1 in dichloromethane gives initially a mixture of two isomeric rhenium oxo-vinylalkylidene complexes, of which the isomer syn,mer-ReO[C(H)-CH=CPh_2] [OC(CF3)2Me]3(THF) (2b) was isolated in 87% yield. An X-ray diffraction study of 2b (triclinic, P1^(bar), a = 10.459(3) Å, b = 10.913(3) Å, c = 21.308(6) Å, α = 91.16(3)°,β = 102.05-(2)°, γ = 117.98(2)°, 2 = 2) supports a pseudooctahedral structure with mutually trans vinylalkylidene and THF ligands. Complex 2b does not react readily with internal or terminal olefins; however, the addition of GaBr_3 (1 equiv) to 2b yields moderately active catalyst(s) that metathesize cis-2-pentene at ~6.7 turnovers min^(-1). No propagating alkylidene species are observed during the metathesis reaction
Nonsteroidal antiâ inflammatory drugs (NSAIDs) and paracetamol do not affect 6â month moodâ stabilizing treatment outcome among 482 patients with bipolar disorder
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136478/1/da22601_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136478/2/da22601.pd
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International meta-analysis of PTSD genome-wide association studies identifies sex- and ancestry-specific genetic risk loci.
The risk of posttraumatic stress disorder (PTSD) following trauma is heritable, but robust common variants have yet to be identified. In a multi-ethnic cohort including over 30,000 PTSD cases and 170,000 controls we conduct a genome-wide association study of PTSD. We demonstrate SNP-based heritability estimates of 5-20%, varying by sex. Three genome-wide significant loci are identified, 2 in European and 1 in African-ancestry analyses. Analyses stratified by sex implicate 3 additional loci in men. Along with other novel genes and non-coding RNAs, a Parkinson's disease gene involved in dopamine regulation, PARK2, is associated with PTSD. Finally, we demonstrate that polygenic risk for PTSD is significantly predictive of re-experiencing symptoms in the Million Veteran Program dataset, although specific loci did not replicate. These results demonstrate the role of genetic variation in the biology of risk for PTSD and highlight the necessity of conducting sex-stratified analyses and expanding GWAS beyond European ancestry populations
Patterns of changes in bipolar depressive symptoms revealed by trajectory analysis among 482 patients with bipolar disorder
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/149731/1/bdi12715_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/149731/2/bdi12715.pd
A Comparison of Four Treatments for Generalized Convulsive Status Epilepticus
ABSTRACT
Background and Methods Although generalized convulsive status epilepticus is a life-threatening emergency, the best initial drug treatment is uncertain. We conducted a five-year randomized, doubleblind, multicenter trial of four intravenous regimens: diazepam (0.15 mg per kilogram of body weight) followed by phenytoin (18 mg per kilogram), lorazepam (0.1 mg per kilogram), phenobarbital (15 mg per kilogram), and phenytoin (18 mg per kilogram). Patients were classified as having either overt generalized status epilepticus (defined as easily visible generalized convulsions) or subtle status epilepticus (indicated by coma and ictal discharges on the electroencephalogram, with or without subtle convulsive movements such as rhythmic muscle twitches or tonic eye deviation). Treatment was considered successful when all motor and electroencephalographic seizure activity ceased within 20 minutes after the beginning of the drug infusion and there was no return of seizure activity during the next 40 minutes. Analyses were performed with data on only the 518 patients with verified generalized convulsive status epilepticus as well as with data on all 570 patients who were enrolled.
Results Three hundred eighty-four patients had a verified diagnosis of overt generalized convulsive status epilepticus. In this group, lorazepam was successful in 64.9 percent of those assigned to receive it, phenobarbital in 58.2 percent, diazepam and phenytoin in 55.8 percent, and phenytoin in 43.6 percent (P=0.02 for the overall comparison among the four groups). Lorazepam was significantly superior to phenytoin in a pairwise comparison (P=0.002). Among the 134 patients with a verified diagnosis of subtle generalized convulsive status epilepticus, no significant differences among the treatments were detected (range of success rates, 7.7 to 24.2 percent). In an intention-to-treat analysis, the differences among treatment groups were not significant, either among the patients with overt status epilepticus (P=0.12) or among those with subtle status epilepticus (P=0.91). There were no differences among the treatments with respect to recurrence during the 12- hour study period, the incidence of adverse reactions, or the outcome at 30 days.
Conclusions As initial intravenous treatment for overt generalized convulsive status epilepticus, lorazepam is more effective than phenytoin. Although lorazepam is no more efficacious than phenobarbital or diazepam and phenytoin, it is easier to use. (N Engl J Med 1998;339:792-8.
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