169 research outputs found
A half-century of metal and metalloid-containing polymers
No full textAlaa S. Abd-El-Aziz ... [et al.]; Includes bibliographical references and indexes.; Editor, Alaa S. Abd-El-Aziz, is currently President of the University of Prince Edward Island.Source type: Electronic(1
Effectiveness of Beta-Blockers in Reducing Mortality and Recurrence After Myocardial Infarction: A Systematic Review of Contemporary and Foundational Evidence.
No full textBeta-blockers have traditionally been a mainstay in the management of patients recovering from myocardial infarction (MI). However, their role in the era of modern cardiac interventions remains a topic of active discussion. This systematic review evaluated evidence from 1983 to 2014, drawn from PubMed, Embase, Scopus, and CENTRAL, on the effectiveness of beta-blockers in reducing mortality and recurrent cardiovascular events in adults following MI. After a comprehensive screening process, four eligible studies (two randomized controlled trials, one post hoc analysis, and one observational study) were included, encompassing a total of 19,078 participants with varied clinical settings and patient profiles. Across these studies, beta-blocker therapy was consistently associated with reductions in all-cause mortality, cardiovascular mortality, and recurrent MI, particularly among individuals with reduced left ventricular function. Some benefit was also observed in those with preserved function, though with less consistency. The magnitude of benefit included a 23-26% reduction in overall mortality and up to a 41% reduction in recurrent MI. Despite differences in study design, patient characteristics, and treatment protocols, the overall findings support the continued use of beta-blockers in post-infarction care. Limitations included heterogeneity in populations, beta-blocker regimens, and study eras, highlighting the need for individualized treatment approaches. Nonetheless, these results align with current guidelines from the American College of Cardiology/American Heart Association and the European Society of Cardiology, reaffirming the relevance of beta-blockers in improving outcomes in this patient population
R02. HIV-1 Tat Promotes Age-Related Anxiety-like, Antinociceptive, and Neuromuscular Impairments in Aged Male Mice
No full textCorresponding author (BioMolecular Sciences): Alaa Qrareya, [email protected]://egrove.olemiss.edu/pharm_annual_posters/1001/thumbnail.jp
Properties of the [M(dppm)2M']2+ building blocks (M, M' = Pd or Pt): site selectivity, emission features, and frontier orbital analysis.
No full textThe homodinuclear [ClM(μ-dppm)2MCl] complexes 1 (M = Pd) and 2 (M = Pt) react with RNC ligands (R = Ph, xylyl, p-tolyl, p-C6H4iPr) to provide the A-frame [ClPd(μ-dppm)2(μ-C:N-R)PdCl] (R = Ph (5a), xylyl (5b)), [ClPt(μ-dppm)2(μ-C:N-R)PtCl] (R = p-tolyl (4a); p-C6H4iPr (4b)), and the d9-d9 M2-bonded [ClPt(μ-dppm)2Pt(CN-R)]Cl (R = xylyl (3a); p-C6H4iPr (3b)) complexes. The heterodinuclear [XPd(μ-dppm)2PtX] complexes 6a (X = Cl) and 6b (X = I) react with RNC (R = o-anisyl) to form the A-frame [XPd(μ-dppm)2(μ-C:N-R)PtX] (X = Cl (9); I (10a)) and M2-bonded [ClPt(μ-dppm)2Pt(CN-R)]Cl (10b) complexes. The dangling ligand-contg. complex [ClPd(μ-dppm)2Pt(η1-dppm:O)](BF4) (7) reacts with xylyl-NC stoichiometrically to produce the dicationic salt [(xylyl-NC)Pd(μ-dppm)2Pt(η1-dppm:O)](BF4)2 (8). Parameters ruling the coordination site terminal vs. bridging are discussed. The precursor 10a reacts with RNC (R = o-anisyl, tBu) to form the heterobimetallic bis(isonitrile) [IPd(μ-dppm)2(μ-C:N-o-anisyl)Pt(CN-R)]I complexes 11b and 12, resp., demonstrating the site selectivity of the second CNR ligand coordination, Pd vs. Pt. The x-ray structures of 11b and 12 were obtained. Complex 12 is the first example of an A-frame system of the Ni-triad bearing two different isocyanide ligands. Several d9-d9 terminal and d8-d8 A-frame homo- and heterodinuclear complexes in 2-MeTHF at 77 K were studied by UV-visible and luminescence spectroscopy. Assignments for the lowest energy absorption and emission bands are made from d. functional theory and time-dependent d. functional theory computations. [on SciFinder(R)
Correction: Saadah et al. Developing Robust Safety Protocols for Radiosurgery within Patient Positioning System Framework. Machines 2024, 12, 106
No full textAfter the publication of the paper, Endre Takacs from Clemson University contacted the corresponding author Alaa Saadah to ask for multiple individuals (Laszlo Fadgyas, Jason Henderson, Tibor Koroknai, Máté Koroknai, David Takacs, Peter Panko, and Endre Takacs) to be added as additional co-authors of the original publication [...
Iron cyclopentadienyl mediated 2-alkyl-2-arylphenylsulfonylacetonitrile synthesis.
No full textA unique route to the synthesis of 2-alkyl-2-arylphenylsulfonylacetonitriles via the nucleophilic arom. substitution (SNAr) of (chloroarene)cyclopentadienyliron complexes with 2-alkyl phenylsulfonylacetonitriles was studied. Reactions of chloroarene complexes with 2-alkyl phenylsulfonylacetonitrile in the presence of K2CO3 in DMF at room temp. gave I (R1 = H, o-, m-, p-Me; R2 = Et, Bu) in good yields. The use of alkylated phenylsulfonylacetonitriles as nucleophiles in the reactions with the p-dichlorobenzene complex gave I (R1 = CR2(CN)(SO2Ph), R2 = Et, Bu). Photolytic demetalation provided an efficient route to the liberation of the arylated phenylsulfonylacetonitriles
Homogeneous degradation of 1,2,9,10-tetrachlorodecane in aqueous solutions using hydrogen peroxide, iron and UV light
No full textThe homogeneous degradation of the polychlorinated n-alkane, 1,2,9,10-tetrachlorodecane (T4C10), was studied in aqueous solutions of hydrogen peroxide, including Fenton and photo-Fenton reaction conditions. All solutions were adjusted to a pH of 2.8 and an ionic strength of 0.1 M NaClO4 prior to photolysis. T4C10 (2 x 10(-6) M) was substantially degraded by the H2O2/UV system (1.0 x 10(-2) M H2O2), with 60% disappearance in 20 min of irradiation in a photoreactor equipped with 300 nm lamps of light intensity 3.6 x 10(-5) Ein L(-1) min(-1) (established by ferrioxalate actinometry). The reaction produced stoichiometric amounts of chloride ion indicating complete dechlorination of the chlorinated n-alkane. T4C10 degraded very slowly under Fenton (Fe2+/H2O2/dark) and Fenton-like (Fe3+/H2O2/dark) conditions. However, when the same solutions were irradiated, T4C10 degraded more rapidly than in the H2O2/UV system, with 61% disappearance in 10 min of exposure. The rapid degradation is related to the enhanced degradation of hydrogen peroxide to oxidizing *OH radicals under photo-Fenton conditions. Degradation was inhibited in both the H2O2/UV and photo-Fenton systems by the addition of KI and tert-butyl alcohol due to *OH scavenging
Epic of the palm tree in Los Angeles
No full textThesis: M. Arch., Massachusetts Institute of Technology, Department of Architecture, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 84-85).The Palm Tree of Los Angeles is it's own entity. It is spelled with a capital P and T. It is also inherently contranymic. (A contranym is defined as a word with two opposite meanings.) Although referred to as "tree," it biologically is not. It is a monocot, similar to grass. Although it is completely embedded into the making of Los Angeles, it is not native to the city at all. Different palm trees from around the world, along with their stories, have participated in constructing myths continuously perpetuated in and by Los Angeles. Current myth making, however, perpetuates a flat, simple narrative. This thesis brings multiple dimensions of positive and negative narratives forward in one continual experience, collapsing these into an alternative mythology. The proposal moves from a flat representation to a collapsed representation. Flat representation is when the myth references only a single story, whereas collapsed representation allows the myth to reference multiple stories. This shift is a new approach on reading the city's history, creating an alternative mythology. By using an aesthetic of Persian miniatures, the thesis re-orientalizes representations of the palm tree. I use the term re-orientalize intentionally, also calling to a re-orienting of the interpreter. This thesis uses a flat aesthetic, but tells a collapsed mythology. The proposal is architecturalized through a series of interventions in the city that can be approached either on their own, or as a constructed loop. The series of interventions are put together as a "nameh," which is a book from a Persian tradition that tells a type of history through painting and verse. This is the Palmnameh: The Epic of The Palm.by Alaa Quraishi.M. Arch
Triplet energy transfers in electrostatic host-guest assemblies of unsaturated organometallic cluster cations and carboxylate-containing porphyrin pigments.
No full textThe unsaturated cyclic [M3(dppm)3(CO)](2+) clusters (M = Pt, Pd; dppm = Ph2PCH2PPh2; such as PF6(-) salt) exhibit a cavity formed by the six dppm-phenyl groups placed like a picket fence above the unsaturated triangular M3 dicationic center. Electrostatic interactions of the M(3+) units inside this cavity with the carboxylate anion RCO2(-) [R = tetraphenylporphyrinatozinc(II), ZnTPP; p-phenyltritolylporphyrinatozinc(II), ZnTTPP; p-phenyltritolylporphyrinatopalladium(II), PdTTPP] form dyads for through-space triplet energy transfers. The binding constants are on the order of 20,000 M(-1) in all six cases (298 K). The energy diagram built upon absorption and emission spectra at 298 and 77 K places the [Pt3(dppm)3(CO)](2+) and [Pd3(dppm)3(CO)](2+) as triplet energy donors, respectively, with respect to the ZnTPPCO2(-), ZnTTPPCO2(-), and PdTTPPCO2(-) pigments, which act as acceptors. Evidence for energy transfer is provided by the transient absorption spectra at 298 K, where triplet-triplet absorption bands of the metalloporphyrin chromophores are depicted at all time (at 298 K) with total absence of the charge-separated state in the nanosecond to microsecond time scale. Rates for energy transfer (ranging in the 10(4) s(-1) time scale) are extracted from the emission lifetimes of the [Pt3(dppm)3(CO)](2+) donor in the free chromophore and the host-guest assemblies. The emission intensity of [Pd3(dppm)3(CO)](2+) is too weak to measure its spectrum and emission lifetime in the presence of the strongly luminescent metalloporphyrin-containing materials. For the [Pd3(dppm)3(CO)](2+)...metalloporphyrin dyads, evidence for fluorescence and phosphorescence lifetime quenching of the porphyrin chromophore at 298 K is provided. These quenchings, exhibiting rates of 10(4) (triplet) and 10(8) s(-1) (singlet), are attributed to a photoinduced electron transfer from the metalloporphyrin to the cluster due to the low reduction potential.Source type: Electronic(1
The first example of multiple oxidation reactions of η6-alkylated aniline-η5-cyclopentadienyliron complexes.
No full textA unique synthetic route to cyclopentadienyliron complexes of functionalized nitrobenzene has been developed via the successive oxidation of the amine and the alkyl groups of their corresponding aniline complexes. Nucleophilic aromatic substitution reactions of the nitroarene complexes with a number of nucleophiles gave rise to monoiron and diiron complexes with various alkyl and keto substituents
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