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1.
Chemistry ; 20(20): 6061-70, 2014 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-24700566

RESUMO

The homometallic hexameric ruthenium cluster of the formula [Ru(III)6(µ3-O)2(µ-OH)2((CH3)3CCO2)12(py)2] (1) (py = pyridine) is solved by single-crystal X-ray diffraction. Magnetic susceptibility measurements performed on 1 suggest that the antiferromagnetic interaction between the Ru(III) centers is dominant, and this is supported by theoretical studies. Theoretical calculations based on density functional methods yield eight different exchange interaction values for 1: J1 = -737.6, J2 = +63.4, J3 = -187.6, J4 = +124.4, J5 = -376.4, J6 = -601.2, J7 = -657.0, and J8 = -800.6 cm(-1). Among all the computed J values, six are found to be antiferromagnetic. Four exchange values (J1, J6, J7 and J8) are computed to be extremely strong, with J8, mediated through one µ-hydroxo and a carboxylate bridge, being by far the largest exchange obtained for any transition-metal cluster. The origin of these strong interactions is the orientation of the magnetic orbitals in the Ru(III) centers, and the computed J values are rationalized by using molecular orbital and natural bond order analysis. Detailed NMR studies ((1)H, (13)C, HSQC, NOESY, and TOCSY) of 1 (in CDCl3) confirm the existence of the solid-state structure in solution. The observation of sharp NMR peaks and spin-lattice time relaxation (T1 relaxation) experiments support the existence of strong intramolecular antiferromagnetic exchange interactions between the metal centers. A broad absorption peak around 600-1000 nm in the visible to near-IR region is a characteristic signature of an intracluster charge-transfer transition. Cyclic voltammetry experiments show that there are three reversible one-electron redox couples at -0.865, +0.186, and +1.159 V with respect to the Ag/AgCl reference electrode, which corresponds to two metal-based one-electron oxidations and one reduction process.


Assuntos
Oxigênio/química , Piridinas/química , Rutênio/química , Cristalografia por Raios X , Dimerização , Espectroscopia de Ressonância Magnética , Imãs/química , Modelos Moleculares , Piridinas/síntese química , Teoria Quântica , Espectroscopia de Infravermelho com Transformada de Fourier
2.
J Crohns Colitis ; 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38881153

RESUMO

INTRODUCTION: 30-40% patients with acute severe ulcerative colitis (ASUC) fail intravenous (IV) steroids requiring medical rescue therapy/colectomy. Low baseline albumin predicts steroid non-response, and exclusive enteral nutrition (EEN) has been shown to improve steroid response and albumin levels. Albumin infusion due to its anti-inflammatory and anti-oxidant properties might further improve steroid response in ASUC, which was evaluated in present study. METHODS: In this open-label randomized controlled trial, patients with ASUC were randomized in 1:1 ratio to albumin + standard of care (SOC) + EEN vs. SOC + EEN (Jan2021 - Feb2023). Both arms received 5 days of EEN with 400 mg IV hydrocortisone/day. Patients in albumin arm were administered 5 days of 20% w/v intravenous albumin (100 ml). Primary outcome was 1) steroid failure (need for rescue medical therapy or colectomy) and 2) proportion of patients with adverse events. RESULTS: Sixty-one patients (albumin-30, SOC-31)(mean age-31.6±0.4 years, male-57.4%), were included. Baseline characteristics were comparable. There was no difference in steroid failure between albumin and SOC arm(10/30(33.33 %) vs 13/31(41.94 %), p=0.49). No adverse events were reported with albumin infusions. Colectomy rate(10% vs 9.68%, P=1), response to salvage medical therapy (88.89% vs 76.92%, P=0.62) and median duration of hospitalization (10.5(7-16) vs 10(7-20), P=0.43) were also comparable. Long-term composite outcome of colectomy and re-admission rates was numerically higher in the albumin than SOC arm (37.04% vs 17.86%, p>0.05), although it did not reach statistical significance. CONCLUSION: There was no benefit of intravenous albumin infusion as an adjunct to IV steroids and EEN in patients with ASUC.

3.
J Med Econ ; 23(11): 1345-1355, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32815766

RESUMO

AIM: To characterize vaso-occlusive crises (VOCs) and describe healthcare costs among commercially-insured, Medicaid-insured, and Medicare-insured patients with sickle cell disease (SCD). MATERIALS AND METHODS: The IBM Truven Health MarketScan Commercial (2000-2018), Medicaid Analytic eXtract (2008-2014), and Medicare Research Identifiable Files (2012-2016) databases were used to identify patients with ≥2 SCD diagnoses. Study measures were evaluated during a 12-month follow-up period, stratified by annual number of VOCs (i.e. 0, 1, and ≥2). RESULTS: Among 16,092 commercially-insured patients (mean age = 36.7 years), 35.3% had 1+ VOCs. Mean annual total all-cause healthcare costs were $15,747, $27,194, and $64,555 for patients with 0, 1, and 2+ VOCs, respectively. Total all-cause healthcare costs were mainly driven by inpatient (0 VOC = 31.0%, 1 VOC = 53.1%, 2+ VOCs = 65.4%) and SCD-related costs (0 VOC = 56.4%, 1 VOC = 78.4%, 2+ VOCs = 93.9%). Among 18,287 Medicaid-insured patients (mean age = 28.5 years, fee-for-service = 50.2%), 63.9% had 1+ VOCs. Mean annual total all-cause healthcare costs were $16,750, $29,880, and $64,566 for patients with 0, 1, and 2+ VOCs, respectively. Inpatient costs (0 VOC = 37.2%, 1 VOC = 64.3%, 2+ VOCs = 72.9%) and SCD-related costs (0 VOC = 60.9%, 1 VOC = 73.8%, 2+ VOCs = 92.2%) accounted for a significant proportion of total all-cause healthcare costs. Among 15,431 Medicare-insured patients (mean age = 48.2 years), 55.1% had 1+ VOCs. Mean annual total all-cause healthcare costs were $21,877, $29,250, and $58,308 for patients with 0, 1, and ≥2 VOCs, respectively. Total all-cause healthcare costs were mainly driven by inpatient (0 VOC = 47.9%, 1 VOC = 54.9%, 2+ VOCs = 67.5%) and SCD-related costs (0 VOC = 74.9%, 1 VOC = 84.4%, 2+ VOCs = 95.3%). LIMITATIONS: VOCs managed at home were not captured. Analyses were descriptive in an observational setting; thus, no causal relationships can be inferred. CONCLUSIONS: A high proportion of patients experienced VOCs across payers. Furthermore, inpatient and SCD-related costs accounted for a significant proportion of total all-cause healthcare costs, which increased with VOC frequency.


Assuntos
Anemia Falciforme/economia , Seguro Saúde/economia , Medicaid/economia , Adulto , Anemia Falciforme/fisiopatologia , Feminino , Gastos em Saúde , Serviços de Saúde/economia , Serviços de Saúde/estatística & dados numéricos , Humanos , Masculino , Medicare/economia , Aceitação pelo Paciente de Cuidados de Saúde/estatística & dados numéricos , Estados Unidos
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