Anomalous pressure-density relations and speed of sound in bubbly water systems.

The speed of sound in bubbly water is an important parameter in the wave equations governing pressure-density relations for turbulent multi-phase flow simulations. Recent molecular simulation results indicate that, for bubbles that are thermodynamically stable at finite volume conditions, the derivative of total pressure P with density ρ has a negative sign, complicating the interpretation of the speed of sound. We show that such a negative compressibility is thermodynamically consistent in a single-component two-phase model at finite volume, and identify an empirically derived equation of state to illustrate that this observation is not an artifact of small simulation length scales.

Square-planar imido complexes of cobalt: synthesis, reactivity and computational study.

Treatment of [Co(N)(PNP)] (PNP = anion of 2,5-bis(di--butylphosphinomethyl)pyrrole) with one equivalent of an aryl azide generates the four-coordinate imido complexes [Co(NAr)(PNP)] (Ar = mesityl, phenyl, or 4-Bu-phenyl). X-ray crystallographic analysis of the compounds shows an unusual square-planar geometry about cobalt with nearly linear imido units. In the presence of the hydrogen atom donor, TEMPOH, [Co(NPh)(PNP)] undergoes addition of the H atom to the imido nitrogen to generate the corresponding amido complex, [Co(NHPh)(PNP)], whose structure and composition were verified by independent synthesis.

Large-scale molecular dynamics simulations of bubble collapse in water: Effects of system size, water model, and nitrogen.

Molecular dynamics simulations in the microcanonical ensemble are performed to study the collapse of a bubble in liquid water using the single-site mW and the four-site TIP4P/2005 water models. To study system size effects, simulations for pure water systems are performed using periodically replicated simulation boxes with linear dimensions, L, ranging from 32 to 512 nm with the largest systems containing 8.7 × 106 and 4.

Structural Characterization of the [CuOR] Core.

Formal Cu(III) complexes bearing an oxygen-based auxiliary ligand ([CuOR], R = H or CHCF) were stabilized by modulating the donor character of supporting ligand L (L = 4-Y, ,'-bis(2,6-diisopropylphenyl)-2,6-pyridinedicarboxamide, Y = H or OMe) and/or the basicity of the auxiliary ligand, enabling the first characterization of these typically highly reactive cores by NMR spectroscopy and X-ray crystallography. Enhanced lifetimes in solution and slowed rates of PCET with a phenol substrate were observed. NMR spectra corroborate the = 0 ground states of the complexes, and X-ray structures reveal shortened Cu-ligand bond distances that match well with theory.

Redefining Medication Management in Dialysis: A Kidney Pharmacy Quality Pyramid.

Patients with end-stage renal disease treated with dialysis are often prescribed complex medication regimens, placing them at risk for drug-drug interactions and other medication-related problems. Particularly in the context of a broader interest in more patient-centered value-based care, improving medication management is an increasingly important focus area. However, current medication management metrics, designed for the broader patient population, may not be well suited to the specific needs of patients with kidney disease, especially given the complexity of medication regimens used by dialysis patients.

Influence of gender and age on haemodialysis practices: a European multicentre analysis.

Background: Women of all ages and elderly patients of both genders comprise an increasing proportion of the haemodialysis population. Worldwide, significant differences in practice patterns and treatment results exist between genders and among younger versus older patients. Although efforts to mitigate sex-based differences have been attempted, significant disparities still exist.

Achievement of renal anemia KDIGO targets by two different clinical strategies - a European hemodialysis multicenter analysis.

Background: The optimal treatment algorithm for iron therapy and the use of erythropoiesis-stimulating agents (ESA) in anemic hemodialysis (HD) patients has not been established. Hemoglobin (Hb) target levels can be achieved through more frequent intravenous (IV) iron use with lower ESA dose, or with less iron dosing but higher ESA. ESA therapy to correct anemia may result in severe arterial and venous thrombotic complications and the evidence base evaluating hard clinical outcomes related to the use of IV iron is sparse.

Backbone Dehydrogenation in Pyrrole-Based Pincer Ligands.

Treatment of both [CoCl( PNP)] and [NiCl( PNP)] ( PNP = anion of 2,5-bis((di- tert-butylphosphino)methyl)pyrrole) with one equivalent of benzoquinone affords the corresponding chloride complexes containing a dehydrogenated PNP ligand, dPNP ( dPNP = anion of 2,5-bis((di- tert-butylphosphino)methylene)-2,5-dihydropyrrole). Dehydrogenation of PNP to dPNP results in minimal change to steric profile of the ligand but has important consequences for the resulting redox potentials of the metal complexes, resulting in the ability to isolate both [CoH( dPNP)] and [CoEt( dPNP)], which are more challenging (hydride) or not possible (ethyl) to prepare with the parent PNP ligand. Electrochemical measurements with both the Co and Ni dPNP species demonstrate a substantial shift in redox potentials for both the M(II/III) and M(II/I) couples.

Preparation and reactivity of a square-planar PNP cobalt(ii)-hydrido complex: isolation of the first {Co-NO}-hydride.

The synthesis of a square-planar cobalt(ii) hydrido complex supported by a pyrrole-based PNP ligand has been reinvestigated and its reactivity with various small molecules examined. Preparation of the complex was accomplished by treatment of the corresponding chloride complex, [CoCl(PNP)] (PNP = anion of 2,5-bis((di-tert-butylphosphino)methyl)pyrrole), with di-iso-butylaluminum hydride (DIBAL). Reaction of [CoCl(PNP)] with other hydride sources such as NaEtBH and LiAlH resulted in mixtures of the desired Co(ii) hydride along with the reduced Co(i) species, [Co(N)(PNP)], as the primary product.

Synthesis and characterisation of ruthenium-nitrosyl complexes in oxygen-rich ligand environments.

A series of new {Ru-NO} complexes containing Kläui's tripodal oxygen ligand, [CpCo{P(O)(OMe)}] (L), and substituted catecholates have been prepared by chloride exchange with [Ru(L)(NO)Cl]. The [Ru(L)(NO)(cat)] complexes (cat = dianion of catechol, 3,5-di-tert-butylcatechol, tetrabromocatechol, or 2,3-dihydroxynaphthalene) demonstrate spectroscopic features and redox properties consistent with the electronic character of the catecholate ligands. Several of the compounds display reversible oxidation events by cyclic voltammetry arising from the redox non-innocence of the catecholate ligands.

Data completeness as an unmeasured confounder in dialysis facility performance comparison with 1-year follow-up .

Unlabelled: ;Aims: Standardized mortality and hospitalization ratios (SMRs, SHRs) are used to measure dialysis facility performance in the US, with adjustment for demographics and comorbid conditions derived from the end-stage renal disease (ESRD) Medical Evidence (ME) Report. Sensitivities are low for ME-based comorbidity, and levels of under-reporting may differ among facilities. We aimed to assess the effect of data inaccuracy on performance comparison.

Pragmatic Trials in Maintenance Dialysis: Perspectives from the Kidney Health Initiative.

Pragmatic clinical trials are conducted under the real-world conditions of clinical care delivery. As a result, these trials yield findings that are highly generalizable to the nonresearch setting, identify interventions that are readily translatable into clinical practice, and cost less than trials that require extensive research infrastructures. Maintenance dialysis is a setting especially well suited for pragmatic trials because of inherently frequent and predictable patient encounters, highly granular and uniform data collection, use of electronic data systems, and delivery of care by a small number of provider organizations to approximately 90% of patients nationally.

Predictive Score for Posttransplantation Outcomes.

Background: Most current scoring tools to predict allograft and patient survival upon kidney transplantion are based on variables collected posttransplantation. We developed a novel score to predict posttransplant outcomes using pretransplant information including routine laboratory data available before or at the time of transplantation.

Methods: Linking the 5-year patient data of a large dialysis organization to the Scientific Registry of Transplant Recipients, we identified 15 125 hemodialysis patients who underwent first deceased transplantion.

A Matter of Choice: Opportunities and Obstacles Facing People with ESRD.

Kidney failure is an overwhelming, life-shattering event, but patients with ESRD do not see themselves as being at the end stage of their lives. On the contrary, patients opting for kidney dialysis are choosing to live. Ideally, then, public policy would support patients' choices about how to live-specifically, the choice to continue working.

Socioeconomic Status of Counties Where Dialysis Clinics Are Located Is an Important Factor in Comparing Dialysis Providers.

This study assessed the hypothesis that the clinic site of service socioeconomic status (SES) represents an unmeasured confounder for clinical outcome comparisons between dialysis clinics and provider types, using data from the federal pay-for-performance program for end-stage renal disease. A total of 6506 dialysis facilities were categorized by clinic SES status (rurality and poverty status). Clinics were then grouped by provider type (chain size and tax status).

Comorbidity ascertainment from the ESRD Medical Evidence Report and Medicare claims around dialysis initiation: a comparison using US Renal Data System data.

Background: The end-stage renal disease Medical Evidence Report serves as a source of comorbid condition data for risk adjustment of quality metrics. We sought to compare comorbid condition data in the Medical Evidence Report around dialysis therapy initiation with diagnosis codes in Medicare claims.

Study Design: Observational cohort study using US Renal Data System data.

ESRD special needs plans: a proof of concept for integrated care.

Since the completion of the Centers for Medicare and Medicaid Services' end-stage renal disease (ESRD) demonstration projects, passage of the Affordable Care Act, and announcement of ESRD Seamless Care Organizations (ESCOs) by CMS' Innovation Center, it seems that ESRD-centered accountable care organizations will be the future model for kidney care of Medicare beneficiaries. Regardless of what you call it--managed care organization, special needs plan, ESCO--balancing quality of health care with costs of health care will continue to be the primary directive for physicians and institutions using integrated care management (ICM) strategies to manage their ESRD patients' health. The renal community has had previous success with ICM, and these experiences could help to guide our way.

Confounders of mortality and hospitalization rate calculations for profit and nonprofit dialysis facilities: analytic augmentation.

Background: Patient outcomes have been compared on the basis of the profit status of the dialysis provider (for-profit [FP] and not-for-profit [NFP]). In its annual report, United States Renal Data System (USRDS) provides dialysis provider level death and hospitalization rates adjusted by age, race, sex, and dialysis vintage; however, recent analyses have suggested that other variables impact these outcomes. Our current analysis of hospitalization and mortality rates of hemodialysis patients included adjustments for those used by the USRDS plus other potential confounders: facility geography (end-stage renal disease network), length of facility ownership, vascular access at first dialysis session, and pre-dialysis nephrology care.

Mortality rates do not differ among patients prescribed various vitamin D agents.

Background: Limited well-controlled research exists examining the impact of different formulations of oral vitamin D on clinical outcomes in dialysis patients, specifically those on peritoneal dialysis. For this retrospective mortality analysis, we compared mortality rates of patients on 3 of the most commonly prescribed vitamin D agents.

Methods: We examined 2 years (7/1/2008 to 6/30/2010) of oral medication records of peritoneal dialysis patients from a large US dialysis organization.