Indocyanine green angiography guidance for vascular preservation in skin and nipple sparing mastectomy.

PURPOSE: The skin and/or nipple-sparing approach has become an oncologically sound and desirable choice for women choosing mastectomy. Indocyanine green (ICG) perfusion imaging has been shown to reduce ischemic complications in mastectomy skin flaps. Immediate reconstruction requires a well-vascularized skin flap capable of tolerating full expansion. Identification of the perforating subcutaneous vessels to the skin envelope may allow for better and more consistent blood vessel preservation and flap perfusion. METHODS: The authors conducted an institutional review board-approved prospective study with 41 patients to assess the feasibility of using ICG perfusion imaging to visualize, cutaneously map, and preserve the vessels that supply the skin flap and nipple-areolar complex. For each patient, the number of vessels initially mapped, the number of vessels preserved, the extent to which each vessel was preserved, and the proportion of the flap with adequate perfusion (as defined by the SPY-Q > 20% threshold) was recorded and analyzed. RESULTS: Vessels were able to be identified and marked in a high majority of patients (90%). There was a moderate linear relationship between the number of vessels marked and the number preserved. Successful mapping of vessels was associated with lower rates of wound breakdown (p = 0.036). Mapping and preserving at least one vessel led to excellent flap perfusion (> 90%). No increase in complications was observed from utilizing ICG angiography preoperatively. CONCLUSION: This prospective study using preoperative ICG perfusion mapping demonstrated safety, feasibility, and good prognostic outcomes. LEVEL OF EVIDENCE: III.

Differences in Health Care Utilization of High-Need and High-Cost Patients of Federally Funded Health Centers Versus Other Primary Care Providers.

BACKGROUND: Primary care providers (PCP) differ in their ability to address the needs and reduce use of costly services among complex Medicaid beneficiaries. Among PCPs, Health Resources and Services Administration (HRSA)-funded health centers (HCs) are shown to provide high-value care. OBJECTIVE: We compared health care utilization of complex Medicaid managed care beneficiaries whose PCPs were HCs versus 3 other groups. RESEARCH DESIGN: Cross-sectional study using propensity score matching comparing health care use by provider type, controlling for demographics, health status, and other covariates. SUBJECTS: California Medicaid administrative data for complex adult managed care beneficiaries with at least 1 primary care visit in 2018. MEASURES: Primary and specialty care evaluation & management visits and services; emergency department (ED) visits; and hospitalizations. PCPs included HCs, clinics not funded by HRSA, solo, and group practice providers. RESULTS: HRSA-funded HCs had lower predicted rates of specialty evaluation & management and other services than all others; lower predicted probability of any ED visits than clinics not funded by HRSA [54% (95% CI: 53%-55%) vs. 56% (95% CI: 55%-57%)] and group practice providers [51% (95% CI: 51%-52%) vs. 52% (95% CI: 52%-53%)]; and lower PP of any hospitalizations than solo [20% (95% CI: 19%-20%) vs. 23% (95% CI: 22%-24%)] and group practice providers [21% (95% CI: 20%-21%) vs. 24% (95% CI: 23%-24%)]. CONCLUSIONS: Differences in HC care delivery and practices were associated with lower use of specialty, ED, and hospitalization visits compared with other PCPs for complex Medicaid managed care beneficiaries. Understanding the underlying reasons for these utilization differences may promote better outcomes among these patients.

Underrepresentation of racial and ethnic minority groups in gynecologic oncology: An analysis of over 250 trials.

OBJECTIVE: To describe the participation of racial and ethnic minority groups (REMGs) in gynecologic oncology trials. METHODS: Gynecologic oncology studies registered on ClinicalTrials.gov between 2007 and 2020 were identified. Trials with published results were analyzed based on reporting of race/ethnicity in relation to disease site and trial characteristics. Expected enrollment by race/ethnicity was calculated and compared to actual enrollment, adjusted for 2010 US Census population data. RESULTS: 2146 gynecologic oncology trials were identified. Of published trials (n = 252), 99 (39.3%) reported race/ethnicity data. Recent trials were more likely to report these data (36% from 2007 to 2009; 51% 2013-2015; and 53% from 2016 to 2018, p = 0.01). Of all trials, ovarian cancer trials were least likely to report race/ethnicity data (32.1% vs 39.3%, p = 0.011). Population-adjusted under-enrollment for Blacks was 7-fold in ovarian cancer, Latinx 10-fold for ovarian and 6-fold in uterine cancer trials, Asians 2.5-fold in uterine cancer trials, and American Indian and Alaska Native individuals 6-fold in ovarian trials. Trials for most disease sites have enrolled more REMGs in recent years - REMGs made up 19.6% of trial participants in 2007-2009 compared to 38.1% in 2016-2018 (p < 0.0001). CONCLUSION: Less than half of trials that published results reported race/ethnicity data. Available data reveals that enrollment of REMGs is significantly below expected rates based on national census data. These disparities persisted even after additionally adjusting for population size. Despite improvement in recent years, additional recruitment of REMGs is needed to achieve more representative and equitable participation in gynecologic cancer clinical trials.

Obstacles to Accepting Care: Understanding Why Obstetric Patients Leave against Medical Advice.

INTRODUCTION: Discharge "against medical advice" (AMA) in the obstetric population is overall under-studied but disproportionally affects marginalized populations and is associated with worse perinatal outcomes. Reasons for discharges AMA are not well understood. The objective of this study is to identify the obstacles that prevent obstetric patients from accepting recommended care and highlight the structural reasons behind AMA discharges. METHODS: Electronic health records of patients admitted to antepartum, peripartum, or postpartum services between 2008 and 2018 who left "AMA" were reviewed. Progress notes from clinicians and social workers were extracted and analyzed. Reasons behind discharge were categorized using qualitative thematic analysis. RESULTS: Fifty-seven (0.12%) obstetric patients were discharged AMA. Reasons for discharge were organized into two overarching themes: extrinsic (50.9%) and intrinsic (40.4%) obstacles to accepting care. Eleven participants (19.3%) had no reason documented for their discharge. Extrinsic obstacles included childcare, familial responsibilities, and other obligations. Intrinsic obstacles included disagreement with provider regarding medical condition or plan, emotional distress, mistrust or discontent with care team, and substance use. DISCUSSION: The term "AMA" casts blame on individual patients and fails to represent the systemic barriers to staying in care. Obstetric patients were found to encounter both extrinsic and intrinsic obstacles that led them to leave AMA. Healthcare providers and institutions can implement strategies that ameliorate structural barriers. Partnering with patients to prevent discharges AMA would improve maternal and infant health and progress towards reproductive justice.

Structure and Site Evolution of Framework Ni Species in MIL-127 MOFs for Propylene Oligomerization Catalysis.

A mixed-valence oxotrimer metal-organic framework (MOF), Ni-MIL-127, with a fully coordinated nickel atom and two iron atoms in the inorganic node, generates a missing linker defect upon thermal treatment in helium (>473 K) to engender an open coordination site on nickel which catalyzes propylene oligomerization devoid of any cocatalysts or initiators. This catalyst is stable for ∼20 h on stream at 500 kPa and 473 K, unprecedented for this chemistry. The number of missing linkers on synthesized and activated Ni-MIL-127 MOFs is quantified using temperature-programmed oxidation, 1H nuclear magnetic resonance spectroscopy, and X-ray absorption spectroscopy to be ∼0.7 missing linkers per nickel; thus, a majority of Ni species in the MOF framework catalyze propylene oligomerization. In situ NO titrations under reaction conditions enumerate ∼62% of the nickel atoms as catalytically relevant to validate the defect density upon thermal treatment. Propylene oligomerization rates on Ni-MIL-127 measured at steady state have activation energies of 55-67 kJ mol-1 from 448 to 493 K and are first-order in propylene pressures from 5 to 550 kPa. Density functional theory calculations on cluster models of Ni-MIL-127 are employed to validate the plausibility of the missing linker defect and the Cossee-Arlman mechanism for propylene oligomerization through comparisons between apparent activation energies from steady-state kinetics and computation. This study illustrates how MOF precatalysts engender defective Ni species which exhibit reactivity and stability characteristics that are distinct and can be engineered to improve catalytic activity for olefin oligomerization.

Ensuring Equitable Care in Diabetes Management Among Patients of Health Resources & Services Administration-Funded Health Centers in the United States.

Aim: To explore whether there are racial/ethnic differences in diabetes management and outcomes among adult health center (HC) patients with type 2 diabetes. Methods: We analyzed data from the 2014 Health Center Patient Survey, a national sample of HC patients. We examined indicators of diabetes monitoring (A1C testing, annual foot/eye doctor visits, and cholesterol checks) and care management (specialist referrals, individual treatment plan, and receipt of calls/appointments/home visits). We also examined diabetes-specific outcomes (blood glucose levels, diabetes-related emergency department [ED] visits/hospitalizations, and diabetes self-management confidence) and general outcomes (number of doctor visits, ED visits, and hospitalizations). We used multilevel logistic regression models to examine racial/ethnic disparities by the above indicators. Results: We found racial/ethnic parity in A1C testing, eye doctor visits, and diabetes-specific outcomes. However, Hispanics/Latinos (odds ratio [OR] 0.26), non-Hispanic African Americans (OR 0.25), and Asians (OR 0.11) were less likely to receive a cholesterol check than Whites. Non-Hispanic African Americans (OR 0.43) were less likely to have frequent doctor visits, while Hispanic/Latino patients (OR 0.45) were less likely to receive an individual treatment plan. Conclusion: HCs largely provide equitable diabetes care but have room for improvement in some indicators. Tailored efforts such as culturally competent care and health education for some racial/ethnic groups may be needed to improve diabetes management and outcomes.

Staffing transformation following Patient-Centered Medical Home recognition among Health Resources & Services Administration-funded health centers.

INTRODUCTION: Patient-Centered Medical Home (PCMH) recognition is designed to promote whole-person team-based and integrated care. PURPOSE: Our goal was to assess changes in staffing infrastructure that promoted team-based and integrated care delivery before and after PCMH recognition in Health Resources & Services Administration (HRSA)-funded health centers (HCs). METHODOLOGY/APPROACH: We identified changes in staffing 2 years before and 3 years after PCMH recognition using 2010-2019 Uniform Data System data among three cohorts of HCs that received PCMH recognition in 2013 ( n = 346), 2014 ( n = 207), and 2015 ( n = 115). Our outcomes were team-based ratio (full-time equivalent medical and nonmedical providers and staff to one primary care physician) and a multidisciplinary staff ratio (allied medical and nonmedical staff to 1,000 patients). We used mixed-effects Poisson regression models. RESULTS: The earlier cohorts served fewer complex patients and were larger before PCMH recognition. Three years following recognition, the 2013 and 2014 cohorts had significantly larger team-based ratios, and all three cohorts had significantly larger multidisciplinary staff ratios. Cohorts varied, however, in the type of staff that drove this change. Both ratios increased in the longer term. CONCLUSION: Our study suggests that growth in team-based and multidisciplinary staff ratios in each cohort may have been due to a combination of HCs' perceptions of need for specific services, HRSA funding, and technical assistance opportunities. POLICY IMPLICATIONS: Further research is needed to understand barriers such as costs of employing a multidisciplinary staff, particularly those that cannot directly bill for services as well as whether such changes lead to practice transformation and improved quality of care.

Light-Driven Hydrodefluorination of Electron-Rich Aryl Fluorides by an Anionic Rhodium-Gallium Photoredox Catalyst.

An anionic Rh-Ga complex catalyzed the hydrodefluorination of challenging C-F bonds in electron-rich aryl fluorides and trifluoromethylarenes when irradiated with violet light in the presence of H2 , a stoichiometric alkoxide base, and a crown-ether additive. Based on theoretical calculations, the lowest unoccupied molecular orbital (LUMO), which is delocalized across both the Rh and Ga atoms, becomes singly occupied upon excitation, thereby poising the Rh-Ga complex for photoinduced single-electron transfer (SET). Stoichiometric and control reactions support that the C-F activation is mediated by the excited anionic Rh-Ga complex. After SET, the proposed neutral Rh0 intermediate was detected by EPR spectroscopy, which matched the spectrum of an independently synthesized sample. Deuterium-labeling studies corroborate the generation of aryl radicals during catalysis and their subsequent hydrogen-atom abstraction from the THF solvent to generate the hydrodefluorinated arene products. Altogether, the combined experimental and theoretical data support an unconventional bimetallic excitation that achieves the activation of strong C-F bonds and uses H2 and base as the terminal reductant.

Beyond Radical Rebound: Methane Oxidation to Methanol Catalyzed by Iron Species in Metal-Organic Framework Nodes.

Recent work has exploited the ability of metal-organic frameworks (MOFs) to isolate Fe sites that mimic the structures of sites in enzymes that catalyze selective oxidations at low temperatures, opening new pathways for the valorization of underutilized feedstocks such as methane. Questions remain as to whether the radical-rebound mechanism commonly invoked in enzymatic and homogeneous systems also applies in these rigid-framework materials, in which resisting the overoxidation of desired products is a major challenge. We demonstrate that MOFs bearing Fe(II) sites within Fe3-µ3-oxo nodes active for conversion of CH4 + N2O mixtures (368-408 K) require steps beyond the radical-rebound mechanism to protect the desired CH3OH product. Infrared spectra and density functional theory show that CH3OH(g) is stabilized as Fe(III)-OCH3 groups on the MOF via hydrogen atom transfer with Fe(III)-OH groups, eliminating water. Consequently, upon addition of a protonic zeolite in inter- and intrapellet mixtures with the MOF, we observed increases in CH3OH selectivity with increasing ratio and proximity of zeolitic H+ to MOF-based Fe(II) sites, as methanol is protected within the zeolite. We infer from the data that CH3OH(g) is formed via the radical-rebound mechanism on Fe(II) sites but that subsequent transport and dehydration steps are required to protect CH3OH(g) from overoxidation. The results demonstrate that the radical-rebound mechanism commonly invoked in this chemistry is insufficient to explain the reactivity of these systems, that the selectivity-controlling steps involve both chemical and physical rate phenomena, as well as offering a strategy to mitigate overoxidation in these and similar systems.

Site Densities, Rates, and Mechanism of Stable Ni/UiO-66 Ethylene Oligomerization Catalysts.

Nickel-functionalized UiO-66 metal organic frameworks (MOFs) oligomerize ethylene in the absence of cocatalysts or initiators after undergoing ethylene-pressure-dependent transients and maintain stable oligomerization rates for >15 days on stream. Higher ethylene pressures shorten induction periods and engender more active sites for ethylene oligomerization; these sites exhibit invariant selectivity-conversion characteristics to justify that only one type of catalytic center is relevant for oligomerization. The number of active sites is estimated using in situ NO titration to disambiguate the effect of increased reaction rates upon exposure to increasing ethylene pressures. After accounting for augmented site densities with increasing ethylene pressures, ethylene oligomerization is first order in ethylene pressure from 100 to 1800 kPa with an activation energy of 81 kJ mol-1 at temperatures from 443-503 K on Ni/UiO-66. A representative Ni/UiO-66 cluster model that mimics high ethylene pressure process conditions is validated with ab initio thermodynamic analysis, and the Cossee-Arlman mechanism is posited based on comparisons between experimental and computed activation enthalpies from density functional theory calculations on these cluster models of Ni/UiO-66. The insights gained from experiment and theory help rationalize evolution in structure and stability for ethylene oligomerization Ni/UiO-66 MOF catalysts.

Cooperative Bond Activation and Facile Intramolecular Aryl Transfer of Nickel-Aluminum Pincer-type Complexes.

Pincer-type nickel-aluminum complexes were synthesized using two equivalents of the phosphinoamide, [PhNCH2 Pi Pr2 ]- . The Ni0 -AlIII complexes, {(Mes PAlP)Ni}2 (µ-N2 ) and {(Mes PAlP)Ni}2 (µ-COD), where Mes PAlP is (Mes)Al(NPhCH2 Pi Pr2 )2 , were structurally characterized. The (PAlP)Ni system exhibited cooperative bond cleavage mediated by the two-site Ni-Al unit, including oxidative addition of aryl halides, H2 activation, and ortho-directed C-H bond activation of pyridine N-oxide. One intriguing reaction is the reversible intramolecular transfer of the mesityl ring from the Al to the Ni site, which is evocative of the transmetalation step during cross-coupling catalysis. The aryl-transfer product,(THF)Al(NPhCH2 Pi Pr2 )2 Ni(Mes), is the first example of a first-row transition metal-aluminyl pincer complex. The addition of a judicious donor enables the Al metalloligand to convert reversibly between the alane and aluminyl forms via aryl group transfer to and from Ni, respectively. Theoretical calculations support a zwitterionic Niδ- -Alδ+ electronic structure in the nickel-aluminyl complex.

Catalytic Hydrogenolysis of Aryl C-F Bonds Using a Bimetallic Rhodium-Indium Complex.

A homogeneous rhodium-indium catalyst hydrodefluorinates substrates bearing strong aryl C-F bonds, including difluoro- and fluorobenzene, using 1 atm of H2, alkoxide bases, and moderate temperatures (70-90 °C). Characterization of catalytic intermediates establishes a formal Rh-I/RhI redox cycle. The Rh → In interaction is proposed to enable catalysis by stabilizing the reactive Rh-I species, which is responsible for cleaving the Ar-F bond and is ultimately regenerated using H2 and base.

Rare-Earth Supported Nickel Catalysts for Alkyne Semihydrogenation: Chemo- and Regioselectivity Impacted by the Lewis Acidity and Size of the Support.

Bimetallic catalysts of nickel(0) with a trivalent rare-earth ion or Ga(III), NiML3 (where L is [iPr2PCH2NPh]-, and M is Sc, Y, La, Lu, or Ga), were investigated for the selective hydrogenation of diphenylacetylene (DPA) to (E)-stilbene. Each bimetallic complex features a relatively short Ni-M bond length, ranging from 2.3395(8) Å (Ni-Ga) to 2.5732(4) Å (Ni-La). The anodic peak potentials of the NiML3 complexes vary from -0.48 V to -1.23 V, where the potentials are negatively correlated with the Lewis acidity of the M(III) ion. Three catalysts, Ni-Y, Ni-Lu, and Ni-Ga, showed nearly quantitative conversions in the semihydrogenation of DPA, with NiYL3 giving the highest selectivity for (E)-stilbene. Initial rate studies were performed on the two tandem catalytic reactions: DPA hydrogenation and (Z)-stilbene isomerization. The catalytic activity in DPA hydrogenation follows the order Ni-Ga > Ni-La > Ni-Y > Ni-Lu > Ni-Sc. The ranking of catalysts by (Z)-stilbene isomerization initial rates is Ni-Ga ≫ Ni-Sc > Ni-Lu > Ni-Y > Ni-La. In operando 31P and 1H NMR studies revealed that in the presence of DPA, the Ni bimetallic complexes supported by Y, Lu, and La form the Ni(η2-alkyne) intermediate, (η2-PhC≡CPh)Ni(iPr2PCH2NPh)2M(κ2-iPr2PCH2NPh). In contrast, the Ni-Ga resting state is the Ni(η2-H2) species, and Ni-Sc showed no detectable binding of either substrate. Hence, the mechanism of Ni-catalyzed diphenylacetylene semihydrogenation adheres to two different kinetics: an autotandem pathway (Ni-Ga, Ni-Sc) versus temporally separated tandem reactions (Ni-Y, Ni-Lu, Ni-La). Collectively, the experimental results demonstrate that modulating a base-metal center via a covalently appended Lewis acidic support is viable for promoting selective alkyne semihydrogenation.

Bioinspired Nickel Complexes Supported by an Iron Metalloligand.

Nature utilizes multimetallic sites in metalloenzymes to enable multielectron chemical transformations at ambient conditions and low overpotentials. One such example of multimetallic cooperativity can be found in the C-cluster of Ni-carbon monoxide dehydrogenase (CODH), which interconverts CO and CO2. Toward a potential functional model of the C-cluster, a family of Ni-Fe bimetallic complexes was synthesized that contain direct metal-metal bonding interactions. The complexes were characterized by X-ray crystallography, various spectroscopies (NMR, EPR, UV-vis, Mössbauer), and theoretical calculations. The Ni-Fe bimetallic system has a reversible Fe(III)/Fe(II) redox couple at -2.10 V (vs Fc+/Fc). The Fe-based "redox switch" can turn on CO2 reactivity at the Ni(0) center by leveraging the Ni→Fe dative interaction to attenuate the Ni(0) electron density. The reduced Ni(0)Fe(II) species mediated the formal two-electron reduction of CO2 to CO, providing a Ni-CO adduct and CO32- as products. During the reaction, an intermediate was observed that is proposed to be a Ni-CO2 species.

'I feel like a person has a right to use a product to protect themselves ': a qualitative study of the risk-benefit calculus on women's contraceptive use and choice.

Background Reducing pregnancy risk requires a multidimensional approach to sexual and reproductive health product development. The purpose of this analysis is to identify, compare, and contrast women's pre-use beliefs and attitudes about three different forms of contraceptives: intravaginal rings; spermicide in conjunction with condoms; and oral contraceptive pills - and explore how those attitudes and beliefs, along with actual method-use experience, may affect potential choices in contraceptive method moving forward. The relationship of beliefs and attitudes to their risk-benefit calculations when using these methods was also considered.? METHODS: Women used one or more contraceptive methods, each for 3-6 months. Qualitative data from individual in-depth interviews completed after each 3-month use period were analysed using a summary matrix framework. Data were extracted and summarised into themes. Each woman's experiences were compared among the methods she used; comparisons were also made across participants. RESULTS: The data consist of 33 90-120 min in-depth qualitative interviews from 16 women aged 20-34 years, in which they discussed various elements of their method use experience. One prominent theme was identified: the influence of attitudes and beliefs on the risk-benefit calculus. There were six key elements within the theme: pregnancy prevention; dosing and the potential for user error; side-effects; familiarity; disclosure; and sexual partnerships. CONCLUSIONS: Women weighed perceived risks and benefits in their decision-making and, ultimately, their contraception choices. Understanding women's beliefs and attitudes that contribute to a calculation of risk-benefit can inform the development of sexual and reproductive health products.

Myofascial Flap Closure in Treatment for Patients With Craniocervical Instability and Ehlers-Danlos Syndrome.

INTRODUCTION: The benefits of decompression and fusion for patients with craniocervical instability are well described. However, complications such as wound breakdown and need for unplanned reoperation frequently occur. Recent studies have shown advantages of myofascial flap closure for various spinal procedures. This study investigated whether closure with myofascial flaps after surgery for craniocervical instability decreases complications with further subgroup analysis of patients with Ehlers-Danlos syndrome (EDS). METHODS: A retrospective review of patients presenting to Weill Cornell Medical Center from 2010 to 2017 for craniocervical surgery was performed. All patients who underwent craniocervical surgery, regardless of plastic surgical involvement, were included in the study. Data including patient demographics, comorbidities, EDS diagnosis, surgical history, complications, and follow-up information were collected and analyzed. RESULTS: Data from 57 patients were analyzed. Eighteen patients (31.6%) had craniocervical surgery without myofascial flap closure, whereas 39 (68.4%) had surgery with flap closure. In the nonflap group, 9 patients required unplanned reoperation (50%). In the flap group, there were 5 patients requiring unplanned reoperation (15%). For reoperation, the Fisher exact test 2-tailed P value is 0.0096. Of those 57 patients, 24 had EDS: 5 (20.8%) had no flap closure, whereas 19 (79.2%) had flap closure. In the no-flap group, 3 patients required unplanned reoperation (60%). In the flap group, 5 patients required unplanned reoperation (21%). For reoperation, the Fisher exact test 2-tailed P value is 0.1265. CONCLUSIONS: Patients undergoing surgery for craniocervical instability may benefit from myofascial flap closure even if they have EDS. Mobilizing well-vascularized tissue can decrease rates of reoperation.

The Effect of Topical Tacrolimus on Pedicled Flap Survival.

PURPOSE: Skin necrosis is a known postoperative complication of mastectomies. The pathophysiology of tissue necrosis involves lymphatic congestion, followed by venous congestion and ultimately arterial insufficiency. Recent mouse model studies have shown topical tacrolimus to increase growth of lymphatic collateral vessels and decrease lymphedema, potentially obviating the cycle of necrosis and increasing skin survival. The purpose of this study was to investigate the effect of topical tacrolimus on skin flap necrosis in a rat model. METHODS: A cranially based dorsal skin flap measuring 3 × 10 cm was raised and reinset on 22 Sprague-Dawley rats. They were then randomized to either the control (topical petroleum jelly) or the treatment (topical 0.1% tacrolimus) arm. In addition, 0.2 g of either ointment was spread over the flap and then covered with an occlusive dressing. Dressings were changed daily with reapplication of both the topical ointment and occlusive dressing. The rats were sacrificed 7 days postoperatively; areas of viable tissue, reversible ischemia, and full thickness necrosis were measured with Fiji software, and comparative analysis was performed with GraphPad statistical software. RESULTS: The average area of the dorsal flaps in the control and tacrolimus groups was 22.5 and 23.9 cm, respectively. In the control cohort, the average viable area was 42.4%, the average reversible ischemia area was 43.6%, and the average necrotic area was 13.9%. In the tacrolimus cohort, the average viable area was 31.5%, the average reversible ischemia area was 59.3%, and the average necrotic area was 9.2%. Total necrotic area was significantly lower in rats receiving topical tacrolimus as compared with controls (P = 0.015). Furthermore, the ratios of necrotic to reversible ischemia and necrotic to viable tissue were significantly lower in the tacrolimus group as compared with controls (P = 0.003, P = 0.015). There was one incidence of wound dehiscence secondary to rodent self-removal of dressings and suture that required reoperation and reinset. CONCLUSIONS: Topical tacrolimus was associated with significantly less full thickness necrosis as compared with topical.

Structure, Dynamics, and Reactivity for Light Alkane Oxidation of Fe(II) Sites Situated in the Nodes of a Metal-Organic Framework.

Metal organic frameworks (MOFs), with their crystalline, porous structures, can be synthesized to incorporate a wide range of catalytically active metals in tailored surroundings. These materials have potential as catalysts for conversion of light alkanes, feedstocks available in large quantities from shale gas that are changing the economics of manufacturing commodity chemicals. Mononuclear high-spin (S = 2) Fe(II) sites situated in the nodes of the MOF MIL-100(Fe) convert propane via dehydrogenation, hydroxylation, and overoxidation pathways in reactions with the atomic oxidant N2O. Pair distribution function analysis, N2 adsorption isotherms, X-ray diffraction patterns, and infrared and Raman spectra confirm the single-phase crystallinity and stability of MIL-100(Fe) under reaction conditions (523 K in vacuo, 378-408 K C3H8 + N2O). Density functional theory (DFT) calculations illustrate a reaction mechanism for the formation of 2-propanol, propylene, and 1-propanol involving the oxidation of Fe(II) to Fe(III) via a high-spin Fe(IV)═O intermediate. The speciation of Fe(II) and Fe(III) in the nodes and their dynamic interchange was characterized by in situ X-ray absorption spectroscopy and ex situ Mössbauer spectroscopy. The catalytic relevance of Fe(II) sites and the number of such sites were determined using in situ chemical titrations with NO. N2 and C3H6 production rates were found to be first-order in N2O partial pressure and zero-order in C3H8 partial pressure, consistent with DFT calculations that predict the reaction of Fe(II) with N2O to be rate determining. DFT calculations using a broken symmetry method show that Fe-trimer nodes affecting reaction contain antiferromagnetically coupled iron species, and  highlight the importance of stabilizing high-spin (S = 2) Fe(II) species for effecting alkane oxidation at low temperatures (<408 K).

Multiple Bonds in Uranium-Transition Metal Complexes.

Novel heterobimetallic complexes featuring a uranium atom paired with a first-row transition metal have been computationally predicted and analyzed using density functional theory and multireference wave function based methods. The synthetically inspired metalloligands U{(iPr2PCH2NAr)3tacn} (1) and U(iPr2PCH2NPh)3 (2) are explored in this study. We report the presence of multiple bonds between uranium and chromium, uranium and manganese, and uranium and iron. The calculations predict a 5-fold bonding between uranium and manganese in the UMn(iPr2PCH2NPh)3 complex, which is unprecedented in the literature.

Enhanced Fe-Centered Redox Flexibility in Fe-Ti Heterobimetallic Complexes.

Previously, we reported the synthesis of Ti[N( o-(NCH2P( iPr)2)C6H4)3] and the Fe-Ti complex, FeTi[N( o-(NCH2P( iPr)2)C6H4)3], abbreviated as TiL (1), and FeTiL (2), respectively. Herein, we describe the synthesis and characterization of the complete redox families of the monometallic Ti and Fe-Ti compounds. Cyclic voltammetry studies on FeTiL reveal both reduction and oxidation processes at -2.16 and -1.36 V (versus Fc/Fc+), respectively. Two isostructural redox members, [FeTiL]+ and [FeTiL]- (2ox and 2red, respectively) were synthesized and characterized, along with BrFeTiL (2-Br) and the monometallic [TiL]+ complex (1ox). The solid-state structures of the [FeTiL]+/0/- series feature short metal-metal bonds, ranging from 1.94-2.38 Å, which are all shorter than the sum of the Ti and Fe single-bond metallic radii (cf. 2.49 Å). To elucidate the bonding and electronic structures, the complexes were characterized with a host of spectroscopic methods, including NMR, EPR, and 57Fe Mössbauer, as well as Ti and Fe K-edge X-ray absorption spectroscopy (XAS). These studies, along with hybrid density functional theory (DFT) and time-dependent DFT calculations, suggest that the redox processes in the isostructural [FeTiL]+,0,- series are primarily Fe-based and that the polarized Fe-Ti π-bonds play a role in delocalizing some of the additional electron density from Fe to Ti (net 13%).