High Molar Mass Polycarbonates as Closed-Loop Recyclable Thermoplastics.

Using carbon dioxide (CO2) to make recyclable thermoplastics could reduce greenhouse gas emissions associated with polymer manufacturing. CO2/cyclic epoxide ring-opening copolymerization (ROCOP) allows for >30 wt % of the polycarbonate to derive from CO2; so far, the field has largely focused on oligocarbonates. In contrast, efficient catalysts for high molar mass polycarbonates are underinvestigated, and the resulting thermoplastic structure-property relationships, processing, and recycling need to be elucidated. This work describes a new organometallic Mg(II)Co(II) catalyst that combines high productivity, low loading tolerance, and the highest polymerization control to yield polycarbonates with number average molecular weight (Mn) values from 4 to 130 kg mol-1, with narrow, monomodal distributions. It is used in the ROCOP of CO2 with bicyclic epoxides to produce a series of samples, each with Mn > 100 kg mol-1, of poly(cyclohexene carbonate) (PCHC), poly(vinyl-cyclohexene carbonate) (PvCHC), poly(ethyl-cyclohexene carbonate) (PeCHC, by hydrogenation of PvCHC), and poly(cyclopentene carbonate) (PCPC). All these materials are amorphous thermoplastics, with high glass transition temperatures (85 < Tg < 126 °C, by differential scanning calorimetry) and high thermal stability (Td > 260 °C). The cyclic ring substituents mediate the materials' chain entanglements, viscosity, and glass transition temperatures. Specifically, PCPC was found to have 10× lower entanglement molecular weight (Me)n and 100× lower zero-shear viscosity compared to those of PCHC, showing potential as a future thermoplastic. All these high molecular weight polymers are fully recyclable, either by reprocessing or by using the Mg(II)Co(II) catalyst for highly selective depolymerizations to epoxides and CO2. PCPC shows the fastest depolymerization rates, achieving an activity of 2500 h-1 and >99% selectivity for cyclopentene oxide and CO2.

Chemical Recycling of Commercial Poly(l-lactic acid) to l-Lactide Using a High-Performance Sn(II)/Alcohol Catalyst System.

Poly(l-lactic acid) (PLLA) is a leading commercial polymer produced from biomass, showing useful properties for plastics and fiber applications; after use, it is compostable. One area for improvement is postconsumer waste PLLA chemical recycling to monomer (CRM), i.e., the formation of l-lactide (l-LA) from waste plastic. This process is currently feasible at high reaction temperatures and shows low catalytic activity accompanied, in some cases, by side reactions, including epimerization. Here, a commercial Sn(II) catalyst, applied with nonvolatile commercial alcohol, enables highly efficient CRM of PLLA to yield l-LA in excellent yield and purity (92% yield, >99% l-LA from theoretical max.). The depolymerization is performed using neat polymer films at low temperatures (160 °C) under a nitrogen flow or vacuum. The chemical recycling operates with outstanding activity, achieving turnover frequencies which are up to 3000× higher than previously excellent catalysts and applied at loadings up to 6000× lower than previously leading catalysts. The catalyst system achieves a TOF = 3000 h-1 at 0.01 mol % or 1:10,000 catalyst:PLLA loading. The depolymerization of waste PLLA plastic packaging (coffee cup lids) produces pure l-LA in excellent yield and selectivity. The new catalyst system (Sn + alcohol) can itself be recycled four times in different PLLA "batch degradations" and maintains its high catalytic productivity, activity, and selectivity.

A Chemoselective Polarity-Mismatched Photocatalytic C(sp3 )-C(sp2 ) Cross-Coupling Enabled by Synergistic Boron Activation.

We report the development of a C(sp3 )-C(sp2 ) coupling reaction using styrene boronic acids and redox-active esters under photoredox catalysis. The reaction proceeds through an unusual polarity-mismatched radical addition mechanism that is orthogonal to established processes. Synergistic activation of the radical precursor and organoboron are critical mechanistic events. Activation of an N-hydroxyphthalimide (NHPI) ester by coordination to boron enables electron transfer, with decomposition leading to a nucleofuge rebound, activating the organoboron to radical addition. The unique mechanism enables chemoselective coupling of styrene boronic acids in the presence of other alkene radical acceptors. The scope and limitations of the reaction, and a detailed mechanistic investigation are presented.

Solid-State Chemical Recycling of Polycarbonates to Epoxides and Carbon Dioxide Using a Heterodinuclear Mg(II)Co(II) Catalyst.

Polymer chemical recycling to monomers (CRM) could help improve polymer sustainability, but its implementation requires much better understanding of depolymerization catalysis, ensuring high rates and selectivity. Here, a heterodinuclear [Mg(II)Co(II)] catalyst is applied for CRM of aliphatic polycarbonates, including poly(cyclohexene carbonate) (PCHC), to epoxides and carbon dioxide using solid-state conditions, in contrast with many other CRM strategies that rely on high dilution. The depolymerizations are performed in the solid state giving very high activity and selectivity (PCHC, TOF = 25700 h-1, CHO selectivity >99 %, 0.02 mol %, 140 °C). Reactions may also be performed in air without impacting on the rate or selectivity of epoxide formation. The depolymerization can be performed on a 2 g scale to isolate the epoxides in up to 95 % yield with >99 % selectivity. In addition, the catalyst can be re-used four times without compromising its productivity or selectivity.

An Enantioselective Suzuki-Miyaura Coupling To Form Axially Chiral Biphenols.

Axial chirality features prominently in molecules of biological interest as well as chiral catalyst designs, and atropisomeric 2,2'-biphenols are particularly prevalent. Atroposelective metal-catalyzed cross-coupling is an attractive and modular approach to access enantioenriched biphenols, and yet existing protocols cannot achieve this directly. We address this challenge through the use of enantiopure, sulfonated SPhos (sSPhos), an existing ligand that has until now been used only in racemic form and that derives its chirality from an atropisomeric axis that is introduced through sulfonation. We believe that attractive noncovalent interactions involving the ligand sulfonate group are responsible for the high levels of asymmetric induction that we obtain in the 2,2'-biphenol products of Suzuki-Miyaura coupling, and we have developed a highly practical resolution of sSPhos via diastereomeric salt recrystallization.

Racial/Ethnic Disparities in Substance Use Treatment in Medicaid Managed Care in New York City: The Role of Plan and Geography.

OBJECTIVE: The aim was to assess the magnitude of health care disparities in treatment for substance use disorder (SUD) and the role of health plan membership and place of residence in observed disparities in Medicaid Managed Care (MMC) plans in New York City (NYC). DATA SOURCE: Medicaid claims and managed care plan enrollment files for 2015-2017 in NYC. RESEARCH DESIGN: We studied Medicaid enrollees with a SUD diagnosis during their first 6 months of enrollment in a managed care plan in 2015-2017. A series of linear regression models quantified service disparities across race/ethnicity for 5 outcome indicators: treatment engagement, receipt of psychosocial treatment, follow-up after withdrawal, rapid readmission, and treatment continuation. We assessed the degree to which plan membership and place of residence contributed to observed disparities. RESULTS: We found disparities in access to treatment but the magnitude of the disparities in most cases was small. Plan membership and geography of residence explained little of the observed disparities. One exception is geography of residence among Asian Americans, which appears to mediate disparities for 2 of our 5 outcome measures. CONCLUSIONS: Reallocating enrollees among MMC plans in NYC or evolving trends in group place of residence are unlikely to reduce disparities in treatment for SUD. System-wide reforms are needed to mitigate disparities.

Chemical Recycling of Poly(Cyclohexene Carbonate) Using a Di-MgII Catalyst.

Chemical recycling of polymers to true monomers is pivotal for a circular plastics economy. Here, the first catalyzed chemical recycling of the widely investigated carbon dioxide derived polymer, poly(cyclohexene carbonate), to cyclohexene oxide and carbon dioxide is reported. The reaction requires dinuclear catalysis, with the di-MgII catalyst showing both high monomer selectivity (>98 %) and activity (TOF=150 h-1 , 0.33 mol %, 120 °C). The depolymerization occurs via a chain-end catalyzed depolymerization mechanism and DFT calculations indicate the high selectivity arises from Mg-alkoxide catalyzed epoxide extrusion being kinetically favorable compared to cyclic carbonate formation.

The Evolution of Supply and Demand in Markets for Generic Drugs.

Policy Points Much concern about generic drug markets has emerged in recent policy debates. Important changes in regulations, the structure of purchasing, and the length of the drug supply chain have affected generic drug markets. Effective price competition remains the rule in generic markets for large-selling drugs. Smaller markets and those for injectable products often have less price competition and are more susceptible to supply disruptions. CONTEXT: The image of generic drugs as a commodity sold in competitive markets is an oversimplification, as evidenced by increasing accounts of price spikes, sustained high price-cost margins, and market disruptions. The mismatch between the canonical economic model of generic drug markets and reality motivated our empirical project. METHODS: To explore recent changes in those factors impacting the supply and demand for generic drugs, we studied, from a variety of sources, the data on price, competition, supply disruptions and recalls, changes to the supply chain, and buy-side concentration. We examined quarterly data through 2018 for a cohort of 77 molecules that lost patent protection during the so-called patent cliff between 2010 and 2013. FINDINGS: On the supply side, we found that for large-market oral solids, generic entry and price declines were consistent with past studies showing a significant number of market entrants and substantial reductions in the average price of a molecule. In smaller markets for oral solids and injectable products, we observed fewer entrants, higher rates of exit, smaller price reductions, and, in some cases, considerable price instability. The number of reported shortages increased across all generic market types over time, with the rate of shortage increases especially pronounced in markets for injectable products. The number of product recalls also rose over our study period. Although we did not estimate causal effects, we did find several changes in the market environment for generic drugs that may contribute to these phenomena. The demand side for generics has become more concentrated. Supply chains rely more on producers outside the United States (particularly from China and India). Contracting practices have undergone changes that may inhibit competition in product supply. FDA regulatory scruitiny has increased. CONCLUSIONS: Competition in generic drug markets varies widely by market size and product form. Recent changes in demand-side market structure imply more downward pressure on prices stemming from buy-side concentration. The FDA's greater regulatory oversight puts upward pressure on costs, and the lengthening of the supply chain increases production uncertainty for producers. Demand and supply-side changes point to further market instabilities across all generic markets due to producers' changing economic position.

Control of Crystallinity and Stereocomplexation of Synthetic Carbohydrate Polymers from d- and l-Xylose.

Manipulating the stereochemistry of polymers is a powerful method to alter their physical properties. Despite the chirality of monosaccharides, reports on the impact of stereochemistry in natural polysaccharides and synthetic carbohydrate polymers remain absent. Herein, we report the cocrystallisation of regio- and stereoregular polyethers derived from d- and l-xylose, leading to enhanced thermal properties compared to the enantiopure polymers. To the best of our knowledge, this is the first example of a stereocomplex between carbohydrate polymers of opposite chirality. In contrast, atactic polymers obtained from a racemic mixture of monomers are amorphous. We also show that the polymer hydroxyl groups are amenable to post-polymerisation functionalization. These strategies afford a family of carbohydrate polyethers, the physical and chemical properties of which can both be controlled, and which opens new possibilities for polysaccharide mimics in biomedical applications or as advanced materials.

Cu(OTf)2 -Mediated Cross-Coupling of Nitriles and N-Heterocycles with Arylboronic Acids to Generate Nitrilium and Pyridinium Products*.

Metal-catalyzed C-N cross-coupling generally forms C-N bonds by reductive elimination from metal complexes bearing covalent C- and N-ligands. We have identified a Cu-mediated C-N cross-coupling that uses a dative N-ligand in the bond-forming event, which, in contrast to conventional methods, generates reactive cationic products. Mechanistic studies suggest the process operates via transmetalation of an aryl organoboron to a CuII complex bearing neutral N-ligands, such as nitriles or N-heterocycles. Subsequent generation of a putative CuIII complex enables the oxidative C-N coupling to take place, delivering nitrilium intermediates and pyridinium products. The reaction is general for a range of N(sp) and N(sp2 ) precursors and can be applied to drug synthesis and late-stage N-arylation, and the limitations in the methodology are mechanistically evidenced.

Divergent Catalytic Strategies for the Cis/Trans Stereoselective Ring-Opening Polymerization of a Dual Cyclic Carbonate/Olefin Monomer.

A dual seven-membered cyclic carbonate/olefin monomer was synthesized from CO2 and cis-1,4-butenediol and polymerized. The properties of the polymer were controlled using divergent catalytic strategies toward the stereochemistry of the olefin. Ring-opening polymerization of the cyclic carbonate using an organocatalytic approach retained the cis-stereoconfiguration of the olefin and yielded a hard semicrystalline polymer (Tm 115 °C). Ring-opening metathesis polymerization using Grubbs' catalyst proceeded with high trans-stereoregularity (95%) and produced a soft amorphous polymer (Tg -22 °C). Cis to trans isomerization of the polymer was possible using Cu(I) salts under UV light. In all polymers, the C═C double bond remained available for postpolymerization modification and thermoset resins were formed by cross-linking. From this single monomer, cis-trans-cis triblock copolymers, with potential applications as thermoplastic elastomers, were synthesized by combining both strategies using cis-1,4-butenediol as a chain transfer agent.

Market Concentration and Potential Competition in Medicare Advantage.

Issue: Medicare Advantage (MA), the private option to traditional Medicare, now serves roughly 37 percent of beneficiaries. Congress intended MA plans to achieve efficiencies in the provision of health care that lead to savings for Medicare through managed competition among private health plans. Goal: Two elements are needed for savings to accrue: a sound payment policy and effective competition among the private plans. This brief examines the latter. Methods: We use data from 2009­17 to describe market structure in MA, including the insurers offering plans and enrollment in each U.S. county. We measure both actual and potential competitors for each county for each year. Key Findings and Conclusions: MA markets are highly concentrated and have become more concentrated since 2009. From 2009­17, 70 percent or more of enrollees were in highly concentrated markets, dominated by two or three insurers. Since the payment system used to reimburse insurers selling in the MA market relies on competition to spur efficiency and premiums that more closely reflect insurers' actual costs, these developments suggest that taxpayers and beneficiaries will overpay. We also find an average of six potential entrants into MA markets, which points to a source of competition that may be activated in MA. To tap into potential competition, further research is needed to understand the factors affecting entry into MA markets.

Electron Transfer Reactions: KO tBu (but not NaO tBu) Photoreduces Benzophenone under Activation by Visible Light.

Long-standing controversial reports of electron transfer from KO tBu to benzophenone have been investigated and resolved. The mismatch in the oxidation potential of KO tBu (+0.10 V vs SCE in DMF) and the first reduction potential of benzophenone (of many values cited in the literature, the least negative value is -1.31 V vs SCE in DMF), preclude direct electron transfer. Experimental and computational results now establish that a complex is formed between the two reagents, with the potassium ion providing the linkage, which markedly shifts the absorption spectrum to provide a tail in the visible light region. Photoactivation at room temperature by irradiation at defined wavelength (365 or 400 nm), or even by winter daylight, leads to the development of the blue color of the potassium salt of benzophenone ketyl, whereas no reaction is observed when the reaction mixture is maintained in darkness. So, no electron transfer occurs in the ground state. However, when photoexcited, electron transfer occurs within a complex formed from benzophenone and KO tBu. TDDFT studies match experimental findings and also define the electronic transition within the complex as n → π*, originating on the butoxide oxygen. Computation and experiment also align in showing that this reaction is selective for KO tBu; no such effect occurs with NaO tBu, providing the first case where such alkali metal ion selectivity is rationalized in detail. Chemical evidence is provided for the photoactivated electron transfer from KO tBu to benzophenone: tert-butoxyl radicals are formed and undergo fragmentation to form (acetone and) methyl radicals, some of which are trapped by benzophenone. Likewise, when KOC(Et)3 is used in place of KO tBu, then ethylation of benzophenone is seen. Further evidence of electron transfer was seen when the reaction was conducted in benzene, in the presence of p-iodotoluene; this triggered BHAS coupling to form 4-methylbiphenyl in 74% yield.

Dual Roles for Potassium Hydride in Haloarene Reduction: CSNAr and Single Electron Transfer Reduction via Organic Electron Donors Formed in Benzene.

Potassium hydride behaves uniquely and differently than sodium hydride toward aryl halides. Its reactions with a range of haloarenes, including designed 2,6-dialkylhaloarenes, were studied in THF and in benzene. In THF, evidence supports concerted nucleophilic aromatic substitution, CSNAr, and the mechanism originally proposed by Pierre et al. is now validated through DFT studies. In benzene, besides this pathway, strong evidence for single electron transfer chemistry is reported. Experimental observations and DFT studies lead us to propose organic super electron donor generation to initiate BHAS (base-promoted homolytic aromatic substitution) cycles. Organic donor formation originates from deprotonation of benzene by KH; attack on benzene by the resulting phenylpotassium generates phenylcyclohexadienylpotassium that can undergo (i) deprotonation to form an organic super electron donor or (ii) hydride loss to afford biphenyl. Until now, BHAS reactions have been triggered by reaction of a base, MO tBu (M = K, Na), with many different types of organic additive, all containing heteroatoms (N or O or S) that enhance their acidity and place them within range of MO tBu as a base. This paper shows that with the stronger base, KH, even a hydrocarbon (benzene) can be converted into an electron-donating initiator.

KOtBu: A Privileged Reagent for Electron Transfer Reactions?

Many recent studies have used KOtBu in organic reactions that involve single electron transfer; in the literature, the electron transfer is proposed to occur either directly from the metal alkoxide or indirectly, following reaction of the alkoxide with a solvent or additive. These reaction classes include coupling reactions of halobenzenes and arenes, reductive cleavages of dithianes, and SRN1 reactions. Direct electron transfer would imply that alkali metal alkoxides are willing partners in these electron transfer reactions, but the literature reports provide little or no experimental evidence for this. This paper examines each of these classes of reaction in turn, and contests the roles proposed for KOtBu; instead, it provides new mechanistic information that in each case supports the in situ formation of organic electron donors. We go on to show that direct electron transfer from KOtBu can however occur in appropriate cases, where the electron acceptor has a reduction potential near the oxidation potential of KOtBu, and the example that we use is CBr4. In this case, computational results support electrochemical data in backing a direct electron transfer reaction.

Synthesis of Azabicycles via Cascade Aza-Prins Reactions: Accessing the Indolizidine and Quinolizidine Cores.

The first detailed studies of intramolecular aza-Prins and aza-silyl-Prins reactions, starting from acyclic materials, are reported. The methods allow rapid and flexible access toward an array of [6,5] and [6,6] aza-bicycles, which form the core skeletons of various alkaloids. On the basis of our findings on the aza-Prins and aza-silyl-Prins cyclizations, herein we present simple protocols for the intramolecular preparation of the azabicyclic cores of the indolizidines and quinolizidines using a one-pot cascade process of N-acyliminium ion formation followed by aza-Prins cyclization and either elimination or carbocation trapping. It is possible to introduce a range of different substituents into the heterocycles through a judicial choice of Lewis acid and solvent(s), with halo-, phenyl-, and amido-substituted azabicyclic products all being accessed through these highly diastereoselective processes.

Thirty-Day Hospital Readmission for Medicaid Enrollees with Schizophrenia: The Role of Local Health Care Systems.

BACKGROUND: Examining health care system characteristics possibly associated with 30-day readmission may reveal opportunities to improve healthcare quality as well as reduce costs. AIMS OF THE STUDY: Examine the relationship between 30-day mental health readmission for persons with schizophrenia and county-level community treatment characteristics. METHODS: Observational study of 18 state Medicaid programs (N=274 counties, representing 103,967 enrollees with schizophrenia 28,083 of whom received more than 1 mental health hospitalization) using Medicaid administrative and United States Area Health Resource File data from 2005. Medicaid is a federal-state program and major health insurance provider for low income and disabled individuals, and the predominant provider of insurance for individuals with schizophrenia. The Area Health Resource File provides county-level estimates of providers. We first fit a regression model examining the relationship between 30-day mental health readmission and enrollee characteristics (e.g., demographics, substance use disorder [SUD], and general medical comorbidity) from which we created a county-level demographic and comorbidity case-mix adjuster. The case-mix adjuster was included in a second regression model examining the relationship between 30-day readmission and county-level factors: (i) quality (antipsychotic/visit continuity, post-hospital follow-up); (ii) mental health hospitalization (length of stay, admission rates); and (iii) treatment capacity (e.g., population-based estimates of outpatient providers/clinics). We calculated predicted probabilities of readmission for significant patient and county-level variables. RESULTS: Higher county rates of mental health visits within 7-days post-hospitalization were associated with lower readmission probabilities (e.g., county rates of 7-day follow up of 55% versus 85%, readmission predicted probability (PP) [95%CI]=16.1% [15.8%-16.4%] versus 13.3% [12.9%-13.6%]). In contrast, higher county rates of mental health hospitalization were associated with higher readmission probabilities (e.g., country admission rates 10% versus 30%, readmission predicted probability=11.3% [11.0%-11.6%] versus 16.7% [16.4%-17.0%]). Although not our primary focus, enrollee comorbidity was associated with higher predicted probability of 30-day mental health readmission: PP [95%CI] for enrollees with SUD=23.9% [21.5%-26.3%] versus 14.7% [13.9%-15.4%] for those without; PP [95% CI] for those with=three chronic medical conditions=25.1% [22.1%-28.2%] versus none=17.7% [16.3%-19.1]. DISCUSSION: County rates of hospitalization and 7-day follow-up post hospital discharge were associated with readmission, along with patient SUD and general medical comorbidity. This observational design limits causal inference and utilization patterns may have changed since 2005. However, overall funding for U.S. Medicaid programs remained constant since 2005, reducing the likelihood significant changes. Last, our inability to identify community capacity variables associated with readmission may reflect imprecision of some variables as measured in the Area Health Resource File. IMPLICATIONS FOR HEALTH CARE PROVISION AND USE AND FOR HEALTH POLICIES: Healthcare policy and programming to reduce 30-day mental health readmissions should focus on county-level factors that contribute to hospitalization in general and improving transitions to community care, as well as patient comorbidity. IMPLICATIONS FOR FURTHER RESEARCH: Given the likely importance of local care systems, to reduce readmission future research is needed to refine community-level capacity variables that are associated with reduced readmissions; and to evaluate models of care coordination in this population.

How successful is Medicare Advantage?

CONTEXT: Medicare Part C, or Medicare Advantage (MA), now almost 30 years old, has generally been viewed as a policy disappointment. Enrollment has vacillated but has never come close to the penetration of managed care plans in the commercial insurance market or in Medicaid, and because of payment policy decisions and selection, the MA program is viewed as having added to cost rather than saving funds for the Medicare program. Recent changes in Medicare policy, including improved risk adjustment, however, may have changed this picture. METHODS: This article summarizes findings from our group's work evaluating MA's recent performance and investigating payment options for improving its performance even more. We studied the behavior of both beneficiaries and plans, as well as the effects of Medicare policy. FINDINGS: Beneficiaries make "mistakes" in their choice of MA plan options that can be explained by behavioral economics. Few beneficiaries make an active choice after they enroll in Medicare. The high prevalence of "zero-premium" plans signals inefficiency in plan design and in the market's functioning. That is, Medicare premium policies interfere with economically efficient choices. The adverse selection problem, in which healthier, lower-cost beneficiaries tend to join MA, appears much diminished. The available measures, while limited, suggest that, on average, MA plans offer care of equal or higher quality and for less cost than traditional Medicare (TM). In counties, greater MA penetration appears to improve TM's performance. CONCLUSIONS: Medicare policies regarding lock-in provisions and risk adjustment that were adopted in the mid-2000s have mitigated the adverse selection problem previously plaguing MA. On average, MA plans appear to offer higher value than TM, and positive spillovers from MA into TM imply that reimbursement should not necessarily be neutral. Policy changes in Medicare that reform the way that beneficiaries are charged for MA plan membership are warranted to move more beneficiaries into MA.

Alternatives to fluorinated binders: recyclable copolyester/carbonate electrolytes for high-capacity solid composite cathodes.

Optimising the composite cathode for next-generation, safe solid-state batteries with inorganic solid electrolytes remains a key challenge towards commercialisation and cell performance. Tackling this issue requires the design of suitable polymer binders for electrode processability and long-term solid-solid interfacial stability. Here, block-polyester/carbonates are systematically designed as Li-ion conducting, high-voltage stable binders for cathode composites comprising of single-crystal LiNi0.8Mn0.1Co0.1O2 cathodes, Li6PS5Cl solid electrolyte and carbon nanofibres. Compared to traditional fluorinated polymer binders, improved discharge capacities (186 mA h g-1) and capacity retention (96.7% over 200 cycles) are achieved. The nature of the new binder electrolytes also enables its separation and complete recycling after use. ABA- and AB-polymeric architectures are compared where the A-blocks are mechanical modifiers, and the B-block facilitates Li-ion transport. This reveals that the conductivity and mechanical properties of the ABA-type are more suited for binder application. Further, catalysed switching between CO2/epoxide A-polycarbonate (PC) synthesis and B-poly(carbonate-r-ester) formation employing caprolactone (CL) and trimethylene carbonate (TMC) identifies an optimal molar mass (50 kg mol-1) and composition (wPC 0.35). This polymer electrolyte binder shows impressive oxidative stability (5.2 V), suitable ionic conductivity (2.2 × 10-4 S cm-1 at 60 °C), and compliant viscoelastic properties for fabrication into high-performance solid composite cathodes. This work presents an attractive route to optimising polymer binder properties using controlled polymerisation strategies combining cyclic monomer (CL, TMC) ring-opening polymerisation and epoxide/CO2 ring-opening copolymerisation. It should also prompt further examination of polycarbonate/ester-based materials with today's most relevant yet demanding high-voltage cathodes and sensitive sulfide-based solid electrolytes.

Scope and Incentives for Risk Selection in Health Insurance Markets With Regulated Competition: A Conceptual Framework and International Comparison.

In health insurance markets with regulated competition, regulators face the challenge of preventing risk selection. This paper provides a framework for analyzing the scope (i.e., potential actions by insurers and consumers) and incentives for risk selection in such markets. Our approach consists of three steps. First, we describe four types of risk selection: (a) selection by consumers in and out of the market, (b) selection by consumers between high- and low-value plans, (c) selection by insurers via plan design, and (d) selection by insurers via other channels such as marketing, customer service, and supplementary insurance. In a second step, we develop a conceptual framework of how regulation and features of health insurance markets affect the scope and incentives for risk selection along these four dimensions. In a third step, we use this framework to compare nine health insurance markets with regulated competition in Australia, Europe, Israel, and the United States.