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  1. Artikel: An Immobilized (Carbene)Nickel Catalyst for Water Oxidation.

    Lu, Zhiyao / Mitra, Debanjan / Narayan, Sri R / Williams, Travis J

    Polyhedron

    2024  Band 252

    Abstract: The oxygen evolution reaction (OER) of water splitting is essential to electrochemical energy storage applications. While nickel electrodes are widely available heterogeneous OER catalysts, homogeneous nickel catalysts for OER are underexplored. Here we ... ...

    Abstract The oxygen evolution reaction (OER) of water splitting is essential to electrochemical energy storage applications. While nickel electrodes are widely available heterogeneous OER catalysts, homogeneous nickel catalysts for OER are underexplored. Here we report two carbene-ligated nickel(II) complexes that are exceptionally robust and efficient homogeneous water oxidation catalysts. Remarkably, these novel nickel complexes can assemble a stable thin film onto a metal electrode through poly-imidazole bridges, making them supported heterogeneous electrochemical catalysts that are resilient to leaching and stripping. Unlike molecular catalysts and nanoparticle catalysts, such electrode-supported metal-complex catalysts for OER are rare and have the potential to inspire new designs. The electrochemical OER with our nickel-carbene catalysts exhibits excellent current densities with high efficiency, low Tafel slope, and useful longevity for a base metal catalyst. Our data show that imidazole carbene ligands stay bonded to the nickel(II) centers throughout the catalysis, which allows the facile oxygen evolution.
    Sprache Englisch
    Erscheinungsdatum 2024-02-08
    Erscheinungsland England
    Dokumenttyp Journal Article
    ZDB-ID 2000326-2
    ISSN 0277-5387
    ISSN 0277-5387
    DOI 10.1016/j.poly.2024.116880
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  2. Artikel ; Online: Association Between the Medicare Advantage Quartile Adjustment System and Plan Behavior and Enrollment.

    Murray, Roslyn C / Meyers, David J / Fuse Brown, Erin C / Williams, Travis C / Ryan, Andrew M

    JAMA health forum

    2024  Band 5, Heft 1, Seite(n) e234822

    Abstract: Importance: Medicare Advantage (MA) has grown in popularity, but critics believe that insurers are overpaid, partially due to the quartile adjustment system that determines plan benchmarks. However, elimination of the quartile adjustments may be ... ...

    Abstract Importance: Medicare Advantage (MA) has grown in popularity, but critics believe that insurers are overpaid, partially due to the quartile adjustment system that determines plan benchmarks. However, elimination of the quartile adjustments may be associated with less generous benefits and fewer plan offerings, which could slow MA enrollment growth.
    Objective: To examine whether the quartile adjustment system is associated with differences in county-level benefits, insurer offerings, and MA enrollment.
    Design, setting, and participants: The quartile adjustments create discontinuous jumps in county-level base payments based on historical traditional Medicare spending. Data from January 2017 to December 2021 and a regression discontinuity design were used to examine changes in insurer behavior and MA enrollment between quartiles. The analytic sample included 1557 county observations.
    Main outcomes and measures: Study outcomes included monthly premiums, the share of plans charging premiums, primary care copayments, the share of plans using rebates to reduce Part B premiums, supplemental benefits, plan and contract availability, and MA enrollment.
    Results: Discontinuities were found in the quartile adjustments and benchmarks. A 1-percentage point (pp) increase in the quartile adjustment was associated with a $6.36 increase in monthly benchmarks (95% CI, 5.10-7.62), a $0.51 decrease in monthly premiums (95% CI, -0.96 to -0.07), and a 0.68 pp decrease in the share of plans charging premiums (95% CI, -1.25 to -0.10). Significant changes were not found in primary care copayments (-$0.04; 95% CI, -0.17 to 0.09), the share of plans using rebates to reduce Part B premiums (-0.17 pp; 95% CI, -0.34 to 0.01), supplemental benefits (eg, preventive dental coverage; 0.17 pp; 95% CI, -0.25 to 0.0), the number of plans (1.06; 95% CI, -3.44 to 5.57) or contracts (0.31; 95% CI, -0.18 to 0.81), or the MA enrollment rate (0.16 pp; 95% CI, -0.61 to 0.94).
    Conclusions and relevance: The study results suggest that MA plans are not very sensitive to modest changes in payment rates. Modifications to the quartile adjustment system may generate savings without substantially affecting MA beneficiaries.
    Mesh-Begriff(e) United States ; Medicare Part C ; Benchmarking
    Sprache Englisch
    Erscheinungsdatum 2024-01-05
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 2689-0186
    ISSN (online) 2689-0186
    DOI 10.1001/jamahealthforum.2023.4822
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  3. Artikel ; Online: An ambient pressure, direct hydrogenation of ketones.

    Zhang, Long / Lu, Zhiyao / Rander, Andrew R / Williams, Travis J

    Chemical communications (Cambridge, England)

    2023  Band 59, Heft 52, Seite(n) 8107–8110

    Abstract: We report two bifunctional (pyridyl)carbene-iridium(I) complexes that catalyze ketone and aldehyde hydrogenation at ambient pressure. Aryl, heteroaryl, and alkyl groups are demonstrated, and mechanistic studies reveal an unusual polarization effect in ... ...

    Abstract We report two bifunctional (pyridyl)carbene-iridium(I) complexes that catalyze ketone and aldehyde hydrogenation at ambient pressure. Aryl, heteroaryl, and alkyl groups are demonstrated, and mechanistic studies reveal an unusual polarization effect in which the rate is dependant of proton, rather than hydride, transfer. This method introduces a convenient, waste-free alternative to traditional borohydride and aluminum hydride reagents.
    Sprache Englisch
    Erscheinungsdatum 2023-06-27
    Erscheinungsland England
    Dokumenttyp Journal Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/d3cc01014g
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  4. Artikel: A rapid electrochemical method to recycle carbon fiber composites using methyl radicals.

    Yu, Zehan / Lim, Y Justin / Williams, Travis / Nutt, Steven

    Green chemistry : an international journal and green chemistry resource : GC

    2023  Band 25, Heft 18, Seite(n) 7058–7061

    Abstract: We introduce an electrochemical approach to recycle carbon fiber (CF) fabrics from amine-epoxy carbon fiber-reinforced polymers (CFRPs). Our novel method utilizes a Kolbe-like mechanism to generate methyl radicals from ... ...

    Abstract We introduce an electrochemical approach to recycle carbon fiber (CF) fabrics from amine-epoxy carbon fiber-reinforced polymers (CFRPs). Our novel method utilizes a Kolbe-like mechanism to generate methyl radicals from CH
    Sprache Englisch
    Erscheinungsdatum 2023-07-27
    Erscheinungsland England
    Dokumenttyp Journal Article
    ZDB-ID 2006274-6
    ISSN 1463-9270 ; 1463-9262
    ISSN (online) 1463-9270
    ISSN 1463-9262
    DOI 10.1039/d3gc01765f
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  5. Artikel: Cloacal Swabs Are Unreliable Sources for Estimating Lower Gastro-Intestinal Tract Microbiota Membership and Structure in Broiler Chickens.

    Williams, Travis / Athrey, Giridhar

    Microorganisms

    2020  Band 8, Heft 5

    Abstract: The gastrointestinal microbiota of chickens plays a central role in health and performance. Cloacal swabs, due to their proximity to the ceca (a vital site of functional activity), are an alternative, non-invasive method used for assaying microbial ... ...

    Abstract The gastrointestinal microbiota of chickens plays a central role in health and performance. Cloacal swabs, due to their proximity to the ceca (a vital site of functional activity), are an alternative, non-invasive method used for assaying microbial communities and might be a viable option for longitudinal studies. In this study, the microbiota of twenty paired cecal content and cloacal swab samples representing two dietary treatments was assessed using 16S rRNA V4 hypervariable region sequencing and was analyzed using the MOTHUR pipeline, Phyloseq, and Vegan packages. Paired t-test and Wilcoxon signed-rank tests showed significant differences in the Chao1 index (
    Sprache Englisch
    Erscheinungsdatum 2020-05-12
    Erscheinungsland Switzerland
    Dokumenttyp Journal Article
    ZDB-ID 2720891-6
    ISSN 2076-2607
    ISSN 2076-2607
    DOI 10.3390/microorganisms8050718
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  6. Artikel: Cloacal Swabs Are Unreliable Sources for Estimating Lower Gastro-Intestinal Tract Microbiota Membership and Structure in Broiler Chickens

    Williams, Travis / Athrey, Giridhar

    Microorganisms. 2020 May 12, v. 8, no. 5

    2020  

    Abstract: The gastrointestinal microbiota of chickens plays a central role in health and performance. Cloacal swabs, due to their proximity to the ceca (a vital site of functional activity), are an alternative, non-invasive method used for assaying microbial ... ...

    Abstract The gastrointestinal microbiota of chickens plays a central role in health and performance. Cloacal swabs, due to their proximity to the ceca (a vital site of functional activity), are an alternative, non-invasive method used for assaying microbial communities and might be a viable option for longitudinal studies. In this study, the microbiota of twenty paired cecal content and cloacal swab samples representing two dietary treatments was assessed using 16S rRNA V4 hypervariable region sequencing and was analyzed using the MOTHUR pipeline, Phyloseq, and Vegan packages. Paired t-test and Wilcoxon signed-rank tests showed significant differences in the Chao1 index (p-value <0.0001 and p-value <0.0001, respectively) but not in the Inverse Simpson species diversity estimator (p-value = 0.06763 and p-value = 0.06021, respectively) between the cecal content and cloacal swabs. β-diversity between the cloacal swabs and cecal microbiota also showed significant differences using PERMANOVA, HOMOVA, and weighted UniFrac testing (p-values < 0.001). Based on a paired sample analysis, this study provided evidence of the high inter-individual variation and randomness of cloacal microbiota, in contrast to cecal microbiota. Our findings indicated that cloacal swabs do not approximate the α or β diversity of cecal samples and are not suitable for longitudinal studies of gut microbiota.
    Schlagwörter cloaca ; digestive tract ; intestinal microorganisms ; species diversity ; t-test ; vegan diet
    Sprache Englisch
    Erscheinungsverlauf 2020-0512
    Erscheinungsort Multidisciplinary Digital Publishing Institute
    Dokumenttyp Artikel
    ZDB-ID 2720891-6
    ISSN 2076-2607
    ISSN 2076-2607
    DOI 10.3390/microorganisms8050718
    Datenquelle NAL Katalog (AGRICOLA)

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  7. Artikel ; Online: Legislative and Regulatory Options for Improving Medicare Advantage.

    Fuse Brown, Erin C / Williams, Travis C / Murray, Roslyn C / Meyers, David J / Ryan, Andrew M

    Journal of health politics, policy and law

    2023  Band 48, Heft 6, Seite(n) 919–950

    Abstract: The Medicare Advantage program was created to expand beneficiary choice and to reduce spending through capitated payment to private insurers. However, many stakeholders now argue that Medicare Advantage is failing to deliver on its promise to reduce ... ...

    Abstract The Medicare Advantage program was created to expand beneficiary choice and to reduce spending through capitated payment to private insurers. However, many stakeholders now argue that Medicare Advantage is failing to deliver on its promise to reduce spending. Three problematic design features in Medicare Advantage payment policy have received particular scrutiny: (1) how baseline payments to insurers are determined, (2) how variation in patient risk affects insurer payment, and (3) how payments to insurers are adjusted for quality performance. The authors analyze the statute underlying these three design features and explore legislative and regulatory strategies for improving Medicare Advantage. They conclude that regulatory approaches for improving risk adjustment and for recouping overpayments from risk-score gaming have the highest potential impact and are the most feasible improvement measures to implement.
    Mesh-Begriff(e) Aged ; Humans ; United States ; Medicare Part C ; Policy
    Sprache Englisch
    Erscheinungsdatum 2023-07-26
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ZDB-ID 752966-1
    ISSN 1527-1927 ; 0361-6878
    ISSN (online) 1527-1927
    ISSN 0361-6878
    DOI 10.1215/03616878-10852628
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  8. Artikel ; Online: Quantitation of Oncologic Image Features for Radiomic Analyses in PET.

    Williams, Travis L / Gonen, Mithat / Wray, Rick / Do, Richard K G / Simpson, Amber L

    Methods in molecular biology (Clifton, N.J.)

    2023  Band 2729, Seite(n) 409–421

    Abstract: Radiomics is an emerging and exciting field of study involving the extraction of many quantitative features from radiographic images. Positron emission tomography (PET) images are used in cancer diagnosis and staging. Utilizing radiomics on PET images ... ...

    Abstract Radiomics is an emerging and exciting field of study involving the extraction of many quantitative features from radiographic images. Positron emission tomography (PET) images are used in cancer diagnosis and staging. Utilizing radiomics on PET images can better quantify the spatial relationships between image voxels and generate more consistent and accurate results for diagnosis, prognosis, treatment, etc. This chapter gives the general steps a researcher would take to extract PET radiomic features from medical images and properly develop models to implement.
    Mesh-Begriff(e) Image Processing, Computer-Assisted/methods ; Positron-Emission Tomography
    Sprache Englisch
    Erscheinungsdatum 2023-11-25
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1940-6029
    ISSN (online) 1940-6029
    DOI 10.1007/978-1-0716-3499-8_23
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  9. Artikel ; Online: APE2 Promotes AID-Dependent Somatic Hypermutation in Primary B Cell Cultures That Is Suppressed by APE1.

    Schrader, Carol E / Williams, Travis / Pechhold, Klaus / Linehan, Erin K / Tsuchimoto, Daisuke / Nakabeppu, Yusaku

    Journal of immunology (Baltimore, Md. : 1950)

    2023  Band 210, Heft 11, Seite(n) 1804–1814

    Abstract: Somatic hypermutation (SHM) is necessary for Ab diversification and involves error-prone DNA repair of activation-induced cytidine deaminase-induced lesions in germinal center (GC) B cells but can also cause genomic instability. GC B cells express low ... ...

    Abstract Somatic hypermutation (SHM) is necessary for Ab diversification and involves error-prone DNA repair of activation-induced cytidine deaminase-induced lesions in germinal center (GC) B cells but can also cause genomic instability. GC B cells express low levels of the DNA repair protein apurinic/apyrimidinic (AP) endonuclease (APE)1 and high levels of its homolog APE2. Reduced SHM in APE2-deficient mice suggests that APE2 promotes SHM, but these GC B cells also exhibit reduced proliferation that could impact mutation frequency. In this study, we test the hypothesis that APE2 promotes and APE1 suppresses SHM. We show how APE1/APE2 expression changes in primary murine spleen B cells during activation, impacting both SHM and class-switch recombination (CSR). High levels of both APE1 and APE2 early after activation promote CSR. However, after 2 d, APE1 levels decrease steadily with each cell division, even with repeated stimulation, whereas APE2 levels increase with each stimulation. When GC-level APE1/APE2 expression was engineered by reducing APE1 genetically (apex1+/-) and overexpressing APE2, bona fide activation-induced cytidine deaminase-dependent VDJH4 intron SHM became detectable in primary B cell cultures. The C terminus of APE2 that interacts with proliferating cell nuclear Ag promotes SHM and CSR, although its ATR-Chk1-interacting Zf-GRF domain is not required. However, APE2 does not increase mutations unless APE1 is reduced. Although APE1 promotes CSR, it suppresses SHM, suggesting that downregulation of APE1 in the GC is required for SHM. Genome-wide expression data compare GC and cultured B cells and new models depict how APE1 and APE2 expression and protein interactions change during B cell activation and affect the balance between accurate and error-prone repair during CSR and SHM.
    Mesh-Begriff(e) Animals ; Mice ; B-Lymphocytes/metabolism ; Cell Culture Techniques ; Cytidine Deaminase/genetics ; Cytidine Deaminase/metabolism ; DNA Repair ; Immunoglobulin Class Switching/genetics ; Mutation ; Somatic Hypermutation, Immunoglobulin
    Chemische Substanzen Cytidine Deaminase (EC 3.5.4.5) ; Apex1 protein, mouse (EC 4.2.99.18) ; Apex2 protein, mouse (EC 3.1.-) ; AICDA (activation-induced cytidine deaminase) (EC 3.5.4.-)
    Sprache Englisch
    Erscheinungsdatum 2023-04-19
    Erscheinungsland United States
    Dokumenttyp Journal Article ; Research Support, N.I.H., Extramural
    ZDB-ID 3056-9
    ISSN 1550-6606 ; 0022-1767 ; 1048-3233 ; 1047-7381
    ISSN (online) 1550-6606
    ISSN 0022-1767 ; 1048-3233 ; 1047-7381
    DOI 10.4049/jimmunol.2100946
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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  10. Artikel ; Online: Synthesis of 1,4-Diazacycles by Hydrogen Borrowing.

    Nalikezhathu, Anju / Tam, Adriane / Cherepakhin, Valeriy / Do, Van K / Williams, Travis J

    Organic letters

    2023  Band 25, Heft 10, Seite(n) 1754–1759

    Abstract: We report the syntheses of 1,4-diazacycles by diol-diamine coupling, uniquely made possible with a (pyridyl)phosphine-ligated ruthenium(II) catalyst ( ...

    Abstract We report the syntheses of 1,4-diazacycles by diol-diamine coupling, uniquely made possible with a (pyridyl)phosphine-ligated ruthenium(II) catalyst (
    Sprache Englisch
    Erscheinungsdatum 2023-03-03
    Erscheinungsland United States
    Dokumenttyp Journal Article
    ISSN 1523-7052
    ISSN (online) 1523-7052
    DOI 10.1021/acs.orglett.3c00468
    Datenquelle MEDical Literature Analysis and Retrieval System OnLINE

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