2,413 research outputs found

    Chain‐Growth Polymerization of Aryl Grignards Initiated by a Stabilized NHC‐Pd Precatalyst

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    An N‐heterocyclic carbene‐ligated palladium catalyst was discovered to mediate living, chain‐growth polymerizations of both phenylene‐ and thiophene‐based monomers. Polymerization of a fluorene‐based monomer, on the other hand, did not proceed through a living, chain‐growth pathway. Excitingly, block copolymerizations of phenylene and thiophene proceeded via a chain‐growth pathway, regardless of the order of monomer addition. Although some chain termination was observed during these copolymerizations, this pathway could be minimized when the second monomer was added shortly after consumption of the first monomer. These results suggest that the catalyst resting‐state at the end of polymerization is unstable. As a result, modifications to the NHC‐scaffold or the 3‐chloropyridine ligand will be necessary to generate an improved catalyst. A Pd catalyst that can mediate a living, chain‐growth polymerization of π‐conjugated monomers is reported. Using (IPr)Pd(3‐chloropyridine)Cl 2 as a precatalyst, both homopolymers and block copolymers of phenylene‐ and thiophene‐based monomers were prepared. Although a living, chain‐growth mechanism is observed during polymerization, the catalyst resting state is somewhat unstable after the monomer is consumed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92031/1/marc_201200096_sm_suppl.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/92031/2/842_ftp.pd

    Tumor Enucleation for Renal Cell Carcinoma

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    The increased number of small renal masses (SRMs) detected annually has led to a rise in the use of nephron-sparing surgery (NSS).  These techniques aim to preserve the largest amount of healthy renal tissue possible while maintaining the same oncologic outcomes as radical nephrectomy (RN).  Additionally, partial nephrectomy (PN) has been linked to a lower risk of chronic kidney disease, cardiovascular morbidity, and mortality when compared to RN.  There has been continual progress toward resecting less renal parenchyma.  While the predominant surgical method of performing NSS is through traditional PN, simple enucleation (SE) of the tumor has increased in popularity over recent years.  SE is a technique that aims to preserve the maximal amount of renal parenchyma possible by utilizing the renal tumor pseudocapsule to bluntly separate the lesion from its underlying parenchyma, offering the smallest possible margin of excised healthy renal tissue.  Several studies have demonstrated the oncological safety of SE compared with PN in the treatment of SRMs, with lower overall incidence of positive surgical margins.  Additionally, SE has been shown to have similar 5- and 10-year progression-free and cancer-specific survival as PN.  We present a review of the literature and an argument for SE to be a routine consideration in the treatment of all renal tumors amenable to NSS

    Diverse epigenetic mechanisms maintain parental imprints within the embryonic and extraembryonic lineages

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    Genomic imprinting and X chromosome inactivation (XCI) require epigenetic mechanisms to encode allele-specific expression, but how these specific tasks are accomplished at single loci or across chromosomal scales remains incompletely understood. Here, we systematically disrupt essential epigenetic pathways within polymorphic embryos in order to examine canonical and non-canonical genomic imprinting as well as XCI. We find that DNA methylation and Polycomb group repressors are indispensable for autosomal imprinting, albeit at distinct gene sets. Moreover, the extraembryonic ectoderm relies on a broader spectrum of imprinting mechanisms, including non-canonical targeting of maternal endogenous retrovirus (ERV)-driven promoters by the H3K9 methyltransferase G9a. We further identify Polycomb-dependent and -independent gene clusters on the imprinted X chromosome, which appear to reflect distinct domains of Xist-mediated suppression. From our data, we assemble a comprehensive inventory of the epigenetic pathways that maintain parent-specific imprinting in eutherian mammals, including an expanded view of the placental lineage

    Estimating the Effects of Weather, Dry Matter Intake, and Body Weight on Daily Water Intake in Weaned Calves

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    Objective The purpose of this study was to study the effect of weather, dry matter intake, and body weight on the water requirements of weaned calves and estimating the requirements in a model.Study Description Weaned steers (n=48) were selected to study the effects of the weather, body weight, and dry matter intake on water intake in the winter (n=24) and summer (n=24) months. Calves were provided with ad libitum access to feed and water at the SDSU Cow-Calf Education and Research Facility (CCERF) and measured utilizing an automated feed and water system (Insentec, The Hague, Netherlands). Temperature, humidity, precipitation, wind speed, solar radiation, and air pressure were recorded at a Mesonet automated weather station in Brookings, SD (located 2.4 miles from the SDSU CCERF). Effects of climate data, body weight, and daily dry matter intake on daily water intake will be analyzed utilizing a mixed-effects model

    Evaluating Interprofessional Fast Forward Rounds for Transition of Care Education

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    Background: Interprofessional Education is gaining recognition by key pharmacy organizations for its value in healthcare education, producing various models for implementation among healthcare students and professionals. Unfolding cases incorporating transitions of care may improve student skills and attitudes toward interprofessional collaboration. Objectives: This project assessed the efficacy of unfolding cases in improving interprofessional skills and attitudes among pharmacy, nursing, and social work students. The ultimate goal is to integrate this model, if proven effective, into the curricula of multiple health science centers. Methodology: First, pharmacy, nursing, and social work students completed a pre-intervention survey regarding interprofessional skills and attitudes before discussing the first “fast-forward rounds” case in professional silos. After a transitions of care lecture, subjects completed the alternative cases in interprofessional groups in a crossover design. The comparable transitions of care cases included common healthcare topics that were challenging but within the scope of regular practice. “Fast forwards” between transitions of care required students to interpret changes in the case throughout the hospital stay. Following the interprofessional session, group debriefing allowed for feedback on cases, transitions, and differences working with and without other professions. Finally, a post-intervention survey was administered to measure changes in interprofessional attitudes and skills. Analysis: Kruskall-Wallis analysis identified differences among the three majors on the pretest and posttest separately. The Wilcoxon sign rank test assessed changes within each group since normal distribution was not assumed. A Chi-squared test analyzed demographic data. Results: Data analysis of results from the conference revealed a significant improvement in 15 of 25 survey questions in the composite group, while 14, 7, and 4 questions showed significant improvement in the pharmacy, nursing, and social work sub-analyses, respectively. Fewer questions showed significant improvement in the social work group, possibly due to the specific medical details of the cases as well as fewer social work participants relative to pharmacy and nursing. Discussion: Results suggest that this intervention can effectively improve student attitudes toward interprofessional collaboration and understanding of transitions of care. Changes can be made to improve the benefit to social work students and to increase the number of majors participating

    Effectiveness of postoperative radiotherapy after radical cystectomy for locally advanced bladder cancer

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    BACKGROUND: Local-regional failure (LF) for locally advanced bladder cancer (LABC) after radical cystectomy (RC) is common even with chemotherapy and is associated with high morbidity/mortality. Postoperative radiotherapy (PORT) can reduce LF and may enhance overall survival (OS) but has no defined role. We hypothesized that the addition of PORT would improve OS in LABC in a large nationwide oncology database. METHODS: We identified ≄ pT3pN0-3M0 LABC patients in the National Cancer Database diagnosed 2004-2014 who underwent RC ± PORT. OS was calculated using Kaplan-Meier and Cox proportional hazards regression modeling was used to identify predictors of OS. Propensity matching was performed to match RC patients who received PORT vs those who did not. RESULTS: 15,124 RC patients were identified with 512 (3.3%) receiving PORT. Median OS was 20.0 months (95% CI, 18.2-21.8) for PORT vs 20.8 months (95% CI, 20.3-21.3) for no PORT (P = 0.178). In multivariable analysis, PORT was independently associated with improved OS: hazard ratio 0.87 (95% CI, 0.78-0.97); P = 0.008. A one-to-three propensity match yielded 1,858 patients (24.9% receiving PORT and 75.1% without). In the propensity-matched cohort, median OS was 19.8 months (95% CI, 18.0-21.6) for PORT vs 16.9 months (95% CI, 15.6-18.1) for no PORT (P = 0.030). In the propensity-matched cohort of urothelial carcinoma patients (N = 1,460), PORT was associated with improved OS for pT4, pN+, and positive margins (P \u3c 0.01 all). CONCLUSION: In this observational cohort, PORT was associated with improved OS in LABC. While the data should be interpreted cautiously, these results lend support to the use of PORT in selected patients with LABC, regardless of histology. Prospective trials of PORT are warranted

    Physicians’ Knowledge and Beliefs Regarding Athletic Trainers

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    Purpose: The relationship between athletic trainers (ATs) and physicians is a legal obligation and collaboration to improve patient outcomes. The objective of this study was to examine the knowledge of physicians regarding the educational preparation, legal obligations, and scope of practice for ATs and how it relates to previous experiences with ATs. Additionally physicians’ perceptions of Interprofessional Collaboration (IPC) were studied. Methods: 169 physicians medical doctors (MD)=133/169, 78.7%, doctor of osteopathy (DO)=36/169, 21%) completed a 36-question web-based survey, which included a validated IPC scale. Results: Respondents with experience working with an AT scored significantly higher (P \u3c 0.01) on the knowledge assessment, where physicians currently working with an AT scored higher (5.4/8) than those who previously worked with an AT (4.2/8) and those who had never worked with an AT (3.3/8). Additionally, physicians with previous exposure to an AT as an athlete had significantly higher knowledge scores than those without exposure (P \u3c 0.01). Two areas of weakness in IPC from the physician’s perspective included sharing of important information (2.48/4) and importance of work as compared to others on the team (2.38/4). Conclusions: Physicians who have a current working relationship with an AT and those that had access to an AT as an athlete demonstrated significantly higher knowledge about an AT’s academic preparation, legal obligations, and scope of practice. Moreover, physicians currently working with an AT report positive interprofessional collaborations
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