The Effects of Small Molecules on the Thermal Degradations of Some Vinyl Polymers

In the introductory chapter, the development of research into thermal degradation is traced from study of homopolymers, through copolymers and binary polymer blends, to the present study of polymer/small molecule blends. Following a chapter describing the experimental techniques employed, Chapter Three consists of results, abstracted into tabular form, of a survey of the effects of various small molecules on the thermal degradation of a range of polymers. On the basis of this survey, three blends were chosen, for reasons given in Chapters Four, Five, and Six, to be studied in detail. Zinc bromide was found to exert a massive effect on the thermal degradation of poly(methyl methacrylate) by combining with pendant ester groups to form a co-ordination complex, which subsequently allows cyclisation reactions at low temperature, with liberation of methyl bromide. A complete reaction mechanism for blend degradation is proposed. The effect of zinc bromide on poly(vinyl acetate) degradation, again thought to proceed through complex formation, is of a catalytic nature, resulting in liberation, of acetic acid at temperatures much lower than those required for release of acetic acid from poly(vinyl acetate) alone. Chapter Six deals with the effect, on poly(methyl methacrylate) degradation, of zinc oxide, a widely used commercial additive. In this case, the effect is less marked, with zinc oxide promoting some decomposition of methyl methacrylate units at high temperature, accompanied by some reduction to zinc in the process. In overall conclusion, it can be seen that, whereas some small molecules do not affect polymer degradation, a large number exert a significant influence. The type of effect depends on particular polymer/additive selection, but on the basis of Chapters Four and Five, one possible generalisation is that the likelihood of low temperature degradation is increased if polymer-additive complex formation is possible

The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients

Risk Prediction for Acute Kidney Injury in Acute Medical Admissions in the UK

Background Acute Kidney Injury (AKI) is associated with adverse outcomes; identifying patients who are at risk of developing AKI in hospital may lead to targeted prevention. This approach is advocated in national guidelines but is not well studied in acutely unwell medical patients. We therefore aimed to undertake a UK-wide study in acute medical units (AMUs) with the following aims: to define the proportion of acutely unwell medical patients who develop hospital-acquired AKI (hAKI); to determine risk factors associated with the development of hAKI; and to assess the feasibility of using these risk factors to develop an AKI risk prediction score. Methods In September 2016, a prospective multicentre cohort study across 72 UK AMUs was undertaken. Data were collected from all patients who presented over a 24-hour period. Chronic dialysis, community-acquired AKI (cAKI) and those with fewer than two creatinine measurements were subsequently excluded. The primary outcome was the development of h-AKI. Results 2,446 individuals were admitted to the AMUs of the 72 participating centres. 384 patients (16%) sustained AKI of whom 287 (75%) were cAKI and 97 (25%) were hAKI. After exclusions, 1,235 participants remained in whom chronic kidney disease (OR 3.08, 95% CI 1.96-4.83), diuretic prescription (OR 2.33, 95% CI 1.5-3.65), a lower haemoglobin concentration and an elevated serum bilirubin were independently associated with development of hAKI. Multivariable model discrimination was moderate (c-statistic 0.75), and this did not support the development of a robust clinical risk prediction score. Mortality was higher in those with hAKI (adjusted OR 5.22; 95% CI 2.23-12.20). Conclusion AKI in AMUs is common and associated with worse outcomes, with the majority of cases community acquired. The smaller proportion of hAKI cases, only moderate discrimination of prognostic risk factor modelling and the resource implications of widespread application of an AKI clinical risk score across all AMU admissions suggests that this approach is not currently justified. More targeted risk assessment or automated methods of calculating individual risk may be more appropriate alternatives

Correction for Rodriguez-Medina et al., "Draft Genome Sequences of 16 Halophilic Prokaryotes Isolated from Diverse Environments".

Volume 9, no. 8, e01540-19, 2020, https://doi.org/10.1128/MRA.01540-19. Page 2: Lines 3 and 4 of Acknowledgments should read as follows. "This work was supported by a Howard Hughes Medical Institute Professor grant awarded to Mark Goldman (grant number 52008137). We thank Jonathan Eisen, Katherine Dahlhausen, Mark Goldman, Ashley Vater, and David Coil for help with course design and planning"

Draft Genome Sequences of 16 Halophilic Prokaryotes Isolated from Diverse Environments.

Halophile-specific enzymes have wide-ranging industrial and commercial applications. Despite their importance, there is a paucity of available halophile whole-genome sequences. Here, we report the draft genome sequences of 16 diverse salt-tolerant strains of bacteria and archaea isolated from a variety of high-salt environments

Positioning in political marketing: How Semiotic Analysis Can Support Traditional Survey Approaches

The 2010 British election particularly focused on the party leaders' images - a departure in fifty years of British elections. The principal contribution of the article is to illustrate how a combined approach to assessing leadership positioning using both the traditional survey and semiotic analysis can provide insights into what image attribute dimensions end up in the minds of members of the public (actual positioning) and on what image attribute dimensions party marketers are trying to position themselves (intended positioning). Using data from the 2010 British general elections, our findings indicate that the combined methodological approach would be particularly useful for brands that need repositioning, those whose image attribute positions change dramatically over time, and those who wish to target previously unresponsive target audience segments