a b s t r a c tA mixture of acetic and 2-methylpropanoic (isobutyric) acids representing non-branched and branched acids, respectively, was catalytically converted to a mixture of ketones in a set of statistically designed experiments (DOE). The selectivity toward the cross-ketonization product was analyzed depending on (a) temperature within 300-450 • C range, (b) molar fraction of each acid in the mixture, from 10% to 90%, and (c) liquid hourly space velocity (LHSV) within 2-12 h −1 , and compared against the selectivity toward two symmetrical ketones. Six metal oxide catalysts were tested and ranked on their ability to yield the cross-product as opposed to the self-condensation product. The catalysts were based on either the anatase form of titania or monoclinic form of zirconia and treated with either KOH or K 2 HPO 4 . The titania catalyst treated by KOH outperformed all other catalysts by providing the cross-selectivity above the statistically expected binomial distribution. The criterion for having a high cross-selectivity in the decarboxylative ketonization is formulated mathematically as the separation of roles of two acids, one being a more active enolic component, and the other being the preferred carbonyl component. According to the suggested criterion, the less branched acetic acid reacts as both the preferred carbonyl and enolic component with untreated catalysts. Therefore, untreated catalysts promote selective formation of the symmetrical ketone, acetone, thereby decreasing the selectivity to the cross-ketone. After alkaline treatment, both the anatase form of titania and monoclinic form of zirconia increase the isobutyric acid participation as the carbonyl component. Acetic acid remains as the preferred enolic component with all treated catalysts, thus increasing the selectivity toward the cross-product in the ketonization of a mixture of carboxylic acids. The condition for achieving a high cross-selectivity by polarizing roles of the two reactants can be extended to other types of cross-condensations.

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This study retrospectively evaluated the safety, impact on growth, and clinical outcomes of gastrojejunostomy tubes (GJTs) converted from surgically placed gastrostomy tubes (GTs) in 44 developmentally disabled children (median age: 28 months). The total duration of GJT follow-up was 31,378 device-days (median: 643 device-days). Three major complications (aspiration pneumonia) were identified in 3 patients (6.8%), 63 minor complications in 31 patients (70.5%), and 202 tube maintenance issues (TMIs) in 41 patients (93.2%). A significantly increased average change in weight-for-age z-scores was observed at each 6-month interval that continued past 25 months. Patients above the median rate of TMIs had marginally significant lower z-scores across the study period (P = 0.06), compared with those below the median rate. GJTs were removed in 6 patients (13.6%) because of adequate oral intake at last follow-up. Conversion from GTs to GJTs was a viable option to achieve sustained growth in developmentally disabled children. Frequency of TMIs may negatively impact their growth.

Purpose: To retrospectively investigate risk factors for chest port (port) infections in a large cohort of patients with various medical histories. Materials: Between January 2013 and December 2015, 1039 patients (M/F: 511/528, median age: 59.0 years) underwent port placement. Port placement was generally avoided in patients with severe neutropenia (ANCo500/mL). Medical histories of the patients included cancer (n ¼ 995) and nononcologic chronic medical disease (CMD) (n ¼ 44), such as sickle cell disease. Medical records and imaging studies were reviewed to identify port infections (local and systemic). Patients' demographics, laboratory data at the time of port placement, and port characteristics were recorded. Risk factors for infection were elucidated using univariate and multivariate logistic regressions. Results: A total of 327,071 catheter days (median per patient: 246 catheter days) were observed. A total of 85 infections (8.2%, 0.026/100 catheter days), including 39 local, 34 systemic, and 12 both local and systemic were identified. The median time to infection was 97 days (range: 9-796 days). In univariate analyses, patients with CMD, o60 years of age, steroids, leukocytosis (WBC411,000/mL), double lumen port, and history of a prior port were risk factors of infection. No cancer types were found to be a risk factor. In multivariate logistic regression, patients with CMD (OR 2.84, 95% CI 1.15-7.02), leukocytosis (OR 1.89, 95% CI 1.10-3.24), and a double lumen port (OR 2.81, 95% CI 1.14-5.60) had a significantly elevated risk of infection, while patients with a history of a prior port were at a marginally elevated risk (p ¼ .07). Notably, patients with CMD had a significantly higher number of patients with prescribed steroids (p ¼ .02), leukocytosis (p ¼ .02), and history of prior port (po.001). Conclusions: Careful patient selection for port placement is necessary in patients with CMD, leukocytosis, or a history of prior port. A single lumen port would be advised in these patient populations.