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The asymmetric ring opening of azlactones via dynamic kinetic resolution (DKR) is investigated by contrasting thioureas incorporating 1-arylethyl substituents against their more acidic trifluoromethylated analogs. All the catalysts under study outperform Takemoto's thiourea because of the inclusion of an additional chiral center. However, the difference in yield and selectivity between the fluorinated and non-fluorinated catalysts is minimal. We explain this observation by analysis of calculated transition states. Our findings show that the hydrogen bond (HB) between the NH linked to the 1-arylethyl and the negatively charged oxygen in the benzyloxy ion is the longest in the HB network, whereas the HB between the ammonium group and the same oxygen atom is the shortest. Thus, the substituents and the HB donor ability of this chiral fragment attached to the thiourea are not important in the reaction. [ABSTRACT FROM AUTHOR]

A novel antibacterial system was synthesized by surface modification of silicone rubber films SR with an antimicrobial quaternized 4-vinylpyridine (4VP) and one antibiofouling 2-hydroxyethylmethacrylate (HEMA) by radiation grafting in two steps. The modification was carried out by preirradiation oxidative grafting of HEMA, then direct 4VP radiation grafting and further quaternization. The optimum grafting conditions were obtained and quaternization with alkyl bromide of the pyridine groups of the synthesized systems were realized to study the antimicrobial properties. The modified films were characterized by FTIR spectroscopy, swelling behavior, TGA, SEM and AFM. Studies on antibacterial activity with Gram-positive S. aureus and Gram-negative E. coli were determined; systems with quaternized 4VP presented more than 90% of inhibition for gram positive bacteria, and only one sample (SR- g -4VP) reached 45% of inhibition for gram negative. • New binary grafting with antibacterial properties was synthesized. • New system with biocide and antibiofouling properties was synthesized. • Radiation grafting of quaternized 4VP/HEMA onto silicone rubber was synthesized. • Antibacterial properties in 4VP/HEMA grafted onto SR was obtained. [ABSTRACT FROM AUTHOR]

The consumer has rights at the time of acquiring an item, but does not know it regularly, does not understand or is ill-informed. In that case, a nasty experience of this kind affects the consumer's confidence in the company. Studies on the law that covers a return has been a little tackled issue in marketing. The objective of the work was to determine the level of knowledge and perception of consumers about the returns policies when acquiring a product and the problems in that process. The research was exploratory, descriptive, non-experimental and quantitative with survey technique. Results, there is ignorance of return policies and according to perception they are assessed from regular too bad. Concludes, consumers hold companies responsible for not reporting openly on return policies and consider important the role of companies in the exercise of good practices in market transactions. [ABSTRACT FROM AUTHOR]

Introduction: There are different prediction equations for estimating resting energy expenditure (REE) in children. However, there is not consensus on which it is the most appropriate for use in Mexican pediatric population. Objective: To know the correlation of REE measured by indirect calorimetry with different estimates from prediction equations in a group of school children from Mexico City. Material and method: A cross-sectional study with schoolchildren aged 6 to 12 years (n = 63) was carried out. REE was measured by indirect calorimetry, which was used as reference to assess the accuracy of the prediction equations of Schofield, FAO/WHO, Tverskaya and Harris- Benedict. To assess the agreement between measured TEE and prediction equations, intra-class correlation coefficients (r) were estimated. Results: In the total population the four equations overestimated REE, average differences were from 12.1 a 97.5 kcal. The equations that had the highest agreement with the measured TEE were Schofield and FAO/ WHO (r = 0.74), whereas Tverskaya and Harris-Benedict had the lowest (r = 0.64). Agreement was lower in younger children, especially with the equations of Harris-Benedict (r = 0.33) and Tverskaya (r = 0.47). Conclusions: Although it is required more research on the convenience of using prediction equations of TEE in the Mexican pediatric population, our results showed that the equations of FAO/WHO or Schofield are more appropriate. [ABSTRACT FROM AUTHOR]

Background: With continuously aging societies, an increase in the number of people with cognitive decline is to be expected. Aside from the development of causative treatments, the successful implementation of prevention strategies is of utmost importance to reduce the high societal burden caused by neurodegenerative diseases leading to dementia among which the most common cause is Alzheimer's disease. Objective: The aim of the Luxembourgish "programme dementia prevention (pdp)" is to prevent or at least delay dementia in an at-risk population through personalized multi-domain lifestyle interventions. The current work aims to provide a detailed overview of the methodology and presents initial results regarding the cohort characteristics and the implementation process. Methods: In the frame of the pdp, an extensive neuropsychological evaluation and risk factor assessment are conducted for each participant. Based on the results, individualized multi-domain lifestyle interventions are suggested. Results: A total number of 450 participants (Mean age = 69.5 years; SD = 10.8) have been screened at different recruitment sites throughout the country, among whom 425 participants (94.4%) met the selection criteria. Conclusions: We provide evidence supporting the feasibility of implementing a nationwide dementia prevention program and achieving successful recruitment of the target population by establishing a network of different healthcare providers. [ABSTRACT FROM AUTHOR]

We used our recently proposed acidity–basicity interplay (ABI) model (Chem. Sci., 2018, 9, 4402) and the Jorgensen secondary interactions hypothesis (JSIH) to rationalise the experimentally observed trends in the formation constants of doubly and triply H-bonded systems with –NH…O=C– and –NH…N– interactions. Unlike the JSIH, the ABI interpretation can explain the trends in the complexation of amide/imide homo- and heterodimers as well as ADA–DAD clusters. We found that the strongest H-bonds play a very important role, a condition which offers an alternative to the well established JSIH to modulate the stability of these relevant systems. [ABSTRACT FROM AUTHOR]

Acute bacterial sinusitis is a common disorder affecting children and adults. We performed a study to assess the bacteriology of acute sinusitis in a community hospital in Mexico City. Patients with an acute exacerbation of persistent sinusitis or acute sinusitis were enrolled. Aspiration of sinus secretions was performed and aspirates were sent for culture. All patients received antibiotic treatment for the infection based on microbiologic sensitivity reports. Follow-up consultation included endoscopy and a computed tomography scan of paranasal sinuses to assess response to treatment. A total of 110 patients were enrolled for evaluation. Forty nine percent of patients were women; median age was 31 years. A total of 136 cultures were recovered for analysis. Twenty seven percent of cultures were negative. Isolated organisms were Haemophilus influenzae (26%), Moraxella catarrhalis (15%), Streptococcus pneumoniae (14%), methicillin-sensitive Staphylococcus aureus (7%), enterobacteriaceae (6%), Pseudomonas aeruginosa (2%) and miscellaneous (3%). Twenty eight percent of H. influenzae strains were resistant to ampicillin. Penicillin-sensitive S. pneumoniae (PSSP) and penicillin-intermediate-resistant S. pneumoniae (PISP) accounted for 21% and 79% of the S. pneumoniae strains, respectively. H. influenzae was the most common isolated organism. About 55% of those isolates were found in patients <18 years old and only 25% were resistant to ampicillin. Sinus endoscopy continues to be a useful diagnostic tool in addition to imaging studies in sinus infection and should be pursued by the clinician whenever feasible. [Copyright &y& Elsevier]

Some reasons to undertake are approval, wealth, community sense, personal development, and independence. The objective of the study was to determine the factors that influence the motivation for entrepreneurship among young people of the millennial (Y) and centennial (Z) generation. The research was exploratory descriptive non-experimental, transversal with quantitative approach using the survey technique. Cronbach's Alpha was 0.957, with the level of reliability acceptable. The study population comprised 167,910 students between middle, upper and upper base level. The sample was determined by formula of finite populations with a confidence level of 95% and a margin of error of 6%, resulting in 265 elements, this figure was divided into two parts, 133 corresponding to the millennial generation and 132 of the centennial. Sampling was targeted and fieldwork was conducted during August and September 2019. [ABSTRACT FROM AUTHOR]