The synthesis and reactions of some fluorinated polycyclic polyenes

Perfluorocyclohexa-l,3-diene gave the expected 1,4-adducts with cyclohexene, cyclopentene,1,2H-octafluorocyclohexene, 1H,2H-hexafluorocyclopenteneand lH,2H-tetrafIuorocyclobutene; reaction with 1H,2H-tetrafluorocyclobutene also yielded two 2,2-difluorovinyldecafluorobicyclo[4,2,0]oct-2-enes and the dimer 3,3,4,4,7,7,8,8-octafluorotricyclo[3,3,0,0(^2,4)]octane. Dehydrofluorinatlon of the adducts from 1H,2H-octafluorocyclohexene and 1H,2H-hexafluorocyclopentene gave the trienes, perfluorotricyclo[5,2,2,0(^2,7)]dodeca-2,6,9-triene and perfluorotricyclo[5,2,2,0(^2.6)]undeca-2,5,8-triene respectively. Perfluorotricyclo[5,2,2,0(^2,6)]undeca-2,5,8-triene reacted as a diene in Diels-Alder reactions with ethylene, propyne and but-2-yne. The 1,4-adducts with alkynes could be pyrolysed selectively to either polyfluorobenzobicyclo-[2,2,2]octa-2,5-dienes or 2,3-disubstituted hexafluoronaphthalenes. Irradiation of perfluorotricyclo[6,2,2,0(^2,7)]dodeca-2,6,9-triene and perfluorotricyclo[5,2,2,0 (^2,6)]undeca-2,5,8-triene in the vapour phase with UV radiation resulted in their isomerisation to perfluorotetracyclo[6,2,2,0(^2,7)0(^5,7)]-dodeca-2,9-dienes and perfluorotricyclo[5,2,2,0(^2,6)]undeca-2,3,8-triene respectively. Arguments presented support the latter isomerisation being a photochemical 1,5-sigmatropic migration of a fluorine atom. Vacuum pyrolysis of perfluorotricyclo[5,2,2,0(^2.6)]undeca-2,5,8-triene provides perfluoroindene in good yield. Irradiation of 2H-heptafluorocyclohexa-1,3-diene in the vapour phase with UV radiation yielded 2H-heptafluorobicyclo[2,2,0]hex-2-ene, the isomerisation proceeding in the reverse direction on pyrolysis; the photoisomer was of the same order of dienophilicity as perfluorobicyclo[2,2,0]-hex-2-ene towards furan. Perfluoroindene reacted readily with the nucleophiles sodium borohydride, sodium methoxide and lithium methyl replacing initially one of the vinylic fluorines in the five-membered ring. Its olefinic character was evident from the formation of a mixture of hydrazones on reaction with hydrazine hydrate and the isolation of l,l,3,4,5,6,7-heptafluoroindan-2-one from its reaction with oleum; intermediate unstable compounds formed in the latter transformation suggest that the initial stage in the reaction is the formation of the β sultone of perfluoroindene

Principles of factory cost keeping

The book is offered to those interested along cost accounting lines, with the hope that it may help to a clearer understanding of the true aims of this important branch of accounting science

Racial and economic factors in attitudes to immigration

In this paper we distinguish between three channels that determine attitudes to further immigration: labour market concerns, welfare concerns, and racial or cultural concerns. Our analysis is based on the British Social Attitudes Survey. A unique feature of the survey is that it includes questions on attitudes towards immigration from different origin countries, with populations differing in ethnic similarity to the resident population. It also contains sets of questions relating directly to the labour market, benefit expenditure and welfare concerns, and racial and cultural prejudice. Based on this unique data source, we specify and estimate a multiple factor model that allows comparison of the relative magnitude of association of attitudes to further immigration with the three channels, as well as comparison in responses across potential immigrant groups of different origin. Our results suggest that, overall, welfare concerns play a more important role in determination of attitudes to further immigration than labour market concerns, with their relative magnitude differing across potential emigration regions and characteristics of the respondent. In addition, we find strong evidence that racial or cultural prejudice is an important component to attitudes towards immigration; however, this is restricted to immigration from countries with ethnically different populations

Role of gut microbiota-generated short chain fatty acids in metabolic and cardiovascular health

Purpose of this Review: This review assesses the latest evidence linking short-chain fatty acids (SCFA) with host metabolic health and cardiovascular disease (CVD) risk and presents the latest evidence on possible biological mechanisms. Recent Findings: SCFA have a range of effects locally in the gut and at both splanchnic and peripheral tissues which together appear to induce improved metabolic regulation and have direct and indirect effects on markers of CVD risk. Summary: SCFA produced primarily from the microbial fermentation of dietary fibre appear to be key mediators of the beneficial effects elicited by the gut microbiome. Not only does dietary fibre fermentation regulate microbial activity in the gut, SCFA also directly modulate host health through a range of tissue-specific mechanisms related to gut barrier function, glucose homeostasis, immunomodulation, appetite regulation and obesity. With the increasing burden of obesity worldwide, the role for gut microbiota-generated SCFA in protecting against the effects of energy dense diets offers an intriguing new avenue for regulating metabolic health and CVD risk

A Study on Housing for the Home Improvement Project

Like most other cities in the nation, Albuquerque is suffering from lack of planning. It\u27s growth is huge and hapazard. Deterioration and conjestion reveal itself throughout the city. To help fight this deterioration, Albuquerque has asked for federal funds. Unfortunately the appropriation received was not adequate enough to renew all of Albuquerque\u27s deteriorating areas and a decision has been made to inject the funding into the central business district, Martinez Town, South Broadway and the Berelas Area. However, this is only a small portion of Albuquerque\u27s depressed areas. Deterioration has spread through out the Southwest Valley. There is considerable evidence of it in Alemeda and Corrales as well, fortunately these areas are not being completely neglected. For the past three years, an organization called The home improvement project has been responding to the problems of economically depressed areas throughout the entire city

Influential Article Review - Evaluation of the Quality of Health Services: Comparative Analysis of the Groups of Patients

This paper examines healthcare. We present insights from a highly influential paper. Here are the highlights from this paper: The purpose of this study is to examine the effects of healthcare service quality (HEALTHQUAL) measurement items. First, the proposed measurement items for HEALTHQUAL were tested using data collected from a hospital in South Korea with more than 500 beds. The data set included 365 patients and 232 public respondents. ANOVA and t-tests were used to perform a comparative analysis of HEALTHQUAL measurement items among three patient treatment groups (inpatients, outpatients, and family members of patients in the emergency room) and between the patient and general public groups. The results indicated significant differences among measurement items of HEALTHQUAL depending on the type of patient treatment, while there were no significant differences among measurement items of HEALTHQUAL between patients and the public. For our overseas readers, we then present the insights from this paper in Spanish, French, Portuguese, and German

Magnetic resonance imaging and magnetic resonance arthrography of the shoulder: dependence on the level of training of the performing radiologist for diagnostic accuracy

Purpose: Discrepancies were identified between magnetic resonance (MR) imaging and clinical findings in patients who had MR imaging examinations evaluated by community-based general radiologists. The purpose of this study was to evaluate the diagnostic performance of MR imaging examinations of the shoulder with regard to the training level of the performing radiologist. Methods: A review of patient charts identified 238 patients (male/female, 175/63; mean age, 40.4years) in whom 250 arthroscopies were performed and who underwent MR imaging or direct MR arthrography in either a community-based or hospital-based institution prior to surgery. All MR imaging and surgical reports were reviewed and the diagnostic performance for the detection of labral, rotator cuff, biceps, and Hill-Sachs lesions was determined. Kappa and Student's t test analyses were performed in a subset of cases in which initial community-based MR images were re-evaluated by hospital-based musculoskeletal radiologists, to determine the interobserver agreement and any differences in image interpretation. Results: The diagnostic performance of community-based general radiologists was lower than that of hospital-based sub-specialized musculoskeletal radiologists. A sub-analysis of re-evaluated cases showed that musculoskeletal radiologists performed better. κ values were 0.208, 0.396, 0.376, and 0.788 for labral, rotator cuff, biceps, and Hill-Sachs lesions (t test statistics: p = <0.001, 0.004, 0.019, and 0.235). Conclusions: Our results indicate that the diagnostic performance of MR imaging and MR arthrography of the shoulder depends on the training level of the performing radiologist, with sub-specialized musculoskeletal radiologists having a better diagnostic performance than general radiologist

Enhanced Post-Ischemic Neurogenesis in Aging Rats

Hippocampal neurogenesis persists in adult mammals, but its rate declines dramatically with age. Evidence indicates that experimentally-reduced levels of neurogenesis (e.g., by irradiation) in young rats has profound influence on cognition as determined by learning and memory tests. In the present study we asked whether in middle-aged, 10- to 13-months-old rats, cell production can be restored toward the level present in young rats. To manipulate neurogenesis we induced bilateral carotid occlusion with hypotension. This procedure is known to increase neurogenesis in young rats, presumably in a compensatory manner, but until now, has never been tested in aging rats. Cell production was measured at 10, 35, and 90 days after ischemia. The results indicate that neuronal proliferation and differentiation can be transiently restored in middle-aged rats. Furthermore, the effects are more pronounced in the dorsal as opposed to ventral hippocampus thus restoring the dorso-ventral gradient seen in younger rats. Our results support previous findings showing that some of the essential features of the age-dependent decline in neurogenesis are reversible. Thus, it may be possible to manipulate neurogenesis and improve learning and memory in old age

An experiment with computer practice testing

The problem of this investigation was concerned with the relationship between computer-assisted practice testing and the achievement of freshmen students in introductory sociology in a community college. The purpose of the study was to examine the potential effect of an interactive computer-practice testing program upon the achievement of introductory sociology students in a community college