Experiments on the Preparation of Aminohydroxynaphthoic Acids

Some suggested methods for the preparation of aminohydroxynaphthoic acids have been investigated. The main part of the research was devoted to the preparation of those having the -NH2 group in the 2-position, and the particular one desired was the 2-amino-5-hydroxy-7-naphthoic acid. The scheme, outlined on pages 13 and 14, shows that the -OH group was to be introduced by sulphonation and subsequent alkali fusion of 2:7-aminonaphthoic acid. Consequently the first consideration was the preparation of 2:7-aminonaphthoic acid. The formation of 2:7-aminonaphthonitrile by replacement of -SO3H by -CN by the dry distillation of 2:7-aminonaphthalene sulphonic acid with KCN and K4Fe(CN)6 gave very poor yields, insufficient for the subsequent series of reactions, while fusion with KCN under pressure eliminated the -SO3H group. The diazotisation of 2:7-aminonaphthol was successfully accomplished by the usual Greiss reaction in the presence of a large excess of HCl; also after the method of Hodgson & Walker, and that of Schoutissen, but attempts to form the 2:7-cyanonaphthol by the Sandmeyer reaction and various modifications of same failed due to the preference of the diazo compound to couple with itself. The diazotisation of 2:7-diaminonaphthalene was accomplished using a modification of the method of Schoutissen, but attempts to form the 2:7-aminonaphthonitrile failed. 2:7-Aminonaphthoic acid was synthesised from 2:7-aminonaphthalene sulphonic acid by the series of reactions outlined on page 82 and described on pages 120-136, and successfully sulphonated but the yield of sulphonic acid was poor. The same result was obtained with chlorosulphuric acid. Sulphonation of the acetyl derivative gave excellent yields, but isomers were present and various attempts to separate them were unsuccessful, while conversion to the aminohydroxynaphthoic acids by alkali fusion yielded oxidation products. Estimation of the alpha-SO3H groups in the sulphonation mixture gave 60%. It would appear, judging from results on page 125, that about 40% of the sulphonic mixture contains the -SO3H group in the 6-position. The preparation of 1:2:7- and 1:2:6-aminohydroxynaphthoic acids was accomplished by method 1. They were obtained as the hydrochlorides since the free bases oxidise very rapidly in the air. The action of nitrous acid on 2:7- and 2:6-hydroxy-naphthoic acids gave highly coloured products containing no nitrogen. A table of properties is given on page 189

Acoustically controlled enhancement of molecular sensing to assess oxidative stress in cells

We demonstrate a microfluidic platform for the controlled aggregation of colloidal silver nanoparticles using surface acoustic waves (SAWs), enabling surface enhanced Raman scattering (SERS) analysis of a cell based model for oxidative damage. We show that by varying the frequency and the power of the acoustic energy, it is possible to modulate the aggregation of the colloid within the sample and hence to optimise the SERS analysis

The Angular Distribution of Photoneutrons From O16

The relative importance of competing reaction channels in the photo-excitation of the giant resonance in O16 has been studied by measurement of the angular distribution of the emitted photo-neutrons through the corresponding energy range using a multi-angle neutron time of flight spectrometer installed at the Kelvin Laboratory of the University of Glasgow. Design factors for the spectrometer are discussed with regard to optimisation of energy resolution and counting rates under the constraints of the source, and the obtainable accuracy of normalisation between neutron detectors at different angles has been measured, A reliable method of calibration of the neutron energy scale at each angle is described and corrections to the neutron spectra for absorption by materials in the flight path have been made. The energy dependent efficiency of the neutron detectors is calculated in an appendix by a Monte Carlo technique using a new measurement of the scintillation response curve for recoil protons. Angular distributions of photoneutrons from the D2 (gamma,n)p reaction with 26.9 MeV bremsstrahlung have been measured and are found to agree with previously published results and theoretical predictions to within the expected accuracy. This is taken as confirmation of good angular normalisation in the system. Measurements by the author of the angular distributions of photo-neutrons from 26.9 MeV bremsstrahlung on O16 are presented and absolute cross sections have been obtained with respect to that known for deuterium. Photoproton data from other authors is analysed in a similar way for comparison with the photoneutron results. In the E1 approximation, the relative intensity of s/d wave admixture is found to follow the resonance structure for both protons and neutrons and the corresponding phase difference is found to vary about the value expected from optical model predictions. The E2 cross section has been extracted from the data and is found to rest mainly in two broad states centred at about 23 MeV and 24.7 MeV, while a Barker-Mann analysis shows the isospin impurity in the O16 giant resonance to be small and to be mainly associated with the regions of E2 strength. The pure 1p1h dipole approximation fails to describe these features and the observed splitting of the giant resonance in O16 but the presence of more complicated excitations is shown to be more consistent with experiment

Renal fibrosis in feline chronic kidney disease: known mediators and mechanisms of injury

Chronic kidney disease (CKD) is a common medical condition of ageing cats. In most cases the underlying aetiology is unknown, but the most frequently reported pathological diagnosis is renal tubulointerstitial fibrosis. Renal fibrosis, characterised by extensive accumulation of extra-cellular matrix within the interstitium, is thought to be the final common pathway for all kidney diseases and is the pathological lesion best correlated with function in both humans and cats. As a convergent pathway, renal fibrosis provides an ideal target for the treatment of CKD and knowledge of the underlying fibrotic process is essential for the future development of novel therapies. There are many mediators and mechanisms of renal fibrosis reported in the literature, of which only a few have been investigated in the cat. This article reviews the process of renal fibrosis and discusses the most commonly cited mediators and mechanisms of progressive renal injury, with particular focus on the potential significance to feline CKD

A Supplementary Description of Cypridina mariae and Rediagnosis of the Genus Cylindroleberis (Ostracoda: Myodocopa: Cylindroleberididae)

The ostracod family Cylindroleberididae is based on the genus Cylindroleberis Brady, 1868, and has a complicated nomenclatural history. The type species of Cylindroleberis is Cypridina mariae Baird, 1850. Baird described only the carapace, which had been considered lost. Thus, there was no reference point for the concept C. mariae or the genus Cylindroleberis. Baird's material has now been found in the Natural History Museum, London, U.K., and is illustrated here. To clarify the taxonomic status of C. mariae and Cylindroleberis, specimens were obtained from near the type locality, and a supplementary description is presented. This includes description of appendages, particularly the first antenna and mandible, which contain important diagnostic characters. This supplementary description provides important information about C. mariae, allowing a revision of the genus Cylindroleberis, and establishing a framework for future biological research on this ostracod group

Evolution of three Pyrenophora cereal pathogens: recent divergence, speciation and evolution of non-coding DNA

Three of the most important fungal pathogens of cereals are Pyrenophora tritici-repentis, the cause of tan spot on wheat, and Pyrenophora teres f. teres and Pyrenophora teres f. maculata, the cause of spot form and net form of net blotch on barley, respectively. Orthologous intergenic regions were used to examine the genetic relationships and divergence times between these pathogens. Mean divergence times were calculated at 519 kya (±30) between P. teres f. teres and P. teres f. maculata, while P. tritici-repentis diverged from both Pyrenophora teres forms 8.04 Mya (±138 ky). Individual intergenic regions showed a consistent pattern of co-divergence of the P. teres forms from P. tritici-repentis, with the pattern supported by phylogenetic analysis of conserved genes. Differences in calculated divergence times between individual intergenic regions suggested that they are not entirely under neutral selection, a phenomenon shared with higher Eukaryotes. P. tritici-repentis regions varied in divergence time approximately 5–12 Mya from the P. teres lineage, compared to the separation of wheat and barley some 12 Mya, while the P. teres f. teres and P. teres f. maculata intergenic region divergences correspond to the middle Pleistocene. The data suggest there is no correlation between the divergence of these pathogens the domestication of wheat and barley, and show P. teres f. teres and P. teres f. maculata are closely related but autonomous. The results are discussed in the context of speciation and the evolution of intergenic regions

The association of bacteriuria with survival and disease progression in cats with azotemic chronic kidney disease

Background Cats with chronic kidney disease (CKD) have an increased prevalence of positive urine cultures (PUC). Limited information is available regarding the prognosis of cats with CKD and concurrent PUC. Objective To determine the association of PUC with survival time and disease progression in cats with CKD. Animals Medical records of 509 cats diagnosed with azotemic CKD between 1997 and 2018. Methods Cats were classified as having “no‐PUC” or “PUC.” The PUC cats were further classified as having 1 or multiple PUC, and also were classified based on the presence or absence of clinical signs of urinary tract infection (UTI). Progression of CKD was defined as a plasma creatinine concentration increase of ≥25% within 365 days of CKD diagnosis; PUC also must have occurred within this time frame. Survival time and frequency of CKD progression were compared between groups. Results No significant difference in survival time was found between cats with no‐PUC and cats with any number of PUC (P = .91), or between cats with no‐PUC, 1 PUC or multiple PUC (P = .37). Also, no significant difference was found in the frequency of CKD progression between PUC and no‐PUC cats (P = .5), or among no‐PUC, 1 PUC and multiple PUC cats (P = .22). When assessing cats with clinical signs of lower UTI, no significant difference was found in the frequency of CKD progression between cats with true UTI, subclinical bacteriuria or no‐PUC (P = .8). Conclusions and Clinical Importance When treated with antibiotics, PUC in cats with CKD do not affect disease progression or survival time

Perceptions of Social Mobility: Development of a New Psychosocial Indicator Associated with Adolescent Risk Behaviors

Social class gradients have been explored in adults and children, but not extensively during adolescence. The first objective of this study was to examine the association between adolescent risk behaviors and a new indicator of adolescent relative social position, adolescent “perceived social mobility.” Second, it investigated potential underlying demographic, socioeconomic, and psychosocial determinants of this indicator. Data were taken from the 2004 urban adolescent module of Oportunidades, a cross-sectional study of Mexican adolescents living in poverty. Perceived social mobility was calculated for each subject by taking the difference between their rankings on two 10-rung ladder scales that measured (1) projected future social status and (2) current subjective social status within Mexican society. Adolescents with higher perceived social mobility were significantly less likely to report alcohol consumption, drinking with repercussions, compensated sex, police detainment, physical fighting, consumption of junk food or soda, or watching ≥4 h of television during the last viewing. They were significantly more likely to report exercising during the past week and using a condom during last sexual intercourse. These associations remained significant with the inclusion of covariates, including parental education and household expenditures. Multiple logistic regression analyses show higher perceived social mobility to be associated with staying in school longer and having higher perceived control. The present study provides evidence for the usefulness of perceived social mobility as an indicator for understanding the social gradient in health during adolescence. This research suggests the possibility of implementing policies and interventions that provide adolescents with real reasons to be hopeful about their trajectories