Crystallographic studies of some tetracyaquidimethane complexes.

The solid state structures of charge-transfer complexes of 7,7,8,8-tetracyanoquinodimethane, TCNQ, have been reviewed and classified into three main structural types viz homosoric (pseudosoric), heterosoric, and nonsoric. In an attempt to more fully understand the factors influencing the type of structure adopted in the solid state and to relate the structural features to the electrical conductivities, the crystal structures of five TCNQ complexes have been determined by X-ray analysis:(i) Dimethyldibenzophospholium Bis-7,7,8,8-tetracyanoquinodimethanide, is a semi-conductor and belongs to the pseudosoric class of TCNQ complexes, with the cations and the TCNQ moieties forming segregated stacks. The TCNQ molecules are arranged in a diadic fashion with the diads being held together by an array of short intermolecular contacts to give two-dimensional sheets.(ii) Dimethyldiphenylphosphonium Bis-7,7,8,8-tetracyanoquinodimethanide is a good semi-conductor which adopts a monadic/diadic stacking of the TCNQ moieties into columns. The resulting one-dimensionality of the structure is attributed to the presence of statistically disordered cations. The influence of such cation disorder upon the electrical conductivities has been examined for related phosphonium complexes.(iii) N,N'-Dicyanophenyl-4,4'-bipyridylium Tetrakis-7,7,8,8-tetracyanoquinodimethanide, is found to be a pseudosoric complex with the TCNQ moieties contained within sheets in a tetradic manner. The poor semi-conducting properties are attributed to the presence of the cyanophenyl groupings which facilitate significant interactions between anion and cation stacks.(iv) 1,2-Diethyl-4,4' -bipyridiniumethane Tetrakis-7,7,8,8-tetra-cyanoquinodimethanide is a poor semi-conductor containing tetradic stacks of TCNQ, molecules within which there is poor overlap. Thetetrads are arranged in sheets containing extensive intermolecular electrostatic interactions.(v) 4,4'-Bipyridylethylene 7,7,8,8-tetracyanoquinodimethane, (DPE)-(TCNQ,), is a heterosoric complex and contains stacks of alternating donor (DPE) and acceptor (TCNQ) molecules. The large distances between donor and acceptor molecules within each stack and the geometry of the TCNQ molecule indicate little or no charge-transfer to be present

Microstructure and Fracture Properties of Semi-Hard Cheese: Differentiating the Effects of Primary Proteolysis and Calcium Solubilization

The individual roles of hydrolysis of αS1- and β-caseins, and calcium solubilization on the fracture properties of semi-hard cheeses, such as Maasdam and other eye-type cheeses, remain unclear. In this study, the hydrolysis patterns of casein were selectively altered by adding a chymosin inhibitor to the curd/whey mixture during cheese manufacture, by substituting fermentation-produced bovine chymosin (FPBC) with fermentation-produced camel chymosin (FPCC), or by modulating ripening temperature. Moreover, the level of insoluble calcium during ripening was quantified in all cheeses. Addition of a chymosin inhibitor, substitution of FPBC with FPCC, or ripening of cheeses at a consistent low temperature (8 °C) decreased the hydrolysis of αS1-casein by ~95%, ~45%, or ~30%, respectively, after 90 d of ripening, whereas ~35% of β-casein was hydrolysed in that time for all cheeses, except for those ripened at a lower temperature (~17%). The proportion of insoluble calcium as a percentage of total calcium decreased significantly from ~75% to ~60% between 1 and 90 d. The rigidity or strength of the cheese matrix was found to be higher (as indicated by higher fracture stress) in cheeses with lower levels of proteolysis or higher levels of intact caseins, primarily αS1-casein. However, contrary to the expectation that shortness of cheese texture is associated with αS1-casein hydrolysis, fracture strain was significantly positively correlated with the level of intact β-casein and insoluble calcium content, indicating that the cheeses with low levels of intact β-casein or insoluble calcium content were more likely to be shorter in texture (i.e., lower fracture strain). Overall, this study suggests that the fracture properties of cheese can be modified by selective hydrolysis of caseins, altering the level of insoluble calcium or both. Such approaches could be applied to design cheese with specific properties

Responses of Ammonia-Oxidising Bacterial Communities to Nitrogen, Lime, and Plant Species in Upland Grassland Soil

Agricultural improvement of seminatural grasslands has been shown to result in changes to plant and microbial diversity, with consequences for ecosystem functioning. A microcosm approach was used to elucidate the effects of two key components of agricultural improvement (nitrogen addition and liming) on ammonia-oxidising bacterial (AOB) communities in an upland grassland soil. Plant species characteristic of unimproved and improved pastures (A. capillaris and L. perenne) were planted in microcosms, and lime, nitrogen (NH4NO3), or lime plus nitrogen added. The AOB community was profiled using terminal restriction fragment length polymorphism (TRFLP) of the amoA gene. AOB community structure was largely altered by NH4NO3 addition, rather than liming, although interactions between nitrogen addition and plant species were also evident. Results indicate that nitrogen addition drives shifts in the structure of key microbial communities in upland grassland soils, and that plant species may play a significant role in determining AOB community structure

Immunoglobulin G from bovine milk primes intestinal epithelial cells for increased colonization of bifidobacteria

peer-reviewedAbstract A bovine colostrum fraction (BCF) was recently shown to enhance the adherence of several commensal organisms to intestinal epithelial cells through modulating the epithelial cell surface. In this study, the main components of the BCF were examined to investigate the active component/s responsible for driving the changes in the intestinal cells. The adherence of various bifidobacteria to HT-29 cells was increased when the intestinal cells were pre-incubated with immunoglobulin G (IgG). Modulation of the intestinal cells by IgG was concentration dependent with 16 mg/mL IgG resulting in a 43-fold increase in the adhesion of Bifidobacterium longum NCIMB 8809 to HT-29 cells. Periodate treatment of colostral IgG prior to performing the colonization studies resulted in a reduction in the adhesion of the strain to the intestinal cells demonstrating that the glycans of IgG may be important in modulating the intestinal cells for enhanced commensal adhesion. IgG isolated from mature milk also resulted in significant increases in adhesion of the Bifidobacterium strains tested albeit at reduced levels (3.9-fold). The impact of IgG on the HT-29 cells was also visualised via scanning electron microscopy. This study builds a strong case for the inclusion of IgG ingredients sourced from cow’s milk in functional foods aimed at increasing numbers of health promoting bacteria in the human gut

Seasonal and management influences on bacterial community structure in an upland grassland soil

Floristically diverse Nardo–Galion upland grasslands are common in Ireland and the UK and are valuable in agricultural, environmental and ecological terms. Under improvement (inputs of lime, fertiliser and re-seeding), they convert to mesotrophic grassland containing very few plant species. The effects of upland grassland improvement and seasonality on soil microbial communities were investigated at an upland site. Samples were taken at five times in one year in order to observe seasonal trends, and bacterial community structure was monitored using automated ribosomal intergenic spacer analysis (ARISA), a DNA-fingerprinting approach. Differences in soil chemistry and bacterial community structure between unimproved and improved grassland soils were noted. Season was also found to cause mild fluctuations in bacterial community structure, with soil samples from colder months (October and December) more correlated with change in ribotype profiles than samples from warmer months. However, for the majority of seasons clear differences in bacterial community structures from unimproved and improved soils could be seen, indicating seasonal influences did not obscure effects associated with improvement

Influence of particle size on the physicochemical properties and stickiness of dairy powders

peer-reviewedThe compositional and physicochemical properties of different whey permeate (WPP), demineralised whey (DWP) and skim milk powder (SMP) size fractions were investigated. Bulk composition of WPP and DWP was significantly (P < 0.05) influenced by powder particle size; smaller particles had higher protein and lower lactose contents. Microscopic observations showed that WPP and DWP contained both larger lactose crystals and smaller amorphous particles. Bulk composition of SMP did not vary with particle size. Surface composition of the smallest SMP fraction (<75 μm) showed significantly lower protein (−9%) and higher fat (+5%) coverage compared with non-fractionated powders. For all powders, smaller particles were more susceptible to sticking. Hygroscopicity of SMP was not affected by particle size; hygroscopicity of semi-crystalline powders was inversely related to particle size. This study provides insights into differences between size fractions of dairy powders, which can potentially impact the sticking/caking behaviour of fine particles during processing.ACCEPTEDpeer-reviewe

Rationale for and protocol of a multi-national population-based bacteremia surveillance collaborative

<p>Abstract</p> <p>Background</p> <p>Bloodstream infections are frequent causes of human illness and cause major morbidity and death. In order to best define the epidemiology of these infections and to track changes in occurrence, adverse outcome, and resistance rates over time, population based methodologies are optimal. However, few population-based surveillance systems exist worldwide, and because of differences in methodology inter-regional comparisons are limited. In this report we describe the rationale and propose first practical steps for developing an international collaborative approach to the epidemiologic study and surveillance for bacteremia.</p> <p>Findings</p> <p>The founding collaborative participants represent six regions in four countries in three continents with a combined annual surveillance population of more than 8 million residents.</p> <p>Conclusion</p> <p>Future studies from this collaborative should lead to a better understanding of the epidemiology of bloodstream infections.</p

Sodium bicarbonate to improve physical function in patients over 60 years with advanced chronic kidney disease:the BiCARB RCT

Acknowledgements: We would like to acknowledge the support received from the NHS Scotland Support for Science scheme and the NIHR Renal and Ageing Comprehensive Research Networks; the work of all the investigators, research nurses and study teams at the different sites and the Tayside CTU staff; and, most importantly, all those with kidney disease who participated in the trial. In addition, we acknowledge the support and advice that we received from the independent TSC members (Professor David Stott, Professor Patrick Mark, Professor Tahir Masud and Mr Alex Stephen) and the independent DMC members (Professor Alex McConnachie, Professor David Wheeler, Dr Nicosha de Souza and Dr Andrew Clegg). Professor Marion McMurdo and Dr Simon Ogston were co-applicants on the original proposal, but demitted from the project on retirement and were not involved in the creation of this report. Trial registration: Current Controlled Trials ISRCTN09486651 and EudraCT 2011-005271-16. The systematic review is registered as PROSPERO CRD42018112908. Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 24, No. 27. See the NIHR Journals Library website for further project information.Peer reviewedPublisher PD

Idiopathic pulmonary fibrosis and p-ANCA positivity predating manifestations of systemic vasculitis

The occurrence of perinuclear anti-neutrophilic cytoplasmic antibodies (p-ANCA) in pulmonary fibrosis has been reported in a number of small studies, however, the appearance of p-ANCA in already established idiopathic pulmonary fibrosis (IPF), predating the manifestations of vasculitis has not been widely appreciated. We report 2 cases with radiographic evidence of established IPF where p-ANCA was negative at the time of diagnosis and became positive during the course of the disease, for a variable period of time, prior to the subsequent development of systemic vasculitis. Our cases suggest a possible rationale for serial p-ANCA measurements in patients with pulmonary fibrosis even in the absence of features suggestive of vasculitis. Furthermore, the required frequency of ANCA measurement in the absence of clinical features of vasculitis is unknown. Larger studies with repetitive p-ANCA measurement in tandem with ongoing clinical assessment for vasculitis are required to assess the prevalence of ANCA and to confirm our observation

Differences between Chronological and Brain Age Are Related to Education and Self-Reported Physical Activity

This study investigated the relationship between education and physical activity and the difference between a physiological prediction of age and chronological age (CA). Cortical and subcortical gray matter regional volumes were calculated from 331 healthy adults (range: 19-79 years). Multivariate analyses identified a covariance pattern of brain volumes best predicting CA (R(2) = 47%). Individual expression of this brain pattern served as a physiologic measure of brain age (BA). The difference between CA and BA was predicted by education and self-report measures of physical activity. Education and the daily number of flights of stairs climbed (FOSC) were the only 2 significant predictors of decreased BA. Effect sizes demonstrated that BA decreased by 0.95 years for each year of education and by 0.58 years for 1 additional FOSC daily. Effects of education and FOSC on regional brain volume were largely driven by temporal and subcortical volumes. These results demonstrate that higher levels of education and daily FOSC are related to larger brain volume than predicted by CA which supports the utility of regional gray matter volume as a biomarker of healthy brain aging