Insights into post-polymerisation modification of bio-based unsaturated itaconate and fumarate polyesters via aza-michael addition: Understanding the effects of C=C isomerisation.

Development of renewable bio-based unsaturated polyesters is undergoing a renaissance, typified by the use of itaconate and fumarate monomers. The electron-deficient C=C bond found on the corresponding polyesters allows convenient post-polymerisation modification to give a wide range of polymer properties; this is notably effective for the addition of nucleophilic pendants. However, preservation of unsaturated functionality is blighted by two undesirable side-reactions, branching/crosslinking and C=C isomerisation. Herein, a tentative kinetic study of diethylamine addition to model itaconate and fumarate diesters highlights the significance of undesirable C=C isomerisation. In particular, it shows that reversible isomerisation from itaconate to mesaconate (a poor Michael acceptor) is in direct competition with aza-Michael addition, where the amine Michael donor acts as an isomerisation catalyst. We postulate that undesired formation of mesaconate is responsible for the long reaction times previously reported for itaconate polyester post-polymerisation modification. This study illustrates the pressing need to overcome this issue of C=C isomerisation to enhance post-polymerisation modification of bio-based unsaturated polyesters. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018, 56, 1935-1945.

The influence of status and the social environment on energy stores in a social fish.

This study explores how muscle and liver energy stores are linked with social status and the social environment in Neolamprologus pulcher, a cooperatively breeding fish that lives in colonies comprised of up to 200 distinct social groups. Subordinate muscle energy stores were positively correlated with the number of neighbouring social groups in the colony, but this pattern was not observed in dominant N. pulcher. Furthermore, liver energy stores were smaller in dominants living at the edge of the colony compared with those living in the colony centre, with no differences among subordinates in liver energy stores. Subordinate N. pulcher may build up large energy stores in the muscles to fuel rapid growth after dispersal, which could occur more frequently in high-density environments. Dominant N. pulcher may use the more easily mobilized energy stores in the liver to fuel daily activities, which could be more energetically demanding on the edge of the colony as a result of the increased predation defence needed on the edge. Overall, this study demonstrates that both subordinate and dominant physiology in N. pulcher varies with characteristics of the social environment. Furthermore, dominant and subordinate energy storage strategies appear to differ due to status-dependent variation in daily activities and variation in the need to prepare for future reproductive or dispersal opportunities.

Destined for indecision? A critical analysis of waste management practices in England from 1996 to 2013.

European nations are compelled to reduce reliance on landfill as a destination for household waste, and should, in principle, achieve this goal with due recognition of the aims and principles of the waste hierarchy. Past research has predominantly focused on recycling, whilst interactions between changing waste destinies, causes and drivers of household waste management change, and potential consequences for the goal of the waste hierarchy are less well understood. This study analysed Local Authority Collected Waste (LACW) for England, at national, regional and sub-regional level, in terms of the destination of household waste to landfill, incineration and recycling. Information about waste partnerships, waste management infrastructure and collection systems was collected to help identify and explain changes in waste destinies. Since 1996, the proportion of waste landfilled in England has decreased, in tandem with increases in recycling and incineration. At the regional and sub-regional (Local Authority; LA) level, there have been large variations in the relative proportions of waste landfilled, incinerated and recycled or composted. Annual increases in the proportion of household waste incinerated were typically larger than increases in the proportion recycled. The observed changes took place in the context of legal and financial drivers, and the circumstances of individual LAs (e.g. landfill capacity) also explained the changes seen. Where observed, shifts from landfill towards incineration constitute an approach whereby waste management moves up the waste hierarchy as opposed to an attempt to reach the most preferred option(s); in terms of resource efficiency, this practice is sub-optimal. The requirement to supply incinerators with a feedstock over their lifespan reduces the benefits of developing of recycling and waste reduction, although access to incineration infrastructure permits short-term and marked decreases in the proportion of LACW landfilled. We conclude that there is a need for clearer national strategy and co-ordination to inform and guide policy, practice, planning and investment in infrastructure such that waste management can be better aligned with the principles of the circular economy and resource efficiency. If the ongoing stand-off between national political figures and the waste sector continues, England's waste policy remains destined for indecision.

Pharmacokinetic Modeling of the Glucoregulatory System.

A pharmacokinetic model is proposed to describe the glucoregulatory process. The model describes the dynamics of glucose, amino acids, and fatty acids, as well as both the hormonal actions and dynamics of insulin, glucagon, epinephrine, and glucagon-like peptide-one. The model was developed assuming that the dynamics of each species occurrs in only one compartment. Several forms of the metabolic absorption and elimination rates, along with possibilities for increasing the complexity of each compartmental model are discussed. Once properly identified and validated, the novel model has the potential to be more descriptive than other models describing glucose dynamics in the body.

Diagnosis of recurrent intermittent airway obstruction ("recurrent croup") in children.

Children with a history of recurrent intermittent airway obstruction can present with a constellation of signs and symptoms labeled by their primary care physician as "recurrent croup." Recurrent croup, however, is not a diagnosis and should alert the clinician to the potential for intrinsic or extrinsic laryngotracheal pathology. This study was undertaken to evaluate referral patterns, diagnostic algorithms, and diagnoses for children with a history of recurrent intermittent airway obstruction initially characterized as "recurrent croup." We performed a retrospective analysis of office and operative records of children with a history of recurrent intermittent airway obstruction characterized as "recurrent croup." The setting was a university-based pediatric otolaryngology practice with both urban and suburban referral patterns. The medical records of 53 children (median age, 2 years) with a history of mild to severe recurrent intermittent airway obstruction characterized as "recurrent croup" were evaluated with respect to referral source, duration of signs and symptoms, diagnostic algorithm, and findings. We conclude that recurrent intermittent airway obstruction in children is an underappreciated clinical scenario. Upper aerodigestive tract endoscopy is a key component in a diagnostic evaluation to ascertain the cause. The decision for an endoscopic evaluation is best determined after analysis of the patient's age, past medical history, clinical severity, and suspected diagnosis. By virtue of his or her knowledge of aerodigestive tract anatomy and endoscopy skills, the otolaryngologist can take a proactive role in arriving at an accurate diagnosis in these children.

Developmental science, systems of care, and prevention of emotional and behavioral problems in youth.

Developmental science, a metatheoretical framework for investigating individual development across the lifecourse, is discussed in terms of its application to prevention and treatment of emotional and behavioral problems. The multifaceted, dynamic, and bidirectional contribution of factors, both internal and external to the individual, is thus emphasized. Key aspects of developmental science, systems of care, and prevention are described, and the implications for delivery of mental health services to children and youth are discussed.

Adult herpetic laryngitis with concurrent candidal infection: a case report and literature review.

Rarely, adult herpetic laryngitis without involvement of the oropharynx has been reported. However, to our knowledge, laryngitis caused by herpes simplex virus with coexisting Candida albicans has not been reported. We report what we believe to be the first case of localized herpetic laryngitis superimposed by laryngeal Candida species infection in an immunosuppressed patient. This diagnosis was made on the basis of the findings of a laryngeal mucosal biopsy and ancillary testing using fungal stains and immunohistochemical stains for herpetic antigens. We also review the literature and discuss the clinical and diagnostic presentations, including potential pitfalls in the diagnosis.

Heterogeneity of popular boys: antisocial and prosocial configurations.

This study examined subtypes of popular 4th-6th grade boys (N = 452). Popular-prosocial (model) and popular-antisocial (tough) configurations were identified by means of teacher ratings and compared with peer and self-assessments and social centrality measures. Peers perceived model boys as cool, athletic, leaders, cooperative, studious, not shy, and nonaggressive. Peers perceived tough boys as cool, athletic, and antisocial. Model boys saw themselves as nonaggressive and academically competent. Tough boys saw themselves as popular, aggressive, and physically competent. Tough boys were disproportionately African American, particularly when African Americans were a minority in their classrooms. Model and tough boys were overrepresented at nuclear social centrality levels. These findings suggest that highly aggressive boys can be among the most popular and socially connected children in elementary classrooms.

Development and evaluation of a multimedia resource pack for oral health training of medical and nursing staff.

A resource pack has been devised for training medical and nursing staff and other carers in order that they may recognize oral disease and carry out routine oral care and treat common oral disorders. The custom-designed folding pack contains a videotape, a CD-ROM disc, and an A5-sized spiral-bound booklet, together with wall posters and a list of useful addresses. One hundred of the packs were distributed across Scotland to medical, nursing, and dental staff involved in postgraduate medical and nursing education. The packs were independently evaluated by an external organization through a questionnaire and also by telephone interviews. The pack received very positive responses, and 35% of the respondents reported making changes to their current practice. A long-term measure of success, beyond the scope of this paper, will depend on the measurement of improved quality of oral health care of the patients in those institutions where the pack has been used in training.

Penetration of beta-lactamase inhibitors into the periplasm of gram-negative bacteria.

The effectiveness of a beta-lactamase inhibitor/beta-lactam combination against Gram-negative pathogens depends on many interplaying factors, one of which is the penetration of the inhibitor across the outer membrane. In this work we have measured the relative penetrations of clavulanic acid, sulbactam, tazobactam and BRL 42715 into two strains of Escherichia coli producing TEM-1 beta-lactamase, two strains of Klebsiella pneumoniae producing either TEM-1 or K-1, and two strains of Enterobacter cloacae each producing a Class C beta-lactamase. It was shown that clavulanic acid penetrated the outer membranes of all these strains more readily than the other beta-lactamase inhibitors. For the strains of E. coli and K. pneumoniae clavulanic acid penetrated approximately 6 to 19 times more effectively than tazobactam, 2 to 9 times more effectively than sulbactam and 4 to 25 times more effectively than BRL 42715. The superior penetration of clavulanic acid observed in this study is likely to contribute to the efficacy of clavulanic acid/beta-lactam combinations in combating beta-lactam resistant bacterial pathogens.

Automated mass spectrometry imaging with a matrix-assisted laser desorption ionization time-of-flight instrument.

The automated use of a matrix-assisted laser desorption ionization (MALDI) mass spectrometer (MS) is described for image analysis of samples through implementation of new software for instrument control, data acquisition, and data analysis. The software permits automated acquisition of MS MALDI spectra to form an ordered data array and contains display features to provide images at one or more mass-to-charge ratio values. The technique can be used to scan tissue samples, blotted samples, gels, or other sample surfaces where the image analysis of that sample is required. The program achieves a time of typically 1 s per image point, permitting an analysis made up of large numbers of points with high spatial resolution up to 850 dpi. The features of the software are demonstrated in this paper with samples of printed images, where visible images can be compared to those obtained by mass spectrometry. Quantitative aspects are introduced by analyzing a series of sample spots containing different amounts of several proteins.

Determination of protein-protein interactions by matrix-assisted laser desorption/ionization mass spectrometry.

A number of different procedures have been developed for use with matrix-assisted laser desorption/ionization mass spectrometry (MALDI/MS) for the analysis of non-covalent protein-protein complexes. These include use of specific matrix and laser combinations, accumulation of "first shot" spectra, modification of pH and solvent conditions during sample preparation and use of cross-linking agents to attach the monomers covalently to each other in the complex. The results have shown the techniques to be effective with some but not all complexes, although cross-linking is the most successful. The physical and chemical nature of the complex is critical and therefore a diversity of approaches is recommended for such studies.

Biochemical and Enzyme Kinetic Applications for the Characterization of ßLactamases.

For the last 20 yr thin-layer polyacrylamide isoelectric focusing (IEF) has played a major role in the identification and characterization of ß-lactamases. IEF is able to distinguish enzymes that focus only 0.05 pI apart (1), but the exponential increase rin the numbers of ß-lactamases discovered over the last 10 yr has meant that this method no longer provides sufficient resolution to distinguish the majority of ß-lactamases. Today the pI of a ß-lactamase is still an essential determinant that must be used in combination with a variety of other data. Moreover, the IEF of ß-lactamases is now entering a new era as this technique can be adapted to provide important biochemical information on ß-lactamases other than simply their pI values. These approaches are discussed in Subheading 3.1.

Molecular imaging of biological samples: localization of peptides and proteins using MALDI-TOF MS.

Matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS) has been used to generate ion images of samples in one or more mass-to-charge (m/z) values, providing the capability of mapping specific molecules to two-dimensional coordinates of the original sample. The high sensitivity of the technique (low-femtomole to attomole levels for proteins and peptides) allows the study of organized biochemical processes occurring in, for example, mammalian tissue sections. The mass spectrometer is used to determine the molecular weights of the molecular in the surface layers of the tissue. Molecules desorbed from the sample typically are singly protonated, giving an ion at (M + H)+, where M is the molecular mass. The procedure involves coating the tissue section, or a blotted imprint of the section, with a thin layer of energy-absorbing matrix and then analyzing the sample to produce an ordered array of mass spectra, each containing nominal m/z values typically covering a range of over 50,000 Da. Images can be displayed in individual m/z values as a selected ion image, which would localize individual compounds in the tissue, or as summed ion images. MALDI ion images of tissue sections can be obtained directly from tissue slices following preparative steps, and this is demonstrated for the mapping of insulin contained in an islet in a section of rat pancreas, hormone peptides in a small area of a section of rat pituitary, and a small protein bound to the membrane of human mucosa cells. Alternatively, imprints of the tissue can be analyzed by blotting the tissue sections on specially prepared targets containing an adsorbent material, e.g., C-18 coated resin beads. Peptides and small proteins bind to the C-18 and create a positive imprint of the tissue which can then be imaged by the mass spectrometer. This is demonstrated for the MALDI ion image analysis of regions of rat splenic pancreas and for an area of rat pituitary traversing the anterior, intermediate, and posterior regions where localized peptides were mapped. In a single spectrum from the anterior/intermediate lobe of a rat pituitary print, over 50 ions corresponding to the peptides present in this tissue were observed as well as precursors, isoforms, and metabolic fragments.

Inhibition of metallo-beta-lactamases by a series of mercaptoacetic acid thiol ester derivatives.

A series of mercaptoacetic acid thiol esters have been identified as metallo-beta-lactamase inhibitors. Electrospray mass spectrometry (ESMS) has shown that irreversible inhibition of the Bacillus cereus II metallo-beta-lactamase by SB214751, SB214752, and SB213079 was concomitant with a 90-Da increase in mass of the enzyme. Tryptic digestion of the B. cereus II inhibited with SB214751 illustrated that the peptide fragment, containing the only cysteine of the enzyme, had undergone a mass increment of 90 Da. It was further demonstrated that B. cereus II hydrolyzed this type of compound across the thiol ester bond to yield mercaptoacetic acid. Mercaptoacetic acid is the only molecular fragment common to SB214751, SB214752, and SB213079, and free mercaptoacetic acid does not bind covalently to B. cereus II. Therefore, it is concluded that these compounds inhibit B. cereus II by the mechanism-based delivery of mercaptoacetic acid, forming a disulfide linkage with the active sites cysteine (predicted mass shift = +90 Da) under the aerobic conditions of the assay. The different thiol esters examined had a broad range of potencies against the metallo-beta-lactamases tested. For example SB214751, SB214752, and SB213079 all had 50% inhibitory concentrations of < 10 and > 1,000 microM for the Stenotrophomonas maltophilia L-1 and Bacteroides fragilis CfiA enzymes, respectively. SB216968 was particularly active against the Aeromonas hydrophila CphA metallo-beta-lactamase and was found to be an uncompetitive inhibitor of this enzyme (Ki = 3.9 microM), whereas it exhibited irreversible inhibition of the L-1 enzyme. These observations with this series of compounds have revealed subtle differences between the active sites of different metallo-beta-lactamases. Finally, a novel application for isothermal titration calorimetry for assessing the zinc chelating activity of candidate inhibitors is also presented.

Analysis of hypermutation in immunoglobulin heavy chain passenger transgenes.

Somatic hypermutation of immunoglobulin (Ig) genes plays a critical role in the maturation of the human antibody response. The molecular basis of this important process is, however, unknown. To identify cis-acting sequences that initiate and target hypermutation, we have made three minitransgenes containing different portions of an Ig heavy chain (IgH) locus. Each transgene is a passenger, bearing a nonsense mutation preventing its translation; thus, transgene mutations reflect the endogenous mutational process and are not subject to affinity selection. To study transgenes after their circulation through the compartment associated with hypermutation in vivo, we rescued B cells as hybridomas after hyperimmunizing mice with the hapten 4-hydroxy-3-nitrophenyl acetyl (NP). Hybridoma transgene and endogenous variable regions were amplified by polymerase chain reaction, subcloned, and sequenced. Endogenous anti-NP VDJ regions show the expected, at times extensive degree of base substitution. In mice bearing the smallest construct, which includes 2.4 kb of 5' IgH sequences, a rearranged VDJ region, the 5' matrix attachment region, and the intron enhancer, one of four evaluable hybridomas demonstrates two base substitutions in the V segment of one transgene copy. The two larger constructs include additional 3' IgH sequences (an alpha constant region and the 3' enhancer) and either the original VDJ segment or a substituted T cell receptor beta segment. Ten hybridomas derived from mice bearing these larger constructs demonstrate no evidence of targeted mutation, despite demonstrable transgene transcription in all hybridomas. In our system, mutation of a rearranged VDJ segment and surrounding promoter/enhancer regions is not increased by the juxtaposition of a constant region segment and the IgH 3' enhancer.

Acromial arch shape: assessment with MR imaging.

PURPOSE: To test the hypothesis that acromial shape is comparable on supraspinatus outlet view radiographs and parasagittal magnetic resonance (MR) images. MATERIALS AND METHODS: Supraspinatus outlet view radiographs of a dried scapula were obtained in the neutral position and with various degrees of caudal, cranial, anterior, and posterior angulation. Sagittal MR images of 41 asymptomatic and 39 symptomatic shoulders were reviewed and compared with outlet view radiographs from the 39 symptomatic cases. Acromial shape was assessed with published classification schemes. RESULTS: Minor variations in angulation produced changes in apparent acromial shape and thickness on the radiographs. MR imaging from a lateral to a more medial section changed the shape or thickness grade in 39 of 41 asymptomatic shoulders. There was poor correlation between findings at radiographic and MR assessment of acromial shape in the symptomatic group. CONCLUSION: Apparent acromial shape is sensitive to minor changes in radiographic technique and MR section viewed.