Allergic sensitization continues to increase over childhood into adolescence although the majority of children who were not sensitized at 4 years remain non-sensitized throughout childhood and adolescence. The presence of sensitization at 4 years predicted later sensitization to additional allergens.

A detailed investigation of the polymerisation conditions for poly(2,2′‐(1,4‐phenylene)5,5′‐bibenzimidazole) (para‐PBI) in polyphosphoric acid (PPA) led to the preparation of high molecular weight polymer. The polymer solutions could be used directly to produce phosphoric acid (PA)‐doped PBI membranes by the PPA process. These membranes showed very high PA doping levels, i.e., up to ∼30 moles of PA per mole of PBI repeat unit. The ionic conductivity of the membranes was 0.24 S cm–1 at 160 °C. Fuel cell performance was measured at various operating conditions by changing temperature, pressure and gases and verified the high carbon monoxide (CO) tolerance of fuel cells operating at this temperature.

Background Cluster analyses have enhanced understanding of the heterogeneity of both paediatric and adult wheezing. However while adolescence represents an important transitional phase, the nature of young adult wheeze has yet to be clearly characterised. Objectives To use cluster analysis to define, for the first time, clinically relevant young adult wheeze clusters in a longitudinal birth cohort. Methods K-Means Cluster analysis was undertaken among 309 currently wheezing subjects at 18-years in the Isle of Wight Birth Cohort ( N=1456). Thirteen disease characterising clustering variables at 18-years were used. Resulting clusters were then further characterised by severity indices plus potential risk factors for wheeze development throughout the 1st 18-years of life. Results Six wheeze clusters were identified. Cluster 1 (12.3%) male-early-childhood-onset-atopicwheeze-with-normal-lung function had male predominance, normal spirometry, low BDR (bronchodilator reversibility), intermediate BHR (bronchial hyper-responsiveness), high atopy prevalence, and more admissions. Cluster 2 (24.2%) early-childhood-onset-wheeze-with-intermediate-lung-function had no specific sex association, intermediate spirometry, BDR, BHR, more significant BTS step therapy and admissions. Cluster 3 (9.7%) female-early-childhood-onset-atopic-wheeze-with-impaired-lung-function showed female predominance, high allergic disease comorbidity, more severe BDR and BHR, greatest airflow obstruction, high smoking prevalence, higher symptom severity and admissions. Cluster 4 (19.4%) female-undiagnosed-wheezers had adolescent onset non-atopic wheeze, low BDR and BHR, impaired but non-obstructed spirometry, high symptom frequency and highest smoking prevalence. Cluster 5 (24.6%) female-late-childhood-onset-wheeze-with-normal-lung-function showed no specific atopy association, normal spirometry, low BDR, BHR, and symptom severity. Cluster 6 (9.7%) male-late-childhood-onset-atopic-wheeze-with-impaired-lung-function had high atopy and rhinitis prevalence, elevated BDR and BHR, moderately impaired spirometry, high symptom severity and higher BTS step therapy. Conclusions & Clinical Relevance Young adult wheeze is diverse and can be classified into distinct clusters. More severe clusters merit attention and are associated with childhood onset, atopy, impaired lung function and in some, smoking. Smoking associated undiagnosed-wheezers also merit recognition. Better understanding of young adult wheeze could facilitate better later adult respiratory health.

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