Teaching Old Polymers New Tricks: Improved Synthesis and Anomalous Crystallinity for a Lost Semi-Fluorinated Polyaryl Ether via Interfacial Polymerization of Hexafluoroacetone Hydrate and Diphenyl Ether

A practical and direct electrophilic polymerization of hexafluoroacetone hydrate with diphenyl ether toward the preparation of semi-fluorinated polyaryl ethers (PAE) is reported. Electrophilic aromatic substitution (EAS) polymerization under interfacial conditions with phase transfer catalyst (Aliquat 336) proceeds in trifluoromethanesulfonic anhydride by generation of trifluoromethanesulfonic acid and the protonated hexafluoroacetone (HFA) in situ affording 1,1,1,3,3,3-hexafluoroisopropylidene (6F) PAE with high regioselectivity (4,4'-DPE) and high molecular weight (≈60 kDa). Although first reported in a 1966 US Patent by DuPont using harsh conditions, improved synthetic methods or modern characterization has not been disclosed until now. Despite the presence of the 6F group, known to impart disordered morphology, this simple semi-fluorinated PAE exhibits anomalous crystallinity with polymorphic melting points (T_m ) ranging from 230-309 °C, high solubility in common organic solvents, a glass transition (T_g ) of 163 °C, and thermo-oxidative stability above 500 °C. Tough optically clear films prepared from solution give transmittance higher than 90% throughout the visible region. Synthesis, mechanistic aspects, and characterization including surface and dielectric properties are discussed.

Key lessons from the COVID-19 public health response in Australia

Australia avoided the worst effects of the COVID-19 pandemic, but still experienced many negative impacts. Reflecting on lessons from Australia's public health response, an Australian expert panel composed of relevant discipline experts identified the following key lessons: 1) movement restrictions were effective, but their implementation requires careful consideration of adverse impacts, 2) disease modelling was valuable, but its limitations should be acknowledged, 3) the absence of timely national data requires re-assessment of national surveillance structures, 4) the utility of advanced pathogen genomics and novel vaccine technology was clearly demonstrated, 5) decision-making that is evidence informed and consultative is essential to maintain trust, 6) major system weaknesses in the residential aged-care sector require fixing, 7) adequate infection prevention and control frameworks are critically important, 8) the interests and needs of young people should not be compromised, 9) epidemics should be recognised as a 'standing threat', 10) regional and global solidarity is important. It should be acknowledged that we were unable to capture all relevant nuances and context specific differences. However, the intent of this review of Australia's public health response is to critically reflect on key lessons learnt and to encourage constructive national discussion in countries across the Western Pacific Region.

Aging alters signaling properties in the mouse spinal dorsal horn

A well-recognized relationship exists between aging and increased susceptibility to chronic pain conditions, underpinning the view that pain signaling pathways differ in aged individuals. Yet despite the higher prevalence of altered pain states among the elderly, the majority of preclinical work studying mechanisms of aberrant sensory processing are conducted in juvenile or young adult animals. This mismatch is especially true for electrophysiological studies where patch clamp recordings from aged tissue are generally viewed as particularly challenging. In this study, we have undertaken an electrophysiological characterization of spinal dorsal horn neurons in young adult (3–4 months) and aged (28–32 months) mice. We show that patch clamp data can be routinely acquired in spinal cord slices prepared from aged animals and that the excitability properties of aged dorsal horn neurons differ from recordings in tissue prepared from young animals. Specifically, aged dorsal horn neurons more readily exhibit repetitive action potential discharge, indicative of a more excitable phenotype. This observation was accompanied by a decrease in the amplitude and charge of spontaneous excitatory synaptic input to dorsal horn neurons and an increase in the contribution of GABAergic signaling to spontaneous inhibitory synaptic input in aged recordings. While the functional significance of these altered circuit properties remains to be determined, future work should seek to assess whether such features may render the aged dorsal horn more susceptible to aberrant injury or disease-induced signaling and contribute to increased pain in the elderly.

Perfluorocyclohexenyl (PFCH) aromatic ether polymers from perfluorocyclohexene and polycyclic aromatic bisphenols

Semi-fluorinated Perfluorocycloalkenyl (PFCA) aromatic polymers prepared from polycyclic aromatic hydrocarbon (PAH) bisphenols and contain reactive fluoroalkene linkages.

High fractional exhaled nitric oxide and sputum eosinophils are associated with an increased risk of future virus-induced exacerbations: A prospective cohort study

BACKGROUND

The major trigger of asthma exacerbations is infection with a respiratory virus, most commonly rhinovirus. Type 2 inflammation is known to be associated with an increased risk of exacerbations in general. Whether type 2 inflammation at baseline increases the risk of future virus-induced exacerbations is unknown.

OBJECTIVE

To assess whether type 2 inflammation is associated with an increased risk of virus-induced exacerbations of asthma.

METHODS

Stable asthmatics had spirometry, skin prick test, measurement of FeNO and sputum induced for differential cell counts. Patients were followed up for 18 months, during which they were assessed at the research unit when they had symptoms of an exacerbation. Nasal swabs collected at these assessments underwent viral detection by PCR.

RESULTS

A total of 81 asthma patients were recruited, of which 22 (27%) experienced an exacerbation during the follow-up period. Of these, 15 (68%) had a respiratory virus detected at exacerbation. Sputum eosinophils >1% at baseline increased the risk of having a subsequent virus-induced exacerbation (HR 7.6 95% CI: 1.6-35.2, P=.010) as did having FeNO >25 ppb (HR 3.4 95% CI: 1.1-10.4, P=.033).

CONCLUSION AND CLINICAL RELEVANCE

Established type 2 inflammation during stable disease is a risk factor for virus-induced exacerbations in a real-life setting. Measures of type 2 inflammation, such as sputum eosinophils and FeNO, could be included in the risk assessment of patients with asthma in future studies.

Challenging hierarchy in healthcare teams - ways to flatten gradients to improve teamwork and patient care

In healthcare, mistakes that are potentially harmful or fatal to patients are often the result of poor communication between members of a team. This is particularly important in high-risk areas such as operating theatres or during any intervention, and the ability to challenge colleagues who are in authority when something does not seem right or is clearly wrong, is crucial. Colleagues in oral and maxillofacial surgery recognised the importance of this as early as 2004, and it is now well known that failure or reluctance to challenge others who might be wrong can severely compromise a patient's safety. The Royal College of Surgeons of Edinburgh runs popular regular courses (Non-technical Skills for Surgeons, NOTSS) that teach how to ensure safety through good communication and teamwork. In this paper we introduce the concept of hierarchical challenge, and discuss models and approaches to address situations when problems arise within a team.

Effectiveness of an Educational Intervention on Reducing Misconceptions Among Ethnic Minorities With Complicated Mild to Severe Traumatic Brain Injury

OBJECTIVE

To evaluate the effectiveness of an educational intervention designed to reduce traumatic brain injury (TBI)-related misconceptions among blacks and Latinos with complicated mild to severe TBI.

DESIGN

Randomized controlled trial with masked 1-month follow-up.

SETTING

Community.

PARTICIPANTS

Persons (N=52) with complicated mild to severe TBI (mean best day 1 Glasgow Coma Scale score, 11.27±3.89) were randomly recruited from 141 eligible participants (mean age, 37.71±13.88y; age range, 19-66y; mean months postinjury, 24.69±11.50); 25 participants (48.1%) of participants were black and 27 (51.9%) were Hispanic/Latino. Of the Hispanic/Latino participants, 18 (66.7%) were non-U.S. born and 12 (44.4%) spoke Spanish as their primary language. Twenty-seven individuals were randomized to the educational intervention group and 25 were randomized to the wait-list control group.

INTERVENTIONS

Single-session educational intervention with written materials provided in English or Spanish.

MAIN OUTCOME MEASURES

Forty-item Common Misconceptions about Traumatic Brain Injury Questionnaire administered at baseline and 1-month follow-up.

RESULTS

After controlling for ethnic and language differences, a significant between-group main effect (P=.010) and a significant time-group interaction for the Common Misconceptions about Traumatic Brain Injury Questionnaire were noted (Wilks Λ=.89; F_1,46=6.00; P=.02). The intervention group showed a decrease in TBI misconception percentages, whereas the wait-list control group maintained similar percentages. At 1-month follow-up, the wait-list control group reported more misconceptions than did the intervention group (P=.019).

CONCLUSIONS

An educational intervention developed to address the recovery process, common symptoms, and ways to handle the symptoms provides promise as a tool to decrease TBI misconceptions among persons from ethnically and educationally diverse backgrounds. The effects of therapist characteristics and the client-therapist relation on outcomes should be further explored.

Semi-Fluorinated Epoxy Thermoplastics Containing the α-Methylstilbene Linkage

The reaction of the mesogenic epoxy monomer, p-bis(2,3-epoxypropoxy)-α-methylstilbene, with bis(hydroxyphenyl)- iso-propylidene and bis(hydroxyphenyl)hexafluoro- iso-propylidene affords new semifluorinated poly(hydroxy aryl ether) thermoplastics with controlled properties dependent upon fluorine incorporation. Step-growth polymerization in a DMAc solution (33 wt%) gave linear polymers with molecular weights ranging from 29 000–60 000 Mw and polydispersities ( Mw/Mn) from 1.7–2.1 (gel permeation chromatography). The polymers can be solution or melt processed, exhibit Tg’s ranging from 78 to 105 °C (dynamic scanning calorimetry) and maintain thermal stability above 390 °C (thermogravimetric analysis). The polymerization, characterization, and potential mesophase formation as a function of polymer dimensions and semifluorination is discussed.

Consensus guidelines for the investigation and management of encephalitis in adults and children in Australia and New Zealand

Encephalitis is a complex neurological syndrome caused by inflammation of the brain parenchyma. The management of encephalitis is challenging because: the differential diagnosis of encephalopathy is broad; there is often rapid disease progression; it often requires intensive supportive management; and there are many aetiologic agents for which there is no definitive treatment. Patients with possible meningoencephalitis are often encountered in the emergency care environment where clinicians must consider differential diagnoses, perform appropriate investigations and initiate empiric antimicrobials. For patients who require admission to hospital and in whom encephalitis is likely, a staged approach to investigation and management is preferred with the potential involvement of multiple medical specialties. Key considerations in the investigation and management of patients with encephalitis addressed in this guideline include: Which first-line investigations should be performed?; Which aetiologies should be considered possible based on clinical features, risk factors and radiological features?; What tests should be arranged in order to diagnose the common causes of encephalitis?; When to consider empiric antimicrobials and immune modulatory therapies?; and What is the role of brain biopsy?

Symptom Burden and Functional Gains in a Cancer Rehabilitation Unit

BACKGROUND/AIMS

To determine if there is a relationship between patient symptoms and functional improvement on inpatient rehabilitation.

METHODS

Retrospective review of medical records at an American tertiary referral-based cancer center of all patients admitted to an inpatient rehabilitation unit between 3/1/2013-5/20/2013. Main outcome measures included the Edmonton Symptom and Assessment Scale (ESAS) and Functional Independence Measure (FIM).

FINDINGS

The medical records for 71 unique cancer rehabilitation inpatients were analyzed. Statistical analysis of total admission ESAS on total FIM change found no significant relationships. The symptom burden of the patients was mild. Patients demonstrated statistically significant improvements in function and symptoms during inpatient rehabilitation. The mean change in total FIM and total ESAS were an increase of 19.20 and decrease of 7.41 respectively. Statistically significant changes occurred in fatigue, sleep, pain, and anxiety.

CONCLUSION

Both symptom and functional scores improved significantly during inpatient rehabilitation. However, no significant relationships were found between symptoms at admission and improvement in FIM.

Social living mitigates the costs of a chronic illness in a cooperative carnivore

Infection risk is assumed to increase with social group size, and thus be a cost of group living. We assess infection risk and costs with respect to group size using data from an epidemic of sarcoptic mange (Sarcoptes scabiei) among grey wolves (Canis lupus). We demonstrate that group size does not predict infection risk and that individual costs of infection, in terms of reduced survival, can be entirely offset by having sufficient numbers of pack-mates. Infected individuals experience increased mortality hazards with increasing proportions of infected pack-mates, but healthy individuals remain unaffected. The social support of group hunting and territory defence are two possible mechanisms mediating infection costs. This is likely a common phenomenon among other social species and chronic infections, but difficult to detect in systems where infection status cannot be measured continuously over time.

Utilization of a Meldrum's acid towards functionalized fluoropolymers possessing dual reactivity for thermal crosslinking and post-polymerization modification

New thermally cross-linkable and/or post-functionalizable perfluorocyclobutyl (PFCB) polymers containing Meldrum's acid moieties have been successfully prepared via the thermal cyclopolymerization of a new Meldrum's acid functionalized aromatic trifluorovinyl ether (TFVE) monomer.

Distinct miRNA expression in dorsal striatal subregions is associated with risk for addiction in rats

Recently, we published data using an animal model that allowed us to characterize animals into two groups, addiction vulnerable and addiction resilient, where we identified that addiction/relapse vulnerability was associated with deficits in synaptic plasticity-associated gene expression in the dorsal striatum (DS). Notable was the strong reduction in expression for activity-regulated cytoskeleton-associated protein (Arc) considered a master regulator of synaptic plasticity. In the present study, we confirmed that Arc messenger RNA was significantly decreased in the DS, but importantly, we identified that this reduction was restricted to the dorsomedial (DMS) and not dorsolateral striatum (DLS). There is recent evidence of microRNA (miRNA)-associated posttranscriptional suppression of Arc and animal models of addiction have identified a key role for miRNA in the regulation of addiction-relevant genes. In further support of this link, we identified several differentially expressed miRNA with the potential to influence addiction-relevant plasticity genes, including Arc. A key study recently reported that miR-212 expression is protective against compulsive cocaine-seeking. Supporting this hypothesis, we found that miR-212 expression was significantly reduced in the DMS but not DLS of addiction-vulnerable animals. Together, our data provide strong evidence that miRNA promote ongoing plasticity deficits in the DS of addiction-vulnerable animals.

Association between the summer season and body fatness and aerobic fitness among Hispanic children

BACKGROUND

Few studies have investigated changes in adiposity and fitness during the academic year (AY) and summer season (SS) in minority children. This study aimed to assess if adiposity indicators and fitness change during the school AY and SS in Hispanic children.

METHODS

One hundred nineteen low-income Hispanic children (9.2 ± 0.8) participated in the study. Demographic, body weight and height, percent body fat (% BF), and aerobic endurance were assessed at 3 time points: measurement 1 (M1), beginning of AY; M2, end of AY; and M3, end of SS. Using weight and height, body mass index (BMI) was calculated and normalized (BMI z-scores). Mixed effects between-within-subjects analysis of variance (ANOVA) design was used to examine changes in selected variables.

RESULTS

A significant decrease of BMI z-scores in overweight children (p = .024) was observed during the AY only, but not during the SS. Percent BF increased significantly over the AY and SS (p < .001), particularly in girls. Aerobic endurance showed a significant increase over the AY (p < .001), but it did not change over the SS (p = .552).

CONCLUSIONS

Results indicated that the SS might place Hispanic children at increased risk for additional adiposity and lower fitness.

Mathematical modeling of postmenopausal osteoporosis and its treatment by the anti-catabolic drug denosumab

Denosumab, a fully human monoclonal antibody, has been approved for the treatment of postmenopausal osteoporosis. The therapeutic effect of denosumab rests on its ability to inhibit osteoclast differentiation. Here, we present a computational approach on the basis of coupling a pharmacokinetics model of denosumab with a pharmacodynamics model for quantifying the effect of denosumab on bone remodeling. The pharmacodynamics model comprises an integrated systems biology-continuum micromechanics approach, including a bone cell population model, considering the governing biochemical factors of bone remodeling (including the action of denosumab), and a multiscale micromechanics-based bone mechanics model, for implementing the mechanobiology of bone remodeling in our model. Numerical studies of postmenopausal osteoporosis show that denosumab suppresses osteoclast differentiation, thus strongly curtailing bone resorption. Simulation results also suggest that denosumab may trigger a short-term bone volume gain, which is, however, followed by constant or decreasing bone volume. This evolution is accompanied by a dramatic decrease of the bone turnover rate by more than one order of magnitude. The latter proposes dominant occurrence of secondary mineralization (which is not anymore impeded through cellular activity), leading to higher mineral concentration per bone volume. This explains the overall higher bone mineral density observed in denosumab-related clinical studies.

Frequency and reasons for return to the primary acute care service among patients with lymphoma undergoing inpatient rehabilitation

OBJECTIVE

To assess the frequency and risk factors for return to the primary acute care service among patients with lymphoma undergoing inpatient rehabilitation.

DESIGN

Retrospective study.

SETTING

Tertiary referral-based cancer center.

PATIENTS

All patients with a history of lymphoma admitted to an inpatient rehabilitation between October 1, 2003, and January 30, 2013.

MAIN OUTCOME MEASURES

Items analyzed from patient records included return to the primary acute care service with demographic information, lymphoma characteristics, medications, hospital admission characteristics, and laboratory values.

RESULTS

A total of 143 unique patient admissions were analyzed, and 54 of these 143 lymphoma inpatient rehabilitation admissions (38%) returned to the primary acute care service. However, 16 of 54 (30%) returned because they needed additional chemotherapy. Excluding patients who returned to the primary acute care service for chemotherapy, statistically significant or approaching statistically significant factors (P < .10) associated with return to the primary acute care service included a creatinine level ≥ 1.3 mg/dL (P = .0002), male gender (P = .001), history of hematopoietic stem cell transplantation (P = .0355), and presence of an intravenous antifungal agent (P = .0717). Of the patients transferred back to the primary acute care service, 13 of 38 (34%) were discharged directly home, 10 of 38 (26%) died in the hospital, 7 of 38 (18%) were transferred to a subacute rehabilitation facility, and 4 of 38 (11%) were transferred to inpatient rehabilitation.

CONCLUSIONS

When excluding patients who returned for chemotherapy, patients with lymphoma who were male, had undergone hematopoietic stem cell transplantation, and had a creatinine level ≥ 1.3 mg/dL demonstrated increased risk for return to the primary acute care service.

Summer and follow-up interventions to affect adiposity with mothers and daughters

BACKGROUND

The development of effective obesity interventions to reduce adiposity indicators in Latina girls is a public health priority because of their increased risk for becoming overweight. Research indicates that the summer season may be a critical time to intervene because summer exacerbates children's risk for excessive weight gain and increased body fat development.

PURPOSE

The purpose of this study was twofold: (1) to determine if summer and follow-up interventions reduce adiposity in Latina girls; (2) to assess if such interventions reduce adiposity in Latina girls after controlling for their mothers' adiposity measures.

DESIGN

This study had a non-experimental (one-group pre- and multiple post-intervention assessment) design. Following a 4-week healthy-lifestyle summer program, each mother-daughter pair participated in 12 weekly follow-up sessions.

SETTING/PARTICIPANTS

The sample consisted of 61 pairs of Latina girls and their mothers (N=122). Daughters' average age was 10.9 years (± 1.6 years) and mothers' average age was 38.0 years (± 1.6 years). All daughters and 92% of the mothers were categorized as overweight/obese.

MAIN OUTCOME MEASURES

Percent body fat (%BF), abdominal fat, and height and weight measurements to calculate BMI were conducted at pre-intervention (M1 [baseline]) and three post-intervention time points (M2 [Month 2]; M3 [Month 3]; and M4 [Month 6]). Paired sample t-tests were used to assess the differences in adiposity among the daughters from M1 to M4. Repeated-measures ANCOVA tests were used to control for mother's adiposity.

RESULTS

Reductions of %BF (p<0.001); abdominal fat (p<0.05); and BMI (p<0.001) at M2 were found for the summer intervention, but no effects were found at M4. Maternal %BF, abdominal fat, and BMI did not have an impact on the daughters' adiposity indicators.

CONCLUSIONS

Results from this study revealed that a summer intervention appears to be effective in reducing adiposity in Latina girls, but the follow-up sessions did not result in sustaining continued reductions. Maternal measures did not influence their daughters' adiposity measures.

High Performance and Multipurpose Triarylamine-Enchained Semifluorinated Polymers

Transparent, film-forming fluorinated arylene vinylene ether (FAVE) polymers with enchained triarylamine (TAA) moieties were prepared and characterized. Control over fluoro-olefin content within the backbone, as a function of base, was confirmed and postpolymerization dehydrofluorination was shown to increase fluoroolefin content from 5 to 31 mol %. Thermal cross-linking was found to occur approximately 100 °C lower than in traditional FAVE polymers (ca. 160 °C). Electrochemical analysis demonstrated the enchained TAA retained its established electrochemical character. The latent reactivity of the TAA was explored via electrophilic aromatic substitution and formylation reactions toward precise functionalization for specific electro-optic applications and others.

An exploration of transactional states and cessation-related social variables within adolescent smokers

BACKGROUND

Given the high rate of adolescent smoking, cessation remains a vital public health priority. This study explored archival data using a structured phenomenological framework known as Reversal Theory (RT). In order to better understand aspects of adolescent tobacco use we compared the transactional, psychological states described by RT to the factor structure of adolescents' self-reported social environment influencing tobacco use.

METHODS

In a two step analysis of questions about self-reported tobacco use cognitions, attitudes, and behaviors from youth enrolled during the 2003-2004 period in a Texas, state-wide, mandated tobacco cessation program (N=1807), four factors and 11 items were identified as significantly related to the influence of social context and adolescents' tobacco use. These first step results guided the items to be selected for further analysis. In step two the variables were subjected to a factor analysis using principal components extraction and varimax rotation. The resulting factor structure was compared and interpreted within the context of descriptions of RT transactional states.

RESULTS

The analysis indicated that four factors were closely aligned to descriptions of the Reversal Theory transactional states and could be reinterpreted from within the framework of RT. The first factor included feelings of self-efficacy for quitting (autic mastery). The second and third transactional factors diverged between one factor to quit, and an opposing transactional factor to continue to smoke. Both of these transactional states are variants of the autocentric state where one wants to experience feelings of gain with the help of others. The fourth factor could be interpreted as 'confidence' or 'optimism'.

CONCLUSIONS

This intra-individual conflict revealed by the opposition of factors two and three clarifies a paradoxical issue where an adolescent wants to quit smoking with social support in one setting yet in another social environment chooses to smoke to gain or retain peer acceptance. These data illustrate that adolescent' self-identified quit skills and social support structures are important to the quitting process. This exploratory investigation has important implications for addressing RT state reversals in youth cessation programming activities.

Return to primary service among bone marrow transplant rehabilitation inpatients: an index for predicting outcomes

OBJECTIVE

To assess rehabilitation inpatient risk of return to primary (RTP) service in patients with bone marrow transplant (BMT).

DESIGN

Retrospective review.

SETTING

Inpatient rehabilitation unit within a tertiary referral-based cancer center.

PARTICIPANTS

All patients with BMT (131) who were admitted a total of 147 times to inpatient rehabilitation between January 1, 2002, and April 30, 2010.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

We analyzed RTP service and demographic information, cancer characteristics, medications, hospital admission characteristics, and laboratory values.

RESULTS

A total of 61 (41%) of 147 of BMT admissions were transferred from the inpatient rehabilitation unit back to the primary service. Of those transferred back, 23 (38%) of 61 died after being transferred back to the primary service. Significant or near-significant relationships were found for a platelet count of <43,000 per microliter (P<.01); a creatinine level of >0.9 milligrams/deciliter (P<.01); the presence of an antiviral agent (P=.0501); the presence of an antibacterial agent (P=.0519); the presence of an antifungal agent (P<.05); and leukemia, lymphoma, or multiple myeloma diagnosis (P<.05). Using 5 of these factors, the RTP-BMT index was formulated to determine the likelihood of return to the primary team.

CONCLUSIONS

Patients with BMT have a high rate of transfer from the inpatient rehabilitation unit back to the primary service. The RTP-BMT index score can be a useful tool to help clinicians predict the likelihood of return to the primary acute care service.

Effects of cross-modal selective attention on the sensory periphery: cochlear sensitivity is altered by selective attention

There is increasing evidence that alterations in the focus of attention result in changes in neural responding at the most peripheral levels of the auditory system. To date, however, those studies have not ruled out differences in task demands or overall arousal in explaining differences in responding across intermodal attentional conditions. The present study sought to compare changes in the response of cochlear outer hair cells, employing distortion product otoacoustic emissions (DPOAEs), under different, balanced conditions of intermodal attention. DPOAEs were measured while the participants counted infrequent, brief exemplars of the DPOAE primary tones (auditory attending), and while counting visual targets, which were instances of Gabor gradient phase shifts (visual attending). Corroborating an earlier study from our laboratory, the results show that DPOAEs recorded in the auditory-ignoring condition were significantly higher in overall amplitude, compared with DPOAEs recorded while participants attended to the eliciting primaries; a finding in apparent contradiction with more central measures of intermodal attention. Also consistent with our previous findings, DPOAE rapid adaptation, believed to be mediated by the medial olivocochlear efferents (MOC), was unaffected by changes in intermodal attention. The present findings indicate that manipulations in the conditions of attention, through the corticofugal pathway, and its last relay to cochlear outer hair cells (OHCs), the MOC, alter cochlear sensitivity to sound. These data also suggest that the MOC influence on OHC sensitivity is composed of two independent processes, one of which is under attentional control.

Characteristics of a widespread community cluster of H275Y oseltamivir-resistant A(H1N1)pdm09 influenza in Australia

Background. Oseltamivir resistance in A(H1N1)pdm09 influenza is rare, particularly in untreated community cases. Sustained community transmission has not previously been reported.

Methods. Influenza specimens from the Asia–Pacific region were collected through sentinel surveillance, hospital, and general practitioner networks. Clinical and epidemiological information was collected on patients infected with oseltamivir-resistant viruses.

Results. Twenty-nine (15%) of 191 A(H1N1)pdm09 viruses collected between May and September 2011 from Hunter New England (HNE), Australia, contained the H275Y neuraminidase substitution responsible for oseltamivir resistance. Only 1 patient had received oseltamivir before specimen collection. The resistant strains were genetically very closely related, suggesting the spread of a single variant. Ninety percent of cases lived within 50 kilometers. Three genetically similar oseltamivir-resistant variants were detected outside of HNE, including 1 strain from Perth, approximately 4000 kilometers away. Computational analysis predicted that neuraminidase substitutions V241I, N369K, and N386S in these viruses may offset the destabilizing effect of the H275Y substitution.

Conclusions This cluster represents the first widespread community transmission of H275Y oseltamivir-resistant A(H1N1)pdm09 influenza. These cases and data on potential permissive mutations suggest that currently circulating A(H1N1)pdm09 viruses retain viral fitness in the presence of the H275Y mutation and that widespread emergence of oseltamivir-resistant strains may now be more likely.

Amido-modified polylactide for potential tissue engineering applications

Poly(ester amide) copolymers based on L-lactide (2) and a new depsipeptide (1) were prepared by ring opening polymerization in the presence of Sn(Oct)2 as the catalyst. Variable monomer feed ratios up to 2.3 mol% 1 afforded copolymers containing ester and amido functional groups in the backbone. Lower glass transition temperatures and reduced crystallization kinetics and crystallinity compared to homo-polylactide (PLA) was achieved with low levels of amido incorporation. A reactivity comparison between enchainment of 2 and 1 was determined using in situ infrared spectroscopy. An increase in shear viscosity was observed with the increase of 1 content as determined by rheology studies. Cellular compatibility of the co-polymers was investigated by seeding D1 mouse stem cells onto films and characterizing cell morphology by optical microscopy. Preliminary results indicate that these novel materials exhibit reduced cell attachment compared to PLA and, pending further exploration, may have potential use in biomedical applications.

FUNCTIONALIZATION OF USED TIRE RUBBER BY HYDROSILYLATION

A new method for the surface modification of used tire rubber (UTR) is being developed. The method involves hydrosilylation of ground UTR particles with trichlorosilane (TCS) under various reaction conditions. The reaction has been carried out with and without solvents and catalysts (Karsted's/Pt catalyst). TCS treated UTR particles are then hydrolyzed to obtain silanol functionalized hydrosilylated rubber powder. Attenuated total reflection–Fourier transform infrared, solid-state 13C NMR spectroscopy, and thermogravimetric analysis are provided as evidence of hydrosilylation onto rubber particles.