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Background Older adults are recommended to receive influenza vaccination annually, and many use statins. Statins have immunomodulatory properties that might modify influenza vaccine effectiveness (VE) and alter influenza infection risk. Methods Using the test-negative design and linked laboratory and health administrative databases in Ontario, Canada, we estimated VE against laboratory-confirmed influenza among community-dwelling statin users and nonusers aged ≥66 years during the 2010–2011 to 2018–2019 influenza seasons. We also estimated the odds ratio for influenza infection comparing statin users and nonusers by vaccination status. Results Among persons tested for influenza across the 9 seasons, 54 243 had continuous statin exposure before testing and 48 469 were deemed unexposed. The VE against laboratory-confirmed influenza was similar between statin users and nonusers (17% [95% confidence interval, 13%–20%] and 17% [13%–21%] respectively; test for interaction, P = .87). In both vaccinated and unvaccinated persons, statin users had higher odds of laboratory-confirmed influenza than nonusers (odds ratios for vaccinated and unvaccinated persons 1.15 [95% confidence interval, 1.10–1.21] and 1.15 [1.10–1.20], respectively). These findings were consistent by mean daily dose and statin type. VE did not differ between users and nonusers of other cardiovascular drugs, except for β-blockers. We did not observe that vaccinated and unvaccinated users of these drugs had increased odds of influenza, except for unvaccinated β-blocker users. Conclusions Influenza VE did not differ between statin users and nonusers. Statin use was associated with increased odds of laboratory-confirmed influenza in vaccinated and unvaccinated persons, but these associations might be affected by residual confounding.

ImportanceWearing a face mask in school can reduce SARS-CoV-2 transmission but it may also lead to increased hand-to-face contact, which in turn could increase infection risk through self-inoculation.ObjectiveTo evaluate the effect of wearing a face mask on hand-to-face contact by children while at school.Design, Setting, and ParticipantsThis prospective randomized clinical trial randomized students from junior kindergarten to grade 12 at 2 schools in Toronto, Ontario, Canada, during August 2020 in a 1:1 ratio to either a mask or control class during a 2-day school simulation. Classes were video recorded from 4 angles to accurately capture outcomes.InterventionsParticipants in the mask arm were instructed to bring their own mask and wear it at all times. Students assigned to control classes were not required to mask at any time (grade 4 and lower) or in the classroom where physical distancing could be maintained (grade 5 and up).Main Outcomes and MeasuresThe primary outcome was the number of hand-to-face contacts per student per hour on day 2 of the simulation. Secondary outcomes included hand-to-mucosa contacts and hand-to-nonmucosa contacts. A mixed Poisson regression model was used to derive rate ratios (RRs), adjusted for age and sex with a random intercept for class with bootstrapped 95% CIs.ResultsA total of 174 students underwent randomization and 171 students (mask group, 50.6% male; control group, 52.4% male) attended school on day 2. The rate of hand-to-face contacts did not differ significantly between the mask and the control groups (88.2 vs 88.7 events per student per hour; RR, 1.00; 95% CI, 0.78-1.28; P = >.99). When compared with the control group, the rate of hand-to-mucosa contacts was significantly lower in the mask group (RR, 0.12; 95% CI, 0.07-0.21), while the rate of hand-to-nonmucosa contacts was higher (RR, 1.40; 95% CI, 1.08-1.82).Conclusions and RelevanceIn this clinical trial of simulated school attendance, hand-to-face contacts did not differ among students required to wear face masks vs students not required to wear face masks; however, hand-to-mucosa contracts were lower in the face mask group. This suggests that mask wearing is unlikely to increase infection risk through self-inoculation.Trial RegistrationClinicalTrials.gov Identifier: NCT04531254

Optic neuritis (ON) refers to conditions that involve inflammation of the optic nerve. Various autoantibodies have been found, which are associated with central nervous system inflammatory disorders and have provided much information about the immune targets and mechanisms that impact the prognosis, treatment, and recurrence of atypical ON. Therefore, neurologists and ophthalmologists together should work to find out clinical, laboratory, and imaging findings that may provide important clues to the etiology of atypical ON and its management. Various biomarkers have been identified to confirm and distinguish atypical optic neuritis from others. The purpose of this review is to present the current scenario of atypical ON and its clinical management.

Objectives Describe Ontario's school-based human papillomavirus (HPV) vaccination program from the perspective of local public health units (PHUs). Methods In 2018, Vaccine Preventable Diseases (VPD) managers at each of Ontario's 35 PHUs were invited to participate in an online survey regarding the organization and delivery of their HPV vaccination program. Questions were asked on the school-based program, training and support of vaccine providers, communication and promotion, assessing coverage rates and perceptions of the program's strengths and challenges. Descriptive statistics were generated for close-ended items. A thematic content analysis was performed for open-ended items. Results Eighteen PHUs (54%, n = 19/35) responded. All responding PHUs provided the HPV vaccine in publicly funded schools but only 6 reported being permitted to provide HPV vaccine in private schools. Fact sheets, Q&As or other written information locally developed by the PHUs were the main tools used to communicate with parents (n = 17), students (n = 13), school personnel (n = 13) and school board officials (n = 9). The most frequently reported barriers were: limited program resources, negative perceptions held by parents and/or school staff regarding the HPV vaccine, logistical issues (e.g., getting the consents forms returned, collaboration with schools for vaccine delivery) and the fact that HPV vaccination is not mandatory under Ontario legislation. Conclusion Local public health units that implement HPV vaccine programs in schools identified logistical barriers, public perceptions about the HPV vaccine and the voluntary nature of the program as the main barriers.

BACKGROUND AND OBJECTIVES: Maternal immunization with tetanus, diphtheria, and acellular pertussis vaccine (Tdap) is routinely recommended in many countries as a strategy to protect young infants against severe pertussis infection; few studies have assessed whether prenatal exposure to the vaccine is associated with any longer-term adverse health effects in children. We evaluated the long-term safety of exposure to Tdap vaccination during pregnancy. METHODS: Population-based retrospective cohort study conducted in Ontario, Canada using multiple linked province-wide health administrative databases. All live births between April 2012 and March 2017 were included, and children were followed for up to 6 years to ascertain study outcomes. Children exposed to prenatal Tdap were propensity score matched to unexposed children at a 1:5 ratio. Tdap vaccination during pregnancy was ascertained by using vaccine-specific fee codes. Immune-related (infectious diseases, asthma) and nonimmune-related (neoplasm, sensory disorders) outcomes and a nonspecific morbidity outcome (urgent or inpatient health service use) were evaluated from birth to end of follow-up. RESULTS: Of 625 643 live births, 12 045 (1.9%) were exposed to Tdap in utero. There were no significant increased risks of adverse childhood outcomes and prenatal Tdap exposure; however, we observed inverse associations (adjusted incidence rate ratio [95% confidence interval]) with upper respiratory infections (0.94 [0.90–0.99]), gastrointestinal infections (0.85 [0.79–0.91]), and urgent and inpatient health service use (0.93 [0.91–0.96]). CONCLUSIONS: Exposure to Tdap vaccination in pregnancy was not associated with any increased risk of adverse health outcomes in early childhood, supporting the long-term safety of Tdap administration in pregnancy.

Health Care Workers (HCWs) are the backbone of Ontario’s COVID-19 pandemic response and are a key vaccination priority group. About 80% of Ontario HCWs intend to receive COVID-19 vaccine.1 Challenges include the logistics of delivering the vaccine to this mobile and diverse group and improving vaccine confidence in the remaining 20%. These challenges can be overcome by allaying safety concerns and highlighting personal benefits; tailoring messages to factors associated with lower intention (e.g. age, gender, ethnicity and work setting); employing trusted leaders to set the tone and peers to build social norms; and leveraging public health organizations and health institutions as existing channels of influence.

A systematic DoE approach is developed to optimize Mo-based ZSM-5 catalyst recipe for methane dehydro-aromatization process. Aim is to achieve maximum benzene productivity with improve catalyst stability. Three major factors - Si/Al ratio of ZSM-5, pH of Mo incorporation and catalyst activation along with two different responses - benzene yield and final/peak methane conversion (or in other words the extent of catalyst stability) were considered for constructing the DoE. The benzene yield and final/peak methane conversion vary significantly depending on the catalyst recipe including the catalyst activation protocol/conditions. The combination of Si/Al ratio of 15, pH of Mo incorporation 10 and control catalyst activation by pre-carburization identified through DoE helped to achieve maximum/optimum benzene yield and the catalyst stability. Moderate acidity of zeolite, high Mo dispersion and presence of higher quantity of catalytically active Mo-carbide/oxycarbide species seems to be the reason for high benzene productivity and catalyst stability.

KEY POINTS A 70-year-old man presented to the emergency department with a 2-week history of rash, which started as a localized eruption on his forehead and progressed to a vesicular rash involving his entire body ([Figure 1][1]). Over this same period, he noted increasing shortness of breath

OBJECTIVE: To provide primary care physicians with clinical guidance for addressing parental vaccine hesitancy. SOURCES OF INFORMATION: The PubMed database was searched for English-language articles published in the 10 years before January 1, 2018. Search terms included vaccine hesitancy or confidence or acceptance, parents or children, and communication, counseling, or clinical practice. References of identified articles were assessed for additional relevant articles. A separate gray literature search was conducted using Google to find best-practice guidelines from public health and health care organizations, knowledge translation materials for health care providers, and resources that could be used in discussions with parents about vaccines. MAIN MESSAGE: Practical tips for addressing parental vaccine hesitancy in primary care include starting early, presenting vaccination as the default approach, building trust, being honest about side effects, providing reassurance on a robust vaccine safety system, focusing on protection of the child and community, telling stories, and addressing pain. Also provided are statements that providers could use in vaccination-related conversations; answers to commonly asked questions on benefits, safety, and immunologic aspects of vaccines; and links to a number of online resources for physicians and parents. CONCLUSION: Vaccine-hesitant parents who are on the fence far outnumber vaccine refusers; therefore, counseling this group might be more effective. Reasons behind vaccine hesitancy are complex and encompass more than just a knowledge deficit. As a trusted source of information on vaccines, family physicians play a key role in driving vaccine acceptance.

Background: In February 2018, Canada’s National Advisory Committee on Immunization recommended maternal vaccination with tetanus–diphtheria–acellular pertussis (Tdap) vaccine during pregnancy to prevent severe pertussis infection in young infants. This study assessed the relation between maternal Tdap vaccination and obstetric and perinatal outcomes in Ontario. Methods: We performed a population-based cohort study of all births from April 2012 to March 2017 using multiple linked health administrative databases. We used Cox regression with a time-dependent exposure variable to estimate adjusted hazard ratios (HRs) for preterm birth (< 37 wk), very preterm birth (< 32 wk) and stillbirth. We assessed remaining outcomes (gestational hypertension, chorioamnionitis, postpartum hemorrhage, severe postpartum hemorrhage, being small for gestational age, neonatal intensive care unit stay > 24 h, composite neonatal morbidity) using log-binomial regression to generate adjusted risk ratios (RRs). We adjusted estimates for potential confounding using propensity score weighting. Results: Of 615 213 infants (live births and stillbirths), 11 519 were exposed to Tdap vaccination in utero. There was no increased risk for preterm birth (adjusted HR 0.98, 95% confidence interval [CI] 0.91–1.06), very preterm birth (adjusted HR 1.10, 95% CI 0.86–1.41), stillbirth (adjusted HR 1.15, 95% CI 0.82–1.60) or being small for gestational age (adjusted RR 0.96, 95% CI 0.90–1.02). The risks of a neonatal intensive care unit stay exceeding 24 hours (adjusted RR 0.82, 95% CI 0.76–0.88) and neonatal morbidity (adjusted RR 0.81, 95% CI 0.75–0.87) were decreased. There was no association with chorioamnionitis (adjusted RR 1.17, 95% CI 0.99–1.39), postpartum hemorrhage (adjusted RR 1.01, 95% CI 0.91–1.13) or severe postpartum hemorrhage (adjusted RR 0.79, 95% CI 0.55–1.13), but we observed a reduced risk of gestational hypertension (adjusted RR 0.87, 95% CI 0.78–0.96). Interpretation: Our results complement evidence that maternal Tdap vaccination is not associated with adverse outcomes in mothers or infants. Ongoing evaluation in Canada is needed as maternal Tdap vaccination coverage increases in coming years.

Needle fear typically begins in childhood and represents an important health-related issue across the lifespan. Individuals who are highly fearful of needles frequently avoid health care. Although guidance exists for managing needle pain and fear during procedures, the most highly fearful may refuse or abstain from such procedures. The purpose of a clinical practice guideline (CPG) is to provide actionable instruction on the management of a particular health concern; this guidance emerges from a systematic process. Using evidence from a rigorous systematic review interpreted by an expert panel, this CPG provides recommendations on exposure-based interventions for high levels of needle fear in children and adults. The AGREE-II, GRADE, and Cochrane methodologies were used. Exposure-based interventions were included. The included evidence was very low quality on average. Strong recommendations include the following. In vivo (live/in person) exposure-based therapy is recommended (vs. no treatment) for children seven years and older and adults with high levels of needle fear. Non-in vivo (imaginal, computer-based) exposure (vs. no treatment) is recommended for individuals (over seven years of age) who are unwilling to undergo in vivo exposure. Although there were no included trials which examined children < 7 years, exposure-based interventions are discussed as good clinical practice. Implementation considerations are discussed and clinical tools are provided. Utilization of these recommended practices may lead to improved health outcomes due to better health care compliance. Research on the understanding and treatment of high levels of needle fear is urgently needed; specific recommendations are provided. Canadian Institutes of Health Research, The Mayday Fund

To describe updates to the Preventive Care Checklist Form© to help family physicians stay up to date with current preventive health care recommendations.The Ovid MEDLINE database was searched using specified key words and other terms relevant to the periodic health examination. Secondary sources, such as the Canadian Task Force on Preventive Health Care, the Public Health Agency of Canada, the Trip database, and the Canadian Medical Association Infobase, were also searched. Recommendations for preventive health care for average-risk adults were reviewed. Strong and weak recommendations are presented on the form in bold and italic text, respectively.Updates were made to the form based on the Canadian Task Force on Preventive Health Care recommendations on screening for obesity (2015), cervical cancer (2013), depression (2013), osteoporosis (2013), hypertension (2012), diabetes (2012, 2013), and breast cancer (2011). Updates were made based on recommendations from other Canadian organizations on screening for HIV (2013), screening for sexually transmitted infections (2013), immunizations (2012 to 2014), screening for dyslipidemia (2012), fertility counseling for women (2011, 2012), and screening for colorectal cancer (2010). Some previous recommendations were removed and others lacking evidence were not included.The Preventive Care Checklist Form has been updated with current recommendations to enable family physicians to provide comprehensive, evidence-based care to patients during periodic health examinations.

This article reports about the development of various discrete (single sensor) surface acoustic wave (SAW) handheld sensor systems, for detection and quantification of explosives and chemical warfare agents (CWA). The sensing element is a SAW device of delay line, resonator or dispersive delay line type with frequency of operation ranging from 36 MHz to 434 MHz. The SAW devices are coated with various polymers having good selectivity to explosives and CWA. Oscillator with the SAW device in the feedback loop as a frequency determining element is used. Dual oscillator configuration with one coated and one uncoated SAW device is used. The outputs of the oscillators are mixed and signal conditioned before frequency measurement. The frequency measurement is carried out by a high-speed high-resolution reciprocal counting method using microcontroller-based readout circuitry. Data acquisition software written in Visual Basic performs online display and storage. The performance of various parts and the sensor systems is analyzed for their stability, resolution, accuracy and sensitivity.

With an aim to probe some of the safe and commercially available nonsulfur chemicals as simulants of sulfur mustard for testing of protective materials, the sorption of bis(2-chloroethyl) ether (2-CEE), 1,6-dichlorohexane, bis(4-chlorobutyl) ether, n-octane (OCT), dimethyl methylphosphonate, and ethylene glycol through butyl rubber (IIR) and polyisoprene (PI) rubber was studied at 30 ± 2°C using gravimetric method. Among these compounds, sorption of OCT was maximum while bis(4-chlorobutyl) ether was sorbed least. The sorption of dimethyl methylphosphonate was intermediate between 2-CEE and 1,6-dichlorohexane. With the exception of OCT/IIR, OCT/PI, and 2-CEE/PI, all other simulant/elastomer systems showed non-Fickian behavior, implying the potential of OCT as a model compound. The diffusivity of OCT was investigated in IIR and PI; the diffusion coefficient values for OCT/IIR and OCT/PI systems differed by one order of magnitude, being 6.95 × 10−15 m2/s and 3.74 × 10−14 m2/s, respectively, indicating the relative impermeability of IIR. The magnitude and dynamics of sorption in OCT/IIR as a function of its concentration and the amount of filler were further studied using the automated gravimetric analyzer. Incorporation of carbon black in IIR further reduced the extent of sorption, thereby implying an improvement in barrier performance. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1801–1806, 2007

Active carbon, grade 80 CTC, of surface area 1199m(2)/g, 12x30 BSS particle size and coconut shell origin was impregnated (5%, W/W) with various impregnants such as Cu(II) 1,1,1,5,5,5-hexafluoroacetylacetonate, Cu(II) 1,1,1-trifluoroacetylacetonate, 1-phenylbute-1,3-dione-2-oxime plus Cu(II) using incipient wetness technique. These impregnated carbons along with active carbon (Grade 80 CTC) and whetlerite were studied for the adsorption of dimethyl methylphosphonate (DMMP) at 33+/-1 degrees C under static conditions. Cu(II) 1,1,1,5,5,5-hexafluoroacetylacetonate impregnated carbon system showed highest uptake (68.5%, W/W) of DMMP amongst all the carbon systems, however, active carbon with higher surface area could adsorb 61.5% (W/W) of DMMP under same conditions. It indicated that the adsorption by Cu(II) 1,1,1,5,5,5-hexafluoroacetylacetonate impregnated carbon was not only due to physisorption but chemisorption as well. Kinetics of adsorption was also studied and various parameters such as equilibration time, equilibration capacity, rate constant (k), diffusional exponent (n) and constant (K) were determined. Carbons with and without DMMP exposure were also studied using IR and TGA techniques. Reaction products were analyzed using gas chromatography coupled with mass spectrometry (GC/MS) and found to be methyl methylphosphonic acid (MMPA) and methylphosphonic acid (MPA) for Cu(II) 1,1,1,5,5,5-hexafluoroacetylacetonate impregnated carbon.

Poly(vinyl acetal) PVAc was synthesized by the acid-catalyzed acetalisation of poly(vinyl alcohol). Three different morphologically modified variants of the polymer were prepared by the addition of supramolecules; namely α and β cyclodextrins (CD) and butyl calixerene (calix) to the PVAc sol. 20% (w/v) of the solution of the polymers in tetrahydrofuran (THF) was used to cast the membranes. These membranes were characterized using spectroscopic and thermoanalytical techniques, and also tested for their chemical resistance and mechanical strength. The pervaporative behaviour of modified membranes vis-a-vis PVAc for the separation of a wide composition of benzene (Bz)/cyclohexane (Chx) mixtures was evaluated. Addition of αCD or calix to PVAc reduced the overall flux while dispersion of βCD favoured an enhanced flux especially in the Bz-lean and azeotropic region.

Polyethylene maleate (PEM) was synthesised by direct polycondensation of maleic anhydride and ethylene glycol in toluene under reflux usingp-toluene sulphonic acid as a catalyst. Structure of PEM was further modified by varying nature of diols and acid components, chain length of glycols, incorporation of aromatic and fluorine groups in the chain. Formation of PEM was monitored by gas chromatography. The parameters like degree of polymerisation, number average molecular weight (Mn), and weight average molecular weight (Mw) were calculated from the extent of reaction and stoichiometric ratio of the reactants. The number average molecular weight was also determined using Knauer vapour pressure osmometer. Cohesive energy, volume, and solubility parameters of PEM-based copolyesters were calculated by group contribution method. These PEM-based copolyesters’ have been evaluated as sorbent-coating materials for the detection of organ0 phosphorus(OP)compo using dimethylmethylphosphonate (DMMP) as model compound and piezoelectric crystal detector. PEMbisphenol A is found to be the most sensitive and potential coating material for the detection of OP compounds using piezoelectric crystal detector. Potential PEM-based copolyesters have been characterised by viscosity, infrared spectroscopy, NMR spectroscopy, Mn and thermal stability.

A simpler technique for the synthesis of 2,2-bis(4-allyoxyphenyl)hexafluoropropane has been achieved from 4,4′-(hexafluoroisopropylidene)diphenol for obtaining 2,2-bis(3-allyl-4-hydroxyphenyl)hexafluoropropane. This monomer and its corresponding hybrid organic/inorganic siloxane polymer are successfully used as a coating material for the detection of toxic chemical warfare agents.

Cellulose membrane produced by bacterial Acetobacter xylinum was deproteinated and investigated for pervaporative separation of aqueous organic mixtures. The permeate flux, selectivity, pervaporation separation index (PSI), solubility and degree of sorption were studied as a function of increasing concentration of organics in the feed. The membrane was found highly selective to water; highest selectivity [αp = 186] was obtained for a mixture of trihydric alcohol viz. glycerol (Gly) with 40% (v/v) water. The binary system of monohydric alcohol viz. ethanol (EtOH) and water (40% (v/v)) showed the lowest selectivity [αp = 12] but the highest pervaporative flux of 614 gm−2 h−1 at 35 °C which further increased to 1429 gm−2 h−1 at 75 °C. However, selectivity decreased to 1.3 with the increase in temperature. The pervaporation behaviour was interpreted in terms of sorption and diffusivity of the organics, which in turn, was influenced by the extent of their hydrogen bonding with the cellulose units in the membrane and the plasticization induced by the permeating water present in the binary mixture. Substantially high pervaporative separation index (PSI) of the order of 103–104 gm−2 h−1 and comparatively lower energy of activation (Ej) of 10 kJ/mol is indicative of the pervaporative potential of the bacterial cellulose membrane (BCM) in the separation of aqueous binary mixtures.

The pervaporative (PV) performance with respect to the separation of ethanol/water (EtOH/H2O) azeotrope was assessed for a bacterial cellulose membrane (BCM) impregnated with chitosan (CTSN), designated as CTSN–BCM. The PV potential of CTSN–BCM was compared with that of parent polymers and also with the blends of CTSN with poly(vinyl alcohol) (PVA). The blends and CTSN–BCM were characterized using spectroscopic and thermoanalytical techniques, and also tested for their mechanical strength and sorption of EtOH/H2O mixtures. While PVA and the blends tend to dissolve at higher concentration of water, CTSN–BCM was found to be intact over the entire composition range. When evaluated against pervaporation of 95:5 w/w EtOH/H2O azeotrope at 24 ± 1 °C; CTSN–PVA (1:1) blend showed comparatively higher selectivity (22.0) but a poorer flux (1.7 kg μm m−2 h−1). The flux was significantly higher (42.8 kg μm m−2 h−1) in CTSN–BCM and selectivity (∼10) was at par with PVA. The temperature dependence of selectivity and flux through CTSN–BCM was also investigated. Substantially high pervaporative separation index (PSI) of the order of 350 kg μm m−2 h−1 and low energy of activation of 10 kJ/mol is indicative of the potential of CTSN–BCM in the pervaporative separation of EtOH/H2O azeotrope.

The heart of a chemical sensor based on bulk or surface acoustic wave devices is a polymer-coated piezoelectric substrate that selectively sorbs and concentrates the target analyte vapors. The development of such sensors often necessitates the screening and evaluation of suitable polymeric interface materials meeting the specified sensitivity and selectivity toward the analytes of interest. The magnitude and dynamics of sorption–desorption of the vapors in the polymer and the extent of polymer–vapor interactions largely determine the performance of a sensor. The standard protocol used for the purpose is rather tedious, involving the generation and calibration of individual analyte vapors, with stringent control on temperature, humidity, and test parameters. This article outlines four different alternative techniques based on mass uptake of the analyte vapors, on its partitioning in polymers, or both, which in combination can determine the characteristics of an interface material used for coating a piezoelectric substrate in acoustic wave-based chemical sensors. These methods were applied to poly(ethylene maleate), a representative interface material. The analytes ranged from volatile organic chemicals to sarin—a chemical warfare agent—and its simulant, dimethyl methylphosphonate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3428–3432, 2004

Poly(vinyl alcohol) (PVA) was chemically modified by acid-catalysed acetalisation, resulting in the formation of poly(vinyl acetal) (PVAc). The addition of a molecular recognition compound, namely, O , O -bis(diethoxyphosphoryl)- tert -butyl calixarene (calix) to the PVA sol, yielded the morphologically modified membranes, designated as PVA–calix. These membranes were characterised using spectroscopic and thermoanalytical techniques, and also tested for their chemical resistance, mechanical strength and pervaporative behaviour towards benzene (Bz)/cyclohexane (Chx) mixtures. The polymers were found to be selective towards Bz. When evaluated against pure Bz and Chx at 27±1 °C; PVA–calix showed an ideal selectivity tending towards infinity but a poor flux (5.9 kg μm/(m 2 h)) for Bz. The flux of Bz was significantly higher in PVAc and increased from 20 kg μm/(m 2 h) for 20% (v/v) Bz/Chx mixture to 65.8 kg μm/(m 2 h) for pure Bz. The swelling index also increased with the increasing concentration of Bz in the feed. Pervaporation in PVAc was thus sorption-controlled. The sorption isotherms for the pure components in PVAc were also obtained using an automated sorption analyser based on the principle of mass relaxation of the polymer accompanying vapour sorption. The high interaction of PVAc with Bz was interpreted in terms of solubility parameters and free volume in the polymer.

Hydrophobic comonomers bisphenol-A and hexafluorobisphenol-A were incorporated as diol components in the sensor-coating material poly(ethylene maleate) (PEM), resulting in modified polymers, HCPEM and HFPEM, respectively. To assess the suitability of these polymers as sensor interfaces, the sorption/desorption isotherms and kinetics of water and a range of volatile organic vapors were obtained over the entire relative pressure range of 0.1 to 1.0, using an automated intelligent gravimetric sorption analyzer. The extent and rate of sorption of organic vapors were higher in the modified polymers compared to those of the parent polymer. Sorption hysteresis was observed at high relative pressures, especially with water and other hydrogen-bonded polar organic vapors. Polarizable vapors like toluene and benzene were sorbed more than nonpolarizable cyclohexane vapors. The sorption results were interpreted in terms of semiempirical models based on concepts of thermodynamic interaction parameter, partition coefficient, and linear solvation energy relationship. The study reveals the potential of sorption/desorption isotherms and kinetics in characterizing the sorption properties of coating materials that are used as an interface in acoustic wave sensors. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1760–1767, 2003

Cellulose membrane produced by the bacterium Acetobacter xylinum was deproteinated and investigated for pervaporation (PV) of binary water–ethanol mixtures. The membrane was characterised using elemental analysis, infra-red spectroscopy, scanning electron microscopy as well as for mechanical strength and sorption characteristics. A batch stirred cell was used to study the PV behaviour of water–ethanol mixtures through the membrane. The permeate flux, selectivity, PV separation index (PSI), solubility and degree of sorption were studied as a function of increasing ethanol concentration in the feed. The membrane was found highly selective to water. Even when the feed was rich in ethanol (>70% (w/w)) the permeate contained higher than 95% (w/w) of water. For feed compositions containing less than 30% water, the selectivity towards water was in the range of 125–287, the flux was greater than 100 g/m2 h and PSI was of the order of 104 g/m2 h.

The diffusion of sulfur mustard (SM), a chemical warfare agent, through butyl (IIR) and nitrile (NBR) rubber membranes was studied with a standard spot disc breakthrough time test at temperatures ranging from 298 to 333 K. The mechanism of diffusion was interpreted on the basis of an Arrhenius relation and dynamic adsorption theory. The permeant SM was pictured to reversibly dwell at each adsorption site for about 1.5 × 10−13 s and hop randomly through the polymer matrices in small steps, with jump lengths of the order of a picometer. A comparatively lower activation energy, a solubility parameter closer to that of SM, and a lower thermodynamic interaction parameter also contributed toward faster uptake of SM by NBR in comparison with IIR. The diffusion data were also used to derive the collision diameter of SM in these polymer matrices. © 2002 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 40: 1821–1827, 2002

Bis(2-chloroethyl)ether, a nonvesicant and easy to handle chemical, was proposed as a model compound for the vesicant sulfur mustard (SM) in routine permeation testing of protective devices. The proposition was based on detailed studies on sorption of these chemicals in elastomers. From the sorption plots and permeation parameters, it was found that the model compound diffuses faster than SM, and the diffusion follows Fickian kinetics. Free volume models, such as those developed by Lee and Salame, together with solubility and thermodynamic interaction parameters, validated the observed sorption phenomenon and afforded a criterion for predicting the barrier properties of elastomers. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2472–2479, 2000

Butyl rubber (IIR) membranes containing a 0–50% volume fraction of carbon black (GPF N660) or nonblack fillers (talc/precipitated CaCO3/fullers earth) were prepared by solution casting and evaluated for permeation resistance to the vesicant, bis(2-chloroethyl)sulfide, or sulfur mustard (SM) and its oxygen analog (OA), bis(2-chloroethyl)ether. The diffusivity of the chemicals was determined from the breakthrough time (BTT), obtained using the spot disc test and a gravimetric method. The permeation parameters, calculated from the sorption data, were used to determine an optimum filler content for maximum protection against SM. To investigate the effect of carbon loading on the permeation properties of IIR, the permeation of SM and OA in carbon-loaded black membranes was compared with nonblack membranes and interpreted in terms of the dispersion of carbon in the membranes. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 69: 503–511, 1998

An investigation was made of the effect of the nature of elastomer, thickness of the membrane and its formulation, and the temperature and relative humidity of the surroundings, on the permeation of bis(2-chloroethyl)sulfide (SM), a well-known chemical warfare agent, through solution-cast elastomer membranes. The permeation was evaluated in terms of the breakthrough time of the agent through the membrane, using the spot disk test and the weight gain method. Butyl rubber exhibited the highest permeation resistance, which increased linearly with thickness and was increased by incorporation of an optimum of 20 phr carbon black in the membranes. Increase in temperature and relative humidity lowered the permeation resistance. The observed data were correlated with permeation parameters and it is postulated that permeation of SM through elastomers is non-Fickian in nature.

Coconut charcoals of different grades were studied for assessing the removal efficiency of chemical warfare (CW) agents from aqueous solutions. Oxygen analogue of sulphur mustard and phenol were used as model compounds for CW agents for adsorption studies. Freundlich and Langmuir adsorption isotherms were plotted. Equilibrium constant and maximum adsorption capacity for carbons were computed from the isotherm data. These studies enabled identification of an activated carbon suitable for use in reverse-osmosis water filtration systems.

The present review surveys, integrates and gives a bibliographic account of studies carried out on the degradation of butyl rubber over the last few decades. Our objective was to extract the useful information from such studies. As a large fraction of the related literature is in inaccessible journals, many of which are not readily available in English translation, this paper should help in presenting an overview and insight into the nature of the work being done in the field. The effects of thermal and thermo-oxidative conditions, mechanical stresses (during processing and ultrasound treatment), catalysts, chemicals, ozone and radiation on the structure, and physicomechanical properties of butyl rubber have been discussed. This rubber was chosen as a representative elastomer in order to illustrate some trends in the degradation studies of other rubbers.

INTRODUCTION: Despite the availability of a variety of evidence-based interventions, it has previously been reported that the majority of infants and children undergo vaccine injections without the benefit of analgesia. Nurses in public health administer a substantial number of injections; however, their attitudes and practices surrounding acute pain during vaccine injections have not been previously explored.METHODS: A focus-group interview was conducted in Toronto, Ontario, with 10 nurses who immunize children. Participants reported their perceptions and practices with regard to vaccine injection pain and pain management.RESULTS: Three key themes emerged: environmental and process factors, perceptions regarding the effectiveness of different analgesic interventions, and perceptions regarding pain and fear. Participants reported a lack of control over their environment, resulting in fear and discomfort for children. They recommended increased support from external partners such as school teachers and administrators. Participants reported that pharmacological interventions, such as topical local anesthetics, were not used; however, psychological and physical interventions were commonly used. Nurses questioned the effectiveness of topical anesthetics, and indicated that more education was required regarding effective analgesic interventions. Needle pain was reported to be the most prominent concern for children undergoing vaccine injections, and children were described as being fearful.DISCUSSION: Nurses reported vaccination setting, analgesic effectiveness and relative importance given to pain as important factors for pain and pain management during vaccine injections. Future studies should explore whether additional perspectives are present in vaccinators in other geographical regions. The effectiveness of educational resources and pain management programs aimed at improving current practices should be investigated.

Butyl rubber was pyrolysed under an inert atmosphere in a furnace-type pyrolyser at 400°C. The pyrolysate was trapped cryogenically and analysed by GC, GC/MS and GC/FT-IR. Based on these data, a mechanism for the thermal degradation of butyl rubber is proposed. The effect of temperature on the reative yields of the major decomposition products was also studied.

Injections for vaccinations, the most common source of iatrogenic pain in childhood,[1][1] are administered repeatedly to almost all Canadian children throughout infancy, childhood and adolescence.[2][2] The pain associated with such injections is a source of distress for children, their parents and

Curvularia lunata was found causing (disseminated phaeohyphomycosis among a group of Nezara viridula (Insecta:Heteroptera) parasitizing vegetable crop Vigna unguiculata. Dark lesions were seen on pronotum and abdominal sterna. Experimental lesions were produced by applying 0.1 ml of 6.2 × 108cfu/ml−1 on abdominal sterna. Histopathology revealed that almost all internal organs and tissues showed extensive damage. It is interesting to note that C. lunata exhibited predeliction for chitinous tissues and elicited cellular immune response by granulocytes (phagocytosis). This is the first report of phaeohyphomycosis of an insect, extending the disease to invertebrates.

The protective potential of protective devices such as respirators, suits, gloves, and overboots is widely evaluated using the standard colorimetric test (spot disc breakthrough time test, also called SD BTT) involving sulfur mustard (SM) as the challenge chemical. The vesicant nature of SM makes the test inconvenient and poses stringent safety demands. Moreover, such tests are allowed only at a limited number of facilities, causing delay in product development and supply. This prompted the present study on the search for suitable SM simulant responsive to SD BTT test. The diffusivities at BTT (DBTT) of 10 commercially available thiocompounds through butyl rubber (IIR) were compared vis-a-vis DBTT of SM. For three representative thiocompounds, namely methyl (phenyl thio)acetate, 2-chloroethyl phenyl sulfide (2-CEPS) and phenyl-n-propyl sulfide (PNPS), the transport parameters through IIR were obtained. PNPS and 2-CEPS were further compared with respect to DBTT in elastomers such as IIR, ethylene–propylene–diene methylene rubber, polydimethylsiloxane, nitrile rubber, polybutadiene, and natural rubber. 2-CEPS showed generally same order of DBTT as SM implying its potential use as a simulant. The transport parameters for various 2-CEPS/elastomer systems were also determined. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009