PM2.5 elemental composition in indoor residential environments and co-exposure effects on respiratory health in an industrial area.

This study aimed to identify and characterise indoor sources of particulate matter (PM) in domestic environments. 74 inhabited apartments located in the urban area of Gela (Sicily, Italy), close to a refinery, and in three villages of the hinterland were evaluated, in real-world conditions, for the elemental composition of PM2.5. The samples were collected simultaneously inside and outside each apartment for 48 h. In addition, two of the apartments were simultaneously studied for four weeks. The elemental composition of PM2.5 was determined by applying a chemical fractionation procedure followed by inductively-coupled plasma spectrometry analysis, with both optical emission and mass detection. The extractable, more bio-accessible fraction (ext), and the mineralised residual fraction (res) of each element were determined, thus increasing the selectivity of elements as source tracers. Indoor air in the considered apartments was affected by both outdoor pollution and specific indoor emission sources. The behaviour of each source was studied in detail, identifying a reliable tracer: Tires for soil, Asext for industrial sources, Vext for heavy oil combustion, Ce for cigarette smoking and Mo for the use of vacuum dust cleaners. Asext and Vext showed an excellent infiltration capacity, while the concentration of Tires was affected by a low infiltration capacity and by the contribution of particles re-suspension caused by the residents' movements. In the case of Ce and Mo, indoor concentrations were much higher than outdoor with a high variability among the apartments, due to the inhabitants' habits concerning cigarette smoke and use of electric appliances. To test the overall effect of the concomitant exposure to the identified sources on Wh12 M and on DDA, a WQS analysis was conducted. Cigarette smoking and heavily oil combustion driven the Wh12 M odds increase, while the DDA odds increase was mainly driven by heavily oil combustion and the use of vacuum dust cleaners.

Impact of exclusive e-cigarettes and heated tobacco products use on muco-ciliary clearance.

BACKGROUND: Tobacco smoking impairs mucociliary clearance (MCC) efficiency as shown by prolonged saccharin test transit time (STTT). Avoiding exposure to tobacco smoke from combustible cigarettes may restore MCC function and former smokers have been shown to exhibit similar STTT as never smokers. The impact on STTT of switching from smoking to combustion-free tobacco products such as e-cigarettes (ECs) and heated tobacco products (HTPs) is not known. METHODS: We report STTT of exclusive EC and HTP users. Test results were compared with those obtained in current, former, and never smokers. RESULTS: STTT were obtained from 39 current, 40 former, 40 never smokers, and from 20 EC and 20 HTP users. Comparison of STTT values showed significant difference among the five study groups (p < 0.00001) with current smokers having a median [interquartile range (IQR)] STTT of 13.15 min, which was significantly longer compared with that of all other study groups. In particular, compared with former (7.26 min) and never smokers (7.24 min), exclusive EC users and exclusive HTP users had similar STTT at 7.00 and 8.00 min, respectively. CONCLUSION: Former smokers who have switched to exclusive regular use of combustion-free nicotine delivery systems (i.e., ECs and HTPs) exhibit similar saccharin transit time as never and former smokers. This suggests that combustion-free nicotine delivery technologies are unlikely to have detrimental effects on MCC function.

A double blind randomized controlled trial investigating efficacy and safety of varenicline for smoking cessation in patients with type 2 diabetes: study protocol.

Reducing exposure to cigarette smoke is an imperative for public health and for diabetic patients. Patients with diabetes who continue to smoke face challenges at quitting and the delivery of effective smoking cessation interventions is a major unmet need. The high-affinity α4ß2 nicotinic acetylcholine receptor partial agonist varenicline in combination with counseling is effective for smoking cessation, but evidence in patients with diabetes is limited. A clinical trial of varenicline targeted specifically at smokers with T2DM is warranted. This randomized, double blind, placebo-controlled trial will be the first study to test efficacy and safety of varenicline in smokers with type 2 diabetes mellitus (T2DM) over the course of 52 weeks. We hypothesize that varenicline treatment (1 mg BID, administered for 12 weeks) would increase quit rates, maintain smoking abstinence up to 1 year after treatment, and be well-tolerated in T2DM smokers intending to quit. Efficacy end points will include carbon monoxide-confirmed continuous abstinence rate (CAR) and 7-day point prevalence of abstinence. The results of this RCT will help inform medical/health authorities and physicians worldwide whether an optimally varenicline-treated cohort of T2DM patients who smoke will experience significant success rates, without significant side effects.Trial registration NCT01387425 ( https://clinicaltrials.gov/ct2/show/NCT01387425 ).

Rare earths and trace elements contents in leaves: A new indicator of the composition of atmospheric dust.

The relationship between the trace element distribution in atmospheric particles and leaves of some exposed plants in the environment was recently demonstrated. This indication would suggest that the trace element analysis of leaves in these plants could provide information about the composition, nature and origin of the atmospheric dust dispersed in the environment. In order to corroborate this hypothesis, the distribution of trace elements and Rare Earths were studied in leaves of some endemic plants, in the atmospheric fallout and in soils of rural, urban and industrial ecosystems in Sicily. These elements have been chosen to discriminate the source and nature of different source on atmospheric dust and the larger capability of the composition of the latter materials to influence the metal ion distribution in leaves of studied plants rather than the soil composition. These evidences are related to the recognition both of positive La anomaly and trace element enrichments in studied leaves and to their particular V/Th and Co/Ni signature. On the other hand, some particular normalised REE features recognised in leaves suggest that a limited contribution to the REE budget in studied leaves is provided by the REE migration from roots.

Third-hand smoke exposure and health hazards in children.

Smoking still represents a huge public health problem. Millions of children suffer the detrimental effects of passive smoking. An increasing number of countries have recently issued laws to regulate smoking in public places. Instead, homes remain a site where children are dangerously exposed to environmental tobacco smoke (ETS). The combination of tobacco smoke pollutants which remain in an indoor environment, the so-called 'third-hand smoke' (THS), represent a new concept in the field of tobacco control. THS consists of pollutants that remain on surfaces and in dust after tobacco has been smoked, are re-emitted into the gas-phase, or react with other compounds in the environment to form secondary pollutants. Indoor surfaces can represent a hidden reservoir of THS constituents that could be re-emitted long after the cessation of active smoking. Human exposure to THS pollutants has not yet been thoroughly studied. Infants and children are more prone to the risks related to THS exposure than adults because they typically spend more time indoors and have age-specific behaviours that may expose them to potential health hazards from THS. Further investigations are warranted to study the health effects of THS relevant to different exposure pathways and profiles. It would also be very important to evaluate how THS may affect the lung development through the in utero exposure during the pre-natal life. We aimed at reviewing recent findings published about THS, with special reference to the effects on children's health.

Concentration and reference interval of trace elements in human hair from students living in Palermo, Sicily (Italy).

Trace element contents in specimens of hair collected from 137 children aged 11-13 years old, living in Palermo (Sicily, Italy) were determined by ICP-MS. This work reports analytical data for the following 19 elements: Al, As, Ba, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Rb, Sb, Se, Sr, U, V and Zn. The most abundant chemical elements were zinc and copper (Zn > Cu), with concentrations exceeding 10 µg/g (Zn = 189.2 µg/g; Cu = 22.9 µg/g). Other elements with concentrations greater than 1 µg/g were, in order of abundance, Al>Sr>Ba>Pb. The remaining elements were all below 1 µg/g. The average elemental concentrations in hair were statistically compared by Kolmogorov-Smirnov's test taking children's gender into account. Al, Ba, Cr, Li, Rb, Sb, Sr, V and Zn were statistically different according to gender, with significance p < 0.001. This study thus confirms the need for hair analysis to differentiate female data from those of males. IUPAC coverage intervals and coverage uncertainties for trace elements in the analysed hair samples are also reported.

Effect of a nicotine-free inhalator as part of a smoking-cessation programme.

Smoking-cessation drugs are inadequate at addressing the behavioural component of tobacco dependence. Nicotine-free inhalators are plastic devices that may provide a coping mechanism for conditioned smoking by replacing some of the rituals associated with smoking gestures. This study assessed the effect of using a nicotine-free inhalator to improve success in a cessation programme. At baseline, 120 smokers attending a smoking-cessation programme were assessed for their sociodemographic factors, smoking history, depression, physical and behavioural dependence, and motivation. Participants were randomly assigned to two groups, nicotine-free inhalator group (PAIPO; Echos Srl, Milan, Italy) versus reference group. For the whole sample, no significant difference was found in quit rates at 24 weeks between the PAIPO group and the reference group. However, the quit rate in the PAIPO group (66.7%) was more than three-fold higher than the reference group (19.2%) for those individuals with high Glover-Nilsson Smoking Behavioural Questionnaire (GN-SBQ) scores at baseline. The results of the logistic model analysis indicate that a high GN-SBQ score is a strong independent predictor for successful quitting at 24 weeks (OR 8.88; 95% CI 2.08-37.94) in the PAIPO group. Nicotine-free inhalators may be beneficial when used in the context of smoking-cessation interventions, particularly for those smokers for whom handling and manipulation of their cigarettes plays an important part in the ritual of smoking.

Assessment of exposure to environmental tobacco smoke in young adolescents following implementation of smoke-free policy in Italy.

We investigated acute and chronic exposure to environmental tobacco smoke (ETS) in a cohort of young adolescents using urinary cotinine and hair nicotine testing after recent implementation of Italian smoke free legislation. Study subjects were 372 Italian young adolescents, between 10 and 16 years of age from the principal city of Sicily, Palermo. Urine and hair samples were collected between November 2005 and May 2006, when the legislation to ban smoking in all the enclosed places of employment (including bars, restaurants, pubs) was completely enforced. An exhaustive questionnaire including sociodemographic characteristics and active and passive exposure to cigarette smoking was completed. Urinary cotinine was analyzed by radioimmunoassay and hair nicotine by a validated GC/MS method. Based on urinary cotinine results, 2.1% and 89% of the study participants, respectively, showed non-exposure and low acute exposure to ETS, whereas only 1.6% presented very high exposure or a hidden active smoking habit in the recent past. Hair nicotine disclosed non-exposure and low exposure to ETS in 11.8% and 65.6% of the young adolescents, respectively, taking into consideration a larger time-window. High repeated exposure, suggesting active smoking in some cases was observed in 8.6% of the study subjects. Hair nicotine was inversely related to educational level of the adolescents' parents. Overall, due to the implementation of smoke-free legislation and information campaign against smoking, a significant trend toward low exposure to ETS was observed in this study cohort with no association between exposure to ETS and respiratory illnesses.

Bronchial hyperresponsiveness in children with atopic rhinitis: a 7-year follow-up.

BACKGROUND: A high prevalence of bronchial hyperresponsiveness (BHR) was found in atopic subjects with rhinitis. Those subjects may be at higher risk for developing bronchial asthma. We evaluated, in a 7-year follow-up, BHR and atopy in a homogeneous population of nonasthmatic children with allergic rhinitis (AR), and their role in asthma development. METHODS: Twenty-eight children (6-15 years) with AR were studied. At enrollment (T(0)), skin tests, total serum IgE assay, peak expiratory flow (PEF) monitoring and methacholine (Mch) bronchial challenge were performed. BHR was computed as the Mch dose causing a 20% forced expiratory volume (FEV)(1) fall (PD(20)FEV(1)) and as dose-response slope (D(RS)). Subjects were reassessed after 7 years (T(1)) using the same criteria. RESULTS: At T(0), 13 children (46%), showing a PD(20)FEV(1) <1526 microg of Mch, had BHR (Mch+), although PEF variability (PEFv) was within normal limits. None of the children with negative methacholine test developed bronchial asthma after 7 years. Of the 13 Mch+, only two reported asthma symptoms after 7 years. No significant change was seen in the other parameters of atopy considered. CONCLUSION: Children with allergic rhinitis present a high prevalence of BHR. Nevertheless, their PEFv is normal and the rate of asthma development low.

Nocturnal asthma and gastroesophageal reflux.

Bronchial asthma is a complex disease involving various cyclic environmental and chronobiologic factors. In patients with asthma, nocturnal gastroesophageal reflux (GER) has been associated with triggering and worsening bronchoconstriction. There are data to suggest that the prevalence of GER is higher in patients with asthma than in the general population and that GER is directly associated with asthma severity. However, the role of GER in asthma remains controversial; some studies suggest that reflux does not mediate nocturnal asthma symptoms. This article reports the results from a study conducted in 7 adult patients affected by nocturnal asthma and moderate to severe GER disease. The relation between GER and asthma was tested by continuously and simultaneously monitoring respiratory resistances and esophageal pH. The study demonstrated a significant correlation between lower respiratory resistances and spontaneous GER. More specifically, both long (more than 5 minutes' duration) and short (5 minutes' or less duration) GER episodes elicited bronchoconstriction in patients with asthma who had moderate to severe GER disease. The severity and duration of bronchoconstriction were related to the duration of GER.

Changes in FVC during methacholine-induced bronchoconstriction in elderly patients with asthma: bronchial hyperresponsiveness and aging.

STUDY OBJECTIVE: We evaluated whether aging may produce changes in bronchial hyperresponsiveness, risk of enhanced bronchoconstriction, and changes of bronchoconstriction perception. SETTING: Each subject underwent a methacholine bronchial challenge. Methacholine challenge was stopped when one of the following conditions occurred: (1) plateau of bronchoconstriction; (2) decrease of FEV(1) > 40%; (3) FEV(1) drop below 1 L; or (4) excessive respiratory discomfort. Methacholine dose-response curves were plotted both for FVC and FEV(1). The provocative dose of methacholine causing a 20% decrease in FEV(1) with respect to baseline (PD(20)) and the fall in FVC (DeltaFVC) at PD(20) were computed. The Borg scale was used for scoring the perception of respiratory discomfort. PATIENTS: We compared 17 young asthmatic patients (aged 22 to 45 years) with 17 older asthmatic patients (aged 63 to 78 years) selected on the basis of similar baseline pulmonary function and disease duration. RESULTS: No significant between-group difference was found in PD(20) and in plateau development. Conversely, DeltaFVC was significantly higher in the older group (mean +/- SD, 15.5 +/- 3.9% vs 11.6 +/- 5.5% in younger patients). In addition, DeltaFVC showed a positive linear relationship with age (p = 0.0026). Elderly subjects were less aware of bronchoconstriction during the methacholine challenge (p = 0.04). CONCLUSIONS: In elderly patients with asthma having comparable pulmonary function and disease duration, bronchial responsiveness is not different from that observed in younger asthmatic patients. Nevertheless, in such patients, an age-related tendency to an enhanced bronchoconstriction and a reduced perception of the degree of bronchoconstriction exist.

Prevalence of nocturnal asthma in a general population sample: determinants and effect of aging.

Nocturnal asthma (NA) is important because of clinical and prognostic implications. Previous data on prevalence may be overestimated, because they are derived from selected series. Observations on monitoring of peak expiratory flow in elderly asthmatics suggested that prevalence of NA may increase with age. This study was designed to estimate the prevalence of NA-related symptoms in a sample drawn from a general population and evaluate the role of aging. Subjects (1,100, mean age 41.9, SD 22.8 years) were randomly selected from the lists of seven general practitioners. A questionnaire on nighttime and morning NA-associated symptoms was used and frequency of occurrence was rated as never, sometimes (less than once a week), and often (once a week or more). In the overall sample, symptoms were experienced "sometimes" by 2.3%-4.9% of subjects, whereas the response "often" was given by 0.9%-1.6% of subjects. Among subjects with a diagnosis of asthma, symptoms occurred sometimes in 16.7%-23.7% and often in 5%-15%. Symptoms reported the morning after were significantly more frequent among patients aged 65 years and older (p < 0.005), whereas the difference for nighttime symptoms was not statistically significant in different age groups, confirming an age-related blunted sensitivity. Logistic regression analysis shows that a diagnosis of asthma is the most important correlate of symptoms, with odds ratio (OR) up to 14.78 for cough; advanced age also proved to be an independent risk factor (OR 3.35-4.97). In conclusion, although the prevalence of NA was previously overestimated, our results indicate its importance, particularly among elderly patients who are exposed to a prominent risk of underdiagnosis and undertreatment.

Spontaneous gastroesophageal reflux and airway patency during the night in adult asthmatics.

Controversies still exist on the role of nighttime gastroesophageal reflux (GER) in precipitating nocturnal asthma. We tested the relationship between GER and nocturnal bronchoconstriction by continuously and simultaneously monitoring both respiratory resistances and esophageal pH in seven asthmatics with moderate to severe GER disease. Twenty-nine GER episodes were found during the study night lasting more than 5 min (LGER) and 72 not longer than 5 min (SGER). Both long (LGER) and short (SGER) gastroesophageal refluxes were able to maintain significantly higher lower respiratory resistances (RLR) at the resolution of each GER episode (RLR(e)) with respect to baseline values. RLR, expressed as the area under the RLR curve along each GER episode (AUCR(LR)) and as RLR(e), showed significant correlations with GER duration. Moreover, a significant correlation was found between RLR measured 10 min after GER resolution and GER duration during each episode. We conclude that GER itself is able to elicit nocturnal bronchoconstriction in asthmatics with moderate to severe GER disease and that bronchoconstriction severity and duration are related to GER duration.

Respiratory energetics during exercise at high altitude.

The purpose of this study was to assess the effect of high altitude (HA) on work of breathing and external work capacity. On the basis of simultaneous records of esophageal pressure and lung volume, the mechanical power of breathing (Wrs) was measured in four normal subjects during exercise at sea level (SL) and after a 1-mo sojourn at 5,050 m. Maximal exercise ventilation (VEmax) and maximal Wrs were higher at HA than at SL (mean 185 vs. 101 l/min and 129 vs. 40 cal/min, respectively), whereas maximal O2 uptake averaged 2.07 and 3.03 l/min, respectively. In three subjects, the relationship of Wrs to minute ventilation (VE) was the same at SL and HA, whereas, in one individual, Wrs for any given VE was consistently lower at HA. Assuming a mechanical efficiency (E) of 5%, the O2 cost of breathing at HA and SL should amount to 26 and 5.5% of maximal O2 uptake, whereas for E of 20% the corresponding values were 6.5 and 1.4%, respectively. Thus, at HA, Wrs may substantially limit external work unless E is high. Although at SL VEmax did not exceed the critical VE, at which any increase in VE is not useful in terms of body energetics even for E of 5%, at HA VEmax exceeded critical VE even for E of 20%.

Effect of age upon airway obstruction and reversibility in adult patients with asthma.

OBJECTIVE: In a cross-sectional study we evaluated the effect of aging (separately from that of duration of disease) on airway obstruction and reversibility by comparing two groups of non-smoker patients with asthma. METHODS: We compared two groups of patients: group A, which had 50 subjects (8 men and 42 women) aged 59.7+/-4.6 years (mean +/- SD), and group B, comprised of 51 subjects (19 men and 32 women) who were 35.7+/-7.4 years old. The groups were selected because of comparable baseline degree of obstruction (FEV1 % of predicted, 67.8+/-20.3 in group A; 73.0+/-19.6 in group B, NS) and duration of the disease (14.0+/-11.7 years vs 11.2+/-9.1, NS). Spirometric examination, with a bronchodilator test, was performed and subjects not reaching 85% of predicted were submitted to a 4-week course of inhaled steroids. RESULTS: Although a higher number of subjects from group B responded to the acute bronchodilator test (p < 0.001), the maximum response achievable with treatment (steroid or bronchodilator) (deltaFEV1 expressed as the percent of predicted) was not statistically different between groups (12.0+/-17.5 vs 16.0+/-23.9). The mean FEV1 attainable after treatment (deltaFEV1%PT) was significantly lower in the older group (p = 0.0006). Within groups, the baseline FEV1% did not correlate with age; it was inversely correlated with the duration of the disease (p < 0.03 and p < 0.01, respectively). In both groups deltaFEV1 was inversely related with the baseline FEV1, whereas FEV1%PT was correlated with the duration of the disease, with a slope nearly doubled in group B (p < 0.001). CONCLUSIONS: Both the process of aging and the prolonged exposure to disease effects are important factors in determining the functional characteristics of chronic asthma: In particular, aging is associated not only with a reduced acute responsiveness to bronchodilators, but also with a reduced slope of the duration-FEV1%PT relationship that suggests a slowing of the rate of loss of reversibility of uncertain biological meaning.

Effect of ageing on peak expiratory flow variability and nocturnal exacerbations in bronchial asthma.

The aim of this study was to evaluate the role of ageing on variability of airflow obstruction and on the specific pattern of nocturnal exacerbations ("morning dipping" of peak expiratory flow (PEF)) in asthma. Two groups of stable asthmatics (Group A: 23 patients, aged 14-47 yrs; Group B: 20 patients, aged 53-74 yrs), that were similar for duration of disease, degree of obstruction and response to bronchodilators, were studied. PEF was monitored four times daily for 2 weeks, and amplitude of variation and "morning dip" were calculated. Both PEF amplitude and "morning dip" were greater in the older patients (p<0.005). Amplitude was negatively correlated with baseline forced expiratory volume in one second (FEV1) in both groups (p<0.01); multiple correlation with age, duration of disease, baseline FEV1 and degree of reversibility was significant in the older group only. Morning dip was inversely correlated to baseline FEV1 (p<0.01) and reversibility (p<0.05). Nocturnal symptoms were reported by all of the five Group A "dippers", but by only 6 of the 13 Group B "dippers" (p<0.04). Ageing contributes to increased variability of airway calibre in asthma. Aged patients are potentially at risk because functional evidence of nocturnal asthma may frequently be accompanied by a poor subjective awareness. Therefore, a more extensive practice of PEF monitoring is recommended in aged asthmatics.

Evaluation of diaphragmatic fatigue in obstructive sleep apnoeas during non-REM sleep.

BACKGROUND: Resistive load applied to the airways may induce diaphragmatic fatigue, and hypoxaemia has been shown to predispose to the development of fatigue. Inspiratory muscle fatigue may occur in patients with obstructive sleep apnoea syndrome (OSAS), as these patients repetitively develop both inspiratory loading and hypoxaemia. The results of previous studies on this topic are inconclusive, probably because of the methodological approaches used. METHODS: Six obese patients with OSAS underwent a polysomnographic study. The diaphragmatic pressure time index (PTI) was evaluated as an indicator of diaphragmatic contraction, and the mean frequency of the diaphragmatic electromyogram power spectrum (Fm) and the maximum relaxation rate of transdiaphragmatic pressure (MRR) as indices of a fatiguing diaphragm. A total of 119 randomly selected apnoeas (each including 5-13 occluded efforts) were analysed throughout the night in non-REM sleep to assess possible muscle fatigue due to the high pressure generation in each apnoea. A breath-by-breath within-apnoea analysis was performed on the first three pre-apnoeic breaths, on all the occluded efforts, and on the first three unoccluded breaths following the apnoea interruption. Possible fatigue development due to the cumulative effect of apnoeas over the night was also evaluated. RESULTS: A progressive increase of Fm and MRR was found during the obstructive phase in all the subjects in the within-apnoea analysis. The overnight analysis did not show a reduction in either PTI, Fm, or MRR secondary to recurrent upper airway obstruction during the night. CONCLUSIONS: No evidence of diaphragmatic fatigue or impaired diaphragmatic contraction was found either within each apnoea or throughout the whole night, despite the generation of high PTI values during the apnoeic occluded phases. It is concluded that diaphragmatic fatigue does not occur in OSAS during non-REM sleep.

Respiratory mechanics during exhaustive submaximal exercise at high altitude in healthy humans.

1. The present investigation was conducted to test the hypothesis that the respiratory system is stressed more during exhaustive exercise in chronic hypoxia than in normoxia. 2. Four healthy male subjects (aged 33-35 years) exercised on a cycle ergometer at 75% of the local maximum oxygen consumption (Vo2,max) until exhaustion, at sea level (SL) and after a 1 month stay at 5050 m (HA). 3. Airflow at the mouth (V), oesophageal (Po) and gastric (Pg) pressures were measured at rest, during exercise and recovery. Minute ventilation (VE), respiratory power (Wresp), respiratory frequency (f) and transdiaphragmatic pressure (Pdi) were calculated from the measured variables. 4. The subjects' mechanical power output of cycling at HA was 23.7% lower than at SL. In spite of this reduction, time to exhaustion at HA was 55.3% less than at SL. VE increased slightly during exercise at SL, but showed a marked increase at HA, and at the end of exercise at HA was 47.3% higher than at SL. 5. Respiratory power increased more at HA than at SL (77.3% higher at the end of exercise) due to the increase in f needed to sustain the high VE. 6. Gastric pressure swings were negative at the end of HA exercise but always positive at SL. The Pai:Po ratio reached values below 1 at HA but never at SL. 7. These data seem to indicate that the respiratory system is stressed more during submaximal exercise at HA than at SL. We suggest that the exceedingly high VE demand, requiring an excessive Wresp, may lead to fatigue of the diaphragm.