AB0731 Thyroid disorders assessment: an unmet need in patients with idiopathic inflammatory myopathies?

Background

Thyroid diseases (TD) might compromise health status of patients, in particular owing to their possible impact on cardiovascular risk, bone mineral density (BMD) and muscle function. The prevalences of Hashimoto thyroiditis (HT), multinodular goiter (MNG) and Graves’ disease (GD) in general population correspond respectively to about 12%, 10% and 1.3%; it is well known HT represents a risk factor for the development of thyroid papillary cancer (TPC). Idiopathic inflammatory myopathies (IIMs) are rare systemic autoimmune disorders, with a pleiotropic clinical picture. TD are a known comorbidity of patients with connective tissue diseases; in particular, they might increase the risk of osteoporosis (OP) and fragility fractures (FF) in patients with SLE1. A recent study described the association between IIMs and both hyper- and hypo-thyroidism2.

Objectives

To evaluate the prevalence of TD in a monocentric cohort of patients with IIMs, exploring possible correlations with serology, organ involvement and comorbidities.

Methods

We retrospectively analyzed medical records of consecutive patients diagnosed with IIM according the EULAR/ACR 2017 criteria and regularly followed at our specialistic outpatient Myositis Clinic from January 2018 to December 2021. We collected data about demography, subset and duration of disease, organ involvement, serology, thyroid dysfunction and other comorbidities. As TD, we took into account the occurrence of HT, MNG and GD. Intergroups comparisons were assessed by using Chi-square, t-test and ANOVA. P values <0.05 were considered significant.

Results

The clinical charts of 151 patients were examined: 101 (66,9%) were female, the mean age was 65,1±14,0 years and the mean disease duration was 8,5±6,5 years. Clinical diagnosis were the following: 69 (45.7%) polymyositis, 59 (39.1%) dermatomyositis, 11 (7.3%) clinically amyopathic dermatomyositis, 10 (6.6%) inclusion body myositis, 2 (1.3%) juvenile dermatomyositis. Seventy-five patients (49.7%) had a TD; in particular, 39/151 (25.8%) had MNG, 34/151 (22.6%) had HT and 2/151 (1.3%) GD. The presence of a TD was significantly related with esophagus’ involvement (p=0.037), Raynaud’s phenomenon (RP) (p=0.045), sicca syndrome (SiS) (p<0,001), OP (p<0,001) and cataract (p=0,017). In particular, HT and MNG occurrence was respectively associated with a higher risk of OP (p<0,001) and of sicca syndrome (p<0,001). Interestingly, TD were significantly less frequent in patients with anti-Mi2beta autoantibodies (p=0,003) and anti-Jo1 autoantibodies (p=0,026). No further significant correlations emerged.

Conclusion

Our study showed nearly half of our IIMs patients had a TD, with a prevalence of both MNG and HT significantly higher than in general population; besides, owing to the retrospective nature of our study, these data could be underestimated. In addition to correlating with RP and SiS, TD showed a significant association with esophagus involvement; this result should be confirmed and clarified with future analyses. Moreover, in our cohort, TD were confirmed as a risk factor for a compromised BMD; in particular, HT was significantly associated with the occurrence of OP. Further studies are needed to corroborated our data in other cohorts of IIM patients and to explore if TD represent a risk factor for FF also in IIM; finally, since HT is a risk factor for TPC, an evaluation of its occurrence in our cohort should be designed. However, our data seem sufficient to underline the need to regularly screen IIM patients for thyroid function, aiming at optimizing their quality of care, both for activity and damage domains of their autoimmune disease.

References

[1]Carli L, et al. Risk factors for osteoporosis and fragility fractures in patients with systemic lupus erythematosus. Lupus Sci Med. 2016 Jan 19;3(1):e000098.

[2]Watad A, et al. Dysthyroidism in dermato/polymyositis patients: A case-control study. Eur J Clin Invest. 2021;51:e13460.

Disclosure of Interests

None declared

AB1152 COVID-19 mRNA VACCINE BOOSTER IN PATIENTS WITH SYSTEMIC AUTOIMMUNE DISEASES

Background

Patients with systemic autoimmune diseases (SADs) are often treated with drugs that interfere with the immune system and previous data showed a reduced seroconversion rate after anti-SARS-CoV2 vaccine in these subjects compared to healthy controls1. Administration of a booster dose of the vaccine could be particularly important in these patients, but data available to date are still scarce.

Objectives

To evaluate the antibody response to the booster dose of mRNA SARS-CoV2 vaccine in patients with SADs and to compare it to the response after completion of the first vaccination course. Secondly, to find possible correlations between a low antibody titre and patients’ clinical features, with special regard to ongoing immunosuppressive therapies.

Methods

Consecutive patients with an established diagnosis of SADs undergoing SARS-CoV2 vaccine were prospectively enrolled from January 2021; among them, we selected the patients who received the third vaccination dose between September and December 2021. Demographic and clinical data were collected at enrolment (sex, age, diagnosis, disease duration, ongoing therapies, previous SARS-CoV2 infection, presence of hypogammaglobulinemia); the last three elements were reassessed at each follow-up visit. Blood samples were collected 4 weeks both after the second (W4a) and the third (W4b) dose of the vaccine; a minority of patients was also tested 12 weeks after the second dose (W12). IgG antibodies to SARS-CoV2 receptor-binding domain (RBD) and neutralizing antibodies inhibiting the interaction between RBD and angiotensin converting enzyme 2 were evaluated. IgG anti-RBD were detected by solid phase assay on plates coated with recombinant RBD, while neutralising antibodies by using the kit SPIA (Spike Protein Inhibition Assay). Cut-off values were defined as the 97.5th percentile of a pre-vaccine healthy population. Statistical analysis was performed using IBM SPSS Statistics 20 and GraphPad Prism statistical packages. P values <0.05 were considered significant.

Results

Forty-five patients (95.6% female; mean age ±SD 55.6±14.1 years; mean disease duration 12.9±10.6 years) were enrolled. Diagnosis was in most cases connective tissue disease (31/45, 68.9%), followed by inflammatory arthritis (11/45, 24.4%) and systemic vasculitis (3/45, 6.7%). Two patients (4.4%) had a previous SARS-CoV2 infection and three had hypogammaglobulinemia (6.7%). At the time of the second dose, 18/45 patients were treated with glucocorticoids (GCs) [mean daily 6-methylprednisolone (6MP) dose 3.9 mg (min. 2, max. 14)], 17/45 with conventional synthetic disease-modifying anti-rheumatic drugs (csDMARDs) and 12/45 with biologic DMARDs (bDMARDs). At the third dose administration, 19/45 patients were treated with GCs [mean daily 6MP dose 4.1 mg (min. 1.5, max. 10)], 18/45 with csDMARDs and 13/45 with bDMARDs. Anti-RBD IgG were positive in 42/45 patients (93.3%) at W4a, in 16/18 (88.9%) at W12 and in 42/45 (93.3%) at W4b. Neutralizing antibodies were present in 38/45 patients (84.4%) at W4a, in 14/18 (77.8%) at W12 and in 42/45 (93.3%) at W4b. Both anti-RBD IgG titers and neutralizing antibody titers significantly increased after the third dose if compared to W4a (p<0.0001 both) (Figure 1). Interestingly, of the 7 patients who had not developed an adequate neutralizing antibody response after the first vaccination course, 5 mounted an adequate titer after the booster. Two non-responder patients were both on combination therapy (one with low dose of GCs plus mycophenolate mofetil, the other with methotrexate and infliximab).

Conclusion

Our data suggest that in patients with SADs there is a decline in the antibody titers developed after COVID-19 vaccination, however the booster dose is effective in restoring an adequate antibody titre. These data consolidate the importance of a booster dose of COVID-19 vaccination in patients with SADs to aid in the generation of an immune response.

References

[1]Jena A et al. Response to SARS-CoV-2 vaccination in immune mediated inflammatory diseases: systematic review and meta-analysis. Autoimmun Rev. 2022

Acknowledgements

The authors would like to thank all the patients who participated in the study and the nurses Sabrina Gori, Rosanna Lo Coco, Lucia Pedrocco, Carla Puccini, Pasqualina Semeraro, Manuela Terachi, Maria Tristano, Valentina Venturini and Catiuscia Zoina who took care of the patients.

Disclosure of Interests

None declared

POS0922 RECOMBINANT HUMAN HYALURONIDASE-FACILITATED SUBCUTANEOUS IMMUNOGLOBULIN FOR IDIOPATHIC INFLAMMATORY MYOSITIS: A MULTICENTER OBSERVATIONAL STUDY

Background

The spectrum of idiopathic inflammatory myositis (IIM) includes a heterogeneous group of diseases characterized by chronic inflammation of skeletal muscle, often associated with skin, joints, lungs, esophageal, gastrointestinal and cardiac involvement. Conventional treatment for IIM is based on glucocorticoids and immunosuppressants. Moreover, intravenous immunoglobulin (IVIg) has emerged as a promising steroid- and DMARD-sparing treatment for myositis [1]. However, the long-term use of IVIg is complicated by the fact that the intravenous route requires in-hospital drug administration, which not only influences patients’ quality of life, but is also associated with an increased risk of systemic adverse effects, difficulties in venous access over time, and high costs [2]. On these bases, administration of subcutaneous Ig (SCIg) by a programmable pump has been considered as a possible alternative to IVIg.

Recombinant human hyaluronidase-facilitated (hf)-SCIg is currently approved for the use in patients with primary immunodeficiency disorders, while its efficacy and safety in myositis disorders is limited [3].

Objectives

This multicenter retrospective observational study is sought to evaluate the effectiveness and safety of recombinant human hf-SCIg in patients with IIM treated at different referral centers.

Methods

A multicenter, retrospective, cohort study was conducted on adult patients diagnosed with IIM according to the EULAR/ACR classification criteria [4] treated with recombinant human hf-SCIg according to routine clinical practice. The effectiveness of this treatment was assessed in terms of variations in the Medical Research Council (MRC) score, creatine kinase values, inflammatory parameters, and daily prednisolone dosage. Safety data were also collected.

Results

Twenty-three patients with IIM treated with hf-SCIg were included (16/23 females, 70%; median age at diagnosis of 61 years (IQR 43-65)).

In most patients (22/23, 96%), IIM had been initially treated with high-dose corticosteroids (+/- synthetic or biologic DMARDs), and 20/23 patients (87%) had received previous IVIg treatment (in 12 for remission induction and in 8 for maintenance).

Hf-SCIg were introduced after a median time of 2 years (1-4) from the diagnosis of IIM, mostly for remission maintenance (18/23). Hf-SCIg was started in combination with oral corticosteroids in 19/23 [83%, at a median dose of 5 mg/day (4-12.5)] and/or with traditional or biologic DMARDs (18/23, 78%).

At time of hf-SCIg introduction, the median MRC score was 4 (3-4) and the median creatine kinase level was of 134 U/L (44-243). After 6 months of treatment, the median MRC score was 4 (3-5); no patient discontinued hf-SCIg, and only one experience a mild adverse event.

Conclusion

Hf-SCIg seems effective to maintain remission in a high proportion of IIM patients, while showing a good safety profile in the first 6 months of treatment.

References

[1]Oddis. Treatment in myositis. Nat Rev Rheumatol 2018

[2]Danieli. Subcutaneous IgG in the Myositis Spectrum Disorders. Curr Rheumatol Rev. 2018.

[3]Wasserman. Recombinant human hyaluronidase-facilitated subcutaneous infusion of human immunoglobulins for primary immunodeficiency. JACI.2012.

[4]Lundberg. 2017 European League Against Rheumatism/American College of Rheumatology classification criteria for adult and juvenile idiopathic inflammatory myopathies and their major subgroups. ARD. 2017

Table 1.

Effectiveness and safety of hf-ScIG treatment in a cohort of patients with IIM

hf-ScIg beginning3 months6 monthsN patients with available follow-up data2320 *19*MRC score §4 (3-4)4 (4-5)4 (3-5)Creatine kinase, U/L §134 (44-243)118 (77-308)130 (84-222)ESR, mm/h §21 (15-28)30 (25-43)31 (23-39)CRP, mg/dl §0.2 (0.1-0.5)0.3 (0.1-0.5)0.3 (0.1-0.3)Prednisolone dosage, mg/day §5 (4-12.5)7.5 (5-10)5 (5-7.5)Adverse events-NA1 **

*none discontinued

**One infusion site reaction

§ median value (IQR)

CRP=C reactive protein; ESR=erythrocyte sedimentation rate

Disclosure of Interests

None declared

POS0910 PSYCHIATRIC COMORBIDITIES ASSESSMENT: AN UNMET NEED IN PATIENTS WITH IDIOPATHIC INFLAMMATORY MYOPATHIES?

Background

Idiopathic Inflammatory Myopathies (IIMs) are rare and complex chronic diseases, with a strong impact on patients’ Quality of Life (QoL) in terms of both physical and emotional functioning. Despite its key role in daily life, patients’ emotional status could be difficult to be investigated by physicians. As known, patients with chronic conditions are at higher risk of anxiety and depression, but data about their prevalence in IIMs are still limited. The Hospital Anxiety and Depression Scale (HADS) is a validated questionnaire to evaluate the presence and severity of both anxiety (HADS-A) and depression (HADS-D) in patients.

Objectives

To determine the prevalence of anxiety and depression in a monocentric cohort of IIMs patients and to evaluate possible correlations with clinical features, disease activity and parameters of QoL.

Methods

Consecutive adult patients with a diagnosis of IIM (2017 EULAR/ACR criteria) were recruited during a scheduled follow-up visit. Demographic and clinical features were recorded (sex, age, disease subset and duration, organ involvement, comorbidities). IIM disease activity was evaluated following International Myositis Assessment & Clinical Studies Group Disease Activity Core Set Measures. To detect anxiety and depression status, HADS was administered to patients, who were also asked to fill in Short-Form 36 Items Health Survey (SF-36). For both HADS-A and -D subscales, patients were classified as at risk for scores ≥8 (borderline for scores 8-10, high risk if ≥11). Results were reported as mean±SD for continuous variables and as percentage for categorical variables. Intergroup comparisons were assessed by using Chi-square, t-test and ANOVA. Pearson coefficient was used to analyse the correlations between variables. P values <0.05 were considered significant.

Results

Fifty-three patients (72% female; mean age 64.8±12.0 years; mean disease duration 7.4±6.2 years) were enrolled. Twenty (37.7%) showed increased anxiety scores (mean 11.35, min. 8 – max. 17): 10 (50%) borderline and 10 (50%) high risk. Twenty (37.7%) had an increased depression score (mean 11.75, min. 8 – max. 19): 6 (30%) borderline and 14 (70%) high risk. If abnormal scores of both HADS-A and -D were found in 15 patients (28.3%), 17 patients (32.1%) were at high risk of at least one of the conditions. Sex, age, disease subset and duration did not seem to influence patients’ emotional status. Apart from an association between Raynaud’s Phenomenon occurrence and higher HADS-A scores (p=0.045), no significant correlations with organ involvements emerged. A strong association was found between fibromyalgia and higher HADS-A and -D scores (p=0.006 both). Patients with elevated anxiety levels presented significantly higher scores of Patient Global Assessment (PGA, p=0.002) and Health Assessment Questionnaire (HAQ, p=0.007) and significantly lower scores of Manual Muscle Testing (MMT8, p=0.004). HADS-D scores were similarly associated with PGA (p=0.001), HAQ (p<0.0001) and MMT8 (p=0.001). The presence of anxiety and depression was associated with lower scores in all SF-36 domains (all p≤0.016 for HADS-A and all p≤0.006 for HADS-D). Moreover, a correlation was found among SF-36 scores and PGA (all r <-0.516, p<0.01), HAQ (all r <-0.541, p<0.01) and MMT8 values (all r >0.299, p<0.05).

Conclusion

These results show nearly 40% of our cohort was at risk of anxiety or depression; almost 30% were at risk of developing both conditions together and quite one third was at high risk to develop at least one of them. As expected, these conditions were favoured from a concomitant fibromyalgia. Moreover, a compromised QoL and a functional limitation, as evaluated by PGA, HAQ and MMT8, in agreement with SF-36 domains, were significant risk factors for their occurrence. Therefore, our data, although preliminary, underline the need of a more comprehensive evaluation of IIMs patients, who should be screened for psychiatric comorbidities and, in case of high risk, referred to a specialist evaluation, in the perspective of improving their quality of care.

Disclosure of Interests

None declared

POS1232 LONG-TERM OUTCOMES OF COVID-19 VACCINATION IN PATIENTS WITH RARE AND COMPLEX CONNECTIVE TISSUE DISEASES: AN AD-INTERIM ANALYSIS OF ERN-ReCONNET VACCINATE STUDY

Background

Since the COVID-19 vaccination campaign was launched all over Europe, there has been general agreement on how benefits of SARS-CoV2 vaccines outweigh the risks in patients with rare connective tissue diseases (rCTDs). Yet, there is still limited evidence regarding safety and efficacy of such vaccines in these patients, especially in the long-term. For this reason, in the framework of ERN-ReCONNET, an observational long-term study (VACCINATE) was designed in order to explore the long-term outcome of COVID-19 vaccination in rCTDs patients. The consent form was developed thanks to the involvement of the ERN ReCONNET ePAG Advocates (European Patients Advocacy Group).

Objectives

To evaluate the safety profile of COVID-19 vaccination in rCTDs patients and the potential impact on disease activity. Primary endpoints were the prevalence of adverse events (AEs) and of disease exacerbations post-vaccination. Secondary endpoints were the proportion of serious adverse events (SAEs) and adverse events of special interest for COVID-19 (adapted from https://brightoncollaboration.us/wp-content/uploads/2021/01/SO2_D2.1.2_V1.2_COVID-19_AESI-update-23Dec2020-review_final.pdf)

Methods

The first ad-interim analysis of the VACCINATE study involved 9 ERN-ReCONNET Network centres. Patients over 18 years of age with a known rCTD and who received vaccine against COVID-19 were eligible for recruitment. Demographic data and diagnoses were collected at the time of enrolment, while the appearance of AEs and potential disease exacerbations were monitored after one week from each vaccination dose, and then after 4, 12 and 24 weeks from the second dose. A disease exacerbation was defined as at least one of the following: new manifestations attributable to disease activity, hospitalization, increase in PGA from previous evaluation, addition of corticosteroids or immunosuppressants.

Results

A cohort of 300 patients (261 females, mean age 52, range 18-85) was recruited. Systemic lupus erythematosus (44%) and systemic sclerosis (16%) were the most frequent diagnoses, followed by Sjogren’s syndrome (SS,12%), idiopathic inflammatory myositis (IMM,10%), undifferentiated connective tissue disease (UCTD,8%), mixed connective tissue disease (MCTD,4%), Ehlers-Danlos’s syndrome (EDS,4%), antiphospholipid syndrome (APS,2%). AEs appearing 7 days after the first and second doses were reported in 93 (31%) and 96 (32%) patients respectively, mainly represented by fatigue, injection site reaction, headache, fever and myalgia. Otitis, urticaria, Herpes Simplex-related rash, stomatitis, migraine with aura, vertigo, tinnitus and sleepiness were reported with very low frequency. Less than 2% of patients experienced AEs within 24 weeks from the second dose. No SAEs or AEs of special interest were observed in the study period. There were 25 disease exacerbations (8%), 7 of which severe. The highest number of exacerbations was observed after 4 weeks from the second dose (12 within week 4, 6 within week 12 and 7 within week 24). Disease exacerbation was most frequent in patients with EDS (33%) and MCTD (25%).

Conclusion

This preliminary analysis shows that COVID-19 vaccination is safe in rCTDs patients. AEs appear most often early after vaccination and are usually mild. Disease exacerbations are not frequent, but can be potentially severe and tend to occur most frequently within the first month after vaccination. Exacerbations can also occur 3-6 months after vaccination, although a causal relationship with the vaccination remains to be established. Our present data underline the importance of long-term observational studies.

Table 1.

AEs and disease exacerbations per disease

DiagnosisPatients enrolled (%) (n=300)EAs after 1st and 2nd dose (%)Exacerbations (%)APS25714EDS45033IIM10527MCTD44225SS12598SLE44698SSC16492UCTD850-

Acknowledgements

VACCINATE is a study promoted by the European Reference Network on rare and complex connective tissue diseases, ERN ReCONNET. This publication was funded by the European Union’s Health Programme (2014-2020)

Disclosure of Interests

None declared

POS0909 THE ROLE OF IMACS CORE SET MEASURES TO ROUTINELY EVALUATE THE QUALITY OF LIFE OF IDIOPATHIC INFLAMMATORY MYOPATHIES PATIENTS IN CLINICAL PRACTICE

Background

Idiopathic Inflammatory Myopathies (IIMs) are rare, multisystemic and complex diseases, often impacting on patients’ quality of life (QoL). Patient Reported Outcomes (PROs) assess the overall health status of patients, particularly for emotional and functional domains. In clinical practice the administration of PROs might have some limitations, because they tend to be time-consuming and sometimes difficult to be filled in by patients. The International Myositis Assessment & Clinical Studies Group Disease Activity Core Set Measures (IMACS-CSM) are a tool created to specifically assess disease activity and QoL in IIMs.

Objectives

To evaluate the ability of IMACS-CSM in assessing IIMs patients’ QoL in comparison with both generic and IIMs specific PROs.

Methods

Consecutive adult patients with an established diagnosis of IIM (2017 EULAR/ACR criteria) followed at our Myositis Clinic were enrolled and evaluated during scheduled follow-up visits. Demographic and clinical data (age, sex, disease subset and duration, organ involvement) were collected. IMACS-CSM [Physician Global Activity (PhGA), Patient Global Activity (PGA), 8-items Manual Muscle Testing (MMT8), Health Assessment Questionnaire (HAQ), CPK values, Myositis Disease Activity Assessment Tool (MDAAT)] were used to evaluate both disease activity and QoL. Patients’ perspective was evaluated also by administration of PROs not included in the IMACS-CSM: Short-Form 36 Items Health Survey (SF-36), Functional Assessment of Chronic Illness Therapy Fatigue Subscale (FACIT-F), Myositis Activity Profile (MAP), MD Anderson Dysphagia Inventory (MDADI). Results were expressed as mean±SD for continuous variables and as percentage for categorical variables. Intergroup comparisons were assessed by using Chi-square, t-test and ANOVA. Pearson coefficient was used to analyse the correlations between IMACS-CSM variables and the other PROs. P values <0.05 were considered significant.

Results

Sixty patients (65% female, mean age 59.9±13.5 years, mean disease duration 7.7±6.1 years), 37 (61.7%) with polymyositis, 20 (33.3%) with dermatomyositis and 3 (5%) with inclusion body myositis, were enrolled. Among IMACS-CSM, the mean HAQ and PGA scores were significantly worse in case of muscle (p=0.017) and oesophageal involvement (p=0.017), respectively; as expected, MMT8 score was associated with muscle involvement (p=0.017); MDAAT score was instead associated with oesophageal dysfunction (p<0.001). No associations were found between IMACS-CSM and others clinical and demographic parameters. FACIT-F correlated positively with MMT8 (r 0.432, p=0.001) and negatively with PhGA, PGA, HAQ and MDAAT (all r <-0.404 and p≤0.002 except for PhGA with r=-0.338 and p=0.016). SF-36 domains correlated positively with MMT8 (all r >0.259, p≤0.05) and negatively with PGA (all r <-0.393, p≤0.001), HAQ (all r <-0.422, p≤0.001) and MDAAT (all r <-0.276, p≤0.05). Opposite correlations were found for MAP domains: MMT8 all r <-0.297, p≤0.05; PGA all r >0.326, p≤0.05; HAQ all r >0.483, p≤0.001; MDAAT all r >0.268, p≤0.05. Similarly, MDADI scores correlated negatively with MMT8 (r <-0.363, p=0.005) and positively with PGA, HAQ and MDAAT (all r >0.318, p≤0.015). Notably, no correlations emerged between these PROs and CPK values.

Conclusion

Even if IMACS-CSM offer a partial evaluation of patients’ perspective, our data show how not only HAQ and PGA, but also PhGA, MMT8 and MDAAT (expressing rheumatologist’s point of view) seem to adequately reflect overall health status of IIMs patients, thus giving to clinicians a reliable assessment of their QoL. Therefore, the core set should be routinely used in clinical practice during every outpatient visit, while more accurate and complex PROs might be administered at larger time intervals or during disease flares, to optimize IMACS-CSM’s analysis.

Disclosure of Interests

None declared

Physical and chemical characterization of representative samples of recycled rubber from end-of-life tires

A large number of end-of-life tires (ELTs) were sampled and classified by type, age and origin to obtain recycled rubber samples representative of the materials placed on the Italian market. The selected recycled tire rubber samples were physically and chemically characterized and a chemometric approach was used to determine correlations. The polycyclic aromatic hydrocarbons (PAHs) content was correlated to the aromaticity index and a model was built to establish the H-Bay aromaticity index (H-Bay) from the PAH concentrations. ELT of different origin and age produced in non-European countries generally had higher PAH content and a higher H-Bay index. H-Bay values of all the samples were lower than the REACH limits and old tires had higher aromatic content than recent ones, possibly due to the replacement of aromatic oils in tire production.

COMBINED NUMERICAL, FINITE ELEMENT AND EXPERIMENTAL-OPTIMIZATION APPROACH IN THE PRODUCTION PROCESS OF MEDIUM-VOLTAGE, RUBBER-INSULATED ELECTRIC CABLES VULCANIZED WITH STEAM WATER. PART 1: DSC AND RHEOMETER EXPERIMENTAL RESULTS

The standard industrial process to produce medium-voltage electric cables based on EPDM consists of cross-linking by peroxides with high-temperature steam (pressurized water vapor). Suboptimal material cross-linking is usually due to a decrease of the temperature along the vulcanization pipe. Temperature variations are connected to variations in steam pressure into pipe system. A combined numerical and experimental approach to optimize the production process of medium-voltage, rubber-insulated electric cables vulcanized with steam water is presented. The numerical part of this process is based on the use of finite elements and an optimization genetic algorithm (GA) and will be presented in Part 2. In Part 1, attention focuses on the experimental investigation. In particular, the final cross-linking degree is experimentally obtained by means of differential scanning calorimetry (DSC) determination of nondecomposed peroxide from the external layer to the core of the cable insulation. The final task is to minimize the difference between numerically predicted and experimentally determined cross-linking degree using a steam-temperature profile along the pipe to explain the variations. A preliminary evaluation of kinetic-reaction constants of rubber cured with peroxides is provided with the support of a comprehensive experimental investigation of the curing process by means of standard rheometer characterizations done at different curing temperatures. An existing mathematical, kinetic model is applied to the experimentally determined rheometer curves, allowing the determination of partial-reaction kinetic constants used in the finite-element computations.

Breathing and propelling in crawl as a function of skill and swim velocity

This study analyzes apnea (A), exhalation (E), and inhalation (I) duration with respect to stroke organization in front crawl as a function of inhalation side, swim velocity and performance level. Thirty-six male subjects comprised two groups based on performance level: more expert (ME) and less expert (LE) swimmers. All swam with one inhalation per cycle to the preferred side at speeds corresponding to two specific race paces: 100-m (V100) and 800-m (V800) velocities. The breathing arm (BA) is located on the inhalation side, and the non-breathing arm (NBA) on the opposite side. The sound of air passing in and out of the swimmers' mouths was captured by a microphone and synchronized with video frames. Stroke phases and arm coordination were identified by video analyses. Arm coordination was quantified using two indices of coordination (IdC) corresponding to the lag time between the beginning of the BA (IdC-BA) or NBA (IdC-NBA) propulsive action and the end of that of the other arm. As velocity increases, the ME are observed to reduce I during BA recovery (-19.4 +/- 31.6 %, p < 0.05) while the LE increase A (+ 34.8 +/- 25.2 %, p < 0.05) during BA entry, catch and recovery and NBA pull and push. These variations are related to a lengthening of the pull for both arms at the expense of BA non-propulsive phases. At V100, the ME have greater E (p < 0.05) during BA entry and catch (+ 21.1 +/- 38.2 %) and NBA push (+ 26.3 +/- 39.5 %) compared to the LE. This increase, at the expense of A, corresponds to a shorter BA push and NBA recovery. At V800, the ME exhibit a longer A (p < 0.05) during BA recovery (+ 19.9 +/- 33.2 %) and NBA pull (+ 24.2 +/- 31.5 %), and decreased I during NBA push and pull. These differences are related to a shortening of BA recovery and pull and a longer push for both arms. These breath and stroke adaptations correspond to an increase in stroke rate and IdC-BA with the velocity and performance level. This study points out the breathing-propelling aspects of coordination that indicate technical skill in swimming.

Analysis of breathing in the crawl as a function of skill and stroke characteristics

The purpose of this study was to measure and compare the durations of exhalation (DE), inhalation (DI), and inhalatory apnea (DAI) expressed as percentage of stroke-cycle duration using two groups (more expert and less expert) of 6 front crawl swimmers each at near 100-m speed (high speed) and 800-m speed (low speed). Two breathing conditions were considered, breathing to the preferred side with and without a nose-clip. The relationships between stroking characteristics (swimming speed, stroke rate, and stroke length) and the three durations of breathing were examined as a function of skill and swimming speed. The data show that use of a nose-clip does not significantly change those measures. At high speed, the more expert group had a lower inhalation and a higher exhalation than the less expert group. The stroke rate correlated with speed .92 (p<.01) and was mainly associated with inhalation (r=-.78, p<.01). Inclusion of exhalation as a second variable improved significantly (p<.01) the accuracy of the regression up to .97. At low speed, the less expert had lower inhalatory apnea than the more expert. Stroke length correlated with speed .86 (p<.01) and was mainly associated with inhalatory apnea (r=.70, p<.05). At high speed, the more expert had a lower inhalation than at low speed, while durations of exhalation and inhalatory apnea did not vary significantly. On the contrary, the less expert had a lower exhalation and a higher inhalatory apnea, while duration of inhalation remained relatively unchanged. The present study shows that these durations and their relations to stroking characteristics could be considered significant indicators of skill in swimming.