Reactive molecular dynamics simulations of lithium-ion battery electrolyte degradation

The development of reliable computational methods for novel battery materials has become essential due to the recently intensified research efforts on more sustainable energy storage materials. Here, we use a recently developed framework allowing to consistently incorporate quantum-mechanical activation barriers to classical molecular dynamics simulations to study the reductive solvent decomposition and formation of the solid electrolyte interphase for a graphite/carbonate electrolyte interface. We focus on deriving condensed-phase effective rates based on the elementary gas-phase reduction and decomposition energy barriers. After a short initial transient limited by the elementary barriers, we observe that the effective rate shows a transition to a kinetically slow regime influenced by the changing coordination environment and the ionic fluxes between the bulk electrolyte and the interface. We also discuss the impact of the decomposition on the ionic mobility. Thus, our work shows how elementary first-principles properties can be mechanistically leveraged to provide fundamental insights into electrochemical stability of battery electrolytes.

AB0186 AT WHAT LEVEL SHOULD WE MEASURE INTIMA-MEDIA THICKNESS IN RHEUMATOID ARTHRITIS?

Background:

Rheumatoid arthritis (RA) is chronic inflammatory rheumatism characterized by an independent cardiovascular (CV) risk. The screening of carotid intima-media thickness (IMT) in the common carotid artery appears to be a marker of atherosclerosis and is used as a specific tool for CV risk assessment.

Objectives:

The main of this study was to determine the most associated US sites with CV risk in RA.

Methods:

The present study is a prospective study conducted on Tunisian RA patients in rheumatology department of Mohamed Kassab University Hospital (March and December 2020). The characteristics of the patients and those of the disease were collected. The measurement of cIMTwas done using high-resolution B-mode carotid US with a Philips machine with the patient in supine position, according to AmericanSociety of Echocardiography guidelines.The carotid bulb below itsbifurcation and the internal and external carotid arteries were evaluated bilaterally with gray scale, spectral and color Doppler ultra-sonography using proprietary software for carotid arterymeasurements.IMT was measured using the two inner layers of the commoncarotid artery and an increased IMT was defined as ≥0.9 mm. The CV risk at 10 years was calculated by the SCORE index.

Results:

Forty-seven patients were collected, of which 78.7% were women. The mean age was 52.5 ±11.06 years. The rheumatoid factor (RF) was positive in 57.8% of cases, and anti-citrullinated peptide antibodies (ACPA) were positive in 62.2% of cases. RA was erosive in 81.6% of cases. Hypertension (hypertension) was present in 14.9% of patients and diabetes in 12.8% of patients. Nine patients were active smokers. The mean IMT in the left common carotid (LCC) was 0.069 ±0.015, in the left internal carotid (LIC) was 0.069 ±0.015, in the left external carotid (LEC) was 0.060 ±0.023. The mean IMT was 0.068 ±0.01 in the right common carotid (RCC), 0.062 ±0.02 in the right internal carotid (RIC), and 0.060 ±0.016 in the right external carotid (REC). The mean SCORE index of CV risk was 2±2.81 [0-11.6]. CV risk was significantly associated with the IMTs for LIC (p=0.029; r=0.374), LEC (p=0.04; r=0.480), and REC (p=0.016; r=0.408). No association was found between the IMT in the LCC (p=0,361; r=0,162), neither in the RCC (p=0,438; r=0,140) nor the RIC (p=0,670; r=0,077).

Conclusion:

In our study, IMT is strongly associated with score index, especially in carotid bifurcation. However, IMT measured in common carotid does not reflect a cardiovascular risk at 10-years.

References:

[1]S. Gunter and al. Arterial wave reflection and subclinical atherosclerosis in rheumatoid arthritis. Clinical and Experimental Rheumatology 2018; 36: Clinical E.xperimental.

[2]Aslan and al. Assessment of local carotid stiffness in seronegative and seropositive rheumatoid arthritis. SCANDINAVIAN CARDIOVASCULAR JOURNAL, 2017.

[3]Martin I. Wah-Suarez and al, Carotid ultrasound findings in rheumatoid arthritis and control subjects: A case-control study. Int J Rheum Dis. 2018;1–7.

Disclosure of Interests:

None declared

AB0191 ON WHICH FACTOR TO ACT TO REDUCE CARDIOVASCULAR RISK IN PATIENTS WITH RHEUMATOID ARTHRITIS?

Background:

Patients with rheumatoid arthritis (RA) are at higher cardiovascular risk (CVR) than the general population due to chronic inflammation. Several factors, both modifiable and non-modifiable, can increase this risk. Intima-media thickness (IMT) was considered as a marker for atherosclerosis.

Objectives:

This study aimed to identify predictor factors of increasing IMT.

Methods:

The prospective study was carried out on patients with RA who met the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria. These patients were followed in the rheumatology department of the Kassab Institute. The socio-demographic data, biological and immunological parameters were collected.

Framingham’s score quantified the cardiovascular risk at 10-years. Carotid Ultrasonography (US) using a high resolution B mode carotid measured intima-media thickness (IMT) as a subclinical marker of atherosclerosis. Carotid US was performed in the supine position, according to American Society of Echocardiography guidelines. IMT was measured in the left (LCC) and right (RCC) common carotid arteries, the left (LIC) and right (RIC) internal carotid arteries, and the left (LEC) and right (RIC) internal carotid arteries. An increased IMT was defined as ≥0.9 mm.

We analyzed data by the SPSS statistical package. A p-value <0.05 was considered significant.

Results:

Of the 47 patients surveyed, 78.7% were female. The mean age was 52.5 ±11.06 [32-76]. The duration disease was 86.25 ±63 months [5-288] and was erosive in 81.6% of cases. The rheumatoid factor (RF) was positive in 57.8% of patients, and citrullinated antipeptide antibodies (ACPA) were present in 62.2%. Eight patients had a previous CV history (hypertension, diabetes or dyslipidemia) and 16.4% were active smokers. Among women, 43.6% were postmenopausal. ITM was significantly higher in men at LIC (0.037) and LEC (0.025). Older age was associated with increased ITM in LIC (p=0.046; r=0.295), LEC (p=0.05; r=0.412), RCC (p=0.034; r=0.317), and REC (p=0.009; r=0.382). The ITM for LCC, LIC, LEC, RCC, RIC, and REC was higher in postmenopausal women, with no significant difference (p=0.782, p=0.208, p=0.877, r=0.734, p=0.808, p=0.437, respectively).

Among the modifiable factors, active smoking was associated with a higher ITM at the REC level (p=0.047). However, weight was not associated with an increased ITM (LCC: p=0.092; LIC: p=0.985; LEC: p=0.952; RCC: p=0.744; RIC: p=0.210; REC: p=0.510). In our study, there was no significant association between DAS28 disease activity or inflammatory marks and ITM (LCC: p=0.784; LIC: p=0.316; LEC: p=0.420; RCC: p=0.784; RIC: p=0.484; REC: p=0.754).

Conclusion:

In our study, the non-modifiable factors associated with increased ITM were advanced age and male gender. The modifiable factor impacting ITM was primarily active smoking. Surprisingly, disease activity and biological inflammation did not influence ITM.

References:

[1]S. Gunter and al. Arterial wave reflection and subclinical atherosclerosis in rheumatoid arthritis. Clinical and experimental rheumatology 2018; 36: clinical e.xperimental.

[2]Aslan and al. Assessment of local carotid stiffness in seronegative and seropositive rheumatoid Arthritis. Scandinavian cardiovascular journal, 2017.

[3]Martin i. Wah-suarez and al, carotid ultrasound findings in rheumatoid arthritis and control subjects: a case-control study. Int j rheum dis. 2018;1–7.

Disclosure of Interests:

None declared

POS0586 RHEUMATOID ARTHRITIS IS AN INFLAMMATORY DISEASE WITH A HIGH CARDIOVASCULAR RISK

Background:

Hypertension, diabetes, and dyslipidemia are traditional risk factors of cardiac events. Carotid ultrasonography is an available way to detect subclinical atherosclerosis.

Objectives:

This study aimed to compare the intima-media thickness in RA patients based on their personal cardiovascular (CV) history of hypertension (hypertension), diabetes, and dyslipidemia.

Methods:

The present study is a prospective study conducted on Tunisian RA patients in the rheumatology department of Mohamed Kassab University Hospital (March and December 2020). The characteristics of the patients and those of the disease were collected.

The high-resolution B-mode carotid US measured the IMT, according to American Society of Echocardiography guidelines. The carotid bulb below its bifurcation and the internal and external carotid arteries were evaluated bilaterally with grayscale, spectral, and color Doppler ultrasonography using proprietary software for carotid artery measurements. IMT was measured using the two inner layers of the common carotid artery, and an increased IMT was defined as ≥0.9 mm. A Framingham score was calculated to predict the cardiovascular risk at 10-year.

Results:

Forty-seven patients were collected, 78.7% of whom were women. The mean age was 52.5 ±11.06 [32-76]. The rheumatoid factor (RF) was positive in 57.8% of cases, and anti-citrullinated peptide antibodies (ACPA) were positive in 62.2% of cases. RA was erosive in 81.6% of cases. Hypertension (hypertension) was present in 14.9% of patients, diabetes in 12.8% of patients, and dyslipidemia in 12.8% of patients. Nine patients were active smokers. The mean IMT in the left common carotid (LCC) was 0.069 ±0.015, in the left internal carotid (LIC) was 0.069 ±0.015, in the left external carotid (LEC) was 0.060 ±0.023. The mean IMT was 0.068 ±0.01 in the right common carotid (RCC), 0.062 ±0.02 in the right internal carotid (RIC), and 0.060 ±0.016 in the right external carotid (REC). The IMT was significantly higher in the left common carotid (LCC) in patients with hypertension (p=0.025). There was no significant difference in the other ultrasound sites (LIC, LEC, RCC, RIC, and REC) according to the presence or absence of hypertension. The IMT was also significantly increased in patients with diabetes at LCC (p=0.017) and RIC (p=0.025). There was no significant difference in the IMT at different ultrasound sites between patients with and without dyslipidemia.

Conclusion:

Hypertension was significantly associated with the increase in IMT at the LCC level in RA patients. Diabetes had an impact on IMT in LCC and RIC. However, dyslipidemia did not affect the IMT at the different ultrasound sites.

References:

[1]S. Gunter and al. Arterial wave reflection and subclinical atherosclerosis in rheumatoid arthritis. Clinical and Experimental Rheumatology 2018; 36: Clinical E.xperimental.

[2]Aslan and al. Assessment of local carotid stiffness in seronegative and seropositive rheumatoid arthritis. SCANDINAVIAN CARDIOVASCULAR JOURNAL, 2017.

[3]Martin I. Wah-Suarez and al, Carotid ultrasound findings in rheumatoid arthritis and control subjects: A case-control study. Int J Rheum Dis. 2018;1–7.

[4]Gobbic C and al. Marcadores subclínicos de aterosclerosis y factores de riesgo cardiovascular en artritis temprana. Subclinical markers of atherosclerosis and cardiovascular risk factors in early arthritis marcadores subclínicos de aterosclerose e fatores de risco cardiovascular na artrite precoce.

Disclosure of Interests:

None declared

AB0189 LIPOPROTEIN ABNORMALITIES IN RHEUMATOID ARTHRITIS PATIENTS

Background:

The lipid paradox is termed the decreased cholesterol level in rheumatoid arthritis (RA). Nevertheless, the apolipoprotein levels are usually higher than a healthy person and are predictors of cardiovascular events.

Objectives:

We aimed to describe lipid abnormalities in RA patients and to look for predictor factors of these changes.

Methods:

The prospective study was carried out on patients with RA who met the 2010 American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification criteria. These patients were followed in the rheumatology department of the Kassab Institute.

We collected the socio-demographic data, biological and immunological parameters.

The lipid assessment included: a measurement of total cholesterol (TC), HDL, LDL, and triglycerides (TG). Lipoproteins APOA1 and APOB were measured. All data were collected after patient consent.

Results:

Of the 47 patients recruited, 78.7% were female. The mean age was 52.5 ±11.06 [32-76]. The average RA progressed from 86.25 ±63 months [5-288] and was erosive in 81.6% of cases. The rheumatoid factor (RF) was positive in 57.8% of patients, and citrullinated antipeptide antibodies (ACPA) were present in 62.2%. Eight patients had a previous CV history.

Mean TC was 4.42 ±1.3 [1.2-7.58], mean HDL was 1.38 ±0.73 [0.18-4.10], mean LDL was 2.55 ±1.16 [0.24-5.54]. The mean TG value was 1.28 ±0.6 [0.24-5.54]. TC elevation was found in 9.1% of cases, HDL in 21.3% of cases, LDL in 5.5% of cases, and TG in 16.4% of cases. Mean APOB/APOA1 ratio was 0.67 ±0.18 [0,46-1,11]. LDL elevation was associated to a high DAS28 (p=0.06, r=0.512). APOA1 was associated to a low DAS28 (p=0.04, r=-0.642).

The mean value of APO A1 was 1.36 ±0.21 [0.84-1.81], that of APOB was 0.90 ±0.22 [0.58-1.40]. APOA1 values were lower in patients with high-level LDL (p=0.767). The APOB value was associated with lipid disturbance without significant correlation (p=0.291).

Conclusion:

Lipid test abnormalities can be found in RA patients outside of any known CV risk factors. APOA1 seems to have a protective effect. Screening and treatment of these abnormalities can prevent CV risk.

References:

[1]Miguel Bernardes and al. Coronary artery calcium score in female rheumatoid arthritis patients: Associations with apolipoproteins and disease biomarkers. Int J Rheum Dis. 2019;00:1–16.

[2]Anna So dergren and al. Biomarkers associated with cardiovascular disease in patients with early rheumatoid arthritis. PLOS ONE. August 5, 2019.

Disclosure of Interests:

None declared

POS0587 EFFECT OF RHEUMATOID ARTHRITIS TREATMENTS ON THE INTIMA-MEDIA THICKNESS OF SUPRA-AORTIC TRUNKS AND ON CARDIOVASCULAR RISK

Background:

Patients with rheumatoid arthritis (RA) are exposed to a multifactorial cardiovascular risk: chronic inflammation, endogenous and exogenous factors, and treatment.

Objectives:

The aim of this study was to investigate the impact of RA treatments on cardiovascular risk and the influence of supra aortic trunks.

Methods:

This is a prospective study conducted on RA patients followed-up between March and December 2020 at the rheumatology department of the Mohamed Kassab Institute of Orthopedics and Traumatology. Socio-demographic data of patients and characteristics of the disease were collected. The disease activity was evaluated by the Disease Activity Score 28. Prescribed treatments were specified. Ultrasonography of the supra aortic trunks was performed by measuring, in centimeters, the Intima-media Thickness (IMT) at the level of the left (LCC) and right (RCC) common carotid arteries, the left (LIC) and right (RIC) internal carotid arteries and the left (LEC) and right (REC) internal carotid arteries.

Results:

Of the 47 patients surveyed, 78.7% were female. The mean age was 52.5 ±11.06 [32-76]. The average RA progressed from 86.25 ±63 [5-288] and was erosive in 81.6% of cases. The rheumatoid factor (RF) was positive in 57.8% of patients, and citrullinated antipeptide antibodies (ACPA) were present in 62.2%. The treatments taken were: Methotrexate (MTX) (54.5%), Sulfasalazine (SLZ) (1.8%), Leflunomide (LFN) (3.6%), a combination of cs-DMARDs (5.5%), and biotherapy (10.9%). The prescribed biotherapies were: Etanercept (3.6%), Adalimumab (1.8%), Certolizumab (1.8%), Infliximab (3.6%). Corticosteroids (CT) were prescribed in 38.2% of patients, non-steroidal anti-inflammatory drugs (NSAIDs) (3.6%), and analgesics (41.8%).

CT had a protective effect on IMT in LIC (p=0.031) and RIC (p=0.016). MTX had a significant protective effect on IMT in RIC (p=0.002) and LEC (p=0.033).

SLZ was associated with an increase in IMT at the RIC level (p=0.05). There was no association between NSAID use and IMT. MTX and CT were significantly associated with a decrease in SCORE (p=0.02; p=0.05, respectively). There was a non-significant association between SLZ or LFN and decreased SCORE (p=0.140, p=0,970).

Conclusion:

In our series, patients taking MTX and CT had a lower IMT than those not taking these drugs. SLZ was associated with an increase in IMT. NSAIDs did not affect IMT in our study.

References:

[1]Pasquale Ambrosino and al, Subclinical atherosclerosis in patients with rheumatoid arthritis A meta-analysis of literature studies. Thrombosis and Haemostasis 113.5/2015

[2]Hyun-Je Kim and al, Effects of Methotrexate on Carotid Intima-media Thickness in Patients with Rheumatoid Arthritis. The Korean Academy of Medical Sciences 2015.

Disclosure of Interests:

None declared

Treatment of chickpea with Rhizobium isolates enhances the expression of phenylpropanoid defense-related genes in response to infection by Fusarium oxysporum f. sp. ciceris

Differential expression of phenylalanine ammonia-lyase (PAL), chalcone synthase (CHS) and isoflavone reductase (IFR) genes involved in phenylpropanoids metabolism was investigated using Northern blot analyses in chickpea seedlings bacterized with Rhizobium isolates (PchDMS and Pch43) and further challenged with Fusarium oxysporum f. sp. ciceris (Foc) race 0. Gene activation patterns in the moderately resistant accession INRAT87/1 were compared with those exhibited by the susceptible accession ILC482 at various time intervals after inoculation with Foc, to determine whether differences in levels or timing of transcript accumulation could be correlated with differences in the susceptibility of chickpea accessions to Foc. Gene activation was higher in the moderately resistant accession INRAT87/1 than in the susceptible ILC482. Pre-treatment of chickpea seedlings with Rhizobium isolates before inoculation with the pathogen enhanced the accumulation of the three genes' mRNA transcripts. In parallel, changes in the soluble phenolic pool produced through pathways involving these enzymes were analyzed in chickpea roots. A strong accumulation of these compounds was revealed at 72 hpi in both accessions. After that time, these high levels of phenolic compounds were maintained until the end of the experiment in the moderately resistant accession, while they have significantly declined in the susceptible accession. HPLC analyses revealed a very high accumulation of the constitutive isoflavones, formononetin and biochanin A and their glycoside conjugates in chickpea roots inoculated with Rhizobium isolates and/or challenged with Foc, as compared to the controls. Our results suggest that the increased accumulation of phenolic compounds, observed in chickpea seedlings inoculated with Foc, can be attributed to increased expression of genes in the phenylpropanoid pathway and that such gene expression is enhanced by pre-treatment with Rhizobium isolates.

Transcriptional photoregulation of cell-type-preferred expression of maize rbcS-m3: 3' and 5' sequences are involved

In the C4 plant maize, members of the rbcS gene family, encoding the small subunit of ribulose-1,5-bisphosphate carboxylase/oxygenase, are not expressed in mesophyll cells (MC) but are expressed strongly in the adjacent bundle sheath cells (BSC). Expression of genes in an in situ transient expression assay indicates that the photostimulated expression seen in BSC during the first 24 h that leaves of dark-grown seedlings are illuminated requires rbcS-m3 sequences lying between -211 bp and +434 bp of the transcription start site. Photoregulated partial suppression of rbcS-m3 expression in MC, on the other hand, requires gene sequences that lie between -907 bp and -445 bp together with sequences that lie between +720 and +957 bp within the 3' transcribed region of the gene. Suppression in MC occurs during the second 24-h period that dark-grown seedlings have been illuminated, but not during the first 24 h. The 3' +720- to +957-bp region is also effective in lowering MC expression when it is relocated to a position > 2 kbp upstream of the transcription start site. Thus, suppression of rbcS-m3 expression in MC has, at the least, a substantial transcriptional component. As reported earlier, a converse pattern of suppression in BSC and stimulation of expression in MC is seen in the control of cab-m1 in maize leaves.