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2.
Nanomaterials (Basel) ; 13(23)2023 Nov 27.
Article in English | MEDLINE | ID: mdl-38063727

ABSTRACT

This research article explores the effect of grain boundary (GB) misorientation on the mechanical behavior of aluminum (Al) bicrystals by means of molecular dynamics (MD) simulations. The effect of GB misorientation on the mechanical properties, fracture resistance, and crack propagation are evaluated under monotonic and cyclic load conditions. The J-integral and the crack tip opening displacement (CTOD) are assessed to establish the effect of the GB misorientation angle on the fracture resistance. The simulations reveal that the misorientation angle plays a significant role in the mechanical response of Al bicrystals. The results also evidence a gradual change in the mechanical behavior from brittle to ductile as the misorientation angle is increased.

3.
Europace ; 25(Supp 1): i1248-i1248, June 6, 2023. tab
Article in English | CONASS, Sec. Est. Saúde SP, SESSP-IDPCPROD, Sec. Est. Saúde SP | ID: biblio-1435881

ABSTRACT

INTRODUCTION: Rassi score (NYHA functional class III/IV HF [5 points], cardiomegaly [5 points], contractions abnormalities [3 points], non-sustained ventricular tachycardia [3 points], low amplitude QRS [2 points] and male sex [2 points]) is used in the clinic for risk stratification due to cardiovascular death in patients with Chagas disease (P-CD). Whether this score has any role in identifying patients at risk of complex ventricular arrhythmias has not been determined. OBJECTIVE: Assess whether there is an association between Rassi score and the presence of potentially malignant complex ventricular arrhythmias in P-CD. METHODS: 79 P-CD (34 men, age 61±11 years-old), consecutively referred for 24h-Holter were divided into 2 groups: low risk Rassi score (57 P, 0-6 points) and medium-high risk (22 P, 7-20 points). The amount and complexity of ventricular arrhythmia (> 30/ h, ventricular tachycardia [VT]), LVEF, heart rate turbulence (HRT) indexes (turbulence onset [TO] and turbulence slope [TS]) and HRT category (0 [without disautonomy], 1 and/or 2 [presence of disautonomy]) were evaluated. RESULTS: Compared to P-CD with low risk score, those with medium-high risk had more ventricular arrhythmias, lower LVEF, worse HRT indexes and more HRT categories 1 and/or 2 (see table below). CONCLUSIONS: 1) P-CD and Rassi score of medium to high risk have a greater amount of ventricular arrhythmias; 2) These findings can be explained by the presence of greater degree of disautonomy, assessed by HRT, and by the lower LVEF; 3) Prospective studies are necessary to confirm these findings in clinical practice.


Subject(s)
Arrhythmias, Cardiac , Chagas Disease
4.
Article in English | MEDLINE | ID: mdl-37145102

ABSTRACT

The increase of revision surgeries in hip replacement procedure in Colombian young adult population can be addressed by a new design of femoral stem that reduces stress shielding. A new femoral stem was designed using topology optimization as a design aid to reduce the mass in the femoral stem and its overall stiffness, combined with the theoretical, computational, and experimental assessment of the new design that complies with a static and fatigue safety factor greater than one. The new femoral stem design can be used as a design tool to reduce the number of revision surgeries caused by stress shielding.

5.
Ann Biomed Eng ; 51(9): 2070-2085, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37227601

ABSTRACT

Commotio cordis is one of the leading causes of sudden cardiac death in youth baseball. Currently, there are chest protector regulations regarding the prevention of Commotio cordis in baseball and lacrosse; however, they are not fully optimized. For the advancement of Commotio cordis safety, it is vital to include various age groups and a variety of impact angles in the testing process. This study employed finite element models and simulated Commotio cordis-inducing baseball collisions for different velocities, impact angles, and age groups. Commotio cordis risk response was characterized in terms of left ventricular strain and pressure, chest band and rib deformation, and force from impact. Normalized rib and chest band deformation when correlated with left ventricular strain resulted in R2 = 0.72, and R2 = 0.76, while left ventricular pressure resulted in R2 = 0.77, R2 = 0.68 across all velocities and impact angles in the child models. By contrast, the resultant reaction force risk metric as used by the National Operating Committee on Standards for Athletic Equipment (NOCSAE) demonstrated a correlation of R2 = 0.20 in the child models to ventricular strain, while illustrating a correlation to pressure of R2 = 0.74. When exploring future revisions to Commotio cordis safety requirements, the inclusion of deformation-related risk metrics at the level of the left ventricle should be considered.


Subject(s)
Commotio Cordis , Wounds, Nonpenetrating , Child , Adolescent , Humans , Commotio Cordis/prevention & control , Commotio Cordis/complications , Ventricular Fibrillation , Death, Sudden, Cardiac/etiology , Death, Sudden, Cardiac/prevention & control , Protective Devices , Sports Equipment
6.
CJC Open ; 5(4): 268-284, 2023 Apr.
Article in English | MEDLINE | ID: mdl-37124966

ABSTRACT

Inherited arrhythmia syndromes are rare genetic conditions that predispose seemingly healthy individuals to sudden cardiac arrest and death. The Hearts in Rhythm Organization is a multidisciplinary Canadian network of clinicians, researchers, patients, and families that aims to improve care for patients and families with inherited cardiac conditions, focused on those that confer predisposition to arrhythmia and sudden cardiac arrest and/or death. The field is rapidly evolving as research discoveries increase. A streamlined, practical guide for providers to diagnose and follow pediatric and adult patients with inherited cardiac conditions represents a useful tool to improve health system utilization, clinical management, and research related to these conditions. This review provides consensus care pathways for 7 conditions, including the 4 most common inherited cardiac conditions that confer predisposition to arrhythmia, with scenarios to guide investigation, diagnosis, risk stratification, and management. These conditions include Brugada syndrome, long QT syndrome, arrhythmogenic right ventricular cardiomyopathy and related arrhythmogenic cardiomyopathies, and catecholaminergic polymorphic ventricular tachycardia. In addition, an approach to investigating and managing sudden cardiac arrest, sudden unexpected death, and first-degree family members of affected individuals is provided. Referral to specialized cardiogenetic clinics should be considered in most cases. The intention of this review is to offer a framework for the process of care that is useful for both experts and nonexperts, and related allied disciplines such as hospital management, diagnostic services, coroners, and pathologists, in order to provide high-quality, multidisciplinary, standardized care.


Les syndromes d'arythmie héréditaires sont des troubles génétiques rares qui prédisposent des personnes en apparence en bonne santé à un arrêt cardiaque soudain et à la mort. L'organisation Hearts in Rhythm Organization est un réseau multidisciplinaire canadien qui regroupe des cliniciens, des chercheurs ainsi que des patients et leurs proches dans le but d'améliorer les soins prodigués aux patients atteints de maladies cardiaques héréditaires et à leur famille, en particulier dans le cas des maladies qui entraînent une prédisposition à l'arythmie et à un arrêt cardiaque soudain et/ou à la mort. Puisque ce champ de recherche évolue rapidement, la mise au point d'un guide pratique et simple à l'intention des professionnels de la santé pour le diagnostic et le suivi des patients enfants et adultes présentant une maladie cardiaque héréditaire serait donc un outil intéressant pour améliorer l'utilisation du système de santé et la prise en charge clinique de ces maladies tout en orientant la recherche à ce propos. La présente synthèse expose les trajectoires de soins faisant l'objet d'un consensus pour sept maladies, dont les quatre maladies cardiaques héréditaires les plus courantes qui prédisposent à l'arythmie. Elle présente aussi des scénarios pour orienter les examens, le diagnostic, la stratification du risque et la prise en charge des patients. Ces maladies sont le syndrome de Brugada, le syndrome du QT long, la cardiomyopathie arythmogénique du ventricule droit et les cardiomyopathies arythmogènes associées, et la tachycardie ventriculaire polymorphe catécholaminergique. En outre, une approche pour la prise en charge de l'arrêt cardiaque soudain, de mort subite inattendue et des membres de la famille immédiate de la personne touchée est proposée. L'orientation vers des cliniques spécialisées en cardiogénétique doit être envisagée dans la plupart des cas. L'objectif est d'établir un cadre de soins qui soit utile pour les experts et les non-experts ainsi que pour les professionnels des domaines connexes, par exemple le personnel de l'administration hospitalière et des services diagnostiques, les coroners et les pathologistes, en vue d'offrir des soins multidisciplinaires normalisés de grande qualité.

7.
Can J Cardiol ; 38(8): 1271-1276, 2022 08.
Article in English | MEDLINE | ID: mdl-35346798

ABSTRACT

BACKGROUND: Patients with hemodynamically tolerated ventricular tachycardia (VT) and minimally reduced left ventricular ejection fraction (LVEF) remain a group that presents a prognostic and therapeutic dilemma. METHODS: We studied patients from our implanted cardioverter-defibrillator (ICD) database who received ICDs for hemodynamically tolerated VT and mildly reduced LVEF (36%-49%) at time of implant between May 2015 and December 2019. Time to appropriate ICD therapy was assessed. Clinical features associated with recurrent VT/ventricular fibrillation (VF) with ICD therapies were explored using binary logistic regression. RESULTS: Among 2037 ICDs placed between May 2015 and December 2019, 64 subjects met the inclusion criteria. The mean age of the study group was 68 ± 12 years, and 58 (90.6%) subjects were male. Average ejection fraction was 40% ± 4.4 (range 36%-49%). Twenty-two (34%) subjects received antitachycardia pacing (ATP) for VT at 229 ± 265 days after ICD placement. Fifteen (23%) subjects received appropriate ICD shocks 305 ± 321 days after implant. The rate of recurrent VT/VF among the 37 patients with ICD therapy was 195 ± 39 beats per minute (bpm). This was significantly more rapid than initial presenting VT rates before ICD placement (183 ± 27 bpm) (P = 0.048). Multivariate analysis showed no factors independently associated with recurrent VT/VF. CONCLUSIONS: Patients with mildly impaired LV function and hemodynamically tolerated VT receive appropriate ICD therapies over the 3 years following implant. This patient group warrants further investigation, as their recurrent VT/VF rates can be much more rapid, and 23% go on to receive appropriate ICD shocks.


Subject(s)
Defibrillators, Implantable , Tachycardia, Ventricular , Aged , Aged, 80 and over , Arrhythmias, Cardiac , Electric Countershock , Female , Humans , Male , Middle Aged , Stroke Volume , Tachycardia, Ventricular/etiology , Tachycardia, Ventricular/therapy , Ventricular Fibrillation/therapy , Ventricular Function, Left
8.
Clin Res Cardiol ; 111(6): 680-691, 2022 Jun.
Article in English | MEDLINE | ID: mdl-34999932

ABSTRACT

BACKGROUND: A high proportion of patients undergoing catheter ablation (CA) for atrial fibrillation (AF) experience recurrence of arrhythmia. This meta-analysis aims to identify pre-ablation serum biomarker(s) associated with arrhythmia recurrence to improve patient selection before CA. METHODS: A systematic approach following PRISMA reporting guidelines was utilised in libraries (Pubmed/Medline, Embase, Web of Science, Scopus) and supplemented by scanning through bibliographies of articles. Biomarker levels were compared using a random-effects model and presented as odds ratio (OR). Heterogeneity was examined by meta-regression and subgroup analysis. RESULTS: In total, 73 studies were identified after inclusion and exclusion criteria were applied. Nine out of 22 biomarkers showed association with recurrence of AF after CA. High levels of N-Terminal-pro-B-type-Natriuretic Peptide [OR (95% CI), 3.11 (1.80-5.36)], B-type Natriuretic Peptide [BNP, 2.91 (1.74-4.88)], high-sensitivity C-Reactive Protein [2.04 (1.28-3.23)], Carboxy-terminal telopeptide of collagen type I [1.89 (1.16-3.08)] and Interleukin-6 [1.83 (1.18-2.84)] were strongly associated with identifying patients with AF recurrence. Meta-regression highlighted that AF type had a significant impact on BNP levels (heterogeneity R2 = 55%). Subgroup analysis showed that high BNP levels were more strongly associated with AF recurrence in paroxysmal AF (PAF) cohorts compared to the addition of non-PAF patients. Egger's test ruled out the presence of publication bias from small-study effects. CONCLUSION: Ranking biomarkers based on the strength of association with outcome provides each biomarker relative capacity to predict AF recurrence. This will provide randomised controlled trials, a guide to choosing a priori tool for identifying patients likely to revert to AF, which are required to substantiate these findings.


Subject(s)
Atrial Fibrillation , Catheter Ablation , Atrial Fibrillation/diagnosis , Atrial Fibrillation/surgery , Biomarkers , C-Reactive Protein , Humans , Recurrence , Treatment Outcome
9.
J Biomech Eng ; 144(5)2022 05 01.
Article in English | MEDLINE | ID: mdl-34729591

ABSTRACT

Commotio cordis is the second leading cause of sudden cardiac death in young athletes. Currently available chest protectors on the market are ineffective in preventing cases of commotio cordis in young athletes who play baseball. This study focused on using contour maps to identify specific baseball impact locations to the chest that may result in instances of commotio cordis to children during baseball games. By identifying these vulnerable locations, we may design and develop chest protectors that can provide maximum protection to prevent commotio cordis in young athletes. Simulation cases were run using the validated CHARM-10 chest model, a detailed finite element model representing an average 10-year-old child's chest. A baseball model was developed in company with the chest model, and then used to impact the chest at different locations. A 7 × 8 impact location matrix was designed with 56 unique baseball impact simulations. Left ventricle strain and pressure, reaction force between the baseball and chest, and rib deformations were analyzed. Left ventricle strain was highest from baseball impacts directly over the left ventricle (0.34) as well as impacts slightly lateral and superior to the cardiac silhouette (0.34). Left ventricle pressure was highest with impacts directly over the left ventricle (82.94 kPa). We have identified the most dangerous impact locations resulting in high left ventricle strain and pressure. This novel study provided evidence of where to emphasize protective materials for establishing effective chest protectors that will minimize instances of commotio cordis in young athletes.


Subject(s)
Athletic Injuries , Baseball , Commotio Cordis , Athletic Injuries/complications , Athletic Injuries/prevention & control , Child , Commotio Cordis/complications , Death, Sudden, Cardiac/epidemiology , Death, Sudden, Cardiac/etiology , Death, Sudden, Cardiac/prevention & control , Humans , Ventricular Fibrillation/complications , Ventricular Fibrillation/prevention & control
10.
Comput Methods Biomech Biomed Engin ; 25(3): 247-256, 2022 Feb.
Article in English | MEDLINE | ID: mdl-34320889

ABSTRACT

Commotio cordis is a sudden death mechanism that occurs when the heart is impacted during the repolarization phase of the cardiac cycle. This study aimed to investigate commotio cordis injury metrics by correlating chest force and rib deformation to left ventricle strain and pressure. We simulated 128 chest impacts using a simulation matrix which included two initial velocities, 16 impact locations spread across the transverse and sagittal plane, and four baseball stiffness levels. Results showed that an initial velocity of 17.88 m/s and an impact location over the left ventricle was the most damaging setting across all possible settings, causing the most considerable left ventricle strain and pressure increases. The impact force metric did not correlate with left ventricle strain and pressure, while rib deformations located over the left ventricle were strongly correlated to left ventricle strain and pressure. These results lead us to the recommendation of exploring new injury metrics such as the rib deformations we have highlighted for future commotio cordis safety regulations.


Subject(s)
Athletic Injuries , Baseball , Commotio Cordis , Wounds, Nonpenetrating , Baseball/injuries , Benchmarking , Commotio Cordis/complications , Heart Ventricles , Humans , Ribs , Ventricular Fibrillation/etiology
11.
Nanomaterials (Basel) ; 11(11)2021 Oct 21.
Article in English | MEDLINE | ID: mdl-34835548

ABSTRACT

Molecular dynamics simulations of cracked nanocrystals of aluminum were performed in order to investigate the crack length and grain boundary effects. Atomistic models of single-crystals and bi-crystals were built considering 11 different crack lengths. Novel approaches based on fracture mechanics concepts were proposed to predict the crack length effect on single-crystals and bi-crystals. The results showed that the effect of the grain boundary on the fracture resistance was beneficial increasing the fracture toughness almost four times for bi-crystals.

12.
Eur Heart J Case Rep ; 5(11): ytab401, 2021 Nov.
Article in English | MEDLINE | ID: mdl-34755031

ABSTRACT

BACKGROUND: Ictal bradyarrhythmia is a rare condition defined by temporal lobe epilepsy resulting in bradycardia or asystole and can result in syncope. This needs to be differentiated from isolated syncope in patients with seizure disorder, as treatment strategies differ. CASE SUMMARY: A 50-year-old female with well-controlled temporal epilepsy and a 20-year seizure-free period presented to her neurologist with abrupt onset of sudden drop attacks thought to be ictal events with potential underlying ictal bradyarrhythmia and was initially treated with escalation of anticonvulsant therapy. However, her workup was consistent with a diagnosis of cardiac syncope. She subsequently underwent successful insertion of a pacemaker, with no recurrence of her presenting episodes at a 13-month follow-up. DISCUSSION: Ictal syncope and isolated syncope may share a common terminal pathway and may have similar presenting symptoms. In patients with known seizure disorder, loss of consciousness may be attributable to epileptic events, ictal syncope, or isolated syncope-which can be difficult to differentiate. This case highlights the ambiguous nature of such episodes and the importance of simultaneous electroencephalogram/electrocardiogram monitoring, as this can have implications on treatment.

13.
Mymensingh Med J ; 30(4): 1067-1072, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34605478

ABSTRACT

The timing of milestone is influenced by many factors. Sex and socioeconomic status has significant effect to some psycomotor milestones. The study was conducted to determine the pattern of milestones of development of infants in our country and to compare it in different sex and socioeconomic condition. It was a hospital based prospective study done in Sir Sallimullah Medical College and Mitford Hospital, Dhaka, Bangladesh from October 2014 to November 2015. Healthy term newborn infants with average birth weight were included in this study and milestones of this birth cohort were assessed monthly from birth to 12 months of age by using a set of 60 milestones. Total number of 217 babies was enrolled but during follow up 0.9% developed meningitis, 43.7% was lost to follow up and 55.2% of the cohort was followed up to 12 months of age. Among 120 babies 51.7% were male, 48.3% were female babies and 51.7% belong to lower, 32.5% middle and 15.8% upper socioeconomic group. There was no significant difference between male and female infants achieving most of the milestones of development except in language development in which female infants were little bit higher than male infants.


Subject(s)
Hospitals , Social Class , Bangladesh/epidemiology , Birth Weight , Female , Humans , Infant , Infant, Newborn , Male , Prospective Studies
15.
Eur Heart J Case Rep ; 5(3): ytab096, 2021 Mar.
Article in English | MEDLINE | ID: mdl-33768197

ABSTRACT

BACKGROUND: Modern permanent pacemakers (PPMs) have individual features designed to identify cardiac rhythm abnormalities and improve their performance. Inappropriate pacing inhibition may be an undesired outcome from these features and cause symptoms in patients who require frequent pacing, leading to dizziness, and syncope. Inappropriate inhibition can be difficult to identify in circumstances that are intermittent and difficult to reproduce. CASE SUMMARY: A 57-year-old female underwent a mitral valve replacement (MVR) for severe mitral stenosis. One month following MVR, she presented with symptomatic third-degree atrioventricular block, and a dual-chamber PPM (Advisa™, Medtronic, Minneapolis, USA) was implanted and programmed DDD 50-130 b.p.m. At the 3-month follow-up, she reported frequent episodes of lightheadedness. She was found to have intermittent ventricular pacing inhibition on a 48-h Holter monitor due to an internal function of the Advisa™ series of PPMs that attempts to store an electrogram (EGM) every 1 h and 30 s. During the EGM storage, an amplified signal from the storage capacitor can result in oversensing by the ventricular channel and inappropriate pacing inhibition. DISCUSSION: To rectify the issue, the ventricular lead sensitivity value was increased from 0.9 mV to 1.2 mV. No instances of inappropriate ventricular pacing inhibition were noted on follow-up. To our knowledge, this is a rare case of inappropriate ventricular pacing inhibition caused by a combination of PPM self-adjusting sensitivity algorithm and oversensing every 1 h and 30 s from an amplified storage capacitor. Physicians should be aware of this possible complication and differentiate it from device or lead malfunction.

16.
CJC Open ; 3(12): 1490-1494, 2021 Dec.
Article in English | MEDLINE | ID: mdl-34993461

ABSTRACT

BACKGROUND: Cardiac implantable electronic devices deliver life-sustaining therapy and may be prone to hardware degeneration over time. Functioning transvenous endocardial leads with visible insulation breaks are amenable to lead revision (LRV) or lead repair (LRP), with medical adhesive. The latter is a less invasive and more cost-effective strategy. However, data are sparse on the overall safety of such an approach. METHODS: This is a retrospective cohort study of patients with lead insulation defects managed by either LRV or LRP with medical adhesive. The data analyzed were from January 2010 to January 2021. All-cause mortality, and both early and late complications, was ascertained for all cases. RESULTS: A total of 57 cases were identified, with a mean age (standard deviation) of 75 (±11.8) years; 18 (31.6%) were women. A total of 35 patients (62.5%) underwent LRV for an insulation defect, and 21 (37.5%) underwent LRP. There was no statistical difference in the rate of early and late complications between the 2 groups over a mean follow-up period of 1.15 (±0.78) years [3 (8%)] LRV vs 1 (5%) LRP, P = 0.88). One death was identified in each group, unrelated to either the device or a device-related procedure. There was no association between device type and the likelihood of LRP vs LRV as an attempted strategy (χ2 = 2.25, P = 0.53). CONCLUSIONS: The results of this study suggest that the use of a lead-repair strategy, with silicone adhesive glue and an anchoring sleeve, is not associated with an increased rate of early or late complications, compared with lead revision in the management of visible lead insulation defects with stable lead function.


INTRODUCTION: Les dispositifs cardiaques électroniques implantables offrent un traitement essentiel au maintien de la vie, mais peuvent subir une détérioration de leur matériel au fil du temps. Le fonctionnement des sondes endocavitaires transveineuses ayant des ruptures visibles de l'isolant se prête à la révision de sonde (RVS) ou à la réparation de sonde (RPS) au moyen d'un adhésif médical. Cette dernière stratégie est moins invasive et plus efficiente. Toutefois, les données sur l'innocuité générale d'une telle approche sont rares. MÉTHODES: Il s'agit d'une étude de cohorte rétrospective de patients dont les sondes montrent des défaillances de l'isolant prises en charge par RVS ou par RPS au moyen d'un adhésif médical. Les données analysées s'échelonnaient de janvier 2010 à janvier 2021. La mortalité toutes causes confondues ainsi que les complications précoces et tardives étaient établies pour tous les cas. RÉSULTATS: Nous avons trouvé un total de 57 cas, dont l'âge moyen (écart type) était de 75 (± 11,8) ans; 18 (31,6 %) étaient des femmes. Au total, 35 patients (62,5 %) avaient subi une RVS en raison d'une défaillance de l'isolant, et 21 (37,5 %) avaient subi une RPS. Il n'y avait aucune différence statistique dans le taux de complications précoces et tardives entre les deux groupes durant une période moyenne de suivi 1,15 (± 0,78) an [3 (8 %)] RVS vs un (5 %) RPS, P = 0,88. Dans chaque groupe, nous avons noté 1 décès non associé au dispositif ou à une intervention liée au dispositif. Il n'y avait aucune association entre le type de dispositif et la probabilité de tentative d'une stratégie de RPS vs d'une stratégie de RVS (χ2 = 2,25, P = 0,53). CONCLUSIONS: Les résultats de cette étude montrent que l'utilisation d'une stratégie de RPS au moyen d'un adhésif de silicone et d'une douille d'ancrage n'est pas associée à un taux plus élevé de complications précoces ou tardives que la RVS dans la prise en charge des défaillances visibles de l'isolant de la sonde lors de fonctionnement stable de la sonde.

17.
Heliyon ; 6(7): e04364, 2020 Jul.
Article in English | MEDLINE | ID: mdl-32695901

ABSTRACT

Chromium toxicity is considered as a major problem for agricultural soil that reduced crop productivity by affecting photosynthetic tissues. Exogenous application of melatonin can alleviate the adverse effects of chromium toxicity on plant growth. However, little is known about its effect on thylakoidal protein complexes responsible for conversion of solar energy to biochemical energy. Chlorophyll fluorescence a transients considered one of the best non-invasive and rapid method for the evaluation of photosynthetic (Photosystem II) efficiency of plants and plant health under environmental stress conditions. In the present study, three-week old plants of two canola cultivars AC-Excel and DGL were applied to melatonin (0, 1, 5, 10 µM) when grown under chromium stress (0, 50 and 100 µM) for further two weeks. Chromium stress reduced the growth (fresh and dry weights of shoots and roots) of both canola cultivars and exogenous application of 5 and 10 µM melatonin improved the growth of canola at 50 or 100 µM chromium stress. This improvement was greater in cv DGL than in AC-Excel. Increasing chromium decreased the photosynthetic pigments (chlorophyll a and chlorophyll b). However, 5 and 10 µM melatonin application improved chlorophyll a at 50 µM chromium stress. Structural stability and efficiency of photosystem II (PSII) measured as performance index (PIABS) and ratios of fluorescence (Fv/Fm, Fv/Fo) Fv decreased due to chromium stress. JIP-test parameters showed that chromium stress increased the absorption and trapping fluxes with decrease in electron transport fluxes which caused the damage to reaction centers (RC), detachment of oxygen evolving complex (OEC) from RC or inefficiency of electron transfer from OEC to RC. Such adverse effects were greater in cv AC-Excel. However exogenous application of melatonin improved PIABS, electron transport per reaction center (ET/RC), reduced variable fluorescence at J step (VJ) reflecting melatonin protected PSII from chromium stress induced damage by protecting OEC. Thus, OJIP fluorescence transients are quite helpful for understanding the intersystem electron transport beyond photosystem II in canola cultivars due to melatonin application under chromium stress. FINDINGS: Exogenous application of melatonin alleviated toxic effects of chromium on plant growth of canola by modulating photosynthesis, enhanced photosystem II efficiency and regulation of electron transport flux to protect photo-inhibition of PSII from oxidative damage.

18.
Pacing Clin Electrophysiol ; 43(12): 1599-1604, 2020 12.
Article in English | MEDLINE | ID: mdl-32597505

ABSTRACT

Cross-talk is a well-described phenomenon in a dual-chamber cardiovascular implantable electronic device. Far-field ventricular events are more commonly sensed in the atrial channel, the reverse is uncommon, and seeing both at the same time has never been reported. We present a case of double cross-talk in a dual-chamber Medtronic ® implantable cardioverter-defibrillator. In this report, we decipher an unusual device response to the cross-talk and describe the programming changes required to resolve it.


Subject(s)
Defibrillators, Implantable , Equipment Failure , Aged , Algorithms , Electrocardiography , Equipment Failure Analysis , Humans , Male
19.
Eur Heart J Case Rep ; 4(2): 1-5, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32352064

ABSTRACT

BACKGROUND: Capillary leak syndrome (CLS) is a rare connective tissue disease, triggered by the leak of serous fluid into the interstitial spaces, characterized by a hallmark of oedema and effusions in confined spaces. The limiting factor in CLS management appears to be its diagnosis rather than treatment, which is usually to contain the disease progression rather than a cure. CASE SUMMARY: We report a case of a 51-year-old woman with recurrent life-threatening presentations of pericardial effusions, pleural effusions, and generalized swelling of face and extremities. The only notable past medical history was of Type 1 diabetes. Numerous investigations did not lead to specific disease accounting for pericardial effusions and pleural effusions. Eventually, the diagnosis of CLS was made based on hypovolaemic shock, hypoalbuminaemia, and haemoconcentration without the presence of albuminuria. She was managed with steroids to reduce system inflammation and later with immunoglobulins and tumour necrosis factor to contain the disease process. Since her diagnosis and subsequent appropriate management, she has not had further admissions with cardiac tamponade 16 months of follow-up. DISCUSSION: The diagnosis of CLS is difficult to make unless there is a high degree of suspicion and until other causes have been ruled out. It remains a challenging condition to manage as the treatment options are limited and patients recurrently present with emergencies until the correct diagnosis is made and the optimal treatment is provided.

20.
Appl Ergon ; 83: 102983, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31731094

ABSTRACT

This study explores sex/gender-related differences in ergonomic exposures and musculoskeletal disorders for 4090 working Syrian refugee children (>8-≤18 years) in the Bekaa Valley, Lebanon (n = 2107 males; n = 1983 females). Data was collected on demographic, occupational, and socioeconomic indicators and musculoskeletal disorders. Results revealed that children engaged in strenuous work. Ergonomic exposures differed by sex/gender, with girls more likely to engage in repetitive movements and boys in heavy lifting. Girls bore a double burden of work inside and outside their households and were more prone to wrist and hand pain. More girls reported working under pressure to finish their job on time while more boys reported that their salary is based on finishing a specific number of items per day. Syrian refugee child workers need immediate protection to safeguard their health. Interventions could target children of legal age for work in safer conditions and keep younger children out of work.


Subject(s)
Child Welfare/statistics & numerical data , Occupational Diseases/epidemiology , Refugees/statistics & numerical data , Adolescent , Child , Child Welfare/psychology , Ergonomics/methods , Female , Humans , Male , Occupational Diseases/psychology , Occupations/classification , Refugees/psychology , Reproducibility of Results , Rescue Work , Sex Factors , Syria
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