Mechanical Dispersion Research Articles

Clinical study of two-dimensional speckle tracking to evaluate abnormal myocardial motion due to coronary lesions.

To investigate the predictive ability of global longitudinal strain (GLS) and mechanical dispersion for coronary stenosis and provide a more reliable noninvasive method for diagnosis of obstructive coronary artery disease(OCAD). Sixty-seven patients diagnosed with suspected CAD were included in the study. Patients with coronary stenosis greater than 50% were assigned as OCAD, while the others were assigned as non obstructive coronary artery disease(NOCAD). General information was collected and patients underwent speckle tracking echocardiogram(STE). Spearman's correlation analysis showed that GLS and mechanical dispersion were positively correlated with the degree of coronary stenosis (r=0.383, 0.342, p<0.05), and there was also a positive correlation between GLS and mechanical dispersion (r=0.327, p<0.05). GLS, longitudinal strain (LS) of each chamber, and mechanical dispersion were higher in the OCAD group than in the NOCAD group (p<0.05). Univariate regression analysis showed that GLS, each lumen LS and mechanical dispersion were statistically significant (p<0.05). Multifactorial regression analysis showed that elevated GLS (p=0.007) and elevated mechanical dispersion (p=0.030) were independent risk factors for OCAD. The ROC curves showed that GLS predicted OCAD (AUC area 0.745, 95% CI 0.624 to 0.865) versus mechanical discrete prediction of OCAD (AUC area 0.702, 95% CI 0.569 to 0.834) were more diagnostic than conventional cardiac ultrasound observations of ventricular wall motion abnormalities (AUC area 0.566, 95% CI 0.463 to 0.669). Combining GLS with mechanical dispersion can rapidly assess OCAD in a very short period, which has strong promotion value and in-depth research value.

APPLICATION OF ACTIVATING INFLUENCES IN OBTAINING TiO2-PILLARED MONTMORILLONITE WITH IMPROVED PHOTOCATALYTIC PROPERTIES

A new approach to the obtaining of a highly efficient photocatalyst - TiO2-pillared montmorillonite – by hydrothermally activated intercalation of mechanically dispersed bentonite matrix with the polyhydroxocomplexes of titanium is proposed. The material was characterized by the X-ray diffractometry, low-temperature nitrogen adsorption-desorption, scanning electron microscopy, energy dispersive microanalysis, and zeta potential measurement. The use of short-term (up to 3 min) mechanical dispersion in a planetary mill significantly increases the capacity of cation exchange during intercalation, and the photocatalysts obtained after annealing at 500 °C are characterized by significantly higher values of specific surface area and total pore volume compared with mechanically untreated and initial montmorillonite. The average size of TiO2 crystallites is about 10 nm and the content of anatase is over 90%. Mechanical activation leads to a significant change in the ζ-potential of montmorillonite particles from a significantly negative value in the source material to almost zero, which is an additional argument for more efficient intercalation. Hydrothermal treatment leads to the appearance of coral-like formations of titania on the surface of montmorillonite, and after mechanical treatment they significantly increase in size. Adsorption and photocatalytic properties were studied in a quartz reactor using the rhodamine B dye as example. Complete photocatalytic destruction of the dye was achieved within about 100 min (initial concentration of 40 mg/l, amount of photocatalyst 1 g/l, UV lamp power 250 W). Adsorption kinetics is described by pseudo-first and pseudo-second order models. The kinetics of photocatalysis is described by the Langmuir-Hinshelwood model. The high photoactivity is explained both by the improvement of textural properties and the appearance of additional photocatalytic centers due to the defective structure of mechanically activated montmorillonite.

Физико-химические трансформации сапонитсодержащего материала при его активации измельчением

Structural-phase transformations on the surface of powder systems of saponite-containing material after mechanical dispersion have been studied. The degree of crystallinity, adsorption capacity and specific surface energy depending on the time mode of grinding were used as compared information characteristics. It has been established that, despite the fact of the constancy of the degree of crystallinity, mechanical grinding of saponite-containing raw materials leads to its activation, which is expressed by a proportional increase in the sorption capacity of the obtained powders, an increase in the concentration of active adsorption centers and the value of the specific free surface energy. An increase in the time of mechanical grinding of a saponite-containing material leads to the production of samples with an increased (compared to the initial material) surface hydrophilicity.

Retracted: Experimental Testing on Mechanical, Durability, and Adsorption Dispersion Properties of Concrete with Multiwalled Carbon Nanotubes and Silica Fumes

Retracted: Experimental Testing on Mechanical, Durability, and Adsorption Dispersion Properties of Concrete with Multiwalled Carbon Nanotubes and Silica Fumes

Preparation, In-vitro, and Ex-vivo Evaluation of Ondansetron Loaded Invasomes for Transdermal Delivery

Invasomes are newly developed types of nanovesicles. A vesicular drug delivery system is considered one of the approaches for transdermal delivery to enhance permeation and improve drug bioavailability. Ondansetron is a serotonin receptor antagonist used for treating vomiting associated with different clinical cases. The study aimed to prepare invasomal dispersions for improving permeation of ondansetron across the skin with a controlled release pattern. Twenty-seven formulas of ondansetron-loaded invasomes were prepared by a modified mechanical dispersion method. These formulas were optimized by studying the effect of variables on entrapment efficiency. Vesicle size, polydispersity, zeta potential, in-vitro release and ex-vivo permeation studies were done for the optimized formulas. The selected formula was )F25( had )88.24%±0.04 (entrapment, (317.7 nm) vesicle size, (0.29) polydispersity, and (-31.5mV) zeta potential. In-vitro release study showed That (F25) had 75% release after (12) hrs., and dissolution followed the Korsmeyer-Peppas model with anomalous diffusion. Ex-vivo permeation study showed steady-state flux was 340.2 µg/cm2.hr with no lag time using rat skin tissue. A transmission electron microscope was done to visualize the selected formula. Invasomes are considered promising drug delivery systems for transdermal delivery of ondansetron, ensuring efficient permeation with a sustained release pattern.

Mechanical Dispersion Is Associated With Ventricular Arrhythmias and Sudden Cardiac Death in Nonischemic Dilated Cardiomyopathy

Mechanical Dispersion Is Associated With Ventricular Arrhythmias and Sudden Cardiac Death in Nonischemic Dilated Cardiomyopathy

ОПТИМИЗАЦИЯ КОНСТРУКТИВНЫХ И РЕЖИМНЫХ ПАРАМЕТРОВ ТУРБИННОЙ МЕШАЛКИ ДЛЯ ДИСПЕРГИРОВАНИЯ РАСТВОРОВ ПОЛИМЕРНЫХ КОМПОЗИТОВ

The use of polymer composites in the restoration of worn-out body parts of agricultural machinery significantly increases their post-repair life and leads to significant savings in material resources during repair. The composite should have high mechanical and thermophysical properties, which is possible provided that the filler particles are evenly distributed in the volume of the solution. Aggregation of particles, their non-uniform distribution in the polymer solution significantly impairs the performance of the material. Mechanical mixing and dispersion of polymer composite solutions using agitators is a promising treatment method that improves the consumer properties of the material. Theoretical studies were carried out and, taking into account the physical properties of the elastomeric nanocomposite solution, the design of the open turbine stirrer was chosen. It has been found that when developing a device with a stirrer, the effect of the design parameters of the stirrer on the power consumed by the device on the mixing of components, as well as the quality of mixing and dispersion of the polymer composite solution should be taken into account. The effect of the design parameters of the stirrer on the power consumption was analyzed and the design parameters of the stirrer were determined. An active experiment according to the plan was implemented V2 in which the response function took the estimated parameter of the mixing quality of the light transmission coefficient, and the factors of the inclination angle of the stirrer blade and its rotation frequency. A regression model in the form of a second-order polynomial was obtained and its optimization was carried out. The optimal design and operating parameters of the stirrer have been established, which ensure the highest quality of mixing solutions. Based on the results of the studies, the design of an open, turbine stirrer for mixing nanocomposite solutions was developed.

(Invited) Lithium Phosphorus Sulfide Chloride-Polymer Composite Via Solution-Precipitation Process for Improving Stability Toward Dendrite Formation of Li-Ion Solid Electrolyte

Improving the mechanical strength of ceramic solid electrolytes such as lithium phosphorus sulfide families for pressure-driven dendrite blocking as well as reducing the electronic conductivity to prevent a dendrite formation inside the electrolytes are very important to extend the lifespan of all-solid-state lithium-metal batteries. Here, we propose a low-temperature solution−precipitation process to prepare polymer−solid electrolyte composites for a highly uniform polymer distribution in the electrolyte to enhance their mechanical strength and reduce their electronic conduction. The composites with up to 12 wt % of polymer are prepared, and the composites exhibit high ionic conductivities of up to 0.3 mS/cm. Furthermore, the electrochemical stability of the electrolyte composites on Li striping/plating cycles is investigated. We confirm that the proposed solution precipitation process makes the composite much more stable than the bare solid electrolyte and causes them to outperform similar composites from the other existing preparation methods, such as mechanical mixing and solution dispersion.

Imaging for the assessment of the arrhythmogenic potential of mitral valve prolapse.

Mitral valve prolapse (MVP) is the most common valve disease in the western world and recently emerged as a possible substrate for sudden cardiac death (SCD). It is estimated an annual risk of sudden cardiac death of 0.2 to 1.9% mostly caused by complex ventricular arrhythmias (VA). Several mechanisms have been recognized as potentially responsible for arrhythmia onset in MVP, resulting from the combination of morpho-functional abnormality of the mitral valve, structural substrates (regional myocardial hypertrophy, fibrosis, Purkinje fibers activity, inflammation), and mechanical stretch. Echocardiography plays a central role in MVP diagnosis and assessment of severity of regurgitation. Several abnormalities detectable by echocardiography can be prognostic for the occurrence of VA, from morphological alteration including leaflet redundancy and thickness, mitral annular dilatation, and mitral annulus disjunction (MAD), to motion abnormalities detectable with "Pickelhaube" sign. Additionally, speckle-tracking echocardiography may identify MVP patients at higher risk for VA by detection of increased mechanical dispersion. On the other hand, cardiac magnetic resonance (CMR) has the capability to provide a comprehensive risk stratification combining the identification of morphological and motion alteration with the detection of myocardial replacement and interstitial fibrosis, making CMR an ideal method for arrhythmia risk stratification in patients with MVP. Finally, recent studies have suggested a potential role in risk stratification of new techniques such as hybrid PET-MR and late contrast enhancement CT. The purpose of this review is to provide an overview of the mitral valve prolapse syndrome with a focus on the role of imaging in arrhythmic risk stratification. CLINICAL RELEVANCE STATEMENT: Mitral valve prolapse is the most frequent valve condition potentially associated with arrhythmias. Imaging has a central role in the identification of anatomical, functional, mechanical, and structural alterations potentially associated with a higher risk of developing complex ventricular arrhythmia and sudden cardiac death. KEY POINTS: • Mitral valve prolapse is a common valve disease potentially associated with complex ventricular arrhythmia and sudden cardiac death. • The mechanism of arrhythmogenesis in mitral valve prolapse is complex and multifactorial, due to the interplay among multiple conditions including valve morphological alteration, mechanical stretch, myocardial structure remodeling with fibrosis, and inflammation. • Cardiac imaging, especially echocardiography and cardiac magnetic resonance, is crucial in the identification of several features associated with the potential risk of serious cardiac events. In particular, cardiac magnetic resonance has the advantage of being able to detect myocardial fibrosis which is currently the strongest prognosticator.

Optimizing quality and mixing performance of processed cheese spread using a mechanical universal disperser

Processed cheese spread (PCS) is currently experiencing rapid growth and is recognised as a prominent segment within the cheese‐based product industry worldwide. This type of cheese spread is produced by comminuting and blending natural cheese of varying ages and degrees of maturity, along with other ingredients, to achieve a homogeneous plastic mass. The high viscosity of PCS necessitates thorough mixing and blending, posing a challenge for cheese processors. In this study, a mechanical unit known as a universal disperser was utilised to prepare PCS. The study aimed to evaluate the impact of different processing parameters on the quality of the final product. Response surface methodology (RSM) was employed to design the experiment and optimise the process accordingly. The experiment involved conducting trials at three distinct melting temperatures: 50, 65 and 80 °C. The impeller speed used for blending the content was set at three levels: 10 000, 15 000 and 20 000 r.p.m. Responses, such as mixing index, mixing time, power consumption, spreadability, and overall acceptability, were recorded. Based on the findings, it was concluded that by employing the optimal parameters, a high‐quality PCS with a desirable overall acceptability score of 8.3 could be achieved while also meeting the desired mixing performance.

Heat losses in ATES systems: The impact of processes, storage geometry and temperature

The technical and economic success of an Aquifer Thermal Energy Storage (ATES) system depends strongly on its thermal recovery efficiency, i.e. the ratio of the amount of energy that is recovered to the energy that was injected. Typically, conduction most strongly determines the thermal recovery efficiency of ATES systems at low storage temperatures (<25 °C), while the impact of buoyancy-driven flow can lead to high additional heat losses at high storage temperatures (>50 °C). To date, however, it is unclear how the relative contribution of these processes and mechanical dispersion to heat losses across a broad temperature range is affected by their interaction for the wide range of storage conditions that can be encountered in practice. Since such process-based insights are important to predict ATES performance and support the design phase, numerical thermo-hydraulic ATES simulations were conducted for a wide range of realistic operational storage conditions ([15–90 °C], [50,000–1,000,000 m3/year]) and hydrogeological conditions (aquifer thickness, horizontal hydraulic conductivity, anisotropy). The simulated heat loss fractions of all scenarios were evaluated with respect to analytical solutions to assess the contribution of the individual heat loss processes. Results show that the wide range of heat losses (10–80 % in the 5th year) is the result of varying contributions of conduction, dispersion and buoyancy-driven flow, which are largely determined by the geometry of the storage volume (ratio of screen length / thermal radius, L/Rth) and the potential for buoyancy-driven flow (q0) as affected by the storage temperature and hydraulic conductivity of the aquifer. For ATES systems where conduction dominates the heat losses, a L/Rth ratio of 2 minimizes the thermal area over volume ratio (A/V) and resulting heat losses for a given storage volume. In contrast however, the impact of dispersion decreases with L/Rth and particularly for ATES systems with a high potential for buoyancy-driven flow (q0 > 0.05 m/d), increasingly smaller L/Rth ratios (<1) strongly reduce the heat losses due to tilting. Overall, the results of this study support the assessment of thermal recovery efficiencies for particular aquifer and storage conditions, thereby aiding the optimization of initial ATES designs.

Epicardial fat and left atrial mechanical dispersion in patients with hypertension with persistent atrial fibrillation and without cardiac arrhythmia

Aim. To study the relationship between the amount of epicardial left atrial fat and left atrial mechanical dispersion (LAMD) in hypertensive patients with persistent atrial fibrillation (AF) and without cardiac arrhythmias.Material and methods. The main group included 100 hypertensive patients with persistent AF, who underwent transesophageal echo cardiography (TEE) before the elective cardioversion, and transthoracic echocardiography (TTE) after cardioversion and disappearance of atrial stunning. The control group included 24 hypertensive patients without cardiac arrhythmias, who underwent TEE for other indication. The thickness of atrial septum and left lateral ridge was measured by TEE. The average thickness of these structures was designated as left atrial fat. The time to peak of longitudinal myocardial strain in 6 left atrium segments was determined by speckle-tracking echocardiography. LAMD was calculated as a percentage of the standard deviation of the obtained values to cardiac cycle duration.Results. The median left atrial fat thickness in the main and control groups was 8,03 [6,78; 8,95] and 5,23 [4,48; 5,80] mm (p&lt;0,0001), median LAMD — 2,68 [2,41; 2,83] and 0,95 [0,62; 1,11]% (p&lt;0,0001). There was a positive correlation between left atrial fat thickness and LAMD in the main group (r=0,556; p&lt;0,0001). This relationship did not reach the level of statistical significance in the control group, (r=0,358; p=0,0860). There was no independent relationship between body mass index and left atrial fat thickness in the patients (r=0,027; p=0,7651).Conclusion. In hypertensive patients with persistent AF, compared with patients without rhythm disturbances, the average values of left atrial fat thickness and LAMD are significantly higher. The increase in left atrial fat thickness is associated with the increase in LAMD in hypertensive patients with AF. There was no correlation between left atrial fat thickness and LAMD in hypertensive patients without rhythm disturbances. There was no effect of body mass index on left atrial fat thickness in the present study.

Left ventricular mechanical dispersion as a predictor of the need for pacemaker implantation after transcatheter aortic valve implantation: MeDiPace TAVI study.

Permanent pacemaker (PM) implantation is common after transcatheter aortic valve implantation (TAVI). Left ventricular mechanical dispersion (MeDi) by speckle tracking echocardiography is a marker of fibrosis that causes alterations in the conduction system. We hypothesized that MeDi can be a predictor of the need for PM implantation after TAVI. Consecutively, 200 TAVI patients were enrolled. Transthoracic echocardiography and electrocardiography examinations were recorded before TAVI to evaluate global longitudinal strain (GLS), MeDi, and conduction disturbances. PM implantation information was obtained 3 months after TAVI. Patients were stratified into PM or no PM group. Mean age was 80 + 7 years (44% women). Twenty-nine patients (16%) received PM. MeDi, QRS duration, existence of right bundle branch abnormality (RBBB), and first-degree atrioventricular (AV) block were significantly different between groups. MeDi was 57 ± 15 ms and 48 ± 12 ms in PM and no PM groups, respectively (P < 0.001). In multivariate analysis, MeDi predicted the need for PM after TAVI independently of GLS, QRS duration, RBBB, and first-degree AV block [odds ratio (OR): 1.73, 95% confidence interval (CI): 1.22-2.45] with an area under the curve (AUC) of 0.68 in receiver operating characteristic (ROC) curves. Moreover, RBBB was an independent predictor of PM need after TAVI (OR: 8.98, 95% CI: 1.78-45.03). When added to RBBB, MeDi had an incremental predictive value with an AUC of 0.73 in ROC curves (P = 0.01). MeDi may be used as an echocardiographic functional predictor of the need for PM after TAVI.

Left ventricular speckle-tracking-derived mechanical dispersion in patients with transthyretin amyloidosis and their first-degree relatives

Abstract Background Mechanical dispersion has shown to predict ventricular (LV) arrhythmias and sudden cardiac death in populations with established cardiac diseases, such as cardiomyopathies and heart failure. Transthyretin amyloid (ATTR) cardiomyopathy arises from deposition of misfolded, insoluble transthyretin (TTR) in extracellular matrix. The disease impacts profoundly cardiac tissue architecture and its mechanical properties. Purpose The aim of this prospective study was assessment of LV speckle-tracking-derived mechanical dispersion in patients with ATTR cardiomyopathy and their first-degree relatives. Methods We present data based on evaluation of 85 patients, including 34 (group 1) index patients with ATTR and 51 (group 2) first-degree relatives who were studied between June 2020 and January 2023. Study protocol included clinical data, free light chain blood immunoglobulins and urine immunofixation, transthoracic echocardiography (TTE) with global longitudinal strain (GLS) analysis, hybrid technique single-photon emission computed tomography and computed tomography (SPECT/CT) with [99mTc] Tc 3,3-disphono-1,2-propanodicarboxylic acid (DPD), genetic testing by an amplicon-based next-generation TTR sequencing approach, and in selected cases cardiac or soft tissue biopsy. Mechanical dispersion was calculated manually from GLS measurements and defined as the standard deviation (SD) of contraction duration from R on the electrocardiogram (ECG) to peak negative longitudinal strain of all LV segments. Results In group 1 patients were older (66.6±11 vs. 50.7±14) and presented with higher New York Heart Association (NYHA) class (2.4± 1 vs. 1.1± 0.6) (p&amp;lt;0.05). Overall, there were detected following types of TTR variants - Phe53Leu, Ala101Val, Glu112Lys, Glu109Lys, Glu122Lys, Glu82Lys. Compared to group 2, group 1 presented with higher N-terminal (NT)-pro hormone BNP (NT-proBNP) value (5859±7320 vs. 281±990 pg/ml), greater intraventricular septum thickness (19±4 vs. 12±3 mm) and LV mass index values (199±69 vs.111±42 g/m2), impaired LV ejection fraction (44±13 vs. 59±10 %) and GLS (-12.7±6 vs. -18.7±4 %) (p&amp;lt;0.05). Moreover, patients with ATTR cardiomyopathy had significantly higher value of LV speckle-tracking-derived mechanical dispersion compared to their first-degree relatives (96.2±22.3 vs. 77.9±23.3 ms, p=0.0007). Conclusions Patients with ATTR cardiomyopathy present with significantly higher LV mass index value, impaired GLS and higher value of LV speckle-tracking-derived mechanical dispersion compared to their first-degree relatives (p&amp;lt;0.05). Assessment of LV speckle-tracking-derived mechanical dispersion may in future translate into further enhancement of disease evaluation and improving prognosis in the group of patients.

The assessment of left atrial and left atrial appendage mechanics in patients with different stages of atrial fibrillation

Abstract Background Atrial fibrillation (AF) is associated with left atrial (LA) mechanical dysfunction, which predisposes to stasis of blood within the LA and thus increases the risk of stroke. However, limited is known about the mechanical functional alterations of left atrial appendage (LAA) in relation to stages of AF. Here, we sought to analyse LA and LAA mechanics during different stages of AF in detail. Methods A total of 92 patients with AF referring for radiofrequency ablation were consecutively enrolled. Patients were categorized according to rhythm and stages of AF:sustained AF(SAF) (n=31), paroxysmal AF with sinus rhythm(PAF-SR)(n=30) andAF rhythm(PAF-AF)(n=31)at the time of echocardiography. Twenty-seven patients without a history of AF were included as controls. Using speckle-tracking echocardiography, LA and LAA global peak positive longitudinal strain (GLS) and mechanical dispersion (MD) were measured in all patients. Mechanical dispersion was defined as the standard deviation of the time to peak of the regional strain corrected by R-R interval. Results Patients with PAF-AF and SAF displayed prominently impaired LA and LAA mechanics(all P &amp;lt; 0.01 vs. PAF-SR and no AF). In the presence of SR, only LAA mechanical function were lower in PAF patients than patients without AF(LAA GLS 20.5±5.7%(no AF) vs 15.9±5.4%(PAF-SR); LAA MD 6.9±3.8%(no AF) vs 9.4±3.9(PAF-SR),both P&amp;lt;0.01). AF stages were independent determinants of LA and LAA mechanics after adjusting for age and comobidities. Conclusions AF affected mechanical function of LA and LAA on their own, and more so if stage of AF has advanced to more persistent forms. In addition, LAA mechanical dysfunction occurred earlier than that of LA.fig 1fig 2

Identification of novel risk profiles for ventricular arrythmias in hypertrophic cardiomyopathy through clustering analysis including left ventricular strain data

Abstract Aims The excess mortality in hypertrophic cardiomyopathy (HCM) patients is mainly attributed to the occurrence of ventricular arrythmias (VA) and sudden cardiac death (SCD). The prediction of VA remains challenging and could be improved. The aim of the study was to characterize VA risk profile in HCM patients through clustering analysis combining clinical and conventional imaging parameters with information derived from left ventricular longitudinal strain analysis (LV-LS). Methods A total of 434 HCM patients (65% men, mean age 56 years) were retrospectively included from two referral centers from two different countries and followed longitudinally (mean duration 6 years). Mechanical and temporal parameters were automatically extracted from the LV-LS segmental curves of each patient in addition to conventional clinical and imaging data. A total of 287 features were analyzed using a clustering approach (k-means). The first endpoint for ventricular arrythmias (VA) included suspected SCD, aborted cardiac arrest, appropriate ICD therapy (AIT), sustained ventricular tachycardia (SVT) and non-sustained ventricular tachycardia (NSVT) during follow-up. Results 4 clusters were identified with a higher rhythmic risk for cluster 1 and 4 (VA rates of 26%(28/108), 13%(13/97), 12%(14/120), and 31%(34/109) for cluster 1,2,3 and 4 respectively) (Figure 1). These 4 clusters have been mainly separated based on LV strain parameters with severe and homogeneous decrease of myocardial deformation for cluster 4 (global longitudinal strain (GLS) -11%), a small decrease for cluster 2 and 3 (GLS -17.2 and -16.3%, respectively) and a marked mechanical and temporal dispersion for cluster 1 associated with a moderate decrease of the GLS (-15.3%; p &amp;lt;0.0001 for GLS comparison between clusters) (Figure 2). Patients from cluster 4 had the most severe phenotype (mean LV mass index 123 vs. 112 g/m²; p=0.0003) with marked diastolic dysfunction (left atrial volume index (LAVI) 46.6 vs. 41.5 ml/m² for others clusters; p=0.04) and impaired exercise capacity (% predicted peak work 58.6 vs. 69.5%; p= 0.025). Patient from cluster 2 had the less severe phenotype (mean LV mass index 99.6 vs. 121 g/m²; p=0.0001 and LAVI 37.2 vs. 44.3 ml/m²; p=0.04). Patients from cluster 3 and 1 had a moderate phenotype and were older in cluster 3 (mean age 62.1 vs. 54.1 years; p &amp;lt; 0.0001) and had more obstructive form in cluster 1 (peak gradient LV outflow tract ≥ 30 mmHg for 36 vs. 23% of patients; p=0.046) with a larger left atrium size (LAVI 45.8 vs. 41.7 ml/m²; p=0.0023). Conclusion Using a clustering approach processing LV-LS parameters in HCM patients identified 4 clusters with specific LV-strain patterns and different rhythmic risk level. In the future, the automatic extraction and analysis of LV strain parameters could help to improve the risk stratification for SCD in HCM patients.Figure 1:Survival curvesFigure 2:Different strain patterns

Left atrial mechanics evaluated by two-dimensional strain analysis: alterations in essential hypertension.

Hypertension is a cardiovascular risk factor that predisposes to cardiac structural alterations namely increased left ventricular (LV) wall thickness, reduced LV compliance and diastolic dysfunction, with consequent left atrial (LA) dilation and functional impairment. In this article, we evaluated differences in left atrial structure and function using two-dimensional speckle tracking echocardiography in patients with hypertension compared with controls. This was a retrospective cross-sectional study of 208 hypertensive patients and 157 controls who underwent a comprehensive transthoracic echocardiogram. Patients with hypertension were stratified by the presence of left ventricular hypertrophy (LVH). Non-LVH hypertension patients had lower left atrial reservoir strain (LAS RES ) (34.78 ± 29.78 vs. 29.78 ± 6.08; P = 0.022) and conduit strain (LAS CD ) (19.66 ± 7.29 vs. 14.23 ± 4.59; P = 0.014) vs. controls despite similar left atrial volumes (LAV) . Left atrial contractile strain (LAS CT ) was not significantly different between non-LVH hypertension patients and controls (15.12 ± 3.77 vs. 15.56 ± 3.79; P = 0.601). Left atrial mechanical dispersion was significantly higher in the LVH group compared with the non-LVH hypertension group (42.26 ± 13.01 vs. 50.06 ± 14.95; P = 0.009). In multivariate regression analysis, LVH correlated with left atrial mechanical dispersion ( P = 0.016). An age-hypertension interaction independently correlated with LAS CT ( P < 0.001). Hypertension results in functional left atrial changes even before development of LV hypertrophy and structural left atrial changes with increased left atrial volume. We demonstrate both a likely hypertension-associated left atrial myopathy that prevents age-related compensatory increase in left atrial contractile function, and impact of LVH in hypertension on left atrial dyssynchrony.

Niosomes based formulation containing tenoxicam: A newer solution for the rheumatic diseases

This investigation aimed to explore the potential of non-ionic surfactant based niosomal vesicles encapsulating tenoxicam (TN; anti-rheumatic drug) for the treatment of rheumatic diseases. Mechanical dispersion technique with controlled pressure was employed to prepare different niosomal formulations. The effects of different ratios of surfactant (span-60), lipid, and sodium deoxycholate on noisome's physicochemical properties have been examined. Moreover, inhibition of TNF-α in lipopolysaccharide-activated cultured Human leukemia monocytic (THP-1) cells were demonstrated to assess the in vitro inflammation profile. Finally, the optimized niosomal formulation (TN3) was prepared in gel matrix consist of carbopol 934 (termed as TN34) and stability was also tested at 4±2̊C, 25±2̊C, 37±2̊C and 45±2̊C for 6months. The optimized niosomal formulation exhibited a small vesicle size (165±14nm) and high drug encapsulation (79.64±1.5%). Niosomal gel formulation TN34 showed pH (6.7), viscosity (6810±3.34cps), spreadability (19.11±1.87gm.cm/sec) and also displayed sustained release pattern of drug release (98.16±0.07% TN released from gel matrix in 24h) in vitro release study. TN34 exhibited substantial anti-inflammatory response, with ∼75% inhibition of TNF-α in 48h. Stability investigation revealed that refrigerator temperature is most suitable for the storage of niosomal gel. Transdermal niosomal formulation displayed promising potential in the treatment of rheumatic diseases.

Effect of Nano-Clay Dispersion on Pore Structure and Distribution of Hardened Cement Paste

Nano-clay has the potential to improve the properties of cement-based materials. However, the effectiveness of this improvement is influenced by the dispersion of the nano-clay. The effects of different nano-clay dispersion techniques on cement-based material properties and pore structure complexity were studied. The samples were prepared using manual and mechanical dispersion methods. The mechanical properties of the specimens were evaluated, and the pore characteristics of the cement-based materials were analysed using mercury intrusion porosimetry. The study investigated the effect of the dispersion method on the nano-clay dispersion. The complexity of the pore structure was evaluated using a fractal model, and the relationship between the fractal dimension, mechanical properties, and pore structure was analysed. The findings indicate that mechanical dispersion results in better dispersion than manual dispersion, and the mechanical properties of mechanical dispersion are superior to those of manual dispersion. Nano-clay particles can improve the internal pore structure of cement materials. Through mathematical calculation, the surface fractal dimension is between 2.90 and 2.95, with good fractal characteristics. There is a good correlation between the surface fractal dimension and the mechanical properties. The addition of nano-clay can reduce the complexity of the pore structure, and the fractal dimension has an excellent linear relationship with the pore structure.

Dimensionless Thermal Efficiency Analysis for Aquifer Thermal Energy Storage

AbstractSeasonal warm and cold water storage in groundwater aquifers is a cost‐effective renewable energy technology for indoor heating and cooling. Simple dimensionless analytical solutions for the thermal recovery efficiency of Aquifer Thermal Energy Storage (ATES) systems are derived, subject to heat losses caused by thermal diffusion and mechanical dispersion. The analytical solutions pertain to transient pumping rates and storage durations, and multiple cycles of operation, and are applicable to various well configurations and thermal plume geometries. Heat losses to confining layers, its implications for optimizing plume geometries and aspect ratios, and heat spreading due to free convection are also discussed. This provides a general tool for broad and rapid assessment of aquifers and ATES systems. We show that if heat exchange with the confining layers is negligible, the thermal recovery efficiency of thermal plumes with cylindrical geometry is independent of the aquifer porosity and heat capacity C0. Therefore, if mechanical dispersion is negligible as is often the case, the only aquifer property that affects the recovery efficiency is the aquifer thermal conductivity. The field‐scale aquifer thermal conductivity λ can therefore be inferred from the recovery efficiency of a push‐pull heat recovery test. Remarkably, an increase in C0 could either increase, decrease, or not affect the recovery efficiency, depending on the thermal plume geometry. Hence, the analytical solutions reveal that the recovery efficiency is affected by complex interactions between the thermal plume geometry and aquifer properties. Approximate analytical solutions for subsurface temperature profiles over an entire ATES cycle are also derived.