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Abstract In this article, we develop a new class of solutions that describe stellar structures of recently observed pulsars. We adopt the condition of the vanishing complexity proposed by Herrera (Phys Rev D 97:044010, 2018) and an appropriate metric potential for generating the solutions. The solutions which are obtained from the complexity-free conditions, are physically well-behaved and satisfy all the rigorous conditions to describe static and spherically symmetric realistic compact objects. The features of observed anisotropic compact stars including Vela X-1, LMC X-4, Cen X-3, and EXO 1785-248 are validated with our model. It is further shown that the solutions supporting matter configurations are physically plausible, stable with positive anisotropy, and in an equilibrium state as verified by investigating the generalized TOV equation in the case of our model.

Abstract In the present article anisotropic solutions with vanishing complexity in the framework of f(Q) gravity are generated. At first, the field equations in f(Q)-gravity are gravitationally decoupled where the isotropic fluid component corresponds to Vlasenko–Pronin space-time. Then, with a new source, the complete geometric deformation is supplemented to an isotropic component, and the related deformation function is derived by the method known as mimicking of mass constraints. Furthermore, the generated anisotropic solution prevails all the physical tests along with the stability analysis with respect to the decoupling parameter as well as the f(Q) gravity parameter and it accomplishes the physical representation of observational constraint related to stars, namely, SMC X-1, 2 S 0921-630, PSR J0437-4715, Vela X-1, PSR J1748-2021B which are reflected in Mass–Radius curves. Hence, the study comes out to be worthy of the fact that the f(Q) gravity parameter directly influences the maximum mass of a compact stellar configuration for the fixed decoupling parameter in the context of gravitational decoupling where it predicts the star PSR J1748-2021B having highest mass 2.74 $$M_{\odot }$$ M ⊙ . It is noted that when the decoupling parameter ( $$\alpha $$ α ) increases, the central value of the adiabatic index value also increases, while the reverse situation occurs when the f(Q)-parameter ( $$\beta _1$$ β 1 ) gets increased. This implies that both the parameters $$\alpha $$ α and $$\beta _1$$ β 1 have the overall controlling power on the stability of the model.

Sea cucumbers are well demarcated for their valuable role in the food, pharmaceutical, nutraceutical, and cosmeceutical sectors. The demand for well-processed dried sea cucumber retaining quality is prioritized by local markets and industries. There are several techniques for the pre-processing of fresh sea cucumbers, including traditional and modern methods, such as salting, boiling, high-pressure processing, high-pressure steaming, and vacuum cooking, among others, in order to inactivate enzymes and microbial attacks. Further, pre-treated sea cucumbers require post-processing before human consumption, transportation, or industry uses such as hot air, freeze, cabinet, sun, or smoke drying. However, despite the ease, traditional processing is associated with several challenges hampering the quality of processed products. For instance, due to high temperatures in boiling and drying, there is a higher chance of disrupting valuable nutrients, resulting in low-quality products. Therefore, the integration of traditional and modern methods is a crucial approach to optimizing sea cucumber processing to obtain valuable products with high nutritional values and retain bioactive compounds. The value of dried sea cucumbers relies not only on species and nutritional value but also on the processing methods in terms of retaining sensory attributes, including colour, appearance, texture, taste, and odour. Therefore, this review, for the first time, provides insight into different pre- and post-treatments, their perspective, challenges, and how these methods can be optimized for industry use to obtain better-quality products and achieve economic gains from sea cucumber.

This report presents an insightful investigation of the cold crystallization behavior of sulfur-crosslinked polybutadiene elastomers. The influence of crosslink density on the cold crystallization activities of sulfur-crosslinked polybutadiene rubber (BR) is investigated using differential scanning calorimetry, dynamic mechanical analysis, and X-ray techniques. A significant increase in storage modulus (E') is observed at a temperature just above the glass transition temperature (Tg). This behavior was found to be highly dependent on the crosslink density of the rubber. The dynamic mechanical behavior of the sulfur crosslinked BR is supported by further studies using differential scanning calorimetry and low-temperature X-ray diffraction. This study could contribute to a better understanding of the behavior of BR-containing tire tread rubbers at lower temperatures.

Abstract Dielectric elastomer actuators (DEAs) are one of the emerging areas of investigation in smart elastomer research and have attracted considerable interests due to their wide‐ranging applications, for instance in automation and soft robotic components. Commonly utilized dielectric elastomers (DEs) such as nitrile butadiene rubber (NBR) and its hydrogenated and carboxylated derivatives along with the dielectric fillers (titanium oxide, barium titanate, etc.) were considered to be one of the most established composite systems demonstrating high actuation performance. When subjected to external electrical field, the DEAs derived from the composites were, therefore, capable of reproducing high energy density and large deformation with fast response time. The recent research emphasizes that tunable material properties eventually triggered the improved actuation performance. The exploration of compliant electrodes fabricated by the conventional and state‐of‐the‐art lithographic methods was also crucial to improve actuation performance for the soft robotic applications. This review summarizes the commonly used DEs and dielectric fillers, their performances and challenges, and outlines the research progress (experimental and theoretical) in the field of actuators. Finally, a brief introduction to DEA‐based soft robotics application is also presented.

Tracking macrophages by non-invasive molecular imaging can provide useful insights into the immunobiology of inflammatory disorders in preclinical disease models. Perfluorocarbon nanoemulsions (PFC-NEs) have been well documented in their ability to be taken up by macrophages through phagocytosis and serve as 19F magnetic resonance imaging (MRI) tracers of inflammation in vivo and ex vivo. Incorporation of near-infrared fluorescent (NIRF) dyes in PFC-NEs can help monitor the spatiotemporal distribution of macrophages in vivo during inflammatory processes, using NIRF imaging as a complementary methodology to MRI. Here, we discuss in depth how both colloidal and fluorescence stabilities of the PFC-NEs are essential for successful and reliable macrophage tracking in vivo and for their detection in excised tissues ex vivo by NIRF imaging. Furthermore, PFC-NE quality assures NIRF imaging reproducibility and reliability across preclinical studies, providing insights into inflammation progression and therapeutic response. Previous studies focused on assessments of colloidal property changes in response to stress and during storage as a means of quality control. We recently focused on the joint evaluation of both colloidal and fluorescence properties and their relationship to NIRF imaging outcomes. In this protocol, we summarize the key assessments of the fluorescent dye–labeled nanoemulsions, which include long-term particle size distribution monitoring as the measure of colloidal stability and monitoring of the fluorescence signal. Due to its simplicity and reproducibility, our protocols are easy to adopt for researchers to assess the quality of PFC-NEs for in vivo NIRF imaging applications.

In this work, the crosslinking reaction of epoxidized natural rubber (50 mol% epoxy, ENR-50) by metal ion namely ferric ion (Fe3+, FeCl3, ferric chloride) was studied. It was found that a direct interaction of the ferric ion with the epoxy group as well as internal polymerization enable the ENR to be efficiently cured. The vulcanizing ENR-FeCl3 compound was then reinforced by carbon nanotubes (CNTs). The FTIR spectra of ENR-FeCl3 compounds without and with CNTs show the absorption peak at the wavenumber 470 cm–1, which represents the –O–Fe–O– linkages from a reaction of FeCl3 and opened oxirane ring products of ENR molecules. Furthermore, the ENR-FeCl3 compounds show a typical marching curing curve with a steady increase in torque as increasing of the testing time; especially the effect is more pronounced in CNTs filled system. Furthermore, an increase in the concentration of CNTs causes increasing in torque difference and enhancement of the mechanical properties (i.e., 100% moduli and tensile strength). The SEM micrograph shows good compatibility between CNTs and the rubber matrix in the ENR-FeCl3 compounds. Also, the electrical conductivities of ENR-FeCl3/CNTs nanocomposite increases with the increase of CNTs loading. It is also observed that the degradation temperature (Td) of ENR-FeCl3/CNTs is shifted toward a higher temperature range with the increase of the CNTs loadings.

Introduction: Childhood hypertension is an underestimated problem in India and other developing countries and it often reported in adults. Hypertensive children, although usually asymptomatic, already manifest evidence of target organ damage. Many of hypertensive children have left ventricular hypertrophy and increased carotid intima-media thickness, a marker of early atherosclerosis. Hypertensive children are very prone to develop target organ damage like retinopathy, renal damage, cardiac complications if remains undiagnosed and untreated for long. Other risk factors like cardiovascular disease, diabetes mellitus and hyperlipidaemia must also be looked for in hypertensive children. Aim: To study the prevalence, clinical profile, aetiology of hypertension and to analyse various management protocol, complications, and early outcomes of hypertension in hospitalised children aged between 5-10 years. Materials and Methods: This was a prospective, observational analytical study conducted in the Department of Paediatrics of a tertiary care centre at Ahmedabad, Gujarat, India, from 1st October 2017 to 30th September 2019. Blood pressure was measured by mercury sphygmomanometer using auscultatory method in all admitted patients in Paediatrics Department between the age of 5-10 years as a part of vital monitoring. A total of 103 patients having average systolic blood pressure and/or diastolic blood pressure greater than or equal to 95th percentile for that age, sex and height on three or more occasions were included in the study and their comprehensive details were recorded in prestructured proforma. The outcome was recorded as data in excel sheet and arranged in tables. Results: The prevalence of hypertension was 0.96%. The mean age of the study population was 8 years, and the male:female ratio was 1.09:1. Vomiting was the most common presenting complaint followed by fever and puffiness of eyes. A higher incidence of fever on presentation was due to the associated infective pathology of Central Nervous System (CNS). Pallor was the most common finding on general examination. Neurological deficit was observed in patients with hypertensive encephalopathy and stroke. Overall, 21 (20.38%) patients were in stage 2 hypertension, accounting to hypertensive emergencies, 48 (46.6%) patients with hypertension had an underlying renal disorder, followed by CNS disorder in 47 (45.6%). Amlodipine (26.21%) was the most common drug used in hypertensive patients. Most common complication of the present study was hypertensive retinopathy seen in 14 patients (13.59%). Conclusion: In hospitalised patients, the prevalence of hypertension was 0.96% with a male preponderance. On admission, the most prevalent complaints were vomiting and fever. Pallor and puffiness of eyes were the most common general examination findings, and ascites was the most common systemic examination result. The most common secondary cause of hypertension was renal disease, with acute glomerulonephritis as most prevalent.

Natural rubber with 50 mol % epoxidation (ENR-50) was filled with carbon nanotubes (CNTs) and conductive carbon black (CCB) hybrid fillers with various CCB loadings of 2.5, 5.0, 7.0, 10.0 and 15.0 phr, and the compounds were mixed with ferric ion (Fe3+) as a crosslinking agent. The ENRs filled exclusively with CNTs, and CNT–CCB hybrid fillers exhibited typical curing curves at different CCB loadings, i.e., increasing torque with time and thus crosslinked networks. Furthermore, the incorporation of CNT–CCB hybrid fillers and increasing CCB loadings caused an enhancement of tensile properties (modulus and tensile strength) and crosslink densities, which are indicated by the increasing torque difference and the crosslink densities. The crosslink densities are determined by swelling and temperature scanning stress relaxation (TSSR). Increasing CCB loadings also caused a significant improvement in bound rubber content, filler–rubber interactions, thermal resistance, glass transition temperature (Tg) and electrical conductivity. A combination of 7 phr CNT and CCB with loading higher than 2.5 phr gave superior properties to ENR vulcanizates. Furthermore, the secondary CCB filler contributes to the improvement of CNT dispersion in the ENR matrix by networking the CNT capsules and forming CNT–CCB–CNT pathways and thus strong CNT–CCB networks, indicating the improvement in the tensile properties, bound rubber content and dynamic properties of the ENR composites. Moreover, higher electrical conductivity with a comparatively low percolation threshold of the hybrid composites was found as compared to the ENR filled with CNTs without CCB composite. The superior mechanical and other properties are due to the finer dispersion and even distribution of CNT–CCB hybrid fillers in the ENR matrix.

The preparation of intelligent structures for multiple smart applications such as soft-robotics, artificial limbs, etc., is a rapidly evolving research topic. In the present work, the preparation of a functional fabric, and its integration into a soft elastomeric matrix to develop an adaptive fiber-elastomer composite structure, is presented. Functional fabric, with the implementation of the shape memory effect, was combined with liquid polybutadiene rubber by means of a low-temperature vulcanization process. A detailed investigation on the crosslinking behavior of liquid polybutadiene rubber was performed to develop a rubber formulation that is capable of crosslinking liquid rubber at 75 °C, a temperature that is much lower than the phase transformation temperature of SMA wires (90–110 °C). By utilizing the unique low-temperature crosslinking protocol for liquid polybutadiene rubber, soft intelligent structures containing functional fabric were developed. The adaptive structures were successfully activated by Joule heating. The deformation behavior of the smart structures was experimentally demonstrated by reaching a 120 mm bending distance at an activation voltage of 8 V without an additional load, whereas 90 mm, 70 mm, 65 mm, 57 mm bending distances were achieved with attached weights of 5 g, 10 g, 20 g, 30 g, respectively.

Cell neighbor exchanges are integral to tissue rearrangements in biology, including development and repair. Often, these processes occur via topological T1 transitions analogous to those observed in foams, grains, and colloids. However, in contrast to those in nonliving materials, the T1 transitions in biological tissues are rate limited and cannot occur instantaneously due to the finite time required to remodel complex structures at cell-cell junctions. Here, we study how this rate-limiting process affects the mechanics and collective behavior of cells in a tissue by introducing this important biological constraint in a theoretical vertex-based model as an intrinsic single-cell property. We report that, in the absence of this time constraint, the tissue undergoes a glass transition with lowering of cell motility characterized by a sharp increase in the intermittency of cell-cell rearrangements. Remarkably, this glass transition disappears, as T1 transitions are temporally limited. As a unique consequence of limited rearrangements, we also find that the tissue develops spatially correlated populations of fast and slow cells, in which the fast cells organize into streamlike patterns and maintain optimally stable cell-cell contacts. The predictions of this work are compared with existing in vivo experiments in Drosophila pupal development.

In this work, studies are carried out to understand the crosslinking reaction of epoxidized natural rubber (50 mol% epoxy, ENR-50) by metal ion namely ferric ion (Fe3+, FeCl3, ferric chloride). It is found that a small amount of FeCl3 can cure ENR to a considerable extent. A direct interaction of the ferric ion with the epoxy group as well as internal polymerization enable the ENR to be cured in an efficient manner. It was also found that with the increased concentration of FeCl3, the crosslinking density of the matrix increased and therefore, the ENR offers higher mechanical properties (i.e., modulus and tensile strength). In addition, the glass transition temperature (tg) of ENR vulcanizate is increased with increasing concentration of FeCl3. Moreover, the thermal degradation temperature (Td) of the ENR-FeCl3 compound was shifted toward higher temperature as increasing concentration FeCl3.