Formation Of Chains Research Articles

Using diatom chain length as a bioindicator of heavy-metals contamination in marine environments

The increasing release of toxic heavy metals into marine environments poses significant risks due to their persistence and bioaccumulation. Diatoms are ideal bioindicators because of their sensitivity to environmental changes. Despite traditional methods for detecting these persistent pollutants effectively identify composition and concentration, they are time-consuming, they often require the use of harmful reagents, and do not allow a fast assessment of detrimental impacts on marine organisms. To fill this gap, we have successfully investigated the toxicity of different heavy metals in the marine diatom Skeletonema pseudocostatum thanks to a newly developed high-power terahertz (THz) spectrometer. By combining THz spectroscopy, microscopy and ecotoxicological assays, we found that the formation of long diatom chains is significantly inhibited by the presence of lead, copper, and chromium, which disrupt their metabolism. Although the THz absorption and refractive index spectra were not affected by diatom concentration in undoped samples, THz frequencies were highly sensitive to changes in diatom chain length due to heavy metals exposure. These findings suggest that this approach allows to investigate the biochemical processes involved in chain formation in S. pseudocostatum and related algae. THz spectroscopy could therefore provide deeper insights into the microscopic metabolic activity of diatoms, addressing key biochemical questions surrounding these organisms. Furthermore, we propose this novel approach for environmental pollution monitoring, since it could provide a rapid, harmless and sensitive detection method to assess heavy metal toxicity in marine diatoms, key organisms at the basis of the trophic chain.

Demographics, clinical profiles and healthcare utilization of patients with beta thalassemia major: A single centered study

Thalassemia is an inherited autosomal recessive blood disorder that occurs due to abnormal form of hemoglobin in the blood. It is an autosomal recessive condition caused by decreased formation of alpha or beta chains of hemoglobin. Pakistan continues to suffer from a high thalassemia burden with statistics rising every year. With around 10 million carriers across the country, it is reported that each year, around 5000 children are diagnosed with thalassemia. The aim of this study is to bridge the gap between the problems faced by thalassemic patients in Pakistan and the facilities not available to them as compared to the developed countries. Method: A cross- sectional study was conducted with the duration of this study was 12 months. The data was collected from six tertiary care hospitals and eight Thalassemia centers, with the selection based on the accessibility of data. The inclusion criteria for the study was: a clinical diagnosis of Beta Thalassemia Major and age group between 1-18 years, irrespective of gender. The exclusion criteria included patients who were over 18 years of age and had comorbidities or complications other than Beta Thalassemia Major, as well as those who did not give consent. A questionnaire was circulated to record the data. It had two parts. The first part included demographics and the second part had close-ended questions related to the treatment of Thalassemia. Results: The total number of participants were 255 in which 122 (47.8%) were males and 133 (52.2%) were females. A positive correlation was observed between age and hospital visits, showing that an increase in age was associated with an increase in hospital visits among Beta Thalassemia patients (p value< 0.05) (CL:95%). Positive correlation was observed between the age of patients and the number of Liver Function tests. (p-value<0.05) (CL: 95%), viral profile done per year and age among B-thalassemia major patients. (p-value< 0.05) (CL:95%) and between age and cbc conducted per month (p-value < 0.05). Another positive correlation was observed between weight and frequency of blood transfusions in B-thalassemia major patients (p-value< 0.05) (CL:95%) and weight and liver function tests conducted per year among thalassemia patients. (p-value< 0.05) (CL:95%). Conclusion: This study aims to highlight the problems faced by thalassemia patients in Pakistan and the facilities not available to them compared to developed countries. A cross-sectional study was conducted for 12 months, collecting data from six tertiary care hospitals and eight Thalassemia centers. A questionnaire was used to record data on demographics and close-ended questions related to thalassemia treatment. Positive correlations were observed between age and hospital visits, liver function tests, viral profiles, and CBCs conducted. Weight was positively correlated with the frequency of blood transfusions and liver function tests conducted per year.

Organic Moiety on Sn(IV) Does Matter for In Vitro Mode of Action: nBu3Sn(IV) Compounds with Carboxylato N-Functionalized 2-Quinolones Induce Anoikis-like Cell Death in A375 Cells

Objectives: New tributyltin(IV) complexes containing the carboxylate ligands 3-(4-methyl-2-oxoquinolin-1(2H)-yl)propanoic acid (HL1) and 2-(4-methyl-2-oxoquinolin-1(2H)-yl)acetic acid (HL2) have been synthesized. Methods: Their structures have been determined by elemental microanalysis, FT-IR and multinuclear NMR (1H, 13C and 119Sn) spectroscopy and X-ray diffraction study. A solution state NMR analysis reveals a four-coordinated tributyltin(IV) complex in non-polar solvents, while an X-Ray crystallographic analysis confirms a five-coordinated trigonal-bipyramidal geometry around the tin atom due to the formation of 1D chains. A theoretical structural analysis was performed by optimization employing B3LYP-D3BJ functional and 6-311++G(d,p)/def2-TZVP(Sn) basis sets for H, C, N, O/Sn, respectively. The interactions between tin(IV) and surrounding atoms were examined by QTAIM approach. The in vitro antiproliferative activity of the synthesized compounds was evaluated by MTT and CV assays versus MCF-7 (human breast adenocarcinoma), HCT116 (human colorectal carcinoma), A375 (human melanoma), 4T1 (mouse breast carcinoma), CT26 (mouse colon carcinoma) and B16 (mouse melanoma) tumor cell lines. Results: Both synthesized compounds (nBu3SnL1 and nBu3SnL2) exerted powerful micromolar IC50 cytotoxicity values and demonstrated high selectivity toward malignant cells. Both experimental drugs affected cell adhesion and induced anchorage independent apoptosis, a favorable type of cell death with an essential role in cancer dissemination prevention. The BSA-binding affinity of the obtained organotin compounds was followed by spectrofluorometric titration and molecular docking simulations. Conclusions: The tributyltin(IV) compounds selectively induce anoikis-like cell death in A375 cells, also highlighting the importance of the organic moiety on the tin(IV) ion in the mechanism of action.

Typhoon related cascading fault chain dynamic evolution model and risk mitigation in distribution systems

The resilience of distribution system is severely influenced by typhoon disasters and the secondary disasters such as floods and debris flows. The cascading propagation of typhoon disasters, coupled with the cascading propagation of faults in distribution systems, creates a dual-coupling dynamic that results in large-scale faults. The key to mitigating losses from typhoon-related cascading faults lies in understanding the potential paths of cascading propagation and taking corresponding measures to preemptively interrupt the chain propagation. In this paper, based on the analysis of actual typhoon related fault data of Guangzhou, China, we created the knowledge graph of the typhoon related cascading fault chains and modeled the chain formation mechanism, successfully integrating the distribution systems and the typhoon disaster propagation systems. We also achieved the dynamic evolution of typhoon related cascading fault chains by using system dynamics. In the case studies of Guangzhou, we selected three typical typhoon related fault scenarios, and then the proposed model is utilized to capture the fault cascading pathway, which can help mitigate typhoon related fault risks in distribution systems.

TRIM47 promotes hypopharyngeal and laryngeal cancers progression through promoting K63-linked ubiquitination of vimentin.

Hypopharyngeal and laryngeal cancers which belong to head and neck squamous cell carcinoma (HNSCC) are the two most malignant types of head and neck cancer, characterized by a low 5-year survival rate, high recurrence and metastasis rate. It is vital to explore strategies to suppress metastasis and improve prognosis for patients with these cancers. In this research, we analyzed the clinical data and found that E3 ubiquitin ligase TRIM47 was upregulated in cancer tissues of hypopharyngeal cancer and was closely associated with poor survival outcomes. In terms of mechanism, we performed tandem affinity chromatography and denatured Ni-NTA Agarose pulldown. As a result, TRIM47 was found to interact with vimentin and control vimentin stabilization through ubiquitination, specifically in the form of K63 chains. Importantly, through experiments of cancer cell viability and migration, we found that TRIM47 could enhance the proliferation and metastasis abilities of cancer cells in a vimentin-dependent manner, thus promoting the advancement of hypopharyngeal and laryngeal cancers. TRIM47 was verified to regulate cancer cells metastasis invivo using metastasis models. All these results imply that TRIM47 emerges as a potential biomarker for early diagnosis and metastasis prediction of hypopharyngeal and laryngeal cancers and represents a promising therapeutic target.

STING induces HOIP-mediated synthesis of M1 ubiquitin chains to stimulate NF-κB signaling.

STING activation by cyclic dinucleotides induces IRF3- and NF-κB-mediated gene expression in mammals, as well as lipidation of LC3B at Golgi-related membranes. While mechanisms of the IRF3 response are well understood, the mechanisms of NF-κB activation via STING remain unclear. We report here that STING activation induces linear/M1-linked ubiquitin chain (M1-Ub) formation and recruitment of the LUBAC E3 ligase, HOIP, to LC3B-associated Golgi membranes where ubiquitin is also localized. Loss of HOIP prevents formation of M1-Ub chains and reduces STING-induced NF-κB and IRF3 signaling in human THP1 monocytes and mouse bone marrow-derived macrophages, without affecting STING activation. STING-induced LC3B lipidation is not required for M1-Ub chain formation or for immune-related gene expression, but the recently reported STING function in neutralizing Golgi pH may be involved. Thus, LUBAC synthesis of M1-linked ubiquitin chains mediates STING-induced innateimmune signaling.

The effect of a poly-herbal plant extract on the adhesion of Streptococcus mutans to tooth enamel

BackgroundDental caries, also known as tooth decay or cavity formation, is one of the world’s most widespread dental conditions. It is a plaque-related infection caused mainly by Streptococcus mutans. People have relied on several plant species to treat oral infections; Heteropyxis natalensis, for example, has been used to treat toothache and gum infections.MethodsIn this study, the antimicrobial and anti-adherence properties of H. natalensis and Camellia sinensis, as well as tea tree and peppermint essential oils were investigated on tooth enamel.ResultsThe bacterial load of S. mutans was reduced by approximately two orders of a magnitude after 48 h, with a lesser extent on the commensal bacteria, Lactobacillus paracasei. Scanning electron micrographs of enamel blocks showed a reduction in the attachment and chain formation of S. mutans and degraded cell morphology. Lastly, the combination and each component individually, showed low to no cellular toxicity when tested on human macrophages.ConclusionsThis is the first report of this polyherbal regarding its selectivity and potential prevention of dental caries.

Engineering the orthogonal ubiquitin E1-E2 pairs for identification of K27 chain linkage substrates

Ubiquitination is one kind of crucial protein post-translational modification (PTM) in eukaryotic cells, forming sorts of types of polyubiquitin chain linkages on the substrates. Ubiquitin conjugating enzymes (E2s) play an essential role in the formation of ubiquitin chains. However, the mechanism of the formation of atypical chain (such as K27) and the identification of the related substrates are not well understood. Previously we developed an orthogonal ubiquitin transfer (OUT) pathway to identify the substrates of a specific ubiquitin ligase (E3). In OUT pathway, a ubiquitin mutant (xUb) is transferred to the substrates through an engineered xE1-xE2-xE3 cascade. In this study, we reengineered a new OUT pathway for the transfer of xUb-K27, an isoform of xUb with only one lysine at Lys27 resident. The newly designed xUba1-xUbe2D2 (xE1-xE2) pairs can transfer xUb-K27 to downstream wild type E3s and form K27 linkages. Ube2D2 is known for its versatility as it forms all sorts of polyubiquitin chains on substrates. Therefore, the xE1-xE2 pairs are empowered to transfer other ubiquitin mutants, for instance, xUb-K6 and xUb-K11. The new xE1-xE2 pairs also deepen the understanding of structural information about the E1-E2 interaction, and provide further insights into the mechanism of chain formation mediated by E2.

Analysis of Poly(ethylene glycol) from the conservation of 17th century shipwreck Vasa and associated wooden objects

Vasa, a Swedish warship that sunk in 1628 and was excavated in 1961, and associated wooden objects underwent a preservation process using various low molecular weights (600, 1500, and 4000 Mn) of poly(ethylene glycol) (PEG) to gradually displace the water within the wooden structure, preventing the collapse of the waterlogged wood upon drying. However, after six decades of aging after application, to what extent are these polymers degraded? To investigate this, a Soxhlet apparatus was used to extract PEG from wooden samples of Vasa, and lyophilization was used to dry aqueous PEG solutions, these samples being the runoff accumulated during the application of different molecular weights of PEG to Vasa and other associated wooden objects. These samples underwent analysis via matrix-assisted laser desorption/ionization – time-of-flight mass spectrometry (MALDI-TOF MS), gel permeation chromatography (GPC), and 1H and 13C nuclear magnetic resonance (NMR) spectroscopy.The primary discovery was that the PEG within Vasa exhibited minimal degradation, with the dominant identified species, as determined by MALDI-TOF MS and NMR spectroscopy, being HO-PEG-OH. However, small quantities of HO-PEG-OH had undergone degradation, resulting in the formation of PEG chains with distinct end groups, notably a range of carbonyl-based compounds, including aldehydes, carboxylic acids, and esters, as observed through MALDI-TOF MS, 1H, and 13C NMR spectroscopy. These mass spectrometry product peaks could be confirmed by the expected mass difference through various end-group functionalizations, such as oxidations, esterifications, or ether formations. In addition to the carbonyl-based degradation products, some PEG chains had completely cleaved into two separate lower molecular weight HO-PEG-OH polymers, each approximately half of their original molecular weight, as revealed by GPC analysis.

The physical properties of cluster chains

We explore the kinematics and star formation history of the Scorpius Centaurus (Sco-Cen) OB association following the initial identification of sequential, linearly aligned chains of clusters. Building upon our characterization of the Corona Australis (CrA) chain, we now analyze two additional major cluster chains that exhibit similar characteristics: the Lower Centaurus Crux (LCC) and Upper Scorpius (Upper Sco) chains. All three cluster chains display distinct sequential patterns in 1) the 3D spatial distribution, 2) age, 3) velocity, and 4) mass. The Upper-Sco chain is the most massive and complex cluster chain, possibly consisting of two or more overlapping subchains. We discuss the possible formation of cluster chains and argue for a scenario where feedback from the most massive star formation episode 15 Myr ago initiated the formation of these spatio-temporal cluster sequences. Our results identify cluster chains as a distinct type of stellar structure with well-defined physical properties, formed in environments capable of sustaining stellar feedback over timescales of 5--10 Myr. We find that around 40<!PCT!> of the stellar population in Sco-Cen formed due to triggered star formation, with 35<!PCT!> forming along the three cluster chains. We conclude that cluster chains could be common structures in OB associations, particularly in regions that have similar natal environments as Sco-Cen. Beyond their significance for star formation and stellar feedback, they appear to be promising laboratories for chemical enrichment and the transport of elements from one generation to the next in the same star-forming region.

Liquid metasurface for size-independent detection of microplastics

Microplastics (MPs) are widely distributed in water, soil, and air, drawing a global concern as a cause of chronic diseases and immune system disruption. Though as one of the most promising techniques in MP detection, the surface-enhanced Raman scattering (SERS) is heavily dependent on the distribution of the “hot spots” and the size of MPs, known as “coffee ring effect” and “size effect” respectively, imposing major challenges in the quantitative detection of various sized MPs on conventional SERS substrates. Here we present a self-healing metasurface based on plasmonic nanoparticle (NP) array at the liquid-liquid interface (LLI) and air-liquid interface (ALI). The fluidic nature of the metasurface and the repulsive forces between NPs offer atomic-level flatness and uniform distribution for “hot spots”. Additionally, MPs are dissolved in the oil phase, uniformly enriched in the form of polymer molecular chains on the liquid metasurface, irrespective of the size of the MPs. This molecular dispersity of the dissolved MPs enhances the overlap between the “hot spots” and scattering volume of MPs, significantly improving the intensity and reproducibility of SERS. The sensing platform is successfully applied in trace detections of various MPs (PS, PET, PMMA, and PC), and validated in real samples.

Long-Range Proton Channels Constructed via Hierarchical Peptide Self-Assembly.

The quest to understand and mimic proton translocation mechanisms in natural channels has driven the development of peptide-based artificial channels facilitating efficient proton transport across nanometric membranes. It is demonstrated here that hierarchical peptide self-assembly can form micrometers-long proton nanochannels. The fourfold symmetrical peptide design leverages intermolecular aromatic interactions to align self-assembled cyclic peptide nanotubes, creating hydrophilic nanochannels between them. Titratable amino acid sidechains are positioned adjacent to each other within the channels, enabling the formation of hydrogen-bonded chains upon hydration, and facilitating efficient proton transport. Moreover, these chains are enriched with protons and water molecules by interacting with immobile counter ions introduced into the channels, increasing proton flow density and rate. This system maintains proton transfer rates closely resembling those in natural protein channels over micrometer distances. The functional behavior of these inherently recyclable and biocompatible systems opens the door for their exploitation in diverse applications in energy storage and conversion, biomedicine, and bioelectronics.

Struggling for Design for the Pluriverse in the Global North

This article explores the difficulties of conducting pluriversal design in the Global North. The point of departure is Arturo Escobar’s discussion on design for the pluriverse, which is a critique of modernity and unsustainability. The analysis centers on a project to develop a game to uncover the unsustainability integral to modern commerce, in the form of value chains of products produced in the Global South and consumed in the Global North. The researchers follow and document their experience with the development of the game aimed at sensitizing school students in the Global North to the injustices, resource overuse, and violence integral to value chains. The analysis describes how the intention to apply pluriversal design principles risks being betrayed by the same designers committed to them, because of their embeddedness in modernity. The authors propose two concrete strategies: first, recognizing that activating pluriversal principles will create discomfort in the designers and the design process; second, developing a vision to activate pluriversal principles.

Cerium Oxide‐Armored Composite Latex Particles by Visible Light Emulsion Photopolymerization: From Synthesis to Film Properties

AbstractCerium dioxide (CeO2) has huge potential in many applications ranging from biochemical engineering to the coating industry. Here, the first example of visible light photo‐mediated Pickering emulsion polymerization of (meth)acrylate monomers is reported using CeO2 nanoparticles (NPs) as solid stabilizer. A ω,ω′−dicarboxylic acid diphenyl disulfide photoinitiator is anchored on the surface of the CeO2 NPs and used to initiate the emulsion polymerization of methyl methacrylate (MMA) and of MMA/n‐butyl acrylate (MMA/BA) under visible light leading to CeO2‐armored latexes. Radicals generated upon light irradiation trigger the formation of polymer chains chemically attached to the CeO2 NPs, promoting their subsequent adsorption on the latex surface. The composite films obtained from the CeO2‐armored P(MMA‐co‐BA) latexes exhibit a unique honeycomb nanostructure with the nanoceria located in the walls giving the materials excellent mechanical, anti‐UV, and photocatalytic properties.

1,8-Diazabicyclo[5.4.0]undec-7-ene as Cyclic Ether Electrolyte Polymerization Inhibition for Wide-Temperature-Range High-Rate Lithium-ion Batteries.

1,3-Dioxolane (DOL), with its broad liquid phase temperature window and low Li+-solvent binding energy, stands out as an ideal solvent candidate for the wide-temperature and high-rate electrolytes. Unfortunately, DOL is susceptible to undergo ring-opening polymerization under common lithium salts, which markedly retards the reaction kinetics. This work introduces the organic basic additive 1,8-Diazabicyclo[5.4.0]undec-7-ene (DBU) to effectively suppress the polymerization, thus achieving compatibility between LiFSI, LiDFOB lithium salts, and DOL. Furthermore, density functional theory (DFT) calculations are utilized to elucidate the underlying mechanisms of DOL polymerization and to clarify how DBU inhibits its polymerization. The resulting electrolyte, devoid of polymer chain formation, forms a weak solvation structure rich in anions, which demonstrates rapid ion transport kinetics in the bulk electrolyte and excellent electrochemical stability at the electrolyte-electrode interfaces (EEIs) simultaneously. When applied to the LiFePO4||graphite full cell, it exhibits exceptional wide-temperature and high-rate performance, with specific capacities reaching 101.2 mAh g -1 at room temperature (20 C), 36.9 mAh g-1 at -40 °C (0.5 C), and 118.0 mAh g-1 at 60 °C (20 C). This study significantly guides the development of wide-temperature, high-rate electrolytes.

Structural Effect of N-7 Alkylation in 6-Chloropurine on Cu (II) Binding: Effect of Anions and Magnetic Studies.

This study investigates the anion-directed assembly of discrete copper (II) complexes. The ligands of choice are two N7-alkyl-purine-based neutral ligands. These ligands facilitate the exclusive coordination through the N3 and N9 positions, preventing polymeric chain formation. Perchlorate ions promoted the formation of discrete paddlewheel-like complexes with the general formula [Cu2(μ-Pur)4(CH3CN)2]4+, while chloride ions yielded chloride-bridged dimers of the form [Cu2(Pur)2(μ-Cl)2Cl2]. Copper-copper bond distances within these complexes ranged from 2.92 to 2.98 Å. Magnetic susceptibility measurement of chloride-bridged complexes exhibited antiferromagnetic coupling, whereas paddlewheel complexes displayed more complex alternating ferromagnetic and antiferromagnetic interactions. Chloride-bridged compounds exhibited strong near-infrared absorption.

The essence and characteristics of global value chains: theoretical aspect

The article carries out a comparative analysis of scientific approaches to understanding the essence of global value chains, as a result of which the author’s position on this issue is substantiated. It has been established that the territorial organization of international business and the international division of labor form the conceptual basis of the formation of global value chains. Special attention is paid to how processes of global economic integration contribute to constant modifications of value chains, as well as the importance of their effective management, which is a decisive factor in increasing the competitiveness of companies and countries. The article argues that participation in global value chains provides businesses and governments with significant benefits, such as access to new markets, increased production efficiency, and increased value added. At the same time, risks have been identified, in particular those related to the instability of supply chains, increased competition and dependence on global markets. Different types of global value chains and features of their management in the conditions of modern challenges of globalization are considered. Conclusions have been made regarding the prospects for the development of Ukrainian business based on the concept of global value chains, taking into account global trends and national features of the economy. The article is useful for scientists, specialists in the field of international business and economics, as well as for those who are interested in the integration of national economies into global production processes. A comparative analysis of the positions of modern scientists regarding the essence of global value chains was carried out. Reasoned author’s position on the issue of the essence of global value chains. It has been established that the territorial organization of international business, as well as the international division of labor, is the conceptual basis for the formation of global value chains. It is argued that in the conditions of strengthening integration processes in the global economy, constant modifications of global value chains take place, and their management becomes one of the important factors of competitiveness. The benefits that business units and countries receive from participating in global value chains are determined, and the associated risks are also identified. The typology of global value chains, features of their management are analyzed. Conclusions have been made regarding the prospects for domestic business development based on the concept of global value chains.

Experimental Verification of a Compressor Drive Simulation Model to Minimize Dangerous Vibrations

The article highlights the importance of analytical computational models of torsionally oscillating systems and their simulation for estimating the lowest resonance frequencies. It also identifies the pitfalls of the application of these models in terms of the accuracy of their outputs. The aim of the paper is to control the dangerous vibration of a mechanical system actuator using a pneumatic elastic coupling using different approaches such as analytical calculations, experimental measurement results, and simulation models. Based on the known mechanical properties of the laboratory system, its dynamic model in the form of a twelve-mass chain torsionally oscillating mechanical system is developed. Subsequently, the model is reduced to a two-mass system using the method of partial frequencies according to Rivin. The total load torque of the piston compressor under fault-free and fault conditions is simulated to obtain the amplitudes and phases of the harmonic components of the dynamic torque. After calculating the natural frequency and the natural shape of the oscillation, the Campbell diagram is processed to determine the critical revolutions. There is a pneumatic flexible coupling between the rotating masses, which changes the dynamic torsional stiffness. The dynamic torque curves transmitted by the coupling are compared with different dynamic torsional stiffnesses during steady-state operation and one cylinder failure. The monitored values are the position of the critical revolutions, the natural frequency, the natural shape of the oscillation, and the RMS of the dynamic load torque. The experimental model is verified by the simulation model. The accuracy of the developed simulation model with the experimental data are apparently very good (even more than 99% of the critical revolutions value obtained by calculation); however, it depends on the dynamic stiffness of the coupling. In this study, a detailed, comprehensive approach combining analytical procedures with simulation models is presented. Experimental data are verified with simulation results, which show a good agreement in the case of 700 kPa coupling pressure. The inaccuracy of some of the experiments (at 300 and 500 kPa pressures) is due to the interaction of the coupling’s apparent stiffness and the level of the damped vibration energy in the coupling, which is manifested by its different heating. Based on further experiments, a solution to these problems will be proposed by introducing this phenomenon effectively into the simulation model.

Ferrofluid Droplet Chains in Thermotropic Nematic Liquid Crystals.

Dispersing ferrofluids in liquid crystals (LCs) produces unique systems which possess magnetic functionality and novel phenomena such as droplet chaining. This work reports the formation of ferrofluid droplet chains facilitated by the topological defects within the LC director field, induced by the dispersed ferrofluid. The translational and rotational motion of these chains could be controlled via application of external magnetic fields. The process of the droplet chain formation in LCs can be stabilized by the addition of surfactants. The magnetic colloidal particles in the ferrofluid located at the interface between the ferrofluid and the LC are arranged so that a boundary layer was formed. The velocities and boundary layer thickness values of ferrofluid droplet chains in nematic 5CB (4-Cyano-4'-pentylbiphenyl) were investigated for varying average droplet sizes and number of droplets in a chain. The creation and behaviour of ferrofluid droplet chains in 5CB with the addition of the surfactant polysorbate 60 (Tween-60) and without, was comparatively investigated. The integration of liquid crystals and ferrofluids along with the incorporation of functional materials facilitates the innovative development of advanced materials for future applications.

Chelerythrine triggers the prolongation of QT interval and induces cardiotoxicity by promoting the degradation of hERG channels

Cardiotoxicity is a serious adverse reaction during drug treatment. The cardiac hERG channels play a crucial role in driving cardiac action potential repolarization and are a key target for drug-induced cardiac toxicity. Chelerythrine has anti-cancer effects on various human cancer cells. But little is known about its drug safety currently. The purpose of this study is to explore the key mechanism of cardiac toxicity induced by Chelerythrine under pathological conditions. Chelerythrine and hypoxia prolonged QT interval and action potential duration compared with control group in guinea pigs, as measured by BL-420S biological acquisition and processing system in conjunction with optical mapping technology. HERG current was measured by patch-clamp technique and the interaction between ubiquitin molecules and hERG channels was assessed using immunoprecipitation method at the molecular level. The co-localization of proteins and the function of lysosomes were determined via confocal laser scanning microscopy. Further research indicates that Chelerythrine enhances the ubiquitination process of hERG proteins by catalyzing the formation of K63 ubiquitin chains, the ubiquitination modification disrupts hERG channel homeostasis and promotes the degradation of the channel. Mechanistically, Chelerythrine accelerates the degradation of hERG channels through lysosomes via HDAC6, which may easily induce cardiotoxicity caused by prolonged QT interval under hypoxic conditions.