1,722,579 research outputs found
The Last Days of Shi Yang
Full text linkWhat follows is a fictionalised account of the last days of Shi Yang (1889-1923) based on the prison diaries included in the commemorative volume Shi Yang jinian wenji (Museum of the 7 February Massacre, Wuhan 1988). Shi Yang was a weiquan lawyer ante litteram, and to this day he remains an inspiration to many labour activists in China. The Chinese Communist Party (CCP) celebrates him as a martyr of the revolution, the irony of which will not escape those who are aware of the plight of human rights lawyers and labour activists in the country today. That in April 2018 the Chinese government passed a new law to protect the reputation and honour of 'its' heroes and martyrs can be seen as further adding to the irony
Diverse epigenetic mechanisms of human disease
No full textEpigenetic control of gene expression programs is essential for normal organismal development and cellular function. Abrogation of epigenetic regulation is seen in many human diseases, including cancer and neuropsychiatric disorders, where it can affect disease etiology and progression. Abnormal epigenetic profiles can serve as biomarkers of disease states and predictors of disease outcomes. Therefore, epigenetics is a key area of clinical investigation in diagnosis, prognosis, and treatment. In this review, we give an overarching view of epigenetic mechanisms of human disease. Genetic mutations in genes that encode chromatin regulators can cause monogenic disease or are incriminated in polygenic, multifactorial diseases. Environmental stresses can also impact directly on chromatin regulation, and these changes can increase the risk of, or directly cause, disease. Finally, emerging evidence suggests that exposure to environmental stresses in older generations may predispose subsequent generations to disease in a manner that involves the transgenerational inheritance of epigenetic information
Liquid Metal Particles and Polymers: A Soft–Soft System with Exciting Properties
No full textConspectus Gallium-based liquid metal alloys are a special type of material that is in the liquid state at (or near) room temperature. They are particularly attractive due to their unique combination of a fluidic and metallic body, together with a chemically reactive and functionable surface. As a fluid, liquid metals provide the best union of stretchability, deformability, and electrical conductivity among all soft materials. Such an advantage in combination with their low toxicity and relatively good biocompatibility have imparted liquid metals with unique features that can be harnessed for versatile applications in fields such as electronics, energy, chemistry, and biomedical research. More importantly, the fluidic nature of liquid metals allows them to be readily processed using shear for making particles with variable sizes (from nm to mm), which is not possible with solid materials. These particles have a liquid metal core-solid metal oxide shell (conductor-semiconductor) structure, allowing them to merge, transform shape, change phase, respond to stimuli, and self-heal.Despite these unique features, limited surface stability and functionality, unpredictable reactivity, and uncontrollable hydrophilicity of liquid metal particles niche their wider applications in biomedical fields. To bestow liquid metal particles with desirable surface properties while taking the benefits offered by soft features, another important soft material-polymers-can be synthesized and engineered on an on-demand basis to coat or embed liquid metal particles. This leads to the formation of liquid metal-polymer soft composites with versatile surface properties. More specifically, polymer segments with corresponding functions for surface anchoring, tuning solubility, enhancing biocompatibility, providing stimuli-responsive properties, and further bioconjugation can be linked together, thereby forming macromolecules to graft liquid metal particles for yielding soft-soft systems with exciting properties.Herein, we provide a concise review of our contributions to the production, investigation, characterization, and application of liquid metal particle-polymer composites. First, we summarize various top-down techniques developed for producing micro- to nanosized liquid metal particles. We highlight two platforms we developed for tackling long-existing problems encountered by sonication-the most widely adopted method for producing liquid metal particles. Second, we discuss the design of polymers for surface modification of particles. Various grafting strategies for polymers synthesized using different approaches are elaborated. We also discuss factors that affect the colloidal and chemical stability of the composite in biological buffers. Methods for further surface functionalization of the composite are presented, followed by providing examples of biomedical and sensing applications for the system. Next, we introduce the fabrication, unique properties, and applications of elastomeric hybrid composites incorporating liquid metal particle fillers. Finally, we offer a perspective on the opportunities and challenges for the future development of this exciting soft-soft system for realizing synergistic outcomes.</p
Liquid metals as soft electromechanical actuators
No full textLeveraging the unique properties of liquids, such as surface tension, capillary action, reconfigurability, nearly unlimited stretchability, and viscosity has enabled the development of a wide range of soft actuators, presenting vast potential to revolutionise wearable healthcare devices, manufacturing, reconfigurable electronics, and robotics. Gallium (Ga) based liquid metals (GaLMs) are a remarkable family of functional fluidic materials that can actuate electrically for realising electromechanical functions. Such actuators are simple, highly responsive, highly controllable, and reversible, which has led to the creation of useful devices such as reconfigurable antennas, artificial muscles, electrical switches, and soft robots, just to name a few. Herein, this review succinctly and critically summarises recent advances in research on using GaLMs as electromechanical actuators. First, the properties of GaLMs are introduced, and then the methods for their electrical actuation and the applications thereof are discussed. Finally, an outlook is offered, highlighting the research challenges faced by liquid metal electromechanical actuators in order to develop into commercial devices. </p
Liquid Metal Enabled Biodevices
No full textBiodevices are crucial for monitoring vital physiological signals, managing chronic health conditions, developing artificial organs for assisting people with disabilities, and conducting various clinical and surgical procedures. However, existing biodevices are mostly composed of rigid components, which can cause discomfort to the user, whereas the high stiffness of implants is known to be the major cause of inflammation and scarring. Gallium‐based liquid metals are intrinsically soft and possess desirable properties, including low toxicity, high conductivity, and deformability, which make them ideally suited for developing soft, deformable, reconfigurable, and healable biodevices. Herein, recent advancements in the emerging field of liquid‐metal‐based biodevices are discussed. This includes a description of the properties of gallium‐based liquid metals which make them so distinct from conventional materials, a brief outline of various techniques devised for fabrication of liquid‐metal‐based devices/structures, and an overview of the diverse range of wearable or implantable liquid‐metal‐enabled biodevices. The outlook and challenges are also discussed
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Membranous sheath of a fan worm functions as a high-performance energy absorber and stabilizer
No full textMultilayered structure at the macroscale is a prevailing pathway for developing high-performance energy absorbers. Nowadays, most multilayer-structure-based energy absorbers are constructed with rigid materials, but research on utilizing soft materials as energy-absorbing devices is still rare. By understanding the function of membranous sheathes in the stimuli responsiveness of fan worms (Polychaeta: Sabellastarte australiensis), in this work, we report a robust biological energy absorber made of multilayer-structured soft material. Our study reveals that structural features govern the mechanical performance and the energy-absorption capacity of this soft energy absorber. Ultimately, through kinematic analysis of fan worms, we elucidate the advantage of soft-material-based energy absorbers in stabilizing assistance compared with rigid counterparts. Our work takes a significant step toward understanding the design principle of soft-material-based energy absorbers and may shed light on flexible protective devices for soft robotics.</p
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