Over the last two decades, our understanding of soot formation has evolved from an empirical, phenomenological description to an age of quantitative modeling for at least small fuel compounds. In ...this paper, we review the current state of knowledge of the fundamental sooting processes, including the chemistry of soot precursors, particle nucleation and mass/size growth. The discussion shows that though much progress has been made, critical gaps remain in many areas of our knowledge. We propose the roles of certain aromatic radicals resulting from localized π electron structures in particle nucleation and subsequent mass growth. The existence of these free radicals provides a rational explanation for the strong binding forces needed for forming initial clusters of polycyclic aromatic hydrocarbons. They may also explain a range of currently unexplained sooting phenomena, including the large amount of aliphatics observed in nascent soot formed in laminar premixed flames and the mass growth of soot in the absence of gas-phase H atoms. While the above suggestions are inspired, to an extent, by recent theoretical findings from the materials research community, this paper also demonstrates that the knowledge garnered through our longstanding interest in soot formation may well be carried over to flame synthesis of functional nanomaterials for clean and renewable energy applications. In particular, work on flame-synthesized thin films of nanocrystalline titania illustrates how our combustion knowledge might be useful for developing advanced yet inexpensive thin-film solar cells and chemical sensors for detecting gaseous air pollutants.
Long-term operational stability is the foremost issue delaying the commercialization of perovskite solar cells (PSCs). Here we demonstrate an in-situ cross-linking strategy for operationally stable ...inverted MAPbI
PSCs through the incorporation of a cross-linkable organic small molecule additive trimethylolpropane triacrylate (TMTA) into perovskite films. TMTA can chemically anchor to grain boundaries and then in-situ cross-link to a robust continuous network polymer after thermal treatment, thus enhancing the thermal, water-resisting and light-resisting properties of organic/perovskite films. As a result, the cross-linked PSCs exhibit 590-fold improvement in operational stability, retaining nearly 80% of their initial efficiency after continuous power output for 400 h at maximum power point under full-sun AM 1.5 G illumination of Xenon lamp without any UV-filter. In addition, under moisture or thermal (85 °C) conditions, cross-linked TMTA-based PSCs also show excellent stability with over 90% of their initial or post burn-in efficiency after aging for over 1000 h.
In the past two decades, members of the SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE （SPL） family of transcription factors, first identified in Antirrhinum majus, have emerged as pivotal regulators of ...diverse biological processes in plants, including the timing of vegetative and reproductive phase change, leaf development, tillering/branching, plastochron, panicle/tassel architecture, fruit ripening, fertility, and response to stresses. Transcripts of a subset of SPLs are targeted for cleavage and/or translational repres- sion by microRNA156s （miR156s）. The levels of miR156s are regulated by both endogenous developmental cues and various external stimuli. Accumulating evidence shows that the regulatory circuit around the miR156/SPL module is highly conserved among phylogenetically distinct plant species, and plays impor- tant roles in regulating plant fitness, biomass, and yield. With the expanding knowledge and a mechanistic understanding of their roles and regulatory relationship, we can now harness the miR156/SPL module as a plethora of tools to genetically manipulate crops for optimal parameters in growth and development, and ultimately to maximize yield by intelligent design of crops.
Hydrogels with adhesive properties have potential for numerous biomedical applications. Here, the design of a novel, intrinsically adhesive hydrogel and its use in developing internal therapeutic ...bandages is reported. The design involves incorporation of “triple hydrogen bonding clusters” (THBCs) as side groups into the hydrogel matrix. The THBC through a unique “load sharing” effect and an increase in bond density results in strong adhesions of the hydrogel to a range of surfaces, including glass, plastic, wood, poly(tetrafluoroethylene) (PTFE), stainless steel, and biological tissues, even without any chemical reaction. Using the adhesive hydrogel, tissue‐adhesive bandages are developed for either targeted and sustained release of chemotherapeutic nanodrug for liver cancer treatment, or anchored delivery of pancreatic islets for a potential type 1 diabetes (T1D) cell replacement therapy. Stable adhesion of the bandage inside the body enables almost complete tumor suppression in an orthotopic liver cancer mouse model and ≈1 month diabetes correction in chemically induced diabetic mice.
An adhesive hydrogel based on a “load‐sharing” effect of triple hydrogen bonding clusters is reported. To demonstrate their potential applications, these adhesive hydrogels are engineered into internally applied tissue bandages for delivery of either antitumor drugs directly to the tumor site or insulin‐producing cells to treat type 1 diabetes.
The rapid development of topological photonics and acoustics calls for accurate understanding of band topology in classical waves, which is not yet achieved in many situations. Here, we present the ...Wilson-loop approach for exact numerical calculation of the topological invariants for several photonic/sonic crystals. We demonstrate that these topological photonic/sonic crystals are topological crystalline insulators with fragile topology, a feature which has been ignored in previous studies. We further discuss the bulk-edge correspondence in these systems with emphasis on symmetry broken on the edges.
•COVID-19-induced layoff increases survivors’ COVID-19-related stress.•COVID-19-induced layoff impact survivors’ job performance via COVID-19-related stress.•Social support moderates the impact ...COVID-19-induced layoff on COVID-19-related stress.
The COVID-19 pandemic has hit the hospitality industry hard globally, resulting in millions of employees being laid off. Drawing upon the conservation of resources theory, this study aims to empirically examine how and when COVID-19-induced layoff influences employees’ in-role and extra-role performance in the hospitality industry. We tested this model by using field data collected from 302 employees and their supervisors in China across two waves. Results revealed that COVID-19-induced layoff increases survivors’ COVID-19-related stress, which in turn leads to decreased in-role and extra-role performance. The strength of these indirect effects is mitigated by perceived family support against COVID-19. Unexpectedly, perceived organizational support against COVID-19 intensifies these indirect effects. The theoretical and practical implications of this study are further discussed.
In this study, we aim to explore the link between transformational leadership and job crafting. We predict that transformational leadership will stimulate employee job crafting (seeking resources, ...seeking challenges, and reducing demands) by increasing their adaptability; but that transformational leadership will be less effective when employees have higher levels of organizational identification. We collected data from 185 dyads of subordinates and supervisors. Supervisors rated their own transformational leadership and subordinates' adaptability, and subordinates rated their own job crafting and organizational identification. Results from structural equation modelling analyses partially supported our hypotheses. In general our findings suggest that transformational leadership is associated with more expansion job crafting (seeking resources and seeking challenges) via adaptability, particularly for employees with lower organizational identification. We conclude that transformational leadership is an important antecedent of employee adaptability and proactivity at work.
•The relationship between transformational leadership and job crafting was examined.•Employee adaptability was positioned as a mediator in the above relationship.•The above mediation effect was moderated by employee organizational identification.•Transformational leadership facilitates employee adaptability and proactivity.
Chronic adenoiditis Wang, Hai
Journal of International Medical Research,
11/2020, Volume:
48, Issue:
11
Book Review, Journal Article
Peer reviewed
Open access
In addition to acute adenoiditis and adenoid hypertrophy/vegetation, chronic adenoiditis is another disease of the adenoids. However, most physicians overlook chronic adenoiditis or confuse it with ...adenoid hypertrophy/vegetation. The incidence of chronic adenoiditis has increased in recent years as a result of higher rates of chronic nasopharyngeal or upper airway infections. The clinical characteristics of chronic adenoiditis can include but are not restricted to the following: long-term infection (especially bacterial infection); obstruction of the upper airway; infections of adjacent regions, such as the nose, nasal sinus, pharyngeal space, middle ear, and atlantoaxial joint; induced upper airway cough syndrome; and the presence of several “infectious-immune” diseases, including rheumatic fever, autoimmune nephropathy, and anaphylactoid purpura. To date, no consensus on the treatment of chronic adenoiditis is available. However, adenoidectomy can address the local obstruction, and some patients benefit from systemic or local anti-bacterial therapy. Physicians in the Departments of Otolaryngology, Respiration, and Pediatrics should be familiar with the clinical manifestations of chronic adenoiditis and try to develop effective treatment methods for this disease.
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