The field of organic electronics thrives on the hope of enabling low‐cost, solution‐processed electronic devices with mechanical, optoelectronic, and chemical properties not available from inorganic ...semiconductors. A key to the success of these aspirations is the ability to controllably dope organic semiconductors with high spatial resolution. Here, recent progress in molecular doping of organic semiconductors is summarized, with an emphasis on solution‐processed p‐type doped polymeric semiconductors. Highlighted topics include how solution‐processing techniques can control the distribution, diffusion, and density of dopants within the organic semiconductor, and, in turn, affect the electronic properties of the material. Research in these areas has recently intensified, thanks to advances in chemical synthesis, improved understanding of charged states in organic materials, and a focus on relating fabrication techniques to morphology. Significant disorder in these systems, along with complex interactions between doping and film morphology, is often responsible for charge trapping and low doping efficiency. However, the strong coupling between doping, solubility, and morphology can be harnessed to control crystallinity, create doping gradients, and pattern polymers. These breakthroughs suggest a role for molecular doping not only in device function but also in fabrication—applications beyond those directly analogous to inorganic doping.
Strong interactions between molecular dopants and organic semiconductor morphology are often responsible for charge trapping and low doping efficiency. This study reviews how solution‐processing techniques can control these interactions and render them useful for engineering diffusion rates, doping gradients, and film topography. These breakthroughs suggest new roles for molecular doping in device fabrication as well as function.
Encapsulating a drug molecule into a water‐reactive metal–organic framework (MOF) leads to amorphous drug confined within the nanoscale pores. Rapid release of drug occurs upon hydrolytic ...decomposition of MOF in dissolution media. Application to improve dissolution and solubility for the hydrophobic small drug molecules curcumin, sulindac, and triamterene is demonstrated. The drug@MOF composites exhibit significantly enhanced dissolution and achieves high supersaturation in simulated gastric and/or phosphate buffer saline media. This combination strategy where MOF inhibits crystallization of the amorphous phase and then releases drug upon MOF irreversible structural collapse represents a novel and generalizable approach for drug delivery of poorly soluble compounds while overcoming the traditional weakness of amorphous drug delivery: physical instability of the amorphous form.
MOF carrier: A drug delivery strategy where a metal–organic framework inhibits crystallization of the amorphous drug phase and then releases the drug upon hydrolytic decomposition represents a novel approach for delivery of poorly soluble compounds while overcoming the traditional weakness of amorphous drug delivery: physical instability of the amorphous form.
Nanofibers (NFs) of the prototype conjugated polymer, poly(3-hexylthiophene) (P3HT), displaying H- and J-aggregate character are studied using temperature- and pressure-dependent photoluminescence ...(PL) spectroscopy. Single J-aggregate NF spectra show a decrease of the 0–0/0–1 vibronic intensity ratio from ∼2.0 at 300 K to ∼1.3 at 4 K. Temperature-dependent PL line shape parameters (i.e., 0–0 energies and 0–0/0–1 intensity ratios) undergo an abrupt change in the range of ∼110130 K suggesting a change in NF chain packing. Pressure-dependent PL lifetimes also show increased contributions from an instrument-limited decay component which is attributed to greater torsional disorder of the P3HT backbone upon decreasing NF volume. It is proposed that the P3HT alkyl side groups change their packing arrangement from a type I to type II configuration causing a decrease in J-aggregate character (lower intrachain order) in both temperature- and pressure-dependent PL spectra. Chain packing dependent exciton and polaron relaxation and recombination dynamics in NF aggregates are next studied using transient absorption spectroscopy (TAS). TAS data reveal faster polaron recombination dynamics in H-type P3HT NFs indicative of interchain delocalization whereas J-type NFs exhibit delayed recombination suggesting that polarons (in addition to excitons) are more delocalized along individual chains. Both time-resolved and steady-state spectra confirm that excitons and polarons in J-type NFs are predominantly intrachain in nature that can acquire interchain character with small structural (chain packing) perturbations.
Focusing on developed countries, I present a model explaining how firms help determine rates of income inequality at the societal level. I propose that the manner in which firms reward individuals ...for their labor, how they match individuals to jobs, and where they place their boundaries contribute to levels of income inequality in a society. I argue that the determinant of these three processes is due, in part, to the effect of systems of corporate governance on the power and influence of different organizational stakeholders, resulting in variance in the types of employment relationships that predominate in a society. I conclude with a discussion of the research implications of emphasizing employers and employment practices as key determinants of societal-level income inequality.
About the Authors: Judith Olejnik Affiliations Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America, National Emerging Infectious Diseases ...Laboratories, Boston University, Boston, Massachusetts, United States of America Adam J. Hume Affiliations Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America, National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, United States of America Elke Mühlberger * E-mail: muehlber@bu.edu Affiliations Department of Microbiology, Boston University School of Medicine, Boston, Massachusetts, United States of America, National Emerging Infectious Diseases Laboratories, Boston University, Boston, Massachusetts, United States of America ORCID logo http://orcid.org/0000-0003-3547-9376 Citation: Olejnik J, Hume AJ, Mühlberger E (2018) Toll-like receptor 4 in acute viral infection: Activation of TLR4 results in the recruitment of the intracellular adaptor protein, myeloid differentiation primary response 88 (MyD88), and/or toll/interleukin-1 receptor (TIR)-domain-containing adapter-inducing interferon-β (TRIF), ultimately resulting in the expression and secretion of pro-inflammatory mediators 6, 7. ...shed glycoprotein was detected at high levels in EBOV-infected guinea pigs, particularly shortly before death 34. Respiratory syncytial virus fusion protein-induced toll-like receptor 4 (TLR4) signaling is inhibited by the TLR4 antagonists Rhodobacter sphaeroides lipopolysaccharide and eritoran (E5564) and requires direct interaction with MD-2.
Recent Advances in Azaborine Chemistry Campbell, Patrick G.; Marwitz, Adam J. V.; Liu, Shih-Yuan
Angewandte Chemie (International ed.),
June 18, 2012, Letnik:
51, Številka:
25
Journal Article
Recenzirano
Odprti dostop
The chemistry of organoboron compounds has been primarily dominated by their use as powerful reagents in synthetic organic chemistry. Recently, the incorporation of boron as part of a functional ...target structure has emerged as a useful way to generate diversity in organic compounds. A commonly applied strategy is the replacement of a CC unit with its isoelectronic BN unit. In particular, the BN/CC isosterism of the ubiquitous arene motif has undergone a renaissance in the past decade. The parent molecule of the 1,2‐dihydro‐1,2‐azaborine family has now been isolated. New mono‐ and polycyclic B,N heterocycles have been synthesized for potential use in biomedical and materials science applications. This review is a tribute to Dewar’s first synthesis of a monocyclic 1,2‐dihydro‐1,2‐azaborine 50 years ago and discusses recent advances in the synthesis and characterization of heterocycles that contain carbon, boron, and nitrogen.
Ring around the boron: The BN/CC isosterism of arenes, which results in azaborine structures, has emerged as a viable strategy to increase the range of compounds relevant to biomedical research and materials science. As a tribute to Dewar's first synthesis of a monocyclic 1,2‐azaborine 50 years ago, this review summarizes recent advances in the synthesis and characterization of carbon(C)–boron(B)–nitrogen(N)‐containing heteroaromatics.
Industrial Applications of Ionic Liquids Greer, Adam J; Jacquemin, Johan; Hardacre, Christopher
Molecules (Basel, Switzerland),
11/2020, Letnik:
25, Številka:
21
Journal Article
Recenzirano
Odprti dostop
Since their conception, ionic liquids (ILs) have been investigated for an extensive range of applications including in solvent chemistry, catalysis, and electrochemistry. This is due to their ...designation as designer solvents, whereby the physiochemical properties of an IL can be tuned for specific applications. This has led to significant research activity both by academia and industry from the 1990s, accelerating research in many fields and leading to the filing of numerous patents. However, while ILs have received great interest in the patent literature, only a limited number of processes are known to have been commercialised. This review aims to provide a perspective on the successful commercialisation of IL-based processes, to date, and the advantages and disadvantages associated with the use of ILs in industry.
The past eight years of research has demonstrated that oxytocin nasal spray has a significant impact on human social cognition. The aim of this review is to provide critical comment on the literature ...using an information-processing framework. We provide a summary of fundamental assumptions of information-processing models and highlight an impressive range of consistent findings that demonstrate the impact of oxytocin nasal spray on social information processing. These findings include that oxytocin nasal spray improves the early conceptual detection of affect from social cues and improves the accurate appraisal of affect from social cues at elaborate and strategic levels of processing. There is some evidence that these effects may be particularly powerful for positive social cues. This review comments on inconsistent results that have been reported. We argue that such inconsistencies can, in part, be explained by variability across experiments in the degree to which potential extraneous confounds have been controlled, the different methods upon which studies assessed cognition, and the extent to which the focus of investigation has been on group-based outcomes. Finally, we argue that sound cognitive experimental methods can provide powerful tools to identify markers of response to oxytocin nasal spray that can be integrated into more complex circuitry models. The identification of robust markers has particular value in predicting behavioral and therapeutic response to intervention. This should now be a major focus for future research. This article is part of a Special Issue entitled Oxytocin, Vasopressin, and Social Behavior.
► Oxytocin nasal spray impressively impacts on social cognition. ► It improves the early detection of affect from social cues, particularly positive social cues. ► It improves the accurate appraisal of affect from social cues at strategic levels of processing. ► Cognitive experimental methods may provide powerful tools to identify markers of response. ► These markers have value in predicting individual behavioral and therapeutic response.
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