bluuebunny/crossref_metadata_2025_split huggingface dataset:
Supramolecular Chemistry in
In Vitro
Biosensors
Authors: Sun Jing , Cai Min , Lavigne John J. 
Published: February 2012

Abstract

Supramolecular chemistry has greatly impacted the development of biosensors for use
in vitro
. On the one hand, supramolecular materials can be used as the recognition elements or transducers in these biosensors. On the other hand, the supramolecular interactions between a host and a guest are fundamental in defining the recognition, and can be utilized to develop new sensing mechanisms or improve sensor performance. This chapter focuses on sensing motifs and sensing platforms used
in vitro
for the detection of biologically relevant targets. The highlighted biosensors are based on small molecules, polymers, and biological molecule‐nanomaterial hybrids. Detection methods presented herein primarily focus on optical, electrochemical, or mass‐sensitive modes.
Supramolecular Chemistry in Biological ImagingIn Vivo
Authors: Schultz‐Sikma Elise A. , Meade Thomas J. 
Published: February 2012

AbstractBiological imaging techniques, including magnetic resonance, optical, nuclear, and ultrasound, can be valuable tools for noninvasively studying biochemical processes at the molecular level. This branch of imaging is referred to as molecular imaging. A main challenge in the field ofin vivomolecular imaging is that existing probes limit clinical applications because of their inadequate sensitivity, specificity, and targeting efficiency. Supramolecular chemistry may provide a viable solution to some of these issues. Supramolecular chemical processes involve molecular components assembled into a single, large entity via noncovalent intermolecular forces. The supramolecular concepts of host–guest interaction and self‐assembly have been widely used in the development of more specialized imaging probes forin vivoimaging. This chapter discusses how supramolecular chemistry has been used to design contrast agents with improved signal amplification and specificity for each of the different imaging modalities. Particular attention is focused on magnetic resonance imaging (MRI). Multimodal probes that have benefited from supramolecular chemistry are discussed.
Supramolecular Approaches for Inhibition of Protein–Protein and Protein–
DNA
Interactions
Authors: Battle Cooper H. , Jayawickramarajah Janarthanan 
Published: February 2012

Abstract
The disruption of protein–protein and protein–DNA interactions is increasingly being realized as important avenues for therapeutic intervention. Unlike the successes observed in the more mature field of small molecule derived active site antagonists, however, the sequestration of the sizeable, solvent exposed, and largely featureless protein surfaces remains a significant challenge. This chapter will provide a detailed account of the types of novel inhibitors being developed that address this challenge, with special emphasis given to supramolecular approaches. Indeed, while still in its infancy, the field of aqueous supramolecular chemistry has made great strides in the development of both covalent and self‐assembled multivalent scaffolds for use in protein surface binding. While the former can provide rigid covalent scaffolds tailored for multivalent binding, the latter has the added benefit of being dynamic and thereby can rapidly lead to protein binders that allow for template‐driven elucidation, are stimuli‐responsive, and able to project heteromeric recognition elements. Taken together, these properties give supramolecular inhibitors the potential for exciting future applications in the disruption of protein interactions.
Supramolecular Systems for Tissue Engineering
Authors: Andukuri Adinarayana , Vines Jeremy B. , Anderson Joel M. , Jun Ho‐Wook 
Published: February 2012

AbstractTissue engineering is a combination of engineering, material methods, and life sciences. One of the major challenges of developing tissues is to create a balance between biological and structural entities. Supramolecular systems, more specifically peptide‐based systems, provide a bottom‐up self‐assembling structure that resembles the native hierarchical organization of tissues. This chapter discusses in detail the use of certain supramolecular systems to aid in the engineering of different tissues, namely cardiovascular tissues, bone, dental, pancreas, neural, liver, and cartilage. Detailed examples are provided for each tissue system to show the potential of peptide‐based supramolecular systems in aiding and developing the field of tissue engineering.
Chemical Biology Using Fluorinated Building Blocks
Authors: Zamora Cristina Y. , Dafik Laila , Kumar Krishna 
Published: February 2012

AbstractThere is a long and rich history of the use of fluorine‐containing molecules to modulate biological function. In recent years, incorporation of fluorine atoms into biomolecular assemblies has resulted in unprecedented control of structure and function. The electronegativity of fluorine has helped unveil the physical basis for the stability of collagen; incorporation of trifluoromethyl groups into peptides and proteins has resulted in hyperstable ensembles and enabled the control of oligomer formation in the nonpolar context of biological membranes. Further, fluorinated lipids segregate from hydrocarbon lipids with identical headgroups in bilayers and serve as better vehicles for transporting macromolecular cargo into living cells. Some select systems are highlighted here and the important role of fluorinated biomolecules is discussed.
Advances in Supramolecular Chemistry of Carbon Nanotubes
Authors: Kotchey Gregg P. , Star Alexander 
Published: February 2012

Abstract
In this chapter, the supramolecular chemistry of carbon nanotubes (CNTs) is examined. CNTs are classified as one‐dimensional allotropes of carbon that are endowed with unique physical/mechanical, electronic, and spectral properties. These properties make CNTs attractive for various applications. To be employed for these uses, CNTs must be functionalized, which can occur by either covalent or noncovalent means. During covalent modification, the sidewalls or the end groups are subject to functionalization; the primary problem with this approach, however, is that the physical properties of the nanotube are impaired. In order to chemically modify CNTs while preserving their physical properties, noncovalent functionalization of CNTs needs to be implemented. Examples of supramolecular chemistry of CNTs include: (i) π–π stacking of aromatic compounds to the walls of CNTs, (ii) dispersing CNTs with surfactants, and (iii) polymer wrapping around a CNT. Once functionalized, CNTs can be employed in applications including supramolecular assembly, using CNTs as atomic force microscope (AFM) probes, biorecognition, polymer reinforcement, recognition layers for chemical and biological sensing based on conductivity and fluorescence, the separation of nanotubes, and the use of CNTs for intercellular drug delivery.
One‐Dimensional Nanostructures of Molecular Graphenes
Authors: Zhang Wei , Fukushima Takanori , Aida Takuzo 
Published: February 2012

Abstract

Graphene, a 2D honeycomb network of sp
2
‐hybrized carbon atoms, attracts considerable attention in many research fields because of its extraordinary mechanical and electronic properties. Despite such superb aspects originating from extended π‐conjugation, graphene is not easy to handle, process, and modify. Hence, chemists have been motivated to develop its analog that are able to avoid such problems. Hexabenzocoronene derivatives, which have been named “molecular graphene,” are one of the representatives of such structural analogues. They consist of 13 fused benzene rings and are readily available by oxidative cyclization of hexaarylbenzene derivatives. The development of this synthetic protocol has made it possible to design “soft organic graphite” by supramolecular chemistry. As expected from the π‐stacked architecture of graphite, such graphite‐like organic materials, formed by the assembly of molecular graphenes, display interesting properties such as anisotropic charge carrier transport. This chapter describes the historical background of the synthesis of molecular graphenes and highlights fabrication and properties of their one‐dimensionally assembled nanostructures with fibrous and tubular morphologies.
Nanoelectronics
Authors: McClenaghan Nathan D. , Ducrot Aurélien 
Published: February 2012

AbstractNanoelectronics concerns processing, transmitting, and storing information, as well as switching at the single‐molecule level, often by taking advantage of properties of matter that are distinctly different than those of macroscopic/bulk properties. Strategies, architectures, and materials considered are typically different than those based on “top‐down” CMOS technologies favored in microelectronics, potentially offering an alternative or hybrid technology from a “bottom‐up” approach. In the current overview, particular emphasis is paid to disruptive technologies that are based on molecular, rather than atomic, systems and cases where supramolecular materials, including biological materials, carbon‐based nanomaterials and nanotubes, coordination and conjugated polymers, and molecular machines, are employed and have already started to find application. Equally, the role of noncovalent interactions (π–π stacking, hydrogen‐bonding, electrostatic interactions) in templating, patterning, and nanolithography as well as determining device performance in organic field‐effect transistors, organic photovoltaic devices, and organic light‐emitting diodes is considered. Apparent limitations and perspectives for device development are highlighted in this chapter.
Nanolithography
Authors: Leggett Graham J. 
Published: February 2012

Abstract
A wide range of strategies is now available for organizing molecules at nanometer length scales. Photolithography is the paradigmatic semiconductor processing methodology. We examine the limits on its resolution, and the methods that can be used to enhance its performance. Electron beam lithography offers ultimate resolution; while it requires access to expensive and complex apparatus, it has some significant applications in molecular patterning at small length scales. Soft lithography does not offer such high resolution, but such is its versatility and simplicity that it has become an invaluable tool in supramolecular science. Nanoimprinting and colloidal lithography offer alternate approaches to the physical deposition and removal of material at high resolution. The most widely used scanning probe lithography technique to date has been dip‐pen nanolithography. A wide range of molecules may be patterned on different substrates, and parallelization is now enabling the fast patterning of large areas. Nanoshaving/nanografting represents an opposite approach, involving the selective removal of materials from monolayers. Constructive nanolithography uses a localized tip‐induced oxidation to modify the chemistry of a monolayer, enabling the construction of complex molecular films. Finally, scanning near‐field photolithography uses a near‐field probe to initiate nanometer‐scale photochemical transformations of molecular structure.
Nanotechnology: The “Top‐Down” and “Bottom‐Up” Approaches
Authors: Iqbal Parvez , Preece Jon A. , Mendes Paula M. 
Published: February 2012

Abstract
Nanotechnology has grown at an enormous rate for the past three decades, and recent advances in nanostructured materials and nanodevices have opened up new opportunities in a variety of applications, ranging from information and communication technology to healthcare and medicine. Herein, an overview of nanotechnology is given, describing the origins of the field, present technology, ongoing research, and future aspirations. In addition, the two possible methodologies of fabrication—the top‐down and bottom‐up approaches—are discussed, covering the merits and drawbacks of each approach. As an example of a top‐down procedure, the fabrication of electronic integrated circuits and the foreseen limitations of the procedure for further miniaturization are described. The bottom‐up approach, through self‐assembly and supramolecular chemistry, provides an exciting alternative route either combined with the top‐down approach or on its own.
Self‐Assembled Nanoparticles
Authors: O'Reilly Rachel K. 
Published: February 2012

Abstract
Supramolecular self‐assembly techniques have provided a versatile means by which to selectively assemble polymeric molecules into well‐defined three‐dimensional nanostructures. The stabilization and tailoring of these dynamic nanostructures can be achieved using a range of chemistries to afford functional robust nanoparticles. In this review, we highlight the current techniques and science toward the application of aqueous self‐assembly techniques for the synthesis of polymer nanostructures. There are two main aspects addressed within this review, the first being the synthesis of spherical particles (with a focus on micelles and vesicles) and second the current literature state of the art for the preparation of anisotropic particles.
Supramolecular Hybrid Nanomaterials As Prospective Sensing Platforms
Authors: Biyikal Mustafa , Hecht Mandy , Martínez‐Máñez Ramón , Rurack Knut , Sancenón Félix 
Published: February 2012

AbstractSupramolecular interactions are vital processes in many chemical sensors, biochemical assays, and other analytical detection schemes. On the background of the current, rapidly developing, and constantly changing requirements for (bio)analytical techniques, the classical molecular host is increasingly overburdened to accomplish a specific analytical task with the desired selectivity and sensitivity. Instead, other signaling strategies have to be conceived that overcome the limits in signal output, dynamic range, or compound targeting, which are imminent to various traditional methods. A very promising approach is the combination of concepts of supramolecular chemistry with nanostructured or nanoscopic inorganic materials, that is, the development of hybrid sensor materials. Such hybrids often lead to improved functionality and enhanced performance, and the present chapter discusses the contributory features in relation to the major aspects, which are related to the enhanced coordination by the preorganization of binding sites, signal amplification by the preorganization on surfaces, aggregation‐mediated signaling, surface‐modification‐based signaling, the tuning of selectivity through polarity and size, and gated signaling.
Rotaxanes–Self‐Assembled Links
Authors: Ma Xiang , Tian He 
Published: February 2012

Abstract
Various rotaxanes continue to be a hot topic for research currently. This article mainly focuses on the construction strategies of rotaxanes. The traditional template‐directed strategies of rotaxane synthesis, including the employment of supramolecular interactions such as hydrogen bonding, hydrophobic effect, donor–acceptor π–π stacking interaction, coordination, and ionic template were reviewed, respectively. Some novel synthetic protocols, like “Click” chemistry, “threading‐followed‐by‐shrinking” and “threading‐followed‐by‐swelling” protocol, as well as self‐sorting organization, were also introduced. The synthesis of [1]rotaxanes was also illustrated.
Effects of Threat on Police Officers' Shooting Behavior: Anxiety, Action Specificity, and Affective Influences on Perception
Authors: Nieuwenhuys Arne , Cañal‐Bruland Rouwen , Oudejans Raôul R. D. 
Published: February 2012

SummaryIn the current study, we investigated the impact of threat and response mode on police officers' distance perception and shooting behavior in relation to a suspect that approached with a knife. To manipulate threat and increase anxiety, the suspect carried either a plastic knife (low threat) or an electrical knife (high threat). Regarding the manipulation of response mode, officers provided either an actual shooting response or indicated their shot verbally. In both cases, perceptual judgments of shooting distances were assessed through visual matching. Results show that high threat led to earlier shooting, but only for actual shooting responses. Although high threat generally induced more anxiety, perceptual judgments remained unaffected by threat and indicated systematic underestimations of the distance to the suspect. It is suggested that in the online control of action, increased anxiety does not affect distance perception but alters the functional relationship between distance and perceived threat, thereby causing officers to shoot the approaching suspect at an earlier stage. Copyright © 2012 John Wiley & Sons, Ltd.
Developmental origins of obesity: Early feeding environments, infant growth, and the intestinal microbiome
Authors: Thompson Amanda L. 
Published: February 2012

AbstractObjectives:Pediatric overweight and obesity are growing problems worldwide, with increasing prevalence among even infants and young children. The refractory nature of early overweight necessitates identifying the factors contributing to early excess weight gain for successful intervention. Early feeding practices may be particularly important in shaping long‐term vulnerability to obesity. How and what infants are fed can influence weight gain, adiposity, and energy metabolism during infancy and across the life course through a number of interacting physiological and behavioral pathways. This article argues that these biological mechanisms interact with the social and behavioral context of infant feeding to create differential vulnerability to later obesity.Methods:This article reviews recent research on the potential mechanisms linking infant feeding and risk of later obesity, focusing on the emerging role of microflora colonization.Results:The nutritive and non‐nutritive components of breastmilk, formula and solid foods and the practices surrounding feeding shape the infant metabolome, programming growth rates and body composition, altering metabolism and physiology, promoting differential microfloral colonization, and shaping behavioral responses to foods and eating.Conclusion:The occurrence of chronic disease precursors at increasingly younger ages and the tendency of overweight young children to become overweight adolescents and adults underscore the importance of understanding this complex early exposure and intervening early to prevent the development of obesity in increasingly weight‐promoting environments. Am. J. Hum. Biol. 2012. © 2012 Wiley Periodicals, Inc.
New craniodental material of Pronothodectes gaoi Fox (Mammalia, “Plesiadapiformes”) and relationships among members of Plesiadapidae
Authors: Boyer Doug M. , Scott Craig S. , Fox Richard C. 
Published: February 2012

AbstractPlesiadapidae are a family of Paleogene mammals thought to have phylogenetic affinities with modern Primates. We describe previously unpublished dentitions and the first skull and isolated petrosals of the plesiadapid Pronothodectes gaoi, collected from middle Tiffanian localities of the Paskapoo Formation in Alberta. Other species of Pronothodectes, traditionally considered the most basal members of the Plesiadapidae, occur at earlier, Torrejonian horizons in Montana, Wyoming, and Alberta. Classification of P. gaoi as a species of Pronothodectes has proved controversial; accordingly, we use the newly available samples and the more extensively preserved specimens to re‐evaluate the generic affinities of this species. Included in our study are comparisons with craniodental material known for other plesiadapids and plesiadapiforms. Cladistic analysis of craniodental characters is used to assess the hypothesis that P. gaoi and other species in this genus are basal members of the Plesiadapidae. The new dental evidence confirms that P. gaoi lacks derived character states of other plesiadapids except for a variably present fissuring of the m3 hypoconulid. Moreover, several aspects of the cranium seem to be more primitive in P. gaoi (i.e., more like nonplesiadapid plesiadapiforms) than in later occurring plesiadapids, such as Plesiadapis tricuspidens and Plesiadapis cookei. Cladistic analysis of craniodental morphology supports a basal position of P. gaoi among species of Plesiadapidae, with the exception of other species of Pronothodectes. The basicranium of P. gaoi preserves a laterally placed bony canal for the internal carotid neurovascular system, suggesting that this was the ancestral condition for the family. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.
Natural rubber/multiwalled carbon nanotube composites developed with a combined self‐assembly and latex compounding technique
Authors: Peng Zheng , Feng Chunfang , Luo Yongyue , Li Yongzhen , Yi Zhifeng , Kong L.X. 
Published: February 2012

AbstractCarbon nanotubes (CNTs), with their high aspect ratio and exceptionally high mechanical properties, are excellent fillers for composite reinforcement if they are uniformly dispersed without aggregation. Combining the latex compounding and self‐assembly techniques, we prepared a novel natural rubber (NR)/multiwalled carbon nanotube (MWCNT) composite. Before self‐assembly, the MWCNTs were treated with mixed acid to ensure that the MWCNTs were negatively charged under an alkaline environment. The structure of the MWCNTs was tested with Fourier transform infrared spectroscopy. The properties of composites with different MWCNT loadings were characterized with transmission electron microscopy, scanning electron microscopy, thermogravimetric analysis, and tensile testing. The results indicate that the MWCNTs were homogeneously distributed throughout the NR matrix as single tubes and had good interfacial adhesion with the NR phase when the MWCNT loading was less than 3 wt %. In particular, the addition of the MWCNT led to a remarkable reinforcement in the tensile strength, with a peak value of 31.4 MPa for an MWCNT content of 2 wt %, compared to the pure prevulcanized NR (tensile strength = 21.9 MPa). The nanocomposites reinforced with MWCNTs should have wide applications because of the notable improvement in these important properties. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012
Effect of zinc borate on the fire and thermal degradation behaviors of a poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate)‐containing intumescent flame retardant
Authors: Zhang Rui , Huang Hua , Yang Wei , Xiao Xifu , Hu Yuan 
Published: February 2012

AbstractThe aim of this study was to investigate the effect of zinc borate (ZnB) on the fire and thermal degradation behaviors of a poly(3‐hydroxybutyrate‐co‐4‐hydroxybutyrate) [P(3,4)HB]‐containing intumescent flame retardant (IFR). The IFR system was composed of ammonium polyphosphate, pentaerythritol, and melamine. The fire properties of P(3,4)HB/IFR/ZnB blends were evaluated by limited oxygen index, Underwriters Laboratories 94, microscale combustion calorimetry (MCC), and cone calorimetry (CONE) testing. The results of MCC and CONE show that the peak heat release rate, which is an important indicator of material fire hazard, of P(3,4)HB/IFR decreased when a small amount of the IFR was substituted by ZnB. The thermal degradation behavior of the P(3,4)HB/IFR/ZnB blends were measured by thermogravimetric analysis and thermogravimetric analysis–infrared (TG–IR) spectrometry. The data of TG–IR showed that the flammable gas products of P(3,4)HB released during the thermal degradation process were greatly decreased. Scanning electron microscopy analysis revealed that more compact char residues were observed with the incorporation of ZnB. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012