Assessing the Public’s Interest in Orofacial Pain Specialists: A Google Trends Analysis

Botros Jack,Padilla Mariela 대한안면통증∙구강내과학회 2023 Journal of Oral Medicine and Pain Vol.48 No.4

Purpose: To assess Google Trends (GT) search behavior regarding orofacial pain (OFP) and headaches. Methods: GT scores for OFP and headache specialists between February 2013 and December 2022 were analyzed. Statistical tests such as Poisson regression analyses, mean differences, and Cohen’s D were used to assess the score change over time. Results: The top three search words for OFP specialists were “temporomandibular joint (TMJ) specialist,” “TMJ doctor,” and “TMJ dentist,” whereas the top three search words for headache specialists were “Headache specialist,” “Headache doctor,” and “Migraine specialist.” Here, TMJ is temporomandibular joint. The GT scores for OFP specialists increased significantly (p<0.05) for all years except 2017, with the highest mean difference in 2020. The scores for headache specialists showed similar trends but gradually. Conclusions: The interest in OFP and headache specialists expressed by Google searches has increased over the years. More awareness is needed regarding the OFP scope of practice, and the use of GT may serve as an indicator.

Phenytoin-based Bivalent Ligands: Design, Synthesis and Anticonvulsant Activity

Samir Botros,Nadia A. Khalil,Bassem H. Naguib,Yara El-Dash 대한약학회 2012 Archives of Pharmacal Research Vol.35 No.12

Synthesis, characterization and anticonvulsant properties of new bivalent ligands derived from phenytoin were described. Initial anticonvulsant screening was performed using maximal electroshock (MES) and pentylenetetrazole (PTZ) screens in mice. The neurotoxicity for compounds that showed significant anticonvulsant activity was determined applying the rotorod test. Most of the test compounds were found to be effective in at least one seizure model in a dose of 100 mg/kg. Compound 5e exhibited marked anticonvulsant activity in both MES and PTZ screens. The computer-aided prediction of biological activity was carried out.

Strong and Reversible Binding of Carbon Dioxide in a Green Metal–Organic Framework

Gassensmith, Jeremiah J.,Furukawa, Hiroyasu,Smaldone, Ronald A.,Forgan, Ross S.,Botros, Youssry Y.,Yaghi, Omar M.,Stoddart, J. Fraser American Chemical Society 2011 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.133 No.39

<P>The efficient capture and storage of gaseous CO<SUB>2</SUB> is a pressing environmental problem. Although porous metal–organic frameworks (MOFs) have been shown to be very effective at adsorbing CO<SUB>2</SUB> selectively by dint of dipole–quadruple interactions and/or ligation to open metal sites, the gas is not usually trapped covalently. Furthermore, the vast majority of these MOFs are fabricated from nonrenewable materials, often in the presence of harmful solvents, most of which are derived from petrochemical sources. Herein we report the highly selective adsorption of CO<SUB>2</SUB> by CD-MOF-2, a recently described green MOF consisting of the renewable cyclic oligosaccharide γ-cyclodextrin and RbOH, by what is believed to be reversible carbon fixation involving carbonate formation and decomposition at room temperature. The process was monitored by solid-state <SUP>13</SUP>C NMR spectroscopy as well as colorimetrically after a pH indicator was incorporated into CD-MOF-2 to signal the formation of carbonic acid functions within the nanoporous extended framework.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2011/jacsat.2011.133.issue-39/ja206525x/production/images/medium/ja-2011-06525x_0003.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja206525x'>ACS Electronic Supporting Info</A></P>

Nanoporous Carbohydrate Metal–Organic Frameworks

Forgan, Ross S.,Smaldone, Ronald A.,Gassensmith, Jeremiah J.,Furukawa, Hiroyasu,Cordes, David B.,Li, Qiaowei,Wilmer, Christopher E.,Botros, Youssry Y.,Snurr, Randall Q.,Slawin, Alexandra M. Z.,Stoddar American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.1

<P>The binding of alkali and alkaline earth metal cations by macrocyclic and diazamacrobicyclic polyethers, composed of ordered arrays of hard oxygen (and nitrogen) donor atoms, underpinned the development of host–guest supramolecular chemistry in the 1970s and 1980s. The arrangement of −OCCO– and −OCCN– chelating units in these preorganized receptors, including, but not limited to, crown ethers and cryptands, is responsible for the very high binding constants observed for their complexes with Group IA and IIA cations. The cyclodextrins (CDs), cyclic oligosaccharides derived microbiologically from starch, also display this −OCCO– bidentate motif on both their primary and secondary faces. The self-assembly, in aqueous alcohol, of infinite networks of extended structures, which have been termed CD-MOFs, wherein γ-cyclodextrin (γ-CD) is linked by coordination to Group IA and IIA metal cations to form metal–organic frameworks (MOFs), is reported. CD-MOF-1 and CD-MOF-2, prepared on the gram-scale from KOH and RbOH, respectively, form body-centered cubic arrangements of (γ-CD)<SUB>6</SUB> cubes linked by eight-coordinate alkali metal cations. These cubic CD-MOFs are (i) stable to the removal of solvents, (ii) permanently porous, with surface areas of ∼1200 m<SUP>2</SUP> g<SUP>–1</SUP>, and (iii) capable of storing gases and small molecules within their pores. The fact that the −OCCO– moieties of γ-CD are not prearranged in a manner conducive to encapsulating single metal cations has led to our isolating other infinite frameworks, with different topologies, from salts of Na<SUP>+</SUP>, Cs<SUP>+</SUP>, and Sr<SUP>2+</SUP>. This lack of preorganization is expressed emphatically in the case of Cs<SUP>+</SUP>, where two polymorphs assemble under identical conditions. CD-MOF-3 has the cubic topology observed for CD-MOFs 1 and 2, while CD-MOF-4 displays a channel structure wherein γ-CD tori are perfectly stacked in one dimension in a manner reminiscent of the structures of some γ-CD solvates, but with added crystal stability imparted by metal–ion coordination. These new MOFs demonstrate that the CDs can indeed function as ligands for alkali and alkaline earth metal cations in a manner similar to that found with crown ethers. These inexpensive, green, nanoporous materials exhibit absorption properties which make them realistic candidates for commercial development, not least of all because edible derivatives, fit for human consumption, can be prepared entirely from food-grade ingredients.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-1/ja208224f/production/images/medium/ja-2011-08224f_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja208224f'>ACS Electronic Supporting Info</A></P>

High hopes: can molecular electronics realise its potential?

Coskun, Ali,Spruell, Jason M.,Barin, Gokhan,Dichtel, William R.,Flood, Amar H.,Botros, Youssry Y.,Stoddart, J. Fraser The Royal Society of Chemistry 2012 Chemical Society reviews Vol.41 No.14

<P>Manipulating and controlling the self-organisation of small collections of molecules, as an alternative to investigating individual molecules, has motivated researchers bent on processing and storing information in molecular electronic devices (MEDs). Although numerous ingenious examples of single-molecule devices have provided fundamental insights into their molecular electronic properties, MEDs incorporating hundreds to thousands of molecules trapped between wires in two-dimensional arrays within crossbar architectures offer a glimmer of hope for molecular memory applications. In this critical review, we focus attention on the collective behaviour of switchable mechanically interlocked molecules (MIMs)—specifically, bistable rotaxanes and catenanes—which exhibit reset lifetimes between their ON and OFF states ranging from seconds in solution to hours in crossbar devices. When these switchable MIMs are introduced into high viscosity polymer matrices, or self-assembled as monolayers onto metal surfaces, both in the form of nanoparticles and flat electrodes, or organised as tightly packed islands of hundreds and thousands of molecules sandwiched between two electrodes, the thermodynamics which characterise their switching remain approximately constant while the kinetics associated with their reset follow an intuitively predictable trend—that is, fast when they are free in solution and sluggish when they are constrained within closely packed monolayers. The importance of seamless interactions and constant feedback between the makers, the measurers and the modellers in establishing the structure-property relationships in these integrated functioning systems cannot be stressed enough as rationalising the many different factors that impact device performance becomes more and more demanding. The choice of electrodes, as well as the self-organised superstructures of the monolayers of switchable MIMs employed in the molecular switch tunnel junctions (MSTJs) associated with the crossbars of these MEDs, have a profound influence on device operation and performance. It is now clear, after much investigation, that a distinction should be drawn between two types of switching that can be elicited from MSTJs. One affords small ON/OFF ratios and is a direct consequence of the switching in bistable MIMs that leads to a relatively small remnant molecular signature—an activated chemical process. The other leads to a very much larger signature and ON/OFF ratios resulting from physical or chemical changes in the electrodes themselves. Control experiments with various compounds, including degenerate catenanes and free dumbbells, which cannot and do not switch, are crucial in establishing the authenticity of the small ON/OFF ratios and remnant molecular signatures produced by bistable MIMs. Moreover, experiments conducted on monolayers in MSTJs of molecules designed to switch and molecules designed not to switch have been probed directly by spectroscopic and other means in support of MEDs that store information through switching collections of bistable MIMs contained in arrays of MSTJs. In the quest for the next generation of MEDs, it is likely that monolayers of bistable MIMs will be replaced by robust crystalline extended structures wherein the switchable components, derived from bistable MIMs, are organised precisely in a periodic manner.</P> <P>Graphic Abstract</P><P>There is a world of difference between a molecular electronic device which switches at high (blue) rather than at low (red) bias. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cs35053j'> </P>

Radically Enhanced Molecular Switches

Fahrenbach, Albert C.,Zhu, Zhixue,Cao, Dennis,Liu, Wei-Guang,Li, Hao,Dey, Sanjeev K.,Basu, Subhadeep,Trabolsi, Ali,Botros, Youssry Y.,Goddard, William A.,Stoddart, J. Fraser American Chemical Society 2012 JOURNAL OF THE AMERICAN CHEMICAL SOCIETY - Vol.134 No.39

<P>The mechanism governing the redox-stimulated switching behavior of a tristable [2]rotaxane consisting of a cyclobis(paraquat-<I>p</I>-phenylene) (CBPQT<SUP>4+</SUP>) ring encircling a dumbbell, containing tetrathiafulvalene (TTF) and 1,5-dioxynaphthalene (DNP) recognition units which are separated from each other along a polyether chain carrying 2,6-diisopropylphenyl stoppers by a 4,4′-bipyridinium (BIPY<SUP>2+</SUP>) unit, is described. The BIPY<SUP>2+</SUP> unit acts to increase the lifetime of the metastable state coconformation (MSCC) significantly by restricting the shuttling motion of the CBPQT<SUP>4+</SUP> ring to such an extent that the MSCC can be isolated in the solid state and is stable for weeks on end. As controls, the redox-induced mechanism of switching of two bistable [2]rotaxanes and one bistable [2]catenane composed of CBPQT<SUP>4+</SUP> rings encircling dumbbells or macrocyclic polyethers, respectively, that contain a BIPY<SUP>2+</SUP> unit with either a TTF or DNP unit, is investigated. Variable scan-rate cyclic voltammetry and digital simulations of the tristable and bistable [2]rotaxanes and [2]catenane reveal a mechanism which involves a bisradical state coconformation (BRCC) in which only one of the BIPY<SUP>•+</SUP> units in the CBPQT<SUP>2(•+)</SUP> ring is oxidized to the BIPY<SUP>2+</SUP> dication. This observation of the BRCC was further confirmed by theoretical calculations as well as by X-ray crystallography of the [2]catenane in its bisradical tetracationic redox state. It is evident that the incorporation of a kinetic barrier between the donor recognition units in the tristable [2]rotaxane can prolong the lifetime and stability of the MSCC, an observation which augurs well for the development of nonvolatile molecular flash memory devices.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/2012/jacsat.2012.134.issue-39/ja306044r/production/images/medium/ja-2012-06044r_0014.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ja306044r'>ACS Electronic Supporting Info</A></P>

Polyporous Metal-Coordination Frameworks

Gassensmith, Jeremiah J.,Smaldone, Ronald A.,Forgan, Ross S.,Wilmer, Christopher E.,Cordes, David B.,Botros, Youssry Y.,Slawin, Alexandra M. Z.,Snurr, Randall Q.,Stoddart, J. Fraser American Chemical Society 2012 ORGANIC LETTERS Vol.14 No.6

<P>Starting from a chiral building block?α-cyclodextrin?and rubidium salts, the crystallization of a complex of chiral helices, which constitute a “green” porous coordination polymer, has been realized. Cyclodextrin molecules coordinated by rubidium ions form porous, infinitely long left-handed helical channels, interdigitated with each other. A theoretical examination of the potential of this new material to act as a medium for chiral separation is presented.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2012/orlef7.2012.14.issue-6/ol300199a/production/images/medium/ol-2012-00199a_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol300199a'>ACS Electronic Supporting Info</A></P>

Stimulated Release of Size‐Selected Cargos in Succession from Mesoporous Silica Nanoparticles

Wang, Cheng,Li, Zongxi,Cao, Dennis,Zhao, Yan‐,Li,Gaines, Justin W.,Bozdemir, O. Altan,Ambrogio, Michael W.,Frasconi, Marco,Botros, Youssry Y.,Zink, Jeffrey I.,Stoddart, J. Fraser WILEY‐VCH Verlag 2012 Angewandte Chemie Vol.124 No.22

<P><B>Zwei Fliegen mit einer Klappe</B>: Die kovalente Bindung von β‐Cyclodextrin (gelb; siehe Bild) an mesoporöse Siliciumdioxid‐Nanopartikel (MSNs) ergibt ein duales Freisetzungssystem, das mit unterschiedlich großen Wirkstoffen (blaue und rote Kugeln) beladen werden kann, die sich auf verschiedene Stimuli hin nacheinander freisetzen lassen. Die kleineren Moleküle werden durch Absenken des pH‐Wertes freigesetzt, die größeren nach Abspaltung der Cyclodextrine von der MSN‐Oberfläche.</P>