bluuebunny/crossref_metadata_2025 huggingface dataset:
Instant Visual Detection of Picogram Levels of Trinitrotoluene by Using Luminescent Metal–Organic Framework Gel‐Coated Filter Paper
Authors: Lee Ji Ha , Kang Sunwoo , Lee Jin Yong , Jaworski Justyn , Jung Jong Hwa
Published: November 2013

There is an ongoing need for explosive detection strategies to uncover threats to human security including illegal transport and terrorist activities. The widespread military use of the explosive trinitrotoluene (TNT) for landmines poses another particular threat to human health in the form of contamination of the surrounding environment and groundwater. The detection of explosives, particularly at low picogram levels, by using a molecular sensor is seen as an important challenge. Herein, we report on the use of a fluorescent metal–organic framework hydrogel that exhibits a higher detection capability for TNT in the gel state compared with that in the solution state. A portable sensor prepared from filter paper coated by the hydrogel was able to detect TNT at the picogram level with a detection limit of 1.82 ppt (parts per trillon). Our results present a simple and new means to provide selective detection of TNT on a surface or in aqueous solution, as afforded by the unique molecular packing through the metal–organic framework structure in the gel formation and the associated photophysical properties. Furthermore, the rheological properties of the MOF‐based gel were similar to those of a typical hydrogel.
Spectroscopic Elucidation of the Inhibitory Mechanism of Cys2His2 Zinc Finger Transcription Factors by Cobalt(III) Schiff Base Complexes
Authors: Heffern Marie C. , Kurutz Josh W. , Meade Thomas J.
Published: November 2013

Transcription factors are key regulators in both normal and pathological cell processes. Affecting the activity of these proteins is a promising strategy for understanding gene regulation and developing effective therapeutics. CoIII Schiff base complexes ([Co(acacen)(L)2]+ where L=labile axial ligands) have been shown to be potent inhibitors of a number of zinc metalloproteins including Cys2His2 zinc finger transcription factors. Inhibition by [Co(acacen)(L)2]+ of the target protein is believed to occur through a dissociative exchange of the labile axial ligands for histidine (His) residues essential for function. Here, we report a series of spectroscopic investigations with model peptides of zinc fingers that elucidate the interaction between [Co(acacen)(L)2]+ complexes and zinc finger transcription factors. Observed changes in NMR chemical shifts and 2D 1H‐1H NOESY NMR spectra demonstrate the preference of [Co(acacen)(L)2]+ complexes to coordinate His residues over other amino acids. The conformation of [Co(acacen)(L)2]+ upon His coordination was characterized by 1H NMR spectroscopy, near‐UV CD, and electronic absorption. These studies reveal that the resulting His‐coordinated [Co(acacen)(L)2]+ complex possesses an octahedral structure. The effects of [Co(acacen)(L)2]+ complexes on the zinc‐finger structure were assessed by the degree of hydrogen bonding (probed by 2D NMR spectroscopy) and secondary‐structure profiles measured by far‐UV CD. These structural studies demonstrate the ability of [Co(acacen)(L)2]+ complexes to disrupt the ββα structure of zinc fingers, resulting in primarily random‐coil conformations. A mechanism is described wherein [Co(acacen)(L)2]+ complexes inhibit zinc finger transcription factor activity through selectively coordinating His residues in the zinc finger by dissociative ligand exchange and disrupting the ββα structural motif required for gene regulation.
Conformational Change from a Twisted Figure‐Eight to an Open‐Extended Structure in Doubly Fused 36π Core‐Modified Octaphyrins Triggered by Protonation: Implication on Photodynamics and Aromaticity
Authors: Karthik Ganesan , Lim Jong Min , Srinivasan A. , Suresh C. H. , Kim Dongho , Chandrashekar Tavarekere K.
Published: November 2013

Two examples of core‐modified 36π doubly fused octaphyrins that undergo a conformational change from a twisted figure‐eight to an open‐extended structure induced by protonation are reported. Syntheses of the two octaphyrins (in which Ar=mesityl or tolyl) were achieved by a simple acid‐catalyzed condensation of dipyrrane unit containing an electron‐rich, rigid dithienothiophene (DTT) core with pentafluorobenzaldehyde followed by oxidation with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ). The single‐crystal X‐ray structure of the octaphyrin (in which Ar=mesityl) shows a figure‐eight twisted conformation of the expanded porphyrin skeleton with two DTT moieties oriented in a staggered conformation with a π‐cloud distance of 3.7 Å. Spectroscopic and quantum mechanical calculations reveal that both octaphyrins conform to a [4n]π nonaromatic electronic structure. Protonation of the pyrrole nitrogen atoms of the octaphyrins results in dramatic structural change, which led to 1) a large redshift and sharpening of absorption bands in electronic absorption spectrum, 2) a large change in chemical shift of pyrrole β‐CH and NH protons in the 1H NMR spectrum, 3) a small increase in singlet lifetimes, and 4) a moderate increase in two‐photon absorption cross‐section values. Furthermore, nucleus‐independent chemical shift (NICS) values calculated at various geometrical positions show positive values and anisotropy‐induced current density (AICD) plots indicate paratropic ring‐currents for the diprotonated form of the octaphyrin (in which Ar=tolyl); the single‐crystal X‐ray structure of the diprotonated form of the octaphyrin shows an extended structure in which one of the pyrrole ring of each dipyrrin subunit undergoes a 180 ° ring‐flip. Four trifluoroacetic acid (TFA) molecules are bound above and below the molecular plane defined by meso‐carbon atoms and are held by NH⋅⋅⋅O, NH⋅⋅⋅F, and CH⋅⋅⋅F intermolecular hydrogen‐bonding interactions. The extended‐open structure upon protonation allows π‐delocalization and the electronic structure conforms to a [4n]π Hückel antiaromatic in the diprotonated state.
Formation of Substituted Oxa‐ and Azarhodacyclobutanes
Authors: Dauth Alexander , Rigling Carla , Tsoung Jennifer , Love Jennifer A.
Published: November 2013

The preparation of substituted oxa‐ and azarhodacyclobutanes is reported. After exchange of ethylene with a variety of unsymmetrically and symmetrically substituted alkenes, the corresponding rhodium–olefin complexes were oxidized with H2O2 and PhINTs (Ts=p‐toluenesulfonyl) to yield the substituted oxa‐ and azarhodacyclobutanes, respectively. Oxarhodacyclobutanes could be prepared with excellent selectivity for incorporation of the oxygen atom on the more substituted carbon atom of the alkene. At the same time, azarhodacyclobutanes showed good‐to‐excellent selectivity for heteroatom incorporation on the less substituted carbon. Furthermore, it was shown that steric modifications of the ancillary ligand have a significant influence on the selectivity of Rh–olefin complex formation as well as formation of the substituted azametallacycles.
A Sulfonic‐Azobenzene‐Grafted Silica Amphiphilic Material: A Versatile Stationary Phase for Mixed‐Mode Chromatography
Authors: Qiu Hongdeng , Zhang Mingliang , Gu Tongnian , Takafuji Makoto , Ihara Hirotaka
Published: November 2013

A novel sulfonic‐azobenzene‐functionalized amphiphilic silica material was synthesized through the preparation of a new sulfonic azobenzene monomer and its grafting on mercaptopropyl‐modified silica by a surface‐initiated radical chain‐transfer reaction. The synthesis was confirmed by infrared spectra, elemental analysis, and thermogravimetric analysis. This new material was successfully applied as a new kind of mixed‐mode stationary phase in liquid chromatography. This allows an exceptionally flexible adjustment of retention and selectivity by tuning the experimental conditions. The distinct separation mechanisms were outlined by selected examples of chromatographic separations in the different modes. In reversed‐phase liquid chromatography, this new stationary phase presented specific chromatographic performance when evaluated using a Tanaka test mixture. Seven dinitro aromatic isomers, four steroids, and seven flavonoids were separated successfully in simple reversed‐phase mode. This stationary phase can also be used in hydrophilic interaction chromatography because of the existing polar functional groups; for this, nucleosides and their bases were used as a test mixture. Interestingly, the same nucleosides and bases can also be separated in per aqueous liquid chromatography using the same stationary phase. Three ginsenosides including Rg1, Re, and Rb1 were successfully separated in hydrophilic mode. There is the potential for more applications to benefit from this useful column.
Tetrathiafulvalene‐Based Mixed‐Valence Acceptor–Donor–Acceptor Triads: A Joint Theoretical and Experimental Approach
Authors: Calbo Joaquín , Aragó Juan , Otón Francisco , Lloveras Vega , Mas‐Torrent Marta , Vidal‐Gancedo José , Veciana Jaume , Rovira Concepció , Ortí Enrique
Published: November 2013

This work presents a joint theoretical and experimental characterisation of the structural and electronic properties of two tetrathiafulvalene (TTF)‐based acceptor–donor–acceptor triads (BQ–TTF–BQ and BTCNQ–TTF—BTCNQ; BQ is naphthoquinone and BTCNQ is benzotetracyano‐p‐quinodimethane) in their neutral and reduced states. The study is performed with the use of electrochemical, electron paramagnetic resonance (EPR), and UV/Vis/NIR spectroelectrochemical techniques guided by quantum‐chemical calculations. Emphasis is placed on the mixed‐valence properties of both triads in their radical anion states. The electrochemical and EPR results reveal that both BQ–TTF–BQ and BTCNQ–TTF–BTCNQ triads in their radical anion states behave as class‐II mixed‐valence compounds with significant electronic communication between the acceptor moieties. Density functional theory calculations (BLYP35/cc‐pVTZ), taking into account the solvent effects, predict charge‐localised species (BQ.−–TTF–BQ and BTCNQ.−–TTF–BTCNQ) as the most stable structures for the radical anion states of both triads. A stronger localisation is found both experimentally and theoretically for the BTCNQ–TTF–BTCNQ anion, in accordance with the more electron‐withdrawing character of the BTCNQ acceptor. CASSCF/CASPT2 calculations suggest that the low‐energy, broad absorption bands observed experimentally for the BQ–TTF–BQ and BTCNQ–TTF–BTCNQ radical anions are associated with the intervalence charge transfer (IV‐CT) electronic transition and two nearby donor‐to‐acceptor CT excitations. The study highlights the molecular efficiency of the electron‐donor TTF unit as a molecular wire connecting two acceptor redox centres.
Photoinduced Charge Separation in Zinc–Porphyrin/Tungsten–Alkylidyne Dyads: Generation of Reactive Porphyrin and Metallo Radical States
Authors: Moravec Davis B. , Hopkins Michael D.
Published: November 2013

The luminescent tungsten–alkylidyne metalloligand [WCl(≡C‐4,4′‐C6H4CC‐py)(dppe)2] (1; dppe=1,2‐bis(diphenylphosphino)ethane) and the zinc–tetraarylporphyrins ZnTPP and ZnTPClP (TPP=tetraphenylporphyrin, TPClP=tetra(p‐chlorophenyl)porphyrin) self‐assemble in fluorobenzene solution to form the dyads ZnTPP(1) and ZnTPClP(1), in which the metalloligand is axially coordinated to the porphyrin. Excitation of the porphyrin‐centered S1 excited states of these dyads initiates intramolecular energy‐transfer (ZnPor→1) and electron‐transfer (1→ZnPor) processes, which together efficiently quench the S1 state (∼90 %). Transient‐absorption spectroscopy and an associated kinetic analysis reveal that the net product of the energy‐transfer process is the 3[dπ*] state of coordinated 1, which is formed by S1→1[dπ*] singlet–singlet (Förster) energy transfer followed by 1[dπ*]→3[dπ*] intersystem crossing. The data also demonstrate that coordinated 1 reductively quenches the porphyrin S1 state to produce the [ZnPor−][1+] charge‐separated state. This is a rare example of the reductive quenching of zinc porphyrin chromophores. The presence in the [ZnPor−][1+] charge‐separated states of powerfully reducing zinc–porphyrin radical anions, which are capable of sensitizing a wide range of reductive electrocatalysts, and the 1+ ion, which can initiate the oxidation of H2, produces an integrated photochemical system with the thermodynamic capability of driving photoredox processes that result in the transfer of renewable reducing equivalents instead of the consumption of conventional sacrificial donors.
Rhetorical profiling: Modes of meaning generation in organizational topoi
Authors: Barker James , Gilmore Sarah , Gilson Clive
Published: November 2013

Accounting for homogenous action in seemingly apparent heterogeneous organizations is a research question that persists across prominent organizational studies literatures, and which have become more persistent and pertinent as organizations have become more global and diverse. To address how differing forms of relatively homogeneous solutions to practical problems arise from otherwise heterogeneous organizations, we develop a rhetorical framework that depicts the role of topoi, often understood as a theme or motif or literary convention, in an organization's rhetorical activity and facilitates the profiling of organizations according to how members use topoi as modes of meaning creation. We assert 10 propositions reflecting how members invent and legitimize functional meaning and demonstrate how such meaning can direct the organization toward different discursive paths. Copyright © 2013 ASAC. Published by John Wiley & Sons, Ltd.
A simplified method for assessing cytotechnologist workload
Authors: Vaickus Louis J. , Tambouret Rosemary
Published: November 2013

BACKGROUND

Examining cytotechnologist workflow and how it relates to job performance and patient safety is important in determining guidelines governing allowable workloads. This report discusses the development of a software tool that significantly simplifies the process of analyzing cytotechnologist workload while simultaneously increasing the quantity and resolution of the data collected.

METHODS

The program runs in Microsoft Excel and minimizes manual data entry and data transcription by automating as many tasks as is feasible.

RESULTS

Data show the cytotechnologists tested were remarkably consistent in the amount of time it took them to screen a cervical cytology (Gyn) or a nongynecologic cytology (Non‐Gyn) case and that this amount of time was directly proportional to the number of slides per case. Namely, the time spent per slide did not differ significantly in Gyn versus Non‐Gyn cases (216 ± 3.4 seconds and 235 ± 24.6 seconds, respectively; P = .16). There was no significant difference in the amount of time needed to complete a Gyn case between the morning and the evening (314 ± 4.7 seconds and 312 ± 7.1 seconds; P = .39), but a significantly increased time spent screening Non‐Gyn cases (slide‐adjusted) in the afternoon hours (323 ± 20.1 seconds and 454 ± 67.6 seconds; P = .027), which was largely the result of significantly increased time spent on prescreening activities such as checking the electronic medical record (62 ± 6.9 seconds and 145 ± 36 seconds; P = .006).

CONCLUSIONS

This Excel‐based data collection tool generates highly detailed data in an unobtrusive manner and is highly customizable to the individual working environment and clinical climate. Cancer (Cancer Cytopathol) 2014;122:15–22. © 2013 American Cancer Society.
Molecular‐Level Understanding of Ground‐ and Excited‐State OH⋅⋅⋅O Hydrogen Bonding Involving the Tyrosine Side Chain: A Combined High‐Resolution Laser Spectroscopy and Quantum Chemistry Study
Authors: Biswal Himansu S. , Bhattacharyya Surjendu , Wategaonkar Sanjay
Published: November 2013

The present study combines both laser spectroscopy and ab initio calculations to investigate the intermolecular OH⋅⋅⋅O hydrogen bonding of complexes of the tyrosine side chain model chromophore compounds phenol (PH) andpara‐cresol (pCR) with H2O, MeOH, PH andpCR in the ground (S0) state as well as in the electronic excited (S1) state. All the experimental and computational findings suggest that the H‐bond strength increases in the S1state and irrespective of the hydrogen bond acceptor used, the dispersion energy contribution to the total interaction energy is about 10–15 % higher in the S1state compared to that in the S0state. The alkyl‐substituted (methyl; +I effect) H‐bond acceptor forms a significantly stronger H bond both in the S0and the S1state compared to H2O, whereas the aryl‐substituted (phenyl; −R effect) H‐bond donor shows a minute change in energy compared to H2O. The theoretical study emphasizes the significant role of the dispersive interactions in the case of thepCR and PH dimers, in particular the CH⋅⋅⋅O and the CH⋅⋅⋅π interactions between the donor and acceptor subunits in controlling the structure and the energetics of the aromatic dimers. The aromatic dimers do not follow the acid–base formalism, which states that the stronger the base, the more red‐shifted is the XH stretching frequency, and consequently the stronger is the H‐bond strength. This is due to the significant contribution of the dispersion interaction to the total binding energy of these compounds.
Ionic Liquid‐Assisted Route to Nanocrystalline Single‐Phase Phosphors for White Light‐Emitting Diodes
Authors: Lorbeer Chantal , Mudring Anja‐Verena
Published: November 2013

White light‐emitting diodes represent the future generation of domestic and public lighting, substituting the currently favored (compact) fluorescent lamps. Research on improving the performance and costs leads to a focus on processing constraints. The optimization of the grain size is judged to be an important tool for minimizing the necessary amount of (expensive rare‐earth containing) phosphors. Using only one type of phosphor that emits white light instead of a mixture of three phosphors (one for blue, green, and red, respectively) will significantly improve the characteristics of future light‐emitting diodes. Small, 6–8 nm‐sized particles emit intense white light observable by the naked eye. The emission color has been studied by varying the dopant ion concentrations as well as the excitation wavelengths, yielding white light close to standard daylight.
Effect of Annealing Temperature on Microstructure and UV Light Photocatalytic Activity of TiO2 Films Grown by Atmospheric Pressure CVD
Authors: Chua Chin Sheng , Fang Xiaoqin , Chen Xiaofeng , Tan Ooi Kiang , Tse Man Siu , Soutar Andrew McIntosh , Ding Xingzhao
Published: November 2013

Titanium dioxide (TiO2) films are deposited on quartz substrates by atmospheric pressure (AP)CVD, and then annealed under simulated air (80% nitrogen, 20% oxygen) at temperatures from 600 to 900 °C to investigate the change in microstructure and the effect on the photocatalytic activity on the simulated pollutant stearic acid. The as‐deposited TiO2 film is mainly composed of pure anatase phase while the rutile phase is detected only after annealing the film at 900 °C for 1 h. The photocatalytic activity of the annealed films on stearic acid under UV irradiation is found to deteriorate after the films are annealed at temperatures above 700 °C. This decrease in photocatalytic performance is observed to be the result of two possible mechanisms induced by the annealing temperature. The first mechanism is the increase in defect concentration (O− and Ti vacancies) in the annealed TiO2 films for annealing temperatures below 800 °C, and the second mechanism is the formation of large rutile grains at a higher temperature, 900 °C.
Electrochemical Characterization of Egyptian Blue Pigment in Wall Paintings Using the Voltammetry of Microparticles Methodology
Authors: Doménech‐Carbó Antonio , Doménech‐Carbó María Teresa , López‐López Francisco , Valle‐Algarra Francisco Manuel , Osete‐Cortina Laura , Haartman Estrella Arcos‐Von
Published: November 2013

The solid state voltammetric response of Egypt blue, Han blue and ploss blue pigments upon attachment to graphite electrodes in contact with aqueous phosphate buffer at pH 7.0 is studied by voltammetry of microparticles and scanning electrochemical microscopy. Such voltammetric responses, combined with those for synthetic specimens consisting of binary mixtures of the pigment and SiO2 or CaCO3 as well as ternary ones of CaCO3 and SiO2 mixtures allow for the identification of the pigment and the support in samples from wall paintings using different electrochemical parameters, in particular upon performing the Tafel and modified Tafel analysis of voltammetric peaks. Identification of Egypt blue in microsamples of murals from a Roman archaeological site in Castulo (Jaén, Spain) is discussed.
Src is activated by the nuclear receptor peroxisome proliferator‐activated receptor β/δ in ultraviolet radiation‐induced skin cancer
Authors: Montagner Alexandra , Delgado Maria B , Tallichet‐Blanc Corinne , Chan Jeremy S K , Sng Ming K , Mottaz Hélène , Degueurce Gwendoline , Lippi Yannick , Moret Catherine , Baruchet Michael , Antsiferova Maria , Werner Sabine , Hohl Daniel , Al Saati Talal , Farmer Pierre J , Tan Nguan S , Michalik Liliane , Wahli Walter
Published: November 2013

Although non‐melanoma skin cancer (NMSC) is the most common human cancer and its incidence continues to rise worldwide, the mechanisms underlying its development remain incompletely understood. Here, we unveil a cascade of events involving peroxisome proliferator‐activated receptor (PPAR) β/δ and the oncogene Src, which promotes the development of ultraviolet (UV)‐induced skin cancer in mice. UV‐induced PPARβ/δ activity, which directly stimulated Src expression, increased Src kinase activity and enhanced the EGFR/Erk1/2 signalling pathway, resulting in increased epithelial‐to‐mesenchymal transition (EMT) marker expression. Consistent with these observations, PPARβ/δ‐null mice developed fewer and smaller skin tumours, and a PPARβ/δ antagonist prevented UV‐dependent Src stimulation. Furthermore, the expression of PPARβ/δ positively correlated with the expression of SRC and EMT markers in human skin squamous cell carcinoma (SCC), and critically, linear models applied to several human epithelial cancers revealed an interaction between PPARβ/δ and SRC and TGFβ1 transcriptional levels. Taken together, these observations motivate the future evaluation of PPARβ/δ modulators to attenuate the development of several epithelial cancers.
Use of diffusive gradients in thin films (DGT) as an early detection tool of low‐intensity leakage from CO2 storage
Authors: Agnelli Marco , Grandia Fidel , Credoz Anthony , Gasparini Andrea , Bruno Jordi
Published: November 2013

Diffusive gradients in thin films (DGT) have been tested in CO2‐rich, metal‐bearing fluids from springs in the Campo de Calatrava region in Central Spain, to assess their applicability as a monitoring tool in onshore CO2 storage projects. These films are capable of adsorbing metals and recording changes in their concentration in water, sediments, and soils. Considering that CO2 dissolution promotes metal solubilization and transport, the use of these films could be valuable as a monitoring tool of early leakage.

A number of DGT have been deployed in selected springs with constant metal concentration. The studied waters show high concentrations of Fe, as high as 1 × 104 μg·L−1, Ni, Co, Zn, Cu, and Mn. Comparing re‐calculated metal concentration in DGT with metal water concentration, two different metal behaviors are observed: (i) metals with sorption consistent with the metal concentration (i.e. plotting close to the 1:1 line in a [Me]DGT: [Me]water plot), and (ii) metals with non−linear sorption, with some data showing metal enrichment in DGT compared with the concentration in water. Metals in the first group include Fe, Mn, Co, Ni, and U, and metals in the second group are Zn, Pb, Cr, Cu, and Al. From this research, it is concluded that the metals in the first group can be used to monitor potential leakage by using DGT, providing effective leakage detection even considering low variations of concentrations, episodic metal release, and reducing costs compared with conventional, periodic water sampling.
First meeting of the European canine lymphoma group. Workshop: state of the art and comparative aspects in canine lymphoma. CH‐Lugano, 22 June 2013
Authors: Comazzi Stefano , Guscetti Franco , Marconato Laura
Published: November 2013

This satellite meeting to the 12th International Conference on Malignant Lymphoma was conceived to bring together European researchers focused on canine lymphoma to explore several facets of this promising model of human disease. A series of invited lectures showed striking similarities between the two diseases namely in topics related to pathogenesis, diagnosis and classification and therapy. In particular, the potential value of the model was shown at the level of the NF‐kB/p65 pathway, the Bcl‐2 family of proteins, Ki67 and the S‐phase fraction, as well as the MMPs, VEGF and PDGF. The utility of the growing body of well‐characterized canine cell lines was stressed. The value of cytology and flow cytometry as tools for diagnosis, disease progression monitoring and prognosis were emphasized, whereas the failure so far of the standard immunohistochemical panel to differentiate between germinal centre and non‐germinal centre diffuse large B‐cell lymphomas subtypes in dogs was discussed. Further contributions included the report of encouraging results from a chemo‐immunotherapy trial administered to dogs with diffuse large B‐cell lymphoma, an overview on the use of radiation therapy for canine lymphoma and the role of surgery in splenic lymphoma. Altogether, the success of this meeting, attended by more than 160 participants, documents the rising interest for the spontaneous canine lymphoma model. Copyright © 2013 John Wiley & Sons, Ltd.
Calcium montmorillonite clay reduces AFB1 and FB1 biomarkers in rats exposed to single and co‐exposures of aflatoxin and fumonisin
Authors: Mitchell Nicole J. , Xue Kathy S. , Lin Shuhan , Marroquin‐Cardona Alicia , Brown Kristal A. , Elmore Sarah E. , Tang Lili , Romoser Amelia , Gelderblom Wentzel C. A. , Wang Jia‐Sheng , Phillips Timothy D.
Published: November 2013

Aflatoxins (AFs) and fumonisins (FBs) can co‐contaminate foodstuffs and have been associated with hepatocellular and esophageal carcinomas in humans at high risk for exposure. One strategy to reduce exposure (and toxicity) from contaminated foodstuffs is the dietary inclusion of a montmorillonite clay (UPSN) that binds AFs and FBs in the gastrointestinal tract. In this study, the binding capacity of UPSN was evaluated for AFB1, FB1 and a combination thereof in Fischer 344 rats. Rats were pre‐treated with different dietary levels of UPSN (0.25% or 2%) for 1 week. Rats were gavaged with a single dose of either 0.125 mg AFB1 or 25 mg FB1 per kg body weight and a combination thereof in the presence and absence of an aqueous solution of UPSN. The kinetics of mycotoxin excretion were monitored by analyzing serum AFB1‐albumin, urinary AF (AFM1) and FB1 biomarkers over a period of 72 h. UPSN decreased AFM1 excretion by 88–97%, indicating highly effective binding. FB1 excretion was reduced, to a lesser extent, ranging from 45% to 85%. When in combination, both AFB1 and FB1 binding occurred, but capacity was decreased by almost half. In the absence of UPSN, the combined AFB1 and FB1 treatment decreased the urinary biomarkers by 67% and 45% respectively, but increased levels of AFB1‐albumin, presumably by modulating its cytochrome metabolism. UPSN significantly reduced bioavailability of both AFB1 and FB1 when in combination; suggesting that it can be utilized to reduce levels below their respective thresholds for affecting adverse biological effects. Copyright © 2013 John Wiley & Sons, Ltd.
Evaluation of cytotoxic, oxidative stress and genotoxic responses of hydroxyapatite nanoparticles on human blood cells
Authors: Turkez Hasan , Yousef Mokhtar I. , Sönmez Erdal , Togar Başak , Bakan Feray , Sozio Piera , Stefano Antonio Di
Published: November 2013

The present study was designed to investigate genotoxic and cytotoxic effects and oxidative damage of increasing concentrations of nano‐hydroxyapatite (5, 10, 20, 50, 75, 100, 150, 300, 500 and 1000 ppm) in primary human blood cell cultures. Cell viability was detected by [3‐(4,5‐dimethyl‐thiazol‐2‐yl) 2,5‐diphenyltetrazolium bromide] assay and lactate dehydrogenase release, while total antioxidant capacity and total oxidative stress levels were determined to evaluate the oxidative injury. The DNA damage was also analyzed by sister chromatid exchange, micronuclei, chromosome aberration assays and 8‐oxo‐2‐deoxyguanosine level as indicators of genotoxicity. The results of [3‐(4,5‐dimethyl‐thiazol‐2‐yl) 2,5‐diphenyltetrazolium bromide] and lactate dehydrogenase assays showed that the higher concentrations (150, 300, 500 and 1000 ppm) of hydroxyapatite nanoparticles (HAP NPs) decreased cell viability. HAP NPs led to increases of total oxidative stress (300, 500 and 1000 ppm) levels and decreased total antioxidant capacity (150, 300, 500 and 1000 ppm) levels in cultured human blood cells. On the basis of increasing concentrations, HAP NPs caused significant increases of sister chromatid exchange, micronuclei, chromosome aberration rates and 8‐oxo‐2‐deoxyguanosine levels as compared to untreated culture. In conclusion, the obtained in vitro results showed that HAP NPs had dose‐dependent effects on inducing oxidative damage, genotoxicity and cytotoxicity in human blood cells. Copyright © 2013 John Wiley & Sons, Ltd.
Temporal variation in the deposition of different types of collagen within a porous biomaterial implant
Authors: White Jacinta F. , Werkmeister Jerome A. , Bisucci Teresa , Darby Ian A. , Ramshaw John A. M.
Published: November 2013

The deposition of new collagen in association with a medical implant has been studied using expanded polytetrafluoroethylene vascular replacement samples implanted subcutaneously in sheep, for up to 28 days. New type I collagen mRNA synthesis was followed by in situ hybridization, while the accumulation of new collagen types III, V, VI, XII, and XIV was followed by immunohistochemistry. All the collagen detected in the pores of the implant were newly deposited at various times after implantation and were not due to any pre‐existing dermal collagen that may have been present around the implant. Collagen deposition was seen initially surrounding the implant and, with time, was seen to infiltrate within its pores. In situ hybridization showed that the majority of infiltrating cells had switched on mRNA that coded for type I collagen production. Histology showed that cellular infiltration increased with time, accompanied by increasing collagen deposition. The deposition of different collagen types happened at different rates. The type V and VI collagens preceded the major interstitial collagens in the newly deposited tissue, although at longer time points, detection of type V collagen appeared to decrease. After disruption of the interstitial collagens with enzyme, the “masked” type V collagen was clearly still visible by immunohistochemistry. Little type XII collagen could be seen within the porous mesh, although it was seen in the surrounding tissues. By contrast, type XIV was seen throughout the porous structure of the implanted mesh, with less being visible outside the material where type XII was more abundant. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3550–3555, 2014.
Indigenously produced polyhydroxyalkanoate based co‐polymer as cellular supportive biomaterial
Authors: Shabna A. , Saranya V. , Malathi J. , Shenbagarathai R. , Madhavan H. N.
Published: November 2013

The focus of this study was to evaluate the growth of the cells on a scaffold based on novel polyhydroxyalkanoate (PHA) (Polyhydroxy propionate copoly hydroxy ocatadecanoate copolymer), derived from a mutant strain of Pseudomonas sp. Naive PHA was also blended with several biodegradable polymeric materials (PEG, PLA, and MMT) to improve the scaffold properties. Protein adsorption study was done to evaluate the capability of scaffolds for cellular interaction. PHA:PEG blended scaffold showed better adsorption than others. 3T3 fibroblast cultures on various polymers were equally viable when compared with control culture except for the blend PHA:MMT by CCK 8 kit. MTT assay, performed with the continuous cultures HeLa, HEp‐2, Vero, and McCoy on the polymer blends, supported the above finding. Among the blends PHA:PEG showed increased viability and was selected for further studies. Cell proliferation assay with colorimetric BrdU ELISA kit showed increase in cell proliferation over the matrix PHA:PEG than that of control. There were no observable morphological changes of continuous cells grown over matrix PHA:PEG when observed by phase contrast microscopy. HEp‐2 cells were enclosed within the matrix when analyzed by SEM. The current study states that the scaffold prepared by using the indigenous PHA in combination with PEG supports cell growth better than the conventional plastic surface. PHA:PEG would be a promising material for tissue engineering. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3470–3476, 2014.
Chondrogenic differentiation of mesenchymal stem cells in a hydrogel system based on an enzymatically crosslinked tyramine derivative of hyaluronan
Authors: Dvořáková Jana , Kučera Lukáš , Kučera Jan , Švík Karol , Foglarová Marcela , Muthný Tomáš , Pravda Martin , Němcová Miroslava , Velebný Vladimír , Kubala Lukáš
Published: November 2013

Hyaluronan‐based tissue substitutes are promising materials in cartilage reconstruction surgery. Herein, the chondrogenesis of human mesenchymal stem cells (MSC) in a hydrogel based on a tyramine derivative of hyaluronan crosslinked by hydrogen peroxidase (HA‐TA) was evaluated. Human MSC seeded in the scaffold were incubated in standard chondrogenic medium and medium enriched with bone morphogenetic protein‐6 (BMP6). Cell viability, the gene expression of selected markers (collagen type II, aggrecan, SOX9, collagen type X, and osteopontin), and the histological characteristics were examined during three weeks of in vitro cultivation. The tissue reaction of both unseeded and MSC seeded HA‐TA scaffolds were tested in vivo after subcutaneous application in rats for 12 weeks. The data showed that cells resisted the process of crosslinking and remained viable for the whole time while exhibiting changes in cell organization. Human MSC cultivated in HA‐TA hydrogel expressed genes of both chondrogenic and osteogenic differentiation and the addition of BMP6 revealed a tendency to potentiate both processes. Histological analysis of HA‐TA in vivo implants did not reveal a chronic inflammatory reaction. In both cases, in vivo HA‐TA implants were continuously degraded and MSC‐seeded hydrogels tended to form clusters similar to in vitro samples. In conclusion, MSC chondrogenic differentiation may proceed in a HA‐TA scaffold that is biocompatible. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 102A: 3523–3530, 2014.
Search for varicella zoster virus DNA in saliva of healthy individuals aged 20–59 years
Authors: Birlea Marius , Cohrs Randall J. , Bos Nathan , Mehta Satish K. , Pierson Duane L. , Gilden Don
Published: November 2013

All neurological and ocular complications of varicella zoster virus (VZV) reactivation can occur without rash. Virological verification requires detection of VZV DNA or anti‐VZV IgG antibody in cerebrospinal fluid (CSF), or anti‐VZV IgM antibody in serum or CSF. If VZV were readily detected in other tissue in patients with neurological disease without rash and found to correlate with tests listed above, more invasive tests such as lumbar puncture might be obviated. Saliva is a potential source of VZV DNA. To study the potential diagnostic value of detecting VZV DNA in saliva from patients with neurological disease, saliva of healthy adults was searched for VZV DNA. A single saliva sample obtained by passive drool was centrifuged at 16,000g for 20 min. DNA was extracted from the supernatant and cell pellet and examined in triplicate for VZV DNA by real time PCR. A single random saliva sample from 80 healthy men and women aged 20–59 years revealed no VZV DNA (Table ), but was uniformly positive for cell (GAPdH) DNA. Because VZV DNA was not found in a random saliva sample from 80 individuals 20–59‐year‐old, a VZV‐positive sample during neurologic disease may have potential significance. Further studies will determine whether VZV DNA in saliva correlates with VZV DNA or anti‐VZV antibody in CSF in patients with neurological disease. J. Med. Virol. 86:360–362, 2014. © 2013 Wiley Periodicals, Inc.
Polymorphisms in human leukocyte antigens, human platelet antigens, and cytokine genes in hantavirus cardiopulmonary syndrome patients from Ribeirão Preto, Brazil
Authors: Borges Alessandra Abel , Donadi Eduardo Antonio , Campos Gelse Mazzoni , de Figueiredo Glauciane Garcia , Saggioro Fabiano Pinto , Badra Soraya Jabur , Deghaide Neifi Hassan Saloum , Figueiredo Luiz Tadeu Moraes
Published: November 2013

Hantavirus cardiopulmonary syndrome is a severe human disease associated with hantavirus infection. The clinical course of illness varies greatly among individuals, possibly due to viral and immunological elements and the influence of host genetic factors on clinical outcome. As the magnitude of immune activation has been associated with disease severity, polymorphisms in genes involved in the immune response that may affect the development of this syndrome were investigated. Polymorphisms in the TGF‐β, IL‐10, IL‐6, and IFN‐γ genes, human leukocyte antigens (HLA), and human platelet alloantigens (HPA) genes were investigated in 122 patients with Araraquara virus infection from Ribeirão Preto, Brazil. Patients were divided into two groups: hantavirus cardiopulmonary syndrome (HCPS group; n = 26) and hantavirus seropositive only (n = 96). The frequencies of HLA alleles, cytokines and platelet antigen genotypes were evaluated in both groups and compared to a control group. The data demonstrated no significant influence of the HLA alleles, HPA, IL‐6, and IL‐10 genotypes on susceptibility to hantavirus infection. However, the hantavirus seropositive group presented a significantly higher frequency of a polymorphism associated with a high IFN‐γ production than the HCPS group. In addition, a genotype associated with high TGF‐β production was found more frequently in individuals infected with hantavirus than in the control group. This phenotype was associated with a less intense thrombocytopenia in the HCPS group and may be protective against the most severe form of hantavirus disease. More studies are required to quantify further the influence of the high TGF‐β producer phenotype on the outcome of hantavirus infection. J. Med. Virol. 86:1962–1970, 2014. © 2013 Wiley Periodicals, Inc.
Association of a single nucleotide polymorphism in HOXB9 with developmental dysplasia of the hip: A case‐control study
Authors: Hao Zheng , Dai Jin , Shi Dongquan , Xu Zhihong , Chen Dongyang , Zhao Baocheng , Teng Huajian , Jiang Qing
Published: November 2013

Developmental dysplasia of the hip (DDH) is one of the most common skeletal disorders. It comprises a spectrum of abnormalities, including shallow acetabulum and decreased coverage of the femoral head. Genetic component plays a considerable role in the aetiology of DDH. HOXB9 may be involved in the aetiology and pathogenesis of DDH, as it plays an important role in the development of the limbs. Our objective was to evaluate whether single nucleotide polymorphisms (SNPs) of HOXB9 (rs2303486 and rs8844) were associated with DDH in Chinese population. The HOXB9 tag SNPs were genotyped in 460 DDH cases and 562 control subjects by Taqman assay, and their association was examined. rs8844 was not associated with DDH. rs2303486 was associated with DDH in the dominant genetic model (p = 0.037; odds ratio (OR) = 1.32; 95% confidence interval (CI) = 1.02–1.71). After stratification by sex, significant association of the dominant genetic model still existed in the female subjects (p = 0.015; OR = 1.46; 95% CI = 1.08–1.98), but not in the male subjects. After stratification by severity, we discovered an association with hip dislocation in the dominant model (p = 0.042; OR = 1.35; 95% CI = 1.01–1.80), but not with subluxation or instability. HOXB9 is associated with DDH in Chinese. © 2013 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 32:179–182, 2014.
Topological insulator as an optical modulator for pulsed solid‐state lasers
Authors: Yu Haohai , Zhang Han , Wang Yicheng , Zhao Chujun , Wang Baolin , Wen Shuangchun , Zhang Huaijin , Wang Jiyang
Published: November 2013

Topological insulators are states of quantum matter that have narrow topological nontrivial energy gaps and a large third‐order nonlinear optical response. The optical absorption of topological insulators can become saturated under strong excitation. In this work, with Bi2Se3 as an example, it was demonstrated that a topological insulator can modulate the operation of a bulk solid‐state laser by taking advantage of its saturable absorption. The result suggests that topological insulators are potentially attractive as broadband pulsed modulators for the generation of short and ultrashort pulses in bulk solid‐state lasers, in addition to other promising applications in physics and computing.
Bi‐directional organic light‐emitting diodes with nanoparticle‐enhanced light outcoupling
Authors: Chang Hong‐Wei , Lee Jonghee , Koh Tae‐Wook , Hofmann Simone , Lüssem Björn , Yoo Seunghyup , Wu Chung‐Chih , Leo Karl , Gather Malte C.
Published: November 2013

An effective method is presented for enhancing the outcoupling efficiency of translucent/bi‐directional organic light‐emitting diodes (TL/BD‐OLEDs) with a bottom indium tin oxide (ITO) anode and a top cathode comprised of a thin Ag layer covered with an organic capping layer. Upon insertion of a nanoparticle (NP)‐based scattering layer (NPSL) between the substrate and the ITO anode, the TL/BD‐OLEDs exhibit significantly enhanced external quantum efficiency (EQE) in both emission directions. Furthermore, the NPSL improves the color stability of the TL/BD‐OLEDs over a wide range of viewing angles. Simulations based on geometrical and statistical optics are performed to elucidate the mechanism by which the efficiency is enhanced and to establish strategies for further optimization. Simulations performed on the scattering layers with varying NP volume percentage reveal that the bottom‐side emission is governed by competition between waveguide‐mode extraction and backward scattering by NPs in the film, while the top‐side emission is largely dominated by the latter. Optimized bi‐directional OLEDs achieve a 1.64‐fold enhanced EQE compared to reference devices without NPSL.
Five‐cycle pulses near λ = 3 μm produced in a subharmonic optical parametric oscillator via fine dispersion management
Authors: Haakestad Magnus W. , Marandi Alireza , Leindecker Nick , Vodopyanov Konstantin L.
Published: November 2013

Five‐cycle (50 fs) mid‐IR pulses at 80‐MHz repetition rate are produced using a degenerate (subharmonic) optical parametric oscillator (OPO), synchronously pumped by an ultrafast 1560‐nm fiber laser. The effects of cavity dispersion and the length of a periodically poled lithium niobate (PPLN) gain element on the output spectrum and pulse duration are investigated by taking advantage of a very broad (∼ 1000 cm−1) gain bandwidth near the 3.1‐μm OPO degeneracy point. A new method of assessing the total OPO group delay dispersion across its entire spectrum is proposed, based on measuring spectral signatures of trace amounts of molecular gases injected into the OPO cavity.
Application of Complement Component 4d Immunohistochemistry to ABO-Compatible and ABO-Incompatible Liver Transplantation
Authors: Salah Adeeb , Fujimoto Masakazu , Yoshizawa Atsushi , Yurugi Kimiko , Miyagawa-Hayashino Aya , Sumiyoshi Shinji , Minamiguchi Sachiko , Uemoto Shinji , Maekawa Taira , Haga Hironori
Published: November 2013

Antibody-mediated rejection (AMR) is difficult to diagnose after ABO-compatible or ABO-identical (ABO-C) liver transplantation. To determine whether complement component 4d (C4d) immunostaining would be useful for diagnosing AMR, we compared the results of C4d immunohistochemistry for allograft biopsy samples with assays for anti-donor antibodies performed at the time of biopsy. One hundred fourteen patients with ABO-C grafts and 29 patients with ABO-incompatible (ABO-I) grafts were included. Linear C4d endothelial staining (identifiable with a 4× objective lens) or staining seen in 50% or more of the portal tracts was considered positive. Five of the 114 patients (4%) with ABO-C grafts and 15 of the 29 patients (52%) with ABO-I grafts showed C4d positivity. In the ABO-C cases, C4d positivity in late biopsy samples (≥30 days after transplantation) was associated with stage 2 or higher fibrosis (METAVIR score; P = 0.01) and with the presence of donor-specific anti–human leukocyte antigen DR antibodies (HLA-DR DSAs) with a mean fluorescence intensity > 5000 according to the Luminex single-antigen bead assay (P = 0.04). Conversely, the presence of HLA-DR DSAs was associated with the presence of stage 2 or higher fibrosis, acute cellular rejection, and C4d positivity. During the 2-year follow-up, neither C4d positivity nor HLA-DR DSAs were related to graft loss. Among ABO-I patients, C4d positivity was not associated with allograft dysfunction or fibrosis. Only 3 of the 15 C4d-positive patients (20%) showed periportal hemorrhagic edema, which could be a histological sign of AMR in ABO-I grafts, and they were the only cases associated with elevations in anti-donor A/B antibody titers. In conclusion, C4d endothelial positivity among ABO-C patients is an uncommon event that could be associated with chronic graft damage with or without clinical AMR. C4d positivity is common among ABO-I patients and may not be associated with allograft dysfunction if alloantibody titers are not elevated. Liver Transpl 20:200-209, 2014. © 2013 AASLD.
Prediction of ProteinProtein Interaction Pocket Using L‐Shaped PLS Approach and Its Visualizations by Generative Topographic Mapping
Authors: Hasegawa Kiyoshi , Funatsu Kimito
Published: November 2013

Proteinprotein interaction (PPI) pockets in a hostguest protein system were predicted using an L‐shaped partial least squares (LPLS) method. LPLS is an extension of standard PLS regression, where, in addition to response vector y and regressor matrix X, an extra data matrix Z is constructed which summarizes the background information on X. The regressor matrix X is a similarity matrix of Tanimoto coefficients of the paired fingerprints of pockets, while the background information Z constitutes eleven physico‐chemical and geometrical parameters for describing a pocket. The Boolean response vector y specifies whether each pocket is PPI or non‐PPI (indicated by 1 and 0, respectively). Constructing two LPLS models, we successfully predicted the PPI pockets of two protein clusters. Clusters 1 and 2 comprised the X‐ray crystal structures of protein‐peptide complexes and protein‐protein complexes, respectively. From the loading plots derived from each model, we could speculate the geometrical constraints of the PPI pockets. These two models are exclusively unique and it was validated by the cross‐prediction simulations. The PPI pockets of cluster 1 were projected onto 2D maps by generative topographic mapping (GTM) and the molecular lipophilic potentials (MLP). Among three examples, the MLP distributions were highly similar because the specimens shared the same p53 guest peptides. Contribution to the Autumn School of Chemoinformatics in Nara, Japan, November 27–28, 2013