bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous In Situ Quantification of Two Cellular Lipid Pools Using Orthogonal Fluorescent Sensors
Authors: Liu Shu‐Lin , Sheng Ren , O'Connor Matthew J. , Cui Yang , Yoon Youngdae , Kurilova Svetlana , Lee Daesung , Cho Wonhwa
Published: October 2014

Lipids regulate a wide range of biological activities. Since their local concentrations are tightly controlled in a spatiotemporally specific manner, the simultaneous quantification of multiple lipids is essential for elucidation of the complex mechanisms of biological regulation. Here, we report a new method for the simultaneous in situ quantification of two lipid pools in mammalian cells using orthogonal fluorescent sensors. The sensors were prepared by incorporating two environmentally sensitive fluorophores with minimal spectral overlap separately into engineered lipid‐binding proteins. Dual ratiometric analysis of imaging data allowed accurate, spatiotemporally resolved quantification of two different lipids on the same leaflet of the plasma membrane or a single lipid on two opposite leaflets of the plasma membrane of live mammalian cells. This new imaging technology should serve as a powerful tool for systems‐level investigation of lipid‐mediated cell signaling and regulation.
Over 10 000 Peptide Identifications from the HeLa Proteome by Using Single‐Shot Capillary Zone Electrophoresis Combined with Tandem Mass Spectrometry
Authors: Sun Liangliang , Hebert Alexander S. , Yan Xiaojing , Zhao Yimeng , Westphall Michael S. , Rush Matthew J. P. , Zhu Guijie , Champion Matthew M. , Coon Joshua J. , Dovichi Norman J.
Published: October 2014

Capillary zone electrophoresis (CZE)–tandem mass spectrometry (MS/MS) has recently attracted attention as a tool for shotgun proteomics. However, its performance for this analysis has so far fallen far below that of reversed‐phase liquid chromatography (RPLC)–MS/MS. The use of a CZE method with a wide separation window (up to 90 min) and high peak capacity (ca. 300) is reported. This method was coupled to an Orbitrap Fusion mass spectrometer through an electrokinetically pumped sheath‐flow interface for the analysis of complex proteome digests. Single‐shot CZE–MS/MS lead to the identification of over 10 000 peptides and 2100 proteins from a HeLa cell proteome digest in approximately 100 min. This performance is nearly an order of magnitude better than earlier CZE studies and is within a factor of two to four of the state‐of‐the‐art nano ultrahigh‐pressure LC system.
Short‐lived Phenoxyl Radicals Formed from Green‐Tea Polyphenols and Highly Reactive Oxygen Species: An Investigation by Time‐Resolved EPR Spectroscopy
Authors: Neshchadin Dmytro , Batchelor Stephen N. , Bilkis Itzhak , Gescheidt Georg
Published: October 2014

Polyphenols are effective antioxidants and their behavior has been studied in depth. However, a structural characterization of the species formed immediately upon hydrogen‐atom transfer (HAT), a key reaction of oxidative stress, has not been achieved. The reaction of catechin and green‐tea polyphenols with highly reactive O‐centered H‐abstracting species was studied at the molecular level and in real time by using time‐resolved electron paramagnetic resonance (EPR) spectroscopy. This mirrors the reaction of highly reactive oxygen species with polyphenols. The results show that all phenolic OH groups display essentially identical reactivity. Accordingly, there is no site specificity for HAT and initial antioxidative events are demonstrated to be largely ruled by statistical (entropic) factors.
Physiological Responses to Social and Nonsocial Stimuli in Neurotypical Adults With High and Low Levels of Autistic Traits: Implications for Understanding Nonsocial Drive in Autism Spectrum Disorders
Authors: Singleton Clarence J. , Ashwin Chris , Brosnan Mark
Published: October 2014

Researchers have suggested that the two primary cognitive features of autism spectrum disorder (ASD), a drive toward nonsocial processing and a reduced drive toward social processing, may be unrelated to each other in the neurotypical (NT) population and may therefore require separate explanations. Drive toward types of processing may be related to physiological arousal to categories of stimuli, such as social (e.g., faces) or nonsocial (e.g., trains). This study investigated how autistic traits in an NT population might relate to differences in physiological responses to nonsocial compared with social stimuli. NT participants were recruited to examine these differences in those with high vs. low degrees of ASD traits. Forty‐six participants (21 male, 25 female) completed the Autism Spectrum Quotient (AQ) to measure ASD traits before viewing a series of 24 images while skin conductance response (SCR) was recorded. Images included six nonsocial, six social, six face‐like cartoons, and six nonsocial (relating to participants' personal interests). Analysis revealed that those with a higher AQ had significantly greater SCR arousal to nonsocial stimuli than those with a low AQ, and the higher the AQ, the greater the difference between SCR arousal to nonsocial and social stimuli. This is the first study to identify the relationship between AQ and physiological response to nonsocial stimuli, and a relationship between physiological response to both social and nonsocial stimuli, suggesting that physiological response may underlie the atypical drive toward nonsocial processing seen in ASD, and that at the physiological level at least the social and nonsocial in ASD may be related to one another. Autism Res 2014, 7: 695–703. © 2014 International Society for Autism Research, Wiley Periodicals, Inc.
Study on the interaction between ligustrazine and 12‐tungstophosphoric acid using resonance Rayleigh scattering and resonance nonlinear scattering spectra, and its analytical applications
Authors: Li Junbo , Yang Xiaoli , Yang Jinxiang , Lai Lina
Published: October 2014

In an HCl medium (pH 1.5), ligustrazine (2,3,5,6‐tetramethylpyrazine, TMP) reacted with 12‐tungstophosphoric acid (TP) to form a 3 : 1 ion‐association complex. As a result, the intensities of resonance Rayleigh scattering (RRS), second‐order scattering (SOS) and frequency doubling scattering (FDS) were greatly enhanced and new scattering spectra appeared. The maximum RRS, SOS and FDS wavelengths of the ion‐association complexes were located at 379, 738 and 395 nm, respectively. The scattering intensity increments (ΔIRRS, ΔISOS and ΔIFDS) were directly proportional to the concentration of ligustrazine within certain ranges. The detection limits (3σ) of RRS, SOS and FDS were 1.6, 3.2 and 2.8 ng/mL. Optimal conditions for the RRS method and factors influencing the method were discussed, and the structure of the ion‐association complex and the reaction mechanism were investigated. Transmission electron microscopy (TEM) was used to characterize the structures of the ion‐association complex. Based on the ion‐association reaction and its spectral response, a rapid, simple and sensitive RRS method for the determination of TMP was developed. It was applied to the determination of TMP in tablet and urine samples with satisfactory results. Copyright © 2014 John Wiley & Sons, Ltd.
A combination of targeted toxin technology and the piggyBac‐mediated gene transfer system enables efficient isolation of stable transfectants in nonhuman mammalian cells
Authors: Sato Masahiro , Inada Emi , Saitoh Issei , Matsumoto Yuko , Ohtsuka Masato , Miura Hiromi , Nakamura Shingo , Sakurai Takayuki , Watanabe Satoshi
Published: October 2014

Isolation of cells harboring exogenous DNA is typically achieved by the introduction of plasmids, but its efficiency remains still low. In this study, we developed a novel strategy to obtain stable transfectants efficiently. Porcine embryonic fibroblasts were transfected with two plasmids: (i) pTransIEnd, which comprises the ubiquitous promoter, the piggyBac (PB) transposase gene, an internal ribosomal entry site, the Clostridium perfringens‐derived endo‐β‐galactosidase C (EndoGalC) gene, and a poly(A) tail and (ii) a PB‐based plasmid, termed pT‐EGFP, which contains enhanced green fluorescent protein (EGFP) expression unit flanked by PB acceptor sites. The PB transposase can accelerate the chromosomal integration of transposon vectors. EndoGalC expression results in removal of a cell surface α‐Gal epitope, which is specifically recognized by Bandeiraea simplicifolia isolectin‐B4 (IB4). Four days after transfection, cells were treated with IB4SAP (IB4 conjugated to saporin, which eliminates any α‐Gal epitope‐expressing cells) for a short period, followed by standard culture for approximately 10 days. Several colonies emerged, most of which were positive for EGFP expression and lacked TransIEnd. These results indicated that the proposed approach is useful and efficient for obtaining stable transfectants without the use of drug‐resistance genes, and offers a novel route for gene manipulation in cultured nonhuman mammalian cells.
Development and validation of a single HPLC method for determination of α‐tocopherol in cell culture and in human or mouse biological samples
Authors: Cimadevilla Henar M. , Hevia David , Miar Ana , Mayo Juan C. , Lombo Felipe , Sainz Rosa M.
Published: October 2014

A straightforward and common analytical method for α‐tocopherol (αT) determination in various biological samples, including plasma, red blood cells (RBC), tissues and cultured cell lines, was developed and validated, using a reverse phase‐chromatographic method (RP‐HPLC). Even though many chromatographic methods for αT determination have been reported, most of them require readjustment when applied to different types of samples. Thus, an effective and simple method for αT determination in different biological matrices is still necessary, specifically for translational research. This method was applied using a C18 column (250 × 4.6 mm, 5 µm particle size) under isocratic elution with MeOH:ACN:H2O (90:9:1 v/v/v) at a flow rate of 1 mL/min and detected using photodiode array at 293 nm. Linearity (r >0.9997) was observed for standard calibration with inter‐ and intraday variation of standard <4%. Lower limits of detection and quantification for αT in this assay were 0.091 and 0.305 µg/mL respectively. Validation proved the method to be selective, linear, accurate and precise. The method was successfully applied in great variety of biological samples, that is, human and mouse plasma, RBCs, murine tissues and human/mouse/rat cultured cell lines. More importantly, a single protocol of extraction and detection can be applied, making this method very convenient for standardization of different types of samples. Copyright © 2014 John Wiley & Sons, Ltd.
Directed Evolution of a Formate Dehydrogenase for Increased Tolerance to Ionic Liquids Reveals a New Site for Increasing the Stability
Authors: Carter Julie L. L. , Bekhouche Mourad , Noiriel Alexandre , Blum Loïc J. , Doumèche Bastien
Published: October 2014

The formate dehydrogenase (FDH) from Candida boidinii is a well‐known enzyme in biocatalysis for NADH regeneration. Nevertheless, it has low activity in a water‐miscible ionic liquid (1,3‐dimethylimidazolium dimethyl phosphate, [MMIm][Me2PO4]). In this work, this enzyme was subjected to directed evolution by using error‐prone PCR, and a mutant (N187S/T321S) displaying higher activity was obtained following selection based on the formazan‐based colorimetric assay. The mutation N187S is responsible for improved activity both in aqueous solution and in [MMIm][Me2PO4], through an enhancement of the kcat value by a factor of 5.8. Fluorescence experiments performed in the presence of a quenching agent revealed that the mutant does not unfold in the presence of 50 % (v/v) [MMIm][Me2PO4] whereas the wild‐type enzyme does. Molecular modelling revealed that the mutation is located at the monomer–monomer interface and causes an increase in the pKa of residue E163 from 4.8 to 5.5. Calculation of the pKa of this residue in other microbial FDHs showed that thermostable FDHs have a highly basic glutamate at this position (pKa up to 6.2). We have identified a new site for improving FDH thermostability and tolerance to ionic liquids, and it is linked to the local charge of the enzymes in this class.
Evidences of Intracrystalline Mesostructured Porosity in Zeolites by Advanced Gas Sorption, Electron Tomography and Rotation Electron Diffraction
Authors: Garcia‐Martinez Javier , Xiao Changhong , Cychosz Katie A. , Li Kunhao , Wan Wei , Zou Xiaodong , Thommes Matthias
Published: October 2014

The front cover artwork for Issue 11/2014 is a collaboration between Rive Technology, Inc. (USA), Stockholm University (Sweden), Quantachrome Instruments (USA), and the University of Alicante (Spain), The image shows that a new family of materials, namely mesostructured zeolites, bridges the gap between conventional (microporous) zeolites and surfactant‐templated (mesoporous) solids. See the Full Paper itself on page http://dx.doi.org/10.1002/cctc.201402499.
Electron Transport through Early Exponential‐Phase Anode‐Grown Geobacter sulfurreducens Biofilms
Authors: Strycharz‐Glaven Sarah M. , Roy Jared , Boyd Darryl , Snider Rachel , Erickson Jeffrey S. , Tender Leonard M.
Published: October 2014

Geobacter sulfurreducens biofilms were grown to early exponential phase (i.e. the point at which the catalytic current first begins to increase) on interdigitated microelectrode arrays (IDAs), resulting in the formation of sparse cell clusters surrounded by extracellular polymeric substance (EPS). Continuous domains of EPS (defined here to include extracellular materials including filaments), but not cell clusters, were observed to bridge the gaps between adjacent electrode bands. Electrochemical gate measurements revealed electrical continuity between adjacent IDA electrode bands, indicating that extracellular electron transport (EET) occurs through the EPS. The dependency of the source‐drain current on the gate potential is peak shaped, which is consistent with EPS acting as a redox conductor. The gate potential at which the maximum source‐drain current occurs is approximately 0.13 V more positive than that for stationary‐phase biofilms, indicating that redox cofactors involved in EET at the early exponential phase are different to those at the stationary phase.
High‐Resolution Imaging of the Initial Stages of Oxidation of Cu(111) with Scanning Electrochemical Potential Microscopy
Authors: Traunsteiner Christoph , Tu Kaiyang , Kunze‐Liebhäuser Julia
Published: October 2014

Scanning electrochemical potential microscopy (SECPM) is a scanning probe technique for the detection of the electrochemical double‐layer (EDL) potential of a given working electrode (WE). We report the first high‐resolution imaging of the OH adsorbate structure formed on a Cu(111) WE in alkaline solution with SECPM, which reveals a structural parameter of (0.60±0.04) nm that is in excellent agreement with that found with electrochemical scanning tunneling microscopy. The origin of the potential used as a feedback signal in SECPM mode is discussed, focusing on leakage currents detected in the SECPM setup, faradaic reactions in the electrolyte, and electron‐tunneling processes between the tip and the WE. At potential set‐points that are typical for SECPM measurements, the potential detected with the tip is found to originate from a tunneling current. Therefore, the images recorded with SECPM cannot deliver information on the EDL potential at the WE surface in the present case.
1,n‐Hydrogen‐Atom Transfer (HAT) Reactions in Which n≠5: An Updated Inventory
Authors: Nechab Malek , Mondal Shovan , Bertrand Michèle P.
Published: October 2014

Hydrogen‐atom transfer (HAT) counts amongst the most widely investigated routes to carbon‐centered radicals. Intramolecular processes involving 1,5‐HAT are widespread to promote regioselective radical “CH activation”. The aim of this review is to draw up a comprehensive inventory of the less commonly encountered 1,n‐radical translocations (n≠5) with the aim to update this topic with the most recent relevant data.
A Highly Selective Two‐Photon Fluorescent Probe for Detection of Cadmium(II) Based on Intramolecular Electron Transfer and its Imaging in Living Cells
Authors: Shi Zhaohua , Han Qingxin , Yang Lizi , Yang Huan , Tang Xiaoliang , Dou Wei , Li Zhiqi , Zhang Yange , Shao Yongliang , Guan Liping , Liu Weisheng
Published: October 2014

A new quinoline‐based probe was designed that shows one‐photon ratiometric and two‐photon off–on changes upon detecting Cd2+. It exhibits fluorescence emission at 407 nm originating from quinoline groups in Tris‐HCl (25 mM, pH 7.40), H2O/EtOH (8:2, v/v). Coordination with Cd2+ causes quenching of the emission at 407 nm and simultaneously yields a remarkable redshift of the emission maximum to 500 nm with an isoemissive point at 439 nm owing to an intramolecular charge‐transfer mechanism. Thus, dual‐emission ratiometric measurement with a large redshift (Δλ=93 nm) and significant changes in the ratio (F500/F439) of the emission intensity (R/R0 up to 27) is established. Moreover, the sensor H2L displays excellent selectivity response, high sensitive fluorescence enhancement, and strong binding ability to Cd2+. Coordination properties of H2L towards Cd2+ were fully investigated by absorption/fluorescence spectroscopy, which indicated the formation of a 2:1 H2L/Cd2+ complex. All complexes were characterized by X‐ray crystallography, and TD‐DFT calculations were performed to understand the origin of optical selectivity shown by H2L. Two‐photon fluorescence microscopy experiments have demonstrated that H2L could be used in live cells for the detection of Cd2+.
Picolinamides as Effective Ligands for Copper‐Catalysed Aryl Ether Formation: Structure–Activity Relationships, Substrate Scope and Mechanistic Investigations
Authors: Sambiagio Carlo , Munday Rachel H. , Marsden Stephen P. , Blacker A. John , McGowan Patrick C.
Published: October 2014

The use of picolinic acid amide derivatives as an effective family of bidentate ligands for copper‐catalysed aryl ether synthesis is reported. A fluorine‐substituted ligand gave good results in the synthesis of a wide range of aryl ethers. Even bulky phenols, known to be very challenging substrates, were shown to react with aryl iodides with excellent yields using these ligands. At the end of the reaction, the first examples of end‐of‐life Cu species were isolated and identified as CuII complexes with several of the anionic ligands tested. A preliminary mechanistic investigation is reported that suggests that the substituents on the ligands might have a crucial role in determining the redox properties of the metal centre and, consequently, its efficacy in the coupling process. An understanding of these effects is important for the development of new efficient and tunable ligands for copper‐based chemistry.
Formal Total Synthesis of (−)‐Taxol through Pd‐Catalyzed Eight‐Membered Carbocyclic Ring Formation
Authors: Hirai Sho , Utsugi Masayuki , Iwamoto Mitsuhiro , Nakada Masahisa
Published: October 2014

A formal total synthesis of (−)‐taxol by a convergent approach utilizing Pd‐catalyzed intramolecular alkenylation is described. Formation of the eight‐membered carbocyclic ring has been a problem in the convergent total synthesis of taxol but it was solved by the Pd‐catalyzed intramolecular alkenylation of a methyl ketone affording the cyclized product in excellent yield (97 %), indicating the high efficiency of the Pd‐catalyzed intramolecular alkenylation. Rearrangement of the epoxy benzyl ether through a 1,5‐hydride shift, generating the C3 stereogenic center and subsequently forming the C1–C2 benzylidene, was discovered and utilized in the preparation of a substrate for the Pd‐catalyzed reaction.
Reactions of the Donor‐Stabilized Silylene Bis[N,N′‐diisopropyl‐benzamidinato(−)]silicon(II) with Brønsted Acids
Authors: Junold Konstantin , Sinner Katharina , Baus Johannes A. , Burschka Christian , Fonseca Guerra Célia , Bickelhaupt F. Matthias , Tacke Reinhold
Published: October 2014

Reaction of the donor‐stabilized silylene 1 (which is three‐coordinate in the solid state and four‐coordinate in solution) with [HMCp(CO)3] (M=Mo, W; Cp=cyclopentadienyl) leads to the cationic five‐coordinate silicon(IV) complexes 2 and 3, respectively, and reaction of 1 with CH3COOH yields the neutral six‐coordinate silicon(IV) complex 4. Compounds 2–4 were structurally characterized by crystal structure analyses and multinuclear NMR spectroscopic studies in the solid state and in solution. The formation of 2–4 can be formally described in terms of a Brønsted acid/base reaction, coupled with a redox process (SiII→SiIV, H+→H−).
Combining Experimental and Computational Studies to Understand and Predict Reactivities of Relevance to Homogeneous Catalysis
Authors: Tsang Althea S.‐K. , Sanhueza Italo A. , Schoenebeck Franziska
Published: October 2014

This article showcases three major uses of computational chemistry in reactivity studies: the application after, in combination with, and before experiment. Following a brief introduction of suitable computational tools, challenges and opportunities in the implementation of computational chemistry in reactivity studies are discussed, exemplified with selected case studies from our and other laboratories.
Methyl Substitution Regulates the Enantioselectivity of Supramolecular Complex Binding to Human Telomeric G‐Quadruplex DNA
Authors: Xu Bailu , Zhao Chuanqi , Chen Yong , Tateishi‐Karimata Hisae , Ren Jinsong , Sugimoto Naoki , Qu Xiaogang
Published: October 2014

Chiral supramolecular compounds with substituents at different positions show different binding properties with human telomeric G‐quadruplex DNA. These different positions of methyl substitution in chiral supramolecular compounds can modulate their enantioselectivity and structural preference when binding with human telomeric G‐quadruplex DNA.
Enantiopure Laterally Functionalized Alleno–Acetylenic Macrocycles: Synthesis, Chiroptical Properties, and Self‐Assembly in Aqueous Media
Authors: Tzirakis Manolis D. , Alberti Mariza N. , Weissman Haim , Rybtchinski Boris , Diederich François
Published: October 2014

A family of shape‐persistent alleno–acetylenic macrocycles (SPAAMs), peripherally decorated with structurally diverse pendant groups, has been synthesized and characterized in enantiomerically pure form. Their electronic circular dichroism (ECD) spectra feature a strong chiroptical response, which is more than two times higher than for open‐chain tetrameric analogues. A water‐soluble oligo(ethylene glycol)‐appended SPAAM undergoes self‐assembly in aqueous solution. Morphology studies by cryogenic transmission electron microscopy (cryo‐TEM) revealed the formation of aggregates with fibrous fine structures that correspond to tubular, macrocyclic stacks.
A 3D 12‐Ring Zeolite with Ordered 4‐Ring Vacancies Occupied by (H2O)2 Dimers
Authors: Liang Jie , Su Jie , Wang Yingxia , Chen Yanping , Zou Xiaodong , Liao Fuhui , Lin Jianhua , Sun Junliang
Published: October 2014

A germanate zeolite, PKU‐14, with a three‐ dimensional large‐pore channel system was structurally characterized by a combination of high‐resolution powder X‐ray diffraction, rotation electron diffraction, NMR, and IR spectroscopy. Ordered Ge4O4 vacancies inside the [46.612] cages has been found in PKU‐14, in which a unique (H2O)2 dimer was located at the vacancies and played a structure‐directing role. It is the first time that water clusters are found to be templates for ordered framework vacancies.
Management trends in stage I testicular seminoma: Impact of race, insurance status, and treatment facility
Authors: Gray Phillip J. , Lin Chun Chieh , Sineshaw Helmneh , Paly Jonathan J. , Jemal Ahmedin , Efstathiou Jason A.
Published: October 2014

BACKGROUND

The management of stage I testicular seminoma is evolving rapidly. This study examined modern trends in the management of stage I testicular seminoma and the effects of sociodemographic factors on therapy choice.

METHODS

Data from the National Cancer Data Base on 34,067 patients with stage I testicular seminoma who were treated between 1998 and 2011 were analyzed. Multivariate logistic regression models were used to assess factors associated with adjuvant management strategies.

RESULTS

For patients with stage IA/B testicular seminoma, rates of observation after orchiectomy increased from 23.7% to 54.0%, the receipt of adjuvant chemotherapy increased from 1.5% to 16.0%, and the receipt of radiotherapy decreased from 70.8% to 28.8%. A similar pattern was seen in stage IS testicular seminoma, although these patients were more likely to receive adjuvant radiotherapy/chemotherapy (60.7% vs 44.8% for stage IA/B in 2011, P < .001). For patients with stage IA/B testicular seminoma, observation after orchiectomy was more common in racial minorities (odds ratio [OR] for blacks vs whites, 1.31, P < .001; OR for Hispanics vs whites, 1.39, P < .001) and in the uninsured (OR for uninsured vs privately insured, 1.33, P < .001) and less common at community centers (OR for community centers vs National Cancer Institute–designated cancer centers, 0.80, P = .044). In those with stage IA/B testicular seminoma who received adjuvant radiotherapy/chemotherapy, the receipt of chemotherapy was more common at academic centers and for patients with nonprivate insurance.

CONCLUSIONS

Postorchiectomy observation in stage I testicular seminoma has increased significantly in recent years, as has the receipt of chemotherapy, whereas the receipt of radiotherapy has declined, particularly at academic centers. Race, insurance status, and facility type are strongly associated with the choice of adjuvant management. Cancer 2015;121:681–687. © 2014 American Cancer Society.
Dark‐Field‐Based Observation of Single‐Nanoparticle Dynamics on a Supported Lipid Bilayer for In Situ Analysis of Interacting Molecules and Nanoparticles
Authors: Lee Young Kwang , Kim Sungi , Nam Jwa‐Min
Published: October 2014

Observation of single plasmonic nanoparticles in reconstituted biological systems allows us to obtain snapshots of dynamic processes between molecules and nanoparticles with unprecedented spatiotemporal resolution and single‐molecule/single‐particle‐level data acquisition. This Concept is intended to introduce nanoparticle‐tethered supported lipid bilayer platforms that allow for the dynamic confinement of nanoparticles on a two‐dimensional fluidic surface. The dark‐field‐based long‐term, stable, real‐time observation of freely diffusing plasmonic nanoparticles on a lipid bilayer enables one to extract a broad range of information about interparticle and molecular interactions throughout the entire reaction period. Herein, we highlight important developments in this context to provide ideas on how molecular interactions can be interpreted by monitoring dynamic behaviors and optical signals of laterally mobile nanoparticles.
Forced Folding of a Disordered Protein Accesses an Alternative Folding Landscape
Authors: Moosa Mahdi Muhammad , Ferreon Allan Chris M. , Deniz Ashok A.
Published: October 2014

Intrinsically disordered proteins (IDPs) are involved in diverse cellular functions. Many IDPs can interact with multiple binding partners, resulting in their folding into alternative ligand‐specific functional structures. For such multi‐structural IDPs, a key question is whether these multiple structures are fully encoded in the protein sequence, as is the case in many globular proteins. To answer this question, here we employed a combination of single‐molecule and ensemble techniques to compare ligand‐induced and osmolyte‐forced folding of α‐synuclein. Our results reveal context‐dependent modulation of the protein′s folding landscape, suggesting that the codes for the protein′s native folds are partially encoded in its primary sequence, and are completed only upon interaction with binding partners. Our findings suggest a critical role for cellular interactions in expanding the repertoire of folds and functions available to disordered proteins.
Selenium–Selenium Bond Cleavage of Diaryl Diselenide Radical Anions During Pulse Radiolysis
Authors: Tojo Sachiko , Fujitsuka Mamoru , Ouchi Akihiko , Majima Tetsuro
Published: October 2014

A seleniumselenium σ‐bond (SeSe) cleavage of a diaryl diselenide radical anion (ArSeSeAr.−) was investigated by absorption measurements during the γ radiolysis and pulse radiolysis in 2‐methyltetrahydrofuran. A di‐α‐naphthyl diselenide radical anion (αNpSeSeαNp.−) in which an unpaired electron is localized in the SeSe σ* orbital between both Se atoms with an elongated SeSe bond showed an absorption band at 440 nm at 77 K. Upon increasing temperature, the absorption band at 440 nm shifted to 540 nm, thus suggesting that an unpaired electron is delocalized over two naphthalene rings and the SeSe bond. The disappearance of the absorption band at 540 nm and formation of absorption bands at 420, 620, and 690 nm assigned to the α‐naphthylselenyl radical were observed during the pulse radiolysis of αNpSeSeαNp, thus indicating that the SeSe bond cleavage occurred in αNpSeSeαNp.−. The relationship between the SeSe bond cleavage and delocalization of the unpaired electron in ArSeSeAr.− is discussed.
Schwannoma including epithelial elements mimicking pleomorphic adenoma of the submandibular gland on fine‐needle cytology: The first case report
Authors: Tarjan Gabor
Published: October 2014

Although most salivary gland tumors can be diagnosed accurately on fine‐needle aspiration, cytological evaluation of spindle cell lesions, including schwannomas, still poses a challenge. In salivary gland aspirates, the most important mimickers of schwannomas are the common pleomorphic adenomas/mixed tumors since these may yield abundant spindle‐shaped myoepithelial cells and only scant epithelial cells. Therefore, in spindle cell‐rich aspirates from the head and neck, diligent search for epithelial cells is recommended. Their presence traditionally favors pleomorphic adenoma and argues against a schwannoma. Herein, however, we report, for the first time, a schwannoma with epithelial elements (glandular schwannoma) in the submandibular gland, demonstrating that the presence of epithelial cells in a spindle cell‐rich aspirate may not always exclude a schwannoma. Diagn. Cytopathol. 2015;43:395–398. © 2014 Wiley Periodicals, Inc.
Bladder aspergillosis detected by urine cytology
Authors: Martínez‐Girón Rafael , Martínez‐Torre Santiago , Mosquera‐Martínez Joaquín
Published: October 2014

Bladder aspergillosis is an unusual infection. We report the case of a 79‐year‐old man with clinical records of transitional cell carcinoma diagnosed 5 years ago. The presence of a fruiting body and septate hyphae in urine cytological smears were the key for a final diagnosis of fungal bladder infection caused by Aspergillus niger. Diagn. Cytopathol. 2015;43:403–406. © 2014 Wiley Periodicals, Inc.
Significant enhancement of 11‐Hydroxy‐THC detection by formation of picolinic acid esters and application of liquid chromatography/multi stage mass spectrometry (LC‐MS3): Application to hair and oral fluid analysis
Authors: Thieme Detlef , Sachs Ulf , Sachs Hans , Moore Christine
Published: October 2014

Formation of picolinic acid esters of hydroxylated drugs or their biotransformation products is a promising tool to improve their mass spectrometric ionization efficiency, alter their fragmentation behaviour and enhance sensitivity and specificity of their detection. The procedure was optimized and tested for the detection of cannabinoids, which proved to be most challenging when dealing with alternative specimens, for example hair and oral fluid. In particular, the detection of the THC metabolites hydroxyl‐THC and carboxy‐THC requires ultimate sensitivity because of their poor incorporation into hair or saliva. Both biotransformation products are widely accepted as incorporation markers to distinguish drug consumption from passive contamination. The derivatization procedure was carried out by adding a mixture of picolinic acid, 4‐(dimethylamino)pyridine and 2‐methyl‐6‐nitrobenzoic anhydride in tetrahydrofuran/triethylamine to the dry extraction residues. Resulting derivatives were found to be very stable and could be reconstituted in aqueous or organic buffers and subsequently analyzed by liquid chromatography‐mass spectrometry (LC‐MS). Owing to the complex consecutive fragmentation patterns, the application of multistage MS3 proved to be extremely useful for a sensitive identification of doubly picolinated hydroxy‐THC in complex matrices. The detection limits – estimated by comparison of corresponding signal‐to‐noise ratios – increased by a factor of 100 following picolination. All other species examined, like cannabinol, THC, cannabidiol, and carboxy‐THC, could also be derivatized exhibiting only moderate sensitivity improvements. The assay was systematically tested using hair samples and exemplarily applied to oral fluid. Concentrations of OH‐THC identified in THC‐positive hair samples ranged from 0.02 to 0.29pg/mg. Copyright © 2014 John Wiley & Sons, Ltd.
Role of Side‐Chain Bioisosteres in Determining the Binding Affinity of Click Chemistry Derived RGD Peptidomimetics to αvβ3 Integrin
Authors: Fabbrizzi Pierangelo , Menchi Gloria , Raspanti Silvia , Guarna Antonio , Trabocchi Andrea
Published: October 2014

Triazole‐containing Arg‐Gly‐Asp (RGD) peptidomimetics capable of interacting with αvβ3 integrin were developed through click chemistry. The role of the diverse range of guanidine bioisosteres for the arginine mimetic moiety was evaluated in vitro together with different appendages on the aspartic acid side of the peptidomimetic. The corresponding azides and alkynes were constructed through the application of simple modular reactions. Integrin binding assays allowed the best guanidine bioisostere for binding activity to be selected; the aromatic ring at the azide fragment bearing the aspartic acid moiety proved to be unnecessary. Molecular modelling calculations of a hit compound showed that the triazole and 2‐aminopyridine rings were involved in important π‐stacking interactions with Tyr178.
Solid Mixed‐Metal‐Oxide Catalysts for Biodiesel Production: A Review
Authors: Chang Fei , Zhou Quan , Pan Hu , Liu Xiao‐Fang , Zhang Heng , Xue Wei , Yang Song
Published: October 2014

With the rapid economic development and increasing depletion of petroleum‐derived diesel, survival environment of the human has been a serious threat. Therefore, it is necessary to seek green, environmentally friendly, and renewable energy candidates, for which biodiesel fuel has been developed as a promising candidate for energy accommodation. Currently, the most applied approach for the production of biodiesel involves the esterification and/or transesterification reaction. Among various catalytic processes, heterogeneous catalysts are promising and receiving increasing attention due to the easy separation of products and catalysts as well as the high‐purity glycerine (glycerol) byproduct that avoids significant waste emissions and effectively reduces the environmental pollution. In this Review, an attempt is being made to review different types of catalytic systems mediated by solid mixed metal oxides for biodiesel production.
Structuring and Governing Alliances: New Directions for Research
Authors: Contractor Farok J. , Reuer Jeffrey J.
Published: October 2014

The purpose of this article is to identify a future research agenda relating to the structure and governance of international alliances. Despite emerging research that is being carried out on topics related to the structuring, management, and governance of domestic and international collaborations, much remains unknown and warrants future work. The new directions in alliance research partially stem from the recent greater availability of databases that contain actual contract details. We also relate some of the contributions of the articles in the special issue to the research agenda we are calling for.
Synergistic effect of sustained release of growth factors and dynamic culture on osteoblastic differentiation of mesenchymal stem cells
Authors: Porta Giovanna Della , Nguyen Bao‐Ngoc B. , Campardelli R. , Reverchon Ernesto , Fisher John P.
Published: October 2014

Microparticles have been utilized as delivery vehicles of soluble factors to modify cellular behavior and therefore enhance tissue engineering regeneration. When incorporated into three‐dimensional systems, microparticles can provide geometrical and temporal controlled release of bioactive agents, such as growth factors (GFs) to surrounding cells. This study investigates the effect of GFs release from biopolymer microparticles on osteoblastic differentiation of human mesenchymal stem cells (hMSCs) encapsulated in calcium (Ca)‐alginate scaffolds while cultured in a tubular perfusion system bioreactor system. Empirical and deterministic models were used to demonstrate that poly(d,l‐lactic‐co‐glycolic acid)‐encapsulated GFs would result in a delayed release profile compared to GFs encapsulated into scaffolds directly. We hypothesized that the dual delivery of human bone‐morphogenetic protein 2 (hBMP2) and human vascular endothelial growth factor to cells in dynamic culture would provide molecular and physical cues to promote differentiation. Results indicated that the exposures of hBMP2 and dynamic flow are sufficient in enhancing the osteoblastic differentiation pathway compared to no GF addition and static culture. The GF delivery system in a dynamic flow environment resulted in a synergistic effect on osteoblastic differentiation of hMSCs. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 2161–2171, 2015.
Synthesis and Characterization of Metal Complexes (M = Al, Ti, W, Zn) Containing Pyrrole‐imine Ligands
Authors: Chen Yu‐Cai , Chiu Wan‐Ting , Hu Ting‐Jia , Lin Chia‐Her , Huang Jui‐Hsien
Published: October 2014

A series of metal compounds (M = Al, Ti, W, and Zn) containing pyrrole‐imine ligands have been prepared and structurally characterized. The reactions of AlMe3 with one and three equivs of pyrrole‐imine ligand [C4H3NH‐(2‐CH=NCH2Ph)] (1) generated aluminum compounds Al[C4H3N‐(2‐CH=NCH2Ph)]Me2 (2) and Al[C4H3N‐(2‐CH=NCH2Ph)]3 (3), respectively, in relatively high yield. Reacting two equivs of 1 with Ti(OiPr)4, W(NHtBu)2(=NtBu)2, or ZnMe2 afforded Ti[C4H3N‐(2‐CH=NCH2Ph)]2(OiPr)2 (4), W[C4H3N‐(2‐CH=NCH2Ph)]2(=NtBu)2 (5), and Zn[C4H3N‐(2‐CH=NCH2Ph)]2 (6), respectively. All the compounds have been characterized by 1H and 13C NMR spectroscopy. Compounds 3–6 have also been characterized by single‐crystal X‐ray structural analysis. The biting angles of pyrrole‐imine ligand with metals decrease and their related MNpyrrole and MNimine bond lengths increase in the order of 6, 3, 4, and 5.
Precisely Tailor the Longitudinal Localized Surface Plasmon Resonance of Gold Nanorods by Mild Oxidation with NaNO2
Authors: Jia Yanghui , Xiong Bin , Xu Dong , Yeung Edward S. , He Yan
Published: October 2014

In this work, we introduce a new method to precisely tailor the longitudinal localized surface plasmon resonance (LLSPR) wavelengths of gold nanorods (GNRs) through the use of NaNO2 as the oxidant. The effects of the concentrations of NaNO2, NH4Br and HCl on the reaction kinetics were investigated separately. To prepare GNRs with desired LLSPR wavelengths, equations were derived and were proved to be able to guide the tailoring of the LLSPR wavelengths through carefully tuning either the amount of NaNO2 or the reaction time. TEM characterizations performed on two representative sets of GNRs show that the GNRs obtained exhibited shortened lengths but unchanged diameter with good monodispersity. In particular, GNRs with targeted LLSPR at 800 nm, 750 nm, 700 nm and 650 nm were successfully synthesized with relative errors of only 1 %∼5 %. This method shall promote more applications of GNRs and may advance the synthesis of other metal nanoparticles.
Synthesis and Characterization of Melamine Formaldehyde Resins for Decorative Paper Applications
Authors: Ullah S. , Bustam M. A. , Ahmad F. , Nadeem M. , Naz M. Y. , Sagir M. , Shariff A. M.
Published: October 2014

Melamine‐formaldehyde (MF) resins of improved environmental compatibility were synthesized at different molar ratios, temperature and pH. Five molar ratios of melamine and formaldehyde: 35:65, 36.5:63.5, 38.3:61.7, 41.1:58.9 and 42.4:58.6 were used to synthesize the corresponding resins. The prepared samples were characterized by using molecular weight determination viscometery, field emission scanning electron microscopy and thermogravimetric analysis. It was noticed that the solid content in the resin increases with an increase in pH. The maximum percentage of the solid content (51 %) was obtained for pH of 8.5 and temperature range of 95–98 oC. The refractive index of the final product was found increasing with an increase of melamine concentration in the resin. A similar trend was noticed in molecular weight of the resins with an increase in monomer yield. The maximum molecular weight of 114218 was obtained from the sample synthesized with MF molar ratio of 42.4:58.6.
Forensic Applications of Portable X‐ray Fluorescence Spectrometer: Glass Samples
Authors: Cheng Shih‐Yuan , Chen Yung‐Fou , Huang Chih‐Chun Jean
Published: October 2014

Portable X‐ray Fluorescence Spectrometer (PXRF) is a qualitative and semi‐quantitative elemental analysis method. Recently, many researches using PXRF in the elemental analysis of materials have been reported. However, PXRF has not been extensively applied in forensic science, thus this study is devoted to demonstrate the utility of this technique through a rapid elemental analysis of glass samples for preliminary glass discrimination. Major elements such as Si, O, Ca, Al, and Na, as well as traces of Sr, Rb, K, Fe and Sn, in 25 glass samples were analyzed by PXRF. The amounts of some elements, such as Fe, K, Zr, and Sr, vary in different samples, while other elements, such as Th, are consistent in most tested glass samples. The results show that we can discriminate 98.31 % of 7,500 pair‐wise comparisons created from 25 glass samples. This study establishes PXRF as a new rapid method for the preliminary elemental analysis of glass, which shows a potential to be further applied for discrimination of glass samples in forensic field.
Recyclable Palladium Catalysts for the Heck/Sonogashira Reaction under Microwave‐assisted Thermomorphic Conditions
Authors: Lu Norman , Lin Kwan‐Yu , Li Chieh‐Keng , Kung Chih‐Chieh , Yeh Yun‐Peng , Cheng Yao‐Yi , Liu Ling‐Kang
Published: October 2014

The reaction of allyl palladium(II) chloride dimer and 4,4′‐bis(RfCH2OCH2)‐2,2′‐bpy, 1a–b, in the presence of AgOTf resulted in the synthesis of cationic palladium complex, [Pd(η3‐allyl)(4,4′‐bis‐(RfCH2OCH2)‐2,2′‐bpy)](OTf), 2a–b where Rf = C9F19 (a), C10F21 (b), respectively. The reaction of [PdCl2(CH3CN)] or K2PdCl4 with 1b, gave rise to the synthesis of [PdCl2(4,4′‐bis‐(C10F21CH2OCH2)‐2,2′‐bpy)], 3b. The quantitatively determined solubility curves of 2a–b and 3b in DMF indicated dramatic increase of solubility for 2a–b and 3b from −40 to 90 °C. The catalyst‐recoverable Pd‐catalyzed Heck/Sonogashira reactions were successfully achieved in DMF with microwave‐assistance. The cationic Pd‐catalyzed Heck arylation of methyl acrylate was selected to demonstrate the feasibility of recycling 2a–b using DMF as a solvent under microwave‐assisted thermomorphic conditions. At the end of each cycle, the product mixtures were cooled, and then the catalysts were recovered by decantation. The Heck arylation catalyzed by 2b under microwave‐assisted mode exhibited good recycling results favoring the trans product. To our knowledge, this is the first example of cationic Pd‐catalyzed Heck arylation under microwave‐assisted thermomorphic conditions. Additionally, recoverable 3b‐catalyzed Sonogashira reactions were also achieved successfully in DMF. The reactions under microwave‐assistance gave much better results in yield and in efficiency than that under conventional thermal heating.
A Mild and Simple One‐pot Synthesis of 2‐Substituted Benzimidazole Derivatives Using DDQ as an Efficient Oxidant at Room Temperature
Authors: Naeimi Hossein , Babaei Zahra
Published: October 2014

A series of 2‐substituted benzimidazoles were prepared through one‐pot reaction of o‐phenylenediamine with various aryl aldehydes in the presence of 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone (DDQ) in acetonitrile as solvent at room temperature. The reactions were smoothly preceded in excellent yields and short reaction times with an easy work‐up. The pure benzimidazoles as products were confirmed and characterized by physical and spectral data.
Electrochemical Sensor for Arabinose Based on Template‐free Pb/Cd Branched Nanorods on Glassy Carbon Electrode
Authors: Farkhondeh Golay , Sabzi Reza E.
Published: October 2014

In this paper, the electrochemical behavior of glassy carbon electrodes modified with Cd/Pb (GC/Cd/Pb) branched nanorodes (NRs) was studied using cyclic voltammetry technique. The obtained results showed that the branched nanorods of Cd/Pb can be readily prepared without any templates. The modified electrode was characterized using scanning electron microscopy (SEM), energy dispersive X‐ray analysis (EDAX) and electrochemical impedance spectroscopy (EIS) techniques. The electrocatalytic behavior of GC/Cd/Pb electrode showed an increase in oxidation signal of arabinose by increasing its concentration. The catalytic current was linearly related to arabinose concentration in the range of 0.6 to 6.8 μM with a limit of detection 0.2 μM.
Isolation and identification of allelochemicals produced by B. sonorensis for suppression of charcoal rot of Arachis hypogaea L.
Authors: Pandya Urja , Saraf Meenu
Published: October 2014

Bacillus sonorensis MBCU2 isolated from vermicompost‐amended soil from Gujarat, India showed most antagonistic activity against Macrophomina phaseolina by dual culture screening. The culture supernatant of MBCU2 completely suppressed the mycelia growth of pathogen, indicating that suppression was due to the presence of allelochemicals in the culture filtrate. Results of scanning electron microscopy revealed that MBCU2 caused morphological alteration in mycelia of M. phaseolina as evident by hyphal lysis and perforation. Lipopeptides (iturin A and surfactin) produced by MBCU2 were detected and identified by MALDI‐TOF‐MS as well as liquid chromatography coupled with ESI‐MS/MS. Pot trial studies conducted by seed bacterization with MBCU2 resulted in statistically significant increase in Arachis hypogaea L. vegetative growth parameters such as root length (91%), shoot length (252%), fresh weight (71%), dry weight (57%), number of pod (128%), and number of seed (290%) in M. phaseolina infested soil over control as well as decreased M. phaseolina disease severity. We suggest that allelochemicals production can be linked to the mechanism of protection of A. hypogaea L. from M. phaseolina by B. sonorensis MBCU2.