bluuebunny/crossref_metadata_2025 huggingface dataset:
Development and Validation of an HPLC Method for Simultaneous Determination of Rifampicin, Isoniazid, Pyrazinamide, and Ethambutol Hydrochloride in Pharmaceutical Formulations
Authors: Chellini Paula R , Lages Eduardo B , Franco Pedro H C , Nogueira Fernando H A , César Isabela C , Pianetti Gerson A
Published: October 2015

Tuberculosis treatment consists of a fixed dose combination of rifampicin (RIF), isoniazid (INH), pyrazinamide (PYZ), and ethambutol hydrochloride (EMB). The combined treatment using various drugs is necessary for patient curing, without recrudescence, and for prevention of drug-resistant mutants, which may occur during treatment. An HPLC-diode array detector (DAD) method for the simultaneous determination of RIF, INH, PYZ, and EMB in fixed dose combination tablets was developed and validated. Chromatographic experiments were performed on an Agilent 1200 HPLC system, and the separation was carried out on a Purospher STAR RP18e (250 × 4.6 mm id, 5 μm, Merck) analytical column. Gradient elution was carried out with a mobile phase of 20 mM monobasic sodium phosphate buffer with 0.2% triethylamine (pH 7.0) and acetonitrile at a flow rate of 1.5 mL/min. The total run time was 12 min, and the re-equilibration time was 5 min. EMB detection was performed at 210 nm, and RIF, INH, and PYZ were detected at 238 nm, using a DAD. The method proved to be specific, linear (r2 > 0.99), precise (RSD <2%), accurate, and robust and may be applied to the QC analysis of pharmaceutical formulations.
Simultaneous Detection of Three Phosphodiesterase Type 5 Inhibitors and Eight of Their Analogs in Lifestyle Products and Screening for Adulterants by High-Performance Thin-Layer Chromatography
Authors: Do Tiên T K , Theocharis Grigorios , Reich Eike
Published: October 2015

An HPTLC method is proposed to permit effective screening for the presence of three phosphodiesterase type 5 inhibitors (PDE5-Is; sildenafil, vardenafil, and tadalafil) and eight of their analogs (hydroxyacetildenafil, homosildenafil, thiohomosildenafil, acetildenafil, acetaminotadalafil, propoxyphenyl hydroxyhomosildenafil, hydroxyhomosildenafil, and hydroxythiohomosildenafil) in finished products, including tablets, capsules, chocolate, instant coffee, syrup, and chewing gum. For all the finished products, the same simple sample preparation may be applied: ultrasound-assisted extraction in 10 mL methanol for 30 min followed by centrifugation. The Rf values of individual HPTLC bands afford preliminary identification of potential PDE5-Is. Scanning densitometry capabilities enable comparison of the unknown UV spectra with those of known standard compounds and allow further structural insight. Mass spectrometric analysis of the material derived from individual zones supplies an additional degree of confidence. Significantly, the proposed screening technique allows focus on the already known PDE5 Is and provides a platform for isolation and chemical categorization of the newly-synthesized analogs. Furthermore, the scope could be expanded to other therapeutic categories (e.g., analgesics, antidiabetics, and anorexiants) that are occasionally coadulterated along with the PDE5-Is. The method was successfully applied to screening of 45 commercial lifestyle products. Of those, 31 products tested positive for at least one illegal component (sildenafil, tadalafil, propoxyphenyl hydroxyhomosildenafil, or dimethylsildenafil).
Development, Optimization, and Validation of a Green and Stability-Indicating HPLC Method for Determination of Daptomycin in Lyophilized Powder
Authors: Tótoli Eliane Gandolpho , Salgado Hérida Regina Nunes
Published: October 2015

Daptomycin is an antimicrobial that plays an important role in clinical practice today because it is considered a promising drug to combat resistant strains, such as methicilin and vancomycin-resistant Gram-positive bacteria. Considering the analysis of daptomycin in a pharmaceutical dosage form, the only method found in literature uses potentially toxic organic solvents. Therefore, the objective of this work was to develop a green and stability-indicating HPLC method for determination of daptomycin in lyophilized powder. The mobile phase was ethanol–water (55 + 45, v/v) at pH 4.5 pumped at a flow rate of 0.6 mL/min. A C18 column was used, and UV detection was performed at 221 nm. Stress degradation studies were conducted in order to demonstrate the specificity and stability-indicating capability of the method. The method was validated according to International Conference on Harmonization guidelines, proving to be linear (r = 0.9996), precise, accurate, robust (demonstrated by the Plackett-Burman model), and specific within the range 20–70 μg/mL. The retention time of daptomycin was 5.8 min. It can be concluded that the validated method can be a fast, safe, and environmentally friendly alternative for the analysis of daptomycin.
A Quercetin Biosensor Based on Chitosan-Entrapped Carbon Nanotube Paste Electrode Coated with DNA
Authors: Rezazadeh Fatemeh , Mohamadi Maryam , Afzali Daryoush , Shamspur Tayebeh , Mostafavi Ali
Published: October 2015

This paper presents an easy, fast, low cost, and sensitive approach for the electrochemical determination of quercetin based on its intercalation into DNA double helix. Electrochemical studies of the interaction between quercetin and DNA showed a decrease in peak currents with a reduction in redox reversibility of quercetin in the presence of the DNA. The electrochemical behavior of quercetin at a chitosan-entrapped carbon nanotube paste electrode coated with DNA was studied. A considerable increase was observed in the oxidation signal of quercetin at the DNA-coated electrode compared with a DNA-free electrode, indicating the preconcentration of quercetin due to its interaction with the surface-confined DNA layer. After optimizing the main experimental parameters influencing the biosensor response, its performance was evaluated from an analytical point of view. Two linear dependences of the anodic peak current of quercetin on its concentration were observed in the ranges of 0.40–7.50 and 7.50–30.0 μmol/L, with LOD and LOQ of 0.039 and 0.13 μmol/L, respectively. The proposed biosensor was successfully applied to the analysis of black and green tea extracts for their quercetin content.
Method Modification of the Thermo Scientific SureTect Listeria monocytogenes Assay for Raw Meat, Dairy, Produce, and Seafood
Authors: Cloke Jonathan , Evans Katharine , Crabtree David , Hughes Annette , Simpson Helen , Leon-Velarde Carlos , Larson Nathan , Dave Keron , Holopainen Jani , Wickstrand Nina , Kauppinen Mikko
Published: October 2015

The Thermo Scientific™ SureTect™ Listeria monocytogenes assay is a real-time PCR assay for the detection of Listeria monocytogenes in food and environmental samples, which was certified during 2013 by the AOAC Research Institute (RI) as Performance Tested MethodSM (PTM) 061302 for a representative range of key food matrixes and production surfaces. This report details the method modification study, which was conducted during 2014, using the AOAC-RI PTM program to extend the validated matrix claims of the assay in comparison to the reference method detailed in International Organization for Standardization 11290-1:1996, including Amendment 1:2004, to gain certification for raw ground turkey, raw ground pork, pasteurized 2% milk, raw pork sausages, raw cod, pasteurized brie cheese, cooked sliced ham, and bagged lettuce. All matrixes were tested by Thermo Fisher Scientific, Microbiology Division, Basingstoke, UK. In addition, brie cheese, bagged lettuce, and raw cod were analyzed independently by the University of Guelph, Canada, during the AOAC-RI controlled independent laboratory study. Using probability of detection (POD) statistical analysis, a significant difference was demonstrated between the candidate and reference methods for the high spiking level with raw ground pork and brie cheese. For all other matrixes and the low spiked levels for raw ground pork and brie cheese, no significant difference by POD was seen between the two methods during the study.
Partially Hydrolyzed Gluten in Fermented Cereal-Based Products by R5 Competitive ELISA: Collaborative Study, First Action 2015.05
Authors: Lacorn Markus , Weiss Thomas
Published: October 2015

In 2008, the AACC International Protein Technical Committee (now Protein and Enzymes Technical Committee) initiated a collaborative study of a method for determining gluten in fermented products, using an R5 competitive ELISA system. The method has been approved as AACCI Approved Method AACCI 38-55.02. The new method has been validated for testing fermented foods and beverages to determine that they conform to the Codex threshold of 20 mg of gluten/kg in total for gluten-free products. It is recommended that the method be accepted by AOAC as Official First Action.
Enhanced Hover Control of Quad Tilt Frame UAV under Windy Conditions
Authors: Krishnakumar R. , Rasheed A. Mohamed , Kumar K. Senthil
Published: October 2015

A key research subject in the area of unmanned aerial vehicles (UAVs) is how to make them autonomous. Towards this goal, the most vital step is stabilizing the attitude of the vehicles. This paper presents the design of an autonomous control system for a hybrid UAV to enable it to carry out a stable hovering mission under external wind disturbances. The hovering capability of the hybrid UAV under windy conditions is analysed with computational fluid dynamics (CFD) and a control law is designed to stabilize the craft in the hovering position. The proposed hovering controller is verified with simulations and experiments. Finally, the flight control system is installed in a small prototype and a full transition flight test, including vertical take-off, transition from vertical flight to cruise, cruise, transition cruise to vertical mode and hover landing, is successfully accomplished.
Coordination of planar cell polarity pathways through Spiny-legs
Authors: Ambegaonkar Abhijit A , Irvine Kenneth D
Published: October 2015

Morphogenesis and physiology of tissues and organs requires planar cell polarity (PCP) systems that orient and coordinate cells and their behaviors, but the relationship between PCP systems has been controversial. We have characterized how the Frizzled and Dachsous-Fat PCP systems are connected through the Spiny-legs isoform of the Prickle-Spiny-legs locus. Two different components of the Dachsous-Fat system, Dachsous and Dachs, can each independently interact with Spiny-legs and direct its localization in vivo. Through characterization of the contributions of Prickle, Spiny-legs, Dachsous, Fat, and Dachs to PCP in the Drosophila wing, eye, and abdomen, we define where Dachs-Spiny-legs and Dachsous-Spiny-legs interactions contribute to PCP, and provide a new understanding of the orientation of polarity and the basis of PCP phenotypes. Our results support the direct linkage of PCP systems through Sple in specific locales, while emphasizing that cells can be subject to and must ultimately resolve distinct, competing PCP signals.
Sterilization of Fusarium oxysporum by treatment of non-thermalequilibrium plasma in nutrient solution
Authors: Yasui Shinji , Seki Satoshi , Yoshida Ryohei , Shoji Kazuhiro , Terazoe Hitoshi
Published: October 2015

Fusarium wilt of spinach due to F. oxysporum infection is one of the most destructive root diseases in hydroponics in factories using the nutrient film technique. We investigated new technologies for the sterilization of microconidia of F. oxysporum by using a non-thermalequilibrium plasma treatment method in nutrient solution. Specifically, we investigated the sterilization capabilities of five types of gas (air, O2, N2, He, and Ar) used for plasma generation. The highest sterilization capability was achieved by using O2 plasma. However, ozone, which causes growth inhibition, was then generated and released into the atmosphere. The sterilization capability was lower when N2 or air plasma was used in the nutrient solution. It was confirmed that sterilization can be achieved by plasma treatment using inert gases that do not generate ozone; therefore, we determined that Ar plasma is the most preferable. In addition, we investigated the sterilization capabilities of other factors associated with Ar plasma generation, without direct plasma treatment. However, none of these other factors, which included Ar bubbling, pH reduction, increased temperature, hydrogen peroxide concentration, and UV radiation, could completely reproduce the results of direct plasma treatment. We assume that radicals such as O or OH may contribute significantly to the sterilization of microconidia of F. oxysporum in a nutrient solution.
Differences in unilateral chest press muscle activation and kinematics on a stable versus unstable surface while holding one versus two dumbbells
Authors: Patterson Jeffrey M. , Vigotsky Andrew D. , Oppenheimer Nicole E. , Feser Erin H.
Published: October 2015

Training the bench press exercise on a traditional flat bench does not induce a level of instability as seen in sport movements and activities of daily living. Twenty participants were recruited to test two forms of instability: using one dumbbell rather than two and lifting on the COR bench compared to a flat bench. Electromyography (EMG) amplitudes of the pectoralis major, middle trapezius, external oblique, and internal oblique were recorded and compared. Differences in range of motion (ROM) were evaluated by measuring an angular representation of the shoulder complex. Four separate conditions of unilateral bench press were tested while lifting on a: flat bench with one dumbbell, flat bench with two dumbbells, COR Bench with one dumbbell, and COR Bench with two dumbbells. The results imply that there are no differences in EMG amplitude or ROM between the COR bench and traditional bench. However, greater ROM was found to be utilized in the single dumbbell condition, both in the COR bench and the flat bench.
Movement of the Intertropical Convergence Zone during the mid‐pleistocene transition and the response of atmospheric and surface ocean circulations in the central equatorial Pacific
Authors: Seo Inah , Lee Yong Il , Kim Wonnyon , Yoo Chan Min , Hyeong Kiseong
Published: October 2015

This paper investigates the causes of a brief, but prominent, cooling episode (1.1–0.8 Ma) that occurred in the equatorial upwelling region of the Atlantic and Pacific during the mid‐Pleistocene transition (MPT) using temporal changes in dust provenance, regional hydrology, and surface productivity recorded in a deep‐sea sediment core from the central equatorial Pacific. The 87Sr/86Sr and ɛNd values of the inorganic silicate fraction indicate deposition of dust from Australia and Central/South America before 0.8 Ma, but a gradual increase in Asian dust deposition after 0.8 Ma. The change in dust provenance was accompanied by an increased dust flux and a decrease in surface productivity and salinity. These changes can be explained by the southward movement of the Intertropical Convergence Zone (ITCZ) and North Equatorial Counter Current (NECC) and the direct influence of these features on the site after 0.8 Ma. Our results, together with previously published Atlantic data, suggest the northward position of the ITCZ between 1.1 and 0.9 Ma, and the southward position thereafter. The meridional movement of the ITCZ is in phase with the cooling and warming trend in upwelling regions in the equatorial Pacific and Atlantic, which suggests strengthening of southeast trades relative to its northern counterpart between 1.1 and 0.9 Ma as a plausible cause of this brief cooling event. The southward movement of the ITCZ from 0.9 to 0.8 Ma indicates more significant cooling in the Northern Hemisphere (NH) than in the Southern Hemisphere, which is supportive of the interpretation that the NH ice sheet expanded significantly and stabilized after 0.9 Ma.
Increased nuisance flooding along the coasts of the United States due to sea level rise: Past and future
Authors: Moftakhari Hamed R. , AghaKouchak Amir , Sanders Brett F. , Feldman David L. , Sweet William , Matthew Richard A. , Luke Adam
Published: October 2015

Mean sea level has risen tenfold in recent decades compared to the most recent millennia, posing a serious threat for population and assets in flood‐prone coastal zones over the next century. An increase in the frequency of nuisance (minor) flooding has also been reported due to the reduced gap between high tidal datums and flood stage, and the rate of sea level rise (SLR) is expected to increase based on current trajectories of anthropogenic activities and greenhouse gases emissions. Nuisance flooding (NF), however nondestructive, causes public inconvenience, business interruption, and substantial economic losses due to impacts such as road closures and degradation of infrastructure. It also portends an increased risk in severe floods. Here we report substantial increases in NF along the coasts of United States due to SLR over the past decades. We then take projected near‐term (2030) and midterm (2050) SLR under two representative concentration pathways (RCPs), 2.6 and 8.5, to estimate the increase in NF. The results suggest that on average, ‐ 80 ± 10% local SLR causes the median of the NF distribution to increase by 55 ± 35% in 2050 under RCP8.5. The projected increase in NF will have significant socio‐economic impacts and pose public health risks in coastal regions.
Does an ionospheric hole appear after an inland earthquake?
Authors: Kamogawa Masashi , Kanaya Tatsuya , Orihara Yoshiaki , Toyoda Atsushi , Suzuki Yuko , Togo Shoho , Liu Jann‐Yenq
Published: October 2015

Ionospheric disturbances occurred as a result of the tsunami associated with the 2011 M9.0 off the Pacific Coast of the Tohoku earthquake (EQ). The ionospheric disturbances propagated radially from the tsunami source area, termed the traveling ionospheric disturbance. In addition to the traveling ionospheric disturbance, an ionospheric plasma depression lasting for approximately 1 h occurred above the tsunami source area, called a tsunami ionospheric hole. In this study, we compare the ionospheric disturbances caused by large inland and submarine EQs to investigate whether an ionospheric plasma depression only occurs in association with a tsunami. Note that we term an EQ with a tsunami a submarine EQ. To investigate the presence of a plasma depression, i.e., an ionospheric hole, associated with an inland EQ, data on total electron content between the global positioning system satellite and its receivers were used. Comparison of two inland and two submarine EQ events with similar magnitudes around 7 showed that ionospheric holes were observed only for the submarine EQs. This discrepancy might be attributed to the different excitation amplitudes of the atmospheric acoustic waves between the unidirectional fault displacement and the tsunami uplift/depression, corresponding to quarter and one‐period variations. From this hypothesis, we predicted that an ionospheric hole could be observed after a significantly large inland EQ with a sufficiently large vertical ground displacement. In fact, we recognized the ionospheric hole generated by the large inland EQ that recently occurred in the Nepal with the magnitude of 7.8 on 25 April 2015.
On the relationship between weakening of the northern polar vortex and the lunar tidal amplification in the equatorial electrojet
Authors: Siddiqui Tarique A. , Stolle Claudia , Lühr Hermann , Matzka Jürgen
Published: October 2015

Enhanced lunar tidal effects in the equatorial electrojet (EEJ) during northern winters in the form of “big L” days have been known for a long time. Recent studies suggest that the changes in the tidal propagation conditions due to stratospheric sudden warmings could be responsible for this phenomenon. In this work we have used the H component of the magnetic field recorded at Huancayo from 1997 to 2013 to study the relation between the timing and magnitude of the semimonthly lunar tide in the EEJ and the stratospheric polar vortex weakening (PVW). We prefer a definition of PVW by taking into account the atmospheric conditions from December to February for each winter. Our results indicate that the semimonthly lunar tide in the EEJ gets enhanced during northern winters when a significant PVW occurs and its peak timing and magnitude is correlated with the timing and intensity of PVW. The timing of lunar tidal peaks and PVW correlate better than their respective magnitudes. Our results suggest that the initiation of the lunar tidal enhancement in most of the cases is closely related to a PVW event. Furthermore, we discuss events where the semimonthly lunar tidal enhancements are not well timed with respect to PVW. We also suggest that the amount of tropospheric forcing into the stratosphere plays a major role in the enhancement of the lunar tides in the EEJ.
Evaluating MJO event initiation and decay in the skeleton model using an RMM‐like index
Authors: Stachnik Justin P. , Waliser Duane E. , Majda Andrew J. , Stechmann Samuel N. , Thual Sulian
Published: October 2015

The Madden‐Julian oscillation (MJO) skeleton model is a low‐order dynamic model that is capable of simulating many of the observed features of the MJO. This study develops a model‐based “MJO” index that is similar to the well‐known real‐time multivariate MJO (RMM) index to better facilitate comparison between the skeleton model and observational data. Multivariate and univariate empirical orthogonal function (EOF) analyses were performed on the convective heating and zonal wind data taken from the skeleton model for simulations forced with an idealized warm pool and observed sea surface temperatures (SSTs). The leading EOF modes indicated a wave number 1 convectively coupled circulation anomaly with zonal asymmetries that closely resembled the observed RMM EOFs, especially when the model was forced with observed SSTs. The RMM‐like index was used to compute an MJO climatology and document the occurrence of primary, continuing, and terminating MJO events in the skeleton model. The overall amount of MJO activity and event lengths compared reasonably well to observations for such a simple model. Attempts at reconciling the observed geographic distribution of individual MJO initiation and termination events were not successful for the stochastic simulations, though stochasticity is necessary in order to produce composite MJOs that initiate and decay with time scales similar to observations. Finally, analysis indicates that the existence of slow‐moving, eastward traveling waves with higher wave numbers (k ≈ 12) embedded within the large‐scale flow often precedes MJO termination in the skeleton model.
Cardiac Abnormalities in Adult Patients With Polymyositis or Dermatomyositis as Assessed by Noninvasive Modalities
Authors: Diederichsen L. P. , Simonsen J. A. , Diederichsen A. C. , Hvidsten S. , Hougaard M. , Junker P. , Søndergaard K. , Lundberg I. E. , Tvede N. , Sandgaard N. C. F. , Christensen A. F. , Dreyer L. , Kay S. , Eskerud K. S. , Petersen H. , Ejstrup L. , Jacobsen S.
Published: October 2015

Objective

Cardiac events are a major cause of death in patients with idiopathic inflammatory myopathies. The study objective was in a controlled setting to describe cardiac abnormalities by noninvasive methods in a cohort of patients with polymyositis (PM) or dermatomyositis (DM) and to identify predictors for cardiac dysfunction.

Methods

In a cross‐sectional study, 76 patients with PM/DM and 48 matched healthy controls (HCs) were assessed by serum levels of cardiac troponin I, electrocardiography, Holter monitoring, echocardiography with tissue Doppler imaging, and quantitative cardiac 99mTc‐pyrophosphate (99mTc‐PYP) scintigraphy.

Results

Compared to HCs, patients with PM/DM more frequently had left ventricular diastolic dysfunction (LVDD) (12% versus 0%; P = 0.02) and longer QRS and QT intervals (P = 0.007 and P < 0.0001, respectively). In multivariate analysis, factors associated with LVDD were age (P = 0.001), disease duration (P = 0.004), presence of myositis‐specific or ‐associated autoantibodies (P = 0.05), and high cardiac 99mTc‐PYP uptake (P = 0.006). In multivariate analysis of the pooled data for patients and HCs, a diagnosis of PM/DM (P < 0.0001) was associated with LVDD.

Conclusion

Patients with PM or DM had an increased prevalence of cardiac abnormalities compared to HCs. LVDD was a common occurrence in PM/DM patients and correlated to disease duration. In addition, the association of LVDD with myositis‐specific or ‐associated autoantibodies and high cardiac 99mTc‐PYP uptake supports the notion of underlying autoimmunity and myocardial inflammation in patients with PM/DM.
Online data‐driven composite adaptive backstepping control with exact differentiators
Authors: Pan Yongping , Liu Yiqi , Yu Haoyong
Published: October 2015

This paper presents an online data‐driven composite adaptive backstepping control for a class of parametric strict‐feedback nonlinear systems with mismatched uncertainties, where both tracking errors and prediction errors are utilized to update parametric estimates. Hybrid exact differentiators are applied to obtain the derivatives of virtual control inputs such that the complexity problem of integrator backstepping can be avoided. Closed‐loop tracking error equations are integrated in a moving‐time window to generate prediction errors such that online recorded data can be utilized to improve parameter adaptation. Semiglobal asymptotic stability of the closed‐loop system is rigorously established by the time‐scales separation and Lyapunov synthesis. The proposed composite adaptation can not only avoid the application of identification models and linear filters resulting in a simpler control structure, but also suppress parametric uncertainties and external perturbations via the time‐interval integral. Simulation results have demonstrated that the proposed approach possesses superior control performances under both noise‐free and noisy‐measurement environments. Copyright © 2015 John Wiley & Sons, Ltd.
Special Rolling Techniques for Improvement of Mechanical Properties of Ultrafine‐Grained Metal Sheets: a Review
Authors: Yu Hai Liang , Lu Cheng , Tieu Anh Kiet , Li Hui Jun , Godbole Ajit , Zhang Shi Hong
Published: October 2015

Interest in ultrafine‐grained (UFG) materials has grown rapidly in past 20 years. This review focuses on the application of special rolling techniques for improvement of the mechanical properties of UFG metal sheets. These techniques include asymmetric rolling, cryorolling, asymmetric cryorolling, cross‐accumulative roll bonding, and skin‐pass rolling. The techniques also include a combination of processes such as equal channel angular press and subsequent rolling, combined high‐pressure torsion and subsequent rolling, as well as combined accumulative roll bonding and subsequent asymmetric rolling. We also discuss the main mechanisms leading to improvement in the ductility of UFG materials related to the special rolling techniques.
Growth and Manipulation of Organic Semiconductors Microcrystals by Wet Lithography
Authors: Gentili Denis , Liscio Fabiola , Mariucci Luigi , Beverina Luca , Melucci Manuela , Toffanin Stefano , Milita Silvia , Cavallini Massimiliano
Published: October 2015

As fabrication and positioning of micro‐ and nanocrystals grow in importance in a wide range technological applications, there is an increasing requirement for the development of a shared technological platform that is able to process materials from solutions on large areas. Here, the application of lithographically controlled wetting (LCW) for the manipulation and positioning of single crystals directly on devices is reported. In the LCW, a stamp, consisting of a metallic grid, is positioned in contact with a liquid thin film spread on a substrate; under these conditions, the capillary forces pin the solution to the stamp protrusions, thus splitting the continuous film in separated droplets or channels. As the solvent evaporates and the solution reaches the saturation, the solute precipitates onto the substrate within the menisci, giving rise to a structured thin film, in correspondence of the protrusion of the stamp. The possibility to achieve a patterning of crystals of conjugated molecules with a defined shape and with controlled size directly on device is demonstrated and pattern of crystals are investigated using polarized optical microscopy, atomic force microscopy, X‐ray diffraction; they are also electrically characterized.
Synthesis of 3‐Arylpyridines via Palladium/Copper‐Catalyzed Annulation of Allylamine/1,3‐Propanediamine and Aldehydes
Authors: Yang Xiaodong , Yang Shenghua , Xiang Likui , Pang Xiaobo , Chen Baohua , Huang Guosheng , Yan Rulong
Published: October 2015

A novel and efficient method for the synthesis of 3‐arylpyridines from allylamine/propanediamine and aldehydes by palladium/copper‐catalyzed oxidative tandem cyclization has been developed. With this reaction, a series of desired 3‐arylpyridines was synthesized in moderate yields via CC/CN bond formation and 6‐endo/exo‐trig cyclization.

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Nachwachsende Rohstoffe: das Problem der Katalysatordesaktivierung und Wege zu seiner Lösung
Authors: Lange Jean‐Paul
Published: October 2015

Das vergangene Jahrzehnt war Zeuge vielzähliger Forschungsarbeiten zur Umwandlung biobasierter Rohstoffe in Kraftstoffe und Chemikalien. Während der Forschungsschwerpunkt auf der Entwicklung neuer aktiver und selektiver Katalysatoren liegt, findet deren langfristige Stabilität weit weniger Aufmerksamkeit. Dieser Aufsatz erörtert die Hauptanforderungen an langfristige Katalysatorstabilität, diskutiert einige Grundlagen und schlägt Wege zum Erreichen dieses Ziels vor. Drei wesentliche Probleme werden besprochen: Katalysatorverschmutzung, Katalysatorvergiftung und Katalysatorzersetzung. Verschmutzung bezieht sich generell auf die Abscheidung unlöslicher Komponenten, die entweder aus den Ausgangsstoffen selbst oder aus der Zersetzung von Ausgangsstoffen/Zwischenprodukten stammen. Vergiftung beschreibt die Abscheidung elektropositiver Kontaminanten (z. B. Alkali‐ und Erdalkalimetalle) an sauren Zentren oder diejenige elektronegativer Kontaminanten (z. B. N und S) an Hydrierungszentren. Katalysatorzersetzung schließlich resultiert aus der thermodynamischen Instabilität der meisten oxidischen Träger, festen Säuren und Basen sowie der Hydrierfunktionen unter hydrothermalen Bedingungen.
A new magnetically recoverable heterogeneous palladium catalyst for phosphonation reactions in aqueous micellar solution
Authors: Sobhani Sara , Zeraatkar Zohre
Published: October 2015

A new heterogeneous palladium complex of 2‐aminothiophenol supported on nanomagnetic γ‐Fe2O3 was synthesized and characterized using various methods. The catalyst was used as a magnetically recoverable heterogeneous palladium catalyst for phosphonation reactions via CP bond formation. Using this method, a wide range of electrophilic benzenes was coupled successfully with phosphite esters (triethyl/tri‐isopropyl/triphenylphosphite and diethyl/di‐isopropyl/diphenylphosphite) in aqueous micellar solution to generate the corresponding arylphosphonates in good to high yields. The catalyst was separated using an external magnet and reused for six consecutive cycles without any significant loss of its reactivity. Copyright © 2015 John Wiley & Sons, Ltd.
Synthesis and characterization of main‐chain, second‐order, nonlinear optical polyurethanes with isolation moieties and zigzag structures
Authors: Li Ying , Yu Ting , Li Zuojia , Wang Zhenguo , Peng Qiang
Published: October 2015

In this study, two main‐chain second‐order nonlinear optical (NLO) polyurethanes were successfully prepared with indole‐based chromophores. The introduced phenyl isolation group and the continuous zigzag polymer backbone were found to be helpful for effectively decreasing the intermolecular dipole–dipole interactions and enhancing the NLO properties of the resulting polymers. The studied polymers exhibited good optical transparency, high thermal stability, and excellent NLO effects; this indicated that the nonlinearity–stability trade‐off and nonlinearity–transparency trade‐off could be alleviated by this newly designed polymer system. Poly{4‐anilinocarbonyl[N‐ethoxyl‐5‐phenyl‐3‐azo(2′‐oxyethylene‐4′‐nitrobenzene)indole]carbonylimino} with a zigzag backbone showed a large second harmonic generation coefficient (d33) value of 88.4 pm/V. However, poly{5‐naphthyliminocarbonyl[N‐ethoxyl‐5‐phenyl‐3‐azo(2′‐oxyethylene‐4′‐nitrobenzene)indole]carbonylimino} (PUAZN) with a continuous zigzag structure exhibited a higher d33 value of 116.2 pm/V, which was attributed to the unique rigid and zigzag linkage of 1,5‐naphthalene as the isolation spacer. The enhanced NLO efficiency and relatively longer term temporal stability made PUAZN as a promising candidate for practical applications in photonic devices. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 42974.
Metabolic engineering of Escherichia coli for the production of isoflavonoid‐4′‐O‐methoxides and their biological activities
Authors: Koirala Niranjan , Pandey Ramesh Prasad , Thuan Nguyen Huy , Ghimire Gopal Prasad , Jung Hye Jin , Oh Tae‐Jin , Sohng Jae Kyung
Published: October 2015

Isoflavonoid representatives such as genistein and daidzein are highly potent anticancer, antibacterial, and antioxidant agents. It have been demonstrated that methylation of flavonoids enhanced the transporting ability, which lead to facilitated absorption and greatly increased bioavailability. In this paper, genetically engineered Escherichia coli was reconstructed by harboring E. coli K12‐derived metK encoding S‐adenosine‐l‐methionine (SAM) synthase (accession number: K02129) for enhancement of SAM as a precursor and Streptomyces avermitilis originated SaOMT2 (O‐methyltransferase, accession number: NP_823558) for methylation of daidzein and genistein as preferred substrates. The formation of desired products via biotransformation including 4′‐O‐methyl‐genistein and 4′‐O‐methyl‐daidzein was confirmed individually by using chromatographical methods such as high‐performance liquid chromatography, liquid chromatography/time‐of‐flight/mass spectrometry (LC‐TOF‐MS), and nuclear magnetic resonance (NMR), and NMR (1H and 13C). Furthermore, substrates concentration, incubation time, and media parameters were optimized using flask culture. Finally, the most fit conditions were applied for fed‐batch fermentation with scale‐up to 3 L (working volume) to obtain the maximum yield of the products including 164.25 µM (46.81 mg/L) and 382.50 µM (102.88 mg/L) for 4′‐O‐methyl genistein and 4′‐O‐methyl daidzein, respectively. In particular, potent inhibitory activities of those isoflavonoid methoxides against the growth of cancer line (B16F10, AGS, and HepG2) and human umbilical vein endothelial cells were investigated and demonstrated. Taken together, this research work described the production of isoflavonoid‐4′‐O‐methoxides by E. coli engineering, improvement of production, characterization of produced compounds, and preliminary in vitro biological activities of the flavonoids being manufactured.
A selective chromofluorogenic chemodosimeter for fluoride ions based on distyrylbenzenes derivatives containing dual Si–O groups
Authors: Ji Kai , Wu Haocheng , Chen Jinju , Shen Jiajie , Wang Xinyu , Wu Hongwei , Liu Chuanxiang
Published: October 2015

A new chemodosimeter for fluoride ions based on F− triggered dual Si–O bond cleavage of distyrylbenzenes derivatives was developed for the first time. Upon the addition of F− ions, the chemodosimeter (7) displayed apparent color changes from colorless to faint yellow, with a dramatic red‐shift in the emission wavelength (~100 nm), and higher selectivity for fluoride over other common anions. With the aid of fluorescence measurements, the limit of detection could be as low as 89.8 nm. Using a ‘dipstick’ approach, chemodosimeter (7) might serve as a prototype device for fluorescent detecting F− without the need for any additional equipment. Copyright © 2015 John Wiley & Sons, Ltd.
Cell differentiation on disk‐ and string‐shaped hydrogels fabricated from Ca2+‐responsive self‐assembling peptides
Authors: Fukunaga Kazuto , Tsutsumi Hiroshi , Mihara Hisakazu
Published: October 2015

We recently developed a self‐assembling peptide, E1Y9, that self‐assembles into nanofibers and forms a hydrogel in the presence of Ca2+. E1Y9 derivatives conjugated with functional peptide sequences derived from extracellular matrices (ECMs) reportedly self‐assemble into peptide nanofibers that enhance cell adhesion and differentiation. In this study, E1Y9/E1Y9‐IKVAV‐mixed hydrogels were constructed to serve as artificial ECMs that promote cell differentiation. E1Y9 and E1Y9‐IKVAV co‐assembled into networked nanofibers, and hydrogels with disk and string shapes were formed in response to Ca2+ treatment. The neuronal differentiation of PC12 cells was facilitated on hydrogels of both shapes that contained the IKVAV motifs. Moreover, long neurites extended along the long axis of the string‐shaped gel, suggesting that the structure of hydrogels of this shape can affect cellular orientation. Thus, E1Y9 hydrogels can potentially be used as artificial ECMs with desirable bioactivities and shapes that could be useful in tissue engineering applications. © 2015 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 106: 476–483, 2016.
Inquiry‐based experiments for large‐scale introduction to PCR and restriction enzyme digests
Authors: Johanson Kelly E. , Watt Terry J.
Published: October 2015

Polymerase chain reaction and restriction endonuclease digest are important techniques that should be included in all Biochemistry and Molecular Biology laboratory curriculums. These techniques are frequently taught at an advanced level, requiring many hours of student and faculty time. Here we present two inquiry‐based experiments that are designed for introductory laboratory courses and combine both techniques. In both approaches, students must determine the identity of an unknown DNA sequence, either a gene sequence or a primer sequence, based on a combination of PCR product size and restriction digest pattern. The experimental design is flexible, and can be adapted based on available instructor preparation time and resources, and both approaches can accommodate large numbers of students. We implemented these experiments in our courses with a combined total of 584 students and have an 85% success rate. Overall, students demonstrated an increase in their understanding of the experimental topics, ability to interpret the resulting data, and proficiency in general laboratory skills. © 2015 by The International Union of Biochemistry and Molecular Biology, 43:441–448, 2015.
Induction of neural differentiation in rat C6 glioma cells with taxol
Authors: Chao Chuan‐Chuan , Kan Daphne , Lo Ta‐Hsuan , Lu Kuo‐Shyan , Chien Chung‐Liang
Published: October 2015

Background

Glioblastoma is a common and aggressive type of primary brain tumor. Several anticancer drugs affect GBM (glioblastoma multiforme) cells on cell growth and morphology. Taxol is one of the widely used antineoplastic drugs against many types of solid tumors, such as breast, ovarian, and prostate cancers. However, the effect of taxol on GBM cells remains unclear and requires further investigation.

Methods

Survival rate of C6 glioma cells under different taxol concentrations was quantified. To clarify the differentiation patterns of rat C6 glioma cells under taxol challenge, survived glioma cells were characterized by immunocytochemical, molecular biological, and cell biological approaches.

Results

After taxol treatment, not only cell death but also morphological changes, including cell elongation, cellular processes thinning, irregular shapes, and fragmented nucleation or micronuclei, occurred in the survived C6 cells. Neural differentiation markers NFL (for neurons), βIII‐tubulin (for neurons), GFAP (for astrocytes), and CNPase (for oligodendrocytes) were detected in the taxol‐treated C6 cells. Quantitative analysis suggested a significant increase in the percentage of neural differentiated cells. The results exhibited that taxol may trigger neural differentiation in C6 glioma cells. Increased expression of neural differentiation markers in C6 cells after taxol treatment suggest that some anticancer drugs could be applied to elimination of the malignant cancer cells as well as changing proliferation and differentiation status of tumor cells.
Consumers' attributions and brand evaluations in product‐harm crises: The role of implicit theories of personality
Authors: Yin Cheng‐Yue , Yu Hong‐Yan , Poon Patrick
Published: October 2015

This study aims to examine the moderating role of implicit theories of personality in the relationship between corporate recovery strategy (i.e., support versus stonewalling) and consumers' attributions (and brand evaluations). It is suggested that consumers' implicit theories about the fixedness/malleability of personality can affect consumers' attributions and brand evaluations during a product‐harm crisis. In addition, corporate image (i.e., strong versus weak) can moderate the influence of the role of implicit theories of personality. Two experiments were conducted to examine the proposed hypotheses. Results of Experiment 1 show that consumers who endorse entity theory (i.e., entity theorists) are likely to attribute crisis as more internal, stable, and controllable, particularly when they do not have any prior knowledge about the firm. The entity theorists would have more negative brand evaluations than incremental theorists (who endorse incremental theory), when “support” strategy was used by the firm. Results of Experiment 2 show that entity theorists are prone to have more external (internal) and unstable (stable) attributions toward a firm with a strong (weak) corporate image. Furthermore, entity theorists would provide more positive brand evaluations than incremental theorists when “stonewalling” strategy was used by a firm with strong corporate image, but not when “support” strategy was used by a firm with weak corporate image. Managerial implications are provided to managers with regard to product‐harm crisis and recovery strategies. Copyright © 2015 John Wiley & Sons, Ltd.
Aortic root volume is associated with contained rupture of the aortic annulus in balloon‐expandable transcatheter aortic valve replacement
Authors: Reinöhl Jochen , Psyrakis Dimitrios , Kaier Klaus , Kodirov Sodikdjon , Siepe Matthias , Gutmann Anja , von zur Mühlen Constantin , Moser Martin , Ahrens Ingo , Pache Gregor , Zirlik Andreas , Langer Mathias , Beyersdorf Friedhelm , Zehender Manfred , Bode Christoph , Blanke Philipp
Published: October 2015

Background

Aortic annulus rupture is a rare, but potentially fatal complication of transcatheter aortic valve replacement (TAVR), especially when it occurs by balloon‐expandable devices. In order to improve the predictability of procedures and avoid ruptures we investigated whether or not the aortic root volume measures is a useful indicator of risk, and if it could be useful for the prosthesis size selection.

Methods and Results

From a retrospective series of 172 TAVR patients, seven experienced contained aortic annulus ruptures. The receiver operating curves were used to illustrate sensitivity and specificity of the different aortic annulus size and aortic root volume measures. The annulus area oversizing of ≥20% resulted in a sensitivity of 100%, specificity of 55.76%, and positive predictive value (PPV) of 8.75%. In patients receiving 26mm prostheses, the aortic root volume (ARV <13600mm3) provided a better specificity and PPV (79.63 and 18.52%, respectively). A two‐step testing procedure considering the area derived average annulus diameter (Darea <23mm) as a first separating parameter and then the ARV (<13,600mm3) as a further indicator showed the most promising results with the PPV of 31.25%. Regardless of the procedure steps no false negative results were predicted.

Conclusions

Our data show that the ARV provides a better predictive value for correct prosthesis sizing than established annulus measurements, especially in ‘borderline’ annuli. We suggest a two‐step testing procedure for prostheses size selection, considering Darea and ARV to minimize the risk of annulus rupture. Prospective studies and examination of larger datasets are warranted to confirm these findings. © 2015 Wiley Periodicals, Inc.
Controlled Nanopores in Thin Films of Nonstoichiometrically Supramolecularly Assembled Graft Copolymers
Authors: Cho Suk Man , Song Giyoung , Hwang Sun Kak , Kim Richard Hahnkee , Lee Jinseong , Yu Seunggun , Huh June , Park Hui Joon , Park Cheolmin
Published: October 2015

Herein, nanometer‐scale morphologies of graft‐copolymer‐like supramolecular thin films, composed of sulfonic acid terminated polystyrene (SPS) and poly(2‐vinylpyridine) (P2VP), and their application to antireflection coatings were investigated. The intermolecular complexes of SPS and P2VP, formed through nonstoichiometric multiple hydrogen bonding between the sulfonic acid group of SPS and the nitrogen atom in pyridine unit of P2VP, occurring in film deposition allowed for the formation of spherical micelles (with SPS and P2VP as the corona and core, respectively) in the thin film. Interestingly, the domain size of the micelles was tunable from approximately 20 to 90 nm on average by controlling either the blend ratio of components or the concentration of polymer solution. Furthermore, nanoporous thin films could be easily prepared by removing the core of micelle‐based nanostructures by using a simple solvent etching process, leaving sulfonic acid groups on the surface of nanopores, which can be utilized as potential functional sites. Those resultant nanoporous thin films were conveniently employed as an antireflection layer on a glass substrate, giving a maximum 97.8 % transmittance in the visible wavelength range.
Controlled Redox Chemistry at Cerium within a Tripodal Nitroxide Ligand Framework
Authors: Bogart Justin A. , Lippincott Connor A. , Carroll Patrick J. , Booth Corwin H. , Schelter Eric J.
Published: October 2015

Ligand reorganization has been shown to have a profound effect on the outcome of cerium redox chemistry. Through the use of a tethered, tripodal, trianionic nitroxide ligand, [((2‐tBuNOH)C6H4CH2)3N]3− (TriNOx3−), controlled redox chemistry at cerium was accomplished, and typically reactive complexes of tetravalent cerium were isolated. These included rare cationic complexes [Ce(TriNOx)thf][BArF4], in which ArF=3,5‐(CF3)2‐C6H3, and [Ce(TriNOx)py][OTf]. A rare complete Ce–halide series, Ce(TriNOx)X, in which X=F−, Cl−, Br−, I−, was also synthesized. The solution chemistry of these complexes was explored through detailed solution‐phase electrochemistry and 1H NMR experiments and showed a unique shift in the ratio of species with inner‐ and outer‐sphere anions with size of the anionic X− group. DFT calculations on the series of calculations corroborated the experimental findings.
Efficient Domino Hydroformylation/Benzoin Condensation: Highly Selective Synthesis of α‐Hydroxy Ketones
Authors: Dong Kaiwu , Sang Rui , Soule Jean‐Francois , Bruneau Christian , Franke Robert , Jackstell Ralf , Beller Matthias
Published: October 2015

An improved domino hydroformylation/benzoin condensation to give α‐hydroxy ketones has been developed. Easily available olefins are smoothly converted into the corresponding α‐hydroxy ketones in high yields with excellent regioselectivities. Key to success is the use of a specific catalytic system consisting of a rhodium/phosphine complex and the CO2 adduct of an N‐heterocyclic carbene.
Enantioselective NHC‐Catalyzed Redox [2+2] Cycloadditions with Perfluoroketones: A Route to Fluorinated Oxetanes
Authors: Davies Alyn T. , Slawin Alexandra M. Z. , Smith Andrew D.
Published: October 2015

The N‐heterocyclic carbene (NHC) catalyzed redox formal [2+2] cycloaddition between α‐aroyloxyaldehydes and perfluoroketones, followed by ring‐opening in situ delivers a variety of perfluorinated β‐hydroxycarbonyl compounds in good yield, and excellent diastereo‐ and enantioselectivity. Through a reductive work‐up and subsequent cyclization, this protocol offers access to highly substituted fluorinated oxetanes in two steps and in high ee.
ChemInform Abstract: Graphene‐Based Photocatalysts for Solar‐Fuel Generation
Authors: Xiang Quanjun , Cheng Bei , Yu Jiaguo
Published: October 2015

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