bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Tanshinones in Danshen (Salvia miltiorrhiza) by High‐Performance Liquid Chromatography with Fluorescence Detection after pre‐Column Derivatisation
Authors: Kishikawa Naoya , Yamanouchi Akiko , El‐Maghrabey Mahmoud Hamed , Ohyama Kaname , Kuroda Naotaka
Published: September 2017

Introduction

Tanshinones are a major class of bioactive ingredients in the traditional herbal medicines, Danshen (Salvia miltiorrhiza). A sensitive and reliable determination method for tanshinones is useful to ensure the quality of Danshen.

Objective

To develop a sensitive and selective analytical method for tanshinones by high‐performance liquid chromatography (HPLC) with fluorescence detection after pre‐column derivatisation.

Methodology

The proposed method depends on derivatisation reaction of tanshinones with 4‐carbomethoxybenzaldehyde and ammonium acetate forming intensely fluorescent imidazole derivative.

Results

The proposed method provided excellent sensitivity with the detection limits of 3.3 nM (66 fmol/injection), 3.2 nM (64 fmol/injection) and 2.0 nM (40 fmol/injection) for cryptotanshinone, tanshinone I and tanshinone IIA, respectively, without the necessity of complicated instrumentations. The developed method is successfully applied to quantify the contents of tanshinones in Danshen.

Conclusion

The developed method is the first analytical method for tanshinones by fluorescence detection. Since the derivatisation reaction is selective for the o‐quinone structure of tanshinone, the developed method will become a suitable mean for the discovering of tanshinone type diterpenoids from herbal samples. Copyright © 2017 John Wiley & Sons, Ltd.
Infrared‐Assisted Extraction and HPLC‐Analysis of Prunus armeniaca L. Pomace and Detoxified‐Kernel and their Antidiabetic Effects
Authors: Raafat Karim , El‐Darra Nada , Saleh Fatima A. , Rajha Hiba N. , Maroun Richard G. , Louka Nicolas
Published: September 2017

Introduction

Prunus armeniaca L. (P. armeniaca) is one of the medicinal plants with a high safety‐profile.

Objectives

The aim of this work was to make an infrared‐assisted extraction (IR‐AE) of P. armeniaca fruit (pomace) and kernel, and analyse them using reverse phase high‐performance liquid chromatography (RP‐HPLC) aided method.

Methods

IR‐AE is a novel‐technique aimed at increasing the extraction‐efficiency. The antidiabetic‐potentials of the P. armeniaca pomace (AP) and the detoxified P. armeniaca kernel extract (DKAP) were monitored exploring their possible hypoglycemic‐mechanisms. Acute (6 h), subchronic (8 days) and long‐term (8 weeks) assessment of Diabetes mellitus (DM) using glucometers and glycated hemoglobin (HbA1c) methods were applied.

Results

Serum‐insulin levels, the inhibitory effects on alpha‐glucosidase, serum‐catalase (CAT) and lipid peroxidation (LPO) levels were also monitored. AP was shown to be rich in polyphenolics like trans‐lutein (14.1%), trans‐zeaxanthin (10.5%), trans‐ß‐cryptoxanthin (11.6%), 13, cis‐ß‐carotene (6.5%), trans 9, cis‐ß‐carotene (18.4%), and ß‐carotene (21.5%). Prunus armeniaca kernel extract before detoxification (KAP) was found to be rich in amygdaline (16.1%), which caused a high mortality rate (50.1%), while after detoxification (amygdaline, 1.4%) a lower mortality rate (9.1%) was found. AP showed significant (p ≤ 0.05, n = 7/group) antidiabetic‐activity more prominent than DKAP acutely, subchronically and on longer‐terms. IR‐AEs displayed more efficient acute and subchronic blood glucose level (BGL) reduction than a conventional extraction method, which might be attributed to IR‐AE superiority in extraction of active ingredients. AP showed more‐significant and dose‐dependent increase in serum‐insulin, CAT‐levels and body‐weights more prominent than those of DKAP. Alpha‐glucosidase and LPO levels were inhibited with AP‐groups more‐significantly.

Conclusion

In comparison to conventional‐methods, IR‐AE appeared to be an efficient and time‐conserving novel extraction method. The antidiabetic‐potentials of pomace and detoxified‐kernels of P. armeniaca were probably mediated via the attenuation of glucose‐provoked oxidative‐stress, the inhibition of alpha‐glucosidase and the marked insulin‐secretagogue effect. Copyright © 2017 John Wiley & Sons, Ltd.
Minimising bulk lifetime degradation during the processing of interdigitated back contact silicon solar cells
Authors: Rahman Tasmiat , To Alexander , Pollard Michael E. , Grant Nicholas E. , Colwell Jack , Payne David N.R. , Murphy John D. , Bagnall Darren M. , Hoex Bram , Boden Stuart A.
Published: September 2017

In this work, we develop a fabrication process for an interdigitated back contact solar cell using BBr3 diffusion to form the p+ region and POCl3 diffusion to form the n+ regions. We use the industry standard technology computer‐aided design modelling package, Synopsys Sentaurus, to optimize the geometry of the device using doping profiles derived from electrochemical capacitance voltage measurements. Cells are fabricated using n‐type float‐zone silicon substrates with an emitter fraction of 60%, with localized back surface field and contact holes. Key factors affecting cell performance are identified including the impact of e‐beam evaporation, dry etch damage, and bulk defects in the float zone silicon substrate. It is shown that a preoxidation treatment of the wafer can lead to a 2 ms improvement in bulk minority carrier lifetime at the cell level, resulting in a 4% absolute efficiency boost.
IR‐ and NEXAFS‐spectroscopic characterization of plasma‐nitrogenated polyolefin surfaces
Authors: Khosravi Zohreh , Kotula Stefan , Lippitz Andreas , Unger Wolfgang E. S. , Klages Claus‐Peter
Published: September 2017

Modification of polyethylene and polypropylene surfaces by atmospheric‐pressure plasmas using mixtures of nitrogen and hydrogen was studied using Fourier‐transform infrared spectroscopy in the attenuated total reflection mode (FTIR‐ATR) and by near‐edge x‐ray absorption fine structure spectroscopy (NEXAFS) in order to shed some light on the chemical nature of nitrogen‐containing functional groups on the polymer surface. Using FTIR‐ATR spectroscopy combined with hydrogen‐deuterium isotope exchange of active hydrogen atoms, it was shown that the direct treatment of PE foils by dielectric barrier discharges (DBDs) in N2/H2 mixtures and a subsequent exposure of the samples to the ambient air results in the formation of –NH2 moieties of primary amides on the polymer surface. Corresponding in situ experiments with streaming N2/H2 DBD post‐discharges virtually free of H2O and O2, on the other hand, showing the absence of –NH2, proving that no primary amines or amides are formed by this treatment although substantial amounts of nitrogen are incorporated. Moreover, directly N2/H2‐plasma‐treated polymer surfaces, similar to afterglow‐treated low‐density polyethylene (LDPE), show amphiphilic character as to be seen by chemical derivatization with nucleophilic reagents 4‐(trifluoromethyl)phenylhydrazine and 4‐(trifluoromethyl)benzyl­amine, in addition to electrophilic aromatic aldehydes normally used to derivatize such surfaces. The presence of imines or other functional groups with CN moieties which may be invoked to explain the dual (amphiphilic) reactivity is proven by NEXAFS studies on ultrathin plasma‐treated PE films, confirming significant amounts of nitrogen in CN bonds and carbon in CC bonds.
Insecticide susceptibilities of the two rice planthoppers Nilaparvata lugens and Sogatella furcifera in East Asia, the Red River Delta, and the Mekong Delta
Authors: Matsumura Masaya , Sanada‐Morimura Sachiyo , Otuka Akira , Sonoda Shoji , Van Thanh Dinh , Van Chien Ho , Van Tuong Phan , Loc Phung Minh , Liu Ze‐Wen , Zhu Zeng‐Rong , Li Jian‐Hong , Wu Gang , Huang Shou‐Horng
Published: September 2017

BACKGROUND

The two rice planthoppers, Nilaparvata lugens and Sogatella furcifera, have different life cycles in the regions of East Asia, the Red River Delta, and the Mekong Delta. The susceptibilities of these species to a range of insecticides have not previously been compared among the three regions over multiple years. Here, we describe the differences and similarities in insecticide susceptibilities of the two species among the three regions in 2006–2011.

RESULTS

In all three regions in 2006 − 2011, N. lugens developed high and moderate levels of resistance to imidacloprid and thiamethoxam, respectively, but this species did not develop resistance to fipronil. In contrast, S. furcifera developed a high level of resistance to fipronil. The ranges in 50% lethal dose (LD50) values for N. lugens treated with both imidacloprid and thiamethoxam were similar over time between East Asia and the Red River Delta, and were different in the Mekong Delta.

CONCLUSION

The results support the idea that resistant populations migrate from the Red River Delta region to East Asia. Therefore, continuous monitoring of the susceptibility of N. lugens to insecticides in the Red River Delta is very important for insecticide resistance management in East Asia. © 2017 Society of Chemical Industry
On the Structural and Mechanical Properties of Poly(Phenylacetylene) Truss‐Like Hexagonal Hierarchical Nanonetworks
Authors: Grima‐Cornish James N. , Grima Joseph N. , Evans Kenneth E.
Published: September 2017

A novel class of hexagonal nanoscale honeycombs made from penta and tetra substituted polyphenlyacetylenes is proposed and modeled as crystalline systems using force‐field based simulations. It is shown that, in‐plane, these systems behave rather similarly to crystalline forms of graphyne, graphdiyne, and other fully substituted equivalents but benefit from the presence of larger pores which makes them less stiff and may enable them to be used in a wider range of applications such as nanofiltration. It is also shown that at large strains these systems have the potential to exhibit auxetic out‐of‐plane behaviour, a property which can be manifested in other triangulated systems and can be explained from buckling of some nanoribs in the systems.
Influence of the Growth Temperature on the Defective Structure of the Multi‐Walled Carbon Nanotubes
Authors: Krasnikov Dmitry V. , Bokova‐Sirosh Sofya N. , Tsendsuren Tsog‐Ochir , Romanenko Anatoly I. , Obraztsova Elena D. , Volodin Vladimir A. , Kuznetsov Vladimir L.
Published: September 2017

The present paper is devoted to the influence of the growth temperature of multi‐walled carbon nanotubes (MWCNTs) on their defective structure. The MWCNTs obtained within the range of 610–750 °C have been studied using two methods: Raman spectroscopy and the analysis of the temperature dependence of conductivity. This approach allows us to obtain independent data on the concentration of the defects within the MWCNTs via the intensity ratio of 2D and D bands, on one hand, and charge carrier concentration, on the other hand. The results obtained using Raman spectroscopy and the analysis of the conductivity have provided asymptotic and volcano‐like curves, respectively, of defect concentration within the temperature range studied. This can be attributed to the difference in the probing depth of each method (∼50 nm for Raman spectroscopy, and ∼2–3 nm for conductivity measurements) providing different sensitivity to surface impurities or defects. The secondary factors (the size of the active component, the amount of the lateral carbon deposits) have been shown to mask the influence of the growth temperature. Nevertheless, as these secondary factors and the synthesis temperature independently affect the effective nanotube defectiveness, we have shown the defect concentration to fall with increasing MWCNT growth temperature.
Robust stability analysis of uncertain multiorder fractional systems: Young and Jensen inequalities approach
Authors: Taghavian Hamed , Tavazoei Mohammad Saleh
Published: September 2017

Robust stability analysis of multiorder fractional linear time‐invariant systems is studied in this paper. In the present study, first, conservative stability boundaries with respect to the eigenvalues of a dynamic matrix for this kind of systems are found by using Young and Jensen inequalities. Then, considering uncertainty on the dynamic matrix, fractional orders, and fractional derivative coefficients, some sufficient conditions are derived for the stability analysis of uncertain multiorder fractional systems. Numerical examples are presented to confirm the obtained analytical results.
Cyanosilylation of Aldehydes Catalyzed by MIL‐101(Cr): A Theoretical Investigation
Authors: de Oliveira Aline , Mavrandonakis Andreas , de Lima Guilherme F. , De Abreu Heitor A.
Published: September 2017

The Metal‐Organic Frameworks (MOFs) compose a class of solids with promising applicability. There are many different structures and many distinct ways to synthesize new solids based on previously known MOFs. The understanding of these materials at molecular level is very important, because it can assist the design of solids with optimized properties to a desired application. The cyanosilylation of aldehydes is a reaction which can be used to evaluate the catalytic performance of a material as Lewis acid or base. However, it is experimentally difficult to identify the most relevant sites. In this work, DFT calculations were used aiming to get information about the important chemical structural characteristics of the MOF MIL‐101(Cr) which explain its catalytic activity to the cyanosilylation reaction. The investigation shows that when this MOF acts as a Lewis acidic catalyst the cyanosilylation is 1010 times faster than the non‐catalyzed process.
Carbon Nanotube/Graphite Mixtures Used as Cavity Cell Macroelectrodes and their Unexpected Behavior Towards Benzyl Bromide Electroreduction
Authors: Santos de Oliveira Luciana , Navarro Marcelo , Tavares Ribeiro Rogério , Lago Falcão Eduardo Henrique
Published: September 2017

Powder macroelectrodes were prepared by mixing carbon nanotubes (CNT) and graphite in different ratios, and evaluated as electron transfer medium for the benzyl bromide electroreduction. 1,2‐Diphenylethane (DPE) (1‐electron process) was favored, instead of toluene (2‐electron process), for all CNT:graphite mass ratios, while pure graphite or CNT favored toluene as major product. The 3:7 CNT:graphite mass ratio gave the best result, furnishing 70 % yield of DPE. Cyclic voltammetry showed a cathodic shift for the benzyl bromide reduction potential by using CNT:graphite electrode composition, favoring the 1‐electron process products during the electrolyses, and corroborating the results observed.
Microwave‐Assisted Synthesis of C‐4′‐(1,5‐disubstituted)‐triazole‐spiro‐α‐L‐arabinofuranosyl Nucleosides
Authors: Rungta Pallavi , Mangla Priyanka , Maikhuri Vipin K. , Singh Sunil K. , Prasad Ashok K.
Published: September 2017

The synthesis of C‐4′‐(1,5‐disubstituted)‐triazole‐spiro‐α‐L‐arabinofuranosyl nucleosides has been achieved in a regio‐ and stereospecific manner by using intramolecular Huisgen 1,3‐dipolar cycloaddition reaction. The synthesis of these nucleosides necessitates the possession of azide and alkyne moieties in the same molecule, which is being employed as the precursor. Thus, the crucial step in the synthesis of targeted compound is the preparation of 1,2,3‐tri‐O‐acetyl‐5‐azido‐5‐deoxy‐4‐C‐propynyl‐α,β‐L‐arabinofuranose and its conversion to corresponding nucleosides via nucleobase coupling. The microwave heating of such tailor made nucleoside precursors furnishes the targeted spironucleosides, which combines conformational‐restriction concept with a triazole structural feature highly sought in drug design.
Magnetic Properties of Bilayer Thin Film Composed of Hard and Soft Ferromagnetic Prussian Blue Analogues
Authors: Fitta Magdalena , Czaja Paweł , Krupiński Michał , Lewińska Gabriela , Szuwarzyński Michał , Bałanda Maria
Published: September 2017

The molecule‐ based bilayer system composed of hard Ni3.38[Fe(CN)6]2⋅nH2O and soft Ni3.1[Cr(CN)6]2⋅nH2O ferromagnetic Prussian blue analogues has been fabricated on a solid substrate by “layer by layer” deposition. The structure and morphology characterization as well as results of magnetic measurements are described. The thickness of the bilayer is ca. 140 nm including a 35 nm interface. This bilayer system shows anisotropic magnetic properties reflected in the shape of magnetic hysteresis measured in various film orientation with respect to the direction of external magnetic field. There is no exchange interaction between hard and soft magnetic layer and irrespective of bilayer orientation, the magnetization and demagnetization process of both Ni3.38[Fe(CN)6]2⋅nH2O and Ni3.1[Cr(CN)6]2⋅nH2O layers occurs independently.
Development of a Dual‐Fluorescence Emission Sensor Based on Photo‐Induced Electron Transfer and Aggregation‐Induced Emission Enhancement for Detection of Water
Authors: Ooyama Yousuke , Nomura Ryosuke , Enoki Toshiaki , Sagisaka Rizumu , Tsunoji Nao , Ohshita Joji
Published: September 2017

We have designed and developed a tetraphenylethen (TPE)‐anthracene‐(aminomethyl)phenylboronic acid ester (AminoMePhenylBPin) structure RN‐1 possessing PET (photo‐induced electron transfer) and AIEE (aggregation‐induced emission enhancement) characteristics as a fluorescent sensor for detection of water in organic solvents. It was found that the appearance of fluorescence band in the low water content region is attributed to the fluorescence emission originating from the anthracene skeleton due to the formation of PET inactive species RN‐1(H2O) by the addition of water molecules. Moreover, the appearance of broad fluorescence band in the high water content region is attributed to the AIEE characteristic due to restricted intramolecular rotation (RIR) of TPE unit associated with the aggregate formation (RN‐1(H2O)‐A). This work proposes that the PET/AIEE hybrid fluorescence sensor can act as a dual‐fluorescence emission sensor for detection of water in low water content region and high water content region in solvents.
Synthesis, Crystal Structure and Magnetic Properties of [Mn((1R, 2R)‐Salcy)N3/NCS] Complexes: Solvent Dependent Crystallization of Monomers, Chains and Dimers.
Authors: Bhargavi Govindugari , Rajasekharan Melath V. , Costes Jean‐Pierre
Published: September 2017

Five new chiral MnIII complexes [Mn((1R, 2R)‐Salcy)N3]∞⋅CH3CN (1), [Mn((R,R)‐Salcy)N3]∞ (2), [Mn((R,R)‐Salcy)N3] (4), [Mn((R,R)‐Salcy)(H2O)N3]⋅C4H8O (5) and [Mn((R,R)‐Salcy)NCS] (6) have been synthesized and characterized by X‐ray structural analysis and magnetic measurements (Salcy=N,N′‐bis(salicylidene)‐1,2‐diaminocyclohexane}. The four azido complexes have been obtained from the previously known [Mn((R,R)‐Salcy)(CH3OH)N3] (3) by crystallization from various solvents. Compounds 1 and 2 are trans‐μ‐1,3‐azide bridged coordination polymers. While 1 forms helical chains, the chain in 2 is formed via translation of a dimeric helicate repeat unit. Compound 3 is a methanol coordinated mononuclear azido complex which forms a 2D‐network through H‐bonding. Compounds 4 and 6 are phenoxo‐bridged dimers without inversion center. Compound 5 is an aqua coordinated mononuclear azido complex, which forms a 1D‐chain through O−H⋅⋅⋅N hydrogen bonding involving axial ligands. In all six compounds MnIII exhibits a characteristic Jahn−Teller elongation. The magnetic coupling in 1 and 2 leads to antiferromagnetic interaction along the chain (2 J=−11.6 cm−1 for 1 and –11.9 cm−1 for 2) through the μ‐1,3‐azide bridge. Compound 3 is weakly antiferromagnetic due to hydrogen bonding interactions in the lattice. The phenoxo dimers (4 and 6) do not have measurable exchange interaction, the low temperature susceptibility being influenced mainly by zero‐field splitting.
Solvent‐Sensitive Sign Inversion of Excimer Origin Circularly Polarized Luminescence in Bipyrenyl Peptides
Authors: Mimura Yuki , Kitamura Sayaka , Shizuma Motohiro , Kitamatsu Mizuki , Fujiki Michiya , Imai Yoshitane
Published: September 2017

The photoexcited and ground state chiralities of enantiopure oligopeptides bearing two pyrenyl groups (DD‐2/LL‐2: four methylene spacer between two pyrenyl groups and DD‐1/LL‐1: no methylene spacer thereof) in eight common organic solvents (CHCl3, CH2Cl2, MeOH, CH3CN, DMF, NMP, DMAc, and acetone) were investigated by means of circularly polarized luminescence (CPL) and circular dichroism (CD) spectroscopies. It was found that chiroptical signs of pyrene‐origin CPL and CD signals largely depend on the nature of solvents and are susceptible to the methylene spacer. Actually, the excimer‐origin CPL signs at 450–510 nm of DD‐1/LL‐1 in DMF were (–)/(+), respectively, while those in other solvents were oppositely (+)/(–), respectively. On the other hand, in DD‐2/LL‐2, the excimer‐origin CPL signs were (–)/(+) in CH2Cl2 (and CHCl3), respectively, and (+)/(–) in MeOH/DMF/NMP/DMAc, respectively. The solvent dependent and the methylene spacer dependent CD sign inversion of DD‐1/LL‐1 and DD‐2/LL‐2 were also found. These results led to conclude that the solvent molecule and the methylene spacer collaboratively affect both the ground state chirality and the photoexcited chirality.
Effects of Additives on the Preparation of Ag Nanoparticles Using the Microwave‐Induced Plasma in Liquid Process
Authors: Nishimoto Masamu , Tsukamoto Hiroki , Nguyen Mai Thanh , Yonezawa Tetsu
Published: September 2017

The effect of additives, i. e., H2O2 and pH adjustors, on the preparation of Ag nanoparticles (NPs) fabricated using the microwave‐induced plasma in liquid process (MWPLP) has been investigated. When both aqueous ammonia and NaOH were used as pH adjustors, the rate of the reduction of silver ions decreased with lower concentrations of H2O2 or at higher pH values. Under these conditions, the aggregation of generated nuclei during the early stages of the reduction was suppressed, and the sizes of the obtained Ag NPs decreased. The amount of H2O2 and the pH of the reduction solutions are therefore highly important parameters for the preparation of well‐dispersed Ag NPs using the MWPLP.
Investigation of Active Center of Cu‐Based Catalyst for Low Temperature Methanol Synthesis from Syngas in Liquid Phase: The Contribution of Cu+ and Cu0
Authors: Liu Huan , Chen Tong , Yang Guang , Wang Gong‐Ying
Published: September 2017

LaCuMn catalyst was prepared under different reduction temperature and passivation time, and used to catalyze CO hydrogenation to methanol in liquid phase. The effect of reductive copper species on the catalytic activity and the product distribution was studied. The results showed that the surface content of reductive copper species greatly affect the catalytic activity and the approximate molar ratio of Cu+ to Cu0 was important. The mixture of CuZn/AC‐N2 with only Cu+ and CuZn/AC‐H2 with only Cu0 was utilized for the low temperature methanol synthesis from syngas in liquid phase. It was confirmed that both of the reductive copper species of Cu+ and Cu0 were active species and Cu+ was superior to Cu0. Moreover, the synergic function of Cu+ and Cu0 led to the enhancement of the catalytic activity of Cu based catalyst, and the optimum molar ratio of surface Cu+ to Cu0 was in the range of 3.5 to 4.0.
Transparent PVDF‐TrFE/Graphene Oxide Ultrathin Films with Enhanced Energy Harvesting Performance
Authors: Wang Yunqiu , Fang Minjie , Tian Bobo , Xiang Pinghua , Zhong Ni , Lin Hechun , Luo Chunhua , Peng Hui , Duan Chun‐Gang
Published: September 2017

Poly(vinylidene fluoride/trifluoroethylene) (PVDF‐TrFE) as a representative organic piezoelectric material have recently attracted wide attention. However, low dielectric permittivity limits its applications. We successfully prepared transparent PVDF‐TrFE/graphene oxide (GO) ultrathin films. The addition of GO greatly improved the dielectric properties of PVDF‐TrFE. The dielectric constant of the composite film is almost three times of that of the PVDF‐TrFE film with the addition of 0.1 wt. % of GO nanosheets. Furthermore, the composite film also exhibits enhanced energy harvesting performance. The electric generator based on the PVDF‐TrFE/ GO ultrathin film shows an output voltages of 49 mV under a pressure of 3.06 KPa. The advantages of transparence, flexibility and better energy harvesting performance make PVDF‐TrFE/GO composite films much more attractive in promising applications of nano/micro electronic devices.
Tunable and Switchable Solid State Fluorescence: Alkyl Chain Length‐Dependent Molecular Conformation and Self‐Reversible Thermochromism
Authors: Hariharan Palamarneri Sivaraman , Gayathri Parthasarathy , Moon Dohyun , Anthony Savarimuthu Philip
Published: September 2017

Flexible alkyl chain has been used to control the molecular conformation, packing and intermolecular interactions of aggregation enhanced emissive (AEE) triphenylamine fluorophore, and tune the fluorescence maxima and mechano/thermochromism. 2‐(4‐(diphenylamino)‐2‐ethoxybenzylidene)malononitrile (DPABM‐2), 2‐(4‐(diphenylamino)‐2‐propoxybenzylidene)malononitrile (DPABM‐3), 2‐(4‐(diphenylamino)‐2‐butoxybenzylidene)malononitrile (DPA‐BM‐4), 2‐(4‐(diphenylamino)‐2‐pentyloxybenzylidene) malono‐nitrile (DPABM‐5), 2‐(4‐(diphenylamino)‐2‐hexyloxybenzylidene) malonon‐itrile (DPABM‐6) and 2‐(4‐(diphenylamino)‐2‐heptyloxybenzylidene) malononitrile (DPABM‐7) exhibited weak to strong solid state fluorescence (absolute quantum yield (Φf)=4 to 26%). DPABM‐2 did not show significant fluorescence changes to external stimuli, however, DPABM‐3 and DPABM‐4 exhibited off‐on fluorescence switching. DPABM‐3 also showed tunable fluorescence via polymorphism. Interestingly, DPABM‐5‐7 showed alkyl chain orientation dependent self‐reversible thermochromism. DPABM‐5 and DPABM‐7 exhibited decrease of fluorescence intensity with temperature whereas DPABM‐6 showed increase of fluorescence intensity. Solid state structural analysis revealed the influence of alkyl chain length on the molecular conformations and packing. Powder X‐ray diffraction (PXRD) studies indicate that phase change of materials from crystalline to amorphous and vice‐versa was responsible for fluorescence switching with external stimuli. Further, AEE of DPABM derivatives and the reactive ethylene‐malononitrile has also been exploited for fabricating hydrazine sensing polymer composite film. Thus simple change of alkyl chain lengths lead to the generation of polymorphism, mechanochromism and temperature dependent self‐reversible fluorescence switching materials.
Selective CO2 Adsorption By Methyl‐Functionalized Metal‐Organic Framework
Authors: Ma Deyun , Li Zhi , Jiang Fei , Ma Yanhua , Lin Wanchun , Wen Meiling , Liu Bei , Xu Jun
Published: September 2017

A hydrophobic porous MOF functionalized by methyl groups with a chemical formula {[Cd2(oba)2(dmbpy)(H2O)]⋅2(EtOH)⋅4(H2O)}n (1) (oba=4,4′‐oxydibenzoate, dmbpy=3,3′‐dimethyl‐4,4′‐bipyridine, EtOH=ethanol) was synthesized and structurally characterized. 1 exhibits a 3D framework with a 1D channel parallel to the c axis. TGA, PXRD, and water vapor sorption results show high thermal and water stability for the framework. More importantly, 1 shows a very high adsorption selectivity to CO2 as compared to other small gas molecules (e. g. CH4, N2, O2, CO and H2) at 298 K based on the results of simulations and experiments.
Genetic Evolution of Glioblastoma Stem-Like Cells From Primary to Recurrent Tumor
Authors: Orzan Francesca , De Bacco Francesca , Crisafulli Giovanni , Pellegatta Serena , Mussolin Benedetta , Siravegna Giulia , D’Ambrosio Antonio , Comoglio Paolo M. , Finocchiaro Gaetano , Boccaccio Carla
Published: September 2017

Glioblastoma (GBM) is a lethal tumor that displays remarkable genetic heterogeneity. It is also known that GBM contains a cell hierarchy driven by GBM stem-like cells (GSCs), responsible for tumor generation, therapeutic resistance, and relapse. An important and still open issue is whether phylogenetically related GSCs can be found in matched primary and recurrent GBMs, and reflect tumor genetic evolution under therapeutic pressure. To address this, we analyzed the mutational profile of GSCs isolated from either human primary GBMs (primary GSCs) or their matched tumors recurring after surgery and chemoradiotherapy (recurrent GSCs). We found that recurrent GSCs can accumulate temozolomide-related mutations over primary GSCs, following both linear and branched patterns. In the latter case, primary and recurrent GSCs share a common set of lesions, but also harbor distinctive mutations indicating that primary and recurrent GSCs derive from a putative common ancestor GSC by divergent genetic evolution. Interestingly, TP53 mutations distinctive of recurrent GSCs were detectable at low frequency in the corresponding primary tumors and likely marked pre-existent subclones that evolved under therapeutic pressure and expanded in the relapsing tumor. Consistently, recurrent GSCs displayed in vitro greater therapeutic resistance than primary GSCs. Overall, these data indicate that (a) phylogenetically related GSCs are found in matched primary and recurrent GBMs and (b) recurrent GSCs likely pre-exist in the untreated primary tumor and are both mutagenized and positively selected by chemoradiotherapy.
Two decades of dendrimers as versatile MRI agents: a tale with and without metals
Authors: McMahon Michael T. , Bulte Jeff W. M.
Published: September 2017

Dendrimers or dendritic polymers are a class of compounds with great potential for nanomedical use. Some of their properties, including their rigidity, low polydispersity and the ease with which their surfaces can be modified make them particularly well suited for use as MRI diagnostic or theranostic agents. For the past 20 years, researchers have recognized this potential and refined dendrimer formulations to optimize these nanocarriers for a host of MRI applications, including blood pool imaging agents, lymph node imaging agents, tumor‐targeted theranostic agents and cell tracking agents. This review summarizes the various types of dendrimers according to the type of MR contrast they can provide. This includes the metallic T1, T2 and paraCEST imaging agents, and the non‐metallic diaCEST and fluorinated (19F) heteronuclear imaging agents.

This article is categorized under:

Diagnostic Tools > In Vivo Nanodiagnostics and Imaging

Implantable Materials and Surgical Technologies > Nanomaterials and Implants
Microbial healing of cracks in concrete: a review
Authors: Joshi Sumit , Goyal Shweta , Mukherjee Abhijit , Reddy M Sudhakara
Published: September 2017

Concrete is the most widely used construction material of the world and maintaining concrete structures from premature deterioration is proving to be a great challenge. Early age formation of micro-cracking in concrete structure severely affects the serviceability leading to high cost of maintenance. Apart from conventional methods of repairing cracks with sealants or treating the concrete with adhesive chemicals to prevent the cracks from widening, a microbial crack-healing approach has shown promising results. The unique feature of the microbial system is that it enables self-healing of concrete. The effectiveness of microbially induced calcium carbonate precipitation (MICCP) in improving durability of cementitious building materials, restoration of stone monuments and soil bioclogging is discussed. Main emphasis has been laid on the potential of bacteria-based crack repair in concrete structure and the applications of different bacterial treatments to self-healing cracks. Furthermore, recommendations to employ the MICCP technology at commercial scale and reduction in the cost of application are provided in this review.
Ocular Dysfunctions Presenting in Tacrolimus‐Induced Posterior Reversible Encephalopathy Syndrome: A Case Presentation
Authors: Brown Cora H. , Feng Alexander J. , Cruz Ernesto
Published: September 2017

The constellation of ocular symptoms known as Balint syndrome is a rare disorder seen in bilateral parieto‐occipital lesions and is most frequently due to arterial occlusive disease or acute hypertension. Here we present the case of a patient with tacrolimus‐induced posterior reversible encephalopathy syndrome (PRES) who presented with optic ataxia, simultanagnosia, and ocular apraxia. These ocular findings, consistent with Balint syndrome, are rarely the initial presentation of PRES. This case highlights the importance of early recognition of this unusual phenomenon, as well as the importance of an individualized rehabilitation plan to maximize functional independence in these patients.

Level of Evidence

V
Nonsurgical Treatment of Delayed‐Onset Brachial Plexopathy Due to Hypertrophic Clavicular Callus: A Case Report
Authors: Carpenter Benjamin M. , Pettersson David R. , Mirarchi Adam J. , Groshong Drew , Carlson Hans L.
Published: September 2017

Clavicular fractures are common injuries that traditionally are managed nonsurgically without clinically significant sequelae. However, they may develop hypertrophic callus formation that compresses the brachial plexus. These cases may present months to years after initial injury with varying degrees of pain, paresthesia, and weakness on the affected side and usually are treated by surgical resection of the hypertrophic callus. We present a case of brachial plexopathy due to hypertrophic clavicular callus causing weakness and paresthesia. The plexopathy was confirmed with imaging and electrodiagnostic studies. This case was unusual in that resolution of symptoms was achieved nonsurgically.

Level of Evidence

V
Proton Pump Inhibitor Use Is Associated With a Reduced Risk of Infection with Intestinal Protozoa
Authors: Sheele Johnathan M.
Published: September 2017

Objective

Proton pump inhibitors (PPIs) can kill some human protozoan parasites in cell culture better than the drug metronidazole. Clinical data showing an antiprotozoal effect for PPIs are lacking. The objective of the study is to determine if PPI use is associated with a reduced risk of having intestinal parasites.

Methods

We obtained electronic medical record data for all persons who received a stool ova and parasite (O & P) examination at our tertiary care academic medical center in Cleveland, Ohio, between January 2000 and September 2014. We obtained the person’s age, whether they were taking a PPI at the time of the O & P examination, and whether the pathology report indicated the presence of any parasites. χ2 with Yates correction was used to determine if PPI use was associated with stool protozoa.

Results

Three intestinal protozoa were identified in 1199 patients taking a PPI (0.3%), and 551 intestinal parasites were identified in the 14,287 patients not taking a PPI (3.9%). There was a statistically significant lower likelihood of finding protozoa in the stool of a person taking a PPI compared with those not taking a PPI ( P < .0001).

Conclusions

Patients taking a PPI were statistically less likely to have an intestinal protozoa reported on stool O & P examination compared with those not taking a PPI.
WHAT THE (EXPLETIVE) IS A “CONSTITUTION”?! ORDINARY CADRES CONFRONT THE 1954 PRC DRAFT CONSTITUTION
Authors: Diamant Neil J.
Published: September 2017

Following the history of western constitutional history, studies of Chinese constitutionalism have tended to focus on its intellectual origins, or, more commonly these days, its failure to restrain official behavior. Drawing upon new archival materials, this article takes a different tack. I zero in on a critical period of constitutional gestation, when officials read the 1954 constitution in draft form, posed questions about its text and suggested revisions. How did officials react when told that citizens, many of whom were recently persecuted, now enjoy “freedom of assembly”? These materials allow us to see “the state” in real time: How did officials understand core legal concepts such as “right,” “constitution” and “citizen” as well as their role in the new polity? In many respects, the discussion surrounding the draft constitution turned out to be a venue for officials to talk about the meaning of the revolution they had just experienced.
Epidemiology of psychotic depression – systematic review and meta-analysis
Authors: Jääskeläinen E. , Juola T. , Korpela H. , Lehtiniemi H. , Nietola M. , Korkeila J. , Miettunen J.
Published: September 2017

Large amount of data have been published on non-psychotic depression (NPD), schizophrenia (SZ), and bipolar disorder, while psychotic depression (PD) as an own entity has received much smaller attention. We performed a systematic review and meta-analyses on epidemiology, especially incidence and prevalence, risk factors, and outcomes of PD. A systematic search to identify potentially relevant studies was conducted using four electronic databases and a manual search. The search identified 1764 unique potentially relevant articles, the final study included 99 articles. We found that the lifetime prevalence of PD varies between 0.35% and 1%, with higher rates in older age. Onset age of PD was earlier than that of NPD in younger samples, but later in older samples. There were no differences in gender distribution in PDv.NPD, but higher proportion of females was found in PD than in SZ or in psychotic bipolar disorder (PBD). Risk factors have rarely been studied, the main finding being that family history of psychosis and bipolar disorder increases the risk of PD. Outcomes of PD were mostly worse when compared with NPD, but better compared with SZ and schizoaffective disorder. The outcome compared with PBD was relatively similar, and somewhat varied depending on the measure of the outcome. Based on this review, the amount of research on PD is far from that of NPD, SZ, and bipolar disorder. Based on our findings, PD seems distinguishable from related disorders and needs more scientific attention.
CARNIVAL AND SACRED DRAMA: SCHÜTZ’SCHRISTMAS HISTORIAAND THE TRANSFORMATION OF CHRISTMAS IN THE SECOND HALF OF THE SEVENTEENTH CENTURY
Authors: Rathey Markus
Published: September 2017

The celebration of Christmas in Early Modern Europe underwent a significant transformation in the second half of the seventeenth century. Even after the Protestant Reformation, European Christmas traditions maintained numerous features of their medieval practices, such as carnivalesque celebrations, processions, masks, and riotous behaviour. This changed during the seventeenth century. Popular carnivalesque Christmas plays were prohibited and replaced with a more internalized devotion that emphasized the individual’s relationship with the newborn Child. This transformation was part of a larger paradigm shift in seventeenth-century religiosity, which replaced external and physical displays of piety with internalized devotional practices. These shifts also included new theologies of corporeality and gender, which likewise had an impact on the ways in which Christmas was celebrated. The theological shifts correlate with the rejection of the carnivalesque in the Early Modern period, as it was analysed by Mikhail Bakhtin.

Most of these changes took place in the 1670s and 1680s. Schütz’s Christmas Historia – which was composed before 1664 – represents a transitional phase and retains some earlier views of Christmas. The most obvious example is the Kindelwiegen (rocking of the child), the physicality of which was highly suspicious to theologians in the later seventeenth century. Schütz not only refers to this practice but incorporates it in the texture of his music.
Validation of a survey to examine drinking-water access, practices and policies in schools
Authors: Hecht Amelie A , Grumbach Jacob M , Hampton Karla E , Hecht Kenneth , Braff-Guajardo Ellen , Brindis Claire D , McCulloch Charles E , Patel Anisha I
Published: September 2017

Objective

Ensuring ready access to free drinking-water in schools is an important strategy for prevention of obesity and dental caries, and for improving student learning. Yet to date, there are no validated instruments to examine water access in schools. The present study aimed to develop and validate a survey of school administrators to examine school access to beverages, including water and sports drinks, and school and district-level water-related policies and practices.

Design

Survey validity was measured by comparing results of telephone surveys of school administrators with on-site observations of beverage access and reviews of school policy documents for any references to beverages. The semi-structured telephone survey included items about free drinking-water access (sixty-four items), commonly available competitive beverages (twenty-nine items) and water-related policies and practices (twenty-eight items). Agreement between administrator surveys and observation/document review was calculated using kappa statistics for categorical variables, and Pearson correlation coefficients and t tests for continuous variables.

Setting

Public schools in the San Francisco Bay Area, California, USA.

Subjects

School administrators (n 24).

Results

Eighty-one per cent of questions related to school beverage access yielded κ values indicating substantial or almost perfect agreement (κ>0·60). However, only one of twenty-eight questions related to drinking-water practices and policies yielded a κ value representing substantial or almost perfect agreement.

Conclusions

This school administrator survey appears reasonably valid for questions related to beverage access, but less valid for questions on water-related practices and policies. This tool provides policy makers, researchers and advocates with a low-cost, efficient method to gather national data on school-level beverage access.
Physiotherapy-as-first-point-of-contact-service for patients with musculoskeletal complaints: understanding the challenges of implementation
Authors: Moffatt Fiona , Goodwin Rob , Hendrick Paul
Published: September 2017

Background

Primary care faces unprecedented challenges. A move towards a more comprehensive, multi-disciplinary service delivery model has been proposed as a means with which to secure more sustainable services for the future. One seemingly promising response has been the implementation of physiotherapy self-referral schemes, however there is a significant gap in the literature regarding implementation.

Aim

This evaluation aimed to explore how the professionals and practice staff involved in the delivery of an in-practice physiotherapy self-referral scheme understood the service, with a focus on perceptions of value, barriers and impact.

Design and setting

A qualitative evaluation was conducted across two UK city centre practices that had elected to participate in a pilot self-referral scheme offering ‘physiotherapy-as-a-first-point-of-contact’ for patients presenting with a musculoskeletal complaint.

Methods

Individual and focus group interviews were conducted amongst participating physiotherapists, administration/reception staff, general practitioners (GPs) and one practice nurse (in their capacity as practice partner). Interview data were collected from a total of 14 individuals. Data were analysed using thematic analysis.

Results

Three key themes were highlighted by this evaluation. First, the imperative of effecting a cultural change – including management of patient expectation with particular reference to the belief that GPs represented the ‘legitimate choice’, re-visioning contemporary primary care as a genuine team approach, and the physiotherapists’ reconceptualisation of their role and practices. Second, the impact of the service on working practice across all stakeholders – specifically re-distribution of work to ‘unburden’ the GP, and the critical role of administration staff. Finally, beliefs regarding the nature and benefits of physiotherapeutic musculoskeletal expertise – fears regarding physiotherapists’ ability to work autonomously or identify ‘red flags’ were unfounded.

Conclusion

This qualitative evaluation draws on the themes to propose five key lessons which may be significant in predicting the success of implementing physiotherapy self-referral schemes.
MHD simulations of coronal dark downflows considering thermal conduction
Authors: Zurbriggen E. , Costa A. , Esquivel A. , Schneiter M. , Cécere M.
Published: September 2017

While several scenarios have been proposed to explain supra-arcade downflows (SADs) observed descending through turbulent hot regions, none of them have systematically addressed the consideration of thermal conduction. The SADs are known to be voided cavities. Our model assumes that SADs are triggered by bursty localized reconnection events that produce non-linear waves generating the voided cavity. These subdense cavities are sustained in time because they are hotter than their surrounding medium. Due to the low density and large temperature values of the plasma we expect the thermal conduction to be an important process. Our main aim here is to study if it is possible to generate SADs in the framework of our model considering thermal conduction. We carry on 2D MHD simulations including anisotropic thermal conduction, and find that if the magnetic lines envelope the cavities, they can be isolated from the hot environment and be identified as SADs.
Modelling short-term Solar Spectral Irradiance (SSI) using coronal electron density and temperature profiles based on solar magnetic field observations
Authors: Gómez J. M. Rodríguez , Vieira L. E. Antunes , Lago A. Dal , Palacios J. , Balmaceda L. A. , Stekel T.
Published: September 2017

Some key physical processes that impact the evolution of Earth's atmosphere on time-scale from days to millennia, such as the EUV emissions, are determined by the solar magnetic field. However, observations of the solar spectral irradiance are restricted to the last few solar cycles and are subject to large uncertainties. We present a physics-based model to reconstruct short-term solar spectral irradiance (SSI) variability. The coronal magnetic field is estimated to employ the Potential Field Source Surface extrapolation (PFSS) based on observational synoptic charts and magnetic flux transport model. The emission is estimated to employ the CHIANTI atomic database 8.0. The performance of the model is compared to the emission observed by TIMED/SORCE.
Possible effects on Earth's climate due to reduced atmospheric ionization by GCR during Forbush Decreases
Authors: Portugal Williamary , Echer Ezequiel , de Souza Echer Mariza Pereira , Pacini Alessandra Abe
Published: September 2017

This work presents the first results of a study about possible effects on the surface temperature during short periods of lower fluxes of Galactic Cosmic Rays at Earth, called Forbush Decreases. There is a hypothesis that the Galactic Cosmic Ray flux decreases cause changes on the physical-chemical properties of the atmosphere. We have conducted a study to investigate these possible effects on several latitudinal regions, around the ten strongest FDs occurred from 1987 to 2015. We have found a possible increase on the surface temperature at middle and high latitudes during the occurence of these events.
Low-mass eclipsing binaries in the WFCAM Transit Survey
Authors: Cruz Patricia , Diaz Marcos , Barrado David , Birkby Jayne
Published: September 2017

The characterization of short-period detached low-mass binaries, by the determination of their physical and orbital parameters, reveal the most precise basic parameters of low-mass stars. Particularly, when photometric and spectroscopic data of eclipsing binaries (EBs) are combined. Recently, 16 new low-mass EBs were discovered by the WFCAM Transit Survey (WTS), however, only three of them were fully characterized. Therefore, new spectroscopic data were already acquired with the objective to characterize five new detached low-mass EBs discovered in the WTS, with short periods between 0.59 and 1.72 days. A preliminary analysis of the radial velocity and light curves was performed, where we have derived orbital separations of 2.88 to 6.69 R⊙, and considering both components, we have found stellar radii ranging from 0.40 to 0.80 R⊙, and masses between 0.24 and 0.71 M⊙. In addition to the determination of the orbital parameters of these systems, the relation between mass, radius and orbital period of these objects can be investigated in order to study the mass-radius relationship and the radius anomaly in the low main-sequence.