bluuebunny/crossref_metadata_2025_split huggingface dataset:
Besondere Herausforderungen beim Bau der neuen Unterinntalbahn
Authors: Saischek Michael , Kölbach Peter 
Published: July 2013

AbstractDie Herausforderungen bei der Umsetzung von Großprojekten sind vielfältig. Im Projektmanagement liegen sie darin, den Überblick über das Gesamtvorhaben zu bewahren, die Nahtstellen zwischen den Projektbeteiligten zu koordinieren und das Projekt im Spannungsfeld zwischen Terminen, Kosten und Qualität im Hinblick auf die Lebenszykluskosten zu optimieren. Andererseits ist aber auch eine Vielzahl von technischen Hürden zu meistern. Die Erschütterungsschutzmaßnahmen bei der neuen Unterinntalbahn werden exemplarisch für diese unzähligen technischen Herausforderungen näher betrachtet.Um die vorgeschriebenen, sehr niedrigen Immissionsgrenzwerte für Erschütterungen und Sekundärluftschall im bereits hochbelasteten und dichtbesiedelten Unterinntal einzuhalten, sind hochwertige und dauerhaft wirksame Schutzmaßnahmen erforderlich. Eine dem Stand der Technik entsprechende Schutzmaßnahme ist der Einbau von Masse‐Feder‐Systemen, die die erforderlichen lokalen Anforderungen an die Schutzziele bestmöglich erfüllen.Particular challenges during the construction of the new Lower Inn Valley Railway LineThe challenges in the implementation of major projects are diverse. On the one hand, the challenges lie in project management trying to maintain an overview of the entire project and to coordinate the interfaces between the project participants and to optimize the project given the tension between deadlines, costs and quality in terms of life cycle costs. On the other hand, there are also a variety of technical hurdles to overcome. The vibration protection measures in the new Unterinntalbahn be considered an example for so many of these technical challenges in more detail.To comply with the prescribed very low emission limit for shock and secondary airborne noise in the already highly noise exposed and densely populated Lower Inn Valley, high quality and permanently effective protection measures are required. One state‐of‐the‐art protection measure used is the installation of mass‐spring systems that meet the necessary requirements for local protection.
Validated spectrofluorimetric method for the determination of tamsulosin in spiked human urine, pure and pharmaceutical preparations
Authors: Karasakal A. , Ulu S. T. 
Published: July 2013

ABSTRACTA novel, sensitive and selective spectrofluorimetric method was developed for the determination of tamsulosin in spiked human urine and pharmaceutical preparations. The proposed method is based on the reaction of tamsulosin with 1‐dimethylaminonaphthalene‐5‐sulfonyl chloride in carbonate buffer pH 10.5 to yield a highly fluorescent derivative. The described method was validated and the analytical parameters of linearity, limit of detection (LOD), limit of quantification (LOQ), accuracy, precision, recovery and robustness were evaluated. The proposed method showed a linear dependence of the fluorescence intensity on drug concentration over the range 1.22 × 10‐7 to 7.35 × 10‐6 M. LOD and LOQ were calculated as 1.07 × 10‐7 and 3.23 × 10‐7 M, respectively. The proposed method was successfully applied for the determination of tamsulosin in pharmaceutical preparations and the obtained results were in good agreement with those obtained using the reference method. Copyright © 2013 John Wiley & Sons, Ltd.
Identification of the metabolites of anti‐inflammatory compound clematichinenoside AR in rat intestinal microflora
Authors: Li Feng , Wang Dawei , Xu Ping , Wu Jie , Liu Li , Liu Xiaodong 
Published: July 2013

ABSTRACTClematichinenoside AR (C‐AR), a pentacyclic triterpenoid saponin with anti‐inflammatory and anti‐rheumatoid activities, is the main active component of the traditional Chinese medicine Clematidis Radix et Rhizoma. However, its poor oral absorption indicated that not only the parent compound C‐AR itself, but also its metabolites could be responsible for the pharmacological effects in rats. The present study aimed to investigate the metabolism of C‐AR in rat intestinal microflora, where C‐AR was extensively metabolized. C‐AR was incubated with the content of the large intestine. The culture solution was collected at different time points and analyzed for the metabolites of C‐AR. Eight metabolites were identified by liquid chromatography/quadrupole time‐of‐flight mass spectrometry. M1, M2 and M5 were the major metabolites. In addition, it was proposed that deglycosylation was the only pathway contributing to the biotransformation of C‐AR in rat intestinal microflora. Copyright © 2013 John Wiley & Sons, Ltd.
Chemical Composition and Antimicrobial Activity of the Essential Oil of Stachys officinalis (L.) Trevis. (Lamiaceae)
Authors: Lazarević Jelena S. , Ðorđević Aleksandra S. , Kitić Dušanka V. , Zlatković Bojan K. , Stojanović Gordana S. 
Published: July 2013

AbstractCharacterization by GC‐FID and GC/MS analyses of the Stachys officinalis (L.) Trevis. essential oil obtained by hydrodistillation of the aerial parts allowed the identification of 190 components that represented 97.9% of the total oil content. The main constituents identified were germacrene D (19.9%), β‐caryophyllene (14.1%), and α‐humulene (7.5%). Terpenoids were by far predominant (89.4%), with sesquiterpene hydrocarbons (69.1%) and oxygenated sesquiterpenes (14.8%) being the most abundant compounds detected in the oil. Based on the present and previously published results, multivariate statistical comparison of the chemical composition of the essential oils was performed within the species. Principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) of the data on the volatile profiles of S. officinalis taxa revealed no pronounced differences among the samples originated from the Balkan Peninsula. Additionally, the oil was screened for in vitro antibacterial and antifungal activity using the broth microdilution assay. The oil's best antimicrobial activities were obtained against the mold Aspergillus niger (minimal inhibitory (MIC) and minimal fungicidal (MFC) concentrations of 2.5 and 5.0 mg/ml, resp.) and the yeast Candida albicans (MIC and MFC of 5.0 mg/ml).
Cyclopaldic Acid, Seiridin, and Sphaeropsidin A as Fungal Phytotoxins, and Larvicidal and Biting Deterrents against Aedes aegypti (Diptera: Culicidae): StructureActivity Relationships
Authors: Cimmino Alessio , Andolfi Anna , Avolio Fabiana , Ali Abbas , Tabanca Nurhayat , Khan Ikhlas A. , Evidente Antonio 
Published: July 2013

AbstractAedes aegypti L. is the major vector of the arboviruses responsible for dengue fever, one of the most devastating human diseases. From a preliminary screening of fungal phytotoxins, cyclopaldic acid (1), seiridin (2), sphaeropsidin A (4), and papyracillic acid (5) were evaluated for their biting deterrent and larvicidal activities against Ae. aegypti L. Because compounds 1, 2, 4, and 5 exhibited mosquito biting deterrent activities and 1 and 4 demonstrated larvicidal activities, further structureactivity relationship studies were initiated on these toxins. In biting‐deterrence bioassays, 1, 2, 4, and 5, 3,8‐didansylhydrazone of cyclopaldic acid, 1F, 5‐azidopentanoate of cyclopaldic acid A, 1G, the reduced derivative of cyclopaldic acid, 1 H, isoseiridin (3), 2′‐O‐acetylseiridin (2A), 2′‐oxoseiridin (2C), 6‐O‐acetylsphaeropsidin A (4A), 8,14‐methylensphaeropsidin A methyl ester (4B), and sphaeropsidin B (4C) showed activities higher than the solvent control. Sphaeropsidin B (4C) was the most active compound followed by 2A, while the other compounds were less active. Biting‐deterrence activity of compound 4C was statistically similar to DEET. In the larvicidal screening bioassays, only compounds 1 and 4 demonstrated larvicidal activities. Based on LD50 values, compound 4 (LD50 36.8 ppm) was significantly more active than compound 1 (LD50 58.2 ppm). However, the activity of these compounds was significantly lower than permethrin.
Biogeographical Patterns and Phenological Changes in Lapiedra martineziiLag. Related to Its Alkaloid Diversity
Authors: Ríos Segundo , Berkov Strahil , Martínez‐Francés Vanessa , Bastida Jaume 
Published: July 2013

AbstractThe aim of this work was to investigate the alkaloid patterns of Lapiedra martinezii and their relation to biogeography and phenology focused in a phylogenetic comparison. Plants from 14 populations of L. martinezii, covering almost its entire distribution area, were subjected to morphological, ecological, and phytochemical analysis. Experiments for different alkaloid‐type content are proposed as a new tool for analysis of plant distribution. Several plants were transplanted for weekly observation of their phenological changes, and alkaloids from different plant organs were extracted, listed, and compared. The alkaloid pattern of L. martinezii comprises 49 compounds of homolycorine, lycorine, tazettine, haemantamine, and narciclasine types. The populations located in the north and south margins of the distribution area displayed alkaloid patterns different from those of the central area. Changes in these patterns during their phenological cycle may be related to a better defence for plant reproduction. L. martinezii is an old relict plant, and it has maintained some of the more primitive morphological features and alkaloid profiles of the Mediterranean Amaryllidaceae. The variations in alkaloid content observed could be interpreted in a phylogenetic sense, and those found in their phenological changes, in an adaptive one.
Structural Characterization and Chemical Classification of Some Bryophytes Found in Latvia
Authors: Maksimova Viktorija , Klavina Laura , Bikovens Oskars , Zicmanis Andris , Purmalis Oskars 
Published: July 2013

AbstractBryophytes are the second largest taxonomic group in the plant kingdom; yet, studies conducted to better understand their chemical composition are rare. The aim of this study was to characterize the chemical composition of bryophytes common in Northern Europe by using elemental, spectral, and non‐destructive analytical methods, such as Fourier transform IR spectrometry (FT‐IR), solid‐phase 13C‐NMR spectrometry, and pyrolysis‐gas chromatography/mass spectrometry (Py‐GC/MS), for the purpose of investigating their chemotaxonomic relationships on the basis of chemical‐composition data. The results of all these analyses showed that bryophytes consist mainly of carbohydrates. Judging by FT‐IR spectra, the OH groups in combination of CO groups were the most abundant groups. The 13C‐NMR spectra provided information on the presence of such compounds as phenolics and lipids. It was found that the amount of phenolic compounds in bryophytes is relatively small. This finding definitely confirmed the absence of lignin in the studied bryophytes. Cluster analysis was used to better understand differences in the chemical composition of bryophyte samples and to evaluate possible usage of these methods in the chemotaxonomy of bryophytes.
Naphtho‐γ‐pyrones from Endophyte Aspergillus niger Occurring in the Liverwort Heteroscyphus tener (Steph.) Schiffn.
Authors: Li Xiao‐Bin , Xie Fei , Liu Shan‐Shan , Li Ying , Zhou Jin‐Chuan , Liu Yong‐Qing , Yuan Hui‐Qing , Lou Hong‐Xiang 
Published: July 2013

AbstractBioactivity‐guided fractionation of the cytotoxic extract of Aspergillus niger, an endophytic fungus from the Chinese liverwort Heteroscyphus tener (Steph.) Schiffn., afforded five new naphtho‐γ‐pyrones, rubrofusarin‐6‐O‐α‐D‐ribofuranoside (1), (R)‐10‐(3‐succinimidyl)‐TMC‐256A1 (2), asperpyrone E (3), isoaurasperone A (4), and isoaurasperone F (5), as well as four known ones, dianhydroaurasperone C (6), aurasperone D (7), asperpyrone D (8), and asperpyrone A (9), together with a cytotoxic cyclic pentapeptide, malformin A1 (10). Their structures were determined by extensive spectroscopic analysis. The absolute configurations of dimeric naphtho‐γ‐pyrones 3–9 were also determined by analysis of their respective CD spectra.
Enantiomeric and Diastereoisomeric (Mixed) L/ D‐Octaarginine Derivatives – A Simple Way of Modulating the Properties of Cell‐Penetrating Peptides
Authors: Purkayastha Nirupam , Eyer Klaus , Robinson Tom , Dittrich Petra S. , Beck Albert K. , Seebach Dieter , Kolesinska Beata , Cadalbert Riccardo 
Published: July 2013

AbstractCell‐penetrating peptides (CPPs) are promising vehicles for delivery of drugs, antibiotics, proteins, nucleic acid derivatives, etc. into eukaryotic and prokaryotic target cells. To prevent premature degradation, CPPs consisting of D‐ or β‐amino acid residues have been used. We present simple models for the various modes of delivery of physiologically active cargoes by CPPs, depending on the nature of their conjugation (Fig. 1), and we describe the plasma stability of oligoarginines (OAs) 1–4, the most common unnatural CPPs. Fluorescein‐labeled L‐octaarginine 1 was found to have a half‐life (t1/2) of <0.5 min, the D‐enantiomer (2) of >7 d (Fig. 2). For possible medicinal applications, the former type of derivative would be too unstable, and the latter one undesirably persistent. Thus, seven of the 256 possible ‘mixed’ Flua‐L/D‐octaarginine amides, 4a–4g, were synthesized and shown to have half‐lives in heparine‐stabilized human plasma between 8 min and 5.5 h (Figs. 3 and 4). The cell penetration of the new OAs was investigated with ‘healthy’ and with apoptotic HEK cells (Figs. 5–8), and their interactions with phospholipid bilayers were studied, using anionic lipid vesicles (Figs. 9 and 10). There are surprisingly large differences in the rates of cell penetration and binding to vesicle walls between the various stereoisomeric octaarginine derivatives 1, 2, and 4a–4g (Figs. 5 and 7). – The role of D‐amino acids and D‐peptides in nature and in drug design is briefly discussed and referenced.
Light‐Induced Bistability in the 2 D Coordination Network {[Fe(bbtr)3][BF4]2}∞: Wavelength‐Selective Addressing of Molecular Spin States
Authors: Chakraborty Pradip , Pillet Sebastien , Bendeif El‐Eulmi , Enachescu Cristian , Bronisz Robert , Hauser Andreas 
Published: July 2013

AbstractWhereas the neat polymeric FeII compound {[Fe(bbtr)3][ClO4]2}∞ (bbtr=1,4‐di(1,2,3‐triazol‐1‐yl)butane) shows an abrupt spin transition centered at 107 K facilitated by a crystallographic symmetry breaking, in the covalently linked 2D coordination network of {[Fe(bbtr)3][BF4]2}∞, FeII stays in the high‐spin state down to 10 K. However, strong cooperative effects of elastic origin result in reversible, persistent, and wavelength‐selective photoswitching between the low‐spin and high‐spin manifolds. This compound thus shows true light‐induced bistability below 100 K. The persistent bidirectional optical switching behavior is discussed as a function of temperature, irradiation time, and intensity. Crystallographic studies reveal a photoinduced symmetry breaking and serve to establish the correlation between structure and cooperative effects. The static and kinetic behavior is explicated within the framework of the mean‐field approximation.
Modular Columnar Supramolecular Polymers as Scaffolds for Biomedical Applications
Authors: Petkau‐Milroy Katja , Sonntag Michael H. , Brunsveld Luc 
Published: July 2013

AbstractSelf‐assembly of discotic molecules into supramolecular polymers offers a flexible approach for the generation of multicomponent one‐dimensional columnar architectures with tuneable biomedical properties. Decoration with ligands induces specific binding of the self‐assembled scaffold to biological targets. The modular design allows the easy co‐assembly of different discotics for the generation of probes for targeted imaging and cellular targeting with adjustable ligand density and composition.
A Conformationally Flexible Dinuclear PtII Complex with Differential Behavior of its Two States toward Quadruplex DNA
Authors: von Grebe Philipp , Suntharalingam Kogularamanan , Vilar Ramon , Sanz Miguel Pablo J. , Herres‐Pawlis Sonja , Lippert Bernhard 
Published: July 2013

AbstractThe reaction of tetrakis(pyridine‐2‐yl)pyrazine (tppz) with 2 equiv of (2,2′‐bpy)PtII in water yields two isomeric dinuclear cations, [{Pt(2,2′‐bpy)}2(tppz)]4+, in which Pt coordination exclusively takes place through the two pairs of pyridine‐2‐yl nitrogen atoms. The two conformational isomers differ in their overall shape, with the formation of “Z” and “U” shapes, which are formed at 40 °C (Z isomer, 1) and under reflux conditions (U isomer, 2), respectively. X‐ray crystal‐structure analyses of the Z isomer, [{Pt(2,2′‐bpy)}2(tppz)](PF6)4⋅3 CHCl3⋅4 H2O (1 a), and of the U isomer, [{Pt(2,2′‐bpy)}2](PF6)4⋅2 CH3CN⋅1.5 H2O (2 a), were carried out. Co‐crystallization of compound 2 with PtCl2(2,2′‐bpy) yielded [{Pt(2,2′‐bpy)}2(tppz)](BF4)4⋅[PtCl2(2,2′‐bpy)]⋅4.5 H2O (3), in which the PtCl2(2,2′‐bpy) entity was sandwiched between the two 2,2′‐bpy faces of the U‐shaped cation (2). Quantum chemical calculations revealed that the U isomer was more stable than the Z isomer, both in the gas phase and in an aqueous environment. These two isomers display different affinities toward duplex DNA and human telomeric quadruplex DNA (Htelo), as concluded from CD spectroscopy and FID assays. Thus, the U isomer binds significantly more strongly to quadruplex DNA (DC50=0.38 μM) than the Z isomer (DC50=8.50 μM).
Cu‐Catalyzed Formal Methylative and Hydrogenative Carboxylation of Alkynes with Carbon Dioxide: Efficient Synthesis of α,β‐Unsaturated Carboxylic Acids
Authors: Takimoto Masanori , Hou Zhaomin 
Published: July 2013

AbstractThe sequential hydroalumination or methylalumination of various alkynes catalyzed by different catalyst systems, such those based on Sc, Zr, and Ni complexes, and the subsequent carboxylation of the resulting alkenylaluminum species with CO2catalyzed by an N‐heterocyclic carbene (NHC)–copper catalyst have been examined in detail. The regio‐ and stereoselectivity of the overall reaction relied largely on the hydroalumination or methylalumination reactions, which significantly depended on the catalyst and alkyne substrates. The subsequent Cu‐catalyzed carboxylation proceeded with retention of the stereoconfiguration of the alkenylaluminum species. All the reactions could be carried out in one‐pot to afford efficiently a variety of α,β‐unsaturated carboxylic acids with well‐controlled configurations, which are difficult to construct by previously reported methods. This protocol could be practically useful and attractive because of its high regio‐ and stereoselectivity, simple one‐pot reaction operation, and the use of CO2as a starting material.
Self‐Assembly versus Stepwise Synthesis: Heterometal–Organic Frameworks Based on Metalloligands with Tunable Luminescence Properties
Authors: Zhang Shu‐Ran , Du Dong‐Ying , Tan Ke , Qin Jun‐Sheng , Dong Hui‐Qing , Li Shun‐Li , He Wen‐Wen , Lan Ya‐Qian , Shen Ping , Su Zhong‐Min 
Published: July 2013

AbstractA new family of heterometal–organic frameworks has been prepared by two synthesis strategies, in which IFMC‐26 and IFMC‐27 are constructed by self‐assembly and IFMC‐28 is obtained by stepwise synthesis based on the metalloligand (IFMC=Institute of Functional Material Chemistry). IFMC‐26 is a (3,6)‐connected net and IFMC‐27 is a (4,8)‐connected 3D framework. The metalloligands {Ni(H4L)}(NO3)2 are connected by binuclear lanthanide clusters giving rise to a 2D sheet structure in IFMC‐28. Notably, IFMC‐26‐EuxTby and IFMC‐28‐EuxTby have been obtained by changing the molar ratios of raw materials. Owing to the porosity of IFMC‐26, Tb3+@IFMC‐26‐Eu and Eu3+@IFMC‐26‐Tb are obtained by postencapsulating TbIII and EuIII ions into the pores, respectively. Tunable luminescence in metal–organic frameworks is achieved by the two kinds of doping methods. In particular, the quantum yields of heterometal–organic frameworks are apparently enhanced by postencapsulation of LnIII ions.
Formation and Geometrical Control of Polygon‐Like Metal‐Coordination Assemblies
Authors: Maeda Hiromitsu , Akuta Ryo , Bando Yuya , Takaishi Kazuto , Uchiyama Masanobu , Muranaka Atsuya , Tohnai Norimitsu , Seki Shu 
Published: July 2013

AbstractPolygon‐like [2+2]‐ and [3+3]‐type metal complexes were prepared from dipyrrin dimers connected by acute‐angled spacers. The electrical conduction depends strongly on the packing alignment of the compounds, revealing the presence of effective hopping pathways for holes with relatively high mobility up to 0.11 cm2 V−1 s−1 along the aligned axis of [3+3]‐type metal‐bridged assemblies. These observations correlated with the geometrical control of the π‐conjugated metal complexes in the cyclic structures, which enables their ordered arrangement in the assemblies.
Preparative Separation of Enantiomers Based on Functional Nucleic Acids Modified Gold Nanoparticles
Authors: Huang Rong , Wang Daifang , Liu Shuzhen , Guo Longhua , Wang Fangfang , Lin Zhenyu , Qiu Bin , Chen Guonan 
Published: July 2013

ABSTRACTThe preparative‐scale separation of chiral compounds is vitally important for the pharmaceutical industry and related fields. Herein we report a simple approach for rapid preparative separation of enantiomers using functional nucleic acids modified gold nanoparticles (AuNPs). The separation of DL‐tryptophan (DL‐Trp) is demonstrated as an example to show the feasibility of the approach. AuNPs modified with enantioselective aptamers were added into a racemic mixture of DL‐Trp. The aptamer‐specific enantiomer (L‐Trp) binds to the AuNPs surface through aptamer‐L‐Trp interaction. The separation of DL‐Trp is then simply accomplished by centrifugation: the precipitate containing L‐Trp bounded AuNPs is separated from the solution, while the D‐Trp remains in the supernatant. The precipitate is then redispersed in water. The aptamer is denatured under 95 °C and a second centrifugation is then performed, resulting in the separation of AuNPs and L‐Trp. The supernatant is finally collected to obtain pure L‐Trp in water. The results show that the racemic mixture of DL‐Trp is completely separated into D‐Trp and L‐Trp, respectively, after 5 rounds of repeated addition of fresh aptamer‐modified AuNPs to the DL‐Trp mixture solution. Additionally, the aptamer‐modified AuNPs can be repeatedly used for at least eight times without significant loss of its binding ability because the aptamer can be easily denatured and renatured in relatively mild conditions. The proposed approach could be scaled up and extended to the separation of other enantiomers by the adoption of other enantioselective aptamers. Chirality 25:751–756, 2013. © 2013 Wiley Periodicals, Inc.
Self‐Assembly Structures of 1H‐Indazoles in the Solution and Solid Phases: A Vibrational (IR, FIR, Raman, and VCD) Spectroscopy and Computational Study
Authors: Avilés Moreno J. R. , Quesada Moreno M. M. , López González J. J. , Claramunt R. M. , López C. , Alkorta I. , Elguero J. 
Published: July 2013

Abstract1H‐indazoles are good candidates for studying the phenomena of molecular association and spontaneous resolution of chiral compounds. Thus, because the 1H‐indazoles can crystallize as dimers, trimers, or catemers, depending on their structure and the phase that they are in, the difficulty in the experimental analysis of the structure of the family of 1H‐indazoles becomes clear. This difficulty leads us to contemplate several questions: How can we determine the presence of different structures of a given molecular species if they change according to the phase? Could these different structures be present in the same phase simultaneously? How can they be determined? To shed light on these questions, we outline a very complete strategy by using various vibrational spectroscopic techniques that are sensitive (VCD) and insensitive (IR, FIR, and Raman) towards the chirality, together with quantum chemical calculations.