bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorescent Probes and Delivery Methods for Single‐Molecule Experiments
Authors: Lymperopoulos Konstantinos , Kiel Alexander , Seefeld Anne , Stöhr Katharina , Herten Dirk‐Peter 
Published: December 2009

AbstractThe recent explosion in papers utilising single‐molecule experiments pushes the envelope further for increased spatial and temporal resolution. In order to achieve this, a combination of novel fluorescent probes and spectroscopy techniques are required. Herein, we provide an overview on our contribution to developments in the field of fluorescent probes along with a palette of alternative delivery methods for introducing the probes into living cells. We discuss probe requirements arising from the use of single‐molecule spectroscopy methods and the customisation of probes that depends on the target molecule, the chemical state of the molecule as well as the distance and the type of interaction between sensor and ligand. We explain how Förster resonance energy transfer (FRET) and photon‐induced electron transfer (PET) can increase the probe customisation. We also discuss additional requirements that arise when performing experiments in living cells like toxicity and cell permeability. Regarding the latter, we devote a special paragraph on the different ways to introduce the desired probe into the cell and how the different properties of each probe and cell type may require different delivery methods. We offer insights based on our experience working with a variety of single‐molecule methods, fluorescent probes and delivery systems. Overall, we encompass the latest developments on probe design and delivery and illustrate that the wealth of information provided by single‐molecule studies goes along with increased complexity.
Gas‐Phase Kinetics of Chlorosilylene Reactions II. ClSiH + C2H4: Absolute Rate Measurements and Quantum Chemical and RRKM Calculations for the Prototype π Addition Reaction
Authors: Becerra Rosa , Boganov Sergey E. , Egorov Mikhail P. , Krylova Irina V. , Nefedov Oleg M. , Promyslov Vladimir M. , Walsh Robin 
Published: December 2009

AbstractTime‐resolved studies of chlorosilylene, ClSiH, generated by the 193 nm laser flash photolysis of 1‐chloro‐1‐silacyclopent‐3‐ene, are carried out to obtain rate constants for its bimolecular reaction with ethene, C2H4, in the gas‐phase. The reaction is studied over the pressure range 0.13–13.3 kPa (with added SF6) at five temperatures in the range 296–562 K. The second order rate constants, obtained by extrapolation to the high pressure limits at each temperature, fitted the Arrhenius equation: log(k∞/cm3 molecule−1 s−1)=(−10.55±0.10) + (3.86±0.70) kJ mol−1/RT ln10. The Arrhenius parameters correspond to a loose transition state and the rate constant at room temperature is 43 % of that for SiH2 + C2H4, showing that the deactivating effect of Cl‐for‐H substitution in the silylene is not large. Quantum chemical calculations of the potential energy surface for this reaction at the G3MP2//B3LYP level show that, as well as 1‐chlorosilirane, ethylchlorosilylene is a viable product. The calculations reveal how the added effect of the Cl atom on the divalent state stabilisation of ClSiH influences the course of this reaction. RRKM calculations of the reaction pressure dependence suggest that ethylchlorosilylene should be the main product. The results are compared and contrasted with those of SiH2 and SiCl2 with C2H4.
Structural Identification of Spectroscopic Substates in Neuroglobin
Authors: Nienhaus Karin , Lutz Stephan , Meuwly Markus , Nienhaus G. Ulrich 
Published: December 2009

AbstractThe structural origins of infrared absorptions of photodissociated CO in murine neuroglobin (Ngb) are determined by combining Fourier transform infrared (FTIR) spectroscopy and molecular dynamics (MD) simulations. Such an approach allows to identify and characterize both the different conformations of the Ngb active site and the transient ligand docking sites. To capture the influence of the protein environment on the spectroscopy and dynamics, experiments and simulations are carried out for the wild type protein and its F28L and F28W mutants. It is found that a voluminous side chain at position 28 divides site B into two subsites, B’ and B”. At low temperatures, CO in wt Ngb only migrates to site B’ from where it can rebind, and B” is not populated. The spectra of CO in site B’ for wt Ngb from simulations and experiments are very similar in spectral shift and shape. They both show doublets, red‐shifted with respect to gas‐phase CO and split by≈8 cm−1. The FTIR spectra of the F28L mutant show additional bands which are also found in the simulations and can be attributed to CO located in substate B”. The different bands are mainly related to different orientations of the His64 side chain with respect to the CO ligand. Large red‐shifts arise from strong interactions between the HistidineNH and the CO oxygen. After dissociation from the heme iron, the CO ligand visits multiple docking sites. The locations of the primary docking site B and a secondary site C, which corresponds to the Mb Xe4 cavity, could be identified unambiguously. Finally, by comparing experiment and simulations it is also possible to identify protonation of its ε position (Hisε64 NgbCO) as the preferred heme‐bound conformation in the wild type protein with a signal at 1935 cm−1.
Elimination of Biological Contaminations from Surfaces by Plasma Discharges: Chemical Sputtering
Authors: Rauscher Hubert , Kylián Ondřej , Benedikt Jan , von Keudell Achim , Rossi François 
Published: December 2009

AbstractPlasma treatment of surfaces as a sterilisation or decontamination method is a promising approach to overcome limitations of conventional techniques. The precise characterisation of the employed plasma discharges, the application of sensitive surface diagnostic methods and targeted experiments to separate the effects of different agents, have led to rapid progress in the understanding of different relevant elementary processes. This contribution provides an overview of the most relevant and recent results, which reveal the importance of chemical sputtering as one of the most important processes for the elimination of biological residuals. Selected studies on the interaction of plasmas with bacteria, proteins and polypeptides are highlighted, and investigations employing beams of atoms and ions confirming the prominent role of chemical sputtering are presented. With this knowledge, it is possible to optimize the plasma treatment for decontamination/sterilisation purposes in terms of discharge composition, density of active species and UV radiation intensity.
E‐cadherin expression in male urethral smears and correlation with PCR‐based detection of human papillomavirus infection
Authors: Tena‐Suck Martha Lilia , Alarcón America , Rösl Franck , la Vega Horacio Astudillo‐de 
Published: December 2009

AbstractWe performed cytological examination of urethral brushing to study aberrant E‐Cadherin expression as a possible marker for papillomavirus in cytological samples.A total of 30 cytobrush male urethral smears were examined E‐cadherin expression and human papillomavirus (hpv) was confirmed using PCR‐DNA.The age range was 19–36 years (mean: 27 years), 17 (56.7%) cases corresponded to low‐risk HPV and 13 (43.3%) cases were high‐risk HPV. The mean age ranges were 25.77 ± 5.90 years for high‐risk HPV and 26.77 ± 4.31years for low‐risk HPV.Pap smears showed dyskeratosis in 23 (76.7%) cases, koilocytes in 13 (43.3%) cases, infection or bacterial background in 14 (43.7%) cases, suggestive changes of Gardnerella infection in 7 (23.3%) cases, and Chlamydia in 3 (10%) cases.Immunohistochemistry was positive for membrane E‐Cadherin; there was weak expression in 13 (43.3%) cases, moderate expression in 11 (36.7%) cases (P = 0.109) (Figs. 3a and b), and strong expression in 6 (20%) cases. There were a statistically significant correlations between E‐Cadherin expression and koilocytes (P = 0.007), individual cell dyskeratosis (P = 0.041), and HPV risk (P = 0.000).We concluded that the loss of E‐Cadherin membrane expression was greater in high‐risk HPV cases and was associated with individual cell dyskeratosis features and koilocytes. There were statistically significant correlations between E‐Cadherin expression and dyskeratosis (P = 0.043), koilocytes (P = 0.007), and type of HPV (P = 0.000). Using male urethral smears to test for the loss of E‐Cadherin membrane expression is simple, rapid, specific and more sensitive than conventional morphologic observations. We concluded that E‐Cadherin can be used to discriminate between high‐ and low‐risk papillomavirus in urethral cytologic specimens. Diagn. Cytopathol. 2010;38:583–589. 2009 Wiley‐Liss, Inc.
Nanoparticle technology: amplifying the effective sensitivity of biomarker detection to create a urine test for hGH
Authors: Fredolini Claudia , Tamburro Davide , Gambara Guido , Lepene Benjamin S. , Espina Virginia , Petricoin III Emanuel F. , Liotta Lance A. , Luchini Alessandra 
Published: December 2009

AbstractSeveral clinical‐grade immunoassays exist for the specific measurement of hGH or its isoforms in blood but there is an urgent need to apply these same reliable assays to the measurement of hGH in urine as a preferred ‘non‐invasive’ biofluid. Unfortunately, conventional hGH immunoassays cannot attain the sensitivity required to detect the low concentrations of hGH in urine. The lowest limit of sensitivity for existing hGH immunoassays is >50 pg/mL, while the estimated concentration of urinary hGH is about 1 pg/m—50 times lower than the sensitivity threshold. We have created novel N‐isopropylacrylamide (NIPAm)‐based hydrogel nanoparticles functionalized with an affinity bait. When introduced into an analyte‐containing solution, the nanoparticles can perform, in one step, (1) complete harvesting of all solution phase target analytes, (2) full protection of the captured analyte from degradation and (3) sequestration of the analyte, effectively increasing the analyte concentration up to a hundredfold. N‐isopropylacrylamide nanoparticles functionalized with Cibacron Blue F3GA bait have been applied to raise the concentration of urinary hGH into the linear range of clinical grade immunoassays. This technology now provides an opportunity to evaluate the concentration of hGH in urine with high precision and accuracy. Copyright © 2009 John Wiley & Sons, Ltd.
NMR Spectroscopic Studies of Palladium(II) Complexes of Bidentate Diphenylphosphane Ligands with Acetate and Tosylate Anions: Complex Formation and Structures
Authors: Mooibroek Tiddo J. , Bouwman Elisabeth , Lutz Martin , Spek Anthony L. , Drent Eite 
Published: December 2009

AbstractThe synthetic pathways towards PdII complexes of functionalized bidentate diphenylphosphane ligands of the type [Pd(ligand)(anion)2] and [Pd(ligand)2](anion)2 have been investigated. Eighteen different ligands have been used in combination with strongly (acetate, OAc–) or weakly (tosylate, OTs–) coordinating anions. The solid‐state structure of some representative complexes was determined with X‐ray crystallography. It is shown that the solid‐state structures are fully retained in solution. The formation of [Pd(ligand)(anion)2]‐type complexes was studied in detail by 1H‐ and 31P‐NMR spectroscopy. Depending on the ligand structure, the complex is formed instantaneously, via a polynuclear intermediate or is not formed at all. Complex formation is demonstrated to depend on the length and rigidity of the ligand backbone and on the steric bulk at the ortho position of the phenyl rings on phosphorus. It was also found that the coordinating ability of the anions can alter the structure of the kinetic and/or thermodynamic product.
Diastereoselective Protonation, Substitution and Addition Reactions at Pseudotetrahedral Rhenium Complexes
Authors: Bock Frank , Fischer Frank , Radacki Krzysztof , Schenk Wolfdieter A. 
Published: December 2009

AbstractThe chiral N,P ligand P(Me)(Ph)[8‐(2‐methylquinolinyl)] (3) was synthesized and separated into its enantiomers via diastereomeric palladium complexes. The reactions of 3 and (RP)‐3 with [CpRe(CO)(NO)(NCMe)]BF4 (7) gave thediastereomeric complexes [CpRe(CO)(NO){P(Me)(Ph)(C10H8N)}]BF4 [8 and (RRe,SP/SRe,SP)‐8], which, upon borohydride reduction, yielded the corresponding methyl complexes [CpRe(NO){P(Me)(Ph)(C10H8N)}(CH3)] [9 and (RRe,SP/SRe,SP)‐9]. Treatment of 9 with HBF4 under carefully controlled conditions gave the diastereomerically pure chelates [CpRe(NO){P(Me)(Ph)(C10H8N)}]BF4 [(RRe,SP/SRe,RP)‐10, (RRe,RP/SRe,SP)‐10 and (RRe,SP)‐10]. The chelate ring was opened with NaSH to produce the hydrosulfido complexes [CpRe(NO){P(Me)(Ph)(C10H8N)}(SH)] [(RRe,SP/SRe,RP)‐11, (RRe,RP/SRe,SP)‐11 and (RRe,SP)‐11]. Each step in this sequence proceeded with retention of configuration at rhenium. Complex 11 underwent acid‐promoted condensation with aldehydes to give thioaldehyde complexes [CpRe(NO){P(Me)(Ph)(C10H8N)}(S=CHR)]BF4 (12a–d, R = Ph, Me, 4‐C6H4OMe, C6F5). The addition of nucleophiles X– to 12a gave rhenium‐coordinated α‐chiral thiolate complexes [CpRe(NO){P(Me)(Ph)(C10H8N)}{SC(H)(Ph)(X)}] (13a–e, X = acac, PhCH2S, EtS, tBuS, CN) with 42–89 % de. The thiolate can readily be cleaved from the rhenium complex by a methylation/chelate ring‐closure strategy. The stereochemistry of the entire reaction sequence was corroborated for each step by X‐ray crystallography.
Versatility of Substituted 1‐Formyl‐9H‐β‐carbolines for the Synthesis of New Fused β‐Carbolines via Intramolecular 1,3‐Dipolar Cycloaddition
Authors: Singh Virender , Hutait Samiran , Biswas Subhasish , Batra Sanjay 
Published: December 2009

AbstractSubstituted 1‐formyl‐9H‐β‐carbolines are demonstrated to be viable precursors for the synthesis of a library of new β‐carboline‐based polycyclic systems via 1,3‐dipolar cycloaddition strategy.
A Phenolic Antioxidant Releasing Nitric Oxide on Demand
Authors: Vittorino Elisa , Sortino Salvatore 
Published: December 2009

AbstractA novel molecular conjugate (1) that combines radical scavenging properties to light‐regulated release of nitric oxide (NO) has been designed and synthesized by a straightforward procedure. This compound integrates a catecholic unit and a suitable NO photodonor, separated by an alkyl spacer, into the same molecular skeleton. The radical scavenging properties of 1 were evaluated by investigating its reactivity toward hydrogen abstraction by tert‐butoxy radical by using laser flash photolysis techniques. The catecholic function of 1 is transparent to visible light, which, in contrast, is exclusively absorbed by the NO photodonor, resulting in the photocontrolled release of this radical species, monitored by an ultrasensitive NO electrode. A comparison of the value of the hydrogen abstraction rate constant and the amount of NO photoreleased with those of reference models demonstrates the retention of the single properties into the new molecular entity. This characteristic together with its water solubility make 1 a potential model system in the perspective of “multitarget” compounds for biomedical research studies.
Recent developments and applications of EMMA in enzymatic and derivatization reactions
Authors: Zhang Jie , Hoogmartens Jos , Van Schepdael Ann 
Published: December 2009

AbstractThis review covers the time period of 2007 until mid‐2009 and describes new developments in the field of electrophoretically mediated microanalysis. The review is subdivided in two parts dealing with (i) enzymatic and (ii) derivatization or chemical reactions. A compilation of the relevant literature is given for each part.
Soil erosion assessment using geomorphological remote sensing techniques: an example from southern Italy
Authors: Lo Curzio Sergio , Magliulo Paolo 
Published: December 2009

AbstractThe aim of this study is to assess of the distribution and map the geomorphological effects of soil erosion at the basin scale identifying newly‐formed erosional landsurfaces (NeFELs), by means of an integration of Landsat ETM 7+ remotely sensed data and field‐surveyed geomorphological data. The study was performed on a 228·6 km2‐wide area, located in southern Italy. The study area was first characterized from a lithological, pedological, land‐use and morpho‐topographic point of view and thematic maps were created. Then, the georeferenced Landsat ETM 7+ satellite imagery was processed using the RSI ENVI 4.0 software. The processing consisted of contrast stretching, principal component analysis (PCA), decorrelation stretching and RGB false colour compositing. A field survey was conducted to characterize the features detected on the imagery. Particular attention was given to the NeFELs, which were located using a global positioning system (GPS). We then delimited the Regions of Interest (ROI) on the Landsat ETM 7+ imagery, i.e. polygons representing the ‘ground‐truth’, discriminating the NeFELs from the other features occurring in the imagery. A simple statistical analysis was conducted on the digital number (DN) values of the pixels enclosed in the ROI of the NeFELs, with the aim to determine the spectral response pattern of such landsurfaces. The NeFELs were then classified in the entire image using a maximum likelihood classification algorithm. The results of the classification process were checked in the field. Finally, a spatial analysis was performed by converting the detected landsurfaces into vectorial format and importing them into the ESRI ArcViewGIS 9.0 software.
Application of these procedures, together with the results of the field survey, highlighted that some ‘objects’ in the classified imagery, even if displaying the same spectral response of NeFELs, were not landsurfaces subject to intense soil erosion, thus confirming the strategic importance of the field‐checking for the automatically produced data. During the production of the map of the NeFELs, which is the final result of the study, these ‘objects’ were eliminated by means of simple, geomorphologically‐coherent intersection procedures in a geographic information system (GIS) environment. The overall surface of the NeFELs had an area of 22·9 km2, which was 10% of the total. The spatial analysis showed that the highest frequency of the NeFELs occurred on both south‐facing and southwest‐facing slopes, cut on clayey‐marly deposits, on which fine‐textured and carbonate‐rich Inceptisols were present and displaying slope angle values ranging from 12° to 20°. The comparison of two satellite imageries of different periods highlighted that the NeFELs were most clearly evident immediately after summer tillage operations and not so evident before them, suggesting that these practices could have played an important role in inducing the erosional processes. Copyright © 2009 John Wiley & Sons, Ltd.
Innovation diffusion: Implications for evaluation
Authors: Ashley Shena R. 
Published: December 2009

AbstractWhether looking at the spread and adoption of an intervention across a community, across multiple units, or within a single unit, an understanding of diffusion theory can help evaluators uncover patterns and impacts that might otherwise be overlooked. The theory alerts evaluators to examine why uptake of an intervention appeared different in different sites, according to the characteristics of the people involved, the social systems involved (for example, neighborhoods, states, or organizations), or the communications channels used. Insights might explain intervention intensity across sites and consequent differential effects. It also yields useful information to assist with subsequent replication of the intervention by practitioners and policymakers. © Wiley Periodicals, Inc., and the American Evaluation Association.
The transfer process: Implications for evaluation
Authors: LaBelle Oliver Monica 
Published: December 2009

AbstractTransfer is a term used in many fields to describe a change process involving movement of knowledge, skills, or policy from one place to another. The central components of transfer invite the evaluator to conceptualize the change process in terms of a starting point, different understandings of what is being transferred, the medium or mechanism, the concomitant agents, the purpose, and the ending point. Technological models of transfer can be contrasted with learning models of transfer. This means that the educational technology of the intervention might be easily transferred, for example, but not the organizational engagement and inquiry process associated with it. Such scenarios are common in fields where capacity varies widely from place to place. It is therefore crucial to surface what was actually implemented, especially if programs have the same name in various sites, but in reality have replicated very different forms of the program. © Wiley Periodicals, Inc., and the American Evaluation Association.
Computational Continuum Biomechanics with Application to Swelling Media and Growth Phenomena
Authors: Ehlers W. , Markert B. , Röhrle O. 
Published: December 2009

AbstractBiological tissues, no matter if soft or hard tissues are concerned, basically consist of a solid matrix saturated by an interstitial fluid, which is composed of a liquid solvent and various dissolved solutes. In case of vascular tissues, the blood system including the arteries, the capillary system and the veins has to be added. Based on the complex geometric and biophysical nature ofbiological systems, a biomechanical description is based on a macroscopic, continuum‐mechanical approach proceeding from homogenised microstructures rather than on a full microscopic investigation.Consequently, the present article provides a continuum‐biomechanical approach for the description of biological tissues. This includes the well‐founded framework of the Theory of Porous Media (TPM), which can be seen as an extension of the classical Theory of Mixtures (TM) towards immiscible materials. Based on this approach, which easily can be extended by electro‐chemical information, swelling tissues like the intervertebral disc and growth phenomena like avascular tumour growth and muscle stimulation as the basis of any motion of biological systems can be described. However, as a result of page limitations, the article excludes the incorporation of the blood system into the present modelling and simulation examples as well as the description of any muscle stimulation (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Universal Model for the Elastic, Inelastic and Active Behaviour of Soft Biological Tissues
Authors: Itskov M. , Ehret A. E. 
Published: December 2009

AbstractIn the present paper, we present a universal model for the elastic, inelastic and active behaviour of soft biological tissues. The model is based on generalised structural tensors representing linear combinations of the identity tensor and classical structural tensors associated with fibre directions. The anisotropic behaviour is controlled by the coefficients of these linear combinations appearing as weight factors. Changing these weight factors allows to model softening as well as active contraction. The framework of this unified approach is presented and specialised for typical soft tissue behaviour. In order to model preconditioning observed in cyclic mechanical loading, thermodynamically consistent evolution equations for these weight factors as internal variables are defined. Further, a formulation for active behaviour based on a functional representation of the weight factors is proposed. Finally, the model is illustrated in application to bladder tissue showing both noticeable preconditioning effects and active contractility (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)