bluuebunny/crossref_metadata_2025_split huggingface dataset:
Bacterial magnetic particles (BMPs)‐PEI as a novel and efficient non‐viral gene delivery system
Authors: Xiang Li , Bin Wang , Huali Jin , Wei Jiang , Jiesheng Tian , Feng Guan , Ying Li 
Published: July 2007

AbstractBackground Non‐viral methods of gene delivery, especially using polyethylenimine (PEI), have been widely used in gene therapy or DNA vaccination. However, the PEI system has its own drawbacks, which limits its applications.Methods We have developed a novel non‐viral delivery system based on PEI coated on the surface of bacterial magnetic nanoparticles (BMPs). The ability of BMPs‐PEI complexes to bind DNA was determined by retardation of plasmid DNA in agarose gel electrophoresis. The transfection efficiency of BMPs‐PEI/DNA complexes into eukaryotic cells was determined by flow cytometric analysis. The MTT assay was invited to investigate the cytotoxicity of BMPs‐PEI/DNA complexes. The expression efficiency in vivo of BMPs‐PEI bound to the plasmid pCMVβ encoding β‐galactosidase was evaluated intramuscularly inoculated into mice. The immune responses of in vivo delivery of BMPs‐PEI bound plasmid pcD‐VP1 were determined by MTT assay for T cell proliferation and ELISA for detecting total IgG antibodies.Results BMPs‐PEI complexes could bind DNA and provide protection from DNase degradation. The transfection efficiency of BMPs‐PEI/DNA complexes was higher than that in PEI/DNA complexes. Interestingly, in contrast to PEI, the BMPs‐PEI complex was less cytotoxic to cells in vitro. We further demonstrated that the BMPs‐PEI system can deliver an exogenous gene to animals and allow it to be expressed in vivo. Such expression resulted in higher levels of humoral and cellular immune responses against the target antigen compared to controls.Conclusions We have developed a novel BMPs‐PEI gene delivery system with a high transfection efficiency and low toxicity, which presents an attractive strategy for gene therapy and DNA vaccination. Copyright © 2007 John Wiley & Sons, Ltd.
Consistency between chemotyping of single filaments of Planktothrix rubescens (cyanobacteria) by MALDI‐TOF and the peptide patterns of strains determined by HPLC‐MS
Authors: Welker Martin , Erhard Marcel 
Published: July 2007

AbstractThe high metabolic diversity of potentially toxigenic cyanobacteria has been recently demonstrated for several bloom‐forming genera. To understand the dynamics of cyanobacterial blooms and fluctuations in toxin content, techniques are required that allow the distinction of clones in field samples on a subspecific taxonomic level. We evaluated the possibility to analyze single filaments of a common toxigenic taxon, Planktothrix rubescens, by comparing peptide profiles obtained from HPLC/MS analyses of bulk biomass to mass spectra of single filaments for 11 clonal strains. For all strains a significant relationship of chromatogram peak area to mass spectrum peak height was found for individual peptides. Individual peptide's response in mass spectrometry compared to HPLC, however, differed, likely attributable to the presence of particular moieties with high proton affinities in the molecules. Thirty‐four individual peptides detected in HPLC fractions of all strains could also be detected in the corresponding single filaments. In conclusion, MALDI‐TOF MS analysis of single filaments is shown to be an efficient tool for the study of chemotype diversity and dynamics in field studies and laboratory experiments. The good correspondence between peak area and peak height in chromatograms and mass spectra, respectively, is promising with respect to the use of MALDI‐TOF MS as a quantitative analytical tool for natural products studies and cyanotoxin research. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopic and SEM analysis of sodium‐zippeite
Authors: Frost Ray L. , Čejka Jiří , Ayoko Godwin A. , Weier Matt L. 
Published: July 2007

AbstractRaman at 298 and 77 K and infrared spectra of two samples of sodium‐zippeite were studied and interpreted. UO bond lengths in uranyl were calculated and compared with those inferred from the X‐ray single crystal structure data of a synthetic sodium‐zippeite analogue. Hydrogen‐bonding network in the studied samples is discussed. OH…O bond lengths were calculated and compared with those predicted from the X‐ray single crystal structure analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopic analysis of breast cancer tissues: identifying differences between normal, invasive ductal carcinoma and ductal carcinoma in situ of the breast tissue
Authors: Rehman Shazza , Movasaghi Zanyar , Tucker Art T. , Joel Simon P. , Darr Jawwad A. , Ruban Alexander V. , Rehman Ihtesham U. 
Published: July 2007

AbstractA relatively non‐destructive method employing Raman spectroscopy for the analysis of histopathological specimens is described. Raman spectroscopy has allowed qualitative analysis of the same specimen used for histopathological evaluation. Breast cancer tissues have been analysed to demonstrate the feasibility of the chemical changes taking place in the biological tissue, which can be identified precisely, and the results are reproducible.Raman analysis of tissue sections provides distinct spectra that can be used to distinguish between the nuclear grades of ductal carcinoma in situ (DCIS) and invasive ductal carcinoma (IDC) of the breast. Sixty cases of breast carcinoma including DCIS and IDC and seven cases of normal breast tissues were studied employing the Raman spectroscopic technique.This study reports for the first time spectral differences between DCIS grades. It is concluded that Raman spectroscopy can objectively distinguish between DCIS and IDC grades and is non‐destructive and reproducible. It should become possible in future to use Raman spectroscopy as an informative and quantitative method suitable for classification of grades and diagnosis of breast carcinoma. Copyright © 2007 John Wiley & Sons, Ltd.
Raman spectroscopic study of calf thymus DNA: an effect of proton‐ and γ‐irradiation
Authors: Synytsya Alla , Alexa Petr , de Boer Jorrit , Loewe Markus , Moosburger Martin , Würkner Michael , Volka Karel 
Published: July 2007

AbstractRaman spectroscopy was applied to analyse structural changes in calf thymus double‐stranded deoxyribonucleic acid (dsDNA) after proton‐ and γ‐irradiation (0.5, 5 and 50 Gy). Characteristic Raman bands of phosphodiester linkages, nucleic bases and deoxyribose moieties were sensitive to irradiation. A significant damage of the macromolecules was observed only at the highest dose (50 Gy) of both types of radiations. Spectral changes confirmed a radiation‐induced alteration of the native structure of dsDNA. Nucleic bases, especially pyrimidines, were the most sensitive to radiation, while some alterations in the sugar–phosphate backbone were also detected. The differences in the dose‐dependent effects of proton vs γ‐irradiation on studied biomolecule are discussed. Copyright © 2007 John Wiley & Sons, Ltd.
Self‐assembled silver nanoparticle monolayer on glassy carbon: an approach to SERS substrate
Authors: Chen Hongjun , Wang Yuling , Qu Jianying , Dong Shaojun 
Published: July 2007

AbstractIn this paper, the fabrication of an active surface‐enhanced Raman scattering (SERS) substrate by self‐assembled silver nanoparticles on a monolayer of 4‐aminophenyl‐group‐modified glassy carbon (GC) is reported. Silver nanoparticles are attached to the substrate through the electrostatic force between the negatively charged silver nanoparticles and the positively charged 4‐aminophenyl groups on GC. The active SERS substrate has been characterized by means of tapping‐mode atomic force microscopy (AFM), indicating that large quantities of silver nanoparticles are uniformly coated on the substrate. Rhodamine 6G (R6G) and p‐aminothiophenol (p‐ATP) are used as the probe molecules for SERS, resulting in high sensitivity to the SERS response, with the detection limit reaching as low as 10−9 M. This approach is easily controlled and reproducible, and more importantly, can extend the range of usable substrates to carbon‐based materials for SERS with high sensitivity. Copyright © 2007 John Wiley & Sons, Ltd.
Observation of the ν3 Raman band of S3− inserted into sodalite cages
Authors: Ledé B. , Demortier A. , Gobeltz‐Hautecœur N. , Lelieur J.‐P. , Picquenard E. , Duhayon C. 
Published: July 2007

AbstractThe S3− radical anion is observed in several systems: non‐aqueous polysulfides solutions, doped alkali halides, ultramarine pigments (UP) for which S3− is the blue chromophore and S2− is the yellow one and pigments of zeolite 4A structure. The S3− ion has C2V symmetry, and therefore its three vibrational modes should be observed in the Raman and in IR spectra. In resonance Raman spectroscopy, only the symmetric stretching mode ν1 and the bending mode ν2 have been observed, whereas the anti‐symmetric stretching mode ν3 has never been observed whatever the system. In this work, we confirm that ν3 is not observed in solutions with resonance Raman spectroscopy. However, our investigation of several blue UP, with various concentrations of S2−, shows that there is a superposition of two bands at ca 590 cm−1: the first is assigned to ν (S2−) and the second to ν3 (S3−). With the 457.9 nm excitation line, for which the resonance conditions are simultaneously fulfilled for S2− and S3−, the band at ca 590 cm−1 is the sum of the contributions of both ν (S2−) and ν3 (S3−) vibrations, while, with the 647.1 nm line, which only satisfies the resonance conditions of S3−, the band at ca 584 cm−1 must be assigned only to ν3 (S3−). Furthermore, ν3 (S3−) is observed in green UP and in pigments of zeolite structure. The ν3 vibration of S3−, which is observed neither in polysulfide solutions nor in doped alkali halides in resonance Raman conditions, can therefore be observed when this species is inserted into the β‐cages of the sodalite or of the zeolite 4A structures. So, the band at ca 590 cm−1 cannot always be assigned to S2− in these systems. This implies that the concentration of S2− in UP must be reconsidered. Copyright © 2007 John Wiley & Sons, Ltd.
Disruption of the developing female reproductive system by phytoestrogens: Genistein as an example
Authors: Jefferson Wendy N. , Padilla‐Banks Elizabeth , Newbold Retha R. 
Published: July 2007

AbstractStudies in our laboratory have shown that exposure to genistein causes deleterious effects on the developing female reproductive system. Mice treated neonatally on days 1–5 by subcutaneous injection of genistein (0.5–50 mg/kg) exhibited altered ovarian differentiation leading to multioocyte follicles (MOFs) at 2 months of age. Ovarian function and estrous cyclicity were also disrupted by neonatal exposure to genistein with increasing severity observed over time. Reduced fertility was observed in mice treated with genistein (0.5, 5, or 25 mg/kg) and infertility was observed at 50 mg/kg. Mammary gland and behavioral endpoints were also affected by neonatal genistein treatment. Further, transgenerational effects were observed; female offspring obtained from breeding genistein treated females (25 mg/kg) to control males had increased MOFs. Thus, neonatal treatment with genistein at environmentally relevant doses caused adverse consequences on female development which is manifested in adulthood. Whether adverse effects occur in human infants exposed to soy‐based products such as soy infant formulas is unknown but the neonatal murine model may help address some of the current uncertainties since we have shown that many effects obtained from feeding genistin, the glycosolated form of genistein found in soy formula, are similar to those obtained from injecting genistein.
Perinatal exposure to environmental estrogens and the development of obesity
Authors: Newbold Retha R. , Padilla‐Banks Elizabeth , Snyder Ryan J. , Jefferson Wendy N. 
Published: July 2007

AbstractDietary substances and xenobiotic compounds with hormone‐like activity can disrupt the programming of endocrine signaling pathways that are established during perinatal differentiation. The consequences of this disruption may not be apparent until later in life but increasing evidence implicates developmental exposure to environmental hormone‐mimics with a growing list of adverse health effects including reproductive problems and increased cancer risks. Obesity has recently been proposed to be yet another adverse health consequence of exposure to endocrine disrupting substances during development. There is a renewed focus on identifying contributions of environmental factors to the development of obesity since it is reaching worldwide epidemic proportions, and this disease has the potential to overwhelm healthcare systems with associated illnesses such as diabetes and cardiovascular disease. Here, we review the literature that proposes an association of perinatal exposure to endocrine disrupting chemicals, in particular those with estrogenic activity, with the development of obesity later in life. We further describe an animal model of developmental exposure to diethylstilbestrol (DES) to study mechanisms involved in programming for obesity. Our experimental data support the idea that adipocytes and the mechanisms involved in weight homeostasis are novel targets of abnormal programming of environmental estrogens, some of which are found in our foods as naturally occurring substances or inadvertently as contaminants.
A combined state and state estimate feedback solution to the ship positioning control problem
Authors: Grimble M. J. 
Published: July 2007

AbstractA stochastic linear quadratic optimal control problem is considered in which some of the plant states may be measured without a measurement noise component. This set of states are assumed to be associated with the plant inputs and force transducers. The optimal controller is shown to include state feedback from this part of the system. The states which cannot be measured are assumed to be combined in noisy output signal. The optimal controller corresponding to this second subsystem is shown to include a Kalman filter and state‐estimate feedback.The combination of state and state‐estimate feedback has the advantage that the dimension of the Kalman filter is equal to that of the second subsystem mentioned above. In the conventional solution to this problem, no states are assumed measurable, and the dimension of the Kalman filter is equal to the dimension of the complete system. In many industrial control problems, the combined control law enables a significant reduction in the dimension of the filter to be achieved. The technique has been proposed for use in dynamic ship positioning control systems, and this problem is discussed.
The geometry of the barrier in the ‘game of two cars’
Authors: Pachter Meir , Getz Wayne M. 
Published: July 2007

AbstractA complete open barrier surface is constructed in the ‘Game of two cars’ differential game of kind with a circular target set. Our geometric approach has the advantages, among others, that it yields the explicit barrier termination conditions and that it highlights the geometric meaning of the universal and dispersal curves on the barrier.
The game of two elliptical ships
Authors: Miloh T. 
Published: July 2007

AbstractIsaacs' formulation of the game of two cars, which assumes players of circular shape, is extended to include the effect of elongated players and elliptical shapes in particular. The geometry is used to model the problem of ship‐collision avoidance as a differential game which suggests the name of ‘game of two ships’. The game of two ships is formulated as a free‐time unbounded game of kind. A general solution for the optimal controls on the terminal manifold is given and is also used to derive a model analytical solution for the primary optimal path emanating from the target set. The occurrence of singular arcs as well as the condition for switching are also discussed. Finally, a capture criterion for the pursuit‐evasion game between a faster elliptical pursuer and a more manoeuvrable circular evader is also derived. This capture criterion is given in the form of a relationship between the geometrical dimensions of the players, their speed and acceleration ratios, and the maximum range that the manoeuvrable, yet slower, evader can indefinitely guarantee without being captured. If both players have circular shapes, our solution reduces to an already‐known capture criterion for the ‘game of two cars’.
Robust and well‐conditioned eigenstructure assignment via sylvester's equation
Authors: Iii R. K. Cavin , Bhattacharyya S. P. 
Published: July 2007

AbstractAn algorithmic solution is given for the problem of calculating a pole assignment matrix F that makes the eigenvector matrix of A + BF well‐conditioned with respect to inversion, or equivalently, maximally orthonormal. This causes A + BF to have low eigenvalue sensitivity. The algorithm relies on a solution of Sylvester's equation and does not involve co‐ordinate transformations or canonical forms. These results are steps in the direction of transforming pole assignment theory into an effective design tool for control systems.
Optimal non‐linear feedback regulation of spacecraft angular momentum
Authors: Salehi S. V. , Ryan E. P. 
Published: July 2007

AbstractOptimal non‐linear feedback laws are presented for the regulation of spacecraft angular momentum by using flywheels and by using fixed on‐off reaction jets. The control law for the flywheels takes the form of a linear combination of functions of the state, each positively homogeneous of degree 2p‐1 (p1/2); whereas the control law for the reaction jets is of bang‐bang form. The range (of the initial disturbance) over which the flywheels are capable of regulating the system and the problem of momentum dumping are also discussed with regard to flywheel saturation constraints. Finally, a control scheme combining the merits of reaction jets and flywheels is proposed.
Stabilizing optimal control of bilinear systems with a generalized cost
Authors: Tzafestas S. G. , Anagnostou K. E. , Pimenides T. G. 
Published: July 2007

AbstractStabilizing and optimizing feedback control policies are derived for the important class of bilinear systems with generalized quadratric cost functions. These policies as well as the resulting optimal costs are quadratic in the state. The optimal cost function is shown to be a Lyapunov function for the bilinear system at hand. The resulting optimal and stabilized closed‐loop system is of third order with respect to the state. One illustrative example is included.
A decoupling pole placement self‐tuning controller for a class of multivariable processes
Authors: McDermott P. E. , Mellichamp D. A. 
Published: July 2007

AbstractThis paper describes a new multivariable self‐tuning controller that specifically handles different time delays between each of the input‐output pairs (multiple delays), and deals with unknown or varying time delay (variable dead time compensation) without requiring an explicit estimate of each delay. The new algorithm can control unstable and/or non‐minimum phase processes; it eliminates both set‐point and load offsets without having to maintain integral action continuously; it decouples the loops, both dynamically and at steady state. The effective decoupling algorithm not only minimizes significant interactions among the control loops, it permits the use of a very simple design criterion, namely the approximate assignment of the primary closed‐loop poles to prespecified locations. A straightforward autotuning technique locates the closed‐loop poles on‐line so as to optimize the system set‐point step responses. One desirable side‐effect is to account for inexact decoupling.The controller is demonstrated using a simulated paper machine head box having an unusually large amount of (off‐diagonal) interaction, a simulated two‐input, two‐output distillation column with time‐varying parameters (varying gains and time delays), and a highly interacting unstable and non‐minimum phase system on which the autotuning technique is demonstrated. These three processes place stringent requirements on any control method, and two of them have been used extensively in the literature to test various multivariable and/or self‐tuning algorithms. Hence, the success of the new technique indicates that it is a very promising candidate to deal with intransigent processes, i.e. those characterized as unstable, non‐minimum phase, time‐varying (non‐linear), and interacting.
A simplified algorithm for optimization of large‐scale gas networks
Authors: Osiadacz A. J. , Bell D. J. 
Published: July 2007

AbstractA number of sophisticated algorithms exist for the optimization of large‐scale systems. However, from a practical viewpoint one must always balance the cost of such optimization in applications with the saving that results. This paper presents a simplified algorithm for large‐scale gas networks which, although yielding a suboptimal energy saving, is nevertheless simple to apply and demands only moderate back‐up facilities. To illustrate the proposed method an example is chosen in which there are fifty nodes and three compressors.
Real‐time computation of feedback controls for constrained optimal control problems. part 2: A correction method based on multiple shooting
Authors: Pesch Hans Josef 
Published: July 2007

AbstractOn the basis of Part 1 of this paper, a numerical method is developed for the real‐time computation of neighbouring optimal feedback controls for constrained optimal control problems. We use the idea of multiple shooting to develop a numerical method which has the following properties:1. The method is applicable to optimal control problems with constraints (differential equations, boundary conditions, inequality constraints, problems with discontinuities, etc.).2. The control variables and the switching points are computed for the remaining time interval of the process.3. All constraints are checked.4. The method is appropriate for real‐time computations on onboard computers of space vehicles.5. The scheme is robust in that controllable deviations from a precalculated flight path are much larger than deviations typical for perturbations occuring in space vehicles.The re‐entry of a space vehicle is investigated as an example. One problem contains a control variable inequality constraint with a large variety of different switching structures, including problems with a corner. A second problem contains a state variable inequality constraint with one or two boundary points or one boundary arc. The different switching structures depend on the tightness of the constraints.
Robust approximate non‐interacting control design for a class of non‐linear stochastic systems
Authors: Bamani Ali H. , Iskanderani Ahmed I. 
Published: July 2007

AbstractA technique for the approximate decoupling of a class of non‐linear stochastic systems which has parameter variation in the plant is presented. First, nominal decoupling is obtained. Then a sensitivity model representing the plant variation is formulated and incorporated into a performance index. Minimization of this index with respect to the free parameters in the feedback matrix results in a robust feedback controller which can reduce the effect of noise and perturbations on the output. An example demonstrating the feasibility of the approach for practical problems is presented.
Minimum‐time turn trajectories to fly‐to points
Authors: Clements John C. 
Published: July 2007

AbstractThe existence of a (global) optimal control u* is established which ensures the execution of a constant‐altitude, minimum‐time flight trajectory to a specified fly‐to point, given the aircraft maximum performance turn radius and the wind speed W and direction tHw. Fast, accurate numerical procedures based on elementary geometry and the solution of a fixed‐point equation are derived for the calculation of u* and the associated optimal trajectory (x*, y*). An example is given and the application of these results to the real‐time solution of the case where the aircraft roll rate is also incorporated into the flight dynamics is discussed.