bluuebunny/crossref_metadata_2025_split huggingface dataset:
Inhibition of adhesion of Neisseria meningitidis to human epithelial cells by berry juice polyphenolic fractions
Authors: Toivanen Marko , Huttunen Sanna , Lapinjoki Seppo , Tikkanen‐Kaukanen Carina 
Published: November 2010

AbstractThe adhesion of pathogens to host tissues is the requirement for the initiation of the majority of infectious diseases. It was shown recently that the binding of Neisseria meningitidis pili to immobilized human epithelial cells is inhibited by molecular size fractions (10–100 kDa) of berry juices. Additionally, the isolated meningococcal pili bound to polyphenolic fractions of berry juices. The present study investigated the antiadhesive effects of berry juice polyphenolics against living meningococcal bacteria in a human epithelial cell culture model. The ability of bilberry, cranberry, crowberry and lingonberry juice polyphenolic fractions to inhibit the attachment of N. meningitidis bacteria to HEC‐1B human epithelial cells in a cell culture model was examined. The antibacterial effect of the fractions was tested using a microtiter broth microdilution assay. The most effective adhesion inhibition of 75% was achieved with cranberry juice polyphenolic fraction followed by crowberry (63%), bilberry (63%) and lingonberry (57%) juice polyphenolic fractions. Bacterial survival rates after incubation with the fractions varied between 75–100%. The present results suggest berry juice polyphenols as inhibitors of adherence of N. meningitidis. Thus the binding of meningococci to berry juice polyphenols might be protective for the host against the infection. Copyright © 2010 John Wiley & Sons, Ltd.
Mechatronic assistant system for dental drill handling
Authors: Ortiz Simon Jose Luis , Martinez Arturo Minor , Espinoza Daniel Lorias , Romero Velazquez Jose Guadalupe 
Published: November 2010

AbstractBackgroundHolding a dental tool for many hours of work is reflected in fatigue and manual tremor, which causes bad handling of rotatory instruments and consequently injuries within the buccal cavity. At present there exists no system to help the medical dentist in the support and handling of the dental drill. We propose the use of a mechatronic system to help the odontologist in handling the dental drill.MethodsThe mechatronic system consists of an articulated arm with force sensors and actuators that are activated electronically. The mechanism was developed so that the handpiece is held simultaneously by the mechatronic arm and the hand of the dentist. Expert dentists and odontology students were asked to execute tasks to assess positioning accuracy and system resolution. Students performed positioning tasks to evaluate adaptation to the system. The subjects drew the contour of a circle with and without the mechatronic assistant to assess positioning accuracy. Similarly, they made cavities on acrylic typodonts to evaluate resolution and accuracy. Adaptation to the system was evaluated by inserting the drill burr into cavities previously made.ResultsThe mechatronic system provides support and stability while handling the dental drill. The threshold of force required to move the mechanism prevents involuntary movements affecting the quality of work made on cavities. Positioning accuracy was improved by 53% (p < 0.017) using the system. Similarly, resolution of drilling was improved by 76% (p < 0.001).ConclusionWe have developed the first mechatronic system to assist dentists in handling the dental drill. The arm allows the dentist to manipulate the tool with smooth and precise movements during the preparation of dental cavities with the application of force. The mechatronic system minimizes manual tremor due to fatigue and reduces the risk of iatrogenic dental injuries. Copyright © 2010 John Wiley & Sons, Ltd.
Photoelastic stress analysis in blood vessel phantoms: three‐dimensional visualization and saccular aneurysm with bleb
Authors: Matsushima M. , Tercero C. , Ikeda S. , Fukuda T. , Arai F. , Negoro M. , Takahashi I. 
Published: November 2010

AbstractBackgroundThe photoelastic effect is used for stress measurement during endovascular surgery simulation for quantitative evaluation of catheter trajectory in in vitro environments. By extending the capabilities of this sensing technology, its potential for intravascular tools evaluation will increase.MethodsIn this research the error introduced by stress direction on magnitude measurements was studied, then stress measurements were made in the phantom modelling of a saccular aneurysm with bleb. To visualize three‐dimensionally the stress field changes produced by a guide wire in a phantom wall, a scanner and an algorithm relying on maximum likelihood‐expectation maximization are proposed. Three‐dimensional fields at different pressure level were compared with the stress field surrounding the guide wire.ResultsThe maximum error in stress magnitude measurements due to stress direction was 2.52%. Stress local maximum was detected in the bleb phantom before rupture. Three‐dimensional visualization was obtained in vasculature phantom with average errors of 10.73%, 4.55%, 3.18% for inner pressures of 80, 120, 160 mmHg, respectively. Stress measurement in the neighbourhood of the guide wire is equivalent to applying an inner pressure of 120 mmHg.ConclusionsFor the presented polariscope, the weak influence of stress direction in magnitude measurements was confirmed. In vasculature phantoms, the three‐dimensional visualization of stress eliminated birefringence visualization distortion and enabled more comprehensive comparison of stress produced by intravascular tools with stress produced by normal blood pressure. Copyright © 2010 John Wiley & Sons, Ltd.
Stabilization of nonlinear sandwich systems via state feedback—Discrete‐time systems
Authors: Wang Xu , Stoorvogel Anton A. , Saberi Ali , Grip Håvard Fjær , Sannuti Peddapullaiah 
Published: November 2010

AbstractA recent paper (IEEE Trans. Aut. Contr.2010;55(9):2156–2160) considered stabilization of a class of continuous‐time nonlinear sandwich systems via state feedback. This paper is a discrete‐time counterpart of it. The class of nonlinear sandwich systems consists of saturation elements sandwiched between linear systems. We focus first on single‐layer sandwich systems, which consist of a single saturation sandwiched between two linear systems. For such systems, we present necessary and sufficient conditions for semi‐global and global stabilization problems by state feedback, and develop design methodologies to achieve the prescribed stabilization. We extend the results to single‐layer sandwich systems subject to additional actuator saturation. Finally, we discuss further extension to general multi‐layer sandwich systems with an arbitrary number of saturations sandwiched between linear systems, both with and without actuator saturation. The design methodologies can be viewed as extensions of classical low‐gain design methodologies developed during the 1990s in the context of stabilizing linear systems subject to actuator saturation. Copyright © 2010 John Wiley & Sons, Ltd.
Monitoring of an ATP‐Binding Aptamer and its Conformational Changes Using an α‐Hemolysin Nanopore
Authors: Ying Yi‐Lun , Wang Hai‐Yan , Sutherland Todd C. , Long Yi‐Tao 
Published: November 2010

AbstractAn aptamer is a specific oligonucleotide sequence that spontaneously forms a secondary structure capable of selectively binding an analyte. An aptamer’s conformation is the key to specific binding of a target molecule, even in the case of very closely related targets. Nanopores are a sensitive tool for the single‐molecule analysis of DNA, peptides, and proteins transporting through the pore. Herein, a single α‐hemolysin natural nanopore is utilized to sense the conformational changes of an adenosine 5’‐triphosphate (ATP)‐binding aptamer (ABA). The known DNA sequence of the ABA is used as a model to develop real‐time monitoring of molecular conformational changes that occur by binding targets. The native, folded ABA structure has a nanopore unfolding time of 4.17 ms, compared with 0.29 ms for the ABA:ATP complex. A complementary 14‐mer strand, which binds the ABA sequence in the key nucleic acids responsible for folding, forms linear duplex DNA, resulting in a nanopore transit time of 0.50 ms and a higher capture probability than that of the folded ABA oligomer. Competition assays between the ABA:ATP and ABA:reporter complexes are carried out, and the results suggest that the ABA:ATP complex is formed preferentially. The nanopore allows for the detection of an ABA in its folded, ATP‐bound, and linear conformations.
Tracking Stem Cell Differentiation in the Setting of Automated Optogenetic Stimulation
Authors: Stroh Albrecht , Tsai Hsing-Chen , Wang Li-Ping , Zhang Feng , Kressel Jenny , Aravanis Alexander , Santhanam Nandhini , Deisseroth Karl , Konnerth Arthur , Schneider M. Bret 
Published: November 2010

Abstract
Membrane depolarization has been shown to play an important role in the neural differentiation of stem cells and in the survival and function of mature neurons. Here, we introduce a microbial opsin into ESCs and develop optogenetic technology for stem cell engineering applications, with an automated system for noninvasive modulation of ESC differentiation employing fast optogenetic control of ion flux. Mouse ESCs were stably transduced with channelrhodopsin-2 (ChR2)-yellow fluorescent protein and purified by fluorescence activated cell sorting (FACS). Illumination of resulting ChR2-ESCs with pulses of blue light triggered inward currents. These labeled ESCs retained the capability to differentiate into functional mature neurons, assessed by the presence of voltage-gated sodium currents, action potentials, fast excitatory synaptic transmission, and expression of mature neuronal proteins and neuronal morphology. We designed and tested an apparatus for optically stimulating ChR2-ESCs during chronic neuronal differentiation, with high-speed optical switching on a custom robotic stage with environmental chamber for automated stimulation and imaging over days, with tracking for increased expression of neural and neuronal markers. These data point to potential uses of ChR2 technology for chronic and temporally precise noninvasive optical control of ESCs both in vitro and in vivo, ranging from noninvasive control of stem cell differentiation to causal assessment of the specific contribution of transplanted cells to tissue and network function.
Concise Review: Dissecting a Discrepancy in the Literature: Do Mesenchymal Stem Cells Support or Suppress Tumor Growth?
Authors: Klopp Ann H. , Gupta Anshul , Spaeth Erika , Andreeff Michael , Marini Frank 
Published: November 2010

Abstract
The discovery that mesenchymal stem cells (MSCs) are recruited into tumors has led to a great deal of interest over the past decade in the function of MSCs in tumors. To address this, investigators have used a variety of tumor models in which MSCs are added exogenously to determine their impact on tumor development. Interestingly, many studies have reported contradicting results, with some investigators finding that MSCs promote tumor growth and others reporting that MSCs inhibit tumor growth. Many mechanisms have been reported to account for these observations, such as chemokine signaling, modulation of apoptosis, vascular support, and immune modulation. In this review, we analyzed the differences in the methodology of the studies reported and found that the timing of MSC introduction into tumors may be a critical element. Understanding the conditions in which MSCs enhance tumor growth and metastasis is crucial, both to safely develop MSCs as a therapeutic tool and to advance our understanding of the role of tumor stroma in carcinogenesis.
Krüppel-Like Family of Transcription Factor 9, a Differentiation-Associated Transcription Factor, Suppresses Notch1 Signaling and Inhibits Glioblastoma-Initiating Stem Cells
Authors: Ying Mingyao , Sang Yingying , Li Yunqing , Guerrero-Cazares Hugo , Quinones-Hinojosa Alfredo , Vescovi Angelo L. , Eberhart Charles G. , Xia Shuli , Laterra John 
Published: November 2010

Abstract
Tumor-initiating stem cells (alternatively called cancer stem cells, CSCs) are a subpopulation of tumor cells that plays unique roles in tumor propagation, therapeutic resistance, and tumor recurrence. It is becoming increasingly important to understand the molecular signaling that regulates the self-renewal and differentiation of CSCs. Transcription factors are critical for the regulation of normal and neopolastic stem cells. Here, we examined the expression and function of the Krüppel-like family of transcription factors (KLFs) in human glioblastoma (GBM)-derived neurosphere lines and low-passage primary GBM-derived neurospheres that are enriched for tumor-initiating stem cells. We identify KLF9 as a relatively unique differentiation-induced transcription factor in GBM-derived neurospheres. KLF9 is shown to induce neurosphere cell differentiation, inhibit neurosphere formation, and inhibit neurosphere-derived xenograft growth in vivo. We also show that KLF9 regulates GBM neurosphere cells by binding to the Notch1 promoter and suppressing Notch1 expression and downstream signaling. Our results show for the first time that KLF9 has differentiating and tumor-suppressing functions in tumor-initiating stem cells.
Analytically derived fragility relationships for the modern high‐rise buildings in the UAE
Authors: Mwafy Aman 
Published: November 2010

SUMMARYInvestigating and planning for the expected damage that may hit the earthquake‐prone areas in the UAE should be undertaken in order to predict and mitigate earthquake losses. This paper discusses a framework for developing an essential driving engine in loss estimation systems, namely fragility relationships. Six reference structures, varying in height from 10 to 60 storeys, are selected due to the concentrated economic and human assets in this class of buildings. The reference structures are designed according to the building codes and construction practice adopted in this region. Inelastic fibre‐based simulation models are developed for the buildings using a verified analysis platform, which enables monitoring the spread of yielding and cracking during the multi‐step cyclic analysis. The ground motion uncertainty is accounted for using 20 input ground motions conforming to the latest understanding of the seismo‐tectonic characteristics of the UAE. A large number of inelastic pushover and incremental dynamic collapse analyses are deployed for the reference structures to derive the fragility relationships. The study illustrates the significance of assessing the vulnerability of a population of high‐rise buildings under the effect of various seismic scenarios and the need for expanding this study to cover other classes of structures in this region. Copyright © 2010 John Wiley & Sons, Ltd.
Seismic performance evaluation of diagrid system buildings
Authors: Kim Jinkoo , Lee Young‐Ho 
Published: November 2010

SUMMARYIn this study, the seismic performance of typical diagrid structures was investigated. To this end, 36‐storey diagrid structures with various slopes of external braces were designed and their seismic responses were evaluated using nonlinear static and dynamic analyses. A tubular structure and a diagrid structure with buckling‐restrained braces were also designed with the same design loads, and their seismic performances were compared with those of the diagrid structures. According to the analysis results, the diagrid structures showed higher overstrength with smaller ductility compared with the tubular structure. It was also observed that as the slope of braces increased the shear lag effect increased and the lateral strength decreased. Both the strength and ductility of diagrid structures increased significantly when the diagonal members were replaced by buckling‐restrained braces. Copyright © 2010 John Wiley & Sons, Ltd.
Column shortening analysis of tall buildings with lumped construction sequences
Authors: Kim Han‐Soo , Jeong Se‐Hun , Shin Seung‐Hak 
Published: November 2010

SUMMARYAn analysis method with lumped construction sequences for the column shortening of tall buildings is proposed and its efficiency is investigated. The lumped model shows results that are close to the exact model in subsequent shortening as well as total shortening. Different arrangement methods for the lumped model are investigated. The size of the lumping is studied and 1/15 is recommended considering the efficiency of the lumped model. The lumped models can be used efficiently for the three‐dimensional analysis as well as for the plane frame analysis. The proposed method can be used more effectively at the design stage of tall buildings. Copyright © 2010 John Wiley & Sons, Ltd.
Strain gradient effects on flexural strength design of normal‐strength concrete beams
Authors: Ho J. C. M. , Peng J. 
Published: November 2010

SUMMARYIn the flexural strength design of normal‐strength concrete (NSC) beams, the resultant concrete force and its centroid within the compression zone is generally expressed in an equivalent rectangular stress block. The equivalent concrete stress is expressed as , where is the uni‐axial concrete cylinder strength. Currently, the value of α stipulated in various design codes for NSC is taken as 0.85. Nonetheless, in an experimental study conducted earlier by the authors on NSC columns subjected to concentric and eccentric axial loads, it was found that the value of α significantly depends on strain gradient, which generally increases as strain gradient increases until it reaches a maximum value. Therefore, strain gradient is a critical factor and should be considered in the flexural strength design of NSC members. In this paper, a new flexural strength design method that incorporates the effects of strain gradient is developed for NSC beams. An equivalent rectangular concrete stress block, which is strain‐gradient dependent, is proposed and applied to produce a set of equations for the flexural strength design of singly and doubly reinforced NSC beams with various concrete strengths. Lastly, these equations are converted into charts for practical design application. Copyright © 2010 John Wiley & Sons, Ltd.
TOA estimation of UWB backscattering RFID tag with dual pulse modulation for clutter suppression
Authors: Xu Chi , Law Choi L. 
Published: November 2010

AbstractTo realize precise localization for UWB backscattering RFID system, the arrival time of the direct path in the received signal (referred as time of arrival (TOA)) needs to be accurately estimated. The background clutter is one of the major factors that deteriorates the TOA estimation accuracy in backscattering RFID system. To suppress the background clutter while maintain low‐complexity system design, we propose a novel UWB backscattering RFID system with its tag being implemented with dual pulse (DP) modulation. By transforming the mathematical model of received signal into a proper form, we discover the tag's sequence selection criteria which are able to mitigate the background clutter. For the proposed tag coded with dedicated sequences, a two‐stage TOA estimation algorithm able to effectively mitigate clutter is developed. Simulation results show that the proposed RFID system coupled with the algorithm is able to achieve accurate TOA estimation in the environment where the clutter overwhelms the tag response. Copyright © 2010 John Wiley & Sons, Ltd.
Mixing greedy and predictive approaches to improve geographic routing for VANET
Authors: Wu Tin‐Yu , Wang Yan‐Bo , Lee Wei‐Tsong 
Published: November 2010

AbstractIn recent years, thanks to the development and popularization of wireless network technologies, the issue of vehicularad hocnetwork (VANET) has received great attention, and more and more VANET‐related researches have been brought up. Generally speaking, the biggest difference between VANET and traditionalad hocnetwork is the velocity of carriers because in VANET, the velocity of vehicles, the carriers, is much higher than those in traditionalad hoc. Therefore, it would be a great challenge to forward data efficiently in VANETs and many researches proposed have focused on the development of routing protocols. The current proposed routing protocols are all assumed to simulate in a distributed and ideal environment. As for the complex geographic environments, such as urban scenarios, extra amendments must be needed to improve the efficiency of the routing protocols. Thus, the main purpose of this paper is to design a suitable routing protocol for urban scenarios with better performance and adaptability. For this reason, greedy on straight roads and predictive at the intersections (GSPI) routing protocol is proposed to use greedy mode on straight roads and to use predictive mode at the intersections. In greedy mode, we choose the next hop according to the weight value that combines the distances and multi‐rate. In predictive mode, we predict the directions of the vehicles to determine the next hop. The simulation results reveal that our proposed algorithm indeed proves its feasibility. Copyright © 2010 John Wiley & Sons, Ltd.
Opportunistic scheduling for an OFDMA system with multi‐class services
Authors: Kwon Jeong‐Ahn , Lee Jang‐Won 
Published: November 2010

ABSTRACTIn this paper, we study an opportunistic scheduling problem in an OFDMA system, in which sub‐carriers of the system are allocated to each user in each time slot considering the time‐varying channel condition and QoS requirement of each user. We consider two different classes of services that are represented with different types of utility functions. The utility function for a user in one class is defined as a function of its average data rate, which can be applicable to best‐effort services and the utility function for a user in the other class is defined as a function of its instantaneous data rate, which can be applicable to rate‐sensitive services. Those two types of utility functions have been extensively considered in opportunistic scheduling in wireless networks. However, in most of the previous work, they are considered separately in different problems. In this paper, we formulate a stochastic optimization problem that can treat those two types of utility functions in a single problem, which enables us to implement an opportunistic scheduling algorithm that can consider those two classes of services in a single system in a unified way. Through simulations, we first show that our algorithm provides a good approximation to the optimal solution. In addition, we also verify the appropriateness of our utility models. Copyright © 2010 John Wiley & Sons, Ltd.
Interlevel‐correlated orthogonal space–time block codes based on the expanded signal constellation
Authors: Ma Shang‐Chih 
Published: November 2010

ABSTRACTOrthogonal space–time block codes provide full diversity with a very simple decoding scheme. However, they do not provide much coding gain. For a given space–time block code, we combine several component codes in conjunction with set partitioning of the expanded signal constellation according to the coding gain distance (CGD) criterion. By providing proper interlevel coding between adjacent blocks, we can design an orthogonal space–time block code with high rate, large coding gain, and low decoding complexity. The error performance of an example code is compared with some codes in computer simulation. These codes are compared based on the situation of the same transmission rate, space diversity order, and state complexity of decoding trellis. Copyright © 2010 John Wiley & Sons, Ltd.