bluuebunny/crossref_metadata_2025_split huggingface dataset:
3‐D analysis of the Plasmodium falciparum Maurer's clefts using different electron tomographic approaches
Authors: Henrich Philipp , Kilian Nicole , Lanzer Michael , Cyrklaff Marek 
Published: June 2009

AbstractThe human malaria parasite Plasmodium falciparum exports a large number of proteins into its host erythrocyte to install functions necessary for parasite survival. Important structural components of the export machinery are membrane profiles of parasite origin, termed Maurer's clefts. These profiles span much of the distance between the parasite and the host cell periphery and are believed to deliver P. falciparum‐encoded proteins to the erythrocyte plasma membrane. Although discovered more than a century ago, Maurer's clefts remain a mysterious organelle with little information available regarding their origin, their morphology or their precise role in protein trafficking. Here, we evaluated different techniques to prepare samples for electron tomography, including whole cell cryo‐preparations, vitreous sections, freeze‐substitution and chemical fixation. Our data show that the different approaches tested all have their merits, revealing different aspects of the complex structure of the Maurer's clefts.
Anatomic evaluation of maxillary sinus septa: Surgery and radiology
Authors: Koymen Ramazan , Gocmen‐Mas Nuket , Karacayli Umit , Ortakoglu Kerim , Ozen Tuncer , Yazici Ayse Canan 
Published: May 2009

AbstractThe anatomical structure of the maxillary sinus is fundamental to maxillofacial surgery. The presence of septa, located at the inner surface of the maxillary sinus, increases the risk of sinus membrane perforation during sinus elevation for dental implant surgery. The aim of this study was to evaluate the anatomy of maxillary sinus septa.Data in this study was obtained from a total of 205 cases. One hundred and seventy‐seven patients were partially edentulous (PE) whereas 28 patients had no teeth. Dental computerized tomography (dental CT) was used in the assessment of 410 sinus segments (205 left and 205 right segments). The prevalence of sinus segments with septa was found to be 145/410. Septa were detected in 91 of the 177 PE cases. There were a total of 26 septa in 18 of the 28 completely edentulous (CE) cases. A total of 165 septa were detected in these segments. The prevalence of septa was 46.4% (26/56) in the CE, and 39.2% (139/354) in the PE segments. Thirty septa were found in the anterior, 110 in the middle and 25 in the posterior region. All detected septa were located mediolateral direction. Their relative position: lateral, middle or medial were also noted. The height measurements of the septa varied amongst the different positions. In view of the fact that septa of various heights and courses can develop in all parts of the maxillary sinus, timely and adequate assessment of the inner aspect of the maxillary sinus is essential to avoid complications during sinus augmentation procedures. Clin. Anat. 22:563–570, 2009. © 2009 Wiley‐Liss, Inc.
Development of a Method for the High‐Throughput Quantification of Cellular Proteins
Authors: Paganetti Paolo , Weiss Andreas , Trapp Monique , Hammerl Ina , Bleckmann Dorothée , Bodner Ruth A. , Coven‐Easter Shanie , Housman David E. , Parker Christian N. 
Published: June 2009

AbstractHunting for huntingtin: We describe a screening assay based on the inducible expression of the mutant huntingtin protein in cells and on its highly sensitive homogenous determination. Rapid, reproducible, and robust protein determination was achieved through the use of two donor–acceptor‐labeled antibodies and time‐resolved FRET. The assay was developed and validated for ultra‐throughput screening of low‐molecular‐weight compounds modulating the expression of the mutant protein.magnified imageThe quantification of cellular proteins is essential for the study of many different biological processes. This study describes an assay for the detection of the intracellular mutant huntingtin, the causative agent of Huntington's disease, with a method that may be generally applicable to other cellular proteins. A small recombinant protein tag that is recognized by a pair of readily available, high‐affinity monoclonal antibodies was designed. This tag was then added to an inducible fragment of the mutant huntingtin protein by genetic engineering. We show that it is possible to use time‐resolved FRET to detect low intracellular levels of huntingtin by a simple lysis and detection procedure. This assay was then adapted into a homogeneous, miniaturized format suitable for screening in 1536‐well plates. The use of time‐resolved FRET also permits the assay to be multiplexed with a standard readout of cell toxicity, thus allowing the identification of conditions causing reduction of protein levels simply due to cytotoxicity. The screening results demonstrated that the assay is able to identify compounds that modulate the levels of huntingtin both positively and negatively and that represent valuable starting points for drug discovery programs.
Small‐Molecule Targeting of the Mitochondrial Compartment with an Endogenously Cleaved Reversible Tag
Authors: Ripcke Jens , Zarse Kim , Ristow Michael , Birringer Marc 
Published: June 2009

AbstractReversible mitochondrial shuttle: A novel concept in mitochondrial pharmacology allows the transport of bioactive compounds into the mitochondrial compartment and their subsequent release. A lipoic acid derivative containing a cleavable (“reversible”) triphenylphosphonium tag is endogenously cleaved by the mitochondrial aldehyde dehydrogenase (ALDH‐2) after mitochondrial accumulation.magnified imageTargeted accumulation of chemically unaltered compounds within the mitochondrial compartment has not yet been achieved. Here we describe a reversible tag that is endogenously cleaved after mitochondrial accumulation has occurred. Specifically, we have reversibly tagged α‐lipoic acid with a triphenylphosphonium moiety that is cleaved by the physiologically contained mitochondrial aldehyde dehydrogenase (ALDH‐2). This reversibly tagged compound activates the lipoic acidsensitive pyruvate dehydrogenase complex, and this results in increased glucose oxidation. We observed a reduction in ROS accumulation after preincubation with the reversibly tagged compound, whereas untagged or irreversibly tagged compounds either had no effect on ROS formation or rather caused increased oxidative stress, respectively. Lastly, the cytotoxicity of the reversibly tagged compound is less than that of the irreversibly tagged compound. Overall, reversible tagging combines decreased tag‐related cytotoxicity with increased bioactivity, and this potentially provides a novel concept in mitochondrial pharmacology.
Borate‐Driven Gatelike Scaffolding Using Mesoporous Materials Functionalised with Saccharides
Authors: Aznar Elena , Coll Carmen , Marcos M. Dolores , Martínez‐Máñez Ramón , Sancenón Félix , Soto Juan , Amorós Pedro , Cano Joan , Ruiz Eliseo 
Published: June 2009

AbstractWe report the development of an MCM‐41 mesoporous support that is functionalised with saccharides at the pore outlets and contains the dye [Ru(bipy)3]2+ in the pores (solid S1; bipy=2,2′‐bipyridyl). For this hybrid system, the inhibition of mass transport of the dye from the pore voids to the bulk solution in the presence of borate is demonstrated in water at neutral pH. The formation of the corresponding boroester derivative is related to the selective reaction of borate with the appended saccharides. This control is selective and only anion borate, among several anions and cations, can act as a molecular tap and inhibit the delivery of the entrapped guest. Additionally, the S1–borate system behaves as pH‐controlled gatelike scaffolding. This pH‐responsive release can be achieved in an acidic pH (due to hydrolysis of the boroester), whereas the system remains closed at neutral pH. Molecular dynamic simulations using force‐field methods have been made to theoretically study the open/close borate‐driven mechanism. A mesoporous silica structure was constructed for this purpose, taking the plane (1−11) of the β‐cristobalite structure as a base on which hexagonal nanopores and anchored saccharide derivatives were included. The final model shows a highly flexible nanopore diameter of approximately 12.5 Å of similar size to the [Ru(bipy)3]2+ complex (ca. 12 Å). However, the anchoring of borate to the appended saccharides results in a remarkable reduction of the pore size (down to ca. 6.4 Å) and a significant constraint in the flexibility and mobility of the saccharides. The theoretical calculations are in agreement with the experimental results and enable visualisation of the functional borate‐driven dye‐delivery‐inhibition outcome.
The Central Atom Size Effect on the Structure of Group 14 Tetratolyls
Authors: Ng Maggie C. C. , Craig Donald J. , Harper Jason B. , van‐Eijck Lambert , Stride John A. 
Published: June 2009

AbstractSize matters! The structure and dynamics of the tetratolyl Group 14 elements, which were probed by using high‐resolution inelastic neutron scattering spectra, show a remarkable dependence on the size of the central atom. The para‐methyl groups at the periphery of the molecules constitute the frontier intermolecular interactions of increasingly larger tetrahedra, which becomes critical at the molecular radius of the Si and Ge analogues (see picture).magnified image
Bifunctional Catalysis by Natural Cinchona Alkaloids: A Mechanism Explained
Authors: Cucinotta Clotilde S. , Kosa Monica , Melchiorre Paolo , Cavalli Andrea , Gervasio Francesco L. 
Published: June 2009

AbstractThe use of bifunctional chiral catalysts, which are able to simultaneously bind and activate two reacting partners, currently represents an efficient and reliable strategy for the stereoselective preparation of valuable chiral compounds. Cinchona alkaloids such as quinine and quinidine, simple organic molecules generously provided by Nature, were the first compounds to be proposed to operate through a cooperative catalysis. To date, a full mechanistic characterization of the dual catalysis mode of cinchona alkaloids has proven a challenging objective, due to the transient, non‐covalent nature of the involved catalyst–substrate interactions. Here, we propose a mechanistic rationale on how natural cinchona alkaloids act as efficient bifunctional catalysts by using a broad range of computational methods, including classical molecular dynamics, a mixed quantum mechanical/molecular mechanics (QM/MM) approach, and correlated ab‐initio calculations. We also unravel the origin of enantio‐ and diastereoselectivity, which is due to a specific network of hydrogen bonds that stabilize the transition state of the rate‐determining step. The results are validated by experimental evidence.
Activity‐based restorative therapies: Concepts and applications in spinal cord injury‐related neurorehabilitation
Authors: Sadowsky Cristina L. , McDonald John W. 
Published: June 2009

AbstractPhysical rehabilitation following spinal cord injury‐related paralysis has traditionally focused on teaching compensatory techniques, thus enabling the individual to achieve day‐to‐day function despite significant neurological deficits. But the concept of an irreparable central nervous system (CNS) is slowly being replaced with evidence related to CNS plasticity, repair, and regeneration, all related to persistently maintaining appropriate levels of neurological activity both below and above the area where the damage occurred. It is now possible to envision functional repair of the nervous system by implementing rehabilitative interventions. Making the transition from “bench to bedside” requires careful analysis of existing basic science evidence, strategic focus of clinical research, and pragmatic implementation of new therapeutic tools. Activity, defined as both function specific motor task and exercise appears to be a necessity for optimization of functional, metabolic, and neurological status in chronic paralysis. Crafting a comprehensive rehabilitative intervention focused on functional improvement through neurological gains seems logical. The terms activity‐based restorative therapies, activity‐based therapies, and activity‐based rehabilitation have been coined in the last 10 years to describe a new fundamental approach to deficits induced by neurological paralysis. The goal of this approach is to achieve activation of the neurological levels located both above and below the injury level using rehabilitation therapies. This article reviews basic and clinical science evidence pertaining to implementation of physical activity and exercise as a therapeutic tool in the management of chronic spinal cord‐related neurological paralysis. © 2009 Wiley‐Liss, Inc. Dev Disabil Res Rev 2009;15:112–116.
Kurzbericht über die 63. Sitzung des Technischen Lenkungsausschusses der EOTA (EOTA Technical Board) am 5. Februar 2009 in Brüssel
Authors: Sterling Andrea 
Published: June 2009

AbstractBis Anfang Februar 2009 erteilten die derzeit insgesamt 45 Zulassungsstellen der EOTA über 1350 europäische technische Zulassungen (European Technical Approvals – ETAs). Mehr als 40 % der gültigen ETAs sind Zulassungen des Deutschen Instituts für Bautechnik (DIBt).Als Grundlage für die Erteilung von ETAs stehen 27 Leitlinien zur Verfügung, die größtenteils in der deutschen Fassung beim DIBt bestellt werden können und alternativ in der englischen Fassung auf der EOTA‐Internetseite verfügbar sind. Zunehmend werden europäische technische Zulassungen ohne Leitlinie gemäß Art. 9 Abs. 2 der Bauproduktenrichtlinie erteilt. Derzeit liegen dafür insgesamt 125 spezielle, in EOTA abgestimmte Beurteilungsgrundlagen vor (60 davon erstellt vom bzw. unter Mitarbeit des DIBt).In den letzten Monaten wurden von den Diensten der Europäischen Kommission zahlreiche der von EOTA beantragten Produktbereiche für die Erteilung von ETAs ohne Leitlinie freigegeben. Derzeit befinden sich in EOTA 140 Beurteilungsgrundlagen in Bearbeitung und/oder Abstimmung, wobei der Entwurf für eine Beurteilungsgrundlage von der EOTA‐Stelle erarbeitet wird, bei der ein ETA‐Antrag für den betreffenden Produktbereich vorliegt. Das DIBt erarbeitet derzeit Entwürfe für 41 Beurteilungsgrundlagen bzw. ist an deren Erarbeitung beteiligt.
Shaking table test on small‐scale retrofitted model of Sefid‐rud concrete buttress dam
Authors: Ghaemmaghami A. R. , Ghaemian M. 
Published: June 2009

AbstractSefid‐rud concrete buttress dam with a height of 106 m was damaged during the devastating 1990 Manjil earthquake. The dam was repaired and strengthened using epoxy grouting of cracks and the installation of post‐tensioned anchors.In a previous study, nonlinear seismic response of the highest monolith with empty reservoir was investigated experimentally through model testing. A geometric‐scaled model of 1:30 was tested on a shaking table to study dynamic cracking of the model. As a result of the similarity between model and prototype cracking pattern, the model was retrofitted according to prototype retrofitting plan after the Manjil earthquake and re‐tested on shaking table to estimate the current safety of the prototype.Experimental test results showed that the post‐tensioning resulted in a significant decrease in dynamic responses in terms of crest displacement and measured strains of the retrofitted model in comparison with its corresponding responses at the first test. No cracking was observed in the retrofitted model when the base motion peak acceleration exceeded a value that was 22% higher than the one caused cracking in the first model. This can be interpreted as the efficiency of prototype post‐tensioning system in evaluating the seismic safety of Sefid‐rud dam. Copyright © 2009 John Wiley & Sons, Ltd.
Temporal variation in soil detachment under different land uses in the Loess Plateau of China
Authors: Zhang Guang‐hui , Tang Ming‐ke , Zhang X. C. 
Published: June 2009

AbstractMeasurements of temporal variations in soil detachability under different land uses are badly needed to develop new algorithms or evaluate the existing ones for temporal adjustment of soil detachability in continuous soil erosion models. Few studies have been conducted in the Loess Plateau to quantify temporal variations in detachment rate of runoff under different land uses. The objectives of this study were to investigate the temporal variations of soil detachment rate under different land uses and to further identify the potential factors causing the change in detachment rate in the Loess Plateau. Undisturbed soil samples were collected in the fields of arable land (millet, soybean, corn, and potato), grassland, shrub land, wasteland, and woodland and tested in a laboratory flume under a constant hydraulic condition. The measurements started in mid‐April and ended in early October, 2006. The results showed that soil detachment rate of each land use fluctuated considerably over time. Distinctive temporal variation in detachment rate was found throughout the summer growing season of measurement in each land use. The maximum detachment rates of different land uses varied from 0·019 to 0·490 kg m–2 s–1 and the minimum detachment rates ranged from 0·004 to 0·092 kg m–2 s–1. Statistical analysis using a paired‐samples t‐test indicated that variations in soil detachment rate differed significantly at the 0·05 level between land uses in most cases. The major factors responsible for the temporal variation of soil detachment were tillage operations (such as planting, ploughing, weeding, harvesting), soil consolidation, and root growth. The influence of tillage operations on soil detachment depended on the degree of soil disturbance caused by the operations. The consolidation of the topsoil over time after tillage was reflected by increases in soil bulk density and soil cohesion. As soil bulk density and cohesion increased, detachment rate decreased. The impact of root density was inconclusive in this study. Further studies are needed to quantify the effects of root density on temporal variations of soil detachment. This work provides useful information for developing temporal adjustments to soil detachment rate in continuous soil erosion models in the Loess Plateau. Copyright © 2009 John Wiley & Sons, Ltd.
Performance bounds on BER of OFDMA with pulse shaping and maximal ratio combining diversity
Authors: Le Khoa N. 
Published: June 2009

AbstractThis letter derives bounds on the bit error rate (BER) of orthogonal frequency division multiple access (OFDMA) systems employing Lth‐order diversity and pulse shaping in Rayleigh fading environments. First, a new probability density function (pdf) of the signal‐to‐interference ratio (SIR) per bit γk in the presence of inter‐carrier interference power PICI and multiple access interference PMAI is derived. The pdf of the sum of square of the multi‐path gain αk is obtained. Second, the BER of OFDMA systems with binary phase shift keying (BPSK) modulation employing maximal ratio combining (MRC) diversity is derived using the SIR pdf. Detailed discussions are given below. Copyright © 2009 John Wiley & Sons, Ltd.
Numerical simulation of free‐surface flow using the level‐set method with global mass correction
Authors: Zhang Yali , Zou Qingping , Greaves Deborah 
Published: June 2009

AbstractA new numerical method that couples the incompressible Navier–Stokes equations with the global mass correction level‐set method for simulating fluid problems with free surfaces and interfaces is presented in this paper. The finite volume method is used to discretize Navier–Stokes equations with the two‐step projection method on a staggered Cartesian grid. The free‐surface flow problem is solved on a fixed grid in which the free surface is captured by the zero level set. Mass conservation is improved significantly by applying a global mass correction scheme, in a novel combination with third‐order essentially non‐oscillatory schemes and a five stage Runge–Kutta method, to accomplish advection and re‐distancing of the level‐set function. The coupled solver is applied to simulate interface change and flow field in four benchmark test cases: (1) shear flow; (2) dam break; (3) travelling and reflection of solitary wave and (4) solitary wave over a submerged object. The computational results are in excellent agreement with theoretical predictions, experimental data and previous numerical simulations using a RANS‐VOF method. The simulations reveal some interesting free‐surface phenomena such as the free‐surface vortices, air entrapment and wave deformation over a submerged object. Copyright © 2009 John Wiley & Sons, Ltd.
Application of the observational method in geotechnical safety management
Authors: Moritz Bernd , Schubert Wulf 
Published: June 2009

AbstractThe uncertainties in the ground model and the subsequent design of tunnels call for an observational approach. To enable the safe and economical tunnelling of underground infrastructure projects with shallow overburden, a safety management plan has to be implemented. The successful application of the observational method is based on a comprehensive definition of the expected behaviour by the designer and the verification of the actual conditions by the site geotechnical engineer during construction. Advanced tools and methods for monitoring data evaluation assist in the continuous interpretation of the system behaviour, enable timely detection of deviations and check against the warning and alarm criteria. The paper shows the application of the observational method as defined in Eurocode7 as part of a Safety Management Plan through two case histories from OeBB tunnel projects.
Multiple pathways in the FGF signaling network are frequently deregulated by gene amplification in oral dysplasias
Authors: Tsui Ivy F.L. , Poh Catherine F. , Garnis Cathie , Rosin Miriam P. , Zhang Lewei , Lam Wan L. 
Published: June 2009

AbstractGenetic alteration in oral premalignant lesions (OPLs), the precursors of oral squamous cell carcinomas (OSCCs), may represent key changes in disease initiation and development. We ask if DNA amplification occurs at this early stage of cancer development and which oncogenic pathways are disrupted in OPLs. Here, we evaluated 50 high‐grade dysplasias and low‐grade dysplasias that later progressed to cancer for gene dosage aberrations using tiling‐path DNA microarrays. Early occurrences of DNA amplification and homozygous deletion were frequently detected, with 40% (20/50) of these early lesions exhibiting such features. Expression for 88 genes in 7 recurrent amplicons were evaluated in 5 independent head and neck cancer datasets, with 40 candidates found to be overexpressed relative to normal tissues. These genes were significantly enriched in the canonical ERK/MAPK, FGF, p53, PTEN and PI3K/AKT signaling pathways (p = 8.95 × 10−3 to 3.18 × 10−2). These identified pathways share interactions in one signaling network, and amplification‐mediated deregulation of this network was found in 30.0% of these preinvasive lesions. No such alterations were found in 14 low‐grade dysplasias that did not progress, whereas 43.5% (10/23) of OSCCs were found to have altered genes within the pathways with DNA amplification. Multitarget FISH showed that amplification of EGFR and CCND1 can coexist in single cells of an oral dysplasia, suggesting the dependence on multiple oncogenes for OPL progression. Taken together, these findings identify a critical biological network that is frequently disrupted in high‐risk OPLs, with different specific genes disrupted in different individuals. © 2009 UICC