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Showing papers by "Ben-Gurion University of the Negev published in 2009"


Journal ArticleDOI
TL;DR: In this article, a new expiratory droplet investigation system (EDIS) was used to conduct the most comprehensive program of study to date, of the dilution corrected droplet size distributions produced during different respiratory activities.

850 citations


Journal ArticleDOI
TL;DR: This review will primarily focus on the recent advances and updates on lipid-based nanoparticles for their projected applications in drug delivery, including a review of current activities in the field of liposomes, and challenging issues of targeting and triggering will be discussed in detail.
Abstract: In recent years, various nanotechnology platforms in the area of medical biology, including both diagnostics and therapy, have gained remarkable attention. Moreover, research and development of engineered multifunctional nanoparticles as pharmaceutical drug carriers have spurred exponential growth in applications to medicine in the last decade. Design principles of these nanoparticles, including nano-emulsions, dendrimers, nano-gold, liposomes, drug-carrier conjugates, antibody-drug complexes, and magnetic nanoparticles, are primarily based on unique assemblies of synthetic, natural, or biological components, including but not limited to synthetic polymers, metal ions, oils, and lipids as their building blocks. However, the potential success of these particles in the clinic relies on consideration of important parameters such as nanoparticle fabrication strategies, their physical properties, drug loading efficiencies, drug release potential, and, most importantly, minimum toxicity of the carrier itself. Among these, lipid-based nanoparticles bear the advantage of being the least toxic for in vivo applications, and significant progress has been made in the area of DNA/RNA and drug delivery using lipid-based nanoassemblies. In this review, we will primarily focus on the recent advances and updates on lipid-based nanoparticles for their projected applications in drug delivery. We begin with a review of current activities in the field of liposomes (the so-called honorary nanoparticles), and challenging issues of targeting and triggering will be discussed in detail. We will further describe nanoparticles derived from a novel class of amphipathic lipids called bolaamphiphiles with unique lipid assembly features that have been recently examined as drug/DNA delivery vehicles. Finally, an overview of an emerging novel class of particles (based on lipid components other than phospholipids), solid lipid nanoparticles and nanostructured lipid carriers will be presented. We conclude with a few examples of clinically successful formulations of currently available lipid-based nanoparticles.

768 citations


Journal ArticleDOI
TL;DR: The size distributions of expiratory droplets expelled during coughing and speaking and the velocities of the expiration air jets of healthy volunteers were measured using the interferometric Mie imaging and particle image velocimetry techniques to avoid air sampling losses.

730 citations


Journal ArticleDOI
TL;DR: The potential usefulness and the challenges in modulating the oxidant-antioxidant balance as a potentially promising, but currently disappointing, means of improving insulin action in insulin resistance-associated conditions, leading causes of human morbidity and mortality of the authors' era are explored.
Abstract: Regulated production of reactive oxygen species (ROS)/reactive nitrogen species (RNS) adequately balanced by antioxidant systems is a prerequisite for the participation of these active substances in physiological processes, including insulin action. Yet, increasing evidence implicates ROS and RNS as negative regulators of insulin signaling, rendering them putative mediators in the development of insulin resistance, a common endocrine abnormality that accompanies obesity and is a risk factor of type 2 diabetes. This review deals with this dual, seemingly contradictory, function of ROS and RNS in regulating insulin action: the major processes for ROS and RNS generation and detoxification are presented, and a critical review of the evidence that they participate in the positive and negative regulation of insulin action is provided. The cellular and molecular mechanisms by which ROS and RNS are thought to participate in normal insulin action and in the induction of insulin resistance are then described. Finally, we explore the potential usefulness and the challenges in modulating the oxidant-antioxidant balance as a potentially promising, but currently disappointing, means of improving insulin action in insulin resistance-associated conditions, leading causes of human morbidity and mortality of our era.

511 citations


Journal ArticleDOI
TL;DR: The controversies surrounding the causes, screening, diagnosis, management, and prevention of gestational diabetes mellitus are reported, and specific recommendations for research studies to address the major issues of this medical condition are given.

505 citations


Journal ArticleDOI
TL;DR: It is suggested that the mechanism of release may involve formation and collapse of small gas nuclei in the hydrophobic region of the lipid bilayer during exposure to LFUS, thereby inducing the formation of transient pores through which drugs are released.

430 citations


Journal ArticleDOI
TL;DR: In this paper, the authors describe a climatic analysis of landscape strategies for outdoor cooling in a hot-arid region, considering the efficiency of water use, using different combinations of trees, lawn, and an overhead shade mesh.

406 citations


Journal ArticleDOI
TL;DR: In this paper, the effect of partially laser surface textured piston rings on the fuel consumption and exhaust gas composition of a compression-ignition IC engine was evaluated with a Ford Transit naturally aspirated 2500 cm3 engine at a wide range of engine speeds under near-half load conditions.

379 citations


Journal ArticleDOI
TL;DR: In this article, the political geography of globally expanding urban informalities is analyzed and conceptualized as ''gray spaces'' positioned between the whiteeness of legality/approval/safety, and the greyness of informal spaces.
Abstract: The author analyzes the political geography of globally expanding urban informalities. These are conceptualized as `gray spaces', positioned between the `whiteness' of legality/approval/safety, and...

377 citations


Journal ArticleDOI
TL;DR: In this article, the microstructural changing and corrosion behavior of magnesium alloy AZ31 after extrusion and severe plastic deformation by ECAE process was compared, and the results showed that the severe plastic deformations affected both the microstructure and the corrosion behavior.

370 citations


Journal ArticleDOI
TL;DR: It is shown that the crude and attributable mortality rates associated with carbapenem-resistant K. pneumoniae bacteremia were striking.
Abstract: Objective.To determine the attributable (direct) mortality and morbidity caused by carbapenem-resistant Klebsiella pneumoniae bacteremia.Design.A matched retrospective, historical cohort design, using a stepwise procedure to stringendy match the best control subjects to the best case subjects.Setting.A 1,000-bed tertiary-care university teaching hospital.Patients.Case subjects were defined as adult patients with carbapenem-resistant K. pneumoniae bacteremia during the period from October 2005 through October 2008. Control subjects were defined as patients who were very similar to case subjects except that they did not have bacteremia.Methods.Matching potential control subjects to case subjects was performed at a 1:1 ratio using a computerized record system. The criteria used included same hospitalization period, similar Charlson comorbidity index, same underlying disease, same age within 10 years, and same sex. Demographic and clinical characteristics were collected from medical records.Results.During the study period, 319 patients developed an infection due to carbapenem-resistant K. pneumoniae. Of these 319 patients, 39 (12.2%) developed a bloodstream infection, for an overall rate of 0.59 episodes of carbapenem-resistant K. pneumoniae bacteremia per 10,000 patient-days. We excluded 7 patients from our study, leaving a total of 32 case subjects in our cohort. Case subjects were significandy more likely than control subjects (n = 32) to require care in an intensive care unit (12 case subjects [37.5%] vs 3 control subjects [9.4%]), ventilator support (17 case subjects [53.1%] vs 8 control subjects [25%]), and use of a central venous catheter (19 case subjects [59.4%] vs 9 control subjects [28.1%]). For case subjects, the crude mortality rate was 71.9% (ie, 23 of the 32 case subjects died); for control subjects, the crude mortality rate was 21.9% (ie, 7 of the 32 control subjects died) (P < .001. For case subjects, the attributable mortality was 50% (95% confidence interval [CI], 15.3%-98.6%). A mortality risk ratio of 3.3 (95% CI, 2.9-28.5) was found for case subjects with carbapenem-resistant K. pneumoniae bacteremia.Conclusions.Patients with carbapenem-resistant K. pneumoniae require more intensive and invasive care. We have shown that the crude and attributable mortality rates associated with carbapenem-resistant K. pneumoniae bacteremia were striking.

Journal ArticleDOI
TL;DR: Control fouling experiments with EPS in sodium chloride solutions supplemented with 0.5 mM calcium ions indicate that calcium increases the adsorption efficiency of polysaccharides and DNA by 2- and 3-fold, respectively, which resulted in a significant decrease in permeate water flux.
Abstract: This study elucidates the mechanisms by which extracellular polymeric substances (EPS) impact permeate water flux and salt rejection during biofouling of reverse osmosis (RO) membranes. RO fouling experiments were conducted with Pseudomonas aeruginosa PAO1, EPS extracted from PAO1 biofilms, and dead PAO1 cells fixed in formaldehyde. While a biofouling layer of dead bacterial cells decreases salt rejection and permeate flux by a biofilm-enhanced osmotic pressure mechanism, the EPS biofouling layer adversely impacts permeate flux by increasing the hydraulic resistance to permeate flow. During controlled fouling experiments with extracted EPS in a simulated wastewater solution, polysaccharides adsorbed on the RO membranes much more effectively than proteins (adsorption efficiencies of 61.2-88.7% and 11.6-12.4% for polysaccharides and proteins, respectively). Controlled fouling experiments with EPS in sodium chloride solutions supplemented with 0.5 mM calcium ions (total ionic strength of 15 mM) indicate that calcium increases the adsorption efficiency of polysaccharides and DNA by 2- and 3-fold, respectively. The increased adsorption of EPS onto the membrane resulted in a significant decrease in permeate water flux. Corroborating with these calcium effects, atomic force microscopy (AFM) measurements demonstrated that addition of calcium ions to the feed solution results in a marked increase in the adhesion forces between a carboxylated particle probe and the EPS layer. The increase in the interfacial adhesion forces is attributed to specific EPS-calcium interactions that play a major role in biofouling of RO membranes.

Journal ArticleDOI
TL;DR: It is suggested that even parents' use of conditional positive regard as a socialization practice has adverse emotional and academic consequences, relative to autonomy support.
Abstract: The authors conducted 2 studies of 9th-grade Israeli adolescents (169 in Study 1, 156 in Study 2) to compare the parenting practices of conditional positive regard, conditional negative regard, and autonomy support using data from multiple reporters. Two socialization domains were studied: emotion control and academics. Results were consistent with the self-determination theory model of internaliza- tion, which posits that (a) conditional negative regard predicts feelings of resentment toward parents, which then predict dysregulation of negative emotions and academic disengagement; (b) conditional positive regard predicts feelings of internal compulsion, which then predict suppressive regulation of negative emotions and grade-focused academic engagement; and (c) autonomy support predicts sense of choice, which then predicts integrated regulation of negative emotions and interest-focused academic engagement. These findings suggest that even parents' use of conditional positive regard as a socialization practice has adverse emotional and academic consequences, relative to autonomy support.

Journal ArticleDOI
TL;DR: A proof of concept to an automatic fall detection system for elderly people based on floor vibration and sound sensing, and uses signal processing and pattern recognition algorithm to discriminate between fall events and other events.
Abstract: Falls are a major risk for the elderly people living independently. Rapid detection of fall events can reduce the rate of mortality and raise the chances to survive the event and return to independent living. In the last two decades, several technological solutions for detection of falls were published, but most of them suffer from critical limitations. In this paper, we present a proof of concept to an automatic fall detection system for elderly people. The system is based on floor vibration and sound sensing, and uses signal processing and pattern recognition algorithm to discriminate between fall events and other events. The classification is based on special features like shock response spectrum and mel frequency ceptral coefficients. For the simulation of human falls, we have used a human mimicking doll: ldquoRescue Randy.rdquo The proposed solution is unique, reliable, and does not require the person to wear anything. It is designed to detect fall events in critical cases in which the person is unconscious or in a stress condition. From the preliminary research, the proposed system can detect human mimicking dolls falls with a sensitivity of 97.5% and specificity of 98.6%.

Journal ArticleDOI
TL;DR: A novel data representation scheme for multilevel flash memory cells, in which a set of n cells stores information in the permutation induced by the different charge levels of the individual cells, which eliminates the need for discrete cell levels when programming cells.
Abstract: We explore a novel data representation scheme for multilevel flash memory cells, in which a set of n cells stores information in the permutation induced by the different charge levels of the individual cells. The only allowed charge-placement mechanism is a ldquopush-to-the-toprdquo operation, which takes a single cell of the set and makes it the top-charged cell. The resulting scheme eliminates the need for discrete cell levels, as well as overshoot errors, when programming cells. We present unrestricted Gray codes spanning all possible n-cell states and using only "push-to-the-top" operations, and also construct balanced Gray codes. One important application of the Gray codes is the realization of logic multilevel cells, which is useful in conventional storage solutions. We also investigate rewriting schemes for random data modification. We present both an optimal scheme for the worst case rewrite performance and an approximation scheme for the average-case rewrite performance.

Journal ArticleDOI
TL;DR: These findings suggest that white-matter fibers in ventral occipito-temporal cortex support the integrated function of a distributed cortical network that subserves normal face processing.
Abstract: Prosopagnosics have impaired face recognition, but make relatively normal responses to face stimuli in core brain regions for face recognition. The authors now report that it is the connectivity among these regions that is being disrupted in the disorder. Using diffusion tensor imaging and tractography, we found that a disruption in structural connectivity in ventral occipito-temporal cortex may be the neurobiological basis for the lifelong impairment in face recognition that is experienced by individuals who suffer from congenital prosopagnosia. Our findings suggest that white-matter fibers in ventral occipito-temporal cortex support the integrated function of a distributed cortical network that subserves normal face processing.

Journal ArticleDOI
TL;DR: Evidence is provided that grafting prevascularized cardiac patch into infarct can improve cardiac function after MI and induced thicker scars, prevented further dilatation of the chamber and ventricular dysfunction.
Abstract: The recent progress made in the bioengineering of cardiac patches offers a new therapeutic modality for regenerating the myocardium after myocardial infarction (MI). We present here a strategy for the engineering of a cardiac patch with mature vasculature by heterotopic transplantation onto the omentum. The patch was constructed by seeding neonatal cardiac cells with a mixture of prosurvival and angiogenic factors into an alginate scaffold capable of factor binding and sustained release. After 48 h in culture, the patch was vascularized for 7 days on the omentum, then explanted and transplanted onto infarcted rat hearts, 7 days after MI induction. When evaluated 28 days later, the vascularized cardiac patch showed structural and electrical integration into host myocardium. Moreover, the vascularized patch induced thicker scars, prevented further dilatation of the chamber and ventricular dysfunction. Thus, our study provides evidence that grafting prevascularized cardiac patch into infarct can improve cardiac function after MI.

Journal ArticleDOI
TL;DR: The existence of microorganisms with antimicrobial activity on the coral surface is demonstrated, possibly acting as a first line of defense to protect the coral host against pathogens.

Journal ArticleDOI
TL;DR: Intracoronary injection of alginate biomaterial is feasible, safe, and effective and suggests a new percutaneous intervention to improve infarct repair and prevent adverse remodeling after reperfused MI.

Journal ArticleDOI
TL;DR: A framework for detecting new malicious code in executable files can be designed to achieve very high accuracy while maintaining low false positives (i.e. misclassifying benign files as malicious) and should include training of multiple classifiers on various types of features, as well as an active learning mechanism to maintain high detection accuracy.

Journal ArticleDOI
TL;DR: A modality for the release of drugs from liposomes in vivo using LFUS is presented and the effect of LFUS-induced localized drug release on the therapeutic efficacy was tested on BALB/c mice with C26 colon adenocarcinoma tumors in a footpad.

Journal ArticleDOI
01 Dec 2009-Lithos
TL;DR: In the Central Asian Orogenic Belt (CAOB) as discussed by the authors, voluminous peralkaline and alkaline (alkali-feldspar) granitoids and genetically related bimodal volcanics were emplaced in three stages from Early Permian to late Mesozoic: 295-270 Ma, 230-190 Ma and 150-120 Ma.

Journal ArticleDOI
TL;DR: Experiments 1 and 2 found that values better predict behavioral intentions for distant future situations than near future situations, and Experiment 4 found that the temporal changes in the relationship between values and behavioral intentions depended on how the behavior was construed.

Journal ArticleDOI
TL;DR: The data indicate a transcription-mediated astrocytic transformation early during epileptogenesis, which suggests that the resulting reduction in the clearance of extracellular potassium underlies frequency-dependent neuronal hyperexcitability and network synchronization.
Abstract: Focal epilepsy often develops following traumatic, ischemic, or infectious brain injury. While the electrical activity of the epileptic brain is well characterized, the mechanisms underlying epileptogenesis are poorly understood. We have recently shown that in the rat neocortex, long-lasting breakdown of the blood-brain barrier (BBB) or direct exposure of the neocortex to serum-derived albumin leads to rapid upregulation of the astrocytic marker GFAP (glial fibrillary acidic protein), followed by delayed (within 4-7 d) development of an epileptic focus. We investigated the role of astrocytes in epileptogenesis in the BBB-breakdown and albumin models of epileptogenesis. We found similar, robust changes in astrocytic gene expression in the neocortex within hours following treatment with deoxycholic acid (BBB breakdown) or albumin. These changes predict reduced clearance capacity for both extracellular glutamate and potassium. Electrophysiological recordings in vitro confirmed the reduced clearance of activity-dependent accumulation of both potassium and glutamate 24 h following exposure to albumin. We used a NEURON model to simulate the consequences of reduced astrocytic uptake of potassium and glutamate on EPSPs. The model predicted that the accumulation of glutamate is associated with frequency-dependent (>100 Hz) decreased facilitation of EPSPs, while potassium accumulation leads to frequency-dependent (10-50 Hz) and NMDA-dependent synaptic facilitation. In vitro electrophysiological recordings during epileptogenesis confirmed frequency-dependent synaptic facilitation leading to seizure-like activity. Our data indicate a transcription-mediated astrocytic transformation early during epileptogenesis. We suggest that the resulting reduction in the clearance of extracellular potassium underlies frequency-dependent neuronal hyperexcitability and network synchronization.

Journal ArticleDOI
TL;DR: This paper describes how to mimic a finite domain propagation engine, by mapping propagators into clauses in a SAT solver, and shows that the resulting system solves many finite domain problems significantly faster than other techniques.
Abstract: Finite domain propagation solvers effectively represent the possible values of variables by a set of choices which can be naturally modelled as Boolean variables. In this paper we describe how to mimic a finite domain propagation engine, by mapping propagators into clauses in a SAT solver. This immediately results in strong nogoods for finite domain propagation. But a naive static translation is impractical except in limited cases. We show how to convert propagators to lazy clause generators for a SAT solver. The resulting system introduces flexibility in modelling since variables are modelled dually in the propagation engine and the SAT solver, and we explore various approaches to the dual modelling. We show that the resulting system solves many finite domain problems significantly faster than other techniques.

Journal ArticleDOI
TL;DR: More efficient solar-energy conversion is possible if a single high-energy photon can be made to generate two electron-hole pairs in a cell, rather than a single pair plus heat as discussed by the authors.
Abstract: More efficient solar-energy conversion is possible if a single high-energy photon can be made to generate two electron–hole pairs in a cell, rather than a single pair plus heat. It is now shown that, contrary to expectation, this carrier multiplication is better in bulk semiconductor materials than in quantum dots.

Journal ArticleDOI
TL;DR: It is proposed that primary vascular injury, and specifically BBB breakdown and repair, are key elements in altered interactions within the neurovascular unit and thus may serve as new therapeutic targets.

Journal ArticleDOI
18 Dec 2009-Science
TL;DR: The generation of deuterated carbonic acid in deuterium oxide solution by ultrafast protonation of bicarbonate and its persistence for nanoseconds is reported, which should spur further exploration of acid-base reactivity in carbon dioxide–rich aqueous environments such as those anticipated under sequestration schemes.
Abstract: Despite the widespread importance of aqueous bicarbonate chemistry, its conjugate acid, carbonic acid, has remained uncharacterized in solution. Here we report the generation of deuterated carbonic acid in deuterium oxide solution by ultrafast protonation of bicarbonate and its persistence for nanoseconds. We follow the reaction dynamics upon photoexcitation of a photoacid by monitoring infrared-active marker modes with femtosecond time resolution. By fitting a kinetic model to the experimental data, we directly obtain the on-contact proton-transfer rate to bicarbonate, previously inaccessible with the use of indirect methods. A Marcus free-energy correlation supports an associated pKa (Ka is the acid dissociation constant) of 3.45 +/- 0.15, which is substantially lower than the value of 6.35 that is commonly assumed on the basis of the overall carbon dioxide-to-bicarbonate equilibrium. This result should spur further exploration of acid-base reactivity in carbon dioxide-rich aqueous environments such as those anticipated under sequestration schemes.

Journal ArticleDOI
TL;DR: Competitive competition over external and internal resources and morphogenetic signals may enable some plants to increase their efficiency and external competitive performance by discriminately allocating limited resources to their more promising organs at the expense of failing or less successful organs.
Abstract: Plants are limited in their ability to choose their neighbours, but they are able to orchestrate a wide spectrum of rational competitive behaviours that increase their prospects to prevail under various ecological settings. Through the perception of neighbours, plants are able to anticipate probable competitive interactions and modify their competitive behaviours to maximize their long-term gains. Specifically, plants can minimize competitive encounters by avoiding their neighbours; maximize their competitive effects by aggressively confronting their neighbours; or tolerate the competitive effects of their neighbours. However, the adaptive values of these non-mutually exclusive options are expected to depend strongly on the plants' evolutionary background and to change dynamically according to their past development, and relative sizes and vigour. Additionally, the magnitude of competitive responsiveness is expected to be positively correlated with the reliability of the environmental information regarding the expected competitive interactions and the expected time left for further plastic modifications. Concurrent competition over external and internal resources and morphogenetic signals may enable some plants to increase their efficiency and external competitive performance by discriminately allocating limited resources to their more promising organs at the expense of failing or less successful organs.

Journal ArticleDOI
TL;DR: Application of this novel scaffold may be extended to the combined delivery of additional heparin-binding angiogenic factors or combinations of growth factors active in different tissue regeneration processes.