bluuebunny/crossref_metadata_2025 huggingface dataset:
Cost-Effectiveness Analysis in Comparing Alginate Silver Dressing with Silver Zinc Sulfadiazine Cream in the Treatment of Pressure Ulcers
Authors: Chuangsuwanich Apirag , Chortrakarnkij Peerasak , Kangwanpoom Jupaporn
Published: September 2013

Background The treatment of pressure ulcers is complicated, given the various wound dressing products available. The cost of different treatments varies and the cost-effectiveness of each product has not been thoroughly evaluated. We compare two wound dressing protocols-alginate silver dressing (AlSD) and silver zinc sulfadiazine cream (AgZnSD) with regard to wound healing and cost-effectiveness.

Methods Patients with grade III or IV sacral or trochanteric pressure ulcers were eligible for this prospective, randomized controlled trial. The patients were randomized to receive one of the two dressings for an eight-week period. The criteria of efficacy were based on the Pressure Ulcer Scale for Healing (PUSH) scoring tool. The cost of treatment was also assessed.

Results Twenty patients (12 women and 8 men) were randomly assigned to receive either AlSD (n=10) or AgZnSD cream (n=10). The demographic data and wound characteristics were comparable in the two groups. The two groups showed no significant difference in the reduction of PUSH score, wound size, or volume of exudate. The tissue type score was significantly lower in the AlSD group (3.15±0.68-1.85±0.68 vs. 2.73±0.79-2.2±0.41; P=0.015). The cost of treatment was significantly lower in the AlSD group (377.17 vs. 467.74 USD, respectively; P<0.0001).

Conclusions Alginate silver dressing could be effectively used in the treatment of grade III and IV pressure ulcers. It can improve wound tissue characteristics and is cost-effective.
Reviewer – authors’ best friend
Authors: Vučković-Dekić Ljiljana
Published: September 2013

Peer review is the accepted method for ensuring that the science reported in the biomedical literature is of the highest quality. Reviewers, who are always recruited among the most prominent scientists in the field, are the heart of the peer-review system, and no editor can get along without them. Many authors, especially the younger ones, are unaware of the process so important for the final fate of their scientific work. In this educative article, the principles of the peer review system, the role and the place of the reviewer in the process of publishing, and the professional ethics as well, are explained.
The Biology ofLophelia pertusa(Linnaeus1758) and Other Deep‐Water Reef‐Forming Corals and Impacts from Human Activities.
Authors: Rogers Alex David
Published: September 2013

Over the last twenty years, human exploitation has begun to have an impact in the deep sea, especially in the upper bathyal zone. This has mainly taken the form of deep‐sea fishing but more recently oil exploration has extended beyond the continental shelf. Deep‐water coral reefs occur in the upper bathyal zone throughout the world. These structures, however, are poorly studied with respect to their occurrence, biology and the diversity of the communities associated with them. In the North‐East Atlantic the coralLophelia pertusahas frequently been recorded. The present review examines the current knowledge onL. pertusaand discusses similarities between its biology and that of other deep‐water, reef‐forming, corals. It is concluded thatL. pertusais a reef‐forming coral that has a highly diverse associated fauna. Associated diversity is compared with that of tropical shallow‐water reefs. Such a highly diverse fauna may be shared with other deep‐water, reef‐forming, corals though as yet many of these are poorly studied. The main potential threats toL. pertusain the North‐East Atlantic are considered to be natural phenomena, such as slope failures and changes in ocean circulation and anthropogenic impacts such as deep‐sea fishing and oil exploration. The existing and potential impacts of these activities onL. pertusaare discussed. Deep‐sea fishing is also known to have had a significant impact on deep‐water reefs in other parts of the world.
Revealing the metabolic sites of atazanavir in human by parallel administrations of D‐atazanavir analogs
Authors: Cheng Changfu , Vedananda Sunanda , Wu Lijun , Harbeson Scott , Braman Virginia , Tung Roger
Published: September 2013

Atazanavir (Reyataz®) is an important member of the HIV protease inhibitor class. Because of the complexity of its chemical structure, metabolite identification and structural elucidation face serious challenges. So far, only seven non‐conjugated metabolites in human plasma have been reported, and their structural elucidation is not complete, especially for the major metabolites produced by oxidations. To probe the exact sites of metabolism and to elucidate the relationship among in vivo metabolites of atazanavir, we designed and performed two sets of experiments. The first set of experiments was to determine atazanavir metabolites in human plasma by LC‐MS, from which more than a dozen metabolites were discovered, including seven new ones that have not been reported. The second set involved deuterium labeling on potential metabolic sites to generate D‐atazanavir analogs. D‐atazanavir analogs were dosed to human in parallel with atazanavir. Metabolites of D‐atazanavir were identified by the same LC‐MS method, and the results were compared with those of atazanavir. A metabolite structure can be readily elucidated by comparing the results of the analogs and the pathway by which the metabolite is formed can be proposed with confidence. Experimental results demonstrated that oxidation is the most common metabolic pathway of atazanavir, resulting in the formation of six metabolites of monooxidation (M1, M2, M7, M8, M13, and M14) and four of dioxidation (M15, M16, M17, and M18). The second metabolic pathway is hydrolysis, and the third is N‐dealkylation. Metabolites produced by hydrolysis include M3, M4, and M19. Metabolites formed by N‐dealkylation are M5, M6a, and M6b. Copyright © 2013 John Wiley & Sons, Ltd.
Novel and cost‐effective 6‐plex isobaric tagging reagent, DiART, is effective for identification and relative quantification of complex protein mixtures using PQD fragmentation
Authors: Ramsubramaniam Nikhil , Tao Feng , Li Shuwei , Marten Mark R.
Published: September 2013

Deuterium isobaric Amine Reactive Tag (DiART) reagents facilitate relative quantification during proteomic analysis in a functionally similar manner to commercially available isobaric tag for relative and absolute quantitation (iTRAQ) and tandem mass tag (TMT) reagents. In contrast to iTRAQ and TMT, DiART reagents incorporate deuterium isotopes which significantly reduce the number of required synthesis steps and hence have potential to significantly reduce reagent production cost. We examined the capability of DiART for performing quantitative proteomic experiments using a linear ion‐trap mass spectrometer with Pulsed Q Dissociation (PQD) fragmentation. Using a synthetic peptide tagged with DiART reagent, we observed a precise mass shift of 144.79 Da on the triply charged precursor ion, which shows complete derivatization of the N‐terminus and ε‐amino group of lysine. A DiART tagged tryptic digest of bovine serum albumin showed a sequence coverage of 57.99% which was very comparable to that showed by iTRAQ, 54.77%. Furthermore, a ten protein mixture tagged with DiART reagents and mixed in 1:1:1:1:1:1 exhibited < 15% error, whereas a linear trend (slope of 1.085) was observed when tagged proteins were mixed in the ratio 2:1:2:4:10:14 and plotted against theoretical ratios. Finally, when complex cell‐wall protein mixtures from the model fungus A. nidulans were tagged with DiART reagents and mixed in different ratios, they exhibited similar trends. We conclude that DiART reagents are capable of performing quantitative proteomic experiments using PQD on a linear ion trap mass spectrometer. Copyright © 2013 John Wiley & Sons, Ltd.
Trapping mode dipolar DC collisional activation in the RF‐only ion guide of a linear ion trap/time‐of‐flight instrument for gaseous bio‐ion declustering
Authors: Webb Ian K. , Gao Yang , Londry Frank A. , McLuckey Scott A.
Published: September 2013

The application of dipolar direct current (DDC) to the radio frequency‐only ion guide (Q0) of a hybrid quadrupole/time‐of‐flight mass spectrometer for collision‐induced declustering of large bio‐ions is described. As a broadband technique, ion trap DDC collisional activation (CA) is employed to decluster ions simultaneously over a relatively broad mass‐to‐charge (m/z) range. Declustering DDC CA can yield significantly narrower peaks relative to those observed in the absence of declustering methods, depending upon the extent of noncovalent adduction associated with the ions, and can also be used in conjunction with other methods, such as nozzle–skimmer CA. The key experimental variables in the DDC experiment are the DDC voltage (VDDC), VRF, and the time over which VDDC is applied. The VDDC/VRF ratio is key to the extent to which ion temperatures are elevated and also influences the upper m/z limit for ion storage. The VDDC/VRF ratio affects ion temperatures and the upper m/z limit in opposing directions. That is, as the ratio increases, the ion temperature also increases, whereas the upper m/z storage limit decreases. However, for a given VDDC/VRF ratio, the upper m/z storage limit can be increased by increasing VRF, at the expense of the lower m/z limit for ion storage. The key value of the approach is that it affords a relatively precise degree of control over ion temperatures as well as the time over which they are elevated to a higher temperature. The utility of the method is illustrated by the application of ion trap DDC CA in Q0 to oligonucleotide, protein, and multimeric protein complex analyte ions. Copyright © 2013 John Wiley & Sons, Ltd.
Attenuation of Postmenopausal Bone Loss in Patients with Transient Hypoparathyroidism After Total Thyroidectomy
Authors: Takamura Yuuki , Miyauchi Akira , Yabuta Tomonori , Kihara Minoru , Ito Yasuhiro , Miya Akihiro
Published: September 2013

Background

Increased bone mineral density (BMD) has been reported in patients with postsurgical permanent hypoparathyroidism. Hypoparathyroidism may attenuate the high‐turnover bone loss in postmenopausal women. We reported previously that patients who had transient hypoparathyroidism postoperatively were at subclinical hypoparathyroid (hP) status even 5 years after surgery. We hypothesized that patients with transient hypoparathyroidism (ThP) may have altered BMD.

Methods

A total of 140 women who underwent total thyroidectomy had BMD measurements of the lumbar spine, femoral neck, and radius 3 years after surgery. At surgery, 99 patients were ≥50 years and 41 were <50 years. They were divided into three groups according to their postoperative parathyroid function: There were 80 patients in the no hP (NhP) group, 54 in the ThP group, and 6 in the permanent hP (PhP) group.

Results

Among the 99 patients aged ≥50 years, 36 ThP patients had median Z scores of the BMD in all three areas (lumbar spine, femoral neck, radius) that were significantly higher (by 1.083, 0.533, and 1.047, respectively) than those in the 60 NhP patients aged ≥50 years. The BMDs in the three PhP patients ≥50 years were higher than those in the NhP and ThP patients, but the difference did not reach significance except for in the femoral neck. Multivariate logistic regression analyses showed that Z scores > 0 were significantly associated only with the presence of ThP postoperatively. In the patients <50 years, the BMD values were not significantly different among the three groups except at the radius in PhP patients, which was significantly lower than those of the other patients.

Conclusions

We found that ThP was associated with increased BMD in postmenopausal women. This may be due to attenuation of the high‐turnover bone loss in postmenopausal women.
Specificity in the actions of the UBR1 ubiquitin ligase in the degradation of nuclear receptors
Authors: Sultana Rasheda , Theodoraki Maria A. , Caplan Avrom J.
Published: September 2013

The UBR1 ubiquitin ligase promotes degradation of proteins via the N‐end rule and by another mechanism that detects a misfolded conformation. Although UBR1 was shown recently to act on protein kinases whose misfolding was promoted by inhibition of Hsp90, it was unknown whether this ubiquitin ligase targeted other client types of the chaperone. We analyzed the role of UBR1 in the degradation of nuclear receptors that are classical clients of Hsp90. Our results showed that UBR1 deletion results in impaired degradation of the glucocorticoid receptor and the androgen receptor but not the estrogen receptor α. These findings demonstrate specificity in the actions of the UBR1 ubiquitin ligase in the degradation of Hsp90 clients in the presence of small molecule inhibitors that promote client misfolding.
CANNON–THURSTON MAPS DO NOT ALWAYS EXIST
Authors: BAKER O. , RILEY T. R.
Published: September 2013

We construct a hyperbolic group with a hyperbolic subgroup for which inclusion does not induce a continuous map of the boundaries.
Are ‘Digital Natives’ Equipped to Conquer the Legal Landscape?
Authors: Bates Daniel
Published: September 2013

There is no doubt that the ‘Google Generation’ or ‘Digital Natives’ are entering legal education with a very different set of skills than those who came before them. In this article Daniel Bates examines the precise nature of the skillset of those beginning their legal careers, and considers his experiences teaching research skills to law students at the University of Cambridge for over a decade. Furthermore, he considers how students' educational and cultural background in the areas of research and information literacy should inform the teaching of legal skills.
The Indian Judicial System: Transition from Print to Digital
Authors: Bhardwaj Raj Kumar
Published: September 2013

In this, the third of a trilogy of articles for LIM written by Raj Kumar Bhardwaj, the author addresses the move from print to digital legal information within the Indian judicial system. He describes briefly the historical development of the legal system and the enormous backlog of cases that are pending throughout the court structure, before turning attention to the role of ICT in the legal system and the moves under way to create a more efficient electronic administration for the judiciary in India.
Electrostatic Artificial Cilia
Authors: den Toonder Jaap M. J.
Published: September 2013

In lab‐on‐chip devices, on which complete (bio‐)chemical analysis laboratories are miniaturized and integrated, it is essential to manipulate fluids in sub‐millimetre channels and sub‐microlitre chambers. A special challenge in these small micro‐fluidic systems is to create good mixing flows, since it is almost impossible to generate turbulence. We propose an active micro‐fluidic mixing concept inspired by nature, namely by micro‐organisms that swim through a liquid by oscillating microscopic hairs, cilia, that cover their surface. We have fabricated artificial cilia consisting of electrostatically actuated polymer structures, and have integrated these in a micro‐fluidic channel. Flow visualization experiments show that the cilia can generate substantial fluid velocities, up to 0.6 mm s−1. In addition, very efficient mixing is obtained using specially designed geometrical cilia configurations in a micro‐channel. To explain the effectiveness of the electrostatically actuated cilia, we used a combination of numerical modelling and flow visualization. It was found that, even though the cilia are small, inertial effects do play a role since the cilia motion is extremely fast due to the large electrostatic forces acting on the cilia. Since the artificial cilia can be actively controlled using electrical signals, they have exciting applications in micro‐fluidic devices.
Microwalkers
Authors: Sing Charles E. , Alexander‐Katz Alfredo
Published: September 2013

Microwalkers are a new class of active soft-matter system that walks on surfaces and can transport objects sometimes much larger than the walkers themselves. The origin of such behavior lies at the heart of walking: an increase in the effective friction near the surface. This chapter explores the fundamentals of microwalkers from their assembly to their function, as well as the theoretical foundations used to explain the behavior of single walkers or collections of them. An outlook on what we consider are interesting avenues of research and technological applications for microwalkers, such as cooperative motion and optimal actuation protocols is also included.
Artificial Flagellar Micro‐swimmers
Authors: Dreyfus Rémi , Baudry Jean , Bibette Jérôme
Published: September 2013

In this chapter, we will show how magnetic colloids can be readily self‐assembled into flexible magnetic filament structures. Due to their magnetic and flexible properties, applying external fields can deform these objects. The induced deformations are strongly reminiscent of flagella movements that are encountered in nature. Based on this observation of artificially induced flagella motion, we were able to use these filaments as artificial flagella, which can move in their surrounding viscous fluid and even carry a cargo. These engines were also used to confirm previous predictions made by scientists in the field of fluid mechanics.
Fluid Manipulation by Artificial Cilia
Authors: Hussong J. , Breugem W.‐P. , Westerweel J.
Published: September 2013

In this chapter we report on the fluid manipulation produced by rectangular‐shaped, magnetically‐actuated artificial cilia of 70 µm length and 20 µm width. The synchronized periodic motion of the cilia inside a closed micro‐fluidic chamber leads to an oscillating velocity field that is quantified by means of phase‐locked micro particle image velocimetry (µPIV) measurements. At 10 Hz actuation frequency instantaneous velocities of up to approximately 2 mm s−1 are created during each beat cycle while phase‐averaged velocities are in the order of O(102 µm s−1). Thus, the flow field is dominated by fluid oscillations. The net flow increases linearly with the actuation frequency up to approximately 6 Hz. Beyond 6 Hz it increases exponentially approaching a saturation velocity of maximum fluid transport. This is because the cilia perform a quasi‐static beat cycle at low actuation frequencies which is increasingly damped with rising actuation frequencies by viscous energy dissipation of the fluid. When no back pressure is built up the system achieves maximum volume flow rates of 15.2±0.7 µL min−1 at 20 Hz actuation frequency in a micro‐channel of 0.5 × 5 mm2 cross‐sectional area. This corresponds to a maximum pressure gradient of 6.3±0.3 Pa m−1. The cilia system allows changing the net flow direction by reversing the rotation sense of the magnetic field.
Dopaminergic Treatments for Parkinson’s Disease: Light and Shadows
Authors: Simola Nicola
Published: September 2013

Dopamine‐replacement therapy still stands as the most effective pharmacological strategy for the management of motor impairment associated with Parkinson’s disease. The present chapter aims to provide an overview of the pharmacology of dopamine‐replacement therapy in both preclinical experimental models of Parkinson’s disease and patients, and to present its light and shadows. The effect of dopamine‐replacement therapy on motor impairment, motor complications, non‐motor symptoms, and disease progression will be discussed, with a focus on future therapeutic directions.
D3 Receptor Agonists and Antagonists as Anti‐Parkinsonian Therapeutic Agents
Authors: Johnson Mark , Dutta Aloke
Published: September 2013

Since its discovery, the dopamine D3 receptor has become an important therapeutic target for the development of drugs for neuropsychiatric disorders and Parkinson’s disease. Consequently, an enormous amount of effort has been directed towards development of D3 receptor‐selective molecules. Here we present a comprehensive review on drug development directed towards D3 receptors for the treatment of Parkinson’s disease. D3 receptor‐selective molecules belonging to both agonist and antagonist classes are included. Furthermore, the potential of D3 receptors as neuroprotective targets, as well as their role in the development and treatment of L‐DOPA‐induced dyskinesia, is also covered.
Glutamate Receptor Modulators as Emergent Therapeutic Agents in the Treatment of Parkinson’s Disease
Authors: Célanire Sylvain , Perry Benjamin , Lutjens Robert , Poli Sonia , Reynolds Ian J.
Published: September 2013

Parkinson’s disease (PD) is normally associated with dopamine and other catecholamines because of the profound loss of dopaminergic neurons in the substantia nigra that is the hallmark of the disease. The need for new therapies to treat symptomatic motor and non‐motor symptoms, along with motor complications such as L‐DOPA‐induced dyskinesias (LIDs), remains an important challenge in drug discovery. Significant progress has been made recently in the development of new non‐dopaminergic treatments in the last few years, and there is substantial evidence for altered glutamate neurotransmission in PD, which may be a consequence of dopamine loss. This has generated a great deal of interest in glutamate receptor modulators for the treatment of PD. The interest initially focused on ionotropic glutamate receptors (iGluRs) both for the treatment of the symptoms of PD as well as for neuroprotective effects, and several NMDA and AMPA receptor antagonists have progressed to clinical trials. More recently, there has been substantial progress in the development of metabotropic glutamate receptor (mGluR) modulators. The recent clinical proof‐of‐concept for the treatment of LIDs with mGluR5 negative modulators has demonstrated the potential clinical significance of this approach, and positive modulators or agonists at mGluR4 also look very promising. In this chapter we will review the development and current status of compounds that modulate iGluRs and mGluRs for the treatment of PD and illustrate the challenges and opportunities that these compounds present.
LRRK2 Kinase Inhibitors as New Drugs for Parkinson’s Disease?
Authors: Schulz Sandra , Göring Stefan , Schmidt Boris , Hopf Carsten
Published: September 2013

It is a rare event in drug discovery that mutations in a gene associated with the autosomal dominant forms of a disease, for which there is a large unmet medical need, affect a protein that belongs to a major class of drug targets. As a consequence, in recent years leucine‐rich repeat kinase 2 (LRRK2) has emerged as a major target candidate for therapies of Parkinson’s disease, and selective inhibitors of this kinase are being evaluated as possible new drugs for this detrimental disease. In this chapter, we review recent advances in the design of potent and selective LRRK2 inhibitors as well as the availability of models for their pharmacological evaluation. We also touch upon the challenges ahead – for further improvement of small molecule inhibitors and for in vivo pharmacological target validation.
Phosphodiesterase Inhibitors as a New Therapeutic Approach for the Treatment of Parkinson’s Disease
Authors: Martinez Ana , Gil Carmen
Published: September 2013

Phosphodiesterases (PDEs) are expressed in different brain areas including the striatum. PDEs have recently emerged as important drug targets for central nervous system disorders, including Parkinson’s disease (PD). Levels of cyclic adenosine monophosphate (cAMP) control many cellular signaling pathways and are crucial for the dopamine signal, which is disturbed in PD due to the progressive loss of dopaminergic neurons. PDEs play a key role in cAMP homeostasis, as they are the enzymes responsible for its degradation. Moreover, beyond dopamine neurotransmission, cAMP is involved in many other cellular processes, such as neuroinflammation and neuronal plasticity. This enhances the value of PDEs as promising pharmacological targets for neurological disorders. Furthermore, cAMP‐PDE inhibitors with drug profiles may be used in the near future as disease‐modifying drugs for the treatment of PD. A concise review of the main roles of cAMP‐PDEs expressed in the striatum and the potential of their inhibitors in different animal models of PD is described in this chapter.
Tryptophan Metabolism in Parkinson’s Disease: Future Therapeutic Possibilities
Authors: Majláth Zsófia , Vécsei László
Published: September 2013

Parkinson’s disease is a common, disabling neurodegenerative disorder with characteristic motor and non‐motor symptoms. The exact pathomechanism remains still enigmatic, but some of the main mechanisms contributing to the development of the disease are already recognized. Genetic factors may predispose dopaminergic neurons to selective damage, while mitochondrial disturbances, oxidative stress and neuroinflammatory processes are the key steps leading to final neuronal death. Tryptophan metabolism has been the focus of research interest in recent years after it became evident that alterations in the kynurenine pathway are deeply involved in the pathogenesis of neurodegenerative disorders. The kynurenine pathway may be a valuable target for developing novel neuroprotective therapies in the future.
Carotid Body Transplants as a Therapy for Parkinson’s Disease
Authors: Villadiego Javier , Belén Muñoz‐Manchado Ana , Mendez‐Ferrer Simón , José Toledo‐Aral Juan , López‐Barneo José
Published: September 2013

Intrastriatal grafts of CB cells can produce important recovery in different preclinical models of Parkinson’s disease (PD). The carotid body (CB) is a bilateral neural crest‐derived chemoreceptor organ that is composed of a cluster of highly dopaminergic glomus cells. Although anti‐Parkinsonian CB cell therapy was originally thought to be a dopamine‐replacement approach, different studies have demonstrated that the beneficial action exerted by the CB implant is mainly due to a trophic action on the nigrostriatal pathway rather than to the mere release of dopamine. Accordingly, it has been shown that CB implants produce high levels of glial cell line neurotrophic factor (GDNF). In addition, the trophic action induced by the graft shows a dose‐dependent relation with respect to the size and GDNF expression of the implant. Thus, dopaminergic CB glomus cells appear to be ideally suited for the endogenous release of GDNF, and probably other trophic factors, in PD. In parallel with the preclinical studies, two Phase I/II clinical trials have shown that CB autotransplantation can improve motor symptoms in PD patients although with less efficiency than in experimental models. In this chapter, we review the different preclinical and clinical studies performed on CB transplantation in PD, paying special attention to the mechanisms underlying the grafts’ actions.
Stem‐Cell‐Based Cell‐Replacement Therapy in Parkinson’s Disease
Authors: Tønnesen Jan , Kokaia Merab
Published: September 2013

Stem cells derived from various tissues are emerging as an ethically less controversial and technically more controllable alternative source to fetal primary cells for transplantation in Parkinson’s disease (PD), for replacing degenerating endogenous dopaminergic neurons in the substantia nigra. There is a reasonable hope that stem cell transplantation can become a clinically relevant alternative treatment strategy not only for PD but also for other neurodegenerative diseases. However, our knowledge on how transplanted stem‐cell‐derived dopaminergic neurons integrate into the host tissue is relatively limited. In this chapter we discuss various aspects of stem cell therapy that need to be explored in depth to be able to understand the mechanisms of their therapeutic action. In particular, to what extent grafted stem cells need to attain neuronal properties, and synaptically integrate into the host neuronal circuitry to achieve functional recovery of the Parkinsonian brain.
Ni-Catalyzed [8+3] cycloaddition of tropones with 1,1-cyclopropanediesters
Authors: Tejero Rubén , Ponce Alberto , Adrio Javier , Carretero Juan C.
Published: September 2013

Synthesis of cycloheptapyrane derivatives was accomplished via Ni(ClO4)2·6H2O catalyzed [8+3] cycloaddition of tropone with donor–acceptor cyclopropanes. The enantioselective variant of the process was achieved using either an enantiopure substituted cyclopropane or the combination of a racemic cyclopropane and a suitable chiral Lewis acid.
k-Leibniz algebras from lower order ones: From Lie triple to Lie ℓ-ple systems
Authors: de Azcárraga J. A. , Izquierdo J. M.
Published: September 2013

Two types of higher order Lie ℓ-ple systems are introduced in this paper. They are defined by brackets with ℓ > 3 arguments satisfying certain conditions, and generalize the well-known Lie triple systems. One of the generalizations uses a construction that allows us to associate a (2n − 3)-Leibniz algebra \documentclass[12pt]{minimal}\begin{document}$\mathfrak {L}$\end{document}L with a metric n-Leibniz algebra \documentclass[12pt]{minimal}\begin{document}$\tilde{\mathfrak {L}}$\end{document}L̃ by using a 2(n − 1)-linear Kasymov trace form for \documentclass[12pt]{minimal}\begin{document}$\tilde{\mathfrak {L}}$\end{document}L̃. Some specific types of k-Leibniz algebras, relevant in the construction, are introduced as well. Both higher order Lie ℓ-ple generalizations reduce to the standard Lie triple systems for ℓ = 3.
On the mechanism of elasto-inertial turbulence
Authors: Dubief Yves , Terrapon Vincent E. , Soria Julio
Published: September 2013

Elasto-inertial turbulence (EIT) is a new state of turbulence found in inertial flows with polymer additives. The dynamics of turbulence generated and controlled by such additives is investigated from the perspective of the coupling between polymer dynamics and flow structures. Direct numerical simulations of channel flow with Reynolds numbers ranging from 1000 to 6000 (based on the bulk and the channel height) are used to study the formation and dynamics of elastic instabilities and their effects on the flow. The flow topology of EIT is found to differ significantly from Newtonian wall-turbulence. Structures identified by positive (rotational flow topology) and negative (extensional/compressional flow topology) second invariant Qa isosurfaces of the velocity gradient are cylindrical and aligned in the spanwise direction. Polymers are significantly stretched in sheet-like regions that extend in the streamwise direction with a small upward tilt. The Qa cylindrical structures emerge from the sheets of high polymer extension, in a mechanism of energy transfer from the fluctuations of the polymer stress work to the turbulent kinetic energy. At subcritical Reynolds numbers, EIT is observed at modest Weissenberg number (Wi, ratio polymer relaxation time to viscous time scale). For supercritical Reynolds numbers, flows approach EIT at large Wi. EIT provides new insights on the nature of the asymptotic state of polymer drag reduction (maximum drag reduction), and explains the phenomenon of early turbulence, or onset of turbulence at lower Reynolds numbers than for Newtonian flows observed in some polymeric flows.
Spatial filtering nearly eliminates the side-lobes in single- and multi-photon 4pi-type-C super-resolution fluorescence microscopy
Authors: M. Kavya , Regmi Raju , Mondal Partha P.
Published: September 2013

Super-resolution microscopy has tremendously progressed our understanding of cellular biophysics and biochemistry. Specifically, 4pi fluorescence microscopy technique stands out because of its axial super-resolution capability. All types of 4pi-microscopy techniques work well in conjugation with deconvolution techniques to get rid of artifacts due to side-lobes. In this regard, we propose a technique based on spatial filter in a 4pi-type-C confocal setup to get rid of these artifacts. Using a special spatial filter, we have reduced the depth-of-focus. Interference of two similar depth-of-focus beams in a 4π geometry result in substantial reduction of side-lobes. Studies show a reduction of side-lobes by 46% and 76% for single and two photon variant compared to 4pi − type − C confocal system. This is incredible considering the resolving capability of the existing 4pi − type − C confocal microscopy. Moreover, the main lobe is found to be 150 nm for the proposed spatial filtering technique as compared to 690 nm of the state-of-art confocal system. Reconstruction of experimentally obtained 2PE − 4pi data of green fluorescent protein (GFP)-tagged mitocondrial network shows near elimination of artifacts arising out of side-lobes. Proposed technique may find interesting application in fluorescence microscopy, nano-lithography, and cell biology.
Thermal properties measurement of dry bulk materials with a cylindrical three layers device
Authors: Jannot Y. , Degiovanni A.
Published: September 2013

This paper presents a new method dedicated to thermal properties (conductivity and diffusivity) measurement of dry bulk materials including powders. The cylindrical three layers experimental device (brass/bulk material/stainless steel) and the principle of the measurement method based on a crenel thermal excitation are presented. The one-dimensional modeling of the system is used for a sensitivity analysis and to calculate the standard deviation of the estimation error. Experimental measurements are carried out on three bulk materials: glass beads, cork granules, and expanded polystyrene beads. The estimated thermal properties are compared with the values obtained by other measurement methods. Results are in good agreement with theoretical predictions: both thermal conductivity and diffusivity can be estimated with a good accuracy for low density material like cork granules or expanded polystyrene beads since only thermal diffusivity can be estimated for heavier materials like glass beads. It is finally shown that this method like all transient methods is not suited to the thermal characterization of wet bulk materials.
Huygens' principle for the Klein-Gordon equation in the de Sitter spacetime
Authors: Yagdjian Karen
Published: September 2013

In this article we prove that the Klein-Gordon equation in the de Sitter spacetime obeys the Huygens' principle only if the physical mass m of the scalar field and the dimension n ⩾ 2 of the spatial variable are tied by the equation m2 = (n2−1)/4. Moreover, we define the incomplete Huygens' principle, which is the Huygens' principle restricted to the vanishing second initial datum, and then reveals that the massless scalar field in the de Sitter spacetime obeys the incomplete Huygens' principle and does not obey the Huygens' principle, for the dimensions n = 1, 3, only. Thus, in the de Sitter spacetime the existence of two different scalar fields (in fact, with m = 0 and m2 = (n2−1)/4), which obey incomplete Huygens' principle, is equivalent to the condition n = 3, the spatial dimension of the physical world. In fact, Paul Ehrenfest in 1917 addressed the question: “Why has our space just three dimensions?”. For n = 3 these two values of the mass are the endpoints of the so-called in quantum field theory the Higuchi bound. The value m2 = (n2−1)/4 of the physical mass allows us also to obtain complete asymptotic expansion of the solution for the large time.
Design and characterization of a lumped element single-ended superconducting microwave parametric amplifier with on-chip flux bias line
Authors: Mutus J. Y. , White T. C. , Jeffrey E. , Sank D. , Barends R. , Bochmann J. , Chen Yu , Chen Z. , Chiaro B. , Dunsworth A. , Kelly J. , Megrant A. , Neill C. , O'Malley P. J. J. , Roushan P. , Vainsencher A. , Wenner J. , Siddiqi I. , Vijay R. , Cleland A. N. , Martinis John M.
Published: September 2013

We demonstrate a lumped-element Josephson parametric amplifier, using a single-ended design that includes an on-chip, high-bandwidth flux bias line. The amplifier can be pumped into its region of parametric gain through either the input port or through the flux bias line. Broadband amplification is achieved at a tunable frequency ω/2π between 5 and 7 GHz with quantum-limited noise performance, a gain-bandwidth product greater than 500 MHz, and an input saturation power in excess of −120 dBm. The bias line allows fast frequency tuning of the amplifier, with variations of hundreds of MHz over time scales shorter than 10 ns.
Improving the efficiency of silicon solar cells using the novel gas-lift effect texturing approach
Authors: Amouzgar M. , Kahrizi M.
Published: September 2013

Texturing the surface of the silicon-based solar cells significantly increases the light absorption contributing to their overall efficiency. Wet anisotropic etching technique utilizing the novel gas-lift effect (GLE) approach is an effective and low-cost approach for texturing commercial silicon solar cells. Two solar cell devices, one based on the novel GLE texturing approach and the other based on the conventional method, were designed, fabricated, and characterized. A significant improvement (more than 100%) was observed in the efficiency of the solar cell based on the GLE texturing approach. This improvement may be contributed to the significant impact of utilizing the GLE approach on increasing the real surface area (resulting in higher electron-hole pair generation) and increased light absorption (decreased reflectivity). The application of the new GLE texturing approach results in considerable improvements in overall power efficiency of silicon solar cells without any additional increase to the production cost.
Optical designs of reflection and refraction collection optics for a JT-60SA core Thomson scattering system
Authors: Tojo H. , Hatae T. , Hamano T. , Sakuma T. , Itami K.
Published: September 2013

Collection optics for core measurements in a JT-60SA Thomson scattering system were designed. The collection optics will be installed in a limited space and have a wide field of view and wide wavelength range. Two types of the optics are therefore suggested: refraction and reflection types. The reflection system, with a large primary mirror, avoids large chromatic aberrations. Because the size limit of the primary mirror and vignetting due to the secondary mirror affect the total collection throughput, conditions that provide the high throughput are found through an optimization. A refraction system with four lenses forming an Ernostar system is also employed. The use of high-refractive-index glass materials enhances the freedom of the lens curvatures, resulting in suppression of the spherical and coma aberration. Moreover, sufficient throughput can be achieved, even with smaller lenses than that of a previous design given in [H. Tojo, T. Hatae, T. Sakuma, T. Hamano, K. Itami, Y. Aida, S. Suitoh, and D. Fujie, Rev. Sci. Instrum. 81, 10D539 (2010)]. The optical resolutions of the reflection and refraction systems are both sufficient for understanding the spatial structures in plasma. In particular, the spot sizes at the image of the optics are evaluated as \documentclass[12pt]{minimal}\begin{document}${\sim}0.3 \rm \,mm$\end{document}∼0.3 mm and \documentclass[12pt]{minimal}\begin{document}${\sim}0.4 \rm \,mm$\end{document}∼0.4 mm , respectively. The throughput for the two systems, including the pupil size and transmissivity, are also compared. The results show that good measurement accuracy (<10%) even at high electron temperatures (\documentclass[12pt]{minimal}\begin{document}${<}30 \rm \,keV$\end{document}<30 keV ) can be expected in the refraction system.
Application of consolidate enzymatic system of Fusarium and Saccharomyces to enhance the production of ethanol from spent grain
Authors: Agarwal Madhu , Dinker Abhay
Published: September 2013

Brewer’s spent grain is the byproduct of brew industry and can be a low cost feedstock for bioethanol production. It can be converted into ethanol by the process of fermentation. In the present study, Fusarium oxysporum and Saccahromyces cerevisiae were used as source of enzymes for simultaneous saccharification and fermentation of spent grain into ethanol. Experiments were performed to identify the optimized conditions, temperature, ratio of both species in culture media, pH, Stimulating sugar concentration for both single and mixed culture. The enhancement in bioethanol was observed using mixed culture. Ethanol yield of 57% was obtained in bioreactor with mixed culture, which is higher than the amount obtained using single culture of Fusarium (26%) and Saccharomyces (33%) at the same optimum conditions of temperature (30 °C), pH (6), and stimulating sugars concentration (0.3% w/v). Efficient bioethanol production was achieved using the ligno-cellulolytic degrading enzyme machinery of F. oxysporum.
Communication: Kinetics of chemical ordering in Ag-Au and Ag-Ni nanoalloys
Authors: Calvo F. , Fortunelli A. , Negreiros F. , Wales D. J.
Published: September 2013

The energy landscape and kinetics of medium-sized Ag-Au and Ag-Ni nanoalloy particles are explored via a discrete path sampling approach, focusing on rearrangements connecting regions differing in chemical order. The highly miscible Ag27Au28 supports a large number of nearly degenerate icosahedral homotops. The transformation from reverse core-shell to core-shell involves large displacements away from the icosahedron through elementary steps corresponding to surface diffusion and vacancy formation. The immiscible Ag42Ni13 naturally forms an asymmetric core-shell structure, and about 10 eV is required to extrude the nickel core to the surface. The corresponding transformation occurs via a long and smooth sequence of surface displacements. For both systems the rearrangement kinetics exhibit Arrhenius behavior. These results are discussed in the light of experimental observations.
Optimum laser intensity for the production of energetic deuterium ions from laser-cluster interaction
Authors: Bang W. , Dyer G. , Quevedo H. J. , Bernstein A. C. , Gaul E. , Rougk J. , Aymond F. , Donovan M. E. , Ditmire T.
Published: September 2013

We measured, using Petawatt-level pulses, the average ion energy and neutron yield in high-intensity laser interactions with molecular clusters as a function of laser intensity. The interaction volume over which fusion occurred (1–10 mm3) was larger than previous investigations, owing to the high laser power. Possible effects of prepulses were examined by implementing a pair of plasma mirrors. Our results show an optimum laser intensity for the production of energetic deuterium ions both with and without the use of the plasma mirrors. We measured deuterium plasmas with 14 keV average ion energies, which produced 7.2 × 106 and 1.6 × 107 neutrons in a single shot with and without plasma mirrors, respectively. The measured neutron yields qualitatively matched the expected yields calculated using a cylindrical plasma model.
Role of metallic absorption on enhancing the light emitting efficiency by plasmonic gratings
Authors: Gou Yuchun , Xuan Yimin
Published: September 2013

Due to the adoption of the metallic materials in the surface-plasmon-based light emitting diodes (SP-LEDs), strong absorption of the metal can result in the dissipation of the most photons in the form of thermal energy. In order to investigate the role of the metallic absorption in the SP-LEDs, by means of a series of computational examples of our proposed structure, the effects of several features on the absorptivity of the metal and the light extraction efficiency (LEE) of the chips have been analyzed in detail. The results indicate that the chips with combined metallic and dielectric gratings can exhibit relatively the highest LEE, whereas the absorption of the metal in the chips is very strong, and the absorptivity is several times of LEE. It is concluded that to reduce the absorption and keep high light extraction, proper structure in which the odd mode of surface plasmons can be stimulated at the desired wavelength should be used. In addition, the hexagonal gratings show relatively larger light extraction enhancement and stronger absorption than the rectangular ones.
Rare cell isolation and profiling on a hybrid magnetic/size-sorting chip
Authors: Chung Jaehoon , Issadore David , Ullal Adeeti , Lee Kyungheon , Weissleder Ralph , Lee Hakho
Published: September 2013

We present a hybrid magnetic/size-sorting (HMSS) chip for isolation and molecular analyses of circulating tumor cells (CTCs). The chip employs both negative and positive cell selection in order to provide high throughput, unbiased CTC enrichment. Specifically, the system utilizes a self-assembled magnet to generate high magnetic forces and a weir-style structure for cell sorting. The resulting device thus can perform multiple functions, including magnetic depletion, size-selective cell capture, and on-chip molecular staining. With such capacities, the HMSS device allowed one-step CTC isolation and single cell detection from whole blood, tested with spiked cancer cells. The system further facilitated the study of individual CTCs for heterogeneity in molecular marker expression.
Magnetic reconnection process in transient coaxial helicity injection
Authors: Ebrahimi F. , Hooper E. B. , Sovinec C. R. , Raman R.
Published: September 2013

The physics of magnetic reconnection and fast flux closure in transient coaxial helicity injection experiments in NSTX is examined using resistive MHD simulations. These simulations have been performed using the NIMROD code with fixed boundary flux (including NSTX poloidal coil currents) in the NSTX experimental geometry. Simulations show that an X point is formed in the injector region, followed by formation of closed flux surfaces within 0.5 ms after the driven injector voltage and injector current begin to rapidly decrease. As the injector voltage is turned off, the field lines tend to untwist in the toroidal direction and magnetic field compression exerts a radial J × B force and generates a bi-directional radial Etoroidal×Bpoloidal pinch flow to bring oppositely directed field lines closer together to reconnect. At sufficiently low magnetic diffusivity (high Lundquist number), and with a sufficiently narrow injector flux footprint width, the oppositely directed field lines have sufficient time to reconnect (before dissipating), leading to the formation of closed flux surfaces. The reconnection process is shown to have transient Sweet-Parker characteristics.
Dispersion of Single and Multiwalled Nanotubes with Poly(sodium styrene sulfonate) – Effect of pH and Ionic Strength on Dispersion Stability
Authors: Hassam Christopher , Lewis David A.
Published: September 2013

Aqueous dispersions of carbon nanotubes with poly(styrene sulfonate) were investigated over a range of pH and ionic strengths as a means of determining the potential for further application of the polymer as a protective agent for the tubes. The poly(styrene sulfonate) was found to be an effective dispersal agent, capable of reducing the size of the nanotube agglomerates within an aqueous solution and dispersing the tubes in a single-step process.
2,4,6-Trichloroanisole is a potent suppressor of olfactory signal transduction
Authors: Takeuchi Hiroko , Kato Hiroyuki , Kurahashi Takashi
Published: September 2013

Significance

Off-flavor substances generated naturally in foods/beverages deteriorate the quality of products considerably. Generally, it has been thought that off-flavor substances induce unpleasant smells exogenously. Here, however, we show that 2,4,6-trichroloanisole (TCA), known as one of the strongest off-flavors, inhibits ciliary transduction channels. Surprisingly, suppression was caused with 1-aM solution. The TCA effect showed slow kinetics, with an integration time of approximately 1 s, and positively correlated with the partition coefficient at octanol/water boundary (pH 7.4) of derivatives. These results indicate that the channels are inhibited through a partitioning of those substances into the lipid bilayer of plasma membranes. Furthermore, TCA was detected in varieties of foods/beverages surveyed for odor losses and is likely to be related to the reduction of flavor.