bluuebunny/crossref_metadata_2025 huggingface dataset:
Modelling diffusion and adsorption of As species in Fe/GAC adsorbent beds
Authors: Sigrist Mirna E. , Beldomenico Horacio R. , Tarifa Enrique E. , Pieck Carlos L. , Vera Carlos R.
Published: April 2011

BACKGROUND: Arsenic decontamination of drinking water by adsorption is a simple and robust operation. When designing packed bed adsorbers for arsenic, the main problems are the slow diffusion kinetics of As in microporous media and the lack of simple equations for predicting the performance of the equipment. Commercial iron‐doped granular activated carbon adsorbents (Fe/GAC) for groundwater arsenic abatement were studied in this work. Basic parameters for arsenate (AsV) adsorption were measured and their performance at larger scale was simulated with an approximate analytical model.

RESULTS: In the 0–300 µgAs L−1 range, the AsV adsorption isotherm on Fe/GAC was found to be approximately linear. Assuming Henry's law for adsorption and homogeneous surface diffusion with constant diffusivity for intrapellet mass transfer, an approximate model for flow and adsorption of arsenate inside packed bed adsorbers was developed, and reduced to an analytic compact solution using the quasi‐lognormal distribution (Q‐LND) approximation. The use of this model with fitted and reported parameters enabled the approximate simulation of industrial adsorbers and home point‐of‐use filters. Results show that industrial adsorbers meet the breakthrough condition with incomplete utilization of the adsorbent unless convenient process configurations are used. In point‐of‐use systems with short residence times intraparticle diffusion would drastically reduce the adsorbent performance.

CONCLUSION: Assuming linear adsorption of AsV over Fe/GAC, an analytical approximate solution for flow and adsorption in packed beds can be obtained. The model seems to represent correctly the main features of industrial and home filters, however, more experimental data is necessary for scale‐up purposes. Copyright © 2011 Society of Chemical Industry
Minimum requirement of donor cells to reduce the glycolipid storage following bone marrow transplantation in a murine model of Fabry disease
Authors: Yokoi Takayuki , Kobayashi Hiroshi , Shimada Yohta , Eto Yoshikatsu , Ishige Nobuyuki , Kitagawa Teruo , Otsu Makoto , Nakauchi Hiromitsu , Ida Hiroyuki , Ohashi Toya
Published: April 2011

Background

Fabry disease (FD) is a lysosomal storage disorders characterized by a deficiency of the lysosomal enzyme, α‐galactosidase A. This results in the accumulation of glycolipids, mainly globotriaosylceramide (GL‐3), in the lysosomes of various organs. Although bone marrow transplantation and hematopoietic stem cell‐based gene therapy can offer the potential of a curative therapeutic outcome for FD, the minimum requirement of donor cells or gene‐corrected cells to reduce GL‐3 levels is not known.

Methods

Lethally‐irradiated FD mice were transplanted intravenously with normal bone marrow cells (Ly5.1 positive) mixed with those of FD mice (Ly5.2 positive) at various ratios to investigate the level of engraftment and enzyme activity necessary to effect a reduction in GL‐3 storage.

Results

Chimerism of whole white blood cells of recipients' peripheral blood remained stable at 8 weeks after transplantation, and chimerism of granulocytes, monocytes, B cells and T cells was equal to that of white blood cells. GL‐3 levels were significantly reduced in the lung and heart of animals with a 30% and 50% chimera, respectively. The extent of reduction in these mice was almost identical to that with 100% chimera.

Conclusions

In FD mice, reconstitution with 100% donor cells is not required to obtain a therapeutic effect following bone marrow transplantation. These results suggest that a 30% gene correction might be sufficient to reverse disease manifestations in FD. Copyright © 2011 John Wiley & Sons, Ltd.
From the Coxeter Graph to the Klein Graph
Authors: Dejter Italo J.
Published: April 2011

We show that the 56‐vertex Klein cubic graph Γ′ can be obtained from the 28‐vertex Coxeter cubic graph Γ by “zipping” adequately the squares of the 24 7‐cycles of Γ endowed with an orientation obtained by considering Γ as a 𝒞‐ultrahomogeneous digraph, where 𝒞 is the collection formed by both the oriented 7‐cycles and the 2‐arcs that tightly fasten those in Γ. In the process, it is seen that Γ′ is a 𝒞′‐ultrahomogeneous (undirected) graph, where 𝒞′ is the collection formed by both the 7‐cycles C7 and the 1‐paths P2 that tightly fasten those C7 in Γ′. This yields an embedding of Γ′ into a 3‐torus T3 which forms the Klein map of Coxeter notation (7, 3)8. The dual graph of Γ′ in T3 is the distance‐regular Klein quartic graph, with corresponding dual map of Coxeter notation (3, 7)8. © 2011 Wiley Periodicals, Inc. J Graph Theory
The Cartesian product of hypergraphs
Authors: Ostermeier Lydia , Hellmuth Marc , Stadler Peter F.
Published: April 2011

We show that every simple, (weakly) connected, possibly directed and infinite, hypergraph has a unique prime factor decomposition with respect to the (weak) Cartesian product, even if it has infinitely many factors. This generalizes previous results for graphs and undirected hypergraphs to directed and infinite hypergraphs. The proof adopts the strategy outlined by Imrich and Žerovnik for the case of graphs and introduces the notion of diagonal‐free grids as a replacement of the chord‐free 4‐cycles that play a crucial role in the case of graphs. This leads to a generalization of relation Δ on the arc set, whose convex hull is shown to coincide with the product relation of the prime factorization. © 2011 Wiley Periodicals, Inc. J Graph Theory
Kempe Equivalence of Edge‐Colorings in Subcubic and Subquartic Graphs
Authors: McDonald Jessica , Mohar Bojan , Scheide Diego
Published: April 2011

It is proved that all 4‐edge‐colorings of a (sub)cubic graph are Kempe equivalent. This resolves a conjecture of the second author. In fact, it is found that the maximum degree Δ = 3 is a threshold for Kempe equivalence of (Δ+1)‐edge‐colorings, as such an equivalence does not hold in general when Δ = 4. One extra color allows a similar result in this latter case; however, namely, when Δ≤4 it is shown that all (Δ+2)‐edge‐colorings are Kempe equivalent. © 2011 Wiley Periodicals, Inc. J Graph Theory
Carbon‐14‐and carbon‐13‐labeled phosphoric acid [2‐4‐(4‐cyanophenyl)‐thiazol‐2‐yl]‐(2,4‐difluorophenyl)‐1‐[1,2,4]triazol‐4‐yl‐methylpropoxymethyl] monoester dilysine salt, a prodrug of ravuconazole
Authors: Ekhato I. Victor , Rinehart J. Kent
Published: April 2011

4‐Bromobenzoic acid [carboxyl‐14C] and 4‐(2‐bromoacetyl) [Ar‐13C6]benzonitrile were transformed into the title compounds containing [ring14C‐thiazol‐4‐yl] and [Ar‐13C6‐benzonitrile]. 14C‐Ravuconazole was prepared in 37% yield and Purity >99%. 13C6‐Ravuconazole was made in 56% overall yield and Purity of >98%. Each labeled compound was converted by additional reaction steps to the corresponding labeled prodrug. Copyright © 2011 John Wiley & Sons, Ltd
[U‐14C]‐ and [13C6]‐1,3‐dibromobenzene; useful precursors with a rare substitution pattern in the synthesis of isotopologs
Authors: Malmquist Jonas
Published: April 2011

A four‐step procedure for the preparation of [U‐14C]‐1,3‐dibromobenzene and [13C6]‐1,3‐dibromobenzene, from the corresponding bromobenzene, has been developed in a 30% yield. The products were isolated in a high specific activity, 2.6 GBq/mmol, and highest possible 13C incorporation. Copyright © 2011 John Wiley & Sons, Ltd.
Showcasing and subjugating minorities and women: Assignment to visible but trivial committees
Authors: Bradley‐Geist Jill C. , Ruscher Janet B.
Published: April 2011

Given social and legal pressures against employment discrimination, organizations often wish to present an impression of valuing diversity. However, an image of diversity is not necessarily indicative of a true commitment to diversity. To study this issue, we obtained data from 161 college students in a managerial in‐basket exercise that assessed the extent to which students showcased racial minorities and women in high‐visibility organizational roles. In addition, we examined the sincerity of visible displays of diversity by assessing whether participants subjugated minorities and women to trivial versus important roles. We found that our primary hypotheses were supported: Participants tended to assign female and Black employees to high‐visibility roles and trivial roles.
Relative sea level changes during the Holocene in the Sisimiut area, south‐western Greenland
Authors: Bennike Ole , Wagner Bernd , Richter Andreas
Published: April 2011

Holocene relative sea level (RSL) changes have been investigated by analysing and dating isolation sequences from five lakes near Sisimiut in south‐western Greenland. The transitions between marine and lacustrine sediments were determined from elemental analyses and analyses of macroscopic plant and animal remains. Radiocarbon dating was used to provide minimum ages for the transitions and to construct a RSL curve. Dating of a shell of the marine bivalve Macoma balthica indicates that deglaciation of the lowlands occurred in the early Holocene, at around 10 900 cal a BP. The RSL curve shows initial rapid regression from the marine limit at around 140 m, implying strong glacio‐isostatic rebound. We suggest that the margin of the Greenland Ice Sheet was located at the shelf break during the Last Glacial Maximum. Frequent remains of the ostracode Sarcypridopsis aculeata, which is a thermophilous brackish water species that is unknown from the extant fauna of Greenland, in one of the basins around 8500 cal a BP may mark the beginning of the Holocene thermal maximum in the region. Copyright © 2011 John Wiley & Sons, Ltd.
The formation and evolution of an isolated submarine valley in the North Channel, Irish Sea: an investigation of Beaufort's Dyke
Authors: Callaway Alexander , Quinn Rory , Brown Craig J. , Service Matthew , Long David , Benetti Sara
Published: April 2011

Beaufort's Dyke is a submarine depression located in the North Channel of the Irish Sea. With a maximum depth of 312 m, the dyke is one of the deepest areas within the European continental shelf. Integration and interpretation of 450 km of sparker seismic data and full‐coverage bathymetric data derived from multi‐beam echo sounder surveys allow for the investigation of the formation processes of Beaufort's Dyke and the evolution of geomorphological features within it. The dyke, formed by composite subglacial processes dominated by subglacial meltwater discharge, is interpreted as a tunnel valley. The regional isolation of Beaufort's Dyke may be explained by the bounding of the North Channel by the bedrock masses of Ireland and Scotland, coupled with the exploitation of structural weakness along a fault plane and presence of halite in the eroded substrate enhancing the erosive potential of the overlying glacier. Beaufort's Dyke has probably been maintained as an open feature by strong rectilinear tidal currents. The morphology of lunate sediment waves and a large parabolic bedform towards the south of the dyke contradict the observed dominant S–N mean hydrodynamic flow recorded within the North Channel, suggesting an alternative hydrodynamic regime either within the dyke or during bedform creation. Copyright © 2011 John Wiley & Sons, Ltd.
A multi‐proxy record of changing environments from ca. 30 000 to 9000 cal. a BP: Onepoto maar palaeolake, Auckland, New Zealand
Authors: Augustinus Paul , D'costa Donna , Deng Yanbin , Hagg Joseph , Shane Phil
Published: April 2011

We present a high‐resolution record of lacustrine sedimentation spanning ca. 30 000 to 9000 cal. a BP from Onepoto maar, northern North Island, New Zealand. The multi‐proxy record of environmental change is constrained by tephrochronology and accelerator mass spectrometric 14C ages and provides evidence for episodes of rapid environmental change during the Last Glacial Coldest Period (LGCP) and Last Glacial–Interglacial Transition (LGIT) from northern New Zealand. The multi‐proxy palaeoenvironmental record from Onepoto indicates that the LGCP was cold, dry and windy in the Auckland region, with vegetation dominated by herb and grass in a beech forest mosaic between ca. 28 500 and 18 000 cal. a BP. The LGCP was accompanied by more frequent fires and influx of clastic sediment indicating increased erosion during the LGCP, with a mid‐LGCP interstadial identified between ca. 25 000 and 23 000 cal. a BP. Rapid climate amelioration at ca. 18 000 cal. a BP was accompanied by increased terrestrial biomass exemplified by the expansion of lowland podocarp forest, especially Dacrydium cupressinum. Increasing biomass production is reversed briefly by LGIT perturbations which are apparent in many of the proxies that span ca. 14 000–10 500 cal. a BP, suggesting generally increased wetness and higher in situ aquatic plant productivity with reduced terrestrial organic matter and terrigenous detrital influx. Furthermore, conditions at that time were probably warmer and frosts rare based on the increasing importance of Ascarina. The subsequent early Holocene is characterised by podocarp conifer forest and moist mild conditions. Postglacial sea‐level rise breached the crater rim and deposited 36 m of estuarine mud after ca. 9000 cal. a BP. Copyright © 2011 John Wiley & Sons, Ltd.
Modern and early Holocene mollusc fauna of the Ounianga lakes (northern Chad): implications for the palaeohydrology of the central Sahara
Authors: Van Bocxlaer Bert , Verschuren Dirk , Schettler Georg , Kröpelin Stefan
Published: April 2011

The fresh and saline lakes of Ounianga Kebir and Serir in northeastern Chad are among the very few permanent aquatic ecosystems currently existing in the hyper‐arid core of the Sahara desert. The confirmed modern fauna of aquatic molluscs at Ounianga comprises three widespread species (Melanoides tuberculata, Biomphalaria pfeifferi and Lymnaea natalensis), of which only the first appears to maintain a thriving population. We recovered seven more species of gastropods, among which one is new to science (Gabbiella ouniangaensis), and one bivalve species from early Holocene outcrops of diatomaceous limestone at Ounianga Serir. All species except one are known to be commonly spread between lake and river systems by birds, and in its entirety this species‐rich fossil mollusc fauna of Ounianga Serir resembles that of other Saharan lake sites known to have been hydrologically isolated during the early Holocene. The impoverished modern mollusc fauna, which lacks even the widespread and opportunistic species Bulinus truncatus, may have become established relatively recently through new colonisation events, following eradication of the early Holocene mollusc fauna during a later episode of high salinity or desiccation. Copyright © 2011 John Wiley & Sons, Ltd.
Dating Palaeolithic sites in southwestern Crete, Greece
Authors: Strasser Thomas F. , Runnels Curtis , Wegmann Karl , Panagopoulou Eleni , Mccoy Floyd , Digregorio Chad , Karkanas Panagiotis , Thompson Nick
Published: April 2011

Discussions of dispersals of early hominins from Africa assume that Southwest Asia and the Arabian Peninsula were the primary passageways for migrations to Eurasia. The Mediterranean is usually viewed as a barrier to early hominin movements because pre‐sapiens hominins were thought to lack the technical means or the cognitive skills to construct boats. The discovery of early Palaeolithic artefacts in an archaeological survey on the Greek island of Crete challenges this view. Here we show that Palaeolithic artefacts in the Plakias region in southwestern Crete are associated with geological contexts that can be dated to the late Middle or early Late Pleistocene. Because Crete has been separated from the mainland throughout the Pleistocene, the presence of Pleistocene age artefacts there suggests that early hominins were able to cross open water. Copyright © 2011 John Wiley & Sons, Ltd.
Traumatic stress is linked to a deficit in associative episodic memory
Authors: Guez Jonathan , Naveh‐Benjamin Moshe , Yankovsky Yan , Cohen Jonathan , Shiber Asher , Shalev Hadar
Published: April 2011

Individuals with posttraumatic stress disorder (PTSD) are haunted by persistent memories of the trauma, but ironically are impaired in memories of daily life. The current set of 4 experiments compared new learning and memory of emotionally neutral content in 2 groups of patients and aged‐ and education‐matched controls: 20 patients diagnosed with chronic posttraumatic stress disorder (C‐PTSD) and 20 patients diagnosed with acute stress disorder (ASD). In all experiments, participants studied a list of stimuli pairs (words or pictures) and were then tested for their memory of the items, or for the association between items in each pair. Results indicated that both types of patients showed associative memory impairment compared to a control group, although their item memory performance was relatively intact. Potential mechanisms underlying such associative memory deficits in posttraumatic patients are discussed.
Recruitment patterns of side population cells during wound healing in rat vocal folds
Authors: Gugatschka Markus , Kojima Tsuyoshi , Ohno Satoshi , Kanemaru Shin‐ichi , Hirano Shigeru
Published: April 2011

Objectives/Hypothesis:

Despite big advances in understanding the mechanisms of wound healing in vocal fold injury, it still remains unclear which are the decisive factors that lead to a complete restoration or to scarring. Among several other factors, stem cells are believed to play an important role in vocal fold restoration. Side population (SP) cells are considered to contain high numbers of stem cells and have gained great interest in the tissue engineering community. The aim of the following study was to investigate the recruitment pattern of SP cells in a rat vocal fold injury model.

Study Design:

Experimental animal study.

Methods:

Unilateral vocal fold scarring was performed in Sprague Dawley rats. Larynges were harvested 1, 3, 5, 7, 14, 21, and 35 days after initial injury and were examined immunohistochemically for the presence of SP cells. This was done in coronal sections of the posterior and anterior macula flava as well as in the midportion of the vocal fold investigating the lamina propria.

Results:

The number of SP cells peaked significantly after 7 days in the midportion of injured vocal folds, with a return to pre‐injury levels after 14 days. No increase was detected throughout the observed time in the contralateral side. The number of SP cells increased slightly but not significantly in both anterior and posterior macula flava.

Conclusions:

Our findings suggest that SP cells may play an important role in early vocal fold wound healing and may serve as a possible therapeutic target.
The frontal intersinus septum takedown procedure
Authors: Reh Douglas D. , Melvin Thuy‐Anh N. , Bolger William E. , Lane Andrew P.
Published: April 2011

Objectives/Hypothesis:

Unilateral frontal sinus obstruction presents a surgical challenge when outflow tract osteoneogenesis or dense scarring is present. Frontal sinus obliteration is often employed as a last resort, but this procedure has potential long‐term complications. In some cases, endoscopic modified Lothrop or unilateral drillout procedures may be effective options; however, restenosis rates are often high. Here we report our experience using frontal intersinus septum takedown (FISST) to address unilateral obstruction while preserving the opposite frontal outflow tract.

Study Design:

A retrospective review was performed of 12 patients with unilateral frontal sinus opacification due to irreversible frontal recess obstruction who underwent FISST. Surgical outcomes were assessed based on symptoms and computed tomography (CT) resolution of frontal sinus disease.

Results:

All 12 patients undergoing FISST had significant improvement in their symptoms. Ten postoperative CT scans were available for review, all showing continued patency of the interfrontal connection, and nine out of 10 with resolution of radiographic frontal sinus disease. Eleven of the procedures were performed via trephination, and one was achieved endoscopically.

Conclusions:

In patients with one obstructed frontal sinus and a functional contralateral sinus, removal of the intersinus septum allows for adequate sinus drainage and significant clinical improvement. The success of FISST may be surprising given knowledge of mucociliary clearance patterns, but may be effective because of the naturally dependent position of the frontal sinus ostium.
Robotic facelift thyroidectomy: I. Preclinical simulation and morphometric assessment
Authors: Singer Michael C. , Seybt Melanie W. , Terris David J.
Published: April 2011

Objectives:

Robotic thyroidectomy was introduced in the United States despite scant preclinical data. We pursued a systematic preclinical investigation of a new remote access, robotic thyroidectomy technique via a facelift incision, and sought to define differences in extent of dissection associated with this approach and a second, popular robotic thyroidectomy technique.

Design:

Surgical simulation and morphometric analysis in fresh human cadavers.

Methods:

Eleven specimens were obtained to complete four experiments designed to address two specific aims: to develop a reproducible surgical protocol for robotic removal of the thyroid through a facelift incision, and to quantify the extent of dissection required with two robotic thyroidectomy techniques.

Results:

The feasibility of the facelift approach was determined using an endoscopic technique, and two lobectomies were accomplished. Inanimate study of the optimal robotic positioning to facilitate resection was then completed. Three additional cadavers were used to develop a reproducible surgical protocol and define a stepwise algorithm of dissection. Seven specimens were used to simulate 28 robotic thyroidectomy dissection pockets. The mean area of dissection required for robotic facelift thyroidectomy was 39.2 ± 6.6 cm2 compared with 63.5 ± 9.6 cm2 for robotic axillary thyroidectomy, representing a difference of 38.3% (P < .0001).

Conclusions:

We have described and refined a reproducible surgical protocol for accomplishing a new robotic facelift thyroidectomy, and then quantified the reduced dissection required when comparing it with a transaxillary technique. Cautious clinical implementation to explore safety and feasibility appears to be justified.
A Poly(acrylic acid)‐block‐Poly(L‐glutamic acid) Diblock Copolymer with Improved Cell Adhesion for Surface Modification
Authors: Cao Bin , Yan Shifeng , Zhang Kunxi , Song Zhijiang , Cao Tian , Chen Xuesi , Cui Lei , Yin Jingbo
Published: April 2011

A novel PAA‐b‐PLGA diblock copolymer is synthesized and characterized that has excellent cell adhesion and biocompatibility. Fluorescent DiO labeling is used to monitor the attachment and growth of hASCs on the film surface, and cell proliferation over time is studied. Results show that PLLA modified by a CS/PAA‐b‐PLGA multilayer film can promote the attachment of human hASCs and provide an advantageous environment for their proliferation. The multilayer film presents excellent biocompatibility and cell adhesive properties, which will provide a new choice for improving the cell attachment in surface modification for tissue engineering. Hydroxyl, carboxyl and amine groups in the CS/PAA‐b‐PLGA multilayer film may be combined with drugs and growth factors for therapy and differentiation.

magnified image
On the Mechanism of the Ring‐Expansion Polymerization of Thiiranes
Authors: Schuetz Jan‐Hendrik , Vana Philipp
Published: April 2011

Ring polymers are synthesized using a cyclic bifunctional thioester as initiator for REP of thiiranes. PMT yields satisfactory results, whereas polymerization with MT appears to develop dead polymeric material as by‐product and TBMT gives only negligible conversion rates. The process produces high yields and high conversion rates. The corresponding molecular weight distributions show increasing broadening and multimodal character with increasing reaction time due to thermodynamically controlled ring‐merging reactions between macrocycles. The polymerization rate of PMT obeys a pseudo first‐order kinetics with an activation energy of 38.8 kJ mol−1. 1H NMR, ESI‐MS, and glass transition temperatures independent of the molecular weight demonstrate the presence of cyclic polymer.

magnified image
Polyurea With L‐Lysinyl Residues as Components: Application to Membrane Separation of Enantiomers
Authors: Hatanaka Makoto , Nishioka Yuki , Yoshikawa Masakazu
Published: April 2011

Novel polyureas are synthesized from lysinyl residues. The polyurea thus prepared yields a durable self‐standing membrane that can be converted into a molecular recognition material by using Z‐D‐Glu or Z‐L‐Glu as a print molecule. The Z‐D‐Glu molecularly imprinted membrane adsorbes the D‐isomer of Glu in preference to the corresponding L‐Glu and vice versa. Even though the polyurea consists of L‐lysinyl residues, both Z‐D‐Glu and Z‐L‐Glu work as print molecules to construct molecular (chiral) recognition sites in the membrane. Those molecularly imprinted membranes show chiral separation abilities when a concentration gradient or an applied potential difference is applied as a driving force for membrane transport.

magnified image
Fluorescence “Turn‐On” Patterning With Polymers Having Pendant Triphenylmethane Groups as Fluorophore Precursors
Authors: Kim Junwoo , Cho Jaehwa , Lee Jung , Park Kihong , Kim Jong‐Man
Published: April 2011

A new methodology for creating patterned fluorescence images was developed based on acrylate polymers that have pendant triphenylmethane derivatives as precursor fluorophores. Photoinduced oxidation of the substituted nonfluorescent triphenylmethane substituents on the polymers results in the generation of fluorescent cationic species. Patterned fluorescence images were obtained when the polymer film was subjected to photomasked UV‐irradiation. The rate of formation and quality of the patterned images were found to be dependent on the nature of substituents on the methane carbon of the triphenylmethane group. Inefficient image formation takes place with the polymer derived from the H‐substituted derivative owing to the inefficient oxidation of the triphenylmethane group. In contrast, photomasked UV‐irradiation of a thin polymer film derived from the CN‐substituted triphenylmethane derivative leads to fast (1 s irradiation, 12 mW · cm−2) and finely resolved patterned fluorescence images.

magnified image
A new diagnostic test to distinguish tremulous Parkinson's disease from advanced essential tremor
Authors: Muthuraman Muthuraman , Hossen Abdulnasir , Heute Ulrich , Deuschl Günther , Raethjen Jan
Published: April 2011

Background:

Clinical distinction between advanced essential tremor and tremulous Parkinson's disease can be difficult.

Methods:

In selected power spectra of accelerometric postural tremor recordings on the more affected side of 41 patients with essential tremor and 39 patients with tremulous Parkinson's disease being indistinguishable by tremor frequency, peak power or number of harmonic peaks, waveform asymmetry (autocorrelation decay), and mean peak power of all harmonic peaks were computed. Cutoff for essential tremor–Parkinson's disease distinction was determined by receiver operating characteristics. Diagnostic yield was tested in 12 clinically unclear patients with monosymptomatic tremor, subsequently definitively diagnosed with essential tremor (n = 2) or Parkinson's disease (n = 10) by 123‐I FP‐CIT–single‐photon emission computed tomography, fluorodopa‐positron emission tomography, or clinical course.

Results:

By autocorrelation decay 64%, by mean harmonic peak power 94% (Parkinson's disease > essential tremor) of patients with a definite clinical diagnosis, and 11 of 12 clinically unclear patients were classified correctly.

Conclusions:

Mean harmonic power is a useful measure to separate clinically difficult cases of advanced essential tremor from tremulous Parkinson's disease. © 2011 Movement Disorder Society
HIV‐1 NNRTIs: structural diversity, pharmacophore similarity, and impliations for drug design
Authors: Zhan Peng , Chen Xuwang , Li Dongyue , Fang Zengjun , De Clercq Erik , Liu Xinyong
Published: April 2011

Nonnucleoside reverse transcriptase inhibitors (NNRTIs) nowadays represent very potent and most promising anti‐AIDS agents that specifically target the HIV‐1 reverse transcriptase (RT). However, the effectiveness of NNRTI drugs can be hampered by rapid emergence of drug‐resistant viruses and severe side effects upon long‐term use. Therefore, there is an urgent need to develop novel, highly potent NNRTIs with broad spectrum antiviral activity and improved pharmacokinetic properties, and more efficient strategies that facilitate and shorten the drug discovery process would be extremely beneficial. Fortunately, the structural diversity of NNRTIs provided a wide space for novel lead discovery, and the pharmacophore similarity of NNRTIs gave valuable hints for lead discovery and optimization. More importantly, with the continued efforts in the development of computational tools and increased crystallographic information on RT/NNRTI complexes, structure‐based approaches using a combination of traditional medicinal chemistry, structural biology, and computational chemistry are being used increasingly in the design of NNRTIs. First, this review covers two decades of research and development for various NNRTI families based on their chemical scaffolds, and then describes the structural similarity of NNRTIs. We have attempted to assemble a comprehensive overview of the general approaches in NNRTI lead discovery and optimization reported in the literature during the last decade. The successful applications of medicinal chemistry strategies, crystallography, and computational tools for designing novel NNRTIs are highlighted. Future directions for research are also outlined.
Recent attempts at RNAi‐mediated P‐glycoprotein downregulation for reversal of multidrug resistance in cancer
Authors: Abbasi Meysam , Lavasanifar Afsaneh , Uludaˇ Hasan
Published: April 2011

Multidrug resistance (MDR) is among the major mechanisms leading to failure in chemotherapy of cancer patients. The ATP‐binding cassette proteins are major contributors to MDR, involved in the active efflux of xenobiotics out of cancer cells. Among them, P‐glycoprotein (P‐gp) is the most dominant protein involved in the efflux of drugs. For more than 30 years, scientists have searched for the ideal P‐gp inhibitor to modulate drug resistance activity of P‐gp. This inhibitor should be tissue and cell specific with side effects on other tissues, must not provoke immune responses from the host, should provide sustained inhibition, and must be synthesized readily with low cost. Chemical P‐gp inhibitors tested to date, have shown nonspecific toxic effects limiting their clinical applications. Sequence‐specific P‐gp gene silencing by RNA interference (RNAi) may provide a more effective approach for downregulation of specific protein targets due to high specificity, limited toxicity and immunogenicity, and relative ease in synthesis. RNAi can be implemented by delivery of synthetic small interfering RNAs (siRNAs) or by gene expression of short hairpin RNAs using gene expressing vectors. Specific delivery systems and expression vectors have been designed for this purpose and many researchers have explored their effectiveness for P‐gp downregulation. In this report, we review the efficiency of various methods for siRNA delivery and transfection for P‐gp downregulation in cancer cells for MDR reversal. Novel ideas and observations by different research groups were discussed for future improvement in this essential field. © 2011 Wiley Periodicals, Inc. Med Res Rev
Radiofrequency pulse designs for three‐dimensional MRI providing uniform tipping in inhomogeneous B1 fields
Authors: Liu Hui , Matson Gerald B.
Published: April 2011

Although high‐field MRI offers increased signal‐to‐noise, the nonuniform tipping produced by conventional radiofrequency (RF) pulses leads to spatially dependent contrast and suboptimal signal‐to‐noise, thus complicating the interpretation of the MR images. For structural imaging, three‐dimensional sequences that do not make use of frequency‐selective RF pulses have become popular. Therefore, the aim of this research was to develop non‐slice‐selective (NSS) RF pulses with immunity to both amplitude of (excitation) RF field (B1) inhomogeneity and resonance offset. To accomplish this, an optimization routine based on optimal control theory was used to design new NSS pulses with desired ranges of immunity to B1 inhomogeneity and resonance offset. The design allows the phase of transverse magnetization produced by the pulses to vary. Although the emphasis is on shallow tip designs, new designs for 30°, 60°, 90°, and 180° NSS RF pulses are also provided. These larger tip angle pulses are compared with recently published NSS pulses. Evidence is presented that the pulses presented in this article have equivalent performance but are shorter than the recently published pulses. Although the NSS pulses generate higher specific absorption rates and larger magnetization transfer effects than the rectangular pulses they replace, they nevertheless show promise for three‐dimensional MRI experiments at high field. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
In vivo and ex vivo MR imaging of slowly cycling melanoma cells
Authors: Magnitsky S. , Roesch A. , Herlyn M. , Glickson J. D.
Published: April 2011

Slowly cycling cells are believed to play a critical role in tumor progression and metastatic dissemination. The goal of this study was to develop a method for in vivo detection of slowly cycling cells. To distinguish these cells from more rapidly proliferating cells that constitute the vast majority of cells in tumors, we used the well‐known effect of label dilution due to division of cells with normal cycle and retention of contrast agent in slowly dividing cells. To detect slowly cycling cells, melanoma cells were labeled with iron oxide particles. After labeling, we observed dilution of contrast agent in parallel with cell proliferation in the vast majority of normally cycling cells. A small and distinct subpopulation of iron‐retaining cells was detected by flow cytometry after 20 days of in vitro proliferation. These iron‐retaining cells exhibited high expression of a biological marker of slowly cycling cells, JARID1B. After implantation of labeled cells as xenografts into immunocompromised mice, iron‐retaining cells were detected in vivo and ex vivo by magnetic resonance imaging that was confirmed by Prussian Blue staining. Magnetic resonance imaging detects not only iron retaining melanoma cells but also iron positive macrophages. Proposed method opens up opportunities to image subpopulation of melanoma cells, which is critical for continuous tumor growth. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Micromechanical modelling of erosion due to evaporation in a partially wet granular slope
Authors: Gabrieli F. , Lambert P. , Cola S. , Calvetti F.
Published: April 2011

Small quantities of water in a granular slope increase the overall stability and justify the large slope angle which is sometime observable in nature. However, the evaporation usually changes the water content of soil, especially in very shallow layers, leading to a soil strength reduction and the trigger of erosion processes. This work presents some numerical tests simulating a small slope physical model constituted of monosized glass ballotini in a pendular state. After a brief review of the different theories describing the capillary bridge which forms between two spheres and its effects on inter‐particle forces, this paper deals with the implementation of the minimum energy approach within a discrete element model (DEM). Some numerical triaxial tests with different water contents and confinement stresses were performed: the analyses permitted to emphasize the shear strength increase occurring at low water content. Moreover, moving from the observations performed in the physical model, a law relating the evaporation rate with depth and air–water interface was also included in the DEM. Finally, the improved DEM was successfully adopted in the simulation of the erosion process occurring in the physical model: it very well captures the formation of a talus slope profile, typical of the long‐term evolution of granular slopes. The monitoring of soil displacements and suction distribution during the numerical test also allows for the evaluation of erosion mechanisms: for instance, both in experimental and numerical tests, it was observed a rigid displacement at the slope toe after the initial phase of shallow erosion. Copyright © 2011 John Wiley & Sons, Ltd.
Symposium introduction: Dynamics of governance and civic engagement
Authors: Lee Eliza , Thynne Ian
Published: April 2011

This Introduction sets the scene for the Symposium. It considers the governance value of civic engagement, along with civic engagement as identifiable modes of governance. Such matters are embraced in the subsequent analyses of significant developments and experience in South Korea, the Philippines, Australia, Hong Kong and China. Copyright © 2011 John Wiley & Sons, Ltd.
Civic engagement, politics and policy in South Korea: Significant developments but a considerable way to go
Authors: Kim Pan Suk
Published: April 2011

Open and inclusive political systems are needed as means of improving democratic performance in an era of democratic governance. A government can benefit from wider public engagement when deliberating, deciding and carrying out public policy. In this article, the focus is on civic engagement in politics and the policy process in South Korea where government, at all levels, now uses a variety of engagement strategies and means. The discussion includes a brief overview of civic engagement, politics and policy. This is followed by an analysis of the growth of civil society and the civil society index in South Korea, and of various means of citizen engagement in the policy process. The overall conclusion is that civil society is relatively well developed with some citizen involvement in the policy process, but that there are still several barriers to participation and thus a considerable way to go in fostering its widespread occurrence and impact. Copyright © 2011 John Wiley & Sons, Ltd.
How to win friends and influence people: Civic engagement in the Philippines
Authors: Turner Mark
Published: April 2011

The Philippines has the most vibrant and largest civil society in Southeast Asia, which engages constantly with government and has achieved some notable successes. This article traces the origins of the main components of this civil society—the numerous non‐governmental organisations (NGOs)—and delineates their differing characteristics. NGO operations are then examined through the use of network analysis. This approach focuses on the relationships linking NGOs to one another and to the multiplicity of other actors in their arenas of operation, particularly government organisations, thus enabling an appreciation of the complex interactions that occur as NGOs negotiate their environments to achieve their goals. Also relevant are the various strategies and tactics used by NGOs to promote their values, ideologies and activities. These include advocacy, research, capacity building, legislative lobbying and protest. Clearly, while the civic engagement of NGOs in the Philippines has been much celebrated, the societal changes they facilitate are typically incremental in nature. They require continued vigilance and action to ensure sustainability in the context of a weak state where the particularistic demands of politicians are prominent and the state lacks capacity to provide the services it promises. Copyright © 2011 John Wiley & Sons, Ltd.
Civic engagement through participatory budgeting in China: Three different logics at work
Authors: He Baogang
Published: April 2011

This article seeks to develop an understanding of participatory budgeting (PB) in China by examining its three distinctive logics—administrative, political reform and citizen empowerment—and how they operate and intertwine. The background to recent PB is outlined, followed by an overview of the three logics, the mapping of PB developments and activities across China, a discussion of various patterns and related characteristics of PB, an evaluation of PB against a number of criteria within the three logics and a consideration of the prospects for PB. The analysis draws on several sources, including newspaper and journal articles, personal involvement in five PB experiments over the last 6 years, and numerous field trips and interviews with national and local officials. The overall conclusion is that, while the administrative logic will remain dominant in PB experiments, the empowering of local People's Congresses will continue to be constrained by the caution of the central leaders and resistance from local governments. Likewise, the empowering of citizens through PB will be limited by government control. Copyright © 2011 John Wiley & Sons, Ltd.
Australian experience: Civic engagement as symbol and substance
Authors: Head Brian W.
Published: April 2011

This article outlines how civic engagement has become a distinctive feature of the policy development and review processes of governments in Australia, a federal polity. The patterns of civic engagement are quite variable across policy issues, levels of government and geographical regions. Civic engagement (or community consultation) has become a purposeful and planned dimension of policy development in most Australian jurisdictions since the 1980s. Two main reasons for this development are elaborated: the instrumental arguments about programme improvement and effectiveness, and the normative arguments about democratic legitimacy and rights to civic participation. The role of government‐sponsored processes for civic engagement is contrasted with the proliferation of new media and independent civil‐society forums available for commentary and advocacy. Key distinctions are drawn between various processes and methods of civic engagement in Australia, raising issues about the scope and authenticity of participation on different types of issues. There are specific challenges of involvement by and for indigenous communities, and the special needs of remote communities whose level of social and economic exclusion remains seriously depressed. The conclusions raise some implications for policy development and for state legitimacy arising from impoverished forms of civic engagement. Copyright © 2011 John Wiley & Sons, Ltd.
Searching for contracting patterns over time: Do prime contractor and subcontractor relations follow similar patterns for professional services provision?
Authors: Ponomariov Branco , Kingsley Gordon , Boardman Craig
Published: April 2011

This paper compares over a 12‐year period (1) patterns of contracting between a state transportation agency and its prime contractors providing engineering design services with (2) patterns between these prime contractors and their subcontractors. We find evidence of different contracting patterns at each level that emerge over time and coexist in the same contracting context. While patterns at the agency–prime level are characterized by repeated contracts, patterns at the prime–sub level indicate fewer repeats and more contractor turnover. Implications for outsourcing practice and theory are discussed. © 2011 by the Association for Public Policy Analysis and Management.
Sulfonic acid polymer–densely grafted poly(ethersulfone)s for a highly proton‐conducting membrane
Authors: Okayasu Teruyuki , Hirose Koji , Nishide Hiroyuki
Published: April 2011

Proton‐conducting polyelectrolytes were prepared by densely grafting novel sulfonic acid polymers, poly(styrenesulfamide acid) (PSA) and poly(vinylsulfonic acid) (PVS), on the azo‐initiator‐modified poly(ethersulfone) (PSU). The grafted PSUs provided both a high ion‐exchange capacity (IEC) and a good membrane formability. The proton‐conductivities of the PSA‐g‐PSU and PVS‐g‐PSU membranes were 8.2 and 21 mS cm−1, respectively, at 90°C under a hydrated condition, and 4.1 and 1.7 mS cm−1, respectively, at 150°C under a nonhumidified condition. The latter conductivities were significantly higher than that of Nafion® 117 (0.03 mS cm−1 at 150°C), which was ascribed to both the strong acidity of the graft chains even under the water‐free state and the high IEC of the densely grafted membrane. They remained constant for over 1 week at 150°C. Copyright © 2011 John Wiley & Sons, Ltd.
Synthesis and characterization of amphiphilic antibacterial copolymers
Authors: Bai Yong Xiao , Liu Yao Bin , Li Yan Feng , Zhang Qi
Published: April 2011

Macromolecule antimicrobials have been explored in foundational research and practical application due to their potential merit for reducing the residual toxicity, increasing their efficiency, selectivity, and prolonging the lifetime of the antimicrobial material. In this work, the quaternized poly(styrene)‐b‐poly(DMAEMA) diblock polymers are synthesized by reversible addition‐fragmentation chain transfer polymerization (RAFT). The minimum inhibitory concentration (MIC) evaluation and optical density (OD) method demonstrated that the amphiphilic antibacterial biomaterials have exceptional antibacterial properties. The amphiphilic polycation has an admirable antibacterial property, and these quaternized diblocks are potent biocides and nonhemolytic. The relationship between the structure and activity is discussed with respect to molecular weight of the diblocks and bacteria structural dependence. Copyright © 2011 John Wiley & Sons, Ltd.
Development and thermo‐mechanical behavior of nanocomposite epoxy adhesives
Authors: Dorigato Andrea , Pegoretti Alessandro
Published: April 2011

Two kinds of organo‐modified (OM) clays were dispersed in an epoxy resin for the preparation of nanocomposite adhesives at various filler amounts. XRD tests evidenced the formation of intercalated structures, increasing the intercalation degree with the clay hydrophilicity. The original transparency of the samples was retained up to a filler content of 3 wt%, and then decreased due to filler agglomeration. The glass transition temperature of nanocomposites filled with the more hydrophilic clay (30B) raised up to a filler content of 3 wt% and then decreased, probably because of the concurrent and contrasting effects of the physical chain blocking and reduction of the cross‐linking degree. Also elastic modulus, stress at break, and fracture toughness were sensibly improved by nanoclay addition up to filler loadings of 0.5–1 wt%. For higher concentrations the positive contribution of clay nanoplatelets was counterbalanced by the presence of agglomerated tactoids in the matrix. Mechanical tests on single‐lap composite (epoxy/glass) bonded joints evidenced an enhancement of the shear strength by about 25% for an optimal filler content of 1 wt%. Therefore, it was concluded that the addition of a proper amount of OM clay to epoxy adhesives could represent an effective way to improve the shear resistance of adhesively bonded composite structures. Copyright © 2011 John Wiley & Sons, Ltd.
Control of cell morphology on the polyimide surface patterned by rubbing and ion‐irradiation
Authors: Hiruma Hitomi , Asayama Shoichiro , Kawakami Hiroyoshi
Published: April 2011

In this study, we have prepared a rubbed fluorinated polyimide membrane using a rubbing machine with a rubbing cloth, followed by ion‐irradiation, and formed hepatocyte spheroids on the resulting patterned membrane. The re‐seeding of the spheroids, that is, spheroid building, enhanced the biochemical functions of the spheroids by optimization of the culture conditions. Furthermore, the tubular formation of bovine aortic endothelial cells (BAECs) on the resulting patterned membrane has been demonstrated. The pre‐network structure of BAECs was observed, forming the network and tube formation after gel culture. The combination of the built spheroids and the resulting BAEC network is expected to be a unique method to regenerative damaged tissues. Copyright © 2011 John Wiley & Sons, Ltd.