bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental investigation of the effect of particle cohesion on the flow dynamics in a spheronizer
Authors: Bouffard J. , Cabana A. , Chaouki J. , Bertrand F.
Published: October 2012

The effect of particle cohesion on the flow dynamics inside a spheronizer is investigated by means of a recent technique developed in our group, which relies on the polymer coating of the particles. It is shown that the interparticle forces can be controlled with the temperature and the coating thickness, as is also confirmed by measurements of the dynamic density of the particle bed. Four different flow states were observed as the level of interparticle forces was increased. The results are reported in a flow map that compares the forces that come into play in the spheronizer with other interparticle forces encountered during wet granulation processes. By isolating the impact of the cohesive forces on granulation, these results show the potential of the polymer coating technique to study the effect of particle cohesion on the flow patterns in such processes. © 2012 American Institute of Chemical Engineers AIChE J, 59: 1491–1501, 2013
Immunoparesis and monoclonal gammopathy of undetermined significance are disassociated in advanced age
Authors: Cherry Benjamin M. , Costello Rene , Zingone Adriana , Burris Jason , Korde Neha , Manasanch Elisabet , Kwok Mary , Annunziata Christina , Roschewski Mark J. , Engels Eric A. , Landgren Ola
Published: October 2012

Immunoparesis and a skewed serum free light chain (FLC) ratio are indicators of immune dysfunction predictive of progression from monoclonal gammopathy of undetermined significance (MGUS) to multiple myeloma (MM). Previous studies have reported increased prevalence of MGUS by age, but no study has examined the relationship between immunoparesis and abnormal FLC ratios in the elderly. We screened 453 older adults (median age, 80 years; range, 65–96) to characterize the patterns of immunoparesis and abnormal FLC ratio in relation to MGUS. We defined MGUS in 4.4% of the subjects; the prevalence was 12.5% among individuals of >90 years. In MGUS (vs. non‐MGUS) cases, immunoparesis and abnormal FLC ratios were detected in 70.0% (vs. 49.0%; P = 0.07) and 50.0% (vs. 12.9%; P = 0.0001), respectively. Based on small numbers, MGUS patients with abnormal FLC ratio were borderline (P = 0.07) more likely to have immunoparesis. Overall, the prevalence of immunoparesis varied in a nonlinear fashion, with lowest frequencies in the youngest and oldest groups. Our observed disassociation between MGUS prevalence and impaired immunoglobulin production suggests that separate mechanisms are involved in the development of MGUS and immunoparesis in advanced age. These findings emphasize the need for molecularly defined methods to characterize myeloma precursor states and better predict progression to MM. Am. J. Hematol. 88:89–92, 2013. © 2012 Wiley Periodicals, Inc.
Safety, incentives, and the reporting of work‐related injuries among union carpenters: “You're pretty much screwed if you get hurt at work”
Authors: Lipscomb Hester J. , Nolan James , Patterson Dennis , Sticca Vince , Myers Douglas J.
Published: October 2012

Background

In the high‐risk construction industry little is known about the prevalence or effects of programs offering rewards for workers and/or their supervisors for improved safety records or those that punish workers in some way for injury.

Methods

We conducted an anonymous survey of 1,020 carpenter apprentices in three union training programs to document prevalence of their exposure to such efforts. We explored associations between perceptions of the reporting of work‐related injury and elements of these programs.

Results

Fifty‐eight percent (58%; n = 592) reported some safety incentive or negative consequence of work‐related injuries on their current jobsite. Reporting of work‐related injuries was 50% less prevalent when workers were disciplined for injury experiences. Otherwise, we saw minimal evidence of association between injury reporting practices and safety incentive programs. However, considerable evidence of fear of reprisal for reporting injuries was revealed. Less than half (46.4%) reported that work‐related injuries were reported in their current workplace all or most of the time; over 30% said they were almost never or rarely reported.

Conclusions

There are multiple layers of disincentives to the reporting of work‐related injuries that hamper understanding of risk and pose threats to workplace safety and productivity. These pressures do not arise in a vacuum and are likely influenced by a host of contextual factors. Efforts that help us understand variation across jobsites and time could be enlightening; such inquiries may require mixed methodologies and should be framed with consideration for the upper tiers of the public health hierarchy of hazard control. Am. J. Ind. Med. 56:389–399, 2013. © 2012 Wiley Periodicals, Inc.
Permanent tooth mineralization in bonobos (Pan paniscus) and chimpanzees (P. troglodytes)
Authors: Boughner Julia C. , Dean M. Christopher , Wilgenbusch Chelsea S.
Published: October 2012

The timing of tooth mineralization in bonobos (Pan paniscus) is virtually uncharacterized. Analysis of these developmental features in bonobos and the possible differences with its sister species, the chimpanzee (P. troglodytes), is important to properly quantify the normal ranges of dental growth variation in closely related primate species. Understanding this variation among bonobo, chimpanzee and modern human dental development is necessary to better contextualize the life histories of extinct hominins. This study tests whether bonobos and chimpanzees are distinguished from each other by covariance among the relative timing and sequences of tooth crown initiation, mineralization, root extension, and completion. Using multivariate statistical analyses, we compared the relative timing of permanent tooth crypt formation, crown mineralization, and root extension between 34 P. paniscus and 80 P. troglodytes mandibles radiographed in lateral and occlusal views. Covariance among our 12 assigned dental scores failed to statistically distinguish between bonobos and chimpanzees. Rather than clustering by species, individuals clustered by age group (infant, younger or older juvenile, and adult). Dental scores covaried similarly between the incisors, as well as between both premolars. Conversely, covariance among dental scores distinguished the canine and each of the three molars not only from each other, but also from the rest of the anterior teeth. Our study showed no significant differences in the relative timing of permanent tooth crown and root formation between bonobos and chimpanzees. Am J Phys Anthropol, 2012. © 2012 Wiley Periodicals, Inc.
Plasmonics and single‐molecule detection in evaporated silver‐island films
Authors: Moula G. , Rodriguez‐Oliveros R. , Albella P. , Sanchez‐Gil J.A. , Aroca R.F.
Published: October 2012

The plasmonic origin of surface‐enhanced Raman scattering (SERS) leads to the concept of hotspots and plasmon coupling that can be realized in the interstitial regions, or on specially engineered, silver and gold nanostructures. It is also possible to achieve spatial locations of high local field or hotspots on silver‐island films (SIF) allowing single‐molecule detection (SMD). When a single monomolecular layer coating the SIFs contains dye molecules dispersed in it, single‐molecule impurities, (with an average of one hundred dye molecules in 1 µm2, which is the field of view of the micro‐Raman system), SMD is observed as a rare statistical event. Here, the SMD results for silver‐island films are presented, with the same nominal mass thickness, but differing in the localized surface plasmon resonance that is a function of the temperature of substrate during deposition. A blue‐shifted plasmon can be seen as a decrease in plasmon coupling for deposition at higher temperature. A simple two‐particle model for localized plasmon resonance coupling calculations, including the shape and substrate effects seems to explain the trend of observations.
Curing and thermal behaviors of inorganic–organic hybrid polyarylacetylene resins with polyhedral oligomeric octa(propargylaminophenyl)silsesquioxane
Authors: Fan Haibo , Li Xiangmei , Liu Yanlin , Yang Rongjie
Published: October 2012

Polyhedral oligomeric octa(propargylaminophenyl)silsesquioxane (OPAPS) was used to prepare composite resins with prepolyarylacetylene (prePAA). The curing and thermal behaviors of the PAA/OPAPS composites were studied through Fourier‐transform infrared (FTIR), X‐ray diffraction (XRD), differential scanning calorimetric (DSC), thermogravimetric (TGA), and scanning electron microscopic (SEM) analysis and by direct observation. The morphologies of the PAA/OPAPS resins proved that there was good compatibility between PAA and OPAPS. FTIR analysis indicated formation of a conjugated diene and aromatic ring groups in the thermal curing process of the resins. DSC analysis implied that the addition of OPAPS to prePAA could decrease the exothermic heat and widen the temperature range in the curing process of prePAA. According to TGA analysis, a 10 wt % addition of OPAPS to PAA can maintain the thermal stability of PAA in N2 atmosphere and somewhat enhance the thermal‐oxidative stability. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013
Contribution of salivary gland ultrasonography to the diagnosis of Sjögren's syndrome: Toward new diagnostic criteria?
Authors: Cornec Divi , Jousse‐Joulin Sandrine , Pers Jacques‐Olivier , Marhadour Thierry , Cochener Béatrice , Boisramé‐Gastrin Sylvie , Nowak Emmanuel , Youinou Pierre , Saraux Alain , Devauchelle‐Pensec Valérie
Published: October 2012

Objective

To determine the accuracy of salivary gland ultrasonography (SGUS) for diagnosing primary Sjögren's syndrome (SS) and to suggest modifications of the American–European Consensus Group (AECG) classification criteria.

Methods

We conducted a cross‐sectional study in a prospective cohort of patients with suspected primary SS that was established between 2006 and 2011. The echostructure of the bilateral parotid and submandibular glands was graded from 0 to 4, and the gland size was measured; blood flow to the parotid gland was assessed using Doppler waveform analysis. The reference standard was a clinical diagnosis of primary SS as determined by a group of experts blinded to the results of SGUS. Receiver operating characteristic (ROC) curve analysis was performed to compare the diagnostic value of the 0–4‐point echostructure grade for each of the 4 major salivary glands, the sum of the grades for the 4 glands, and the highest grade among the 4 glands.

Results

Of the 158 patients in the study, 78 had a diagnosis of primary SS according to the experts, including 61 patients (78.2%) who met the AECG criteria. Doppler waveform analysis and gland size measurement showed poor diagnostic performance. The results of ROC curve analysis showed that the highest grade among the 4 glands provided the best diagnostic value. The optimal grade cutoff was 2 (62.8% sensitivity and 95.0% specificity). A weighted score was constructed using scores for the 5 variables selected by logistic regression analysis, as follows: (salivary flow × 1.5) + (Schirmer's test × 1.5) + (salivary gland biopsy × 3) + (SSA/SSB × 4.5) + (SGUS × 2). According to ROC curve analysis, a score of ≥5 of 12.5 had 85.7% sensitivity and 94.9% specificity, compared with 77.9% sensitivity and 98.7% specificity for the AECG criteria. The addition of SGUS to the AECG criteria increased sensitivity to 87.0% but did not change specificity.

Conclusion

Modifications of the AECG criteria, including the addition of a SGUS score, notably improved diagnostic performance.
mRNA display selection and solid‐phase synthesis of Fc‐binding cyclic peptide affinity ligands
Authors: Menegatti Stefano , Hussain Mahmud , Naik Amith D. , Carbonell Ruben G. , Rao Balaji M.
Published: October 2012

Cyclic peptides are attractive candidates for synthetic affinity ligands due to their favorable properties, such as resistance to proteolysis, and higher affinity and specificity relative to linear peptides. Here we describe the discovery, synthesis and characterization of novel cyclic peptide affinity ligands that bind the Fc portion of human Immunoglobulin G (IgG; hFc). We generated an mRNA display library of cyclic pentapeptides wherein peptide cyclization was achieved with high yield and selectivity, using a solid‐phase crosslinking reaction between two primary amine groups, mediated by a homobifunctional linker. Subsequently, a pool of cyclic peptide binders to hFc was isolated from this library and chromatographic resins incorporating the selected cyclic peptides were prepared by on‐resin solid‐phase peptide synthesis and cyclization. Significantly, this approach results in resins that are resistant to harsh basic conditions of column cleaning and regeneration. Further studies identified a specific cyclic peptide—cyclo[Link‐M‐WFRHY‐K]—as a robust affinity ligand for purification of IgG from complex mixtures. The cyclo[Link‐M‐WFRHY‐K] resin bound selectively to the Fc fragment of IgG, with no binding to the Fab fragment, and also bound immunoglobulins from a variety of mammalian species. Notably, while the recovery of IgG using the cyclo[Link‐M‐WFRHY‐K] resin was comparable to a Protein A resin, elution of IgG could be achieved under milder conditions (pH 4 vs. pH 2.5). Thus, cyclo[Link‐M‐WFRHY‐K] is an attractive candidate for developing a cost‐effective and robust chromatographic resin to purify monoclonal antibodies (mAbs). Finally, our approach can be extended to efficiently generate and evaluate cyclic peptide affinity ligands for other targets of interest. Biotechnol. Bioeng. 2013; 110: 857–870. © 2012 Wiley Periodicals, Inc.
The Influence of Alkali Metals on the Ce‐Ti Mixed Oxide Catalyst for the Selective Catalytic Reduction of NOx
Authors: Du Xuesen , Gao Xiang , Qu Ruiyang , Ji Peidong , Luo Zhongyang , Cen Ke‐fa
Published: October 2012

Alkali metals were found to be poisonous to the Ce‐Ti oxide catalyst. The NO conversion of the catalyst decreased by more than 80 % at temperatures from 250 to 450 °C with the doping of either 3.71 atom % K or 3.74 atom % Na. A combined experimental and theoretical study was used to reveal the mechanism of the deactivation caused be the alkali metals. The results indicated that the doping of alkali metal atoms on the catalyst surface greatly decreases the surface acidity and reducibility. XPS characterization revealed that the interaction between the alkali atoms and the oxygen atom of cerium oxide inhibits the transformation between Ce3+ and Ce4+, which effects a decrease in the proportion of Ce3+. The theoretical results show that the alkali atoms strongly interact with the cerium oxygen and titanium oxygen, which causes the degradation of reducibility and surface acidity, respectively. This causes a serious deactivation of the Ce‐Ti oxide catalyst.
n‐Doping of Organic Electronic Materials Using Air‐Stable Organometallics: A Mechanistic Study of Reduction by Dimeric Sandwich Compounds
Authors: Guo Song , Mohapatra Swagat K. , Romanov Alexander , Timofeeva Tatiana V. , Hardcastle Kenneth I. , Yesudas Kada , Risko Chad , Brédas Jean‐Luc , Marder Seth R. , Barlow Stephen
Published: October 2012

Several 19‐electron sandwich compounds are known to exist as “2×18‐electron” dimers. Recently it has been shown that, despite their air stability in the solid state, some of these dimers act as powerful reductants when co‐deposited from either the gas phase or from solution and that this behavior can be useful in n‐doping materials for organic electronics, including compounds with moderate electron affinities, such as 6,13‐bis[tri(isopropyl)silylethynyl]pentacene (3). This paper addresses the mechanisms by which the dimers of 1,2,3,4,5‐pentamethylrhodocene (1 b2), (pentamethylcyclopentadienyl)(1,3,5‐trialkylbenzene)ruthenium (alkyl=Me, 2 a2; alkyl=Et, 2 b2), and (pentamethylcyclopentadienyl)(benzene)iron (2 c2) react with 3 in solution. Vis/NIR and NMR spectroscopy, and X‐ray crystallography indicate that the products of these solution reactions are 3.− salts of the monomeric sandwich cations. Vis/NIR kinetic studies for the Group 8 dimers are consistent with a mechanism whereby an endergonic electron transfer from the dimer to 3 is followed by rapid cleavage of the dimer cation. NMR crossover experiments with partially deuterated derivatives suggest that the CC bond in the 1 b2 dimer is much more readily broken than that in 2 a2; consistent with this observation, Vis/NIR kinetic measurements suggest that the solution reduction of 3 by 1 b2 can occur by both the mechanism established for the Group 8 species and by a mechanism in which an endergonic dissociation of the dimer is followed by rapid electron transfer from monomeric 1 b to 3.
Photoinduced Fluorescence Activation and Nitric Oxide Release with Biocompatible Polymer Nanoparticles
Authors: Deniz Erhan , Kandoth Noufal , Fraix Aurore , Cardile Venera , Graziano Adriana C. E. , Lo Furno Debora , Gref Ruxandra , Raymo Françisco M. , Sortino Salvatore
Published: October 2012

A viable strategy to encapsulate a fluorophore/photochrome dyad and a nitric oxide photodonor within supramolecular assemblies of a cyclodextrin‐based polymer in water was developed. The two photoresponsive guests do not interact with each other within their supramolecular container and can be operated in parallel under optical control. Specifically, the dyad permits the reversible switching of fluorescence on a microsecond timescale for hundreds of cycles, and the photodonor enables the irreversible release of nitric oxide. Furthermore, these supramolecular assemblies cross the membrane of human melanoma cancer cells and transport their cargo in the cytosol. The fluorescence of one component allows the visualization of the labeled cells, and its switchable character could, in principle, be used to acquire super‐resolution images, while the release of nitric oxide from the other induces significant cell mortality. Thus, our design logic for the construction of biocompatible nanoparticles with dual functionality might evolve into the realization of valuable photoresponsive probes for imaging and therapeutic applications.
The Safety and Efficacy of Enhanced External Counterpulsation as a Treatment for Angina in Patients With Aortic Stenosis
Authors: Braverman Debra L. , Braitman Len , Figeuredo Vincent M.
Published: October 2012

Background:

Comorbid aortic stenosis (AS) has been considered a precaution when applying enhanced external counterpulsation (EECP) to individuals with angina due to concerns about treatment‐related hemodynamic changes.

Hypothesis:

The aim of this study was to determine whether EECP safely reduces symptoms of myocardial ischemia and improves hemodynamics in individuals with AS.

Methods:

Forty‐three patients with AS (average age, 73 years; 86% male) and 43 comparison patients without AS were chosen from a database of 1327 EECP patients. Canadian Cardiovascular Society (CCS) Functional Angina Classification, diastolic augmentation ratio, and blood pressure were measured at baseline and on completion of the course of EECP.

Results:

Thirty‐five of the 43 patients with AS (81%, 95% CI: 66.6% to 91.6%) and 38 of the 43 without AS (88%, 95% CI: 74.9% to 96.1%) improved in angina class (P < 0.0001). There was no statistical difference between the percentages in patients with and without AS (P = 0.54). CCS angina class outcome was not associated with AS severity (P = 0.55). The percentage of patients with diastolic augmentation ratio ≥1.0 was 16.3% in both groups at baseline and improved to 39.5% in AS patients and 37.2% in non‐AS patients after EECP (both P = 0.002). The average decreases in systolic blood pressure in subjects with AS (−15 mm Hg, 95% CI: 11 to 20, P < 0.0001) and without AS (−18 mm Hg, 95% CI: 14 to 22, P < 0.0001) were similar (P = 0.31). No major adverse cardiac events were reported.

Conclusions:

Angina patients with AS who undergo EECP had clinically important symptomatic and hemodynamic improvements comparable to their non‐AS counterparts. Clin. Cardiol. 2012 doi: 10.1002/clc.22073

The authors have no funding, financial relationships, or conflicts of interest to disclose.
River Water Pollution in Developed and Developing Countries: Judge and Assessment of Physicochemical Characteristics and Selected Dissolved Metal Concentration
Authors: Sikder M. Tajuddin , Kihara Yusuke , Yasuda Masaomi , Yustiawati  , Mihara Yoshihiro , Tanaka Shunitz , Odgerel Dalkhjav , Mijiddorj Badamtsetseg , Syawal Suhaemi M. , Hosokawa Toshiyuki , Saito Takeshi , Kurasaki Masaaki
Published: October 2012

To compare water quality in rivers of developed and developing countries, a study based on physicochemical parameters and dissolved metals levels was conducted. Water samples were collected from selected sites in Dhaka, Bangladesh; Hokkaido and Osaka, Japan; Erdenet, Mongolia and West Java, Indonesia. Analysis of least significant differences revealed that most water quality parameters were within comparable low levels in both developed and developing countries. The dissolved metals concentrations were found to be similar and below those of water standards except for manganese and cadmium at every sampling point, and lead in Erdenet, Mongolia. Some metals showed high enrichment factors in the rivers of Osaka, Japan and Erdenet, Mongolia, indicating accumulation possibility of metals in the river‐bed sediments. High concentrations of dissolved organic carbon, Escherichia coli and dissolved metals suggested greater water pollution in some rivers of developing countries than in the rivers of Japan. Principal component analysis showed strong correlations between “dissolved organic carbon and chemical oxygen demand” and “conductivity and total dissolved solids” at each sampling point, and E. coli, nitrate (NO), nitrite (NO), and pH levels were found to be higher in the rivers of Dhaka and Erdenet. In addition, there were high levels of Al and Zn in West Java, Pb in Erdenet, and Mn, Fe, and Cr in the rivers of Dhaka and Japan. Based on pressures and impacts, it is evident that dissolved metal, organic, and fecal pollution in the rivers of developing countries are in somewhat dreadful condition in comparison with the rivers of developed country.
Polarity determination of rough and smooth surface grains in AlN crystals
Authors: Nyakiti L. O. , Lee R. G. , Gu Z. , Edgar J. H. , Chaudhuri J.
Published: October 2012

The polarity of rough and smooth grains in textured aluminum nitride boules were analyzed by transmission electron microscopy. Specifically, convergent beam electron diffraction method was applied to determine polarity. The grains corresponding to smooth and rough surfaces were identified as having Al and N polarities, respectively. Aluminum oxide (Al2O3) was observed to form at the grain boundaries. The oxide may precipitate due to the low mutual solubility between Al2O3 and AlN at the high crystal growth temperature (∼2000°C). Oxygen may be the cause of polarity inversion that leads to the formation of Al and N polar grains.
Microstructural characterization of CPPD and hydroxyapatite crystal depositions on human menisci
Authors: Katsamenis Orestis L. , Karoutsos Vagelis , Kontostanos Konstantinos , Panagiotopoulos Elias C. , Papadaki Helen , Bouropoulos Nikolaos
Published: October 2012

Meniscus is a fibrocartilaginous tissue composed mainly of water and a dense elaborate collagen network with a predominantly circumferential alignment. Crystal formation and accumulation on meniscal tissue is frequently observed especially in elderly. In this study, we used X‐ray diffraction (XRD), FTIR and FT‐Raman for the structural identification of the depositions and Optical microscopy, Scanning Electron microscopy (SEM/EDX) and Atomic Force microscopy (AFM), in order to investigate the structural relationship between the crystal deposits and the collagen fibers of human meniscal tissues. We are reporting on the formation of intercalary “colonies” of Calcium Pyrophosphate Dihydrate (CPPD) crystals with two distinct morphologies corresponding to the monoclinic and the triclinic phase, as well as the formation of micro‐aggregations composed of nano‐crystalline HAP aggregations which are developed along the longitudinal axis of collagen fibers without extensively disturbing the collagens arrangement.
A new handoff management system for heterogeneous wireless access networks
Authors: Mojtaba Matinkhah S. , Khorsandi Siavash , Yarahmadian Shantia
Published: October 2012

In heterogeneous wireless access networks, each mobile terminal may frequently need to change its base station (BS); this change is called a ‘handoff’. BSs have static parameters, which are related to their radio access technologies (RATs); however, they also contain dynamic parameters such as load and signal quality. Therefore, the problem of handoff decision includes two subproblems of RAT selection and BS selection. In this paper, first a ‘heterogeneous handoff management system’ for gathering all different required parameters is proposed. Second, a RAT Selection algorithm based on analytic hierarchy process and a BS Selection algorithm based on data envelopment analysis are designed. Finally, by means of ‘weight restriction’ technique, we develop a method for studying the impact of RAT Selection parameters on the performance of the network. Simulation results indicate that RAT Selection parameters have significant impact on the bandwidth utilization, energy consumption and the whole satisfaction of the users in heterogeneous wireless access networks.Copyright © 2012 John Wiley & Sons, Ltd.
Perception of affect in biological motion cues in anorexia nervosa
Authors: Zucker Nancy , Moskovich Ashley , Bulik Cynthia M. , Merwin Rhonda , Gaddis Katherine , Losh Molly , Piven Joseph , Wagner Henry R. , LaBar Kevin S.
Published: October 2012

Objective:

Nonverbal motion cues (a clenched fist) convey essential information about the intentions of the actor. Individuals with anorexia nervosa (AN) have demonstrated impairment in deciphering intention from facial affective cues, but it is unknown whether such deficits extend to deciphering affect from body motion cues.

Method:

We examined the capacities of adults with AN (n = 21) or those weight restored for ≥12 months (WR; n = 20) to perceive affect in biological motion cues relative to healthy controls (HC; n = 23).

Results:

Overall, individuals with AN evidenced greater deficit in discriminating affect from biological motion cues than WR or HC. Follow‐up analyses showed that individuals with AN differed especially across two of the five conditions—deviating most from normative data when discriminating sadness and more consistently discriminating anger relative to WR or HC.

Discussion:

Implications of these findings are discussed in relation to some puzzling interpersonal features of AN. © 2012 by Wiley Periodicals, Inc. (Int J Eat Disord 2013)
Tracking antigen‐specific CD4+ T cells throughout the course of chronic Leishmania major infection in resistant mice
Authors: Pagán Antonio J. , Peters Nathan C. , Debrabant Alain , Ribeiro‐Gomes Flavia , Pepper Marion , Karp Christopher L. , Jenkins Marc K. , Sacks David L.
Published: October 2012

Primary Leishmania major infection typically produces cutaneous lesions that not only heal but also harbor persistent parasites. While the opposing roles of CD4+ T‐cell‐derived IFN‐γ and IL‐10 in promoting parasite killing and persistence have been well established, how these responses develop from naïve precursors has not been directly monitored throughout the course of infection. We used peptide:Major Histocompatibility Complex class II (pMHCII) tetramers to investigate the endogenous, parasite‐specific primary CD4+ T‐cell response to L. major in mice resistant to infection. Maximal frequencies of IFN‐γ+ CD4+ T cells were observed in the spleen and infected ears within a month after infection and were maintained into the chronic phase. In contrast, peak frequencies of IL‐10+ CD4+ T cells emerged within 2 weeks of infection, persisted into the chronic phase, and accumulated in the infected ears but not the spleen, via a process that depended on local antigen presentation. T helper type‐1 (Th1) cells, not Foxp3+ regulatory T cells, were the chief producers of IL‐10 and were not exhausted. Therefore, tracking antigen‐specific CD4+ T cells revealed that IL‐10 production by Th1 cells is not due to persistent T‐cell antigen receptor stimulation, but rather driven by early antigen encounter at the site of infection.
How are Biogenic Amines Metabolized by Monoamine Oxidases?
Authors: Vianello Robert , Repič Matej , Mavri Janez
Published: October 2012

Monoamine oxidases (MAOs) are flavoenzymes important in regulating amine neurotransmitter levels and are the central pharmacological targets in treating depression and Parkinson's disease. On the basis of quantum chemical calculations, we have proposed a new two‐step hydride mechanism for the MAO‐catalysed oxidative deamination of amines. In the rate‐limiting first step, through its N5 atom, the flavin abstracts a hydride anion from the substrate α‐carbon atom and forms a strong covalent adduct with the thus created cation. This is followed by flavin N1 deprotonation of the substrate amino group, facilitated with two active‐site water molecules, to produce fully reduced flavin, FADH2, and neutral imine. We have demonstrated that our mechanism is in agreement with available experimental data and provided evidence against both traditional polar nucleophilic and single‐electron radical pathways. These results provide valuable information for mechanistic studies on other flavoenzymes and for the design of new antidepressants and antiparkinsonian drugs.
One‐Pot Synthesis of Furo‐ or Thienoquinolines through Sequential Imination and Intramolecular Palladium‐Catalyzed Direct Arylation
Authors: Beydoun Kassem , Doucet Henri
Published: October 2012

The sequential imination and intramolecular palladium‐catalyzed direct arylation of thiophene‐3‐carbaldehyde or furan‐3‐carbaldehyde with 2‐haloanilines provided a one‐pot access to furo‐ or thienoquinolines in high yields with H2O and HBr as the major waste. Both electron‐withdrawing and ‐donating substituents on the 2‐haloaniline derivatives were tolerated. These furo‐ or thienoquinoline derivatives can be employed in the direct arylation at C‐5 of the furyl or thienyl moiety, and a variety of corresponding arylation products were obtained in high yields.
Interest of the Sol‐Gel Approach for Multiscale Tailoring of Porous Bioelectrode Surfaces
Authors: Côme Yémima Bon Saint , Lalo Hélène , Wang Zhijie , Kohring Gert‐Wieland , Hempelmann Rolf , Etienne Mathieu , Walcarius Alain , Kuhn Alexander
Published: October 2012

Gold nanoparticles have been co‐encapsulated with D‐sorbitol dehydrogenase and diaphorase in electrodeposited thin sol‐gel films. We demonstrate here that the nanoparticles allow improving significantly the catalytic efficiency of the bioelectrodes. The hybrid material was electrodeposited in the cavities of macroporous electrodes and characterized by high‐resolution transmission electron microscopy and electrochemistry. Well‐defined silica gel layers containing homogeneously dispersed nanoparticles were obtained, leading to high current densities in the presence of D‐sorbitol. The access to the internal porosity of the macroporous electrode was not hindered by the presence of the electrodeposited sol‐gel layer. In addition, a very significant enhancement factor, that describes the current increase with the increasing macroporous surface area was obtained due to the contribution of the tridimensional gold nanoparticle network.
Enhanced separation of Compound Xueshuantong capsule using functionalized carbon nanotubes with cationic surfactant solutions in MEEKC
Authors: Cao Jun , Li Ping , Chen Jue , Tan Ting , Dai Han‐Bin
Published: October 2012

A novel additive of multi‐walled carbon nanotubes (MWNTs) dispersed with cationic surfactants or mixed cationic/anionic surfactants was used for MEEKC separation of eight phenolic compounds, four glycosides, and one phenanthraquinone. In this context, several parameters affecting MEEKC separation were studied, including the dispersion agents of MWNTs, MWNTs content, oil type, SDS concentration, and the type and concentration of cosurfactant. Compared with conventional MEEKC, the addition of all types of MWNTs dispersions using single or mixed cationic surfactant solutions in running buffers was especially useful for improving the separation of solutes tested, as they influenced the partitioning between the oil droplets and aqueous phase due to the exceptional electrical properties and large surface areas of MWNTs. Use of cationic surfactant‐coated MWNTs (6.4 μg/mL) as the additive in a microemulsion buffer (0.5% octanol, 2.8% SDS, 5.8% isopropanol, and 5 mM borate buffer) yielded complete resolution of 13 analytes. The proposed method has been successfully applied for the detection and quantification of the studied compounds in a complex matrix sample (Compound Xueshuantong capsule).
Rapid superparamagnetic‐beads‐based automated immunoseparation of Zn‐proteins from Staphylococcus aureus with nanogram yield
Authors: Krizkova Sona , Jilkova Eva , Krejcova Ludmila , Cernei Natalia , Hynek David , Ruttkay‐Nedecky Branislav , Sochor Jiri , Kynicky Jindrich , Adam Vojtech , Kizek Rene
Published: October 2012

Pathogenic bacteria have become a serious socio‐economic concern. Immunomagnetic separation‐based methods create new possibilities for rapidly recognizing many of these pathogens. The aim of this study was to use superparamagnetic particles‐based fully automated instrumentation to isolate pathogen Staphylococcus aureus and its Zn(II) containing proteins (Zn‐proteins). The isolated bacteria were immediately purified and disintegrated prior to immunoextraction of Zn‐proteins by superparamagnetic beads modified with chicken anti‐Zn(II) antibody. S. aureus culture was treated with ZnCl2. Optimal pathogen isolation and subsequent disintegration assay steps were carried out with minimal handling. (i) Optimization of bacteria capturing: Superparamagnetic microparticles composed of human IgG were used as the binding surface for acquiring live S. aureus. The effect of antibodies concentration, ionic strength, and incubation time was concurrently investigated. (ii) Optimization of zinc proteins isolation: pure and intact bacteria isolated by the optimized method were sonicated. The extracts obtained were subsequently analyzed using superparamagnetic particles modified with chicken antibody against zinc(II) ions. (iii) Moreover, various types of bacterial zinc(II) proteins precipitations from particle–surface interactions were tested and associated protein profiles were identified using SDS‐PAGE. Use of a robotic pipetting system sped up sample preparation to less than 4 h. Cell lysis and Zn‐protein extractions were obtained from a minimum of 100 cells with sufficient yield for SDS‐PAGE (tens ng of proteins). Zn(II) content and cell count in the extracts increased exponentially. Furthermore, Zn(II) and proteins balances were determined in cell lysate, extract, and retentate.
Formation of phreatic caves in an eogenetic karst aquifer by CO2 enrichment at lower water tables and subsequent flooding by sea level rise
Authors: Gulley J. D. , Martin J. B. , Moore P. J. , Murphy J.
Published: October 2012

Formation of extensive phreatic caves in eogenetic karst aquifers is widely believed to require mixing of fresh and saltwater. Extensive phreatic caves also occur, however, in eogenetic karst aquifers where fresh and saltwater do not mix, for example in the upper Floridan aquifer. These caves are thought to have formed in their modern settings by dissolution from sinking streams or by convergence of groundwater flow paths on springs. Alternatively, these caves have been hypothesized to have formed at lower water tables during sea level low‐stands. These hypotheses have not previously been tested against one another. Analyzing morphological data and water chemistry from caves in the Suwannee River Basin in north‐central Florida and water chemistry from wells in the central Florida carbonate platform indicates that phreatic caves within the Suwannee River Basin most likely formed at lower water tables during lower sea levels. Consideration of the hydrological and geochemical constraints posed by the upper Floridan aquifer leads to the conclusion that cave formation was most likely driven by dissolution of vadose CO2 gas into the groundwater. Sea level rise and a wetter climate during the mid‐Holocene lifted the water table above the elevation of the caves and placed the caves tens of meters below the modern water table. When rising water tables reached the land surface, surface streams formed. Incision of surface streams breached the pre‐existing caves to form modern springs, which provide access to the phreatic caves. Phreatic caves in the Suwannee River Basin are thus relict and have no causal relationship with modern surficial drainage systems. Neither mixing dissolution nor sinking streams are necessary to form laterally extensive phreatic caves in eogenetic karst aquifers. Dissolution at water tables, potentially driven by vadose CO2 gas, offers an underappreciated mechanism to form cavernous porosity in eogenetic carbonate rocks. Copyright © 2012 John Wiley & Sons, Ltd.
Silver nanoparticles cause oxidative damage and histological changes in medaka (Oryzias latipes) after 14 days of exposure
Authors: Wu Yuan , Zhou Qunfang
Published: October 2012

Silver nanoparticles (AgNPs) can exert negative effects on cell lines and embryos of freshwater fish. However, information on their distribution and long-term toxicity in adult species is limited. In the present study, a subchronic (14-d) toxicity test was designed to evaluate the bioaccumulation of AgNPs and their effects on the antioxidant defense system and histology of adult medaka. Purified AgNPs were well dispersed in water, and stability was maintained during the exposure period. After 14 d of exposure, a significant accumulation of Ag in the AgNP-dosed group was observed in the gill and intestinal tissues, with the highest levels found in the liver. Biochemical analysis indicated a dose-related decrease in the activity of lactate dehydrogenase and antioxidant enzymes in the liver, but not in the gills. However, dose-dependent increases in glutathione depletion and lipid peroxidation in the liver and gills were observed. Exposure to a graded dose of AgNPs also resulted in varying degrees of histological lesions in the tissues. Toxicological endpoints combined with metal distribution analysis suggested that AgNPs induced tissue-specific toxicity and that the liver is the organ most damaged by the Ag that might have been released from NPs. The oxidative damage caused by AgNPs may be associated with a large number of histological changes in the fish. Environ. Toxicol. Chem. 2013;32:165–173. © 2012 SETAC
Upscaling and its application in numerical simulation of long‐term CO2storage
Authors: Akber Hassan Wasim A. , Jiang Xi
Published: October 2012

Numerical simulations of long‐term geological CO2storage could be particularly useful in predicting the capacity, security, and other consequences of CO2sequestration. The physics of this flow is essentially a multiphase multicomponent phenomenon in a strongly heterogeneous medium necessitating the need for a computationally prohibitive resolution to capture the various physical processes at all scales. Upscaling is an important step in these simulations when going from geostatistical models featuring strong heterogeneities to the simulation models which in practice are limited because of computational restrictions. Although many different upscaling techniques exist, including dynamic and steady‐state methods, thorough analyses of their application to CO2sequestration are not yet established. This review aims to highlight the recent developments in the application of upscaling to the modeling of long‐term CO2storage and provide insights into aspects that could prove valuable to numerical simulations. © 2012 Society of Chemical Industry and John Wiley & Sons, Ltd
Toll‐like receptor 4 is required for α‐synuclein dependent activation of microglia and astroglia
Authors: Fellner Lisa , Irschick Regina , Schanda Kathrin , Reindl Markus , Klimaschewski Lars , Poewe Werner , Wenning Gregor K. , Stefanova Nadia
Published: October 2012

Alpha‐synucleinopathies (ASP) are neurodegenerative disorders, characterized by accumulation of misfolded α‐synuclein, selective neuronal loss, and extensive gliosis. It is accepted that microgliosis and astrogliosis contribute to the disease progression in ASP. Toll‐like receptors (TLRs) are expressed on cells of the innate immune system, including glia, and TLR4 dysregulation may play a role in ASP pathogenesis. In this study we aimed to define the involvement of TLR4 in microglial and astroglial activation induced by different forms of α‐synuclein (full length soluble, fibrillized, and C‐terminally truncated). Purified primary wild type (TLR4+/+) and TLR4 deficient (TLR4−/−) murine microglial and astroglial cell cultures were treated with recombinant α‐synuclein and phagocytic activity, NFκB nuclear translocation, cytokine release, and reactive oxygen species (ROS) production were measured. We show that TLR4 mediates α‐synuclein‐induced microglial phagocytic activity, pro‐inflammatory cytokine release, and ROS production. TLR4−/− astroglia present a suppressed pro‐inflammatory response and decreased ROS production triggered by α‐synuclein treatment. However, the uptake of α‐synuclein by primary astroglia is not dependent on TLR4 expression. Our results indicate the C‐terminally truncated form as the most potent inductor of TLR4‐dependent glial activation. The current findings suggest that TLR4 plays a modulatory role on glial pro‐inflammatory responses and ROS production triggered by α‐synuclein. In contrast to microglia, the uptake of alpha‐synuclein by astroglia is not dependent on TLR4. Our data provide novel insights into the mechanisms of α‐synuclein‐induced microglial and astroglial activation which may have an impact on understanding the pathogenesis of ASP. © 2012 Wiley Periodicals, Inc.
Brain connectivity abnormalities extend beyond the sensorimotor network in peripheral neuropathy
Authors: Rocca Maria A. , Valsasina Paola , Fazio Raffaella , Previtali Stefano C. , Messina Roberta , Falini Andrea , Comi Giancarlo , Filippi Massimo
Published: October 2012

Objectives:

To investigate, using resting state (RS) functional connectivity (FC), the selectivity of involvement of the sensorimotor network in patients with acquired (A) and with hereditary (H) peripheral neuropathies (PN) and the correlations of RS FC abnormalities with clinical impairment and structural brain damage. Temporal associations among RS networks were also explored. Experimental design: RS fMRI scans were acquired from 13 APN, 12 HPN, and 18 age‐ and sex‐matched healthy controls. Independent component analysis and functional network connectivity were used to investigate RS FC within and among RS networks with potential functional relevance.

Principal observations:

Compared to controls, patients had a decreased FC of the right precentral gyrus and an increased RS FC of the precuneus within the sensorimotor network. Both decreased and increased RS FC also involved the visual and auditory networks, which additionally had an increased coherence of function with the sensorimotor network (more pronounced in HPN). RS FC modifications in patients extended to several cognitive networks and were correlated with disease duration. In APN, they were also correlated with the severity of clinical impairment and corpus callosum atrophy.

Conclusions:

In PN, RS FC modifications extend beyond the sensorimotor network and involve other sensory and cognitive networks. The correlations between RS FC patterns and disease duration in patients as well as with clinical impairment in patients with APN suggest that modifications of FC might reflect an adaptive mechanism, which takes time to occur and helps to limit the clinical consequences of peripheral damage. Hum Brain Mapp 35:513–526, 2014. © 2012 Wiley Periodicals, Inc.
Brain systems involved in arithmetic with positive versus negative numbers
Authors: Gullick Margaret M. , Wolford George
Published: October 2012

Positive number arithmetic is based on combining and separating sets of items, with systematic differences in brain activity in specific regions depending on operation. In contrast, arithmetic with negative numbers involves manipulating abstract values worth less than zero, possibly involving different operation–activity relationships in these regions. Use of procedural arithmetic knowledge, including transformative rules like “minus a negative is plus a positive,” may also differ by operand sign. Here, we examined whether the activity evoked in negative number arithmetic was similar to that seen in positive problems, using region of interest analyses (ROIs) to examine a specific set of brain regions. Negative‐operand problems demonstrated a positive‐like effect of operation in the inferior parietal lobule with more activity for subtraction than addition, as well as increased activity across operation. Interestingly, while positive‐operand problems demonstrated the expected addition > subtraction activity difference in the angular gyrus, negative problems showed a reversed effect, with relatively more activity for subtraction than addition. Negative subtraction problems may be understood after translation to addition via rule, thereby invoking more addition‐like activity. Whole‐brain analyses showed increased right caudate activity for negative‐operand problems across operation, indicating a possible overall increase in usage of procedural rules. Arithmetic with negative numbers may thus shows some operation–activity relationships similar to positive numbers, but may also be affected by strategy. This study examines the flexibility of the mental number system by exploring to what degree the processing of an applied usage of a difficult, abstract mathematical concept is similar to that for positive numbers. Hum Brain Mapp 35:539–551, 2014. © 2012 Wiley Periodicals, Inc.
Dissociable dorsal and ventral frontostriatal working memory circuits: Evidence from subthalamic stimulation in Parkinson's disease
Authors: Ventre‐Dominey Jocelyne , Bourret Stéphanie , Mollion Hélène , Broussolle Emmanuel , Dominey Peter Ford
Published: October 2012

In this study, we investigated the neural substrates involved in visual working memory (WM) and the resulting effects of subthalamic nucleus (STN) stimulation in Parkinson's disease (PD). Cerebral activation revealed by positron emission tomography was compared among Parkinson patients with (PD‐ON) or without (PD‐OFF) STN stimulation, and a group of control subjects (CT) in two visual WM tasks with spatial (SP) and nonspatial (NSP) components. PD‐OFF patients displayed significant reaction time (RT) deficits for both memory tasks. Although there were no significant differences in RT between patients with PD‐ON and ‐OFF stimulation, patients with PD‐ON stimulation performed comparably to controls. The memory tasks were executed with normal error rates in PD‐ON and ‐OFF stimulation. In contrast to these behavioral results, whether the corresponding prefrontal activation was differentially affected by deep brain stimulation status in patients depended on whether the WM modality was SP versus NSP. Thus, SP WM was associated with (1) abnormal reduction in dorsolateral prefrontal activity in PD‐OFF and ‐ON stimulation and (2) abnormal overactivation in parieto‐temporal cortex in PD‐OFF and in limbic circuits in PD‐ON stimulation. In NSP WM, normal activation of the ventral prefrontal cortex was restored in PD‐ON stimulation. In both visual modalities the posterior cerebral regions including fusiform cortex and cerebellum, displayed abnormally reduced activity in PD. These results indicate that PD induces a prefrontal hypoactivation that STN stimulation can partially restore in a modality selective manner by additional recruitment of limbic structures in SP WM or by recovery of the ventral prefrontal activation in NSP WM. Hum Brain Mapp 35:552–566, 2014. © 2012 Wiley Periodicals, Inc.