bluuebunny/crossref_metadata_2025 huggingface dataset:
Pneumatic transport of granular materials with electrostatic effects
Authors: Lim Eldin Wee Chuan , Yao Jun , Zhao Yanlin
Published: March 2011

The methodology of coupling large eddy simulation (LES) with the discrete element method was applied for computational studies of pneumatic transport of granular materials through vertical and horizontal pipes in the presence of electrostatic effects. The LES numerical results obtained agreed well with the law of the wall for various y+‐ranges. The simulations showed that a thin layer of particles formed and remained adhered to the pipe walls during the pneumatic conveying process due to the effects of strong electrostatic forces of attraction toward the pipe walls. Particle concentrations were generally higher near the pipe walls than at the pipe center resulting in the ring flow pattern observed in previous experimental studies. The close correspondence between particle velocity vectors and fluid drag force vectors was indicative of the importance of fluid drag forces in influencing particle behaviors. In contrast, the much weaker particle–particle electrostatic repulsion forces had negligible effects on particle behaviors within the system under all operating conditions considered. The electrostatic field strength developed during pneumatic conveying increased with decreasing flow rate due to increased amount of particle‐wall collisions. Based on dynamic analyses of forces acting on individual particles, it may be concluded that electrostatic effects played a dominant role in influencing particle behaviors during pneumatic conveying at low flow rates, whereas drag forces became more important at high flow rates. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Restless legs syndrome‐associated MEIS1 risk variant influences iron homeostasis
Authors: Catoire Hélène , Dion Patrick A. , Xiong Lan , Amari Mourabit , Gaudet Rebecca , Girard Simon L. , Noreau Anne , Gaspar Claudia , Turecki Gustavo , Montplaisir Jacques Y. , Parker J. Alex , Rouleau Guy A.
Published: March 2011

Restless legs syndrome (RLS) is a frequent sleep disorder that is linked to disturbed iron homeostasis. Genetic studies identified MEIS1 as an RLS‐predisposing gene, where the RLS risk haplotype is associated with decreased MEIS1 mRNA and protein expression. We show here that RNA interference treatment of the MEIS1 worm orthologue increases ferritin expression in Caenorhabditis elegans and that the RLS‐associated haplotype leads to increased expression of ferritin and DMT1 in RLS brain tissues. Additionally, human cells cultured under iron‐deficient conditions show reduced MEIS1 expression. Our data establish a link between the RLS MEIS1 gene and iron metabolism. Ann Neurol 2011;
Self‐condensing atom transfer radical polymerization of inimers of different reactivity ratios with styrene and the thermal properties of poly(2,6‐dimethyl‐1, 4‐phenylene oxide)/branched polystyrene blends
Authors: Zhai Guangqun , Li Chun , Fang Yan , Jiang Bibiao , Jin Chao , Song Hongmei
Published: March 2011

Although the self‐condensing atom transfer radical polymerization (SCATRP) of inimers with typical comonomers has been extensively performed, there have been few reports to correlate the reactivity ratio with the growth of the molecular weights (MWs) and the development of branched structures. Thus, the SCATRP of inimers of different reactivity ratios, namely, 4‐chloromethylstyrene (CMS) and maleimide (MI) inimers, with a large excess of styrene (St) were carried out, respectively, to examine the effect. The conversion and MW were monitored by gas chromatography, gel permeation chromatography, and multiangle laser light scattering. The results suggested that CMS merely functioned as an initiator for St at the early stage; this led to linear macroinimers, which underwent SCATRP and gave rise to randomly branched polystyrene (PS) only at high conversion. The MI inimers formed charge‐transfer complexes with St and underwent the SCATRP to result in hyperbranched copolymers at first; this initiated the atom transfer radical polymerization of St and led to star‐shaped PS. With the objective of improving the processability and melt fluidity, the physical properties of poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO) blends with linear, randomly branched, and star‐shaped PS were compared. In comparison with those with linear PS, the PPO/branched PS blends exhibited a higher glass‐transition temperature, a higher melt flow index, and a comparable thermal stability because of the spherical architecture of the branched PS. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Dynamic mechanical properties of polystyrene‐block‐poly[ethylene‐co‐(ethylene‐propylene)]‐block‐polystyrene triblock copolymer/hydrocarbon oil blends
Authors: Nishioka Akihiro , Aoki Yuji , Suzuki Takaya , Ishigami Akira , Endo Tomohiro , Koda Tomonori , Koyama Kiyohito
Published: March 2011

Blend systems of polystyrene‐block‐poly(ethylene‐co‐(ethylene‐propylene))‐block‐polystyrene (SEEPS) triblock copolymer with three types of hydrocarbon oil of different molecular weight were prepared. The E″ curves as a function of temperature exhibited two peaks; one peak at low temperature (≅ −50°C), arising from the glass transition of the poly[ethylene‐co‐(ethylene‐propylene)] (PEEP) phase and a high temperature peak (≅ 100°C), arising from the glass transition of the polystyrene (PS) phase. The glass transition temperature (Tg) of the PEEP phase shifted to lower temperature with increasing oil content. The shifted Tg depended on the types of oil and was lower for the low molecular weight oil. The Tg of PS phase of the present blend system, were found to be constant and independent of the oil content, when molecular weight of the oil is high. However, for the lower molecular weight oil, the Tg of the PS phase also shifted to lower temperatures. This fact indicates that the oil of high molecular weight is merely dissolved in the PS phase. The E′ at (75°C, at which temperature both of PEEP and PS phases are in glassy state, was found to be independent of oil content. In contrast, at 25°C, at which temperature the PEEP phase is in rubbery state, the E′ decreased sharply with increasing oil content. This result indicates that the hydrocarbon oil was a selective solvent in the PEEP phase. It mainly dissolved in the PEEP phase, although slightly dissolved into the PS phase as well, when molecular weight of oil is low. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The influence of POSS substituent on synthesis and properties of hybrid materials based on urethane dimethacrylate (UDMA) and various polyhedral oligomeric silsesquioxane (POSS)
Authors: Lungu A. , Şulcă N. M. , Vasile E. , Badea N. , Pârvu C. , Iovu H.
Published: March 2011

DSC was used to follow the degree of conversion (DC) for the methacrylic groups in the case of some hybrid systems based on urethane dimethacrylate (UDMA) monomer and various polyhedral oligomeric silsesquioxane (POSS) structures (HISO‐POSS, CPENTYL‐POSS, and MA‐POSS). The chemical structure of the POSS compound directly influences the DC value. The conversion of the methacrylic groups from the hybrid composites after thermal curing was determined by measuring the residual heat of reaction. Both SEM and AFM techniques were additionally used to performed an advanced morphological characterization for the obtained POSS‐nanocomposites. The DSC data have been corroborated with those resulted from the NIR spectroscopy. The introduction of POSS compound within the UDMA matrix leads to a decrease of the hybrid material transparency due to the formation of agglomerates also pointed out by SEM analysis. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Nanofibrous scaffold prepared by electrospinning of poly(vinyl alcohol)/gelatin aqueous solutions
Authors: Yang Chao , Wu Xiaomian , Zhao Yinghui , Xu Ling , Wei Shicheng
Published: March 2011

A series of nanofibrous scaffolds were prepared by electrospinning of poly(vinyl alcohol) (PVA)/gelatin aqueous solution. PVA and gelatin was dissolved in pure water and blended in full range, then being electrospun to prepared nanofibers, followed by being crosslinked with glutaraldehyde vapor and heat treatment to form nanofibrous scaffold. Field emission scanning electron microscope (FESEM) images of the nanofibers manifested that the fiber average diameters decreased from 290 to 90 nm with the increasing of gelatin. In vitro degradation rates of the nanofibers were also correlated with the composition and physical properties of electrospinning solutions. Cytocompatibility of the scaffolds was evaluated by cells morphology and MTT assay. The FESEM images revealed that NIH 3T3 fibroblasts spread and elongated actively on the scaffolds with spindle‐like and star‐type shape. The results of cell attachment and proliferation on the nanofibrous scaffolds suggested that the cytotoxicity of all samples are grade 1 or grade 0, indicating that the material had sound biosafety as biomaterials. Compared with pure PVA and gelatin scaffolds, the hybrid ones possess improved biocompatibility and controllability. These results indicate that the PVA/gelatin nanofibrous have potential as skin scaffolds or wound dressing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Is European catfish a threat to eels in southern France?
Authors: Martino Aurelia , Syväranta Jari , Crivelli Alain , Cereghino Regis , Santoul Frederic
Published: March 2011

European eel (Anguilla anguilla) is recognized as a critically endangered species in the northern hemisphere. Threats such as overfishing or pollution are well known as risks for eel populations. However, much less is known about the impact of introduced fish on European eels. In particular, introduced large‐bodied predators could become new predators to eels.

The potential impact of European catfish (Silurus glanis L) on an eel population in the Camargue, southern France was studied using a combination of stable isotope and gut content analyses.

Only large‐bodied catfish (>500 mm) can consume numerous fish prey. However, catfish mostly consumed crayfish (Procambarus clarkii), these prey items being found in 79% of the guts of the largest individuals. Eel was absent from the dissected catfish guts. A mixing model based on Bayesian inference revealed that catfish diet included only 5% (0–8.5%) of marine sources (both eel and mullet).

While local economic interests prompted ecological studies to assess whether catfish exerted a new and strong predatory pressure on eel, this study found that European catfish behaved as an opportunistic omnivore, and as such was not a direct threat as a predator on eel populations in the Camargue. Copyright © 2011 John Wiley & Sons, Ltd.
Venous and arterial thromboembolic events in adalimumab‐treated patients with antiadalimumab antibodies: A case series and cohort study
Authors: Korswagen L. A. , Bartelds G. M. , Krieckaert C. L. M. , Turkstra F. , Nurmohamed M. T. , van Schaardenburg D. , Wijbrandts C. A. , Tak P. P. , Lems W. F. , Dijkmans B. A. C. , van Vugt R. M. , Wolbink G. J.
Published: March 2011

Objective

We observed 3 patients who developed severe venous and arterial thromboembolic events during treatment with adalimumab, 2 of whom had rheumatoid arthritis (RA) and 1 of whom had psoriatic arthritis. Antiadalimumab antibodies were detected in all 3 patients. We undertook this study to determine whether the development of antiadalimumab antibodies was associated with thromboembolic events during adalimumab treatment.

Methods

A retrospective search (with blinding with regard to antiadalimumab antibody status) for thromboembolic events was performed in a prospective cohort of 272 consecutively included adalimumab‐treated RA patients. Incidence rates were calculated and hazard ratios (HRs) were estimated using Cox regression. None of the index patients were part of the cohort.

Results

Antiadalimumab antibodies were detected in 76 of 272 patients (28%). Eight thromboembolic events were found, 4 of which had occurred in patients with antiadalimumab antibodies. The incidence rate was 26.9/1,000 person‐years for patients with antiadalimumab antibodies and 8.4/1,000 person‐years for patients without those antibodies (HR 3.8 [95% confidence interval 0.9–15.3], P = 0.064). After adjustment for duration of followup, age, body mass index, erythrocyte sedimentation rate, and prior thromboembolic events, the HR was 7.6 (95% confidence interval 1.3–45.1) (P = 0.025).

Conclusion

These findings suggest that the occurrence of venous and arterial thromboembolic events during adalimumab treatment is higher in patients with antiadalimumab antibodies than in those without antiadalimumab antibodies. Patient numbers were relatively small; therefore, validation in other cohorts is mandatory.
Fracture risk before and after total hip replacement in patients with osteoarthritis: Potential benefits of bisphosphonate use
Authors: Prieto‐Alhambra Daniel , Javaid M. Kassim , Judge Andrew , Maskell Joe , Kiran Amit , de Vries Frank , Cooper Cyrus , Arden Nigel K.
Published: March 2011

Objective

The association between osteoarthritis (OA) and fractures remains unclear. OA patients have increased bone mass, but no corresponding decrease in fracture rate. This study was undertaken to determine the fracture rates in patients with hip OA undergoing a total hip replacement (THR), as compared with disease‐free controls, and to assess the association between bisphosphonate use and postsurgery fracture risk.

Methods

We conducted a population‐based parallel‐cohorts study. All patients in the UK General Practice Research Database undergoing a THR for hip OA between 1986 and 2006 constituted the exposed cohort (n = 14,133). Five disease‐free controls were matched with each patient by age, sex, and practice site. Subjects were followed up for 5 years before and after surgery. Fracture rates and rate ratios (RRs) were estimated using Poisson regression. In addition, bisphosphonate use was identified among patients undergoing THR, and the data, stratified by the presence or absence of a previous fracture and by treatment propensity score, were assessed using fitted Cox models to study the effect of bisphosphonate use on the risk of fracture postsurgery.

Results

Patients undergoing a THR had a similar fracture risk as that in controls in the 5 years before THR, but had higher rates postsurgery, which peaked at years 2.5–5 (adjusted RR 1.24, 95% confidence interval [95% CI] 1.02–1.52). Use of bisphosphonates lowered the fracture risk among THR patients who received bisphosphonates as primary prevention (hazard ratio [HR] 0.56, 95% CI 0.38–0.82) and also among THR patients who had experienced a previous osteoporotic fracture (HR 0.48, 95% CI 0.23–0.99).

Conclusion

This study identified a 25% increase in fracture risk at 2.5–5 years postsurgery among patients undergoing a THR. Bisphosphonate use reduced the post‐THR risk of fracture when administered both as primary prevention and as secondary prevention, by 44% and 52%, respectively. This must be further confirmed in randomized controlled trials.
Polymer‐based microparticles in tissue engineering and regenerative medicine
Authors: Oliveira Mariana B. , Mano João F.
Published: March 2011

Different types of biomaterials, processed into different shapes, have been proposed as temporary support for cells in tissue engineering (TE) strategies. The manufacturing methods used in the production of particles in drug delivery strategies have been adapted for the development of microparticles in the fields of TE and regenerative medicine (RM). Microparticles have been applied as building blocks and matrices for the delivery of soluble factors, aiming for the construction of TE scaffolds, either by fusion giving rise to porous scaffolds or as injectable systems for in situ scaffold formation, avoiding complicated surgery procedures. More recently, organ printing strategies have been developed by the fusion of hydrogel particles with encapsulated cells, aiming the production of organs in in vitro conditions. Mesoscale self‐assembly of hydrogel microblocks and the use of leachable particles in three‐dimensional (3D) layer‐by‐layer (LbL) techniques have been suggested as well in recent works. Along with innovative applications, new perspectives are open for the use of these versatile structures, and different directions can still be followed to use all the potential that such systems can bring. This review focuses on polymeric microparticle processing techniques and overviews several examples and general concepts related to the use of these systems in TE and RE applications. The use of materials in the development of microparticles from research to clinical applications is also discussed. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Role of Endonucleases XPF and XPG in Nucleotide Excision Repair of Platinated DNA and Cisplatin/Oxaliplatin Cytotoxicity
Authors: Graf Nora , Ang Wee Han , Zhu Guangyu , Myint MyatNoeZin , Lippard Stephen J.
Published: March 2011

Resistance of tumor cells to platinum anticancer agents poses a major problem in cancer chemotherapy. One of the mechanisms associated with platinum‐based drug resistance is the enhanced capacity of the cell to carry out nucleotide excision repair (NER) on platinum‐damaged DNA. Endonucleases XPF and XPG are critical components of NER, responsible for excising the damaged DNA strand to remove the DNA lesion. Here, we investigated possible consequences of down‐regulation of XPF and XPG gene expression in osteosarcoma cancer cells (U2OS) and the impact on cellular transcription and DNA repair. We further evaluated the sensitivity of such cells toward the platinum anticancer drugs cisplatin and oxaliplatin.
A novel technique for stenting pulmonary artery and conduit bifurcation stenosis
Authors: Stumper Oliver , Bhole Vinay , Anderson Ben , Reinhardt Zdenka , Noonan Patrick , Mehta Chetan
Published: March 2011

Background: Distal conduit obstruction is a recognized complication after surgery for congenital heart disease requiring implantation of a conduit from the right ventricle to the pulmonary arteries. Endovascular stenting of distal conduit obstruction can be challenging due to the proximity to the pulmonary artery bifurcation. Objective: A technique is described, whereby a single stent is mounted onto two balloon angioplasty catheters in tandem. This ensemble was delivered to the distal conduit/pulmonary artery via a large Mullins sheath on two guidewires, one placed in each of the branch pulmonary arteries. The aim was to assess safety and efficacy of this novel technique. Materials and Results: Seven patients (mean age 13.4 (6.7–23.4) years, mean weight 44.2 (23–69) kg were treated with this method. The pressure gradient was reduced from 36 (26–52) mm Hg to 11 (8–15) mm Hg [P< 0.05]. RV/LV pressure ratio decreased from 0.85 (0.6–0.95) to 0.42 (0.35–0.5) [P < 0.05]. There were no significant complications. During follow‐up over a median of 2.6 (0.3–6.7) years no patient required re‐intervention or surgery. Conclusion: This novel technique appears to be safe and effective for stenting stenoses just proximal to pulmonary artery bifurcation. © 2011 Wiley‐Liss, Inc.
Estimating the reversing and non‐reversing heat flow from standard DSC curves in the glass transition region
Authors: Artiaga Ramón , López‐Beceiro Jorge , Tarrío‐Saavedra Javier , Gracia‐Fernández Carlos , Naya Salvador , Mier José L.
Published: March 2011

A mathematical model for the total heat flow obtained in differential scanning calorimetry (DSC) experiments from polymers with enthalpic relaxation is proposed. It is limited to the glass transition and enthalpic relaxation range of temperature and to the cases where the enthalpic relaxation is the only non‐reversing process taking place. The model consists of a mixture of functions representing the heat capacity heat flow of the glassy and non‐glassy fractions, the glass transition progress and the enthalpic relaxation heat flow.

Optimal fittings of the model were performed on the experimental total heat flow data, obtained from two thermoplastics with different aging times. Considering which functions of the mixture represent reversing and non‐reversing processes, the reversing and non‐reversing heat flows were also estimated. The estimated reversing and non‐reversing signals were compared with the ones obtained by modulation. On the whole a good match was found, which was even better considering that the estimates are not affected by the frequency effect of the modulated temperature DSC (MTDSC) measurements. The model assumes linear trends for the heat capacity heat flow of the glassy and non‐glassy structures. The glass transition progress is represented by a generalized logistic function and the enthalpic relaxation heat flow by the first derivative of another generalized logistic. It brings about a new approach to these phenomena, where the parameters of these functions represent the temperature at which each event is centered, the change of heat capacity (Cp) at the glass transition and the energy involved in the enthalpic recovery. Copyright © 2011 John Wiley & Sons, Ltd.
Catalytic Photooxidation of Alcohols by an Unsymmetrical Tetra(pyridyl)pyrazine‐Bridged Dinuclear Ru Complex
Authors: Chen Weizhong , Rein Francisca N. , Scott Brian L. , Rocha Reginaldo C.
Published: March 2011

The dinuclear complexes [(tpy)Ru(tppz)Ru(bpy)(L)]n+ (where L is Cl− or H2O, tpy and bpy are the terminal ligands 2,2′:6′,2′′‐terpyridine and 2,2′‐bipyridine, and tppz is the bridging backbone 2,3,5,6‐tetrakis(2‐pyridyl)pyrazine) were prepared and structurally and electronically characterized. The mononuclear complexes [(tpy)Ru(tppz)]2+ and [(tppz)Ru(bpy)(L)]m+ were also prepared and studied for comparison. The proton‐coupled, multi‐electron photooxidation reactivity of the aquo dinuclear species was shown through the photocatalytic dehydrogenation of a series of primary and secondary alcohols. Under simulated solar irradiation and in the presence of a sacrificial electron acceptor, the photoactivated chromophore–catalyst complex (in aqueous solutions at room temperature and ambient pressure conditions) can perform the visible‐light‐driven conversion of aliphatic and benzylic alcohols into the corresponding carbonyl products (i.e., aldehydes or ketones) with 100 % product selectivity and several tens of turnover cycles, as probed by NMR spectroscopy and gas chromatography. Moreover, for aliphatic substrates, the activity of the photocatalyst was found to be highly selective toward secondary alcohols, with no significant product formed from primary alcohols. Comparison of the activity of this tppz‐bridged complex with that of the analogue containing a back‐to‐back terpyridine bridge (tpytpy, i.e., 6′,6′′‐bis(2‐pyridyl)‐2,2′:4′,4′′:2′′,2′′′‐quaterpyridine) demonstrated that the latter is a superior photocatalyst toward the oxidation of alcohols. The much stronger electronic coupling with significant delocalization across the strongly electron‐accepting tppz bridge facilitates charge trapping between the chromophore and catalyst centers and therefore is presumably responsible for the decreased catalytic performance.
Performance of hydrocyclones with different geometries
Authors: Vieira Luiz G. M. , Silvério Beatriz C. , Damasceno João J. R. , Barrozo Marcos A. S.
Published: March 2011

Hydrocyclones belong to an important group of equipments designed to solid–liquid or liquid–liquid separation in a centrifugal field. It is possible to adapt a hydrocyclone to the accomplishment of several industrial activities depending on the geometrical relations among its main dimensions. The operation and design of these devices are relatively simple; however, the flow inside them is very complex and its prediction is very difficult. For that reason, most models that are used to predict hydrocyclone performance are empirical ones. The objective of this work was to study the influence of geometric variables in the performance of hydrocyclones, using CFD and response surface techniques. The obtained results show that it was possible to find an optimum hydrocyclone design, that is, geometric relationships that lead to Euler number and cut size in minimum levels.
The extraction of lactic acid by emulsion type of liquid membranes using alamine 336 in escaid 100
Authors: Manzak Aynur , Tutkun Osman
Published: March 2011

The extraction of lactic acid from aqueous solutions through an emulsion liquid membrane containing Alamine 336 as carrier was investigated. The influence of mixing speed, diluent type, surfactant concentration, extractant concentration, feed solution pH, stripping concentration, phase ratio, and feed concentration were examined. Liquid membrane consists of a diluent (n‐heptane, toluene, kerosene, Escaid 100, and Escaid 200), a surfactant (Span 80) and an extractant (Alamine 336), and Na2CO3were used as a stripping solution. It is possible to extract 91% of lactic acid from aqueous solutions using Alamine 336 in Escaid 100, as an extractant and a diluent respectively.
Validation of the lymph node ratio as a prognostic factor in patients with N1 nonsmall cell lung cancer
Authors: Jonnalagadda Sirisha , Arcinega Jacqueline , Smith Cardinale , Wisnivesky Juan P.
Published: March 2011

BACKGROUND:

The number of positive lymph nodes (LNs) has been proposed as a prognostic indicator in N1 nonsmall cell lung cancer (NSCLC). However, the number of positive LNs is confounded by the number of LNs resected during surgery. The lymph node ratio (LNR) (the ratio of the number of positive LNs divided by the number of LNs resected) can circumvent this limitation. The prognostic significance of the LNR has been demonstrated in elderly patients with NSCLC. The objective of the current study was to evaluate whether a higher LNR is a marker of worse survival in patients with NSCLC aged ≤65 years who have N1 disease.

METHODS:

The Surveillance, Epidemiology, and End Results database was used to identify 4004 patients who underwent resection for N1 NSCLC. Patients were classified into 3 groups according to LNR (≤0.15, 0.16‐0.5, and >0.5). Associations of the LNR with lung cancer‐specific and overall mortality were evaluated using the Kaplan‐Meier method. Stratified and Cox regression analyses were used to assess correlations between the LNR and survival after adjusting for other prognostic factors.

RESULTS:

Unadjusted analysis indicated that a higher LNR was associated with worse lung cancer‐specific survival (P < .0001) and overall survival (P < .0001). Stratified and multivariate analyses also indicated that the LNR was an independent predictor of survival after controlling for potential confounders.

CONCLUSIONS:

The current results confirmed that the LNR is an independent prognostic factor for survival in patients with N1 NSCLC. This information may be used to identify patients who are at greater risk of cancer recurrence. Cancer 2011;. © 2011 American Cancer Society.
Characterization of NPY Y2 receptor protein expression in the mouse brain. II. Coexistence with NPY, the Y1 receptor, and other neurotransmitter‐related molecules
Authors: Stanić Davor , Mulder Jan , Watanabe Masahiko , Hökfelt Tomas
Published: March 2011

Neuropeptide Y (NPY) is widely expressed in the brain and its biological effects are mediated through a variety of receptors. We examined, using immunohistochemistry, expression of the Y2 receptor (R) protein in the adult mouse brain and its association with NPY and the Y1R, as well as a range of additional neurotransmitters and signaling‐related molecules, which previously have not been defined. Our main focus was on the hippocampal formation (HiFo), amygdaloid complex, and hypothalamus, considering the known functions of NPY and the wide expression of NPY, Y1R, and Y2R in these regions. Y2R‐like immunoreactivity (‐LI) was distributed in nerve fibers/terminal endings throughout the brain axis, without apparent colocalization with NPY or the Y1R. Occasional coexistence between NPY‐ and Y1R‐LI was found in the HiFo. Following colchicine treatment, Y2R‐LI accumulated in cell bodies that coexpressed γ‐aminobutyric acid (GABA) in a population of cells in the amygdaloid complex and lateral septal nucleus, but not in the HiFo. Instead, Y2R‐positive nerve terminals appeared to surround GABA‐immunoreactive (ir) cells in the HiFo and other neuronal populations, e.g., NPY‐ir cells in HiFo and tyrosine hydroxylase‐ir cells in the hypothalamus. In the HiFo, Y2R‐ir mossy fibers coexpressed GABA, glutamic acid decarboxylase 67 and calbindin, and Y2R‐LI was found in the same fibers that contained the presynaptic metabotropic glutamate receptor 2, but not together with any of the three vesicular glutamate transporters. Our findings provide further support that Y2R is mostly presynaptic, and that Y2Rs thus have a modulatory role in mediating presynaptic neurotransmitter release. J. Comp. Neurol. 519:1219–1257, 2011. © 2011 Wiley‐Liss, Inc.
VLSI implementation of a configurable IP Core for quantized discrete cosine and integer transforms
Authors: Sun Chi‐Chia , Donner Philipp , Götze Jürgen
Published: March 2011

In this paper, a low‐complexity and highly integrated IP Core for image/video transformations is presented. It can perform quantized 8×8 DCT and quantized 8 × 8/4 × 4 H.264 integer transforms on the presented configurable architecture using integer shift–add arithmetic operations. The MPEG‐4/H.264 experimental and circuit simulation results show that the reconfigurable modules and the CORDIC‐Scaler can not only approximate the arbitrary scaling values for different video standards efficiently but also achieve very high throughput and retain good transformation quality compared with the default methods in terms of PSNR. Therefore, the proposed IP Core is very suitable for low‐complexity multi‐purpose Video Codecs in SoC designs. Copyright © 2011 John Wiley & Sons, Ltd.
A joint experimental and simulation study of the IEEE 802.11s HWMP protocol and airtime link metric
Authors: Garroppo Rosario G. , Giordano Stefano , Tavanti Luca
Published: March 2011

One of the main features of the upcoming IEEE 802.11s standard is the path selection procedure, which is performed by the Hybrid Wireless Mesh Protocol by means of thetextitairtime link metric (ALM). Through a small experimental testbed, and using the open80211s code, which provides one of the most compliant draft implementations, we analysed the impact that the implementation choices of the developers have on the system performance. The analysis revealed that even small deviations from the specified routines (or different choices in the estimation of the parameters used in the online calculation of the ALM) can lead to noteworthy performance degradations. We thus realized some fixes to improve the performance of the system and verified the effectiveness of such amendments in a realistic simulation environment. We then compared the performance of the modified version to the original one. The outcome of the test highlighted the remarkable advantage achieved by the proposed fixes. Copyright © 2011 John Wiley & Sons, Ltd.
Structural Effects of Varied Steric Bulk in 2,(4),6‐Substituted Dimethylthallium(III) Phenoxides
Authors: Briand Glen G. , Decken Andreas , McKelvey J. Ian , Zhou Yukun
Published: March 2011

The structural effects of varied steric bulk on 2,(4),6‐substituted dimethylthallium(III) phenoxides has been examined. The facile reaction of Me3Tl with a series of 2,(4),6‐substituted phenols in toluene or diethyl ether resulted in the formation of the species [Me2TlO(2,6‐R2C6H3)]2 [R = H (4), Me (5), iPr (6), Ph (7)] and [Me2TlO(2,4,6‐tBu3C6H2)] (8). All compounds have been characterized by elemental analysis as well as their melting point; FTIR, FT‐Raman, solution 1H and 13C{1H} NMR spectroscopy; and X‐ray crystallography. The structures of 4–7 are dimeric through short intermolecular Tl–O interactions, which yield a symmetric Tl2O2 unit and a distorted seesaw C2O2 bonding environment for thallium. An increase in the steric bulk in 4–6 has little effect on Tl–O bond lengths, whereas the CMe–Tl–CMe bond angle was found to significantly decrease. Further, the phenoxide ligands in 5 and 6 were found to be oriented perpendicular to the Tl2O2 unit to minimize steric interactions. Alternatively, compound 7 shows an increase in Tl–O bond lengths and an increase in the CMe–Tl–CMe bond angle compared to 4–6, and orientation of the phenoxide ligands perpendicular to the Tl2O2 core. The significant steric bulk imposed by the –O(2,4,6‐tBu3C6H2) ligand in 8 precludes dimer formation and allows for isolation of a monomeric species that contains a three‐coordinate T‐shaped C2O bonding environment for thallium. DFT calculations show that the energetic favorability of dimer formation decreases with increased phenoxide steric bulk.
Samarium Iodobinaphtholate: An Efficient Catalyst for Enantioselective Aza‐Michael Additions of O‐Benzylhydroxylamine to N‐Alkenoyloxazolidinones
Authors: Didier Dorian , Meddour Abdelkrim , Bezzenine‐Lafollée Sophie , Collin Jacqueline
Published: March 2011

Samarium diiodide is an efficient catalyst for the aza‐Michael addition of O‐benzylhydroxylamine to α,β‐unsaturated N‐acyloxazolidinones leading to mixtures of the Michael adduct and the product resulting from its amidation. Samarium iodobinaphtholate catalyzed reactions selectively afford the Michael adducts with enantiomeric excesses up to 88 %. An isoinversion effect with temperature is observed with the highest enantiomeric excess at –40 °C.
Use of Acylhydrazine‐ and Acylhydrazone‐Type Ligands to Promote CuI‐Catalyzed C–N Cross‐Coupling Reactions of Aryl Bromides with N‐Heterocycles
Authors: Li Liuyi , Zhu Lei , Chen Dagui , Hu Xuelei , Wang Ruihu
Published: March 2011

A series of ten acylhydrazine‐ and acylhydrazone‐type ligands were designed and synthesized. Their electronic and steric properties were easily modified and tuned by varying the substituents in the vicinity of the acylhydrazine and acylhydrazone units. The effect of ligands on the catalytic activity of Ullmann reactions was assessed by using a combination of these ligands with CuI. The catalytic system is very efficient for the C–N coupling reaction of azoles with aryl and heteroaryl bromides.
Electromembrane extraction of heavy metal cations followed by capillary electrophoresis with capacitively coupled contactless conductivity detection
Authors: Kubáň Pavel , Strieglerová Lenka , Gebauer Petr , Boček Petr
Published: March 2011

Electromembrane extraction (EME) was used as an off‐line sample pre‐treatment method for the determination of heavy metal cations in aqueous samples using CE with capacitively coupled contactless conductivity detection (CE‐C4D). A short segment of porous polypropylene hollow fibre was penetrated with 1‐octanol and 0.5% v/v bis(2‐ethylhexyl)phosphonic acid and constituted a low cost, single use, disposable supported liquid membrane, which selectively transported and pre‐concentrated heavy metal cations into the fibre lumen filled with 100 mM acetic acid acceptor solution. Donor solutions were standard solutions and real samples dissolved in deionized water at neutral pH. At optimized EME conditions (penetration time, 5 s; applied voltage, 75 V; and stirring rate, 750 rpm), 15–42% recoveries of heavy metal cations were achieved for a 5 min extraction time. Repeatability of the EME pre‐treatment was examined for six independent EME runs and ranged from 6.6 to 11.1%. Limits of detection for the EME‐CE‐C4D method ranged from 25 to 200 nM, resulting into one to two orders of magnitude improvement compared with CE‐C4D without sample treatment. The developed EME sample pre‐treatment procedure was applied to the analysis of heavy metal cations in tap water and powdered milk samples. Zinc in the real samples was identified and quantified in a background electrolyte solution consisting of 20 mM L‐histidine and 30 mM acetic acid at pH 4.95 in about 3 min.
Analysis of proteins in biological samples by capillary sieving electrophoresis with postcolumn derivatization/laser‐induced fluorescence detection
Authors: Kaneta Takashi , Ogura Takehito , Imasaka Totaro
Published: March 2011

Previously, we have demonstrated postcolumn derivatization of proteins separated by capillary sieving electrophoresis (CSE), in which naphthalene‐2,3‐dicarbaldehyde was employed as a fluorogenic labeling reagent. Standard proteins separated by CSE were reacted with naphthalene‐2,3‐dicarbaldehyde in the presence of 2‐mercaptoethanol (2‐ME) which plays a role of a reducing agent in the derivatization reaction. To improve the sensitivity, we attempted the use of ethanethiol instead of 2‐ME. Ethanethiol showed 1.4‐ to 4.5‐fold lower limits of detection for proteins than 2‐ME. Furthermore, we found that 8‐aminopyrene‐1,3,6‐trisulfonate (APTS) is a good marker for relative electrophoretic mobilities of proteins in CSE. Since APTS is a fluorescent and trivalent anion, it generates strong fluorescence and migrates faster than any of the proteins. Therefore, we employed APTS as a marker to obtain the relative electrophoretic mobilities of proteins. The present method was applied to the analyses of proteins in biological samples. Human Ewing's family tumor cell line ‘RDES’ was used as a sample. The cultured cells were lysed with a buffer containing Tris‐HCl, NaCl, sodium dodecyl sulfate, and 2‐ME. After denaturation, the lysate was directly introduced into the capillary. Several peaks, which would correspond to proteins with molecular mass ranging from 10 to 93 kDa, were found in the cell lysate. In addition, we measured a milk sample by the CSE with postcolumn derivatization. The electropherogram showed five major peaks which corresponded to α‐lactalbumin, β‐lactoglobulin, κ‐casein, bovine serum albumin, and mixture of α‐ and β‐casein.
Thermal marks as a signal processing aid for a portable capillary electropherograph
Authors: Seiman Andrus , Vaher Merike , Kaljurand Mihkel
Published: March 2011

The interpretation of raw signals in capillary CE can be challenging if there are unknown peaks, or the signal is corrupt due to baseline fluctuations, EOF velocity drift, etc. Signal processing could be required before results can be interpreted. A suite of signal processing algorithms has been developed for CE data analysis, specifically for use in field experiments for the detection of nerve agents using portable CE instruments. Everything from baseline correction and electropherogram alignment to peak matching and identification is included in these programs. Baseline correction is achieved by interpolating a new baseline according to points found using all local extremes, by applying an appropriate outliers test. Irreproducible migration times are corrected by compensating for EOF drift, measured with the aid of thermal marks. Thermal marks are small disturbances in the capillary created by punctual heating that move with the velocity of EOF. Peaks in the sample electropherogram are identified using a fuzzy matching algorithm, by comparing peaks from the sample electropherogram to peaks from a reference electropherogram.
A method to determine quasi‐steady state in constant voltage mode isotachophoresis
Authors: Shim Jaesool , Cho Migyung , Dutta Prashanta
Published: March 2011

Identification of the steady state is very challenging in isotachophoresis (ITP); especially in complex microgeometries, such as dog‐leg channels or cross‐channel junctions. In this work, an elastic matching method is applied to determine the quasi‐steady state in microscale ITP. In the elastic matching method, the similarity between two profiles is calculated by comparing intensity distribution of two images or profiles. To demonstrate this similarity‐based analysis technique for ITP, a constant voltage mode ITP model is developed and applied to a five‐component ITP system. Hydrochloric acid and caproic acid are used as the leader and terminator, respectively, while histidine is used as the counter‐ion. Two sample components, acetic acid and benzoic acid, are separated under the action of an applied electric field in both straight and dog‐leg microchannels. This analysis shows that conductivity profiles provide a better measure to determine the quasi‐steady state in an ITP process. For a straight microchannel, the quasi‐steady state is achieved in less than a minute with a total potential drop of 100 V in a 2 cm long channel. In a straight channel, a true steady state can be achieved for ITP with appropriate countercurrent flow where stationary zones are formed, but the time it takes to reach the steady state is much longer than the without counter flow case. The numerical results indicate that a steady state cannot be reached in a dog‐leg microchannel because of sample dispersion and refocusing at and near the intersections and at the branch channels. However, the elastic matching method can be used to determine the quasi‐steady state in a dog‐leg microchannel.
MHD squeezing flow of second‐grade fluid between two parallel disks
Authors: Hayat T. , Yousaf Arshia , Mustafa M. , Obaidat S.
Published: March 2011

This paper examines the unsteady two‐dimensional flow of a second‐grade fluid between parallel disks in the presence of an applied magnetic field. The continuity and momentum equations governing the unsteady two‐dimensional flow of a second‐grade fluid are reduced to a single differential equation through similarity transformations. The resulting differential system is computed by a homotopy analysis method. Graphical results are discussed for both suction and blowing cases. In addition, the derived results are compared with the homotopy perturbation solution in a viscous fluid (Math. Probl. Eng., DOI: 10.1155/2009/603916). Copyright © 2011 John Wiley & Sons, Ltd.
p19ARF/p14ARF controls oncogenic functions of signal transducer and activator of transcription 3 in hepatocellular carcinoma
Authors: Schneller Doris , Machat Georg , Sousek Alexandra , Proell Verena , van Zijl Franziska , Zulehner Gudrun , Huber Heidemarie , Mair Markus , Muellner Markus K. , Nijman Sebastian M.B. , Eferl Robert , Moriggl Richard , Mikulits Wolfgang
Published: March 2011

Abstract:

Signal transducer and activator of transcription 3 (Stat3) is activated in a variety of malignancies, including hepatocellular carcinoma (HCC). Activation of Ras occurs frequently at advanced stages of HCC by aberrant signaling through growth factor receptors or inactivation of effectors negatively regulating Ras signaling. Here, we addressed the role of Stat3 in Ras-dependent HCC progression in the presence and absence of p19ARF/p14ARF. We show that constitutive active (ca) Stat3 is tumor suppressive in Ras-transformed p19ARF−/− hepatocytes, whereas the expression of Stat3 lacking Tyr705 phosphorylation (U-Stat3) enhances tumor formation. Accordingly, Ras-transformed Stat3Δhc/p19ARF−/− hepatocytes (lacking Stat3 and p19ARF) showed increased tumor growth, compared to those expressing Stat3, demonstrating a tumor-suppressor activity of Stat3 in cells lacking p19ARF. Notably, endogenous expression of p19ARF in Ras-transformed hepatocytes conveyed oncogenic Stat3 functions, resulting in augmented or reduced HCC progression after the expression of caStat3 or U-Stat3, respectively. In accord with these data, the knockdown of p14ARF (the human homolog of p19ARF) in Hep3B cells was associated with reduced pY-Stat3 levels during tumor growth to circumvent the tumor-suppressive effect of Stat3. Inhibition of Janus kinases (Jaks) revealed that Jak causes pY-Stat3 activation independently of p14ARF levels, indicating that p14ARF controls the oncogenic function of pY-Stat3 downstream of Jak. Conclusion: These data show evidence that p19ARF/p14ARF determines the pro- or anti-oncogenic activity of U-Stat3 and pY-Stat3 in Ras-dependent HCC progression. (HEPATOLOGY 2011;)
Mesenchymal stem cells as vehicles for targeted delivery of anti‐angiogenic protein to solid tumors
Authors: Ghaedi Mahboobe , Soleimani Masoud , Taghvaie Narges Mohammad , Sheikhfatollahi Mahmood , Azadmanesh Keyhan , Lotfi Abbas S. , Wu Jian
Published: March 2011

Background

Inhibition of tumor‐induced angiogenesis may restrict tumor growth and metastasis. Long‐term systemic delivery of angiogenic inhibitors is associated with toxicity, as well as other severe side‐effects. The utility of cells as vehicles for gene therapy to deliver therapeutic molecules has been suggested to represent an efficient approach. Mesenchymal stem cells (MSCs) exhibit a tropism to cancer tissue, and may serve as a cellular delivery vehicle and a local producer of anti‐angiogenic agents.

Methods

In the present study, we attempted to assess production of the transgene, α1‐antitrypsin (AAT), in lentivirus‐transduced human MSCs and its cytotoxicity against human umbilical cord vein endothelial cells (HUVEC). The secreted protein from these effector cells was determined by an enzyme‐linked immunosorbent assay. The cytotoxicity of hMSCs that overexpress the human AAT gene against HUVEC was evaluated with an apoptotic assay.

Results

Lentivirus‐transduced hMSCs produced functional AAT and displayed much higher cytotoxicity against HUVEC than untransduced hMSCs. Moreover, AAT secreted from transduced hMSCs significantly inhibited HUVEC proliferation compared to untransduced hMSCs. The data obtained demonstrate for the first time that genetically modified hMSCs released abundant and functional AAT that caused obvious cytotoxicity to HUVEC.

Conclusions

hMSC may serve as an effective platform for the targeted delivery of therapeutic proteins to cancer sites. Copyright © 2011 John Wiley & Sons, Ltd.
Decreased proliferation of aging tenocytes is associated with down‐regulation of cellular senescence‐inhibited gene and up‐regulation of p27
Authors: Tsai Wen‐Chung , Chang Hsiang‐Ning , Yu Tung‐Yang , Chien Cheng‐Hsiu , Fu Li‐Fen , Liang Fang‐Chen , Pang Jong‐Hwei S.
Published: March 2011

Symptomatic tendinopathy tends to be age‐related. However, the molecular mechanisms of ageing and its effects on tenocyte proliferation and cell cycle progression are unknown. We examined tenocytes from Achilles tendons in rats from three age groups (young, 2 months; middle‐aged, 12 months, and near senescence, 24 months). Tenocyte proliferation was assessed by 3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide (MTT) assay and flow cytometry. Senescence‐associated β‐galactosidase (SA β‐gal) staining was performed in all groups of tenocytes. mRNA and protein expression of cellular senescence‐inhibited gene (CSIG) and p27 was measured by reverse transcription‐polymerase chain reaction (RT‐PCR) and Western blot, respectively. The results of MTT assay revealed that tenocyte proliferation decreased with age (p < 0.05). Cell cycle progression was arrested at G0/G1 phase in senescent tenocytes. More senescent tenocytes expressed SA β‐gal than young tenocytes did. By RT‐PCR and Western blot analysis, the gene and protein expression of CSIG was found to be down‐regulated, whereas that of p27 was up‐regulated with age. In conclusion, the proliferation of tenocytes declines with age and is associated with the down‐regulation of CSIG and up‐regulation of p27. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29: 1598–1603, 2011
Photoregulated Switching of the Recognition Site of α‐Cyclodextrin in a Side Chain Polyrotaxane Bearing Two Recognition Sites Linked with Oligo(ethylene glycol)
Authors: Hu Jie , Hashidzume Akihito , Harada Akira
Published: March 2011

A side chain polyrotaxane bearing photoresponsive and nonresponsive recognition sites, i.e., azobenzene (Azo) and heptamethylene (C7) moieties, respectively, linked with a long linker is synthesized. The photoregulated switching of the position of the rotor, i.e., α‐cyclodextrin (α‐CD), in the side chain polyrotaxane is demonstrated by two dimensional rotating frame Overhauser effect spectroscopy and circular dichroism spectroscopy: α‐CD includes the Azo moiety before UV irradiation, whereas α‐CD includes the C7 moiety after trans‐to‐cis photoisomerization of the Azo moieties.

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