bluuebunny/crossref_metadata_2025 huggingface dataset:
The application of numerical debris flow modelling for the generation of physical vulnerability curves
Authors: Quan Luna B. , Blahut J. , van Westen C. J. , Sterlacchini S. , van Asch T. W. J. , Akbas S. O.
Published: July 2011

Abstract. For a quantitative assessment of debris flow risk, it is essential to consider not only the hazardous process itself but also to perform an analysis of its consequences. This should include the estimation of the expected monetary losses as the product of the hazard with a given magnitude and the vulnerability of the elements exposed. A quantifiable integrated approach of both hazard and vulnerability is becoming a required practice in risk reduction management. This study aims at developing physical vulnerability curves for debris flows through the use of a dynamic run-out model. Dynamic run-out models for debris flows are able to calculate physical outputs (extension, depths, velocities, impact pressures) and to determine the zones where the elements at risk could suffer an impact. These results can then be applied to consequence analyses and risk calculations. On 13 July 2008, after more than two days of intense rainfall, several debris and mud flows were released in the central part of the Valtellina Valley (Lombardy Region, Northern Italy). One of the largest debris flows events occurred in a village called Selvetta. The debris flow event was reconstructed after extensive field work and interviews with local inhabitants and civil protection teams. The Selvetta event was modelled with the FLO-2D program, an Eulerian formulation with a finite differences numerical scheme that requires the specification of an input hydrograph. The internal stresses are isotropic and the basal shear stresses are calculated using a quadratic model. The behaviour and run-out of the flow was reconstructed. The significance of calculated values of the flow depth, velocity, and pressure were investigated in terms of the resulting damage to the affected buildings. The physical damage was quantified for each affected structure within the context of physical vulnerability, which was calculated as the ratio between the monetary loss and the reconstruction value. Three different empirical vulnerability curves were obtained, which are functions of debris flow depth, impact pressure, and kinematic viscosity, respectively. A quantitative approach to estimate the vulnerability of an exposed element to a debris flow which can be independent of the temporal occurrence of the hazard event is presented.
Comparison between Local and Regional Anesthesia in Arteriovenous Fistula Creation
Authors: Monte Attilio Ignazio Lo , Damiano Giuseppe , Mularo Antonino , Palumbo Vincenzo Davide , Alessi Rosi , Gioviale Maria Concetta , Spinelli Gabriele , Buscemi Giuseppe
Published: July 2011

Purpose

Assessment of the effectiveness of Brachial Plexus Block (BPB) via axillary approach compared to regional anesthesia for arteriovenous fistula surgery in patients affected by end-stage renal disease.

Methods

We compared forty patients randomly divided into two groups. Group A underwent BPB procedure with 15 mL ropivacaine 1% and 10 mL of saline (0.9% NaCl) via axillary approach. Group B received local anesthesia with lidocaine 2%. The forearm blood vessels were assessed by Doppler ultrasonography before and after the intervention.

Results

BPB performed on Group A was associated with a considerable venous dilation and a significant decrease (48.7%, P<.05) in pulsatility index (PI) measured by Doppler ultrasound. In Group B, PI and venous dilation remained unaltered in the postoperative phase. No complications such as thrombosis or occlusion were encountered among patients who underwent BPB.

Conclusions

The axillary-approached BPB was more advantageous than local anesthesia. Its effectiveness was because of venous dilation and the decrease in the PI, consequent to the reduction in peripheral resistances and the increase in local blood flow, thus offering an ideal background for fistula creation and short-term patency.
Synthesis and Characterization of Selenium Nanowires
Authors: Senthil kumaran C. K. , Agilan S. , Velauthapillai Dhayalan , Muthukumarasamy N. , Thambidurai M. , Senthil T. S. , Balasundaraprabhu R.
Published: July 2011

Selenium nanowires have been grown by chemical method. The effect of annealing on the properties of the prepared selenium nanowires has been studied. The X-ray diffraction studies indicated the formation of selenium with trigonal phase, and no secondary phase was observed. The composition analysis results show that selenium is present in the sample. HRTEM images reveal that selenium nanowires have diameter ranging from 30–50 nm and length of 1-2 μm. The diameter and length of nanowires have been found to increase with increase in annealing temperature.
TLC of selected sesquiterpenoids of the Asteraceae family
Authors: Nowak Gerard , Dawid-Pać Renata , Urbańska Maria , Nawrot Joanna
Published: July 2011

Visual chromatography has been employed for a preliminary identification of natural compound of a group of sesquiterpene lactones – Centaurea bella Trautv., C. crocodylium L., C. lusitanica Boiss. et Reuter, Helenium hoopesii A. Gray = Dugaldia hoopesii (A. Gray) Rydb., Stizolophus balsamita (Lam.) Cass., Zoegea baldschuanica C. Winkl., germacranes – Santolina pinnata Viv. subsp. neapolitana (Jord. et Fourr.) Guinea = S. neapolitana Jord. et Fourr. A dependence of the colour of the spots, induced by anisaldehyde reagent, on the presence of several substituents in the germacranolide ring – derivatives of partnenolide and salonitenolide – has been identified. The structures of the skeleton in the ring of sesquiterpene lactones in Helenium hoopesii can also be established by thin layer chromatography (TLC). The analysis of the chromatograms of extracts from dry and fresh Centaurea crocodylium herb has shown significant differences as for the chemical composition. Two sorts of germacranes of Santolina pinnata subsp. neapolitana display a characteristic colour of the spots.
Balance, gait, falls, and fear of falling in women with the hypermobility type of Ehlers‐Danlos syndrome
Authors: Rombaut Lies , Malfait Fransiska , De Wandele Inge , Thijs Youri , Palmans Tanneke , De Paepe Anne , Calders Patrick
Published: July 2011

Objective

To investigate balance, gait, falls, and fear of falling in patients with the hypermobility type of Ehlers‐Danlos syndrome (EDS‐HT).

Methods

Twenty‐two women with EDS‐HT and 22 sex‐ and age‐matched healthy control subjects participated in the study. Each subject performed the modified Clinical Test of Sensory Interaction on Balance (mCTSIB) and the Tandem Stance test (TS) on an AccuGait force platform to assess balance by center of pressure–based postural sway measures. The GAITRite walkway system was used to record spatial–temporal gait variables during 3 walking conditions (single task, cognitive task, and functional task). Data about fall frequency and circumstances were collected by retrospective recall, and fear of falling was assessed by the modified Falls Efficacy Scale.

Results

Compared with healthy subjects, EDS‐HT subjects showed significantly impaired balance, reflected by increased sway velocity, mediolateral and anteroposterior sway excursion, and sway area during mCTSIB and TS. Gait velocity, step length, and stride length were significantly smaller during all walking conditions, and a significant dual‐task–related decrement was found for gait velocity, step and stride length, and cadence in the EDS‐HT subjects compared to the control group. Ninety‐five percent of the patients fell during the past year, and some fear of falling was measured.

Conclusion

To our knowledge, this study is the first to establish that EDS‐HT is associated with balance and gait impairments, increased fall frequency, and poorer balance confidence, implying a decrease in the safety of standing in everyday life situations. Whether these deficits can be improved by appropriate exercise programs needs to be addressed in future research.
Geometry Working Beyond Effect
Authors: Burry Mark
Published: July 2011

With the onset of fully fledged file‐to‐factory design techniques, why should architects want to restrict themselves to the prescribed limits of descriptive geometry? In this article Mark Burry looks at a specific set of geometries ‐ doubly ruled surfaces ‐ that have been most explicitly developed by ‘structural artists’ Antoni Gaudí, Vladimir Shukhov and Félix Candela. He asks whether the application of doubly ruled surfaces like these might help us to make a significant distinction between architecture and sculpture. Copyright © 2011 John Wiley & Sons, Ltd.
Controlled Polarizability of One‐Nanometer‐Thick Oxide Nanosheets for Tailored, High‐κ Nanodielectrics
Authors: Osada Minoru , Takanashi Genki , Li Bao‐Wen , Akatsuka Kosho , Ebina Yasuo , Ono Kanta , Funakubo Hiroshi , Takada Kazunori , Sasaki Takayoshi
Published: July 2011

An important challenge in current microelectronics research is the development of techniques for making smaller, higher‐performance electronic components. In this context, the fabrication and integration of ultrathin high‐κ dielectrics with good insulating properties is an important issue. Here, we report on a rational approach to produce high‐performance nanodielectrics using one‐nanometer‐thick oxide nanosheets as a building block. In titano niobate nanosheets (TiNbO5, Ti2NbO7, Ti5NbO14), the octahedral distortion inherent to site‐engineering by Nb incorporation results in a giant molecular polarizability, and their multilayer nanofilms exhibit a high dielectric constant (160–320), the largest value seen so far in high‐κ nanofilms with thickness down to 10 nm. Furthermore, these superior high‐κ properties are fairly temperature‐independent with low leakage‐current density (<10−7 A cm−2). This work may provide a new recipe for designing nanodielectrics desirable for practical high‐κ devices.
Protein biostimulant foliar uptake modeling: The impact of climatic conditions
Authors: Pecha Jiří , Fürst Tomáš , Kolomazník Karel , Friebrová Veronika , Svoboda Petr
Published: July 2011

Biostimulants are substances which promote plant metabolism and are able to increase yields of various crops. However, their efficiency at field can be affected by climatic conditions. A novel mathematical model based on diffusion transport mechanism is proposed to predict the biostimulant uptake at different climatic conditions. The main input model parameter is experimentally measured effective diffusion coefficient of the biostimulant. The model is applied to a biostimulant prepared from leather waste by enzymatic hydrolysis. Simulations show that climatic conditions have significant impact on biostimulant penetration and should not be neglected in biostimulant application and further research. The suggested model is able to explain observed differences between laboratory and field biostimulant investigations, as well as draw recommendations for protein biostimulant application. The model also shows that the theoretical tools of chemical engineering can be used for optimization of biostimulant performance. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Design of a model‐based feedback controller for active sorting and synchronization of droplets in a microfluidic loop
Authors: Maddala Jeevan , Srinivasan Babji , Bithi Swastika S. , Vanapalli Siva A. , Rengaswamy Raghunathan
Published: July 2011

The transport of confined droplets in fluidic networks can lead to complex spatiotemporal dynamics, precluding full control of the position of droplets in the network. Here, we report the design of a model‐based feedback controller that can actively regulate droplet positions in a network. We specifically consider droplet dynamics in a microfluidic loop where a main channel splits into two and recombines. Consistent with previous studies, we find that without active control, the dynamics of droplets in the loop can range from periodic to chaotic behaviors. However, by implementing the model‐based feedback controller, we show that the droplets can be made to sort alternately into the branches of the loop as well as to synchronize the times at which pairs of droplets exit the loop. In particular, our computations demonstrate that the controller is capable of executing remarkable droplet sort‐synchronization tasks in the otherwise chaotic dynamics in the loop. The design of our controller incorporates a hydrodynamic network model, that is, capable of predicting droplet positions and subsequently delivering an actuation to the branches in the loop through elastomeric valves. Efficacy of the controller is discussed in terms of actuation characteristics and constraints imposed by elastomeric valves. The model‐based feedback controller framework presented in this study is likely to promote the development of lab‐on‐chip technologies in which droplet manipulation tasks are executed with active control. © 2011 American Institute of Chemical Engineers AIChE J, 2012
Cyclobutane in der Katalyse
Authors: Seiser Tobias , Saget Tanguy , Tran Duc N. , Cramer Nicolai
Published: July 2011

Ein hoch geschätztes Prinzip in der organischen Chemie ist das Ausnutzen von Ringspannung als Triebkraft, um chemische Reaktionen zu erleichtern. Die bekanntesten und am häufigsten genutzten Verbindungsklassen in dieser Hinsicht sind Epoxide und Cyclopropane. Cyclobutane haben dieser Entwicklung relativ lange hinterhergehinkt, doch in den letzten zehn Jahren wurde eine steigende Zahl an bemerkenswerten Reaktionen entwickelt, die Vierringe als Substrate verwenden. Dieser Kurzaufsatz fasst entsprechende katalytische Reaktionen, von Lewis‐ über Brønsted‐Säure‐katalysierte bis hin zu enzymatischen Prozessen, zusammen. Das Hauptaugenmerk liegt dabei auf übergangsmetallkatalysierten C‐C Bindungsinsertionen und β‐Kohlenstoff‐Eliminierungen. Diese Reaktionen ermöglichen faszinierende Folgeprozesse, die zu vielseitigen Synthesebausteinen führen.
Film processability and properties of polycaprolactone/thermoplastic starch blends
Authors: Ramírez‐Arreola Daniel E. , Robledo‐Ortiz Jorge R. , Moscoso Francisco , Arellano Martín , Rodrigue Denis , González‐Núñez Rubén
Published: July 2011

In this work, the processing and properties of blown films prepared from thermoplastic corn starch (TPS) and polycaprolactone (PCL) were studied, in particular at high TPS content. The influence of processing parameters and material moisture content on the tensile properties was also studied. The results show that final film properties are mainly controlled by the draw ratio, blow‐up ratio and PCL concentration in the blends. The results also show that PCL/TPS films are less hydrophilic as PCL content increases. Finally, it was found that a very narrow processing window exists for this blend. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Solution and diffusion properties of cyclohexane, cyclohexanol, and cyclohexanone in poly(ethylene glycol) by inverse gas chromatography
Authors: Zeng Chuyi , Huang Min , Zhao Hong , Zhou Jicheng , Li Jiding
Published: July 2011

The solution and diffusion properties of cyclohexane, cyclohexanol, and cyclohexanone in poly(ethylene glycol) (PEG) and crosslinked PEG have been studied in the temperature range of 368.15 to 403.15 K using inverse gas chromatography (IGC) technique. The infinite dilute activity coefficient (Ω) and diffusion coefficient (D) have been determined for the above solvent/polymer systems. Accordingly, several thermodynamic functions, the diffusion pre‐exponential factor, and activation energy have been attained. The results showed a decrease in Ω and an increase in D with rising temperature. The order of the relative magnitude of Ω and D of the solvents were explained by comparing their interactions with the polymer and their collision diameters, respectively. Moreover, Ω and D in crosslinked PEG were smaller than those in PEG at various temperatures. The analysis of Ω, the infinite dilute selectivity and capacity showed the possibility of using crosslinked PEG as an appropriate membrane material for the separation of cyclohexane, cyclohexanol, and cyclohexanone mixture. A thermodynamic study also implied that the solvent sorptions in the polymers were all enthalpically driven in the experimental range. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Effects of filler type on the nonisothermal crystallization kinetics of poly(butylene terephthalate) (PBT) composites
Authors: Oburoğlu Nur , Ercan Nevra , Durmus Ali , Kaşgöz Ahmet
Published: July 2011

In this study, melt‐crystallization behaviors of poly(butylene terephthalate) (PBT) composites including different types of inorganic fillers were investigated. Composite samples having 5 wt % of fillers were prepared by melt processing in a twin screw extruder using commercial grades of calcite (CA), halloysite (HL), and organo‐montmorillonite (OM) as filler. Depending on the filler type and geometry, crystallization kinetics of the samples was studied by differential scanning calorimetry (DSC) methods. Effect of filler type on the nonisothermal melt‐crystallization kinetics of the PBT was analyzed with various kinetic models, namely, the Ozawa, Avrami modified by Jeziorny and Liu‐Mo. Crystallization activation energies of the samples were also determined by the Kissinger, Takhor, and Augis–Bennett models. From the kinetics study, it was found that the melt‐crystallization rates of the samples including CA and HL‐nanotube were higher than PBT at a given cooling rate. On the other hand, it was also found that organo‐montmorillonite reduced the melt‐crystallization rate of PBT. It can be concluded that organic ammonium groups in the OM decelerate the crystallization rate of PBT chains possibly due to affecting the chain diffusion through growing crystal face and folding. This study shows that introducing organically modified alumina‐silicate layers into the PBT‐based composites could significantly reduce the production rate of the injection molded parts during the processing operations. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Elongational and shear flow behavior of calcium carbonate filled low density polyethylene: Effect of filler particle size, content, and surface treatment
Authors: Zoukrami Fouzia , Haddaoui Nacerddine , Bailly Christian , Sclavons Michel , Legras Roger
Published: July 2011

In this article, calcium carbonate filled low density polyethylene (LDPE) was prepared and the influence of filler content, particle size, and surface treatment with stearic acid on the strain hardening and viscoelastic properties of the composites were investigated. Both elongational and shear rheological measurements were conducted on the different formulations and completed by microscopical observations and by differential scanning thermal analysis. The obtained results indicate that the effect of filler content and particle size are negligible on strain hardening behavior. Also the filler surface treatment has a less important effect on the nonlinear elongational tests in comparison with low frequency range measurements. However in shear rheology, we noted the absence of yield stress and network structure at different filler contents, and the presence of shear thinning behavior. Scanning electron microscopy (SEM) observations showed the enhancement of dispersion for surface treated samples, while differential scanning calorimetry (DSC) experiments have shown that the content of crystallinity of LDPE matrix is slightly affected by the presence of filler. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The conservation status of Sabellaria alveolata (L.) (Polychaeta: Sabellariidae) reefs in the Bay of Mont‐Saint‐Michel
Authors: Desroy N. , Dubois S. F. , Fournier J. , Ricquiers L. , Le Mao P. , Guerin L. , Gerla D. , Rougerie M. , Legendre A.
Published: July 2011

Reefs built by the annelid worm Sabellaria alveolata in the Bay of Mont‐Saint‐Michel (France) are the most extensive intertidal biogenic structures within Europe. Before and after mussel farming extensions, a study designed to provide a biological health index of the Sainte‐Anne reef (223 ha) was carried in 2001 and 2007 to serve as an easy‐to‐use management tool and to ensure endangered reef portions were properly targeted and protected.

Coupled physical and biological parameters were included in a spatial Health Status Index (HI). A spatial and temporal mapping survey of the HI showed a continuous deterioration of the reef's state of health, particularly in its central part. This degradation correlates with the colonization of the Pacific oyster Crassostrea gigas and with increasing silt deposits on the reef.

A combination of several factors is likely to explain such rapid reef deterioration: (1) an increase in trophic competition between cultivated and wild suspension‐feeders that is detrimental to the annelids; (2) a modification in the hydrodynamics and consequently in sedimentary patterns leading to an increase in silt deposition; and most importantly (3) an increase in recreational harvesting of oysters and associated reef trampling, resulting in reef fragmentation.

Understanding the parameters that influence the reef dynamics is necessary in order to help efficient and effective management and policy focusing on the conservation status of large biogenic structures.

Copyright © 2011 John Wiley & Sons, Ltd.
Activated memory B cells may function as antigen‐presenting cells in the joints of children with juvenile idiopathic arthritis
Authors: Morbach Henner , Wiegering Verena , Richl Petra , Schwarz Tobias , Suffa Nadine , Eichhorn Eva‐Maria , Eyrich Matthias , Girschick Hermann J.
Published: July 2011

Objective

B cells impact the perpetuation of chronic inflammatory or autoimmune diseases in multiple ways. A role of B cells as antigen‐presenting cells (APCs) in the pathogenesis of chronic arthritis in humans has been suggested; however, as of yet the presence of such B cells at the site of inflammation has not been demonstrated. This study was undertaken to investigate whether synovial B cells in patients with juvenile idiopathic arthritis (JIA) might display features of APCs.

Methods

The frequency, phenotype, and immunoglobulin repertoire of synovial B cells were studied by flow cytometry and single‐cell polymerase chain reaction (PCR). Cytokine expression by B cells was analyzed by real‐time PCR, and interaction between B cells and T cells was investigated in a mixed lymphocyte culture.

Results

CD27+IgD− and CD27−IgD− B cells accumulated in the joints of JIA patients and displayed an activated phenotype. Both B cell subsets expressed hypermutated and class‐switched immunoglobulins, indicators of memory B cells. The accumulating memory B cells expressed the costimulatory molecules CD80/CD86 and showed a higher capacity to activate allogeneic T cells and prime a Th1 phenotype than their peripheral blood counterparts.

Conclusion

Activated immunoglobulin class–switched CD27− and CD27+ memory B cells, indicating a phenotype of APCs with expression of costimulatory molecules, accumulate in the joints of patients with JIA and might be involved in the amplification of pathogenic T cell activation. These findings provide evidence that B cells play an antibody‐independent immunopathologic role in human chronic inflammatory arthritis of childhood.
Gender Differences in the Assessment, Stability, and Correlates to Bullying Roles in Middle School Children
Authors: Crapanzano Ann Marie , Frick Paul J. , Childs Kristina , Terranova Andrew M.
Published: July 2011

The current study investigated bullying behaviors in 284 school children in the fourth through seventh grades at the time of the initial assessment. Peer ratings of bullying behavior were obtained at the end of the spring semester of one school year and at the end of the fall semester of the next school year. Importantly, peer ratings were obtained by assessing not only the level at which participants actually bully other students but also whether participants help bullies to hurt the victim (assister), encourage bullies (reinforce), or help the victim of bullying (defender). Our results did not support the utility of differentiating between bullies, assisters, or reinforcers. Specifically, these bullying roles were highly intercorrelated, both concurrently and across school years, and they showed similar correlations with aggression and several characteristics often associated with aggression (i.e., conduct problems, callous‐unemotional traits, and positive expectancies about aggression). In contrast, ratings of defending designated a particularly prosocial group of students. Finally, whereas bullying appeared to be very similar in boys and girls, it was somewhat more stable across school years and was related to lower levels of prosocial behavior in boys, both of which could suggest that bullying may be somewhat more related to social group dynamics in girls. Copyright © 2011 John Wiley & Sons, Ltd.
Migrating type a intramural hematoma after repair of an anomalous right coronary artery aortocoronary dissection with a covered stent
Authors: Fang Hsiu‐Yu , Wu Chiung‐Jen
Published: July 2011

Iatrogenic aortocoronary dissection is a rare and potentially life‐threatening complication of percutaneous coronary intervention (PCI). Prompt coronary stenting can stop progression and avoid the need for surgical intervention. Herein, we describe a case of migrating aortic intramural hematoma (IMH) after repair of an anomalous right coronary artery aortocoronary dissection with a covered stent. © 2011 Wiley‐Liss, Inc.
Versatile Low‐Molecular‐Weight Hydrogelators: Achieving Multiresponsiveness through a Modular Design
Authors: Milanesi Lilia , Hunter Christopher A. , Tzokova Nadejda , Waltho Jonathan P. , Tomas Salvador
Published: July 2011

Multiresponsive low‐molecular‐weight hydrogelators (LMWHs) are ideal candidates for the development of smart, soft, nanotechnology materials. The synthesis is however very challenging. On the one hand, de novo design is hampered by our limited ability to predict the assembly of small molecules in water. On the other hand, modification of pre‐existing LMWHs is limited by the number of different stimuli‐sensitive chemical moieties that can be introduced into a small molecule without seriously disrupting the ability to gelate water. Herein we report the synthesis and characterization of multistimuli LMWHs, based on a modular design, composed of a hydrophobic, disulfide, aromatic moiety, a maleimide linker, and a hydrophilic section based on an amino acid, here N‐acetyl‐L‐cysteine (NAC). As most LMWHs, these gelators experience reversible gel‐to‐sol transition following temperature changes. Additionally, the NAC moiety allows reversible control of the assembly of the gel by pH changes. The reduction of the aromatic disulfide triggers a gel‐to‐sol transition that, depending on the design of the particular LMWH, can be reverted by reoxidation of the resulting thiol. Finally, the hydrolysis of the cyclic imide moieties provides an additional trigger for the gel‐to‐sol transition with a timescale that is appropriate for use in drug‐delivery applications. The efficient response to the multiple external stimuli, coupled to the modular design makes these LMWHs an excellent starting point for the development of smart nanomaterials with applications that include controlled drug release. These hydrogelators, which were discovered by serendipity rather than design, suggest nonetheless a general strategy for the introduction of multiple stimuli‐sensitive chemical moieties, to offset the introduction of hydrophilic moieties with additional hydrophobic ones, in order to minimize the upsetting of the critical hydrophobic–hydrophilic balance of the LMWH.
Bulk and surface mechanical properties of clay modified HDPE used in liner applications
Authors: Adewole Jimoh K. , Al‐Mubaiyedh Usamah A. , Ul‐Hamid Anwar , Al‐Juhani Abdulhadi A. , Hussein Ibnelwaleed A.
Published: July 2011

High‐density polyethylene (HDPE)/clay nanocomposites were prepared by melt blending process. The HDPE was mixed with different organoclays and polyethylene‐grafted‐maleic anhydride was used as a compatibiliser. A masterbatch procedure was used to obtain final organoclays concentrations of 1, 2.5 and 5 wt%. The effects of various types of nanoclays and their concentrations on morphological, thermal and mechanical properties of nanocomposites were investigated. Surface mechanical properties such as instrumented nanohardness, modulus of elasticity and creep were also measured using a nanoindentation technique. Young's, storage and loss moduli, were found to be higher than that of the neat polymer at low loading (2.5 wt%) for clay Cloisite 15A and at higher loading (5 wt%) for clay Nanomer 1.44P. The ultimate strength and the toughness decreased slightly compared to pure HDPE. The differential scanning calorimetry analysis revealed that the peak temperature of the nanocomposites increased with increased clay content while the crystallinity decreased. Also, dynamic mechanical analysis revealed the storage and loss moduli are enhanced by addition of nanoclay. Both mechanical and thermal properties of HDPE/Nanomer 1.44P nanocomposite showed interesting trends. All properties first dropped when 1 wt% of the clay was added. Thereafter, a gradual increase or decrease then followed as the loading of Nanomer was increased. These trends were observed for all mechanical properties. The results obtained from nanoindentation tests for surface mechanical properties also showed similar trend to that of bulk measurements. Based on these measurements a nanoclay additive for a liner grade HDPE was selected. © 2011 Canadian Society for Chemical Engineering
Application of immunocytochemistry and BRAF mutational analysis to direct smears of metastatic melanoma
Authors: Hookim Kim , Roh Michael H. , Willman Joseph , Placido Jeremiah , Weigelin Helmut C. , Fields Kristina L. , Pang Judy , Betz Bryan L. , Knoepp Stewart M.
Published: July 2011

BACKGROUND:

The cytodiagnosis of melanoma in fine‐needle aspiration (FNA) specimens can be challenging, often requiring the use of immunocytochemistry. As constitutively activating mutations in the BRAF oncogene are present in at least 40% of melanomas, the use of FNA material to interrogate the BRAF mutational status is likely to increase. Because cell blocks, traditionally used for these studies, can occasionally exhibit insufficient tumor cellularity, the authors investigated the utility of direct smears for immunocytochemistry and BRAF mutational analysis.

METHODS:

Immunocytochemistry for S‐100, HMB‐45, and Mart‐1 was prospectively performed on direct smears in 17 FNAs of metastatic melanoma. Next, BRAF sequencing was performed using DNA isolated from archived Diff‐Quik–stained direct smears for 15 cases. In parallel, sequencing was performed using DNA obtained from corresponding cell blocks.

RESULTS:

S‐100 positivity in the tumor cells was observed in all 17 cases. HMB‐45 and Mart‐1 positivity was noted in 81% and 88% of cases, respectively. All 3 markers were positive in 76% of cases. Next, of the 15 archived melanoma FNAs tested, BRAF mutations were observed in 8 (53%); 5 and 3 melanomas harbored the V600E and V600K mutation, respectively. Corresponding cell blocks were also tested for all 15 cases, yielding concordant BRAF results in 14 (93%); 1 cell block yielded a false‐negative result.

CONCLUSIONS:

Cytologic direct smears represent a robust and valuable source of cellular material for immunocytochemistry and molecular studies, especially in instances in which inadequate cell block cellularity is anticipated or encountered. Cancer (Cancer Cytopathol) 2012. © 2011 American Cancer Society.
A missing link in thymic dendritic cell development
Authors: Krueger Andreas
Published: July 2011

Negative selection in the thymus prevents the generation of self‐reactive T cells through the deletion of thymocytes with high affinity for self‐antigens. Within the thymus, self‐antigens are presented by thymic epithelial cells and DCs. Both cell types can mediate negative selection, although the relative contribution of each cell type remains elusive. Similar to DCs of other lymphoid organs, thymic DCs come in different flavors. Over the past years, various lines of evidence have emerged that either favor a common origin for some thymic DCs and thymocytes or, conversely, indicate the existence of separate intrathymic T lineage and DC precursors. In this issue of the European Journal of Immunology, a study reports the identification of an intrathymic DC precursor that is likely to be unrelated to the earliest physiological T‐cell progenitors. Thus this intrathymic DC precursor may constitute a “missing link” between extrathymic DC precursor‐types, which are able to generate DCs in secondary lymphoid organs and intrathymic DCs, and supports the notion that intrathymic DCs and thymocytes arise from different precursors.
New FeII and CuII Complexes Bearing Azathia Macrocycles – Catalyst Precursors for Mild Peroxidative Oxidation of Cyclohexane and 1‐Phenylethanol
Authors: Fernandes Ricardo R. , Lasri Jamal , Kirillov Alexander M. , Guedes da Silva M. Fátima C. , da Silva José A. L. , Fraústo da Silva João J. R. , Pombeiro Armando J. L.
Published: July 2011

The new mononuclear FeII and CuII complexes [FeCl2(L1,3)] [L1 (1), L3 (4)], [Cu(OTf)2(L1,2)] [L1 (2), L2 (3)] and [Cu(OTf)(L3)(H2O)](OTf) (5) were generated by the treatment of iron(II) chloride or copper(II) triflate in THF solution at ambient temperature with the 14‐membered N2S2 macrocycles 6,7,13,14,15,16,17,18‐octahydrodibenzo(e,m)‐1,4,8,11‐dithiadiazacyclotetradecine (L1), 8,11‐dimethyl‐5,6,7,8,9,10,16,17‐octahydrodibenzo(e,m)‐1,4‐dithia‐8,11‐diazacyclotetradecane (L2), and a new nine‐membered NS2 macrocycle bearing a pendant 2‐methylpyridyl arm 7‐(2‐methylpyridyl)aza‐1,4‐dithiacyclononane (L3). Complexes 1–5 were characterized by IR spectroscopy, ESI‐MS(+), elemental analysis and single‐crystal X‐ray diffraction (for 2, 4 and 5). The oxidation catalytic properties of 1–5 were evaluated in two model reactions: (i) the mild oxidation of cyclohexane to cyclohexanol and cyclohexanone by H2O2 in MeCN and (ii) the solvent‐free oxidation of 1‐phenylethanol to acetophenone by tBuOOH under low microwave (MW) irradiation power (10 W). The FeII complexes 1 and 4 exhibited the highest efficiency in both homogeneous oxidation systems, leading to maximum product yields (based on substrate) of up to 21 and 92 % in the oxidation of cyclohexane and 1‐phenylethanol, respectively. In the latter transformation, markedly high values of TONs (up to 1200) and TOFs (up to 4200 h–1) were also attained.
Benzoic Acid Catalyzed Aldol‐Type Condensation of Aldehydes with Ethyl Diazoacetate: Highly Diastereoselective Products with Chiral Aldehydes
Authors: Krishna Palakodety Radha , Prapurna Y. Lakshmi , Alivelu Munagala
Published: July 2011

Benzoic acid catalyzed aldol‐type condensation of aldehydes with ethyl diazoacetate (EDA) under neat conditions at room temperature to afford β‐hydroxy‐α‐diazo carbonyl compounds in good to excellent yields is reported. Furthermore, the condensation of EDA with sugar‐derived aldehydes under the same conditions afforded the adducts in excellent yields and high diastereoselectivities.
Comparative Studies of Multi‐Photon Induced Emission by Pyridine‐Based Small Molecular Probes in Biological Media: Selective Binding of Bioactive Molecules and In Vitro Imaging
Authors: Wu Wanqing , Kong Hoi‐Kuan , Li Hongguang , Ho Yu‐Man , Gao Yuan , Hao Jianhua , Murphy Margaret B. , Lam Michael Hon‐Wah , Wong Ka‐Leung , Lee Chi‐Sing
Published: July 2011

A new class of organic molecular probes (1–3) based on a 1,3‐disubstituted diethynylbenzene core has been developed. Both 1 and 2 (with the esters of 1 replaced by diethylamides in 2) show good linear and three‐photon induced photophysical properties with two‐photon absorption cross‐sections (185–210 cm4 s photon–1 molecule–1) that are suitable for biological applications in live specimens. The propeller π‐conjugated systems of 3 (a C3 analogue of 1) shows threefold enhancement for the two‐photon absorption cross‐section (650 cm4 s photon–1 molecule–1). Solvatochromism was observed in the fluorescence spectra of all these molecular probes; in acidic medium (pH = 4–5) their fluorescence emissions are slightly blueshifted with a threefold enhancement in intensity relative to those observed under basic conditions (pH = 10–11). In the fluorometric titration study against a variety of bioactive small molecules, only 2 shows strong binding affinity (log KB > 7) towards citrates and bicarbonates with approximately 30 nm redshift. The in vitro emission spectra of 2 obtained show the same emission upon addition of anions to the solution. The results of these studies could provide new molecular‐design strategies for two‐photo absorption (TPA) chromophores and new materials for two/multi‐photon imaging in vitro.
Environmental and sustainability aspects of a recirculating aquaculture system
Authors: Midilli Adnan , Kucuk Haydar , Dincer Ibrahim
Published: July 2011

This article presents some new exergy‐based parameters for Recirculating Aquaculture System (RAS) for Black Sea trout (Salmo trutta labrax) at the Trabzon Central Fisheries Research Institute, Turkey. On the basis of the actual data employed, some environmental and sustainability aspects of the RAS are parametrically studied in terms of exergy parameters. In this regard, the exergetic parameters, such as exergetic efficiency, waste exergy ratio, exergy recoverability ratio, exergy destruction ratio, environmental impact factor, and exergetic sustainability index are proposed and investigated. The results show that mainly based on the operating principle of the RAS, increasing waste exergy ratio decreases the exergetic efficiency and exergetic sustainability index. However, any increase in waste exergy ratio results in an increasing environmental impact of the RAS. Thus, the RAS requires much more improvement because of the higher environmental impact factor and lower exergetic sustainability index during the operating the system. This is evident from the exergy recoverability ratios ranging from 0.27 to 0.37. Furthermore, studying these parameters indicates how much improvement is possible for the RAS to achieve better sustainability. © 2011 American Institute of Chemical Engineers Environ Prog, 2011
Prediction of odour detection thresholds using partition coefficients
Authors: Rodríguez Oscar , Teixeira Miguel A , Rodrigues Alírio E
Published: July 2011

A linear regression between odour detection thresholds and three basic physical properties (vapour pressure, water solubility and octanol/water partition coefficient) has been derived. The principles underlying this model are the transport process of the odorants from air to the olfactory neurons in the nasal epithelium. The regression was applied to odour detection thresholds measured from different authors separately, showing similar parameters. A general linear regression was obtained for odour detection threshold data from several authors and 121 chemicals. This regression allows a preliminary estimation of odour detection thresholds from literature data with fair accuracy. The coefficient of determination obtained,r2 = 0.769, indicates that these physical properties account for 77% of the odour threshold variance. Copyright © 2011 John Wiley & Sons, Ltd.
Comparing laboratory and field measured bioaccumulation endpoints
Authors: Burkhard Lawrence P , Arnot Jon A , Embry Michelle R , Farley Kevin J , Hoke Robert A , Kitano Masaru , Leslie Heather A , Lotufo Guilherme R , Parkerton Thomas F , Sappington Keith G , Tomy Gregg T , Woodburn Kent B
Published: July 2011

An approach for comparing laboratory and field measures of bioaccumulation is presented to facilitate the interpretation of different sources of bioaccumulation data. Differences in numerical scales and units are eliminated by converting the data to dimensionless fugacity (or concentration-normalized) ratios. The approach expresses bioaccumulation metrics in terms of the equilibrium status of the chemical, with respect to a reference phase. When the fugacity ratios of the bioaccumulation metrics are plotted, the degree of variability within and across metrics is easily visualized for a given chemical because their numerical scales are the same for all endpoints. Fugacity ratios greater than 1 indicate an increase in chemical thermodynamic activity in organisms with respect to a reference phase (e.g., biomagnification). Fugacity ratios less than 1 indicate a decrease in chemical thermodynamic activity in organisms with respect to a reference phase (e.g., biodilution). This method provides a holistic, weight-of-evidence approach for assessing the biomagnification potential of individual chemicals because bioconcentration factors, bioaccumulation factors, biota–sediment accumulation factors, biomagnification factors, biota–suspended solids accumulation factors, and trophic magnification factors can be included in the evaluation. The approach is illustrated using a total 2393 measured data points from 171 reports, for 15 nonionic organic chemicals that were selected based on data availability, a range of physicochemical partitioning properties, and biotransformation rates. Laboratory and field fugacity ratios derived from the various bioaccumulation metrics were generally consistent in categorizing substances with respect to either an increased or decreased thermodynamic status in biota, i.e., biomagnification or biodilution, respectively. The proposed comparative bioaccumulation endpoint assessment method could therefore be considered for decision making in a chemicals management context. Integr Environ Assess Manag 2012;8:17–31. © 2011 SETAC
Children's memories for events relating to treatment for eye cancer: Influence of age at loss of eye
Authors: Norgate Sarah H. , Littleton Karen S.
Published: July 2011

Treatment for retinoblastoma frequently involves removal of at least one eye in the first 5 years. Variation in age of treatment leads to the assumption that children's later verbal accessibility of early traumatic memories may vary, with some children having less opportunity to make sense of their condition. Video recordings were made of 17 children who had undergone enucleation either before 24 months (n = 8) or after 24 months (n = 9) involved in “hospital play'' using props designed to elicit talk about “eyes.” The hypothesis that a larger number of verbalizations about medical procedures would occur in children enucleated after 24 months than before 24 months was supported. Children enucleated after 24 months engaged in significantly more talk about enucleation and/or examination under anesthetic whereas none of the children enucleated in infancy talked about these medical events. The outcome supports the view that there is a transition around 24 months in the extent to which children can have verbal access to previous traumatic memories. The design of interventions needs to take into account that children enucleated in infancy have less opportunity for later verbal access to early memories of traumatic events than those treated later, leading to possible misconceptions about their own condition.
Nervous system effects of dissolved and nanoparticulate cadmium in rats in subacute exposure
Authors: Horváth Edina , Oszlánczi Gábor , Máté Zsuzsanna , Szabó Andrea , Kozma Gábor , Sápi András , Kónya Zoltán , Paulik Edit , Nagymajtényi László , Papp András
Published: July 2011

Cadmium, a toxic heavy metal with various applications in technology, can affect people both by environmental (foodborne) and occupational (inhalation) exposure and can cause nervous system damage. To model this, rats were subacutely treated either with CdCl2 solution per os (3.0 mg kg−1 b.w.) or nanoparticulate CdO2 (particle size ca 65 nm) by intratracheal instillation (0.04 mg kg−1 b.w.) alone or in sequential combination. Nervous system effects were observed at different levels of function (open field behavior, cortical electrical activity, nerve action potential) and some general toxicological indicators were also measured. Three weeks of oral plus one week of intratracheal exposure caused significant reduction of body weight gain and open field motility. Lengthening of latency of sensory evoked potentials, observed in all treated rats, was also the most significant in the group receiving oral plus intratracheal treatment. Conduction velocity of the tail nerve was likewise decreased in all treated groups. Several of the effects pointed to a potentiating interaction between the two forms of Cd. Modeling environmental and occupational Cd exposure by oral and intratracheal application in rats was feasible, with results suggesting serious negative health effects in humans suffering such a combined exposure.
Mechanical improvements to reinforced porous silk scaffolds
Authors: Gil Eun Seok , Kluge Jonathan A. , Rockwood Danielle N. , Rajkhowa Rangam , Wang Lijing , Wang Xungai , Kaplan David L.
Published: July 2011

Load‐bearing porous biodegradable scaffolds are required to engineer functional tissues such as bone. Mechanical improvements to porogen leached scaffolds prepared from silk proteins were systematically studied through the addition of silk particles in combination with silk solution concentration, exploiting interfacial compatibility between the two components. Solvent solutions of silk up to 32 w/v % were successfully prepared in hexafluoroisopropanol (HFIP) for the study. The mechanical properties of the reinforced silk scaffolds correlated to the material density and matched by a power law relationship, independent of the ratio of silk particles to matrix. These results were similar to the relationships previously shown for cancellous bone. From these data we conclude that the increased mechanical properties were due to a densification effect and not due to the inclusion of stiffer silk particles into the softer silk matrix. A continuous interface between the silk matrix and the silk particles, as well as homogeneous distribution of the silk particles within the matrix was observed. Furthermore, we note that the roughness of the pore walls was controllable by varying the ratio of the particles matrix, providing a route to control topography. The rate of proteolytic hydrolysis of the scaffolds decreased with increase in mass of silk used in the matrix and with increasing silk particle content. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 99A: 16–28, 2011.
Density functional study of neutral and anionic AlOn and ScOn with high oxygen content
Authors: Gutsev G. L. , Weatherford C. A. , Pradhan K. , Jena P.
Published: July 2011

The electronic and geometrical structures of neutral and negatively charged AlO5, AlO6, AlO7, AlO8, AlO9, AlO10, AlO11, AlO12, AlO15, AlO16, and AlO18 along with the corresponding series of ScOn and ScO oxides were investigated using density functional theory with generalized gradient approximation. We found that these species possess geometrically stable isomers for all values of n = 5–12, 15, 16, 18 and are thermodynamically stable for n = 5–7. The species with n = 16 are found to be octa‐dioxides M(η1‐O2)8 while the species with n = 15 and 18 are penta‐ozonides (η2‐O3)M(η1‐O3)4 and hexa‐ozonides M(η1‐O3)6, respectively. Geometrical configurations of a number of the lowest total energy states of Al and Sc oxides are different. Especially, drastic differences are found for the anion AlO and ScO pairs at n = 9, 10, and 11. The ScO bonds are longer than the AlO bonds by ≈0.2 Å, which, in turn, slightly affects the corresponding interoxygen bond lengths. The charges on metal atoms are close to +2e in both Al series and to +1.5e in both Sc series. As an extra electron is delocalized over ligands in the presence of a large positive charge on the metal atom of the anions, the electron affinity (EA) of the neutrals along with the ionization energies of the anions are large and exceed the EAs of the halogen atoms in a number of cases. © 2011 Wiley Periodicals, Inc. J Comput Chem 2011