bluuebunny/crossref_metadata_2025 huggingface dataset:
Chiral calix[4]arenes bearing amino alcohol functionality as membrane carriers for transport of chiral amino acid methylesters and mandelic acid
Authors: Bozkurt Selahattin , Yilmaz Mustafa , Sirit Abdulkadir
Published: December 2011

Novel chiral calix[4]arene derivatives bearing amino alcohol moieties at the lower rim have been synthesized from the reaction of p‐tert‐butylcalix[4]arene diester with various amino alcohols. The transport of amino acid esters (phenylglycine, phenylalanine, and tryptophan methyl esters hydrochloride) and mandelic acid were studied through chloroform bulk liquid membrane system using chiral calix[4]arenes 15, 16, 17, 18, 19, 20. All these receptors have been found to act as carriers for transport of aromatic amino acid methylesters and mandelic acid from the aqueous source phase to the aqueous receiving phase. The influence of calixarene and guest structures upon transport through liquid membrane is discussed. Chirality, 2012. © 2011 Wiley Periodicals, Inc.
Enantioselective toxicity of metolachlor to scenedesmus obliquus in the presence of cyclodextrins
Authors: Liu Hui J. , Cai Wei D. , Huang Ruo N. , Xia Hui L. , Wen Yue Z.
Published: December 2011

Cyclodextrins (CDs) possess a variety of chiral centers and are capable of recognizing enantiomeric molecules through the formation of inclusion complexes. Two types of CDs, α‐cyclodextrin (α‐CD) and β‐cyclodextrin (β‐CD), were selected to evaluate the effects of the enantioselective ecotoxicity of racemic metolachlor (Rac‐metolachlor) and its S‐enantiomer (S‐metolachlor) on the freshwater algae Scenedesmus obliquus (S. obliquus) by acute toxicity test. The results showed that the aquatic toxicity of S‐metolachlor was higher than Rac‐metolachlor and that CDs enhanced the toxicity of metolachlor enantioselectively by increasing the aquatic toxicity of Rac‐metolachlor rather than that of S‐metolachlor to S. obliquus. The equilibrium constant for Rac‐metolachlor‐CD complexes was higher than that of S‐metolachlor‐CDs, which was responsible for the greater aquatic toxicity shift effect of Rac‐metolachlor. Thermodynamic studies of CD complexes showed that inclusion for all of the complexes was primarily a spontaneous, enthalpy‐driven process. These results will help to understand the preliminary mechanism of shifting aquatic toxicity of metolachlor by CDs and the CDs mediated environmental processes of metolachlor, to correctly apply CDs to chiral pesticides formulation and environmental remediation of chiral contaminants. Chirality, 2012. © 2011 Wiley Periodicals, Inc.
Effect of trichlorobenzene additive on the performance and morphology of polyfluorene and fullerene derivative bulk heterojunction solar cells
Authors: Koetniyom W. , Keawprajak A. , Piyakulawat P. , Jiramitmongkon K. , Nukeaw J. , Pratontep S. , Asawapirom U.
Published: December 2011

The influence of additive, namely 1,3,5‐trichlorobenzene (TCB), on the morphology and performance of bulk heterojunction (BHJ) organic solar cells was studied based on a 1:2 (w/w) blend of benzothiadiazole/thiophene‐based copolymers (PFTBzTT) to [6,6]‐phenyl‐C61 butyric acid methyl ester (PCBM). The active layers were deposited by spin‐coating from solutions using chloroform, with different additive concentrations from 0 to 36 mg/ml. The addition of solvent additive into the polymer solution was able to improve the performance of BHJ solar cells. The maximum power conversion efficiency (%PCE) of 0.85% was obtained for a cell with the TCB concentration of 12 mg/ml after annealing at 180°C for 20 min. From atomic force microscopy (AFM) images, the films processed without TCB appear smoother than those with the TCB additive. A large extent of segregation was also observed in the films processed with a high TCB concentration. The optical images of the thin films suggest that the optimum concentrations of the additive cause the polymer self‐organisation, resulting in some aggregation of large PCBM crystals. © 2011 Canadian Society for Chemical Engineering
Mapping of Surface‐Enhanced Fluorescence on Metal Nanoparticles using Super‐Resolution Photoactivation Localization Microscopy
Authors: Lin Hongzhen , Centeno Silvia P. , Su Liang , Kenens Bart , Rocha Susana , Sliwa Michel , Hofkens Johan , Uji‐i Hiroshi
Published: December 2011

Photoactivation localization microscopy (PALM) was applied to study surface‐enhanced fluorescence (SEF) on metal nanostructures (SEF‐PALM). The detection of fluorescence from individual single molecules can be used to image the point‐spread‐function and spatial distribution of the fluorescence emitted in the vicinity of a metal surface. Due to the strong scattering effect, the angular distribution of the fluorescence is altered by metals, resulting in a spatial shift of fluorescence spots with respect to the metal nanostructures, and has to be taken into account in the analysis. SEF‐PALM can be used to discriminate effects of labelling density when estimating the enhancement factor in SEF. Furthermore, nanostructures with sizes below the diffraction limit can be resolved using this technique. SEF‐PALM is established as a powerful tool to study plasmon‐mediated phenomena on metal nanostructures.
A Cyano‐Bridged Vanadium–Niobium Bimetal Assembly Exhibiting a High Curie Temperature of 210 K
Authors: Imoto Kenta , Takemura Miho , Tokoro Hiroko , Ohkoshi Shin‐ichi
Published: December 2011

We report a cyano‐bridged V–Nb bimetal assembly, K0.59VII1.59VIII0.41[NbIV(CN)8]·(SO4)0.50·6.9H2O, exhibiting ferrimagnetism with a high Curie temperature (TC) of 210 K, which is the highest TC value among those of octacyano‐bridged bimetal assemblies. Such a high TC value originates from the high coordination number of octacyanoniobate and the strong superexchange interaction between VII (S = 3/2) and NbIV (S = 1/2) through the CN groups.
Tandem Reactions Leading to Benzo[c]chromen‐6‐ones and 3‐Substituted Isocoumarins
Authors: Fan Xuesen , He Yan , Cui Liangyan , Guo Shenghai , Wang Jianji , Zhang Xinying
Published: December 2011

A simple and convenient protocol for the synthesis of benzo[c]chromen‐6‐ones and 3‐substituted isocoumarins through a CuI‐catalyzed tandem reaction of 2‐bromobenzoates withcyclohexane‐1,3‐diones or acyclic 1,3‐diones is developed. This strategy can also be extended to the one‐pot synthesis of isoquinolin‐1(2H)‐one and 3,4‐dihydrophenanthridine‐1,6(2H,5H)‐dione.
Dissociable pathways facilitate theta and non‐theta states in the median raphe—Septohippocampal circuit
Authors: Crooks Robert , Jackson Jesse , Bland Brian H.
Published: December 2011

Hippocampal theta rhythms in vivo are modulated by a synchronizing projection from the medial septum (MS) and a desynchronizing input from the median raphe nucleus (MRn) of the brainstem. Inactivation of the MS suppresses theta rhythms while inactivation of the median raphe produces persistent theta. However, different pathways arise from within the MS and the median raphe and therefore different brain states could be facilitated by different forms of median raphe or septohippocampal inputs. Here, we found in urethane anesthetized rats that suppression of outputs from the MRn with procaine leads to persistent hippocampal theta as previously reported. The discharge properties of hippocampal theta‐related cells recorded during both spontaneously occurring theta and MRn 8‐OH‐DPAT‐induced theta did not differ significantly. This persistent theta was abolished by inactivation of the MS with either procaine or atropine sulfate. Selective inactivation of serotonergic median raphe outputs with the 5‐HT‐1A agonist (8‐OH‐DPAT) induced theta that was also abolished by medial septal inactivation using procaine. Thus, persistent theta following complete median raphe inactivation or selective serotonergic inactivation arises from a median raphe to MS pathway. However, 8‐OH‐DPAT infusions into the median raphe together with atropine infusions in the MS did not abolish theta activity. These data suggest that the non‐serotonergic (possibly glutamatergic) median raphe projections to the MS can facilitate the generation of hippocampal theta in the absence of medial septal cholinergic tone. These results demonstrate that dissociable neuronal pathways in the median raphe–MS–hippocampal circuit promote different brain states (theta or non‐theta) and a median raphe non‐serotonergic (likely glutamatergic) system may serve a separate function from the ascending serotonergic raphe projection in the regulation of hippocampal network activity. © 2011 Wiley Periodicals, Inc.
Hiding in plain view: Lesions of the medial temporal lobe impair online representation
Authors: Warren David E. , Duff Melissa C. , Jensen Unni , Tranel Daniel , Cohen Neal J.
Published: December 2011

The hippocampus is necessary for the normal formation of enduring declarative memories, but its role in cognitive processes spanning short intervals is less well understood. Within the last decade, several reports have described modest behavioral deficits in medial temporal lobe (MTL)‐lesion patients when they perform tasks that do not seem likely to rely on enduring memory. An intriguing but sparsely‐tested implication of such results is that the MTL is involved in the online representation of information, possibly of an associative/relational nature, irrespective of delay. We administered several tests that simultaneously presented all information necessary for accurate responses to a group of MTL‐lesion patients with severe declarative memory deficits but otherwise normal cognition, and to matched brain‐damaged and healthy comparison participants. MTL‐lesion patients performed less well than either comparison group in the Hooper Visual Organization Test, and several patients performed outside the normal range on the Overlapping Figures Test. A novel follow‐up borrowing characteristics of the Overlapping Figures Test revealed impaired identification of novel items by MTL‐lesion patients when target items were obscured by distracters, and two additional novel tests of fragmented object identification further implicated the hippocampus/MTL in the integration of information across very brief intervals. These findings suggest that MTL structures including the hippocampus contribute similarly to cognition irrespective of timescale. © 2011 Wiley Periodicals, Inc.
Metadislocations in Complex Metallic Alloys and their Relation to Dislocations in Icosahedral Quasicrystals
Authors: Feuerbacher Michael , Heggen Marc
Published: December 2011

Complex metallic alloys and quasicrystals are closely related. Both possess icosahedral local order, but while in quasicrystals the long‐range order and hence the macroscopic structure is also icosahedral, in complex metallic alloys a periodic structure with large lattice parameters is formed. Metadislocations are novel and highly complex structural defects in complex metallic alloys. Focusing on metadislocations in ε‐type phases, we will review the basic geometric concepts of metadislocations and the relation between the number of phason planes, Burgers vector, and the elastic energy. The properties of dislocations in icosahedral Al‐Pd‐Mn will briefly be recalled and discussed in relation to metadislocations.
High doses of 2,2′‐dithienyl diselenide cause systemic toxicity in rats: an in vitro and in vivo study
Authors: Chagas Pietro Maria , Bortolatto Cristiani Folharini , Wilhelm Ethel Antunes , Nogueira Cristina Wayne
Published: December 2011

Organoselenium compounds have important pharmacological properties. However, these compounds can cause toxicity, typically related to oxidation of endogenous thiols. The aim of this study was to investigate whether 2,2′‐dithienyl diselenide (DTDS) has potential toxicity in vitro and in vivo. Therefore, sulfhydryl‐containing enzyme activities, δ‐aminolevulinic acid dehydratase (δ‐ALA‐D) and Na+–K+‐ATPase were used to predict DTDS toxicity in rat brain homogenate in vitro. In in vivo experiments, a DTDS administration (50 or 100 mg kg−1, p.o.) to rats was performed and toxicological parameters were determined. DTDS inhibited δ‐ALA‐D (IC50 2 µm) and Na+–K+‐ATPase (IC50 17 µm) activities in vitro. The inhibitory effect of DTDS on δ‐ALA‐D and Na+–K+‐ATPase activities was restored by dithiothreitol. DTDS (5–25 µm) elicited a thiol oxidase‐like activity. In vivo, DTDS (50 and 100 mg kg−1) caused systemic toxicity, evidenced by a decrease in water and food intakes and body weight gain, as well as the death of rats. DTDS at the dose of 100 mg kg−1 increased plasma alanine and aspartate aminotransferase activities and decreased urea levels. At 50 and 100 mg kg−1, it increased lipid peroxidation levels. At the highest dose, DTDS inhibited δ‐ALA‐D activity. By contrast, Na+–K+‐ATPase activity and antioxidant defense were not altered in the brains of rats exposed to DTDS. In conclusion, interaction with the cisteinyl residues seems to mediate the inhibitory effect of DTDS on sulfhydryl‐containing enzymes in vitro. In addition, high oral doses of DTDS induce toxicity in rats. Copyright © 2011 John Wiley & Sons, Ltd.
Toxicokinetic modeling of folpet fungicide and its ring‐biomarkers of exposure in humans
Authors: Heredia‐Ortiz Roberto , Berthet Aurélie , Bouchard Michèle
Published: December 2011

A human in vivo toxicokinetic model was built to allow a better understanding of the toxicokinetics of folpet fungicide and its key ring biomarkers of exposure: phthalimide (PI), phthalamic acid (PAA) and phthalic acid (PA). Both PI and the sum of ring metabolites, expressed as PA equivalents (PAeq), may be used as biomarkers of exposure. The conceptual representation of the model was based on the analysis of the time course of these biomarkers in volunteers orally and dermally exposed to folpet. In the model, compartments were also used to represent the body burden of folpet and experimentally relevant PI, PAA and PA ring metabolites in blood and in key tissues as well as in excreta, hence urinary and feces. The time evolution of these biomarkers in each compartment of the model was then mathematically described by a system of coupled differential equations. The mathematical parameters of the model were then determined from best fits to the time courses of PI and PAeq in blood and urine of five volunteers administered orally 1 mg kg−1 and dermally 10 mg kg−1 of folpet. In the case of oral administration, the mean elimination half‐life of PI from blood (through feces, urine or metabolism) was found to be 39.9 h as compared with 28.0 h for PAeq. In the case of a dermal application, mean elimination half‐life of PI and PAeq was estimated to be 34.3 and 29.3 h, respectively. The average final fractions of administered dose recovered in urine as PI over the 0–96 h period were 0.030 and 0.002%, for oral and dermal exposure, respectively. Corresponding values for PAeq were 24.5 and 1.83%, respectively. Finally, the average clearance rate of PI from blood calculated from the oral and dermal data was 0.09 ± 0.03 and 0.13 ± 0.05 ml h−1 while the volume of distribution was 4.30 ± 1.12 and 6.05 ± 2.22 l, respectively. It was not possible to obtain the corresponding values from PAeq data owing to the lack of blood time course data. Copyright © 2011 John Wiley & Sons, Ltd.
Deoxyactein Isolated from Cimicifuga racemosa protects osteoblastic MC3T3‐E1 cells against antimycin A‐induced cytotoxicity
Authors: Choi Eun Mi
Published: December 2011

Deoxyactein is one of the major constituents isolated from Cimicifuga racemosa. In the present study, we investigated the protective effects of deoxyactein on antimycin A (mitochondrial electron transport inhibitor)‐induced toxicity in osteoblastic MC3T3‐E1 cells. Exposure of MC3T3‐E1 cells to antimycin A caused significant cell viability loss, as well as mitochondrial membrane potential dissipation, complex IV inactivation, ATP loss, intracellular calcium ([Ca2+]i) elevation and oxidative stress. Pretreatment with deoxyactein prior to antimycin A exposure significantly reduced antimycin A‐induced cell damage by preventing mitochondrial membrane potential dissipation, complex IV inactivation, ATP loss, [Ca2+]i elevation and oxidative stress. Moreover, deoxyactein increased the activation of PI3K (phosphoinositide 3‐kinase), Akt (protein kinase B) and CREB (cAMP‐response element‐binding protein) inhibited by antimycin A. All these data indicate that deoxyactein may reduce or prevent osteoblasts degeneration in osteoporosis or other degenerative disorders. Copyright © 2011 John Wiley & Sons, Ltd.
Determination of Cadmium and Lead in Human Teeth Samples Using Dispersive Liquid‐liquid Microextraction and Graphite Furnace Atomic Absorption Spectrometry
Authors: Zhang Chunyan , Wang Yining , Cheng Xiangrong , Xia Haibin , Liang Pei
Published: December 2011

A new method for the determination of cadmium and lead in human teeth was developed based on dispersive liquid‐liquid microextraction preconcentration and graphite furnace atomic absorption spectrometry determination. In the proposed approach, O,O‐diethyldithiophosphate (DDTP) was used as a chelating agent, and carbon tetrachloride and methanol were selected as extraction and dispersive solvents. Some factors influencing the extraction efficiency of cadmium and lead and their subsequent determination, including extraction and dispersive solvent type and volume, pH of sample solution, concentration of the chelating agent and extraction time, were studied and optimized. Under the optimum conditions, the enrichment factor of 116 and 68 for cadmium and lead were achieved. The detection limit for cadmium and lead was 5.6 and 45 ng L−1, and the relative standard deviation (R.S.D) was 4.5% and 3.8% (n = 7, c = 1.0 ng mL−1), respectively. Verification of the accuracy of the method was carried out by analysis of a standard reference material (NIST 1486, bone meal). The method was successfully applied to the determination of trace amount of cadmium and lead in human teeth samples with satisfactory results.
Synthesis of novel pyrazolo[3,4‐d]pyrimidines peri‐fused with 1,4‐diazepine, 1,4‐thiazepine, and 1,2,4‐triazepine rings
Authors: Masevicius Viktoras , Juskenas Robertas , Tumkevicius Sigitas
Published: December 2011

A simple and efficient synthesis of novel ortho‐ and peri‐annulated heterocyclic systems—2,6,7,9‐tetrahydro‐8H‐pyrazolo[5,4,3‐de]pyrimido[4,5‐e][1,4]diazepine, 2,6,7,9‐tetrahydro‐8H‐pyrazolo[5,4,3‐de]pyrimido [5,4‐f][1,4]thiazepine, and 6,9‐dihydro‐2H‐pyrazolo[3,4,5‐ef]pyrimido[5,4‐f][1,2,4]triazepine is described. J. Heterocyclic Chem.,, (2012).
1,3‐dipolar cycloaddition reactions of 2‐substituted azomethine N‐oxides with N‐benzyl maleimides leading to the synthesis of stereoisomers
Authors: Badru Rahul , Shah Sakshi , Singh Baldev
Published: December 2011

The azomethine N‐oxides (1) on reacting with N‐benzylmaleimide (2) provide a mixture of stereoisomers 2,3‐diphenyl‐5‐benzyl‐4H‐2,3,3a,5,6,6a‐hexahydropyrrolo[3,4‐d]isoxazole‐4,6–dione derivatives (3) in good yields. These isomers have been assigned cis and trans configurations (3‐A and 3‐B) with respect to proton C3‐H on the azomethinic carbon on the basis of their PMR and H‐NMR COSY data. The ratio between cis and trans isomers has been found to be dependent on substituents present at ortho position of C‐phenyl aldehydic moiety. The salient feature of these 1,3‐dipolar cycloaddition reactions lies in that the benzylic protons on N‐benzyl moiety suffer gem coupling, indicating magnetic nonequivalence. J. Heterocyclic Chem.,, (2012).
Determination of the volatiles from tobacco by capillary gas chromatography with atomic emission detection and mass spectrometry
Authors: Li Gang , Wu Da , Wang Ye , Xie Wenyan , Zhang Xiangmin , Liu Baizhan
Published: December 2011

A new gas chromatograph‐atomic emission detector (GC‐AED) coupled with Deans switching technique for analyzing volatiles from tobaccos were developed. The detector operating parameters (reagent gas pressure and make‐up gas flow rate) were optimized. The detection limits for the elements carbon (193 nm), hydrogen (486 nm) and oxygen (171 nm) ranged 0.05–0.2, 0.05–0.3 and 1–11 ng, respectively, depending on the compound. The sensitivity and linearity for the elements carbon (193 nm), hydrogen (486 nm) and oxygen (171 nm) decreased in the order O>H>C. Calibration curves were obtained by plotting peak area versus concentration, and the correlation coefficients relating to linearity were at least 0.9359. Elemental response factors measured on these channels, relative to the carbon 193‐nm channel, were hydrogen, 0.38–0.48 (mean %RSD=5.64), and oxygen, 0.085–0.128 (mean %RSD=14.9). The evaluation was also done for the new technique and for an established GC‐MS technique for the same real samples. The results of GC‐AED and GC‐MS showed that there was a relatively good agreement between the two sets of data.
Detection of L‐phenylalanine using molecularly imprinted solid‐phase extraction and flow injection electrochemiluminescence
Authors: Lu Juanjuan , Ge Shenguang , Wan Fuwei , Yu Jinghua
Published: December 2011

A novel flow injection electrochemiluminescence method combined with molecularly imprinted solid‐phase extraction was developed for the determination of L‐phenylalanine, in which ${\rm{Ru(bpy}})_3^{2 + }$ was used as the luminophor and indium tin oxide glass was modified as the working electrode. Molecularly imprinted polymers, synthesized by self‐assembly with functional monomer and crossing linker, were used for the selective extraction of L‐phenylalanine. In order to overcome the drawbacks of traditional electrochemiluminescence cells such as high IR drop, high over‐potential and so on, a novel electrochemiluminescence cell was developed. The enhanced electrochemiluminescence intensity was linearly related with the concentration of L‐phenylalanine in the range from 1.0×10−7 to 5.0×10−5 g/mL with a detection limit of 2.59×10−8 g/mL. The relative standard deviation for the determination of 1.0×10−6 g/mL L‐phenylalanine was 1.2% (n=11). The method showed higher sensitivity and good repeatability, and was successfully applied for the determination of L‐phenylalanine in egg white, chicken and serum samples. A possible mechanism for the enhanced electrochemiluminescence response on indium tin oxide glass is proposed.
The definition of the V zone for the safety space of functional surgery of the tongue
Authors: Hou Tiening , Shao Jinyan , Fang Songhua
Published: December 2011

Objectives/Hypothesis:

To define safety space for functional surgery of the tongue.

Study Design:

Prospective nonrandomized study.

Methods:

Computed tomographic angiography of the lingual artery was performed in 107 in‐patients with obstructive sleep apnea syndrome and 17 controls. The safety space was ascertained according to the course of lingual artery.

Results:

The course of the lingual artery, termed the Big Dipper bowl of the tongue, was similar in each group. The tissue above the lingual artery and the vacuity of the hypoglossal/lingual artery neurovascular bundle (HLNVB) formed a three‐dimensional structure. The anterior part was named the V prozone. Its anterior border was the tangent plane of the deep lingual artery, its posterior border the circumvallate papilla, its width the interval of bilateral margins at the corresponding parts of the tongue, and its height the level of the middle lingual frenulum. The posterior portion between the bilateral dorsal arteries in the tongue base was named the V postzone. Its width was 31.42 ± 3.82 mm when the tongue was in a resting position, and its height was the distance from the foramen cecum to the bottom of the epiglottic vallecula. The inferior part under the intrinsic lingual muscles was named the hypoglossal floor. It is a relatively restricted surgery zone.

Conclusions:

The V zone of the tongue without HLNVB travelling provides enough of safety space for functional surgery on the tongue.Laryngoscope, 122:66–70, 2012
Standardized letter of recommendation for pediatric fellowship selection
Authors: Prager Jeremy D. , Perkins Jonathan N. , McFann Kim , Myer Charles M. , Pensak Myles L. , Chan Kenny H.
Published: December 2011

Objectives/Hypothesis:

To develop a pediatric otolaryngology fellowship selection standardized letter of recommendation (SLOR).

Study Design:

SLOR and narrative letter of recommendation (NLOR) comparison study.

Methods:

An SLOR was created to investigate qualities desired in fellows using five content‐based categories: writer background, comparison of the applicant to contemporaries and predecessors, applicant's qualifications for pediatric otolaryngology, a global assessment of the applicant, and a summary statement about the applicant. In phase I, the SLORs were completed, including writing time, by the applicant's pediatric otolaryngology chief. In phase II, letters were ranked on Likert‐type scales for the content‐based categories, reviewer's overall ranking, and ease of review by six otolaryngologists. Reviewers recorded time needed to review each letter.

Results:

Nineteen SLORs (73%) were collected. Mean writing time was 8.84 ± 3.87 minutes. Interrater reliability was higher on the SLORs in the content‐based sections and the overall ranking. Ranking times were lower on the SLORs. Mean and median rankings were higher on the SLORs for writer background, comparison of the applicant to contemporaries and predecessors, applicant's qualifications for pediatric otolaryngology, and ease of review; mean global assessment of the applicant, summary statement about the applicant, and overall rankings were lower on the SLORs.

Conclusions:

To our knowledge, this is the first inquiry using an SLOR developed for otolaryngology. SLORs are an alternative to NLORs for fellowship selection that offers improved reliability and efficiency. Further investigation using SLORs in otolaryngology residency selection is merited.
Methods of detailed thermal fatigue evaluation of nuclear power plant components
Authors: Rudolph J. , Bergholz S. , Willuweit A. , Vormwald M. , Bauerbach K.
Published: December 2011

The fatigue check of components has to be considered as an essential module of the safety concept as well as the ageing and lifetime management of nuclear power plants. It is based on special safety requirements in the design phase as well as in the framework of the ageing and lifetime management. Considerable efforts of load identification (fatigue monitoring) as well as the strict code conformity are characteristic features. The predominance of thermal cyclic loadings as well as relevant stress/strain amplitudes in the low cycle fatigue regime (LCF) are peculiarities compared to other technical domains. The code based fatigue concept is explained in the first part of the contribution. Furthermore, potentials for the quantification of existing margins are shown. On this, a new approach of mechanistic simulation of the thermal cyclic fatigue process based on short crack fracture mechanics is described in detail in the second part.
Prospective high‐resolution respiratory‐resolved whole‐heart MRI for image‐guided cardiovascular interventions
Authors: Kolbitsch Christoph , Prieto Claudia , Buerger Christian , Harrison James , Razavi Reza , Smink Jouke , Schaeffter Tobias
Published: December 2011

Cardiovascular diseases, including arrhythmias and heart failure, are commonly treated with percutaneous procedures guided by X‐ray fluoroscopy. The visualization of the targeted structures can be enhanced using preacquired respiratory‐resolved anatomic data (dynamic roadmap), which is displayed as an overlay onto X‐ray fluoroscopy images. This article demonstrates how dynamic roadmaps using an affine motion model can be obtained from one respiratory‐resolved three‐dimensional whole‐heart acquisition using the previously introduced Radial Phase Encoding‐Phase Ordering with Automatic Window Selection method. Respiratory motion in different regions of the heart was analyzed in 10 volunteers, and it was shown that the use of dynamic roadmaps can reduce misalignment errors from more than 10 down to less than 1.5 mm. Furthermore, the results suggest that reliable motion information can be obtained from highly undersampled images due to the advantageous undersampling properties of the radial phase encoding trajectory. Finally, results of a three‐dimensional dynamic roadmap obtained from a patient before catheter ablation for atrial fibrillation treatment are presented. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Utilizing echo‐shifts in k‐space for generation of positive contrast in areas with marked susceptibility alterations
Authors: Eibofner Frank , Steidle Günter , Kehlbach Rainer , Bantleon Rüdiger , Schick Fritz
Published: December 2011

A technique for generation of positive contrast near susceptibility alterations utilizing echo‐shifts in k‐space is introduced, based on altered Larmor‐frequencies and resulting phase‐shifts accumulating during the echo‐time at the site of local magnetic field gradients. 3D gradient‐echo raw‐data is acquired and weighted with an inverse Hanning filter. The filter partly suppresses central raw‐data points, while maintaining outer areas. Reconstruction of the filtered raw‐data results in images where pixels with apparent magnetic field gradients are highlighted against homogeneous pixels. Further processing steps are introduced to remove remaining intensities in the homogeneous parts of the filtered image. Feasibility is shown by an agar phantom containing magnetically labeled cells, with concentrations of 25, 50, 100, and 250 cells/μL, and by images of the human head. The technique allows detection of echo‐shifted pixels with automatic suppression of magnetically homogeneous parts while keeping post‐processing time short. Fewer than four labeled cells per pixel were clearly displayed with positive contrast. Application to the human head shows bright veins and complete suppression of homogeneous regions. The presented technique has high potential for specific detection of low concentrations of labeled cells or susceptibility altered regions in vivo with positive contrast, whereas areas with low spin density are not highlighted. Magn Reson Med, 2012. © 2011 Wiley Periodicals, Inc.
Activation of Akt is associated with poor prognosis and chemotherapeutic resistance in pediatric B‐precursor acute lymphoblastic leukemia
Authors: Morishita Naoto , Tsukahara Hirokazu , Chayama Kosuke , Ishida Toshiaki , Washio Kana , Miyamura Takako , Yamashita Nobuko , Oda Megumi , Morishima Tsuneo
Published: December 2011

Background

Activation of the phosphoinositide 3‐kinase (PI3K)/Akt pathway, a pro‐survival pathway, plays important roles in tumor cell growth. However, the role of Akt in the pathogenesis of pediatric B‐precursor acute lymphoblastic leukemia (B‐pre ALL) remains to be clarified. This study was undertaken to explore the clinical relevance and molecular mechanisms underlying the activation of Akt (i.e., phosphorylated Akt, P‐Akt) in pediatric B‐pre ALL.

Procedure

We evaluated the activation status of Akt in bone marrow samples from 21 children with newly diagnosed B‐pre ALL and correlated the expression level of P‐Akt with clinicopathologic and prognostic features. Additionally, we transfected the myristoylated Akt cDNA into the B‐pre ALL cell line, Nalm‐6, and examined the effect, in vitro, of Akt activation on the response to antitumor drugs.

Results

P‐Akt expression in B‐pre ALL blast cells at diagnosis was associated significantly with poor response to induction chemotherapy including prednisolone, dexamethasone, vincristine, and adriamycin in B‐pre ALL patients. Both overall survival and relapse‐free survival in patients with P‐Akt expression were reduced significantly more than in patients without P‐Akt expression. Activation of Akt reduced the extent of apoptosis induced by the antitumor drugs in Nalm‐6 listed above. Activation of Akt did not induce expression of P‐glycoprotein, a drug transporter that is capable of conferring multidrug resistance.

Conclusion

These results support the contention that Akt activation is a mechanism of chemotherapeutic resistance in B‐pre ALL and suggest that Akt can be a therapeutic target for the treatment of relapsed or refractory pediatric B‐pre ALL. Pediatr Blood Cancer 2012; 59: 83–89. © 2011 Wiley Periodicals, Inc.
Long‐term outcome of hypothalamic pituitary tumors in Langerhans cell histiocytosis
Authors: Fahrner Bernhard , Prosch Helmut , Minkov Milen , Krischmann Martha , Gadner Helmut , Prayer Daniela , Grois Nicole
Published: December 2011

Background

Hypothalamic‐pituitary (HP) disease is the most common CNS manifestation of Langerhans cell histiocytosis (LCH) frequently leading to diabetes insipidus (DI) and anterior pituitary hormone deficiencies (APD). On MRI, loss of the normal posterior pituitary signal and thickening of the pituitary stalk have been described, as well as neurodegenerative signal changes associated with neuropsychological disabilities in some patients. The influence of therapy on the long‐term course of HP tumors and neurodegeneration (ND) is not well‐understood.

Procedure

In this retrospective survey we focused on patients with LCH and HP disease with clinical and MRI data available at diagnosis of HP disease and at least three follow up investigations. We collected clinical and MRI follow‐up information for central review and analysis.

Results

We identified 22 patients with HP tumors (HPT) registered at the LCH study center. Many different treatment regimens were applied for variable periods, with more than one regimen in most patients. Regression of the tumor was seen in the majority, but all patients had APD or ND on MRI at last follow up. In none of the patients APD and ND regressed or resolved. A deterioration of radiological ND was noted in 17 patients leading to overt clinical neuropsychological impairment in five.

Conclusions

Patients with HPT appear to be at high risk to develop permanent neuroendocrine consequences. Coordinated studies for patients with LCH and HP disease including thorough MRI monitoring and neuropsychological tests are needed. Pediatr Blood Cancer 2012; 58: 606–610. © 2011 Wiley Periodicals, Inc.
Differential Effects of Chlorogenic Acid on Various Immunological Parameters Relevant to Rheumatoid Arthritis
Authors: Chauhan Prashant Singh , Satti Naresh Kumar , Sharma Punita , Sharma Vijay Kumar , Suri Krishan Avtar , Bani Sarang
Published: December 2011

Despite chlorogenic acid (CGA) being widely present in nature, particularly in the human diet, there is very little information regarding its pharmacological activities. The present investigation was carried out to investigate the antiarthritic activities of this compound in adjuvant induced‐arthritis in male Wistar rats, and to explore the underlying mechanisms of actions in view of immunological responses. We observed that CGA effectively controlled the total (CD3) and differentiated (CD4 and CD8) T cells count at the dose of 40 mg/kg. We also assessed the effect on co‐stimulatory molecules (CD28, CD80/86) and found that CGA efficiently suppressed CD80/86 but failed to bring any changes in the CD28 count, whereas ibuprofen (standard drug) resulted in highly significant inhibition of both. We next examined the effect on CD4+ T cells specific Th1/Th2 cytokines by flow cytometry and observed that CGA suppressed the Th1 cytokines in a highly significant manner but elevated Th2 cytokines with dose dependence. Results of the present investigation suggest that CGA is a potent antiarthritic agent. Copyright © 2011 John Wiley & Sons, Ltd.
Degradation mechanisms occurring in precious metallic artefacts
Authors: Angelini E. , de Caro T. , Mezzi A. , Riccucci C. , Faraldi F. , Grassini S.
Published: December 2011

Since ancient times, precious metallic artefacts have gained a remarkable interest from a historical, artistic and economical point of view. They were used as jewels or artistic items but also for currency, medium of exchange and form of saving, and in many cases were manufactured with a high level of technological competence. Several Roman and Phoenician–Punic gold, silver and copper‐based, gold and silver‐plated artefacts characterised by a wide compositional range and different metallurgical nature have been studied to identify the microchemical surface structure and the metallurgical features. Four case studies are reported. The investigation was carried out by means of the combined use of surface and microanalytical techniques, such as XPS, X‐ray diffraction and SEM equipped with an energy dispersive X‐ray spectrometer. The results revealed that the artefacts surface is characterised by a thin layer of insoluble corrosion products like AgCl, Ag2S or AgCuS, CuS, Cu2O, Pb or Cu‐carbonates mixed to form a complex composite structure. The presence and the concentrations of these corrosion compounds is strongly related to the archaeological context. The overall experimental findings confirm that the nearly pure gold artefacts and the gold‐based artefacts are more stable with respect to the silver ones where the ubiquitous presence of chlorides is often found. The microchemical and micromorphological characterization allows to identify the plating and manufacturing techniques. Several methods were used by the craftsmen, including fire gilding, a highly complex and sophisticated method based on the use of mercury. Finally, the proposed approach may help, when feasible, to preserve, restore and protect the artefacts without causing further damaged. Copyright © 2011 John Wiley & Sons, Ltd.
Dynamics of supervision
Authors: Scheuermann Tom
Published: December 2011

This chapter introduces research and resources that can support supervisors in working with employees during challenging financial times. The author provides a broad overview of issues that are influencing the higher education and current environment for supervisors.
Supervising graduate assistants
Authors: White Jessica , Nonnamaker John
Published: December 2011

This chapter describes the nuances, challenges, and rewards of supervising graduate assistants in student affairs master's programs.
Design and seismic response of tall chevron panel buckling‐restrained braced steel frames
Authors: Ding Yukun , Zhang Yaochun
Published: December 2011

The numerical analysis of the seismic performance for tall chevron panel buckling‐restrained braced steel frames (PBRBFs) under small and strong earthquake excitations has been carried out to investigate a capacity design procedure for chevron PBRBFs and to examine the effects of axial strength distribution of braces along the height of buildings, vertical supports of braces for the braced beams and the overstrength of braces on the seismic response of PBRBFs. It revealed that the chevron braces that remained elastic can actually provide the vertical supports for the braced beams. Under severe earthquake excitations, the vertical supports deteriorated greatly after braces yielding. The PBRBFs designed by omitting vertical supports of braces for the braced beams and considering the overstrength of braces exhibited superior performance with smaller plastic deformations for braced beams and reduction in ductility demands for panel buckling‐restrained braces (PBRBs) as compared with the others. The distribution of yielding for PBRBs in 10‐story buildings verified that the participation from the higher modes is not very remarkable and that the capacity design based on the first‐mode response can be considered for multistory PBRBFs. Moreover, on the basis of the analysis results of the 30‐story PBRBF, the participation of the higher modes should be taken into account for high‐rise PBRBFs. Copyright © 2011 John Wiley & Sons, Ltd.
Isolation and Characterization of CH3OC(O)OOC(O)F from the Reaction CH3OH + FC(O)OOC(O)F
Authors: Berasategui Matias , Burgos Paci Maximiliano A. , Argüello Gustavo A.
Published: December 2011

The synthesis of CH3OC(O)OOC(O)F is accomplished by the thermal reaction between CH3OH and FC(O)OOC(O)F at room temperature. The new peroxide is obtained in pure form after repeated trap‐to‐trap condensation and it is characterized by NMR and IR spectroscopy and mass spectrometry. Geometrical parameters were studied by ab initio methods [B3LYP/6‐31++G(d, p)]. CH3OC(O)OOC(O)F is stable for a few hours at room temperature, and it decomposes into CO2, CO, HF, HC(O)OH, and CH2O.The boiling point is extrapolated to 366.5 K from the vapor pressure curve log p = 8.623–2061/T (p /mbar, T /K). The mechanisms for both the formation and thermal decomposition of CH3OC(O)OOC(O)F are discussed, and some physicochemical properties are compared with those of related compounds.
Viscous Marangoni propulsion
Authors: Lauga Eric , Davis Anthony M. J.
Published: December 2011

Marangoni propulsion is a form of locomotion wherein an asymmetric release of surfactant by a body located at the surface of a liquid leads to its directed motion. We present in this paper a mathematical model for Marangoni propulsion in the viscous regime. We consider the case of a thin rigid circular disk placed at the surface of a viscous fluid and whose perimeter has a prescribed concentration of an insoluble surfactant, to which the rest of its surface is impenetrable. Assuming a linearized equation of state between surface tension and surfactant concentration, we derive analytically the surfactant, velocity and pressure fields in the asymptotic limit of low capillary, Péclet and Reynolds numbers. We then exploit these results to calculate the Marangoni propulsion speed of the disk. Neglecting the stress contribution from Marangoni flows is seen to over-predict the propulsion speed by 50 %.
Antioxidant and anti-inflammatory effect of conjugated linolenic acid isomers against streptozotocin-induced diabetes
Authors: Saha Siddhartha S. , Ghosh Mahua
Published: December 2011

The present study was undertaken to evaluate the effect of α-eleostearic acid and punicic acid, two isomers of conjugated linolenic acid (CLnA) present in bitter gourd (Momordica charantia) and snake gourd oil (Trichosanthes anguina), respectively, against oxidative stress, inflammatory challenge and aberration in erythrocyte morphology due to streptozotocin (STZ)-induced diabetes. Male albino rats were divided into four groups consisting of eight animals in each group. The first group served as control and diabetes was induced in rats in groups 2–4 by a single intraperitoneal injection of STZ. Moreover, rats in groups 3 and 4 were treated with 0·5 % of α-eleostearic acid and 0·5 % of punicic acid of the total lipid given, respectively, by oral administration once per d. After administration, CLnA isomers had significantly reduced oxidative stress, lipid peroxidation and restored antioxidant and pro-inflammatory enzymes such as superoxide dismutase, catalase, and glutathione peroxidase, reduced glutathione, NO synthase level in pancreas, blood and erythrocyte lysate. The ferric reducing antioxidant power (FRAP) assay of plasma showed that CLnA treatment caused improvement in the FRAP value which was altered after STZ treatment due to an increased level of free radicals. Expression of inflammatory cytokines such as TNF-α and IL-6 in blood and expression of hepatic NF-κB (p65) increased significantly after STZ treatment due to increased inflammation which was restored with the administration of CLnA isomers. From the obtained results, it could be concluded that α-eleostearic acid and punicic acid showed potent antioxidant and anti-inflammatory activity with varying effectivity.
Pathology of enteric infections induced by the acanthocephalanProfilicollis chasmagnathiin Olrog's gull,Larus atlanticus, from Argentina
Authors: La Sala L.F. , Perez A.M. , Smits J.E. , Martorelli S.R.
Published: December 2011

Acanthocephalans can be pathogenic helminths of marine birds. Every year during the breeding season, there is variable mortality among prefledged chicks from the largest known Olrog's gull (Larus atlanticus) colony. Mortality has been associated with infection by the acanthocephalanProfilicollis chasmagnathi. Our aim was to study the role of chicks' size as a risk factor for intensity of infection and severe pathology, and to expand upon previous pathological findings reported in acanthocephalan-infected chicks. Size of the chick was associated with intensity of infection and number of intestinal perforations, which increased by 6.9% and 4.1%, respectively, for each millimetre increment in chick size. Infection was associated with inflammatory enteritis and granulomatous peritonitis. Complete intestinal perforations were observed in 85% and 97.3% of the studied chicks in 2005 and 2006, respectively, and they were observed very early during the post-hatching period. Our results show: (1) the presence of advanced pathology associated with acanthocephalan infections in chicks, beginning very early in the post-hatching period; and (2) significant increases in the intensity of infection and the associated pathology as a function of size of chicks, in dead chicks during this period.
Bilateral fungiform papilloma with synchronous verrucous carcinoma of the nasal septum: a rare presentation and a literature review
Authors: Maithani T , Dey D , Pandey A , Chawla N
Published: December 2011

Aim:

Fungiform papillomas are benign mucosal neoplasms presenting as a unilateral exophytic mass involving the anterior portion of the nasal septum. In this study, we present an exceptional case of a bilateral fungiform papilloma with a synchronous verrucous carcinoma of the nasal septum.

Material and methods:

A case study with a review of the literature concerning malignant changes in fungiform papilloma.

Results:

The general consensus in most of the literature is that malignant change in fungiform papilloma is exceptional. Our patient is probably the third reported case of verrucous carcinoma of the nasal septum, and the first report of a bilateral fungiform papilloma with a synchronous verrucous carcinoma. The tumour was subjected to complete surgical removal in the first instance. There was no recurrence at follow up seven months after surgery.

Conclusion:

Although fungiform papillomas are generally not premalignant, occasional malignant transformation may occur. Thus, they must be managed with the utmost cautiousness.
The role of morphophonological regularity in young Spanish-speaking children's production of gendered noun phrases
Authors: LINDSEY BRITTANY A. , GERKEN LOUANN
Published: December 2011

Adult Spanish speakers generally know which form a determiner preceding a noun should have even if the noun is not in their lexicon, because Spanish demonstrates high predictability between determiner form and noun form (la noun-a and el noun-o). We asked whether young children learning Spanish are similarly sensitive to the correlation of determiner and noun forms, or whether they initially learn determiner–noun pairings one-by-one. Spanish–English bilingual children and adults repeated Spanish words and non-words preceded by gender congruous and incongruous determiners. If children learn determiner–noun pairings one-by-one, they should show a gender congruity effect only for words. In contrast with this prediction, both children and adults demonstrated congruity effects for words and non-words, indicating sensitivity to correlated morphophonological forms. Furthermore, both age groups showed more facility in producing phrases with nouns ending in -a, which are more frequent and predictable from the preceding determiner.