bluuebunny/crossref_metadata_2025 huggingface dataset:
Enantioselective Recognition of Dopa Enantiomers in the Presence of Ascorbic Acid or Tyrosine
Authors: Han Qian , Chen Qiao , Wang Yonghua , Zhou Juan , Fu Yingzi
Published: December 2011

A simple sensor was obtained through N‐isobutyryl‐L‐(D)‐cysteine enantiomers self‐assembled monolayer. It was demonstrated that the N‐isobutyryl‐cysteine modified gold electrodes can enantioselectively recognize 3,4‐dihydroxyphenylalanine (dopa) enantiomers. The electrocatalytic behaviors of enantiomers were analyzed with cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Selectivity of the chiral surface was estimated by investigating two mixture enantiomers (dopa‐ascorbic acid and dopa‐tyrosine), it certified that the sensor was only satisfactorily used to specific recognize dopa enantiomers. The possible mechanism for the enantioselective recognition was discussed.
Development of a Catalase‐Based Amperometric Biosensor for the Determination of Increased Catalase Content in Milk Samples
Authors: Fűtő Péter , Markus Gabriella , Kiss Attila , Adányi Nóra
Published: December 2011

The aim of our work was to develop a selective amperometric biosensor for infected milk detection. The catalase enzyme (EC 1.11.1.6) was immobilized onto the surface of a thin‐layer enzyme cell. The measurements were carried out in stopped‐flow injection analysis system (0.8 mL min−1 flow rate, +590 mV polarization potential) in organic phase (6 % sodium acetate buffer 200 mM pH 6.0, ferrocene conductive salt (7.5 mg L−1) dissolved in acetonitrile. A certain amount of hydrogen peroxide was degraded by the catalase content of the milk. The degradation of the hydrogen peroxide is proportional to the infection of the milk samples.
Iron Ion Sensor Based on Functionalized ZnO Nanorods
Authors: Khun Kimleang , Ibupoto Zafar Hussain , Ali Syed Muhammad Usman , Chey Chan Ouern , Nur Omer , Willander Magnus
Published: December 2011

In this work, we are presenting an iron ion (Fe3+) potentiometric sensor based on functionalized ZnO nanorods with selective ionophore (18 crown 6). Zinc oxide nanorods with a diameter of about 100 to 150 nm and 1 µm in length were grown on gold coated glass. The selective Fe3+ ionophore sensor with highly aligned ZnO nanorods showed high sensitivity, acceptable selectivity, reproducibility and a stable signal response for detecting Fe3+. The potentiometric response of the Fe3+ sensor with functionalized ZnO nanorods versus a Ag/AgCl reference electrode was observed to be linear over a logarithmic concentration range from 10−5 M to 10−2 M. The detection limit of the proposed sensor was about 5 µM, which is lower than the normal blood concentration of Fe3+ which is about 10 µM and can be up to 30 µM. The sensitivity of the proposed Fe3+ sensor was found to be 70.2±2.81 mV/decade with a regression coefficient R2=0.99 and a response time less than 5 s. The functionalized ZnO nanorods sensor with selective iron ionophore has a life time greater than one month and has shown insignificant interference with other ions usually present in the human blood serum. The proposed sensor was used as an indicator electrode for potentiometric titration.
Bismuth‐Coated Mesoporous Platinum Microelectrodes as Sensors for Formic Acid Detection
Authors: Daniele Salvatore , Bragato Carlo , Battistel Dario
Published: December 2011

Mesoporous platinum microeletrodes (MPtEs) modified by sub‐monolayers of irreversibly adsorbed bismuth (Bi‐MPtE) were investigated for their potential use as sensors for the detection of formic acid in direct formic acid fuel cells. The mesoporous platinum films were prepared by electrodeposition of platinum on Pt microdisks substrates 25 μm diameter, from hexachloroplatinic acid dissolved in the aqueous domain of the lyotropic liquid crystalline phase of octaethylene glycol monohexadecyl ether. The roughness factor (RF) of the MPtEs was about two orders of magnitude greater than those of the corresponding polished microelectrodes. Bismuth ad‐atoms onto the platinum surface were deposited by under potential deposition from 1 mM Bi3+ ions in 0.5 M H2SO4 solutions. The catalytic activity of a series of Bi‐MPtEs, characterized by different roughness and fractional bismuth coverage (θBi), towards the oxidation of HCOOH, was investigated by cyclic voltammetry and potential step experiments. Compared to MPtEs, Bi‐MPtEs displayed enhanced electrooxidation currents at lower potentials. The stability of irreversibly adsorbed bismuth, and consequently the Bi‐MPtEs catalytic activity, was found to depend on the high potential limit employed in the measurements. In general, both electrode stability and electrocatalytic performance were good, provided that the operational potential was kept ≤0.4 V vs. Ag/AgCl. Bi‐MPtEs with θBi>0.3 provided almost sigmoidal shaped waves with low hysteresis, as those expected for microelectrodes working under steady state. The effect of concentration of HCOOH was investigated over the range 0.01–5 M, and linearity between current and concentration depended on both roughness factor and bismuth coverage. A Bi‐MPtE characterised by RF=210 and θBi≥0.6 provided linearity up to 2 M of formic acid. Reproducibility of the sensors was within 2 % (RSD). The same sensor, under the optimized experimental conditions, could be employed for at least two months with negligible loss of the initial performance.
Rapid and efficient protein enzymatic digestion: An experimental comparison
Authors: Dycka Filip , Bobal Pavel , Mazanec Karel , Bobalova Janette
Published: December 2011

The major objective of proteomics is to identify and examine the large numbers of proteins extracted from complex biological systems. This is generally achieved by combining various techniques of protein separation with a mass spectrometric analysis of proteins that are digested enzymatically. Recently, several alternatives to this standard protocol have been developed for efficient and fast protein digestion. One option is the use of modified trypsin instead of native trypsin for the in‐gel digestion of proteins. Microwave, ultrasonic‐assisted protein enzymatic digestion and proteolysis accelerated by infrared radiation are other suitable alternatives. The application of the variable performance of the fast enzymatic digestion of proteins by using different techniques is reported here. The advantage of these methods is to have the ability to detect proteins in a shorter span of time. For example, using alternative protein digestion takes only minutes, in contrast to the several hours required by conventional methods. To demonstrate the suitability of this fast procedure, the digestion of carbonic anhydrase, bovine serum albumin, lysozyme and proteins extracted from plants (Hordeum vulgare, Arabidopsis thaliana) were used. Considering that the required reaction time for the conventional method is much longer, these applied methodic approaches tend to give in‐gel digestion a much higher efficiency rating. This study examines the fast, efficient and low‐cost proteolytic strategies for the digestion process, and for protein identification based on the use of ultrasound and infrared technology. In addition, comparisons of the applied techniques were studied. Several differences were found, suggesting the potential use of proteolysis accelerated by infrared radiation.
In situ demonstration and quantitative analysis of the intrinsic properties of glycoside hydrolases
Authors: Zhang Xiaomei , Liu Ning , Yang Fan , Li Jinghua , Wang Lushan , Chen Guanjun , Gao Peiji
Published: December 2011

Based on digital image analysis techniques and a series of optimizations in native electrophoresis, a new direct method to simultaneously detect the intrinsic properties of each active component in the enzymatic system of glycoside hydrolase was established. The key technique is that the concentration changes of substrate (or product) on the gel can be determined quantitatively by the gray value changes of the corresponding band after electrophoretic separation. In this manner, the catalytic characteristics of each glycoside hydrolase component were demonstrated in situ and were easily determined after immersing the gel in a series of solutions containing substrates or their derivatives. Because of its high throughput, great sensitivity, and convenient operation, this method can be used to demonstrate the natural diversity of glycoside hydrolases and to study spatial and temporal regulation in multienzyme expression systems. Thus, it is an effective approach to study the functional proteomics of glycoside hydrolases.
MicroRNA therapeutics in cardiovascular medicine
Authors: Thum Thomas
Published: December 2011

Cardiovascular diseases are the most common causes of human morbidity and mortality despite significant therapeutic improvements by surgical, interventional and pharmacological approaches in the last decade. MicroRNAs (miRNAs) are important and powerful mediators in a wide range of diseases and thus emerged as interesting new drug targets. An array of animal and even human miRNA‐based therapeutic studies has been performed, which validate miRNAs as being successfully targetable to treat a wide range of diseases. Here, the current knowledge about miRNAs therapeutics in cardiovascular diseases on their way to clinical use are reviewed and discussed.
Catchment lithology as a major control on alluvial megafan development, Kohrud Mountain range, central Iran
Authors: Arzani Nasser
Published: December 2011

The relative importance of tectonics, climate, base level and source lithology as primary factors on alluvial‐fan evolution, fan morphology and sedimentary style remain in question. This study examines the role of catchment lithology on development and evolution of alluvial megafans (>30 km in length), along the flanks of the Kohrud Mountain range, NE Esfahan, central Iran. These fans toe out at axial basin river and playa‐fringe sediments towards the centre of basin and tectonics, climatic change and base‐level fluctuations, were consistent for their development. They formed in a tectonically active basin, under arid to semiarid climate and a long term (Plio‐Pleistocene to Recent) change from wetter to drier conditions. The key differences between two of these fans, Soh and Zefreh fans, along the west and south flanks of this mountain range, is that their catchments are underlain by dissimilar bedrock types. The source‐area lithologies of the Soh and Zefreh fans are in sedimentary and igneous terrains, respectively, and these fans developed their geometry mainly in response to different weathering intensities of their catchment bedrock lithologies. Fan surface mapping (based on 1/50000 topographic maps, satellite images, and fieldwork), reveals that the geomorphic evolution of these fans differs in that the relatively large‐scale incision and through trenching of the Soh fan is absent in the Zefreh fan. Whereas the limited sediment supply of the Soh fan has resulted in a deep incised channel, the Zefreh fan has remained aggradational with little or no trenching into proximal to medial fan surface due to its catchment bedrock geology, composed mainly by physically weathered volcaniclastic lithology and characterized by high sediment supply for delivery during episodic flash floods. Sediment supply, which is mainly a function of climate and source lithology, is a dominant driver behind the development of fan sequences in alluvial megafans. Copyright © 2012 John Wiley & Sons, Ltd.
Die Maschine von Bohnenberger: 200. Geburtstag des kardanisch gelagerten Kreisels
Authors: Wagner Jörg F. , Trierenberg Andor
Published: December 2011

Im Jahr 2004 wurde in der Physiksammlung des Kepler‐Gymnasiums Tübingen ein kardanisch gelagerter Kreisel aufgefunden. Bis heute scheint dieses Instrument zusammen mit einem zweiten Exemplar, das inzwischen in einem Internetauktionshaus entdeckt wurde, das einzige Original zu sein, das explizit mit der ersten systematischen Beschreibung eines solchen Geräts übereinstimmt. Letztere wurde im Jahr 1817 durch den Erfinder des Instruments, J.G.F. Bohnenberger (1765‐1831) veröffentlicht, der das Gerät einfach “Maschine” nannte. J.G.F. Bohnenberger war zu dieser Zeit Professor für Mathematik, Physik und Astronomie an der Universität Tübingen und wissenschaftlicher Leiter der Landesvermessung im jungen Königreich Württemberg.

Die Entdeckung im Kepler‐Gymnasium Tübingen verdeutlichte, dass der historische Hintergrund der “Maschine von Bohnenberger” noch weitgehend ungeklärt war. Dies ist bemerkenswert, da das Instrument die Basis für J.B.L. Foucaults bedeutende Arbeit zur Kreiseltechnik war, den unmittelbaren Vorgänger seines Gyroskops darstellte und so zum Wegbereiter wichtiger mechanischer Navigationsinstrumente wie dem künstlichen Horizont, dem Kreiselkompass und der Inertialplattform wurde. Vor diesem Hintergrund haben die Autoren des Beitrags versucht, Bohnenbergers Erfindung wissenschaftsgeschichtlich ein wenig auf‐zuarbeiten. Es gelang unter anderem, die anfängliche Verbreitung des Instruments, das durch den Tübinger Universitätsmechanikus J.W.G. Buzengeiger (1778‐1836) hergestellt wurde, zu erhellen und den Zeitpunkt der Erfindung auf das Jahr 1810 einzugrenzen (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Die Entwicklung der Strömungsmechanik von Archimedes bis Stokes und Reynolds
Authors: Mahrenholtz Oskar , Gaul Lothar
Published: December 2011

Kurze Darstellung der Grundlagen und der Entwicklung der Strömungsmechanik vom Altertum bis zum Ende des 19. Jahrhunderts (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
UM‐SCC‐104: A New human papillomavirus‐16–positive cancer stem cell–containing head and neck squamous cell carcinoma cell line
Authors: Tang Alice L. , Hauff Samantha J. , Owen John H. , Graham Martin P. , Czerwinski Michael J. , Park Jung Je , Walline Heather , Papagerakis Silvana , Stoerker Jay , McHugh Jonathan B. , Chepeha Douglas B. , Bradford Carol R. , Carey Thomas E. , Prince Mark E.
Published: December 2011

Background

Few human papillomavirus (HPV)(+) head and neck squamous cell carcinoma (HNSCC) cell lines exist. We established University of Michigan‐squamous cell carcinoma‐104 (UM‐SCC‐104), a new HPV(+) HNSCC cell line from a recurrent oral cavity tumor, and characterized it for the presence of cancer stem cells (CSCs).

Methods

Tumor cells were tested for biomarker expression by immunohistology, and the presence of HPV was assessed by several methods.

Results

UM‐SCC‐104 has a unique genotype, contains HPV‐16, and expresses E6/E7. Inoculation of aldehyde dehydrogenase (ALDH)(+) and ALDH(−) cells in an immunocompromised mouse resulted in tumor growth from the ALDH(+) cells after 6 weeks that recapitulated the histology of the primary, whereas ALDH(−) cells did not produce tumors.

Conclusion

UM‐SCC‐104, a new HPV‐16, CSC‐containing HNSCC cell line will aid in studying recurrent HPV(+) tumors. The aggressive nature of this tumor is consistent with high uniform expression of epidermal growth factor receptor (EGFR) and a functionally significant proportion of ALDH(+) CSCs. © 2011 Wiley Periodicals, Inc. Head Neck, 2011
Variability of volume strain in bounded heterogeneous media
Authors: Chang Ching‐Min , Yeh Hund‐Der
Published: December 2011

The deformation of the solid matrix affects the fluid pore pressure and flow by altering the pore volume. Such interaction in turn affects the storage of groundwater in the void space. Obviously, this subject is of interest in groundwater hydrology. This paper describes an investigation of the effect of aquifer heterogeneity on the variability of the fluid pressure head and solid's volume strain, where the assumption of a constant vertical total stress leads to a relatively simple relationship between changes in solid's volume strain and fluid pressure head. To solve the problem analytically, focus is placed on the one‐dimensional models. It is found from our closed‐form solutions that the variance and correlation length of the log hydraulic conductivity are important in increasing the variability of pressure head and solid's volume strain. It is hoped that our findings will provide a basic framework for understanding and quantifying field‐scale volume strain processes and be useful in stimulating further research in this area. Copyright © 2011 John Wiley & Sons, Ltd.
Chemoprevention of mouse lung and colon tumors by suberoylanilide hydroxamic acid and atorvastatin
Authors: Pereira Michael A. , Warner Blake M. , Knobloch Thomas J. , Weghorst Christopher M. , Lubet Ronald A. , Steele Vernon E. , Casto Bruce C.
Published: December 2011

Atorvastatin and suberoylanilide hydroxamic acid (SAHA) were evaluated for chemoprevention of mouse lung tumors. In Experiment 1, lung tumors were induced by vinyl carbamate in strain A/J mice followed by 500 mg/kg SAHA, 60 or 180 mg/kg atorvastatin, and combinations containing SAHA and atorvastatin administered in their diet. SAHA and both combinations, but not atorvastatin, decreased the multiplicity of lung tumors, including large adenomas and adenocarcinomas with the combinations demonstrating the greatest efficacy. In Experiment 2, lung tumors were induced by 4‐(methylnitrosoamino)‐1‐(3‐pyridyl)‐1‐butanol in strain A/J mice followed by 180 mg/kg atorvastatin, 500 mg/kg SAHA, or both drugs administered in the diet. SAHA and the combination of both drugs, but not atorvastatin alone, decreased the multiplicity of lung tumors and large tumors, with the combination demonstrating greater efficacy. In Experiment 3, lung tumors were induced by 1,2‐dimethylhydrazine in Swiss‐Webster mice followed by 160 mg/kg atorvastatin, 400 mg/kg SAHA, or a combination of both drugs administered in the diet. SAHA and the combination, but not atorvastatin, decreased the multiplicity of lung tumors with the combination demonstrating greater efficacy. The multiplicity of colon tumors was decreased by SAHA, atorvastatin, and the combination, without any significant difference in their efficacy. mRNA expression analysis of lung tumor bearing mice suggested that the enhanced chemopreventive activity of the combination is related to atorvastatin modulation of DNA repair, SAHA modulation of angiogenesis, and both drugs modulating invasion and metastasis pathways. Atorvastatin demonstrated chemoprevention activity as indicated by the enhancement of the efficacy of SAHA to prevent mouse lung tumors.
PpIX fluorescence combined with auto‐fluorescence is more accurate than PpIX fluorescence alone in fluorescence detection of non‐melanoma skin cancer: An intra‐patient direct comparison study
Authors: van der Beek Nick , de Leeuw Jaap , Demmendal Claire , Bjerring Peter , Neumann H.A. Martino
Published: December 2011

Background

Previous research on fluorescence detection of non‐melanoma had mixed results. An accurate non‐invasive method for the detection of skin cancer is valuable to dermatologists because of the high incidence of skin cancer among the aging population. One notable difference between the methods of fluorescence detection previously studied was the use of the auto‐fluorescence of the skin. Currently, there has not been a direct comparison between both methods of fluorescence detection.

Objective

To compare the accuracy of PpIX fluorescence and auto‐fluorescence normalized PpIX fluorescence detection systems for the localization non‐melanoma skin cancers (NMSC).

Methods

We conducted an observer blinded direct comparison of both methods. Thirty patients, 14 females and16 males, mean age 62 (SD = 9 years), skin type I to III and being suspected of having one or more NMSC, visited an independent treatment centre for dermatology. The patients were investigated using a fluorescence detection system capable of both normalized and non‐normalized PpIX fluorescence measurements. Liposomal encapsulated 5‐aminolevulinic acid was used as a photosensitizer. For each area being investigated, the associated normalized and non‐normalized fluorescence measurements were directly compared. The results of the analysis were confirmed by clinical investigation using a dermatoscope. Both methods were evaluated based on the number of true and false positives and the number of true and false negatives. Specificity and sensitivity were calculated. Statistical significance of the findings was determined using Pearson's Chi‐squared test.

Results

The non‐normalized method was found to have a sensitivity of 27 % and a specificity of 39 % and the normalized method has a sensitivity of 97% and a specificity of 100%. This difference is statistically significant (p < 0.05).

Conclusion

Using auto‐fluorescence in PpIX fluorescence detection of NMSC is more accurate that PpIX fluorescence detection alone. Lasers Surg. Med. 44:271–276, 2012. © 2011 Wiley Periodicals, Inc.
Acute exercise adjustments of cardiovascular autonomic control in diabetic rats
Authors: Da Pureza Demilto Yamagushi , Jorge Luciana , Sanches Iris Callado , Irigoyen Maria‐cláudia , De Souza Romeu Rodrigues , De Angelis Kátia
Published: December 2011

Introduction: We evaluated the role of cardiovascular autonomic changes in hemodynamics at rest and in response to exercise in streptozotocin‐induced diabetic rats. Methods: Male Wistar rats were divided into nondiabetic (ND, n = 8) and diabetic (D, n = 8) groups. Arterial pressure signals were recorded in the basal state and after atropine or propranolol injections at rest, during exercise and during recovery. Results: At rest, vagal tonus was reduced in D (37 ± 3 bpm) in comparison with the ND group (61 ± 9 bpm). Heart rate during exercise was lower in D in relation to ND rats associated with reduced vagal withdrawal in the D group. The D rats had an increase in vagal tonus in the recovery period (49 ± 6 bpm). Conclusions: Exercise‐induced hemodynamic adjustment impairment in diabetic rats was associated with reduced cardiac vagal control. The vagal dysfunction was attenuated after aerobic exercise, reinforcing the positive role of this approach in the management of cardiovascular risk in diabetics. Muscle Nerve 46: 96–101, 2012
Diffusion tensor MRI to assess skeletal muscle disruption following eccentric exercise
Authors: Cermak Naomi M. , Noseworthy Michael D. , Bourgeois Jacqueline M. , Tarnopolsky Mark A. , Gibala Martin J.
Published: December 2011

Introduction: Structural evidence of exercise‐induced muscle disruption has traditionally involved histological analysis of muscle tissue obtained by needle biopsy, however, there are multiple limitations with this technique. Recently, diffusion tensor magnetic resonance imaging (DT‐MRI) has been successfully demonstrated to noninvasively assess skeletal muscle abnormalities induced by traumatic injury. Methods: To determine the potential for DT‐MRI to detect musculoskeletal changes after a bout of eccentric exercise, 10 healthy men performed 300 eccentric actions on an isokinetic dynamometer. DT‐MRI measurements and muscle biopsies from the vastus lateralis were obtained before and 24 h post‐exercise. Results: Z‐band streaming was higher 24 h post‐exercise compared with baseline (P < 0.05). The histological indices of damage coincided with changes in DT‐MRI parameters of fractional anisotropy (FA) and apparent diffusion coefficient; reflecting altered skeletal muscle geometry (P < 0.05). Z‐band streaming quantified per fiber correlated with FA (r = −0.512; P < 0.05). Conclusions: DT‐MRI can detect changes in human skeletal muscle structure following eccentric exercise. Muscle Nerve 46: 42–50, 2012
A family of realizability criteria for the real and symmetric nonnegative inverse eigenvalue problem
Authors: Soto Ricardo L.
Published: December 2011

A new realizability criterion for the real nonnegative inverse eigenvalue problemis introduced. This criterion is a nontrivial extension of a powerful previous sufficient condition, based on negativity compensation. If the criterion is satisfied, then we can always construct a realizing matrix. It is also proved that this new criterion is easily adaptable to be sufficient for the construction of a symmetric nonnegative matrixwith given spectrum. In a natural way, the criterion extends to a family of sufficient conditions for the problem to have a solution. Copyright © 2011 John Wiley & Sons, Ltd.
Gene amplification ofESR1in breast cancers—fact or fiction? A fluorescencein situhybridization and multiplex ligation‐dependent probe amplification study
Authors: Ooi Akishi , Inokuchi Masafumi , Harada Shinichi , Inazawa Johji , Tajiri Ryousuke , Kitamura Seiko Sawada‐ , Ikeda Hiroko , Kawashima Hiroko , Dobashi Yoh
Published: December 2011

Oestrogen receptor‐alpha (ERα), encoded by theESR1gene located on 6q25, is a nuclear transcription factor. Since it was reported in 2007 that more than 20% of breast cancers showESR1gene amplification, there has been considerable controversy about its frequency and clinical significance. We set out to assess the frequency and levels ofESR1amplification in breast cancers. In a total of 106 breast needle biopsy specimens examined by immunohistochemistry, 78 tumours contained more than 10% ERα‐positive cancer cells. In fluorescencein situhybridization (FISH) analysis with anESR1‐specific probe, variously extendedESR1signals were found in ERα‐expressing cells. Some of these were indistinguishable from large clustered signals generally accepted to mean high‐level gene amplification in homogeneously staining regions (HSRs), and could be considered to represent gene amplification. However, with RNase treatment, the ‘HSR‐like’ signals changed to small compact signals, and are thus thought to represent concentrated RNA. FISH using two differently labelled probes corresponding to the non‐overlapping 5′‐ and 3′‐end portions of theESR1gene on touch smears showed a preserved spatial relationship of the 3′ to 5′ sequence ofESR1, therefore strongly suggesting that the RNA consisted of primary transcripts. Using touch smears obtained from 51 fresh tumours, precise enumeration ofESR1signals with a correction by the number of centromere 6 on FISH after RNase A treatment revealed that three tumours (5.9%) had tumour cells with one to three additional copies ofESR1as predominant subpopulations. This infrequent and low level of gene amplification ofESR1was also detected as a ‘gain’ of the gene by analysis with multiplex ligation‐dependent probe amplification (MLPA). The consistent results from immunohistochemistry, FISH, and MLPA in the present study settle the long‐standing debate concerning gene amplification ofESR1in breast carcinoma. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
On the formation mechanism for electrically generated exciplexes in a carbazole–pyridine copolymer
Authors: Hayer Anna , Van Regemorter Tanguy , Höfer Bianca , Mak Chris S. K. , Beljonne David , Köhler Anna
Published: December 2011

Although carbazole‐containing copolymers are frequently used as hole‐transporting host materials for polymer organic light‐emitting diodes (OLEDs), they often suffer from the formation of undesired exciplexes when the OLED is operated. The reason why exciplexes sometimes form for electrical excitation, yet not for optical excitation is not well understood. Here, we use luminescence measurements and quantum chemical calculations to investigate the mechanism of such exciplex formation for electrical excitation (electroplex formation) in a carbazole–pyridine copolymer. Our results suggest that the exciplex is formed via a positively charged interchain precursor complex. This complex is stabilized by interactions that involve the nitrogen lone pairs on both chain segments. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Soft bacterial polyester‐based shape memory nanocomposites featuring reconfigurable nanostructure
Authors: Ishida Kazuki , Hortensius Rebecca , Luo Xiaofan , Mather Patrick T.
Published: December 2011

In this work, a novel soft shape memory polymer nanocomposite derived from a bacterial medium‐chain‐length polyhydroxyalkanoate, poly(3‐hydroxyoctanoate‐co‐3‐hydroxyundecenoate) (PHOU), used to form a covalent network grafted with polyhedral oligomeric silsesquioxane (POSS), a crystallizable inorganic–organic hybrid nanofiller, was prepared. The PHOU–POSS nanocomposite, PHOU–POSSw‐net [w (= POSS content, wt %) = 0, 20, 25, 30, and 38], is a completely amorphous elastomer (w ≤ 20) or contains POSS nanocrystals embedded in the amorphous PHOU matrix (w ≥ 25). The hybrid nanostructure of PHOU–POSSw‐net (w ≥ 25) is featured by its reconfigurability, based on aggregation and disaggregation of POSS covalently connected to the PHOU network, which enables excellent shape fixing and recovery. Furthermore, it exhibits soft and elastomeric mechanical properties even in the fixed state. Taking advantage of the shape memory ability as well as the softness in the fixed state, we demonstrate microscale dynamic surface topography of PHOU–POSSw‐net. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012
Factors associated with psychological distress following colposcopy among women with low‐grade abnormal cervical cytology: a prospective study within the Trial Of Management of Borderline and Other Low‐grade Abnormal smears (TOMBOLA)
Authors: Sharp Linda , Cotton Seonaidh , Carsin Anne‐Elie , Gray Nicola , Thornton Alison , Cruickshank Margaret , Little Julian ,   on behalf of the TOMBOLA Group
Published: December 2011

Background

Little is known about psychological after‐effects of colposcopy and associated investigations and treatment in women with low‐grade abnormal cervical cytology. We investigated psychological distress following colposcopy and related procedures.

Methods

Nine hundred and eighty‐nine women aged 20–59 years with routine cytology showing low‐grade abnormalities were recruited to the Trial of Management of Borderline and other Low‐grade Abnormal smears and attended colposcopy. If the cervical transformation zone (TZ) was colposcopically abnormal, women had immediate loop excision or diagnostic punch biopsies, with treatment if these showed cervical intraepithelial neoplasia grade 2/3 (CIN2/3). Women completed socio‐demographic and psychosocial questionnaires at recruitment and before colposcopy. Six weeks after their last procedure, women completed the Impact of Event Scale (IES). Logistic regression was used to determine factors associated with significant psychological distress (IES ≥ 9). Analyses were stratified by colposcopic impression.

Results

The response rate was 74%. Six weeks after the last procedure, 86 (21%) of 391 women with a normal TZ had significant distress compared with 144 (42%) of 337 with an abnormal TZ. In both groups, significant distress was associated with anxiety pre‐colposcopy and pain or discharge afterwards. Additional variables predicting distress in women with a normal TZ were worries about having sex and dissatisfaction with support from others. In women with an abnormal TZ, additional predictors of distress were younger age, CIN2/3, bleeding following colposcopy and worries about having cancer.

Conclusions

Substantial proportions of women experience psychological distress after colposcopy and related procedures, even when the colposcopy is normal. This is an important cost of cervical screening. Interventions to alleviate these adverse psychological effects are required. Copyright © 2011 John Wiley & Sons, Ltd.
Respiratory and cardiovascular indicators of autonomic nervous system dysregulation in familial dysautonomia
Authors: Carroll Michael S. , Kenny Anna S. , Patwari Pallavi P. , Ramirez Jan‐Marino , Weese‐Mayer Debra E.
Published: December 2011

Familial dysautonomia (FD) is a profound sensory and autonomic nervous system disorder associated with an increased risk for sudden death. While bradycardia resulting from loss of sympathetic tone has been hypothesized to play a role in this mortality, extended in‐home monitoring has failed to find evidence of low heart rates in children with FD. In order to better characterize the specific cardio‐respiratory pathophysiology and autonomic dysregulation in patients with FD, 25 affected children and matched controls were studied with in‐home technology, during day and night. Respiratory and heart rate timing and variability metrics were derived from inductance plethysmography and electrocardiogram signals. Selective shortening of inspiratory time produced an overall increase in respiratory frequency in children with FD, with higher daytime respiratory variability (vs. controls), suggesting alterations in central rhythm generating circuits that may contribute to the heightened risk for sudden death. Overall heart rate was increased and variability reduced in FD cases, with elevated heart rates during 20% of study time. Time and frequency domain measures of autonomic tone indicated lower parasympathetic drive in FD patients (vs. controls). These results suggest withdrawal of vagal, rather than sympathetic tone, as a cause for the sustained increase and dramatic lability in respiration and heart rates that characterize this disorder. Pediatr Pulmonol. 2012; 47:682–691. © 2011 Wiley Periodicals, Inc.
Childhood wheeze while taking propranolol for treatment of infantile hemangiomas
Authors: Shepherd Darren , Adams Susan , Wargon Orli , Jaffe Adam
Published: December 2011

While it is recognized that beta‐blockers can exacerbate asthma symptoms in older children and adults, there are few descriptions of a similar effect in infants. We describe three infants who developed wheeze during treatment with a beta‐blocker for infantile hemangiomas and conclude that physicians should inquire about respiratory symptoms in this group of children. Pediatr Pulmonol. 2012; 47:713–715. © 2011 Wiley Periodicals, Inc.
Feasibility and Variability of Measuring the Lung Clearance Index in a Multi‐Center Setting
Authors: Fuchs Susanne I. , Ellemunter Helmut , Eder Johannes , Mellies Uwe , Grosse‐Onnebrink Jörg , Tümmler Burkhard , Staab Doris , Jobst Andrea , Griese Matthias , Ripper Jan , Rietschel Ernst , Zeidler Susanne , Ahrens Frank , Gappa Monika
Published: December 2011

The Lung Clearance Index (LCI) is superior to spirometry in detecting early lung disease in cystic fibrosis (CF) and correlates with structural lung changes seen on CT scans. The LCI has the potential to become a novel outcome parameter for clinical and research purposes. However longitudinal studies are required to further prove its prognostic value. Multi‐center design is likely to facilitate realization of such studies.

Therefore the aim of the present study was to assess multi‐center feasibility and inter‐center variability of LCI measurements in healthy children and adolescents. Comparative measurements were performed in unselected patients with CF to confirm previous single‐center results.

LCI measurements were performed in eight centers using the EasyOne Pro, MBW Module (ndd Medical Technologies, Zurich, Switzerland).

The overall success rate for LCI measurements was 75.5%, leaving 102/151 measurements in healthy volunteers and 139/183 measurements in patients with CF for final analysis. Age ranged between 4 and 24 years. Mean LCI (range of means among centers) was 6.3 (6.0–6.5) in healthy volunteers and thus normal. Inter‐center variability of center means was 2.9%, ANOVA including Schffé procedure demonstrated no significant inter‐center differences (P > 0.05). Mean LCI (range of means among centers) was 8.2 (7.4–8.9) in CF and thus abnormal.

Our study demonstrates good multi‐center feasibility and low inter‐center variability of the LCI in healthy volunteers when measured with the EasyOne Pro MBW module. Our data confirm published LCI data in CF. However, central coordination, quality control, regular training, and supervision during the entire study appear essential for successfully performing multi‐center trials. Pediatr Pulmonol. 2012; 47:649–657. © 2011 Wiley Periodicals, Inc.
Pulmonary function and long‐term follow‐up of children with tracheobronchomalacia
Authors: Moore Peter , Smith Holly , Greer Ristan M , McElrea Margaret , Masters Ian Brent
Published: December 2011

Background

Primary tracheobronchomalacia (TBM) is a disease of the large airways. Long‐term follow‐up studies of TBM patients have not been reported. This study was undertaken to further elicit the natural history of this condition and the presence of concomitant reactive airways disease through clinical profiling and pulmonary function testing.

Methods

Twenty‐one children diagnosed with TBM by bronchoscopy between 1998 and 2001 in Queensland were recruited in 2008. Parents completed a questionnaire detailing their child's respiratory symptoms over the previous 12 months. Children then undertook pulmonary function and flow–volume loop classification. Mannitol bronchial provocation testing or post‐bronchodilator spirometry was performed to assess for the confounding presence of reactive airways disease.

Results

Data from 19 children (12 males) were able to be analyzed. The median age was 9.4 (range 7.6–14.3) years. 15 parents indicated their child's symptoms were unresolved. The mean FEV1 was 81% predicted with 7 <80% predicted. This was significantly lower than the percent predicted population mean (P = 0.0005). Mean FEV1/FVC, FEF25–75, and PEF were also significantly reduced (P = < 0.0001). Four participants had a classical TBM flow–volume loop on analysis. One of 15 (6.7%) participants recorded a positive test for reactive airways disease.

Conclusions

Clinical symptom profiles and pulmonary function indicate persistent functional mechanical abnormalities of the large and small airways in TBM patients, and the absence of reactive airways disease. Pediatr Pulmonol. 2012; 47:700–705. © 2011 Wiley Periodicals, Inc.
Altered nuclear cofactor switching in retinoic‐resistant variants of the PML‐RARα oncoprotein of acute promyelocytic leukemia
Authors: Farris Mindy , Lague Astrid , Manuelyan Zara , Statnekov Jacob , Francklyn Christopher
Published: December 2011

Acute promyelocytic leukemia (APL) results from a reciprocal translocation that fuses the gene for the PML tumor suppressor to that encoding the retinoic acid receptor alpha (RARα). The resulting PML‐RARα oncogene product interferes with multiple regulatory pathways associated with myeloid differentiation, including normal PML and RARα functions. The standard treatment for APL includes anthracycline‐based chemotherapeutic agents plus the RARα agonist all‐trans retinoic acid (ATRA). Relapse, which is often accompanied by ATRA resistance, occurs in an appreciable frequency of treated patients. One potential mechanism suggested by model experiments featuring the selection of ATRA‐resistant APL cell lines involves ATRA‐resistant versions of the PML‐RARα oncogene, where the relevant mutations localize to the RARα ligand‐binding domain (LBD). Such mutations may act by compromising agonist binding, but other mechanisms are possible. Here, we studied the molecular consequence of ATRA resistance by use of circular dichroism, protease resistance, and fluorescence anisotropy assays employing peptides derived from the NCOR nuclear corepressor and the ACTR nuclear coactivator. The consequences of the mutations on global structure and cofactor interaction functions were assessed quantitatively, providing insights into the basis of agonist resistance. Attenuated cofactor switching and increased protease resistance represent features of the LBDs of ATRA‐resistant PML‐RARα, and these properties may be recapitulated in the full‐length oncoproteins. Proteins 2012; © 2011 Wiley Periodicals, Inc.
RNA interference is induced in the glassy winged sharpshooter Homalodisca vitripennis by actin dsRNA
Authors: Rosa Cristina , Kamita Shizuo G , Falk Bryce W
Published: December 2011

BACKGROUND: The glassy winged sharpshooter, Homalodisca vitripennis, is an unusually robust and efficient leafhopper vector of Xylella fastidiosa. X. fastidiosa is the causative agent of Pierce's disease, almond scorch, citrus variegated chlorosis and other serious plant diseases. The present study was conducted to establish whether RNA interference (RNAi) was induced in nymphal H. vitripennis that were injected with actin dsRNAs and other dsRNAs.

RESULTS: A dramatic reduction in target H. vitripennis actin mRNAs and the formation of small interfering RNAs (siRNAs), hallmarks of RNAi, were found following the injection of actin dsRNAs. Quantitative reverse transcription PCR indicated an 80% reduction in actin mRNA levels by 5 days post‐injection. Western blot analysis showed a dramatic drop in actin protein levels by 3 days post‐injection. Biological effects such as incomplete nymphal–adult ecdysis and > 95% mortality were also found following the injection of fifth‐instar nymphs with actin dsRNA. Dramatic reductions in target mRNA levels were also found following the injection of other dsRNAs into fifth‐instar H. vitripennis.

CONCLUSION: The findings indicate that RNAi is induced in post‐embryonic leafhoppers by dsRNA. The present system can be used to screen potential gene‐silencing targets that can be used for reducing the vector competence of H. vitripennis and other leafhoppers. Copyright © 2011 Society of Chemical Industry
Dysprosium doped lead fluoroborate glasses: Structural, optical, and thermal investigations
Authors: Rayappan I. Arul , Maheshvaran K. , Babu S. Surendra , Marimuthu K.
Published: December 2011

Dy3+ doped lead fluoroborate (LFB) glasses (B2O3 + PbO + PbF2) have been prepared following conventional melt quenching technique by varying the concentration of Dy2O3 in the order 0.01, 0.1, 1, 2, and 3 mol%. X‐ray powder diffraction (XRD), Fourier transform infrared (FTIR), optical absorption, fluorescence emission, and decay curves have been recorded and analyzed. From the optical measurements and based on the Judd–Ofelt (JO) theory, the JO intensity parameters were evaluated and in turn used to evaluate the radiative transition probabilities (A), stimulated emission cross‐section ($\sigma _{{\rm P}}^{{\rm E}} $), radiative lifetimes (τrad), and branching ratios (βR) for the various 4F9/2 → 6HJ (J = 11/2, 13/2, 15/2) transitions of Dy3+ ions in the LFB glasses and these values were compared with the other reported Dy3+:glasses. The decay curves of the 4F9/2 level were measured and found to be deviate from the exponential nature with the increase in Dy3+ ion concentration. The luminescence quantum efficiency of the 4F9/2 level was also determined and discussed. Differential scanning calorimetry (DSC) curves were used to evaluate the glass stability factor (S) and Hruby's parameter (HR) through the glass transition (Tg), crystallization (Tc), and melting (Tm) temperatures and these results were discussed and reported.
Damping behavior of a novel porous CuAlMn shape memory alloy fabricated by sintering‐dissolution method
Authors: Wang Qingzhou , Lu Dongmei , Cui Chunxiang , Yan Najun , Wang Qian
Published: December 2011

A novel porous Cu–11.7Al–2.49Mn (wt%) shape memory alloy (SMA) was fabricated by sintering‐dissolution method. Damping behavior of the resulting specimen was investigated by internal friction (IF) technique through the method of forced vibration. An IF peak arises at around 200 °C during heating. This peak has been ascribed to the reverse martensitic transformation (MT). Heat treatments of solution and quenching have important influences on the IF background and the IF peak due to the changes of microstructures and phase constitution of the matrix. Compared with bulk specimen, the porous specimen has a significantly enhanced IF background and a decreased IF peak. It is suggested that the enhancement of IF background originates from the effect of pores and the production as well as movement of dislocations, while the decrease of IF peak from the existence of multifarious defects around pores.
One‐pot synthesis of homogeneous CdSexS1−x alloyed quantum dots with tunable composition in a green N‐oleoylmorpholine solvent
Authors: Wang Binbin , Jiang Yang , Liu Chao , Lan Xinzheng , Liu Xinmei , Wang Wenjun , Duan Hongyan , Zhang Yugang , Li Shanying , Zhang Zhongping
Published: December 2011

Composition‐tunable ternary CdSexS1−x quantum dots (shortened form, CdSeS QDs) with different emission colors were prepared via a non‐injection, one‐pot approach in a green N‐oleoylmorpholine solvent for the first time, with air‐stable compounds cadmium oxide (CdO), selenium (Se) powder, and sulfur (S) powder as Cd, Se, and S sources, respectively. The synthesis of ternary alloyed CdSeS QDs with homogeneous composition were performed by mixing cadmium oleate solution obtained from the reaction between CdO and oleic acid, and the premixed solution containing Se and S in N‐oleoylmorpholine solvent. The resulting CdSexS1−x QDs were characterized through UV–visible absorption spectrophotometer and fluorescence spectrophotometer, and they exhibited well‐resolved absorption feature and dominant band‐edge emission with a moderate size distribution (the full width at half maximum (FWHM) was 30–50 nm). The maximum photoluminescent (PL) quantum yield (QY) was as high as 60%. The high‐resolution transmission electron microscopy (HRTEM) images and powder X‐ray diffraction (XRD) patterns suggested that the as‐prepared ternary QDs possessed high crystalline and a cubic zinc‐blende structure. In addition, the results indicated that the similar reactivity between S/N‐oleoylmorpholine and Se/N‐oleoylmorpholine is responsible for the homogeneous structure of the as‐obtained CdSeS alloyed QDs.

magnified image

The as‐prepared CdSexS1−x QDs exhibit sharp emission features and various colors.
Adenoviral load diagnostics by quantitative polymerase chain reaction: techniques and application
Authors: Ganzenmueller Tina , Heim Albert
Published: December 2011

Human adenoviruses (HAdV) can cause fatal complications such as disseminated disease especially in a post‐transplant setting. With conventional methods, disseminated HAdV disease could only be diagnosed with delay. Quantification of the HAdV load by real‐time PCR in peripheral blood promised to solve this diagnostic dilemma. Here we review the development, applications and significance of quantitative HAdV PCR.

The high genetic divergence of the 56 HAdV types was a major obstacle for developing a quantitative HAdV PCR covering all types. Several protocols focused either on a few, probably predominating types or tried to detect all known HAdV types by using a bundle of assays or a few multiplexed PCRs. Alternatively, generic quantitative real‐time HAdV PCR protocols using primer and probe consensus sequences have been designed, providing considerable reduction of costs and hands‐on time.

Application of HAdV load testing by several studies on stem cell transplant (SCT) recipients indicated that rapidly increasing HAdV blood loads as well as high HAdV DNAemia (e.g. >104 copies/ml) are predictive for disseminated HAdV disease although a universal threshold value has not yet been established. HAdV load testing has been implemented for systematic screening of SCT patients permitting early diagnosis, pre‐emptive treatment initiation and monitoring of antiviral therapy. However, further investigations are required to validate proposed virus load thresholds.

Moreover, other applications of quantitative HAdV PCR, such as the diagnosis of localized HAdV disease, the analysis of environmental samples and monitoring of gene therapy with adenoviral vectors will be addressed in this review. Copyright © 2011 John Wiley & Sons, Ltd.