bluuebunny/crossref_metadata_2025 huggingface dataset:
Evolution of sonographic findings in a fetus with ileal atresia
Authors: Lee Jung‐Hyun , Im Soo‐Ah , Lee Guisera
Published: May 2011

We report a case of a meconium pseudocyst secondary to ileal atresia and midgut volvulus. Initially, a single anechoic cyst was detected on prenatal sonography. The cyst gradually increased in size during the second trimester and eventually appeared as a large mass in the lower abdomen with echogenic content and associated with bowel dilatation. This case indicates that until the mid third trimester a single sonolucent cyst without signs of bowel obstruction may be associated with congenital intestinal obstruction. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011
Characterization of nontraumatic focal splenic lesions using contrast‐enhanced sonography
Authors: Chiavaroli Roberto , Grima Pierfrancesco , Tundo Paolo
Published: May 2011

Purpose.

To compare contrast‐enhanced sonography (CEUS) with contrast‐enhanced CT in the assessment of nontraumatic focal lesions of the spleen.

Methods.

CEUS and CT findings in 22 patients with fever of unknown origin and ultrasound‐detected splenic focal lesions were analyzed retrospectively. CEUS was performed using an ultrasound unit equipped with a 3.6‐MHz probe and contrast‐specific software. A 4‐ml bolus of second‐generation contrast medium was used. The CEUS examinations included a 4‐minute recording following injection of the contrast medium. MRI, splenic biopsy, or ultrasound follow‐up were used if findings from CT were inconclusive.

Results.

The final diagnoses were as follows: seven splenic infarcts, five hemangiomas, three lacerations, two benign cysts, one lymphoma, one granuloma, one abscess, and two lesions of unknown etiology. CEUS and CT had the same specificity (77.2%). Both CEUS and CT failed to characterize nodular hypovascular lesions with a hypoenhancing pattern.

Conclusions.

CEUS is as effective as CT for characterizing nontraumatic focal lesions of the spleen. If CEUS findings are consistent with a benign splenic lesion, CT seems to be of limited additional value. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011;
Sonographic measurement of cervical volume in nonpregnant women using the geometric formula for a cylinder versus the three‐dimensional automated virtual organ computer‐aided analysis (vocal)
Authors: Papoutsis Dimitrios , Daskalakis George , Antonakou Angeliki , Rodolakis Alexandros , Mesogitis Spiridon , Antsaklis Aris
Published: May 2011

Background.

To sonographically evaluate the volume of uterine cervix in nonpregnant women with use of the geometric formula for a cylinder and to assess agreement with the reference Virtual Organ Computer‐Aided AnaLysis (VOCAL) method.

Methods.

Three‐dimensional ultrasound volume datasets of the uterine cervix from 81 women were obtained prospectively within a 1‐year period. Volume measurements were performed using VOCAL and the geometric formula for a cylinder. Reliability was evaluated using intraclass correlation coefficient and Bland‐Altman plots were produced to examine intermethod agreement. Time needed to perform measurements was compared with Student's t test.

Results.

There was good agreement between VOCAL and the geometric formula for a cylinder (mean percentage difference, −0.78%; 95% limits of agreement, −17.59–16.03%). Measurements made by the formula for a cylinder were slightly greater than VOCAL by a mean (±SE) of 0.78% (±0.95%). A high degree of reliability was observed between the two methods (intraclass correlation coefficient, 0.97; 95%CI, 0.95–0.98). Cervical volume estimation with the geometric formula for a cylinder was faster to obtain.

Conclusions.

This method comparison study shows that the geometric formula for a cylinder has good agreement with VOCAL and can determine the volume of the cervix in a faster way. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011
Assessment of right atrial pressure using echocardiography and correlation with catheterization
Authors: Yildirimturk Ozlem , Tayyareci Yelda , Erdim Refik , Ozen Ersin , Yurdakul Selen , Aytekin Vedat , Demiroglu IC Cemsid , Aytekin Saide
Published: May 2011

Purpose:

Right ventricular systolic pressure is crucial for both treatment and prognosis of cardiovascular and pulmonary diseases. The proper measurement of right ventricular systolic pressure depends on an accurate estimation of right atrial pressure (RAP). There is no standard method for estimating RAP noninvasively. The purpose of this study was to compare different noninvasive methods, namely, inferior vena cava (IVC) size and inspiratory collapse, tissue Doppler derived E/E′ (TV E/E′) for estimating RAP, and their correlation with catheter‐based measurements in patients with mitral valve stenosis with atrial fibrillation (AF) or normal sinus rhythm (NSR).

Methods:

The study group consisted of 39 patients (13 men, mean age 58.9 ± 11.8 years) with rheumatic mitral valve stenosis. We performed cardiac catheterization and transthoracic echocardiography on all patients.

Results:

Mean RAP measured by catheterization was 9.7 ± 3.8 mmHg. No correlation was found between RAP and TV E/E′ ratio, but there was a significant correlation between RAP and IVC diameter (r = 0.51, p < 0.05). Seventeen patients (43.6%) were in AF and 22 patients (56.4%) were in NSR. There was no correlation between TV E/E′ ratio and RAP in patients with AF and in patients with NSR. RAP was correlated with collapsibility index in patients with AF (r = 0.56, p < 0.05). RAP was significantly correlated with IVC diameter (r = 0.62, p < 0.005) and collapsibility index (r = 0.49, p < 0.05) in patients with NSR.

Conclusions:

The combination of IVC diameter and collapsibility index is a simple a semiquantitative approach that might provide a better estimation of RAP. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011;
Transfection of Noggin in bone marrow stromal cells (BMSCs) enhances BMSC‐induced functional outcome after stroke in rats
Authors: Chen Chen , Cheng Yan , Chen Jieli
Published: May 2011

Early intervention with intravenous administration of bone marrow stromal cells (BMSCs) reduces infarction size and ameliorates functional deficits in rat ischemia models. Noggin, an inhibitor of bone morphogenetic protein (BMP), has been demonstrated to provide protection from ischemic disease. In the present work, we hypothesize that administering Noggin‐transfected BMSCs enhances BMSC‐induced brain repair after cerebral ischemia. We compared the effects of BMSCs alone and Noggin‐transfected BMSCs (Noggin‐BMSCs) systematically delivered into the middle cerebral artery occlusion (MCAo) rat model. Noggin expression in BMSCs was achieved using adenoviral infection together with a green fluorescent protein (GFP) vector to monitor transduction efficiency and facilitate posttransplantation tracking. BMSCs and Noggin‐BMSCs were intravenously injected into the rats 6 hr after MCAo. At 7 days after MCAo, the GFP‐expressing BMSCs and Noggin‐BMSCs were found primarily in the ischemic penumbra, which indicated that the intravenously delivered cells survived and reached in the lesion site. Both BMSC and Noggin‐BMSC treatment significantly promoted neurogenesis in the ipsilateral subventrical zone (SVZ), reduced infarct volume, and led to functional improvement compared with the control group. Moreover, these beneficial effects were significantly greater in the Noggin‐BMSC‐treated group compared with BMSCs alone treatment (P < 0.05). Noggin expression in the ischemic hemisphere was significantly increased in the Noggin‐BMSC‐treated group as revealed by enzyme‐linked immunosorbent assay (ELISA) at 7 days after MCAo compared with BMSC‐treated and control groups (P < 0.05). These results indicate that transfection of Noggin in BMSCs enhances BMSC‐induced neuroprotective effects when administered intravenously during the acute phase after stroke. © 2011 Wiley‐Liss, Inc.
Effects of plant residues and calcite amendments on soil sodicity
Authors: Ranjbar Faranak , Jalali Mohsen
Published: May 2011

The effects of wheat, potato, sunflower, and rape residues and calcite were evaluated in soil that received sodic water. These materials were added to a sandy‐loam soil at a rate of 5%, after which the treated soils were incubated for 1 month at field‐capacity moisture and a temperature of 25°C–30°C. Column leaching experiments using treated soils were then conducted under saturated conditions using water with three sodium‐adsorption ratios (SAR) (0, 10, 40) with a constant ionic strength (50 mmol L–1). The results indicated that the application of plant residues to soils caused an increase in cation‐exchange capacity and exchangeable cations. Leaching experiments indicated that the addition of plant amendments led to increased Na+ leaching and decrease in exchangeable‐sodium percentage (ESP). The ESP of the control soil, after leaching with solutions with an SAR of 10 and 40, increased significantly, but the level of sodification in soils treated with plant residue was lower. Such decreases of soil ESP were greatly affected by the type of plant residues, with the order of: potato‐treated soil > sunflower‐treated soil > rape‐treated soil > wheat‐treated soil > calcite‐treated soil > control soil.
Vertical root distribution in single‐crop and intercropping agricultural systems in Central Kenya
Authors: Neykova Nina , Obando Joy , Schneider Raimund , Shisanya Chris , Thiele‐Bruhn Sören , Thomas Frank M.
Published: May 2011

Intercropping is an important and widespread land‐management system in the tropics. At two agricultural sites in Central Kenya differing in elevation and soil type Haplic Nitisols (eutric) and Vitric Gleysols (eutric, epiclayic, endoclayic), we investigated the vertical root distributions using the trench wall profile method in single‐crop systems of maize (Zea mays L.) and in intercropping systems of maize and legumes (common bean, Phaseolus vulgaris L.; pigeon pea, Cajanus cajan [L.] Millsp.) to test for possible differences in the use of water and nutrient resources. The physico‐chemical soil properties of the sites were similar and imposed no restrictions to the vertical growth of the roots into soil depths of 1.4 m. The vertical distributions of the fine roots (∅︁ 0.5–2 mm) and very fine roots (∅︁ < 0.5 mm) were quantified by calculating the parameter β which was computed from the cumulative fraction (Y) of the root densities along the depth (d) of the soil profiles (Y = 1 – βd). We found no consistent differences between the single‐crop and the intercropping systems in the rooting depth down to 1.4 m. However, higher β values for fine roots of the intercropping systems were indicative of a more homogeneous vertical root distribution than in the single‐crop fields. In the intercropping fields, 50% of the total number of fine roots were distributed over the uppermost 36 cm of the soil, whereas in the single‐crop fields, 50% of the fine roots were concentrated in the uppermost 15–21 cm. Medium‐sized roots (∅︁ > 2–5 mm) were detected in the intercropping fields only. The more homogeneous root distribution in the intercropping fields likely indicates a more efficient use of the limited resources nutrients and water.
Accumulation, distribution, and physiological contribution of oxalic acid and other solutes in an alkali‐resistant forage plant, Kochia sieversiana, during adaptation to saline and alkaline conditions
Authors: Ma Ying , Guo Liquan , Wang Haixiu , Bai Bing , Shi Decheng
Published: May 2011

Kochia sieversiana (Pall.) C. A. Mey is a forage plant in the family Chenopodiaceae, which can grow in extremely alkalinized grasslands at pH levels of 10 or higher. Kochia sieversiana often contains a large amount of oxalic acid. In the present study, seedlings of K. sieversiana were exposed to the following conditions: nonstress, salt stress (molar ratio of NaCl : Na2SO4 = 1:1, salinity: 200 mM), and alkali stress (molar ratio of NaHCO3 : Na2CO3 = 1:1, salinity: 200 mM). By determining and analyzing various physiological factors such as the concentrations and distribution of different organic acids (including oxalic acid) in various parts of K. sieversiana, the concentrations of inorganic ions (K+, Na+, Cl–, SO$ _4^{2-} $, etc.), the organic solutes (proline, betaine, and soluble sugar) in shoots, and the accumulation and distribution of oxalic acid in K. sieversiana, the physiological contribution of oxalic acid to K. sieversiana adaptability to saline and alkaline conditions was investigated. Results show that oxalic acid mainly accumulated in shoots, and that its concentration was highest in mature functional leaves where photosynthesis productivity was based and lowest in old stems and roots, regardless of plant treatment (nonstress, salt, or alkali conditions). Under nonstress, salt, and alkali conditions, the concentrations of oxalic acid in mature leaves were 8%, 10%, and 12% of their dry weights, respectively, and were 1%, 0.7%, and 0.6% of dry weights, respectively, in roots. There were varying effects of salt and alkali conditions on oxalic acid concentrations in different parts of K. sieversiana. Oxalic acid concentration increased in leaves, did not change significantly in young stems, and decreased in old stems and roots. The present analysis shows that oxalic acid exists as an organic anion in K. sieversiana. Consequently, oxalic acid not only plays a crucial role in osmoregulation and pH adjustment, but it also is the dominant contributor of negative charge, playing a key role in maintaining ionic balance in vivo. Oxalic acid in K. sieversiana shoots is a key substance on which the adaptation to saline and alkaline conditions is based.
Iodine biofortification in tomato
Authors: Landini Martina , Gonzali Silvia , Perata Pierdomenico
Published: May 2011

Iodine is an essential element in the human diet, and iodine deficiency is a significant health problem. No attempts to increase iodine content in plant‐derived food (biofortification) have so far been particularly effective. We studied iodine uptake in tomato (Solanum lycopersicum L.) to evaluate whether it is possible to increase the iodine concentration in its fruits. Iodine translocation and storage inside tomato tissues were studied using radioactive iodine. Potassium iodide was also supplied at different concentrations to tomato plants to evaluate the resulting iodide concentration both in the vegetative tissues and the fruits. The results indicate that iodine was taken up better when supplied to the roots using hydroponically grown plants. However, a considerable amount of iodine was also stored after leaf treatment, suggesting that iodine transport through phloem also occurred. We found that tomato plants can tolerate high levels of iodine, stored both in the vegetative tissues and fruits at concentrations that are more than sufficient for the human diet. We conclude that tomato is an excellent crop for iodine‐biofortification programs.
Patterns of activity and fatality of migratory bats at a wind energy facility in Alberta, Canada
Authors: Baerwald Erin F. , Barclay Robert M. R.
Published: May 2011

Studying migratory behavior of bats is challenging. Thus, most information regarding their migratory behavior is anecdotal. Recently, however, fatalities of migratory bats at some wind energy facilities across North America have provided the opportunity and impetus to study bat migration at fine spatial and temporal scales. Using acoustic monitoring and carcass searches, we examined temporal and spatial variation in activity levels and fatality rates of bats at a wind energy facility in southern Alberta, Canada. Our goals were to better understand the influence of weather variables and turbine location on the activity and fatality of hoary bats (Lasiurus cinereus) and silver‐haired bats (Lasionycteris noctivagans), and to use that understanding to predict variation in fatality rates at wind energy facilities and recommend measures to reduce fatalities. Overall activity of migratory bats and of silver‐haired bats increased in low wind speeds and warm ambient temperatures, and was reduced when the wind was from the North or Northeast, whereas hoary bat activity increased with falling barometric pressure. Fatalities of migratory bats in general increased with increased activity of migratory bats, increased moon illumination, and falling barometric pressure and were influenced by the interaction between barometric pressure change and activity. Fatalities of silver‐haired bats increased with increased activity, moon illumination, and winds from the south‐east. Hoary bat fatalities increased with falling barometric pressure. Our results indicate that both the activity and fatality of migratory bats are affected by weather variables, but that species differ in their responses to environmental conditions. Spatially, fatalities were not influenced by the position of turbines within a turbine row, but were influenced by the location of turbines within the facility. Our findings have implications for our understanding of bat migration and efforts to reduce fatalities at wind energy facilities. To maximize the reduction of bat fatalities, operators of wind energy facilities could incorporate migratory bats' response to environmental variables, such as barometric pressure and fraction of moon illuminated, into their existing mitigation strategies. © 2011 The Wildlife Society.
Spatial patch occupancy patterns of the Lower Keys marsh rabbit
Authors: Eaton Mitchell J. , Hughes Phillip T. , Nichols James D. , Morkill Anne , Anderson Chad
Published: May 2011

Reliable estimates of presence or absence of a species can provide substantial information on management questions related to distribution and habitat use but should incorporate the probability of detection to reduce bias. We surveyed for the endangered Lower Keys marsh rabbit (Sylvilagus palustris hefneri) in habitat patches on 5 Florida Key islands, USA, to estimate occupancy and detection probabilities. We derived detection probabilities using spatial replication of plots and evaluated hypotheses that patch location (coastal or interior) and patch size influence occupancy and detection. Results demonstrate that detection probability, given rabbits were present, was <0.5 and suggest that naïve estimates (i.e., estimates without consideration of imperfect detection) of patch occupancy are negatively biased. We found that patch size and location influenced probability of occupancy but not detection. Our findings will be used by Refuge managers to evaluate population trends of Lower Keys marsh rabbits from historical data and to guide management decisions for species recovery. The sampling and analytical methods we used may be useful for researchers and managers of other endangered lagomorphs and cryptic or fossorial animals occupying diverse habitats. © 2011 The Wildlife Society.
Outcome of cochlear implantation in asymptomatic congenital cytomegalovirus deafened children
Authors: Malik Vikas , Bruce Iain A. , Broomfield Stephen J. , Henderson Lisa , Green Kevin M.J. , Ramsden Richard T.
Published: May 2011

Objectives/Hypothesis:

Congenital cytomegalovirus (cCMV) infection is a common cause of sensorineural hearing loss (SNHL). The incidence of SNHL is higher in symptomatic cCMV infants and is usually identified early. By contrast, the incidence of SNHL is lower in children with asymptomatic cCMV, and the hearing loss can be delayed in onset and progressive. The objective was to compare the outcome of cochlear implantation in children deafened by cCMV with a control group of children with implants who do not have the condition.

Study Design:

Retrospective review of case notes and data base.

Methods:

Retrospective review of 14 children with asymptomatic cCMV who underwent cochlear implantation. Their outcome measures were compared with those of a matched population by using standard assessment tools.

Results:

In the study group, the Modified Categories of Auditory Performance (M‐CAP) score (range, 1–7) ranged from 2 to 7 (mean, 4.2). In the control group, the M‐CAP ranged from 5 to 7 (mean, 6.0). In the study group, the Manchester Spoken Language Development Scale (MSLDS) score (range, 1–10) ranged from 1 to 9 (mean, 5.4). In the control group, the MSLDS ranged from 3 to 10 (mean, 8.1).

Conclusions:

Children with asymptomatic deafness caused by cCMV benefit from cochlear implantation but perform less well than a comparable group of children with implants who do not have cCMV. There is a range of performance in the cCMV group that may relate to the degree of motor or cognitive disabilities.
Preliminary evaluation of junior medical students' exposure and comfort with performing the basic head and neck examination
Authors: Wu Edward C. , Passy Victor , Armstrong William B.
Published: May 2011

Objective:

To assess junior medical students' comfort levels in performing the head and neck physical examination (H&NPE) and perception of the importance of otolaryngology—head and neck surgery (OTO‐HNS) in medical training before and after undergoing a department‐led teaching session.

Design:

Anonymous cross‐sectional survey study, before and after educational intervention.

Methods:

One hundred one second‐year medical students participated in an H&NPE teaching session as part of their preclinical curriculum. Students first watched a 25‐minute H&NPE instructional video. Students then participated in lectures (90 minutes) on OTO‐HNS subspecialties and faculty‐ and resident‐led group H&NPE instruction (five to six students each, 90 minutes) with practice on student partners. Students rated their comfort levels (0–5 point Likert scale) in performing the H&NPE and the importance of OTO‐HNS rotations throughout medical training before and after the session.

Results:

Ninety‐five and 77 medical students completed presurveys and postsurveys, respectively. Before the teaching session, students reported an average comfort level of 2.1 in performing the complete H&NPE, which increased to 3.4 (P < .0001) after the session. Similar changes were observed for the individual ear, nose, mouth, and neck exams.

Conclusions:

A specialized teaching session significantly improved medical students' comfort levels in performing the H&NPE and increased their awareness of the importance of OTO‐HNS in medical training immediately after the session.
IONIC DISPLACEMENT AND RECLAMATION OF SALINE‐SODIC SOILS USING CHEMICAL AMENDMENTS AND CROP ROTATION
Authors: Ahmad S. , Ghafoor A. , Akhtar M.E. , Khan M.Z.
Published: May 2011

Biological, chemical and bio‐chemical strategies have been tested in the past for reclamation of saline‐sodic and sodic soils. The efficiency of two crop rotations (rice‐wheat and Sesbania‐wheat) alone or in combination with either gypsum (CaSO4.2H2O) or sulfuric acid (H2SO4) was tested for ionic displacement from four saline‐sodic soils. Pure gypsum was applied at 50 per cent of soil gypsum requirement at the time of planting rice and Sesbania, whereas 95 per cent pure sulfuric acid was added at 50 per cent soil gypsum requirement as one‐third applications by mixing with the first three irrigations. The rice crop biomass decreased at a soil saturation extract electrical conductivity (ECe) of 8 dS m−1, whereas wheat and Sesbania were influenced at a sodium adsorption ratio (SAR) of ≥40. Gypsum treatment helped the crops flourish well at these ECe and SAR levels. The infiltrated volume of water dropped with decrease in ECe : SAR ratio of soils and increase in crop biomass production. Crops rotation treatments alone helped leach sodium (Na+) and other ions successfully at SAR ≤ 21 but were less effective at SAR ≥ 40 at which point plants growth was also curtailed. Gypsum and H2SO4 treatments significantly aided leaching of Na+ and other ions with water at SAR ≥ 40 under both the crop rotations. Hence, crops effectively reclaimed soil at low sodicity level, whereas at high SAR, chemical amendments are obligatory in order to reclaim soils. This study also suggests that the required dose of H2SO4 should be applied with pre‐planting irrigation for better yield of the first crop. Copyright © 2011 John Wiley & Sons, Ltd.
HOX genes are expressed in bovine and mouse oocytes and early embryos
Authors: Paul Delphine , Bridoux Laure , Rezsöhazy René , Donnay Isabelle
Published: May 2011

HOX proteins are transcription factors that play a major role in patterning the body axis of vertebrates from the gastrulation stage. While nothing has been reported so far about their roles at earlier stages, there is evidence that some HOX genes are expressed before gastrulation. The objective of this work was to study the pattern of expression of several HOX genes during oocyte maturation and early embryonic development up to the blastocyst stage. Using nested PCR, HOXD1, HOXA3, HOXD4, HOXB7, HOXB9, and HOXC9 transcripts were detected in bovine oocytes and early embryos at various frequencies depending on the stage of development. Quantitative PCR was performed on bovine oocytes and early embryos: relative expression of HOXD1, HOXA3, and HOXC9 decreased sharply after the 5–8 cell stage. HOXB9 relative expression increased between the oocyte and the morula stage. All transcripts seemed to be of maternal origin before the maternal to embryonic transition, as demonstrated by blocking transcription with α‐amanitin. Reverse transcription was performed with either hexamers or oligo‐dT, allowing for the determination that HOXC9 transcripts were slightly deadenylated during oocyte maturation; HOXD1, HOXA3, and HOXB9 transcripts were not, indicating that they could be translated. Hoxd1, Hoxa3, Hoxb9, and Hoxc9 expression was also detected in mouse oocytes and early embryos. A similar pattern of expression was found in the two species. In conclusion, mammalian HOX genes might be implicated in the control of oocyte maturation, the maternal‐to‐embryonic transition or the first steps of embryo differentiation. Mol. Reprod. Dev. 78:436–449, 2011. © 2011 Wiley‐Liss, Inc.
“Solidarity is a necessity”
Authors: Schubert Ulrich , Remenyi Christian
Published: May 2011

Ulrich Schubert, Professor of Inorganic Chemistry at the Materials Chemistry Institute of the Vienna University of Technology, is Euchems president elect. Nachrichten aus der Chemie asked him about his priorities and aims.
Die Chemie ist zurück
Authors: Bulmahn Maren
Published: May 2011

Viele Unternehmen bauten im letzten Jahr neue Anlagen, denn die alten waren oft fast vollständig ausgelastet. Im Produktportfolio gab es ebenso Änderungen wie beim Personal auf höchster Ebene und mancher meldete Rekordergebnisse.
Vor 50 Jahren geknackt: Der genetische Code
Authors: Weitze Marc‐Denis
Published: May 2011

In der molekularen Evolution nimmt der Code, der die genetische Information mit den funktionellen Molekülen verknüpft, die zentrale Stellung ein. Am 27. Mai jährt sich zum 50. Mal das Experiment, mit dem die Entschlüsselung begann.
Von der Bioregion zum Biotechcluster
Authors: Bengs Holger
Published: May 2011

Deutschland hat fünf international wettbewerbsfähige Biotechregionen: München, Berlin, Heidelberg, das Rheinland und Frankfurt. Größe zieht Erfolg nach sich: Forschungsförderung, Unternehmen und privates Kapital. Doch weiteres Kapital und kritische Masse sind nötig.
Thaumasite: Its Relevance to Sulphate Corrosion in Concrete
Authors: Drábik Milan
Published: May 2011

The simplicity of the formation technology of concrete makes it an important material, one whose range of practical applications has always been several steps ahead of the knowledge of its properties. The increasing number of incidents of serious damage and destruction of concrete and mortar in environments rich in sulphates and carbonates has been a focus of research since several years.
Wer führte wen hinters Licht?
Authors: Adam Wilhelm
Published: May 2011

Bringt ein raffinierter Fälscher begehrte Bilder auf den Markt, enttarnt selten jemand die Fälschung.
Fachinformationszentrum Chemie: Wie geht es weiter?
Authors: Eckermann Ruben
Published: May 2011

Der Senat der Leibniz‐Gemeinschaft empfiehlt, das Fachinformationszentrum Chemie nicht weiter zu fördern, weil es sich zu zögerlich neu ausgerichtet habe. Dies widerspricht teilweise dem Bericht der Bewertungsgruppe, welche die Angebote als zukunftsfähig und förderwürdig einstufte.
Bandwidth allocation under end‐to‐end percentile delay bounds
Authors: Anjum Bushra , Perros Harry , Mountrouidou Xenia , Kontovasilis Kimon
Published: May 2011

We describe an efficient and accurate approximation method for calculating the bandwidth that should be allocated on each link along the path of a point‐to‐point Multiprotocol Label Switching connection, so that the end‐to‐end delay D is less than or equal to a given value T with a probability γ, that is, P(D ≤ T) = γ. We model a connection by a tandem queuing network of infinite capacity queues. The arrival process of packets to the connection is assumed to be bursty and correlated and it is depicted by a two‐stage Markov‐Modulated Poisson Process. The service times are exponentially distributed. The proposed method uses only the first queue of the tandem queuing network to construct an upper and lower bound of the required bandwidth so that P(D ≤ T) = γ. Subsequently, we estimate the required bandwidth using a simple interpolation function between the two bounds. Extensive comparisons with simulation showed that the results obtained have an average relative error of 1.25%. Copyright © 2011 John Wiley & Sons, Ltd.
A new exact, closed‐form a priori global error estimator for second‐ and higher‐order time‐integration methods for linear elastodynamics
Authors: Idesman A.
Published: May 2011

In our recent papers, we suggested a new two‐stage time‐integration procedure for linear elastodynamics problems and showed that for long‐term integration, time‐integration methods with zero numerical dissipation are very effective for all linear elastodynamics problems, including structural dynamics, wave propagation and impact problems. In this paper, we have derived a new exact, closed‐form a priori global error estimator for time integration of linear elastodynamics by the trapezoidal rule and the high‐order time continuous Galerkin (TCG) methods with zero numerical dissipation (these methods correspond to the diagonal of the Padé approximation table). The new a priori global error estimator allows the selection of the size (the number) of time increments for the indicated time‐integration methods at the prescribed accuracy as well as the comparison of the effectiveness of the second‐ and high‐order TCG methods at different observation times. A numerical example shows a good agreement between theoretical and numerical results. Copyright © 2011 John Wiley & Sons, Ltd.
Quantitative phosphoproteomics reveals link between Helicobacter pylori infection and RNA splicing modulation in host cells
Authors: Holland Carsten , Schmid Monika , Zimny‐Arndt Ursula , Rohloff John , Stein Robert , Jungblut Peter R. , Meyer Thomas F.
Published: May 2011

The Gram‐negative, spiral‐shaped bacterium Helicobacter pylori is a common human pathogen that causes chronic inflammation of the human gastric mucosa, leading to peptic ulceration and/or gastric cancer. Here, we analyzed changes in the phosphoproteome of gastric epithelial cells (AGS) upon infection with H. pylori using a combination of SILAC, phosphoprotein enrichment, 2‐DE, and MALDI TOF/TOF‐MS. From a total of 526 spots we identified 391 protein species (143 proteins) and quantified 332 (127 proteins). Nearly, one‐third of the identified proteins (40/143) were associated with the spliceosome or RNA splicing. The abundance of 20 proteins was altered by H. pylori infection, in particular, a number of serine arginine‐rich (SR) proteins involved in the regulation and control of alternative splicing. Importantly, the combined methodologies enabled the detection of infection‐dependent protein species‐specific regulation, suggesting functional modulation of individual protein species. These findings reveal unexpected new insights into the mechanisms of host cell manipulation by H. pylori, which are likely associated with gastric pathologies, including gastric cancer.
Sequential functionalization of janus‐type dendrimer‐like poly(ethylene oxide)s with camptothecin and folic acid
Authors: Feng Xiaoshuang , Pinaud Julien , Chaikof Elliot L. , Taton Daniel , Gnanou Yves
Published: May 2011

Janus‐type dendrimer‐like poly(ethylene oxide)s (PEOs) of 1st, 2nd, and 3rd generation carrying terminal hydroxyl functions on one side and cleavable ketal groups on the other were used as substrates to conjugate folic acid as a folate receptor and camptothecin (CPT) as a therapeutic drug in a sequential fashion. The conjugation of both FA and CPT was accomplished by “click chemistry” based on the 1,3 dipolar cycloaddition coupling reaction. First, the hydroxyl functions present at one face of Janus‐type dendrimer‐like PEOs were transformed into alkyne groups through a simple Williamson‐type etherification reaction. Next, the ketals carried by the other face of the dendrimer‐like PEOs were hydrolyzed, yielding twice as many hydroxyls which were subsequently subjected to an esterification reaction using 2‐bromopropionic bromide. Before substituting azides for the bromide of 2‐bromopropionate esters just generated in the presence of NaN3, an azido‐containing amidified FA derivative was reacted through click chemistry with alkyne functions introduced on the other face of the dendrimer‐like PEOs. A purposely designed alkyne‐functionalized biomolecule derived from CPT was conjugated to the azido functions carried by the dendritic PEOs by a second “click reaction.” In this case, twice as many CPT as FA moieties were finally conjugated to the two faces of the Janus‐type dendrimer‐like PEOs, the numbers of folate and CPT introduced being 2 and 4, 4 and 8, and 8 and 16 for samples of 1st, 2nd, and 3rd generation, respectively (route A). An alternate route for functionalizing the dendrimer‐like PEO of 1st generation consisted, first, in conjugating the azido‐containing CPT onto the alkyne groups present on one face of the dendritic PEO scaffold. The alkyne‐functionalized FA was further introduced by click chemistry after the bromides of 2‐bromopropionate esters were chemically transformed into azido groups. The corresponding prodrug thus contains 2 CPT and 4 FA external moieties (route B). Every reaction step product was thoroughly characterized by 1H NMR spectroscopy. A preliminary investigation into the water solution properties of these functionalized dendritic PEOs is also presented. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Synthesis of polyacrylonitrile by single‐electron transfer‐living radical polymerization using Fe(0) as catalyst and its adsorption properties after modification
Authors: Liu Delong , Chen Hou , Yin Ping , Ji Naiyi , Zong Guangxi , Qu Rongjun
Published: May 2011

Fe(0) was firstly used as single‐electron transfer‐living radical polymerization catalyst for acrylonitrile polymerization using carbon tetrachloride as initiator, hexamethylenetetramine as N‐ligand, and N,N‐dimethylformamide as the solvent at 65 °C. First‐order kinetic studies indicated that this polymerization proceeded in a “living”/controlled manner. The living nature of the polymerization was also confirmed by chain extension of methyl methacrylate with polyacrylonitrile (PAN) as macroinitiator. Furthermore, PAN was modified with NH2OH·HCl to generate amidoxime groups for extraction of heavy metal ions (Hg2+) from aqueous solutions. Fourier transformed infrared spectroscopy was performed to characterize chemical composition and structure. The adsorption property of Hg2+ was investigated at different pH values of aqueous solutions and distilled water. The maximal saturated adsorption capacity of Hg2+ was 4.8 mmol g−1. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Influence of kinetics of drug binding on EGFR signaling: A comparative study of three EGFR signaling pathway models
Authors: Bairy Sneha , Wong Chung F.
Published: May 2011

We used three models of the epidermal growth factor receptor (EGFR) signaling pathway mimicking three different cell lines to study the effects of kinetics of drug binding on influencing molecular signaling in the pathways. With no incubation of drugs before the external cue epidermal growth factor (EGF) was applied, we found that fast kinetics of binding to protein kinases was advantageous in suppressing the production of the Extracellular signal‐regulated kinase (ERK) that triggers cell proliferation, with some exceptions. Incubation of a drug with a protein kinase target for an hour before a pathway was initiated with an external cue made kinetics less significant, so did high concentration of drugs. In addition, we found that applying a drug to a protein kinase mostly affected downstream signaling although upstream events were also affected in a few cases. In examining whether applying two drugs to two protein kinase targets in the pathways could produce synergistic effects, we found positive, negative, or no effects, depending on the protein kinases targeted and the pathway model considered. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Influence of doping on the structure and optical characteristics of Ge2Sb2Te5 amorphous films
Authors: Kozyukhin Sergey , Kudoyarova Vera , Nguyen Huy Phuc , Smirnov Alexander , Lebedev Viktor
Published: May 2011

The influence of doping on the structural and optical characteristics of Ge2Sb2Te amorphous thin films has been determined with micro‐Raman scattering spectroscopy and a variable incident angle spectroscopic ellipsometer (VASE). The measured Raman spectra revealed the existence of two overlapping bands B2 near 130 cm‐1 and C1 near 150 cm‐1. The additional small features in the responses were revealed in the range less than 100 cm‐1. Suggest that micro‐Raman scattering spectroscopy can be used to study phase change materials through local structural information. The distinct changes in refractive index and extinction coefficient of Ge2Sb2Te amorphous films due to doping were revealed in the visible range. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Water‐based sonochemical cleaning in the manufacturing of high‐efficiency photovoltaic silicon wafers
Authors: Nadtochiy A. , Podolian A. , Korotchenkov O. , Schmid J. , Kancsar E. , Schlosser V.
Published: May 2011

We found that organic particle contaminants are effectively removed during ultrasonic cleaning in distilled water, as evidenced by the disappearance of organic‐related absorption peaks and remarkable shortening of the surface photovoltage decay transients (SPV). SPV decay transient mappings obtained with a 100‐μm spatial resolution (see abstract figure) show that, in multicrystalline Si wafers, the resulting effect on the decay time is markedly non‐uniform compared with that observed in crystalline Si, implying the existence of a mechanism associated with the grain boundaries. The data are tentatively interpreted in terms of the wafer hydrogenization, which most probably occur through the grain boundaries. It is assumed that elevated temperatures inside a cavitating bubble may lead to water and bubble gas decomposition, accompanied by a subsequent trapping of the decomposed particulates at the silicon surface. These particulates can then be predominantly incorporated into the grain boundary regions. We suggest that this can be in part due to hydrogen molecules decomposed in water which are mobile in silicon (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electronic and optical properties of ZnCr2Se4 as explored by first principles and crystal field calculations
Authors: Avram Nicolae M. , Brik Mikhail G. , Sildos Ilmo
Published: May 2011

Optical, structural, electronic and elastic properties of ZnCr2Se4 have been theoretically modelled using two different approaches: semi‐empirical model of crystal field and ab initio DFT‐based calculations. The former allows for calculations of electronic levels of six‐fold coordinated Cr3+ ions in a crystal field and direct comparison with experimental absorption spectra. The latter allows for analysis of the band structure, density of states, elastic properties and pressure effects for the considered compound. All obtained results are compared with corresponding experimental values; good agreement between the results of calculations and experimental data was demonstrated (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Collective modes of a bilayer double parabolic quantum well spin polarized electron gas
Authors: Campbell Colin , Tifrea Ionel
Published: May 2011

We investigate the possible electromagnetically induced collective excitation modes in a bilayer quasi‐two‐dimensional structure build from two adjacent parabolic quantum wells (PQW). We consider both charge and spin excitation modes within and beyond the random phase approximation method. To account for higher order effects we used exchange and correlation spin‐dependent local field correction factors. We analyzed intra‐ and inter‐subband excitations and provide analytic results for their excitation frequencies in the long wavelength limit. In particular, we analyze the spin polarization dependence of the lowest frequency spin density mode and show that its relevant frequency is in the hundred GHz region. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fault detection for batch monitoring and discrete wavelet transforms
Authors: Li, Fang , Church, George , Janakiram, Mani , Gholston Howard , Runger George
Published: May 2011

Batch operations are encountered in many industries and measurements are often recorded from automated sensors. It is important to determine whether an unknown batch is normal or unusual given a set of reference batches from normal operations. The measurements from a single batch can contain temporal readings that comprise a large time series. A discrete wavelet transformation (DWT) is applied to use the time and frequency localization of wavelets to extract features. A large number of coefficients can result and several methods to create summary features from the denoised coefficients obtained from DWT are compared. Also, a new summary feature incorporates information from denoised wavelet coefficients. The proposed study considers discrete wavelet‐decompositions combined with principal component analyses to summarize batch characteristics. Results were validated on an industry data set. Copyright © 2011 John Wiley & Sons, Ltd.
Using a modified genetic algorithm to find feasible regions of a desirability function
Authors: Wan Wen , Birch Jeffrey B.
Published: May 2011

The multi‐response optimization (MRO) problem in response surface methodology is quite common in applications. Most of the MRO techniques such as the desirability function method by Derringer and Suich are utilized to find one or several optimal solutions. However, in fact, practitioners usually prefer to identify all of the near‐optimal solutions, or all feasible regions, because some feasible regions may be more desirable than others based on practical considerations. In this paper, with benefits from the stochastic property of a genetic algorithm (GA), we present an innovative procedure using a modified GA (MGA), a computational efficient GA with a local directional search incorporated into the GA process, to approximately generate all feasible regions for the desirability function without the limitation of the number of factors in the design space. The procedure is illustrated through a case study. The MGA is also compared with other commonly used methods for determining the set of feasible regions. Using Monte Carlo simulations with two benchmark functions and a case study, it is shown that the MGA can more efficiently determine the set of feasible regions than the GA, grid methods, and the Nelder–Mead simplex algorithm. Copyright © 2011 John Wiley & Sons, Ltd.
Assessment of binary inspection with a hybrid measurand
Authors: Erdmann Tashi P. , de Mast Jeroen
Published: May 2011

This paper addresses issues that arise in measurement system analysis of a binary measurement system if the measurand is a hybrid between a dichotomy and a continuum. A case study is presented, which illustrates methods to assess the error rates of binary measurements with such a hybrid measurand. The case study concerns pass/fail inspection of laptop screens for scratches, where the measurand is the presence or absence of scratches. If a scratch is present, the measurand corresponds with a continuum of scratch sizes, but if no scratch is present, the measurand corresponds with a point. It is argued that if the measurand is a hybrid, a standard logistic regression model is not suitable to estimate the characteristic curve relating the reject probability with the measurand. Several alternative specifications for the characteristic curve are introduced and compared. We conclude that many of the methods currently used for assessment of a binary measurement system with a hybrid measurand are unsuited. This is a remarkable conclusion, given the frequent occurrence in industry of leak tests, inspections for defects, and other binary measurement systems with a hybrid measurand. Copyright © 2011 John Wiley & Sons, Ltd.
Direct ab initio dynamics study of the reaction of C2(A3Πu) with CH4
Authors: Huo Rui‐Ping , Huang Xu‐Ri , Li Ji‐Lai , Zhang Xiang , Li Na , Sun Chia‐Chung
Published: May 2011

The reaction of C2(A3Πu) with CH4 has been investigated over a wide temperature range 200–3,000 K by direct ab initio dynamics method at the BMC‐CCSD//BB1K/6‐311+G(2d,2p) level of theory. The optimized geometries and frequencies of the stationary points are calculated at the BB1K/6‐311+G(2d,2p) level, and then the energy profiles of the reactions are refined using the BMC‐CCSD method. The activation barrier height for H‐abstraction reaction was calculated to be 4.44 kcal/mol in temperature range (337–605 K), and the electron transfer behavior was also analyzed by quasi‐restricted molecular orbital method in detail. The canonical variational transition‐state theory (CVT) with the small curvature tunneling (SCT) correction method is used to calculate the rate constants over a wide temperature range 200–3,000 K. The theoretical results shows that variational effect is to some extent large in lower temperature range, and small curvature and tunneling effect play important roles to the H‐atom abstraction only at lower temperatures. The CVT/SCT rate constants are in good agreement with the available experimental results. Our theoretical study is expected to provide a direct insight into the reaction mechanism and may be useful for estimating the kinetics of the title reaction over a wide temperature range where no experimental data are available so far. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012
Reactions of 1S, 1D, and 3P carbon atoms with water. Oxygen abstraction and intermolecular formaldehyde generation mechanisms; An MCSCF study
Authors: Ozkan Ilker , Dede Yavuz
Published: May 2011

Reactions of singlet and triplet carbon atoms with water are explored theoretically using CASSCF–MCQDPT2, CCSD, and DFT methodologies. The 1S carbons are found to be unreactive. Depending on the carbon atom generation method and the reaction medium, gas‐phase C(3P) attacking water may generate CO and atomic hydrogen as the end products. Reaction paths of the C(1D) + H2O system are complicated due to the involvement of two reactive potential energy surfaces with branchings occurring along each. Modifications in product distributions for reactions taking place in condensed phases are elaborated. The decisive reaction conditions, under which the oxygen abstraction and intermolecular formaldehyde generation dominate, are suggested to clarify the discrepancy related with experimental CO observation. The findings are consistent with available experimental data on this system. Oxygen abstraction and intermolecular formaldehyde generation mechanisms suggested here are capable of serving as models for similar reactions of alcohols. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012