bluuebunny/crossref_metadata_2025 huggingface dataset:
The splicing regulator PTBP2 controls a program of embryonic splicing required for neuronal maturation
Authors: Li Qin , Zheng Sika , Han Areum , Lin Chia-Ho , Stoilov Peter , Fu Xiang-Dong , Black Douglas L
Published: January 2014

We show that the splicing regulator PTBP2 controls a genetic program essential for neuronal maturation. Depletion of PTBP2 in developing mouse cortex leads to degeneration of these tissues over the first three postnatal weeks, a time when the normal cortex expands and develops mature circuits. Cultured Ptbp2−/− neurons exhibit the same initial viability as wild type, with proper neurite outgrowth and marker expression. However, these mutant cells subsequently fail to mature and die after a week in culture. Transcriptome-wide analyses identify many exons that share a pattern of mis-regulation in the mutant brains, where isoforms normally found in adults are precociously expressed in the developing embryo. These transcripts encode proteins affecting neurite growth, pre- and post-synaptic assembly, and synaptic transmission. Our results define a new genetic regulatory program, where PTBP2 acts to temporarily repress expression of adult protein isoforms until the final maturation of the neuron.
Modes of flagellar assembly in Chlamydomonas reinhardtii and Trypanosoma brucei
Authors: Höög Johanna L , Lacomble Sylvain , O’Toole Eileen T , Hoenger Andreas , McIntosh J Richard , Gull Keith
Published: January 2014

Defects in flagella growth are related to a number of human diseases. Central to flagellar growth is the organization of microtubules that polymerize from basal bodies to form the axoneme, which consists of hundreds of proteins. Flagella exist in all eukaryotic phyla, but neither the mechanism by which flagella grow nor the conservation of this process in evolution are known. Here, we study how protein complexes assemble onto the growing axoneme tip using (cryo) electron tomography. In Chlamydomonas reinhardtii microtubules and associated proteins are added simultaneously. However, in Trypanosoma brucei, disorganized arrays of microtubules are arranged into the axoneme structure by the later addition of preformed protein complexes. Post assembly, the T. brucei transition zone alters structure and its association with the central pair loosens. We conclude that there are multiple ways to form a flagellum and that species-specific structural knowledge is critical before evaluating flagellar defects.
One size does not fit all
Authors: Tautz Diethard
Published: January 2014

Comparing the anatomies of more than 100 different species of ants reveals that worker ants have enlarged necks, not seen in queens, that allow them to lift and carry objects many times heavier than themselves.
Error analysis of ellipsoidal mirrors for soft X-ray focusing by wave-optical simulation
Authors: Motoyama Hiroto , Saito Takahiro , Mimura Hidekazu
Published: January 2014

The ellipsoidal mirror is an ideal soft X-ray focusing optic that enables achromatic and highly efficient focusing to a nanometer spot size; however, a high-quality surface is necessary for ideal focusing. Knowledge of the required figure accuracy is important for fabrication. In this paper, we analyze the effects of figure errors on the focusing performance through wave-optical calculations based on the Fresnel–Kirchhoff diffraction theory, assuming coherent soft X-rays. Figure errors are classified into three types from the viewpoint of manufacturing. The effect of the alignment error is also investigated. The analytical results quantitatively indicate criteria regarding figure accuracy, which are expected to be essential for the development of high-performance ellipsoidal soft X-ray focusing mirrors.
Shear Wave Elastography for Evaluation of Liver Fibrosis
Authors: Ferraioli Giovanna , Parekh Parth , Levitov Alexander B. , Filice Carlo
Published: January 2014

The prognosis and management of chronic viral hepatitis mainly depend on the extent of liver fibrosis, particularly in chronic hepatitis C. Liver histologic analysis is still considered the reference standard in the assessment of liver fibrosis despite the interobserver and interobserver variability in staging and some morbidity and mortality risks. Thus, noninvasive methods for assessing liver fibrosis are of great clinical interest. In the last decade, ultrasound‐based techniques to estimate the stage of liver fibrosis have become commercially available. They all have the capability to noninvasively evaluate differences in the elastic properties of soft tissues by measuring tissue behavior when a mechanical stress is applied. Shear wave elastography relies on the generation of shear waves determined by the displacement of tissues induced by the force of a focused ultrasound beam or by an external push. This article reviews the results that have been obtained with shear wave elastography for assessment of liver fibrosis.
Combined Value of Virtual Touch Tissue Quantification and Conventional Sonographic Features for Differentiating Benign and Malignant Thyroid Nodules Smaller Than 10 mm
Authors: Zhang Huiping , Shi Qiusheng , Gu Jiying , Jiang Luying , Bai Min , Liu Long , Wu Ying , Du Lianfang
Published: January 2014

Objectives

This study aimed to investigate the value of sonographic features including Virtual Touch tissue quantification (VTQ; Siemens Medical Solutions, Mountain View, CA) for differentiating benign and malignant thyroid nodules smaller than 10 mm.

Methods

Seventy‐one thyroid nodules smaller than 10 mm with pathologic diagnoses were included in this study. The conventional sonographic features and quantitative elasticity features (VTQ) were observed and compared between benign and malignant nodules.

Results

There were 39 benign and 32 malignant nodules according to histopathologic examination. When compared with benign nodules, malignant nodules were more frequently taller than wide, poorly defined, and markedly hypoechoic (P < .05). Color Doppler sonographic features were not significantly different between benign and malignant nodules. The VTQ value for malignant nodules (mean ± SD 3.260 ± 0.725 m/s) was significantly higher than that of benign ones (2.108 ± 0.455 m/s; P < .001). The cutoff point for the differential diagnosis was 2.910 m/s, with sensitivity, specificity, a positive predictive value, a negative predictive value, and diagnostic accuracy of 71.9%, 100%, 100%, 81.2%, and 87.3% respectively. Logistic regression analysis showed that a taller‐than‐wide shape, a poorly defined boundary, marked hypoechogenicity, and a VTQ value greater than 2.910 m/s were independent risk factors for malignancy, with odds ratios of 69.366, 41.864, 5.945, and 64.991. The combination of VTQ with a taller‐than‐wide shape had the highest sensitivity and specificity of 90.6% and 97.4%.

Conclusions

The shape, margin, echogenicity, and VTQ value are useful sonographic criteria for differentiating benign and malignant thyroid nodules smaller than 10 mm. When VTQ was combined with B‐mode sonographic features, the sensitivity was improved significantly.
Evaluation of a New 3‐Dimensional Color Doppler Flow Method to Quantify Flow Across the Mitral Valve and in the Left Ventricular Outflow Tract
Authors: Kimura Sumito , Streiff Cole , Zhu Meihua , Shimada Eriko , Datta Saurabh , Ashraf Muhammad , Sahn David J.
Published: January 2014

Objectives

The aim of this study was to assess the accuracy, feasibility, and reproducibility of determining stroke volume from a novel 3‐dimensional (3D) color Doppler flow quantification method for mitral valve (MV) inflow and left ventricular outflow tract (LVOT) outflow at different stroke volumes when compared with the actual flow rate in a pumped porcine cardiac model.

Methods

Thirteen freshly harvested pig hearts were studied in a water tank. We inserted a latex balloon into each left ventricle from the MV annulus to the LVOT, which were passively pumped at different stroke volumes (30–80 mL) using a calibrated piston pump at increments of 10 mL. Four‐dimensional flow volumes were obtained without electrocardiographic gating. The digital imaging data were analyzed offline using prototype software. Two hemispheric flow‐sampling planes for color Doppler velocity measurements were placed at the MV annulus and LVOT. The software computed the flow volumes at the MV annulus and LVOT within the user‐defined volume and cardiac cycle.

Results

This novel 3D Doppler flow quantification method detected incremental increases in MV inflow and LVOT outflow in close agreement with pumped stroke volumes (MV inflow, r = 0.96; LVOT outflow, r = 0.96; P < .01). Bland‐Altman analysis demonstrated overestimation of both (MV inflow, 5.42 mL; LVOT outflow, 4.46 mL) with 95% of points within 95% limits of agreement. Interobserver variability values showed good agreement for all stroke volumes at both the MV annulus and LVOT.

Conclusions

This study has shown that the 3D color Doppler flow quantification method we used is able to compute stroke volumes accurately at the MV annulus and LVOT in the same cardiac cycle without electrocardiographic gating. This method may be valuable for assessment of cardiac output in clinical studies.
Sex Differences Between Vascular Endothelial Function and Carotid Intima‐Media Thickness by Framingham Risk Score
Authors: Yao Fengjuan , Liu Yanqiu , Liu Donghong , Wu Suhua , Lin Hong , Fan Rui , Li Cuiling
Published: January 2014

Objectives

To investigate sex differences associated with changes in brachial artery flow‐mediated dilatation and carotid intima‐media thickness by Framingham Risk Score.

Methods

The study included 1083 patients aged 30 to 80 years. According to the Framingham Risk Score, patients were divided into 3 groups: low, mid, and high risk. Traditional cardiovascular risk factors such as age, sex, smoking, diabetes, hypertension, and cholesterol were assessed by Framingham Risk Score, as well as laboratory and vascular parameters, including flow‐mediated dilatation and intima‐media thickness. Correlations between flow‐mediated dilatation, intima‐media thickness, and the Framingham Risk Score were analyzed by sex.

Results

Compared with women, flow‐mediated dilatation in men was significantly lower in the low‐risk group (mean ± SD, 8.31% ± 2.89% versus 9.76% ± 3.62%; P< .001) but significantly higher in the mid‐ and high‐risk groups (mid‐risk, 7.43% ± 2.65% versus 6.67% ± 2.42%; high‐risk, 6.41% ± 2.27% versus 5.78% ± 2.39%; P< .001). Flow‐mediated dilatation decreased with an increasing Framingham Risk Score in both sexes but especially in women. Although intima‐media thickness increased with the Framingham Risk Score in both sexes, there was no significant sex difference between the groups. Univariate analysis showed significant negative correlations between flow‐mediated dilatation and the Framingham Risk Score in both sexes (Rmen = −0.308; P < .001; Rwomen = −0.572; P < .001) and flow‐mediated dilatation and intima‐media thickness (Rmen = −0.295; P < .001; Rwomen = −0.474; P< .001). There was a significant positive correlation between intima‐media thickness and the Framingham Risk Score (Rmen = 0.571; P< .001; Rwomen = 0.633; P < .001).

Conclusions

A sex difference existed only for flow‐mediated dilatation at the same Framingham risk level. Flow‐mediated dilatation might be more sensitive than intima‐media thickness for detecting sex differences in vascular dysfunction, according to Framingham risk stratification in a Chinese population.
Reference Ranges for Ductus Venosus Velocity Ratios in Pregnancies With Normal Outcomes
Authors: Turan Ozhan M. , Turan Sifa , Sanapo Laura , Wilruth Arne , Berg Christoph , Gembruch Ulrich , Harman Christopher R. , Baschat Ahmet A.
Published: January 2014

Objectives

The purpose of this study was to establish reference ranges for ductus venosus velocity ratios.

Methods

Singleton pregnancies from 11 to 38 weeks with exactly established gestational ages (GAs) were recruited for the study. Pregnancies with fetal anomalies, growth abnormalities, maternal medical complications, stillbirth, birth weight below the 10th or above the 90th percentile, and neonatal anomalies were excluded. The ductus venosus pulsatility index for veins (PIV) and velocity ratios (S/v, S/D, v/D, S/a, v/a, and D/a, where S indicates ventricular systole [s‐wave], v, ventricular end‐systolic relaxation [v‐descent], D, passive diastolic ventricular filling [D‐wave], and a, active ventricular filling during atrial systole [a‐wave]) were calculated. Separate regression models were fitted to estimate the mean and standard deviation at each GA for each ratio.

Results

A total of 902 velocity wave ratios and ductus venosus PIVs were used for reference ranges. The S/v, S/D, and v/D ratios were not changed with GA (P > .05 for all). The PIV and S/a, v/a, and D/a ratios were reduced with GA (P < .0001 for all). Significant reductions in the means and standard deviations of the PIV and S/a, v/a, and D/a ratios were observed between 17 and 18 weeks' gestation. Therefore, nomograms were separately created between 11 and 17 weeks and 18 and 38 weeks.

Conclusions

We created reference ranges for ductus venosus velocity ratios between 11 and 38 weeks' gestation in normal pregnancies. These reference ranges may prove beneficial for evaluation of fetal conditions that are associated with cardiovascular abnormalities.
Quantitative Analysis of Copy Number Variants Based on Real‐Time LightCycler PCR
Authors: Ma Lijiang , Chung Wendy K.
Published: January 2014

Quantitative real‐time PCR is PCR visualized in real time by the use of fluorescent or intercalating dyes, which are employed to measure gene expression or gene quantification including contiguous gene deletions or duplications. A simple method is described here to quantify DNA copy number from human samples. Curr. Protoc. Hum. Genet. 80:7.21.1‐7.21.8. © 2014 by John Wiley & Sons, Inc.
Design of Large‐Insert Jumping Libraries for Structural Variant Detection Using Illumina Sequencing
Authors: Hanscom C. , Talkowski M.
Published: January 2014

Next‐generation sequencing is an important and efficient tool for the identification of structural variation, particularly balanced chromosomal rearrangements, because such events are not routinely detected by microarray and localization of altered regions by karyotype is imprecise. Indeed, the degree of resolution that can be obtained through next‐generation technologies enables elucidation of precise breakpoints and has facilitated the discovery of numerous pathogenic loci in human disease and congenital anomalies. The protocol described here explains one type of large‐insert “jumping library” and the steps required to generate such a library for multiplexed sequencing using Illumina sequencing technology. This approach allows for cost‐efficient multiplexing of samples and provides a very high yield of fragments with large inserts, or “jumping” fragments. Curr. Protoc. Hum. Genet. 80:7.22.1‐7.22.9. © 2014 by John Wiley & Sons, Inc.
Internet Resources in Medical Genetics
Authors: Waggoner Darrel J.
Published: January 2014

This unit presents an overview of the most commonly used Web‐based information resources for clinicians seeking to apply molecular or array‐based genetic testing to patient care, learn more about newborn screening, or understand the molecular basis of inherited diseases. It is also for consumers seeking advocacy or scientific/management information, and for genetics professional societies. Curr. Protoc. Hum. Genet. 80:9.12.1‐9.12.8. © 2014 by John Wiley & Sons, Inc.
Retroviral Vector Production
Authors: Miller A. Dusty
Published: January 2014

In this unit, the basic protocol generates stable cell lines that produce retroviral vectors that carry selectable markers. Also included are an alternate protocol that applies when the retroviral vector does not carry a selectable marker, and another alternate protocol for rapidly generating retroviral vector preparations by transient transfection. A support protocol describes construction of the retroviral vectors. The methods for generating virus from retroviral vector plasmids rely on the use of packaging cells that synthesize all of the retroviral proteins but do not produce replication‐competent virus. Additional protocols detail plasmid transfection, virus titration, assay for replication‐competent virus, and histochemical staining to detect transfer of a vector encoding alkaline phosphatase. Curr. Protoc. Hum. Genet. 80:12.5.1‐12.5.22. © 2014 by John Wiley & Sons, Inc.
Can we test for the maximum possible earthquake magnitude?
Authors: Holschneider M. , Zöller G. , Clements R. , Schorlemmer D.
Published: January 2014

We explore the concept of maximum possible earthquake magnitude,M, in a region represented by an earthquake catalog from the viewpoint of statistical testing. For this aim, we assume that earthquake magnitudes are independent events that follow a doubly truncated Gutenberg‐Richter distribution and focus on the upper truncationM. In earlier work, it has been shown that the value ofMcannot be well constrained from earthquake catalogs alone. However, for two hypothesized valuesMandM′, alternative statistical tests may address the question: Which value is more consistent with the data? In other words, is it possible to reject a magnitude within reasonable errors, i.e., the error of the first and the error of the second kind? The results for realistic settings indicate that either the error of the first kind or the error of the second kind is intolerably large. We conclude that it is essentially impossible to inferMin terms of alternative testing with sufficient confidence from an earthquake catalog alone, even in regions like Japan with excellent data availability. These findings are also valid for frequency‐magnitude distributions with different tail behavior, e.g., exponential tapering. Finally, we emphasize that different data may only be useful to provide additional constraints forM, if they do not correlate with the earthquake catalog, i.e., if they have not been recorded in the same observational period. In particular, long‐term geological assessments might be suitable to reduce the errors, while GPS measurements provide overall the same information as the catalogs.
Short‐term upwelling events at the western African coast related to synoptic atmospheric structures as derived from satellite observations
Authors: Desbiolles F. , Blanke B. , Bentamy A.
Published: January 2014

Satellite scatterometers provide continuously valuable surface wind speed and direction estimates over the global ocean on a regular grid both in space and time. The Level 3 data derived from the Advanced Scatterometer (ASCAT), available at 1/4° spatial resolution (hereafter AS25), and Quick Scatterometer (QuikSCAT), available on 1/2° and 1/4° horizontal grids (QS50 and QS25, respectively), are studied at regional scales in both the Benguela and Canary upwelling systems. They are compared to the European Center for Medium‐Range Weather Forecast surface wind analysis, with insight into their intrinsic and actual spatial resolutions. In the coastal band, the finest spatial patterns are found in the QS25 winds and are O(75 km). This demonstrates the sensitivity of the high‐resolution satellite‐derived winds to coastal processes related to sea surface temperature (SST) perturbations and land‐sea transition. Next, short‐lived upwelling episodes (SUEs) calculated from SST anomalies are defined consistently with the QS25 actual resolution. These cold events refer to local, short‐lived perturbations that add to seasonal upwelling variability. We characterize concomitant atmospheric synoptic conditions for SUEs identified at chosen latitudes and highlight two subregions in both upwelling systems, with contrasted patterns for the alongshore wind stress component and curl. The complexity of the latter patterns is closely linked to local, short‐term SST variability. Closer to the shore, numerical sensitivity experiments show that the imbalance between Ekman transport and Ekman pumping has an impact on ocean dynamics: wind reduction in the coastal QS25 forcing, partially induced by orography, tends to reduce coastal SST cooling.
Basement shear zones development and shortening kinematics in the Ecrins Massif, Western Alps
Authors: Bellanger M. , Bellahsen N. , Jolivet L. , Baudin T. , Augier R. , Boutoux A.
Published: January 2014

In the Western Alps, Oligocene shortening affected a highly heterogeneous European crust with Liassic half‐grabens inherited from the rifting stage and the finite deformation was strongly partitioned between the rigid basement and the weak Jurassic sediments. In the Ecrins Massif (Oisans, external crystalline massifs), where the half‐grabens are best exposed and preserved, compressional structures within the basement have to date never been described in details. This massif was shortened under moderate metamorphic conditions (250–350°C and 0.1–0.5 GPa), and the rheological contrast between the basement and the cover is strong. While the sediments are intensely folded, the cover‐basement interface presents apparent open folds underlined by the Lower Triassic layers. The basement itself shows a more localized deformation along several brittle‐ductile shear zones. We here report new evidences of such brittle‐ductile shear zones characterized by anastomosed phyllonitic shear bands rich in phengite and quartz, a low‐strength material where strain has localized. New detailed maps of reverse shear zones, faults, schistosity, and stretching lineations in both the cover and the basement are provided. We show that the Oligocene crustal shortening was mainly E‐W to ENE‐WSW. Local N‐S to NW‐SE shortening occurred and was limited to the eastern border of the Ecrins Massif, around the Penninic Frontal Thrust, which likely was a sinistral transpressive structure in this area. Finally, new balanced cross sections show that these basement shear zones have accommodated more than 50% of the Oligocene crustal shortening.
Modes of stepwise eastward migration of the northern Tyrrhenian Sea back‐arc extension: Evidences from the northern Latium offshore (Italy)
Authors: Buttinelli M. , Scrocca D. , De Rita D. , Quattrocchi F.
Published: January 2014

The structural architecture of a portion of the eastern side of the Tyrrhenian Sea back‐arc basin has been defined reinterpreting a public data set made up by seismic reflection profiles. A detailed reconstruction of the extensional front migration trough time across the area has been achieved. Migration has been defined by identifying the generation of unconformities in the graben‐like basins developed in the area, as due to the activation and deactivation of normal faults. Such phenomena are part of a tectonic process that also involved blocks rotation, crustal thinning, and stretching. Syn‐rift extension affected the area since the early to middle Miocene (our estimate), principally interesting the north‐westernmost sectors. During late Miocene and throughout the Plio‐Quaternary the extensional front moved stepwise toward the southeastern and eastern sectors. Widespread postrift conditions established over the whole area since the late Pliocene to early Pleistocene. Since the Quaternary, the locus of active extension further migrated toward the present onshore area, where a pronounced volcanic phase developed. In this evolutionary framework the rates of observed migration could be correlated with the acceleration of Calabrian slab rollback since Pliocene. Furthermore, direct evidences of magmatism were not recognized in the offshore. Although the observed crustal thinning, the absence of volcanic bodies in the study area could be related to normal faults which were unable to sufficiently extend the crust, in association with lower crust and mantle processes unable to produce melts.
More Than One Million Years of History in Lake Ohrid Cores
Authors: Wagner Bernd , Wilke Thomas , Krastel Sebastian , Zanchetta Giovanni , Sulpizio Roberto , Reicherter Klaus , Leng Melanie , Grazhdani Andon , Trajanovski Sasho , Levkov Zlatko , Reed Jane , Wonik Thomas
Published: January 2014

Continental scientific drilling is an important tool for exploring natural and anthropogenic processes on Earth. In past decades the results obtained from lake drilling projects contributed significantly to a better understanding of short‐term and long‐term climate change and natural hazards.
Space Station Operations Would Extend Until at Least 2024 Under Obama Plan
Authors: Showstack Randy
Published: January 2014

An 8 January decision by the White House to propose an extension of the International Space Station's (ISS) operation until at least 2024 would allow for increased research on board the floating laboratory, a longer planning horizon for commercial activities, and a continuation of international cooperation in space, administration officials said. The proposal, which has received initial support from some key members of Congress, would be the second extension for ISS under the Obama administration and would accommodate increased research related to long‐duration human space flight, Earth science, and other areas. ISS, which in the United States is authorized under the NASA Authorization Act of 2010, was last extended in 2010 and costs about $3 billion annually to operate.
Kīlauea magma chamber inflation triggered strong 2007 earthquakes
Authors: Schultz Colin
Published: January 2014

Hawaii's Kīlauea volcano has been erupting since 1983. Starting in 2003, researchers noticed an inflation of the magma chamber beneath the volcano; this inflation accelerated in 2006. In June 2007, the volcano's eruption peaked with a burst of activity known as the Father's Day event. In the buildup to those eruptions, according to new research by Wauthier et al., a pair of large‐magnitude earthquakes hit, with an epicenter beneath the volcano. Earthquakes are common around the volcano, which sits on Hawaii's Big Island, but with magnitudes of 4.7 and 4.1, the two 2007 earthquakes were among the most powerful recorded in the region since records began in 1959.
Plasma loss mechanisms from Saturn's magnetosphere
Authors: Schultz Colin
Published: January 2014

Since the first up‐close observations of Saturn, made by the Pioneer 11 probe in 1979, a great deal has been learned about the dynamics of the gas giant's magnetosphere. In‐depth observations made by the Cassini orbiter, which has been circling Saturn since 2004, have revealed fundamental differences between the behavior of Saturn's magnetosphere and that of the Earth's magnetosphere. Earth's magnetospheric plasma is largely populated by ions captured from the solar wind, whereas Saturn's plasma comes predominantly from water vapor that spews from massive geysers on the southern end of its icy moon Enceladus. Ionized water vapor from Enceladus streams out at 12 to 250 kilograms per second, yet observations show that the concentration of plasma in Saturn's magnetosphere is at a relatively steady level. This discrepancy has left researchers searching for potential plasma loss mechanisms. In a review, Thomsen highlights the progress made in recent years in understanding this question.
Triboelectric Nanogenerator as an Active UV Photodetector
Authors: Lin Zong‐Hong , Cheng Gang , Yang Ya , Zhou Yu Sheng , Lee Sangmin , Wang Zhong Lin
Published: January 2014

Self‐powered nanosensors and nanosystems have attracted significant attention in the past decades and have gradually become the most desirable and promising prototype for environmental protection/detection because no battery is needed to power the device. Therefore, in this paper a design is proposed for a self‐powered photodetector based on triboelectric nanogenerator (TENG) configuration. 3D dendritic TiO2 nanostructures are synthesized as the built‐in UV photodetector as well as the contact material of the TENG. The cost‐effective, robust, and easily fabricated TENG‐based photodetector presents superior photoresponse characteristics, which include an excellent responsivity over 280 A W−1, rapid rise time (18 ms) and decay time (31 ms), and a wide detection range of light intensity from 20 μW cm−2 to 7 mW cm−2. In the last part of the paper, a stand‐alone and self‐powered environmental sensing device is developed by applying poly(methyl methacrylate) (PMMA) substrates and springs to assemble the TENG‐based photodetector. These results indicate that the new prototype sensing device based on the TENG configuration shows great potential as a self‐powered photodetector.
Defining quality metrics and improving safety and outcome in allergy care
Authors: Lee Stella , Stachler Robert J. , Ferguson Berrylin J.
Published: January 2014

Background

The delivery of allergy immunotherapy in the otolaryngology office is variable and lacks standardization. Quality metrics encompasses the measurement of factors associated with good patient‐centered care. These factors have yet to be defined in the delivery of allergy immunotherapy. We developed and applied quality metrics to 6 allergy practices affiliated with an academic otolaryngic allergy center.

Methods

This work was conducted at a tertiary academic center providing care to over 1500 patients. We evaluated methods and variability between 6 sites. Tracking of errors and anaphylaxis was initiated across all sites. A nationwide survey of academic and private allergists was used to collect data on current practice and use of quality metrics.

Results

The most common types of errors recorded were patient identification errors (n = 4), followed by vial mixing errors (n = 3), and dosing errors (n = 2). There were 7 episodes of anaphylaxis of which 2 were secondary to dosing errors for a rate of 0.01% or 1 in every 10,000 injection visits/year. Site visits showed that 86% of key safety measures were followed. Analysis of nationwide survey responses revealed that quality metrics are still not well defined by either medical or otolaryngic allergy practices. Academic practices were statistically more likely to use quality metrics (p = 0.021) and perform systems reviews and audits in comparison to private practices (p = 0.005).

Conclusion

Quality metrics in allergy delivery can help improve safety and quality care. These metrics need to be further defined by otolaryngic allergists in the changing health care environment.
Supramolekulare Anordnungen mit Charge‐Transfer‐Wechselwirkungen zwischen Donor‐ und Akzeptor‐Chromophoren
Authors: Das Anindita , Ghosh Suhrit
Published: January 2014

In diesem Kurzaufsatz werden supramolekulare Anordnungen diskutiert, bei denen eine (nichtkovalente) Charge‐Transfer(CT)‐Wechselwirkung zwischen einem organischen Donor und Akzeptor genutzt wird, um Strukturen wie fibrilläre Gele, Micellen, Vesikel, Nanoröhren, Foldamere, konformativ eingeschränkte Makromoleküle und flüssigkristalline Phasen zu erzeugen. Nicht zuletzt auch nach dem Vorbild der Natur haben Chemiker die Wasserstoffbrücke als ein Hilfsmittel für die Herstellung von supramolekularen Anordnungen aus einer vielfältigen Auswahl an abiotischen Bausteinen umfassend genutzt. Als Strukturmotiv können CT‐Komplexe hinsichtlich ihrem gerichteten Charakter und ihrer Komplementarität mit Wasserstoffbrücken‐gebundenen Komplexen verglichen werden. Vorteile von CT‐Wechselwirkungen sind eine breite Lösungsmitteltoleranz und ihre einfache spektroskopische Messung. Ein potentieller Nachteil ist jedoch ihre geringe Assoziationskonstante. Um dieses Hindernis zu überwinden, wurden verschiedene Strategien entwickelt, z. B. die Verstärkung von CT‐Wechselwirkungen mit zusätzlichen nichtkovalenten Kräften, ohne dass die Art der Donor‐Akzeptor‐Stapelung beeinträchtigt wird. Ein besonders vielversprechendes Anwendungsfeld von Donor‐Akzeptor‐CT‐Komplexen ist die organische Elektronik.
TMEDA in der Eisen‐katalysierten Kumada‐Kupplung: homoleptische at‐Komplexe statt Diaminaddukte
Authors: Bedford Robin B. , Brenner Peter B. , Carter Emma , Cogswell Paul M. , Haddow Mairi F. , Harvey Jeremy N. , Murphy Damien M. , Nunn Joshua , Woodall Christopher H.
Published: January 2014

Eisenchloride bilden mit Mesityl‐Grignard‐Reagentien und Tetramethylethylendiamin (TMEDA) unter katalyserelevanten Bedingungen nicht den entsprechenden Diaminkomplex, sondern den homoleptischen at‐Komplex [Fe(mes)3]− (mes=Mesityl), der die katalytische Aktivität gewährleistet. Sowohl [Fe(mes)3]− als auch [Fe(Bn)3]− (Bn=Benzyl) reagieren mit repräsentativen Elektrophilen schneller als die entsprechenden neutralen [FeR2(TMEDA)]‐Komplexe. Mit Benzyl‐ oder kleineren Grignard‐Reagentien werden zudem FeI‐Spezies beobachtet. Die Festkörpermolekülstrukturen von [Fe(Bn)3]− und [Fe(Bn)4]− wurden bestimmt. [Fe(Bn)4]− ist der erste strukturell charakterisierte homoleptische Eisen(III)‐σ‐Organylkomplex.
Proximity‐Enabled Protein Crosslinking through Genetically Encoding Haloalkane Unnatural Amino Acids
Authors: Xiang Zheng , Lacey Vanessa K. , Ren Haiyan , Xu Jing , Burban David J. , Jennings Patricia A. , Wang Lei
Published: January 2014

The selective generation of covalent bonds between and within proteins would provide new avenues for studying protein function and engineering proteins with new properties. New covalent bonds were genetically introduced into proteins by enabling an unnatural amino acid (Uaa) to selectively react with a proximal natural residue. This proximity‐enabled bioreactivity was expanded to a series of haloalkane Uaas. Orthogonal tRNA/synthetase pairs were evolved to incorporate these Uaas, which only form a covalent thioether bond with cysteine when positioned in close proximity. By using the Uaa and cysteine, spontaneous covalent bond formation was demonstrated between an affibody and its substrate Z protein, thereby leading to irreversible binding, and within the affibody to increase its thermostability. This strategy of proximity‐enabled protein crosslinking (PEPC) may be generally expanded to target different natural amino acids, thus providing diversity and flexibility in covalent bond formation for protein research and protein engineering.
Induction of Electromotive Force by an Autonomously Moving Magnetic Bot
Authors: Sailapu Sunil Kumar , Chattopadhyay Arun
Published: January 2014

We report the observation of the induction of electromotive force (emf) into a Faraday coil by an autonomously moving composite magnetic particle in aqueous medium. The particle consisted of a micron‐sized polymer sphere, which was decorated with catalytic Pd nanoparticles (NPs) and attached to a micron‐scale (N‐42 grade) rare‐earth magnet. The Pd NPs catalytically decomposed H2O2 to generate O2, resulting in buoyancy‐driven vertical motion of the particle, while the micromagnet induced emf during the flight. Because a small volume of ethanol was layered on top of the liquid, the bubble burst when the particle ascended to the top and thus nearly continuous vertical motion was achieved. Spikes of alternating electrical signal could be observed up to 20 times per minute. The signal was sufficiently strong to illuminate light‐emitting diodes following appropriate amplification. This distinctive approach is expected to pave the way to developing synthetic bots which are autonomously propelled, generating their own signal for running complex circuitry.
Pd/C als Katalysator für die vollständig regioselektive und milde C‐H‐Funktionalisierung von Thiophenen
Authors: Tang Dan‐Tam D. , Collins Karl D. , Ernst Johannes B. , Glorius Frank
Published: January 2014

Die vollständig C3‐selektive Arylierung von Thiophenen und Benzo[b]thiophenen wurde unter Verwendung von Pd/C als Heterogenkatalysator ohne Ligand und Additive unter milden Reaktionsbedingungen erreicht. Die Praktikabilität dieser Transformation beruht auf ihrer bemerkenswerten Toleranz für funktionelle Gruppen und der Unempfindlichkeit gegen H2O und Luft. Die Methode ist ebenso anwendbar auf Benzofuran, 1H‐Indol und 2‐n‐Butylfuran und führt zu den entsprechenden C2‐arylierten Produkten. Drei‐Phasen‐, Hg‐Vergiftungs‐ und Filtrationstests deuten in hohem Maße auf eine heterogene katalytisch aktive Spezies hin.
Divergent Syntheses of Fused β‐Naphthol and Indene Scaffolds by Rhodium‐Catalyzed Direct and Decarbonylative Alkyne–Benzocyclobutenone Couplings
Authors: Chen Peng‐hao , Xu Tao , Dong Guangbin
Published: January 2014

A tunable rhodium‐catalyzed intramolecular alkyne insertion reaction proceeding through the CC cleavage of benzocyclobutenones is described. Selective formation of either the direct or decarbonylative insertion product can be controlled by using different catalytic systems. A variety of fused β‐naphthol and indene scaffolds were obtained in good yields with high functional group tolerance. This work illustrates a divergent approach to synthesize fused‐ring systems by CC activation/functionalization.
Ligand Bite Angle‐Dependent Palladium‐Catalyzed Cyclization of Propargylic Carbonates to 2‐Alkynyl Azacycles or Cyclic Dienamides
Authors: Daniels David S. B. , Jones Alison S. , Thompson Amber L. , Paton Robert S. , Anderson Edward A.
Published: January 2014

The regioselectivity of the palladium‐catalyzed cyclization of propargylic carbonates with sulfonamide nucleophiles is critically dependent on the bite angle of the bidentate phosphine ligand. Ligands with small bite angles favor attack on the central carbon atom of an allenylpalladium intermediate to afford cyclic dienamide products, whereas the use of those with large bite angles leads to alkynyl azacycles, with high stereoselectivity. A computational analysis of the reaction pathway is also presented.
Pd/C as a Catalyst for Completely Regioselective CH Functionalization of Thiophenes under Mild Conditions
Authors: Tang Dan‐Tam D. , Collins Karl D. , Ernst Johannes B. , Glorius Frank
Published: January 2014

The completely C3‐selective arylation of thiophenes and benzo[b]thiophenes was achieved by using Pd/C as a heterogeneous catalyst without ligands or additives under mild reaction conditions. The practicability of this transformation is demonstrated by notable functional group tolerance and the insensitivity of the reaction to H2O and air. This method is also applicable to nitrogen‐ and oxygen‐containing heterocycles, yielding the corresponding C2‐arylated products. Three‐phase tests along with Hg‐poisoning and hot‐filtration tests suggest that the catalytically active species is heterogeneous in nature.
Bandgap Engineering through Controlled Oxidation of Polythiophenes
Authors: Wei Sujun , Xia Jianlong , Dell Emma J. , Jiang Yivan , Song Rui , Lee Hyunbok , Rodenbough Philip , Briseno Alejandro L. , Campos Luis M.
Published: January 2014

The use of Rozen’s reagent (HOF⋅CH3CN) to convert polythiophenes to polymers containing thiophene‐1,1‐dioxide (TDO) is described. The oxidation of polythiophenes can be controlled with this potent, yet orthogonal reagent under mild conditions. The oxidation of poly(3‐alkylthiophenes) proceeds at room temperature in a matter of minutes, introducing up to 60 % TDO moieties in the polymer backbone. The resulting polymers have a markedly low‐lying lowest unoccupied molecular orbital (LUMO), consequently exhibiting a small bandgap. This approach demonstrates that modulating the backbone electronic structure of well‐defined polymers, rather than varying the monomers, is an efficient means of tuning the electronic properties of conjugated polymers.
Synergistic Spin Transition between Spin Crossover and Spin‐Peierls‐like Singlet Formation in the Halogen‐Bonded Molecular Hybrid System: [Fe(Iqsal)2][Ni(dmit)2]⋅CH3CN⋅H2O
Authors: Fukuroi Kappei , Takahashi Kazuyuki , Mochida Tomoyuki , Sakurai Takahiro , Ohta Hitoshi , Yamamoto Takashi , Einaga Yasuaki , Mori Hatsumi
Published: January 2014

To introduce halogen‐bond interactions between a cation and an anion, a novel FeIII complex from iodine‐substituted ligands involving a paramagnetic nickel dithiolene anion was prepared and characterized. The compound exhibited the synergy between a spin‐crossover transition and a spin‐Peierls‐like singlet formation. The halogen‐bond interactions between the iodine and the sulfur atoms stabilized the paramagnetic state of π‐spins and played a crucial role in the synergistic magnetic transition between d‐ and π‐spins. In addition, the compound showed the light‐induced excited spin state trapping effect.
Modeling of gas–liquid separation through stacked neural network
Authors: Qazi Nadeem , Yeung Hoi
Published: January 2014

In recent years, few mechanistic models have been proposed for design optimization and predicting the performance of reserve flow cyclonic separators. However, there is not much literature available on design and performance evaluation of axial flow compact separator. The work presented in this paper demonstrates the use of stacked neural network to model the nonlinear process of gas–liquid separation through a novel designed axial flow compact separator (called as I‐SEP in this study). We trained several standard back propagation training algorithms to predict the separation efficiency of the I‐SEP; these base models are then combined to form a single composite model. Principle component regression techniques are used to estimate the weight of the participant trained neural networks in the composite model. It has shown in this work that combination of trained neural networks improves prediction accuracy of gas–liquid separation as compared with that of participant individual neural network models. The stacked neural network model produced satisfactory prediction on unseen experimental data and may be helpful to the operators in effectively controlling the separator by predicting the separation efficiency at the changing operating inlet condition. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Modeling and CFD‐PBE simulation of an airlift bioreactor for PHB production
Authors: Mavaddat Poorya , Mousavi Seyyed Mohammad , Amini Ershad , Azargoshasb Hamidreza , Shojaosadati Seyed Abbas
Published: January 2014

In the present attempt, a 3D simulation using a commercially available computational fluid dynamics package (FLUENT 6.3.26), and a metabolic model were used to investigate hydrodynamics and production of polyhydroxybutyrate (PHB) in an airlift bioreactor, performed by Tavares et al. (L. Z. Tavares, E. S. da Silva, J. G. C. Pradella. Biochem. Eng. J., 2004; 18, 21–31). An Eulerian approach was applied to model the gas–liquid interactions. In order to account for the combined effect of bubble breakup and coalescence in the bioreactor, a population balance model implemented in the software was used. Biosynthesis of PHB in the bioreactor was examined and maximum forward reaction rate values of thiolase, reductase, and synthase steps were determined as V1(thiolase) = 1.8 mM/min, V1(reductase) = 400 mM/min, and V1(synthase) = 380 mM/min to predict the experimental PHB production rate by Tavares et al. suitably. A simplified reaction was considered for PHB production. Moreover, gas holdup, liquid velocity vectors, shear stress, and volumetric oxygen transfer coefficient were investigated. Also, molar concentration profiles of PHB and glucose within the bioreactor were obtained. © 2014 Curtin University of Technology and John Wiley & Sons, Ltd.
Molecular, rheological, and thermal study of long‐chain branched polypropylene obtained by esterification of anhydride grafted polypropylene
Authors: Guapacha Jorge , Failla Marcelo D. , Vallés Enrique M. , Quinzani Lidia M.
Published: January 2014

Long‐chain branched polypropylene was prepared using reaction in the molten state in the presence of glycerol and a linear polypropylene functionalized with maleic anhydride (PPg). The concentration of glycerol in the melt was varied in the range from 0.1 to 5 wt % to obtain different levels of branching. FTIR spectroscopy results indicate that the OH groups of glycerol react with the anhydrides on the PPg chains giving place to ester groups. The presence of long‐chain branches in the molecular structure of PPg was confirmed using multiple‐detection size‐exclusion chromatography and rheology. These techniques demonstrate that the level of branching increases with glycerol concentration and that the modification of PPg produces materials with a bimodal distribution of polymer species. Moreover, some of the highly modified materials display gel‐like behavior. The materials also display thermo‐rheological complexity and enhanced activation energy at low frequencies. The crystallization study shows that both the anhydride groups in PPg and the LCBs have opposite nucleating effects. PPg presents the largest activation energy of crystallization and its value decreases with the concentration of glycerol for a given level of crystallization. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40357.
Effect of polymer chain scission on photodegradation behavior of polystyrene/multi‐wall carbon nanotube composite
Authors: Hamadate Masato , Sato Ryousaku , Miyazaki Kensuke , Okazaki Noriyasu , Nakatani Hisayuki
Published: January 2014

To clarify an effect of polymer chain scission on a polystyrene (PS)/multi‐wall carbon nanotube (MWNT) composite photodegradation, a relationship between the change of molecular weight and photodegradation behavior was studied. The MWNT loading brought about severe PS chain scission and led to the increase of the low molecular weight (less than 105) fraction. The increase of the fraction was not proportional to the loading amount and showed the minimum at the 2% loading. The strange behavior was due to a rheological effect bringing about a decrease of shear stress in the composite preparation. An unsaturated end group was produced by the chain scission and became the photodegradation initiator leading to auto‐oxidation and crosslink reactions. The MWNT scavenged radical species and worked as an antioxidant. The coexistence of the unsaturated end group and MWNT made the photodegradation behavior complicated. However, the MWNT radical scavenging ability was considerably poor, and the MWNT had little ability to inhibit the photodegradation initiation. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40362.
Isothermal and non‐isothermal crystallization of poly(L‐lactic acid)/poly(butylene terephthalate) blends
Authors: Di Lorenzo Maria Laura , Rubino Paolo , Cocca Mariacristina
Published: January 2014

Isothermal and non‐isothermal crystallization kinetics of poly(l‐lactic acid)/poly(butylene terephthalate) (PLLA/PBT) blends containing PLLA as major component is detailed in this contribution. PLLA and PBT are not miscible, but compatibility of the polymer pair is ensured by interactions between the functional groups of the two polyesters, established upon melt mixing. Crystal polymorphism of the two polyesters is not influenced by blending, as probed by wide‐angle X‐ray analysis. The addition of PLLA does not affect the temperature range of crystallization kinetics of PBT, nor the crystallinity level attained when the blends are cooled from the melt at constant rate. Conversely, PBT favors crystallization of the biodegradable polyester. The addition of PBT results in an anticipated onset of crystallization of PLLA during cooling at a fixed rate, with a sizeable enhancement of the crystal fraction. Isothermal crystallization analysis confirmed the faster crystallization rate of PLLA in the presence of PBT. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40372.