bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling of electrohydrodynamic drying process using response surface methodology
Authors: Dalvand Mohammad Jafar , Mohtasebi Seyed Saeid , Rafiee Shahin
Published: February 2014

Energy consumption index is one of the most important criteria for judging about new, and emerging drying technologies. One of such novel and promising alternative of drying process is called electrohydrodynamic (EHD) drying. In this work, a solar energy was used to maintain required energy of EHD drying process. Moreover, response surface methodology (RSM) was used to build a predictive model in order to investigate the combined effects of independent variables such as applied voltage, field strength, number of discharge electrode (needle), and air velocity on moisture ratio, energy efficiency, and energy consumption as responses of EHD drying process. Three‐levels and four‐factor Box–Behnken design was employed to evaluate the effects of independent variables on system responses. A stepwise approach was followed to build up a model that can map the entire response surface. The interior relationships between parameters were well defined by RSM.
Novel NG2‐CreERT2 knock‐in mice demonstrate heterogeneous differentiation potential of NG2 glia during development
Authors: Huang Wenhui , Zhao Na , Bai Xianshu , Karram Khalad , Trotter Jacqueline , Goebbels Sandra , Scheller Anja , Kirchhoff Frank
Published: February 2014

NG2 (nerve/glia antigen‐2) is a type I transmembrane glycoprotein and also known as chondroitin sulfate proteoglycan 4. In the parenchyma of the central nervous system, NG2‐expressing (NG2+) cells have been identified as a novel type of glia with a strong potential to generate oligodendrocytes (OLs) in the developing white matter. However, the differentiation potential of NG2 glia remained controversial, largely attributable to shortcomings of transgenic mouse models used for fate mapping. To minimize these restrictions and to more faithfully mimic the endogenous NG2 expression in vivo, we generated a mouse line in which the open reading frame of the tamoxifen‐inducible form of the Cre DNA recombinase (CreERT2) was inserted into the NG2 locus by homologous recombination. Results from this novel mouse line demonstrate that at different developmental stages of the brain, NG2+ cells either stayed as NG2 glia or differentiated into OLs during the whole life span. Interestingly, when Cre activity was induced at embryonic stages, a significant number of reporter+ astrocytes could be detected in the gray matter after birth. However, in other brain regions, such as olfactory bulb, brain stem, and cerebellum, all of the NG2 glia was restricted to the OL lineage. In addition, tamoxifen‐sensitive and NG2 gene locus‐dependent gene recombination could be detected in a small, but persistent population of cortical NeuN+ neurons starting from the second postnatal week. GLIA 2014;62:896–913
Reconsidering the concept of behavioral mechanisms of drug action
Authors: Pitts Raymond C.
Published: February 2014

A half‐century of research in behavioral pharmacology leaves little doubt that behavior–environment contingencies can determine the behavioral effects of drugs. Unfortunately, a coherent behavior‐analytic framework within which to characterize the myriad ways in which contingencies interact with drugs, and to predict effects of a given drug under a given set of conditions, still has not developed. Some behavioral pharmacologists have suggested the concept of behavioral mechanisms of drug action as a foundation for such a framework. The notion of behavioral mechanisms, however, does not seem to have been fully embraced by behavioral pharmacologists. It is suggested here that one reason for this is that the concept itself has not been sufficiently clarified (i.e., stimulus control over use of the phrase is not sufficiently precise). Furthermore, early behavioral pharmacologists may not have possessed an adequate set of analytic tools to develop a viable framework based upon behavior mechanisms. In the first part of this paper, the notion of behavioral mechanisms of drug action is explored, and the sort of data that might provide evidence of a behavioral mechanism is considered. In the second part, it is suggested that the increased availability of quantitative models in behavior analysis may help provide the tools needed for elucidating behavioral mechanisms of drug action. Some examples of how these models have been, and could be used are provided.
Quiet T1‐weighted imaging using PETRA: Initial clinical evaluation in intracranial tumor patients
Authors: Ida Masahiro , Wakayama Toshiki , Nielsen Matthew L. , Abe Takayuki , Grodzki David M.
Published: February 2014

Purpose

To compare the lesion contrast and signal to noise ratio (SNR) obtained with T1‐weighted pointwise encoding time reduction with radial acquisition (PETRA) to those of Magnetization‐Prepared RApid Gradient‐Echo (MPRAGE) for contrast‐enhanced imaging of primary and metastatic intracranial tumors, and to investigate whether PETRA is able to reduce acoustic noise for improved patient comfort.

Materials and Methods

Fifteen patients with intracranial tumors underwent 3 Tesla MRI including inversion‐prepared PETRA and MPRAGE. The two sequences had comparable scan times, spatial resolution and spatial coverage. “Tumor conspicuity” was rated qualitatively by two radiologists, while enhancing lesion‐to‐white matter contrast to noise ratio (CNR) and white‐matter SNR were analyzed quantitatively using paired t‐tests. The acoustic noise generated by each sequence was measured.

Results

Qualitative rating of “tumor conspicuity” by two radiologists resulted in nearly identical average scores for the two sequences. Quantitative analyses revealed that (i) there was no significant difference between the mean CNR values of the two sequences (P = 0.57), (ii) the mean SNR of PETRA was significantly higher than that of MPRAGE (P < 0.01), and (iii) the mean sound level of PETRA was significantly lower than that of MPRAGE (P < 0.01).

Conclusion

Inversion‐prepared PETRA was found to be viable as a quiet alternative to MPRAGE for contrast‐enhanced T1‐weighted studies of intracranial tumors. J. Magn. Reson. Imaging 2015;41:447–453.© 2013 Wiley Periodicals, Inc.
Evaluation of radiation dose to cardiac and pulmonary tissue among patients with stage IV Wilms tumor and pulmonary metastases
Authors: Farooqi Ahsan , Siddiqi Arsalan , Khan Mohammad K. , Esiashvili Natia
Published: February 2014

Background

Most patients with stage IV Wilms tumor (WT) and pulmonary metastases are treated with surgery, local radiotherapy (RT), and whole‐lung irradiation (WLI). The Children's Oncology Group is studying whether WLI should only be given if metastatic lung lesions persist following induction chemotherapy. We hypothesized that radiation dose to cardiac and pulmonary organs are increased when WLI and abdominal RT fields are administered sequentially.

Procedure

We retrospectively identified 16 patients with stage IV WT and pulmonary metastases to model dosimetry plans for concurrent and sequential flank or whole abdomen and whole‐lung fields.

Results

Treatment plans were evaluated for dosimetric endpoints to the heart and the lungs.

The mean dose (Gy) was significantly higher to the heart (15.8 vs. 12.1, P < 0.0001) and lungs (14.1 vs. 12.2, P < 0.0002) when patients with stage IV WT and pulmonary metastases were treated with sequential RT. The percent tissue organ volumes (V) receiving high RT doses of 15 and 20 Gy (V15 and V20) were negligible in concurrent treatment plans. Comparatively, mean V15 and V20 values for sequential treatment plans were 35% and 27%, respectively, for the heart, and 15% and 12%, for the lungs.

Conclusions

The dose to the heart and lung tissue is significantly increased when WLI and abdominal RT fields are administered sequentially. While omission of WLI may be beneficial for patients achieving good response to induction chemotherapy, the less favorable response group may be subjected to increased risk of cardiac and pulmonary toxicities from sequential WLI. Pediatr Blood Cancer 2014; 61:1394–1397. © 2014 Wiley Periodicals, Inc.
Induction of labor compared to dilation and evacuation for postmortem analysis
Authors: Lal A. K. , Kominiarek M. A. , Sprawka N. M.
Published: February 2014

Objective

This study aimed to evaluate the ability to obtain autopsy and cytogenetics after midtrimester termination.

Methods

A retrospective cohort study of women undergoing termination, via induction or dilation and evacuation (D&E), at 16 0/7–23 6/7 weeks was performed. Exclusion criteria were elective termination, preterm labor, PPROM, and no autopsy or cytogenetic exam performed. The ability to obtain cytogenetics and autopsy as well as complications rates were compared between the two groups with Chi‐square tests.

Results

Of the 469 women who met the inclusion criteria, 158 had an induction and 312 had a D&E. The induction of labor group had higher mean gestational ages, p < 0.01. Successful autopsy was more likely in the induction group, 94.3%, versus D&E group, 34.7%, p = 0.01. There was no difference in ability to obtain cytogenetics between the two groups, 89.1% in the induction group, and 92.3% in D&E group, p = 0.4. There was a difference in the total complication rates between the groups, 9.8% (26) in the induction versus 6.4% (20) in the D&E group, p < 0.01; however, there was no difference in major complications.

Conclusions

Midtrimester terminations by induction were more likely to have successful autopsies when compared with D&E. The ability to obtain cytogenetics was similar regardless of termination mode. © 2014 John Wiley & Sons, Ltd.
Concise Review: The Surface Markers and Identity of Human Mesenchymal Stem Cells
Authors: Lv Feng-Juan , Tuan Rocky S. , Cheung Kenneth M.C. , Leung Victor Y.L.
Published: February 2014

The concept of mesenchymal stem cells (MSCs) is becoming increasingly obscure due to the recent findings of heterogeneous populations with different levels of stemness within MSCs isolated by traditional plastic adherence. MSCs were originally identified in bone marrow and later detected in many other tissues. Currently, no cloning based on single surface marker is capable of isolating cells that satisfy the minimal criteria of MSCs from various tissue environments. Markers that associate with the stemness of MSCs await to be elucidated. A number of candidate MSC surface markers or markers possibly related to their stemness have been brought forward so far, including Stro-1, SSEA-4, CD271, and CD146, yet there is a large difference in their expression in various sources of MSCs. The exact identity of MSCs in vivo is not yet clear, although reports have suggested they may have a fibroblastic or pericytic origin. In this review, we revisit the reported expression of surface molecules in MSCs from various sources, aiming to assess their potential as MSC markers and define the critical panel for future investigation. We also discuss the relationship of MSCs to fibroblasts and pericytes in an attempt to shed light on their identity in vivo. Stem Cells  2014;32:1408–1419
Hypoxia Enhances the Radioresistance of Mouse Mesenchymal Stromal Cells
Authors: Sugrue Tara , Lowndes Noel F. , Ceredig Rhodri
Published: February 2014

Mesenchymal stromal cells (MSCs) are radioresistant bone marrow progenitors that support hematopoiesis and its reconstitution following total body irradiation. MSCs reside in hypoxic niches within the bone marrow and tumor microenvironments. The DNA damage response (DDR) represents a network of signaling pathways that enable cells to activate biological responses to DNA damaging agents. Hypoxia-mediated alterations in the DDR contribute to the increased radioresistance of hypoxic cancer cells, limiting therapeutic efficacy. The DDR is important in mediating mouse MSC radioresistance. However, the effects of hypoxia on MSC radioresistance are currently unknown. In this report, hypoxia was found to (a) increase MSC proliferation rate and colony size; (b) increase long-term survival post-irradiation (IR), and (c) improve MSC recovery from IR-induced cell cycle arrest. DNA double-strand break (DSB) repair in MSCs was upregulated in hypoxia, accelerating the resolution of highly genotoxic IR-induced DNA DSBs. In addition, HIF-1α was found to contribute to this enhanced DSB repair by regulating (a) the expression of DNA ligase IV and DNA-PKcs and (b) Rad51 foci formation in response to DNA DSBs in hypoxic MSCs. We have demonstrated, for the first time, that hypoxia enhances mouse MSC radioresistance in vitro. These findings have important implications for our understanding of MSC functions in supporting allogeneic bone marrow transplantation and in tumorigenesis. Stem Cells  2014;32:2188–2200
GCNF-Dependent Activation of Cyclin D1 Expression via Repression of Mir302a During ESC Differentiation
Authors: Wang Hongran , Wang Xiaohong , Archer Trevor K. , Zwaka Thomas P. , Cooney Austin J.
Published: February 2014

Cyclin D1 plays an important role in the regulation of cellular proliferation and its expression is activated during gastrulation in the mouse; however, it remains unknown how cyclin D1 expression is regulated during early embryonic development. Here, we define the role of germ cell nuclear factor (GCNF) in the activation of cyclin D1 expression during embryonic stem cell (ESC) differentiation as a model of early development. During our study of GCNF knockout (GCNF−/−) ESC, we discovered that loss of GCNF leads to the repression of cyclin D1 activation during ESC differentiation. This was determined to be an indirect effect of deregulation Mir302a, which is a cyclin D1 suppressor via binding to the 3′UTR of cyclin D1 mRNA. Moreover, we showed that Mir302 is a target gene of GCNF that inhibits Mir302 expression by binding to a DR0 element within its promoter. Inhibition of Mir302a using Mir302 inhibitor during differentiation of GCNF−/− ESCs restored cyclin D1 expression. Similarly over-expression of GCNF during differentiation of GCNF−/− ESCs rescued the inhibition of Mir302a expression and the activation of cyclin D1. These results reveal that GCNF plays a key role in regulating activation of cyclin D1 expression via inhibition of Mir302a. Stem Cells  2014;32:1527–1537
Concise Review: The Bone Marrow Niche as a Target of Graft Versus Host Disease
Authors: Bonin Malte , Bornhäuser Martin
Published: February 2014

Graft versus host disease (GvHD) remains a major complication after allogeneic hematopoietic stem cell transplantation and is the main cause of transplant-related mortality. In addition to visceral organ involvement, concomitant myelosuppression has been repeatedly described and the extent of cytopenia has been introduced into GvHD scoring systems. Both hematopoietic cells and cells that form the hematopoietic stem and progenitor cell niche have been identified as targets of GvHD. Although several contributing factors have been previously described, the pathophysiology of GvHD-mediated myelosuppression remains largely unclear and to date, no specific therapeutic interventions have achieved routine clinical application. This review focuses on the bone marrow as a target of GvHD, the factors that contribute to myelosuppression, and the possible therapeutic approaches. Stem Cells  2014;32:1420–1428
Developing a Moderate Sedation Policy: Essential Elements and Evidence‐Based Considerations
Authors: Caperelli‐White Louise , Urman Richard D.
Published: February 2014

Developing an institutional policy for moderate sedation is a multidisciplinary effort that should involve close collaboration among clinicians, administrators, and risk managers. A variety of health care providers administer moderate sedation. Sedation policy should address essential elements, such as clinician training and credentialing, equipment, preprocedure evaluation, periprocedure patient monitoring, postprocedure observation and discharge, pharmaceutical agents, and outcomes assessment. Sedation policy should comply with local, state, and national guidelines and standards. Furthermore, sedation policy should be evidence based to incorporate the latest information about best practices and outcomes. Advances in pharmacology, monitoring, medication delivery systems, and simulation training can help improve quality of care and patient safety in the administration of moderate sedation.
Ensuring Patient Safety and Optimizing Efficiency During Gastrointestinal Endoscopy
Authors: Deas Tom , Sinsel Lisa
Published: February 2014

The volume of outpatient gastrointestinal (GI) endoscopy has grown dramatically in the past three decades, fueled by advancing technologies and evolving payment policies. This magnifies the need to ensure high‐quality, safe, and cost‐effective endoscopic services. In recent years, publicized breaches in standards of care for GI endoscopy have intensified the focus on patient safety. Because of these patient safety concerns and changes in regulatory policies, some ambulatory surgery center surveyors and inspectors have held GI endoscopy suites to the same standards as hospital ORs. The American Society for Gastrointestinal Endoscopy and other endorsing organizations drafted the Guidelines for Safety in the Gastrointestinal Endoscopy Unit, which published in January 2014. These safety guidelines relevant to sedation, infection control, staffing, training, technical equipment, traffic patterns, and personal protective equipment differ from other published guidelines for the outpatient surgical setting.
Expression of human apolipoprotein E4 reduces insulin‐receptor substrate 1 expression and Akt phosphorylation in the ageing liver
Authors: Ong Qi-Rui , Chan Elizabeth S. , Lim Mei-Li , Wong Boon-Seng
Published: February 2014

The diabetic drug rosiglitazone was reported to improve glucose tolerance in insulin‐resistant ApoE3 but not ApoE4 knock‐in mice. We therefore examined whether apolipoprotein E (ApoE) has genotype‐specific effects on liver insulin function. At 12 weeks, no difference in liver insulin signaling was detected between fasting ApoE3 and ApoE4 mice. At 72 weeks however, ApoE4 mice had lower IRS‐1 and PI3K expression, and reduced Akt phosphorylation. This decline was associated with lower insulin and higher glucose in ApoE4 mouse liver. Liver cholesterol was not affected. These results show that ApoE4 expression reduces liver insulin signaling and insulin levels, leading to higher glucose content.
Multi‐level gene expression signatures, but not binary, outperform Ki67 for the long term prognostication of breast cancer patients
Authors: Tobin Nicholas P. , Lindström Linda S. , Carlson Joseph W. , Bjöhle Judith , Bergh Jonas , Wennmalm Kristian
Published: February 2014

Proliferation‐related gene signatures have been proposed to aid breast cancer management by providing reproducible prognostic and predictive information on a patient‐by‐patient basis. It is unclear however, whether a less demanding assessment of cell division rate (as determined in clinical setting by expression of Ki67) can function in place of gene profiling.

We investigated agreement between literature‐, distribution‐based, as well as signature‐derived values for Ki67, relative to the genomic grade index (GGI), 70‐gene signature, p53 signature, recurrence score (RS), and the molecular subtype models of Sorlie, Hu, and Parker in representative sets of 253 and 159 breast cancers with a median follow‐up of 13 and 14.5 years, respectively. The relevance for breast cancer specific survival was also addressed in uni‐ and bivariate Cox models.

Taking both cohorts into account, our broad approach identified ROC optimized Ki67 cutoffs in the range of 8–28%. With optimum signature‐reproducing cutoffs, similarity in classification of individual tumors was higher for binary signatures (72–85%), than multi‐level signatures (67–73%). Consistent with strong agreement, no prognostic superiority was noted for either Ki67 or the binary GGI, 70‐gene and p53 signatures in the Uppsala dataset by bivariate analyses. In contrast, Ki67‐independent prognostic capacity could be demonstrated for RS and molecular subtypes according to Sorlie, Hu and Parker in both datasets.

Our results show that the added prognostic value of binary proliferation‐related gene signatures is limited for Ki67‐assessed breast cancers. More complex, multi‐level descriptions have a greater potential in short‐ and long‐term prognostication for biologically relevant breast cancer subgroups.
Comparison of 2.1–1.6 Ga fault-line alkaline metasomatic rocks and granitoids from regional fault zones on the southern framing of the Siberian craton
Authors: Kushch L.V. , Makrygina V.A.
Published: February 2014

The geologic position, development stages, age, and geochemical features of metasomatic and felsic igneous rocks along the southern edge of the Siberian craton are compared. The comparison shows that all the studied metasomatic rocks are confined to the faults feathering the main suture zone of the craton. From Biryusa zone in the southwest and farther northeast, from Primor’e zone to Davan shear zone and Katugino-Ayan zone in the Aldan area, the metasomatic rocks are of similar composition but show higher mineralization. The process begins with blastocataclasis (barren stage). During the second stage, ore-bearing (Nb, Zr, Hf, and REE) potassic solutions circulate along the blastocataclastic zones. They form metasomatic potassic rocks of the early alkaline stage, expressed in subalkaline granitization. The next (acid) stage is marked by the formation of greisens with Sn, Be, Th, U, and W mineralization. The igneous stage might precede or follow the metasomatism. At the time of ongoing tectonic movements, it produces rapakivi-like granites rich in the same elements. Also, a huge volcanoplutonic belt develops along the craton edge during this time. The geochemical features of its felsic volcanics are close to those of the metasomatic rocks and granites. The age of all these rocks is within 2.1–1.6 Ga.
The rate of sedimentation in Lake Arakhlei (Central Transbaikalia), from radiogeochemical and palynological data
Authors: Ptitsyn A.B. , Chu G. , Dar’in A.V. , Zamana L.V. , Kalugin I.A. , Reshetova S.A.
Published: February 2014

Chemical, radioisotopic, and palynological studies of the bottom sediments of mesotrophic Lake Arakhlei have been carried out for paleoclimatic reconstructions and estimation of the sedimentation rate.
Geophysical observations during the flight of the Chelyabinsk meteoroid
Authors: Seleznev V.S. , Liseikin A.V. , Emanov A.A. , Belinskaya A.Yu.
Published: February 2014

The paper describes the effects of the passage of the Chelyabinsk meteoroid (which exploded on 15 February 2013 over the Chelyabinsk Region), which were established from geophysical data from West Siberian stations. The trajectory and speed of the meteoric body from the start of the glow to the breakup were recorded by surveillance cameras and dashcams. Records from broadband seismic stations were used to determine the exact time of the explosion (03:20:34 UTC) from the arrival times of the surface wave produced by this event. The explosion energy was estimated from the surface-wave amplitudes at ~100 kilotons on the assumption that the wave originated from a point source similar to a high-altitude thermonuclear explosion. A database of records from seismic stations obtained during the meteoroid passage has been compiled.
Spectroscopic Studies on Nitrogen-doped Multi-Walled Carbon Nanotubes Using Monochromated STEM-EELS at Low-Voltage
Authors: Arenal R.
Published: February 2014

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.
In situ Determination and Imaging of Physical Properties of Soft Organic Materials by Analytical Transmission Electron Microscopy
Authors: Matsko Nadejda B. , Schmidt Franz P. , Letofsky-Papst Ilse , Rudenko Artem , Mittal Vikas
Published: February 2014

Analytical transmission electron microscopy (ATEM) offers great flexibility in identification of the structural—chemical organization of soft materials at the level of individual macromolecules. However, the determination of mechanical characteristics such as hardness/elasticity of the amorphous and polycrystalline organic substances by ATEM has been problematic so far. Here, we show that energy filtered TEM (EFTEM) measurements enable direct identification and study of mechanical properties in complex (bio-)polymer systems of relevance for different industrial and (bio-)medical applications. We experimentally demonstrate strong correlations between hardness/elasticity of different polymers (polycaprolactone, polylactid, polyethelene, etc.) and their volume plasmon energy. Thickness and anisotropy effects, which substantially mask the material contrast in EFTEM bulk plasmon images, can be adequately removed by normalizing the latter by carbon elemental map. EFTEM data has been validated using atomic force microscopy phase images, where phase shift related to the hardness and elastic modulus of the materials.
Lost in Fragmentation: The Traditional Knowledge Debate Revisited
Authors: THATHONG Sun
Published: February 2014

Numerous international institutions now seek to address the problems of misappropriation and disappearance of traditional knowledge. The relevant legal frameworks were developed at different times and motivated by diverse policy goals. As new frameworks continue to emerge, an important question arises as to how the unity of international efforts to protect traditional knowledge can be maintained. This paper scrutinizes the fragmentation of international law in this field, how it came about, and what its implications are for traditional knowledge protection. It argues that much of the confusion surrounding traditional knowledge protection today is attributable to the fragmentation of international law in this area. To reverse the adverse effects of fragmentation, all institutions involved must be conscious of, and collectively work towards, a common goal, however loosely defined that goal might be. National governments must also ensure that their negotiating positions are consistent across all relevant fora.
Regulation of human telomerase splicing by RNA:RNA pairing
Authors: Wong Mandy S. , Shay Jerry W. , Wright Woodring E.
Published: February 2014

Telomerase adds telomeric repeats onto chromosome ends and is almost universally upregulated in human cancers. Here we demonstrate that RNA:RNA pairing regulates splicing of the catalytic subunit of human telomerase (TERT). Human alleles contain a variable number of 38 bp repeats within TERT intron 6 (>1 kb from exon–intron junctions). At least nine repeats are required for generating the major non-functional ‘minus beta’ isoform, which skips exons 7 and 8. RNA:RNA pairing between the repeats and the pre-mRNA might bring exons 6 and 9 closer, thereby promoting exon skipping. To demonstrate this, we show that mutations within the repeat that abolish exon skipping are corrected by compensatory mutations in the pre-mRNA. This study thus identifies RNA:RNA pairing by repetitive sequences as a novel form of alternative splicing regulation in a gene crucial for cancer survival and sheds new light on functional roles for short repetitive sequences embedded deep within introns throughout the genome.
Numerical calculations of space charge layer effects in nanocrystalline ceria. Part II: detailed analysis of the space charge layer properties
Authors: Göbel Marcus C. , Gregori Giuliano , Maier Joachim
Published: February 2014

The features of space charge profiles and their dependencies are investigated in detail; arising prospects and limitations for applications are discussed.
High adsorption capacity for dye removal by CuZn hydroxyl double salts
Authors: Zhu Shiyao , Jiao Shihui , Liu Ziwei , Pang Guangsheng , Feng Shouhua
Published: February 2014

The excellent adsorption performance of CuZn hydroxyl double salts results from both the surface adsorption and interlayer ion exchange.
Fabrication of MoS2 nanosheet@TiO2 nanotube hybrid nanostructures for lithium storage
Authors: Xu Xin , Fan Zhaoyang , Ding Shujiang , Yu Demei , Du Yaping
Published: February 2014

MoS2 nanosheet@TiO2 nanotube hybrid nanostructures show enhanced cycling performance and rate capability as anode materials for lithium-ion batteries.
Immobilization of papain on nanoporous silica
Authors: He Jia , Wu Ming , Feng Xizeng , Shao Xueguang , Cai Wensheng
Published: February 2014

Immobilization mode, microscopic structure and adsorption mechanism of papain on nanoporous silica surface.
Highly efficient silver-assisted reduction of graphene oxide dispersions at room temperature: mechanism, and catalytic and electrochemical performance of the resulting hybrids
Authors: Ayán-Varela M. , Fernández-Merino M. J. , Paredes J. I. , Villar-Rodil S. , Fernández-Sánchez C. , Guardia L. , Martínez-Alonso A. , Tascón J. M. D.
Published: February 2014

Silver-assisted, room-temperature reduction of graphene oxide and the catalytic and electrocatalytic performance of the resulting graphene–metal hybrids are investigated.
Revealing the metal-like behavior of iodine: an iodide-catalysed radical oxidative alkenylation
Authors: Tang Shan , Wu Yong , Liao Wenqing , Bai Ruopeng , Liu Chao , Lei Aiwen
Published: February 2014

Catalytic HI elimination similar to the β-hydride elimination of transition metals was realized for the radical alkenylation of sulfonyl hydrazides.
Electrocatalytic oxygen reduction kinetics on Fe-center of nitrogen-doped graphene
Authors: Sun Jing , Fang Ya-Hui , Liu Zhi-Pan
Published: February 2014

OOH dissociation is the key step in electrocatalytic oxygen reduction on Fe–N centers of graphite, as revealed from first principles.
Synthesis of low dispersity star-like polyethylene: a combination of click chemistry and a sol–gel process
Authors: Zhang Yongjie , Li Huayi , Xu Zenan , Bu Wensheng , Liu Chenyang , Dong Jin-Yong , Hu Youliang
Published: February 2014

Low dispersity star-like polyethylene was synthesized via a facile sol–gel process using trimethoxysilane-terminated polyethylene derived from thiol-ene click chemistry.
Covalent molecular imprinting made easy: a case study of mannose imprinted polymer
Authors: Shen Feng , Ren Xueqin
Published: February 2014

Covalent mannose imprinted polymers were synthesized by a one-pot method in aqueous medium.
A new meso–meso directly-linked corrole–porphyrin–corrole hybrid: synthesis and photophysical properties
Authors: Murugavel Muthuchamy , Reddy R. V. Ramana , Sankar Jeyaraman
Published: February 2014

meso–meso linked corrole–porphyrin–corrole: a new member of the meso–meso directly linked porphyrinoids family with improved fluorescence quantum yield and lifetime.
Green energy storage chemistries based on neutral aqueous electrolytes
Authors: Chang Zheng , Yang Yaqiong , Li Minxia , Wang Xiaowei , Wu Yuping
Published: February 2014

Recent progress of energy storage systems based on neutral aqueous electrolytes provides some quite green chemistries with promising applications in electric vehicles and smart grids.
Signal amplified two-dimensional photonic crystal biosensor immobilized with glyco-nanoparticles
Authors: Terada Yuhei , Hashimoto Wakana , Endo Tatsuro , Seto Hirokazu , Murakami Tatsuya , Hisamoto Hideaki , Hoshino Yu , Miura Yoshiko
Published: February 2014

A two-dimensional, glycopolymer-immobilized, photonic crystal (PhC) biosensor was developed for the detection of proteins.
Local charge writing in epitaxial SmNiO3 thin films
Authors: Yan Feng , Schoofs Frank , Shi Jian , Ha Sieu D. , Jaramillo R. , Ramanathan Shriram
Published: February 2014

We have investigated the evolution of work function in epitaxial correlated perovskite SmNiO3 (SNO) thin films spanning the metal–insulator transition (MIT) by Kelvin probe force microscopy (KPFM).
Children's Responses to Telegraphic and Grammatically Complete Prompts to Imitate
Authors: Bredin-Oja Shelley L. , Fey Marc E.
Published: February 2014

Purpose

The purpose of this study was to determine whether children in the early stage of combining words are more likely to respond to imitation prompts that are telegraphic than to prompts that are grammatically complete and whether they produce obligatory grammatical morphemes more reliably in response to grammatically complete imitation prompts than to telegraphic prompts.

Method

Five children between 30 and 51 months of age with language delay participated in a single-case alternating treatment design with 14 sessions split between a grammatical and a telegraphic condition. Alternating orders of the 14 sessions were randomly assigned to each child. Children were given 15 prompts to imitate a semantic relation that was either grammatically complete or telegraphic.

Results

No differences between conditions were found for the number of responses that contained a semantic relation. In contrast, 3 of the 5 children produced significantly more grammatical morphemes when presented with grammatically complete imitation prompts. Two children did not include a function word in either condition.

Conclusion

Providing a telegraphic prompt to imitate does not offer any advantage as an intervention technique. Children are just as likely to respond to a grammatically complete imitation prompt. Further, including function words encourages children who are developmentally ready to imitate them.

Supplemental Material

https://doi.org/10.23641/asha.6170204
Half‐duplex relay systems based on polar codes
Authors: Zhan Qicong , Du Minghui , Wang Yige , Zhou Fasheng
Published: February 2014

A cooperative communication scheme based on polar codes is proposed for time‐division half‐duplex relay systems, where the relay node is either a transmitter or a receiver in different time slots of each transmitting period. To enhance efficiency and reduce latency, the proposed codes utilise the decode‐and‐forward strategy and appropriate construction of polarisation. The authors prove that carefully constructed polar codes can achieve the theoretical capacity in the half‐duplex relay channel, and time‐division and information‐division parameters are also optimised to improve the performance of the relay system. It is demonstrated that the random selection strategy is more effective than the appointed one. Simulation results show that the proposed scheme is useful not only for time‐division half‐duplex relay systems but also for other relay cases.
Joint angles of departure and angles of arrival estimation via a spatial‐temporal scheme in overloaded bistatic multiple‐input multiple‐output radars
Authors: Hsu Cheng‐Han , Liu Hsin‐Chin , Hua Meng‐Chang
Published: February 2014

A signal subspace‐based technique was used to estimate joint angles of departure (AODs) and angles of arrival (AOAs) in an overloaded bistatic multiple‐input multiple‐output (MIMO) radar system. First, a spatial‐temporal scheme is used to expand the degrees of freedom in the array. Thus, the number of target AODs and AOAs that can be estimated is higher than the number of the product of the transmit and receive elements. The steering vectors of AODs and AOAs are then obtained from spatial‐temporal eigenvectors, which contain the spatial and temporal information of received signals. This enables highly accurate AOD and AOA estimates even in an overloaded system. The results of several simulations are given to illustrate the effectiveness of the proposed approach.
Improved metal-insulator-transition characteristics of ultrathin VO2 epitaxial films by optimized surface preparation of rutile TiO2 substrates
Authors: Martens Koen , Aetukuri Nagaphani , Jeong Jaewoo , Samant Mahesh G. , Parkin Stuart S. P.
Published: February 2014

Key to the growth of epitaxial, atomically thin films is the preparation of the substrates on which they are deposited. Here, we report the growth of atomically smooth, ultrathin films of VO2 (001), only ∼2 nm thick, which exhibit pronounced metal-insulator transitions, with a change in resistivity of ∼500 times, at a temperature that is close to that of films five times thicker. These films were prepared by pulsed laser deposition on single crystalline TiO2(001) substrates that were treated by dipping in acetone, HCl and HF in successive order, followed by an anneal at 700–750  °C in flowing oxygen. This pretreatment removes surface contaminants, TiO2 defects, and provides a terraced, atomically smooth surface.
Synchrotron radiation-based Mössbauer spectra of 174Yb measured with internal conversion electrons
Authors: Masuda Ryo , Kobayashi Yasuhiro , Kitao Shinji , Kurokuzu Masayuki , Saito Makina , Yoda Yoshitaka , Mitsui Takaya , Iga Fumitoshi , Seto Makoto
Published: February 2014

A detection system for synchrotron-radiation (SR)-based Mössbauer spectroscopy was developed to enhance the nuclear resonant scattering counting rate and thus increase the available nuclides. In the system, a windowless avalanche photodiode (APD) detector was combined with a vacuum cryostat to detect the internal conversion (IC) electrons and fluorescent X-rays accompanied by nuclear de-excitation. As a feasibility study, the SR-based Mössbauer spectrum using the 76.5 keV level of 174Yb was observed without 174Yb enrichment of the samples. The counting rate was five times higher than that of our previous system, and the spectrum was obtained within 10 h. This result shows that nuclear resonance events can be more efficiently detected by counting IC electrons for nuclides with high IC coefficients. Furthermore, the windowless detection system enables us to place the sample closer to the APD elements and is advantageous for nuclear resonant inelastic scattering measurements. Therefore, this detection system can not only increase the number of nuclides accessible in SR-based Mössbauer spectroscopy but also allows the nuclear resonant inelastic scattering measurements of small single crystals or enzymes with dilute probe nuclides that are difficult to measure with the previous detection system.
Domain wall stability in ferroelectrics with space charges
Authors: Zuo Yinan , Genenko Yuri A. , Klein Andreas , Stein Peter , Xu Baixiang
Published: February 2014

Significant effect of semiconductor properties on domain configurations in ferroelectrics is demonstrated, especially in the case of doped materials. Phase field simulations are performed for ferroelectrics with space charges due to donors and electronic charge carriers. The free charges introduced thereby can act as a source for charge compensation at domain walls with uncompensated polarization bound charges. Results indicate that the equilibrium position of a domain wall with respect to its rotation in a head-to-head or a tail-to-tail domain configuration depends on the charge defect concentration and the Fermi level position.
Development of morphogen gradient: The role of dimension and discreteness
Authors: Teimouri Hamid , Kolomeisky Anatoly B.
Published: February 2014

The fundamental processes of biological development are governed by multiple signaling molecules that create non-uniform concentration profiles known as morphogen gradients. It is widely believed that the establishment of morphogen gradients is a result of complex processes that involve diffusion and degradation of locally produced signaling molecules. We developed a multi-dimensional discrete-state stochastic approach for investigating the corresponding reaction-diffusion models. It provided a full analytical description for stationary profiles and for important dynamic properties such as local accumulation times, variances, and mean first-passage times. The role of discreteness in developing of morphogen gradients is analyzed by comparing with available continuum descriptions. It is found that the continuum models prediction about multiple time scales near the source region in two-dimensional and three-dimensional systems is not supported in our analysis. Using ideas that view the degradation process as an effective potential, the effect of dimensionality on establishment of morphogen gradients is also discussed. In addition, we investigated how these reaction-diffusion processes are modified with changing the size of the source region.
Timing control by redundant inhibitory neuronal circuits
Authors: Tristan I. , Rulkov N. F. , Huerta R. , Rabinovich M.
Published: February 2014

Rhythms and timing control of sequential activity in the brain is fundamental to cognition and behavior. Although experimental and theoretical studies support the understanding that neuronal circuits are intrinsically capable of generating different time intervals, the dynamical origin of the phenomenon of functionally dependent timing control is still unclear. Here, we consider a new mechanism that is related to the multi-neuronal cooperative dynamics in inhibitory brain motifs consisting of a few clusters. It is shown that redundancy and diversity of neurons within each cluster enhances the sensitivity of the timing control with the level of neuronal excitation of the whole network. The generality of the mechanism is shown to work on two different neuronal models: a conductance-based model and a map-based model.
Two distinct carrier localization in green light-emitting diodes with InGaN/GaN multiple quantum wells
Authors: Li Zhi , Kang Junjie , Wei Wang Bo , Li Hongjian , Hsiang Weng Yu , Lee Yueh-Chien , Liu Zhiqiang , Yi Xiaoyan , Chuan Feng Zhe , Wang Guohong
Published: February 2014

The effect of carrier localization in InGaN/GaN multiple quantum wells (MQWs) light-emitting diodes is investigated by photoluminescence (PL) and time-resolved PL (TRPL) measurements. PL results show that two peaks obtained by Gaussian fitting both relate to the emission from localized states. By fitting the TRPL lifetimes at various emission energies, two localization depths corresponding to the In-rich regions and quasi-MQWs regions are obtained. Using a model we proposed, we suggest that compositional fluctuations of In content and variation of well width are responsible for carrier localization in In-rich regions and quasi-MQWs regions, respectively.
Current driven magnetization dynamics of a self-polarised synthetic ferrimagnet
Authors: Jenkins A. S. , Lacoste B. , Geranton G. , Gusakova D. , Dieny B. , Ebels U. , Buda-Prejbeanu L. D.
Published: February 2014

Spin torque driven excitations in spin valves and tunnel junctions are often investigated for a two magnetic layer system for which a polarizer (fixed magnetization) and a free layer can be distinguished. In the search for improved microwave properties and to understand the role of different coupling mechanisms between the magnetic layers, here, the excitation spectrum of an exchange coupled two layer synthetic ferrimagnet (SyF) system is investigated numerically with spin momentum transfer acting on both layers simultaneously. This self-polarised two layer system does not contain an external polarizer, and excitation of coupled modes arises due to the mutual spin transfer torque and the Ruderman-Kittel-Kasuya-Yosida interlayer exchange coupling. The current-field state diagrams of static and dynamic states are reported as a function of the interlayer exchange coupling strength. The numerically determined critical boundaries are well reproduced by an analytical stability analysis. The dynamic steady states reveal an optic-like mode at low magnetic fields, which becomes progressively acoustic-like for increased magnetic fields and currents. The frequency of these modes can be tuned by the film thickness and the strength of the interlayer exchange interaction. The results presented here will provide an important guide for designing spin torque oscillators that exploit the dynamic coupling between layers and, furthermore, they will provide a basis to test analytical models of spin torque driven coupled excitations.
Double wavelength infrared emission by localized surface plasmonic thermal emitter
Authors: Chen Hung-Hsin , Hsiao Hui-Hsin , Chang Hung-Chun , Huang Wei-Lun , Lee Si-Chen
Published: February 2014

A double wavelength infrared emission by plasmonic thermal emitter using stacked Au/SiO2/Au/SiO2/Au structure was investigated. The effective refractive index of sandwiched SiO2 is higher than normal value due to the coupling of surface plasmons at the top and bottom Au/SiO2 interfaces. Two different localized surface plasmon modes were excited with the same metal width, but different SiO2 layer thicknesses in top and bottom Au/SiO2/Au tri-layer structures. The measured dispersion relation diagram and simulation demonstrated that the resonances were localized resonance and the distribution of magnetic field was concentrated at the central SiO2 layer between two Au layers.
Adhesion and degradation of organic and hybrid organic-inorganic light-emitting devices
Authors: Momodu D. Y. , Tong T. , Zebaze Kana M. G. , Chioh A. V. , Soboyejo W. O.
Published: February 2014

This paper presents the results of a combined analytical, computational, and experimental study of adhesion and degradation of Organic Light Emitting Devices (OLEDs). The adhesion between layers that are relevant to OLEDs is studied using an atomic force microscopy technique. The interfacial failure mechanisms associated with blister formation in OLEDs and those due to the addition of TiO2 nanoparticles into the active regions are then elucidated using a combination of fracture mechanics, finite element modeling and experiments. The blisters observed in the models are shown to be consistent with the results from adhesion, interfacial fracture mechanics models, and prior reports of diffusion-assisted phenomena. The implications of the work are then discussed for the design of OLED structures with improved lifetimes and robustness.
Ergodicity reflected in macroscopic and microscopic field-dependent behavior of BNT-based relaxors
Authors: Dittmer Robert , Gobeljic Danka , Jo Wook , Shvartsman Vladimir V. , Lupascu Doru C. , Jones Jacob L. , Rödel Jürgen
Published: February 2014

The effect of heterovalent B-site doping on ergodicity of relaxor ferroelectrics is studied using (1 − y)(0.81Bi1/2Na1/2TiO3-0.19Bi1/2K1/2TiO3)-yBiZn1/2Ti1/2O3 (BNT-BKT-BZT) with y = {0.02;0.03;0.04} as a model system. Both the large- and small-signal parameters are studied as a function of electric field. The crystal structure is assessed by means of neutron diffraction in the initial state and after exposure to a high electric field. In order to measure ferroelastic domain textures, diffraction patterns of the poled samples are collected as a function of sample rotation angle. Piezoresponse force microscopy (PFM) is employed to probe the microstructure for polar regions at a nanoscopic scale. For low electric fields E < 2 kV·mm−1, large- and small-signal constitutive behavior do not change with composition. At high electric fields, however, drastic differences are observed due to a field-induced phase transition into a long-range ordered state. It is hypothesized that increasing BZT content decreases the degree of non-ergodicity; thus, the formation of long-range order is impeded. It is suggested that frozen and dynamic polar nano regions exist to a different degree, depending on the BZT content. This image is supported by PFM measurements. Moreover, PFM measurements suggest that the relaxation mechanism after removal of the bias field is influenced by surface charges.
High-temperature thermoelectric properties of novel layered bismuth-sulfide LaO1−xFxBiS2
Authors: Omachi Atsushi , Kajitani Joe , Hiroi Takafumi , Miura Osuke , Mizuguchi Yoshikazu
Published: February 2014

We have investigated the high-temperature thermoelectric properties of the layered compound LaO1−xFxBiS2. The electrical resistivity of LaOBiS2 showed an anomalous behavior; a metal-semiconductor transition was observed around 270 K. It was found that the value of the electrical resistivity decreased with F substitution. The Seebeck coefficient decreased with increasing F concentration. The highest power factor of 1.9 μW/cm K2 at 480 °C was obtained for LaOBiS2.