bluuebunny/crossref_metadata_2025 huggingface dataset:
Simulation‐based estimation: a case study in oncology (SIMEST) and a case study in portfolio selection (SIMUGRAM)
Authors: Thompson James R.
Published: October 2014

Since the time of Poisson, stochastic processes have been axiomatized in the temporally forward direction. Yet for nearly a century, estimation of parameters and even forecasts have been based on likelihood approaches that start with temporally indexed data and then look backward in time. I shall be using the philosophy of Karl Pearson [Scott DW, Tapia RA, Thompson JR. Karl Pearson was right. Computer Science and Statistics: Tenth Annual Symposium on the Interface; 1978, 179–183] in this article where I create, using a forward model, a large virtual universe of happenings based on the assumption of four parameters characterizing an oncological process based on four Poissonian processes. Bins will be formed in the real time space based on the actual data of real world system of times of discovery of primary and secondary tumors and use bin boundaries that enclose roughly 5% of the actual tumor discover data and compare the bin proportions of virtual data with the proportions of actual data in each of the bins. This will enable us to use Karl Pearson's goodness‐of‐fit criterion as the objective function for a Nelder–Mead optimization. We present here an oncological example where the objective is to estimate four parameters relevant to the progression of beast cancer. This procedure is termed the SIMEST paradigm.

Then we briefly describe the patented SIMUGRAM for estimating the distribution of portfolio values using daily resampling strategies. This procedure makes minimal model assumptions and is completely based on data. WIREs Comput Stat 2014, 6:379–385. doi: 10.1002/wics.1320

This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Modeling Methods
Lung involvement in children with lysinuric protein intolerance
Authors: Valimahamed‐Mitha Sarah , Berteloot Laureline , Ducoin Héloise , Ottolenghi Chris , de Lonlay Pascale , de Blic Jacques
Published: October 2014

Background and objectives

Lysinuric protein intolerance (LPI) is a rare multisystemic metabolic disease. The objective of the study was to describe presentation and course of lung involvement in a cohort of ten children.

Patients and methods

Retrospective review of patients followed at Necker‐Enfants Malades University Hospital between 1980 and 2012 for a LPI. In patients with lung involvement, clinical data, chest radiographs, pulmonary function tests, bronchoalveolar lavages, and lung biopsies were analyzed. The first and last high‐resolution computed tomography (HRCT) were also reviewed.

Results

Lung involvement was observed in ten of 14 patients (71 %). Five patients had an acute onset of respiratory symptoms, three had a progressive onset and two were free of symptoms. During the period studied, six patients (60 %) died, all in a context of respiratory failure. Clinical presentation and course were highly variable, even in the same family. HRCT were performed in seven cases, showing in all cases an interstitial pattern and fibrosis in four. All ten patients had pulmonary alveolar proteinosis (PAP) confirmed by histopathological analysis. Five patients had pulmonary fibrosis (at biopsy and/or HRCT scan). Two patients underwent whole lung lavages, without efficiency.

Conclusion

PAP is a constant feature in children with LPI and lung involvement. Pulmonary fibrosis is frequent and these two pathologies may develop independently. This study shows the heterogeneity of presentation and outcome. Lung injury could be secondary to impaired phagocytic function and abnormal inflammatory and immune responses intrinsic to the SLC7A7 mutant phenotype. HRCT is recommended to detect lung involvement.
Comment on “The Effect of Same-Sex Marriage Laws on Different-Sex Marriage: Evidence From the Netherlands”
Authors: Dinno Alexis
Published: October 2014

In the recent Demography article titled “The Effect of Same-Sex Marriage Laws on Different-Sex Marriage: Evidence From the Netherlands,” Trandafir attempted to answer the question, Are rates of opposite sex marriage affected by legal recognition of same-sex marriages? The results of his approach to statistical inference—looking for evidence of a difference in rates of opposite-sex marriage—provide an absence of evidence of such effects. However, the validity of his conclusion of no causal relationship between same-sex marriage laws and rates of opposite-sex marriage is threatened by the fact that Trandafir did not also look for equivalence in rates of opposite-sex marriage in order to provide evidence of an absence of such an effect. Equivalence tests in combination with difference tests are introduced and presented in this article as a more valid inferential approach to the substantive question Trandafir attempted to answer.
Educating the clinical trainer: professional gain for the trainee? A controlled intervention study in general practice
Authors: Jochemsen-van der Leeuw H. G. A. Ria , Van Dijk Nynke , Wieringa-de Waard Margreet , De Jong Wilfried
Published: October 2014

The aim of this study was to establish whether a ‘teach-the-trainer’ course leads to improvements in, firstly, the knowledge and attitude of clinical trainers and their trainees, and, secondly, the role model behaviour of the clinical trainers. A controlled intervention study was performed with GP trainers and GP trainees from four training institutes in the Netherlands. Clinical trainers in the two intervention institutes received two 3-h training sessions on weight management, focusing on knowledge and attitudes towards obesity, and on conveying the correct professional competency as a positive role model for trainees. This was measured using questionnaires on knowledge, attitude, and role model behaviour (the role model apperception tool; RoMAT). GP trainers showed an increase in knowledge and several characteristics could be identified as being related to positive role model behaviour. A small correlation was found between the trainer’s score on the RoMAT and the attitude of the trainee. A teach-the-trainer course in which knowledge, attitudes, and role modelling are integrated proved to be a first step toward improving the knowledge of clinical trainers, but did not result in a measurably better professional outcome for the trainee, maybe due to a more objective level of assessment.
Acetylcholinesterase (AChE) inhibition aggravates fasting‐induced triglyceride accumulation in the mouse liver
Authors: Yokota Shin-Ichi , Nakamura Kaai , Ando Midori , Kamei Hiroyasu , Hakuno Fumihiko , Takahashi Shin-Ichiro , Shibata Shigenobu
Published: October 2014

Although fasting induces hepatic triglyceride (TG) accumulation in both rodents and humans, little is known about the underlying mechanism. Because parasympathetic nervous system activity tends to attenuate the secretion of very‐low‐density‐lipoprotein‐triglyceride (VLDL‐TG) and increase TG stores in the liver, and serum cholinesterase activity is elevated in fatty liver disease, the inhibition of the parasympathetic neurotransmitter acetylcholinesterase (AChE) may have some influence on hepatic lipid metabolism. To assess the influence of AChE inhibition on lipid metabolism, the effect of physostigmine, an AChE inhibitor, on fasting‐induced increase in liver TG was investigated in mice. In comparison with ad libitum‐fed mice, 30 h fasting increased liver TG accumulation accompanied by a downregulation of sterol regulatory element‐binding protein 1 (SREBP‐1) and liver‐fatty acid binding‐protein (L‐FABP). Physostigmine promoted the 30 h fasting‐induced increase in liver TG levels in a dose‐dependent manner, accompanied by a significant fall in plasma insulin levels, without a fall in plasma TG. Furthermore, physostigmine significantly attenuated the fasting‐induced decrease of both mRNA and protein levels of SREBP‐1 and L‐FABP, and increased IRS‐2 protein levels in the liver. The muscarinic receptor antagonist atropine blocked these effects of physostigmine on liver TG, serum insulin, and hepatic protein levels of SREBP‐1 and L‐FABP. These results demonstrate that AChE inhibition facilitated fasting‐induced TG accumulation with up regulation of the hepatic L‐FABP and SREBP‐1 in mice, at least in part via the activation of muscarinic acetylcholine receptors. Our studies highlight the crucial role of parasympathetic regulation in fasting‐induced TG accumulation, and may be an important source of information on the mechanism of hepatic disorders of lipid metabolism.
Crystal structure of peptidyl‐tRNA hydrolase from a Gram‐positive bacterium, Streptococcus pyogenes at 2.19 Å resolution shows the closed structure of the substrate‐binding cleft
Authors: Singh Avinash , Gautam Lovely , Sinha Mau , Bhushan Asha , Kaur Punit , Sharma Sujata , Singh T.P.
Published: October 2014

Peptidyl‐tRNA hydrolase (Pth) catalyses the release of tRNA and peptide components from peptidyl‐tRNA molecules. Pth from a Gram‐positive bacterium Streptococcus pyogenes (SpPth) was cloned, expressed, purified and crystallised. Three‐dimensional structure of SpPth was determined by X‐ray crystallography at 2.19 Å resolution. Structure determination showed that the asymmetric unit of the unit cell contained two crystallographically independent molecules, designated A and B. The superimposition of Cα traces of molecules A and B showed an r.m.s. shift of 0.4 Å, indicating that the structures of two crystallographically independent molecules were identical. The polypeptide chain of SpPth adopted an overall α/β conformation. The substrate‐binding cleft in SpPth is formed with three loops: the gate loop, Ile91–Leu102; the base loop, Gly108–Gly115; and the lid loop, Gly136–Gly150. Unlike in the structures of Pth from Gram‐negative bacteria, the entry to the cleft in the structure of SpPth appeared to be virtually closed. However, the conformations of the active site residues were found to be similar.
Incidence and distribution of cancers in adolescents and young adults
Authors: Kourie Hampig Raphael , Ghorra Claude , Abadjian Gerard , Germanos Myrna , Antoun Joelle , Ghosn Marwan
Published: October 2014

Background and objectives:

Cancers of adolescents and young adults are relatively rare and have specific features that range from the types and locations of these tumors to their specific medical, physical, psychological and social needs.

Materials and methods:

A retrospective descriptive study on cancer patients aged between 15 and 25 years at Hotel Dieu de France, Saint Joseph University Hospital in Beirut, Lebanon from 2007 to 2011 was conducted to study the incidence and distribution of cancers.

Results:

We identified 205 adolescents and young adults with cancer in Hôtel Dieu de France, Saint Joseph University Hospital in Beirut, from 2007 to 2011, which represent 2.9% of all can-cers diagnosed in this hospital. Lymphomas (32%), bone tumors (12%), central nervous system (CNS) tumors (13%), leukemia (9%), thyroid cancers (9%), ovarian (5%) and testicular tumors (3%) accounted for more than 80% of all cancers. Thyroid cancers represented 17% of all female cancers in this patient category compared to 1% in males, while the CNS and bone cancer had a higher incidence in males.

Conclusions:

Despite the low incidence of cancers in adolescents and young adults, it is essen-tial to obtain more multicentric national and regional comparative data, which can help to elucidate the incidence and distribution of these cancers.
Building brains, forging futures
Authors: Rushton Francis E. , Kraft Colleen
Published: October 2014

Recent leaps in the understanding of early brain growth and child development pro-vide us with scientific underpinnings for strategies to improve child health outcomes. Genetic, environmental, and behavioral factors impact the growing child and have a profound impact on lifelong health and function. Recent advances in knowledge concerning the biologic underpin-nings of brain development provide a better understanding upon which to base interventions. All growing children experience stress. However, if children are stressed in a manner that ex-ceeds their coping capability, the stress is considered toxic. Toxic stress can impede the cogni-tive and social emotional growth of the developing brain. Pediatricians have the opportunity to intervene through screening for families at risk, supporting optimal parenting, and linking in a team fashion with other providers of care for young children to support development.
The application of Lean Six Sigma to provide high-quality, reliable pediatric care
Authors: Lighter Donald E.
Published: October 2014

Physicians and health administrators face an increasingly competitive practice environment that challenges financial survival. Only through increasing clinical quality and administrative efficiency will practitioners be able to navigate the changes in health care that are sweeping the industry. This paper describes an approach that can prove crucial to improving patient care, reducing costs, and ensuring sustainability.
β-Casein(94-123)-derived peptides differently modulate production of mucins in intestinal goblet cells
Authors: Plaisancié Pascale , Boutrou Rachel , Estienne Monique , Henry Gwénaële , Jardin Julien , Paquet Armelle , Léonil Joëlle
Published: October 2014

We recently reported the identification of a peptide from yoghurts with promising potential for intestinal health: the sequence (94-123) of bovine β-casein. This peptide, composed of 30 amino acid residues, maintains intestinal homoeostasis through production of the secreted mucin MUC2 and of the transmembrane-associated mucin MUC4. Our study aimed to search for the minimal sequence responsible for the biological activity of β-CN(94-123) by using several strategies based on (i) known bioactive peptides encrypted in β-CN(94-123), (ii) in silico prediction of peptides reactivity and (iii) digestion of β-CN(94-123) by enzymes of intestinal brush border membranes. The revealed sequences were tested in vitro on human intestinal mucus-producing HT29-MTX cells. We demonstrated that β-CN(108-113) (an ACE-inhibitory peptide) and β-CN(114-119) (an opioid peptide named neocasomorphin-6) up-regulated MUC4 expression whereas levels of the secreted mucins MUC2 and MUC5AC remained unchanged. The digestion of β-CN(94-123) by intestinal enzymes showed that the peptides β-CN(94-108) and β-CN(117-123) were present throughout 1·5 to 3 h of digestion, respectively. These two peptides raised MUC5AC expression while β-CN(117-123) also induced a decrease in the level of MUC2 mRNA and protein. In addition, this inhibitory effect was reproduced in airway epithelial cells. In conclusion, β-CN(94-123) is a multifunctional molecule but only the sequence of 30 amino acids has a stimulating effect on the production of MUC2, a crucial factor of intestinal protection.
A ‘Remote’ Town in the Indian Himalaya
Authors: MATHUR NAYANIKA
Published: October 2014

This article studies the impact of the creation of a new state in northern India through an analysis of space. The space under consideration is the town of Gopeshwar, which serves as the administrative headquarters of a district in the state of Uttarakhand. Uttarakhand was created as a distinct Himalayan state in 2000 after a prolonged period of mass agitation to this end. The movement for statehood had emphasized historical neglect coupled with exploitation of the mountains of Uttarakhand by the plains. Beginning with an analysis of the town plan, this article moves on to describe how this place is made into a space by everyday practices. In particular it concentrates on the narratives of agents of the state who express a longing to escape this ‘remote’ town. Through an interrogation of the trope of remoteness, this article argues that the creation of the new state has served, ironically enough, to accentuate the traditional characterization of the Himalaya as a backward, inferior space within India.
Neural effects of cognitive–behavioural therapy on dysfunctional attitudes in depression
Authors: Sankar A. , Scott J. , Paszkiewicz A. , Giampietro V. P. , Steiner H. , Fu C. H. Y.
Published: October 2014

Background

Dysfunctional attitudes are a feature of depression that has been correlated with receptor binding abnormalities in limbic and cortical regions. We sought to investigate the functional neuroanatomy of dysfunctional attitudes in major depressive disorder (MDD) and the effects of treatment with cognitive–behavioural therapy (CBT).

Method

Participants were 16 patients with unipolar depression in an acute depressive episode (mean age 40.0 years) and 16 matched healthy controls (mean age 39.9 years). Patients were medication free and received a course of treatment with CBT. All participants underwent functional magnetic resonance imaging (fMRI) scans at baseline and at week 16, prior to the initiation of therapy and following the course of CBT for patients. During each fMRI scan, participants indicated their attributions to statements from a modified Dysfunctional Attitudes Scale (mDAS-48).

Results

MDD patients in an acute depressive episode endorsed a greater number of extreme responses to DAS statements, which normalized following CBT treatment. Extreme attributions were associated with greater activation in the left hippocampal region, inferior parietal lobe and precuneus in MDD patients as compared with healthy controls as a main effect of group. An interaction effect was found in the left parahippocampal region, which showed less attenuation in MDD patients at the follow-up scan relative to healthy controls.

Conclusions

Attenuation of activity in the parahippocampal region may be indicative of an improvement in dysfunctional thinking following CBT treatment in depression, while persistent engagement of regions involved in attentional processing and memory retrieval with extreme attributions reflects a trait feature of depression.
Unterschiede in der Qualität des Körper- und Blickkontakts bei Säuglingen mit und ohne Regulationsstörung
Authors: Streit Uta , Nantke Sabine , Jansen Fritz
Published: October 2014

Fragestellung: Wie eine Vielzahl von Studien belegen, ist Körperkontakt entscheidend für Gesundheit, Regulation und Entwicklung des Säuglings sowie die Eltern-Kind-Interaktion. Daher wäre gerade für Säuglinge mit Regulationsstörungen (wie exzessivem Schreien, Schlaf- und Fütterproblemen) ein qualitativ hochwertiger Körperkontakt wünschenswert. Vorausgegangene Beobachtungen im Rahmen der Elternberatung deuteten darauf hin, dass gerade diese Säuglinge eher einen schlechten Körper- und Blickkontakt aufweisen. Dies war der Ausgangspunkt der vorliegenden Studie, in der Säuglinge mit und ohne Regulationsstörung bezüglich ihres Körper- und Blickkontakts miteinander verglichen wurden. Methodik: Die Qualität des Körper- und die Dauer des Blickkontakts wurden anhand von Videoaufzeichnungen der Mutter-Kind-Interaktion mittels Rating ausgewertet. Zusätzlich wurde die tägliche Dauer von Schreien, Schlafen, Füttern, Unruhe und ruhiger Beschäftigung mit Hilfe eines Tagebuchs erfasst. Ergebnisse: Säuglinge mit einer Regulationsstörung zeigten einen schlechteren Körperkontakt (p < .01) und weniger Blickkontakt (p < .01). In nahezu allen Tagebuchvariablen zeigten sich signifikante Gruppenunterschiede. Schlussfolgerungen: Offensichtlich können Körper- und Blickkontakt, grundlegende kommunikative Fähigkeiten, bei Säuglingen mit Regulationsstörungen blockiert sein. Dies kann sich ungünstig auf die Regulationsproblematik auswirken. Therapeutische Maßnahmen mit betroffenen Kindern und ihren Eltern sollten daher auch auf eine Verbesserung der Fähigkeit zu Körper- und Blickkontakt abzielen.
Nicht-suizidales selbstverletzendes Verhalten (NSSV) und Suizidale Verhaltensstörung (SVS) im DSM-5
Authors: Plener Paul L. , Kapusta Nestor D. , Brunner Romuald , Kaess Michael
Published: October 2014

Nicht-suizidales selbstverletzendes Verhalten (NSSV) und die Suizidale Verhaltensstörung (SVS) wurden in der 5. Auflage des «Diagnostic and Statistical Manual» (DSM-5) der amerikanischen psychiatrischen Gesellschaft (APA) in der «Sektion 3» erstmals als diagnostische Kategorien aufgenommen. Damit werden diese beiden Störungsbilder zwar nicht als formale Diagnosen im neuen Klassifikationssystem anerkannt, jedoch erstmals eindeutig im Rahmen eines Klassifikationssystems definiert. Dies soll weitere Forschungsarbeiten in diesem Bereich in Zukunft vereinheitlichen und erleichtern. Die vorliegende Arbeit stellt diese beiden neuen Störungsbilder vor und bietet anhand eines selektiven Literaturreviews einen Überblick über die Diskussion über NSSV und SVS als eigenständige Störungsbilder. Erste vorliegende Arbeiten, die auf diese Definitionen zurückgreifen, werden vorgestellt. In Deutschland dürfte die Ein-Jahres Prävalenz von NSSV im Jugendalter ca. 4 % betragen, für SVS ca. 9 %. Es kann davon ausgegangen werden, dass die neuen Definitionen zur besseren Vergleichbarkeit von künftigen Studienergebnissen führen werden.
Satellite telemetry and social modeling offer new insights into the origin of primate multilevel societies
Authors: Qi Xiao-Guang , Garber Paul A. , Ji Weihong , Huang Zhi-Pang , Huang Kang , Zhang Peng , Guo Song-Tao , Wang Xiao-Wei , He Gang , Zhang Pei , Li Bao-Guo
Published: October 2014

Multilevel societies (MLS), in which polygynous reproductive units are nested in a larger social matrix, represent a highly complex social system documented only in a small number of mammalian species. Using long-term behavioural data, satellite telemetry and social network analysis, we present a new framework for understanding the function and social dynamics of the golden snub-nosed monkey MLS. Here we show that several one-male units form a cohesive breeding band that associates with one or more all-male units to form a herd. Herds seasonally aggregate and exchange members, thus facilitating gene flow and inbreeding avoidance. This MLS evolved from the aggregation of independent one-male, multifemale units that characterize ancestral Asian colobines; the evolutionary pathway leading to this MLS contrasts with that proposed for African papionins, which appear to have undergone internal fissioning of multimale–multifemale groups. The results suggest that both environmental and phylogenetic factors are important in the evolution of a primate MLS.
Quick re-introduction of selective scalar interactions in a pure-shift NMR spectrum
Authors: Lokesh N. , Chaudhari Sachin Rama , Suryaprakash N.
Published: October 2014

A new 1D NMR experiment cited as ‘Quick G-SERF’, which re-introduces selective proton–proton scalar interactions in a pure shift spectrum during real time data acquisition, is reported.
Proton-controlled formation and interconversion of AuI2NiII trinuclear and AuI4NiII3 heptanuclear complexes with mixed thiomalate and bis(diphenylphosphino)ethane
Authors: Igawa Kosuke , Yoshinari Nobuto , Konno Takumi
Published: October 2014

A unique coordination system with linear AuI and octahedral NiII centers, in which two polynuclear structures with different nuclearities are independently formed and inter-converted in response to solution acidities, is reported.
Supramolecular copolymers obtained from two-component gels: metal ion-mediated cross-linking, enhanced viscoelasticity and supramolecular yarns
Authors: Wang Ling , Liu Yaqing , Shen Zhaocun , Wang Tianyu , Liu Minghua
Published: October 2014

Bolaamphiphilic l-histidine and 2,2′-bipyridine-dicarboxylic acids were assembled into supramolecular polymers, which were further cross-linked by Cu(ii) ions.
Cosensitizers for simultaneous filling up of both absorption valleys of porphyrins: a novel approach for developing efficient panchromatic dye-sensitized solar cells
Authors: Sun Xi , Wang Yueqiang , Li Xin , Ågren Hans , Zhu Weihong , Tian He , Xie Yongshu
Published: October 2014

Cosensitizers were designed for simultaneous filling up of both absorption valleys of porphyrins, achieving a high cosensitized DSSC efficiency of 10.75%.
Aqueous production of oxygen atoms from hydroxyl radicals
Authors: Codorniu-Hernández Edelsys , Hall Kyle Wm. , Ziemianowicz Daniel , Carpendale Sheelagh , Kusalik Peter G.
Published: October 2014

Car–Parrinello MD simulations and advanced visualization techniques of OH*-pair encounters in water demonstrate the formation of the triplet oxygen atom.
Hydrogen-induced high-temperature segregation in palladium silver membranes
Authors: Zeng Gaofeng , Jia Haiyuan , Goldbach Andreas , Zhao Lingfang , Miao Shu , Shi Lei , Sun Chenglin , Xu Hengyong
Published: October 2014

Growth of Ag-depleted crystallites on PdAg membranes reduces H2 permeation rates substantially above 823 K but can be reversed in N2.
Assessment of density-functionals for describing the X−+ CH3ONO2gas-phase reactions with X = F, OH, CH2CN
Authors: Proenza Yaicel G. , de Souza Miguel A. F. , Ventura Elizete , do Monte Silmar A. , Longo Ricardo L.
Published: October 2014

The energetics of the ECO2, SN2@C and SN2@N channels of X−+ CH3ONO2(X = F, OH, CH2CN) gas-phase reactions were computed with several functionals and compared to CCSD(T)/CBS.
Effect of the electropositive elements A = Sc, La, and Ce on the microscopic dynamics of AV2Al20
Authors: Koza Michael Marek , Leithe-Jasper Andreas , Sischka Erik , Schnelle Walter , Borrmann Horst , Mutka Hannu , Grin Yuri
Published: October 2014

Neutron spectroscopy andab initiocalculations indicate the apparent glass-like lattice thermal conductivityκlof the nano-cage compound ScV2Al20as an effect of phonon renormalization predetermined by the crystal’s ground state properties.
Highly active and durable silica-coated Pt cathode catalysts for polymer electrolyte fuel cells: control of micropore structures in silica layers
Authors: Takenaka Sakae , Miyazaki Takahiro , Matsune Hideki , Kishida Masahiro
Published: October 2014

Pt cathode catalysts for PEFCs were covered with silica layers in the presence of NH2–(CH2)8–NH2 that functioned as templates for the formation of micropore in the silica layers, to improve the activity and durability of the catalysts.
Arene-ligated heteroleptic terphenolate complexes of thorium
Authors: McKinven Jamie , Nichol Gary S. , Arnold Polly L.
Published: October 2014

Bulky terphenolate ligands allow the synthesis of rare heteroleptic thorium chloride, and borohydride complexes; in the absence of donor solvents, the terphenolate ligands protect the metal ions through neutral Th–η6-arene interactions in a thorium bis(arene) sandwich motif.
Application of chemical vapor generation systems to deliver constant gas concentrations for in vitro exposure to volatile organic compounds
Authors: Lin Ying-Hsuan , Sexton Kenneth G. , Jaspers Ilona , Li Ya-Ru , Surratt Jason D. , Vizuete William
Published: October 2014

Schematic representation of the system design coupling a constant emission source from a diffusion vial to a gas phase in vitro exposure system (GIVES) for a direct air–liquid interface exposure to volatile organic compounds.
Time resolved in situ X-ray diffraction study of crystallisation processes of large pore nanoporous aluminophosphate materials
Authors: Simmance Kerry , van Beek Wouter , Sankar Gopinathan
Published: October 2014

Time resolved high-resolution X-ray powder diffraction was utilized to obtain detailed changes in the crystal structure parameters during the hydrothermal crystallization process of the nanoporous aluminophosphate AlPO-5 (AFI) structure. This in situ study offered not only the influence of metal ions on the onset of crystallization and estimation of the activation energy of the process, but also allowed us to determine in detail the changes in lattice parameters during this process. More importantly the time-resolved study clearly showed the lattice expansion in the divalent metal ions substituted system right from the on-set of crystallization process, compared to the one without any dopant ions, which suggest that an amorphous or poorly crystalline network is formed prior to crystallization that contains the large divalent ions (compared to Al(iii), the substituting element), which is in agreement with the combined XAS/XRD study reported earlier. A mechanism based on this and the earlier study is suggested.
Olefin epoxidation with hydrogen peroxide using octamolybdate-based self-separating catalysts
Authors: Zhou Ming-Dong , Liu Mei-Ju , Huang Liang-Liang , Zhang Jian , Wang Jing-Yun , Li Xue-Bing , Kühn Fritz E. , Zang Shu-Liang
Published: October 2014

Alkylimidazolium/alkylpyridinium octamolybdates can be used as self-separating catalysts in acetonitrile-mediated olefin epoxidations using hydrogen peroxide as oxidant.
Accurate microfluidic sorting of droplets at 30 kHz
Authors: Sciambi Adam , Abate Adam R.
Published: October 2014

By gradually deflecting droplets into the appropriate channel, a “gapped divider” allows ten-fold faster sorting over other reported methods.
Real space probe of short-range interaction between Cr in a ferromagnetic semiconductor ZnCrTe
Authors: Kanazawa Ken , Nishimura Taku , Yoshida Shoji , Shigekawa Hidemi , Kuroda Shinji
Published: October 2014

We have revealed the short-range character of the magnetic interaction between Cr atoms in (Zn,Cr)Te by scanning tunneling microscopy.
Development of a novel fluorescence probe capable of assessing the cytoplasmic entry of siderophore-based conjugates
Authors: Kim Hyeon Seok , Song Woon Young , Kim Hak Joong
Published: October 2014

A novel fluorescence probe capable of assessing the cytoplasmic entry of siderophore-based conjugates was synthesized and evaluated by photochemical characterization and cell-based assays.
Giant piezoelectric properties of BZT–0.5BCT thin films induced by nanodomain structure
Authors: Li W. L. , Zhang T. D. , Hou Y. F. , Zhao Y. , Xu D. , Cao W. P. , Fei W. D.
Published: October 2014

Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 (BZT–0.5BCT) thin films were prepared from two ceramics targets, Ba(Zr0.2Ti0.8)O3 and (Ba0.7Ca0.3)TiO3, using dual-magnetron sputtering, and a LaNiO3 (LNO) seed layer was introduced between the film and Pt(111)/Ti/SiO2/Si substrates via a sol–gel technique.
Bicontinuous hierarchical Na7V4(P2O7)4(PO4)/C nanorod–graphene composite with enhanced fast sodium and lithium ions intercalation chemistry
Authors: Zhang Sen , Deng Chao , Meng Yu
Published: October 2014

Hierarchical Na7V4(P2O7)4(PO4)/C nanorod–graphene composite exhibits an enhanced fast sodium/lithium ions transport capability and superb electrochemical properties.
Assessment of polyanion (BF4− and PF6−) substitutions in hybrid halide perovskites
Authors: Hendon Christopher H. , Yang Ruo Xi , Burton Lee A. , Walsh Aron
Published: October 2014

The incorporation of tetrafluoroborate and hexafluorophosphate in halide perovskites is found to result in substantial band gap widening.
Rationally designed hierarchical ZnCo2O4/Ni(OH)2 nanostructures for high-performance pseudocapacitor electrodes
Authors: Chuo H. X. , Gao H. , Yang Q. , Zhang N. , Bu W. B. , Zhang X. T.
Published: October 2014

Hierarchical ZnCo2O4/Ni(OH)2 nanostructures were rationally designed and successfully fabricated. They show excellent electrochemical performances.
Water-soluble photoluminescent d-mannose and l-alanine functionalized silicon nanocrystals and their application to cancer cell imaging
Authors: Zhai Yi , Dasog Mita , Snitynsky Ryan B. , Purkait Tapas K. , Aghajamali Maryam , Hahn Allison H. , Sturdy Christopher B. , Lowary Todd L. , Veinot Jonathan G. C.
Published: October 2014

Mannose and alanine functionalized SiNPs have been synthesized, and these particles were evaluated as luminescent agents for imaging MCF-7 cells.
Polymer composites of boron nitride nanotubes and nanosheets
Authors: Meng Wenjun , Huang Yang , Fu Yuqiao , Wang Zifeng , Zhi Chunyi
Published: October 2014

A comprehensive review of polymer composites of BN nanotubes and nanosheets with distinguished properties.
Red Flags: Cochlear Implant Programming
Authors: Sladen Douglas P.
Published: October 2014

Consistent, full-time use of a well programmed cochlear implant (CI) is key for auditory and spoken language development. Young children with hearing loss often lack the requisite language skills to alert parents and clinicians when the CI needs to be re-programmed. The article within describes red flags used to indicate the levels of the device need to be reset.
Robust secrecy rate optimisations for multiuser multiple‐input‐single‐output channel with device‐to‐device communications
Authors: Chu Zheng , Cumanan Kanapathippillai , Xu Mai , Ding Zhiguo
Published: October 2014

In the present study, the authors investigate robust secrecy rate optimisation problems for a multiple‐input‐single‐output secrecy channel with multiple device‐to‐device (D2D) communications. The D2D communication nodes access this secrecy channel by sharing the same spectrum, and help to improve the secrecy communications by confusing the eavesdroppers. In return, the legitimate transmitter ensures that the D2D communication nodes achieve their required rates. In addition, it is assumed that the legitimate transmitter has imperfect channel state information of different nodes. For this secrecy network, the authors solve two robust secrecy rate optimisation problems: (a) robust power minimisation problem, subject to the probability based secrecy rate and the D2D transmission rate constraints; (b) robust secrecy rate maximisation problem with the transmit power, the probabilistic based secrecy rate and the D2D transmission rate constraints. Owing to the non‐convexity of robust beamforming design based on two statistical channel uncertainty models, the authors present two conservative approximation approaches based on ‘Bernstein‐type’ inequality and ‘S‐Procedure’ to solve these robust optimisation problems. Simulation results are provided to validate the performance of these two conservative approximation methods, where it is shown that ‘Bernstein‐type’ inequality based approach outperforms the ‘S‐Procedure’ approach in terms of achievable secrecy rates.
Comparison of adaptation motifs: temporal, stochastic and spatial responses
Authors: Iglesias Pablo A. , Shi Changji
Published: October 2014

The cells’ ability to adapt to changes in the external environment is crucial for the survival of many organisms. There are two broad classes of signalling networks that achieve perfect adaptation. Both rely on complementary regulation of the response by an external signal and an inhibitory process. In one class of systems, inhibition comes about from the response itself, closing a negative feedback (NFB) loop. In the other, the inhibition comes directly from the external signal in what is referred to as an incoherent feedforward (IFF) loop. Although both systems show adaptive behaviour to constant changes in the level of the stimulus, their response to other forms of stimuli can differ. Here the authors consider the respective response to various such disturbances, including ramp increases, removal of the stimulus and pulses. The authors also consider the effect of stochastic fluctuations in signalling that come about from the interaction of the signalling elements. Finally, the authors consider the possible effect of spatially varying signals. The authors show that both the NFB and the IFF motifs can be used to sense static spatial gradients, under a local excitation, global inhibition assumption. The results may help experimentalists develop protocols that can discriminate between the two adaptation motifs.
Low power on‐chip clocking for nanomagnetic logic circuits
Authors: Zhang Mingliang , Cai Li , Yang Xiaokuo , Cui Huanqing , Wang Zhichun , Feng Chaowen , Wang Sen
Published: October 2014

It is demonstrated that it is possible to switch the magnetisation of nanomagnets by employing the exchange interaction between magnets. This can implement on‐chip clocking for nanomagnetic logic circuits by using a current‐carrying copper wire circularly wrapped by ferromagnetic cladding. This scheme is potentially more energy efficient than yoked cladding clocking using an external magnetic field for magnetisation switching. Maxwell simulation shows that current flowing through copper wire can be reduced by about one hundred times compared with yoked clocking, which means power consumption could be lowered by 104 times. Micromagnetic simulation shows that the nanomagnetic chain aligned on the proposed clocking can achieve a correct functional state.
Fragmentation mechanism of UV-excited peptides in the gas phase
Authors: Zabuga Aleksandra V. , Kamrath Michael Z. , Boyarkin Oleg V. , Rizzo Thomas R.
Published: October 2014

We present evidence that following near-UV excitation, protonated tyrosine- or phenylalanine–containing peptides undergo intersystem crossing to produce a triplet species. This pathway competes with direct dissociation from the excited electronic state and with dissociation from the electronic ground state subsequent to internal conversion. We employ UV-IR double-resonance photofragment spectroscopy to record conformer-specific vibrational spectra of cold peptides pre-excited to their S1 electronic state. The absorption of tunable IR light by these electronically excited peptides leads to a drastic increase in fragmentation, selectively enhancing the loss of neutral phenylalanine or tyrosine side-chain, which are not the lowest dissociation channels in the ground electronic state. The recorded IR spectra evolve upon increasing the time delay between the UV and IR pulses, reflecting the dynamics of the intersystem crossing on a timescale of ∼80 ns and <10 ns for phenylalanine- and tyrosine-containing peptides, respectively. Once in the triplet state, phenylalanine-containing peptides may live for more than 100 ms, unless they absorb IR photons and undergo dissociation by the loss of an aromatic side-chain. We discuss the mechanism of this fragmentation channel and its possible implications for photofragment spectroscopy and peptide photostability.
Experimental comparison of grating- and propagation-based hard X-ray phase tomography of soft tissue
Authors: Lang S. , Zanette I. , Dominietto M. , Langer M. , Rack A. , Schulz G. , Le Duc G. , David C. , Mohr J. , Pfeiffer F. , Müller B. , Weitkamp T.
Published: October 2014

When imaging soft tissues with hard X-rays, phase contrast is often preferred over conventional attenuation contrast due its superior sensitivity. However, it is unclear which of the numerous phase tomography methods yields the optimized results at given experimental conditions. Therefore, we quantitatively compared the three phase tomography methods implemented at the beamline ID19 of the European Synchrotron Radiation Facility: X-ray grating interferometry (XGI), and propagation-based phase tomography, i.e., single-distance phase retrieval (SDPR) and holotomography (HT), using cancerous tissue from a mouse model and an entire heart of a rat. We show that for both specimens, the spatial resolution derived from the characteristic morphological features is about a factor of two better for HT and SDPR compared to XGI, whereas the XGI data generally exhibit much better contrast-to-noise ratios for the anatomical features. Moreover, XGI excels in fidelity of the density measurements, and is also more robust against low-frequency artifacts than HT, but it might suffer from phase-wrapping artifacts. Thus, we can regard the three phase tomography methods discussed as complementary. The application will decide which spatial and density resolutions are desired, for the imaging task and dose requirements, and, in addition, the applicant must choose between the complexity of the experimental setup and the one of data processing.
Influence of an anomalous dimension effect on thermal instability in amorphous-InGaZnO thin-film transistors
Authors: Liu Kuan-Hsien , Chang Ting-Chang , Chou Wu-Ching , Chen Hua-Mao , Tsai Ming-Yen , Wu Ming-Siou , Hung Yi-Syuan , Hung Pei-Hua , Hsieh Tien-Yu , Tai Ya-Hsiang , Chu Ann-Kuo , Yeh Bo-Liang
Published: October 2014

This paper investigates abnormal dimension-dependent thermal instability in amorphous indium-gallium-zinc-oxide (a-IGZO) thin-film transistors. Device dimension should theoretically have no effects on threshold voltage, except for in short channel devices. Unlike short channel drain-induced source barrier lowering effect, threshold voltage increases with increasing drain voltage. Furthermore, for devices with either a relatively large channel width or a short channel length, the output drain current decreases instead of saturating with an increase in drain voltage. Moreover, the wider the channel and the shorter the channel length, the larger the threshold voltage and output on-state current degradation that is observed. Because of the surrounding oxide and other thermal insulating material and the low thermal conductivity of the IGZO layer, the self-heating effect will be pronounced in wider/shorter channel length devices and those with a larger operating drain bias. To further clarify the physical mechanism, fast ID-VG and modulated peak/base pulse time ID-VD measurements are utilized to demonstrate the self-heating induced anomalous dimension-dependent threshold voltage variation and on-state current degradation.
Construction of a closed polymer network for computer simulations
Authors: Kamerlin Natasha , Ekholm Tobias , Carlsson Tobias , Elvingson Christer
Published: October 2014

Computer simulations are an important tool for linking the behaviour of polymer materials to the properties of the constituent polymer chains. In simulations, one normally uses periodic boundary conditions to mimic a macroscopic system. For a cross-linked polymer network, this will impose restrictions on the motion of the polymer chains at the borders of the simulation cell. We present a new method for constructing a three-dimensional closed network without periodic boundaries by embedding the system onto the surface of a sphere in four dimensions. This method can also be used to construct finite-sized gel particles for simulating the swelling of particles in a surrounding solvent. The method is described in algorithmic detail to allow the incorporation of the method into different types of simulation programs. We also present the results of Brownian dynamics simulations, analyzing the end-to-end distribution, radial distribution function, and the pore size distribution for different volume fractions and for chains with varying stiffness.
Optimized scalable stack of fluorescent solar concentrator systems with bifacial silicon solar cells
Authors: Martínez Díez Ana Luisa , Gutmann Johannes , Posdziech Janina , Rist Tim , Plaza David Gómez , Goldschmidt Jan Christoph
Published: October 2014

In this paper, we present a concentrator system based on a stack of fluorescent concentrators (FCs) and a bifacial solar cell. Coupling bifacial solar cells to a stack of FCs increases the performance of the system and preserves its efficiency when scaled. We used an approach to optimize a fluorescent solar concentrator system design based on a stack of multiple fluorescent concentrators (FC). Seven individual fluorescent collectors (20 mm × 20 mm × 2 mm) were realized by in-situ polymerization and optically characterized in regard to their ability to guide light to the edges. Then, an optimization procedure based on the experimental data of the individual FCs was carried out to determine the stack configuration that maximizes the total number of photons leaving edges. Finally, two fluorescent concentrator systems were realized by attaching bifacial silicon solar cells to the optimized FC stacks: a conventional system, where FC were attached to one side of the solar cell as a reference, and the proposed bifacial configuration. It was found that for the same overall FC area, the bifacial configuration increases the short-circuit current by a factor of 2.2, which is also in agreement with theoretical considerations.
Photocurrent collection efficiency mapping of a silicon solar cell by a differential luminescence imaging technique
Authors: Rau U. , Huhn V. , Stoicescu L. , Schneemann M. , Augarten Y. , Gerber A. , Pieters B. E.
Published: October 2014

A differential electroluminescence imaging method for solar cells which yields local photocurrent collection efficiency maps is introduced. These maps attribute a value between zero and unity to each location on the cell. This value corresponds to the ratio between the current at the cell terminals and the locally generated photocurrent. The method is demonstrated for a multicrystalline silicon solar cell under constant illumination. If the point of maximum power output of the cell is chosen as the bias point, the method yields quantitative information on the local contribution to the maximum output power of the solar cell.
Linear calculations of edge current driven kink modes with BOUT++ code
Authors: Li G. Q. , Xu X. Q. , Snyder P. B. , Turnbull A. D. , Xia T. Y. , Ma C. H. , Xi P. W.
Published: October 2014

This work extends previous BOUT++ work to systematically study the impact of edge current density on edge localized modes, and to benchmark with the GATO and ELITE codes. Using the CORSICA code, a set of equilibria was generated with different edge current densities by keeping total current and pressure profile fixed. Based on these equilibria, the effects of the edge current density on the MHD instabilities were studied with the 3-field BOUT++ code. For the linear calculations, with increasing edge current density, the dominant modes are changed from intermediate-n and high-n ballooning modes to low-n kink modes, and the linear growth rate becomes smaller. The edge current provides stabilizing effects on ballooning modes due to the increase of local shear at the outer mid-plane with the edge current. For edge kink modes, however, the edge current does not always provide a destabilizing effect; with increasing edge current, the linear growth rate first increases, and then decreases. In benchmark calculations for BOUT++ against the linear results with the GATO and ELITE codes, the vacuum model has important effects on the edge kink mode calculations. By setting a realistic density profile and Spitzer resistivity profile in the vacuum region, the resistivity was found to have a destabilizing effect on both the kink mode and on the ballooning mode. With diamagnetic effects included, the intermediate-n and high-n ballooning modes can be totally stabilized for finite edge current density.
Pressure-induced amorphization of a dense coordination polymer and its impact on proton conductivity
Authors: Umeyama Daiki , Horike Satoshi , Tassel Cedric , Kageyama Hiroshi , Higo Yuji , Hagi Keisuke , Ogiwara Naoki , Kitagawa Susumu
Published: October 2014

The proton conductivity of a dense coordination polymer (CP) was investigated under high-pressure conditions. Impedance measurements under high pressures revealed that the proton conductivity of the CP decreased more than 1000-fold at pressures of 3–7 GPa and that the activation energy for proton conduction almost doubled compared with that at ambient pressure. A synchrotron X-ray study under high pressure identified the amorphization process of the CP during compression, which rationally explains the decrease in conductivity and increase in activation energy. This phenomenon is categorized as reversible pressure-induced amorphization of a dense CP and is regarded as a demonstration of the coupling of the mechanical and electrical properties of a CP.
Comparison of fluctuating potentials and donor-acceptor pair transitions in a Cu-poor Cu2ZnSnS4 based solar cell
Authors: Teixeira J. P. , Sousa R. A. , Sousa M. G. , da Cunha A. F. , Fernandes P. A. , Salomé P. M. P. , González J. C. , Leitão J. P.
Published: October 2014

The structure of the electronic energy levels of a single phase Cu2ZnSnS4 film, as confirmed by Raman Scattering and x-ray diffraction, is investigated through a dependence on the excitation power of the photoluminescence (PL). The behavior of the observed asymmetric band, with a peak energy at ∼1.22 eV, is compared with two theoretical models: (i) fluctuating potentials and (ii) donor-acceptor pair transitions. It is shown that the radiative recombination channels in the Cu-poor film are strongly influenced by tail states in the bandgap as a consequence of a heavy doping and compensation levels. The contribution of the PL for the evaluation of secondary phases is also highlighted.