bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimicrobial acrylic materials with in situ generated silver nanoparticles
Authors: Oei James D. , Zhao William W. , Chu Lianrui , DeSilva Mauris N. , Ghimire Abishek , Rawls H. Ralph , Whang Kyumin
Published: November 2011

Polymethyl methacrylate (PMMA) is widely used to treat traumatic head injuries (cranioplasty) and orthopedic injuries (bone cement), but there is a problem with implant‐centered infections. With organisms such as Acinetobacter baumannii and methicillin‐resistant staphylococcus aureus developing resistance to antibiotics, there is a need for novel antimicrobial delivery mechanisms without risk of developing resistant organisms. Objectives: To develop a novel antimicrobial implant material by generating silver nanoparticles (AgNP) in situ in PMMA. Results: All PMMA samples with AgNP's (AgNP‐PMMA) released Ag+ ions in vitro for over 28 days. In vitro antimicrobial assays revealed that these samples (even samples with the slowest release rate) inhibited 99.9% of bacteria against four different strains of bacteria. Long‐term antimicrobial assay showed a continued antibacterial effect past 28 days. Some AgNP‐loaded PMMA groups had comparable Durometer‐D hardness (a measure of degree of cure) and modulus to control PMMA, but all experimental groups had slightly lower ultimate transverse strengths. Conclusions: AgNP‐PMMA demonstrated a tremendously broad‐spectrum and long‐intermediate‐term antimicrobial effect with comparable mechanical properties to control PMMA. Current efforts are focused on further improving mechanical properties by reducing AgNP loading and assessing fatigue properties. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 409–415, 2012.
Effect of fatigue on fracture toughness and phase transformation of Y‐TZP ceramics by X‐ray diffraction and Raman spectroscopy
Authors: Nemli Seçil Karakoca , Yilmaz Handan , Aydin Cemal , Bal Bilge Turhan , Tıraş Tülay
Published: November 2011

The aim of this study was to evaluate the effect of fatigue on fracture toughness and phase transformation of yttria‐stabilized zirconia polycrystal materials (Cercon and Lava). The specimens were tested for indentation fracture toughness either with or without being subjected to fatigue (20,000 cycles, 2 Hz, 200 N load). X‐ray diffraction (XRD) analysis was used to examine the phase composition of specimens. The indentation images were analyzed using Raman spectroscopy at indentation center (p1), indentation corner (p2), points on crack 100 μm (p3), and 200 μm (p4) away from the corner and a point ∼80 μm away from the crack (p5). Fracture toughness results were statistically analyzed by two‐way analysis of variance (ANOVA); XRD and Raman spectroscopy results were analyzed by three‐way ANOVA. Fracture toughness of Cercon control (CC) and fatigue (CF) groups were 6.8 and 6.9 MPa√m, respectively, with no significant difference (p> 0.01). Fracture toughness of Lava fatigue (LF; 7.3 MPa√m) was significantly higher than Lava control (LC;p< 0.01). XRD analyses showed CC and LC consisted of tetragonal zirconia, monoclinic zirconia detected after fatigue. After indentation, relative amount of monoclinic phase significantly increased in CC, CF, and LC; decreased in LF. The Raman spectroscopy results indicated that monoclinic fraction was the highest at p2, subsequently at p1 and decreased at p3, p4, and p5 for all groups. Mechanical cycling increased fracture toughness of Cercon and Lava, the second being significant. Phase transformation was also detected after fatigue, which is higher in Lava. Analysis of indentations showed that transformation was highest was at the corner, second at center. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 416–424, 2012.
Colorless and high strength MgO/Al2O3/SiO2 glass–ceramic dental material using zirconia as nucleating agent
Authors: Dittmer Marc , Rüssel Christian
Published: November 2011

Glasses in the system of MgO/Al2O3/SiO2 with different concentrations of zirconia as nucleating agent, some of them additionally doped with ZnO or P2O5, were annealed in a temperature range from 950 to 1150°C. The use of zirconia led to colorless glass–ceramics, which were transparent to opaque. In all studied compositions, α‐/β‐quartz‐solid‐solutions, zirconia as well as spinel or gahnite (ZnAl2O4)/spinel‐solid‐solution precipitated. The highest bending strength of 475 MPa was obtained after annealing at 1000°C for 3 h. The increase of the annealing temperature or an increase in the zirconia concentration resulted in an increase of the microhardness up to 13.3 GPa and of the fracture toughness up to 2.7 MPa m1/2. The addition of ZnO results in an increase of the hardness up to 12.5 GPa. The addition of ZnO or P2O5 led to a fracture toughness of 2 MPa m1/2. The described physical properties had to be highly advantageous for the preparation of colorless high strength dental glass–ceramics. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 100B: 463–470, 2012.
Design of designs
Authors: Laue Reinhard , Nikolova‐Popova Daniela
Published: November 2011

Representing a design graphically can make certain properties of a design obvious that otherwise would require tedious reasoning. This holds for symmetries, resolvability, and subdesign inclusion in appropriate cases. We describe how a graphical representation can be achieved in many cases and show several examples, in particular visualizations of the biplanes on up to 16 vertices and subdesigns of the large Witt design. © 2011 Wiley Periodicals, Inc. J Combin Designs 20:1–22, 2012
Vitamin C treatment promotes mesenchymal stem cell sheet formation and tissue regeneration by elevating telomerase activity
Authors: Wei Fulan , Qu Cunye , Song Tieli , Ding Gang , Fan Zhipeng , Liu Dayong , Liu Yi , Zhang Chunmei , Shi Songtao , Wang Songlin
Published: November 2011

Cell sheet engineering has been developed as an alternative approach to improve mesenchymal stem cell‐mediated tissue regeneration. In this study, we found that vitamin C (Vc) was capable of inducing telomerase activity in periodontal ligament stem cells (PDLSCs), leading to the up‐regulated expression of extracellular matrix type I collagen, fibronectin, and integrin β1, stem cell markers Oct4, Sox2, and Nanog as well as osteogenic markers RUNX2, ALP, OCN. Under Vc treatment, PDLSCs can form cell sheet structures because of increased cell matrix production. Interestingly, PDLSC sheets demonstrated a significant improvement in tissue regeneration compared with untreated control dissociated PDLSCs and offered an effective treatment for periodontal defects in a swine model. In addition, bone marrow mesenchymal stem cell sheets and umbilical cord mesenchymal stem cell sheets were also well constructed using this method. The development of Vc‐mediated mesenchymal stem cell sheets may provide an easy and practical approach for cell‐based tissue regeneration. J. Cell. Physiol. 227: 3216–3224, 2012. © 2011 Wiley Periodicals, Inc.
Depletion of GRIM‐19 accelerates hepatocellular carcinoma invasion via inducing EMT and loss of contact inhibition
Authors: Hao Hongbo , Liu Jun , Liu Guoliang , Guan Dongshi , Yang Yang , Zhang Xiuqing , Cao Xinmin , Liu Qian
Published: November 2011

Genes associated with retinoid‐interferon‐induced mortality 19 (GRIM‐19) was identified as a tumor suppressor protein associated with apoptosis and growth inhibition. Here, we report that the expression levels of GRIM‐19 are significantly attenuated in hepatocellular carcinoma (HCC) patients with deteriorating differentiation states, hepatic capsule invasion and microvascular invasion, suggesting the potential role of GRIM‐19 not only at the origin but also in the invasive progression of HCCs. To dissect the possible mechanisms by which GRIM‐19 regulates tumor cell invasion, we established the hepatic HL‐7702 and HCC Huh‐7 cell lines stably depleted of GRIM‐19. Results show that downregulation of GRIM‐19 induces a morphological transformation resembling epithelial–mesenchymal transition (EMT) as well as aberrant expression of epithelial and mesenchymal molecular markers. Additionally, these cells lose contact inhibition, a phenomenon of cessation of cell migration in contact with neighboring cells, as assessed by cell imaging, growth curve and S‐phase transition in confluent conditions. Conclusion: Our observations demonstrate a novel mechanistic insight into a critical role of GRIM‐19 in HCC invasive potential. J. Cell. Physiol. 227: 1212–1219, 2012. © 2011 Wiley Periodicals, Inc.
Tetrahydropyridinium bromide: Useful synthon to functionalized pyrrolidines
Authors: Guideri Luca , Noschese Rossella , Ponticelli Fabio
Published: November 2011

1‐benzyl‐5‐(ethoxycarbonyl)‐2,3,4,5‐tetrahydropyridinium bromide undergoes ring contraction with a series of nucleophiles, getting 2,2‐disubstitued pyrrolidines. Moreover, from some of the new 2,2‐disubstitued pyrrolidines were synthesized spiro‐pyrrolidines. J. Heterocyclic Chem.,(2011).
Improving stroke alert response time: Applying quality improvement methodology to the inpatient neurologic emergency
Authors: Cumbler Ethan , Zaemisch Rebekah , Graves Alexandra , Brega Kerry , Jones William
Published: November 2011

BACKGROUND:

Stroke often leaves its victims with devastating disabilities if not treated promptly. Guidelines recommend that brain imaging be obtained within 25 minutes, yet this benchmark is rarely achieved for the in‐hospital stroke.

PURPOSE:

To reduce time to evaluation for strokes occurring in patients already hospitalized, through systematic analysis of current processes and application of standardized quality improvement methodology.

METHODS:

Improving the quality of care for in‐hospital stroke patients involved 4 key steps: (1) creation of a detailed process map to identify inefficiencies in the current process for identifying and treating hospitalized stroke patients, (2) development of an optimized care pathway, (3) implementation of a checklist of optimal practices for the acute stroke response team and nursing staff, and (4) real‐time feedback. Time from stroke alert to initiation of computed tomography (CT) scan was prospectively tracked for the 6‐month period prior to intervention. After a 3‐month interval for intervention roll‐out, the response times for the pre‐intervention period were compared to a 6‐month post‐intervention evaluation period.

RESULTS:

Pre‐intervention median inpatient stroke alert‐to‐CT time was 69.0 minutes, with 19% meeting the goal of 25 minutes from alert to CT time. Post‐intervention median inpatient stroke alert‐to‐CT time was reduced to 29.5 minutes, with 32% at goal (P < 0.0001).

CONCLUSIONS:

This inpatient stroke alert quality improvement initiative decreased median inpatient alert‐to‐CT time by 57%, and demonstrated that speed of in‐hospital stroke evaluation can be improved through systematic application of quality improvement principles. Journal of Hospital Medicine 2012; © 2011 Society of Hospital Medicine
Exogenous and autocrine growth factors stimulate human intervertebral disc cell proliferation via the ERK and Akt pathways
Authors: Pratsinis Harris , Constantinou Vasos , Pavlakis Kitty , Sapkas George , Kletsas Dimitris
Published: November 2011

Intervertebral disc (IVD) degeneration is accompanied by growth factor‐overexpression and increased cell proliferation, probably representing a tissue repair process. Accordingly, we studied the effect of exogenous and autocrine growth factors on the proliferation of human IVD cells. We observed that Platelet‐Derived Growth Factor (PDGF), basic Fibroblast Growth Factor (bFGF), and Insulin‐like Growth Factor‐I (IGF‐I) stimulate DNA synthesis of human IVD cells, through the activation of the MEK/ERK and the PI‐3K/Akt signal transduction pathways. Furthermore, medium conditioned (CM) by IVD cells induced DNA synthesis in the same cells, indicating the secretion of autocrine growth factors. The MEK/ERK and PI‐3K/Akt pathways were also induced by CM, while their inhibition reversed in large part the DNA synthesis induction by CM. These responses to the exogenous and autocrine growth factors were qualitatively similar in both nucleus pulposus (NP) and annulus fibrosus (AF) cell cultures. Immunohistochemical studies in human biopsies showed significant activation of both signaling pathways, which was most prominent in the clusters of proliferating cells. These in vitro and in vivo data indicate that the proliferation of human IVD cells is regulated by exogenous and autocrine growth factors mainly via the MEK/ERK and PI‐3K/Akt pathways; this may contribute to the design of future interventional approaches. © 2011 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 30:958–964, 2012
Late nitrogen fertilization affects nitrogen remobilization in wheat
Authors: Fuertes‐Mendizábal Teresa , González‐Murua Carmen , González‐Moro Ma. B. , Estavillo José M.
Published: November 2011

A pot experiment with wheat plants was carried out to study how late application of nitrogen (N) fertilizer affects the use of pre‐anthesis N reserves during the grain‐filling period. Increasing doses of N fertilizer were applied (0, 40, and 52 mg N plant–1), either in two amendments (growth stages GS20 and GS30, according to Zadoks scale) or in three amendments (GS20, GS30, and GS37). The experiment was arranged in a complete randomized three‐block design with 129 plants per treatment. The plants were watered daily, harvested every 2 d between anthesis and maturity, and were separated into roots, leaf sheaths, leaf blades, and ears for further N determination. Grain N concentration improved due to a late N application in GS37 by 14% (higher N dose) and by 7% (further splitting the same N‐fertilizer dose, respectively). The higher the N‐fertilizer dose applied, the greater was the amount of pre‐anthesis reserves in vegetative organs, these reserves became later available for remobilization. Although splitting the same N dose in three amendments did not increase the N reserves, these reserves were more efficiently remobilized allowing an improvement in grain N concentration. The fertilizer management did not change the temporary pattern of N accumulation in the ear, but did induce a change in the amount of N remobilized and in the contribution of each organ (root, leaf sheath, leaf blade) to this remobilization. Late N amendment allowed a greater N availability of leaf blades and ear N reserves (from 20% up to 26% and from 19% up to 22%, respectively) for remobilization towards the grain, decreasing the root contribution from 28% down to 15%, while the contribution of leaf sheaths was maintained around 35% irrespective of the N applied.
Determination of phenolic compounds in environmental water samples after solid‐phase extraction with β‐cyclodextrin‐bonded silica particles coupled with a novel liquid‐phase microextraction followed by gas chromatography‐mass spectrometry
Authors: Faraji Hakim , Husain Syed W. , Helalizadeh Masoumeh
Published: November 2011

A novel approach for the sample pre‐treatment and determination of eight phenolic compounds in environmental water samples has been developed by hyphenating solid‐phase extraction (SPE) and liquid‐phase microextraction (LPME) techniques based on solid organic drop combined with gas chromatography‐mass spectrometry detection (GC‐MS). After pre‐concentration and purification of the sample through column containing 60 mg of β‐cyclodextrin‐bonded silica particles as stationary phase, under the optimum conditions, LPME technique has been performed on the eluent solution. Under the selected conditions, limit of detection (LOD) of 0.002–0.04 μg/L (S/N=3), limit of quantification (LOQ) of 0.007–0.15 μg/L (S/N=10), pre‐concentration factor of 752–3135 and linearity range of 0.01–25 μg/L have been obtained. A reasonable repeatability (RSD≤9.5%, n=5) with satisfactory coefficient of determination has been obtained between 0.9981 and 0.9997. The relative recoveries of the waste, sea, river and well water samples were higher than 79%.
Microstrip dual‐band bandpass and bandstop filters
Authors: Vegesna Subash , Saed Mohammad
Published: November 2011

In this letter, simple and effective design of dual‐band bandpass and bandstop filters using microstrip open‐loop resonators is proposed.The dual‐band bandpass and bandstop filters developed in this letter exhibit dual operating frequencies that are not integral multiples of each other and are realized using a simple method rather than using the extensive method of extracting coupling coefficient matrix for designing dual‐band filters. Parametric analysis is performed on the proposed microstrip structures to determine the optimum dimensions of the dual‐band filters. Both simulation and measured results are presented in this letter, and good agreement is obtained between the results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:168–171, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26469
New coupled‐line dual‐band dc‐block transformer for arbitrary complex frequency‐dependent load impedance
Authors: Wu Yongle , Liu Yuanan , Li Shulan , Yu Cuiping
Published: November 2011

A novel impedance transformer is constructed by interpolating coupled line in this article. This proposed coupled‐line transformer not only has arbitrary dual‐band operation for arbitrary complex frequency‐dependent load impedance but also features inherent DC‐block function. The design of its electrical parameters can be obtained by using simple closed‐form design equations. Furthermore, the practical scope of load impedance for this transformer is analyzed, and the corresponding analytical design approach is verified by seven numerical examples. Finally, experimental results for a microstrip coupled‐line dual‐band impedance transformer with center frequencies at 1.45 and 2.61 GHz are in excellent agreement with the circuit‐based simulated results. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:139–142, 2012; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26480
Enhancing ground plane immunity of dipole antennas with spin–spray‐deposited lossy ferrite films
Authors: Yang Guo‐Min , Obi Ogheneyunume , Sun Nian X.
Published: November 2011

This article presented a low‐profile dipole antenna with enhanced ground immunity by using spin–spray‐deposited ferrite films. To reduce the mutual coupling between the antenna and the ground plane, Fe3O4–ferrite films were added below the dipole antenna. Novel dipole antennas with lossy Fe3O4–ferrite films loading were designed and analyzed. Under the condition of low profile of 2 mm, a good reflection coefficient of −24.6 dB was obtained when antennas were loaded with lossy ferrite films, which shows great promising for the antenna miniaturization in the modern wireless communication. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett 54:230–233, 2012.
Strain and satisfaction in caregivers of veterans with chronic illness
Authors: Wakefield Bonnie J. , Hayes Jeanne , Boren Suzanne Austin , Pak Youngju , Davis J. Wade
Published: November 2011

Veterans' health care has shifted towards outpatient treatment, and because of the high prevalence of chronic illness in veterans, more caregiving has been required of their families. The purpose of this study was to identify predictors of caregiver (CG) strain and satisfaction associated with caring for veterans with chronic illness. Data were collected using telephone interviews of 120 dyads. Strain was associated with helping with instrumental activities of daily living, using counseling and prayer for coping, accompanying veteran to appointments, help/advice from friends, paid help, exercising, and depression. Satisfaction was associated with veteran health, CG social support, age, and depression. Innovative and easily accessible interventions are needed to mitigate sources of strain in CGs of chronically ill veterans. Published 2011. This article is a U.S. Government work and is in the public domain in the USA. Res Nurs Health
35:55‐69, 2012
Dental Anomalies in the Mandible of Capra pyrenaica: Presence of Two Permanent Fourth Premolars in a Pleistocene Wild Goat from Arlanpe Cave (Bizkaia, Northern Spain)
Authors: Gómez‐Olivencia Asier , Arceredillo Diego , Rios‐Garaizar Joseba , Garate Diego , Iriarte Eneko , Pedro Ziortza San
Published: November 2011

In this study, we report a case of duplication of a lower fourth premolar (P4) on an Iberian wild goat from the archaeological site cave of Arlanpe, (Lemoa, Bizkaia, Northern Spain). The preserved right mandible corpus displays two premolars and the first molar (M1). Both premolars conform in size and general shape to fourth premolars (P4) but the medialmost of the two is rotated 90° counterclockwise, and thus, its wear pattern is different. The comparative analysis to other bovids and the relative scarcity of this anomaly compared to other cases of polydontia and hypodontia suggest that it is a developmental defect consisting in the duplication of the tooth germ, and we doubt on the potential of this abnormality as a territorially based indicator of past wild populations as has been previously proposed. Copyright © 2011 John Wiley & Sons, Ltd.
Low‐grade serous carcinomas of the ovary contain very few point mutations
Authors: Jones Siân , Wang Tian‐Li , Kurman Robert J , Nakayama Kentaro , Velculescu Victor E , Vogelstein Bert , Kinzler Kenneth W , Papadopoulos Nickolas , Shih Ie‐Ming
Published: November 2011

It has been well established that ovarian low‐grade and high‐grade serous carcinomas are fundamentally different types of tumours. While the molecular genetic features of ovarian high‐grade serous carcinomas are now well known, the pathogenesis of low‐grade serous carcinomas, apart from the recognition of frequent somatic mutations involving KRAS and BRAF, is largely unknown. In order to comprehensively analyse somatic mutations in low‐grade serous carcinomas, we applied exome sequencing to the DNA of eight samples of affinity‐purified, low‐grade, serous carcinomas. A remarkably small number of mutations were identified in seven of these tumours: a total of 70 somatic mutations in 64 genes. The eighth case displayed mixed serous and endometrioid features and a mutator phenotype with 783 somatic mutations, including a nonsense mutation in the mismatch repair gene, MSH2. We validated representative mutations in an additional nine low‐grade serous carcinomas and 10 serous borderline tumours, the precursors of ovarian low‐grade, serous carcinomas. Overall, the genes showing the most frequent mutations were BRAF and KRAS, occurring in 10 (38%) and 5 (19%) of 27 low‐grade tumours, respectively. Except for a single case with a PIK3CA mutation, other mutations identified in the discovery set were not detected in the validation set of specimens. Our mutational analysis demonstrates that point mutations are much less common in low‐grade serous tumours of the ovary than in other adult tumours, a finding with interesting scientific and clinical implications. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Solid‐state NMR reveals differences in the packing arrangements of peptide aggregates derived from the aortic amyloid polypeptide medin
Authors: Davies Hannah A. , Madine Jillian , Middleton David A.
Published: November 2011

Several polypeptides aggregate into insoluble amyloid fibrils associated with pathologies such as Alzheimer's disease, Parkinson's disease and type 2 diabetes. Understanding the structural and sequential motifs that drive fibrillisation may assist in the discovery and refinement of effective therapies. Here we investigate the effects of three predicted amyloidogenic regions on the structure of aggregates formed by medin, a poorly characterised polypeptide associated with aortic medial amyloidosis. Solid‐state NMR is used to compare the dynamics and sheet packing arrangement of the C‐terminal region encompassing residues F43GSV within full‐length medin (Med1‐50) and two shorter peptide fragments, Med30‐50 and Med42‐49, lacking specific sequences predicted to be amyloidogenic.. Results show that all three peptides have different aggregate morphologies, and Med30‐50 and Med1‐50 have different sheet packing arrangements and dynamics to Med42‐49. These results imply that at least two of the three predicted amyloidogenic regions are required for the formation and elongation of medin fibres observed in the disease state. Copyright © 2011 European Peptide Society and John Wiley & Sons, Ltd.
Ferromagnetism in rare earth doped cerium oxide bulk samples
Authors: Dimri M. Chandra , Khanduri H. , Kooskora H. , Subbi J. , Heinmaa I. , Mere A. , Krustok J. , Stern R.
Published: November 2011

Magnetic properties of rare earth (RE) doped ceria (RE = Nd, Sm, Gd, Tb, Er and Dy) samples have been investigated and reported in this paper. Room temperature ferromagnetism (FM) was observed in calcined powders as well as in sintered samples of Nd and Sm doped CeO2, whereas other RE dopants (Gd, Tb, Er and Dy) in CeO2 exhibit paramagnetic behaviour. The origin of magnetism in these samples can be related to oxygen vacancies and formation of fluorite crystal structure. Though the magnetization was found to be lower as compared to transition metal (TM) doped ceria, the segregation of metallic and secondary phases can be avoided in RE doped CeO2. CeO2 doped with Sm ions in different concentration (1, 5 and 15%) were also studied to see the dopant effects on magnetic properties. The origin of magnetism in these samples may be related to the oxygen vacancies created due to RE dopants, which was confirmed from the peak around 555 cm−1 in Raman spectra.
Morphology evolution and optical properties of GaN nano‐pyramids grown by selective area MOVPE
Authors: Winden Andreas , Mikulics Martin , Haab Anna , Stoica Toma , von der Ahe Martina , Wirtz Konrad , Hardtdegen Hilde , Grützmacher Detlev
Published: November 2011

The evolution of GaN nano‐pyramid growth by selective area metalorganic vapor phase epitaxy (SA‐MOVPE) on GaN/c‐plane sapphire templates with extremely low pattern fill factor and large inter‐hole spacing was studied with scanning electron microscopy (SEM). The optical nanostructure characteristics were investigated by micro‐photoluminescence spectroscopy at room temperature. It was found that sub‐100 nm structures can be fabricated by controlling the growth time and mask opening size. Single nanostructures exhibit more intense luminescence and a red shift of the band edge transition compared to the GaN layer. (© 2012 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preparation of stable aqueous conductive ink with silver nanoflakes and its application on paper‐based flexible electronics
Authors: Tai Yan‐Long , Yang Zhen‐Guo
Published: November 2011

A new kind of stable aqueous conductive ink with silver nanoflakes was developed, which was also used to fabricate conductive patterns on weighing paper for flexible electronics by direct writing. Silver nanoflakes of different sizes were characterized by transmission electron microscopy. The physical properties of the conductive ink were investigated by a dynamic contact angle system, Ubbelohde viscometer, and a surface tension instrument. Conductive properties of paper‐based conductive patterns were also investigated by 4‐point probe, scanning electron microscopy, X‐ray diffraction and Uscan explorer with a 3D profilometer system. It is demonstrated how the formulation of conductive ink affects the surface morphology, microstructure conductivity, and line width of conductive patterns. It can be obtained that the paper‐based conductive patterns have low resistivity. Especially, when the sintering condition is 200 °C for 20 min, the resistivity can be down to 9.4 μΩ•cm. The application of the ink on an antenna for radio frequency identification was also studied. Copyright © 2011 John Wiley & Sons, Ltd.
Flexible Field Emission from Thermally Welded Chemically Doped Graphene Thin Films
Authors: Jeong Hee Jin , Jeong Hae Deuk , Kim Ho Young , Kim Sung Hun , Kim Jun Suk , Jeong Seung Yol , Han Joong Tark , Lee Geon‐Woong
Published: November 2011

Flexible field‐emission devices (FEDs) based on reduced graphene oxide (RGO) emitters are fabricated by the thermal welding of RGO thin films onto a polymeric substrate. The RGO edges are vertically aligned relative to the substrate as a result of cohesive failure in the RGO layer after thermal welding. Even at large bending angles, excellent electron emission properties, such as low turn‐on and threshold fields, a high emission current density, a high field enhancement factor, and long‐term stability of the emission properties of RGO emitters, arise from the uniform distribution and high density of the extremely sharp RGO edges, as well as the high interfacial strength between the RGO emitters and the substrate. Al‐ and Au‐doped RGO emitters are fabricated by introducing a dopant solution to the RGO emitters, and the resulting field‐emission characteristics are discussed. The proposed approach is straightforward and enables the practical use of high‐performance RGO flexible FEDs.
Recent trends in conformational analysis
Authors: Mazzanti Andrea , Casarini Daniele
Published: November 2011

An outlook of the various research fields of organic chemistry where conformational analysis plays a fundamental role is presented. The section Methodologies for Conformational Analysis is focused on the information that can be obtained by various spectroscopic techniques such as nuclear magnetic resonance and optical methods such as electronic circular dichroism and vibrational circular dichroism. A comprehensive screening of the more recent ab initio and density functional theory theoretical approaches to conformational analysis is presented in the section Theoretical Conformational Analysis. The section Application of Conformational Analysis to the Determination of the AC of Organic Molecules shows how the synergic use of experimental and theoretical methods can solve challenging conformational tasks arising from modern organic chemistry. © 2011 John Wiley & Sons, Ltd.

This article is categorized under:

Electronic Structure Theory > Density Functional Theory
Multiconfiguration second‐order perturbation theory approach to strong electron correlation in chemistry and photochemistry
Authors: Roca‐Sanjuán Daniel , Aquilante Francesco , Lindh Roland
Published: November 2011

Rooted in the very fundamental aspects of many chemical phenomena, and for the majority of photochemistry, is the onset of strongly interacting electronic configurations. To describe this challenging regime of strong electron correlation, an extraordinary effort has been put forward by a young generation of scientists in the development of theories ‘beyond’ standard wave function and density functional models. Despite their encouraging results, a twenty‐and‐more‐year old approach still stands as the gold standard for these problems: multiconfiguration second‐order perturbation theory based on complete active space reference wave function (CASSCF/CASPT2). We will present here a brief overview of the CASSCF/CASPT2 computational protocol, and of its role in our understanding of chemical and photochemical processes. © 2011 John Wiley & Sons, Ltd.

This article is categorized under:

Electronic Structure Theory > Ab Initio Electronic Structure Methods
Grassland bird nest ecology and survival in upland habitat buffers near wooded edges
Authors: Conover Ross R. , Burger L. Wes , Linder Eric T.
Published: November 2011

Upland habitat buffers (i.e., strips of noncrop, herbaceous vegetation) that are established adjacent to wooded fencerows offer landowners an economical option to provide wildlife benefits within intensive agricultural landscapes. However, being located near a wooded edge may increase grassland bird vulnerability to edge effects through reduced nest survival. We examined nesting bird communities in field margins adjacent to wooded field edges with no buffer (i.e., control), narrow (approx. 10‐m) buffers, and wide (approx. 30‐m) buffers in an intensive agricultural system in the Lower Mississippi Alluvial Valley, United States. Dickcissel (Spiza americana) and red‐winged blackbird (Agelaius phoeniceus) accounted for 97% of nests. Nest density was >7 times greater in wide buffers than in narrow. We modeled nest survival in Program MARK as a function of time (yr and season), nest‐site, and local vegetation characteristics. Nest survival was influenced by among‐ and within‐season temporal effects and local vegetation structure, but not by buffer width. Nest success varied substantially between years and within seasons for dickcissel (12.9% and 19.1% early in the seasons of 2003 and 2004, respectively), but not for red‐winged blackbird (15.1%). Overall nest‐success estimates were similar to noncrop, herbaceous strips elsewhere in the United States, though whether or not these estimates represent population sinks remains uncertain. Based on this research, we advocate integrating upland habitat buffers within intensive agricultural landscapes and emphasize the use of wide buffers when grassland‐nesting birds are a conservation priority. © 2011 The Wildlife Society.
Update and new concepts in vitamin responsive disorders of folate transport and metabolism
Authors: Watkins David , Rosenblatt David S.
Published: November 2011

Derivatives of folic acid are involved in transfer of one‐carbon units in cellular metabolism, playing a role in synthesis of purines and thymidylate and in the remethylation of homocysteine to form methionine. Five inborn errors affecting folate transport and metabolism have been well studied: hereditary folate malabsorption, caused by mutations in the gene encoding the proton‐coupled folate transporter (SLC46A1); glutamate formiminotransferase deficiency, caused by mutations in the FTCD gene; methylenetetrahydrofolate reductase deficiency, caused by mutations in the MTHFR gene; and functional methionine synthase deficiency, either as the result of mutations affecting methionine synthase itself (cblG, caused by mutations in the MTR gene) or affecting the accessory protein methionine synthase reductase (cblE, caused by mutations in the MTRR gene). Recently additional inborn errors have been identified. Cerebral folate deficiency is a clinically heterogeneous disorder, which in a few families is caused by mutations in the FOLR1 gene. Dihydrofolate reductase deficiency is characterized by megaloblastic anemia and cerebral folate deficiency, with variable neurological findings. It is caused by mutations in the DHFR gene. Deficiency in the trifunctional enzyme containing methylenetetrahydrofolate dehydrogenase, methenyltetrahydrofolate cyclohydrolase and formyltetrahydrofolate synthetase activities, has been identified in a single patient with megaloblastic anemia, atypical hemolytic uremic syndrome and severe combined immune deficiency. It is caused by mutations in the MTHFD1 gene.
ESR guidelines for the communication of urgent and unexpected findings
Authors:   European Society of Radiology (ESR)
Published: November 2011

The timely communication of radiological findings is important for patient care. When imaging reveals abnormalities that require urgent action, or shows significant unexpected findings, the usual methods of communication may not be reliable enough to ensure that those responsible for clinical care of the patient act promptly. These guidelines suggest methods for improving communication in these circumstances, using clear protocols and procedures agreed between imaging units and referrers.

Main Messages

• Communicating critical radiological findings will enable urgent or appropriate action to be taken.

• Good communication helps to improve patient safety.

• Clear departmental protocols become familiar to referrers within the organisation.

• Referrers should be aware of their responsibility to read and act on radiological reports.
Impact of fire on long-term vegetation dynamics of ombrotrophic peatlands in northwestern Québec, Canada
Authors: Magnan Gabriel , Lavoie Martin , Payette Serge
Published: November 2011

A 7000-year record of local fire history was reconstructed from three ombrotrophic peatlands in the James Bay lowlands (northwestern Québec, Canada) using a high-resolution analysis of macroscopic charcoal (long axis≥0.5 mm). The impact of fire on vegetation changes was evaluated using detailed analysis of plant macrofossils. Compared to upland boreal forest, fire incidence in theseSphagnum-dominated bogs is rather low. Past fire occurrence seems to have been controlled primarily by internal processes associated with local hydroseral succession. Size of the peatland basin and distance from the well-drained forest soils also appear to be factors controlling fire occurrence. The impact of peatland fires on long-term vegetation succession appears negligible except in a forested bog, where it initiated the replacement ofSphagnumby mosses. In some circumstances, fire caused marked changes in the bryophyte assemblages over many decades. However, ombrotrophic peatland vegetation is generally resilient to surface fire.
Transition to turbulence in shock-driven mixing: a Mach number study
Authors: Lombardini M. , Pullin D. I. , Meiron D. I.
Published: November 2011

Large-eddy simulations of single-shock-driven mixing suggest that, for sufficiently high incident Mach numbers, a two-gas mixing layer ultimately evolves to a late-time, fully developed turbulent flow, with Kolmogorov-like inertial subrange following a $\ensuremath{-} 5/ 3$ power law. After estimating the kinetic energy injected into the diffuse density layer during the initial shock–interface interaction, we propose a semi-empirical characterization of fully developed turbulence in such flows, based on scale separation, as a function of the initial parameter space, as $({\eta }_{{0}^{+ } } \mrm{\Delta} u/ \nu )\hspace{0.167em} ({\eta }_{{0}^{+ } } / {L}_{\rho } )\hspace{0.167em} {A}^{+ } / \sqrt{1\ensuremath{-} {A}^{{ \mathop{ + }\nolimits }^{2} } } \gtrsim 1. 53\ensuremath{\times} 1{0}^{4} / {\mathscr{C}}^{2} $, which corresponds to late-time Taylor-scale Reynolds numbers ${\gtrsim }250$. In this expression, ${\eta }_{{0}^{+ } } $ represents the post-shock perturbation amplitude, $ \mrm{\Delta} u$ the change in interface velocity induced by the shock refraction, $\nu $ the characteristic kinematic viscosity of the mixture, ${L}_{\rho } $ the inner diffuse thickness of the initial density profile, ${A}^{+ } $ the post-shock Atwood ratio, and $\mathscr{C}({A}^{+ } , {\eta }_{{0}^{+ } } / {\lambda }_{0} )\approx 0. 3$ for the gas combination and post-shock perturbation amplitude considered. The initially perturbed interface separating air and SF6 (pre-shock Atwood ratio $A\approx 0. 67$) was impacted in a heavy–light configuration by a shock wave of Mach number ${M}_{I} = 1. 05$, 1.25, 1.56, 3.0 or 5.0, for which ${\eta }_{{0}^{+ } } $ is fixed at about 25 % of the dominant wavelength ${\lambda }_{0} $ of an initial, Gaussian perturbation spectrum. Only partial isotropization of the flow (in the sense of turbulent kinetic energy and dissipation) is observed during the late-time evolution of the mixing zone. For all Mach numbers considered, the late-time flow resembles homogeneous decaying turbulence of Batchelor type, with a turbulent kinetic energy decay exponent $n\approx 1. 4$ and large-scale ($k\ensuremath{\rightarrow} 0$) energy spectrum $\ensuremath{\sim} {k}^{4} $, and a molecular mixing fraction parameter, $\Theta \approx 0. 85$. An appropriate time scale characterizing the Taylor-scale Reynolds number decay, as well as the evolution of mixing parameters such as $\Theta $ and the effective Atwood ratio ${A}_{e} $, seem to indicate the existence of low- and high-Mach-number regimes.
Identification of multipoles via boundary measurements
Authors: CHUNG Y.-S. , KIM J. E. , CHUNG S.-Y.
Published: November 2011

This paper provides an algorithm for identifying the multipoles of a meromorphic function from the boundary measurements, which can be applied to inverse source problems for a Poisson equation to reconstruct its source such as linear combination of mono and dipolar point sources. After establishing an algorithm that allows to identify the number, the locations and the moments of poles, we provide a stability estimate of the algorithm under the measurement error.
EPIDEMIOLOGICAL EVIDENCE IN PROOF OF SPECIFIC CAUSATION
Authors: Broadbent Alex
Published: November 2011

This paper seeks to determine the significance, if any, of epidemiological evidence to prove the specific causation element of liability in negligence or other relevant torts—in particular, what importance can be attached to a relative risk (RR) > 2, where that figure represents a sound causal inference at the general level. The paper discusses increased risk approaches to epidemiological evidence and concludes that they are a last resort. The paper also criticizes the proposal that the probability of causation can be estimated with reference to the RR, such that RR > 2 is necessary and sufficient for causation. It is argued, following arguments by Sander Greenland and others, that RR > 2 is not necessary for proof of specific causation, except under restrictive biological assumptions that are not known to be satisfied for any important disease, and therefore must never be required. However, the paper argues that in some circumstances RR > 2 can be sufficient to prove causation at law. This position is defended against the widely held judicial and academic view that epidemiological evidence must be accompanied by something else, particular to the case at hand, if it is to have probative force for specific causation. It is argued that far from being epistemically irrelevant, to achieve correct and just outcomes it is in fact mandatory to take (high-quality) epidemiological evidence into account in deciding specific causation. Failing to consider such evidence when it is available leads to error and injustice. The conclusion is that in certain circumstances epidemiological evidence of RR > 2 is not necessary to prove specific causation but that it is sufficient. This “sufficiency” is confined to circumstances where there is no other evidence, as a way of getting clear on what the epidemiological evidence says. Once we have worked out what it says, this must be weighed against the other relevant evidence, if there is any.
The spiritual strength story in end-of-life care: Two case studies
Authors: Mundle Robert G.
Published: November 2011

In this article I analyze two brief case studies to propose that a “spiritual strength story” has five defining characteristics: (1) it is brief; (2) it is ontological; (3) it uses symbols and metaphors; (4) it is a “big story” or meta-narrative with a positive spiritual and/or religious focus that informs other narrative data; and (5) most conspicuously of all, it repeats. Cultivating awareness of the “spiritual strength” narrative type can help to improve the quality of inter-professional patient-centered care teamwork and understanding, especially in regard to the reflexive, embodied, and relational aspects of palliative and end-of-life care.
North African dust export and deposition: A satellite and model perspective
Authors: Ridley D. A. , Heald C. L. , Ford B.
Published: November 2011

We use a suite of satellite observations (Moderate Resolution Imaging Spectroradiometer (MODIS), Multiangle Imaging Spectroradiometer (MISR), Cloud‐Aerosol Lidar With Orthogonal Polarization (CALIOP)) to investigate the processes of long‐range transport of dust represented in the global GEOS‐Chem model in 2006–2008. A multiyear mean of African dust transport is developed and used to test the representation of the variability in the model. We find that both MODIS and MISR correlate well with the majority of Aerosol Robotic Network observations in the region (r> 0.8). However, MODIS aerosol optical depth (AOD) appears to be biased low (>0.05) relative to MISR in Saharan regions during summer. We find that GEOS‐Chem captures much of the variability in AOD when compared with MISR and MODIS (r> 0.6) and represents the vertical structure in aerosol extinction over outflow regions well when compared to CALIOP. Including a realistic representation of the submicron‐size distribution of dust reduces simulated AOD by ∼25% over North Africa and improves agreement with observations. The lifetime of the simulated dust is typically a few days (25%–50%) shorter than inferred from MODIS observations, suggesting overvigorous wet removal, confirmed by comparison with rain rate observations from the Tropical Rainfall Measuring Mission satellite. The simulation captures the seasonality of deposition in Florida and the observed magnitude and variability of dust concentrations at Barbados from 2006 to 2008 (r = 0.74), indicating a good simulation of the impacts of North African dust on air quality in North America. We estimate that 218 ± 48 Tg of dust is annually deposited into the Atlantic and calculate a lower estimate for the dust deposited in the Caribbean and Amazon to be 26 ± 5 Tg yr−1 and 17 ± 5 Tg yr−1, respectively. This suggests that the dust deposition in the Amazon derived from satellites may be an upper limit.
Estimating effects of plantation expansion and climate variability on streamflow for catchments in Australia
Authors: Zhang Lu , Zhao Fangfang , Chen Yun , Dixon Renee N. M.
Published: November 2011

Plantation forestry is an increasingly important land use in Australia. While plantations can present significant environmental benefits such as salinity and erosion controls, their impact on streamflow needs to be recognized. This study evaluated the impacts of plantation and climate variability on streamflow from catchments in Australia. In total 15 catchments were selected based on the availability of streamflow, meteorological, and plantation information. The catchment areas range from 0.6 to 1136 km2 and represent different climatic conditions and management practices. The Mann–Kendall test was used to estimate trends in the annual streamflow, rainfall, potential evaporation, and runoff ratio. The plantation effect on streamflow was determined with the time‐trend analysis method, while the effect of climate variability was calculated using the sensitivity‐based approach. All the selected catchments showed reductions in annual streamflow and runoff ratio over the period of the records. The results indicate that plantation expansions accounted for 28% to 106% of the observed total streamflow reductions, while climate variability was responsible for 5% to 80% of the total streamflow reductions. It is evident that both plantation expansions and climate variability contributed to the observed streamflow reductions. In most of the catchments, the effect of plantation expansion on streamflow was more important than that of climate variability and is likely to have exacerbated the effect of climate variability on streamflow. Plantation expansions can reduce streamflow from both small and large catchments as this study demonstrated and the relative streamflow reduction can be linearly related to percentage plantation area in a catchment.