bluuebunny/crossref_metadata_2025 huggingface dataset:
Coordinated observations of sprites and in‐cloud lightning flash structure
Authors: Lu Gaopeng , Cummer Steven A. , Li Jingbo , Zigoneanu Lucian , Lyons Walter A. , Stanley Mark A. , Rison William , Krehbiel Paul R. , Edens Harald E. , Thomas Ronald J. , Beasley William H. , Weiss Stephanie A. , Blakeslee Richard J. , Bruning Eric C. , MacGorman Donald R. , Meyer Tiffany C. , Palivec Kevin , Ashcraft Thomas , Samaras Tim
Published: May 2013

The temporal and spatial development of sprite‐producing lightning flashes is examined with coordinated observations over an asymmetric mesoscale convective system (MCS) on 29 June 2011 near the Oklahoma Lightning Mapping Array (LMA). Sprites produced by a total of 26 lightning flashes were observed simultaneously on video from Bennett, Colorado and Hawley, Texas, enabling a triangulation of sprites in comparison with temporal development of parent lightning (in particular, negatively charged stepped leaders) in three‐dimensional space. In general, prompt sprites produced within 20 ms after the causative stroke are less horizontally displaced (typically <30 km) from the ground stroke than delayed sprites, which usually occur over 40 ms after the stroke with significant lateral offsets (>30 km). However, both prompt and delayed sprites are usually centered within 30 km of the geometric center of relevant LMA sources (with affinity to negative stepped leaders) during the prior 100 ms interval. Multiple sprites appearing as dancing/jumping events associated with a single lightning flash could be produced either by distinct strokes of the flash, by a single stroke through a series of current surges superposed on an intense continuing current, or by both. Our observations imply that sprites elongated in one direction are sometimes linked to in‐cloud leader structure with the same elongation, and sprites that were more symmetric were produced above the progression of multiple negative leaders. This suggests that the large‐scale structure of sprites could be affected by the in‐cloud geometry of positive charge removal. Based on an expanded dataset of 39 sprite‐parent flashes by including more sprites recorded by one single camera over the same MCS, the altitude (above mean sea level, MSL) of positively charged cloud region tapped by sprite‐producing strokes declined gradually from ~10 km MSL (−35°C) to around 6 km MSL (−10°C) as the MCS evolved through the mature stage. On average, the positive charge removal by causative strokes of sprites observed on 29 June is centered at 3.6 km above the freezing level or at 7.9 km above ground level.
The fate of early Mars' lost water: The role of serpentinization
Authors: Chassefière Eric , Langlais Benoit , Quesnel Yoann , Leblanc François
Published: May 2013

The fate of water which was present on early Mars remains enigmatic. We propose a simple model based on serpentinization, a hydrothermal alteration process which may produce magnetite and store water. Our model invokes serpentinization during about 500 to 800 Myr, while a dynamo is active, which may have continued after the formation of the crustal dichotomy. We show that the present magnetic field measured by Mars Global Surveyor in the southern hemisphere is consistent with a ~500 m thick Global Equivalent Layer (GEL) of water trapped in serpentine. Serpentinization results in the release of H2. The released H atoms are lost to space through thermal escape, increasing the D/H ratio in water reservoirs exchanging with atmosphere. We show that the value of the D/H ratio in the present atmosphere (~5) is also consistent with the serpentinization of a ~500 m thick water GEL. We reassess the role of nonthermal escape in removing water from the planet. By considering an updated solar wind‐ionosphere interaction representation, we show that the contribution of oxygen escape to H isotopic fractionation is negligible. Our results suggest that significant amounts of water (up to a ~330–1030 m thick GEL) present at the surface during the Noachian, similar to the quantity inferred from the morphological analysis of valley networks, could be stored today in subsurface serpentine.
T1ρ mapping of pediatric epiphyseal and articular cartilage in the knee
Authors: Cobb Jared Guthrie , Kan J. Herman , Gore John C.
Published: May 2013

Purpose

To evaluate the feasibility of measuring T1ρ values in epiphyseal cartilage in children, we have conducted a novel study of spin locking techniques. Adult articular cartilage has been widely studied with spin locking techniques by magnetic resonance imaging. However, no results are available for in vivo T1ρ imaging of developing cartilage.

Materials and Methods

Ten volunteers of age 6 ± 3 years were recruited to have T1ρ mapping performed on the knee at the conclusion of their clinical study. T1ρ maps were generated using a spin‐lock cluster followed by a fast spin‐echo imaging sequence. Regions of interest (ROIs) were placed in non–load‐bearing (NLB), load‐bearing (LB), and articular cartilage.

Results

Student's t‐tests were performed to compare means among the ROIs. Mean T1ρ for epiphyseal and articular cartilage was 49.8 ± 9 and 76.6 ± 7 ms, respectively. LB and NLB T1ρ vales were 47.1 ± 9.5 and 52.5 ± 9 ms, respectively. Significant differences were found in T1ρ values between epiphyseal and articular cartilage layers (P = 0.0001). No difference in T1ρ was observed between NLB and LB layers. A modest trend was also noted for epiphyseal and articular cartilage regions with age.

Conclusion

It is feasible to quantify differences in epiphyseal and articular cartilage layers with SL techniques. T1ρ holds promise as a noninvasive method of studying normal and abnormal developmental states of cartilage in children. J. Magn. Reson. Imaging 2013;38:299–305. © 2012 Wiley Periodicals, Inc.
Assessment of exocrine pancreatic function by secretin‐stimulated magnetic resonance cholangiopancreaticography and diffusion‐weighted imaging in healthy controls
Authors: Wathle Gaute K. , Tjora Erling , Ersland Lars , Dimcevski Georg , Salvesen Øyvind O. , Molven Anders , Njølstad Pål R. , Haldorsen Ingfrid S.
Published: May 2013

Purpose

To characterize and quantify exocrine pancreatic function by secretin‐stimulated magnetic resonance cholangiopancreaticography (s‐MRCP) and diffusion‐weighted imaging (DWI) in healthy subjects and compare these findings to morphological features, ie, pancreatic volume and secretin‐stimulated peak bicarbonate concentration measured in pancreatic juice.

Materials and Methods

Pancreatic magnetic resonance imaging (MRI) (1.5 T) was performed in 20 healthy volunteers among which 10 underwent gastroscopy with duodenal intubation. MRI included T2‐weighted imaging and DWI acquired before and 1, 5, 9, and 13 minutes after secretin administration. Secreted pancreatic juice volumes were calculated based on the sequential T2‐weighted images and pancreatic volumes and apparent diffusion coefficient (ADC) values were estimated.

Results

The mean pancreatic secretion rate declined from 9.5 mL/min at 1–5 minutes (postsecretin) to 2.9 mL/min at 9–13 minutes. Pancreatic head ADC values significantly increased from baseline (1.29 × 10−3 mm2/s) to 1 minute postsecretin (1.48 × 10−3 mm2/s) (P = 0.003). Secreted pancreatic juice volume at 1 minute after secretin correlated positively with peak bicarbonate concentration (n = 10, P = 0.05).

Conclusion

Secretin‐stimulated MRCP and DWI can characterize and quantify exocrine pancreatic function in healthy subjects. These imaging methods may prove relevant for patients with exocrine pancreatic dysfunction. J. Magn. Reson. Imaging 2014;39:448–454. © 2013 Wiley Periodicals, Inc.
Field‐scale potassium and phosphorus fluxes in the bioenergy crop switchgrass: Theoretical energy yields and management implications
Authors: Woodson Patrick , Volenec Jeffrey J. , Brouder Sylvie M.
Published: May 2013

Our understanding of how mineral nutrition affects productivity and composition of bioenergy crops grown on marginal lands remains fragmented and incomplete despite world‐wide interest in using herbaceous biomass as an energy feedstock. Our aim was to determine switchgrass (Panicum virgatum L.) biomass production and maize (Zea mays L.) grain yield on marginal soils used previously to evaluate the effect of soil phosphorus (P) and potassium (K) fertility on alfalfa (Medicago sativa L.) forage production. Grain yield of maize was reduced on P‐ and/or K‐limited plots that also impaired alfalfa forage yield, whereas switchgrass biomass yields were high even in plots possessing very low available P (4 mg kg–1) and K (< 70 mg kg–1) levels. Linear‐plateau regression models effectively described the relationship of soil test P and K to tissue P and K concentrations, and tissue P and K concentrations accurately predicted removal of P and K in harvest biomass. However, neither soil‐test P and K, nor tissue P and K concentrations were effective as diagnostics for predicting switchgrass biomass yield nor could soil tests and their change with cropping predict nutrient removal. Concentrations of cellulose, hemicellulose, lignin, and ash were not influenced by P and K nutrition. Predicted bio‐ethanol production was closely associated with biomass yield whereas high biomass K concentrations reduced estimated bio‐oil production per hectare by as much as 50%. Additional research is needed to identify diagnostics and managements to meet the bioenergy production co‐objectives of having high yield of biomass with very low mineral nutrient concentrations (especially K) while sustaining and improving the fertility of marginal soils.
Effects of uvulopalatopharyngoplasty with or without radiofrequency tongue base reduction on voice in patients with obstructive sleep apnea
Authors: Eun Young Gyu , Shin Seung Youp , Kim Sung Wan
Published: May 2013

Objectives/Hypothesis

To investigate voice change as a complication after uvulopalatopharyngoplasty (UPPP) with or without radiofrequency tongue base reduction (RTBR) in patients with obstructive sleep apnea.

Study Design

Before and after study.

Methods

Twenty‐two patients with suspected velopharyngeal collapse only underwent uvulopalatopharyngoplasty (UPPP group). Twenty‐five patients with velopharyngeal and retrolingual collapse underwent concurrent UPPP with RTBR (RTBR group). All patients were evaluated before surgery and at 8 weeks after surgery. Acoustic measures included mean fundamental frequency (mF0), maximal phonation time (MPT), jitter, shimmer, noise‐to‐harmonic ratio (NHR), hypernasality test, and the first three formant frequencies (F1, F2, F3) for sustained vowels. Voice handicap index (VHI) was used to determine subjective voice change.

Results

Postoperative values for mF0, MPT, jitter, shimmer, NHR, hypernasality test, and F1 did not significantly change in either group following surgery. There were the significant decreases at the F2 of /u/ and the F3 of /o/ in the UPPP group, and at the F2 of /o/ and the F3 of /a/, /i/, and /o/ in the RTBR group. Postoperative VHI score was increased only in the RTBR group.

Conclusions

UPPP and UPPP with RTBR have an impact on formant frequencies of vowels. Despite a relatively small number of patients, it is apparent that UPPP with RTBR influences VHI. Patients, especially professional voice users, should be advised of this before considering the surgery.

Level of Evidence

4
Potential adverse events of endosseous dental implants penetrating the maxillary sinus: Long‐term clinical evaluation
Authors: Najm Semaan Abi , Malis Didier , Hage Marc El , Rahban Sonia , Carrel Jean‐Pierre , Bernard Jean‐Pierre
Published: May 2013

Objectives/Hypothesis

The aim of this study was to evaluate the nature and incidence of long‐term maxillary sinus adverse events related to endosseous implant placement with protrusion into the maxillary sinus.

Study Design

Retrospective cohort study.

Methods

All patients who underwent placement of endosseous dental implants with clinical evidence of implant penetration into the maxillary sinus with membrane perforation were included in this study. Only patients with a minimum follow‐up of 5 years after implant placement were included in this study. Maxillary sinus assessment was both clinical and radiological.

Results

Eighty‐three implants with sinus membrane perforation in 70 patients met the study's inclusion criteria. Mean age was 65.96 years ± 14.23. Twelve patients had more than one implant penetrating the maxillary sinus, and seven of them had bilateral sinus perforation. Estimated implant penetration was ≤3 mm in all cases. The average clinical and radiological follow‐up was 9.98 years ± 3.74 (range 60–243 months). At the follow‐up appointments, there were no clinical or radiological signs of sinusitis in any patient.

Conclusion

This long‐term study, spreading over a period of up to 20 years, indicates that no sinus complication was observed following implant penetration into the maxillary sinus. Furthermore, absence of occurrence of such complications is related to the maintenance of successful osseointegration. A contrario, and in the presence of an acute or chronic maxillary sinusitis, the differential diagnosis must always consider other potential odontogenic and nonodontogenic etiologies.

Level of Evidence

2b. Laryngoscope, 123:2958–2961, 2013
Room Temperature Synthesis of Heptazine‐Based Microporous Polymer Networks as Photocatalysts for Hydrogen Evolution
Authors: Kailasam Kamalakannan , Schmidt Johannes , Bildirir Hakan , Zhang Guigang , Blechert Siegfried , Wang Xinchen , Thomas Arne
Published: May 2013

Two emerging material classes are combined in this work, namely polymeric carbon nitrides and microporous polymer networks. The former, polymeric carbon nitrides, are composed of amine‐bridged heptazine moieties and showed interesting performance as a metal‐free photocatalyst. These materials have, however, to be prepared at high temperatures, making control of their chemical structure difficult. The latter, microporous polymer networks have received increasing interest due to their high surface area, giving rise to interesting applications in gas storage or catalysis. Here, the central building block of carbon nitrides, a functionalized heptazine as monomer, and tecton are used to create microporous polymer networks. The resulting heptazine‐based microporous polymers show high porosity, while their chemical structure resembles the ones of carbon nitrides. The polymers show activity for the photocatalytic production of hydrogen from water, even under visible light illumination.

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Polythioethers by Thiol‐Ene Click Polyaddition of α,ω‐Alkylene Thiols
Authors: Deubel Frank , Bretzler Victor , Holzner Richard , Helbich Tobias , Nuyken Oskar , Rieger Bernhard , Jordan Rainer
Published: May 2013

The straightforward synthesis of a series of poly(thioether)s by photoinduced thiol‐ene click polyaddition of α,ω‐alkylene thiols is reported. It is found that linear and telechelic poly(thioether)s can be directly obtained from α,ω‐alkylene thiols with, for example, alkyl chain length of m = 1,2,3, and 9. The reaction proceeds without additives such as (radical) initiators or metal compounds and can simply be carried out by UV‐irradiation of the bulk monomer or monomer solution. Ex situ kinetic studies reveal that the reaction proceeds by a typical a step‐growth polyaddition mechanism. As the homologue series of poly(thioether)s are now synthetically accessible, new direct pathways to tailored poly(alkyl sulphoxide)s and poly(alkyl sulfone)s are now possible.

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Canomad: report of a case with a 40‐year history and autopsy. Is this a sensory ganglionopathy with neuromuscular junction blockade?
Authors: Mckelvie Penelope A. , Gates Peter C. , Day Timothy
Published: May 2013

Introduction: An 80‐year‐old man had a 40‐year history of chronic sensory ataxic neuropathy and 11 years of relapsing/remitting episodes of rapid deterioration with perioral paresthesiae and weakness of bulbar, respiratory, and limb muscles. Methods: An immunoglobulin M (IgM) paraprotein was detected 12 years before death, and Waldenstrom macroglobulinemia was diagnosed on bone marrow biopsy 3 years before death. Chronic ataxic neuropathy with ophthalmoplegia, IgM paraprotein, cold agglutinins, and anti‐disialyl antibodies (CANOMAD) was diagnosed. Results: Comprehensive autopsy showed severe dorsal column atrophy and dorsal root ganglionopathy. A different pathology was identified in cranial and peripheral nerves, dorsal roots, and cauda equina, comprising infiltration of clonal B‐lymphocytes within the endoneurium, perineurium, and leptomeninges. Conclusions: The autopsy provides evidence of the pathogenesis of the relapsing remitting component of CANOMAD, and we postulate that this may relate to the presence of clonal IgM anti‐disiayl gangliosides secreting B‐lymphocytes within nerves. Muscle Nerve 48: 599–603, 2013
Nonlinear d10‐ML2 Transition‐Metal Complexes
Authors: Wolters Lando P. , Bickelhaupt F. Matthias
Published: May 2013

We have investigated the molecular geometries of a series of dicoordinated d10‐transition‐metal complexes ML2 (M=Co−, Rh−, Ir−, Ni, Pd, Pt, Cu+, Ag+, Au+; L=NH3, PH3, CO) using relativistic density functional theory (DFT) at ZORA‐BLYP/TZ2P. Not all complexes have the expected linear ligand–metal–ligand (LML) angle: this angle varies from 180° to 128.6° as a function of the metal as well as the ligands. Our main objective is to present a detailed explanation why ML2 complexes can become bent. To this end, we have analyzed the bonding mechanism in ML2 as a function of the LML angle using quantitative Kohn–Sham molecular orbital (MO) theory in combination with an energy decomposition analysis (EDA) scheme. The origin of bent LML structures is π backdonation. In situations of strong π backdonation, smaller angles increase the overlap of the ligand’s acceptor orbital with a higher‐energy donor orbital on the metal‐ligand fragment, and therefore favor π backdonation, resulting in additional stabilization. The angle of the complexes thus depends on the balance between this additional stabilization and increased steric repulsion that occurs as the complexes are bent.
Theoretical studies on [2 + 2 + 2] reaction mechanisms of three ethynes. More accurate estimation of activation energy
Authors: Sakai Shogo , Udagawa Taro , Kato Shohei , Nakada Keita
Published: May 2013

The mechanisms of the [2 + 2 + 2] cycloaddition reaction of three ethyne molecules were studied by ab initio molecular orbital and density functional methods. The transition states range from that of the concerted mechanism with D3h symmetry to that of the stepwise mechanism with C2 symmetry. The transition state structure and the activation energy depend on the basis set and computational method employed in the analysis. The activation energy barrier was determined to be in the range of 36–44 kcal/mol. The activation energy determined by various methods corresponds to the interaction energy, which is related to the electron correlation energy. The best estimation of the activation energy barrier is 41.6 kcal/mol, achieved from the relation between the interaction energy and the activation energy. Copyright © 2013 John Wiley & Sons, Ltd.
Thin film formation of EuGa2S4 by rf sputtering and improvement of film transmittance
Authors: Dohi Minoru
Published: May 2013

EuxCa1–xGa2S4 is one of the phosphors with high luminescence quantum efficiency. It has high optical gain due to less concentration quenching for Eu centre. Production of EuGa2S4 film with smooth surface would lead to a possible construction of surface emitting lasers. We prepared films by sputtering with EuGa2S4 target. The EuGa2S4 films deposited on the substrates heated at 550–640 °C had the surfaces smoother than that of films post‐annealed at 800–900 °C. The Eu3Ga5O12 films were deposited on the substrates heated at 660–800 °C. The Eu3Ga5O12 films, which were transparent and colourless, showed no photoluminescence and had smooth surfaces. The films were deposited on the cooled substrate for 30 min and sequentially deposited on the substrate heated at 640–700 °C for 10–30 min. The films, which consisted of two layers, EuGa2S4 and Eu3Ga5O12, show high transmittances and exhibited yellow green emission. The films have the possibility to be applied to the laser. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
XPS depth profile study of CZTS thin films prepared by spray pyrolysis
Authors: Aono Masami , Yoshitake Koichiro , Miyazaki Hisashi
Published: May 2013

Uniformity of elements distribution in Cu2ZnSnS4 (CZTS) thin films were analyzed using X‐ray photoelectron spectroscopy (XPS) to improve of conversion efficiency on solar cells. The films were prepared from CuCl or CuCl2, ZnCl2, SnCl2, and thiourea by spray pyrolysis on quartz glass. The composition on surfaces of the as‐grown CZTS films was Cu‐poor and near stoichiometric compositions of Zn, Sn and S. In contrast to the surface, Cu‐rich and Sn‐poor compositions were obtained in the films. An existence of oxygen was observed on the film surface less than 20 nm. With increasing of thiourea concentration in the precursor, internal Cu composition, Cu/(Sn+Zn), was increased. S/metal ratio and Sn/Zn ratio in the films were less influenced by the thiourea concentration in the precursor solution. Cupper composition in the films was also affected a valence of Cu ion in the precursor. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication of Cu2ZnSnSe4 thin films from an electrodeposited Cu‐Zn‐Sn‐Se/Cu‐Sn‐Se bilayer
Authors: Septina Wilman , Ikeda Shigeru , Harada Takashi , Matsumura Michio
Published: May 2013

In this study, a novel sequential electrodeposition of Cu‐Zn‐Sn‐Se and Cu‐Sn‐Se layers was applied for fabrication of a Cu2ZnSnSe4 (CZTSe) thin film. The desired Cu‐Zn‐Sn‐Se/Cu‐Sn‐Se bilayer was obtained at a selected applied potential from electrolytes containing corresponding metal and selenium ions. Annealing of the bilayer film under argon (Ar) flow induced significant losses of Sn and Se components due probably to evaporation of the SnSe compound. Suppression of these losses could be realized by introduction of Se vapor during the annealing: as a result, a CZTSe thin film with an ideal Cu‐poor/Zn‐rich composition for solar cell application was obtained. The solar cell with a device with the structure of glass/Mo/CZTSe/CdS/ZnO/AZO derived from thus‐obtained CZTSe film exhibited a conversion efficiency of 1.1%, while the device still possessed a significant leakage current and a high series resistance. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Structure and optical properties of CdS:O thin films
Authors: Asaba Ryo , Wakita Kazuki , Kitano Atsushi , Shim YongGu , Mamedov Nazim , Bayramov Ayaz , Huseynov Emil , Hasanov Ilham
Published: May 2013

We have studied structure and optical properties of CdS:O thin films deposited on soda lime glass substrates by rf magnetron sputtering in the atmosphere of oxygen/argon gases. According to X‐ray diffraction and confocal Raman scattering data, the films deposited under oxygen partial pressure below 3% show crystalline structure of CdS. On the other hand, X‐ray diffraction, confocal Raman scattering, TEM (transmission electron microscopy) and XPS (X‐ray photoelectron spectroscopy) data are indicative of amorphization, nano‐crystallization, and inclusion of CdO2 in CdS:O thin films obtained under oxygen partial pressure of 5%. The last films have shown significantly increased transmittance in a spectral range above the energy gap of CdS. The origin of this transmittance is discussed by taking into account redistribution of electronic density‐of‐states in amorphous phase, quantum size effect and contribution of CdO2. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Growth and characterization of ZnS films by spray pyrolysis
Authors: Tokuda Takahiro , Yoshino Kenji
Published: May 2013

ZnS films are formed by spray method using various zinc sources such as zinc acetate (Zn(CH3COO)2), zinc sulfate (ZnSO4), zinc nitrate (Zn(NO3)2), zinc iodide (ZnI2), zinc chloride (ZnCl2), zinc acetyl (Zn(acac)2). ZnS film using zinc iodide is sharp spectrum and zinc sulfate is broad spectrum by X‐ray diffraction (XRD). The XRD spectra indicates that ZnS using zinc chloride and zinc iodide at 100 °C the source of zinc to zinc acetate and zinc nitrate at 200 °C, zinc acetyl at 300 °C, zinc sulfate at 400 °C can be confirmed. These results are consistent with the difference in the instability constants of each zinc source. The ionization of Zn becomes difficult with increasing the instability constant of zinc sources. Reaction is slow due to low ionized zinc in solution. Therefore, it is considered that ZnS films are hard to crystallize at low substrate temperature. The grain size becomes large with decreasing the instability constant. It is considered that this is proportional to the amount of zinc ions in solution. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman spectra of wurtzstannite quaternary compounds
Authors: Guc Maxim , Izquierdo‐Roca Victor , Pérez Rodríguez Alejandro , Gurieva Galina , Levcenko Serghei , Schorr Susan , Arushanov Ernest
Published: May 2013

Wurtzstannite‐type Cu2ZnGeS4, Cu2ZnSiSe4 and Cu2ZnSiS4 single crystals were grown by chemical vapor transport method using iodine as transport agent. Raman spectra of obtained crystals were investigated and 17, 11 and 18 peaks were observed for Cu2ZnGeS4, Cu2ZnSiSe4 and Cu2ZnSiS4, respectively. In all cases, the spectra from these compounds are characterized by three dominant peaks. In case of Cu2ZnSiSe4 the dominant peaks appear at 222 cm–1, 179 cm–1 and 170 cm–1. For Cu2ZnGeS4 and Cu2ZnSiS4 the most intense peak shifts from 360 cm–1 to 393 cm–1 with replacement of Ge by Si, while the other main peaks have almost the same position for both compounds (272–278 cm–1 and 291 cm–1). Identification of these dominant peaks provides with a characteristic spectral fingerprint for detection of these crystalline phases. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Serological cross‐reactivity between human polyomaviruses
Authors: Moens Ugo , Van Ghelue Marijke , Song Xiaobo , Ehlers Bernhard
Published: May 2013

Until 2006, BKPyV and JCPyV were the only known human polyomaviruses. A third polyomavirus, simian virus 40 whose natural host is the macaque was accidently introduced into man because of contaminated poliovirus vaccines, although there is epidemiological evidence that SV40 may be transmitted between man independently from contaminated vaccines. Since 2007, 10 new human polyomaviruses have been identified: KIPyV, WUPyV, Merkel cell polyomavirus, trichodysplasia spinulosa‐associated polyomavirus, and human polyomaviruses 6, 7, 9, 10, STL, and 12. Moreover, the DNA of the monkey lymphotropic polyomavirus has been amplified from human peripheral blood. Seroepidemiological studies frequently based on the presence of antibodies against the major capsid protein VP1 or virus‐like particles indicate that most human adults have been exposed to many, if not all, human polyomaviruses. However, because of the high amino acid sequence identity between VP1 of some human polyomaviruses, cross‐reactivity of antibodies is occasionally observed. In addition, human sera possess reactivity against VP1 of polyomaviruses from other species, suggesting serological cross‐reaction with known or closely related, yet unidentified human polyomaviruses and/or the possibility of zoonotic transmission. Thus, current serological results should be interpreted with caution, and controls excluding cross‐reactivity with other polyomaviruses are required. Copyright © 2013 John Wiley & Sons, Ltd.
Self‐Assembled Peptide–Polyoxometalate Hybrid Nanospheres: Two in One Enhances Targeted Inhibition of Amyloid β‐Peptide Aggregation Associated with Alzheimer's Disease
Authors: Li Meng , Xu Can , Wu Li , Ren Jinsong , Wang Enbo , Qu Xiaogang
Published: May 2013

Amyloid fibril formation is a critical step in Alzheimer's disease (AD) pathogenesis. Inhibition of Aβ aggregation has shown promising against AD and has been used in clinic trials. Here, a novel strategy is reported for the self‐assembly of polyoxometalate–peptide (POM@P) hybrid particles as bifunctional Aβ inhibitors. The two‐in‐one bifunctional POM@P nanoparticles show an enhanced inhibition effect on amyloid aggregation in mice cerebrospinal fluid. Incorporating a clinically used Aβ fibril‐staining dye, congo red (CR), into the hybrid colloidal spheres, the nanoparticles can also act as an effective fluorescent probe to monitor the inhibition process of POM@P via CR fluorescence change in real time. It is believed that such flexible organic–inorganic hybrid systems may prompt the design of new multifunctional materials for AD treatment.
Multiwall Carbon Nanotubes Mediate Macrophage Activation and Promote Pulmonary Fibrosis Through TGF‐β/Smad Signaling Pathway
Authors: Wang Peng , Nie Xin , Wang Yue , Li Yang , Ge Cuicui , Zhang Lili , Wang Liming , Bai Ru , Chen Zhiyun , Zhao Yuliang , Chen Chunying
Published: May 2013

Multiwall carbon nanotubes (MWCNTs) have been widely used in many disciplines due to their unique physical and chemical properties, but have also raised great concerns about their possible negative health impacts, especially through occupational exposure. Although recent studies have demonstrated that MWCNTs induce granuloma formation and/or fibrotic responses in the lungs of rats or mice, their cellular and molecular mechanisms remain largely unaddressed. Here, it is reported that the TGF‐β/Smad signaling pathway can be activated by MWCNTs and play a critical role in MWCNT‐induced pulmonary fibrosis. Firstly, in vivo data show that spontaneously hypertensive (SH) rats administered long MWCNTs (20–50 μm) but not short MWCNTs (0.5–2 μm) exhibit increased fibroblast proliferation, collagen deposition and granuloma formation in lung tissue. Secondly, the in vivo experiments also indicate that only long MWCNTs can significantly activate macrophages and increase the production of transforming growth factor (TGF)‐β1, which induces the phosphorylation of Smad2 and then the expression of collagen I/III and extracellular matrix (ECM) protease inhibitors in lung tissues. Finally, the present in vitro studies further demonstrate that the TGF‐β/Smad signaling pathway is indeed necessary for the expression of collagen III in fibroblast cells. Together, these data demonstrate that MWCNTs stimulate pulmonary fibrotic responses such as fibroblast proliferation and collagen deposition in a TGF‐β/Smad‐dependent manner. These observations also suggest that tube length acts as an important factor in MWCNT‐induced macrophage activation and subsequent TGF‐β1 secretion. These in vivo and in vitro studies further highlight the potential adverse health effects that may occur following MWCNT exposure and provide a better understanding of the cellular and molecular mechanisms by which MWCNTs induce pulmonary fibrotic reactions.
Using Argument as a Tool for Integrating Science and Literacy
Authors: Washburn Erin , Cavagnetto Andy
Published: May 2013

The integration of literacy in science education has been supported by both literacy and science researchers and educators. Recent federal initiatives such as the Common Core State Standards and A Framework for K‐12 Science Education have also emphasized the need to integrate literacy and science. However, few tools exist to help educators think about how to integrate best literacy practices into their science lessons. PONG Cycles is an argument‐to‐learn framework for teaching and learning science that can be used to integrate all aspects of literacy (speaking, listening, reading, writing and viewing). An explanation of PONG Cycles, along with implications and suggestions for its use in the upper elementary classroom, is provided.
Biometry of the fetal corpus callosum by three‐dimensional ultrasound
Authors: Pashaj S. , Merz E. , Wellek S.
Published: May 2013

Objectives

To construct reference ranges of quantitative characteristics of the fetal corpus callosum.

Methods

Women referred to a tertiary center for sonographic examination were recruited to undergo a detailed fetal scan from 17 to 41 weeks of gestation. Three‐dimensional (3D) sonographic volumes of normal fetal brains were acquired and analyzed offline. We obtained three different measurements of the corpus callosal length, as well as the height (/thickness) of its segments, namely the rostrum, genu, body and splenium.

Results

Initially we recruited 604 pregnant women, of whom 138 were excluded because of various disorders/abnormalities, multiple pregnancy or gestational age < 18 weeks. Thus, included in the analysis were 466 sonographic volumes of normal fetal brains from singleton pregnancies, acquired by transabdominal ( n = 170) or transvaginal (n = 296) ultrasound. The corpus callosum was visualized as a hypoechoic structure. Reference ranges were established for the following parameters: curved corpus callosal length, inner–inner corpus callosal length, outer–outer corpus callosal length, rostrum height, genu height, body height and splenium height. We observed non‐linear growth and an approximately four‐fold increase in all corpus callosal lengths, a three‐fold increase in rostrum height, a four‐fold increase in genu height, a two‐fold increase in body height and a three‐fold increase in splenium height between 18 and 41 weeks. The growth patterns of rostrum and body height appeared to be similar: there was rapid development until 24 and 22 weeks of gestation, respectively, and growth slowed beyond this period. The growth patterns of genu and splenium were also similar, being characterized by progressive growth throughout gestation.

Conclusions

Using 3D ultrasound, we have constructed reference charts for measurements of the corpus callosum. Knowledge of the normal growth pattern may be useful for evaluation of abnormal development of the corpus callosum, and so help in the accurate diagnosis of pathologies such as hypogenesis and dysgenesis. Copyright © 2013 ISUOG. Published by John Wiley & Sons Ltd.
Estimating Escherichia coli loads in streams based on various physical, chemical, and biological factors
Authors: Dwivedi Dipankar , Mohanty Binayak P. , Lesikar Bruce J.
Published: May 2013

Key Points

A BNN scheme is presented for estimating E. coli loads in streams

E. coli load estimations by the BNN model are better than by the LOADEST model

Physical, chemical, and biological factors are important for E‐coli load
Advection around ventilated U‐shaped burrows: A model study
Authors: Brand Andreas , Lewandowski Jörg , Hamann Enrico , Nützmann Gunnar
Published: May 2013

Key Points

Advection occurs in sediments populated by organisms living in open ended tubes.

The effects of advection compensate each other with respect to total fluxes.

Advection can define a distinct microenvironment in the sediment.
Effects of Epoxidation and Nitration on Ballistic Properties of FOX‐7 – A DFT Study
Authors: Türker Lemi , Varış Serhat
Published: May 2013

1, 1‐Diamino‐2, 2‐dinitroethylene (FOX‐7) has received increasing attention since it was industrialized in the late 1990s. It has lower sensitivity and comparable performance to RDX. This paper presents ballistic properties of FOX‐7, its mono and dinitro derivatives and their epoxide derivatives computationally. The structures were optimized at the B3LYP/6‐31G(d, p) level and the bond lengths were calculated. The calculated data for FOX‐7 are compatible with the literature one. We have investigated the bond dissociation energies of the molecules. Mulliken electro negativities (χM) and chemical hardness (η) were reviewed using Frontier Molecular Orbitals at HF/6‐31G(d, p)//B3LYP/6‐31G(d, p) theoretical level. The detonation performance analyses were done using empirical Kamlet‐Jacobs equations. Additionally, power index values were calculated. All the compounds considered in the present article are powerful candidates for high energy materials.
Lifting degeneracies in Higgs couplings using single top production in association with a Higgs boson
Authors: Farina Marco , Grojean Christophe , Maltoni Fabio , Salvioni Ennio , Thamm Andrea
Published: May 2013

Abstract

Current Higgs data show an ambiguity in the value of the Yukawa couplings to quarks and leptons. Not so much because of still large uncertainties in the measurements but as the result of several almost degenerate minima in the coupling profile likelihood function. To break these degeneracies, it is important to identify and measure processes where the Higgs coupling to fermions interferes with other coupling(s). The most prominent example, the decay of h → γγ, is not sufficient to give a definitive answer. In this paper, we argue that t-channel single top production in association with a Higgs boson, with h → bb, can provide the necessary information to lift the remaining degeneracy in the top Yukawa. Within the Standard Model, the total rate is highly reduced due to an almost perfect destructive interference in the hard process, W b → th. We first show that for non-standard couplings the cross section can be reliably computed without worrying about corrections from physics beyond the cutoff scale Λ ≳ 10 TeV, and that it can be enhanced by more than one order of magnitude compared to the SM. We then study the signal pp → thj(b) with 3 and 4 b’s in the final state, and its main backgrounds at the LHC. We find the 8 TeV run dataset to be sensitive to the sign of the anomalous top Yukawa coupling, while already a moderate integrated luminosity at 14 TeV should lift the degeneracy completely.
Induction Chemotherapy or Chemoradiotherapy Followed by Radical Esophagectomy for T4 Esophageal Cancer: Results of a Prospective Cohort Study
Authors: Shimoji Hideaki , Karimata Hiroyuki , Nagahama Masayoshi , Nishimaki Tadashi
Published: May 2013

Background

We hypothesized that the survival rate of patients undergoing R0 esophagectomy after induction chemotherapy or chemoradiotherapy for unresectable T4 esophageal cancer (URT4) would be similar to that of patients undergoing esophagectomy for immediately resectable esophageal cancer with no unfavorable prognostic factors (RNU).

Methods

Between April 2002 and June 2012, 87 of 283 patients with esophageal cancer who presented at the University Hospital of the Ryukyus were enrolled in this prospective cohort study. Tumors were classified as RNU and URT4 in 44 and 43 of the 87 patients, respectively. Outcomes of treatment for URT4 patients were compared with those of RNU patients.

Results

The R0 resection rate (61 %) and in‐hospital mortality rate (20 %) of URT4 patients were significantly poorer than those of RNU patients (98 and 2.3 %, respectively), although the morbidity rate was similar in the two groups (63 and 52 %, respectively). The 5‐year survival rate (35 %) of URT4 patients was significantly poorer than that of RNU patients (67 %) in the intention‐to‐treat analysis. However, no significant difference was noted between the two survival curves for cases of R0 resection (5‐year survival rate, 60 % vs. 69 %). Multivariate analysis revealed R status as the only significant independent prognostic factor for URT4 patients (P < 0.001; hazard ratio = 8.279).

Conclusions

Satisfactory survival rates can be achieved if R0 resection is performed after induction treatment in patients with T4 esophageal cancer, although secondary radical esophagectomy is associated with a higher risk of in‐hospital mortality.
Evaluation of Office Ultrasound Usage among Australian and New Zealand Breast Surgeons
Authors: Law Michael T. , Kollias James , Bennett Ian
Published: May 2013

Background

Surgeon performed ultrasound (US) is being increasingly embraced by breast surgeons worldwide as an integral part of patient assessment. The extent of its application within Australia and New Zealand is not well documented. The present study aimed to evaluate its current usage patterns and to determine suitable future training models.

Methods

An online survey was sent to members of Breast Surgeons of Australia and New Zealand (BreastSurgANZ) between July and September 2010, with emphases on practice demographics, access to US equipment, usage, biopsy patterns, and training.

Results

Of the 126 surveys sent, 59 were returned. The majority of respondents were metropolitan based (64 %), worked in both public and private sectors (71 %), and practiced endocrine or general surgery (85 %), as well as breast surgery. A preponderance of surgeons had access to equipment (63 %), performed at least 1 US monthly (63 %), but did not perform regular guided biopsies. Rural practice did not affect access or usage patterns. Most respondents underwent structured US training (73 %), which was associated with greater US and biopsy usage, biopsy complexity, intraoperative applications, and cross discipline applications (p < 0.03). Most surgeons favored a structured training program for future trainees (83 %).

Conclusions

The majority of breast surgeons from Australia and New Zealand have adopted office US to varying degrees. Geographic variation did not lead to access inequity and variation in scanning patterns. Formal US training may result in a wider scope of clinical applications by increasing operator confidence and is the preferred model within a specialist breast surgical curriculum.
Prescribing of Sick Leave by Surgeons: A Survey Based on Hypothetical Patient Cases
Authors: Kankaanpää Anni T. , Laato Matti K. , Tuominen Risto J.
Published: May 2013

Background

Physicians regard the tasks of sick‐listing and work ability assessments problematic and among the most challenging duties in their practice. Few studies have analyzed sick leave prescribing practices, and the practices have been shown to vary among physicians. The aim of this study was to examine the prescribing of sick leave by surgeons and factors that affect these prescribing practices.

Methods

A questionnaire study with 19 hypothetical patient cases was conducted among 338 Finnish surgeons. The effects of both physician‐related and local structural background variables on sick leave prescribing were studied using univariate and multiple linear regression models. The economic consequences of the variation in sick leave prescribing were estimated.

Results

The overall number of days of sick leave prescribed for the entire group of 19 patient cases averaged 281.4 days (range = 134–490 days). With the same diagnosis, surgeons prescribed more days of sick leave for patients who do physical work than for those who work in an office. Older surgeons with more working experience and those working in smaller municipalities or in smaller hospitals prescribed longer sick leave than others. Clinical specialists tended to prescribe longer sick leave than those still in specialty training.

Conclusion

Structured education for surgeons on prescribing sick leave, together with defined guidelines, could produce more uniform practices and improve equality among patients.
Gene replacement and elimination using λRed- and FLP-based tool to re-direct carbon flux in acetogen biocatalyst during continuous CO2/H2 blend fermentation
Authors: Tyurin Michael
Published: May 2013

A time- and cost-efficient two-step gene elimination procedure was used for acetogen Clostridium sp. MT1834 capable of fermenting CO2/H2 blend to 245 mM acetate (p < 0.005). The first step rendered the targeted gene replacement without affecting the total genome size. We replaced the acetate pta-ack cluster with synthetic bi-functional acetaldehyde-alcohol dehydrogenase (al-adh). Replacement of pta-ack with al-adh rendered initiation of 243 mM ethanol accumulation at the expense of acetate production during CO2/H2 blend continuous fermentation (p < 0.005). At the second step, al-adh was eliminated to reduce the genome size. Resulting recombinants accumulated 25 mM mevalonate in fermentation broth (p < 0.005). Cell duplication time for recombinants with reduced genome size decreased by 9.5 % compared to Clostridium sp. MT1834 strain under the same fermentation conditions suggesting better cell energy pool management in the absence of the ack-pta gene cluster in the engineered biocatalyst. If the first gene elimination step was used alone for spo0A gene replacement with two copies of synthetic formate dehydrogenase in recombinants with a shortened genome, mevalonate production was replaced with 76.5 mM formate production in a single step continuous CO2/H2 blend fermentation (p < 0.005) with cell duplication time almost nearing that of the wild strain.
Retracted: MiR‐365b‐3p, down‐regulated in retinoblastoma, regulates cell cycle progression and apoptosis of human retinoblastoma cells by targeting PAX6
Authors: Wang Jianwen , Wang Xiaochun , Wu Guiling , Hou Dingshan , Hu Qi
Published: May 2013

PAX6 contributes to the development and progression of retinoblastoma (RB), but the molecular mechanism underlying the regulation of PAX6 expression is unclear. Here we found that microRNA‐365b‐3p (miR‐365b‐3p) is downregulated in human RB tissues. Ectopic expression of miR‐365b‐3p significantly attenuates cell growth, induces cell cycle arrest in G1 phase and cell apoptosis through inhibiting the expression of PAX6 by directly binding its 3′ untranslated regions. Furthermore, overexpression of miR‐365b‐3p upregulates p21 and p27 but downregulates cdc2 and Cyclin D1 protein levels. Elucidating the regulatory mechanism of PAX6 by microRNAs may give new clues to the therapy against RB.
Reflections on Clinical Practice in Pediatric Psychology and Implications for the Field
Authors: Drotar Dennis
Published: May 2013

The clinical practice of pediatric psychology raises compelling challenges, such as managing the tension between diagnostic labels and human experience; communication among children, parents, and pediatric health care providers in health care systems; interprofessional relationships; managing complex, multifaceted clinical problems; and professional values (e.g., interprofessional tensions, patient advocacy, and ethics). Lessons learned in managing these challenges are identified, and implications for clinical practice, integration of research and practice, and training are considered.
Assessment of the Holland model for silicon phonon-phonon relaxation times using lattice dynamics calculations
Authors: Zhu Zimu , Romero David A. , Sellan Daniel P. , Nabovati Aydin , Amon Cristina H.
Published: May 2013

We assess the ability of the Holland model to accurately predict phonon-phonon relaxation times from bulk thermal conductivity values. First, lattice dynamics calculations are used to obtain phonon-phonon relaxation times and thermal conductivities for temperatures ranging from 10 K to 1000 K for Stillinger-Weber silicon. The Holland model is then fitted to these thermal conductivities and used to predict relaxation times, which are compared to the relaxation times obtained by lattice dynamics calculations. We find that fitting the Holland model to both total and mode-dependent thermal conductivities does not result in accurate mode-dependent phonon-phonon relaxation times. Introduction of Umklapp scattering for longitudinal modes resulted in improved prediction of mode-dependent relative contributions to thermal conductivity, especially at high temperatures. However, assumptions made by Holland regarding the frequency-dependence of phonon scattering mechanisms are found to be inconsistent with lattice dynamics data. Instead, we introduce a simple method based on using cumulative thermal conductivity functions to obtain better predictions of the frequency-dependence of relaxation times.
Disruption avoidance in the SINP-Tokamak by means of electrode-biasing at the plasma edge
Authors: Basu Debjyoti , Pal Rabindranath , Martinell Julio J. , Ghosh Joydeep , Chattopadhyay Prabal K.
Published: May 2013

Control of plasma disruption by a biased edge electrode is reported in SINP-Tokamak. The features that characterize a plasma disruption are reduced with increasing bias potential. The disruption can be completely suppressed with the concomitant stabilization of observed MHD modes that are allegedly precursors of the disruption. An m = 3/n = 1 tearing mode, which apparently causes disruption can be stabilized when a negative biasing potential is applied near the edge. These changes in the disruptive behavior with edge biasing are hypothesized to be due to changes in the current density profile.