bluuebunny/crossref_metadata_2025 huggingface dataset:
A new method for determination of hyaluronidase activity in biological samples using capillary zone electrophoresis
Authors: Matysiak Jan , Dereziński Paweł , Urbaniak Bartosz , Klupczyńska Agnieszka , Zalewska Anna , Kokot Zenon J.
Published: April 2013

The aim of the study was to develop a new capillary zone electrophoresis (CZE) method for determination of enzymatic activity of hyaluronidase. The method permits monitoring of the process of hyaluronic acid digestion by hyaluronidase. Studies were performed using CZE instrument equipped with capillary of 64.5 cm total length, 56 cm effective length and internal diameter 75 µm. Separation was performed in the phosphate buffer (pH 8.10) in the electric field of 20 kV, λ = 220 nm. The procedure was based on mixing a known quantity of hyaluronic acid and an aliquot of hyaluronidase solution, followed by obtaining CZE profiles after a known period of incubation (0.5 h). The activity of hyaluronidase was calculated using multiple regression analysis in which sizes of the peaks of the main degradation products were used. The newly developed method was fully validated and it is appropriate to evaluate the activity of hyaluronidase originating from different sources with high precision and accuracy. t‐Tests showed that there were no significant differences between results obtained using turbidimetric, viscosimetric and the new CZE method. The developed method is characterized by a short duration of analysis, low volume of analyzed sample, small amount of buffers used and low cost of analysis. Copyright © 2013 John Wiley & Sons, Ltd.
Impact of Concomitant Coronary Artery Disease on Atherosclerotic Plaques in the Aortic Arch in Patients With Severe Aortic Stenosis
Authors: Fujita Suwako , Sugioka Kenichi , Matsumura Yoshiki , Ito Asahiro , Hozumi Takeshi , Hasegawa Takao , Hanatani Akihisa , Naruko Takahiko , Ueda Makiko , Yoshiyama Minoru
Published: April 2013

Background

Coronary artery disease (CAD) often occurs concurrently in patients with severe aortic stenosis (AS). However, the influence of concomitant CAD on the presence of atherosclerotic complex plaques in the aortic arch, which is associated with increased stroke risk, has not been fully assessed in patients with severe AS.

Hypothesis

We hypothesized that concomitant CAD would be associated with the presence of complex arch plaques in patients with severe AS.

Methods

The study population consisted of 154 patients with severe AS who had undergone transesophageal echocardiography (TEE) and coronary angiography (71 male; mean age, 72 ± 8 years; mean aortic valve area, 0.67 ± 0.15 cm2). Aortic arch plaques were assessed using TEE, and complex arch plaques were defined as large plaques (≥4 mm), ulcerated plaques, or mobile plaques.

Results

The prevalence of aortic arch plaques (87% vs 70%; P = 0.03) and complex arch plaques (48% vs 20%; P < 0.001) was significantly greater in AS patients with CAD than in those without CAD. After adjustment for traditional atherosclerotic risk factors, we found that concomitant CAD was independently associated with the presence of complex arch plaques (odds ratio: 2.86, 95% confidence interval: 1.23‐6.68, P = 0.01).

Conclusions

In patients with severe AS, concomitant CAD is associated with severe atherosclerotic burden in the aortic arch. This observation suggests that AS patients with concomitant CAD are at a higher risk for stroke, and that careful evaluation of complex arch plaques by TEE is needed for the risk stratification of stroke in these patients.
Fluorescence microscopy—A historical and technical perspective
Authors: Renz Malte
Published: April 2013

For a little more than a century, fluorescence microscopy has been an essential source of major discoveries in cell biology. Recent developments improved both visualization and quantification by fluorescence microscopy imaging and established a methodology of fluorescence microscopy. By outlining basic principles and their historical development, I seek to provide insight into and understanding of the ever‐growing tools of fluorescence microscopy. Thereby, this synopsis may help the interested researcher to choose a fluorescence microscopic method capable of addressing a specific scientific question. © 2013 International Society for Advancement of Cytometry
D‐Glucuronic Acid Coated Gd(IO3)3·2H2O Nanomaterial as a Potential T1 MRI‐CT Dual Contrast Agent
Authors: Lee Eun Jung , Heo Woo Choul , Park Jang Woo , Chang Yongmin , Bae Ji‐Eun , Chae Kwon Seok , Kim Tae Jeong , Park Ji Ae , Lee Gang Ho
Published: April 2013

To date, only a few nanosystems have been investigated as T1 MRI‐CT dual contrast agents. The T1 MRI‐CT dual functionality of a material depends on its longitudinal water‐proton relaxivity (r1) and X‐ray absorption strength. We explored Gd(IO3)3·2H2O nanomaterial because Gd is the most powerful element for T1 MRI contrast agents, and both Gd and I absorb X‐ray radiation; Gd absorbs X‐ray radiation ca. 2.5 times more strongly than I. D‐Glucuronic acid coated Gd(IO3)3·2H2O nanomaterial showed a very large r1 of 52.3 s–1 mM–1 (r2/r1 = 1.21), which could be ascribed to hydrated water molecules in the lattice. Its X‐ray absorption intensity was also stronger than those of commercial molecular iodine CT contrast agents. This result clearly suggests that D‐glucuronic acid coated Gd(IO3)3·2H2O nanomaterial is a potential T1 MRI‐CT dual contrast agent.
Europium Polyoxometalates Encapsulated in Silica Nanoparticles – Characterization and Photoluminescence Studies
Authors: Neves Cristina S. , Granadeiro Carlos M. , Cunha‐Silva Luís , Ananias Duarte , Gago Sandra , Feio Gabriel , Carvalho Patricia A. , Eaton Peter , Balula Salete S. , Pereira Eulália
Published: April 2013

The incorporation of europium polyoxometalates into silica nanoparticles can lead to a biocompatible nanomaterial with luminescent properties suitable for applications in biosensors, biological probes, and imaging. Keggin‐type europium polyoxometalates Eu(PW11)x (x = 1 and 2) with different europium coordination environments were prepared by using simple methodologies and no expensive reactants. These luminescent compounds were then encapsulated into silica nanoparticles for the first time through the water‐in‐oil microemulsion methodology with a nonionic surfactant. The europium polyoxometalates and the nanoparticles were characterized by using several techniques [FTIR, FT‐Raman, 31P magic angle spinning (MAS) NMR, and TEM/energy‐dispersive X‐ray spectroscopy (TEM‐EDS), AFM, dynamic light scattering (DLS), and inductively coupled plasma MS (ICP‐MS) analysis]. The stability of the material and the integrity of the europium compounds incorporated were also examined. Furthermore, the photoluminescence properties of the Eu(PW11)x@SiO2 nanomaterials were evaluated and compared with those of the free europium polyoxometalates. The silica surface of the most stable nanoparticles was successfully functionalized with appropriate organosilanes to enable the covalent binding of oligonucleotides.
Preparation and physicochemical performances of poly[(vinylidene fluoride)‐co‐hexafluoropropylene]‐based composite polymer electrolytes doped with modified carbon nanotubes
Authors: Xiao Wei , Li Xinhai , Guo Huajun , Wang Zhixing , Li Yan , Yang Bo
Published: April 2013

Modified carbon nanotubes (m‐CNTs) were successfully prepared by the interactions between nitric and sulfuric acids and CNTs, which was confirmed using Fourier transform infrared spectroscopy. Poly[(vinylidene fluoride)‐co‐hexafluoropropylene]‐based composite polymer electrolyte (CPE) membranes doped with various amounts of m‐CNTs were prepared by phase inversion method. The desired CPEs were obtained by soaking the liquid electrolytes for 30 min. The physicochemical and electrochemical properties of the CPE membranes were investigated using scanning electron microscopy, X‐ray diffraction, thermogravimetry, electrochemical impedance spectroscopy and linear sweep voltammetry. The results show that the CPE membranes doped with 2.2 wt% m‐CNTs possess the smoothest surface and the highest decomposition temperature about 450 °C. Obviously, adding an appropriate amount of m‐CNTs into the polymer matrix can decrease the crystallinity and enhance the ionic conductivity; the temperature dependence of ionic conductivity follows the Arrhenius relation and the ionic conductivity at room temperature is up to 4.9 mS cm−1. The interfacial resistance can reach a stable value of about 415 Ω cm−2 after 10 days storage. The excellent rate and cycle performances with an electrochemical working window up to 5.4 V ensure that the CPEs doped with 2.2 wt% m‐CNTs can be considered as potential candidates as polymer electrolyte for lithium ion batteries. © 2013 Society of Chemical Industry
Simulation reveals two major docking pathways between the hexapeptide GDYMNM and the catalytic domain of the insulin receptor protein kinase
Authors: Huang Zunnan , Wong Chung F.
Published: April 2013

Extending a previous mining‐minima approach to identifying the docking pathways between the hexapeptide GDYMNM and the catalytic domain of the insulin receptor tyrosine kinase (IRK), we found two major docking pathways connecting the binding pocket and the surface of the protein. One pathway was more likely to lead to phosphate transfer from ATP to the peptide as the distance between the γ‐phosphate of ATP and the hydroxyl oxygen of the target tyrosine approached one that could facilitate reaction. The movement of the peptide along the pathways was found to couple with residues in the activation loop of the protein. Although these residues might not affect binding affinity, they might influence the kinetics of peptide entrance and release. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Temperature and pressure denaturation of chignolin: Folding and unfolding simulation by multibaric‐multithermal molecular dynamics method
Authors: Okumura Hisashi
Published: April 2013

A multibaric‐multithermal molecular dynamics (MD) simulation of a 10‐residue protein, chignolin, was performed. All‐atom model with the Amber parm99SB force field was used for the protein and the TIP3P model was used for the explicit water molecules. This MD simulation covered wide ranges of temperature between 260 and 560 K and pressure between 0.1 and 600 MPa and sampled many conformations without getting trapped in local‐minimum free‐energy states. Folding events to the native β‐hairpin structure occurred five times and unfolding events were observed four times. As the temperature and/or pressure increases, fraction of folded chignolin decreases. The partial molar enthalpy change ΔH and partial molar volume change ΔV of unfolding were calculated as ΔH = 24.1 ± 4.9 kJ/mol and ΔV = −5.6 ± 1.5 cm3/mol, respectively. These values agree well with recent experimental results. Illustrating typical local‐minimum free‐energy conformations, folding and unfolding pathways were revealed. When chignolin unfolds from the β‐hairpin structure, only the C terminus or both C and N termini open first. It may undergo an α‐helix or 310‐helix structure and finally unfolds to the extended structure. Difference of the mechanism between temperature denaturation and pressure denaturation is also discussed. Temperature denaturation is caused by making the protein transferred to a higher entropy state and making it move around more with larger space. The reason for pressure denaturation is that water molecules approach the hydrophobic residues, which are not well hydrated at the folded state, and some hydrophobic contacts are broken. Proteins 2012;. © 2012 Wiley Periodicals, Inc.
Kinesin tail domains are intrinsically disordered
Authors: Seeger Mark A. , Zhang Yongbo , Rice Sarah E.
Published: April 2013

Kinesin motor proteins transport a wide variety of molecular cargoes in a spatially and temporally regulated manner. Kinesin motor domains, which hydrolyze ATP to produce a directed mechanical force along a microtubule, are well conserved throughout the entire superfamily. Outside of the motor domains, kinesin sequences diverge along with their transport functions. The nonmotor regions, particularly the tails, respond to a wide variety of structural and molecular cues that enable kinesins to carry specific cargoes in response to particular cellular signals. Here, we demonstrate that intrinsic disorder is a common structural feature of kinesins. A bioinformatics survey of the full‐length sequences of all 43 human kinesins predicts that significant regions of intrinsically disordered residues are present in all kinesins. These regions are concentrated in the nonmotor domains, particularly in the tails and near sites for ligand binding or post‐translational modifications. In order to experimentally verify these predictions, we expressed and purified the tail domains of kinesins representing three different families (Kif5B, Kif10, and KifC3). Circular dichroism and NMR spectroscopy experiments demonstrate that the isolated tails are disordered in vitro, yet they retain their functional microtubule‐binding activity. On the basis of these results, we propose that intrinsic disorder is a common structural feature that confers functional specificity to kinesins. Proteins 2012;. © 2012 Wiley Periodicals, Inc.
Overcoming sequence misalignments with weighted structural superposition
Authors: Khazanov Nickolay A. , Damm‐Ganamet Kelly L. , Quang Daniel X. , Carlson Heather A.
Published: April 2013

An appropriate structural superposition identifies similarities and differences between homologous proteins that are not evident from sequence alignments alone. We have coupled our Gaussian‐weighted RMSD (wRMSD) tool with a sequence aligner and seed extension (SE) algorithm to create a robust technique for overlaying structures and aligning sequences of homologous proteins (HwRMSD). HwRMSD overcomes errors in the initial sequence alignment that would normally propagate into a standard RMSD overlay. SE can generate a corrected sequence alignment from the improved structural superposition obtained by wRMSD. HwRMSD's robust performance and its superiority over standard RMSD are demonstrated over a range of homologous proteins. Its better overlay results in corrected sequence alignments with good agreement to HOMSTRAD. Finally, HwRMSD is compared to established structural alignment methods: FATCAT, secondary‐structure matching, combinatorial extension, and Dalilite. Most methods are comparable at placing residue pairs within 2 Å, but HwRMSD places many more residue pairs within 1 Å, providing a clear advantage. Such high accuracy is essential in drug design, where small distances can have a large impact on computational predictions. This level of accuracy is also needed to correct sequence alignments in an automated fashion, especially for omics‐scale analysis. HwRMSD can align homologs with low‐sequence identity and large conformational differences, cases where both sequence‐based and structural‐based methods may fail. The HwRMSD pipeline overcomes the dependency of structural overlays on initial sequence pairing and removes the need to determine the best sequence‐alignment method, substitution matrix, and gap parameters for each unique pair of homologs. Proteins 2012. © 2012 Wiley Periodicals, Inc.
Crystal packing modifies ligand binding affinity: The case of aldose reductase
Authors: Cousido‐Siah Alexandra , Petrova Tatiana , Hazemann Isabelle , Mitschler André , Ruiz Francesc X. , Howard Eduardo , Ginell Stephan , Atmanene Cédric , Van Dorsselaer Alain , Sanglier‐Cianférani Sarah , Joachimiak Andrzej , Podjarny Alberto
Published: April 2013

The relationship between the structures of protein–ligand complexes existing in the crystal and in solution, essential in the case of fragment‐based screening by X‐ray crystallography (FBS‐X), has been often an object of controversy. To address this question, simultaneous co‐crystallization and soaking of two inhibitors with different ratios, Fidarestat (FID; Kd = 6.5 nM) and IDD594 (594; Kd = 61 nM), which bind to h‐aldose reductase (AR), have been performed. The subatomic resolution of the crystal structures allows the differentiation of both inhibitors, even when the structures are almost superposed. We have determined the occupation ratio in solution by mass spectrometry (MS) Occ(FID)/Occ(594) = 2.7 and by X‐ray crystallography Occ(FID)/Occ(594) = 0.6. The occupancies in the crystal and in solution differ 4.6 times, implying that ligand binding potency is influenced by crystal contacts. A structural analysis shows that the Loop A (residues 122–130), which is exposed to the solvent, is flexible in solution, and is involved in packing contacts within the crystal. Furthermore, inhibitor 594 contacts the base of Loop A, stabilizing it, while inhibitor FID does not. This is shown by the difference in B‐factors of the Loop A between the AR–594 and AR–FID complexes. A stable loop diminishes the entropic energy barrier to binding, favoring 594 versus FID. Therefore, the effect of the crystal environment should be taken into consideration in the X‐ray diffraction analysis of ligand binding to proteins. This conclusion highlights the need for additional methodologies in the case of FBS‐X to validate this powerful screening technique, which is widely used. Proteins 2012. © 2012 Wiley Periodicals, Inc.
The mechanism of the converter domain rotation in the recovery stroke of myosin motor protein
Authors: Baumketner Andrij
Published: April 2013

Upon ATP binding, myosin motor protein is found in two alternative conformations, prerecovery state M* and postrecovery state M**. The transition from one state to the other, known as the recovery stroke, plays a key role in the myosin functional cycle. Despite much recent research, the microscopic details of this transition remain elusive. A critical step in the recovery stroke is the rotation of the converter domain from “up” position in prerecovery state to “down” position in postrecovery state that leads to the swing of the lever arm attached to it. In this work, we demonstrate that the two rotational states of the converter domain are determined by the interactions within a small structural motif in the force‐generating region of the protein that can be accurately modeled on computers using atomic representation and explicit solvent. Our simulations show that the transition between the two states is controlled by a small helix (SH1) located next to the relay helix and relay loop. A small translation in the position of SH1 away from the relay helix is seen to trigger the transition from “up” state to “down” state. The transition is driven by a cluster of hydrophobic residues I687, F487, and F506 that make significant contributions to the stability of both states. The proposed mechanism agrees well with the available structural and mutational studies. Proteins 2012; © 2012 Wiley Periodicals, Inc.
Small‐angle X‐ray scattering reveals architecture and A2B2 stoichiometry of the UvrA–UvrB DNA damage sensor
Authors: Pakotiprapha Danaya , Jeruzalmi David
Published: April 2013

The UvrA–UvrB (AB) protein complex operates in the bacterial nucleotide excision repair pathway as the main sensor of DNA damage. Crystallographic analysis of the AB complex revealed a linear UvrB–UvrA–UvrA–UvrB arrangement of subunits with an internal two‐fold axis that became incorporated into the crystal. Here, we have used small‐angle X‐ray scattering (SAXS) to show close correspondence between the crystal structure and the entity in solution. This result confirms the number and disposition of subunits in the crystallographic model and rules out other possible arrangements suggested by packing in the crystal. The current SAXS analysis failed to detect significant changes to the structure as a function of nucleotide. Proteins 2013. © 2012 Wiley Periodicals, Inc.
A hierarchical order within protein structures underlies large separations between strands in β‐sheets
Authors: Wathen Brent , Jia Zongchao
Published: April 2013

Protein β‐sheets often involve nonlocal interactions between parts of the polypeptide chain that are separated by hundreds of residues, raising the question of how these nonlocal contacts form. A recent study of the smallest β‐sheets found that their formation was not driven by signals hidden in the primary sequence. Instead, the strands in these sheets were either local in sequence, or, when separated by large sequential distances, the intervening residues were found to fold into compact modules that anchored distant parts of the chain in close spatial proximity. Here, we examine larger β‐sheets to investigate the extensibility of this principle. From an analysis of the β‐sheets in a nonredundant protein dataset, we find that a highly ordered hierarchical relationship exists in the intervening structure between nonlocal β‐strands. This observation is almost universal: virtually all β‐sheets, no matter their complexity, appear to adopt an antiparallel model to manage the nonlocal aspects of their assembly, one where the chain, having left the vicinity of an unfinished β‐sheet, retraces its steps via the same route to complete the initial sheet. Exceptions typically involve unstructured regions at chain termini. Moreover, an analysis of the residues involved in nonlocal crossstrand interactions did not produce any evidence of a signal hidden in the sequence that might direct long‐range interactions. These results build on those reported for the smallest sheets, suggesting that sheet formation is either local in sequence or local in space following prior folding events that anchor disparate parts of the chain in close proximity. Proteins 2013. © 2012 Wiley Periodicals, Inc.
Solution NMR structure of a sheddase inhibitor prodomain from the malarial parasite Plasmodium falciparum
Authors: He Yanan , Chen Yihong , Oganesyan Natalia , Ruan Biao , O'Brochta David , Bryan Philip N. , Orban John
Published: April 2013

Plasmodium subtilisin 2 (Sub2) is a multidomain protein that plays an important role in malaria infection. Here, we describe the solution NMR structure of a conserved region of the inhibitory prodomain of Sub2 from Plasmodium falciparum, termed prosub2. Despite the absence of any detectable sequence homology, the protozoan prosub2 has structural similarity to bacterial and mammalian subtilisin‐like prodomains. Comparison with the three‐dimensional structures of these other prodomains suggests a likely binding interface with the catalytic domain of Sub2 and provides insights into the locations of primary and secondary processing sites in Plasmodium prodomains. Proteins 2012;. © 2012 Wiley Periodicals, Inc.
Nematotoxicity of drupacine and a Cephalotaxus alkaloid preparation against the plant‐parasitic nematodes Meloidogyne incognita and Bursaphelenchus xylophilus
Authors: Wen Yanhua , Meyer Susan L F , Masler Edward P , Zhang Fengxian , Liao Jinling , Wei Xiaoyi , Chitwood David J
Published: April 2013

Background

Species of Cephalotaxus (the plum yews) produce nematotoxic compounds of unknown identity. Consequently, bioassay‐guided fractionation was employed to identify the compound(s) in Cephalotaxus fortunei twigs and leaves with activity against plant‐parasitic nematodes.

Results

A crude alkaloid extract, particularly drupacine, was responsible for much of the nematotoxicity. The ED50 of drupacine for Bursaphelenchus xylophilus was 27.1 µg mL−1, and for Meloidogyne incognita it was 76.3 µg mL−1. Immersion of M. incognita eggs in 1.0 mg mL−1 crude alkaloid extract (the highest tested concentration) reduced hatch by 36%; immersion of second‐stage juveniles (J2) resulted in 72–98% immobility. Crude alkaloid extract and drupacine suppressed protease activity in extracts of the microbivorous nematode Panagrellus redivivus by 50% and 80%, respectively. Application of 0.02–0.5 mg mL−1 crude alkaloid extract to soil with M. incognita inoculum did not significantly reduce pepper plant shoot length or weight, compared with nematode‐inoculated, water‐treated controls, but the number of eggs and J2 per root system respectively decreased by 69% and 73% at 0.5 mg mL−1.

Conclusion

Drupacine and a crude alkaloid extract suppress nematode hatch, activity of mixed life stages, and population numbers on plant roots. This is the first demonstration of nematotoxicity of crude Cephalotaxus alkaloids and drupacine. © 2013 Society of Chemical Industry
Light Propagation in Gain Media
Authors: Premaratne Malin , Agrawal Govind P.
Published: April 2013

Over the past two decades, optical amplifiers have become of key importance in modern communications. In addition to this, the technology has applications in cutting-edge research such as biophotonics and lab-on-a-chip devices. This book provides a comprehensive treatment of the fundamental concepts, theory and analytical techniques behind the modern optical amplifier technology. The book covers all major optical amplification schemes in conventional materials, including the Raman and parametric gain processes. The final chapter is devoted to optical gain in metamaterials, a topic that has been attracting considerable attention in recent years. The authors emphasize analytical insights to give a deeper, more intuitive understanding of various amplification schemes. The book assumes background knowledge of electrical engineering or applied physics, including exposure to electrodynamics and wave motion, and is ideal for graduate students and researchers in physics, optics, bio-optics and communications.
Vicarious Traumatization: Potential Hazards and Interventions for Disaster and Trauma Workers
Authors: Palm Kathleen M. , Polusny Melissa A. , Follette Victoria M.
Published: April 2013

Disaster and trauma workers often disregard their own reactions and needs when focusing on caring for those directly exposed to traumatic events. This article discusses the concept of vicarious traumatization, a form of post-traumatic stress response sometimes experienced by those who indirectly are exposed to traumatic events. It includes an examination of how vicarious trauma reactions are experienced across different professions, and suggestions on how to limit or prevent vicarious traumatization. The authors review self-care strategies as well as training and organizational considerations that may be beneficial for individuals and organizations to address.
Wie teuer wird es wirklich?
Authors: Wunsch Eva-Maria , Kliem Sören , Grocholewski Anja , Kröger Christoph
Published: April 2013

Psychische Störungen, insbesondere Angst- und affektive Störungen, kommen in der Allgemeinbevölkerung häufig vor und verursachen erhebliche direkte und indirekte Kosten. Ziel der vorliegenden Analyse ist es, Kosten-Nutzen-Relationen unter der Bedingung zu ermitteln, dass alle behandlungswilligen, von einer Angst- oder affektiven Störung Betroffenen in Deutschland psychotherapeutisch behandelt werden würden. Zu diesem Zweck wurden mithilfe zahlreicher Quellen statistische Kosten- und Nutzenberechnungen für unterschiedliche Ausprägungen von Therapiewilligkeit, -effektivität und -dauer vorgenommen. Bei einer mittleren Ausprägung der Behandlungswilligkeit könnten durch die zusätzliche Behandlung bis zu 100-mal so viele Personen wie aktuell durch eine Psychotherapie als remittiert gelten. Die Kosten-Nutzen-Bilanzen zeigten, dass der finanzielle Nutzen in den meisten Fällen die Behandlungskosten übersteigen würde. Vor allem der erhebliche Hinzugewinn an Lebensqualität spricht für eine breitere psychotherapeutische Versorgung von Betroffenen. Um die Ergebnisse zu validieren, wurde mithilfe der Brogden-Cronbach-Gleser-Formel eine Gewinnschätzung vorgenommen. Die Ergebnisse aus der Anwendung dieser Formel wichen am wenigsten von unseren eigenen Schätzungen ab, wenn die Formel auf konservative Art und Weise eingesetzt wurde. Dieses spricht dafür, dass die eigene Schätzung insgesamt eher konservativ ausgefallen ist. Die Ergebnisse sollten anhand von longitudinalen Psychotherapiestudien überprüft werden. Gesundheitspolitische Implikationen werden diskutiert.
Pulse waveforms for 60 GHz M‐ary pulse position modulation communication systems
Authors: Zhang Hao , Lu Ting‐ting , Gulliver T. Aaron
Published: April 2013

Pulse waveforms for 60 GHz impulse radio (IR) communication systems are investigated. The power spectral densities of the pulses are examined for compliance with Federal Communications Commission (FCC) spectral regulations. The error probability and capacity of M‐ary pulse position modulation (PPM) 60 GHz IR systems with a correlation receiver using different pulse waveforms are analysed. Both orthogonal and non‐orthogonal PPM is considered with additive white Gaussian noise and IEEE 802.15.3c channel models. Analytical and simulation results are presented, which show that an autocorrelation function that decays quickly provides a lower probability of error and better capacity. Among the pulse waveforms examined in this study, the truncated sinc pulse is the best in terms of compliance with FCC regulations and the PPM error probability and capacity.
Impact of the transparent conductive oxide work function on injection-dependent a-Si:H/c-Si band bending and solar cell parameters
Authors: Rößler R. , Leendertz C. , Korte L. , Mingirulli N. , Rech B.
Published: April 2013

An analysis of the contact formation between degenerated n-type transparent conductive oxide (TCO) and p-type amorphous silicon (a-Si:H) as it is used for front side contacts in high efficiency a-Si:H/crystalline silicon (c-Si) heterojunction solar cells is presented. It is shown that the deposition of a TCO on a (p)a-Si:H emitter layer causes a reduction of charge carrier lifetime in low injection levels which leads to a lowering of the implied fill factor. Simulation based analysis of charge carrier lifetime and direct measurements by surface photovoltage reveals that TCO deposition induces a change of the c-Si band bending. The magnitude of this change depends on the (p)a-Si:H doping level. Both observations are explained by the impact of the TCO/a-Si:H work function difference on the c-Si band bending. Based on numerical simulations, the reduced injection-dependent band bending is identified as the reason for the reduced fill factor of final solar cells.
Comparison of boron precipitation in p-type bulk nanostructured and polycrystalline silicon germanium alloy
Authors: Zamanipour Zahra , Krasinski Jerzy S. , Vashaee Daryoosh
Published: April 2013

Boron precipitation process and its effect on electronic properties of p-type bulk nanostructured silicon germanium (Si0.8Ge0.2) compared with large grain polycrystalline Si0.8Ge0.2 have been studied. The structures were synthesized and their thermoelectric properties were measured versus temperature during heating and cooling cycles. The experimental data showed stronger temperature variation of Seebeck coefficient, carrier concentration, and conductivity in the nanostructured Si0.8Ge0.2 compared with the polycrystalline form indicating stronger boron precipitation in this structure. The electrical properties of both samples were calculated using a multi-band semi-classical model. The theoretical calculations confirm that the increase of boron precipitation in the nanostructured Si0.8Ge0.2 is responsible for its higher thermal instability. Since the thermoelectric properties of the nanostructured sample degrade as a result of thermal cycling, the material is appropriate only for continuous operation at high temperature without cooling.
On the crystal structure and magnetic properties of the Mn0.94Ti0.06CoGe alloy
Authors: Shamba P. , Wang J. L. , Debnath J. C. , Zeng R. , Hong F. , Cheng Z. X. , Studer A. J. , Kennedy S. J. , Dou S. X.
Published: April 2013

Structural and magnetic properties of Mn0.94Ti0.06CoGe have been studied by a combination of bulk magnetisation and neutron diffraction measurements over the temperature range of 5 K–350 K. The crystal structural transition occurs at Tstr (∼235 K) with a change in symmetry from the low temperature orthorhombic TiNiSi-type structure (space group Pnma) to the high temperature hexagonal Ni2In-type structure (space group P63/mmc) and the magnetic phase transition takes place around TC = 270 K. It is found that the structural transition around Tstr is incomplete and there is a co-existence of the orthorhombic and hexagonal structures between Tstr and TC (∼270 K). These results are discussed in connection with the magnetic and magnetocaloric behaviours in Mn0.94Ti0.06CoGe.
X-ray photoemission analysis of chemically modified TlBr surfaces for improved radiation detectors
Authors: Nelson A. J. , Voss L. F. , Beck P. R. , Graff R. T. , Conway A. M. , Nikolic R. J. , Payne S. A. , Lee J.-S. , Kim H. , Cirignano L. , Shah K.
Published: April 2013

Device-grade TlBr was subjected to various chemical treatments used in room temperature radiation detector fabrication to determine the resulting surface composition and electronic structure. As-polished TlBr was treated separately with HCl, SOCl2, Br:MeOH, and HF solutions. High-resolution photoemission measurements on the valence band electronic structure and Tl 4f, Br 3d, Cl 2p, and S 2p core lines were used to evaluate surface chemistry and shallow heterojunction formation. Surface chemistry and valence band electronic structure were correlated with the goal of optimizing the long-term stability and radiation response.
Size effects in the temperatures of phase transitions in KNbO3 nanopowder
Authors: Golovina I. S. , Bryksa V. P. , Strelchuk V. V. , Geifman I. N. , Andriiko A. A.
Published: April 2013

The paper reports on thorough Raman-scattering study of newly synthesized nanoscale powders of potassium niobate (KNbO3) aimed at evaluating the possible modification of the phase transition temperatures versus the corresponding bulk values. We register a significant expansion of the temperature ranges of all phase transitions, which is attributed to a wide distribution of particle sizes. An average temperature of each phase transition shifts to the high-temperature region differently, namely by 10°, 25°, and 40°, as compared with corresponding transition temperature in bulk crystals of KNbO3 and amounts 0, 248, and 475 °C, respectively. In the range from 100 to 110 °C, we also find the features, which could be associated with an additional rearrangement of the structure.
Defect-induced performance degradation of 4H-SiC Schottky barrier diode particle detectors
Authors: Iwamoto N. , Johnson B. C. , Hoshino N. , Ito M. , Tsuchida H. , Kojima K. , Ohshima T.
Published: April 2013

The formation and evolution of defects in 4H-SiC Schottky barrier diode high-energy particle detectors have been investigated and correlated with the detectors' properties. Low temperature annealing at 300 °C is found to significantly recover the charge collection efficiency as degraded by 1 MeV electron irradiation. At higher temperatures, an anneal-induced degradation in the detector's performance is observed. Current-voltage, capacitance-voltage, and deep level transient spectroscopy (DLTS) measurements are used to ascertain the effect of defects on the detector performance. The latter reveals that the DLTS defect levels, EH1 and EH3, are related to the initial recovery of the charge collection efficiency.
High-resolution imaging of zeolite with aberration-corrected transmission electron microscopy
Authors: Yoshida Kaname , Sasaki Yukichi , Kurata Hiroki
Published: April 2013

We demonstrated high-resolution imaging of atomic columns in zeolite frameworks with spherical aberration-corrected transmission electron microscopy(AC-HRTEM). An MFI-type zeolite was observed by AC-HRTEM with optimized optical setup. Compared with the conventional imaging mode based on a positive spherical aberration, the negative spherical aberrationimaging (NCSI) mode sharpened image contrasts at atomic column positions. The projected atomic columns of zeolite are so complex that sharp image contrast can help to distinguish each atomic column position.
Growth performance and intestinal morphology in broiler chickens produced from hyperthyroid breeder hens
Authors: Akhlaghi A. , Zamiri M. J. , Ahangari Y. Jafari , Mollasalehi M. R. , Shojaie H. , Atashi H. , Navidshad B. , Akhlaghi A. A. , Dadpasand M.
Published: April 2013

An association between induced maternal hyperthyroidism and a decreased incidence of cold-induced ascites in broiler chickens has been reported recently. There are also reports suggesting that thyroid hormones have an effect on intestine, a high oxygen-demanding organ. The present study aimed to determine whether the ascites-attenuating effect of maternal hyperthyroidism is associated with morphological changes in intestine and with probable adverse effects on growth performance in progeny chicks. Eighty-eight broiler breeder hens were allotted to control or hyperthyroid [HYPER; thyroxine-treated] groups, and artificially inseminated. Hatching eggs (n = 924) were incubated and day-old male chicks (n = 288) were reared for 42 days under standard or low ambient temperature. Plasma thyroxine was higher in the HYPER hens and their embryos at internal pipping. Maternal hyperthyroidism did not adversely affect the feed : gain ratio and carcass weight, whereas cold stress impaired them. A higher relative weight was found at 42 days of age for all intestinal regions at low ambient temperature. The duodenal and jejunal crypt depths (CD) were lower in HYPER group at 7 days of age. Cold exposure decreased the duodenal and jejunal villus height and CD, and increased the ileal goblet cell number at 21 days. On Day 42, higher values were recorded for CD, goblet cell number, and epithelial thickness of different intestinal regions in cold-exposed birds. In conclusion, growth performance was not adversely influenced by maternal hyperthyroidism and its minimal early effect on intestinal morphology does not appear to be the underlying mechanism for decreased incidence of ascites in broilers.
Using elemental profiles in the sediment of a lake used to supply drinking water to understand the impacts of urban stormwater recharge
Authors: Vanderzalm J. L. , Dillon P. J. , Hancock G. J. , Leslie C. , Dighton J. , Smith C. , Pearce G.
Published: April 2013

The regional city of Mount Gambier, South Australia, recharges stormwater directly into the underlying unconfined, karstic Gambier Limestone aquifer. This aquifer provides the majority of recharge to Blue Lake, a groundwater-fed volcanic crater lake, used for Mount Gambier’s drinking water supply. However, concern remains regarding the risk posed by contaminants within stormwater, in particular when stormwater recharge may ultimately contribute to a source of drinking-water supply. The present research examined the role of the annual calcite precipitation in the lake, in protecting the quality of its water supply, by examining the composition of particulate matter in the lake and on the lake bottom. The sediment did not reveal negative impacts of stormwater recharge, but did highlight the increase in erosion as a result of settlement and extensive land clearing for agriculture at the time of settlement. Analysis of lake-floor sediment revealed increased accumulation of the lithogenic elements within the lake-floor sediment during this interval, owing to the cleansing capacity of the calcite precipitation cycle. Extraction of water from Blue Lake for water supply has resulted in a reduced water residence time in the lake and a three-fold increase in the accumulation of calcium carbonate on the lake floor.
Averaging v. outlier removal. Decrypting variance among cryptic Lejeunea species (Lejeuneaceae: Jungermanniopsida) using geometric morphometrics
Authors: Renner Matt A. M. , Brown Elizabeth A. , Wardle Glenda M.
Published: April 2013

Molecular data have revealed many morphologically cryptic species. More surprising than lack of difference, however, is that morphological variation and complex patterns of overlapping features can mask cryptic species. We employ geometric morphometric methods (GMM) to explore patterns of variation within four liverwort species, three of which were previously attributed to Lejeunea tumida Mitt. Each species exhibited considerable variation within, and overlap among, species in size and shape, independent of degree of relatedness. Most variation was expressed within individuals, suggesting that the observed breadth of variation was within the developmental capacity of single genotypes. Size and shape variation within, and consequently overlap among, individuals resulted primarily from variance in growth of shoots. Inter-specific differences were swamped by intra- and inter-individual variation. We coupled GMM with multivariate methods for outlier removal, and simple averaging of individuals to explore whether intra-individual variation could be reconciled to maximise the inter-species difference, facilitating resolution of cryptic species despite extensive morphological continuity and overlap. Unfortunately, outlier removal did not achieve separation among species, because removing extremes failed to eliminate overlap resulting from within-species variation. Individual averaging was partially successful in extracting L. tumida as a discrete entity but did not segregate the remaining three species. Although the challenges for morphology-based identification of cryptic species are significant, GMM provide one of the best sets of methods for identifying and communicating any subtle morphological differences that may exist.
Molecular hierarchy of mammary differentiation yields refined markers of mammary stem cells
Authors: dos Santos Camila O. , Rebbeck Clare , Rozhkova Elena , Valentine Amy , Samuels Abigail , Kadiri Lolahon R. , Osten Pavel , Harris Elena Y. , Uren Philip J. , Smith Andrew D. , Hannon Gregory J.
Published: April 2013

The partial purification of mouse mammary gland stem cells (MaSCs) using combinatorial cell surface markers (Lin
−
CD24
+
CD29
h
CD49f
h
) has improved our understanding of their role in normal development and breast tumorigenesis. Despite the significant improvement in MaSC enrichment, there is presently no methodology that adequately isolates pure MaSCs. Seeking new markers of MaSCs, we characterized the stem-like properties and expression signature of label-retaining cells from the mammary gland of mice expressing a controllable H2b-GFP transgene. In this system, the transgene expression can be repressed in a doxycycline-dependent fashion, allowing isolation of slowly dividing cells with retained nuclear GFP signal. Here, we show that H2b-GFP
h
cells reside within the predicted MaSC compartment and display greater mammary reconstitution unit frequency compared with H2b-GFP
neg
MaSCs. According to their transcriptome profile, H2b-GFP
h
MaSCs are enriched for pathways thought to play important roles in adult stem cells. We found Cd1d, a glycoprotein expressed on the surface of antigen-presenting cells, to be highly expressed by H2b-GFP
h
MaSCs, and isolation of Cd1d
+
MaSCs further improved the mammary reconstitution unit enrichment frequency to nearly a single-cell level. Additionally, we functionally characterized a set of MaSC-enriched genes, discovering factors controlling MaSC survival. Collectively, our data provide tools for isolating a more precisely defined population of MaSCs and point to potentially critical factors for MaSC maintenance.
Muscle Weakness Predicts Pharyngeal Dysfunction and Symptomatic Aspiration in Long-term Ventilated Patients
Authors: Mirzakhani Hooman , Williams June-Noelle , Mello Jennifer , Joseph Sharma , Meyer Matthew J. , Waak Karen , Schmidt Ulrich , Kelly Emer , Eikermann Matthias
Published: April 2013

Background:

Prolonged mechanical ventilation is associated with muscle weakness, pharyngeal dysfunction, and symptomatic aspiration. The authors hypothesized that muscle strength measurements can be used to predict pharyngeal dysfunction (endoscopic evaluation–primary hypothesis), as well as symptomatic aspiration occurring during a 3-month follow-up period.

Methods:

Thirty long-term ventilated patients admitted in two intensive care units at Massachusetts General Hospital were included. The authors conducted a fiberoptic endoscopic evaluation of swallowing and measured muscle strength using medical research council score within 24 h of each fiberoptic endoscopic evaluation of swallowing. A medical research council score less than 48 was considered clinically meaningful muscle weakness. A retrospective chart review was conducted to identify symptomatic aspiration events.

Results:

Muscle weakness predicted pharyngeal dysfunction, defined as either valleculae and pyriform sinus residue scale of more than 1, or penetration aspiration scale of more than 1. Area under the curve of the receiver-operating curves for muscle strength (medical research council score) to predict pharyngeal, valleculae, and pyriform sinus residue scale of more than 1, penetration aspiration scale of more than 1, and symptomatic aspiration were 0.77 (95% CI, 0.63–0.97; P = 0.012), 0.79 (95% CI, 0.56–1; P = 0.02), and 0.74 (95% CI, 0.56–0.93; P = 0.02), respectively. Seventy percent of patients with muscle weakness showed symptomatic aspiration events. Muscle weakness was associated with an almost 10-fold increase in the symptomatic aspiration risk (odds ratio = 9.8; 95% CI, 1.6–60; P = 0.009).

Conclusion:

In critically ill patients, muscle weakness is an independent predictor of pharyngeal dysfunction and symptomatic aspiration. Manual muscle strength testing may help identify patients at risk of symptomatic aspiration.
The antibiotic susceptibility of water-based bacteria Ralstonia pickettii and Ralstonia insidiosa
Authors: Ryan Michael P. , Adley Catherine C.
Published: April 2013

Ralstonia pickettii and Ralstonia insidiosa are waterborne bacteria that can survive and grow in various water sources, and that are emerging pathogens in hospital settings. Not much is known about the antibiotic resistance of these bacteria. Previous reports of antimicrobial susceptibility have been largely limited to a few clinical strains with no accounting for genotypic or phenotypic diversity or that these species could vary from the set breakpoints. Etests and disc diffusion tests were carried out to compare the antimicrobial susceptibilities to 12 different antibiotics of 68 different isolates of R. pickettii (53) and R. insidiosa (15) from varying environments, which have previously been well characterized both phenotypically and genetically. The majority of the R. pickettii and R. insidiosa isolates showed susceptibility to most of the antibiotics tested in this study. The most effective were found to be the quinolones and sulfamethoxazole/trimethoprim. Antibiotic susceptibility was also found not to vary between environmental niches for R. pickettii and R. insidiosa isolates.
Analysis of classical swine fever virus RNA replication determinants using replicons
Authors: Risager Peter Christian , Fahnøe Ulrik , Gullberg Maria , Rasmussen Thomas Bruun , Belsham Graham J.
Published: April 2013

Self-replicating RNAs (replicons), with or without reporter gene sequences, derived from the genome of the Paderborn strain of classical swine fever virus (CSFV) have been produced. The full-length viral cDNA, propagated within a bacterial artificial chromosome, was modified by targeted recombination within Escherichia coli. RNA transcripts were produced in vitro and introduced into cells by electroporation. The translation and replication of the replicon RNAs could be followed by the accumulation of luciferase (from Renilla reniformis or Gaussia princeps) protein expression (where appropriate), as well as by detection of CSFV NS3 protein production within the cells. Inclusion of the viral E2 coding region within the replicon was advantageous for replication efficiency. Production of chimeric RNAs, substituting the NS2 and NS3 coding regions (as a unit) from the Paderborn strain with the equivalent sequences from the highly virulent Koslov strain or the vaccine strain Riems, blocked replication. However, replacing the Paderborn NS5B coding sequence with the RNA polymerase coding sequence from the Koslov strain greatly enhanced expression of the reporter protein from the replicon. In contrast, replacement with the Riems NS5B sequence significantly impaired replication efficiency. Thus, these replicons provide a system for determining specific regions of the CSFV genome required for genome replication without the constraints of maintaining infectivity.