bluuebunny/crossref_metadata_2025 huggingface dataset:
Trains of transcranial direct current stimulation antagonize motor cortex hypoexcitability induced by acute hemicerebellectomy
Authors: Ben Taib Nordeyn Oulad , Manto Mario
Published: April 2009

Object

The cerebellum is a key modulator of motor cortex activity, allowing both the maintenance and fine-tuning of motor cortex discharges. One elemental defect associated with acute cerebellar lesions is decreased excitability of the contralateral motor cortex, which is assumed to participate in deficits in skilled movements and considered a major defect in motor cortex properties. In the present study, the authors assessed the effect of trains of anodal transcranial direct current stimulation (tDCS), which elicits polarity-dependent shifts in resting membrane potentials.

Methods

Transcranial DCS countered the defect in motor cortex excitability contralaterally to the hemicerebellar ablation.

Results

The depression of both the H-reflex and F wave remained unchanged with tDCS, and cutaneomuscular reflexes remained unaffected. Transcranial DCS antagonized motor cortex hypoexcitability induced by high-frequency stimulation of interpositus nucleus.

Conclusions

The authors' results show that tDCS has the potential to modulate motor cortex excitability after acute cerebellar dysfunction. By putting the motor cortex at the appropriate level of excitability, tDCS might allow the motor cortex to become more reactive to the procedures of training or learning.
Surface-based facial scan registration in neuronavigation procedures: a clinical study
Authors: Shamir Reuben R. , Freiman Moti , Joskowicz Leo , Spektor Sergey , Shoshan Yigal
Published: April 2009

Object

Surface-based registration (SBR) with facial surface scans has been proposed as an alternative for the commonly used fiducial-based registration in image-guided neurosurgery. Recent studies comparing the accuracy of SBR and fiducial-based registration have been based on a few targets located on the head surface rather than inside the brain and have yielded contradictory conclusions. Moreover, no visual feedback is provided with either method to inform the surgeon about the estimated target registration error (TRE) at various target locations. The goals in the present study were: 1) to quantify the SBR error in a clinical setup, 2) to estimate the targeting error for many target locations inside the brain, and 3) to create a map of the estimated TRE values superimposed on a patient's head image.

Methods

The authors randomly selected 12 patients (8 supine and 4 in a lateral position) who underwent neurosurgery with a commercial navigation system. Intraoperatively, scans of the patients' faces were acquired using a fast 3D surface scanner and aligned with their preoperative MR or CT head image. In the laboratory, the SBR accuracy was measured on the facial zone and estimated at various intracranial target locations. Contours related to different TREs were superimposed on the patient's head image and informed the surgeon about the expected anisotropic error distribution.

Results

The mean surface registration error in the face zone was 0.9 ± 0.35 mm. The mean estimated TREs for targets located 60, 105, and 150 mm from the facial surface were 2.0, 3.2, and 4.5 mm, respectively. There was no difference in the estimated TRE between the lateral and supine positions. The entire registration procedure, including positioning of the scanner, surface data acquisition, and the registration computation usually required < 5 minutes.

Conclusions

Surface-based registration accuracy is better in the face and frontal zones, and error increases as the target location lies further from the face. Visualization of the anisotropic TRE distribution may help the surgeon to make clinical decisions. The observed and estimated accuracies and the intraoperative registration time show that SBR using the fast surface scanner is practical and feasible in a clinical setup.
Feasibility of ventricular expansion postmortem: a novel laboratory model for neurosurgical training that simulates intraventricular endoscopic surgery
Authors: Tubbs R. Shane , Loukas Marios , Shoja Mohammadali M. , Wellons John C. , Cohen-Gadol Aaron A.
Published: April 2009

Object

Cadavers are often used in the teaching of various neurosurgical procedures. One aspect of this resource that has not been previously explored is the postmortem dilation of the ventricular system, which is often collapsed, for the purpose of training neurosurgeons in the use of intraventricular endoscopy.

Methods

Nine adult cadavers without a history of hydrocephalus or other known intracranial pathology were used for this study. Four specimens were obtained post embalming, and 5 specimens were fresh (time from death until the procedure < 5 hours). In all cadavers catheters were placed into the lateral ventricles; saline and then air were injected into the ventricles through the catheters. Ventriculostomy sites were filled with rubber stoppers, and in fresh specimens, formal embalming was performed with cadavers in the Trendelenburg position. Lastly, serial horizontal sectioning of the cranium was performed in all cadavers to verify ventricular dilation.

Results

None of the 4 embalmed specimens were found to have ventriculomegaly following injection. However, this condition was found in 4 of the 5 fresh specimens. In the single fresh cadaver without ventriculomegaly, the cause of death had been massive intracranial subarachnoid hemorrhage, which distorted the ventricular system. This may have prevented cannulation of the ventricle and ventricular expansion in this specimen.

Conclusions

The ventricular system of fresh human cadavers can be dilated postmortem. The method described herein may be useful to neurosurgical trainees or those trained neurosurgeons wishing to practice intraventricular endoscopy.
Radiosurgery for intracranial hemangiopericytomas: outcomes after initial and repeat Gamma Knife surgery
Authors: Olson Claire , Yen Chun-Po , Schlesinger David , Sheehan Jason
Published: April 2009

Object

Intracranial hemangiopericytoma is a rare CNS tumor that exhibits a high incidence of local recurrence and distant metastasis. The purpose of this study was to evaluate the role of Gamma Knife surgery (GKS) in the management of intracranial hemangiopericytomas.

Methods

In a review of the University of Virginia radiosurgery database between 1989 and 2008, the authors found recurrent or residual hemangiopericytomas after resection in 21 patients in whom radiosurgery was performed to treat 28 discrete tumors. The median age of this population was 47 years (range 31–61 years) at the time of the initial GKS. Prior treatments included embolization (6), transcranial resection (39), transsphenoidal resection (2), and fractionated radiotherapy (8). The mean prescription and maximum radiosurgical doses to the tumors were 17.0 and 40.3 Gy, respectively. Repeat radiosurgery was used to treat 13 tumors. The median follow-up period was 68 months (range 2–138 months).

Results

At last follow-up, local tumor control was demonstrated in 47.6% of the patients (10 of 21 patients) with hemangiopericytomas. Of the 28 tumors treated, 8 decreased in size on follow-up imaging (28.6%), 5 remained unchanged (17.9%), and 15 ultimately progressed (53.6%). The progression-free survival rates were 90, 60.3, and 28.7% at 1, 3, and 5 years after initial GKS. The progression-free survival rate improved to 95, 71.5, and 71.5% at 1, 3, and 5 years after multiple GKS treatments. The 5-year survival rate after radiosurgery was 81%. Prior fractionated irradiation or radiosurgical prescription dose did not correlate with tumor control. In 4 (19%) of 21 patients extracranial metastases developed.

Conclusions

Radiosurgery is a reasonable treatment option for recurrent hemangiopericytomas. Long-term close clinical and imaging follow-up is necessary because of the high probability of local recurrence and distant metastases. Repeat radiosurgery may be used to treat new or recurrent hemangiopericytomas over a long follow-up course.
Overexpression of a Weed (Solanum americanum) Proteinase Inhibitor in Transgenic Tobacco Results in Increased Glandular Trichome Density and Enhanced Resistance to Helicoverpa armigera and Spodoptera litura
Authors: Luo Ming , Wang Zhaoyu , Li Huapeng , Xia Kuai-Fei , Cai Yinpeng , Xu Zeng-Fu
Published: April 2009

In this study we produced transgenic tobacco plants by overexpressing a serine proteinase inhibitor gene, SaPIN2a, from the American black nightshade Solanum americanum under the control of the CaMV 35S promoter using Agrobacterium tumefaciens-mediated transformation. SaPIN2a was properly transcribed and translated as indicated by Northern blot and Western blot analyses. Functional integrity of SaPIN2a in transgenic plants was confirmed by proteinase inhibitory activity assay. Bioassays for insect resistance showed that SaPIN2a-overexpressing transgenic tobacco plants were more resistant to cotton bollworm(Helicoverpa armigera) and tobacco cutworm(Spodoptera litura) larvae, two devastating pests of important crop plants, than the control plants. Interestingly, overexpression of SaPIN2a in transgenic tobacco plants resulted in a significant increase in glandular trichome density and a promotion of trichome branching, which could also provide an additional resistance mechanism in transgenic plants against insect pests. Therefore, SaPIN2a could be used as an alternative proteinase inhibitor for the production of insect-resistant transgenic plants.
Heterogeneity of Mitochondria and Mitochondrial Function within Cells as Another Level of Mitochondrial Complexity
Authors: Kuznetsov Andrey  V. , Margreiter Raimund
Published: April 2009

Beyond their fundamental role in energy metabolism, mitochondria perform a great variety of other important cellular functions. However, the interplayamong these various roles of mitochondria is still poorly understood, and the underlying mechanisms can be related to system level properties. Importantly, mitochondria localized in different regions of a cell may display different morphology, dissimilar biochemical properties, or may differently interact with other intracellular structures. Recent advances in live imaging techniques have also revealed a functional heterogeneity of mitochondria with respect to mitochondrial redox state, membrane potential, respiratory activity, uncoupling proteins, mitochondrial ROS and calcium. An important and still unresolved question is how the heterogeneity of mitochondrial function and the regional specializations of mitochondria are mechanistically realized in the cell and to what extent this could be dependent on environmental aspects. Distinct mitochondrial subsets may also exhibit different responses to substrates and inhibitors and may vary in their sensitivity to pathology, resistance to apoptosis, oxidative stress, thus also demonstrating heterogeneous behavior. All these observations strongly suggest that the intracellular position, organization and the specific surroundings of mitochondria within the cell define their functional features, while also implying that different mitochondrial subpopulations, clusters or even single mitochondrion may execute diverse processes in a cell. The heterogeneity of mitochondrial function demonstrates an additional level of mitochondrial complexity and is a new, challenging area in mitochondrial research that potentially leads to the integration of mitochondrial bioenergetics and cell physiology with various physiological and pathophysiological implications.
Sensing Human Activity: GPS Tracking
Authors: Van der Spek Stefan , Van Schaick Jeroen , De Bois Peter , De Haan Remco
Published: April 2009

The enhancement of GPS technology enables the use of GPS devices not only as navigation and orientation tools, but also as instruments used to capture travelled routes: as sensors that measure activity on a city scale or the regional scale. TU Delft developed a process and database architecture for collecting data on pedestrian movement in three European city centres, Norwich, Rouen and Koblenz, and in another experiment for collecting activity data of 13 families in Almere (The Netherlands) for one week. The question posed in this paper is: what is the value of GPS as ‘sensor technology’ measuring activities of people? The conclusion is that GPS offers a widely useable instrument to collect invaluable spatial-temporal data on different scales and in different settings adding new layers of knowledge to urban studies, but the use of GPS-technology and deployment of GPS-devices still offers significant challenges for future research.
Application of Neurocomputing for Data Approximation and Classification in Wireless Sensor Networks
Authors: Jabbari Amir , Jedermann Reiner , Muthuraman Ramanan , Lang Walter
Published: April 2009

A new application of neurocomputing for data approximation and classification is introduced to process data in a wireless sensor network. For this purpose, a simplified dynamic sliding backpropagation algorithm is implemented on a wireless sensor network for transportation applications. It is able to approximate temperature and humidity in sensor nodes. In addition, two architectures of “radial basis function” (RBF) classifiers are introduced with probabilistic features for data classification in sensor nodes. The applied approximation and classification algorithms could be used in similar applications for data processing in embedded systems.
A Near-Infrared Spectrometer Based on Novel Grating Light Modulators
Authors: Wei Wei , Huang Shanglian , Wang Ning , Jin Zhu , Zhang Jie , Chen Weimin
Published: April 2009

A near-infrared spectrometer based on novel MOEMS grating light modulators is proposed. The spectrum detection method that combines a grating light modulator array with a single near-infrared detector has been applied. Firstly, optics theory has been used to analyze the essential principles of the proposed spectroscopic sensor. Secondly, the grating light modulators have been designed and fabricated by micro-machining technology. Finally, the principles of this spectroscopic sensor have been validated and its key parameters have been tested by experiments. The result shows that the spectral resolution is better than 10 nm, the wavelength deviation is less than 1 nm, the deviation of the intensity of peak wavelength is no more than 0.5%, the driving voltage of grating light modulators array device is below 25 V and the response frequency of it is about 5 kHz. With low cost, satisfactory precision, portability and other advantages, the spectrometer should find potential applications in food safety and quality monitoring, pharmaceutical identification and agriculture product quality classification.
Measurement Uncertainty Estimation of a Robust Photometer Circuit
Authors: Hernandez Wilmar , De Vicente Jesús
Published: April 2009

In this paper the uncertainty of a robust photometer circuit (RPC) was estimated. Here, the RPC was considered as a measurement system, having input quantities that were inexactly known, and output quantities that consequently were also inexactly known. Input quantities represent information obtained from calibration certificates, specifications of manufacturers, and tabulated data. Output quantities describe the transfer function of the electrical part of the photodiode. Input quantities were the electronic components of the RPC, the parameters of the model of the photodiode and its sensitivity at 670 nm. The output quantities were the coefficients of both numerator and denominator of the closed-loop transfer function of the RPC. As an example, the gain and phase shift of the RPC versus frequency was evaluated from the transfer function, with their uncertainties and correlation coefficient. Results confirm the robustness of photodiode design.
Preparation of 1,4:5,8‐Dimethano‐1,2,3,4,5,6,7,8‐Octahydro‐9,10‐Dimethoxyanthracenium Hexachloroantimonate (4
+
SbCl
6
−
): A Highly Robust Radical‐Cation Salt
Authors: Rathore Rajendra , Burns Carrie L. , Deselnicu Mihaela I.
Published: April 2009

1,4:5,8‐Dimethano‐1,4,4a,5,8,8a,9a,10a‐octahydroanthracene‐9,10‐dione

1,4:5,8‐Dimethanododecahydroanthracene‐9,10‐dione

1,4:5,8‐Dimethano‐1,2,3,4,5,6,7,8‐octahydranthracene‐9,10‐diol

1,4:5,8‐Dimethano‐1,2,3,4,5,6,7,8‐octahydro‐9,10‐dimethoxy‐anthracene

p
‐Benzoquinone

Cyclopentadiene

Antimony pentachloride
Preparation of (

S

,

S

)‐1,2‐Bis‐(

tert

‐Butylmethylphosphino)Ethane ((

S

,

S

)‐

t

‐
Bu
‐Bis
P
*) As A Rhodium Complex
Authors: Crépy Karen V. L. , Imamoto Tsuneo
Published: April 2009

Tert
‐Butyldichlorophosphine

Methylmagnesium bromide

Borane‐tetrahydrofuran

(
tert
‐Butyldimethylphosphine)trihydroboron

sec
‐Butyllithium

Sparteine

Trifluoromethylsulfonic acid

(Norbornadiene)rhodium chloride dimmer

Rhodium(1+), [2,3,5,6 η)‐bicyclo[2.2.1]hepta‐2,5‐diene]bis(methyldiphenylphosphine)‐, tetrafluroborate (1−)
Synthesis of an
Anti
‐α‐Amino Epoxide by One‐Carbon Homologation of an α‐Amino Ester: (2

S

,3

S

)‐1,2‐Epoxy‐3‐(Boc‐Amino)‐4‐Phenylbutane
Authors: Wang Dengjin , Nugent William A.
Published: April 2009

Trimethylsulfoxonium iodide

Boc‐L‐phenylalanine 4‐nitrophenyl ester

Dimethylsulfoxonium (
S
)‐2‐oxo‐3‐(Boc‐amino)‐4‐phenylbutylide

(
S
)‐1‐Chloro‐3‐(Boc‐amino)‐4‐phenyl‐2‐butanone

Lithium tri‐tert‐butoxyaluminum hydride

(2
S
, 3
S
)‐1,2‐Epoxy‐3‐(Boc‐amino‐4‐phenylbutane
Synthesis of 4‐Triisopropylsilyl‐3‐Butyn‐2‐ol by Asymmetric Transfer Hydrogenation
Authors: Marshall James A. , Eidam Patrick , Eidam Hilary Schenck
Published: April 2009

(
rac
)‐4‐Triisopropylsilyl‐3‐butyn‐2‐ol

Triisopropylsilyl acetylene

Tert
‐BuLi

Acetaldehyde

4‐Triisopropylsilyl‐3‐butyne‐2‐one

Manganese dioxide

Ruthenium, [
N
‐(1
S
,2
S
)‐2‐(amino‐kappa‐
N
)‐1,2‐diphenylethyl]‐4‐methyl‐benzenesulfonamidato‐kappa‐
N
]chloro[(1,2,3,4,5,6‐eta)‐1‐methyl‐4‐(1‐methylethyl)benzene]

(1
S
,2
S
)‐(+)‐
N
‐
p
‐toluenesulfonyl‐1,2‐diphenylethylenediamine

Dichloro(
p
‐cymene)ruthenium(II) dimer

(
S
)‐4‐Triisopropylsilyl‐3‐butyn‐2‐ol
Preparation of (η
5
‐(

S

)‐2‐(4‐Methylethyl)‐Oxazolinylcyclopentadienyl)‐(η
4
‐Tetraphenylcyclo‐Butadiene)cobalt
Authors: Anderson Carolyn E. , Overman Larry E. , Richards Christopher J. , Watson Mary P. , White Nicole
Published: April 2009

(eta5‐Carbomethoxycyclopentadienyl)‐(eta4‐tetraphenylcyclobutadiene)cobalt

Sodium cyclopentadienide

Chloro(triphenylphosphine)cobalt(I)

Diphenylacetylene

Lithium iodide

2,4,6‐Collidine

Oxalyl chloride

N
,
N
‐Dimethylformamide

(
S
)‐Valinol

Triethylamine

Methanesulfonyl chloride
1,3‐Dichloroacetone as a Cyclopropanone Equivalent: 5‐Oxaspiro[3.4]Octan‐1‐One
Authors: Hilmey David G. , Paquette Leo A.
Published: April 2009

2,3‐Dihydrofuran

1,3‐Dichloracetone

Lithium naphthalenide

5‐Oxaspiro[3,4]octan‐1‐one
Copper(I) Iodide Dimethyl Sulfide Catalyzed Addition of a Vinylzirconium Reagent Preparation of 4‐Phenyl‐5(E)‐Decen‐2‐One
Authors: El‐Batta Amer , Bergdahl Mikael
Published: April 2009

Schwartz's reagent

Sodium benzophenone ketyl

1‐Hexyne

Benzalacetone

Copper(I) iodide

Dimethyl sulfide
Mono Carbamate Protection of Aliphatic Diamines Using Alkyl Phenyl Carbonates
Authors: Pittelkow Michael , Lewinsky Rasmus , Christensen Jorn B
Published: April 2009

Tert
‐Butyl phenyl carbonate

1,2‐Ethanediamine
A New Practical One‐Pot Conversion of Phenols to Anilines: 6‐Amino‐3,4‐Dihydro‐1(2

H

)‐Naphthalenone
Authors: Mizuno Masahiro , Yamano Mitsuhisa
Published: April 2009

6‐Amino‐3,4‐dihydro‐1(2
H
)‐naphthalenone, 6‐amino‐1‐tetralone

2‐Bromo‐2‐methylpropanamide

2‐Bromo‐2‐methylpropanoyl bromide

3,4‐Dihydro‐6‐hydroxy‐1(2
H
)‐naphthalenone, 6‐hydroxy‐1‐tetralone

2‐Methyl‐2‐[(5‐oxo‐5,6,7,8‐tetrahydro‐2‐naphthalenyl)oxy]propanamide

2‐Hydroxy‐2‐methyl‐
N‐(
5‐oxo‐5,6,7,8,‐tetrahydro‐2‐naphthalenyl)propanamide
One‐Flask Synthesis of Methyl Arylvinyldiazoacetates and their Application in Enantioselective
C
‐
H
Functionalization: Synthesis of (

E

)‐Methyl 2‐Diazo‐4‐Phenylbut‐3‐Enoate and (

S
,
E

)‐Methyl 2‐((

R

)‐4‐Methyl‐1,2‐Dihydronaphthalen‐2‐
YL
)‐4‐Phenylbut‐3‐Enoate
Authors: Manning James R. , Davies Huw M. L.
Published: April 2009

3‐Chloropropionic acid

Triphenylphosphine

2‐Carboxyethyltriphenylphosphonium chloride

Iodomethane

Magnesium

Alpha‐Tetrakone

1‐Methyl‐3,4‐dihydronaphthalene

(
E
)‐Methyl 2‐azo‐4‐phenylbut‐3‐enoate

Benzaldehyde

Potassium
tert
‐butoxide

Dimethyl sulfate

p
‐Acetoamidobenzenesulfonyl azide

DBU

(
S,E
)‐Methyl 2‐(R‐4‐methyl‐1,2‐dihydronaphthalen‐2‐yl)‐4‐phenylbut‐3‐enoate

Rh2(
S
‐DOSP)4
Light Harvesting by a Periodic Mesoporous Organosilica Chromophore
Authors: Inagaki Shinji , Ohtani Osamu , Goto Yasutomo , Okamoto Kentaro , Ikai Masamichi , Yamanaka Ken‐ichi , Tani Takao , Okada Tadashi
Published: April 2009

Licht‐Aquädukt: Periodische mesoporöse Organosilicate absorbieren wegen der dichtgepackten organischen Chromophore in den Porenwänden Licht sehr stark. Die durch 125 Biphenylgruppen in den Porenwänden absorbierte Lichtenergie wird mit fast 100 % Quantenausbeute zu einem einzigen Cumarin‐1‐Molekül in den Mesokanälen geleitet, was eine signifikante Erhöhung der Emission des Cumarin‐1‐Farbstoffs zur Folge hat.

magnified image
In Situ Formation of Diazonium Salts from Nitro Precursors for Scanning Electrochemical Microscopy Patterning of Surfaces
Authors: Cougnon Charles , Gohier Frédéric , Bélanger Daniel , Mauzeroll Janine
Published: April 2009

Spitzenchemie: Die In‐situ‐Herstellung von Diazoniumsalzen aus Nitroverbindungen ermöglicht es, Diazoniumchemie zur mikroelektrochemischen Bildung von Oberflächenmustern durch elektrochemische Rastersondenmikroskopie zu nutzen. Die Nitrovorstufe wird an der Spitze zum Amin reduziert, das während seiner Diffusion zur Oberfläche diazotiert wird (siehe Bild). Die Spitze wirkt als eine Quelle von Diazoniumsalzen, die eine Probenderivatisierung direkt unterhalb der Spitze ermöglicht.

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Vielfältige Reaktivitäten: aktuelle Entwicklungen bei metallkatalysierten Alkinreaktionen
Authors: Anaya de Parrodi Cecilia , Walsh Patrick J.
Published: April 2009

Was Alkine alles können: Dank entscheidender Fortschritte bei metallkatalysierten Alkinreaktionen konnte der präparative Nutzen von Alkinen in letzter Zeit deutlich erhöht werden. Damit ist nun ein breiteres Spektrum von Alkinen durch C‐N‐ und C‐C‐Bindungsbildung zugänglich, und darüber hinaus wurde gezeigt, dass difunktionelle Heterodimetallkatalysatoren zu neuen Reaktivitäten und hervorragenden Enantioselektivitäten führen können (siehe Schema).

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Non‐Hydrolyzable RNA–Peptide Conjugates: A Powerful Advance in the Synthesis of Mimics for 3′‐Peptidyl tRNA Termini
Authors: Moroder Holger , Steger Jessica , Graber Dagmar , Fauster Katja , Trappl Krista , Marquez Viter , Polacek Norbert , Wilson Daniel N. , Micura Ronald
Published: April 2009

Die Translation kleiner Peptideam Ribosom kann diesem eine Resistenz gegen Macrolidantibiotika verleihen. Zur Aufklärung dieses und ähnlicher Phänomene sind stabile RNA‐Peptid‐Konjugate, die Peptidyl‐tRNA imitieren, wünschenswert, besonders für die strukturbiologische Untersuchung von Ribosomen. Eine flexible Festphasensynthesestrategie macht diese Konjugate nun in effizienter Weise zugänglich, ohne Beschränkungen bezüglich der RNA‐ und Peptidsequenz.

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Oriented Monolayer Film of Gd2O3:0.05 Eu Crystallites: Quasi‐Topotactic Transformation of the Hydroxide Film and Drastic Enhancement of Photoluminescence Properties
Authors: Hu Linfeng , Ma Renzhi , Ozawa Tadashi C. , Sasaki Takayoshi
Published: April 2009

Caught on film: A semitransparent and intensely luminescent monolayer film of oriented Gd2O3:0.05 Eu platelet crystallites is fabricated by annealing the precursor hydroxide film (see scheme). The photoluminescence properties of the as‐transformed film are greatly improved over those of the hydroxide film, and are much more pronounced than those of the corresponding Gd2O3:0.05 Eu powder.

magnified image
In Situ Formation of Diazonium Salts from Nitro Precursors for Scanning Electrochemical Microscopy Patterning of Surfaces
Authors: Cougnon Charles , Gohier Frédéric , Bélanger Daniel , Mauzeroll Janine
Published: April 2009

Give me a tip: In situ production of diazonium salts from nitro compounds allows the use of diazonium chemistry for microelectrochemical patterning of surfaces by scanning electrochemical microscopy. The nitro precursor is reduced at the tip to the amine, which is diazotized in the interelectrode space as it diffuses (see picture). The tip acts as a source of diazonium salts, allowing sample derivatization just beneath the tip.

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Response expectancies: a psychological mechanism of suggested and placebo analgesia
Authors: Milling Leonard S.
Published: April 2009

Response expectancies, or the expectation of one's own non‐volitional reactions to situational cues, are hypothesized to be a psychological mechanism of both hypnotic and placebo responding (Kirsch, 1990). In this study, response expectancies were evaluated as a mediator of suggested and placebo analgesia using Baron and Kenny's (1986) classic method of testing mediation. One hundred and seventy‐two volunteers were randomly assigned to hypnotic analgesia suggestion, imaginative analgesia suggestion, placebo analgesia, or no‐treatment control conditions. The hypnotic, imaginative and placebo treatments were more effective than the no‐treatment control condition in relieving finger pressure pain. The hypnotic treatment was also more effective than the placebo. Each of the three treatments was partially mediated by response expectancies, although the percentage of mediation varied across the hypnotic (25%), imaginative (29%) and placebo (41%) conditions. The findings support the position that response expectancies are one of the major psychological mechanisms of suggested and placebo analgesia. Copyright © 2009 British Society of Experimental & Clinical Hypnosis. Published by John Wiley & Sons, Ltd.
Control of Spouted Bed Dryers
Authors: Corrêa Nivaldo A. , Costa Carlos E. S. , Corrêal Ronaldo G. , Freire José T.
Published: April 2009

During the last 8 years, the Drying Center at Universidade Federal de São Carlos has been investigating the control problems of drying process of pasty materials associated with the spouted bed dryer. Starting with structures involving PI controller, we also implemented advanced MPC control techniques and real time optimization (this last one based on simulations only). Different control structures were implemented in a pilot spouted bed dryer where the behavior of the system was tested for water and homogenized chicken eggs. Based on promising results, the perspective is to use an adequate control system in a spouted bed scale‐up.
Parallelizing secure linear programming
Authors: Deitos Rafael , Kerschbaum Florian
Published: April 2009

Information sharing in supply chain management can dramatically improve the performance of the supply chain. Although many such problems can be modeled and efficiently solved using linear programming (LP), security requirements prevent their implementation in the traditional way. Companies are simply reluctant to exchange such sensitive information. Secure multi‐party computation can help by realizing protocols with guaranteed security. However, efficiency is a major concern. Parallel computing presents an opportunity to improve performance utilizing inherent parallel secure operations. This work focuses on practical approaches to privacy preserving parallel protocols for collaborative LP. First, it theoretically compares the approach of parallelizing a secure algorithm and securing a parallel algorithm. Their complexity being equal we implemented the simpler choice: parallelizing a secure algorithm. Different synchronization methods for the implementation are compared under different network conditions. Given the best implementation, the performance is almost independent of the network conditions, but parallelization, i.e. number of threads, needs to be adapted to such conditions. We present and evaluate an adaptive scheduling algorithm for the dynamic selection of the number of threads, such that it's not necessary to statically and up‐front determine the number for optimal speed‐up. The algorithm can even deal with varying network conditions. Copyright © 2009 John Wiley & Sons, Ltd.
Spam filtering for network traffic security on a multi‐core environment
Authors: Islam Rafiqul , Zhou Wanlei , Xiang Yang , Mahmood Abdun Naser
Published: April 2009

This paper presents an innovative fusion‐based multi‐classifier e‐mail classification on a ubiquitous multi‐core architecture. Many previous approaches used text‐based single classifiers to identify spam messages from a large e‐mail corpus with some amount of false positive tradeoffs. Researchers are trying to prevent false positive in their filtering methods, but so far none of the current research has claimed zero false positive results. In e‐mail classification false positive can potentially cause serious problems for the user. In this paper, we use fusion‐based multi‐classifier classification technique in a multi‐core framework. By running each classifier process in parallel within their dedicated core, we greatly improve the performance of our multi‐classifier‐based filtering system in terms of running time, false positive rate, and filtering accuracy. Our proposed architecture also provides a safeguard of user mailbox from different malicious attacks. Our experimental results show that we achieved an average of 30% speedup at an average cost of 1.4 ms. We also reduced the instances of false positives, which are one of the key challenges in a spam filtering system, and increases e‐mail classification accuracy substantially compared with single classification techniques. Copyright © 2009 John Wiley & Sons, Ltd.
Photoinduced Nonadiabatic Dynamics of 9H‐Guanine
Authors: Lan Zhenggang , Fabiano Eduardo , Thiel Walter
Published: April 2009

Surface‐hopping simulations are used to study the nonradiative relaxation of 9H‐guanine. Two distinct S1→S0 (ππ*→gs) decay channels, both of which pass through a conical intersection (CI), are found to be responsible for the experimentally observed double‐decay behavior (see schematic diagram).

magnified image

The photoinduced nonadiabatic decay dynamics of 9H‐guanine is investigated by surface‐hopping calculations at the semiempirical OM2/MRCI level of theory. Following excitation, fast internal conversion from the ππ* (La) excited state to the ground state is observed within 800 fs. Relaxation proceeds through two distinct S1→S0 pathways. The first channel goes through a conical intersection with pronounced out‐of‐plane displacement of the C2 atom and yields ultrafast decay with a time constant of 190 fs. The second channel evolves through a conical intersection with strong out‐of‐plane distortion of the amino group and leads to slower decay with a lifetime of 400 fs. These decay mechanisms and the computed decay times are consistent with the available experimental evidence and previous theoretical studies.
Insensitivity regions for deformation measurement on a dam
Authors: Fišerová Eva , Kubáček Lubomír
Published: April 2009

Deformation measurement during the filling a dam can be modelled by a multivariate model. Multivariate models usually involve unknown parameters not only in the mean value of the observation matrix but also in the covariance matrix (variance components). The variance components must be estimated and plug‐in estimators for the mean value parameters can be used. To find statistical properties of plug‐in estimators is rather difficult. In some cases the sensitivity approach can be used. If we know that the true value of the variance components is with sufficiently high probability in so‐called insensitivity region, then the plug‐in estimator is almost the best linear unbiased estimator. The aim of the paper is to investigate this insensitivity regions, i.e. the region around the true value of variance components, where small changes of them are only of negligible influence on the mean value parameter estimators. The obtained results are applied on the problem of deformation measurement during the filling a dam. Copyright © 2009 John Wiley & Sons, Ltd.
Erosional unloading, hillslope geometry, and the height of the Cascade Range, Washington State, USA
Authors: Mitchell Sara , Montgomery David , Greenberg Harvey
Published: April 2009

Peaks in the Cascade Range in northern Washington State are on average ∼800 m higher than in southern Washington. The influences of differential valley excavation and variations in hillslope length and average slope on these altitudinal trends were tested using a 3‐dimensional model for isostatic rock uplift and calculations of hillslope length and slope respectively. The magnitude of isostatic peak uplift calculated by the model is highly dependent on the flexural rigidity (D) and the related effective elastic thickness (Te) of the crust of this region. Crustal rigidity was constrained using published estimates and by estimating the depth of the seismogenic zone in the area (D > 1 × 1023 Nm and Te > 24 km). With these constraints, isostatic compensation due to differential erosion added < 700 m and 300 m, or < 25% overall, of height to peaks in the northern and southern Cascades, respectively. Deeper valley incision in the northern Cascades accounts for < 300 m of the 800 m difference in peak altitudes between north and south. Similarly, variation in valley spacing and slope account for < 350 m of the difference in mean altitude between northern and southern regions. Hence, at least several hundred m difference in altitude between the northern and southern regions of the Cascades in Washington must be due to tectonic, geologic, or geophysical factors rather than surficial and geomorphic effects like isostatic response to valley incision and hillslope geometry. Copyright © 2009 John Wiley & Sons, Ltd.
Differences in psychological morbidity among Australian and Chinese caregivers of persons with dementia in residential care
Authors: Wu Helen Zong Ying , Low Lee‐Fay , Xiao Shifu , Brodaty Henry
Published: April 2009

Objective

The aim of the present study was to determine the effects of culture on caregiver psychological morbidity among informal caregivers of institutionalised persons with dementia in three different populations: (1) Shanghai, (2) Australian‐Chinese and (3) Australian mainstream (non‐Chinese).

Methods

Caregivers and residents with dementia were recruited from (1) a dementia hospital in Shanghai, (2) three ethno‐specific Chinese nursing homes in Sydney and (3) four mainstream nursing homes in Sydney. Psychological morbidity was assessed using the Geriatric Depression Scale, mental health component (MHC) of the RAND‐36 Health Status Inventory and a guilt scale.

Results

There were no significant differences between the three groups as measured by the guilt scale and MHC. Shanghai caregivers had higher mean depression scores than Australian‐Chinese caregivers (p < 0.001), who in turn had higher mean depression scores than Australian mainstream caregivers (p = 0.015). Higher depression scores were found to be inversely associated with the caregiver's education level and physical health status, and associated with increased frequency of nursing home visits, but not with levels of behavioural and psychological symptoms of dementia (BPSD).

Conclusion

Levels of depression in caregivers of institutionalised persons with dementia differ by culture and country of residence. Copyright © 2009 John Wiley & Sons, Ltd.
A model for intervention research in late‐life depression
Authors: Alexopoulos George S. , Bruce Martha L.
Published: April 2009

Objective

To serve as a conceptual map of the role of new interventions designed to reduce the burden of late‐life depression.

Methods

We identified three needs to be addressed by intervention research: (1) the need for novel interventions given that the existing treatments leave many older adults depressed and disabled; (2) the need for procedures enabling community‐based agencies to offer interventions of known efficacy with fidelity; and (3) the need to increase access of depressed older adults to care.

Results

Our model orders novel interventions according to their role in serving depressed older adults and according to their position in the efficacy, effectiveness, implementation, and dissemination testing continuum. We describe three interventions designed by our institute to exemplify intervention research at different level of the model. A common element is that each intervention personalizes care both at the level of the individuals served and the level of community agencies providing care. To this end, each intervention is designed to accommodate the strengths and limitations of both patients and agencies and introduces changes in the patients' environment and community agencies needed in order to assimilate the new intervention.

Conclusions

We suggest that this model provides conceptual guidance on how to shorten the testing cycle and bring urgently needed novel treatments and implementation approaches to the community. While replication studies are important, propose that most of the support should be directed to those projects that take rational risks, and after adequate preliminary evidence, make the next step along the testing continuum. Copyright © 2009 John Wiley & Sons, Ltd.
Skeletal muscle glucose uptake during exercise: A focus on reactive oxygen species and nitric oxide signaling
Authors: Merry Troy L. , McConell Glenn K.
Published: April 2009

Like insulin, muscle contraction (in vitro or in situ) and exercise increase glucose uptake into skeletal muscle. However, the contraction/exercise pathway of glucose uptake in skeletal muscle is an independent pathway to that of insulin. Indeed, skeletal muscle glucose uptake is normal during exercise in those who suffer from insulin resistance and diabetes. Thus, the pathway of contraction‐mediated glucose uptake into skeletal muscle provides an attractive potential target for pharmaceutical treatment and prevention of such conditions, especially as skeletal muscle is the major site of impaired glucose disposal in insulin resistance. The mechanisms regulating skeletal muscle glucose uptake during contraction have not been fully elucidated. Potential regulators include Ca2+ (via CaMK's and/or CaMKK), AMPK, ROS, and NO signaling, with some redundancy likely to be evident within the system. In this review, we attempt to briefly synthesize current evidence regarding the potential mechanisms involved in regulating skeletal muscle glucose uptake during contraction, focusing on ROS and NO signaling. While reading this review, it will become clear that this is an evolving field of research and that much more work is required to elucidate the mechanism(s) regulating skeletal muscle glucose uptake during contraction. © 2009 IUBMB IUBMB Life 61(5): 479–484, 2009
E2F1 transcription is induced by genotoxic stress through ATM/ATR activation
Authors: Carcagno Abel L. , Ogara María F. , Sonzogni Silvina V. , Marazita Mariela C. , Sirkin Pablo F. , Ceruti Julieta M. , Cánepa Eduardo T.
Published: April 2009

E2F1, a member of the E2F family of transcription factors, plays a critical role in controlling both cell cycle progression and apoptotic cell death in response to DNA damage and oncogene activation. Following genotoxic stresses, E2F1 protein is stabilized by phosphorylation and acetylation driven to its accumulation. The aim of the present work was to examine whether the increase in E2F1 protein levels observed after DNA damage is only a reflection of an increase in E2F1 protein stability or is also the consequence of enhanced transcription of the E2F1 gene. The data presented here demonstrates that UV light and other genotoxics induce the transcription of E2F1 gene in an ATM/ATR dependent manner, which results in increasing E2F1 mRNA and protein levels. After genotoxic stress, transcription of cyclin E, an E2F1 target gene, was significantly induced. This induction was the result of two well‐differentiated effects, one of them dependent on de novo protein synthesis and the other on the protein stabilization. Our results strongly support a transcriptional effect of DNA damaging agents on E2F1 expression. The results presented herein uncover a new mechanism involving E2F1 in response to genotoxic stress. © 2009 IUBMB IUBMB Life, 61(5): 537–543, 2009
Serine proteases
Authors: Di Cera Enrico
Published: April 2009

Details of the active site of Trypsin. See Serine Proteases by Di Cera, pp. 510–515.
A semiparametric model for binary response and continuous outcomes under index heteroscedasticity
Authors: Klein Roger , Vella Francis
Published: April 2009

This paper formulates a likelihood‐based estimator for a double‐index, semiparametric binary response equation. A novel feature of this estimator is that it is based on density estimation under local smoothing. While the proofs differ from those based on alternative density estimators, the finite sample performance of the estimator is significantly improved. As binary responses often appear as endogenous regressors in continuous outcome equations, we also develop an optimal instrumental variables estimator in this context. For this purpose, we specialize the double‐index model for binary response to one with heteroscedasticity that depends on an index different from that underlying the ‘mean response’. We show that such (multiplicative) heteroscedasticity, whose form is not parametrically specified, effectively induces exclusion restrictions on the outcomes equation. The estimator developed exploits such identifying information. We provide simulation evidence on the favorable performance of the estimators and illustrate their use through an empirical application on the determinants, and affect, of attendance at a government‐financed school. Copyright © 2009 John Wiley & Sons, Ltd.
Force‐field parameters of the Ψ and Φ around glycosidic bonds to oxygen and sulfur atoms
Authors: Saito Minoru , Okazaki Isao
Published: April 2009

The Ψ and Φ torsion angles around glycosidic bonds in a glycoside chain are the most important determinants of the conformation of a glycoside chain. We determined force‐field parameters for Ψ and Φ torsion angles around a glycosidic bond bridged by a sulfur atom, as well as a bond bridged by an oxygen atom as a preparation for the next study, i.e., molecular dynamics free energy calculations for protein‐sugar and protein‐inhibitor complexes. First, we extracted the Ψ or Φ torsion energy component from a quantum mechanics (QM) total energy by subtracting all the molecular mechanics (MM) force‐field components except for the Ψ or Φ torsion angle. The Ψ and Φ energy components extracted (hereafter called “the remaining energy components”) were calculated for simple sugar models and plotted as functions of the Ψ and Φ angles. The remaining energy component curves of Ψ and Φ were well represented by the torsion force‐field functions consisting of four and three cosine functions, respectively. To confirm the reliability of the force‐field parameters and to confirm its compatibility with other force‐fields, we calculated adiabatic potential curves as functions of Ψ and Φ for the model glycosides by adopting the Ψ and Φ force‐field parameters obtained and by energetically optimizing other degrees of freedom. The MM potential energy curves obtained for Ψ and Φ well represented the QM adiabatic curves and also these curves' differences with regard to the glycosidic oxygen and sulfur atoms. Our Ψ and Φ force‐fields of glycosidic oxygen gave MM potential energy curves that more closely represented the respective QM curves than did those of the recently developed GLYCAM force‐field. © 2009 Wiley Periodicals, Inc., J Comput Chem, 2009
Conformational analysis of hydroxymatairesinol in aqueous solution with molecular dynamics
Authors: Sandberg Thomas , Hotokka Matti
Published: April 2009

Molecular dynamics simulations were performed on the naturally occuring lignan hydroxymatairesinol (HMR) using the GROMACS software. The aim of this study was to explore the conformational behavior of HMR in aqueous solution adopting the TIP4P model. The topology of HMR was constructed by hand and HMR was modeled with the OPLS‐AA force field implemented in GROMACS. The five torsional angles in HMR were properly analyzed during the simulations. Correlations through certain patterns were observed between the angles. The determining property for the conformation preferred in aqueous solution was found to be the dipole moment and not the lowest energy in gas phase. The solvation effects on HMR was also studied by quantum chemical calculations applying the COnductorlike Screening MOdel (COSMO), the results of which were compared with results from a previous study using the Polarized Continuum Model (PCM). In the present work, COSMO was found to give more credible relative energies than PCM. © 2009 Wiley Periodicals, Inc., J Comput Chem, 2009
Adenovirus type 5 with modified hexons induces robust transgene‐specific immune responses in mice with pre‐existing immunity against adenovirus type 5
Authors: Abe Shinya , Okuda Kenji , Ura Takehiro , Kondo Asami , Yoshida Atsushi , Yoshizaki Shinji , Mizuguchi Hiroyuki , Klinman Dennis , Shimada Masaru
Published: April 2009

Background

Adenovirus type 5 (Ad5) is widely used as a vehicle for vaccine delivery in the treatment of infectious disease and cancer. However, the efficacy of Ad5 vectors has been limited in humans because exposure to Ad5 infections results in most adults having neutralizing antibodies against Ad5. To overcome this limitation, the hexon epitope present in the fifth hypervariable region of Ad5 was modified.

Methods

To evaluate the ability of Ad5 vectors encoding the HIV env protein to induce Ag‐specific immune responses in the face of pre‐existing anti‐Ad5 immunity, mice were administrated intramuscularly with the Ad‐Luc vector, and then vaccinated with parental or hexon‐modified Ad5 vectors (Ad‐HisHIV, Ad‐END/AAAHIV or Ad‐HIV) at week 8. HIV‐specific cell‐mediated immune responses were detected through a combination of tetramer assays and intracellular cytokine staining from weeks 8–23.

Results

The hexon‐modified Ad vector was able to escape from anti‐Ad5 neutralizing antibody, and mice with the modified vector generated significantly lower individual neutralizing antibody than those immunized with the parental vector. Furthermore, mice with pre‐existing anti‐Ad immunity immunized with the modified vector generated significantly stronger cell‐mediated anti‐env responses than those immunized with the parental vector.

Conclusions

These data demonstrate that Ad5 vector with hexon modification reduce their sensitivity to pre‐existing anti‐Ad immunity and improve their clinical utility. Copyright © 2009 John Wiley & Sons, Ltd.
Molecular recognition properties of tartrates and metal‐tartrates in solution and gas phase
Authors: Wijeratne Aruna B. , Schug Kevin A.
Published: April 2009

Solution phase and gas phase chiral molecular recognition properties of tartrates (salts or esters of tartaric acid) and metal tartrates (binuclear tartrato(4‐)‐metal‐bridged complexes) are reviewed in conjunction with their applications in enantiomeric separation science and their mass spectrometric chiral discrimination properties.