bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of botulinum toxin‐induced paralysis on postnatal development of the supraspinatus muscle
Authors: Das Rosalina , Rich Jason , Kim H. Mike , McAlinden Audrey , Thomopoulos Stavros
Published: August 2010

The mechanical environment plays an important role in musculoskeletal tissue development. The present study characterized changes in supraspinatus muscle due to removal of mechanical cues during postnatal development. An intramuscular injection of botulinum toxin type A (BTX) was used to induce and maintain paralysis in the left shoulders of mice since birth while the right shoulders received saline and served as contralateral controls. A separate group of animals was allowed to develop normally without any injections. Muscles were examined postnatally at various time points. The maximum isometric tetanic force generated by the muscle was significantly reduced in the BTX group compared to saline and normal groups. The paralyzed muscles were smaller and showed significant muscle atrophy and fat accumulation on histologic evaluation. Myogenic genes myogenin, myoD1, myf5, myf6, and fast type II myosin heavy chain (MHC) isoform were significantly upregulated while slow type I MHC isoform was significantly downregulated in the BTX group. Adipogenic genes C/EBPα, PPARγ2, leptin, and lipoprotein lipase were significantly upregulated in the BTX group. Results indicate that reduced muscle loading secondary to BTX‐induced paralysis leads to fat accumulation and muscle degeneration in the developing muscle. Understanding the molecular and compositional changes in developing supraspinatus muscles may be useful for identifying and addressing the pathological changes that occur in shoulder injuries such as neonatal brachial plexus palsy. © 2010 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 29:281–288, 2011
Background removal from polarized Raman spectra of tooth enamel using the wavelet transform
Authors: Li Jianghua , Choo‐Smith Lin‐P'ing , Tang Zhilie , Sowa Michael G.
Published: August 2010

A wavelet transformation method is introduced to remove the large fluorescence background from polarized Raman spectra of stained tooth enamel. This method exploits the wavelet multiresolution decomposition where the experimental Raman spectrum is decomposed into signals with different frequency components, and where the lowest frequency background and highest frequency noise are removed. This method is optimized using a simulated collection of parallel‐polarized and cross‐polarized Raman spectra of the enamel and then applied to a set of experimental data. The results show that the wavelet transform technique can extract the pure spectra from background and noise, with the depolarization ratio used to discriminate between early dental caries and sound enamel preserved. Copyright © 2010 Crown in the right of Canada. Published by John Wiley & Sons, Ltd.
Using Raman spectroscopy to monitor surface finish and roughness of components manufactured by selective laser sintering
Authors: Beard M. A. , Ghita O. R. , Evans K. E.
Published: August 2010

Selective laser sintering (SLS) is an additive manufacturing process used to realise fully functional component manufacture. Numerous parameters are used in the process to control variables such as laser power, scan speed, laser spot size and overlap of scan vectors. All of these parameters can dramatically alter the sintering process and therefore final component properties. This paper presents how Raman spectroscopy intensity effects, caused by the surface roughness of the components produced, can be used to monitor the degree of sintering between particles in the SLS process. Copyright © 2010 John Wiley & Sons, Ltd.
Visualization of β‐carotene and starch granules in plant cells using CARS and SHG microscopy
Authors: Brackmann Christian , Bengtsson Anton , Alminger Marie Larsson , Svanberg Ulf , Enejder Annika
Published: August 2010

Information on the content and bioavailability of provitamin A carotenoids, such as β‐carotene, in plant foods is of great interest due to the widespread vitamin A deficiency in developing countries. While the amount of β‐carotene can readily be quantified with analytical techniques, there is limited information on β‐carotene morphology in native plant materials. Here, we introduce nonlinear microscopy for three‐dimensional, label‐free imaging of carotenoids in fresh and thermally treated plant tissues, providing quantitative information at single‐aggregate level and detailed insight into their distribution. Carotenoids in orange‐fleshed sweet potato (OFSP), carrot, and mango were visualized by coherent anti‐Stokes Raman scattering (CARS) microscopy and, in the case of OFSP, related to the plant‐matrix morphology by simultaneous second‐harmonic generation (SHG) microscopy of starch granules. Sizes, shapes, densities, and location of different types of carotenoid bodies were quantified. While OFSP and carrot showed heterogeneous rod‐shaped bodies with high carotenoid densities indicated by higher CARS signals, the carotenoid‐filled lipid droplets in mango appeared as homogeneous low‐density aggregates of rounded shape. In addition, β‐carotene densities and morphologies in OFSP were studied after thermal processing, showing that the bodies remain intact despite significant changes of the surrounding starch granules. Copyright © 2010 John Wiley & Sons, Ltd.
Surface‐enhanced Raman spectroscopy of DNA from leaves of in vitro grown apple plants
Authors: Muntean Cristina M. , Leopold Nicolae , Halmagyi Adela , Valimareanu Sergiu
Published: August 2010

Ultrasensitive Raman measurements of nucleic acids are possible by exploiting the effect of surface‐enhanced Raman scattering (SERS). In this work, the vibrational spectra of eight genomic DNAs from in vitro grown apple leaf tissues (Malus domestica Borkh., Fam Rosaceae, cvs. Florina, Idared, Rebra, Goldrush, Romus 3, Romus 4 and the rootstocks M9 and M26) were analyzed using surface‐enhanced Raman spectroscopy, in the wavenumber range 200–1800 cm−1. SERS signatures, spectroscopic band assignments and structural interpretations of these plant genomic DNAs are reported. Strong dependences of the SERS spectra on genomic DNA amount in the measured sample volume and on time were observed. Similarities of the SERS signals of DNAs from Rebra and Romus 3 leaves were detected. To our knowledge, this is the first SERS study on genomic DNA from leaf tissues. The present work provides a basis for future use of surface‐enhanced Raman spectroscopy to analyze specific plant DNA–ligand interactions or DNA structural changes induced by plants' stress conditions associated with their natural environment. Besides, this study will generate information that is valuable in the development of low‐level plant DNA‐based analytical sensors. Copyright © 2010 John Wiley & Sons, Ltd.
New HPLC‐chemometric approaches to the analysis of isoflavones in Trifolium lucanicum Gasp.
Authors: Küçükboyacı Nurgün , Güvenç Ayşegül , Dinç Erdal , Adıgüzel Nezaket , Bani Barış
Published: August 2010

New HPLC‐chemometric approaches were proposed for the simultaneous chromatographic quantification of daidzein, genistein, formononetin, and biochanin A in the samples consisting of the aerial parts of Trifolium lucanicum Gasp. (Leguminosae). Partial least squares and principal component regression algorithms were applied to the multiple chromatographic data set obtained by measuring at 240, 248, 256, and 264 nm to construct HPLC‐partial least squares and HPLC‐principal component regression calibrations. Chromatographic separation was carried out by using a mobile phase containing methanol, acetate buffer (pH=4.75) and acetonitrile (21:58:21, v/v/v) on the reversed phase column, Supelcosil™ LC‐18 (15 cm×4.6 mm id). In addition, conventional HPLC based on the detection at a single wavelength was used for the determination of each compound in the extracts of T. lucanicum. The validity and applicability of the proposed HPLC‐chemometric and conventional HPLC methods were performed by analyzing various synthetic plant samples. A good agreement was observed in the application of the proposed HPLC‐chemometric tools to the synthetic and extracted samples of T. lucanicum.
Analysis of Aloe‐based phytotherapeutic products by using nano‐LC‐MS
Authors: Fanali Salvatore , Aturki Zeineb , D'Orazio Giovanni , Rocco Anna , Ferranti Anna , Mercolini Laura , Raggi Maria Augusta
Published: August 2010

This article proposes a chromatographic method for the analysis of extracts of Aloe plants. The method was developed with a laboratory assembled nano‐LC system coupled with a UV detector, followed by an IT‐mass spectrometer. With a step gradient mode of ACN/H2O mixtures and employing a capillary column packed with C18 (100 μm id), a complete separation of the following anthrones was achieved: aloin (in its two isomeric forms A and B), 5‐hydroxyaloin and 7‐hydroxyaloin (in its two isomeric forms A and B). The optimized nano‐LC‐MS method was validated for the quantification of aloin, the main component of Aloe with known pharmacological activities. RSD values obtained for retention time and peak areas were 1.3 and 12.1%, respectively. LOD and LOQ values of 0.4 and 1.5 μg/mL were obtained for each aloin isomer. The method was applied to the analysis of Aloe vera and A. ferox extracts in order to acquire a fingerprint, characteristic for each plant. Several phenolic compounds were detected by UV and identified by MS. A. vera and A. ferox showed different profiles and it was possible to discriminate them. Several commercial formulations, declared to contain Aloe extracts, were analyzed. Comparing their chromatograms with those obtained from A. vera and A. ferox, it was possible to recognize the Aloe species and to determine aloin.
Pharyngeal swallow adaptations to bolus volume measured with high‐resolution manometry
Authors: Hoffman Matthew R. , Ciucci Michelle R. , Mielens Jason D. , Jiang Jack J. , McCulloch Timothy M.
Published: August 2010

Objective:

To determine the effect of bolus volume on pharyngeal swallowing using high‐resolution manometry (HRM).

Study Design:

Repeated measures with subjects serving as own controls.

Methods:

Twelve subjects swallowed four bolus volumes in the neutral head position: saliva; 5 mL water; 10 mL water; and 20 mL water. Pressure measurements were taken along the length of the pharynx using a high‐resolution manometer, with emphasis placed on the velopharynx, tongue base, and upper esophageal sphincter (UES). Variables were analyzed across bolus volumes using three‐way repeated measures analysis of covariance (ANCOVA) investigating the effect of sex, bolus volume, and pharynx length. Pearson's product moment tests were performed to evaluate how pharyngeal pressure and timing events changed across bolus volume.

Results:

Velopharyngeal duration, maximum tongue base pressure, tongue base pressure rise rate, UES opening duration, and total swallow duration varied significantly across bolus volume. Sex did not have an effect, whereas pharynx length appeared to affect tongue base pressure duration. Maximum velopharyngeal pressure and minimum UES pressure had a direct relationship with bolus volume, whereas maximum tongue base pressure had an inverse relationship. Velopharyngeal pressure duration, UES opening duration, and total swallow duration increased as bolus volume increased.

Conclusions:

Differences in pharyngeal pressures and timing of key pressure events were detected across varying bolus volumes. Knowing the relationships between bolus volume and pharyngeal pressure activity can be valuable when diagnosing and treating dysphagic patients. Laryngoscope, 120:2367–2373, 2010
Nasoseptal flap takedown and reuse in revision endoscopic skull base reconstruction
Authors: Zanation Adam M. , Carrau Ricardo L. , Snyderman Carl H. , McKinney Kibwei A. , Wheless Stephen A. , Bhatki Amol M. , Gardner Paul A. , Prevedello Daniel M. , Kassam Amin B.
Published: August 2010

Objectives/Hypothesis:

To provide a description of the techniques and limitations of nasoseptal flap takedown and reuse during second‐stage and revision endoscopic skull base surgery and review the institutional experience with the use of this reconstructive technique.

Study Design:

Case series.

Methods:

A retrospective analysis of cerebrospinal fluid (CSF) leak outcomes was performed for a consecutive series of patients who underwent the nasoseptal flap takedown technique during endoscopic skull base surgery at two tertiary care skull base centers.

Results:

Twenty‐eight consecutive cases with nasoseptal flap takedown procedures for endoscopic skull base reconstruction were collected and evaluated for flap viability and CSF leak outcomes. This cohort was composed of 14 revision surgeries and 14 planned second‐stage procedures. There were no cases of flap loss. Twenty cases involved the presence of intraoperative CSF leaks. Twelve of these 20 cases were second‐stage surgeries, and eight were revision or recurrent‐tumor procedures. Nineteen of 20 had successful skull base reconstruction without a postoperative CSF leak. One patient required revision endoscopic CSF leak repair and bolstering of the defect with a fat graft 3 days after the initial surgery. Endoscopic skull base reconstructive techniques and limitations of flap takedowns are discussed.

Conclusions:

Expansion of the limits of endoscopic skull base surgery must be accompanied by the development of new reconstructive options. This report illustrates the ability to take down and reuse the nasoseptal flap in staged and revision cases with a high success rate and minimal additional nasal morbidity. Laryngoscope, 2011
Good correlation between original and modified house Brackmann facial grading systems
Authors: Henstrom Douglas K. , Skilbeck Christopher J. , Weinberg Julie , Knox Christopher , Cheney Mack L. , Hadlock Tessa A.
Published: August 2010

Objectives/Hypothesis:

Subjective scales of facial function were plagued with reporting variations until the House‐Brackmann scale was described in 1985. Despite its utility, weaknesses were identified, including noninclusion of synkinesis phenomena and insensitivity to segmental weakness. Therefore, the scale was recently revised to address these weaknesses. The objective of this investigation was to determine agreement between the original and the updated House‐Brackmann scales.

Study Design:

Prospective clinical trial.

Methods:

Fifty consecutive new facial paralysis patients underwent standardized facial videography while performing facial movements. Video clips were scored by three independent facial nerve clinicians. The time it took to produce a score for each method was tracked. Interobserver correlations were calculated, and comparisons were made between scores by using the original and modified House‐Brackmann scales.

Results:

Interobserver correlation was high for both House‐Brackmann scales. Overall scores were in excellent agreement (difference of 0.1 ± 0.5, no statistical difference), although the modified scale took substantially longer to calculate (120 seconds ± 20 seconds vs. 30 seconds ± 10 seconds, P < .001).

Conclusions:

We found substantial grading correlation between the original and the newly modified House‐Brackmann scales. Because of specific zonal and synkinesis scoring, the modified scale took longer to score. Laryngoscope, 2011
Some characteristics of organic soils irrigated with municipal wastewater
Authors: Brzezińska M. , Sokołowska Z. , Alekseeva T. , Alekseev A. , Hajnos M. , Szarlip P.
Published: August 2010

Soil irrigation with wastewater (WW) gives the opportunity to solve the problems of its disposal, final purification or reuse. Many studies have examined mineral soils upon continued WW application. The aim of this paper was to examine the properties of organic soils 3 years after WW application was discontinued. Peat‐muck soil planted with Populus spp. or Salix spp., and mineral‐muck soil under grasses were irrigated for 4 years with municipal WW at a low (comparable with intensive NPK fertilization) and high WW rate (600 and 1200 mm yearly, respectively). Soils were analysed for organic matter (OM), pH, bulk density (BD), water holding capacity (WHC), P2O5, Fe2O3, Al2O3, MnO, Zn, Pb, Cu, Cr, magnetic susceptibility (MS) and dehydrogenase and catalase activities. The results were compared with control soils which have never received WW. The study showed that only P2O5, MnO and catalase activity (CA) were significantly affected by former WW application. On average, P2O5 increased by 30 per cent, whereas MnO decreased by 35 per cent with no differences between the two WW rates. CA decreased by 18 per cent at the high WW rate. Most of tested characteristics were determined by soil type. The peat‐muck soil showed higher OM, WHC, P2O5, MnO, Pb and CA than mineral‐muck soil and lower BD, MS, Fe2O3, Al2O3 and Cr. Soil depth influenced Fe2O3, MnO, Zn, MS and enzyme activities, while basic soil properties (OM, pH, BD, WHC and P2O5) were not changed by soil depth. Heavy metals (Zn, Cr, Cu and Pb) were below upper permissible limits. Copyright © 2010 John Wiley & Sons, Ltd.
Occult hepatitis B virus infection of donor and recipient origin after liver transplantation despite nucleoside analogue prophylaxis
Authors: Cheung Cindy Ka Yee , Lo Chung Mau , Man Kwan , Lau George Ka Kit
Published: August 2010

Liver grafts from donors positive for antibody to hepatitis B core antigen (anti-HBc) may be used for transplantation in patients with hepatitis B virus (HBV)–related liver disease, and an occult HBV infection may develop from either source. Liver biopsy was performed for 31 patients who remained seronegative for hepatitis B surface antigen for a median of 44.5 months (range = 13.6-126.4 months) and received nucleoside analogue prophylaxis post-transplant. Nineteen of these recipients (61%) had received anti-HBc–positive grafts. Intrahepatic total HBV DNA and covalently closed circular DNA (cccDNA) levels were quantified, and the sequence was analyzed. Intrahepatic total HBV DNA and cccDNA were detectable in 26 (84%) and 16 (52%) of the 31 recipients, respectively, and they were more common when the donor was positive for anti-HBc (95% versus 67%, P = 0.038). The intrahepatic HBV DNA level correlated with the recipient pretransplant serum HBV DNA level (P = 0.06), and the intrahepatic HBV cccDNA level correlated with the donor intrahepatic HBV cccDNA level (P = 0.06). A phylogenetic analysis of the isolated HBV DNA sequence revealed HBV infections of both donor and recipient origins. In conclusion, an occult HBV infection after liver transplantation can originate from both the donor and recipient despite prolonged nucleoside analogue prophylaxis. The presence of intrahepatic HBV cccDNA is attributable more to the persistence of preexisting intrahepatic HBV cccDNA from a donor with previous exposure. Liver Transpl 16:1314-1323, 2010. © 2010 AASLD.
Post–liver transplant cholestatic hepatitis C: A systematic review of clinical and pathological findings and application of consensus criteria
Authors: Narang Tarun K. , Ahrens Will , Russo Mark W.
Published: August 2010

Liver transplantation is currently the only definitive modality for the treatment of end-stage liver disease due to chronic hepatitis C. However, recurrent hepatitis C after liver transplantation is nearly universal. Cirrhosis may develop in 20% of recipients within 5 years, and recurrent hepatitis C may lead to graft failure, retransplantation, and even death. A subset of recipients may develop post–liver transplant cholestatic hepatitis C (PLTCHC), which is characterized by cholestasis, hepatocyte ballooning, and rapid progression to graft failure. We present a systematic review of PLTCHC that is focused on hepatitis C–infected liver transplant recipients. We compare the pathological definitions of PLTCHC, clinical factors, management strategies, and outcomes reported in studies. We found differences among studies in the types of histological criteria used to diagnose PLTCHC during liver biopsy and in the types of clinical information provided. Three of the 12 studies published after 2003 used the definition of PLTCHC published by the first International Liver Transplantation Society expert panel consensus conference on liver transplantation and hepatitis C. We propose that studies on PLTCHC use the consensus criteria for diagnosis and suggest clinical information that should be provided in future studies with the goal of improving our understanding and management of this deadly disease. Liver Transpl 16:1228-1235, 2010. © 2010 AASLD.
Alemtuzumab induction in non-hepatitis C positive liver transplant recipients
Authors: Levitsky Josh , Thudi Kavitha , Ison Michael G. , Wang Edward , Abecassis Michael
Published: August 2010

Limited data exist for the use of alemtuzumab (AL) induction in liver transplantation (LT) recipients. We compared the outcomes of hepatitis C virus-negative LT recipients who received AL induction followed by tacrolimus and mycophenolate mofetil without steroids to cohort who received no AL induction, tacrolimus, and a steroid taper. Fifty-five AL-induced recipients were compared to 85 non-AL-induced recipients with similar characteristics. Two-year patient survival (80% versus 88.2%, P = 0.0665) and graft survival (76.4% versus 82.4%, P = 0.1792) were not significantly different between the AL and non-AL groups, respectively. Other outcomes, including acute rejection (20% versus 30.3%), renal dysfunction (creatinine levels: 1.3 ±0.3 versus 1.4 ± 0.6 mg/dL), and immunosuppressant monotherapy (29.1% versus 44.3%), were not significantly different between the AL and non-AL groups, respectively (P > 0.05). The number of rejection episodes (12 versus 42, P = 0.02) and the number of patients with new-onset hypertension (3 versus 15, P = 0.03) were lower in the AL group, although the incidence of all posttransplant infections was higher with AL (63.6% versus 44.3%, P = 0.03), primarily because of an increase in viral infections. In conclusion, a steroid-free AL induction regimen was associated with less hypertension and rejection but with more infectious complications; thus, the overall benefit of AL induction in LT recipients is called into question. Liver Transpl 17:32-37, 2011. © 2011 AASLD.
Polymeric Micelles with Tunable Channels
Authors: Ma Rujiang , Shi Linqi
Published: August 2010

This article describes a novel type of polymeric micelles with tunable channels (PMTC), which are usually composed of a common core and a mixed shell of two different kinds of polymer chains with at least one of them being stimuli‐responsive. Phase separation of the mixed shell upon stimuli results in channels between the micelle core and the outer milieu for controlling mass exchange. Channel‐modulated drug release and catalysis based on PMTC are discussed. The PMTC have peculiar merits including facile manipulation of drug release rate and catalytic velocity, remarkable restraint of burst drug release, and efficient prevention of degradation of the micelle core due to their unique structure. Finally, prospects and challenges of PMTC are reviewed.

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Face‐to‐Face Alignment of Porphyrin/Fullerene Nanowires Linked by Axial Metal Coordination
Authors: Xu Hua , Zheng Jianyu
Published: August 2010

A general approach to construct one‐dimensional face‐to‐face alignment of porphyrin/fullerene nanowires has been developed. This system uses extended trans‐dihydroxotin(IV) porphyrin and trans‐dicarboxylate‐substituted [60]fullerenoacetic diacid compounds. The nanowires are arranged in regular one‐dimensional linear arrays with lengths in the range 50–300 nm. In the nanowires, each fullerene unit is axially coordinated to the central metal ion of a Sn(IV) porphyrin unit via Sn‐carboxylate coordination and forms a face‐to‐face aligned structure. The synthesis and the hierarchical structure of nanowires have been investigated. They could have potential applications for photoelectronic devices, organic solar cells and so on.

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π‐Conjugated Polymers Consisting of Isothianaphthene and Dialkoxy‐p‐phenylene Units: Synthesis, Self‐Assembly, and Chemical and Physical Properties
Authors: Yamamoto Takakazu , Usui Motoaki , Ootsuka Haruki , Iijima Takayuki , Fukumoto Hiroki , Sakai Yoshimasa , Aramaki Shinji , Yamamoto Hiroshi M. , Yagi Takehiko , Tajima Hiroyuki , Okada Taku , Fukuda Takashi , Emoto Akira , Ushijima Hirobumi , Hasegawa Miki , Ohtsu Hideki
Published: August 2010

A series of π‐conjugated alternating copolymers consisting of Th‐ITN‐Th and p‐C6H2(OR)2 units were synthesized. XRD indicated that the copolymers assume an interdigitation packing mode, and UV‐Vis spectra revealed a strong tendency for self‐assembly. Upon molecular assembly of the copolymer, the UV‐Vis absorption shifted by about 100 nm to a longer wavelength from that of the single molecule. The copolymers underwent electrochemical oxidation (or p‐doping) and reduction (or n‐doping) at 0.2 and −2.0 V versus Ag+/Ag, respectively. A p‐doped copolymer film showed an electrical conductivity of 182 S · cm−1, and the temperature dependence of electrical conductivity was measured. The copolymer showed piezochromism and served as a p‐channel material for a field‐effect transistor.

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Fibrils Formed by Dendron‐b‐oligoaniline‐b‐dendron Block Co‐oligomer
Authors: Xiong Wei , Wang Hanfu , Han Yanchun
Published: August 2010

Novel dendritic triblock co‐oligomer (14G2A3) consisting of ester dendrons and aniline oligomer was synthesized and found to self‐assemble into fibrils in THF. Studies reveal that the formation of the fibrils originates from both of the amphiphilic interactions between the ester dendrons and oligoaniline, as well as the intermolecular π‐π stacking among oligoanilines. The shape effect of dendrons on molecular packing was comparatively analyzed with packing parameter against its linear analogous compound. At the same time, the driving forces that dominate the final aggregating state of the block oligomer were separately investigated using the bulky‐group protecting method, which allows release of the intermolecular π‐π stacking of oligoaniline in a controlled manner. Results show that both the introduction of dendrons and the intermolecular π‐π stacking will increase the packing parameter of the block oligomer and, consequently, cause the self‐assembly morphology to evolve step by step from micelles to vesicles and finally to fibrils. The fibrils can form complexes with SWNTs to increase solubility in THF. The effective fluorescence quenching accompanied also opens a gate for the block co‐oligomer to have potential applications in organic electronic devices.

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Fast human brain magnetic resonance responses associated with epileptiform spikes
Authors: Sundaram Padmavathi , Wells William M. , Mulkern Robert V. , Bubrick Ellen J. , Bromfield Edward B. , Münch Mirjam , Orbach Darren B.
Published: August 2010

Neuronal currents produce local electromagnetic fields that can potentially modulate the phase of the magnetic resonance signal and thus provide a contrast mechanism tightly linked to neuronal activity. Previous work has demonstrated the feasibility of direct MRI of neuronal activity in phantoms and cell culture, but in vivo efforts have yielded inconclusive, conflicting results. The likelihood of detecting and validating such signals can be increased with (i) fast gradient‐echo echo‐planar imaging, with acquisition rates sufficient to resolve neuronal activity, (ii) subjects with epilepsy, who frequently experience stereotypical electromagnetic discharges between seizures, expressed as brief, localized, high‐amplitude spikes (interictal discharges), and (iii) concurrent electroencephalography. This work demonstrates that both MR magnitude and phase show large‐amplitude changes concurrent with electroencephalography spikes. We found a temporal derivative relationship between MR phase and scalp electroencephalography, suggesting that the MR phase changes may be tightly linked to local cerebral activity. We refer to this manner of MR acquisition, designed explicitly to track the electroencephalography, as encephalographic MRI (eMRI). Potential extension of this technique into a general purpose functional neuroimaging tool requires further study of the MR signal changes accompanying lower amplitude neuronal activity than those discussed here. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
Robust 2D phase correction for echo planar imaging under a tight field‐of‐view
Authors: Xu Dan , King Kevin F. , Zur Yuval , Hinks R. Scott
Published: August 2010

Nyquist ghost artifacts are a serious issue in echo planar imaging. These artifacts primarily originate from phase difference between even and odd echo images and can be removed or reduced using phase correction methods. The commonly used 1D phase correction can only correct phase difference along readout axis. 2D correction is, therefore, necessary when phase difference presents along both readout and phase encoding axes. However, existing 2D methods have several unaddressed issues that affect their practicality. These issues include uncharacterized noise behavior, image artifact due to unoptimized phase estimation, Gibbs ringing artifact when directly applying to partial ky data, and most seriously a new image artifact under tight field‐of‐view (i.e., field‐of‐view slightly smaller than object size). All these issues are addressed in this article. Specifically, theoretical analysis of noise amplification and effect of phase estimation error is provided, and tradeoff between noise and ghost is studied. A new 2D phase correction method with improved polynomial fitting, joint homodyne processing and phase correction, compatibility with tight field‐of‐view is then proposed. Various results show that the proposed method can robustly generate images free of Nyquist ghosts and other image artifacts even in oblique scans or when cross‐term eddy current terms are significant. Magn Reson Med, 2010. © 2010 Wiley‐Liss, Inc.
A key management scheme for secure group communication using binomial key trees
Authors: Aparna R. , Amberker B. B.
Published: August 2010

Numerous emerging applications, such as teleconferencing, board meetings, pay‐per‐view and scientific discussions, rely on a secure group communication model. Scalable group rekeying is an important issue in the secure group communication model as the nature of the group is dynamic. The number of encryptions performed and rekey messages constructed should be minimized to carry out updating of the group key, and secure delivery of the group key should be carried out in an efficient manner. In this paper, we propose a new scheme to manage the secure group using the binomial key tree approach. In this scheme, the number of encryptions performed and rekey messages constructed during membership change are fewer compared to the scheme proposed by Wong and others. Further, it is not required to balance the tree after each membership change. We show that, for a large group, the average encryption cost and rekey message cost are independent of the size of the group for join operation and logarithmic in size of the group for leave operation. Hence our scheme is scalable. Copyright © 2010 John Wiley & Sons, Ltd.
Comparative study of two CPU router time management algorithms in cellular IP networks
Authors: Vidyarthi Deo Prakash , Anbar Mohammad
Published: August 2010

Providing good quality of service (QoS) in cellular IP networks is an important requirement for performance improvement of the cellular IP network. Resource reservation is one of the methods used in achieving this goal and is proven to be effective. The main resources to be reserved in a cellular IP network are bandwidth, buffer and central processing unit (CPU) cycles. Router CPU cycle is the time taken by the router to process the packet of the flow before forwarding it to the next router (hop). This paper proposes a model for CPU cycle optimization of routers for real‐time flows in a cellular IP network. The model applies both genetic algorithm (GA) and particle swarm optimization (PSO) as soft computing tools to optimize the CPU cycles and reduces the flow processing time at each router in the route taken by a flow. Simulation experiments illustrate a comparative study of the model.
Amphiphile polydimethylsiloxane‐based networks reinforced with in situ generated silica
Authors: Alexandru Mihaela , Cazacu Maria , Racles Carmen , Grigoras Cristian
Published: August 2010

Polydimethylsiloxanes, side functionalized in different degrees with chloromethyl groups, were reacted with 4,4′‐bipyridyl and crosslinking occurred by the formation of ionic (bipyridinium) groups. The reactions were carried out in a silica sol–gel system, and thus, two networks were generated simultaneously: amphiphile siloxane‐organic and silica networks. The samples, processed as films, were characterized by Fourier transform infrared spectroscopy to verify the occurrence of the crosslinking reactions. Different techniques were also used to evaluate the properties: differential scanning calorimetry for emphasizing the transitions, scanning electron microscopy, and atomic force microscopy for the evaluation of the morphology and surface topography. The modification of the film surface topography, which depends on the solvent polarity, was also emphasized. The sorption capacities of the water vapors and of liquid solvents (water and chloroform) were investigated, and the obtained values proved to be a function of the polar group's content. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Physical properties of epoxy resin/titanium dioxide nanocomposites
Authors: Polizos Georgios , Tuncer Enis , Sauers Isidor , More Karren L.
Published: August 2010

A polymeric nanocomposite system (nanodielectric) was fabricated, and its mechanical properties were determined. The fabricated nanocomposite was composed of low concentrations of monodispersed titanium dioxide (TiO2) nanoparticles and an epoxy resin specially designed for cryogenic applications. The monodispersed TiO2nanoparticles were synthesized in an aqueous solution of titanium chloride and polyethylene glycol and subsequently dispersed in a commercial‐grade epoxy resin (Araldite® 5808). Nanocomposite thin sheets were prepared at several weight fractions of TiO2. The morphology of the composites, determined by transmission electron microscopy, showed that the nanoparticles aggregated to form particle clusters. The influence of thermal processing and the effect of filler dispersion on the structure–property relationships were identified by differential scanning calorimetry and dynamic mechanical analysis at a broad range of temperatures. The effect of the aggregates on the electrical insulation properties was determined by dielectric breakdown measurements. The optical properties of the nanocomposites and their potential use as filters in the ultraviolet–visible (UV–vis) range were determined by UV–vis spectroscopy. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Interdiffusion analysis based on novel ultrasonic welding method with inserting interposed sheet
Authors: Zhang Guohong , Qiu Jianhui
Published: August 2010

The molecular movement process has been developed according to previous study on the novel ultrasonic welding method of inserting interposed sheet and its apparatus. Based on the classical reptation theory, a hauling theory of interdiffusion has been proposed which can accelerate molecular movement and interpenetration surprisingly. Hauling effect can promote the interdiffusion but has no effect on the interpenetration length. We involve a coefficient ku to modify the relationship between the reptation time before and diffusion time, which can be related to the relative displacement and friction coefficient among the molecular in terms of the equations. The surface roughness, welding time, and welding force have been experimented and resulted uniformly in which the diffusion has been accelerated from our experiments. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Degree of dispersion of polymeric compounds determined with terahertz time‐domain spectroscopy
Authors: Krumbholz N. , Hochrein T. , Vieweg N. , Radovanovic I. , Pupeza I. , Schubert M. , Kretschmer K. , Koch M.
Published: August 2010

Terahertz spectroscopy has been presented as a new technique for analyzing the degree of dispersion of polymeric compounds. It is a contact‐free and nondestructive technique that can also be used to monitor the filler content of compounds inline during the extrusion process as has already been presented elsewhere. The utilized terahertz frequency range bridges the infrared and the microwave region in the electromagnetic spectrum. Here, we present offline terahertz measurements and mechanical tests on injection molded specimens consisting of wood plastic composites with varying filler contents and different dispersion qualities. A clear linear relation between results of the terahertz measurements and mechanical tests has been found showing that terahertz spectroscopy is a powerful tool for analyzing polymeric compounding processes. POLYM. ENG. SCI., 2011. © 2010 Society of Plastics Engineers
Disulfiram is a DNA demethylating agent and inhibits prostate cancer cell growth
Authors: Lin Jianqing , Haffner Michael C. , Zhang Yonggang , Lee Byron H. , Brennen W. Nathaniel , Britton Justin , Kachhap Sushant K. , Shim Joong Sup , Liu Jun O. , Nelson William G. , Yegnasubramanian Srinivasan , Carducci Michael A.
Published: August 2010

BACKGROUND

The clinical success of the nucleoside analogs 5‐aza‐cytidine (5‐azaC) and 5‐aza‐2′deoxycytidine (5‐aza‐dC) as DNA methyltransferase (DNMT) inhibitors has spurred interest in the development of non‐nucleoside inhibitors with improved pharmacologic and safety profiles. Because DNMT catalysis features attack of cytosine bases by an enzyme thiol group, we tested whether disulfiram (DSF), a thiol‐reactive compound with known clinical safety, demonstrated DNMT inhibitory activity.

METHODS

Inhibition of DNMT1 activity by DSF was assessed using methyltransferase activity assays with recombinant DNMT1. Next, prostate cancer cell lines were exposed to DSF and assessed for: i) reduction of global 5‐methyl cytosine (5meC) content using liquid chromatography/tandem mass spectrometry (LC‐MS/MS); ii) gene‐specific promoter demethylation by methylation‐specific PCR (MSP); and iii) gene‐reactivation by real‐time RT‐PCR. DSF was also tested for growth inhibition using prostate cancer cell lines propagated in vitro in cell culture and in vivo as xenografts in nude mice.

RESULTS

Disulfiram showed a dose‐dependent inhibition of DNMT1 activity on a hemimethylated DNA substrate. In prostate cancer cells in culture, DSF exposure led to reduction of global genomic 5meC content, increase in unmethylated APC and RARB gene promoters, and associated re‐expression of these genes, but did not significantly alter prostate‐specific antigen (PSA) expression. DSF significantly inhibited growth and clonogenic survival of prostate cancer cell lines in culture and showed a trend for reduced growth of prostate cancer xenografts.

CONCLUSIONS

Disulfiram is a non‐nucleoside DNMT1 inhibitor that can reduce global 5meC content, reactivate epigenetically silenced genes, and significantly inhibit growth in prostate cancer cell lines. Prostate 77:333–343, 2011. © 2010 Wiley‐Liss, Inc.
Measuring disorder in graphene with the G and D bands
Authors: Jorio Ado , Ferreira Erlon H. Martins , Moutinho Marcus V. O. , Stavale Fernando , Achete Carlos A. , Capaz Rodrigo B.
Published: August 2010

Here we analyse the evolution of the disorder induced D‐band (∼1350 cm−1) and of the first‐order allowed G‐band (∼1584 cm−1) in the Raman spectra of ion bombarded graphene. By increasing the bombardment time, we increase the disorder and, consequently, decrease the average distance (LD) between defects. We describe how the intensity, full width at half maximum (FWHM) and integrated area vary for the D and G bands as a function of LD. Finally, we compare the evolution of the intensity ratio ID/IG and of the integrated area ratio AD/AG between the D and G bands as a method for quantifying disorder in graphene. For practical use and inter‐laboratorial comparison, the authors advise using the intensity ratio for a more suitable measure for analysing defect density.
A mollified ensemble Kalman filter
Authors: Bergemann Kay , Reich Sebastian
Published: August 2010

It is well recognized that discontinuous analysis increments of sequential data assimilation systems, such as ensemble Kalman filters, might lead to spurious high‐frequency adjustment processes in the model dynamics. Various methods have been devised to spread out the analysis increments continuously over a fixed time interval centred about the analysis time. Among these techniques are nudging and incremental analysis updates (IAU). Here we propose another alternative, which may be viewed as a hybrid of nudging and IAU and which arises naturally from a recently proposed continuous formulation of the ensemble Kalman analysis step. A new slow–fast extension of the popular Lorenz‐96 model is introduced to demonstrate the properties of the proposed mollified ensemble Kalman filter. Copyright © 2010 Royal Meteorological Society
Assessing atmospheric predictability on Mars using numerical weather prediction and data assimilation
Authors: Rogberg P. , Read P. L. , Lewis S. R. , Montabone L.
Published: August 2010

The intrinsic and practical predictability of the Martian atmosphere is determined by use of a comprehensive numerical circulation model and ensemble forecasting techniques. Initial conditions were derived for various seasons of the Martian climate from newly available assimilations of global observations of temperature and dust optical depth in the Martian atmosphere, obtained by the Thermal Emission Spectrometer (TES) instrument on the Mars Global Surveyor orbiter. A range of initial value forecasts were obtained and the growth rate of forecast errors measured against the assimilated re‐analysis were determined as a function of season during the period from the late Martian year 24 to early 27 (from May 1999 to August 2004). The intra‐ensemble growth rates confirm earlier stand‐alone model results, indicating that internal baroclinic transients lead to significant chaotic growth of model ‘error’ on time‐scales of 3–10 sols only during Northern Hemisphere autumn and winter seasons. At other seasons, ensembles retain coherence at least over several tens of sols. Imperfections in dust distribution and coupling with other aerosols can lead to large errors in the dust field when it evolves rapidly. Owing to the very short time‐scale on Mars, these errors can lead to rapid divergence of the entire ensemble from the observed atmospheric state. These results demonstrate the importance of even relatively small errors in the aerosol fields and so in the computed radiative balance of the Martian atmosphere for deterministic forecasts throughout the Martian year, including times at which baroclinic transients are inactive. Copyright © 2010 Royal Meteorological Society
Modeling of plastic scintillation composition of poly(methyl methacrylate)–naphthalene–POPOP
Authors: Irgibaeva Irina Smailovna , Barashkov Nikolay , Aldongarov Anuar , Mantel Artur , Barashkova Irina
Published: August 2010

Geometry optimizations of monomers were carried out with the use of Becke's three‐parameter hybrid method with Lee, Yang, and Parr (B3LYP) gradient‐corrected correlation functional and the standard 6‐31G(d) basis set. UV–vis spectra of different naphthalene‐POPOP complexes using ZINDO/S method were calculated. In these complexes, poly(methyl methacrylate) effect on chromophores was neglected and chromophores were staked. Analyzing available experimental data and obtained theoretical results, the most probable complex structure is determined. Molecular model of POPOP and naphthalene dimer corresponds to this structure. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Theoretical assessment of new molecules for second‐order nonlinear optics
Authors: Labidi Sofiane Nouar , Kanoun Mohammed Benali , De Wergifosse Marc , Champagne Benoît
Published: August 2010

The polarizabilities and first hyperpolarizabilities of nine recently synthesized compounds have been calculated ab initio to assess the effects of basis sets, of electron correlation (at the MP2 level), of frequency dispersion, and of the solvent within the polarizable continuum model, as well as to address structure–property relationships. These calculations confirm that moderate‐size basis sets like 6‐31+G* or 6‐311+G* are enough to provide accurate estimates of the polarizabilities and first hyperpolarizabilities for these systems build from the combination of π‐conjugated linkers with donor/acceptor moieties. They describe the specific behavior of the hyper‐Rayleigh scattering (HRS) first hyperpolarizability and of its depolarization ratio as a function of the incident light frequency. Then, these calculations exemplify the large impact of including electron correlation and solvent effects on the first hyperpolarizabilities, and the crucial issue in view of optimizing the NLO compounds, that these effects are strongly system dependent. Finally, this theoretical investigation draws attention to the interplay between several second‐order nonlinear optical molecular responses: the norm of the first hyperpolarizability (β), the projection on the dipole moment (β//), which can be obtained from electric field–induced second‐harmonic generation measurements, and the HRS response (βHRS). © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
Computed stabilities in metallofullerene series: Al@C82, Sc@C82, Y@C82, and La@C82
Authors: Slanina Zdeněk , Uhlík Filip , Lee Shyi‐Long , Adamowicz Ludwik , Akasaka Takeshi , Nagase Shigeru
Published: August 2010

This article reports computations for Al@C82, Sc@C82, Y@C82, and La@C82 based on encapsulation into the IPR (isolated pentagon rule) C2v C82 cage. Their structural and bonding features are also used for evaluations of the relative production yields, employing the encapsulation Gibbs‐energy terms and saturated metal pressures. The results can be well related to the ionization potentials of the free metal atoms and thus also rationalized. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011
Stability and protonation of multielectron systems: The concept of proton affinity. I. Vague limits
Authors: Kryachko Eugene S.
Published: August 2010

The present work is a kind of a “polyphonic” collection of thoughts about the relationship between the stability of multi‐electron systems and the protonation. The intricacy of the protonation sites and the protonated states that are absorbed into the concept of the proton affinity is discussed, particularly addressing its range of validity. This work can also be considered as an attempt to have a look “at different angles” at one of the most important molecular processes that occur in nature and that are reflected in our mirror of the perception of nature. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2010
How to solve the problem of dynamical correlation of electrons in the ground state helium atom?
Authors: Ignatiev V. D.
Published: August 2010

It is found that, for the ground state helium atom, a stationary wave function obtained from the stationary Shrödinger equation for one of the interacting electrons is much more physically meaningful than that from the equation for both electrons. Hamiltonian includes one‐electron Laplacian and operators of electron–nuclear attraction and electron–electron repulsion. Corresponding energy is equal to the first ionization potential. This approach recovers evident insufficiency of summation of potential energies accompanied by determination of kinetic energy from the virial relation. It appears that the kinetic energy must be determined independently. The kinetic energy of both electrons lowers due to inertia of the electron movement. It demands for a time‐resolved consideration of the electron movement in helium. The total energy cannot be minimized in one step, that is, by help of a single stationary wave function. It should be minimized with means of two wave functions in accord with experimental sequential ionization. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011