bluuebunny/crossref_metadata_2025 huggingface dataset:
Infrared Spectroscopy of Dioxouranium(V) Complexes with Solvent Molecules: Effect of Reduction
Authors: Groenewold Gary S. , Van Stipdonk Michael J. , de Jong Wibe A. , Oomens Jos , Gresham Garold L. , McIlwain Michael E. , Gao Da , Siboulet Bertrand , Visscher Lucas , Kullman Michael , Polfer Nick
Published: May 2008

UO2+–solvent complexes having the general formula [UO2(ROH)]+ (R=H, CH3, C2H5, and n‐C3H7) are formed using electrospray ionization and stored in a Fourier transform ion cyclotron resonance mass spectrometer, where they are isolated by mass‐to‐charge ratio, and then photofragmented using a free‐electron laser scanning through the 10  μm region of the infrared spectrum. Asymmetric O=U=O stretching frequencies (ν3) are measured over a very small range [from ∼953 cm−1 for H2O to ∼944 cm−1 for n‐propanol (n‐PrOH)] for all four complexes, indicating that the nature of the alkyl group does not greatly affect the metal centre. The ν3 values generally decrease with increasing nucleophilicity of the solvent, except for the methanol (MeOH)‐containing complex, which has a measured ν3 value equal to that of the n‐PrOH‐containing complex. The ν3 frequency values for these U(V) complexes are about 20 cm−1 lower than those measured for isoelectronic U(VI) ion‐pair species containing analogous alkoxides. ν3 values for the U(V) complexes are comparable to those for the anionic [UO2(NO3)3]− complex, and 40–70 cm−1 lower than previously reported values for ligated uranyl(VI) dication complexes. The lower frequency is attributed to weakening of the OUO bonds by repulsion related to reduction of the U metal centre, which increases electron density in the antibonding π* orbitals of the uranyl moiety. Computational modelling of the ν3 frequencies using the B3LYP and PBE functionals is in good agreement with the IRMPD measurements, in that the calculated values fall in a very small range and are within a few cm−1 of measurements. The values generated using the LDA functional are slightly higher and substantially overestimate the trends. Subtleties in the trend in ν3 frequencies for the H2O–MeOH–EtOH–n‐PrOH series are not reproduced by the calculations, specifically for the MeOH complex, which has a lower than expected value.
Oncotic colpocytology stained with Harris–Shorr in the observation of vaginal microorganisms
Authors: Storti‐Filho Agenor , Estivalet Svidizinski Terezinha Inez , da Silva Souza Robson José , de Mello Ione Cristina Jorge , da Costa Souza Paola , Lopes Consolaro Marcia Edilaine
Published: May 2008

The purpose of this work was to evaluate the efficacy of oncotic colpocytology stained with Harris–Shorr in the identification of the cervicovaginal microflora and infectious agents. Results of microbiologic evaluation carried out in colpocytology exams, bacterioscopy (Gram), and direct exams of 2,017 women aged from 13 to 80 years were compared. Of these, 83.1% agreed between cytology and Gram, 3.6% partially agreed, and 12.8% disagreed. The predominant microflora was of lactobacilli (63.3%), followed by mixed flora (32.1%). The results of sensitivity to lactobacilli were 96.1% and to mixed flora 88.0%; the specificity values were 91.2 and 92.0%, respectively. Colpocytology detected all the instances of trichomoniasis observed at direct exam (0.6%). The most frequent infectious agents were of candidiasis (14.8%, sensitivity 80.3%) and bacterial vaginosis (11.9%, sensitivity 68.1%). Thus, Harris–Shorr stained cytology was shown to be an excellent diagnostic method for T. vaginalis, lactobacilli, mixed flora, and candidiasis. Diagn. Cytopathol. 2008;36:358–362. © 2008 Wiley‐Liss, Inc.
Virtual microscopy: An educator's tool for the enhancement of cytotechnology students' locator skills
Authors: Stewart Jimmie , Bevans‐Wilkins Kristen , Bhattacharya Abhik , Ye Changhong , Miyazaki Kayo , Kurtycz Daniel F. I.
Published: May 2008

Virtual microscopy (VM) is being utilized as an educational tool in many areas of pathology. The aim of this study is to analyze the locator and diagnostic skills of cytotechnology students by using the Aperio T3 ScanScope®, and examine VM's viability as an educational tool in cytotechnology.

Ten validated cytology slides were digitized and reviewed by three senior cytotechnologist instructors. Each technologist made annotations indicating diagnostic areas on the virtual slide. A subset of the slides was used for locator skill evaluation. Cytotechnology students examined a pristine copy of the virtual slide and made annotations for comparison to those made by experienced instructors. Annotations of the subset were then scored based on the degree of correlation between students and cytotechnologists. A cytopathologist performed a final review of the students' marks; points were then added or subtracted based on this interpretation.

Students were graded based on their correlation to senior cytotechnologists. A statistical analysis using modified interrater calculations ranked the students as to locator ability, producing illuminating results.

This study shows that VM has promise as a cytotechnology educational tool by allowing the instructor to evaluate students' locator and diagnostic abilities. We have attempted to implement a simple scoring system for evaluation of locator skills where students are compared versus expert cytotechnologists. We anticipate further technological improvements as the products mature. Diagn. Cytopathol. 2008;36:363–368. © 2008 Wiley‐Liss, Inc.
Diagnostic terminology and morphologic criteria for cytologic diagnosis of thyroid lesions: A synopsis of the National Cancer Institute Thyroid Fine‐Needle Aspiration State of the Science Conference
Authors: Baloch Zubair W. , LiVolsi Virginia A. , Asa Syl L. , Rosai Juan , Merino Maria J. , Randolph Gregory , Vielh Philippe , DeMay Richard M. , Sidawy Mary K. , Frable William J.
Published: May 2008

The National Cancer Institute (NCI) sponsored the NCI Thyroid Fine‐needle Aspiration (FNA) State of the Science Conference on October 22–23, 2007 in Bethesda, MD. The two‐day meeting was accompanied by a permanent informational website and several on‐line discussion periods between May 1 and December 15, 2007 (http://thyroidfna.cancer.gov). This document summarizes matters regarding diagnostic terminology/classification scheme for thyroid FNA interpretation and cytomorphologic criteria for the diagnosis of various benign and malignant thyroid lesions. (http://thyroidfna.cancer.gov/pages/info/agenda/). Diagn. Cytopathol. 2008;36:425–437. © 2008 Wiley‐Liss, Inc.
Temporal changes in suspended sediment transport in a gullied loess basin: the lower Chabagou Creek on the Loess Plateau in China
Authors: Fang H. Y. , Cai Q. G. , Chen H. , Li Q. Y.
Published: May 2008

Suspended sediment dynamics are still imperfectly understood, especially in the loess hilly region on the Loess Plateau, with strong temporal variability, where few studies heretofore have been conducted. Using a dataset up to eight years long in the Lower Chabagou Creek, the variability in suspended sediment load at different temporal scales (within‐flood variability, monthly–seasonal and annual) is analyzed in this paper. The results show that, on the within‐flood scale, most of the sediment peaks lag behind peak discharges, implying that slope zones are the main sediment source area; independent of the occurring sequences of the peaks of sediment and discharge, all the events could present an anti‐clockwise hysteresis loop resulting from the abundant material and the influence of hyperconcentrated flows on suspended sediment concentration. At monthly and seasonal scales, there is a ‘store–release’ process, i.e. sediment is prepared in winter, spring and late autumn, and exported in summer and early autumn. At the annual scale, the high variability in concentration and sediment yield are highly correlated with water yield, resulting from the number and magnitude of floods recorded yearly, and almost all the suspended load is transported during these events. Copyright © 2008 John Wiley & Sons, Ltd.
Video‐based gravel transport measurements with a flume mounted light table
Authors: Zimmermann André E. , Church Michael , Hassan Marwan A.
Published: May 2008

The study of bedload transport processes is constrained by an inability to monitor the mass, volume and grain size distribution of sediment in transport at high temporal frequencies. Building upon a previously published design, we have integrated a high‐resolution (1392 × 1024 pixels) video camera with a light table to continuously capture images of 2–181 mm material exiting a flume. The images are continuously recorded at a rate of 15 to 20 frames per second and are post‐processed using LabView(™) software, yielding continuous grain‐size‐specific transport information on a per second basis. The video capture rate is sufficient to record multiple images of each grain leaving the flume so that particle velocities can be measured automatically. No manual image processing is required.

After calibration the method is accurate and precise for sediment in the 2 mm through to 45 mm grain size classes compared with other means of measuring bedload. Based on a set of validation samples, no statistically significant difference existed between the D10, D16, D25, D50, D75, D84, D90 and D95 determined by sieving captured samples and the Di values determined with the system. On average the system overpredicted transport by 4 per cent (n = 206, SD = 42%). This error can be corrected easily by simply weighing the mass of sediment that leaves the flume. The technology is relatively inexpensive and provides high‐resolution data on coarse sediment transport out of a flume. Copyright © 2008 John Wiley & Sons, Ltd.
Controls on sediment evacuation from glacially modified and unmodified catchments in the eastern Sierra Nevada, California
Authors: Dühnforth Miriam , Densmore Alexander L. , Ivy‐Ochs Susan , Allen Philip A.
Published: May 2008

The degree of glacial modification in small catchments along the eastern Sierra Nevada, California, controls the timing and pattern of sediment flux to the adjacent fans. There is a close relationship between the depth of fan‐head incision and the pattern and degree of Late Pleistocene catchment erosion by valley glaciers; catchments with significant glacial activity are associated with deeply incised fan heads, whereas fans emerging from glacially unmodified catchments are unincised. We suggest that the depth of fan‐head incision is controlled by the potential for sediment storage during relatively dry ice‐free periods, which in turn is related to the downstream length of the glacially modified valley and creation of accommodation through valley floor slope lowering and glacial valley overdeepening and widening. Significant storage in glacially modified basins during ice‐free periods leads to sediment supply‐limited conditions at the fan head and causes deep incision. In contrast, a lack of sediment trapping allows quasi‐continuous sediment supply to the fan and prevents incision of the fan head. Sediment evacuation rates should thus show large variations in glacially modified basins, with major peaks during glacial and lows during interglacial or ice‐free periods, respectively. In contrast, sediment removal from glacially unmodified catchments in this type of setting should be free of this effect, and will be dominated instead by short‐term variations, modulated for example by changes in vegetation cover or storm frequency. This distinction may help improve our understanding of long‐term sediment yields as a measure of erosional efficiency. Copyright © 2008 John Wiley & Sons, Ltd.
“Talking About My Generation”
Authors: Unterstell Rembert
Published: May 2008

The Senior Research Group in Berlin tests household appliances and high‐tech gadgets to promote the development of products better suited to the needs of the 55‐plus generation
Estimation of suspended sediment sources using 137Cs and 210Pbex in unmanaged Japanese cypress plantation watersheds in southern Japan
Authors: Mizugaki Shigeru , Onda Yuichi , Fukuyama Taijiro , Koga Satoko , Asai Hiroki , Hiramatsu Shinya
Published: May 2008

To analyse suspended sediment sources in unmanaged Japanese cypress plantation watersheds, field measurements and fingerprinting of the suspended sediment was conducted in the Shimanto River basin in southern Japan. For sediment fingerprinting, 137Cs and 210Pbex were detected by means of gamma‐ray spectrometry in the surface soil of the forest floor, stream bank and truck trail and mobilized sediment by interrill erosion. The 137Cs and 210Pbex activities associated with the forest floor materials were considerably higher than those of the stream bank and truck trail. The 137Cs and 210Pbex activities associated with the suspended sediment were found to vary with the sampling period. Evidently, the suspended sediment can comprise materials generated from the forest floor by interrill erosion and those from the truck trail and/or stream bank. The multivariate sediment‐mixing model using 137Cs and 210Pbex showed that the contribution of the forest floor varied periodically, ranging from 23–56% in the Hinoki 156 subwatershed and from 18–85% in the Hinoki 155 subwatershed. The difference in the average contribution of the forest floor between Hinoki 156 (46%) and Hinoki 155 (69%) may relate to the presence of truck trail networks in the watershed. The truck trail network can play roles of sediment source and pathway for sediment from forest floor to stream channel due to the concentrated overland flow on the truck trail during heavy rainfall events. These results indicate that the forest floor should be recognized as a major source of suspended sediment in unmanaged Japanese cypress plantation watersheds. Copyright © 2008 John Wiley & Sons, Ltd.
Various components of the insulin‐like growth factor system in tumor tissue, cerebrospinal fluid and peripheral blood of pediatric medulloblastoma and ependymoma patients
Authors: de Bont Judith M. , van Doorn Jaap , Reddingius Roel E. , Graat Gerard H.M. , Passier Monique M.C.J. , den Boer Monique L. , Pieters Rob
Published: May 2008

The insulin‐like growth factor (IGF) system plays an important role in neuronal development and may contribute to the development of brain tumors. In this study, we studied mRNA expression levels of IGFs, insulin‐like growth factor binding proteins (IGFBPs) and insulin‐like growth factor receptors (IGFRs) in 27 pediatric medulloblastomas, 13 pediatric ependymomas and 5 control cerebella. Compared to normal cerebellum, mRNA levels of IGFBP‐2 and IGFBP‐3 were significantly increased in medulloblastomas and ependymomas. IGFBP‐2 expression was indicative of poor prognosis in medulloblastomas, whereas IGFBP‐3 mRNA levels were especially high in anaplastic ependymomas. IGFBP‐5 and IGF‐II mRNA levels were significantly increased in ependymomas compared to control cerebellum. Protein expression levels of IGFs and IGFBPs were analyzed in the cerebrospinal fluid (CSF) of 16 medulloblastoma, 4 ependymoma and 23 control patients by radioimmuno assay to determine whether they could be used as markers for residual disease after surgery. No aberrant CSF protein expression levels were found for ependymoma patients. In medulloblastoma patients, the IGFBP‐3 protein levels were significantly higher than in ependymoma patients and controls. Moreover, enhanced levels of proteolytic fragments of IGFBP‐3 were found in the CSF of medulloblastoma patients, being in concordance with a significantly increased IGFBP‐3 proteolytic activity in the CSF of these patients. In conclusion, our data suggest that the IGF system is of importance in pediatric medulloblastomas and ependymomas. Larger studies should be conducted to validate the predictive values of the levels of intact IGFBP‐3 and proteolytic fragments in CSF in the follow‐up of medulloblastomas. © 2008 Wiley‐Liss, Inc.
Attachment disorders in family and social context
Authors: Zeanah Charles H. , Smyke Anna T.
Published: May 2008

Serious disturbances of attachment in young children have been increasingly studied in the past decade as they arise in atypical rearing environments. The purpose of this review is to provide an update on recent findings and to consider their implications. Research on children raised in institutions, children adopted out of institutions, and young children who have experienced neglect in families is considered. Reactive attachment disorder may be identified reliably in a minority of children being raised in severely neglectful environments. The emotionally withdrawn/inhibited pattern and the indiscriminately social/disinhibited pattern arise in similar conditions of risk, but respond differently to intervention and appear to have different correlates. Much has been learned about the emotionally withdrawn/inhibited pattern of reactive attachment disorder and the indiscriminately social/disinhibited pattern. Much less is known about so‐called secure base distortions or relational disorders of attachment.
The clinical relevance of infancy: A progress report
Authors: Stern Daniel
Published: May 2008

In the past few decades, findings from infant observations have played a key role in the following selected areas: (a) The emphasis now is on interpersonal and intersubjective processes rather than on intrapsychic processes. This is a paradigm shift towards a two‐person psychology. (b) The elaboration of the attachment domain has reoriented our views of development and treatment. (c) The success of extended home‐visiting programs as a preventive measure for parents and infants at risk has brought an agonizing reappraisal of what makes prevention (and therapy) work. (d) By default, the baby's world is nonverbal. This has led to a productive reexploration of unconsciousness, especially the domain of implicit knowledge. For the future, the following are some of the areas of great promise: (a) Attachment, love and “holding” must be disentangled. (b) We must study how and when the mirror neuron system gets micro‐ and macroregulated. One is not always open to empathic reception. (c) The articulation between the nonverbal (implicit) with the verbal (explicit) needs far more study. (d) The nonspecific factors of psychotherapy seem to be the most important in bringing about change and prevention. We need a greater systematic study of the nonspecific. (e) The triad and quartet, and so on need further exploration. (f) There are many more, but the beauty of research is that you can't know where it will go next.
Does the portal of entry determine our view? Interfaces between dyadic and three‐way assessment of a clinical family transitioning to parenthood
Authors: Philipp Diane A. , Hervé Marie‐Joelle , Keren Miri
Published: May 2008

The purpose of this interface was to explore the influences of dyadic and three‐way observation on clinical assessment of young families. Three independent clinicians observed a clinically referred family using semistructured play paradigms, each with only a limited view of the family. One had only the data on dyadic interactions, the second only had data on the family triad, and the third observed both the dyads and the triad. Interactions were scored using standardized measures as well as the clinical impressions of the three practitioners. The various ports of entry yielded similar impressions in some instances, but each port also provided a richness of information not available from the other portal. Clinical implications are discussed, including not only the benefits of each port for assessment but also the implications for therapy in this case example.
Friction, lubrication, and polymer transfer between UHMWPE and CoCrMo hip‐implant materials: A fluorescence microscopy study
Authors: Crockett Rowena , Roba Marcella , Naka Marco , Gasser Beat , Delfosse Daniel , Frauchiger Vinzenz , Spencer Nicholas D.
Published: May 2008

The friction coefficients of CoCrMo sliding against UHMWPE and CoCrMo were measured in solutions of albumin and synovial fluid containing fluorescently labeled albumin. No fluorescence could be observed on the CoCrMo disc following incubation in labeled albumin or after sliding against CoCrMo. This was due to quenching of the fluorophore by the metal and indicated that a protein film thicker than 10 nm was not formed on the surface. A more complicated behavior was observed for UHMWPE sliding against CoCrMo. For each lubricating solution and at each load, a bimodal distribution of steady‐state friction values was observed, the friction coefficient either remaining constant or decreasing during the early stages of the measurement. As no quenching of the fluorophores occurred on the UHMWPE surface, the fluorescence labeling method could be used to reveal polyethylene (PE) transfer and to show that it correlates with the friction coefficient: Low friction coefficients corresponded to a low density of PE spots on the CoCrMo surface. In addition, it was found that the friction coefficients for UHMWPE sliding against CoCrMo in synovial fluid were not significantly different from those in phosphate‐buffered saline (PBS), but that the addition of albumin to PBS did cause a significant increase in the friction coefficient. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Enhancement of biocompatibility of 316LVM stainless steel by cyclic potentiodynamic passivation
Authors: Shahryari Arash , Omanovic Sasha , Szpunar Jerzy A.
Published: May 2008

Passivation of stainless steel implants is a common procedure used to increase their biocompatibility. The results presented in this work demonstrate that the electrochemical cyclic potentiodynamic polarization (CPP) of a biomedical grade 316LVM stainless steel surface is a very efficient passivation method that can be used to significantly improve the material's general corrosion resistance and thus its biocompatibility. The influence of a range of experimental parameters on the passivation/corrosion protection efficiency is discussed. The passive film formed on a 316LVM surface by using the CPP method offers a significantly higher general corrosion resistance than the naturally grown passive film. The corresponding relative corrosion protection efficiency measured in saline during a 2‐month period was 97% ± 1%, which demonstrates a very high stability of the CPP‐formed passive film. Its high corrosion protection efficiency was confirmed also at temperatures and chloride concentrations well above normal physiological levels. It was also shown that the CPP is a significantly more effective passivation method than some other surface‐treatment methods commonly used to passivate biomedical grade stainless steels. In addition, the CPP‐passivated 316LVM surface showed an enhanced biocompatibility in terms of preosteoblast (MC3T3) cells attachment. An increased thickness of the CPP‐formed passive film and its enrichment with Cr(VI) and oxygen was determined to be the origin of the material's increased general corrosion resistance, whereas the increased surface roughness and surface (Volta) potential were suggested to be the origin of the enhanced preosteoblast cells attachment. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Preparation and evaluation of chitosan‐ethylenediaminetetraacetic acid hydrogel films for the mucoadhesive transbuccal delivery of insulin
Authors: Cui Fuying , He Chunbai , He Miao , Tang Cui , Yin Lichen , Qian Feng , Yin Chunhua
Published: May 2008

This manuscript describes the development of a new porous, flexible bilaminated film for buccal protein administration by a simple and mild casting procedure. It consists of a mucoadhesive layer (chitosan‐ethylenediaminetetraacetic acid hydrogel film) containing protein drugs and an impermeable protective layer made of ethylcellose. The obtained mucoadhesive layer was characterized in terms of Fourier transform infrared spectroscopy, rheology, swelling, and mucoadhesion. Rheology results showed that chitosan‐ethylenediaminetetraacetic acid hydrogel (10:2) possessed the greatest degree of viscoelasticity and was well‐structured compared with other hydrogels. The in vitro mucoadhesion studies also showed that the mucoadhesive force of the hydrogel remained over 17,000 N/m2 during 4 h in the simulated oral cavity. The insulin loaded bilaminated film showed a pronounced hypoglycemic effect following buccal administration to healthy rats, achieving a 17% pharmacological availability compared with subcutaneous insulin injection. According to these results, the bilaminated film would be a promising delivery carrier for protein drugs via the buccal route. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
In vivo human electrochemical properties of a NiTi‐based alloy (Nitinol) used for minimally invasive implants
Authors: Pértile Luana B. , Silva Patrícia M. S. , Peccin Vinícius B. , Peres Ricardo , Silveira Pierre G. , Giacomelli Cristiano , Giacomelli Fernando C. , Fredel Márcio C. , Spinelli Almir
Published: May 2008

The development of a homemade device for in vivo human determination of the open circuit potential (OCP) of Nitinol is described. Pseudo‐reference electrodes (316L stainless steel and Pt) were initially tested and validated in vitro using simulated body fluids. As judged from the excellent electrochemical responses in terms of both accuracy and precision, the most ideal system comprised the combination of sterilized Pt (pseudo‐reference) and Nitinol (working) needle‐shaped electrodes. The average in vivo human OCP determined from independent measurements on six human patients with indication of direct arterial surgery was −0.334 ± 0.030 V/SCE. This value was in good agreement with data recorded in vitro using simulated body fluids (−0.313 ± 0.003 V/SCE in AFNOR S90‐701 artificial saliva; −0.334 ± 0.001 V/SCE in artificial urine; −0.239 ± 0.007 V/SCE in Ringer's solution). The thin surface film protecting the bulk NiTi alloy is therefore not susceptible to active dissolution at rest as long as the break down potentials (≫0.0 V/SCE) so far reported are well above OCP measured in this study. These results highlight the importance of evaluating the corrosion resistance of Nitinol under realistic conditions (mechanical loads, wear and fatigue) in order to establish multifaceted mechanisms that might lead to accelerated dissolution and failure of implanted stents. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Development of salmon collagen vascular graft: Mechanical and biological properties and preliminary implantation study
Authors: Nagai Nobuhiro , Nakayama Yasuhide , Zhou Yue‐Min , Takamizawa Keiichi , Mori Kazuo , Munekata Masanobu
Published: May 2008

Elastic salmon collagen (SC) vascular grafts were prepared by incubating a mixture of acidic SC solution and a fibrillogenesis‐inducing buffer containing a crosslinking agent [water‐soluble carbodiimide (WSC)] in a tubular mold at 4°C for 24 h and then at 60°C for 5 min. Subsequently, re‐crosslinking in ethanol solution containing WSC was performed. The dimension of the SC grafts was easily controlled by changing the size of the mold used. The compliance (stiffness parameter: β) and burst strength of the SC grafts (internal diameter, 2 mm; length, 20 mm; and wall thickness, 0.75 mm) that were prepared for implantation were 18.2 and 1434 mmHg, respectively; both these values were comparable with those of native vessels. Upon placement in rat subcutaneous pouches, the SC grafts were gradually biodegraded with little inflammatory reaction. The SC grafts were preliminarily implanted in rat abdominal aortas by using specially designed vascular connecting system. This system was used because the graft exhibited easy tearing and thus inadequate suturability. There was neither aneurysm formation nor graft rupture, but mild thrombus formation was seen within the 4‐week observation period. These grafts may be ideal for use in regenerative medicine because we believe that SC would be completely replaced with native vascular tissues after implantation, although further improvement in the mechanical properties of the graft is needed for anastomosis. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2008
QSAR model for alignment‐free prediction of human breast cancer biomarkers based on electrostatic potentials of protein pseudofolding HP‐lattice networks
Authors: Vilar Santiago , González‐Díaz Humberto , Santana Lourdes , Uriarte Eugenio
Published: May 2008

Network theory allows relationships to be established between numerical parameters that describe the molecular structure of genes and proteins and their biological properties. These models can be considered as quantitative structure–activity relationships (QSAR) for biopolymers. The work described here concerns the first QSAR model for 122 proteins that are associated with human breast cancer (HBC), as identified experimentally by Sjöblom et al. (Science 2006, 314, 268) from over 10,000 human proteins. In this study, the 122 proteins related to HBC (HBCp) and a control group of 200 proteins that are not related to HBC (non‐HBCp) were forced to fold in an HP lattice network. From these networks a series of electrostatic potential parameters (ξk) was calculated to describe each protein numerically. The use of ξk as an entry point to linear discriminant analysis led to a QSAR model to discriminate between HBCp and non‐HBCp, and this model could help to predict the involvement of a certain gene and/or protein in HBC. In addition, validation procedures were carried out on the model and these included an external prediction series and evaluation of an additional series of 1000 non‐HBCp. In all cases good levels of classification were obtained with values above 80%. This study represents the first example of a QSAR model for the computational chemistry inspired search of potential HBC protein biomarkers. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Structures, stabilities, electronic, and optical properties of C64 fullerene isomers, anions (C and C644−), metallofullerene Sc2@C64, and Sc2C2@C64
Authors: Cui Yan‐Hong , Tian Wei Quan , Feng Ji‐Kang , Chen De‐Li
Published: May 2008

The 3465 classical isomers of C64 fullerene have been investigated by quantum chemical methods PM3, and the most stable isomers have been refined with HCTH/3‐21G//SVWN/STO‐3G, B3LYP/6‐31G(d)//HCTH/3‐21G, and B3LYP/6‐311G(d)//B3LYP/6‐31G(d) level. C64(D2:0003) with the lowest e55 (e55 = 2), the number of pentagon‐pentagon fusions, is predicted to be the most stable isomer and it is followed by the C64(Cs:0077) and C64(C2:0103) isomers within relative energy of 20.0 kcal/mol. C64(D2:0003) prevails in a wide temperature range according to energy analysis with entropy contribution at B3LYP/6‐31G(d) level. The simulated IR spectra and electronic spectra help to identify different fullerene isomers. All the hexagons in the isomers with e55 = 2 display local aromaticity. The relative stabilities of C64 isomers change with charging in ionic states. Doping also affects the relative stabilities of fullerene isomers as demonstrated by Sc2@C64(D2:0003) and Sc2@C64(Cs:0077). The bonding of Sc atoms with C64 elongates the CC bond of two adjacent pentagons and enhances the local aromaticity of the fullerene cages. Charging, doping, and derativization can be utilized to isolate C64 isomers through differentiating the electronic and steric effects. © 2008 Wiley Periodicals, Inc. J Comput Chem 2008
Catecholaminergic responses to environmental stress in the hemolymph of zhikong scallop Chlamys farreri
Authors: Chen Muyan , Yang Hongsheng , Xu Biao , Wang Fangyu , Liu Baozhong
Published: May 2008

Catecholamines have long been known to play essential roles in several physiological processes in invertebrates. In this study, enzyme immunoassays were used to examine the levels of catecholamines (including adrenaline (AD), noradrenaline (NA) and dopamine (DA)) in the hemolymph of the scallop, Chlamys farreri, in responses to selected environmental stress. These stressors include high temperature (acute transfer from 17 to 28°C), low salinity (acute transfer from salinity 31 to 20 psu) and air exposure, which are commonly encountered in aquaculture practices or in their natural habitat. The results showed that both AD and NA concentrations increased significantly in response to all the stressors. The levels of these catecholamines peaked 72 hr after acute temperature or salinity stresses, and then decreased gradually. For scallops subjected to air exposure, the duration of AD concentration elevation depended on the exposure temperature with a higher air temperature resulting in a shorter time to return to control level. In contrast, the NA responses were long lasting and no obvious decreases were observed after reaching the peak value. Interestingly, the DA concentration showed an inverse trend in response to stresses compared with AD or NA. These results suggested that the catecholaminergic responses in bivalve hemolymph will provide useful references in predicting the success of aquaculture practices and monitoring the environmental stresses. J. Exp. Zool. 309A:289–296, 2008. © 2008 Wiley‐Liss, Inc.
Novel regimen through combination of memantine and tea polyphenol for neuroprotection against brain excitotoxicity
Authors: Chen Chang‐Mu , Lin Jen‐Kun , Liu Shing‐Hwa , Lin‐Shiau Shoei‐Yn
Published: May 2008

NMDA receptors are abundant, ubiquitously distributed throughout the brain, fundamental to excitatory neurotransmission, and critical for normal CNS function. However, excessive glutamate overstimulates NMDA receptors, leading to increased intracellular calcium and excitotoxicity. Mitochondrial dysfunction associated with loss of Ca2+homeostasis and enhanced cellular oxidative stress has long been recognized to play a major role in cell damage associated with excitotoxicity. In this experiment, we attempted to explore whether treatment with memantine (an NMDA receptor antagonist) and tea polyphenol (an antioxidant and anti‐inflammatory agent), either alone or in combination, is effective in neuroprotection in a mouse excitotoxic injury model. Memantine (10 mg/kg/day), tea polyphenol (60 mg/kg/day), or a combination (memantine 5 mg/kg/day plus tea polyphenol 30 mg/kg/day) was administered by oral gavage for 2 consecutive days before causing excitotoxic injury. Mice received a 0.3‐μL NMDA [335 mM (pH 7.2)] injection into the left striatum. Locomotor activity was assessed 24 hr before and after excitotoxic injury. Brain synaptosomes were harvested 24 hr after excitotoxic injury for assessment of Na+, K+‐ATPase and Mg2+‐ATPase activity, reactive oxygen species production, mitochondrial membrane potential (ΔΨm), mitochondrial reductase activity (MTT test), and Ca2+concentration. The results showed that treatment with memantine could significantly rescue mitochondrial function by attenuating the decreased mitochondrial membrane potential (ΔΨm) and mitochondrial reductase activity in mouse excitotoxic injury. Treatment with tea polyphenol could significantly decrease the increased production of synaptosomal reactive oxygen species (ROS) and thus reduced the deteriorative ROS‐sensitive Na+, K+‐ATPase and Mg2+‐ATPase activity. However, neither memantine nor tea polyphenol alone could significantly improve the impaired locomotor activity unless treatment was combined. Combined treatment with memantine and tea polyphenol could significantly protect mice against excitotoxic injury by reducing the increased synaptosomal ROS production, attenuating the decreased Na+, K+‐ATPase and Mg2+‐ATPase activity, the mitochondrial membrane potential (ΔΨm), the mitochondrial reductase activity, and the increased synaptosomal Ca2+concentration. In addition, the impairment in locomotor activity was also significantly improved. Therefore, the combined treatment of memantine and tea polyphenol is more effective in neuroprotection than either memantine or tea polyphenol alone in mouse excitotoxic injury. These findings provide useful information about the potential application of memantine and tea polyphenols in preventing clinical excitotoxic injury such as brain trauma, brain ischemia, epilepsy, and Alzheimer's disease. © 2008 Wiley‐Liss, Inc.
Up‐regulation of ciliary neurotrophic factor receptor expression by GABAA receptors in undifferentiated neural progenitors of fetal mouse brain
Authors: Fukui Masaki , Nakamichi Noritaka , Yoneyama Masanori , Yoshida Kohei , Ozawa Shusuke , Kitayama Tomoya , Nakamura Nobuhiro , Taniura Hideo , Yoneda Yukio
Published: May 2008

In this study, we evaluated the role of the GABAA receptor (GABAAR), expressed by undifferentiated neural progenitors isolated from fetal mouse neocortex, in the mechanisms relevant to self‐replication and differentiation toward neuronal and astroglial lineages. Round spheres were formed with clusters of proliferating cells within 2–4 days during culture with epidermal growth factor (EGF), whereas the size of these clusters was drastically increased in proportion to increasing durations up to 10 days. Sustained exposure to the GABAAR agonist muscimol at 100 μM led to significant increases in the size of neurospheres cultured for 6–10days, with increased proliferative activity and unchanged lactate dehydrogenase release in a manner sensitive to the GABAAR antagonist bicuculline. Muscimol also significantly increased the incorporation of 5‐bromo‐2′‐deoxyuridine in neurospheres in a bicuculline‐sensitive manner, whereas both high potassium and nifedipine significantly decreased the neurosphere area with increased numbers of apoptotic cells. Prior activation of GABAAR significantly promoted the subsequent expression of an astroglial marker protein in cells differentiated by ciliary neurotrophic factor (CNTF) toward an astroglial lineage after the removal of EGF, with a concomitant decrease in neuronal marker protein expression. In neurospheres with GABAAR activation, a significant and predominant increase was seen in mRNA expression of CNTF receptors. These results suggest that prior tonic activation of GABAAR may preferentially promote the differentiation by CNTF of neural progenitor cells toward an astroglial lineage through selective up‐regulation of CNTF receptor expression in the developing mouse brain. © 2008 Wiley‐Liss, Inc.
Protein phosphatase 2A–negative regulation of the protective signaling pathway of Ca2+/CaM‐dependent ERK activation in cerebral ischemia
Authors: Zhao Jie , Wu Hui‐wen , Chen Yun‐jiao , Tian He‐ping , Li Li‐xin , Han Xiao , Guo Jun
Published: May 2008

Extracellular‐signal‐regulated kinase (ERK) undergoes rapid inactivation following the intense activation evoked by cerebral ischemia and reperfusion. However, the precise mechanism of this inactivation has not been elucidated. To investigate how phosphatases regulate the ERK cascade following ischemia, the PP2A inhibitors cantharidin and okadaic acid were administrated to the CA1 subregion of the rat hippocampus. The resulting sustained ERK activity implies that PP2A is a major phosphatase contributing to the rapid inactivation, but not activation, of ERK following cerebral ischemia. The increase in PP2A activity induced by ceramide has a weak effect on the activation of Raf via dephosphorylation of Ser259 in response to ischemia. In contrast, ketamine (Keta) and cyclosporine A (CsA), two chemicals that block calcium signal in ischemia, decrease ERK activity by blocking Raf dephosphorylation of Ser259. We also observed that activation of an upstream protein, Ras‐GRF, leads to calcium/calmodulin‐dependent activation of the ERK signaling cascade in response to ischemic stimuli. In addition, the activity of cyclic AMP response element‐binding protein (CREB) and estrogen receptor α (ERα), target proteins of ERK and protective elements against ischemic lesion, parallels the activity of ERK. These data indicate that PP2A plays a significant role in blocking the protective effect induced by the ERK kinase pathway and that fast inactivation of ERK is the result of cross talk between calcium/calmodulin‐dependent, positively regulated signal cascades and a ceramide‐dependent negative signaling pathway. © 2008 Wiley‐Liss, Inc.
The growth‐inhibitory protein Nogo is involved in midline routing of axons in the mouse optic chiasm
Authors: Wang Jun , Chan Chung‐Kit , Taylor Jeremy S.H. , Chan Sun‐On
Published: May 2008

We have investigated the role of Nogo, a protein that inhibits regenerating axons in the adult central nervous system, on axon guidance in the developing optic chiasm of mouse embryos. Nogo protein is expressed by radial glia in the midline within the optic chiasm where uncrossed axons turn, and the Nogo receptor (NgR) is expressed on retinal neurites and growth cones. In vitro neurite outgrowth from both dorsonasal and ventrotemporal retina was inhibited by Nogo protein, and this inhibition was abolished by blocking NgR activity. In slice cultures of the optic pathway, blocking NgR with a peptide antagonist produced significant reduction in the uncrossed projection but had no effect on the crossing axons. This result was confirmed by treating cultures with an anti‐Nogo functional blocking antibody. In vitro coculture assays of retina and optic chiasm showed that NgR was selectively reduced on neurites and growth cones from dorsonasal retina when they contacted chiasm cells, but not on those from ventrotemporal retina. These findings provide evidence that Nogo signaling is involved in directing the growth of axons in the mouse optic chiasm and that this process relies on a differential regulation of NgR on axons from the dorsonasal and ventrotemporal retina. © 2008 Wiley‐Liss, Inc.
Virus‐induced alterations of membrane lipids affect the incorporation of PrPSc into cells
Authors: Avrahami Dana , Dayan‐Amouyal Yael , Tal Saar , Mincberg Michal , Davis Claytus , Abramsky Oded , Gabizon Ruth
Published: May 2008

Prion diseases are fatal neurodegenerative disorders characterized by long incubation periods. To investigate whether concurrent diseases can modify the clinical outcome of prion‐affected subjects, we tested the effect of viral infection on the binding and internalization of PrPSc, essential steps of prion propagation. To this effect, we added scrapie brain homogenate or purified PrPSc to fibroblasts previously infected with minute virus of mice (MVM), a mouse parvovirus. We show here that the rate of incorporation of PrPSc into MVM‐infected cells was significantly higher than that observed for naïve cells. Immunostaining of cells and immunoblotting of subcellular fractions using antibodies recognizing PrP and LysoTracker, a lysosomal marker, revealed that in both control and MVM‐infected cells the incorporated PrPSc was associated mostly with lysosomes. Interestingly, floatation gradient analysis revealed that the majority of the PrPSc internalized into MVM‐infected cells shifted toward raft‐containing low‐density fractions. Concomitantly, the MVM‐infected cells demonstrated increased levels of the glycosphingolipid GM1 (an essential raft lipid component) throughout the gradient and a shift in caveolin 1 (a raft protein marker) toward lighter membrane fractions compared with noninfected cells. Our results suggest that the effect of viral infection on membrane lipid composition may promote the incorporation of exogenous PrPSc into rafts. Importantly, membrane rafts are believed to be the conversion site of PrPC to PrPSc; therefore, the association of exogenous PrPSc with such membrane microdomains may facilitate prion infection. © 2008 Wiley‐Liss, Inc.
The way to a high‐performance culture with the Total Performance Scorecard
Authors: Rampersad Hubert K.
Published: May 2008

A new blueprint for creating a highly engaged and happy workforce is needed, where personal and organizational performance and learning mutually reinforce each other on a sustainable basis. This paper introduces a new business management concept, called Total Performance Scorecard (TPS), defined as the systematic process of continuous, gradual, and routine improvement, development, and learning, focused on a sustainable increase of personal, organizational, and project performances. It stresses the importance and need to develop a high‐performance culture that combines the goals and aspirations of the individual with those of the company.

These concepts provide solutions to preserve and utilize individual rights and capabilities while adjusting the organizational culture and philosophy to this new environment. This has been done by expanding and integrating concepts such as the Personal Balanced Scorecard, Organizational Balanced Scorecard, Project Balanced Scorecard, Lean Six Sigma, and Talent Management into one overall holistic and organic framework.

This model will help organizations manage the demanding and often frustrating road toward sustained employee engagement and improvement.

Copyright © 2008 John Wiley & Sons, Ltd.
Comparison of mineral and trace element contents in onion cultivars (Allium cepa L.)
Authors: Galdón Beatriz Rodríguez , González Rafael Oropeza , Rodríguez Elena Rodríguez , Romero Carlos Díaz
Published: May 2008

BACKGROUND: P, Na, K, Ca, Mg, Fe, Cu, Zn, Mn and Se were determined in five traditional onion cultivars (Allium cepa L.) from Tenerife (Guayonje, San Juan de la Rambla, Carrizal Alto, Carrizal Bajo and Masca) and a commercial cultivar (Texas Early Grano 502) grown under the same agronomic, soil and climatic conditions in order to find out differences between these cultivars.

RESULTS: Carrizal Alto presented the highest K content and lowest P, Na, Fe, Zn, Mn and Se. Texas cultivar had the highest P, Mg and Se contents, and the lowest contents of Ca, Cu and Mn. There were clear differences in the mineral and trace elements contents between the two seed origins of San Juan de la Rambla cultivar. Many correlations were found between the parameters analyzed, emphasizing the FeZn and CaMn correlations.

CONCLUSION: There were differences in the mineral and trace element composition between the onion cultivars. The environment and agronomic practices could affect the genetic information of the seeds, determining changes in the mineral and trace element composition. Linear discriminant analysis is a useful tool for differentiating onion samples according to cultivar and seed origin. Copyright © 2008 Society of Chemical Industry
Parabolic finite volume element equations in nonconvex polygonal domains
Authors: Chatzipantelidis P. , Lazarov R.D. , Thomée V.
Published: May 2008

We study spatially semidiscrete and fully discrete finite volume element approximations of the heat equation with homogeneous Dirichlet boundary conditions in a plane polygonal domain with one reentrant corner. We show that, as a result of the singularity in the solution near the reentrant corner, the convergence rate is reduced from optimal second order, similarly to what was shown for the finite element method in the earlier work 2. Optimal order convergence may be restored by mesh refinement near the corners of the domain. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009
Unified multipliers‐free theory of dual‐primal domain decomposition methods
Authors: Herrera Ismael , Yates Robert A.
Published: May 2008

The concept of dual‐primal methods can be formulated in a manner that incorporates, as a subclass, the non preconditioned case. Using such a generalized concept, in this article without recourse to “Lagrange multipliers,” we introduce an all‐inclusive unified theory of nonoverlapping domain decomposition methods (DDMs). One‐level methods, such as Schur‐complement and one‐level FETI, as well as two‐level methods, such as Neumann‐Neumann and preconditioned FETI, are incorporated in a unified manner. Different choices of the dual subspaces yield the different dual‐primal preconditioners reported in the literature. In this unified theory, the procedures are carried out directly on the matrices, independently of the differential equations that originated them. This feature reduces considerably the code‐development effort required for their implementation and permit, for example, transforming 2D codes into 3D codes easily. Another source of this simplification is the introduction of two projection‐matrices, generalizations of the average and jump of a function, which possess superior computational properties. In particular, on the basis of numerical results reported there, we claim that our jump matrix is the optimal choice of the B operator of the FETI methods. A new formula for the Steklov‐Poincaré operator, at the discrete level, is also introduced. © 2008 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2009