bluuebunny/crossref_metadata_2025 huggingface dataset:
Small Molecule Inhibitors Targeting HIV‐1 Reverse Transcriptase Dimerization
Authors: Grohmann Dina , Corradi Valentina , Elbasyouny Mira , Baude Annika , Horenkamp Florian , Laufer Sandra D. , Manetti Fabrizio , Botta Maurizio , Restle Tobias
Published: March 2008

The enzymatic activities of human immunodeficiency virus type 1 (HIV‐1) reverse transcriptase (RT) are strictly correlated with the dimeric forms of this vital retroviral enzyme. Accordingly, the development of inhibitors targeting the dimerization of RT represents a promising alternative antiviral strategy. Based on mutational studies, we applied a structure‐based ligand design approach generating pharmacophoric models of the large subunit connection subdomain to possibly identify small molecules from the ASINEX database, which might interfere with the RT subunit interaction. Docking studies of the selected compounds identified several candidates, which were initially tested in an in vitro subunit association assay. One of these molecules (MAS0) strongly reduced the association of the two RT subunits p51 and p66. Most notably, the compound simultaneously inhibited both the polymerase as well as the RNase H activity of the retroviral enzyme, following preincubation with t1/2 of about 2 h, indicative of a slow isomerization step. This step most probably represents a shift of the RT dimer equilibrium from an active to an inactive conformation. Taken together, to the best of our knowledge, this study represents the first successful rational screen for a small molecule HIV RT dimerization inhibitor, which may serve as attractive hit compound for the development of novel therapeutic agents.
1,2‐Alkyl Migration as a Key Element in the Invention of Cascade Reactions Catalyzed by π‐Acids
Authors: Crone Benedikt , Kirsch Stefan F.
Published: March 2008

This brief overview highlights recent progress in the field of cascade reactions that are initiated by the activation of a π‐system using platinum and gold catalysts and that are coupled with a 1,2‐alkyl migration step. While the reactions discussed aim to rapidly evolve molecular complexity, they are experimentally straightforward and easy to perform. Primarily guided by the type of 1,2‐alkyl migration, methods are categorized as shifts to metal carbenoid centers and pinacol‐type rearrangements.
Adsorption d'un colorant textile réactif sur un biosorbant non‐conventionnel : Les fibres de Posidonia oceanica (L.) delile
Authors: Mahjoub Borhane , Ncibi Mohamed Chaker , Seffen Mongi
Published: March 2008

Les fibres du végétal marin Posidonia oceanica (L.) ont été utilisées en tant que matrice adsorbante d'un colorant textile réactif (Cibacron Red) pour son élimination des solutions aqueuses. Des essais en batch ont été réalisés pour déterminer les cinétiques et les isothermes d'adsorption. Les variables expérimentales étudiées sont la taille des particules, la quantité de fibres, la température, le pH et les prétraitements chimiques. L'état d'équilibre est atteint au bout de 48 h. La capacité de biosorption semble être maximisée par une augmentation de la quantité de support. La température a également un effet stimulant sur la biosorption du colorant. Le maximum de biosorption a été observé à un pH de 5,5. Le prétraitement préalable des fibres à l'acide phosphorique et nitrique permet d'augmenter considérablement leur capacité d'adsorption. La modélisation des données expérimentales a montré que les modèles du pseudo‐second ordre et de Freundlich décrivent, respectivement, les cinétiques et les isothermes d'adsorption d'une façon satisfaisante. L'étude des aspects thermodynamiques a montré que l'adsorption du colorant par la biomasse P. oceanica est un phénomène favorable, endothermique et spontané.
Theoretical modelling of the electrode thickness effect on maximum power point of dye‐sensitized solar cell
Authors: Ni Meng , Leung Michael K. H. , Leung Dennis Y. C.
Published: March 2008

The maximum power point (MPP) of a dye‐sensitized solar cell (DSSC) is often more important than the open‐circuit voltage and the short‐circuit current as MPP better represents the DSSC power output and energy conversion efficiency. In this investigation, the DSSC J–V characteristics and MPP were studied using a simple theoretical electron diffusion model. Parametric analyses were performed to determine the particular effect of electrode thickness on the MPP output. The analytical results are well consistent with the experimental results published in the literature. In the optimization analysis, it was specially found that the optimal electrode thickness for the highest MPP is rather insensitive to the operating conditions. It implies that an optimally designed DSSC can be always operated at its highest MPP regardless of any geographical, seasonal, and solar hour factors. Such an important attribute facilitates the design and manufacture of DSSC for worldwide commercialization at competitive costs.
Ru2M(dpa)4Cl2 (M = Cu, Ni): Synthesis, Characterization, and Theoretical Analysis of Asymmetric Heterometal String Complexes of the Dipyridylamide Family
Authors: Huang Gin‐Chen , Bénard Marc , Rohmer Marie‐Madeleine , Li Long‐An , Chiu Mei‐Jyun , Yeh Chen‐Yu , Lee Gene‐Hsiang , Peng Shie‐Ming
Published: March 2008

Four heterotrinuclear strings of metal atoms stabilized by dipyridylamide (dpa–) ligands were synthesized and characterized. The metal frameworks of Ru2Cu(dpa)4Cl2 (1), its monooxidized counterpart [Ru2Cu(dpa)4Cl2]PF6 (2), and their nickel homologues, Ru2Ni(dpa)4Cl2 (3) and [Ru2Ni(dpa)4Cl2]PF6 (4), were shown by X‐ray diffraction to be nonsymmetric, in spite of a severe disorder affecting the metal positions. The metal string is composed of a Ru dimer with a short Ru–Ru bond that is completed with the heterometal at a longer distance from the central ruthenium atom. This nonsymmetric structure was confirmed from NMR spectroscopy. The [Ru2M]6+ framework of 1 and 3 was shown from spectroelectrochemical analysis and DFT calculations to exist in the form of a mixed‐valent [Ru2]5+ moiety coupled to a formally M+ heterometal. The temperature‐dependant magnetic susceptibility of these compounds is reported and interpreted by means of a model previously applied to [Ru2]5+ complexes. The redox chemistry of 1 and 3 was investigated by cyclic voltammetry, and the electronic structure of the mono‐ and dioxidized species was assigned from the observed changes in the UV/Vis spectra and from DFT calculations.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Preparation and Crystal Structures of ­Purine 2,2′‐, 6,6′‐, and 8,8′‐Dimers
Authors: Tobrman Tomáš , Štěpnička Petr , Císařová Ivana , Dvořák Dalimil
Published: March 2008

Treatment of 9‐ or 7‐substituted 6‐, 2‐, or 8‐iodopurine derivatives with copper(I) thiophene‐2‐carboxylate or copper(I) 3‐methylsalicylate in N,N‐dimethylformamide affords the corresponding 6,6′‐, 2,2′‐, and 8,8′‐purine dimers in high yield. Cross‐dimerization reactions of different iodo derivatives were attempted, but only mixtures containing the cross‐coupled products, homodimers, or dehalogenation products were obtained. The crystal structures of 9,9′‐dibenzyl‐ (1a) and 9,9′‐bis(1‐methylethyl)‐9H,9′H‐[6,6′]bipurinyl (1c) and the salt [1aH2]Br2 were determined by single‐crystal X‐ray diffraction analysis, which revealed extensive hydrogen bonding and π···π stacking interactions. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Thermal properties and fire behaviour of materials produced from curing mixed epoxy and phenolic resins
Authors: Laza J. M. , Bilbao E. , Garay M. T. , Vilas J. L. , Rodríguez M. , León L. M.
Published: March 2008

Thermal stability and fire behaviour of materials obtained from curing mixed epoxy and phenolic resins have been studied, the decomposition processes being compared with those for the pure resins. Samples were cured by triethylenetetramine or p‐toluenesulphonic acid by isothermal pressing at 90∘C, and decompositions were carried out under nitrogen and air environment from 50 to 1000∘C. Only for mixtures with higher proportion of epoxy resin, the decomposition process goes through a unique step as for the pure resin. Results from fire tests indicated that mixtures are classified as M3 and F1. Copyright © 2008 John Wiley & Sons, Ltd.
Pricing and hedging illiquid energy derivatives: An application to the JCC index
Authors: Scarpa Elisa , Manera Matteo
Published: March 2008

In this paper a simple strategy for pricing and hedging a swap on the Japanese crude oil cocktail (JCC) index is discussed. The empirical performance of different econometric models is compared in terms of their computed optimal hedge ratios, using monthly data on the JCC over the period January 2000–January 2006. An explanation to how to compute a bid/ask spread and to construct the hedging position for the JCC swap contract with variable oil volume is provided. The swap pricing scheme with backtesting and rolling regression techniques is evaluated. The empirical findings show that the price‐level regression model permits one to compute more precise optimal hedge ratios relative to its competing alternatives. © 2008 Wiley Periodicals, Inc. Jrl Fut Mark 28:464–487, 2008
Amplification of 11q13 in ovarian carcinoma
Authors: Brown Lindsay A. , Kalloger Steve E. , Miller Melinda A. , Shih Ie‐Ming , McKinney Steven E. , Santos Jennifer L. , Swenerton Ken , Spellman Paul T. , Gray Joe , Gilks C. Blake , Huntsman David G.
Published: March 2008

Amplification at the 11q13 locus is commonly observed in breast, ovarian, head and neck, oral, and esophageal cancer. Studies of this region led to the identification of multiple amplicons containing several potential oncogenes including EMSY, PAK1, RSF1, and GAB2. Here, we investigate the amplification of the above four genes and their prognostic significance in histologically and clinically defined subsets of ovarian cancer. Amplification of all four genes was assessed by fluorescent in situ hybridization in tissue microarrays containing 538 clinically annotated ovarian carcinomas with 12 years of follow‐up data. Overall, for the entire cohort, EMSY was amplified in 44 (16%) of 269 cases, PAK1 was amplified in 38 (15%) of 255 cases, RSF1 was amplified in 37 (12%) of 310 cases, and GAB2 was amplified in 41 (16%) of 255 cases. Amplification of EMSY, PAK1, RSF1, and GAB2 were all highly correlated with each other and with a serous histology. Univariate survival analysis showed that tumors with EMSY and RSF1 amplification were associated with a significantly worse outcome. A molecular inversion probe array was then used to study the 11q13 amplicon in 33 high grade serous carcinomas. The core of the amplicon mapped to a 6‐Mb region encompassing EMSY, PAK1, RSF1, and GAB2. However, a second more telomeric amplicon was also observed for which no candidate genes have been identified. In summary, amplification of these four putative oncogenes from 11q13 in early ovarian cancer is associated with a serous histology and in the case of EMSY and RSF1 a poor outcome. These findings support the hypothesis that the11q13 amplicon in ovarian cancer is likely driven by a cassette of genes rather than by a single oncogene. This article contains Supplementary Material available at http://www.interscience.wiley.com/jpages/1045‐2257/suppmat. © 2008 Wiley‐Liss, Inc.
Erratum: Effectiveness of health management departments of universities that train health managers in Turkey (p 263–288)
Authors: Karagoz Sevgul , Balci Ali
Published: March 2008

Int J Health Plann Mgmt 2007; 22: 263‐‐288.

DOI: 10.1002/hpm.854

The Editor‐In‐Chief would like to apologise for the quality of this paper as published in the present form in The International Journal of Health Planning and Management. A corrected version should have been submitted; the earlier version unfortunately was submitted for publication.

Reproduced below is the corrected Summary.

SUMMARY

This research has aimed to examine the effectiveness of the health management departments of universities which train health managers in Turkey. The study compares ‐ for lecturers and students ‐ nine variables of organisational effectiveness. These nine dimensions are derived from Cameron (1978; 1981; 1986). Factor analysis was used to validate the scale developed by the researcher. For internal consistency and reliability, the Cronbach Alpha reliability coefficient and item total correlation were applied. A questionnaire was administered to a total of 207 people in health management departments in Turkey. In analysis of the data, descriptive statistics and the t‐test were used. According to our research findings, at individual university level, lecturers found their departments more effective than did their students. The highest effectiveness was perceived at Baskent University, a private university. The best outcome was achieved for ‘organisational health’, and ‘the ability to acquire resources’ achieved the lowest outcome. Effectiveness overall was found to be moderate. Copyright © 2006 John Wiley & Sons, Ltd.

Apologies to the authors and readers for any inconvenience caused.
Comparison of PEI‐PEG and PLL‐PEG copolymer coatings on the prevention of protein fouling
Authors: Bergstrand Anna , Rahmani‐Monfared Ghazal , Östlund Åsa , Nydén Magnus , Holmberg Krister
Published: March 2008

The effect of surface charge on the protein resistance of adsorbed layers of poly(ethylene imine)‐[g]‐poly(ethylene glycol), PEI‐PEG, and poly(L‐lysine)‐[g]‐poly(ethylene glycol), PLL‐PEG, was studied. Mixed and monofunctional self‐assembled monolayers, SAMs, on gold were obtained by adsorption of 16‐mercapto‐1‐hexadecanoic acid and 16‐mercapto‐1‐hexadecanol. The surface charge was systematically varied by changing the ratio of the two alkanethiols. The graft copolymers PEI‐PEG and PLL‐PEG were adsorbed at the SAMs and tested for resistance towards human serum albumin and fibrinogen. The adsorbed amount of copolymers increased with increasing negative surface charge. However, the best protein resistance was found at an intermediate surface charge. The PLL‐PEG covered surfaces showed better protein resistance than the PEI‐PEG covered surfaces. Thus, this work demonstrates that an adsorbed layer of PEG‐grafted PEI and, in particular, PEG‐grafted PLL is efficient in preventing protein adsorption when there is charge neutralization between the copolymer and the underlying surface. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Multilayer composite scaffolds with mechanical properties similar to small intestinal submucosa
Authors: Lawrence Benjamin J. , Maase Eric L. , Lin Hsueh‐Kung , Madihally Sundararajan V.
Published: March 2008

Use of biodegradable scaffolds to engineer new tissues has become an attractive option in various transplantation protocols. In particular, small intestinal submucosa (SIS) has generated immense interest in various tissue engineering applications because of its diverse favorable properties. However, it is a natural matrix, which leads to problems in large‐scale preparations and contains sample to sample heterogeneity. In this study, we explored the formation of synthetic matrix mimicking the characteristics of the SIS. Three‐dimensional composite structures were developed by sandwiching 50:50 PLGA film between porous chitosan matrices. The outer chitosan layers provide biological activity while the inner PLGA layer provides mechanical strength. PLGA films were initially perforated at 1 cm distance, and the porous chitosan matrix was formed sequentially on each side by controlled rate freezing and lyophilization technique at −80°C. Scanning electron microscopy analysis showed a layered microarchitecture with chitosan filling the perforations of PLGA membrane. Urea permeability studies confirmed that the perforations were filled (negligible urea transfer across composite over 8 h). Tensile strength analysis showed that the matrices formed using 160 kDa PLGA had sufficient break stress (∼4.5 MPa). Degradation analysis over 8 weeks in the presence of 10 mg/L lysozyme showed a 50% decrease in total weight and an 80% decrease in PLGA molecular weight. When cellular adhesion and actin distribution of mouse embryonic fibroblasts were evaluated, for 7 days, cells showed their typical spindle shape and redistribution of actin fibers on composite matrices. Viability studies and MMP‐2/MMP‐9 activity showed that the cells were viable and functional, similar to tissue culture plastic. Further, canine bladder smooth muscle cells also showed similar cell adhesion and spreading on the composite matrix. In summary, composite structures mimicking SIS were constructed and show potential as a tissue engineering material. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Dislocation identification and in situ straining in the spinodal Fe30Ni20Mn25Al25 alloy
Authors: Loudis J.A. , Baker I.
Published: March 2008

Dislocations in the spinodal alloy Fe30Ni20Mn25Al25, which is composed of alternating BCC and B2 (ordered BCC) phases, have been investigated using weak‐beam transmission electron microscopy (TEM). The alloy was compressed at room temperature in an as‐hot‐extruded state to strains of ∼3% for post‐mortem dislocation analysis. Dislocations with a/2〈111〉 Burgers vectors were found to glide in pairs on both {110} and {112} slip planes. TEM in situ straining experiments were also performed on both the as‐extruded alloy and an arc‐melted alloy. The in situ straining observations confirmed that dislocations were able to pass between both spinodal phases. Partial dislocation separations were relatively wide in the BCC phase and narrow in the B2 phase. Dislocation glide, as opposed to twinning (both of which have been observed in other BCC‐based spinodals), was also found to be the only room temperature deformation mechanism. Microsc. Res. Tech., 2008. © 2008 Wiley‐Liss, Inc.
First‐trimester maternal serum progesterone in aneuploid pregnancies
Authors: Christiansen Michael , Sørensen Tina Lindvig , Larsen Severin Olesen , Nørgaard‐Pedersen Bent
Published: March 2008

Background

First‐trimester maternal serum screening for Down syndrome (DS) can be improved by the use of additional serum markers. We examined whether progesterone (P), synthesized by placenta, might be a first‐trimester maternal serum marker for fetal DS.

Materials and Methods

P was quantified in first‐trimester maternal serum from 42 DS, six trisomy 18 and two trisomy 13 pregnancies and 115 controls. Log‐regression of P versus gestational age in days was used to convert P concentrations into multiples of the median (MoM).

Results

The P concentrations in controls increased with gestational age (p = 9.5 × 10−7). The log10MoM P distribution in DS pregnancies was not significantly different from that in controls. However, from day 58–67, the log10MoM P was elevated in DS pregnancies (n = 10) with a mean (SD) of 0.1040 (0.0956), compared to a mean (SD) of − 0.0109 (0.1661) in controls (n = 24) (p = 0.05). Five out of six trisomy 18 and both trisomy 13 pregnancies had a P MoM < 1.

Conclusion

P is not a useful marker for DS in first trimester, except perhaps in a narrow gestational age window from day 58 to 67. P is a trisomy 18/13 marker. Copyright © 2008 John Wiley & Sons, Ltd.
First trimester screening for Down syndrome in rhesus negative women
Authors: Muhcu Murat , Mungen Ercument , Atay Vedat , Ipcioglu Osman Metin , Dundar Ozgur , Ergur Rustu , Yergok Yusuf Ziya
Published: March 2008

Objectives

To explore the effect of maternal rhesus status on first‐trimester screening markers for Down syndrome.

Methods

We accessed a database of singleton pregnancies undergoing first‐trimester genetic screen with maternal Rh status documented and pregnancy outcome information available. Excluded were cases of fetal chromosomal or structural abnormalities, or maternal systemic disease. Results of maternal serum pregnancy‐associated plasma protein A (PAPP‐A) and β‐human chorionic gonadotrophin (β‐hCG) adjusted for gestational age were compared between Rh‐negative and Rh‐positive women with p < 0.05 considered significant.

Results

Two thousand two hundred and two pregnancies fulfilled the study criteria, and 160 of them (7%) were Rh negative. Only free β‐hCG corrected multiples of the median (MoM) values were statistically increased in Rh‐negative women (p < 0.009). Using a cut‐off of 1:300, screen‐positive rates of maternal serum biochemistry were not significantly different between Rh‐negative and Rh‐positive women (12.5 vs 10.4%, p = 0.41).

Conclusion

The present study focused on measurements of β‐hCG and PAPP‐A in the sera of women with Rh‐negative blood group. Women with Rh‐negative blood type have similar first‐trimester serum PAPP‐A MoM values as Rh‐positive women, but significantly higher β‐hCG MoM values. However, there was no significant difference in the screen‐positive rate for Down syndrome between the two groups. Copyright © 2008 John Wiley & Sons, Ltd.
Proteome analysis of aflatoxin B1‐induced hepatocarcinogenesis in tree shrew (Tupaia belangeri chinensis) and functional identification of candidate protein peroxiredoxin II
Authors: Li Yuan , Qin Xue , Cui Jiefeng , Dai Zhi , Kang Xiaonan , Yue Haiying , Zhang Yu , Su Jianjia , Cao Ji , Ou Chao , Yang Chun , Duan Xiaoxian , Yue Huifen , Liu Yinkun
Published: March 2008

In order to explore the proteins responsible for hepatocellular carcinoma (HCC), aflatoxin B1‐induced hepatocarcinogenesis in tree shrew (Tupaia belangeri chinensis) was analyzed with 2‐DE and MS. By comparing HCC samples with their own precancerous biopsies and HCC‐surrounding tissues, a group of candidate proteins that differentially expressed in HCC were obtained. Peroxiredoxin (Prx) II, one of the candidates with distinct alteration, was further investigated and validated. Western blot and RT‐PCR assays confirmed the overexpression of Prx II in both tree shrew and human HCC tissues. RNA interference for silencing Prx II was employed subsequently to explore the function and underlying mechanism of Prx II on liver cancer cell line Hep3B. Results showed the cell proliferation and clone formation decreased obviously when Prx II expression was inhibited, while the flow cytometer analysis showed the percentage of cell apoptosis enhanced. Inhibition of Prx II expression also obviously increased the generation of ROS and malondialdehyde, both are the products from peroxidation. These results imply the important role of Prx II in hepatocarcinogenesis, possibly through its function in regulating peroxidation and hereby to provide a favorable microenvironment for cancer cell surviving and progressing.
6th HUPO Annual World Congress – Proteomics Standards Initiative Workshop 6–10 October 2007, Seoul, Korea
Authors: Orchard Sandra , Martens Lennart , Tasman Joshua , Binz Pierre‐Alain , Albar Juan Pablo , Hermjakob Henning
Published: March 2008

The plenary session of the Proteomics Standards Initiative of the Human Proteome Organisation at the 6th annual HUPO world congress updated the delegates on the current status of the ongoing work of this group. The new MS interchange format, mzML, had been entered into the HUPO document process immediately prior to the meeting and was already under active discussion by prospective users. It is anticipated this will become the de facto standard in this area in 2008. Minimal requirements documents are in the process of being published and proteomics journals are beginning to request data deposition as part of the manuscript submission process. The session ended with a lively debate on the practical implications these advances will have on daily laboratory work, on submission procedures and the tools which are being developed to assist in these activities.
Proteomics Data Collection – 2nd ProDaC Workshop 5 October 2007, Seoul, Korea
Authors: Eisenacher Martin , Hardt Tanja , Hamacher Michael , Martens Lennart , Häkkinen Jari , Levander Fredrik , Apweiler Rolf , Meyer Helmut E. , Stephan Christian
Published: March 2008

Proteomics Data Collection (ProDaC) is an EU‐funded “Coordination Action” within the 6th framework programme. It aims to simplify the publication, dissemination and utilization of proteomics data by establishing standards that will support broad data collection from the research community. As a part of ProDaC, regular workshops are organized on a half‐yearly basis to enable communication and discussion of the involved partners and to report on project progress. After the kick‐off meeting (October 2006) in Long Beach, CA, USA and the 1st workshop in Lyon, France (April 2007), the 2nd ProDaC workshop took place at the COEX InterContinental Hotel in Seoul, Korea, on 5th October 2007, shortly before the HUPO World Congress. The progress achieved within the first year was presented by the leaders of the work packages. Additionally, a Journal's representative talked about his experiences and future plans concerning Proteomics standards; and two further external speakers presented their research related to data handling and Proteomics repositories.
Disease proteomics of endocrine disorders revealed by two‐dimensional gel electrophoresis and mass spectrometry
Authors: Oh‐Ishi Masamichi , Kodera Yoshio , Furudate Sen‐ichi , Maeda Tadakazu
Published: March 2008

Endocrine disorders such as dwarfism and diabetes show abnormalities in many different organs even if a certain hormone is the primary cause of the disease. One of the aims of proteomics is to elucidate an abnormal hormone network underlying dysfunction in the disease through quantitative and qualitative proteome analyses of various organs. In a comprehensive study of the rdw rat with hereditary dwarfism, we found the accumulation of ER proteins in the rdw thyroid. Contrary to the initial notion that the dwarfism of the rat was caused by genetic mutations related to pituitary hormones, the primary cause is a missense mutation in the thyroglobulin gene. To understand at the protein level cellular damage caused by oxidative stress, we developed a proteomic method and applied to detecting protein carbonyls in various organs of a diabetes model OLETF rat. The method would provide a means toward clarifying a comprehensive view of oxidative modifications of proteins in diabetes. We review 2‐DE‐based disease proteomics of endocrine disorders in general, with particular attention paid to our proteome projects by a 2‐DE method with an agarose IEF gel in the first dimension (agarose 2‐DE) and LC‐MS/MS.
Clinical proteomics of the cerebrospinal fluid: Towards the discovery of new biomarkers
Authors: Roche Stéphane , Gabelle Audrey , Lehmann Sylvain
Published: March 2008

The cerebrospinal fluid (CSF) circulates within the CNS where it plays an essential physiological role in homeostasis of neuronal cells. This biological fluid has an important protein diversity that results from both filtration of serum through the blood–brain barrier and production/secretion of neuronal peptides and proteins. Changes in CSF composition depend on blood proteome, CSF circulation alterations, as well as physiological or pathological brain status. Hence, CSF proteomic analysis gives a unique opportunity to detect and describe biomarkers in neurological affections. Although lumbar puncture is considered as invasive, post lumbar puncture events remain rare and minor. Nevertheless, CSF biological analysis is currently limited to a small number of parameters and clinical situations suggesting mainly meningitis, malignancies or dementia. Few CSF proteomic studies have been performed in comparison to those on blood. In this review, we will provide a proteomics description of the CSF, summarize the current clinical use of this fluid and describe its clinical proteomics examination.
Grafting of Poly(methyl methacrylate) Brushes from Magnetite Nanoparticles Using a Phosphonic Acid Based Initiator by Ambient Temperature Atom Transfer Radical Polymerization (ATATRP)
Authors: Babu Kothandapani , Dhamodharan Raghavachari
Published: March 2008

Poly(methyl methacrylate) in the brush form is grown from the surface of magnetite nanoparticles by ambient temperature atom transfer radical polymerization (ATATRP) using a phosphonic acid based initiator. The surface initiator was prepared by the reaction of ethylene glycol with 2-bromoisobutyrl bromide, followed by the reaction with phosphorus oxychloride and hydrolysis. This initiator is anchored to magnetite nanoparticles via physisorption. The ATATRP of methyl methacrylate was carried out in the presence of CuBr/PMDETA complex, without a sacrificial initiator, and the grafting density is found to be as high as 0.90 molecules/nm2. The organic–inorganic hybrid material thus prepared shows exceptional stability in organic solvents unlike unfunctionalized magnetite nanoparticles which tend to flocculate. The polymer brushes of various number average molecular weights were prepared and the molecular weight was determined using size exclusion chromatography, after degrafting the polymer from the magnetite core. Thermogravimetric analysis, X-ray photoelectron spectra and diffused reflection FT-IR were used to confirm the grafting reaction.
Congenital dislocation of the patella
Authors: Wada Akifusa , Fujii Toshio , Takamura Kazuyuki , Yanagida Haruhisa , Surijamorn Panya
Published: March 2008

Purpose

Congenital dislocation of the patella is permanent and manually irreducible, and it manifests immediately after birth with flexion contracture of the knee, genu valgus, external tibial torsion and foot deformity. We retrospectively reviewed the results of operative treatment of seven knees in six patients with congenital dislocation of the patella.

Methods

The age of the six patients at diagnosis ranged from 8 days to 3.6 years, with an average of 1.3 years, and their age at the time of operation ranged from 0.6 to 3.9 years, with an average of 2.1 years. Serial casting and/or a brace was attempted before surgery in five of seven knees, leading to improvement in the flexion contracture of the knee. All knees were treated operatively in combination with lateral release, medial plication, V-Y lengthening of the quadriceps, medial transfer of the lateral patellar tendon and posterior release of the knee.

Results

Although these deformities were noticed at birth in all seven knees, diagnosis was delayed in three knees due to the low suspicion of the disease and invisible patellae on radiographs. Ultrasonography confirmed the diagnosis of dislocation. The patella was centered in the groove of the femoral condyle after surgery in all knees, but subluxation of the knee with flexion was observed in one knee in which the operation was performed at 3.9 years. Genu valgus and external tibial torsion improved after surgery in all knees. The operated knee was mobile in all cases, with less than 10° flexion contracture of the knee. Flexion contracture did not increase in any of the knees.

Conclusion

Congenital dislocation of the patella should be suspected in every patient with knee flexion contracture, genu valgus, external tibial torsion, foot deformity and delayed walking. Successful results were obtained when the operation was performed in younger children. Other procedures, such as the semitendinosus tenodesis or tendon transfer, might have to be combined to achieve better stability with flexion in older children.
Dissipative structures in fault zones and their diagnostic criteria (from physical modeling data)
Authors: Bornyakov S.A. , Truskov V.A. , Cheremnykh A.V.
Published: March 2008

A fault zone is considered an open nonequilibrium dynamic system in which its constituent subsystems evolve by self-organization in a nonlinear synergetic process of successive changes of structural levels (stages). A new term fault dissipative structure is suggested for an ordered 3D space-time structure produced in a fault zone by self-organization of fracturess of different scales. The approach is used in physical modeling to simulate the evolution of a strike-slip fault zone in an elastic-viscoplastic lithosphere and to recognize space and time criteria diagnostic of fault dissipative structures through fractal and entropy analyses.
An endoscopic grading system for vocal process granuloma
Authors: Farwell D G , Belafsky P C , Rees C J
Published: March 2008

Background:

A reliable grading system allows the clinician to classify disease severity, monitor progress and evaluate treatment efficacy. There is no currently accepted grading system for vocal process granuloma of the larynx.

Aim:

To evaluate the reliability of a new grading system for vocal process granuloma.

Methods:

All vocal process granuloma images from a digital laryngeal image library were abstracted. Granulomas were graded on a one to four system, as follows: grade one, sessile, non-ulcerative granuloma limited to vocal process; grade two, pedunculated or ulcerated granuloma limited to vocal process; grade three, granuloma extending past vocal process but not crossing midline of airway in fully abducted position; and grade four, granuloma extending past vocal process and past the midline of the airway in the fully abducted position. The granulomas were additionally graded A if unilateral and B if bilateral. Two laryngologists and two otolaryngology residents rated the granulomas on two separate occasions. Intra- and inter-observer reliability was evaluated with the kappa (κ) test statistic.

Results:

Thirty-five vocal process granulomas were identified. The percentage intra-observer agreement for the two laryngologists was 97 and 100 per cent (κ = 0.94 and 1.00, respectively). The percentage inter-observer agreement between the two laryngologists was 91 per cent (κ = 0.83). The percentage intra-observer agreement for the two residents was 89 and 91 per cent (κ = 0.83 and 0.77, respectively). The percentage inter-observer agreement between the two residents was 83 per cent (κ = 0.67).

Conclusions:

The proposed grading system for vocal process granuloma displayed excellent intra- and inter-observer reliability among residents and experienced laryngologists.
Changing practices in the consent process for nose and throat procedures: a three-year study
Authors: McDonald S E , Chadha N K , Mills R S
Published: March 2008

Objectives:

To assess elective surgery consent practices amongst senior house officers from a selection of UK ENT departments, and to compare results with those obtained in a similar survey in 2002.

Methods:

A telephone survey of senior house officers in 40 UK ENT departments was carried out to assess departmental consent policies and knowledge of complications of common ENT operations.

Results:

Over 80 per cent of the senior house officers surveyed remained responsible for obtaining consent for routine surgery. Since 2002, there had been a significant increase in the proportion of departments which: used the Department of Health model consent form; provided patient information leaflets; and had an established informed consent protocol. Senior house officers' knowledge of specific complications remained poor.

Conclusion:

There has been a small change in the practice of obtaining informed consent, in accordance with General Medical Council guidelines. Many senior house officers continue to perform this duty, however, and the majority are poorly trained.
Customised gold weight eyelid implantation in paralytic lagophthalmos
Authors: Jayashankar N , Morwani K P , Shaan M J , Bhatia S R , Patil K T
Published: March 2008

Gold eyelid implantation is widely considered the procedure of choice to reanimate the upper eyelid in paralytic lagophthalmos. Commercially supplied implants are not readily available in all places and are sometimes cumbersome to import.

Objective:

We aimed to devise a method whereby every surgeon performing gold eyelid implantation could have easy and quick access to the implant. Furthermore, we aimed to develop a means of creating an implant of the exact weight required for complete eyelid closure.

Study design and setting:

A prospective study was performed from 1997 to 2005 in a tertiary research hospital, involving 50 subjects requiring gold upper eyelid implantation and using the technique in question.

Results:

Only patients with a minimum follow up of one year were included in the study group. Symptoms improved in 96 per cent of subjects, who were able to dispense with eyedrops and eye ointments. Visual acuity improved in 92 per cent of patients. There were two extrusions amongst the early cases.

Conclusion and significance:

Customised gold eyelid implantation offers an alternative in regions where commercial implants are not easily obtained.
Relative effect of litter quality, forest type and their interaction on leaf decomposition in south-east Brazilian forests
Authors: de Toledo Castanho Camila , de Oliveira Alexandre Adalardo
Published: March 2008

Decomposition was studied in a reciprocal litter transplant experiment to examine the effects of forest type, litter quality and their interaction on leaf decomposition in four tropical forests in south-east Brazil. Litterbags were used to measure decomposition of leaves of one tree species from each forest type:Calophyllum brasiliensefrom restinga forest;Guapira oppositafrom Atlantic forest;Esenbeckia leiocarpafrom semi-deciduous forest; andCopaifera langsdorffiifrom cerradão. Decomposition rates in rain forests (Atlantic and restinga) were twice as fast as those in seasonal forests (semi-deciduous and cerradão), suggesting that intensity and distribution of precipitation are important predictors of decomposition rates at regional scales. Decomposition rates varied by species, in the following order:E. leiocarpa>C. langsdorffii>G. opposita>C. brasiliense. However, there was no correlation between decomposition rates and chemical litter quality parameters: C:N, C:P, lignin concentration and lignin:N. The interaction between forest type and litter quality was positive mainly becauseC. langsdorffiidecomposed faster than expected in its native forest. This is a potential indication of a decomposer's adaptation to specific substrates in a tropical forest. These findings suggest that besides climate, interactions between decomposers and plants might play an essential role in decomposition processes and it must be better understood.
Assessment of suspected dementia in older people
Authors: Fletcher EH , Woodford HJ , George J
Published: March 2008

Dementia is a syndrome describing progressive and largely irreversible brain dysfunction. Symptoms are varied but commonly include memory loss, mood changes and difficulties with language and judgement. Delusions and hallucinations can also occur. With disease progression there is a gradual loss of ability to perform tasks of daily living. A range of illnesses, most of which are currently incurable, can cause dementia. These include Alzheimer's disease (AD), vascular dementia (VaD), dementia with Lewy bodies (DLB) and frontotemporal dementia (FTD). Mixed patterns of dementia also exist, typically Alzheimer's disease overlapping with vascular dementia. This combination of pathologies is probably much commoner in the elderly than traditionally thought.
Quantitative Energy Dispersive X-ray Microanalysis of Electron Beam-Sensitive Alloyed Nanoparticles
Authors: Braidy Nadi , Jakubek Zygmunt J. , Simard Benoit , Botton Gianluigi A.
Published: March 2008

An energy dispersive X-ray spectrometry (EDXS) method is developed to evaluate the composition of alloyed nanoparticles (NPs) where one of the alloying elements is removed under the electron beam during microanalysis with a transmission electron microscope (TEM). The method is demonstrated for alloyed Au-Ag NPs of a diameter ranging from 6 to 20 nm produced by laser evaporation of a water-suspended Ag-Au powder mixture of varying composition. Series of EDXS spectra are recorded for 30 NPs from samples with five different Ag:Au ratios revealing Ag depletion from NPs during electron irradiation. By studying the evolution of NPs composition as a function of dose, the initial Ag content for each NP is extrapolated. The rate of Ag depletion is discussed in terms of sputtering and knock-on damage. On average, approximately one Ag atom is lost from the NP for each Ag L X-ray detected. To assess the limitations of microanalysis in these sensitive nanoscale structures, the concept of detectability limit is adapted to our method. This benchmark is then evaluated for Ag in Au-Ag NPs of various sizes and acquisition times. This study should be regarded as a guide for the design of analytical TEM measurements of beam-sensitive NPs.
Immunolabeling for Correlative Light and Electron Microscopy on Ultrathin Cryosections
Authors: Kandela Irawati K. , Bleher Reiner , Albrecht Ralph M.
Published: March 2008

Correlative labeling permits colocalization of molecular species for observation of the same sample in light (LM) and electron microscopy (EM). Myosin bands in ultrathin cryosections were labeled using both fluorophore conjugated to secondary antibody (IgG) and colloidal gold (cAu) particles conjugated to primary IgG as reporters for LM and transmission electron microscopy (TEM), respectively. This technique allows rapid evaluation of labeling via LM, prior to more time-consuming observations with TEM and also yields two complementary data sets in one labeling procedure. Quenching of the fluorescent signal was inversely related to the distance between fluorophore and cAu particles. The signal from fluorophore conjugated to secondary antibody was inversely proportional to the size of cAu conjugated to primary antibody. Where fluorophore and cAu were bound to the same antibody, the fluorescence signal was nearly completely quenched regardless of fluorophore excitation or emission wavelength and regardless of particle size, 3 nm and larger. Colloidal metal particles conjugated to primary antibody provide high spatial resolution for EM applications. Fluorophore conjugated to secondary antibody provides spatial resolution well within that of conventional fluorescence microscopy. Use of fluorescent secondary antibody moved the fluorophore a sufficient distance from the cAu particles on the primary antibody to limit quenching of fluorescence.
Probability distribution of sea surface wind stresses
Authors: Monahan Adam H.
Published: March 2008

The probability density function (pdf) of sea surface wind stresses is considered. Observed sea surface wind stresses are highly non‐Gaussian, with characteristic relationships between moments. A consideration of empirical models of sea surface wind stress pdfs built from models of sea surface vector winds demonstrates that non‐Gaussian structure in the vector winds must be accounted for to accurately characterise the observed relationships between wind stress moments. An idealised stochastic boundary layer model is shown to provide a good qualitative characterisation of these pdfs.
Microburst cusp ion precipitation observed with Reimei
Authors: Ebihara Y. , Miyoshi Y. , Asamura K. , Hirahara M.
Published: March 2008

At an altitude of 610–670 km, the Japanese satellite Reimei was the first to discover a new type of ion injections into the topside ionosphere in or in the vicinity of the cusp. These ion injections, called Microburst Cusp Ion Precipitation (MCIP), were spatially embedded into the dominant precipitation of magnetosheath‐like particles. They were observed in approximately one third of all cusp traversals, and were characterized by a relatively low energy (with less than a few hundred electron‐volts) and relatively short‐lived nature (with a typical lifetime of 1 to 2 s). The characteristic energy decreases with time (Type 1), and sometimes does not clearly exhibit energy‐time dispersion (Type 3). Only one event exhibits the characteristic energy increasing with time (Type 2). Applying the time‐of‐flight model (in which higher energy ions arrive at the observation point first) and the velocity filter model (in which the characteristic energy decreases with distance from a source field line under the influence of perpendicular drift motion), we estimated the source distance from Reimei. This paper proposes that a localized electric field, probably associated with inertial Alfvén waves and/or ionospheric Alfvén resonator, could have been generated at short intervals in time or in isolated regions at an altitude less than 3000 km, which results in MCIPs accompanied with energy‐time and energy‐pitch angle dispersions observed at an altitude of 610 to 670 km.
Assessing known pathways for HO2 loss in aqueous atmospheric aerosols: Regional and global impacts on tropospheric oxidants
Authors: Thornton Joel A. , Jaeglé Lyatt , McNeill V. Faye
Published: March 2008

We present a study of the potential importance of known reaction pathways for HO2 loss in atmospheric aerosols. As a baseline case, we calculate the reaction probability for HO2 loss by its self‐reaction in aqueous particles. Detailed calculations assessed the effects of aerosol pH, temperature, particle size, and aqueous phase diffusion limitations on the rate of HO2 loss by this process. An algebraic parameterization of the reaction probability, γHO2, due to self‐reaction is valid for aerosol pH < 6 and the existence of a homogeneous gas‐phase HOx source greater than 1 × 105 molec cm−3 s−1. In this formulation γHO2 depends strongly on particle phase, size, pH and temperature; the latter causing γHO2 > 0.1 in the upper troposphere and γHO2 < 0.01 in the extra‐polar lower troposphere. We contrast the self‐reaction pathway with catalytic oxidation by dissolved Cu ions. Using IMPROVE network data we assess the atmospheric importance and uncertainties associated with the Cu pathway. Simulations of tropospheric chemistry were performed using the GEOS‐Chem global chemical transport model with different parameterizations of γHO2. Relative to simulations where γHO2 = 0 for all aerosol types, assuming that only the aqueous‐phase self‐reaction proceeds on pollution and sea salt particles causes global annual mean differences in surface OH, HO2, and H2O2 of −1, −2, and +2%, respectively. These minor effects of heterogeneous loss are significantly different from a simulation assuming γHO2 = 0.2 on all particles, as is currently recommended, with implications for predictions of regional HOx levels, ozone production rates and their sensitivity to NOx.
Confronting surface‐ and groundwater balances on the La Rochefoucauld‐Touvre karstic system (Charente, France)
Authors: Le Moine Nicolas , Andréassian Vazken , Mathevet Thibault
Published: March 2008

The Touvre spring is the only outlet of a large karstic system, the La Rochefoucauld karst, located in the West of France. This system is particularly interesting from a modeler's point of view, for it allows to investigate how karstic losses and gains can be accounted for within a rainfall‐runoff model. Indeed, this spring is fed by the losses of three rivers, which are themselves gaged after recharging the karstic aquifer: this setting is exceptional in that simulations of surface catchment losses (estimated by the GR4J rainfall‐runoff model) can be compared with measurements of spring discharge at the outlet of the karstic system. It provides an opportunity to test the estimates of “catchment leakages”, which are often suspected but seldom measurable, against observations. We show here that the conceptualization of surface losses in the GR4J rainfall‐runoff model yields simulated leakage volumes that are consistent with the spring flow volumes and that, provided a routing store is added to GR4J to account for the specific retarding behavior of the karstic aquifer, an integrated model can be proposed to represent the behavior of the whole system adequately. The Touvre case study shows that a parsimonious, empirical rainfall‐runoff representation of a karstic system is possible. It also provides an independent corroboration for the conceptualization of surface catchment leakages proposed in the GR4J rainfall‐runoff model.