bluuebunny/crossref_metadata_2025_split huggingface dataset:
Model for the photooxidation of parylenes
Authors: Pruden K. G. , Beaudoin S. P. 
Published: April 2004

AbstractParylenes belong to a family of polymers that have been investigated for use in electronic and medical applications. The photooxidation of these materials is of interest both to prevent degradation and to induce targeted chemical changes. This article describes a transport and reaction model for the photooxidation of parylenes. This model is based on existing polymer photooxidation mechanisms that have been adapted to this system. The model has been compared with existing parylene photooxidation data for this system and shows qualitative agreement with surface oxidation profiles and oxidation depth profiles. On the basis of the results of the model comparison, it has been determined that the key parameters that appear to affect the photooxidation of parylenes are the diffusion coefficient of oxygen in these films and the concentration of oxygen initially present in these films. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2666–2677, 2004
The influence of hydrogen bonding on the preparation and mechanical properties of PS‐diblock copolymer blends
Authors: Van Casteren I. A. , Van Trier R. A. M. , Goossens J. G. P. , Meijer H. E. H. , Lemstra P. J. 
Published: April 2004

AbstractIn this article, the preparation of nanosized core‐shell particles to induce ductility in polystyrene (PS) is described. FTIR spectroscopy, solid‐state NMR spectroscopy, and DSC were used to examine the extent of miscibility of PS and poly(butylacrylate)‐b‐polyolefin diblock copolymers in a blend in which PS was chemically modified by copolymerization with 0.5–5 mol % of p‐(hexafluoro‐2‐hydroxy isopropyl) styrene (HFS). Hydrogen bonding between the hydroxyl‐groups and the carbonyl‐groups of polybutylacrylate enhanced the miscibility and lead to randomly distributed polyolefin particles surrounded by a homogeneous PBA/PS matrix. Morphological parameters such as the size of the dispersed phase or extent of interpenetration between the components are controllable simply by changing the amount of interacting groups in the blend. The mechanical properties of the prepared blends were also studied. The intrinsic deformation behavior was investigated by compression tests, whereas the microscopic mode of deformation was studied by time‐resolved small‐angle X‐ray scattering. It was shown that the macroscopic strain at break depends to a large extent on the diblock copolymer content and the degree of demixing between the rubber shell and PS matrix. Brittle behavior was observed for PS blends that contain more than 3 mol % HFS and show complete miscibility between the PS matrix and acrylate shell. For the blends showing partial miscibility, the compression tests demonstrated a pronounced decrease in strain softening with increasing diblock copolymer concentration. Furthermore, it was illustrated that dependent on the degree of demixing the microscopic deformation mode changes from crazing to cavitation induced shear yielding. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 2137–2160, 2004
Pulmonary hemorrhage/hemoptysis in children
Authors: Godfrey Simon 
Published: April 2004

AbstractPulmonary hemorrhage and hemoptysis are uncommon in childhood, and the frequency with which they are encountered by the pediatric pulmonologist depends largely on the special interests of the center to which the child is referred. In those centers caring for children with cystic fibrosis or congenital heart disease, these will be by far the most common causes of hemoptysis. Other causes of hemoptysis are far less common, such as bleeding from localized lesions in the upper airway or tracheobronchial tree. Even less common is bleeding into the lungs as part of a systemic disease, usually with renal involvement (pulmonary‐renal syndromes), such as systemic lupus erythematosis or Goodpasture's syndrome. Bleeding into the lungs in children with a bleeding diathesis probably only occurs in immunosuppressed children after transplantation. When no other cause is found for pulmonary hemorrhage, the presumed diagnosis is idiopathic pulmonary hemosiderosis. This review discusses the various causes of hemoptysis and pulmonary hemorrhage, and the appropriate investigations to aid in determining the correct diagnosis. The management and prognosis of idiopathic pulmonary hemosiderosis, based on cumulative experience from published reports, are considered in more detail. Pediatr Pulmonol. 2004; 37:476–484. © 2004 Wiley‐Liss, Inc.
Assessment of airway function in young children with asthma: Comparison of spirometry, interrupter technique, and tidal flow by inductance plethsmography
Authors: Black J. , Baxter‐Jones A.D.G. , Gordon J. , Findlay A.L. , Helms P.J. 
Published: April 2004

AbstractThe assessment of airway function in young children requires adaptation of techniques designed for adults and/or application of techniques that do not require complex respiratory maneuvers. We sought to assess two methods of measuring airway function: time to peak expiratory flows as a ratio of expiratory time (TPTEF/TE), derived from respiratory inductance plethysmography, and total respiratory resistance by the interrupter technique (Rint), both obtained during quiet tidal breathing. Both techniques were referenced to FEV1 and flow at 50% expired volume (FEF50) from conventional spirometry in 30 children aged 4–8 years (median age, 6.9; range, 4.5–8.5 years) with a physician diagnosis of asthma and who were able to perform FEV1 with a repeatability of at least 8%. TPTEF/TE and Rint were performed in random order followed by spirometry, in order to reduce the possible effects of pulmonary stretch on tidal breathing measures. Coefficients of variation (CV) and mean absolute change/baseline standard deviation were derived for each measurement. Baseline FEV1 did not correlate significantly with TPTEF/TE (r = 0.025), but did correlate with Rint (r = 0.737, P < 0.001); respective relationships for change after bronchodilator were r = 0.09 (ns) and r = 0.64 (P < 0.001). FEF50 also correlated significantly with Rint (R = 0.769, P < 0.001) but not with TPTEF/TE. FEV1 and FEF50 both increased postbronchodilator, with respective mean changes of 11.4% and 28% (P < 0.001), while Rint decreased by 24.3% (P < 0.001). No significant changes were noted for TPTEF/TE. TPTEF/TE derived from inductance plethysmography does not detect mild airway obstruction or modest changes in airway caliber following bronchodilator in young children with asthma. The interrupter technique may have a role in assessing baseline airway function and response to therapy in children unable to perform reliable spirometry, and/or when the investigator wishes to avoid the possible influence of forced maneuvers on airway tone. Pediatr Pulmonol. 2004; 37:548–553. © 2004 Wiley‐Liss, Inc.
A rapid and sensitive method for simultaneous determination of lamivudine and zidovudine in human serum by on‐line solid‐phase extraction coupled to liquid chromatography/tandem mass spectrometry detection
Authors: Estrela Rita de Cassia E. , Salvadori Myriam C. , Suarez‐Kurtz Guilherme 
Published: April 2004

AbstractA method based on solid‐phase extraction (SPE) coupled to high‐performance liquid chromatography (HPLC) with positive ion electrospray ionization tandem mass spectrometry (ESI‐MS/MS) detection was developed for the simultaneous determination of lamivudine (3TC) and zidovudine (AZT) in human serum, using didanosine (ddI) as internal standard. The acquisition was performed in multiple reaction monitoring (MRM) mode, monitoring the transitions m/z 230.0 → 111.8 for 3TC, m/z 268.1 → 126.8 for AZT, and m/z 237.2 → 136.8 for ddI. The limits of detection and quantitation were 3 and 10 ng/mL for 3TC, and 5 and 15 ng/mL for AZT. The method was linear in the studied ranges (10–1500 ng/mL for 3TC and 15–3000 ng/mL for AZT), with r2 > 0.99 for each drug, and the run time was 4 min. The intra‐assay precisions (%) were in the ranges 1.9–8.7 (3TC) and 2.2–8.9 (AZT), the inter‐assay precisions were in the ranges 2.6–9.0 (3TC) and 4.2–8.1 (AZT), and the intra‐ and inter‐assay accuracies were >97% for both drugs. The absolute recoveries were 95–99% for 3TC (45, 600 and 1200 ng/mL) and 104–112% for AZT (45, 1000 and 2400 ng/mL). The analytical method was applied to a bioequivalence study in which 24 healthy adult volunteers received single oral doses of the reference formulation and two test combined AZT/3TC tablets, in an open, three‐period, balanced, randomized, crossover protocol. Based on the 90% confidence interval of the individual ratios (test formulation/reference formulation) for Cmax (peak serum concentration) and AUC0‐inf (extrapolated area under the serum concentration vs. time curve from time zero to infinity), it was concluded that the two test formulations are bioequivalent to the reference formulation with respect to the rate and extent of absorption of both 3TC and AZT. Copyright © 2004 John Wiley & Sons, Ltd.
Rapid molecular assessment of the bioturbation extent in sandy soil horizons under pine using ester‐bound lipids by on‐line thermally assisted hydrolysis and methylation‐gas chromatography/mass spectrometry
Authors: Nierop Klaas G. J. , Verstraten Jacobus M. 
Published: April 2004

AbstractEach plant species has a unique chemical composition, and also within a given plant the various tissues differ from one another in their chemistry. These different compositions can be traced back after decay of the plant parts when they are transformed into soil organic matter (SOM). As a result, the composition of SOM reflects not only the plant origin, but also the various tissues, and the composition consequently provides an estimate of the contribution of above‐ground vs. below‐ground litter. From the latter distribution the extent of bioturbation (mixing of above‐ground litter with the mineral soil) can be assessed.Application of thermally assisted hydrolysis and methylation (THM) using tetramethylammonium hydroxide (TMAH) and subsequent analysis by gas chromatography/mass spectrometry (GC/MS) releases all typical cutin‐ and suberin‐derived aliphatic monomers (mono‐, di‐ and trihydroxyalkanoic acids, α,ω‐alkanedioic acids) as their methyl esters and/or ethers in a rapid manner. Using the distribution of ω‐hydroxyalkanoic acids that are present in pine needle cutin (C12 and C14) and not in root suberin, and those that are present in roots but not in needles (C20 and C22), the extent of bioturbation (mixing of above‐ground plant litter with the mineral soil) can be assessed. Similarly, the (9,16‐dihydroxyhexadecanoic acid+9,10,18‐trihydroxyoctadecanoic acid)/(C20 + C22 α,ω‐alkanedioic acids) ratio reflects the degree of bioturbation. Three mineral soil profiles under Corsican pine with an A horizon that exhibited extensive bioturbation phenomena, and underlying C horizons with hardly any or no bioturbation, were investigated in order to examine the applicability of such an approach. It appeared that the A horizons contained all four mentioned ω‐hydroxyalkanoic acids, while the C horizons contained virtually only the C20 and C22 members. The results not only suggest that bioturbation occurs in the A horizons, but also that possible illuviation or other transport mechanisms of ω‐hydroxyalkanoic acids seem hardly ever or never to occur, which is a prerequisite for applying this biomarker approach in assessing degrees of bioturbation. Copyright © 2004 John Wiley & Sons, Ltd.
Septin 2 phosphorylation: theoretical and mass spectrometric evidence for the existence of a single phosphorylation site in vivo
Authors: She Yi‐Min , Huang Yi‐Wei , Zhang Li , Trimble William S. 
Published: April 2004

AbstractSeptins constitute a family of conserved proteins that are required for cytokinesis in a wide range of organisms. Most cells express a set of septin proteins and these are found to assemble into hetero‐oligomeric septin complexes that appear filamentous. However, the mechanisms controlling the function and polymerization of septins are not known. We therefore examined the possibility that septins could be post‐translationally modified by phosphorylation. We present herein a combined theoretical and experimental approach for the analysis of Septin 2 (Sept2) monophosphorylation in vivo. We purified and characterized the human recombinant Sept2, a 45‐kDa protein, expressed from Sf21 insect cells. Analysis by matrix‐assisted laser desorption/ionization quadrupole time‐of‐flight mass spectrometry on the full‐length protein sequence of wild‐type Sept2 revealed a unique phosphorylation site at residue Ser248 in vivo, which is consistent with one of the twelve phosphorylation sites in the protein sequence theoretically predicted by the Netphos program. Additional predictions with the motif scan programs Scansite and Prosite suggest that the phosphorylation of wild‐type Sept2 might be a potential substrate for casein kinase 2. Site‐directed mutagenesis of residue 248 from serine to alanine abrogated this phosphorylation. The location of phosphorylation in Sept2 differs from the sites predicted for cGMP‐dependent protein kinase (PKG) phosphorylation in Septin 3, raising the possibility that different septins may undergo distinct phosphorylation events that could control their functions in important cellular processes such as neurotransmission or cytokinesis. Copyright © 2004 John Wiley & Sons, Ltd.
Quantification of cow milk adulteration in goat milk using high‐performance liquid chromatography with electrospray ionization mass spectrometry
Authors: Chen Ren‐Kun , Chang Li‐Wen , Chung Ya‐Yun , Lee Ming‐Hsung , Ling Yong‐Chien 
Published: April 2004

AbstractA method was developed for the quantification of cow milk adulteration in goat milk, based on solvent separation of whey proteins followed by high‐performance liquid chromatography with electrospray ionization mass spectrometry (HPLC/ESI‐MS). The presence of cow milk was determined using β‐lactoglobulin whey protein as the molecular marker. The adulterants were identified using both retention time and molecular mass derived from multiply charged molecular ions. Standard solutions containing cow and goat milk in different volume ratios were prepared and analyzed. Good linearity covering cow milk content from 5% and above was obtained. The proposed method identifies the adulterants using accurate molecular masses for protein identification and detects the addition of cow milk to goat milk at levels as low as 5%. Copyright © 2004 John Wiley & Sons, Ltd.
More than network structure: how knowledge heterogeneity influences managerial performance and innovativeness
Authors: Rodan Simon , Galunic Charles 
Published: April 2004

AbstractThis study deals with individual managerial performance, both overall and in generating innovation. While prior work has demonstrated a relationship between network structure and managerial performance, inadequate attention has been paid to network content. We consider several micro‐social processes that might account for differences in managerial performance, taken from economic sociology and studies of managers' exploitation of their social networks and derived from work in psychology on the genesis of ideas. We compare the influence of these mechanisms on managerial performance using a sample of 106 middle managers in a European telecommunications company. Our findings suggest that, while network structure matters, access to heterogeneous knowledge is of equal importance for overall managerial performance and of greater importance for innovation performance. Copyright © 2004 John Wiley & Sons, Ltd.
DSM-IV mental disorders and neurological complications in children and adolescents with human immunodeficiency virus type 1 infection (HIV-1)
Authors: Misdrahi D. , Vila G. , Funk-Brentano I. , Tardieu M. , Blanche S. , Mouren-Simeoni M.C. 
Published: April 2004

AbstractAimTo study the types of psychiatric problem encountered in children infected with the human immunodeficiency virus (HIV) and their relationship to central nervous system disorder and the severity of infection.Methods17 HIV-infected children presenting with psychiatric problems were included. Mental disorders were evaluated according to DSM-IV criteria. Neurological disorders and progressive encephalopathy (presence or absence) diagnosis were evaluated by clinical and radiological examination. The severity of infection was assessed by the percentage of CD4 lymphocytes.ResultsThe most frequent diagnoses were major depression (MDD: 47%) and attention deficit hyperactivity disorder (ADHD: 29%). Major depression diagnosis was significantly associated with neuroimaging or clinical neurological abnormalities (p < 0.01). In contrast, no association was found between hyperactivity diagnosed according to DSM-IV criteria and central nervous system disorder. Percentage of CD4 lymphocytes were close to 0 for more than 80% of children presenting with psychiatric complications.ConclusionThe very low % of CD4 lymphocytes of these children suggest that the appearance of a psychiatric complication should be regarded as a factor indicating severe HIV infection. Depressive disorders may be a clinical form of encephalopathy.
Risk of malignancy index in the preoperative evaluation of pelvic masses
Authors: Obeidat B.R. , Amarin Z.O. , Latimer J.A. , Crawford R.A. 
Published: April 2004

AbstractObjectives: To assess the ability of a risk malignancy index (RMI) based on serum levels of CA 125, ultrasound findings, and menopausal status to discriminate between benign and malignant pelvic masses in a particular population. Methods: A retrospective study was conducted of 100 women with pelvic masses admitted for laparotomy. The sensitivity and specificity of serum levels of CA 125, ultrasound findings, and menopausal status were calculated both separately and combined into a RMI to diagnose malignancy. Results: The RMI was more accurate than any single criterion in diagnosing malignancy. Using a cut‐off level of 200 to indicate malignancy, the RMI gave a sensitivity of 90%, specificity of 89%, positive predictive value of 96%, and negative predictive value of 78%. Conclusion: The RMI is able to correctly discriminate between malignant and benign pelvic masses. It is a simple scoring system that can be introduced easily into clinical practice to facilitate the selection of patients who would benefit from primary surgery.
The state of the art in corpus linguistics: three book-length perspectives
Authors: MUKHERJEE JOYBRATO 
Published: April 2004

Susan Hunston, Corpora in applied linguistics. Cambridge: Cambridge University Press, 2002. Hardback £40.00, ISBN 0 521 80171 0. Paperback £14.95, ISBN 0 521 80583 X. Pp. xii + 241.Charles F. Meyer, English corpus linguistics: an introduction. Cambridge: Cambridge University Press, 2002. Hardback £45.00, ISBN 0 521 80879 0. Paperback £16.95, ISBN 0 521 00490 X. Pp. xvi + 168.Gerald Nelson, Sean Wallis, and Bas Aarts, Exploring natural language: working with the British component of the International Corpus of English. Amsterdam: John Benjamins, 2002. Hardback £95.00, ISBN 90 272 4888 5. Paperback £55.00, ISBN 90 272 4889 3. Pp. xviii + 342.
A new Gray's Anatomy of English grammar
Authors: LEECH GEOFFREY 
Published: April 2004

Rodney Huddleston and Geoffrey Pullum, The Cambridge grammar of the English language. Cambridge: Cambridge University Press, 2002. Pp. xviii + 1842. Hardback, ISBN 0 521 43146 8. £120.This article reviews Huddleston & Pullum (2002) from the viewpoint of a co-author of Quirk, Greenbaum, Leech & Svartvik (1985). (This author, however, makes no claim whatsoever to represent the views of the other authors of Quirk et al.) Particular attention is paid to some of the more controversial aspects of Huddleston & Pullum's analysis. It is argued that the two grammars, although similar in their comprehensively wide coverage of English, are not strictly comparable, in that Huddleston & Pullum's grammar is more theory-oriented and Quirk et al.'s grammar is more observation-oriented. These different orientations go with different strengths and weaknesses. In some areas Huddleston & Pullum's more up-to-date account has manifest advantages over that of Quirk et al., but there are also arguably areas where Huddleston & Pullum have not moved with the times.
Recurrence Rates after Endoscopic Sinus Surgery for Massive Sinus Polyposis
Authors: Wynn Rhoda , Har‐El Gady 
Published: April 2004

AbstractBackground and objectives: Most studies on outcome after endoscopic sinus surgery (ESS) include patients with varying degrees of disease severity. Recurrence rates cited by those studies may not apply to the subset of patients with severe polyposis. Our aim is to provide reference information for recurrence rates and need for revision surgery in patients with severe disease.Study design, patients, and methods: Review of patients with severe polyposis with a minimum Lund‐McKay score of 16 and with a Kennedy computed tomography stage 3 or 4. Data collection included demographics, presence of asthma or documented allergy, history of previous surgery, extent of surgery, preoperative and postoperative management, recurrence rates, revision surgery rates, and follow‐up.Results: One hundred and eighteen records were reviewed. Fifty‐nine (50%) patients had asthma, and 93 (79%) had documented allergy. All patients required extensive bilateral nasal polypectomy, complete anterior and posterior ethmoidectomy, and maxillary sinusotomy. One hundred (85%) also had frontal or sphenoid sinusotomy. Follow‐up ranged from 12 to 168 (median 40) months. Seventy‐one (60%) developed recurrent polyposis. Fifty‐five (47%) were advised to undergo revision surgery, and 32 (27%) underwent surgery. History of previous sinus surgery or asthma predicted higher recurrence (P < .005, P < .001) and revision surgery rates (P = .02, P < .001). History of allergy also predicted recurrence and need for revision (P < .001, P < .001).Conclusions: Recurrence rates after ESS for severe polyposis are significant. In our study, patients with asthma are at higher risk of recurrence.
Epstein‐Barr Virus (EBV) Latent Membrane Protein 1 Induces Interleukin‐8 through the Nuclear Factor‐κB Signaling Pathway in EBV‐Infected Nasopharyngeal Carcinoma Cell Line
Authors: Ren Qingchun , Sato Hiroshi , Murono Shigeyuki , Furukawa Mitsuru , Yoshizaki Tomokazu 
Published: April 2004

AbstractBackground/Objectives: Nasopharyngeal carcinoma (NPC) is a highly invasive and metastatic malignant tumor and is associated with Epstein‐Barr virus (EBV) infection that exhibits type II latency. Angiogenesis is essential for tumor growth, invasion, and metastasis. Our previous studies have indicated that interleukin (IL)‐8 was over‐expressed in many NPC tissues and was found to be significantly correlated with angiogenesis by immunohistochemistry.Study Design: In vitro design.Methods: The influence of the EBV genome for IL‐8 gene expression was studied using the EBV–genome‐positive and ‐negative epithelial/NPC hybrid cell line NPC‐KT. The EBV‐positive and ‐negative clones were selected by polymerase chain reaction and in situ hybridization.Results: EBV‐positive clones expressed abundant IL‐8 mRNA compared with EBV‐negative clones. This result indicated that over‐expression of IL‐8 depended on the presence of EBV genomes in NPC‐KT cells. Two encoded genes, latent membrane protein (LMP)1 and EBV‐encoded small RNAs (EBERs), expressed in NPC were transfected in EBV‐negative NPC‐KT cells. LMP1 transactivated the IL‐8 promoter, whereas EBERs did not. Moreover, the nuclear factor (NF)‐ κB binding site in the IL‐8 promoter was essential for the response to LMP1, and the activator protein (AP)‐1 binding site played only a partial role.Conclusions: LMP1 induces IL‐8 mainly through the activation of NF‐κB and partly through AP‐1 in NPC model cell lines, NPC‐KT, and this suggests that LMP1 plays an important role in the angiogenesis of NPC.