bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ester acceleration mechanisms in phenol–formaldehyde resin adhesives
Authors: Lei Hong , Pizzi A. , Despres A. , Pasch H. , Du Guanben 
Published: February 2006

AbstractAn analysis of phenol–formaldehyde (PF) resins obtained by the addition of 0.5–5% glycerol triacetate (triacetin) as an accelerator during resin preparation showed the presence of intermediates involved in the acceleration mechanism. 13C‐NMR spectroscopy, matrix‐assisted laser desorption/ionization time‐of‐flight (MALDI‐TOF) mass spectroscopy (MS), and gel permeation chromatography allowed us to identify some of the intermediates left over in the PF resin itself. The permanence in the resin of these labile intermediates, not easily observed otherwise, appeared to be due to the reaching of the diffusion‐controlled phase of the reaction. The mechanism involved appeared considerably more complex and different from any of the mechanisms presented previously. As a consequence of the evident complexity of the mechanism, it was not really possible to advance a complete mechanism of the reaction nor determine the real cause of the increase in the strength of the final network. The mechanism involved the phenate ion of the resin to apparently give a carbonyl or carboxyl group attached to the aromatic ring. Either directly or by subsequent rapid rearrangement after the initial attack, these CO groups were found on sites different from the ortho position. The appearance gathered from NMR shift calculation indicated preferential positioning or repositioning to the para site and, surprisingly, to the meta sites of the phenolic ring. The shifts of these CO groups correspond to those of an anhydride and to no other intermediate structures previously thought of. Anhydride‐like bridges were clearly shown by MALDI‐TOF MS to contribute to oligomer structures in which linkages between phenol rings were mixed methylene bridges and anhydride bridges. These structures appeared to be temporary, possibly due to the instability of the anhydride bridges; hence, they were in small proportions at any given moment of the reaction. MALDI‐TOF analysis clearly indicated that these structures were at some moment an integral part of the structure of the liquid resin and that they existed parallel to the methylene bridges pertaining to a normal PF resin structure. Previous spectra showed that similar but not identical intermediates were present also in organic and inorganic catalyzed PF resins. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100:3075–3093, 2006
Stability of acrylonitrile/methyl vinyl ketone copolymer solutions
Authors: Hou Chen , Ying Liang 
Published: February 2006

AbstractMethyl vinyl ketone was successfully copolymerized with acrylonitrile for the first time. This was achieved with azobisisobutyronitrile as the initiator. The viscosity behavior of solutions of the acrylonitrile/methyl vinyl ketone copolymers was determined. The solution agreed with the character of Newtonian flow at the lower shearing rate. The addition of mechanical mixing obviously prevented an increase in the viscosity of the copolymer solutions. When dimethylformamide was used as an additive, the solution viscosity decreased monotonically. When H2O was used as an additive, the viscosity of the copolymer solutions decreased continuously with concentrations of H2O up to 4 wt % and then increased. The viscosity of the copolymer solutions decreased continuously with concentrations of KCl and NaCl up to 0.03 mol/L and then increased. Within the first 10 h, there was a great drop in the viscosity of the copolymer solutions containing sodium ethoxide and sodium hydroxide, and then the viscosity appeared to increase. The composition with 12 wt % acetic acid in dimethyl sulfoxide could be considered to be a Θ solvent for the acrylonitrile/methyl vinyl ketone copolymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 3377–3381, 2006
Reconciling information‐seeking behavior with search user interfaces for the Web
Authors: Rose Daniel E. 
Published: February 2006

AbstractUser interfaces of Web search engines reflect attributes of the underlying tools used to create them, rather than what we know about how people look for information. In this article, the author examines several characteristics of user search behavior: the variety of information‐seeking goals, the cultural and situational context of search, and the iterative nature of the search task. An analysis of these characteristics suggests ways that interfaces can be redesigned to make searching more effective for users.
An unusual class of PITX2 mutations in Axenfeld‐Rieger syndrome
Authors: Saadi Irfan , Toro Rafael , Kuburas Adisa , Semina Elena , Murray Jeffrey C. , Russo Andrew F. 
Published: February 2006

AbstractBACKGROUNDMutations in the PITX2 homeobox gene are known to contribute to Axenfeld‐Rieger syndrome (ARS), an autosomal‐dominant developmental disorder. Although most mutations are in the homeodomain and result in a loss of function, there is a growing subset in the C‐terminal domain that has not yet been characterized. These mutations are of particular interest because the C‐terminus has both inhibitory and stimulatory activities.METHODSIn this study we used a combination of in vitro DNA binding and transfection reporter assays to investigate the fundamental issue of whether C‐terminal mutations result in gain or loss of function at a cellular level.RESULTSWe report a new frameshift mutation in the PITX2 allele that predicts a truncated protein lacking most of the C‐terminal domain (D122FS). This newly reported mutant and another ARS C‐terminal mutant (W133Stop) both have greater binding than wild‐type to the bicoid element. Of interest, the mutants yielded ∼5‐fold greater activation of the prolactin promoter in CHO cells, even though the truncated proteins were expressed at lower levels than the wild‐type protein. The truncated proteins also had greater than wild‐type activity in 2 other cell lines, including the LS8 oral epithelial line that expresses the endogenous Pitx2 gene.CONCLUSIONSThe results indicate that the PITX2 C‐terminal domain has inhibitory activity and support the notion that ARS may also be caused by gain‐of‐function mutations. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
HLXB9 homeobox gene and caudal regression syndrome
Authors: Merello Elisa , De Marco Patrizia , Mascelli Samantha , Raso Alessandro , Calevo Maria Grazia , Torre Michele , Cama Armando , Lerone Margherita , Martucciello Giuseppe , Capra Valeria 
Published: February 2006

AbstractBACKGROUNDCaudal regression syndrome (CRS) is a congenital heterogeneous constellation of caudal anomalies that include varying degrees of agenesis of the spinal column, anorectal malformations (ARMs), genitourinary anomalies, and pulmonary hypoplasia. The combination of a particular form of hemisacrum, ARM, and presacral mass (teratoma, anterior meningocele, rectal duplication, or a combination thereof) constitutes Currarino syndrome (CS). Previous reports have shown HLXB9 to be a major causative gene for CS. The aim of our study was to reevaluate the involvement of the HLXB9 gene in a larger group of CRS cases.METHODSSSCP analysis was performed on a series of 48 CRS cases without CS. A case‐control approach was used to test whether an alteration of the length of the GCC triplets in exon 1 of the HLXB9 gene could contribute to CRS risk.RESULTSNo pathological variants of the HLXB9 gene were identified by mutational analysis. We also found no evidence that the length of the GCC triplets had any effect on the CRS risk, even when the allelic frequencies were stratified according to the presence or absence of ARMs and the type of sacral agenesis.CONCLUSIONSWe confirmed that the HLXB9 gene is not involved in the pathogenesis of CRS, and to date is known as a causative gene only for CS. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
Distal 4p microdeletion in a case of Wolf‐Hirschhorn syndrome with congenital diaphragmatic hernia
Authors: Casaccia Germana , Mobili Luisa , Braguglia Annabella , Santoro Francesco , Bagolan Pietro 
Published: February 2006

AbstractBACKGROUNDWolf‐Hirschhorn syndrome (WHS) is a well‐known genetic condition characterized by typical facial anomalies, midline defects, skeletal anomalies, prenatal and postnatal growth retardation, hypotonia, mental retardation, and seizures. Affected patients with a microdeletion on distal 4p present a milder phenotype that lacks congenital malformations. WHS is rarely associated with congenital diaphragmatic hernia (CDH), and only 8 cases are reported in the literature. In almost all cases of CDH and WHS a large deletion of the short arm of chromosome 4 is present.CASEA microdeletion of 2.6 Mb on distal 4p associated with CDH and multiple congenital malformations (i.e., cleft palate) is reported for the first time.CONCLUSIONSSuch a microdeletion should prompt a molecular study for WHS when in a fetus/newborn with CDH the association with cleft lip/palate and typical facial appearance (flat facial profile, hypertelorism) is found. Birth Defects Research (Part A), 2006. © 2006 Wiley‐Liss, Inc.
Rational design and synthesis of a double‐stranded DNA–binder library
Authors: S̆ebestík Jaroslav , Hlavác̆ek Jan , Stibor Ivan 
Published: February 2006

AbstractDescribed is a computer‐assisted rational design of a DNA–bis‐intercalator peptide library. The peptide library of 250 members was prepared and the most powerful binder identified. A value of the binding constant is almost two orders of magnitude higher than that of starting building block‐9‐aminoacridine. The binder affinity found toward calf thymus DNA is 30‐fold of that of human prion peptide 106–126. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 400–407, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Ethanol is a better inducer of DNA guanine tetraplexes than potassium cations
Authors: Vorlíčková Michaela , Bednářová Klára , Kypr Jaroslav 
Published: February 2006

AbstractGuanine tetraplexes are a biologically relevant alternative of the Watson and Crick duplex of DNA. It is thought that potassium or other cations present in the cavity between consecutive guanine tetrads are an integral part of the tetraplexes. Here we show using CD spectroscopy that ethanol induces the guanine tetraplexes like or even better than potassium cations. We present examples of ethanol stabilizing guanine tetraplexes even in cases when potassium cations fail to do so. Hence, besides the A‐form or Z‐form, ethanol stabilizes another conformation of DNA, i.e., the guanine tetraplexes. We discuss the mechanism of the stabilization. Use of ethanol will permit studies of guanine tetraplexes that cannot be induced by potassium cations or other tetraplex‐promoting agents. This work demonstrates that a still broader spectrum of nucleotide sequences can fold into guanine tetraplexes than has previously been thought. Aqueous ethanol may better simulate conditions existing in vivo than the aqueous solutions. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 253–260, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
UV‐resonance Raman spectroscopic study of human plasma of healthy donors and patients with thrombotic microangiopathy
Authors: Harz M. , Claus R. A. , Bockmeyer C. L. , Baum M. , Rösch P. , Kentouche K. , Deigner H.‐P. , Popp J. 
Published: February 2006

AbstractVarious diseases shift the composition of human plasma; hence, the relative quantification of plasma constituents offers the opportunity to use the dynamic and complex composition of plasma to gain information on novel diagnostic and prognostic factors. Since plasma contains, besides water, mostly proteins, UV‐resonance Raman spectroscopy (UVRR) seems to be a suitable method for investigating plasma. With this method the signals of aromatic amino acids and proteins are selectively enhanced. In this study an UV‐resonance Raman approach was used for the investigation of human plasma of healthy volunteers and patients with thrombotic microangiopathy. For comparison, selected plasma components were analyzed for a more detailed characterization of cryoprecipitates from human plasma. © 2006 Wiley Periodicals, Inc. Biopolymers 82:317–324, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Theoretical prediction of the basic helix types in α,β‐hybrid peptides
Authors: Baldauf Carsten , Günther Robert , Hofmann Hans‐Jörg 
Published: February 2006

AbstractThis study provides a complete overview on all possible helical‐ folding patterns, their stabilities, and their detailed molecular structure in the novel foldamer class of α,β‐hybrid peptides on the basis of ab initio molecular orbital (MO) theory. The results indicate a considerable intrinsic potential of backbone folding. As found for other peptide foldamers, representatives of mixed or β‐helices are most stable in more apolar media, whereas polar environments favor the helices with the hydrogen bonds pointing in only one direction. The theoretical results confirm the hydrogen‐bonding patterns found in the first experimental studies on these hybrid peptides. Selecting special backbone substitution patterns, the secondary structure potential of the α,β‐hybrid peptides could be of great importance for a rational peptide and protein design. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 408–413, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Cellular uptake of phosphorothioate oligonucleotide facilitated by cationic porphyrin: A microfluorescence study
Authors: Kočišová E. , Praus P. , Mojzeš P. , Sureau F. , Štěpánek J. , Seksek O. , Turpin P. Y. 
Published: February 2006

AbstractCationic 5,10,15,20‐tetrakis (1‐methyl‐4‐pyridyl) porphyrin was tested as a delivery agent for oligonucleotides. By using fluorescence microimaging, it has been shown that complexation of the porphyrin to the phosphorothioate analog of dT15 labeled by rhodamine enabled its nonendocytic penetration into the cell and regular distribution in the cytoplasm and preferentially into the nucleus. Time‐resolved microfluorescence spectroscopy revealed that the oligonucleotide integrity was kept. A small fraction of the porphyrin molecules seems to undergo change of the binding mode after internalization, probably due to duplex formation between the oligonucleotide and its cellular target sequences, or due to dissociation of the porphyrin from the oligonucleotide and subsequent interactions in the cellular environment © 2006 Wiley Periodicals, Inc. Biopolymers 82:325–328, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Enantioconvergent production of (R)‐1‐phenyl‐1,2‐ethanediol from styrene oxide by combining the Solanum tuberosum and an evolved Agrobacterium radiobacter AD1 epoxide hydrolases
Authors: Cao Li , Lee Jintae , Chen Wilfred , Wood Thomas K. 
Published: February 2006

AbstractSoluble epoxide hydrolase (EH) from the potato Solanum tuberosum and an evolved EH of the bacterium Agrobacterium radiobacter AD1, EchA‐I219F, were purified for the enantioconvergent hydrolysis of racemic styrene oxide into the single product (R)‐1‐phenyl‐1,2‐ethanediol, which is an important intermediate for pharmaceuticals. EchA‐I219F has enhanced enantioselectivity (enantiomeric ratio of 91 based on products) for converting (R)‐styrene oxide to (R)‐1‐phenyl‐1,2‐ethanediol (2.0 ± 0.2 µmol/min/mg), and the potato EH converts (S)‐styrene oxide primarily to the same enantiomer, (R)‐1‐phenyl‐1,2‐ethanediol (22 ± 1 µmol/min/mg), with an enantiomeric ratio of 40 ± 17 (based on substrates). By mixing these two purified enzymes, inexpensive racemic styrene oxide (5 mM) was converted at 100% yield to 98% enantiomeric excess (R)‐1‐phenyl‐1,2‐ethanediol at 4.7 ± 0.7 µmol/min/mg. Hence, at least 99% of substrate is converted into a single stereospecific product at a rapid rate. © 2006 Wiley Periodicals, Inc.
Free peritoneal tumour cells are an independent prognostic factor in curatively resected stage IB gastric carcinoma
Authors: Rosenberg R , Nekarda H , Bauer P , Schenck U , Hoefler H , Siewert J R 
Published: February 2006

AbstractBackgroundSeveral studies have shown that the cytological detection of free peritoneal tumour cells (FPTCs) in patients with gastric cancer indicates the presence of metastatic disease. The immunocytochemical detection of FPTCs, especially in early-stage tumours, has not been examined comprehensively.MethodPeritoneal lavage was performed in 351 patients before curative resection of a gastric carcinoma between 1987 and 2001, and an adequate sample was obtained from 346 patients. FPTCs were detected immunocytochemically using Ber-EP4 antibody. Median follow-up time was 70 months.ResultsFPTCs were detected in the lavage fluid of 74 patients (21·4 per cent) and correlated with increasing pathological tumour depth (pT) and lymph node (pN) status (P &lt; 0·001). The 5-year overall survival of patients with FPTCs was significantly worse than that of patients without FPTCs (35 versus 71·9 per cent; P &lt; 0·001). FPTCs were present in 14 (8·5 per cent) of 164 patients with stage IA or IB tumours. Although the detection of FPTCs had no prognostic significance for stage IA tumours, the presence of FPTCs in those with stage IB tumours was associated with a worse prognosis (P &lt; 0·001). Multivariate analysis identified the presence of FPTCs as an independent prognostic factor in the whole cohort and in the stage IB subgroup.ConclusionDetection of FPTCs is associated with poor prognosis even in patients with early-stage gastric cancer and should be used for risk-group stratification.
Fibrinolytic risk factor clustering and insulin resistance in healthy male relatives of men with intermittent claudication
Authors: Parry D J , Grant P J , Scott D J A 
Published: February 2006

Abstract

Background
Raised fibrinolytic factors predict cardiovascular risk in healthy subjects. The aim of this study was to measure fibrinolytic factors and insulin resistance in healthy male first-degree relatives of men with intermittent claudication younger than 65 years.

Methods
The study compared 165 healthy first-degree relatives with 165 age-, sex- and race-matched control subjects free from a personal or family history of premature cardiovascular disease. Primary outcome measures were plasminogen activator inhibitor 1 (PAI-1), tissue plasminogen activator (tPA) and D-dimer levels. Insulin resistance was estimated by Homeostasis Model Assessment. Clinical and biochemical risk factors were measured and subjects genotyped for the PAI-1 4G/5G polymorphism.

Results
First-degree relatives had significantly higher mean PAI-1 (10·23 versus 7·85 ng/ml; P = 0·024), tPA (9·98 versus 8·29 ng/ml; P &lt; 0·001) and D-dimer levels (56·6 versus 46·1 ng/ml; P = 0·004). They also had significantly higher insulin resistance (1·85 versus 1·53; P &lt; 0·001) and clustered multiple atherogenic risk factors. On multivariate analysis the association between both tPA and D-dimer levels and relative status was independent of other variables.

Conclusion
Raised levels of PAI-1, tPA, D-dimer and estimated insulin resistance were present in the healthy male first-degree relatives of men with intermittent claudication. These data support the hypothesis of fibrinolytic risk factor clustering in this high-risk population.
The management of insulinoma
Authors: Tucker O N , Crotty P L , Conlon K C 
Published: February 2006

Abstract

Background
Insulinomas are rare tumours. Their clinical presentation, localization techniques and operative management were reviewed.

Methods
An electronic search of the Medline, Embase and Cochrane databases was undertaken for articles published between January 1966 and June 2005 on the history, presentation, clinical evaluation, use of imaging techniques for tumour localization and operative management of insulinoma.

Results and conclusion
Most insulinomas are intrapancreatic, benign and solitary. Biochemical diagnosis is obtained during a supervised 72-h fast. Non-invasive preoperative imaging techniques to localize lesions continue to evolve. Intraoperative ultrasonography can be combined with other preoperative imaging modalities to improve tumour detection. Surgical resection is the treatment of choice. In the absence of preoperative localization and intraoperative detection of an insulinoma, blind pancreatic resection is not recommended.
An interactive three‐dimensional virtual body structures system for anatomical training over the internet
Authors: Temkin Bharti , Acosta Eric , Malvankar Ameya , Vaidyanath Sreeram 
Published: February 2006

AbstractThe Visible Human digital datasets make it possible to develop computer‐based anatomical training systems that use virtual anatomical models (virtual body structures—VBS). Medical schools are combining these virtual training systems and classical anatomy teaching methods that use labeled images and cadaver dissection. In this paper we present a customizable web‐based three‐dimensional anatomy training system, W3D‐VBS. W3D‐VBS uses National Library of Medicine's (NLM) Visible Human Male datasets to interactively locate, explore, select, extract, highlight, label, and visualize, realistic 2D (using axial, coronal, and sagittal views) and 3D virtual structures. A real‐time self‐guided virtual tour of the entire body is designed to provide detailed anatomical information about structures, substructures, and proximal structures. The system thus facilitates learning of visuospatial relationships at a level of detail that may not be possible by any other means. The use of volumetric structures allows for repeated real‐time virtual dissections, from any angle, at the convenience of the user. Volumetric (3D) virtual dissections are performed by adding, removing, highlighting, and labeling individual structures (and/or entire anatomical systems). The resultant virtual explorations (consisting of anatomical 2D/3D illustrations and animations), with user selected highlighting colors and label positions, can be saved and used for generating lesson plans and evaluation systems. Tracking users' progress using the evaluation system helps customize the curriculum, making W3D‐VBS a powerful learning tool. Our plan is to incorporate other Visible Human segmented datasets, especially datasets with higher resolutions, that make it possible to include finer anatomical structures such as nerves and small vessels. Clin. Anat. 267–274, 2006. © 2006 Wiley‐Liss, Inc.