bluuebunny/crossref_metadata_2025 huggingface dataset:
Influence of a series of organic and chemical substances on the translucency of resin composites
Authors: Kim Ji‐Hyung , Lee Yong‐Keun , Powers John M.
Published: September 2005

The objective of this study was to investigate the changes in the translucency of resin composites following a series of immersion treatments in organic and chemical substances. Color of resin composites was measured according to the CIELAB color scale relative to the standard illuminant D65 over a white and a black background. Translucency parameter (TP) of resin composites was calculated at baseline, and after sequential immersion: Step 1, porcine liver esterase (a substitute for a salivary esterase); Step 2, organic substances (mucin and serum) and phosphate‐buffered saline (PBS) as a control; Step 3, chemical alteration agents [chlorhexidine (CH) and carbamide peroxide (CP)]; and Step 4, 2% methylene blue. Porcine liver esterase caused small changes in TP (ΔTP = = −0.5 to 0.2). After Step 2, ΔTP values of three groups were similar in the range of −0.7 to 1.2. After Step 3, ΔTP values of all groups were small in the range of −1.5 to 2.2. After Step 4, ΔTP values were high and differences that varied by the resin composite and the immersion protocol were clearly observed (ΔTP = −13.4 to −2.5). Changes in TP were mainly influenced by resin composite. After Step 4, mucin and serum groups showed generally small changes in TP compared to PBS group. It is a possibility that the high changes in TP after immersion in methylene blue is an indication of dye absorption which might be an indication of the degree of resin composite degradation. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Enhancement in mineralization of some natural refractory organic compounds by ozonation–aerobic biodegradation
Authors: Saroj Devendra P , Kumar Arun , Bose Purnendu , Tare Vinod
Published: September 2005

Two schemes, the first involving ozonation followed by final aerobic biodegradation (phase I experiments), and the second involving initial aerobic biodegradation, followed by ozonation and subsequent final aerobic biodegradation (phase II experiments), were examined for enhanced mineralization of refractory model compounds, viz. gallic acid, tannin and lignin. In all cases, and irrespective of the applied scheme, chemical oxygen demand (COD), total organic carbon (TOC), COD/TOC ratio, and specific UV absorbance at 280 nm attributed to the model compounds decreased with application of increasing ozone dose. The residual organic matter remaining after ozonation exhibited enhanced aerobic biodegradability in all cases. Further, in all cases and irrespective of the applied scheme, the overall amount of COD and TOC removed through the combination of ozonation and biodegradation processes increased with increase in ozone dose for all three model compounds, and more than 90% COD removal could be achieved with an ozone dose of 3 mg ozone absorbed per mg initial TOC, as compared with approximately 40% COD removal when no ozone was applied. Treatment by the first scheme resulted in the fraction of starting COD removed through biodegradation decreasing with increase in ozone dose in all cases, while this fraction increased or remained constant during treatment using the second scheme. In the case of tannin and lignin, similar overall COD removal could be achieved at lower ozone doses using scheme II. Due to incorporation of the initial aerobic biodegradation step in scheme II, the ozone requirement for additional mineralization, ie mineralization over and above that achieved by aerobic biodegradation, was also lower than that in scheme I. Copyright © 2005 Society of Chemical Industry
Specificities of proteases for use in leather manufacture
Authors: Foroughi Farhad , Keshavarz Tajalli , Evans Christine S
Published: September 2005

Proteases are used in leather manufacture in the processes of soaking, unhairing and bating of hides and skins. However proteases can be relatively non‐specific in their usage, and for improved efficacy of enzyme biocatalysis within the industry, an analysis of specific activities of enzymes towards skin proteins was undertaken. Most commercial proteases for soaking showed substantial activity against the substrates elastin–Congo Red and Azocoll but little or no activity against keratin–azure and hide powder black. Enzymes used for unhairing in conjunction with 30% of the usual concentration of sulfide to effect chemical unhairing showed moderate activity against all substrates tested (selected as representative of skin proteins), while proteases used in bating showed activity against Azocoll and elastin–Congo Red but had no keratinase activity and little activity against hide powder black. Bating proteases and soaking proteases displayed similar activities at pH 8. Microbes isolated in the screening of organisms from putrefied skins included one fungal and two bacterial isolates whose extracellular enzymes had efficient unhairing activity without the addition of sulfide. Enzyme activities for these proteases included high activity measured against Azocoll with little or no activity against elastin–Congo Red, keratin–azure and hide powder black. Neither elastase nor keratinase activities were determined as being essential for unhairing. Copyright © 2005 Society of Chemical Industry
A simple model for simultaneous methanogenic–denitrification systems
Authors: Garibay‐Orijel Claudio , Ahring Birgitte K , Rinderknecht‐Seijas Noemí , Poggi‐Varaldo Héctor M
Published: September 2005

We describe a useful and simple model for studies of simultaneous methanogenic–denitrification (M–D) systems. One equation predicts an inverse relationship between the percentage of electron donor channeled into dissimilatory denitrification and the loading ratio λ given by grams degradable COD per gram nitrate‐N in the influent. It allows the determination of the extent of use of organic matter by the denitrification and the methanogenic pathways for a given concentration of nitrate salts in the influent. This equation was validated with experimental data from the literature and good agreement between predicted and experimental percentages was found. The other equation allows the calculation of the N nutrient requirements in the ammonia nitrogen form (that is, with oxidation number −3). Copyright © 2005 Society of Chemical Industry
Decolourisation of dyes and dyehouse effluent in a bubble‐column reactor by heterogeneous catalytic ozonation
Authors: Hassan M Mahbubul , Hawkyard Christopher J
Published: September 2005

The decolourisation of aqueous solutions of dyes by ozonation with various heterogeneous catalysts using a bubble‐column reactor was investigated. The catalysts studied were hydrated alumina, activated carbon and ferric oxide supported on silica. The optimum catalyst concentration and pH for decolourisation were determined in each case. Hydrated alumina and silica‐supported ferric oxide showed excellent catalytic activity under acidic conditions, whereas activated carbon was found to be effective under both acidic and alkaline conditions. In addition to studying the effect on individual dyes, tests were carried out on effluent from a commercial dyeing unit. The reaction kinetics in the presence of various catalysts were also monitored. Copyright © 2005 Society of Chemical Industry
Comparison of the surface and catalytic properties of rare earth‐promoted CaO catalysts in the oxidative coupling of methane
Authors: Rane Vilas H , Chaudhari Sopan T , Choudhary Vasant R
Published: September 2005

Rare earth (viz. La, Ce, Sm, Nd and Yb) promoted CaO catalysts have been investigated, comparing their surface properties (viz. surface area and basicity/base strength distribution) and catalytic activity/selectivity in the oxidative coupling of methane at different reaction conditions (temperatures, 650–800 °C, CH4/O2 ratios, 2.0–8.0 and space velocity, 51 360 cm3 g−1 h−1). The surface properties and catalytic activity/selectivity are strongly influenced by the rare earth promoter and its concentration. Apart from the Sm‐promoted CaO catalyst, both the total and strong basic sites (measured in terms of CO2 chemisorbed at 50° and 500 °C respectively) are decreased due to the promotion of CaO by rare earth metals (viz. La, Ce, Nd and Yb). The catalytic activity/selectivity is strongly influenced by the temperature, particularly below ⩽700 °C, whereas at higher temperature no further effect is seen. The La2O3CaO, Nd2O3CaO and Yb2O3CaO catalysts showed high activity and selectivity, and also their results are comparable. Among the catalysts, Nd‐promoted CaO (with Nd/Ca = 0.05) showed the best performance (19.5% CH4 conversion with 70.8% C2+ selectivity) in the oxidative coupling of methane. A close relationship between the surface density of total and strong basic sites (measured in terms of CO2 chemisorbed at 50° and 500 °C respectively) and the C2+ selectivity and/or C2+ yield has been observed. Copyright © 2005 Society of Chemical Industry
Chiral molecular recognition for the detection and analysis of enantiomers by mass spectrometric methods
Authors: Schug Kevin A. , Lindner Wolfgang
Published: September 2005

As of late, mass spectrometric methods for analysis of enantiomer discriminating systems have received considerable attention. In the last ten years, specific methods focused on measuring enantioselectivities via diastereomeric host–guest associations, collisional dissociation of diastereomeric complexes, and ion‐molecule reactions using chiral selectors have been developed. The ability to evaluate the performance of new chiral selector molecules by MS is particularly intriguing in this context; providing complementary technology to enantioselective gas‐ and liquid‐phase separation strategies already in place. Still, a number of question marks remain to be answered before these methods become commonplace. This review surveys the aspects of the mass spectrometric methods listed above and describes how they can be used to evaluate enantiomer discriminating systems. A short overview comparing the different ionization sources and mass analyzers which are used is also offered. Overall, we seek to address the advantages and limitations of each method, citing specific examples of their use from the literature, for the purpose of understanding what could be done to expand the scope of their implementation. In doing so, we also highlight some of those facets that relate directly to using MS for evaluating molecular recognition, and in particular, chiral molecular recognition systems.
Improved fallow with pigeon pea for soil fertility improvement and to increase maize production in a smallholder crop–livestock farming system in the subhumid zone of Ghana
Authors: Abunyewa A. A. , Karbo K. N.
Published: September 2005

Pigeon pea is cultivated by most smallholder crop–livestock farmers mainly as a border crop. It is quite often sparsely intercropped in cereal‐based cropping systems in the subhumid zone of Ghana. Management of pigeon pea and its biomass is a promising means of improving many abandoned arable fields but has not been consciously undertaken. The objective of this trial was to explore the use of pigeon pea and the management of its pruned biomass as part of an improved fallow for crop–livestock farming. Three pigeon‐pea management options and a natural fallow (two‐year fallow period) were compared in terms of maize grain yield and changes in soil organic carbon, total nitrogen and cation exchange capacity. Pigeon pea grain yield ranged between 615 and 678 kg ha−1 and 527 and 573 kg ha−1 in the first and second year of fallow, respectively. In the first year after fallow, maize grain yield ranged between 0·43 and 2·39 t ha−1 and was significantly influenced by the fallow system. There was a marked decrease in maize grain on the pigeon pea fallow plots in the second year, ranging between 50 and 38·6 per cent in Kumayili and between 42·6 and 17·6 per cent in Tingoli. After the two‐year fallow period, increase of soil organic carbon on the pigeon pea fallow plot compared with the natural fallow plot was 30·5 per cent, and there was an improvement of total nitrogen (48·5 per cent) and CEC (17·8 per cent). Copyright © 2005 John Wiley & Sons, Ltd.
Gc-Globulin and Prognosis in Acute Liver Failure
Authors: Schiødt Frank V. , Rossaro Lorenzo , Stravitz Richard T. , Shakil Obaid A. , Chung Raymond T. , Lee William M.
Published: September 2005

Serum concentrations of the actin scavenger Gc-globulin are reduced in acute liver failure (ALF). Prospectively, we tested Gc-globulin's value to predict outcome following ALF using sera from 182 patients with ALF from the U.S. ALF Study Group. Admission serum levels of Gc-globulin (normal range: 350-500 mg/L) were studied by an immunonephelometric method. The median (range) serum Gc-globulin level on admission for the entire group was 91 (5-307) mg/L. Gc-globulin levels were significantly higher in spontaneous survivors than in patients who died or underwent transplantation (113 [5-301] mg/L vs. 73 [5-307] mg/L,

P

< 0.001). Those surviving non-acetaminophen (paracetamol)-induced ALF without transplantation had higher Gc-globulin levels than nonsurvivors (102 [5-301] mg/L vs. 61 [5-232] mg/L,

P

= 0.002), whereas there was no significant difference in levels between the groups in patients with acetaminophen-induced ALF. A cutoff level of 80 mg/L in the non-acetaminophen group yielded positive and negative predictive values of 85% and 43%, respectively. The corresponding figures for the King's College criteria were 90% and 49%, respectively. In conclusion, we found that Gc-globulin levels were markedly decreased in patients with ALF; the lowest levels were observed in patients who died or were transplanted. In contrast to previous studies, this study demonstrated that Gc-globulin has prognostic value in patients with non-acetaminophen-induced ALF, in the same range as the King's College criteria. Further refinements of the assay would be necessary to make it more accurate and of practical utility.
Early Hepatic Stellate Cell Activation Predicts Severe Hepatitis C Recurrence after Liver Transplantation
Authors: Gawrieh Samer , Papouchado Bettina G. , Burgart Lawrence J. , Kobayashi Shogo , Charlton Michael R. , Gores Gregory J.
Published: September 2005

Only a subset of hepatitis C virus (HCV)-infected patients develop progressive hepatic fibrosis after liver transplantation (LT). Hepatic stellate cell (HSC) activation is a pivotal step in hepatic fibrosis and precedes clinically apparent fibrosis. We determined whether early HSC activation, measured in 4-month protocol post-LT biopsies, is predictive of subsequent development of more histologically severe recurrence of HCV. Early (4 month) post-LT HSC activation, as measured by α-smooth muscle actin (α-SMA) staining, was determined in liver biopsies from recipients with severe (fibrosis score ≥ 2, n = 13) and with mild (fibrosis score of 0, n = 13) recurrence of HCV at one-year post-LT. Immunohistochemical staining for α-smooth muscle actin (α-SMA) was used to generate HSC activation scores (regional and total). Total HSC activation scores at 4 months were similar in patients with severe and mild HCV recurrence (3.9 ± 2.0 vs. 2.7 ± 2.2,

P

= 0.2). Regional HSC activation, assessed as parenchymal (zones 1, 2, and 3) or mesenchymal (portal tracts and fibrous septa), was different between the study groups, with higher mesenchymal scores predictive of progression. No patients in the mild recurrence group had detectable mesenchymal α-SMA staining vs. 46% (6/13) of patients with severe recurrence (

P

< 0.01). Mesenchymal activation of HSC had a specificity and positive predictive value of 100% for development of progressive fibrosis in liver allografts of patients with hepatitis C.

In conclusion, early activation of mesenchymal HSCs is a marker for progressive fibrosis in patients with hepatitis C post-LT and may help select patients who would benefit from HCV or HSC-targeted therapy.
Orthotopic Liver Transplantation for Biliary Atresia
Authors: Barshes Neal R. , Lee Timothy C. , Balkrishnan Rajesh , Karpen Saul J. , Carter Beth A. , Goss John A.
Published: September 2005

Biliary atresia is the most common indication for orthotopic liver transplantation (OLT) in the pediatric population. The outcomes of liver transplantation for biliary atresia, however, have not been formally examined on a national scale. The objective of this study was to identify pretransplant variables that predict patient survival after primary liver transplantation for biliary atresia. A cohort of 1,976 pediatric patients undergoing primary liver transplantation for biliary atresia between 1/1988 to 12/2003 was enrolled from the United Network for Organ Sharing database after excluding patients with a history of multiorgan transplant or previous liver transplant. Follow-up data up to 16 years post-OLT was available. The 5- and 10-year actuarial survival rates of patients that underwent liver transplantation for biliary atresia in the United States are 87.2% and 85.8%, respectively, and the 5- and 10-year graft actuarial survival rates are 76.2% and 72.7%, respectively. Early deaths (≤90 days post-OLT) were more often caused by graft failure (

P

= 0.01), whereas late deaths (>90 days post-OLT) were more often due to malignancy (

P

< 0.01). An analysis of outcomes over time demonstrated a decrease in post-OLT survival and an increase in the number of OLTs done for biliary atresia at an increasing number of centers. A multivariate analysis revealed that cadaveric partial/reduced liver grafts, a history of life support at the time of OLT, and decreased age were independent predictors of increased post-OLT mortality. In conclusion, OLT is an effective treatment for biliary atresia. Certain pretransplant variables may help predict patient survival following liver transplantation for biliary atresia.
Appendicitis Among Liver Transplant Recipients
Authors: Abt Peter L. , Abdullah Ibrahim , Korenda Kathleen , Frank Adam , Peterman Heather , Stephenson Robert G. , Markmann James F. , Shaked Abraham , Olthoff Kim M.
Published: September 2005

Appendicitis among liver transplant recipients has not been described in the current literature. We report 8 recipients who experienced appendicitis three weeks to 181 months after liver transplantation (LT). Initial presenting findings differed from the nonimmunosuppressed population in that a majority of the patients did not have leukocytosis (>10,000 cells/mm3). Four patients experienced perforation, three of whom presented three days after the development of abdominal pain. All patients recovered after surgery without untoward sequela.
Transmission of Rabies Virus from an Organ Donor to Four Transplant Recipients
Authors: Kusne Shimon , Smilack Jerry
Published: September 2005

Abstract

Background

In 2004, four recipients of kidneys, a liver, and an arterial segment from a common organ donor died of encephalitis of an unknown cause.

Methods

We reviewed the medical records of the organ donor and the recipients. Blood, cerebrospinal fluid, and tissues from the recipients were tested with a variety of assays and pathological stains for numerous causes of encephalitis. Samples from the recipients were also inoculated into mice.

Results

The organ donor had been healthy before having a subarachnoid hemorrhage that led to his death. Encephalitis developed in all four recipients within 30 days after transplantation and was accompanied by rapid neurologic deterioration characterized by agitated delirium, seizures, respiratory failure, and coma. They died an average of 13 days after the onset of neurologic symptoms. Mice inoculated with samples from the affected patients became ill seven to eight days later, and electron microscopy of central nervous system (CNS) tissue demonstrated rhabdovirus particles. Rabies-specific immunohistochemical and direct fluorescence antibody staining demonstrated rabies virus in multiple tissues from all recipients. Cytoplasmic inclusions consistent with Negri bodies were seen in CNS tissue from all recipients. Antibodies against rabies virus were present in three of the four recipients and the donor. The donor had told others of being bitten by a bat.

Conclusions

This report documenting the transmission of rabies virus from an organ donor to multiple recipients underscores the challenges of preventing and detecting transmission of unusual pathogens through transplantation.
Activity‐unrelated neural control of myogenic factors in a slow muscle
Authors: Hyatt Jon‐Philippe K. , Roy Roland R. , Baldwin Kenneth M. , Wernig Anton , Edgerton V. Reggie
Published: September 2005

The properties of skeletal muscles are modulated by neural and nonneural factors, and the neural factors can be modulated by activity‐independent as well as activity‐dependent mechanisms. Given that daily activation of fast muscles is considerably less than of slow muscles, we hypothesized that the myogenic properties of the rat soleus (a slow muscle) would be more dependent on activity‐dependent than activity‐independent factors. Muscle mass, MyoD, and myogenin mRNA and protein levels, and satellite cell proliferation and differentiation rates (bromodeoxyuridine incorporation) were examined at 3, 14, and 28 days after either spinal cord isolation (SI, neuromuscular connectivity intact with minimal activation) or denervation (no neural influence). Soleus atrophy was similar in the SI and denervated groups at each time point, although increases in whole‐muscle expression of myogenin and, to a lesser degree, MyoD were lower (P < 0.05) in SI than denervated soleus muscles. Proliferation and differentiation of satellite cells, as well as mitotic activity of connective tissue cells, were lower (P < 0.05) in SI than denervated soleus muscles. In some instances, these changes were not observed until the later time points, i.e., 14 or 28 days. These results demonstrate that the motoneurons that innervate the slow soleus muscle have a significant modulatory influence on some muscle properties via mechanisms that are independent of activation. These activity‐independent modulatory influences, however, are less in the slow soleus than previously observed in fast muscles. Muscle Nerve, 2005
Clinical and subclinical autonomic dysfunction in chronic inflammatory demyelinating polyradiculoneuropathy
Authors: Stamboulis Eleftherios , Katsaros Nikolaos , Koutsis Georgios , Iakovidou Heleni , Giannakopoulou Anastasia , Simintzi Irene
Published: September 2005

Autonomic neuropathy, although common in Guillain–Barré syndrome, is considered rare in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and has not been systematically investigated in that disorder. The present study was aimed at determining the prevalence of autonomic dysfunction and investigating the integrity of autonomic nervous system (ANS) reflexes in CIDP. We studied 17 patients with idiopathic CIDP and 20 healthy controls. Six quantitative autonomic function tests (AFTs) were used: Valsalva ratio, 30/15 ratio, and inspiration–expiration difference for parasympathetic function; and tilt test, handgrip test, and sympathetic skin response for sympathetic function. Eleven patients had symptoms of autonomic dysfunction. AFTs were abnormal in 13 patients. Parasympathetic and sympathetic systems were affected with equal frequency. The tilt test was abnormal most frequently, followed by the 30/15 ratio. Three patients developed postural hypotension with loss of consciousness during the tilt test. Abnormality of AFTs did not correlate with the presence of dysautonomic symptoms; duration, severity, and clinical course of the disease; or with age or gender of patients. Our study suggests a higher frequency of clinical and subclinical involvement of the ANS in CIDP than previously estimated. Dysautonomic symptoms are frequent but are mild. However, upon prolonged passive standing, autonomic failure can lead to loss of consciousness. The subclinical involvement of the ANS affects mainly the sympathetic vasomotor and parasympathetic cardiovascular fibers. Muscle Nerve, 2005
Atom transfer radical polymerization of methyl methacrylate catalyzed by cobalt catalyst system
Authors: Li Zhong Hui , Zhang Yong Ming , Xue Min Zhao , Zhou Lei , Liu Yan Gang
Published: September 2005

A new catalyst system, CoCl2/tris(2‐(dimethyl amino) ethyl)amine (Me6 TREN), was used to catalyze the polymerization of methyl methacrylate (MMA) successfully through atom transfer radical polymerization mechanism. The control over the polymerization was not ideal, the molecular weight distribution of the resulting polymer (PMMA) was relatively broad (Mw/Mn = 1.63–1.80). To improve its controllability, a small amount of hybrid deactivator (FeBr3/Me6TREN or CuBr2/Me6TREN) was added in the cobalt catalyst system. The results showed that the level of control over the polymerization was significantly improved with the hybrid cobalt–iron (or cobalt–copper) catalyst system; the polydispersity index of the resulting polymer was reduced to a low level (Mw/Mn = 1.15–1.46). Furthermore, with the hybrid cobalt–iron catalyst, the dependence of the propagation rate on the temperature and the copolymerization of methacrylate (MA) with PMMA‐Br as macroinitiator were also investigated. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5207–5216, 2005
Some novel accelerating agents for nitroxide‐mediated living free‐radical polymerization
Authors: Jianying Huang , Jian Lin , Minghua Lin , Qiang Lin , Lizong Dai , Yousi Zou
Published: September 2005

Malononitrile (MN), trifluoroacetic acid anhydride, acetylacetone, acetoacetic ester, and diethyl malonate have been identified as novel rate‐accelerating additives for nitroxide‐mediated living free‐radical polymerization. Among these additives, MN has the greatest accelerating effect. Adding MN at an MN/2,2,6,6‐tetramethylpiperidine‐oxyl (TEMPO) molar ratio of 4.0 results in a nearly 20 times higher rate of polymerization of styrene (St), and adding MN at an MN/TEMPO molar ratio of 2.5 results in a nearly 15 times higher rate of copolymerization of St and methyl methacrylate. The polymerization of St proceeds in a living fashion, as indicated by the increase in the molecular weight with time and conversion and the relatively low polydispersity. The polymerization rate of St is so quick that the conversion reaches 70% within 1 h at 125 °C when the molar ratio of MN to TEMPO is 4:1. Moreover, the reaction temperature can be reduced to 110 °C. A possible explanation for this effect is that the formation of hydrogen bonds between the MN and TEMPO moiety weakens the CON bond at the end of the polymer chain. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5246–5256, 2005
Oligoethylene‐end‐capped polylactides
Authors: Abayasinghe Nilmini K. , Glaser Sibylle , Prasanna K. , Perera U. , Smith Dennis W.
Published: September 2005

Oligoethylene‐end‐capped polylactides were synthesized through the ring‐opening polymerization of L‐lactide with alcohol‐terminated oligoethylenes as macroinitiators. The polymerization of L‐lactide was carried out in bulk at 130 °C in the presence of stannous octoate and primary alcohols with four different molecular weights: 350, 425, 550, and 700 g/mol. The end‐capped copolymers that formed had a number‐average molecular weight of approximately 40,000 (weight‐average molecular weight/number‐average molecular weight = 1.7) according to gel permeation chromatography and were highly crystalline in comparison with the similarly formed homopolymer of L‐lactide. The copolymer structure was characterized by Fourier transform infrared, NMR, matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry, and differential scanning calorimetry analysis. This work focused on developing more crystallizable and hydrolytically stable polylactide derivatives that could potentially be used as compatibilizers in polylactide–polyolefin blends or as nucleating agents for poly(L‐lactide) or other polyesters. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5257–5266, 2005
Synthesis of electroluminescent copoly(aryl ether)s containing alternate 1,4‐distyrylbenzene derivatives and aromatic 1,3,4‐oxadiazole or 3,3″‐terphenyldicarbonitrile segments
Authors: Hsieh Bar‐Yuan , Yeh Kun‐Ming , Chen Yun
Published: September 2005

New copoly(aryl ether)s (P1–P3) containing alternate 2,5‐dihexyloxy‐1,4‐di(m‐ethoxystyryl)benzene (P1, P2) or 2,5‐dihexyloxy‐1,4‐distyrylbenzene (P3) chromophores and aromatic 1,3,4‐oxadiazole (P1) or 3,3″‐terphenyldicarbonitrile (P2, P3) segments were prepared by Horner reaction (P1 and P2) or nucleophilic displacement reaction (P3). They are basically amorphous materials with 5% weight‐loss temperature above 410 °C. Their absorption, photoluminescence spectra, and quantum yields are dependent on the composition of the isolated fluorophores. The emissions are exclusively dominated by 1,4‐distyrylbenzene segments via excitation energy transfer from electron‐transporting 1,3,4‐oxadiazole (P1) or 3,3″‐terphenyldicarbonitrile (P2, P3) chromophores. The HOMO and LUMO energy levels have been estimated from their cyclic voltammograms, and the observations confirm that oxidation and reduction start from the emitting 1,4‐distyrylbenzene and electron‐transporting segments, respectively, indicating that both carriers affinity can be enhanced simultaneously. Among the two‐layer PLED devices (ITO/PEDOT/P1–P3/Al), P1 exhibits the best performance with a turn‐on field of 4 × 105 V/cm and a maximum luminance of 225 cd/m2. However, P2 emits green–yellow light (555 nm), owing to the excimer emission. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5009–5022, 2005
Polyisophthalamides with heteroaromatic pendent rings: Synthesis, physical properties, and water uptake
Authors: Ferreiro Juan J. , de la Campa Jose G. , Lozano Angel E. , de Abajo Javier
Published: September 2005

A set of novel aromatic polyamides containing pyridine pendent groups was prepared from aromatic diamines and new monomers that are 5‐substituted derivatives of isophthalic acid bearing nicotinamide, isonicotinamide, or picolinamide groups. The polymers were obtained in high yield and high molecular weight by the phosphorylation method of polycondensation. They were characterized by spectroscopic and chromatographic methods and several of their properties were investigated. All of the polymers were soluble in polar aprotic solvents and gave films of good mechanical properties. Glass transition temperatures were higher than that of the reference polymer, poly(m‐phenyleneisophthalamide) (IP‐MPD), while the thermal resistance, defined by the initial decomposition temperature observed by thermogravimetry, was in the range 370–420 °C, lower by 30–70 °C than that of IP‐MPD. The presence of a pendent pyridine group and an additional amide side group per repeat unit made the polymers essentially amorphous and greatly improved their abilities to absorb water in comparison with nonsubstituted polyamides. Water uptake values up to 15% were observed at 65% relative humidity. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5300–5311, 2005
Curcumin: A naturally occurring long‐wavelength photosensitizer for diaryliodonium salts
Authors: Crivello James V. , Bulut Umut
Published: September 2005

Curcumin, a naturally occurring, intensely yellow dye extracted from the spice turmeric, is an efficient photosensitizer for diaryliodonium salt photoinitiators at wavelengths ranging from 340 to 535 nm. With curcumin as a photosensitizer, it is possible to carry out the cationic photopolymerization of a wide variety of epoxide, oxetane, and vinyl monomers with long‐wavelength UV and visible light. An example of the photopolymerization of an epoxide monomer with ambient solar irradiation is provided. Several other curcumin analogues were synthesized, and their use as photosensitizers is examined. With such photosensitizers, the range of spectral sensitivity can be extended well into the visible region of the electromagnetic spectrum. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5217–5231, 2005
High performance benzoxazine monomers and polymers containing furan groups
Authors: Liu Ying‐Ling , Chou Ching‐I
Published: September 2005

Furan‐containing benzoxazine monomers, 3‐furfuryl‐3,4‐dihydro‐2H‐1,3‐benzoxazine (P‐FBz) and bis(3‐furfuryl‐3,4‐dihydro‐2H‐1,3‐benzoxazinyl)isopropane (BPA‐FBz), were prepared using furfurylamine as a raw material. The chemical structures of P‐FBz and BPA‐FBz were characterized with FTIR, 1H NMR, elemental analysis, and mass spectrometry. Formation of furfurylamine Mannich bridge networks in the polymerizations of P‐FBz and BPA‐FBz increased the cross‐linking densities and thermal stability of the resulting polybenzoxazines. P‐FBz‐ and BPA‐FBz‐based polymers also exhibited high glass transition temperatures above 300 °C, high char yields, and low flammability with limited oxygen index values of 31. The dielectric (Dk = 3.21–3.39) and mechanical properties (high storage modulus of 3.0–3.9 GPa and low coefficient of thermal expansion of 37.7–45.4 ppm) of the P‐FBz‐ and BPA‐FBz‐based polymers were superior or comparable to other polybenzoxazines. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5267–5282, 2005
N‐chloro amides, lactams, carbamates, and imides. New classes of initiators for the metal‐catalyzed living radical polymerization of methacrylates
Authors: Percec Virgil , Grigoras Cristian
Published: September 2005

Metal‐catalyzed living radical polymerization of methyl methacrylate initiated with N‐chloro amides (N‐chloro N‐ethyl propionamide, N‐chloro benzanilide, N‐chloro methylbenzamide, and N‐chloro acetanilide), lactams (N‐chloro caprolactam and N‐chloro 2‐pyrrolidinone), carbamates or urethanes (N‐chloro ethylcarbamate or N‐chlorourethane), imides (N‐chloro phtalimide, N‐chloro succinimide, trichloroisocyanuric acid, and N‐chloro saccharin) and catalyzed with the self‐regulated catalytic system Cu2S/2,2′‐bipyridine is reported. The initiation efficiency of these initiators is determined by their structure. Regardless of the initiator efficiency, in all cases, poly (methyl methacrylate) with narrow molecular weight distribution and functionalized chain‐ends was obtained. These new classes of initiators open new strategies for the functionalization of polymer chain‐ends and for the synthesis of complex architectures by graft copolymerization initiated from N‐chloro proteins, aliphatic, aromatic and semiaromatic polyamides, and polyurethanes. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 5283–5299, 2005
Deformation behavior of electrospun poly(L‐lactide‐co‐ε‐caprolactone) nonwoven membranes under uniaxial tensile loading
Authors: Inai R. , Kotaki M. , Ramakrishna S.
Published: September 2005

Biodegradable poly(L‐lactide‐co‐ε‐caprolactone) copolymers with different L‐lactide (LLA)/ε‐caprolactone (CL) ratios of 75/25 and 50/50 were electrospun into fine fibers. The deformation behavior of the electrospun membranes with randomly oriented structures was evaluated under uniaxial tensile loading. The electrospun membrane with a higher LLA content showed a significantly higher tensile modulus but a similar maximum stress and a lower ultimate strain in comparison with the membrane with a lower LLA content. The beaded fibers that formed in the membranes caused lower tensile properties. X‐ray diffraction and differential scanning calorimetry results suggested that the electrospun fine fibers developed highly oriented structures in CL‐unit sequences during the electrospinning process even though the concentration was only 25 wt %. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3205–3212, 2005
Synergistically toughening high‐density polyethylene with calcium carbonate and elastomer
Authors: Xie Tingxiu , Liu Hongzhi , Ou Yuchun , Yang Guisheng
Published: September 2005

The microstructure, impact strength, and rheological properties of blends consisting of high‐density polyethylene (HDPE) and maleated poly (ethylene‐octene) (POEg) and/or calcium carbonate (CaCO3) were investigated. The improvement of impact strength of HDPE/POEg was limited due to the high miscibility between them. The introduction of CaCO3 had a negative impact on the toughness of the matrix because of the poor interfacial adhesion. In ternary blends of HDPE/POEg/CaCO3, an elastomer layer was formed around CaCO3 particles due to the strong interaction between POEg and CaCO3, which improves the HDPE‐CaCO3 interfacial strength and the toughness of the blends. A significant enhancement of dynamic viscosity, storage modulus, and the low‐shear viscosity were observed as the results of the high miscibility of HDPE with POEg and strong interaction between POEg and CaCO3. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 3213–3221, 2005
Processability of a metallocene‐catalyzed linear PE improved by blending with a small amount of UHMWPE
Authors: Aguilar M. , Martín S. , Vega J. F. , Muñoz‐Escalona A. , Martínez‐Salazar J.
Published: September 2005

The processability of a metallocene‐catalyzed polyethylene blended in the melt with low amounts of ultra‐high molecular weight polyethylene was evaluated. Our morphological and thermal studies revealed that the blends were structurally heterogeneous, formed by a matrix of metallocene polyethylene and homogeneously distributed particles of ultra‐high molecular weight material. The visible particles were smaller than those of the reactor powder. Also observed was some degree of interaction between both phases. Rheological data indicated an intense effect of morphology on viscoelastic functions, beyond that expected for a system composed of noninteractive phases. Collectively, our findings suggest the existence, to some extent, of a homogeneous phase at the molecular level composed of a fraction of ultra‐high molecular weight species and metallocene polyethylene. This gives rise to a striking behavior during processing in that the blends show improved extrusion performance the higher their ultra‐high molecular weight polyethylene content. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 2963–2971, 2005
Multidimensional Pattern Recognition and Classification of White Blood Cells Using Support Vector Machines
Authors: Adjouadi Malek , Zong Nuannuan , Ayala Melvin
Published: September 2005

This study introduces a new algorithm to optimize the pattern recognition of different white blood cell types in flow cytometry. The behavior of parametric data clusters in a multidimensional space is analyzed using the learning system known as Support Vector Machines (SVM). Beckman‐Coulter Corporation supplied flow cytometry data of numerous patients to be used as training and testing sets for the algorithm. Subsequently, the characteristics of the cells provided in these sets were used to train a SVM based classifier. The objective in developing this algorithm was to identify the category of a given blood sample and provide information to medical doctors in the form of diagnostic references for a specific disease state, lymphocytic leukemia. With the application of the hypothesis space, the learning bias and the learning algorithm, the SVM classifier was successfully trained to evaluate misclassification ratios in flow cytometry data in an effort to recognize abnormal blood cell patterns and address the ubiquitous problem of data overlap through the use of the maximal margin classifier.
A Sampling Approach for Evaluating Particle Loss During Continuous Field Measurement of Particulate Matter
Authors: Noble Christopher A. , Lawless Philip A. , Rodes Charles E.
Published: September 2005

A method for evaluating sample bias in field measurements is presented. Experiments were performed in the field and laboratory to quantify the bias as a function of particle size for the scanning mobility particle sizer and the aerodynamic particle sizer. Sources of bias and sample loss considered in this work were sampling line loss, instrumental differences and inlet efficiencies. Measurement of the bias and sample loss allow for correction of the data acquired in the field, so as to obtain more representative samples of atmospheric concentrations. Substantial losses of fine and ultrafine particle count were observed, with sampling line losses ranging from 10–50 %, dependent on particle size. Only minor line losses were observed for coarse particles (approximately 5 %) because the sampling line was oriented vertically.

Please note: corrected DOI, in print wrong DOI (10.1002/ppsc.200400939)
Investigation of molecular size of transcription factor TFIIE in solution
Authors: Itoh Yoshiyuki , Unzai Satoru , Sato Mamoru , Nagadoi Aritaka , Okuda Masahiko , Nishimura Yoshifumi , Akashi Satoko
Published: September 2005

Human general transcription factor IIE (TFIIE), a component of a transcription preinitiation complex associated with RNA polymerase II, was characterized by size‐exclusion chromatography, mass spectrometry, analytical ultracentrifugation, and small‐angle X‐ray scattering (SAXS). Recombinant human TFIIE was purified to homogeneity and shown to contain equimolar amounts of TFIIEα (50 kDa) and TFIIEβ (35 kDa) by SDS‐PAGE. In the analysis of size‐exclusion chromatography of the purified sample, as already reported, TFIIE was shown to be a 170‐kDa α2β2 heterotetramer. However, by using electrospray ionization mass spectrometry the purified sample gave the molecular mass of 84,152 ± 5, indicating that TFIIE is an αβ heterodimer but not a heterotetramer. Analytical ultracentrifugation experiment of TFIIE provided that only a single component with the molecular mass of ca. 80,000 existed in solution, also suggesting an αβ heterodimer. In addition, its extraordinarily rod‐like molecular shape was confirmed by SAXS. It is likely that the rod‐like molecular shape of TFIIE has misled larger molecular size in size‐exclusion chromatography, which was calibrated by globular proteins. It is demonstrated that TFIIE exists as a heterodimer under our present conditions in solution, although two molecules of heterodimer might be required for the formation of the preinitiation complex with RNA polymerase II for starting the transcription process. Proteins 2005. © 2005 Wiley‐Liss, Inc.
A multiple testing procedure to associate gene expression levels with survival
Authors: Jung Sin‐Ho , Owzar Kouros , George Stephen L.
Published: September 2005

In many microarray studies the primary objective is to identify, from a large panel of genes, those which are prognostic markers of a censored survival endpoint such as time to disease recurrence or death. Often, these genes are considered prognostic in that their respective expressions are associated with the survival endpoint of interest. To assess this association requires specifying an appropriate measure of association, a suitable test statistic and, as the number of genes is large, proper handling of multiplicity issues. In this paper, we will address these issues by utilizing a general correlation measure, a non‐parametric test statistic, and control of the family‐wise error rate by employing permutation resampling. Comprehensive simulation studies are conducted to investigate the statistical properties of the proposed procedure. The proposed method is applied to a recently published data set on patients with lung cancer. Copyright © 2005 John Wiley & Sons, Ltd.
A design of phase II cancer trials using total and complete response endpoints
Authors: Lu Ying , Jin Hua , Lamborn Kathleen R.
Published: September 2005

Phase II clinical trials in oncology are used for initial evaluation of the therapeutic efficacy of a new treatment regimen. Simon's two‐stage design based on total response (TR) rate is commonly used for such trials. Several authors have proposed alternative strategies to consider either response and toxicity or response and early progression. Because TR consists of both partial response (PR) and complete response (CR) and these two types of responses have different effects on subsequent patient outcome, Lin and Chen proposed a flexible design that is based on a weighted average of PR and CR rates as a way to recognize the differential significance of the two levels of response. Panageas and colleagues, on the other hand, used a trinomial model and direct search to consider a rejection region for PR and CR separately. In this paper, we reformat their hypotheses to assess efficacy based on TR and CR. A new two‐stage optimum phase II trial design based on TR and CR is developed. We provide guides on searching the stopping and rejecting regions and on determining sample size. An example of a phase II trial for glioblastomas treatment is presented. In this trial, physicians would be interested in either stable disease (SD), PR, or CR as an indication of efficacy. However, because PR and CR rarely occur, observation of any PR or CR will lean towards acceptance of the treatment. Our design has the advantage of being close to the traditional Simon two‐stage design while still having the flexibility to treat responses (PR and CR in this example) differently than SD. Copyright © 2005 John Wiley & Sons, Ltd.
Fetal echocardiographic evaluation of atrial morphology and the prediction of laterality in cases of heterotaxy syndromes
Authors: Berg C. , Geipel A. , Kohl T. , Smrcek J. , Germer U. , Baschat A. A. , Hansmann M. , Gembruch U.
Published: September 2005

Objective

To evaluate whether abnormal atrial morphology, which is well recognized in autopsy series, is detectable by fetal echocardiographic examination of the four‐chamber view, and can therefore be utilized to differentiate left from right isomerism in heterotaxy syndromes.

Methods

This study was a retrospective review of 30 cases with prenatally diagnosed heterotaxy syndromes. Ultrasound video recordings and still images were reviewed with respect to atrial morphology in the four‐chamber view. In 25 cases the morphology of both atria was sufficiently well visualized on the recordings to be evaluated and only these were included in the study.

Results

Two types of atrial morphology were distinguished in our cohort: a sickle‐shape with the tip pointing laterally and apically, and a blunt shape resembling the usual atrial appearance in the four‐chamber view. Nineteen out of the 25 cases (76%) presented with isomerism of the atria in the four‐chamber view. Thirteen had bilateral sickle‐shaped atrial morphology, all associated with left isomerism. Six had bilateral blunt‐shaped atrial morphology, all associated with right isomerism. The atria of the remaining six cases were not isomeric, the right atrium being sickle‐shaped and the left blunt‐shaped. Five of the latter cases were associated with left and one with right isomerism.

Conclusions

The majority of prenatally diagnosed heterotaxy syndromes seem to present with isomeric atrial morphology in the four‐chamber view. In these cases a differentiation between left and right isomerism can be based on the two distinct types of atrial morphology. This may further enhance the prenatal differentiation of these syndromes. Copyright © 2005 ISUOG. Published by John Wiley & Sons, Ltd.