bluuebunny/crossref_metadata_2025 huggingface dataset:
Measurement and modeling of the toxicity of binary mixtures in the nematode Caenorhabditis elegans—a test of independent action
Authors: Martin Heather L. , Svendsen Claus , Lister Lindsay J. , Gomez-Eyles Jose L. , Spurgeon David J.
Published: August 2008

Ecological risk assessments must increasingly consider the effects of chemical mixtures on the environment as anthropogenic pollution continues to grow in complexity. Yet testing every possible mixture combination is impractical and unfeasible; thus, there is an urgent need for models that can accurately predict mixture toxicity from single-compound data. Currently, two models are frequently used to predict mixture toxicity from single-compound data: Concentration addition and independent action (IA). The accuracy of the predictions generated by these models is currently debated and needs to be resolved before their use in risk assessments can be fully justified. The present study addresses this issue by determining whether the IA model adequately described the toxicity of binary mixtures of five pesticides and other environmental contaminants (cadmium, chlorpyrifos, diuron, nickel, and prochloraz) each with dissimilar modes of action on the reproduction of the nematode Caenorhabditis elegans. In three out of 10 cases, the IA model failed to describe mixture toxicity adequately with significant or antagonism being observed. In a further three cases, there was an indication of synergy, antagonism, and effect-level–dependent deviations, respectively, but these were not statistically significant. The extent of the significant deviations that were found varied, but all were such that the predicted percentage effect seen on reproductive output would have been wrong by 18 to 35% (i.e., the effect concentration expected to cause a 50% effect led to an 85% effect). The presence of such a high number and variety of deviations has important implications for the use of existing mixture toxicity models for risk assessments, especially where all or part of the deviation is synergistic.
Wastewater garden—a system to treat wastewater with environmental benefits to community
Authors: Nair Jaya
Published: August 2008

Many communities and villages around the world face serious problems with lack of sanitation especially in disposing of the wastewater—black water and grey water from the houses, or wash outs from animal rearing sheds. Across the world diverting wastewater to the surroundings or to the public spaces are not uncommon. This is responsible for contaminating drinking water sources causing health risks and environmental degradation as they become the breeding grounds of mosquitoes and pathogens. Lack of collection and treatment facilities or broken down sewage systems noticed throughout the developing world are associated with this situation.

Diverting the wastewater to trees and vegetable gardens was historically a common practice. However the modern world has an array of problems associated with such disposal such as generation of large quantity of wastewater, unavailability of space for onsite disposal or treatment and increase in population. This paper considers the wastewater garden as a means for wastewater treatment and to improve the vegetation and biodiversity of rural areas. This can also be implemented in urban areas in association with parks and open spaces. This also highlights environmental safety in relation to the nutrient, pathogen and heavy metal content of the wastewater. The possibilities of different types of integration and technology that can be adopted for wastewater gardens are also discussed.
Development of the Sulphidogenesis Cum Ammonia Removal Process for treatment of tannery effluent
Authors: Sabumon P. C.
Published: August 2008

The present paper describes the development of Sulphidogenesis Cum Ammonia Removal Process (SCARP) with a simple sulphide inhibition control. The process was developed using synthetic effluent and its application for treatment of primary treated tannery effluent was demonstrated. This paper also discusses the effects of HRT and loading rates. The developed SCARP could treat efficiently the primary treated tannery effluent with influent concentrations of COD, SO42− and NH4+ equal to 3,900 mg/L, 3,000 mg/L and 300 mg/L, respectively. An HRT of 10.5 hours was found to be adequate for COD, NH4-N and SO42− loading rates of 8.9 kg COD/m3/d, 0.68 kg NH4+/m3/d, 6.84 kg SO42−/m3/d, respectively. The overall removal efficiencies of COD, NH4-N and SO42− for the above loading rates were in the ranges of 90.8–91.8%, 84–88.3% and 64.2–70.2%, respectively. The system performance was satisfactory for different loading rates and low COD/SO42− ratios. The developed SCARP has good potential as a cost effective alternative treatment process to existing extended aeration process with nitrification–denitrification for the secondary treatment of tannery effluent.
Removal of xenobiotics in a two phase sequencing batch reactor: kinetics and modelling
Authors: Tomei M. C. , Annesini M. C.
Published: August 2008

The objectives of the paper are to verify the potentialities of a sequential two phase partitioning bioreactor in degrading xenobiotics and to evaluate the kinetic parameters for modelling the system. The target compound investigated was the 4-nitrophenol. Preliminary tests were carried out to define the solvent most appropriate for the compound. Among the three investigated solvents 1-undecanol, 2-undecanon and oleyl alcohol, the 2-undecanon was chosen because of the higher partition coefficient of 30 and the negligible formation of emulsions. Moreover, the tested solvent showed satisfactory “biocompatibility” characteristics for the biomass with minor effects on the intrinsic kinetics. Parallel batch kinetic tests were then performed with the conventional one phase and the two phase systems. In the two phase system the biomass is exposed for all the time to 4NP concentrations that are significantly lower if compared to the conventional system and, for the highest concentration (450 mg/l) in the two phase system a reduction of the reaction time is observed depending on the biomass concentration. Kinetic parameters were also evaluated in both cases by fitting of the experimental data with a modified form of the Haldane equation.
Effect of heterotrophic growth on nitritation/anammox in a single sequencing batch reactor
Authors: Udert Kai M. , Kind Elija , Teunissen Mieke , Jenni Sarina , Larsen Tove A.
Published: August 2008

The combination of nitritation and autotrophic denitrification (anammox) in a single sequencing batch reactor (SBR) is an energy efficient process for nitrogen removal from high-strength ammonia wastewaters. So far, the process has been successfully applied to digester supernatant. However, the process could also be suitable to treat source-separated urine, which has very high ammonium and organic substrate concentrations (up to 8,200 gN/m3 and 10,000 gCOD/m3). In this study, reactor performance was tested for digester supernatant and diluted source-separated urine. Ammonium concentrations in both solutions were similar (between 611 and 642 gN/m3), thus reactor performance could be directly compared. Differences were mainly due to higher activity of heterotrophic bacteria in urine. Nitrogen removal was slightly higher for source-separated urine, because heterotrophic bacteria denitrified the nitrate that was produced by anammox bacteria. In spite of higher heterotrophic growth with source-separated urine, calculated sludge concentrations at steady state were higher with digester supernatant due to accumulation of inert particulate organic matter from the influent. Although the sludge concentrations are less problematic for source-separated urine, process instabilities are more likely, because lower pH values are reached and heterotrophic denitrification can cause sudden increases of nitrite concentrations and/or nitric oxide. Both compounds inhibit aerobic ammonium oxidizing bacteria, heterotrophic bacteria and, most importantly, anammox bacteria. Nitrite and nitric oxide production by heterotrophic denitrification must be better understood to optimize nitritation/anammox for source-separated urine.
Molecular and biokinetic characterization of methylotrophic denitrification using nitrate and nitrite as terminal electron acceptors
Authors: Baytshtok Vladimir , Kim Sungpyo , Yu Ran , Park Hongkeun , Chandran Kartik
Published: August 2008

Although methanol is a widely employed carbon source for denitrification, relatively little is known on the abundance and diversity of methylotrophic bacteria in activated sludge. The primary aim of this study was to specifically identify bacteria that metabolized methanol in a sequencing batch denitrifying reactor (SBDR), using a novel technique, stable isotope probing (SIP) of 13C labeled DNA. A secondary aim was to quantitatively track dominant methylotrophic bacteria in the SBDR exposed to different terminal electron acceptors. SIP enabled 13C 16S rDNA clone libraries revealed that SBDR methylotrophic populations were related to Methyloversatilis spp. and Hyphomicrobium spp. Based on newly developed quantitative polymerase chain reaction (qPCR) assays, Hyphomicrobium spp. were more abundant than Methyloversatilis spp. throughout the period of SBDR operation. The relative population abundance was stable despite a shift in electron acceptor from nitrate to nitrite (keeping the same methanol dose). However, the shift to nitrite resulted in a significant decrease in denitrification biokinetics on both nitrate and nitrite.
Optimisation of sanitary landfill leachate treatment in a sequencing batch reactor
Authors: Spagni A. , Marsili-Libelli S. , Lavagnolo M. C.
Published: August 2008

A bench-scale SBR was operated for almost three years in an attempt to optimise the treatment of leachates generated in old landfill. The results of the first two years were used to design a monitoring and control system based on artificial intelligence concepts. Nitrogen removal was optimized via the nitrite shortcut. Nitrification and N removal were usually higher than 98% and 90%, respectively, whereas COD (of the leachate) removal was approximately 30–40%. The monitoring and control system was demonstrated capable of optimizing process operation, in terms of phase length and external COD addition, to the varying loading conditions. Using the control system developed, a significant improvement of the process was obtained: COD and N load were increased (HRT decrease) and a significant decrease (approximately 34%) of the ratio of COD added to N leachate content was observed.
Calcium phosphate precipitation in a SBR operated for EBPR: interactions with the biological process
Authors: Barat R. , Montoya T. , Borras L. , Ferrer J. , Seco A.
Published: August 2008

The aim of this paper is to study the precipitation process in a sequencing batch reactor (SBR) operated for EBPR (enhanced biological phosphorus removal) and the possible effects of this phosphorus precipitation in the biological process. Four experiments were carried out under different influent calcium concentration. The experimental results and the equilibrium study, based on the Saturation Index calculation, confirm that the process controlling the calcium behaviour in a SBR operated for EBPR is the calcium phosphate precipitation. This precipitation takes place at two stages initially precipitation of the ACP and later crystallization of HAP. Also the accumulation of phosphorus precipitated was observed when the influent Ca concentration was increased. In all the experiments the influent wastewater ratio P/COD was kept constant. It has been observed that at high Ca concentration the amount of poly-P granules decrease, decreasing the ratio between phosphate release and acetate uptake (Prel/Acuptake). Changes on PAO and GAO populations during the experimental period were ruled out by means of methilene blue stains for poly-P detection. These results confirmed the phosphate precipitation as a process that can affect to the PAO metabolism and the EBPR performance.
Intelligent monitoring networks – transformation of data into information for water management
Authors: Winkler S. , Zessner M. , Saracevic E. , Fleischmann N.
Published: August 2008

The EU-WFD requires certain monitoring tasks, which yet cannot be fulfilled by automated monitoring devices. Nevertheless, the technical progress of recent years allows monitoring station designs, which enable long-term field application under reasonable maintenance demand. State-of-the-art monitoring stations allow the setup and operation of intelligent monitoring networks, which deliver quality proved and utilisable information to the end-user as opposed to a collection of time-series. Based on a full-scale example monitoring station design, long-term observations and possible ways of (automated) data interpretation are discussed.
Effect of salinity on the activity, settling and microbial community of activated sludge in sequencing batch reactors treating synthetic saline wastewater
Authors: Wu G. , Guan Y. , Zhan X.
Published: August 2008

The effects of salinity on the activity in nutrient removal, settling and microbial community of activated sludge in sequencing batch reactors (SBRs) treating synthetic saline wastewater were investigated. Two SBRs, one treating synthetic saline wastewater (the N-Reactor, with NaCl addition) and the other treating fresh synthetic wastewater (the C-Reactor, without NaCl addition), were operated for 68 days. Three salinities (in terms of concentrations of NaCl)—10, 20 and 40 g NaCl/l—were examined. The microbial activity described with the specific glucose utilization rate, specific nitritation and nitratation rates, and specific phosphorus release and uptake rates, was inhibited in the N-Reactor, in comparison with that in the C-Reactor, except that the specific nitritation and nitratation rates were improved at the salinity of 10 g NaCl/l. The sludge yield coefficient decreased at salinities of 10 and 20 g NaCl/l but it rose at the salinity of 40 g NaCl/l. The settling of activated sludge flocs, in terms of the sludge volume index (SVI), was improved by adding NaCl. Particularly in the first 5 minutes during the SVI measurement, activated sludge flocs in the N-Reactor settled much faster than those in the C-Reactor. However, the effluent from the N-Reactor contained higher suspended solids than the effluent from the C-Reactor. The microbial diversity decreased with increasing the salinity, and the microbial community structure was greatly influenced by the salinity. Bacteriodetes and Actinobacteria were the dominant phylums detected with molecular fingerprinting techniques.
Factors Predictive of Student Completion in a Collegiate Honors Program
Authors: Campbell K. Celeste , Fuqua Dale R.
Published: August 2008

This study identified factors that were potential predictors of student completion in a collegiate honors program, evaluated the relative predictive importance of these factors, and used them to describe how the completion groups differed. Records were examined from 336 freshman honors program participants at a large, Midwestern, public university. After five years, the students were classified into three completion groups: completers ( n = 62), partial completers ( n = 73), and noncompleters ( n = 201). Using an initial set of 16 pre- and post-college-entry variables that were grounded in Tinto's (1993) model of institutional departure, preliminary univariate and subsequent multivariate discriminant analyses resulted in completion-group prediction with 54.28% accuracy. The most important discriminating variables were the high school GPA, high school class rank, first-semester college GPA, gender, and initial housing assignment (honors housing or other). Implications focus on the improvement of completion rates through informed selection and support of honors program students.
Restoration of Hypoglycemia Awareness After Islet Transplantation
Authors: Leitão Cristiane B. , Tharavanij Thipaporn , Cure Pablo , Pileggi Antonello , Baidal David A. , Ricordi Camillo , Alejandro Rodolfo
Published: August 2008

OBJECTIVE—To determine the impact of islet transplantation (ITx) on hypoglycemia awareness in patients with unstable type 1 diabetes and its relation to islet function.

RESEARCH DESIGN AND METHODS—A total of 31 ITx recipients were studied. Hypoglycemia unawareness was assessed using the Clarke hypoglycemic score (0 = no hypoglycemia; ≥4 = hypoglycemia unawareness). Subjects were grouped based on graft function: off-insulin (n = 8), graft dysfunction (on-insulin and stimulated C-peptide ≥0.3 ng/ml, n = 13), and graft failure (stimulated C-peptide <0.3 ng/ml, n = 10, evaluated 11.5 ± 14.5 months after graft failure).

RESULTS—The hypoglycemia score improved after ITx when compared with baseline values (before vs. after: 5.29 ± 1.51 vs. 1.35 ± 1.92, P < 0.001). This result was sustained even after patient stratification based on islet function (pre vs. post off-insulin: 5.63 ± 2.00 vs. no hypoglycemia reported; graft dysfunction: 5.31 ± 1.49 vs. 1.15 ± 1.63, P < 0.001; and graft failure: 5.00 ± 1.16 vs. 2.70 ± 2.26, P = 0.014).

CONCLUSIONS—The improved metabolic control achieved with ITx can restore hypoglycemia awareness in patients with type 1 diabetes, persisting even after islet graft failure.
Biomimetic Hydroxyapatite Crystallization in Gelatin Nanoparticles Synthesized Using a Miniemulsion Process
Authors: Ethirajan Anitha , Ziener Ulrich , Chuvilin Andrey , Kaiser Ute , Cölfen Helmut , Landfester Katharina
Published: August 2008

Here, we report a novel biomimetic strategy to synthesize hydroxyapatite (HAP) inside of crosslinked gelatin nanoparticles, which serve as a nanoenvironment for crystal growth in the aqueous phase. The synthesis of gelatin nanoparticles with the inverse miniemulsion technique is very intriguing because of the flexibility offered by the technique in tailoring the properties of the gelatin nanoparticles. It can be shown that the nanoenvironment promotes a different growth environment for the crystal because of the confinement inside the particle. The formation of HAP inside the particles follows Ostwald's rule of stages. At first an amorphous phase is formed, which itself has a great potential to be used as a resorbable bone substitute. This further transforms into single crystalline HAP via an octacalcium phosphate intermediate. The solution‐mediated transformation into the HAP phase without any calcination step is studied in detail using transmission electron microscopy (TEM) and X‐ray diffraction (XRD) measurements.
Rhodium‐Catalyzed Oxidative Homocoupling of Boronic Acids
Authors: Vogler Thomas , Studer Armido
Published: August 2008

Oxidative homocoupling of aryl‐ and alkenylboronic acids was achieved with Wilkinson’s catalyst. Commercially available 2,2,6,6‐tetramethylpiperidine‐N‐oxyl radical (TEMPO) was used as a stoichiometric oxidant.
Autoimmune disease in a DFNA6/14/38 family carrying a novel missense mutation in WFS1
Authors: Hildebrand Michael S. , Sorensen Jessica L. , Jensen Maren , Kimberling William J. , Smith Richard J.H.
Published: August 2008

Most familial cases of autosomal dominant low frequency sensorineural hearing loss (LFSNHL) are attributable to mutations in the wolframin syndrome 1 (WFS1) gene at the DFNA6/14/38 locus. WFS1 mutations at this locus were first described in 2001 in six families segregating LFSNHL that was non‐progressive below 2,000 Hz; the causative mutations all clustered in the C‐terminal domain of the wolframin protein. Mutations in WFS1 also cause Wolfram syndrome (WS), an autosomal recessive neurodegenerative disorder defined by diabetes mellitus, optic atrophy and often deafness, while numerous single nucleotide polymorphisms (SNPs) in WFS1 have been associated with increased risk for diabetes mellitus, psychiatric illnesses and Parkinson disease. This study was conducted in an American family segregating autosomal dominant LFSNHL. Two hearing impaired family members also had autoimmune diseases—Graves disease (GD) and Crohn disease (CD). Based on the low frequency audioprofile, mutation screening of WFS1 was completed and a novel missense mutation (c.2576G → A) that results in an arginine‐to‐glutamine substitution (p.R859Q) was identified in the C‐terminal domain of the wolframin protein where most LFSNHL‐causing mutations cluster. The family member with GD also carried polymorphisms in WFS1 that have been associated with other autoimmune diseases. © 2008 Wiley‐Liss, Inc.
The electroencephalographic fingerprint of sleep is genetically determined: A twin study
Authors: De Gennaro Luigi , Marzano Cristina , Fratello Fabiana , Moroni Fabio , Pellicciari Maria Concetta , Ferlazzo Fabio , Costa Stefania , Couyoumdjian Alessandro , Curcio Giuseppe , Sforza Emilia , Malafosse Alain , Finelli Luca A. , Pasqualetti Patrizio , Ferrara Michele , Bertini Mario , Rossini Paolo Maria
Published: August 2008

Humans have an individual profile of the electroencephalographic power spectra at the 8 to 16Hz frequency during non–rapid eye movement sleep that is stable over time and resistant to experimental perturbations. We tested the hypothesis that this electroencephalographic “fingerprint” is genetically determined, by recording 40 monozygotic and dizygotic twins during baseline and recovery sleep after prolonged wakefulness. We show a largely greater similarity within monozygotic than dizygotic pairs, resulting in a heritability estimate of 96%, not influenced by sleep need and intensity. If replicated, these results will establish the electroencephalographic profile during sleep as one of the most heritable traits of humans. Ann Neurol 2008
Takotsubo cardiomyopathy in acute ischemic stroke
Authors: Yoshimura Sohei , Toyoda Kazunori , Ohara Tomoyuki , Nagasawa Hikaru , Ohtani Noriko , Kuwashiro Takahiro , Naritomi Hiroaki , Minematsu Kazuo
Published: August 2008

Objective

Takotsubo cardiomyopathy, which is characterized by transient left ventricular apical ballooning, is a known complication of subarachnoid hemorrhage. The aim of this study was to identify the clinical characteristics of acute ischemic stroke patients who experienced development of takotsubo cardiomyopathy.

Methods

Seven patients who were diagnosed as having takotsubo cardiomyopathy based on their electrocardiographic and echocardiographic findings were studied. They were selected from among 569 consecutive patients who were admitted to our stroke center within 24 hours after onset of acute ischemic stroke. The findings of nine previously published cases were also reviewed.

Results

All seven patients were women, and six were 75 years or older. The initial National Institutes of Health Stroke Scale score ranged from 3 to 28. The culprit infarcts included or were close to the insular cortex in six patients and were located extensively in the vertebrobasilar arterial territory in the other patient. Abnormal findings on electrocardiographic monitoring appeared within 10 hours after stroke onset in five patients and at 6 and 12 days, respectively, in the other two patients. The cardiomyopathy was symptomatic in only two patients. Plasma brain natriuretic peptide levels exceeded the upper normal limit by 10‐fold in all patients. The previously published cases were mostly women and had mainly vertebrobasilar stroke.

Interpretation

Takotsubo cardiomyopathy is not a rare complication of acute ischemic stroke. It most often occurred soon after stroke onset and was commonly asymptomatic. Female sex and insular damage were predominant features of the stroke patients who experienced development of takotsubo cardiomyopathy. Ann Neurol 2008
Will Rogers phenomenon in multiple sclerosis
Authors: Sormani Maria Pia , Tintorè Mar , Rovaris Marco , Rovira Alex , Vidal Xavier , Bruzzi Paolo , Filippi Massimo , Montalban Xavier
Published: August 2008

Objective

Using different criteria for classifying patients into various stages of a disease can modify the stage‐specific prognosis, even though the overall disease course remains unchanged. This is known as the “Will Rogers phenomenon,” precluding the use of historical controls for treatment trials. We assessed whether the Will Rogers phenomenon may affect multiple sclerosis (MS) prognosis when applying different diagnostic criteria.

Methods

Patients with a clinically isolated syndrome (CIS) suggestive of MS were studied. After 1 year, each patient was classified as CIS or evolved to MS according to two diagnostic criteria (Poser and McDonald). The outcome for prognosis was the time to reach an Expanded Disability Status Scale score ≥ 3.0.

Results

309 patients were studied for a median period of 84 months. After 1 year, 16% of patients had MS according to Poser and 44% according to McDonald criteria. The probability to reach Expanded Disability Status Scale score ≥ 3.0 at median follow‐up was 11% in CIS patients according to Poser and 7% according to McDonald criteria; it was 46% in MS patients according to Poser and 27% acccording to McDonald criteria. The group with a discordant diagnosis had a worse prognosis than that of CIS patients according to both criteria (p = 0.01), but better than that of MS patients according to both criteria (p = 0.01).

Interpretation

The use of different diagnostic criteria may generate spurious improvements in the medium‐term prognosis of MS. This calls for caution in using historical controls for MS trials. Ann Neurol 2008
Rolling‐Circle‐Amplifikation: Anwendungen in der Nanotechnologie und in der Biodetektion mit funktionellen Nucleinsäuren
Authors: Zhao Weian , Ali M. Monsur , Brook Michael A. , Li Yingfu
Published: August 2008

Die Rolling‐Circle‐Amplifikation (RCA) ist ein isothermer enzymatischer Prozess, der durch bestimmte DNA‐Polymerasen vermittelt wird. Bei der RCA werden lange einzelsträngige (ss) DNA‐Moleküle mithilfe eines einzelnen DNA‐Primers an einer kurzen ringförmigen ssDNA‐Matrize synthetisiert. Die RCA hat sich als eine Standardamplifikationsmethode für die ultraempfindliche DNA‐Detektion in der Genomik und Diagnostik bewährt. Neuerdings ist es gelungen, die RCA als Verfahren für die Erzeugung von DNA‐Matrizen im großen Maßstab nutzbar zu machen. Die so erzeugten Matrizen können zur Herstellung von periodischen Nanoanordnungen eingesetzt werden. Darüber hinaus wurden verschiedene RCA‐Strategien entwickelt, um repetitive Sequenzen von DNA‐Aptameren und DNAzymen herzustellen, die als Detektionsplattformen für kleine Moleküle und Proteine fungieren. Diese neuen Verfahren machen die RCA zu einer höchst vielseitigen Methode für die Vervielfältigung von DNA, die breite Anwendungsmöglichkeiten in der Genomik, Proteomik, Diagnostik, Biosensorik, Wirkstoffentwicklung und Nanotechnologie finden wird.
Rolling Circle Amplification: Applications in Nanotechnology and Biodetection with Functional Nucleic Acids
Authors: Zhao Weian , Ali M. Monsur , Brook Michael A. , Li Yingfu
Published: August 2008

Rolling circle amplification (RCA) is an isothermal, enzymatic process mediated by certain DNA polymerases in which long single‐stranded (ss) DNA molecules are synthesized on a short circular ssDNA template by using a single DNA primer. A method traditionally used for ultrasensitive DNA detection in areas of genomics and diagnostics, RCA has been used more recently to generate large‐scale DNA templates for the creation of periodic nanoassemblies. Various RCA strategies have also been developed for the production of repetitive sequences of DNA aptamers and DNAzymes as detection platforms for small molecules and proteins. In this way, RCA is rapidly becoming a highly versatile DNA amplification tool with wide‐ranging applications in genomics, proteomics, diagnosis, biosensing, drug discovery, and nanotechnology.
Mechanical and thermal properties of polypropylene/recycled polyethylene terephthalate/chopped rice husk composites
Authors: Ershad‐Langroudi Amir , Jafarzadeh‐Dogouri Fatemeh , Razavi‐Nouri Mohammad , Oromiehie Abdulrasoul
Published: August 2008

The various ratios of recycled polyethylene terephthalate (rPET) into polypropylene (PP) filled with 40 parts chopped rice husk per hundred part of polymer have been studied. Composites were prepared using a corotating twin screw extruder at temperature zones of 165–215, well below 250°C (rPET mp temperature) and characterized by mechanical and thermal properties. To improve the compatibility between different components, PP grafted with maleic anhydride was added as a coupling agent in all the compositions studied. The results showed that the addition of rPET improved the tensile and flexural modulus and impact strength of the composite while reducing its tensile and flexural strength. The scanning electron microscopy micrographs of samples in the injection direction showed that some particle shaped rPET inside the composites appear as drawn fibrils and some appear as plates. Differential scanning calorimetric studies showed that the addition of rPET particles to the composites decrease the PP crystallization temperatures. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Properties of lignocellulose tamarind fruit fibers
Authors: Maheswari C. Uma , Guduri B. R. , Rajulu A. Varada
Published: August 2008

Untreated and alkali‐treated fibers from tamarind fruits were analyzed with Fourier transform infrared, chemical, X‐ray, and thermogravimetric methods. The morphology of the fibers before and after the alkali treatment was studied with scanning electron microscopy. The tensile properties of these fibers before and after the alkali treatment were also studied. The Fourier transform infrared and chemical analyses indicated lowering of the hemicellulose content by the alkali treatment of the fibers. The tensile modulus increased with the alkali treatment. X‐ray diffraction revealed an increase in the crystallinity of the fibers with the alkali treatment. The thermal stability of the fibers increased slightly with the alkali treatment. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Investigating the spinnability in the dry‐jet wet spinning of PAN precursor fiber
Authors: Tan Lianjiang , Chen Huifang , Pan Ding , Pan Ning
Published: August 2008

The spinnability of a spinning solution using DMSO as the solvent was investigated for dry‐jet wet spinning of PAN precursor fiber. Among many variables responsible for spinnability, the coagulating conditions, the air gap length, the nonsolvent content in spinning solution, and the spinning temperature have been viewed as the key factors, and they were investigated in this study. It was found however, unlike in the wet spinning, the spinnability in dry‐jet wet spinning process was barely influenced by the coagulating conditions, likely attributable to the existence of the air gap. However, the spinnability worsened when the air gap was longer than 30 mm. The quality of the spinning solution deteriorated with the increasing water content in it. The spinnability improved when the spinning temperature was maintained between 60 and 72°C and turned down once the temperature was over 72°C. The experimental results indicated that all the factors should be comprehensively considered to ensure good spinnability in dry‐jet wet spinning process. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Influence of an annealing treatment on the solid‐state grafting of styrene onto spherical isotactic polypropylene granules
Authors: Deng Qing‐Tian , Fu Zhi‐Sheng , Sun Fang‐Li , Xu Jun‐Ting , Fan Zhi‐Qiang
Published: August 2008

The main place of solid‐state graft polymerization in polypropylene (PP) granules has been believed to be the amorphous region of PP. In this work, the solid‐phase morphology of nascent spherical PP (N‐PP) granules was found to be markedly changed by an annealing treatment. The crystallinity of PP granules was almost doubled after annealing at 150°C for 12 h, whereas the porosity of the granules was unchanged. Solid‐state grafting polymerizations of styrene initiated by tert‐butyl perbenzoate in both N‐PP and annealed polypropylene (A‐PP) granules were compared under different reaction conditions. The formation of gel in the product could be completely depressed at a low concentration of the initiator when A‐PP granules were used as the matrix and graft‐polymerized at 120°C. Both the introduction of styrene and the annealing treatment of the PP granules led to a depression of polymer degradation in the process of the grafting reaction. However, using A‐PP as the matrix caused an increase in the grafting degree at a relatively high concentration of the initiator. A reduction in the amorphous phase in the PP granules was thought to be the main reason for the effects of the annealing treatment on the structure of the graft polymerization products. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Investigation of dispersion states and rheological properties of SPI in the DMSO/urea
Authors: Xiao Ru , Yin Duan , Gu Lixia
Published: August 2008

Dimethylsulfoxide (DMSO)/urea were chosen as a hybrid solvent system to dissolve soy protein. The dispersion status and rheological properties of soy protein isolates (SPI) in the DMSO/urea were studied. The result showed that SPI has relatively high solubility in DMSO/urea blend system and urea served as a key factor of dissolving SPI in the system. SPI in the DMSO/urea hybrid system exhibited different dispersion statuses with increasing of SPI content. The SPI dispersions in the DMSO/urea presented shear thinning or pseudoplastic behavior. The pseudoplastic behavior, the degree of non‐Newtonian flow and the extent of structuralization of SPI dispersion system with increasing SPI content were discussed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.
Isothermal oxidation kinetics of unstabilized polypropylene in the molten state
Authors: Sarrabi S. , Colin X. , Tcharkhtchi A.
Published: August 2008

This article is devoted to the elaboration of a nonempirical kinetic model for the thermal oxidation of molten unstabilized polypropylene (PP), which occurs typically at 170–250°C, a current temperature range for PP processing. The validity of the kinetic model has been successfully checked with the kinetic curves of mass changes and ketone group buildup of quasihomogeneously oxidized PP films (≈40 μm thick) at 190, 200, and 230°C in atmospheric air. The orders of magnitude of the model parameters, determined with the kinetic model as an inverse method, are physically reasonable. Large differences obtained between some rate constant values determined in this study for PP and published elsewhere for polyethylene are tentatively explained. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and study of the oligo(ether–ester)s based on butylene oxide
Authors: Ahmetli Gulnare , Kocak Ahmet , Soydal Ulku
Published: August 2008

Unsaturated oligo(ether–ester) was prepared by ring‐opening polymerization of butylene oxide (BO) with glycidyl methacrylate (GMA) in the presence of cationic catalyst BF3•O(C2H5)2. The effects of mol ratio of the initial components, amount of catalyst, temperature, and reaction times on the copolymerization reaction were examined. Oligo(ether–ester) were achieved in highest yield of 82% after reaction times of 4 h at 0°C. Synthesized copolymer was characterized using spectroscopic (1H NMR and IR) and chemical analysis methods. The thermal degradation and softing points of oligo(ether–ester)‐styrene composites were studied. It is shown that crosslinking of the unsaturated oligo(ether–ester) with styrene takes place through the use of thermostable materials. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008.
Preparation and characterization of a novel series of amphiphilic phospholipids compounds
Authors: Yu Hui , Gu Xiaohua , Qi Xuelian , Chen Xiaoyan , Shen Xinyuan , Duan Yourong
Published: August 2008

For application of phospholipids compounds in drug permeation field, a novel series of amphiphilic phospholipids compounds containing different aliphatic chains as the hydrophobic tail groups and phosphorylcholine as the hydrophilic head groups were synthesized in three steps: preparation of hydroxyalkyl methacrylate by the reaction of various aliphatic chain diols with α‐methacryloyl chloride; preparation of 2‐(2‐oxo‐1,3,2‐dioxaphospholoyloxy)alkyl methacrylate by the reaction of hydroxyalkyl methacrylate with 2‐chloro‐2‐oxo‐1,3,2‐dioxaphospholane; preparation of the amphiphilic phospholipids compounds by the ring‐opening reaction of 2‐(2‐oxo‐1,3,2‐dioxaphospholoyloxy)alkyl methacrylate in the presence of trimethylamine. The chemical structure of the amphiphilic phospholipids compounds were supported by Fourier transform infrared spectroscopy and 1H NMR. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Behavior of flexible poly(vinyl chloride)/poly(hydroxybutyrate valerate) blends
Authors: Marcilla A. , Garcia‐Quesada J. C. , Gil E.
Published: August 2008

Blends of flexible poly(vinyl chloride) (PVC) and a poly(hydroxybutyrate valerate) (PHBV) copolymer were prepared and characterized with different techniques. The tensile strength of PVC did not show a marked reduction at PHBV concentrations up to 50 phr, despite a lack of miscibility between the two polymers. The crystallization of the PHBV copolymer was markedly hindered by the presence of PVC, as calorimetric results revealed. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Organic‐acid‐catalyzed sol–gel route for preparing poly(methyl methacrylate)–silica hybrid materials
Authors: Yeh Jui‐Ming , Huang Kuan‐Yeh , Dai Chung‐Feng , Chand B. G. , Weng Chang‐Jian
Published: August 2008

In this study, a series of organic–inorganic hybrid sol–gel materials consisting of a poly(methyl methacrylate) (PMMA) matrix and dispersed silica (SiO2) particles were successfully prepared through an organic‐acid‐catalyzed sol–gel route with N‐methyl‐2‐pyrrolidone as the mixing solvent. The as‐synthesized PMMA–SiO2 nanocomposites were subsequently characterized with Fourier transform infrared spectroscopy and transmission electron microscopy. The solid phase of organic camphor sulfonic acid was employed to catalyze the hydrolysis and condensation (i.e., sol–gel reactions) of tetraethyl orthosilicate in the PMMA matrix. The formation of the hybrid membranes was beneficial for the physical properties at low SiO2 loadings, especially for enhanced mechanical strength and gas barrier properties, in comparison with the neat PMMA. The effects of material composition on the thermal stability, thermal conductivity, mechanical strength, molecular permeability, optical clarity, and surface morphology of the as‐prepared hybrid PMMA–SiO2 nanocomposites in the form of membranes were investigated with thermogravimetric analysis, differential scanning calorimetry, dynamic mechanical analysis, gas permeability analysis, ultraviolet–visible transmission spectroscopy, and atomic force microscopy, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Effects of interfacial modification on the thermal, mechanical, and fire properties of high‐impact polystyrene/microencapsulated red phosphorous
Authors: Chang Suqin , Xie Tingxiu , Yang Guisheng
Published: August 2008

In this study, polystyrene (PS)‐encapsulated magnesium hydroxide‐microencapsulated red phosphorus (MHRP) was prepared by in situ polymerization of styrene on the surface of MHRP in a high speed mixer. The encapsulated MHRP flame retardant was successfully applied in the fire resistance to HIPS by melt blending in a corotating twin‐screw extruder. The effects of PS‐encapsulated MHRP on the properties of HIPS composites were studied by mechanical, thermal, and combustion tests (HBR, LOI, UL‐94, and cone calorimetry). The experimental results showed that compared to the composites containing untreated MHRP, the thermal, mechanical, and flame‐ retardant properties of those containing PS‐encapsulated MHRP were found to be prominently improved. This improvement was mostly attributed to an effective dispersion of the encapsulated filler and a good interfacial compatibility between the filler and the matrix. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Ionic polymer‐metal composites made from radiation grafted FEP‐g‐styrene‐SO3H membranes
Authors: Rao S. S. , Ojha P. K. , Rath S. K. , Palla K. B. , Patri M.
Published: August 2008

Ionic polymer‐metal composites have been made from radiation grafted fluorinated ethylene propylene (FEP) membranes. Membranes have been synthesized by grafting of styrene on FEP films followed by sulfonation. These membranes were then used to fabricate IPMCs. Chemical plating of silver has been done to form the microelectrodes. Influence of degree of grafting on actuation, surface resistance, and tensile properties of the IPMC have been evaluated. It has been observed that on increasing the degree of grafting surface resistance, tensile strength, and elongation of IPMC decrease while degree of actuation and modulus increase. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Magnetic and electrical resistivity tomography investigations in a Roman legionary camp site (Legio IV Scythica) in Zeugma, Southeastern Anatolia, Turkey
Authors: Drahor M. G. , Berge M. A. , Kurtulmuş T. Ö. , Hartmann M. , Speidel M. A.
Published: August 2008

Magnetic and electrical resistivity tomography (ERT) surveys were carried out in the area of a Roman military installation located near the Zeugma archaeological site in southeastern Turkey. Magnetic gradiometer surveys were performed in the northern part of this area and covered 8.52 ha; measurements were obtained using a FM‐36 fluxgate gradiometer on a 0.5 × 1 m grid. The visualized data revealed the general orientation of the Roman military settlement, which appeared as regular structures in the magnetic images. In addition, ERT surveys were performed in some areas that had shown regular magnetic anomalies. Resistivity data were interpreted using the robust inversion algorithm in two‐dimensional and three‐dimensional forms. Resistivity tomography studies showed that the archaeological structures lay close to the surface. There was considerable agreement between the results of the magnetic and ERT survey methods. Trial trenches were excavated in promising areas to test the geophysical results. A range of distinctive elements of military settlement, such as walls, pipes, roads, foundations and also metallic objects (a large assemblage of Roman military helmets and armour) were discovered during the excavations. Copyright © 2008 John Wiley & Sons, Ltd.
Auf der Suche nach dem großen Knall. Massensterben von Dinosauriern & Co. am Ende der Kreidezeit
Authors: Stinnesbeck Wolfgang
Published: August 2008

Am Ende der Kreidezeit ereignete sich ein weltweites, massives Artensterben, dem die Dinosaurier, die Ammoniten und ein Großteil des marinen Planktons zum Opfer fielen. Nach einer gängigen Hypothese soll der Einschlag eines Asteroiden die Ursache gewesen sein. Die Einschlagstelle wird in der Nähe des Dorfes Chicxulub auf der Halbinsel Yucatan in Mexiko vermutet. Bei genauerer Untersuchung stellt sich heraus, dass die Gründe für das Massensterben wesentlich komplexer waren: Vermutlich kam es zu einer Verknüpfung mehrerer zeitlich getrennter Ereignisse und Faktoren. Neben intensivem Vulkanismus und den daraus resultierenden Schwankungen des Klimas und des Meeresspiegels war auch eine Serie von Asteroiden‐Einschlägen beteiligt. Der Yucatan‐Einschlag ist aber bis zu 300.000 Jahre älter als die Kreide/Tertiär‐Grenze und damit nicht der Auslöser des globalen Artensterbens.
Orchideen, Wespen, Raupen: Mimikry eines Hilferufes
Authors: Brennicke Axel
Published: August 2008

Bereits Darwin hatte bemerkt, dass einige Orchideen ganz bestimmte Wespen anlocken, konnte aber nicht erklären, wie. Neue Ergebnisse zeigen, dass die Blüten ein ganz besonderes chemisches Bukett abgeben: Sie duften wie von Raupen angefressene Blätter. Mit diesen Verbindungen locken die attackierten Pflanzen Wespen an, damit diese die Raupen fressen.
Nachrichten des Verbandes Biologie, Biowissenschaften & Biomedizin in Deutschland
Authors: Wittinghofer Alfred
Published: August 2008

Bundesdelegiertenkonferenz: Was treibt den VBIO ein Jahr nach der Fusion um?

Aus den VBIO‐Arbeitskreisen: AK Biomedizin

Fachsektion Didaktik: Trauer um Prof. Dr. H. Vogt

Wissenschaft und Gesellschaft: Das Umweltgesetzbuch

Ehrungen: Treviranus‐Medaille für Prof. Dr. Günter Tembrock

Termine
Albrecht von Haller
Authors: Irsch Wilhelm
Published: August 2008

Am 16. Oktober 2008 feiert man nicht nur in der Schweiz den 300. Geburtstag Albrecht von Hallers (1708–1777). Der Universalgelehrte zählte zu den wichtigsten Persönlichkeiten des Jahrhunderts der Aufklärung. Seine Leistungen als Begründer der experimentellen Physiologie, Erforscher der Schweizer Flora und Dichter der Alpen wiesen der Medizin, Botanik und Literatur neue Wege.
Describing, diagnosing, and naming psychopathy: how do youth psychopathy labels influence jurors?
Authors: Boccaccini Marcus T. , Murrie Daniel C. , Clark John W. , Cornell Dewey G.
Published: August 2008

Previous studies have reached opposing conclusions regarding how psychopathy assessment influences the court's response to a juvenile defendant. This study sought to clarify the apparent discrepancies across studies by distinguishing among three key variables: history of antisocial behavior (substantial versus minimal), psychopathic personality traits (present versus absent), and diagnostic label (no diagnosis, conduct disorder, psychopathy, or “is a psychopath”). We systematically manipulated these variables in vignettes describing expert testimony, and then distributed these vignettes to 891 jury‐pool members. Descriptions of the antisocial behavior and psychopathic personality traits underlying diagnoses tended to have stronger effects than did the diagnostic labels (i.e. psychopathy or conduct disorder). However, labeling juvenile defendants with the colloquial term “psychopath” led jurors to believe that they posed greater risk for future crime and deserved greater punishment compared with juveniles described as meeting diagnostic criteria for psychopathy or conduct disorder. Results should influence the language forensic evaluators use in practice. Results should also inform research that investigates diagnostic labeling effects. Copyright © 2008 John Wiley & Sons, Ltd.
COD services in community correctional settings: An examination of organizational factors that affect service delivery
Authors: Taxman Faye S. , Cropsey Karen L. , Melnick Gerald , Perdoni Matthew L.
Published: August 2008

Little is known about service delivery for those in the correctional system with co‐occurring mental health and substance abuse disorders (COD). Using data from the National Criminal Justice Treatment Practices survey (NCJTP) on community corrections and jail agencies, this study found that correctional organizations that offer COD services differ from agencies that do not. Organizations that respond to the needs of COD offenders tend to be more “service friendly,” rank higher on measures of various dimensions of organizational climate that embrace learning and goal achievement, and tend to adopt more innovations, particularly those classified as evidence‐based practices. These survey findings indicate that correctional agencies who serve COD offenders are in a better position to be responsive to the changing service needs of the populations, and are more likely to be able to balance public safety and treatment goals. Future steps to develop support environments for COD assessment and treatment services are discussed in light of these findings. Copyright © 2008 John Wiley & Sons, Ltd.