bluuebunny/crossref_metadata_2025 huggingface dataset:
Stratigraphic and structural evolution of the Blue Nile Basin, Northwestern Ethiopian Plateau
Authors: Gani N. DS. , Abdelsalam M. G. , Gera S. , Gani M. R.
Published: September 2008

The Blue Nile Basin, situated in the Northwestern Ethiopian Plateau, contains ∼1400 m thick Mesozoic sedimentary section underlain by Neoproterozoic basement rocks and overlain by Early–Late Oligocene and Quaternary volcanic rocks. This study outlines the stratigraphic and structural evolution of the Blue Nile Basin based on field and remote sensing studies along the Gorge of the Nile. The Blue Nile Basin has evolved in three main phases: (1) pre‐sedimentation phase, include pre‐rift peneplanation of the Neoproterozoic basement rocks, possibly during Palaeozoic time; (2) sedimentation phase from Triassic to Early Cretaceous, including: (a) Triassic–Early Jurassic fluvial sedimentation (Lower Sandstone, ∼300 m thick); (b) Early Jurassic marine transgression (glauconitic sandy mudstone, ∼30 m thick); (c) Early–Middle Jurassic deepening of the basin (Lower Limestone, ∼450 m thick); (d) desiccation of the basin and deposition of Early–Middle Jurassic gypsum; (e) Middle–Late Jurassic marine transgression (Upper Limestone, ∼400 m thick); (f) Late Jurassic–Early Cretaceous basin‐uplift and marine regression (alluvial/fluvial Upper Sandstone, ∼280 m thick); (3) the post‐sedimentation phase, including Early–Late Oligocene eruption of 500–2000 m thick Lower volcanic rocks, related to the Afar Mantle Plume and emplacement of ∼300 m thick Quaternary Upper volcanic rocks. The Mesozoic to Cenozoic units were deposited during extension attributed to Triassic–Cretaceous NE–SW‐directed extension related to the Mesozoic rifting of Gondwana. The Blue Nile Basin was formed as a NW‐trending rift, within which much of the Mesozoic clastic and marine sediments were deposited. This was followed by Late Miocene NW–SE‐directed extension related to the Main Ethiopian Rift that formed NE‐trending faults, affecting Lower volcanic rocks and the upper part of the Mesozoic section. The region was subsequently affected by Quaternary E–W and NNE–SSW‐directed extensions related to oblique opening of the Main Ethiopian Rift and development of E‐trending transverse faults, as well as NE–SW‐directed extension in southern Afar (related to northeastward separation of the Arabian Plate from the African Plate) and E–W‐directed extensions in western Afar (related to the stepping of the Red Sea axis into Afar). These Quaternary stress regimes resulted in the development of N‐, ESE‐ and NW‐trending extensional structures within the Blue Nile Basin. Copyright © 2008 John Wiley & Sons, Ltd.
Undiagnosed sleep‐related breathing disorders are associated with focal brainstem atrophy in the elderly
Authors: Celle Sébastien , Peyron Roland , Faillenot Isabelle , Pichot Vincent , Alabdullah Majed , Gaspoz Jean‐Michel , Laurent Bernard , Barthélémy Jean‐Claude , Roche Frédéric
Published: September 2008

Background: Sleep‐related breathing disorders (SRBDs) affect as many as 40% of elderly people. The association of SRBDs with structural brain abnormalities remains unclear. In this observational study, we evaluated gray matter changes in the brain associated with sleep abnormalities in volunteers and their relationship with the severity of SRBDs. Methods: One hundred fifty two healthy subjects aged 66.0 ± 0.6 years‐old underwent tridimensional brain MRI and nocturnal polygraphic recording during which apnea/hypopnea index (AHI) and the oxyhemoglobin desaturation index (ODI) were measured. Using voxel‐based morphometry, we investigated the presence of gray matter abnormalities in association with AHI and ODI. Findings: Seventy‐six subjects (50%) had SRBDs defined by an AHI ≥ to 15 and 25 subjects (16%) SRBDs defined by an ODI ≥ 15, in the absence of systematic excessive daytime sleepiness. A significant symmetrical loss of gray matter in the intermediate reticular zone of the bulbopontine area was found to correlate with both AHI and ODI (P < 0.05 corrected for multiple comparisons for cluster significance). Interpretation: This gray matter volume decrease in brain regions involved in breathing/autonomic functions, as well as their correlation with the severity of the disorder, suggests a pathophysiological link between structural changes and SRBDs. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Regional networks underlying interhemispheric connectivity: An EEG and DTI study in healthy ageing and amnestic mild cognitive impairment
Authors: Teipel Stefan J. , Pogarell Oliver , Meindl Thomas , Dietrich Olaf , Sydykova Djyldyz , Hunklinger Ulrike , Georgii Bea , Mulert Christoph , Reiser Maximilian F. , Möller Hans‐Jürgen , Hampel Harald
Published: September 2008

Interhemispheric coherence derived from electroencephalogram (EEG) recordings is a measure of functional interhemispheric connectivity. Diffusion tensor imaging (DTI) determines the integrity of subcortical fiber tracts. We studied the pattern of subcortical fiber tracts underlying interhemispheric coherence and its alteration in 16 subjects with amnestic mild cognitive impairment (MCI), an at risk syndrome for Alzheimer's disease, and 20 cognitively healthy elderly control subjects using resting state EEG and high resolution DTI at 3 T. We used a multivariate network approach based on principal component analysis to determine effects of coherence on the regional pattern of diffusivity. Temporo‐parietal coherence in the α band was significantly correlated with diffusivity in predominantly posterior white matter tracts including posterior corpus callosum, parietal, temporal and occipital lobe white matter, thalamus, midbrain, pons, and cerebellum, both in MCI subjects and controls (P < 0.05). In MCI subjects, frontal coherence in the α band was significantly correlated with a predominately frontal pattern of diffusivity including fiber tracts of the anterior corpus callosum, frontal lobe white matter, thalamus, pons, and cerebellum (P < 0.05). The study provides a methodology to access specific networks of subcortical fiber tracts subserving the maintenance of interhemispheric resting state coherence in the human brain. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Instinctive modulation of cognitive behavior: A human evoked potential study
Authors: Nahum Louis , Morand Stéphanie , Barcellona‐Lehmann Sandra , Schnider Armin
Published: September 2008

Successful adaptive behavior requires fast information processing. Behavioral switches may be necessary in response to threatening stimuli or when anticipated outcomes fail to occur. In this study, we explored the cortical processing of these two components using high‐resolution evoked potentials. Subjects made a reversal learning task where they had to predict which one of two faces had a target stimulus on the nose. We found early electrocortical differences at 100–200 ms depending on whether the target stimulus was a spider or a disk. Source estimation indicated that this distinction was mediated by an anterior medial temporal region including the amygdala and adjacent cortex. When a switch to the alternate face was required, there was a discrete early electrocortical correlate after 200 ms, mediated by ventromedial prefrontal areas. Continued validity of stimulus‐target associations was signaled at 400–520 ms, mediated by the parahippocampal region. The study indicates rapid serial processing of innate emotional quality, then cognitive‐behavioral relevance of stimuli, mediated by limbic and paralimbic structures. Hum Brain Mapp, 2009. © 2008 Wiley‐Liss, Inc.
Characterization of a glycine N‐methyltransferase gene knockout mouse model for hepatocellular carcinoma: Implications of the gender disparity in liver cancer susceptibility
Authors: Liao Yi‐Jen , Liu Shih‐Ping , Lee Cheng‐Ming , Yen Chia‐Hung , Chuang Pei‐Chun , Chen Chia‐Yen , Tsai Ting‐Fen , Huang Shiu‐Feng , Lee Yan‐Hwa Wu , Chen Yi‐Ming Arthur
Published: September 2008

Hepatocellular carcinoma (HCC) is the fifth common cancer in the world and it mainly occurs in men. Glycine N‐methyltransferase (GNMT) participates in one‐carbon metabolism and affects DNA methylation by regulating the ratio of S‐adenosylmethionine to S‐adenosylhomocystine. Previously, we described that the expression of GNMT was diminished in human HCC. Here, we showed that 50% (3/6) male and 100% (7/7) female Gnmt−/− mice developed HCC, and their mean ages of HCC development were 17 and 16.5 months, respectively. In addition, 42.9% (3/7) of female Gnmt−/− mice had hemangioma. Wnt reporter assay demonstrated that Gnmt is a negative regulator for canonical Wnt signaling pathway. Beta‐catenin, cyclin D1 and c‐Myc, genes related to Wnt pathway, were upregulated in the liver tissues from both 11 weeks and HCC stage of Gnmt−/− mice. Furthermore, global DNA hypomethylation and aberrant expression of DNA methyltransferases 1 and 3b were found in the early and late stages of HCC development. Hierarchical cluster analysis of 6,023 transcripts from microarray data found that gene expression patterns of HCC tumors from male and female Gnmt−/− mice were distinctively different. Real‐time PCR confirmed that Gadd45a, Pak1, Mapk3 and Dsup3 genes of mitogen‐activated protein kinase (MAPK) pathway were activated in Gnmt−/− mice, especially in the female mice. Therefore, GNMT is a tumor suppressor gene for liver cancer, and it is associated with gender disparity in liver cancer susceptibility. © 2008 Wiley‐Liss, Inc.
Evaluation of molecular forms of prostate‐specific antigen and human kallikrein 2 in predicting biochemical failure after radical prostatectomy
Authors: Wenske Sven , Korets Ruslan , Cronin Angel M. , Vickers Andrew J. , Fleisher Martin , Scher Howard I. , Pettersson Kim , Guillonneau Bertrand , Scardino Peter T. , Eastham James A. , Lilja Hans
Published: September 2008

Most pretreatment risk‐assessment models to predict biochemical recurrence (BCR) after radical prostatectomy (RP) for prostate cancer rely on total prostate‐specific antigen (PSA), clinical stage, and biopsy Gleason grade. We investigated whether free PSA (fPSA) and human glandular kallikrein‐2 (hK2) would enhance the predictive accuracy of this standard model. Preoperative serum samples and complete clinical data were available for 1,356 patients who underwent RP for localized prostate cancer from 1993 to 2005. A case‐control design was used, and conditional logistic regression models were used to evaluate the association between preoperative predictors and BCR after RP. We constructed multivariable models with fPSA and hK2 as additional preoperative predictors to the base model. Predictive accuracy was assessed with the area under the ROC curve (AUC). There were 146 BCR cases; the median follow up for patients without BCR was 3.2 years. Overall, 436 controls were matched to 146 BCR cases. The AUC of the base model was 0.786 in the entire cohort; adding fPSA and hK2 to this model enhanced the AUC to 0.798 (p= 0.053), an effect largely driven by fPSA. In the subgroup of men with total PSA ≤10 ng/ml (48% of cases), adding fPSA and hK2 enhanced the AUC of the base model to a similar degree (from 0.720 to 0.726,p= 0.2). fPSA is routinely measured during prostate cancer detection. We suggest that the role of fPSA in aiding preoperative prediction should be investigated in further cohorts. © 2008 Wiley‐Liss, Inc.
Imbalance of DNA‐dependent protein kinase subunits in polycythemia vera peripheral blood stem cells
Authors: Siebolts Udo , Breuhahn Kai , Hennecke Andrea , Schultze Joachim L. , Wickenhauser Claudia
Published: September 2008

Polycythemia vera (PV) is a clonal hematopoietic stem cell disease characterized by a trilinear accumulation of blood cells that has been recently associated with a JAK2V617F point mutation. However, this molecular defect represents a rather late event in the disease progression, is not specific for this disease, and is not ascertained in all patients indicating that additional factors contribute to the specific phenotype of PV. Therefore, cDNA microarray analyses were performed on CD34+ peripheral blood stem cells (PBSC) with subsequent evaluation on mRNA and protein level of a larger cohort of PV patients. Microarray analyses revealed a significant dysregulation of 11 genes. KU86, a gene coding for a subunit of the DNA‐dependent protein kinase (DNA‐PK), displayed the strongest upregulation in all patients under study. This peculiarity was accompanied by downregulation of the catalytic DNA‐PK subunit DNA‐PKcs. Also Ku86 protein was upregulated and expressed in the vast majority of CD34+ PBSC nuclei while a weak nuclear expression was detected in only one blood donor. Differential expression of several genes, imbalance of the distinct subunits of DNA‐PK, and particularly the strong upregulation of Ku86 protein, are new findings in PV CD34+ PBSC. These factors may contribute to the accumulation of chromosomal aberrations, accumulation of hematopoietic cells (especially of erythropoiesis), and prolongation of CD34+ PBSC life span observed in PV. © 2008 Wiley‐Liss, Inc.
Cure of established GL261 mouse gliomas after combined immunotherapy with GM‐CSF and IFNγ is mediated by both CD8+ and CD4+ T‐cells
Authors: Smith Karin Enell , Fritzell Sara , Badn Wiaam , Eberstål Sofia , Janelidze Shorena , Visse Edward , Darabi Anna , Siesjö Peter
Published: September 2008

We were the first to demonstrate that combined immunotherapy with GM‐CSF producing GL261 cells and recombinant IFNγ of preestablished GL261 gliomas could cure 90% of immunized mice. To extend these findings and to uncover the underlying mechanisms, the ensuing experiments were undertaken. We hypothesized that immunizations combining both GM‐CSF and IFNγ systemically would increase the number of immature myeloid cells, which then would mature and differentiate into dendritic cells (DCs) and macrophages, thereby augmenting tumor antigen presentation and T‐cell activation. Indeed, the combined therapy induced a systemic increase of both immature and mature myeloid cells but also an increase in T regulatory cells (T‐regs). Cytotoxic anti‐tumor responses, mirrored by an increase in Granzyme B‐positive cells as well as IFNγ‐producing T‐cells, were augmented after immunizations with GM‐CSF and IFNγ. We also show that the combined therapy induced a long‐term memory with rejection of intracerebral (i.c.) rechallenges. Depletion of T‐cells showed that both CD4+ and CD8+ T‐cells were essential for the combined GM‐CSF and IFNγ effect. Finally, when immunizations were delayed until day 5 after tumor inoculation, only mice receiving immunotherapy with both GM‐CSF and IFNγ survived. We conclude that the addition of recombinant IFNγ to immunizations with GM‐CSF producing tumor cells increased the number of activated tumoricidal T‐cells, which could eradicate established intracerebral tumors. These results clearly demonstrate that the combination of cytokines in immunotherapy of brain tumors have synergistic effects that have implications for clinical immunotherapy of human malignant brain tumors. © 2008 Wiley‐Liss, Inc.
Causes of death among Belgian professional military radar operators: A 37‐year retrospective cohort study
Authors: Degrave Etienne , Meeusen Ben , Grivegnée André‐Robert , Boniol Mathieu , Autier Philippe
Published: September 2008

Concerns have been raised about the safety of the electromagnetic (microwave) emissions of radars, as well as about the ionizing radiation that is emitted on short distances (<2 m) by devices in the radars producing the microwaves. We retrospectively compared the cause specific mortality of 4,417 Belgian professional male military personnel who served in anti‐aircraft radar units in Germany between 1963 and 1994 to the cause specific mortality of 2,932 Belgian military personnel who served at the same time in the same place in battalions not equipped with radars. Mean follow‐up was 26 years in the 2 groups. Age‐adjusted rate ratio (RR) and 95% confidence intervals were derived from a Poisson regression model. Four hundred twenty‐four deaths in the battalions groups and 271 deaths in the control battalions occurred (RR = 1.04 (0.96–1.14)). For specific causes of deaths, RRs were 1.22 (1.03–1.47) for neoplasms and 3.51 (1.19–10.3) for symptoms, signs and ill defined conditions. RRs for other causes of death were not significantly different from 1.00. Among deaths from neoplasms, RR for hemolymphatic cancer was 7.22 (1.09–47.9). RRs for other causes of cancer deaths were not significantly different from 1.00. The results for specific tumor types were all based on very small numbers. The RR for cancer increased with decreasing age and suggested that the RR for cancer increased with the duration of stay in radar battalions. In conclusion, exposure of professional military personnel to anti‐aircraft radars that existed in Western Europe from the 1960s until the 1990s may have resulted in an increase in the incidence of hemolymphatic cancers. It remains to be established whether this increase is due to microwaves generated by radars or ionizing radiation produced by electronic devices producing the microwaves. © 2008 Wiley‐Liss, Inc.
Longitudinal association of anthropometry with mammographic breast density in the Study of Women's Health Across the Nation
Authors: Reeves Katherine W. , Stone Roslyn A. , Modugno Francesmary , Ness Roberta B. , Vogel Victor G. , Weissfeld Joel L. , Habel Laurel A. , Sternfeld Barbara , Cauley Jane A.
Published: September 2008

High percent mammographic breast density is strongly associated with increased breast cancer risk. Though body mass index (BMI) is positively associated with risk of postmenopausal breast cancer, BMI is negatively associated with percent breast density in cross‐sectional studies. Few longitudinal studies have evaluated associations between BMI and weight and mammographic breast density. We studied the longitudinal relationships between anthropometry and breast density in a prospective cohort of 834 pre‐ and perimenopausal women enrolled in an ancillary study to the Study of Women's Health Across the Nation (SWAN). Routine screening mammograms were collected and read for breast density. Random intercept regression models were used to evaluate whether annual BMI change was associated with changes over time in dense breast area and percent density. The study population was 7.4% African‐American, 48.8% Caucasian, 21.8% Chinese, and 21.9% Japanese. Mean follow‐up was 4.8 years. Mean annual weight change was +0.32 kg/year, mean change in dense area was −0.77 cm2/year, and mean change in percent density was ‐1.14%/year. In fully adjusted models, annual change in BMI was not significantly associated with changes in dense breast area (−0.17 cm2, 95% CI −0.64, 0.29). Borderline significant negative associations were observed between annual BMI change and annual percent density change, with percent density decreasing 0.36% (95% CI −0.74, 0.02) for a one unit increase in BMI over a year. This longitudinal study provides modest evidence that changes in BMI are not associated with changes in dense area, yet may be negatively associated with percent density. © 2008 Wiley‐Liss, Inc.
The mechanism of chemical delivery to the vomeronasal organs in squamate reptiles: a comparative morphological approach
Authors: Filoramo Nirvana I. , Schwenk Kurt
Published: September 2008

Vomeronasal chemoreception, an important chemical sense in squamate reptiles (lizards and snakes), is mediated by paired vomeronasal organs (VNOs), which are only accessible via ducts opening through the palate anteriorly. We comparatively examined the morphology of the oral cavity in lizards with unforked tongues to elucidate the mechanism of stage I delivery (transport of chemical‐laden fluid from the tongue tips to the VNO fenestrae) and to test the generality of the Gillingham and Clark (1981. Can J Zool 59:1651–1657) hypothesis (based on derived snakes), which suggests that the sublingual plicae act as the direct conveyors of chemicals to the VNOs. At rest, the foretongue lies within a chamber formed by the sublingual plicae ventrally and the palate dorsally, with little or no space around the anterior foretongue when the mouth is closed. There is a remarkable conformity between the shape of this chamber and the shape of the foretongue. We propose a hydraulic mechanism for stage I chemical transport in squamates: during mouth closure, the compliant tongue is compressed within this cavity and the floor of the mouth is elevated, expressing fluid from the sublingual glands within the plicae. Chemical‐laden fluid covering the tongue tips is forced dorsally and posteriorly toward the VNO fenestrae. In effect, the tongue acts as a piston, pressurizing the fluid surrounding the foretongue so that chemical transport to the VNO ducts is effected almost instantaneously. Our findings falsify the Gillingham and Clark (1981. Can J Zool 59:1651–1657) hypothesis for lizards lacking forked, retractile tongues. J. Exp. Zool. 311A:20–34, 2009. © 2008 Wiley‐Liss, Inc.
Shape and size variation: Growth and development of the dusky grouper (Epinephelus marginatus Lowe, 1834)
Authors: Russo Tommaso , Pulcini Domitilla , Bruner Emiliano , Cataudella Stefano
Published: September 2008

Demersal fishes have complex life cycles that involve an ontogenetic change in morphology, physiology, and behavior, as their pelagic larval stages colonize benthic habitats. The developmental transition between larvae and juveniles leads to very complex processes of morphogenesis and differentiation. These processes primarily determine changes in external morphology, which is shaped by selective pressures to optimize performance for basic activities such as swimming, escape from predators, and feeding. Fishes have provided fertile grounds for ecomorphological investigations throughout ontogeny, as the role of changing morphology in inducing ontogenetic niche shifts is not always clear. In this framework, some studies have demonstrated that certain species undergo gradual changes, whereas other species experience threshold effects in their ecomorphological relationships during ontogeny. In this study, the intraspecific allometry of the dusky grouper was examined. Geometric morphometric tools were used to quantify shape changes through the development, and a modular approach was also applied to analyze the pattern of covariation between three distinct blocks (head, trunk, and tail). For this purpose, a two‐block Partial Least Square was computed. This method reveals that the pattern of changes in the overall body shape is the result of the modularized changes of these blocks. J. Morphol., 2009. © 2008 Wiley‐Liss, Inc.
Regulation of brain‐derived neurotrophic factor‐mediated transcription of the immediate early gene Arc by intracellular calcium and calmodulin
Authors: Zheng Fei , Luo Yongneng , Wang Hongbing
Published: September 2008

The induction of the immediate early gene Arc is strongly implicated in synaptic plasticity. Although the role of ERK has been demonstrated, the regulation of Arc expression is largely unknown. In this study, we investigated the major signaling pathways underlying brain‐derived neurotrophic factor (BDNF)‐mediated Arc transcription in cultured cortical neurons. The BDNF‐stimulated Arc transcription was regulated solely by the Ras‐Raf‐MAPK signaling through ERK, but not by phosphoinositide 3‐kinase (PI3K) and PLC‐γ activities. Although it was demonstrated that BDNF might promote calcium entry through calcium channels and NMDA receptors, chelating extracellular calcium with EGTA failed to block Arc transcription. In contrast, chelating intracellular calcium ([Ca2+]i) by BAPTA‐AM abolished BDNF‐mediated Arc up‐regulation. Surprisingly, BAPTA‐AM did not block ERK activation, indicating that [Ca2+]i and Ras‐Raf‐MAPK are not coupled, and the activation of ERK alone is not sufficient to up‐regulate Arc transcription. Moreover, we found that inhibition of calmodulin (CaM) by W13 blocked both Arc transcription and ERK activation, revealing a Ca2+‐independent function of CaM. These data suggested novel functions of [Ca2+]i and CaM in BDNF signaling. Comparison of the Arc transcription profiles between Ca2+‐stimulated and BDNF‐stimulated neurons demonstrated that the regulatory mechanisms were distinctively tailored to the complex features of neuronal activity. Specifically, PI3K and CaM‐dependent protein kinase (CaMK) activity were required for Ca2+‐stimulated Arc transcription through regulating ERK signaling. Such cross‐talks between PI3K, CaMK, and ERK was absent in BDNF‐stimulated neurons. © 2008 Wiley‐Liss, Inc.
A predictive model of the effects of genotypic, pre‐ and postharvest stages on barley β‐glucan levels
Authors: Tiwari Uma , Cummins Enda
Published: September 2008

BACKGROUND: β‐Glucan is a bioactive component of cereal grains that has many potential uses and health‐promoting benefits. Recent research has focused on improving the nutritional value of food by increasing human exposure to β‐glucan. This study looks at the development of a farm‐level baseline model (including scenario analysis) to evaluate the impact of pre‐ and postharvest stages (including genotypic factors, environmental conditions, agronomic factors and storage) on β‐glucan levels in barley. Monte Carlo simulation techniques were employed to model various stages in pre‐ and postharvest processes and to simulate the factors influencing the level of β‐glucan content in both hulled barley (HB) and hull‐less barley (HLB) genotypes.

RESULTS: The baseline model found that the mean simulated level of β‐glucan was 40.99 and 56.77 g kg−1 for HB and HLB genotypes respectively. A sensitivity analysis highlighted that genotype was the most important parameter in determining the final β‐glucan content (correlation coefficients of 0.66 and 0.78 for HB and HLB respectively), more so than any of the agronomic factors analysed. The scenario analysis highlighted the importance of harvest date (scenario 2) and storage conditions (scenario 3), with a potential 32.6 and 32.7% decrease in β‐glucan (compared with the baseline model) if harvesting is carried out early during physiological maturity (i.e. at growth stage 92) and a potential 20.1 and 19.5% increase in β‐glucan for HB and HLB respectively if storage time is minimised.

CONCLUSION: This study predicted the influence of genotypic, pre‐ and postharvest operations on β‐glucan content and thus allows strategies to be identified to influence β‐glucan content in barley products. Copyright © 2008 Society of Chemical Industry
Influence of equibiaxial extensional strain on stress relaxation of glycerol plasticised wheat gluten
Authors: Zuo Min , Song Yihu , Zheng Qiang
Published: September 2008

BACKGROUND: Glycerol plasticised wheat gluten shows advantages for non‐food applications such as biodegradable package films and bioplastics because of their abundant resources, low cost, good biodegradability and suitable mechanical and oxygen barrier properties. The intention of this study was to evaluate to the equibiaxial stress relaxation of 400 g kg−1 glycerol plasticised gluten at different biaxial strains at room temperature for a better understanding of the processibility.

RESULTS: The plasticised gluten shows significant stress relaxation and the spectra span over six decades of time at biaxial strains from 0.03 to 1.51. Plotting the instantaneous modulus against strain reveals strain softening and strain hardening at strains below and above 0.25, respectively. The relaxation modulus as a function of time can be fitted to the Kohlrausch–Williams–Watts equation.

CONCLUSION: These results suggest that stress relaxation of plasticised gluten is highly dependent on strain level and biaxial deformation accelerates the network relaxation by widening the distribution of relaxation times. Copyright © 2008 Society of Chemical Industry
In vitro degradation and in vivo passage kinetics of carvacrol, thymol, eugenol and trans‐cinnamaldehyde along the gastrointestinal tract of piglets
Authors: Michiels Joris , Missotten Joris , Dierick Noël , Fremaut Dirk , Maene Peter , De Smet Stefaan
Published: September 2008

BACKGROUND: The essential oils (EO) carvacrol, thymol, eugenol and trans‐cinnamaldehyde have well‐documented antimicrobial properties and offer therefore an alternative for the antimicrobial growth promoters in pig feeds. The aim of this work was to determine the degradation and kinetics of these EO along the gastrointestinal tract (GIT) of piglets, which is necessary information for correct application in pig feeds.

RESULTS: None of these compounds was significantly degraded in in vitro simulations of pig gastric fermentation. Carvacrol and thymol were not degraded in jejunal simulations, but significant losses of up to 29% were found in caecal simulations. Eugenol and trans‐cinnamaldehyde showed a more pronounced degradation in jejunal and caecal simulations. A single dose mixed with feed (13.0, 13.2, 12.5 and 12.7 mg kg−1 body weight for carvacrol, thymol, eugenol and trans‐cinnamaldehyde respectively) was given orally to piglets. Half‐lives in total digestive tract ranged between 1.84 and 2.05 h, whereby trans‐cinnamaldehyde showed the fastest disappearance. All of these EO were mainly and almost completely absorbed in the stomach and the proximal small intestine. Plasma concentrations (sum of free and conjugated compound) peaked at 1.39, 1.35 and 0.83 h for carvacrol, thymol and eugenol respectively and this was accompanied by high concentrations in urine.

CONCLUSION: The four compounds were in vitro poorly degraded in the proximal segments of the GIT of piglets, but degradation is expected in more distal segments. In vivo, the EO were mainly and almost completely absorbed in the stomach and the proximal small intestine. Copyright © 2008 Society of Chemical Industry
The effects of sources of supplemental fat on performance, egg quality, and fatty acid composition of egg yolk in laying hens
Authors: Celebi Saban , Macit Muhlis
Published: September 2008

BACKGROUND: The objective of this study was to determine the effects of sources of supplemental fat on laying performance, egg quality, and fatty acid composition of egg yolk.

RESULTS: Two hundreds Isa Brown layers were assigned randomly to be fed ad libitum a standard commercial layer feed (BD), basal diet plus 2% tallow (T), basal diet plus a mixture of 1% tallow and 1% flaxseed oil (MTFO), basal diet plus 2% sunflower oil (SO), or basal diet plus 2% flaxseed oil (FO), which were offered for 8 weeks. Each diet was given to five groups, each containing 10 hens. The feed efficiency and egg production were 2.78 and 53.51% for BD; 2.30 and 63.47% for T; 2.45 and 60.14% for MTFO; 2.29 and 64.30% for SO, and 2.62 and 61.18% for FO groups, respectively. Dietary fat supplementation affected the laying performance but had no significant effects on egg quality parameters. The fatty acid composition of egg yolk lipids were significantly affected by dietary fatty acid composition. The supplemental tallow increased palmitic fatty acid. The proportions of linoleic and arachidonic fatty acids in egg yolks for layers fed the SO diet were higher than in the BD group and those on diets containing other fats. Concentrations of oleic and omega‐3 fatty acids were the highest in layers fed the FO diet during the laying period.

CONCLUSION: The results indicated that dietary animal and plant fats changed the fatty acid composition of egg yolk. Copyright © 2008 Society of Chemical Industry
Development and validation of an RP‐HPLC method for the estimation of adenosine and related purines in brain tissues of rats
Authors: Akula Kiran Kumar , Kaur Manninder , Bishnoi Mahendra , Kulkarni Shrinivas K.
Published: September 2008

A new, rapid and sensitive RP‐HPLC method with UV spectrophotometric detection was developed and validated for the concomitant estimation of adenosine and related purines in rat brain tissue preparations. The HPLC system consisted of C‐18 column with UV–photodiode‐array detection ranging from 210 to 400 nm, facilitating the online confirmation of peak purity. The column temperature was maintained at 30°C and the injection volume was 20 μL. Elution with an isocratic mobile phase consisting of water/methanol/acetonitrile (88:5:7 by volume) at a flow rate of 0.8 mL/min yielded sharp, utmost‐resolved peaks of adenosine (Ade), inosine (Ino), hypoxanthine (Hypoxan) and adenine (Adn) within 10 min. The method was validated with respect to the linearity, accuracy, precision, sensitivity, selectivity and stability. The method was also employed to estimate the naturally occurring purines in discrete regions of rat brain. A new protocol developed for tissue preparation utilizing H2SO4 and Tris buffer gave well‐resolved peaks and high component recoveries (>96%) which eliminated the need of an internal standard. The results show that the method for the determination of Ade, Ino, Hypoxan and Adn by RP‐HPLC described here has good linearity, accuracy, precision, sensitivity, selectivity and is simple and rapid to perform.
Moment independent and variance‐based sensitivity analysis with correlations: An application to the stability of a chemical reactor
Authors: Borgonovo E. , Tarantola S.
Published: September 2008

Recent works have attracted interest toward sensitivity measures that use the entire model output distribution, without dependence on any of its particular moments (e.g., variance). However, the computation of moment‐independent importance measures in the presence of dependencies among model inputs has not been dealt with yet. This work has two purposes. On the one hand, to introduce moment independent techniques in the analysis of chemical reaction models. On the other hand, to allow their computation in the presence of correlations. To do so, a new approach based on Gibbs sampling is presented that allows the joint estimation of variance‐based and moment independent sensitivity measures in the presence of correlations. The application to the stability of a chemical reactor is then discussed, allowing full consideration of historical data that included a correlation coefficient of 0.7 between two of the model parameters. © 2008 Wiley Periodicals, Inc. Int J Chem Kinet 40: 687–698, 2008
Improvement of Differentiation and Mineralization of Pre‐Osteoblasts on Composite Nanofibers of Poly(lactic acid) and Nanosized Bovine Bone Powder
Authors: Ko Eun Kyoung , Jeong Sung In , Lee Ji Hye , Shin Heungsoo
Published: September 2008

The effect of NBM incorporation in PLA nanofibers on their mechanical properties and the differentiation and mineralization of osteoblasts was studied. At 20% NBM, the Young's modulus of the nanofibers was 37.78 ± 4.23, significantly larger than that of pure PLA nanofibers. MC3T3‐E1 pre‐osteoblasts attached to both types of nanofibers and developed full osteogenic phenotypes. A profound effect of NBM on the mineralization of MC3T3‐E1 pre‐osteoblasts was confirmed, suggesting that NBM/PLA composite nanofibers exhibit properties similar to those of the native collagen‐rich mineralized bone matrix, and could therefore serve as a temporary substrate for facilitating the differentiation and mineralization of bone‐forming cells.

magnified image
Evaluating the Ability of Polyhydroxyalkanoate Synthase Mutants to Produce P(3HB‐co‐3HA) from Soybean Oil
Authors: Tsuge Takeharu , Yamamoto Tetsuya , Yano Kotaro , Abe Hideki , Doi Yoshiharu , Taguchi Seiichi
Published: September 2008

Polyhydroxyalkanoate (PHA) synthase from Pseudomonas sp 61‐3 (PhaC1Ps) is able to synthesize P(3HB‐co‐3HA), consisting of a 3HB unit and medium‐chain‐length 3HA units of 6–12 carbon atoms. Expression vectors encoding 76 PhaC1Ps mutants with an amino acid replacement at position 130, 325, 477 or 481 were individually introduced into Ralstonia eutropha. The mutant enzyme genes were evaluated in terms of their abilities to synthesize P(3HB‐co‐3HA) using soybean oil as a carbon source. 20 mutants showed significantly high accumulation levels of PHA exceeding 30 wt.‐% and as high as 57 wt.‐%. It was found that hydrophobic amino acids at the positions are more likely to enhance accumulation of PHA in R. eutropha.

magnified image
Kinetics of corrosion inhibition of benzotriazole to copper in 3.5% NaCl
Authors: Bayoumi F. M. , Abdullah A. M. , Attia B.
Published: September 2008

The kinetics of interaction of benzotriazole (BTAH) with the surface of copper were studied using an electrochemical quartz crystal microbalance (EQMB) and electrochemical impedance spectroscopy (EIS). Upon injecting BTAH into the electrolyte, three regions appear in the time response of the microbalance. Region I (at short time scale of few minutes) exhibits rapid linear growth of mass with time. This is attributed to the formation of a Cu(I)BTA film that is several hundred layers thick. Region II reveals adsorption of BTAH at a slower rate, on the inner Cu(I)BTA complex. Region III is a plateau indicating that the BTAH film attains an equilibrium thickness, which increases with the concentration of BTAH. The polarization resistance of the interface changes with time in a similar fashion while the double layer capacitance decreases. The results suggest that the thickness of the physically adsorbed film of BTAH increases with time and BTAH concentration while the thickness of the inner Cu(I)BTA remains constant. Two semicircles were obtained in the impedance spectra corresponding to the complex Cu(I)BTA and the physically adsorbed BTAH.
Hydrogen permeation measurements in natural sea environment
Authors: Domżalicki P. , Birn J. , Lunarska E.
Published: September 2008

The specially designed, fully equipped, and computerized devices for the underwater long‐term measurements have been used to study the hydrogen permeation rate through the structural steels under natural sea water conditions. By applying constant cathodic potentials, the polarization current and the hydrogen permeation rate were recorded. The temperature and the concentration of S−2 ions in sea water were also measured. After the tests, the concentration of residual hydrogen in samples and the chemistry of the membrane surface were analyzed. The obtained permeation data were compared with the S−2 content in sea water and with the chemistry and appearance of formed deposits. The effect of SRB on the hydrogen permeation through structural steels is dependent on the site of the sample placing and on the sea water temperature. At a lower water temperature, the low hydrogen absorption was measured due to a lower activity of SRB. The highest hydrogen uptake accompanied by the highest content of S in corrosion and cathodic deposits was observed for membranes situated on the sea bed. The electric field of cathodically protected wall did not affect the hydrogen absorption. The hydrogen uptake recorded under the natural sea conditions can be higher than that measured in the laboratory tests, which should be taken into account while servicing marine constructions, especially embedded ones.
Stress corrosion cracking susceptibility of stainless steels in pulp cooking processes—online capillary electrophoresis, potentiostatic and chromatographic studies
Authors: Leinonen H. , Sirén H. , Vastamäki P. , Rovio S. , Peltonen S. , Työppönen T. , Rämö J.
Published: September 2008

An online high temperature capillary electrophoresis instrument (HotUCE), a potentiometer and an ion chromatograph were used in studies on corrosive ions and changes in potential at normal pulping process temperatures in experimental liquors modelling pulp cooking processes at mills. The aim was to evaluate the stress corrosion cracking (SCC) susceptibility of stainless steels. The HotUCE instrument and the potentiometer were online coupled with an autoclave, where welded duplex stainless steel samples were immersed for 500 h in simulated high ionic strength hot black liquor (HBL), hot white liquor (HWL) or green liquor (GL) at 130, 150 or 170 °C, respectively.

The results showed that only minor amounts of oxidized sulphur compounds were formed. The concentrations of corrosive sulphur anions were calculated against sulphur standards. Amounts of sulphur species in the liquor correlated with the changes in the potential of the duplex stainless steel specimens during the cooking experiments. The formation of sulphite during cooking was greater in HWL than in HBL. Changes in the potential showed that reduction processes occurred during the SCC tests. The results indicate that the SCC risk is enhanced at higher temperatures, probably, due to the increased formation of thiosulphate.
Evaluation of 08CH18N10T stainless steel corrosion in subcritical water by electrochemical noise analysis
Authors: Kučera P. , Macák J. , Sajdl P. , Novotný R.
Published: September 2008

The corrosion behaviour of pressurized water reactor (PWR) steam generator tube material (08CH18N10T steel) was studied by electrochemical noise (EN) measurements and electrochemical impedance spectroscopy in high‐temperature water at 280 °C and 8 MPa. Long‐term measurements were performed in two electrolytes: (i) deionised water alkalized to pH25 = 9.5 by KOH; (ii) the same electrolyte with 200 ppm of chlorides added (as KCl). The noise data were processed by two filtering methods and the noise resistance and spectral noise resistance values were calculated. Different contributions to the total impedance were identified and the polarization resistance values were calculated from EIS data. Noise and polarization resistances were compared and the influence of filtering methods was discussed. Instantaneous corrosion data were transformed to integral ones and comparison with mean corrosion current estimated from the oxide thickness was made. It was confirmed that the crucial point of EN analysis is selection of proper cut‐off frequency in high‐pass fast Fourier transform (HP‐FFT).
GD‐OES and electrochemical study of Ce containing conversion layers of hot dip galvanised and by Sendzimir process continuously hot dip galvanised steel plates
Authors: Kőszegi S. , Felhősi I. , Kálmán E.
Published: September 2008

The present work is focused on the conversion layers of hot dip galvanised and continuously hot dip galvanised steel sheets produced by ISD DUNAFERR, Co., Ltd. The conversion coatings on the galvanised steel plates were produced by dipping the plates into solutions of rare earth salts for different immersion periods. The applied rare earth salts were, cerium nitrate and cerium chloride, respectively. The corrosion resistance of the treated plates was tested by DC polarisation measurements and electrochemical impedance spectroscopic method (EIS). The most promising conversion layers were subjected to special corrosion test modelling the effect of the squeezing of plates or coils during storage and delivering and the humidity, simultaneously. The qualitative properties of the corroded surface were tested by glow discharge optical emission spectroscopy (GD‐OES).
Intrinsic Viscosity of Aqueous Solutions of Carboxymethyl Guar in the Presence and in the Absence of Salt
Authors: Badiger Manohar V. , Gupta Nivika R. , Eckelt John , Wolf Bernhard A.
Published: September 2008

Intrinsic viscosities were determined for solutions of CMG in pure water and 0.9 wt.‐% aqueous NaCl. To avoid the 0/0‐type extrapolation typical for Huggins plots, a new procedure was used. For CMG and pure water, this requires only two adjustable parameters: the specific hydrodynamic volume of the polymer in the limit of infinite dilution and a hydrodynamic interaction parameter. The intrinsic viscosity of CMG (no salt) at room temperature is 6 050 mL · g−1; approximately half as large as that of Na‐PSS of comparable molar mass. The ratio of the intrinsic viscosities with and without salt is ≈7 for CMG, as compared to >100 for Na‐PSS. The reasons for the different behaviors of the two types of polyelectrolytes are being discussed.

magnified image
Assembled Structures and Chiroptical Properties of Amphiphilic Block Copolymers Synthesized by RAFT Polymerization of N‐Acryloyl‐L‐alanine
Authors: Mori Hideharu , Matsuyama Motonobu , Endo Takeshi
Published: September 2008

Amino acid‐based amphiphilic block copolymers involving poly(N‐acryloyl‐L‐alanine), poly(A‐Ala‐OH), which exhibits a characteristic chiroptical property and pH‐dependent solubility, have been synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization. The direct polymerization of A‐Ala‐OH without any protecting chemistry using the dithiocarbamate‐terminated polystyrene or poly(N‐acryloyl‐L‐phenylalanine methyl ester) as a macrochain transfer agent produced well‐defined amphiphilic block copolymers. The self‐assembly behaviors and chiroptical properties of these amphiphilic block copolymers in selective solvents were investigated by dynamic light scattering, circular dichroism, and UV–Vis spectroscopic methods.

magnified image
Miscibility of Blends of Biodegradable Polymers and Copolymers with Different Plasticizers
Authors: García‐Lopera Rosa , Monzó Isidro S. , Porcar Iolanda , Abad Concepción , Campos Agustín
Published: September 2008

Miscibility between components of different plasticizer(A)/solvent(B)/biodegradable polymer(C) ternary systems with H‐bonding has been compared. Systems were formed by two H‐donor phenolic plasticizers, 4‐nonylphenol (NP) and 4:4′‐dihydroxydiphenylmethane (BPF); an H‐acceptor solvent, epichlorohydrin (ECH); and H‐acceptor poly(3‐hydroxybutyrate) (PHB) or poly[(3‐hydroxybutyrate)‐co‐(3‐hydroxyvalerate)] (PHBHV) copolymers. Blend miscibility is the result of the balance of three competitive H‐bondings: plasticizer self‐association (AA), plasticizer‐solvent (AB) and plasticizer‐polymer (AC) interassociations. The strength and extent of such specific interactions have been experimentally monitored by fluorescence spectroscopy either in solution or in solid state. Theoretical modelling has been conducted with a recent thermodynamic approach based on two free‐energy excess functions.

magnified image
Cure versus Flow in Dispersed Chip‐Underfill Materials
Authors: Teyssandier Fabien , Sun Yang Y. , Wong Ching P. , Love Brian J.
Published: September 2008

The relative stability of chip‐underfill composite materials was modeled as a function of glass filler concentration between 10 and 70 wt.‐%, filler particle size (between 5 and 25 microns), and the curing temperature of the resin (150 vs. 180 °C), yielding different dynamic viscosity profiles. The stability was gauged using a modified sigmoidal chemorheology model for the dynamic viscosity, and incorporating the time‐dependent viscosity into a model for Stokes' law of sedimentation. We also incorporated a hindered sedimentation term, due to filler concentration due to the higher loadings. Several important findings were observed. First, it appears to be the high concentration of filler that is maintaining the stability of these dispersions during cure. Smaller concentrations of the same particles were predicted to have a larger sedimentation velocity leading to stratification in the resin with time. Second, higher cure temperatures led to a shorter period of sedimentation in a pre‐cured state and resulted in less sedimentation, even though there was probably a slightly smaller viscosity in the pre‐cured condition. While these process models adequately describe the physics of the competitive processes of cure and sedimentation, a full picture may be incomplete without a larger determination of how this also affects polymerization shrinkage and residual shear stress upon cure.

magnified image