bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of antioxidant molecules after peripheral nerve injury and regeneration
Authors: Lanza Cristina , Raimondo Stefania , Vergani Laura , Catena Nunzio , Sénès Filippo , Tos Pierluigi , Geuna Stefano
Published: January 2012

Oxidative stress is considered to be one of the main causes of neural damage after injury. However, little is known about the changes in mRNA expression of antioxidant molecules that occur after injury and regeneration of the peripheral nerve. In the present study, the rat median nerve was transected, and transcriptional changes were studied at day 6 and day 12 after injury in both the proximal and the distal stumps, in the absence or presence of microsurgical repair. The expression profiles of the following genes were investigated: three metallothionein isoforms (MT‐1, MT‐2, and MT‐3), the main antioxidant enzymes (catalase, superoxide dismutase, and glutathione‐S‐transferase), and the marker of cellular damage poly(ADP‐ribose) polymerase‐1 (PARP‐1). The results showed that, in the proximal nerve stump, MT‐3 mRNA expression was significantly and markedly up‐regulated in the absence of surgical repair, whereas MT‐1 and MT‐2 showed significant down‐regulation. In the distal nerve portion, mRNA expression of all MT isoforms decreased significantly in the absence of microsurgical reconstruction, whereas, after repair, MT‐3 mRNA expression alone was up‐regulated. Expression of all the antioxidant enzymes decreased significantly after repair in the proximal nerve portion, but a significant general increase in their mRNA expression was revealed in the distal nerve stump. PARP‐1 expression was significantly up‐regulated in the proximal nerve portion without repair but dramatically reduced after reconstruction. In contrast, PARP‐1 expression increased markedly in the distal stump after surgical repair. Taken together, these findings indicate that antioxidant molecules are differentially modulated and might, therefore, play an important role in peripheral nerve injury and regeneration. © 2012 Wiley Periodicals, Inc.
Minocycline protects oligodendroglial precursor cells against injury caused by oxygen‐glucose deprivation
Authors: Schmitz Thomas , Endesfelder Stefanie , Chew Li‐Jin , Zaak Irina , Bührer Christoph
Published: January 2012

Ischemic brain injury is widely modeled in vitro with paradigms of oxygen‐glucose deprivation (OGD), which leads to cell death. The prevention and attenuation of brain injury by the tetracycline antibiotic minocycline has been attributed largely to suppression of microglial activation, but its benefits in oligodendrocyte cells have not been well characterized. Using primary cultures of rat oligodendroglial precursor cells (OPC) exposed to OGD, we investigated the direct effects of minocycline on the survival, proliferation, and maturation of oligodendroglial lineage cells. OGD for 2 hr caused a decrease in the total number of OPC and the amount of proliferating progenitors by 50%, which was attenuated by inclusion of minocycline. The reduced numbers of immature oligodendroglial cells at 72 hr and of mature oligodendrocytes at 120 hr after OGD were partially restored by minocycline. In OPC, OGD caused an increase of reactive oxygen species (ROS) and production of TUNEL‐positive cell numbers, which was abolished by minocycline. Minocycline preferentially increased the expression of superoxide dismutase under OGD but not in control OPC. Minocycline also prevented the OGD‐induced downregulation of the transcription factors Sox10 and Olig2 and of myelin‐specific genes 2′3′ cyclic nucleotide phosphodiesterase (CNP) and myelin basic protein (MBP) in response to OGD. These studies demonstrate direct protective actions of minocycline on oligodendroglial‐lineage cells, suggesting potential benefit in white matter injury involving OGD. © 2012 Wiley Periodicals, Inc.
Effect of DYRK1A activity inhibition on development of neuronal progenitors isolated from Ts65Dn mice
Authors: Mazur‐Kolecka Bozena , Golabek Adam , Kida Elizabeth , Rabe Ausma , Hwang Yu‐Wen , Adayev Tatyana , Wegiel Jerzy , Flory Michael , Kaczmarski Wojciech , Marchi Elaine , Frackowiak Janusz
Published: January 2012

Overexpression of dual‐specificity tyrosine‐(Y)‐phosphorylation‐regulated kinase 1A (DYRK1A), encoded by a gene located in the Down syndrome (DS) critical region, is considered a major contributor to developmental abnormalities in DS. DYRK1A regulates numerous genes involved in neuronal commitment, differentiation, maturation, and apoptosis. Because alterations of neurogenesis could lead to impaired brain development and mental retardation in individuals with DS, pharmacological normalization of DYRK1A activity has been postulated as DS therapy. We tested the effect of harmine, a specific DYRK1A inhibitor, on the development of neuronal progenitor cells (NPCs) isolated from the periventricular zone of newborn mice with segmental trisomy 16 (Ts65Dn mice), a mouse model for DS that overexpresses Dyrk1A by 1.5‐fold. Trisomy did not affect the ability of NPCs to expand in culture. Twenty‐four hours after stimulation of migration and neuronal differentiation, NPCs showed increased expression of Dyrk1A, particularly in the trisomic cultures. After 7 days, NPCs developed into a heterogeneous population of differentiating neurons and astrocytes that expressed Dyrk1A in the nuclei. In comparison with disomic cells, NPCs with trisomy showed premature neuronal differentiation and enhanced γ‐aminobutyric acid (GABA)‐ergic differentiation, but astrocyte development was unchanged. Harmine prevented premature neuronal maturation of trisomic NPCs but not acceleration of GABA‐ergic development. In control NPCs, harmine treatment caused altered neuronal development of NPCs, similar to that in trisomic NPCs with Dyrk1A overexpression. This study suggests that pharmacological normalization of DYRK1A activity may have a potential role in DS therapy. © 2012 Wiley Periodicals, Inc.
Effect of shading on yield, sugar content, phenolic acids and antioxidant property of coffee beans (Coffea Arabica L. cv. Catimor) harvested from north‐eastern Thailand
Authors: Somporn Chanyarin , Kamtuo Amnouy , Theerakulpisut Piyada , Siriamornpun Sirithon
Published: January 2012

BACKGROUND: Environmental conditions, including shading, generally influence the physical and chemical qualities of coffee beans. The present study assessed the changes in some phenolic compounds, antioxidant activity and agronomic characters of coffee beans (Coffea arabica L. cv. Catimor) as affected by different shading conditions including full sun, three artificial shading conditions using a saran covering (50% shade, 60% shade, and 70% shade) and lychee shade.

RESULTS: Bean weight and bean size increased significantly (P < 0.05) when the shade level was progressively increased. The coffee beans grown under lychee shade exhibited superior bean yield, 1000‐bean weight, total phenolic content and antioxidant activity compared to all other beans. Chlorogenic acid was the most predominant phenolic acid in all samples studied, being the highest in the beans grown under lychee shade, followed by 60% shade, 70% shade, 50% shade and full sun, respectively. In contrast, bean grown under full sun had the highest amount of vanillic acid and caffeic acid.

CONCLUSIONS: Antioxidant activity was highly positively associated with chlorogenic acid content. The content of total sugar (fructose, glucose and sucrose) was found highest in coffee beans grown in 60% shade, with fructose the predominant sugar. Under climatic conditions similar to this experiment, it is advisable that growers provide shade to the coffee crop to reduce heat from direct sunlight and promote yield as well as obtain good quality coffee beans. Copyright © 2012 Society of Chemical Industry
Pot evaluation of synthetic nanosiderite for the prevention of iron chlorosis
Authors: Sánchez‐Alcalá Inmaculada , del Campillo María C , Barrón Vidal , Torrent José
Published: January 2012

BACKGROUND: Iron chlorosis is a problem that affects crops grown on calcareous soils. In this work, we assessed the effectiveness of nanosized siderite (FeCO3) to prevent iron chlorosis, the underlying hypothesis being that the oxidation products of siderite in soil are poorly crystalline, and hence plant‐available, iron oxides.

RESULTS: Nanosized siderite was prepared by mixing FeSO4 and K2CO3 solutions, either pure or doped with phosphate (siderite SID and SIDP, respectively). The average specific surface area was ∼140 m2 g−1 for SID and ∼220 m2 g−1 for SIDP. Experimental oxidation in a calcite suspension yielded goethite for SID and a mixture of lepidocrocite and goethite for SIDP. Two pot experiments in which a SID or SIDP suspension was applied to a calcareous soil at a rate of ∼2 g Fe kg−1 showed nanosiderite to prevent iron chlorosis in chickpea. In a pot experiment with five successive crops, one initial application of ∼0.7 g Fe kg−1 soil in the form of SID or SIDP was as effective as FeEDDHA in preventing Fe chlorosis. The residual effect of nanosiderite when applied to the first crop alone clearly exceeded that of FeEDDHA.

CONCLUSION: Nanosiderite suspensions applied at rates of ∼0.7 g Fe kg−1 soil were highly effective in preventing iron chlorosis and have a great residual effect. Copyright © 2012 Society of Chemical Industry
Pleiotropic increases in free non‐polar lipid, glycolipid and phospholipid contents in waxy bread wheat (Triticum aestivum L.) grain
Authors: Yasui Takeshi
Published: January 2012

BACKGROUND: Diethyl ether‐extractable free lipid (FL), non‐polar or neutral lipid (NL), glycolipid (GL) and phospholipid (PL) contents and water‐saturated 1‐butanol (WSB)‐extractable non‐starch lipid (NSL)—monogalactosyldiglyceride (MGDG), digalactosyldiglyceride (DGDG) and phosphatidylcholine (PC)—contents in bread wheat (Triticum aestivum L.) grain were evaluated to elucidate the possible influence of the Wx‐D1 gene on the lipid composition.

RESULTS: Waxy near‐isogenic lines with a non‐functional Wx‐D1d allele showed consistently increased NL, GL and PL contents among FL and MGDG, DGDG and PC contents among NSL compared with non‐waxy near‐isogenic lines with a functional Wx‐D1a allele throughout three growing/harvest seasons. However, the proportion of NL, GL and PL among FL was not influenced by the non‐waxy/waxy state of the endosperm. The nearly non‐functional Wx‐D1f allele influenced the FL and NL contents in a similar manner to the non‐functional allele across two seasons, while the partly functional Wx‐D1g allele only affected the NL content.

CONCLUSION: The Wx‐D1 locus has pleiotropic effects on the diethyl ether‐extractable FL, NL, GL and PL contents and WSB‐extractable MGDG, DGDG and PC contents of bread wheat grain. The non‐functional Wx‐D1d allele causes an increase in the levels of these lipids. Copyright © 2012 Society of Chemical Industry
Is transureteroureterostomy performed during multi‐organ resection for non‐urothelial malignancy safe and effective?
Authors: Pisters Phillip W. , Pettaway Curtis A. , Liu Ping , Matin Surena F. , Ward John F. , Leibovici Dan
Published: January 2012

Background

Multi‐organ resection in patients with non‐urothelial cancer may include segmental ureteral resection. The resulting ureteral defect can be reconstructed with a transureteroureterostomy (TUU); however, whether TUU is safe and effective in this patient group remains unclear.

Objectives

In the current retrospective analysis, we evaluated renal function before and after complex multi‐organ resection that included TUU to determine whether TUU is safe and effective.

Methods

We retrospectively reviewed the charts of patients who underwent TUU between 1995 and 2011. Renal imaging studies performed before and after TUU were used to determine whether hydronephrosis was present in either kidney. Kidney function was assessed by measuring serum creatinine levels and calculating the estimated glomerular filtration rate (eGFR) before and after TUU.

Results

Twelve patients underwent TUU during multiorgan resection. Median follow‐up time was 15 months. Three patients with cancer recurrence involving the TUU developed progressive hydronephrosis. Serum creatinine levels did not increase more than 0.5 mg/dl in any patient. Kidney function as assessed by eGFR was maintained in all patients (until the time of recurrence in the three patients with recurrence affecting the TUU).

Conclusions

TUU during multi‐organ resection for non‐urothelial malignancy is safe and effective. Long‐term renal function is maintained in the majority of patients. J. Surg. Oncol. 2012; 106:62–65. © 2012 Wiley Periodicals, Inc.
Extensive nodal involvement increases the positivity of blue nodes in the axillary reverse mapping procedure in patients with breast cancer
Authors: Rubio Isabel T. , Cebrecos Isaac , Peg Vicente , Esgueva Antonio , Mendoza Cesar , Cortadellas Tomas , Cordoba Octavi , Espinosa‐Bravo Martin , Xercavins Jordi
Published: January 2012

Background

The axillary reverse mapping (ARM) technique has been proposed to prevent arm lymphedema. We conducted this study to assess the feasibility of the technique and the outcomes of patients with neoadjuvant chemotherapy (NAC).

Methods

From July 2009 to May 2010, a prospective study was performed in 36 patients with breast cancer undergoing an ALND. The ARM technique was performed injecting 3 cm3 of Patent Blue in the ipsilateral arm. Of the 36 patients, 29 patients received NAC previously to the ARM and 7 patients had an ALND and ARM performed as first treatment for positive axillary nodes.

Results

The identification rate of blue nodes was 83.3% (30 patients). Sentinel lymph node (SLN) was performed in 15 of 29 (42%) patients in the NAC group. Of these 15, two patients (13%) had a concordance between the blue and the hot node. Blue nodes were positive in 4 (13%) of the 30 patients.

Conclusions

The ARM technique is feasible in patients undergoing NAC. Patients with extensive nodal involvement have increased risk of having positive blue nodes. More studies are needed to assess the subgroup of patients with positive axilla that may have the blue node spared without compromising the oncological treatment. J. Surg. Oncol. 2012; 106:89–93. © 2012 Wiley Periodicals, Inc.
An Examination of the Determinants of In‐Flight Duty‐Free Shopping: Hedonic and Utilitarian Motivations
Authors: Doong Her‐Sen , Wang Hui‐Chih , Law Rob
Published: January 2012

This research note presents the findings of a study that empirically examined air passengers' in‐flight duty‐free shopping behaviors in the perspectives of utilitarian and hedonic motivations. On the basis of the primary data collected from 212 air passengers in Taiwan, empirical findings revealed that both utilitarian and hedonic motivations affect air passengers' intentions to browse in‐flight duty‐free shopping catalogues. Findings also showed that hedonic motivation does not directly influence air passengers' in‐flight purchase intentions. Instead, a higher utilitarian motivation can directly enhance passengers' in‐flight purchase intentions. Copyright © 2012 John Wiley & Sons, Ltd.
Temporal changes in age and sex ratios of forest grouse harvested in northeastern oregon
Authors: Hansen Michael C. , Hagen Christian A. , Loughin Thomas M. , Budeau David A. , Coggins Victor L. , Reishus Brandon S.
Published: January 2012

Ratio of immature (young of the year) grouse to adult birds (I:A) in the harvest of upland game birds is commonly used as an index to annual reproduction; however, I:A ratios can vary as the season progresses producing biased estimates. We analyzed I:A ratios in the daily harvest of dusky grouse (Dendragopus obscurus) and ruffed grouse (Bonasa umbellus) in northeastern Oregon over 28 years (1981–2008) and found that I:A ratios in the harvest declined for both species as the hunting season progressed. We also analyzed ratios of adult female to adult male (AF:AM) grouse to determine if female and male grouse were harvested in equal numbers throughout the harvest season. We found that more males than females of both species were harvested, but that AF:AM ratio of both dusky and ruffed grouse did not change during most of the hunting season. Approximately 50% of the annual harvest occurred during the first 14 days of the hunting season. Therefore, we recommend using the ratios of I:A birds in the first 14 days of the harvest season as the best index to annual reproduction of forest grouse in northeast Oregon. © 2011 The Wildlife Society.
The Cox ring of the space of complete rank two collineations
Authors: Hausen Jürgen , Liebendörfer Michael
Published: January 2012

We consider the space of complete rank two collineations. Starting from its description as a limit of GIT‐quotients of a Grassmanian G(2, n) by a certain \documentclass{article}\usepackage{amssymb}\begin{document}\pagestyle{empty}$\mathbb {C}^*$\end{document}‐action, we determine the Cox ring by means of toric ambient modifications.
Cobaltocenium‐Containing Block Copolymers: Ring‐Opening Metathesis Polymerization, Self‐Assembly and Precursors for Template Synthesis of Inorganic Nanoparticles
Authors: Ren Lixia , Zhang Jiuyang , Hardy Christopher G. , Ma Shuguo , Tang Chuanbing
Published: January 2012

Side‐chain cobaltocenium‐containing block copolymers are prepared by ring‐opening metathesis polymerization (ROMP). These block copolymers include one cobaltocenium‐containing block, with the second block being either a nonmetal‐containing segment or a cobaltocenium‐containing segment with different counterions. These block copolymers are self‐assembled into spherical core/shell micelles in solutions. A template strategy is used to prepare cobalt (II or III)‐containing nanoparticles by treating the self‐assembled micelles via UV/ozonolysis and pyrolysis. Characterization by X‐ray photon spectroscopy and X‐ray diffraction indicates that these nanoparticles consist of different oxidants of cobalt, depending on the chemical compositions of block copolymers.
Ring geometry as an important part of distortion potential
Authors: Frerichs F. , Lübben T. , Hoffmann F. , Zoch H.‐W.
Published: January 2012

Causes for distortion phenomena during heat treatment are inhomogeneous or asymmetric distributions of mass, alloying elements, microstructure, and residual stresses. These causes generate a distortion potential of the work piece which could be set free during the final heat treatment. But for a concrete calculation of the distortion potential it is necessary to know the interrelationships between the changes in dimensions and shape and the strains within the work piece. If these functional interrelationships are known it is possible to estimate the strains which are necessary for observed distortion effects. For elementary geometries like shafts, plates, and rings the distortion potential generates characteristic distortions. For simple shafts e. g. mostly “banana forms” can be observed, whereas for cylindrical rings often an oval shape governs the out of roundness. This practical experience for cylindrical rings will be analyzed in a more detailed way. The knowledge of the interrelation of geometry and strains in combination with energy considerations enables a quantitative expression of the distortion potential of cylindrical rings.
Relationship between strain distributions and shape deviations of rings caused in clamping
Authors: Sölter J.
Published: January 2012

In 2010 Frerichs et al. proposed a comparatively simple equation describing the relationship between shape deviations and the internal strain state of a ring. It can also be applied to predict shape deviations of rings on the basis of one analyzed clamping case. In this paper the validity of the equation is shown for elastic and elastic‐plastic deformations of rings fixed in k clamping jaws (k = 2, 3, 4, 6) in analytical and 3D Finite Element Analyses, respectively. The theoretical results are in very good agreement with Frerichs' formula for both cases. However, in the elastic case constant strain energy for different numbers of clamping jaws seems to be the necessary and sufficient prerequisite to use Frerichs' approach for predicting amplitudes of order k based on the knowledge of a certain amplitude an≠k. For a given ring geometry this is fulfilled in the elastic case, if clamping forces are proportional to k2–1.
Cross‐plane quality control concept of the bearing ring production
Authors: Zhang P. , Renken V. , Goch G.
Published: January 2012

This contribution reports on a cross‐plane quality control concept for the production of bearing rings. The principal part of this quality control concept is the cross‐plane controller, which actually acts as an iterative optimization throughout the production chain and bases upon the models of each sub‐process. The cross‐plane controller and a model‐based sub‐control system for the gas quenching process are introduced in this paper.
Compensation of part distortion in soft‐turning of bearing rings
Authors: Beekhuis B. , Stöbener D. , Brinksmeier E. , Goch G.
Published: January 2012

During soft‐turning of rings, both, deviation of the wall thickness and the shape occur. Additionally, further changes of shape result from the subsequent heat treatment. To ensure desired geometric tolerances, a high stock allowance for finishing is necessary. Geometric deviations of machined rings originate mainly from workpiece clamping during the machining process due to elastic deformation. Therefore, several special clamping devices are applied in industry to reduce workpiece deformation. But the choice of chucks is always a trade‐off between high flexibility and low part distortion. To ensure minimal part distortion in spite of using flexible clamping devices, clamping strategies and novel dynamical turning processes have been developed. Dynamical adapting of the depth of cut based on the measurement of geometric errors, is realized by using a tool actuator combined with an in‐process ultrasonic measurement system. This paper discusses the compensation potential of developed methods to reduce part distortion.
Compensation of roundness deviations of bearing rings by heat treatment
Authors: Lütjens J. , Surm H. , Hunkel M. , Gafsi H. , Renken V. , Schüttenberg S.
Published: January 2012

The compensation of distortion of 100Cr6 (SAE 52100) bearing rings can be achieved within each of the production chain steps turning, austenitisation, and quenching. This work evaluates the compensation potential during heat treatment. For this purpose, rings are austenitised in a bottom‐loading furnace with six individually controlled heating elements. Temperature distributions in the rings during heating and soaking are used to influence the local solute carbon content. After austenitisation, the rings are quenched in a gas nozzle field with 13 individually controlled quenching zones, one on the inner surface and 12 on the outer surface of the ring. The roundness deviation just before quenching is measured using tactile sensors. The heat treated parts are examined with regard to distortion but also to the requirements of hardness, microstructure, and residual stresses. Limits of roundness deviation compensation in different Fourier orders are evaluated.
Experimental investigation concerning the development of distortion potential during the production of 20MnCr5
Authors: Prinz C. , Rentsch R.
Published: January 2012

Investigations within the SFB 570 “Distortion Engineering” showed that properties of the low alloyed 20MnCr5 (SAE 5120) had an influence on distortion. The changes of curvature of blind‐hardened shafts could be correlated to a macroscopic structure, which was visible at micrographs of cross‐sections. The development of lined structures and the macroscopic structure was observed by metallographic methods at cast material, hot‐rolled material and an intermediate step of the hot forming process. The lined structure within the semi‐finished material was measured by EPMA measurements with highest resolution. The contents of the alloying elements Mn and Cr could be correlated to the development of the lined structure, the carbon content fluctuated in a higher frequency. To determine the differences of phase transformations, two different homogenous materials were produced by spray‐forming: one with the maximum content of the alloying element Mn, Cr and C concerning the EPMA measured values, and a second with the minimum measured Mn, Cr and C content. The material was hot formed to a diameter of 25 mm after spray‐forming and characterised by dilatometer measurements.
Finite element analysis of the hot rolling process on the origins of inhomogeneities related to steel bar distortion
Authors: Rentsch R. , Prinz C.
Published: January 2012

Recent analyses of the distortion of shafts made of the steel 20MnCr5 showed a bending along their length axis. Metallographic analyses revealed remarkable concentration fluctuations of Manganese and Chromium in the shaft center, which could be attributed to macro‐segregations. Its characteristic rectangular shape correlated with the direction of shaft bending. In order to understand the origin of the rectangular segregation in shafts manufactured from hot‐rolled round bars and to determine the influence of the forming process on the found distribution, a Finite element (FE) analysis of the whole hot‐rolling process was carried out. The results show a significantly inhomogeneous strain distribution at the shaft cross‐section, which provides a distortion potential for a preferred shaft bending direction. Further it was found, that the forming process influences the shape of the macro‐segregation in the shaft center, but the analysis hints in this case on an origin of the rectangular macro‐segregation in continuous casting.
Influence of manufacturing parameters on gear distortion
Authors: Kohlhoff T. , Prinz C. , Rentsch R. , Surm H.
Published: January 2012

Realising the system‐oriented approach of “Distortion Engineering”, the influence of multiple parameters on the distortion of cylindrical gears was investigated by design of experiments. Aim of this research work was to investigate the effect of production parameters before the final heat treatment. The established experimental design focuses on the analysis of two main parts of gear distortion. One part is the distortion of the teeth themselves; the other part is a displacement of the teeth due to the distortion of the disk‐shaped base body. The selection of the varied parameters is partly based on results of a system‐oriented experiment with disks. Therefore several influences on the base body distortion are known. In comparison to the analysis of disk distortion the interpretation of gear distortion measurements requires significantly extended effort. Besides a determination of the distortion of the complex involute tooth profile, it has to be distinguished between a change of the tooth profile and a change of the base body.
Methodical investigation of distortion biasing parameters during case hardening of spur wheels
Authors: Steinbacher M. , Surm H. , Clausen B. , Lübben Th. , Hoffmann F.
Published: January 2012

Highly stressed gears are typically heat treated to satisfy operational demands. Case hardening is a common heat treatment associated with power train components. In the heat treatment process complex distortion processes take place, which were studied in these examinations. Object of the actual investigations were spur wheels with module 2.557 and 42 teeth on the wheel with a helix angel of 23°. The case hardening was realized utilizing low pressure carburisation with subsequent high pressure gas quenching in a heat treatment furnace of industrial proportion. The systematic analysis was guided using design of experiment methods. In strategic focus were the three contributing heat treatment steps of heating, carburisation and quenching. Heating related factors were the batch design, the heat transfer and the preheating temperature. During carburisation the temperature, carburisation depth and surface carbon content as well as the atmosphere during diffusion were altered. Finally the quenching related variation was the hardening temperature. The identified main factors on size as well as shape changes of the base body and the toothing will be presented and discussed.
Adapted spray quenching for distortion control
Authors: Schüttenberg S. , Lütjens J. , Hunkel M. , Fritsching U.
Published: January 2012

For the analysis of workpiece distortion activated during heat treatment processes, the hardening by quenching in flexible flow fields is modelwise described. Here, process conditions and the resulting heat transfer from workpiece surfaces to the quenching medium are crucial conditions for the description of the quenching process and a possibly appearing distortion. During the quenching process suitable distortion compensation can be realised by impressing controlled asymmetric heat transfer conditions on workpiece surfaces by the use of liquid jet or spray arrangements. Here, the controlled quenching in and with liquid media and especially the use of two phase atomisers for spray cooling processes enables the generation of specific local heat transfer conditions with required high intensities.
Strategies for reduced distortion during laser beam welding of shaft‐hub joints
Authors: Buschenhenke F. , Seefeld T. , Vollertsen F.
Published: January 2012

The joining of shaft‐hub connections is gaining in importance in the area of power train applications. The quality demands in abrasion and power transmission are playing a major role. Dimensional as well as repeat accuracies are essential quality criteria, which have to be focused on. The understanding of the whole process chain in view of different distortion potentials introduced in each processing step provides the ability to control the distortion of the welded components. The laser beam sources of the new generation permit a high power welding process and high beam quality at the same time. These laser beams are capable of producing deep and narrow weld seams. This work deals with compensation strategies of deformations during laser beam welding in axial welded shaft‐hub joints made of steel. Furthermore, simultaneous welding with two laser beams and the influence of the process chain were investigated to characterise the influence of these strategies tactile differential measurements were done. The results were discussed regarding numerical calculations in the FEM application SYSWELD.
Areal parameters for the characterisation of gear distortions
Authors: Stöbener D. , von Freyberg A. , Fuhrmann M. , Goch G.
Published: January 2012

Gear distortion is influenced by several effects which might originate in various steps of the entire production chain. To understand the distortion mechanisms including interactions between different influencing parameters, a system approach for the whole production process is required. As distortion is not constrained to the toothing but also effects the gear's base body, an extended measuring strategy (compared to the standard) has been devised. Based on this strategy, an areal evaluation has been developed and new quality parameters describing the deviations of the whole gear and of each tooth have been defined. In contrast to the standard evaluation, the new quality parameters consider the relationship between different measured lines. This offers the possibility to determine the influences of the base body deviations on the toothing distortion and to separate them from the intrinsic toothing deviation. This paper describes the developed strategies and methods and compares them with the standard inspection process.
Monitoring a laser beam heat treatment process by means of digital speckle photography
Authors: Kamau E. N. , Sakkiettibutra J. , Falldorf C. , Mundt J. , Kopylow C. v.
Published: January 2012

In the current study displacements of a single angled tooth (helical gear, steel EN 20MnCr5) were measured with sub‐pixel accuracy by means of Digital Speckle Photography (DSP). The main aim was to assess the in‐process performance of DSP while measuring three dimensional deformations in a laser based heat treatment process. This task dictated the integration of DSP as a non‐invasive experimental method, which is insensitive to different interfering effects, e. g. vibrations and varying coefficients of refraction, into the heat treatment setup. The results attained were compared with data from laser triangulation measurements and FEM‐based temperature simulations and were found to show good agreement within the limitations of these methods. Knowledge of deformations of the component during the laser beam based heat treatment process allows an analysis of the effects of residual stress fields generated with a high power laser. This analysis aims at minimisation of unwanted distortions resulting from hardening heat treatment.
Approaches to describe distortion along process chains
Authors: Thoben K.‐D. , Klein D. , Seifert M. , Wuest T.
Published: January 2012

During the decade of the Collaborative Research Center CRC 570 “Distortion Engineering” many methods were developed and extended. Within this paper these methods are evaluated in respect of practical application in process planning. The methods can be arranged by two different targets. On the one hand by mainly consider distortion up to predict distortion to support planning. The similarity of all methods is given due to the fact that distortion has to be seen as a system attribute. After the introduction of the methods and their basic functionality they were evaluated against process planning in particular the planning types “repeat planning” up to “new planning”. Generally it can be shown that the transferability on other geometries, processes and materials is strongly limited. Furthermore the methods which only consider distortion seem better to fulfill the tasks of the planning types as methods which determine distortion. The best method was the method which compares different process chains. Nevertheless, this more theoretical evaluation has to be verified by industrial process planning.
Knowledge and planning system for distortion engineering
Authors: Thoben K.‐D. , Klein D. , Wuest T. , Zoch H.‐W.
Published: January 2012

Presented will be a process‐oriented knowledge and planning system for a structured depositing and locating of findings along manufacturing processes for component distortion. In the focus of this article are the reasons for the chosen structure and the presentation of the model for implementation of this system. It is shown that the findings must be seen first in connection with a process chain. A further evaluation of the findings will show that information can then be generalised to sub‐process chains. The findings can be accessed from a knowledge perspective to be a basis of new experiments, but also be used for archiving of knowledge. The planning view for example is suitable to help a planner to set up a process plan. The system is designed in a way that it can be easily extended by new findings. Concluding, the functioning of the system will be illustrated by two practical examples.
Phosphorus intercalation of halloysite nanotubes for enhanced fire properties of polyamide 6
Authors: Marney D. C. O. , Yang W. , Russell L. J. , Shen S. Z. , Nguyen T. , Yuan Q. , Varley R. , Li S.
Published: January 2012

The fire performance of polyamide 6 (PA6) blended with phenyl phosphonic acid functionalized halloysite nanotubes (PPA‐HNTs) is evaluated in order to determine if there is any fire performance gains over the unmodified composite. In the continuing search for safe halogen‐free fire retardants for polymers, and the desire to more fully capture the advantages of nano‐materials, this research seeks to utilize any synergy which might result in improved fire performance of PA6, via the known advantages offered by nano particles and phosphorus‐based compounds. HNTs offer the ability for functionalization by exchange at their hydroxyl sites, while PPA can readily attach at these sites because of its acidity. In this context, the nanotubes act as a carrier for the acid within the polyamide polymeric matrix because it is readily intercalated and functionalized with the acid. The intercalated nano particles are added to the polyamide via melt extrusion and then analyzed using thermal analysis and cone calorimetry. The key finding from this work is that functionalization of HNTs with PPA, followed by blending into PA6 results in a significant improvement in fire performance by altering the combustion dynamics of the polymer. This work proposes a new synergistic fire retardant system for polyamides utilising relatively safe and inexpensive components. More broadly, the concept of using a carrier such as HNTs, which is so easily functionalized, can be applied to other thermoplastic materials, and other additives, for improvements in material properties other than fire. Copyright © 2012 John Wiley & Sons, Ltd.
‘Women Are Bad at Math, but I'M Not, Am I?’ Fragile Mathematical Self–Concept Predicts Vulnerability to A Stereotype Threat Effect on Mathematical Performance
Authors: Gerstenberg Friederike X. R. , Imhoff Roland , Schmitt Manfred
Published: January 2012

The present research reports the results of three studies showing that individuals with a fragile self–concept in the domain of performance are particularly vulnerable to stereotype threat effects. Specifically, women who explicitly described themselves as rather mathematical but whose implicit self–concepts contradicted these claims were vulnerable to stereotype threat effects on mathematical performance. This effect was robust across three studies, independent of the subtleness or content of the stereotype threat manipulation. Additionally, it was shown that the effect was mediated by anxious worrying (Study 3). Copyright © 2012 John Wiley & Sons, Ltd.
Assessment of the high‐dose concept and level of control provided by MON 87701 × MON 89788 soybean against Anticarsia gemmatalis and Pseudoplusia includens (Lepidoptera: Noctuidae) in Brazil
Authors: Bernardi Oderlei , Malvestiti Glaucia S , Dourado Patrick M , Oliveira Wladecir S , Martinelli Samuel , Berger Geraldo U , Head Graham P , Omoto Celso
Published: January 2012

BACKGROUND: Genetically modified MON 87701 × MON 89788 soybean (Glycine max), which expresses the Cry1Ac and EPSP‐synthase proteins, has been registered for commercial use in Brazil. To develop an Insect Resistance Management (IRM) program for this event, laboratory and field studies were conducted to assess the high‐dose concept and level of control it provides against Anticarsia gemmatalis and Pseudoplusia includens.

RESULTS: The purified Cry1Ac protein was more active against A. gemmatalis [LC50 (FL 95%) = 0.23 (0.15–0.34) µg Cry1Ac mL−1 diet] than P. includens [LC50 (FL 95%) = 3.72 (2.65–4.86) µg Cry1Ac mL−1 diet]. In bioassays with freeze‐dried MON 87701 × MON 89788 soybean tissue diluted 25 times in an artificial diet, there was 100% mortality of A. gemmatalis and up to 95.79% mortality for P. includens. In leaf‐disc bioassays and under conditions of high artificial infestation in the greenhouse and natural infestation in the field, MON 87701 × MON 89788 soybean showed a high level of efficacy against both target pests.

CONCLUSIONS: The MON 87701 × MON 89788 soybean provides a high level of control against A. gemmatalis and P. includes, but a high‐dose event only to A. gemmatalis. Copyright © 2012 Society of Chemical Industry
Ginsenoside Rg3 Inhibits Endothelial Progenitor Cell Differentiation through Attenuation of VEGF‐Dependent Akt/eNOS Signaling
Authors: Kim Jae‐Won , Jung Seok‐Yun , Kwon Yi‐Hong , Lee Sang‐Hun , Lee Jun‐Hee , Lee Boo‐Yong , Kwon Sang‐Mo
Published: January 2012

Endothelial progenitor cells (EPCs) play a critical role both in vascular repair after cell transplantation for ischemic diseases and in the growth of early tumors by intervening with the angiogenic switch during tumor progression. This paper reports on the effect of ginsenoside Rg3 in EPCs as a candidate angiogenesis inhibitor for in vitro functional assays. CD34+ cells were isolated from human cord blood and the study investigated whether or not ginsenoside Rg3 regulated EPC bioactivities including cell proliferation, differentiation, migration and tube formation. Although ginsenoside Rg3 did not affect the ex vivo expansion of CD34 and/or KDR (VEGFR2) stem/progenitor cells, treatment with ginsenoside Rg3 led to a significant decrease in CD34‐expressing cells, specifically the absolute number of expanded CD34+ cells. Importantly, a significantly decreased number of EPC colony‐forming units among human cord blood‐derived CD34+ cells was observed, implying that ginsenoside Rg3 inhibited EPC differentiation, in particular, the commitment to primitive EPC colonies (the early stage of EPC differentiation). Moreover, treatment of CD34‐derived EPCs with ginsenoside Rg3 resulted in the attenuation of VEGF‐dependent Akt/eNOS signaling as well as the inhibition of migration and tube formation. In conclusion, this study provides in vitro evidence for ginsenoside Rg3 as a potential therapeutic molecule, specifically as an angiogenesis inhibitor that functions by attenuating EPC bioactivities. Copyright © 2012 John Wiley & Sons, Ltd.
A new implementation of the adaptive mesh transform in the Met Office 3D‐Var System
Authors: Piccolo Chiara , Cullen Mike
Published: January 2012

This paper looks at the application of two new features of the adaptive mesh transform in the Met Office variational data assimilation which modifies the background error correlations to better represent the boundary layer structure. The new features are an improved normalization procedure and the recalculation of the adaptive mesh within the nonlinear analysis procedure. Relative to the initial implementation the results show improvements in the forecast skill of the UK4 model for both summer and winter and a reduction of the analysis root mean square errors with respect to radiosonde, aircraft, SEVIRI and ground GPS observations for both periods. Forecast errors at T + 2, 3, 4 h are also reduced with respect to aircraft, surface, SEVIRI, ground GPS observations and with respect to radiosonde in the boundary layer for relative humidity and for potential temperature around temperature inversions. These improvements are attributed to the variation of the background vertical correlations and the implied background error variances in the assimilation due to the greater movement of the mesh away from the lower boundary, in particular in areas where temperature inversions or stratocumulus layers are present. Copyright © 2012 British Crown copyright, the Met Office. Published by JohnWiley & Sons Ltd.
Relaxing the Tropics to an ‘observed’ state: analysis using a simple baroclinic model
Authors: Hoskins Brian , Fonseca Ricardo , Blackburn Mike , Jung Thomas
Published: January 2012

The technique of relaxation of the tropical atmosphere towards an analysis in a month‐season forecast model has previously been successfully exploited in a number of contexts. Here it is shown that when tropical relaxation is used to investigate the possible origin of the observed anomalies in June–July 2007, a simple dynamical model is able to reproduce the observed component of the pattern of anomalies given by an ensemble of ECMWF forecast runs. Following this result, the simple model is used for a range of experiments on time‐scales of relaxation, variables and regions relaxed based on a control model run with equatorial heating in a zonal flow.

A theory based on scale analysis for the large‐scale tropics is used to interpret the results. Typical relationships between scales are determined from the basic equations, and for a specified diabatic heating a chain of deductions for determining the dependent variables is derived. Different critical time‐scales are found for tropical relaxation of different dependent variables to be effective. Vorticity has the longest critical time‐scale, typically 1.2 days. For temperature and divergence, the time‐scales are 10 hours and 3 hours, respectively. However not all the tropical fields, in particular the vertical motion, are reproduced correctly by the model unless divergence is heavily damped. To obtain the correct extra‐tropical fields, it is crucial to have the correct rotational flow in the subtropics to initiate the Rossby wave propagation from there. It is sufficient to relax vorticity or temperature on a time‐scale comparable or less than their critical time‐scales to obtain this. However if the divergent advection of vorticity is important in the Rossby Wave Source then strong relaxation of divergence is required to accurately represent the tropical forcing of Rossby waves. Copyright © 2012 Royal Meteorological Society
Laboratory experiments in the system dynamics field
Authors: Arango Aramburo Santiago , Castañeda Acevedo Jaime Andrés , Olaya Morales Yris
Published: January 2012

Controlled experiments, long used in psychology and economics, are increasingly being used to develop theories in the areas of interest to management science, including decision making and systems. In this paper we review laboratory experiments relating to system dynamics. We discuss how these experiments help to (1) determine causes for subjects' poor performance in dynamic environments and (2) model such behaviour in system dynamics models. Finally, we present the main insights from the works reviewed and propose some ideas for a research agenda. Copyright © 2012 System Dynamics Society
Evaluation of reagent effect on skin using time‐of‐flight secondary ion mass spectrometry and multivariate curve resolution
Authors: Aoyagi Satoka , Matsuzaki Takashi , Takahashi Masumi , Sakurai Yuuki , Kudo Masahiro
Published: January 2012

Chemical imaging and depth profiling of skin is useful for studying various biological phenomena. Although secondary ion images of biomolecules such as phosphocholine and cholesterol distributions on skin samples are easily obtained with time‐of‐flight secondary ion mass spectrometry (TOF‐SIMS), the observation of proteins or minor ingredients is often difficult. In this study, TOF‐SIMS imaging data of skin samples were analyzed with multivariate curve resolution (MCR) to obtain information on reagents applied to the middorsal skin of mice. The skin was sliced with a cryostat and placed on indium‐tin oxide glass plates. The samples were measured with TOF‐SIMS using Bi3++, and then the obtained data were analyzed with MCR. As a result, distributions of secondary ions related to the reagents were suggested by MCR results, although they were not obtained by a manual analysis using respective peaks. Copyright © 2012 John Wiley & Sons, Ltd.